fs/ext4/namei.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/ext4/namei.c
   4  *
   5  * Copyright (C) 1992, 1993, 1994, 1995
   6  * Remy Card ([email protected])
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  *
  10  *  from
  11  *
  12  *  linux/fs/minix/namei.c
  13  *
  14  *  Copyright (C) 1991, 1992  Linus Torvalds
  15  *
  16  *  Big-endian to little-endian byte-swapping/bitmaps by
  17  *        David S. Miller ([email protected]), 1995
  18  *  Directory entry file type support and forward compatibility hooks
  19  *      for B-tree directories by Theodore Ts'o ([email protected]), 1998
  20  *  Hash Tree Directory indexing (c)
  21  *      Daniel Phillips, 2001
  22  *  Hash Tree Directory indexing porting
  23  *      Christopher Li, 2002
  24  *  Hash Tree Directory indexing cleanup
  25  *      Theodore Ts'o, 2002
  26  */
  27
  28 #include <linux/fs.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/time.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/stat.h>
  33 #include <linux/string.h>
  34 #include <linux/quotaops.h>
  35 #include <linux/buffer_head.h>
  36 #include <linux/bio.h>
  37 #include <linux/iversion.h>
  38 #include <linux/unicode.h>
  39 #include "ext4.h"
  40 #include "ext4_jbd2.h"
  41
  42 #include "xattr.h"
  43 #include "acl.h"
  44
  45 #include <trace/events/ext4.h>
  46 /*
  47  * define how far ahead to read directories while searching them.
  48  */
  49 #define NAMEI_RA_CHUNKS  2
  50 #define NAMEI_RA_BLOCKS  4
  51 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  52
  53 static struct buffer_head *ext4_append(handle_t *handle,
  54                                         struct inode *inode,
  55                                         ext4_lblk_t *block)
  56 {
  57         struct buffer_head *bh;
  58         int err;
  59
  60         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  61                      ((inode->i_size >> 10) >=
  62                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
  63                 return ERR_PTR(-ENOSPC);
  64
  65         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  66
  67         bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
  68         if (IS_ERR(bh))
  69                 return bh;
  70         inode->i_size += inode->i_sb->s_blocksize;
  71         EXT4_I(inode)->i_disksize = inode->i_size;
  72         BUFFER_TRACE(bh, "get_write_access");
  73         err = ext4_journal_get_write_access(handle, bh);
  74         if (err) {
  75                 brelse(bh);
  76                 ext4_std_error(inode->i_sb, err);
  77                 return ERR_PTR(err);
  78         }
  79         return bh;
  80 }
  81
  82 static int ext4_dx_csum_verify(struct inode *inode,
  83                                struct ext4_dir_entry *dirent);
  84
  85 /*
  86  * Hints to ext4_read_dirblock regarding whether we expect a directory
  87  * block being read to be an index block, or a block containing
  88  * directory entries (and if the latter, whether it was found via a
  89  * logical block in an htree index block).  This is used to control
  90  * what sort of sanity checkinig ext4_read_dirblock() will do on the
  91  * directory block read from the storage device.  EITHER will means
  92  * the caller doesn't know what kind of directory block will be read,
  93  * so no specific verification will be done.
  94  */
  95 typedef enum {
  96         EITHER, INDEX, DIRENT, DIRENT_HTREE
  97 } dirblock_type_t;
  98
  99 #define ext4_read_dirblock(inode, block, type) \
 100         __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
 101
 102 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 103                                                 ext4_lblk_t block,
 104                                                 dirblock_type_t type,
 105                                                 const char *func,
 106                                                 unsigned int line)
 107 {
 108         struct buffer_head *bh;
 109         struct ext4_dir_entry *dirent;
 110         int is_dx_block = 0;
 111
 112         if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO))
 113                 bh = ERR_PTR(-EIO);
 114         else
 115                 bh = ext4_bread(NULL, inode, block, 0);
 116         if (IS_ERR(bh)) {
 117                 __ext4_warning(inode->i_sb, func, line,
 118                                "inode #%lu: lblock %lu: comm %s: "
 119                                "error %ld reading directory block",
 120                                inode->i_ino, (unsigned long)block,
 121                                current->comm, PTR_ERR(bh));
 122
 123                 return bh;
 124         }
 125         if (!bh && (type == INDEX || type == DIRENT_HTREE)) {
 126                 ext4_error_inode(inode, func, line, block,
 127                                  "Directory hole found for htree %s block",
 128                                  (type == INDEX) ? "index" : "leaf");
 129                 return ERR_PTR(-EFSCORRUPTED);
 130         }
 131         if (!bh)
 132                 return NULL;
 133         dirent = (struct ext4_dir_entry *) bh->b_data;
 134         /* Determine whether or not we have an index block */
 135         if (is_dx(inode)) {
 136                 if (block == 0)
 137                         is_dx_block = 1;
 138                 else if (ext4_rec_len_from_disk(dirent->rec_len,
 139                                                 inode->i_sb->s_blocksize) ==
 140                          inode->i_sb->s_blocksize)
 141                         is_dx_block = 1;
 142         }
 143         if (!is_dx_block && type == INDEX) {
 144                 ext4_error_inode(inode, func, line, block,
 145                        "directory leaf block found instead of index block");
 146                 brelse(bh);
 147                 return ERR_PTR(-EFSCORRUPTED);
 148         }
 149         if (!ext4_has_metadata_csum(inode->i_sb) ||
 150             buffer_verified(bh))
 151                 return bh;
 152
 153         /*
 154          * An empty leaf block can get mistaken for a index block; for
 155          * this reason, we can only check the index checksum when the
 156          * caller is sure it should be an index block.
 157          */
 158         if (is_dx_block && type == INDEX) {
 159                 if (ext4_dx_csum_verify(inode, dirent) &&
 160                     !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
 161                         set_buffer_verified(bh);
 162                 else {
 163                         ext4_error_inode_err(inode, func, line, block,
 164                                              EFSBADCRC,
 165                                              "Directory index failed checksum");
 166                         brelse(bh);
 167                         return ERR_PTR(-EFSBADCRC);
 168                 }
 169         }
 170         if (!is_dx_block) {
 171                 if (ext4_dirblock_csum_verify(inode, bh) &&
 172                     !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
 173                         set_buffer_verified(bh);
 174                 else {
 175                         ext4_error_inode_err(inode, func, line, block,
 176                                              EFSBADCRC,
 177                                              "Directory block failed checksum");
 178                         brelse(bh);
 179                         return ERR_PTR(-EFSBADCRC);
 180                 }
 181         }
 182         return bh;
 183 }
 184
 185 #ifndef assert
 186 #define assert(test) J_ASSERT(test)
 187 #endif
 188
 189 #ifdef DX_DEBUG
 190 #define dxtrace(command) command
 191 #else
 192 #define dxtrace(command)
 193 #endif
 194
 195 struct fake_dirent
 196 {
 197         __le32 inode;
 198         __le16 rec_len;
 199         u8 name_len;
 200         u8 file_type;
 201 };
 202
 203 struct dx_countlimit
 204 {
 205         __le16 limit;
 206         __le16 count;
 207 };
 208
 209 struct dx_entry
 210 {
 211         __le32 hash;
 212         __le32 block;
 213 };
 214
 215 /*
 216  * dx_root_info is laid out so that if it should somehow get overlaid by a
 217  * dirent the two low bits of the hash version will be zero.  Therefore, the
 218  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 219  */
 220
 221 struct dx_root
 222 {
 223         struct fake_dirent dot;
 224         char dot_name[4];
 225         struct fake_dirent dotdot;
 226         char dotdot_name[4];
 227         struct dx_root_info
 228         {
 229                 __le32 reserved_zero;
 230                 u8 hash_version;
 231                 u8 info_length; /* 8 */
 232                 u8 indirect_levels;
 233                 u8 unused_flags;
 234         }
 235         info;
 236         struct dx_entry entries[];
 237 };
 238
 239 struct dx_node
 240 {
 241         struct fake_dirent fake;
 242         struct dx_entry entries[];
 243 };
 244
 245
 246 struct dx_frame
 247 {
 248         struct buffer_head *bh;
 249         struct dx_entry *entries;
 250         struct dx_entry *at;
 251 };
 252
 253 struct dx_map_entry
 254 {
 255         u32 hash;
 256         u16 offs;
 257         u16 size;
 258 };
 259
 260 /*
 261  * This goes at the end of each htree block.
 262  */
 263 struct dx_tail {
 264         u32 dt_reserved;
 265         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 266 };
 267
 268 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 269 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 270 static inline unsigned dx_get_hash(struct dx_entry *entry);
 271 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 272 static unsigned dx_get_count(struct dx_entry *entries);
 273 static unsigned dx_get_limit(struct dx_entry *entries);
 274 static void dx_set_count(struct dx_entry *entries, unsigned value);
 275 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 276 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 277 static unsigned dx_node_limit(struct inode *dir);
 278 static struct dx_frame *dx_probe(struct ext4_filename *fname,
 279                                  struct inode *dir,
 280                                  struct dx_hash_info *hinfo,
 281                                  struct dx_frame *frame);
 282 static void dx_release(struct dx_frame *frames);
 283 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 284                        unsigned blocksize, struct dx_hash_info *hinfo,
 285                        struct dx_map_entry map[]);
 286 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 287 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 288                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 289 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 290 static void dx_insert_block(struct dx_frame *frame,
 291                                         u32 hash, ext4_lblk_t block);
 292 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 293                                  struct dx_frame *frame,
 294                                  struct dx_frame *frames,
 295                                  __u32 *start_hash);
 296 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 297                 struct ext4_filename *fname,
 298                 struct ext4_dir_entry_2 **res_dir);
 299 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 300                              struct inode *dir, struct inode *inode);
 301
 302 /* checksumming functions */
 303 void ext4_initialize_dirent_tail(struct buffer_head *bh,
 304                                  unsigned int blocksize)
 305 {
 306         struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
 307
 308         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 309         t->det_rec_len = ext4_rec_len_to_disk(
 310                         sizeof(struct ext4_dir_entry_tail), blocksize);
 311         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 312 }
 313
 314 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 315 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 316                                                    struct buffer_head *bh)
 317 {
 318         struct ext4_dir_entry_tail *t;
 319
 320 #ifdef PARANOID
 321         struct ext4_dir_entry *d, *top;
 322
 323         d = (struct ext4_dir_entry *)bh->b_data;
 324         top = (struct ext4_dir_entry *)(bh->b_data +
 325                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 326                  sizeof(struct ext4_dir_entry_tail)));
 327         while (d < top && d->rec_len)
 328                 d = (struct ext4_dir_entry *)(((void *)d) +
 329                     le16_to_cpu(d->rec_len));
 330
 331         if (d != top)
 332                 return NULL;
 333
 334         t = (struct ext4_dir_entry_tail *)d;
 335 #else
 336         t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
 337 #endif
 338
 339         if (t->det_reserved_zero1 ||
 340             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 341             t->det_reserved_zero2 ||
 342             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 343                 return NULL;
 344
 345         return t;
 346 }
 347
 348 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
 349 {
 350         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 351         struct ext4_inode_info *ei = EXT4_I(inode);
 352         __u32 csum;
 353
 354         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 355         return cpu_to_le32(csum);
 356 }
 357
 358 #define warn_no_space_for_csum(inode)                                   \
 359         __warn_no_space_for_csum((inode), __func__, __LINE__)
 360
 361 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
 362                                      unsigned int line)
 363 {
 364         __ext4_warning_inode(inode, func, line,
 365                 "No space for directory leaf checksum. Please run e2fsck -D.");
 366 }
 367
 368 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
 369 {
 370         struct ext4_dir_entry_tail *t;
 371
 372         if (!ext4_has_metadata_csum(inode->i_sb))
 373                 return 1;
 374
 375         t = get_dirent_tail(inode, bh);
 376         if (!t) {
 377                 warn_no_space_for_csum(inode);
 378                 return 0;
 379         }
 380
 381         if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data,
 382                                                   (char *)t - bh->b_data))
 383                 return 0;
 384
 385         return 1;
 386 }
 387
 388 static void ext4_dirblock_csum_set(struct inode *inode,
 389                                  struct buffer_head *bh)
 390 {
 391         struct ext4_dir_entry_tail *t;
 392
 393         if (!ext4_has_metadata_csum(inode->i_sb))
 394                 return;
 395
 396         t = get_dirent_tail(inode, bh);
 397         if (!t) {
 398                 warn_no_space_for_csum(inode);
 399                 return;
 400         }
 401
 402         t->det_checksum = ext4_dirblock_csum(inode, bh->b_data,
 403                                              (char *)t - bh->b_data);
 404 }
 405
 406 int ext4_handle_dirty_dirblock(handle_t *handle,
 407                                struct inode *inode,
 408                                struct buffer_head *bh)
 409 {
 410         ext4_dirblock_csum_set(inode, bh);
 411         return ext4_handle_dirty_metadata(handle, inode, bh);
 412 }
 413
 414 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 415                                                struct ext4_dir_entry *dirent,
 416                                                int *offset)
 417 {
 418         struct ext4_dir_entry *dp;
 419         struct dx_root_info *root;
 420         int count_offset;
 421
 422         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 423                 count_offset = 8;
 424         else if (le16_to_cpu(dirent->rec_len) == 12) {
 425                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 426                 if (le16_to_cpu(dp->rec_len) !=
 427                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 428                         return NULL;
 429                 root = (struct dx_root_info *)(((void *)dp + 12));
 430                 if (root->reserved_zero ||
 431                     root->info_length != sizeof(struct dx_root_info))
 432                         return NULL;
 433                 count_offset = 32;
 434         } else
 435                 return NULL;
 436
 437         if (offset)
 438                 *offset = count_offset;
 439         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 440 }
 441
 442 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 443                            int count_offset, int count, struct dx_tail *t)
 444 {
 445         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 446         struct ext4_inode_info *ei = EXT4_I(inode);
 447         __u32 csum;
 448         int size;
 449         __u32 dummy_csum = 0;
 450         int offset = offsetof(struct dx_tail, dt_checksum);
 451
 452         size = count_offset + (count * sizeof(struct dx_entry));
 453         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 454         csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
 455         csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
 456
 457         return cpu_to_le32(csum);
 458 }
 459
 460 static int ext4_dx_csum_verify(struct inode *inode,
 461                                struct ext4_dir_entry *dirent)
 462 {
 463         struct dx_countlimit *c;
 464         struct dx_tail *t;
 465         int count_offset, limit, count;
 466
 467         if (!ext4_has_metadata_csum(inode->i_sb))
 468                 return 1;
 469
 470         c = get_dx_countlimit(inode, dirent, &count_offset);
 471         if (!c) {
 472                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 473                 return 0;
 474         }
 475         limit = le16_to_cpu(c->limit);
 476         count = le16_to_cpu(c->count);
 477         if (count_offset + (limit * sizeof(struct dx_entry)) >
 478             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 479                 warn_no_space_for_csum(inode);
 480                 return 0;
 481         }
 482         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 483
 484         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 485                                             count, t))
 486                 return 0;
 487         return 1;
 488 }
 489
 490 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 491 {
 492         struct dx_countlimit *c;
 493         struct dx_tail *t;
 494         int count_offset, limit, count;
 495
 496         if (!ext4_has_metadata_csum(inode->i_sb))
 497                 return;
 498
 499         c = get_dx_countlimit(inode, dirent, &count_offset);
 500         if (!c) {
 501                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 502                 return;
 503         }
 504         limit = le16_to_cpu(c->limit);
 505         count = le16_to_cpu(c->count);
 506         if (count_offset + (limit * sizeof(struct dx_entry)) >
 507             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 508                 warn_no_space_for_csum(inode);
 509                 return;
 510         }
 511         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 512
 513         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 514 }
 515
 516 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 517                                             struct inode *inode,
 518                                             struct buffer_head *bh)
 519 {
 520         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 521         return ext4_handle_dirty_metadata(handle, inode, bh);
 522 }
 523
 524 /*
 525  * p is at least 6 bytes before the end of page
 526  */
 527 static inline struct ext4_dir_entry_2 *
 528 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 529 {
 530         return (struct ext4_dir_entry_2 *)((char *)p +
 531                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 532 }
 533
 534 /*
 535  * Future: use high four bits of block for coalesce-on-delete flags
 536  * Mask them off for now.
