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 /*
  86  * Hints to ext4_read_dirblock regarding whether we expect a directory
  87  * block being read to be an index block, or a block containing
  88  * directory entries (and if the latter, whether it was found via a
  89  * logical block in an htree index block).  This is used to control
  90  * what sort of sanity checkinig ext4_read_dirblock() will do on the
  91  * directory block read from the storage device.  EITHER will means
  92  * the caller doesn't know what kind of directory block will be read,
  93  * so no specific verification will be done.
  94  */
  95 typedef enum {
  96         EITHER, INDEX, DIRENT, DIRENT_HTREE
  97 } dirblock_type_t;
  98
  99 #define ext4_read_dirblock(inode, block, type) \
 100         __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
 101
 102 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 103                                                 ext4_lblk_t block,
 104                                                 dirblock_type_t type,
 105                                                 const char *func,
 106                                                 unsigned int line)
 107 {
 108         struct buffer_head *bh;
 109         struct ext4_dir_entry *dirent;
 110         int is_dx_block = 0;
 111
 112         if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO))
 113                 bh = ERR_PTR(-EIO);
 114         else
 115                 bh = ext4_bread(NULL, inode, block, 0);
 116         if (IS_ERR(bh)) {
 117                 __ext4_warning(inode->i_sb, func, line,
 118                                "inode #%lu: lblock %lu: comm %s: "
 119                                "error %ld reading directory block",
 120                                inode->i_ino, (unsigned long)block,
 121                                current->comm, PTR_ERR(bh));
 122
 123                 return bh;
 124         }
 125         if (!bh && (type == INDEX || type == DIRENT_HTREE)) {
 126                 ext4_error_inode(inode, func, line, block,
 127                                  "Directory hole found for htree %s block",
 128                                  (type == INDEX) ? "index" : "leaf");
 129                 return ERR_PTR(-EFSCORRUPTED);
 130         }
 131         if (!bh)
 132                 return NULL;
 133         dirent = (struct ext4_dir_entry *) bh->b_data;
 134         /* Determine whether or not we have an index block */
 135         if (is_dx(inode)) {
 136                 if (block == 0)
 137                         is_dx_block = 1;
 138                 else if (ext4_rec_len_from_disk(dirent->rec_len,
 139                                                 inode->i_sb->s_blocksize) ==
 140                          inode->i_sb->s_blocksize)
 141                         is_dx_block = 1;
 142         }
 143         if (!is_dx_block && type == INDEX) {
 144                 ext4_error_inode(inode, func, line, block,
 145                        "directory leaf block found instead of index block");
 146                 brelse(bh);
 147                 return ERR_PTR(-EFSCORRUPTED);
 148         }
 149         if (!ext4_has_metadata_csum(inode->i_sb) ||
 150             buffer_verified(bh))
 151                 return bh;
 152
 153         /*
 154          * An empty leaf block can get mistaken for a index block; for
 155          * this reason, we can only check the index checksum when the
 156          * caller is sure it should be an index block.
 157          */
 158         if (is_dx_block && type == INDEX) {
 159                 if (ext4_dx_csum_verify(inode, dirent) &&
 160                     !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
 161                         set_buffer_verified(bh);
 162                 else {
 163                         ext4_set_errno(inode->i_sb, EFSBADCRC);
 164                         ext4_error_inode(inode, func, line, block,
 165                                          "Directory index failed checksum");
 166                         brelse(bh);
 167                         return ERR_PTR(-EFSBADCRC);
 168                 }
 169         }
 170         if (!is_dx_block) {
 171                 if (ext4_dirblock_csum_verify(inode, bh) &&
 172                     !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
 173                         set_buffer_verified(bh);
 174                 else {
 175                         ext4_set_errno(inode->i_sb, EFSBADCRC);
 176                         ext4_error_inode(inode, func, line, block,
 177                                          "Directory block failed checksum");
 178                         brelse(bh);
 179                         return ERR_PTR(-EFSBADCRC);
 180                 }
 181         }
 182         return bh;
 183 }
 184
 185 #ifndef assert
 186 #define assert(test) J_ASSERT(test)
 187 #endif
 188
 189 #ifdef DX_DEBUG
 190 #define dxtrace(command) command
 191 #else
 192 #define dxtrace(command)
 193 #endif
 194
 195 struct fake_dirent
 196 {
 197         __le32 inode;
 198         __le16 rec_len;
 199         u8 name_len;
 200         u8 file_type;
 201 };
 202
 203 struct dx_countlimit
 204 {
 205         __le16 limit;
 206         __le16 count;
 207 };
 208
 209 struct dx_entry
 210 {
 211         __le32 hash;
 212         __le32 block;
 213 };
 214
 215 /*
 216  * dx_root_info is laid out so that if it should somehow get overlaid by a
 217  * dirent the two low bits of the hash version will be zero.  Therefore, the
 218  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 219  */
 220
 221 struct dx_root
 222 {
 223         struct fake_dirent dot;
 224         char dot_name[4];
 225         struct fake_dirent dotdot;
 226         char dotdot_name[4];
 227         struct dx_root_info
 228         {
 229                 __le32 reserved_zero;
 230                 u8 hash_version;
 231                 u8 info_length; /* 8 */
 232                 u8 indirect_levels;
 233                 u8 unused_flags;
 234         }
 235         info;
 236         struct dx_entry entries[0];
 237 };
 238
 239 struct dx_node
 240 {
 241         struct fake_dirent fake;
 242         struct dx_entry entries[0];
 243 };
 244
 245
 246 struct dx_frame
 247 {
 248         struct buffer_head *bh;
 249         struct dx_entry *entries;
 250         struct dx_entry *at;
 251 };
 252
 253 struct dx_map_entry
 254 {
 255         u32 hash;
 256         u16 offs;
 257         u16 size;
 258 };
 259
 260 /*
 261  * This goes at the end of each htree block.
 262  */
 263 struct dx_tail {
 264         u32 dt_reserved;
 265         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 266 };
 267
 268 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 269 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 270 static inline unsigned dx_get_hash(struct dx_entry *entry);
 271 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 272 static unsigned dx_get_count(struct dx_entry *entries);
 273 static unsigned dx_get_limit(struct dx_entry *entries);
 274 static void dx_set_count(struct dx_entry *entries, unsigned value);
 275 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 276 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 277 static unsigned dx_node_limit(struct inode *dir);
 278 static struct dx_frame *dx_probe(struct ext4_filename *fname,
 279                                  struct inode *dir,
 280                                  struct dx_hash_info *hinfo,
 281                                  struct dx_frame *frame);
 282 static void dx_release(struct dx_frame *frames);
 283 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 284                        unsigned blocksize, struct dx_hash_info *hinfo,
 285                        struct dx_map_entry map[]);
 286 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 287 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 288                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 289 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 290 static void dx_insert_block(struct dx_frame *frame,
 291                                         u32 hash, ext4_lblk_t block);
 292 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 293                                  struct dx_frame *frame,
 294                                  struct dx_frame *frames,
 295                                  __u32 *start_hash);
 296 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 297                 struct ext4_filename *fname,
 298                 struct ext4_dir_entry_2 **res_dir);
 299 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 300                              struct inode *dir, struct inode *inode);
 301
 302 /* checksumming functions */
 303 void ext4_initialize_dirent_tail(struct buffer_head *bh,
 304                                  unsigned int blocksize)
 305 {
 306         struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
 307
 308         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 309         t->det_rec_len = ext4_rec_len_to_disk(
 310                         sizeof(struct ext4_dir_entry_tail), blocksize);
 311         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 312 }
 313
 314 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 315 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 316                                                    struct buffer_head *bh)
 317 {
 318         struct ext4_dir_entry_tail *t;
 319
 320 #ifdef PARANOID
 321         struct ext4_dir_entry *d, *top;
 322
 323         d = (struct ext4_dir_entry *)bh->b_data;
 324         top = (struct ext4_dir_entry *)(bh->b_data +
 325                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 326                  sizeof(struct ext4_dir_entry_tail)));
 327         while (d < top && d->rec_len)
 328                 d = (struct ext4_dir_entry *)(((void *)d) +
 329                     le16_to_cpu(d->rec_len));
 330
 331         if (d != top)
 332                 return NULL;
 333
 334         t = (struct ext4_dir_entry_tail *)d;
 335 #else
 336         t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
 337 #endif
 338
 339         if (t->det_reserved_zero1 ||
 340             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 341             t->det_reserved_zero2 ||
 342             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 343                 return NULL;
 344
 345         return t;
 346 }
 347
 348 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
 349 {
 350         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 351         struct ext4_inode_info *ei = EXT4_I(inode);
 352         __u32 csum;
 353
 354         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 355         return cpu_to_le32(csum);
 356 }
 357
 358 #define warn_no_space_for_csum(inode)                                   \
 359         __warn_no_space_for_csum((inode), __func__, __LINE__)
 360
 361 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
 362                                      unsigned int line)
 363 {
 364         __ext4_warning_inode(inode, func, line,
 365                 "No space for directory leaf checksum. Please run e2fsck -D.");
 366 }
 367
 368 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
 369 {
 370         struct ext4_dir_entry_tail *t;
 371
 372         if (!ext4_has_metadata_csum(inode->i_sb))
 373                 return 1;
 374
 375         t = get_dirent_tail(inode, bh);
 376         if (!t) {
 377                 warn_no_space_for_csum(inode);
 378                 return 0;
 379         }
 380
 381         if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data,
 382                                                   (char *)t - bh->b_data))
 383                 return 0;
 384
 385         return 1;
 386 }
 387
 388 static void ext4_dirblock_csum_set(struct inode *inode,
 389                                  struct buffer_head *bh)
 390 {
 391         struct ext4_dir_entry_tail *t;
 392
 393         if (!ext4_has_metadata_csum(inode->i_sb))
 394                 return;
 395
 396         t = get_dirent_tail(inode, bh);
 397         if (!t) {
 398                 warn_no_space_for_csum(inode);
 399                 return;
 400         }
 401
 402         t->det_checksum = ext4_dirblock_csum(inode, bh->b_data,
 403                                              (char *)t - bh->b_data);
 404 }
 405
 406 int ext4_handle_dirty_dirblock(handle_t *handle,
 407                                struct inode *inode,
 408                                struct buffer_head *bh)
 409 {
 410         ext4_dirblock_csum_set(inode, bh);
 411         return ext4_handle_dirty_metadata(handle, inode, bh);
 412 }
 413
 414 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 415                                                struct ext4_dir_entry *dirent,
 416                                                int *offset)
 417 {
 418         struct ext4_dir_entry *dp;
 419         struct dx_root_info *root;
 420         int count_offset;
 421
 422         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 423                 count_offset = 8;
 424         else if (le16_to_cpu(dirent->rec_len) == 12) {
 425                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 426                 if (le16_to_cpu(dp->rec_len) !=
 427                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 428                         return NULL;
 429                 root = (struct dx_root_info *)(((void *)dp + 12));
 430                 if (root->reserved_zero ||
 431                     root->info_length != sizeof(struct dx_root_info))
 432                         return NULL;
 433                 count_offset = 32;
 434         } else
 435                 return NULL;
 436
 437         if (offset)
 438                 *offset = count_offset;
 439         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 440 }
 441
 442 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 443                            int count_offset, int count, struct dx_tail *t)
 444 {
 445         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 446         struct ext4_inode_info *ei = EXT4_I(inode);
 447         __u32 csum;
 448         int size;
 449         __u32 dummy_csum = 0;
 450         int offset = offsetof(struct dx_tail, dt_checksum);
 451
 452         size = count_offset + (count * sizeof(struct dx_entry));
 453         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 454         csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
 455         csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
 456
 457         return cpu_to_le32(csum);
 458 }
 459
 460 static int ext4_dx_csum_verify(struct inode *inode,
 461                                struct ext4_dir_entry *dirent)
 462 {
 463         struct dx_countlimit *c;
 464         struct dx_tail *t;
 465         int count_offset, limit, count;
 466
 467         if (!ext4_has_metadata_csum(inode->i_sb))
 468                 return 1;
 469
 470         c = get_dx_countlimit(inode, dirent, &count_offset);
 471         if (!c) {
 472                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 473                 return 0;
 474         }
 475         limit = le16_to_cpu(c->limit);
 476         count = le16_to_cpu(c->count);
 477         if (count_offset + (limit * sizeof(struct dx_entry)) >
 478             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 479                 warn_no_space_for_csum(inode);
 480                 return 0;
 481         }
 482         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 483
 484         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 485                                             count, t))
 486                 return 0;
 487         return 1;
 488 }
 489
 490 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 491 {
 492         struct dx_countlimit *c;
 493         struct dx_tail *t;
 494         int count_offset, limit, count;
 495
 496         if (!ext4_has_metadata_csum(inode->i_sb))
 497                 return;
 498
 499         c = get_dx_countlimit(inode, dirent, &count_offset);
 500         if (!c) {
 501                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 502                 return;
 503         }
 504         limit = le16_to_cpu(c->limit);
 505         count = le16_to_cpu(c->count);
 506         if (count_offset + (limit * sizeof(struct dx_entry)) >
 507             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 508                 warn_no_space_for_csum(inode);
 509                 return;
 510         }
 511         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 512
 513         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 514 }
 515
 516 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 517                                             struct inode *inode,
 518                                             struct buffer_head *bh)
 519 {
 520         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 521         return ext4_handle_dirty_metadata(handle, inode, bh);
 522 }
 523
 524 /*
 525  * p is at least 6 bytes before the end of page
 526  */
 527 static inline struct ext4_dir_entry_2 *
 528 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 529 {
 530         return (struct ext4_dir_entry_2 *)((char *)p +
 531                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 532 }
 533
 534 /*
 535  * Future: use high four bits of block for coalesce-on-delete flags
 536  * Mask them off for now.
