fs/ext4/namei.c

   1 /*
   2  *  linux/fs/ext4/namei.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/namei.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  *  Directory entry file type support and forward compatibility hooks
  18  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  19  *  Hash Tree Directory indexing (c)
  20  *      Daniel Phillips, 2001
  21  *  Hash Tree Directory indexing porting
  22  *      Christopher Li, 2002
  23  *  Hash Tree Directory indexing cleanup
  24  *      Theodore Ts'o, 2002
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/time.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/stat.h>
  32 #include <linux/string.h>
  33 #include <linux/quotaops.h>
  34 #include <linux/buffer_head.h>
  35 #include <linux/bio.h>
  36 #include "ext4.h"
  37 #include "ext4_jbd2.h"
  38
  39 #include "xattr.h"
  40 #include "acl.h"
  41
  42 #include <trace/events/ext4.h>
  43 /*
  44  * define how far ahead to read directories while searching them.
  45  */
  46 #define NAMEI_RA_CHUNKS  2
  47 #define NAMEI_RA_BLOCKS  4
  48 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  49
  50 static struct buffer_head *ext4_append(handle_t *handle,
  51                                         struct inode *inode,
  52                                         ext4_lblk_t *block)
  53 {
  54         struct buffer_head *bh;
  55         int err;
  56
  57         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  58                      ((inode->i_size >> 10) >=
  59                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
  60                 return ERR_PTR(-ENOSPC);
  61
  62         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  63
  64         bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
  65         if (IS_ERR(bh))
  66                 return bh;
  67         inode->i_size += inode->i_sb->s_blocksize;
  68         EXT4_I(inode)->i_disksize = inode->i_size;
  69         BUFFER_TRACE(bh, "get_write_access");
  70         err = ext4_journal_get_write_access(handle, bh);
  71         if (err) {
  72                 brelse(bh);
  73                 ext4_std_error(inode->i_sb, err);
  74                 return ERR_PTR(err);
  75         }
  76         return bh;
  77 }
  78
  79 static int ext4_dx_csum_verify(struct inode *inode,
  80                                struct ext4_dir_entry *dirent);
  81
  82 typedef enum {
  83         EITHER, INDEX, DIRENT
  84 } dirblock_type_t;
  85
  86 #define ext4_read_dirblock(inode, block, type) \
  87         __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
  88
  89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
  90                                                 ext4_lblk_t block,
  91                                                 dirblock_type_t type,
  92                                                 const char *func,
  93                                                 unsigned int line)
  94 {
  95         struct buffer_head *bh;
  96         struct ext4_dir_entry *dirent;
  97         int is_dx_block = 0;
  98
  99         bh = ext4_bread(NULL, inode, block, 0);
 100         if (IS_ERR(bh)) {
 101                 __ext4_warning(inode->i_sb, func, line,
 102                                "inode #%lu: lblock %lu: comm %s: "
 103                                "error %ld reading directory block",
 104                                inode->i_ino, (unsigned long)block,
 105                                current->comm, PTR_ERR(bh));
 106
 107                 return bh;
 108         }
 109         if (!bh) {
 110                 ext4_error_inode(inode, func, line, block,
 111                                  "Directory hole found");
 112                 return ERR_PTR(-EFSCORRUPTED);
 113         }
 114         dirent = (struct ext4_dir_entry *) bh->b_data;
 115         /* Determine whether or not we have an index block */
 116         if (is_dx(inode)) {
 117                 if (block == 0)
 118                         is_dx_block = 1;
 119                 else if (ext4_rec_len_from_disk(dirent->rec_len,
 120                                                 inode->i_sb->s_blocksize) ==
 121                          inode->i_sb->s_blocksize)
 122                         is_dx_block = 1;
 123         }
 124         if (!is_dx_block && type == INDEX) {
 125                 ext4_error_inode(inode, func, line, block,
 126                        "directory leaf block found instead of index block");
 127                 return ERR_PTR(-EFSCORRUPTED);
 128         }
 129         if (!ext4_has_metadata_csum(inode->i_sb) ||
 130             buffer_verified(bh))
 131                 return bh;
 132
 133         /*
 134          * An empty leaf block can get mistaken for a index block; for
 135          * this reason, we can only check the index checksum when the
 136          * caller is sure it should be an index block.
 137          */
 138         if (is_dx_block && type == INDEX) {
 139                 if (ext4_dx_csum_verify(inode, dirent))
 140                         set_buffer_verified(bh);
 141                 else {
 142                         ext4_error_inode(inode, func, line, block,
 143                                          "Directory index failed checksum");
 144                         brelse(bh);
 145                         return ERR_PTR(-EFSBADCRC);
 146                 }
 147         }
 148         if (!is_dx_block) {
 149                 if (ext4_dirent_csum_verify(inode, dirent))
 150                         set_buffer_verified(bh);
 151                 else {
 152                         ext4_error_inode(inode, func, line, block,
 153                                          "Directory block failed checksum");
 154                         brelse(bh);
 155                         return ERR_PTR(-EFSBADCRC);
 156                 }
 157         }
 158         return bh;
 159 }
 160
 161 #ifndef assert
 162 #define assert(test) J_ASSERT(test)
 163 #endif
 164
 165 #ifdef DX_DEBUG
 166 #define dxtrace(command) command
 167 #else
 168 #define dxtrace(command)
 169 #endif
 170
 171 struct fake_dirent
 172 {
 173         __le32 inode;
 174         __le16 rec_len;
 175         u8 name_len;
 176         u8 file_type;
 177 };
 178
 179 struct dx_countlimit
 180 {
 181         __le16 limit;
 182         __le16 count;
 183 };
 184
 185 struct dx_entry
 186 {
 187         __le32 hash;
 188         __le32 block;
 189 };
 190
 191 /*
 192  * dx_root_info is laid out so that if it should somehow get overlaid by a
 193  * dirent the two low bits of the hash version will be zero.  Therefore, the
 194  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 195  */
 196
 197 struct dx_root
 198 {
 199         struct fake_dirent dot;
 200         char dot_name[4];
 201         struct fake_dirent dotdot;
 202         char dotdot_name[4];
 203         struct dx_root_info
 204         {
 205                 __le32 reserved_zero;
 206                 u8 hash_version;
 207                 u8 info_length; /* 8 */
 208                 u8 indirect_levels;
 209                 u8 unused_flags;
 210         }
 211         info;
 212         struct dx_entry entries[0];
 213 };
 214
 215 struct dx_node
 216 {
 217         struct fake_dirent fake;
 218         struct dx_entry entries[0];
 219 };
 220
 221
 222 struct dx_frame
 223 {
 224         struct buffer_head *bh;
 225         struct dx_entry *entries;
 226         struct dx_entry *at;
 227 };
 228
 229 struct dx_map_entry
 230 {
 231         u32 hash;
 232         u16 offs;
 233         u16 size;
 234 };
 235
 236 /*
 237  * This goes at the end of each htree block.
 238  */
 239 struct dx_tail {
 240         u32 dt_reserved;
 241         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 242 };
 243
 244 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 245 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 246 static inline unsigned dx_get_hash(struct dx_entry *entry);
 247 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 248 static unsigned dx_get_count(struct dx_entry *entries);
 249 static unsigned dx_get_limit(struct dx_entry *entries);
 250 static void dx_set_count(struct dx_entry *entries, unsigned value);
 251 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 252 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 253 static unsigned dx_node_limit(struct inode *dir);
 254 static struct dx_frame *dx_probe(struct ext4_filename *fname,
 255                                  struct inode *dir,
 256                                  struct dx_hash_info *hinfo,
 257                                  struct dx_frame *frame);
 258 static void dx_release(struct dx_frame *frames);
 259 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 260                        unsigned blocksize, struct dx_hash_info *hinfo,
 261                        struct dx_map_entry map[]);
 262 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 263 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 264                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 265 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 266 static void dx_insert_block(struct dx_frame *frame,
 267                                         u32 hash, ext4_lblk_t block);
 268 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 269                                  struct dx_frame *frame,
 270                                  struct dx_frame *frames,
 271                                  __u32 *start_hash);
 272 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 273                 struct ext4_filename *fname,
 274                 struct ext4_dir_entry_2 **res_dir);
 275 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 276                              struct inode *dir, struct inode *inode);
 277
 278 /* checksumming functions */
 279 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 280                             unsigned int blocksize)
 281 {
 282         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 283         t->det_rec_len = ext4_rec_len_to_disk(
 284                         sizeof(struct ext4_dir_entry_tail), blocksize);
 285         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 286 }
 287
 288 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 289 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 290                                                    struct ext4_dir_entry *de)
 291 {
 292         struct ext4_dir_entry_tail *t;
 293
 294 #ifdef PARANOID
 295         struct ext4_dir_entry *d, *top;
 296
 297         d = de;
 298         top = (struct ext4_dir_entry *)(((void *)de) +
 299                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 300                 sizeof(struct ext4_dir_entry_tail)));
 301         while (d < top && d->rec_len)
 302                 d = (struct ext4_dir_entry *)(((void *)d) +
 303                     le16_to_cpu(d->rec_len));
 304
 305         if (d != top)
 306                 return NULL;
 307
 308         t = (struct ext4_dir_entry_tail *)d;
 309 #else
 310         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 311 #endif
 312
 313         if (t->det_reserved_zero1 ||
 314             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 315             t->det_reserved_zero2 ||
 316             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 317                 return NULL;
 318
 319         return t;
 320 }
 321
 322 static __le32 ext4_dirent_csum(struct inode *inode,
 323                                struct ext4_dir_entry *dirent, int size)
 324 {
 325         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 326         struct ext4_inode_info *ei = EXT4_I(inode);
 327         __u32 csum;
 328
 329         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 330         return cpu_to_le32(csum);
 331 }
 332
 333 #define warn_no_space_for_csum(inode)                                   \
 334         __warn_no_space_for_csum((inode), __func__, __LINE__)
 335
 336 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
 337                                      unsigned int line)
 338 {
 339         __ext4_warning_inode(inode, func, line,
 340                 "No space for directory leaf checksum. Please run e2fsck -D.");
 341 }
 342
 343 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 344 {
 345         struct ext4_dir_entry_tail *t;
 346
 347         if (!ext4_has_metadata_csum(inode->i_sb))
 348                 return 1;
 349
 350         t = get_dirent_tail(inode, dirent);
 351         if (!t) {
 352                 warn_no_space_for_csum(inode);
 353                 return 0;
 354         }
 355
 356         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 357                                                 (void *)t - (void *)dirent))
 358                 return 0;
 359
 360         return 1;
 361 }
 362
 363 static void ext4_dirent_csum_set(struct inode *inode,
 364                                  struct ext4_dir_entry *dirent)
 365 {
 366         struct ext4_dir_entry_tail *t;
 367
 368         if (!ext4_has_metadata_csum(inode->i_sb))
 369                 return;
 370
 371         t = get_dirent_tail(inode, dirent);
 372         if (!t) {
 373                 warn_no_space_for_csum(inode);
 374                 return;
 375         }
 376
 377         t->det_checksum = ext4_dirent_csum(inode, dirent,
 378                                            (void *)t - (void *)dirent);
 379 }
 380
 381 int ext4_handle_dirty_dirent_node(handle_t *handle,
 382                                   struct inode *inode,
 383                                   struct buffer_head *bh)
 384 {
 385         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 386         return ext4_handle_dirty_metadata(handle, inode, bh);
 387 }
 388
 389 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 390                                                struct ext4_dir_entry *dirent,
 391                                                int *offset)
 392 {
 393         struct ext4_dir_entry *dp;
 394         struct dx_root_info *root;
 395         int count_offset;
 396
 397         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 398                 count_offset = 8;
 399         else if (le16_to_cpu(dirent->rec_len) == 12) {
 400                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 401                 if (le16_to_cpu(dp->rec_len) !=
 402                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 403                         return NULL;
 404                 root = (struct dx_root_info *)(((void *)dp + 12));
 405                 if (root->reserved_zero ||
 406                     root->info_length != sizeof(struct dx_root_info))
 407                         return NULL;
 408                 count_offset = 32;
 409         } else
 410                 return NULL;
 411
 412         if (offset)
 413                 *offset = count_offset;
 414         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 415 }
 416
 417 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 418                            int count_offset, int count, struct dx_tail *t)
 419 {
 420         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 421         struct ext4_inode_info *ei = EXT4_I(inode);
 422         __u32 csum;
 423         __le32 save_csum;
 424         int size;
 425
 426         size = count_offset + (count * sizeof(struct dx_entry));
 427         save_csum = t->dt_checksum;
 428         t->dt_checksum = 0;
 429         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 430         csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
 431         t->dt_checksum = save_csum;
 432
 433         return cpu_to_le32(csum);
 434 }
 435
 436 static int ext4_dx_csum_verify(struct inode *inode,
 437                                struct ext4_dir_entry *dirent)
 438 {
 439         struct dx_countlimit *c;
 440         struct dx_tail *t;
 441         int count_offset, limit, count;
 442
 443         if (!ext4_has_metadata_csum(inode->i_sb))
 444                 return 1;
 445
 446         c = get_dx_countlimit(inode, dirent, &count_offset);
 447         if (!c) {
 448                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 449                 return 1;
 450         }
 451         limit = le16_to_cpu(c->limit);
 452         count = le16_to_cpu(c->count);
 453         if (count_offset + (limit * sizeof(struct dx_entry)) >
 454             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 455                 warn_no_space_for_csum(inode);
 456                 return 1;
 457         }
 458         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 459
 460         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 461                                             count, t))
 462                 return 0;
 463         return 1;
 464 }
 465
 466 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 467 {
 468         struct dx_countlimit *c;
 469         struct dx_tail *t;
 470         int count_offset, limit, count;
 471
 472         if (!ext4_has_metadata_csum(inode->i_sb))
 473                 return;
 474
 475         c = get_dx_countlimit(inode, dirent, &count_offset);
 476         if (!c) {
 477                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 478                 return;
 479         }
 480         limit = le16_to_cpu(c->limit);
 481         count = le16_to_cpu(c->count);
 482         if (count_offset + (limit * sizeof(struct dx_entry)) >
 483             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 484                 warn_no_space_for_csum(inode);
 485                 return;
 486         }
 487         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 488
 489         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 490 }
 491
 492 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 493                                             struct inode *inode,
 494                                             struct buffer_head *bh)
 495 {
 496         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 497         return ext4_handle_dirty_metadata(handle, inode, bh);
 498 }
 499
 500 /*
 501  * p is at least 6 bytes before the end of page
 502  */
 503 static inline struct ext4_dir_entry_2 *
 504 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 505 {
 506         return (struct ext4_dir_entry_2 *)((char *)p +
 507                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 508 }
 509
 510 /*
 511  * Future: use high four bits of block for coalesce-on-delete flags
 512  * Mask them off for now.
