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 (fatal_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(REQ_OP_READ,
1447                                                     REQ_META | REQ_PRIO,
1448                                                     1, &bh);
1449                         }
1450                 }
1451                 if ((bh = bh_use[ra_ptr++]) == NULL)
1452                         goto next;
1453                 wait_on_buffer(bh);
1454                 if (!buffer_uptodate(bh)) {
1455                         /* read error, skip block & hope for the best */
1456                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1457                                          (unsigned long) block);
1458                         brelse(bh);
1459                         goto next;
1460                 }
1461                 if (!buffer_verified(bh) &&
1462                     !is_dx_internal_node(dir, block,
1463                                          (struct ext4_dir_entry *)bh->b_data) &&
1464                     !ext4_dirent_csum_verify(dir,
1465                                 (struct ext4_dir_entry *)bh->b_data)) {
1466                         EXT4_ERROR_INODE(dir, "checksumming directory "
1467                                          "block %lu", (unsigned long)block);
1468                         brelse(bh);
1469                         goto next;
1470                 }
1471                 set_buffer_verified(bh);
1472                 i = search_dirblock(bh, dir, &fname, d_name,
1473                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1474                 if (i == 1) {
1475                         EXT4_I(dir)->i_dir_start_lookup = block;
1476                         ret = bh;
1477                         goto cleanup_and_exit;
1478                 } else {
1479                         brelse(bh);
1480                         if (i < 0)
1481                                 goto cleanup_and_exit;
1482                 }
1483         next:
1484                 if (++block >= nblocks)
1485                         block = 0;
1486         } while (block != start);
1487
1488         /*
1489          * If the directory has grown while we were searching, then
1490          * search the last part of the directory before giving up.
1491          */
1492         block = nblocks;
1493         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1494         if (block < nblocks) {
1495                 start = 0;
1496                 goto restart;
1497         }
1498
1499 cleanup_and_exit:
1500         /* Clean up the read-ahead blocks */
1501         for (; ra_ptr < ra_max; ra_ptr++)
1502                 brelse(bh_use[ra_ptr]);
1503         ext4_fname_free_filename(&fname);
1504         return ret;
1505 }
1506
1507 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1508                         struct ext4_filename *fname,
1509                         struct ext4_dir_entry_2 **res_dir)
1510 {
1511         struct super_block * sb = dir->i_sb;
1512         struct dx_frame frames[2], *frame;
1513         const struct qstr *d_name = fname->usr_fname;
1514         struct buffer_head *bh;
1515         ext4_lblk_t block;
1516         int retval;
1517
1518 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1519         *res_dir = NULL;
1520 #endif
1521         frame = dx_probe(fname, dir, NULL, frames);
1522         if (IS_ERR(frame))
1523                 return (struct buffer_head *) frame;
1524         do {
1525                 block = dx_get_block(frame->at);
1526                 bh = ext4_read_dirblock(dir, block, DIRENT);
1527                 if (IS_ERR(bh))
1528                         goto errout;
1529
1530                 retval = search_dirblock(bh, dir, fname, d_name,
1531                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1532                                          res_dir);
1533                 if (retval == 1)
1534                         goto success;
1535                 brelse(bh);
1536                 if (retval == -1) {
1537                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1538                         goto errout;
1539                 }
1540
1541                 /* Check to see if we should continue to search */
1542                 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1543                                                frames, NULL);
1544                 if (retval < 0) {
1545                         ext4_warning_inode(dir,
1546                                 "error %d reading directory index block",
1547                                 retval);
1548                         bh = ERR_PTR(retval);
1549                         goto errout;
1550                 }
1551         } while (retval == 1);
1552
1553         bh = NULL;
1554 errout:
1555         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1556 success:
1557         dx_release(frames);
1558         return bh;
1559 }
1560
1561 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1562 {
1563         struct inode *inode;
1564         struct ext4_dir_entry_2 *de;
1565         struct buffer_head *bh;
1566
1567        if (ext4_encrypted_inode(dir)) {
1568                int res = ext4_get_encryption_info(dir);
1569
1570                 /*
1571                  * This should be a properly defined flag for
1572                  * dentry->d_flags when we uplift this to the VFS.
1573                  * d_fsdata is set to (void *) 1 if if the dentry is
1574                  * created while the directory was encrypted and we
1575                  * don't have access to the key.
1576                  */
1577                dentry->d_fsdata = NULL;
1578                if (ext4_encryption_info(dir))
1579                        dentry->d_fsdata = (void *) 1;
1580                d_set_d_op(dentry, &ext4_encrypted_d_ops);
1581                if (res && res != -ENOKEY)
1582                        return ERR_PTR(res);
1583        }
1584
1585         if (dentry->d_name.len > EXT4_NAME_LEN)
1586                 return ERR_PTR(-ENAMETOOLONG);
1587
1588         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1589         if (IS_ERR(bh))
1590                 return (struct dentry *) bh;
1591         inode = NULL;
1592         if (bh) {
1593                 __u32 ino = le32_to_cpu(de->inode);
1594                 brelse(bh);
1595                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1596                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1597                         return ERR_PTR(-EFSCORRUPTED);
1598                 }
1599                 if (unlikely(ino == dir->i_ino)) {
1600                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1601                                          dentry);
1602                         return ERR_PTR(-EFSCORRUPTED);
1603                 }
1604                 inode = ext4_iget_normal(dir->i_sb, ino);
1605                 if (inode == ERR_PTR(-ESTALE)) {
1606                         EXT4_ERROR_INODE(dir,
1607                                          "deleted inode referenced: %u",
1608                                          ino);
1609                         return ERR_PTR(-EFSCORRUPTED);
1610                 }
1611                 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1612                     (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1613                     !ext4_is_child_context_consistent_with_parent(dir,
1614                                                                   inode)) {
1615                         int nokey = ext4_encrypted_inode(inode) &&
1616                                 !ext4_encryption_info(inode);
1617
1618                         iput(inode);
1619                         if (nokey)
1620                                 return ERR_PTR(-ENOKEY);
1621                         ext4_warning(inode->i_sb,
1622                                      "Inconsistent encryption contexts: %lu/%lu",
1623                                      (unsigned long) dir->i_ino,
1624                                      (unsigned long) inode->i_ino);
1625                         return ERR_PTR(-EPERM);
1626                 }
1627         }
1628         return d_splice_alias(inode, dentry);
1629 }
1630
1631
1632 struct dentry *ext4_get_parent(struct dentry *child)
1633 {
1634         __u32 ino;
1635         static const struct qstr dotdot = QSTR_INIT("..", 2);
1636         struct ext4_dir_entry_2 * de;
1637         struct buffer_head *bh;
1638
1639         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1640         if (IS_ERR(bh))
1641                 return (struct dentry *) bh;
1642         if (!bh)
1643                 return ERR_PTR(-ENOENT);
1644         ino = le32_to_cpu(de->inode);
1645         brelse(bh);
1646
1647         if (!ext4_valid_inum(child->d_sb, ino)) {
1648                 EXT4_ERROR_INODE(d_inode(child),
1649                                  "bad parent inode number: %u", ino);
1650                 return ERR_PTR(-EFSCORRUPTED);
1651         }
1652
1653         return d_obtain_alias(ext4_iget_normal(child->d_sb, ino));
1654 }
1655
1656 /*
1657  * Move count entries from end of map between two memory locations.
1658  * Returns pointer to last entry moved.
1659  */
1660 static struct ext4_dir_entry_2 *
1661 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1662                 unsigned blocksize)
1663 {
1664         unsigned rec_len = 0;
1665
1666         while (count--) {
1667                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1668                                                 (from + (map->offs<<2));
1669                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1670                 memcpy (to, de, rec_len);
1671                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1672                                 ext4_rec_len_to_disk(rec_len, blocksize);
1673                 de->inode = 0;
1674                 map++;
1675                 to += rec_len;
1676         }
1677         return (struct ext4_dir_entry_2 *) (to - rec_len);
1678 }
1679
1680 /*
1681  * Compact each dir entry in the range to the minimal rec_len.
1682  * Returns pointer to last entry in range.
1683  */
1684 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1685 {
1686         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1687         unsigned rec_len = 0;
1688
1689         prev = to = de;
1690         while ((char*)de < base + blocksize) {
1691                 next = ext4_next_entry(de, blocksize);
1692                 if (de->inode && de->name_len) {
1693                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1694                         if (de > to)
1695                                 memmove(to, de, rec_len);
1696                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1697                         prev = to;
1698                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1699                 }
1700                 de = next;
1701         }
1702         return prev;
1703 }
1704
1705 /*
1706  * Split a full leaf block to make room for a new dir entry.
1707  * Allocate a new block, and move entries so that they are approx. equally full.
1708  * Returns pointer to de in block into which the new entry will be inserted.
