fs/ext4/super.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/ext4/super.c
   4  *
   5  * Copyright (C) 1992, 1993, 1994, 1995
   6  * Remy Card (card@masi.ibp.fr)
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  *
  10  *  from
  11  *
  12  *  linux/fs/minix/inode.c
  13  *
  14  *  Copyright (C) 1991, 1992  Linus Torvalds
  15  *
  16  *  Big-endian to little-endian byte-swapping/bitmaps by
  17  *        David S. Miller (davem@caip.rutgers.edu), 1995
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/string.h>
  22 #include <linux/fs.h>
  23 #include <linux/time.h>
  24 #include <linux/vmalloc.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/backing-dev.h>
  29 #include <linux/parser.h>
  30 #include <linux/buffer_head.h>
  31 #include <linux/exportfs.h>
  32 #include <linux/vfs.h>
  33 #include <linux/random.h>
  34 #include <linux/mount.h>
  35 #include <linux/namei.h>
  36 #include <linux/quotaops.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/dax.h>
  42 #include <linux/cleancache.h>
  43 #include <linux/uaccess.h>
  44 #include <linux/iversion.h>
  45
  46 #include <linux/kthread.h>
  47 #include <linux/freezer.h>
  48
  49 #include "ext4.h"
  50 #include "ext4_extents.h"       /* Needed for trace points definition */
  51 #include "ext4_jbd2.h"
  52 #include "xattr.h"
  53 #include "acl.h"
  54 #include "mballoc.h"
  55 #include "fsmap.h"
  56
  57 #define CREATE_TRACE_POINTS
  58 #include <trace/events/ext4.h>
  59
  60 static struct ext4_lazy_init *ext4_li_info;
  61 static struct mutex ext4_li_mtx;
  62 static struct ratelimit_state ext4_mount_msg_ratelimit;
  63
  64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  65                              unsigned long journal_devnum);
  66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  67 static int ext4_commit_super(struct super_block *sb, int sync);
  68 static void ext4_mark_recovery_complete(struct super_block *sb,
  69                                         struct ext4_super_block *es);
  70 static void ext4_clear_journal_err(struct super_block *sb,
  71                                    struct ext4_super_block *es);
  72 static int ext4_sync_fs(struct super_block *sb, int wait);
  73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75 static int ext4_unfreeze(struct super_block *sb);
  76 static int ext4_freeze(struct super_block *sb);
  77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78                        const char *dev_name, void *data);
  79 static inline int ext2_feature_set_ok(struct super_block *sb);
  80 static inline int ext3_feature_set_ok(struct super_block *sb);
  81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82 static void ext4_destroy_lazyinit_thread(void);
  83 static void ext4_unregister_li_request(struct super_block *sb);
  84 static void ext4_clear_request_list(void);
  85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
  86                                             unsigned int journal_inum);
  87
  88 /*
  89  * Lock ordering
  90  *
  91  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  92  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  93  *
  94  * page fault path:
  95  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  96  *   page lock -> i_data_sem (rw)
  97  *
  98  * buffered write path:
  99  * sb_start_write -> i_mutex -> mmap_sem
 100  * sb_start_write -> i_mutex -> transaction start -> page lock ->
 101  *   i_data_sem (rw)
 102  *
 103  * truncate:
 104  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
 105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
 106  *   i_data_sem (rw)
 107  *
 108  * direct IO:
 109  * sb_start_write -> i_mutex -> mmap_sem
 110  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
 111  *
 112  * writepages:
 113  * transaction start -> page lock(s) -> i_data_sem (rw)
 114  */
 115
 116 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 117 static struct file_system_type ext2_fs_type = {
 118         .owner          = THIS_MODULE,
 119         .name           = "ext2",
 120         .mount          = ext4_mount,
 121         .kill_sb        = kill_block_super,
 122         .fs_flags       = FS_REQUIRES_DEV,
 123 };
 124 MODULE_ALIAS_FS("ext2");
 125 MODULE_ALIAS("ext2");
 126 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 127 #else
 128 #define IS_EXT2_SB(sb) (0)
 129 #endif
 130
 131
 132 static struct file_system_type ext3_fs_type = {
 133         .owner          = THIS_MODULE,
 134         .name           = "ext3",
 135         .mount          = ext4_mount,
 136         .kill_sb        = kill_block_super,
 137         .fs_flags       = FS_REQUIRES_DEV,
 138 };
 139 MODULE_ALIAS_FS("ext3");
 140 MODULE_ALIAS("ext3");
 141 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 142
 143 static int ext4_verify_csum_type(struct super_block *sb,
 144                                  struct ext4_super_block *es)
 145 {
 146         if (!ext4_has_feature_metadata_csum(sb))
 147                 return 1;
 148
 149         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 150 }
 151
 152 static __le32 ext4_superblock_csum(struct super_block *sb,
 153                                    struct ext4_super_block *es)
 154 {
 155         struct ext4_sb_info *sbi = EXT4_SB(sb);
 156         int offset = offsetof(struct ext4_super_block, s_checksum);
 157         __u32 csum;
 158
 159         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 160
 161         return cpu_to_le32(csum);
 162 }
 163
 164 static int ext4_superblock_csum_verify(struct super_block *sb,
 165                                        struct ext4_super_block *es)
 166 {
 167         if (!ext4_has_metadata_csum(sb))
 168                 return 1;
 169
 170         return es->s_checksum == ext4_superblock_csum(sb, es);
 171 }
 172
 173 void ext4_superblock_csum_set(struct super_block *sb)
 174 {
 175         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 176
 177         if (!ext4_has_metadata_csum(sb))
 178                 return;
 179
 180         es->s_checksum = ext4_superblock_csum(sb, es);
 181 }
 182
 183 void *ext4_kvmalloc(size_t size, gfp_t flags)
 184 {
 185         void *ret;
 186
 187         ret = kmalloc(size, flags | __GFP_NOWARN);
 188         if (!ret)
 189                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 190         return ret;
 191 }
 192
 193 void *ext4_kvzalloc(size_t size, gfp_t flags)
 194 {
 195         void *ret;
 196
 197         ret = kzalloc(size, flags | __GFP_NOWARN);
 198         if (!ret)
 199                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 200         return ret;
 201 }
 202
 203 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 204                                struct ext4_group_desc *bg)
 205 {
 206         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 207                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 208                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 209 }
 210
 211 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 212                                struct ext4_group_desc *bg)
 213 {
 214         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 215                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 216                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 217 }
 218
 219 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 220                               struct ext4_group_desc *bg)
 221 {
 222         return le32_to_cpu(bg->bg_inode_table_lo) |
 223                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 224                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 225 }
 226
 227 __u32 ext4_free_group_clusters(struct super_block *sb,
 228                                struct ext4_group_desc *bg)
 229 {
 230         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 231                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 232                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 233 }
 234
 235 __u32 ext4_free_inodes_count(struct super_block *sb,
 236                               struct ext4_group_desc *bg)
 237 {
 238         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 239                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 240                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 241 }
 242
 243 __u32 ext4_used_dirs_count(struct super_block *sb,
 244                               struct ext4_group_desc *bg)
 245 {
 246         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 247                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 248                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 249 }
 250
 251 __u32 ext4_itable_unused_count(struct super_block *sb,
 252                               struct ext4_group_desc *bg)
 253 {
 254         return le16_to_cpu(bg->bg_itable_unused_lo) |
 255                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 256                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 257 }
 258
 259 void ext4_block_bitmap_set(struct super_block *sb,
 260                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 261 {
 262         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 263         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 264                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 265 }
 266
 267 void ext4_inode_bitmap_set(struct super_block *sb,
 268                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 269 {
 270         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 271         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 272                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 273 }
 274
 275 void ext4_inode_table_set(struct super_block *sb,
 276                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 277 {
 278         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 279         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 280                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 281 }
 282
 283 void ext4_free_group_clusters_set(struct super_block *sb,
 284                                   struct ext4_group_desc *bg, __u32 count)
 285 {
 286         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 287         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 288                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 289 }
 290
 291 void ext4_free_inodes_set(struct super_block *sb,
 292                           struct ext4_group_desc *bg, __u32 count)
 293 {
 294         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 295         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 296                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 297 }
 298
 299 void ext4_used_dirs_set(struct super_block *sb,
 300                           struct ext4_group_desc *bg, __u32 count)
 301 {
 302         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 303         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 304                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 305 }
 306
 307 void ext4_itable_unused_set(struct super_block *sb,
 308                           struct ext4_group_desc *bg, __u32 count)
 309 {
 310         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 311         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 312                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 313 }
 314
 315 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
 316 {
 317         time64_t now = ktime_get_real_seconds();
 318
 319         now = clamp_val(now, 0, (1ull << 40) - 1);
 320
 321         *lo = cpu_to_le32(lower_32_bits(now));
 322         *hi = upper_32_bits(now);
 323 }
 324
 325 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
 326 {
 327         return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
 328 }
 329 #define ext4_update_tstamp(es, tstamp) \
 330         __ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
 331 #define ext4_get_tstamp(es, tstamp) \
 332         __ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
 333
 334 static void __save_error_info(struct super_block *sb, const char *func,
 335                             unsigned int line)
 336 {
 337         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 338
 339         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 340         if (bdev_read_only(sb->s_bdev))
 341                 return;
 342         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 343         ext4_update_tstamp(es, s_last_error_time);
 344         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 345         es->s_last_error_line = cpu_to_le32(line);
 346         if (!es->s_first_error_time) {
 347                 es->s_first_error_time = es->s_last_error_time;
 348                 es->s_first_error_time_hi = es->s_last_error_time_hi;
 349                 strncpy(es->s_first_error_func, func,
 350                         sizeof(es->s_first_error_func));
 351                 es->s_first_error_line = cpu_to_le32(line);
 352                 es->s_first_error_ino = es->s_last_error_ino;
 353                 es->s_first_error_block = es->s_last_error_block;
 354         }
 355         /*
 356          * Start the daily error reporting function if it hasn't been
 357          * started already
 358          */
 359         if (!es->s_error_count)
 360                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 361         le32_add_cpu(&es->s_error_count, 1);
 362 }
 363
 364 static void save_error_info(struct super_block *sb, const char *func,
 365                             unsigned int line)
 366 {
 367         __save_error_info(sb, func, line);
 368         ext4_commit_super(sb, 1);
 369 }
 370
 371 /*
 372  * The del_gendisk() function uninitializes the disk-specific data
 373  * structures, including the bdi structure, without telling anyone
 374  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 375  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 376  * This is a kludge to prevent these oops until we can put in a proper
 377  * hook in del_gendisk() to inform the VFS and file system layers.
 378  */
 379 static int block_device_ejected(struct super_block *sb)
 380 {
 381         struct inode *bd_inode = sb->s_bdev->bd_inode;
 382         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 383
 384         return bdi->dev == NULL;
 385 }
 386
 387 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 388 {
 389         struct super_block              *sb = journal->j_private;
 390         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 391         int                             error = is_journal_aborted(journal);
 392         struct ext4_journal_cb_entry    *jce;
 393
 394         BUG_ON(txn->t_state == T_FINISHED);
 395
 396         ext4_process_freed_data(sb, txn->t_tid);
 397
 398         spin_lock(&sbi->s_md_lock);
 399         while (!list_empty(&txn->t_private_list)) {
 400                 jce = list_entry(txn->t_private_list.next,
 401                                  struct ext4_journal_cb_entry, jce_list);
 402                 list_del_init(&jce->jce_list);
 403                 spin_unlock(&sbi->s_md_lock);
 404                 jce->jce_func(sb, jce, error);
 405                 spin_lock(&sbi->s_md_lock);
 406         }
 407         spin_unlock(&sbi->s_md_lock);
 408 }
 409
 410 /* Deal with the reporting of failure conditions on a filesystem such as
 411  * inconsistencies detected or read IO failures.
 412  *
 413  * On ext2, we can store the error state of the filesystem in the
 414  * superblock.  That is not possible on ext4, because we may have other
 415  * write ordering constraints on the superblock which prevent us from
 416  * writing it out straight away; and given that the journal is about to
 417  * be aborted, we can't rely on the current, or future, transactions to
 418  * write out the superblock safely.
 419  *
 420  * We'll just use the jbd2_journal_abort() error code to record an error in
 421  * the journal instead.  On recovery, the journal will complain about
 422  * that error until we've noted it down and cleared it.
 423  */
 424
 425 static void ext4_handle_error(struct super_block *sb)
 426 {
 427         if (test_opt(sb, WARN_ON_ERROR))
 428                 WARN_ON_ONCE(1);
 429
 430         if (sb_rdonly(sb))
 431                 return;
 432
 433         if (!test_opt(sb, ERRORS_CONT)) {
 434                 journal_t *journal = EXT4_SB(sb)->s_journal;
 435
 436                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 437                 if (journal)
 438                         jbd2_journal_abort(journal, -EIO);
 439         }
 440         if (test_opt(sb, ERRORS_RO)) {
 441                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 442                 /*
 443                  * Make sure updated value of ->s_mount_flags will be visible
 444                  * before ->s_flags update
 445                  */
 446                 smp_wmb();
 447                 sb->s_flags |= SB_RDONLY;
 448         }
 449         if (test_opt(sb, ERRORS_PANIC)) {
 450                 if (EXT4_SB(sb)->s_journal &&
 451                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 452                         return;
 453                 panic("EXT4-fs (device %s): panic forced after error\n",
 454                         sb->s_id);
 455         }
 456 }
 457
 458 #define ext4_error_ratelimit(sb)                                        \
 459                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 460                              "EXT4-fs error")
 461
 462 void __ext4_error(struct super_block *sb, const char *function,
 463                   unsigned int line, const char *fmt, ...)
 464 {
 465         struct va_format vaf;
 466         va_list args;
 467
 468         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 469                 return;
 470
 471         trace_ext4_error(sb, function, line);
 472         if (ext4_error_ratelimit(sb)) {
 473                 va_start(args, fmt);
 474                 vaf.fmt = fmt;
 475                 vaf.va = &args;
 476                 printk(KERN_CRIT
 477                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 478                        sb->s_id, function, line, current->comm, &vaf);
 479                 va_end(args);
 480         }
 481         save_error_info(sb, function, line);
 482         ext4_handle_error(sb);
 483 }
 484
 485 void __ext4_error_inode(struct inode *inode, const char *function,
 486                         unsigned int line, ext4_fsblk_t block,
 487                         const char *fmt, ...)
 488 {
 489         va_list args;
 490         struct va_format vaf;
 491         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 492
 493         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 494                 return;
 495
 496         trace_ext4_error(inode->i_sb, function, line);
 497         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 498         es->s_last_error_block = cpu_to_le64(block);
 499         if (ext4_error_ratelimit(inode->i_sb)) {
 500                 va_start(args, fmt);
 501                 vaf.fmt = fmt;
 502                 vaf.va = &args;
 503                 if (block)
 504                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 505                                "inode #%lu: block %llu: comm %s: %pV\n",
 506                                inode->i_sb->s_id, function, line, inode->i_ino,
 507                                block, current->comm, &vaf);
 508                 else
 509                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 510                                "inode #%lu: comm %s: %pV\n",
 511                                inode->i_sb->s_id, function, line, inode->i_ino,
 512                                current->comm, &vaf);
 513                 va_end(args);
 514         }
 515         save_error_info(inode->i_sb, function, line);
 516         ext4_handle_error(inode->i_sb);
 517 }
 518
 519 void __ext4_error_file(struct file *file, const char *function,
 520                        unsigned int line, ext4_fsblk_t block,
 521                        const char *fmt, ...)
 522 {
 523         va_list args;
 524         struct va_format vaf;
 525         struct ext4_super_block *es;
 526         struct inode *inode = file_inode(file);
 527         char pathname[80], *path;
 528
 529         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 530                 return;
 531
 532         trace_ext4_error(inode->i_sb, function, line);
 533         es = EXT4_SB(inode->i_sb)->s_es;
 534         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 535         if (ext4_error_ratelimit(inode->i_sb)) {
 536                 path = file_path(file, pathname, sizeof(pathname));
 537                 if (IS_ERR(path))
 538                         path = "(unknown)";
 539                 va_start(args, fmt);
 540                 vaf.fmt = fmt;
 541                 vaf.va = &args;
 542                 if (block)
 543                         printk(KERN_CRIT
 544                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 545                                "block %llu: comm %s: path %s: %pV\n",
 546                                inode->i_sb->s_id, function, line, inode->i_ino,
 547                                block, current->comm, path, &vaf);
 548                 else
 549                         printk(KERN_CRIT
 550                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 551                                "comm %s: path %s: %pV\n",
 552                                inode->i_sb->s_id, function, line, inode->i_ino,
 553                                current->comm, path, &vaf);
 554                 va_end(args);
 555         }
 556         save_error_info(inode->i_sb, function, line);
 557         ext4_handle_error(inode->i_sb);
 558 }
 559
 560 const char *ext4_decode_error(struct super_block *sb, int errno,
 561                               char nbuf[16])
 562 {
 563         char *errstr = NULL;
 564
 565         switch (errno) {
 566         case -EFSCORRUPTED:
 567                 errstr = "Corrupt filesystem";
 568                 break;
 569         case -EFSBADCRC:
 570                 errstr = "Filesystem failed CRC";
 571                 break;
 572         case -EIO:
 573                 errstr = "IO failure";
 574                 break;
 575         case -ENOMEM:
 576                 errstr = "Out of memory";
 577                 break;
 578         case -EROFS:
 579                 if (!sb || (EXT4_SB(sb)->s_journal &&
 580                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 581                         errstr = "Journal has aborted";
 582                 else
 583                         errstr = "Readonly filesystem";
 584                 break;
 585         default:
 586                 /* If the caller passed in an extra buffer for unknown
 587                  * errors, textualise them now.  Else we just return
 588                  * NULL. */
 589                 if (nbuf) {
 590                         /* Check for truncated error codes... */
 591                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 592                                 errstr = nbuf;
 593                 }
 594                 break;
 595         }
 596
 597         return errstr;
 598 }
 599
 600 /* __ext4_std_error decodes expected errors from journaling functions
 601  * automatically and invokes the appropriate error response.  */
 602
 603 void __ext4_std_error(struct super_block *sb, const char *function,
 604                       unsigned int line, int errno)
 605 {
 606         char nbuf[16];
 607         const char *errstr;
 608
 609         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 610                 return;
 611
 612         /* Special case: if the error is EROFS, and we're not already
 613          * inside a transaction, then there's really no point in logging
 614          * an error. */
 615         if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
 616                 return;
 617
 618         if (ext4_error_ratelimit(sb)) {
 619                 errstr = ext4_decode_error(sb, errno, nbuf);
 620                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 621                        sb->s_id, function, line, errstr);
 622         }
 623
 624         save_error_info(sb, function, line);
 625         ext4_handle_error(sb);
 626 }
 627
 628 /*
 629  * ext4_abort is a much stronger failure handler than ext4_error.  The
 630  * abort function may be used to deal with unrecoverable failures such
 631  * as journal IO errors or ENOMEM at a critical moment in log management.
 632  *
 633  * We unconditionally force the filesystem into an ABORT|READONLY state,
 634  * unless the error response on the fs has been set to panic in which
 635  * case we take the easy way out and panic immediately.
 636  */
 637
 638 void __ext4_abort(struct super_block *sb, const char *function,
 639                 unsigned int line, const char *fmt, ...)
 640 {
 641         struct va_format vaf;
 642         va_list args;
 643
 644         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 645                 return;
 646
 647         save_error_info(sb, function, line);
 648         va_start(args, fmt);
 649         vaf.fmt = fmt;
 650         vaf.va = &args;
 651         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
 652                sb->s_id, function, line, &vaf);
 653         va_end(args);
 654
 655         if (sb_rdonly(sb) == 0) {
 656                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 657                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 658                 /*
 659                  * Make sure updated value of ->s_mount_flags will be visible
 660                  * before ->s_flags update
 661                  */
 662                 smp_wmb();
 663                 sb->s_flags |= SB_RDONLY;
 664                 if (EXT4_SB(sb)->s_journal)
 665                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 666                 save_error_info(sb, function, line);
 667         }
 668         if (test_opt(sb, ERRORS_PANIC)) {
 669                 if (EXT4_SB(sb)->s_journal &&
 670                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 671                         return;
 672                 panic("EXT4-fs panic from previous error\n");
 673         }
 674 }
 675
 676 void __ext4_msg(struct super_block *sb,
 677                 const char *prefix, const char *fmt, ...)
 678 {
 679         struct va_format vaf;
 680         va_list args;
 681
 682         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 683                 return;
 684
 685         va_start(args, fmt);
 686         vaf.fmt = fmt;
 687         vaf.va = &args;
 688         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 689         va_end(args);
 690 }
 691
 692 #define ext4_warning_ratelimit(sb)                                      \
 693                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 694                              "EXT4-fs warning")
 695
 696 void __ext4_warning(struct super_block *sb, const char *function,
 697                     unsigned int line, const char *fmt, ...)
 698 {
 699         struct va_format vaf;
 700         va_list args;
 701
 702         if (!ext4_warning_ratelimit(sb))
 703                 return;
 704
 705         va_start(args, fmt);
 706         vaf.fmt = fmt;
 707         vaf.va = &args;
 708         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 709                sb->s_id, function, line, &vaf);
 710         va_end(args);
 711 }
 712
 713 void __ext4_warning_inode(const struct inode *inode, const char *function,
 714                           unsigned int line, const char *fmt, ...)
 715 {
 716         struct va_format vaf;
 717         va_list args;
 718
 719         if (!ext4_warning_ratelimit(inode->i_sb))
 720                 return;
 721
 722         va_start(args, fmt);
 723         vaf.fmt = fmt;
 724         vaf.va = &args;
 725         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 726                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 727                function, line, inode->i_ino, current->comm, &vaf);
 728         va_end(args);
 729 }
 730
 731 void __ext4_grp_locked_error(const char *function, unsigned int line,
 732                              struct super_block *sb, ext4_group_t grp,
 733                              unsigned long ino, ext4_fsblk_t block,
 734                              const char *fmt, ...)
 735 __releases(bitlock)
 736 __acquires(bitlock)
 737 {
 738         struct va_format vaf;
 739         va_list args;
 740         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 741
 742         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 743                 return;
 744
 745         trace_ext4_error(sb, function, line);
 746         es->s_last_error_ino = cpu_to_le32(ino);
 747         es->s_last_error_block = cpu_to_le64(block);
 748         __save_error_info(sb, function, line);
 749
 750         if (ext4_error_ratelimit(sb)) {
 751                 va_start(args, fmt);
 752                 vaf.fmt = fmt;
 753                 vaf.va = &args;
 754                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 755                        sb->s_id, function, line, grp);
 756                 if (ino)
 757                         printk(KERN_CONT "inode %lu: ", ino);
 758                 if (block)
 759                         printk(KERN_CONT "block %llu:",
 760                                (unsigned long long) block);
 761                 printk(KERN_CONT "%pV\n", &vaf);
 762                 va_end(args);
 763         }
 764
 765         if (test_opt(sb, WARN_ON_ERROR))
 766                 WARN_ON_ONCE(1);
 767
 768         if (test_opt(sb, ERRORS_CONT)) {
 769                 ext4_commit_super(sb, 0);
 770                 return;
 771         }
 772
 773         ext4_unlock_group(sb, grp);
 774         ext4_commit_super(sb, 1);
 775         ext4_handle_error(sb);
 776         /*
 777          * We only get here in the ERRORS_RO case; relocking the group
 778          * may be dangerous, but nothing bad will happen since the
 779          * filesystem will have already been marked read/only and the
 780          * journal has been aborted.  We return 1 as a hint to callers
 781          * who might what to use the return value from
 782          * ext4_grp_locked_error() to distinguish between the
 783          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 784          * aggressively from the ext4 function in question, with a
 785          * more appropriate error code.
