fs/ext4/namei.c

   1 /*
   2  *  linux/fs/ext4/namei.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/namei.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  *  Directory entry file type support and forward compatibility hooks
  18  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  19  *  Hash Tree Directory indexing (c)
  20  *      Daniel Phillips, 2001
  21  *  Hash Tree Directory indexing porting
  22  *      Christopher Li, 2002
  23  *  Hash Tree Directory indexing cleanup
  24  *      Theodore Ts'o, 2002
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/time.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/stat.h>
  32 #include <linux/string.h>
  33 #include <linux/quotaops.h>
  34 #include <linux/buffer_head.h>
  35 #include <linux/bio.h>
  36 #include "ext4.h"
  37 #include "ext4_jbd2.h"
  38
  39 #include "xattr.h"
  40 #include "acl.h"
  41
  42 #include <trace/events/ext4.h>
  43 /*
  44  * define how far ahead to read directories while searching them.
  45  */
  46 #define NAMEI_RA_CHUNKS  2
  47 #define NAMEI_RA_BLOCKS  4
  48 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  49
  50 static struct buffer_head *ext4_append(handle_t *handle,
  51                                         struct inode *inode,
  52                                         ext4_lblk_t *block)
  53 {
  54         struct buffer_head *bh;
  55         int err;
  56
  57         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  58                      ((inode->i_size >> 10) >=
  59                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
  60                 return ERR_PTR(-ENOSPC);
  61
  62         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  63
  64         bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
  65         if (IS_ERR(bh))
  66                 return bh;
  67         inode->i_size += inode->i_sb->s_blocksize;
  68         EXT4_I(inode)->i_disksize = inode->i_size;
  69         BUFFER_TRACE(bh, "get_write_access");
  70         err = ext4_journal_get_write_access(handle, bh);
  71         if (err) {
  72                 brelse(bh);
  73                 ext4_std_error(inode->i_sb, err);
  74                 return ERR_PTR(err);
  75         }
  76         return bh;
  77 }
  78
  79 static int ext4_dx_csum_verify(struct inode *inode,
  80                                struct ext4_dir_entry *dirent);
  81
  82 typedef enum {
  83         EITHER, INDEX, DIRENT
  84 } dirblock_type_t;
  85
  86 #define ext4_read_dirblock(inode, block, type) \
  87         __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
  88
  89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
  90                                                 ext4_lblk_t block,
  91                                                 dirblock_type_t type,
  92                                                 const char *func,
  93                                                 unsigned int line)
  94 {
  95         struct buffer_head *bh;
  96         struct ext4_dir_entry *dirent;
  97         int is_dx_block = 0;
  98
  99         bh = ext4_bread(NULL, inode, block, 0);
 100         if (IS_ERR(bh)) {
 101                 __ext4_warning(inode->i_sb, func, line,
 102                                "inode #%lu: lblock %lu: comm %s: "
 103                                "error %ld reading directory block",
 104                                inode->i_ino, (unsigned long)block,
 105                                current->comm, PTR_ERR(bh));
 106
 107                 return bh;
 108         }
 109         if (!bh) {
 110                 ext4_error_inode(inode, func, line, block,
 111                                  "Directory hole found");
 112                 return ERR_PTR(-EFSCORRUPTED);
 113         }
 114         dirent = (struct ext4_dir_entry *) bh->b_data;
 115         /* Determine whether or not we have an index block */
 116         if (is_dx(inode)) {
 117                 if (block == 0)
 118                         is_dx_block = 1;
 119                 else if (ext4_rec_len_from_disk(dirent->rec_len,
 120                                                 inode->i_sb->s_blocksize) ==
 121                          inode->i_sb->s_blocksize)
 122                         is_dx_block = 1;
 123         }
 124         if (!is_dx_block && type == INDEX) {
 125                 ext4_error_inode(inode, func, line, block,
 126                        "directory leaf block found instead of index block");
 127                 return ERR_PTR(-EFSCORRUPTED);
 128         }
 129         if (!ext4_has_metadata_csum(inode->i_sb) ||
 130             buffer_verified(bh))
 131                 return bh;
 132
 133         /*
 134          * An empty leaf block can get mistaken for a index block; for
 135          * this reason, we can only check the index checksum when the
 136          * caller is sure it should be an index block.
 137          */
 138         if (is_dx_block && type == INDEX) {
 139                 if (ext4_dx_csum_verify(inode, dirent))
 140                         set_buffer_verified(bh);
 141                 else {
 142                         ext4_error_inode(inode, func, line, block,
 143                                          "Directory index failed checksum");
 144                         brelse(bh);
 145                         return ERR_PTR(-EFSBADCRC);
 146                 }
 147         }
 148         if (!is_dx_block) {
 149                 if (ext4_dirent_csum_verify(inode, dirent))
 150                         set_buffer_verified(bh);
 151                 else {
 152                         ext4_error_inode(inode, func, line, block,
 153                                          "Directory block failed checksum");
 154                         brelse(bh);
 155                         return ERR_PTR(-EFSBADCRC);
 156                 }
 157         }
 158         return bh;
 159 }
 160
 161 #ifndef assert
 162 #define assert(test) J_ASSERT(test)
 163 #endif
 164
 165 #ifdef DX_DEBUG
 166 #define dxtrace(command) command
 167 #else
 168 #define dxtrace(command)
 169 #endif
 170
 171 struct fake_dirent
 172 {
 173         __le32 inode;
 174         __le16 rec_len;
 175         u8 name_len;
 176         u8 file_type;
 177 };
 178
 179 struct dx_countlimit
 180 {
 181         __le16 limit;
 182         __le16 count;
 183 };
 184
 185 struct dx_entry
 186 {
 187         __le32 hash;
 188         __le32 block;
 189 };
 190
 191 /*
 192  * dx_root_info is laid out so that if it should somehow get overlaid by a
 193  * dirent the two low bits of the hash version will be zero.  Therefore, the
 194  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 195  */
 196
 197 struct dx_root
 198 {
 199         struct fake_dirent dot;
 200         char dot_name[4];
 201         struct fake_dirent dotdot;
 202         char dotdot_name[4];
 203         struct dx_root_info
 204         {
 205                 __le32 reserved_zero;
 206                 u8 hash_version;
 207                 u8 info_length; /* 8 */
 208                 u8 indirect_levels;
 209                 u8 unused_flags;
 210         }
 211         info;
 212         struct dx_entry entries[0];
 213 };
 214
 215 struct dx_node
 216 {
 217         struct fake_dirent fake;
 218         struct dx_entry entries[0];
 219 };
 220
 221
 222 struct dx_frame
 223 {
 224         struct buffer_head *bh;
 225         struct dx_entry *entries;
 226         struct dx_entry *at;
 227 };
 228
 229 struct dx_map_entry
 230 {
 231         u32 hash;
 232         u16 offs;
 233         u16 size;
 234 };
 235
 236 /*
 237  * This goes at the end of each htree block.
 238  */
 239 struct dx_tail {
 240         u32 dt_reserved;
 241         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 242 };
 243
 244 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 245 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 246 static inline unsigned dx_get_hash(struct dx_entry *entry);
 247 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 248 static unsigned dx_get_count(struct dx_entry *entries);
 249 static unsigned dx_get_limit(struct dx_entry *entries);
 250 static void dx_set_count(struct dx_entry *entries, unsigned value);
 251 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 252 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 253 static unsigned dx_node_limit(struct inode *dir);
 254 static struct dx_frame *dx_probe(struct ext4_filename *fname,
 255                                  struct inode *dir,
 256                                  struct dx_hash_info *hinfo,
 257                                  struct dx_frame *frame);
 258 static void dx_release(struct dx_frame *frames);
 259 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 260                        unsigned blocksize, struct dx_hash_info *hinfo,
 261                        struct dx_map_entry map[]);
 262 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 263 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 264                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 265 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 266 static void dx_insert_block(struct dx_frame *frame,
 267                                         u32 hash, ext4_lblk_t block);
 268 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 269                                  struct dx_frame *frame,
 270                                  struct dx_frame *frames,
 271                                  __u32 *start_hash);
 272 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 273                 struct ext4_filename *fname,
 274                 struct ext4_dir_entry_2 **res_dir);
 275 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 276                              struct inode *dir, struct inode *inode);
 277
 278 /* checksumming functions */
 279 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 280                             unsigned int blocksize)
 281 {
 282         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 283         t->det_rec_len = ext4_rec_len_to_disk(
 284                         sizeof(struct ext4_dir_entry_tail), blocksize);
 285         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 286 }
 287
 288 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 289 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 290                                                    struct ext4_dir_entry *de)
 291 {
 292         struct ext4_dir_entry_tail *t;
 293
 294 #ifdef PARANOID
 295         struct ext4_dir_entry *d, *top;
 296
 297         d = de;
 298         top = (struct ext4_dir_entry *)(((void *)de) +
 299                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 300                 sizeof(struct ext4_dir_entry_tail)));
 301         while (d < top && d->rec_len)
 302                 d = (struct ext4_dir_entry *)(((void *)d) +
 303                     le16_to_cpu(d->rec_len));
 304
 305         if (d != top)
 306                 return NULL;
 307
 308         t = (struct ext4_dir_entry_tail *)d;
 309 #else
 310         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 311 #endif
 312
 313         if (t->det_reserved_zero1 ||
 314             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 315             t->det_reserved_zero2 ||
 316             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 317                 return NULL;
 318
 319         return t;
 320 }
 321
 322 static __le32 ext4_dirent_csum(struct inode *inode,
 323                                struct ext4_dir_entry *dirent, int size)
 324 {
 325         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 326         struct ext4_inode_info *ei = EXT4_I(inode);
 327         __u32 csum;
 328
 329         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 330         return cpu_to_le32(csum);
 331 }
 332
 333 #define warn_no_space_for_csum(inode)                                   \
 334         __warn_no_space_for_csum((inode), __func__, __LINE__)
 335
 336 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
 337                                      unsigned int line)
 338 {
 339         __ext4_warning_inode(inode, func, line,
 340                 "No space for directory leaf checksum. Please run e2fsck -D.");
 341 }
 342
 343 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 344 {
 345         struct ext4_dir_entry_tail *t;
 346
 347         if (!ext4_has_metadata_csum(inode->i_sb))
 348                 return 1;
 349
 350         t = get_dirent_tail(inode, dirent);
 351         if (!t) {
 352                 warn_no_space_for_csum(inode);
 353                 return 0;
 354         }
 355
 356         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 357                                                 (void *)t - (void *)dirent))
 358                 return 0;
 359
 360         return 1;
 361 }
 362
 363 static void ext4_dirent_csum_set(struct inode *inode,
 364                                  struct ext4_dir_entry *dirent)
 365 {
 366         struct ext4_dir_entry_tail *t;
 367
 368         if (!ext4_has_metadata_csum(inode->i_sb))
 369                 return;
 370
 371         t = get_dirent_tail(inode, dirent);
 372         if (!t) {
 373                 warn_no_space_for_csum(inode);
 374                 return;
 375         }
 376
 377         t->det_checksum = ext4_dirent_csum(inode, dirent,
 378                                            (void *)t - (void *)dirent);
 379 }
 380
 381 int ext4_handle_dirty_dirent_node(handle_t *handle,
 382                                   struct inode *inode,
 383                                   struct buffer_head *bh)
 384 {
 385         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 386         return ext4_handle_dirty_metadata(handle, inode, bh);
 387 }
 388
 389 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 390                                                struct ext4_dir_entry *dirent,
 391                                                int *offset)
 392 {
 393         struct ext4_dir_entry *dp;
 394         struct dx_root_info *root;
 395         int count_offset;
 396
 397         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 398                 count_offset = 8;
 399         else if (le16_to_cpu(dirent->rec_len) == 12) {
 400                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 401                 if (le16_to_cpu(dp->rec_len) !=
 402                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 403                         return NULL;
 404                 root = (struct dx_root_info *)(((void *)dp + 12));
 405                 if (root->reserved_zero ||
 406                     root->info_length != sizeof(struct dx_root_info))
 407                         return NULL;
 408                 count_offset = 32;
 409         } else
 410                 return NULL;
 411
 412         if (offset)
 413                 *offset = count_offset;
 414         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 415 }
 416
 417 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 418                            int count_offset, int count, struct dx_tail *t)
 419 {
 420         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 421         struct ext4_inode_info *ei = EXT4_I(inode);
 422         __u32 csum;
 423         int size;
 424         __u32 dummy_csum = 0;
 425         int offset = offsetof(struct dx_tail, dt_checksum);
 426
 427         size = count_offset + (count * sizeof(struct dx_entry));
 428         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 429         csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
 430         csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
 431
 432         return cpu_to_le32(csum);
 433 }
 434
 435 static int ext4_dx_csum_verify(struct inode *inode,
 436                                struct ext4_dir_entry *dirent)
 437 {
 438         struct dx_countlimit *c;
 439         struct dx_tail *t;
 440         int count_offset, limit, count;
 441
 442         if (!ext4_has_metadata_csum(inode->i_sb))
 443                 return 1;
 444
 445         c = get_dx_countlimit(inode, dirent, &count_offset);
 446         if (!c) {
 447                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 448                 return 0;
 449         }
 450         limit = le16_to_cpu(c->limit);
 451         count = le16_to_cpu(c->count);
 452         if (count_offset + (limit * sizeof(struct dx_entry)) >
 453             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 454                 warn_no_space_for_csum(inode);
 455                 return 0;
 456         }
 457         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 458
 459         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 460                                             count, t))
 461                 return 0;
 462         return 1;
 463 }
 464
 465 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 466 {
 467         struct dx_countlimit *c;
 468         struct dx_tail *t;
 469         int count_offset, limit, count;
 470
 471         if (!ext4_has_metadata_csum(inode->i_sb))
 472                 return;
 473
 474         c = get_dx_countlimit(inode, dirent, &count_offset);
 475         if (!c) {
 476                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 477                 return;
 478         }
 479         limit = le16_to_cpu(c->limit);
 480         count = le16_to_cpu(c->count);
 481         if (count_offset + (limit * sizeof(struct dx_entry)) >
 482             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 483                 warn_no_space_for_csum(inode);
 484                 return;
 485         }
 486         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 487
 488         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 489 }
 490
 491 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 492                                             struct inode *inode,
 493                                             struct buffer_head *bh)
 494 {
 495         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 496         return ext4_handle_dirty_metadata(handle, inode, bh);
 497 }
 498
 499 /*
 500  * p is at least 6 bytes before the end of page
 501  */
 502 static inline struct ext4_dir_entry_2 *
 503 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 504 {
 505         return (struct ext4_dir_entry_2 *)((char *)p +
 506                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 507 }
 508
 509 /*
 510  * Future: use high four bits of block for coalesce-on-delete flags
 511  * Mask them off for now.
