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
  51 static struct buffer_head *ext4_append(handle_t *handle,
  52                                         struct inode *inode,
  53                                         ext4_lblk_t *block)
  54 {
  55         struct buffer_head *bh;
  56         int err = 0;
  57
  58         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  59                      ((inode->i_size >> 10) >=
  60                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
  61                 return ERR_PTR(-ENOSPC);
  62
  63         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  64
  65         bh = ext4_bread(handle, inode, *block, 1, &err);
  66         if (!bh)
  67                 return ERR_PTR(err);
  68         inode->i_size += inode->i_sb->s_blocksize;
  69         EXT4_I(inode)->i_disksize = inode->i_size;
  70         err = ext4_journal_get_write_access(handle, bh);
  71         if (err) {
  72                 brelse(bh);
  73                 ext4_std_error(inode->i_sb, err);
  74                 return ERR_PTR(err);
  75         }
  76         return bh;
  77 }
  78
  79 static int ext4_dx_csum_verify(struct inode *inode,
  80                                struct ext4_dir_entry *dirent);
  81
  82 typedef enum {
  83         EITHER, INDEX, DIRENT
  84 } dirblock_type_t;
  85
  86 #define ext4_read_dirblock(inode, block, type) \
  87         __ext4_read_dirblock((inode), (block), (type), __LINE__)
  88
  89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
  90                                               ext4_lblk_t block,
  91                                               dirblock_type_t type,
  92                                               unsigned int line)
  93 {
  94         struct buffer_head *bh;
  95         struct ext4_dir_entry *dirent;
  96         int err = 0, is_dx_block = 0;
  97
  98         bh = ext4_bread(NULL, inode, block, 0, &err);
  99         if (!bh) {
 100                 if (err == 0) {
 101                         ext4_error_inode(inode, __func__, line, block,
 102                                                "Directory hole found");
 103                         return ERR_PTR(-EIO);
 104                 }
 105                 __ext4_warning(inode->i_sb, __func__, line,
 106                                "error reading directory block "
 107                                "(ino %lu, block %lu)", inode->i_ino,
 108                                (unsigned long) block);
 109                 return ERR_PTR(err);
 110         }
 111         dirent = (struct ext4_dir_entry *) bh->b_data;
 112         /* Determine whether or not we have an index block */
 113         if (is_dx(inode)) {
 114                 if (block == 0)
 115                         is_dx_block = 1;
 116                 else if (ext4_rec_len_from_disk(dirent->rec_len,
 117                                                 inode->i_sb->s_blocksize) ==
 118                          inode->i_sb->s_blocksize)
 119                         is_dx_block = 1;
 120         }
 121         if (!is_dx_block && type == INDEX) {
 122                 ext4_error_inode(inode, __func__, line, block,
 123                        "directory leaf block found instead of index block");
 124                 return ERR_PTR(-EIO);
 125         }
 126         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 127                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) ||
 128             buffer_verified(bh))
 129                 return bh;
 130
 131         /*
 132          * An empty leaf block can get mistaken for a index block; for
 133          * this reason, we can only check the index checksum when the
 134          * caller is sure it should be an index block.
 135          */
 136         if (is_dx_block && type == INDEX) {
 137                 if (ext4_dx_csum_verify(inode, dirent))
 138                         set_buffer_verified(bh);
 139                 else {
 140                         ext4_error_inode(inode, __func__, line, block,
 141                                 "Directory index failed checksum");
 142                         brelse(bh);
 143                         return ERR_PTR(-EIO);
 144                 }
 145         }
 146         if (!is_dx_block) {
 147                 if (ext4_dirent_csum_verify(inode, dirent))
 148                         set_buffer_verified(bh);
 149                 else {
 150                         ext4_error_inode(inode, __func__, line, block,
 151                                 "Directory block failed checksum");
 152                         brelse(bh);
 153                         return ERR_PTR(-EIO);
 154                 }
 155         }
 156         return bh;
 157 }
 158
 159 #ifndef assert
 160 #define assert(test) J_ASSERT(test)
 161 #endif
 162
 163 #ifdef DX_DEBUG
 164 #define dxtrace(command) command
 165 #else
 166 #define dxtrace(command)
 167 #endif
 168
 169 struct fake_dirent
 170 {
 171         __le32 inode;
 172         __le16 rec_len;
 173         u8 name_len;
 174         u8 file_type;
 175 };
 176
 177 struct dx_countlimit
 178 {
 179         __le16 limit;
 180         __le16 count;
 181 };
 182
 183 struct dx_entry
 184 {
 185         __le32 hash;
 186         __le32 block;
 187 };
 188
 189 /*
 190  * dx_root_info is laid out so that if it should somehow get overlaid by a
 191  * dirent the two low bits of the hash version will be zero.  Therefore, the
 192  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 193  */
 194
 195 struct dx_root
 196 {
 197         struct fake_dirent dot;
 198         char dot_name[4];
 199         struct fake_dirent dotdot;
 200         char dotdot_name[4];
 201         struct dx_root_info
 202         {
 203                 __le32 reserved_zero;
 204                 u8 hash_version;
 205                 u8 info_length; /* 8 */
 206                 u8 indirect_levels;
 207                 u8 unused_flags;
 208         }
 209         info;
 210         struct dx_entry entries[0];
 211 };
 212
 213 struct dx_node
 214 {
 215         struct fake_dirent fake;
 216         struct dx_entry entries[0];
 217 };
 218
 219
 220 struct dx_frame
 221 {
 222         struct buffer_head *bh;
 223         struct dx_entry *entries;
 224         struct dx_entry *at;
 225 };
 226
 227 struct dx_map_entry
 228 {
 229         u32 hash;
 230         u16 offs;
 231         u16 size;
 232 };
 233
 234 /*
 235  * This goes at the end of each htree block.
 236  */
 237 struct dx_tail {
 238         u32 dt_reserved;
 239         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 240 };
 241
 242 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 243 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 244 static inline unsigned dx_get_hash(struct dx_entry *entry);
 245 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 246 static unsigned dx_get_count(struct dx_entry *entries);
 247 static unsigned dx_get_limit(struct dx_entry *entries);
 248 static void dx_set_count(struct dx_entry *entries, unsigned value);
 249 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 250 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 251 static unsigned dx_node_limit(struct inode *dir);
 252 static struct dx_frame *dx_probe(const struct qstr *d_name,
 253                                  struct inode *dir,
 254                                  struct dx_hash_info *hinfo,
 255                                  struct dx_frame *frame,
 256                                  int *err);
 257 static void dx_release(struct dx_frame *frames);
 258 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 259                        struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 260 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 261 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 262                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 263 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 264 static void dx_insert_block(struct dx_frame *frame,
 265                                         u32 hash, ext4_lblk_t block);
 266 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 267                                  struct dx_frame *frame,
 268                                  struct dx_frame *frames,
 269                                  __u32 *start_hash);
 270 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 271                 const struct qstr *d_name,
 272                 struct ext4_dir_entry_2 **res_dir,
 273                 int *err);
 274 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 275                              struct inode *inode);
 276
 277 /* checksumming functions */
 278 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 279                             unsigned int blocksize)
 280 {
 281         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 282         t->det_rec_len = ext4_rec_len_to_disk(
 283                         sizeof(struct ext4_dir_entry_tail), blocksize);
 284         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 285 }
 286
 287 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 288 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 289                                                    struct ext4_dir_entry *de)
 290 {
 291         struct ext4_dir_entry_tail *t;
 292
 293 #ifdef PARANOID
 294         struct ext4_dir_entry *d, *top;
 295
 296         d = de;
 297         top = (struct ext4_dir_entry *)(((void *)de) +
 298                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 299                 sizeof(struct ext4_dir_entry_tail)));
 300         while (d < top && d->rec_len)
 301                 d = (struct ext4_dir_entry *)(((void *)d) +
 302                     le16_to_cpu(d->rec_len));
 303
 304         if (d != top)
 305                 return NULL;
 306
 307         t = (struct ext4_dir_entry_tail *)d;
 308 #else
 309         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 310 #endif
 311
 312         if (t->det_reserved_zero1 ||
 313             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 314             t->det_reserved_zero2 ||
 315             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 316                 return NULL;
 317
 318         return t;
 319 }
 320
 321 static __le32 ext4_dirent_csum(struct inode *inode,
 322                                struct ext4_dir_entry *dirent, int size)
 323 {
 324         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 325         struct ext4_inode_info *ei = EXT4_I(inode);
 326         __u32 csum;
 327
 328         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 329         return cpu_to_le32(csum);
 330 }
 331
 332 static void warn_no_space_for_csum(struct inode *inode)
 333 {
 334         ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for "
 335                      "checksum.  Please run e2fsck -D.", inode->i_ino);
 336 }
 337
 338 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 339 {
 340         struct ext4_dir_entry_tail *t;
 341
 342         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 343                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 344                 return 1;
 345
 346         t = get_dirent_tail(inode, dirent);
 347         if (!t) {
 348                 warn_no_space_for_csum(inode);
 349                 return 0;
 350         }
 351
 352         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 353                                                 (void *)t - (void *)dirent))
 354                 return 0;
 355
 356         return 1;
 357 }
 358
 359 static void ext4_dirent_csum_set(struct inode *inode,
 360                                  struct ext4_dir_entry *dirent)
 361 {
 362         struct ext4_dir_entry_tail *t;
 363
 364         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 365                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 366                 return;
 367
 368         t = get_dirent_tail(inode, dirent);
 369         if (!t) {
 370                 warn_no_space_for_csum(inode);
 371                 return;
 372         }
 373
 374         t->det_checksum = ext4_dirent_csum(inode, dirent,
 375                                            (void *)t - (void *)dirent);
 376 }
 377
 378 int ext4_handle_dirty_dirent_node(handle_t *handle,
 379                                   struct inode *inode,
 380                                   struct buffer_head *bh)
 381 {
 382         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 383         return ext4_handle_dirty_metadata(handle, inode, bh);
 384 }
 385
 386 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 387                                                struct ext4_dir_entry *dirent,
 388                                                int *offset)
 389 {
 390         struct ext4_dir_entry *dp;
 391         struct dx_root_info *root;
 392         int count_offset;
 393
 394         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 395                 count_offset = 8;
 396         else if (le16_to_cpu(dirent->rec_len) == 12) {
 397                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 398                 if (le16_to_cpu(dp->rec_len) !=
 399                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 400                         return NULL;
 401                 root = (struct dx_root_info *)(((void *)dp + 12));
 402                 if (root->reserved_zero ||
 403                     root->info_length != sizeof(struct dx_root_info))
 404                         return NULL;
 405                 count_offset = 32;
 406         } else
 407                 return NULL;
 408
 409         if (offset)
 410                 *offset = count_offset;
 411         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 412 }
 413
 414 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 415                            int count_offset, int count, struct dx_tail *t)
 416 {
 417         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 418         struct ext4_inode_info *ei = EXT4_I(inode);
 419         __u32 csum;
 420         __le32 save_csum;
 421         int size;
 422
 423         size = count_offset + (count * sizeof(struct dx_entry));
 424         save_csum = t->dt_checksum;
 425         t->dt_checksum = 0;
 426         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 427         csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
 428         t->dt_checksum = save_csum;
 429
 430         return cpu_to_le32(csum);
 431 }
 432
 433 static int ext4_dx_csum_verify(struct inode *inode,
 434                                struct ext4_dir_entry *dirent)
 435 {
 436         struct dx_countlimit *c;
 437         struct dx_tail *t;
 438         int count_offset, limit, count;
 439
 440         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 441                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 442                 return 1;
 443
 444         c = get_dx_countlimit(inode, dirent, &count_offset);
 445         if (!c) {
 446                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 447                 return 1;
 448         }
 449         limit = le16_to_cpu(c->limit);
 450         count = le16_to_cpu(c->count);
 451         if (count_offset + (limit * sizeof(struct dx_entry)) >
 452             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 453                 warn_no_space_for_csum(inode);
 454                 return 1;
 455         }
 456         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 457
 458         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 459                                             count, t))
 460                 return 0;
 461         return 1;
 462 }
 463
 464 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 465 {
 466         struct dx_countlimit *c;
 467         struct dx_tail *t;
 468         int count_offset, limit, count;
 469
 470         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 471                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 472                 return;
 473
 474         c = get_dx_countlimit(inode, dirent, &count_offset);
 475         if (!c) {
 476                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 477                 return;
 478         }
 479         limit = le16_to_cpu(c->limit);
 480         count = le16_to_cpu(c->count);
 481         if (count_offset + (limit * sizeof(struct dx_entry)) >
 482             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 483                 warn_no_space_for_csum(inode);
 484                 return;
 485         }
 486         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 487
 488         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 489 }
 490
 491 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 492                                             struct inode *inode,
 493                                             struct buffer_head *bh)
 494 {
 495         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 496         return ext4_handle_dirty_metadata(handle, inode, bh);
 497 }
 498
 499 /*
 500  * p is at least 6 bytes before the end of page
 501  */
 502 static inline struct ext4_dir_entry_2 *
 503 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 504 {
 505         return (struct ext4_dir_entry_2 *)((char *)p +
 506                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 507 }
 508
 509 /*
 510  * Future: use high four bits of block for coalesce-on-delete flags
 511  * Mask them off for now.
