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