fs/ext4/namei.c

   1 /*
   2  *  linux/fs/ext4/namei.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/namei.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  *  Directory entry file type support and forward compatibility hooks
  18  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  19  *  Hash Tree Directory indexing (c)
  20  *      Daniel Phillips, 2001
  21  *  Hash Tree Directory indexing porting
  22  *      Christopher Li, 2002
  23  *  Hash Tree Directory indexing cleanup
  24  *      Theodore Ts'o, 2002
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/time.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/stat.h>
  32 #include <linux/string.h>
  33 #include <linux/quotaops.h>
  34 #include <linux/buffer_head.h>
  35 #include <linux/bio.h>
  36 #include "ext4.h"
  37 #include "ext4_jbd2.h"
  38
  39 #include "xattr.h"
  40 #include "acl.h"
  41
  42 #include <trace/events/ext4.h>
  43 /*
  44  * define how far ahead to read directories while searching them.
  45  */
  46 #define NAMEI_RA_CHUNKS  2
  47 #define NAMEI_RA_BLOCKS  4
  48 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  49
  50 static struct buffer_head *ext4_append(handle_t *handle,
  51                                         struct inode *inode,
  52                                         ext4_lblk_t *block)
  53 {
  54         struct buffer_head *bh;
  55         int err;
  56
  57         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  58                      ((inode->i_size >> 10) >=
  59                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
  60                 return ERR_PTR(-ENOSPC);
  61
  62         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  63
  64         bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
  65         if (IS_ERR(bh))
  66                 return bh;
  67         inode->i_size += inode->i_sb->s_blocksize;
  68         EXT4_I(inode)->i_disksize = inode->i_size;
  69         BUFFER_TRACE(bh, "get_write_access");
  70         err = ext4_journal_get_write_access(handle, bh);
  71         if (err) {
  72                 brelse(bh);
  73                 ext4_std_error(inode->i_sb, err);
  74                 return ERR_PTR(err);
  75         }
  76         return bh;
  77 }
  78
  79 static int ext4_dx_csum_verify(struct inode *inode,
  80                                struct ext4_dir_entry *dirent);
  81
  82 typedef enum {
  83         EITHER, INDEX, DIRENT
  84 } dirblock_type_t;
  85
  86 #define ext4_read_dirblock(inode, block, type) \
  87         __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
  88
  89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
  90                                                 ext4_lblk_t block,
  91                                                 dirblock_type_t type,
  92                                                 const char *func,
  93                                                 unsigned int line)
  94 {
  95         struct buffer_head *bh;
  96         struct ext4_dir_entry *dirent;
  97         int is_dx_block = 0;
  98
  99         bh = ext4_bread(NULL, inode, block, 0);
 100         if (IS_ERR(bh)) {
 101                 __ext4_warning(inode->i_sb, func, line,
 102                                "inode #%lu: lblock %lu: comm %s: "
 103                                "error %ld reading directory block",
 104                                inode->i_ino, (unsigned long)block,
 105                                current->comm, PTR_ERR(bh));
 106
 107                 return bh;
 108         }
 109         if (!bh) {
 110                 ext4_error_inode(inode, func, line, block,
 111                                  "Directory hole found");
 112                 return ERR_PTR(-EFSCORRUPTED);
 113         }
 114         dirent = (struct ext4_dir_entry *) bh->b_data;
 115         /* Determine whether or not we have an index block */
 116         if (is_dx(inode)) {
 117                 if (block == 0)
 118                         is_dx_block = 1;
 119                 else if (ext4_rec_len_from_disk(dirent->rec_len,
 120                                                 inode->i_sb->s_blocksize) ==
 121                          inode->i_sb->s_blocksize)
 122                         is_dx_block = 1;
 123         }
 124         if (!is_dx_block && type == INDEX) {
 125                 ext4_error_inode(inode, func, line, block,
 126                        "directory leaf block found instead of index block");
 127                 return ERR_PTR(-EFSCORRUPTED);
 128         }
 129         if (!ext4_has_metadata_csum(inode->i_sb) ||
 130             buffer_verified(bh))
 131                 return bh;
 132
 133         /*
 134          * An empty leaf block can get mistaken for a index block; for
 135          * this reason, we can only check the index checksum when the
 136          * caller is sure it should be an index block.
 137          */
 138         if (is_dx_block && type == INDEX) {
 139                 if (ext4_dx_csum_verify(inode, dirent))
 140                         set_buffer_verified(bh);
 141                 else {
 142                         ext4_error_inode(inode, func, line, block,
 143                                          "Directory index failed checksum");
 144                         brelse(bh);
 145                         return ERR_PTR(-EFSBADCRC);
 146                 }
 147         }
 148         if (!is_dx_block) {
 149                 if (ext4_dirent_csum_verify(inode, dirent))
 150                         set_buffer_verified(bh);
 151                 else {
 152                         ext4_error_inode(inode, func, line, block,
 153                                          "Directory block failed checksum");
 154                         brelse(bh);
 155                         return ERR_PTR(-EFSBADCRC);
 156                 }
 157         }
 158         return bh;
 159 }
 160
 161 #ifndef assert
 162 #define assert(test) J_ASSERT(test)
 163 #endif
 164
 165 #ifdef DX_DEBUG
 166 #define dxtrace(command) command
 167 #else
 168 #define dxtrace(command)
 169 #endif
 170
 171 struct fake_dirent
 172 {
 173         __le32 inode;
 174         __le16 rec_len;
 175         u8 name_len;
 176         u8 file_type;
 177 };
 178
 179 struct dx_countlimit
 180 {
 181         __le16 limit;
 182         __le16 count;
 183 };
 184
 185 struct dx_entry
 186 {
 187         __le32 hash;
 188         __le32 block;
 189 };
 190
 191 /*
 192  * dx_root_info is laid out so that if it should somehow get overlaid by a
 193  * dirent the two low bits of the hash version will be zero.  Therefore, the
 194  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 195  */
 196
 197 struct dx_root
 198 {
 199         struct fake_dirent dot;
 200         char dot_name[4];
 201         struct fake_dirent dotdot;
 202         char dotdot_name[4];
 203         struct dx_root_info
 204         {
 205                 __le32 reserved_zero;
 206                 u8 hash_version;
 207                 u8 info_length; /* 8 */
 208                 u8 indirect_levels;
 209                 u8 unused_flags;
 210         }
 211         info;
 212         struct dx_entry entries[0];
 213 };
 214
 215 struct dx_node
 216 {
 217         struct fake_dirent fake;
 218         struct dx_entry entries[0];
 219 };
 220
 221
 222 struct dx_frame
 223 {
 224         struct buffer_head *bh;
 225         struct dx_entry *entries;
 226         struct dx_entry *at;
 227 };
 228
 229 struct dx_map_entry
 230 {
 231         u32 hash;
 232         u16 offs;
 233         u16 size;
 234 };
 235
 236 /*
 237  * This goes at the end of each htree block.
 238  */
 239 struct dx_tail {
 240         u32 dt_reserved;
 241         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 242 };
 243
 244 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 245 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 246 static inline unsigned dx_get_hash(struct dx_entry *entry);
 247 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 248 static unsigned dx_get_count(struct dx_entry *entries);
 249 static unsigned dx_get_limit(struct dx_entry *entries);
 250 static void dx_set_count(struct dx_entry *entries, unsigned value);
 251 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 252 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 253 static unsigned dx_node_limit(struct inode *dir);
 254 static struct dx_frame *dx_probe(struct ext4_filename *fname,
 255                                  struct inode *dir,
 256                                  struct dx_hash_info *hinfo,
 257                                  struct dx_frame *frame);
 258 static void dx_release(struct dx_frame *frames);
 259 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 260                        unsigned blocksize, struct dx_hash_info *hinfo,
 261                        struct dx_map_entry map[]);
 262 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 263 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 264                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 265 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 266 static void dx_insert_block(struct dx_frame *frame,
 267                                         u32 hash, ext4_lblk_t block);
 268 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 269                                  struct dx_frame *frame,
 270                                  struct dx_frame *frames,
 271                                  __u32 *start_hash);
 272 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 273                 struct ext4_filename *fname,
 274                 struct ext4_dir_entry_2 **res_dir);
 275 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 276                              struct inode *dir, struct inode *inode);
 277
 278 /* checksumming functions */
 279 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 280                             unsigned int blocksize)
 281 {
 282         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 283         t->det_rec_len = ext4_rec_len_to_disk(
 284                         sizeof(struct ext4_dir_entry_tail), blocksize);
 285         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 286 }
 287
 288 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 289 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 290                                                    struct ext4_dir_entry *de)
 291 {
 292         struct ext4_dir_entry_tail *t;
 293
 294 #ifdef PARANOID
 295         struct ext4_dir_entry *d, *top;
 296
 297         d = de;
 298         top = (struct ext4_dir_entry *)(((void *)de) +
 299                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 300                 sizeof(struct ext4_dir_entry_tail)));
 301         while (d < top && d->rec_len)
 302                 d = (struct ext4_dir_entry *)(((void *)d) +
 303                     le16_to_cpu(d->rec_len));
 304
 305         if (d != top)
 306                 return NULL;
 307
 308         t = (struct ext4_dir_entry_tail *)d;
 309 #else
 310         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 311 #endif
 312
 313         if (t->det_reserved_zero1 ||
 314             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 315             t->det_reserved_zero2 ||
 316             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 317                 return NULL;
 318
 319         return t;
 320 }
 321
 322 static __le32 ext4_dirent_csum(struct inode *inode,
 323                                struct ext4_dir_entry *dirent, int size)
 324 {
 325         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 326         struct ext4_inode_info *ei = EXT4_I(inode);
 327         __u32 csum;
 328
 329         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 330         return cpu_to_le32(csum);
 331 }
 332
 333 #define warn_no_space_for_csum(inode)                                   \
 334         __warn_no_space_for_csum((inode), __func__, __LINE__)
 335
 336 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
 337                                      unsigned int line)
 338 {
 339         __ext4_warning_inode(inode, func, line,
 340                 "No space for directory leaf checksum. Please run e2fsck -D.");
 341 }
 342
 343 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 344 {
 345         struct ext4_dir_entry_tail *t;
 346
 347         if (!ext4_has_metadata_csum(inode->i_sb))
 348                 return 1;
 349
 350         t = get_dirent_tail(inode, dirent);
 351         if (!t) {
 352                 warn_no_space_for_csum(inode);
 353                 return 0;
 354         }
 355
 356         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 357                                                 (void *)t - (void *)dirent))
 358                 return 0;
 359
 360         return 1;
 361 }
 362
 363 static void ext4_dirent_csum_set(struct inode *inode,
 364                                  struct ext4_dir_entry *dirent)
 365 {
 366         struct ext4_dir_entry_tail *t;
 367
 368         if (!ext4_has_metadata_csum(inode->i_sb))
 369                 return;
 370
 371         t = get_dirent_tail(inode, dirent);
 372         if (!t) {
 373                 warn_no_space_for_csum(inode);
 374                 return;
 375         }
 376
 377         t->det_checksum = ext4_dirent_csum(inode, dirent,
 378                                            (void *)t - (void *)dirent);
 379 }
 380
 381 int ext4_handle_dirty_dirent_node(handle_t *handle,
 382                                   struct inode *inode,
 383                                   struct buffer_head *bh)
 384 {
 385         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 386         return ext4_handle_dirty_metadata(handle, inode, bh);
 387 }
 388
 389 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 390                                                struct ext4_dir_entry *dirent,
 391                                                int *offset)
 392 {
 393         struct ext4_dir_entry *dp;
 394         struct dx_root_info *root;
 395         int count_offset;
 396
 397         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 398                 count_offset = 8;
 399         else if (le16_to_cpu(dirent->rec_len) == 12) {
 400                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 401                 if (le16_to_cpu(dp->rec_len) !=
 402                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 403                         return NULL;
 404                 root = (struct dx_root_info *)(((void *)dp + 12));
 405                 if (root->reserved_zero ||
 406                     root->info_length != sizeof(struct dx_root_info))
 407                         return NULL;
 408                 count_offset = 32;
 409         } else
 410                 return NULL;
 411
 412         if (offset)
 413                 *offset = count_offset;
 414         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 415 }
 416
 417 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 418                            int count_offset, int count, struct dx_tail *t)
 419 {
 420         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 421         struct ext4_inode_info *ei = EXT4_I(inode);
 422         __u32 csum;
 423         __le32 save_csum;
 424         int size;
 425
 426         size = count_offset + (count * sizeof(struct dx_entry));
 427         save_csum = t->dt_checksum;
 428         t->dt_checksum = 0;
 429         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 430         csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
 431         t->dt_checksum = save_csum;
 432
 433         return cpu_to_le32(csum);
 434 }
 435
 436 static int ext4_dx_csum_verify(struct inode *inode,
 437                                struct ext4_dir_entry *dirent)
 438 {
 439         struct dx_countlimit *c;
 440         struct dx_tail *t;
 441         int count_offset, limit, count;
 442
 443         if (!ext4_has_metadata_csum(inode->i_sb))
 444                 return 1;
 445
 446         c = get_dx_countlimit(inode, dirent, &count_offset);
 447         if (!c) {
 448                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 449                 return 1;
 450         }
 451         limit = le16_to_cpu(c->limit);
 452         count = le16_to_cpu(c->count);
 453         if (count_offset + (limit * sizeof(struct dx_entry)) >
 454             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 455                 warn_no_space_for_csum(inode);
 456                 return 1;
 457         }
 458         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 459
 460         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 461                                             count, t))
 462                 return 0;
 463         return 1;
 464 }
 465
 466 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 467 {
 468         struct dx_countlimit *c;
 469         struct dx_tail *t;
 470         int count_offset, limit, count;
 471
 472         if (!ext4_has_metadata_csum(inode->i_sb))
 473                 return;
 474
 475         c = get_dx_countlimit(inode, dirent, &count_offset);
 476         if (!c) {
 477                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 478                 return;
 479         }
 480         limit = le16_to_cpu(c->limit);
 481         count = le16_to_cpu(c->count);
 482         if (count_offset + (limit * sizeof(struct dx_entry)) >
 483             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 484                 warn_no_space_for_csum(inode);
 485                 return;
 486         }
 487         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 488
 489         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 490 }
 491
 492 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 493                                             struct inode *inode,
 494                                             struct buffer_head *bh)
 495 {
 496         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 497         return ext4_handle_dirty_metadata(handle, inode, bh);
 498 }
 499
 500 /*
 501  * p is at least 6 bytes before the end of page
 502  */
 503 static inline struct ext4_dir_entry_2 *
 504 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 505 {
 506         return (struct ext4_dir_entry_2 *)((char *)p +
 507                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 508 }
 509
 510 /*
 511  * Future: use high four bits of block for coalesce-on-delete flags
 512  * Mask them off for now.