 512  */
 513
 514 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 515 {
 516         return le32_to_cpu(entry->block) & 0x00ffffff;
 517 }
 518
 519 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 520 {
 521         entry->block = cpu_to_le32(value);
 522 }
 523
 524 static inline unsigned dx_get_hash(struct dx_entry *entry)
 525 {
 526         return le32_to_cpu(entry->hash);
 527 }
 528
 529 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 530 {
 531         entry->hash = cpu_to_le32(value);
 532 }
 533
 534 static inline unsigned dx_get_count(struct dx_entry *entries)
 535 {
 536         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 537 }
 538
 539 static inline unsigned dx_get_limit(struct dx_entry *entries)
 540 {
 541         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 542 }
 543
 544 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 545 {
 546         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 547 }
 548
 549 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 550 {
 551         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 552 }
 553
 554 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 555 {
 556         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 557                 EXT4_DIR_REC_LEN(2) - infosize;
 558
 559         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 560                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 561                 entry_space -= sizeof(struct dx_tail);
 562         return entry_space / sizeof(struct dx_entry);
 563 }
 564
 565 static inline unsigned dx_node_limit(struct inode *dir)
 566 {
 567         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 568
 569         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 570                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 571                 entry_space -= sizeof(struct dx_tail);
 572         return entry_space / sizeof(struct dx_entry);
 573 }
 574
 575 /*
 576  * Debug
 577  */
 578 #ifdef DX_DEBUG
 579 static void dx_show_index(char * label, struct dx_entry *entries)
 580 {
 581         int i, n = dx_get_count (entries);
 582         printk(KERN_DEBUG "%s index ", label);
 583         for (i = 0; i < n; i++) {
 584                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 585                                 0, (unsigned long)dx_get_block(entries + i));
 586         }
 587         printk("\n");
 588 }
 589
 590 struct stats
 591 {
 592         unsigned names;
 593         unsigned space;
 594         unsigned bcount;
 595 };
 596
 597 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
 598                                  int size, int show_names)
 599 {
 600         unsigned names = 0, space = 0;
 601         char *base = (char *) de;
 602         struct dx_hash_info h = *hinfo;
 603
 604         printk("names: ");
 605         while ((char *) de < base + size)
 606         {
 607                 if (de->inode)
 608                 {
 609                         if (show_names)
 610                         {
 611                                 int len = de->name_len;
 612                                 char *name = de->name;
 613                                 while (len--) printk("%c", *name++);
 614                                 ext4fs_dirhash(de->name, de->name_len, &h);
 615                                 printk(":%x.%u ", h.hash,
 616                                        (unsigned) ((char *) de - base));
 617                         }
 618                         space += EXT4_DIR_REC_LEN(de->name_len);
 619                         names++;
 620                 }
 621                 de = ext4_next_entry(de, size);
 622         }
 623         printk("(%i)\n", names);
 624         return (struct stats) { names, space, 1 };
 625 }
 626
 627 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 628                              struct dx_entry *entries, int levels)
 629 {
 630         unsigned blocksize = dir->i_sb->s_blocksize;
 631         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 632         unsigned bcount = 0;
 633         struct buffer_head *bh;
 634         int err;
 635         printk("%i indexed blocks...\n", count);
 636         for (i = 0; i < count; i++, entries++)
 637         {
 638                 ext4_lblk_t block = dx_get_block(entries);
 639                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 640                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 641                 struct stats stats;
 642                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 643                 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
 644                 stats = levels?
 645                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 646                    dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
 647                 names += stats.names;
 648                 space += stats.space;
 649                 bcount += stats.bcount;
 650                 brelse(bh);
 651         }
 652         if (bcount)
 653                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 654                        levels ? "" : "   ", names, space/bcount,
 655                        (space/bcount)*100/blocksize);
 656         return (struct stats) { names, space, bcount};
 657 }
 658 #endif /* DX_DEBUG */
 659
 660 /*
 661  * Probe for a directory leaf block to search.
 662  *
 663  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 664  * error in the directory index, and the caller should fall back to
 665  * searching the directory normally.  The callers of dx_probe **MUST**
 666  * check for this error code, and make sure it never gets reflected
 667  * back to userspace.
 668  */
 669 static struct dx_frame *
 670 dx_probe(const struct qstr *d_name, struct inode *dir,
 671          struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
 672 {
 673         unsigned count, indirect;
 674         struct dx_entry *at, *entries, *p, *q, *m;
 675         struct dx_root *root;
 676         struct buffer_head *bh;
 677         struct dx_frame *frame = frame_in;
 678         u32 hash;
 679
 680         frame->bh = NULL;
 681         bh = ext4_read_dirblock(dir, 0, INDEX);
 682         if (IS_ERR(bh)) {
 683                 *err = PTR_ERR(bh);
 684                 goto fail;
 685         }
 686         root = (struct dx_root *) bh->b_data;
 687         if (root->info.hash_version != DX_HASH_TEA &&
 688             root->info.hash_version != DX_HASH_HALF_MD4 &&
 689             root->info.hash_version != DX_HASH_LEGACY) {
 690                 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
 691                              root->info.hash_version);
 692                 brelse(bh);
 693                 *err = ERR_BAD_DX_DIR;
 694                 goto fail;
 695         }
 696         hinfo->hash_version = root->info.hash_version;
 697         if (hinfo->hash_version <= DX_HASH_TEA)
 698                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 699         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 700         if (d_name)
 701                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 702         hash = hinfo->hash;
 703
 704         if (root->info.unused_flags & 1) {
 705                 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
 706                              root->info.unused_flags);
 707                 brelse(bh);
 708                 *err = ERR_BAD_DX_DIR;
 709                 goto fail;
 710         }
 711
 712         if ((indirect = root->info.indirect_levels) > 1) {
 713                 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 714                              root->info.indirect_levels);
 715                 brelse(bh);
 716                 *err = ERR_BAD_DX_DIR;
 717                 goto fail;
 718         }
 719
 720         entries = (struct dx_entry *) (((char *)&root->info) +
 721                                        root->info.info_length);
 722
 723         if (dx_get_limit(entries) != dx_root_limit(dir,
 724                                                    root->info.info_length)) {
 725                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 726                 brelse(bh);
 727                 *err = ERR_BAD_DX_DIR;
 728                 goto fail;
 729         }
 730
 731         dxtrace(printk("Look up %x", hash));
 732         while (1)
 733         {
 734                 count = dx_get_count(entries);
 735                 if (!count || count > dx_get_limit(entries)) {
 736                         ext4_warning(dir->i_sb,
 737                                      "dx entry: no count or count > limit");
 738                         brelse(bh);
 739                         *err = ERR_BAD_DX_DIR;
 740                         goto fail2;
 741                 }
 742
 743                 p = entries + 1;
 744                 q = entries + count - 1;
 745                 while (p <= q)
 746                 {
 747                         m = p + (q - p)/2;
 748                         dxtrace(printk("."));
 749                         if (dx_get_hash(m) > hash)
 750                                 q = m - 1;
 751                         else
 752                                 p = m + 1;
 753                 }
 754
 755                 if (0) // linear search cross check
 756                 {
 757                         unsigned n = count - 1;
 758                         at = entries;
 759                         while (n--)
 760                         {
 761                                 dxtrace(printk(","));
 762                                 if (dx_get_hash(++at) > hash)
 763                                 {
 764                                         at--;
 765                                         break;
 766                                 }
 767                         }
 768                         assert (at == p - 1);
 769                 }
 770
 771                 at = p - 1;
 772                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 773                 frame->bh = bh;
 774                 frame->entries = entries;
 775                 frame->at = at;
 776                 if (!indirect--) return frame;
 777                 bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 778                 if (IS_ERR(bh)) {
 779                         *err = PTR_ERR(bh);
 780                         goto fail2;
 781                 }
 782                 entries = ((struct dx_node *) bh->b_data)->entries;
 783
 784                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 785                         ext4_warning(dir->i_sb,
 786                                      "dx entry: limit != node limit");
 787                         brelse(bh);
 788                         *err = ERR_BAD_DX_DIR;
 789                         goto fail2;
 790                 }
 791                 frame++;
 792                 frame->bh = NULL;
 793         }
 794 fail2:
 795         while (frame >= frame_in) {
 796                 brelse(frame->bh);
 797                 frame--;
 798         }
 799 fail:
 800         if (*err == ERR_BAD_DX_DIR)
 801                 ext4_warning(dir->i_sb,
 802                              "Corrupt dir inode %lu, running e2fsck is "
 803                              "recommended.", dir->i_ino);
 804         return NULL;
 805 }
 806
 807 static void dx_release (struct dx_frame *frames)
 808 {
 809         if (frames[0].bh == NULL)
 810                 return;
 811
 812         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 813                 brelse(frames[1].bh);
 814         brelse(frames[0].bh);
 815 }
 816
 817 /*
 818  * This function increments the frame pointer to search the next leaf
 819  * block, and reads in the necessary intervening nodes if the search
 820  * should be necessary.  Whether or not the search is necessary is
 821  * controlled by the hash parameter.  If the hash value is even, then
 822  * the search is only continued if the next block starts with that
 823  * hash value.  This is used if we are searching for a specific file.
 824  *
 825  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 826  *
 827  * This function returns 1 if the caller should continue to search,
 828  * or 0 if it should not.  If there is an error reading one of the
 829  * index blocks, it will a negative error code.
 830  *
 831  * If start_hash is non-null, it will be filled in with the starting
 832  * hash of the next page.
 833  */
 834 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 835                                  struct dx_frame *frame,
 836                                  struct dx_frame *frames,
 837                                  __u32 *start_hash)
 838 {
 839         struct dx_frame *p;
 840         struct buffer_head *bh;
 841         int num_frames = 0;
 842         __u32 bhash;
 843
 844         p = frame;
 845         /*
 846          * Find the next leaf page by incrementing the frame pointer.
 847          * If we run out of entries in the interior node, loop around and
 848          * increment pointer in the parent node.  When we break out of
 849          * this loop, num_frames indicates the number of interior
 850          * nodes need to be read.
 851          */
 852         while (1) {
 853                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 854                         break;
 855                 if (p == frames)
 856                         return 0;
 857                 num_frames++;
 858                 p--;
 859         }
 860
 861         /*
 862          * If the hash is 1, then continue only if the next page has a
 863          * continuation hash of any value.  This is used for readdir
 864          * handling.  Otherwise, check to see if the hash matches the
 865          * desired contiuation hash.  If it doesn't, return since
 866          * there's no point to read in the successive index pages.
 867          */
 868         bhash = dx_get_hash(p->at);
 869         if (start_hash)
 870                 *start_hash = bhash;
 871         if ((hash & 1) == 0) {
 872                 if ((bhash & ~1) != hash)
 873                         return 0;
 874         }
 875         /*
 876          * If the hash is HASH_NB_ALWAYS, we always go to the next
 877          * block so no check is necessary
 878          */
 879         while (num_frames--) {
 880                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 881                 if (IS_ERR(bh))
 882                         return PTR_ERR(bh);
 883                 p++;
 884                 brelse(p->bh);
 885                 p->bh = bh;
 886                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 887         }
 888         return 1;
 889 }
 890
 891
 892 /*
 893  * This function fills a red-black tree with information from a
 894  * directory block.  It returns the number directory entries loaded
 895  * into the tree.  If there is an error it is returned in err.
 896  */
 897 static int htree_dirblock_to_tree(struct file *dir_file,
 898                                   struct inode *dir, ext4_lblk_t block,
 899                                   struct dx_hash_info *hinfo,
 900                                   __u32 start_hash, __u32 start_minor_hash)
 901 {
 902         struct buffer_head *bh;
 903         struct ext4_dir_entry_2 *de, *top;
 904         int err = 0, count = 0;
 905
 906         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 907                                                         (unsigned long)block));
 908         bh = ext4_read_dirblock(dir, block, DIRENT);
 909         if (IS_ERR(bh))
 910                 return PTR_ERR(bh);
 911
 912         de = (struct ext4_dir_entry_2 *) bh->b_data;
 913         top = (struct ext4_dir_entry_2 *) ((char *) de +
 914                                            dir->i_sb->s_blocksize -
 915                                            EXT4_DIR_REC_LEN(0));
 916         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 917                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 918                                 bh->b_data, bh->b_size,
 919                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 920                                          + ((char *)de - bh->b_data))) {
 921                         /* silently ignore the rest of the block */
 922                         break;
 923                 }
 924                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 925                 if ((hinfo->hash < start_hash) ||
 926                     ((hinfo->hash == start_hash) &&
 927                      (hinfo->minor_hash < start_minor_hash)))
 928                         continue;
 929                 if (de->inode == 0)
 930                         continue;
 931                 if ((err = ext4_htree_store_dirent(dir_file,
 932                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
 933                         brelse(bh);
 934                         return err;
 935                 }
 936                 count++;
 937         }
 938         brelse(bh);
 939         return count;
 940 }
 941
 942
 943 /*
 944  * This function fills a red-black tree with information from a
 945  * directory.  We start scanning the directory in hash order, starting
 946  * at start_hash and start_minor_hash.
