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 (card@masi.ibp.fr)
   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 (davem@caip.rutgers.edu), 1995
  18  *  Directory entry file type support and forward compatibility hooks
  19  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 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;
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         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 0;
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                 ext4_mark_inode_dirty(handle, dir);
2227         }
2228         blocks = dir->i_size >> sb->s_blocksize_bits;
2229         for (block = 0; block < blocks; block++) {
2230                 bh = ext4_read_dirblock(dir, block, DIRENT);
2231                 if (bh == NULL) {
2232                         bh = ext4_bread(handle, dir, block,
2233                                         EXT4_GET_BLOCKS_CREATE);
2234                         goto add_to_new_block;
2235                 }
2236                 if (IS_ERR(bh)) {
2237                         retval = PTR_ERR(bh);
2238                         bh = NULL;
2239                         goto out;
2240                 }
2241                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2242                                            NULL, bh);
2243                 if (retval != -ENOSPC)
2244                         goto out;
2245
2246                 if (blocks == 1 && !dx_fallback &&
2247                     ext4_has_feature_dir_index(sb)) {
2248                         retval = make_indexed_dir(handle, &fname, dir,
2249                                                   inode, bh);
2250                         bh = NULL; /* make_indexed_dir releases bh */
2251                         goto out;
2252                 }
2253                 brelse(bh);
2254         }
2255         bh = ext4_append(handle, dir, &block);
2256 add_to_new_block:
2257         if (IS_ERR(bh)) {
2258                 retval = PTR_ERR(bh);
2259                 bh = NULL;
2260                 goto out;
2261         }
2262         de = (struct ext4_dir_entry_2 *) bh->b_data;
2263         de->inode = 0;
2264         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2265
2266         if (csum_size)
2267                 ext4_initialize_dirent_tail(bh, blocksize);
2268
2269         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2270 out:
2271         ext4_fname_free_filename(&fname);
2272         brelse(bh);
2273         if (retval == 0)
2274                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2275         return retval;
2276 }
2277
2278 /*
2279  * Returns 0 for success, or a negative error value
2280  */
2281 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2282                              struct inode *dir, struct inode *inode)
2283 {
2284         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2285         struct dx_entry *entries, *at;
2286         struct buffer_head *bh;
2287         struct super_block *sb = dir->i_sb;
2288         struct ext4_dir_entry_2 *de;
2289         int restart;
2290         int err;
2291
2292 again:
2293         restart = 0;
2294         frame = dx_probe(fname, dir, NULL, frames);
2295         if (IS_ERR(frame))
2296                 return PTR_ERR(frame);
2297         entries = frame->entries;
2298         at = frame->at;
2299         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
2300         if (IS_ERR(bh)) {
2301                 err = PTR_ERR(bh);
2302                 bh = NULL;
2303                 goto cleanup;
2304         }
2305
2306         BUFFER_TRACE(bh, "get_write_access");
2307         err = ext4_journal_get_write_access(handle, bh);
2308         if (err)
2309                 goto journal_error;
2310
2311         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2312         if (err != -ENOSPC)
2313                 goto cleanup;
2314
2315         err = 0;
2316         /* Block full, should compress but for now just split */
2317         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2318                        dx_get_count(entries), dx_get_limit(entries)));
2319         /* Need to split index? */
2320         if (dx_get_count(entries) == dx_get_limit(entries)) {
2321                 ext4_lblk_t newblock;
2322                 int levels = frame - frames + 1;
2323                 unsigned int icount;
2324                 int add_level = 1;
2325                 struct dx_entry *entries2;
2326                 struct dx_node *node2;
2327                 struct buffer_head *bh2;
2328
2329                 while (frame > frames) {
2330                         if (dx_get_count((frame - 1)->entries) <
2331                             dx_get_limit((frame - 1)->entries)) {
2332                                 add_level = 0;
2333                                 break;
2334                         }
2335                         frame--; /* split higher index block */
2336                         at = frame->at;
2337                         entries = frame->entries;
2338                         restart = 1;
2339                 }
2340                 if (add_level && levels == ext4_dir_htree_level(sb)) {
2341                         ext4_warning(sb, "Directory (ino: %lu) index full, "
2342                                          "reach max htree level :%d",
2343                                          dir->i_ino, levels);
2344                         if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2345                                 ext4_warning(sb, "Large directory feature is "
2346                                                  "not enabled on this "
2347                                                  "filesystem");
2348                         }
2349                         err = -ENOSPC;
2350                         goto cleanup;
2351                 }
2352                 icount = dx_get_count(entries);
2353                 bh2 = ext4_append(handle, dir, &newblock);
2354                 if (IS_ERR(bh2)) {
2355                         err = PTR_ERR(bh2);
2356                         goto cleanup;
2357                 }
2358                 node2 = (struct dx_node *)(bh2->b_data);
2359                 entries2 = node2->entries;
2360                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2361                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2362                                                            sb->s_blocksize);
2363                 BUFFER_TRACE(frame->bh, "get_write_access");
2364                 err = ext4_journal_get_write_access(handle, frame->bh);
2365                 if (err)
2366                         goto journal_error;
2367                 if (!add_level) {
2368                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2369                         unsigned hash2 = dx_get_hash(entries + icount1);
2370                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2371                                        icount1, icount2));
2372
2373                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2374                         err = ext4_journal_get_write_access(handle,
2375                                                              (frame - 1)->bh);
2376                         if (err)
2377                                 goto journal_error;
2378
2379                         memcpy((char *) entries2, (char *) (entries + icount1),
2380                                icount2 * sizeof(struct dx_entry));
2381                         dx_set_count(entries, icount1);
2382                         dx_set_count(entries2, icount2);
2383                         dx_set_limit(entries2, dx_node_limit(dir));
2384
2385                         /* Which index block gets the new entry? */
2386                         if (at - entries >= icount1) {
2387                                 frame->at = at = at - entries - icount1 + entries2;
2388                                 frame->entries = entries = entries2;
2389                                 swap(frame->bh, bh2);
2390                         }
2391                         dx_insert_block((frame - 1), hash2, newblock);
2392                         dxtrace(dx_show_index("node", frame->entries));
2393                         dxtrace(dx_show_index("node",
2394                                ((struct dx_node *) bh2->b_data)->entries));
2395                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2396                         if (err)
2397                                 goto journal_error;
