fs/ext4/namei.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/ext4/namei.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/namei.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  *  Directory entry file type support and forward compatibility hooks
  19  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  20  *  Hash Tree Directory indexing (c)
  21  *      Daniel Phillips, 2001
  22  *  Hash Tree Directory indexing porting
  23  *      Christopher Li, 2002
  24  *  Hash Tree Directory indexing cleanup
  25  *      Theodore Ts'o, 2002
  26  */
  27
  28 #include <linux/fs.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/time.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/stat.h>
  33 #include <linux/string.h>
  34 #include <linux/quotaops.h>
  35 #include <linux/buffer_head.h>
  36 #include <linux/bio.h>
  37 #include <linux/iversion.h>
  38 #include <linux/unicode.h>
  39 #include "ext4.h"
  40 #include "ext4_jbd2.h"
  41
  42 #include "xattr.h"
  43 #include "acl.h"
  44
  45 #include <trace/events/ext4.h>
  46 /*
  47  * define how far ahead to read directories while searching them.
  48  */
  49 #define NAMEI_RA_CHUNKS  2
  50 #define NAMEI_RA_BLOCKS  4
  51 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  52
  53 static struct buffer_head *ext4_append(handle_t *handle,
  54                                         struct inode *inode,
  55                                         ext4_lblk_t *block)
  56 {
  57         struct buffer_head *bh;
  58         int err;
  59
  60         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  61                      ((inode->i_size >> 10) >=
  62                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
  63                 return ERR_PTR(-ENOSPC);
  64
  65         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  66
  67         bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
  68         if (IS_ERR(bh))
  69                 return bh;
  70         inode->i_size += inode->i_sb->s_blocksize;
  71         EXT4_I(inode)->i_disksize = inode->i_size;
  72         BUFFER_TRACE(bh, "get_write_access");
  73         err = ext4_journal_get_write_access(handle, bh);
  74         if (err) {
  75                 brelse(bh);
  76                 ext4_std_error(inode->i_sb, err);
  77                 return ERR_PTR(err);
  78         }
  79         return bh;
  80 }
  81
  82 static int ext4_dx_csum_verify(struct inode *inode,
  83                                struct ext4_dir_entry *dirent);
  84
  85 typedef enum {
  86         EITHER, INDEX, DIRENT
  87 } dirblock_type_t;
  88
  89 #define ext4_read_dirblock(inode, block, type) \
  90         __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
  91
  92 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
  93                                                 ext4_lblk_t block,
  94                                                 dirblock_type_t type,
  95                                                 const char *func,
  96                                                 unsigned int line)
  97 {
  98         struct buffer_head *bh;
  99         struct ext4_dir_entry *dirent;
 100         int is_dx_block = 0;
 101
 102         bh = ext4_bread(NULL, inode, block, 0);
 103         if (IS_ERR(bh)) {
 104                 __ext4_warning(inode->i_sb, func, line,
 105                                "inode #%lu: lblock %lu: comm %s: "
 106                                "error %ld reading directory block",
 107                                inode->i_ino, (unsigned long)block,
 108                                current->comm, PTR_ERR(bh));
 109
 110                 return bh;
 111         }
 112         if (!bh) {
 113                 ext4_error_inode(inode, func, line, block,
 114                                  "Directory hole found");
 115                 return ERR_PTR(-EFSCORRUPTED);
 116         }
 117         dirent = (struct ext4_dir_entry *) bh->b_data;
 118         /* Determine whether or not we have an index block */
 119         if (is_dx(inode)) {
 120                 if (block == 0)
 121                         is_dx_block = 1;
 122                 else if (ext4_rec_len_from_disk(dirent->rec_len,
 123                                                 inode->i_sb->s_blocksize) ==
 124                          inode->i_sb->s_blocksize)
 125                         is_dx_block = 1;
 126         }
 127         if (!is_dx_block && type == INDEX) {
 128                 ext4_error_inode(inode, func, line, block,
 129                        "directory leaf block found instead of index block");
 130                 brelse(bh);
 131                 return ERR_PTR(-EFSCORRUPTED);
 132         }
 133         if (!ext4_has_metadata_csum(inode->i_sb) ||
 134             buffer_verified(bh))
 135                 return bh;
 136
 137         /*
 138          * An empty leaf block can get mistaken for a index block; for
 139          * this reason, we can only check the index checksum when the
 140          * caller is sure it should be an index block.
 141          */
 142         if (is_dx_block && type == INDEX) {
 143                 if (ext4_dx_csum_verify(inode, dirent))
 144                         set_buffer_verified(bh);
 145                 else {
 146                         ext4_error_inode(inode, func, line, block,
 147                                          "Directory index failed checksum");
 148                         brelse(bh);
 149                         return ERR_PTR(-EFSBADCRC);
 150                 }
 151         }
 152         if (!is_dx_block) {
 153                 if (ext4_dirent_csum_verify(inode, dirent))
 154                         set_buffer_verified(bh);
 155                 else {
 156                         ext4_error_inode(inode, func, line, block,
 157                                          "Directory block failed checksum");
 158                         brelse(bh);
 159                         return ERR_PTR(-EFSBADCRC);
 160                 }
 161         }
 162         return bh;
 163 }
 164
 165 #ifndef assert
 166 #define assert(test) J_ASSERT(test)
 167 #endif
 168
 169 #ifdef DX_DEBUG
 170 #define dxtrace(command) command
 171 #else
 172 #define dxtrace(command)
 173 #endif
 174
 175 struct fake_dirent
 176 {
 177         __le32 inode;
 178         __le16 rec_len;
 179         u8 name_len;
 180         u8 file_type;
 181 };
 182
 183 struct dx_countlimit
 184 {
 185         __le16 limit;
 186         __le16 count;
 187 };
 188
 189 struct dx_entry
 190 {
 191         __le32 hash;
 192         __le32 block;
 193 };
 194
 195 /*
 196  * dx_root_info is laid out so that if it should somehow get overlaid by a
 197  * dirent the two low bits of the hash version will be zero.  Therefore, the
 198  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 199  */
 200
 201 struct dx_root
 202 {
 203         struct fake_dirent dot;
 204         char dot_name[4];
 205         struct fake_dirent dotdot;
 206         char dotdot_name[4];
 207         struct dx_root_info
 208         {
 209                 __le32 reserved_zero;
 210                 u8 hash_version;
 211                 u8 info_length; /* 8 */
 212                 u8 indirect_levels;
 213                 u8 unused_flags;
 214         }
 215         info;
 216         struct dx_entry entries[0];
 217 };
 218
 219 struct dx_node
 220 {
 221         struct fake_dirent fake;
 222         struct dx_entry entries[0];
 223 };
 224
 225
 226 struct dx_frame
 227 {
 228         struct buffer_head *bh;
 229         struct dx_entry *entries;
 230         struct dx_entry *at;
 231 };
 232
 233 struct dx_map_entry
 234 {
 235         u32 hash;
 236         u16 offs;
 237         u16 size;
 238 };
 239
 240 /*
 241  * This goes at the end of each htree block.
 242  */
 243 struct dx_tail {
 244         u32 dt_reserved;
 245         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 246 };
 247
 248 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 249 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 250 static inline unsigned dx_get_hash(struct dx_entry *entry);
 251 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 252 static unsigned dx_get_count(struct dx_entry *entries);
 253 static unsigned dx_get_limit(struct dx_entry *entries);
 254 static void dx_set_count(struct dx_entry *entries, unsigned value);
 255 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 256 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 257 static unsigned dx_node_limit(struct inode *dir);
 258 static struct dx_frame *dx_probe(struct ext4_filename *fname,
 259                                  struct inode *dir,
 260                                  struct dx_hash_info *hinfo,
 261                                  struct dx_frame *frame);
 262 static void dx_release(struct dx_frame *frames);
 263 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 264                        unsigned blocksize, struct dx_hash_info *hinfo,
 265                        struct dx_map_entry map[]);
 266 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 267 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 268                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 269 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 270 static void dx_insert_block(struct dx_frame *frame,
 271                                         u32 hash, ext4_lblk_t block);
 272 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 273                                  struct dx_frame *frame,
 274                                  struct dx_frame *frames,
 275                                  __u32 *start_hash);
 276 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 277                 struct ext4_filename *fname,
 278                 struct ext4_dir_entry_2 **res_dir);
 279 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 280                              struct inode *dir, struct inode *inode);
 281
 282 /* checksumming functions */
 283 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 284                             unsigned int blocksize)
 285 {
 286         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 287         t->det_rec_len = ext4_rec_len_to_disk(
 288                         sizeof(struct ext4_dir_entry_tail), blocksize);
 289         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 290 }
 291
 292 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 293 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 294                                                    struct ext4_dir_entry *de)
 295 {
 296         struct ext4_dir_entry_tail *t;
 297
 298 #ifdef PARANOID
 299         struct ext4_dir_entry *d, *top;
 300
 301         d = de;
 302         top = (struct ext4_dir_entry *)(((void *)de) +
 303                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 304                 sizeof(struct ext4_dir_entry_tail)));
 305         while (d < top && d->rec_len)
 306                 d = (struct ext4_dir_entry *)(((void *)d) +
 307                     le16_to_cpu(d->rec_len));
 308
 309         if (d != top)
 310                 return NULL;
 311
 312         t = (struct ext4_dir_entry_tail *)d;
 313 #else
 314         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 315 #endif
 316
 317         if (t->det_reserved_zero1 ||
 318             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 319             t->det_reserved_zero2 ||
 320             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 321                 return NULL;
 322
 323         return t;
 324 }
 325
 326 static __le32 ext4_dirent_csum(struct inode *inode,
 327                                struct ext4_dir_entry *dirent, int size)
 328 {
 329         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 330         struct ext4_inode_info *ei = EXT4_I(inode);
 331         __u32 csum;
 332
 333         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 334         return cpu_to_le32(csum);
 335 }
 336
 337 #define warn_no_space_for_csum(inode)                                   \
 338         __warn_no_space_for_csum((inode), __func__, __LINE__)
 339
 340 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
 341                                      unsigned int line)
 342 {
 343         __ext4_warning_inode(inode, func, line,
 344                 "No space for directory leaf checksum. Please run e2fsck -D.");
 345 }
 346
 347 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 348 {
 349         struct ext4_dir_entry_tail *t;
 350
 351         if (!ext4_has_metadata_csum(inode->i_sb))
 352                 return 1;
 353
 354         t = get_dirent_tail(inode, dirent);
 355         if (!t) {
 356                 warn_no_space_for_csum(inode);
 357                 return 0;
 358         }
 359
 360         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 361                                                 (void *)t - (void *)dirent))
 362                 return 0;
 363
 364         return 1;
 365 }
 366
 367 static void ext4_dirent_csum_set(struct inode *inode,
 368                                  struct ext4_dir_entry *dirent)
 369 {
 370         struct ext4_dir_entry_tail *t;
 371
 372         if (!ext4_has_metadata_csum(inode->i_sb))
 373                 return;
 374
 375         t = get_dirent_tail(inode, dirent);
 376         if (!t) {
 377                 warn_no_space_for_csum(inode);
 378                 return;
 379         }
 380
 381         t->det_checksum = ext4_dirent_csum(inode, dirent,
 382                                            (void *)t - (void *)dirent);
 383 }
 384
 385 int ext4_handle_dirty_dirent_node(handle_t *handle,
 386                                   struct inode *inode,
 387                                   struct buffer_head *bh)
 388 {
 389         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 390         return ext4_handle_dirty_metadata(handle, inode, bh);
 391 }
 392
 393 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 394                                                struct ext4_dir_entry *dirent,
 395                                                int *offset)
 396 {
 397         struct ext4_dir_entry *dp;
 398         struct dx_root_info *root;
 399         int count_offset;
 400
 401         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 402                 count_offset = 8;
 403         else if (le16_to_cpu(dirent->rec_len) == 12) {
 404                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 405                 if (le16_to_cpu(dp->rec_len) !=
 406                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 407                         return NULL;
 408                 root = (struct dx_root_info *)(((void *)dp + 12));
 409                 if (root->reserved_zero ||
 410                     root->info_length != sizeof(struct dx_root_info))
 411                         return NULL;
 412                 count_offset = 32;
 413         } else
 414                 return NULL;
 415
 416         if (offset)
 417                 *offset = count_offset;
 418         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 419 }
 420
 421 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 422                            int count_offset, int count, struct dx_tail *t)
 423 {
 424         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 425         struct ext4_inode_info *ei = EXT4_I(inode);
 426         __u32 csum;
 427         int size;
 428         __u32 dummy_csum = 0;
 429         int offset = offsetof(struct dx_tail, dt_checksum);
 430
 431         size = count_offset + (count * sizeof(struct dx_entry));
 432         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 433         csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
 434         csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
 435
 436         return cpu_to_le32(csum);
 437 }
 438
 439 static int ext4_dx_csum_verify(struct inode *inode,
 440                                struct ext4_dir_entry *dirent)
 441 {
 442         struct dx_countlimit *c;
 443         struct dx_tail *t;
 444         int count_offset, limit, count;
 445
 446         if (!ext4_has_metadata_csum(inode->i_sb))
 447                 return 1;
 448
 449         c = get_dx_countlimit(inode, dirent, &count_offset);
 450         if (!c) {
 451                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 452                 return 0;
 453         }
 454         limit = le16_to_cpu(c->limit);
 455         count = le16_to_cpu(c->count);
 456         if (count_offset + (limit * sizeof(struct dx_entry)) >
 457             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 458                 warn_no_space_for_csum(inode);
 459                 return 0;
 460         }
 461         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 462
 463         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 464                                             count, t))
 465                 return 0;
 466         return 1;
 467 }
 468
 469 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 470 {
 471         struct dx_countlimit *c;
 472         struct dx_tail *t;
 473         int count_offset, limit, count;
 474
 475         if (!ext4_has_metadata_csum(inode->i_sb))
 476                 return;
 477
 478         c = get_dx_countlimit(inode, dirent, &count_offset);
 479         if (!c) {
 480                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 481                 return;
 482         }
 483         limit = le16_to_cpu(c->limit);
 484         count = le16_to_cpu(c->count);
 485         if (count_offset + (limit * sizeof(struct dx_entry)) >
 486             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 487                 warn_no_space_for_csum(inode);
 488                 return;
 489         }
 490         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 491
 492         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 493 }
 494
 495 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 496                                             struct inode *inode,
 497                                             struct buffer_head *bh)
 498 {
 499         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 500         return ext4_handle_dirty_metadata(handle, inode, bh);
 501 }
 502
 503 /*
 504  * p is at least 6 bytes before the end of page
 505  */
 506 static inline struct ext4_dir_entry_2 *
 507 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 508 {
 509         return (struct ext4_dir_entry_2 *)((char *)p +
 510                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 511 }
 512
 513 /*
 514  * Future: use high four bits of block for coalesce-on-delete flags
 515  * Mask them off for now.