 947  *
 948  * This function returns the number of entries inserted into the tree,
 949  * or a negative error code.
 950  */
 951 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 952                          __u32 start_minor_hash, __u32 *next_hash)
 953 {
 954         struct dx_hash_info hinfo;
 955         struct ext4_dir_entry_2 *de;
 956         struct dx_frame frames[2], *frame;
 957         struct inode *dir;
 958         ext4_lblk_t block;
 959         int count = 0;
 960         int ret, err;
 961         __u32 hashval;
 962
 963         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 964                        start_hash, start_minor_hash));
 965         dir = file_inode(dir_file);
 966         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
 967                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 968                 if (hinfo.hash_version <= DX_HASH_TEA)
 969                         hinfo.hash_version +=
 970                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
 971                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 972                 if (ext4_has_inline_data(dir)) {
 973                         int has_inline_data = 1;
 974                         count = htree_inlinedir_to_tree(dir_file, dir, 0,
 975                                                         &hinfo, start_hash,
 976                                                         start_minor_hash,
 977                                                         &has_inline_data);
 978                         if (has_inline_data) {
 979                                 *next_hash = ~0;
 980                                 return count;
 981                         }
 982                 }
 983                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
 984                                                start_hash, start_minor_hash);
 985                 *next_hash = ~0;
 986                 return count;
 987         }
 988         hinfo.hash = start_hash;
 989         hinfo.minor_hash = 0;
 990         frame = dx_probe(NULL, dir, &hinfo, frames, &err);
 991         if (!frame)
 992                 return err;
 993
 994         /* Add '.' and '..' from the htree header */
 995         if (!start_hash && !start_minor_hash) {
 996                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 997                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 998                         goto errout;
 999                 count++;
1000         }
1001         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1002                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1003                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1004                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
1005                         goto errout;
1006                 count++;
1007         }
1008
1009         while (1) {
1010                 block = dx_get_block(frame->at);
1011                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1012                                              start_hash, start_minor_hash);
1013                 if (ret < 0) {
1014                         err = ret;
1015                         goto errout;
1016                 }
1017                 count += ret;
1018                 hashval = ~0;
1019                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1020                                             frame, frames, &hashval);
1021                 *next_hash = hashval;
1022                 if (ret < 0) {
1023                         err = ret;
1024                         goto errout;
1025                 }
1026                 /*
1027                  * Stop if:  (a) there are no more entries, or
1028                  * (b) we have inserted at least one entry and the
1029                  * next hash value is not a continuation
1030                  */
1031                 if ((ret == 0) ||
1032                     (count && ((hashval & 1) == 0)))
1033                         break;
1034         }
1035         dx_release(frames);
1036         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1037                        "next hash: %x\n", count, *next_hash));
1038         return count;
1039 errout:
1040         dx_release(frames);
1041         return (err);
1042 }
1043
1044 static inline int search_dirblock(struct buffer_head *bh,
1045                                   struct inode *dir,
1046                                   const struct qstr *d_name,
1047                                   unsigned int offset,
1048                                   struct ext4_dir_entry_2 **res_dir)
1049 {
1050         return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1051                           d_name, offset, res_dir);
1052 }
1053
1054 /*
1055  * Directory block splitting, compacting
1056  */
1057
1058 /*
1059  * Create map of hash values, offsets, and sizes, stored at end of block.
1060  * Returns number of entries mapped.
1061  */
1062 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
1063                        struct dx_hash_info *hinfo,
1064                        struct dx_map_entry *map_tail)
1065 {
1066         int count = 0;
1067         char *base = (char *) de;
1068         struct dx_hash_info h = *hinfo;
1069
1070         while ((char *) de < base + blocksize) {
1071                 if (de->name_len && de->inode) {
1072                         ext4fs_dirhash(de->name, de->name_len, &h);
1073                         map_tail--;
1074                         map_tail->hash = h.hash;
1075                         map_tail->offs = ((char *) de - base)>>2;
1076                         map_tail->size = le16_to_cpu(de->rec_len);
1077                         count++;
1078                         cond_resched();
1079                 }
1080                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1081                 de = ext4_next_entry(de, blocksize);
1082         }
1083         return count;
1084 }
1085
1086 /* Sort map by hash value */
1087 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1088 {
1089         struct dx_map_entry *p, *q, *top = map + count - 1;
1090         int more;
1091         /* Combsort until bubble sort doesn't suck */
1092         while (count > 2) {
1093                 count = count*10/13;
1094                 if (count - 9 < 2) /* 9, 10 -> 11 */
1095                         count = 11;
1096                 for (p = top, q = p - count; q >= map; p--, q--)
1097                         if (p->hash < q->hash)
1098                                 swap(*p, *q);
1099         }
1100         /* Garden variety bubble sort */
1101         do {
1102                 more = 0;
1103                 q = top;
1104                 while (q-- > map) {
1105                         if (q[1].hash >= q[0].hash)
1106                                 continue;
1107                         swap(*(q+1), *q);
1108                         more = 1;
1109                 }
1110         } while(more);
1111 }
1112
1113 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1114 {
1115         struct dx_entry *entries = frame->entries;
1116         struct dx_entry *old = frame->at, *new = old + 1;
1117         int count = dx_get_count(entries);
1118
1119         assert(count < dx_get_limit(entries));
1120         assert(old < entries + count);
1121         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1122         dx_set_hash(new, hash);
1123         dx_set_block(new, block);
1124         dx_set_count(entries, count + 1);
1125 }
1126
1127 /*
1128  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1129  *
1130  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1131  * `de != NULL' is guaranteed by caller.
1132  */
1133 static inline int ext4_match (int len, const char * const name,
1134                               struct ext4_dir_entry_2 * de)
1135 {
1136         if (len != de->name_len)
1137                 return 0;
1138         if (!de->inode)
1139                 return 0;
1140         return !memcmp(name, de->name, len);
1141 }
1142
1143 /*
1144  * Returns 0 if not found, -1 on failure, and 1 on success
1145  */
1146 int search_dir(struct buffer_head *bh,
1147                char *search_buf,
1148                int buf_size,
1149                struct inode *dir,
1150                const struct qstr *d_name,
1151                unsigned int offset,
1152                struct ext4_dir_entry_2 **res_dir)
1153 {
1154         struct ext4_dir_entry_2 * de;
1155         char * dlimit;
1156         int de_len;
1157         const char *name = d_name->name;
1158         int namelen = d_name->len;
1159
1160         de = (struct ext4_dir_entry_2 *)search_buf;
1161         dlimit = search_buf + buf_size;
1162         while ((char *) de < dlimit) {
1163                 /* this code is executed quadratically often */
1164                 /* do minimal checking `by hand' */
1165
1166                 if ((char *) de + namelen <= dlimit &&
1167                     ext4_match (namelen, name, de)) {
1168                         /* found a match - just to be sure, do a full check */
1169                         if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1170                                                  bh->b_size, offset))
1171                                 return -1;
1172                         *res_dir = de;
1173                         return 1;
1174                 }
1175                 /* prevent looping on a bad block */
1176                 de_len = ext4_rec_len_from_disk(de->rec_len,
1177                                                 dir->i_sb->s_blocksize);
1178                 if (de_len <= 0)
1179                         return -1;
1180                 offset += de_len;
1181                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1182         }
1183         return 0;
1184 }
1185
1186 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1187                                struct ext4_dir_entry *de)
1188 {
1189         struct super_block *sb = dir->i_sb;
1190
1191         if (!is_dx(dir))
1192                 return 0;
1193         if (block == 0)
1194                 return 1;
1195         if (de->inode == 0 &&
1196             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1197                         sb->s_blocksize)
1198                 return 1;
1199         return 0;
1200 }
1201
1202 /*
1203  *      ext4_find_entry()
1204  *
1205  * finds an entry in the specified directory with the wanted name. It
1206  * returns the cache buffer in which the entry was found, and the entry
1207  * itself (as a parameter - res_dir). It does NOT read the inode of the
1208  * entry - you'll have to do that yourself if you want to.
1209  *
1210  * The returned buffer_head has ->b_count elevated.  The caller is expected
1211  * to brelse() it when appropriate.
1212  */
1213 static struct buffer_head * ext4_find_entry (struct inode *dir,
1214                                         const struct qstr *d_name,
1215                                         struct ext4_dir_entry_2 **res_dir,
1216                                         int *inlined)
1217 {
1218         struct super_block *sb;
1219         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1220         struct buffer_head *bh, *ret = NULL;
1221         ext4_lblk_t start, block, b;
1222         const u8 *name = d_name->name;
1223         int ra_max = 0;         /* Number of bh's in the readahead
1224                                    buffer, bh_use[] */
1225         int ra_ptr = 0;         /* Current index into readahead
1226                                    buffer */
1227         int num = 0;
1228         ext4_lblk_t  nblocks;
1229         int i, err;
1230         int namelen;
1231
1232         *res_dir = NULL;
1233         sb = dir->i_sb;
1234         namelen = d_name->len;
1235         if (namelen > EXT4_NAME_LEN)
1236                 return NULL;
1237
1238         if (ext4_has_inline_data(dir)) {
1239                 int has_inline_data = 1;
1240                 ret = ext4_find_inline_entry(dir, d_name, res_dir,
1241                                              &has_inline_data);
1242                 if (has_inline_data) {
1243                         if (inlined)
1244                                 *inlined = 1;
1245                         return ret;
1246                 }
1247         }
1248
1249         if ((namelen <= 2) && (name[0] == '.') &&
1250             (name[1] == '.' || name[1] == '\0')) {
1251                 /*
1252                  * "." or ".." will only be in the first block
1253                  * NFS may look up ".."; "." should be handled by the VFS
1254                  */
1255                 block = start = 0;
1256                 nblocks = 1;
1257                 goto restart;
1258         }
1259         if (is_dx(dir)) {
1260                 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
1261                 /*
1262                  * On success, or if the error was file not found,
1263                  * return.  Otherwise, fall back to doing a search the
1264                  * old fashioned way.
1265                  */
1266                 if (bh || (err != ERR_BAD_DX_DIR))
1267                         return bh;
1268                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1269                                "falling back\n"));
1270         }
1271         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1272         start = EXT4_I(dir)->i_dir_start_lookup;
1273         if (start >= nblocks)
1274                 start = 0;
1275         block = start;
1276 restart:
1277         do {
1278                 /*
1279                  * We deal with the read-ahead logic here.
1280                  */
1281                 if (ra_ptr >= ra_max) {
1282                         /* Refill the readahead buffer */
1283                         ra_ptr = 0;
1284                         b = block;
1285                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1286                                 /*
1287                                  * Terminate if we reach the end of the
1288                                  * directory and must wrap, or if our
1289                                  * search has finished at this block.
1290                                  */
1291                                 if (b >= nblocks || (num && block == start)) {
1292                                         bh_use[ra_max] = NULL;
1293                                         break;
1294                                 }
1295                                 num++;
1296                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
1297                                 bh_use[ra_max] = bh;
1298                                 if (bh)
1299                                         ll_rw_block(READ | REQ_META | REQ_PRIO,
1300                                                     1, &bh);
1301                         }
1302                 }
1303                 if ((bh = bh_use[ra_ptr++]) == NULL)
1304                         goto next;
1305                 wait_on_buffer(bh);
1306                 if (!buffer_uptodate(bh)) {
1307                         /* read error, skip block & hope for the best */
1308                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1309                                          (unsigned long) block);
1310                         brelse(bh);
1311                         goto next;
1312                 }
1313                 if (!buffer_verified(bh) &&
1314                     !is_dx_internal_node(dir, block,
1315                                          (struct ext4_dir_entry *)bh->b_data) &&
1316                     !ext4_dirent_csum_verify(dir,
1317                                 (struct ext4_dir_entry *)bh->b_data)) {
1318                         EXT4_ERROR_INODE(dir, "checksumming directory "
1319                                          "block %lu", (unsigned long)block);
1320                         brelse(bh);
1321                         goto next;
1322                 }
1323                 set_buffer_verified(bh);
1324                 i = search_dirblock(bh, dir, d_name,
1325                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1326                 if (i == 1) {
1327                         EXT4_I(dir)->i_dir_start_lookup = block;
1328                         ret = bh;
1329                         goto cleanup_and_exit;
1330                 } else {
1331                         brelse(bh);
1332                         if (i < 0)
1333                                 goto cleanup_and_exit;
1334                 }
1335         next:
1336                 if (++block >= nblocks)
1337                         block = 0;
1338         } while (block != start);
1339
1340         /*
1341          * If the directory has grown while we were searching, then
1342          * search the last part of the directory before giving up.