 786          */
 787         ext4_lock_group(sb, grp);
 788         return;
 789 }
 790
 791 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
 792                                      ext4_group_t group,
 793                                      unsigned int flags)
 794 {
 795         struct ext4_sb_info *sbi = EXT4_SB(sb);
 796         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
 797         struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
 798         int ret;
 799
 800         if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
 801                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
 802                                             &grp->bb_state);
 803                 if (!ret)
 804                         percpu_counter_sub(&sbi->s_freeclusters_counter,
 805                                            grp->bb_free);
 806         }
 807
 808         if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
 809                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
 810                                             &grp->bb_state);
 811                 if (!ret && gdp) {
 812                         int count;
 813
 814                         count = ext4_free_inodes_count(sb, gdp);
 815                         percpu_counter_sub(&sbi->s_freeinodes_counter,
 816                                            count);
 817                 }
 818         }
 819 }
 820
 821 void ext4_update_dynamic_rev(struct super_block *sb)
 822 {
 823         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 824
 825         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 826                 return;
 827
 828         ext4_warning(sb,
 829                      "updating to rev %d because of new feature flag, "
 830                      "running e2fsck is recommended",
 831                      EXT4_DYNAMIC_REV);
 832
 833         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 834         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 835         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 836         /* leave es->s_feature_*compat flags alone */
 837         /* es->s_uuid will be set by e2fsck if empty */
 838
 839         /*
 840          * The rest of the superblock fields should be zero, and if not it
 841          * means they are likely already in use, so leave them alone.  We
 842          * can leave it up to e2fsck to clean up any inconsistencies there.
 843          */
 844 }
 845
 846 /*
 847  * Open the external journal device
 848  */
 849 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 850 {
 851         struct block_device *bdev;
 852         char b[BDEVNAME_SIZE];
 853
 854         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 855         if (IS_ERR(bdev))
 856                 goto fail;
 857         return bdev;
 858
 859 fail:
 860         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 861                         __bdevname(dev, b), PTR_ERR(bdev));
 862         return NULL;
 863 }
 864
 865 /*
 866  * Release the journal device
 867  */
 868 static void ext4_blkdev_put(struct block_device *bdev)
 869 {
 870         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 871 }
 872
 873 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 874 {
 875         struct block_device *bdev;
 876         bdev = sbi->journal_bdev;
 877         if (bdev) {
 878                 ext4_blkdev_put(bdev);
 879                 sbi->journal_bdev = NULL;
 880         }
 881 }
 882
 883 static inline struct inode *orphan_list_entry(struct list_head *l)
 884 {
 885         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 886 }
 887
 888 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 889 {
 890         struct list_head *l;
 891
 892         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 893                  le32_to_cpu(sbi->s_es->s_last_orphan));
 894
 895         printk(KERN_ERR "sb_info orphan list:\n");
 896         list_for_each(l, &sbi->s_orphan) {
 897                 struct inode *inode = orphan_list_entry(l);
 898                 printk(KERN_ERR "  "
 899                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 900                        inode->i_sb->s_id, inode->i_ino, inode,
 901                        inode->i_mode, inode->i_nlink,
 902                        NEXT_ORPHAN(inode));
 903         }
 904 }
 905
 906 #ifdef CONFIG_QUOTA
 907 static int ext4_quota_off(struct super_block *sb, int type);
 908
 909 static inline void ext4_quota_off_umount(struct super_block *sb)
 910 {
 911         int type;
 912
 913         /* Use our quota_off function to clear inode flags etc. */
 914         for (type = 0; type < EXT4_MAXQUOTAS; type++)
 915                 ext4_quota_off(sb, type);
 916 }
 917 #else
 918 static inline void ext4_quota_off_umount(struct super_block *sb)
 919 {
 920 }
 921 #endif
 922
 923 static void ext4_put_super(struct super_block *sb)
 924 {
 925         struct ext4_sb_info *sbi = EXT4_SB(sb);
 926         struct ext4_super_block *es = sbi->s_es;
 927         int aborted = 0;
 928         int i, err;
 929
 930         ext4_unregister_li_request(sb);
 931         ext4_quota_off_umount(sb);
 932
 933         destroy_workqueue(sbi->rsv_conversion_wq);
 934
 935         if (sbi->s_journal) {
 936                 aborted = is_journal_aborted(sbi->s_journal);
 937                 err = jbd2_journal_destroy(sbi->s_journal);
 938                 sbi->s_journal = NULL;
 939                 if ((err < 0) && !aborted)
 940                         ext4_abort(sb, "Couldn't clean up the journal");
 941         }
 942
 943         ext4_unregister_sysfs(sb);
 944         ext4_es_unregister_shrinker(sbi);
 945         del_timer_sync(&sbi->s_err_report);
 946         ext4_release_system_zone(sb);
 947         ext4_mb_release(sb);
 948         ext4_ext_release(sb);
 949
 950         if (!sb_rdonly(sb) && !aborted) {
 951                 ext4_clear_feature_journal_needs_recovery(sb);
 952                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 953         }
 954         if (!sb_rdonly(sb))
 955                 ext4_commit_super(sb, 1);
 956
 957         for (i = 0; i < sbi->s_gdb_count; i++)
 958                 brelse(sbi->s_group_desc[i]);
 959         kvfree(sbi->s_group_desc);
 960         kvfree(sbi->s_flex_groups);
 961         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 962         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 963         percpu_counter_destroy(&sbi->s_dirs_counter);
 964         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 965         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 966 #ifdef CONFIG_QUOTA
 967         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 968                 kfree(sbi->s_qf_names[i]);
 969 #endif
 970
 971         /* Debugging code just in case the in-memory inode orphan list
 972          * isn't empty.  The on-disk one can be non-empty if we've
 973          * detected an error and taken the fs readonly, but the
 974          * in-memory list had better be clean by this point. */
 975         if (!list_empty(&sbi->s_orphan))
 976                 dump_orphan_list(sb, sbi);
 977         J_ASSERT(list_empty(&sbi->s_orphan));
 978
 979         sync_blockdev(sb->s_bdev);
 980         invalidate_bdev(sb->s_bdev);
 981         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 982                 /*
 983                  * Invalidate the journal device's buffers.  We don't want them
 984                  * floating about in memory - the physical journal device may
 985                  * hotswapped, and it breaks the `ro-after' testing code.
 986                  */
 987                 sync_blockdev(sbi->journal_bdev);
 988                 invalidate_bdev(sbi->journal_bdev);
 989                 ext4_blkdev_remove(sbi);
 990         }
 991         if (sbi->s_ea_inode_cache) {
 992                 ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
 993                 sbi->s_ea_inode_cache = NULL;
 994         }
 995         if (sbi->s_ea_block_cache) {
 996                 ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
 997                 sbi->s_ea_block_cache = NULL;
 998         }
 999         if (sbi->s_mmp_tsk)
1000                 kthread_stop(sbi->s_mmp_tsk);
1001         brelse(sbi->s_sbh);
1002         sb->s_fs_info = NULL;
1003         /*
1004          * Now that we are completely done shutting down the
1005          * superblock, we need to actually destroy the kobject.
1006          */
1007         kobject_put(&sbi->s_kobj);
1008         wait_for_completion(&sbi->s_kobj_unregister);
1009         if (sbi->s_chksum_driver)
1010                 crypto_free_shash(sbi->s_chksum_driver);
1011         kfree(sbi->s_blockgroup_lock);
1012         fs_put_dax(sbi->s_daxdev);
1013         kfree(sbi);
1014 }
1015
1016 static struct kmem_cache *ext4_inode_cachep;
1017
1018 /*
1019  * Called inside transaction, so use GFP_NOFS
1020  */
1021 static struct inode *ext4_alloc_inode(struct super_block *sb)
1022 {
1023         struct ext4_inode_info *ei;
1024
1025         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1026         if (!ei)
1027                 return NULL;
1028
1029         inode_set_iversion(&ei->vfs_inode, 1);
1030         spin_lock_init(&ei->i_raw_lock);
1031         INIT_LIST_HEAD(&ei->i_prealloc_list);
1032         spin_lock_init(&ei->i_prealloc_lock);
1033         ext4_es_init_tree(&ei->i_es_tree);
1034         rwlock_init(&ei->i_es_lock);
1035         INIT_LIST_HEAD(&ei->i_es_list);
1036         ei->i_es_all_nr = 0;
1037         ei->i_es_shk_nr = 0;
1038         ei->i_es_shrink_lblk = 0;
1039         ei->i_reserved_data_blocks = 0;
1040         ei->i_da_metadata_calc_len = 0;
1041         ei->i_da_metadata_calc_last_lblock = 0;
1042         spin_lock_init(&(ei->i_block_reservation_lock));
1043 #ifdef CONFIG_QUOTA
1044         ei->i_reserved_quota = 0;
1045         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1046 #endif
1047         ei->jinode = NULL;
1048         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1049         spin_lock_init(&ei->i_completed_io_lock);
1050         ei->i_sync_tid = 0;
1051         ei->i_datasync_tid = 0;
1052         atomic_set(&ei->i_unwritten, 0);
1053         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1054         return &ei->vfs_inode;
1055 }
1056
1057 static int ext4_drop_inode(struct inode *inode)
1058 {
1059         int drop = generic_drop_inode(inode);
1060
1061         trace_ext4_drop_inode(inode, drop);
1062         return drop;
1063 }
1064
1065 static void ext4_i_callback(struct rcu_head *head)
1066 {
1067         struct inode *inode = container_of(head, struct inode, i_rcu);
1068         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1069 }
1070
1071 static void ext4_destroy_inode(struct inode *inode)
1072 {
1073         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1074                 ext4_msg(inode->i_sb, KERN_ERR,
1075                          "Inode %lu (%p): orphan list check failed!",
1076                          inode->i_ino, EXT4_I(inode));
1077                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1078                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
1079                                 true);
1080                 dump_stack();
1081         }
1082         call_rcu(&inode->i_rcu, ext4_i_callback);
1083 }
1084
1085 static void init_once(void *foo)
1086 {
1087         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1088
1089         INIT_LIST_HEAD(&ei->i_orphan);
1090         init_rwsem(&ei->xattr_sem);
1091         init_rwsem(&ei->i_data_sem);
1092         init_rwsem(&ei->i_mmap_sem);
1093         inode_init_once(&ei->vfs_inode);
1094 }
1095
1096 static int __init init_inodecache(void)
1097 {
1098         ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1099                                 sizeof(struct ext4_inode_info), 0,
1100                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1101                                         SLAB_ACCOUNT),
1102                                 offsetof(struct ext4_inode_info, i_data),
1103                                 sizeof_field(struct ext4_inode_info, i_data),
1104                                 init_once);
1105         if (ext4_inode_cachep == NULL)
1106                 return -ENOMEM;
1107         return 0;
1108 }
1109
1110 static void destroy_inodecache(void)
1111 {
1112         /*
1113          * Make sure all delayed rcu free inodes are flushed before we
1114          * destroy cache.
1115          */
1116         rcu_barrier();
1117         kmem_cache_destroy(ext4_inode_cachep);
1118 }
1119
1120 void ext4_clear_inode(struct inode *inode)
1121 {
1122         invalidate_inode_buffers(inode);
1123         clear_inode(inode);
1124         dquot_drop(inode);
1125         ext4_discard_preallocations(inode);
1126         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1127         if (EXT4_I(inode)->jinode) {
1128                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1129                                                EXT4_I(inode)->jinode);
1130                 jbd2_free_inode(EXT4_I(inode)->jinode);
1131                 EXT4_I(inode)->jinode = NULL;
1132         }
1133         fscrypt_put_encryption_info(inode);
1134 }
1135
1136 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1137                                         u64 ino, u32 generation)
1138 {
1139         struct inode *inode;
1140
1141         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1142                 return ERR_PTR(-ESTALE);
1143         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1144                 return ERR_PTR(-ESTALE);
1145
1146         /* iget isn't really right if the inode is currently unallocated!!
1147          *
1148          * ext4_read_inode will return a bad_inode if the inode had been
1149          * deleted, so we should be safe.
1150          *
1151          * Currently we don't know the generation for parent directory, so
1152          * a generation of 0 means "accept any"
1153          */
1154         inode = ext4_iget_normal(sb, ino);
1155         if (IS_ERR(inode))
1156                 return ERR_CAST(inode);
1157         if (generation && inode->i_generation != generation) {
1158                 iput(inode);
1159                 return ERR_PTR(-ESTALE);
1160         }
1161
1162         return inode;
1163 }
1164
1165 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1166                                         int fh_len, int fh_type)
1167 {
1168         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1169                                     ext4_nfs_get_inode);
1170 }
1171
1172 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1173                                         int fh_len, int fh_type)
1174 {
1175         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1176                                     ext4_nfs_get_inode);
1177 }
1178
1179 /*
1180  * Try to release metadata pages (indirect blocks, directories) which are
1181  * mapped via the block device.  Since these pages could have journal heads
1182  * which would prevent try_to_free_buffers() from freeing them, we must use
1183  * jbd2 layer's try_to_free_buffers() function to release them.
1184  */
1185 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1186                                  gfp_t wait)
1187 {
1188         journal_t *journal = EXT4_SB(sb)->s_journal;
1189
1190         WARN_ON(PageChecked(page));
1191         if (!page_has_buffers(page))
1192                 return 0;
1193         if (journal)
1194                 return jbd2_journal_try_to_free_buffers(journal, page,
1195                                                 wait & ~__GFP_DIRECT_RECLAIM);
1196         return try_to_free_buffers(page);
1197 }
1198
1199 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1200 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1201 {
1202         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1203                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1204 }
1205
1206 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1207                                                         void *fs_data)
1208 {
1209         handle_t *handle = fs_data;
1210         int res, res2, credits, retries = 0;
1211
1212         /*
1213          * Encrypting the root directory is not allowed because e2fsck expects
1214          * lost+found to exist and be unencrypted, and encrypting the root
1215          * directory would imply encrypting the lost+found directory as well as
1216          * the filename "lost+found" itself.
1217          */
1218         if (inode->i_ino == EXT4_ROOT_INO)
1219                 return -EPERM;
1220
1221         if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1222                 return -EINVAL;
1223
1224         res = ext4_convert_inline_data(inode);
1225         if (res)
1226                 return res;
1227
1228         /*
1229          * If a journal handle was specified, then the encryption context is
1230          * being set on a new inode via inheritance and is part of a larger
1231          * transaction to create the inode.  Otherwise the encryption context is
1232          * being set on an existing inode in its own transaction.  Only in the
1233          * latter case should the "retry on ENOSPC" logic be used.
1234          */
1235
1236         if (handle) {
1237                 res = ext4_xattr_set_handle(handle, inode,
1238                                             EXT4_XATTR_INDEX_ENCRYPTION,
1239                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1240                                             ctx, len, 0);
1241                 if (!res) {
1242                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1243                         ext4_clear_inode_state(inode,
1244                                         EXT4_STATE_MAY_INLINE_DATA);
1245                         /*
1246                          * Update inode->i_flags - S_ENCRYPTED will be enabled,
1247                          * S_DAX may be disabled
1248                          */
1249                         ext4_set_inode_flags(inode);
1250                 }
1251                 return res;
1252         }
1253
1254         res = dquot_initialize(inode);
1255         if (res)
1256                 return res;
1257 retry:
1258         res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1259                                      &credits);
1260         if (res)
1261                 return res;
1262
1263         handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1264         if (IS_ERR(handle))
1265                 return PTR_ERR(handle);
1266
1267         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1268                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1269                                     ctx, len, 0);
1270         if (!res) {
1271                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1272                 /*
1273                  * Update inode->i_flags - S_ENCRYPTED will be enabled,
1274                  * S_DAX may be disabled
1275                  */
1276                 ext4_set_inode_flags(inode);
1277                 res = ext4_mark_inode_dirty(handle, inode);
1278                 if (res)
1279                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1280         }
1281         res2 = ext4_journal_stop(handle);
1282
1283         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1284                 goto retry;
1285         if (!res)
1286                 res = res2;
1287         return res;
1288 }
1289
1290 static bool ext4_dummy_context(struct inode *inode)
1291 {
1292         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1293 }
1294
1295 static const struct fscrypt_operations ext4_cryptops = {
1296         .key_prefix             = "ext4:",
1297         .get_context            = ext4_get_context,
1298         .set_context            = ext4_set_context,
1299         .dummy_context          = ext4_dummy_context,
1300         .empty_dir              = ext4_empty_dir,
1301         .max_namelen            = EXT4_NAME_LEN,
1302 };
1303 #endif
1304
1305 #ifdef CONFIG_QUOTA
1306 static const char * const quotatypes[] = INITQFNAMES;
1307 #define QTYPE2NAME(t) (quotatypes[t])
1308
1309 static int ext4_write_dquot(struct dquot *dquot);
1310 static int ext4_acquire_dquot(struct dquot *dquot);
1311 static int ext4_release_dquot(struct dquot *dquot);
1312 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1313 static int ext4_write_info(struct super_block *sb, int type);
1314 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1315                          const struct path *path);
1316 static int ext4_quota_on_mount(struct super_block *sb, int type);
1317 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1318                                size_t len, loff_t off);
1319 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1320                                 const char *data, size_t len, loff_t off);
1321 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1322                              unsigned int flags);
1323 static int ext4_enable_quotas(struct super_block *sb);
1324 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1325
1326 static struct dquot **ext4_get_dquots(struct inode *inode)
1327 {
1328         return EXT4_I(inode)->i_dquot;
1329 }
1330
1331 static const struct dquot_operations ext4_quota_operations = {
1332         .get_reserved_space     = ext4_get_reserved_space,
1333         .write_dquot            = ext4_write_dquot,
1334         .acquire_dquot          = ext4_acquire_dquot,
1335         .release_dquot          = ext4_release_dquot,
1336         .mark_dirty             = ext4_mark_dquot_dirty,
1337         .write_info             = ext4_write_info,
1338         .alloc_dquot            = dquot_alloc,
1339         .destroy_dquot          = dquot_destroy,
1340         .get_projid             = ext4_get_projid,
1341         .get_inode_usage        = ext4_get_inode_usage,
1342         .get_next_id            = ext4_get_next_id,
1343 };
1344
1345 static const struct quotactl_ops ext4_qctl_operations = {
1346         .quota_on       = ext4_quota_on,
1347         .quota_off      = ext4_quota_off,
1348         .quota_sync     = dquot_quota_sync,
1349         .get_state      = dquot_get_state,
1350         .set_info       = dquot_set_dqinfo,
1351         .get_dqblk      = dquot_get_dqblk,
1352         .set_dqblk      = dquot_set_dqblk,
1353         .get_nextdqblk  = dquot_get_next_dqblk,
1354 };
1355 #endif
1356
1357 static const struct super_operations ext4_sops = {
1358         .alloc_inode    = ext4_alloc_inode,
1359         .destroy_inode  = ext4_destroy_inode,
1360         .write_inode    = ext4_write_inode,
1361         .dirty_inode    = ext4_dirty_inode,
1362         .drop_inode     = ext4_drop_inode,
1363         .evict_inode    = ext4_evict_inode,
1364         .put_super      = ext4_put_super,
1365         .sync_fs        = ext4_sync_fs,
1366         .freeze_fs      = ext4_freeze,
1367         .unfreeze_fs    = ext4_unfreeze,
1368         .statfs         = ext4_statfs,
1369         .remount_fs     = ext4_remount,
1370         .show_options   = ext4_show_options,
1371 #ifdef CONFIG_QUOTA
1372         .quota_read     = ext4_quota_read,
1373         .quota_write    = ext4_quota_write,
1374         .get_dquots     = ext4_get_dquots,
1375 #endif
1376         .bdev_try_to_free_page = bdev_try_to_free_page,
1377 };
1378
1379 static const struct export_operations ext4_export_ops = {
1380         .fh_to_dentry = ext4_fh_to_dentry,
1381         .fh_to_parent = ext4_fh_to_parent,
1382         .get_parent = ext4_get_parent,
1383 };
1384
1385 enum {
1386         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1387         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1388         Opt_nouid32, Opt_debug, Opt_removed,
1389         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1390         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1391         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1392         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1393         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1394         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1395         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1396         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1397         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1398         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1399         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1400         Opt_nowarn_on_error, Opt_mblk_io_submit,
1401         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1402         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1403         Opt_inode_readahead_blks, Opt_journal_ioprio,
1404         Opt_dioread_nolock, Opt_dioread_lock,
1405         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1406         Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1407 };
1408
1409 static const match_table_t tokens = {
1410         {Opt_bsd_df, "bsddf"},
1411         {Opt_minix_df, "minixdf"},
1412         {Opt_grpid, "grpid"},
1413         {Opt_grpid, "bsdgroups"},
1414         {Opt_nogrpid, "nogrpid"},
1415         {Opt_nogrpid, "sysvgroups"},
1416         {Opt_resgid, "resgid=%u"},
1417         {Opt_resuid, "resuid=%u"},
1418         {Opt_sb, "sb=%u"},
1419         {Opt_err_cont, "errors=continue"},
1420         {Opt_err_panic, "errors=panic"},
1421         {Opt_err_ro, "errors=remount-ro"},
1422         {Opt_nouid32, "nouid32"},
1423         {Opt_debug, "debug"},
