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/jbd2.h>
  30 #include <linux/time.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/stat.h>
  33 #include <linux/string.h>
  34 #include <linux/quotaops.h>
  35 #include <linux/buffer_head.h>
  36 #include <linux/bio.h>
  37 #include "ext4.h"
  38 #include "ext4_jbd2.h"
  39
  40 #include "xattr.h"
  41 #include "acl.h"
  42
  43 #include <trace/events/ext4.h>
  44 /*
  45  * define how far ahead to read directories while searching them.
  46  */
  47 #define NAMEI_RA_CHUNKS  2
  48 #define NAMEI_RA_BLOCKS  4
  49 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  50 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
  51
  52 static struct buffer_head *ext4_append(handle_t *handle,
  53                                         struct inode *inode,
  54                                         ext4_lblk_t *block, int *err)
  55 {
  56         struct buffer_head *bh;
  57
  58         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  59
  60         bh = ext4_bread(handle, inode, *block, 1, err);
  61         if (bh) {
  62                 inode->i_size += inode->i_sb->s_blocksize;
  63                 EXT4_I(inode)->i_disksize = inode->i_size;
  64                 *err = ext4_journal_get_write_access(handle, bh);
  65                 if (*err) {
  66                         brelse(bh);
  67                         bh = NULL;
  68                 }
  69         }
  70         return bh;
  71 }
  72
  73 #ifndef assert
  74 #define assert(test) J_ASSERT(test)
  75 #endif
  76
  77 #ifdef DX_DEBUG
  78 #define dxtrace(command) command
  79 #else
  80 #define dxtrace(command)
  81 #endif
  82
  83 struct fake_dirent
  84 {
  85         __le32 inode;
  86         __le16 rec_len;
  87         u8 name_len;
  88         u8 file_type;
  89 };
  90
  91 struct dx_countlimit
  92 {
  93         __le16 limit;
  94         __le16 count;
  95 };
  96
  97 struct dx_entry
  98 {
  99         __le32 hash;
 100         __le32 block;
 101 };
 102
 103 /*
 104  * dx_root_info is laid out so that if it should somehow get overlaid by a
 105  * dirent the two low bits of the hash version will be zero.  Therefore, the
 106  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 107  */
 108
 109 struct dx_root
 110 {
 111         struct fake_dirent dot;
 112         char dot_name[4];
 113         struct fake_dirent dotdot;
 114         char dotdot_name[4];
 115         struct dx_root_info
 116         {
 117                 __le32 reserved_zero;
 118                 u8 hash_version;
 119                 u8 info_length; /* 8 */
 120                 u8 indirect_levels;
 121                 u8 unused_flags;
 122         }
 123         info;
 124         struct dx_entry entries[0];
 125 };
 126
 127 struct dx_node
 128 {
 129         struct fake_dirent fake;
 130         struct dx_entry entries[0];
 131 };
 132
 133
 134 struct dx_frame
 135 {
 136         struct buffer_head *bh;
 137         struct dx_entry *entries;
 138         struct dx_entry *at;
 139 };
 140
 141 struct dx_map_entry
 142 {
 143         u32 hash;
 144         u16 offs;
 145         u16 size;
 146 };
 147
 148 /*
 149  * This goes at the end of each htree block.
 150  */
 151 struct dx_tail {
 152         u32 dt_reserved;
 153         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 154 };
 155
 156 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 157 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 158 static inline unsigned dx_get_hash(struct dx_entry *entry);
 159 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 160 static unsigned dx_get_count(struct dx_entry *entries);
 161 static unsigned dx_get_limit(struct dx_entry *entries);
 162 static void dx_set_count(struct dx_entry *entries, unsigned value);
 163 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 164 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 165 static unsigned dx_node_limit(struct inode *dir);
 166 static struct dx_frame *dx_probe(const struct qstr *d_name,
 167                                  struct inode *dir,
 168                                  struct dx_hash_info *hinfo,
 169                                  struct dx_frame *frame,
 170                                  int *err);
 171 static void dx_release(struct dx_frame *frames);
 172 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 173                        struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 174 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 175 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 176                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 177 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 178 static void dx_insert_block(struct dx_frame *frame,
 179                                         u32 hash, ext4_lblk_t block);
 180 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 181                                  struct dx_frame *frame,
 182                                  struct dx_frame *frames,
 183                                  __u32 *start_hash);
 184 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 185                 const struct qstr *d_name,
 186                 struct ext4_dir_entry_2 **res_dir,
 187                 int *err);
 188 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 189                              struct inode *inode);
 190
 191 /* checksumming functions */
 192 #define EXT4_DIRENT_TAIL(block, blocksize) \
 193         ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
 194                                         ((blocksize) - \
 195                                          sizeof(struct ext4_dir_entry_tail))))
 196
 197 static void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 198                                    unsigned int blocksize)
 199 {
 200         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 201         t->det_rec_len = ext4_rec_len_to_disk(
 202                         sizeof(struct ext4_dir_entry_tail), blocksize);
 203         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 204 }
 205
 206 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 207 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 208                                                    struct ext4_dir_entry *de)
 209 {
 210         struct ext4_dir_entry_tail *t;
 211
 212 #ifdef PARANOID
 213         struct ext4_dir_entry *d, *top;
 214
 215         d = de;
 216         top = (struct ext4_dir_entry *)(((void *)de) +
 217                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 218                 sizeof(struct ext4_dir_entry_tail)));
 219         while (d < top && d->rec_len)
 220                 d = (struct ext4_dir_entry *)(((void *)d) +
 221                     le16_to_cpu(d->rec_len));
 222
 223         if (d != top)
 224                 return NULL;
 225
 226         t = (struct ext4_dir_entry_tail *)d;
 227 #else
 228         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 229 #endif
 230
 231         if (t->det_reserved_zero1 ||
 232             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 233             t->det_reserved_zero2 ||
 234             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 235                 return NULL;
 236
 237         return t;
 238 }
 239
 240 static __le32 ext4_dirent_csum(struct inode *inode,
 241                                struct ext4_dir_entry *dirent, int size)
 242 {
 243         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 244         struct ext4_inode_info *ei = EXT4_I(inode);
 245         __u32 csum;
 246
 247         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 248         return cpu_to_le32(csum);
 249 }
 250
 251 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 252 {
 253         struct ext4_dir_entry_tail *t;
 254
 255         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 256                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 257                 return 1;
 258
 259         t = get_dirent_tail(inode, dirent);
 260         if (!t) {
 261                 EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
 262                                  "leaf for checksum.  Please run e2fsck -D.");
 263                 return 0;
 264         }
 265
 266         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 267                                                 (void *)t - (void *)dirent))
 268                 return 0;
 269
 270         return 1;
 271 }
 272
 273 static void ext4_dirent_csum_set(struct inode *inode,
 274                                  struct ext4_dir_entry *dirent)
 275 {
 276         struct ext4_dir_entry_tail *t;
 277
 278         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 279                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 280                 return;
 281
 282         t = get_dirent_tail(inode, dirent);
 283         if (!t) {
 284                 EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
 285                                  "leaf for checksum.  Please run e2fsck -D.");
 286                 return;
 287         }
 288
 289         t->det_checksum = ext4_dirent_csum(inode, dirent,
 290                                            (void *)t - (void *)dirent);
 291 }
 292
 293 static inline int ext4_handle_dirty_dirent_node(handle_t *handle,
 294                                                 struct inode *inode,
 295                                                 struct buffer_head *bh)
 296 {
 297         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 298         return ext4_handle_dirty_metadata(handle, inode, bh);
 299 }
 300
 301 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 302                                                struct ext4_dir_entry *dirent,
 303                                                int *offset)
 304 {
 305         struct ext4_dir_entry *dp;
 306         struct dx_root_info *root;
 307         int count_offset;
 308
 309         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 310                 count_offset = 8;
 311         else if (le16_to_cpu(dirent->rec_len) == 12) {
 312                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 313                 if (le16_to_cpu(dp->rec_len) !=
 314                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 315                         return NULL;
 316                 root = (struct dx_root_info *)(((void *)dp + 12));
 317                 if (root->reserved_zero ||
 318                     root->info_length != sizeof(struct dx_root_info))
 319                         return NULL;
 320                 count_offset = 32;
 321         } else
 322                 return NULL;
 323
 324         if (offset)
 325                 *offset = count_offset;
 326         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 327 }
 328
 329 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 330                            int count_offset, int count, struct dx_tail *t)
 331 {
 332         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 333         struct ext4_inode_info *ei = EXT4_I(inode);
 334         __u32 csum, old_csum;
 335         int size;
 336
 337         size = count_offset + (count * sizeof(struct dx_entry));
 338         old_csum = t->dt_checksum;
 339         t->dt_checksum = 0;
 340         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 341         csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
 342         t->dt_checksum = old_csum;
 343
 344         return cpu_to_le32(csum);
 345 }
 346
 347 static int ext4_dx_csum_verify(struct inode *inode,
 348                                struct ext4_dir_entry *dirent)
 349 {
 350         struct dx_countlimit *c;
 351         struct dx_tail *t;
 352         int count_offset, limit, count;
 353
 354         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 355                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 356                 return 1;
 357
 358         c = get_dx_countlimit(inode, dirent, &count_offset);
 359         if (!c) {
 360                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 361                 return 1;
 362         }
 363         limit = le16_to_cpu(c->limit);
 364         count = le16_to_cpu(c->count);
 365         if (count_offset + (limit * sizeof(struct dx_entry)) >
 366             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 367                 EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
 368                                  "tree checksum found.  Run e2fsck -D.");
 369                 return 1;
 370         }
 371         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 372
 373         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 374                                             count, t))
 375                 return 0;
 376         return 1;
 377 }
 378
 379 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 380 {
 381         struct dx_countlimit *c;
 382         struct dx_tail *t;
 383         int count_offset, limit, count;
 384
 385         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 386                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 387                 return;
 388
 389         c = get_dx_countlimit(inode, dirent, &count_offset);
 390         if (!c) {
 391                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 392                 return;
 393         }
 394         limit = le16_to_cpu(c->limit);
 395         count = le16_to_cpu(c->count);
 396         if (count_offset + (limit * sizeof(struct dx_entry)) >
 397             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 398                 EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
 399                                  "tree checksum.  Run e2fsck -D.");
 400                 return;
 401         }
 402         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 403
 404         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 405 }
 406
 407 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 408                                             struct inode *inode,
 409                                             struct buffer_head *bh)
 410 {
 411         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 412         return ext4_handle_dirty_metadata(handle, inode, bh);
 413 }
 414
 415 /*
 416  * p is at least 6 bytes before the end of page
 417  */
 418 static inline struct ext4_dir_entry_2 *
 419 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 420 {
 421         return (struct ext4_dir_entry_2 *)((char *)p +
 422                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 423 }
 424
 425 /*
 426  * Future: use high four bits of block for coalesce-on-delete flags
 427  * Mask them off for now.