1709  */
1710 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1711                         struct buffer_head **bh,struct dx_frame *frame,
1712                         struct dx_hash_info *hinfo)
1713 {
1714         unsigned blocksize = dir->i_sb->s_blocksize;
1715         unsigned count, continued;
1716         struct buffer_head *bh2;
1717         ext4_lblk_t newblock;
1718         u32 hash2;
1719         struct dx_map_entry *map;
1720         char *data1 = (*bh)->b_data, *data2;
1721         unsigned split, move, size;
1722         struct ext4_dir_entry_2 *de = NULL, *de2;
1723         struct ext4_dir_entry_tail *t;
1724         int     csum_size = 0;
1725         int     err = 0, i;
1726
1727         if (ext4_has_metadata_csum(dir->i_sb))
1728                 csum_size = sizeof(struct ext4_dir_entry_tail);
1729
1730         bh2 = ext4_append(handle, dir, &newblock);
1731         if (IS_ERR(bh2)) {
1732                 brelse(*bh);
1733                 *bh = NULL;
1734                 return (struct ext4_dir_entry_2 *) bh2;
1735         }
1736
1737         BUFFER_TRACE(*bh, "get_write_access");
1738         err = ext4_journal_get_write_access(handle, *bh);
1739         if (err)
1740                 goto journal_error;
1741
1742         BUFFER_TRACE(frame->bh, "get_write_access");
1743         err = ext4_journal_get_write_access(handle, frame->bh);
1744         if (err)
1745                 goto journal_error;
1746
1747         data2 = bh2->b_data;
1748
1749         /* create map in the end of data2 block */
1750         map = (struct dx_map_entry *) (data2 + blocksize);
1751         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1752                              blocksize, hinfo, map);
1753         map -= count;
1754         dx_sort_map(map, count);
1755         /* Split the existing block in the middle, size-wise */
1756         size = 0;
1757         move = 0;
1758         for (i = count-1; i >= 0; i--) {
1759                 /* is more than half of this entry in 2nd half of the block? */
1760                 if (size + map[i].size/2 > blocksize/2)
1761                         break;
1762                 size += map[i].size;
1763                 move++;
1764         }
1765         /* map index at which we will split */
1766         split = count - move;
1767         hash2 = map[split].hash;
1768         continued = hash2 == map[split - 1].hash;
1769         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1770                         (unsigned long)dx_get_block(frame->at),
1771                                         hash2, split, count-split));
1772
1773         /* Fancy dance to stay within two buffers */
1774         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1775                               blocksize);
1776         de = dx_pack_dirents(data1, blocksize);
1777         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1778                                            (char *) de,
1779                                            blocksize);
1780         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1781                                             (char *) de2,
1782                                             blocksize);
1783         if (csum_size) {
1784                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1785                 initialize_dirent_tail(t, blocksize);
1786
1787                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1788                 initialize_dirent_tail(t, blocksize);
1789         }
1790
1791         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1792                         blocksize, 1));
1793         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1794                         blocksize, 1));
1795
1796         /* Which block gets the new entry? */
1797         if (hinfo->hash >= hash2) {
1798                 swap(*bh, bh2);
1799                 de = de2;
1800         }
1801         dx_insert_block(frame, hash2 + continued, newblock);
1802         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1803         if (err)
1804                 goto journal_error;
1805         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1806         if (err)
1807                 goto journal_error;
1808         brelse(bh2);
1809         dxtrace(dx_show_index("frame", frame->entries));
1810         return de;
1811
1812 journal_error:
1813         brelse(*bh);
1814         brelse(bh2);
1815         *bh = NULL;
1816         ext4_std_error(dir->i_sb, err);
1817         return ERR_PTR(err);
1818 }
1819
1820 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1821                       struct buffer_head *bh,
1822                       void *buf, int buf_size,
1823                       struct ext4_filename *fname,
1824                       struct ext4_dir_entry_2 **dest_de)
1825 {
1826         struct ext4_dir_entry_2 *de;
1827         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1828         int nlen, rlen;
1829         unsigned int offset = 0;
1830         char *top;
1831         int res;
1832
1833         de = (struct ext4_dir_entry_2 *)buf;
1834         top = buf + buf_size - reclen;
1835         while ((char *) de <= top) {
1836                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1837                                          buf, buf_size, offset)) {
1838                         res = -EFSCORRUPTED;
1839                         goto return_result;
1840                 }
1841                 /* Provide crypto context and crypto buffer to ext4 match */
1842                 res = ext4_match(fname, de);
1843                 if (res < 0)
1844                         goto return_result;
1845                 if (res > 0) {
1846                         res = -EEXIST;
1847                         goto return_result;
1848                 }
1849                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1850                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1851                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1852                         break;
1853                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1854                 offset += rlen;
1855         }
1856
1857         if ((char *) de > top)
1858                 res = -ENOSPC;
1859         else {
1860                 *dest_de = de;
1861                 res = 0;
1862         }
1863 return_result:
1864         return res;
1865 }
1866
1867 int ext4_insert_dentry(struct inode *dir,
1868                        struct inode *inode,
1869                        struct ext4_dir_entry_2 *de,
1870                        int buf_size,
1871                        struct ext4_filename *fname)
1872 {
1873
1874         int nlen, rlen;
1875
1876         nlen = EXT4_DIR_REC_LEN(de->name_len);
1877         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1878         if (de->inode) {
1879                 struct ext4_dir_entry_2 *de1 =
1880                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1881                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1882                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1883                 de = de1;
1884         }
1885         de->file_type = EXT4_FT_UNKNOWN;
1886         de->inode = cpu_to_le32(inode->i_ino);
1887         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1888         de->name_len = fname_len(fname);
1889         memcpy(de->name, fname_name(fname), fname_len(fname));
1890         return 0;
1891 }
1892
1893 /*
1894  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1895  * it points to a directory entry which is guaranteed to be large
1896  * enough for new directory entry.  If de is NULL, then
1897  * add_dirent_to_buf will attempt search the directory block for
1898  * space.  It will return -ENOSPC if no space is available, and -EIO
1899  * and -EEXIST if directory entry already exists.
1900  */
1901 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1902                              struct inode *dir,
1903                              struct inode *inode, struct ext4_dir_entry_2 *de,
1904                              struct buffer_head *bh)
1905 {
1906         unsigned int    blocksize = dir->i_sb->s_blocksize;
1907         int             csum_size = 0;
1908         int             err;
1909
1910         if (ext4_has_metadata_csum(inode->i_sb))
1911                 csum_size = sizeof(struct ext4_dir_entry_tail);
1912
1913         if (!de) {
1914                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1915                                         blocksize - csum_size, fname, &de);
1916                 if (err)
1917                         return err;
1918         }
1919         BUFFER_TRACE(bh, "get_write_access");
1920         err = ext4_journal_get_write_access(handle, bh);
1921         if (err) {
1922                 ext4_std_error(dir->i_sb, err);
1923                 return err;
1924         }
1925
1926         /* By now the buffer is marked for journaling. Due to crypto operations,
1927          * the following function call may fail */
1928         err = ext4_insert_dentry(dir, inode, de, blocksize, fname);
1929         if (err < 0)
1930                 return err;
1931
1932         /*
1933          * XXX shouldn't update any times until successful
1934          * completion of syscall, but too many callers depend
1935          * on this.
1936          *
1937          * XXX similarly, too many callers depend on
1938          * ext4_new_inode() setting the times, but error
1939          * recovery deletes the inode, so the worst that can
1940          * happen is that the times are slightly out of date
1941          * and/or different from the directory change time.
1942          */
1943         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1944         ext4_update_dx_flag(dir);
1945         dir->i_version++;
1946         ext4_mark_inode_dirty(handle, dir);
1947         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1948         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1949         if (err)
1950                 ext4_std_error(dir->i_sb, err);
1951         return 0;
1952 }
1953
1954 /*
1955  * This converts a one block unindexed directory to a 3 block indexed
1956  * directory, and adds the dentry to the indexed directory.
1957  */
1958 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1959                             struct inode *dir,
1960                             struct inode *inode, struct buffer_head *bh)
1961 {
1962         struct buffer_head *bh2;
1963         struct dx_root  *root;
1964         struct dx_frame frames[2], *frame;
1965         struct dx_entry *entries;
1966         struct ext4_dir_entry_2 *de, *de2;
1967         struct ext4_dir_entry_tail *t;
1968         char            *data1, *top;
1969         unsigned        len;
1970         int             retval;
1971         unsigned        blocksize;
1972         ext4_lblk_t  block;
1973         struct fake_dirent *fde;
1974         int csum_size = 0;
1975
1976         if (ext4_has_metadata_csum(inode->i_sb))
1977                 csum_size = sizeof(struct ext4_dir_entry_tail);
1978
1979         blocksize =  dir->i_sb->s_blocksize;
1980         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1981         BUFFER_TRACE(bh, "get_write_access");
1982         retval = ext4_journal_get_write_access(handle, bh);
1983         if (retval) {
1984                 ext4_std_error(dir->i_sb, retval);
1985                 brelse(bh);
1986                 return retval;
1987         }
1988         root = (struct dx_root *) bh->b_data;
1989
1990         /* The 0th block becomes the root, move the dirents out */
1991         fde = &root->dotdot;
1992         de = (struct ext4_dir_entry_2 *)((char *)fde +
1993                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1994         if ((char *) de >= (((char *) root) + blocksize)) {
1995                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1996                 brelse(bh);
1997                 return -EFSCORRUPTED;
1998         }
1999         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2000
2001         /* Allocate new block for the 0th block's dirents */
2002         bh2 = ext4_append(handle, dir, &block);
2003         if (IS_ERR(bh2)) {
2004                 brelse(bh);
2005                 return PTR_ERR(bh2);
2006         }
2007         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2008         data1 = bh2->b_data;
2009
2010         memcpy (data1, de, len);
2011         de = (struct ext4_dir_entry_2 *) data1;
2012         top = data1 + len;
2013         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2014                 de = de2;
2015         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2016                                            (char *) de,
2017                                            blocksize);
2018
2019         if (csum_size) {
2020                 t = EXT4_DIRENT_TAIL(data1, blocksize);
2021                 initialize_dirent_tail(t, blocksize);
2022         }
2023
2024         /* Initialize the root; the dot dirents already exist */
2025         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2026         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2027                                            blocksize);
2028         memset (&root->info, 0, sizeof(root->info));
2029         root->info.info_length = sizeof(root->info);
2030         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2031         entries = root->entries;
2032         dx_set_block(entries, 1);
2033         dx_set_count(entries, 1);
2034         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2035
2036         /* Initialize as for dx_probe */
2037         fname->hinfo.hash_version = root->info.hash_version;
2038         if (fname->hinfo.hash_version <= DX_HASH_TEA)
2039                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2040         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2041         ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
2042
2043         memset(frames, 0, sizeof(frames));
2044         frame = frames;
2045         frame->entries = entries;
2046         frame->at = entries;
2047         frame->bh = bh;
2048         bh = bh2;
2049
2050         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2051         if (retval)
2052                 goto out_frames;
2053         retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
2054         if (retval)
2055                 goto out_frames;
2056
2057         de = do_split(handle,dir, &bh, frame, &fname->hinfo);
2058         if (IS_ERR(de)) {
2059                 retval = PTR_ERR(de);
2060                 goto out_frames;
2061         }
2062         dx_release(frames);
2063
2064         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2065         brelse(bh);
2066         return retval;
2067 out_frames:
2068         /*
2069          * Even if the block split failed, we have to properly write
2070          * out all the changes we did so far. Otherwise we can end up
2071          * with corrupted filesystem.