1424         {Opt_removed, "oldalloc"},
1425         {Opt_removed, "orlov"},
1426         {Opt_user_xattr, "user_xattr"},
1427         {Opt_nouser_xattr, "nouser_xattr"},
1428         {Opt_acl, "acl"},
1429         {Opt_noacl, "noacl"},
1430         {Opt_noload, "norecovery"},
1431         {Opt_noload, "noload"},
1432         {Opt_removed, "nobh"},
1433         {Opt_removed, "bh"},
1434         {Opt_commit, "commit=%u"},
1435         {Opt_min_batch_time, "min_batch_time=%u"},
1436         {Opt_max_batch_time, "max_batch_time=%u"},
1437         {Opt_journal_dev, "journal_dev=%u"},
1438         {Opt_journal_path, "journal_path=%s"},
1439         {Opt_journal_checksum, "journal_checksum"},
1440         {Opt_nojournal_checksum, "nojournal_checksum"},
1441         {Opt_journal_async_commit, "journal_async_commit"},
1442         {Opt_abort, "abort"},
1443         {Opt_data_journal, "data=journal"},
1444         {Opt_data_ordered, "data=ordered"},
1445         {Opt_data_writeback, "data=writeback"},
1446         {Opt_data_err_abort, "data_err=abort"},
1447         {Opt_data_err_ignore, "data_err=ignore"},
1448         {Opt_offusrjquota, "usrjquota="},
1449         {Opt_usrjquota, "usrjquota=%s"},
1450         {Opt_offgrpjquota, "grpjquota="},
1451         {Opt_grpjquota, "grpjquota=%s"},
1452         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1453         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1454         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1455         {Opt_grpquota, "grpquota"},
1456         {Opt_noquota, "noquota"},
1457         {Opt_quota, "quota"},
1458         {Opt_usrquota, "usrquota"},
1459         {Opt_prjquota, "prjquota"},
1460         {Opt_barrier, "barrier=%u"},
1461         {Opt_barrier, "barrier"},
1462         {Opt_nobarrier, "nobarrier"},
1463         {Opt_i_version, "i_version"},
1464         {Opt_dax, "dax"},
1465         {Opt_stripe, "stripe=%u"},
1466         {Opt_delalloc, "delalloc"},
1467         {Opt_warn_on_error, "warn_on_error"},
1468         {Opt_nowarn_on_error, "nowarn_on_error"},
1469         {Opt_lazytime, "lazytime"},
1470         {Opt_nolazytime, "nolazytime"},
1471         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1472         {Opt_nodelalloc, "nodelalloc"},
1473         {Opt_removed, "mblk_io_submit"},
1474         {Opt_removed, "nomblk_io_submit"},
1475         {Opt_block_validity, "block_validity"},
1476         {Opt_noblock_validity, "noblock_validity"},
1477         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1478         {Opt_journal_ioprio, "journal_ioprio=%u"},
1479         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1480         {Opt_auto_da_alloc, "auto_da_alloc"},
1481         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1482         {Opt_dioread_nolock, "dioread_nolock"},
1483         {Opt_dioread_lock, "dioread_lock"},
1484         {Opt_discard, "discard"},
1485         {Opt_nodiscard, "nodiscard"},
1486         {Opt_init_itable, "init_itable=%u"},
1487         {Opt_init_itable, "init_itable"},
1488         {Opt_noinit_itable, "noinit_itable"},
1489         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1490         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1491         {Opt_nombcache, "nombcache"},
1492         {Opt_nombcache, "no_mbcache"},  /* for backward compatibility */
1493         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1494         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1495         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1496         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1497         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1498         {Opt_err, NULL},
1499 };
1500
1501 static ext4_fsblk_t get_sb_block(void **data)
1502 {
1503         ext4_fsblk_t    sb_block;
1504         char            *options = (char *) *data;
1505
1506         if (!options || strncmp(options, "sb=", 3) != 0)
1507                 return 1;       /* Default location */
1508
1509         options += 3;
1510         /* TODO: use simple_strtoll with >32bit ext4 */
1511         sb_block = simple_strtoul(options, &options, 0);
1512         if (*options && *options != ',') {
1513                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1514                        (char *) *data);
1515                 return 1;
1516         }
1517         if (*options == ',')
1518                 options++;
1519         *data = (void *) options;
1520
1521         return sb_block;
1522 }
1523
1524 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1525 static const char deprecated_msg[] =
1526         "Mount option \"%s\" will be removed by %s\n"
1527         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1528
1529 #ifdef CONFIG_QUOTA
1530 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1531 {
1532         struct ext4_sb_info *sbi = EXT4_SB(sb);
1533         char *qname;
1534         int ret = -1;
1535
1536         if (sb_any_quota_loaded(sb) &&
1537                 !sbi->s_qf_names[qtype]) {
1538                 ext4_msg(sb, KERN_ERR,
1539                         "Cannot change journaled "
1540                         "quota options when quota turned on");
1541                 return -1;
1542         }
1543         if (ext4_has_feature_quota(sb)) {
1544                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1545                          "ignored when QUOTA feature is enabled");
1546                 return 1;
1547         }
1548         qname = match_strdup(args);
1549         if (!qname) {
1550                 ext4_msg(sb, KERN_ERR,
1551                         "Not enough memory for storing quotafile name");
1552                 return -1;
1553         }
1554         if (sbi->s_qf_names[qtype]) {
1555                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1556                         ret = 1;
1557                 else
1558                         ext4_msg(sb, KERN_ERR,
1559                                  "%s quota file already specified",
1560                                  QTYPE2NAME(qtype));
1561                 goto errout;
1562         }
1563         if (strchr(qname, '/')) {
1564                 ext4_msg(sb, KERN_ERR,
1565                         "quotafile must be on filesystem root");
1566                 goto errout;
1567         }
1568         sbi->s_qf_names[qtype] = qname;
1569         set_opt(sb, QUOTA);
1570         return 1;
1571 errout:
1572         kfree(qname);
1573         return ret;
1574 }
1575
1576 static int clear_qf_name(struct super_block *sb, int qtype)
1577 {
1578
1579         struct ext4_sb_info *sbi = EXT4_SB(sb);
1580
1581         if (sb_any_quota_loaded(sb) &&
1582                 sbi->s_qf_names[qtype]) {
1583                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1584                         " when quota turned on");
1585                 return -1;
1586         }
1587         kfree(sbi->s_qf_names[qtype]);
1588         sbi->s_qf_names[qtype] = NULL;
1589         return 1;
1590 }
1591 #endif
1592
1593 #define MOPT_SET        0x0001
1594 #define MOPT_CLEAR      0x0002
1595 #define MOPT_NOSUPPORT  0x0004
1596 #define MOPT_EXPLICIT   0x0008
1597 #define MOPT_CLEAR_ERR  0x0010
1598 #define MOPT_GTE0       0x0020
1599 #ifdef CONFIG_QUOTA
1600 #define MOPT_Q          0
1601 #define MOPT_QFMT       0x0040
1602 #else
1603 #define MOPT_Q          MOPT_NOSUPPORT
1604 #define MOPT_QFMT       MOPT_NOSUPPORT
1605 #endif
1606 #define MOPT_DATAJ      0x0080
1607 #define MOPT_NO_EXT2    0x0100
1608 #define MOPT_NO_EXT3    0x0200
1609 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1610 #define MOPT_STRING     0x0400
1611
1612 static const struct mount_opts {
1613         int     token;
1614         int     mount_opt;
1615         int     flags;
1616 } ext4_mount_opts[] = {
1617         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1618         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1619         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1620         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1621         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1622         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1623         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1624          MOPT_EXT4_ONLY | MOPT_SET},
1625         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1626          MOPT_EXT4_ONLY | MOPT_CLEAR},
1627         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1628         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1629         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1630          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1631         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1632          MOPT_EXT4_ONLY | MOPT_CLEAR},
1633         {Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1634         {Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1635         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1636          MOPT_EXT4_ONLY | MOPT_CLEAR},
1637         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1638          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1639         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1640                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1641          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1642         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1643         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1644         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1645         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1646         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1647          MOPT_NO_EXT2},
1648         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1649          MOPT_NO_EXT2},
1650         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1651         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1652         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1653         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1654         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1655         {Opt_commit, 0, MOPT_GTE0},
1656         {Opt_max_batch_time, 0, MOPT_GTE0},
1657         {Opt_min_batch_time, 0, MOPT_GTE0},
1658         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1659         {Opt_init_itable, 0, MOPT_GTE0},
1660         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1661         {Opt_stripe, 0, MOPT_GTE0},
1662         {Opt_resuid, 0, MOPT_GTE0},
1663         {Opt_resgid, 0, MOPT_GTE0},
1664         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1665         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1666         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1667         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1668         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1669         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1670          MOPT_NO_EXT2 | MOPT_DATAJ},
1671         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1672         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1673 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1674         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1675         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1676 #else
1677         {Opt_acl, 0, MOPT_NOSUPPORT},
1678         {Opt_noacl, 0, MOPT_NOSUPPORT},
1679 #endif
1680         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1681         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1682         {Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1683         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1684         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1685                                                         MOPT_SET | MOPT_Q},
1686         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1687                                                         MOPT_SET | MOPT_Q},
1688         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1689                                                         MOPT_SET | MOPT_Q},
1690         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1691                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1692                                                         MOPT_CLEAR | MOPT_Q},
1693         {Opt_usrjquota, 0, MOPT_Q},
1694         {Opt_grpjquota, 0, MOPT_Q},
1695         {Opt_offusrjquota, 0, MOPT_Q},
1696         {Opt_offgrpjquota, 0, MOPT_Q},
1697         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1698         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1699         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1700         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1701         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1702         {Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1703         {Opt_err, 0, 0}
1704 };
1705
1706 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1707                             substring_t *args, unsigned long *journal_devnum,
1708                             unsigned int *journal_ioprio, int is_remount)
1709 {
1710         struct ext4_sb_info *sbi = EXT4_SB(sb);
1711         const struct mount_opts *m;
1712         kuid_t uid;
1713         kgid_t gid;
1714         int arg = 0;
1715
1716 #ifdef CONFIG_QUOTA
1717         if (token == Opt_usrjquota)
1718                 return set_qf_name(sb, USRQUOTA, &args[0]);
1719         else if (token == Opt_grpjquota)
1720                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1721         else if (token == Opt_offusrjquota)
1722                 return clear_qf_name(sb, USRQUOTA);
1723         else if (token == Opt_offgrpjquota)
1724                 return clear_qf_name(sb, GRPQUOTA);
1725 #endif
1726         switch (token) {
1727         case Opt_noacl:
1728         case Opt_nouser_xattr:
1729                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1730                 break;
1731         case Opt_sb:
1732                 return 1;       /* handled by get_sb_block() */
1733         case Opt_removed:
1734                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1735                 return 1;
1736         case Opt_abort:
1737                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1738                 return 1;
1739         case Opt_i_version:
1740                 sb->s_flags |= SB_I_VERSION;
1741                 return 1;
1742         case Opt_lazytime:
1743                 sb->s_flags |= SB_LAZYTIME;
1744                 return 1;
1745         case Opt_nolazytime:
1746                 sb->s_flags &= ~SB_LAZYTIME;
1747                 return 1;
1748         }
1749
1750         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1751                 if (token == m->token)
1752                         break;
1753
1754         if (m->token == Opt_err) {
1755                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1756                          "or missing value", opt);
1757                 return -1;
1758         }
1759
1760         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1761                 ext4_msg(sb, KERN_ERR,
1762                          "Mount option \"%s\" incompatible with ext2", opt);
1763                 return -1;
1764         }
1765         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1766                 ext4_msg(sb, KERN_ERR,
1767                          "Mount option \"%s\" incompatible with ext3", opt);
1768                 return -1;
1769         }
1770
1771         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1772                 return -1;
1773         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1774                 return -1;
1775         if (m->flags & MOPT_EXPLICIT) {
1776                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1777                         set_opt2(sb, EXPLICIT_DELALLOC);
1778                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1779                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1780                 } else
1781                         return -1;
1782         }
1783         if (m->flags & MOPT_CLEAR_ERR)
1784                 clear_opt(sb, ERRORS_MASK);
1785         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1786                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1787                          "options when quota turned on");
1788                 return -1;
1789         }
1790
1791         if (m->flags & MOPT_NOSUPPORT) {
1792                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1793         } else if (token == Opt_commit) {
1794                 if (arg == 0)
1795                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1796                 sbi->s_commit_interval = HZ * arg;
1797         } else if (token == Opt_debug_want_extra_isize) {
1798                 sbi->s_want_extra_isize = arg;
1799         } else if (token == Opt_max_batch_time) {
1800                 sbi->s_max_batch_time = arg;
1801         } else if (token == Opt_min_batch_time) {
1802                 sbi->s_min_batch_time = arg;
1803         } else if (token == Opt_inode_readahead_blks) {
1804                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1805                         ext4_msg(sb, KERN_ERR,
1806                                  "EXT4-fs: inode_readahead_blks must be "
1807                                  "0 or a power of 2 smaller than 2^31");
1808                         return -1;
1809                 }
1810                 sbi->s_inode_readahead_blks = arg;
1811         } else if (token == Opt_init_itable) {
1812                 set_opt(sb, INIT_INODE_TABLE);
1813                 if (!args->from)
1814                         arg = EXT4_DEF_LI_WAIT_MULT;
1815                 sbi->s_li_wait_mult = arg;
1816         } else if (token == Opt_max_dir_size_kb) {
1817                 sbi->s_max_dir_size_kb = arg;
1818         } else if (token == Opt_stripe) {
1819                 sbi->s_stripe = arg;
1820         } else if (token == Opt_resuid) {
1821                 uid = make_kuid(current_user_ns(), arg);
1822                 if (!uid_valid(uid)) {
1823                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1824                         return -1;
1825                 }
1826                 sbi->s_resuid = uid;
1827         } else if (token == Opt_resgid) {
1828                 gid = make_kgid(current_user_ns(), arg);
1829                 if (!gid_valid(gid)) {
1830                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1831                         return -1;
1832                 }
1833                 sbi->s_resgid = gid;
1834         } else if (token == Opt_journal_dev) {
1835                 if (is_remount) {
1836                         ext4_msg(sb, KERN_ERR,
1837                                  "Cannot specify journal on remount");
1838                         return -1;
1839                 }
1840                 *journal_devnum = arg;
1841         } else if (token == Opt_journal_path) {
1842                 char *journal_path;
1843                 struct inode *journal_inode;
1844                 struct path path;
1845                 int error;
1846
1847                 if (is_remount) {
1848                         ext4_msg(sb, KERN_ERR,
1849                                  "Cannot specify journal on remount");
1850                         return -1;
1851                 }
1852                 journal_path = match_strdup(&args[0]);
1853                 if (!journal_path) {
1854                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1855                                 "journal device string");
1856                         return -1;
1857                 }
1858
1859                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1860                 if (error) {
1861                         ext4_msg(sb, KERN_ERR, "error: could not find "
1862                                 "journal device path: error %d", error);
1863                         kfree(journal_path);
1864                         return -1;
1865                 }
1866
1867                 journal_inode = d_inode(path.dentry);
1868                 if (!S_ISBLK(journal_inode->i_mode)) {
1869                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1870                                 "is not a block device", journal_path);
1871                         path_put(&path);
1872                         kfree(journal_path);
1873                         return -1;
1874                 }
1875
1876                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1877                 path_put(&path);
1878                 kfree(journal_path);
1879         } else if (token == Opt_journal_ioprio) {
1880                 if (arg > 7) {
1881                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1882                                  " (must be 0-7)");
1883                         return -1;
1884                 }
1885                 *journal_ioprio =
1886                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1887         } else if (token == Opt_test_dummy_encryption) {
1888 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1889                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1890                 ext4_msg(sb, KERN_WARNING,
1891                          "Test dummy encryption mode enabled");
1892 #else
1893                 ext4_msg(sb, KERN_WARNING,
1894                          "Test dummy encryption mount option ignored");
1895 #endif
1896         } else if (m->flags & MOPT_DATAJ) {
1897                 if (is_remount) {
1898                         if (!sbi->s_journal)
1899                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1900                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1901                                 ext4_msg(sb, KERN_ERR,
1902                                          "Cannot change data mode on remount");
1903                                 return -1;
1904                         }
1905                 } else {
1906                         clear_opt(sb, DATA_FLAGS);
1907                         sbi->s_mount_opt |= m->mount_opt;
1908                 }
1909 #ifdef CONFIG_QUOTA
1910         } else if (m->flags & MOPT_QFMT) {
1911                 if (sb_any_quota_loaded(sb) &&
1912                     sbi->s_jquota_fmt != m->mount_opt) {
1913                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1914                                  "quota options when quota turned on");
1915                         return -1;
1916                 }
1917                 if (ext4_has_feature_quota(sb)) {
1918                         ext4_msg(sb, KERN_INFO,
1919                                  "Quota format mount options ignored "
1920                                  "when QUOTA feature is enabled");
1921                         return 1;
1922                 }
1923                 sbi->s_jquota_fmt = m->mount_opt;
1924 #endif
1925         } else if (token == Opt_dax) {
1926 #ifdef CONFIG_FS_DAX
1927                 ext4_msg(sb, KERN_WARNING,
1928                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1929                         sbi->s_mount_opt |= m->mount_opt;
1930 #else
1931                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1932                 return -1;
1933 #endif
1934         } else if (token == Opt_data_err_abort) {
1935                 sbi->s_mount_opt |= m->mount_opt;
1936         } else if (token == Opt_data_err_ignore) {
1937                 sbi->s_mount_opt &= ~m->mount_opt;
1938         } else {
1939                 if (!args->from)
1940                         arg = 1;
1941                 if (m->flags & MOPT_CLEAR)
1942                         arg = !arg;
1943                 else if (unlikely(!(m->flags & MOPT_SET))) {
1944                         ext4_msg(sb, KERN_WARNING,
1945                                  "buggy handling of option %s", opt);
1946                         WARN_ON(1);
1947                         return -1;
1948                 }
1949                 if (arg != 0)
1950                         sbi->s_mount_opt |= m->mount_opt;
1951                 else
1952                         sbi->s_mount_opt &= ~m->mount_opt;
1953         }
1954         return 1;
1955 }
1956
1957 static int parse_options(char *options, struct super_block *sb,
1958                          unsigned long *journal_devnum,
1959                          unsigned int *journal_ioprio,
1960                          int is_remount)
1961 {
1962         struct ext4_sb_info *sbi = EXT4_SB(sb);
1963         char *p;
1964         substring_t args[MAX_OPT_ARGS];
1965         int token;
1966
1967         if (!options)
1968                 return 1;
1969
1970         while ((p = strsep(&options, ",")) != NULL) {
1971                 if (!*p)
1972                         continue;
1973                 /*
1974                  * Initialize args struct so we know whether arg was
1975                  * found; some options take optional arguments.
1976                  */
1977                 args[0].to = args[0].from = NULL;
1978                 token = match_token(p, tokens, args);
1979                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1980                                      journal_ioprio, is_remount) < 0)
1981                         return 0;
1982         }
1983 #ifdef CONFIG_QUOTA
1984         /*
1985          * We do the test below only for project quotas. 'usrquota' and
1986          * 'grpquota' mount options are allowed even without quota feature
1987          * to support legacy quotas in quota files.