 516  */
 517
 518 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 519 {
 520         return le32_to_cpu(entry->block) & 0x0fffffff;
 521 }
 522
 523 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 524 {
 525         entry->block = cpu_to_le32(value);
 526 }
 527
 528 static inline unsigned dx_get_hash(struct dx_entry *entry)
 529 {
 530         return le32_to_cpu(entry->hash);
 531 }
 532
 533 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 534 {
 535         entry->hash = cpu_to_le32(value);
 536 }
 537
 538 static inline unsigned dx_get_count(struct dx_entry *entries)
 539 {
 540         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 541 }
 542
 543 static inline unsigned dx_get_limit(struct dx_entry *entries)
 544 {
 545         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 546 }
 547
 548 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 549 {
 550         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 551 }
 552
 553 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 554 {
 555         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 556 }
 557
 558 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 559 {
 560         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 561                 EXT4_DIR_REC_LEN(2) - infosize;
 562
 563         if (ext4_has_metadata_csum(dir->i_sb))
 564                 entry_space -= sizeof(struct dx_tail);
 565         return entry_space / sizeof(struct dx_entry);
 566 }
 567
 568 static inline unsigned dx_node_limit(struct inode *dir)
 569 {
 570         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 571
 572         if (ext4_has_metadata_csum(dir->i_sb))
 573                 entry_space -= sizeof(struct dx_tail);
 574         return entry_space / sizeof(struct dx_entry);
 575 }
 576
 577 /*
 578  * Debug
 579  */
 580 #ifdef DX_DEBUG
 581 static void dx_show_index(char * label, struct dx_entry *entries)
 582 {
 583         int i, n = dx_get_count (entries);
 584         printk(KERN_DEBUG "%s index", label);
 585         for (i = 0; i < n; i++) {
 586                 printk(KERN_CONT " %x->%lu",
 587                        i ? dx_get_hash(entries + i) : 0,
 588                        (unsigned long)dx_get_block(entries + i));
 589         }
 590         printk(KERN_CONT "\n");
 591 }
 592
 593 struct stats
 594 {
 595         unsigned names;
 596         unsigned space;
 597         unsigned bcount;
 598 };
 599
 600 static struct stats dx_show_leaf(struct inode *dir,
 601                                 struct dx_hash_info *hinfo,
 602                                 struct ext4_dir_entry_2 *de,
 603                                 int size, int show_names)
 604 {
 605         unsigned names = 0, space = 0;
 606         char *base = (char *) de;
 607         struct dx_hash_info h = *hinfo;
 608
 609         printk("names: ");
 610         while ((char *) de < base + size)
 611         {
 612                 if (de->inode)
 613                 {
 614                         if (show_names)
 615                         {
 616 #ifdef CONFIG_FS_ENCRYPTION
 617                                 int len;
 618                                 char *name;
 619                                 struct fscrypt_str fname_crypto_str =
 620                                         FSTR_INIT(NULL, 0);
 621                                 int res = 0;
 622
 623                                 name  = de->name;
 624                                 len = de->name_len;
 625                                 if (IS_ENCRYPTED(dir))
 626                                         res = fscrypt_get_encryption_info(dir);
 627                                 if (res) {
 628                                         printk(KERN_WARNING "Error setting up"
 629                                                " fname crypto: %d\n", res);
 630                                 }
 631                                 if (!fscrypt_has_encryption_key(dir)) {
 632                                         /* Directory is not encrypted */
 633                                         ext4fs_dirhash(dir, de->name,
 634                                                 de->name_len, &h);
 635                                         printk("%*.s:(U)%x.%u ", len,
 636                                                name, h.hash,
 637                                                (unsigned) ((char *) de
 638                                                            - base));
 639                                 } else {
 640                                         struct fscrypt_str de_name =
 641                                                 FSTR_INIT(name, len);
 642
 643                                         /* Directory is encrypted */
 644                                         res = fscrypt_fname_alloc_buffer(
 645                                                 dir, len,
 646                                                 &fname_crypto_str);
 647                                         if (res)
 648                                                 printk(KERN_WARNING "Error "
 649                                                         "allocating crypto "
 650                                                         "buffer--skipping "
 651                                                         "crypto\n");
 652                                         res = fscrypt_fname_disk_to_usr(dir,
 653                                                 0, 0, &de_name,
 654                                                 &fname_crypto_str);
 655                                         if (res) {
 656                                                 printk(KERN_WARNING "Error "
 657                                                         "converting filename "
 658                                                         "from disk to usr"
 659                                                         "\n");
 660                                                 name = "??";
 661                                                 len = 2;
 662                                         } else {
 663                                                 name = fname_crypto_str.name;
 664                                                 len = fname_crypto_str.len;
 665                                         }
 666                                         ext4fs_dirhash(dir, de->name,
 667                                                        de->name_len, &h);
 668                                         printk("%*.s:(E)%x.%u ", len, name,
 669                                                h.hash, (unsigned) ((char *) de
 670                                                                    - base));
 671                                         fscrypt_fname_free_buffer(
 672                                                         &fname_crypto_str);
 673                                 }
 674 #else
 675                                 int len = de->name_len;
 676                                 char *name = de->name;
 677                                 ext4fs_dirhash(dir, de->name, de->name_len, &h);
 678                                 printk("%*.s:%x.%u ", len, name, h.hash,
 679                                        (unsigned) ((char *) de - base));
 680 #endif
 681                         }
 682                         space += EXT4_DIR_REC_LEN(de->name_len);
 683                         names++;
 684                 }
 685                 de = ext4_next_entry(de, size);
 686         }
 687         printk(KERN_CONT "(%i)\n", names);
 688         return (struct stats) { names, space, 1 };
 689 }
 690
 691 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 692                              struct dx_entry *entries, int levels)
 693 {
 694         unsigned blocksize = dir->i_sb->s_blocksize;
 695         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 696         unsigned bcount = 0;
 697         struct buffer_head *bh;
 698         printk("%i indexed blocks...\n", count);
 699         for (i = 0; i < count; i++, entries++)
 700         {
 701                 ext4_lblk_t block = dx_get_block(entries);
 702                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 703                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 704                 struct stats stats;
 705                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 706                 bh = ext4_bread(NULL,dir, block, 0);
 707                 if (!bh || IS_ERR(bh))
 708                         continue;
 709                 stats = levels?
 710                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 711                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 712                         bh->b_data, blocksize, 0);
 713                 names += stats.names;
 714                 space += stats.space;
 715                 bcount += stats.bcount;
 716                 brelse(bh);
 717         }
 718         if (bcount)
 719                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 720                        levels ? "" : "   ", names, space/bcount,
 721                        (space/bcount)*100/blocksize);
 722         return (struct stats) { names, space, bcount};
 723 }
 724 #endif /* DX_DEBUG */
 725
 726 /*
 727  * Probe for a directory leaf block to search.
 728  *
 729  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 730  * error in the directory index, and the caller should fall back to
 731  * searching the directory normally.  The callers of dx_probe **MUST**
 732  * check for this error code, and make sure it never gets reflected
 733  * back to userspace.
 734  */
 735 static struct dx_frame *
 736 dx_probe(struct ext4_filename *fname, struct inode *dir,
 737          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 738 {
 739         unsigned count, indirect;
 740         struct dx_entry *at, *entries, *p, *q, *m;
 741         struct dx_root *root;
 742         struct dx_frame *frame = frame_in;
 743         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 744         u32 hash;
 745
 746         memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
 747         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 748         if (IS_ERR(frame->bh))
 749                 return (struct dx_frame *) frame->bh;
 750
 751         root = (struct dx_root *) frame->bh->b_data;
 752         if (root->info.hash_version != DX_HASH_TEA &&
 753             root->info.hash_version != DX_HASH_HALF_MD4 &&
 754             root->info.hash_version != DX_HASH_LEGACY) {
 755                 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
 756                                    root->info.hash_version);
 757                 goto fail;
 758         }
 759         if (fname)
 760                 hinfo = &fname->hinfo;
 761         hinfo->hash_version = root->info.hash_version;
 762         if (hinfo->hash_version <= DX_HASH_TEA)
 763                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 764         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 765         if (fname && fname_name(fname))
 766                 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
 767         hash = hinfo->hash;
 768
 769         if (root->info.unused_flags & 1) {
 770                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
 771                                    root->info.unused_flags);
 772                 goto fail;
 773         }
 774
 775         indirect = root->info.indirect_levels;
 776         if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
 777                 ext4_warning(dir->i_sb,
 778                              "Directory (ino: %lu) htree depth %#06x exceed"
 779                              "supported value", dir->i_ino,
 780                              ext4_dir_htree_level(dir->i_sb));
 781                 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
 782                         ext4_warning(dir->i_sb, "Enable large directory "
 783                                                 "feature to access it");
 784                 }
 785                 goto fail;
 786         }
 787
 788         entries = (struct dx_entry *)(((char *)&root->info) +
 789                                       root->info.info_length);
 790
 791         if (dx_get_limit(entries) != dx_root_limit(dir,
 792                                                    root->info.info_length)) {
 793                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 794                                    dx_get_limit(entries),
 795                                    dx_root_limit(dir, root->info.info_length));
 796                 goto fail;
 797         }
 798
 799         dxtrace(printk("Look up %x", hash));
 800         while (1) {
 801                 count = dx_get_count(entries);
 802                 if (!count || count > dx_get_limit(entries)) {
 803                         ext4_warning_inode(dir,
 804                                            "dx entry: count %u beyond limit %u",
 805                                            count, dx_get_limit(entries));
 806                         goto fail;
 807                 }
 808
 809                 p = entries + 1;
 810                 q = entries + count - 1;
 811                 while (p <= q) {
 812                         m = p + (q - p) / 2;
 813                         dxtrace(printk(KERN_CONT "."));
 814                         if (dx_get_hash(m) > hash)
 815                                 q = m - 1;
 816                         else
 817                                 p = m + 1;
 818                 }
 819
 820                 if (0) { // linear search cross check
 821                         unsigned n = count - 1;
 822                         at = entries;
 823                         while (n--)
 824                         {
 825                                 dxtrace(printk(KERN_CONT ","));
 826                                 if (dx_get_hash(++at) > hash)
 827                                 {
 828                                         at--;
 829                                         break;
 830                                 }
 831                         }
 832                         assert (at == p - 1);
 833                 }
 834
 835                 at = p - 1;
 836                 dxtrace(printk(KERN_CONT " %x->%u\n",
 837                                at == entries ? 0 : dx_get_hash(at),
 838                                dx_get_block(at)));
 839                 frame->entries = entries;
 840                 frame->at = at;
 841                 if (!indirect--)
 842                         return frame;
 843                 frame++;
 844                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 845                 if (IS_ERR(frame->bh)) {
 846                         ret_err = (struct dx_frame *) frame->bh;
 847                         frame->bh = NULL;
 848                         goto fail;
 849                 }
 850                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 851
 852                 if (dx_get_limit(entries) != dx_node_limit(dir)) {
 853                         ext4_warning_inode(dir,
 854                                 "dx entry: limit %u != node limit %u",
 855                                 dx_get_limit(entries), dx_node_limit(dir));
 856                         goto fail;
 857                 }
 858         }
 859 fail:
 860         while (frame >= frame_in) {
 861                 brelse(frame->bh);
 862                 frame--;
 863         }
 864
 865         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 866                 ext4_warning_inode(dir,
 867                         "Corrupt directory, running e2fsck is recommended");
 868         return ret_err;
 869 }
 870
 871 static void dx_release(struct dx_frame *frames)
 872 {
 873         struct dx_root_info *info;
 874         int i;
 875
 876         if (frames[0].bh == NULL)
 877                 return;
 878
 879         info = &((struct dx_root *)frames[0].bh->b_data)->info;
 880         for (i = 0; i <= info->indirect_levels; i++) {
 881                 if (frames[i].bh == NULL)
 882                         break;
 883                 brelse(frames[i].bh);
 884                 frames[i].bh = NULL;
 885         }
 886 }
 887
 888 /*
 889  * This function increments the frame pointer to search the next leaf
 890  * block, and reads in the necessary intervening nodes if the search
 891  * should be necessary.  Whether or not the search is necessary is
 892  * controlled by the hash parameter.  If the hash value is even, then
 893  * the search is only continued if the next block starts with that
 894  * hash value.  This is used if we are searching for a specific file.
 895  *
 896  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 897  *
 898  * This function returns 1 if the caller should continue to search,
 899  * or 0 if it should not.  If there is an error reading one of the
 900  * index blocks, it will a negative error code.
 901  *
 902  * If start_hash is non-null, it will be filled in with the starting
 903  * hash of the next page.
 904  */
 905 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 906                                  struct dx_frame *frame,
 907                                  struct dx_frame *frames,
 908                                  __u32 *start_hash)
 909 {
 910         struct dx_frame *p;
 911         struct buffer_head *bh;
 912         int num_frames = 0;
 913         __u32 bhash;
 914
 915         p = frame;
 916         /*
 917          * Find the next leaf page by incrementing the frame pointer.
 918          * If we run out of entries in the interior node, loop around and
 919          * increment pointer in the parent node.  When we break out of
 920          * this loop, num_frames indicates the number of interior
 921          * nodes need to be read.
 922          */
 923         while (1) {
 924                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 925                         break;
 926                 if (p == frames)
 927                         return 0;
 928                 num_frames++;
 929                 p--;
 930         }
 931
 932         /*
 933          * If the hash is 1, then continue only if the next page has a
 934          * continuation hash of any value.  This is used for readdir
 935          * handling.  Otherwise, check to see if the hash matches the
 936          * desired contiuation hash.  If it doesn't, return since
 937          * there's no point to read in the successive index pages.
 938          */
 939         bhash = dx_get_hash(p->at);
 940         if (start_hash)
 941                 *start_hash = bhash;
 942         if ((hash & 1) == 0) {
 943                 if ((bhash & ~1) != hash)
 944                         return 0;
 945         }
 946         /*
 947          * If the hash is HASH_NB_ALWAYS, we always go to the next
 948          * block so no check is necessary
 949          */
 950         while (num_frames--) {
 951                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 952                 if (IS_ERR(bh))
 953                         return PTR_ERR(bh);
 954                 p++;
 955                 brelse(p->bh);
 956                 p->bh = bh;
 957                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 958         }
 959         return 1;
 960 }
 961
 962
 963 /*
 964  * This function fills a red-black tree with information from a
 965  * directory block.  It returns the number directory entries loaded
 966  * into the tree.  If there is an error it is returned in err.
 967  */
 968 static int htree_dirblock_to_tree(struct file *dir_file,
 969                                   struct inode *dir, ext4_lblk_t block,
 970                                   struct dx_hash_info *hinfo,
 971                                   __u32 start_hash, __u32 start_minor_hash)
 972 {
 973         struct buffer_head *bh;
 974         struct ext4_dir_entry_2 *de, *top;
 975         int err = 0, count = 0;
 976         struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
 977
 978         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 979                                                         (unsigned long)block));
 980         bh = ext4_read_dirblock(dir, block, DIRENT);
 981         if (IS_ERR(bh))
 982                 return PTR_ERR(bh);
 983
 984         de = (struct ext4_dir_entry_2 *) bh->b_data;
 985         top = (struct ext4_dir_entry_2 *) ((char *) de +
 986                                            dir->i_sb->s_blocksize -
 987                                            EXT4_DIR_REC_LEN(0));
 988 #ifdef CONFIG_FS_ENCRYPTION
 989         /* Check if the directory is encrypted */
 990         if (IS_ENCRYPTED(dir)) {
 991                 err = fscrypt_get_encryption_info(dir);
 992                 if (err < 0) {
 993                         brelse(bh);
 994                         return err;
 995                 }
 996                 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
 997                                                      &fname_crypto_str);
 998                 if (err < 0) {
 999                         brelse(bh);
1000                         return err;
1001                 }
1002         }
1003 #endif
1004         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1005                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1006                                 bh->b_data, bh->b_size,
1007                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1008                                          + ((char *)de - bh->b_data))) {
1009                         /* silently ignore the rest of the block */
1010                         break;
1011                 }
1012                 ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
1013                 if ((hinfo->hash < start_hash) ||
1014                     ((hinfo->hash == start_hash) &&
1015                      (hinfo->minor_hash < start_minor_hash)))
1016                         continue;
1017                 if (de->inode == 0)
1018                         continue;
1019                 if (!IS_ENCRYPTED(dir)) {
1020                         tmp_str.name = de->name;
1021                         tmp_str.len = de->name_len;
1022                         err = ext4_htree_store_dirent(dir_file,
1023                                    hinfo->hash, hinfo->minor_hash, de,
1024                                    &tmp_str);
1025                 } else {
1026                         int save_len = fname_crypto_str.len;
1027                         struct fscrypt_str de_name = FSTR_INIT(de->name,
1028                                                                 de->name_len);
1029
1030                         /* Directory is encrypted */
1031                         err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1032                                         hinfo->minor_hash, &de_name,
1033                                         &fname_crypto_str);
1034                         if (err) {
1035                                 count = err;
1036                                 goto errout;
1037                         }
1038                         err = ext4_htree_store_dirent(dir_file,
1039                                    hinfo->hash, hinfo->minor_hash, de,
1040                                         &fname_crypto_str);
1041                         fname_crypto_str.len = save_len;
1042                 }
1043                 if (err != 0) {
1044                         count = err;
1045                         goto errout;
1046                 }
1047                 count++;
1048         }
1049 errout:
1050         brelse(bh);
1051 #ifdef CONFIG_FS_ENCRYPTION
1052         fscrypt_fname_free_buffer(&fname_crypto_str);
1053 #endif
1054         return count;
1055 }
1056
1057
1058 /*
1059  * This function fills a red-black tree with information from a
1060  * directory.  We start scanning the directory in hash order, starting
1061  * at start_hash and start_minor_hash.