 537  */
 538
 539 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 540 {
 541         return le32_to_cpu(entry->block) & 0x0fffffff;
 542 }
 543
 544 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 545 {
 546         entry->block = cpu_to_le32(value);
 547 }
 548
 549 static inline unsigned dx_get_hash(struct dx_entry *entry)
 550 {
 551         return le32_to_cpu(entry->hash);
 552 }
 553
 554 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 555 {
 556         entry->hash = cpu_to_le32(value);
 557 }
 558
 559 static inline unsigned dx_get_count(struct dx_entry *entries)
 560 {
 561         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 562 }
 563
 564 static inline unsigned dx_get_limit(struct dx_entry *entries)
 565 {
 566         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 567 }
 568
 569 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 570 {
 571         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 572 }
 573
 574 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 575 {
 576         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 577 }
 578
 579 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 580 {
 581         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 582                 EXT4_DIR_REC_LEN(2) - infosize;
 583
 584         if (ext4_has_metadata_csum(dir->i_sb))
 585                 entry_space -= sizeof(struct dx_tail);
 586         return entry_space / sizeof(struct dx_entry);
 587 }
 588
 589 static inline unsigned dx_node_limit(struct inode *dir)
 590 {
 591         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 592
 593         if (ext4_has_metadata_csum(dir->i_sb))
 594                 entry_space -= sizeof(struct dx_tail);
 595         return entry_space / sizeof(struct dx_entry);
 596 }
 597
 598 /*
 599  * Debug
 600  */
 601 #ifdef DX_DEBUG
 602 static void dx_show_index(char * label, struct dx_entry *entries)
 603 {
 604         int i, n = dx_get_count (entries);
 605         printk(KERN_DEBUG "%s index", label);
 606         for (i = 0; i < n; i++) {
 607                 printk(KERN_CONT " %x->%lu",
 608                        i ? dx_get_hash(entries + i) : 0,
 609                        (unsigned long)dx_get_block(entries + i));
 610         }
 611         printk(KERN_CONT "\n");
 612 }
 613
 614 struct stats
 615 {
 616         unsigned names;
 617         unsigned space;
 618         unsigned bcount;
 619 };
 620
 621 static struct stats dx_show_leaf(struct inode *dir,
 622                                 struct dx_hash_info *hinfo,
 623                                 struct ext4_dir_entry_2 *de,
 624                                 int size, int show_names)
 625 {
 626         unsigned names = 0, space = 0;
 627         char *base = (char *) de;
 628         struct dx_hash_info h = *hinfo;
 629
 630         printk("names: ");
 631         while ((char *) de < base + size)
 632         {
 633                 if (de->inode)
 634                 {
 635                         if (show_names)
 636                         {
 637 #ifdef CONFIG_FS_ENCRYPTION
 638                                 int len;
 639                                 char *name;
 640                                 struct fscrypt_str fname_crypto_str =
 641                                         FSTR_INIT(NULL, 0);
 642                                 int res = 0;
 643
 644                                 name  = de->name;
 645                                 len = de->name_len;
 646                                 if (IS_ENCRYPTED(dir))
 647                                         res = fscrypt_get_encryption_info(dir);
 648                                 if (res) {
 649                                         printk(KERN_WARNING "Error setting up"
 650                                                " fname crypto: %d\n", res);
 651                                 }
 652                                 if (!fscrypt_has_encryption_key(dir)) {
 653                                         /* Directory is not encrypted */
 654                                         ext4fs_dirhash(dir, de->name,
 655                                                 de->name_len, &h);
 656                                         printk("%*.s:(U)%x.%u ", len,
 657                                                name, h.hash,
 658                                                (unsigned) ((char *) de
 659                                                            - base));
 660                                 } else {
 661                                         struct fscrypt_str de_name =
 662                                                 FSTR_INIT(name, len);
 663
 664                                         /* Directory is encrypted */
 665                                         res = fscrypt_fname_alloc_buffer(
 666                                                 dir, len,
 667                                                 &fname_crypto_str);
 668                                         if (res)
 669                                                 printk(KERN_WARNING "Error "
 670                                                         "allocating crypto "
 671                                                         "buffer--skipping "
 672                                                         "crypto\n");
 673                                         res = fscrypt_fname_disk_to_usr(dir,
 674                                                 0, 0, &de_name,
 675                                                 &fname_crypto_str);
 676                                         if (res) {
 677                                                 printk(KERN_WARNING "Error "
 678                                                         "converting filename "
 679                                                         "from disk to usr"
 680                                                         "\n");
 681                                                 name = "??";
 682                                                 len = 2;
 683                                         } else {
 684                                                 name = fname_crypto_str.name;
 685                                                 len = fname_crypto_str.len;
 686                                         }
 687                                         ext4fs_dirhash(dir, de->name,
 688                                                        de->name_len, &h);
 689                                         printk("%*.s:(E)%x.%u ", len, name,
 690                                                h.hash, (unsigned) ((char *) de
 691                                                                    - base));
 692                                         fscrypt_fname_free_buffer(
 693                                                         &fname_crypto_str);
 694                                 }
 695 #else
 696                                 int len = de->name_len;
 697                                 char *name = de->name;
 698                                 ext4fs_dirhash(dir, de->name, de->name_len, &h);
 699                                 printk("%*.s:%x.%u ", len, name, h.hash,
 700                                        (unsigned) ((char *) de - base));
 701 #endif
 702                         }
 703                         space += EXT4_DIR_REC_LEN(de->name_len);
 704                         names++;
 705                 }
 706                 de = ext4_next_entry(de, size);
 707         }
 708         printk(KERN_CONT "(%i)\n", names);
 709         return (struct stats) { names, space, 1 };
 710 }
 711
 712 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 713                              struct dx_entry *entries, int levels)
 714 {
 715         unsigned blocksize = dir->i_sb->s_blocksize;
 716         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 717         unsigned bcount = 0;
 718         struct buffer_head *bh;
 719         printk("%i indexed blocks...\n", count);
 720         for (i = 0; i < count; i++, entries++)
 721         {
 722                 ext4_lblk_t block = dx_get_block(entries);
 723                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 724                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 725                 struct stats stats;
 726                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 727                 bh = ext4_bread(NULL,dir, block, 0);
 728                 if (!bh || IS_ERR(bh))
 729                         continue;
 730                 stats = levels?
 731                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 732                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 733                         bh->b_data, blocksize, 0);
 734                 names += stats.names;
 735                 space += stats.space;
 736                 bcount += stats.bcount;
 737                 brelse(bh);
 738         }
 739         if (bcount)
 740                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 741                        levels ? "" : "   ", names, space/bcount,
 742                        (space/bcount)*100/blocksize);
 743         return (struct stats) { names, space, bcount};
 744 }
 745 #endif /* DX_DEBUG */
 746
 747 /*
 748  * Probe for a directory leaf block to search.
 749  *
 750  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 751  * error in the directory index, and the caller should fall back to
 752  * searching the directory normally.  The callers of dx_probe **MUST**
 753  * check for this error code, and make sure it never gets reflected
 754  * back to userspace.
 755  */
 756 static struct dx_frame *
 757 dx_probe(struct ext4_filename *fname, struct inode *dir,
 758          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 759 {
 760         unsigned count, indirect;
 761         struct dx_entry *at, *entries, *p, *q, *m;
 762         struct dx_root *root;
 763         struct dx_frame *frame = frame_in;
 764         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 765         u32 hash;
 766
 767         memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
 768         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 769         if (IS_ERR(frame->bh))
 770                 return (struct dx_frame *) frame->bh;
 771
 772         root = (struct dx_root *) frame->bh->b_data;
 773         if (root->info.hash_version != DX_HASH_TEA &&
 774             root->info.hash_version != DX_HASH_HALF_MD4 &&
 775             root->info.hash_version != DX_HASH_LEGACY) {
 776                 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
 777                                    root->info.hash_version);
 778                 goto fail;
 779         }
 780         if (fname)
 781                 hinfo = &fname->hinfo;
 782         hinfo->hash_version = root->info.hash_version;
 783         if (hinfo->hash_version <= DX_HASH_TEA)
 784                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 785         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 786         if (fname && fname_name(fname))
 787                 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
 788         hash = hinfo->hash;
 789
 790         if (root->info.unused_flags & 1) {
 791                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
 792                                    root->info.unused_flags);
 793                 goto fail;
 794         }
 795
 796         indirect = root->info.indirect_levels;
 797         if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
 798                 ext4_warning(dir->i_sb,
 799                              "Directory (ino: %lu) htree depth %#06x exceed"
 800                              "supported value", dir->i_ino,
 801                              ext4_dir_htree_level(dir->i_sb));
 802                 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
 803                         ext4_warning(dir->i_sb, "Enable large directory "
 804                                                 "feature to access it");
 805                 }
 806                 goto fail;
 807         }
 808
 809         entries = (struct dx_entry *)(((char *)&root->info) +
 810                                       root->info.info_length);
 811
 812         if (dx_get_limit(entries) != dx_root_limit(dir,
 813                                                    root->info.info_length)) {
 814                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 815                                    dx_get_limit(entries),
 816                                    dx_root_limit(dir, root->info.info_length));
 817                 goto fail;
 818         }
 819
 820         dxtrace(printk("Look up %x", hash));
 821         while (1) {
 822                 count = dx_get_count(entries);
 823                 if (!count || count > dx_get_limit(entries)) {
 824                         ext4_warning_inode(dir,
 825                                            "dx entry: count %u beyond limit %u",
 826                                            count, dx_get_limit(entries));
 827                         goto fail;
 828                 }
 829
 830                 p = entries + 1;
 831                 q = entries + count - 1;
 832                 while (p <= q) {
 833                         m = p + (q - p) / 2;
 834                         dxtrace(printk(KERN_CONT "."));
 835                         if (dx_get_hash(m) > hash)
 836                                 q = m - 1;
 837                         else
 838                                 p = m + 1;
 839                 }
 840
 841                 if (0) { // linear search cross check
 842                         unsigned n = count - 1;
 843                         at = entries;
 844                         while (n--)
 845                         {
 846                                 dxtrace(printk(KERN_CONT ","));
 847                                 if (dx_get_hash(++at) > hash)
 848                                 {
 849                                         at--;
 850                                         break;
 851                                 }
 852                         }
 853                         assert (at == p - 1);
 854                 }
 855
 856                 at = p - 1;
 857                 dxtrace(printk(KERN_CONT " %x->%u\n",
 858                                at == entries ? 0 : dx_get_hash(at),
 859                                dx_get_block(at)));
 860                 frame->entries = entries;
 861                 frame->at = at;
 862                 if (!indirect--)
 863                         return frame;
 864                 frame++;
 865                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 866                 if (IS_ERR(frame->bh)) {
 867                         ret_err = (struct dx_frame *) frame->bh;
 868                         frame->bh = NULL;
 869                         goto fail;
 870                 }
 871                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 872
 873                 if (dx_get_limit(entries) != dx_node_limit(dir)) {
 874                         ext4_warning_inode(dir,
 875                                 "dx entry: limit %u != node limit %u",
 876                                 dx_get_limit(entries), dx_node_limit(dir));
 877                         goto fail;
 878                 }
 879         }
 880 fail:
 881         while (frame >= frame_in) {
 882                 brelse(frame->bh);
 883                 frame--;
 884         }
 885
 886         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 887                 ext4_warning_inode(dir,
 888                         "Corrupt directory, running e2fsck is recommended");
 889         return ret_err;
 890 }
 891
 892 static void dx_release(struct dx_frame *frames)
 893 {
 894         struct dx_root_info *info;
 895         int i;
 896         unsigned int indirect_levels;
 897
 898         if (frames[0].bh == NULL)
 899                 return;
 900
 901         info = &((struct dx_root *)frames[0].bh->b_data)->info;
 902         /* save local copy, "info" may be freed after brelse() */
 903         indirect_levels = info->indirect_levels;
 904         for (i = 0; i <= indirect_levels; i++) {
 905                 if (frames[i].bh == NULL)
 906                         break;
 907                 brelse(frames[i].bh);
 908                 frames[i].bh = NULL;
 909         }
 910 }
 911
 912 /*
 913  * This function increments the frame pointer to search the next leaf
 914  * block, and reads in the necessary intervening nodes if the search
 915  * should be necessary.  Whether or not the search is necessary is
 916  * controlled by the hash parameter.  If the hash value is even, then
 917  * the search is only continued if the next block starts with that
 918  * hash value.  This is used if we are searching for a specific file.
 919  *
 920  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 921  *
 922  * This function returns 1 if the caller should continue to search,
 923  * or 0 if it should not.  If there is an error reading one of the
 924  * index blocks, it will a negative error code.
 925  *
 926  * If start_hash is non-null, it will be filled in with the starting
 927  * hash of the next page.
 928  */
 929 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 930                                  struct dx_frame *frame,
 931                                  struct dx_frame *frames,
 932                                  __u32 *start_hash)
 933 {
 934         struct dx_frame *p;
 935         struct buffer_head *bh;
 936         int num_frames = 0;
 937         __u32 bhash;
 938
 939         p = frame;
 940         /*
 941          * Find the next leaf page by incrementing the frame pointer.
 942          * If we run out of entries in the interior node, loop around and
 943          * increment pointer in the parent node.  When we break out of
 944          * this loop, num_frames indicates the number of interior
 945          * nodes need to be read.
 946          */
 947         while (1) {
 948                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 949                         break;
 950                 if (p == frames)
 951                         return 0;
 952                 num_frames++;
 953                 p--;
 954         }
 955
 956         /*
 957          * If the hash is 1, then continue only if the next page has a
 958          * continuation hash of any value.  This is used for readdir
 959          * handling.  Otherwise, check to see if the hash matches the
 960          * desired contiuation hash.  If it doesn't, return since
 961          * there's no point to read in the successive index pages.
 962          */
 963         bhash = dx_get_hash(p->at);
 964         if (start_hash)
 965                 *start_hash = bhash;
 966         if ((hash & 1) == 0) {
 967                 if ((bhash & ~1) != hash)
 968                         return 0;
 969         }
 970         /*
 971          * If the hash is HASH_NB_ALWAYS, we always go to the next
 972          * block so no check is necessary
 973          */
 974         while (num_frames--) {
 975                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 976                 if (IS_ERR(bh))
 977                         return PTR_ERR(bh);
 978                 p++;
 979                 brelse(p->bh);
 980                 p->bh = bh;
 981                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 982         }
 983         return 1;
 984 }
 985
 986
 987 /*
 988  * This function fills a red-black tree with information from a
 989  * directory block.  It returns the number directory entries loaded
 990  * into the tree.  If there is an error it is returned in err.
 991  */
 992 static int htree_dirblock_to_tree(struct file *dir_file,
 993                                   struct inode *dir, ext4_lblk_t block,
 994                                   struct dx_hash_info *hinfo,
 995                                   __u32 start_hash, __u32 start_minor_hash)
 996 {
 997         struct buffer_head *bh;
 998         struct ext4_dir_entry_2 *de, *top;
 999         int err = 0, count = 0;
1000         struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
1001
1002         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
1003                                                         (unsigned long)block));
1004         bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1005         if (IS_ERR(bh))
1006                 return PTR_ERR(bh);
1007
1008         de = (struct ext4_dir_entry_2 *) bh->b_data;
1009         top = (struct ext4_dir_entry_2 *) ((char *) de +
1010                                            dir->i_sb->s_blocksize -
1011                                            EXT4_DIR_REC_LEN(0));
1012         /* Check if the directory is encrypted */
1013         if (IS_ENCRYPTED(dir)) {
1014                 err = fscrypt_get_encryption_info(dir);
1015                 if (err < 0) {
1016                         brelse(bh);
1017                         return err;
1018                 }
1019                 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
1020                                                      &fname_crypto_str);
1021                 if (err < 0) {
1022                         brelse(bh);
1023                         return err;
1024                 }
1025         }
1026
1027         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1028                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1029                                 bh->b_data, bh->b_size,
1030                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1031                                          + ((char *)de - bh->b_data))) {
1032                         /* silently ignore the rest of the block */
1033                         break;
1034                 }
1035                 ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
1036                 if ((hinfo->hash < start_hash) ||
1037                     ((hinfo->hash == start_hash) &&
1038                      (hinfo->minor_hash < start_minor_hash)))
1039                         continue;
1040                 if (de->inode == 0)
1041                         continue;
1042                 if (!IS_ENCRYPTED(dir)) {
1043                         tmp_str.name = de->name;
1044                         tmp_str.len = de->name_len;
1045                         err = ext4_htree_store_dirent(dir_file,
1046                                    hinfo->hash, hinfo->minor_hash, de,
1047                                    &tmp_str);
1048                 } else {
1049                         int save_len = fname_crypto_str.len;
1050                         struct fscrypt_str de_name = FSTR_INIT(de->name,
1051                                                                 de->name_len);
1052
1053                         /* Directory is encrypted */
1054                         err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1055                                         hinfo->minor_hash, &de_name,
1056                                         &fname_crypto_str);
1057                         if (err) {
1058                                 count = err;
1059                                 goto errout;
1060                         }
1061                         err = ext4_htree_store_dirent(dir_file,
1062                                    hinfo->hash, hinfo->minor_hash, de,
1063                                         &fname_crypto_str);
1064                         fname_crypto_str.len = save_len;
1065                 }
1066                 if (err != 0) {
1067                         count = err;
1068                         goto errout;
1069                 }
1070                 count++;
1071         }
1072 errout:
1073         brelse(bh);
1074         fscrypt_fname_free_buffer(&fname_crypto_str);
1075         return count;
1076 }
1077
1078
1079 /*
1080  * This function fills a red-black tree with information from a
1081  * directory.  We start scanning the directory in hash order, starting
1082  * at start_hash and start_minor_hash.