1343          */
1344         block = nblocks;
1345         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1346         if (block < nblocks) {
1347                 start = 0;
1348                 goto restart;
1349         }
1350
1351 cleanup_and_exit:
1352         /* Clean up the read-ahead blocks */
1353         for (; ra_ptr < ra_max; ra_ptr++)
1354                 brelse(bh_use[ra_ptr]);
1355         return ret;
1356 }
1357
1358 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1359                        struct ext4_dir_entry_2 **res_dir, int *err)
1360 {
1361         struct super_block * sb = dir->i_sb;
1362         struct dx_hash_info     hinfo;
1363         struct dx_frame frames[2], *frame;
1364         struct buffer_head *bh;
1365         ext4_lblk_t block;
1366         int retval;
1367
1368         if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1369                 return NULL;
1370         do {
1371                 block = dx_get_block(frame->at);
1372                 bh = ext4_read_dirblock(dir, block, DIRENT);
1373                 if (IS_ERR(bh)) {
1374                         *err = PTR_ERR(bh);
1375                         goto errout;
1376                 }
1377                 retval = search_dirblock(bh, dir, d_name,
1378                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1379                                          res_dir);
1380                 if (retval == 1) {      /* Success! */
1381                         dx_release(frames);
1382                         return bh;
1383                 }
1384                 brelse(bh);
1385                 if (retval == -1) {
1386                         *err = ERR_BAD_DX_DIR;
1387                         goto errout;
1388                 }
1389
1390                 /* Check to see if we should continue to search */
1391                 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1392                                                frames, NULL);
1393                 if (retval < 0) {
1394                         ext4_warning(sb,
1395                              "error reading index page in directory #%lu",
1396                              dir->i_ino);
1397                         *err = retval;
1398                         goto errout;
1399                 }
1400         } while (retval == 1);
1401
1402         *err = -ENOENT;
1403 errout:
1404         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1405         dx_release (frames);
1406         return NULL;
1407 }
1408
1409 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1410 {
1411         struct inode *inode;
1412         struct ext4_dir_entry_2 *de;
1413         struct buffer_head *bh;
1414
1415         if (dentry->d_name.len > EXT4_NAME_LEN)
1416                 return ERR_PTR(-ENAMETOOLONG);
1417
1418         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1419         inode = NULL;
1420         if (bh) {
1421                 __u32 ino = le32_to_cpu(de->inode);
1422                 brelse(bh);
1423                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1424                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1425                         return ERR_PTR(-EIO);
1426                 }
1427                 if (unlikely(ino == dir->i_ino)) {
1428                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1429                                          dentry);
1430                         return ERR_PTR(-EIO);
1431                 }
1432                 inode = ext4_iget(dir->i_sb, ino);
1433                 if (inode == ERR_PTR(-ESTALE)) {
1434                         EXT4_ERROR_INODE(dir,
1435                                          "deleted inode referenced: %u",
1436                                          ino);
1437                         return ERR_PTR(-EIO);
1438                 }
1439         }
1440         return d_splice_alias(inode, dentry);
1441 }
1442
1443
1444 struct dentry *ext4_get_parent(struct dentry *child)
1445 {
1446         __u32 ino;
1447         static const struct qstr dotdot = QSTR_INIT("..", 2);
1448         struct ext4_dir_entry_2 * de;
1449         struct buffer_head *bh;
1450
1451         bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL);
1452         if (!bh)
1453                 return ERR_PTR(-ENOENT);
1454         ino = le32_to_cpu(de->inode);
1455         brelse(bh);
1456
1457         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1458                 EXT4_ERROR_INODE(child->d_inode,
1459                                  "bad parent inode number: %u", ino);
1460                 return ERR_PTR(-EIO);
1461         }
1462
1463         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1464 }
1465
1466 /*
1467  * Move count entries from end of map between two memory locations.
1468  * Returns pointer to last entry moved.
1469  */
1470 static struct ext4_dir_entry_2 *
1471 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1472                 unsigned blocksize)
1473 {
1474         unsigned rec_len = 0;
1475
1476         while (count--) {
1477                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1478                                                 (from + (map->offs<<2));
1479                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1480                 memcpy (to, de, rec_len);
1481                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1482                                 ext4_rec_len_to_disk(rec_len, blocksize);
1483                 de->inode = 0;
1484                 map++;
1485                 to += rec_len;
1486         }
1487         return (struct ext4_dir_entry_2 *) (to - rec_len);
1488 }
1489
1490 /*
1491  * Compact each dir entry in the range to the minimal rec_len.
1492  * Returns pointer to last entry in range.
1493  */
1494 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1495 {
1496         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1497         unsigned rec_len = 0;
1498
1499         prev = to = de;
1500         while ((char*)de < base + blocksize) {
1501                 next = ext4_next_entry(de, blocksize);
1502                 if (de->inode && de->name_len) {
1503                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1504                         if (de > to)
1505                                 memmove(to, de, rec_len);
1506                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1507                         prev = to;
1508                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1509                 }
1510                 de = next;
1511         }
1512         return prev;
1513 }
1514
1515 /*
1516  * Split a full leaf block to make room for a new dir entry.
1517  * Allocate a new block, and move entries so that they are approx. equally full.
1518  * Returns pointer to de in block into which the new entry will be inserted.
1519  */
1520 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1521                         struct buffer_head **bh,struct dx_frame *frame,
1522                         struct dx_hash_info *hinfo, int *error)
1523 {
1524         unsigned blocksize = dir->i_sb->s_blocksize;
1525         unsigned count, continued;
1526         struct buffer_head *bh2;
1527         ext4_lblk_t newblock;
1528         u32 hash2;
1529         struct dx_map_entry *map;
1530         char *data1 = (*bh)->b_data, *data2;
1531         unsigned split, move, size;
1532         struct ext4_dir_entry_2 *de = NULL, *de2;
1533         struct ext4_dir_entry_tail *t;
1534         int     csum_size = 0;
1535         int     err = 0, i;
1536
1537         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
1538                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1539                 csum_size = sizeof(struct ext4_dir_entry_tail);
1540
1541         bh2 = ext4_append(handle, dir, &newblock);
1542         if (IS_ERR(bh2)) {
1543                 brelse(*bh);
1544                 *bh = NULL;
1545                 *error = PTR_ERR(bh2);
1546                 return NULL;
1547         }
1548
1549         BUFFER_TRACE(*bh, "get_write_access");
1550         err = ext4_journal_get_write_access(handle, *bh);
1551         if (err)
1552                 goto journal_error;
1553
1554         BUFFER_TRACE(frame->bh, "get_write_access");
1555         err = ext4_journal_get_write_access(handle, frame->bh);
1556         if (err)
1557                 goto journal_error;
1558
1559         data2 = bh2->b_data;
1560
1561         /* create map in the end of data2 block */
1562         map = (struct dx_map_entry *) (data2 + blocksize);
1563         count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1564                              blocksize, hinfo, map);
1565         map -= count;
1566         dx_sort_map(map, count);
1567         /* Split the existing block in the middle, size-wise */
1568         size = 0;
1569         move = 0;
1570         for (i = count-1; i >= 0; i--) {
1571                 /* is more than half of this entry in 2nd half of the block? */
1572                 if (size + map[i].size/2 > blocksize/2)
1573                         break;
1574                 size += map[i].size;
1575                 move++;
1576         }
1577         /* map index at which we will split */
1578         split = count - move;
1579         hash2 = map[split].hash;
1580         continued = hash2 == map[split - 1].hash;
1581         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1582                         (unsigned long)dx_get_block(frame->at),
1583                                         hash2, split, count-split));
1584
1585         /* Fancy dance to stay within two buffers */
1586         de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1587         de = dx_pack_dirents(data1, blocksize);
1588         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1589                                            (char *) de,
1590                                            blocksize);
1591         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1592                                             (char *) de2,
1593                                             blocksize);
1594         if (csum_size) {
1595                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1596                 initialize_dirent_tail(t, blocksize);
1597
1598                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1599                 initialize_dirent_tail(t, blocksize);
1600         }
1601
1602         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1603         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1604
1605         /* Which block gets the new entry? */
1606         if (hinfo->hash >= hash2)
1607         {
1608                 swap(*bh, bh2);
1609                 de = de2;
1610         }
1611         dx_insert_block(frame, hash2 + continued, newblock);
1612         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1613         if (err)
1614                 goto journal_error;
1615         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1616         if (err)
1617                 goto journal_error;
1618         brelse(bh2);
1619         dxtrace(dx_show_index("frame", frame->entries));
1620         return de;
1621
1622 journal_error:
1623         brelse(*bh);
1624         brelse(bh2);
1625         *bh = NULL;
1626         ext4_std_error(dir->i_sb, err);
1627         *error = err;
1628         return NULL;
1629 }
1630
1631 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1632                       struct buffer_head *bh,
1633                       void *buf, int buf_size,
1634                       const char *name, int namelen,
1635                       struct ext4_dir_entry_2 **dest_de)
1636 {
1637         struct ext4_dir_entry_2 *de;
1638         unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
1639         int nlen, rlen;
1640         unsigned int offset = 0;
1641         char *top;
1642
1643         de = (struct ext4_dir_entry_2 *)buf;
1644         top = buf + buf_size - reclen;
1645         while ((char *) de <= top) {
1646                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1647                                          buf, buf_size, offset))
1648                         return -EIO;
1649                 if (ext4_match(namelen, name, de))
1650                         return -EEXIST;
1651                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1652                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1653                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1654                         break;
1655                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1656                 offset += rlen;
1657         }
1658         if ((char *) de > top)
1659                 return -ENOSPC;
1660
1661         *dest_de = de;
1662         return 0;
1663 }
1664
1665 void ext4_insert_dentry(struct inode *inode,
1666                         struct ext4_dir_entry_2 *de,
1667                         int buf_size,
1668                         const char *name, int namelen)
1669 {
1670
1671         int nlen, rlen;
1672
1673         nlen = EXT4_DIR_REC_LEN(de->name_len);
1674         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1675         if (de->inode) {
1676                 struct ext4_dir_entry_2 *de1 =
1677                                 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1678                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1679                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1680                 de = de1;
1681         }
1682         de->file_type = EXT4_FT_UNKNOWN;
1683         de->inode = cpu_to_le32(inode->i_ino);
1684         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1685         de->name_len = namelen;
1686         memcpy(de->name, name, namelen);
1687 }
1688 /*
1689  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1690  * it points to a directory entry which is guaranteed to be large
1691  * enough for new directory entry.  If de is NULL, then
1692  * add_dirent_to_buf will attempt search the directory block for
1693  * space.  It will return -ENOSPC if no space is available, and -EIO
1694  * and -EEXIST if directory entry already exists.
1695  */
1696 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1697                              struct inode *inode, struct ext4_dir_entry_2 *de,
1698                              struct buffer_head *bh)
1699 {
1700         struct inode    *dir = dentry->d_parent->d_inode;
1701         const char      *name = dentry->d_name.name;
1702         int             namelen = dentry->d_name.len;
1703         unsigned int    blocksize = dir->i_sb->s_blocksize;
1704         int             csum_size = 0;
1705         int             err;
1706
1707         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1708                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1709                 csum_size = sizeof(struct ext4_dir_entry_tail);
1710
1711         if (!de) {
1712                 err = ext4_find_dest_de(dir, inode,
1713                                         bh, bh->b_data, blocksize - csum_size,
1714                                         name, namelen, &de);
1715                 if (err)
1716                         return err;
1717         }
1718         BUFFER_TRACE(bh, "get_write_access");
1719         err = ext4_journal_get_write_access(handle, bh);
1720         if (err) {
1721                 ext4_std_error(dir->i_sb, err);
1722                 return err;
1723         }
1724
1725         /* By now the buffer is marked for journaling */
1726         ext4_insert_dentry(inode, de, blocksize, name, namelen);
1727
1728         /*
1729          * XXX shouldn't update any times until successful
1730          * completion of syscall, but too many callers depend
1731          * on this.
1732          *
1733          * XXX similarly, too many callers depend on
1734          * ext4_new_inode() setting the times, but error
1735          * recovery deletes the inode, so the worst that can
1736          * happen is that the times are slightly out of date
1737          * and/or different from the directory change time.
1738          */
1739         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1740         ext4_update_dx_flag(dir);
1741         dir->i_version++;
1742         ext4_mark_inode_dirty(handle, dir);
1743         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1744         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1745         if (err)
1746                 ext4_std_error(dir->i_sb, err);
1747         return 0;
1748 }
1749
1750 /*
1751  * This converts a one block unindexed directory to a 3 block indexed
1752  * directory, and adds the dentry to the indexed directory.