 537  */
 538
 539 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 540 {
 541         return le32_to_cpu(entry->block) & 0x0fffffff;
 542 }
 543
 544 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 545 {
 546         entry->block = cpu_to_le32(value);
 547 }
 548
 549 static inline unsigned dx_get_hash(struct dx_entry *entry)
 550 {
 551         return le32_to_cpu(entry->hash);
 552 }
 553
 554 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 555 {
 556         entry->hash = cpu_to_le32(value);
 557 }
 558
 559 static inline unsigned dx_get_count(struct dx_entry *entries)
 560 {
 561         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 562 }
 563
 564 static inline unsigned dx_get_limit(struct dx_entry *entries)
 565 {
 566         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 567 }
 568
 569 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 570 {
 571         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 572 }
 573
 574 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 575 {
 576         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 577 }
 578
 579 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 580 {
 581         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 582                 EXT4_DIR_REC_LEN(2) - infosize;
 583
 584         if (ext4_has_metadata_csum(dir->i_sb))
 585                 entry_space -= sizeof(struct dx_tail);
 586         return entry_space / sizeof(struct dx_entry);
 587 }
 588
 589 static inline unsigned dx_node_limit(struct inode *dir)
 590 {
 591         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 592
 593         if (ext4_has_metadata_csum(dir->i_sb))
 594                 entry_space -= sizeof(struct dx_tail);
 595         return entry_space / sizeof(struct dx_entry);
 596 }
 597
 598 /*
 599  * Debug
 600  */
 601 #ifdef DX_DEBUG
 602 static void dx_show_index(char * label, struct dx_entry *entries)
 603 {
 604         int i, n = dx_get_count (entries);
 605         printk(KERN_DEBUG "%s index", label);
 606         for (i = 0; i < n; i++) {
 607                 printk(KERN_CONT " %x->%lu",
 608                        i ? dx_get_hash(entries + i) : 0,
 609                        (unsigned long)dx_get_block(entries + i));
 610         }
 611         printk(KERN_CONT "\n");
 612 }
 613
 614 struct stats
 615 {
 616         unsigned names;
 617         unsigned space;
 618         unsigned bcount;
 619 };
 620
 621 static struct stats dx_show_leaf(struct inode *dir,
 622                                 struct dx_hash_info *hinfo,
 623                                 struct ext4_dir_entry_2 *de,
 624                                 int size, int show_names)
 625 {
 626         unsigned names = 0, space = 0;
 627         char *base = (char *) de;
 628         struct dx_hash_info h = *hinfo;
 629
 630         printk("names: ");
 631         while ((char *) de < base + size)
 632         {
 633                 if (de->inode)
 634                 {
 635                         if (show_names)
 636                         {
 637 #ifdef CONFIG_FS_ENCRYPTION
 638                                 int len;
 639                                 char *name;
 640                                 struct fscrypt_str fname_crypto_str =
 641                                         FSTR_INIT(NULL, 0);
 642                                 int res = 0;
 643
 644                                 name  = de->name;
 645                                 len = de->name_len;
 646                                 if (IS_ENCRYPTED(dir))
 647                                         res = fscrypt_get_encryption_info(dir);
 648                                 if (res) {
 649                                         printk(KERN_WARNING "Error setting up"
 650                                                " fname crypto: %d\n", res);
 651                                 }
 652                                 if (!fscrypt_has_encryption_key(dir)) {
 653                                         /* Directory is not encrypted */
 654                                         ext4fs_dirhash(dir, de->name,
 655                                                 de->name_len, &h);
 656                                         printk("%*.s:(U)%x.%u ", len,
 657                                                name, h.hash,
 658                                                (unsigned) ((char *) de
 659                                                            - base));
 660                                 } else {
 661                                         struct fscrypt_str de_name =
 662                                                 FSTR_INIT(name, len);
 663
 664                                         /* Directory is encrypted */
 665                                         res = fscrypt_fname_alloc_buffer(
 666                                                 dir, len,
 667                                                 &fname_crypto_str);
 668                                         if (res)
 669                                                 printk(KERN_WARNING "Error "
 670                                                         "allocating crypto "
 671                                                         "buffer--skipping "
 672                                                         "crypto\n");
 673                                         res = fscrypt_fname_disk_to_usr(dir,
 674                                                 0, 0, &de_name,
 675                                                 &fname_crypto_str);
 676                                         if (res) {
 677                                                 printk(KERN_WARNING "Error "
 678                                                         "converting filename "
 679                                                         "from disk to usr"
 680                                                         "\n");
 681                                                 name = "??";
 682                                                 len = 2;
 683                                         } else {
 684                                                 name = fname_crypto_str.name;
 685                                                 len = fname_crypto_str.len;
 686                                         }
 687                                         ext4fs_dirhash(dir, de->name,
 688                                                        de->name_len, &h);
 689                                         printk("%*.s:(E)%x.%u ", len, name,
 690                                                h.hash, (unsigned) ((char *) de
 691                                                                    - base));
 692                                         fscrypt_fname_free_buffer(
 693                                                         &fname_crypto_str);
 694                                 }
 695 #else
 696                                 int len = de->name_len;
 697                                 char *name = de->name;
 698                                 ext4fs_dirhash(dir, de->name, de->name_len, &h);
 699                                 printk("%*.s:%x.%u ", len, name, h.hash,
 700                                        (unsigned) ((char *) de - base));
 701 #endif
 702                         }
 703                         space += EXT4_DIR_REC_LEN(de->name_len);
 704                         names++;
 705                 }
 706                 de = ext4_next_entry(de, size);
 707         }
 708         printk(KERN_CONT "(%i)\n", names);
 709         return (struct stats) { names, space, 1 };
 710 }
 711
 712 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 713                              struct dx_entry *entries, int levels)
 714 {
 715         unsigned blocksize = dir->i_sb->s_blocksize;
 716         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 717         unsigned bcount = 0;
 718         struct buffer_head *bh;
 719         printk("%i indexed blocks...\n", count);
 720         for (i = 0; i < count; i++, entries++)
 721         {
 722                 ext4_lblk_t block = dx_get_block(entries);
 723                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 724                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 725                 struct stats stats;
 726                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 727                 bh = ext4_bread(NULL,dir, block, 0);
 728                 if (!bh || IS_ERR(bh))
 729                         continue;
 730                 stats = levels?
 731                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 732                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 733                         bh->b_data, blocksize, 0);
 734                 names += stats.names;
 735                 space += stats.space;
 736                 bcount += stats.bcount;
 737                 brelse(bh);
 738         }
 739         if (bcount)
 740                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 741                        levels ? "" : "   ", names, space/bcount,
 742                        (space/bcount)*100/blocksize);
 743         return (struct stats) { names, space, bcount};
 744 }
 745 #endif /* DX_DEBUG */
 746
 747 /*
 748  * Probe for a directory leaf block to search.
 749  *
 750  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 751  * error in the directory index, and the caller should fall back to
 752  * searching the directory normally.  The callers of dx_probe **MUST**
 753  * check for this error code, and make sure it never gets reflected
 754  * back to userspace.
 755  */
 756 static struct dx_frame *
 757 dx_probe(struct ext4_filename *fname, struct inode *dir,
 758          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 759 {
 760         unsigned count, indirect;
 761         struct dx_entry *at, *entries, *p, *q, *m;
 762         struct dx_root *root;
 763         struct dx_frame *frame = frame_in;
 764         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 765         u32 hash;
 766
 767         memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
 768         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 769         if (IS_ERR(frame->bh))
 770                 return (struct dx_frame *) frame->bh;
 771
 772         root = (struct dx_root *) frame->bh->b_data;
 773         if (root->info.hash_version != DX_HASH_TEA &&
 774             root->info.hash_version != DX_HASH_HALF_MD4 &&
 775             root->info.hash_version != DX_HASH_LEGACY) {
 776                 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
 777                                    root->info.hash_version);
 778                 goto fail;
 779         }
 780         if (fname)
 781                 hinfo = &fname->hinfo;
 782         hinfo->hash_version = root->info.hash_version;
 783         if (hinfo->hash_version <= DX_HASH_TEA)
 784                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 785         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 786         if (fname && fname_name(fname))
 787                 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
 788         hash = hinfo->hash;
 789
 790         if (root->info.unused_flags & 1) {
 791                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
 792                                    root->info.unused_flags);
 793                 goto fail;
 794         }
 795
 796         indirect = root->info.indirect_levels;
 797         if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
 798                 ext4_warning(dir->i_sb,
 799                              "Directory (ino: %lu) htree depth %#06x exceed"
 800                              "supported value", dir->i_ino,
 801                              ext4_dir_htree_level(dir->i_sb));
 802                 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
 803                         ext4_warning(dir->i_sb, "Enable large directory "
 804                                                 "feature to access it");
 805                 }
 806                 goto fail;
 807         }
 808
 809         entries = (struct dx_entry *)(((char *)&root->info) +
 810                                       root->info.info_length);
 811
 812         if (dx_get_limit(entries) != dx_root_limit(dir,
 813                                                    root->info.info_length)) {
 814                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 815                                    dx_get_limit(entries),
 816                                    dx_root_limit(dir, root->info.info_length));
 817                 goto fail;
 818         }
 819
 820         dxtrace(printk("Look up %x", hash));
 821         while (1) {
 822                 count = dx_get_count(entries);
 823                 if (!count || count > dx_get_limit(entries)) {
 824                         ext4_warning_inode(dir,
 825                                            "dx entry: count %u beyond limit %u",
 826                                            count, dx_get_limit(entries));
 827                         goto fail;
 828                 }
 829
 830                 p = entries + 1;
 831                 q = entries + count - 1;
 832                 while (p <= q) {
 833                         m = p + (q - p) / 2;
 834                         dxtrace(printk(KERN_CONT "."));
 835                         if (dx_get_hash(m) > hash)
 836                                 q = m - 1;
 837                         else
 838                                 p = m + 1;
 839                 }
 840
 841                 if (0) { // linear search cross check
 842                         unsigned n = count - 1;
 843                         at = entries;
 844                         while (n--)
 845                         {
 846                                 dxtrace(printk(KERN_CONT ","));
 847                                 if (dx_get_hash(++at) > hash)
 848                                 {
 849                                         at--;
 850                                         break;
 851                                 }
 852                         }
 853                         assert (at == p - 1);
 854                 }
 855
 856                 at = p - 1;
 857                 dxtrace(printk(KERN_CONT " %x->%u\n",
 858                                at == entries ? 0 : dx_get_hash(at),
 859                                dx_get_block(at)));
 860                 frame->entries = entries;
 861                 frame->at = at;
 862                 if (!indirect--)
 863                         return frame;
 864                 frame++;
 865                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 866                 if (IS_ERR(frame->bh)) {
 867                         ret_err = (struct dx_frame *) frame->bh;
 868                         frame->bh = NULL;
 869                         goto fail;
 870                 }
 871                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 872
 873                 if (dx_get_limit(entries) != dx_node_limit(dir)) {
 874                         ext4_warning_inode(dir,
 875                                 "dx entry: limit %u != node limit %u",
 876                                 dx_get_limit(entries), dx_node_limit(dir));
 877                         goto fail;
 878                 }
 879         }
 880 fail:
 881         while (frame >= frame_in) {
 882                 brelse(frame->bh);
 883                 frame--;
 884         }
 885
 886         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 887                 ext4_warning_inode(dir,
 888                         "Corrupt directory, running e2fsck is recommended");
 889         return ret_err;
 890 }
 891
 892 static void dx_release(struct dx_frame *frames)
 893 {
 894         struct dx_root_info *info;
 895         int i;
 896         unsigned int indirect_levels;
 897
 898         if (frames[0].bh == NULL)
 899                 return;
 900
 901         info = &((struct dx_root *)frames[0].bh->b_data)->info;
 902         /* save local copy, "info" may be freed after brelse() */
 903         indirect_levels = info->indirect_levels;
 904         for (i = 0; i <= indirect_levels; i++) {
 905                 if (frames[i].bh == NULL)
 906                         break;
 907                 brelse(frames[i].bh);
 908                 frames[i].bh = NULL;
 909         }
 910 }
 911
 912 /*
 913  * This function increments the frame pointer to search the next leaf
 914  * block, and reads in the necessary intervening nodes if the search
 915  * should be necessary.  Whether or not the search is necessary is
 916  * controlled by the hash parameter.  If the hash value is even, then
 917  * the search is only continued if the next block starts with that
 918  * hash value.  This is used if we are searching for a specific file.
 919  *
 920  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 921  *
 922  * This function returns 1 if the caller should continue to search,
 923  * or 0 if it should not.  If there is an error reading one of the
 924  * index blocks, it will a negative error code.
 925  *
 926  * If start_hash is non-null, it will be filled in with the starting
 927  * hash of the next page.
 928  */
 929 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 930                                  struct dx_frame *frame,
 931                                  struct dx_frame *frames,
 932                                  __u32 *start_hash)
 933 {
 934         struct dx_frame *p;
 935         struct buffer_head *bh;
 936         int num_frames = 0;
 937         __u32 bhash;
 938
 939         p = frame;
 940         /*
 941          * Find the next leaf page by incrementing the frame pointer.
 942          * If we run out of entries in the interior node, loop around and
 943          * increment pointer in the parent node.  When we break out of
 944          * this loop, num_frames indicates the number of interior
 945          * nodes need to be read.
 946          */
 947         while (1) {
 948                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 949                         break;
 950                 if (p == frames)
 951                         return 0;
 952                 num_frames++;
 953                 p--;
 954         }
 955
 956         /*
 957          * If the hash is 1, then continue only if the next page has a
 958          * continuation hash of any value.  This is used for readdir
 959          * handling.  Otherwise, check to see if the hash matches the
 960          * desired contiuation hash.  If it doesn't, return since
 961          * there's no point to read in the successive index pages.
 962          */
 963         bhash = dx_get_hash(p->at);
 964         if (start_hash)
 965                 *start_hash = bhash;
 966         if ((hash & 1) == 0) {
 967                 if ((bhash & ~1) != hash)
 968                         return 0;
 969         }
 970         /*
 971          * If the hash is HASH_NB_ALWAYS, we always go to the next
 972          * block so no check is necessary
 973          */
 974         while (num_frames--) {
 975                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 976                 if (IS_ERR(bh))
 977                         return PTR_ERR(bh);
 978                 p++;
 979                 brelse(p->bh);
 980                 p->bh = bh;
 981                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 982         }
 983         return 1;
 984 }
 985
 986
 987 /*
 988  * This function fills a red-black tree with information from a
 989  * directory block.  It returns the number directory entries loaded
 990  * into the tree.  If there is an error it is returned in err.
 991  */
 992 static int htree_dirblock_to_tree(struct file *dir_file,
 993                                   struct inode *dir, ext4_lblk_t block,
 994                                   struct dx_hash_info *hinfo,
 995                                   __u32 start_hash, __u32 start_minor_hash)
 996 {
 997         struct buffer_head *bh;
 998         struct ext4_dir_entry_2 *de, *top;
 999         int err = 0, count = 0;
1000         struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
1001
1002         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
1003                                                         (unsigned long)block));
1004         bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1005         if (IS_ERR(bh))
1006                 return PTR_ERR(bh);
1007
1008         de = (struct ext4_dir_entry_2 *) bh->b_data;
1009         top = (struct ext4_dir_entry_2 *) ((char *) de +
1010                                            dir->i_sb->s_blocksize -
1011                                            EXT4_DIR_REC_LEN(0));
1012         /* Check if the directory is encrypted */
1013         if (IS_ENCRYPTED(dir)) {
1014                 err = fscrypt_get_encryption_info(dir);
1015                 if (err < 0) {
1016                         brelse(bh);
1017                         return err;
1018                 }
1019                 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
1020                                                      &fname_crypto_str);
1021                 if (err < 0) {
1022                         brelse(bh);
1023                         return err;
1024                 }
1025         }
1026
1027         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1028                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1029                                 bh->b_data, bh->b_size,
1030                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1031                                          + ((char *)de - bh->b_data))) {
1032                         /* silently ignore the rest of the block */
1033                         break;
1034                 }
1035                 ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
1036                 if ((hinfo->hash < start_hash) ||
1037                     ((hinfo->hash == start_hash) &&
1038                      (hinfo->minor_hash < start_minor_hash)))
1039                         continue;
1040                 if (de->inode == 0)
1041                         continue;
1042                 if (!IS_ENCRYPTED(dir)) {
1043                         tmp_str.name = de->name;
1044                         tmp_str.len = de->name_len;
1045                         err = ext4_htree_store_dirent(dir_file,
1046                                    hinfo->hash, hinfo->minor_hash, de,
1047                                    &tmp_str);
1048                 } else {
1049                         int save_len = fname_crypto_str.len;
1050                         struct fscrypt_str de_name = FSTR_INIT(de->name,
1051                                                                 de->name_len);
1052
1053                         /* Directory is encrypted */
1054                         err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1055                                         hinfo->minor_hash, &de_name,
1056                                         &fname_crypto_str);
1057                         if (err) {
1058                                 count = err;
1059                                 goto errout;
1060                         }
1061                         err = ext4_htree_store_dirent(dir_file,
1062                                    hinfo->hash, hinfo->minor_hash, de,
1063                                         &fname_crypto_str);
1064                         fname_crypto_str.len = save_len;
1065                 }
1066                 if (err != 0) {
1067                         count = err;
1068                         goto errout;
1069                 }
1070                 count++;
1071         }
1072 errout:
1073         brelse(bh);
1074         fscrypt_fname_free_buffer(&fname_crypto_str);
1075         return count;
1076 }
1077
1078
1079 /*
1080  * This function fills a red-black tree with information from a
1081  * directory.  We start scanning the directory in hash order, starting
1082  * at start_hash and start_minor_hash.
1083  *
1084  * This function returns the number of entries inserted into the tree,
1085  * or a negative error code.