 512  */
 513
 514 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 515 {
 516         return le32_to_cpu(entry->block) & 0x0fffffff;
 517 }
 518
 519 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 520 {
 521         entry->block = cpu_to_le32(value);
 522 }
 523
 524 static inline unsigned dx_get_hash(struct dx_entry *entry)
 525 {
 526         return le32_to_cpu(entry->hash);
 527 }
 528
 529 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 530 {
 531         entry->hash = cpu_to_le32(value);
 532 }
 533
 534 static inline unsigned dx_get_count(struct dx_entry *entries)
 535 {
 536         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 537 }
 538
 539 static inline unsigned dx_get_limit(struct dx_entry *entries)
 540 {
 541         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 542 }
 543
 544 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 545 {
 546         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 547 }
 548
 549 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 550 {
 551         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 552 }
 553
 554 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 555 {
 556         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 557                 EXT4_DIR_REC_LEN(2) - infosize;
 558
 559         if (ext4_has_metadata_csum(dir->i_sb))
 560                 entry_space -= sizeof(struct dx_tail);
 561         return entry_space / sizeof(struct dx_entry);
 562 }
 563
 564 static inline unsigned dx_node_limit(struct inode *dir)
 565 {
 566         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 567
 568         if (ext4_has_metadata_csum(dir->i_sb))
 569                 entry_space -= sizeof(struct dx_tail);
 570         return entry_space / sizeof(struct dx_entry);
 571 }
 572
 573 /*
 574  * Debug
 575  */
 576 #ifdef DX_DEBUG
 577 static void dx_show_index(char * label, struct dx_entry *entries)
 578 {
 579         int i, n = dx_get_count (entries);
 580         printk(KERN_DEBUG "%s index", label);
 581         for (i = 0; i < n; i++) {
 582                 printk(KERN_CONT " %x->%lu",
 583                        i ? dx_get_hash(entries + i) : 0,
 584                        (unsigned long)dx_get_block(entries + i));
 585         }
 586         printk(KERN_CONT "\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 fscrypt_str fname_crypto_str =
 616                                         FSTR_INIT(NULL, 0);
 617                                 int res = 0;
 618
 619                                 name  = de->name;
 620                                 len = de->name_len;
 621                                 if (ext4_encrypted_inode(dir))
 622                                         res = fscrypt_get_encryption_info(dir);
 623                                 if (res) {
 624                                         printk(KERN_WARNING "Error setting up"
 625                                                " fname crypto: %d\n", res);
 626                                 }
 627                                 if (!fscrypt_has_encryption_key(dir)) {
 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                                         struct fscrypt_str de_name =
 637                                                 FSTR_INIT(name, len);
 638
 639                                         /* Directory is encrypted */
 640                                         res = fscrypt_fname_alloc_buffer(
 641                                                 dir, len,
 642                                                 &fname_crypto_str);
 643                                         if (res)
 644                                                 printk(KERN_WARNING "Error "
 645                                                         "allocating crypto "
 646                                                         "buffer--skipping "
 647                                                         "crypto\n");
 648                                         res = fscrypt_fname_disk_to_usr(dir,
 649                                                 0, 0, &de_name,
 650                                                 &fname_crypto_str);
 651                                         if (res) {
 652                                                 printk(KERN_WARNING "Error "
 653                                                         "converting filename "
 654                                                         "from disk to usr"
 655                                                         "\n");
 656                                                 name = "??";
 657                                                 len = 2;
 658                                         } else {
 659                                                 name = fname_crypto_str.name;
 660                                                 len = fname_crypto_str.len;
 661                                         }
 662                                         ext4fs_dirhash(de->name, de->name_len,
 663                                                        &h);
 664                                         printk("%*.s:(E)%x.%u ", len, name,
 665                                                h.hash, (unsigned) ((char *) de
 666                                                                    - base));
 667                                         fscrypt_fname_free_buffer(
 668                                                         &fname_crypto_str);
 669                                 }
 670 #else
 671                                 int len = de->name_len;
 672                                 char *name = de->name;
 673                                 ext4fs_dirhash(de->name, de->name_len, &h);
 674                                 printk("%*.s:%x.%u ", len, name, h.hash,
 675                                        (unsigned) ((char *) de - base));
 676 #endif
 677                         }
 678                         space += EXT4_DIR_REC_LEN(de->name_len);
 679                         names++;
 680                 }
 681                 de = ext4_next_entry(de, size);
 682         }
 683         printk(KERN_CONT "(%i)\n", names);
 684         return (struct stats) { names, space, 1 };
 685 }
 686
 687 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 688                              struct dx_entry *entries, int levels)
 689 {
 690         unsigned blocksize = dir->i_sb->s_blocksize;
 691         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 692         unsigned bcount = 0;
 693         struct buffer_head *bh;
 694         printk("%i indexed blocks...\n", count);
 695         for (i = 0; i < count; i++, entries++)
 696         {
 697                 ext4_lblk_t block = dx_get_block(entries);
 698                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 699                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 700                 struct stats stats;
 701                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 702                 bh = ext4_bread(NULL,dir, block, 0);
 703                 if (!bh || IS_ERR(bh))
 704                         continue;
 705                 stats = levels?
 706                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 707                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 708                         bh->b_data, blocksize, 0);
 709                 names += stats.names;
 710                 space += stats.space;
 711                 bcount += stats.bcount;
 712                 brelse(bh);
 713         }
 714         if (bcount)
 715                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 716                        levels ? "" : "   ", names, space/bcount,
 717                        (space/bcount)*100/blocksize);
 718         return (struct stats) { names, space, bcount};
 719 }
 720 #endif /* DX_DEBUG */
 721
 722 /*
 723  * Probe for a directory leaf block to search.
 724  *
 725  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 726  * error in the directory index, and the caller should fall back to
 727  * searching the directory normally.  The callers of dx_probe **MUST**
 728  * check for this error code, and make sure it never gets reflected
 729  * back to userspace.
 730  */
 731 static struct dx_frame *
 732 dx_probe(struct ext4_filename *fname, struct inode *dir,
 733          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 734 {
 735         unsigned count, indirect;
 736         struct dx_entry *at, *entries, *p, *q, *m;
 737         struct dx_root *root;
 738         struct dx_frame *frame = frame_in;
 739         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 740         u32 hash;
 741
 742         memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
 743         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 744         if (IS_ERR(frame->bh))
 745                 return (struct dx_frame *) frame->bh;
 746
 747         root = (struct dx_root *) frame->bh->b_data;
 748         if (root->info.hash_version != DX_HASH_TEA &&
 749             root->info.hash_version != DX_HASH_HALF_MD4 &&
 750             root->info.hash_version != DX_HASH_LEGACY) {
 751                 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
 752                                    root->info.hash_version);
 753                 goto fail;
 754         }
 755         if (fname)
 756                 hinfo = &fname->hinfo;
 757         hinfo->hash_version = root->info.hash_version;
 758         if (hinfo->hash_version <= DX_HASH_TEA)
 759                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 760         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 761         if (fname && fname_name(fname))
 762                 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
 763         hash = hinfo->hash;
 764
 765         if (root->info.unused_flags & 1) {
 766                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
 767                                    root->info.unused_flags);
 768                 goto fail;
 769         }
 770
 771         indirect = root->info.indirect_levels;
 772         if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
 773                 ext4_warning(dir->i_sb,
 774                              "Directory (ino: %lu) htree depth %#06x exceed"
 775                              "supported value", dir->i_ino,
 776                              ext4_dir_htree_level(dir->i_sb));
 777                 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
 778                         ext4_warning(dir->i_sb, "Enable large directory "
 779                                                 "feature to access it");
 780                 }
 781                 goto fail;
 782         }
 783
 784         entries = (struct dx_entry *)(((char *)&root->info) +
 785                                       root->info.info_length);
 786
 787         if (dx_get_limit(entries) != dx_root_limit(dir,
 788                                                    root->info.info_length)) {
 789                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 790                                    dx_get_limit(entries),
 791                                    dx_root_limit(dir, root->info.info_length));
 792                 goto fail;
 793         }
 794
 795         dxtrace(printk("Look up %x", hash));
 796         while (1) {
 797                 count = dx_get_count(entries);
 798                 if (!count || count > dx_get_limit(entries)) {
 799                         ext4_warning_inode(dir,
 800                                            "dx entry: count %u beyond limit %u",
 801                                            count, dx_get_limit(entries));
 802                         goto fail;
 803                 }
 804
 805                 p = entries + 1;
 806                 q = entries + count - 1;
 807                 while (p <= q) {
 808                         m = p + (q - p) / 2;
 809                         dxtrace(printk(KERN_CONT "."));
 810                         if (dx_get_hash(m) > hash)
 811                                 q = m - 1;
 812                         else
 813                                 p = m + 1;
 814                 }
 815
 816                 if (0) { // linear search cross check
 817                         unsigned n = count - 1;
 818                         at = entries;
 819                         while (n--)
 820                         {
 821                                 dxtrace(printk(KERN_CONT ","));
 822                                 if (dx_get_hash(++at) > hash)
 823                                 {
 824                                         at--;
 825                                         break;
 826                                 }
 827                         }
 828                         assert (at == p - 1);
 829                 }
 830
 831                 at = p - 1;
 832                 dxtrace(printk(KERN_CONT " %x->%u\n",
 833                                at == entries ? 0 : dx_get_hash(at),
 834                                dx_get_block(at)));
 835                 frame->entries = entries;
 836                 frame->at = at;
 837                 if (!indirect--)
 838                         return frame;
 839                 frame++;
 840                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 841                 if (IS_ERR(frame->bh)) {
 842                         ret_err = (struct dx_frame *) frame->bh;
 843                         frame->bh = NULL;
 844                         goto fail;
 845                 }
 846                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 847
 848                 if (dx_get_limit(entries) != dx_node_limit(dir)) {
 849                         ext4_warning_inode(dir,
 850                                 "dx entry: limit %u != node limit %u",
 851                                 dx_get_limit(entries), dx_node_limit(dir));
 852                         goto fail;
 853                 }
 854         }
 855 fail:
 856         while (frame >= frame_in) {
 857                 brelse(frame->bh);
 858                 frame--;
 859         }
 860
 861         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 862                 ext4_warning_inode(dir,
 863                         "Corrupt directory, running e2fsck is recommended");
 864         return ret_err;
 865 }
 866
 867 static void dx_release(struct dx_frame *frames)
 868 {
 869         struct dx_root_info *info;
 870         int i;
 871
 872         if (frames[0].bh == NULL)
 873                 return;
 874
 875         info = &((struct dx_root *)frames[0].bh->b_data)->info;
 876         for (i = 0; i <= info->indirect_levels; i++) {
 877                 if (frames[i].bh == NULL)
 878                         break;
 879                 brelse(frames[i].bh);
 880                 frames[i].bh = NULL;
 881         }
 882 }
 883
 884 /*
 885  * This function increments the frame pointer to search the next leaf
 886  * block, and reads in the necessary intervening nodes if the search
 887  * should be necessary.  Whether or not the search is necessary is
 888  * controlled by the hash parameter.  If the hash value is even, then
 889  * the search is only continued if the next block starts with that
 890  * hash value.  This is used if we are searching for a specific file.
 891  *
 892  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 893  *
 894  * This function returns 1 if the caller should continue to search,
 895  * or 0 if it should not.  If there is an error reading one of the
 896  * index blocks, it will a negative error code.
 897  *
 898  * If start_hash is non-null, it will be filled in with the starting
 899  * hash of the next page.
 900  */
 901 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 902                                  struct dx_frame *frame,
 903                                  struct dx_frame *frames,
 904                                  __u32 *start_hash)
 905 {
 906         struct dx_frame *p;
 907         struct buffer_head *bh;
 908         int num_frames = 0;
 909         __u32 bhash;
 910
 911         p = frame;
 912         /*
 913          * Find the next leaf page by incrementing the frame pointer.
 914          * If we run out of entries in the interior node, loop around and
 915          * increment pointer in the parent node.  When we break out of
 916          * this loop, num_frames indicates the number of interior
 917          * nodes need to be read.
 918          */
 919         while (1) {
 920                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 921                         break;
 922                 if (p == frames)
 923                         return 0;
 924                 num_frames++;
 925                 p--;
 926         }
 927
 928         /*
 929          * If the hash is 1, then continue only if the next page has a
 930          * continuation hash of any value.  This is used for readdir
 931          * handling.  Otherwise, check to see if the hash matches the
 932          * desired contiuation hash.  If it doesn't, return since
 933          * there's no point to read in the successive index pages.
 934          */
 935         bhash = dx_get_hash(p->at);
 936         if (start_hash)
 937                 *start_hash = bhash;
 938         if ((hash & 1) == 0) {
 939                 if ((bhash & ~1) != hash)
 940                         return 0;
 941         }
 942         /*
 943          * If the hash is HASH_NB_ALWAYS, we always go to the next
 944          * block so no check is necessary
 945          */
 946         while (num_frames--) {
 947                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 948                 if (IS_ERR(bh))
 949                         return PTR_ERR(bh);
 950                 p++;
 951                 brelse(p->bh);
 952                 p->bh = bh;
 953                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 954         }
 955         return 1;
 956 }
 957
 958
 959 /*
 960  * This function fills a red-black tree with information from a
 961  * directory block.  It returns the number directory entries loaded
 962  * into the tree.  If there is an error it is returned in err.
 963  */
 964 static int htree_dirblock_to_tree(struct file *dir_file,
 965                                   struct inode *dir, ext4_lblk_t block,
 966                                   struct dx_hash_info *hinfo,
 967                                   __u32 start_hash, __u32 start_minor_hash)
 968 {
 969         struct buffer_head *bh;
 970         struct ext4_dir_entry_2 *de, *top;
 971         int err = 0, count = 0;
 972         struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
 973
 974         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 975                                                         (unsigned long)block));
 976         bh = ext4_read_dirblock(dir, block, DIRENT);
 977         if (IS_ERR(bh))
 978                 return PTR_ERR(bh);
 979
 980         de = (struct ext4_dir_entry_2 *) bh->b_data;
 981         top = (struct ext4_dir_entry_2 *) ((char *) de +
 982                                            dir->i_sb->s_blocksize -
 983                                            EXT4_DIR_REC_LEN(0));
 984 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 985         /* Check if the directory is encrypted */
 986         if (ext4_encrypted_inode(dir)) {
 987                 err = fscrypt_get_encryption_info(dir);
 988                 if (err < 0) {
 989                         brelse(bh);
 990                         return err;
 991                 }
 992                 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
 993                                                      &fname_crypto_str);
 994                 if (err < 0) {
 995                         brelse(bh);
 996                         return err;
 997                 }
 998         }
 999 #endif
1000         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1001                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1002                                 bh->b_data, bh->b_size,
1003                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1004                                          + ((char *)de - bh->b_data))) {
1005                         /* silently ignore the rest of the block */
1006                         break;
1007                 }
1008                 ext4fs_dirhash(de->name, de->name_len, hinfo);
1009                 if ((hinfo->hash < start_hash) ||
1010                     ((hinfo->hash == start_hash) &&
1011                      (hinfo->minor_hash < start_minor_hash)))
1012                         continue;
1013                 if (de->inode == 0)
1014                         continue;
1015                 if (!ext4_encrypted_inode(dir)) {
1016                         tmp_str.name = de->name;
1017                         tmp_str.len = de->name_len;
1018                         err = ext4_htree_store_dirent(dir_file,
1019                                    hinfo->hash, hinfo->minor_hash, de,
1020                                    &tmp_str);
1021                 } else {
1022                         int save_len = fname_crypto_str.len;
1023                         struct fscrypt_str de_name = FSTR_INIT(de->name,
1024                                                                 de->name_len);
1025
1026                         /* Directory is encrypted */
1027                         err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1028                                         hinfo->minor_hash, &de_name,
1029                                         &fname_crypto_str);
1030                         if (err) {
1031                                 count = err;
1032                                 goto errout;
1033                         }
1034                         err = ext4_htree_store_dirent(dir_file,
1035                                    hinfo->hash, hinfo->minor_hash, de,
1036                                         &fname_crypto_str);
1037                         fname_crypto_str.len = save_len;
1038                 }
1039                 if (err != 0) {
1040                         count = err;
1041                         goto errout;
1042                 }
1043                 count++;
1044         }
1045 errout:
1046         brelse(bh);
1047 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1048         fscrypt_fname_free_buffer(&fname_crypto_str);
1049 #endif
1050         return count;
1051 }
1052
1053
1054 /*
1055  * This function fills a red-black tree with information from a
1056  * directory.  We start scanning the directory in hash order, starting
1057  * at start_hash and start_minor_hash.