 428  */
 429
 430 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 431 {
 432         return le32_to_cpu(entry->block) & 0x00ffffff;
 433 }
 434
 435 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 436 {
 437         entry->block = cpu_to_le32(value);
 438 }
 439
 440 static inline unsigned dx_get_hash(struct dx_entry *entry)
 441 {
 442         return le32_to_cpu(entry->hash);
 443 }
 444
 445 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 446 {
 447         entry->hash = cpu_to_le32(value);
 448 }
 449
 450 static inline unsigned dx_get_count(struct dx_entry *entries)
 451 {
 452         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 453 }
 454
 455 static inline unsigned dx_get_limit(struct dx_entry *entries)
 456 {
 457         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 458 }
 459
 460 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 461 {
 462         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 463 }
 464
 465 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 466 {
 467         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 468 }
 469
 470 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 471 {
 472         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 473                 EXT4_DIR_REC_LEN(2) - infosize;
 474
 475         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 476                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 477                 entry_space -= sizeof(struct dx_tail);
 478         return entry_space / sizeof(struct dx_entry);
 479 }
 480
 481 static inline unsigned dx_node_limit(struct inode *dir)
 482 {
 483         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 484
 485         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 486                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 487                 entry_space -= sizeof(struct dx_tail);
 488         return entry_space / sizeof(struct dx_entry);
 489 }
 490
 491 /*
 492  * Debug
 493  */
 494 #ifdef DX_DEBUG
 495 static void dx_show_index(char * label, struct dx_entry *entries)
 496 {
 497         int i, n = dx_get_count (entries);
 498         printk(KERN_DEBUG "%s index ", label);
 499         for (i = 0; i < n; i++) {
 500                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 501                                 0, (unsigned long)dx_get_block(entries + i));
 502         }
 503         printk("\n");
 504 }
 505
 506 struct stats
 507 {
 508         unsigned names;
 509         unsigned space;
 510         unsigned bcount;
 511 };
 512
 513 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
 514                                  int size, int show_names)
 515 {
 516         unsigned names = 0, space = 0;
 517         char *base = (char *) de;
 518         struct dx_hash_info h = *hinfo;
 519
 520         printk("names: ");
 521         while ((char *) de < base + size)
 522         {
 523                 if (de->inode)
 524                 {
 525                         if (show_names)
 526                         {
 527                                 int len = de->name_len;
 528                                 char *name = de->name;
 529                                 while (len--) printk("%c", *name++);
 530                                 ext4fs_dirhash(de->name, de->name_len, &h);
 531                                 printk(":%x.%u ", h.hash,
 532                                        (unsigned) ((char *) de - base));
 533                         }
 534                         space += EXT4_DIR_REC_LEN(de->name_len);
 535                         names++;
 536                 }
 537                 de = ext4_next_entry(de, size);
 538         }
 539         printk("(%i)\n", names);
 540         return (struct stats) { names, space, 1 };
 541 }
 542
 543 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 544                              struct dx_entry *entries, int levels)
 545 {
 546         unsigned blocksize = dir->i_sb->s_blocksize;
 547         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 548         unsigned bcount = 0;
 549         struct buffer_head *bh;
 550         int err;
 551         printk("%i indexed blocks...\n", count);
 552         for (i = 0; i < count; i++, entries++)
 553         {
 554                 ext4_lblk_t block = dx_get_block(entries);
 555                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 556                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 557                 struct stats stats;
 558                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 559                 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
 560                 stats = levels?
 561                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 562                    dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
 563                 names += stats.names;
 564                 space += stats.space;
 565                 bcount += stats.bcount;
 566                 brelse(bh);
 567         }
 568         if (bcount)
 569                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 570                        levels ? "" : "   ", names, space/bcount,
 571                        (space/bcount)*100/blocksize);
 572         return (struct stats) { names, space, bcount};
 573 }
 574 #endif /* DX_DEBUG */
 575
 576 /*
 577  * Probe for a directory leaf block to search.
 578  *
 579  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 580  * error in the directory index, and the caller should fall back to
 581  * searching the directory normally.  The callers of dx_probe **MUST**
 582  * check for this error code, and make sure it never gets reflected
 583  * back to userspace.
 584  */
 585 static struct dx_frame *
 586 dx_probe(const struct qstr *d_name, struct inode *dir,
 587          struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
 588 {
 589         unsigned count, indirect;
 590         struct dx_entry *at, *entries, *p, *q, *m;
 591         struct dx_root *root;
 592         struct buffer_head *bh;
 593         struct dx_frame *frame = frame_in;
 594         u32 hash;
 595
 596         frame->bh = NULL;
 597         if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
 598                 goto fail;
 599         root = (struct dx_root *) bh->b_data;
 600         if (root->info.hash_version != DX_HASH_TEA &&
 601             root->info.hash_version != DX_HASH_HALF_MD4 &&
 602             root->info.hash_version != DX_HASH_LEGACY) {
 603                 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
 604                              root->info.hash_version);
 605                 brelse(bh);
 606                 *err = ERR_BAD_DX_DIR;
 607                 goto fail;
 608         }
 609         hinfo->hash_version = root->info.hash_version;
 610         if (hinfo->hash_version <= DX_HASH_TEA)
 611                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 612         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 613         if (d_name)
 614                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 615         hash = hinfo->hash;
 616
 617         if (root->info.unused_flags & 1) {
 618                 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
 619                              root->info.unused_flags);
 620                 brelse(bh);
 621                 *err = ERR_BAD_DX_DIR;
 622                 goto fail;
 623         }
 624
 625         if ((indirect = root->info.indirect_levels) > 1) {
 626                 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 627                              root->info.indirect_levels);
 628                 brelse(bh);
 629                 *err = ERR_BAD_DX_DIR;
 630                 goto fail;
 631         }
 632
 633         if (!buffer_verified(bh) &&
 634             !ext4_dx_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) {
 635                 ext4_warning(dir->i_sb, "Root failed checksum");
 636                 brelse(bh);
 637                 *err = ERR_BAD_DX_DIR;
 638                 goto fail;
 639         }
 640         set_buffer_verified(bh);
 641
 642         entries = (struct dx_entry *) (((char *)&root->info) +
 643                                        root->info.info_length);
 644
 645         if (dx_get_limit(entries) != dx_root_limit(dir,
 646                                                    root->info.info_length)) {
 647                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 648                 brelse(bh);
 649                 *err = ERR_BAD_DX_DIR;
 650                 goto fail;
 651         }
 652
 653         dxtrace(printk("Look up %x", hash));
 654         while (1)
 655         {
 656                 count = dx_get_count(entries);
 657                 if (!count || count > dx_get_limit(entries)) {
 658                         ext4_warning(dir->i_sb,
 659                                      "dx entry: no count or count > limit");
 660                         brelse(bh);
 661                         *err = ERR_BAD_DX_DIR;
 662                         goto fail2;
 663                 }
 664
 665                 p = entries + 1;
 666                 q = entries + count - 1;
 667                 while (p <= q)
 668                 {
 669                         m = p + (q - p)/2;
 670                         dxtrace(printk("."));
 671                         if (dx_get_hash(m) > hash)
 672                                 q = m - 1;
 673                         else
 674                                 p = m + 1;
 675                 }
 676
 677                 if (0) // linear search cross check
 678                 {
 679                         unsigned n = count - 1;
 680                         at = entries;
 681                         while (n--)
 682                         {
 683                                 dxtrace(printk(","));
 684                                 if (dx_get_hash(++at) > hash)
 685                                 {
 686                                         at--;
 687                                         break;
 688                                 }
 689                         }
 690                         assert (at == p - 1);
 691                 }
 692
 693                 at = p - 1;
 694                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 695                 frame->bh = bh;
 696                 frame->entries = entries;
 697                 frame->at = at;
 698                 if (!indirect--) return frame;
 699                 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
 700                         goto fail2;
 701                 at = entries = ((struct dx_node *) bh->b_data)->entries;
 702
 703                 if (!buffer_verified(bh) &&
 704                     !ext4_dx_csum_verify(dir,
 705                                          (struct ext4_dir_entry *)bh->b_data)) {
 706                         ext4_warning(dir->i_sb, "Node failed checksum");
 707                         brelse(bh);
 708                         *err = ERR_BAD_DX_DIR;
 709                         goto fail;
 710                 }
 711                 set_buffer_verified(bh);
 712
 713                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 714                         ext4_warning(dir->i_sb,
 715                                      "dx entry: limit != node limit");
 716                         brelse(bh);
 717                         *err = ERR_BAD_DX_DIR;
 718                         goto fail2;
 719                 }
 720                 frame++;
 721                 frame->bh = NULL;
 722         }
 723 fail2:
 724         while (frame >= frame_in) {
 725                 brelse(frame->bh);
 726                 frame--;
 727         }
 728 fail:
 729         if (*err == ERR_BAD_DX_DIR)
 730                 ext4_warning(dir->i_sb,
 731                              "Corrupt dir inode %lu, running e2fsck is "
 732                              "recommended.", dir->i_ino);
 733         return NULL;
 734 }
 735
 736 static void dx_release (struct dx_frame *frames)
 737 {
 738         if (frames[0].bh == NULL)
 739                 return;
 740
 741         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 742                 brelse(frames[1].bh);
 743         brelse(frames[0].bh);
 744 }
 745
 746 /*
 747  * This function increments the frame pointer to search the next leaf
 748  * block, and reads in the necessary intervening nodes if the search
 749  * should be necessary.  Whether or not the search is necessary is
 750  * controlled by the hash parameter.  If the hash value is even, then
 751  * the search is only continued if the next block starts with that
 752  * hash value.  This is used if we are searching for a specific file.
 753  *
 754  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 755  *
 756  * This function returns 1 if the caller should continue to search,
 757  * or 0 if it should not.  If there is an error reading one of the
 758  * index blocks, it will a negative error code.
 759  *
 760  * If start_hash is non-null, it will be filled in with the starting
 761  * hash of the next page.
 762  */
 763 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 764                                  struct dx_frame *frame,
 765                                  struct dx_frame *frames,
 766                                  __u32 *start_hash)
 767 {
 768         struct dx_frame *p;
 769         struct buffer_head *bh;
 770         int err, num_frames = 0;
 771         __u32 bhash;
 772
 773         p = frame;
 774         /*
 775          * Find the next leaf page by incrementing the frame pointer.
 776          * If we run out of entries in the interior node, loop around and
 777          * increment pointer in the parent node.  When we break out of
 778          * this loop, num_frames indicates the number of interior
 779          * nodes need to be read.
 780          */
 781         while (1) {
 782                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 783                         break;
 784                 if (p == frames)
 785                         return 0;
 786                 num_frames++;
 787                 p--;
 788         }
 789
 790         /*
 791          * If the hash is 1, then continue only if the next page has a
 792          * continuation hash of any value.  This is used for readdir
 793          * handling.  Otherwise, check to see if the hash matches the
 794          * desired contiuation hash.  If it doesn't, return since
 795          * there's no point to read in the successive index pages.
 796          */
 797         bhash = dx_get_hash(p->at);
 798         if (start_hash)
 799                 *start_hash = bhash;
 800         if ((hash & 1) == 0) {
 801                 if ((bhash & ~1) != hash)
 802                         return 0;
 803         }
 804         /*
 805          * If the hash is HASH_NB_ALWAYS, we always go to the next
 806          * block so no check is necessary
 807          */
 808         while (num_frames--) {
 809                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
 810                                       0, &err)))
 811                         return err; /* Failure */
 812
 813                 if (!buffer_verified(bh) &&
 814                     !ext4_dx_csum_verify(dir,
 815                                          (struct ext4_dir_entry *)bh->b_data)) {
 816                         ext4_warning(dir->i_sb, "Node failed checksum");
 817                         return -EIO;
 818                 }
 819                 set_buffer_verified(bh);
 820
 821                 p++;
 822                 brelse(p->bh);
 823                 p->bh = bh;
 824                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 825         }
 826         return 1;
 827 }
 828
 829
 830 /*
 831  * This function fills a red-black tree with information from a
 832  * directory block.  It returns the number directory entries loaded
 833  * into the tree.  If there is an error it is returned in err.