2398                         brelse (bh2);
2399                         err = ext4_handle_dirty_dx_node(handle, dir,
2400                                                    (frame - 1)->bh);
2401                         if (err)
2402                                 goto journal_error;
2403                         if (restart) {
2404                                 err = ext4_handle_dirty_dx_node(handle, dir,
2405                                                            frame->bh);
2406                                 goto journal_error;
2407                         }
2408                 } else {
2409                         struct dx_root *dxroot;
2410                         memcpy((char *) entries2, (char *) entries,
2411                                icount * sizeof(struct dx_entry));
2412                         dx_set_limit(entries2, dx_node_limit(dir));
2413
2414                         /* Set up root */
2415                         dx_set_count(entries, 1);
2416                         dx_set_block(entries + 0, newblock);
2417                         dxroot = (struct dx_root *)frames[0].bh->b_data;
2418                         dxroot->info.indirect_levels += 1;
2419                         dxtrace(printk(KERN_DEBUG
2420                                        "Creating %d level index...\n",
2421                                        dxroot->info.indirect_levels));
2422                         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2423                         if (err)
2424                                 goto journal_error;
2425                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2426                         brelse(bh2);
2427                         restart = 1;
2428                         goto journal_error;
2429                 }
2430         }
2431         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2432         if (IS_ERR(de)) {
2433                 err = PTR_ERR(de);
2434                 goto cleanup;
2435         }
2436         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2437         goto cleanup;
2438
2439 journal_error:
2440         ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2441 cleanup:
2442         brelse(bh);
2443         dx_release(frames);
2444         /* @restart is true means htree-path has been changed, we need to
2445          * repeat dx_probe() to find out valid htree-path
2446          */
2447         if (restart && err == 0)
2448                 goto again;
2449         return err;
2450 }
2451
2452 /*
2453  * ext4_generic_delete_entry deletes a directory entry by merging it
2454  * with the previous entry
2455  */
2456 int ext4_generic_delete_entry(handle_t *handle,
2457                               struct inode *dir,
2458                               struct ext4_dir_entry_2 *de_del,
2459                               struct buffer_head *bh,
2460                               void *entry_buf,
2461                               int buf_size,
2462                               int csum_size)
2463 {
2464         struct ext4_dir_entry_2 *de, *pde;
2465         unsigned int blocksize = dir->i_sb->s_blocksize;
2466         int i;
2467
2468         i = 0;
2469         pde = NULL;
2470         de = (struct ext4_dir_entry_2 *)entry_buf;
2471         while (i < buf_size - csum_size) {
2472                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2473                                          bh->b_data, bh->b_size, i))
2474                         return -EFSCORRUPTED;
2475                 if (de == de_del)  {
2476                         if (pde)
2477                                 pde->rec_len = ext4_rec_len_to_disk(
2478                                         ext4_rec_len_from_disk(pde->rec_len,
2479                                                                blocksize) +
2480                                         ext4_rec_len_from_disk(de->rec_len,
2481                                                                blocksize),
2482                                         blocksize);
2483                         else
2484                                 de->inode = 0;
2485                         inode_inc_iversion(dir);
2486                         return 0;
2487                 }
2488                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2489                 pde = de;
2490                 de = ext4_next_entry(de, blocksize);
2491         }
2492         return -ENOENT;
2493 }
2494
2495 static int ext4_delete_entry(handle_t *handle,
2496                              struct inode *dir,
2497                              struct ext4_dir_entry_2 *de_del,
2498                              struct buffer_head *bh)
2499 {
2500         int err, csum_size = 0;
2501
2502         if (ext4_has_inline_data(dir)) {
2503                 int has_inline_data = 1;
2504                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2505                                                &has_inline_data);
2506                 if (has_inline_data)
2507                         return err;
2508         }
2509
2510         if (ext4_has_metadata_csum(dir->i_sb))
2511                 csum_size = sizeof(struct ext4_dir_entry_tail);
2512
2513         BUFFER_TRACE(bh, "get_write_access");
2514         err = ext4_journal_get_write_access(handle, bh);
2515         if (unlikely(err))
2516                 goto out;
2517
2518         err = ext4_generic_delete_entry(handle, dir, de_del,
2519                                         bh, bh->b_data,
2520                                         dir->i_sb->s_blocksize, csum_size);
2521         if (err)
2522                 goto out;
2523
2524         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2525         err = ext4_handle_dirty_dirblock(handle, dir, bh);
2526         if (unlikely(err))
2527                 goto out;
2528
2529         return 0;
2530 out:
2531         if (err != -ENOENT)
2532                 ext4_std_error(dir->i_sb, err);
2533         return err;
2534 }
2535
2536 /*
2537  * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2538  * since this indicates that nlinks count was previously 1 to avoid overflowing
2539  * the 16-bit i_links_count field on disk.  Directories with i_nlink == 1 mean
2540  * that subdirectory link counts are not being maintained accurately.
2541  *
2542  * The caller has already checked for i_nlink overflow in case the DIR_LINK
2543  * feature is not enabled and returned -EMLINK.  The is_dx() check is a proxy
2544  * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2545  * on regular files) and to avoid creating huge/slow non-HTREE directories.
2546  */
2547 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2548 {
2549         inc_nlink(inode);
2550         if (is_dx(inode) &&
2551             (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2552                 set_nlink(inode, 1);
2553 }
2554
2555 /*
2556  * If a directory had nlink == 1, then we should let it be 1. This indicates
2557  * directory has >EXT4_LINK_MAX subdirs.
2558  */
2559 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2560 {
2561         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2562                 drop_nlink(inode);
2563 }
2564
2565
2566 /*
2567  * Add non-directory inode to a directory. On success, the inode reference is
2568  * consumed by dentry is instantiation. This is also indicated by clearing of
2569  * *inodep pointer. On failure, the caller is responsible for dropping the
2570  * inode reference in the safe context.
2571  */
2572 static int ext4_add_nondir(handle_t *handle,
2573                 struct dentry *dentry, struct inode **inodep)
2574 {
2575         struct inode *dir = d_inode(dentry->d_parent);
2576         struct inode *inode = *inodep;
2577         int err = ext4_add_entry(handle, dentry, inode);
2578         if (!err) {
2579                 ext4_mark_inode_dirty(handle, inode);
2580                 if (IS_DIRSYNC(dir))
2581                         ext4_handle_sync(handle);
2582                 d_instantiate_new(dentry, inode);
2583                 *inodep = NULL;
2584                 return 0;
2585         }
2586         drop_nlink(inode);
2587         ext4_orphan_add(handle, inode);
2588         unlock_new_inode(inode);
2589         return err;
2590 }
2591
2592 /*
2593  * By the time this is called, we already have created
2594  * the directory cache entry for the new file, but it
2595  * is so far negative - it has no inode.
2596  *
2597  * If the create succeeds, we fill in the inode information
2598  * with d_instantiate().