1058  *
1059  * This function returns the number of entries inserted into the tree,
1060  * or a negative error code.
1061  */
1062 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1063                          __u32 start_minor_hash, __u32 *next_hash)
1064 {
1065         struct dx_hash_info hinfo;
1066         struct ext4_dir_entry_2 *de;
1067         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1068         struct inode *dir;
1069         ext4_lblk_t block;
1070         int count = 0;
1071         int ret, err;
1072         __u32 hashval;
1073         struct fscrypt_str tmp_str;
1074
1075         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1076                        start_hash, start_minor_hash));
1077         dir = file_inode(dir_file);
1078         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1079                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1080                 if (hinfo.hash_version <= DX_HASH_TEA)
1081                         hinfo.hash_version +=
1082                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1083                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1084                 if (ext4_has_inline_data(dir)) {
1085                         int has_inline_data = 1;
1086                         count = htree_inlinedir_to_tree(dir_file, dir, 0,
1087                                                         &hinfo, start_hash,
1088                                                         start_minor_hash,
1089                                                         &has_inline_data);
1090                         if (has_inline_data) {
1091                                 *next_hash = ~0;
1092                                 return count;
1093                         }
1094                 }
1095                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1096                                                start_hash, start_minor_hash);
1097                 *next_hash = ~0;
1098                 return count;
1099         }
1100         hinfo.hash = start_hash;
1101         hinfo.minor_hash = 0;
1102         frame = dx_probe(NULL, dir, &hinfo, frames);
1103         if (IS_ERR(frame))
1104                 return PTR_ERR(frame);
1105
1106         /* Add '.' and '..' from the htree header */
1107         if (!start_hash && !start_minor_hash) {
1108                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1109                 tmp_str.name = de->name;
1110                 tmp_str.len = de->name_len;
1111                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1112                                               de, &tmp_str);
1113                 if (err != 0)
1114                         goto errout;
1115                 count++;
1116         }
1117         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1118                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1119                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1120                 tmp_str.name = de->name;
1121                 tmp_str.len = de->name_len;
1122                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1123                                               de, &tmp_str);
1124                 if (err != 0)
1125                         goto errout;
1126                 count++;
1127         }
1128
1129         while (1) {
1130                 if (fatal_signal_pending(current)) {
1131                         err = -ERESTARTSYS;
1132                         goto errout;
1133                 }
1134                 cond_resched();
1135                 block = dx_get_block(frame->at);
1136                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1137                                              start_hash, start_minor_hash);
1138                 if (ret < 0) {
1139                         err = ret;
1140                         goto errout;
1141                 }
1142                 count += ret;
1143                 hashval = ~0;
1144                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1145                                             frame, frames, &hashval);
1146                 *next_hash = hashval;
1147                 if (ret < 0) {
1148                         err = ret;
1149                         goto errout;
1150                 }
1151                 /*
1152                  * Stop if:  (a) there are no more entries, or
1153                  * (b) we have inserted at least one entry and the
1154                  * next hash value is not a continuation
1155                  */
1156                 if ((ret == 0) ||
1157                     (count && ((hashval & 1) == 0)))
1158                         break;
1159         }
1160         dx_release(frames);
1161         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1162                        "next hash: %x\n", count, *next_hash));
1163         return count;
1164 errout:
1165         dx_release(frames);
1166         return (err);
1167 }
1168
1169 static inline int search_dirblock(struct buffer_head *bh,
1170                                   struct inode *dir,
1171                                   struct ext4_filename *fname,
1172                                   unsigned int offset,
1173                                   struct ext4_dir_entry_2 **res_dir)
1174 {
1175         return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1176                                fname, offset, res_dir);
1177 }
1178
1179 /*
1180  * Directory block splitting, compacting
1181  */
1182
1183 /*
1184  * Create map of hash values, offsets, and sizes, stored at end of block.
1185  * Returns number of entries mapped.
1186  */
1187 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1188                        unsigned blocksize, struct dx_hash_info *hinfo,
1189                        struct dx_map_entry *map_tail)
1190 {
1191         int count = 0;
1192         char *base = (char *) de;
1193         struct dx_hash_info h = *hinfo;
1194
1195         while ((char *) de < base + blocksize) {
1196                 if (de->name_len && de->inode) {
1197                         ext4fs_dirhash(de->name, de->name_len, &h);
1198                         map_tail--;
1199                         map_tail->hash = h.hash;
1200                         map_tail->offs = ((char *) de - base)>>2;
1201                         map_tail->size = le16_to_cpu(de->rec_len);
1202                         count++;
1203                         cond_resched();
1204                 }
1205                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1206                 de = ext4_next_entry(de, blocksize);
1207         }
1208         return count;
1209 }
1210
1211 /* Sort map by hash value */
1212 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1213 {
1214         struct dx_map_entry *p, *q, *top = map + count - 1;
1215         int more;
1216         /* Combsort until bubble sort doesn't suck */
1217         while (count > 2) {
1218                 count = count*10/13;
1219                 if (count - 9 < 2) /* 9, 10 -> 11 */
1220                         count = 11;
1221                 for (p = top, q = p - count; q >= map; p--, q--)
1222                         if (p->hash < q->hash)
1223                                 swap(*p, *q);
1224         }
1225         /* Garden variety bubble sort */
1226         do {
1227                 more = 0;
1228                 q = top;
1229                 while (q-- > map) {
1230                         if (q[1].hash >= q[0].hash)
1231                                 continue;
1232                         swap(*(q+1), *q);
1233                         more = 1;
1234                 }
1235         } while(more);
1236 }
1237
1238 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1239 {
1240         struct dx_entry *entries = frame->entries;
1241         struct dx_entry *old = frame->at, *new = old + 1;
1242         int count = dx_get_count(entries);
1243
1244         assert(count < dx_get_limit(entries));
1245         assert(old < entries + count);
1246         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1247         dx_set_hash(new, hash);
1248         dx_set_block(new, block);
1249         dx_set_count(entries, count + 1);
1250 }
1251
1252 /*
1253  * Test whether a directory entry matches the filename being searched for.
1254  *
1255  * Return: %true if the directory entry matches, otherwise %false.
1256  */
1257 static inline bool ext4_match(const struct ext4_filename *fname,
1258                               const struct ext4_dir_entry_2 *de)
1259 {
1260         struct fscrypt_name f;
1261
1262         if (!de->inode)
1263                 return false;
1264
1265         f.usr_fname = fname->usr_fname;
1266         f.disk_name = fname->disk_name;
1267 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1268         f.crypto_buf = fname->crypto_buf;
1269 #endif
1270         return fscrypt_match_name(&f, de->name, de->name_len);
1271 }
1272
1273 /*
1274  * Returns 0 if not found, -1 on failure, and 1 on success
1275  */
1276 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1277                     struct inode *dir, struct ext4_filename *fname,
1278                     unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1279 {
1280         struct ext4_dir_entry_2 * de;
1281         char * dlimit;
1282         int de_len;
1283
1284         de = (struct ext4_dir_entry_2 *)search_buf;
1285         dlimit = search_buf + buf_size;
1286         while ((char *) de < dlimit) {
1287                 /* this code is executed quadratically often */
1288                 /* do minimal checking `by hand' */
1289                 if ((char *) de + de->name_len <= dlimit &&
1290                     ext4_match(fname, de)) {
1291                         /* found a match - just to be sure, do
1292                          * a full check */
1293                         if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1294                                                  bh->b_size, offset))
1295                                 return -1;
1296                         *res_dir = de;
1297                         return 1;
1298                 }
1299                 /* prevent looping on a bad block */
1300                 de_len = ext4_rec_len_from_disk(de->rec_len,
1301                                                 dir->i_sb->s_blocksize);
1302                 if (de_len <= 0)
1303                         return -1;
1304                 offset += de_len;
1305                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1306         }
1307         return 0;
1308 }
1309
1310 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1311                                struct ext4_dir_entry *de)
1312 {
1313         struct super_block *sb = dir->i_sb;
1314
1315         if (!is_dx(dir))
1316                 return 0;
1317         if (block == 0)
1318                 return 1;
1319         if (de->inode == 0 &&
1320             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1321                         sb->s_blocksize)
1322                 return 1;
1323         return 0;
1324 }
1325
1326 /*
1327  *      ext4_find_entry()
1328  *
1329  * finds an entry in the specified directory with the wanted name. It
1330  * returns the cache buffer in which the entry was found, and the entry
1331  * itself (as a parameter - res_dir). It does NOT read the inode of the
1332  * entry - you'll have to do that yourself if you want to.
1333  *
1334  * The returned buffer_head has ->b_count elevated.  The caller is expected
1335  * to brelse() it when appropriate.
1336  */
1337 static struct buffer_head * ext4_find_entry (struct inode *dir,
1338                                         const struct qstr *d_name,
1339                                         struct ext4_dir_entry_2 **res_dir,
1340                                         int *inlined)
1341 {
1342         struct super_block *sb;
1343         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1344         struct buffer_head *bh, *ret = NULL;
1345         ext4_lblk_t start, block, b;
1346         const u8 *name = d_name->name;
1347         int ra_max = 0;         /* Number of bh's in the readahead
1348                                    buffer, bh_use[] */
1349         int ra_ptr = 0;         /* Current index into readahead
1350                                    buffer */
1351         int num = 0;
1352         ext4_lblk_t  nblocks;
1353         int i, namelen, retval;
1354         struct ext4_filename fname;
1355
1356         *res_dir = NULL;
1357         sb = dir->i_sb;
1358         namelen = d_name->len;
1359         if (namelen > EXT4_NAME_LEN)
1360                 return NULL;
1361
1362         retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1363         if (retval == -ENOENT)
1364                 return NULL;
1365         if (retval)
1366                 return ERR_PTR(retval);
1367
1368         if (ext4_has_inline_data(dir)) {
1369                 int has_inline_data = 1;
1370                 ret = ext4_find_inline_entry(dir, &fname, res_dir,
1371                                              &has_inline_data);
1372                 if (has_inline_data) {
1373                         if (inlined)
1374                                 *inlined = 1;
1375                         goto cleanup_and_exit;
1376                 }
1377         }
1378
1379         if ((namelen <= 2) && (name[0] == '.') &&
1380             (name[1] == '.' || name[1] == '\0')) {
1381                 /*
1382                  * "." or ".." will only be in the first block
1383                  * NFS may look up ".."; "." should be handled by the VFS
1384                  */
1385                 block = start = 0;
1386                 nblocks = 1;
1387                 goto restart;
1388         }
1389         if (is_dx(dir)) {
1390                 ret = ext4_dx_find_entry(dir, &fname, res_dir);
1391                 /*
1392                  * On success, or if the error was file not found,
1393                  * return.  Otherwise, fall back to doing a search the
1394                  * old fashioned way.
1395                  */
1396                 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1397                         goto cleanup_and_exit;
1398                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1399                                "falling back\n"));
1400         }
1401         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1402         start = EXT4_I(dir)->i_dir_start_lookup;
1403         if (start >= nblocks)
1404                 start = 0;
1405         block = start;
1406 restart:
1407         do {
1408                 /*
1409                  * We deal with the read-ahead logic here.
1410                  */
1411                 if (ra_ptr >= ra_max) {
1412                         /* Refill the readahead buffer */
1413                         ra_ptr = 0;
1414                         b = block;
1415                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1416                                 /*
1417                                  * Terminate if we reach the end of the
1418                                  * directory and must wrap, or if our
1419                                  * search has finished at this block.
1420                                  */
1421                                 if (b >= nblocks || (num && block == start)) {
1422                                         bh_use[ra_max] = NULL;
1423                                         break;
1424                                 }
1425                                 num++;
1426                                 bh = ext4_getblk(NULL, dir, b++, 0);
1427                                 if (IS_ERR(bh)) {
1428                                         if (ra_max == 0) {
1429                                                 ret = bh;
1430                                                 goto cleanup_and_exit;
1431                                         }
1432                                         break;
1433                                 }
1434                                 bh_use[ra_max] = bh;
1435                                 if (bh)
1436                                         ll_rw_block(REQ_OP_READ,
1437                                                     REQ_META | REQ_PRIO,
1438                                                     1, &bh);
1439                         }
1440                 }
1441                 if ((bh = bh_use[ra_ptr++]) == NULL)
1442                         goto next;
1443                 wait_on_buffer(bh);
1444                 if (!buffer_uptodate(bh)) {
1445                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1446                                          (unsigned long) block);
1447                         brelse(bh);
1448                         ret = ERR_PTR(-EIO);
1449                         goto cleanup_and_exit;
1450                 }
1451                 if (!buffer_verified(bh) &&
1452                     !is_dx_internal_node(dir, block,
1453                                          (struct ext4_dir_entry *)bh->b_data) &&
1454                     !ext4_dirent_csum_verify(dir,
1455                                 (struct ext4_dir_entry *)bh->b_data)) {
1456                         EXT4_ERROR_INODE(dir, "checksumming directory "
1457                                          "block %lu", (unsigned long)block);
1458                         brelse(bh);
1459                         ret = ERR_PTR(-EFSBADCRC);
1460                         goto cleanup_and_exit;
1461                 }
1462                 set_buffer_verified(bh);
1463                 i = search_dirblock(bh, dir, &fname,
1464                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1465                 if (i == 1) {
1466                         EXT4_I(dir)->i_dir_start_lookup = block;
1467                         ret = bh;
1468                         goto cleanup_and_exit;
1469                 } else {
1470                         brelse(bh);
1471                         if (i < 0)
1472                                 goto cleanup_and_exit;
1473                 }
1474         next:
1475                 if (++block >= nblocks)
1476                         block = 0;
1477         } while (block != start);
1478
1479         /*
1480          * If the directory has grown while we were searching, then
1481          * search the last part of the directory before giving up.