1083  *
1084  * This function returns the number of entries inserted into the tree,
1085  * or a negative error code.
1086  */
1087 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1088                          __u32 start_minor_hash, __u32 *next_hash)
1089 {
1090         struct dx_hash_info hinfo;
1091         struct ext4_dir_entry_2 *de;
1092         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1093         struct inode *dir;
1094         ext4_lblk_t block;
1095         int count = 0;
1096         int ret, err;
1097         __u32 hashval;
1098         struct fscrypt_str tmp_str;
1099
1100         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1101                        start_hash, start_minor_hash));
1102         dir = file_inode(dir_file);
1103         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1104                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1105                 if (hinfo.hash_version <= DX_HASH_TEA)
1106                         hinfo.hash_version +=
1107                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1108                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1109                 if (ext4_has_inline_data(dir)) {
1110                         int has_inline_data = 1;
1111                         count = ext4_inlinedir_to_tree(dir_file, dir, 0,
1112                                                        &hinfo, start_hash,
1113                                                        start_minor_hash,
1114                                                        &has_inline_data);
1115                         if (has_inline_data) {
1116                                 *next_hash = ~0;
1117                                 return count;
1118                         }
1119                 }
1120                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1121                                                start_hash, start_minor_hash);
1122                 *next_hash = ~0;
1123                 return count;
1124         }
1125         hinfo.hash = start_hash;
1126         hinfo.minor_hash = 0;
1127         frame = dx_probe(NULL, dir, &hinfo, frames);
1128         if (IS_ERR(frame))
1129                 return PTR_ERR(frame);
1130
1131         /* Add '.' and '..' from the htree header */
1132         if (!start_hash && !start_minor_hash) {
1133                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1134                 tmp_str.name = de->name;
1135                 tmp_str.len = de->name_len;
1136                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1137                                               de, &tmp_str);
1138                 if (err != 0)
1139                         goto errout;
1140                 count++;
1141         }
1142         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1143                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1144                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1145                 tmp_str.name = de->name;
1146                 tmp_str.len = de->name_len;
1147                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1148                                               de, &tmp_str);
1149                 if (err != 0)
1150                         goto errout;
1151                 count++;
1152         }
1153
1154         while (1) {
1155                 if (fatal_signal_pending(current)) {
1156                         err = -ERESTARTSYS;
1157                         goto errout;
1158                 }
1159                 cond_resched();
1160                 block = dx_get_block(frame->at);
1161                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1162                                              start_hash, start_minor_hash);
1163                 if (ret < 0) {
1164                         err = ret;
1165                         goto errout;
1166                 }
1167                 count += ret;
1168                 hashval = ~0;
1169                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1170                                             frame, frames, &hashval);
1171                 *next_hash = hashval;
1172                 if (ret < 0) {
1173                         err = ret;
1174                         goto errout;
1175                 }
1176                 /*
1177                  * Stop if:  (a) there are no more entries, or
1178                  * (b) we have inserted at least one entry and the
1179                  * next hash value is not a continuation
1180                  */
1181                 if ((ret == 0) ||
1182                     (count && ((hashval & 1) == 0)))
1183                         break;
1184         }
1185         dx_release(frames);
1186         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1187                        "next hash: %x\n", count, *next_hash));
1188         return count;
1189 errout:
1190         dx_release(frames);
1191         return (err);
1192 }
1193
1194 static inline int search_dirblock(struct buffer_head *bh,
1195                                   struct inode *dir,
1196                                   struct ext4_filename *fname,
1197                                   unsigned int offset,
1198                                   struct ext4_dir_entry_2 **res_dir)
1199 {
1200         return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1201                                fname, offset, res_dir);
1202 }
1203
1204 /*
1205  * Directory block splitting, compacting
1206  */
1207
1208 /*
1209  * Create map of hash values, offsets, and sizes, stored at end of block.
1210  * Returns number of entries mapped.
1211  */
1212 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1213                        unsigned blocksize, struct dx_hash_info *hinfo,
1214                        struct dx_map_entry *map_tail)
1215 {
1216         int count = 0;
1217         char *base = (char *) de;
1218         struct dx_hash_info h = *hinfo;
1219
1220         while ((char *) de < base + blocksize) {
1221                 if (de->name_len && de->inode) {
1222                         ext4fs_dirhash(dir, de->name, de->name_len, &h);
1223                         map_tail--;
1224                         map_tail->hash = h.hash;
1225                         map_tail->offs = ((char *) de - base)>>2;
1226                         map_tail->size = le16_to_cpu(de->rec_len);
1227                         count++;
1228                         cond_resched();
1229                 }
1230                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1231                 de = ext4_next_entry(de, blocksize);
1232         }
1233         return count;
1234 }
1235
1236 /* Sort map by hash value */
1237 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1238 {
1239         struct dx_map_entry *p, *q, *top = map + count - 1;
1240         int more;
1241         /* Combsort until bubble sort doesn't suck */
1242         while (count > 2) {
1243                 count = count*10/13;
1244                 if (count - 9 < 2) /* 9, 10 -> 11 */
1245                         count = 11;
1246                 for (p = top, q = p - count; q >= map; p--, q--)
1247                         if (p->hash < q->hash)
1248                                 swap(*p, *q);
1249         }
1250         /* Garden variety bubble sort */
1251         do {
1252                 more = 0;
1253                 q = top;
1254                 while (q-- > map) {
1255                         if (q[1].hash >= q[0].hash)
1256                                 continue;
1257                         swap(*(q+1), *q);
1258                         more = 1;
1259                 }
1260         } while(more);
1261 }
1262
1263 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1264 {
1265         struct dx_entry *entries = frame->entries;
1266         struct dx_entry *old = frame->at, *new = old + 1;
1267         int count = dx_get_count(entries);
1268
1269         assert(count < dx_get_limit(entries));
1270         assert(old < entries + count);
1271         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1272         dx_set_hash(new, hash);
1273         dx_set_block(new, block);
1274         dx_set_count(entries, count + 1);
1275 }
1276
1277 #ifdef CONFIG_UNICODE
1278 /*
1279  * Test whether a case-insensitive directory entry matches the filename
1280  * being searched for.  If quick is set, assume the name being looked up
1281  * is already in the casefolded form.
1282  *
1283  * Returns: 0 if the directory entry matches, more than 0 if it
1284  * doesn't match or less than zero on error.
1285  */
1286 int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
1287                     const struct qstr *entry, bool quick)
1288 {
1289         const struct ext4_sb_info *sbi = EXT4_SB(parent->i_sb);
1290         const struct unicode_map *um = sbi->s_encoding;
1291         int ret;
1292
1293         if (quick)
1294                 ret = utf8_strncasecmp_folded(um, name, entry);
1295         else
1296                 ret = utf8_strncasecmp(um, name, entry);
1297
1298         if (ret < 0) {
1299                 /* Handle invalid character sequence as either an error
1300                  * or as an opaque byte sequence.
1301                  */
1302                 if (ext4_has_strict_mode(sbi))
1303                         return -EINVAL;
1304
1305                 if (name->len != entry->len)
1306                         return 1;
1307
1308                 return !!memcmp(name->name, entry->name, name->len);
1309         }
1310
1311         return ret;
1312 }
1313
1314 void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
1315                                   struct fscrypt_str *cf_name)
1316 {
1317         int len;
1318
1319         if (!IS_CASEFOLDED(dir) || !EXT4_SB(dir->i_sb)->s_encoding) {
1320                 cf_name->name = NULL;
1321                 return;
1322         }
1323
1324         cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
1325         if (!cf_name->name)
1326                 return;
1327
1328         len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding,
1329                             iname, cf_name->name,
1330                             EXT4_NAME_LEN);
1331         if (len <= 0) {
1332                 kfree(cf_name->name);
1333                 cf_name->name = NULL;
1334                 return;
1335         }
1336         cf_name->len = (unsigned) len;
1337
1338 }
1339 #endif
1340
1341 /*
1342  * Test whether a directory entry matches the filename being searched for.
1343  *
1344  * Return: %true if the directory entry matches, otherwise %false.
1345  */
1346 static inline bool ext4_match(const struct inode *parent,
1347                               const struct ext4_filename *fname,
1348                               const struct ext4_dir_entry_2 *de)
1349 {
1350         struct fscrypt_name f;
1351 #ifdef CONFIG_UNICODE
1352         const struct qstr entry = {.name = de->name, .len = de->name_len};
1353 #endif
1354
1355         if (!de->inode)
1356                 return false;
1357
1358         f.usr_fname = fname->usr_fname;
1359         f.disk_name = fname->disk_name;
1360 #ifdef CONFIG_FS_ENCRYPTION
1361         f.crypto_buf = fname->crypto_buf;
1362 #endif
1363
1364 #ifdef CONFIG_UNICODE
1365         if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent)) {
1366                 if (fname->cf_name.name) {
1367                         struct qstr cf = {.name = fname->cf_name.name,
1368                                           .len = fname->cf_name.len};
1369                         return !ext4_ci_compare(parent, &cf, &entry, true);
1370                 }
1371                 return !ext4_ci_compare(parent, fname->usr_fname, &entry,
1372                                         false);
1373         }
1374 #endif
1375
1376         return fscrypt_match_name(&f, de->name, de->name_len);
1377 }
1378
1379 /*
1380  * Returns 0 if not found, -1 on failure, and 1 on success
1381  */
1382 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1383                     struct inode *dir, struct ext4_filename *fname,
1384                     unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1385 {
1386         struct ext4_dir_entry_2 * de;
1387         char * dlimit;
1388         int de_len;
1389
1390         de = (struct ext4_dir_entry_2 *)search_buf;
1391         dlimit = search_buf + buf_size;
1392         while ((char *) de < dlimit) {
1393                 /* this code is executed quadratically often */
1394                 /* do minimal checking `by hand' */
1395                 if ((char *) de + de->name_len <= dlimit &&
1396                     ext4_match(dir, fname, de)) {
1397                         /* found a match - just to be sure, do
1398                          * a full check */
1399                         if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1400                                                  bh->b_size, offset))
1401                                 return -1;
1402                         *res_dir = de;
1403                         return 1;
1404                 }
1405                 /* prevent looping on a bad block */
1406                 de_len = ext4_rec_len_from_disk(de->rec_len,
1407                                                 dir->i_sb->s_blocksize);
1408                 if (de_len <= 0)
1409                         return -1;
1410                 offset += de_len;
1411                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1412         }
1413         return 0;
1414 }
1415
1416 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1417                                struct ext4_dir_entry *de)
1418 {
1419         struct super_block *sb = dir->i_sb;
1420
1421         if (!is_dx(dir))
1422                 return 0;
1423         if (block == 0)
1424                 return 1;
1425         if (de->inode == 0 &&
1426             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1427                         sb->s_blocksize)
1428                 return 1;
1429         return 0;
1430 }
1431
1432 /*
1433  *      __ext4_find_entry()
1434  *
1435  * finds an entry in the specified directory with the wanted name. It
1436  * returns the cache buffer in which the entry was found, and the entry
1437  * itself (as a parameter - res_dir). It does NOT read the inode of the
1438  * entry - you'll have to do that yourself if you want to.
1439  *
1440  * The returned buffer_head has ->b_count elevated.  The caller is expected
1441  * to brelse() it when appropriate.
1442  */
1443 static struct buffer_head *__ext4_find_entry(struct inode *dir,
1444                                              struct ext4_filename *fname,
1445                                              struct ext4_dir_entry_2 **res_dir,
1446                                              int *inlined)
1447 {
1448         struct super_block *sb;
1449         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1450         struct buffer_head *bh, *ret = NULL;
1451         ext4_lblk_t start, block;
1452         const u8 *name = fname->usr_fname->name;
1453         size_t ra_max = 0;      /* Number of bh's in the readahead
1454                                    buffer, bh_use[] */
1455         size_t ra_ptr = 0;      /* Current index into readahead
1456                                    buffer */
1457         ext4_lblk_t  nblocks;
1458         int i, namelen, retval;
1459
1460         *res_dir = NULL;
1461         sb = dir->i_sb;
1462         namelen = fname->usr_fname->len;
1463         if (namelen > EXT4_NAME_LEN)
1464                 return NULL;
1465
1466         if (ext4_has_inline_data(dir)) {
1467                 int has_inline_data = 1;
1468                 ret = ext4_find_inline_entry(dir, fname, res_dir,
1469                                              &has_inline_data);
1470                 if (has_inline_data) {
1471                         if (inlined)
1472                                 *inlined = 1;
1473                         goto cleanup_and_exit;
1474                 }
1475         }
1476
1477         if ((namelen <= 2) && (name[0] == '.') &&
1478             (name[1] == '.' || name[1] == '\0')) {
1479                 /*
1480                  * "." or ".." will only be in the first block
1481                  * NFS may look up ".."; "." should be handled by the VFS
1482                  */
1483                 block = start = 0;
1484                 nblocks = 1;
1485                 goto restart;
1486         }
1487         if (is_dx(dir)) {
1488                 ret = ext4_dx_find_entry(dir, fname, res_dir);
1489                 /*
1490                  * On success, or if the error was file not found,
1491                  * return.  Otherwise, fall back to doing a search the
1492                  * old fashioned way.
1493                  */
1494                 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1495                         goto cleanup_and_exit;
1496                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1497                                "falling back\n"));
1498                 ret = NULL;
1499         }
1500         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1501         if (!nblocks) {
1502                 ret = NULL;
1503                 goto cleanup_and_exit;
1504         }
1505         start = EXT4_I(dir)->i_dir_start_lookup;
1506         if (start >= nblocks)
1507                 start = 0;
1508         block = start;
1509 restart:
1510         do {
1511                 /*
1512                  * We deal with the read-ahead logic here.
1513                  */
1514                 cond_resched();
1515                 if (ra_ptr >= ra_max) {
1516                         /* Refill the readahead buffer */
1517                         ra_ptr = 0;
1518                         if (block < start)
1519                                 ra_max = start - block;
1520                         else
1521                                 ra_max = nblocks - block;
1522                         ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1523                         retval = ext4_bread_batch(dir, block, ra_max,
1524                                                   false /* wait */, bh_use);
1525                         if (retval) {
1526                                 ret = ERR_PTR(retval);
1527                                 ra_max = 0;
1528                                 goto cleanup_and_exit;
1529                         }
1530                 }
1531                 if ((bh = bh_use[ra_ptr++]) == NULL)
1532                         goto next;
1533                 wait_on_buffer(bh);
1534                 if (!buffer_uptodate(bh)) {
1535                         EXT4_ERROR_INODE_ERR(dir, EIO,
1536                                              "reading directory lblock %lu",
1537                                              (unsigned long) block);
1538                         brelse(bh);
1539                         ret = ERR_PTR(-EIO);
1540                         goto cleanup_and_exit;
1541                 }
1542                 if (!buffer_verified(bh) &&
1543                     !is_dx_internal_node(dir, block,
1544                                          (struct ext4_dir_entry *)bh->b_data) &&
1545                     !ext4_dirblock_csum_verify(dir, bh)) {
1546                         EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
1547                                              "checksumming directory "
1548                                              "block %lu", (unsigned long)block);
1549                         brelse(bh);
1550                         ret = ERR_PTR(-EFSBADCRC);
1551                         goto cleanup_and_exit;
1552                 }
1553                 set_buffer_verified(bh);
1554                 i = search_dirblock(bh, dir, fname,
1555                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1556                 if (i == 1) {
1557                         EXT4_I(dir)->i_dir_start_lookup = block;
1558                         ret = bh;
1559                         goto cleanup_and_exit;
1560                 } else {
1561                         brelse(bh);
1562                         if (i < 0)
1563                                 goto cleanup_and_exit;
1564                 }
1565         next:
1566                 if (++block >= nblocks)
1567                         block = 0;
1568         } while (block != start);
1569
1570         /*
1571          * If the directory has grown while we were searching, then
1572          * search the last part of the directory before giving up.