 513  */
 514
 515 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 516 {
 517         return le32_to_cpu(entry->block) & 0x00ffffff;
 518 }
 519
 520 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 521 {
 522         entry->block = cpu_to_le32(value);
 523 }
 524
 525 static inline unsigned dx_get_hash(struct dx_entry *entry)
 526 {
 527         return le32_to_cpu(entry->hash);
 528 }
 529
 530 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 531 {
 532         entry->hash = cpu_to_le32(value);
 533 }
 534
 535 static inline unsigned dx_get_count(struct dx_entry *entries)
 536 {
 537         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 538 }
 539
 540 static inline unsigned dx_get_limit(struct dx_entry *entries)
 541 {
 542         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 543 }
 544
 545 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 546 {
 547         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 548 }
 549
 550 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 551 {
 552         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 553 }
 554
 555 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 556 {
 557         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 558                 EXT4_DIR_REC_LEN(2) - infosize;
 559
 560         if (ext4_has_metadata_csum(dir->i_sb))
 561                 entry_space -= sizeof(struct dx_tail);
 562         return entry_space / sizeof(struct dx_entry);
 563 }
 564
 565 static inline unsigned dx_node_limit(struct inode *dir)
 566 {
 567         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 568
 569         if (ext4_has_metadata_csum(dir->i_sb))
 570                 entry_space -= sizeof(struct dx_tail);
 571         return entry_space / sizeof(struct dx_entry);
 572 }
 573
 574 /*
 575  * Debug
 576  */
 577 #ifdef DX_DEBUG
 578 static void dx_show_index(char * label, struct dx_entry *entries)
 579 {
 580         int i, n = dx_get_count (entries);
 581         printk(KERN_DEBUG "%s index ", label);
 582         for (i = 0; i < n; i++) {
 583                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 584                                 0, (unsigned long)dx_get_block(entries + i));
 585         }
 586         printk("\n");
 587 }
 588
 589 struct stats
 590 {
 591         unsigned names;
 592         unsigned space;
 593         unsigned bcount;
 594 };
 595
 596 static struct stats dx_show_leaf(struct inode *dir,
 597                                 struct dx_hash_info *hinfo,
 598                                 struct ext4_dir_entry_2 *de,
 599                                 int size, int show_names)
 600 {
 601         unsigned names = 0, space = 0;
 602         char *base = (char *) de;
 603         struct dx_hash_info h = *hinfo;
 604
 605         printk("names: ");
 606         while ((char *) de < base + size)
 607         {
 608                 if (de->inode)
 609                 {
 610                         if (show_names)
 611                         {
 612 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 613                                 int len;
 614                                 char *name;
 615                                 struct ext4_str fname_crypto_str
 616                                         = {.name = NULL, .len = 0};
 617                                 int res = 0;
 618
 619                                 name  = de->name;
 620                                 len = de->name_len;
 621                                 if (ext4_encrypted_inode(inode))
 622                                         res = ext4_get_encryption_info(dir);
 623                                 if (res) {
 624                                         printk(KERN_WARNING "Error setting up"
 625                                                " fname crypto: %d\n", res);
 626                                 }
 627                                 if (ctx == NULL) {
 628                                         /* Directory is not encrypted */
 629                                         ext4fs_dirhash(de->name,
 630                                                 de->name_len, &h);
 631                                         printk("%*.s:(U)%x.%u ", len,
 632                                                name, h.hash,
 633                                                (unsigned) ((char *) de
 634                                                            - base));
 635                                 } else {
 636                                         /* Directory is encrypted */
 637                                         res = ext4_fname_crypto_alloc_buffer(
 638                                                 ctx, de->name_len,
 639                                                 &fname_crypto_str);
 640                                         if (res < 0) {
 641                                                 printk(KERN_WARNING "Error "
 642                                                         "allocating crypto "
 643                                                         "buffer--skipping "
 644                                                         "crypto\n");
 645                                                 ctx = NULL;
 646                                         }
 647                                         res = ext4_fname_disk_to_usr(ctx, NULL, de,
 648                                                         &fname_crypto_str);
 649                                         if (res < 0) {
 650                                                 printk(KERN_WARNING "Error "
 651                                                         "converting filename "
 652                                                         "from disk to usr"
 653                                                         "\n");
 654                                                 name = "??";
 655                                                 len = 2;
 656                                         } else {
 657                                                 name = fname_crypto_str.name;
 658                                                 len = fname_crypto_str.len;
 659                                         }
 660                                         ext4fs_dirhash(de->name, de->name_len,
 661                                                        &h);
 662                                         printk("%*.s:(E)%x.%u ", len, name,
 663                                                h.hash, (unsigned) ((char *) de
 664                                                                    - base));
 665                                         ext4_fname_crypto_free_buffer(
 666                                                 &fname_crypto_str);
 667                                 }
 668 #else
 669                                 int len = de->name_len;
 670                                 char *name = de->name;
 671                                 ext4fs_dirhash(de->name, de->name_len, &h);
 672                                 printk("%*.s:%x.%u ", len, name, h.hash,
 673                                        (unsigned) ((char *) de - base));
 674 #endif
 675                         }
 676                         space += EXT4_DIR_REC_LEN(de->name_len);
 677                         names++;
 678                 }
 679                 de = ext4_next_entry(de, size);
 680         }
 681         printk("(%i)\n", names);
 682         return (struct stats) { names, space, 1 };
 683 }
 684
 685 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 686                              struct dx_entry *entries, int levels)
 687 {
 688         unsigned blocksize = dir->i_sb->s_blocksize;
 689         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 690         unsigned bcount = 0;
 691         struct buffer_head *bh;
 692         printk("%i indexed blocks...\n", count);
 693         for (i = 0; i < count; i++, entries++)
 694         {
 695                 ext4_lblk_t block = dx_get_block(entries);
 696                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 697                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 698                 struct stats stats;
 699                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 700                 bh = ext4_bread(NULL,dir, block, 0);
 701                 if (!bh || IS_ERR(bh))
 702                         continue;
 703                 stats = levels?
 704                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 705                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 706                         bh->b_data, blocksize, 0);
 707                 names += stats.names;
 708                 space += stats.space;
 709                 bcount += stats.bcount;
 710                 brelse(bh);
 711         }
 712         if (bcount)
 713                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 714                        levels ? "" : "   ", names, space/bcount,
 715                        (space/bcount)*100/blocksize);
 716         return (struct stats) { names, space, bcount};
 717 }
 718 #endif /* DX_DEBUG */
 719
 720 /*
 721  * Probe for a directory leaf block to search.
 722  *
 723  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 724  * error in the directory index, and the caller should fall back to
 725  * searching the directory normally.  The callers of dx_probe **MUST**
 726  * check for this error code, and make sure it never gets reflected
 727  * back to userspace.
 728  */
 729 static struct dx_frame *
 730 dx_probe(struct ext4_filename *fname, struct inode *dir,
 731          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 732 {
 733         unsigned count, indirect;
 734         struct dx_entry *at, *entries, *p, *q, *m;
 735         struct dx_root *root;
 736         struct dx_frame *frame = frame_in;
 737         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 738         u32 hash;
 739
 740         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 741         if (IS_ERR(frame->bh))
 742                 return (struct dx_frame *) frame->bh;
 743
 744         root = (struct dx_root *) frame->bh->b_data;
 745         if (root->info.hash_version != DX_HASH_TEA &&
 746             root->info.hash_version != DX_HASH_HALF_MD4 &&
 747             root->info.hash_version != DX_HASH_LEGACY) {
 748                 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
 749                                    root->info.hash_version);
 750                 goto fail;
 751         }
 752         if (fname)
 753                 hinfo = &fname->hinfo;
 754         hinfo->hash_version = root->info.hash_version;
 755         if (hinfo->hash_version <= DX_HASH_TEA)
 756                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 757         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 758         if (fname && fname_name(fname))
 759                 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
 760         hash = hinfo->hash;
 761
 762         if (root->info.unused_flags & 1) {
 763                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
 764                                    root->info.unused_flags);
 765                 goto fail;
 766         }
 767
 768         indirect = root->info.indirect_levels;
 769         if (indirect > 1) {
 770                 ext4_warning_inode(dir, "Unimplemented hash depth: %#06x",
 771                                    root->info.indirect_levels);
 772                 goto fail;
 773         }
 774
 775         entries = (struct dx_entry *)(((char *)&root->info) +
 776                                       root->info.info_length);
 777
 778         if (dx_get_limit(entries) != dx_root_limit(dir,
 779                                                    root->info.info_length)) {
 780                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 781                                    dx_get_limit(entries),
 782                                    dx_root_limit(dir, root->info.info_length));
 783                 goto fail;
 784         }
 785
 786         dxtrace(printk("Look up %x", hash));
 787         while (1) {
 788                 count = dx_get_count(entries);
 789                 if (!count || count > dx_get_limit(entries)) {
 790                         ext4_warning_inode(dir,
 791                                            "dx entry: count %u beyond limit %u",
 792                                            count, dx_get_limit(entries));
 793                         goto fail;
 794                 }
 795
 796                 p = entries + 1;
 797                 q = entries + count - 1;
 798                 while (p <= q) {
 799                         m = p + (q - p) / 2;
 800                         dxtrace(printk("."));
 801                         if (dx_get_hash(m) > hash)
 802                                 q = m - 1;
 803                         else
 804                                 p = m + 1;
 805                 }
 806
 807                 if (0) { // linear search cross check
 808                         unsigned n = count - 1;
 809                         at = entries;
 810                         while (n--)
 811                         {
 812                                 dxtrace(printk(","));
 813                                 if (dx_get_hash(++at) > hash)
 814                                 {
 815                                         at--;
 816                                         break;
 817                                 }
 818                         }
 819                         assert (at == p - 1);
 820                 }
 821
 822                 at = p - 1;
 823                 dxtrace(printk(" %x->%u\n", at == entries ? 0 : dx_get_hash(at),
 824                                dx_get_block(at)));
 825                 frame->entries = entries;
 826                 frame->at = at;
 827                 if (!indirect--)
 828                         return frame;
 829                 frame++;
 830                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 831                 if (IS_ERR(frame->bh)) {
 832                         ret_err = (struct dx_frame *) frame->bh;
 833                         frame->bh = NULL;
 834                         goto fail;
 835                 }
 836                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 837
 838                 if (dx_get_limit(entries) != dx_node_limit(dir)) {
 839                         ext4_warning_inode(dir,
 840                                 "dx entry: limit %u != node limit %u",
 841                                 dx_get_limit(entries), dx_node_limit(dir));
 842                         goto fail;
 843                 }
 844         }
 845 fail:
 846         while (frame >= frame_in) {
 847                 brelse(frame->bh);
 848                 frame--;
 849         }
 850
 851         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 852                 ext4_warning_inode(dir,
 853                         "Corrupt directory, running e2fsck is recommended");
 854         return ret_err;
 855 }
 856
 857 static void dx_release(struct dx_frame *frames)
 858 {
 859         if (frames[0].bh == NULL)
 860                 return;
 861
 862         if (((struct dx_root *)frames[0].bh->b_data)->info.indirect_levels)
 863                 brelse(frames[1].bh);
 864         brelse(frames[0].bh);
 865 }
 866
 867 /*
 868  * This function increments the frame pointer to search the next leaf
 869  * block, and reads in the necessary intervening nodes if the search
 870  * should be necessary.  Whether or not the search is necessary is
 871  * controlled by the hash parameter.  If the hash value is even, then
 872  * the search is only continued if the next block starts with that
 873  * hash value.  This is used if we are searching for a specific file.
 874  *
 875  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 876  *
 877  * This function returns 1 if the caller should continue to search,
 878  * or 0 if it should not.  If there is an error reading one of the
 879  * index blocks, it will a negative error code.
 880  *
 881  * If start_hash is non-null, it will be filled in with the starting
 882  * hash of the next page.
 883  */
 884 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 885                                  struct dx_frame *frame,
 886                                  struct dx_frame *frames,
 887                                  __u32 *start_hash)
 888 {
 889         struct dx_frame *p;
 890         struct buffer_head *bh;
 891         int num_frames = 0;
 892         __u32 bhash;
 893
 894         p = frame;
 895         /*
 896          * Find the next leaf page by incrementing the frame pointer.
 897          * If we run out of entries in the interior node, loop around and
 898          * increment pointer in the parent node.  When we break out of
 899          * this loop, num_frames indicates the number of interior
 900          * nodes need to be read.
 901          */
 902         while (1) {
 903                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 904                         break;
 905                 if (p == frames)
 906                         return 0;
 907                 num_frames++;
 908                 p--;
 909         }
 910
 911         /*
 912          * If the hash is 1, then continue only if the next page has a
 913          * continuation hash of any value.  This is used for readdir
 914          * handling.  Otherwise, check to see if the hash matches the
 915          * desired contiuation hash.  If it doesn't, return since
 916          * there's no point to read in the successive index pages.
 917          */
 918         bhash = dx_get_hash(p->at);
 919         if (start_hash)
 920                 *start_hash = bhash;
 921         if ((hash & 1) == 0) {
 922                 if ((bhash & ~1) != hash)
 923                         return 0;
 924         }
 925         /*
 926          * If the hash is HASH_NB_ALWAYS, we always go to the next
 927          * block so no check is necessary
 928          */
 929         while (num_frames--) {
 930                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 931                 if (IS_ERR(bh))
 932                         return PTR_ERR(bh);
 933                 p++;
 934                 brelse(p->bh);
 935                 p->bh = bh;
 936                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 937         }
 938         return 1;
 939 }
 940
 941
 942 /*
 943  * This function fills a red-black tree with information from a
 944  * directory block.  It returns the number directory entries loaded
 945  * into the tree.  If there is an error it is returned in err.
 946  */
 947 static int htree_dirblock_to_tree(struct file *dir_file,
 948                                   struct inode *dir, ext4_lblk_t block,
 949                                   struct dx_hash_info *hinfo,
 950                                   __u32 start_hash, __u32 start_minor_hash)
 951 {
 952         struct buffer_head *bh;
 953         struct ext4_dir_entry_2 *de, *top;
 954         int err = 0, count = 0;
 955         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
 956
 957         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 958                                                         (unsigned long)block));
 959         bh = ext4_read_dirblock(dir, block, DIRENT);
 960         if (IS_ERR(bh))
 961                 return PTR_ERR(bh);
 962
 963         de = (struct ext4_dir_entry_2 *) bh->b_data;
 964         top = (struct ext4_dir_entry_2 *) ((char *) de +
 965                                            dir->i_sb->s_blocksize -
 966                                            EXT4_DIR_REC_LEN(0));
 967 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 968         /* Check if the directory is encrypted */
 969         if (ext4_encrypted_inode(dir)) {
 970                 err = ext4_get_encryption_info(dir);
 971                 if (err < 0) {
 972                         brelse(bh);
 973                         return err;
 974                 }
 975                 err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
 976                                                      &fname_crypto_str);
 977                 if (err < 0) {
 978                         brelse(bh);
 979                         return err;
 980                 }
 981         }
 982 #endif
 983         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 984                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 985                                 bh->b_data, bh->b_size,
 986                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 987                                          + ((char *)de - bh->b_data))) {
 988                         /* silently ignore the rest of the block */
 989                         break;
 990                 }
 991                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 992                 if ((hinfo->hash < start_hash) ||
 993                     ((hinfo->hash == start_hash) &&
 994                      (hinfo->minor_hash < start_minor_hash)))
 995                         continue;
 996                 if (de->inode == 0)
 997                         continue;
 998                 if (!ext4_encrypted_inode(dir)) {
 999                         tmp_str.name = de->name;
1000                         tmp_str.len = de->name_len;
1001                         err = ext4_htree_store_dirent(dir_file,
1002                                    hinfo->hash, hinfo->minor_hash, de,
1003                                    &tmp_str);
1004                 } else {
1005                         int save_len = fname_crypto_str.len;
1006
1007                         /* Directory is encrypted */
1008                         err = ext4_fname_disk_to_usr(dir, hinfo, de,
1009                                                      &fname_crypto_str);
1010                         if (err < 0) {
1011                                 count = err;
1012                                 goto errout;
1013                         }
1014                         err = ext4_htree_store_dirent(dir_file,
1015                                    hinfo->hash, hinfo->minor_hash, de,
1016                                         &fname_crypto_str);
1017                         fname_crypto_str.len = save_len;
1018                 }
1019                 if (err != 0) {
1020                         count = err;
1021                         goto errout;
1022                 }
1023                 count++;
1024         }
1025 errout:
1026         brelse(bh);
1027 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1028         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1029 #endif
1030         return count;
1031 }
1032
1033
1034 /*
1035  * This function fills a red-black tree with information from a
1036  * directory.  We start scanning the directory in hash order, starting
1037  * at start_hash and start_minor_hash.