1482          */
1483         block = nblocks;
1484         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1485         if (block < nblocks) {
1486                 start = 0;
1487                 goto restart;
1488         }
1489
1490 cleanup_and_exit:
1491         /* Clean up the read-ahead blocks */
1492         for (; ra_ptr < ra_max; ra_ptr++)
1493                 brelse(bh_use[ra_ptr]);
1494         ext4_fname_free_filename(&fname);
1495         return ret;
1496 }
1497
1498 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1499                         struct ext4_filename *fname,
1500                         struct ext4_dir_entry_2 **res_dir)
1501 {
1502         struct super_block * sb = dir->i_sb;
1503         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1504         struct buffer_head *bh;
1505         ext4_lblk_t block;
1506         int retval;
1507
1508 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1509         *res_dir = NULL;
1510 #endif
1511         frame = dx_probe(fname, dir, NULL, frames);
1512         if (IS_ERR(frame))
1513                 return (struct buffer_head *) frame;
1514         do {
1515                 block = dx_get_block(frame->at);
1516                 bh = ext4_read_dirblock(dir, block, DIRENT);
1517                 if (IS_ERR(bh))
1518                         goto errout;
1519
1520                 retval = search_dirblock(bh, dir, fname,
1521                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1522                                          res_dir);
1523                 if (retval == 1)
1524                         goto success;
1525                 brelse(bh);
1526                 if (retval == -1) {
1527                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1528                         goto errout;
1529                 }
1530
1531                 /* Check to see if we should continue to search */
1532                 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1533                                                frames, NULL);
1534                 if (retval < 0) {
1535                         ext4_warning_inode(dir,
1536                                 "error %d reading directory index block",
1537                                 retval);
1538                         bh = ERR_PTR(retval);
1539                         goto errout;
1540                 }
1541         } while (retval == 1);
1542
1543         bh = NULL;
1544 errout:
1545         dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1546 success:
1547         dx_release(frames);
1548         return bh;
1549 }
1550
1551 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1552 {
1553         struct inode *inode;
1554         struct ext4_dir_entry_2 *de;
1555         struct buffer_head *bh;
1556
1557         if (ext4_encrypted_inode(dir)) {
1558                 int res = fscrypt_get_encryption_info(dir);
1559
1560                 /*
1561                  * DCACHE_ENCRYPTED_WITH_KEY is set if the dentry is
1562                  * created while the directory was encrypted and we
1563                  * have access to the key.
1564                  */
1565                 if (fscrypt_has_encryption_key(dir))
1566                         fscrypt_set_encrypted_dentry(dentry);
1567                 fscrypt_set_d_op(dentry);
1568                 if (res && res != -ENOKEY)
1569                         return ERR_PTR(res);
1570         }
1571
1572        if (dentry->d_name.len > EXT4_NAME_LEN)
1573                return ERR_PTR(-ENAMETOOLONG);
1574
1575         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1576         if (IS_ERR(bh))
1577                 return (struct dentry *) bh;
1578         inode = NULL;
1579         if (bh) {
1580                 __u32 ino = le32_to_cpu(de->inode);
1581                 brelse(bh);
1582                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1583                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1584                         return ERR_PTR(-EFSCORRUPTED);
1585                 }
1586                 if (unlikely(ino == dir->i_ino)) {
1587                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1588                                          dentry);
1589                         return ERR_PTR(-EFSCORRUPTED);
1590                 }
1591                 inode = ext4_iget_normal(dir->i_sb, ino);
1592                 if (inode == ERR_PTR(-ESTALE)) {
1593                         EXT4_ERROR_INODE(dir,
1594                                          "deleted inode referenced: %u",
1595                                          ino);
1596                         return ERR_PTR(-EFSCORRUPTED);
1597                 }
1598                 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1599                     (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1600                     !fscrypt_has_permitted_context(dir, inode)) {
1601                         ext4_warning(inode->i_sb,
1602                                      "Inconsistent encryption contexts: %lu/%lu",
1603                                      dir->i_ino, inode->i_ino);
1604                         iput(inode);
1605                         return ERR_PTR(-EPERM);
1606                 }
1607         }
1608         return d_splice_alias(inode, dentry);
1609 }
1610
1611
1612 struct dentry *ext4_get_parent(struct dentry *child)
1613 {
1614         __u32 ino;
1615         static const struct qstr dotdot = QSTR_INIT("..", 2);
1616         struct ext4_dir_entry_2 * de;
1617         struct buffer_head *bh;
1618
1619         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1620         if (IS_ERR(bh))
1621                 return (struct dentry *) bh;
1622         if (!bh)
1623                 return ERR_PTR(-ENOENT);
1624         ino = le32_to_cpu(de->inode);
1625         brelse(bh);
1626
1627         if (!ext4_valid_inum(child->d_sb, ino)) {
1628                 EXT4_ERROR_INODE(d_inode(child),
1629                                  "bad parent inode number: %u", ino);
1630                 return ERR_PTR(-EFSCORRUPTED);
1631         }
1632
1633         return d_obtain_alias(ext4_iget_normal(child->d_sb, ino));
1634 }
1635
1636 /*
1637  * Move count entries from end of map between two memory locations.
1638  * Returns pointer to last entry moved.
1639  */
1640 static struct ext4_dir_entry_2 *
1641 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1642                 unsigned blocksize)
1643 {
1644         unsigned rec_len = 0;
1645
1646         while (count--) {
1647                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1648                                                 (from + (map->offs<<2));
1649                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1650                 memcpy (to, de, rec_len);
1651                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1652                                 ext4_rec_len_to_disk(rec_len, blocksize);
1653                 de->inode = 0;
1654                 map++;
1655                 to += rec_len;
1656         }
1657         return (struct ext4_dir_entry_2 *) (to - rec_len);
1658 }
1659
1660 /*
1661  * Compact each dir entry in the range to the minimal rec_len.
1662  * Returns pointer to last entry in range.
1663  */
1664 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1665 {
1666         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1667         unsigned rec_len = 0;
1668
1669         prev = to = de;
1670         while ((char*)de < base + blocksize) {
1671                 next = ext4_next_entry(de, blocksize);
1672                 if (de->inode && de->name_len) {
1673                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1674                         if (de > to)
1675                                 memmove(to, de, rec_len);
1676                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1677                         prev = to;
1678                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1679                 }
1680                 de = next;
1681         }
1682         return prev;
1683 }
1684
1685 /*
1686  * Split a full leaf block to make room for a new dir entry.
1687  * Allocate a new block, and move entries so that they are approx. equally full.
1688  * Returns pointer to de in block into which the new entry will be inserted.
1689  */
1690 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1691                         struct buffer_head **bh,struct dx_frame *frame,
1692                         struct dx_hash_info *hinfo)
1693 {
1694         unsigned blocksize = dir->i_sb->s_blocksize;
1695         unsigned count, continued;
1696         struct buffer_head *bh2;
1697         ext4_lblk_t newblock;
1698         u32 hash2;
1699         struct dx_map_entry *map;
1700         char *data1 = (*bh)->b_data, *data2;
1701         unsigned split, move, size;
1702         struct ext4_dir_entry_2 *de = NULL, *de2;
1703         struct ext4_dir_entry_tail *t;
1704         int     csum_size = 0;
1705         int     err = 0, i;
1706
1707         if (ext4_has_metadata_csum(dir->i_sb))
1708                 csum_size = sizeof(struct ext4_dir_entry_tail);
1709
1710         bh2 = ext4_append(handle, dir, &newblock);
1711         if (IS_ERR(bh2)) {
1712                 brelse(*bh);
1713                 *bh = NULL;
1714                 return (struct ext4_dir_entry_2 *) bh2;
1715         }
1716
1717         BUFFER_TRACE(*bh, "get_write_access");
1718         err = ext4_journal_get_write_access(handle, *bh);
1719         if (err)
1720                 goto journal_error;
1721
1722         BUFFER_TRACE(frame->bh, "get_write_access");
1723         err = ext4_journal_get_write_access(handle, frame->bh);
1724         if (err)
1725                 goto journal_error;
1726
1727         data2 = bh2->b_data;
1728
1729         /* create map in the end of data2 block */
1730         map = (struct dx_map_entry *) (data2 + blocksize);
1731         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1732                              blocksize, hinfo, map);
1733         map -= count;
1734         dx_sort_map(map, count);
1735         /* Split the existing block in the middle, size-wise */
1736         size = 0;
1737         move = 0;
1738         for (i = count-1; i >= 0; i--) {
1739                 /* is more than half of this entry in 2nd half of the block? */
1740                 if (size + map[i].size/2 > blocksize/2)
1741                         break;
1742                 size += map[i].size;
1743                 move++;
1744         }
1745         /* map index at which we will split */
1746         split = count - move;
1747         hash2 = map[split].hash;
1748         continued = hash2 == map[split - 1].hash;
1749         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1750                         (unsigned long)dx_get_block(frame->at),
1751                                         hash2, split, count-split));
1752
1753         /* Fancy dance to stay within two buffers */
1754         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1755                               blocksize);
1756         de = dx_pack_dirents(data1, blocksize);
1757         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1758                                            (char *) de,
1759                                            blocksize);
1760         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1761                                             (char *) de2,
1762                                             blocksize);
1763         if (csum_size) {
1764                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1765                 initialize_dirent_tail(t, blocksize);
1766
1767                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1768                 initialize_dirent_tail(t, blocksize);
1769         }
1770
1771         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1772                         blocksize, 1));
1773         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1774                         blocksize, 1));
1775
1776         /* Which block gets the new entry? */
1777         if (hinfo->hash >= hash2) {
1778                 swap(*bh, bh2);
1779                 de = de2;
1780         }
1781         dx_insert_block(frame, hash2 + continued, newblock);
1782         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1783         if (err)
1784                 goto journal_error;
1785         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1786         if (err)
1787                 goto journal_error;
1788         brelse(bh2);
1789         dxtrace(dx_show_index("frame", frame->entries));
1790         return de;
1791
1792 journal_error:
1793         brelse(*bh);
1794         brelse(bh2);
1795         *bh = NULL;
1796         ext4_std_error(dir->i_sb, err);
1797         return ERR_PTR(err);
1798 }
1799
1800 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1801                       struct buffer_head *bh,
1802                       void *buf, int buf_size,
1803                       struct ext4_filename *fname,
1804                       struct ext4_dir_entry_2 **dest_de)
1805 {
1806         struct ext4_dir_entry_2 *de;
1807         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1808         int nlen, rlen;
1809         unsigned int offset = 0;
1810         char *top;
1811
1812         de = (struct ext4_dir_entry_2 *)buf;
1813         top = buf + buf_size - reclen;
1814         while ((char *) de <= top) {
1815                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1816                                          buf, buf_size, offset))
1817                         return -EFSCORRUPTED;
1818                 if (ext4_match(fname, de))
1819                         return -EEXIST;
1820                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1821                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1822                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1823                         break;
1824                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1825                 offset += rlen;
1826         }
1827         if ((char *) de > top)
1828                 return -ENOSPC;
1829
1830         *dest_de = de;
1831         return 0;
1832 }
1833
1834 void ext4_insert_dentry(struct inode *inode,
1835                         struct ext4_dir_entry_2 *de,
1836                         int buf_size,
1837                         struct ext4_filename *fname)
1838 {
1839
1840         int nlen, rlen;
1841
1842         nlen = EXT4_DIR_REC_LEN(de->name_len);
1843         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1844         if (de->inode) {
1845                 struct ext4_dir_entry_2 *de1 =
1846                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1847                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1848                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1849                 de = de1;
1850         }
1851         de->file_type = EXT4_FT_UNKNOWN;
1852         de->inode = cpu_to_le32(inode->i_ino);
1853         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1854         de->name_len = fname_len(fname);
1855         memcpy(de->name, fname_name(fname), fname_len(fname));
1856 }
1857
1858 /*
1859  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1860  * it points to a directory entry which is guaranteed to be large
1861  * enough for new directory entry.  If de is NULL, then
1862  * add_dirent_to_buf will attempt search the directory block for
1863  * space.  It will return -ENOSPC if no space is available, and -EIO
1864  * and -EEXIST if directory entry already exists.
1865  */
1866 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1867                              struct inode *dir,
1868                              struct inode *inode, struct ext4_dir_entry_2 *de,
1869                              struct buffer_head *bh)
1870 {
1871         unsigned int    blocksize = dir->i_sb->s_blocksize;
1872         int             csum_size = 0;
1873         int             err;
1874
1875         if (ext4_has_metadata_csum(inode->i_sb))
1876                 csum_size = sizeof(struct ext4_dir_entry_tail);
1877
1878         if (!de) {
1879                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1880                                         blocksize - csum_size, fname, &de);
1881                 if (err)
1882                         return err;
1883         }
1884         BUFFER_TRACE(bh, "get_write_access");
1885         err = ext4_journal_get_write_access(handle, bh);
1886         if (err) {
1887                 ext4_std_error(dir->i_sb, err);
1888                 return err;
1889         }
1890
1891         /* By now the buffer is marked for journaling */
1892         ext4_insert_dentry(inode, de, blocksize, fname);
1893
1894         /*
1895          * XXX shouldn't update any times until successful
1896          * completion of syscall, but too many callers depend
1897          * on this.
1898          *
1899          * XXX similarly, too many callers depend on
1900          * ext4_new_inode() setting the times, but error
1901          * recovery deletes the inode, so the worst that can
1902          * happen is that the times are slightly out of date
1903          * and/or different from the directory change time.
1904          */
1905         dir->i_mtime = dir->i_ctime = current_time(dir);
1906         ext4_update_dx_flag(dir);
1907         inode_inc_iversion(dir);
1908         ext4_mark_inode_dirty(handle, dir);
1909         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1910         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1911         if (err)
1912                 ext4_std_error(dir->i_sb, err);
1913         return 0;
1914 }
1915
1916 /*
1917  * This converts a one block unindexed directory to a 3 block indexed
1918  * directory, and adds the dentry to the indexed directory.
1919  */
1920 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1921                             struct inode *dir,
1922                             struct inode *inode, struct buffer_head *bh)
1923 {
1924         struct buffer_head *bh2;
1925         struct dx_root  *root;
1926         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1927         struct dx_entry *entries;
1928         struct ext4_dir_entry_2 *de, *de2;
1929         struct ext4_dir_entry_tail *t;
1930         char            *data1, *top;
1931         unsigned        len;
1932         int             retval;
1933         unsigned        blocksize;
1934         ext4_lblk_t  block;
1935         struct fake_dirent *fde;
1936         int csum_size = 0;
1937
1938         if (ext4_has_metadata_csum(inode->i_sb))
1939                 csum_size = sizeof(struct ext4_dir_entry_tail);
1940
1941         blocksize =  dir->i_sb->s_blocksize;
1942         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1943         BUFFER_TRACE(bh, "get_write_access");
1944         retval = ext4_journal_get_write_access(handle, bh);
1945         if (retval) {
1946                 ext4_std_error(dir->i_sb, retval);
1947                 brelse(bh);
1948                 return retval;
1949         }
1950         root = (struct dx_root *) bh->b_data;
1951
1952         /* The 0th block becomes the root, move the dirents out */
1953         fde = &root->dotdot;
1954         de = (struct ext4_dir_entry_2 *)((char *)fde +
1955                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1956         if ((char *) de >= (((char *) root) + blocksize)) {
1957                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1958                 brelse(bh);
1959                 return -EFSCORRUPTED;
1960         }
1961         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1962
1963         /* Allocate new block for the 0th block's dirents */
1964         bh2 = ext4_append(handle, dir, &block);
1965         if (IS_ERR(bh2)) {
1966                 brelse(bh);
1967                 return PTR_ERR(bh2);
1968         }
1969         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1970         data1 = bh2->b_data;
1971
1972         memcpy (data1, de, len);
1973         de = (struct ext4_dir_entry_2 *) data1;
1974         top = data1 + len;
1975         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1976                 de = de2;
1977         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1978                                            (char *) de,
1979                                            blocksize);
1980
1981         if (csum_size) {
1982                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1983                 initialize_dirent_tail(t, blocksize);
1984         }
1985
1986         /* Initialize the root; the dot dirents already exist */
1987         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1988         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1989                                            blocksize);
1990         memset (&root->info, 0, sizeof(root->info));
1991         root->info.info_length = sizeof(root->info);
1992         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1993         entries = root->entries;
1994         dx_set_block(entries, 1);
1995         dx_set_count(entries, 1);
1996         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1997
1998         /* Initialize as for dx_probe */
1999         fname->hinfo.hash_version = root->info.hash_version;
2000         if (fname->hinfo.hash_version <= DX_HASH_TEA)
2001                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2002         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2003         ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
2004
2005         memset(frames, 0, sizeof(frames));
2006         frame = frames;
2007         frame->entries = entries;
2008         frame->at = entries;
2009         frame->bh = bh;
2010
2011         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2012         if (retval)
2013                 goto out_frames;
2014         retval = ext4_handle_dirty_dirent_node(handle, dir, bh2);
2015         if (retval)
2016                 goto out_frames;
2017
2018         de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2019         if (IS_ERR(de)) {
2020                 retval = PTR_ERR(de);
2021                 goto out_frames;
2022         }
2023
2024         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2025 out_frames:
2026         /*
2027          * Even if the block split failed, we have to properly write
2028          * out all the changes we did so far. Otherwise we can end up
2029          * with corrupted filesystem.