1573          */
1574         block = nblocks;
1575         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1576         if (block < nblocks) {
1577                 start = 0;
1578                 goto restart;
1579         }
1580
1581 cleanup_and_exit:
1582         /* Clean up the read-ahead blocks */
1583         for (; ra_ptr < ra_max; ra_ptr++)
1584                 brelse(bh_use[ra_ptr]);
1585         return ret;
1586 }
1587
1588 static struct buffer_head *ext4_find_entry(struct inode *dir,
1589                                            const struct qstr *d_name,
1590                                            struct ext4_dir_entry_2 **res_dir,
1591                                            int *inlined)
1592 {
1593         int err;
1594         struct ext4_filename fname;
1595         struct buffer_head *bh;
1596
1597         err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1598         if (err == -ENOENT)
1599                 return NULL;
1600         if (err)
1601                 return ERR_PTR(err);
1602
1603         bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
1604
1605         ext4_fname_free_filename(&fname);
1606         return bh;
1607 }
1608
1609 static struct buffer_head *ext4_lookup_entry(struct inode *dir,
1610                                              struct dentry *dentry,
1611                                              struct ext4_dir_entry_2 **res_dir)
1612 {
1613         int err;
1614         struct ext4_filename fname;
1615         struct buffer_head *bh;
1616
1617         err = ext4_fname_prepare_lookup(dir, dentry, &fname);
1618         if (err == -ENOENT)
1619                 return NULL;
1620         if (err)
1621                 return ERR_PTR(err);
1622
1623         bh = __ext4_find_entry(dir, &fname, res_dir, NULL);
1624
1625         ext4_fname_free_filename(&fname);
1626         return bh;
1627 }
1628
1629 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1630                         struct ext4_filename *fname,
1631                         struct ext4_dir_entry_2 **res_dir)
1632 {
1633         struct super_block * sb = dir->i_sb;
1634         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1635         struct buffer_head *bh;
1636         ext4_lblk_t block;
1637         int retval;
1638
1639 #ifdef CONFIG_FS_ENCRYPTION
1640         *res_dir = NULL;
1641 #endif
1642         frame = dx_probe(fname, dir, NULL, frames);
1643         if (IS_ERR(frame))
1644                 return (struct buffer_head *) frame;
1645         do {
1646                 block = dx_get_block(frame->at);
1647                 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1648                 if (IS_ERR(bh))
1649                         goto errout;
1650
1651                 retval = search_dirblock(bh, dir, fname,
1652                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1653                                          res_dir);
1654                 if (retval == 1)
1655                         goto success;
1656                 brelse(bh);
1657                 if (retval == -1) {
1658                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1659                         goto errout;
1660                 }
1661
1662                 /* Check to see if we should continue to search */
1663                 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1664                                                frames, NULL);
1665                 if (retval < 0) {
1666                         ext4_warning_inode(dir,
1667                                 "error %d reading directory index block",
1668                                 retval);
1669                         bh = ERR_PTR(retval);
1670                         goto errout;
1671                 }
1672         } while (retval == 1);
1673
1674         bh = NULL;
1675 errout:
1676         dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1677 success:
1678         dx_release(frames);
1679         return bh;
1680 }
1681
1682 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1683 {
1684         struct inode *inode;
1685         struct ext4_dir_entry_2 *de;
1686         struct buffer_head *bh;
1687
1688         if (dentry->d_name.len > EXT4_NAME_LEN)
1689                 return ERR_PTR(-ENAMETOOLONG);
1690
1691         bh = ext4_lookup_entry(dir, dentry, &de);
1692         if (IS_ERR(bh))
1693                 return ERR_CAST(bh);
1694         inode = NULL;
1695         if (bh) {
1696                 __u32 ino = le32_to_cpu(de->inode);
1697                 brelse(bh);
1698                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1699                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1700                         return ERR_PTR(-EFSCORRUPTED);
1701                 }
1702                 if (unlikely(ino == dir->i_ino)) {
1703                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1704                                          dentry);
1705                         return ERR_PTR(-EFSCORRUPTED);
1706                 }
1707                 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
1708                 if (inode == ERR_PTR(-ESTALE)) {
1709                         EXT4_ERROR_INODE(dir,
1710                                          "deleted inode referenced: %u",
1711                                          ino);
1712                         return ERR_PTR(-EFSCORRUPTED);
1713                 }
1714                 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) &&
1715                     (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1716                     !fscrypt_has_permitted_context(dir, inode)) {
1717                         ext4_warning(inode->i_sb,
1718                                      "Inconsistent encryption contexts: %lu/%lu",
1719                                      dir->i_ino, inode->i_ino);
1720                         iput(inode);
1721                         return ERR_PTR(-EPERM);
1722                 }
1723         }
1724
1725 #ifdef CONFIG_UNICODE
1726         if (!inode && IS_CASEFOLDED(dir)) {
1727                 /* Eventually we want to call d_add_ci(dentry, NULL)
1728                  * for negative dentries in the encoding case as
1729                  * well.  For now, prevent the negative dentry
1730                  * from being cached.
1731                  */
1732                 return NULL;
1733         }
1734 #endif
1735         return d_splice_alias(inode, dentry);
1736 }
1737
1738
1739 struct dentry *ext4_get_parent(struct dentry *child)
1740 {
1741         __u32 ino;
1742         static const struct qstr dotdot = QSTR_INIT("..", 2);
1743         struct ext4_dir_entry_2 * de;
1744         struct buffer_head *bh;
1745
1746         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1747         if (IS_ERR(bh))
1748                 return ERR_CAST(bh);
1749         if (!bh)
1750                 return ERR_PTR(-ENOENT);
1751         ino = le32_to_cpu(de->inode);
1752         brelse(bh);
1753
1754         if (!ext4_valid_inum(child->d_sb, ino)) {
1755                 EXT4_ERROR_INODE(d_inode(child),
1756                                  "bad parent inode number: %u", ino);
1757                 return ERR_PTR(-EFSCORRUPTED);
1758         }
1759
1760         return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
1761 }
1762
1763 /*
1764  * Move count entries from end of map between two memory locations.
1765  * Returns pointer to last entry moved.
1766  */
1767 static struct ext4_dir_entry_2 *
1768 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1769                 unsigned blocksize)
1770 {
1771         unsigned rec_len = 0;
1772
1773         while (count--) {
1774                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1775                                                 (from + (map->offs<<2));
1776                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1777                 memcpy (to, de, rec_len);
1778                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1779                                 ext4_rec_len_to_disk(rec_len, blocksize);
1780                 de->inode = 0;
1781                 map++;
1782                 to += rec_len;
1783         }
1784         return (struct ext4_dir_entry_2 *) (to - rec_len);
1785 }
1786
1787 /*
1788  * Compact each dir entry in the range to the minimal rec_len.
1789  * Returns pointer to last entry in range.
1790  */
1791 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1792 {
1793         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1794         unsigned rec_len = 0;
1795
1796         prev = to = de;
1797         while ((char*)de < base + blocksize) {
1798                 next = ext4_next_entry(de, blocksize);
1799                 if (de->inode && de->name_len) {
1800                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1801                         if (de > to)
1802                                 memmove(to, de, rec_len);
1803                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1804                         prev = to;
1805                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1806                 }
1807                 de = next;
1808         }
1809         return prev;
1810 }
1811
1812 /*
1813  * Split a full leaf block to make room for a new dir entry.
1814  * Allocate a new block, and move entries so that they are approx. equally full.
1815  * Returns pointer to de in block into which the new entry will be inserted.
1816  */
1817 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1818                         struct buffer_head **bh,struct dx_frame *frame,
1819                         struct dx_hash_info *hinfo)
1820 {
1821         unsigned blocksize = dir->i_sb->s_blocksize;
1822         unsigned count, continued;
1823         struct buffer_head *bh2;
1824         ext4_lblk_t newblock;
1825         u32 hash2;
1826         struct dx_map_entry *map;
1827         char *data1 = (*bh)->b_data, *data2;
1828         unsigned split, move, size;
1829         struct ext4_dir_entry_2 *de = NULL, *de2;
1830         int     csum_size = 0;
1831         int     err = 0, i;
1832
1833         if (ext4_has_metadata_csum(dir->i_sb))
1834                 csum_size = sizeof(struct ext4_dir_entry_tail);
1835
1836         bh2 = ext4_append(handle, dir, &newblock);
1837         if (IS_ERR(bh2)) {
1838                 brelse(*bh);
1839                 *bh = NULL;
1840                 return (struct ext4_dir_entry_2 *) bh2;
1841         }
1842
1843         BUFFER_TRACE(*bh, "get_write_access");
1844         err = ext4_journal_get_write_access(handle, *bh);
1845         if (err)
1846                 goto journal_error;
1847
1848         BUFFER_TRACE(frame->bh, "get_write_access");
1849         err = ext4_journal_get_write_access(handle, frame->bh);
1850         if (err)
1851                 goto journal_error;
1852
1853         data2 = bh2->b_data;
1854
1855         /* create map in the end of data2 block */
1856         map = (struct dx_map_entry *) (data2 + blocksize);
1857         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1858                              blocksize, hinfo, map);
1859         map -= count;
1860         dx_sort_map(map, count);
1861         /* Split the existing block in the middle, size-wise */
1862         size = 0;
1863         move = 0;
1864         for (i = count-1; i >= 0; i--) {
1865                 /* is more than half of this entry in 2nd half of the block? */
1866                 if (size + map[i].size/2 > blocksize/2)
1867                         break;
1868                 size += map[i].size;
1869                 move++;
1870         }
1871         /* map index at which we will split */
1872         split = count - move;
1873         hash2 = map[split].hash;
1874         continued = hash2 == map[split - 1].hash;
1875         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1876                         (unsigned long)dx_get_block(frame->at),
1877                                         hash2, split, count-split));
1878
1879         /* Fancy dance to stay within two buffers */
1880         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1881                               blocksize);
1882         de = dx_pack_dirents(data1, blocksize);
1883         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1884                                            (char *) de,
1885                                            blocksize);
1886         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1887                                             (char *) de2,
1888                                             blocksize);
1889         if (csum_size) {
1890                 ext4_initialize_dirent_tail(*bh, blocksize);
1891                 ext4_initialize_dirent_tail(bh2, blocksize);
1892         }
1893
1894         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1895                         blocksize, 1));
1896         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1897                         blocksize, 1));
1898
1899         /* Which block gets the new entry? */
1900         if (hinfo->hash >= hash2) {
1901                 swap(*bh, bh2);
1902                 de = de2;
1903         }
1904         dx_insert_block(frame, hash2 + continued, newblock);
1905         err = ext4_handle_dirty_dirblock(handle, dir, bh2);
1906         if (err)
1907                 goto journal_error;
1908         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1909         if (err)
1910                 goto journal_error;
1911         brelse(bh2);
1912         dxtrace(dx_show_index("frame", frame->entries));
1913         return de;
1914
1915 journal_error:
1916         brelse(*bh);
1917         brelse(bh2);
1918         *bh = NULL;
1919         ext4_std_error(dir->i_sb, err);
1920         return ERR_PTR(err);
1921 }
1922
1923 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1924                       struct buffer_head *bh,
1925                       void *buf, int buf_size,
1926                       struct ext4_filename *fname,
1927                       struct ext4_dir_entry_2 **dest_de)
1928 {
1929         struct ext4_dir_entry_2 *de;
1930         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1931         int nlen, rlen;
1932         unsigned int offset = 0;
1933         char *top;
1934
1935         de = (struct ext4_dir_entry_2 *)buf;
1936         top = buf + buf_size - reclen;
1937         while ((char *) de <= top) {
1938                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1939                                          buf, buf_size, offset))
1940                         return -EFSCORRUPTED;
1941                 if (ext4_match(dir, fname, de))
1942                         return -EEXIST;
1943                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1944                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1945                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1946                         break;
1947                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1948                 offset += rlen;
1949         }
1950         if ((char *) de > top)
1951                 return -ENOSPC;
1952
1953         *dest_de = de;
1954         return 0;
1955 }
1956
1957 void ext4_insert_dentry(struct inode *inode,
1958                         struct ext4_dir_entry_2 *de,
1959                         int buf_size,
1960                         struct ext4_filename *fname)
1961 {
1962
1963         int nlen, rlen;
1964
1965         nlen = EXT4_DIR_REC_LEN(de->name_len);
1966         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1967         if (de->inode) {
1968                 struct ext4_dir_entry_2 *de1 =
1969                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1970                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1971                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1972                 de = de1;
1973         }
1974         de->file_type = EXT4_FT_UNKNOWN;
1975         de->inode = cpu_to_le32(inode->i_ino);
1976         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1977         de->name_len = fname_len(fname);
1978         memcpy(de->name, fname_name(fname), fname_len(fname));
1979 }
1980
1981 /*
1982  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1983  * it points to a directory entry which is guaranteed to be large
1984  * enough for new directory entry.  If de is NULL, then
1985  * add_dirent_to_buf will attempt search the directory block for
1986  * space.  It will return -ENOSPC if no space is available, and -EIO
1987  * and -EEXIST if directory entry already exists.
1988  */
1989 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1990                              struct inode *dir,
1991                              struct inode *inode, struct ext4_dir_entry_2 *de,
1992                              struct buffer_head *bh)
1993 {
1994         unsigned int    blocksize = dir->i_sb->s_blocksize;
1995         int             csum_size = 0;
1996         int             err, err2;
1997
1998         if (ext4_has_metadata_csum(inode->i_sb))
1999                 csum_size = sizeof(struct ext4_dir_entry_tail);
2000
2001         if (!de) {
2002                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
2003                                         blocksize - csum_size, fname, &de);
2004                 if (err)
2005                         return err;
2006         }
2007         BUFFER_TRACE(bh, "get_write_access");
2008         err = ext4_journal_get_write_access(handle, bh);
2009         if (err) {
2010                 ext4_std_error(dir->i_sb, err);
2011                 return err;
2012         }
2013
2014         /* By now the buffer is marked for journaling */
2015         ext4_insert_dentry(inode, de, blocksize, fname);
2016
2017         /*
2018          * XXX shouldn't update any times until successful
2019          * completion of syscall, but too many callers depend
2020          * on this.
2021          *
2022          * XXX similarly, too many callers depend on
2023          * ext4_new_inode() setting the times, but error
2024          * recovery deletes the inode, so the worst that can
2025          * happen is that the times are slightly out of date
2026          * and/or different from the directory change time.
2027          */
2028         dir->i_mtime = dir->i_ctime = current_time(dir);
2029         ext4_update_dx_flag(dir);
2030         inode_inc_iversion(dir);
2031         err2 = ext4_mark_inode_dirty(handle, dir);
2032         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2033         err = ext4_handle_dirty_dirblock(handle, dir, bh);
2034         if (err)
2035                 ext4_std_error(dir->i_sb, err);
2036         return err ? err : err2;
2037 }
2038
2039 /*
2040  * This converts a one block unindexed directory to a 3 block indexed
2041  * directory, and adds the dentry to the indexed directory.