1038  *
1039  * This function returns the number of entries inserted into the tree,
1040  * or a negative error code.
1041  */
1042 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1043                          __u32 start_minor_hash, __u32 *next_hash)
1044 {
1045         struct dx_hash_info hinfo;
1046         struct ext4_dir_entry_2 *de;
1047         struct dx_frame frames[2], *frame;
1048         struct inode *dir;
1049         ext4_lblk_t block;
1050         int count = 0;
1051         int ret, err;
1052         __u32 hashval;
1053         struct ext4_str tmp_str;
1054
1055         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1056                        start_hash, start_minor_hash));
1057         dir = file_inode(dir_file);
1058         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1059                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1060                 if (hinfo.hash_version <= DX_HASH_TEA)
1061                         hinfo.hash_version +=
1062                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1063                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1064                 if (ext4_has_inline_data(dir)) {
1065                         int has_inline_data = 1;
1066                         count = htree_inlinedir_to_tree(dir_file, dir, 0,
1067                                                         &hinfo, start_hash,
1068                                                         start_minor_hash,
1069                                                         &has_inline_data);
1070                         if (has_inline_data) {
1071                                 *next_hash = ~0;
1072                                 return count;
1073                         }
1074                 }
1075                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1076                                                start_hash, start_minor_hash);
1077                 *next_hash = ~0;
1078                 return count;
1079         }
1080         hinfo.hash = start_hash;
1081         hinfo.minor_hash = 0;
1082         frame = dx_probe(NULL, dir, &hinfo, frames);
1083         if (IS_ERR(frame))
1084                 return PTR_ERR(frame);
1085
1086         /* Add '.' and '..' from the htree header */
1087         if (!start_hash && !start_minor_hash) {
1088                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1089                 tmp_str.name = de->name;
1090                 tmp_str.len = de->name_len;
1091                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1092                                               de, &tmp_str);
1093                 if (err != 0)
1094                         goto errout;
1095                 count++;
1096         }
1097         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1098                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1099                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1100                 tmp_str.name = de->name;
1101                 tmp_str.len = de->name_len;
1102                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1103                                               de, &tmp_str);
1104                 if (err != 0)
1105                         goto errout;
1106                 count++;
1107         }
1108
1109         while (1) {
1110                 block = dx_get_block(frame->at);
1111                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1112                                              start_hash, start_minor_hash);
1113                 if (ret < 0) {
1114                         err = ret;
1115                         goto errout;
1116                 }
1117                 count += ret;
1118                 hashval = ~0;
1119                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1120                                             frame, frames, &hashval);
1121                 *next_hash = hashval;
1122                 if (ret < 0) {
1123                         err = ret;
1124                         goto errout;
1125                 }
1126                 /*
1127                  * Stop if:  (a) there are no more entries, or
1128                  * (b) we have inserted at least one entry and the
1129                  * next hash value is not a continuation
1130                  */
1131                 if ((ret == 0) ||
1132                     (count && ((hashval & 1) == 0)))
1133                         break;
1134         }
1135         dx_release(frames);
1136         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1137                        "next hash: %x\n", count, *next_hash));
1138         return count;
1139 errout:
1140         dx_release(frames);
1141         return (err);
1142 }
1143
1144 static inline int search_dirblock(struct buffer_head *bh,
1145                                   struct inode *dir,
1146                                   struct ext4_filename *fname,
1147                                   const struct qstr *d_name,
1148                                   unsigned int offset,
1149                                   struct ext4_dir_entry_2 **res_dir)
1150 {
1151         return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1152                                fname, d_name, offset, res_dir);
1153 }
1154
1155 /*
1156  * Directory block splitting, compacting
1157  */
1158
1159 /*
1160  * Create map of hash values, offsets, and sizes, stored at end of block.
1161  * Returns number of entries mapped.
1162  */
1163 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1164                        unsigned blocksize, struct dx_hash_info *hinfo,
1165                        struct dx_map_entry *map_tail)
1166 {
1167         int count = 0;
1168         char *base = (char *) de;
1169         struct dx_hash_info h = *hinfo;
1170
1171         while ((char *) de < base + blocksize) {
1172                 if (de->name_len && de->inode) {
1173                         ext4fs_dirhash(de->name, de->name_len, &h);
1174                         map_tail--;
1175                         map_tail->hash = h.hash;
1176                         map_tail->offs = ((char *) de - base)>>2;
1177                         map_tail->size = le16_to_cpu(de->rec_len);
1178                         count++;
1179                         cond_resched();
1180                 }
1181                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1182                 de = ext4_next_entry(de, blocksize);
1183         }
1184         return count;
1185 }
1186
1187 /* Sort map by hash value */
1188 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1189 {
1190         struct dx_map_entry *p, *q, *top = map + count - 1;
1191         int more;
1192         /* Combsort until bubble sort doesn't suck */
1193         while (count > 2) {
1194                 count = count*10/13;
1195                 if (count - 9 < 2) /* 9, 10 -> 11 */
1196                         count = 11;
1197                 for (p = top, q = p - count; q >= map; p--, q--)
1198                         if (p->hash < q->hash)
1199                                 swap(*p, *q);
1200         }
1201         /* Garden variety bubble sort */
1202         do {
1203                 more = 0;
1204                 q = top;
1205                 while (q-- > map) {
1206                         if (q[1].hash >= q[0].hash)
1207                                 continue;
1208                         swap(*(q+1), *q);
1209                         more = 1;
1210                 }
1211         } while(more);
1212 }
1213
1214 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1215 {
1216         struct dx_entry *entries = frame->entries;
1217         struct dx_entry *old = frame->at, *new = old + 1;
1218         int count = dx_get_count(entries);
1219
1220         assert(count < dx_get_limit(entries));
1221         assert(old < entries + count);
1222         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1223         dx_set_hash(new, hash);
1224         dx_set_block(new, block);
1225         dx_set_count(entries, count + 1);
1226 }
1227
1228 /*
1229  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1230  *
1231  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1232  * `de != NULL' is guaranteed by caller.
1233  */
1234 static inline int ext4_match(struct ext4_filename *fname,
1235                              struct ext4_dir_entry_2 *de)
1236 {
1237         const void *name = fname_name(fname);
1238         u32 len = fname_len(fname);
1239
1240         if (!de->inode)
1241                 return 0;
1242
1243 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1244         if (unlikely(!name)) {
1245                 if (fname->usr_fname->name[0] == '_') {
1246                         int ret;
1247                         if (de->name_len < 16)
1248                                 return 0;
1249                         ret = memcmp(de->name + de->name_len - 16,
1250                                      fname->crypto_buf.name + 8, 16);
1251                         return (ret == 0) ? 1 : 0;
1252                 }
1253                 name = fname->crypto_buf.name;
1254                 len = fname->crypto_buf.len;
1255         }
1256 #endif
1257         if (de->name_len != len)
1258                 return 0;
1259         return (memcmp(de->name, name, len) == 0) ? 1 : 0;
1260 }
1261
1262 /*
1263  * Returns 0 if not found, -1 on failure, and 1 on success
1264  */
1265 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1266                     struct inode *dir, struct ext4_filename *fname,
1267                     const struct qstr *d_name,
1268                     unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1269 {
1270         struct ext4_dir_entry_2 * de;
1271         char * dlimit;
1272         int de_len;
1273         int res;
1274
1275         de = (struct ext4_dir_entry_2 *)search_buf;
1276         dlimit = search_buf + buf_size;
1277         while ((char *) de < dlimit) {
1278                 /* this code is executed quadratically often */
1279                 /* do minimal checking `by hand' */
1280                 if ((char *) de + de->name_len <= dlimit) {
1281                         res = ext4_match(fname, de);
1282                         if (res < 0) {
1283                                 res = -1;
1284                                 goto return_result;
1285                         }
1286                         if (res > 0) {
1287                                 /* found a match - just to be sure, do
1288                                  * a full check */
1289                                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1290                                                 bh->b_data,
1291                                                  bh->b_size, offset)) {
1292                                         res = -1;
1293                                         goto return_result;
1294                                 }
1295                                 *res_dir = de;
1296                                 res = 1;
1297                                 goto return_result;
1298                         }
1299
1300                 }
1301                 /* prevent looping on a bad block */
1302                 de_len = ext4_rec_len_from_disk(de->rec_len,
1303                                                 dir->i_sb->s_blocksize);
1304                 if (de_len <= 0) {
1305                         res = -1;
1306                         goto return_result;
1307                 }
1308                 offset += de_len;
1309                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1310         }
1311
1312         res = 0;
1313 return_result:
1314         return res;
1315 }
1316
1317 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1318                                struct ext4_dir_entry *de)
1319 {
1320         struct super_block *sb = dir->i_sb;
1321
1322         if (!is_dx(dir))
1323                 return 0;
1324         if (block == 0)
1325                 return 1;
1326         if (de->inode == 0 &&
1327             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1328                         sb->s_blocksize)
1329                 return 1;
1330         return 0;
1331 }
1332
1333 /*
1334  *      ext4_find_entry()
1335  *
1336  * finds an entry in the specified directory with the wanted name. It
1337  * returns the cache buffer in which the entry was found, and the entry
1338  * itself (as a parameter - res_dir). It does NOT read the inode of the
1339  * entry - you'll have to do that yourself if you want to.
1340  *
1341  * The returned buffer_head has ->b_count elevated.  The caller is expected
1342  * to brelse() it when appropriate.
1343  */
1344 static struct buffer_head * ext4_find_entry (struct inode *dir,
1345                                         const struct qstr *d_name,
1346                                         struct ext4_dir_entry_2 **res_dir,
1347                                         int *inlined)
1348 {
1349         struct super_block *sb;
1350         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1351         struct buffer_head *bh, *ret = NULL;
1352         ext4_lblk_t start, block, b;
1353         const u8 *name = d_name->name;
1354         int ra_max = 0;         /* Number of bh's in the readahead
1355                                    buffer, bh_use[] */
1356         int ra_ptr = 0;         /* Current index into readahead
1357                                    buffer */
1358         int num = 0;
1359         ext4_lblk_t  nblocks;
1360         int i, namelen, retval;
1361         struct ext4_filename fname;
1362
1363         *res_dir = NULL;
1364         sb = dir->i_sb;
1365         namelen = d_name->len;
1366         if (namelen > EXT4_NAME_LEN)
1367                 return NULL;
1368
1369         retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1370         if (retval)
1371                 return ERR_PTR(retval);
1372
1373         if (ext4_has_inline_data(dir)) {
1374                 int has_inline_data = 1;
1375                 ret = ext4_find_inline_entry(dir, &fname, d_name, res_dir,
1376                                              &has_inline_data);
1377                 if (has_inline_data) {
1378                         if (inlined)
1379                                 *inlined = 1;
1380                         goto cleanup_and_exit;
1381                 }
1382         }
1383
1384         if ((namelen <= 2) && (name[0] == '.') &&
1385             (name[1] == '.' || name[1] == '\0')) {
1386                 /*
1387                  * "." or ".." will only be in the first block
1388                  * NFS may look up ".."; "." should be handled by the VFS
1389                  */
1390                 block = start = 0;
1391                 nblocks = 1;
1392                 goto restart;
1393         }
1394         if (is_dx(dir)) {
1395                 ret = ext4_dx_find_entry(dir, &fname, res_dir);
1396                 /*
1397                  * On success, or if the error was file not found,
1398                  * return.  Otherwise, fall back to doing a search the
1399                  * old fashioned way.
1400                  */
1401                 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1402                         goto cleanup_and_exit;
1403                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1404                                "falling back\n"));
1405         }
1406         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1407         start = EXT4_I(dir)->i_dir_start_lookup;
1408         if (start >= nblocks)
1409                 start = 0;
1410         block = start;
1411 restart:
1412         do {
1413                 /*
1414                  * We deal with the read-ahead logic here.
1415                  */
1416                 if (ra_ptr >= ra_max) {
1417                         /* Refill the readahead buffer */
1418                         ra_ptr = 0;
1419                         b = block;
1420                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1421                                 /*
1422                                  * Terminate if we reach the end of the
1423                                  * directory and must wrap, or if our
1424                                  * search has finished at this block.
1425                                  */
1426                                 if (b >= nblocks || (num && block == start)) {
1427                                         bh_use[ra_max] = NULL;
1428                                         break;
1429                                 }
1430                                 num++;
1431                                 bh = ext4_getblk(NULL, dir, b++, 0);
1432                                 if (IS_ERR(bh)) {
1433                                         if (ra_max == 0) {
1434                                                 ret = bh;
1435                                                 goto cleanup_and_exit;
1436                                         }
1437                                         break;
1438                                 }
1439                                 bh_use[ra_max] = bh;
1440                                 if (bh)
1441                                         ll_rw_block(READ | REQ_META | REQ_PRIO,
1442                                                     1, &bh);
1443                         }
1444                 }
1445                 if ((bh = bh_use[ra_ptr++]) == NULL)
1446                         goto next;
1447                 wait_on_buffer(bh);
1448                 if (!buffer_uptodate(bh)) {
1449                         /* read error, skip block & hope for the best */
1450                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1451                                          (unsigned long) block);
1452                         brelse(bh);
1453                         goto next;
1454                 }
1455                 if (!buffer_verified(bh) &&
1456                     !is_dx_internal_node(dir, block,
1457                                          (struct ext4_dir_entry *)bh->b_data) &&
1458                     !ext4_dirent_csum_verify(dir,
1459                                 (struct ext4_dir_entry *)bh->b_data)) {
1460                         EXT4_ERROR_INODE(dir, "checksumming directory "
1461                                          "block %lu", (unsigned long)block);
1462                         brelse(bh);
1463                         goto next;
1464                 }
1465                 set_buffer_verified(bh);
1466                 i = search_dirblock(bh, dir, &fname, d_name,
1467                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1468                 if (i == 1) {
1469                         EXT4_I(dir)->i_dir_start_lookup = block;
1470                         ret = bh;
1471                         goto cleanup_and_exit;
1472                 } else {
1473                         brelse(bh);
1474                         if (i < 0)
1475                                 goto cleanup_and_exit;
1476                 }
1477         next:
1478                 if (++block >= nblocks)
1479                         block = 0;
1480         } while (block != start);
1481
1482         /*
1483          * If the directory has grown while we were searching, then
1484          * search the last part of the directory before giving up.
