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 #ifdef DX_DEBUG
 186 #define dxtrace(command) command
 187 #else
 188 #define dxtrace(command)
 189 #endif
 190
 191 struct fake_dirent
 192 {
 193         __le32 inode;
 194         __le16 rec_len;
 195         u8 name_len;
 196         u8 file_type;
 197 };
 198
 199 struct dx_countlimit
 200 {
 201         __le16 limit;
 202         __le16 count;
 203 };
 204
 205 struct dx_entry
 206 {
 207         __le32 hash;
 208         __le32 block;
 209 };
 210
 211 /*
 212  * dx_root_info is laid out so that if it should somehow get overlaid by a
 213  * dirent the two low bits of the hash version will be zero.  Therefore, the
 214  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 215  */
 216
 217 struct dx_root
 218 {
 219         struct fake_dirent dot;
 220         char dot_name[4];
 221         struct fake_dirent dotdot;
 222         char dotdot_name[4];
 223         struct dx_root_info
 224         {
 225                 __le32 reserved_zero;
 226                 u8 hash_version;
 227                 u8 info_length; /* 8 */
 228                 u8 indirect_levels;
 229                 u8 unused_flags;
 230         }
 231         info;
 232         struct dx_entry entries[];
 233 };
 234
 235 struct dx_node
 236 {
 237         struct fake_dirent fake;
 238         struct dx_entry entries[];
 239 };
 240
 241
 242 struct dx_frame
 243 {
 244         struct buffer_head *bh;
 245         struct dx_entry *entries;
 246         struct dx_entry *at;
 247 };
 248
 249 struct dx_map_entry
 250 {
 251         u32 hash;
 252         u16 offs;
 253         u16 size;
 254 };
 255
 256 /*
 257  * This goes at the end of each htree block.
 258  */
 259 struct dx_tail {
 260         u32 dt_reserved;
 261         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 262 };
 263
 264 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 265 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 266 static inline unsigned dx_get_hash(struct dx_entry *entry);
 267 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 268 static unsigned dx_get_count(struct dx_entry *entries);
 269 static unsigned dx_get_limit(struct dx_entry *entries);
 270 static void dx_set_count(struct dx_entry *entries, unsigned value);
 271 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 272 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 273 static unsigned dx_node_limit(struct inode *dir);
 274 static struct dx_frame *dx_probe(struct ext4_filename *fname,
 275                                  struct inode *dir,
 276                                  struct dx_hash_info *hinfo,
 277                                  struct dx_frame *frame);
 278 static void dx_release(struct dx_frame *frames);
 279 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 280                        unsigned blocksize, struct dx_hash_info *hinfo,
 281                        struct dx_map_entry map[]);
 282 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 283 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 284                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 285 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 286 static void dx_insert_block(struct dx_frame *frame,
 287                                         u32 hash, ext4_lblk_t block);
 288 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 289                                  struct dx_frame *frame,
 290                                  struct dx_frame *frames,
 291                                  __u32 *start_hash);
 292 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 293                 struct ext4_filename *fname,
 294                 struct ext4_dir_entry_2 **res_dir);
 295 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 296                              struct inode *dir, struct inode *inode);
 297
 298 /* checksumming functions */
 299 void ext4_initialize_dirent_tail(struct buffer_head *bh,
 300                                  unsigned int blocksize)
 301 {
 302         struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
 303
 304         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 305         t->det_rec_len = ext4_rec_len_to_disk(
 306                         sizeof(struct ext4_dir_entry_tail), blocksize);
 307         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 308 }
 309
 310 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 311 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 312                                                    struct buffer_head *bh)
 313 {
 314         struct ext4_dir_entry_tail *t;
 315
 316 #ifdef PARANOID
 317         struct ext4_dir_entry *d, *top;
 318
 319         d = (struct ext4_dir_entry *)bh->b_data;
 320         top = (struct ext4_dir_entry *)(bh->b_data +
 321                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 322                  sizeof(struct ext4_dir_entry_tail)));
 323         while (d < top && d->rec_len)
 324                 d = (struct ext4_dir_entry *)(((void *)d) +
 325                     le16_to_cpu(d->rec_len));
 326
 327         if (d != top)
 328                 return NULL;
 329
 330         t = (struct ext4_dir_entry_tail *)d;
 331 #else
 332         t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
 333 #endif
 334
 335         if (t->det_reserved_zero1 ||
 336             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 337             t->det_reserved_zero2 ||
 338             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 339                 return NULL;
 340
 341         return t;
 342 }
 343
 344 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
 345 {
 346         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 347         struct ext4_inode_info *ei = EXT4_I(inode);
 348         __u32 csum;
 349
 350         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 351         return cpu_to_le32(csum);
 352 }
 353
 354 #define warn_no_space_for_csum(inode)                                   \
 355         __warn_no_space_for_csum((inode), __func__, __LINE__)
 356
 357 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
 358                                      unsigned int line)
 359 {
 360         __ext4_warning_inode(inode, func, line,
 361                 "No space for directory leaf checksum. Please run e2fsck -D.");
 362 }
 363
 364 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
 365 {
 366         struct ext4_dir_entry_tail *t;
 367
 368         if (!ext4_has_metadata_csum(inode->i_sb))
 369                 return 1;
 370
 371         t = get_dirent_tail(inode, bh);
 372         if (!t) {
 373                 warn_no_space_for_csum(inode);
 374                 return 0;
 375         }
 376
 377         if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data,
 378                                                   (char *)t - bh->b_data))
 379                 return 0;
 380
 381         return 1;
 382 }
 383
 384 static void ext4_dirblock_csum_set(struct inode *inode,
 385                                  struct buffer_head *bh)
 386 {
 387         struct ext4_dir_entry_tail *t;
 388
 389         if (!ext4_has_metadata_csum(inode->i_sb))
 390                 return;
 391
 392         t = get_dirent_tail(inode, bh);
 393         if (!t) {
 394                 warn_no_space_for_csum(inode);
 395                 return;
 396         }
 397
 398         t->det_checksum = ext4_dirblock_csum(inode, bh->b_data,
 399                                              (char *)t - bh->b_data);
 400 }
 401
 402 int ext4_handle_dirty_dirblock(handle_t *handle,
 403                                struct inode *inode,
 404                                struct buffer_head *bh)
 405 {
 406         ext4_dirblock_csum_set(inode, bh);
 407         return ext4_handle_dirty_metadata(handle, inode, bh);
 408 }
 409
 410 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 411                                                struct ext4_dir_entry *dirent,
 412                                                int *offset)
 413 {
 414         struct ext4_dir_entry *dp;
 415         struct dx_root_info *root;
 416         int count_offset;
 417
 418         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 419                 count_offset = 8;
 420         else if (le16_to_cpu(dirent->rec_len) == 12) {
 421                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 422                 if (le16_to_cpu(dp->rec_len) !=
 423                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 424                         return NULL;
 425                 root = (struct dx_root_info *)(((void *)dp + 12));
 426                 if (root->reserved_zero ||
 427                     root->info_length != sizeof(struct dx_root_info))
 428                         return NULL;
 429                 count_offset = 32;
 430         } else
 431                 return NULL;
 432
 433         if (offset)
 434                 *offset = count_offset;
 435         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 436 }
 437
 438 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 439                            int count_offset, int count, struct dx_tail *t)
 440 {
 441         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 442         struct ext4_inode_info *ei = EXT4_I(inode);
 443         __u32 csum;
 444         int size;
 445         __u32 dummy_csum = 0;
 446         int offset = offsetof(struct dx_tail, dt_checksum);
 447
 448         size = count_offset + (count * sizeof(struct dx_entry));
 449         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 450         csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
 451         csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
 452
 453         return cpu_to_le32(csum);
 454 }
 455
 456 static int ext4_dx_csum_verify(struct inode *inode,
 457                                struct ext4_dir_entry *dirent)
 458 {
 459         struct dx_countlimit *c;
 460         struct dx_tail *t;
 461         int count_offset, limit, count;
 462
 463         if (!ext4_has_metadata_csum(inode->i_sb))
 464                 return 1;
 465
 466         c = get_dx_countlimit(inode, dirent, &count_offset);
 467         if (!c) {
 468                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 469                 return 0;
 470         }
 471         limit = le16_to_cpu(c->limit);
 472         count = le16_to_cpu(c->count);
 473         if (count_offset + (limit * sizeof(struct dx_entry)) >
 474             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 475                 warn_no_space_for_csum(inode);
 476                 return 0;
 477         }
 478         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 479
 480         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 481                                             count, t))
 482                 return 0;
 483         return 1;
 484 }
 485
 486 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 487 {
 488         struct dx_countlimit *c;
 489         struct dx_tail *t;
 490         int count_offset, limit, count;
 491
 492         if (!ext4_has_metadata_csum(inode->i_sb))
 493                 return;
 494
 495         c = get_dx_countlimit(inode, dirent, &count_offset);
 496         if (!c) {
 497                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 498                 return;
 499         }
 500         limit = le16_to_cpu(c->limit);
 501         count = le16_to_cpu(c->count);
 502         if (count_offset + (limit * sizeof(struct dx_entry)) >
 503             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 504                 warn_no_space_for_csum(inode);
 505                 return;
 506         }
 507         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 508
 509         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 510 }
 511
 512 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 513                                             struct inode *inode,
 514                                             struct buffer_head *bh)
 515 {
 516         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 517         return ext4_handle_dirty_metadata(handle, inode, bh);
 518 }
 519
 520 /*
 521  * p is at least 6 bytes before the end of page
 522  */
 523 static inline struct ext4_dir_entry_2 *
 524 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 525 {
 526         return (struct ext4_dir_entry_2 *)((char *)p +
 527                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 528 }
 529
 530 /*
 531  * Future: use high four bits of block for coalesce-on-delete flags
 532  * Mask them off for now.