2042  */
2043 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
2044                             struct inode *dir,
2045                             struct inode *inode, struct buffer_head *bh)
2046 {
2047         struct buffer_head *bh2;
2048         struct dx_root  *root;
2049         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2050         struct dx_entry *entries;
2051         struct ext4_dir_entry_2 *de, *de2;
2052         char            *data2, *top;
2053         unsigned        len;
2054         int             retval;
2055         unsigned        blocksize;
2056         ext4_lblk_t  block;
2057         struct fake_dirent *fde;
2058         int csum_size = 0;
2059
2060         if (ext4_has_metadata_csum(inode->i_sb))
2061                 csum_size = sizeof(struct ext4_dir_entry_tail);
2062
2063         blocksize =  dir->i_sb->s_blocksize;
2064         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2065         BUFFER_TRACE(bh, "get_write_access");
2066         retval = ext4_journal_get_write_access(handle, bh);
2067         if (retval) {
2068                 ext4_std_error(dir->i_sb, retval);
2069                 brelse(bh);
2070                 return retval;
2071         }
2072         root = (struct dx_root *) bh->b_data;
2073
2074         /* The 0th block becomes the root, move the dirents out */
2075         fde = &root->dotdot;
2076         de = (struct ext4_dir_entry_2 *)((char *)fde +
2077                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2078         if ((char *) de >= (((char *) root) + blocksize)) {
2079                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2080                 brelse(bh);
2081                 return -EFSCORRUPTED;
2082         }
2083         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2084
2085         /* Allocate new block for the 0th block's dirents */
2086         bh2 = ext4_append(handle, dir, &block);
2087         if (IS_ERR(bh2)) {
2088                 brelse(bh);
2089                 return PTR_ERR(bh2);
2090         }
2091         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2092         data2 = bh2->b_data;
2093
2094         memcpy(data2, de, len);
2095         de = (struct ext4_dir_entry_2 *) data2;
2096         top = data2 + len;
2097         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2098                 de = de2;
2099         de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
2100                                            (char *) de, blocksize);
2101
2102         if (csum_size)
2103                 ext4_initialize_dirent_tail(bh2, blocksize);
2104
2105         /* Initialize the root; the dot dirents already exist */
2106         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2107         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2108                                            blocksize);
2109         memset (&root->info, 0, sizeof(root->info));
2110         root->info.info_length = sizeof(root->info);
2111         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2112         entries = root->entries;
2113         dx_set_block(entries, 1);
2114         dx_set_count(entries, 1);
2115         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2116
2117         /* Initialize as for dx_probe */
2118         fname->hinfo.hash_version = root->info.hash_version;
2119         if (fname->hinfo.hash_version <= DX_HASH_TEA)
2120                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2121         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2122         ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo);
2123
2124         memset(frames, 0, sizeof(frames));
2125         frame = frames;
2126         frame->entries = entries;
2127         frame->at = entries;
2128         frame->bh = bh;
2129
2130         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2131         if (retval)
2132                 goto out_frames;
2133         retval = ext4_handle_dirty_dirblock(handle, dir, bh2);
2134         if (retval)
2135                 goto out_frames;
2136
2137         de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2138         if (IS_ERR(de)) {
2139                 retval = PTR_ERR(de);
2140                 goto out_frames;
2141         }
2142
2143         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2144 out_frames:
2145         /*
2146          * Even if the block split failed, we have to properly write
2147          * out all the changes we did so far. Otherwise we can end up
2148          * with corrupted filesystem.
2149          */
2150         if (retval)
2151                 ext4_mark_inode_dirty(handle, dir);
2152         dx_release(frames);
2153         brelse(bh2);
2154         return retval;
2155 }
2156
2157 /*
2158  *      ext4_add_entry()
2159  *
2160  * adds a file entry to the specified directory, using the same
2161  * semantics as ext4_find_entry(). It returns NULL if it failed.
2162  *
2163  * NOTE!! The inode part of 'de' is left at 0 - which means you
2164  * may not sleep between calling this and putting something into
2165  * the entry, as someone else might have used it while you slept.
2166  */
2167 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2168                           struct inode *inode)
2169 {
2170         struct inode *dir = d_inode(dentry->d_parent);
2171         struct buffer_head *bh = NULL;
2172         struct ext4_dir_entry_2 *de;
2173         struct super_block *sb;
2174 #ifdef CONFIG_UNICODE
2175         struct ext4_sb_info *sbi;
2176 #endif
2177         struct ext4_filename fname;
2178         int     retval;
2179         int     dx_fallback=0;
2180         unsigned blocksize;
2181         ext4_lblk_t block, blocks;
2182         int     csum_size = 0;
2183
2184         if (ext4_has_metadata_csum(inode->i_sb))
2185                 csum_size = sizeof(struct ext4_dir_entry_tail);
2186
2187         sb = dir->i_sb;
2188         blocksize = sb->s_blocksize;
2189         if (!dentry->d_name.len)
2190                 return -EINVAL;
2191
2192 #ifdef CONFIG_UNICODE
2193         sbi = EXT4_SB(sb);
2194         if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) &&
2195             sbi->s_encoding && utf8_validate(sbi->s_encoding, &dentry->d_name))
2196                 return -EINVAL;
2197 #endif
2198
2199         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2200         if (retval)
2201                 return retval;
2202
2203         if (ext4_has_inline_data(dir)) {
2204                 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2205                 if (retval < 0)
2206                         goto out;
2207                 if (retval == 1) {
2208                         retval = 0;
2209                         goto out;
2210                 }
2211         }
2212
2213         if (is_dx(dir)) {
2214                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2215                 if (!retval || (retval != ERR_BAD_DX_DIR))
2216                         goto out;
2217                 /* Can we just ignore htree data? */
2218                 if (ext4_has_metadata_csum(sb)) {
2219                         EXT4_ERROR_INODE(dir,
2220                                 "Directory has corrupted htree index.");
2221                         retval = -EFSCORRUPTED;
2222                         goto out;
2223                 }
2224                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2225                 dx_fallback++;
2226                 retval = ext4_mark_inode_dirty(handle, dir);
2227                 if (unlikely(retval))
2228                         goto out;
2229         }
2230         blocks = dir->i_size >> sb->s_blocksize_bits;
2231         for (block = 0; block < blocks; block++) {
2232                 bh = ext4_read_dirblock(dir, block, DIRENT);
2233                 if (bh == NULL) {
2234                         bh = ext4_bread(handle, dir, block,
2235                                         EXT4_GET_BLOCKS_CREATE);
2236                         goto add_to_new_block;
2237                 }
2238                 if (IS_ERR(bh)) {
2239                         retval = PTR_ERR(bh);
2240                         bh = NULL;
2241                         goto out;
2242                 }
2243                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2244                                            NULL, bh);
2245                 if (retval != -ENOSPC)
2246                         goto out;
2247
2248                 if (blocks == 1 && !dx_fallback &&
2249                     ext4_has_feature_dir_index(sb)) {
2250                         retval = make_indexed_dir(handle, &fname, dir,
2251                                                   inode, bh);
2252                         bh = NULL; /* make_indexed_dir releases bh */
2253                         goto out;
2254                 }
2255                 brelse(bh);
2256         }
2257         bh = ext4_append(handle, dir, &block);
2258 add_to_new_block:
2259         if (IS_ERR(bh)) {
2260                 retval = PTR_ERR(bh);
2261                 bh = NULL;
2262                 goto out;
2263         }
2264         de = (struct ext4_dir_entry_2 *) bh->b_data;
2265         de->inode = 0;
2266         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2267
2268         if (csum_size)
2269                 ext4_initialize_dirent_tail(bh, blocksize);
2270
2271         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2272 out:
2273         ext4_fname_free_filename(&fname);
2274         brelse(bh);
2275         if (retval == 0)
2276                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2277         return retval;
2278 }
2279
2280 /*
2281  * Returns 0 for success, or a negative error value
2282  */
2283 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2284                              struct inode *dir, struct inode *inode)
2285 {
2286         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2287         struct dx_entry *entries, *at;
2288         struct buffer_head *bh;
2289         struct super_block *sb = dir->i_sb;
2290         struct ext4_dir_entry_2 *de;
2291         int restart;
2292         int err;
2293
2294 again:
2295         restart = 0;
2296         frame = dx_probe(fname, dir, NULL, frames);
2297         if (IS_ERR(frame))
2298                 return PTR_ERR(frame);
2299         entries = frame->entries;
2300         at = frame->at;
2301         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
2302         if (IS_ERR(bh)) {
2303                 err = PTR_ERR(bh);
2304                 bh = NULL;
2305                 goto cleanup;
2306         }
2307
2308         BUFFER_TRACE(bh, "get_write_access");
2309         err = ext4_journal_get_write_access(handle, bh);
2310         if (err)
2311                 goto journal_error;
2312
2313         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2314         if (err != -ENOSPC)
2315                 goto cleanup;
2316
2317         err = 0;
2318         /* Block full, should compress but for now just split */
2319         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2320                        dx_get_count(entries), dx_get_limit(entries)));
2321         /* Need to split index? */
2322         if (dx_get_count(entries) == dx_get_limit(entries)) {
2323                 ext4_lblk_t newblock;
2324                 int levels = frame - frames + 1;
2325                 unsigned int icount;
2326                 int add_level = 1;
2327                 struct dx_entry *entries2;
2328                 struct dx_node *node2;
2329                 struct buffer_head *bh2;
2330
2331                 while (frame > frames) {
2332                         if (dx_get_count((frame - 1)->entries) <
2333                             dx_get_limit((frame - 1)->entries)) {
2334                                 add_level = 0;
2335                                 break;
2336                         }
2337                         frame--; /* split higher index block */
2338                         at = frame->at;
2339                         entries = frame->entries;
2340                         restart = 1;
2341                 }
2342                 if (add_level && levels == ext4_dir_htree_level(sb)) {
2343                         ext4_warning(sb, "Directory (ino: %lu) index full, "
2344                                          "reach max htree level :%d",
2345                                          dir->i_ino, levels);
2346                         if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2347                                 ext4_warning(sb, "Large directory feature is "
2348                                                  "not enabled on this "
2349                                                  "filesystem");
2350                         }
2351                         err = -ENOSPC;
2352                         goto cleanup;
2353                 }
2354                 icount = dx_get_count(entries);
2355                 bh2 = ext4_append(handle, dir, &newblock);
2356                 if (IS_ERR(bh2)) {
2357                         err = PTR_ERR(bh2);
2358                         goto cleanup;
2359                 }
2360                 node2 = (struct dx_node *)(bh2->b_data);
2361                 entries2 = node2->entries;
2362                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2363                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2364                                                            sb->s_blocksize);
2365                 BUFFER_TRACE(frame->bh, "get_write_access");
2366                 err = ext4_journal_get_write_access(handle, frame->bh);
2367                 if (err)
2368                         goto journal_error;
2369                 if (!add_level) {
2370                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2371                         unsigned hash2 = dx_get_hash(entries + icount1);
2372                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2373                                        icount1, icount2));
2374
2375                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2376                         err = ext4_journal_get_write_access(handle,
2377                                                              (frame - 1)->bh);
2378                         if (err)
2379                                 goto journal_error;
2380
2381                         memcpy((char *) entries2, (char *) (entries + icount1),
2382                                icount2 * sizeof(struct dx_entry));
2383                         dx_set_count(entries, icount1);
2384                         dx_set_count(entries2, icount2);
2385                         dx_set_limit(entries2, dx_node_limit(dir));
2386
2387                         /* Which index block gets the new entry? */
2388                         if (at - entries >= icount1) {
2389                                 frame->at = at = at - entries - icount1 + entries2;
2390                                 frame->entries = entries = entries2;
2391                                 swap(frame->bh, bh2);
2392                         }
2393                         dx_insert_block((frame - 1), hash2, newblock);
2394                         dxtrace(dx_show_index("node", frame->entries));
2395                         dxtrace(dx_show_index("node",
2396                                ((struct dx_node *) bh2->b_data)->entries));
2397                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2398                         if (err)
2399                                 goto journal_error;
2400                         brelse (bh2);
2401                         err = ext4_handle_dirty_dx_node(handle, dir,
2402                                                    (frame - 1)->bh);
2403                         if (err)
2404                                 goto journal_error;
2405                         if (restart) {
2406                                 err = ext4_handle_dirty_dx_node(handle, dir,
2407                                                            frame->bh);
2408                                 goto journal_error;
2409                         }
2410                 } else {
2411                         struct dx_root *dxroot;
2412                         memcpy((char *) entries2, (char *) entries,
2413                                icount * sizeof(struct dx_entry));
2414                         dx_set_limit(entries2, dx_node_limit(dir));
2415
2416                         /* Set up root */
2417                         dx_set_count(entries, 1);
2418                         dx_set_block(entries + 0, newblock);
2419                         dxroot = (struct dx_root *)frames[0].bh->b_data;
2420                         dxroot->info.indirect_levels += 1;
2421                         dxtrace(printk(KERN_DEBUG
2422                                        "Creating %d level index...\n",
2423                                        dxroot->info.indirect_levels));
2424                         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2425                         if (err)
2426                                 goto journal_error;
2427                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2428                         brelse(bh2);
2429                         restart = 1;
2430                         goto journal_error;
2431                 }
2432         }
2433         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2434         if (IS_ERR(de)) {
2435                 err = PTR_ERR(de);
2436                 goto cleanup;
2437         }
2438         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2439         goto cleanup;
2440
2441 journal_error:
2442         ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2443 cleanup:
2444         brelse(bh);
2445         dx_release(frames);
2446         /* @restart is true means htree-path has been changed, we need to
2447          * repeat dx_probe() to find out valid htree-path
2448          */
2449         if (restart && err == 0)
2450                 goto again;
2451         return err;
2452 }
2453
2454 /*
2455  * ext4_generic_delete_entry deletes a directory entry by merging it
2456  * with the previous entry
2457  */
2458 int ext4_generic_delete_entry(handle_t *handle,
2459                               struct inode *dir,
2460                               struct ext4_dir_entry_2 *de_del,
2461                               struct buffer_head *bh,
2462                               void *entry_buf,
2463                               int buf_size,
2464                               int csum_size)
2465 {
2466         struct ext4_dir_entry_2 *de, *pde;
2467         unsigned int blocksize = dir->i_sb->s_blocksize;
2468         int i;
2469
2470         i = 0;
2471         pde = NULL;
2472         de = (struct ext4_dir_entry_2 *)entry_buf;
2473         while (i < buf_size - csum_size) {
2474                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2475                                          bh->b_data, bh->b_size, i))
2476                         return -EFSCORRUPTED;
2477                 if (de == de_del)  {
2478                         if (pde)
2479                                 pde->rec_len = ext4_rec_len_to_disk(
2480                                         ext4_rec_len_from_disk(pde->rec_len,
2481                                                                blocksize) +
2482                                         ext4_rec_len_from_disk(de->rec_len,
2483                                                                blocksize),
2484                                         blocksize);
2485                         else
2486                                 de->inode = 0;
2487                         inode_inc_iversion(dir);
2488                         return 0;
2489                 }
2490                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2491                 pde = de;
2492                 de = ext4_next_entry(de, blocksize);
2493         }
2494         return -ENOENT;
2495 }
2496
2497 static int ext4_delete_entry(handle_t *handle,
2498                              struct inode *dir,
2499                              struct ext4_dir_entry_2 *de_del,
2500                              struct buffer_head *bh)
2501 {
2502         int err, csum_size = 0;
2503
2504         if (ext4_has_inline_data(dir)) {
2505                 int has_inline_data = 1;
2506                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2507                                                &has_inline_data);
2508                 if (has_inline_data)
2509                         return err;
2510         }
2511
2512         if (ext4_has_metadata_csum(dir->i_sb))
2513                 csum_size = sizeof(struct ext4_dir_entry_tail);
2514
2515         BUFFER_TRACE(bh, "get_write_access");
2516         err = ext4_journal_get_write_access(handle, bh);
2517         if (unlikely(err))
2518                 goto out;
2519
2520         err = ext4_generic_delete_entry(handle, dir, de_del,
2521                                         bh, bh->b_data,
2522                                         dir->i_sb->s_blocksize, csum_size);
2523         if (err)
2524                 goto out;
2525
2526         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2527         err = ext4_handle_dirty_dirblock(handle, dir, bh);
2528         if (unlikely(err))
2529                 goto out;
2530
2531         return 0;
2532 out:
2533         if (err != -ENOENT)
2534                 ext4_std_error(dir->i_sb, err);
2535         return err;
2536 }
2537
2538 /*
2539  * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2540  * since this indicates that nlinks count was previously 1 to avoid overflowing
2541  * the 16-bit i_links_count field on disk.  Directories with i_nlink == 1 mean
2542  * that subdirectory link counts are not being maintained accurately.