 834  */
 835 static int htree_dirblock_to_tree(struct file *dir_file,
 836                                   struct inode *dir, ext4_lblk_t block,
 837                                   struct dx_hash_info *hinfo,
 838                                   __u32 start_hash, __u32 start_minor_hash)
 839 {
 840         struct buffer_head *bh;
 841         struct ext4_dir_entry_2 *de, *top;
 842         int err, count = 0;
 843
 844         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 845                                                         (unsigned long)block));
 846         if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
 847                 return err;
 848
 849         if (!buffer_verified(bh) &&
 850             !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
 851                 return -EIO;
 852         set_buffer_verified(bh);
 853
 854         de = (struct ext4_dir_entry_2 *) bh->b_data;
 855         top = (struct ext4_dir_entry_2 *) ((char *) de +
 856                                            dir->i_sb->s_blocksize -
 857                                            EXT4_DIR_REC_LEN(0));
 858         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 859                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 860                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 861                                          + ((char *)de - bh->b_data))) {
 862                         /* On error, skip the f_pos to the next block. */
 863                         dir_file->f_pos = (dir_file->f_pos |
 864                                         (dir->i_sb->s_blocksize - 1)) + 1;
 865                         brelse(bh);
 866                         return count;
 867                 }
 868                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 869                 if ((hinfo->hash < start_hash) ||
 870                     ((hinfo->hash == start_hash) &&
 871                      (hinfo->minor_hash < start_minor_hash)))
 872                         continue;
 873                 if (de->inode == 0)
 874                         continue;
 875                 if ((err = ext4_htree_store_dirent(dir_file,
 876                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
 877                         brelse(bh);
 878                         return err;
 879                 }
 880                 count++;
 881         }
 882         brelse(bh);
 883         return count;
 884 }
 885
 886
 887 /*
 888  * This function fills a red-black tree with information from a
 889  * directory.  We start scanning the directory in hash order, starting
 890  * at start_hash and start_minor_hash.
 891  *
 892  * This function returns the number of entries inserted into the tree,
 893  * or a negative error code.
 894  */
 895 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 896                          __u32 start_minor_hash, __u32 *next_hash)
 897 {
 898         struct dx_hash_info hinfo;
 899         struct ext4_dir_entry_2 *de;
 900         struct dx_frame frames[2], *frame;
 901         struct inode *dir;
 902         ext4_lblk_t block;
 903         int count = 0;
 904         int ret, err;
 905         __u32 hashval;
 906
 907         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 908                        start_hash, start_minor_hash));
 909         dir = dir_file->f_path.dentry->d_inode;
 910         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
 911                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 912                 if (hinfo.hash_version <= DX_HASH_TEA)
 913                         hinfo.hash_version +=
 914                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
 915                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 916                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
 917                                                start_hash, start_minor_hash);
 918                 *next_hash = ~0;
 919                 return count;
 920         }
 921         hinfo.hash = start_hash;
 922         hinfo.minor_hash = 0;
 923         frame = dx_probe(NULL, dir, &hinfo, frames, &err);
 924         if (!frame)
 925                 return err;
 926
 927         /* Add '.' and '..' from the htree header */
 928         if (!start_hash && !start_minor_hash) {
 929                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 930                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 931                         goto errout;
 932                 count++;
 933         }
 934         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
 935                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 936                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
 937                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
 938                         goto errout;
 939                 count++;
 940         }
 941
 942         while (1) {
 943                 block = dx_get_block(frame->at);
 944                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
 945                                              start_hash, start_minor_hash);
 946                 if (ret < 0) {
 947                         err = ret;
 948                         goto errout;
 949                 }
 950                 count += ret;
 951                 hashval = ~0;
 952                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
 953                                             frame, frames, &hashval);
 954                 *next_hash = hashval;
 955                 if (ret < 0) {
 956                         err = ret;
 957                         goto errout;
 958                 }
 959                 /*
 960                  * Stop if:  (a) there are no more entries, or
 961                  * (b) we have inserted at least one entry and the
 962                  * next hash value is not a continuation
 963                  */
 964                 if ((ret == 0) ||
 965                     (count && ((hashval & 1) == 0)))
 966                         break;
 967         }
 968         dx_release(frames);
 969         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
 970                        "next hash: %x\n", count, *next_hash));
 971         return count;
 972 errout:
 973         dx_release(frames);
 974         return (err);
 975 }
 976
 977
 978 /*
 979  * Directory block splitting, compacting
 980  */
 981
 982 /*
 983  * Create map of hash values, offsets, and sizes, stored at end of block.
 984  * Returns number of entries mapped.
 985  */
 986 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 987                        struct dx_hash_info *hinfo,
 988                        struct dx_map_entry *map_tail)
 989 {
 990         int count = 0;
 991         char *base = (char *) de;
 992         struct dx_hash_info h = *hinfo;
 993
 994         while ((char *) de < base + blocksize) {
 995                 if (de->name_len && de->inode) {
 996                         ext4fs_dirhash(de->name, de->name_len, &h);
 997                         map_tail--;
 998                         map_tail->hash = h.hash;
 999                         map_tail->offs = ((char *) de - base)>>2;
1000                         map_tail->size = le16_to_cpu(de->rec_len);
1001                         count++;
1002                         cond_resched();
1003                 }
1004                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1005                 de = ext4_next_entry(de, blocksize);
1006         }
1007         return count;
1008 }
1009
1010 /* Sort map by hash value */
1011 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1012 {
1013         struct dx_map_entry *p, *q, *top = map + count - 1;
1014         int more;
1015         /* Combsort until bubble sort doesn't suck */
1016         while (count > 2) {
1017                 count = count*10/13;
1018                 if (count - 9 < 2) /* 9, 10 -> 11 */
1019                         count = 11;
1020                 for (p = top, q = p - count; q >= map; p--, q--)
1021                         if (p->hash < q->hash)
1022                                 swap(*p, *q);
1023         }
1024         /* Garden variety bubble sort */
1025         do {
1026                 more = 0;
1027                 q = top;
1028                 while (q-- > map) {
1029                         if (q[1].hash >= q[0].hash)
1030                                 continue;
1031                         swap(*(q+1), *q);
1032                         more = 1;
1033                 }
1034         } while(more);
1035 }
1036
1037 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1038 {
1039         struct dx_entry *entries = frame->entries;
1040         struct dx_entry *old = frame->at, *new = old + 1;
1041         int count = dx_get_count(entries);
1042
1043         assert(count < dx_get_limit(entries));
1044         assert(old < entries + count);
1045         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1046         dx_set_hash(new, hash);
1047         dx_set_block(new, block);
1048         dx_set_count(entries, count + 1);
1049 }
1050
1051 static void ext4_update_dx_flag(struct inode *inode)
1052 {
1053         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
1054                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
1055                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
1056 }
1057
1058 /*
1059  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1060  *
1061  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1062  * `de != NULL' is guaranteed by caller.
1063  */
1064 static inline int ext4_match (int len, const char * const name,
1065                               struct ext4_dir_entry_2 * de)
1066 {
1067         if (len != de->name_len)
1068                 return 0;
1069         if (!de->inode)
1070                 return 0;
1071         return !memcmp(name, de->name, len);
1072 }
1073
1074 /*
1075  * Returns 0 if not found, -1 on failure, and 1 on success
1076  */
1077 static inline int search_dirblock(struct buffer_head *bh,
1078                                   struct inode *dir,
1079                                   const struct qstr *d_name,
1080                                   unsigned int offset,
1081                                   struct ext4_dir_entry_2 ** res_dir)
1082 {
1083         struct ext4_dir_entry_2 * de;
1084         char * dlimit;
1085         int de_len;
1086         const char *name = d_name->name;
1087         int namelen = d_name->len;
1088
1089         de = (struct ext4_dir_entry_2 *) bh->b_data;
1090         dlimit = bh->b_data + dir->i_sb->s_blocksize;
1091         while ((char *) de < dlimit) {
1092                 /* this code is executed quadratically often */
1093                 /* do minimal checking `by hand' */
1094
1095                 if ((char *) de + namelen <= dlimit &&
1096                     ext4_match (namelen, name, de)) {
1097                         /* found a match - just to be sure, do a full check */
1098                         if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1099                                 return -1;
1100                         *res_dir = de;
1101                         return 1;
1102                 }
1103                 /* prevent looping on a bad block */
1104                 de_len = ext4_rec_len_from_disk(de->rec_len,
1105                                                 dir->i_sb->s_blocksize);
1106                 if (de_len <= 0)
1107                         return -1;
1108                 offset += de_len;
1109                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1110         }
1111         return 0;
1112 }
1113
1114
1115 /*
1116  *      ext4_find_entry()
1117  *
1118  * finds an entry in the specified directory with the wanted name. It
1119  * returns the cache buffer in which the entry was found, and the entry
1120  * itself (as a parameter - res_dir). It does NOT read the inode of the
1121  * entry - you'll have to do that yourself if you want to.
1122  *
1123  * The returned buffer_head has ->b_count elevated.  The caller is expected
1124  * to brelse() it when appropriate.
1125  */
1126 static struct buffer_head * ext4_find_entry (struct inode *dir,
1127                                         const struct qstr *d_name,
1128                                         struct ext4_dir_entry_2 ** res_dir)
1129 {
1130         struct super_block *sb;
1131         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1132         struct buffer_head *bh, *ret = NULL;
1133         ext4_lblk_t start, block, b;
1134         const u8 *name = d_name->name;
1135         int ra_max = 0;         /* Number of bh's in the readahead
1136                                    buffer, bh_use[] */
1137         int ra_ptr = 0;         /* Current index into readahead
1138                                    buffer */
1139         int num = 0;
1140         ext4_lblk_t  nblocks;
1141         int i, err;
1142         int namelen;
1143
1144         *res_dir = NULL;
1145         sb = dir->i_sb;
1146         namelen = d_name->len;
1147         if (namelen > EXT4_NAME_LEN)
1148                 return NULL;
1149         if ((namelen <= 2) && (name[0] == '.') &&
1150             (name[1] == '.' || name[1] == '\0')) {
1151                 /*
1152                  * "." or ".." will only be in the first block
1153                  * NFS may look up ".."; "." should be handled by the VFS
1154                  */
1155                 block = start = 0;
1156                 nblocks = 1;
1157                 goto restart;
1158         }
1159         if (is_dx(dir)) {
1160                 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
1161                 /*
1162                  * On success, or if the error was file not found,
1163                  * return.  Otherwise, fall back to doing a search the
1164                  * old fashioned way.
1165                  */
1166                 if (bh || (err != ERR_BAD_DX_DIR))
1167                         return bh;
1168                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1169                                "falling back\n"));
1170         }
1171         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1172         start = EXT4_I(dir)->i_dir_start_lookup;
1173         if (start >= nblocks)
1174                 start = 0;
1175         block = start;
1176 restart:
1177         do {
1178                 /*
1179                  * We deal with the read-ahead logic here.
1180                  */
1181                 if (ra_ptr >= ra_max) {
1182                         /* Refill the readahead buffer */
1183                         ra_ptr = 0;
1184                         b = block;
1185                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1186                                 /*
1187                                  * Terminate if we reach the end of the
1188                                  * directory and must wrap, or if our
1189                                  * search has finished at this block.