 533  */
 534
 535 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 536 {
 537         return le32_to_cpu(entry->block) & 0x0fffffff;
 538 }
 539
 540 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 541 {
 542         entry->block = cpu_to_le32(value);
 543 }
 544
 545 static inline unsigned dx_get_hash(struct dx_entry *entry)
 546 {
 547         return le32_to_cpu(entry->hash);
 548 }
 549
 550 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 551 {
 552         entry->hash = cpu_to_le32(value);
 553 }
 554
 555 static inline unsigned dx_get_count(struct dx_entry *entries)
 556 {
 557         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 558 }
 559
 560 static inline unsigned dx_get_limit(struct dx_entry *entries)
 561 {
 562         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 563 }
 564
 565 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 566 {
 567         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 568 }
 569
 570 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 571 {
 572         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 573 }
 574
 575 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 576 {
 577         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 578                 EXT4_DIR_REC_LEN(2) - infosize;
 579
 580         if (ext4_has_metadata_csum(dir->i_sb))
 581                 entry_space -= sizeof(struct dx_tail);
 582         return entry_space / sizeof(struct dx_entry);
 583 }
 584
 585 static inline unsigned dx_node_limit(struct inode *dir)
 586 {
 587         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 588
 589         if (ext4_has_metadata_csum(dir->i_sb))
 590                 entry_space -= sizeof(struct dx_tail);
 591         return entry_space / sizeof(struct dx_entry);
 592 }
 593
 594 /*
 595  * Debug
 596  */
 597 #ifdef DX_DEBUG
 598 static void dx_show_index(char * label, struct dx_entry *entries)
 599 {
 600         int i, n = dx_get_count (entries);
 601         printk(KERN_DEBUG "%s index", label);
 602         for (i = 0; i < n; i++) {
 603                 printk(KERN_CONT " %x->%lu",
 604                        i ? dx_get_hash(entries + i) : 0,
 605                        (unsigned long)dx_get_block(entries + i));
 606         }
 607         printk(KERN_CONT "\n");
 608 }
 609
 610 struct stats
 611 {
 612         unsigned names;
 613         unsigned space;
 614         unsigned bcount;
 615 };
 616
 617 static struct stats dx_show_leaf(struct inode *dir,
 618                                 struct dx_hash_info *hinfo,
 619                                 struct ext4_dir_entry_2 *de,
 620                                 int size, int show_names)
 621 {
 622         unsigned names = 0, space = 0;
 623         char *base = (char *) de;
 624         struct dx_hash_info h = *hinfo;
 625
 626         printk("names: ");
 627         while ((char *) de < base + size)
 628         {
 629                 if (de->inode)
 630                 {
 631                         if (show_names)
 632                         {
 633 #ifdef CONFIG_FS_ENCRYPTION
 634                                 int len;
 635                                 char *name;
 636                                 struct fscrypt_str fname_crypto_str =
 637                                         FSTR_INIT(NULL, 0);
 638                                 int res = 0;
 639
 640                                 name  = de->name;
 641                                 len = de->name_len;
 642                                 if (!IS_ENCRYPTED(dir)) {
 643                                         /* Directory is not encrypted */
 644                                         ext4fs_dirhash(dir, de->name,
 645                                                 de->name_len, &h);
 646                                         printk("%*.s:(U)%x.%u ", len,
 647                                                name, h.hash,
 648                                                (unsigned) ((char *) de
 649                                                            - base));
 650                                 } else {
 651                                         struct fscrypt_str de_name =
 652                                                 FSTR_INIT(name, len);
 653
 654                                         /* Directory is encrypted */
 655                                         res = fscrypt_fname_alloc_buffer(
 656                                                 len, &fname_crypto_str);
 657                                         if (res)
 658                                                 printk(KERN_WARNING "Error "
 659                                                         "allocating crypto "
 660                                                         "buffer--skipping "
 661                                                         "crypto\n");
 662                                         res = fscrypt_fname_disk_to_usr(dir,
 663                                                 0, 0, &de_name,
 664                                                 &fname_crypto_str);
 665                                         if (res) {
 666                                                 printk(KERN_WARNING "Error "
 667                                                         "converting filename "
 668                                                         "from disk to usr"
 669                                                         "\n");
 670                                                 name = "??";
 671                                                 len = 2;
 672                                         } else {
 673                                                 name = fname_crypto_str.name;
 674                                                 len = fname_crypto_str.len;
 675                                         }
 676                                         ext4fs_dirhash(dir, de->name,
 677                                                        de->name_len, &h);
 678                                         printk("%*.s:(E)%x.%u ", len, name,
 679                                                h.hash, (unsigned) ((char *) de
 680                                                                    - base));
 681                                         fscrypt_fname_free_buffer(
 682                                                         &fname_crypto_str);
 683                                 }
 684 #else
 685                                 int len = de->name_len;
 686                                 char *name = de->name;
 687                                 ext4fs_dirhash(dir, de->name, de->name_len, &h);
 688                                 printk("%*.s:%x.%u ", len, name, h.hash,
 689                                        (unsigned) ((char *) de - base));
 690 #endif
 691                         }
 692                         space += EXT4_DIR_REC_LEN(de->name_len);
 693                         names++;
 694                 }
 695                 de = ext4_next_entry(de, size);
 696         }
 697         printk(KERN_CONT "(%i)\n", names);
 698         return (struct stats) { names, space, 1 };
 699 }
 700
 701 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 702                              struct dx_entry *entries, int levels)
 703 {
 704         unsigned blocksize = dir->i_sb->s_blocksize;
 705         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 706         unsigned bcount = 0;
 707         struct buffer_head *bh;
 708         printk("%i indexed blocks...\n", count);
 709         for (i = 0; i < count; i++, entries++)
 710         {
 711                 ext4_lblk_t block = dx_get_block(entries);
 712                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 713                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 714                 struct stats stats;
 715                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 716                 bh = ext4_bread(NULL,dir, block, 0);
 717                 if (!bh || IS_ERR(bh))
 718                         continue;
 719                 stats = levels?
 720                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 721                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 722                         bh->b_data, blocksize, 0);
 723                 names += stats.names;
 724                 space += stats.space;
 725                 bcount += stats.bcount;
 726                 brelse(bh);
 727         }
 728         if (bcount)
 729                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 730                        levels ? "" : "   ", names, space/bcount,
 731                        (space/bcount)*100/blocksize);
 732         return (struct stats) { names, space, bcount};
 733 }
 734
 735 /*
 736  * Linear search cross check
 737  */
 738 static inline void htree_rep_invariant_check(struct dx_entry *at,
 739                                              struct dx_entry *target,
 740                                              u32 hash, unsigned int n)
 741 {
 742         while (n--) {
 743                 dxtrace(printk(KERN_CONT ","));
 744                 if (dx_get_hash(++at) > hash) {
 745                         at--;
 746                         break;
 747                 }
 748         }
 749         ASSERT(at == target - 1);
 750 }
 751 #else /* DX_DEBUG */
 752 static inline void htree_rep_invariant_check(struct dx_entry *at,
 753                                              struct dx_entry *target,
 754                                              u32 hash, unsigned int n)
 755 {
 756 }
 757 #endif /* DX_DEBUG */
 758
 759 /*
 760  * Probe for a directory leaf block to search.
 761  *
 762  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 763  * error in the directory index, and the caller should fall back to
 764  * searching the directory normally.  The callers of dx_probe **MUST**
 765  * check for this error code, and make sure it never gets reflected
 766  * back to userspace.
 767  */
 768 static struct dx_frame *
 769 dx_probe(struct ext4_filename *fname, struct inode *dir,
 770          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 771 {
 772         unsigned count, indirect;
 773         struct dx_entry *at, *entries, *p, *q, *m;
 774         struct dx_root *root;
 775         struct dx_frame *frame = frame_in;
 776         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 777         u32 hash;
 778
 779         memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
 780         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 781         if (IS_ERR(frame->bh))
 782                 return (struct dx_frame *) frame->bh;
 783
 784         root = (struct dx_root *) frame->bh->b_data;
 785         if (root->info.hash_version != DX_HASH_TEA &&
 786             root->info.hash_version != DX_HASH_HALF_MD4 &&
 787             root->info.hash_version != DX_HASH_LEGACY) {
 788                 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
 789                                    root->info.hash_version);
 790                 goto fail;
 791         }
 792         if (fname)
 793                 hinfo = &fname->hinfo;
 794         hinfo->hash_version = root->info.hash_version;
 795         if (hinfo->hash_version <= DX_HASH_TEA)
 796                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 797         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 798         if (fname && fname_name(fname))
 799                 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
 800         hash = hinfo->hash;
 801
 802         if (root->info.unused_flags & 1) {
 803                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
 804                                    root->info.unused_flags);
 805                 goto fail;
 806         }
 807
 808         indirect = root->info.indirect_levels;
 809         if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
 810                 ext4_warning(dir->i_sb,
 811                              "Directory (ino: %lu) htree depth %#06x exceed"
 812                              "supported value", dir->i_ino,
 813                              ext4_dir_htree_level(dir->i_sb));
 814                 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
 815                         ext4_warning(dir->i_sb, "Enable large directory "
 816                                                 "feature to access it");
 817                 }
 818                 goto fail;
 819         }
 820
 821         entries = (struct dx_entry *)(((char *)&root->info) +
 822                                       root->info.info_length);
 823
 824         if (dx_get_limit(entries) != dx_root_limit(dir,
 825                                                    root->info.info_length)) {
 826                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 827                                    dx_get_limit(entries),
 828                                    dx_root_limit(dir, root->info.info_length));
 829                 goto fail;
 830         }
 831
 832         dxtrace(printk("Look up %x", hash));
 833         while (1) {
 834                 count = dx_get_count(entries);
 835                 if (!count || count > dx_get_limit(entries)) {
 836                         ext4_warning_inode(dir,
 837                                            "dx entry: count %u beyond limit %u",
 838                                            count, dx_get_limit(entries));
 839                         goto fail;
 840                 }
 841
 842                 p = entries + 1;
 843                 q = entries + count - 1;
 844                 while (p <= q) {
 845                         m = p + (q - p) / 2;
 846                         dxtrace(printk(KERN_CONT "."));
 847                         if (dx_get_hash(m) > hash)
 848                                 q = m - 1;
 849                         else
 850                                 p = m + 1;
 851                 }
 852
 853                 htree_rep_invariant_check(entries, p, hash, count - 1);
 854
 855                 at = p - 1;
 856                 dxtrace(printk(KERN_CONT " %x->%u\n",
 857                                at == entries ? 0 : dx_get_hash(at),
 858                                dx_get_block(at)));
 859                 frame->entries = entries;
 860                 frame->at = at;
 861                 if (!indirect--)
 862                         return frame;
 863                 frame++;
 864                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 865                 if (IS_ERR(frame->bh)) {
 866                         ret_err = (struct dx_frame *) frame->bh;
 867                         frame->bh = NULL;
 868                         goto fail;
 869                 }
 870                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 871
 872                 if (dx_get_limit(entries) != dx_node_limit(dir)) {
 873                         ext4_warning_inode(dir,
 874                                 "dx entry: limit %u != node limit %u",
 875                                 dx_get_limit(entries), dx_node_limit(dir));
 876                         goto fail;
 877                 }
 878         }
 879 fail:
 880         while (frame >= frame_in) {
 881                 brelse(frame->bh);
 882                 frame--;
 883         }
 884
 885         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 886                 ext4_warning_inode(dir,
 887                         "Corrupt directory, running e2fsck is recommended");
 888         return ret_err;
 889 }
 890
 891 static void dx_release(struct dx_frame *frames)
 892 {
 893         struct dx_root_info *info;
 894         int i;
 895         unsigned int indirect_levels;
 896
 897         if (frames[0].bh == NULL)
 898                 return;
 899
 900         info = &((struct dx_root *)frames[0].bh->b_data)->info;
 901         /* save local copy, "info" may be freed after brelse() */
 902         indirect_levels = info->indirect_levels;
 903         for (i = 0; i <= indirect_levels; i++) {
 904                 if (frames[i].bh == NULL)
 905                         break;
 906                 brelse(frames[i].bh);
 907                 frames[i].bh = NULL;
 908         }
 909 }
 910
 911 /*
 912  * This function increments the frame pointer to search the next leaf
 913  * block, and reads in the necessary intervening nodes if the search
 914  * should be necessary.  Whether or not the search is necessary is
 915  * controlled by the hash parameter.  If the hash value is even, then
 916  * the search is only continued if the next block starts with that
 917  * hash value.  This is used if we are searching for a specific file.
 918  *
 919  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 920  *
 921  * This function returns 1 if the caller should continue to search,
 922  * or 0 if it should not.  If there is an error reading one of the
 923  * index blocks, it will a negative error code.
 924  *
 925  * If start_hash is non-null, it will be filled in with the starting
 926  * hash of the next page.
 927  */
 928 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 929                                  struct dx_frame *frame,
 930                                  struct dx_frame *frames,
 931                                  __u32 *start_hash)
 932 {
 933         struct dx_frame *p;
 934         struct buffer_head *bh;
 935         int num_frames = 0;
 936         __u32 bhash;
 937
 938         p = frame;
 939         /*
 940          * Find the next leaf page by incrementing the frame pointer.
 941          * If we run out of entries in the interior node, loop around and
 942          * increment pointer in the parent node.  When we break out of
 943          * this loop, num_frames indicates the number of interior
 944          * nodes need to be read.
 945          */
 946         while (1) {
 947                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 948                         break;
 949                 if (p == frames)
 950                         return 0;
 951                 num_frames++;
 952                 p--;
 953         }
 954
 955         /*
 956          * If the hash is 1, then continue only if the next page has a
 957          * continuation hash of any value.  This is used for readdir
 958          * handling.  Otherwise, check to see if the hash matches the
 959          * desired contiuation hash.  If it doesn't, return since
 960          * there's no point to read in the successive index pages.
 961          */
 962         bhash = dx_get_hash(p->at);
 963         if (start_hash)
 964                 *start_hash = bhash;
 965         if ((hash & 1) == 0) {
 966                 if ((bhash & ~1) != hash)
 967                         return 0;
 968         }
 969         /*
 970          * If the hash is HASH_NB_ALWAYS, we always go to the next
 971          * block so no check is necessary
 972          */
 973         while (num_frames--) {
 974                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 975                 if (IS_ERR(bh))
 976                         return PTR_ERR(bh);
 977                 p++;
 978                 brelse(p->bh);
 979                 p->bh = bh;
 980                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 981         }
 982         return 1;
 983 }
 984
 985
 986 /*
 987  * This function fills a red-black tree with information from a
 988  * directory block.  It returns the number directory entries loaded
 989  * into the tree.  If there is an error it is returned in err.