1062  *
1063  * This function returns the number of entries inserted into the tree,
1064  * or a negative error code.
1065  */
1066 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1067                          __u32 start_minor_hash, __u32 *next_hash)
1068 {
1069         struct dx_hash_info hinfo;
1070         struct ext4_dir_entry_2 *de;
1071         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1072         struct inode *dir;
1073         ext4_lblk_t block;
1074         int count = 0;
1075         int ret, err;
1076         __u32 hashval;
1077         struct fscrypt_str tmp_str;
1078
1079         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1080                        start_hash, start_minor_hash));
1081         dir = file_inode(dir_file);
1082         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1083                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1084                 if (hinfo.hash_version <= DX_HASH_TEA)
1085                         hinfo.hash_version +=
1086                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1087                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1088                 if (ext4_has_inline_data(dir)) {
1089                         int has_inline_data = 1;
1090                         count = htree_inlinedir_to_tree(dir_file, dir, 0,
1091                                                         &hinfo, start_hash,
1092                                                         start_minor_hash,
1093                                                         &has_inline_data);
1094                         if (has_inline_data) {
1095                                 *next_hash = ~0;
1096                                 return count;
1097                         }
1098                 }
1099                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1100                                                start_hash, start_minor_hash);
1101                 *next_hash = ~0;
1102                 return count;
1103         }
1104         hinfo.hash = start_hash;
1105         hinfo.minor_hash = 0;
1106         frame = dx_probe(NULL, dir, &hinfo, frames);
1107         if (IS_ERR(frame))
1108                 return PTR_ERR(frame);
1109
1110         /* Add '.' and '..' from the htree header */
1111         if (!start_hash && !start_minor_hash) {
1112                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1113                 tmp_str.name = de->name;
1114                 tmp_str.len = de->name_len;
1115                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1116                                               de, &tmp_str);
1117                 if (err != 0)
1118                         goto errout;
1119                 count++;
1120         }
1121         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1122                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1123                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1124                 tmp_str.name = de->name;
1125                 tmp_str.len = de->name_len;
1126                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1127                                               de, &tmp_str);
1128                 if (err != 0)
1129                         goto errout;
1130                 count++;
1131         }
1132
1133         while (1) {
1134                 if (fatal_signal_pending(current)) {
1135                         err = -ERESTARTSYS;
1136                         goto errout;
1137                 }
1138                 cond_resched();
1139                 block = dx_get_block(frame->at);
1140                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1141                                              start_hash, start_minor_hash);
1142                 if (ret < 0) {
1143                         err = ret;
1144                         goto errout;
1145                 }
1146                 count += ret;
1147                 hashval = ~0;
1148                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1149                                             frame, frames, &hashval);
1150                 *next_hash = hashval;
1151                 if (ret < 0) {
1152                         err = ret;
1153                         goto errout;
1154                 }
1155                 /*
1156                  * Stop if:  (a) there are no more entries, or
1157                  * (b) we have inserted at least one entry and the
1158                  * next hash value is not a continuation
1159                  */
1160                 if ((ret == 0) ||
1161                     (count && ((hashval & 1) == 0)))
1162                         break;
1163         }
1164         dx_release(frames);
1165         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1166                        "next hash: %x\n", count, *next_hash));
1167         return count;
1168 errout:
1169         dx_release(frames);
1170         return (err);
1171 }
1172
1173 static inline int search_dirblock(struct buffer_head *bh,
1174                                   struct inode *dir,
1175                                   struct ext4_filename *fname,
1176                                   unsigned int offset,
1177                                   struct ext4_dir_entry_2 **res_dir)
1178 {
1179         return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1180                                fname, offset, res_dir);
1181 }
1182
1183 /*
1184  * Directory block splitting, compacting
1185  */
1186
1187 /*
1188  * Create map of hash values, offsets, and sizes, stored at end of block.
1189  * Returns number of entries mapped.
1190  */
1191 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1192                        unsigned blocksize, struct dx_hash_info *hinfo,
1193                        struct dx_map_entry *map_tail)
1194 {
1195         int count = 0;
1196         char *base = (char *) de;
1197         struct dx_hash_info h = *hinfo;
1198
1199         while ((char *) de < base + blocksize) {
1200                 if (de->name_len && de->inode) {
1201                         ext4fs_dirhash(dir, de->name, de->name_len, &h);
1202                         map_tail--;
1203                         map_tail->hash = h.hash;
1204                         map_tail->offs = ((char *) de - base)>>2;
1205                         map_tail->size = le16_to_cpu(de->rec_len);
1206                         count++;
1207                         cond_resched();
1208                 }
1209                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1210                 de = ext4_next_entry(de, blocksize);
1211         }
1212         return count;
1213 }
1214
1215 /* Sort map by hash value */
1216 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1217 {
1218         struct dx_map_entry *p, *q, *top = map + count - 1;
1219         int more;
1220         /* Combsort until bubble sort doesn't suck */
1221         while (count > 2) {
1222                 count = count*10/13;
1223                 if (count - 9 < 2) /* 9, 10 -> 11 */
1224                         count = 11;
1225                 for (p = top, q = p - count; q >= map; p--, q--)
1226                         if (p->hash < q->hash)
1227                                 swap(*p, *q);
1228         }
1229         /* Garden variety bubble sort */
1230         do {
1231                 more = 0;
1232                 q = top;
1233                 while (q-- > map) {
1234                         if (q[1].hash >= q[0].hash)
1235                                 continue;
1236                         swap(*(q+1), *q);
1237                         more = 1;
1238                 }
1239         } while(more);
1240 }
1241
1242 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1243 {
1244         struct dx_entry *entries = frame->entries;
1245         struct dx_entry *old = frame->at, *new = old + 1;
1246         int count = dx_get_count(entries);
1247
1248         assert(count < dx_get_limit(entries));
1249         assert(old < entries + count);
1250         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1251         dx_set_hash(new, hash);
1252         dx_set_block(new, block);
1253         dx_set_count(entries, count + 1);
1254 }
1255
1256 #ifdef CONFIG_UNICODE
1257 /*
1258  * Test whether a case-insensitive directory entry matches the filename
1259  * being searched for.
1260  *
1261  * Returns: 0 if the directory entry matches, more than 0 if it
1262  * doesn't match or less than zero on error.
1263  */
1264 int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
1265                     const struct qstr *entry)
1266 {
1267         const struct ext4_sb_info *sbi = EXT4_SB(parent->i_sb);
1268         const struct unicode_map *um = sbi->s_encoding;
1269         int ret;
1270
1271         ret = utf8_strncasecmp(um, name, entry);
1272         if (ret < 0) {
1273                 /* Handle invalid character sequence as either an error
1274                  * or as an opaque byte sequence.
1275                  */
1276                 if (ext4_has_strict_mode(sbi))
1277                         return -EINVAL;
1278
1279                 if (name->len != entry->len)
1280                         return 1;
1281
1282                 return !!memcmp(name->name, entry->name, name->len);
1283         }
1284
1285         return ret;
1286 }
1287 #endif
1288
1289 /*
1290  * Test whether a directory entry matches the filename being searched for.
1291  *
1292  * Return: %true if the directory entry matches, otherwise %false.
1293  */
1294 static inline bool ext4_match(const struct inode *parent,
1295                               const struct ext4_filename *fname,
1296                               const struct ext4_dir_entry_2 *de)
1297 {
1298         struct fscrypt_name f;
1299 #ifdef CONFIG_UNICODE
1300         const struct qstr entry = {.name = de->name, .len = de->name_len};
1301 #endif
1302
1303         if (!de->inode)
1304                 return false;
1305
1306         f.usr_fname = fname->usr_fname;
1307         f.disk_name = fname->disk_name;
1308 #ifdef CONFIG_FS_ENCRYPTION
1309         f.crypto_buf = fname->crypto_buf;
1310 #endif
1311
1312 #ifdef CONFIG_UNICODE
1313         if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent))
1314                 return (ext4_ci_compare(parent, fname->usr_fname, &entry) == 0);
1315 #endif
1316
1317         return fscrypt_match_name(&f, de->name, de->name_len);
1318 }
1319
1320 /*
1321  * Returns 0 if not found, -1 on failure, and 1 on success
1322  */
1323 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1324                     struct inode *dir, struct ext4_filename *fname,
1325                     unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1326 {
1327         struct ext4_dir_entry_2 * de;
1328         char * dlimit;
1329         int de_len;
1330
1331         de = (struct ext4_dir_entry_2 *)search_buf;
1332         dlimit = search_buf + buf_size;
1333         while ((char *) de < dlimit) {
1334                 /* this code is executed quadratically often */
1335                 /* do minimal checking `by hand' */
1336                 if ((char *) de + de->name_len <= dlimit &&
1337                     ext4_match(dir, fname, de)) {
1338                         /* found a match - just to be sure, do
1339                          * a full check */
1340                         if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1341                                                  bh->b_size, offset))
1342                                 return -1;
1343                         *res_dir = de;
1344                         return 1;
1345                 }
1346                 /* prevent looping on a bad block */
1347                 de_len = ext4_rec_len_from_disk(de->rec_len,
1348                                                 dir->i_sb->s_blocksize);
1349                 if (de_len <= 0)
1350                         return -1;
1351                 offset += de_len;
1352                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1353         }
1354         return 0;
1355 }
1356
1357 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1358                                struct ext4_dir_entry *de)
1359 {
1360         struct super_block *sb = dir->i_sb;
1361
1362         if (!is_dx(dir))
1363                 return 0;
1364         if (block == 0)
1365                 return 1;
1366         if (de->inode == 0 &&
1367             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1368                         sb->s_blocksize)
1369                 return 1;
1370         return 0;
1371 }
1372
1373 /*
1374  *      __ext4_find_entry()
1375  *
1376  * finds an entry in the specified directory with the wanted name. It
1377  * returns the cache buffer in which the entry was found, and the entry
1378  * itself (as a parameter - res_dir). It does NOT read the inode of the
1379  * entry - you'll have to do that yourself if you want to.
1380  *
1381  * The returned buffer_head has ->b_count elevated.  The caller is expected
1382  * to brelse() it when appropriate.
1383  */
1384 static struct buffer_head *__ext4_find_entry(struct inode *dir,
1385                                              struct ext4_filename *fname,
1386                                              struct ext4_dir_entry_2 **res_dir,
1387                                              int *inlined)
1388 {
1389         struct super_block *sb;
1390         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1391         struct buffer_head *bh, *ret = NULL;
1392         ext4_lblk_t start, block;
1393         const u8 *name = fname->usr_fname->name;
1394         size_t ra_max = 0;      /* Number of bh's in the readahead
1395                                    buffer, bh_use[] */
1396         size_t ra_ptr = 0;      /* Current index into readahead
1397                                    buffer */
1398         ext4_lblk_t  nblocks;
1399         int i, namelen, retval;
1400
1401         *res_dir = NULL;
1402         sb = dir->i_sb;
1403         namelen = fname->usr_fname->len;
1404         if (namelen > EXT4_NAME_LEN)
1405                 return NULL;
1406
1407         if (ext4_has_inline_data(dir)) {
1408                 int has_inline_data = 1;
1409                 ret = ext4_find_inline_entry(dir, fname, res_dir,
1410                                              &has_inline_data);
1411                 if (has_inline_data) {
1412                         if (inlined)
1413                                 *inlined = 1;
1414                         goto cleanup_and_exit;
1415                 }
1416         }
1417
1418         if ((namelen <= 2) && (name[0] == '.') &&
1419             (name[1] == '.' || name[1] == '\0')) {
1420                 /*
1421                  * "." or ".." will only be in the first block
1422                  * NFS may look up ".."; "." should be handled by the VFS
1423                  */
1424                 block = start = 0;
1425                 nblocks = 1;
1426                 goto restart;
1427         }
1428         if (is_dx(dir)) {
1429                 ret = ext4_dx_find_entry(dir, fname, res_dir);
1430                 /*
1431                  * On success, or if the error was file not found,
1432                  * return.  Otherwise, fall back to doing a search the
1433                  * old fashioned way.
1434                  */
1435                 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1436                         goto cleanup_and_exit;
1437                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1438                                "falling back\n"));
1439                 ret = NULL;
1440         }
1441         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1442         if (!nblocks) {
1443                 ret = NULL;
1444                 goto cleanup_and_exit;
1445         }
1446         start = EXT4_I(dir)->i_dir_start_lookup;
1447         if (start >= nblocks)
1448                 start = 0;
1449         block = start;
1450 restart:
1451         do {
1452                 /*
1453                  * We deal with the read-ahead logic here.
1454                  */
1455                 if (ra_ptr >= ra_max) {
1456                         /* Refill the readahead buffer */
1457                         ra_ptr = 0;
1458                         if (block < start)
1459                                 ra_max = start - block;
1460                         else
1461                                 ra_max = nblocks - block;
1462                         ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1463                         retval = ext4_bread_batch(dir, block, ra_max,
1464                                                   false /* wait */, bh_use);
1465                         if (retval) {
1466                                 ret = ERR_PTR(retval);
1467                                 ra_max = 0;
1468                                 goto cleanup_and_exit;
1469                         }
1470                 }
1471                 if ((bh = bh_use[ra_ptr++]) == NULL)
1472                         goto next;
1473                 wait_on_buffer(bh);
1474                 if (!buffer_uptodate(bh)) {
1475                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1476                                          (unsigned long) block);
1477                         brelse(bh);
1478                         ret = ERR_PTR(-EIO);
1479                         goto cleanup_and_exit;
1480                 }
1481                 if (!buffer_verified(bh) &&
1482                     !is_dx_internal_node(dir, block,
1483                                          (struct ext4_dir_entry *)bh->b_data) &&
1484                     !ext4_dirent_csum_verify(dir,
1485                                 (struct ext4_dir_entry *)bh->b_data)) {
1486                         EXT4_ERROR_INODE(dir, "checksumming directory "
1487                                          "block %lu", (unsigned long)block);
1488                         brelse(bh);
1489                         ret = ERR_PTR(-EFSBADCRC);
1490                         goto cleanup_and_exit;
1491                 }
1492                 set_buffer_verified(bh);
1493                 i = search_dirblock(bh, dir, fname,
1494                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1495                 if (i == 1) {
1496                         EXT4_I(dir)->i_dir_start_lookup = block;
1497                         ret = bh;
1498                         goto cleanup_and_exit;
1499                 } else {
1500                         brelse(bh);
1501                         if (i < 0)
1502                                 goto cleanup_and_exit;
1503                 }
1504         next:
1505                 if (++block >= nblocks)
1506                         block = 0;
1507         } while (block != start);
1508
1509         /*
1510          * If the directory has grown while we were searching, then
1511          * search the last part of the directory before giving up.