2599  */
2600 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2601                        bool excl)
2602 {
2603         handle_t *handle;
2604         struct inode *inode;
2605         int err, credits, retries = 0;
2606
2607         err = dquot_initialize(dir);
2608         if (err)
2609                 return err;
2610
2611         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2612                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2613 retry:
2614         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2615                                             NULL, EXT4_HT_DIR, credits);
2616         handle = ext4_journal_current_handle();
2617         err = PTR_ERR(inode);
2618         if (!IS_ERR(inode)) {
2619                 inode->i_op = &ext4_file_inode_operations;
2620                 inode->i_fop = &ext4_file_operations;
2621                 ext4_set_aops(inode);
2622                 err = ext4_add_nondir(handle, dentry, &inode);
2623         }
2624         if (handle)
2625                 ext4_journal_stop(handle);
2626         if (!IS_ERR_OR_NULL(inode))
2627                 iput(inode);
2628         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2629                 goto retry;
2630         return err;
2631 }
2632
2633 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2634                       umode_t mode, dev_t rdev)
2635 {
2636         handle_t *handle;
2637         struct inode *inode;
2638         int err, credits, retries = 0;
2639
2640         err = dquot_initialize(dir);
2641         if (err)
2642                 return err;
2643
2644         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2645                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2646 retry:
2647         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2648                                             NULL, EXT4_HT_DIR, credits);
2649         handle = ext4_journal_current_handle();
2650         err = PTR_ERR(inode);
2651         if (!IS_ERR(inode)) {
2652                 init_special_inode(inode, inode->i_mode, rdev);
2653                 inode->i_op = &ext4_special_inode_operations;
2654                 err = ext4_add_nondir(handle, dentry, &inode);
2655         }
2656         if (handle)
2657                 ext4_journal_stop(handle);
2658         if (!IS_ERR_OR_NULL(inode))
2659                 iput(inode);
2660         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2661                 goto retry;
2662         return err;
2663 }
2664
2665 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2666 {
2667         handle_t *handle;
2668         struct inode *inode;
2669         int err, retries = 0;
2670
2671         err = dquot_initialize(dir);
2672         if (err)
2673                 return err;
2674
2675 retry:
2676         inode = ext4_new_inode_start_handle(dir, mode,
2677                                             NULL, 0, NULL,
2678                                             EXT4_HT_DIR,
2679                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2680                           4 + EXT4_XATTR_TRANS_BLOCKS);
2681         handle = ext4_journal_current_handle();
2682         err = PTR_ERR(inode);
2683         if (!IS_ERR(inode)) {
2684                 inode->i_op = &ext4_file_inode_operations;
2685                 inode->i_fop = &ext4_file_operations;
2686                 ext4_set_aops(inode);
2687                 d_tmpfile(dentry, inode);
2688                 err = ext4_orphan_add(handle, inode);
2689                 if (err)
2690                         goto err_unlock_inode;
2691                 mark_inode_dirty(inode);
2692                 unlock_new_inode(inode);
2693         }
2694         if (handle)
2695                 ext4_journal_stop(handle);
2696         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2697                 goto retry;
2698         return err;
2699 err_unlock_inode:
2700         ext4_journal_stop(handle);
2701         unlock_new_inode(inode);
2702         return err;
2703 }
2704
2705 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2706                           struct ext4_dir_entry_2 *de,
2707                           int blocksize, int csum_size,
2708                           unsigned int parent_ino, int dotdot_real_len)
2709 {
2710         de->inode = cpu_to_le32(inode->i_ino);
2711         de->name_len = 1;
2712         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2713                                            blocksize);
2714         strcpy(de->name, ".");
2715         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2716
2717         de = ext4_next_entry(de, blocksize);
2718         de->inode = cpu_to_le32(parent_ino);
2719         de->name_len = 2;
2720         if (!dotdot_real_len)
2721                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2722                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2723                                         blocksize);
2724         else
2725                 de->rec_len = ext4_rec_len_to_disk(
2726                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2727         strcpy(de->name, "..");
2728         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2729
2730         return ext4_next_entry(de, blocksize);
2731 }
2732
2733 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2734                              struct inode *inode)
2735 {
2736         struct buffer_head *dir_block = NULL;
2737         struct ext4_dir_entry_2 *de;
2738         ext4_lblk_t block = 0;
2739         unsigned int blocksize = dir->i_sb->s_blocksize;
2740         int csum_size = 0;
2741         int err;
2742
2743         if (ext4_has_metadata_csum(dir->i_sb))
2744                 csum_size = sizeof(struct ext4_dir_entry_tail);
2745
2746         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2747                 err = ext4_try_create_inline_dir(handle, dir, inode);
2748                 if (err < 0 && err != -ENOSPC)
2749                         goto out;
2750                 if (!err)
2751                         goto out;
2752         }
2753
2754         inode->i_size = 0;
2755         dir_block = ext4_append(handle, inode, &block);
2756         if (IS_ERR(dir_block))
2757                 return PTR_ERR(dir_block);
2758         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2759         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2760         set_nlink(inode, 2);
2761         if (csum_size)
2762                 ext4_initialize_dirent_tail(dir_block, blocksize);
2763
2764         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2765         err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
2766         if (err)
2767                 goto out;
2768         set_buffer_verified(dir_block);
2769 out:
2770         brelse(dir_block);
2771         return err;
2772 }
2773
2774 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2775 {
2776         handle_t *handle;
2777         struct inode *inode;
2778         int err, credits, retries = 0;
2779
2780         if (EXT4_DIR_LINK_MAX(dir))
2781                 return -EMLINK;
2782
2783         err = dquot_initialize(dir);
2784         if (err)
2785                 return err;
2786
2787         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2788                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2789 retry:
2790         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2791                                             &dentry->d_name,
2792                                             0, NULL, EXT4_HT_DIR, credits);
2793         handle = ext4_journal_current_handle();
2794         err = PTR_ERR(inode);
2795         if (IS_ERR(inode))
2796                 goto out_stop;
2797
2798         inode->i_op = &ext4_dir_inode_operations;
2799         inode->i_fop = &ext4_dir_operations;
2800         err = ext4_init_new_dir(handle, dir, inode);
2801         if (err)
2802                 goto out_clear_inode;
2803         err = ext4_mark_inode_dirty(handle, inode);
2804         if (!err)
2805                 err = ext4_add_entry(handle, dentry, inode);
2806         if (err) {
2807 out_clear_inode:
2808                 clear_nlink(inode);
2809                 ext4_orphan_add(handle, inode);
2810                 unlock_new_inode(inode);
2811                 ext4_mark_inode_dirty(handle, inode);
2812                 ext4_journal_stop(handle);
2813                 iput(inode);
2814                 goto out_retry;
2815         }
2816         ext4_inc_count(handle, dir);
2817         ext4_update_dx_flag(dir);
2818         err = ext4_mark_inode_dirty(handle, dir);
2819         if (err)
2820                 goto out_clear_inode;
2821         d_instantiate_new(dentry, inode);
2822         if (IS_DIRSYNC(dir))
2823                 ext4_handle_sync(handle);
2824
2825 out_stop:
2826         if (handle)
2827                 ext4_journal_stop(handle);
2828 out_retry:
2829         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2830                 goto retry;
2831         return err;
2832 }
2833
2834 /*
2835  * routine to check that the specified directory is empty (for rmdir)
2836  */
2837 bool ext4_empty_dir(struct inode *inode)
2838 {
2839         unsigned int offset;
2840         struct buffer_head *bh;
2841         struct ext4_dir_entry_2 *de;
2842         struct super_block *sb;
2843
2844         if (ext4_has_inline_data(inode)) {
2845                 int has_inline_data = 1;
2846                 int ret;
2847
2848                 ret = empty_inline_dir(inode, &has_inline_data);
2849                 if (has_inline_data)
2850                         return ret;
2851         }
2852
2853         sb = inode->i_sb;
2854         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2855                 EXT4_ERROR_INODE(inode, "invalid size");
2856                 return true;
2857         }
2858         /* The first directory block must not be a hole,
2859          * so treat it as DIRENT_HTREE
2860          */
2861         bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
2862         if (IS_ERR(bh))
2863                 return true;
2864
2865         de = (struct ext4_dir_entry_2 *) bh->b_data;
2866         if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
2867                                  0) ||
2868             le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
2869                 ext4_warning_inode(inode, "directory missing '.'");
2870                 brelse(bh);
2871                 return true;
2872         }
2873         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2874         de = ext4_next_entry(de, sb->s_blocksize);
2875         if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
2876                                  offset) ||
2877             le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
2878                 ext4_warning_inode(inode, "directory missing '..'");
2879                 brelse(bh);
2880                 return true;
2881         }
2882         offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2883         while (offset < inode->i_size) {
2884                 if (!(offset & (sb->s_blocksize - 1))) {
2885                         unsigned int lblock;
2886                         brelse(bh);
2887                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2888                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2889                         if (bh == NULL) {
2890                                 offset += sb->s_blocksize;
2891                                 continue;
2892                         }
2893                         if (IS_ERR(bh))
2894                                 return true;
2895                 }
2896                 de = (struct ext4_dir_entry_2 *) (bh->b_data +
2897                                         (offset & (sb->s_blocksize - 1)));
2898                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2899                                          bh->b_data, bh->b_size, offset)) {
2900                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2901                         continue;
2902                 }
2903                 if (le32_to_cpu(de->inode)) {
2904                         brelse(bh);
2905                         return false;
2906                 }
2907                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2908         }
2909         brelse(bh);
2910         return true;
2911 }
2912
2913 /*
2914  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2915  * such inodes, starting at the superblock, in case we crash before the
2916  * file is closed/deleted, or in case the inode truncate spans multiple
2917  * transactions and the last transaction is not recovered after a crash.