 990  */
 991 static int htree_dirblock_to_tree(struct file *dir_file,
 992                                   struct inode *dir, ext4_lblk_t block,
 993                                   struct dx_hash_info *hinfo,
 994                                   __u32 start_hash, __u32 start_minor_hash)
 995 {
 996         struct buffer_head *bh;
 997         struct ext4_dir_entry_2 *de, *top;
 998         int err = 0, count = 0;
 999         struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
1000
1001         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
1002                                                         (unsigned long)block));
1003         bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1004         if (IS_ERR(bh))
1005                 return PTR_ERR(bh);
1006
1007         de = (struct ext4_dir_entry_2 *) bh->b_data;
1008         top = (struct ext4_dir_entry_2 *) ((char *) de +
1009                                            dir->i_sb->s_blocksize -
1010                                            EXT4_DIR_REC_LEN(0));
1011         /* Check if the directory is encrypted */
1012         if (IS_ENCRYPTED(dir)) {
1013                 err = fscrypt_prepare_readdir(dir);
1014                 if (err < 0) {
1015                         brelse(bh);
1016                         return err;
1017                 }
1018                 err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN,
1019                                                  &fname_crypto_str);
1020                 if (err < 0) {
1021                         brelse(bh);
1022                         return err;
1023                 }
1024         }
1025
1026         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1027                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1028                                 bh->b_data, bh->b_size,
1029                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1030                                          + ((char *)de - bh->b_data))) {
1031                         /* silently ignore the rest of the block */
1032                         break;
1033                 }
1034                 ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
1035                 if ((hinfo->hash < start_hash) ||
1036                     ((hinfo->hash == start_hash) &&
1037                      (hinfo->minor_hash < start_minor_hash)))
1038                         continue;
1039                 if (de->inode == 0)
1040                         continue;
1041                 if (!IS_ENCRYPTED(dir)) {
1042                         tmp_str.name = de->name;
1043                         tmp_str.len = de->name_len;
1044                         err = ext4_htree_store_dirent(dir_file,
1045                                    hinfo->hash, hinfo->minor_hash, de,
1046                                    &tmp_str);
1047                 } else {
1048                         int save_len = fname_crypto_str.len;
1049                         struct fscrypt_str de_name = FSTR_INIT(de->name,
1050                                                                 de->name_len);
1051
1052                         /* Directory is encrypted */
1053                         err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1054                                         hinfo->minor_hash, &de_name,
1055                                         &fname_crypto_str);
1056                         if (err) {
1057                                 count = err;
1058                                 goto errout;
1059                         }
1060                         err = ext4_htree_store_dirent(dir_file,
1061                                    hinfo->hash, hinfo->minor_hash, de,
1062                                         &fname_crypto_str);
1063                         fname_crypto_str.len = save_len;
1064                 }
1065                 if (err != 0) {
1066                         count = err;
1067                         goto errout;
1068                 }
1069                 count++;
1070         }
1071 errout:
1072         brelse(bh);
1073         fscrypt_fname_free_buffer(&fname_crypto_str);
1074         return count;
1075 }
1076
1077
1078 /*
1079  * This function fills a red-black tree with information from a
1080  * directory.  We start scanning the directory in hash order, starting
1081  * at start_hash and start_minor_hash.
1082  *
1083  * This function returns the number of entries inserted into the tree,
1084  * or a negative error code.
1085  */
1086 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1087                          __u32 start_minor_hash, __u32 *next_hash)
1088 {
1089         struct dx_hash_info hinfo;
1090         struct ext4_dir_entry_2 *de;
1091         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1092         struct inode *dir;
1093         ext4_lblk_t block;
1094         int count = 0;
1095         int ret, err;
1096         __u32 hashval;
1097         struct fscrypt_str tmp_str;
1098
1099         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1100                        start_hash, start_minor_hash));
1101         dir = file_inode(dir_file);
1102         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1103                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1104                 if (hinfo.hash_version <= DX_HASH_TEA)
1105                         hinfo.hash_version +=
1106                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1107                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1108                 if (ext4_has_inline_data(dir)) {
1109                         int has_inline_data = 1;
1110                         count = ext4_inlinedir_to_tree(dir_file, dir, 0,
1111                                                        &hinfo, start_hash,
1112                                                        start_minor_hash,
1113                                                        &has_inline_data);
1114                         if (has_inline_data) {
1115                                 *next_hash = ~0;
1116                                 return count;
1117                         }
1118                 }
1119                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1120                                                start_hash, start_minor_hash);
1121                 *next_hash = ~0;
1122                 return count;
1123         }
1124         hinfo.hash = start_hash;
1125         hinfo.minor_hash = 0;
1126         frame = dx_probe(NULL, dir, &hinfo, frames);
1127         if (IS_ERR(frame))
1128                 return PTR_ERR(frame);
1129
1130         /* Add '.' and '..' from the htree header */
1131         if (!start_hash && !start_minor_hash) {
1132                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1133                 tmp_str.name = de->name;
1134                 tmp_str.len = de->name_len;
1135                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1136                                               de, &tmp_str);
1137                 if (err != 0)
1138                         goto errout;
1139                 count++;
1140         }
1141         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1142                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1143                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1144                 tmp_str.name = de->name;
1145                 tmp_str.len = de->name_len;
1146                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1147                                               de, &tmp_str);
1148                 if (err != 0)
1149                         goto errout;
1150                 count++;
1151         }
1152
1153         while (1) {
1154                 if (fatal_signal_pending(current)) {
1155                         err = -ERESTARTSYS;
1156                         goto errout;
1157                 }
1158                 cond_resched();
1159                 block = dx_get_block(frame->at);
1160                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1161                                              start_hash, start_minor_hash);
1162                 if (ret < 0) {
1163                         err = ret;
1164                         goto errout;
1165                 }
1166                 count += ret;
1167                 hashval = ~0;
1168                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1169                                             frame, frames, &hashval);
1170                 *next_hash = hashval;
1171                 if (ret < 0) {
1172                         err = ret;
1173                         goto errout;
1174                 }
1175                 /*
1176                  * Stop if:  (a) there are no more entries, or
1177                  * (b) we have inserted at least one entry and the
1178                  * next hash value is not a continuation
1179                  */
1180                 if ((ret == 0) ||
1181                     (count && ((hashval & 1) == 0)))
1182                         break;
1183         }
1184         dx_release(frames);
1185         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1186                        "next hash: %x\n", count, *next_hash));
1187         return count;
1188 errout:
1189         dx_release(frames);
1190         return (err);
1191 }
1192
1193 static inline int search_dirblock(struct buffer_head *bh,
1194                                   struct inode *dir,
1195                                   struct ext4_filename *fname,
1196                                   unsigned int offset,
1197                                   struct ext4_dir_entry_2 **res_dir)
1198 {
1199         return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1200                                fname, offset, res_dir);
1201 }
1202
1203 /*
1204  * Directory block splitting, compacting
1205  */
1206
1207 /*
1208  * Create map of hash values, offsets, and sizes, stored at end of block.
1209  * Returns number of entries mapped.
1210  */
1211 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1212                        unsigned blocksize, struct dx_hash_info *hinfo,
1213                        struct dx_map_entry *map_tail)
1214 {
1215         int count = 0;
1216         char *base = (char *) de;
1217         struct dx_hash_info h = *hinfo;
1218
1219         while ((char *) de < base + blocksize) {
1220                 if (de->name_len && de->inode) {
1221                         ext4fs_dirhash(dir, de->name, de->name_len, &h);
1222                         map_tail--;
1223                         map_tail->hash = h.hash;
1224                         map_tail->offs = ((char *) de - base)>>2;
1225                         map_tail->size = le16_to_cpu(de->rec_len);
1226                         count++;
1227                         cond_resched();
1228                 }
1229                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1230                 de = ext4_next_entry(de, blocksize);
1231         }
1232         return count;
1233 }
1234
1235 /* Sort map by hash value */
1236 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1237 {
1238         struct dx_map_entry *p, *q, *top = map + count - 1;
1239         int more;
1240         /* Combsort until bubble sort doesn't suck */
1241         while (count > 2) {
1242                 count = count*10/13;
1243                 if (count - 9 < 2) /* 9, 10 -> 11 */
1244                         count = 11;
1245                 for (p = top, q = p - count; q >= map; p--, q--)
1246                         if (p->hash < q->hash)
1247                                 swap(*p, *q);
1248         }
1249         /* Garden variety bubble sort */
1250         do {
1251                 more = 0;
1252                 q = top;
1253                 while (q-- > map) {
1254                         if (q[1].hash >= q[0].hash)
1255                                 continue;
1256                         swap(*(q+1), *q);
1257                         more = 1;
1258                 }
1259         } while(more);
1260 }
1261
1262 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1263 {
1264         struct dx_entry *entries = frame->entries;
1265         struct dx_entry *old = frame->at, *new = old + 1;
1266         int count = dx_get_count(entries);
1267
1268         ASSERT(count < dx_get_limit(entries));
1269         ASSERT(old < entries + count);
1270         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1271         dx_set_hash(new, hash);
1272         dx_set_block(new, block);
1273         dx_set_count(entries, count + 1);
1274 }
1275
1276 #ifdef CONFIG_UNICODE
1277 /*
1278  * Test whether a case-insensitive directory entry matches the filename
1279  * being searched for.  If quick is set, assume the name being looked up
1280  * is already in the casefolded form.
1281  *
1282  * Returns: 0 if the directory entry matches, more than 0 if it
1283  * doesn't match or less than zero on error.
1284  */
1285 int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
1286                     const struct qstr *entry, bool quick)
1287 {
1288         const struct super_block *sb = parent->i_sb;
1289         const struct unicode_map *um = sb->s_encoding;
1290         int ret;
1291
1292         if (quick)
1293                 ret = utf8_strncasecmp_folded(um, name, entry);
1294         else
1295                 ret = utf8_strncasecmp(um, name, entry);
1296
1297         if (ret < 0) {
1298                 /* Handle invalid character sequence as either an error
1299                  * or as an opaque byte sequence.
1300                  */
1301                 if (sb_has_strict_encoding(sb))
1302                         return -EINVAL;
1303
1304                 if (name->len != entry->len)
1305                         return 1;
1306
1307                 return !!memcmp(name->name, entry->name, name->len);
1308         }
1309
1310         return ret;
1311 }
1312
1313 void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
1314                                   struct fscrypt_str *cf_name)
1315 {
1316         int len;
1317
1318         if (!IS_CASEFOLDED(dir) || !dir->i_sb->s_encoding) {
1319                 cf_name->name = NULL;
1320                 return;
1321         }
1322
1323         cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
1324         if (!cf_name->name)
1325                 return;
1326
1327         len = utf8_casefold(dir->i_sb->s_encoding,
1328                             iname, cf_name->name,
1329                             EXT4_NAME_LEN);
1330         if (len <= 0) {
1331                 kfree(cf_name->name);
1332                 cf_name->name = NULL;
1333                 return;
1334         }
1335         cf_name->len = (unsigned) len;
1336
1337 }
1338 #endif
1339
1340 /*
1341  * Test whether a directory entry matches the filename being searched for.
1342  *
1343  * Return: %true if the directory entry matches, otherwise %false.