 513  */
 514
 515 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 516 {
 517         return le32_to_cpu(entry->block) & 0x00ffffff;
 518 }
 519
 520 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 521 {
 522         entry->block = cpu_to_le32(value);
 523 }
 524
 525 static inline unsigned dx_get_hash(struct dx_entry *entry)
 526 {
 527         return le32_to_cpu(entry->hash);
 528 }
 529
 530 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 531 {
 532         entry->hash = cpu_to_le32(value);
 533 }
 534
 535 static inline unsigned dx_get_count(struct dx_entry *entries)
 536 {
 537         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 538 }
 539
 540 static inline unsigned dx_get_limit(struct dx_entry *entries)
 541 {
 542         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 543 }
 544
 545 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 546 {
 547         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 548 }
 549
 550 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 551 {
 552         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 553 }
 554
 555 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 556 {
 557         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 558                 EXT4_DIR_REC_LEN(2) - infosize;
 559
 560         if (ext4_has_metadata_csum(dir->i_sb))
 561                 entry_space -= sizeof(struct dx_tail);
 562         return entry_space / sizeof(struct dx_entry);
 563 }
 564
 565 static inline unsigned dx_node_limit(struct inode *dir)
 566 {
 567         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 568
 569         if (ext4_has_metadata_csum(dir->i_sb))
 570                 entry_space -= sizeof(struct dx_tail);
 571         return entry_space / sizeof(struct dx_entry);
 572 }
 573
 574 /*
 575  * Debug
 576  */
 577 #ifdef DX_DEBUG
 578 static void dx_show_index(char * label, struct dx_entry *entries)
 579 {
 580         int i, n = dx_get_count (entries);
 581         printk(KERN_DEBUG "%s index ", label);
 582         for (i = 0; i < n; i++) {
 583                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 584                                 0, (unsigned long)dx_get_block(entries + i));
 585         }
 586         printk("\n");
 587 }
 588
 589 struct stats
 590 {
 591         unsigned names;
 592         unsigned space;
 593         unsigned bcount;
 594 };
 595
 596 static struct stats dx_show_leaf(struct inode *dir,
 597                                 struct dx_hash_info *hinfo,
 598                                 struct ext4_dir_entry_2 *de,
 599                                 int size, int show_names)
 600 {
 601         unsigned names = 0, space = 0;
 602         char *base = (char *) de;
 603         struct dx_hash_info h = *hinfo;
 604
 605         printk("names: ");
 606         while ((char *) de < base + size)
 607         {
 608                 if (de->inode)
 609                 {
 610                         if (show_names)
 611                         {
 612 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 613                                 int len;
 614                                 char *name;
 615                                 struct ext4_str fname_crypto_str
 616                                         = {.name = NULL, .len = 0};
 617                                 int res = 0;
 618
 619                                 name  = de->name;
 620                                 len = de->name_len;
 621                                 if (ext4_encrypted_inode(inode))
 622                                         res = ext4_get_encryption_info(dir);
 623                                 if (res) {
 624                                         printk(KERN_WARNING "Error setting up"
 625                                                " fname crypto: %d\n", res);
 626                                 }
 627                                 if (ctx == NULL) {
 628                                         /* Directory is not encrypted */
 629                                         ext4fs_dirhash(de->name,
 630                                                 de->name_len, &h);
 631                                         printk("%*.s:(U)%x.%u ", len,
 632                                                name, h.hash,
 633                                                (unsigned) ((char *) de
 634                                                            - base));
 635                                 } else {
 636                                         /* Directory is encrypted */
 637                                         res = ext4_fname_crypto_alloc_buffer(
 638                                                 ctx, de->name_len,
 639                                                 &fname_crypto_str);
 640                                         if (res < 0) {
 641                                                 printk(KERN_WARNING "Error "
 642                                                         "allocating crypto "
 643                                                         "buffer--skipping "
 644                                                         "crypto\n");
 645                                                 ctx = NULL;
 646                                         }
 647                                         res = ext4_fname_disk_to_usr(ctx, NULL, de,
 648                                                         &fname_crypto_str);
 649                                         if (res < 0) {
 650                                                 printk(KERN_WARNING "Error "
 651                                                         "converting filename "
 652                                                         "from disk to usr"
 653                                                         "\n");
 654                                                 name = "??";
 655                                                 len = 2;
 656                                         } else {
 657                                                 name = fname_crypto_str.name;
 658                                                 len = fname_crypto_str.len;
 659                                         }
 660                                         ext4fs_dirhash(de->name, de->name_len,
 661                                                        &h);
 662                                         printk("%*.s:(E)%x.%u ", len, name,
 663                                                h.hash, (unsigned) ((char *) de
 664                                                                    - base));
 665                                         ext4_fname_crypto_free_buffer(
 666                                                 &fname_crypto_str);
 667                                 }
 668 #else
 669                                 int len = de->name_len;
 670                                 char *name = de->name;
 671                                 ext4fs_dirhash(de->name, de->name_len, &h);
 672                                 printk("%*.s:%x.%u ", len, name, h.hash,
 673                                        (unsigned) ((char *) de - base));
 674 #endif
 675                         }
 676                         space += EXT4_DIR_REC_LEN(de->name_len);
 677                         names++;
 678                 }
 679                 de = ext4_next_entry(de, size);
 680         }
 681         printk("(%i)\n", names);
 682         return (struct stats) { names, space, 1 };
 683 }
 684
 685 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 686                              struct dx_entry *entries, int levels)
 687 {
 688         unsigned blocksize = dir->i_sb->s_blocksize;
 689         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 690         unsigned bcount = 0;
 691         struct buffer_head *bh;
 692         printk("%i indexed blocks...\n", count);
 693         for (i = 0; i < count; i++, entries++)
 694         {
 695                 ext4_lblk_t block = dx_get_block(entries);
 696                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 697                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 698                 struct stats stats;
 699                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 700                 bh = ext4_bread(NULL,dir, block, 0);
 701                 if (!bh || IS_ERR(bh))
 702                         continue;
 703                 stats = levels?
 704                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 705                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 706                         bh->b_data, blocksize, 0);
 707                 names += stats.names;
 708                 space += stats.space;
 709                 bcount += stats.bcount;
 710                 brelse(bh);
 711         }
 712         if (bcount)
 713                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 714                        levels ? "" : "   ", names, space/bcount,
 715                        (space/bcount)*100/blocksize);
 716         return (struct stats) { names, space, bcount};
 717 }
 718 #endif /* DX_DEBUG */
 719
 720 /*
 721  * Probe for a directory leaf block to search.
 722  *
 723  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 724  * error in the directory index, and the caller should fall back to
 725  * searching the directory normally.  The callers of dx_probe **MUST**
 726  * check for this error code, and make sure it never gets reflected
 727  * back to userspace.
 728  */
 729 static struct dx_frame *
 730 dx_probe(struct ext4_filename *fname, struct inode *dir,
 731          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 732 {
 733         unsigned count, indirect;
 734         struct dx_entry *at, *entries, *p, *q, *m;
 735         struct dx_root *root;
 736         struct dx_frame *frame = frame_in;
 737         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 738         u32 hash;
 739
 740         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 741         if (IS_ERR(frame->bh))
 742                 return (struct dx_frame *) frame->bh;
 743
 744         root = (struct dx_root *) frame->bh->b_data;
 745         if (root->info.hash_version != DX_HASH_TEA &&
 746             root->info.hash_version != DX_HASH_HALF_MD4 &&
 747             root->info.hash_version != DX_HASH_LEGACY) {
 748                 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
 749                                    root->info.hash_version);
 750                 goto fail;
 751         }
 752         if (fname)
 753                 hinfo = &fname->hinfo;
 754         hinfo->hash_version = root->info.hash_version;
 755         if (hinfo->hash_version <= DX_HASH_TEA)
 756                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 757         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 758         if (fname && fname_name(fname))
 759                 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
 760         hash = hinfo->hash;
 761
 762         if (root->info.unused_flags & 1) {
 763                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
 764                                    root->info.unused_flags);
 765                 goto fail;
 766         }
 767
 768         indirect = root->info.indirect_levels;
 769         if (indirect > 1) {
 770                 ext4_warning_inode(dir, "Unimplemented hash depth: %#06x",
 771                                    root->info.indirect_levels);
 772                 goto fail;
 773         }
 774
 775         entries = (struct dx_entry *)(((char *)&root->info) +
 776                                       root->info.info_length);
 777
 778         if (dx_get_limit(entries) != dx_root_limit(dir,
 779                                                    root->info.info_length)) {
 780                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 781                                    dx_get_limit(entries),
 782                                    dx_root_limit(dir, root->info.info_length));
 783                 goto fail;
 784         }
 785
 786         dxtrace(printk("Look up %x", hash));
 787         while (1) {
 788                 count = dx_get_count(entries);
 789                 if (!count || count > dx_get_limit(entries)) {
 790                         ext4_warning_inode(dir,
 791                                            "dx entry: count %u beyond limit %u",
 792                                            count, dx_get_limit(entries));
 793                         goto fail;
 794                 }
 795
 796                 p = entries + 1;
 797                 q = entries + count - 1;
 798                 while (p <= q) {
 799                         m = p + (q - p) / 2;
 800                         dxtrace(printk("."));
 801                         if (dx_get_hash(m) > hash)
 802                                 q = m - 1;
 803                         else
 804                                 p = m + 1;
 805                 }
 806
 807                 if (0) { // linear search cross check
 808                         unsigned n = count - 1;
 809                         at = entries;
 810                         while (n--)
 811                         {
 812                                 dxtrace(printk(","));
 813                                 if (dx_get_hash(++at) > hash)
 814                                 {
 815                                         at--;
 816                                         break;
 817                                 }
 818                         }
 819                         assert (at == p - 1);
 820                 }
 821
 822                 at = p - 1;
 823                 dxtrace(printk(" %x->%u\n", at == entries ? 0 : dx_get_hash(at),
 824                                dx_get_block(at)));
 825                 frame->entries = entries;
 826                 frame->at = at;
 827                 if (!indirect--)
 828                         return frame;
 829                 frame++;
 830                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 831                 if (IS_ERR(frame->bh)) {
 832                         ret_err = (struct dx_frame *) frame->bh;
 833                         frame->bh = NULL;
 834                         goto fail;
 835                 }
 836                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 837
 838                 if (dx_get_limit(entries) != dx_node_limit(dir)) {
 839                         ext4_warning_inode(dir,
 840                                 "dx entry: limit %u != node limit %u",
 841                                 dx_get_limit(entries), dx_node_limit(dir));
 842                         goto fail;
 843                 }
 844         }
 845 fail:
 846         while (frame >= frame_in) {
 847                 brelse(frame->bh);
 848                 frame--;
 849         }
 850
 851         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 852                 ext4_warning_inode(dir,
 853                         "Corrupt directory, running e2fsck is recommended");
 854         return ret_err;
 855 }
 856
 857 static void dx_release(struct dx_frame *frames)
 858 {
 859         if (frames[0].bh == NULL)
 860                 return;
 861
 862         if (((struct dx_root *)frames[0].bh->b_data)->info.indirect_levels)
 863                 brelse(frames[1].bh);
 864         brelse(frames[0].bh);
 865 }
 866
 867 /*
 868  * This function increments the frame pointer to search the next leaf
 869  * block, and reads in the necessary intervening nodes if the search
 870  * should be necessary.  Whether or not the search is necessary is
 871  * controlled by the hash parameter.  If the hash value is even, then
 872  * the search is only continued if the next block starts with that
 873  * hash value.  This is used if we are searching for a specific file.
 874  *
 875  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 876  *
 877  * This function returns 1 if the caller should continue to search,
 878  * or 0 if it should not.  If there is an error reading one of the
 879  * index blocks, it will a negative error code.
 880  *
 881  * If start_hash is non-null, it will be filled in with the starting
 882  * hash of the next page.
 883  */
 884 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 885                                  struct dx_frame *frame,
 886                                  struct dx_frame *frames,
 887                                  __u32 *start_hash)
 888 {
 889         struct dx_frame *p;
 890         struct buffer_head *bh;
 891         int num_frames = 0;
 892         __u32 bhash;
 893
 894         p = frame;
 895         /*
 896          * Find the next leaf page by incrementing the frame pointer.
 897          * If we run out of entries in the interior node, loop around and
 898          * increment pointer in the parent node.  When we break out of
 899          * this loop, num_frames indicates the number of interior
 900          * nodes need to be read.
 901          */
 902         while (1) {
 903                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 904                         break;
 905                 if (p == frames)
 906                         return 0;
 907                 num_frames++;
 908                 p--;
 909         }
 910
 911         /*
 912          * If the hash is 1, then continue only if the next page has a
 913          * continuation hash of any value.  This is used for readdir
 914          * handling.  Otherwise, check to see if the hash matches the
 915          * desired contiuation hash.  If it doesn't, return since
 916          * there's no point to read in the successive index pages.
 917          */
 918         bhash = dx_get_hash(p->at);
 919         if (start_hash)
 920                 *start_hash = bhash;
 921         if ((hash & 1) == 0) {
 922                 if ((bhash & ~1) != hash)
 923                         return 0;
 924         }
 925         /*
 926          * If the hash is HASH_NB_ALWAYS, we always go to the next
 927          * block so no check is necessary
 928          */
 929         while (num_frames--) {
 930                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 931                 if (IS_ERR(bh))
 932                         return PTR_ERR(bh);
 933                 p++;
 934                 brelse(p->bh);
 935                 p->bh = bh;
 936                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 937         }
 938         return 1;
 939 }
 940
 941
 942 /*
 943  * This function fills a red-black tree with information from a
 944  * directory block.  It returns the number directory entries loaded
 945  * into the tree.  If there is an error it is returned in err.
 946  */
 947 static int htree_dirblock_to_tree(struct file *dir_file,
 948                                   struct inode *dir, ext4_lblk_t block,
 949                                   struct dx_hash_info *hinfo,
 950                                   __u32 start_hash, __u32 start_minor_hash)
 951 {
 952         struct buffer_head *bh;
 953         struct ext4_dir_entry_2 *de, *top;
 954         int err = 0, count = 0;
 955         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
 956
 957         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 958                                                         (unsigned long)block));
 959         bh = ext4_read_dirblock(dir, block, DIRENT);
 960         if (IS_ERR(bh))
 961                 return PTR_ERR(bh);
 962
 963         de = (struct ext4_dir_entry_2 *) bh->b_data;
 964         top = (struct ext4_dir_entry_2 *) ((char *) de +
 965                                            dir->i_sb->s_blocksize -
 966                                            EXT4_DIR_REC_LEN(0));
 967 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 968         /* Check if the directory is encrypted */
 969         if (ext4_encrypted_inode(dir)) {
 970                 err = ext4_get_encryption_info(dir);
 971                 if (err < 0) {
 972                         brelse(bh);
 973                         return err;
 974                 }
 975                 err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
 976                                                      &fname_crypto_str);
 977                 if (err < 0) {
 978                         brelse(bh);
 979                         return err;
 980                 }
 981         }
 982 #endif
 983         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 984                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 985                                 bh->b_data, bh->b_size,
 986                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 987                                          + ((char *)de - bh->b_data))) {
 988                         /* silently ignore the rest of the block */
 989                         break;
 990                 }
 991                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 992                 if ((hinfo->hash < start_hash) ||
 993                     ((hinfo->hash == start_hash) &&
 994                      (hinfo->minor_hash < start_minor_hash)))
 995                         continue;
 996                 if (de->inode == 0)
 997                         continue;
 998                 if (!ext4_encrypted_inode(dir)) {
 999                         tmp_str.name = de->name;
1000                         tmp_str.len = de->name_len;
1001                         err = ext4_htree_store_dirent(dir_file,
1002                                    hinfo->hash, hinfo->minor_hash, de,
1003                                    &tmp_str);
1004                 } else {
1005                         int save_len = fname_crypto_str.len;
1006
1007                         /* Directory is encrypted */
1008                         err = ext4_fname_disk_to_usr(dir, hinfo, de,
1009                                                      &fname_crypto_str);
1010                         if (err < 0) {
1011                                 count = err;
1012                                 goto errout;
1013                         }
1014                         err = ext4_htree_store_dirent(dir_file,
1015                                    hinfo->hash, hinfo->minor_hash, de,
1016                                         &fname_crypto_str);
1017                         fname_crypto_str.len = save_len;
1018                 }
1019                 if (err != 0) {
1020                         count = err;
1021                         goto errout;
1022                 }
1023                 count++;
1024         }
1025 errout:
1026         brelse(bh);
1027 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1028         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1029 #endif
1030         return count;
1031 }
1032
1033
1034 /*
1035  * This function fills a red-black tree with information from a
1036  * directory.  We start scanning the directory in hash order, starting
1037  * at start_hash and start_minor_hash.