2918  *
2919  * At filesystem recovery time, we walk this list deleting unlinked
2920  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2921  *
2922  * Orphan list manipulation functions must be called under i_mutex unless
2923  * we are just creating the inode or deleting it.
2924  */
2925 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2926 {
2927         struct super_block *sb = inode->i_sb;
2928         struct ext4_sb_info *sbi = EXT4_SB(sb);
2929         struct ext4_iloc iloc;
2930         int err = 0, rc;
2931         bool dirty = false;
2932
2933         if (!sbi->s_journal || is_bad_inode(inode))
2934                 return 0;
2935
2936         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2937                      !inode_is_locked(inode));
2938         /*
2939          * Exit early if inode already is on orphan list. This is a big speedup
2940          * since we don't have to contend on the global s_orphan_lock.
2941          */
2942         if (!list_empty(&EXT4_I(inode)->i_orphan))
2943                 return 0;
2944
2945         /*
2946          * Orphan handling is only valid for files with data blocks
2947          * being truncated, or files being unlinked. Note that we either
2948          * hold i_mutex, or the inode can not be referenced from outside,
2949          * so i_nlink should not be bumped due to race
2950          */
2951         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2952                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2953
2954         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2955         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2956         if (err)
2957                 goto out;
2958
2959         err = ext4_reserve_inode_write(handle, inode, &iloc);
2960         if (err)
2961                 goto out;
2962
2963         mutex_lock(&sbi->s_orphan_lock);
2964         /*
2965          * Due to previous errors inode may be already a part of on-disk
2966          * orphan list. If so skip on-disk list modification.
2967          */
2968         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2969             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2970                 /* Insert this inode at the head of the on-disk orphan list */
2971                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2972                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2973                 dirty = true;
2974         }
2975         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2976         mutex_unlock(&sbi->s_orphan_lock);
2977
2978         if (dirty) {
2979                 err = ext4_handle_dirty_super(handle, sb);
2980                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2981                 if (!err)
2982                         err = rc;
2983                 if (err) {
2984                         /*
2985                          * We have to remove inode from in-memory list if
2986                          * addition to on disk orphan list failed. Stray orphan
2987                          * list entries can cause panics at unmount time.
2988                          */
2989                         mutex_lock(&sbi->s_orphan_lock);
2990                         list_del_init(&EXT4_I(inode)->i_orphan);
2991                         mutex_unlock(&sbi->s_orphan_lock);
2992                 }
2993         } else
2994                 brelse(iloc.bh);
2995
2996         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2997         jbd_debug(4, "orphan inode %lu will point to %d\n",
2998                         inode->i_ino, NEXT_ORPHAN(inode));
2999 out:
3000         ext4_std_error(sb, err);
3001         return err;
3002 }
3003
3004 /*
3005  * ext4_orphan_del() removes an unlinked or truncated inode from the list
3006  * of such inodes stored on disk, because it is finally being cleaned up.
3007  */
3008 int ext4_orphan_del(handle_t *handle, struct inode *inode)
3009 {
3010         struct list_head *prev;
3011         struct ext4_inode_info *ei = EXT4_I(inode);
3012         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3013         __u32 ino_next;
3014         struct ext4_iloc iloc;
3015         int err = 0;
3016
3017         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
3018                 return 0;
3019
3020         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
3021                      !inode_is_locked(inode));
3022         /* Do this quick check before taking global s_orphan_lock. */
3023         if (list_empty(&ei->i_orphan))
3024                 return 0;
3025
3026         if (handle) {
3027                 /* Grab inode buffer early before taking global s_orphan_lock */
3028                 err = ext4_reserve_inode_write(handle, inode, &iloc);
3029         }
3030
3031         mutex_lock(&sbi->s_orphan_lock);
3032         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
3033
3034         prev = ei->i_orphan.prev;
3035         list_del_init(&ei->i_orphan);
3036
3037         /* If we're on an error path, we may not have a valid
3038          * transaction handle with which to update the orphan list on
3039          * disk, but we still need to remove the inode from the linked
3040          * list in memory. */
3041         if (!handle || err) {
3042                 mutex_unlock(&sbi->s_orphan_lock);
3043                 goto out_err;
3044         }
3045
3046         ino_next = NEXT_ORPHAN(inode);
3047         if (prev == &sbi->s_orphan) {
3048                 jbd_debug(4, "superblock will point to %u\n", ino_next);
3049                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
3050                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
3051                 if (err) {
3052                         mutex_unlock(&sbi->s_orphan_lock);
3053                         goto out_brelse;
3054                 }
3055                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
3056                 mutex_unlock(&sbi->s_orphan_lock);
3057                 err = ext4_handle_dirty_super(handle, inode->i_sb);
3058         } else {
3059                 struct ext4_iloc iloc2;
3060                 struct inode *i_prev =
3061                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
3062
3063                 jbd_debug(4, "orphan inode %lu will point to %u\n",
3064                           i_prev->i_ino, ino_next);
3065                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
3066                 if (err) {
3067                         mutex_unlock(&sbi->s_orphan_lock);
3068                         goto out_brelse;
3069                 }
3070                 NEXT_ORPHAN(i_prev) = ino_next;
3071                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
3072                 mutex_unlock(&sbi->s_orphan_lock);
3073         }
3074         if (err)
3075                 goto out_brelse;
3076         NEXT_ORPHAN(inode) = 0;
3077         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
3078 out_err:
3079         ext4_std_error(inode->i_sb, err);
3080         return err;
3081
3082 out_brelse:
3083         brelse(iloc.bh);
3084         goto out_err;
3085 }
3086
3087 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3088 {
3089         int retval;
3090         struct inode *inode;
3091         struct buffer_head *bh;
3092         struct ext4_dir_entry_2 *de;
3093         handle_t *handle = NULL;
3094
3095         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3096                 return -EIO;
3097
3098         /* Initialize quotas before so that eventual writes go in
3099          * separate transaction */
3100         retval = dquot_initialize(dir);
3101         if (retval)
3102                 return retval;
3103         retval = dquot_initialize(d_inode(dentry));
3104         if (retval)
3105                 return retval;
3106
3107         retval = -ENOENT;
3108         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3109         if (IS_ERR(bh))
3110                 return PTR_ERR(bh);
3111         if (!bh)
3112                 goto end_rmdir;
3113
3114         inode = d_inode(dentry);
3115
3116         retval = -EFSCORRUPTED;
3117         if (le32_to_cpu(de->inode) != inode->i_ino)
3118                 goto end_rmdir;
3119
3120         retval = -ENOTEMPTY;
3121         if (!ext4_empty_dir(inode))
3122                 goto end_rmdir;
3123
3124         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3125                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3126         if (IS_ERR(handle)) {
3127                 retval = PTR_ERR(handle);
3128                 handle = NULL;
3129                 goto end_rmdir;
3130         }
3131
3132         if (IS_DIRSYNC(dir))
3133                 ext4_handle_sync(handle);
3134
3135         retval = ext4_delete_entry(handle, dir, de, bh);
3136         if (retval)
3137                 goto end_rmdir;
3138         if (!EXT4_DIR_LINK_EMPTY(inode))
3139                 ext4_warning_inode(inode,
3140                              "empty directory '%.*s' has too many links (%u)",
3141                              dentry->d_name.len, dentry->d_name.name,
3142                              inode->i_nlink);
3143         inode_inc_iversion(inode);
3144         clear_nlink(inode);
3145         /* There's no need to set i_disksize: the fact that i_nlink is
3146          * zero will ensure that the right thing happens during any
3147          * recovery. */
3148         inode->i_size = 0;
3149         ext4_orphan_add(handle, inode);
3150         inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
3151         ext4_mark_inode_dirty(handle, inode);
3152         ext4_dec_count(handle, dir);
3153         ext4_update_dx_flag(dir);
3154         ext4_mark_inode_dirty(handle, dir);
3155
3156 #ifdef CONFIG_UNICODE
3157         /* VFS negative dentries are incompatible with Encoding and
3158          * Case-insensitiveness. Eventually we'll want avoid
3159          * invalidating the dentries here, alongside with returning the
3160          * negative dentries at ext4_lookup(), when it is better
3161          * supported by the VFS for the CI case.