1753  */
1754 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1755                             struct inode *inode, struct buffer_head *bh)
1756 {
1757         struct inode    *dir = dentry->d_parent->d_inode;
1758         const char      *name = dentry->d_name.name;
1759         int             namelen = dentry->d_name.len;
1760         struct buffer_head *bh2;
1761         struct dx_root  *root;
1762         struct dx_frame frames[2], *frame;
1763         struct dx_entry *entries;
1764         struct ext4_dir_entry_2 *de, *de2;
1765         struct ext4_dir_entry_tail *t;
1766         char            *data1, *top;
1767         unsigned        len;
1768         int             retval;
1769         unsigned        blocksize;
1770         struct dx_hash_info hinfo;
1771         ext4_lblk_t  block;
1772         struct fake_dirent *fde;
1773         int             csum_size = 0;
1774
1775         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1776                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1777                 csum_size = sizeof(struct ext4_dir_entry_tail);
1778
1779         blocksize =  dir->i_sb->s_blocksize;
1780         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1781         retval = ext4_journal_get_write_access(handle, bh);
1782         if (retval) {
1783                 ext4_std_error(dir->i_sb, retval);
1784                 brelse(bh);
1785                 return retval;
1786         }
1787         root = (struct dx_root *) bh->b_data;
1788
1789         /* The 0th block becomes the root, move the dirents out */
1790         fde = &root->dotdot;
1791         de = (struct ext4_dir_entry_2 *)((char *)fde +
1792                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1793         if ((char *) de >= (((char *) root) + blocksize)) {
1794                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1795                 brelse(bh);
1796                 return -EIO;
1797         }
1798         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1799
1800         /* Allocate new block for the 0th block's dirents */
1801         bh2 = ext4_append(handle, dir, &block);
1802         if (IS_ERR(bh2)) {
1803                 brelse(bh);
1804                 return PTR_ERR(bh2);
1805         }
1806         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1807         data1 = bh2->b_data;
1808
1809         memcpy (data1, de, len);
1810         de = (struct ext4_dir_entry_2 *) data1;
1811         top = data1 + len;
1812         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1813                 de = de2;
1814         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1815                                            (char *) de,
1816                                            blocksize);
1817
1818         if (csum_size) {
1819                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1820                 initialize_dirent_tail(t, blocksize);
1821         }
1822
1823         /* Initialize the root; the dot dirents already exist */
1824         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1825         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1826                                            blocksize);
1827         memset (&root->info, 0, sizeof(root->info));
1828         root->info.info_length = sizeof(root->info);
1829         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1830         entries = root->entries;
1831         dx_set_block(entries, 1);
1832         dx_set_count(entries, 1);
1833         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1834
1835         /* Initialize as for dx_probe */
1836         hinfo.hash_version = root->info.hash_version;
1837         if (hinfo.hash_version <= DX_HASH_TEA)
1838                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1839         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1840         ext4fs_dirhash(name, namelen, &hinfo);
1841         frame = frames;
1842         frame->entries = entries;
1843         frame->at = entries;
1844         frame->bh = bh;
1845         bh = bh2;
1846
1847         ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1848         ext4_handle_dirty_dirent_node(handle, dir, bh);
1849
1850         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1851         if (!de) {
1852                 /*
1853                  * Even if the block split failed, we have to properly write
1854                  * out all the changes we did so far. Otherwise we can end up
1855                  * with corrupted filesystem.
1856                  */
1857                 ext4_mark_inode_dirty(handle, dir);
1858                 dx_release(frames);
1859                 return retval;
1860         }
1861         dx_release(frames);
1862
1863         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1864         brelse(bh);
1865         return retval;
1866 }
1867
1868 /*
1869  *      ext4_add_entry()
1870  *
1871  * adds a file entry to the specified directory, using the same
1872  * semantics as ext4_find_entry(). It returns NULL if it failed.
1873  *
1874  * NOTE!! The inode part of 'de' is left at 0 - which means you
1875  * may not sleep between calling this and putting something into
1876  * the entry, as someone else might have used it while you slept.
1877  */
1878 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1879                           struct inode *inode)
1880 {
1881         struct inode *dir = dentry->d_parent->d_inode;
1882         struct buffer_head *bh;
1883         struct ext4_dir_entry_2 *de;
1884         struct ext4_dir_entry_tail *t;
1885         struct super_block *sb;
1886         int     retval;
1887         int     dx_fallback=0;
1888         unsigned blocksize;
1889         ext4_lblk_t block, blocks;
1890         int     csum_size = 0;
1891
1892         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1893                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1894                 csum_size = sizeof(struct ext4_dir_entry_tail);
1895
1896         sb = dir->i_sb;
1897         blocksize = sb->s_blocksize;
1898         if (!dentry->d_name.len)
1899                 return -EINVAL;
1900
1901         if (ext4_has_inline_data(dir)) {
1902                 retval = ext4_try_add_inline_entry(handle, dentry, inode);
1903                 if (retval < 0)
1904                         return retval;
1905                 if (retval == 1) {
1906                         retval = 0;
1907                         return retval;
1908                 }
1909         }
1910
1911         if (is_dx(dir)) {
1912                 retval = ext4_dx_add_entry(handle, dentry, inode);
1913                 if (!retval || (retval != ERR_BAD_DX_DIR))
1914                         return retval;
1915                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1916                 dx_fallback++;
1917                 ext4_mark_inode_dirty(handle, dir);
1918         }
1919         blocks = dir->i_size >> sb->s_blocksize_bits;
1920         for (block = 0; block < blocks; block++) {
1921                 bh = ext4_read_dirblock(dir, block, DIRENT);
1922                 if (IS_ERR(bh))
1923                         return PTR_ERR(bh);
1924
1925                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1926                 if (retval != -ENOSPC) {
1927                         brelse(bh);
1928                         return retval;
1929                 }
1930
1931                 if (blocks == 1 && !dx_fallback &&
1932                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1933                         return make_indexed_dir(handle, dentry, inode, bh);
1934                 brelse(bh);
1935         }
1936         bh = ext4_append(handle, dir, &block);
1937         if (IS_ERR(bh))
1938                 return PTR_ERR(bh);
1939         de = (struct ext4_dir_entry_2 *) bh->b_data;
1940         de->inode = 0;
1941         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
1942
1943         if (csum_size) {
1944                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
1945                 initialize_dirent_tail(t, blocksize);
1946         }
1947
1948         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1949         brelse(bh);
1950         if (retval == 0)
1951                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1952         return retval;
1953 }
1954
1955 /*
1956  * Returns 0 for success, or a negative error value
1957  */
1958 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1959                              struct inode *inode)
1960 {
1961         struct dx_frame frames[2], *frame;
1962         struct dx_entry *entries, *at;
1963         struct dx_hash_info hinfo;
1964         struct buffer_head *bh;
1965         struct inode *dir = dentry->d_parent->d_inode;
1966         struct super_block *sb = dir->i_sb;
1967         struct ext4_dir_entry_2 *de;
1968         int err;
1969
1970         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1971         if (!frame)
1972                 return err;
1973         entries = frame->entries;
1974         at = frame->at;
1975         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
1976         if (IS_ERR(bh)) {
1977                 err = PTR_ERR(bh);
1978                 bh = NULL;
1979                 goto cleanup;
1980         }
1981
1982         BUFFER_TRACE(bh, "get_write_access");
1983         err = ext4_journal_get_write_access(handle, bh);
1984         if (err)
1985                 goto journal_error;
1986
1987         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1988         if (err != -ENOSPC)
1989                 goto cleanup;
1990
1991         /* Block full, should compress but for now just split */
1992         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1993                        dx_get_count(entries), dx_get_limit(entries)));
1994         /* Need to split index? */
1995         if (dx_get_count(entries) == dx_get_limit(entries)) {
1996                 ext4_lblk_t newblock;
1997                 unsigned icount = dx_get_count(entries);
1998                 int levels = frame - frames;
1999                 struct dx_entry *entries2;
2000                 struct dx_node *node2;
2001                 struct buffer_head *bh2;
2002
2003                 if (levels && (dx_get_count(frames->entries) ==
2004                                dx_get_limit(frames->entries))) {
2005                         ext4_warning(sb, "Directory index full!");
2006                         err = -ENOSPC;
2007                         goto cleanup;
2008                 }
2009                 bh2 = ext4_append(handle, dir, &newblock);
2010                 if (IS_ERR(bh2)) {
2011                         err = PTR_ERR(bh2);
2012                         goto cleanup;
2013                 }
2014                 node2 = (struct dx_node *)(bh2->b_data);
2015                 entries2 = node2->entries;
2016                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2017                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2018                                                            sb->s_blocksize);
2019                 BUFFER_TRACE(frame->bh, "get_write_access");
2020                 err = ext4_journal_get_write_access(handle, frame->bh);
2021                 if (err)
2022                         goto journal_error;
2023                 if (levels) {
2024                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2025                         unsigned hash2 = dx_get_hash(entries + icount1);
2026                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2027                                        icount1, icount2));
2028
2029                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2030                         err = ext4_journal_get_write_access(handle,
2031                                                              frames[0].bh);
2032                         if (err)
2033                                 goto journal_error;
2034
2035                         memcpy((char *) entries2, (char *) (entries + icount1),
2036                                icount2 * sizeof(struct dx_entry));
2037                         dx_set_count(entries, icount1);
2038                         dx_set_count(entries2, icount2);
2039                         dx_set_limit(entries2, dx_node_limit(dir));
2040
2041                         /* Which index block gets the new entry? */
2042                         if (at - entries >= icount1) {
2043                                 frame->at = at = at - entries - icount1 + entries2;
2044                                 frame->entries = entries = entries2;
2045                                 swap(frame->bh, bh2);
2046                         }
2047                         dx_insert_block(frames + 0, hash2, newblock);
2048                         dxtrace(dx_show_index("node", frames[1].entries));
2049                         dxtrace(dx_show_index("node",
2050                                ((struct dx_node *) bh2->b_data)->entries));
2051                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2052                         if (err)
2053                                 goto journal_error;
2054                         brelse (bh2);
2055                 } else {
2056                         dxtrace(printk(KERN_DEBUG
2057                                        "Creating second level index...\n"));
2058                         memcpy((char *) entries2, (char *) entries,
2059                                icount * sizeof(struct dx_entry));
2060                         dx_set_limit(entries2, dx_node_limit(dir));
2061
2062                         /* Set up root */
2063                         dx_set_count(entries, 1);
2064                         dx_set_block(entries + 0, newblock);
2065                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2066
2067                         /* Add new access path frame */
2068                         frame = frames + 1;
2069                         frame->at = at = at - entries + entries2;
2070                         frame->entries = entries = entries2;
2071                         frame->bh = bh2;
2072                         err = ext4_journal_get_write_access(handle,
2073                                                              frame->bh);
2074                         if (err)
2075                                 goto journal_error;
2076                 }
2077                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2078                 if (err) {
2079                         ext4_std_error(inode->i_sb, err);
2080                         goto cleanup;
2081                 }
2082         }
2083         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
2084         if (!de)
2085                 goto cleanup;
2086         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2087         goto cleanup;
2088
2089 journal_error:
2090         ext4_std_error(dir->i_sb, err);
2091 cleanup:
2092         brelse(bh);
2093         dx_release(frames);
2094         return err;
2095 }
2096
2097 /*
2098  * ext4_generic_delete_entry deletes a directory entry by merging it
2099  * with the previous entry
2100  */
2101 int ext4_generic_delete_entry(handle_t *handle,
2102                               struct inode *dir,
2103                               struct ext4_dir_entry_2 *de_del,
2104                               struct buffer_head *bh,
2105                               void *entry_buf,
2106                               int buf_size,
2107                               int csum_size)
2108 {
2109         struct ext4_dir_entry_2 *de, *pde;
2110         unsigned int blocksize = dir->i_sb->s_blocksize;
2111         int i;
2112
2113         i = 0;
2114         pde = NULL;
2115         de = (struct ext4_dir_entry_2 *)entry_buf;
2116         while (i < buf_size - csum_size) {
2117                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2118                                          bh->b_data, bh->b_size, i))
2119                         return -EIO;
2120                 if (de == de_del)  {
2121                         if (pde)
2122                                 pde->rec_len = ext4_rec_len_to_disk(
2123                                         ext4_rec_len_from_disk(pde->rec_len,
2124                                                                blocksize) +
2125                                         ext4_rec_len_from_disk(de->rec_len,
2126                                                                blocksize),
2127                                         blocksize);
2128                         else
2129                                 de->inode = 0;
2130                         dir->i_version++;
2131                         return 0;
2132                 }
2133                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2134                 pde = de;
2135                 de = ext4_next_entry(de, blocksize);
2136         }
2137         return -ENOENT;
2138 }
2139
2140 static int ext4_delete_entry(handle_t *handle,
2141                              struct inode *dir,
2142                              struct ext4_dir_entry_2 *de_del,
2143                              struct buffer_head *bh)
2144 {
2145         int err, csum_size = 0;
2146
2147         if (ext4_has_inline_data(dir)) {
2148                 int has_inline_data = 1;
2149                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2150                                                &has_inline_data);
2151                 if (has_inline_data)
2152                         return err;
2153         }
2154
2155         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2156                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2157                 csum_size = sizeof(struct ext4_dir_entry_tail);
2158
2159         BUFFER_TRACE(bh, "get_write_access");
2160         err = ext4_journal_get_write_access(handle, bh);
2161         if (unlikely(err))
2162                 goto out;
2163
2164         err = ext4_generic_delete_entry(handle, dir, de_del,
2165                                         bh, bh->b_data,
2166                                         dir->i_sb->s_blocksize, csum_size);
2167         if (err)
2168                 goto out;
2169
2170         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2171         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2172         if (unlikely(err))
2173                 goto out;
2174
2175         return 0;
2176 out:
2177         if (err != -ENOENT)
2178                 ext4_std_error(dir->i_sb, err);
2179         return err;
2180 }
2181
2182 /*
2183  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2184  * since this indicates that nlinks count was previously 1.
2185  */
2186 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2187 {
2188         inc_nlink(inode);
2189         if (is_dx(inode) && inode->i_nlink > 1) {
2190                 /* limit is 16-bit i_links_count */
2191                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2192                         set_nlink(inode, 1);
2193                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2194                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2195                 }
2196         }
2197 }
2198
2199 /*
2200  * If a directory had nlink == 1, then we should let it be 1. This indicates
2201  * directory has >EXT4_LINK_MAX subdirs.