1038  *
1039  * This function returns the number of entries inserted into the tree,
1040  * or a negative error code.
1041  */
1042 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1043                          __u32 start_minor_hash, __u32 *next_hash)
1044 {
1045         struct dx_hash_info hinfo;
1046         struct ext4_dir_entry_2 *de;
1047         struct dx_frame frames[2], *frame;
1048         struct inode *dir;
1049         ext4_lblk_t block;
1050         int count = 0;
1051         int ret, err;
1052         __u32 hashval;
1053         struct ext4_str tmp_str;
1054
1055         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1056                        start_hash, start_minor_hash));
1057         dir = file_inode(dir_file);
1058         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1059                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1060                 if (hinfo.hash_version <= DX_HASH_TEA)
1061                         hinfo.hash_version +=
1062                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1063                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1064                 if (ext4_has_inline_data(dir)) {
1065                         int has_inline_data = 1;
1066                         count = htree_inlinedir_to_tree(dir_file, dir, 0,
1067                                                         &hinfo, start_hash,
1068                                                         start_minor_hash,
1069                                                         &has_inline_data);
1070                         if (has_inline_data) {
1071                                 *next_hash = ~0;
1072                                 return count;
1073                         }
1074                 }
1075                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1076                                                start_hash, start_minor_hash);
1077                 *next_hash = ~0;
1078                 return count;
1079         }
1080         hinfo.hash = start_hash;
1081         hinfo.minor_hash = 0;
1082         frame = dx_probe(NULL, dir, &hinfo, frames);
1083         if (IS_ERR(frame))
1084                 return PTR_ERR(frame);
1085
1086         /* Add '.' and '..' from the htree header */
1087         if (!start_hash && !start_minor_hash) {
1088                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1089                 tmp_str.name = de->name;
1090                 tmp_str.len = de->name_len;
1091                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1092                                               de, &tmp_str);
1093                 if (err != 0)
1094                         goto errout;
1095                 count++;
1096         }
1097         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1098                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1099                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1100                 tmp_str.name = de->name;
1101                 tmp_str.len = de->name_len;
1102                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1103                                               de, &tmp_str);
1104                 if (err != 0)
1105                         goto errout;
1106                 count++;
1107         }
1108
1109         while (1) {
1110                 if (signal_pending(current)) {
1111                         err = -ERESTARTSYS;
1112                         goto errout;
1113                 }
1114                 cond_resched();
1115                 block = dx_get_block(frame->at);
1116                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1117                                              start_hash, start_minor_hash);
1118                 if (ret < 0) {
1119                         err = ret;
1120                         goto errout;
1121                 }
1122                 count += ret;
1123                 hashval = ~0;
1124                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1125                                             frame, frames, &hashval);
1126                 *next_hash = hashval;
1127                 if (ret < 0) {
1128                         err = ret;
1129                         goto errout;
1130                 }
1131                 /*
1132                  * Stop if:  (a) there are no more entries, or
1133                  * (b) we have inserted at least one entry and the
1134                  * next hash value is not a continuation
1135                  */
1136                 if ((ret == 0) ||
1137                     (count && ((hashval & 1) == 0)))
1138                         break;
1139         }
1140         dx_release(frames);
1141         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1142                        "next hash: %x\n", count, *next_hash));
1143         return count;
1144 errout:
1145         dx_release(frames);
1146         return (err);
1147 }
1148
1149 static inline int search_dirblock(struct buffer_head *bh,
1150                                   struct inode *dir,
1151                                   struct ext4_filename *fname,
1152                                   const struct qstr *d_name,
1153                                   unsigned int offset,
1154                                   struct ext4_dir_entry_2 **res_dir)
1155 {
1156         return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1157                                fname, d_name, offset, res_dir);
1158 }
1159
1160 /*
1161  * Directory block splitting, compacting
1162  */
1163
1164 /*
1165  * Create map of hash values, offsets, and sizes, stored at end of block.
1166  * Returns number of entries mapped.
1167  */
1168 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1169                        unsigned blocksize, struct dx_hash_info *hinfo,
1170                        struct dx_map_entry *map_tail)
1171 {
1172         int count = 0;
1173         char *base = (char *) de;
1174         struct dx_hash_info h = *hinfo;
1175
1176         while ((char *) de < base + blocksize) {
1177                 if (de->name_len && de->inode) {
1178                         ext4fs_dirhash(de->name, de->name_len, &h);
1179                         map_tail--;
1180                         map_tail->hash = h.hash;
1181                         map_tail->offs = ((char *) de - base)>>2;
1182                         map_tail->size = le16_to_cpu(de->rec_len);
1183                         count++;
1184                         cond_resched();
1185                 }
1186                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1187                 de = ext4_next_entry(de, blocksize);
1188         }
1189         return count;
1190 }
1191
1192 /* Sort map by hash value */
1193 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1194 {
1195         struct dx_map_entry *p, *q, *top = map + count - 1;
1196         int more;
1197         /* Combsort until bubble sort doesn't suck */
1198         while (count > 2) {
1199                 count = count*10/13;
1200                 if (count - 9 < 2) /* 9, 10 -> 11 */
1201                         count = 11;
1202                 for (p = top, q = p - count; q >= map; p--, q--)
1203                         if (p->hash < q->hash)
1204                                 swap(*p, *q);
1205         }
1206         /* Garden variety bubble sort */
1207         do {
1208                 more = 0;
1209                 q = top;
1210                 while (q-- > map) {
1211                         if (q[1].hash >= q[0].hash)
1212                                 continue;
1213                         swap(*(q+1), *q);
1214                         more = 1;
1215                 }
1216         } while(more);
1217 }
1218
1219 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1220 {
1221         struct dx_entry *entries = frame->entries;
1222         struct dx_entry *old = frame->at, *new = old + 1;
1223         int count = dx_get_count(entries);
1224
1225         assert(count < dx_get_limit(entries));
1226         assert(old < entries + count);
1227         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1228         dx_set_hash(new, hash);
1229         dx_set_block(new, block);
1230         dx_set_count(entries, count + 1);
1231 }
1232
1233 /*
1234  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1235  *
1236  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1237  * `de != NULL' is guaranteed by caller.
1238  */
1239 static inline int ext4_match(struct ext4_filename *fname,
1240                              struct ext4_dir_entry_2 *de)
1241 {
1242         const void *name = fname_name(fname);
1243         u32 len = fname_len(fname);
1244
1245         if (!de->inode)
1246                 return 0;
1247
1248 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1249         if (unlikely(!name)) {
1250                 if (fname->usr_fname->name[0] == '_') {
1251                         int ret;
1252                         if (de->name_len < 16)
1253                                 return 0;
1254                         ret = memcmp(de->name + de->name_len - 16,
1255                                      fname->crypto_buf.name + 8, 16);
1256                         return (ret == 0) ? 1 : 0;
1257                 }
1258                 name = fname->crypto_buf.name;
1259                 len = fname->crypto_buf.len;
1260         }
1261 #endif
1262         if (de->name_len != len)
1263                 return 0;
1264         return (memcmp(de->name, name, len) == 0) ? 1 : 0;
1265 }
1266
1267 /*
1268  * Returns 0 if not found, -1 on failure, and 1 on success
1269  */
1270 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1271                     struct inode *dir, struct ext4_filename *fname,
1272                     const struct qstr *d_name,
1273                     unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1274 {
1275         struct ext4_dir_entry_2 * de;
1276         char * dlimit;
1277         int de_len;
1278         int res;
1279
1280         de = (struct ext4_dir_entry_2 *)search_buf;
1281         dlimit = search_buf + buf_size;
1282         while ((char *) de < dlimit) {
1283                 /* this code is executed quadratically often */
1284                 /* do minimal checking `by hand' */
1285                 if ((char *) de + de->name_len <= dlimit) {
1286                         res = ext4_match(fname, de);
1287                         if (res < 0) {
1288                                 res = -1;
1289                                 goto return_result;
1290                         }
1291                         if (res > 0) {
1292                                 /* found a match - just to be sure, do
1293                                  * a full check */
1294                                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1295                                                 bh->b_data,
1296                                                  bh->b_size, offset)) {
1297                                         res = -1;
1298                                         goto return_result;
1299                                 }
1300                                 *res_dir = de;
1301                                 res = 1;
1302                                 goto return_result;
1303                         }
1304
1305                 }
1306                 /* prevent looping on a bad block */
1307                 de_len = ext4_rec_len_from_disk(de->rec_len,
1308                                                 dir->i_sb->s_blocksize);
1309                 if (de_len <= 0) {
1310                         res = -1;
1311                         goto return_result;
1312                 }
1313                 offset += de_len;
1314                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1315         }
1316
1317         res = 0;
1318 return_result:
1319         return res;
1320 }
1321
1322 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1323                                struct ext4_dir_entry *de)
1324 {
1325         struct super_block *sb = dir->i_sb;
1326
1327         if (!is_dx(dir))
1328                 return 0;
1329         if (block == 0)
1330                 return 1;
1331         if (de->inode == 0 &&
1332             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1333                         sb->s_blocksize)
1334                 return 1;
1335         return 0;
1336 }
1337
1338 /*
1339  *      ext4_find_entry()
1340  *
1341  * finds an entry in the specified directory with the wanted name. It
1342  * returns the cache buffer in which the entry was found, and the entry
1343  * itself (as a parameter - res_dir). It does NOT read the inode of the
1344  * entry - you'll have to do that yourself if you want to.
1345  *
1346  * The returned buffer_head has ->b_count elevated.  The caller is expected
1347  * to brelse() it when appropriate.
1348  */
1349 static struct buffer_head * ext4_find_entry (struct inode *dir,
1350                                         const struct qstr *d_name,
1351                                         struct ext4_dir_entry_2 **res_dir,
1352                                         int *inlined)
1353 {
1354         struct super_block *sb;
1355         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1356         struct buffer_head *bh, *ret = NULL;
1357         ext4_lblk_t start, block, b;
1358         const u8 *name = d_name->name;
1359         int ra_max = 0;         /* Number of bh's in the readahead
1360                                    buffer, bh_use[] */
1361         int ra_ptr = 0;         /* Current index into readahead
1362                                    buffer */
1363         int num = 0;
1364         ext4_lblk_t  nblocks;
1365         int i, namelen, retval;
1366         struct ext4_filename fname;
1367
1368         *res_dir = NULL;
1369         sb = dir->i_sb;
1370         namelen = d_name->len;
1371         if (namelen > EXT4_NAME_LEN)
1372                 return NULL;
1373
1374         retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1375         if (retval)
1376                 return ERR_PTR(retval);
1377
1378         if (ext4_has_inline_data(dir)) {
1379                 int has_inline_data = 1;
1380                 ret = ext4_find_inline_entry(dir, &fname, d_name, res_dir,
1381                                              &has_inline_data);
1382                 if (has_inline_data) {
1383                         if (inlined)
1384                                 *inlined = 1;
1385                         goto cleanup_and_exit;
1386                 }
1387         }
1388
1389         if ((namelen <= 2) && (name[0] == '.') &&
1390             (name[1] == '.' || name[1] == '\0')) {
1391                 /*
1392                  * "." or ".." will only be in the first block
1393                  * NFS may look up ".."; "." should be handled by the VFS
1394                  */
1395                 block = start = 0;
1396                 nblocks = 1;
1397                 goto restart;
1398         }
1399         if (is_dx(dir)) {
1400                 ret = ext4_dx_find_entry(dir, &fname, res_dir);
1401                 /*
1402                  * On success, or if the error was file not found,
1403                  * return.  Otherwise, fall back to doing a search the
1404                  * old fashioned way.
1405                  */
1406                 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1407                         goto cleanup_and_exit;
1408                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1409                                "falling back\n"));
1410         }
1411         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1412         start = EXT4_I(dir)->i_dir_start_lookup;
1413         if (start >= nblocks)
1414                 start = 0;
1415         block = start;
1416 restart:
1417         do {
1418                 /*
1419                  * We deal with the read-ahead logic here.
1420                  */
1421                 if (ra_ptr >= ra_max) {
1422                         /* Refill the readahead buffer */
1423                         ra_ptr = 0;
1424                         b = block;
1425                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1426                                 /*
1427                                  * Terminate if we reach the end of the
1428                                  * directory and must wrap, or if our
1429                                  * search has finished at this block.
1430                                  */
1431                                 if (b >= nblocks || (num && block == start)) {
1432                                         bh_use[ra_max] = NULL;
1433                                         break;
1434                                 }
1435                                 num++;
1436                                 bh = ext4_getblk(NULL, dir, b++, 0);
1437                                 if (IS_ERR(bh)) {
1438                                         if (ra_max == 0) {
1439                                                 ret = bh;
1440                                                 goto cleanup_and_exit;
1441                                         }
1442                                         break;
1443                                 }
1444                                 bh_use[ra_max] = bh;
1445                                 if (bh)
1446                                         ll_rw_block(READ | REQ_META | REQ_PRIO,
1447                                                     1, &bh);
1448                         }
1449                 }
1450                 if ((bh = bh_use[ra_ptr++]) == NULL)
1451                         goto next;
1452                 wait_on_buffer(bh);
1453                 if (!buffer_uptodate(bh)) {
1454                         /* read error, skip block & hope for the best */
1455                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1456                                          (unsigned long) block);
1457                         brelse(bh);
1458                         goto next;
1459                 }
1460                 if (!buffer_verified(bh) &&
1461                     !is_dx_internal_node(dir, block,
1462                                          (struct ext4_dir_entry *)bh->b_data) &&
1463                     !ext4_dirent_csum_verify(dir,
1464                                 (struct ext4_dir_entry *)bh->b_data)) {
1465                         EXT4_ERROR_INODE(dir, "checksumming directory "
1466                                          "block %lu", (unsigned long)block);
1467                         brelse(bh);
1468                         goto next;
1469                 }
1470                 set_buffer_verified(bh);
1471                 i = search_dirblock(bh, dir, &fname, d_name,
1472                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1473                 if (i == 1) {
1474                         EXT4_I(dir)->i_dir_start_lookup = block;
1475                         ret = bh;
1476                         goto cleanup_and_exit;
1477                 } else {
1478                         brelse(bh);
1479                         if (i < 0)
1480                                 goto cleanup_and_exit;
1481                 }
1482         next:
1483                 if (++block >= nblocks)
1484                         block = 0;
1485         } while (block != start);
1486
1487         /*
1488          * If the directory has grown while we were searching, then
1489          * search the last part of the directory before giving up.