1344  */
1345 static inline bool ext4_match(const struct inode *parent,
1346                               const struct ext4_filename *fname,
1347                               const struct ext4_dir_entry_2 *de)
1348 {
1349         struct fscrypt_name f;
1350 #ifdef CONFIG_UNICODE
1351         const struct qstr entry = {.name = de->name, .len = de->name_len};
1352 #endif
1353
1354         if (!de->inode)
1355                 return false;
1356
1357         f.usr_fname = fname->usr_fname;
1358         f.disk_name = fname->disk_name;
1359 #ifdef CONFIG_FS_ENCRYPTION
1360         f.crypto_buf = fname->crypto_buf;
1361 #endif
1362
1363 #ifdef CONFIG_UNICODE
1364         if (parent->i_sb->s_encoding && IS_CASEFOLDED(parent)) {
1365                 if (fname->cf_name.name) {
1366                         struct qstr cf = {.name = fname->cf_name.name,
1367                                           .len = fname->cf_name.len};
1368                         return !ext4_ci_compare(parent, &cf, &entry, true);
1369                 }
1370                 return !ext4_ci_compare(parent, fname->usr_fname, &entry,
1371                                         false);
1372         }
1373 #endif
1374
1375         return fscrypt_match_name(&f, de->name, de->name_len);
1376 }
1377
1378 /*
1379  * Returns 0 if not found, -1 on failure, and 1 on success
1380  */
1381 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1382                     struct inode *dir, struct ext4_filename *fname,
1383                     unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1384 {
1385         struct ext4_dir_entry_2 * de;
1386         char * dlimit;
1387         int de_len;
1388
1389         de = (struct ext4_dir_entry_2 *)search_buf;
1390         dlimit = search_buf + buf_size;
1391         while ((char *) de < dlimit) {
1392                 /* this code is executed quadratically often */
1393                 /* do minimal checking `by hand' */
1394                 if ((char *) de + de->name_len <= dlimit &&
1395                     ext4_match(dir, fname, de)) {
1396                         /* found a match - just to be sure, do
1397                          * a full check */
1398                         if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
1399                                                  buf_size, offset))
1400                                 return -1;
1401                         *res_dir = de;
1402                         return 1;
1403                 }
1404                 /* prevent looping on a bad block */
1405                 de_len = ext4_rec_len_from_disk(de->rec_len,
1406                                                 dir->i_sb->s_blocksize);
1407                 if (de_len <= 0)
1408                         return -1;
1409                 offset += de_len;
1410                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1411         }
1412         return 0;
1413 }
1414
1415 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1416                                struct ext4_dir_entry *de)
1417 {
1418         struct super_block *sb = dir->i_sb;
1419
1420         if (!is_dx(dir))
1421                 return 0;
1422         if (block == 0)
1423                 return 1;
1424         if (de->inode == 0 &&
1425             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1426                         sb->s_blocksize)
1427                 return 1;
1428         return 0;
1429 }
1430
1431 /*
1432  *      __ext4_find_entry()
1433  *
1434  * finds an entry in the specified directory with the wanted name. It
1435  * returns the cache buffer in which the entry was found, and the entry
1436  * itself (as a parameter - res_dir). It does NOT read the inode of the
1437  * entry - you'll have to do that yourself if you want to.
1438  *
1439  * The returned buffer_head has ->b_count elevated.  The caller is expected
1440  * to brelse() it when appropriate.
1441  */
1442 static struct buffer_head *__ext4_find_entry(struct inode *dir,
1443                                              struct ext4_filename *fname,
1444                                              struct ext4_dir_entry_2 **res_dir,
1445                                              int *inlined)
1446 {
1447         struct super_block *sb;
1448         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1449         struct buffer_head *bh, *ret = NULL;
1450         ext4_lblk_t start, block;
1451         const u8 *name = fname->usr_fname->name;
1452         size_t ra_max = 0;      /* Number of bh's in the readahead
1453                                    buffer, bh_use[] */
1454         size_t ra_ptr = 0;      /* Current index into readahead
1455                                    buffer */
1456         ext4_lblk_t  nblocks;
1457         int i, namelen, retval;
1458
1459         *res_dir = NULL;
1460         sb = dir->i_sb;
1461         namelen = fname->usr_fname->len;
1462         if (namelen > EXT4_NAME_LEN)
1463                 return NULL;
1464
1465         if (ext4_has_inline_data(dir)) {
1466                 int has_inline_data = 1;
1467                 ret = ext4_find_inline_entry(dir, fname, res_dir,
1468                                              &has_inline_data);
1469                 if (has_inline_data) {
1470                         if (inlined)
1471                                 *inlined = 1;
1472                         goto cleanup_and_exit;
1473                 }
1474         }
1475
1476         if ((namelen <= 2) && (name[0] == '.') &&
1477             (name[1] == '.' || name[1] == '\0')) {
1478                 /*
1479                  * "." or ".." will only be in the first block
1480                  * NFS may look up ".."; "." should be handled by the VFS
1481                  */
1482                 block = start = 0;
1483                 nblocks = 1;
1484                 goto restart;
1485         }
1486         if (is_dx(dir)) {
1487                 ret = ext4_dx_find_entry(dir, fname, res_dir);
1488                 /*
1489                  * On success, or if the error was file not found,
1490                  * return.  Otherwise, fall back to doing a search the
1491                  * old fashioned way.
1492                  */
1493                 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1494                         goto cleanup_and_exit;
1495                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1496                                "falling back\n"));
1497                 ret = NULL;
1498         }
1499         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1500         if (!nblocks) {
1501                 ret = NULL;
1502                 goto cleanup_and_exit;
1503         }
1504         start = EXT4_I(dir)->i_dir_start_lookup;
1505         if (start >= nblocks)
1506                 start = 0;
1507         block = start;
1508 restart:
1509         do {
1510                 /*
1511                  * We deal with the read-ahead logic here.
1512                  */
1513                 cond_resched();
1514                 if (ra_ptr >= ra_max) {
1515                         /* Refill the readahead buffer */
1516                         ra_ptr = 0;
1517                         if (block < start)
1518                                 ra_max = start - block;
1519                         else
1520                                 ra_max = nblocks - block;
1521                         ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1522                         retval = ext4_bread_batch(dir, block, ra_max,
1523                                                   false /* wait */, bh_use);
1524                         if (retval) {
1525                                 ret = ERR_PTR(retval);
1526                                 ra_max = 0;
1527                                 goto cleanup_and_exit;
1528                         }
1529                 }
1530                 if ((bh = bh_use[ra_ptr++]) == NULL)
1531                         goto next;
1532                 wait_on_buffer(bh);
1533                 if (!buffer_uptodate(bh)) {
1534                         EXT4_ERROR_INODE_ERR(dir, EIO,
1535                                              "reading directory lblock %lu",
1536                                              (unsigned long) block);
1537                         brelse(bh);
1538                         ret = ERR_PTR(-EIO);
1539                         goto cleanup_and_exit;
1540                 }
1541                 if (!buffer_verified(bh) &&
1542                     !is_dx_internal_node(dir, block,
1543                                          (struct ext4_dir_entry *)bh->b_data) &&
1544                     !ext4_dirblock_csum_verify(dir, bh)) {
1545                         EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
1546                                              "checksumming directory "
1547                                              "block %lu", (unsigned long)block);
1548                         brelse(bh);
1549                         ret = ERR_PTR(-EFSBADCRC);
1550                         goto cleanup_and_exit;
1551                 }
1552                 set_buffer_verified(bh);
1553                 i = search_dirblock(bh, dir, fname,
1554                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1555                 if (i == 1) {
1556                         EXT4_I(dir)->i_dir_start_lookup = block;
1557                         ret = bh;
1558                         goto cleanup_and_exit;
1559                 } else {
1560                         brelse(bh);
1561                         if (i < 0)
1562                                 goto cleanup_and_exit;
1563                 }
1564         next:
1565                 if (++block >= nblocks)
1566                         block = 0;
1567         } while (block != start);
1568
1569         /*
1570          * If the directory has grown while we were searching, then
1571          * search the last part of the directory before giving up.
1572          */
1573         block = nblocks;
1574         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1575         if (block < nblocks) {
1576                 start = 0;
1577                 goto restart;
1578         }
1579
1580 cleanup_and_exit:
1581         /* Clean up the read-ahead blocks */
1582         for (; ra_ptr < ra_max; ra_ptr++)
1583                 brelse(bh_use[ra_ptr]);
1584         return ret;
1585 }
1586
1587 static struct buffer_head *ext4_find_entry(struct inode *dir,
1588                                            const struct qstr *d_name,
1589                                            struct ext4_dir_entry_2 **res_dir,
1590                                            int *inlined)
1591 {
1592         int err;
1593         struct ext4_filename fname;
1594         struct buffer_head *bh;
1595
1596         err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1597         if (err == -ENOENT)
1598                 return NULL;
1599         if (err)
1600                 return ERR_PTR(err);
1601
1602         bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
1603
1604         ext4_fname_free_filename(&fname);
1605         return bh;
1606 }
1607
1608 static struct buffer_head *ext4_lookup_entry(struct inode *dir,
1609                                              struct dentry *dentry,
1610                                              struct ext4_dir_entry_2 **res_dir)
1611 {
1612         int err;
1613         struct ext4_filename fname;
1614         struct buffer_head *bh;
1615
1616         err = ext4_fname_prepare_lookup(dir, dentry, &fname);
1617         generic_set_encrypted_ci_d_ops(dentry);
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         struct ext4_dir_entry_2 * de;
1743         struct buffer_head *bh;
1744
1745         bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL);
1746         if (IS_ERR(bh))
1747                 return ERR_CAST(bh);
1748         if (!bh)
1749                 return ERR_PTR(-ENOENT);
1750         ino = le32_to_cpu(de->inode);
1751         brelse(bh);
1752
1753         if (!ext4_valid_inum(child->d_sb, ino)) {
1754                 EXT4_ERROR_INODE(d_inode(child),
1755                                  "bad parent inode number: %u", ino);
1756                 return ERR_PTR(-EFSCORRUPTED);
1757         }
1758
1759         return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
1760 }
1761
1762 /*
1763  * Move count entries from end of map between two memory locations.
1764  * Returns pointer to last entry moved.
1765  */
1766 static struct ext4_dir_entry_2 *
1767 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1768                 unsigned blocksize)
1769 {
1770         unsigned rec_len = 0;
1771
1772         while (count--) {
1773                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1774                                                 (from + (map->offs<<2));
1775                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1776                 memcpy (to, de, rec_len);
1777                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1778                                 ext4_rec_len_to_disk(rec_len, blocksize);
1779                 de->inode = 0;
1780                 map++;
1781                 to += rec_len;
1782         }
1783         return (struct ext4_dir_entry_2 *) (to - rec_len);
1784 }
1785
1786 /*
1787  * Compact each dir entry in the range to the minimal rec_len.
1788  * Returns pointer to last entry in range.
1789  */
1790 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1791 {
1792         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1793         unsigned rec_len = 0;
1794
1795         prev = to = de;
1796         while ((char*)de < base + blocksize) {
1797                 next = ext4_next_entry(de, blocksize);
1798                 if (de->inode && de->name_len) {
1799                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1800                         if (de > to)
1801                                 memmove(to, de, rec_len);
1802                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1803                         prev = to;
1804                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1805                 }
1806                 de = next;
1807         }
1808         return prev;
1809 }
1810
1811 /*
1812  * Split a full leaf block to make room for a new dir entry.
1813  * Allocate a new block, and move entries so that they are approx. equally full.
1814  * Returns pointer to de in block into which the new entry will be inserted.
1815  */
1816 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1817                         struct buffer_head **bh,struct dx_frame *frame,
1818                         struct dx_hash_info *hinfo)
1819 {
1820         unsigned blocksize = dir->i_sb->s_blocksize;
1821         unsigned count, continued;
1822         struct buffer_head *bh2;
1823         ext4_lblk_t newblock;
1824         u32 hash2;
1825         struct dx_map_entry *map;
1826         char *data1 = (*bh)->b_data, *data2;
1827         unsigned split, move, size;
1828         struct ext4_dir_entry_2 *de = NULL, *de2;
1829         int     csum_size = 0;
1830         int     err = 0, i;
1831
1832         if (ext4_has_metadata_csum(dir->i_sb))
1833                 csum_size = sizeof(struct ext4_dir_entry_tail);
1834
1835         bh2 = ext4_append(handle, dir, &newblock);
1836         if (IS_ERR(bh2)) {
1837                 brelse(*bh);
1838                 *bh = NULL;
1839                 return (struct ext4_dir_entry_2 *) bh2;
1840         }
1841
1842         BUFFER_TRACE(*bh, "get_write_access");
1843         err = ext4_journal_get_write_access(handle, *bh);
1844         if (err)
1845                 goto journal_error;
1846
1847         BUFFER_TRACE(frame->bh, "get_write_access");
1848         err = ext4_journal_get_write_access(handle, frame->bh);
1849         if (err)
1850                 goto journal_error;
1851
1852         data2 = bh2->b_data;
1853
1854         /* create map in the end of data2 block */
1855         map = (struct dx_map_entry *) (data2 + blocksize);
1856         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1857                              blocksize, hinfo, map);
1858         map -= count;
1859         dx_sort_map(map, count);
1860         /* Ensure that neither split block is over half full */
1861         size = 0;
1862         move = 0;
1863         for (i = count-1; i >= 0; i--) {
1864                 /* is more than half of this entry in 2nd half of the block? */
1865                 if (size + map[i].size/2 > blocksize/2)
1866                         break;
1867                 size += map[i].size;
1868                 move++;
1869         }
1870         /*
1871          * map index at which we will split
1872          *
1873          * If the sum of active entries didn't exceed half the block size, just
1874          * split it in half by count; each resulting block will have at least
1875          * half the space free.