1512          */
1513         block = nblocks;
1514         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1515         if (block < nblocks) {
1516                 start = 0;
1517                 goto restart;
1518         }
1519
1520 cleanup_and_exit:
1521         /* Clean up the read-ahead blocks */
1522         for (; ra_ptr < ra_max; ra_ptr++)
1523                 brelse(bh_use[ra_ptr]);
1524         return ret;
1525 }
1526
1527 static struct buffer_head *ext4_find_entry(struct inode *dir,
1528                                            const struct qstr *d_name,
1529                                            struct ext4_dir_entry_2 **res_dir,
1530                                            int *inlined)
1531 {
1532         int err;
1533         struct ext4_filename fname;
1534         struct buffer_head *bh;
1535
1536         err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1537         if (err == -ENOENT)
1538                 return NULL;
1539         if (err)
1540                 return ERR_PTR(err);
1541
1542         bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
1543
1544         ext4_fname_free_filename(&fname);
1545         return bh;
1546 }
1547
1548 static struct buffer_head *ext4_lookup_entry(struct inode *dir,
1549                                              struct dentry *dentry,
1550                                              struct ext4_dir_entry_2 **res_dir)
1551 {
1552         int err;
1553         struct ext4_filename fname;
1554         struct buffer_head *bh;
1555
1556         err = ext4_fname_prepare_lookup(dir, dentry, &fname);
1557         if (err == -ENOENT)
1558                 return NULL;
1559         if (err)
1560                 return ERR_PTR(err);
1561
1562         bh = __ext4_find_entry(dir, &fname, res_dir, NULL);
1563
1564         ext4_fname_free_filename(&fname);
1565         return bh;
1566 }
1567
1568 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1569                         struct ext4_filename *fname,
1570                         struct ext4_dir_entry_2 **res_dir)
1571 {
1572         struct super_block * sb = dir->i_sb;
1573         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1574         struct buffer_head *bh;
1575         ext4_lblk_t block;
1576         int retval;
1577
1578 #ifdef CONFIG_FS_ENCRYPTION
1579         *res_dir = NULL;
1580 #endif
1581         frame = dx_probe(fname, dir, NULL, frames);
1582         if (IS_ERR(frame))
1583                 return (struct buffer_head *) frame;
1584         do {
1585                 block = dx_get_block(frame->at);
1586                 bh = ext4_read_dirblock(dir, block, DIRENT);
1587                 if (IS_ERR(bh))
1588                         goto errout;
1589
1590                 retval = search_dirblock(bh, dir, fname,
1591                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1592                                          res_dir);
1593                 if (retval == 1)
1594                         goto success;
1595                 brelse(bh);
1596                 if (retval == -1) {
1597                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1598                         goto errout;
1599                 }
1600
1601                 /* Check to see if we should continue to search */
1602                 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1603                                                frames, NULL);
1604                 if (retval < 0) {
1605                         ext4_warning_inode(dir,
1606                                 "error %d reading directory index block",
1607                                 retval);
1608                         bh = ERR_PTR(retval);
1609                         goto errout;
1610                 }
1611         } while (retval == 1);
1612
1613         bh = NULL;
1614 errout:
1615         dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1616 success:
1617         dx_release(frames);
1618         return bh;
1619 }
1620
1621 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1622 {
1623         struct inode *inode;
1624         struct ext4_dir_entry_2 *de;
1625         struct buffer_head *bh;
1626
1627         if (dentry->d_name.len > EXT4_NAME_LEN)
1628                 return ERR_PTR(-ENAMETOOLONG);
1629
1630         bh = ext4_lookup_entry(dir, dentry, &de);
1631         if (IS_ERR(bh))
1632                 return ERR_CAST(bh);
1633         inode = NULL;
1634         if (bh) {
1635                 __u32 ino = le32_to_cpu(de->inode);
1636                 brelse(bh);
1637                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1638                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1639                         return ERR_PTR(-EFSCORRUPTED);
1640                 }
1641                 if (unlikely(ino == dir->i_ino)) {
1642                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1643                                          dentry);
1644                         return ERR_PTR(-EFSCORRUPTED);
1645                 }
1646                 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
1647                 if (inode == ERR_PTR(-ESTALE)) {
1648                         EXT4_ERROR_INODE(dir,
1649                                          "deleted inode referenced: %u",
1650                                          ino);
1651                         return ERR_PTR(-EFSCORRUPTED);
1652                 }
1653                 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) &&
1654                     (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1655                     !fscrypt_has_permitted_context(dir, inode)) {
1656                         ext4_warning(inode->i_sb,
1657                                      "Inconsistent encryption contexts: %lu/%lu",
1658                                      dir->i_ino, inode->i_ino);
1659                         iput(inode);
1660                         return ERR_PTR(-EPERM);
1661                 }
1662         }
1663
1664 #ifdef CONFIG_UNICODE
1665         if (!inode && IS_CASEFOLDED(dir)) {
1666                 /* Eventually we want to call d_add_ci(dentry, NULL)
1667                  * for negative dentries in the encoding case as
1668                  * well.  For now, prevent the negative dentry
1669                  * from being cached.
1670                  */
1671                 return NULL;
1672         }
1673 #endif
1674         return d_splice_alias(inode, dentry);
1675 }
1676
1677
1678 struct dentry *ext4_get_parent(struct dentry *child)
1679 {
1680         __u32 ino;
1681         static const struct qstr dotdot = QSTR_INIT("..", 2);
1682         struct ext4_dir_entry_2 * de;
1683         struct buffer_head *bh;
1684
1685         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1686         if (IS_ERR(bh))
1687                 return ERR_CAST(bh);
1688         if (!bh)
1689                 return ERR_PTR(-ENOENT);
1690         ino = le32_to_cpu(de->inode);
1691         brelse(bh);
1692
1693         if (!ext4_valid_inum(child->d_sb, ino)) {
1694                 EXT4_ERROR_INODE(d_inode(child),
1695                                  "bad parent inode number: %u", ino);
1696                 return ERR_PTR(-EFSCORRUPTED);
1697         }
1698
1699         return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
1700 }
1701
1702 /*
1703  * Move count entries from end of map between two memory locations.
1704  * Returns pointer to last entry moved.
1705  */
1706 static struct ext4_dir_entry_2 *
1707 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1708                 unsigned blocksize)
1709 {
1710         unsigned rec_len = 0;
1711
1712         while (count--) {
1713                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1714                                                 (from + (map->offs<<2));
1715                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1716                 memcpy (to, de, rec_len);
1717                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1718                                 ext4_rec_len_to_disk(rec_len, blocksize);
1719                 de->inode = 0;
1720                 map++;
1721                 to += rec_len;
1722         }
1723         return (struct ext4_dir_entry_2 *) (to - rec_len);
1724 }
1725
1726 /*
1727  * Compact each dir entry in the range to the minimal rec_len.
1728  * Returns pointer to last entry in range.
1729  */
1730 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1731 {
1732         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1733         unsigned rec_len = 0;
1734
1735         prev = to = de;
1736         while ((char*)de < base + blocksize) {
1737                 next = ext4_next_entry(de, blocksize);
1738                 if (de->inode && de->name_len) {
1739                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1740                         if (de > to)
1741                                 memmove(to, de, rec_len);
1742                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1743                         prev = to;
1744                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1745                 }
1746                 de = next;
1747         }
1748         return prev;
1749 }
1750
1751 /*
1752  * Split a full leaf block to make room for a new dir entry.
1753  * Allocate a new block, and move entries so that they are approx. equally full.
1754  * Returns pointer to de in block into which the new entry will be inserted.
1755  */
1756 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1757                         struct buffer_head **bh,struct dx_frame *frame,
1758                         struct dx_hash_info *hinfo)
1759 {
1760         unsigned blocksize = dir->i_sb->s_blocksize;
1761         unsigned count, continued;
1762         struct buffer_head *bh2;
1763         ext4_lblk_t newblock;
1764         u32 hash2;
1765         struct dx_map_entry *map;
1766         char *data1 = (*bh)->b_data, *data2;
1767         unsigned split, move, size;
1768         struct ext4_dir_entry_2 *de = NULL, *de2;
1769         struct ext4_dir_entry_tail *t;
1770         int     csum_size = 0;
1771         int     err = 0, i;
1772
1773         if (ext4_has_metadata_csum(dir->i_sb))
1774                 csum_size = sizeof(struct ext4_dir_entry_tail);
1775
1776         bh2 = ext4_append(handle, dir, &newblock);
1777         if (IS_ERR(bh2)) {
1778                 brelse(*bh);
1779                 *bh = NULL;
1780                 return (struct ext4_dir_entry_2 *) bh2;
1781         }
1782
1783         BUFFER_TRACE(*bh, "get_write_access");
1784         err = ext4_journal_get_write_access(handle, *bh);
1785         if (err)
1786                 goto journal_error;
1787
1788         BUFFER_TRACE(frame->bh, "get_write_access");
1789         err = ext4_journal_get_write_access(handle, frame->bh);
1790         if (err)
1791                 goto journal_error;
1792
1793         data2 = bh2->b_data;
1794
1795         /* create map in the end of data2 block */
1796         map = (struct dx_map_entry *) (data2 + blocksize);
1797         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1798                              blocksize, hinfo, map);
1799         map -= count;
1800         dx_sort_map(map, count);
1801         /* Split the existing block in the middle, size-wise */
1802         size = 0;
1803         move = 0;
1804         for (i = count-1; i >= 0; i--) {
1805                 /* is more than half of this entry in 2nd half of the block? */
1806                 if (size + map[i].size/2 > blocksize/2)
1807                         break;
1808                 size += map[i].size;
1809                 move++;
1810         }
1811         /* map index at which we will split */
1812         split = count - move;
1813         hash2 = map[split].hash;
1814         continued = hash2 == map[split - 1].hash;
1815         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1816                         (unsigned long)dx_get_block(frame->at),
1817                                         hash2, split, count-split));
1818
1819         /* Fancy dance to stay within two buffers */
1820         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1821                               blocksize);
1822         de = dx_pack_dirents(data1, blocksize);
1823         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1824                                            (char *) de,
1825                                            blocksize);
1826         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1827                                             (char *) de2,
1828                                             blocksize);
1829         if (csum_size) {
1830                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1831                 initialize_dirent_tail(t, blocksize);
1832
1833                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1834                 initialize_dirent_tail(t, blocksize);
1835         }
1836
1837         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1838                         blocksize, 1));
1839         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1840                         blocksize, 1));
1841
1842         /* Which block gets the new entry? */
1843         if (hinfo->hash >= hash2) {
1844                 swap(*bh, bh2);
1845                 de = de2;
1846         }
1847         dx_insert_block(frame, hash2 + continued, newblock);
1848         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1849         if (err)
1850                 goto journal_error;
1851         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1852         if (err)
1853                 goto journal_error;
1854         brelse(bh2);
1855         dxtrace(dx_show_index("frame", frame->entries));
1856         return de;
1857
1858 journal_error:
1859         brelse(*bh);
1860         brelse(bh2);
1861         *bh = NULL;
1862         ext4_std_error(dir->i_sb, err);
1863         return ERR_PTR(err);
1864 }
1865
1866 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1867                       struct buffer_head *bh,
1868                       void *buf, int buf_size,
1869                       struct ext4_filename *fname,
1870                       struct ext4_dir_entry_2 **dest_de)
1871 {
1872         struct ext4_dir_entry_2 *de;
1873         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1874         int nlen, rlen;
1875         unsigned int offset = 0;
1876         char *top;
1877
1878         de = (struct ext4_dir_entry_2 *)buf;
1879         top = buf + buf_size - reclen;
1880         while ((char *) de <= top) {
1881                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1882                                          buf, buf_size, offset))
1883                         return -EFSCORRUPTED;
1884                 if (ext4_match(dir, fname, de))
1885                         return -EEXIST;
1886                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1887                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1888                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1889                         break;
1890                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1891                 offset += rlen;
1892         }
1893         if ((char *) de > top)
1894                 return -ENOSPC;
1895
1896         *dest_de = de;
1897         return 0;
1898 }
1899
1900 void ext4_insert_dentry(struct inode *inode,
1901                         struct ext4_dir_entry_2 *de,
1902                         int buf_size,
1903                         struct ext4_filename *fname)
1904 {
1905
1906         int nlen, rlen;
1907
1908         nlen = EXT4_DIR_REC_LEN(de->name_len);
1909         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1910         if (de->inode) {
1911                 struct ext4_dir_entry_2 *de1 =
1912                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1913                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1914                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1915                 de = de1;
1916         }
1917         de->file_type = EXT4_FT_UNKNOWN;
1918         de->inode = cpu_to_le32(inode->i_ino);
1919         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1920         de->name_len = fname_len(fname);
1921         memcpy(de->name, fname_name(fname), fname_len(fname));
1922 }
1923
1924 /*
1925  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1926  * it points to a directory entry which is guaranteed to be large
1927  * enough for new directory entry.  If de is NULL, then
1928  * add_dirent_to_buf will attempt search the directory block for
1929  * space.  It will return -ENOSPC if no space is available, and -EIO
1930  * and -EEXIST if directory entry already exists.
1931  */
1932 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1933                              struct inode *dir,
1934                              struct inode *inode, struct ext4_dir_entry_2 *de,
1935                              struct buffer_head *bh)
1936 {
1937         unsigned int    blocksize = dir->i_sb->s_blocksize;
1938         int             csum_size = 0;
1939         int             err;
1940
1941         if (ext4_has_metadata_csum(inode->i_sb))
1942                 csum_size = sizeof(struct ext4_dir_entry_tail);
1943
1944         if (!de) {
1945                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1946                                         blocksize - csum_size, fname, &de);
1947                 if (err)
1948                         return err;
1949         }
1950         BUFFER_TRACE(bh, "get_write_access");
1951         err = ext4_journal_get_write_access(handle, bh);
1952         if (err) {
1953                 ext4_std_error(dir->i_sb, err);
1954                 return err;
1955         }
1956
1957         /* By now the buffer is marked for journaling */
1958         ext4_insert_dentry(inode, de, blocksize, fname);
1959
1960         /*
1961          * XXX shouldn't update any times until successful
1962          * completion of syscall, but too many callers depend
1963          * on this.
1964          *
1965          * XXX similarly, too many callers depend on
1966          * ext4_new_inode() setting the times, but error
1967          * recovery deletes the inode, so the worst that can
1968          * happen is that the times are slightly out of date
1969          * and/or different from the directory change time.
1970          */
1971         dir->i_mtime = dir->i_ctime = current_time(dir);
1972         ext4_update_dx_flag(dir);
1973         inode_inc_iversion(dir);
1974         ext4_mark_inode_dirty(handle, dir);
1975         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1976         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1977         if (err)
1978                 ext4_std_error(dir->i_sb, err);
1979         return 0;
1980 }
1981
1982 /*
1983  * This converts a one block unindexed directory to a 3 block indexed
1984  * directory, and adds the dentry to the indexed directory.