1086  */
1087 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1088                          __u32 start_minor_hash, __u32 *next_hash)
1089 {
1090         struct dx_hash_info hinfo;
1091         struct ext4_dir_entry_2 *de;
1092         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1093         struct inode *dir;
1094         ext4_lblk_t block;
1095         int count = 0;
1096         int ret, err;
1097         __u32 hashval;
1098         struct fscrypt_str tmp_str;
1099
1100         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1101                        start_hash, start_minor_hash));
1102         dir = file_inode(dir_file);
1103         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1104                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1105                 if (hinfo.hash_version <= DX_HASH_TEA)
1106                         hinfo.hash_version +=
1107                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1108                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1109                 if (ext4_has_inline_data(dir)) {
1110                         int has_inline_data = 1;
1111                         count = ext4_inlinedir_to_tree(dir_file, dir, 0,
1112                                                        &hinfo, start_hash,
1113                                                        start_minor_hash,
1114                                                        &has_inline_data);
1115                         if (has_inline_data) {
1116                                 *next_hash = ~0;
1117                                 return count;
1118                         }
1119                 }
1120                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1121                                                start_hash, start_minor_hash);
1122                 *next_hash = ~0;
1123                 return count;
1124         }
1125         hinfo.hash = start_hash;
1126         hinfo.minor_hash = 0;
1127         frame = dx_probe(NULL, dir, &hinfo, frames);
1128         if (IS_ERR(frame))
1129                 return PTR_ERR(frame);
1130
1131         /* Add '.' and '..' from the htree header */
1132         if (!start_hash && !start_minor_hash) {
1133                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1134                 tmp_str.name = de->name;
1135                 tmp_str.len = de->name_len;
1136                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1137                                               de, &tmp_str);
1138                 if (err != 0)
1139                         goto errout;
1140                 count++;
1141         }
1142         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1143                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1144                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1145                 tmp_str.name = de->name;
1146                 tmp_str.len = de->name_len;
1147                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1148                                               de, &tmp_str);
1149                 if (err != 0)
1150                         goto errout;
1151                 count++;
1152         }
1153
1154         while (1) {
1155                 if (fatal_signal_pending(current)) {
1156                         err = -ERESTARTSYS;
1157                         goto errout;
1158                 }
1159                 cond_resched();
1160                 block = dx_get_block(frame->at);
1161                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1162                                              start_hash, start_minor_hash);
1163                 if (ret < 0) {
1164                         err = ret;
1165                         goto errout;
1166                 }
1167                 count += ret;
1168                 hashval = ~0;
1169                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1170                                             frame, frames, &hashval);
1171                 *next_hash = hashval;
1172                 if (ret < 0) {
1173                         err = ret;
1174                         goto errout;
1175                 }
1176                 /*
1177                  * Stop if:  (a) there are no more entries, or
1178                  * (b) we have inserted at least one entry and the
1179                  * next hash value is not a continuation
1180                  */
1181                 if ((ret == 0) ||
1182                     (count && ((hashval & 1) == 0)))
1183                         break;
1184         }
1185         dx_release(frames);
1186         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1187                        "next hash: %x\n", count, *next_hash));
1188         return count;
1189 errout:
1190         dx_release(frames);
1191         return (err);
1192 }
1193
1194 static inline int search_dirblock(struct buffer_head *bh,
1195                                   struct inode *dir,
1196                                   struct ext4_filename *fname,
1197                                   unsigned int offset,
1198                                   struct ext4_dir_entry_2 **res_dir)
1199 {
1200         return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1201                                fname, offset, res_dir);
1202 }
1203
1204 /*
1205  * Directory block splitting, compacting
1206  */
1207
1208 /*
1209  * Create map of hash values, offsets, and sizes, stored at end of block.
1210  * Returns number of entries mapped.
1211  */
1212 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1213                        unsigned blocksize, struct dx_hash_info *hinfo,
1214                        struct dx_map_entry *map_tail)
1215 {
1216         int count = 0;
1217         char *base = (char *) de;
1218         struct dx_hash_info h = *hinfo;
1219
1220         while ((char *) de < base + blocksize) {
1221                 if (de->name_len && de->inode) {
1222                         ext4fs_dirhash(dir, de->name, de->name_len, &h);
1223                         map_tail--;
1224                         map_tail->hash = h.hash;
1225                         map_tail->offs = ((char *) de - base)>>2;
1226                         map_tail->size = le16_to_cpu(de->rec_len);
1227                         count++;
1228                         cond_resched();
1229                 }
1230                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1231                 de = ext4_next_entry(de, blocksize);
1232         }
1233         return count;
1234 }
1235
1236 /* Sort map by hash value */
1237 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1238 {
1239         struct dx_map_entry *p, *q, *top = map + count - 1;
1240         int more;
1241         /* Combsort until bubble sort doesn't suck */
1242         while (count > 2) {
1243                 count = count*10/13;
1244                 if (count - 9 < 2) /* 9, 10 -> 11 */
1245                         count = 11;
1246                 for (p = top, q = p - count; q >= map; p--, q--)
1247                         if (p->hash < q->hash)
1248                                 swap(*p, *q);
1249         }
1250         /* Garden variety bubble sort */
1251         do {
1252                 more = 0;
1253                 q = top;
1254                 while (q-- > map) {
1255                         if (q[1].hash >= q[0].hash)
1256                                 continue;
1257                         swap(*(q+1), *q);
1258                         more = 1;
1259                 }
1260         } while(more);
1261 }
1262
1263 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1264 {
1265         struct dx_entry *entries = frame->entries;
1266         struct dx_entry *old = frame->at, *new = old + 1;
1267         int count = dx_get_count(entries);
1268
1269         assert(count < dx_get_limit(entries));
1270         assert(old < entries + count);
1271         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1272         dx_set_hash(new, hash);
1273         dx_set_block(new, block);
1274         dx_set_count(entries, count + 1);
1275 }
1276
1277 #ifdef CONFIG_UNICODE
1278 /*
1279  * Test whether a case-insensitive directory entry matches the filename
1280  * being searched for.  If quick is set, assume the name being looked up
1281  * is already in the casefolded form.
1282  *
1283  * Returns: 0 if the directory entry matches, more than 0 if it
1284  * doesn't match or less than zero on error.
1285  */
1286 int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
1287                     const struct qstr *entry, bool quick)
1288 {
1289         const struct ext4_sb_info *sbi = EXT4_SB(parent->i_sb);
1290         const struct unicode_map *um = sbi->s_encoding;
1291         int ret;
1292
1293         if (quick)
1294                 ret = utf8_strncasecmp_folded(um, name, entry);
1295         else
1296                 ret = utf8_strncasecmp(um, name, entry);
1297
1298         if (ret < 0) {
1299                 /* Handle invalid character sequence as either an error
1300                  * or as an opaque byte sequence.
1301                  */
1302                 if (ext4_has_strict_mode(sbi))
1303                         return -EINVAL;
1304
1305                 if (name->len != entry->len)
1306                         return 1;
1307
1308                 return !!memcmp(name->name, entry->name, name->len);
1309         }
1310
1311         return ret;
1312 }
1313
1314 void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
1315                                   struct fscrypt_str *cf_name)
1316 {
1317         int len;
1318
1319         if (!IS_CASEFOLDED(dir) || !EXT4_SB(dir->i_sb)->s_encoding) {
1320                 cf_name->name = NULL;
1321                 return;
1322         }
1323
1324         cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
1325         if (!cf_name->name)
1326                 return;
1327
1328         len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding,
1329                             iname, cf_name->name,
1330                             EXT4_NAME_LEN);
1331         if (len <= 0) {
1332                 kfree(cf_name->name);
1333                 cf_name->name = NULL;
1334                 return;
1335         }
1336         cf_name->len = (unsigned) len;
1337
1338 }
1339 #endif
1340
1341 /*
1342  * Test whether a directory entry matches the filename being searched for.
1343  *
1344  * Return: %true if the directory entry matches, otherwise %false.
1345  */
1346 static inline bool ext4_match(const struct inode *parent,
1347                               const struct ext4_filename *fname,
1348                               const struct ext4_dir_entry_2 *de)
1349 {
1350         struct fscrypt_name f;
1351 #ifdef CONFIG_UNICODE
1352         const struct qstr entry = {.name = de->name, .len = de->name_len};
1353 #endif
1354
1355         if (!de->inode)
1356                 return false;
1357
1358         f.usr_fname = fname->usr_fname;
1359         f.disk_name = fname->disk_name;
1360 #ifdef CONFIG_FS_ENCRYPTION
1361         f.crypto_buf = fname->crypto_buf;
1362 #endif
1363
1364 #ifdef CONFIG_UNICODE
1365         if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent)) {
1366                 if (fname->cf_name.name) {
1367                         struct qstr cf = {.name = fname->cf_name.name,
1368                                           .len = fname->cf_name.len};
1369                         return !ext4_ci_compare(parent, &cf, &entry, true);
1370                 }
1371                 return !ext4_ci_compare(parent, fname->usr_fname, &entry,
1372                                         false);
1373         }
1374 #endif
1375
1376         return fscrypt_match_name(&f, de->name, de->name_len);
1377 }
1378
1379 /*
1380  * Returns 0 if not found, -1 on failure, and 1 on success
1381  */
1382 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1383                     struct inode *dir, struct ext4_filename *fname,
1384                     unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1385 {
1386         struct ext4_dir_entry_2 * de;
1387         char * dlimit;
1388         int de_len;
1389
1390         de = (struct ext4_dir_entry_2 *)search_buf;
1391         dlimit = search_buf + buf_size;
1392         while ((char *) de < dlimit) {
1393                 /* this code is executed quadratically often */
1394                 /* do minimal checking `by hand' */
1395                 if ((char *) de + de->name_len <= dlimit &&
1396                     ext4_match(dir, fname, de)) {
1397                         /* found a match - just to be sure, do
1398                          * a full check */
1399                         if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1400                                                  bh->b_size, offset))
1401                                 return -1;
1402                         *res_dir = de;
1403                         return 1;
1404                 }
1405                 /* prevent looping on a bad block */
1406                 de_len = ext4_rec_len_from_disk(de->rec_len,
1407                                                 dir->i_sb->s_blocksize);
1408                 if (de_len <= 0)
1409                         return -1;
1410                 offset += de_len;
1411                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1412         }
1413         return 0;
1414 }
1415
1416 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1417                                struct ext4_dir_entry *de)
1418 {
1419         struct super_block *sb = dir->i_sb;
1420
1421         if (!is_dx(dir))
1422                 return 0;
1423         if (block == 0)
1424                 return 1;
1425         if (de->inode == 0 &&
1426             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1427                         sb->s_blocksize)
1428                 return 1;
1429         return 0;
1430 }
1431
1432 /*
1433  *      __ext4_find_entry()
1434  *
1435  * finds an entry in the specified directory with the wanted name. It
1436  * returns the cache buffer in which the entry was found, and the entry
1437  * itself (as a parameter - res_dir). It does NOT read the inode of the
1438  * entry - you'll have to do that yourself if you want to.
1439  *
1440  * The returned buffer_head has ->b_count elevated.  The caller is expected
1441  * to brelse() it when appropriate.
1442  */
1443 static struct buffer_head *__ext4_find_entry(struct inode *dir,
1444                                              struct ext4_filename *fname,
1445                                              struct ext4_dir_entry_2 **res_dir,
1446                                              int *inlined)
1447 {
1448         struct super_block *sb;
1449         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1450         struct buffer_head *bh, *ret = NULL;
1451         ext4_lblk_t start, block;
1452         const u8 *name = fname->usr_fname->name;
1453         size_t ra_max = 0;      /* Number of bh's in the readahead
1454                                    buffer, bh_use[] */
1455         size_t ra_ptr = 0;      /* Current index into readahead
1456                                    buffer */
1457         ext4_lblk_t  nblocks;
1458         int i, namelen, retval;
1459
1460         *res_dir = NULL;
1461         sb = dir->i_sb;
1462         namelen = fname->usr_fname->len;
1463         if (namelen > EXT4_NAME_LEN)
1464                 return NULL;
1465
1466         if (ext4_has_inline_data(dir)) {
1467                 int has_inline_data = 1;
1468                 ret = ext4_find_inline_entry(dir, fname, res_dir,
1469                                              &has_inline_data);
1470                 if (has_inline_data) {
1471                         if (inlined)
1472                                 *inlined = 1;
1473                         goto cleanup_and_exit;
1474                 }
1475         }
1476
1477         if ((namelen <= 2) && (name[0] == '.') &&
1478             (name[1] == '.' || name[1] == '\0')) {
1479                 /*
1480                  * "." or ".." will only be in the first block
1481                  * NFS may look up ".."; "." should be handled by the VFS
1482                  */
1483                 block = start = 0;
1484                 nblocks = 1;
1485                 goto restart;
1486         }
1487         if (is_dx(dir)) {
1488                 ret = ext4_dx_find_entry(dir, fname, res_dir);
1489                 /*
1490                  * On success, or if the error was file not found,
1491                  * return.  Otherwise, fall back to doing a search the
1492                  * old fashioned way.
1493                  */
1494                 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1495                         goto cleanup_and_exit;
1496                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1497                                "falling back\n"));
1498                 ret = NULL;
1499         }
1500         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1501         if (!nblocks) {
1502                 ret = NULL;
1503                 goto cleanup_and_exit;
1504         }
1505         start = EXT4_I(dir)->i_dir_start_lookup;
1506         if (start >= nblocks)
1507                 start = 0;
1508         block = start;
1509 restart:
1510         do {
1511                 /*
1512                  * We deal with the read-ahead logic here.
1513                  */
1514                 if (ra_ptr >= ra_max) {
1515                         /* Refill the readahead buffer */
1516                         ra_ptr = 0;
1517                         if (block < start)
1518                                 ra_max = start - block;
1519                         else
1520                                 ra_max = nblocks - block;
1521                         ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1522                         retval = ext4_bread_batch(dir, block, ra_max,
1523                                                   false /* wait */, bh_use);
1524                         if (retval) {
1525                                 ret = ERR_PTR(retval);
1526                                 ra_max = 0;
1527                                 goto cleanup_and_exit;
1528                         }
1529                 }
1530                 if ((bh = bh_use[ra_ptr++]) == NULL)
1531                         goto next;
1532                 wait_on_buffer(bh);
1533                 if (!buffer_uptodate(bh)) {
1534                         ext4_set_errno(sb, EIO);
1535                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1536                                          (unsigned long) block);
1537                         brelse(bh);
1538                         ret = ERR_PTR(-EIO);
1539                         goto cleanup_and_exit;
1540                 }
1541                 if (!buffer_verified(bh) &&
1542                     !is_dx_internal_node(dir, block,
1543                                          (struct ext4_dir_entry *)bh->b_data) &&
1544                     !ext4_dirblock_csum_verify(dir, bh)) {
1545                         ext4_set_errno(sb, EFSBADCRC);
1546                         EXT4_ERROR_INODE(dir, "checksumming directory "
1547                                          "block %lu", (unsigned long)block);
1548                         brelse(bh);
1549                         ret = ERR_PTR(-EFSBADCRC);
1550                         goto cleanup_and_exit;
1551                 }
1552                 set_buffer_verified(bh);
1553                 i = search_dirblock(bh, dir, fname,
1554                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1555                 if (i == 1) {
1556                         EXT4_I(dir)->i_dir_start_lookup = block;
1557                         ret = bh;
1558                         goto cleanup_and_exit;
1559                 } else {
1560                         brelse(bh);
1561                         if (i < 0)
1562                                 goto cleanup_and_exit;
1563                 }
1564         next:
1565                 if (++block >= nblocks)
1566                         block = 0;
1567         } while (block != start);
1568
1569         /*
1570          * If the directory has grown while we were searching, then
1571          * search the last part of the directory before giving up.