1190                                  */
1191                                 if (b >= nblocks || (num && block == start)) {
1192                                         bh_use[ra_max] = NULL;
1193                                         break;
1194                                 }
1195                                 num++;
1196                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
1197                                 bh_use[ra_max] = bh;
1198                                 if (bh)
1199                                         ll_rw_block(READ | REQ_META | REQ_PRIO,
1200                                                     1, &bh);
1201                         }
1202                 }
1203                 if ((bh = bh_use[ra_ptr++]) == NULL)
1204                         goto next;
1205                 wait_on_buffer(bh);
1206                 if (!buffer_uptodate(bh)) {
1207                         /* read error, skip block & hope for the best */
1208                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1209                                          (unsigned long) block);
1210                         brelse(bh);
1211                         goto next;
1212                 }
1213                 if (!buffer_verified(bh) &&
1214                     !ext4_dirent_csum_verify(dir,
1215                                 (struct ext4_dir_entry *)bh->b_data)) {
1216                         EXT4_ERROR_INODE(dir, "checksumming directory "
1217                                          "block %lu", (unsigned long)block);
1218                         brelse(bh);
1219                         goto next;
1220                 }
1221                 set_buffer_verified(bh);
1222                 i = search_dirblock(bh, dir, d_name,
1223                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1224                 if (i == 1) {
1225                         EXT4_I(dir)->i_dir_start_lookup = block;
1226                         ret = bh;
1227                         goto cleanup_and_exit;
1228                 } else {
1229                         brelse(bh);
1230                         if (i < 0)
1231                                 goto cleanup_and_exit;
1232                 }
1233         next:
1234                 if (++block >= nblocks)
1235                         block = 0;
1236         } while (block != start);
1237
1238         /*
1239          * If the directory has grown while we were searching, then
1240          * search the last part of the directory before giving up.
1241          */
1242         block = nblocks;
1243         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1244         if (block < nblocks) {
1245                 start = 0;
1246                 goto restart;
1247         }
1248
1249 cleanup_and_exit:
1250         /* Clean up the read-ahead blocks */
1251         for (; ra_ptr < ra_max; ra_ptr++)
1252                 brelse(bh_use[ra_ptr]);
1253         return ret;
1254 }
1255
1256 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1257                        struct ext4_dir_entry_2 **res_dir, int *err)
1258 {
1259         struct super_block * sb = dir->i_sb;
1260         struct dx_hash_info     hinfo;
1261         struct dx_frame frames[2], *frame;
1262         struct buffer_head *bh;
1263         ext4_lblk_t block;
1264         int retval;
1265
1266         if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1267                 return NULL;
1268         do {
1269                 block = dx_get_block(frame->at);
1270                 if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
1271                         goto errout;
1272
1273                 if (!buffer_verified(bh) &&
1274                     !ext4_dirent_csum_verify(dir,
1275                                 (struct ext4_dir_entry *)bh->b_data)) {
1276                         EXT4_ERROR_INODE(dir, "checksumming directory "
1277                                          "block %lu", (unsigned long)block);
1278                         brelse(bh);
1279                         *err = -EIO;
1280                         goto errout;
1281                 }
1282                 set_buffer_verified(bh);
1283                 retval = search_dirblock(bh, dir, d_name,
1284                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1285                                          res_dir);
1286                 if (retval == 1) {      /* Success! */
1287                         dx_release(frames);
1288                         return bh;
1289                 }
1290                 brelse(bh);
1291                 if (retval == -1) {
1292                         *err = ERR_BAD_DX_DIR;
1293                         goto errout;
1294                 }
1295
1296                 /* Check to see if we should continue to search */
1297                 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1298                                                frames, NULL);
1299                 if (retval < 0) {
1300                         ext4_warning(sb,
1301                              "error reading index page in directory #%lu",
1302                              dir->i_ino);
1303                         *err = retval;
1304                         goto errout;
1305                 }
1306         } while (retval == 1);
1307
1308         *err = -ENOENT;
1309 errout:
1310         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1311         dx_release (frames);
1312         return NULL;
1313 }
1314
1315 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1316 {
1317         struct inode *inode;
1318         struct ext4_dir_entry_2 *de;
1319         struct buffer_head *bh;
1320
1321         if (dentry->d_name.len > EXT4_NAME_LEN)
1322                 return ERR_PTR(-ENAMETOOLONG);
1323
1324         bh = ext4_find_entry(dir, &dentry->d_name, &de);
1325         inode = NULL;
1326         if (bh) {
1327                 __u32 ino = le32_to_cpu(de->inode);
1328                 brelse(bh);
1329                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1330                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1331                         return ERR_PTR(-EIO);
1332                 }
1333                 if (unlikely(ino == dir->i_ino)) {
1334                         EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
1335                                          dentry->d_name.len,
1336                                          dentry->d_name.name);
1337                         return ERR_PTR(-EIO);
1338                 }
1339                 inode = ext4_iget(dir->i_sb, ino);
1340                 if (inode == ERR_PTR(-ESTALE)) {
1341                         EXT4_ERROR_INODE(dir,
1342                                          "deleted inode referenced: %u",
1343                                          ino);
1344                         return ERR_PTR(-EIO);
1345                 }
1346         }
1347         return d_splice_alias(inode, dentry);
1348 }
1349
1350
1351 struct dentry *ext4_get_parent(struct dentry *child)
1352 {
1353         __u32 ino;
1354         static const struct qstr dotdot = QSTR_INIT("..", 2);
1355         struct ext4_dir_entry_2 * de;
1356         struct buffer_head *bh;
1357
1358         bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1359         if (!bh)
1360                 return ERR_PTR(-ENOENT);
1361         ino = le32_to_cpu(de->inode);
1362         brelse(bh);
1363
1364         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1365                 EXT4_ERROR_INODE(child->d_inode,
1366                                  "bad parent inode number: %u", ino);
1367                 return ERR_PTR(-EIO);
1368         }
1369
1370         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1371 }
1372
1373 #define S_SHIFT 12
1374 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1375         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1376         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1377         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1378         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1379         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1380         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1381         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1382 };
1383
1384 static inline void ext4_set_de_type(struct super_block *sb,
1385                                 struct ext4_dir_entry_2 *de,
1386                                 umode_t mode) {
1387         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1388                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1389 }
1390
1391 /*
1392  * Move count entries from end of map between two memory locations.
1393  * Returns pointer to last entry moved.
1394  */
1395 static struct ext4_dir_entry_2 *
1396 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1397                 unsigned blocksize)
1398 {
1399         unsigned rec_len = 0;
1400
1401         while (count--) {
1402                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1403                                                 (from + (map->offs<<2));
1404                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1405                 memcpy (to, de, rec_len);
1406                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1407                                 ext4_rec_len_to_disk(rec_len, blocksize);
1408                 de->inode = 0;
1409                 map++;
1410                 to += rec_len;
1411         }
1412         return (struct ext4_dir_entry_2 *) (to - rec_len);
1413 }
1414
1415 /*
1416  * Compact each dir entry in the range to the minimal rec_len.
1417  * Returns pointer to last entry in range.
1418  */
1419 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1420 {
1421         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1422         unsigned rec_len = 0;
1423
1424         prev = to = de;
1425         while ((char*)de < base + blocksize) {
1426                 next = ext4_next_entry(de, blocksize);
1427                 if (de->inode && de->name_len) {
1428                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1429                         if (de > to)
1430                                 memmove(to, de, rec_len);
1431                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1432                         prev = to;
1433                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1434                 }
1435                 de = next;
1436         }
1437         return prev;
1438 }
1439
1440 /*
1441  * Split a full leaf block to make room for a new dir entry.
1442  * Allocate a new block, and move entries so that they are approx. equally full.
1443  * Returns pointer to de in block into which the new entry will be inserted.
1444  */
1445 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1446                         struct buffer_head **bh,struct dx_frame *frame,
1447                         struct dx_hash_info *hinfo, int *error)
1448 {
1449         unsigned blocksize = dir->i_sb->s_blocksize;
1450         unsigned count, continued;
1451         struct buffer_head *bh2;
1452         ext4_lblk_t newblock;
1453         u32 hash2;
1454         struct dx_map_entry *map;
1455         char *data1 = (*bh)->b_data, *data2;
1456         unsigned split, move, size;
1457         struct ext4_dir_entry_2 *de = NULL, *de2;
1458         struct ext4_dir_entry_tail *t;
1459         int     csum_size = 0;
1460         int     err = 0, i;
1461
1462         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
1463                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1464                 csum_size = sizeof(struct ext4_dir_entry_tail);
1465
1466         bh2 = ext4_append (handle, dir, &newblock, &err);
1467         if (!(bh2)) {
1468                 brelse(*bh);
1469                 *bh = NULL;
1470                 goto errout;
1471         }
1472
1473         BUFFER_TRACE(*bh, "get_write_access");
1474         err = ext4_journal_get_write_access(handle, *bh);
1475         if (err)
1476                 goto journal_error;
1477
1478         BUFFER_TRACE(frame->bh, "get_write_access");
1479         err = ext4_journal_get_write_access(handle, frame->bh);
1480         if (err)
1481                 goto journal_error;
1482
1483         data2 = bh2->b_data;
1484
1485         /* create map in the end of data2 block */
1486         map = (struct dx_map_entry *) (data2 + blocksize);
1487         count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1488                              blocksize, hinfo, map);
1489         map -= count;
1490         dx_sort_map(map, count);
1491         /* Split the existing block in the middle, size-wise */
1492         size = 0;
1493         move = 0;
1494         for (i = count-1; i >= 0; i--) {
1495                 /* is more than half of this entry in 2nd half of the block? */
1496                 if (size + map[i].size/2 > blocksize/2)
1497                         break;
1498                 size += map[i].size;
1499                 move++;
1500         }
1501         /* map index at which we will split */
1502         split = count - move;
1503         hash2 = map[split].hash;
1504         continued = hash2 == map[split - 1].hash;
1505         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1506                         (unsigned long)dx_get_block(frame->at),
1507                                         hash2, split, count-split));
1508
1509         /* Fancy dance to stay within two buffers */
1510         de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1511         de = dx_pack_dirents(data1, blocksize);
1512         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1513                                            (char *) de,
1514                                            blocksize);
1515         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1516                                             (char *) de2,
1517                                             blocksize);
1518         if (csum_size) {
1519                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1520                 initialize_dirent_tail(t, blocksize);
1521
1522                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1523                 initialize_dirent_tail(t, blocksize);
1524         }
1525
1526         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1527         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1528
1529         /* Which block gets the new entry? */
1530         if (hinfo->hash >= hash2)
1531         {
1532                 swap(*bh, bh2);
1533                 de = de2;
1534         }
1535         dx_insert_block(frame, hash2 + continued, newblock);
1536         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1537         if (err)
1538                 goto journal_error;
1539         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1540         if (err)
1541                 goto journal_error;
1542         brelse(bh2);
1543         dxtrace(dx_show_index("frame", frame->entries));
1544         return de;
1545
1546 journal_error:
1547         brelse(*bh);
1548         brelse(bh2);
1549         *bh = NULL;
1550         ext4_std_error(dir->i_sb, err);
1551 errout:
1552         *error = err;
1553         return NULL;
1554 }
1555
1556 /*
1557  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1558  * it points to a directory entry which is guaranteed to be large
1559  * enough for new directory entry.  If de is NULL, then
1560  * add_dirent_to_buf will attempt search the directory block for
1561  * space.  It will return -ENOSPC if no space is available, and -EIO
1562  * and -EEXIST if directory entry already exists.