1876          */
1877         if (i > 0)
1878                 split = count - move;
1879         else
1880                 split = count/2;
1881
1882         hash2 = map[split].hash;
1883         continued = hash2 == map[split - 1].hash;
1884         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1885                         (unsigned long)dx_get_block(frame->at),
1886                                         hash2, split, count-split));
1887
1888         /* Fancy dance to stay within two buffers */
1889         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1890                               blocksize);
1891         de = dx_pack_dirents(data1, blocksize);
1892         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1893                                            (char *) de,
1894                                            blocksize);
1895         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1896                                             (char *) de2,
1897                                             blocksize);
1898         if (csum_size) {
1899                 ext4_initialize_dirent_tail(*bh, blocksize);
1900                 ext4_initialize_dirent_tail(bh2, blocksize);
1901         }
1902
1903         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1904                         blocksize, 1));
1905         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1906                         blocksize, 1));
1907
1908         /* Which block gets the new entry? */
1909         if (hinfo->hash >= hash2) {
1910                 swap(*bh, bh2);
1911                 de = de2;
1912         }
1913         dx_insert_block(frame, hash2 + continued, newblock);
1914         err = ext4_handle_dirty_dirblock(handle, dir, bh2);
1915         if (err)
1916                 goto journal_error;
1917         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1918         if (err)
1919                 goto journal_error;
1920         brelse(bh2);
1921         dxtrace(dx_show_index("frame", frame->entries));
1922         return de;
1923
1924 journal_error:
1925         brelse(*bh);
1926         brelse(bh2);
1927         *bh = NULL;
1928         ext4_std_error(dir->i_sb, err);
1929         return ERR_PTR(err);
1930 }
1931
1932 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1933                       struct buffer_head *bh,
1934                       void *buf, int buf_size,
1935                       struct ext4_filename *fname,
1936                       struct ext4_dir_entry_2 **dest_de)
1937 {
1938         struct ext4_dir_entry_2 *de;
1939         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1940         int nlen, rlen;
1941         unsigned int offset = 0;
1942         char *top;
1943
1944         de = (struct ext4_dir_entry_2 *)buf;
1945         top = buf + buf_size - reclen;
1946         while ((char *) de <= top) {
1947                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1948                                          buf, buf_size, offset))
1949                         return -EFSCORRUPTED;
1950                 if (ext4_match(dir, fname, de))
1951                         return -EEXIST;
1952                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1953                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1954                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1955                         break;
1956                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1957                 offset += rlen;
1958         }
1959         if ((char *) de > top)
1960                 return -ENOSPC;
1961
1962         *dest_de = de;
1963         return 0;
1964 }
1965
1966 void ext4_insert_dentry(struct inode *inode,
1967                         struct ext4_dir_entry_2 *de,
1968                         int buf_size,
1969                         struct ext4_filename *fname)
1970 {
1971
1972         int nlen, rlen;
1973
1974         nlen = EXT4_DIR_REC_LEN(de->name_len);
1975         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1976         if (de->inode) {
1977                 struct ext4_dir_entry_2 *de1 =
1978                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1979                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1980                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1981                 de = de1;
1982         }
1983         de->file_type = EXT4_FT_UNKNOWN;
1984         de->inode = cpu_to_le32(inode->i_ino);
1985         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1986         de->name_len = fname_len(fname);
1987         memcpy(de->name, fname_name(fname), fname_len(fname));
1988 }
1989
1990 /*
1991  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1992  * it points to a directory entry which is guaranteed to be large
1993  * enough for new directory entry.  If de is NULL, then
1994  * add_dirent_to_buf will attempt search the directory block for
1995  * space.  It will return -ENOSPC if no space is available, and -EIO
1996  * and -EEXIST if directory entry already exists.
1997  */
1998 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1999                              struct inode *dir,
2000                              struct inode *inode, struct ext4_dir_entry_2 *de,
2001                              struct buffer_head *bh)
2002 {
2003         unsigned int    blocksize = dir->i_sb->s_blocksize;
2004         int             csum_size = 0;
2005         int             err, err2;
2006
2007         if (ext4_has_metadata_csum(inode->i_sb))
2008                 csum_size = sizeof(struct ext4_dir_entry_tail);
2009
2010         if (!de) {
2011                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
2012                                         blocksize - csum_size, fname, &de);
2013                 if (err)
2014                         return err;
2015         }
2016         BUFFER_TRACE(bh, "get_write_access");
2017         err = ext4_journal_get_write_access(handle, bh);
2018         if (err) {
2019                 ext4_std_error(dir->i_sb, err);
2020                 return err;
2021         }
2022
2023         /* By now the buffer is marked for journaling */
2024         ext4_insert_dentry(inode, de, blocksize, fname);
2025
2026         /*
2027          * XXX shouldn't update any times until successful
2028          * completion of syscall, but too many callers depend
2029          * on this.
2030          *
2031          * XXX similarly, too many callers depend on
2032          * ext4_new_inode() setting the times, but error
2033          * recovery deletes the inode, so the worst that can
2034          * happen is that the times are slightly out of date
2035          * and/or different from the directory change time.
2036          */
2037         dir->i_mtime = dir->i_ctime = current_time(dir);
2038         ext4_update_dx_flag(dir);
2039         inode_inc_iversion(dir);
2040         err2 = ext4_mark_inode_dirty(handle, dir);
2041         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2042         err = ext4_handle_dirty_dirblock(handle, dir, bh);
2043         if (err)
2044                 ext4_std_error(dir->i_sb, err);
2045         return err ? err : err2;
2046 }
2047
2048 /*
2049  * This converts a one block unindexed directory to a 3 block indexed
2050  * directory, and adds the dentry to the indexed directory.
2051  */
2052 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
2053                             struct inode *dir,
2054                             struct inode *inode, struct buffer_head *bh)
2055 {
2056         struct buffer_head *bh2;
2057         struct dx_root  *root;
2058         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2059         struct dx_entry *entries;
2060         struct ext4_dir_entry_2 *de, *de2;
2061         char            *data2, *top;
2062         unsigned        len;
2063         int             retval;
2064         unsigned        blocksize;
2065         ext4_lblk_t  block;
2066         struct fake_dirent *fde;
2067         int csum_size = 0;
2068
2069         if (ext4_has_metadata_csum(inode->i_sb))
2070                 csum_size = sizeof(struct ext4_dir_entry_tail);
2071
2072         blocksize =  dir->i_sb->s_blocksize;
2073         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2074         BUFFER_TRACE(bh, "get_write_access");
2075         retval = ext4_journal_get_write_access(handle, bh);
2076         if (retval) {
2077                 ext4_std_error(dir->i_sb, retval);
2078                 brelse(bh);
2079                 return retval;
2080         }
2081         root = (struct dx_root *) bh->b_data;
2082
2083         /* The 0th block becomes the root, move the dirents out */
2084         fde = &root->dotdot;
2085         de = (struct ext4_dir_entry_2 *)((char *)fde +
2086                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2087         if ((char *) de >= (((char *) root) + blocksize)) {
2088                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2089                 brelse(bh);
2090                 return -EFSCORRUPTED;
2091         }
2092         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2093
2094         /* Allocate new block for the 0th block's dirents */
2095         bh2 = ext4_append(handle, dir, &block);
2096         if (IS_ERR(bh2)) {
2097                 brelse(bh);
2098                 return PTR_ERR(bh2);
2099         }
2100         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2101         data2 = bh2->b_data;
2102
2103         memcpy(data2, de, len);
2104         de = (struct ext4_dir_entry_2 *) data2;
2105         top = data2 + len;
2106         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2107                 de = de2;
2108         de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
2109                                            (char *) de, blocksize);
2110
2111         if (csum_size)
2112                 ext4_initialize_dirent_tail(bh2, blocksize);
2113
2114         /* Initialize the root; the dot dirents already exist */
2115         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2116         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2117                                            blocksize);
2118         memset (&root->info, 0, sizeof(root->info));
2119         root->info.info_length = sizeof(root->info);
2120         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2121         entries = root->entries;
2122         dx_set_block(entries, 1);
2123         dx_set_count(entries, 1);
2124         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2125
2126         /* Initialize as for dx_probe */
2127         fname->hinfo.hash_version = root->info.hash_version;
2128         if (fname->hinfo.hash_version <= DX_HASH_TEA)
2129                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2130         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2131         ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo);
2132
2133         memset(frames, 0, sizeof(frames));
2134         frame = frames;
2135         frame->entries = entries;
2136         frame->at = entries;
2137         frame->bh = bh;
2138
2139         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2140         if (retval)
2141                 goto out_frames;
2142         retval = ext4_handle_dirty_dirblock(handle, dir, bh2);
2143         if (retval)
2144                 goto out_frames;
2145
2146         de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2147         if (IS_ERR(de)) {
2148                 retval = PTR_ERR(de);
2149                 goto out_frames;
2150         }
2151
2152         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2153 out_frames:
2154         /*
2155          * Even if the block split failed, we have to properly write
2156          * out all the changes we did so far. Otherwise we can end up
2157          * with corrupted filesystem.
2158          */
2159         if (retval)
2160                 ext4_mark_inode_dirty(handle, dir);
2161         dx_release(frames);
2162         brelse(bh2);
2163         return retval;
2164 }
2165
2166 /*
2167  *      ext4_add_entry()
2168  *
2169  * adds a file entry to the specified directory, using the same
2170  * semantics as ext4_find_entry(). It returns NULL if it failed.
2171  *
2172  * NOTE!! The inode part of 'de' is left at 0 - which means you
2173  * may not sleep between calling this and putting something into
2174  * the entry, as someone else might have used it while you slept.