2072          */
2073         ext4_mark_inode_dirty(handle, dir);
2074         dx_release(frames);
2075         return retval;
2076 }
2077
2078 /*
2079  *      ext4_add_entry()
2080  *
2081  * adds a file entry to the specified directory, using the same
2082  * semantics as ext4_find_entry(). It returns NULL if it failed.
2083  *
2084  * NOTE!! The inode part of 'de' is left at 0 - which means you
2085  * may not sleep between calling this and putting something into
2086  * the entry, as someone else might have used it while you slept.
2087  */
2088 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2089                           struct inode *inode)
2090 {
2091         struct inode *dir = d_inode(dentry->d_parent);
2092         struct buffer_head *bh = NULL;
2093         struct ext4_dir_entry_2 *de;
2094         struct ext4_dir_entry_tail *t;
2095         struct super_block *sb;
2096         struct ext4_filename fname;
2097         int     retval;
2098         int     dx_fallback=0;
2099         unsigned blocksize;
2100         ext4_lblk_t block, blocks;
2101         int     csum_size = 0;
2102
2103         if (ext4_has_metadata_csum(inode->i_sb))
2104                 csum_size = sizeof(struct ext4_dir_entry_tail);
2105
2106         sb = dir->i_sb;
2107         blocksize = sb->s_blocksize;
2108         if (!dentry->d_name.len)
2109                 return -EINVAL;
2110
2111         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2112         if (retval)
2113                 return retval;
2114
2115         if (ext4_has_inline_data(dir)) {
2116                 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2117                 if (retval < 0)
2118                         goto out;
2119                 if (retval == 1) {
2120                         retval = 0;
2121                         goto out;
2122                 }
2123         }
2124
2125         if (is_dx(dir)) {
2126                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2127                 if (!retval || (retval != ERR_BAD_DX_DIR))
2128                         goto out;
2129                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2130                 dx_fallback++;
2131                 ext4_mark_inode_dirty(handle, dir);
2132         }
2133         blocks = dir->i_size >> sb->s_blocksize_bits;
2134         for (block = 0; block < blocks; block++) {
2135                 bh = ext4_read_dirblock(dir, block, DIRENT);
2136                 if (IS_ERR(bh)) {
2137                         retval = PTR_ERR(bh);
2138                         bh = NULL;
2139                         goto out;
2140                 }
2141                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2142                                            NULL, bh);
2143                 if (retval != -ENOSPC)
2144                         goto out;
2145
2146                 if (blocks == 1 && !dx_fallback &&
2147                     ext4_has_feature_dir_index(sb)) {
2148                         retval = make_indexed_dir(handle, &fname, dir,
2149                                                   inode, bh);
2150                         bh = NULL; /* make_indexed_dir releases bh */
2151                         goto out;
2152                 }
2153                 brelse(bh);
2154         }
2155         bh = ext4_append(handle, dir, &block);
2156         if (IS_ERR(bh)) {
2157                 retval = PTR_ERR(bh);
2158                 bh = NULL;
2159                 goto out;
2160         }
2161         de = (struct ext4_dir_entry_2 *) bh->b_data;
2162         de->inode = 0;
2163         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2164
2165         if (csum_size) {
2166                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2167                 initialize_dirent_tail(t, blocksize);
2168         }
2169
2170         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2171 out:
2172         ext4_fname_free_filename(&fname);
2173         brelse(bh);
2174         if (retval == 0)
2175                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2176         return retval;
2177 }
2178
2179 /*
2180  * Returns 0 for success, or a negative error value
2181  */
2182 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2183                              struct inode *dir, struct inode *inode)
2184 {
2185         struct dx_frame frames[2], *frame;
2186         struct dx_entry *entries, *at;
2187         struct buffer_head *bh;
2188         struct super_block *sb = dir->i_sb;
2189         struct ext4_dir_entry_2 *de;
2190         int err;
2191
2192         frame = dx_probe(fname, dir, NULL, frames);
2193         if (IS_ERR(frame))
2194                 return PTR_ERR(frame);
2195         entries = frame->entries;
2196         at = frame->at;
2197         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2198         if (IS_ERR(bh)) {
2199                 err = PTR_ERR(bh);
2200                 bh = NULL;
2201                 goto cleanup;
2202         }
2203
2204         BUFFER_TRACE(bh, "get_write_access");
2205         err = ext4_journal_get_write_access(handle, bh);
2206         if (err)
2207                 goto journal_error;
2208
2209         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2210         if (err != -ENOSPC)
2211                 goto cleanup;
2212
2213         /* Block full, should compress but for now just split */
2214         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2215                        dx_get_count(entries), dx_get_limit(entries)));
2216         /* Need to split index? */
2217         if (dx_get_count(entries) == dx_get_limit(entries)) {
2218                 ext4_lblk_t newblock;
2219                 unsigned icount = dx_get_count(entries);
2220                 int levels = frame - frames;
2221                 struct dx_entry *entries2;
2222                 struct dx_node *node2;
2223                 struct buffer_head *bh2;
2224
2225                 if (levels && (dx_get_count(frames->entries) ==
2226                                dx_get_limit(frames->entries))) {
2227                         ext4_warning_inode(dir, "Directory index full!");
2228                         err = -ENOSPC;
2229                         goto cleanup;
2230                 }
2231                 bh2 = ext4_append(handle, dir, &newblock);
2232                 if (IS_ERR(bh2)) {
2233                         err = PTR_ERR(bh2);
2234                         goto cleanup;
2235                 }
2236                 node2 = (struct dx_node *)(bh2->b_data);
2237                 entries2 = node2->entries;
2238                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2239                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2240                                                            sb->s_blocksize);
2241                 BUFFER_TRACE(frame->bh, "get_write_access");
2242                 err = ext4_journal_get_write_access(handle, frame->bh);
2243                 if (err)
2244                         goto journal_error;
2245                 if (levels) {
2246                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2247                         unsigned hash2 = dx_get_hash(entries + icount1);
2248                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2249                                        icount1, icount2));
2250
2251                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2252                         err = ext4_journal_get_write_access(handle,
2253                                                              frames[0].bh);
2254                         if (err)
2255                                 goto journal_error;
2256
2257                         memcpy((char *) entries2, (char *) (entries + icount1),
2258                                icount2 * sizeof(struct dx_entry));
2259                         dx_set_count(entries, icount1);
2260                         dx_set_count(entries2, icount2);
2261                         dx_set_limit(entries2, dx_node_limit(dir));
2262
2263                         /* Which index block gets the new entry? */
2264                         if (at - entries >= icount1) {
2265                                 frame->at = at = at - entries - icount1 + entries2;
2266                                 frame->entries = entries = entries2;
2267                                 swap(frame->bh, bh2);
2268                         }
2269                         dx_insert_block(frames + 0, hash2, newblock);
2270                         dxtrace(dx_show_index("node", frames[1].entries));
2271                         dxtrace(dx_show_index("node",
2272                                ((struct dx_node *) bh2->b_data)->entries));
2273                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2274                         if (err)
2275                                 goto journal_error;
2276                         brelse (bh2);
2277                 } else {
2278                         dxtrace(printk(KERN_DEBUG
2279                                        "Creating second level index...\n"));
2280                         memcpy((char *) entries2, (char *) entries,
2281                                icount * sizeof(struct dx_entry));
2282                         dx_set_limit(entries2, dx_node_limit(dir));
2283
2284                         /* Set up root */
2285                         dx_set_count(entries, 1);
2286                         dx_set_block(entries + 0, newblock);
2287                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2288
2289                         /* Add new access path frame */
2290                         frame = frames + 1;
2291                         frame->at = at = at - entries + entries2;
2292                         frame->entries = entries = entries2;
2293                         frame->bh = bh2;
2294                         err = ext4_journal_get_write_access(handle,
2295                                                              frame->bh);
2296                         if (err)
2297                                 goto journal_error;
2298                 }
2299                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2300                 if (err) {
2301                         ext4_std_error(inode->i_sb, err);
2302                         goto cleanup;
2303                 }
2304         }
2305         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2306         if (IS_ERR(de)) {
2307                 err = PTR_ERR(de);
2308                 goto cleanup;
2309         }
2310         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2311         goto cleanup;
2312
2313 journal_error:
2314         ext4_std_error(dir->i_sb, err);
2315 cleanup:
2316         brelse(bh);
2317         dx_release(frames);
2318         return err;
2319 }
2320
2321 /*
2322  * ext4_generic_delete_entry deletes a directory entry by merging it
2323  * with the previous entry
2324  */
2325 int ext4_generic_delete_entry(handle_t *handle,
2326                               struct inode *dir,
2327                               struct ext4_dir_entry_2 *de_del,
2328                               struct buffer_head *bh,
2329                               void *entry_buf,
2330                               int buf_size,
2331                               int csum_size)
2332 {
2333         struct ext4_dir_entry_2 *de, *pde;
2334         unsigned int blocksize = dir->i_sb->s_blocksize;
2335         int i;
2336
2337         i = 0;
2338         pde = NULL;
2339         de = (struct ext4_dir_entry_2 *)entry_buf;
2340         while (i < buf_size - csum_size) {
2341                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2342                                          bh->b_data, bh->b_size, i))
2343                         return -EFSCORRUPTED;
2344                 if (de == de_del)  {
2345                         if (pde)
2346                                 pde->rec_len = ext4_rec_len_to_disk(
2347                                         ext4_rec_len_from_disk(pde->rec_len,
2348                                                                blocksize) +
2349                                         ext4_rec_len_from_disk(de->rec_len,
2350                                                                blocksize),
2351                                         blocksize);
2352                         else
2353                                 de->inode = 0;
2354                         dir->i_version++;
2355                         return 0;
2356                 }
2357                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2358                 pde = de;
2359                 de = ext4_next_entry(de, blocksize);
2360         }
2361         return -ENOENT;
2362 }
2363
2364 static int ext4_delete_entry(handle_t *handle,
2365                              struct inode *dir,
2366                              struct ext4_dir_entry_2 *de_del,
2367                              struct buffer_head *bh)
2368 {
2369         int err, csum_size = 0;
2370
2371         if (ext4_has_inline_data(dir)) {
2372                 int has_inline_data = 1;
2373                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2374                                                &has_inline_data);
2375                 if (has_inline_data)
2376                         return err;
2377         }
2378
2379         if (ext4_has_metadata_csum(dir->i_sb))
2380                 csum_size = sizeof(struct ext4_dir_entry_tail);
2381
2382         BUFFER_TRACE(bh, "get_write_access");
2383         err = ext4_journal_get_write_access(handle, bh);
2384         if (unlikely(err))
2385                 goto out;
2386
2387         err = ext4_generic_delete_entry(handle, dir, de_del,
2388                                         bh, bh->b_data,
2389                                         dir->i_sb->s_blocksize, csum_size);
2390         if (err)
2391                 goto out;
2392
2393         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2394         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2395         if (unlikely(err))
2396                 goto out;
2397
2398         return 0;
2399 out:
2400         if (err != -ENOENT)
2401                 ext4_std_error(dir->i_sb, err);
2402         return err;
2403 }
2404
2405 /*
2406  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2407  * since this indicates that nlinks count was previously 1.