1988          */
1989         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1990                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1991                          "Cannot enable project quota enforcement.");
1992                 return 0;
1993         }
1994         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1995                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1996                         clear_opt(sb, USRQUOTA);
1997
1998                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1999                         clear_opt(sb, GRPQUOTA);
2000
2001                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2002                         ext4_msg(sb, KERN_ERR, "old and new quota "
2003                                         "format mixing");
2004                         return 0;
2005                 }
2006
2007                 if (!sbi->s_jquota_fmt) {
2008                         ext4_msg(sb, KERN_ERR, "journaled quota format "
2009                                         "not specified");
2010                         return 0;
2011                 }
2012         }
2013 #endif
2014         if (test_opt(sb, DIOREAD_NOLOCK)) {
2015                 int blocksize =
2016                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2017
2018                 if (blocksize < PAGE_SIZE) {
2019                         ext4_msg(sb, KERN_ERR, "can't mount with "
2020                                  "dioread_nolock if block size != PAGE_SIZE");
2021                         return 0;
2022                 }
2023         }
2024         return 1;
2025 }
2026
2027 static inline void ext4_show_quota_options(struct seq_file *seq,
2028                                            struct super_block *sb)
2029 {
2030 #if defined(CONFIG_QUOTA)
2031         struct ext4_sb_info *sbi = EXT4_SB(sb);
2032
2033         if (sbi->s_jquota_fmt) {
2034                 char *fmtname = "";
2035
2036                 switch (sbi->s_jquota_fmt) {
2037                 case QFMT_VFS_OLD:
2038                         fmtname = "vfsold";
2039                         break;
2040                 case QFMT_VFS_V0:
2041                         fmtname = "vfsv0";
2042                         break;
2043                 case QFMT_VFS_V1:
2044                         fmtname = "vfsv1";
2045                         break;
2046                 }
2047                 seq_printf(seq, ",jqfmt=%s", fmtname);
2048         }
2049
2050         if (sbi->s_qf_names[USRQUOTA])
2051                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
2052
2053         if (sbi->s_qf_names[GRPQUOTA])
2054                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
2055 #endif
2056 }
2057
2058 static const char *token2str(int token)
2059 {
2060         const struct match_token *t;
2061
2062         for (t = tokens; t->token != Opt_err; t++)
2063                 if (t->token == token && !strchr(t->pattern, '='))
2064                         break;
2065         return t->pattern;
2066 }
2067
2068 /*
2069  * Show an option if
2070  *  - it's set to a non-default value OR
2071  *  - if the per-sb default is different from the global default
2072  */
2073 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2074                               int nodefs)
2075 {
2076         struct ext4_sb_info *sbi = EXT4_SB(sb);
2077         struct ext4_super_block *es = sbi->s_es;
2078         int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2079         const struct mount_opts *m;
2080         char sep = nodefs ? '\n' : ',';
2081
2082 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2083 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2084
2085         if (sbi->s_sb_block != 1)
2086                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2087
2088         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2089                 int want_set = m->flags & MOPT_SET;
2090                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2091                     (m->flags & MOPT_CLEAR_ERR))
2092                         continue;
2093                 if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2094                         continue; /* skip if same as the default */
2095                 if ((want_set &&
2096                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2097                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2098                         continue; /* select Opt_noFoo vs Opt_Foo */
2099                 SEQ_OPTS_PRINT("%s", token2str(m->token));
2100         }
2101
2102         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2103             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2104                 SEQ_OPTS_PRINT("resuid=%u",
2105                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
2106         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2107             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2108                 SEQ_OPTS_PRINT("resgid=%u",
2109                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
2110         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2111         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2112                 SEQ_OPTS_PUTS("errors=remount-ro");
2113         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2114                 SEQ_OPTS_PUTS("errors=continue");
2115         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2116                 SEQ_OPTS_PUTS("errors=panic");
2117         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2118                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2119         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2120                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2121         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2122                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2123         if (sb->s_flags & SB_I_VERSION)
2124                 SEQ_OPTS_PUTS("i_version");
2125         if (nodefs || sbi->s_stripe)
2126                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2127         if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2128                         (sbi->s_mount_opt ^ def_mount_opt)) {
2129                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2130                         SEQ_OPTS_PUTS("data=journal");
2131                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2132                         SEQ_OPTS_PUTS("data=ordered");
2133                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2134                         SEQ_OPTS_PUTS("data=writeback");
2135         }
2136         if (nodefs ||
2137             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2138                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2139                                sbi->s_inode_readahead_blks);
2140
2141         if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2142                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2143                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2144         if (nodefs || sbi->s_max_dir_size_kb)
2145                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2146         if (test_opt(sb, DATA_ERR_ABORT))
2147                 SEQ_OPTS_PUTS("data_err=abort");
2148
2149         ext4_show_quota_options(seq, sb);
2150         return 0;
2151 }
2152
2153 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2154 {
2155         return _ext4_show_options(seq, root->d_sb, 0);
2156 }
2157
2158 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2159 {
2160         struct super_block *sb = seq->private;
2161         int rc;
2162
2163         seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2164         rc = _ext4_show_options(seq, sb, 1);
2165         seq_puts(seq, "\n");
2166         return rc;
2167 }
2168
2169 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2170                             int read_only)
2171 {
2172         struct ext4_sb_info *sbi = EXT4_SB(sb);
2173         int err = 0;
2174
2175         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2176                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2177                          "forcing read-only mode");
2178                 err = -EROFS;
2179         }
2180         if (read_only)
2181                 goto done;
2182         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2183                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2184                          "running e2fsck is recommended");
2185         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2186                 ext4_msg(sb, KERN_WARNING,
2187                          "warning: mounting fs with errors, "
2188                          "running e2fsck is recommended");
2189         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2190                  le16_to_cpu(es->s_mnt_count) >=
2191                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2192                 ext4_msg(sb, KERN_WARNING,
2193                          "warning: maximal mount count reached, "
2194                          "running e2fsck is recommended");
2195         else if (le32_to_cpu(es->s_checkinterval) &&
2196                  (ext4_get_tstamp(es, s_lastcheck) +
2197                   le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2198                 ext4_msg(sb, KERN_WARNING,
2199                          "warning: checktime reached, "
2200                          "running e2fsck is recommended");
2201         if (!sbi->s_journal)
2202                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2203         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2204                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2205         le16_add_cpu(&es->s_mnt_count, 1);
2206         ext4_update_tstamp(es, s_mtime);
2207         ext4_update_dynamic_rev(sb);
2208         if (sbi->s_journal)
2209                 ext4_set_feature_journal_needs_recovery(sb);
2210
2211         err = ext4_commit_super(sb, 1);
2212 done:
2213         if (test_opt(sb, DEBUG))
2214                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2215                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2216                         sb->s_blocksize,
2217                         sbi->s_groups_count,
2218                         EXT4_BLOCKS_PER_GROUP(sb),
2219                         EXT4_INODES_PER_GROUP(sb),
2220                         sbi->s_mount_opt, sbi->s_mount_opt2);
2221
2222         cleancache_init_fs(sb);
2223         return err;
2224 }
2225
2226 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2227 {
2228         struct ext4_sb_info *sbi = EXT4_SB(sb);
2229         struct flex_groups *new_groups;
2230         int size;
2231
2232         if (!sbi->s_log_groups_per_flex)
2233                 return 0;
2234
2235         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2236         if (size <= sbi->s_flex_groups_allocated)
2237                 return 0;
2238
2239         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2240         new_groups = kvzalloc(size, GFP_KERNEL);
2241         if (!new_groups) {
2242                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2243                          size / (int) sizeof(struct flex_groups));
2244                 return -ENOMEM;
2245         }
2246
2247         if (sbi->s_flex_groups) {
2248                 memcpy(new_groups, sbi->s_flex_groups,
2249                        (sbi->s_flex_groups_allocated *
2250                         sizeof(struct flex_groups)));
2251                 kvfree(sbi->s_flex_groups);
2252         }
2253         sbi->s_flex_groups = new_groups;
2254         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2255         return 0;
2256 }
2257
2258 static int ext4_fill_flex_info(struct super_block *sb)
2259 {
2260         struct ext4_sb_info *sbi = EXT4_SB(sb);
2261         struct ext4_group_desc *gdp = NULL;
2262         ext4_group_t flex_group;
2263         int i, err;
2264
2265         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2266         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2267                 sbi->s_log_groups_per_flex = 0;
2268                 return 1;
2269         }
2270
2271         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2272         if (err)
2273                 goto failed;
2274
2275         for (i = 0; i < sbi->s_groups_count; i++) {
2276                 gdp = ext4_get_group_desc(sb, i, NULL);
2277
2278                 flex_group = ext4_flex_group(sbi, i);
2279                 atomic_add(ext4_free_inodes_count(sb, gdp),
2280                            &sbi->s_flex_groups[flex_group].free_inodes);
2281                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2282                              &sbi->s_flex_groups[flex_group].free_clusters);
2283                 atomic_add(ext4_used_dirs_count(sb, gdp),
2284                            &sbi->s_flex_groups[flex_group].used_dirs);
2285         }
2286
2287         return 1;
2288 failed:
2289         return 0;
2290 }
2291
2292 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2293                                    struct ext4_group_desc *gdp)
2294 {
2295         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2296         __u16 crc = 0;
2297         __le32 le_group = cpu_to_le32(block_group);
2298         struct ext4_sb_info *sbi = EXT4_SB(sb);
2299
2300         if (ext4_has_metadata_csum(sbi->s_sb)) {
2301                 /* Use new metadata_csum algorithm */
2302                 __u32 csum32;
2303                 __u16 dummy_csum = 0;
2304
2305                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2306                                      sizeof(le_group));
2307                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2308                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2309                                      sizeof(dummy_csum));
2310                 offset += sizeof(dummy_csum);
2311                 if (offset < sbi->s_desc_size)
2312                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2313                                              sbi->s_desc_size - offset);
2314
2315                 crc = csum32 & 0xFFFF;
2316                 goto out;
2317         }
2318
2319         /* old crc16 code */
2320         if (!ext4_has_feature_gdt_csum(sb))
2321                 return 0;
2322
2323         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2324         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2325         crc = crc16(crc, (__u8 *)gdp, offset);
2326         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2327         /* for checksum of struct ext4_group_desc do the rest...*/
2328         if (ext4_has_feature_64bit(sb) &&
2329             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2330                 crc = crc16(crc, (__u8 *)gdp + offset,
2331                             le16_to_cpu(sbi->s_es->s_desc_size) -
2332                                 offset);
2333
2334 out:
2335         return cpu_to_le16(crc);
2336 }
2337
2338 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2339                                 struct ext4_group_desc *gdp)
2340 {
2341         if (ext4_has_group_desc_csum(sb) &&
2342             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2343                 return 0;
2344
2345         return 1;
2346 }
2347
2348 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2349                               struct ext4_group_desc *gdp)
2350 {
2351         if (!ext4_has_group_desc_csum(sb))
2352                 return;
2353         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2354 }
2355
2356 /* Called at mount-time, super-block is locked */
2357 static int ext4_check_descriptors(struct super_block *sb,
2358                                   ext4_fsblk_t sb_block,
2359                                   ext4_group_t *first_not_zeroed)
2360 {
2361         struct ext4_sb_info *sbi = EXT4_SB(sb);
2362         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2363         ext4_fsblk_t last_block;
2364         ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2365         ext4_fsblk_t block_bitmap;
2366         ext4_fsblk_t inode_bitmap;
2367         ext4_fsblk_t inode_table;
2368         int flexbg_flag = 0;
2369         ext4_group_t i, grp = sbi->s_groups_count;
2370
2371         if (ext4_has_feature_flex_bg(sb))
2372                 flexbg_flag = 1;
2373
2374         ext4_debug("Checking group descriptors");
2375
2376         for (i = 0; i < sbi->s_groups_count; i++) {
2377                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2378
2379                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2380                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2381                 else
2382                         last_block = first_block +
2383                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2384
2385                 if ((grp == sbi->s_groups_count) &&
2386                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2387                         grp = i;
2388
2389                 block_bitmap = ext4_block_bitmap(sb, gdp);
2390                 if (block_bitmap == sb_block) {
2391                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2392                                  "Block bitmap for group %u overlaps "
2393                                  "superblock", i);
2394                         if (!sb_rdonly(sb))
2395                                 return 0;
2396                 }
2397                 if (block_bitmap >= sb_block + 1 &&
2398                     block_bitmap <= last_bg_block) {
2399                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2400                                  "Block bitmap for group %u overlaps "
2401                                  "block group descriptors", i);
2402                         if (!sb_rdonly(sb))
2403                                 return 0;
2404                 }
2405                 if (block_bitmap < first_block || block_bitmap > last_block) {
2406                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2407                                "Block bitmap for group %u not in group "
2408                                "(block %llu)!", i, block_bitmap);
2409                         return 0;
2410                 }
2411                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2412                 if (inode_bitmap == sb_block) {
2413                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2414                                  "Inode bitmap for group %u overlaps "
2415                                  "superblock", i);
2416                         if (!sb_rdonly(sb))
2417                                 return 0;
2418                 }
2419                 if (inode_bitmap >= sb_block + 1 &&
2420                     inode_bitmap <= last_bg_block) {
2421                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2422                                  "Inode bitmap for group %u overlaps "
2423                                  "block group descriptors", i);
2424                         if (!sb_rdonly(sb))
2425                                 return 0;
2426                 }
2427                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2428                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2429                                "Inode bitmap for group %u not in group "
2430                                "(block %llu)!", i, inode_bitmap);
2431                         return 0;
2432                 }
2433                 inode_table = ext4_inode_table(sb, gdp);
2434                 if (inode_table == sb_block) {
2435                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2436                                  "Inode table for group %u overlaps "
2437                                  "superblock", i);
2438                         if (!sb_rdonly(sb))
2439                                 return 0;
2440                 }
2441                 if (inode_table >= sb_block + 1 &&
2442                     inode_table <= last_bg_block) {
2443                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2444                                  "Inode table for group %u overlaps "
2445                                  "block group descriptors", i);
2446                         if (!sb_rdonly(sb))
2447                                 return 0;
2448                 }
2449                 if (inode_table < first_block ||
2450                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2451                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2452                                "Inode table for group %u not in group "
2453                                "(block %llu)!", i, inode_table);
2454                         return 0;
2455                 }
2456                 ext4_lock_group(sb, i);
2457                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2458                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2459                                  "Checksum for group %u failed (%u!=%u)",
2460                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2461                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2462                         if (!sb_rdonly(sb)) {
2463                                 ext4_unlock_group(sb, i);
2464                                 return 0;
2465                         }
2466                 }
2467                 ext4_unlock_group(sb, i);
2468                 if (!flexbg_flag)
2469                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2470         }
2471         if (NULL != first_not_zeroed)
2472                 *first_not_zeroed = grp;
2473         return 1;
2474 }
2475
2476 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2477  * the superblock) which were deleted from all directories, but held open by
2478  * a process at the time of a crash.  We walk the list and try to delete these
2479  * inodes at recovery time (only with a read-write filesystem).
2480  *
2481  * In order to keep the orphan inode chain consistent during traversal (in
2482  * case of crash during recovery), we link each inode into the superblock
2483  * orphan list_head and handle it the same way as an inode deletion during
2484  * normal operation (which journals the operations for us).
2485  *
2486  * We only do an iget() and an iput() on each inode, which is very safe if we
2487  * accidentally point at an in-use or already deleted inode.  The worst that
2488  * can happen in this case is that we get a "bit already cleared" message from
2489  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2490  * e2fsck was run on this filesystem, and it must have already done the orphan
2491  * inode cleanup for us, so we can safely abort without any further action.
2492  */
2493 static void ext4_orphan_cleanup(struct super_block *sb,
2494                                 struct ext4_super_block *es)
2495 {
2496         unsigned int s_flags = sb->s_flags;
2497         int ret, nr_orphans = 0, nr_truncates = 0;
2498 #ifdef CONFIG_QUOTA
2499         int quota_update = 0;
2500         int i;
2501 #endif
2502         if (!es->s_last_orphan) {
2503                 jbd_debug(4, "no orphan inodes to clean up\n");
2504                 return;
2505         }
2506
2507         if (bdev_read_only(sb->s_bdev)) {
2508                 ext4_msg(sb, KERN_ERR, "write access "
2509                         "unavailable, skipping orphan cleanup");
2510                 return;
2511         }
2512
2513         /* Check if feature set would not allow a r/w mount */
2514         if (!ext4_feature_set_ok(sb, 0)) {
2515                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2516                          "unknown ROCOMPAT features");
2517                 return;
2518         }
2519
2520         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2521                 /* don't clear list on RO mount w/ errors */
2522                 if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2523                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2524                                   "clearing orphan list.\n");
2525                         es->s_last_orphan = 0;
2526                 }
2527                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2528                 return;
2529         }
2530
2531         if (s_flags & SB_RDONLY) {
2532                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2533                 sb->s_flags &= ~SB_RDONLY;
2534         }
2535 #ifdef CONFIG_QUOTA
2536         /* Needed for iput() to work correctly and not trash data */
2537         sb->s_flags |= SB_ACTIVE;
2538
2539         /*
2540          * Turn on quotas which were not enabled for read-only mounts if
2541          * filesystem has quota feature, so that they are updated correctly.
2542          */
2543         if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2544                 int ret = ext4_enable_quotas(sb);
2545
2546                 if (!ret)
2547                         quota_update = 1;
2548                 else
2549                         ext4_msg(sb, KERN_ERR,
2550                                 "Cannot turn on quotas: error %d", ret);
2551         }
2552
2553         /* Turn on journaled quotas used for old sytle */
2554         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2555                 if (EXT4_SB(sb)->s_qf_names[i]) {
2556                         int ret = ext4_quota_on_mount(sb, i);
2557
2558                         if (!ret)
2559                                 quota_update = 1;
2560                         else
2561                                 ext4_msg(sb, KERN_ERR,
2562                                         "Cannot turn on journaled "
2563                                         "quota: type %d: error %d", i, ret);
2564                 }
2565         }
2566 #endif
2567
2568         while (es->s_last_orphan) {
2569                 struct inode *inode;
2570
2571                 /*
2572                  * We may have encountered an error during cleanup; if
2573                  * so, skip the rest.
2574                  */
2575                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2576                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2577                         es->s_last_orphan = 0;
2578                         break;
2579                 }
2580
2581                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2582                 if (IS_ERR(inode)) {
2583                         es->s_last_orphan = 0;
2584                         break;
2585                 }
2586
2587                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2588                 dquot_initialize(inode);
2589                 if (inode->i_nlink) {
2590                         if (test_opt(sb, DEBUG))
2591                                 ext4_msg(sb, KERN_DEBUG,
2592                                         "%s: truncating inode %lu to %lld bytes",
2593                                         __func__, inode->i_ino, inode->i_size);
2594                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2595                                   inode->i_ino, inode->i_size);
2596                         inode_lock(inode);
2597                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2598                         ret = ext4_truncate(inode);
2599                         if (ret)
2600                                 ext4_std_error(inode->i_sb, ret);
2601                         inode_unlock(inode);
2602                         nr_truncates++;
2603                 } else {
2604                         if (test_opt(sb, DEBUG))
2605                                 ext4_msg(sb, KERN_DEBUG,
2606                                         "%s: deleting unreferenced inode %lu",
2607                                         __func__, inode->i_ino);
2608                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2609                                   inode->i_ino);
2610                         nr_orphans++;
2611                 }
2612                 iput(inode);  /* The delete magic happens here! */
2613         }
2614
2615 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2616
2617         if (nr_orphans)
2618                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2619                        PLURAL(nr_orphans));
2620         if (nr_truncates)
2621                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2622                        PLURAL(nr_truncates));
2623 #ifdef CONFIG_QUOTA
2624         /* Turn off quotas if they were enabled for orphan cleanup */
2625         if (quota_update) {
2626                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2627                         if (sb_dqopt(sb)->files[i])
2628                                 dquot_quota_off(sb, i);
2629                 }
2630         }
2631 #endif
2632         sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2633 }
2634
2635 /*
2636  * Maximal extent format file size.
2637  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2638  * extent format containers, within a sector_t, and within i_blocks
2639  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2640  * so that won't be a limiting factor.
2641  *
2642  * However there is other limiting factor. We do store extents in the form
2643  * of starting block and length, hence the resulting length of the extent
2644  * covering maximum file size must fit into on-disk format containers as
2645  * well. Given that length is always by 1 unit bigger than max unit (because
2646  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2647  *
2648  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2649  */
2650 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2651 {
2652         loff_t res;
2653         loff_t upper_limit = MAX_LFS_FILESIZE;
2654
2655         /* small i_blocks in vfs inode? */
2656         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2657                 /*
2658                  * CONFIG_LBDAF is not enabled implies the inode
2659                  * i_block represent total blocks in 512 bytes
2660                  * 32 == size of vfs inode i_blocks * 8
2661                  */
2662                 upper_limit = (1LL << 32) - 1;
2663
2664                 /* total blocks in file system block size */
2665                 upper_limit >>= (blkbits - 9);
2666                 upper_limit <<= blkbits;
2667         }
2668
2669         /*
2670          * 32-bit extent-start container, ee_block. We lower the maxbytes
2671          * by one fs block, so ee_len can cover the extent of maximum file
2672          * size
2673          */
2674         res = (1LL << 32) - 1;
2675         res <<= blkbits;
2676
2677         /* Sanity check against vm- & vfs- imposed limits */
2678         if (res > upper_limit)
2679                 res = upper_limit;
2680
2681         return res;
2682 }
2683
2684 /*
2685  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2686  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2687  * We need to be 1 filesystem block less than the 2^48 sector limit.
2688  */
2689 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2690 {
2691         loff_t res = EXT4_NDIR_BLOCKS;
2692         int meta_blocks;
2693         loff_t upper_limit;
2694         /* This is calculated to be the largest file size for a dense, block
2695          * mapped file such that the file's total number of 512-byte sectors,
2696          * including data and all indirect blocks, does not exceed (2^48 - 1).
2697          *
2698          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2699          * number of 512-byte sectors of the file.
2700          */
2701
2702         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2703                 /*
2704                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2705                  * the inode i_block field represents total file blocks in
2706                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2707                  */
2708                 upper_limit = (1LL << 32) - 1;
2709
2710                 /* total blocks in file system block size */
2711                 upper_limit >>= (bits - 9);
2712
2713         } else {
2714                 /*
2715                  * We use 48 bit ext4_inode i_blocks
2716                  * With EXT4_HUGE_FILE_FL set the i_blocks
2717                  * represent total number of blocks in
2718                  * file system block size
2719                  */
2720                 upper_limit = (1LL << 48) - 1;
2721
2722         }
2723
2724         /* indirect blocks */
2725         meta_blocks = 1;
2726         /* double indirect blocks */
2727         meta_blocks += 1 + (1LL << (bits-2));
2728         /* tripple indirect blocks */
2729         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2730
2731         upper_limit -= meta_blocks;
2732         upper_limit <<= bits;
2733
2734         res += 1LL << (bits-2);
2735         res += 1LL << (2*(bits-2));
2736         res += 1LL << (3*(bits-2));
2737         res <<= bits;
2738         if (res > upper_limit)
2739                 res = upper_limit;
2740
2741         if (res > MAX_LFS_FILESIZE)
2742                 res = MAX_LFS_FILESIZE;
2743
2744         return res;
2745 }
2746
2747 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2748                                    ext4_fsblk_t logical_sb_block, int nr)
2749 {
2750         struct ext4_sb_info *sbi = EXT4_SB(sb);
2751         ext4_group_t bg, first_meta_bg;
2752         int has_super = 0;
2753
2754         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2755
2756         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2757                 return logical_sb_block + nr + 1;
2758         bg = sbi->s_desc_per_block * nr;
2759         if (ext4_bg_has_super(sb, bg))
2760                 has_super = 1;
2761
2762         /*
2763          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2764          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2765          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2766          * compensate.
2767          */
2768         if (sb->s_blocksize == 1024 && nr == 0 &&
2769             le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2770                 has_super++;
2771
2772         return (has_super + ext4_group_first_block_no(sb, bg));
2773 }
2774
2775 /**
2776  * ext4_get_stripe_size: Get the stripe size.
2777  * @sbi: In memory super block info
2778  *
2779  * If we have specified it via mount option, then
2780  * use the mount option value. If the value specified at mount time is
2781  * greater than the blocks per group use the super block value.
2782  * If the super block value is greater than blocks per group return 0.
2783  * Allocator needs it be less than blocks per group.
2784  *
2785  */
2786 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2787 {
2788         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2789         unsigned long stripe_width =
2790                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2791         int ret;
2792
2793         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2794                 ret = sbi->s_stripe;
2795         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2796                 ret = stripe_width;
2797         else if (stride && stride <= sbi->s_blocks_per_group)
2798                 ret = stride;
2799         else
2800                 ret = 0;
2801
2802         /*
2803          * If the stripe width is 1, this makes no sense and
2804          * we set it to 0 to turn off stripe handling code.
2805          */
2806         if (ret <= 1)
2807                 ret = 0;
2808
2809         return ret;
2810 }
2811
2812 /*
2813  * Check whether this filesystem can be mounted based on
2814  * the features present and the RDONLY/RDWR mount requested.
2815  * Returns 1 if this filesystem can be mounted as requested,
2816  * 0 if it cannot be.
2817  */
2818 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2819 {
2820         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2821                 ext4_msg(sb, KERN_ERR,
2822                         "Couldn't mount because of "
2823                         "unsupported optional features (%x)",
2824                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2825                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2826                 return 0;
2827         }
2828
2829         if (readonly)
2830                 return 1;
2831
2832         if (ext4_has_feature_readonly(sb)) {
2833                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2834                 sb->s_flags |= SB_RDONLY;
2835                 return 1;
2836         }
2837
2838         /* Check that feature set is OK for a read-write mount */
2839         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2840                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2841                          "unsupported optional features (%x)",
2842                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2843                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2844                 return 0;
2845         }
2846         /*
2847          * Large file size enabled file system can only be mounted
2848          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2849          */
2850         if (ext4_has_feature_huge_file(sb)) {
2851                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2852                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2853                                  "cannot be mounted RDWR without "
2854                                  "CONFIG_LBDAF");
2855                         return 0;
2856                 }
2857         }
2858         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2859                 ext4_msg(sb, KERN_ERR,
2860                          "Can't support bigalloc feature without "
2861                          "extents feature\n");
2862                 return 0;
2863         }
2864
2865 #ifndef CONFIG_QUOTA
2866         if (ext4_has_feature_quota(sb) && !readonly) {
2867                 ext4_msg(sb, KERN_ERR,
2868                          "Filesystem with quota feature cannot be mounted RDWR "
2869                          "without CONFIG_QUOTA");
2870                 return 0;
2871         }
2872         if (ext4_has_feature_project(sb) && !readonly) {
2873                 ext4_msg(sb, KERN_ERR,
2874                          "Filesystem with project quota feature cannot be mounted RDWR "
2875                          "without CONFIG_QUOTA");
2876                 return 0;
2877         }
2878 #endif  /* CONFIG_QUOTA */
2879         return 1;
2880 }
2881
2882 /*
2883  * This function is called once a day if we have errors logged
2884  * on the file system
2885  */
2886 static void print_daily_error_info(struct timer_list *t)
2887 {
2888         struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2889         struct super_block *sb = sbi->s_sb;
2890         struct ext4_super_block *es = sbi->s_es;
2891
2892         if (es->s_error_count)
2893                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2894                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2895                          le32_to_cpu(es->s_error_count));
2896         if (es->s_first_error_time) {
2897                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2898                        sb->s_id,
2899                        ext4_get_tstamp(es, s_first_error_time),
2900                        (int) sizeof(es->s_first_error_func),
2901                        es->s_first_error_func,
2902                        le32_to_cpu(es->s_first_error_line));
2903                 if (es->s_first_error_ino)
2904                         printk(KERN_CONT ": inode %u",
2905                                le32_to_cpu(es->s_first_error_ino));
2906                 if (es->s_first_error_block)
2907                         printk(KERN_CONT ": block %llu", (unsigned long long)
2908                                le64_to_cpu(es->s_first_error_block));
2909                 printk(KERN_CONT "\n");
2910         }
2911         if (es->s_last_error_time) {
2912                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
2913                        sb->s_id,
2914                        ext4_get_tstamp(es, s_last_error_time),
2915                        (int) sizeof(es->s_last_error_func),
2916                        es->s_last_error_func,
2917                        le32_to_cpu(es->s_last_error_line));
2918                 if (es->s_last_error_ino)
2919                         printk(KERN_CONT ": inode %u",
2920                                le32_to_cpu(es->s_last_error_ino));
2921                 if (es->s_last_error_block)
2922                         printk(KERN_CONT ": block %llu", (unsigned long long)
2923                                le64_to_cpu(es->s_last_error_block));
2924                 printk(KERN_CONT "\n");
2925         }
2926         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2927 }
2928
2929 /* Find next suitable group and run ext4_init_inode_table */
2930 static int ext4_run_li_request(struct ext4_li_request *elr)
2931 {
2932         struct ext4_group_desc *gdp = NULL;
2933         ext4_group_t group, ngroups;
2934         struct super_block *sb;
2935         unsigned long timeout = 0;
2936         int ret = 0;
2937
2938         sb = elr->lr_super;
2939         ngroups = EXT4_SB(sb)->s_groups_count;
2940
2941         for (group = elr->lr_next_group; group < ngroups; group++) {
2942                 gdp = ext4_get_group_desc(sb, group, NULL);
2943                 if (!gdp) {
2944                         ret = 1;
2945                         break;
2946                 }
2947
2948                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2949                         break;
2950         }
2951
2952         if (group >= ngroups)
2953                 ret = 1;
2954
2955         if (!ret) {
2956                 timeout = jiffies;
2957                 ret = ext4_init_inode_table(sb, group,
2958                                             elr->lr_timeout ? 0 : 1);
2959                 if (elr->lr_timeout == 0) {
2960                         timeout = (jiffies - timeout) *
2961                                   elr->lr_sbi->s_li_wait_mult;
2962                         elr->lr_timeout = timeout;
2963                 }
2964                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2965                 elr->lr_next_group = group + 1;
2966         }
2967         return ret;
2968 }
2969
2970 /*
2971  * Remove lr_request from the list_request and free the
2972  * request structure. Should be called with li_list_mtx held
2973  */
2974 static void ext4_remove_li_request(struct ext4_li_request *elr)
2975 {
2976         struct ext4_sb_info *sbi;
2977
2978         if (!elr)
2979                 return;
2980
2981         sbi = elr->lr_sbi;
2982
2983         list_del(&elr->lr_request);
2984         sbi->s_li_request = NULL;
2985         kfree(elr);
2986 }
2987
2988 static void ext4_unregister_li_request(struct super_block *sb)
2989 {
2990         mutex_lock(&ext4_li_mtx);
2991         if (!ext4_li_info) {
2992                 mutex_unlock(&ext4_li_mtx);
2993                 return;
2994         }
2995
2996         mutex_lock(&ext4_li_info->li_list_mtx);
2997         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2998         mutex_unlock(&ext4_li_info->li_list_mtx);
2999         mutex_unlock(&ext4_li_mtx);
3000 }
3001
3002 static struct task_struct *ext4_lazyinit_task;
3003
3004 /*
3005  * This is the function where ext4lazyinit thread lives. It walks
3006  * through the request list searching for next scheduled filesystem.