1985  */
1986 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1987                             struct inode *dir,
1988                             struct inode *inode, struct buffer_head *bh)
1989 {
1990         struct buffer_head *bh2;
1991         struct dx_root  *root;
1992         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1993         struct dx_entry *entries;
1994         struct ext4_dir_entry_2 *de, *de2;
1995         struct ext4_dir_entry_tail *t;
1996         char            *data1, *top;
1997         unsigned        len;
1998         int             retval;
1999         unsigned        blocksize;
2000         ext4_lblk_t  block;
2001         struct fake_dirent *fde;
2002         int csum_size = 0;
2003
2004         if (ext4_has_metadata_csum(inode->i_sb))
2005                 csum_size = sizeof(struct ext4_dir_entry_tail);
2006
2007         blocksize =  dir->i_sb->s_blocksize;
2008         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2009         BUFFER_TRACE(bh, "get_write_access");
2010         retval = ext4_journal_get_write_access(handle, bh);
2011         if (retval) {
2012                 ext4_std_error(dir->i_sb, retval);
2013                 brelse(bh);
2014                 return retval;
2015         }
2016         root = (struct dx_root *) bh->b_data;
2017
2018         /* The 0th block becomes the root, move the dirents out */
2019         fde = &root->dotdot;
2020         de = (struct ext4_dir_entry_2 *)((char *)fde +
2021                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2022         if ((char *) de >= (((char *) root) + blocksize)) {
2023                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2024                 brelse(bh);
2025                 return -EFSCORRUPTED;
2026         }
2027         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2028
2029         /* Allocate new block for the 0th block's dirents */
2030         bh2 = ext4_append(handle, dir, &block);
2031         if (IS_ERR(bh2)) {
2032                 brelse(bh);
2033                 return PTR_ERR(bh2);
2034         }
2035         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2036         data1 = bh2->b_data;
2037
2038         memcpy (data1, de, len);
2039         de = (struct ext4_dir_entry_2 *) data1;
2040         top = data1 + len;
2041         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2042                 de = de2;
2043         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2044                                            (char *) de,
2045                                            blocksize);
2046
2047         if (csum_size) {
2048                 t = EXT4_DIRENT_TAIL(data1, blocksize);
2049                 initialize_dirent_tail(t, blocksize);
2050         }
2051
2052         /* Initialize the root; the dot dirents already exist */
2053         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2054         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2055                                            blocksize);
2056         memset (&root->info, 0, sizeof(root->info));
2057         root->info.info_length = sizeof(root->info);
2058         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2059         entries = root->entries;
2060         dx_set_block(entries, 1);
2061         dx_set_count(entries, 1);
2062         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2063
2064         /* Initialize as for dx_probe */
2065         fname->hinfo.hash_version = root->info.hash_version;
2066         if (fname->hinfo.hash_version <= DX_HASH_TEA)
2067                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2068         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2069         ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo);
2070
2071         memset(frames, 0, sizeof(frames));
2072         frame = frames;
2073         frame->entries = entries;
2074         frame->at = entries;
2075         frame->bh = bh;
2076
2077         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2078         if (retval)
2079                 goto out_frames;
2080         retval = ext4_handle_dirty_dirent_node(handle, dir, bh2);
2081         if (retval)
2082                 goto out_frames;
2083
2084         de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2085         if (IS_ERR(de)) {
2086                 retval = PTR_ERR(de);
2087                 goto out_frames;
2088         }
2089
2090         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2091 out_frames:
2092         /*
2093          * Even if the block split failed, we have to properly write
2094          * out all the changes we did so far. Otherwise we can end up
2095          * with corrupted filesystem.
2096          */
2097         if (retval)
2098                 ext4_mark_inode_dirty(handle, dir);
2099         dx_release(frames);
2100         brelse(bh2);
2101         return retval;
2102 }
2103
2104 /*
2105  *      ext4_add_entry()
2106  *
2107  * adds a file entry to the specified directory, using the same
2108  * semantics as ext4_find_entry(). It returns NULL if it failed.
2109  *
2110  * NOTE!! The inode part of 'de' is left at 0 - which means you
2111  * may not sleep between calling this and putting something into
2112  * the entry, as someone else might have used it while you slept.
2113  */
2114 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2115                           struct inode *inode)
2116 {
2117         struct inode *dir = d_inode(dentry->d_parent);
2118         struct buffer_head *bh = NULL;
2119         struct ext4_dir_entry_2 *de;
2120         struct ext4_dir_entry_tail *t;
2121         struct super_block *sb;
2122         struct ext4_sb_info *sbi;
2123         struct ext4_filename fname;
2124         int     retval;
2125         int     dx_fallback=0;
2126         unsigned blocksize;
2127         ext4_lblk_t block, blocks;
2128         int     csum_size = 0;
2129
2130         if (ext4_has_metadata_csum(inode->i_sb))
2131                 csum_size = sizeof(struct ext4_dir_entry_tail);
2132
2133         sb = dir->i_sb;
2134         sbi = EXT4_SB(sb);
2135         blocksize = sb->s_blocksize;
2136         if (!dentry->d_name.len)
2137                 return -EINVAL;
2138
2139 #ifdef CONFIG_UNICODE
2140         if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) &&
2141             utf8_validate(sbi->s_encoding, &dentry->d_name))
2142                 return -EINVAL;
2143 #endif
2144
2145         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2146         if (retval)
2147                 return retval;
2148
2149         if (ext4_has_inline_data(dir)) {
2150                 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2151                 if (retval < 0)
2152                         goto out;
2153                 if (retval == 1) {
2154                         retval = 0;
2155                         goto out;
2156                 }
2157         }
2158
2159         if (is_dx(dir)) {
2160                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2161                 if (!retval || (retval != ERR_BAD_DX_DIR))
2162                         goto out;
2163                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2164                 dx_fallback++;
2165                 ext4_mark_inode_dirty(handle, dir);
2166         }
2167         blocks = dir->i_size >> sb->s_blocksize_bits;
2168         for (block = 0; block < blocks; block++) {
2169                 bh = ext4_read_dirblock(dir, block, DIRENT);
2170                 if (IS_ERR(bh)) {
2171                         retval = PTR_ERR(bh);
2172                         bh = NULL;
2173                         goto out;
2174                 }
2175                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2176                                            NULL, bh);
2177                 if (retval != -ENOSPC)
2178                         goto out;
2179
2180                 if (blocks == 1 && !dx_fallback &&
2181                     ext4_has_feature_dir_index(sb)) {
2182                         retval = make_indexed_dir(handle, &fname, dir,
2183                                                   inode, bh);
2184                         bh = NULL; /* make_indexed_dir releases bh */
2185                         goto out;
2186                 }
2187                 brelse(bh);
2188         }
2189         bh = ext4_append(handle, dir, &block);
2190         if (IS_ERR(bh)) {
2191                 retval = PTR_ERR(bh);
2192                 bh = NULL;
2193                 goto out;
2194         }
2195         de = (struct ext4_dir_entry_2 *) bh->b_data;
2196         de->inode = 0;
2197         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2198
2199         if (csum_size) {
2200                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2201                 initialize_dirent_tail(t, blocksize);
2202         }
2203
2204         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2205 out:
2206         ext4_fname_free_filename(&fname);
2207         brelse(bh);
2208         if (retval == 0)
2209                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2210         return retval;
2211 }
2212
2213 /*
2214  * Returns 0 for success, or a negative error value
2215  */
2216 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2217                              struct inode *dir, struct inode *inode)
2218 {
2219         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2220         struct dx_entry *entries, *at;
2221         struct buffer_head *bh;
2222         struct super_block *sb = dir->i_sb;
2223         struct ext4_dir_entry_2 *de;
2224         int restart;
2225         int err;
2226
2227 again:
2228         restart = 0;
2229         frame = dx_probe(fname, dir, NULL, frames);
2230         if (IS_ERR(frame))
2231                 return PTR_ERR(frame);
2232         entries = frame->entries;
2233         at = frame->at;
2234         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2235         if (IS_ERR(bh)) {
2236                 err = PTR_ERR(bh);
2237                 bh = NULL;
2238                 goto cleanup;
2239         }
2240
2241         BUFFER_TRACE(bh, "get_write_access");
2242         err = ext4_journal_get_write_access(handle, bh);
2243         if (err)
2244                 goto journal_error;
2245
2246         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2247         if (err != -ENOSPC)
2248                 goto cleanup;
2249
2250         err = 0;
2251         /* Block full, should compress but for now just split */
2252         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2253                        dx_get_count(entries), dx_get_limit(entries)));
2254         /* Need to split index? */
2255         if (dx_get_count(entries) == dx_get_limit(entries)) {
2256                 ext4_lblk_t newblock;
2257                 int levels = frame - frames + 1;
2258                 unsigned int icount;
2259                 int add_level = 1;
2260                 struct dx_entry *entries2;
2261                 struct dx_node *node2;
2262                 struct buffer_head *bh2;
2263
2264                 while (frame > frames) {
2265                         if (dx_get_count((frame - 1)->entries) <
2266                             dx_get_limit((frame - 1)->entries)) {
2267                                 add_level = 0;
2268                                 break;
2269                         }
2270                         frame--; /* split higher index block */
2271                         at = frame->at;
2272                         entries = frame->entries;
2273                         restart = 1;
2274                 }
2275                 if (add_level && levels == ext4_dir_htree_level(sb)) {
2276                         ext4_warning(sb, "Directory (ino: %lu) index full, "
2277                                          "reach max htree level :%d",
2278                                          dir->i_ino, levels);
2279                         if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2280                                 ext4_warning(sb, "Large directory feature is "
2281                                                  "not enabled on this "
2282                                                  "filesystem");
2283                         }
2284                         err = -ENOSPC;
2285                         goto cleanup;
2286                 }
2287                 icount = dx_get_count(entries);
2288                 bh2 = ext4_append(handle, dir, &newblock);
2289                 if (IS_ERR(bh2)) {
2290                         err = PTR_ERR(bh2);
2291                         goto cleanup;
2292                 }
2293                 node2 = (struct dx_node *)(bh2->b_data);
2294                 entries2 = node2->entries;
2295                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2296                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2297                                                            sb->s_blocksize);
2298                 BUFFER_TRACE(frame->bh, "get_write_access");
2299                 err = ext4_journal_get_write_access(handle, frame->bh);
2300                 if (err)
2301                         goto journal_error;
2302                 if (!add_level) {
2303                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2304                         unsigned hash2 = dx_get_hash(entries + icount1);
2305                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2306                                        icount1, icount2));
2307
2308                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2309                         err = ext4_journal_get_write_access(handle,
2310                                                              (frame - 1)->bh);
2311                         if (err)
2312                                 goto journal_error;
2313
2314                         memcpy((char *) entries2, (char *) (entries + icount1),
2315                                icount2 * sizeof(struct dx_entry));
2316                         dx_set_count(entries, icount1);
2317                         dx_set_count(entries2, icount2);
2318                         dx_set_limit(entries2, dx_node_limit(dir));
2319
2320                         /* Which index block gets the new entry? */
2321                         if (at - entries >= icount1) {
2322                                 frame->at = at = at - entries - icount1 + entries2;
2323                                 frame->entries = entries = entries2;
2324                                 swap(frame->bh, bh2);
2325                         }
2326                         dx_insert_block((frame - 1), hash2, newblock);
2327                         dxtrace(dx_show_index("node", frame->entries));
2328                         dxtrace(dx_show_index("node",
2329                                ((struct dx_node *) bh2->b_data)->entries));
2330                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2331                         if (err)
2332                                 goto journal_error;
2333                         brelse (bh2);
2334                         err = ext4_handle_dirty_dx_node(handle, dir,
2335                                                    (frame - 1)->bh);
2336                         if (err)
2337                                 goto journal_error;
2338                         if (restart) {
2339                                 err = ext4_handle_dirty_dx_node(handle, dir,
2340                                                            frame->bh);
2341                                 goto journal_error;
2342                         }
2343                 } else {
2344                         struct dx_root *dxroot;
2345                         memcpy((char *) entries2, (char *) entries,
2346                                icount * sizeof(struct dx_entry));
2347                         dx_set_limit(entries2, dx_node_limit(dir));
2348
2349                         /* Set up root */
2350                         dx_set_count(entries, 1);
2351                         dx_set_block(entries + 0, newblock);
2352                         dxroot = (struct dx_root *)frames[0].bh->b_data;
2353                         dxroot->info.indirect_levels += 1;
2354                         dxtrace(printk(KERN_DEBUG
2355                                        "Creating %d level index...\n",
2356                                        dxroot->info.indirect_levels));
2357                         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2358                         if (err)
2359                                 goto journal_error;
2360                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2361                         brelse(bh2);
2362                         restart = 1;
2363                         goto journal_error;
2364                 }
2365         }
2366         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2367         if (IS_ERR(de)) {
2368                 err = PTR_ERR(de);
2369                 goto cleanup;
2370         }
2371         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2372         goto cleanup;
2373
2374 journal_error:
2375         ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2376 cleanup:
2377         brelse(bh);
2378         dx_release(frames);
2379         /* @restart is true means htree-path has been changed, we need to
2380          * repeat dx_probe() to find out valid htree-path
2381          */
2382         if (restart && err == 0)
2383                 goto again;
2384         return err;
2385 }
2386
2387 /*
2388  * ext4_generic_delete_entry deletes a directory entry by merging it
2389  * with the previous entry
2390  */
2391 int ext4_generic_delete_entry(handle_t *handle,
2392                               struct inode *dir,
2393                               struct ext4_dir_entry_2 *de_del,
2394                               struct buffer_head *bh,
2395                               void *entry_buf,
2396                               int buf_size,
2397                               int csum_size)
2398 {
2399         struct ext4_dir_entry_2 *de, *pde;
2400         unsigned int blocksize = dir->i_sb->s_blocksize;
2401         int i;
2402
2403         i = 0;
2404         pde = NULL;
2405         de = (struct ext4_dir_entry_2 *)entry_buf;
2406         while (i < buf_size - csum_size) {
2407                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2408                                          bh->b_data, bh->b_size, i))
2409                         return -EFSCORRUPTED;
2410                 if (de == de_del)  {
2411                         if (pde)
2412                                 pde->rec_len = ext4_rec_len_to_disk(
2413                                         ext4_rec_len_from_disk(pde->rec_len,
2414                                                                blocksize) +
2415                                         ext4_rec_len_from_disk(de->rec_len,
2416                                                                blocksize),
2417                                         blocksize);
2418                         else
2419                                 de->inode = 0;
2420                         inode_inc_iversion(dir);
2421                         return 0;
2422                 }
2423                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2424                 pde = de;
2425                 de = ext4_next_entry(de, blocksize);
2426         }
2427         return -ENOENT;
2428 }
2429
2430 static int ext4_delete_entry(handle_t *handle,
2431                              struct inode *dir,
2432                              struct ext4_dir_entry_2 *de_del,
2433                              struct buffer_head *bh)
2434 {
2435         int err, csum_size = 0;
2436
2437         if (ext4_has_inline_data(dir)) {
2438                 int has_inline_data = 1;
2439                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2440                                                &has_inline_data);
2441                 if (has_inline_data)
2442                         return err;
2443         }
2444
2445         if (ext4_has_metadata_csum(dir->i_sb))
2446                 csum_size = sizeof(struct ext4_dir_entry_tail);
2447
2448         BUFFER_TRACE(bh, "get_write_access");
2449         err = ext4_journal_get_write_access(handle, bh);
2450         if (unlikely(err))
2451                 goto out;
2452
2453         err = ext4_generic_delete_entry(handle, dir, de_del,
2454                                         bh, bh->b_data,
2455                                         dir->i_sb->s_blocksize, csum_size);
2456         if (err)
2457                 goto out;
2458
2459         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2460         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2461         if (unlikely(err))
2462                 goto out;
2463
2464         return 0;
2465 out:
2466         if (err != -ENOENT)
2467                 ext4_std_error(dir->i_sb, err);
2468         return err;
2469 }
2470
2471 /*
2472  * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2473  * since this indicates that nlinks count was previously 1 to avoid overflowing
2474  * the 16-bit i_links_count field on disk.  Directories with i_nlink == 1 mean
2475  * that subdirectory link counts are not being maintained accurately.