2408  */
2409 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2410 {
2411         inc_nlink(inode);
2412         if (is_dx(inode) && inode->i_nlink > 1) {
2413                 /* limit is 16-bit i_links_count */
2414                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2415                         set_nlink(inode, 1);
2416                         ext4_set_feature_dir_nlink(inode->i_sb);
2417                 }
2418         }
2419 }
2420
2421 /*
2422  * If a directory had nlink == 1, then we should let it be 1. This indicates
2423  * directory has >EXT4_LINK_MAX subdirs.
2424  */
2425 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2426 {
2427         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2428                 drop_nlink(inode);
2429 }
2430
2431
2432 static int ext4_add_nondir(handle_t *handle,
2433                 struct dentry *dentry, struct inode *inode)
2434 {
2435         int err = ext4_add_entry(handle, dentry, inode);
2436         if (!err) {
2437                 ext4_mark_inode_dirty(handle, inode);
2438                 unlock_new_inode(inode);
2439                 d_instantiate(dentry, inode);
2440                 return 0;
2441         }
2442         drop_nlink(inode);
2443         unlock_new_inode(inode);
2444         iput(inode);
2445         return err;
2446 }
2447
2448 /*
2449  * By the time this is called, we already have created
2450  * the directory cache entry for the new file, but it
2451  * is so far negative - it has no inode.
2452  *
2453  * If the create succeeds, we fill in the inode information
2454  * with d_instantiate().
2455  */
2456 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2457                        bool excl)
2458 {
2459         handle_t *handle;
2460         struct inode *inode;
2461         int err, credits, retries = 0;
2462
2463         err = dquot_initialize(dir);
2464         if (err)
2465                 return err;
2466
2467         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2468                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2469 retry:
2470         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2471                                             NULL, EXT4_HT_DIR, credits);
2472         handle = ext4_journal_current_handle();
2473         err = PTR_ERR(inode);
2474         if (!IS_ERR(inode)) {
2475                 inode->i_op = &ext4_file_inode_operations;
2476                 inode->i_fop = &ext4_file_operations;
2477                 ext4_set_aops(inode);
2478                 err = ext4_add_nondir(handle, dentry, inode);
2479                 if (!err && IS_DIRSYNC(dir))
2480                         ext4_handle_sync(handle);
2481         }
2482         if (handle)
2483                 ext4_journal_stop(handle);
2484         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2485                 goto retry;
2486         return err;
2487 }
2488
2489 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2490                       umode_t mode, dev_t rdev)
2491 {
2492         handle_t *handle;
2493         struct inode *inode;
2494         int err, credits, retries = 0;
2495
2496         err = dquot_initialize(dir);
2497         if (err)
2498                 return err;
2499
2500         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2501                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2502 retry:
2503         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2504                                             NULL, EXT4_HT_DIR, credits);
2505         handle = ext4_journal_current_handle();
2506         err = PTR_ERR(inode);
2507         if (!IS_ERR(inode)) {
2508                 init_special_inode(inode, inode->i_mode, rdev);
2509                 inode->i_op = &ext4_special_inode_operations;
2510                 err = ext4_add_nondir(handle, dentry, inode);
2511                 if (!err && IS_DIRSYNC(dir))
2512                         ext4_handle_sync(handle);
2513         }
2514         if (handle)
2515                 ext4_journal_stop(handle);
2516         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2517                 goto retry;
2518         return err;
2519 }
2520
2521 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2522 {
2523         handle_t *handle;
2524         struct inode *inode;
2525         int err, retries = 0;
2526
2527         err = dquot_initialize(dir);
2528         if (err)
2529                 return err;
2530
2531 retry:
2532         inode = ext4_new_inode_start_handle(dir, mode,
2533                                             NULL, 0, NULL,
2534                                             EXT4_HT_DIR,
2535                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2536                           4 + EXT4_XATTR_TRANS_BLOCKS);
2537         handle = ext4_journal_current_handle();
2538         err = PTR_ERR(inode);
2539         if (!IS_ERR(inode)) {
2540                 inode->i_op = &ext4_file_inode_operations;
2541                 inode->i_fop = &ext4_file_operations;
2542                 ext4_set_aops(inode);
2543                 d_tmpfile(dentry, inode);
2544                 err = ext4_orphan_add(handle, inode);
2545                 if (err)
2546                         goto err_unlock_inode;
2547                 mark_inode_dirty(inode);
2548                 unlock_new_inode(inode);
2549         }
2550         if (handle)
2551                 ext4_journal_stop(handle);
2552         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2553                 goto retry;
2554         return err;
2555 err_unlock_inode:
2556         ext4_journal_stop(handle);
2557         unlock_new_inode(inode);
2558         return err;
2559 }
2560
2561 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2562                           struct ext4_dir_entry_2 *de,
2563                           int blocksize, int csum_size,
2564                           unsigned int parent_ino, int dotdot_real_len)
2565 {
2566         de->inode = cpu_to_le32(inode->i_ino);
2567         de->name_len = 1;
2568         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2569                                            blocksize);
2570         strcpy(de->name, ".");
2571         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2572
2573         de = ext4_next_entry(de, blocksize);
2574         de->inode = cpu_to_le32(parent_ino);
2575         de->name_len = 2;
2576         if (!dotdot_real_len)
2577                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2578                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2579                                         blocksize);
2580         else
2581                 de->rec_len = ext4_rec_len_to_disk(
2582                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2583         strcpy(de->name, "..");
2584         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2585
2586         return ext4_next_entry(de, blocksize);
2587 }
2588
2589 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2590                              struct inode *inode)
2591 {
2592         struct buffer_head *dir_block = NULL;
2593         struct ext4_dir_entry_2 *de;
2594         struct ext4_dir_entry_tail *t;
2595         ext4_lblk_t block = 0;
2596         unsigned int blocksize = dir->i_sb->s_blocksize;
2597         int csum_size = 0;
2598         int err;
2599
2600         if (ext4_has_metadata_csum(dir->i_sb))
2601                 csum_size = sizeof(struct ext4_dir_entry_tail);
2602
2603         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2604                 err = ext4_try_create_inline_dir(handle, dir, inode);
2605                 if (err < 0 && err != -ENOSPC)
2606                         goto out;
2607                 if (!err)
2608                         goto out;
2609         }
2610
2611         inode->i_size = 0;
2612         dir_block = ext4_append(handle, inode, &block);
2613         if (IS_ERR(dir_block))
2614                 return PTR_ERR(dir_block);
2615         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2616         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2617         set_nlink(inode, 2);
2618         if (csum_size) {
2619                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2620                 initialize_dirent_tail(t, blocksize);
2621         }
2622
2623         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2624         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2625         if (err)
2626                 goto out;
2627         set_buffer_verified(dir_block);
2628 out:
2629         brelse(dir_block);
2630         return err;
2631 }
2632
2633 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2634 {
2635         handle_t *handle;
2636         struct inode *inode;
2637         int err, credits, retries = 0;
2638
2639         if (EXT4_DIR_LINK_MAX(dir))
2640                 return -EMLINK;
2641
2642         err = dquot_initialize(dir);
2643         if (err)
2644                 return err;
2645
2646         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2647                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2648 retry:
2649         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2650                                             &dentry->d_name,
2651                                             0, NULL, EXT4_HT_DIR, credits);
2652         handle = ext4_journal_current_handle();
2653         err = PTR_ERR(inode);
2654         if (IS_ERR(inode))
2655                 goto out_stop;
2656
2657         inode->i_op = &ext4_dir_inode_operations;
2658         inode->i_fop = &ext4_dir_operations;
2659         err = ext4_init_new_dir(handle, dir, inode);
2660         if (err)
2661                 goto out_clear_inode;
2662         err = ext4_mark_inode_dirty(handle, inode);
2663         if (!err)
2664                 err = ext4_add_entry(handle, dentry, inode);
2665         if (err) {
2666 out_clear_inode:
2667                 clear_nlink(inode);
2668                 unlock_new_inode(inode);
2669                 ext4_mark_inode_dirty(handle, inode);
2670                 iput(inode);
2671                 goto out_stop;
2672         }
2673         ext4_inc_count(handle, dir);
2674         ext4_update_dx_flag(dir);
2675         err = ext4_mark_inode_dirty(handle, dir);
2676         if (err)
2677                 goto out_clear_inode;
2678         unlock_new_inode(inode);
2679         d_instantiate(dentry, inode);
2680         if (IS_DIRSYNC(dir))
2681                 ext4_handle_sync(handle);
2682
2683 out_stop:
2684         if (handle)
2685                 ext4_journal_stop(handle);
2686         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2687                 goto retry;
2688         return err;
2689 }
2690
2691 /*
2692  * routine to check that the specified directory is empty (for rmdir)
2693  */
2694 int ext4_empty_dir(struct inode *inode)
2695 {
2696         unsigned int offset;
2697         struct buffer_head *bh;
2698         struct ext4_dir_entry_2 *de, *de1;
2699         struct super_block *sb;
2700         int err = 0;
2701
2702         if (ext4_has_inline_data(inode)) {
2703                 int has_inline_data = 1;
2704
2705                 err = empty_inline_dir(inode, &has_inline_data);
2706                 if (has_inline_data)
2707                         return err;
2708         }
2709
2710         sb = inode->i_sb;
2711         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2712                 EXT4_ERROR_INODE(inode, "invalid size");
2713                 return 1;
2714         }
2715         bh = ext4_read_dirblock(inode, 0, EITHER);
2716         if (IS_ERR(bh))
2717                 return 1;
2718
2719         de = (struct ext4_dir_entry_2 *) bh->b_data;
2720         de1 = ext4_next_entry(de, sb->s_blocksize);
2721         if (le32_to_cpu(de->inode) != inode->i_ino ||
2722                         le32_to_cpu(de1->inode) == 0 ||
2723                         strcmp(".", de->name) || strcmp("..", de1->name)) {
2724                 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2725                 brelse(bh);
2726                 return 1;
2727         }
2728         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2729                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2730         de = ext4_next_entry(de1, sb->s_blocksize);
2731         while (offset < inode->i_size) {
2732                 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2733                         unsigned int lblock;
2734                         err = 0;
2735                         brelse(bh);
2736                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2737                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2738                         if (IS_ERR(bh))
2739                                 return 1;
2740                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2741                 }
2742                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2743                                          bh->b_data, bh->b_size, offset)) {
2744                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2745                                                          sb->s_blocksize);
2746                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2747                         continue;
2748                 }
2749                 if (le32_to_cpu(de->inode)) {
2750                         brelse(bh);
2751                         return 0;
2752                 }
2753                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2754                 de = ext4_next_entry(de, sb->s_blocksize);
2755         }
2756         brelse(bh);
2757         return 1;
2758 }
2759
2760 /*
2761  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2762  * such inodes, starting at the superblock, in case we crash before the
2763  * file is closed/deleted, or in case the inode truncate spans multiple
2764  * transactions and the last transaction is not recovered after a crash.