3162          */
3163         if (IS_CASEFOLDED(dir))
3164                 d_invalidate(dentry);
3165 #endif
3166
3167 end_rmdir:
3168         brelse(bh);
3169         if (handle)
3170                 ext4_journal_stop(handle);
3171         return retval;
3172 }
3173
3174 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3175 {
3176         int retval;
3177         struct inode *inode;
3178         struct buffer_head *bh;
3179         struct ext4_dir_entry_2 *de;
3180         handle_t *handle = NULL;
3181
3182         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3183                 return -EIO;
3184
3185         trace_ext4_unlink_enter(dir, dentry);
3186         /* Initialize quotas before so that eventual writes go
3187          * in separate transaction */
3188         retval = dquot_initialize(dir);
3189         if (retval)
3190                 return retval;
3191         retval = dquot_initialize(d_inode(dentry));
3192         if (retval)
3193                 return retval;
3194
3195         retval = -ENOENT;
3196         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3197         if (IS_ERR(bh))
3198                 return PTR_ERR(bh);
3199         if (!bh)
3200                 goto end_unlink;
3201
3202         inode = d_inode(dentry);
3203
3204         retval = -EFSCORRUPTED;
3205         if (le32_to_cpu(de->inode) != inode->i_ino)
3206                 goto end_unlink;
3207
3208         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3209                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3210         if (IS_ERR(handle)) {
3211                 retval = PTR_ERR(handle);
3212                 handle = NULL;
3213                 goto end_unlink;
3214         }
3215
3216         if (IS_DIRSYNC(dir))
3217                 ext4_handle_sync(handle);
3218
3219         retval = ext4_delete_entry(handle, dir, de, bh);
3220         if (retval)
3221                 goto end_unlink;
3222         dir->i_ctime = dir->i_mtime = current_time(dir);
3223         ext4_update_dx_flag(dir);
3224         ext4_mark_inode_dirty(handle, dir);
3225         if (inode->i_nlink == 0)
3226                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3227                                    dentry->d_name.len, dentry->d_name.name);
3228         else
3229                 drop_nlink(inode);
3230         if (!inode->i_nlink)
3231                 ext4_orphan_add(handle, inode);
3232         inode->i_ctime = current_time(inode);
3233         ext4_mark_inode_dirty(handle, inode);
3234
3235 #ifdef CONFIG_UNICODE
3236         /* VFS negative dentries are incompatible with Encoding and
3237          * Case-insensitiveness. Eventually we'll want avoid
3238          * invalidating the dentries here, alongside with returning the
3239          * negative dentries at ext4_lookup(), when it is  better
3240          * supported by the VFS for the CI case.
3241          */
3242         if (IS_CASEFOLDED(dir))
3243                 d_invalidate(dentry);
3244 #endif
3245
3246 end_unlink:
3247         brelse(bh);
3248         if (handle)
3249                 ext4_journal_stop(handle);
3250         trace_ext4_unlink_exit(dentry, retval);
3251         return retval;
3252 }
3253
3254 static int ext4_symlink(struct inode *dir,
3255                         struct dentry *dentry, const char *symname)
3256 {
3257         handle_t *handle;
3258         struct inode *inode;
3259         int err, len = strlen(symname);
3260         int credits;
3261         struct fscrypt_str disk_link;
3262
3263         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3264                 return -EIO;
3265
3266         err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3267                                       &disk_link);
3268         if (err)
3269                 return err;
3270
3271         err = dquot_initialize(dir);
3272         if (err)
3273                 return err;
3274
3275         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3276                 /*
3277                  * For non-fast symlinks, we just allocate inode and put it on
3278                  * orphan list in the first transaction => we need bitmap,
3279                  * group descriptor, sb, inode block, quota blocks, and
3280                  * possibly selinux xattr blocks.
3281                  */
3282                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3283                           EXT4_XATTR_TRANS_BLOCKS;
3284         } else {
3285                 /*
3286                  * Fast symlink. We have to add entry to directory
3287                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3288                  * allocate new inode (bitmap, group descriptor, inode block,
3289                  * quota blocks, sb is already counted in previous macros).
3290                  */
3291                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3292                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3293         }
3294
3295         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3296                                             &dentry->d_name, 0, NULL,
3297                                             EXT4_HT_DIR, credits);
3298         handle = ext4_journal_current_handle();
3299         if (IS_ERR(inode)) {
3300                 if (handle)
3301                         ext4_journal_stop(handle);
3302                 return PTR_ERR(inode);
3303         }
3304
3305         if (IS_ENCRYPTED(inode)) {
3306                 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3307                 if (err)
3308                         goto err_drop_inode;
3309                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3310         }
3311
3312         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3313                 if (!IS_ENCRYPTED(inode))
3314                         inode->i_op = &ext4_symlink_inode_operations;
3315                 inode_nohighmem(inode);
3316                 ext4_set_aops(inode);
3317                 /*
3318                  * We cannot call page_symlink() with transaction started
3319                  * because it calls into ext4_write_begin() which can wait
3320                  * for transaction commit if we are running out of space
3321                  * and thus we deadlock. So we have to stop transaction now
3322                  * and restart it when symlink contents is written.
3323                  *
3324                  * To keep fs consistent in case of crash, we have to put inode
3325                  * to orphan list in the mean time.