2175  */
2176 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2177                           struct inode *inode)
2178 {
2179         struct inode *dir = d_inode(dentry->d_parent);
2180         struct buffer_head *bh = NULL;
2181         struct ext4_dir_entry_2 *de;
2182         struct super_block *sb;
2183         struct ext4_filename fname;
2184         int     retval;
2185         int     dx_fallback=0;
2186         unsigned blocksize;
2187         ext4_lblk_t block, blocks;
2188         int     csum_size = 0;
2189
2190         if (ext4_has_metadata_csum(inode->i_sb))
2191                 csum_size = sizeof(struct ext4_dir_entry_tail);
2192
2193         sb = dir->i_sb;
2194         blocksize = sb->s_blocksize;
2195         if (!dentry->d_name.len)
2196                 return -EINVAL;
2197
2198         if (fscrypt_is_nokey_name(dentry))
2199                 return -ENOKEY;
2200
2201 #ifdef CONFIG_UNICODE
2202         if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
2203             sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))
2204                 return -EINVAL;
2205 #endif
2206
2207         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2208         if (retval)
2209                 return retval;
2210
2211         if (ext4_has_inline_data(dir)) {
2212                 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2213                 if (retval < 0)
2214                         goto out;
2215                 if (retval == 1) {
2216                         retval = 0;
2217                         goto out;
2218                 }
2219         }
2220
2221         if (is_dx(dir)) {
2222                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2223                 if (!retval || (retval != ERR_BAD_DX_DIR))
2224                         goto out;
2225                 /* Can we just ignore htree data? */
2226                 if (ext4_has_metadata_csum(sb)) {
2227                         EXT4_ERROR_INODE(dir,
2228                                 "Directory has corrupted htree index.");
2229                         retval = -EFSCORRUPTED;
2230                         goto out;
2231                 }
2232                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2233                 dx_fallback++;
2234                 retval = ext4_mark_inode_dirty(handle, dir);
2235                 if (unlikely(retval))
2236                         goto out;
2237         }
2238         blocks = dir->i_size >> sb->s_blocksize_bits;
2239         for (block = 0; block < blocks; block++) {
2240                 bh = ext4_read_dirblock(dir, block, DIRENT);
2241                 if (bh == NULL) {
2242                         bh = ext4_bread(handle, dir, block,
2243                                         EXT4_GET_BLOCKS_CREATE);
2244                         goto add_to_new_block;
2245                 }
2246                 if (IS_ERR(bh)) {
2247                         retval = PTR_ERR(bh);
2248                         bh = NULL;
2249                         goto out;
2250                 }
2251                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2252                                            NULL, bh);
2253                 if (retval != -ENOSPC)
2254                         goto out;
2255
2256                 if (blocks == 1 && !dx_fallback &&
2257                     ext4_has_feature_dir_index(sb)) {
2258                         retval = make_indexed_dir(handle, &fname, dir,
2259                                                   inode, bh);
2260                         bh = NULL; /* make_indexed_dir releases bh */
2261                         goto out;
2262                 }
2263                 brelse(bh);
2264         }
2265         bh = ext4_append(handle, dir, &block);
2266 add_to_new_block:
2267         if (IS_ERR(bh)) {
2268                 retval = PTR_ERR(bh);
2269                 bh = NULL;
2270                 goto out;
2271         }
2272         de = (struct ext4_dir_entry_2 *) bh->b_data;
2273         de->inode = 0;
2274         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2275
2276         if (csum_size)
2277                 ext4_initialize_dirent_tail(bh, blocksize);
2278
2279         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2280 out:
2281         ext4_fname_free_filename(&fname);
2282         brelse(bh);
2283         if (retval == 0)
2284                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2285         return retval;
2286 }
2287
2288 /*
2289  * Returns 0 for success, or a negative error value
2290  */
2291 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2292                              struct inode *dir, struct inode *inode)
2293 {
2294         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2295         struct dx_entry *entries, *at;
2296         struct buffer_head *bh;
2297         struct super_block *sb = dir->i_sb;
2298         struct ext4_dir_entry_2 *de;
2299         int restart;
2300         int err;
2301
2302 again:
2303         restart = 0;
2304         frame = dx_probe(fname, dir, NULL, frames);
2305         if (IS_ERR(frame))
2306                 return PTR_ERR(frame);
2307         entries = frame->entries;
2308         at = frame->at;
2309         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
2310         if (IS_ERR(bh)) {
2311                 err = PTR_ERR(bh);
2312                 bh = NULL;
2313                 goto cleanup;
2314         }
2315
2316         BUFFER_TRACE(bh, "get_write_access");
2317         err = ext4_journal_get_write_access(handle, bh);
2318         if (err)
2319                 goto journal_error;
2320
2321         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2322         if (err != -ENOSPC)
2323                 goto cleanup;
2324
2325         err = 0;
2326         /* Block full, should compress but for now just split */
2327         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2328                        dx_get_count(entries), dx_get_limit(entries)));
2329         /* Need to split index? */
2330         if (dx_get_count(entries) == dx_get_limit(entries)) {
2331                 ext4_lblk_t newblock;
2332                 int levels = frame - frames + 1;
2333                 unsigned int icount;
2334                 int add_level = 1;
2335                 struct dx_entry *entries2;
2336                 struct dx_node *node2;
2337                 struct buffer_head *bh2;
2338
2339                 while (frame > frames) {
2340                         if (dx_get_count((frame - 1)->entries) <
2341                             dx_get_limit((frame - 1)->entries)) {
2342                                 add_level = 0;
2343                                 break;
2344                         }
2345                         frame--; /* split higher index block */
2346                         at = frame->at;
2347                         entries = frame->entries;
2348                         restart = 1;
2349                 }
2350                 if (add_level && levels == ext4_dir_htree_level(sb)) {
2351                         ext4_warning(sb, "Directory (ino: %lu) index full, "
2352                                          "reach max htree level :%d",
2353                                          dir->i_ino, levels);
2354                         if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2355                                 ext4_warning(sb, "Large directory feature is "
2356                                                  "not enabled on this "
2357                                                  "filesystem");
2358                         }
2359                         err = -ENOSPC;
2360                         goto cleanup;
2361                 }
2362                 icount = dx_get_count(entries);
2363                 bh2 = ext4_append(handle, dir, &newblock);
2364                 if (IS_ERR(bh2)) {
2365                         err = PTR_ERR(bh2);
2366                         goto cleanup;
2367                 }
2368                 node2 = (struct dx_node *)(bh2->b_data);
2369                 entries2 = node2->entries;
2370                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2371                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2372                                                            sb->s_blocksize);
2373                 BUFFER_TRACE(frame->bh, "get_write_access");
2374                 err = ext4_journal_get_write_access(handle, frame->bh);
2375                 if (err)
2376                         goto journal_error;
2377                 if (!add_level) {
2378                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2379                         unsigned hash2 = dx_get_hash(entries + icount1);
2380                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2381                                        icount1, icount2));
2382
2383                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2384                         err = ext4_journal_get_write_access(handle,
2385                                                              (frame - 1)->bh);
2386                         if (err)
2387                                 goto journal_error;
2388
2389                         memcpy((char *) entries2, (char *) (entries + icount1),
2390                                icount2 * sizeof(struct dx_entry));
2391                         dx_set_count(entries, icount1);
2392                         dx_set_count(entries2, icount2);
2393                         dx_set_limit(entries2, dx_node_limit(dir));
2394
2395                         /* Which index block gets the new entry? */
2396                         if (at - entries >= icount1) {
2397                                 frame->at = at = at - entries - icount1 + entries2;
2398                                 frame->entries = entries = entries2;
2399                                 swap(frame->bh, bh2);
2400                         }
2401                         dx_insert_block((frame - 1), hash2, newblock);
2402                         dxtrace(dx_show_index("node", frame->entries));
2403                         dxtrace(dx_show_index("node",
2404                                ((struct dx_node *) bh2->b_data)->entries));
2405                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2406                         if (err)
2407                                 goto journal_error;
2408                         brelse (bh2);
2409                         err = ext4_handle_dirty_dx_node(handle, dir,
2410                                                    (frame - 1)->bh);
2411                         if (err)
2412                                 goto journal_error;
2413                         err = ext4_handle_dirty_dx_node(handle, dir,
2414                                                         frame->bh);
2415                         if (err)
2416                                 goto journal_error;
2417                 } else {
2418                         struct dx_root *dxroot;
2419                         memcpy((char *) entries2, (char *) entries,
2420                                icount * sizeof(struct dx_entry));
2421                         dx_set_limit(entries2, dx_node_limit(dir));
2422
2423                         /* Set up root */
2424                         dx_set_count(entries, 1);
2425                         dx_set_block(entries + 0, newblock);
2426                         dxroot = (struct dx_root *)frames[0].bh->b_data;
2427                         dxroot->info.indirect_levels += 1;
2428                         dxtrace(printk(KERN_DEBUG
2429                                        "Creating %d level index...\n",
2430                                        dxroot->info.indirect_levels));
2431                         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2432                         if (err)
2433                                 goto journal_error;
2434                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2435                         brelse(bh2);
2436                         restart = 1;
2437                         goto journal_error;
2438                 }
2439         }
2440         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2441         if (IS_ERR(de)) {
2442                 err = PTR_ERR(de);
2443                 goto cleanup;
2444         }
2445         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2446         goto cleanup;
2447
2448 journal_error:
2449         ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2450 cleanup:
2451         brelse(bh);
2452         dx_release(frames);
2453         /* @restart is true means htree-path has been changed, we need to
2454          * repeat dx_probe() to find out valid htree-path
2455          */
2456         if (restart && err == 0)
2457                 goto again;
2458         return err;
2459 }
2460
2461 /*
2462  * ext4_generic_delete_entry deletes a directory entry by merging it
2463  * with the previous entry
2464  */
2465 int ext4_generic_delete_entry(struct inode *dir,
2466                               struct ext4_dir_entry_2 *de_del,
2467                               struct buffer_head *bh,
2468                               void *entry_buf,
2469                               int buf_size,
2470                               int csum_size)
2471 {
2472         struct ext4_dir_entry_2 *de, *pde;
2473         unsigned int blocksize = dir->i_sb->s_blocksize;
2474         int i;
2475
2476         i = 0;
2477         pde = NULL;
2478         de = (struct ext4_dir_entry_2 *)entry_buf;
2479         while (i < buf_size - csum_size) {
2480                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2481                                          entry_buf, buf_size, i))
2482                         return -EFSCORRUPTED;
2483                 if (de == de_del)  {
2484                         if (pde)
2485                                 pde->rec_len = ext4_rec_len_to_disk(
2486                                         ext4_rec_len_from_disk(pde->rec_len,
2487                                                                blocksize) +
2488                                         ext4_rec_len_from_disk(de->rec_len,
2489                                                                blocksize),
2490                                         blocksize);
2491                         else
2492                                 de->inode = 0;
2493                         inode_inc_iversion(dir);
2494                         return 0;
2495                 }
2496                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2497                 pde = de;
2498                 de = ext4_next_entry(de, blocksize);
2499         }
2500         return -ENOENT;
2501 }
2502
2503 static int ext4_delete_entry(handle_t *handle,
2504                              struct inode *dir,
2505                              struct ext4_dir_entry_2 *de_del,
2506                              struct buffer_head *bh)
2507 {
2508         int err, csum_size = 0;
2509
2510         if (ext4_has_inline_data(dir)) {
2511                 int has_inline_data = 1;
2512                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2513                                                &has_inline_data);
2514                 if (has_inline_data)
2515                         return err;
2516         }
2517
2518         if (ext4_has_metadata_csum(dir->i_sb))
2519                 csum_size = sizeof(struct ext4_dir_entry_tail);
2520
2521         BUFFER_TRACE(bh, "get_write_access");
2522         err = ext4_journal_get_write_access(handle, bh);
2523         if (unlikely(err))
2524                 goto out;
2525
2526         err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data,
2527                                         dir->i_sb->s_blocksize, csum_size);
2528         if (err)
2529                 goto out;
2530
2531         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2532         err = ext4_handle_dirty_dirblock(handle, dir, bh);
2533         if (unlikely(err))
2534                 goto out;
2535
2536         return 0;
2537 out:
2538         if (err != -ENOENT)
2539                 ext4_std_error(dir->i_sb, err);
2540         return err;
2541 }
2542
2543 /*
2544  * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2545  * since this indicates that nlinks count was previously 1 to avoid overflowing
2546  * the 16-bit i_links_count field on disk.  Directories with i_nlink == 1 mean
2547  * that subdirectory link counts are not being maintained accurately.
2548  *
2549  * The caller has already checked for i_nlink overflow in case the DIR_LINK
2550  * feature is not enabled and returned -EMLINK.  The is_dx() check is a proxy
2551  * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2552  * on regular files) and to avoid creating huge/slow non-HTREE directories.
2553  */
2554 static void ext4_inc_count(struct inode *inode)
2555 {
2556         inc_nlink(inode);
2557         if (is_dx(inode) &&
2558             (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2559                 set_nlink(inode, 1);
2560 }
2561
2562 /*
2563  * If a directory had nlink == 1, then we should let it be 1. This indicates
2564  * directory has >EXT4_LINK_MAX subdirs.
2565  */
2566 static void ext4_dec_count(struct inode *inode)
2567 {
2568         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2569                 drop_nlink(inode);
2570 }
2571
2572
2573 /*
2574  * Add non-directory inode to a directory. On success, the inode reference is
2575  * consumed by dentry is instantiation. This is also indicated by clearing of
2576  * *inodep pointer. On failure, the caller is responsible for dropping the
2577  * inode reference in the safe context.
2578  */
2579 static int ext4_add_nondir(handle_t *handle,
2580                 struct dentry *dentry, struct inode **inodep)
2581 {
2582         struct inode *dir = d_inode(dentry->d_parent);
2583         struct inode *inode = *inodep;
2584         int err = ext4_add_entry(handle, dentry, inode);
2585         if (!err) {
2586                 err = ext4_mark_inode_dirty(handle, inode);
2587                 if (IS_DIRSYNC(dir))
2588                         ext4_handle_sync(handle);
2589                 d_instantiate_new(dentry, inode);
2590                 *inodep = NULL;
2591                 return err;
2592         }
2593         drop_nlink(inode);
2594         ext4_orphan_add(handle, inode);
2595         unlock_new_inode(inode);
2596         return err;
2597 }
2598
2599 /*
2600  * By the time this is called, we already have created
2601  * the directory cache entry for the new file, but it
2602  * is so far negative - it has no inode.
2603  *
2604  * If the create succeeds, we fill in the inode information
2605  * with d_instantiate().