2030          */
2031         if (retval)
2032                 ext4_mark_inode_dirty(handle, dir);
2033         dx_release(frames);
2034         brelse(bh2);
2035         return retval;
2036 }
2037
2038 /*
2039  *      ext4_add_entry()
2040  *
2041  * adds a file entry to the specified directory, using the same
2042  * semantics as ext4_find_entry(). It returns NULL if it failed.
2043  *
2044  * NOTE!! The inode part of 'de' is left at 0 - which means you
2045  * may not sleep between calling this and putting something into
2046  * the entry, as someone else might have used it while you slept.
2047  */
2048 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2049                           struct inode *inode)
2050 {
2051         struct inode *dir = d_inode(dentry->d_parent);
2052         struct buffer_head *bh = NULL;
2053         struct ext4_dir_entry_2 *de;
2054         struct ext4_dir_entry_tail *t;
2055         struct super_block *sb;
2056         struct ext4_filename fname;
2057         int     retval;
2058         int     dx_fallback=0;
2059         unsigned blocksize;
2060         ext4_lblk_t block, blocks;
2061         int     csum_size = 0;
2062
2063         if (ext4_has_metadata_csum(inode->i_sb))
2064                 csum_size = sizeof(struct ext4_dir_entry_tail);
2065
2066         sb = dir->i_sb;
2067         blocksize = sb->s_blocksize;
2068         if (!dentry->d_name.len)
2069                 return -EINVAL;
2070
2071         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2072         if (retval)
2073                 return retval;
2074
2075         if (ext4_has_inline_data(dir)) {
2076                 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2077                 if (retval < 0)
2078                         goto out;
2079                 if (retval == 1) {
2080                         retval = 0;
2081                         goto out;
2082                 }
2083         }
2084
2085         if (is_dx(dir)) {
2086                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2087                 if (!retval || (retval != ERR_BAD_DX_DIR))
2088                         goto out;
2089                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2090                 dx_fallback++;
2091                 ext4_mark_inode_dirty(handle, dir);
2092         }
2093         blocks = dir->i_size >> sb->s_blocksize_bits;
2094         for (block = 0; block < blocks; block++) {
2095                 bh = ext4_read_dirblock(dir, block, DIRENT);
2096                 if (IS_ERR(bh)) {
2097                         retval = PTR_ERR(bh);
2098                         bh = NULL;
2099                         goto out;
2100                 }
2101                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2102                                            NULL, bh);
2103                 if (retval != -ENOSPC)
2104                         goto out;
2105
2106                 if (blocks == 1 && !dx_fallback &&
2107                     ext4_has_feature_dir_index(sb)) {
2108                         retval = make_indexed_dir(handle, &fname, dir,
2109                                                   inode, bh);
2110                         bh = NULL; /* make_indexed_dir releases bh */
2111                         goto out;
2112                 }
2113                 brelse(bh);
2114         }
2115         bh = ext4_append(handle, dir, &block);
2116         if (IS_ERR(bh)) {
2117                 retval = PTR_ERR(bh);
2118                 bh = NULL;
2119                 goto out;
2120         }
2121         de = (struct ext4_dir_entry_2 *) bh->b_data;
2122         de->inode = 0;
2123         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2124
2125         if (csum_size) {
2126                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2127                 initialize_dirent_tail(t, blocksize);
2128         }
2129
2130         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2131 out:
2132         ext4_fname_free_filename(&fname);
2133         brelse(bh);
2134         if (retval == 0)
2135                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2136         return retval;
2137 }
2138
2139 /*
2140  * Returns 0 for success, or a negative error value
2141  */
2142 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2143                              struct inode *dir, struct inode *inode)
2144 {
2145         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2146         struct dx_entry *entries, *at;
2147         struct buffer_head *bh;
2148         struct super_block *sb = dir->i_sb;
2149         struct ext4_dir_entry_2 *de;
2150         int restart;
2151         int err;
2152
2153 again:
2154         restart = 0;
2155         frame = dx_probe(fname, dir, NULL, frames);
2156         if (IS_ERR(frame))
2157                 return PTR_ERR(frame);
2158         entries = frame->entries;
2159         at = frame->at;
2160         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2161         if (IS_ERR(bh)) {
2162                 err = PTR_ERR(bh);
2163                 bh = NULL;
2164                 goto cleanup;
2165         }
2166
2167         BUFFER_TRACE(bh, "get_write_access");
2168         err = ext4_journal_get_write_access(handle, bh);
2169         if (err)
2170                 goto journal_error;
2171
2172         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2173         if (err != -ENOSPC)
2174                 goto cleanup;
2175
2176         err = 0;
2177         /* Block full, should compress but for now just split */
2178         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2179                        dx_get_count(entries), dx_get_limit(entries)));
2180         /* Need to split index? */
2181         if (dx_get_count(entries) == dx_get_limit(entries)) {
2182                 ext4_lblk_t newblock;
2183                 int levels = frame - frames + 1;
2184                 unsigned int icount;
2185                 int add_level = 1;
2186                 struct dx_entry *entries2;
2187                 struct dx_node *node2;
2188                 struct buffer_head *bh2;
2189
2190                 while (frame > frames) {
2191                         if (dx_get_count((frame - 1)->entries) <
2192                             dx_get_limit((frame - 1)->entries)) {
2193                                 add_level = 0;
2194                                 break;
2195                         }
2196                         frame--; /* split higher index block */
2197                         at = frame->at;
2198                         entries = frame->entries;
2199                         restart = 1;
2200                 }
2201                 if (add_level && levels == ext4_dir_htree_level(sb)) {
2202                         ext4_warning(sb, "Directory (ino: %lu) index full, "
2203                                          "reach max htree level :%d",
2204                                          dir->i_ino, levels);
2205                         if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2206                                 ext4_warning(sb, "Large directory feature is "
2207                                                  "not enabled on this "
2208                                                  "filesystem");
2209                         }
2210                         err = -ENOSPC;
2211                         goto cleanup;
2212                 }
2213                 icount = dx_get_count(entries);
2214                 bh2 = ext4_append(handle, dir, &newblock);
2215                 if (IS_ERR(bh2)) {
2216                         err = PTR_ERR(bh2);
2217                         goto cleanup;
2218                 }
2219                 node2 = (struct dx_node *)(bh2->b_data);
2220                 entries2 = node2->entries;
2221                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2222                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2223                                                            sb->s_blocksize);
2224                 BUFFER_TRACE(frame->bh, "get_write_access");
2225                 err = ext4_journal_get_write_access(handle, frame->bh);
2226                 if (err)
2227                         goto journal_error;
2228                 if (!add_level) {
2229                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2230                         unsigned hash2 = dx_get_hash(entries + icount1);
2231                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2232                                        icount1, icount2));
2233
2234                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2235                         err = ext4_journal_get_write_access(handle,
2236                                                              (frame - 1)->bh);
2237                         if (err)
2238                                 goto journal_error;
2239
2240                         memcpy((char *) entries2, (char *) (entries + icount1),
2241                                icount2 * sizeof(struct dx_entry));
2242                         dx_set_count(entries, icount1);
2243                         dx_set_count(entries2, icount2);
2244                         dx_set_limit(entries2, dx_node_limit(dir));
2245
2246                         /* Which index block gets the new entry? */
2247                         if (at - entries >= icount1) {
2248                                 frame->at = at = at - entries - icount1 + entries2;
2249                                 frame->entries = entries = entries2;
2250                                 swap(frame->bh, bh2);
2251                         }
2252                         dx_insert_block((frame - 1), hash2, newblock);
2253                         dxtrace(dx_show_index("node", frame->entries));
2254                         dxtrace(dx_show_index("node",
2255                                ((struct dx_node *) bh2->b_data)->entries));
2256                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2257                         if (err)
2258                                 goto journal_error;
2259                         brelse (bh2);
2260                         err = ext4_handle_dirty_dx_node(handle, dir,
2261                                                    (frame - 1)->bh);
2262                         if (err)
2263                                 goto journal_error;
2264                         if (restart) {
2265                                 err = ext4_handle_dirty_dx_node(handle, dir,
2266                                                            frame->bh);
2267                                 goto journal_error;
2268                         }
2269                 } else {
2270                         struct dx_root *dxroot;
2271                         memcpy((char *) entries2, (char *) entries,
2272                                icount * sizeof(struct dx_entry));
2273                         dx_set_limit(entries2, dx_node_limit(dir));
2274
2275                         /* Set up root */
2276                         dx_set_count(entries, 1);
2277                         dx_set_block(entries + 0, newblock);
2278                         dxroot = (struct dx_root *)frames[0].bh->b_data;
2279                         dxroot->info.indirect_levels += 1;
2280                         dxtrace(printk(KERN_DEBUG
2281                                        "Creating %d level index...\n",
2282                                        info->indirect_levels));
2283                         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2284                         if (err)
2285                                 goto journal_error;
2286                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2287                         brelse(bh2);
2288                         restart = 1;
2289                         goto journal_error;
2290                 }
2291         }
2292         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2293         if (IS_ERR(de)) {
2294                 err = PTR_ERR(de);
2295                 goto cleanup;
2296         }
2297         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2298         goto cleanup;
2299
2300 journal_error:
2301         ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2302 cleanup:
2303         brelse(bh);
2304         dx_release(frames);
2305         /* @restart is true means htree-path has been changed, we need to
2306          * repeat dx_probe() to find out valid htree-path
2307          */
2308         if (restart && err == 0)
2309                 goto again;
2310         return err;
2311 }
2312
2313 /*
2314  * ext4_generic_delete_entry deletes a directory entry by merging it
2315  * with the previous entry
2316  */
2317 int ext4_generic_delete_entry(handle_t *handle,
2318                               struct inode *dir,
2319                               struct ext4_dir_entry_2 *de_del,
2320                               struct buffer_head *bh,
2321                               void *entry_buf,
2322                               int buf_size,
2323                               int csum_size)
2324 {
2325         struct ext4_dir_entry_2 *de, *pde;
2326         unsigned int blocksize = dir->i_sb->s_blocksize;
2327         int i;
2328
2329         i = 0;
2330         pde = NULL;
2331         de = (struct ext4_dir_entry_2 *)entry_buf;
2332         while (i < buf_size - csum_size) {
2333                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2334                                          bh->b_data, bh->b_size, i))
2335                         return -EFSCORRUPTED;
2336                 if (de == de_del)  {
2337                         if (pde)
2338                                 pde->rec_len = ext4_rec_len_to_disk(
2339                                         ext4_rec_len_from_disk(pde->rec_len,
2340                                                                blocksize) +
2341                                         ext4_rec_len_from_disk(de->rec_len,
2342                                                                blocksize),
2343                                         blocksize);
2344                         else
2345                                 de->inode = 0;
2346                         inode_inc_iversion(dir);
2347                         return 0;
2348                 }
2349                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2350                 pde = de;
2351                 de = ext4_next_entry(de, blocksize);
2352         }
2353         return -ENOENT;
2354 }
2355
2356 static int ext4_delete_entry(handle_t *handle,
2357                              struct inode *dir,
2358                              struct ext4_dir_entry_2 *de_del,
2359                              struct buffer_head *bh)
2360 {
2361         int err, csum_size = 0;
2362
2363         if (ext4_has_inline_data(dir)) {
2364                 int has_inline_data = 1;
2365                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2366                                                &has_inline_data);
2367                 if (has_inline_data)
2368                         return err;
2369         }
2370
2371         if (ext4_has_metadata_csum(dir->i_sb))
2372                 csum_size = sizeof(struct ext4_dir_entry_tail);
2373
2374         BUFFER_TRACE(bh, "get_write_access");
2375         err = ext4_journal_get_write_access(handle, bh);
2376         if (unlikely(err))
2377                 goto out;
2378
2379         err = ext4_generic_delete_entry(handle, dir, de_del,
2380                                         bh, bh->b_data,
2381                                         dir->i_sb->s_blocksize, csum_size);
2382         if (err)
2383                 goto out;
2384
2385         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2386         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2387         if (unlikely(err))
2388                 goto out;
2389
2390         return 0;
2391 out:
2392         if (err != -ENOENT)
2393                 ext4_std_error(dir->i_sb, err);
2394         return err;
2395 }
2396
2397 /*
2398  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2399  * since this indicates that nlinks count was previously 1.
2400  */
2401 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2402 {
2403         inc_nlink(inode);
2404         if (is_dx(inode) && inode->i_nlink > 1) {
2405                 /* limit is 16-bit i_links_count */
2406                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2407                         set_nlink(inode, 1);
2408                         ext4_set_feature_dir_nlink(inode->i_sb);
2409                 }
2410         }
2411 }
2412
2413 /*
2414  * If a directory had nlink == 1, then we should let it be 1. This indicates
2415  * directory has >EXT4_LINK_MAX subdirs.
2416  */
2417 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2418 {
2419         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2420                 drop_nlink(inode);
2421 }
2422
2423
2424 static int ext4_add_nondir(handle_t *handle,
2425                 struct dentry *dentry, struct inode *inode)
2426 {
2427         int err = ext4_add_entry(handle, dentry, inode);
2428         if (!err) {
2429                 ext4_mark_inode_dirty(handle, inode);
2430                 unlock_new_inode(inode);
2431                 d_instantiate(dentry, inode);
2432                 return 0;
2433         }
2434         drop_nlink(inode);
2435         unlock_new_inode(inode);
2436         iput(inode);
2437         return err;
2438 }
2439
2440 /*
2441  * By the time this is called, we already have created
2442  * the directory cache entry for the new file, but it
2443  * is so far negative - it has no inode.
2444  *
2445  * If the create succeeds, we fill in the inode information
2446  * with d_instantiate().