3007  * When such a fs is found, run the lazy initialization request
3008  * (ext4_rn_li_request) and keep track of the time spend in this
3009  * function. Based on that time we compute next schedule time of
3010  * the request. When walking through the list is complete, compute
3011  * next waking time and put itself into sleep.
3012  */
3013 static int ext4_lazyinit_thread(void *arg)
3014 {
3015         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3016         struct list_head *pos, *n;
3017         struct ext4_li_request *elr;
3018         unsigned long next_wakeup, cur;
3019
3020         BUG_ON(NULL == eli);
3021
3022 cont_thread:
3023         while (true) {
3024                 next_wakeup = MAX_JIFFY_OFFSET;
3025
3026                 mutex_lock(&eli->li_list_mtx);
3027                 if (list_empty(&eli->li_request_list)) {
3028                         mutex_unlock(&eli->li_list_mtx);
3029                         goto exit_thread;
3030                 }
3031                 list_for_each_safe(pos, n, &eli->li_request_list) {
3032                         int err = 0;
3033                         int progress = 0;
3034                         elr = list_entry(pos, struct ext4_li_request,
3035                                          lr_request);
3036
3037                         if (time_before(jiffies, elr->lr_next_sched)) {
3038                                 if (time_before(elr->lr_next_sched, next_wakeup))
3039                                         next_wakeup = elr->lr_next_sched;
3040                                 continue;
3041                         }
3042                         if (down_read_trylock(&elr->lr_super->s_umount)) {
3043                                 if (sb_start_write_trylock(elr->lr_super)) {
3044                                         progress = 1;
3045                                         /*
3046                                          * We hold sb->s_umount, sb can not
3047                                          * be removed from the list, it is
3048                                          * now safe to drop li_list_mtx
3049                                          */
3050                                         mutex_unlock(&eli->li_list_mtx);
3051                                         err = ext4_run_li_request(elr);
3052                                         sb_end_write(elr->lr_super);
3053                                         mutex_lock(&eli->li_list_mtx);
3054                                         n = pos->next;
3055                                 }
3056                                 up_read((&elr->lr_super->s_umount));
3057                         }
3058                         /* error, remove the lazy_init job */
3059                         if (err) {
3060                                 ext4_remove_li_request(elr);
3061                                 continue;
3062                         }
3063                         if (!progress) {
3064                                 elr->lr_next_sched = jiffies +
3065                                         (prandom_u32()
3066                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3067                         }
3068                         if (time_before(elr->lr_next_sched, next_wakeup))
3069                                 next_wakeup = elr->lr_next_sched;
3070                 }
3071                 mutex_unlock(&eli->li_list_mtx);
3072
3073                 try_to_freeze();
3074
3075                 cur = jiffies;
3076                 if ((time_after_eq(cur, next_wakeup)) ||
3077                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3078                         cond_resched();
3079                         continue;
3080                 }
3081
3082                 schedule_timeout_interruptible(next_wakeup - cur);
3083
3084                 if (kthread_should_stop()) {
3085                         ext4_clear_request_list();
3086                         goto exit_thread;
3087                 }
3088         }
3089
3090 exit_thread:
3091         /*
3092          * It looks like the request list is empty, but we need
3093          * to check it under the li_list_mtx lock, to prevent any
3094          * additions into it, and of course we should lock ext4_li_mtx
3095          * to atomically free the list and ext4_li_info, because at
3096          * this point another ext4 filesystem could be registering
3097          * new one.
3098          */
3099         mutex_lock(&ext4_li_mtx);
3100         mutex_lock(&eli->li_list_mtx);
3101         if (!list_empty(&eli->li_request_list)) {
3102                 mutex_unlock(&eli->li_list_mtx);
3103                 mutex_unlock(&ext4_li_mtx);
3104                 goto cont_thread;
3105         }
3106         mutex_unlock(&eli->li_list_mtx);
3107         kfree(ext4_li_info);
3108         ext4_li_info = NULL;
3109         mutex_unlock(&ext4_li_mtx);
3110
3111         return 0;
3112 }
3113
3114 static void ext4_clear_request_list(void)
3115 {
3116         struct list_head *pos, *n;
3117         struct ext4_li_request *elr;
3118
3119         mutex_lock(&ext4_li_info->li_list_mtx);
3120         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3121                 elr = list_entry(pos, struct ext4_li_request,
3122                                  lr_request);
3123                 ext4_remove_li_request(elr);
3124         }
3125         mutex_unlock(&ext4_li_info->li_list_mtx);
3126 }
3127
3128 static int ext4_run_lazyinit_thread(void)
3129 {
3130         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3131                                          ext4_li_info, "ext4lazyinit");
3132         if (IS_ERR(ext4_lazyinit_task)) {
3133                 int err = PTR_ERR(ext4_lazyinit_task);
3134                 ext4_clear_request_list();
3135                 kfree(ext4_li_info);
3136                 ext4_li_info = NULL;
3137                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3138                                  "initialization thread\n",
3139                                  err);
3140                 return err;
3141         }
3142         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3143         return 0;
3144 }
3145
3146 /*
3147  * Check whether it make sense to run itable init. thread or not.
3148  * If there is at least one uninitialized inode table, return
3149  * corresponding group number, else the loop goes through all
3150  * groups and return total number of groups.
3151  */
3152 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3153 {
3154         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3155         struct ext4_group_desc *gdp = NULL;
3156
3157         if (!ext4_has_group_desc_csum(sb))
3158                 return ngroups;
3159
3160         for (group = 0; group < ngroups; group++) {
3161                 gdp = ext4_get_group_desc(sb, group, NULL);
3162                 if (!gdp)
3163                         continue;
3164
3165                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3166                         break;
3167         }
3168
3169         return group;
3170 }
3171
3172 static int ext4_li_info_new(void)
3173 {
3174         struct ext4_lazy_init *eli = NULL;
3175
3176         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3177         if (!eli)
3178                 return -ENOMEM;
3179
3180         INIT_LIST_HEAD(&eli->li_request_list);
3181         mutex_init(&eli->li_list_mtx);
3182
3183         eli->li_state |= EXT4_LAZYINIT_QUIT;
3184
3185         ext4_li_info = eli;
3186
3187         return 0;
3188 }
3189
3190 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3191                                             ext4_group_t start)
3192 {
3193         struct ext4_sb_info *sbi = EXT4_SB(sb);
3194         struct ext4_li_request *elr;
3195
3196         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3197         if (!elr)
3198                 return NULL;
3199
3200         elr->lr_super = sb;
3201         elr->lr_sbi = sbi;
3202         elr->lr_next_group = start;
3203
3204         /*
3205          * Randomize first schedule time of the request to
3206          * spread the inode table initialization requests
3207          * better.
3208          */
3209         elr->lr_next_sched = jiffies + (prandom_u32() %
3210                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3211         return elr;
3212 }
3213
3214 int ext4_register_li_request(struct super_block *sb,
3215                              ext4_group_t first_not_zeroed)
3216 {
3217         struct ext4_sb_info *sbi = EXT4_SB(sb);
3218         struct ext4_li_request *elr = NULL;
3219         ext4_group_t ngroups = sbi->s_groups_count;
3220         int ret = 0;
3221
3222         mutex_lock(&ext4_li_mtx);
3223         if (sbi->s_li_request != NULL) {
3224                 /*
3225                  * Reset timeout so it can be computed again, because
3226                  * s_li_wait_mult might have changed.
3227                  */
3228                 sbi->s_li_request->lr_timeout = 0;
3229                 goto out;
3230         }
3231
3232         if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3233             !test_opt(sb, INIT_INODE_TABLE))
3234                 goto out;
3235
3236         elr = ext4_li_request_new(sb, first_not_zeroed);
3237         if (!elr) {
3238                 ret = -ENOMEM;
3239                 goto out;
3240         }
3241
3242         if (NULL == ext4_li_info) {
3243                 ret = ext4_li_info_new();
3244                 if (ret)
3245                         goto out;
3246         }
3247
3248         mutex_lock(&ext4_li_info->li_list_mtx);
3249         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3250         mutex_unlock(&ext4_li_info->li_list_mtx);
3251
3252         sbi->s_li_request = elr;
3253         /*
3254          * set elr to NULL here since it has been inserted to
3255          * the request_list and the removal and free of it is
3256          * handled by ext4_clear_request_list from now on.
3257          */
3258         elr = NULL;
3259
3260         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3261                 ret = ext4_run_lazyinit_thread();
3262                 if (ret)
3263                         goto out;
3264         }
3265 out:
3266         mutex_unlock(&ext4_li_mtx);
3267         if (ret)
3268                 kfree(elr);
3269         return ret;
3270 }
3271
3272 /*
3273  * We do not need to lock anything since this is called on
3274  * module unload.
3275  */
3276 static void ext4_destroy_lazyinit_thread(void)
3277 {
3278         /*
3279          * If thread exited earlier
3280          * there's nothing to be done.
3281          */
3282         if (!ext4_li_info || !ext4_lazyinit_task)
3283                 return;
3284
3285         kthread_stop(ext4_lazyinit_task);
3286 }
3287
3288 static int set_journal_csum_feature_set(struct super_block *sb)
3289 {
3290         int ret = 1;
3291         int compat, incompat;
3292         struct ext4_sb_info *sbi = EXT4_SB(sb);
3293
3294         if (ext4_has_metadata_csum(sb)) {
3295                 /* journal checksum v3 */
3296                 compat = 0;
3297                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3298         } else {
3299                 /* journal checksum v1 */
3300                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3301                 incompat = 0;
3302         }
3303
3304         jbd2_journal_clear_features(sbi->s_journal,
3305                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3306                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3307                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3308         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3309                 ret = jbd2_journal_set_features(sbi->s_journal,
3310                                 compat, 0,
3311                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3312                                 incompat);
3313         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3314                 ret = jbd2_journal_set_features(sbi->s_journal,
3315                                 compat, 0,
3316                                 incompat);
3317                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3318                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3319         } else {
3320                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3321                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3322         }
3323
3324         return ret;
3325 }
3326
3327 /*
3328  * Note: calculating the overhead so we can be compatible with
3329  * historical BSD practice is quite difficult in the face of
3330  * clusters/bigalloc.  This is because multiple metadata blocks from
3331  * different block group can end up in the same allocation cluster.
3332  * Calculating the exact overhead in the face of clustered allocation
3333  * requires either O(all block bitmaps) in memory or O(number of block
3334  * groups**2) in time.  We will still calculate the superblock for
3335  * older file systems --- and if we come across with a bigalloc file
3336  * system with zero in s_overhead_clusters the estimate will be close to
3337  * correct especially for very large cluster sizes --- but for newer
3338  * file systems, it's better to calculate this figure once at mkfs
3339  * time, and store it in the superblock.  If the superblock value is
3340  * present (even for non-bigalloc file systems), we will use it.
3341  */
3342 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3343                           char *buf)
3344 {
3345         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3346         struct ext4_group_desc  *gdp;
3347         ext4_fsblk_t            first_block, last_block, b;
3348         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3349         int                     s, j, count = 0;
3350
3351         if (!ext4_has_feature_bigalloc(sb))
3352                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3353                         sbi->s_itb_per_group + 2);
3354
3355         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3356                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3357         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3358         for (i = 0; i < ngroups; i++) {
3359                 gdp = ext4_get_group_desc(sb, i, NULL);
3360                 b = ext4_block_bitmap(sb, gdp);
3361                 if (b >= first_block && b <= last_block) {
3362                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3363                         count++;
3364                 }
3365                 b = ext4_inode_bitmap(sb, gdp);
3366                 if (b >= first_block && b <= last_block) {
3367                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3368                         count++;
3369                 }
3370                 b = ext4_inode_table(sb, gdp);
3371                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3372                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3373                                 int c = EXT4_B2C(sbi, b - first_block);
3374                                 ext4_set_bit(c, buf);
3375                                 count++;
3376                         }
3377                 if (i != grp)
3378                         continue;
3379                 s = 0;
3380                 if (ext4_bg_has_super(sb, grp)) {
3381                         ext4_set_bit(s++, buf);
3382                         count++;
3383                 }
3384                 j = ext4_bg_num_gdb(sb, grp);
3385                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3386                         ext4_error(sb, "Invalid number of block group "
3387                                    "descriptor blocks: %d", j);
3388                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3389                 }
3390                 count += j;
3391                 for (; j > 0; j--)
3392                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3393         }
3394         if (!count)
3395                 return 0;
3396         return EXT4_CLUSTERS_PER_GROUP(sb) -
3397                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3398 }
3399
3400 /*
3401  * Compute the overhead and stash it in sbi->s_overhead
3402  */
3403 int ext4_calculate_overhead(struct super_block *sb)
3404 {
3405         struct ext4_sb_info *sbi = EXT4_SB(sb);
3406         struct ext4_super_block *es = sbi->s_es;
3407         struct inode *j_inode;
3408         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3409         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3410         ext4_fsblk_t overhead = 0;
3411         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3412
3413         if (!buf)
3414                 return -ENOMEM;
3415
3416         /*
3417          * Compute the overhead (FS structures).  This is constant
3418          * for a given filesystem unless the number of block groups
3419          * changes so we cache the previous value until it does.
3420          */
3421
3422         /*
3423          * All of the blocks before first_data_block are overhead
3424          */
3425         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3426
3427         /*
3428          * Add the overhead found in each block group
3429          */
3430         for (i = 0; i < ngroups; i++) {
3431                 int blks;
3432
3433                 blks = count_overhead(sb, i, buf);
3434                 overhead += blks;
3435                 if (blks)
3436                         memset(buf, 0, PAGE_SIZE);
3437                 cond_resched();
3438         }
3439
3440         /*
3441          * Add the internal journal blocks whether the journal has been
3442          * loaded or not
3443          */
3444         if (sbi->s_journal && !sbi->journal_bdev)
3445                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3446         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3447                 j_inode = ext4_get_journal_inode(sb, j_inum);
3448                 if (j_inode) {
3449                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3450                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3451                         iput(j_inode);
3452                 } else {
3453                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3454                 }
3455         }
3456         sbi->s_overhead = overhead;
3457         smp_wmb();
3458         free_page((unsigned long) buf);
3459         return 0;
3460 }
3461
3462 static void ext4_set_resv_clusters(struct super_block *sb)
3463 {
3464         ext4_fsblk_t resv_clusters;
3465         struct ext4_sb_info *sbi = EXT4_SB(sb);
3466
3467         /*
3468          * There's no need to reserve anything when we aren't using extents.
3469          * The space estimates are exact, there are no unwritten extents,
3470          * hole punching doesn't need new metadata... This is needed especially
3471          * to keep ext2/3 backward compatibility.
3472          */
3473         if (!ext4_has_feature_extents(sb))
3474                 return;
3475         /*
3476          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3477          * This should cover the situations where we can not afford to run
3478          * out of space like for example punch hole, or converting
3479          * unwritten extents in delalloc path. In most cases such
3480          * allocation would require 1, or 2 blocks, higher numbers are
3481          * very rare.
3482          */
3483         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3484                          sbi->s_cluster_bits);
3485
3486         do_div(resv_clusters, 50);
3487         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3488
3489         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3490 }
3491
3492 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3493 {
3494         struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3495         char *orig_data = kstrdup(data, GFP_KERNEL);
3496         struct buffer_head *bh;
3497         struct ext4_super_block *es = NULL;
3498         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3499         ext4_fsblk_t block;
3500         ext4_fsblk_t sb_block = get_sb_block(&data);
3501         ext4_fsblk_t logical_sb_block;
3502         unsigned long offset = 0;
3503         unsigned long journal_devnum = 0;
3504         unsigned long def_mount_opts;
3505         struct inode *root;
3506         const char *descr;
3507         int ret = -ENOMEM;
3508         int blocksize, clustersize;
3509         unsigned int db_count;
3510         unsigned int i;
3511         int needs_recovery, has_huge_files, has_bigalloc;
3512         __u64 blocks_count;
3513         int err = 0;
3514         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3515         ext4_group_t first_not_zeroed;
3516
3517         if ((data && !orig_data) || !sbi)
3518                 goto out_free_base;
3519
3520         sbi->s_daxdev = dax_dev;
3521         sbi->s_blockgroup_lock =
3522                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3523         if (!sbi->s_blockgroup_lock)
3524                 goto out_free_base;
3525
3526         sb->s_fs_info = sbi;
3527         sbi->s_sb = sb;
3528         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3529         sbi->s_sb_block = sb_block;
3530         if (sb->s_bdev->bd_part)
3531                 sbi->s_sectors_written_start =
3532                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3533
3534         /* Cleanup superblock name */
3535         strreplace(sb->s_id, '/', '!');
3536
3537         /* -EINVAL is default */
3538         ret = -EINVAL;
3539         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3540         if (!blocksize) {
3541                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3542                 goto out_fail;
3543         }
3544
3545         /*
3546          * The ext4 superblock will not be buffer aligned for other than 1kB
3547          * block sizes.  We need to calculate the offset from buffer start.
3548          */
3549         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3550                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3551                 offset = do_div(logical_sb_block, blocksize);
3552         } else {
3553                 logical_sb_block = sb_block;
3554         }
3555
3556         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3557                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3558                 goto out_fail;
3559         }
3560         /*
3561          * Note: s_es must be initialized as soon as possible because
3562          *       some ext4 macro-instructions depend on its value
3563          */
3564         es = (struct ext4_super_block *) (bh->b_data + offset);
3565         sbi->s_es = es;
3566         sb->s_magic = le16_to_cpu(es->s_magic);
3567         if (sb->s_magic != EXT4_SUPER_MAGIC)
3568                 goto cantfind_ext4;
3569         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3570
3571         /* Warn if metadata_csum and gdt_csum are both set. */
3572         if (ext4_has_feature_metadata_csum(sb) &&
3573             ext4_has_feature_gdt_csum(sb))
3574                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3575                              "redundant flags; please run fsck.");
3576
3577         /* Check for a known checksum algorithm */
3578         if (!ext4_verify_csum_type(sb, es)) {
3579                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3580                          "unknown checksum algorithm.");
3581                 silent = 1;
3582                 goto cantfind_ext4;
3583         }
3584
3585         /* Load the checksum driver */
3586         sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3587         if (IS_ERR(sbi->s_chksum_driver)) {
3588                 ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3589                 ret = PTR_ERR(sbi->s_chksum_driver);
3590                 sbi->s_chksum_driver = NULL;
3591                 goto failed_mount;
3592         }
3593
3594         /* Check superblock checksum */
3595         if (!ext4_superblock_csum_verify(sb, es)) {
3596                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3597                          "invalid superblock checksum.  Run e2fsck?");
3598                 silent = 1;
3599                 ret = -EFSBADCRC;
3600                 goto cantfind_ext4;
3601         }
3602
3603         /* Precompute checksum seed for all metadata */
3604         if (ext4_has_feature_csum_seed(sb))
3605                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3606         else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3607                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3608                                                sizeof(es->s_uuid));
3609
3610         /* Set defaults before we parse the mount options */
3611         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3612         set_opt(sb, INIT_INODE_TABLE);
3613         if (def_mount_opts & EXT4_DEFM_DEBUG)
3614                 set_opt(sb, DEBUG);
3615         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3616                 set_opt(sb, GRPID);
3617         if (def_mount_opts & EXT4_DEFM_UID16)
3618                 set_opt(sb, NO_UID32);
3619         /* xattr user namespace & acls are now defaulted on */
3620         set_opt(sb, XATTR_USER);
3621 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3622         set_opt(sb, POSIX_ACL);
3623 #endif
3624         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3625         if (ext4_has_metadata_csum(sb))
3626                 set_opt(sb, JOURNAL_CHECKSUM);
3627
3628         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3629                 set_opt(sb, JOURNAL_DATA);
3630         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3631                 set_opt(sb, ORDERED_DATA);
3632         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3633                 set_opt(sb, WRITEBACK_DATA);
3634
3635         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3636                 set_opt(sb, ERRORS_PANIC);
3637         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3638                 set_opt(sb, ERRORS_CONT);
3639         else
3640                 set_opt(sb, ERRORS_RO);
3641         /* block_validity enabled by default; disable with noblock_validity */
3642         set_opt(sb, BLOCK_VALIDITY);
3643         if (def_mount_opts & EXT4_DEFM_DISCARD)
3644                 set_opt(sb, DISCARD);
3645
3646         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3647         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3648         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3649         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3650         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3651
3652         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3653                 set_opt(sb, BARRIER);
3654
3655         /*
3656          * enable delayed allocation by default
3657          * Use -o nodelalloc to turn it off
3658          */
3659         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3660             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3661                 set_opt(sb, DELALLOC);
3662
3663         /*
3664          * set default s_li_wait_mult for lazyinit, for the case there is
3665          * no mount option specified.
3666          */
3667         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3668
3669         if (sbi->s_es->s_mount_opts[0]) {
3670                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3671                                               sizeof(sbi->s_es->s_mount_opts),
3672                                               GFP_KERNEL);
3673                 if (!s_mount_opts)
3674                         goto failed_mount;
3675                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3676                                    &journal_ioprio, 0)) {
3677                         ext4_msg(sb, KERN_WARNING,
3678                                  "failed to parse options in superblock: %s",
3679                                  s_mount_opts);
3680                 }
3681                 kfree(s_mount_opts);
3682         }
3683         sbi->s_def_mount_opt = sbi->s_mount_opt;
3684         if (!parse_options((char *) data, sb, &journal_devnum,
3685                            &journal_ioprio, 0))
3686                 goto failed_mount;
3687
3688         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3689                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3690                             "with data=journal disables delayed "
3691                             "allocation and O_DIRECT support!\n");
3692                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3693                         ext4_msg(sb, KERN_ERR, "can't mount with "
3694                                  "both data=journal and delalloc");
3695                         goto failed_mount;
3696                 }
3697                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3698                         ext4_msg(sb, KERN_ERR, "can't mount with "
3699                                  "both data=journal and dioread_nolock");
3700                         goto failed_mount;
3701                 }
3702                 if (test_opt(sb, DAX)) {
3703                         ext4_msg(sb, KERN_ERR, "can't mount with "
3704                                  "both data=journal and dax");
3705                         goto failed_mount;
3706                 }
3707                 if (ext4_has_feature_encrypt(sb)) {
3708                         ext4_msg(sb, KERN_WARNING,
3709                                  "encrypted files will use data=ordered "
3710                                  "instead of data journaling mode");
3711                 }
3712                 if (test_opt(sb, DELALLOC))
3713                         clear_opt(sb, DELALLOC);
3714         } else {
3715                 sb->s_iflags |= SB_I_CGROUPWB;
3716         }
3717
3718         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3719                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3720
3721         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3722             (ext4_has_compat_features(sb) ||
3723              ext4_has_ro_compat_features(sb) ||
3724              ext4_has_incompat_features(sb)))
3725                 ext4_msg(sb, KERN_WARNING,
3726                        "feature flags set on rev 0 fs, "
3727                        "running e2fsck is recommended");
3728
3729         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3730                 set_opt2(sb, HURD_COMPAT);
3731                 if (ext4_has_feature_64bit(sb)) {
3732                         ext4_msg(sb, KERN_ERR,
3733                                  "The Hurd can't support 64-bit file systems");
3734                         goto failed_mount;
3735                 }
3736
3737                 /*
3738                  * ea_inode feature uses l_i_version field which is not
3739                  * available in HURD_COMPAT mode.