2606  */
2607 static int ext4_create(struct user_namespace *mnt_userns, struct inode *dir,
2608                        struct dentry *dentry, umode_t mode, bool excl)
2609 {
2610         handle_t *handle;
2611         struct inode *inode;
2612         int err, credits, retries = 0;
2613
2614         err = dquot_initialize(dir);
2615         if (err)
2616                 return err;
2617
2618         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2619                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2620 retry:
2621         inode = ext4_new_inode_start_handle(mnt_userns, dir, mode, &dentry->d_name,
2622                                             0, NULL, EXT4_HT_DIR, credits);
2623         handle = ext4_journal_current_handle();
2624         err = PTR_ERR(inode);
2625         if (!IS_ERR(inode)) {
2626                 inode->i_op = &ext4_file_inode_operations;
2627                 inode->i_fop = &ext4_file_operations;
2628                 ext4_set_aops(inode);
2629                 err = ext4_add_nondir(handle, dentry, &inode);
2630                 if (!err)
2631                         ext4_fc_track_create(handle, dentry);
2632         }
2633         if (handle)
2634                 ext4_journal_stop(handle);
2635         if (!IS_ERR_OR_NULL(inode))
2636                 iput(inode);
2637         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2638                 goto retry;
2639         return err;
2640 }
2641
2642 static int ext4_mknod(struct user_namespace *mnt_userns, struct inode *dir,
2643                       struct dentry *dentry, umode_t mode, dev_t rdev)
2644 {
2645         handle_t *handle;
2646         struct inode *inode;
2647         int err, credits, retries = 0;
2648
2649         err = dquot_initialize(dir);
2650         if (err)
2651                 return err;
2652
2653         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2654                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2655 retry:
2656         inode = ext4_new_inode_start_handle(mnt_userns, dir, mode, &dentry->d_name,
2657                                             0, NULL, EXT4_HT_DIR, credits);
2658         handle = ext4_journal_current_handle();
2659         err = PTR_ERR(inode);
2660         if (!IS_ERR(inode)) {
2661                 init_special_inode(inode, inode->i_mode, rdev);
2662                 inode->i_op = &ext4_special_inode_operations;
2663                 err = ext4_add_nondir(handle, dentry, &inode);
2664                 if (!err)
2665                         ext4_fc_track_create(handle, dentry);
2666         }
2667         if (handle)
2668                 ext4_journal_stop(handle);
2669         if (!IS_ERR_OR_NULL(inode))
2670                 iput(inode);
2671         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2672                 goto retry;
2673         return err;
2674 }
2675
2676 static int ext4_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
2677                         struct dentry *dentry, umode_t mode)
2678 {
2679         handle_t *handle;
2680         struct inode *inode;
2681         int err, retries = 0;
2682
2683         err = dquot_initialize(dir);
2684         if (err)
2685                 return err;
2686
2687 retry:
2688         inode = ext4_new_inode_start_handle(mnt_userns, dir, mode,
2689                                             NULL, 0, NULL,
2690                                             EXT4_HT_DIR,
2691                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2692                           4 + EXT4_XATTR_TRANS_BLOCKS);
2693         handle = ext4_journal_current_handle();
2694         err = PTR_ERR(inode);
2695         if (!IS_ERR(inode)) {
2696                 inode->i_op = &ext4_file_inode_operations;
2697                 inode->i_fop = &ext4_file_operations;
2698                 ext4_set_aops(inode);
2699                 d_tmpfile(dentry, inode);
2700                 err = ext4_orphan_add(handle, inode);
2701                 if (err)
2702                         goto err_unlock_inode;
2703                 mark_inode_dirty(inode);
2704                 unlock_new_inode(inode);
2705         }
2706         if (handle)
2707                 ext4_journal_stop(handle);
2708         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2709                 goto retry;
2710         return err;
2711 err_unlock_inode:
2712         ext4_journal_stop(handle);
2713         unlock_new_inode(inode);
2714         return err;
2715 }
2716
2717 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2718                           struct ext4_dir_entry_2 *de,
2719                           int blocksize, int csum_size,
2720                           unsigned int parent_ino, int dotdot_real_len)
2721 {
2722         de->inode = cpu_to_le32(inode->i_ino);
2723         de->name_len = 1;
2724         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2725                                            blocksize);
2726         strcpy(de->name, ".");
2727         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2728
2729         de = ext4_next_entry(de, blocksize);
2730         de->inode = cpu_to_le32(parent_ino);
2731         de->name_len = 2;
2732         if (!dotdot_real_len)
2733                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2734                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2735                                         blocksize);
2736         else
2737                 de->rec_len = ext4_rec_len_to_disk(
2738                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2739         strcpy(de->name, "..");
2740         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2741
2742         return ext4_next_entry(de, blocksize);
2743 }
2744
2745 int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2746                              struct inode *inode)
2747 {
2748         struct buffer_head *dir_block = NULL;
2749         struct ext4_dir_entry_2 *de;
2750         ext4_lblk_t block = 0;
2751         unsigned int blocksize = dir->i_sb->s_blocksize;
2752         int csum_size = 0;
2753         int err;
2754
2755         if (ext4_has_metadata_csum(dir->i_sb))
2756                 csum_size = sizeof(struct ext4_dir_entry_tail);
2757
2758         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2759                 err = ext4_try_create_inline_dir(handle, dir, inode);
2760                 if (err < 0 && err != -ENOSPC)
2761                         goto out;
2762                 if (!err)
2763                         goto out;
2764         }
2765
2766         inode->i_size = 0;
2767         dir_block = ext4_append(handle, inode, &block);
2768         if (IS_ERR(dir_block))
2769                 return PTR_ERR(dir_block);
2770         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2771         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2772         set_nlink(inode, 2);
2773         if (csum_size)
2774                 ext4_initialize_dirent_tail(dir_block, blocksize);
2775
2776         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2777         err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
2778         if (err)
2779                 goto out;
2780         set_buffer_verified(dir_block);
2781 out:
2782         brelse(dir_block);
2783         return err;
2784 }
2785
2786 static int ext4_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
2787                       struct dentry *dentry, umode_t mode)
2788 {
2789         handle_t *handle;
2790         struct inode *inode;
2791         int err, err2 = 0, credits, retries = 0;
2792
2793         if (EXT4_DIR_LINK_MAX(dir))
2794                 return -EMLINK;
2795
2796         err = dquot_initialize(dir);
2797         if (err)
2798                 return err;
2799
2800         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2801                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2802 retry:
2803         inode = ext4_new_inode_start_handle(mnt_userns, dir, S_IFDIR | mode,
2804                                             &dentry->d_name,
2805                                             0, NULL, EXT4_HT_DIR, credits);
2806         handle = ext4_journal_current_handle();
2807         err = PTR_ERR(inode);
2808         if (IS_ERR(inode))
2809                 goto out_stop;
2810
2811         inode->i_op = &ext4_dir_inode_operations;
2812         inode->i_fop = &ext4_dir_operations;
2813         err = ext4_init_new_dir(handle, dir, inode);
2814         if (err)
2815                 goto out_clear_inode;
2816         err = ext4_mark_inode_dirty(handle, inode);
2817         if (!err)
2818                 err = ext4_add_entry(handle, dentry, inode);
2819         if (err) {
2820 out_clear_inode:
2821                 clear_nlink(inode);
2822                 ext4_orphan_add(handle, inode);
2823                 unlock_new_inode(inode);
2824                 err2 = ext4_mark_inode_dirty(handle, inode);
2825                 if (unlikely(err2))
2826                         err = err2;
2827                 ext4_journal_stop(handle);
2828                 iput(inode);
2829                 goto out_retry;
2830         }
2831         ext4_inc_count(dir);
2832
2833         ext4_update_dx_flag(dir);
2834         err = ext4_mark_inode_dirty(handle, dir);
2835         if (err)
2836                 goto out_clear_inode;
2837         d_instantiate_new(dentry, inode);
2838         ext4_fc_track_create(handle, dentry);
2839         if (IS_DIRSYNC(dir))
2840                 ext4_handle_sync(handle);
2841
2842 out_stop:
2843         if (handle)
2844                 ext4_journal_stop(handle);
2845 out_retry:
2846         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2847                 goto retry;
2848         return err;
2849 }
2850
2851 /*
2852  * routine to check that the specified directory is empty (for rmdir)
2853  */
2854 bool ext4_empty_dir(struct inode *inode)
2855 {
2856         unsigned int offset;
2857         struct buffer_head *bh;
2858         struct ext4_dir_entry_2 *de;
2859         struct super_block *sb;
2860
2861         if (ext4_has_inline_data(inode)) {
2862                 int has_inline_data = 1;
2863                 int ret;
2864
2865                 ret = empty_inline_dir(inode, &has_inline_data);
2866                 if (has_inline_data)
2867                         return ret;
2868         }
2869
2870         sb = inode->i_sb;
2871         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2872                 EXT4_ERROR_INODE(inode, "invalid size");
2873                 return true;
2874         }
2875         /* The first directory block must not be a hole,
2876          * so treat it as DIRENT_HTREE
2877          */
2878         bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
2879         if (IS_ERR(bh))
2880                 return true;
2881
2882         de = (struct ext4_dir_entry_2 *) bh->b_data;
2883         if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
2884                                  0) ||
2885             le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
2886                 ext4_warning_inode(inode, "directory missing '.'");
2887                 brelse(bh);
2888                 return true;
2889         }
2890         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2891         de = ext4_next_entry(de, sb->s_blocksize);
2892         if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
2893                                  offset) ||
2894             le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
2895                 ext4_warning_inode(inode, "directory missing '..'");
2896                 brelse(bh);
2897                 return true;
2898         }
2899         offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2900         while (offset < inode->i_size) {
2901                 if (!(offset & (sb->s_blocksize - 1))) {
2902                         unsigned int lblock;
2903                         brelse(bh);
2904                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2905                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2906                         if (bh == NULL) {
2907                                 offset += sb->s_blocksize;
2908                                 continue;
2909                         }
2910                         if (IS_ERR(bh))
2911                                 return true;
2912                 }
2913                 de = (struct ext4_dir_entry_2 *) (bh->b_data +
2914                                         (offset & (sb->s_blocksize - 1)));
2915                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2916                                          bh->b_data, bh->b_size, offset)) {
2917                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2918                         continue;
2919                 }
2920                 if (le32_to_cpu(de->inode)) {
2921                         brelse(bh);
2922                         return false;
2923                 }
2924                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2925         }
2926         brelse(bh);
2927         return true;
2928 }
2929
2930 /*
2931  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2932  * such inodes, starting at the superblock, in case we crash before the
2933  * file is closed/deleted, or in case the inode truncate spans multiple
2934  * transactions and the last transaction is not recovered after a crash.
2935  *
2936  * At filesystem recovery time, we walk this list deleting unlinked
2937  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2938  *
2939  * Orphan list manipulation functions must be called under i_mutex unless
2940  * we are just creating the inode or deleting it.
2941  */
2942 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2943 {
2944         struct super_block *sb = inode->i_sb;
2945         struct ext4_sb_info *sbi = EXT4_SB(sb);
2946         struct ext4_iloc iloc;
2947         int err = 0, rc;
2948         bool dirty = false;
2949
2950         if (!sbi->s_journal || is_bad_inode(inode))
2951                 return 0;
2952
2953         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2954                      !inode_is_locked(inode));
2955         /*
2956          * Exit early if inode already is on orphan list. This is a big speedup
2957          * since we don't have to contend on the global s_orphan_lock.
2958          */
2959         if (!list_empty(&EXT4_I(inode)->i_orphan))
2960                 return 0;
2961
2962         /*
2963          * Orphan handling is only valid for files with data blocks
2964          * being truncated, or files being unlinked. Note that we either
2965          * hold i_mutex, or the inode can not be referenced from outside,
2966          * so i_nlink should not be bumped due to race
2967          */
2968         ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2969                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2970
2971         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2972         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2973         if (err)
2974                 goto out;
2975
2976         err = ext4_reserve_inode_write(handle, inode, &iloc);
2977         if (err)
2978                 goto out;
2979
2980         mutex_lock(&sbi->s_orphan_lock);
2981         /*
2982          * Due to previous errors inode may be already a part of on-disk
2983          * orphan list. If so skip on-disk list modification.
2984          */
2985         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2986             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2987                 /* Insert this inode at the head of the on-disk orphan list */
2988                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2989                 lock_buffer(sbi->s_sbh);
2990                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2991                 ext4_superblock_csum_set(sb);
2992                 unlock_buffer(sbi->s_sbh);
2993                 dirty = true;
2994         }
2995         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2996         mutex_unlock(&sbi->s_orphan_lock);
2997
2998         if (dirty) {
2999                 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
3000                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
3001                 if (!err)
3002                         err = rc;
3003                 if (err) {
3004                         /*
3005                          * We have to remove inode from in-memory list if
3006                          * addition to on disk orphan list failed. Stray orphan
3007                          * list entries can cause panics at unmount time.