3326                  */
3327                 drop_nlink(inode);
3328                 err = ext4_orphan_add(handle, inode);
3329                 ext4_journal_stop(handle);
3330                 handle = NULL;
3331                 if (err)
3332                         goto err_drop_inode;
3333                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3334                 if (err)
3335                         goto err_drop_inode;
3336                 /*
3337                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3338                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3339                  */
3340                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3341                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3342                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3343                 if (IS_ERR(handle)) {
3344                         err = PTR_ERR(handle);
3345                         handle = NULL;
3346                         goto err_drop_inode;
3347                 }
3348                 set_nlink(inode, 1);
3349                 err = ext4_orphan_del(handle, inode);
3350                 if (err)
3351                         goto err_drop_inode;
3352         } else {
3353                 /* clear the extent format for fast symlink */
3354                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3355                 if (!IS_ENCRYPTED(inode)) {
3356                         inode->i_op = &ext4_fast_symlink_inode_operations;
3357                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3358                 }
3359                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3360                        disk_link.len);
3361                 inode->i_size = disk_link.len - 1;
3362         }
3363         EXT4_I(inode)->i_disksize = inode->i_size;
3364         err = ext4_add_nondir(handle, dentry, &inode);
3365         if (handle)
3366                 ext4_journal_stop(handle);
3367         if (inode)
3368                 iput(inode);
3369         goto out_free_encrypted_link;
3370
3371 err_drop_inode:
3372         if (handle)
3373                 ext4_journal_stop(handle);
3374         clear_nlink(inode);
3375         unlock_new_inode(inode);
3376         iput(inode);
3377 out_free_encrypted_link:
3378         if (disk_link.name != (unsigned char *)symname)
3379                 kfree(disk_link.name);
3380         return err;
3381 }
3382
3383 static int ext4_link(struct dentry *old_dentry,
3384                      struct inode *dir, struct dentry *dentry)
3385 {
3386         handle_t *handle;
3387         struct inode *inode = d_inode(old_dentry);
3388         int err, retries = 0;
3389
3390         if (inode->i_nlink >= EXT4_LINK_MAX)
3391                 return -EMLINK;
3392
3393         err = fscrypt_prepare_link(old_dentry, dir, dentry);
3394         if (err)
3395                 return err;
3396
3397         if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3398             (!projid_eq(EXT4_I(dir)->i_projid,
3399                         EXT4_I(old_dentry->d_inode)->i_projid)))
3400                 return -EXDEV;
3401
3402         err = dquot_initialize(dir);
3403         if (err)
3404                 return err;
3405
3406 retry:
3407         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3408                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3409                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3410         if (IS_ERR(handle))
3411                 return PTR_ERR(handle);
3412
3413         if (IS_DIRSYNC(dir))
3414                 ext4_handle_sync(handle);
3415
3416         inode->i_ctime = current_time(inode);
3417         ext4_inc_count(handle, inode);
3418         ihold(inode);
3419
3420         err = ext4_add_entry(handle, dentry, inode);
3421         if (!err) {
3422                 ext4_mark_inode_dirty(handle, inode);
3423                 /* this can happen only for tmpfile being
3424                  * linked the first time
3425                  */
3426                 if (inode->i_nlink == 1)
3427                         ext4_orphan_del(handle, inode);
3428                 d_instantiate(dentry, inode);
3429         } else {
3430                 drop_nlink(inode);
3431                 iput(inode);
3432         }
3433         ext4_journal_stop(handle);
3434         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3435                 goto retry;
3436         return err;
3437 }
3438
3439
3440 /*
3441  * Try to find buffer head where contains the parent block.
3442  * It should be the inode block if it is inlined or the 1st block
3443  * if it is a normal dir.
3444  */
3445 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3446                                         struct inode *inode,
3447                                         int *retval,
3448                                         struct ext4_dir_entry_2 **parent_de,
3449                                         int *inlined)
3450 {
3451         struct buffer_head *bh;
3452
3453         if (!ext4_has_inline_data(inode)) {
3454                 /* The first directory block must not be a hole, so
3455                  * treat it as DIRENT_HTREE
3456                  */
3457                 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
3458                 if (IS_ERR(bh)) {
3459                         *retval = PTR_ERR(bh);
3460                         return NULL;
3461                 }
3462                 *parent_de = ext4_next_entry(
3463                                         (struct ext4_dir_entry_2 *)bh->b_data,
3464                                         inode->i_sb->s_blocksize);
3465                 return bh;
3466         }
3467
3468         *inlined = 1;
3469         return ext4_get_first_inline_block(inode, parent_de, retval);
3470 }
3471
3472 struct ext4_renament {
3473         struct inode *dir;
3474         struct dentry *dentry;
3475         struct inode *inode;
3476         bool is_dir;
3477         int dir_nlink_delta;
3478
3479         /* entry for "dentry" */
3480         struct buffer_head *bh;
3481         struct ext4_dir_entry_2 *de;
3482         int inlined;
3483
3484         /* entry for ".." in inode if it's a directory */
3485         struct buffer_head *dir_bh;
3486         struct ext4_dir_entry_2 *parent_de;
3487         int dir_inlined;
3488 };
3489
3490 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3491 {
3492         int retval;
3493
3494         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3495                                               &retval, &ent->parent_de,
3496                                               &ent->dir_inlined);
3497         if (!ent->dir_bh)
3498                 return retval;
3499         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3500                 return -EFSCORRUPTED;
3501         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3502         return ext4_journal_get_write_access(handle, ent->dir_bh);
3503 }
3504
3505 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3506                                   unsigned dir_ino)
3507 {
3508         int retval;
3509
3510         ent->parent_de->inode = cpu_to_le32(dir_ino);
3511         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3512         if (!ent->dir_inlined) {
3513                 if (is_dx(ent->inode)) {
3514                         retval = ext4_handle_dirty_dx_node(handle,
3515                                                            ent->inode,
3516                                                            ent->dir_bh);
3517                 } else {
3518                         retval = ext4_handle_dirty_dirblock(handle, ent->inode,
3519                                                             ent->dir_bh);
3520                 }
3521         } else {
3522                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3523         }
3524         if (retval) {
3525                 ext4_std_error(ent->dir->i_sb, retval);
3526                 return retval;
3527         }
3528         return 0;
3529 }
3530
3531 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3532                        unsigned ino, unsigned file_type)
3533 {
3534         int retval;
3535
3536         BUFFER_TRACE(ent->bh, "get write access");
3537         retval = ext4_journal_get_write_access(handle, ent->bh);
3538         if (retval)
3539                 return retval;
3540         ent->de->inode = cpu_to_le32(ino);
3541         if (ext4_has_feature_filetype(ent->dir->i_sb))
3542                 ent->de->file_type = file_type;
3543         inode_inc_iversion(ent->dir);
3544         ent->dir->i_ctime = ent->dir->i_mtime =
3545                 current_time(ent->dir);
3546         ext4_mark_inode_dirty(handle, ent->dir);
3547         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3548         if (!ent->inlined) {
3549                 retval = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh);
3550                 if (unlikely(retval)) {
3551                         ext4_std_error(ent->dir->i_sb, retval);
3552                         return retval;
3553                 }
3554         }
3555         brelse(ent->bh);
3556         ent->bh = NULL;
3557
3558         return 0;
3559 }
3560
3561 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3562                                   const struct qstr *d_name)
3563 {
3564         int retval = -ENOENT;
3565         struct buffer_head *bh;
3566         struct ext4_dir_entry_2 *de;
3567
3568         bh = ext4_find_entry(dir, d_name, &de, NULL);
3569         if (IS_ERR(bh))
3570                 return PTR_ERR(bh);
3571         if (bh) {
3572                 retval = ext4_delete_entry(handle, dir, de, bh);
3573                 brelse(bh);
3574         }
3575         return retval;
3576 }
3577
3578 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3579                                int force_reread)
3580 {
3581         int retval;
3582         /*
3583          * ent->de could have moved from under us during htree split, so make
3584          * sure that we are deleting the right entry.  We might also be pointing
3585          * to a stale entry in the unused part of ent->bh so just checking inum
3586          * and the name isn't enough.