2447  */
2448 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2449                        bool excl)
2450 {
2451         handle_t *handle;
2452         struct inode *inode;
2453         int err, credits, retries = 0;
2454
2455         err = dquot_initialize(dir);
2456         if (err)
2457                 return err;
2458
2459         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2460                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2461 retry:
2462         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2463                                             NULL, EXT4_HT_DIR, credits);
2464         handle = ext4_journal_current_handle();
2465         err = PTR_ERR(inode);
2466         if (!IS_ERR(inode)) {
2467                 inode->i_op = &ext4_file_inode_operations;
2468                 inode->i_fop = &ext4_file_operations;
2469                 ext4_set_aops(inode);
2470                 err = ext4_add_nondir(handle, dentry, inode);
2471                 if (!err && IS_DIRSYNC(dir))
2472                         ext4_handle_sync(handle);
2473         }
2474         if (handle)
2475                 ext4_journal_stop(handle);
2476         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2477                 goto retry;
2478         return err;
2479 }
2480
2481 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2482                       umode_t mode, dev_t rdev)
2483 {
2484         handle_t *handle;
2485         struct inode *inode;
2486         int err, credits, retries = 0;
2487
2488         err = dquot_initialize(dir);
2489         if (err)
2490                 return err;
2491
2492         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2493                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2494 retry:
2495         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2496                                             NULL, EXT4_HT_DIR, credits);
2497         handle = ext4_journal_current_handle();
2498         err = PTR_ERR(inode);
2499         if (!IS_ERR(inode)) {
2500                 init_special_inode(inode, inode->i_mode, rdev);
2501                 inode->i_op = &ext4_special_inode_operations;
2502                 err = ext4_add_nondir(handle, dentry, inode);
2503                 if (!err && IS_DIRSYNC(dir))
2504                         ext4_handle_sync(handle);
2505         }
2506         if (handle)
2507                 ext4_journal_stop(handle);
2508         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2509                 goto retry;
2510         return err;
2511 }
2512
2513 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2514 {
2515         handle_t *handle;
2516         struct inode *inode;
2517         int err, retries = 0;
2518
2519         err = dquot_initialize(dir);
2520         if (err)
2521                 return err;
2522
2523 retry:
2524         inode = ext4_new_inode_start_handle(dir, mode,
2525                                             NULL, 0, NULL,
2526                                             EXT4_HT_DIR,
2527                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2528                           4 + EXT4_XATTR_TRANS_BLOCKS);
2529         handle = ext4_journal_current_handle();
2530         err = PTR_ERR(inode);
2531         if (!IS_ERR(inode)) {
2532                 inode->i_op = &ext4_file_inode_operations;
2533                 inode->i_fop = &ext4_file_operations;
2534                 ext4_set_aops(inode);
2535                 d_tmpfile(dentry, inode);
2536                 err = ext4_orphan_add(handle, inode);
2537                 if (err)
2538                         goto err_unlock_inode;
2539                 mark_inode_dirty(inode);
2540                 unlock_new_inode(inode);
2541         }
2542         if (handle)
2543                 ext4_journal_stop(handle);
2544         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2545                 goto retry;
2546         return err;
2547 err_unlock_inode:
2548         ext4_journal_stop(handle);
2549         unlock_new_inode(inode);
2550         return err;
2551 }
2552
2553 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2554                           struct ext4_dir_entry_2 *de,
2555                           int blocksize, int csum_size,
2556                           unsigned int parent_ino, int dotdot_real_len)
2557 {
2558         de->inode = cpu_to_le32(inode->i_ino);
2559         de->name_len = 1;
2560         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2561                                            blocksize);
2562         strcpy(de->name, ".");
2563         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2564
2565         de = ext4_next_entry(de, blocksize);
2566         de->inode = cpu_to_le32(parent_ino);
2567         de->name_len = 2;
2568         if (!dotdot_real_len)
2569                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2570                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2571                                         blocksize);
2572         else
2573                 de->rec_len = ext4_rec_len_to_disk(
2574                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2575         strcpy(de->name, "..");
2576         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2577
2578         return ext4_next_entry(de, blocksize);
2579 }
2580
2581 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2582                              struct inode *inode)
2583 {
2584         struct buffer_head *dir_block = NULL;
2585         struct ext4_dir_entry_2 *de;
2586         struct ext4_dir_entry_tail *t;
2587         ext4_lblk_t block = 0;
2588         unsigned int blocksize = dir->i_sb->s_blocksize;
2589         int csum_size = 0;
2590         int err;
2591
2592         if (ext4_has_metadata_csum(dir->i_sb))
2593                 csum_size = sizeof(struct ext4_dir_entry_tail);
2594
2595         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2596                 err = ext4_try_create_inline_dir(handle, dir, inode);
2597                 if (err < 0 && err != -ENOSPC)
2598                         goto out;
2599                 if (!err)
2600                         goto out;
2601         }
2602
2603         inode->i_size = 0;
2604         dir_block = ext4_append(handle, inode, &block);
2605         if (IS_ERR(dir_block))
2606                 return PTR_ERR(dir_block);
2607         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2608         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2609         set_nlink(inode, 2);
2610         if (csum_size) {
2611                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2612                 initialize_dirent_tail(t, blocksize);
2613         }
2614
2615         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2616         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2617         if (err)
2618                 goto out;
2619         set_buffer_verified(dir_block);
2620 out:
2621         brelse(dir_block);
2622         return err;
2623 }
2624
2625 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2626 {
2627         handle_t *handle;
2628         struct inode *inode;
2629         int err, credits, retries = 0;
2630
2631         if (EXT4_DIR_LINK_MAX(dir))
2632                 return -EMLINK;
2633
2634         err = dquot_initialize(dir);
2635         if (err)
2636                 return err;
2637
2638         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2639                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2640 retry:
2641         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2642                                             &dentry->d_name,
2643                                             0, NULL, EXT4_HT_DIR, credits);
2644         handle = ext4_journal_current_handle();
2645         err = PTR_ERR(inode);
2646         if (IS_ERR(inode))
2647                 goto out_stop;
2648
2649         inode->i_op = &ext4_dir_inode_operations;
2650         inode->i_fop = &ext4_dir_operations;
2651         err = ext4_init_new_dir(handle, dir, inode);
2652         if (err)
2653                 goto out_clear_inode;
2654         err = ext4_mark_inode_dirty(handle, inode);
2655         if (!err)
2656                 err = ext4_add_entry(handle, dentry, inode);
2657         if (err) {
2658 out_clear_inode:
2659                 clear_nlink(inode);
2660                 unlock_new_inode(inode);
2661                 ext4_mark_inode_dirty(handle, inode);
2662                 iput(inode);
2663                 goto out_stop;
2664         }
2665         ext4_inc_count(handle, dir);
2666         ext4_update_dx_flag(dir);
2667         err = ext4_mark_inode_dirty(handle, dir);
2668         if (err)
2669                 goto out_clear_inode;
2670         unlock_new_inode(inode);
2671         d_instantiate(dentry, inode);
2672         if (IS_DIRSYNC(dir))
2673                 ext4_handle_sync(handle);
2674
2675 out_stop:
2676         if (handle)
2677                 ext4_journal_stop(handle);
2678         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2679                 goto retry;
2680         return err;
2681 }
2682
2683 /*
2684  * routine to check that the specified directory is empty (for rmdir)
2685  */
2686 bool ext4_empty_dir(struct inode *inode)
2687 {
2688         unsigned int offset;
2689         struct buffer_head *bh;
2690         struct ext4_dir_entry_2 *de, *de1;
2691         struct super_block *sb;
2692
2693         if (ext4_has_inline_data(inode)) {
2694                 int has_inline_data = 1;
2695                 int ret;
2696
2697                 ret = empty_inline_dir(inode, &has_inline_data);
2698                 if (has_inline_data)
2699                         return ret;
2700         }
2701
2702         sb = inode->i_sb;
2703         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2704                 EXT4_ERROR_INODE(inode, "invalid size");
2705                 return true;
2706         }
2707         bh = ext4_read_dirblock(inode, 0, EITHER);
2708         if (IS_ERR(bh))
2709                 return true;
2710
2711         de = (struct ext4_dir_entry_2 *) bh->b_data;
2712         de1 = ext4_next_entry(de, sb->s_blocksize);
2713         if (le32_to_cpu(de->inode) != inode->i_ino ||
2714                         le32_to_cpu(de1->inode) == 0 ||
2715                         strcmp(".", de->name) || strcmp("..", de1->name)) {
2716                 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2717                 brelse(bh);
2718                 return true;
2719         }
2720         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2721                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2722         de = ext4_next_entry(de1, sb->s_blocksize);
2723         while (offset < inode->i_size) {
2724                 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2725                         unsigned int lblock;
2726                         brelse(bh);
2727                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2728                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2729                         if (IS_ERR(bh))
2730                                 return true;
2731                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2732                 }
2733                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2734                                          bh->b_data, bh->b_size, offset)) {
2735                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2736                                                          sb->s_blocksize);
2737                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2738                         continue;
2739                 }
2740                 if (le32_to_cpu(de->inode)) {
2741                         brelse(bh);
2742                         return false;
2743                 }
2744                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2745                 de = ext4_next_entry(de, sb->s_blocksize);
2746         }
2747         brelse(bh);
2748         return true;
2749 }
2750
2751 /*
2752  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2753  * such inodes, starting at the superblock, in case we crash before the
2754  * file is closed/deleted, or in case the inode truncate spans multiple
2755  * transactions and the last transaction is not recovered after a crash.
2756  *
2757  * At filesystem recovery time, we walk this list deleting unlinked
2758  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2759  *
2760  * Orphan list manipulation functions must be called under i_mutex unless
2761  * we are just creating the inode or deleting it.
2762  */
2763 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2764 {
2765         struct super_block *sb = inode->i_sb;
2766         struct ext4_sb_info *sbi = EXT4_SB(sb);
2767         struct ext4_iloc iloc;
2768         int err = 0, rc;
2769         bool dirty = false;
2770
2771         if (!sbi->s_journal || is_bad_inode(inode))
2772                 return 0;
2773
2774         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2775                      !inode_is_locked(inode));
2776         /*
2777          * Exit early if inode already is on orphan list. This is a big speedup
2778          * since we don't have to contend on the global s_orphan_lock.
2779          */
2780         if (!list_empty(&EXT4_I(inode)->i_orphan))
2781                 return 0;
2782
2783         /*
2784          * Orphan handling is only valid for files with data blocks
2785          * being truncated, or files being unlinked. Note that we either
2786          * hold i_mutex, or the inode can not be referenced from outside,
2787          * so i_nlink should not be bumped due to race
2788          */
2789         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2790                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2791
2792         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2793         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2794         if (err)
2795                 goto out;
2796
2797         err = ext4_reserve_inode_write(handle, inode, &iloc);
2798         if (err)
2799                 goto out;
2800
2801         mutex_lock(&sbi->s_orphan_lock);
2802         /*
2803          * Due to previous errors inode may be already a part of on-disk
2804          * orphan list. If so skip on-disk list modification.
2805          */
2806         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2807             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2808                 /* Insert this inode at the head of the on-disk orphan list */
2809                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2810                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2811                 dirty = true;
2812         }
2813         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2814         mutex_unlock(&sbi->s_orphan_lock);
2815
2816         if (dirty) {
2817                 err = ext4_handle_dirty_super(handle, sb);
2818                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2819                 if (!err)
2820                         err = rc;
2821                 if (err) {
2822                         /*
2823                          * We have to remove inode from in-memory list if
2824                          * addition to on disk orphan list failed. Stray orphan
2825                          * list entries can cause panics at unmount time.
2826                          */
2827                         mutex_lock(&sbi->s_orphan_lock);
2828                         list_del_init(&EXT4_I(inode)->i_orphan);
2829                         mutex_unlock(&sbi->s_orphan_lock);
2830                 }
2831         }
2832         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2833         jbd_debug(4, "orphan inode %lu will point to %d\n",
2834                         inode->i_ino, NEXT_ORPHAN(inode));
2835 out:
2836         ext4_std_error(sb, err);
2837         return err;
2838 }
2839
2840 /*
2841  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2842  * of such inodes stored on disk, because it is finally being cleaned up.