2202  */
2203 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2204 {
2205         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2206                 drop_nlink(inode);
2207 }
2208
2209
2210 static int ext4_add_nondir(handle_t *handle,
2211                 struct dentry *dentry, struct inode *inode)
2212 {
2213         int err = ext4_add_entry(handle, dentry, inode);
2214         if (!err) {
2215                 ext4_mark_inode_dirty(handle, inode);
2216                 unlock_new_inode(inode);
2217                 d_instantiate(dentry, inode);
2218                 return 0;
2219         }
2220         drop_nlink(inode);
2221         unlock_new_inode(inode);
2222         iput(inode);
2223         return err;
2224 }
2225
2226 /*
2227  * By the time this is called, we already have created
2228  * the directory cache entry for the new file, but it
2229  * is so far negative - it has no inode.
2230  *
2231  * If the create succeeds, we fill in the inode information
2232  * with d_instantiate().
2233  */
2234 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2235                        bool excl)
2236 {
2237         handle_t *handle;
2238         struct inode *inode;
2239         int err, credits, retries = 0;
2240
2241         dquot_initialize(dir);
2242
2243         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2244                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2245 retry:
2246         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2247                                             NULL, EXT4_HT_DIR, credits);
2248         handle = ext4_journal_current_handle();
2249         err = PTR_ERR(inode);
2250         if (!IS_ERR(inode)) {
2251                 inode->i_op = &ext4_file_inode_operations;
2252                 inode->i_fop = &ext4_file_operations;
2253                 ext4_set_aops(inode);
2254                 err = ext4_add_nondir(handle, dentry, inode);
2255                 if (!err && IS_DIRSYNC(dir))
2256                         ext4_handle_sync(handle);
2257         }
2258         if (handle)
2259                 ext4_journal_stop(handle);
2260         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2261                 goto retry;
2262         return err;
2263 }
2264
2265 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2266                       umode_t mode, dev_t rdev)
2267 {
2268         handle_t *handle;
2269         struct inode *inode;
2270         int err, credits, retries = 0;
2271
2272         if (!new_valid_dev(rdev))
2273                 return -EINVAL;
2274
2275         dquot_initialize(dir);
2276
2277         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2278                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2279 retry:
2280         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2281                                             NULL, EXT4_HT_DIR, credits);
2282         handle = ext4_journal_current_handle();
2283         err = PTR_ERR(inode);
2284         if (!IS_ERR(inode)) {
2285                 init_special_inode(inode, inode->i_mode, rdev);
2286                 inode->i_op = &ext4_special_inode_operations;
2287                 err = ext4_add_nondir(handle, dentry, inode);
2288                 if (!err && IS_DIRSYNC(dir))
2289                         ext4_handle_sync(handle);
2290         }
2291         if (handle)
2292                 ext4_journal_stop(handle);
2293         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2294                 goto retry;
2295         return err;
2296 }
2297
2298 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2299 {
2300         handle_t *handle;
2301         struct inode *inode;
2302         int err, retries = 0;
2303
2304         dquot_initialize(dir);
2305
2306 retry:
2307         inode = ext4_new_inode_start_handle(dir, mode,
2308                                             NULL, 0, NULL,
2309                                             EXT4_HT_DIR,
2310                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2311                           4 + EXT4_XATTR_TRANS_BLOCKS);
2312         handle = ext4_journal_current_handle();
2313         err = PTR_ERR(inode);
2314         if (!IS_ERR(inode)) {
2315                 inode->i_op = &ext4_file_inode_operations;
2316                 inode->i_fop = &ext4_file_operations;
2317                 ext4_set_aops(inode);
2318                 d_tmpfile(dentry, inode);
2319                 err = ext4_orphan_add(handle, inode);
2320                 if (err)
2321                         goto err_unlock_inode;
2322                 mark_inode_dirty(inode);
2323                 unlock_new_inode(inode);
2324         }
2325         if (handle)
2326                 ext4_journal_stop(handle);
2327         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2328                 goto retry;
2329         return err;
2330 err_unlock_inode:
2331         ext4_journal_stop(handle);
2332         unlock_new_inode(inode);
2333         return err;
2334 }
2335
2336 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2337                           struct ext4_dir_entry_2 *de,
2338                           int blocksize, int csum_size,
2339                           unsigned int parent_ino, int dotdot_real_len)
2340 {
2341         de->inode = cpu_to_le32(inode->i_ino);
2342         de->name_len = 1;
2343         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2344                                            blocksize);
2345         strcpy(de->name, ".");
2346         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2347
2348         de = ext4_next_entry(de, blocksize);
2349         de->inode = cpu_to_le32(parent_ino);
2350         de->name_len = 2;
2351         if (!dotdot_real_len)
2352                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2353                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2354                                         blocksize);
2355         else
2356                 de->rec_len = ext4_rec_len_to_disk(
2357                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2358         strcpy(de->name, "..");
2359         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2360
2361         return ext4_next_entry(de, blocksize);
2362 }
2363
2364 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2365                              struct inode *inode)
2366 {
2367         struct buffer_head *dir_block = NULL;
2368         struct ext4_dir_entry_2 *de;
2369         struct ext4_dir_entry_tail *t;
2370         ext4_lblk_t block = 0;
2371         unsigned int blocksize = dir->i_sb->s_blocksize;
2372         int csum_size = 0;
2373         int err;
2374
2375         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2376                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2377                 csum_size = sizeof(struct ext4_dir_entry_tail);
2378
2379         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2380                 err = ext4_try_create_inline_dir(handle, dir, inode);
2381                 if (err < 0 && err != -ENOSPC)
2382                         goto out;
2383                 if (!err)
2384                         goto out;
2385         }
2386
2387         inode->i_size = 0;
2388         dir_block = ext4_append(handle, inode, &block);
2389         if (IS_ERR(dir_block))
2390                 return PTR_ERR(dir_block);
2391         BUFFER_TRACE(dir_block, "get_write_access");
2392         err = ext4_journal_get_write_access(handle, dir_block);
2393         if (err)
2394                 goto out;
2395         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2396         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2397         set_nlink(inode, 2);
2398         if (csum_size) {
2399                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2400                 initialize_dirent_tail(t, blocksize);
2401         }
2402
2403         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2404         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2405         if (err)
2406                 goto out;
2407         set_buffer_verified(dir_block);
2408 out:
2409         brelse(dir_block);
2410         return err;
2411 }
2412
2413 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2414 {
2415         handle_t *handle;
2416         struct inode *inode;
2417         int err, credits, retries = 0;
2418
2419         if (EXT4_DIR_LINK_MAX(dir))
2420                 return -EMLINK;
2421
2422         dquot_initialize(dir);
2423
2424         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2425                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2426 retry:
2427         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2428                                             &dentry->d_name,
2429                                             0, NULL, EXT4_HT_DIR, credits);
2430         handle = ext4_journal_current_handle();
2431         err = PTR_ERR(inode);
2432         if (IS_ERR(inode))
2433                 goto out_stop;
2434
2435         inode->i_op = &ext4_dir_inode_operations;
2436         inode->i_fop = &ext4_dir_operations;
2437         err = ext4_init_new_dir(handle, dir, inode);
2438         if (err)
2439                 goto out_clear_inode;
2440         err = ext4_mark_inode_dirty(handle, inode);
2441         if (!err)
2442                 err = ext4_add_entry(handle, dentry, inode);
2443         if (err) {
2444 out_clear_inode:
2445                 clear_nlink(inode);
2446                 unlock_new_inode(inode);
2447                 ext4_mark_inode_dirty(handle, inode);
2448                 iput(inode);
2449                 goto out_stop;
2450         }
2451         ext4_inc_count(handle, dir);
2452         ext4_update_dx_flag(dir);
2453         err = ext4_mark_inode_dirty(handle, dir);
2454         if (err)
2455                 goto out_clear_inode;
2456         unlock_new_inode(inode);
2457         d_instantiate(dentry, inode);
2458         if (IS_DIRSYNC(dir))
2459                 ext4_handle_sync(handle);
2460
2461 out_stop:
2462         if (handle)
2463                 ext4_journal_stop(handle);
2464         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2465                 goto retry;
2466         return err;
2467 }
2468
2469 /*
2470  * routine to check that the specified directory is empty (for rmdir)
2471  */
2472 static int empty_dir(struct inode *inode)
2473 {
2474         unsigned int offset;
2475         struct buffer_head *bh;
2476         struct ext4_dir_entry_2 *de, *de1;
2477         struct super_block *sb;
2478         int err = 0;
2479
2480         if (ext4_has_inline_data(inode)) {
2481                 int has_inline_data = 1;
2482
2483                 err = empty_inline_dir(inode, &has_inline_data);
2484                 if (has_inline_data)
2485                         return err;
2486         }
2487
2488         sb = inode->i_sb;
2489         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2490                 EXT4_ERROR_INODE(inode, "invalid size");
2491                 return 1;
2492         }
2493         bh = ext4_read_dirblock(inode, 0, EITHER);
2494         if (IS_ERR(bh))
2495                 return 1;
2496
2497         de = (struct ext4_dir_entry_2 *) bh->b_data;
2498         de1 = ext4_next_entry(de, sb->s_blocksize);
2499         if (le32_to_cpu(de->inode) != inode->i_ino ||
2500                         !le32_to_cpu(de1->inode) ||
2501                         strcmp(".", de->name) ||
2502                         strcmp("..", de1->name)) {
2503                 ext4_warning(inode->i_sb,
2504                              "bad directory (dir #%lu) - no `.' or `..'",
2505                              inode->i_ino);
2506                 brelse(bh);
2507                 return 1;
2508         }
2509         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2510                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2511         de = ext4_next_entry(de1, sb->s_blocksize);
2512         while (offset < inode->i_size) {
2513                 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2514                         unsigned int lblock;
2515                         err = 0;
2516                         brelse(bh);
2517                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2518                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2519                         if (IS_ERR(bh))
2520                                 return 1;
2521                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2522                 }
2523                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2524                                          bh->b_data, bh->b_size, offset)) {
2525                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2526                                                          sb->s_blocksize);
2527                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2528                         continue;
2529                 }
2530                 if (le32_to_cpu(de->inode)) {
2531                         brelse(bh);
2532                         return 0;
2533                 }
2534                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2535                 de = ext4_next_entry(de, sb->s_blocksize);
2536         }
2537         brelse(bh);
2538         return 1;
2539 }
2540
2541 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
2542  * such inodes, starting at the superblock, in case we crash before the
2543  * file is closed/deleted, or in case the inode truncate spans multiple
2544  * transactions and the last transaction is not recovered after a crash.
2545  *
2546  * At filesystem recovery time, we walk this list deleting unlinked
2547  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2548  */
2549 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2550 {
2551         struct super_block *sb = inode->i_sb;
2552         struct ext4_iloc iloc;
2553         int err = 0, rc;
2554
2555         if (!EXT4_SB(sb)->s_journal)
2556                 return 0;
2557
2558         mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2559         if (!list_empty(&EXT4_I(inode)->i_orphan))
2560                 goto out_unlock;
2561
2562         /*
2563          * Orphan handling is only valid for files with data blocks
2564          * being truncated, or files being unlinked. Note that we either
2565          * hold i_mutex, or the inode can not be referenced from outside,
2566          * so i_nlink should not be bumped due to race
2567          */
2568         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2569                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2570
2571         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2572         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2573         if (err)
2574                 goto out_unlock;
2575
2576         err = ext4_reserve_inode_write(handle, inode, &iloc);
2577         if (err)
2578                 goto out_unlock;
2579         /*
2580          * Due to previous errors inode may be already a part of on-disk
2581          * orphan list. If so skip on-disk list modification.
2582          */
2583         if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2584                 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2585                         goto mem_insert;
2586
2587         /* Insert this inode at the head of the on-disk orphan list... */
2588         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2589         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2590         err = ext4_handle_dirty_super(handle, sb);
2591         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2592         if (!err)
2593                 err = rc;
2594
2595         /* Only add to the head of the in-memory list if all the
2596          * previous operations succeeded.  If the orphan_add is going to
2597          * fail (possibly taking the journal offline), we can't risk
2598          * leaving the inode on the orphan list: stray orphan-list
2599          * entries can cause panics at unmount time.
2600          *
2601          * This is safe: on error we're going to ignore the orphan list
2602          * anyway on the next recovery. */
2603 mem_insert:
2604         if (!err)
2605                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2606
2607         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2608         jbd_debug(4, "orphan inode %lu will point to %d\n",
2609                         inode->i_ino, NEXT_ORPHAN(inode));
2610 out_unlock:
2611         mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2612         ext4_std_error(inode->i_sb, err);
2613         return err;
2614 }
2615
2616 /*
2617  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2618  * of such inodes stored on disk, because it is finally being cleaned up.