2543  *
2544  * The caller has already checked for i_nlink overflow in case the DIR_LINK
2545  * feature is not enabled and returned -EMLINK.  The is_dx() check is a proxy
2546  * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2547  * on regular files) and to avoid creating huge/slow non-HTREE directories.
2548  */
2549 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2550 {
2551         inc_nlink(inode);
2552         if (is_dx(inode) &&
2553             (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2554                 set_nlink(inode, 1);
2555 }
2556
2557 /*
2558  * If a directory had nlink == 1, then we should let it be 1. This indicates
2559  * directory has >EXT4_LINK_MAX subdirs.
2560  */
2561 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2562 {
2563         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2564                 drop_nlink(inode);
2565 }
2566
2567
2568 /*
2569  * Add non-directory inode to a directory. On success, the inode reference is
2570  * consumed by dentry is instantiation. This is also indicated by clearing of
2571  * *inodep pointer. On failure, the caller is responsible for dropping the
2572  * inode reference in the safe context.
2573  */
2574 static int ext4_add_nondir(handle_t *handle,
2575                 struct dentry *dentry, struct inode **inodep)
2576 {
2577         struct inode *dir = d_inode(dentry->d_parent);
2578         struct inode *inode = *inodep;
2579         int err = ext4_add_entry(handle, dentry, inode);
2580         if (!err) {
2581                 err = ext4_mark_inode_dirty(handle, inode);
2582                 if (IS_DIRSYNC(dir))
2583                         ext4_handle_sync(handle);
2584                 d_instantiate_new(dentry, inode);
2585                 *inodep = NULL;
2586                 return err;
2587         }
2588         drop_nlink(inode);
2589         ext4_orphan_add(handle, inode);
2590         unlock_new_inode(inode);
2591         return err;
2592 }
2593
2594 /*
2595  * By the time this is called, we already have created
2596  * the directory cache entry for the new file, but it
2597  * is so far negative - it has no inode.
2598  *
2599  * If the create succeeds, we fill in the inode information
2600  * with d_instantiate().
2601  */
2602 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2603                        bool excl)
2604 {
2605         handle_t *handle;
2606         struct inode *inode;
2607         int err, credits, retries = 0;
2608
2609         err = dquot_initialize(dir);
2610         if (err)
2611                 return err;
2612
2613         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2614                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2615 retry:
2616         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2617                                             NULL, EXT4_HT_DIR, credits);
2618         handle = ext4_journal_current_handle();
2619         err = PTR_ERR(inode);
2620         if (!IS_ERR(inode)) {
2621                 inode->i_op = &ext4_file_inode_operations;
2622                 inode->i_fop = &ext4_file_operations;
2623                 ext4_set_aops(inode);
2624                 err = ext4_add_nondir(handle, dentry, &inode);
2625         }
2626         if (handle)
2627                 ext4_journal_stop(handle);
2628         if (!IS_ERR_OR_NULL(inode))
2629                 iput(inode);
2630         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2631                 goto retry;
2632         return err;
2633 }
2634
2635 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2636                       umode_t mode, dev_t rdev)
2637 {
2638         handle_t *handle;
2639         struct inode *inode;
2640         int err, credits, retries = 0;
2641
2642         err = dquot_initialize(dir);
2643         if (err)
2644                 return err;
2645
2646         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2647                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2648 retry:
2649         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2650                                             NULL, EXT4_HT_DIR, credits);
2651         handle = ext4_journal_current_handle();
2652         err = PTR_ERR(inode);
2653         if (!IS_ERR(inode)) {
2654                 init_special_inode(inode, inode->i_mode, rdev);
2655                 inode->i_op = &ext4_special_inode_operations;
2656                 err = ext4_add_nondir(handle, dentry, &inode);
2657         }
2658         if (handle)
2659                 ext4_journal_stop(handle);
2660         if (!IS_ERR_OR_NULL(inode))
2661                 iput(inode);
2662         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2663                 goto retry;
2664         return err;
2665 }
2666
2667 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2668 {
2669         handle_t *handle;
2670         struct inode *inode;
2671         int err, retries = 0;
2672
2673         err = dquot_initialize(dir);
2674         if (err)
2675                 return err;
2676
2677 retry:
2678         inode = ext4_new_inode_start_handle(dir, mode,
2679                                             NULL, 0, NULL,
2680                                             EXT4_HT_DIR,
2681                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2682                           4 + EXT4_XATTR_TRANS_BLOCKS);
2683         handle = ext4_journal_current_handle();
2684         err = PTR_ERR(inode);
2685         if (!IS_ERR(inode)) {
2686                 inode->i_op = &ext4_file_inode_operations;
2687                 inode->i_fop = &ext4_file_operations;
2688                 ext4_set_aops(inode);
2689                 d_tmpfile(dentry, inode);
2690                 err = ext4_orphan_add(handle, inode);
2691                 if (err)
2692                         goto err_unlock_inode;
2693                 mark_inode_dirty(inode);
2694                 unlock_new_inode(inode);
2695         }
2696         if (handle)
2697                 ext4_journal_stop(handle);
2698         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2699                 goto retry;
2700         return err;
2701 err_unlock_inode:
2702         ext4_journal_stop(handle);
2703         unlock_new_inode(inode);
2704         return err;
2705 }
2706
2707 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2708                           struct ext4_dir_entry_2 *de,
2709                           int blocksize, int csum_size,
2710                           unsigned int parent_ino, int dotdot_real_len)
2711 {
2712         de->inode = cpu_to_le32(inode->i_ino);
2713         de->name_len = 1;
2714         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2715                                            blocksize);
2716         strcpy(de->name, ".");
2717         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2718
2719         de = ext4_next_entry(de, blocksize);
2720         de->inode = cpu_to_le32(parent_ino);
2721         de->name_len = 2;
2722         if (!dotdot_real_len)
2723                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2724                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2725                                         blocksize);
2726         else
2727                 de->rec_len = ext4_rec_len_to_disk(
2728                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2729         strcpy(de->name, "..");
2730         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2731
2732         return ext4_next_entry(de, blocksize);
2733 }
2734
2735 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2736                              struct inode *inode)
2737 {
2738         struct buffer_head *dir_block = NULL;
2739         struct ext4_dir_entry_2 *de;
2740         ext4_lblk_t block = 0;
2741         unsigned int blocksize = dir->i_sb->s_blocksize;
2742         int csum_size = 0;
2743         int err;
2744
2745         if (ext4_has_metadata_csum(dir->i_sb))
2746                 csum_size = sizeof(struct ext4_dir_entry_tail);
2747
2748         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2749                 err = ext4_try_create_inline_dir(handle, dir, inode);
2750                 if (err < 0 && err != -ENOSPC)
2751                         goto out;
2752                 if (!err)
2753                         goto out;
2754         }
2755
2756         inode->i_size = 0;
2757         dir_block = ext4_append(handle, inode, &block);
2758         if (IS_ERR(dir_block))
2759                 return PTR_ERR(dir_block);
2760         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2761         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2762         set_nlink(inode, 2);
2763         if (csum_size)
2764                 ext4_initialize_dirent_tail(dir_block, blocksize);
2765
2766         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2767         err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
2768         if (err)
2769                 goto out;
2770         set_buffer_verified(dir_block);
2771 out:
2772         brelse(dir_block);
2773         return err;
2774 }
2775
2776 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2777 {
2778         handle_t *handle;
2779         struct inode *inode;
2780         int err, err2 = 0, credits, retries = 0;
2781
2782         if (EXT4_DIR_LINK_MAX(dir))
2783                 return -EMLINK;
2784
2785         err = dquot_initialize(dir);
2786         if (err)
2787                 return err;
2788
2789         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2790                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2791 retry:
2792         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2793                                             &dentry->d_name,
2794                                             0, NULL, EXT4_HT_DIR, credits);
2795         handle = ext4_journal_current_handle();
2796         err = PTR_ERR(inode);
2797         if (IS_ERR(inode))
2798                 goto out_stop;
2799
2800         inode->i_op = &ext4_dir_inode_operations;
2801         inode->i_fop = &ext4_dir_operations;
2802         err = ext4_init_new_dir(handle, dir, inode);
2803         if (err)
2804                 goto out_clear_inode;
2805         err = ext4_mark_inode_dirty(handle, inode);
2806         if (!err)
2807                 err = ext4_add_entry(handle, dentry, inode);
2808         if (err) {
2809 out_clear_inode:
2810                 clear_nlink(inode);
2811                 ext4_orphan_add(handle, inode);
2812                 unlock_new_inode(inode);
2813                 err2 = ext4_mark_inode_dirty(handle, inode);
2814                 if (unlikely(err2))
2815                         err = err2;
2816                 ext4_journal_stop(handle);
2817                 iput(inode);
2818                 goto out_retry;
2819         }
2820         ext4_inc_count(handle, dir);
2821         ext4_update_dx_flag(dir);
2822         err = ext4_mark_inode_dirty(handle, dir);
2823         if (err)
2824                 goto out_clear_inode;
2825         d_instantiate_new(dentry, inode);
2826         if (IS_DIRSYNC(dir))
2827                 ext4_handle_sync(handle);
2828
2829 out_stop:
2830         if (handle)
2831                 ext4_journal_stop(handle);
2832 out_retry:
2833         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2834                 goto retry;
2835         return err;
2836 }
2837
2838 /*
2839  * routine to check that the specified directory is empty (for rmdir)
2840  */
2841 bool ext4_empty_dir(struct inode *inode)
2842 {
2843         unsigned int offset;
2844         struct buffer_head *bh;
2845         struct ext4_dir_entry_2 *de;
2846         struct super_block *sb;
2847
2848         if (ext4_has_inline_data(inode)) {
2849                 int has_inline_data = 1;
2850                 int ret;
2851
2852                 ret = empty_inline_dir(inode, &has_inline_data);
2853                 if (has_inline_data)
2854                         return ret;
2855         }
2856
2857         sb = inode->i_sb;
2858         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2859                 EXT4_ERROR_INODE(inode, "invalid size");
2860                 return true;
2861         }
2862         /* The first directory block must not be a hole,
2863          * so treat it as DIRENT_HTREE
2864          */
2865         bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
2866         if (IS_ERR(bh))
2867                 return true;
2868
2869         de = (struct ext4_dir_entry_2 *) bh->b_data;
2870         if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
2871                                  0) ||
2872             le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
2873                 ext4_warning_inode(inode, "directory missing '.'");
2874                 brelse(bh);
2875                 return true;
2876         }
2877         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2878         de = ext4_next_entry(de, sb->s_blocksize);
2879         if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
2880                                  offset) ||
2881             le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
2882                 ext4_warning_inode(inode, "directory missing '..'");
2883                 brelse(bh);
2884                 return true;
2885         }
2886         offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2887         while (offset < inode->i_size) {
2888                 if (!(offset & (sb->s_blocksize - 1))) {
2889                         unsigned int lblock;
2890                         brelse(bh);
2891                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2892                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2893                         if (bh == NULL) {
2894                                 offset += sb->s_blocksize;
2895                                 continue;
2896                         }
2897                         if (IS_ERR(bh))
2898                                 return true;
2899                 }
2900                 de = (struct ext4_dir_entry_2 *) (bh->b_data +
2901                                         (offset & (sb->s_blocksize - 1)));
2902                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2903                                          bh->b_data, bh->b_size, offset)) {
2904                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2905                         continue;
2906                 }
2907                 if (le32_to_cpu(de->inode)) {
2908                         brelse(bh);
2909                         return false;
2910                 }
2911                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2912         }
2913         brelse(bh);
2914         return true;
2915 }
2916
2917 /*
2918  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2919  * such inodes, starting at the superblock, in case we crash before the
2920  * file is closed/deleted, or in case the inode truncate spans multiple
2921  * transactions and the last transaction is not recovered after a crash.
2922  *
2923  * At filesystem recovery time, we walk this list deleting unlinked
2924  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2925  *
2926  * Orphan list manipulation functions must be called under i_mutex unless
2927  * we are just creating the inode or deleting it.
2928  */
2929 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2930 {
2931         struct super_block *sb = inode->i_sb;
2932         struct ext4_sb_info *sbi = EXT4_SB(sb);
2933         struct ext4_iloc iloc;
2934         int err = 0, rc;
2935         bool dirty = false;
2936
2937         if (!sbi->s_journal || is_bad_inode(inode))
2938                 return 0;
2939
2940         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2941                      !inode_is_locked(inode));
2942         /*
2943          * Exit early if inode already is on orphan list. This is a big speedup
2944          * since we don't have to contend on the global s_orphan_lock.
2945          */
2946         if (!list_empty(&EXT4_I(inode)->i_orphan))
2947                 return 0;
2948
2949         /*
2950          * Orphan handling is only valid for files with data blocks
2951          * being truncated, or files being unlinked. Note that we either
2952          * hold i_mutex, or the inode can not be referenced from outside,
2953          * so i_nlink should not be bumped due to race
2954          */
2955         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2956                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2957
2958         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2959         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2960         if (err)
2961                 goto out;
2962
2963         err = ext4_reserve_inode_write(handle, inode, &iloc);
2964         if (err)
2965                 goto out;
2966
2967         mutex_lock(&sbi->s_orphan_lock);
2968         /*
2969          * Due to previous errors inode may be already a part of on-disk
2970          * orphan list. If so skip on-disk list modification.
2971          */
2972         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2973             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2974                 /* Insert this inode at the head of the on-disk orphan list */
2975                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2976                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2977                 dirty = true;
2978         }
2979         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2980         mutex_unlock(&sbi->s_orphan_lock);
2981
2982         if (dirty) {
2983                 err = ext4_handle_dirty_super(handle, sb);
2984                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2985                 if (!err)
2986                         err = rc;
2987                 if (err) {
2988                         /*
2989                          * We have to remove inode from in-memory list if
2990                          * addition to on disk orphan list failed. Stray orphan
2991                          * list entries can cause panics at unmount time.
2992                          */
2993                         mutex_lock(&sbi->s_orphan_lock);
2994                         list_del_init(&EXT4_I(inode)->i_orphan);
2995                         mutex_unlock(&sbi->s_orphan_lock);
2996                 }
2997         } else
2998                 brelse(iloc.bh);
2999
3000         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
3001         jbd_debug(4, "orphan inode %lu will point to %d\n",
3002                         inode->i_ino, NEXT_ORPHAN(inode));
3003 out:
3004         ext4_std_error(sb, err);
3005         return err;
3006 }
3007
3008 /*
3009  * ext4_orphan_del() removes an unlinked or truncated inode from the list
3010  * of such inodes stored on disk, because it is finally being cleaned up.