2843  */
2844 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2845 {
2846         struct list_head *prev;
2847         struct ext4_inode_info *ei = EXT4_I(inode);
2848         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2849         __u32 ino_next;
2850         struct ext4_iloc iloc;
2851         int err = 0;
2852
2853         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2854                 return 0;
2855
2856         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2857                      !inode_is_locked(inode));
2858         /* Do this quick check before taking global s_orphan_lock. */
2859         if (list_empty(&ei->i_orphan))
2860                 return 0;
2861
2862         if (handle) {
2863                 /* Grab inode buffer early before taking global s_orphan_lock */
2864                 err = ext4_reserve_inode_write(handle, inode, &iloc);
2865         }
2866
2867         mutex_lock(&sbi->s_orphan_lock);
2868         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2869
2870         prev = ei->i_orphan.prev;
2871         list_del_init(&ei->i_orphan);
2872
2873         /* If we're on an error path, we may not have a valid
2874          * transaction handle with which to update the orphan list on
2875          * disk, but we still need to remove the inode from the linked
2876          * list in memory. */
2877         if (!handle || err) {
2878                 mutex_unlock(&sbi->s_orphan_lock);
2879                 goto out_err;
2880         }
2881
2882         ino_next = NEXT_ORPHAN(inode);
2883         if (prev == &sbi->s_orphan) {
2884                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2885                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2886                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2887                 if (err) {
2888                         mutex_unlock(&sbi->s_orphan_lock);
2889                         goto out_brelse;
2890                 }
2891                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2892                 mutex_unlock(&sbi->s_orphan_lock);
2893                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2894         } else {
2895                 struct ext4_iloc iloc2;
2896                 struct inode *i_prev =
2897                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2898
2899                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2900                           i_prev->i_ino, ino_next);
2901                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2902                 if (err) {
2903                         mutex_unlock(&sbi->s_orphan_lock);
2904                         goto out_brelse;
2905                 }
2906                 NEXT_ORPHAN(i_prev) = ino_next;
2907                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2908                 mutex_unlock(&sbi->s_orphan_lock);
2909         }
2910         if (err)
2911                 goto out_brelse;
2912         NEXT_ORPHAN(inode) = 0;
2913         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2914 out_err:
2915         ext4_std_error(inode->i_sb, err);
2916         return err;
2917
2918 out_brelse:
2919         brelse(iloc.bh);
2920         goto out_err;
2921 }
2922
2923 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2924 {
2925         int retval;
2926         struct inode *inode;
2927         struct buffer_head *bh;
2928         struct ext4_dir_entry_2 *de;
2929         handle_t *handle = NULL;
2930
2931         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
2932                 return -EIO;
2933
2934         /* Initialize quotas before so that eventual writes go in
2935          * separate transaction */
2936         retval = dquot_initialize(dir);
2937         if (retval)
2938                 return retval;
2939         retval = dquot_initialize(d_inode(dentry));
2940         if (retval)
2941                 return retval;
2942
2943         retval = -ENOENT;
2944         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2945         if (IS_ERR(bh))
2946                 return PTR_ERR(bh);
2947         if (!bh)
2948                 goto end_rmdir;
2949
2950         inode = d_inode(dentry);
2951
2952         retval = -EFSCORRUPTED;
2953         if (le32_to_cpu(de->inode) != inode->i_ino)
2954                 goto end_rmdir;
2955
2956         retval = -ENOTEMPTY;
2957         if (!ext4_empty_dir(inode))
2958                 goto end_rmdir;
2959
2960         handle = ext4_journal_start(dir, EXT4_HT_DIR,
2961                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2962         if (IS_ERR(handle)) {
2963                 retval = PTR_ERR(handle);
2964                 handle = NULL;
2965                 goto end_rmdir;
2966         }
2967
2968         if (IS_DIRSYNC(dir))
2969                 ext4_handle_sync(handle);
2970
2971         retval = ext4_delete_entry(handle, dir, de, bh);
2972         if (retval)
2973                 goto end_rmdir;
2974         if (!EXT4_DIR_LINK_EMPTY(inode))
2975                 ext4_warning_inode(inode,
2976                              "empty directory '%.*s' has too many links (%u)",
2977                              dentry->d_name.len, dentry->d_name.name,
2978                              inode->i_nlink);
2979         inode->i_version++;
2980         clear_nlink(inode);
2981         /* There's no need to set i_disksize: the fact that i_nlink is
2982          * zero will ensure that the right thing happens during any
2983          * recovery. */
2984         inode->i_size = 0;
2985         ext4_orphan_add(handle, inode);
2986         inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
2987         ext4_mark_inode_dirty(handle, inode);
2988         ext4_dec_count(handle, dir);
2989         ext4_update_dx_flag(dir);
2990         ext4_mark_inode_dirty(handle, dir);
2991
2992 end_rmdir:
2993         brelse(bh);
2994         if (handle)
2995                 ext4_journal_stop(handle);
2996         return retval;
2997 }
2998
2999 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3000 {
3001         int retval;
3002         struct inode *inode;
3003         struct buffer_head *bh;
3004         struct ext4_dir_entry_2 *de;
3005         handle_t *handle = NULL;
3006
3007         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3008                 return -EIO;
3009
3010         trace_ext4_unlink_enter(dir, dentry);
3011         /* Initialize quotas before so that eventual writes go
3012          * in separate transaction */
3013         retval = dquot_initialize(dir);
3014         if (retval)
3015                 return retval;
3016         retval = dquot_initialize(d_inode(dentry));
3017         if (retval)
3018                 return retval;
3019
3020         retval = -ENOENT;
3021         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3022         if (IS_ERR(bh))
3023                 return PTR_ERR(bh);
3024         if (!bh)
3025                 goto end_unlink;
3026
3027         inode = d_inode(dentry);
3028
3029         retval = -EFSCORRUPTED;
3030         if (le32_to_cpu(de->inode) != inode->i_ino)
3031                 goto end_unlink;
3032
3033         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3034                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3035         if (IS_ERR(handle)) {
3036                 retval = PTR_ERR(handle);
3037                 handle = NULL;
3038                 goto end_unlink;
3039         }
3040
3041         if (IS_DIRSYNC(dir))
3042                 ext4_handle_sync(handle);
3043
3044         if (inode->i_nlink == 0) {
3045                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3046                                    dentry->d_name.len, dentry->d_name.name);
3047                 set_nlink(inode, 1);
3048         }
3049         retval = ext4_delete_entry(handle, dir, de, bh);
3050         if (retval)
3051                 goto end_unlink;
3052         dir->i_ctime = dir->i_mtime = current_time(dir);
3053         ext4_update_dx_flag(dir);
3054         ext4_mark_inode_dirty(handle, dir);
3055         drop_nlink(inode);
3056         if (!inode->i_nlink)
3057                 ext4_orphan_add(handle, inode);
3058         inode->i_ctime = current_time(inode);
3059         ext4_mark_inode_dirty(handle, inode);
3060
3061 end_unlink:
3062         brelse(bh);
3063         if (handle)
3064                 ext4_journal_stop(handle);
3065         trace_ext4_unlink_exit(dentry, retval);
3066         return retval;
3067 }
3068
3069 static int ext4_symlink(struct inode *dir,
3070                         struct dentry *dentry, const char *symname)
3071 {
3072         handle_t *handle;
3073         struct inode *inode;
3074         int err, len = strlen(symname);
3075         int credits;
3076         bool encryption_required;
3077         struct fscrypt_str disk_link;
3078         struct fscrypt_symlink_data *sd = NULL;
3079
3080         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3081                 return -EIO;
3082
3083         disk_link.len = len + 1;
3084         disk_link.name = (char *) symname;
3085
3086         encryption_required = (ext4_encrypted_inode(dir) ||
3087                                DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3088         if (encryption_required) {
3089                 err = fscrypt_get_encryption_info(dir);
3090                 if (err)
3091                         return err;
3092                 if (!fscrypt_has_encryption_key(dir))
3093                         return -ENOKEY;
3094                 disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
3095                                  sizeof(struct fscrypt_symlink_data));
3096                 sd = kzalloc(disk_link.len, GFP_KERNEL);
3097                 if (!sd)
3098                         return -ENOMEM;
3099         }
3100
3101         if (disk_link.len > dir->i_sb->s_blocksize) {
3102                 err = -ENAMETOOLONG;
3103                 goto err_free_sd;
3104         }
3105
3106         err = dquot_initialize(dir);
3107         if (err)
3108                 goto err_free_sd;
3109
3110         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3111                 /*
3112                  * For non-fast symlinks, we just allocate inode and put it on
3113                  * orphan list in the first transaction => we need bitmap,
3114                  * group descriptor, sb, inode block, quota blocks, and
3115                  * possibly selinux xattr blocks.
3116                  */
3117                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3118                           EXT4_XATTR_TRANS_BLOCKS;
3119         } else {
3120                 /*
3121                  * Fast symlink. We have to add entry to directory
3122                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3123                  * allocate new inode (bitmap, group descriptor, inode block,
3124                  * quota blocks, sb is already counted in previous macros).
3125                  */
3126                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3127                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3128         }
3129
3130         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3131                                             &dentry->d_name, 0, NULL,
3132                                             EXT4_HT_DIR, credits);
3133         handle = ext4_journal_current_handle();
3134         if (IS_ERR(inode)) {
3135                 if (handle)
3136                         ext4_journal_stop(handle);
3137                 err = PTR_ERR(inode);
3138                 goto err_free_sd;
3139         }
3140
3141         if (encryption_required) {
3142                 struct qstr istr;
3143                 struct fscrypt_str ostr =
3144                         FSTR_INIT(sd->encrypted_path, disk_link.len);
3145
3146                 istr.name = (const unsigned char *) symname;
3147                 istr.len = len;
3148                 err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
3149                 if (err)
3150                         goto err_drop_inode;
3151                 sd->len = cpu_to_le16(ostr.len);
3152                 disk_link.name = (char *) sd;
3153                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3154         }
3155
3156         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3157                 if (!encryption_required)
3158                         inode->i_op = &ext4_symlink_inode_operations;
3159                 inode_nohighmem(inode);
3160                 ext4_set_aops(inode);
3161                 /*
3162                  * We cannot call page_symlink() with transaction started
3163                  * because it calls into ext4_write_begin() which can wait
3164                  * for transaction commit if we are running out of space
3165                  * and thus we deadlock. So we have to stop transaction now
3166                  * and restart it when symlink contents is written.
3167                  *
3168                  * To keep fs consistent in case of crash, we have to put inode
3169                  * to orphan list in the mean time.
3170                  */
3171                 drop_nlink(inode);
3172                 err = ext4_orphan_add(handle, inode);
3173                 ext4_journal_stop(handle);
3174                 handle = NULL;
3175                 if (err)
3176                         goto err_drop_inode;
3177                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3178                 if (err)
3179                         goto err_drop_inode;
3180                 /*
3181                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3182                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3183                  */
3184                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3185                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3186                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3187                 if (IS_ERR(handle)) {
3188                         err = PTR_ERR(handle);
3189                         handle = NULL;
3190                         goto err_drop_inode;
3191                 }
3192                 set_nlink(inode, 1);
3193                 err = ext4_orphan_del(handle, inode);
3194                 if (err)
3195                         goto err_drop_inode;
3196         } else {
3197                 /* clear the extent format for fast symlink */
3198                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3199                 if (!encryption_required) {
3200                         inode->i_op = &ext4_fast_symlink_inode_operations;
3201                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3202                 }
3203                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3204                        disk_link.len);
3205                 inode->i_size = disk_link.len - 1;
3206         }
3207         EXT4_I(inode)->i_disksize = inode->i_size;
3208         err = ext4_add_nondir(handle, dentry, inode);
3209         if (!err && IS_DIRSYNC(dir))
3210                 ext4_handle_sync(handle);
3211
3212         if (handle)
3213                 ext4_journal_stop(handle);
3214         kfree(sd);
3215         return err;
3216 err_drop_inode:
3217         if (handle)
3218                 ext4_journal_stop(handle);
3219         clear_nlink(inode);
3220         unlock_new_inode(inode);
3221         iput(inode);
3222 err_free_sd:
3223         kfree(sd);
3224         return err;
3225 }
3226
3227 static int ext4_link(struct dentry *old_dentry,
3228                      struct inode *dir, struct dentry *dentry)
3229 {
3230         handle_t *handle;
3231         struct inode *inode = d_inode(old_dentry);
3232         int err, retries = 0;
3233
3234         if (inode->i_nlink >= EXT4_LINK_MAX)
3235                 return -EMLINK;
3236         if (ext4_encrypted_inode(dir) &&
3237                         !fscrypt_has_permitted_context(dir, inode))
3238                 return -EPERM;
3239
3240        if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3241            (!projid_eq(EXT4_I(dir)->i_projid,
3242                        EXT4_I(old_dentry->d_inode)->i_projid)))
3243                 return -EXDEV;
3244
3245         err = dquot_initialize(dir);
3246         if (err)
3247                 return err;
3248
3249 retry:
3250         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3251                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3252                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3253         if (IS_ERR(handle))
3254                 return PTR_ERR(handle);
3255
3256         if (IS_DIRSYNC(dir))
3257                 ext4_handle_sync(handle);
3258
3259         inode->i_ctime = current_time(inode);
3260         ext4_inc_count(handle, inode);
3261         ihold(inode);
3262
3263         err = ext4_add_entry(handle, dentry, inode);
3264         if (!err) {
3265                 ext4_mark_inode_dirty(handle, inode);
3266                 /* this can happen only for tmpfile being
3267                  * linked the first time
3268                  */
3269                 if (inode->i_nlink == 1)
3270                         ext4_orphan_del(handle, inode);
3271                 d_instantiate(dentry, inode);
3272         } else {
3273                 drop_nlink(inode);
3274                 iput(inode);
3275         }
3276         ext4_journal_stop(handle);
3277         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3278                 goto retry;
3279         return err;
3280 }
3281
3282
3283 /*
3284  * Try to find buffer head where contains the parent block.
3285  * It should be the inode block if it is inlined or the 1st block
3286  * if it is a normal dir.
3287  */
3288 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3289                                         struct inode *inode,
3290                                         int *retval,
3291                                         struct ext4_dir_entry_2 **parent_de,
3292                                         int *inlined)
3293 {
3294         struct buffer_head *bh;
3295
3296         if (!ext4_has_inline_data(inode)) {
3297                 bh = ext4_read_dirblock(inode, 0, EITHER);
3298                 if (IS_ERR(bh)) {
3299                         *retval = PTR_ERR(bh);
3300                         return NULL;
3301                 }
3302                 *parent_de = ext4_next_entry(
3303                                         (struct ext4_dir_entry_2 *)bh->b_data,
3304                                         inode->i_sb->s_blocksize);
3305                 return bh;
3306         }
3307
3308         *inlined = 1;
3309         return ext4_get_first_inline_block(inode, parent_de, retval);
3310 }
3311
3312 struct ext4_renament {
3313         struct inode *dir;
3314         struct dentry *dentry;
3315         struct inode *inode;
3316         bool is_dir;
3317         int dir_nlink_delta;
3318
3319         /* entry for "dentry" */
3320         struct buffer_head *bh;
3321         struct ext4_dir_entry_2 *de;
3322         int inlined;
3323
3324         /* entry for ".." in inode if it's a directory */
3325         struct buffer_head *dir_bh;
3326         struct ext4_dir_entry_2 *parent_de;
3327         int dir_inlined;
3328 };
3329
3330 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3331 {
3332         int retval;
3333
3334         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3335                                               &retval, &ent->parent_de,
3336                                               &ent->dir_inlined);
3337         if (!ent->dir_bh)
3338                 return retval;
3339         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3340                 return -EFSCORRUPTED;
3341         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3342         return ext4_journal_get_write_access(handle, ent->dir_bh);
3343 }
3344
3345 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3346                                   unsigned dir_ino)
3347 {
3348         int retval;
3349
3350         ent->parent_de->inode = cpu_to_le32(dir_ino);
3351         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3352         if (!ent->dir_inlined) {
3353                 if (is_dx(ent->inode)) {
3354                         retval = ext4_handle_dirty_dx_node(handle,
3355                                                            ent->inode,
3356                                                            ent->dir_bh);
3357                 } else {
3358                         retval = ext4_handle_dirty_dirent_node(handle,
3359                                                                ent->inode,
3360                                                                ent->dir_bh);
3361                 }
3362         } else {
3363                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3364         }
3365         if (retval) {
3366                 ext4_std_error(ent->dir->i_sb, retval);
3367                 return retval;
3368         }
3369         return 0;
3370 }
3371
3372 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3373                        unsigned ino, unsigned file_type)
3374 {
3375         int retval;
3376
3377         BUFFER_TRACE(ent->bh, "get write access");
3378         retval = ext4_journal_get_write_access(handle, ent->bh);
3379         if (retval)
3380                 return retval;
3381         ent->de->inode = cpu_to_le32(ino);
3382         if (ext4_has_feature_filetype(ent->dir->i_sb))
3383                 ent->de->file_type = file_type;
3384         ent->dir->i_version++;
3385         ent->dir->i_ctime = ent->dir->i_mtime =
3386                 current_time(ent->dir);
3387         ext4_mark_inode_dirty(handle, ent->dir);
3388         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3389         if (!ent->inlined) {
3390                 retval = ext4_handle_dirty_dirent_node(handle,
3391                                                        ent->dir, ent->bh);
3392                 if (unlikely(retval)) {
3393                         ext4_std_error(ent->dir->i_sb, retval);
3394                         return retval;
3395                 }
3396         }
3397         brelse(ent->bh);
3398         ent->bh = NULL;
3399
3400         return 0;
3401 }
3402
3403 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3404                                   const struct qstr *d_name)
3405 {
3406         int retval = -ENOENT;
3407         struct buffer_head *bh;
3408         struct ext4_dir_entry_2 *de;
3409
3410         bh = ext4_find_entry(dir, d_name, &de, NULL);
3411         if (IS_ERR(bh))
3412                 return PTR_ERR(bh);
3413         if (bh) {
3414                 retval = ext4_delete_entry(handle, dir, de, bh);
3415                 brelse(bh);
3416         }
3417         return retval;
3418 }
3419
3420 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3421                                int force_reread)
3422 {
3423         int retval;
3424         /*
3425          * ent->de could have moved from under us during htree split, so make
3426          * sure that we are deleting the right entry.  We might also be pointing
3427          * to a stale entry in the unused part of ent->bh so just checking inum
3428          * and the name isn't enough.