2476  *
2477  * The caller has already checked for i_nlink overflow in case the DIR_LINK
2478  * feature is not enabled and returned -EMLINK.  The is_dx() check is a proxy
2479  * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2480  * on regular files) and to avoid creating huge/slow non-HTREE directories.
2481  */
2482 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2483 {
2484         inc_nlink(inode);
2485         if (is_dx(inode) &&
2486             (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2487                 set_nlink(inode, 1);
2488 }
2489
2490 /*
2491  * If a directory had nlink == 1, then we should let it be 1. This indicates
2492  * directory has >EXT4_LINK_MAX subdirs.
2493  */
2494 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2495 {
2496         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2497                 drop_nlink(inode);
2498 }
2499
2500
2501 static int ext4_add_nondir(handle_t *handle,
2502                 struct dentry *dentry, struct inode *inode)
2503 {
2504         int err = ext4_add_entry(handle, dentry, inode);
2505         if (!err) {
2506                 ext4_mark_inode_dirty(handle, inode);
2507                 d_instantiate_new(dentry, inode);
2508                 return 0;
2509         }
2510         drop_nlink(inode);
2511         unlock_new_inode(inode);
2512         iput(inode);
2513         return err;
2514 }
2515
2516 /*
2517  * By the time this is called, we already have created
2518  * the directory cache entry for the new file, but it
2519  * is so far negative - it has no inode.
2520  *
2521  * If the create succeeds, we fill in the inode information
2522  * with d_instantiate().
2523  */
2524 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2525                        bool excl)
2526 {
2527         handle_t *handle;
2528         struct inode *inode;
2529         int err, credits, retries = 0;
2530
2531         err = dquot_initialize(dir);
2532         if (err)
2533                 return err;
2534
2535         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2536                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2537 retry:
2538         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2539                                             NULL, EXT4_HT_DIR, credits);
2540         handle = ext4_journal_current_handle();
2541         err = PTR_ERR(inode);
2542         if (!IS_ERR(inode)) {
2543                 inode->i_op = &ext4_file_inode_operations;
2544                 inode->i_fop = &ext4_file_operations;
2545                 ext4_set_aops(inode);
2546                 err = ext4_add_nondir(handle, dentry, inode);
2547                 if (!err && IS_DIRSYNC(dir))
2548                         ext4_handle_sync(handle);
2549         }
2550         if (handle)
2551                 ext4_journal_stop(handle);
2552         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2553                 goto retry;
2554         return err;
2555 }
2556
2557 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2558                       umode_t mode, dev_t rdev)
2559 {
2560         handle_t *handle;
2561         struct inode *inode;
2562         int err, credits, retries = 0;
2563
2564         err = dquot_initialize(dir);
2565         if (err)
2566                 return err;
2567
2568         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2569                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2570 retry:
2571         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2572                                             NULL, EXT4_HT_DIR, credits);
2573         handle = ext4_journal_current_handle();
2574         err = PTR_ERR(inode);
2575         if (!IS_ERR(inode)) {
2576                 init_special_inode(inode, inode->i_mode, rdev);
2577                 inode->i_op = &ext4_special_inode_operations;
2578                 err = ext4_add_nondir(handle, dentry, inode);
2579                 if (!err && IS_DIRSYNC(dir))
2580                         ext4_handle_sync(handle);
2581         }
2582         if (handle)
2583                 ext4_journal_stop(handle);
2584         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2585                 goto retry;
2586         return err;
2587 }
2588
2589 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2590 {
2591         handle_t *handle;
2592         struct inode *inode;
2593         int err, retries = 0;
2594
2595         err = dquot_initialize(dir);
2596         if (err)
2597                 return err;
2598
2599 retry:
2600         inode = ext4_new_inode_start_handle(dir, mode,
2601                                             NULL, 0, NULL,
2602                                             EXT4_HT_DIR,
2603                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2604                           4 + EXT4_XATTR_TRANS_BLOCKS);
2605         handle = ext4_journal_current_handle();
2606         err = PTR_ERR(inode);
2607         if (!IS_ERR(inode)) {
2608                 inode->i_op = &ext4_file_inode_operations;
2609                 inode->i_fop = &ext4_file_operations;
2610                 ext4_set_aops(inode);
2611                 d_tmpfile(dentry, inode);
2612                 err = ext4_orphan_add(handle, inode);
2613                 if (err)
2614                         goto err_unlock_inode;
2615                 mark_inode_dirty(inode);
2616                 unlock_new_inode(inode);
2617         }
2618         if (handle)
2619                 ext4_journal_stop(handle);
2620         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2621                 goto retry;
2622         return err;
2623 err_unlock_inode:
2624         ext4_journal_stop(handle);
2625         unlock_new_inode(inode);
2626         return err;
2627 }
2628
2629 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2630                           struct ext4_dir_entry_2 *de,
2631                           int blocksize, int csum_size,
2632                           unsigned int parent_ino, int dotdot_real_len)
2633 {
2634         de->inode = cpu_to_le32(inode->i_ino);
2635         de->name_len = 1;
2636         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2637                                            blocksize);
2638         strcpy(de->name, ".");
2639         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2640
2641         de = ext4_next_entry(de, blocksize);
2642         de->inode = cpu_to_le32(parent_ino);
2643         de->name_len = 2;
2644         if (!dotdot_real_len)
2645                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2646                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2647                                         blocksize);
2648         else
2649                 de->rec_len = ext4_rec_len_to_disk(
2650                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2651         strcpy(de->name, "..");
2652         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2653
2654         return ext4_next_entry(de, blocksize);
2655 }
2656
2657 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2658                              struct inode *inode)
2659 {
2660         struct buffer_head *dir_block = NULL;
2661         struct ext4_dir_entry_2 *de;
2662         struct ext4_dir_entry_tail *t;
2663         ext4_lblk_t block = 0;
2664         unsigned int blocksize = dir->i_sb->s_blocksize;
2665         int csum_size = 0;
2666         int err;
2667
2668         if (ext4_has_metadata_csum(dir->i_sb))
2669                 csum_size = sizeof(struct ext4_dir_entry_tail);
2670
2671         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2672                 err = ext4_try_create_inline_dir(handle, dir, inode);
2673                 if (err < 0 && err != -ENOSPC)
2674                         goto out;
2675                 if (!err)
2676                         goto out;
2677         }
2678
2679         inode->i_size = 0;
2680         dir_block = ext4_append(handle, inode, &block);
2681         if (IS_ERR(dir_block))
2682                 return PTR_ERR(dir_block);
2683         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2684         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2685         set_nlink(inode, 2);
2686         if (csum_size) {
2687                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2688                 initialize_dirent_tail(t, blocksize);
2689         }
2690
2691         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2692         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2693         if (err)
2694                 goto out;
2695         set_buffer_verified(dir_block);
2696 out:
2697         brelse(dir_block);
2698         return err;
2699 }
2700
2701 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2702 {
2703         handle_t *handle;
2704         struct inode *inode;
2705         int err, credits, retries = 0;
2706
2707         if (EXT4_DIR_LINK_MAX(dir))
2708                 return -EMLINK;
2709
2710         err = dquot_initialize(dir);
2711         if (err)
2712                 return err;
2713
2714         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2715                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2716 retry:
2717         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2718                                             &dentry->d_name,
2719                                             0, NULL, EXT4_HT_DIR, credits);
2720         handle = ext4_journal_current_handle();
2721         err = PTR_ERR(inode);
2722         if (IS_ERR(inode))
2723                 goto out_stop;
2724
2725         inode->i_op = &ext4_dir_inode_operations;
2726         inode->i_fop = &ext4_dir_operations;
2727         err = ext4_init_new_dir(handle, dir, inode);
2728         if (err)
2729                 goto out_clear_inode;
2730         err = ext4_mark_inode_dirty(handle, inode);
2731         if (!err)
2732                 err = ext4_add_entry(handle, dentry, inode);
2733         if (err) {
2734 out_clear_inode:
2735                 clear_nlink(inode);
2736                 unlock_new_inode(inode);
2737                 ext4_mark_inode_dirty(handle, inode);
2738                 iput(inode);
2739                 goto out_stop;
2740         }
2741         ext4_inc_count(handle, dir);
2742         ext4_update_dx_flag(dir);
2743         err = ext4_mark_inode_dirty(handle, dir);
2744         if (err)
2745                 goto out_clear_inode;
2746         d_instantiate_new(dentry, inode);
2747         if (IS_DIRSYNC(dir))
2748                 ext4_handle_sync(handle);
2749
2750 out_stop:
2751         if (handle)
2752                 ext4_journal_stop(handle);
2753         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2754                 goto retry;
2755         return err;
2756 }
2757
2758 /*
2759  * routine to check that the specified directory is empty (for rmdir)
2760  */
2761 bool ext4_empty_dir(struct inode *inode)
2762 {
2763         unsigned int offset;
2764         struct buffer_head *bh;
2765         struct ext4_dir_entry_2 *de, *de1;
2766         struct super_block *sb;
2767
2768         if (ext4_has_inline_data(inode)) {
2769                 int has_inline_data = 1;
2770                 int ret;
2771
2772                 ret = empty_inline_dir(inode, &has_inline_data);
2773                 if (has_inline_data)
2774                         return ret;
2775         }
2776
2777         sb = inode->i_sb;
2778         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2779                 EXT4_ERROR_INODE(inode, "invalid size");
2780                 return true;
2781         }
2782         bh = ext4_read_dirblock(inode, 0, EITHER);
2783         if (IS_ERR(bh))
2784                 return true;
2785
2786         de = (struct ext4_dir_entry_2 *) bh->b_data;
2787         de1 = ext4_next_entry(de, sb->s_blocksize);
2788         if (le32_to_cpu(de->inode) != inode->i_ino ||
2789                         le32_to_cpu(de1->inode) == 0 ||
2790                         strcmp(".", de->name) || strcmp("..", de1->name)) {
2791                 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2792                 brelse(bh);
2793                 return true;
2794         }
2795         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2796                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2797         de = ext4_next_entry(de1, sb->s_blocksize);
2798         while (offset < inode->i_size) {
2799                 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2800                         unsigned int lblock;
2801                         brelse(bh);
2802                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2803                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2804                         if (IS_ERR(bh))
2805                                 return true;
2806                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2807                 }
2808                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2809                                          bh->b_data, bh->b_size, offset)) {
2810                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2811                                                          sb->s_blocksize);
2812                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2813                         continue;
2814                 }
2815                 if (le32_to_cpu(de->inode)) {
2816                         brelse(bh);
2817                         return false;
2818                 }
2819                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2820                 de = ext4_next_entry(de, sb->s_blocksize);
2821         }
2822         brelse(bh);
2823         return true;
2824 }
2825
2826 /*
2827  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2828  * such inodes, starting at the superblock, in case we crash before the
2829  * file is closed/deleted, or in case the inode truncate spans multiple
2830  * transactions and the last transaction is not recovered after a crash.
2831  *
2832  * At filesystem recovery time, we walk this list deleting unlinked
2833  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2834  *
2835  * Orphan list manipulation functions must be called under i_mutex unless
2836  * we are just creating the inode or deleting it.
2837  */
2838 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2839 {
2840         struct super_block *sb = inode->i_sb;
2841         struct ext4_sb_info *sbi = EXT4_SB(sb);
2842         struct ext4_iloc iloc;
2843         int err = 0, rc;
2844         bool dirty = false;
2845
2846         if (!sbi->s_journal || is_bad_inode(inode))
2847                 return 0;
2848
2849         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2850                      !inode_is_locked(inode));
2851         /*
2852          * Exit early if inode already is on orphan list. This is a big speedup
2853          * since we don't have to contend on the global s_orphan_lock.
2854          */
2855         if (!list_empty(&EXT4_I(inode)->i_orphan))
2856                 return 0;
2857
2858         /*
2859          * Orphan handling is only valid for files with data blocks
2860          * being truncated, or files being unlinked. Note that we either
2861          * hold i_mutex, or the inode can not be referenced from outside,
2862          * so i_nlink should not be bumped due to race
2863          */
2864         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2865                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2866
2867         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2868         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2869         if (err)
2870                 goto out;
2871
2872         err = ext4_reserve_inode_write(handle, inode, &iloc);
2873         if (err)
2874                 goto out;
2875
2876         mutex_lock(&sbi->s_orphan_lock);
2877         /*
2878          * Due to previous errors inode may be already a part of on-disk
2879          * orphan list. If so skip on-disk list modification.
2880          */
2881         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2882             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2883                 /* Insert this inode at the head of the on-disk orphan list */
2884                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2885                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2886                 dirty = true;
2887         }
2888         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2889         mutex_unlock(&sbi->s_orphan_lock);
2890
2891         if (dirty) {
2892                 err = ext4_handle_dirty_super(handle, sb);
2893                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2894                 if (!err)
2895                         err = rc;
2896                 if (err) {
2897                         /*
2898                          * We have to remove inode from in-memory list if
2899                          * addition to on disk orphan list failed. Stray orphan
2900                          * list entries can cause panics at unmount time.
2901                          */
2902                         mutex_lock(&sbi->s_orphan_lock);
2903                         list_del_init(&EXT4_I(inode)->i_orphan);
2904                         mutex_unlock(&sbi->s_orphan_lock);
2905                 }
2906         } else
2907                 brelse(iloc.bh);
2908
2909         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2910         jbd_debug(4, "orphan inode %lu will point to %d\n",
2911                         inode->i_ino, NEXT_ORPHAN(inode));
2912 out:
2913         ext4_std_error(sb, err);
2914         return err;
2915 }
2916
2917 /*
2918  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2919  * of such inodes stored on disk, because it is finally being cleaned up.