1485          */
1486         block = nblocks;
1487         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1488         if (block < nblocks) {
1489                 start = 0;
1490                 goto restart;
1491         }
1492
1493 cleanup_and_exit:
1494         /* Clean up the read-ahead blocks */
1495         for (; ra_ptr < ra_max; ra_ptr++)
1496                 brelse(bh_use[ra_ptr]);
1497         ext4_fname_free_filename(&fname);
1498         return ret;
1499 }
1500
1501 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1502                         struct ext4_filename *fname,
1503                         struct ext4_dir_entry_2 **res_dir)
1504 {
1505         struct super_block * sb = dir->i_sb;
1506         struct dx_frame frames[2], *frame;
1507         const struct qstr *d_name = fname->usr_fname;
1508         struct buffer_head *bh;
1509         ext4_lblk_t block;
1510         int retval;
1511
1512 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1513         *res_dir = NULL;
1514 #endif
1515         frame = dx_probe(fname, dir, NULL, frames);
1516         if (IS_ERR(frame))
1517                 return (struct buffer_head *) frame;
1518         do {
1519                 block = dx_get_block(frame->at);
1520                 bh = ext4_read_dirblock(dir, block, DIRENT);
1521                 if (IS_ERR(bh))
1522                         goto errout;
1523
1524                 retval = search_dirblock(bh, dir, fname, d_name,
1525                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1526                                          res_dir);
1527                 if (retval == 1)
1528                         goto success;
1529                 brelse(bh);
1530                 if (retval == -1) {
1531                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1532                         goto errout;
1533                 }
1534
1535                 /* Check to see if we should continue to search */
1536                 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1537                                                frames, NULL);
1538                 if (retval < 0) {
1539                         ext4_warning_inode(dir,
1540                                 "error %d reading directory index block",
1541                                 retval);
1542                         bh = ERR_PTR(retval);
1543                         goto errout;
1544                 }
1545         } while (retval == 1);
1546
1547         bh = NULL;
1548 errout:
1549         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1550 success:
1551         dx_release(frames);
1552         return bh;
1553 }
1554
1555 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1556 {
1557         struct inode *inode;
1558         struct ext4_dir_entry_2 *de;
1559         struct buffer_head *bh;
1560
1561         if (dentry->d_name.len > EXT4_NAME_LEN)
1562                 return ERR_PTR(-ENAMETOOLONG);
1563
1564         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1565         if (IS_ERR(bh))
1566                 return (struct dentry *) bh;
1567         inode = NULL;
1568         if (bh) {
1569                 __u32 ino = le32_to_cpu(de->inode);
1570                 brelse(bh);
1571                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1572                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1573                         return ERR_PTR(-EFSCORRUPTED);
1574                 }
1575                 if (unlikely(ino == dir->i_ino)) {
1576                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1577                                          dentry);
1578                         return ERR_PTR(-EFSCORRUPTED);
1579                 }
1580                 inode = ext4_iget_normal(dir->i_sb, ino);
1581                 if (inode == ERR_PTR(-ESTALE)) {
1582                         EXT4_ERROR_INODE(dir,
1583                                          "deleted inode referenced: %u",
1584                                          ino);
1585                         return ERR_PTR(-EFSCORRUPTED);
1586                 }
1587                 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1588                     (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1589                      S_ISLNK(inode->i_mode)) &&
1590                     !ext4_is_child_context_consistent_with_parent(dir,
1591                                                                   inode)) {
1592                         iput(inode);
1593                         ext4_warning(inode->i_sb,
1594                                      "Inconsistent encryption contexts: %lu/%lu\n",
1595                                      (unsigned long) dir->i_ino,
1596                                      (unsigned long) inode->i_ino);
1597                         return ERR_PTR(-EPERM);
1598                 }
1599         }
1600         return d_splice_alias(inode, dentry);
1601 }
1602
1603
1604 struct dentry *ext4_get_parent(struct dentry *child)
1605 {
1606         __u32 ino;
1607         static const struct qstr dotdot = QSTR_INIT("..", 2);
1608         struct ext4_dir_entry_2 * de;
1609         struct buffer_head *bh;
1610
1611         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1612         if (IS_ERR(bh))
1613                 return (struct dentry *) bh;
1614         if (!bh)
1615                 return ERR_PTR(-ENOENT);
1616         ino = le32_to_cpu(de->inode);
1617         brelse(bh);
1618
1619         if (!ext4_valid_inum(d_inode(child)->i_sb, ino)) {
1620                 EXT4_ERROR_INODE(d_inode(child),
1621                                  "bad parent inode number: %u", ino);
1622                 return ERR_PTR(-EFSCORRUPTED);
1623         }
1624
1625         return d_obtain_alias(ext4_iget_normal(d_inode(child)->i_sb, ino));
1626 }
1627
1628 /*
1629  * Move count entries from end of map between two memory locations.
1630  * Returns pointer to last entry moved.
1631  */
1632 static struct ext4_dir_entry_2 *
1633 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1634                 unsigned blocksize)
1635 {
1636         unsigned rec_len = 0;
1637
1638         while (count--) {
1639                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1640                                                 (from + (map->offs<<2));
1641                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1642                 memcpy (to, de, rec_len);
1643                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1644                                 ext4_rec_len_to_disk(rec_len, blocksize);
1645                 de->inode = 0;
1646                 map++;
1647                 to += rec_len;
1648         }
1649         return (struct ext4_dir_entry_2 *) (to - rec_len);
1650 }
1651
1652 /*
1653  * Compact each dir entry in the range to the minimal rec_len.
1654  * Returns pointer to last entry in range.
1655  */
1656 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1657 {
1658         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1659         unsigned rec_len = 0;
1660
1661         prev = to = de;
1662         while ((char*)de < base + blocksize) {
1663                 next = ext4_next_entry(de, blocksize);
1664                 if (de->inode && de->name_len) {
1665                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1666                         if (de > to)
1667                                 memmove(to, de, rec_len);
1668                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1669                         prev = to;
1670                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1671                 }
1672                 de = next;
1673         }
1674         return prev;
1675 }
1676
1677 /*
1678  * Split a full leaf block to make room for a new dir entry.
1679  * Allocate a new block, and move entries so that they are approx. equally full.
1680  * Returns pointer to de in block into which the new entry will be inserted.
1681  */
1682 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1683                         struct buffer_head **bh,struct dx_frame *frame,
1684                         struct dx_hash_info *hinfo)
1685 {
1686         unsigned blocksize = dir->i_sb->s_blocksize;
1687         unsigned count, continued;
1688         struct buffer_head *bh2;
1689         ext4_lblk_t newblock;
1690         u32 hash2;
1691         struct dx_map_entry *map;
1692         char *data1 = (*bh)->b_data, *data2;
1693         unsigned split, move, size;
1694         struct ext4_dir_entry_2 *de = NULL, *de2;
1695         struct ext4_dir_entry_tail *t;
1696         int     csum_size = 0;
1697         int     err = 0, i;
1698
1699         if (ext4_has_metadata_csum(dir->i_sb))
1700                 csum_size = sizeof(struct ext4_dir_entry_tail);
1701
1702         bh2 = ext4_append(handle, dir, &newblock);
1703         if (IS_ERR(bh2)) {
1704                 brelse(*bh);
1705                 *bh = NULL;
1706                 return (struct ext4_dir_entry_2 *) bh2;
1707         }
1708
1709         BUFFER_TRACE(*bh, "get_write_access");
1710         err = ext4_journal_get_write_access(handle, *bh);
1711         if (err)
1712                 goto journal_error;
1713
1714         BUFFER_TRACE(frame->bh, "get_write_access");
1715         err = ext4_journal_get_write_access(handle, frame->bh);
1716         if (err)
1717                 goto journal_error;
1718
1719         data2 = bh2->b_data;
1720
1721         /* create map in the end of data2 block */
1722         map = (struct dx_map_entry *) (data2 + blocksize);
1723         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1724                              blocksize, hinfo, map);
1725         map -= count;
1726         dx_sort_map(map, count);
1727         /* Split the existing block in the middle, size-wise */
1728         size = 0;
1729         move = 0;
1730         for (i = count-1; i >= 0; i--) {
1731                 /* is more than half of this entry in 2nd half of the block? */
1732                 if (size + map[i].size/2 > blocksize/2)
1733                         break;
1734                 size += map[i].size;
1735                 move++;
1736         }
1737         /* map index at which we will split */
1738         split = count - move;
1739         hash2 = map[split].hash;
1740         continued = hash2 == map[split - 1].hash;
1741         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1742                         (unsigned long)dx_get_block(frame->at),
1743                                         hash2, split, count-split));
1744
1745         /* Fancy dance to stay within two buffers */
1746         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1747                               blocksize);
1748         de = dx_pack_dirents(data1, blocksize);
1749         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1750                                            (char *) de,
1751                                            blocksize);
1752         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1753                                             (char *) de2,
1754                                             blocksize);
1755         if (csum_size) {
1756                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1757                 initialize_dirent_tail(t, blocksize);
1758
1759                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1760                 initialize_dirent_tail(t, blocksize);
1761         }
1762
1763         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1764                         blocksize, 1));
1765         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1766                         blocksize, 1));
1767
1768         /* Which block gets the new entry? */
1769         if (hinfo->hash >= hash2) {
1770                 swap(*bh, bh2);
1771                 de = de2;
1772         }
1773         dx_insert_block(frame, hash2 + continued, newblock);
1774         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1775         if (err)
1776                 goto journal_error;
1777         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1778         if (err)
1779                 goto journal_error;
1780         brelse(bh2);
1781         dxtrace(dx_show_index("frame", frame->entries));
1782         return de;
1783
1784 journal_error:
1785         brelse(*bh);
1786         brelse(bh2);
1787         *bh = NULL;
1788         ext4_std_error(dir->i_sb, err);
1789         return ERR_PTR(err);
1790 }
1791
1792 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1793                       struct buffer_head *bh,
1794                       void *buf, int buf_size,
1795                       struct ext4_filename *fname,
1796                       struct ext4_dir_entry_2 **dest_de)
1797 {
1798         struct ext4_dir_entry_2 *de;
1799         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1800         int nlen, rlen;
1801         unsigned int offset = 0;
1802         char *top;
1803         int res;
1804
1805         de = (struct ext4_dir_entry_2 *)buf;
1806         top = buf + buf_size - reclen;
1807         while ((char *) de <= top) {
1808                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1809                                          buf, buf_size, offset)) {
1810                         res = -EFSCORRUPTED;
1811                         goto return_result;
1812                 }
1813                 /* Provide crypto context and crypto buffer to ext4 match */
1814                 res = ext4_match(fname, de);
1815                 if (res < 0)
1816                         goto return_result;
1817                 if (res > 0) {
1818                         res = -EEXIST;
1819                         goto return_result;
1820                 }
1821                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1822                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1823                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1824                         break;
1825                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1826                 offset += rlen;
1827         }
1828
1829         if ((char *) de > top)
1830                 res = -ENOSPC;
1831         else {
1832                 *dest_de = de;
1833                 res = 0;
1834         }
1835 return_result:
1836         return res;
1837 }
1838
1839 int ext4_insert_dentry(struct inode *dir,
1840                        struct inode *inode,
1841                        struct ext4_dir_entry_2 *de,
1842                        int buf_size,
1843                        struct ext4_filename *fname)
1844 {
1845
1846         int nlen, rlen;
1847
1848         nlen = EXT4_DIR_REC_LEN(de->name_len);
1849         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1850         if (de->inode) {
1851                 struct ext4_dir_entry_2 *de1 =
1852                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1853                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1854                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1855                 de = de1;
1856         }
1857         de->file_type = EXT4_FT_UNKNOWN;
1858         de->inode = cpu_to_le32(inode->i_ino);
1859         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1860         de->name_len = fname_len(fname);
1861         memcpy(de->name, fname_name(fname), fname_len(fname));
1862         return 0;
1863 }
1864
1865 /*
1866  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1867  * it points to a directory entry which is guaranteed to be large
1868  * enough for new directory entry.  If de is NULL, then
1869  * add_dirent_to_buf will attempt search the directory block for
1870  * space.  It will return -ENOSPC if no space is available, and -EIO
1871  * and -EEXIST if directory entry already exists.
1872  */
1873 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1874                              struct inode *dir,
1875                              struct inode *inode, struct ext4_dir_entry_2 *de,
1876                              struct buffer_head *bh)
1877 {
1878         unsigned int    blocksize = dir->i_sb->s_blocksize;
1879         int             csum_size = 0;
1880         int             err;
1881
1882         if (ext4_has_metadata_csum(inode->i_sb))
1883                 csum_size = sizeof(struct ext4_dir_entry_tail);
1884
1885         if (!de) {
1886                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1887                                         blocksize - csum_size, fname, &de);
1888                 if (err)
1889                         return err;
1890         }
1891         BUFFER_TRACE(bh, "get_write_access");
1892         err = ext4_journal_get_write_access(handle, bh);
1893         if (err) {
1894                 ext4_std_error(dir->i_sb, err);
1895                 return err;
1896         }
1897
1898         /* By now the buffer is marked for journaling. Due to crypto operations,
1899          * the following function call may fail */
1900         err = ext4_insert_dentry(dir, inode, de, blocksize, fname);
1901         if (err < 0)
1902                 return err;
1903
1904         /*
1905          * XXX shouldn't update any times until successful
1906          * completion of syscall, but too many callers depend
1907          * on this.
1908          *
1909          * XXX similarly, too many callers depend on
1910          * ext4_new_inode() setting the times, but error
1911          * recovery deletes the inode, so the worst that can
1912          * happen is that the times are slightly out of date
1913          * and/or different from the directory change time.
1914          */
1915         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1916         ext4_update_dx_flag(dir);
1917         dir->i_version++;
1918         ext4_mark_inode_dirty(handle, dir);
1919         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1920         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1921         if (err)
1922                 ext4_std_error(dir->i_sb, err);
1923         return 0;
1924 }
1925
1926 /*
1927  * This converts a one block unindexed directory to a 3 block indexed
1928  * directory, and adds the dentry to the indexed directory.