2619  */
2620 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2621 {
2622         struct list_head *prev;
2623         struct ext4_inode_info *ei = EXT4_I(inode);
2624         struct ext4_sb_info *sbi;
2625         __u32 ino_next;
2626         struct ext4_iloc iloc;
2627         int err = 0;
2628
2629         if ((!EXT4_SB(inode->i_sb)->s_journal) &&
2630             !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS))
2631                 return 0;
2632
2633         mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2634         if (list_empty(&ei->i_orphan))
2635                 goto out;
2636
2637         ino_next = NEXT_ORPHAN(inode);
2638         prev = ei->i_orphan.prev;
2639         sbi = EXT4_SB(inode->i_sb);
2640
2641         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2642
2643         list_del_init(&ei->i_orphan);
2644
2645         /* If we're on an error path, we may not have a valid
2646          * transaction handle with which to update the orphan list on
2647          * disk, but we still need to remove the inode from the linked
2648          * list in memory. */
2649         if (!handle)
2650                 goto out;
2651
2652         err = ext4_reserve_inode_write(handle, inode, &iloc);
2653         if (err)
2654                 goto out_err;
2655
2656         if (prev == &sbi->s_orphan) {
2657                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2658                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2659                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2660                 if (err)
2661                         goto out_brelse;
2662                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2663                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2664         } else {
2665                 struct ext4_iloc iloc2;
2666                 struct inode *i_prev =
2667                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2668
2669                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2670                           i_prev->i_ino, ino_next);
2671                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2672                 if (err)
2673                         goto out_brelse;
2674                 NEXT_ORPHAN(i_prev) = ino_next;
2675                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2676         }
2677         if (err)
2678                 goto out_brelse;
2679         NEXT_ORPHAN(inode) = 0;
2680         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2681
2682 out_err:
2683         ext4_std_error(inode->i_sb, err);
2684 out:
2685         mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2686         return err;
2687
2688 out_brelse:
2689         brelse(iloc.bh);
2690         goto out_err;
2691 }
2692
2693 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2694 {
2695         int retval;
2696         struct inode *inode;
2697         struct buffer_head *bh;
2698         struct ext4_dir_entry_2 *de;
2699         handle_t *handle = NULL;
2700
2701         /* Initialize quotas before so that eventual writes go in
2702          * separate transaction */
2703         dquot_initialize(dir);
2704         dquot_initialize(dentry->d_inode);
2705
2706         retval = -ENOENT;
2707         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2708         if (!bh)
2709                 goto end_rmdir;
2710
2711         inode = dentry->d_inode;
2712
2713         retval = -EIO;
2714         if (le32_to_cpu(de->inode) != inode->i_ino)
2715                 goto end_rmdir;
2716
2717         retval = -ENOTEMPTY;
2718         if (!empty_dir(inode))
2719                 goto end_rmdir;
2720
2721         handle = ext4_journal_start(dir, EXT4_HT_DIR,
2722                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2723         if (IS_ERR(handle)) {
2724                 retval = PTR_ERR(handle);
2725                 handle = NULL;
2726                 goto end_rmdir;
2727         }
2728
2729         if (IS_DIRSYNC(dir))
2730                 ext4_handle_sync(handle);
2731
2732         retval = ext4_delete_entry(handle, dir, de, bh);
2733         if (retval)
2734                 goto end_rmdir;
2735         if (!EXT4_DIR_LINK_EMPTY(inode))
2736                 ext4_warning(inode->i_sb,
2737                              "empty directory has too many links (%d)",
2738                              inode->i_nlink);
2739         inode->i_version++;
2740         clear_nlink(inode);
2741         /* There's no need to set i_disksize: the fact that i_nlink is
2742          * zero will ensure that the right thing happens during any
2743          * recovery. */
2744         inode->i_size = 0;
2745         ext4_orphan_add(handle, inode);
2746         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2747         ext4_mark_inode_dirty(handle, inode);
2748         ext4_dec_count(handle, dir);
2749         ext4_update_dx_flag(dir);
2750         ext4_mark_inode_dirty(handle, dir);
2751
2752 end_rmdir:
2753         brelse(bh);
2754         if (handle)
2755                 ext4_journal_stop(handle);
2756         return retval;
2757 }
2758
2759 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2760 {
2761         int retval;
2762         struct inode *inode;
2763         struct buffer_head *bh;
2764         struct ext4_dir_entry_2 *de;
2765         handle_t *handle = NULL;
2766
2767         trace_ext4_unlink_enter(dir, dentry);
2768         /* Initialize quotas before so that eventual writes go
2769          * in separate transaction */
2770         dquot_initialize(dir);
2771         dquot_initialize(dentry->d_inode);
2772
2773         retval = -ENOENT;
2774         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2775         if (!bh)
2776                 goto end_unlink;
2777
2778         inode = dentry->d_inode;
2779
2780         retval = -EIO;
2781         if (le32_to_cpu(de->inode) != inode->i_ino)
2782                 goto end_unlink;
2783
2784         handle = ext4_journal_start(dir, EXT4_HT_DIR,
2785                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2786         if (IS_ERR(handle)) {
2787                 retval = PTR_ERR(handle);
2788                 handle = NULL;
2789                 goto end_unlink;
2790         }
2791
2792         if (IS_DIRSYNC(dir))
2793                 ext4_handle_sync(handle);
2794
2795         if (!inode->i_nlink) {
2796                 ext4_warning(inode->i_sb,
2797                              "Deleting nonexistent file (%lu), %d",
2798                              inode->i_ino, inode->i_nlink);
2799                 set_nlink(inode, 1);
2800         }
2801         retval = ext4_delete_entry(handle, dir, de, bh);
2802         if (retval)
2803                 goto end_unlink;
2804         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2805         ext4_update_dx_flag(dir);
2806         ext4_mark_inode_dirty(handle, dir);
2807         drop_nlink(inode);
2808         if (!inode->i_nlink)
2809                 ext4_orphan_add(handle, inode);
2810         inode->i_ctime = ext4_current_time(inode);
2811         ext4_mark_inode_dirty(handle, inode);
2812         retval = 0;
2813
2814 end_unlink:
2815         brelse(bh);
2816         if (handle)
2817                 ext4_journal_stop(handle);
2818         trace_ext4_unlink_exit(dentry, retval);
2819         return retval;
2820 }
2821
2822 static int ext4_symlink(struct inode *dir,
2823                         struct dentry *dentry, const char *symname)
2824 {
2825         handle_t *handle;
2826         struct inode *inode;
2827         int l, err, retries = 0;
2828         int credits;
2829
2830         l = strlen(symname)+1;
2831         if (l > dir->i_sb->s_blocksize)
2832                 return -ENAMETOOLONG;
2833
2834         dquot_initialize(dir);
2835
2836         if (l > EXT4_N_BLOCKS * 4) {
2837                 /*
2838                  * For non-fast symlinks, we just allocate inode and put it on
2839                  * orphan list in the first transaction => we need bitmap,
2840                  * group descriptor, sb, inode block, quota blocks, and
2841                  * possibly selinux xattr blocks.
2842                  */
2843                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2844                           EXT4_XATTR_TRANS_BLOCKS;
2845         } else {
2846                 /*
2847                  * Fast symlink. We have to add entry to directory
2848                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2849                  * allocate new inode (bitmap, group descriptor, inode block,
2850                  * quota blocks, sb is already counted in previous macros).
2851                  */
2852                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2853                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
2854         }
2855 retry:
2856         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
2857                                             &dentry->d_name, 0, NULL,
2858                                             EXT4_HT_DIR, credits);
2859         handle = ext4_journal_current_handle();
2860         err = PTR_ERR(inode);
2861         if (IS_ERR(inode))
2862                 goto out_stop;
2863
2864         if (l > EXT4_N_BLOCKS * 4) {
2865                 inode->i_op = &ext4_symlink_inode_operations;
2866                 ext4_set_aops(inode);
2867                 /*
2868                  * We cannot call page_symlink() with transaction started
2869                  * because it calls into ext4_write_begin() which can wait
2870                  * for transaction commit if we are running out of space
2871                  * and thus we deadlock. So we have to stop transaction now
2872                  * and restart it when symlink contents is written.
2873                  *
2874                  * To keep fs consistent in case of crash, we have to put inode
2875                  * to orphan list in the mean time.
2876                  */
2877                 drop_nlink(inode);
2878                 err = ext4_orphan_add(handle, inode);
2879                 ext4_journal_stop(handle);
2880                 if (err)
2881                         goto err_drop_inode;
2882                 err = __page_symlink(inode, symname, l, 1);
2883                 if (err)
2884                         goto err_drop_inode;
2885                 /*
2886                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2887                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2888                  */
2889                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2890                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2891                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2892                 if (IS_ERR(handle)) {
2893                         err = PTR_ERR(handle);
2894                         goto err_drop_inode;
2895                 }
2896                 set_nlink(inode, 1);
2897                 err = ext4_orphan_del(handle, inode);
2898                 if (err) {
2899                         ext4_journal_stop(handle);
2900                         clear_nlink(inode);
2901                         goto err_drop_inode;
2902                 }
2903         } else {
2904                 /* clear the extent format for fast symlink */
2905                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2906                 inode->i_op = &ext4_fast_symlink_inode_operations;
2907                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2908                 inode->i_size = l-1;
2909         }
2910         EXT4_I(inode)->i_disksize = inode->i_size;
2911         err = ext4_add_nondir(handle, dentry, inode);
2912         if (!err && IS_DIRSYNC(dir))
2913                 ext4_handle_sync(handle);
2914
2915 out_stop:
2916         if (handle)
2917                 ext4_journal_stop(handle);
2918         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2919                 goto retry;
2920         return err;
2921 err_drop_inode:
2922         unlock_new_inode(inode);
2923         iput(inode);
2924         return err;
2925 }
2926
2927 static int ext4_link(struct dentry *old_dentry,
2928                      struct inode *dir, struct dentry *dentry)
2929 {
2930         handle_t *handle;
2931         struct inode *inode = old_dentry->d_inode;
2932         int err, retries = 0;
2933
2934         if (inode->i_nlink >= EXT4_LINK_MAX)
2935                 return -EMLINK;
2936
2937         dquot_initialize(dir);
2938
2939 retry:
2940         handle = ext4_journal_start(dir, EXT4_HT_DIR,
2941                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2942                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
2943         if (IS_ERR(handle))
2944                 return PTR_ERR(handle);
2945
2946         if (IS_DIRSYNC(dir))
2947                 ext4_handle_sync(handle);
2948
2949         inode->i_ctime = ext4_current_time(inode);
2950         ext4_inc_count(handle, inode);
2951         ihold(inode);
2952
2953         err = ext4_add_entry(handle, dentry, inode);
2954         if (!err) {
2955                 ext4_mark_inode_dirty(handle, inode);
2956                 /* this can happen only for tmpfile being
2957                  * linked the first time
2958                  */
2959                 if (inode->i_nlink == 1)
2960                         ext4_orphan_del(handle, inode);
2961                 d_instantiate(dentry, inode);
2962         } else {
2963                 drop_nlink(inode);
2964                 iput(inode);
2965         }
2966         ext4_journal_stop(handle);
2967         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2968                 goto retry;
2969         return err;
2970 }
2971
2972
2973 /*
2974  * Try to find buffer head where contains the parent block.
2975  * It should be the inode block if it is inlined or the 1st block
2976  * if it is a normal dir.