3587          */
3588         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3589             ent->de->name_len != ent->dentry->d_name.len ||
3590             strncmp(ent->de->name, ent->dentry->d_name.name,
3591                     ent->de->name_len) ||
3592             force_reread) {
3593                 retval = ext4_find_delete_entry(handle, ent->dir,
3594                                                 &ent->dentry->d_name);
3595         } else {
3596                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3597                 if (retval == -ENOENT) {
3598                         retval = ext4_find_delete_entry(handle, ent->dir,
3599                                                         &ent->dentry->d_name);
3600                 }
3601         }
3602
3603         if (retval) {
3604                 ext4_warning_inode(ent->dir,
3605                                    "Deleting old file: nlink %d, error=%d",
3606                                    ent->dir->i_nlink, retval);
3607         }
3608 }
3609
3610 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3611 {
3612         if (ent->dir_nlink_delta) {
3613                 if (ent->dir_nlink_delta == -1)
3614                         ext4_dec_count(handle, ent->dir);
3615                 else
3616                         ext4_inc_count(handle, ent->dir);
3617                 ext4_mark_inode_dirty(handle, ent->dir);
3618         }
3619 }
3620
3621 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3622                                               int credits, handle_t **h)
3623 {
3624         struct inode *wh;
3625         handle_t *handle;
3626         int retries = 0;
3627
3628         /*
3629          * for inode block, sb block, group summaries,
3630          * and inode bitmap
3631          */
3632         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3633                     EXT4_XATTR_TRANS_BLOCKS + 4);
3634 retry:
3635         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3636                                          &ent->dentry->d_name, 0, NULL,
3637                                          EXT4_HT_DIR, credits);
3638
3639         handle = ext4_journal_current_handle();
3640         if (IS_ERR(wh)) {
3641                 if (handle)
3642                         ext4_journal_stop(handle);
3643                 if (PTR_ERR(wh) == -ENOSPC &&
3644                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3645                         goto retry;
3646         } else {
3647                 *h = handle;
3648                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3649                 wh->i_op = &ext4_special_inode_operations;
3650         }
3651         return wh;
3652 }
3653
3654 /*
3655  * Anybody can rename anything with this: the permission checks are left to the
3656  * higher-level routines.
3657  *
3658  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3659  * while new_{dentry,inode) refers to the destination dentry/inode
3660  * This comes from rename(const char *oldpath, const char *newpath)
3661  */
3662 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3663                        struct inode *new_dir, struct dentry *new_dentry,
3664                        unsigned int flags)
3665 {
3666         handle_t *handle = NULL;
3667         struct ext4_renament old = {
3668                 .dir = old_dir,
3669                 .dentry = old_dentry,
3670                 .inode = d_inode(old_dentry),
3671         };
3672         struct ext4_renament new = {
3673                 .dir = new_dir,
3674                 .dentry = new_dentry,
3675                 .inode = d_inode(new_dentry),
3676         };
3677         int force_reread;
3678         int retval;
3679         struct inode *whiteout = NULL;
3680         int credits;
3681         u8 old_file_type;
3682
3683         if (new.inode && new.inode->i_nlink == 0) {
3684                 EXT4_ERROR_INODE(new.inode,
3685                                  "target of rename is already freed");
3686                 return -EFSCORRUPTED;
3687         }
3688
3689         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3690             (!projid_eq(EXT4_I(new_dir)->i_projid,
3691                         EXT4_I(old_dentry->d_inode)->i_projid)))
3692                 return -EXDEV;
3693
3694         retval = dquot_initialize(old.dir);
3695         if (retval)
3696                 return retval;
3697         retval = dquot_initialize(new.dir);
3698         if (retval)
3699                 return retval;
3700
3701         /* Initialize quotas before so that eventual writes go
3702          * in separate transaction */
3703         if (new.inode) {
3704                 retval = dquot_initialize(new.inode);
3705                 if (retval)
3706                         return retval;
3707         }
3708
3709         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3710         if (IS_ERR(old.bh))
3711                 return PTR_ERR(old.bh);
3712         /*
3713          *  Check for inode number is _not_ due to possible IO errors.
3714          *  We might rmdir the source, keep it as pwd of some process
3715          *  and merrily kill the link to whatever was created under the
3716          *  same name. Goodbye sticky bit ;-<
3717          */
3718         retval = -ENOENT;
3719         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3720                 goto end_rename;
3721
3722         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3723                                  &new.de, &new.inlined);
3724         if (IS_ERR(new.bh)) {
3725                 retval = PTR_ERR(new.bh);
3726                 new.bh = NULL;
3727                 goto end_rename;
3728         }
3729         if (new.bh) {
3730                 if (!new.inode) {
3731                         brelse(new.bh);
3732                         new.bh = NULL;
3733                 }
3734         }
3735         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3736                 ext4_alloc_da_blocks(old.inode);
3737
3738         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3739                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3740         if (!(flags & RENAME_WHITEOUT)) {
3741                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3742                 if (IS_ERR(handle)) {
3743                         retval = PTR_ERR(handle);
3744                         handle = NULL;
3745                         goto end_rename;
3746                 }
3747         } else {
3748                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3749                 if (IS_ERR(whiteout)) {
3750                         retval = PTR_ERR(whiteout);
3751                         whiteout = NULL;
3752                         goto end_rename;
3753                 }
3754         }
3755
3756         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3757                 ext4_handle_sync(handle);
3758
3759         if (S_ISDIR(old.inode->i_mode)) {
3760                 if (new.inode) {
3761                         retval = -ENOTEMPTY;
3762                         if (!ext4_empty_dir(new.inode))
3763                                 goto end_rename;
3764                 } else {
3765                         retval = -EMLINK;
3766                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3767                                 goto end_rename;
3768                 }
3769                 retval = ext4_rename_dir_prepare(handle, &old);
3770                 if (retval)
3771                         goto end_rename;
3772         }
3773         /*
3774          * If we're renaming a file within an inline_data dir and adding or
3775          * setting the new dirent causes a conversion from inline_data to
3776          * extents/blockmap, we need to force the dirent delete code to
3777          * re-read the directory, or else we end up trying to delete a dirent
3778          * from what is now the extent tree root (or a block map).
3779          */
3780         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3781                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3782
3783         old_file_type = old.de->file_type;
3784         if (whiteout) {
3785                 /*
3786                  * Do this before adding a new entry, so the old entry is sure
3787                  * to be still pointing to the valid old entry.
3788                  */
3789                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3790                                      EXT4_FT_CHRDEV);
3791                 if (retval)
3792                         goto end_rename;
3793                 ext4_mark_inode_dirty(handle, whiteout);
3794         }
3795         if (!new.bh) {
3796                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3797                 if (retval)
3798                         goto end_rename;
3799         } else {
3800                 retval = ext4_setent(handle, &new,
3801                                      old.inode->i_ino, old_file_type);
3802                 if (retval)
3803                         goto end_rename;
3804         }
3805         if (force_reread)
3806                 force_reread = !ext4_test_inode_flag(new.dir,
3807                                                      EXT4_INODE_INLINE_DATA);
3808
3809         /*
3810          * Like most other Unix systems, set the ctime for inodes on a
3811          * rename.