1490          */
1491         block = nblocks;
1492         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1493         if (block < nblocks) {
1494                 start = 0;
1495                 goto restart;
1496         }
1497
1498 cleanup_and_exit:
1499         /* Clean up the read-ahead blocks */
1500         for (; ra_ptr < ra_max; ra_ptr++)
1501                 brelse(bh_use[ra_ptr]);
1502         ext4_fname_free_filename(&fname);
1503         return ret;
1504 }
1505
1506 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1507                         struct ext4_filename *fname,
1508                         struct ext4_dir_entry_2 **res_dir)
1509 {
1510         struct super_block * sb = dir->i_sb;
1511         struct dx_frame frames[2], *frame;
1512         const struct qstr *d_name = fname->usr_fname;
1513         struct buffer_head *bh;
1514         ext4_lblk_t block;
1515         int retval;
1516
1517 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1518         *res_dir = NULL;
1519 #endif
1520         frame = dx_probe(fname, dir, NULL, frames);
1521         if (IS_ERR(frame))
1522                 return (struct buffer_head *) frame;
1523         do {
1524                 block = dx_get_block(frame->at);
1525                 bh = ext4_read_dirblock(dir, block, DIRENT);
1526                 if (IS_ERR(bh))
1527                         goto errout;
1528
1529                 retval = search_dirblock(bh, dir, fname, d_name,
1530                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1531                                          res_dir);
1532                 if (retval == 1)
1533                         goto success;
1534                 brelse(bh);
1535                 if (retval == -1) {
1536                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1537                         goto errout;
1538                 }
1539
1540                 /* Check to see if we should continue to search */
1541                 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1542                                                frames, NULL);
1543                 if (retval < 0) {
1544                         ext4_warning_inode(dir,
1545                                 "error %d reading directory index block",
1546                                 retval);
1547                         bh = ERR_PTR(retval);
1548                         goto errout;
1549                 }
1550         } while (retval == 1);
1551
1552         bh = NULL;
1553 errout:
1554         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1555 success:
1556         dx_release(frames);
1557         return bh;
1558 }
1559
1560 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1561 {
1562         struct inode *inode;
1563         struct ext4_dir_entry_2 *de;
1564         struct buffer_head *bh;
1565
1566        if (ext4_encrypted_inode(dir)) {
1567                int res = ext4_get_encryption_info(dir);
1568
1569                 /*
1570                  * This should be a properly defined flag for
1571                  * dentry->d_flags when we uplift this to the VFS.
1572                  * d_fsdata is set to (void *) 1 if if the dentry is
1573                  * created while the directory was encrypted and we
1574                  * don't have access to the key.
1575                  */
1576                dentry->d_fsdata = NULL;
1577                if (ext4_encryption_info(dir))
1578                        dentry->d_fsdata = (void *) 1;
1579                d_set_d_op(dentry, &ext4_encrypted_d_ops);
1580                if (res && res != -ENOKEY)
1581                        return ERR_PTR(res);
1582        }
1583
1584         if (dentry->d_name.len > EXT4_NAME_LEN)
1585                 return ERR_PTR(-ENAMETOOLONG);
1586
1587         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1588         if (IS_ERR(bh))
1589                 return (struct dentry *) bh;
1590         inode = NULL;
1591         if (bh) {
1592                 __u32 ino = le32_to_cpu(de->inode);
1593                 brelse(bh);
1594                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1595                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1596                         return ERR_PTR(-EFSCORRUPTED);
1597                 }
1598                 if (unlikely(ino == dir->i_ino)) {
1599                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1600                                          dentry);
1601                         return ERR_PTR(-EFSCORRUPTED);
1602                 }
1603                 inode = ext4_iget_normal(dir->i_sb, ino);
1604                 if (inode == ERR_PTR(-ESTALE)) {
1605                         EXT4_ERROR_INODE(dir,
1606                                          "deleted inode referenced: %u",
1607                                          ino);
1608                         return ERR_PTR(-EFSCORRUPTED);
1609                 }
1610                 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1611                     (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1612                     !ext4_is_child_context_consistent_with_parent(dir,
1613                                                                   inode)) {
1614                         int nokey = ext4_encrypted_inode(inode) &&
1615                                 !ext4_encryption_info(inode);
1616
1617                         iput(inode);
1618                         if (nokey)
1619                                 return ERR_PTR(-ENOKEY);
1620                         ext4_warning(inode->i_sb,
1621                                      "Inconsistent encryption contexts: %lu/%lu\n",
1622                                      (unsigned long) dir->i_ino,
1623                                      (unsigned long) inode->i_ino);
1624                         return ERR_PTR(-EPERM);
1625                 }
1626         }
1627         return d_splice_alias(inode, dentry);
1628 }
1629
1630
1631 struct dentry *ext4_get_parent(struct dentry *child)
1632 {
1633         __u32 ino;
1634         static const struct qstr dotdot = QSTR_INIT("..", 2);
1635         struct ext4_dir_entry_2 * de;
1636         struct buffer_head *bh;
1637
1638         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1639         if (IS_ERR(bh))
1640                 return (struct dentry *) bh;
1641         if (!bh)
1642                 return ERR_PTR(-ENOENT);
1643         ino = le32_to_cpu(de->inode);
1644         brelse(bh);
1645
1646         if (!ext4_valid_inum(d_inode(child)->i_sb, ino)) {
1647                 EXT4_ERROR_INODE(d_inode(child),
1648                                  "bad parent inode number: %u", ino);
1649                 return ERR_PTR(-EFSCORRUPTED);
1650         }
1651
1652         return d_obtain_alias(ext4_iget_normal(d_inode(child)->i_sb, ino));
1653 }
1654
1655 /*
1656  * Move count entries from end of map between two memory locations.
1657  * Returns pointer to last entry moved.
1658  */
1659 static struct ext4_dir_entry_2 *
1660 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1661                 unsigned blocksize)
1662 {
1663         unsigned rec_len = 0;
1664
1665         while (count--) {
1666                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1667                                                 (from + (map->offs<<2));
1668                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1669                 memcpy (to, de, rec_len);
1670                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1671                                 ext4_rec_len_to_disk(rec_len, blocksize);
1672                 de->inode = 0;
1673                 map++;
1674                 to += rec_len;
1675         }
1676         return (struct ext4_dir_entry_2 *) (to - rec_len);
1677 }
1678
1679 /*
1680  * Compact each dir entry in the range to the minimal rec_len.
1681  * Returns pointer to last entry in range.
1682  */
1683 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1684 {
1685         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1686         unsigned rec_len = 0;
1687
1688         prev = to = de;
1689         while ((char*)de < base + blocksize) {
1690                 next = ext4_next_entry(de, blocksize);
1691                 if (de->inode && de->name_len) {
1692                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1693                         if (de > to)
1694                                 memmove(to, de, rec_len);
1695                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1696                         prev = to;
1697                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1698                 }
1699                 de = next;
1700         }
1701         return prev;
1702 }
1703
1704 /*
1705  * Split a full leaf block to make room for a new dir entry.
1706  * Allocate a new block, and move entries so that they are approx. equally full.
1707  * Returns pointer to de in block into which the new entry will be inserted.
1708  */
1709 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1710                         struct buffer_head **bh,struct dx_frame *frame,
1711                         struct dx_hash_info *hinfo)
1712 {
1713         unsigned blocksize = dir->i_sb->s_blocksize;
1714         unsigned count, continued;
1715         struct buffer_head *bh2;
1716         ext4_lblk_t newblock;
1717         u32 hash2;
1718         struct dx_map_entry *map;
1719         char *data1 = (*bh)->b_data, *data2;
1720         unsigned split, move, size;
1721         struct ext4_dir_entry_2 *de = NULL, *de2;
1722         struct ext4_dir_entry_tail *t;
1723         int     csum_size = 0;
1724         int     err = 0, i;
1725
1726         if (ext4_has_metadata_csum(dir->i_sb))
1727                 csum_size = sizeof(struct ext4_dir_entry_tail);
1728
1729         bh2 = ext4_append(handle, dir, &newblock);
1730         if (IS_ERR(bh2)) {
1731                 brelse(*bh);
1732                 *bh = NULL;
1733                 return (struct ext4_dir_entry_2 *) bh2;
1734         }
1735
1736         BUFFER_TRACE(*bh, "get_write_access");
1737         err = ext4_journal_get_write_access(handle, *bh);
1738         if (err)
1739                 goto journal_error;
1740
1741         BUFFER_TRACE(frame->bh, "get_write_access");
1742         err = ext4_journal_get_write_access(handle, frame->bh);
1743         if (err)
1744                 goto journal_error;
1745
1746         data2 = bh2->b_data;
1747
1748         /* create map in the end of data2 block */
1749         map = (struct dx_map_entry *) (data2 + blocksize);
1750         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1751                              blocksize, hinfo, map);
1752         map -= count;
1753         dx_sort_map(map, count);
1754         /* Split the existing block in the middle, size-wise */
1755         size = 0;
1756         move = 0;
1757         for (i = count-1; i >= 0; i--) {
1758                 /* is more than half of this entry in 2nd half of the block? */
1759                 if (size + map[i].size/2 > blocksize/2)
1760                         break;
1761                 size += map[i].size;
1762                 move++;
1763         }
1764         /* map index at which we will split */
1765         split = count - move;
1766         hash2 = map[split].hash;
1767         continued = hash2 == map[split - 1].hash;
1768         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1769                         (unsigned long)dx_get_block(frame->at),
1770                                         hash2, split, count-split));
1771
1772         /* Fancy dance to stay within two buffers */
1773         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1774                               blocksize);
1775         de = dx_pack_dirents(data1, blocksize);
1776         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1777                                            (char *) de,
1778                                            blocksize);
1779         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1780                                             (char *) de2,
1781                                             blocksize);
1782         if (csum_size) {
1783                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1784                 initialize_dirent_tail(t, blocksize);
1785
1786                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1787                 initialize_dirent_tail(t, blocksize);
1788         }
1789
1790         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1791                         blocksize, 1));
1792         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1793                         blocksize, 1));
1794
1795         /* Which block gets the new entry? */
1796         if (hinfo->hash >= hash2) {
1797                 swap(*bh, bh2);
1798                 de = de2;
1799         }
1800         dx_insert_block(frame, hash2 + continued, newblock);
1801         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1802         if (err)
1803                 goto journal_error;
1804         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1805         if (err)
1806                 goto journal_error;
1807         brelse(bh2);
1808         dxtrace(dx_show_index("frame", frame->entries));
1809         return de;
1810
1811 journal_error:
1812         brelse(*bh);
1813         brelse(bh2);
1814         *bh = NULL;
1815         ext4_std_error(dir->i_sb, err);
1816         return ERR_PTR(err);
1817 }
1818
1819 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1820                       struct buffer_head *bh,
1821                       void *buf, int buf_size,
1822                       struct ext4_filename *fname,
1823                       struct ext4_dir_entry_2 **dest_de)
1824 {
1825         struct ext4_dir_entry_2 *de;
1826         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1827         int nlen, rlen;
1828         unsigned int offset = 0;
1829         char *top;
1830         int res;
1831
1832         de = (struct ext4_dir_entry_2 *)buf;
1833         top = buf + buf_size - reclen;
1834         while ((char *) de <= top) {
1835                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1836                                          buf, buf_size, offset)) {
1837                         res = -EFSCORRUPTED;
1838                         goto return_result;
1839                 }
1840                 /* Provide crypto context and crypto buffer to ext4 match */
1841                 res = ext4_match(fname, de);
1842                 if (res < 0)
1843                         goto return_result;
1844                 if (res > 0) {
1845                         res = -EEXIST;
1846                         goto return_result;
1847                 }
1848                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1849                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1850                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1851                         break;
1852                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1853                 offset += rlen;
1854         }
1855
1856         if ((char *) de > top)
1857                 res = -ENOSPC;
1858         else {
1859                 *dest_de = de;
1860                 res = 0;
1861         }
1862 return_result:
1863         return res;
1864 }
1865
1866 int ext4_insert_dentry(struct inode *dir,
1867                        struct inode *inode,
1868                        struct ext4_dir_entry_2 *de,
1869                        int buf_size,
1870                        struct ext4_filename *fname)
1871 {
1872
1873         int nlen, rlen;
1874
1875         nlen = EXT4_DIR_REC_LEN(de->name_len);
1876         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1877         if (de->inode) {
1878                 struct ext4_dir_entry_2 *de1 =
1879                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1880                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1881                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1882                 de = de1;
1883         }
1884         de->file_type = EXT4_FT_UNKNOWN;
1885         de->inode = cpu_to_le32(inode->i_ino);
1886         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1887         de->name_len = fname_len(fname);
1888         memcpy(de->name, fname_name(fname), fname_len(fname));
1889         return 0;
1890 }
1891
1892 /*
1893  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1894  * it points to a directory entry which is guaranteed to be large
1895  * enough for new directory entry.  If de is NULL, then
1896  * add_dirent_to_buf will attempt search the directory block for
1897  * space.  It will return -ENOSPC if no space is available, and -EIO
1898  * and -EEXIST if directory entry already exists.
1899  */
1900 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1901                              struct inode *dir,
1902                              struct inode *inode, struct ext4_dir_entry_2 *de,
1903                              struct buffer_head *bh)
1904 {
1905         unsigned int    blocksize = dir->i_sb->s_blocksize;
1906         int             csum_size = 0;
1907         int             err;
1908
1909         if (ext4_has_metadata_csum(inode->i_sb))
1910                 csum_size = sizeof(struct ext4_dir_entry_tail);
1911
1912         if (!de) {
1913                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1914                                         blocksize - csum_size, fname, &de);
1915                 if (err)
1916                         return err;
1917         }
1918         BUFFER_TRACE(bh, "get_write_access");
1919         err = ext4_journal_get_write_access(handle, bh);
1920         if (err) {
1921                 ext4_std_error(dir->i_sb, err);
1922                 return err;
1923         }
1924
1925         /* By now the buffer is marked for journaling. Due to crypto operations,
1926          * the following function call may fail */
1927         err = ext4_insert_dentry(dir, inode, de, blocksize, fname);
1928         if (err < 0)
1929                 return err;
1930
1931         /*
1932          * XXX shouldn't update any times until successful
1933          * completion of syscall, but too many callers depend
1934          * on this.
1935          *
1936          * XXX similarly, too many callers depend on
1937          * ext4_new_inode() setting the times, but error
1938          * recovery deletes the inode, so the worst that can
1939          * happen is that the times are slightly out of date
1940          * and/or different from the directory change time.
1941          */
1942         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1943         ext4_update_dx_flag(dir);
1944         dir->i_version++;
1945         ext4_mark_inode_dirty(handle, dir);
1946         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1947         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1948         if (err)
1949                 ext4_std_error(dir->i_sb, err);
1950         return 0;
1951 }
1952
1953 /*
1954  * This converts a one block unindexed directory to a 3 block indexed
1955  * directory, and adds the dentry to the indexed directory.