2920  */
2921 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2922 {
2923         struct list_head *prev;
2924         struct ext4_inode_info *ei = EXT4_I(inode);
2925         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2926         __u32 ino_next;
2927         struct ext4_iloc iloc;
2928         int err = 0;
2929
2930         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2931                 return 0;
2932
2933         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2934                      !inode_is_locked(inode));
2935         /* Do this quick check before taking global s_orphan_lock. */
2936         if (list_empty(&ei->i_orphan))
2937                 return 0;
2938
2939         if (handle) {
2940                 /* Grab inode buffer early before taking global s_orphan_lock */
2941                 err = ext4_reserve_inode_write(handle, inode, &iloc);
2942         }
2943
2944         mutex_lock(&sbi->s_orphan_lock);
2945         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2946
2947         prev = ei->i_orphan.prev;
2948         list_del_init(&ei->i_orphan);
2949
2950         /* If we're on an error path, we may not have a valid
2951          * transaction handle with which to update the orphan list on
2952          * disk, but we still need to remove the inode from the linked
2953          * list in memory. */
2954         if (!handle || err) {
2955                 mutex_unlock(&sbi->s_orphan_lock);
2956                 goto out_err;
2957         }
2958
2959         ino_next = NEXT_ORPHAN(inode);
2960         if (prev == &sbi->s_orphan) {
2961                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2962                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2963                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2964                 if (err) {
2965                         mutex_unlock(&sbi->s_orphan_lock);
2966                         goto out_brelse;
2967                 }
2968                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2969                 mutex_unlock(&sbi->s_orphan_lock);
2970                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2971         } else {
2972                 struct ext4_iloc iloc2;
2973                 struct inode *i_prev =
2974                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2975
2976                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2977                           i_prev->i_ino, ino_next);
2978                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2979                 if (err) {
2980                         mutex_unlock(&sbi->s_orphan_lock);
2981                         goto out_brelse;
2982                 }
2983                 NEXT_ORPHAN(i_prev) = ino_next;
2984                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2985                 mutex_unlock(&sbi->s_orphan_lock);
2986         }
2987         if (err)
2988                 goto out_brelse;
2989         NEXT_ORPHAN(inode) = 0;
2990         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2991 out_err:
2992         ext4_std_error(inode->i_sb, err);
2993         return err;
2994
2995 out_brelse:
2996         brelse(iloc.bh);
2997         goto out_err;
2998 }
2999
3000 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3001 {
3002         int retval;
3003         struct inode *inode;
3004         struct buffer_head *bh;
3005         struct ext4_dir_entry_2 *de;
3006         handle_t *handle = NULL;
3007
3008         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3009                 return -EIO;
3010
3011         /* Initialize quotas before so that eventual writes go in
3012          * separate transaction */
3013         retval = dquot_initialize(dir);
3014         if (retval)
3015                 return retval;
3016         retval = dquot_initialize(d_inode(dentry));
3017         if (retval)
3018                 return retval;
3019
3020         retval = -ENOENT;
3021         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3022         if (IS_ERR(bh))
3023                 return PTR_ERR(bh);
3024         if (!bh)
3025                 goto end_rmdir;
3026
3027         inode = d_inode(dentry);
3028
3029         retval = -EFSCORRUPTED;
3030         if (le32_to_cpu(de->inode) != inode->i_ino)
3031                 goto end_rmdir;
3032
3033         retval = -ENOTEMPTY;
3034         if (!ext4_empty_dir(inode))
3035                 goto end_rmdir;
3036
3037         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3038                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3039         if (IS_ERR(handle)) {
3040                 retval = PTR_ERR(handle);
3041                 handle = NULL;
3042                 goto end_rmdir;
3043         }
3044
3045         if (IS_DIRSYNC(dir))
3046                 ext4_handle_sync(handle);
3047
3048         retval = ext4_delete_entry(handle, dir, de, bh);
3049         if (retval)
3050                 goto end_rmdir;
3051         if (!EXT4_DIR_LINK_EMPTY(inode))
3052                 ext4_warning_inode(inode,
3053                              "empty directory '%.*s' has too many links (%u)",
3054                              dentry->d_name.len, dentry->d_name.name,
3055                              inode->i_nlink);
3056         inode_inc_iversion(inode);
3057         clear_nlink(inode);
3058         /* There's no need to set i_disksize: the fact that i_nlink is
3059          * zero will ensure that the right thing happens during any
3060          * recovery. */
3061         inode->i_size = 0;
3062         ext4_orphan_add(handle, inode);
3063         inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
3064         ext4_mark_inode_dirty(handle, inode);
3065         ext4_dec_count(handle, dir);
3066         ext4_update_dx_flag(dir);
3067         ext4_mark_inode_dirty(handle, dir);
3068
3069 #ifdef CONFIG_UNICODE
3070         /* VFS negative dentries are incompatible with Encoding and
3071          * Case-insensitiveness. Eventually we'll want avoid
3072          * invalidating the dentries here, alongside with returning the
3073          * negative dentries at ext4_lookup(), when it is better
3074          * supported by the VFS for the CI case.
3075          */
3076         if (IS_CASEFOLDED(dir))
3077                 d_invalidate(dentry);
3078 #endif
3079
3080 end_rmdir:
3081         brelse(bh);
3082         if (handle)
3083                 ext4_journal_stop(handle);
3084         return retval;
3085 }
3086
3087 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3088 {
3089         int retval;
3090         struct inode *inode;
3091         struct buffer_head *bh;
3092         struct ext4_dir_entry_2 *de;
3093         handle_t *handle = NULL;
3094
3095         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3096                 return -EIO;
3097
3098         trace_ext4_unlink_enter(dir, dentry);
3099         /* Initialize quotas before so that eventual writes go
3100          * in separate transaction */
3101         retval = dquot_initialize(dir);
3102         if (retval)
3103                 return retval;
3104         retval = dquot_initialize(d_inode(dentry));
3105         if (retval)
3106                 return retval;
3107
3108         retval = -ENOENT;
3109         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3110         if (IS_ERR(bh))
3111                 return PTR_ERR(bh);
3112         if (!bh)
3113                 goto end_unlink;
3114
3115         inode = d_inode(dentry);
3116
3117         retval = -EFSCORRUPTED;
3118         if (le32_to_cpu(de->inode) != inode->i_ino)
3119                 goto end_unlink;
3120
3121         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3122                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3123         if (IS_ERR(handle)) {
3124                 retval = PTR_ERR(handle);
3125                 handle = NULL;
3126                 goto end_unlink;
3127         }
3128
3129         if (IS_DIRSYNC(dir))
3130                 ext4_handle_sync(handle);
3131
3132         if (inode->i_nlink == 0) {
3133                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3134                                    dentry->d_name.len, dentry->d_name.name);
3135                 set_nlink(inode, 1);
3136         }
3137         retval = ext4_delete_entry(handle, dir, de, bh);
3138         if (retval)
3139                 goto end_unlink;
3140         dir->i_ctime = dir->i_mtime = current_time(dir);
3141         ext4_update_dx_flag(dir);
3142         ext4_mark_inode_dirty(handle, dir);
3143         drop_nlink(inode);
3144         if (!inode->i_nlink)
3145                 ext4_orphan_add(handle, inode);
3146         inode->i_ctime = current_time(inode);
3147         ext4_mark_inode_dirty(handle, inode);
3148
3149 #ifdef CONFIG_UNICODE
3150         /* VFS negative dentries are incompatible with Encoding and
3151          * Case-insensitiveness. Eventually we'll want avoid
3152          * invalidating the dentries here, alongside with returning the
3153          * negative dentries at ext4_lookup(), when it is  better
3154          * supported by the VFS for the CI case.
3155          */
3156         if (IS_CASEFOLDED(dir))
3157                 d_invalidate(dentry);
3158 #endif
3159
3160 end_unlink:
3161         brelse(bh);
3162         if (handle)
3163                 ext4_journal_stop(handle);
3164         trace_ext4_unlink_exit(dentry, retval);
3165         return retval;
3166 }
3167
3168 static int ext4_symlink(struct inode *dir,
3169                         struct dentry *dentry, const char *symname)
3170 {
3171         handle_t *handle;
3172         struct inode *inode;
3173         int err, len = strlen(symname);
3174         int credits;
3175         struct fscrypt_str disk_link;
3176
3177         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3178                 return -EIO;
3179
3180         err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3181                                       &disk_link);
3182         if (err)
3183                 return err;
3184
3185         err = dquot_initialize(dir);
3186         if (err)
3187                 return err;
3188
3189         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3190                 /*
3191                  * For non-fast symlinks, we just allocate inode and put it on
3192                  * orphan list in the first transaction => we need bitmap,
3193                  * group descriptor, sb, inode block, quota blocks, and
3194                  * possibly selinux xattr blocks.
3195                  */
3196                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3197                           EXT4_XATTR_TRANS_BLOCKS;
3198         } else {
3199                 /*
3200                  * Fast symlink. We have to add entry to directory
3201                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3202                  * allocate new inode (bitmap, group descriptor, inode block,
3203                  * quota blocks, sb is already counted in previous macros).
3204                  */
3205                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3206                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3207         }
3208
3209         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3210                                             &dentry->d_name, 0, NULL,
3211                                             EXT4_HT_DIR, credits);
3212         handle = ext4_journal_current_handle();
3213         if (IS_ERR(inode)) {
3214                 if (handle)
3215                         ext4_journal_stop(handle);
3216                 return PTR_ERR(inode);
3217         }
3218
3219         if (IS_ENCRYPTED(inode)) {
3220                 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3221                 if (err)
3222                         goto err_drop_inode;
3223                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3224         }
3225
3226         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3227                 if (!IS_ENCRYPTED(inode))
3228                         inode->i_op = &ext4_symlink_inode_operations;
3229                 inode_nohighmem(inode);
3230                 ext4_set_aops(inode);
3231                 /*
3232                  * We cannot call page_symlink() with transaction started
3233                  * because it calls into ext4_write_begin() which can wait
3234                  * for transaction commit if we are running out of space
3235                  * and thus we deadlock. So we have to stop transaction now
3236                  * and restart it when symlink contents is written.
3237                  *
3238                  * To keep fs consistent in case of crash, we have to put inode
3239                  * to orphan list in the mean time.
3240                  */
3241                 drop_nlink(inode);
3242                 err = ext4_orphan_add(handle, inode);
3243                 ext4_journal_stop(handle);
3244                 handle = NULL;
3245                 if (err)
3246                         goto err_drop_inode;
3247                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3248                 if (err)
3249                         goto err_drop_inode;
3250                 /*
3251                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3252                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3253                  */
3254                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3255                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3256                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3257                 if (IS_ERR(handle)) {
3258                         err = PTR_ERR(handle);
3259                         handle = NULL;
3260                         goto err_drop_inode;
3261                 }
3262                 set_nlink(inode, 1);
3263                 err = ext4_orphan_del(handle, inode);
3264                 if (err)
3265                         goto err_drop_inode;
3266         } else {
3267                 /* clear the extent format for fast symlink */
3268                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3269                 if (!IS_ENCRYPTED(inode)) {
3270                         inode->i_op = &ext4_fast_symlink_inode_operations;
3271                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3272                 }
3273                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3274                        disk_link.len);
3275                 inode->i_size = disk_link.len - 1;
3276         }
3277         EXT4_I(inode)->i_disksize = inode->i_size;
3278         err = ext4_add_nondir(handle, dentry, inode);
3279         if (!err && IS_DIRSYNC(dir))
3280                 ext4_handle_sync(handle);
3281
3282         if (handle)
3283                 ext4_journal_stop(handle);
3284         goto out_free_encrypted_link;
3285
3286 err_drop_inode:
3287         if (handle)
3288                 ext4_journal_stop(handle);
3289         clear_nlink(inode);
3290         unlock_new_inode(inode);
3291         iput(inode);
3292 out_free_encrypted_link:
3293         if (disk_link.name != (unsigned char *)symname)
3294                 kfree(disk_link.name);
3295         return err;
3296 }
3297
3298 static int ext4_link(struct dentry *old_dentry,
3299                      struct inode *dir, struct dentry *dentry)
3300 {
3301         handle_t *handle;
3302         struct inode *inode = d_inode(old_dentry);
3303         int err, retries = 0;
3304
3305         if (inode->i_nlink >= EXT4_LINK_MAX)
3306                 return -EMLINK;
3307
3308         err = fscrypt_prepare_link(old_dentry, dir, dentry);
3309         if (err)
3310                 return err;
3311
3312         if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3313             (!projid_eq(EXT4_I(dir)->i_projid,
3314                         EXT4_I(old_dentry->d_inode)->i_projid)))
3315                 return -EXDEV;
3316
3317         err = dquot_initialize(dir);
3318         if (err)
3319                 return err;
3320
3321 retry:
3322         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3323                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3324                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3325         if (IS_ERR(handle))
3326                 return PTR_ERR(handle);
3327
3328         if (IS_DIRSYNC(dir))
3329                 ext4_handle_sync(handle);
3330
3331         inode->i_ctime = current_time(inode);
3332         ext4_inc_count(handle, inode);
3333         ihold(inode);
3334
3335         err = ext4_add_entry(handle, dentry, inode);
3336         if (!err) {
3337                 ext4_mark_inode_dirty(handle, inode);
3338                 /* this can happen only for tmpfile being
3339                  * linked the first time
3340                  */
3341                 if (inode->i_nlink == 1)
3342                         ext4_orphan_del(handle, inode);
3343                 d_instantiate(dentry, inode);
3344         } else {
3345                 drop_nlink(inode);
3346                 iput(inode);
3347         }
3348         ext4_journal_stop(handle);
3349         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3350                 goto retry;
3351         return err;
3352 }
3353
3354
3355 /*
3356  * Try to find buffer head where contains the parent block.
3357  * It should be the inode block if it is inlined or the 1st block
3358  * if it is a normal dir.
3359  */
3360 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3361                                         struct inode *inode,
3362                                         int *retval,
3363                                         struct ext4_dir_entry_2 **parent_de,
3364                                         int *inlined)
3365 {
3366         struct buffer_head *bh;
3367
3368         if (!ext4_has_inline_data(inode)) {
3369                 bh = ext4_read_dirblock(inode, 0, EITHER);
3370                 if (IS_ERR(bh)) {
3371                         *retval = PTR_ERR(bh);
3372                         return NULL;
3373                 }
3374                 *parent_de = ext4_next_entry(
3375                                         (struct ext4_dir_entry_2 *)bh->b_data,
3376                                         inode->i_sb->s_blocksize);
3377                 return bh;
3378         }
3379
3380         *inlined = 1;
3381         return ext4_get_first_inline_block(inode, parent_de, retval);
3382 }
3383
3384 struct ext4_renament {
3385         struct inode *dir;
3386         struct dentry *dentry;
3387         struct inode *inode;
3388         bool is_dir;
3389         int dir_nlink_delta;
3390
3391         /* entry for "dentry" */
3392         struct buffer_head *bh;
3393         struct ext4_dir_entry_2 *de;
3394         int inlined;
3395
3396         /* entry for ".." in inode if it's a directory */
3397         struct buffer_head *dir_bh;
3398         struct ext4_dir_entry_2 *parent_de;
3399         int dir_inlined;
3400 };
3401
3402 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3403 {
3404         int retval;
3405
3406         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3407                                               &retval, &ent->parent_de,
3408                                               &ent->dir_inlined);
3409         if (!ent->dir_bh)
3410                 return retval;
3411         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3412                 return -EFSCORRUPTED;
3413         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3414         return ext4_journal_get_write_access(handle, ent->dir_bh);
3415 }
3416
3417 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3418                                   unsigned dir_ino)
3419 {
3420         int retval;
3421
3422         ent->parent_de->inode = cpu_to_le32(dir_ino);
3423         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3424         if (!ent->dir_inlined) {
3425                 if (is_dx(ent->inode)) {
3426                         retval = ext4_handle_dirty_dx_node(handle,
3427                                                            ent->inode,
3428                                                            ent->dir_bh);
3429                 } else {
3430                         retval = ext4_handle_dirty_dirent_node(handle,
3431                                                                ent->inode,
3432                                                                ent->dir_bh);
3433                 }
3434         } else {
3435                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3436         }
3437         if (retval) {
3438                 ext4_std_error(ent->dir->i_sb, retval);
3439                 return retval;
3440         }
3441         return 0;
3442 }
3443
3444 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3445                        unsigned ino, unsigned file_type)
3446 {
3447         int retval;
3448
3449         BUFFER_TRACE(ent->bh, "get write access");
3450         retval = ext4_journal_get_write_access(handle, ent->bh);
3451         if (retval)
3452                 return retval;
3453         ent->de->inode = cpu_to_le32(ino);
3454         if (ext4_has_feature_filetype(ent->dir->i_sb))
3455                 ent->de->file_type = file_type;
3456         inode_inc_iversion(ent->dir);
3457         ent->dir->i_ctime = ent->dir->i_mtime =
3458                 current_time(ent->dir);
3459         ext4_mark_inode_dirty(handle, ent->dir);
3460         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3461         if (!ent->inlined) {
3462                 retval = ext4_handle_dirty_dirent_node(handle,
3463                                                        ent->dir, ent->bh);
3464                 if (unlikely(retval)) {
3465                         ext4_std_error(ent->dir->i_sb, retval);
3466                         return retval;
3467                 }
3468         }
3469         brelse(ent->bh);
3470         ent->bh = NULL;
3471
3472         return 0;
3473 }
3474
3475 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3476                                   const struct qstr *d_name)
3477 {
3478         int retval = -ENOENT;
3479         struct buffer_head *bh;
3480         struct ext4_dir_entry_2 *de;
3481
3482         bh = ext4_find_entry(dir, d_name, &de, NULL);
3483         if (IS_ERR(bh))
3484                 return PTR_ERR(bh);
3485         if (bh) {
3486                 retval = ext4_delete_entry(handle, dir, de, bh);
3487                 brelse(bh);
3488         }
3489         return retval;
3490 }
3491
3492 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3493                                int force_reread)
3494 {
3495         int retval;
3496         /*
3497          * ent->de could have moved from under us during htree split, so make
3498          * sure that we are deleting the right entry.  We might also be pointing
3499          * to a stale entry in the unused part of ent->bh so just checking inum
3500          * and the name isn't enough.