1563  */
1564 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1565                              struct inode *inode, struct ext4_dir_entry_2 *de,
1566                              struct buffer_head *bh)
1567 {
1568         struct inode    *dir = dentry->d_parent->d_inode;
1569         const char      *name = dentry->d_name.name;
1570         int             namelen = dentry->d_name.len;
1571         unsigned int    offset = 0;
1572         unsigned int    blocksize = dir->i_sb->s_blocksize;
1573         unsigned short  reclen;
1574         int             nlen, rlen, err;
1575         char            *top;
1576         int             csum_size = 0;
1577
1578         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1579                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1580                 csum_size = sizeof(struct ext4_dir_entry_tail);
1581
1582         reclen = EXT4_DIR_REC_LEN(namelen);
1583         if (!de) {
1584                 de = (struct ext4_dir_entry_2 *)bh->b_data;
1585                 top = bh->b_data + (blocksize - csum_size) - reclen;
1586                 while ((char *) de <= top) {
1587                         if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1588                                 return -EIO;
1589                         if (ext4_match(namelen, name, de))
1590                                 return -EEXIST;
1591                         nlen = EXT4_DIR_REC_LEN(de->name_len);
1592                         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1593                         if ((de->inode? rlen - nlen: rlen) >= reclen)
1594                                 break;
1595                         de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1596                         offset += rlen;
1597                 }
1598                 if ((char *) de > top)
1599                         return -ENOSPC;
1600         }
1601         BUFFER_TRACE(bh, "get_write_access");
1602         err = ext4_journal_get_write_access(handle, bh);
1603         if (err) {
1604                 ext4_std_error(dir->i_sb, err);
1605                 return err;
1606         }
1607
1608         /* By now the buffer is marked for journaling */
1609         nlen = EXT4_DIR_REC_LEN(de->name_len);
1610         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1611         if (de->inode) {
1612                 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1613                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1614                 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1615                 de = de1;
1616         }
1617         de->file_type = EXT4_FT_UNKNOWN;
1618         de->inode = cpu_to_le32(inode->i_ino);
1619         ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1620         de->name_len = namelen;
1621         memcpy(de->name, name, namelen);
1622         /*
1623          * XXX shouldn't update any times until successful
1624          * completion of syscall, but too many callers depend
1625          * on this.
1626          *
1627          * XXX similarly, too many callers depend on
1628          * ext4_new_inode() setting the times, but error
1629          * recovery deletes the inode, so the worst that can
1630          * happen is that the times are slightly out of date
1631          * and/or different from the directory change time.
1632          */
1633         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1634         ext4_update_dx_flag(dir);
1635         dir->i_version++;
1636         ext4_mark_inode_dirty(handle, dir);
1637         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1638         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1639         if (err)
1640                 ext4_std_error(dir->i_sb, err);
1641         return 0;
1642 }
1643
1644 /*
1645  * This converts a one block unindexed directory to a 3 block indexed
1646  * directory, and adds the dentry to the indexed directory.
1647  */
1648 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1649                             struct inode *inode, struct buffer_head *bh)
1650 {
1651         struct inode    *dir = dentry->d_parent->d_inode;
1652         const char      *name = dentry->d_name.name;
1653         int             namelen = dentry->d_name.len;
1654         struct buffer_head *bh2;
1655         struct dx_root  *root;
1656         struct dx_frame frames[2], *frame;
1657         struct dx_entry *entries;
1658         struct ext4_dir_entry_2 *de, *de2;
1659         struct ext4_dir_entry_tail *t;
1660         char            *data1, *top;
1661         unsigned        len;
1662         int             retval;
1663         unsigned        blocksize;
1664         struct dx_hash_info hinfo;
1665         ext4_lblk_t  block;
1666         struct fake_dirent *fde;
1667         int             csum_size = 0;
1668
1669         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1670                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1671                 csum_size = sizeof(struct ext4_dir_entry_tail);
1672
1673         blocksize =  dir->i_sb->s_blocksize;
1674         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1675         retval = ext4_journal_get_write_access(handle, bh);
1676         if (retval) {
1677                 ext4_std_error(dir->i_sb, retval);
1678                 brelse(bh);
1679                 return retval;
1680         }
1681         root = (struct dx_root *) bh->b_data;
1682
1683         /* The 0th block becomes the root, move the dirents out */
1684         fde = &root->dotdot;
1685         de = (struct ext4_dir_entry_2 *)((char *)fde +
1686                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1687         if ((char *) de >= (((char *) root) + blocksize)) {
1688                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1689                 brelse(bh);
1690                 return -EIO;
1691         }
1692         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1693
1694         /* Allocate new block for the 0th block's dirents */
1695         bh2 = ext4_append(handle, dir, &block, &retval);
1696         if (!(bh2)) {
1697                 brelse(bh);
1698                 return retval;
1699         }
1700         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1701         data1 = bh2->b_data;
1702
1703         memcpy (data1, de, len);
1704         de = (struct ext4_dir_entry_2 *) data1;
1705         top = data1 + len;
1706         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1707                 de = de2;
1708         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1709                                            (char *) de,
1710                                            blocksize);
1711
1712         if (csum_size) {
1713                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1714                 initialize_dirent_tail(t, blocksize);
1715         }
1716
1717         /* Initialize the root; the dot dirents already exist */
1718         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1719         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1720                                            blocksize);
1721         memset (&root->info, 0, sizeof(root->info));
1722         root->info.info_length = sizeof(root->info);
1723         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1724         entries = root->entries;
1725         dx_set_block(entries, 1);
1726         dx_set_count(entries, 1);
1727         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1728
1729         /* Initialize as for dx_probe */
1730         hinfo.hash_version = root->info.hash_version;
1731         if (hinfo.hash_version <= DX_HASH_TEA)
1732                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1733         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1734         ext4fs_dirhash(name, namelen, &hinfo);
1735         frame = frames;
1736         frame->entries = entries;
1737         frame->at = entries;
1738         frame->bh = bh;
1739         bh = bh2;
1740
1741         ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1742         ext4_handle_dirty_dirent_node(handle, dir, bh);
1743
1744         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1745         if (!de) {
1746                 /*
1747                  * Even if the block split failed, we have to properly write
1748                  * out all the changes we did so far. Otherwise we can end up
1749                  * with corrupted filesystem.
1750                  */
1751                 ext4_mark_inode_dirty(handle, dir);
1752                 dx_release(frames);
1753                 return retval;
1754         }
1755         dx_release(frames);
1756
1757         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1758         brelse(bh);
1759         return retval;
1760 }
1761
1762 /*
1763  *      ext4_add_entry()
1764  *
1765  * adds a file entry to the specified directory, using the same
1766  * semantics as ext4_find_entry(). It returns NULL if it failed.
1767  *
1768  * NOTE!! The inode part of 'de' is left at 0 - which means you
1769  * may not sleep between calling this and putting something into
1770  * the entry, as someone else might have used it while you slept.
1771  */
1772 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1773                           struct inode *inode)
1774 {
1775         struct inode *dir = dentry->d_parent->d_inode;
1776         struct buffer_head *bh;
1777         struct ext4_dir_entry_2 *de;
1778         struct ext4_dir_entry_tail *t;
1779         struct super_block *sb;
1780         int     retval;
1781         int     dx_fallback=0;
1782         unsigned blocksize;
1783         ext4_lblk_t block, blocks;
1784         int     csum_size = 0;
1785
1786         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1787                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1788                 csum_size = sizeof(struct ext4_dir_entry_tail);
1789
1790         sb = dir->i_sb;
1791         blocksize = sb->s_blocksize;
1792         if (!dentry->d_name.len)
1793                 return -EINVAL;
1794         if (is_dx(dir)) {
1795                 retval = ext4_dx_add_entry(handle, dentry, inode);
1796                 if (!retval || (retval != ERR_BAD_DX_DIR))
1797                         return retval;
1798                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1799                 dx_fallback++;
1800                 ext4_mark_inode_dirty(handle, dir);
1801         }
1802         blocks = dir->i_size >> sb->s_blocksize_bits;
1803         for (block = 0; block < blocks; block++) {
1804                 bh = ext4_bread(handle, dir, block, 0, &retval);
1805                 if(!bh)
1806                         return retval;
1807                 if (!buffer_verified(bh) &&
1808                     !ext4_dirent_csum_verify(dir,
1809                                 (struct ext4_dir_entry *)bh->b_data))
1810                         return -EIO;
1811                 set_buffer_verified(bh);
1812                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1813                 if (retval != -ENOSPC) {
1814                         brelse(bh);
1815                         return retval;
1816                 }
1817
1818                 if (blocks == 1 && !dx_fallback &&
1819                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1820                         return make_indexed_dir(handle, dentry, inode, bh);
1821                 brelse(bh);
1822         }
1823         bh = ext4_append(handle, dir, &block, &retval);
1824         if (!bh)
1825                 return retval;
1826         de = (struct ext4_dir_entry_2 *) bh->b_data;
1827         de->inode = 0;
1828         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
1829
1830         if (csum_size) {
1831                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
1832                 initialize_dirent_tail(t, blocksize);
1833         }
1834
1835         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1836         brelse(bh);
1837         if (retval == 0)
1838                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1839         return retval;
1840 }
1841
1842 /*
1843  * Returns 0 for success, or a negative error value
1844  */
1845 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1846                              struct inode *inode)
1847 {
1848         struct dx_frame frames[2], *frame;
1849         struct dx_entry *entries, *at;
1850         struct dx_hash_info hinfo;
1851         struct buffer_head *bh;
1852         struct inode *dir = dentry->d_parent->d_inode;
1853         struct super_block *sb = dir->i_sb;
1854         struct ext4_dir_entry_2 *de;
1855         int err;
1856
1857         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1858         if (!frame)
1859                 return err;
1860         entries = frame->entries;
1861         at = frame->at;
1862
1863         if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1864                 goto cleanup;
1865
1866         if (!buffer_verified(bh) &&
1867             !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
1868                 goto journal_error;
1869         set_buffer_verified(bh);
1870
1871         BUFFER_TRACE(bh, "get_write_access");
1872         err = ext4_journal_get_write_access(handle, bh);
1873         if (err)
1874                 goto journal_error;
1875
1876         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1877         if (err != -ENOSPC)
1878                 goto cleanup;
1879
1880         /* Block full, should compress but for now just split */
1881         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1882                        dx_get_count(entries), dx_get_limit(entries)));
1883         /* Need to split index? */
1884         if (dx_get_count(entries) == dx_get_limit(entries)) {
1885                 ext4_lblk_t newblock;
1886                 unsigned icount = dx_get_count(entries);
1887                 int levels = frame - frames;
1888                 struct dx_entry *entries2;
1889                 struct dx_node *node2;
1890                 struct buffer_head *bh2;
1891
1892                 if (levels && (dx_get_count(frames->entries) ==
1893                                dx_get_limit(frames->entries))) {
1894                         ext4_warning(sb, "Directory index full!");
1895                         err = -ENOSPC;
1896                         goto cleanup;
1897                 }
1898                 bh2 = ext4_append (handle, dir, &newblock, &err);
1899                 if (!(bh2))
1900                         goto cleanup;
1901                 node2 = (struct dx_node *)(bh2->b_data);
1902                 entries2 = node2->entries;
1903                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1904                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1905                                                            sb->s_blocksize);
1906                 BUFFER_TRACE(frame->bh, "get_write_access");
1907                 err = ext4_journal_get_write_access(handle, frame->bh);
1908                 if (err)
1909                         goto journal_error;
1910                 if (levels) {
1911                         unsigned icount1 = icount/2, icount2 = icount - icount1;
1912                         unsigned hash2 = dx_get_hash(entries + icount1);
1913                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1914                                        icount1, icount2));
1915
1916                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1917                         err = ext4_journal_get_write_access(handle,
1918                                                              frames[0].bh);
1919                         if (err)
1920                                 goto journal_error;
1921
1922                         memcpy((char *) entries2, (char *) (entries + icount1),
1923                                icount2 * sizeof(struct dx_entry));
1924                         dx_set_count(entries, icount1);
1925                         dx_set_count(entries2, icount2);
1926                         dx_set_limit(entries2, dx_node_limit(dir));
1927
1928                         /* Which index block gets the new entry? */
1929                         if (at - entries >= icount1) {
1930                                 frame->at = at = at - entries - icount1 + entries2;
1931                                 frame->entries = entries = entries2;
1932                                 swap(frame->bh, bh2);
1933                         }
1934                         dx_insert_block(frames + 0, hash2, newblock);
1935                         dxtrace(dx_show_index("node", frames[1].entries));
1936                         dxtrace(dx_show_index("node",
1937                                ((struct dx_node *) bh2->b_data)->entries));
1938                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
1939                         if (err)
1940                                 goto journal_error;
1941                         brelse (bh2);
1942                 } else {
1943                         dxtrace(printk(KERN_DEBUG
1944                                        "Creating second level index...\n"));