1572          */
1573         block = nblocks;
1574         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1575         if (block < nblocks) {
1576                 start = 0;
1577                 goto restart;
1578         }
1579
1580 cleanup_and_exit:
1581         /* Clean up the read-ahead blocks */
1582         for (; ra_ptr < ra_max; ra_ptr++)
1583                 brelse(bh_use[ra_ptr]);
1584         return ret;
1585 }
1586
1587 static struct buffer_head *ext4_find_entry(struct inode *dir,
1588                                            const struct qstr *d_name,
1589                                            struct ext4_dir_entry_2 **res_dir,
1590                                            int *inlined)
1591 {
1592         int err;
1593         struct ext4_filename fname;
1594         struct buffer_head *bh;
1595
1596         err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1597         if (err == -ENOENT)
1598                 return NULL;
1599         if (err)
1600                 return ERR_PTR(err);
1601
1602         bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
1603
1604         ext4_fname_free_filename(&fname);
1605         return bh;
1606 }
1607
1608 static struct buffer_head *ext4_lookup_entry(struct inode *dir,
1609                                              struct dentry *dentry,
1610                                              struct ext4_dir_entry_2 **res_dir)
1611 {
1612         int err;
1613         struct ext4_filename fname;
1614         struct buffer_head *bh;
1615
1616         err = ext4_fname_prepare_lookup(dir, dentry, &fname);
1617         if (err == -ENOENT)
1618                 return NULL;
1619         if (err)
1620                 return ERR_PTR(err);
1621
1622         bh = __ext4_find_entry(dir, &fname, res_dir, NULL);
1623
1624         ext4_fname_free_filename(&fname);
1625         return bh;
1626 }
1627
1628 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1629                         struct ext4_filename *fname,
1630                         struct ext4_dir_entry_2 **res_dir)
1631 {
1632         struct super_block * sb = dir->i_sb;
1633         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1634         struct buffer_head *bh;
1635         ext4_lblk_t block;
1636         int retval;
1637
1638 #ifdef CONFIG_FS_ENCRYPTION
1639         *res_dir = NULL;
1640 #endif
1641         frame = dx_probe(fname, dir, NULL, frames);
1642         if (IS_ERR(frame))
1643                 return (struct buffer_head *) frame;
1644         do {
1645                 block = dx_get_block(frame->at);
1646                 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1647                 if (IS_ERR(bh))
1648                         goto errout;
1649
1650                 retval = search_dirblock(bh, dir, fname,
1651                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1652                                          res_dir);
1653                 if (retval == 1)
1654                         goto success;
1655                 brelse(bh);
1656                 if (retval == -1) {
1657                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1658                         goto errout;
1659                 }
1660
1661                 /* Check to see if we should continue to search */
1662                 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1663                                                frames, NULL);
1664                 if (retval < 0) {
1665                         ext4_warning_inode(dir,
1666                                 "error %d reading directory index block",
1667                                 retval);
1668                         bh = ERR_PTR(retval);
1669                         goto errout;
1670                 }
1671         } while (retval == 1);
1672
1673         bh = NULL;
1674 errout:
1675         dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1676 success:
1677         dx_release(frames);
1678         return bh;
1679 }
1680
1681 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1682 {
1683         struct inode *inode;
1684         struct ext4_dir_entry_2 *de;
1685         struct buffer_head *bh;
1686
1687         if (dentry->d_name.len > EXT4_NAME_LEN)
1688                 return ERR_PTR(-ENAMETOOLONG);
1689
1690         bh = ext4_lookup_entry(dir, dentry, &de);
1691         if (IS_ERR(bh))
1692                 return ERR_CAST(bh);
1693         inode = NULL;
1694         if (bh) {
1695                 __u32 ino = le32_to_cpu(de->inode);
1696                 brelse(bh);
1697                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1698                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1699                         return ERR_PTR(-EFSCORRUPTED);
1700                 }
1701                 if (unlikely(ino == dir->i_ino)) {
1702                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1703                                          dentry);
1704                         return ERR_PTR(-EFSCORRUPTED);
1705                 }
1706                 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
1707                 if (inode == ERR_PTR(-ESTALE)) {
1708                         EXT4_ERROR_INODE(dir,
1709                                          "deleted inode referenced: %u",
1710                                          ino);
1711                         return ERR_PTR(-EFSCORRUPTED);
1712                 }
1713                 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) &&
1714                     (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1715                     !fscrypt_has_permitted_context(dir, inode)) {
1716                         ext4_warning(inode->i_sb,
1717                                      "Inconsistent encryption contexts: %lu/%lu",
1718                                      dir->i_ino, inode->i_ino);
1719                         iput(inode);
1720                         return ERR_PTR(-EPERM);
1721                 }
1722         }
1723
1724 #ifdef CONFIG_UNICODE
1725         if (!inode && IS_CASEFOLDED(dir)) {
1726                 /* Eventually we want to call d_add_ci(dentry, NULL)
1727                  * for negative dentries in the encoding case as
1728                  * well.  For now, prevent the negative dentry
1729                  * from being cached.
1730                  */
1731                 return NULL;
1732         }
1733 #endif
1734         return d_splice_alias(inode, dentry);
1735 }
1736
1737
1738 struct dentry *ext4_get_parent(struct dentry *child)
1739 {
1740         __u32 ino;
1741         static const struct qstr dotdot = QSTR_INIT("..", 2);
1742         struct ext4_dir_entry_2 * de;
1743         struct buffer_head *bh;
1744
1745         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1746         if (IS_ERR(bh))
1747                 return ERR_CAST(bh);
1748         if (!bh)
1749                 return ERR_PTR(-ENOENT);
1750         ino = le32_to_cpu(de->inode);
1751         brelse(bh);
1752
1753         if (!ext4_valid_inum(child->d_sb, ino)) {
1754                 EXT4_ERROR_INODE(d_inode(child),
1755                                  "bad parent inode number: %u", ino);
1756                 return ERR_PTR(-EFSCORRUPTED);
1757         }
1758
1759         return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
1760 }
1761
1762 /*
1763  * Move count entries from end of map between two memory locations.
1764  * Returns pointer to last entry moved.
1765  */
1766 static struct ext4_dir_entry_2 *
1767 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1768                 unsigned blocksize)
1769 {
1770         unsigned rec_len = 0;
1771
1772         while (count--) {
1773                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1774                                                 (from + (map->offs<<2));
1775                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1776                 memcpy (to, de, rec_len);
1777                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1778                                 ext4_rec_len_to_disk(rec_len, blocksize);
1779                 de->inode = 0;
1780                 map++;
1781                 to += rec_len;
1782         }
1783         return (struct ext4_dir_entry_2 *) (to - rec_len);
1784 }
1785
1786 /*
1787  * Compact each dir entry in the range to the minimal rec_len.
1788  * Returns pointer to last entry in range.
1789  */
1790 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1791 {
1792         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1793         unsigned rec_len = 0;
1794
1795         prev = to = de;
1796         while ((char*)de < base + blocksize) {
1797                 next = ext4_next_entry(de, blocksize);
1798                 if (de->inode && de->name_len) {
1799                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1800                         if (de > to)
1801                                 memmove(to, de, rec_len);
1802                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1803                         prev = to;
1804                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1805                 }
1806                 de = next;
1807         }
1808         return prev;
1809 }
1810
1811 /*
1812  * Split a full leaf block to make room for a new dir entry.
1813  * Allocate a new block, and move entries so that they are approx. equally full.
1814  * Returns pointer to de in block into which the new entry will be inserted.
1815  */
1816 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1817                         struct buffer_head **bh,struct dx_frame *frame,
1818                         struct dx_hash_info *hinfo)
1819 {
1820         unsigned blocksize = dir->i_sb->s_blocksize;
1821         unsigned count, continued;
1822         struct buffer_head *bh2;
1823         ext4_lblk_t newblock;
1824         u32 hash2;
1825         struct dx_map_entry *map;
1826         char *data1 = (*bh)->b_data, *data2;
1827         unsigned split, move, size;
1828         struct ext4_dir_entry_2 *de = NULL, *de2;
1829         int     csum_size = 0;
1830         int     err = 0, i;
1831
1832         if (ext4_has_metadata_csum(dir->i_sb))
1833                 csum_size = sizeof(struct ext4_dir_entry_tail);
1834
1835         bh2 = ext4_append(handle, dir, &newblock);
1836         if (IS_ERR(bh2)) {
1837                 brelse(*bh);
1838                 *bh = NULL;
1839                 return (struct ext4_dir_entry_2 *) bh2;
1840         }
1841
1842         BUFFER_TRACE(*bh, "get_write_access");
1843         err = ext4_journal_get_write_access(handle, *bh);
1844         if (err)
1845                 goto journal_error;
1846
1847         BUFFER_TRACE(frame->bh, "get_write_access");
1848         err = ext4_journal_get_write_access(handle, frame->bh);
1849         if (err)
1850                 goto journal_error;
1851
1852         data2 = bh2->b_data;
1853
1854         /* create map in the end of data2 block */
1855         map = (struct dx_map_entry *) (data2 + blocksize);
1856         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1857                              blocksize, hinfo, map);
1858         map -= count;
1859         dx_sort_map(map, count);
1860         /* Split the existing block in the middle, size-wise */
1861         size = 0;
1862         move = 0;
1863         for (i = count-1; i >= 0; i--) {
1864                 /* is more than half of this entry in 2nd half of the block? */
1865                 if (size + map[i].size/2 > blocksize/2)
1866                         break;
1867                 size += map[i].size;
1868                 move++;
1869         }
1870         /* map index at which we will split */
1871         split = count - move;
1872         hash2 = map[split].hash;
1873         continued = hash2 == map[split - 1].hash;
1874         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1875                         (unsigned long)dx_get_block(frame->at),
1876                                         hash2, split, count-split));
1877
1878         /* Fancy dance to stay within two buffers */
1879         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1880                               blocksize);
1881         de = dx_pack_dirents(data1, blocksize);
1882         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1883                                            (char *) de,
1884                                            blocksize);
1885         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1886                                             (char *) de2,
1887                                             blocksize);
1888         if (csum_size) {
1889                 ext4_initialize_dirent_tail(*bh, blocksize);
1890                 ext4_initialize_dirent_tail(bh2, blocksize);
1891         }
1892
1893         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1894                         blocksize, 1));
1895         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1896                         blocksize, 1));
1897
1898         /* Which block gets the new entry? */
1899         if (hinfo->hash >= hash2) {
1900                 swap(*bh, bh2);
1901                 de = de2;
1902         }
1903         dx_insert_block(frame, hash2 + continued, newblock);
1904         err = ext4_handle_dirty_dirblock(handle, dir, bh2);
1905         if (err)
1906                 goto journal_error;
1907         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1908         if (err)
1909                 goto journal_error;
1910         brelse(bh2);
1911         dxtrace(dx_show_index("frame", frame->entries));
1912         return de;
1913
1914 journal_error:
1915         brelse(*bh);
1916         brelse(bh2);
1917         *bh = NULL;
1918         ext4_std_error(dir->i_sb, err);
1919         return ERR_PTR(err);
1920 }
1921
1922 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1923                       struct buffer_head *bh,
1924                       void *buf, int buf_size,
1925                       struct ext4_filename *fname,
1926                       struct ext4_dir_entry_2 **dest_de)
1927 {
1928         struct ext4_dir_entry_2 *de;
1929         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1930         int nlen, rlen;
1931         unsigned int offset = 0;
1932         char *top;
1933
1934         de = (struct ext4_dir_entry_2 *)buf;
1935         top = buf + buf_size - reclen;
1936         while ((char *) de <= top) {
1937                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1938                                          buf, buf_size, offset))
1939                         return -EFSCORRUPTED;
1940                 if (ext4_match(dir, fname, de))
1941                         return -EEXIST;
1942                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1943                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1944                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1945                         break;
1946                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1947                 offset += rlen;
1948         }
1949         if ((char *) de > top)
1950                 return -ENOSPC;
1951
1952         *dest_de = de;
1953         return 0;
1954 }
1955
1956 void ext4_insert_dentry(struct inode *inode,
1957                         struct ext4_dir_entry_2 *de,
1958                         int buf_size,
1959                         struct ext4_filename *fname)
1960 {
1961
1962         int nlen, rlen;
1963
1964         nlen = EXT4_DIR_REC_LEN(de->name_len);
1965         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1966         if (de->inode) {
1967                 struct ext4_dir_entry_2 *de1 =
1968                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1969                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1970                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1971                 de = de1;
1972         }
1973         de->file_type = EXT4_FT_UNKNOWN;
1974         de->inode = cpu_to_le32(inode->i_ino);
1975         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1976         de->name_len = fname_len(fname);
1977         memcpy(de->name, fname_name(fname), fname_len(fname));
1978 }
1979
1980 /*
1981  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1982  * it points to a directory entry which is guaranteed to be large
1983  * enough for new directory entry.  If de is NULL, then
1984  * add_dirent_to_buf will attempt search the directory block for
1985  * space.  It will return -ENOSPC if no space is available, and -EIO
1986  * and -EEXIST if directory entry already exists.
1987  */
1988 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1989                              struct inode *dir,
1990                              struct inode *inode, struct ext4_dir_entry_2 *de,
1991                              struct buffer_head *bh)
1992 {
1993         unsigned int    blocksize = dir->i_sb->s_blocksize;
1994         int             csum_size = 0;
1995         int             err;
1996
1997         if (ext4_has_metadata_csum(inode->i_sb))
1998                 csum_size = sizeof(struct ext4_dir_entry_tail);
1999
2000         if (!de) {
2001                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
2002                                         blocksize - csum_size, fname, &de);
2003                 if (err)
2004                         return err;
2005         }
2006         BUFFER_TRACE(bh, "get_write_access");
2007         err = ext4_journal_get_write_access(handle, bh);
2008         if (err) {
2009                 ext4_std_error(dir->i_sb, err);
2010                 return err;
2011         }
2012
2013         /* By now the buffer is marked for journaling */
2014         ext4_insert_dentry(inode, de, blocksize, fname);
2015
2016         /*
2017          * XXX shouldn't update any times until successful
2018          * completion of syscall, but too many callers depend
2019          * on this.
2020          *
2021          * XXX similarly, too many callers depend on
2022          * ext4_new_inode() setting the times, but error
2023          * recovery deletes the inode, so the worst that can
2024          * happen is that the times are slightly out of date
2025          * and/or different from the directory change time.
2026          */
2027         dir->i_mtime = dir->i_ctime = current_time(dir);
2028         ext4_update_dx_flag(dir);
2029         inode_inc_iversion(dir);
2030         ext4_mark_inode_dirty(handle, dir);
2031         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2032         err = ext4_handle_dirty_dirblock(handle, dir, bh);
2033         if (err)
2034                 ext4_std_error(dir->i_sb, err);
2035         return 0;
2036 }
2037
2038 /*
2039  * This converts a one block unindexed directory to a 3 block indexed
2040  * directory, and adds the dentry to the indexed directory.