1929  */
1930 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1931                             struct inode *dir,
1932                             struct inode *inode, struct buffer_head *bh)
1933 {
1934         struct buffer_head *bh2;
1935         struct dx_root  *root;
1936         struct dx_frame frames[2], *frame;
1937         struct dx_entry *entries;
1938         struct ext4_dir_entry_2 *de, *de2;
1939         struct ext4_dir_entry_tail *t;
1940         char            *data1, *top;
1941         unsigned        len;
1942         int             retval;
1943         unsigned        blocksize;
1944         ext4_lblk_t  block;
1945         struct fake_dirent *fde;
1946         int csum_size = 0;
1947
1948         if (ext4_has_metadata_csum(inode->i_sb))
1949                 csum_size = sizeof(struct ext4_dir_entry_tail);
1950
1951         blocksize =  dir->i_sb->s_blocksize;
1952         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1953         BUFFER_TRACE(bh, "get_write_access");
1954         retval = ext4_journal_get_write_access(handle, bh);
1955         if (retval) {
1956                 ext4_std_error(dir->i_sb, retval);
1957                 brelse(bh);
1958                 return retval;
1959         }
1960         root = (struct dx_root *) bh->b_data;
1961
1962         /* The 0th block becomes the root, move the dirents out */
1963         fde = &root->dotdot;
1964         de = (struct ext4_dir_entry_2 *)((char *)fde +
1965                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1966         if ((char *) de >= (((char *) root) + blocksize)) {
1967                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1968                 brelse(bh);
1969                 return -EFSCORRUPTED;
1970         }
1971         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1972
1973         /* Allocate new block for the 0th block's dirents */
1974         bh2 = ext4_append(handle, dir, &block);
1975         if (IS_ERR(bh2)) {
1976                 brelse(bh);
1977                 return PTR_ERR(bh2);
1978         }
1979         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1980         data1 = bh2->b_data;
1981
1982         memcpy (data1, de, len);
1983         de = (struct ext4_dir_entry_2 *) data1;
1984         top = data1 + len;
1985         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1986                 de = de2;
1987         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1988                                            (char *) de,
1989                                            blocksize);
1990
1991         if (csum_size) {
1992                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1993                 initialize_dirent_tail(t, blocksize);
1994         }
1995
1996         /* Initialize the root; the dot dirents already exist */
1997         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1998         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1999                                            blocksize);
2000         memset (&root->info, 0, sizeof(root->info));
2001         root->info.info_length = sizeof(root->info);
2002         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2003         entries = root->entries;
2004         dx_set_block(entries, 1);
2005         dx_set_count(entries, 1);
2006         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2007
2008         /* Initialize as for dx_probe */
2009         fname->hinfo.hash_version = root->info.hash_version;
2010         if (fname->hinfo.hash_version <= DX_HASH_TEA)
2011                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2012         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2013         ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
2014
2015         memset(frames, 0, sizeof(frames));
2016         frame = frames;
2017         frame->entries = entries;
2018         frame->at = entries;
2019         frame->bh = bh;
2020         bh = bh2;
2021
2022         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2023         if (retval)
2024                 goto out_frames;
2025         retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
2026         if (retval)
2027                 goto out_frames;
2028
2029         de = do_split(handle,dir, &bh, frame, &fname->hinfo);
2030         if (IS_ERR(de)) {
2031                 retval = PTR_ERR(de);
2032                 goto out_frames;
2033         }
2034         dx_release(frames);
2035
2036         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2037         brelse(bh);
2038         return retval;
2039 out_frames:
2040         /*
2041          * Even if the block split failed, we have to properly write
2042          * out all the changes we did so far. Otherwise we can end up
2043          * with corrupted filesystem.
2044          */
2045         ext4_mark_inode_dirty(handle, dir);
2046         dx_release(frames);
2047         return retval;
2048 }
2049
2050 /*
2051  *      ext4_add_entry()
2052  *
2053  * adds a file entry to the specified directory, using the same
2054  * semantics as ext4_find_entry(). It returns NULL if it failed.
2055  *
2056  * NOTE!! The inode part of 'de' is left at 0 - which means you
2057  * may not sleep between calling this and putting something into
2058  * the entry, as someone else might have used it while you slept.
2059  */
2060 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2061                           struct inode *inode)
2062 {
2063         struct inode *dir = d_inode(dentry->d_parent);
2064         struct buffer_head *bh = NULL;
2065         struct ext4_dir_entry_2 *de;
2066         struct ext4_dir_entry_tail *t;
2067         struct super_block *sb;
2068         struct ext4_filename fname;
2069         int     retval;
2070         int     dx_fallback=0;
2071         unsigned blocksize;
2072         ext4_lblk_t block, blocks;
2073         int     csum_size = 0;
2074
2075         if (ext4_has_metadata_csum(inode->i_sb))
2076                 csum_size = sizeof(struct ext4_dir_entry_tail);
2077
2078         sb = dir->i_sb;
2079         blocksize = sb->s_blocksize;
2080         if (!dentry->d_name.len)
2081                 return -EINVAL;
2082
2083         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2084         if (retval)
2085                 return retval;
2086
2087         if (ext4_has_inline_data(dir)) {
2088                 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2089                 if (retval < 0)
2090                         goto out;
2091                 if (retval == 1) {
2092                         retval = 0;
2093                         goto out;
2094                 }
2095         }
2096
2097         if (is_dx(dir)) {
2098                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2099                 if (!retval || (retval != ERR_BAD_DX_DIR))
2100                         goto out;
2101                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2102                 dx_fallback++;
2103                 ext4_mark_inode_dirty(handle, dir);
2104         }
2105         blocks = dir->i_size >> sb->s_blocksize_bits;
2106         for (block = 0; block < blocks; block++) {
2107                 bh = ext4_read_dirblock(dir, block, DIRENT);
2108                 if (IS_ERR(bh)) {
2109                         retval = PTR_ERR(bh);
2110                         bh = NULL;
2111                         goto out;
2112                 }
2113                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2114                                            NULL, bh);
2115                 if (retval != -ENOSPC)
2116                         goto out;
2117
2118                 if (blocks == 1 && !dx_fallback &&
2119                     ext4_has_feature_dir_index(sb)) {
2120                         retval = make_indexed_dir(handle, &fname, dir,
2121                                                   inode, bh);
2122                         bh = NULL; /* make_indexed_dir releases bh */
2123                         goto out;
2124                 }
2125                 brelse(bh);
2126         }
2127         bh = ext4_append(handle, dir, &block);
2128         if (IS_ERR(bh)) {
2129                 retval = PTR_ERR(bh);
2130                 bh = NULL;
2131                 goto out;
2132         }
2133         de = (struct ext4_dir_entry_2 *) bh->b_data;
2134         de->inode = 0;
2135         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2136
2137         if (csum_size) {
2138                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2139                 initialize_dirent_tail(t, blocksize);
2140         }
2141
2142         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2143 out:
2144         ext4_fname_free_filename(&fname);
2145         brelse(bh);
2146         if (retval == 0)
2147                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2148         return retval;
2149 }
2150
2151 /*
2152  * Returns 0 for success, or a negative error value
2153  */
2154 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2155                              struct inode *dir, struct inode *inode)
2156 {
2157         struct dx_frame frames[2], *frame;
2158         struct dx_entry *entries, *at;
2159         struct buffer_head *bh;
2160         struct super_block *sb = dir->i_sb;
2161         struct ext4_dir_entry_2 *de;
2162         int err;
2163
2164         frame = dx_probe(fname, dir, NULL, frames);
2165         if (IS_ERR(frame))
2166                 return PTR_ERR(frame);
2167         entries = frame->entries;
2168         at = frame->at;
2169         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2170         if (IS_ERR(bh)) {
2171                 err = PTR_ERR(bh);
2172                 bh = NULL;
2173                 goto cleanup;
2174         }
2175
2176         BUFFER_TRACE(bh, "get_write_access");
2177         err = ext4_journal_get_write_access(handle, bh);
2178         if (err)
2179                 goto journal_error;
2180
2181         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2182         if (err != -ENOSPC)
2183                 goto cleanup;
2184
2185         /* Block full, should compress but for now just split */
2186         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2187                        dx_get_count(entries), dx_get_limit(entries)));
2188         /* Need to split index? */
2189         if (dx_get_count(entries) == dx_get_limit(entries)) {
2190                 ext4_lblk_t newblock;
2191                 unsigned icount = dx_get_count(entries);
2192                 int levels = frame - frames;
2193                 struct dx_entry *entries2;
2194                 struct dx_node *node2;
2195                 struct buffer_head *bh2;
2196
2197                 if (levels && (dx_get_count(frames->entries) ==
2198                                dx_get_limit(frames->entries))) {
2199                         ext4_warning_inode(dir, "Directory index full!");
2200                         err = -ENOSPC;
2201                         goto cleanup;
2202                 }
2203                 bh2 = ext4_append(handle, dir, &newblock);
2204                 if (IS_ERR(bh2)) {
2205                         err = PTR_ERR(bh2);
2206                         goto cleanup;
2207                 }
2208                 node2 = (struct dx_node *)(bh2->b_data);
2209                 entries2 = node2->entries;
2210                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2211                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2212                                                            sb->s_blocksize);
2213                 BUFFER_TRACE(frame->bh, "get_write_access");
2214                 err = ext4_journal_get_write_access(handle, frame->bh);
2215                 if (err)
2216                         goto journal_error;
2217                 if (levels) {
2218                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2219                         unsigned hash2 = dx_get_hash(entries + icount1);
2220                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2221                                        icount1, icount2));
2222
2223                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2224                         err = ext4_journal_get_write_access(handle,
2225                                                              frames[0].bh);
2226                         if (err)
2227                                 goto journal_error;
2228
2229                         memcpy((char *) entries2, (char *) (entries + icount1),
2230                                icount2 * sizeof(struct dx_entry));
2231                         dx_set_count(entries, icount1);
2232                         dx_set_count(entries2, icount2);
2233                         dx_set_limit(entries2, dx_node_limit(dir));
2234
2235                         /* Which index block gets the new entry? */
2236                         if (at - entries >= icount1) {
2237                                 frame->at = at = at - entries - icount1 + entries2;
2238                                 frame->entries = entries = entries2;
2239                                 swap(frame->bh, bh2);
2240                         }
2241                         dx_insert_block(frames + 0, hash2, newblock);
2242                         dxtrace(dx_show_index("node", frames[1].entries));
2243                         dxtrace(dx_show_index("node",
2244                                ((struct dx_node *) bh2->b_data)->entries));
2245                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2246                         if (err)
2247                                 goto journal_error;
2248                         brelse (bh2);
2249                 } else {
2250                         dxtrace(printk(KERN_DEBUG
2251                                        "Creating second level index...\n"));
2252                         memcpy((char *) entries2, (char *) entries,
2253                                icount * sizeof(struct dx_entry));
2254                         dx_set_limit(entries2, dx_node_limit(dir));
2255
2256                         /* Set up root */
2257                         dx_set_count(entries, 1);
2258                         dx_set_block(entries + 0, newblock);
2259                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2260
2261                         /* Add new access path frame */
2262                         frame = frames + 1;
2263                         frame->at = at = at - entries + entries2;
2264                         frame->entries = entries = entries2;
2265                         frame->bh = bh2;
2266                         err = ext4_journal_get_write_access(handle,
2267                                                              frame->bh);
2268                         if (err)
2269                                 goto journal_error;
2270                 }
2271                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2272                 if (err) {
2273                         ext4_std_error(inode->i_sb, err);
2274                         goto cleanup;
2275                 }
2276         }
2277         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2278         if (IS_ERR(de)) {
2279                 err = PTR_ERR(de);
2280                 goto cleanup;
2281         }
2282         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2283         goto cleanup;
2284
2285 journal_error:
2286         ext4_std_error(dir->i_sb, err);
2287 cleanup:
2288         brelse(bh);
2289         dx_release(frames);
2290         return err;
2291 }
2292
2293 /*
2294  * ext4_generic_delete_entry deletes a directory entry by merging it
2295  * with the previous entry
2296  */
2297 int ext4_generic_delete_entry(handle_t *handle,
2298                               struct inode *dir,
2299                               struct ext4_dir_entry_2 *de_del,
2300                               struct buffer_head *bh,
2301                               void *entry_buf,
2302                               int buf_size,
2303                               int csum_size)
2304 {
2305         struct ext4_dir_entry_2 *de, *pde;
2306         unsigned int blocksize = dir->i_sb->s_blocksize;
2307         int i;
2308
2309         i = 0;
2310         pde = NULL;
2311         de = (struct ext4_dir_entry_2 *)entry_buf;
2312         while (i < buf_size - csum_size) {
2313                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2314                                          bh->b_data, bh->b_size, i))
2315                         return -EFSCORRUPTED;
2316                 if (de == de_del)  {
2317                         if (pde)
2318                                 pde->rec_len = ext4_rec_len_to_disk(
2319                                         ext4_rec_len_from_disk(pde->rec_len,
2320                                                                blocksize) +
2321                                         ext4_rec_len_from_disk(de->rec_len,
2322                                                                blocksize),
2323                                         blocksize);
2324                         else
2325                                 de->inode = 0;
2326                         dir->i_version++;
2327                         return 0;
2328                 }
2329                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2330                 pde = de;
2331                 de = ext4_next_entry(de, blocksize);
2332         }
2333         return -ENOENT;
2334 }
2335
2336 static int ext4_delete_entry(handle_t *handle,
2337                              struct inode *dir,
2338                              struct ext4_dir_entry_2 *de_del,
2339                              struct buffer_head *bh)
2340 {
2341         int err, csum_size = 0;
2342
2343         if (ext4_has_inline_data(dir)) {
2344                 int has_inline_data = 1;
2345                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2346                                                &has_inline_data);
2347                 if (has_inline_data)
2348                         return err;
2349         }
2350
2351         if (ext4_has_metadata_csum(dir->i_sb))
2352                 csum_size = sizeof(struct ext4_dir_entry_tail);
2353
2354         BUFFER_TRACE(bh, "get_write_access");
2355         err = ext4_journal_get_write_access(handle, bh);
2356         if (unlikely(err))
2357                 goto out;
2358
2359         err = ext4_generic_delete_entry(handle, dir, de_del,
2360                                         bh, bh->b_data,
2361                                         dir->i_sb->s_blocksize, csum_size);
2362         if (err)
2363                 goto out;
2364
2365         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2366         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2367         if (unlikely(err))
2368                 goto out;
2369
2370         return 0;
2371 out:
2372         if (err != -ENOENT)
2373                 ext4_std_error(dir->i_sb, err);
2374         return err;
2375 }
2376
2377 /*
2378  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2379  * since this indicates that nlinks count was previously 1.
2380  */
2381 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2382 {
2383         inc_nlink(inode);
2384         if (is_dx(inode) && inode->i_nlink > 1) {
2385                 /* limit is 16-bit i_links_count */
2386                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2387                         set_nlink(inode, 1);
2388                         ext4_set_feature_dir_nlink(inode->i_sb);
2389                 }
2390         }
2391 }
2392
2393 /*
2394  * If a directory had nlink == 1, then we should let it be 1. This indicates
2395  * directory has >EXT4_LINK_MAX subdirs.
2396  */
2397 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2398 {
2399         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2400                 drop_nlink(inode);
2401 }
2402
2403
2404 static int ext4_add_nondir(handle_t *handle,
2405                 struct dentry *dentry, struct inode *inode)
2406 {
2407         int err = ext4_add_entry(handle, dentry, inode);
2408         if (!err) {
2409                 ext4_mark_inode_dirty(handle, inode);
2410                 unlock_new_inode(inode);
2411                 d_instantiate(dentry, inode);
2412                 return 0;
2413         }
2414         drop_nlink(inode);
2415         unlock_new_inode(inode);
2416         iput(inode);
2417         return err;
2418 }
2419
2420 /*
2421  * By the time this is called, we already have created
2422  * the directory cache entry for the new file, but it
2423  * is so far negative - it has no inode.
2424  *
2425  * If the create succeeds, we fill in the inode information
2426  * with d_instantiate().