1945                         memcpy((char *) entries2, (char *) entries,
1946                                icount * sizeof(struct dx_entry));
1947                         dx_set_limit(entries2, dx_node_limit(dir));
1948
1949                         /* Set up root */
1950                         dx_set_count(entries, 1);
1951                         dx_set_block(entries + 0, newblock);
1952                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1953
1954                         /* Add new access path frame */
1955                         frame = frames + 1;
1956                         frame->at = at = at - entries + entries2;
1957                         frame->entries = entries = entries2;
1958                         frame->bh = bh2;
1959                         err = ext4_journal_get_write_access(handle,
1960                                                              frame->bh);
1961                         if (err)
1962                                 goto journal_error;
1963                 }
1964                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
1965                 if (err) {
1966                         ext4_std_error(inode->i_sb, err);
1967                         goto cleanup;
1968                 }
1969         }
1970         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1971         if (!de)
1972                 goto cleanup;
1973         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1974         goto cleanup;
1975
1976 journal_error:
1977         ext4_std_error(dir->i_sb, err);
1978 cleanup:
1979         if (bh)
1980                 brelse(bh);
1981         dx_release(frames);
1982         return err;
1983 }
1984
1985 /*
1986  * ext4_delete_entry deletes a directory entry by merging it with the
1987  * previous entry
1988  */
1989 static int ext4_delete_entry(handle_t *handle,
1990                              struct inode *dir,
1991                              struct ext4_dir_entry_2 *de_del,
1992                              struct buffer_head *bh)
1993 {
1994         struct ext4_dir_entry_2 *de, *pde;
1995         unsigned int blocksize = dir->i_sb->s_blocksize;
1996         int csum_size = 0;
1997         int i, err;
1998
1999         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2000                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2001                 csum_size = sizeof(struct ext4_dir_entry_tail);
2002
2003         i = 0;
2004         pde = NULL;
2005         de = (struct ext4_dir_entry_2 *) bh->b_data;
2006         while (i < bh->b_size - csum_size) {
2007                 if (ext4_check_dir_entry(dir, NULL, de, bh, i))
2008                         return -EIO;
2009                 if (de == de_del)  {
2010                         BUFFER_TRACE(bh, "get_write_access");
2011                         err = ext4_journal_get_write_access(handle, bh);
2012                         if (unlikely(err)) {
2013                                 ext4_std_error(dir->i_sb, err);
2014                                 return err;
2015                         }
2016                         if (pde)
2017                                 pde->rec_len = ext4_rec_len_to_disk(
2018                                         ext4_rec_len_from_disk(pde->rec_len,
2019                                                                blocksize) +
2020                                         ext4_rec_len_from_disk(de->rec_len,
2021                                                                blocksize),
2022                                         blocksize);
2023                         else
2024                                 de->inode = 0;
2025                         dir->i_version++;
2026                         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2027                         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2028                         if (unlikely(err)) {
2029                                 ext4_std_error(dir->i_sb, err);
2030                                 return err;
2031                         }
2032                         return 0;
2033                 }
2034                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2035                 pde = de;
2036                 de = ext4_next_entry(de, blocksize);
2037         }
2038         return -ENOENT;
2039 }
2040
2041 /*
2042  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2043  * since this indicates that nlinks count was previously 1.
2044  */
2045 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2046 {
2047         inc_nlink(inode);
2048         if (is_dx(inode) && inode->i_nlink > 1) {
2049                 /* limit is 16-bit i_links_count */
2050                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2051                         set_nlink(inode, 1);
2052                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2053                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2054                 }
2055         }
2056 }
2057
2058 /*
2059  * If a directory had nlink == 1, then we should let it be 1. This indicates
2060  * directory has >EXT4_LINK_MAX subdirs.
2061  */
2062 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2063 {
2064         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2065                 drop_nlink(inode);
2066 }
2067
2068
2069 static int ext4_add_nondir(handle_t *handle,
2070                 struct dentry *dentry, struct inode *inode)
2071 {
2072         int err = ext4_add_entry(handle, dentry, inode);
2073         if (!err) {
2074                 ext4_mark_inode_dirty(handle, inode);
2075                 unlock_new_inode(inode);
2076                 d_instantiate(dentry, inode);
2077                 return 0;
2078         }
2079         drop_nlink(inode);
2080         unlock_new_inode(inode);
2081         iput(inode);
2082         return err;
2083 }
2084
2085 /*
2086  * By the time this is called, we already have created
2087  * the directory cache entry for the new file, but it
2088  * is so far negative - it has no inode.
2089  *
2090  * If the create succeeds, we fill in the inode information
2091  * with d_instantiate().
2092  */
2093 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2094                        bool excl)
2095 {
2096         handle_t *handle;
2097         struct inode *inode;
2098         int err, retries = 0;
2099
2100         dquot_initialize(dir);
2101
2102 retry:
2103         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2104                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2105                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2106         if (IS_ERR(handle))
2107                 return PTR_ERR(handle);
2108
2109         if (IS_DIRSYNC(dir))
2110                 ext4_handle_sync(handle);
2111
2112         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2113         err = PTR_ERR(inode);
2114         if (!IS_ERR(inode)) {
2115                 inode->i_op = &ext4_file_inode_operations;
2116                 inode->i_fop = &ext4_file_operations;
2117                 ext4_set_aops(inode);
2118                 err = ext4_add_nondir(handle, dentry, inode);
2119         }
2120         ext4_journal_stop(handle);
2121         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2122                 goto retry;
2123         return err;
2124 }
2125
2126 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2127                       umode_t mode, dev_t rdev)
2128 {
2129         handle_t *handle;
2130         struct inode *inode;
2131         int err, retries = 0;
2132
2133         if (!new_valid_dev(rdev))
2134                 return -EINVAL;
2135
2136         dquot_initialize(dir);
2137
2138 retry:
2139         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2140                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2141                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2142         if (IS_ERR(handle))
2143                 return PTR_ERR(handle);
2144
2145         if (IS_DIRSYNC(dir))
2146                 ext4_handle_sync(handle);
2147
2148         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2149         err = PTR_ERR(inode);
2150         if (!IS_ERR(inode)) {
2151                 init_special_inode(inode, inode->i_mode, rdev);
2152 #ifdef CONFIG_EXT4_FS_XATTR
2153                 inode->i_op = &ext4_special_inode_operations;
2154 #endif
2155                 err = ext4_add_nondir(handle, dentry, inode);
2156         }
2157         ext4_journal_stop(handle);
2158         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2159                 goto retry;
2160         return err;
2161 }
2162
2163 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2164 {
2165         handle_t *handle;
2166         struct inode *inode;
2167         struct buffer_head *dir_block = NULL;
2168         struct ext4_dir_entry_2 *de;
2169         struct ext4_dir_entry_tail *t;
2170         unsigned int blocksize = dir->i_sb->s_blocksize;
2171         int csum_size = 0;
2172         int err, retries = 0;
2173
2174         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2175                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2176                 csum_size = sizeof(struct ext4_dir_entry_tail);
2177
2178         if (EXT4_DIR_LINK_MAX(dir))
2179                 return -EMLINK;
2180
2181         dquot_initialize(dir);
2182
2183 retry:
2184         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2185                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2186                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2187         if (IS_ERR(handle))
2188                 return PTR_ERR(handle);
2189
2190         if (IS_DIRSYNC(dir))
2191                 ext4_handle_sync(handle);
2192
2193         inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
2194                                &dentry->d_name, 0, NULL);
2195         err = PTR_ERR(inode);
2196         if (IS_ERR(inode))
2197                 goto out_stop;
2198
2199         inode->i_op = &ext4_dir_inode_operations;
2200         inode->i_fop = &ext4_dir_operations;
2201         inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
2202         dir_block = ext4_bread(handle, inode, 0, 1, &err);
2203         if (!dir_block)
2204                 goto out_clear_inode;
2205         BUFFER_TRACE(dir_block, "get_write_access");
2206         err = ext4_journal_get_write_access(handle, dir_block);
2207         if (err)
2208                 goto out_clear_inode;
2209         de = (struct ext4_dir_entry_2 *) dir_block->b_data;
2210         de->inode = cpu_to_le32(inode->i_ino);
2211         de->name_len = 1;
2212         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2213                                            blocksize);
2214         strcpy(de->name, ".");
2215         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2216         de = ext4_next_entry(de, blocksize);
2217         de->inode = cpu_to_le32(dir->i_ino);
2218         de->rec_len = ext4_rec_len_to_disk(blocksize -
2219                                            (csum_size + EXT4_DIR_REC_LEN(1)),
2220                                            blocksize);
2221         de->name_len = 2;
2222         strcpy(de->name, "..");
2223         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2224         set_nlink(inode, 2);
2225
2226         if (csum_size) {
2227                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2228                 initialize_dirent_tail(t, blocksize);
2229         }
2230
2231         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2232         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2233         if (err)
2234                 goto out_clear_inode;
2235         set_buffer_verified(dir_block);
2236         err = ext4_mark_inode_dirty(handle, inode);
2237         if (!err)
2238                 err = ext4_add_entry(handle, dentry, inode);
2239         if (err) {
2240 out_clear_inode:
2241                 clear_nlink(inode);
2242                 unlock_new_inode(inode);
2243                 ext4_mark_inode_dirty(handle, inode);
2244                 iput(inode);
2245                 goto out_stop;
2246         }
2247         ext4_inc_count(handle, dir);
2248         ext4_update_dx_flag(dir);
2249         err = ext4_mark_inode_dirty(handle, dir);
2250         if (err)
2251                 goto out_clear_inode;
2252         unlock_new_inode(inode);
2253         d_instantiate(dentry, inode);
2254 out_stop:
2255         brelse(dir_block);
2256         ext4_journal_stop(handle);
2257         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2258                 goto retry;
2259         return err;
2260 }
2261
2262 /*
2263  * routine to check that the specified directory is empty (for rmdir)
2264  */
2265 static int empty_dir(struct inode *inode)
2266 {
2267         unsigned int offset;
2268         struct buffer_head *bh;
2269         struct ext4_dir_entry_2 *de, *de1;
2270         struct super_block *sb;
2271         int err = 0;
2272
2273         sb = inode->i_sb;
2274         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
2275             !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
2276                 if (err)
2277                         EXT4_ERROR_INODE(inode,
2278                                 "error %d reading directory lblock 0", err);
2279                 else
2280                         ext4_warning(inode->i_sb,
2281                                      "bad directory (dir #%lu) - no data block",
2282                                      inode->i_ino);
2283                 return 1;
2284         }
2285         if (!buffer_verified(bh) &&
2286             !ext4_dirent_csum_verify(inode,
2287                         (struct ext4_dir_entry *)bh->b_data)) {
2288                 EXT4_ERROR_INODE(inode, "checksum error reading directory "
2289                                  "lblock 0");
2290                 return -EIO;
2291         }
2292         set_buffer_verified(bh);
2293         de = (struct ext4_dir_entry_2 *) bh->b_data;
2294         de1 = ext4_next_entry(de, sb->s_blocksize);
2295         if (le32_to_cpu(de->inode) != inode->i_ino ||
2296                         !le32_to_cpu(de1->inode) ||
2297                         strcmp(".", de->name) ||
2298                         strcmp("..", de1->name)) {
2299                 ext4_warning(inode->i_sb,
2300                              "bad directory (dir #%lu) - no `.' or `..'",
2301                              inode->i_ino);
2302                 brelse(bh);
2303                 return 1;
2304         }
2305         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2306                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2307         de = ext4_next_entry(de1, sb->s_blocksize);
2308         while (offset < inode->i_size) {
2309                 if (!bh ||
2310                     (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2311                         unsigned int lblock;
2312                         err = 0;
2313                         brelse(bh);
2314                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2315                         bh = ext4_bread(NULL, inode, lblock, 0, &err);
2316                         if (!bh) {
2317                                 if (err)
2318                                         EXT4_ERROR_INODE(inode,
2319                                                 "error %d reading directory "
2320                                                 "lblock %u", err, lblock);
2321                                 offset += sb->s_blocksize;
2322                                 continue;
2323                         }
2324                         if (!buffer_verified(bh) &&
2325                             !ext4_dirent_csum_verify(inode,
2326                                         (struct ext4_dir_entry *)bh->b_data)) {
2327                                 EXT4_ERROR_INODE(inode, "checksum error "
2328                                                  "reading directory lblock 0");
2329                                 return -EIO;
2330                         }
2331                         set_buffer_verified(bh);
2332                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2333                 }
2334                 if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
2335                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2336                                                          sb->s_blocksize);
2337                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2338                         continue;
2339                 }
2340                 if (le32_to_cpu(de->inode)) {
2341                         brelse(bh);
2342                         return 0;
2343                 }
2344                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2345                 de = ext4_next_entry(de, sb->s_blocksize);
2346         }
2347         brelse(bh);
2348         return 1;
2349 }
2350
2351 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
2352  * such inodes, starting at the superblock, in case we crash before the
2353  * file is closed/deleted, or in case the inode truncate spans multiple
2354  * transactions and the last transaction is not recovered after a crash.