1956  */
1957 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1958                             struct inode *dir,
1959                             struct inode *inode, struct buffer_head *bh)
1960 {
1961         struct buffer_head *bh2;
1962         struct dx_root  *root;
1963         struct dx_frame frames[2], *frame;
1964         struct dx_entry *entries;
1965         struct ext4_dir_entry_2 *de, *de2;
1966         struct ext4_dir_entry_tail *t;
1967         char            *data1, *top;
1968         unsigned        len;
1969         int             retval;
1970         unsigned        blocksize;
1971         ext4_lblk_t  block;
1972         struct fake_dirent *fde;
1973         int csum_size = 0;
1974
1975         if (ext4_has_metadata_csum(inode->i_sb))
1976                 csum_size = sizeof(struct ext4_dir_entry_tail);
1977
1978         blocksize =  dir->i_sb->s_blocksize;
1979         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1980         BUFFER_TRACE(bh, "get_write_access");
1981         retval = ext4_journal_get_write_access(handle, bh);
1982         if (retval) {
1983                 ext4_std_error(dir->i_sb, retval);
1984                 brelse(bh);
1985                 return retval;
1986         }
1987         root = (struct dx_root *) bh->b_data;
1988
1989         /* The 0th block becomes the root, move the dirents out */
1990         fde = &root->dotdot;
1991         de = (struct ext4_dir_entry_2 *)((char *)fde +
1992                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1993         if ((char *) de >= (((char *) root) + blocksize)) {
1994                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1995                 brelse(bh);
1996                 return -EFSCORRUPTED;
1997         }
1998         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1999
2000         /* Allocate new block for the 0th block's dirents */
2001         bh2 = ext4_append(handle, dir, &block);
2002         if (IS_ERR(bh2)) {
2003                 brelse(bh);
2004                 return PTR_ERR(bh2);
2005         }
2006         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2007         data1 = bh2->b_data;
2008
2009         memcpy (data1, de, len);
2010         de = (struct ext4_dir_entry_2 *) data1;
2011         top = data1 + len;
2012         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2013                 de = de2;
2014         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2015                                            (char *) de,
2016                                            blocksize);
2017
2018         if (csum_size) {
2019                 t = EXT4_DIRENT_TAIL(data1, blocksize);
2020                 initialize_dirent_tail(t, blocksize);
2021         }
2022
2023         /* Initialize the root; the dot dirents already exist */
2024         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2025         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2026                                            blocksize);
2027         memset (&root->info, 0, sizeof(root->info));
2028         root->info.info_length = sizeof(root->info);
2029         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2030         entries = root->entries;
2031         dx_set_block(entries, 1);
2032         dx_set_count(entries, 1);
2033         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2034
2035         /* Initialize as for dx_probe */
2036         fname->hinfo.hash_version = root->info.hash_version;
2037         if (fname->hinfo.hash_version <= DX_HASH_TEA)
2038                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2039         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2040         ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
2041
2042         memset(frames, 0, sizeof(frames));
2043         frame = frames;
2044         frame->entries = entries;
2045         frame->at = entries;
2046         frame->bh = bh;
2047         bh = bh2;
2048
2049         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2050         if (retval)
2051                 goto out_frames;
2052         retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
2053         if (retval)
2054                 goto out_frames;
2055
2056         de = do_split(handle,dir, &bh, frame, &fname->hinfo);
2057         if (IS_ERR(de)) {
2058                 retval = PTR_ERR(de);
2059                 goto out_frames;
2060         }
2061         dx_release(frames);
2062
2063         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2064         brelse(bh);
2065         return retval;
2066 out_frames:
2067         /*
2068          * Even if the block split failed, we have to properly write
2069          * out all the changes we did so far. Otherwise we can end up
2070          * with corrupted filesystem.
2071          */
2072         ext4_mark_inode_dirty(handle, dir);
2073         dx_release(frames);
2074         return retval;
2075 }
2076
2077 /*
2078  *      ext4_add_entry()
2079  *
2080  * adds a file entry to the specified directory, using the same
2081  * semantics as ext4_find_entry(). It returns NULL if it failed.
2082  *
2083  * NOTE!! The inode part of 'de' is left at 0 - which means you
2084  * may not sleep between calling this and putting something into
2085  * the entry, as someone else might have used it while you slept.
2086  */
2087 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2088                           struct inode *inode)
2089 {
2090         struct inode *dir = d_inode(dentry->d_parent);
2091         struct buffer_head *bh = NULL;
2092         struct ext4_dir_entry_2 *de;
2093         struct ext4_dir_entry_tail *t;
2094         struct super_block *sb;
2095         struct ext4_filename fname;
2096         int     retval;
2097         int     dx_fallback=0;
2098         unsigned blocksize;
2099         ext4_lblk_t block, blocks;
2100         int     csum_size = 0;
2101
2102         if (ext4_has_metadata_csum(inode->i_sb))
2103                 csum_size = sizeof(struct ext4_dir_entry_tail);
2104
2105         sb = dir->i_sb;
2106         blocksize = sb->s_blocksize;
2107         if (!dentry->d_name.len)
2108                 return -EINVAL;
2109
2110         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2111         if (retval)
2112                 return retval;
2113
2114         if (ext4_has_inline_data(dir)) {
2115                 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2116                 if (retval < 0)
2117                         goto out;
2118                 if (retval == 1) {
2119                         retval = 0;
2120                         goto out;
2121                 }
2122         }
2123
2124         if (is_dx(dir)) {
2125                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2126                 if (!retval || (retval != ERR_BAD_DX_DIR))
2127                         goto out;
2128                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2129                 dx_fallback++;
2130                 ext4_mark_inode_dirty(handle, dir);
2131         }
2132         blocks = dir->i_size >> sb->s_blocksize_bits;
2133         for (block = 0; block < blocks; block++) {
2134                 bh = ext4_read_dirblock(dir, block, DIRENT);
2135                 if (IS_ERR(bh)) {
2136                         retval = PTR_ERR(bh);
2137                         bh = NULL;
2138                         goto out;
2139                 }
2140                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2141                                            NULL, bh);
2142                 if (retval != -ENOSPC)
2143                         goto out;
2144
2145                 if (blocks == 1 && !dx_fallback &&
2146                     ext4_has_feature_dir_index(sb)) {
2147                         retval = make_indexed_dir(handle, &fname, dir,
2148                                                   inode, bh);
2149                         bh = NULL; /* make_indexed_dir releases bh */
2150                         goto out;
2151                 }
2152                 brelse(bh);
2153         }
2154         bh = ext4_append(handle, dir, &block);
2155         if (IS_ERR(bh)) {
2156                 retval = PTR_ERR(bh);
2157                 bh = NULL;
2158                 goto out;
2159         }
2160         de = (struct ext4_dir_entry_2 *) bh->b_data;
2161         de->inode = 0;
2162         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2163
2164         if (csum_size) {
2165                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2166                 initialize_dirent_tail(t, blocksize);
2167         }
2168
2169         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2170 out:
2171         ext4_fname_free_filename(&fname);
2172         brelse(bh);
2173         if (retval == 0)
2174                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2175         return retval;
2176 }
2177
2178 /*
2179  * Returns 0 for success, or a negative error value
2180  */
2181 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2182                              struct inode *dir, struct inode *inode)
2183 {
2184         struct dx_frame frames[2], *frame;
2185         struct dx_entry *entries, *at;
2186         struct buffer_head *bh;
2187         struct super_block *sb = dir->i_sb;
2188         struct ext4_dir_entry_2 *de;
2189         int err;
2190
2191         frame = dx_probe(fname, dir, NULL, frames);
2192         if (IS_ERR(frame))
2193                 return PTR_ERR(frame);
2194         entries = frame->entries;
2195         at = frame->at;
2196         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2197         if (IS_ERR(bh)) {
2198                 err = PTR_ERR(bh);
2199                 bh = NULL;
2200                 goto cleanup;
2201         }
2202
2203         BUFFER_TRACE(bh, "get_write_access");
2204         err = ext4_journal_get_write_access(handle, bh);
2205         if (err)
2206                 goto journal_error;
2207
2208         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2209         if (err != -ENOSPC)
2210                 goto cleanup;
2211
2212         /* Block full, should compress but for now just split */
2213         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2214                        dx_get_count(entries), dx_get_limit(entries)));
2215         /* Need to split index? */
2216         if (dx_get_count(entries) == dx_get_limit(entries)) {
2217                 ext4_lblk_t newblock;
2218                 unsigned icount = dx_get_count(entries);
2219                 int levels = frame - frames;
2220                 struct dx_entry *entries2;
2221                 struct dx_node *node2;
2222                 struct buffer_head *bh2;
2223
2224                 if (levels && (dx_get_count(frames->entries) ==
2225                                dx_get_limit(frames->entries))) {
2226                         ext4_warning_inode(dir, "Directory index full!");
2227                         err = -ENOSPC;
2228                         goto cleanup;
2229                 }
2230                 bh2 = ext4_append(handle, dir, &newblock);
2231                 if (IS_ERR(bh2)) {
2232                         err = PTR_ERR(bh2);
2233                         goto cleanup;
2234                 }
2235                 node2 = (struct dx_node *)(bh2->b_data);
2236                 entries2 = node2->entries;
2237                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2238                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2239                                                            sb->s_blocksize);
2240                 BUFFER_TRACE(frame->bh, "get_write_access");
2241                 err = ext4_journal_get_write_access(handle, frame->bh);
2242                 if (err)
2243                         goto journal_error;
2244                 if (levels) {
2245                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2246                         unsigned hash2 = dx_get_hash(entries + icount1);
2247                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2248                                        icount1, icount2));
2249
2250                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2251                         err = ext4_journal_get_write_access(handle,
2252                                                              frames[0].bh);
2253                         if (err)
2254                                 goto journal_error;
2255
2256                         memcpy((char *) entries2, (char *) (entries + icount1),
2257                                icount2 * sizeof(struct dx_entry));
2258                         dx_set_count(entries, icount1);
2259                         dx_set_count(entries2, icount2);
2260                         dx_set_limit(entries2, dx_node_limit(dir));
2261
2262                         /* Which index block gets the new entry? */
2263                         if (at - entries >= icount1) {
2264                                 frame->at = at = at - entries - icount1 + entries2;
2265                                 frame->entries = entries = entries2;
2266                                 swap(frame->bh, bh2);
2267                         }
2268                         dx_insert_block(frames + 0, hash2, newblock);
2269                         dxtrace(dx_show_index("node", frames[1].entries));
2270                         dxtrace(dx_show_index("node",
2271                                ((struct dx_node *) bh2->b_data)->entries));
2272                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2273                         if (err)
2274                                 goto journal_error;
2275                         brelse (bh2);
2276                 } else {
2277                         dxtrace(printk(KERN_DEBUG
2278                                        "Creating second level index...\n"));
2279                         memcpy((char *) entries2, (char *) entries,
2280                                icount * sizeof(struct dx_entry));
2281                         dx_set_limit(entries2, dx_node_limit(dir));
2282
2283                         /* Set up root */
2284                         dx_set_count(entries, 1);
2285                         dx_set_block(entries + 0, newblock);
2286                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2287
2288                         /* Add new access path frame */
2289                         frame = frames + 1;
2290                         frame->at = at = at - entries + entries2;
2291                         frame->entries = entries = entries2;
2292                         frame->bh = bh2;
2293                         err = ext4_journal_get_write_access(handle,
2294                                                              frame->bh);
2295                         if (err)
2296                                 goto journal_error;
2297                 }
2298                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2299                 if (err) {
2300                         ext4_std_error(inode->i_sb, err);
2301                         goto cleanup;
2302                 }
2303         }
2304         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2305         if (IS_ERR(de)) {
2306                 err = PTR_ERR(de);
2307                 goto cleanup;
2308         }
2309         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2310         goto cleanup;
2311
2312 journal_error:
2313         ext4_std_error(dir->i_sb, err);
2314 cleanup:
2315         brelse(bh);
2316         dx_release(frames);
2317         return err;
2318 }
2319
2320 /*
2321  * ext4_generic_delete_entry deletes a directory entry by merging it
2322  * with the previous entry
2323  */
2324 int ext4_generic_delete_entry(handle_t *handle,
2325                               struct inode *dir,
2326                               struct ext4_dir_entry_2 *de_del,
2327                               struct buffer_head *bh,
2328                               void *entry_buf,
2329                               int buf_size,
2330                               int csum_size)
2331 {
2332         struct ext4_dir_entry_2 *de, *pde;
2333         unsigned int blocksize = dir->i_sb->s_blocksize;
2334         int i;
2335
2336         i = 0;
2337         pde = NULL;
2338         de = (struct ext4_dir_entry_2 *)entry_buf;
2339         while (i < buf_size - csum_size) {
2340                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2341                                          bh->b_data, bh->b_size, i))
2342                         return -EFSCORRUPTED;
2343                 if (de == de_del)  {
2344                         if (pde)
2345                                 pde->rec_len = ext4_rec_len_to_disk(
2346                                         ext4_rec_len_from_disk(pde->rec_len,
2347                                                                blocksize) +
2348                                         ext4_rec_len_from_disk(de->rec_len,
2349                                                                blocksize),
2350                                         blocksize);
2351                         else
2352                                 de->inode = 0;
2353                         dir->i_version++;
2354                         return 0;
2355                 }
2356                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2357                 pde = de;
2358                 de = ext4_next_entry(de, blocksize);
2359         }
2360         return -ENOENT;
2361 }
2362
2363 static int ext4_delete_entry(handle_t *handle,
2364                              struct inode *dir,
2365                              struct ext4_dir_entry_2 *de_del,
2366                              struct buffer_head *bh)
2367 {
2368         int err, csum_size = 0;
2369
2370         if (ext4_has_inline_data(dir)) {
2371                 int has_inline_data = 1;
2372                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2373                                                &has_inline_data);
2374                 if (has_inline_data)
2375                         return err;
2376         }
2377
2378         if (ext4_has_metadata_csum(dir->i_sb))
2379                 csum_size = sizeof(struct ext4_dir_entry_tail);
2380
2381         BUFFER_TRACE(bh, "get_write_access");
2382         err = ext4_journal_get_write_access(handle, bh);
2383         if (unlikely(err))
2384                 goto out;
2385
2386         err = ext4_generic_delete_entry(handle, dir, de_del,
2387                                         bh, bh->b_data,
2388                                         dir->i_sb->s_blocksize, csum_size);
2389         if (err)
2390                 goto out;
2391
2392         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2393         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2394         if (unlikely(err))
2395                 goto out;
2396
2397         return 0;
2398 out:
2399         if (err != -ENOENT)
2400                 ext4_std_error(dir->i_sb, err);
2401         return err;
2402 }
2403
2404 /*
2405  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2406  * since this indicates that nlinks count was previously 1.
2407  */
2408 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2409 {
2410         inc_nlink(inode);
2411         if (is_dx(inode) && inode->i_nlink > 1) {
2412                 /* limit is 16-bit i_links_count */
2413                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2414                         set_nlink(inode, 1);
2415                         ext4_set_feature_dir_nlink(inode->i_sb);
2416                 }
2417         }
2418 }
2419
2420 /*
2421  * If a directory had nlink == 1, then we should let it be 1. This indicates
2422  * directory has >EXT4_LINK_MAX subdirs.
2423  */
2424 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2425 {
2426         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2427                 drop_nlink(inode);
2428 }
2429
2430
2431 static int ext4_add_nondir(handle_t *handle,
2432                 struct dentry *dentry, struct inode *inode)
2433 {
2434         int err = ext4_add_entry(handle, dentry, inode);
2435         if (!err) {
2436                 ext4_mark_inode_dirty(handle, inode);
2437                 unlock_new_inode(inode);
2438                 d_instantiate(dentry, inode);
2439                 return 0;
2440         }
2441         drop_nlink(inode);
2442         unlock_new_inode(inode);
2443         iput(inode);
2444         return err;
2445 }
2446
2447 /*
2448  * By the time this is called, we already have created
2449  * the directory cache entry for the new file, but it
2450  * is so far negative - it has no inode.