2427  */
2428 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2429                        bool excl)
2430 {
2431         handle_t *handle;
2432         struct inode *inode;
2433         int err, credits, retries = 0;
2434
2435         err = dquot_initialize(dir);
2436         if (err)
2437                 return err;
2438
2439         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2440                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2441 retry:
2442         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2443                                             NULL, EXT4_HT_DIR, credits);
2444         handle = ext4_journal_current_handle();
2445         err = PTR_ERR(inode);
2446         if (!IS_ERR(inode)) {
2447                 inode->i_op = &ext4_file_inode_operations;
2448                 inode->i_fop = &ext4_file_operations;
2449                 ext4_set_aops(inode);
2450                 err = ext4_add_nondir(handle, dentry, inode);
2451                 if (!err && IS_DIRSYNC(dir))
2452                         ext4_handle_sync(handle);
2453         }
2454         if (handle)
2455                 ext4_journal_stop(handle);
2456         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2457                 goto retry;
2458         return err;
2459 }
2460
2461 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2462                       umode_t mode, dev_t rdev)
2463 {
2464         handle_t *handle;
2465         struct inode *inode;
2466         int err, credits, retries = 0;
2467
2468         err = dquot_initialize(dir);
2469         if (err)
2470                 return err;
2471
2472         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2473                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2474 retry:
2475         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2476                                             NULL, EXT4_HT_DIR, credits);
2477         handle = ext4_journal_current_handle();
2478         err = PTR_ERR(inode);
2479         if (!IS_ERR(inode)) {
2480                 init_special_inode(inode, inode->i_mode, rdev);
2481                 inode->i_op = &ext4_special_inode_operations;
2482                 err = ext4_add_nondir(handle, dentry, inode);
2483                 if (!err && IS_DIRSYNC(dir))
2484                         ext4_handle_sync(handle);
2485         }
2486         if (handle)
2487                 ext4_journal_stop(handle);
2488         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2489                 goto retry;
2490         return err;
2491 }
2492
2493 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2494 {
2495         handle_t *handle;
2496         struct inode *inode;
2497         int err, retries = 0;
2498
2499         err = dquot_initialize(dir);
2500         if (err)
2501                 return err;
2502
2503 retry:
2504         inode = ext4_new_inode_start_handle(dir, mode,
2505                                             NULL, 0, NULL,
2506                                             EXT4_HT_DIR,
2507                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2508                           4 + EXT4_XATTR_TRANS_BLOCKS);
2509         handle = ext4_journal_current_handle();
2510         err = PTR_ERR(inode);
2511         if (!IS_ERR(inode)) {
2512                 inode->i_op = &ext4_file_inode_operations;
2513                 inode->i_fop = &ext4_file_operations;
2514                 ext4_set_aops(inode);
2515                 d_tmpfile(dentry, inode);
2516                 err = ext4_orphan_add(handle, inode);
2517                 if (err)
2518                         goto err_unlock_inode;
2519                 mark_inode_dirty(inode);
2520                 unlock_new_inode(inode);
2521         }
2522         if (handle)
2523                 ext4_journal_stop(handle);
2524         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2525                 goto retry;
2526         return err;
2527 err_unlock_inode:
2528         ext4_journal_stop(handle);
2529         unlock_new_inode(inode);
2530         return err;
2531 }
2532
2533 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2534                           struct ext4_dir_entry_2 *de,
2535                           int blocksize, int csum_size,
2536                           unsigned int parent_ino, int dotdot_real_len)
2537 {
2538         de->inode = cpu_to_le32(inode->i_ino);
2539         de->name_len = 1;
2540         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2541                                            blocksize);
2542         strcpy(de->name, ".");
2543         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2544
2545         de = ext4_next_entry(de, blocksize);
2546         de->inode = cpu_to_le32(parent_ino);
2547         de->name_len = 2;
2548         if (!dotdot_real_len)
2549                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2550                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2551                                         blocksize);
2552         else
2553                 de->rec_len = ext4_rec_len_to_disk(
2554                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2555         strcpy(de->name, "..");
2556         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2557
2558         return ext4_next_entry(de, blocksize);
2559 }
2560
2561 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2562                              struct inode *inode)
2563 {
2564         struct buffer_head *dir_block = NULL;
2565         struct ext4_dir_entry_2 *de;
2566         struct ext4_dir_entry_tail *t;
2567         ext4_lblk_t block = 0;
2568         unsigned int blocksize = dir->i_sb->s_blocksize;
2569         int csum_size = 0;
2570         int err;
2571
2572         if (ext4_has_metadata_csum(dir->i_sb))
2573                 csum_size = sizeof(struct ext4_dir_entry_tail);
2574
2575         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2576                 err = ext4_try_create_inline_dir(handle, dir, inode);
2577                 if (err < 0 && err != -ENOSPC)
2578                         goto out;
2579                 if (!err)
2580                         goto out;
2581         }
2582
2583         inode->i_size = 0;
2584         dir_block = ext4_append(handle, inode, &block);
2585         if (IS_ERR(dir_block))
2586                 return PTR_ERR(dir_block);
2587         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2588         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2589         set_nlink(inode, 2);
2590         if (csum_size) {
2591                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2592                 initialize_dirent_tail(t, blocksize);
2593         }
2594
2595         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2596         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2597         if (err)
2598                 goto out;
2599         set_buffer_verified(dir_block);
2600 out:
2601         brelse(dir_block);
2602         return err;
2603 }
2604
2605 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2606 {
2607         handle_t *handle;
2608         struct inode *inode;
2609         int err, credits, retries = 0;
2610
2611         if (EXT4_DIR_LINK_MAX(dir))
2612                 return -EMLINK;
2613
2614         err = dquot_initialize(dir);
2615         if (err)
2616                 return err;
2617
2618         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2619                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2620 retry:
2621         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2622                                             &dentry->d_name,
2623                                             0, NULL, EXT4_HT_DIR, credits);
2624         handle = ext4_journal_current_handle();
2625         err = PTR_ERR(inode);
2626         if (IS_ERR(inode))
2627                 goto out_stop;
2628
2629         inode->i_op = &ext4_dir_inode_operations;
2630         inode->i_fop = &ext4_dir_operations;
2631         err = ext4_init_new_dir(handle, dir, inode);
2632         if (err)
2633                 goto out_clear_inode;
2634         err = ext4_mark_inode_dirty(handle, inode);
2635         if (!err)
2636                 err = ext4_add_entry(handle, dentry, inode);
2637         if (err) {
2638 out_clear_inode:
2639                 clear_nlink(inode);
2640                 unlock_new_inode(inode);
2641                 ext4_mark_inode_dirty(handle, inode);
2642                 iput(inode);
2643                 goto out_stop;
2644         }
2645         ext4_inc_count(handle, dir);
2646         ext4_update_dx_flag(dir);
2647         err = ext4_mark_inode_dirty(handle, dir);
2648         if (err)
2649                 goto out_clear_inode;
2650         unlock_new_inode(inode);
2651         d_instantiate(dentry, inode);
2652         if (IS_DIRSYNC(dir))
2653                 ext4_handle_sync(handle);
2654
2655 out_stop:
2656         if (handle)
2657                 ext4_journal_stop(handle);
2658         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2659                 goto retry;
2660         return err;
2661 }
2662
2663 /*
2664  * routine to check that the specified directory is empty (for rmdir)
2665  */
2666 int ext4_empty_dir(struct inode *inode)
2667 {
2668         unsigned int offset;
2669         struct buffer_head *bh;
2670         struct ext4_dir_entry_2 *de, *de1;
2671         struct super_block *sb;
2672         int err = 0;
2673
2674         if (ext4_has_inline_data(inode)) {
2675                 int has_inline_data = 1;
2676
2677                 err = empty_inline_dir(inode, &has_inline_data);
2678                 if (has_inline_data)
2679                         return err;
2680         }
2681
2682         sb = inode->i_sb;
2683         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2684                 EXT4_ERROR_INODE(inode, "invalid size");
2685                 return 1;
2686         }
2687         bh = ext4_read_dirblock(inode, 0, EITHER);
2688         if (IS_ERR(bh))
2689                 return 1;
2690
2691         de = (struct ext4_dir_entry_2 *) bh->b_data;
2692         de1 = ext4_next_entry(de, sb->s_blocksize);
2693         if (le32_to_cpu(de->inode) != inode->i_ino ||
2694                         le32_to_cpu(de1->inode) == 0 ||
2695                         strcmp(".", de->name) || strcmp("..", de1->name)) {
2696                 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2697                 brelse(bh);
2698                 return 1;
2699         }
2700         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2701                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2702         de = ext4_next_entry(de1, sb->s_blocksize);
2703         while (offset < inode->i_size) {
2704                 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2705                         unsigned int lblock;
2706                         err = 0;
2707                         brelse(bh);
2708                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2709                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2710                         if (IS_ERR(bh))
2711                                 return 1;
2712                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2713                 }
2714                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2715                                          bh->b_data, bh->b_size, offset)) {
2716                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2717                                                          sb->s_blocksize);
2718                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2719                         continue;
2720                 }
2721                 if (le32_to_cpu(de->inode)) {
2722                         brelse(bh);
2723                         return 0;
2724                 }
2725                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2726                 de = ext4_next_entry(de, sb->s_blocksize);
2727         }
2728         brelse(bh);
2729         return 1;
2730 }
2731
2732 /*
2733  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2734  * such inodes, starting at the superblock, in case we crash before the
2735  * file is closed/deleted, or in case the inode truncate spans multiple
2736  * transactions and the last transaction is not recovered after a crash.
2737  *
2738  * At filesystem recovery time, we walk this list deleting unlinked
2739  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2740  *
2741  * Orphan list manipulation functions must be called under i_mutex unless
2742  * we are just creating the inode or deleting it.
2743  */
2744 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2745 {
2746         struct super_block *sb = inode->i_sb;
2747         struct ext4_sb_info *sbi = EXT4_SB(sb);
2748         struct ext4_iloc iloc;
2749         int err = 0, rc;
2750         bool dirty = false;
2751
2752         if (!sbi->s_journal || is_bad_inode(inode))
2753                 return 0;
2754
2755         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2756                      !inode_is_locked(inode));
2757         /*
2758          * Exit early if inode already is on orphan list. This is a big speedup
2759          * since we don't have to contend on the global s_orphan_lock.
2760          */
2761         if (!list_empty(&EXT4_I(inode)->i_orphan))
2762                 return 0;
2763
2764         /*
2765          * Orphan handling is only valid for files with data blocks
2766          * being truncated, or files being unlinked. Note that we either
2767          * hold i_mutex, or the inode can not be referenced from outside,
2768          * so i_nlink should not be bumped due to race
2769          */
2770         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2771                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2772
2773         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2774         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2775         if (err)
2776                 goto out;
2777
2778         err = ext4_reserve_inode_write(handle, inode, &iloc);
2779         if (err)
2780                 goto out;
2781
2782         mutex_lock(&sbi->s_orphan_lock);
2783         /*
2784          * Due to previous errors inode may be already a part of on-disk
2785          * orphan list. If so skip on-disk list modification.
2786          */
2787         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2788             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2789                 /* Insert this inode at the head of the on-disk orphan list */
2790                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2791                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2792                 dirty = true;
2793         }
2794         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2795         mutex_unlock(&sbi->s_orphan_lock);
2796
2797         if (dirty) {
2798                 err = ext4_handle_dirty_super(handle, sb);
2799                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2800                 if (!err)
2801                         err = rc;
2802                 if (err) {
2803                         /*
2804                          * We have to remove inode from in-memory list if
2805                          * addition to on disk orphan list failed. Stray orphan
2806                          * list entries can cause panics at unmount time.
2807                          */
2808                         mutex_lock(&sbi->s_orphan_lock);
2809                         list_del(&EXT4_I(inode)->i_orphan);
2810                         mutex_unlock(&sbi->s_orphan_lock);
2811                 }
2812         }
2813         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2814         jbd_debug(4, "orphan inode %lu will point to %d\n",
2815                         inode->i_ino, NEXT_ORPHAN(inode));
2816 out:
2817         ext4_std_error(sb, err);
2818         return err;
2819 }
2820
2821 /*
2822  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2823  * of such inodes stored on disk, because it is finally being cleaned up.