2041  */
2042 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
2043                             struct inode *dir,
2044                             struct inode *inode, struct buffer_head *bh)
2045 {
2046         struct buffer_head *bh2;
2047         struct dx_root  *root;
2048         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2049         struct dx_entry *entries;
2050         struct ext4_dir_entry_2 *de, *de2;
2051         char            *data2, *top;
2052         unsigned        len;
2053         int             retval;
2054         unsigned        blocksize;
2055         ext4_lblk_t  block;
2056         struct fake_dirent *fde;
2057         int csum_size = 0;
2058
2059         if (ext4_has_metadata_csum(inode->i_sb))
2060                 csum_size = sizeof(struct ext4_dir_entry_tail);
2061
2062         blocksize =  dir->i_sb->s_blocksize;
2063         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2064         BUFFER_TRACE(bh, "get_write_access");
2065         retval = ext4_journal_get_write_access(handle, bh);
2066         if (retval) {
2067                 ext4_std_error(dir->i_sb, retval);
2068                 brelse(bh);
2069                 return retval;
2070         }
2071         root = (struct dx_root *) bh->b_data;
2072
2073         /* The 0th block becomes the root, move the dirents out */
2074         fde = &root->dotdot;
2075         de = (struct ext4_dir_entry_2 *)((char *)fde +
2076                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2077         if ((char *) de >= (((char *) root) + blocksize)) {
2078                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2079                 brelse(bh);
2080                 return -EFSCORRUPTED;
2081         }
2082         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2083
2084         /* Allocate new block for the 0th block's dirents */
2085         bh2 = ext4_append(handle, dir, &block);
2086         if (IS_ERR(bh2)) {
2087                 brelse(bh);
2088                 return PTR_ERR(bh2);
2089         }
2090         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2091         data2 = bh2->b_data;
2092
2093         memcpy(data2, de, len);
2094         de = (struct ext4_dir_entry_2 *) data2;
2095         top = data2 + len;
2096         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2097                 de = de2;
2098         de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
2099                                            (char *) de, blocksize);
2100
2101         if (csum_size)
2102                 ext4_initialize_dirent_tail(bh2, blocksize);
2103
2104         /* Initialize the root; the dot dirents already exist */
2105         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2106         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2107                                            blocksize);
2108         memset (&root->info, 0, sizeof(root->info));
2109         root->info.info_length = sizeof(root->info);
2110         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2111         entries = root->entries;
2112         dx_set_block(entries, 1);
2113         dx_set_count(entries, 1);
2114         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2115
2116         /* Initialize as for dx_probe */
2117         fname->hinfo.hash_version = root->info.hash_version;
2118         if (fname->hinfo.hash_version <= DX_HASH_TEA)
2119                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2120         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2121         ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo);
2122
2123         memset(frames, 0, sizeof(frames));
2124         frame = frames;
2125         frame->entries = entries;
2126         frame->at = entries;
2127         frame->bh = bh;
2128
2129         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2130         if (retval)
2131                 goto out_frames;
2132         retval = ext4_handle_dirty_dirblock(handle, dir, bh2);
2133         if (retval)
2134                 goto out_frames;
2135
2136         de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2137         if (IS_ERR(de)) {
2138                 retval = PTR_ERR(de);
2139                 goto out_frames;
2140         }
2141
2142         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2143 out_frames:
2144         /*
2145          * Even if the block split failed, we have to properly write
2146          * out all the changes we did so far. Otherwise we can end up
2147          * with corrupted filesystem.
2148          */
2149         if (retval)
2150                 ext4_mark_inode_dirty(handle, dir);
2151         dx_release(frames);
2152         brelse(bh2);
2153         return retval;
2154 }
2155
2156 /*
2157  *      ext4_add_entry()
2158  *
2159  * adds a file entry to the specified directory, using the same
2160  * semantics as ext4_find_entry(). It returns NULL if it failed.
2161  *
2162  * NOTE!! The inode part of 'de' is left at 0 - which means you
2163  * may not sleep between calling this and putting something into
2164  * the entry, as someone else might have used it while you slept.
2165  */
2166 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2167                           struct inode *inode)
2168 {
2169         struct inode *dir = d_inode(dentry->d_parent);
2170         struct buffer_head *bh = NULL;
2171         struct ext4_dir_entry_2 *de;
2172         struct super_block *sb;
2173 #ifdef CONFIG_UNICODE
2174         struct ext4_sb_info *sbi;
2175 #endif
2176         struct ext4_filename fname;
2177         int     retval;
2178         int     dx_fallback=0;
2179         unsigned blocksize;
2180         ext4_lblk_t block, blocks;
2181         int     csum_size = 0;
2182
2183         if (ext4_has_metadata_csum(inode->i_sb))
2184                 csum_size = sizeof(struct ext4_dir_entry_tail);
2185
2186         sb = dir->i_sb;
2187         blocksize = sb->s_blocksize;
2188         if (!dentry->d_name.len)
2189                 return -EINVAL;
2190
2191 #ifdef CONFIG_UNICODE
2192         sbi = EXT4_SB(sb);
2193         if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) &&
2194             sbi->s_encoding && utf8_validate(sbi->s_encoding, &dentry->d_name))
2195                 return -EINVAL;
2196 #endif
2197
2198         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2199         if (retval)
2200                 return retval;
2201
2202         if (ext4_has_inline_data(dir)) {
2203                 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2204                 if (retval < 0)
2205                         goto out;
2206                 if (retval == 1) {
2207                         retval = 0;
2208                         goto out;
2209                 }
2210         }
2211
2212         if (is_dx(dir)) {
2213                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2214                 if (!retval || (retval != ERR_BAD_DX_DIR))
2215                         goto out;
2216                 /* Can we just ignore htree data? */
2217                 if (ext4_has_metadata_csum(sb)) {
2218                         EXT4_ERROR_INODE(dir,
2219                                 "Directory has corrupted htree index.");
2220                         retval = -EFSCORRUPTED;
2221                         goto out;
2222                 }
2223                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2224                 dx_fallback++;
2225                 ext4_mark_inode_dirty(handle, dir);
2226         }
2227         blocks = dir->i_size >> sb->s_blocksize_bits;
2228         for (block = 0; block < blocks; block++) {
2229                 bh = ext4_read_dirblock(dir, block, DIRENT);
2230                 if (bh == NULL) {
2231                         bh = ext4_bread(handle, dir, block,
2232                                         EXT4_GET_BLOCKS_CREATE);
2233                         goto add_to_new_block;
2234                 }
2235                 if (IS_ERR(bh)) {
2236                         retval = PTR_ERR(bh);
2237                         bh = NULL;
2238                         goto out;
2239                 }
2240                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2241                                            NULL, bh);
2242                 if (retval != -ENOSPC)
2243                         goto out;
2244
2245                 if (blocks == 1 && !dx_fallback &&
2246                     ext4_has_feature_dir_index(sb)) {
2247                         retval = make_indexed_dir(handle, &fname, dir,
2248                                                   inode, bh);
2249                         bh = NULL; /* make_indexed_dir releases bh */
2250                         goto out;
2251                 }
2252                 brelse(bh);
2253         }
2254         bh = ext4_append(handle, dir, &block);
2255 add_to_new_block:
2256         if (IS_ERR(bh)) {
2257                 retval = PTR_ERR(bh);
2258                 bh = NULL;
2259                 goto out;
2260         }
2261         de = (struct ext4_dir_entry_2 *) bh->b_data;
2262         de->inode = 0;
2263         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2264
2265         if (csum_size)
2266                 ext4_initialize_dirent_tail(bh, blocksize);
2267
2268         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2269 out:
2270         ext4_fname_free_filename(&fname);
2271         brelse(bh);
2272         if (retval == 0)
2273                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2274         return retval;
2275 }
2276
2277 /*
2278  * Returns 0 for success, or a negative error value
2279  */
2280 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2281                              struct inode *dir, struct inode *inode)
2282 {
2283         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2284         struct dx_entry *entries, *at;
2285         struct buffer_head *bh;
2286         struct super_block *sb = dir->i_sb;
2287         struct ext4_dir_entry_2 *de;
2288         int restart;
2289         int err;
2290
2291 again:
2292         restart = 0;
2293         frame = dx_probe(fname, dir, NULL, frames);
2294         if (IS_ERR(frame))
2295                 return PTR_ERR(frame);
2296         entries = frame->entries;
2297         at = frame->at;
2298         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
2299         if (IS_ERR(bh)) {
2300                 err = PTR_ERR(bh);
2301                 bh = NULL;
2302                 goto cleanup;
2303         }
2304
2305         BUFFER_TRACE(bh, "get_write_access");
2306         err = ext4_journal_get_write_access(handle, bh);
2307         if (err)
2308                 goto journal_error;
2309
2310         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2311         if (err != -ENOSPC)
2312                 goto cleanup;
2313
2314         err = 0;
2315         /* Block full, should compress but for now just split */
2316         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2317                        dx_get_count(entries), dx_get_limit(entries)));
2318         /* Need to split index? */
2319         if (dx_get_count(entries) == dx_get_limit(entries)) {
2320                 ext4_lblk_t newblock;
2321                 int levels = frame - frames + 1;
2322                 unsigned int icount;
2323                 int add_level = 1;
2324                 struct dx_entry *entries2;
2325                 struct dx_node *node2;
2326                 struct buffer_head *bh2;
2327
2328                 while (frame > frames) {
2329                         if (dx_get_count((frame - 1)->entries) <
2330                             dx_get_limit((frame - 1)->entries)) {
2331                                 add_level = 0;
2332                                 break;
2333                         }
2334                         frame--; /* split higher index block */
2335                         at = frame->at;
2336                         entries = frame->entries;
2337                         restart = 1;
2338                 }
2339                 if (add_level && levels == ext4_dir_htree_level(sb)) {
2340                         ext4_warning(sb, "Directory (ino: %lu) index full, "
2341                                          "reach max htree level :%d",
2342                                          dir->i_ino, levels);
2343                         if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2344                                 ext4_warning(sb, "Large directory feature is "
2345                                                  "not enabled on this "
2346                                                  "filesystem");
2347                         }
2348                         err = -ENOSPC;
2349                         goto cleanup;
2350                 }
2351                 icount = dx_get_count(entries);
2352                 bh2 = ext4_append(handle, dir, &newblock);
2353                 if (IS_ERR(bh2)) {
2354                         err = PTR_ERR(bh2);
2355                         goto cleanup;
2356                 }
2357                 node2 = (struct dx_node *)(bh2->b_data);
2358                 entries2 = node2->entries;
2359                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2360                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2361                                                            sb->s_blocksize);
2362                 BUFFER_TRACE(frame->bh, "get_write_access");
2363                 err = ext4_journal_get_write_access(handle, frame->bh);
2364                 if (err)
2365                         goto journal_error;
2366                 if (!add_level) {
2367                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2368                         unsigned hash2 = dx_get_hash(entries + icount1);
2369                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2370                                        icount1, icount2));
2371
2372                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2373                         err = ext4_journal_get_write_access(handle,
2374                                                              (frame - 1)->bh);
2375                         if (err)
2376                                 goto journal_error;
2377
2378                         memcpy((char *) entries2, (char *) (entries + icount1),
2379                                icount2 * sizeof(struct dx_entry));
2380                         dx_set_count(entries, icount1);
2381                         dx_set_count(entries2, icount2);
2382                         dx_set_limit(entries2, dx_node_limit(dir));
2383
2384                         /* Which index block gets the new entry? */
2385                         if (at - entries >= icount1) {
2386                                 frame->at = at = at - entries - icount1 + entries2;
2387                                 frame->entries = entries = entries2;
2388                                 swap(frame->bh, bh2);
2389                         }
2390                         dx_insert_block((frame - 1), hash2, newblock);
2391                         dxtrace(dx_show_index("node", frame->entries));
2392                         dxtrace(dx_show_index("node",
2393                                ((struct dx_node *) bh2->b_data)->entries));
2394                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2395                         if (err)
2396                                 goto journal_error;
2397                         brelse (bh2);
2398                         err = ext4_handle_dirty_dx_node(handle, dir,
2399                                                    (frame - 1)->bh);
2400                         if (err)
2401                                 goto journal_error;
2402                         if (restart) {
2403                                 err = ext4_handle_dirty_dx_node(handle, dir,
2404                                                            frame->bh);
2405                                 goto journal_error;
2406                         }
2407                 } else {
2408                         struct dx_root *dxroot;
2409                         memcpy((char *) entries2, (char *) entries,
2410                                icount * sizeof(struct dx_entry));
2411                         dx_set_limit(entries2, dx_node_limit(dir));
2412
2413                         /* Set up root */
2414                         dx_set_count(entries, 1);
2415                         dx_set_block(entries + 0, newblock);
2416                         dxroot = (struct dx_root *)frames[0].bh->b_data;
2417                         dxroot->info.indirect_levels += 1;
2418                         dxtrace(printk(KERN_DEBUG
2419                                        "Creating %d level index...\n",
2420                                        dxroot->info.indirect_levels));
2421                         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2422                         if (err)
2423                                 goto journal_error;
2424                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2425                         brelse(bh2);
2426                         restart = 1;
2427                         goto journal_error;
2428                 }
2429         }
2430         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2431         if (IS_ERR(de)) {
2432                 err = PTR_ERR(de);
2433                 goto cleanup;
2434         }
2435         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2436         goto cleanup;
2437
2438 journal_error:
2439         ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2440 cleanup:
2441         brelse(bh);
2442         dx_release(frames);
2443         /* @restart is true means htree-path has been changed, we need to
2444          * repeat dx_probe() to find out valid htree-path
2445          */
2446         if (restart && err == 0)
2447                 goto again;
2448         return err;
2449 }
2450
2451 /*
2452  * ext4_generic_delete_entry deletes a directory entry by merging it
2453  * with the previous entry
2454  */
2455 int ext4_generic_delete_entry(handle_t *handle,
2456                               struct inode *dir,
2457                               struct ext4_dir_entry_2 *de_del,
2458                               struct buffer_head *bh,
2459                               void *entry_buf,
2460                               int buf_size,
2461                               int csum_size)
2462 {
2463         struct ext4_dir_entry_2 *de, *pde;
2464         unsigned int blocksize = dir->i_sb->s_blocksize;
2465         int i;
2466
2467         i = 0;
2468         pde = NULL;
2469         de = (struct ext4_dir_entry_2 *)entry_buf;
2470         while (i < buf_size - csum_size) {
2471                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2472                                          bh->b_data, bh->b_size, i))
2473                         return -EFSCORRUPTED;
2474                 if (de == de_del)  {
2475                         if (pde)
2476                                 pde->rec_len = ext4_rec_len_to_disk(
2477                                         ext4_rec_len_from_disk(pde->rec_len,
2478                                                                blocksize) +
2479                                         ext4_rec_len_from_disk(de->rec_len,
2480                                                                blocksize),
2481                                         blocksize);
2482                         else
2483                                 de->inode = 0;
2484                         inode_inc_iversion(dir);
2485                         return 0;
2486                 }
2487                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2488                 pde = de;
2489                 de = ext4_next_entry(de, blocksize);
2490         }
2491         return -ENOENT;
2492 }
2493
2494 static int ext4_delete_entry(handle_t *handle,
2495                              struct inode *dir,
2496                              struct ext4_dir_entry_2 *de_del,
2497                              struct buffer_head *bh)
2498 {
2499         int err, csum_size = 0;
2500
2501         if (ext4_has_inline_data(dir)) {
2502                 int has_inline_data = 1;
2503                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2504                                                &has_inline_data);
2505                 if (has_inline_data)
2506                         return err;
2507         }
2508
2509         if (ext4_has_metadata_csum(dir->i_sb))
2510                 csum_size = sizeof(struct ext4_dir_entry_tail);
2511
2512         BUFFER_TRACE(bh, "get_write_access");
2513         err = ext4_journal_get_write_access(handle, bh);
2514         if (unlikely(err))
2515                 goto out;
2516
2517         err = ext4_generic_delete_entry(handle, dir, de_del,
2518                                         bh, bh->b_data,
2519                                         dir->i_sb->s_blocksize, csum_size);
2520         if (err)
2521                 goto out;
2522
2523         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2524         err = ext4_handle_dirty_dirblock(handle, dir, bh);
2525         if (unlikely(err))
2526                 goto out;
2527
2528         return 0;
2529 out:
2530         if (err != -ENOENT)
2531                 ext4_std_error(dir->i_sb, err);
2532         return err;
2533 }
2534
2535 /*
2536  * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2537  * since this indicates that nlinks count was previously 1 to avoid overflowing
2538  * the 16-bit i_links_count field on disk.  Directories with i_nlink == 1 mean
2539  * that subdirectory link counts are not being maintained accurately.
2540  *
2541  * The caller has already checked for i_nlink overflow in case the DIR_LINK
2542  * feature is not enabled and returned -EMLINK.  The is_dx() check is a proxy
2543  * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2544  * on regular files) and to avoid creating huge/slow non-HTREE directories.