2451  *
2452  * If the create succeeds, we fill in the inode information
2453  * with d_instantiate().
2454  */
2455 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2456                        bool excl)
2457 {
2458         handle_t *handle;
2459         struct inode *inode;
2460         int err, credits, retries = 0;
2461
2462         err = dquot_initialize(dir);
2463         if (err)
2464                 return err;
2465
2466         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2467                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2468 retry:
2469         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2470                                             NULL, EXT4_HT_DIR, credits);
2471         handle = ext4_journal_current_handle();
2472         err = PTR_ERR(inode);
2473         if (!IS_ERR(inode)) {
2474                 inode->i_op = &ext4_file_inode_operations;
2475                 inode->i_fop = &ext4_file_operations;
2476                 ext4_set_aops(inode);
2477                 err = ext4_add_nondir(handle, dentry, inode);
2478                 if (!err && IS_DIRSYNC(dir))
2479                         ext4_handle_sync(handle);
2480         }
2481         if (handle)
2482                 ext4_journal_stop(handle);
2483         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2484                 goto retry;
2485         return err;
2486 }
2487
2488 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2489                       umode_t mode, dev_t rdev)
2490 {
2491         handle_t *handle;
2492         struct inode *inode;
2493         int err, credits, retries = 0;
2494
2495         err = dquot_initialize(dir);
2496         if (err)
2497                 return err;
2498
2499         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2500                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2501 retry:
2502         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2503                                             NULL, EXT4_HT_DIR, credits);
2504         handle = ext4_journal_current_handle();
2505         err = PTR_ERR(inode);
2506         if (!IS_ERR(inode)) {
2507                 init_special_inode(inode, inode->i_mode, rdev);
2508                 inode->i_op = &ext4_special_inode_operations;
2509                 err = ext4_add_nondir(handle, dentry, inode);
2510                 if (!err && IS_DIRSYNC(dir))
2511                         ext4_handle_sync(handle);
2512         }
2513         if (handle)
2514                 ext4_journal_stop(handle);
2515         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2516                 goto retry;
2517         return err;
2518 }
2519
2520 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2521 {
2522         handle_t *handle;
2523         struct inode *inode;
2524         int err, retries = 0;
2525
2526         err = dquot_initialize(dir);
2527         if (err)
2528                 return err;
2529
2530 retry:
2531         inode = ext4_new_inode_start_handle(dir, mode,
2532                                             NULL, 0, NULL,
2533                                             EXT4_HT_DIR,
2534                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2535                           4 + EXT4_XATTR_TRANS_BLOCKS);
2536         handle = ext4_journal_current_handle();
2537         err = PTR_ERR(inode);
2538         if (!IS_ERR(inode)) {
2539                 inode->i_op = &ext4_file_inode_operations;
2540                 inode->i_fop = &ext4_file_operations;
2541                 ext4_set_aops(inode);
2542                 d_tmpfile(dentry, inode);
2543                 err = ext4_orphan_add(handle, inode);
2544                 if (err)
2545                         goto err_unlock_inode;
2546                 mark_inode_dirty(inode);
2547                 unlock_new_inode(inode);
2548         }
2549         if (handle)
2550                 ext4_journal_stop(handle);
2551         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2552                 goto retry;
2553         return err;
2554 err_unlock_inode:
2555         ext4_journal_stop(handle);
2556         unlock_new_inode(inode);
2557         return err;
2558 }
2559
2560 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2561                           struct ext4_dir_entry_2 *de,
2562                           int blocksize, int csum_size,
2563                           unsigned int parent_ino, int dotdot_real_len)
2564 {
2565         de->inode = cpu_to_le32(inode->i_ino);
2566         de->name_len = 1;
2567         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2568                                            blocksize);
2569         strcpy(de->name, ".");
2570         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2571
2572         de = ext4_next_entry(de, blocksize);
2573         de->inode = cpu_to_le32(parent_ino);
2574         de->name_len = 2;
2575         if (!dotdot_real_len)
2576                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2577                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2578                                         blocksize);
2579         else
2580                 de->rec_len = ext4_rec_len_to_disk(
2581                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2582         strcpy(de->name, "..");
2583         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2584
2585         return ext4_next_entry(de, blocksize);
2586 }
2587
2588 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2589                              struct inode *inode)
2590 {
2591         struct buffer_head *dir_block = NULL;
2592         struct ext4_dir_entry_2 *de;
2593         struct ext4_dir_entry_tail *t;
2594         ext4_lblk_t block = 0;
2595         unsigned int blocksize = dir->i_sb->s_blocksize;
2596         int csum_size = 0;
2597         int err;
2598
2599         if (ext4_has_metadata_csum(dir->i_sb))
2600                 csum_size = sizeof(struct ext4_dir_entry_tail);
2601
2602         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2603                 err = ext4_try_create_inline_dir(handle, dir, inode);
2604                 if (err < 0 && err != -ENOSPC)
2605                         goto out;
2606                 if (!err)
2607                         goto out;
2608         }
2609
2610         inode->i_size = 0;
2611         dir_block = ext4_append(handle, inode, &block);
2612         if (IS_ERR(dir_block))
2613                 return PTR_ERR(dir_block);
2614         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2615         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2616         set_nlink(inode, 2);
2617         if (csum_size) {
2618                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2619                 initialize_dirent_tail(t, blocksize);
2620         }
2621
2622         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2623         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2624         if (err)
2625                 goto out;
2626         set_buffer_verified(dir_block);
2627 out:
2628         brelse(dir_block);
2629         return err;
2630 }
2631
2632 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2633 {
2634         handle_t *handle;
2635         struct inode *inode;
2636         int err, credits, retries = 0;
2637
2638         if (EXT4_DIR_LINK_MAX(dir))
2639                 return -EMLINK;
2640
2641         err = dquot_initialize(dir);
2642         if (err)
2643                 return err;
2644
2645         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2646                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2647 retry:
2648         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2649                                             &dentry->d_name,
2650                                             0, NULL, EXT4_HT_DIR, credits);
2651         handle = ext4_journal_current_handle();
2652         err = PTR_ERR(inode);
2653         if (IS_ERR(inode))
2654                 goto out_stop;
2655
2656         inode->i_op = &ext4_dir_inode_operations;
2657         inode->i_fop = &ext4_dir_operations;
2658         err = ext4_init_new_dir(handle, dir, inode);
2659         if (err)
2660                 goto out_clear_inode;
2661         err = ext4_mark_inode_dirty(handle, inode);
2662         if (!err)
2663                 err = ext4_add_entry(handle, dentry, inode);
2664         if (err) {
2665 out_clear_inode:
2666                 clear_nlink(inode);
2667                 unlock_new_inode(inode);
2668                 ext4_mark_inode_dirty(handle, inode);
2669                 iput(inode);
2670                 goto out_stop;
2671         }
2672         ext4_inc_count(handle, dir);
2673         ext4_update_dx_flag(dir);
2674         err = ext4_mark_inode_dirty(handle, dir);
2675         if (err)
2676                 goto out_clear_inode;
2677         unlock_new_inode(inode);
2678         d_instantiate(dentry, inode);
2679         if (IS_DIRSYNC(dir))
2680                 ext4_handle_sync(handle);
2681
2682 out_stop:
2683         if (handle)
2684                 ext4_journal_stop(handle);
2685         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2686                 goto retry;
2687         return err;
2688 }
2689
2690 /*
2691  * routine to check that the specified directory is empty (for rmdir)
2692  */
2693 int ext4_empty_dir(struct inode *inode)
2694 {
2695         unsigned int offset;
2696         struct buffer_head *bh;
2697         struct ext4_dir_entry_2 *de, *de1;
2698         struct super_block *sb;
2699         int err = 0;
2700
2701         if (ext4_has_inline_data(inode)) {
2702                 int has_inline_data = 1;
2703
2704                 err = empty_inline_dir(inode, &has_inline_data);
2705                 if (has_inline_data)
2706                         return err;
2707         }
2708
2709         sb = inode->i_sb;
2710         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2711                 EXT4_ERROR_INODE(inode, "invalid size");
2712                 return 1;
2713         }
2714         bh = ext4_read_dirblock(inode, 0, EITHER);
2715         if (IS_ERR(bh))
2716                 return 1;
2717
2718         de = (struct ext4_dir_entry_2 *) bh->b_data;
2719         de1 = ext4_next_entry(de, sb->s_blocksize);
2720         if (le32_to_cpu(de->inode) != inode->i_ino ||
2721                         le32_to_cpu(de1->inode) == 0 ||
2722                         strcmp(".", de->name) || strcmp("..", de1->name)) {
2723                 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2724                 brelse(bh);
2725                 return 1;
2726         }
2727         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2728                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2729         de = ext4_next_entry(de1, sb->s_blocksize);
2730         while (offset < inode->i_size) {
2731                 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2732                         unsigned int lblock;
2733                         err = 0;
2734                         brelse(bh);
2735                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2736                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2737                         if (IS_ERR(bh))
2738                                 return 1;
2739                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2740                 }
2741                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2742                                          bh->b_data, bh->b_size, offset)) {
2743                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2744                                                          sb->s_blocksize);
2745                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2746                         continue;
2747                 }
2748                 if (le32_to_cpu(de->inode)) {
2749                         brelse(bh);
2750                         return 0;
2751                 }
2752                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2753                 de = ext4_next_entry(de, sb->s_blocksize);
2754         }
2755         brelse(bh);
2756         return 1;
2757 }
2758
2759 /*
2760  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2761  * such inodes, starting at the superblock, in case we crash before the
2762  * file is closed/deleted, or in case the inode truncate spans multiple
2763  * transactions and the last transaction is not recovered after a crash.
2764  *
2765  * At filesystem recovery time, we walk this list deleting unlinked
2766  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2767  *
2768  * Orphan list manipulation functions must be called under i_mutex unless
2769  * we are just creating the inode or deleting it.
2770  */
2771 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2772 {
2773         struct super_block *sb = inode->i_sb;
2774         struct ext4_sb_info *sbi = EXT4_SB(sb);
2775         struct ext4_iloc iloc;
2776         int err = 0, rc;
2777         bool dirty = false;
2778
2779         if (!sbi->s_journal || is_bad_inode(inode))
2780                 return 0;
2781
2782         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2783                      !inode_is_locked(inode));
2784         /*
2785          * Exit early if inode already is on orphan list. This is a big speedup
2786          * since we don't have to contend on the global s_orphan_lock.
2787          */
2788         if (!list_empty(&EXT4_I(inode)->i_orphan))
2789                 return 0;
2790
2791         /*
2792          * Orphan handling is only valid for files with data blocks
2793          * being truncated, or files being unlinked. Note that we either
2794          * hold i_mutex, or the inode can not be referenced from outside,
2795          * so i_nlink should not be bumped due to race
2796          */
2797         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2798                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2799
2800         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2801         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2802         if (err)
2803                 goto out;
2804
2805         err = ext4_reserve_inode_write(handle, inode, &iloc);
2806         if (err)
2807                 goto out;
2808
2809         mutex_lock(&sbi->s_orphan_lock);
2810         /*
2811          * Due to previous errors inode may be already a part of on-disk
2812          * orphan list. If so skip on-disk list modification.
2813          */
2814         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2815             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2816                 /* Insert this inode at the head of the on-disk orphan list */
2817                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2818                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2819                 dirty = true;
2820         }
2821         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2822         mutex_unlock(&sbi->s_orphan_lock);
2823
2824         if (dirty) {
2825                 err = ext4_handle_dirty_super(handle, sb);
2826                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2827                 if (!err)
2828                         err = rc;
2829                 if (err) {
2830                         /*
2831                          * We have to remove inode from in-memory list if
2832                          * addition to on disk orphan list failed. Stray orphan
2833                          * list entries can cause panics at unmount time.
2834                          */
2835                         mutex_lock(&sbi->s_orphan_lock);
2836                         list_del(&EXT4_I(inode)->i_orphan);
2837                         mutex_unlock(&sbi->s_orphan_lock);
2838                 }
2839         }
2840         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2841         jbd_debug(4, "orphan inode %lu will point to %d\n",
2842                         inode->i_ino, NEXT_ORPHAN(inode));
2843 out:
2844         ext4_std_error(sb, err);
2845         return err;
2846 }
2847
2848 /*
2849  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2850  * of such inodes stored on disk, because it is finally being cleaned up.