2355  *
2356  * At filesystem recovery time, we walk this list deleting unlinked
2357  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2358  */
2359 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2360 {
2361         struct super_block *sb = inode->i_sb;
2362         struct ext4_iloc iloc;
2363         int err = 0, rc;
2364
2365         if (!ext4_handle_valid(handle))
2366                 return 0;
2367
2368         mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2369         if (!list_empty(&EXT4_I(inode)->i_orphan))
2370                 goto out_unlock;
2371
2372         /*
2373          * Orphan handling is only valid for files with data blocks
2374          * being truncated, or files being unlinked. Note that we either
2375          * hold i_mutex, or the inode can not be referenced from outside,
2376          * so i_nlink should not be bumped due to race
2377          */
2378         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2379                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2380
2381         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2382         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2383         if (err)
2384                 goto out_unlock;
2385
2386         err = ext4_reserve_inode_write(handle, inode, &iloc);
2387         if (err)
2388                 goto out_unlock;
2389         /*
2390          * Due to previous errors inode may be already a part of on-disk
2391          * orphan list. If so skip on-disk list modification.
2392          */
2393         if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2394                 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2395                         goto mem_insert;
2396
2397         /* Insert this inode at the head of the on-disk orphan list... */
2398         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2399         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2400         err = ext4_handle_dirty_super_now(handle, sb);
2401         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2402         if (!err)
2403                 err = rc;
2404
2405         /* Only add to the head of the in-memory list if all the
2406          * previous operations succeeded.  If the orphan_add is going to
2407          * fail (possibly taking the journal offline), we can't risk
2408          * leaving the inode on the orphan list: stray orphan-list
2409          * entries can cause panics at unmount time.
2410          *
2411          * This is safe: on error we're going to ignore the orphan list
2412          * anyway on the next recovery. */
2413 mem_insert:
2414         if (!err)
2415                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2416
2417         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2418         jbd_debug(4, "orphan inode %lu will point to %d\n",
2419                         inode->i_ino, NEXT_ORPHAN(inode));
2420 out_unlock:
2421         mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2422         ext4_std_error(inode->i_sb, err);
2423         return err;
2424 }
2425
2426 /*
2427  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2428  * of such inodes stored on disk, because it is finally being cleaned up.
2429  */
2430 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2431 {
2432         struct list_head *prev;
2433         struct ext4_inode_info *ei = EXT4_I(inode);
2434         struct ext4_sb_info *sbi;
2435         __u32 ino_next;
2436         struct ext4_iloc iloc;
2437         int err = 0;
2438
2439         /* ext4_handle_valid() assumes a valid handle_t pointer */
2440         if (handle && !ext4_handle_valid(handle))
2441                 return 0;
2442
2443         mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2444         if (list_empty(&ei->i_orphan))
2445                 goto out;
2446
2447         ino_next = NEXT_ORPHAN(inode);
2448         prev = ei->i_orphan.prev;
2449         sbi = EXT4_SB(inode->i_sb);
2450
2451         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2452
2453         list_del_init(&ei->i_orphan);
2454
2455         /* If we're on an error path, we may not have a valid
2456          * transaction handle with which to update the orphan list on
2457          * disk, but we still need to remove the inode from the linked
2458          * list in memory. */
2459         if (sbi->s_journal && !handle)
2460                 goto out;
2461
2462         err = ext4_reserve_inode_write(handle, inode, &iloc);
2463         if (err)
2464                 goto out_err;
2465
2466         if (prev == &sbi->s_orphan) {
2467                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2468                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2469                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2470                 if (err)
2471                         goto out_brelse;
2472                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2473                 err = ext4_handle_dirty_super_now(handle, inode->i_sb);
2474         } else {
2475                 struct ext4_iloc iloc2;
2476                 struct inode *i_prev =
2477                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2478
2479                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2480                           i_prev->i_ino, ino_next);
2481                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2482                 if (err)
2483                         goto out_brelse;
2484                 NEXT_ORPHAN(i_prev) = ino_next;
2485                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2486         }
2487         if (err)
2488                 goto out_brelse;
2489         NEXT_ORPHAN(inode) = 0;
2490         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2491
2492 out_err:
2493         ext4_std_error(inode->i_sb, err);
2494 out:
2495         mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2496         return err;
2497
2498 out_brelse:
2499         brelse(iloc.bh);
2500         goto out_err;
2501 }
2502
2503 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2504 {
2505         int retval;
2506         struct inode *inode;
2507         struct buffer_head *bh;
2508         struct ext4_dir_entry_2 *de;
2509         handle_t *handle;
2510
2511         /* Initialize quotas before so that eventual writes go in
2512          * separate transaction */
2513         dquot_initialize(dir);
2514         dquot_initialize(dentry->d_inode);
2515
2516         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2517         if (IS_ERR(handle))
2518                 return PTR_ERR(handle);
2519
2520         retval = -ENOENT;
2521         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2522         if (!bh)
2523                 goto end_rmdir;
2524
2525         if (IS_DIRSYNC(dir))
2526                 ext4_handle_sync(handle);
2527
2528         inode = dentry->d_inode;
2529
2530         retval = -EIO;
2531         if (le32_to_cpu(de->inode) != inode->i_ino)
2532                 goto end_rmdir;
2533
2534         retval = -ENOTEMPTY;
2535         if (!empty_dir(inode))
2536                 goto end_rmdir;
2537
2538         retval = ext4_delete_entry(handle, dir, de, bh);
2539         if (retval)
2540                 goto end_rmdir;
2541         if (!EXT4_DIR_LINK_EMPTY(inode))
2542                 ext4_warning(inode->i_sb,
2543                              "empty directory has too many links (%d)",
2544                              inode->i_nlink);
2545         inode->i_version++;
2546         clear_nlink(inode);
2547         /* There's no need to set i_disksize: the fact that i_nlink is
2548          * zero will ensure that the right thing happens during any
2549          * recovery. */
2550         inode->i_size = 0;
2551         ext4_orphan_add(handle, inode);
2552         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2553         ext4_mark_inode_dirty(handle, inode);
2554         ext4_dec_count(handle, dir);
2555         ext4_update_dx_flag(dir);
2556         ext4_mark_inode_dirty(handle, dir);
2557
2558 end_rmdir:
2559         ext4_journal_stop(handle);
2560         brelse(bh);
2561         return retval;
2562 }
2563
2564 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2565 {
2566         int retval;
2567         struct inode *inode;
2568         struct buffer_head *bh;
2569         struct ext4_dir_entry_2 *de;
2570         handle_t *handle;
2571
2572         trace_ext4_unlink_enter(dir, dentry);
2573         /* Initialize quotas before so that eventual writes go
2574          * in separate transaction */
2575         dquot_initialize(dir);
2576         dquot_initialize(dentry->d_inode);
2577
2578         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2579         if (IS_ERR(handle))
2580                 return PTR_ERR(handle);
2581
2582         if (IS_DIRSYNC(dir))
2583                 ext4_handle_sync(handle);
2584
2585         retval = -ENOENT;
2586         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2587         if (!bh)
2588                 goto end_unlink;
2589
2590         inode = dentry->d_inode;
2591
2592         retval = -EIO;
2593         if (le32_to_cpu(de->inode) != inode->i_ino)
2594                 goto end_unlink;
2595
2596         if (!inode->i_nlink) {
2597                 ext4_warning(inode->i_sb,
2598                              "Deleting nonexistent file (%lu), %d",
2599                              inode->i_ino, inode->i_nlink);
2600                 set_nlink(inode, 1);
2601         }
2602         retval = ext4_delete_entry(handle, dir, de, bh);
2603         if (retval)
2604                 goto end_unlink;
2605         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2606         ext4_update_dx_flag(dir);
2607         ext4_mark_inode_dirty(handle, dir);
2608         drop_nlink(inode);
2609         if (!inode->i_nlink)
2610                 ext4_orphan_add(handle, inode);
2611         inode->i_ctime = ext4_current_time(inode);
2612         ext4_mark_inode_dirty(handle, inode);
2613         retval = 0;
2614
2615 end_unlink:
2616         ext4_journal_stop(handle);
2617         brelse(bh);
2618         trace_ext4_unlink_exit(dentry, retval);
2619         return retval;
2620 }
2621
2622 static int ext4_symlink(struct inode *dir,
2623                         struct dentry *dentry, const char *symname)
2624 {
2625         handle_t *handle;
2626         struct inode *inode;
2627         int l, err, retries = 0;
2628         int credits;
2629
2630         l = strlen(symname)+1;
2631         if (l > dir->i_sb->s_blocksize)
2632                 return -ENAMETOOLONG;
2633
2634         dquot_initialize(dir);
2635
2636         if (l > EXT4_N_BLOCKS * 4) {
2637                 /*
2638                  * For non-fast symlinks, we just allocate inode and put it on
2639                  * orphan list in the first transaction => we need bitmap,
2640                  * group descriptor, sb, inode block, quota blocks, and
2641                  * possibly selinux xattr blocks.
2642                  */
2643                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2644                           EXT4_XATTR_TRANS_BLOCKS;
2645         } else {
2646                 /*
2647                  * Fast symlink. We have to add entry to directory
2648                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2649                  * allocate new inode (bitmap, group descriptor, inode block,
2650                  * quota blocks, sb is already counted in previous macros).