3740                  */
3741                 if (ext4_has_feature_ea_inode(sb)) {
3742                         ext4_msg(sb, KERN_ERR,
3743                                  "ea_inode feature is not supported for Hurd");
3744                         goto failed_mount;
3745                 }
3746         }
3747
3748         if (IS_EXT2_SB(sb)) {
3749                 if (ext2_feature_set_ok(sb))
3750                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3751                                  "using the ext4 subsystem");
3752                 else {
3753                         /*
3754                          * If we're probing be silent, if this looks like
3755                          * it's actually an ext[34] filesystem.
3756                          */
3757                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3758                                 goto failed_mount;
3759                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3760                                  "to feature incompatibilities");
3761                         goto failed_mount;
3762                 }
3763         }
3764
3765         if (IS_EXT3_SB(sb)) {
3766                 if (ext3_feature_set_ok(sb))
3767                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3768                                  "using the ext4 subsystem");
3769                 else {
3770                         /*
3771                          * If we're probing be silent, if this looks like
3772                          * it's actually an ext4 filesystem.
3773                          */
3774                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3775                                 goto failed_mount;
3776                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3777                                  "to feature incompatibilities");
3778                         goto failed_mount;
3779                 }
3780         }
3781
3782         /*
3783          * Check feature flags regardless of the revision level, since we
3784          * previously didn't change the revision level when setting the flags,
3785          * so there is a chance incompat flags are set on a rev 0 filesystem.
3786          */
3787         if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3788                 goto failed_mount;
3789
3790         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3791         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3792             blocksize > EXT4_MAX_BLOCK_SIZE) {
3793                 ext4_msg(sb, KERN_ERR,
3794                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3795                          blocksize, le32_to_cpu(es->s_log_block_size));
3796                 goto failed_mount;
3797         }
3798         if (le32_to_cpu(es->s_log_block_size) >
3799             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3800                 ext4_msg(sb, KERN_ERR,
3801                          "Invalid log block size: %u",
3802                          le32_to_cpu(es->s_log_block_size));
3803                 goto failed_mount;
3804         }
3805         if (le32_to_cpu(es->s_log_cluster_size) >
3806             (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3807                 ext4_msg(sb, KERN_ERR,
3808                          "Invalid log cluster size: %u",
3809                          le32_to_cpu(es->s_log_cluster_size));
3810                 goto failed_mount;
3811         }
3812
3813         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3814                 ext4_msg(sb, KERN_ERR,
3815                          "Number of reserved GDT blocks insanely large: %d",
3816                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3817                 goto failed_mount;
3818         }
3819
3820         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3821                 if (ext4_has_feature_inline_data(sb)) {
3822                         ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3823                                         " that may contain inline data");
3824                         sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3825                 }
3826                 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3827                         ext4_msg(sb, KERN_ERR,
3828                                 "DAX unsupported by block device. Turning off DAX.");
3829                         sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3830                 }
3831         }
3832
3833         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3834                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3835                          es->s_encryption_level);
3836                 goto failed_mount;
3837         }
3838
3839         if (sb->s_blocksize != blocksize) {
3840                 /* Validate the filesystem blocksize */
3841                 if (!sb_set_blocksize(sb, blocksize)) {
3842                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3843                                         blocksize);
3844                         goto failed_mount;
3845                 }
3846
3847                 brelse(bh);
3848                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3849                 offset = do_div(logical_sb_block, blocksize);
3850                 bh = sb_bread_unmovable(sb, logical_sb_block);
3851                 if (!bh) {
3852                         ext4_msg(sb, KERN_ERR,
3853                                "Can't read superblock on 2nd try");
3854                         goto failed_mount;
3855                 }
3856                 es = (struct ext4_super_block *)(bh->b_data + offset);
3857                 sbi->s_es = es;
3858                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3859                         ext4_msg(sb, KERN_ERR,
3860                                "Magic mismatch, very weird!");
3861                         goto failed_mount;
3862                 }
3863         }
3864
3865         has_huge_files = ext4_has_feature_huge_file(sb);
3866         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3867                                                       has_huge_files);
3868         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3869
3870         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3871                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3872                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3873         } else {
3874                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3875                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3876                 if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3877                         ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3878                                  sbi->s_first_ino);
3879                         goto failed_mount;
3880                 }
3881                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3882                     (!is_power_of_2(sbi->s_inode_size)) ||
3883                     (sbi->s_inode_size > blocksize)) {
3884                         ext4_msg(sb, KERN_ERR,
3885                                "unsupported inode size: %d",
3886                                sbi->s_inode_size);
3887                         goto failed_mount;
3888                 }
3889                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3890                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3891         }
3892
3893         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3894         if (ext4_has_feature_64bit(sb)) {
3895                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3896                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3897                     !is_power_of_2(sbi->s_desc_size)) {
3898                         ext4_msg(sb, KERN_ERR,
3899                                "unsupported descriptor size %lu",
3900                                sbi->s_desc_size);
3901                         goto failed_mount;
3902                 }
3903         } else
3904                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3905
3906         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3907         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3908
3909         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3910         if (sbi->s_inodes_per_block == 0)
3911                 goto cantfind_ext4;
3912         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3913             sbi->s_inodes_per_group > blocksize * 8) {
3914                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3915                          sbi->s_blocks_per_group);
3916                 goto failed_mount;
3917         }
3918         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3919                                         sbi->s_inodes_per_block;
3920         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3921         sbi->s_sbh = bh;
3922         sbi->s_mount_state = le16_to_cpu(es->s_state);
3923         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3924         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3925
3926         for (i = 0; i < 4; i++)
3927                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3928         sbi->s_def_hash_version = es->s_def_hash_version;
3929         if (ext4_has_feature_dir_index(sb)) {
3930                 i = le32_to_cpu(es->s_flags);
3931                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3932                         sbi->s_hash_unsigned = 3;
3933                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3934 #ifdef __CHAR_UNSIGNED__
3935                         if (!sb_rdonly(sb))
3936                                 es->s_flags |=
3937                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3938                         sbi->s_hash_unsigned = 3;
3939 #else
3940                         if (!sb_rdonly(sb))
3941                                 es->s_flags |=
3942                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3943 #endif
3944                 }
3945         }
3946
3947         /* Handle clustersize */
3948         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3949         has_bigalloc = ext4_has_feature_bigalloc(sb);
3950         if (has_bigalloc) {
3951                 if (clustersize < blocksize) {
3952                         ext4_msg(sb, KERN_ERR,
3953                                  "cluster size (%d) smaller than "
3954                                  "block size (%d)", clustersize, blocksize);
3955                         goto failed_mount;
3956                 }
3957                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3958                         le32_to_cpu(es->s_log_block_size);
3959                 sbi->s_clusters_per_group =
3960                         le32_to_cpu(es->s_clusters_per_group);
3961                 if (sbi->s_clusters_per_group > blocksize * 8) {
3962                         ext4_msg(sb, KERN_ERR,
3963                                  "#clusters per group too big: %lu",
3964                                  sbi->s_clusters_per_group);
3965                         goto failed_mount;
3966                 }
3967                 if (sbi->s_blocks_per_group !=
3968                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3969                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3970                                  "clusters per group (%lu) inconsistent",
3971                                  sbi->s_blocks_per_group,
3972                                  sbi->s_clusters_per_group);
3973                         goto failed_mount;
3974                 }
3975         } else {
3976                 if (clustersize != blocksize) {
3977                         ext4_msg(sb, KERN_ERR,
3978                                  "fragment/cluster size (%d) != "
3979                                  "block size (%d)", clustersize, blocksize);
3980                         goto failed_mount;
3981                 }
3982                 if (sbi->s_blocks_per_group > blocksize * 8) {
3983                         ext4_msg(sb, KERN_ERR,
3984                                  "#blocks per group too big: %lu",
3985                                  sbi->s_blocks_per_group);
3986                         goto failed_mount;
3987                 }
3988                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3989                 sbi->s_cluster_bits = 0;
3990         }
3991         sbi->s_cluster_ratio = clustersize / blocksize;
3992
3993         /* Do we have standard group size of clustersize * 8 blocks ? */
3994         if (sbi->s_blocks_per_group == clustersize << 3)
3995                 set_opt2(sb, STD_GROUP_SIZE);
3996
3997         /*
3998          * Test whether we have more sectors than will fit in sector_t,
3999          * and whether the max offset is addressable by the page cache.
4000          */
4001         err = generic_check_addressable(sb->s_blocksize_bits,
4002                                         ext4_blocks_count(es));
4003         if (err) {
4004                 ext4_msg(sb, KERN_ERR, "filesystem"
4005                          " too large to mount safely on this system");
4006                 if (sizeof(sector_t) < 8)
4007                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
4008                 goto failed_mount;
4009         }
4010
4011         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4012                 goto cantfind_ext4;
4013
4014         /* check blocks count against device size */
4015         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4016         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4017                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4018                        "exceeds size of device (%llu blocks)",
4019                        ext4_blocks_count(es), blocks_count);
4020                 goto failed_mount;
4021         }
4022
4023         /*
4024          * It makes no sense for the first data block to be beyond the end
4025          * of the filesystem.
4026          */
4027         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4028                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4029                          "block %u is beyond end of filesystem (%llu)",
4030                          le32_to_cpu(es->s_first_data_block),
4031                          ext4_blocks_count(es));
4032                 goto failed_mount;
4033         }
4034         if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4035             (sbi->s_cluster_ratio == 1)) {
4036                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4037                          "block is 0 with a 1k block and cluster size");
4038                 goto failed_mount;
4039         }
4040
4041         blocks_count = (ext4_blocks_count(es) -
4042                         le32_to_cpu(es->s_first_data_block) +
4043                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
4044         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4045         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4046                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4047                        "(block count %llu, first data block %u, "
4048                        "blocks per group %lu)", sbi->s_groups_count,
4049                        ext4_blocks_count(es),
4050                        le32_to_cpu(es->s_first_data_block),
4051                        EXT4_BLOCKS_PER_GROUP(sb));
4052                 goto failed_mount;
4053         }
4054         sbi->s_groups_count = blocks_count;
4055         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4056                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4057         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4058                    EXT4_DESC_PER_BLOCK(sb);
4059         if (ext4_has_feature_meta_bg(sb)) {
4060                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4061                         ext4_msg(sb, KERN_WARNING,
4062                                  "first meta block group too large: %u "
4063                                  "(group descriptor block count %u)",
4064                                  le32_to_cpu(es->s_first_meta_bg), db_count);
4065                         goto failed_mount;
4066                 }
4067         }
4068         sbi->s_group_desc = kvmalloc_array(db_count,
4069                                            sizeof(struct buffer_head *),
4070                                            GFP_KERNEL);
4071         if (sbi->s_group_desc == NULL) {
4072                 ext4_msg(sb, KERN_ERR, "not enough memory");
4073                 ret = -ENOMEM;
4074                 goto failed_mount;
4075         }
4076         if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4077             le32_to_cpu(es->s_inodes_count)) {
4078                 ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4079                          le32_to_cpu(es->s_inodes_count),
4080                          ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4081                 ret = -EINVAL;
4082                 goto failed_mount;
4083         }
4084
4085         bgl_lock_init(sbi->s_blockgroup_lock);
4086
4087         /* Pre-read the descriptors into the buffer cache */
4088         for (i = 0; i < db_count; i++) {
4089                 block = descriptor_loc(sb, logical_sb_block, i);
4090                 sb_breadahead(sb, block);
4091         }
4092
4093         for (i = 0; i < db_count; i++) {
4094                 block = descriptor_loc(sb, logical_sb_block, i);
4095                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4096                 if (!sbi->s_group_desc[i]) {
4097                         ext4_msg(sb, KERN_ERR,
4098                                "can't read group descriptor %d", i);
4099                         db_count = i;
4100                         goto failed_mount2;
4101                 }
4102         }
4103         sbi->s_gdb_count = db_count;
4104         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4105                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4106                 ret = -EFSCORRUPTED;
4107                 goto failed_mount2;
4108         }
4109
4110         timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4111
4112         /* Register extent status tree shrinker */
4113         if (ext4_es_register_shrinker(sbi))
4114                 goto failed_mount3;
4115
4116         sbi->s_stripe = ext4_get_stripe_size(sbi);
4117         sbi->s_extent_max_zeroout_kb = 32;
4118
4119         /*
4120          * set up enough so that it can read an inode
4121          */
4122         sb->s_op = &ext4_sops;
4123         sb->s_export_op = &ext4_export_ops;
4124         sb->s_xattr = ext4_xattr_handlers;
4125 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4126         sb->s_cop = &ext4_cryptops;
4127 #endif
4128 #ifdef CONFIG_QUOTA
4129         sb->dq_op = &ext4_quota_operations;
4130         if (ext4_has_feature_quota(sb))
4131                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
4132         else
4133                 sb->s_qcop = &ext4_qctl_operations;
4134         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4135 #endif
4136         memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4137
4138         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4139         mutex_init(&sbi->s_orphan_lock);
4140
4141         sb->s_root = NULL;
4142
4143         needs_recovery = (es->s_last_orphan != 0 ||
4144                           ext4_has_feature_journal_needs_recovery(sb));
4145
4146         if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4147                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4148                         goto failed_mount3a;
4149
4150         /*
4151          * The first inode we look at is the journal inode.  Don't try
4152          * root first: it may be modified in the journal!
4153          */
4154         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4155                 err = ext4_load_journal(sb, es, journal_devnum);
4156                 if (err)
4157                         goto failed_mount3a;
4158         } else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4159                    ext4_has_feature_journal_needs_recovery(sb)) {
4160                 ext4_msg(sb, KERN_ERR, "required journal recovery "
4161                        "suppressed and not mounted read-only");
4162                 goto failed_mount_wq;
4163         } else {
4164                 /* Nojournal mode, all journal mount options are illegal */
4165                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4166                         ext4_msg(sb, KERN_ERR, "can't mount with "
4167                                  "journal_checksum, fs mounted w/o journal");
4168                         goto failed_mount_wq;
4169                 }
4170                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4171                         ext4_msg(sb, KERN_ERR, "can't mount with "
4172                                  "journal_async_commit, fs mounted w/o journal");
4173                         goto failed_mount_wq;
4174                 }
4175                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4176                         ext4_msg(sb, KERN_ERR, "can't mount with "
4177                                  "commit=%lu, fs mounted w/o journal",
4178                                  sbi->s_commit_interval / HZ);
4179                         goto failed_mount_wq;
4180                 }
4181                 if (EXT4_MOUNT_DATA_FLAGS &
4182                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4183                         ext4_msg(sb, KERN_ERR, "can't mount with "
4184                                  "data=, fs mounted w/o journal");
4185                         goto failed_mount_wq;
4186                 }
4187                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4188                 clear_opt(sb, JOURNAL_CHECKSUM);
4189                 clear_opt(sb, DATA_FLAGS);
4190                 sbi->s_journal = NULL;
4191                 needs_recovery = 0;
4192                 goto no_journal;
4193         }
4194
4195         if (ext4_has_feature_64bit(sb) &&
4196             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4197                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4198                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4199                 goto failed_mount_wq;
4200         }
4201
4202         if (!set_journal_csum_feature_set(sb)) {
4203                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4204                          "feature set");
4205                 goto failed_mount_wq;
4206         }
4207
4208         /* We have now updated the journal if required, so we can
4209          * validate the data journaling mode. */
4210         switch (test_opt(sb, DATA_FLAGS)) {
4211         case 0:
4212                 /* No mode set, assume a default based on the journal
4213                  * capabilities: ORDERED_DATA if the journal can
4214                  * cope, else JOURNAL_DATA
4215                  */
4216                 if (jbd2_journal_check_available_features
4217                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4218                         set_opt(sb, ORDERED_DATA);
4219                         sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4220                 } else {
4221                         set_opt(sb, JOURNAL_DATA);
4222                         sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4223                 }
4224                 break;
4225
4226         case EXT4_MOUNT_ORDERED_DATA:
4227         case EXT4_MOUNT_WRITEBACK_DATA:
4228                 if (!jbd2_journal_check_available_features
4229                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4230                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4231                                "requested data journaling mode");
4232                         goto failed_mount_wq;
4233                 }
4234         default:
4235                 break;
4236         }
4237
4238         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4239             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4240                 ext4_msg(sb, KERN_ERR, "can't mount with "
4241                         "journal_async_commit in data=ordered mode");
4242                 goto failed_mount_wq;
4243         }
4244
4245         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4246
4247         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4248
4249 no_journal:
4250         if (!test_opt(sb, NO_MBCACHE)) {
4251                 sbi->s_ea_block_cache = ext4_xattr_create_cache();
4252                 if (!sbi->s_ea_block_cache) {
4253                         ext4_msg(sb, KERN_ERR,
4254                                  "Failed to create ea_block_cache");
4255                         goto failed_mount_wq;
4256                 }
4257
4258                 if (ext4_has_feature_ea_inode(sb)) {
4259                         sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4260                         if (!sbi->s_ea_inode_cache) {
4261                                 ext4_msg(sb, KERN_ERR,
4262                                          "Failed to create ea_inode_cache");
4263                                 goto failed_mount_wq;
4264                         }
4265                 }
4266         }
4267
4268         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4269             (blocksize != PAGE_SIZE)) {
4270                 ext4_msg(sb, KERN_ERR,
4271                          "Unsupported blocksize for fs encryption");
4272                 goto failed_mount_wq;
4273         }
4274
4275         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4276             !ext4_has_feature_encrypt(sb)) {
4277                 ext4_set_feature_encrypt(sb);
4278                 ext4_commit_super(sb, 1);
4279         }
4280
4281         /*
4282          * Get the # of file system overhead blocks from the
4283          * superblock if present.
4284          */
4285         if (es->s_overhead_clusters)
4286                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4287         else {
4288                 err = ext4_calculate_overhead(sb);
4289                 if (err)
4290                         goto failed_mount_wq;
4291         }
4292
4293         /*
4294          * The maximum number of concurrent works can be high and
4295          * concurrency isn't really necessary.  Limit it to 1.
4296          */
4297         EXT4_SB(sb)->rsv_conversion_wq =
4298                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4299         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4300                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4301                 ret = -ENOMEM;
4302                 goto failed_mount4;
4303         }
4304
4305         /*
4306          * The jbd2_journal_load will have done any necessary log recovery,
4307          * so we can safely mount the rest of the filesystem now.
4308          */
4309
4310         root = ext4_iget(sb, EXT4_ROOT_INO);
4311         if (IS_ERR(root)) {
4312                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4313                 ret = PTR_ERR(root);
4314                 root = NULL;
4315                 goto failed_mount4;
4316         }
4317         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4318                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4319                 iput(root);
4320                 goto failed_mount4;
4321         }
4322         sb->s_root = d_make_root(root);
4323         if (!sb->s_root) {
4324                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4325                 ret = -ENOMEM;
4326                 goto failed_mount4;
4327         }
4328
4329         ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4330         if (ret == -EROFS) {
4331                 sb->s_flags |= SB_RDONLY;
4332                 ret = 0;
4333         } else if (ret)
4334                 goto failed_mount4a;
4335
4336         /* determine the minimum size of new large inodes, if present */
4337         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4338             sbi->s_want_extra_isize == 0) {
4339                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4340                                                      EXT4_GOOD_OLD_INODE_SIZE;
4341                 if (ext4_has_feature_extra_isize(sb)) {
4342                         if (sbi->s_want_extra_isize <
4343                             le16_to_cpu(es->s_want_extra_isize))
4344                                 sbi->s_want_extra_isize =
4345                                         le16_to_cpu(es->s_want_extra_isize);
4346                         if (sbi->s_want_extra_isize <
4347                             le16_to_cpu(es->s_min_extra_isize))
4348                                 sbi->s_want_extra_isize =
4349                                         le16_to_cpu(es->s_min_extra_isize);
4350                 }
4351         }
4352         /* Check if enough inode space is available */
4353         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4354                                                         sbi->s_inode_size) {
4355                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4356                                                        EXT4_GOOD_OLD_INODE_SIZE;
4357                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4358                          "available");
4359         }
4360
4361         ext4_set_resv_clusters(sb);
4362
4363         err = ext4_setup_system_zone(sb);
4364         if (err) {
4365                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4366                          "zone (%d)", err);
4367                 goto failed_mount4a;
4368         }
4369
4370         ext4_ext_init(sb);
4371         err = ext4_mb_init(sb);
4372         if (err) {
4373                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4374                          err);
4375                 goto failed_mount5;
4376         }
4377
4378         block = ext4_count_free_clusters(sb);
4379         ext4_free_blocks_count_set(sbi->s_es,
4380                                    EXT4_C2B(sbi, block));
4381         ext4_superblock_csum_set(sb);
4382         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4383                                   GFP_KERNEL);
4384         if (!err) {
4385                 unsigned long freei = ext4_count_free_inodes(sb);
4386                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4387                 ext4_superblock_csum_set(sb);
4388                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4389                                           GFP_KERNEL);
4390         }
4391         if (!err)
4392                 err = percpu_counter_init(&sbi->s_dirs_counter,
4393                                           ext4_count_dirs(sb), GFP_KERNEL);
4394         if (!err)
4395                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4396                                           GFP_KERNEL);
4397         if (!err)
4398                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4399
4400         if (err) {
4401                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4402                 goto failed_mount6;
4403         }
4404
4405         if (ext4_has_feature_flex_bg(sb))
4406                 if (!ext4_fill_flex_info(sb)) {
4407                         ext4_msg(sb, KERN_ERR,
4408                                "unable to initialize "
4409                                "flex_bg meta info!");
4410                         goto failed_mount6;
4411                 }
4412
4413         err = ext4_register_li_request(sb, first_not_zeroed);
4414         if (err)
4415                 goto failed_mount6;
4416
4417         err = ext4_register_sysfs(sb);
4418         if (err)
4419                 goto failed_mount7;
4420
4421 #ifdef CONFIG_QUOTA
4422         /* Enable quota usage during mount. */
4423         if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4424                 err = ext4_enable_quotas(sb);
4425                 if (err)
4426                         goto failed_mount8;
4427         }
4428 #endif  /* CONFIG_QUOTA */
4429
4430         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4431         ext4_orphan_cleanup(sb, es);
4432         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4433         if (needs_recovery) {
4434                 ext4_msg(sb, KERN_INFO, "recovery complete");
4435                 ext4_mark_recovery_complete(sb, es);
4436         }
4437         if (EXT4_SB(sb)->s_journal) {
4438                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4439                         descr = " journalled data mode";
4440                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4441                         descr = " ordered data mode";
4442                 else
4443                         descr = " writeback data mode";
4444         } else
4445                 descr = "out journal";
4446
4447         if (test_opt(sb, DISCARD)) {
4448                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4449                 if (!blk_queue_discard(q))
4450                         ext4_msg(sb, KERN_WARNING,
4451                                  "mounting with \"discard\" option, but "
4452                                  "the device does not support discard");
4453         }
4454
4455         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4456                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4457                          "Opts: %.*s%s%s", descr,
4458                          (int) sizeof(sbi->s_es->s_mount_opts),
4459                          sbi->s_es->s_mount_opts,
4460                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4461
4462         if (es->s_error_count)
4463                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4464
4465         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4466         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4467         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4468         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4469
4470         kfree(orig_data);
4471         return 0;
4472
4473 cantfind_ext4:
4474         if (!silent)
4475                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4476         goto failed_mount;
4477
4478 #ifdef CONFIG_QUOTA
4479 failed_mount8:
4480         ext4_unregister_sysfs(sb);
4481 #endif
4482 failed_mount7:
4483         ext4_unregister_li_request(sb);
4484 failed_mount6:
4485         ext4_mb_release(sb);
4486         if (sbi->s_flex_groups)
4487                 kvfree(sbi->s_flex_groups);
4488         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4489         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4490         percpu_counter_destroy(&sbi->s_dirs_counter);
4491         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4492 failed_mount5:
4493         ext4_ext_release(sb);
4494         ext4_release_system_zone(sb);
4495 failed_mount4a:
4496         dput(sb->s_root);
4497         sb->s_root = NULL;
4498 failed_mount4:
4499         ext4_msg(sb, KERN_ERR, "mount failed");
4500         if (EXT4_SB(sb)->rsv_conversion_wq)
4501                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4502 failed_mount_wq:
4503         if (sbi->s_ea_inode_cache) {
4504                 ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4505                 sbi->s_ea_inode_cache = NULL;
4506         }
4507         if (sbi->s_ea_block_cache) {
4508                 ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4509                 sbi->s_ea_block_cache = NULL;
4510         }
4511         if (sbi->s_journal) {
4512                 jbd2_journal_destroy(sbi->s_journal);
4513                 sbi->s_journal = NULL;
4514         }
4515 failed_mount3a:
4516         ext4_es_unregister_shrinker(sbi);
4517 failed_mount3:
4518         del_timer_sync(&sbi->s_err_report);
4519         if (sbi->s_mmp_tsk)
4520                 kthread_stop(sbi->s_mmp_tsk);
4521 failed_mount2:
4522         for (i = 0; i < db_count; i++)
4523                 brelse(sbi->s_group_desc[i]);
4524         kvfree(sbi->s_group_desc);
4525 failed_mount:
4526         if (sbi->s_chksum_driver)
4527                 crypto_free_shash(sbi->s_chksum_driver);
4528 #ifdef CONFIG_QUOTA
4529         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4530                 kfree(sbi->s_qf_names[i]);
4531 #endif
4532         ext4_blkdev_remove(sbi);
4533         brelse(bh);
4534 out_fail:
4535         sb->s_fs_info = NULL;
4536         kfree(sbi->s_blockgroup_lock);
4537 out_free_base:
4538         kfree(sbi);
4539         kfree(orig_data);
4540         fs_put_dax(dax_dev);
4541         return err ? err : ret;
4542 }
4543
4544 /*
4545  * Setup any per-fs journal parameters now.  We'll do this both on
4546  * initial mount, once the journal has been initialised but before we've
4547  * done any recovery; and again on any subsequent remount.