2765  *
2766  * At filesystem recovery time, we walk this list deleting unlinked
2767  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2768  *
2769  * Orphan list manipulation functions must be called under i_mutex unless
2770  * we are just creating the inode or deleting it.
2771  */
2772 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2773 {
2774         struct super_block *sb = inode->i_sb;
2775         struct ext4_sb_info *sbi = EXT4_SB(sb);
2776         struct ext4_iloc iloc;
2777         int err = 0, rc;
2778         bool dirty = false;
2779
2780         if (!sbi->s_journal || is_bad_inode(inode))
2781                 return 0;
2782
2783         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2784                      !inode_is_locked(inode));
2785         /*
2786          * Exit early if inode already is on orphan list. This is a big speedup
2787          * since we don't have to contend on the global s_orphan_lock.
2788          */
2789         if (!list_empty(&EXT4_I(inode)->i_orphan))
2790                 return 0;
2791
2792         /*
2793          * Orphan handling is only valid for files with data blocks
2794          * being truncated, or files being unlinked. Note that we either
2795          * hold i_mutex, or the inode can not be referenced from outside,
2796          * so i_nlink should not be bumped due to race
2797          */
2798         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2799                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2800
2801         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2802         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2803         if (err)
2804                 goto out;
2805
2806         err = ext4_reserve_inode_write(handle, inode, &iloc);
2807         if (err)
2808                 goto out;
2809
2810         mutex_lock(&sbi->s_orphan_lock);
2811         /*
2812          * Due to previous errors inode may be already a part of on-disk
2813          * orphan list. If so skip on-disk list modification.
2814          */
2815         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2816             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2817                 /* Insert this inode at the head of the on-disk orphan list */
2818                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2819                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2820                 dirty = true;
2821         }
2822         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2823         mutex_unlock(&sbi->s_orphan_lock);
2824
2825         if (dirty) {
2826                 err = ext4_handle_dirty_super(handle, sb);
2827                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2828                 if (!err)
2829                         err = rc;
2830                 if (err) {
2831                         /*
2832                          * We have to remove inode from in-memory list if
2833                          * addition to on disk orphan list failed. Stray orphan
2834                          * list entries can cause panics at unmount time.
2835                          */
2836                         mutex_lock(&sbi->s_orphan_lock);
2837                         list_del_init(&EXT4_I(inode)->i_orphan);
2838                         mutex_unlock(&sbi->s_orphan_lock);
2839                 }
2840         }
2841         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2842         jbd_debug(4, "orphan inode %lu will point to %d\n",
2843                         inode->i_ino, NEXT_ORPHAN(inode));
2844 out:
2845         ext4_std_error(sb, err);
2846         return err;
2847 }
2848
2849 /*
2850  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2851  * of such inodes stored on disk, because it is finally being cleaned up.
2852  */
2853 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2854 {
2855         struct list_head *prev;
2856         struct ext4_inode_info *ei = EXT4_I(inode);
2857         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2858         __u32 ino_next;
2859         struct ext4_iloc iloc;
2860         int err = 0;
2861
2862         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2863                 return 0;
2864
2865         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2866                      !inode_is_locked(inode));
2867         /* Do this quick check before taking global s_orphan_lock. */
2868         if (list_empty(&ei->i_orphan))
2869                 return 0;
2870
2871         if (handle) {
2872                 /* Grab inode buffer early before taking global s_orphan_lock */
2873                 err = ext4_reserve_inode_write(handle, inode, &iloc);
2874         }
2875
2876         mutex_lock(&sbi->s_orphan_lock);
2877         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2878
2879         prev = ei->i_orphan.prev;
2880         list_del_init(&ei->i_orphan);
2881
2882         /* If we're on an error path, we may not have a valid
2883          * transaction handle with which to update the orphan list on
2884          * disk, but we still need to remove the inode from the linked
2885          * list in memory. */
2886         if (!handle || err) {
2887                 mutex_unlock(&sbi->s_orphan_lock);
2888                 goto out_err;
2889         }
2890
2891         ino_next = NEXT_ORPHAN(inode);
2892         if (prev == &sbi->s_orphan) {
2893                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2894                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2895                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2896                 if (err) {
2897                         mutex_unlock(&sbi->s_orphan_lock);
2898                         goto out_brelse;
2899                 }
2900                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2901                 mutex_unlock(&sbi->s_orphan_lock);
2902                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2903         } else {
2904                 struct ext4_iloc iloc2;
2905                 struct inode *i_prev =
2906                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2907
2908                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2909                           i_prev->i_ino, ino_next);
2910                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2911                 if (err) {
2912                         mutex_unlock(&sbi->s_orphan_lock);
2913                         goto out_brelse;
2914                 }
2915                 NEXT_ORPHAN(i_prev) = ino_next;
2916                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2917                 mutex_unlock(&sbi->s_orphan_lock);
2918         }
2919         if (err)
2920                 goto out_brelse;
2921         NEXT_ORPHAN(inode) = 0;
2922         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2923 out_err:
2924         ext4_std_error(inode->i_sb, err);
2925         return err;
2926
2927 out_brelse:
2928         brelse(iloc.bh);
2929         goto out_err;
2930 }
2931
2932 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2933 {
2934         int retval;
2935         struct inode *inode;
2936         struct buffer_head *bh;
2937         struct ext4_dir_entry_2 *de;
2938         handle_t *handle = NULL;
2939
2940         /* Initialize quotas before so that eventual writes go in
2941          * separate transaction */
2942         retval = dquot_initialize(dir);
2943         if (retval)
2944                 return retval;
2945         retval = dquot_initialize(d_inode(dentry));
2946         if (retval)
2947                 return retval;
2948
2949         retval = -ENOENT;
2950         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2951         if (IS_ERR(bh))
2952                 return PTR_ERR(bh);
2953         if (!bh)
2954                 goto end_rmdir;
2955
2956         inode = d_inode(dentry);
2957
2958         retval = -EFSCORRUPTED;
2959         if (le32_to_cpu(de->inode) != inode->i_ino)
2960                 goto end_rmdir;
2961
2962         retval = -ENOTEMPTY;
2963         if (!ext4_empty_dir(inode))
2964                 goto end_rmdir;
2965
2966         handle = ext4_journal_start(dir, EXT4_HT_DIR,
2967                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2968         if (IS_ERR(handle)) {
2969                 retval = PTR_ERR(handle);
2970                 handle = NULL;
2971                 goto end_rmdir;
2972         }
2973
2974         if (IS_DIRSYNC(dir))
2975                 ext4_handle_sync(handle);
2976
2977         retval = ext4_delete_entry(handle, dir, de, bh);
2978         if (retval)
2979                 goto end_rmdir;
2980         if (!EXT4_DIR_LINK_EMPTY(inode))
2981                 ext4_warning_inode(inode,
2982                              "empty directory '%.*s' has too many links (%u)",
2983                              dentry->d_name.len, dentry->d_name.name,
2984                              inode->i_nlink);
2985         inode->i_version++;
2986         clear_nlink(inode);
2987         /* There's no need to set i_disksize: the fact that i_nlink is
2988          * zero will ensure that the right thing happens during any
2989          * recovery. */
2990         inode->i_size = 0;
2991         ext4_orphan_add(handle, inode);
2992         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2993         ext4_mark_inode_dirty(handle, inode);
2994         ext4_dec_count(handle, dir);
2995         ext4_update_dx_flag(dir);
2996         ext4_mark_inode_dirty(handle, dir);
2997
2998 end_rmdir:
2999         brelse(bh);
3000         if (handle)
3001                 ext4_journal_stop(handle);
3002         return retval;
3003 }
3004
3005 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3006 {
3007         int retval;
3008         struct inode *inode;
3009         struct buffer_head *bh;
3010         struct ext4_dir_entry_2 *de;
3011         handle_t *handle = NULL;
3012
3013         trace_ext4_unlink_enter(dir, dentry);
3014         /* Initialize quotas before so that eventual writes go
3015          * in separate transaction */
3016         retval = dquot_initialize(dir);
3017         if (retval)
3018                 return retval;
3019         retval = dquot_initialize(d_inode(dentry));
3020         if (retval)
3021                 return retval;
3022
3023         retval = -ENOENT;
3024         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3025         if (IS_ERR(bh))
3026                 return PTR_ERR(bh);
3027         if (!bh)
3028                 goto end_unlink;
3029
3030         inode = d_inode(dentry);
3031
3032         retval = -EFSCORRUPTED;
3033         if (le32_to_cpu(de->inode) != inode->i_ino)