3011  */
3012 int ext4_orphan_del(handle_t *handle, struct inode *inode)
3013 {
3014         struct list_head *prev;
3015         struct ext4_inode_info *ei = EXT4_I(inode);
3016         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3017         __u32 ino_next;
3018         struct ext4_iloc iloc;
3019         int err = 0;
3020
3021         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
3022                 return 0;
3023
3024         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
3025                      !inode_is_locked(inode));
3026         /* Do this quick check before taking global s_orphan_lock. */
3027         if (list_empty(&ei->i_orphan))
3028                 return 0;
3029
3030         if (handle) {
3031                 /* Grab inode buffer early before taking global s_orphan_lock */
3032                 err = ext4_reserve_inode_write(handle, inode, &iloc);
3033         }
3034
3035         mutex_lock(&sbi->s_orphan_lock);
3036         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
3037
3038         prev = ei->i_orphan.prev;
3039         list_del_init(&ei->i_orphan);
3040
3041         /* If we're on an error path, we may not have a valid
3042          * transaction handle with which to update the orphan list on
3043          * disk, but we still need to remove the inode from the linked
3044          * list in memory. */
3045         if (!handle || err) {
3046                 mutex_unlock(&sbi->s_orphan_lock);
3047                 goto out_err;
3048         }
3049
3050         ino_next = NEXT_ORPHAN(inode);
3051         if (prev == &sbi->s_orphan) {
3052                 jbd_debug(4, "superblock will point to %u\n", ino_next);
3053                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
3054                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
3055                 if (err) {
3056                         mutex_unlock(&sbi->s_orphan_lock);
3057                         goto out_brelse;
3058                 }
3059                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
3060                 mutex_unlock(&sbi->s_orphan_lock);
3061                 err = ext4_handle_dirty_super(handle, inode->i_sb);
3062         } else {
3063                 struct ext4_iloc iloc2;
3064                 struct inode *i_prev =
3065                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
3066
3067                 jbd_debug(4, "orphan inode %lu will point to %u\n",
3068                           i_prev->i_ino, ino_next);
3069                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
3070                 if (err) {
3071                         mutex_unlock(&sbi->s_orphan_lock);
3072                         goto out_brelse;
3073                 }
3074                 NEXT_ORPHAN(i_prev) = ino_next;
3075                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
3076                 mutex_unlock(&sbi->s_orphan_lock);
3077         }
3078         if (err)
3079                 goto out_brelse;
3080         NEXT_ORPHAN(inode) = 0;
3081         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
3082 out_err:
3083         ext4_std_error(inode->i_sb, err);
3084         return err;
3085
3086 out_brelse:
3087         brelse(iloc.bh);
3088         goto out_err;
3089 }
3090
3091 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3092 {
3093         int retval;
3094         struct inode *inode;
3095         struct buffer_head *bh;
3096         struct ext4_dir_entry_2 *de;
3097         handle_t *handle = NULL;
3098
3099         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3100                 return -EIO;
3101
3102         /* Initialize quotas before so that eventual writes go in
3103          * separate transaction */
3104         retval = dquot_initialize(dir);
3105         if (retval)
3106                 return retval;
3107         retval = dquot_initialize(d_inode(dentry));
3108         if (retval)
3109                 return retval;
3110
3111         retval = -ENOENT;
3112         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3113         if (IS_ERR(bh))
3114                 return PTR_ERR(bh);
3115         if (!bh)
3116                 goto end_rmdir;
3117
3118         inode = d_inode(dentry);
3119
3120         retval = -EFSCORRUPTED;
3121         if (le32_to_cpu(de->inode) != inode->i_ino)
3122                 goto end_rmdir;
3123
3124         retval = -ENOTEMPTY;
3125         if (!ext4_empty_dir(inode))
3126                 goto end_rmdir;
3127
3128         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3129                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3130         if (IS_ERR(handle)) {
3131                 retval = PTR_ERR(handle);
3132                 handle = NULL;
3133                 goto end_rmdir;
3134         }
3135
3136         if (IS_DIRSYNC(dir))
3137                 ext4_handle_sync(handle);
3138
3139         retval = ext4_delete_entry(handle, dir, de, bh);
3140         if (retval)
3141                 goto end_rmdir;
3142         if (!EXT4_DIR_LINK_EMPTY(inode))
3143                 ext4_warning_inode(inode,
3144                              "empty directory '%.*s' has too many links (%u)",
3145                              dentry->d_name.len, dentry->d_name.name,
3146                              inode->i_nlink);
3147         inode_inc_iversion(inode);
3148         clear_nlink(inode);
3149         /* There's no need to set i_disksize: the fact that i_nlink is
3150          * zero will ensure that the right thing happens during any
3151          * recovery. */
3152         inode->i_size = 0;
3153         ext4_orphan_add(handle, inode);
3154         inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
3155         retval = ext4_mark_inode_dirty(handle, inode);
3156         if (retval)
3157                 goto end_rmdir;
3158         ext4_dec_count(handle, dir);
3159         ext4_update_dx_flag(dir);
3160         retval = ext4_mark_inode_dirty(handle, dir);
3161
3162 #ifdef CONFIG_UNICODE
3163         /* VFS negative dentries are incompatible with Encoding and
3164          * Case-insensitiveness. Eventually we'll want avoid
3165          * invalidating the dentries here, alongside with returning the
3166          * negative dentries at ext4_lookup(), when it is better
3167          * supported by the VFS for the CI case.
3168          */
3169         if (IS_CASEFOLDED(dir))
3170                 d_invalidate(dentry);
3171 #endif
3172
3173 end_rmdir:
3174         brelse(bh);
3175         if (handle)
3176                 ext4_journal_stop(handle);
3177         return retval;
3178 }
3179
3180 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3181 {
3182         int retval;
3183         struct inode *inode;
3184         struct buffer_head *bh;
3185         struct ext4_dir_entry_2 *de;
3186         handle_t *handle = NULL;
3187
3188         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3189                 return -EIO;
3190
3191         trace_ext4_unlink_enter(dir, dentry);
3192         /* Initialize quotas before so that eventual writes go
3193          * in separate transaction */
3194         retval = dquot_initialize(dir);
3195         if (retval)
3196                 return retval;
3197         retval = dquot_initialize(d_inode(dentry));
3198         if (retval)
3199                 return retval;
3200
3201         retval = -ENOENT;
3202         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3203         if (IS_ERR(bh))
3204                 return PTR_ERR(bh);
3205         if (!bh)
3206                 goto end_unlink;
3207
3208         inode = d_inode(dentry);
3209
3210         retval = -EFSCORRUPTED;
3211         if (le32_to_cpu(de->inode) != inode->i_ino)
3212                 goto end_unlink;
3213
3214         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3215                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3216         if (IS_ERR(handle)) {
3217                 retval = PTR_ERR(handle);
3218                 handle = NULL;
3219                 goto end_unlink;
3220         }
3221
3222         if (IS_DIRSYNC(dir))
3223                 ext4_handle_sync(handle);
3224
3225         retval = ext4_delete_entry(handle, dir, de, bh);
3226         if (retval)
3227                 goto end_unlink;
3228         dir->i_ctime = dir->i_mtime = current_time(dir);
3229         ext4_update_dx_flag(dir);
3230         retval = ext4_mark_inode_dirty(handle, dir);
3231         if (retval)
3232                 goto end_unlink;
3233         if (inode->i_nlink == 0)
3234                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3235                                    dentry->d_name.len, dentry->d_name.name);
3236         else
3237                 drop_nlink(inode);
3238         if (!inode->i_nlink)
3239                 ext4_orphan_add(handle, inode);
3240         inode->i_ctime = current_time(inode);
3241         retval = ext4_mark_inode_dirty(handle, inode);
3242
3243 #ifdef CONFIG_UNICODE
3244         /* VFS negative dentries are incompatible with Encoding and
3245          * Case-insensitiveness. Eventually we'll want avoid
3246          * invalidating the dentries here, alongside with returning the
3247          * negative dentries at ext4_lookup(), when it is  better
3248          * supported by the VFS for the CI case.
3249          */
3250         if (IS_CASEFOLDED(dir))
3251                 d_invalidate(dentry);
3252 #endif
3253
3254 end_unlink:
3255         brelse(bh);
3256         if (handle)
3257                 ext4_journal_stop(handle);
3258         trace_ext4_unlink_exit(dentry, retval);
3259         return retval;
3260 }
3261
3262 static int ext4_symlink(struct inode *dir,
3263                         struct dentry *dentry, const char *symname)
3264 {
3265         handle_t *handle;
3266         struct inode *inode;
3267         int err, len = strlen(symname);
3268         int credits;
3269         struct fscrypt_str disk_link;
3270
3271         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3272                 return -EIO;
3273
3274         err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3275                                       &disk_link);
3276         if (err)
3277                 return err;
3278
3279         err = dquot_initialize(dir);
3280         if (err)
3281                 return err;
3282
3283         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3284                 /*
3285                  * For non-fast symlinks, we just allocate inode and put it on
3286                  * orphan list in the first transaction => we need bitmap,
3287                  * group descriptor, sb, inode block, quota blocks, and
3288                  * possibly selinux xattr blocks.
3289                  */
3290                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3291                           EXT4_XATTR_TRANS_BLOCKS;
3292         } else {
3293                 /*
3294                  * Fast symlink. We have to add entry to directory
3295                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3296                  * allocate new inode (bitmap, group descriptor, inode block,
3297                  * quota blocks, sb is already counted in previous macros).
3298                  */
3299                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3300                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3301         }
3302
3303         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3304                                             &dentry->d_name, 0, NULL,
3305                                             EXT4_HT_DIR, credits);
3306         handle = ext4_journal_current_handle();
3307         if (IS_ERR(inode)) {
3308                 if (handle)
3309                         ext4_journal_stop(handle);
3310                 return PTR_ERR(inode);
3311         }
3312
3313         if (IS_ENCRYPTED(inode)) {
3314                 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3315                 if (err)
3316                         goto err_drop_inode;
3317                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3318         }
3319
3320         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3321                 if (!IS_ENCRYPTED(inode))
3322                         inode->i_op = &ext4_symlink_inode_operations;
3323                 inode_nohighmem(inode);
3324                 ext4_set_aops(inode);
3325                 /*
3326                  * We cannot call page_symlink() with transaction started
3327                  * because it calls into ext4_write_begin() which can wait
3328                  * for transaction commit if we are running out of space
3329                  * and thus we deadlock. So we have to stop transaction now
3330                  * and restart it when symlink contents is written.
3331                  *
3332                  * To keep fs consistent in case of crash, we have to put inode
3333                  * to orphan list in the mean time.
3334                  */
3335                 drop_nlink(inode);
3336                 err = ext4_orphan_add(handle, inode);
3337                 ext4_journal_stop(handle);
3338                 handle = NULL;
3339                 if (err)
3340                         goto err_drop_inode;
3341                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3342                 if (err)
3343                         goto err_drop_inode;
3344                 /*
3345                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3346                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3347                  */
3348                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3349                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3350                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3351                 if (IS_ERR(handle)) {
3352                         err = PTR_ERR(handle);
3353                         handle = NULL;
3354                         goto err_drop_inode;
3355                 }
3356                 set_nlink(inode, 1);
3357                 err = ext4_orphan_del(handle, inode);
3358                 if (err)
3359                         goto err_drop_inode;
3360         } else {
3361                 /* clear the extent format for fast symlink */
3362                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3363                 if (!IS_ENCRYPTED(inode)) {
3364                         inode->i_op = &ext4_fast_symlink_inode_operations;
3365                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3366                 }
3367                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3368                        disk_link.len);
3369                 inode->i_size = disk_link.len - 1;
3370         }
3371         EXT4_I(inode)->i_disksize = inode->i_size;
3372         err = ext4_add_nondir(handle, dentry, &inode);
3373         if (handle)
3374                 ext4_journal_stop(handle);
3375         if (inode)
3376                 iput(inode);
3377         goto out_free_encrypted_link;
3378
3379 err_drop_inode:
3380         if (handle)
3381                 ext4_journal_stop(handle);
3382         clear_nlink(inode);
3383         unlock_new_inode(inode);
3384         iput(inode);
3385 out_free_encrypted_link:
3386         if (disk_link.name != (unsigned char *)symname)
3387                 kfree(disk_link.name);
3388         return err;
3389 }
3390
3391 static int ext4_link(struct dentry *old_dentry,
3392                      struct inode *dir, struct dentry *dentry)
3393 {
3394         handle_t *handle;
3395         struct inode *inode = d_inode(old_dentry);
3396         int err, retries = 0;
3397
3398         if (inode->i_nlink >= EXT4_LINK_MAX)
3399                 return -EMLINK;
3400
3401         err = fscrypt_prepare_link(old_dentry, dir, dentry);
3402         if (err)
3403                 return err;
3404
3405         if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3406             (!projid_eq(EXT4_I(dir)->i_projid,
3407                         EXT4_I(old_dentry->d_inode)->i_projid)))
3408                 return -EXDEV;
3409
3410         err = dquot_initialize(dir);
3411         if (err)
3412                 return err;
3413
3414 retry:
3415         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3416                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3417                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3418         if (IS_ERR(handle))
3419                 return PTR_ERR(handle);
3420
3421         if (IS_DIRSYNC(dir))
3422                 ext4_handle_sync(handle);
3423
3424         inode->i_ctime = current_time(inode);
3425         ext4_inc_count(handle, inode);
3426         ihold(inode);
3427
3428         err = ext4_add_entry(handle, dentry, inode);
3429         if (!err) {
3430                 err = ext4_mark_inode_dirty(handle, inode);
3431                 /* this can happen only for tmpfile being
3432                  * linked the first time
3433                  */
3434                 if (inode->i_nlink == 1)
3435                         ext4_orphan_del(handle, inode);
3436                 d_instantiate(dentry, inode);
3437         } else {
3438                 drop_nlink(inode);
3439                 iput(inode);
3440         }
3441         ext4_journal_stop(handle);
3442         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3443                 goto retry;
3444         return err;
3445 }
3446
3447
3448 /*
3449  * Try to find buffer head where contains the parent block.
3450  * It should be the inode block if it is inlined or the 1st block
3451  * if it is a normal dir.
3452  */
3453 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3454                                         struct inode *inode,
3455                                         int *retval,
3456                                         struct ext4_dir_entry_2 **parent_de,
3457                                         int *inlined)
3458 {
3459         struct buffer_head *bh;
3460
3461         if (!ext4_has_inline_data(inode)) {
3462                 /* The first directory block must not be a hole, so
3463                  * treat it as DIRENT_HTREE
3464                  */
3465                 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
3466                 if (IS_ERR(bh)) {
3467                         *retval = PTR_ERR(bh);
3468                         return NULL;
3469                 }
3470                 *parent_de = ext4_next_entry(
3471                                         (struct ext4_dir_entry_2 *)bh->b_data,
3472                                         inode->i_sb->s_blocksize);
3473                 return bh;
3474         }
3475
3476         *inlined = 1;
3477         return ext4_get_first_inline_block(inode, parent_de, retval);
3478 }
3479
3480 struct ext4_renament {
3481         struct inode *dir;
3482         struct dentry *dentry;
3483         struct inode *inode;
3484         bool is_dir;
3485         int dir_nlink_delta;
3486
3487         /* entry for "dentry" */
3488         struct buffer_head *bh;
3489         struct ext4_dir_entry_2 *de;
3490         int inlined;
3491
3492         /* entry for ".." in inode if it's a directory */
3493         struct buffer_head *dir_bh;
3494         struct ext4_dir_entry_2 *parent_de;
3495         int dir_inlined;
3496 };
3497
3498 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3499 {
3500         int retval;
3501
3502         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3503                                               &retval, &ent->parent_de,
3504                                               &ent->dir_inlined);
3505         if (!ent->dir_bh)
3506                 return retval;
3507         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3508                 return -EFSCORRUPTED;
3509         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3510         return ext4_journal_get_write_access(handle, ent->dir_bh);
3511 }
3512
3513 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3514                                   unsigned dir_ino)
3515 {
3516         int retval;
3517
3518         ent->parent_de->inode = cpu_to_le32(dir_ino);
3519         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3520         if (!ent->dir_inlined) {
3521                 if (is_dx(ent->inode)) {
3522                         retval = ext4_handle_dirty_dx_node(handle,
3523                                                            ent->inode,
3524                                                            ent->dir_bh);
3525                 } else {
3526                         retval = ext4_handle_dirty_dirblock(handle, ent->inode,
3527                                                             ent->dir_bh);
3528                 }
3529         } else {
3530                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3531         }
3532         if (retval) {
3533                 ext4_std_error(ent->dir->i_sb, retval);
3534                 return retval;
3535         }
3536         return 0;
3537 }
3538
3539 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3540                        unsigned ino, unsigned file_type)
3541 {
3542         int retval, retval2;
3543
3544         BUFFER_TRACE(ent->bh, "get write access");
3545         retval = ext4_journal_get_write_access(handle, ent->bh);
3546         if (retval)
3547                 return retval;
3548         ent->de->inode = cpu_to_le32(ino);
3549         if (ext4_has_feature_filetype(ent->dir->i_sb))
3550                 ent->de->file_type = file_type;
3551         inode_inc_iversion(ent->dir);
3552         ent->dir->i_ctime = ent->dir->i_mtime =
3553                 current_time(ent->dir);
3554         retval = ext4_mark_inode_dirty(handle, ent->dir);
3555         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3556         if (!ent->inlined) {
3557                 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh);
3558                 if (unlikely(retval2)) {
3559                         ext4_std_error(ent->dir->i_sb, retval2);
3560                         return retval2;
3561                 }
3562         }
3563         brelse(ent->bh);
3564         ent->bh = NULL;
3565
3566         return retval;
3567 }
3568
3569 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3570                                   const struct qstr *d_name)
3571 {
3572         int retval = -ENOENT;
3573         struct buffer_head *bh;
3574         struct ext4_dir_entry_2 *de;
3575
3576         bh = ext4_find_entry(dir, d_name, &de, NULL);
3577         if (IS_ERR(bh))
3578                 return PTR_ERR(bh);
3579         if (bh) {
3580                 retval = ext4_delete_entry(handle, dir, de, bh);
3581                 brelse(bh);
3582         }
3583         return retval;
3584 }
3585
3586 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3587                                int force_reread)
3588 {
3589         int retval;
3590         /*
3591          * ent->de could have moved from under us during htree split, so make
3592          * sure that we are deleting the right entry.  We might also be pointing
3593          * to a stale entry in the unused part of ent->bh so just checking inum
3594          * and the name isn't enough.