3429          */
3430         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3431             ent->de->name_len != ent->dentry->d_name.len ||
3432             strncmp(ent->de->name, ent->dentry->d_name.name,
3433                     ent->de->name_len) ||
3434             force_reread) {
3435                 retval = ext4_find_delete_entry(handle, ent->dir,
3436                                                 &ent->dentry->d_name);
3437         } else {
3438                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3439                 if (retval == -ENOENT) {
3440                         retval = ext4_find_delete_entry(handle, ent->dir,
3441                                                         &ent->dentry->d_name);
3442                 }
3443         }
3444
3445         if (retval) {
3446                 ext4_warning_inode(ent->dir,
3447                                    "Deleting old file: nlink %d, error=%d",
3448                                    ent->dir->i_nlink, retval);
3449         }
3450 }
3451
3452 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3453 {
3454         if (ent->dir_nlink_delta) {
3455                 if (ent->dir_nlink_delta == -1)
3456                         ext4_dec_count(handle, ent->dir);
3457                 else
3458                         ext4_inc_count(handle, ent->dir);
3459                 ext4_mark_inode_dirty(handle, ent->dir);
3460         }
3461 }
3462
3463 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3464                                               int credits, handle_t **h)
3465 {
3466         struct inode *wh;
3467         handle_t *handle;
3468         int retries = 0;
3469
3470         /*
3471          * for inode block, sb block, group summaries,
3472          * and inode bitmap
3473          */
3474         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3475                     EXT4_XATTR_TRANS_BLOCKS + 4);
3476 retry:
3477         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3478                                          &ent->dentry->d_name, 0, NULL,
3479                                          EXT4_HT_DIR, credits);
3480
3481         handle = ext4_journal_current_handle();
3482         if (IS_ERR(wh)) {
3483                 if (handle)
3484                         ext4_journal_stop(handle);
3485                 if (PTR_ERR(wh) == -ENOSPC &&
3486                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3487                         goto retry;
3488         } else {
3489                 *h = handle;
3490                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3491                 wh->i_op = &ext4_special_inode_operations;
3492         }
3493         return wh;
3494 }
3495
3496 /*
3497  * Anybody can rename anything with this: the permission checks are left to the
3498  * higher-level routines.
3499  *
3500  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3501  * while new_{dentry,inode) refers to the destination dentry/inode
3502  * This comes from rename(const char *oldpath, const char *newpath)
3503  */
3504 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3505                        struct inode *new_dir, struct dentry *new_dentry,
3506                        unsigned int flags)
3507 {
3508         handle_t *handle = NULL;
3509         struct ext4_renament old = {
3510                 .dir = old_dir,
3511                 .dentry = old_dentry,
3512                 .inode = d_inode(old_dentry),
3513         };
3514         struct ext4_renament new = {
3515                 .dir = new_dir,
3516                 .dentry = new_dentry,
3517                 .inode = d_inode(new_dentry),
3518         };
3519         int force_reread;
3520         int retval;
3521         struct inode *whiteout = NULL;
3522         int credits;
3523         u8 old_file_type;
3524
3525         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3526             (!projid_eq(EXT4_I(new_dir)->i_projid,
3527                         EXT4_I(old_dentry->d_inode)->i_projid)))
3528                 return -EXDEV;
3529
3530         if ((ext4_encrypted_inode(old_dir) &&
3531              !fscrypt_has_encryption_key(old_dir)) ||
3532             (ext4_encrypted_inode(new_dir) &&
3533              !fscrypt_has_encryption_key(new_dir)))
3534                 return -ENOKEY;
3535
3536         retval = dquot_initialize(old.dir);
3537         if (retval)
3538                 return retval;
3539         retval = dquot_initialize(new.dir);
3540         if (retval)
3541                 return retval;
3542
3543         /* Initialize quotas before so that eventual writes go
3544          * in separate transaction */
3545         if (new.inode) {
3546                 retval = dquot_initialize(new.inode);
3547                 if (retval)
3548                         return retval;
3549         }
3550
3551         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3552         if (IS_ERR(old.bh))
3553                 return PTR_ERR(old.bh);
3554         /*
3555          *  Check for inode number is _not_ due to possible IO errors.
3556          *  We might rmdir the source, keep it as pwd of some process
3557          *  and merrily kill the link to whatever was created under the
3558          *  same name. Goodbye sticky bit ;-<
3559          */
3560         retval = -ENOENT;
3561         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3562                 goto end_rename;
3563
3564         if ((old.dir != new.dir) &&
3565             ext4_encrypted_inode(new.dir) &&
3566             !fscrypt_has_permitted_context(new.dir, old.inode)) {
3567                 retval = -EPERM;
3568                 goto end_rename;
3569         }
3570
3571         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3572                                  &new.de, &new.inlined);
3573         if (IS_ERR(new.bh)) {
3574                 retval = PTR_ERR(new.bh);
3575                 new.bh = NULL;
3576                 goto end_rename;
3577         }
3578         if (new.bh) {
3579                 if (!new.inode) {
3580                         brelse(new.bh);
3581                         new.bh = NULL;
3582                 }
3583         }
3584         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3585                 ext4_alloc_da_blocks(old.inode);
3586
3587         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3588                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3589         if (!(flags & RENAME_WHITEOUT)) {
3590                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3591                 if (IS_ERR(handle)) {
3592                         retval = PTR_ERR(handle);
3593                         handle = NULL;
3594                         goto end_rename;
3595                 }
3596         } else {
3597                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3598                 if (IS_ERR(whiteout)) {
3599                         retval = PTR_ERR(whiteout);
3600                         whiteout = NULL;
3601                         goto end_rename;
3602                 }
3603         }
3604
3605         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3606                 ext4_handle_sync(handle);
3607
3608         if (S_ISDIR(old.inode->i_mode)) {
3609                 if (new.inode) {
3610                         retval = -ENOTEMPTY;
3611                         if (!ext4_empty_dir(new.inode))
3612                                 goto end_rename;
3613                 } else {
3614                         retval = -EMLINK;
3615                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3616                                 goto end_rename;
3617                 }
3618                 retval = ext4_rename_dir_prepare(handle, &old);
3619                 if (retval)
3620                         goto end_rename;
3621         }
3622         /*
3623          * If we're renaming a file within an inline_data dir and adding or
3624          * setting the new dirent causes a conversion from inline_data to
3625          * extents/blockmap, we need to force the dirent delete code to
3626          * re-read the directory, or else we end up trying to delete a dirent
3627          * from what is now the extent tree root (or a block map).
3628          */
3629         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3630                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3631
3632         old_file_type = old.de->file_type;
3633         if (whiteout) {
3634                 /*
3635                  * Do this before adding a new entry, so the old entry is sure
3636                  * to be still pointing to the valid old entry.
3637                  */
3638                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3639                                      EXT4_FT_CHRDEV);
3640                 if (retval)
3641                         goto end_rename;
3642                 ext4_mark_inode_dirty(handle, whiteout);
3643         }
3644         if (!new.bh) {
3645                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3646                 if (retval)
3647                         goto end_rename;
3648         } else {
3649                 retval = ext4_setent(handle, &new,
3650                                      old.inode->i_ino, old_file_type);
3651                 if (retval)
3652                         goto end_rename;
3653         }
3654         if (force_reread)
3655                 force_reread = !ext4_test_inode_flag(new.dir,
3656                                                      EXT4_INODE_INLINE_DATA);
3657
3658         /*
3659          * Like most other Unix systems, set the ctime for inodes on a
3660          * rename.
3661          */
3662         old.inode->i_ctime = current_time(old.inode);
3663         ext4_mark_inode_dirty(handle, old.inode);
3664
3665         if (!whiteout) {
3666                 /*
3667                  * ok, that's it
3668                  */
3669                 ext4_rename_delete(handle, &old, force_reread);
3670         }
3671
3672         if (new.inode) {
3673                 ext4_dec_count(handle, new.inode);
3674                 new.inode->i_ctime = current_time(new.inode);
3675         }
3676         old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
3677         ext4_update_dx_flag(old.dir);
3678         if (old.dir_bh) {
3679                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3680                 if (retval)
3681                         goto end_rename;
3682
3683                 ext4_dec_count(handle, old.dir);
3684                 if (new.inode) {
3685                         /* checked ext4_empty_dir above, can't have another
3686                          * parent, ext4_dec_count() won't work for many-linked
3687                          * dirs */
3688                         clear_nlink(new.inode);
3689                 } else {
3690                         ext4_inc_count(handle, new.dir);
3691                         ext4_update_dx_flag(new.dir);
3692                         ext4_mark_inode_dirty(handle, new.dir);
3693                 }
3694         }
3695         ext4_mark_inode_dirty(handle, old.dir);
3696         if (new.inode) {
3697                 ext4_mark_inode_dirty(handle, new.inode);
3698                 if (!new.inode->i_nlink)
3699                         ext4_orphan_add(handle, new.inode);
3700         }
3701         retval = 0;
3702
3703 end_rename:
3704         brelse(old.dir_bh);
3705         brelse(old.bh);
3706         brelse(new.bh);
3707         if (whiteout) {
3708                 if (retval)
3709                         drop_nlink(whiteout);
3710                 unlock_new_inode(whiteout);
3711                 iput(whiteout);
3712         }
3713         if (handle)
3714                 ext4_journal_stop(handle);
3715         return retval;
3716 }
3717
3718 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3719                              struct inode *new_dir, struct dentry *new_dentry)
3720 {
3721         handle_t *handle = NULL;
3722         struct ext4_renament old = {
3723                 .dir = old_dir,
3724                 .dentry = old_dentry,
3725                 .inode = d_inode(old_dentry),
3726         };
3727         struct ext4_renament new = {
3728                 .dir = new_dir,
3729                 .dentry = new_dentry,
3730                 .inode = d_inode(new_dentry),
3731         };
3732         u8 new_file_type;
3733         int retval;
3734         struct timespec ctime;
3735
3736         if ((ext4_encrypted_inode(old_dir) &&
3737              !fscrypt_has_encryption_key(old_dir)) ||
3738             (ext4_encrypted_inode(new_dir) &&
3739              !fscrypt_has_encryption_key(new_dir)))
3740                 return -ENOKEY;
3741
3742         if ((ext4_encrypted_inode(old_dir) ||
3743              ext4_encrypted_inode(new_dir)) &&
3744             (old_dir != new_dir) &&
3745             (!fscrypt_has_permitted_context(new_dir, old.inode) ||
3746              !fscrypt_has_permitted_context(old_dir, new.inode)))
3747                 return -EPERM;
3748
3749         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3750              !projid_eq(EXT4_I(new_dir)->i_projid,
3751                         EXT4_I(old_dentry->d_inode)->i_projid)) ||
3752             (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3753              !projid_eq(EXT4_I(old_dir)->i_projid,
3754                         EXT4_I(new_dentry->d_inode)->i_projid)))
3755                 return -EXDEV;
3756
3757         retval = dquot_initialize(old.dir);
3758         if (retval)
3759                 return retval;
3760         retval = dquot_initialize(new.dir);
3761         if (retval)
3762                 return retval;
3763
3764         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3765                                  &old.de, &old.inlined);
3766         if (IS_ERR(old.bh))
3767                 return PTR_ERR(old.bh);
3768         /*
3769          *  Check for inode number is _not_ due to possible IO errors.
3770          *  We might rmdir the source, keep it as pwd of some process
3771          *  and merrily kill the link to whatever was created under the
3772          *  same name. Goodbye sticky bit ;-<
3773          */
3774         retval = -ENOENT;
3775         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3776                 goto end_rename;
3777
3778         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3779                                  &new.de, &new.inlined);
3780         if (IS_ERR(new.bh)) {
3781                 retval = PTR_ERR(new.bh);
3782                 new.bh = NULL;
3783                 goto end_rename;
3784         }
3785
3786         /* RENAME_EXCHANGE case: old *and* new must both exist */
3787         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3788                 goto end_rename;
3789
3790         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3791                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3792                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3793         if (IS_ERR(handle)) {
3794                 retval = PTR_ERR(handle);
3795                 handle = NULL;
3796                 goto end_rename;
3797         }
3798
3799         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3800                 ext4_handle_sync(handle);
3801
3802         if (S_ISDIR(old.inode->i_mode)) {
3803                 old.is_dir = true;
3804                 retval = ext4_rename_dir_prepare(handle, &old);
3805                 if (retval)
3806                         goto end_rename;
3807         }
3808         if (S_ISDIR(new.inode->i_mode)) {
3809                 new.is_dir = true;
3810                 retval = ext4_rename_dir_prepare(handle, &new);
3811                 if (retval)
3812                         goto end_rename;
3813         }
3814
3815         /*
3816          * Other than the special case of overwriting a directory, parents'
3817          * nlink only needs to be modified if this is a cross directory rename.
3818          */
3819         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3820                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3821                 new.dir_nlink_delta = -old.dir_nlink_delta;
3822                 retval = -EMLINK;
3823                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3824                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3825                         goto end_rename;
3826         }
3827
3828         new_file_type = new.de->file_type;
3829         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3830         if (retval)
3831                 goto end_rename;
3832
3833         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3834         if (retval)
3835                 goto end_rename;
3836
3837         /*
3838          * Like most other Unix systems, set the ctime for inodes on a
3839          * rename.
3840          */
3841         ctime = current_time(old.inode);
3842         old.inode->i_ctime = ctime;
3843         new.inode->i_ctime = ctime;
3844         ext4_mark_inode_dirty(handle, old.inode);
3845         ext4_mark_inode_dirty(handle, new.inode);
3846
3847         if (old.dir_bh) {
3848                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3849                 if (retval)
3850                         goto end_rename;
3851         }
3852         if (new.dir_bh) {
3853                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3854                 if (retval)
3855                         goto end_rename;
3856         }
3857         ext4_update_dir_count(handle, &old);
3858         ext4_update_dir_count(handle, &new);
3859         retval = 0;
3860
3861 end_rename:
3862         brelse(old.dir_bh);
3863         brelse(new.dir_bh);
3864         brelse(old.bh);
3865         brelse(new.bh);
3866         if (handle)
3867                 ext4_journal_stop(handle);
3868         return retval;
3869 }
3870
3871 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3872                         struct inode *new_dir, struct dentry *new_dentry,
3873                         unsigned int flags)
3874 {
3875         if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
3876                 return -EIO;
3877
3878         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3879                 return -EINVAL;
3880
3881         if (flags & RENAME_EXCHANGE) {
3882                 return ext4_cross_rename(old_dir, old_dentry,
3883                                          new_dir, new_dentry);
3884         }
3885
3886         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3887 }
3888
3889 /*
3890  * directories can handle most operations...
3891  */
3892 const struct inode_operations ext4_dir_inode_operations = {
3893         .create         = ext4_create,
3894         .lookup         = ext4_lookup,
3895         .link           = ext4_link,
3896         .unlink         = ext4_unlink,
3897         .symlink        = ext4_symlink,
3898         .mkdir          = ext4_mkdir,
3899         .rmdir          = ext4_rmdir,
3900         .mknod          = ext4_mknod,
3901         .tmpfile        = ext4_tmpfile,
3902         .rename         = ext4_rename2,
3903         .setattr        = ext4_setattr,
3904         .getattr        = ext4_getattr,
3905         .listxattr      = ext4_listxattr,
3906         .get_acl        = ext4_get_acl,
3907         .set_acl        = ext4_set_acl,
3908         .fiemap         = ext4_fiemap,
3909 };
3910
3911 const struct inode_operations ext4_special_inode_operations = {
3912         .setattr        = ext4_setattr,
3913         .getattr        = ext4_getattr,
3914         .listxattr      = ext4_listxattr,
3915         .get_acl        = ext4_get_acl,
3916         .set_acl        = ext4_set_acl,
3917 };