3812          */
3813         old.inode->i_ctime = current_time(old.inode);
3814         ext4_mark_inode_dirty(handle, old.inode);
3815
3816         if (!whiteout) {
3817                 /*
3818                  * ok, that's it
3819                  */
3820                 ext4_rename_delete(handle, &old, force_reread);
3821         }
3822
3823         if (new.inode) {
3824                 ext4_dec_count(handle, new.inode);
3825                 new.inode->i_ctime = current_time(new.inode);
3826         }
3827         old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
3828         ext4_update_dx_flag(old.dir);
3829         if (old.dir_bh) {
3830                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3831                 if (retval)
3832                         goto end_rename;
3833
3834                 ext4_dec_count(handle, old.dir);
3835                 if (new.inode) {
3836                         /* checked ext4_empty_dir above, can't have another
3837                          * parent, ext4_dec_count() won't work for many-linked
3838                          * dirs */
3839                         clear_nlink(new.inode);
3840                 } else {
3841                         ext4_inc_count(handle, new.dir);
3842                         ext4_update_dx_flag(new.dir);
3843                         ext4_mark_inode_dirty(handle, new.dir);
3844                 }
3845         }
3846         ext4_mark_inode_dirty(handle, old.dir);
3847         if (new.inode) {
3848                 ext4_mark_inode_dirty(handle, new.inode);
3849                 if (!new.inode->i_nlink)
3850                         ext4_orphan_add(handle, new.inode);
3851         }
3852         retval = 0;
3853
3854 end_rename:
3855         brelse(old.dir_bh);
3856         brelse(old.bh);
3857         brelse(new.bh);
3858         if (whiteout) {
3859                 if (retval)
3860                         drop_nlink(whiteout);
3861                 unlock_new_inode(whiteout);
3862                 iput(whiteout);
3863         }
3864         if (handle)
3865                 ext4_journal_stop(handle);
3866         return retval;
3867 }
3868
3869 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3870                              struct inode *new_dir, struct dentry *new_dentry)
3871 {
3872         handle_t *handle = NULL;
3873         struct ext4_renament old = {
3874                 .dir = old_dir,
3875                 .dentry = old_dentry,
3876                 .inode = d_inode(old_dentry),
3877         };
3878         struct ext4_renament new = {
3879                 .dir = new_dir,
3880                 .dentry = new_dentry,
3881                 .inode = d_inode(new_dentry),
3882         };
3883         u8 new_file_type;
3884         int retval;
3885         struct timespec64 ctime;
3886
3887         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3888              !projid_eq(EXT4_I(new_dir)->i_projid,
3889                         EXT4_I(old_dentry->d_inode)->i_projid)) ||
3890             (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3891              !projid_eq(EXT4_I(old_dir)->i_projid,
3892                         EXT4_I(new_dentry->d_inode)->i_projid)))
3893                 return -EXDEV;
3894
3895         retval = dquot_initialize(old.dir);
3896         if (retval)
3897                 return retval;
3898         retval = dquot_initialize(new.dir);
3899         if (retval)
3900                 return retval;
3901
3902         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3903                                  &old.de, &old.inlined);
3904         if (IS_ERR(old.bh))
3905                 return PTR_ERR(old.bh);
3906         /*
3907          *  Check for inode number is _not_ due to possible IO errors.
3908          *  We might rmdir the source, keep it as pwd of some process
3909          *  and merrily kill the link to whatever was created under the
3910          *  same name. Goodbye sticky bit ;-<
3911          */
3912         retval = -ENOENT;
3913         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3914                 goto end_rename;
3915
3916         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3917                                  &new.de, &new.inlined);
3918         if (IS_ERR(new.bh)) {
3919                 retval = PTR_ERR(new.bh);
3920                 new.bh = NULL;
3921                 goto end_rename;
3922         }
3923
3924         /* RENAME_EXCHANGE case: old *and* new must both exist */
3925         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3926                 goto end_rename;
3927
3928         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3929                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3930                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3931         if (IS_ERR(handle)) {
3932                 retval = PTR_ERR(handle);
3933                 handle = NULL;
3934                 goto end_rename;
3935         }
3936
3937         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3938                 ext4_handle_sync(handle);
3939
3940         if (S_ISDIR(old.inode->i_mode)) {
3941                 old.is_dir = true;
3942                 retval = ext4_rename_dir_prepare(handle, &old);
3943                 if (retval)
3944                         goto end_rename;
3945         }
3946         if (S_ISDIR(new.inode->i_mode)) {
3947                 new.is_dir = true;
3948                 retval = ext4_rename_dir_prepare(handle, &new);
3949                 if (retval)
3950                         goto end_rename;
3951         }
3952
3953         /*
3954          * Other than the special case of overwriting a directory, parents'
3955          * nlink only needs to be modified if this is a cross directory rename.
3956          */
3957         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3958                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3959                 new.dir_nlink_delta = -old.dir_nlink_delta;
3960                 retval = -EMLINK;
3961                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3962                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3963                         goto end_rename;
3964         }
3965
3966         new_file_type = new.de->file_type;
3967         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3968         if (retval)
3969                 goto end_rename;
3970
3971         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3972         if (retval)
3973                 goto end_rename;
3974
3975         /*
3976          * Like most other Unix systems, set the ctime for inodes on a
3977          * rename.
3978          */
3979         ctime = current_time(old.inode);
3980         old.inode->i_ctime = ctime;
3981         new.inode->i_ctime = ctime;
3982         ext4_mark_inode_dirty(handle, old.inode);
3983         ext4_mark_inode_dirty(handle, new.inode);
3984
3985         if (old.dir_bh) {
3986                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3987                 if (retval)
3988                         goto end_rename;
3989         }
3990         if (new.dir_bh) {
3991                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3992                 if (retval)
3993                         goto end_rename;
3994         }
3995         ext4_update_dir_count(handle, &old);
3996         ext4_update_dir_count(handle, &new);
3997         retval = 0;
3998
3999 end_rename:
4000         brelse(old.dir_bh);
4001         brelse(new.dir_bh);
4002         brelse(old.bh);
4003         brelse(new.bh);
4004         if (handle)
4005                 ext4_journal_stop(handle);
4006         return retval;
4007 }
4008
4009 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
4010                         struct inode *new_dir, struct dentry *new_dentry,
4011                         unsigned int flags)
4012 {
4013         int err;
4014
4015         if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
4016                 return -EIO;
4017
4018         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
4019                 return -EINVAL;
4020
4021         err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
4022                                      flags);
4023         if (err)
4024                 return err;
4025
4026         if (flags & RENAME_EXCHANGE) {
4027                 return ext4_cross_rename(old_dir, old_dentry,
4028                                          new_dir, new_dentry);
4029         }
4030
4031         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
4032 }
4033
4034 /*
4035  * directories can handle most operations...
4036  */
4037 const struct inode_operations ext4_dir_inode_operations = {
4038         .create         = ext4_create,
4039         .lookup         = ext4_lookup,
4040         .link           = ext4_link,
4041         .unlink         = ext4_unlink,
4042         .symlink        = ext4_symlink,
4043         .mkdir          = ext4_mkdir,
4044         .rmdir          = ext4_rmdir,
4045         .mknod          = ext4_mknod,
4046         .tmpfile        = ext4_tmpfile,
4047         .rename         = ext4_rename2,
4048         .setattr        = ext4_setattr,
4049         .getattr        = ext4_getattr,
4050         .listxattr      = ext4_listxattr,
4051         .get_acl        = ext4_get_acl,
4052         .set_acl        = ext4_set_acl,
4053         .fiemap         = ext4_fiemap,
4054 };
4055
4056 const struct inode_operations ext4_special_inode_operations = {
4057         .setattr        = ext4_setattr,
4058         .getattr        = ext4_getattr,
4059         .listxattr      = ext4_listxattr,
4060         .get_acl        = ext4_get_acl,
4061         .set_acl        = ext4_set_acl,
4062 };