3501          */
3502         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3503             ent->de->name_len != ent->dentry->d_name.len ||
3504             strncmp(ent->de->name, ent->dentry->d_name.name,
3505                     ent->de->name_len) ||
3506             force_reread) {
3507                 retval = ext4_find_delete_entry(handle, ent->dir,
3508                                                 &ent->dentry->d_name);
3509         } else {
3510                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3511                 if (retval == -ENOENT) {
3512                         retval = ext4_find_delete_entry(handle, ent->dir,
3513                                                         &ent->dentry->d_name);
3514                 }
3515         }
3516
3517         if (retval) {
3518                 ext4_warning_inode(ent->dir,
3519                                    "Deleting old file: nlink %d, error=%d",
3520                                    ent->dir->i_nlink, retval);
3521         }
3522 }
3523
3524 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3525 {
3526         if (ent->dir_nlink_delta) {
3527                 if (ent->dir_nlink_delta == -1)
3528                         ext4_dec_count(handle, ent->dir);
3529                 else
3530                         ext4_inc_count(handle, ent->dir);
3531                 ext4_mark_inode_dirty(handle, ent->dir);
3532         }
3533 }
3534
3535 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3536                                               int credits, handle_t **h)
3537 {
3538         struct inode *wh;
3539         handle_t *handle;
3540         int retries = 0;
3541
3542         /*
3543          * for inode block, sb block, group summaries,
3544          * and inode bitmap
3545          */
3546         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3547                     EXT4_XATTR_TRANS_BLOCKS + 4);
3548 retry:
3549         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3550                                          &ent->dentry->d_name, 0, NULL,
3551                                          EXT4_HT_DIR, credits);
3552
3553         handle = ext4_journal_current_handle();
3554         if (IS_ERR(wh)) {
3555                 if (handle)
3556                         ext4_journal_stop(handle);
3557                 if (PTR_ERR(wh) == -ENOSPC &&
3558                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3559                         goto retry;
3560         } else {
3561                 *h = handle;
3562                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3563                 wh->i_op = &ext4_special_inode_operations;
3564         }
3565         return wh;
3566 }
3567
3568 /*
3569  * Anybody can rename anything with this: the permission checks are left to the
3570  * higher-level routines.
3571  *
3572  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3573  * while new_{dentry,inode) refers to the destination dentry/inode
3574  * This comes from rename(const char *oldpath, const char *newpath)
3575  */
3576 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3577                        struct inode *new_dir, struct dentry *new_dentry,
3578                        unsigned int flags)
3579 {
3580         handle_t *handle = NULL;
3581         struct ext4_renament old = {
3582                 .dir = old_dir,
3583                 .dentry = old_dentry,
3584                 .inode = d_inode(old_dentry),
3585         };
3586         struct ext4_renament new = {
3587                 .dir = new_dir,
3588                 .dentry = new_dentry,
3589                 .inode = d_inode(new_dentry),
3590         };
3591         int force_reread;
3592         int retval;
3593         struct inode *whiteout = NULL;
3594         int credits;
3595         u8 old_file_type;
3596
3597         if (new.inode && new.inode->i_nlink == 0) {
3598                 EXT4_ERROR_INODE(new.inode,
3599                                  "target of rename is already freed");
3600                 return -EFSCORRUPTED;
3601         }
3602
3603         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3604             (!projid_eq(EXT4_I(new_dir)->i_projid,
3605                         EXT4_I(old_dentry->d_inode)->i_projid)))
3606                 return -EXDEV;
3607
3608         retval = dquot_initialize(old.dir);
3609         if (retval)
3610                 return retval;
3611         retval = dquot_initialize(new.dir);
3612         if (retval)
3613                 return retval;
3614
3615         /* Initialize quotas before so that eventual writes go
3616          * in separate transaction */
3617         if (new.inode) {
3618                 retval = dquot_initialize(new.inode);
3619                 if (retval)
3620                         return retval;
3621         }
3622
3623         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3624         if (IS_ERR(old.bh))
3625                 return PTR_ERR(old.bh);
3626         /*
3627          *  Check for inode number is _not_ due to possible IO errors.
3628          *  We might rmdir the source, keep it as pwd of some process
3629          *  and merrily kill the link to whatever was created under the
3630          *  same name. Goodbye sticky bit ;-<
3631          */
3632         retval = -ENOENT;
3633         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3634                 goto end_rename;
3635
3636         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3637                                  &new.de, &new.inlined);
3638         if (IS_ERR(new.bh)) {
3639                 retval = PTR_ERR(new.bh);
3640                 new.bh = NULL;
3641                 goto end_rename;
3642         }
3643         if (new.bh) {
3644                 if (!new.inode) {
3645                         brelse(new.bh);
3646                         new.bh = NULL;
3647                 }
3648         }
3649         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3650                 ext4_alloc_da_blocks(old.inode);
3651
3652         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3653                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3654         if (!(flags & RENAME_WHITEOUT)) {
3655                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3656                 if (IS_ERR(handle)) {
3657                         retval = PTR_ERR(handle);
3658                         handle = NULL;
3659                         goto end_rename;
3660                 }
3661         } else {
3662                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3663                 if (IS_ERR(whiteout)) {
3664                         retval = PTR_ERR(whiteout);
3665                         whiteout = NULL;
3666                         goto end_rename;
3667                 }
3668         }
3669
3670         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3671                 ext4_handle_sync(handle);
3672
3673         if (S_ISDIR(old.inode->i_mode)) {
3674                 if (new.inode) {
3675                         retval = -ENOTEMPTY;
3676                         if (!ext4_empty_dir(new.inode))
3677                                 goto end_rename;
3678                 } else {
3679                         retval = -EMLINK;
3680                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3681                                 goto end_rename;
3682                 }
3683                 retval = ext4_rename_dir_prepare(handle, &old);
3684                 if (retval)
3685                         goto end_rename;
3686         }
3687         /*
3688          * If we're renaming a file within an inline_data dir and adding or
3689          * setting the new dirent causes a conversion from inline_data to
3690          * extents/blockmap, we need to force the dirent delete code to
3691          * re-read the directory, or else we end up trying to delete a dirent
3692          * from what is now the extent tree root (or a block map).
3693          */
3694         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3695                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3696
3697         old_file_type = old.de->file_type;
3698         if (whiteout) {
3699                 /*
3700                  * Do this before adding a new entry, so the old entry is sure
3701                  * to be still pointing to the valid old entry.
3702                  */
3703                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3704                                      EXT4_FT_CHRDEV);
3705                 if (retval)
3706                         goto end_rename;
3707                 ext4_mark_inode_dirty(handle, whiteout);
3708         }
3709         if (!new.bh) {
3710                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3711                 if (retval)
3712                         goto end_rename;
3713         } else {
3714                 retval = ext4_setent(handle, &new,
3715                                      old.inode->i_ino, old_file_type);
3716                 if (retval)
3717                         goto end_rename;
3718         }
3719         if (force_reread)
3720                 force_reread = !ext4_test_inode_flag(new.dir,
3721                                                      EXT4_INODE_INLINE_DATA);
3722
3723         /*
3724          * Like most other Unix systems, set the ctime for inodes on a
3725          * rename.
3726          */
3727         old.inode->i_ctime = current_time(old.inode);
3728         ext4_mark_inode_dirty(handle, old.inode);
3729
3730         if (!whiteout) {
3731                 /*
3732                  * ok, that's it
3733                  */
3734                 ext4_rename_delete(handle, &old, force_reread);
3735         }
3736
3737         if (new.inode) {
3738                 ext4_dec_count(handle, new.inode);
3739                 new.inode->i_ctime = current_time(new.inode);
3740         }
3741         old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
3742         ext4_update_dx_flag(old.dir);
3743         if (old.dir_bh) {
3744                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3745                 if (retval)
3746                         goto end_rename;
3747
3748                 ext4_dec_count(handle, old.dir);
3749                 if (new.inode) {
3750                         /* checked ext4_empty_dir above, can't have another
3751                          * parent, ext4_dec_count() won't work for many-linked
3752                          * dirs */
3753                         clear_nlink(new.inode);
3754                 } else {
3755                         ext4_inc_count(handle, new.dir);
3756                         ext4_update_dx_flag(new.dir);
3757                         ext4_mark_inode_dirty(handle, new.dir);
3758                 }
3759         }
3760         ext4_mark_inode_dirty(handle, old.dir);
3761         if (new.inode) {
3762                 ext4_mark_inode_dirty(handle, new.inode);
3763                 if (!new.inode->i_nlink)
3764                         ext4_orphan_add(handle, new.inode);
3765         }
3766         retval = 0;
3767
3768 end_rename:
3769         brelse(old.dir_bh);
3770         brelse(old.bh);
3771         brelse(new.bh);
3772         if (whiteout) {
3773                 if (retval)
3774                         drop_nlink(whiteout);
3775                 unlock_new_inode(whiteout);
3776                 iput(whiteout);
3777         }
3778         if (handle)
3779                 ext4_journal_stop(handle);
3780         return retval;
3781 }
3782
3783 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3784                              struct inode *new_dir, struct dentry *new_dentry)
3785 {
3786         handle_t *handle = NULL;
3787         struct ext4_renament old = {
3788                 .dir = old_dir,
3789                 .dentry = old_dentry,
3790                 .inode = d_inode(old_dentry),
3791         };
3792         struct ext4_renament new = {
3793                 .dir = new_dir,
3794                 .dentry = new_dentry,
3795                 .inode = d_inode(new_dentry),
3796         };
3797         u8 new_file_type;
3798         int retval;
3799         struct timespec64 ctime;
3800
3801         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3802              !projid_eq(EXT4_I(new_dir)->i_projid,
3803                         EXT4_I(old_dentry->d_inode)->i_projid)) ||
3804             (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3805              !projid_eq(EXT4_I(old_dir)->i_projid,
3806                         EXT4_I(new_dentry->d_inode)->i_projid)))
3807                 return -EXDEV;
3808
3809         retval = dquot_initialize(old.dir);
3810         if (retval)
3811                 return retval;
3812         retval = dquot_initialize(new.dir);
3813         if (retval)
3814                 return retval;
3815
3816         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3817                                  &old.de, &old.inlined);
3818         if (IS_ERR(old.bh))
3819                 return PTR_ERR(old.bh);
3820         /*
3821          *  Check for inode number is _not_ due to possible IO errors.
3822          *  We might rmdir the source, keep it as pwd of some process
3823          *  and merrily kill the link to whatever was created under the
3824          *  same name. Goodbye sticky bit ;-<
3825          */
3826         retval = -ENOENT;
3827         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3828                 goto end_rename;
3829
3830         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3831                                  &new.de, &new.inlined);
3832         if (IS_ERR(new.bh)) {
3833                 retval = PTR_ERR(new.bh);
3834                 new.bh = NULL;
3835                 goto end_rename;
3836         }
3837
3838         /* RENAME_EXCHANGE case: old *and* new must both exist */
3839         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3840                 goto end_rename;
3841
3842         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3843                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3844                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3845         if (IS_ERR(handle)) {
3846                 retval = PTR_ERR(handle);
3847                 handle = NULL;
3848                 goto end_rename;
3849         }
3850
3851         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3852                 ext4_handle_sync(handle);
3853
3854         if (S_ISDIR(old.inode->i_mode)) {
3855                 old.is_dir = true;
3856                 retval = ext4_rename_dir_prepare(handle, &old);
3857                 if (retval)
3858                         goto end_rename;
3859         }
3860         if (S_ISDIR(new.inode->i_mode)) {
3861                 new.is_dir = true;
3862                 retval = ext4_rename_dir_prepare(handle, &new);
3863                 if (retval)
3864                         goto end_rename;
3865         }
3866
3867         /*
3868          * Other than the special case of overwriting a directory, parents'
3869          * nlink only needs to be modified if this is a cross directory rename.
3870          */
3871         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3872                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3873                 new.dir_nlink_delta = -old.dir_nlink_delta;
3874                 retval = -EMLINK;
3875                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3876                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3877                         goto end_rename;
3878         }
3879
3880         new_file_type = new.de->file_type;
3881         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3882         if (retval)
3883                 goto end_rename;
3884
3885         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3886         if (retval)
3887                 goto end_rename;
3888
3889         /*
3890          * Like most other Unix systems, set the ctime for inodes on a
3891          * rename.
3892          */
3893         ctime = current_time(old.inode);
3894         old.inode->i_ctime = ctime;
3895         new.inode->i_ctime = ctime;
3896         ext4_mark_inode_dirty(handle, old.inode);
3897         ext4_mark_inode_dirty(handle, new.inode);
3898
3899         if (old.dir_bh) {
3900                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3901                 if (retval)
3902                         goto end_rename;
3903         }
3904         if (new.dir_bh) {
3905                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3906                 if (retval)
3907                         goto end_rename;
3908         }
3909         ext4_update_dir_count(handle, &old);
3910         ext4_update_dir_count(handle, &new);
3911         retval = 0;
3912
3913 end_rename:
3914         brelse(old.dir_bh);
3915         brelse(new.dir_bh);
3916         brelse(old.bh);
3917         brelse(new.bh);
3918         if (handle)
3919                 ext4_journal_stop(handle);
3920         return retval;
3921 }
3922
3923 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3924                         struct inode *new_dir, struct dentry *new_dentry,
3925                         unsigned int flags)
3926 {
3927         int err;
3928
3929         if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
3930                 return -EIO;
3931
3932         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3933                 return -EINVAL;
3934
3935         err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
3936                                      flags);
3937         if (err)
3938                 return err;
3939
3940         if (flags & RENAME_EXCHANGE) {
3941                 return ext4_cross_rename(old_dir, old_dentry,
3942                                          new_dir, new_dentry);
3943         }
3944
3945         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3946 }
3947
3948 /*
3949  * directories can handle most operations...
3950  */
3951 const struct inode_operations ext4_dir_inode_operations = {
3952         .create         = ext4_create,
3953         .lookup         = ext4_lookup,
3954         .link           = ext4_link,
3955         .unlink         = ext4_unlink,
3956         .symlink        = ext4_symlink,
3957         .mkdir          = ext4_mkdir,
3958         .rmdir          = ext4_rmdir,
3959         .mknod          = ext4_mknod,
3960         .tmpfile        = ext4_tmpfile,
3961         .rename         = ext4_rename2,
3962         .setattr        = ext4_setattr,
3963         .getattr        = ext4_getattr,
3964         .listxattr      = ext4_listxattr,
3965         .get_acl        = ext4_get_acl,
3966         .set_acl        = ext4_set_acl,
3967         .fiemap         = ext4_fiemap,
3968 };
3969
3970 const struct inode_operations ext4_special_inode_operations = {
3971         .setattr        = ext4_setattr,
3972         .getattr        = ext4_getattr,
3973         .listxattr      = ext4_listxattr,
3974         .get_acl        = ext4_get_acl,
3975         .set_acl        = ext4_set_acl,
3976 };