2824  */
2825 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2826 {
2827         struct list_head *prev;
2828         struct ext4_inode_info *ei = EXT4_I(inode);
2829         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2830         __u32 ino_next;
2831         struct ext4_iloc iloc;
2832         int err = 0;
2833
2834         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2835                 return 0;
2836
2837         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2838                      !inode_is_locked(inode));
2839         /* Do this quick check before taking global s_orphan_lock. */
2840         if (list_empty(&ei->i_orphan))
2841                 return 0;
2842
2843         if (handle) {
2844                 /* Grab inode buffer early before taking global s_orphan_lock */
2845                 err = ext4_reserve_inode_write(handle, inode, &iloc);
2846         }
2847
2848         mutex_lock(&sbi->s_orphan_lock);
2849         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2850
2851         prev = ei->i_orphan.prev;
2852         list_del_init(&ei->i_orphan);
2853
2854         /* If we're on an error path, we may not have a valid
2855          * transaction handle with which to update the orphan list on
2856          * disk, but we still need to remove the inode from the linked
2857          * list in memory. */
2858         if (!handle || err) {
2859                 mutex_unlock(&sbi->s_orphan_lock);
2860                 goto out_err;
2861         }
2862
2863         ino_next = NEXT_ORPHAN(inode);
2864         if (prev == &sbi->s_orphan) {
2865                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2866                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2867                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2868                 if (err) {
2869                         mutex_unlock(&sbi->s_orphan_lock);
2870                         goto out_brelse;
2871                 }
2872                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2873                 mutex_unlock(&sbi->s_orphan_lock);
2874                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2875         } else {
2876                 struct ext4_iloc iloc2;
2877                 struct inode *i_prev =
2878                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2879
2880                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2881                           i_prev->i_ino, ino_next);
2882                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2883                 if (err) {
2884                         mutex_unlock(&sbi->s_orphan_lock);
2885                         goto out_brelse;
2886                 }
2887                 NEXT_ORPHAN(i_prev) = ino_next;
2888                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2889                 mutex_unlock(&sbi->s_orphan_lock);
2890         }
2891         if (err)
2892                 goto out_brelse;
2893         NEXT_ORPHAN(inode) = 0;
2894         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2895 out_err:
2896         ext4_std_error(inode->i_sb, err);
2897         return err;
2898
2899 out_brelse:
2900         brelse(iloc.bh);
2901         goto out_err;
2902 }
2903
2904 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2905 {
2906         int retval;
2907         struct inode *inode;
2908         struct buffer_head *bh;
2909         struct ext4_dir_entry_2 *de;
2910         handle_t *handle = NULL;
2911
2912         /* Initialize quotas before so that eventual writes go in
2913          * separate transaction */
2914         retval = dquot_initialize(dir);
2915         if (retval)
2916                 return retval;
2917         retval = dquot_initialize(d_inode(dentry));
2918         if (retval)
2919                 return retval;
2920
2921         retval = -ENOENT;
2922         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2923         if (IS_ERR(bh))
2924                 return PTR_ERR(bh);
2925         if (!bh)
2926                 goto end_rmdir;
2927
2928         inode = d_inode(dentry);
2929
2930         retval = -EFSCORRUPTED;
2931         if (le32_to_cpu(de->inode) != inode->i_ino)
2932                 goto end_rmdir;
2933
2934         retval = -ENOTEMPTY;
2935         if (!ext4_empty_dir(inode))
2936                 goto end_rmdir;
2937
2938         handle = ext4_journal_start(dir, EXT4_HT_DIR,
2939                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2940         if (IS_ERR(handle)) {
2941                 retval = PTR_ERR(handle);
2942                 handle = NULL;
2943                 goto end_rmdir;
2944         }
2945
2946         if (IS_DIRSYNC(dir))
2947                 ext4_handle_sync(handle);
2948
2949         retval = ext4_delete_entry(handle, dir, de, bh);
2950         if (retval)
2951                 goto end_rmdir;
2952         if (!EXT4_DIR_LINK_EMPTY(inode))
2953                 ext4_warning_inode(inode,
2954                              "empty directory '%.*s' has too many links (%u)",
2955                              dentry->d_name.len, dentry->d_name.name,
2956                              inode->i_nlink);
2957         inode->i_version++;
2958         clear_nlink(inode);
2959         /* There's no need to set i_disksize: the fact that i_nlink is
2960          * zero will ensure that the right thing happens during any
2961          * recovery. */
2962         inode->i_size = 0;
2963         ext4_orphan_add(handle, inode);
2964         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2965         ext4_mark_inode_dirty(handle, inode);
2966         ext4_dec_count(handle, dir);
2967         ext4_update_dx_flag(dir);
2968         ext4_mark_inode_dirty(handle, dir);
2969
2970 end_rmdir:
2971         brelse(bh);
2972         if (handle)
2973                 ext4_journal_stop(handle);
2974         return retval;
2975 }
2976
2977 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2978 {
2979         int retval;
2980         struct inode *inode;
2981         struct buffer_head *bh;
2982         struct ext4_dir_entry_2 *de;
2983         handle_t *handle = NULL;
2984
2985         trace_ext4_unlink_enter(dir, dentry);
2986         /* Initialize quotas before so that eventual writes go
2987          * in separate transaction */
2988         retval = dquot_initialize(dir);
2989         if (retval)
2990                 return retval;
2991         retval = dquot_initialize(d_inode(dentry));
2992         if (retval)
2993                 return retval;
2994
2995         retval = -ENOENT;
2996         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2997         if (IS_ERR(bh))
2998                 return PTR_ERR(bh);
2999         if (!bh)
3000                 goto end_unlink;
3001
3002         inode = d_inode(dentry);
3003
3004         retval = -EFSCORRUPTED;
3005         if (le32_to_cpu(de->inode) != inode->i_ino)
3006                 goto end_unlink;
3007
3008         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3009                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3010         if (IS_ERR(handle)) {
3011                 retval = PTR_ERR(handle);
3012                 handle = NULL;
3013                 goto end_unlink;
3014         }
3015
3016         if (IS_DIRSYNC(dir))
3017                 ext4_handle_sync(handle);
3018
3019         if (inode->i_nlink == 0) {
3020                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3021                                    dentry->d_name.len, dentry->d_name.name);
3022                 set_nlink(inode, 1);
3023         }
3024         retval = ext4_delete_entry(handle, dir, de, bh);
3025         if (retval)
3026                 goto end_unlink;
3027         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3028         ext4_update_dx_flag(dir);
3029         ext4_mark_inode_dirty(handle, dir);
3030         drop_nlink(inode);
3031         if (!inode->i_nlink)
3032                 ext4_orphan_add(handle, inode);
3033         inode->i_ctime = ext4_current_time(inode);
3034         ext4_mark_inode_dirty(handle, inode);
3035
3036 end_unlink:
3037         brelse(bh);
3038         if (handle)
3039                 ext4_journal_stop(handle);
3040         trace_ext4_unlink_exit(dentry, retval);
3041         return retval;
3042 }
3043
3044 static int ext4_symlink(struct inode *dir,
3045                         struct dentry *dentry, const char *symname)
3046 {
3047         handle_t *handle;
3048         struct inode *inode;
3049         int err, len = strlen(symname);
3050         int credits;
3051         bool encryption_required;
3052         struct ext4_str disk_link;
3053         struct ext4_encrypted_symlink_data *sd = NULL;
3054
3055         disk_link.len = len + 1;
3056         disk_link.name = (char *) symname;
3057
3058         encryption_required = (ext4_encrypted_inode(dir) ||
3059                                DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3060         if (encryption_required) {
3061                 err = ext4_get_encryption_info(dir);
3062                 if (err)
3063                         return err;
3064                 if (ext4_encryption_info(dir) == NULL)
3065                         return -EPERM;
3066                 disk_link.len = (ext4_fname_encrypted_size(dir, len) +
3067                                  sizeof(struct ext4_encrypted_symlink_data));
3068                 sd = kzalloc(disk_link.len, GFP_KERNEL);
3069                 if (!sd)
3070                         return -ENOMEM;
3071         }
3072
3073         if (disk_link.len > dir->i_sb->s_blocksize) {
3074                 err = -ENAMETOOLONG;
3075                 goto err_free_sd;
3076         }
3077
3078         err = dquot_initialize(dir);
3079         if (err)
3080                 goto err_free_sd;
3081
3082         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3083                 /*
3084                  * For non-fast symlinks, we just allocate inode and put it on
3085                  * orphan list in the first transaction => we need bitmap,
3086                  * group descriptor, sb, inode block, quota blocks, and
3087                  * possibly selinux xattr blocks.
3088                  */
3089                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3090                           EXT4_XATTR_TRANS_BLOCKS;
3091         } else {
3092                 /*
3093                  * Fast symlink. We have to add entry to directory
3094                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3095                  * allocate new inode (bitmap, group descriptor, inode block,
3096                  * quota blocks, sb is already counted in previous macros).
3097                  */
3098                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3099                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3100         }
3101
3102         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3103                                             &dentry->d_name, 0, NULL,
3104                                             EXT4_HT_DIR, credits);
3105         handle = ext4_journal_current_handle();
3106         if (IS_ERR(inode)) {
3107                 if (handle)
3108                         ext4_journal_stop(handle);
3109                 err = PTR_ERR(inode);
3110                 goto err_free_sd;
3111         }
3112
3113         if (encryption_required) {
3114                 struct qstr istr;
3115                 struct ext4_str ostr;
3116
3117                 istr.name = (const unsigned char *) symname;
3118                 istr.len = len;
3119                 ostr.name = sd->encrypted_path;
3120                 ostr.len = disk_link.len;
3121                 err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
3122                 if (err < 0)
3123                         goto err_drop_inode;
3124                 sd->len = cpu_to_le16(ostr.len);
3125                 disk_link.name = (char *) sd;
3126                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3127         }
3128
3129         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3130                 if (!encryption_required)
3131                         inode->i_op = &ext4_symlink_inode_operations;
3132                 inode_nohighmem(inode);
3133                 ext4_set_aops(inode);
3134                 /*
3135                  * We cannot call page_symlink() with transaction started
3136                  * because it calls into ext4_write_begin() which can wait
3137                  * for transaction commit if we are running out of space
3138                  * and thus we deadlock. So we have to stop transaction now
3139                  * and restart it when symlink contents is written.
3140                  *
3141                  * To keep fs consistent in case of crash, we have to put inode
3142                  * to orphan list in the mean time.
3143                  */
3144                 drop_nlink(inode);
3145                 err = ext4_orphan_add(handle, inode);
3146                 ext4_journal_stop(handle);
3147                 handle = NULL;
3148                 if (err)
3149                         goto err_drop_inode;
3150                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3151                 if (err)
3152                         goto err_drop_inode;
3153                 /*
3154                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3155                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3156                  */
3157                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3158                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3159                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3160                 if (IS_ERR(handle)) {
3161                         err = PTR_ERR(handle);
3162                         handle = NULL;
3163                         goto err_drop_inode;
3164                 }
3165                 set_nlink(inode, 1);
3166                 err = ext4_orphan_del(handle, inode);
3167                 if (err)
3168                         goto err_drop_inode;
3169         } else {
3170                 /* clear the extent format for fast symlink */
3171                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3172                 if (!encryption_required) {
3173                         inode->i_op = &ext4_fast_symlink_inode_operations;
3174                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3175                 }
3176                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3177                        disk_link.len);
3178                 inode->i_size = disk_link.len - 1;
3179         }
3180         EXT4_I(inode)->i_disksize = inode->i_size;
3181         err = ext4_add_nondir(handle, dentry, inode);
3182         if (!err && IS_DIRSYNC(dir))
3183                 ext4_handle_sync(handle);
3184
3185         if (handle)
3186                 ext4_journal_stop(handle);
3187         kfree(sd);
3188         return err;
3189 err_drop_inode:
3190         if (handle)
3191                 ext4_journal_stop(handle);
3192         clear_nlink(inode);
3193         unlock_new_inode(inode);
3194         iput(inode);
3195 err_free_sd:
3196         kfree(sd);
3197         return err;
3198 }
3199
3200 static int ext4_link(struct dentry *old_dentry,
3201                      struct inode *dir, struct dentry *dentry)
3202 {
3203         handle_t *handle;
3204         struct inode *inode = d_inode(old_dentry);
3205         int err, retries = 0;
3206
3207         if (inode->i_nlink >= EXT4_LINK_MAX)
3208                 return -EMLINK;
3209         if (ext4_encrypted_inode(dir) &&
3210             !ext4_is_child_context_consistent_with_parent(dir, inode))
3211                 return -EPERM;
3212
3213        if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3214            (!projid_eq(EXT4_I(dir)->i_projid,
3215                        EXT4_I(old_dentry->d_inode)->i_projid)))
3216                 return -EXDEV;
3217
3218         err = dquot_initialize(dir);
3219         if (err)
3220                 return err;
3221
3222 retry:
3223         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3224                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3225                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3226         if (IS_ERR(handle))
3227                 return PTR_ERR(handle);
3228
3229         if (IS_DIRSYNC(dir))
3230                 ext4_handle_sync(handle);
3231
3232         inode->i_ctime = ext4_current_time(inode);
3233         ext4_inc_count(handle, inode);
3234         ihold(inode);
3235
3236         err = ext4_add_entry(handle, dentry, inode);
3237         if (!err) {
3238                 ext4_mark_inode_dirty(handle, inode);
3239                 /* this can happen only for tmpfile being
3240                  * linked the first time
3241                  */
3242                 if (inode->i_nlink == 1)
3243                         ext4_orphan_del(handle, inode);
3244                 d_instantiate(dentry, inode);
3245         } else {
3246                 drop_nlink(inode);
3247                 iput(inode);
3248         }
3249         ext4_journal_stop(handle);
3250         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3251                 goto retry;
3252         return err;
3253 }
3254
3255
3256 /*
3257  * Try to find buffer head where contains the parent block.
3258  * It should be the inode block if it is inlined or the 1st block
3259  * if it is a normal dir.
3260  */
3261 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3262                                         struct inode *inode,
3263                                         int *retval,
3264                                         struct ext4_dir_entry_2 **parent_de,
3265                                         int *inlined)
3266 {
3267         struct buffer_head *bh;
3268
3269         if (!ext4_has_inline_data(inode)) {
3270                 bh = ext4_read_dirblock(inode, 0, EITHER);
3271                 if (IS_ERR(bh)) {
3272                         *retval = PTR_ERR(bh);
3273                         return NULL;
3274                 }
3275                 *parent_de = ext4_next_entry(
3276                                         (struct ext4_dir_entry_2 *)bh->b_data,
3277                                         inode->i_sb->s_blocksize);
3278                 return bh;
3279         }
3280
3281         *inlined = 1;
3282         return ext4_get_first_inline_block(inode, parent_de, retval);
3283 }
3284
3285 struct ext4_renament {
3286         struct inode *dir;
3287         struct dentry *dentry;
3288         struct inode *inode;
3289         bool is_dir;
3290         int dir_nlink_delta;
3291
3292         /* entry for "dentry" */
3293         struct buffer_head *bh;
3294         struct ext4_dir_entry_2 *de;
3295         int inlined;
3296
3297         /* entry for ".." in inode if it's a directory */
3298         struct buffer_head *dir_bh;
3299         struct ext4_dir_entry_2 *parent_de;
3300         int dir_inlined;
3301 };
3302
3303 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3304 {
3305         int retval;
3306
3307         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3308                                               &retval, &ent->parent_de,
3309                                               &ent->dir_inlined);
3310         if (!ent->dir_bh)
3311                 return retval;
3312         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3313                 return -EFSCORRUPTED;
3314         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3315         return ext4_journal_get_write_access(handle, ent->dir_bh);
3316 }
3317
3318 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3319                                   unsigned dir_ino)
3320 {
3321         int retval;
3322
3323         ent->parent_de->inode = cpu_to_le32(dir_ino);
3324         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3325         if (!ent->dir_inlined) {
3326                 if (is_dx(ent->inode)) {
3327                         retval = ext4_handle_dirty_dx_node(handle,
3328                                                            ent->inode,
3329                                                            ent->dir_bh);
3330                 } else {
3331                         retval = ext4_handle_dirty_dirent_node(handle,
3332                                                                ent->inode,
3333                                                                ent->dir_bh);
3334                 }
3335         } else {
3336                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3337         }
3338         if (retval) {
3339                 ext4_std_error(ent->dir->i_sb, retval);
3340                 return retval;
3341         }
3342         return 0;
3343 }
3344
3345 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3346                        unsigned ino, unsigned file_type)
3347 {
3348         int retval;
3349
3350         BUFFER_TRACE(ent->bh, "get write access");
3351         retval = ext4_journal_get_write_access(handle, ent->bh);
3352         if (retval)
3353                 return retval;
3354         ent->de->inode = cpu_to_le32(ino);
3355         if (ext4_has_feature_filetype(ent->dir->i_sb))
3356                 ent->de->file_type = file_type;
3357         ent->dir->i_version++;
3358         ent->dir->i_ctime = ent->dir->i_mtime =
3359                 ext4_current_time(ent->dir);
3360         ext4_mark_inode_dirty(handle, ent->dir);
3361         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3362         if (!ent->inlined) {
3363                 retval = ext4_handle_dirty_dirent_node(handle,
3364                                                        ent->dir, ent->bh);
3365                 if (unlikely(retval)) {
3366                         ext4_std_error(ent->dir->i_sb, retval);
3367                         return retval;
3368                 }
3369         }
3370         brelse(ent->bh);
3371         ent->bh = NULL;
3372
3373         return 0;
3374 }
3375
3376 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3377                                   const struct qstr *d_name)
3378 {
3379         int retval = -ENOENT;
3380         struct buffer_head *bh;
3381         struct ext4_dir_entry_2 *de;
3382
3383         bh = ext4_find_entry(dir, d_name, &de, NULL);
3384         if (IS_ERR(bh))
3385                 return PTR_ERR(bh);
3386         if (bh) {
3387                 retval = ext4_delete_entry(handle, dir, de, bh);
3388                 brelse(bh);
3389         }
3390         return retval;
3391 }
3392
3393 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3394                                int force_reread)
3395 {
3396         int retval;
3397         /*
3398          * ent->de could have moved from under us during htree split, so make
3399          * sure that we are deleting the right entry.  We might also be pointing
3400          * to a stale entry in the unused part of ent->bh so just checking inum
3401          * and the name isn't enough.