3034                 goto end_unlink;
3035
3036         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3037                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3038         if (IS_ERR(handle)) {
3039                 retval = PTR_ERR(handle);
3040                 handle = NULL;
3041                 goto end_unlink;
3042         }
3043
3044         if (IS_DIRSYNC(dir))
3045                 ext4_handle_sync(handle);
3046
3047         if (inode->i_nlink == 0) {
3048                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3049                                    dentry->d_name.len, dentry->d_name.name);
3050                 set_nlink(inode, 1);
3051         }
3052         retval = ext4_delete_entry(handle, dir, de, bh);
3053         if (retval)
3054                 goto end_unlink;
3055         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3056         ext4_update_dx_flag(dir);
3057         ext4_mark_inode_dirty(handle, dir);
3058         drop_nlink(inode);
3059         if (!inode->i_nlink)
3060                 ext4_orphan_add(handle, inode);
3061         inode->i_ctime = ext4_current_time(inode);
3062         ext4_mark_inode_dirty(handle, inode);
3063
3064 end_unlink:
3065         brelse(bh);
3066         if (handle)
3067                 ext4_journal_stop(handle);
3068         trace_ext4_unlink_exit(dentry, retval);
3069         return retval;
3070 }
3071
3072 static int ext4_symlink(struct inode *dir,
3073                         struct dentry *dentry, const char *symname)
3074 {
3075         handle_t *handle;
3076         struct inode *inode;
3077         int err, len = strlen(symname);
3078         int credits;
3079         bool encryption_required;
3080         struct ext4_str disk_link;
3081         struct ext4_encrypted_symlink_data *sd = NULL;
3082
3083         disk_link.len = len + 1;
3084         disk_link.name = (char *) symname;
3085
3086         encryption_required = (ext4_encrypted_inode(dir) ||
3087                                DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3088         if (encryption_required) {
3089                 err = ext4_get_encryption_info(dir);
3090                 if (err)
3091                         return err;
3092                 if (ext4_encryption_info(dir) == NULL)
3093                         return -EPERM;
3094                 disk_link.len = (ext4_fname_encrypted_size(dir, len) +
3095                                  sizeof(struct ext4_encrypted_symlink_data));
3096                 sd = kzalloc(disk_link.len, GFP_KERNEL);
3097                 if (!sd)
3098                         return -ENOMEM;
3099         }
3100
3101         if (disk_link.len > dir->i_sb->s_blocksize) {
3102                 err = -ENAMETOOLONG;
3103                 goto err_free_sd;
3104         }
3105
3106         err = dquot_initialize(dir);
3107         if (err)
3108                 goto err_free_sd;
3109
3110         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3111                 /*
3112                  * For non-fast symlinks, we just allocate inode and put it on
3113                  * orphan list in the first transaction => we need bitmap,
3114                  * group descriptor, sb, inode block, quota blocks, and
3115                  * possibly selinux xattr blocks.
3116                  */
3117                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3118                           EXT4_XATTR_TRANS_BLOCKS;
3119         } else {
3120                 /*
3121                  * Fast symlink. We have to add entry to directory
3122                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3123                  * allocate new inode (bitmap, group descriptor, inode block,
3124                  * quota blocks, sb is already counted in previous macros).
3125                  */
3126                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3127                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3128         }
3129
3130         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3131                                             &dentry->d_name, 0, NULL,
3132                                             EXT4_HT_DIR, credits);
3133         handle = ext4_journal_current_handle();
3134         if (IS_ERR(inode)) {
3135                 if (handle)
3136                         ext4_journal_stop(handle);
3137                 err = PTR_ERR(inode);
3138                 goto err_free_sd;
3139         }
3140
3141         if (encryption_required) {
3142                 struct qstr istr;
3143                 struct ext4_str ostr;
3144
3145                 istr.name = (const unsigned char *) symname;
3146                 istr.len = len;
3147                 ostr.name = sd->encrypted_path;
3148                 ostr.len = disk_link.len;
3149                 err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
3150                 if (err < 0)
3151                         goto err_drop_inode;
3152                 sd->len = cpu_to_le16(ostr.len);
3153                 disk_link.name = (char *) sd;
3154                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3155         }
3156
3157         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3158                 if (!encryption_required)
3159                         inode->i_op = &ext4_symlink_inode_operations;
3160                 inode_nohighmem(inode);
3161                 ext4_set_aops(inode);
3162                 /*
3163                  * We cannot call page_symlink() with transaction started
3164                  * because it calls into ext4_write_begin() which can wait
3165                  * for transaction commit if we are running out of space
3166                  * and thus we deadlock. So we have to stop transaction now
3167                  * and restart it when symlink contents is written.
3168                  *
3169                  * To keep fs consistent in case of crash, we have to put inode
3170                  * to orphan list in the mean time.
3171                  */
3172                 drop_nlink(inode);
3173                 err = ext4_orphan_add(handle, inode);
3174                 ext4_journal_stop(handle);
3175                 handle = NULL;
3176                 if (err)
3177                         goto err_drop_inode;
3178                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3179                 if (err)
3180                         goto err_drop_inode;
3181                 /*
3182                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3183                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3184                  */
3185                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3186                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3187                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3188                 if (IS_ERR(handle)) {
3189                         err = PTR_ERR(handle);
3190                         handle = NULL;
3191                         goto err_drop_inode;
3192                 }
3193                 set_nlink(inode, 1);
3194                 err = ext4_orphan_del(handle, inode);
3195                 if (err)
3196                         goto err_drop_inode;
3197         } else {
3198                 /* clear the extent format for fast symlink */
3199                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3200                 if (!encryption_required) {
3201                         inode->i_op = &ext4_fast_symlink_inode_operations;
3202                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3203                 }
3204                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3205                        disk_link.len);
3206                 inode->i_size = disk_link.len - 1;
3207         }
3208         EXT4_I(inode)->i_disksize = inode->i_size;
3209         err = ext4_add_nondir(handle, dentry, inode);
3210         if (!err && IS_DIRSYNC(dir))
3211                 ext4_handle_sync(handle);
3212
3213         if (handle)
3214                 ext4_journal_stop(handle);
3215         kfree(sd);
3216         return err;
3217 err_drop_inode:
3218         if (handle)
3219                 ext4_journal_stop(handle);
3220         clear_nlink(inode);
3221         unlock_new_inode(inode);
3222         iput(inode);
3223 err_free_sd:
3224         kfree(sd);
3225         return err;
3226 }
3227
3228 static int ext4_link(struct dentry *old_dentry,
3229                      struct inode *dir, struct dentry *dentry)
3230 {
3231         handle_t *handle;
3232         struct inode *inode = d_inode(old_dentry);
3233         int err, retries = 0;
3234
3235         if (inode->i_nlink >= EXT4_LINK_MAX)
3236                 return -EMLINK;
3237         if (ext4_encrypted_inode(dir) &&
3238             !ext4_is_child_context_consistent_with_parent(dir, inode))
3239                 return -EPERM;
3240
3241        if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3242            (!projid_eq(EXT4_I(dir)->i_projid,
3243                        EXT4_I(old_dentry->d_inode)->i_projid)))
3244                 return -EXDEV;
3245
3246         err = dquot_initialize(dir);
3247         if (err)
3248                 return err;
3249
3250 retry:
3251         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3252                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3253                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3254         if (IS_ERR(handle))
3255                 return PTR_ERR(handle);
3256
3257         if (IS_DIRSYNC(dir))
3258                 ext4_handle_sync(handle);
3259
3260         inode->i_ctime = ext4_current_time(inode);
3261         ext4_inc_count(handle, inode);
3262         ihold(inode);
3263
3264         err = ext4_add_entry(handle, dentry, inode);
3265         if (!err) {
3266                 ext4_mark_inode_dirty(handle, inode);
3267                 /* this can happen only for tmpfile being
3268                  * linked the first time
3269                  */
3270                 if (inode->i_nlink == 1)
3271                         ext4_orphan_del(handle, inode);
3272                 d_instantiate(dentry, inode);
3273         } else {
3274                 drop_nlink(inode);
3275                 iput(inode);
3276         }
3277         ext4_journal_stop(handle);
3278         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3279                 goto retry;
3280         return err;
3281 }
3282
3283
3284 /*
3285  * Try to find buffer head where contains the parent block.
3286  * It should be the inode block if it is inlined or the 1st block
3287  * if it is a normal dir.