2851  */
2852 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2853 {
2854         struct list_head *prev;
2855         struct ext4_inode_info *ei = EXT4_I(inode);
2856         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2857         __u32 ino_next;
2858         struct ext4_iloc iloc;
2859         int err = 0;
2860
2861         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2862                 return 0;
2863
2864         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2865                      !inode_is_locked(inode));
2866         /* Do this quick check before taking global s_orphan_lock. */
2867         if (list_empty(&ei->i_orphan))
2868                 return 0;
2869
2870         if (handle) {
2871                 /* Grab inode buffer early before taking global s_orphan_lock */
2872                 err = ext4_reserve_inode_write(handle, inode, &iloc);
2873         }
2874
2875         mutex_lock(&sbi->s_orphan_lock);
2876         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2877
2878         prev = ei->i_orphan.prev;
2879         list_del_init(&ei->i_orphan);
2880
2881         /* If we're on an error path, we may not have a valid
2882          * transaction handle with which to update the orphan list on
2883          * disk, but we still need to remove the inode from the linked
2884          * list in memory. */
2885         if (!handle || err) {
2886                 mutex_unlock(&sbi->s_orphan_lock);
2887                 goto out_err;
2888         }
2889
2890         ino_next = NEXT_ORPHAN(inode);
2891         if (prev == &sbi->s_orphan) {
2892                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2893                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2894                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2895                 if (err) {
2896                         mutex_unlock(&sbi->s_orphan_lock);
2897                         goto out_brelse;
2898                 }
2899                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2900                 mutex_unlock(&sbi->s_orphan_lock);
2901                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2902         } else {
2903                 struct ext4_iloc iloc2;
2904                 struct inode *i_prev =
2905                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2906
2907                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2908                           i_prev->i_ino, ino_next);
2909                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2910                 if (err) {
2911                         mutex_unlock(&sbi->s_orphan_lock);
2912                         goto out_brelse;
2913                 }
2914                 NEXT_ORPHAN(i_prev) = ino_next;
2915                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2916                 mutex_unlock(&sbi->s_orphan_lock);
2917         }
2918         if (err)
2919                 goto out_brelse;
2920         NEXT_ORPHAN(inode) = 0;
2921         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2922 out_err:
2923         ext4_std_error(inode->i_sb, err);
2924         return err;
2925
2926 out_brelse:
2927         brelse(iloc.bh);
2928         goto out_err;
2929 }
2930
2931 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2932 {
2933         int retval;
2934         struct inode *inode;
2935         struct buffer_head *bh;
2936         struct ext4_dir_entry_2 *de;
2937         handle_t *handle = NULL;
2938
2939         /* Initialize quotas before so that eventual writes go in
2940          * separate transaction */
2941         retval = dquot_initialize(dir);
2942         if (retval)
2943                 return retval;
2944         retval = dquot_initialize(d_inode(dentry));
2945         if (retval)
2946                 return retval;
2947
2948         retval = -ENOENT;
2949         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2950         if (IS_ERR(bh))
2951                 return PTR_ERR(bh);
2952         if (!bh)
2953                 goto end_rmdir;
2954
2955         inode = d_inode(dentry);
2956
2957         retval = -EFSCORRUPTED;
2958         if (le32_to_cpu(de->inode) != inode->i_ino)
2959                 goto end_rmdir;
2960
2961         retval = -ENOTEMPTY;
2962         if (!ext4_empty_dir(inode))
2963                 goto end_rmdir;
2964
2965         handle = ext4_journal_start(dir, EXT4_HT_DIR,
2966                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2967         if (IS_ERR(handle)) {
2968                 retval = PTR_ERR(handle);
2969                 handle = NULL;
2970                 goto end_rmdir;
2971         }
2972
2973         if (IS_DIRSYNC(dir))
2974                 ext4_handle_sync(handle);
2975
2976         retval = ext4_delete_entry(handle, dir, de, bh);
2977         if (retval)
2978                 goto end_rmdir;
2979         if (!EXT4_DIR_LINK_EMPTY(inode))
2980                 ext4_warning_inode(inode,
2981                              "empty directory '%.*s' has too many links (%u)",
2982                              dentry->d_name.len, dentry->d_name.name,
2983                              inode->i_nlink);
2984         inode->i_version++;
2985         clear_nlink(inode);
2986         /* There's no need to set i_disksize: the fact that i_nlink is
2987          * zero will ensure that the right thing happens during any
2988          * recovery. */
2989         inode->i_size = 0;
2990         ext4_orphan_add(handle, inode);
2991         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2992         ext4_mark_inode_dirty(handle, inode);
2993         ext4_dec_count(handle, dir);
2994         ext4_update_dx_flag(dir);
2995         ext4_mark_inode_dirty(handle, dir);
2996
2997 end_rmdir:
2998         brelse(bh);
2999         if (handle)
3000                 ext4_journal_stop(handle);
3001         return retval;
3002 }
3003
3004 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3005 {
3006         int retval;
3007         struct inode *inode;
3008         struct buffer_head *bh;
3009         struct ext4_dir_entry_2 *de;
3010         handle_t *handle = NULL;
3011
3012         trace_ext4_unlink_enter(dir, dentry);
3013         /* Initialize quotas before so that eventual writes go
3014          * in separate transaction */
3015         retval = dquot_initialize(dir);
3016         if (retval)
3017                 return retval;
3018         retval = dquot_initialize(d_inode(dentry));
3019         if (retval)
3020                 return retval;
3021
3022         retval = -ENOENT;
3023         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3024         if (IS_ERR(bh))
3025                 return PTR_ERR(bh);
3026         if (!bh)
3027                 goto end_unlink;
3028
3029         inode = d_inode(dentry);
3030
3031         retval = -EFSCORRUPTED;
3032         if (le32_to_cpu(de->inode) != inode->i_ino)
3033                 goto end_unlink;
3034
3035         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3036                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3037         if (IS_ERR(handle)) {
3038                 retval = PTR_ERR(handle);
3039                 handle = NULL;
3040                 goto end_unlink;
3041         }
3042
3043         if (IS_DIRSYNC(dir))
3044                 ext4_handle_sync(handle);
3045
3046         if (inode->i_nlink == 0) {
3047                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3048                                    dentry->d_name.len, dentry->d_name.name);
3049                 set_nlink(inode, 1);
3050         }
3051         retval = ext4_delete_entry(handle, dir, de, bh);
3052         if (retval)
3053                 goto end_unlink;
3054         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3055         ext4_update_dx_flag(dir);
3056         ext4_mark_inode_dirty(handle, dir);
3057         drop_nlink(inode);
3058         if (!inode->i_nlink)
3059                 ext4_orphan_add(handle, inode);
3060         inode->i_ctime = ext4_current_time(inode);
3061         ext4_mark_inode_dirty(handle, inode);
3062
3063 end_unlink:
3064         brelse(bh);
3065         if (handle)
3066                 ext4_journal_stop(handle);
3067         trace_ext4_unlink_exit(dentry, retval);
3068         return retval;
3069 }
3070
3071 static int ext4_symlink(struct inode *dir,
3072                         struct dentry *dentry, const char *symname)
3073 {
3074         handle_t *handle;
3075         struct inode *inode;
3076         int err, len = strlen(symname);
3077         int credits;
3078         bool encryption_required;
3079         struct ext4_str disk_link;
3080         struct ext4_encrypted_symlink_data *sd = NULL;
3081
3082         disk_link.len = len + 1;
3083         disk_link.name = (char *) symname;
3084
3085         encryption_required = (ext4_encrypted_inode(dir) ||
3086                                DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3087         if (encryption_required) {
3088                 err = ext4_get_encryption_info(dir);
3089                 if (err)
3090                         return err;
3091                 if (ext4_encryption_info(dir) == NULL)
3092                         return -EPERM;
3093                 disk_link.len = (ext4_fname_encrypted_size(dir, len) +
3094                                  sizeof(struct ext4_encrypted_symlink_data));
3095                 sd = kzalloc(disk_link.len, GFP_KERNEL);
3096                 if (!sd)
3097                         return -ENOMEM;
3098         }
3099
3100         if (disk_link.len > dir->i_sb->s_blocksize) {
3101                 err = -ENAMETOOLONG;
3102                 goto err_free_sd;
3103         }
3104
3105         err = dquot_initialize(dir);
3106         if (err)
3107                 goto err_free_sd;
3108
3109         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3110                 /*
3111                  * For non-fast symlinks, we just allocate inode and put it on
3112                  * orphan list in the first transaction => we need bitmap,
3113                  * group descriptor, sb, inode block, quota blocks, and
3114                  * possibly selinux xattr blocks.
3115                  */
3116                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3117                           EXT4_XATTR_TRANS_BLOCKS;
3118         } else {
3119                 /*
3120                  * Fast symlink. We have to add entry to directory
3121                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3122                  * allocate new inode (bitmap, group descriptor, inode block,
3123                  * quota blocks, sb is already counted in previous macros).
3124                  */
3125                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3126                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3127         }
3128
3129         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3130                                             &dentry->d_name, 0, NULL,
3131                                             EXT4_HT_DIR, credits);
3132         handle = ext4_journal_current_handle();
3133         if (IS_ERR(inode)) {
3134                 if (handle)
3135                         ext4_journal_stop(handle);
3136                 err = PTR_ERR(inode);
3137                 goto err_free_sd;
3138         }
3139
3140         if (encryption_required) {
3141                 struct qstr istr;
3142                 struct ext4_str ostr;
3143
3144                 istr.name = (const unsigned char *) symname;
3145                 istr.len = len;
3146                 ostr.name = sd->encrypted_path;
3147                 ostr.len = disk_link.len;
3148                 err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
3149                 if (err < 0)
3150                         goto err_drop_inode;
3151                 sd->len = cpu_to_le16(ostr.len);
3152                 disk_link.name = (char *) sd;
3153                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3154         }
3155
3156         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3157                 if (!encryption_required)
3158                         inode->i_op = &ext4_symlink_inode_operations;
3159                 inode_nohighmem(inode);
3160                 ext4_set_aops(inode);
3161                 /*
3162                  * We cannot call page_symlink() with transaction started
3163                  * because it calls into ext4_write_begin() which can wait
3164                  * for transaction commit if we are running out of space
3165                  * and thus we deadlock. So we have to stop transaction now
3166                  * and restart it when symlink contents is written.
3167                  *
3168                  * To keep fs consistent in case of crash, we have to put inode
3169                  * to orphan list in the mean time.
3170                  */
3171                 drop_nlink(inode);
3172                 err = ext4_orphan_add(handle, inode);
3173                 ext4_journal_stop(handle);
3174                 handle = NULL;
3175                 if (err)
3176                         goto err_drop_inode;
3177                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3178                 if (err)
3179                         goto err_drop_inode;
3180                 /*
3181                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3182                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3183                  */
3184                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3185                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3186                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3187                 if (IS_ERR(handle)) {
3188                         err = PTR_ERR(handle);
3189                         handle = NULL;
3190                         goto err_drop_inode;
3191                 }
3192                 set_nlink(inode, 1);
3193                 err = ext4_orphan_del(handle, inode);
3194                 if (err)
3195                         goto err_drop_inode;
3196         } else {
3197                 /* clear the extent format for fast symlink */
3198                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3199                 if (!encryption_required) {
3200                         inode->i_op = &ext4_fast_symlink_inode_operations;
3201                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3202                 }
3203                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3204                        disk_link.len);
3205                 inode->i_size = disk_link.len - 1;
3206         }
3207         EXT4_I(inode)->i_disksize = inode->i_size;
3208         err = ext4_add_nondir(handle, dentry, inode);
3209         if (!err && IS_DIRSYNC(dir))
3210                 ext4_handle_sync(handle);
3211
3212         if (handle)
3213                 ext4_journal_stop(handle);
3214         kfree(sd);
3215         return err;
3216 err_drop_inode:
3217         if (handle)
3218                 ext4_journal_stop(handle);
3219         clear_nlink(inode);
3220         unlock_new_inode(inode);
3221         iput(inode);
3222 err_free_sd:
3223         kfree(sd);
3224         return err;
3225 }
3226
3227 static int ext4_link(struct dentry *old_dentry,
3228                      struct inode *dir, struct dentry *dentry)
3229 {
3230         handle_t *handle;
3231         struct inode *inode = d_inode(old_dentry);
3232         int err, retries = 0;
3233
3234         if (inode->i_nlink >= EXT4_LINK_MAX)
3235                 return -EMLINK;
3236         if (ext4_encrypted_inode(dir) &&
3237             !ext4_is_child_context_consistent_with_parent(dir, inode))
3238                 return -EPERM;
3239
3240        if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3241            (!projid_eq(EXT4_I(dir)->i_projid,
3242                        EXT4_I(old_dentry->d_inode)->i_projid)))
3243                 return -EXDEV;
3244
3245         err = dquot_initialize(dir);
3246         if (err)
3247                 return err;
3248
3249 retry:
3250         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3251                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3252                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3253         if (IS_ERR(handle))
3254                 return PTR_ERR(handle);
3255
3256         if (IS_DIRSYNC(dir))
3257                 ext4_handle_sync(handle);
3258
3259         inode->i_ctime = ext4_current_time(inode);
3260         ext4_inc_count(handle, inode);
3261         ihold(inode);
3262
3263         err = ext4_add_entry(handle, dentry, inode);
3264         if (!err) {
3265                 ext4_mark_inode_dirty(handle, inode);
3266                 /* this can happen only for tmpfile being
3267                  * linked the first time
3268                  */
3269                 if (inode->i_nlink == 1)
3270                         ext4_orphan_del(handle, inode);
3271                 d_instantiate(dentry, inode);
3272         } else {
3273                 drop_nlink(inode);
3274                 iput(inode);
3275         }
3276         ext4_journal_stop(handle);
3277         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3278                 goto retry;
3279         return err;
3280 }
3281
3282
3283 /*
3284  * Try to find buffer head where contains the parent block.
3285  * It should be the inode block if it is inlined or the 1st block
3286  * if it is a normal dir.
3287  */
3288 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3289                                         struct inode *inode,
3290                                         int *retval,
3291                                         struct ext4_dir_entry_2 **parent_de,
3292                                         int *inlined)
3293 {
3294         struct buffer_head *bh;
3295
3296         if (!ext4_has_inline_data(inode)) {
3297                 bh = ext4_read_dirblock(inode, 0, EITHER);
3298                 if (IS_ERR(bh)) {
3299                         *retval = PTR_ERR(bh);
3300                         return NULL;
3301                 }
3302                 *parent_de = ext4_next_entry(
3303                                         (struct ext4_dir_entry_2 *)bh->b_data,
3304                                         inode->i_sb->s_blocksize);
3305                 return bh;
3306         }
3307
3308         *inlined = 1;
3309         return ext4_get_first_inline_block(inode, parent_de, retval);
3310 }
3311
3312 struct ext4_renament {
3313         struct inode *dir;
3314         struct dentry *dentry;
3315         struct inode *inode;
3316         bool is_dir;
3317         int dir_nlink_delta;
3318
3319         /* entry for "dentry" */
3320         struct buffer_head *bh;
3321         struct ext4_dir_entry_2 *de;
3322         int inlined;
3323
3324         /* entry for ".." in inode if it's a directory */
3325         struct buffer_head *dir_bh;
3326         struct ext4_dir_entry_2 *parent_de;
3327         int dir_inlined;
3328 };
3329
3330 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3331 {
3332         int retval;
3333
3334         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3335                                               &retval, &ent->parent_de,
3336                                               &ent->dir_inlined);
3337         if (!ent->dir_bh)
3338                 return retval;
3339         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3340                 return -EFSCORRUPTED;
3341         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3342         return ext4_journal_get_write_access(handle, ent->dir_bh);
3343 }
3344
3345 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3346                                   unsigned dir_ino)
3347 {
3348         int retval;
3349
3350         ent->parent_de->inode = cpu_to_le32(dir_ino);
3351         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3352         if (!ent->dir_inlined) {
3353                 if (is_dx(ent->inode)) {
3354                         retval = ext4_handle_dirty_dx_node(handle,
3355                                                            ent->inode,
3356                                                            ent->dir_bh);
3357                 } else {
3358                         retval = ext4_handle_dirty_dirent_node(handle,
3359                                                                ent->inode,
3360                                                                ent->dir_bh);
3361                 }
3362         } else {
3363                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3364         }
3365         if (retval) {
3366                 ext4_std_error(ent->dir->i_sb, retval);
3367                 return retval;
3368         }
3369         return 0;
3370 }
3371
3372 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3373                        unsigned ino, unsigned file_type)
3374 {
3375         int retval;
3376
3377         BUFFER_TRACE(ent->bh, "get write access");
3378         retval = ext4_journal_get_write_access(handle, ent->bh);
3379         if (retval)
3380                 return retval;
3381         ent->de->inode = cpu_to_le32(ino);
3382         if (ext4_has_feature_filetype(ent->dir->i_sb))
3383                 ent->de->file_type = file_type;
3384         ent->dir->i_version++;
3385         ent->dir->i_ctime = ent->dir->i_mtime =
3386                 ext4_current_time(ent->dir);
3387         ext4_mark_inode_dirty(handle, ent->dir);
3388         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3389         if (!ent->inlined) {
3390                 retval = ext4_handle_dirty_dirent_node(handle,
3391                                                        ent->dir, ent->bh);
3392                 if (unlikely(retval)) {
3393                         ext4_std_error(ent->dir->i_sb, retval);
3394                         return retval;
3395                 }
3396         }
3397         brelse(ent->bh);
3398         ent->bh = NULL;
3399
3400         return 0;
3401 }
3402
3403 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3404                                   const struct qstr *d_name)
3405 {
3406         int retval = -ENOENT;
3407         struct buffer_head *bh;
3408         struct ext4_dir_entry_2 *de;
3409
3410         bh = ext4_find_entry(dir, d_name, &de, NULL);
3411         if (IS_ERR(bh))
3412                 return PTR_ERR(bh);
3413         if (bh) {
3414                 retval = ext4_delete_entry(handle, dir, de, bh);
3415                 brelse(bh);
3416         }
3417         return retval;
3418 }
3419
3420 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3421                                int force_reread)
3422 {
3423         int retval;
3424         /*
3425          * ent->de could have moved from under us during htree split, so make
3426          * sure that we are deleting the right entry.  We might also be pointing
3427          * to a stale entry in the unused part of ent->bh so just checking inum
3428          * and the name isn't enough.