2545  */
2546 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2547 {
2548         inc_nlink(inode);
2549         if (is_dx(inode) &&
2550             (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2551                 set_nlink(inode, 1);
2552 }
2553
2554 /*
2555  * If a directory had nlink == 1, then we should let it be 1. This indicates
2556  * directory has >EXT4_LINK_MAX subdirs.
2557  */
2558 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2559 {
2560         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2561                 drop_nlink(inode);
2562 }
2563
2564
2565 /*
2566  * Add non-directory inode to a directory. On success, the inode reference is
2567  * consumed by dentry is instantiation. This is also indicated by clearing of
2568  * *inodep pointer. On failure, the caller is responsible for dropping the
2569  * inode reference in the safe context.
2570  */
2571 static int ext4_add_nondir(handle_t *handle,
2572                 struct dentry *dentry, struct inode **inodep)
2573 {
2574         struct inode *dir = d_inode(dentry->d_parent);
2575         struct inode *inode = *inodep;
2576         int err = ext4_add_entry(handle, dentry, inode);
2577         if (!err) {
2578                 ext4_mark_inode_dirty(handle, inode);
2579                 if (IS_DIRSYNC(dir))
2580                         ext4_handle_sync(handle);
2581                 d_instantiate_new(dentry, inode);
2582                 *inodep = NULL;
2583                 return 0;
2584         }
2585         drop_nlink(inode);
2586         ext4_orphan_add(handle, inode);
2587         unlock_new_inode(inode);
2588         return err;
2589 }
2590
2591 /*
2592  * By the time this is called, we already have created
2593  * the directory cache entry for the new file, but it
2594  * is so far negative - it has no inode.
2595  *
2596  * If the create succeeds, we fill in the inode information
2597  * with d_instantiate().
2598  */
2599 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2600                        bool excl)
2601 {
2602         handle_t *handle;
2603         struct inode *inode;
2604         int err, credits, retries = 0;
2605
2606         err = dquot_initialize(dir);
2607         if (err)
2608                 return err;
2609
2610         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2611                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2612 retry:
2613         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2614                                             NULL, EXT4_HT_DIR, credits);
2615         handle = ext4_journal_current_handle();
2616         err = PTR_ERR(inode);
2617         if (!IS_ERR(inode)) {
2618                 inode->i_op = &ext4_file_inode_operations;
2619                 inode->i_fop = &ext4_file_operations;
2620                 ext4_set_aops(inode);
2621                 err = ext4_add_nondir(handle, dentry, &inode);
2622         }
2623         if (handle)
2624                 ext4_journal_stop(handle);
2625         if (!IS_ERR_OR_NULL(inode))
2626                 iput(inode);
2627         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2628                 goto retry;
2629         return err;
2630 }
2631
2632 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2633                       umode_t mode, dev_t rdev)
2634 {
2635         handle_t *handle;
2636         struct inode *inode;
2637         int err, credits, retries = 0;
2638
2639         err = dquot_initialize(dir);
2640         if (err)
2641                 return err;
2642
2643         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2644                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2645 retry:
2646         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2647                                             NULL, EXT4_HT_DIR, credits);
2648         handle = ext4_journal_current_handle();
2649         err = PTR_ERR(inode);
2650         if (!IS_ERR(inode)) {
2651                 init_special_inode(inode, inode->i_mode, rdev);
2652                 inode->i_op = &ext4_special_inode_operations;
2653                 err = ext4_add_nondir(handle, dentry, &inode);
2654         }
2655         if (handle)
2656                 ext4_journal_stop(handle);
2657         if (!IS_ERR_OR_NULL(inode))
2658                 iput(inode);
2659         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2660                 goto retry;
2661         return err;
2662 }
2663
2664 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2665 {
2666         handle_t *handle;
2667         struct inode *inode;
2668         int err, retries = 0;
2669
2670         err = dquot_initialize(dir);
2671         if (err)
2672                 return err;
2673
2674 retry:
2675         inode = ext4_new_inode_start_handle(dir, mode,
2676                                             NULL, 0, NULL,
2677                                             EXT4_HT_DIR,
2678                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2679                           4 + EXT4_XATTR_TRANS_BLOCKS);
2680         handle = ext4_journal_current_handle();
2681         err = PTR_ERR(inode);
2682         if (!IS_ERR(inode)) {
2683                 inode->i_op = &ext4_file_inode_operations;
2684                 inode->i_fop = &ext4_file_operations;
2685                 ext4_set_aops(inode);
2686                 d_tmpfile(dentry, inode);
2687                 err = ext4_orphan_add(handle, inode);
2688                 if (err)
2689                         goto err_unlock_inode;
2690                 mark_inode_dirty(inode);
2691                 unlock_new_inode(inode);
2692         }
2693         if (handle)
2694                 ext4_journal_stop(handle);
2695         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2696                 goto retry;
2697         return err;
2698 err_unlock_inode:
2699         ext4_journal_stop(handle);
2700         unlock_new_inode(inode);
2701         return err;
2702 }
2703
2704 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2705                           struct ext4_dir_entry_2 *de,
2706                           int blocksize, int csum_size,
2707                           unsigned int parent_ino, int dotdot_real_len)
2708 {
2709         de->inode = cpu_to_le32(inode->i_ino);
2710         de->name_len = 1;
2711         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2712                                            blocksize);
2713         strcpy(de->name, ".");
2714         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2715
2716         de = ext4_next_entry(de, blocksize);
2717         de->inode = cpu_to_le32(parent_ino);
2718         de->name_len = 2;
2719         if (!dotdot_real_len)
2720                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2721                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2722                                         blocksize);
2723         else
2724                 de->rec_len = ext4_rec_len_to_disk(
2725                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2726         strcpy(de->name, "..");
2727         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2728
2729         return ext4_next_entry(de, blocksize);
2730 }
2731
2732 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2733                              struct inode *inode)
2734 {
2735         struct buffer_head *dir_block = NULL;
2736         struct ext4_dir_entry_2 *de;
2737         ext4_lblk_t block = 0;
2738         unsigned int blocksize = dir->i_sb->s_blocksize;
2739         int csum_size = 0;
2740         int err;
2741
2742         if (ext4_has_metadata_csum(dir->i_sb))
2743                 csum_size = sizeof(struct ext4_dir_entry_tail);
2744
2745         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2746                 err = ext4_try_create_inline_dir(handle, dir, inode);
2747                 if (err < 0 && err != -ENOSPC)
2748                         goto out;
2749                 if (!err)
2750                         goto out;
2751         }
2752
2753         inode->i_size = 0;
2754         dir_block = ext4_append(handle, inode, &block);
2755         if (IS_ERR(dir_block))
2756                 return PTR_ERR(dir_block);
2757         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2758         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2759         set_nlink(inode, 2);
2760         if (csum_size)
2761                 ext4_initialize_dirent_tail(dir_block, blocksize);
2762
2763         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2764         err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
2765         if (err)
2766                 goto out;
2767         set_buffer_verified(dir_block);
2768 out:
2769         brelse(dir_block);
2770         return err;
2771 }
2772
2773 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2774 {
2775         handle_t *handle;
2776         struct inode *inode;
2777         int err, credits, retries = 0;
2778
2779         if (EXT4_DIR_LINK_MAX(dir))
2780                 return -EMLINK;
2781
2782         err = dquot_initialize(dir);
2783         if (err)
2784                 return err;
2785
2786         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2787                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2788 retry:
2789         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2790                                             &dentry->d_name,
2791                                             0, NULL, EXT4_HT_DIR, credits);
2792         handle = ext4_journal_current_handle();
2793         err = PTR_ERR(inode);
2794         if (IS_ERR(inode))
2795                 goto out_stop;
2796
2797         inode->i_op = &ext4_dir_inode_operations;
2798         inode->i_fop = &ext4_dir_operations;
2799         err = ext4_init_new_dir(handle, dir, inode);
2800         if (err)
2801                 goto out_clear_inode;
2802         err = ext4_mark_inode_dirty(handle, inode);
2803         if (!err)
2804                 err = ext4_add_entry(handle, dentry, inode);
2805         if (err) {
2806 out_clear_inode:
2807                 clear_nlink(inode);
2808                 ext4_orphan_add(handle, inode);
2809                 unlock_new_inode(inode);
2810                 ext4_mark_inode_dirty(handle, inode);
2811                 ext4_journal_stop(handle);
2812                 iput(inode);
2813                 goto out_retry;
2814         }
2815         ext4_inc_count(handle, dir);
2816         ext4_update_dx_flag(dir);
2817         err = ext4_mark_inode_dirty(handle, dir);
2818         if (err)
2819                 goto out_clear_inode;
2820         d_instantiate_new(dentry, inode);
2821         if (IS_DIRSYNC(dir))
2822                 ext4_handle_sync(handle);
2823
2824 out_stop:
2825         if (handle)
2826                 ext4_journal_stop(handle);
2827 out_retry:
2828         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2829                 goto retry;
2830         return err;
2831 }
2832
2833 /*
2834  * routine to check that the specified directory is empty (for rmdir)
2835  */
2836 bool ext4_empty_dir(struct inode *inode)
2837 {
2838         unsigned int offset;
2839         struct buffer_head *bh;
2840         struct ext4_dir_entry_2 *de;
2841         struct super_block *sb;
2842
2843         if (ext4_has_inline_data(inode)) {
2844                 int has_inline_data = 1;
2845                 int ret;
2846
2847                 ret = empty_inline_dir(inode, &has_inline_data);
2848                 if (has_inline_data)
2849                         return ret;
2850         }
2851
2852         sb = inode->i_sb;
2853         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2854                 EXT4_ERROR_INODE(inode, "invalid size");
2855                 return true;
2856         }
2857         /* The first directory block must not be a hole,
2858          * so treat it as DIRENT_HTREE
2859          */
2860         bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
2861         if (IS_ERR(bh))
2862                 return true;
2863
2864         de = (struct ext4_dir_entry_2 *) bh->b_data;
2865         if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
2866                                  0) ||
2867             le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
2868                 ext4_warning_inode(inode, "directory missing '.'");
2869                 brelse(bh);
2870                 return true;
2871         }
2872         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2873         de = ext4_next_entry(de, sb->s_blocksize);
2874         if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
2875                                  offset) ||
2876             le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
2877                 ext4_warning_inode(inode, "directory missing '..'");
2878                 brelse(bh);
2879                 return true;
2880         }
2881         offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2882         while (offset < inode->i_size) {
2883                 if (!(offset & (sb->s_blocksize - 1))) {
2884                         unsigned int lblock;
2885                         brelse(bh);
2886                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2887                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2888                         if (bh == NULL) {
2889                                 offset += sb->s_blocksize;
2890                                 continue;
2891                         }
2892                         if (IS_ERR(bh))
2893                                 return true;
2894                 }
2895                 de = (struct ext4_dir_entry_2 *) (bh->b_data +
2896                                         (offset & (sb->s_blocksize - 1)));
2897                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2898                                          bh->b_data, bh->b_size, offset)) {
2899                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2900                         continue;
2901                 }
2902                 if (le32_to_cpu(de->inode)) {
2903                         brelse(bh);
2904                         return false;
2905                 }
2906                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2907         }
2908         brelse(bh);
2909         return true;
2910 }
2911
2912 /*
2913  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2914  * such inodes, starting at the superblock, in case we crash before the
2915  * file is closed/deleted, or in case the inode truncate spans multiple
2916  * transactions and the last transaction is not recovered after a crash.
2917  *
2918  * At filesystem recovery time, we walk this list deleting unlinked
2919  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2920  *
2921  * Orphan list manipulation functions must be called under i_mutex unless
2922  * we are just creating the inode or deleting it.
2923  */
2924 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2925 {
2926         struct super_block *sb = inode->i_sb;
2927         struct ext4_sb_info *sbi = EXT4_SB(sb);
2928         struct ext4_iloc iloc;
2929         int err = 0, rc;
2930         bool dirty = false;
2931
2932         if (!sbi->s_journal || is_bad_inode(inode))
2933                 return 0;
2934
2935         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2936                      !inode_is_locked(inode));
2937         /*
2938          * Exit early if inode already is on orphan list. This is a big speedup
2939          * since we don't have to contend on the global s_orphan_lock.
2940          */
2941         if (!list_empty(&EXT4_I(inode)->i_orphan))
2942                 return 0;
2943
2944         /*
2945          * Orphan handling is only valid for files with data blocks
2946          * being truncated, or files being unlinked. Note that we either
2947          * hold i_mutex, or the inode can not be referenced from outside,
2948          * so i_nlink should not be bumped due to race
2949          */
2950         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2951                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2952
2953         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2954         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2955         if (err)
2956                 goto out;
2957
2958         err = ext4_reserve_inode_write(handle, inode, &iloc);
2959         if (err)
2960                 goto out;
2961
2962         mutex_lock(&sbi->s_orphan_lock);
2963         /*
2964          * Due to previous errors inode may be already a part of on-disk
2965          * orphan list. If so skip on-disk list modification.
2966          */
2967         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2968             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2969                 /* Insert this inode at the head of the on-disk orphan list */
2970                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2971                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2972                 dirty = true;
2973         }
2974         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2975         mutex_unlock(&sbi->s_orphan_lock);
2976
2977         if (dirty) {
2978                 err = ext4_handle_dirty_super(handle, sb);
2979                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2980                 if (!err)
2981                         err = rc;
2982                 if (err) {
2983                         /*
2984                          * We have to remove inode from in-memory list if
2985                          * addition to on disk orphan list failed. Stray orphan
2986                          * list entries can cause panics at unmount time.
2987                          */
2988                         mutex_lock(&sbi->s_orphan_lock);
2989                         list_del_init(&EXT4_I(inode)->i_orphan);
2990                         mutex_unlock(&sbi->s_orphan_lock);
2991                 }
2992         } else
2993                 brelse(iloc.bh);
2994
2995         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2996         jbd_debug(4, "orphan inode %lu will point to %d\n",
2997                         inode->i_ino, NEXT_ORPHAN(inode));
2998 out:
2999         ext4_std_error(sb, err);
3000         return err;
3001 }
3002
3003 /*
3004  * ext4_orphan_del() removes an unlinked or truncated inode from the list
3005  * of such inodes stored on disk, because it is finally being cleaned up.