3288  */
3289 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3290                                         struct inode *inode,
3291                                         int *retval,
3292                                         struct ext4_dir_entry_2 **parent_de,
3293                                         int *inlined)
3294 {
3295         struct buffer_head *bh;
3296
3297         if (!ext4_has_inline_data(inode)) {
3298                 bh = ext4_read_dirblock(inode, 0, EITHER);
3299                 if (IS_ERR(bh)) {
3300                         *retval = PTR_ERR(bh);
3301                         return NULL;
3302                 }
3303                 *parent_de = ext4_next_entry(
3304                                         (struct ext4_dir_entry_2 *)bh->b_data,
3305                                         inode->i_sb->s_blocksize);
3306                 return bh;
3307         }
3308
3309         *inlined = 1;
3310         return ext4_get_first_inline_block(inode, parent_de, retval);
3311 }
3312
3313 struct ext4_renament {
3314         struct inode *dir;
3315         struct dentry *dentry;
3316         struct inode *inode;
3317         bool is_dir;
3318         int dir_nlink_delta;
3319
3320         /* entry for "dentry" */
3321         struct buffer_head *bh;
3322         struct ext4_dir_entry_2 *de;
3323         int inlined;
3324
3325         /* entry for ".." in inode if it's a directory */
3326         struct buffer_head *dir_bh;
3327         struct ext4_dir_entry_2 *parent_de;
3328         int dir_inlined;
3329 };
3330
3331 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3332 {
3333         int retval;
3334
3335         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3336                                               &retval, &ent->parent_de,
3337                                               &ent->dir_inlined);
3338         if (!ent->dir_bh)
3339                 return retval;
3340         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3341                 return -EFSCORRUPTED;
3342         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3343         return ext4_journal_get_write_access(handle, ent->dir_bh);
3344 }
3345
3346 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3347                                   unsigned dir_ino)
3348 {
3349         int retval;
3350
3351         ent->parent_de->inode = cpu_to_le32(dir_ino);
3352         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3353         if (!ent->dir_inlined) {
3354                 if (is_dx(ent->inode)) {
3355                         retval = ext4_handle_dirty_dx_node(handle,
3356                                                            ent->inode,
3357                                                            ent->dir_bh);
3358                 } else {
3359                         retval = ext4_handle_dirty_dirent_node(handle,
3360                                                                ent->inode,
3361                                                                ent->dir_bh);
3362                 }
3363         } else {
3364                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3365         }
3366         if (retval) {
3367                 ext4_std_error(ent->dir->i_sb, retval);
3368                 return retval;
3369         }
3370         return 0;
3371 }
3372
3373 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3374                        unsigned ino, unsigned file_type)
3375 {
3376         int retval;
3377
3378         BUFFER_TRACE(ent->bh, "get write access");
3379         retval = ext4_journal_get_write_access(handle, ent->bh);
3380         if (retval)
3381                 return retval;
3382         ent->de->inode = cpu_to_le32(ino);
3383         if (ext4_has_feature_filetype(ent->dir->i_sb))
3384                 ent->de->file_type = file_type;
3385         ent->dir->i_version++;
3386         ent->dir->i_ctime = ent->dir->i_mtime =
3387                 ext4_current_time(ent->dir);
3388         ext4_mark_inode_dirty(handle, ent->dir);
3389         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3390         if (!ent->inlined) {
3391                 retval = ext4_handle_dirty_dirent_node(handle,
3392                                                        ent->dir, ent->bh);
3393                 if (unlikely(retval)) {
3394                         ext4_std_error(ent->dir->i_sb, retval);
3395                         return retval;
3396                 }
3397         }
3398         brelse(ent->bh);
3399         ent->bh = NULL;
3400
3401         return 0;
3402 }
3403
3404 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3405                                   const struct qstr *d_name)
3406 {
3407         int retval = -ENOENT;
3408         struct buffer_head *bh;
3409         struct ext4_dir_entry_2 *de;
3410
3411         bh = ext4_find_entry(dir, d_name, &de, NULL);
3412         if (IS_ERR(bh))
3413                 return PTR_ERR(bh);
3414         if (bh) {
3415                 retval = ext4_delete_entry(handle, dir, de, bh);
3416                 brelse(bh);
3417         }
3418         return retval;
3419 }
3420
3421 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3422                                int force_reread)
3423 {
3424         int retval;
3425         /*
3426          * ent->de could have moved from under us during htree split, so make
3427          * sure that we are deleting the right entry.  We might also be pointing
3428          * to a stale entry in the unused part of ent->bh so just checking inum
3429          * and the name isn't enough.
3430          */
3431         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3432             ent->de->name_len != ent->dentry->d_name.len ||
3433             strncmp(ent->de->name, ent->dentry->d_name.name,
3434                     ent->de->name_len) ||
3435             force_reread) {
3436                 retval = ext4_find_delete_entry(handle, ent->dir,
3437                                                 &ent->dentry->d_name);
3438         } else {
3439                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3440                 if (retval == -ENOENT) {
3441                         retval = ext4_find_delete_entry(handle, ent->dir,
3442                                                         &ent->dentry->d_name);
3443                 }
3444         }
3445
3446         if (retval) {
3447                 ext4_warning_inode(ent->dir,
3448                                    "Deleting old file: nlink %d, error=%d",
3449                                    ent->dir->i_nlink, retval);
3450         }
3451 }
3452
3453 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3454 {
3455         if (ent->dir_nlink_delta) {
3456                 if (ent->dir_nlink_delta == -1)
3457                         ext4_dec_count(handle, ent->dir);
3458                 else
3459                         ext4_inc_count(handle, ent->dir);
3460                 ext4_mark_inode_dirty(handle, ent->dir);
3461         }
3462 }
3463
3464 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3465                                               int credits, handle_t **h)
3466 {
3467         struct inode *wh;
3468         handle_t *handle;
3469         int retries = 0;
3470
3471         /*
3472          * for inode block, sb block, group summaries,
3473          * and inode bitmap
3474          */
3475         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3476                     EXT4_XATTR_TRANS_BLOCKS + 4);
3477 retry:
3478         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3479                                          &ent->dentry->d_name, 0, NULL,
3480                                          EXT4_HT_DIR, credits);
3481
3482         handle = ext4_journal_current_handle();
3483         if (IS_ERR(wh)) {
3484                 if (handle)
3485                         ext4_journal_stop(handle);
3486                 if (PTR_ERR(wh) == -ENOSPC &&
3487                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3488                         goto retry;
3489         } else {
3490                 *h = handle;
3491                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3492                 wh->i_op = &ext4_special_inode_operations;
3493         }
3494         return wh;
3495 }
3496
3497 /*
3498  * Anybody can rename anything with this: the permission checks are left to the
3499  * higher-level routines.
3500  *
3501  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3502  * while new_{dentry,inode) refers to the destination dentry/inode
3503  * This comes from rename(const char *oldpath, const char *newpath)
3504  */
3505 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3506                        struct inode *new_dir, struct dentry *new_dentry,
3507                        unsigned int flags)
3508 {
3509         handle_t *handle = NULL;
3510         struct ext4_renament old = {
3511                 .dir = old_dir,
3512                 .dentry = old_dentry,
3513                 .inode = d_inode(old_dentry),
3514         };
3515         struct ext4_renament new = {
3516                 .dir = new_dir,
3517                 .dentry = new_dentry,
3518                 .inode = d_inode(new_dentry),
3519         };
3520         int force_reread;
3521         int retval;
3522         struct inode *whiteout = NULL;
3523         int credits;
3524         u8 old_file_type;
3525
3526         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3527             (!projid_eq(EXT4_I(new_dir)->i_projid,
3528                         EXT4_I(old_dentry->d_inode)->i_projid)))
3529                 return -EXDEV;
3530
3531         retval = dquot_initialize(old.dir);
3532         if (retval)
3533                 return retval;
3534         retval = dquot_initialize(new.dir);
3535         if (retval)
3536                 return retval;
3537
3538         /* Initialize quotas before so that eventual writes go
3539          * in separate transaction */
3540         if (new.inode) {
3541                 retval = dquot_initialize(new.inode);
3542                 if (retval)
3543                         return retval;
3544         }
3545
3546         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3547         if (IS_ERR(old.bh))
3548                 return PTR_ERR(old.bh);
3549         /*
3550          *  Check for inode number is _not_ due to possible IO errors.
3551          *  We might rmdir the source, keep it as pwd of some process
3552          *  and merrily kill the link to whatever was created under the
3553          *  same name. Goodbye sticky bit ;-<
3554          */
3555         retval = -ENOENT;
3556         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3557                 goto end_rename;
3558
3559         if ((old.dir != new.dir) &&
3560             ext4_encrypted_inode(new.dir) &&
3561             !ext4_is_child_context_consistent_with_parent(new.dir,
3562                                                           old.inode)) {
3563                 retval = -EPERM;
3564                 goto end_rename;
3565         }
3566
3567         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3568                                  &new.de, &new.inlined);
3569         if (IS_ERR(new.bh)) {
3570                 retval = PTR_ERR(new.bh);
3571                 new.bh = NULL;
3572                 goto end_rename;
3573         }
3574         if (new.bh) {
3575                 if (!new.inode) {
3576                         brelse(new.bh);
3577                         new.bh = NULL;
3578                 }
3579         }
3580         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3581                 ext4_alloc_da_blocks(old.inode);
3582
3583         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3584                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3585         if (!(flags & RENAME_WHITEOUT)) {
3586                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3587                 if (IS_ERR(handle)) {
3588                         retval = PTR_ERR(handle);
3589                         handle = NULL;
3590                         goto end_rename;
3591                 }
3592         } else {
3593                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3594                 if (IS_ERR(whiteout)) {
3595                         retval = PTR_ERR(whiteout);
3596                         whiteout = NULL;
3597                         goto end_rename;
3598                 }
3599         }
3600
3601         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3602                 ext4_handle_sync(handle);
3603
3604         if (S_ISDIR(old.inode->i_mode)) {
3605                 if (new.inode) {
3606                         retval = -ENOTEMPTY;
3607                         if (!ext4_empty_dir(new.inode))
3608                                 goto end_rename;
3609                 } else {
3610                         retval = -EMLINK;
3611                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3612                                 goto end_rename;
3613                 }
3614                 retval = ext4_rename_dir_prepare(handle, &old);
3615                 if (retval)
3616                         goto end_rename;
3617         }
3618         /*
3619          * If we're renaming a file within an inline_data dir and adding or
3620          * setting the new dirent causes a conversion from inline_data to
3621          * extents/blockmap, we need to force the dirent delete code to
3622          * re-read the directory, or else we end up trying to delete a dirent
3623          * from what is now the extent tree root (or a block map).