3595          */
3596         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3597             ent->de->name_len != ent->dentry->d_name.len ||
3598             strncmp(ent->de->name, ent->dentry->d_name.name,
3599                     ent->de->name_len) ||
3600             force_reread) {
3601                 retval = ext4_find_delete_entry(handle, ent->dir,
3602                                                 &ent->dentry->d_name);
3603         } else {
3604                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3605                 if (retval == -ENOENT) {
3606                         retval = ext4_find_delete_entry(handle, ent->dir,
3607                                                         &ent->dentry->d_name);
3608                 }
3609         }
3610
3611         if (retval) {
3612                 ext4_warning_inode(ent->dir,
3613                                    "Deleting old file: nlink %d, error=%d",
3614                                    ent->dir->i_nlink, retval);
3615         }
3616 }
3617
3618 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3619 {
3620         if (ent->dir_nlink_delta) {
3621                 if (ent->dir_nlink_delta == -1)
3622                         ext4_dec_count(handle, ent->dir);
3623                 else
3624                         ext4_inc_count(handle, ent->dir);
3625                 ext4_mark_inode_dirty(handle, ent->dir);
3626         }
3627 }
3628
3629 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3630                                               int credits, handle_t **h)
3631 {
3632         struct inode *wh;
3633         handle_t *handle;
3634         int retries = 0;
3635
3636         /*
3637          * for inode block, sb block, group summaries,
3638          * and inode bitmap
3639          */
3640         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3641                     EXT4_XATTR_TRANS_BLOCKS + 4);
3642 retry:
3643         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3644                                          &ent->dentry->d_name, 0, NULL,
3645                                          EXT4_HT_DIR, credits);
3646
3647         handle = ext4_journal_current_handle();
3648         if (IS_ERR(wh)) {
3649                 if (handle)
3650                         ext4_journal_stop(handle);
3651                 if (PTR_ERR(wh) == -ENOSPC &&
3652                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3653                         goto retry;
3654         } else {
3655                 *h = handle;
3656                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3657                 wh->i_op = &ext4_special_inode_operations;
3658         }
3659         return wh;
3660 }
3661
3662 /*
3663  * Anybody can rename anything with this: the permission checks are left to the
3664  * higher-level routines.
3665  *
3666  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3667  * while new_{dentry,inode) refers to the destination dentry/inode
3668  * This comes from rename(const char *oldpath, const char *newpath)
3669  */
3670 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3671                        struct inode *new_dir, struct dentry *new_dentry,
3672                        unsigned int flags)
3673 {
3674         handle_t *handle = NULL;
3675         struct ext4_renament old = {
3676                 .dir = old_dir,
3677                 .dentry = old_dentry,
3678                 .inode = d_inode(old_dentry),
3679         };
3680         struct ext4_renament new = {
3681                 .dir = new_dir,
3682                 .dentry = new_dentry,
3683                 .inode = d_inode(new_dentry),
3684         };
3685         int force_reread;
3686         int retval;
3687         struct inode *whiteout = NULL;
3688         int credits;
3689         u8 old_file_type;
3690
3691         if (new.inode && new.inode->i_nlink == 0) {
3692                 EXT4_ERROR_INODE(new.inode,
3693                                  "target of rename is already freed");
3694                 return -EFSCORRUPTED;
3695         }
3696
3697         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3698             (!projid_eq(EXT4_I(new_dir)->i_projid,
3699                         EXT4_I(old_dentry->d_inode)->i_projid)))
3700                 return -EXDEV;
3701
3702         retval = dquot_initialize(old.dir);
3703         if (retval)
3704                 return retval;
3705         retval = dquot_initialize(new.dir);
3706         if (retval)
3707                 return retval;
3708
3709         /* Initialize quotas before so that eventual writes go
3710          * in separate transaction */
3711         if (new.inode) {
3712                 retval = dquot_initialize(new.inode);
3713                 if (retval)
3714                         return retval;
3715         }
3716
3717         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3718         if (IS_ERR(old.bh))
3719                 return PTR_ERR(old.bh);
3720         /*
3721          *  Check for inode number is _not_ due to possible IO errors.
3722          *  We might rmdir the source, keep it as pwd of some process
3723          *  and merrily kill the link to whatever was created under the
3724          *  same name. Goodbye sticky bit ;-<
3725          */
3726         retval = -ENOENT;
3727         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3728                 goto end_rename;
3729
3730         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3731                                  &new.de, &new.inlined);
3732         if (IS_ERR(new.bh)) {
3733                 retval = PTR_ERR(new.bh);
3734                 new.bh = NULL;
3735                 goto end_rename;
3736         }
3737         if (new.bh) {
3738                 if (!new.inode) {
3739                         brelse(new.bh);
3740                         new.bh = NULL;
3741                 }
3742         }
3743         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3744                 ext4_alloc_da_blocks(old.inode);
3745
3746         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3747                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3748         if (!(flags & RENAME_WHITEOUT)) {
3749                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3750                 if (IS_ERR(handle)) {
3751                         retval = PTR_ERR(handle);
3752                         handle = NULL;
3753                         goto end_rename;
3754                 }
3755         } else {
3756                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3757                 if (IS_ERR(whiteout)) {
3758                         retval = PTR_ERR(whiteout);
3759                         whiteout = NULL;
3760                         goto end_rename;
3761                 }
3762         }
3763
3764         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3765                 ext4_handle_sync(handle);
3766
3767         if (S_ISDIR(old.inode->i_mode)) {
3768                 if (new.inode) {
3769                         retval = -ENOTEMPTY;
3770                         if (!ext4_empty_dir(new.inode))
3771                                 goto end_rename;
3772                 } else {
3773                         retval = -EMLINK;
3774                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3775                                 goto end_rename;
3776                 }
3777                 retval = ext4_rename_dir_prepare(handle, &old);
3778                 if (retval)
3779                         goto end_rename;
3780         }
3781         /*
3782          * If we're renaming a file within an inline_data dir and adding or
3783          * setting the new dirent causes a conversion from inline_data to
3784          * extents/blockmap, we need to force the dirent delete code to
3785          * re-read the directory, or else we end up trying to delete a dirent
3786          * from what is now the extent tree root (or a block map).
3787          */
3788         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3789                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3790
3791         old_file_type = old.de->file_type;
3792         if (whiteout) {
3793                 /*
3794                  * Do this before adding a new entry, so the old entry is sure
3795                  * to be still pointing to the valid old entry.
3796                  */
3797                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3798                                      EXT4_FT_CHRDEV);
3799                 if (retval)
3800                         goto end_rename;
3801                 retval = ext4_mark_inode_dirty(handle, whiteout);
3802                 if (unlikely(retval))
3803                         goto end_rename;
3804         }
3805         if (!new.bh) {
3806                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3807                 if (retval)
3808                         goto end_rename;
3809         } else {
3810                 retval = ext4_setent(handle, &new,
3811                                      old.inode->i_ino, old_file_type);
3812                 if (retval)
3813                         goto end_rename;
3814         }
3815         if (force_reread)
3816                 force_reread = !ext4_test_inode_flag(new.dir,
3817                                                      EXT4_INODE_INLINE_DATA);
3818
3819         /*
3820          * Like most other Unix systems, set the ctime for inodes on a
3821          * rename.
3822          */
3823         old.inode->i_ctime = current_time(old.inode);
3824         retval = ext4_mark_inode_dirty(handle, old.inode);
3825         if (unlikely(retval))
3826                 goto end_rename;
3827
3828         if (!whiteout) {
3829                 /*
3830                  * ok, that's it
3831                  */
3832                 ext4_rename_delete(handle, &old, force_reread);
3833         }
3834
3835         if (new.inode) {
3836                 ext4_dec_count(handle, new.inode);
3837                 new.inode->i_ctime = current_time(new.inode);
3838         }
3839         old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
3840         ext4_update_dx_flag(old.dir);
3841         if (old.dir_bh) {
3842                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3843                 if (retval)
3844                         goto end_rename;
3845
3846                 ext4_dec_count(handle, old.dir);
3847                 if (new.inode) {
3848                         /* checked ext4_empty_dir above, can't have another
3849                          * parent, ext4_dec_count() won't work for many-linked
3850                          * dirs */
3851                         clear_nlink(new.inode);
3852                 } else {
3853                         ext4_inc_count(handle, new.dir);
3854                         ext4_update_dx_flag(new.dir);
3855                         retval = ext4_mark_inode_dirty(handle, new.dir);
3856                         if (unlikely(retval))
3857                                 goto end_rename;
3858                 }
3859         }
3860         retval = ext4_mark_inode_dirty(handle, old.dir);
3861         if (unlikely(retval))
3862                 goto end_rename;
3863         if (new.inode) {
3864                 retval = ext4_mark_inode_dirty(handle, new.inode);
3865                 if (unlikely(retval))
3866                         goto end_rename;
3867                 if (!new.inode->i_nlink)
3868                         ext4_orphan_add(handle, new.inode);
3869         }
3870         retval = 0;
3871
3872 end_rename:
3873         brelse(old.dir_bh);
3874         brelse(old.bh);
3875         brelse(new.bh);
3876         if (whiteout) {
3877                 if (retval)
3878                         drop_nlink(whiteout);
3879                 unlock_new_inode(whiteout);
3880                 iput(whiteout);
3881         }
3882         if (handle)
3883                 ext4_journal_stop(handle);
3884         return retval;
3885 }
3886
3887 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3888                              struct inode *new_dir, struct dentry *new_dentry)
3889 {
3890         handle_t *handle = NULL;
3891         struct ext4_renament old = {
3892                 .dir = old_dir,
3893                 .dentry = old_dentry,
3894                 .inode = d_inode(old_dentry),
3895         };
3896         struct ext4_renament new = {
3897                 .dir = new_dir,
3898                 .dentry = new_dentry,
3899                 .inode = d_inode(new_dentry),
3900         };
3901         u8 new_file_type;
3902         int retval;
3903         struct timespec64 ctime;
3904
3905         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3906              !projid_eq(EXT4_I(new_dir)->i_projid,
3907                         EXT4_I(old_dentry->d_inode)->i_projid)) ||
3908             (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3909              !projid_eq(EXT4_I(old_dir)->i_projid,
3910                         EXT4_I(new_dentry->d_inode)->i_projid)))
3911                 return -EXDEV;
3912
3913         retval = dquot_initialize(old.dir);
3914         if (retval)
3915                 return retval;
3916         retval = dquot_initialize(new.dir);
3917         if (retval)
3918                 return retval;
3919
3920         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3921                                  &old.de, &old.inlined);
3922         if (IS_ERR(old.bh))
3923                 return PTR_ERR(old.bh);
3924         /*
3925          *  Check for inode number is _not_ due to possible IO errors.
3926          *  We might rmdir the source, keep it as pwd of some process
3927          *  and merrily kill the link to whatever was created under the
3928          *  same name. Goodbye sticky bit ;-<
3929          */
3930         retval = -ENOENT;
3931         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3932                 goto end_rename;
3933
3934         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3935                                  &new.de, &new.inlined);
3936         if (IS_ERR(new.bh)) {
3937                 retval = PTR_ERR(new.bh);
3938                 new.bh = NULL;
3939                 goto end_rename;
3940         }
3941
3942         /* RENAME_EXCHANGE case: old *and* new must both exist */
3943         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3944                 goto end_rename;
3945
3946         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3947                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3948                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3949         if (IS_ERR(handle)) {
3950                 retval = PTR_ERR(handle);
3951                 handle = NULL;
3952                 goto end_rename;
3953         }
3954
3955         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3956                 ext4_handle_sync(handle);
3957
3958         if (S_ISDIR(old.inode->i_mode)) {
3959                 old.is_dir = true;
3960                 retval = ext4_rename_dir_prepare(handle, &old);
3961                 if (retval)
3962                         goto end_rename;
3963         }
3964         if (S_ISDIR(new.inode->i_mode)) {
3965                 new.is_dir = true;
3966                 retval = ext4_rename_dir_prepare(handle, &new);
3967                 if (retval)
3968                         goto end_rename;
3969         }
3970
3971         /*
3972          * Other than the special case of overwriting a directory, parents'
3973          * nlink only needs to be modified if this is a cross directory rename.
3974          */
3975         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3976                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3977                 new.dir_nlink_delta = -old.dir_nlink_delta;
3978                 retval = -EMLINK;
3979                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3980                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3981                         goto end_rename;
3982         }
3983
3984         new_file_type = new.de->file_type;
3985         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3986         if (retval)
3987                 goto end_rename;
3988
3989         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3990         if (retval)
3991                 goto end_rename;
3992
3993         /*
3994          * Like most other Unix systems, set the ctime for inodes on a
3995          * rename.
3996          */
3997         ctime = current_time(old.inode);
3998         old.inode->i_ctime = ctime;
3999         new.inode->i_ctime = ctime;
4000         retval = ext4_mark_inode_dirty(handle, old.inode);
4001         if (unlikely(retval))
4002                 goto end_rename;
4003         retval = ext4_mark_inode_dirty(handle, new.inode);
4004         if (unlikely(retval))
4005                 goto end_rename;
4006
4007         if (old.dir_bh) {
4008                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
4009                 if (retval)
4010                         goto end_rename;
4011         }
4012         if (new.dir_bh) {
4013                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
4014                 if (retval)
4015                         goto end_rename;
4016         }
4017         ext4_update_dir_count(handle, &old);
4018         ext4_update_dir_count(handle, &new);
4019         retval = 0;
4020
4021 end_rename:
4022         brelse(old.dir_bh);
4023         brelse(new.dir_bh);
4024         brelse(old.bh);
4025         brelse(new.bh);
4026         if (handle)
4027                 ext4_journal_stop(handle);
4028         return retval;
4029 }
4030
4031 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
4032                         struct inode *new_dir, struct dentry *new_dentry,
4033                         unsigned int flags)
4034 {
4035         int err;
4036
4037         if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
4038                 return -EIO;
4039
4040         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
4041                 return -EINVAL;
4042
4043         err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
4044                                      flags);
4045         if (err)
4046                 return err;
4047
4048         if (flags & RENAME_EXCHANGE) {
4049                 return ext4_cross_rename(old_dir, old_dentry,
4050                                          new_dir, new_dentry);
4051         }
4052
4053         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
4054 }
4055
4056 /*
4057  * directories can handle most operations...
4058  */
4059 const struct inode_operations ext4_dir_inode_operations = {
4060         .create         = ext4_create,
4061         .lookup         = ext4_lookup,
4062         .link           = ext4_link,
4063         .unlink         = ext4_unlink,
4064         .symlink        = ext4_symlink,
4065         .mkdir          = ext4_mkdir,
4066         .rmdir          = ext4_rmdir,
4067         .mknod          = ext4_mknod,
4068         .tmpfile        = ext4_tmpfile,
4069         .rename         = ext4_rename2,
4070         .setattr        = ext4_setattr,
4071         .getattr        = ext4_getattr,
4072         .listxattr      = ext4_listxattr,
4073         .get_acl        = ext4_get_acl,
4074         .set_acl        = ext4_set_acl,
4075         .fiemap         = ext4_fiemap,
4076 };
4077
4078 const struct inode_operations ext4_special_inode_operations = {
4079         .setattr        = ext4_setattr,
4080         .getattr        = ext4_getattr,
4081         .listxattr      = ext4_listxattr,
4082         .get_acl        = ext4_get_acl,
4083         .set_acl        = ext4_set_acl,
4084 };