3006  */
3007 int ext4_orphan_del(handle_t *handle, struct inode *inode)
3008 {
3009         struct list_head *prev;
3010         struct ext4_inode_info *ei = EXT4_I(inode);
3011         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3012         __u32 ino_next;
3013         struct ext4_iloc iloc;
3014         int err = 0;
3015
3016         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
3017                 return 0;
3018
3019         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
3020                      !inode_is_locked(inode));
3021         /* Do this quick check before taking global s_orphan_lock. */
3022         if (list_empty(&ei->i_orphan))
3023                 return 0;
3024
3025         if (handle) {
3026                 /* Grab inode buffer early before taking global s_orphan_lock */
3027                 err = ext4_reserve_inode_write(handle, inode, &iloc);
3028         }
3029
3030         mutex_lock(&sbi->s_orphan_lock);
3031         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
3032
3033         prev = ei->i_orphan.prev;
3034         list_del_init(&ei->i_orphan);
3035
3036         /* If we're on an error path, we may not have a valid
3037          * transaction handle with which to update the orphan list on
3038          * disk, but we still need to remove the inode from the linked
3039          * list in memory. */
3040         if (!handle || err) {
3041                 mutex_unlock(&sbi->s_orphan_lock);
3042                 goto out_err;
3043         }
3044
3045         ino_next = NEXT_ORPHAN(inode);
3046         if (prev == &sbi->s_orphan) {
3047                 jbd_debug(4, "superblock will point to %u\n", ino_next);
3048                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
3049                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
3050                 if (err) {
3051                         mutex_unlock(&sbi->s_orphan_lock);
3052                         goto out_brelse;
3053                 }
3054                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
3055                 mutex_unlock(&sbi->s_orphan_lock);
3056                 err = ext4_handle_dirty_super(handle, inode->i_sb);
3057         } else {
3058                 struct ext4_iloc iloc2;
3059                 struct inode *i_prev =
3060                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
3061
3062                 jbd_debug(4, "orphan inode %lu will point to %u\n",
3063                           i_prev->i_ino, ino_next);
3064                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
3065                 if (err) {
3066                         mutex_unlock(&sbi->s_orphan_lock);
3067                         goto out_brelse;
3068                 }
3069                 NEXT_ORPHAN(i_prev) = ino_next;
3070                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
3071                 mutex_unlock(&sbi->s_orphan_lock);
3072         }
3073         if (err)
3074                 goto out_brelse;
3075         NEXT_ORPHAN(inode) = 0;
3076         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
3077 out_err:
3078         ext4_std_error(inode->i_sb, err);
3079         return err;
3080
3081 out_brelse:
3082         brelse(iloc.bh);
3083         goto out_err;
3084 }
3085
3086 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3087 {
3088         int retval;
3089         struct inode *inode;
3090         struct buffer_head *bh;
3091         struct ext4_dir_entry_2 *de;
3092         handle_t *handle = NULL;
3093
3094         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3095                 return -EIO;
3096
3097         /* Initialize quotas before so that eventual writes go in
3098          * separate transaction */
3099         retval = dquot_initialize(dir);
3100         if (retval)
3101                 return retval;
3102         retval = dquot_initialize(d_inode(dentry));
3103         if (retval)
3104                 return retval;
3105
3106         retval = -ENOENT;
3107         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3108         if (IS_ERR(bh))
3109                 return PTR_ERR(bh);
3110         if (!bh)
3111                 goto end_rmdir;
3112
3113         inode = d_inode(dentry);
3114
3115         retval = -EFSCORRUPTED;
3116         if (le32_to_cpu(de->inode) != inode->i_ino)
3117                 goto end_rmdir;
3118
3119         retval = -ENOTEMPTY;
3120         if (!ext4_empty_dir(inode))
3121                 goto end_rmdir;
3122
3123         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3124                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3125         if (IS_ERR(handle)) {
3126                 retval = PTR_ERR(handle);
3127                 handle = NULL;
3128                 goto end_rmdir;
3129         }
3130
3131         if (IS_DIRSYNC(dir))
3132                 ext4_handle_sync(handle);
3133
3134         retval = ext4_delete_entry(handle, dir, de, bh);
3135         if (retval)
3136                 goto end_rmdir;
3137         if (!EXT4_DIR_LINK_EMPTY(inode))
3138                 ext4_warning_inode(inode,
3139                              "empty directory '%.*s' has too many links (%u)",
3140                              dentry->d_name.len, dentry->d_name.name,
3141                              inode->i_nlink);
3142         inode_inc_iversion(inode);
3143         clear_nlink(inode);
3144         /* There's no need to set i_disksize: the fact that i_nlink is
3145          * zero will ensure that the right thing happens during any
3146          * recovery. */
3147         inode->i_size = 0;
3148         ext4_orphan_add(handle, inode);
3149         inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
3150         ext4_mark_inode_dirty(handle, inode);
3151         ext4_dec_count(handle, dir);
3152         ext4_update_dx_flag(dir);
3153         ext4_mark_inode_dirty(handle, dir);
3154
3155 #ifdef CONFIG_UNICODE
3156         /* VFS negative dentries are incompatible with Encoding and
3157          * Case-insensitiveness. Eventually we'll want avoid
3158          * invalidating the dentries here, alongside with returning the
3159          * negative dentries at ext4_lookup(), when it is better
3160          * supported by the VFS for the CI case.
3161          */
3162         if (IS_CASEFOLDED(dir))
3163                 d_invalidate(dentry);
3164 #endif
3165
3166 end_rmdir:
3167         brelse(bh);
3168         if (handle)
3169                 ext4_journal_stop(handle);
3170         return retval;
3171 }
3172
3173 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3174 {
3175         int retval;
3176         struct inode *inode;
3177         struct buffer_head *bh;
3178         struct ext4_dir_entry_2 *de;
3179         handle_t *handle = NULL;
3180
3181         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3182                 return -EIO;
3183
3184         trace_ext4_unlink_enter(dir, dentry);
3185         /* Initialize quotas before so that eventual writes go
3186          * in separate transaction */
3187         retval = dquot_initialize(dir);
3188         if (retval)
3189                 return retval;
3190         retval = dquot_initialize(d_inode(dentry));
3191         if (retval)
3192                 return retval;
3193
3194         retval = -ENOENT;
3195         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3196         if (IS_ERR(bh))
3197                 return PTR_ERR(bh);
3198         if (!bh)
3199                 goto end_unlink;
3200
3201         inode = d_inode(dentry);
3202
3203         retval = -EFSCORRUPTED;
3204         if (le32_to_cpu(de->inode) != inode->i_ino)
3205                 goto end_unlink;
3206
3207         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3208                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3209         if (IS_ERR(handle)) {
3210                 retval = PTR_ERR(handle);
3211                 handle = NULL;
3212                 goto end_unlink;
3213         }
3214
3215         if (IS_DIRSYNC(dir))
3216                 ext4_handle_sync(handle);
3217
3218         retval = ext4_delete_entry(handle, dir, de, bh);
3219         if (retval)
3220                 goto end_unlink;
3221         dir->i_ctime = dir->i_mtime = current_time(dir);
3222         ext4_update_dx_flag(dir);
3223         ext4_mark_inode_dirty(handle, dir);
3224         if (inode->i_nlink == 0)
3225                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3226                                    dentry->d_name.len, dentry->d_name.name);
3227         else
3228                 drop_nlink(inode);
3229         if (!inode->i_nlink)
3230                 ext4_orphan_add(handle, inode);
3231         inode->i_ctime = current_time(inode);
3232         ext4_mark_inode_dirty(handle, inode);
3233
3234 #ifdef CONFIG_UNICODE
3235         /* VFS negative dentries are incompatible with Encoding and
3236          * Case-insensitiveness. Eventually we'll want avoid
3237          * invalidating the dentries here, alongside with returning the
3238          * negative dentries at ext4_lookup(), when it is  better
3239          * supported by the VFS for the CI case.
3240          */
3241         if (IS_CASEFOLDED(dir))
3242                 d_invalidate(dentry);
3243 #endif
3244
3245 end_unlink:
3246         brelse(bh);
3247         if (handle)
3248                 ext4_journal_stop(handle);
3249         trace_ext4_unlink_exit(dentry, retval);
3250         return retval;
3251 }
3252
3253 static int ext4_symlink(struct inode *dir,
3254                         struct dentry *dentry, const char *symname)
3255 {
3256         handle_t *handle;
3257         struct inode *inode;
3258         int err, len = strlen(symname);
3259         int credits;
3260         struct fscrypt_str disk_link;
3261
3262         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3263                 return -EIO;
3264
3265         err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3266                                       &disk_link);
3267         if (err)
3268                 return err;
3269
3270         err = dquot_initialize(dir);
3271         if (err)
3272                 return err;
3273
3274         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3275                 /*
3276                  * For non-fast symlinks, we just allocate inode and put it on
3277                  * orphan list in the first transaction => we need bitmap,
3278                  * group descriptor, sb, inode block, quota blocks, and
3279                  * possibly selinux xattr blocks.
3280                  */
3281                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3282                           EXT4_XATTR_TRANS_BLOCKS;
3283         } else {
3284                 /*
3285                  * Fast symlink. We have to add entry to directory
3286                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3287                  * allocate new inode (bitmap, group descriptor, inode block,
3288                  * quota blocks, sb is already counted in previous macros).
3289                  */
3290                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3291                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3292         }
3293
3294         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3295                                             &dentry->d_name, 0, NULL,
3296                                             EXT4_HT_DIR, credits);
3297         handle = ext4_journal_current_handle();
3298         if (IS_ERR(inode)) {
3299                 if (handle)
3300                         ext4_journal_stop(handle);
3301                 return PTR_ERR(inode);
3302         }
3303
3304         if (IS_ENCRYPTED(inode)) {
3305                 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3306                 if (err)
3307                         goto err_drop_inode;
3308                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3309         }
3310
3311         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3312                 if (!IS_ENCRYPTED(inode))
3313                         inode->i_op = &ext4_symlink_inode_operations;
3314                 inode_nohighmem(inode);
3315                 ext4_set_aops(inode);
3316                 /*
3317                  * We cannot call page_symlink() with transaction started
3318                  * because it calls into ext4_write_begin() which can wait
3319                  * for transaction commit if we are running out of space
3320                  * and thus we deadlock. So we have to stop transaction now
3321                  * and restart it when symlink contents is written.
3322                  *
3323                  * To keep fs consistent in case of crash, we have to put inode
3324                  * to orphan list in the mean time.
3325                  */
3326                 drop_nlink(inode);
3327                 err = ext4_orphan_add(handle, inode);
3328                 ext4_journal_stop(handle);
3329                 handle = NULL;
3330                 if (err)
3331                         goto err_drop_inode;
3332                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3333                 if (err)
3334                         goto err_drop_inode;
3335                 /*
3336                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3337                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3338                  */
3339                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3340                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3341                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3342                 if (IS_ERR(handle)) {
3343                         err = PTR_ERR(handle);
3344                         handle = NULL;
3345                         goto err_drop_inode;
3346                 }
3347                 set_nlink(inode, 1);
3348                 err = ext4_orphan_del(handle, inode);
3349                 if (err)
3350                         goto err_drop_inode;
3351         } else {
3352                 /* clear the extent format for fast symlink */
3353                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3354                 if (!IS_ENCRYPTED(inode)) {
3355                         inode->i_op = &ext4_fast_symlink_inode_operations;
3356                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3357                 }
3358                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3359                        disk_link.len);
3360                 inode->i_size = disk_link.len - 1;
3361         }
3362         EXT4_I(inode)->i_disksize = inode->i_size;
3363         err = ext4_add_nondir(handle, dentry, &inode);
3364         if (handle)
3365                 ext4_journal_stop(handle);
3366         if (inode)
3367                 iput(inode);
3368         goto out_free_encrypted_link;
3369
3370 err_drop_inode:
3371         if (handle)
3372                 ext4_journal_stop(handle);
3373         clear_nlink(inode);
3374         unlock_new_inode(inode);
3375         iput(inode);
3376 out_free_encrypted_link:
3377         if (disk_link.name != (unsigned char *)symname)
3378                 kfree(disk_link.name);
3379         return err;
3380 }
3381
3382 static int ext4_link(struct dentry *old_dentry,
3383                      struct inode *dir, struct dentry *dentry)
3384 {
3385         handle_t *handle;
3386         struct inode *inode = d_inode(old_dentry);
3387         int err, retries = 0;
3388
3389         if (inode->i_nlink >= EXT4_LINK_MAX)
3390                 return -EMLINK;
3391
3392         err = fscrypt_prepare_link(old_dentry, dir, dentry);
3393         if (err)
3394                 return err;
3395
3396         if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3397             (!projid_eq(EXT4_I(dir)->i_projid,
3398                         EXT4_I(old_dentry->d_inode)->i_projid)))
3399                 return -EXDEV;
3400
3401         err = dquot_initialize(dir);
3402         if (err)
3403                 return err;
3404
3405 retry:
3406         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3407                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3408                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3409         if (IS_ERR(handle))
3410                 return PTR_ERR(handle);
3411
3412         if (IS_DIRSYNC(dir))
3413                 ext4_handle_sync(handle);
3414
3415         inode->i_ctime = current_time(inode);
3416         ext4_inc_count(handle, inode);
3417         ihold(inode);
3418
3419         err = ext4_add_entry(handle, dentry, inode);
3420         if (!err) {
3421                 ext4_mark_inode_dirty(handle, inode);
3422                 /* this can happen only for tmpfile being
3423                  * linked the first time
3424                  */
3425                 if (inode->i_nlink == 1)
3426                         ext4_orphan_del(handle, inode);
3427                 d_instantiate(dentry, inode);
3428         } else {
3429                 drop_nlink(inode);
3430                 iput(inode);
3431         }
3432         ext4_journal_stop(handle);
3433         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3434                 goto retry;
3435         return err;
3436 }
3437
3438
3439 /*
3440  * Try to find buffer head where contains the parent block.
3441  * It should be the inode block if it is inlined or the 1st block
3442  * if it is a normal dir.
3443  */
3444 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3445                                         struct inode *inode,
3446                                         int *retval,
3447                                         struct ext4_dir_entry_2 **parent_de,
3448                                         int *inlined)
3449 {
3450         struct buffer_head *bh;
3451
3452         if (!ext4_has_inline_data(inode)) {
3453                 /* The first directory block must not be a hole, so
3454                  * treat it as DIRENT_HTREE
3455                  */
3456                 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
3457                 if (IS_ERR(bh)) {
3458                         *retval = PTR_ERR(bh);
3459                         return NULL;
3460                 }
3461                 *parent_de = ext4_next_entry(
3462                                         (struct ext4_dir_entry_2 *)bh->b_data,
3463                                         inode->i_sb->s_blocksize);
3464                 return bh;
3465         }
3466
3467         *inlined = 1;
3468         return ext4_get_first_inline_block(inode, parent_de, retval);
3469 }
3470
3471 struct ext4_renament {
3472         struct inode *dir;
3473         struct dentry *dentry;
3474         struct inode *inode;
3475         bool is_dir;
3476         int dir_nlink_delta;
3477
3478         /* entry for "dentry" */
3479         struct buffer_head *bh;
3480         struct ext4_dir_entry_2 *de;
3481         int inlined;
3482
3483         /* entry for ".." in inode if it's a directory */
3484         struct buffer_head *dir_bh;
3485         struct ext4_dir_entry_2 *parent_de;
3486         int dir_inlined;
3487 };
3488
3489 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3490 {
3491         int retval;
3492
3493         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3494                                               &retval, &ent->parent_de,
3495                                               &ent->dir_inlined);
3496         if (!ent->dir_bh)
3497                 return retval;
3498         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3499                 return -EFSCORRUPTED;
3500         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3501         return ext4_journal_get_write_access(handle, ent->dir_bh);
3502 }
3503
3504 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3505                                   unsigned dir_ino)
3506 {
3507         int retval;
3508
3509         ent->parent_de->inode = cpu_to_le32(dir_ino);
3510         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3511         if (!ent->dir_inlined) {
3512                 if (is_dx(ent->inode)) {
3513                         retval = ext4_handle_dirty_dx_node(handle,
3514                                                            ent->inode,
3515                                                            ent->dir_bh);
3516                 } else {
3517                         retval = ext4_handle_dirty_dirblock(handle, ent->inode,
3518                                                             ent->dir_bh);
3519                 }
3520         } else {
3521                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3522         }
3523         if (retval) {
3524                 ext4_std_error(ent->dir->i_sb, retval);
3525                 return retval;
3526         }
3527         return 0;
3528 }
3529
3530 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3531                        unsigned ino, unsigned file_type)
3532 {
3533         int retval;
3534
3535         BUFFER_TRACE(ent->bh, "get write access");
3536         retval = ext4_journal_get_write_access(handle, ent->bh);
3537         if (retval)
3538                 return retval;
3539         ent->de->inode = cpu_to_le32(ino);
3540         if (ext4_has_feature_filetype(ent->dir->i_sb))
3541                 ent->de->file_type = file_type;
3542         inode_inc_iversion(ent->dir);
3543         ent->dir->i_ctime = ent->dir->i_mtime =
3544                 current_time(ent->dir);
3545         ext4_mark_inode_dirty(handle, ent->dir);
3546         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3547         if (!ent->inlined) {
3548                 retval = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh);
3549                 if (unlikely(retval)) {
3550                         ext4_std_error(ent->dir->i_sb, retval);
3551                         return retval;
3552                 }
3553         }
3554         brelse(ent->bh);
3555         ent->bh = NULL;
3556
3557         return 0;
3558 }
3559
3560 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3561                                   const struct qstr *d_name)
3562 {
3563         int retval = -ENOENT;
3564         struct buffer_head *bh;
3565         struct ext4_dir_entry_2 *de;
3566
3567         bh = ext4_find_entry(dir, d_name, &de, NULL);
3568         if (IS_ERR(bh))
3569                 return PTR_ERR(bh);
3570         if (bh) {
3571                 retval = ext4_delete_entry(handle, dir, de, bh);
3572                 brelse(bh);
3573         }
3574         return retval;
3575 }
3576
3577 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3578                                int force_reread)
3579 {
3580         int retval;
3581         /*
3582          * ent->de could have moved from under us during htree split, so make
3583          * sure that we are deleting the right entry.  We might also be pointing
3584          * to a stale entry in the unused part of ent->bh so just checking inum
3585          * and the name isn't enough.