3624          */
3625         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3626                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3627
3628         old_file_type = old.de->file_type;
3629         if (whiteout) {
3630                 /*
3631                  * Do this before adding a new entry, so the old entry is sure
3632                  * to be still pointing to the valid old entry.
3633                  */
3634                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3635                                      EXT4_FT_CHRDEV);
3636                 if (retval)
3637                         goto end_rename;
3638                 ext4_mark_inode_dirty(handle, whiteout);
3639         }
3640         if (!new.bh) {
3641                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3642                 if (retval)
3643                         goto end_rename;
3644         } else {
3645                 retval = ext4_setent(handle, &new,
3646                                      old.inode->i_ino, old_file_type);
3647                 if (retval)
3648                         goto end_rename;
3649         }
3650         if (force_reread)
3651                 force_reread = !ext4_test_inode_flag(new.dir,
3652                                                      EXT4_INODE_INLINE_DATA);
3653
3654         /*
3655          * Like most other Unix systems, set the ctime for inodes on a
3656          * rename.
3657          */
3658         old.inode->i_ctime = ext4_current_time(old.inode);
3659         ext4_mark_inode_dirty(handle, old.inode);
3660
3661         if (!whiteout) {
3662                 /*
3663                  * ok, that's it
3664                  */
3665                 ext4_rename_delete(handle, &old, force_reread);
3666         }
3667
3668         if (new.inode) {
3669                 ext4_dec_count(handle, new.inode);
3670                 new.inode->i_ctime = ext4_current_time(new.inode);
3671         }
3672         old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3673         ext4_update_dx_flag(old.dir);
3674         if (old.dir_bh) {
3675                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3676                 if (retval)
3677                         goto end_rename;
3678
3679                 ext4_dec_count(handle, old.dir);
3680                 if (new.inode) {
3681                         /* checked ext4_empty_dir above, can't have another
3682                          * parent, ext4_dec_count() won't work for many-linked
3683                          * dirs */
3684                         clear_nlink(new.inode);
3685                 } else {
3686                         ext4_inc_count(handle, new.dir);
3687                         ext4_update_dx_flag(new.dir);
3688                         ext4_mark_inode_dirty(handle, new.dir);
3689                 }
3690         }
3691         ext4_mark_inode_dirty(handle, old.dir);
3692         if (new.inode) {
3693                 ext4_mark_inode_dirty(handle, new.inode);
3694                 if (!new.inode->i_nlink)
3695                         ext4_orphan_add(handle, new.inode);
3696         }
3697         retval = 0;
3698
3699 end_rename:
3700         brelse(old.dir_bh);
3701         brelse(old.bh);
3702         brelse(new.bh);
3703         if (whiteout) {
3704                 if (retval)
3705                         drop_nlink(whiteout);
3706                 unlock_new_inode(whiteout);
3707                 iput(whiteout);
3708         }
3709         if (handle)
3710                 ext4_journal_stop(handle);
3711         return retval;
3712 }
3713
3714 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3715                              struct inode *new_dir, struct dentry *new_dentry)
3716 {
3717         handle_t *handle = NULL;
3718         struct ext4_renament old = {
3719                 .dir = old_dir,
3720                 .dentry = old_dentry,
3721                 .inode = d_inode(old_dentry),
3722         };
3723         struct ext4_renament new = {
3724                 .dir = new_dir,
3725                 .dentry = new_dentry,
3726                 .inode = d_inode(new_dentry),
3727         };
3728         u8 new_file_type;
3729         int retval;
3730
3731         if ((ext4_encrypted_inode(old_dir) ||
3732              ext4_encrypted_inode(new_dir)) &&
3733             (old_dir != new_dir) &&
3734             (!ext4_is_child_context_consistent_with_parent(new_dir,
3735                                                            old.inode) ||
3736              !ext4_is_child_context_consistent_with_parent(old_dir,
3737                                                            new.inode)))
3738                 return -EPERM;
3739
3740         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3741              !projid_eq(EXT4_I(new_dir)->i_projid,
3742                         EXT4_I(old_dentry->d_inode)->i_projid)) ||
3743             (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3744              !projid_eq(EXT4_I(old_dir)->i_projid,
3745                         EXT4_I(new_dentry->d_inode)->i_projid)))
3746                 return -EXDEV;
3747
3748         retval = dquot_initialize(old.dir);
3749         if (retval)
3750                 return retval;
3751         retval = dquot_initialize(new.dir);
3752         if (retval)
3753                 return retval;
3754
3755         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3756                                  &old.de, &old.inlined);
3757         if (IS_ERR(old.bh))
3758                 return PTR_ERR(old.bh);
3759         /*
3760          *  Check for inode number is _not_ due to possible IO errors.
3761          *  We might rmdir the source, keep it as pwd of some process
3762          *  and merrily kill the link to whatever was created under the
3763          *  same name. Goodbye sticky bit ;-<
3764          */
3765         retval = -ENOENT;
3766         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3767                 goto end_rename;
3768
3769         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3770                                  &new.de, &new.inlined);
3771         if (IS_ERR(new.bh)) {
3772                 retval = PTR_ERR(new.bh);
3773                 new.bh = NULL;
3774                 goto end_rename;
3775         }
3776
3777         /* RENAME_EXCHANGE case: old *and* new must both exist */
3778         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3779                 goto end_rename;
3780
3781         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3782                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3783                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3784         if (IS_ERR(handle)) {
3785                 retval = PTR_ERR(handle);
3786                 handle = NULL;
3787                 goto end_rename;
3788         }
3789
3790         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3791                 ext4_handle_sync(handle);
3792
3793         if (S_ISDIR(old.inode->i_mode)) {
3794                 old.is_dir = true;
3795                 retval = ext4_rename_dir_prepare(handle, &old);
3796                 if (retval)
3797                         goto end_rename;
3798         }
3799         if (S_ISDIR(new.inode->i_mode)) {
3800                 new.is_dir = true;
3801                 retval = ext4_rename_dir_prepare(handle, &new);
3802                 if (retval)
3803                         goto end_rename;
3804         }
3805
3806         /*
3807          * Other than the special case of overwriting a directory, parents'
3808          * nlink only needs to be modified if this is a cross directory rename.
3809          */
3810         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3811                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3812                 new.dir_nlink_delta = -old.dir_nlink_delta;
3813                 retval = -EMLINK;
3814                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3815                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3816                         goto end_rename;
3817         }
3818
3819         new_file_type = new.de->file_type;
3820         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3821         if (retval)
3822                 goto end_rename;
3823
3824         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3825         if (retval)
3826                 goto end_rename;
3827
3828         /*
3829          * Like most other Unix systems, set the ctime for inodes on a
3830          * rename.
3831          */
3832         old.inode->i_ctime = ext4_current_time(old.inode);
3833         new.inode->i_ctime = ext4_current_time(new.inode);
3834         ext4_mark_inode_dirty(handle, old.inode);
3835         ext4_mark_inode_dirty(handle, new.inode);
3836
3837         if (old.dir_bh) {
3838                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3839                 if (retval)
3840                         goto end_rename;
3841         }
3842         if (new.dir_bh) {
3843                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3844                 if (retval)
3845                         goto end_rename;
3846         }
3847         ext4_update_dir_count(handle, &old);
3848         ext4_update_dir_count(handle, &new);
3849         retval = 0;
3850
3851 end_rename:
3852         brelse(old.dir_bh);
3853         brelse(new.dir_bh);
3854         brelse(old.bh);
3855         brelse(new.bh);
3856         if (handle)
3857                 ext4_journal_stop(handle);
3858         return retval;
3859 }
3860
3861 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3862                         struct inode *new_dir, struct dentry *new_dentry,
3863                         unsigned int flags)
3864 {
3865         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3866                 return -EINVAL;
3867
3868         if (flags & RENAME_EXCHANGE) {
3869                 return ext4_cross_rename(old_dir, old_dentry,
3870                                          new_dir, new_dentry);
3871         }
3872
3873         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3874 }
3875
3876 /*
3877  * directories can handle most operations...
3878  */
3879 const struct inode_operations ext4_dir_inode_operations = {
3880         .create         = ext4_create,
3881         .lookup         = ext4_lookup,
3882         .link           = ext4_link,
3883         .unlink         = ext4_unlink,
3884         .symlink        = ext4_symlink,
3885         .mkdir          = ext4_mkdir,
3886         .rmdir          = ext4_rmdir,
3887         .mknod          = ext4_mknod,
3888         .tmpfile        = ext4_tmpfile,
3889         .rename2        = ext4_rename2,
3890         .setattr        = ext4_setattr,
3891         .setxattr       = generic_setxattr,
3892         .getxattr       = generic_getxattr,
3893         .listxattr      = ext4_listxattr,
3894         .removexattr    = generic_removexattr,
3895         .get_acl        = ext4_get_acl,
3896         .set_acl        = ext4_set_acl,
3897         .fiemap         = ext4_fiemap,
3898 };
3899
3900 const struct inode_operations ext4_special_inode_operations = {
3901         .setattr        = ext4_setattr,
3902         .setxattr       = generic_setxattr,
3903         .getxattr       = generic_getxattr,
3904         .listxattr      = ext4_listxattr,
3905         .removexattr    = generic_removexattr,
3906         .get_acl        = ext4_get_acl,
3907         .set_acl        = ext4_set_acl,
3908 };