4548  */
4549 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4550 {
4551         struct ext4_sb_info *sbi = EXT4_SB(sb);
4552
4553         journal->j_commit_interval = sbi->s_commit_interval;
4554         journal->j_min_batch_time = sbi->s_min_batch_time;
4555         journal->j_max_batch_time = sbi->s_max_batch_time;
4556
4557         write_lock(&journal->j_state_lock);
4558         if (test_opt(sb, BARRIER))
4559                 journal->j_flags |= JBD2_BARRIER;
4560         else
4561                 journal->j_flags &= ~JBD2_BARRIER;
4562         if (test_opt(sb, DATA_ERR_ABORT))
4563                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4564         else
4565                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4566         write_unlock(&journal->j_state_lock);
4567 }
4568
4569 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4570                                              unsigned int journal_inum)
4571 {
4572         struct inode *journal_inode;
4573
4574         /*
4575          * Test for the existence of a valid inode on disk.  Bad things
4576          * happen if we iget() an unused inode, as the subsequent iput()
4577          * will try to delete it.
4578          */
4579         journal_inode = ext4_iget(sb, journal_inum);
4580         if (IS_ERR(journal_inode)) {
4581                 ext4_msg(sb, KERN_ERR, "no journal found");
4582                 return NULL;
4583         }
4584         if (!journal_inode->i_nlink) {
4585                 make_bad_inode(journal_inode);
4586                 iput(journal_inode);
4587                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4588                 return NULL;
4589         }
4590
4591         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4592                   journal_inode, journal_inode->i_size);
4593         if (!S_ISREG(journal_inode->i_mode)) {
4594                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4595                 iput(journal_inode);
4596                 return NULL;
4597         }
4598         return journal_inode;
4599 }
4600
4601 static journal_t *ext4_get_journal(struct super_block *sb,
4602                                    unsigned int journal_inum)
4603 {
4604         struct inode *journal_inode;
4605         journal_t *journal;
4606
4607         BUG_ON(!ext4_has_feature_journal(sb));
4608
4609         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4610         if (!journal_inode)
4611                 return NULL;
4612
4613         journal = jbd2_journal_init_inode(journal_inode);
4614         if (!journal) {
4615                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4616                 iput(journal_inode);
4617                 return NULL;
4618         }
4619         journal->j_private = sb;
4620         ext4_init_journal_params(sb, journal);
4621         return journal;
4622 }
4623
4624 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4625                                        dev_t j_dev)
4626 {
4627         struct buffer_head *bh;
4628         journal_t *journal;
4629         ext4_fsblk_t start;
4630         ext4_fsblk_t len;
4631         int hblock, blocksize;
4632         ext4_fsblk_t sb_block;
4633         unsigned long offset;
4634         struct ext4_super_block *es;
4635         struct block_device *bdev;
4636
4637         BUG_ON(!ext4_has_feature_journal(sb));
4638
4639         bdev = ext4_blkdev_get(j_dev, sb);
4640         if (bdev == NULL)
4641                 return NULL;
4642
4643         blocksize = sb->s_blocksize;
4644         hblock = bdev_logical_block_size(bdev);
4645         if (blocksize < hblock) {
4646                 ext4_msg(sb, KERN_ERR,
4647                         "blocksize too small for journal device");
4648                 goto out_bdev;
4649         }
4650
4651         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4652         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4653         set_blocksize(bdev, blocksize);
4654         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4655                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4656                        "external journal");
4657                 goto out_bdev;
4658         }
4659
4660         es = (struct ext4_super_block *) (bh->b_data + offset);
4661         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4662             !(le32_to_cpu(es->s_feature_incompat) &
4663               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4664                 ext4_msg(sb, KERN_ERR, "external journal has "
4665                                         "bad superblock");
4666                 brelse(bh);
4667                 goto out_bdev;
4668         }
4669
4670         if ((le32_to_cpu(es->s_feature_ro_compat) &
4671              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4672             es->s_checksum != ext4_superblock_csum(sb, es)) {
4673                 ext4_msg(sb, KERN_ERR, "external journal has "
4674                                        "corrupt superblock");
4675                 brelse(bh);
4676                 goto out_bdev;
4677         }
4678
4679         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4680                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4681                 brelse(bh);
4682                 goto out_bdev;
4683         }
4684
4685         len = ext4_blocks_count(es);
4686         start = sb_block + 1;
4687         brelse(bh);     /* we're done with the superblock */
4688
4689         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4690                                         start, len, blocksize);
4691         if (!journal) {
4692                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4693                 goto out_bdev;
4694         }
4695         journal->j_private = sb;
4696         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4697         wait_on_buffer(journal->j_sb_buffer);
4698         if (!buffer_uptodate(journal->j_sb_buffer)) {
4699                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4700                 goto out_journal;
4701         }
4702         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4703                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4704                                         "user (unsupported) - %d",
4705                         be32_to_cpu(journal->j_superblock->s_nr_users));
4706                 goto out_journal;
4707         }
4708         EXT4_SB(sb)->journal_bdev = bdev;
4709         ext4_init_journal_params(sb, journal);
4710         return journal;
4711
4712 out_journal:
4713         jbd2_journal_destroy(journal);
4714 out_bdev:
4715         ext4_blkdev_put(bdev);
4716         return NULL;
4717 }
4718
4719 static int ext4_load_journal(struct super_block *sb,
4720                              struct ext4_super_block *es,
4721                              unsigned long journal_devnum)
4722 {
4723         journal_t *journal;
4724         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4725         dev_t journal_dev;
4726         int err = 0;
4727         int really_read_only;
4728
4729         BUG_ON(!ext4_has_feature_journal(sb));
4730
4731         if (journal_devnum &&
4732             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4733                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4734                         "numbers have changed");
4735                 journal_dev = new_decode_dev(journal_devnum);
4736         } else
4737                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4738
4739         really_read_only = bdev_read_only(sb->s_bdev);
4740
4741         /*
4742          * Are we loading a blank journal or performing recovery after a
4743          * crash?  For recovery, we need to check in advance whether we
4744          * can get read-write access to the device.
4745          */
4746         if (ext4_has_feature_journal_needs_recovery(sb)) {
4747                 if (sb_rdonly(sb)) {
4748                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4749                                         "required on readonly filesystem");
4750                         if (really_read_only) {
4751                                 ext4_msg(sb, KERN_ERR, "write access "
4752                                         "unavailable, cannot proceed "
4753                                         "(try mounting with noload)");
4754                                 return -EROFS;
4755                         }
4756                         ext4_msg(sb, KERN_INFO, "write access will "
4757                                "be enabled during recovery");
4758                 }
4759         }
4760
4761         if (journal_inum && journal_dev) {
4762                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4763                        "and inode journals!");
4764                 return -EINVAL;
4765         }
4766
4767         if (journal_inum) {
4768                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4769                         return -EINVAL;
4770         } else {
4771                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4772                         return -EINVAL;
4773         }
4774
4775         if (!(journal->j_flags & JBD2_BARRIER))
4776                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4777
4778         if (!ext4_has_feature_journal_needs_recovery(sb))
4779                 err = jbd2_journal_wipe(journal, !really_read_only);
4780         if (!err) {
4781                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4782                 if (save)
4783                         memcpy(save, ((char *) es) +
4784                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4785                 err = jbd2_journal_load(journal);
4786                 if (save)
4787                         memcpy(((char *) es) + EXT4_S_ERR_START,
4788                                save, EXT4_S_ERR_LEN);
4789                 kfree(save);
4790         }
4791
4792         if (err) {
4793                 ext4_msg(sb, KERN_ERR, "error loading journal");
4794                 jbd2_journal_destroy(journal);
4795                 return err;
4796         }
4797
4798         EXT4_SB(sb)->s_journal = journal;
4799         ext4_clear_journal_err(sb, es);
4800
4801         if (!really_read_only && journal_devnum &&
4802             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4803                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4804
4805                 /* Make sure we flush the recovery flag to disk. */
4806                 ext4_commit_super(sb, 1);
4807         }
4808
4809         return 0;
4810 }
4811
4812 static int ext4_commit_super(struct super_block *sb, int sync)
4813 {
4814         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4815         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4816         int error = 0;
4817
4818         if (!sbh || block_device_ejected(sb))
4819                 return error;
4820
4821         /*
4822          * The superblock bh should be mapped, but it might not be if the
4823          * device was hot-removed. Not much we can do but fail the I/O.
4824          */
4825         if (!buffer_mapped(sbh))
4826                 return error;
4827
4828         /*
4829          * If the file system is mounted read-only, don't update the
4830          * superblock write time.  This avoids updating the superblock
4831          * write time when we are mounting the root file system
4832          * read/only but we need to replay the journal; at that point,
4833          * for people who are east of GMT and who make their clock
4834          * tick in localtime for Windows bug-for-bug compatibility,
4835          * the clock is set in the future, and this will cause e2fsck
4836          * to complain and force a full file system check.
4837          */
4838         if (!(sb->s_flags & SB_RDONLY))
4839                 ext4_update_tstamp(es, s_wtime);
4840         if (sb->s_bdev->bd_part)
4841                 es->s_kbytes_written =
4842                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4843                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4844                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4845         else
4846                 es->s_kbytes_written =
4847                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4848         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4849                 ext4_free_blocks_count_set(es,
4850                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4851                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4852         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4853                 es->s_free_inodes_count =
4854                         cpu_to_le32(percpu_counter_sum_positive(
4855                                 &EXT4_SB(sb)->s_freeinodes_counter));
4856         BUFFER_TRACE(sbh, "marking dirty");
4857         ext4_superblock_csum_set(sb);
4858         if (sync)
4859                 lock_buffer(sbh);
4860         if (buffer_write_io_error(sbh)) {
4861                 /*
4862                  * Oh, dear.  A previous attempt to write the
4863                  * superblock failed.  This could happen because the
4864                  * USB device was yanked out.  Or it could happen to
4865                  * be a transient write error and maybe the block will
4866                  * be remapped.  Nothing we can do but to retry the
4867                  * write and hope for the best.
4868                  */
4869                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4870                        "superblock detected");
4871                 clear_buffer_write_io_error(sbh);
4872                 set_buffer_uptodate(sbh);
4873         }
4874         mark_buffer_dirty(sbh);
4875         if (sync) {
4876                 unlock_buffer(sbh);
4877                 error = __sync_dirty_buffer(sbh,
4878                         REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4879                 if (buffer_write_io_error(sbh)) {
4880                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4881                                "superblock");
4882                         clear_buffer_write_io_error(sbh);
4883                         set_buffer_uptodate(sbh);
4884                 }
4885         }
4886         return error;
4887 }
4888
4889 /*
4890  * Have we just finished recovery?  If so, and if we are mounting (or
4891  * remounting) the filesystem readonly, then we will end up with a
4892  * consistent fs on disk.  Record that fact.
4893  */
4894 static void ext4_mark_recovery_complete(struct super_block *sb,
4895                                         struct ext4_super_block *es)
4896 {
4897         journal_t *journal = EXT4_SB(sb)->s_journal;
4898
4899         if (!ext4_has_feature_journal(sb)) {
4900                 BUG_ON(journal != NULL);
4901                 return;
4902         }
4903         jbd2_journal_lock_updates(journal);
4904         if (jbd2_journal_flush(journal) < 0)
4905                 goto out;
4906
4907         if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4908                 ext4_clear_feature_journal_needs_recovery(sb);
4909                 ext4_commit_super(sb, 1);
4910         }
4911
4912 out:
4913         jbd2_journal_unlock_updates(journal);
4914 }
4915
4916 /*
4917  * If we are mounting (or read-write remounting) a filesystem whose journal
4918  * has recorded an error from a previous lifetime, move that error to the
4919  * main filesystem now.
4920  */
4921 static void ext4_clear_journal_err(struct super_block *sb,
4922                                    struct ext4_super_block *es)
4923 {
4924         journal_t *journal;
4925         int j_errno;
4926         const char *errstr;
4927
4928         BUG_ON(!ext4_has_feature_journal(sb));
4929
4930         journal = EXT4_SB(sb)->s_journal;
4931
4932         /*
4933          * Now check for any error status which may have been recorded in the
4934          * journal by a prior ext4_error() or ext4_abort()
4935          */
4936
4937         j_errno = jbd2_journal_errno(journal);
4938         if (j_errno) {
4939                 char nbuf[16];
4940
4941                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4942                 ext4_warning(sb, "Filesystem error recorded "
4943                              "from previous mount: %s", errstr);
4944                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4945
4946                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4947                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4948                 ext4_commit_super(sb, 1);
4949
4950                 jbd2_journal_clear_err(journal);
4951                 jbd2_journal_update_sb_errno(journal);
4952         }
4953 }
4954
4955 /*
4956  * Force the running and committing transactions to commit,
4957  * and wait on the commit.
4958  */
4959 int ext4_force_commit(struct super_block *sb)
4960 {
4961         journal_t *journal;
4962
4963         if (sb_rdonly(sb))
4964                 return 0;
4965
4966         journal = EXT4_SB(sb)->s_journal;
4967         return ext4_journal_force_commit(journal);
4968 }
4969
4970 static int ext4_sync_fs(struct super_block *sb, int wait)
4971 {
4972         int ret = 0;
4973         tid_t target;
4974         bool needs_barrier = false;
4975         struct ext4_sb_info *sbi = EXT4_SB(sb);
4976
4977         if (unlikely(ext4_forced_shutdown(sbi)))
4978                 return 0;
4979
4980         trace_ext4_sync_fs(sb, wait);
4981         flush_workqueue(sbi->rsv_conversion_wq);
4982         /*
4983          * Writeback quota in non-journalled quota case - journalled quota has
4984          * no dirty dquots
4985          */
4986         dquot_writeback_dquots(sb, -1);
4987         /*
4988          * Data writeback is possible w/o journal transaction, so barrier must
4989          * being sent at the end of the function. But we can skip it if
4990          * transaction_commit will do it for us.
4991          */
4992         if (sbi->s_journal) {
4993                 target = jbd2_get_latest_transaction(sbi->s_journal);
4994                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4995                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4996                         needs_barrier = true;
4997
4998                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4999                         if (wait)
5000                                 ret = jbd2_log_wait_commit(sbi->s_journal,
5001                                                            target);
5002                 }
5003         } else if (wait && test_opt(sb, BARRIER))
5004                 needs_barrier = true;
5005         if (needs_barrier) {
5006                 int err;
5007                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5008                 if (!ret)
5009                         ret = err;
5010         }
5011
5012         return ret;
5013 }
5014
5015 /*
5016  * LVM calls this function before a (read-only) snapshot is created.  This
5017  * gives us a chance to flush the journal completely and mark the fs clean.
5018  *
5019  * Note that only this function cannot bring a filesystem to be in a clean
5020  * state independently. It relies on upper layer to stop all data & metadata
5021  * modifications.
5022  */
5023 static int ext4_freeze(struct super_block *sb)
5024 {
5025         int error = 0;
5026         journal_t *journal;
5027
5028         if (sb_rdonly(sb))
5029                 return 0;
5030
5031         journal = EXT4_SB(sb)->s_journal;
5032
5033         if (journal) {
5034                 /* Now we set up the journal barrier. */
5035                 jbd2_journal_lock_updates(journal);
5036
5037                 /*
5038                  * Don't clear the needs_recovery flag if we failed to
5039                  * flush the journal.
5040                  */
5041                 error = jbd2_journal_flush(journal);
5042                 if (error < 0)
5043                         goto out;
5044
5045                 /* Journal blocked and flushed, clear needs_recovery flag. */
5046                 ext4_clear_feature_journal_needs_recovery(sb);
5047         }
5048
5049         error = ext4_commit_super(sb, 1);
5050 out:
5051         if (journal)
5052                 /* we rely on upper layer to stop further updates */
5053                 jbd2_journal_unlock_updates(journal);
5054         return error;
5055 }
5056
5057 /*
5058  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5059  * flag here, even though the filesystem is not technically dirty yet.
5060  */
5061 static int ext4_unfreeze(struct super_block *sb)
5062 {
5063         if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5064                 return 0;
5065
5066         if (EXT4_SB(sb)->s_journal) {
5067                 /* Reset the needs_recovery flag before the fs is unlocked. */
5068                 ext4_set_feature_journal_needs_recovery(sb);
5069         }
5070
5071         ext4_commit_super(sb, 1);
5072         return 0;
5073 }
5074
5075 /*
5076  * Structure to save mount options for ext4_remount's benefit
5077  */
5078 struct ext4_mount_options {
5079         unsigned long s_mount_opt;
5080         unsigned long s_mount_opt2;
5081         kuid_t s_resuid;
5082         kgid_t s_resgid;
5083         unsigned long s_commit_interval;
5084         u32 s_min_batch_time, s_max_batch_time;
5085 #ifdef CONFIG_QUOTA
5086         int s_jquota_fmt;
5087         char *s_qf_names[EXT4_MAXQUOTAS];
5088 #endif
5089 };
5090
5091 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5092 {
5093         struct ext4_super_block *es;
5094         struct ext4_sb_info *sbi = EXT4_SB(sb);
5095         unsigned long old_sb_flags;
5096         struct ext4_mount_options old_opts;
5097         int enable_quota = 0;
5098         ext4_group_t g;
5099         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5100         int err = 0;
5101 #ifdef CONFIG_QUOTA
5102         int i, j;
5103 #endif
5104         char *orig_data = kstrdup(data, GFP_KERNEL);
5105
5106         if (data && !orig_data)
5107                 return -ENOMEM;
5108
5109         /* Store the original options */
5110         old_sb_flags = sb->s_flags;
5111         old_opts.s_mount_opt = sbi->s_mount_opt;
5112         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5113         old_opts.s_resuid = sbi->s_resuid;
5114         old_opts.s_resgid = sbi->s_resgid;
5115         old_opts.s_commit_interval = sbi->s_commit_interval;
5116         old_opts.s_min_batch_time = sbi->s_min_batch_time;
5117         old_opts.s_max_batch_time = sbi->s_max_batch_time;
5118 #ifdef CONFIG_QUOTA
5119         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5120         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5121                 if (sbi->s_qf_names[i]) {
5122                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
5123                                                          GFP_KERNEL);
5124                         if (!old_opts.s_qf_names[i]) {
5125                                 for (j = 0; j < i; j++)
5126                                         kfree(old_opts.s_qf_names[j]);
5127                                 kfree(orig_data);
5128                                 return -ENOMEM;
5129                         }
5130                 } else
5131                         old_opts.s_qf_names[i] = NULL;
5132 #endif
5133         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5134                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5135
5136         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5137                 err = -EINVAL;
5138                 goto restore_opts;
5139         }
5140
5141         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5142             test_opt(sb, JOURNAL_CHECKSUM)) {
5143                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5144                          "during remount not supported; ignoring");
5145                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5146         }
5147
5148         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5149                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5150                         ext4_msg(sb, KERN_ERR, "can't mount with "
5151                                  "both data=journal and delalloc");
5152                         err = -EINVAL;
5153                         goto restore_opts;
5154                 }
5155                 if (test_opt(sb, DIOREAD_NOLOCK)) {
5156                         ext4_msg(sb, KERN_ERR, "can't mount with "
5157                                  "both data=journal and dioread_nolock");
5158                         err = -EINVAL;
5159                         goto restore_opts;
5160                 }
5161                 if (test_opt(sb, DAX)) {
5162                         ext4_msg(sb, KERN_ERR, "can't mount with "
5163                                  "both data=journal and dax");
5164                         err = -EINVAL;
5165                         goto restore_opts;
5166                 }
5167         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5168                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5169                         ext4_msg(sb, KERN_ERR, "can't mount with "
5170                                 "journal_async_commit in data=ordered mode");
5171                         err = -EINVAL;
5172                         goto restore_opts;
5173                 }
5174         }
5175
5176         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5177                 ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5178                 err = -EINVAL;
5179                 goto restore_opts;
5180         }
5181
5182         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5183                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5184                         "dax flag with busy inodes while remounting");
5185                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5186         }
5187
5188         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5189                 ext4_abort(sb, "Abort forced by user");
5190
5191         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5192                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5193
5194         es = sbi->s_es;
5195
5196         if (sbi->s_journal) {
5197                 ext4_init_journal_params(sb, sbi->s_journal);
5198                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5199         }
5200
5201         if (*flags & SB_LAZYTIME)
5202                 sb->s_flags |= SB_LAZYTIME;
5203
5204         if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5205                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5206                         err = -EROFS;
5207                         goto restore_opts;
5208                 }
5209
5210                 if (*flags & SB_RDONLY) {
5211                         err = sync_filesystem(sb);
5212                         if (err < 0)
5213                                 goto restore_opts;
5214                         err = dquot_suspend(sb, -1);
5215                         if (err < 0)
5216                                 goto restore_opts;
5217
5218                         /*
5219                          * First of all, the unconditional stuff we have to do
5220                          * to disable replay of the journal when we next remount
5221                          */
5222                         sb->s_flags |= SB_RDONLY;
5223
5224                         /*
5225                          * OK, test if we are remounting a valid rw partition
5226                          * readonly, and if so set the rdonly flag and then
5227                          * mark the partition as valid again.