2977  */
2978 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
2979                                         struct inode *inode,
2980                                         int *retval,
2981                                         struct ext4_dir_entry_2 **parent_de,
2982                                         int *inlined)
2983 {
2984         struct buffer_head *bh;
2985
2986         if (!ext4_has_inline_data(inode)) {
2987                 bh = ext4_read_dirblock(inode, 0, EITHER);
2988                 if (IS_ERR(bh)) {
2989                         *retval = PTR_ERR(bh);
2990                         return NULL;
2991                 }
2992                 *parent_de = ext4_next_entry(
2993                                         (struct ext4_dir_entry_2 *)bh->b_data,
2994                                         inode->i_sb->s_blocksize);
2995                 return bh;
2996         }
2997
2998         *inlined = 1;
2999         return ext4_get_first_inline_block(inode, parent_de, retval);
3000 }
3001
3002 struct ext4_renament {
3003         struct inode *dir;
3004         struct dentry *dentry;
3005         struct inode *inode;
3006         bool is_dir;
3007         int dir_nlink_delta;
3008
3009         /* entry for "dentry" */
3010         struct buffer_head *bh;
3011         struct ext4_dir_entry_2 *de;
3012         int inlined;
3013
3014         /* entry for ".." in inode if it's a directory */
3015         struct buffer_head *dir_bh;
3016         struct ext4_dir_entry_2 *parent_de;
3017         int dir_inlined;
3018 };
3019
3020 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3021 {
3022         int retval;
3023
3024         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3025                                               &retval, &ent->parent_de,
3026                                               &ent->dir_inlined);
3027         if (!ent->dir_bh)
3028                 return retval;
3029         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3030                 return -EIO;
3031         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3032         return ext4_journal_get_write_access(handle, ent->dir_bh);
3033 }
3034
3035 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3036                                   unsigned dir_ino)
3037 {
3038         int retval;
3039
3040         ent->parent_de->inode = cpu_to_le32(dir_ino);
3041         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3042         if (!ent->dir_inlined) {
3043                 if (is_dx(ent->inode)) {
3044                         retval = ext4_handle_dirty_dx_node(handle,
3045                                                            ent->inode,
3046                                                            ent->dir_bh);
3047                 } else {
3048                         retval = ext4_handle_dirty_dirent_node(handle,
3049                                                                ent->inode,
3050                                                                ent->dir_bh);
3051                 }
3052         } else {
3053                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3054         }
3055         if (retval) {
3056                 ext4_std_error(ent->dir->i_sb, retval);
3057                 return retval;
3058         }
3059         return 0;
3060 }
3061
3062 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3063                        unsigned ino, unsigned file_type)
3064 {
3065         int retval;
3066
3067         BUFFER_TRACE(ent->bh, "get write access");
3068         retval = ext4_journal_get_write_access(handle, ent->bh);
3069         if (retval)
3070                 return retval;
3071         ent->de->inode = cpu_to_le32(ino);
3072         if (EXT4_HAS_INCOMPAT_FEATURE(ent->dir->i_sb,
3073                                       EXT4_FEATURE_INCOMPAT_FILETYPE))
3074                 ent->de->file_type = file_type;
3075         ent->dir->i_version++;
3076         ent->dir->i_ctime = ent->dir->i_mtime =
3077                 ext4_current_time(ent->dir);
3078         ext4_mark_inode_dirty(handle, ent->dir);
3079         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3080         if (!ent->inlined) {
3081                 retval = ext4_handle_dirty_dirent_node(handle,
3082                                                        ent->dir, ent->bh);
3083                 if (unlikely(retval)) {
3084                         ext4_std_error(ent->dir->i_sb, retval);
3085                         return retval;
3086                 }
3087         }
3088         brelse(ent->bh);
3089         ent->bh = NULL;
3090
3091         return 0;
3092 }
3093
3094 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3095                                   const struct qstr *d_name)
3096 {
3097         int retval = -ENOENT;
3098         struct buffer_head *bh;
3099         struct ext4_dir_entry_2 *de;
3100
3101         bh = ext4_find_entry(dir, d_name, &de, NULL);
3102         if (bh) {
3103                 retval = ext4_delete_entry(handle, dir, de, bh);
3104                 brelse(bh);
3105         }
3106         return retval;
3107 }
3108
3109 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent)
3110 {
3111         int retval;
3112         /*
3113          * ent->de could have moved from under us during htree split, so make
3114          * sure that we are deleting the right entry.  We might also be pointing
3115          * to a stale entry in the unused part of ent->bh so just checking inum
3116          * and the name isn't enough.
3117          */
3118         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3119             ent->de->name_len != ent->dentry->d_name.len ||
3120             strncmp(ent->de->name, ent->dentry->d_name.name,
3121                     ent->de->name_len)) {
3122                 retval = ext4_find_delete_entry(handle, ent->dir,
3123                                                 &ent->dentry->d_name);
3124         } else {
3125                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3126                 if (retval == -ENOENT) {
3127                         retval = ext4_find_delete_entry(handle, ent->dir,
3128                                                         &ent->dentry->d_name);
3129                 }
3130         }
3131
3132         if (retval) {
3133                 ext4_warning(ent->dir->i_sb,
3134                                 "Deleting old file (%lu), %d, error=%d",
3135                                 ent->dir->i_ino, ent->dir->i_nlink, retval);
3136         }
3137 }
3138
3139 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3140 {
3141         if (ent->dir_nlink_delta) {
3142                 if (ent->dir_nlink_delta == -1)
3143                         ext4_dec_count(handle, ent->dir);
3144                 else
3145                         ext4_inc_count(handle, ent->dir);
3146                 ext4_mark_inode_dirty(handle, ent->dir);
3147         }
3148 }
3149
3150 /*
3151  * Anybody can rename anything with this: the permission checks are left to the
3152  * higher-level routines.
3153  *
3154  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3155  * while new_{dentry,inode) refers to the destination dentry/inode
3156  * This comes from rename(const char *oldpath, const char *newpath)
3157  */
3158 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3159                        struct inode *new_dir, struct dentry *new_dentry)
3160 {
3161         handle_t *handle = NULL;
3162         struct ext4_renament old = {
3163                 .dir = old_dir,
3164                 .dentry = old_dentry,
3165                 .inode = old_dentry->d_inode,
3166         };
3167         struct ext4_renament new = {
3168                 .dir = new_dir,
3169                 .dentry = new_dentry,
3170                 .inode = new_dentry->d_inode,
3171         };
3172         int retval;
3173
3174         dquot_initialize(old.dir);
3175         dquot_initialize(new.dir);
3176
3177         /* Initialize quotas before so that eventual writes go
3178          * in separate transaction */
3179         if (new.inode)
3180                 dquot_initialize(new.inode);
3181
3182         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3183         /*
3184          *  Check for inode number is _not_ due to possible IO errors.
3185          *  We might rmdir the source, keep it as pwd of some process
3186          *  and merrily kill the link to whatever was created under the
3187          *  same name. Goodbye sticky bit ;-<
3188          */
3189         retval = -ENOENT;
3190         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3191                 goto end_rename;
3192
3193         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3194                                  &new.de, &new.inlined);
3195         if (new.bh) {
3196                 if (!new.inode) {
3197                         brelse(new.bh);
3198                         new.bh = NULL;
3199                 }
3200         }
3201         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3202                 ext4_alloc_da_blocks(old.inode);
3203
3204         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3205                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3206                  EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3207         if (IS_ERR(handle))
3208                 return PTR_ERR(handle);
3209
3210         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3211                 ext4_handle_sync(handle);
3212
3213         if (S_ISDIR(old.inode->i_mode)) {
3214                 if (new.inode) {
3215                         retval = -ENOTEMPTY;
3216                         if (!empty_dir(new.inode))
3217                                 goto end_rename;
3218                 } else {
3219                         retval = -EMLINK;
3220                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3221                                 goto end_rename;
3222                 }
3223                 retval = ext4_rename_dir_prepare(handle, &old);
3224                 if (retval)
3225                         goto end_rename;
3226         }
3227         if (!new.bh) {
3228                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3229                 if (retval)
3230                         goto end_rename;
3231         } else {
3232                 retval = ext4_setent(handle, &new,
3233                                      old.inode->i_ino, old.de->file_type);
3234                 if (retval)
3235                         goto end_rename;
3236         }
3237
3238         /*
3239          * Like most other Unix systems, set the ctime for inodes on a
3240          * rename.
3241          */
3242         old.inode->i_ctime = ext4_current_time(old.inode);
3243         ext4_mark_inode_dirty(handle, old.inode);
3244
3245         /*
3246          * ok, that's it
3247          */
3248         ext4_rename_delete(handle, &old);
3249
3250         if (new.inode) {
3251                 ext4_dec_count(handle, new.inode);
3252                 new.inode->i_ctime = ext4_current_time(new.inode);
3253         }
3254         old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3255         ext4_update_dx_flag(old.dir);
3256         if (old.dir_bh) {
3257                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3258                 if (retval)
3259                         goto end_rename;
3260
3261                 ext4_dec_count(handle, old.dir);
3262                 if (new.inode) {
3263                         /* checked empty_dir above, can't have another parent,
3264                          * ext4_dec_count() won't work for many-linked dirs */
3265                         clear_nlink(new.inode);
3266                 } else {
3267                         ext4_inc_count(handle, new.dir);
3268                         ext4_update_dx_flag(new.dir);
3269                         ext4_mark_inode_dirty(handle, new.dir);
3270                 }
3271         }
3272         ext4_mark_inode_dirty(handle, old.dir);
3273         if (new.inode) {
3274                 ext4_mark_inode_dirty(handle, new.inode);
3275                 if (!new.inode->i_nlink)
3276                         ext4_orphan_add(handle, new.inode);
3277         }
3278         retval = 0;
3279
3280 end_rename:
3281         brelse(old.dir_bh);
3282         brelse(old.bh);
3283         brelse(new.bh);
3284         if (handle)
3285                 ext4_journal_stop(handle);
3286         return retval;
3287 }
3288
3289 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3290                              struct inode *new_dir, struct dentry *new_dentry)
3291 {
3292         handle_t *handle = NULL;
3293         struct ext4_renament old = {
3294                 .dir = old_dir,
3295                 .dentry = old_dentry,
3296                 .inode = old_dentry->d_inode,
3297         };
3298         struct ext4_renament new = {
3299                 .dir = new_dir,
3300                 .dentry = new_dentry,
3301                 .inode = new_dentry->d_inode,
3302         };
3303         u8 new_file_type;
3304         int retval;
3305
3306         dquot_initialize(old.dir);
3307         dquot_initialize(new.dir);
3308
3309         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3310                                  &old.de, &old.inlined);
3311         /*
3312          *  Check for inode number is _not_ due to possible IO errors.
3313          *  We might rmdir the source, keep it as pwd of some process
3314          *  and merrily kill the link to whatever was created under the
3315          *  same name. Goodbye sticky bit ;-<
3316          */
3317         retval = -ENOENT;
3318         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3319                 goto end_rename;
3320
3321         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3322                                  &new.de, &new.inlined);
3323
3324         /* RENAME_EXCHANGE case: old *and* new must both exist */
3325         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3326                 goto end_rename;
3327
3328         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3329                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3330                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3331         if (IS_ERR(handle))
3332                 return PTR_ERR(handle);
3333
3334         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3335                 ext4_handle_sync(handle);
3336
3337         if (S_ISDIR(old.inode->i_mode)) {
3338                 old.is_dir = true;
3339                 retval = ext4_rename_dir_prepare(handle, &old);
3340                 if (retval)
3341                         goto end_rename;
3342         }
3343         if (S_ISDIR(new.inode->i_mode)) {
3344                 new.is_dir = true;
3345                 retval = ext4_rename_dir_prepare(handle, &new);
3346                 if (retval)
3347                         goto end_rename;
3348         }
3349
3350         /*
3351          * Other than the special case of overwriting a directory, parents'
3352          * nlink only needs to be modified if this is a cross directory rename.
3353          */
3354         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3355                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3356                 new.dir_nlink_delta = -old.dir_nlink_delta;
3357                 retval = -EMLINK;
3358                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3359                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3360                         goto end_rename;
3361         }
3362
3363         new_file_type = new.de->file_type;
3364         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3365         if (retval)
3366                 goto end_rename;
3367
3368         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3369         if (retval)
3370                 goto end_rename;
3371
3372         /*
3373          * Like most other Unix systems, set the ctime for inodes on a
3374          * rename.
3375          */
3376         old.inode->i_ctime = ext4_current_time(old.inode);
3377         new.inode->i_ctime = ext4_current_time(new.inode);
3378         ext4_mark_inode_dirty(handle, old.inode);
3379         ext4_mark_inode_dirty(handle, new.inode);
3380
3381         if (old.dir_bh) {
3382                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3383                 if (retval)
3384                         goto end_rename;
3385         }
3386         if (new.dir_bh) {
3387                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3388                 if (retval)
3389                         goto end_rename;
3390         }
3391         ext4_update_dir_count(handle, &old);
3392         ext4_update_dir_count(handle, &new);
3393         retval = 0;
3394
3395 end_rename:
3396         brelse(old.dir_bh);
3397         brelse(new.dir_bh);
3398         brelse(old.bh);
3399         brelse(new.bh);
3400         if (handle)
3401                 ext4_journal_stop(handle);
3402         return retval;
3403 }
3404
3405 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3406                         struct inode *new_dir, struct dentry *new_dentry,
3407                         unsigned int flags)
3408 {
3409         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
3410                 return -EINVAL;
3411
3412         if (flags & RENAME_EXCHANGE) {
3413                 return ext4_cross_rename(old_dir, old_dentry,
3414                                          new_dir, new_dentry);
3415         }
3416         /*
3417          * Existence checking was done by the VFS, otherwise "RENAME_NOREPLACE"
3418          * is equivalent to regular rename.
3419          */
3420         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry);
3421 }
3422
3423 /*
3424  * directories can handle most operations...
3425  */
3426 const struct inode_operations ext4_dir_inode_operations = {
3427         .create         = ext4_create,
3428         .lookup         = ext4_lookup,
3429         .link           = ext4_link,
3430         .unlink         = ext4_unlink,
3431         .symlink        = ext4_symlink,
3432         .mkdir          = ext4_mkdir,
3433         .rmdir          = ext4_rmdir,
3434         .mknod          = ext4_mknod,
3435         .tmpfile        = ext4_tmpfile,
3436         .rename         = ext4_rename,
3437         .rename2        = ext4_rename2,
3438         .setattr        = ext4_setattr,
3439         .setxattr       = generic_setxattr,
3440         .getxattr       = generic_getxattr,
3441         .listxattr      = ext4_listxattr,
3442         .removexattr    = generic_removexattr,
3443         .get_acl        = ext4_get_acl,
3444         .set_acl        = ext4_set_acl,
3445         .fiemap         = ext4_fiemap,
3446 };
3447
3448 const struct inode_operations ext4_special_inode_operations = {
3449         .setattr        = ext4_setattr,
3450         .setxattr       = generic_setxattr,
3451         .getxattr       = generic_getxattr,
3452         .listxattr      = ext4_listxattr,
3453         .removexattr    = generic_removexattr,
3454         .get_acl        = ext4_get_acl,
3455         .set_acl        = ext4_set_acl,
3456 };