3586          */
3587         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3588             ent->de->name_len != ent->dentry->d_name.len ||
3589             strncmp(ent->de->name, ent->dentry->d_name.name,
3590                     ent->de->name_len) ||
3591             force_reread) {
3592                 retval = ext4_find_delete_entry(handle, ent->dir,
3593                                                 &ent->dentry->d_name);
3594         } else {
3595                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3596                 if (retval == -ENOENT) {
3597                         retval = ext4_find_delete_entry(handle, ent->dir,
3598                                                         &ent->dentry->d_name);
3599                 }
3600         }
3601
3602         if (retval) {
3603                 ext4_warning_inode(ent->dir,
3604                                    "Deleting old file: nlink %d, error=%d",
3605                                    ent->dir->i_nlink, retval);
3606         }
3607 }
3608
3609 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3610 {
3611         if (ent->dir_nlink_delta) {
3612                 if (ent->dir_nlink_delta == -1)
3613                         ext4_dec_count(handle, ent->dir);
3614                 else
3615                         ext4_inc_count(handle, ent->dir);
3616                 ext4_mark_inode_dirty(handle, ent->dir);
3617         }
3618 }
3619
3620 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3621                                               int credits, handle_t **h)
3622 {
3623         struct inode *wh;
3624         handle_t *handle;
3625         int retries = 0;
3626
3627         /*
3628          * for inode block, sb block, group summaries,
3629          * and inode bitmap
3630          */
3631         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3632                     EXT4_XATTR_TRANS_BLOCKS + 4);
3633 retry:
3634         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3635                                          &ent->dentry->d_name, 0, NULL,
3636                                          EXT4_HT_DIR, credits);
3637
3638         handle = ext4_journal_current_handle();
3639         if (IS_ERR(wh)) {
3640                 if (handle)
3641                         ext4_journal_stop(handle);
3642                 if (PTR_ERR(wh) == -ENOSPC &&
3643                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3644                         goto retry;
3645         } else {
3646                 *h = handle;
3647                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3648                 wh->i_op = &ext4_special_inode_operations;
3649         }
3650         return wh;
3651 }
3652
3653 /*
3654  * Anybody can rename anything with this: the permission checks are left to the
3655  * higher-level routines.
3656  *
3657  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3658  * while new_{dentry,inode) refers to the destination dentry/inode
3659  * This comes from rename(const char *oldpath, const char *newpath)
3660  */
3661 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3662                        struct inode *new_dir, struct dentry *new_dentry,
3663                        unsigned int flags)
3664 {
3665         handle_t *handle = NULL;
3666         struct ext4_renament old = {
3667                 .dir = old_dir,
3668                 .dentry = old_dentry,
3669                 .inode = d_inode(old_dentry),
3670         };
3671         struct ext4_renament new = {
3672                 .dir = new_dir,
3673                 .dentry = new_dentry,
3674                 .inode = d_inode(new_dentry),
3675         };
3676         int force_reread;
3677         int retval;
3678         struct inode *whiteout = NULL;
3679         int credits;
3680         u8 old_file_type;
3681
3682         if (new.inode && new.inode->i_nlink == 0) {
3683                 EXT4_ERROR_INODE(new.inode,
3684                                  "target of rename is already freed");
3685                 return -EFSCORRUPTED;
3686         }
3687
3688         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3689             (!projid_eq(EXT4_I(new_dir)->i_projid,
3690                         EXT4_I(old_dentry->d_inode)->i_projid)))
3691                 return -EXDEV;
3692
3693         retval = dquot_initialize(old.dir);
3694         if (retval)
3695                 return retval;
3696         retval = dquot_initialize(new.dir);
3697         if (retval)
3698                 return retval;
3699
3700         /* Initialize quotas before so that eventual writes go
3701          * in separate transaction */
3702         if (new.inode) {
3703                 retval = dquot_initialize(new.inode);
3704                 if (retval)
3705                         return retval;
3706         }
3707
3708         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3709         if (IS_ERR(old.bh))
3710                 return PTR_ERR(old.bh);
3711         /*
3712          *  Check for inode number is _not_ due to possible IO errors.
3713          *  We might rmdir the source, keep it as pwd of some process
3714          *  and merrily kill the link to whatever was created under the
3715          *  same name. Goodbye sticky bit ;-<
3716          */
3717         retval = -ENOENT;
3718         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3719                 goto end_rename;
3720
3721         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3722                                  &new.de, &new.inlined);
3723         if (IS_ERR(new.bh)) {
3724                 retval = PTR_ERR(new.bh);
3725                 new.bh = NULL;
3726                 goto end_rename;
3727         }
3728         if (new.bh) {
3729                 if (!new.inode) {
3730                         brelse(new.bh);
3731                         new.bh = NULL;
3732                 }
3733         }
3734         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3735                 ext4_alloc_da_blocks(old.inode);
3736
3737         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3738                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3739         if (!(flags & RENAME_WHITEOUT)) {
3740                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3741                 if (IS_ERR(handle)) {
3742                         retval = PTR_ERR(handle);
3743                         handle = NULL;
3744                         goto end_rename;
3745                 }
3746         } else {
3747                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3748                 if (IS_ERR(whiteout)) {
3749                         retval = PTR_ERR(whiteout);
3750                         whiteout = NULL;
3751                         goto end_rename;
3752                 }
3753         }
3754
3755         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3756                 ext4_handle_sync(handle);
3757
3758         if (S_ISDIR(old.inode->i_mode)) {
3759                 if (new.inode) {
3760                         retval = -ENOTEMPTY;
3761                         if (!ext4_empty_dir(new.inode))
3762                                 goto end_rename;
3763                 } else {
3764                         retval = -EMLINK;
3765                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3766                                 goto end_rename;
3767                 }
3768                 retval = ext4_rename_dir_prepare(handle, &old);
3769                 if (retval)
3770                         goto end_rename;
3771         }
3772         /*
3773          * If we're renaming a file within an inline_data dir and adding or
3774          * setting the new dirent causes a conversion from inline_data to
3775          * extents/blockmap, we need to force the dirent delete code to
3776          * re-read the directory, or else we end up trying to delete a dirent
3777          * from what is now the extent tree root (or a block map).
3778          */
3779         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3780                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3781
3782         old_file_type = old.de->file_type;
3783         if (whiteout) {
3784                 /*
3785                  * Do this before adding a new entry, so the old entry is sure
3786                  * to be still pointing to the valid old entry.
3787                  */
3788                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3789                                      EXT4_FT_CHRDEV);
3790                 if (retval)
3791                         goto end_rename;
3792                 ext4_mark_inode_dirty(handle, whiteout);
3793         }
3794         if (!new.bh) {
3795                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3796                 if (retval)
3797                         goto end_rename;
3798         } else {
3799                 retval = ext4_setent(handle, &new,
3800                                      old.inode->i_ino, old_file_type);
3801                 if (retval)
3802                         goto end_rename;
3803         }
3804         if (force_reread)
3805                 force_reread = !ext4_test_inode_flag(new.dir,
3806                                                      EXT4_INODE_INLINE_DATA);
3807
3808         /*
3809          * Like most other Unix systems, set the ctime for inodes on a
3810          * rename.
3811          */
3812         old.inode->i_ctime = current_time(old.inode);
3813         ext4_mark_inode_dirty(handle, old.inode);
3814
3815         if (!whiteout) {
3816                 /*
3817                  * ok, that's it
3818                  */
3819                 ext4_rename_delete(handle, &old, force_reread);
3820         }
3821
3822         if (new.inode) {
3823                 ext4_dec_count(handle, new.inode);
3824                 new.inode->i_ctime = current_time(new.inode);
3825         }
3826         old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
3827         ext4_update_dx_flag(old.dir);
3828         if (old.dir_bh) {
3829                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3830                 if (retval)
3831                         goto end_rename;
3832
3833                 ext4_dec_count(handle, old.dir);
3834                 if (new.inode) {
3835                         /* checked ext4_empty_dir above, can't have another
3836                          * parent, ext4_dec_count() won't work for many-linked
3837                          * dirs */
3838                         clear_nlink(new.inode);
3839                 } else {
3840                         ext4_inc_count(handle, new.dir);
3841                         ext4_update_dx_flag(new.dir);
3842                         ext4_mark_inode_dirty(handle, new.dir);
3843                 }
3844         }
3845         ext4_mark_inode_dirty(handle, old.dir);
3846         if (new.inode) {
3847                 ext4_mark_inode_dirty(handle, new.inode);
3848                 if (!new.inode->i_nlink)
3849                         ext4_orphan_add(handle, new.inode);
3850         }
3851         retval = 0;
3852
3853 end_rename:
3854         brelse(old.dir_bh);
3855         brelse(old.bh);
3856         brelse(new.bh);
3857         if (whiteout) {
3858                 if (retval)
3859                         drop_nlink(whiteout);
3860                 unlock_new_inode(whiteout);
3861                 iput(whiteout);
3862         }
3863         if (handle)
3864                 ext4_journal_stop(handle);
3865         return retval;
3866 }
3867
3868 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3869                              struct inode *new_dir, struct dentry *new_dentry)
3870 {
3871         handle_t *handle = NULL;
3872         struct ext4_renament old = {
3873                 .dir = old_dir,
3874                 .dentry = old_dentry,
3875                 .inode = d_inode(old_dentry),
3876         };
3877         struct ext4_renament new = {
3878                 .dir = new_dir,
3879                 .dentry = new_dentry,
3880                 .inode = d_inode(new_dentry),
3881         };
3882         u8 new_file_type;
3883         int retval;
3884         struct timespec64 ctime;
3885
3886         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3887              !projid_eq(EXT4_I(new_dir)->i_projid,
3888                         EXT4_I(old_dentry->d_inode)->i_projid)) ||
3889             (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3890              !projid_eq(EXT4_I(old_dir)->i_projid,
3891                         EXT4_I(new_dentry->d_inode)->i_projid)))
3892                 return -EXDEV;
3893
3894         retval = dquot_initialize(old.dir);
3895         if (retval)
3896                 return retval;
3897         retval = dquot_initialize(new.dir);
3898         if (retval)
3899                 return retval;
3900
3901         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3902                                  &old.de, &old.inlined);
3903         if (IS_ERR(old.bh))
3904                 return PTR_ERR(old.bh);
3905         /*
3906          *  Check for inode number is _not_ due to possible IO errors.
3907          *  We might rmdir the source, keep it as pwd of some process
3908          *  and merrily kill the link to whatever was created under the
3909          *  same name. Goodbye sticky bit ;-<
3910          */
3911         retval = -ENOENT;
3912         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3913                 goto end_rename;
3914
3915         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3916                                  &new.de, &new.inlined);
3917         if (IS_ERR(new.bh)) {
3918                 retval = PTR_ERR(new.bh);
3919                 new.bh = NULL;
3920                 goto end_rename;
3921         }
3922
3923         /* RENAME_EXCHANGE case: old *and* new must both exist */
3924         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3925                 goto end_rename;
3926
3927         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3928                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3929                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3930         if (IS_ERR(handle)) {
3931                 retval = PTR_ERR(handle);
3932                 handle = NULL;
3933                 goto end_rename;
3934         }
3935
3936         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3937                 ext4_handle_sync(handle);
3938
3939         if (S_ISDIR(old.inode->i_mode)) {
3940                 old.is_dir = true;
3941                 retval = ext4_rename_dir_prepare(handle, &old);
3942                 if (retval)
3943                         goto end_rename;
3944         }
3945         if (S_ISDIR(new.inode->i_mode)) {
3946                 new.is_dir = true;
3947                 retval = ext4_rename_dir_prepare(handle, &new);
3948                 if (retval)
3949                         goto end_rename;
3950         }
3951
3952         /*
3953          * Other than the special case of overwriting a directory, parents'
3954          * nlink only needs to be modified if this is a cross directory rename.
3955          */
3956         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3957                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3958                 new.dir_nlink_delta = -old.dir_nlink_delta;
3959                 retval = -EMLINK;
3960                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3961                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3962                         goto end_rename;
3963         }
3964
3965         new_file_type = new.de->file_type;
3966         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3967         if (retval)
3968                 goto end_rename;
3969
3970         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3971         if (retval)
3972                 goto end_rename;
3973
3974         /*
3975          * Like most other Unix systems, set the ctime for inodes on a
3976          * rename.
3977          */
3978         ctime = current_time(old.inode);
3979         old.inode->i_ctime = ctime;
3980         new.inode->i_ctime = ctime;
3981         ext4_mark_inode_dirty(handle, old.inode);
3982         ext4_mark_inode_dirty(handle, new.inode);
3983
3984         if (old.dir_bh) {
3985                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3986                 if (retval)
3987                         goto end_rename;
3988         }
3989         if (new.dir_bh) {
3990                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3991                 if (retval)
3992                         goto end_rename;
3993         }
3994         ext4_update_dir_count(handle, &old);
3995         ext4_update_dir_count(handle, &new);
3996         retval = 0;
3997
3998 end_rename:
3999         brelse(old.dir_bh);
4000         brelse(new.dir_bh);
4001         brelse(old.bh);
4002         brelse(new.bh);
4003         if (handle)
4004                 ext4_journal_stop(handle);
4005         return retval;
4006 }
4007
4008 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
4009                         struct inode *new_dir, struct dentry *new_dentry,
4010                         unsigned int flags)
4011 {
4012         int err;
4013
4014         if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
4015                 return -EIO;
4016
4017         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
4018                 return -EINVAL;
4019
4020         err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
4021                                      flags);
4022         if (err)
4023                 return err;
4024
4025         if (flags & RENAME_EXCHANGE) {
4026                 return ext4_cross_rename(old_dir, old_dentry,
4027                                          new_dir, new_dentry);
4028         }
4029
4030         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
4031 }
4032
4033 /*
4034  * directories can handle most operations...
4035  */
4036 const struct inode_operations ext4_dir_inode_operations = {
4037         .create         = ext4_create,
4038         .lookup         = ext4_lookup,
4039         .link           = ext4_link,
4040         .unlink         = ext4_unlink,
4041         .symlink        = ext4_symlink,
4042         .mkdir          = ext4_mkdir,
4043         .rmdir          = ext4_rmdir,
4044         .mknod          = ext4_mknod,
4045         .tmpfile        = ext4_tmpfile,
4046         .rename         = ext4_rename2,
4047         .setattr        = ext4_setattr,
4048         .getattr        = ext4_getattr,
4049         .listxattr      = ext4_listxattr,
4050         .get_acl        = ext4_get_acl,
4051         .set_acl        = ext4_set_acl,
4052         .fiemap         = ext4_fiemap,
4053 };
4054
4055 const struct inode_operations ext4_special_inode_operations = {
4056         .setattr        = ext4_setattr,
4057         .getattr        = ext4_getattr,
4058         .listxattr      = ext4_listxattr,
4059         .get_acl        = ext4_get_acl,
4060         .set_acl        = ext4_set_acl,
4061 };