5228                          */
5229                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5230                             (sbi->s_mount_state & EXT4_VALID_FS))
5231                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
5232
5233                         if (sbi->s_journal)
5234                                 ext4_mark_recovery_complete(sb, es);
5235                         if (sbi->s_mmp_tsk)
5236                                 kthread_stop(sbi->s_mmp_tsk);
5237                 } else {
5238                         /* Make sure we can mount this feature set readwrite */
5239                         if (ext4_has_feature_readonly(sb) ||
5240                             !ext4_feature_set_ok(sb, 0)) {
5241                                 err = -EROFS;
5242                                 goto restore_opts;
5243                         }
5244                         /*
5245                          * Make sure the group descriptor checksums
5246                          * are sane.  If they aren't, refuse to remount r/w.
5247                          */
5248                         for (g = 0; g < sbi->s_groups_count; g++) {
5249                                 struct ext4_group_desc *gdp =
5250                                         ext4_get_group_desc(sb, g, NULL);
5251
5252                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5253                                         ext4_msg(sb, KERN_ERR,
5254                "ext4_remount: Checksum for group %u failed (%u!=%u)",
5255                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5256                                                le16_to_cpu(gdp->bg_checksum));
5257                                         err = -EFSBADCRC;
5258                                         goto restore_opts;
5259                                 }
5260                         }
5261
5262                         /*
5263                          * If we have an unprocessed orphan list hanging
5264                          * around from a previously readonly bdev mount,
5265                          * require a full umount/remount for now.
5266                          */
5267                         if (es->s_last_orphan) {
5268                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5269                                        "remount RDWR because of unprocessed "
5270                                        "orphan inode list.  Please "
5271                                        "umount/remount instead");
5272                                 err = -EINVAL;
5273                                 goto restore_opts;
5274                         }
5275
5276                         /*
5277                          * Mounting a RDONLY partition read-write, so reread
5278                          * and store the current valid flag.  (It may have
5279                          * been changed by e2fsck since we originally mounted
5280                          * the partition.)
5281                          */
5282                         if (sbi->s_journal)
5283                                 ext4_clear_journal_err(sb, es);
5284                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5285
5286                         err = ext4_setup_super(sb, es, 0);
5287                         if (err)
5288                                 goto restore_opts;
5289
5290                         sb->s_flags &= ~SB_RDONLY;
5291                         if (ext4_has_feature_mmp(sb))
5292                                 if (ext4_multi_mount_protect(sb,
5293                                                 le64_to_cpu(es->s_mmp_block))) {
5294                                         err = -EROFS;
5295                                         goto restore_opts;
5296                                 }
5297                         enable_quota = 1;
5298                 }
5299         }
5300
5301         /*
5302          * Reinitialize lazy itable initialization thread based on
5303          * current settings
5304          */
5305         if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5306                 ext4_unregister_li_request(sb);
5307         else {
5308                 ext4_group_t first_not_zeroed;
5309                 first_not_zeroed = ext4_has_uninit_itable(sb);
5310                 ext4_register_li_request(sb, first_not_zeroed);
5311         }
5312
5313         ext4_setup_system_zone(sb);
5314         if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5315                 err = ext4_commit_super(sb, 1);
5316                 if (err)
5317                         goto restore_opts;
5318         }
5319
5320 #ifdef CONFIG_QUOTA
5321         /* Release old quota file names */
5322         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5323                 kfree(old_opts.s_qf_names[i]);
5324         if (enable_quota) {
5325                 if (sb_any_quota_suspended(sb))
5326                         dquot_resume(sb, -1);
5327                 else if (ext4_has_feature_quota(sb)) {
5328                         err = ext4_enable_quotas(sb);
5329                         if (err)
5330                                 goto restore_opts;
5331                 }
5332         }
5333 #endif
5334
5335         *flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5336         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5337         kfree(orig_data);
5338         return 0;
5339
5340 restore_opts:
5341         sb->s_flags = old_sb_flags;
5342         sbi->s_mount_opt = old_opts.s_mount_opt;
5343         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5344         sbi->s_resuid = old_opts.s_resuid;
5345         sbi->s_resgid = old_opts.s_resgid;
5346         sbi->s_commit_interval = old_opts.s_commit_interval;
5347         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5348         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5349 #ifdef CONFIG_QUOTA
5350         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5351         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5352                 kfree(sbi->s_qf_names[i]);
5353                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5354         }
5355 #endif
5356         kfree(orig_data);
5357         return err;
5358 }
5359
5360 #ifdef CONFIG_QUOTA
5361 static int ext4_statfs_project(struct super_block *sb,
5362                                kprojid_t projid, struct kstatfs *buf)
5363 {
5364         struct kqid qid;
5365         struct dquot *dquot;
5366         u64 limit;
5367         u64 curblock;
5368
5369         qid = make_kqid_projid(projid);
5370         dquot = dqget(sb, qid);
5371         if (IS_ERR(dquot))
5372                 return PTR_ERR(dquot);
5373         spin_lock(&dquot->dq_dqb_lock);
5374
5375         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5376                  dquot->dq_dqb.dqb_bsoftlimit :
5377                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5378         if (limit && buf->f_blocks > limit) {
5379                 curblock = (dquot->dq_dqb.dqb_curspace +
5380                             dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5381                 buf->f_blocks = limit;
5382                 buf->f_bfree = buf->f_bavail =
5383                         (buf->f_blocks > curblock) ?
5384                          (buf->f_blocks - curblock) : 0;
5385         }
5386
5387         limit = dquot->dq_dqb.dqb_isoftlimit ?
5388                 dquot->dq_dqb.dqb_isoftlimit :
5389                 dquot->dq_dqb.dqb_ihardlimit;
5390         if (limit && buf->f_files > limit) {
5391                 buf->f_files = limit;
5392                 buf->f_ffree =
5393                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5394                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5395         }
5396
5397         spin_unlock(&dquot->dq_dqb_lock);
5398         dqput(dquot);
5399         return 0;
5400 }
5401 #endif
5402
5403 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5404 {
5405         struct super_block *sb = dentry->d_sb;
5406         struct ext4_sb_info *sbi = EXT4_SB(sb);
5407         struct ext4_super_block *es = sbi->s_es;
5408         ext4_fsblk_t overhead = 0, resv_blocks;
5409         u64 fsid;
5410         s64 bfree;
5411         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5412
5413         if (!test_opt(sb, MINIX_DF))
5414                 overhead = sbi->s_overhead;
5415
5416         buf->f_type = EXT4_SUPER_MAGIC;
5417         buf->f_bsize = sb->s_blocksize;
5418         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5419         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5420                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5421         /* prevent underflow in case that few free space is available */
5422         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5423         buf->f_bavail = buf->f_bfree -
5424                         (ext4_r_blocks_count(es) + resv_blocks);
5425         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5426                 buf->f_bavail = 0;
5427         buf->f_files = le32_to_cpu(es->s_inodes_count);
5428         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5429         buf->f_namelen = EXT4_NAME_LEN;
5430         fsid = le64_to_cpup((void *)es->s_uuid) ^
5431                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5432         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5433         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5434
5435 #ifdef CONFIG_QUOTA
5436         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5437             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5438                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5439 #endif
5440         return 0;
5441 }
5442
5443
5444 #ifdef CONFIG_QUOTA
5445
5446 /*
5447  * Helper functions so that transaction is started before we acquire dqio_sem
5448  * to keep correct lock ordering of transaction > dqio_sem
5449  */
5450 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5451 {
5452         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5453 }
5454
5455 static int ext4_write_dquot(struct dquot *dquot)
5456 {
5457         int ret, err;
5458         handle_t *handle;
5459         struct inode *inode;
5460
5461         inode = dquot_to_inode(dquot);
5462         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5463                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5464         if (IS_ERR(handle))
5465                 return PTR_ERR(handle);
5466         ret = dquot_commit(dquot);
5467         err = ext4_journal_stop(handle);
5468         if (!ret)
5469                 ret = err;
5470         return ret;
5471 }
5472
5473 static int ext4_acquire_dquot(struct dquot *dquot)
5474 {
5475         int ret, err;
5476         handle_t *handle;
5477
5478         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5479                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5480         if (IS_ERR(handle))
5481                 return PTR_ERR(handle);
5482         ret = dquot_acquire(dquot);
5483         err = ext4_journal_stop(handle);
5484         if (!ret)
5485                 ret = err;
5486         return ret;
5487 }
5488
5489 static int ext4_release_dquot(struct dquot *dquot)
5490 {
5491         int ret, err;
5492         handle_t *handle;
5493
5494         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5495                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5496         if (IS_ERR(handle)) {
5497                 /* Release dquot anyway to avoid endless cycle in dqput() */
5498                 dquot_release(dquot);
5499                 return PTR_ERR(handle);
5500         }
5501         ret = dquot_release(dquot);
5502         err = ext4_journal_stop(handle);
5503         if (!ret)
5504                 ret = err;
5505         return ret;
5506 }
5507
5508 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5509 {
5510         struct super_block *sb = dquot->dq_sb;
5511         struct ext4_sb_info *sbi = EXT4_SB(sb);
5512
5513         /* Are we journaling quotas? */
5514         if (ext4_has_feature_quota(sb) ||
5515             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5516                 dquot_mark_dquot_dirty(dquot);
5517                 return ext4_write_dquot(dquot);
5518         } else {
5519                 return dquot_mark_dquot_dirty(dquot);
5520         }
5521 }
5522
5523 static int ext4_write_info(struct super_block *sb, int type)
5524 {
5525         int ret, err;
5526         handle_t *handle;
5527
5528         /* Data block + inode block */
5529         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5530         if (IS_ERR(handle))
5531                 return PTR_ERR(handle);
5532         ret = dquot_commit_info(sb, type);
5533         err = ext4_journal_stop(handle);
5534         if (!ret)
5535                 ret = err;
5536         return ret;
5537 }
5538
5539 /*
5540  * Turn on quotas during mount time - we need to find
5541  * the quota file and such...
5542  */
5543 static int ext4_quota_on_mount(struct super_block *sb, int type)
5544 {
5545         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5546                                         EXT4_SB(sb)->s_jquota_fmt, type);
5547 }
5548
5549 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5550 {
5551         struct ext4_inode_info *ei = EXT4_I(inode);
5552
5553         /* The first argument of lockdep_set_subclass has to be
5554          * *exactly* the same as the argument to init_rwsem() --- in
5555          * this case, in init_once() --- or lockdep gets unhappy
5556          * because the name of the lock is set using the
5557          * stringification of the argument to init_rwsem().
5558          */
5559         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5560         lockdep_set_subclass(&ei->i_data_sem, subclass);
5561 }
5562
5563 /*
5564  * Standard function to be called on quota_on
5565  */
5566 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5567                          const struct path *path)
5568 {
5569         int err;
5570
5571         if (!test_opt(sb, QUOTA))
5572                 return -EINVAL;
5573
5574         /* Quotafile not on the same filesystem? */
5575         if (path->dentry->d_sb != sb)
5576                 return -EXDEV;
5577         /* Journaling quota? */
5578         if (EXT4_SB(sb)->s_qf_names[type]) {
5579                 /* Quotafile not in fs root? */
5580                 if (path->dentry->d_parent != sb->s_root)
5581                         ext4_msg(sb, KERN_WARNING,
5582                                 "Quota file not on filesystem root. "
5583                                 "Journaled quota will not work");
5584                 sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5585         } else {
5586                 /*
5587                  * Clear the flag just in case mount options changed since
5588                  * last time.
5589                  */
5590                 sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5591         }
5592
5593         /*
5594          * When we journal data on quota file, we have to flush journal to see
5595          * all updates to the file when we bypass pagecache...
5596          */
5597         if (EXT4_SB(sb)->s_journal &&
5598             ext4_should_journal_data(d_inode(path->dentry))) {
5599                 /*
5600                  * We don't need to lock updates but journal_flush() could
5601                  * otherwise be livelocked...
5602                  */
5603                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5604                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5605                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5606                 if (err)
5607                         return err;
5608         }
5609
5610         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5611         err = dquot_quota_on(sb, type, format_id, path);
5612         if (err) {
5613                 lockdep_set_quota_inode(path->dentry->d_inode,
5614                                              I_DATA_SEM_NORMAL);
5615         } else {
5616                 struct inode *inode = d_inode(path->dentry);
5617                 handle_t *handle;
5618
5619                 /*
5620                  * Set inode flags to prevent userspace from messing with quota
5621                  * files. If this fails, we return success anyway since quotas
5622                  * are already enabled and this is not a hard failure.
5623                  */
5624                 inode_lock(inode);
5625                 handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5626                 if (IS_ERR(handle))
5627                         goto unlock_inode;
5628                 EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5629                 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5630                                 S_NOATIME | S_IMMUTABLE);
5631                 ext4_mark_inode_dirty(handle, inode);
5632                 ext4_journal_stop(handle);
5633         unlock_inode:
5634                 inode_unlock(inode);
5635         }
5636         return err;
5637 }
5638
5639 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5640                              unsigned int flags)
5641 {
5642         int err;
5643         struct inode *qf_inode;
5644         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5645                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5646                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5647                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5648         };
5649
5650         BUG_ON(!ext4_has_feature_quota(sb));
5651
5652         if (!qf_inums[type])
5653                 return -EPERM;
5654
5655         qf_inode = ext4_iget(sb, qf_inums[type]);
5656         if (IS_ERR(qf_inode)) {
5657                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5658                 return PTR_ERR(qf_inode);
5659         }
5660
5661         /* Don't account quota for quota files to avoid recursion */
5662         qf_inode->i_flags |= S_NOQUOTA;
5663         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5664         err = dquot_enable(qf_inode, type, format_id, flags);
5665         iput(qf_inode);
5666         if (err)
5667                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5668
5669         return err;
5670 }
5671
5672 /* Enable usage tracking for all quota types. */
5673 static int ext4_enable_quotas(struct super_block *sb)
5674 {
5675         int type, err = 0;
5676         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5677                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5678                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5679                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5680         };
5681         bool quota_mopt[EXT4_MAXQUOTAS] = {
5682                 test_opt(sb, USRQUOTA),
5683                 test_opt(sb, GRPQUOTA),
5684                 test_opt(sb, PRJQUOTA),
5685         };
5686
5687         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5688         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5689                 if (qf_inums[type]) {
5690                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5691                                 DQUOT_USAGE_ENABLED |
5692                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5693                         if (err) {
5694                                 ext4_warning(sb,
5695                                         "Failed to enable quota tracking "
5696                                         "(type=%d, err=%d). Please run "
5697                                         "e2fsck to fix.", type, err);
5698                                 for (type--; type >= 0; type--)
5699                                         dquot_quota_off(sb, type);
5700
5701                                 return err;
5702                         }
5703                 }
5704         }
5705         return 0;
5706 }
5707
5708 static int ext4_quota_off(struct super_block *sb, int type)
5709 {
5710         struct inode *inode = sb_dqopt(sb)->files[type];
5711         handle_t *handle;
5712         int err;
5713
5714         /* Force all delayed allocation blocks to be allocated.
5715          * Caller already holds s_umount sem */
5716         if (test_opt(sb, DELALLOC))
5717                 sync_filesystem(sb);
5718
5719         if (!inode || !igrab(inode))
5720                 goto out;
5721
5722         err = dquot_quota_off(sb, type);
5723         if (err || ext4_has_feature_quota(sb))
5724                 goto out_put;
5725
5726         inode_lock(inode);
5727         /*
5728          * Update modification times of quota files when userspace can
5729          * start looking at them. If we fail, we return success anyway since
5730          * this is not a hard failure and quotas are already disabled.
5731          */
5732         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5733         if (IS_ERR(handle))
5734                 goto out_unlock;
5735         EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5736         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5737         inode->i_mtime = inode->i_ctime = current_time(inode);
5738         ext4_mark_inode_dirty(handle, inode);
5739         ext4_journal_stop(handle);
5740 out_unlock:
5741         inode_unlock(inode);
5742 out_put:
5743         lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5744         iput(inode);
5745         return err;
5746 out:
5747         return dquot_quota_off(sb, type);
5748 }
5749
5750 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5751  * acquiring the locks... As quota files are never truncated and quota code
5752  * itself serializes the operations (and no one else should touch the files)
5753  * we don't have to be afraid of races */
5754 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5755                                size_t len, loff_t off)
5756 {
5757         struct inode *inode = sb_dqopt(sb)->files[type];
5758         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5759         int offset = off & (sb->s_blocksize - 1);
5760         int tocopy;
5761         size_t toread;
5762         struct buffer_head *bh;
5763         loff_t i_size = i_size_read(inode);
5764
5765         if (off > i_size)
5766                 return 0;
5767         if (off+len > i_size)
5768                 len = i_size-off;
5769         toread = len;
5770         while (toread > 0) {
5771                 tocopy = sb->s_blocksize - offset < toread ?
5772                                 sb->s_blocksize - offset : toread;
5773                 bh = ext4_bread(NULL, inode, blk, 0);
5774                 if (IS_ERR(bh))
5775                         return PTR_ERR(bh);
5776                 if (!bh)        /* A hole? */
5777                         memset(data, 0, tocopy);
5778                 else
5779                         memcpy(data, bh->b_data+offset, tocopy);
5780                 brelse(bh);
5781                 offset = 0;
5782                 toread -= tocopy;
5783                 data += tocopy;
5784                 blk++;
5785         }
5786         return len;
5787 }
5788
5789 /* Write to quotafile (we know the transaction is already started and has
5790  * enough credits) */
5791 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5792                                 const char *data, size_t len, loff_t off)
5793 {
5794         struct inode *inode = sb_dqopt(sb)->files[type];
5795         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5796         int err, offset = off & (sb->s_blocksize - 1);
5797         int retries = 0;
5798         struct buffer_head *bh;
5799         handle_t *handle = journal_current_handle();
5800
5801         if (EXT4_SB(sb)->s_journal && !handle) {
5802                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5803                         " cancelled because transaction is not started",
5804                         (unsigned long long)off, (unsigned long long)len);
5805                 return -EIO;
5806         }
5807         /*
5808          * Since we account only one data block in transaction credits,
5809          * then it is impossible to cross a block boundary.
5810          */
5811         if (sb->s_blocksize - offset < len) {
5812                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5813                         " cancelled because not block aligned",
5814                         (unsigned long long)off, (unsigned long long)len);
5815                 return -EIO;
5816         }
5817
5818         do {
5819                 bh = ext4_bread(handle, inode, blk,
5820                                 EXT4_GET_BLOCKS_CREATE |
5821                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5822         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5823                  ext4_should_retry_alloc(inode->i_sb, &retries));
5824         if (IS_ERR(bh))
5825                 return PTR_ERR(bh);
5826         if (!bh)
5827                 goto out;
5828         BUFFER_TRACE(bh, "get write access");
5829         err = ext4_journal_get_write_access(handle, bh);
5830         if (err) {
5831                 brelse(bh);
5832                 return err;
5833         }
5834         lock_buffer(bh);
5835         memcpy(bh->b_data+offset, data, len);
5836         flush_dcache_page(bh->b_page);
5837         unlock_buffer(bh);
5838         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5839         brelse(bh);
5840 out:
5841         if (inode->i_size < off + len) {
5842                 i_size_write(inode, off + len);
5843                 EXT4_I(inode)->i_disksize = inode->i_size;
5844                 ext4_mark_inode_dirty(handle, inode);
5845         }
5846         return len;
5847 }
5848
5849 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5850 {
5851         const struct quota_format_ops   *ops;
5852
5853         if (!sb_has_quota_loaded(sb, qid->type))
5854                 return -ESRCH;
5855         ops = sb_dqopt(sb)->ops[qid->type];
5856         if (!ops || !ops->get_next_id)
5857                 return -ENOSYS;
5858         return dquot_get_next_id(sb, qid);
5859 }
5860 #endif
5861
5862 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5863                        const char *dev_name, void *data)
5864 {
5865         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5866 }
5867
5868 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5869 static inline void register_as_ext2(void)
5870 {
5871         int err = register_filesystem(&ext2_fs_type);
5872         if (err)
5873                 printk(KERN_WARNING
5874                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5875 }
5876
5877 static inline void unregister_as_ext2(void)
5878 {
5879         unregister_filesystem(&ext2_fs_type);
5880 }
5881
5882 static inline int ext2_feature_set_ok(struct super_block *sb)
5883 {
5884         if (ext4_has_unknown_ext2_incompat_features(sb))
5885                 return 0;
5886         if (sb_rdonly(sb))
5887                 return 1;
5888         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5889                 return 0;
5890         return 1;
5891 }
5892 #else
5893 static inline void register_as_ext2(void) { }
5894 static inline void unregister_as_ext2(void) { }
5895 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5896 #endif
5897
5898 static inline void register_as_ext3(void)
5899 {
5900         int err = register_filesystem(&ext3_fs_type);
5901         if (err)
5902                 printk(KERN_WARNING
5903                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5904 }
5905
5906 static inline void unregister_as_ext3(void)
5907 {
5908         unregister_filesystem(&ext3_fs_type);
5909 }
5910
5911 static inline int ext3_feature_set_ok(struct super_block *sb)
5912 {
5913         if (ext4_has_unknown_ext3_incompat_features(sb))
5914                 return 0;
5915         if (!ext4_has_feature_journal(sb))
5916                 return 0;
5917         if (sb_rdonly(sb))
5918                 return 1;
5919         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5920                 return 0;
5921         return 1;
5922 }
5923
5924 static struct file_system_type ext4_fs_type = {
5925         .owner          = THIS_MODULE,
5926         .name           = "ext4",
5927         .mount          = ext4_mount,
5928         .kill_sb        = kill_block_super,
5929         .fs_flags       = FS_REQUIRES_DEV,
5930 };
5931 MODULE_ALIAS_FS("ext4");
5932
5933 /* Shared across all ext4 file systems */
5934 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5935
5936 static int __init ext4_init_fs(void)
5937 {
5938         int i, err;
5939
5940         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5941         ext4_li_info = NULL;
5942         mutex_init(&ext4_li_mtx);
5943
5944         /* Build-time check for flags consistency */
5945         ext4_check_flag_values();
5946
5947         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5948                 init_waitqueue_head(&ext4__ioend_wq[i]);
5949
5950         err = ext4_init_es();
5951         if (err)
5952                 return err;
5953
5954         err = ext4_init_pageio();
5955         if (err)
5956                 goto out5;
5957
5958         err = ext4_init_system_zone();
5959         if (err)
5960                 goto out4;
5961
5962         err = ext4_init_sysfs();
5963         if (err)
5964                 goto out3;
5965
5966         err = ext4_init_mballoc();
5967         if (err)
5968                 goto out2;
5969         err = init_inodecache();
5970         if (err)
5971                 goto out1;
5972         register_as_ext3();
5973         register_as_ext2();
5974         err = register_filesystem(&ext4_fs_type);
5975         if (err)
5976                 goto out;
5977
5978         return 0;
5979 out:
5980         unregister_as_ext2();
5981         unregister_as_ext3();
5982         destroy_inodecache();
5983 out1:
5984         ext4_exit_mballoc();
5985 out2:
5986         ext4_exit_sysfs();
5987 out3:
5988         ext4_exit_system_zone();
5989 out4:
5990         ext4_exit_pageio();
5991 out5:
5992         ext4_exit_es();
5993
5994         return err;
5995 }
5996
5997 static void __exit ext4_exit_fs(void)
5998 {
5999         ext4_destroy_lazyinit_thread();
6000         unregister_as_ext2();
6001         unregister_as_ext3();
6002         unregister_filesystem(&ext4_fs_type);
6003         destroy_inodecache();
6004         ext4_exit_mballoc();
6005         ext4_exit_sysfs();
6006         ext4_exit_system_zone();
6007         ext4_exit_pageio();
6008         ext4_exit_es();
6009 }
6010
6011 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6012 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6013 MODULE_LICENSE("GPL");
6014 MODULE_SOFTDEP("pre: crc32c");
6015 module_init(ext4_init_fs)
6016 module_exit(ext4_exit_fs)