3402          */
3403         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3404             ent->de->name_len != ent->dentry->d_name.len ||
3405             strncmp(ent->de->name, ent->dentry->d_name.name,
3406                     ent->de->name_len) ||
3407             force_reread) {
3408                 retval = ext4_find_delete_entry(handle, ent->dir,
3409                                                 &ent->dentry->d_name);
3410         } else {
3411                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3412                 if (retval == -ENOENT) {
3413                         retval = ext4_find_delete_entry(handle, ent->dir,
3414                                                         &ent->dentry->d_name);
3415                 }
3416         }
3417
3418         if (retval) {
3419                 ext4_warning_inode(ent->dir,
3420                                    "Deleting old file: nlink %d, error=%d",
3421                                    ent->dir->i_nlink, retval);
3422         }
3423 }
3424
3425 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3426 {
3427         if (ent->dir_nlink_delta) {
3428                 if (ent->dir_nlink_delta == -1)
3429                         ext4_dec_count(handle, ent->dir);
3430                 else
3431                         ext4_inc_count(handle, ent->dir);
3432                 ext4_mark_inode_dirty(handle, ent->dir);
3433         }
3434 }
3435
3436 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3437                                               int credits, handle_t **h)
3438 {
3439         struct inode *wh;
3440         handle_t *handle;
3441         int retries = 0;
3442
3443         /*
3444          * for inode block, sb block, group summaries,
3445          * and inode bitmap
3446          */
3447         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3448                     EXT4_XATTR_TRANS_BLOCKS + 4);
3449 retry:
3450         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3451                                          &ent->dentry->d_name, 0, NULL,
3452                                          EXT4_HT_DIR, credits);
3453
3454         handle = ext4_journal_current_handle();
3455         if (IS_ERR(wh)) {
3456                 if (handle)
3457                         ext4_journal_stop(handle);
3458                 if (PTR_ERR(wh) == -ENOSPC &&
3459                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3460                         goto retry;
3461         } else {
3462                 *h = handle;
3463                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3464                 wh->i_op = &ext4_special_inode_operations;
3465         }
3466         return wh;
3467 }
3468
3469 /*
3470  * Anybody can rename anything with this: the permission checks are left to the
3471  * higher-level routines.
3472  *
3473  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3474  * while new_{dentry,inode) refers to the destination dentry/inode
3475  * This comes from rename(const char *oldpath, const char *newpath)
3476  */
3477 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3478                        struct inode *new_dir, struct dentry *new_dentry,
3479                        unsigned int flags)
3480 {
3481         handle_t *handle = NULL;
3482         struct ext4_renament old = {
3483                 .dir = old_dir,
3484                 .dentry = old_dentry,
3485                 .inode = d_inode(old_dentry),
3486         };
3487         struct ext4_renament new = {
3488                 .dir = new_dir,
3489                 .dentry = new_dentry,
3490                 .inode = d_inode(new_dentry),
3491         };
3492         int force_reread;
3493         int retval;
3494         struct inode *whiteout = NULL;
3495         int credits;
3496         u8 old_file_type;
3497
3498         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3499             (!projid_eq(EXT4_I(new_dir)->i_projid,
3500                         EXT4_I(old_dentry->d_inode)->i_projid)))
3501                 return -EXDEV;
3502
3503         retval = dquot_initialize(old.dir);
3504         if (retval)
3505                 return retval;
3506         retval = dquot_initialize(new.dir);
3507         if (retval)
3508                 return retval;
3509
3510         /* Initialize quotas before so that eventual writes go
3511          * in separate transaction */
3512         if (new.inode) {
3513                 retval = dquot_initialize(new.inode);
3514                 if (retval)
3515                         return retval;
3516         }
3517
3518         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3519         if (IS_ERR(old.bh))
3520                 return PTR_ERR(old.bh);
3521         /*
3522          *  Check for inode number is _not_ due to possible IO errors.
3523          *  We might rmdir the source, keep it as pwd of some process
3524          *  and merrily kill the link to whatever was created under the
3525          *  same name. Goodbye sticky bit ;-<
3526          */
3527         retval = -ENOENT;
3528         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3529                 goto end_rename;
3530
3531         if ((old.dir != new.dir) &&
3532             ext4_encrypted_inode(new.dir) &&
3533             !ext4_is_child_context_consistent_with_parent(new.dir,
3534                                                           old.inode)) {
3535                 retval = -EPERM;
3536                 goto end_rename;
3537         }
3538
3539         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3540                                  &new.de, &new.inlined);
3541         if (IS_ERR(new.bh)) {
3542                 retval = PTR_ERR(new.bh);
3543                 new.bh = NULL;
3544                 goto end_rename;
3545         }
3546         if (new.bh) {
3547                 if (!new.inode) {
3548                         brelse(new.bh);
3549                         new.bh = NULL;
3550                 }
3551         }
3552         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3553                 ext4_alloc_da_blocks(old.inode);
3554
3555         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3556                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3557         if (!(flags & RENAME_WHITEOUT)) {
3558                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3559                 if (IS_ERR(handle)) {
3560                         retval = PTR_ERR(handle);
3561                         handle = NULL;
3562                         goto end_rename;
3563                 }
3564         } else {
3565                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3566                 if (IS_ERR(whiteout)) {
3567                         retval = PTR_ERR(whiteout);
3568                         whiteout = NULL;
3569                         goto end_rename;
3570                 }
3571         }
3572
3573         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3574                 ext4_handle_sync(handle);
3575
3576         if (S_ISDIR(old.inode->i_mode)) {
3577                 if (new.inode) {
3578                         retval = -ENOTEMPTY;
3579                         if (!ext4_empty_dir(new.inode))
3580                                 goto end_rename;
3581                 } else {
3582                         retval = -EMLINK;
3583                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3584                                 goto end_rename;
3585                 }
3586                 retval = ext4_rename_dir_prepare(handle, &old);
3587                 if (retval)
3588                         goto end_rename;
3589         }
3590         /*
3591          * If we're renaming a file within an inline_data dir and adding or
3592          * setting the new dirent causes a conversion from inline_data to
3593          * extents/blockmap, we need to force the dirent delete code to
3594          * re-read the directory, or else we end up trying to delete a dirent
3595          * from what is now the extent tree root (or a block map).
3596          */
3597         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3598                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3599
3600         old_file_type = old.de->file_type;
3601         if (whiteout) {
3602                 /*
3603                  * Do this before adding a new entry, so the old entry is sure
3604                  * to be still pointing to the valid old entry.
3605                  */
3606                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3607                                      EXT4_FT_CHRDEV);
3608                 if (retval)
3609                         goto end_rename;
3610                 ext4_mark_inode_dirty(handle, whiteout);
3611         }
3612         if (!new.bh) {
3613                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3614                 if (retval)
3615                         goto end_rename;
3616         } else {
3617                 retval = ext4_setent(handle, &new,
3618                                      old.inode->i_ino, old_file_type);
3619                 if (retval)
3620                         goto end_rename;
3621         }
3622         if (force_reread)
3623                 force_reread = !ext4_test_inode_flag(new.dir,
3624                                                      EXT4_INODE_INLINE_DATA);
3625
3626         /*
3627          * Like most other Unix systems, set the ctime for inodes on a
3628          * rename.
3629          */
3630         old.inode->i_ctime = ext4_current_time(old.inode);
3631         ext4_mark_inode_dirty(handle, old.inode);
3632
3633         if (!whiteout) {
3634                 /*
3635                  * ok, that's it
3636                  */
3637                 ext4_rename_delete(handle, &old, force_reread);
3638         }
3639
3640         if (new.inode) {
3641                 ext4_dec_count(handle, new.inode);
3642                 new.inode->i_ctime = ext4_current_time(new.inode);
3643         }
3644         old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3645         ext4_update_dx_flag(old.dir);
3646         if (old.dir_bh) {
3647                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3648                 if (retval)
3649                         goto end_rename;
3650
3651                 ext4_dec_count(handle, old.dir);
3652                 if (new.inode) {
3653                         /* checked ext4_empty_dir above, can't have another
3654                          * parent, ext4_dec_count() won't work for many-linked
3655                          * dirs */
3656                         clear_nlink(new.inode);
3657                 } else {
3658                         ext4_inc_count(handle, new.dir);
3659                         ext4_update_dx_flag(new.dir);
3660                         ext4_mark_inode_dirty(handle, new.dir);
3661                 }
3662         }
3663         ext4_mark_inode_dirty(handle, old.dir);
3664         if (new.inode) {
3665                 ext4_mark_inode_dirty(handle, new.inode);
3666                 if (!new.inode->i_nlink)
3667                         ext4_orphan_add(handle, new.inode);
3668         }
3669         retval = 0;
3670
3671 end_rename:
3672         brelse(old.dir_bh);
3673         brelse(old.bh);
3674         brelse(new.bh);
3675         if (whiteout) {
3676                 if (retval)
3677                         drop_nlink(whiteout);
3678                 unlock_new_inode(whiteout);
3679                 iput(whiteout);
3680         }
3681         if (handle)
3682                 ext4_journal_stop(handle);
3683         return retval;
3684 }
3685
3686 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3687                              struct inode *new_dir, struct dentry *new_dentry)
3688 {
3689         handle_t *handle = NULL;
3690         struct ext4_renament old = {
3691                 .dir = old_dir,
3692                 .dentry = old_dentry,
3693                 .inode = d_inode(old_dentry),
3694         };
3695         struct ext4_renament new = {
3696                 .dir = new_dir,
3697                 .dentry = new_dentry,
3698                 .inode = d_inode(new_dentry),
3699         };
3700         u8 new_file_type;
3701         int retval;
3702
3703         if ((ext4_encrypted_inode(old_dir) ||
3704              ext4_encrypted_inode(new_dir)) &&
3705             (old_dir != new_dir) &&
3706             (!ext4_is_child_context_consistent_with_parent(new_dir,
3707                                                            old.inode) ||
3708              !ext4_is_child_context_consistent_with_parent(old_dir,
3709                                                            new.inode)))
3710                 return -EPERM;
3711
3712         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3713              !projid_eq(EXT4_I(new_dir)->i_projid,
3714                         EXT4_I(old_dentry->d_inode)->i_projid)) ||
3715             (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3716              !projid_eq(EXT4_I(old_dir)->i_projid,
3717                         EXT4_I(new_dentry->d_inode)->i_projid)))
3718                 return -EXDEV;
3719
3720         retval = dquot_initialize(old.dir);
3721         if (retval)
3722                 return retval;
3723         retval = dquot_initialize(new.dir);
3724         if (retval)
3725                 return retval;
3726
3727         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3728                                  &old.de, &old.inlined);
3729         if (IS_ERR(old.bh))
3730                 return PTR_ERR(old.bh);
3731         /*
3732          *  Check for inode number is _not_ due to possible IO errors.
3733          *  We might rmdir the source, keep it as pwd of some process
3734          *  and merrily kill the link to whatever was created under the
3735          *  same name. Goodbye sticky bit ;-<
3736          */
3737         retval = -ENOENT;
3738         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3739                 goto end_rename;
3740
3741         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3742                                  &new.de, &new.inlined);
3743         if (IS_ERR(new.bh)) {
3744                 retval = PTR_ERR(new.bh);
3745                 new.bh = NULL;
3746                 goto end_rename;
3747         }
3748
3749         /* RENAME_EXCHANGE case: old *and* new must both exist */
3750         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3751                 goto end_rename;
3752
3753         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3754                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3755                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3756         if (IS_ERR(handle)) {
3757                 retval = PTR_ERR(handle);
3758                 handle = NULL;
3759                 goto end_rename;
3760         }
3761
3762         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3763                 ext4_handle_sync(handle);
3764
3765         if (S_ISDIR(old.inode->i_mode)) {
3766                 old.is_dir = true;
3767                 retval = ext4_rename_dir_prepare(handle, &old);
3768                 if (retval)
3769                         goto end_rename;
3770         }
3771         if (S_ISDIR(new.inode->i_mode)) {
3772                 new.is_dir = true;
3773                 retval = ext4_rename_dir_prepare(handle, &new);
3774                 if (retval)
3775                         goto end_rename;
3776         }
3777
3778         /*
3779          * Other than the special case of overwriting a directory, parents'
3780          * nlink only needs to be modified if this is a cross directory rename.
3781          */
3782         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3783                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3784                 new.dir_nlink_delta = -old.dir_nlink_delta;
3785                 retval = -EMLINK;
3786                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3787                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3788                         goto end_rename;
3789         }
3790
3791         new_file_type = new.de->file_type;
3792         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3793         if (retval)
3794                 goto end_rename;
3795
3796         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3797         if (retval)
3798                 goto end_rename;
3799
3800         /*
3801          * Like most other Unix systems, set the ctime for inodes on a
3802          * rename.
3803          */
3804         old.inode->i_ctime = ext4_current_time(old.inode);
3805         new.inode->i_ctime = ext4_current_time(new.inode);
3806         ext4_mark_inode_dirty(handle, old.inode);
3807         ext4_mark_inode_dirty(handle, new.inode);
3808
3809         if (old.dir_bh) {
3810                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3811                 if (retval)
3812                         goto end_rename;
3813         }
3814         if (new.dir_bh) {
3815                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3816                 if (retval)
3817                         goto end_rename;
3818         }
3819         ext4_update_dir_count(handle, &old);
3820         ext4_update_dir_count(handle, &new);
3821         retval = 0;
3822
3823 end_rename:
3824         brelse(old.dir_bh);
3825         brelse(new.dir_bh);
3826         brelse(old.bh);
3827         brelse(new.bh);
3828         if (handle)
3829                 ext4_journal_stop(handle);
3830         return retval;
3831 }
3832
3833 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3834                         struct inode *new_dir, struct dentry *new_dentry,
3835                         unsigned int flags)
3836 {
3837         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3838                 return -EINVAL;
3839
3840         if (flags & RENAME_EXCHANGE) {
3841                 return ext4_cross_rename(old_dir, old_dentry,
3842                                          new_dir, new_dentry);
3843         }
3844
3845         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3846 }
3847
3848 /*
3849  * directories can handle most operations...
3850  */
3851 const struct inode_operations ext4_dir_inode_operations = {
3852         .create         = ext4_create,
3853         .lookup         = ext4_lookup,
3854         .link           = ext4_link,
3855         .unlink         = ext4_unlink,
3856         .symlink        = ext4_symlink,
3857         .mkdir          = ext4_mkdir,
3858         .rmdir          = ext4_rmdir,
3859         .mknod          = ext4_mknod,
3860         .tmpfile        = ext4_tmpfile,
3861         .rename2        = ext4_rename2,
3862         .setattr        = ext4_setattr,
3863         .setxattr       = generic_setxattr,
3864         .getxattr       = generic_getxattr,
3865         .listxattr      = ext4_listxattr,
3866         .removexattr    = generic_removexattr,
3867         .get_acl        = ext4_get_acl,
3868         .set_acl        = ext4_set_acl,
3869         .fiemap         = ext4_fiemap,
3870 };
3871
3872 const struct inode_operations ext4_special_inode_operations = {
3873         .setattr        = ext4_setattr,
3874         .setxattr       = generic_setxattr,
3875         .getxattr       = generic_getxattr,
3876         .listxattr      = ext4_listxattr,
3877         .removexattr    = generic_removexattr,
3878         .get_acl        = ext4_get_acl,
3879         .set_acl        = ext4_set_acl,
3880 };