3429          */
3430         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3431             ent->de->name_len != ent->dentry->d_name.len ||
3432             strncmp(ent->de->name, ent->dentry->d_name.name,
3433                     ent->de->name_len) ||
3434             force_reread) {
3435                 retval = ext4_find_delete_entry(handle, ent->dir,
3436                                                 &ent->dentry->d_name);
3437         } else {
3438                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3439                 if (retval == -ENOENT) {
3440                         retval = ext4_find_delete_entry(handle, ent->dir,
3441                                                         &ent->dentry->d_name);
3442                 }
3443         }
3444
3445         if (retval) {
3446                 ext4_warning_inode(ent->dir,
3447                                    "Deleting old file: nlink %d, error=%d",
3448                                    ent->dir->i_nlink, retval);
3449         }
3450 }
3451
3452 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3453 {
3454         if (ent->dir_nlink_delta) {
3455                 if (ent->dir_nlink_delta == -1)
3456                         ext4_dec_count(handle, ent->dir);
3457                 else
3458                         ext4_inc_count(handle, ent->dir);
3459                 ext4_mark_inode_dirty(handle, ent->dir);
3460         }
3461 }
3462
3463 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3464                                               int credits, handle_t **h)
3465 {
3466         struct inode *wh;
3467         handle_t *handle;
3468         int retries = 0;
3469
3470         /*
3471          * for inode block, sb block, group summaries,
3472          * and inode bitmap
3473          */
3474         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3475                     EXT4_XATTR_TRANS_BLOCKS + 4);
3476 retry:
3477         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3478                                          &ent->dentry->d_name, 0, NULL,
3479                                          EXT4_HT_DIR, credits);
3480
3481         handle = ext4_journal_current_handle();
3482         if (IS_ERR(wh)) {
3483                 if (handle)
3484                         ext4_journal_stop(handle);
3485                 if (PTR_ERR(wh) == -ENOSPC &&
3486                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3487                         goto retry;
3488         } else {
3489                 *h = handle;
3490                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3491                 wh->i_op = &ext4_special_inode_operations;
3492         }
3493         return wh;
3494 }
3495
3496 /*
3497  * Anybody can rename anything with this: the permission checks are left to the
3498  * higher-level routines.
3499  *
3500  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3501  * while new_{dentry,inode) refers to the destination dentry/inode
3502  * This comes from rename(const char *oldpath, const char *newpath)
3503  */
3504 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3505                        struct inode *new_dir, struct dentry *new_dentry,
3506                        unsigned int flags)
3507 {
3508         handle_t *handle = NULL;
3509         struct ext4_renament old = {
3510                 .dir = old_dir,
3511                 .dentry = old_dentry,
3512                 .inode = d_inode(old_dentry),
3513         };
3514         struct ext4_renament new = {
3515                 .dir = new_dir,
3516                 .dentry = new_dentry,
3517                 .inode = d_inode(new_dentry),
3518         };
3519         int force_reread;
3520         int retval;
3521         struct inode *whiteout = NULL;
3522         int credits;
3523         u8 old_file_type;
3524
3525         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3526             (!projid_eq(EXT4_I(new_dir)->i_projid,
3527                         EXT4_I(old_dentry->d_inode)->i_projid)))
3528                 return -EXDEV;
3529
3530         retval = dquot_initialize(old.dir);
3531         if (retval)
3532                 return retval;
3533         retval = dquot_initialize(new.dir);
3534         if (retval)
3535                 return retval;
3536
3537         /* Initialize quotas before so that eventual writes go
3538          * in separate transaction */
3539         if (new.inode) {
3540                 retval = dquot_initialize(new.inode);
3541                 if (retval)
3542                         return retval;
3543         }
3544
3545         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3546         if (IS_ERR(old.bh))
3547                 return PTR_ERR(old.bh);
3548         /*
3549          *  Check for inode number is _not_ due to possible IO errors.
3550          *  We might rmdir the source, keep it as pwd of some process
3551          *  and merrily kill the link to whatever was created under the
3552          *  same name. Goodbye sticky bit ;-<
3553          */
3554         retval = -ENOENT;
3555         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3556                 goto end_rename;
3557
3558         if ((old.dir != new.dir) &&
3559             ext4_encrypted_inode(new.dir) &&
3560             !ext4_is_child_context_consistent_with_parent(new.dir,
3561                                                           old.inode)) {
3562                 retval = -EPERM;
3563                 goto end_rename;
3564         }
3565
3566         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3567                                  &new.de, &new.inlined);
3568         if (IS_ERR(new.bh)) {
3569                 retval = PTR_ERR(new.bh);
3570                 new.bh = NULL;
3571                 goto end_rename;
3572         }
3573         if (new.bh) {
3574                 if (!new.inode) {
3575                         brelse(new.bh);
3576                         new.bh = NULL;
3577                 }
3578         }
3579         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3580                 ext4_alloc_da_blocks(old.inode);
3581
3582         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3583                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3584         if (!(flags & RENAME_WHITEOUT)) {
3585                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3586                 if (IS_ERR(handle)) {
3587                         retval = PTR_ERR(handle);
3588                         handle = NULL;
3589                         goto end_rename;
3590                 }
3591         } else {
3592                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3593                 if (IS_ERR(whiteout)) {
3594                         retval = PTR_ERR(whiteout);
3595                         whiteout = NULL;
3596                         goto end_rename;
3597                 }
3598         }
3599
3600         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3601                 ext4_handle_sync(handle);
3602
3603         if (S_ISDIR(old.inode->i_mode)) {
3604                 if (new.inode) {
3605                         retval = -ENOTEMPTY;
3606                         if (!ext4_empty_dir(new.inode))
3607                                 goto end_rename;
3608                 } else {
3609                         retval = -EMLINK;
3610                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3611                                 goto end_rename;
3612                 }
3613                 retval = ext4_rename_dir_prepare(handle, &old);
3614                 if (retval)
3615                         goto end_rename;
3616         }
3617         /*
3618          * If we're renaming a file within an inline_data dir and adding or
3619          * setting the new dirent causes a conversion from inline_data to
3620          * extents/blockmap, we need to force the dirent delete code to
3621          * re-read the directory, or else we end up trying to delete a dirent
3622          * from what is now the extent tree root (or a block map).
3623          */
3624         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3625                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3626
3627         old_file_type = old.de->file_type;
3628         if (whiteout) {
3629                 /*
3630                  * Do this before adding a new entry, so the old entry is sure
3631                  * to be still pointing to the valid old entry.
3632                  */
3633                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3634                                      EXT4_FT_CHRDEV);
3635                 if (retval)
3636                         goto end_rename;
3637                 ext4_mark_inode_dirty(handle, whiteout);
3638         }
3639         if (!new.bh) {
3640                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3641                 if (retval)
3642                         goto end_rename;
3643         } else {
3644                 retval = ext4_setent(handle, &new,
3645                                      old.inode->i_ino, old_file_type);
3646                 if (retval)
3647                         goto end_rename;
3648         }
3649         if (force_reread)
3650                 force_reread = !ext4_test_inode_flag(new.dir,
3651                                                      EXT4_INODE_INLINE_DATA);
3652
3653         /*
3654          * Like most other Unix systems, set the ctime for inodes on a
3655          * rename.
3656          */
3657         old.inode->i_ctime = ext4_current_time(old.inode);
3658         ext4_mark_inode_dirty(handle, old.inode);
3659
3660         if (!whiteout) {
3661                 /*
3662                  * ok, that's it
3663                  */
3664                 ext4_rename_delete(handle, &old, force_reread);
3665         }
3666
3667         if (new.inode) {
3668                 ext4_dec_count(handle, new.inode);
3669                 new.inode->i_ctime = ext4_current_time(new.inode);
3670         }
3671         old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3672         ext4_update_dx_flag(old.dir);
3673         if (old.dir_bh) {
3674                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3675                 if (retval)
3676                         goto end_rename;
3677
3678                 ext4_dec_count(handle, old.dir);
3679                 if (new.inode) {
3680                         /* checked ext4_empty_dir above, can't have another
3681                          * parent, ext4_dec_count() won't work for many-linked
3682                          * dirs */
3683                         clear_nlink(new.inode);
3684                 } else {
3685                         ext4_inc_count(handle, new.dir);
3686                         ext4_update_dx_flag(new.dir);
3687                         ext4_mark_inode_dirty(handle, new.dir);
3688                 }
3689         }
3690         ext4_mark_inode_dirty(handle, old.dir);
3691         if (new.inode) {
3692                 ext4_mark_inode_dirty(handle, new.inode);
3693                 if (!new.inode->i_nlink)
3694                         ext4_orphan_add(handle, new.inode);
3695         }
3696         retval = 0;
3697
3698 end_rename:
3699         brelse(old.dir_bh);
3700         brelse(old.bh);
3701         brelse(new.bh);
3702         if (whiteout) {
3703                 if (retval)
3704                         drop_nlink(whiteout);
3705                 unlock_new_inode(whiteout);
3706                 iput(whiteout);
3707         }
3708         if (handle)
3709                 ext4_journal_stop(handle);
3710         return retval;
3711 }
3712
3713 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3714                              struct inode *new_dir, struct dentry *new_dentry)
3715 {
3716         handle_t *handle = NULL;
3717         struct ext4_renament old = {
3718                 .dir = old_dir,
3719                 .dentry = old_dentry,
3720                 .inode = d_inode(old_dentry),
3721         };
3722         struct ext4_renament new = {
3723                 .dir = new_dir,
3724                 .dentry = new_dentry,
3725                 .inode = d_inode(new_dentry),
3726         };
3727         u8 new_file_type;
3728         int retval;
3729
3730         if ((ext4_encrypted_inode(old_dir) ||
3731              ext4_encrypted_inode(new_dir)) &&
3732             (old_dir != new_dir) &&
3733             (!ext4_is_child_context_consistent_with_parent(new_dir,
3734                                                            old.inode) ||
3735              !ext4_is_child_context_consistent_with_parent(old_dir,
3736                                                            new.inode)))
3737                 return -EPERM;
3738
3739         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3740              !projid_eq(EXT4_I(new_dir)->i_projid,
3741                         EXT4_I(old_dentry->d_inode)->i_projid)) ||
3742             (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3743              !projid_eq(EXT4_I(old_dir)->i_projid,
3744                         EXT4_I(new_dentry->d_inode)->i_projid)))
3745                 return -EXDEV;
3746
3747         retval = dquot_initialize(old.dir);
3748         if (retval)
3749                 return retval;
3750         retval = dquot_initialize(new.dir);
3751         if (retval)
3752                 return retval;
3753
3754         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3755                                  &old.de, &old.inlined);
3756         if (IS_ERR(old.bh))
3757                 return PTR_ERR(old.bh);
3758         /*
3759          *  Check for inode number is _not_ due to possible IO errors.
3760          *  We might rmdir the source, keep it as pwd of some process
3761          *  and merrily kill the link to whatever was created under the
3762          *  same name. Goodbye sticky bit ;-<
3763          */
3764         retval = -ENOENT;
3765         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3766                 goto end_rename;
3767
3768         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3769                                  &new.de, &new.inlined);
3770         if (IS_ERR(new.bh)) {
3771                 retval = PTR_ERR(new.bh);
3772                 new.bh = NULL;
3773                 goto end_rename;
3774         }
3775
3776         /* RENAME_EXCHANGE case: old *and* new must both exist */
3777         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3778                 goto end_rename;
3779
3780         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3781                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3782                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3783         if (IS_ERR(handle)) {
3784                 retval = PTR_ERR(handle);
3785                 handle = NULL;
3786                 goto end_rename;
3787         }
3788
3789         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3790                 ext4_handle_sync(handle);
3791
3792         if (S_ISDIR(old.inode->i_mode)) {
3793                 old.is_dir = true;
3794                 retval = ext4_rename_dir_prepare(handle, &old);
3795                 if (retval)
3796                         goto end_rename;
3797         }
3798         if (S_ISDIR(new.inode->i_mode)) {
3799                 new.is_dir = true;
3800                 retval = ext4_rename_dir_prepare(handle, &new);
3801                 if (retval)
3802                         goto end_rename;
3803         }
3804
3805         /*
3806          * Other than the special case of overwriting a directory, parents'
3807          * nlink only needs to be modified if this is a cross directory rename.
3808          */
3809         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3810                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3811                 new.dir_nlink_delta = -old.dir_nlink_delta;
3812                 retval = -EMLINK;
3813                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3814                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3815                         goto end_rename;
3816         }
3817
3818         new_file_type = new.de->file_type;
3819         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3820         if (retval)
3821                 goto end_rename;
3822
3823         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3824         if (retval)
3825                 goto end_rename;
3826
3827         /*
3828          * Like most other Unix systems, set the ctime for inodes on a
3829          * rename.
3830          */
3831         old.inode->i_ctime = ext4_current_time(old.inode);
3832         new.inode->i_ctime = ext4_current_time(new.inode);
3833         ext4_mark_inode_dirty(handle, old.inode);
3834         ext4_mark_inode_dirty(handle, new.inode);
3835
3836         if (old.dir_bh) {
3837                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3838                 if (retval)
3839                         goto end_rename;
3840         }
3841         if (new.dir_bh) {
3842                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3843                 if (retval)
3844                         goto end_rename;
3845         }
3846         ext4_update_dir_count(handle, &old);
3847         ext4_update_dir_count(handle, &new);
3848         retval = 0;
3849
3850 end_rename:
3851         brelse(old.dir_bh);
3852         brelse(new.dir_bh);
3853         brelse(old.bh);
3854         brelse(new.bh);
3855         if (handle)
3856                 ext4_journal_stop(handle);
3857         return retval;
3858 }
3859
3860 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3861                         struct inode *new_dir, struct dentry *new_dentry,
3862                         unsigned int flags)
3863 {
3864         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3865                 return -EINVAL;
3866
3867         if (flags & RENAME_EXCHANGE) {
3868                 return ext4_cross_rename(old_dir, old_dentry,
3869                                          new_dir, new_dentry);
3870         }
3871
3872         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3873 }
3874
3875 /*
3876  * directories can handle most operations...
3877  */
3878 const struct inode_operations ext4_dir_inode_operations = {
3879         .create         = ext4_create,
3880         .lookup         = ext4_lookup,
3881         .link           = ext4_link,
3882         .unlink         = ext4_unlink,
3883         .symlink        = ext4_symlink,
3884         .mkdir          = ext4_mkdir,
3885         .rmdir          = ext4_rmdir,
3886         .mknod          = ext4_mknod,
3887         .tmpfile        = ext4_tmpfile,
3888         .rename2        = ext4_rename2,
3889         .setattr        = ext4_setattr,
3890         .setxattr       = generic_setxattr,
3891         .getxattr       = generic_getxattr,
3892         .listxattr      = ext4_listxattr,
3893         .removexattr    = generic_removexattr,
3894         .get_acl        = ext4_get_acl,
3895         .set_acl        = ext4_set_acl,
3896         .fiemap         = ext4_fiemap,
3897 };
3898
3899 const struct inode_operations ext4_special_inode_operations = {
3900         .setattr        = ext4_setattr,
3901         .setxattr       = generic_setxattr,
3902         .getxattr       = generic_getxattr,
3903         .listxattr      = ext4_listxattr,
3904         .removexattr    = generic_removexattr,
3905         .get_acl        = ext4_get_acl,
3906         .set_acl        = ext4_set_acl,
3907 };