2651                  */
2652                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2653                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2654                           EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2655         }
2656 retry:
2657         handle = ext4_journal_start(dir, credits);
2658         if (IS_ERR(handle))
2659                 return PTR_ERR(handle);
2660
2661         if (IS_DIRSYNC(dir))
2662                 ext4_handle_sync(handle);
2663
2664         inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2665                                &dentry->d_name, 0, NULL);
2666         err = PTR_ERR(inode);
2667         if (IS_ERR(inode))
2668                 goto out_stop;
2669
2670         if (l > EXT4_N_BLOCKS * 4) {
2671                 inode->i_op = &ext4_symlink_inode_operations;
2672                 ext4_set_aops(inode);
2673                 /*
2674                  * We cannot call page_symlink() with transaction started
2675                  * because it calls into ext4_write_begin() which can wait
2676                  * for transaction commit if we are running out of space
2677                  * and thus we deadlock. So we have to stop transaction now
2678                  * and restart it when symlink contents is written.
2679                  *
2680                  * To keep fs consistent in case of crash, we have to put inode
2681                  * to orphan list in the mean time.
2682                  */
2683                 drop_nlink(inode);
2684                 err = ext4_orphan_add(handle, inode);
2685                 ext4_journal_stop(handle);
2686                 if (err)
2687                         goto err_drop_inode;
2688                 err = __page_symlink(inode, symname, l, 1);
2689                 if (err)
2690                         goto err_drop_inode;
2691                 /*
2692                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2693                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2694                  */
2695                 handle = ext4_journal_start(dir,
2696                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2697                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2698                 if (IS_ERR(handle)) {
2699                         err = PTR_ERR(handle);
2700                         goto err_drop_inode;
2701                 }
2702                 set_nlink(inode, 1);
2703                 err = ext4_orphan_del(handle, inode);
2704                 if (err) {
2705                         ext4_journal_stop(handle);
2706                         clear_nlink(inode);
2707                         goto err_drop_inode;
2708                 }
2709         } else {
2710                 /* clear the extent format for fast symlink */
2711                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2712                 inode->i_op = &ext4_fast_symlink_inode_operations;
2713                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2714                 inode->i_size = l-1;
2715         }
2716         EXT4_I(inode)->i_disksize = inode->i_size;
2717         err = ext4_add_nondir(handle, dentry, inode);
2718 out_stop:
2719         ext4_journal_stop(handle);
2720         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2721                 goto retry;
2722         return err;
2723 err_drop_inode:
2724         unlock_new_inode(inode);
2725         iput(inode);
2726         return err;
2727 }
2728
2729 static int ext4_link(struct dentry *old_dentry,
2730                      struct inode *dir, struct dentry *dentry)
2731 {
2732         handle_t *handle;
2733         struct inode *inode = old_dentry->d_inode;
2734         int err, retries = 0;
2735
2736         if (inode->i_nlink >= EXT4_LINK_MAX)
2737                 return -EMLINK;
2738
2739         dquot_initialize(dir);
2740
2741 retry:
2742         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2743                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2744         if (IS_ERR(handle))
2745                 return PTR_ERR(handle);
2746
2747         if (IS_DIRSYNC(dir))
2748                 ext4_handle_sync(handle);
2749
2750         inode->i_ctime = ext4_current_time(inode);
2751         ext4_inc_count(handle, inode);
2752         ihold(inode);
2753
2754         err = ext4_add_entry(handle, dentry, inode);
2755         if (!err) {
2756                 ext4_mark_inode_dirty(handle, inode);
2757                 d_instantiate(dentry, inode);
2758         } else {
2759                 drop_nlink(inode);
2760                 iput(inode);
2761         }
2762         ext4_journal_stop(handle);
2763         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2764                 goto retry;
2765         return err;
2766 }
2767
2768 #define PARENT_INO(buffer, size) \
2769         (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2770
2771 /*
2772  * Anybody can rename anything with this: the permission checks are left to the
2773  * higher-level routines.
2774  */
2775 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2776                        struct inode *new_dir, struct dentry *new_dentry)
2777 {
2778         handle_t *handle;
2779         struct inode *old_inode, *new_inode;
2780         struct buffer_head *old_bh, *new_bh, *dir_bh;
2781         struct ext4_dir_entry_2 *old_de, *new_de;
2782         int retval, force_da_alloc = 0;
2783
2784         dquot_initialize(old_dir);
2785         dquot_initialize(new_dir);
2786
2787         old_bh = new_bh = dir_bh = NULL;
2788
2789         /* Initialize quotas before so that eventual writes go
2790          * in separate transaction */
2791         if (new_dentry->d_inode)
2792                 dquot_initialize(new_dentry->d_inode);
2793         handle = ext4_journal_start(old_dir, 2 *
2794                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2795                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2796         if (IS_ERR(handle))
2797                 return PTR_ERR(handle);
2798
2799         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2800                 ext4_handle_sync(handle);
2801
2802         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2803         /*
2804          *  Check for inode number is _not_ due to possible IO errors.
2805          *  We might rmdir the source, keep it as pwd of some process
2806          *  and merrily kill the link to whatever was created under the
2807          *  same name. Goodbye sticky bit ;-<
2808          */
2809         old_inode = old_dentry->d_inode;
2810         retval = -ENOENT;
2811         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2812                 goto end_rename;
2813
2814         new_inode = new_dentry->d_inode;
2815         new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2816         if (new_bh) {
2817                 if (!new_inode) {
2818                         brelse(new_bh);
2819                         new_bh = NULL;
2820                 }
2821         }
2822         if (S_ISDIR(old_inode->i_mode)) {
2823                 if (new_inode) {
2824                         retval = -ENOTEMPTY;
2825                         if (!empty_dir(new_inode))
2826                                 goto end_rename;
2827                 }
2828                 retval = -EIO;
2829                 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2830                 if (!dir_bh)
2831                         goto end_rename;
2832                 if (!buffer_verified(dir_bh) &&
2833                     !ext4_dirent_csum_verify(old_inode,
2834                                 (struct ext4_dir_entry *)dir_bh->b_data))
2835                         goto end_rename;
2836                 set_buffer_verified(dir_bh);
2837                 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2838                                 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2839                         goto end_rename;
2840                 retval = -EMLINK;
2841                 if (!new_inode && new_dir != old_dir &&
2842                     EXT4_DIR_LINK_MAX(new_dir))
2843                         goto end_rename;
2844                 BUFFER_TRACE(dir_bh, "get_write_access");
2845                 retval = ext4_journal_get_write_access(handle, dir_bh);
2846                 if (retval)
2847                         goto end_rename;
2848         }
2849         if (!new_bh) {
2850                 retval = ext4_add_entry(handle, new_dentry, old_inode);
2851                 if (retval)
2852                         goto end_rename;
2853         } else {
2854                 BUFFER_TRACE(new_bh, "get write access");
2855                 retval = ext4_journal_get_write_access(handle, new_bh);
2856                 if (retval)
2857                         goto end_rename;
2858                 new_de->inode = cpu_to_le32(old_inode->i_ino);
2859                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2860                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
2861                         new_de->file_type = old_de->file_type;
2862                 new_dir->i_version++;
2863                 new_dir->i_ctime = new_dir->i_mtime =
2864                                         ext4_current_time(new_dir);
2865                 ext4_mark_inode_dirty(handle, new_dir);
2866                 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2867                 retval = ext4_handle_dirty_dirent_node(handle, new_dir, new_bh);
2868                 if (unlikely(retval)) {
2869                         ext4_std_error(new_dir->i_sb, retval);
2870                         goto end_rename;
2871                 }
2872                 brelse(new_bh);
2873                 new_bh = NULL;
2874         }
2875
2876         /*
2877          * Like most other Unix systems, set the ctime for inodes on a
2878          * rename.
2879          */
2880         old_inode->i_ctime = ext4_current_time(old_inode);
2881         ext4_mark_inode_dirty(handle, old_inode);
2882
2883         /*
2884          * ok, that's it
2885          */
2886         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2887             old_de->name_len != old_dentry->d_name.len ||
2888             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2889             (retval = ext4_delete_entry(handle, old_dir,
2890                                         old_de, old_bh)) == -ENOENT) {
2891                 /* old_de could have moved from under us during htree split, so
2892                  * make sure that we are deleting the right entry.  We might
2893                  * also be pointing to a stale entry in the unused part of
2894                  * old_bh so just checking inum and the name isn't enough. */
2895                 struct buffer_head *old_bh2;
2896                 struct ext4_dir_entry_2 *old_de2;
2897
2898                 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2899                 if (old_bh2) {
2900                         retval = ext4_delete_entry(handle, old_dir,
2901                                                    old_de2, old_bh2);
2902                         brelse(old_bh2);
2903                 }
2904         }
2905         if (retval) {
2906                 ext4_warning(old_dir->i_sb,
2907                                 "Deleting old file (%lu), %d, error=%d",
2908                                 old_dir->i_ino, old_dir->i_nlink, retval);
2909         }
2910
2911         if (new_inode) {
2912                 ext4_dec_count(handle, new_inode);
2913                 new_inode->i_ctime = ext4_current_time(new_inode);
2914         }
2915         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2916         ext4_update_dx_flag(old_dir);
2917         if (dir_bh) {
2918                 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2919                                                 cpu_to_le32(new_dir->i_ino);
2920                 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2921                 retval = ext4_handle_dirty_dirent_node(handle, old_inode,
2922                                                        dir_bh);
2923                 if (retval) {
2924                         ext4_std_error(old_dir->i_sb, retval);
2925                         goto end_rename;
2926                 }
2927                 ext4_dec_count(handle, old_dir);
2928                 if (new_inode) {
2929                         /* checked empty_dir above, can't have another parent,
2930                          * ext4_dec_count() won't work for many-linked dirs */
2931                         clear_nlink(new_inode);
2932                 } else {
2933                         ext4_inc_count(handle, new_dir);
2934                         ext4_update_dx_flag(new_dir);
2935                         ext4_mark_inode_dirty(handle, new_dir);
2936                 }
2937         }
2938         ext4_mark_inode_dirty(handle, old_dir);
2939         if (new_inode) {
2940                 ext4_mark_inode_dirty(handle, new_inode);
2941                 if (!new_inode->i_nlink)
2942                         ext4_orphan_add(handle, new_inode);
2943                 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2944                         force_da_alloc = 1;
2945         }
2946         retval = 0;
2947
2948 end_rename:
2949         brelse(dir_bh);
2950         brelse(old_bh);
2951         brelse(new_bh);
2952         ext4_journal_stop(handle);
2953         if (retval == 0 && force_da_alloc)
2954                 ext4_alloc_da_blocks(old_inode);
2955         return retval;
2956 }
2957
2958 /*
2959  * directories can handle most operations...
2960  */
2961 const struct inode_operations ext4_dir_inode_operations = {
2962         .create         = ext4_create,
2963         .lookup         = ext4_lookup,
2964         .link           = ext4_link,
2965         .unlink         = ext4_unlink,
2966         .symlink        = ext4_symlink,
2967         .mkdir          = ext4_mkdir,
2968         .rmdir          = ext4_rmdir,
2969         .mknod          = ext4_mknod,
2970         .rename         = ext4_rename,
2971         .setattr        = ext4_setattr,
2972 #ifdef CONFIG_EXT4_FS_XATTR
2973         .setxattr       = generic_setxattr,
2974         .getxattr       = generic_getxattr,
2975         .listxattr      = ext4_listxattr,
2976         .removexattr    = generic_removexattr,
2977 #endif
2978         .get_acl        = ext4_get_acl,
2979         .fiemap         = ext4_fiemap,
2980 };
2981
2982 const struct inode_operations ext4_special_inode_operations = {
2983         .setattr        = ext4_setattr,
2984 #ifdef CONFIG_EXT4_FS_XATTR
2985         .setxattr       = generic_setxattr,
2986         .getxattr       = generic_getxattr,
2987         .listxattr      = ext4_listxattr,
2988         .removexattr    = generic_removexattr,
2989 #endif
2990         .get_acl        = ext4_get_acl,
2991 };