3008                          */
3009                         mutex_lock(&sbi->s_orphan_lock);
3010                         list_del_init(&EXT4_I(inode)->i_orphan);
3011                         mutex_unlock(&sbi->s_orphan_lock);
3012                 }
3013         } else
3014                 brelse(iloc.bh);
3015
3016         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
3017         jbd_debug(4, "orphan inode %lu will point to %d\n",
3018                         inode->i_ino, NEXT_ORPHAN(inode));
3019 out:
3020         ext4_std_error(sb, err);
3021         return err;
3022 }
3023
3024 /*
3025  * ext4_orphan_del() removes an unlinked or truncated inode from the list
3026  * of such inodes stored on disk, because it is finally being cleaned up.
3027  */
3028 int ext4_orphan_del(handle_t *handle, struct inode *inode)
3029 {
3030         struct list_head *prev;
3031         struct ext4_inode_info *ei = EXT4_I(inode);
3032         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3033         __u32 ino_next;
3034         struct ext4_iloc iloc;
3035         int err = 0;
3036
3037         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
3038                 return 0;
3039
3040         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
3041                      !inode_is_locked(inode));
3042         /* Do this quick check before taking global s_orphan_lock. */
3043         if (list_empty(&ei->i_orphan))
3044                 return 0;
3045
3046         if (handle) {
3047                 /* Grab inode buffer early before taking global s_orphan_lock */
3048                 err = ext4_reserve_inode_write(handle, inode, &iloc);
3049         }
3050
3051         mutex_lock(&sbi->s_orphan_lock);
3052         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
3053
3054         prev = ei->i_orphan.prev;
3055         list_del_init(&ei->i_orphan);
3056
3057         /* If we're on an error path, we may not have a valid
3058          * transaction handle with which to update the orphan list on
3059          * disk, but we still need to remove the inode from the linked
3060          * list in memory. */
3061         if (!handle || err) {
3062                 mutex_unlock(&sbi->s_orphan_lock);
3063                 goto out_err;
3064         }
3065
3066         ino_next = NEXT_ORPHAN(inode);
3067         if (prev == &sbi->s_orphan) {
3068                 jbd_debug(4, "superblock will point to %u\n", ino_next);
3069                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
3070                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
3071                 if (err) {
3072                         mutex_unlock(&sbi->s_orphan_lock);
3073                         goto out_brelse;
3074                 }
3075                 lock_buffer(sbi->s_sbh);
3076                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
3077                 ext4_superblock_csum_set(inode->i_sb);
3078                 unlock_buffer(sbi->s_sbh);
3079                 mutex_unlock(&sbi->s_orphan_lock);
3080                 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
3081         } else {
3082                 struct ext4_iloc iloc2;
3083                 struct inode *i_prev =
3084                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
3085
3086                 jbd_debug(4, "orphan inode %lu will point to %u\n",
3087                           i_prev->i_ino, ino_next);
3088                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
3089                 if (err) {
3090                         mutex_unlock(&sbi->s_orphan_lock);
3091                         goto out_brelse;
3092                 }
3093                 NEXT_ORPHAN(i_prev) = ino_next;
3094                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
3095                 mutex_unlock(&sbi->s_orphan_lock);
3096         }
3097         if (err)
3098                 goto out_brelse;
3099         NEXT_ORPHAN(inode) = 0;
3100         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
3101 out_err:
3102         ext4_std_error(inode->i_sb, err);
3103         return err;
3104
3105 out_brelse:
3106         brelse(iloc.bh);
3107         goto out_err;
3108 }
3109
3110 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3111 {
3112         int retval;
3113         struct inode *inode;
3114         struct buffer_head *bh;
3115         struct ext4_dir_entry_2 *de;
3116         handle_t *handle = NULL;
3117
3118         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3119                 return -EIO;
3120
3121         /* Initialize quotas before so that eventual writes go in
3122          * separate transaction */
3123         retval = dquot_initialize(dir);
3124         if (retval)
3125                 return retval;
3126         retval = dquot_initialize(d_inode(dentry));
3127         if (retval)
3128                 return retval;
3129
3130         retval = -ENOENT;
3131         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3132         if (IS_ERR(bh))
3133                 return PTR_ERR(bh);
3134         if (!bh)
3135                 goto end_rmdir;
3136
3137         inode = d_inode(dentry);
3138
3139         retval = -EFSCORRUPTED;
3140         if (le32_to_cpu(de->inode) != inode->i_ino)
3141                 goto end_rmdir;
3142
3143         retval = -ENOTEMPTY;
3144         if (!ext4_empty_dir(inode))
3145                 goto end_rmdir;
3146
3147         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3148                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3149         if (IS_ERR(handle)) {
3150                 retval = PTR_ERR(handle);
3151                 handle = NULL;
3152                 goto end_rmdir;
3153         }
3154
3155         if (IS_DIRSYNC(dir))
3156                 ext4_handle_sync(handle);
3157
3158         retval = ext4_delete_entry(handle, dir, de, bh);
3159         if (retval)
3160                 goto end_rmdir;
3161         if (!EXT4_DIR_LINK_EMPTY(inode))
3162                 ext4_warning_inode(inode,
3163                              "empty directory '%.*s' has too many links (%u)",
3164                              dentry->d_name.len, dentry->d_name.name,
3165                              inode->i_nlink);
3166         inode_inc_iversion(inode);
3167         clear_nlink(inode);
3168         /* There's no need to set i_disksize: the fact that i_nlink is
3169          * zero will ensure that the right thing happens during any
3170          * recovery. */
3171         inode->i_size = 0;
3172         ext4_orphan_add(handle, inode);
3173         inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
3174         retval = ext4_mark_inode_dirty(handle, inode);
3175         if (retval)
3176                 goto end_rmdir;
3177         ext4_dec_count(dir);
3178         ext4_update_dx_flag(dir);
3179         ext4_fc_track_unlink(handle, dentry);
3180         retval = ext4_mark_inode_dirty(handle, dir);
3181
3182 #ifdef CONFIG_UNICODE
3183         /* VFS negative dentries are incompatible with Encoding and
3184          * Case-insensitiveness. Eventually we'll want avoid
3185          * invalidating the dentries here, alongside with returning the
3186          * negative dentries at ext4_lookup(), when it is better
3187          * supported by the VFS for the CI case.
3188          */
3189         if (IS_CASEFOLDED(dir))
3190                 d_invalidate(dentry);
3191 #endif
3192
3193 end_rmdir:
3194         brelse(bh);
3195         if (handle)
3196                 ext4_journal_stop(handle);
3197         return retval;
3198 }
3199
3200 int __ext4_unlink(handle_t *handle, struct inode *dir, const struct qstr *d_name,
3201                   struct inode *inode)
3202 {
3203         int retval = -ENOENT;
3204         struct buffer_head *bh;
3205         struct ext4_dir_entry_2 *de;
3206         int skip_remove_dentry = 0;
3207
3208         bh = ext4_find_entry(dir, d_name, &de, NULL);
3209         if (IS_ERR(bh))
3210                 return PTR_ERR(bh);
3211
3212         if (!bh)
3213                 return -ENOENT;
3214
3215         if (le32_to_cpu(de->inode) != inode->i_ino) {
3216                 /*
3217                  * It's okay if we find dont find dentry which matches
3218                  * the inode. That's because it might have gotten
3219                  * renamed to a different inode number
3220                  */
3221                 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
3222                         skip_remove_dentry = 1;
3223                 else
3224                         goto out;
3225         }
3226
3227         if (IS_DIRSYNC(dir))
3228                 ext4_handle_sync(handle);
3229
3230         if (!skip_remove_dentry) {
3231                 retval = ext4_delete_entry(handle, dir, de, bh);
3232                 if (retval)
3233                         goto out;
3234                 dir->i_ctime = dir->i_mtime = current_time(dir);
3235                 ext4_update_dx_flag(dir);
3236                 retval = ext4_mark_inode_dirty(handle, dir);
3237                 if (retval)
3238                         goto out;
3239         } else {
3240                 retval = 0;
3241         }
3242         if (inode->i_nlink == 0)
3243                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3244                                    d_name->len, d_name->name);
3245         else
3246                 drop_nlink(inode);
3247         if (!inode->i_nlink)
3248                 ext4_orphan_add(handle, inode);
3249         inode->i_ctime = current_time(inode);
3250         retval = ext4_mark_inode_dirty(handle, inode);
3251
3252 out:
3253         brelse(bh);
3254         return retval;
3255 }
3256
3257 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3258 {
3259         handle_t *handle;
3260         int retval;
3261
3262         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3263                 return -EIO;
3264
3265         trace_ext4_unlink_enter(dir, dentry);
3266         /*
3267          * Initialize quotas before so that eventual writes go
3268          * in separate transaction
3269          */
3270         retval = dquot_initialize(dir);
3271         if (retval)
3272                 goto out_trace;
3273         retval = dquot_initialize(d_inode(dentry));
3274         if (retval)
3275                 goto out_trace;
3276
3277         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3278                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3279         if (IS_ERR(handle)) {
3280                 retval = PTR_ERR(handle);
3281                 goto out_trace;
3282         }
3283
3284         retval = __ext4_unlink(handle, dir, &dentry->d_name, d_inode(dentry));
3285         if (!retval)
3286                 ext4_fc_track_unlink(handle, dentry);
3287 #ifdef CONFIG_UNICODE
3288         /* VFS negative dentries are incompatible with Encoding and
3289          * Case-insensitiveness. Eventually we'll want avoid
3290          * invalidating the dentries here, alongside with returning the
3291          * negative dentries at ext4_lookup(), when it is  better
3292          * supported by the VFS for the CI case.
3293          */
3294         if (IS_CASEFOLDED(dir))
3295                 d_invalidate(dentry);
3296 #endif
3297         if (handle)
3298                 ext4_journal_stop(handle);
3299
3300 out_trace:
3301         trace_ext4_unlink_exit(dentry, retval);
3302         return retval;
3303 }
3304
3305 static int ext4_symlink(struct user_namespace *mnt_userns, struct inode *dir,
3306                         struct dentry *dentry, const char *symname)
3307 {
3308         handle_t *handle;
3309         struct inode *inode;
3310         int err, len = strlen(symname);
3311         int credits;
3312         struct fscrypt_str disk_link;
3313
3314         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3315                 return -EIO;
3316
3317         err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3318                                       &disk_link);
3319         if (err)
3320                 return err;
3321
3322         err = dquot_initialize(dir);
3323         if (err)
3324                 return err;
3325
3326         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3327                 /*
3328                  * For non-fast symlinks, we just allocate inode and put it on
3329                  * orphan list in the first transaction => we need bitmap,
3330                  * group descriptor, sb, inode block, quota blocks, and
3331                  * possibly selinux xattr blocks.
3332                  */
3333                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3334                           EXT4_XATTR_TRANS_BLOCKS;
3335         } else {
3336                 /*
3337                  * Fast symlink. We have to add entry to directory
3338                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3339                  * allocate new inode (bitmap, group descriptor, inode block,
3340                  * quota blocks, sb is already counted in previous macros).
3341                  */
3342                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3343                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3344         }
3345
3346         inode = ext4_new_inode_start_handle(mnt_userns, dir, S_IFLNK|S_IRWXUGO,
3347                                             &dentry->d_name, 0, NULL,
3348                                             EXT4_HT_DIR, credits);
3349         handle = ext4_journal_current_handle();
3350         if (IS_ERR(inode)) {
3351                 if (handle)
3352                         ext4_journal_stop(handle);
3353                 return PTR_ERR(inode);
3354         }
3355
3356         if (IS_ENCRYPTED(inode)) {
3357                 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3358                 if (err)
3359                         goto err_drop_inode;
3360                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3361         }
3362
3363         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3364                 if (!IS_ENCRYPTED(inode))
3365                         inode->i_op = &ext4_symlink_inode_operations;
3366                 inode_nohighmem(inode);
3367                 ext4_set_aops(inode);
3368                 /*
3369                  * We cannot call page_symlink() with transaction started
3370                  * because it calls into ext4_write_begin() which can wait
3371                  * for transaction commit if we are running out of space
3372                  * and thus we deadlock. So we have to stop transaction now
3373                  * and restart it when symlink contents is written.
3374                  *
3375                  * To keep fs consistent in case of crash, we have to put inode
3376                  * to orphan list in the mean time.
3377                  */
3378                 drop_nlink(inode);
3379                 err = ext4_orphan_add(handle, inode);
3380                 if (handle)
3381                         ext4_journal_stop(handle);
3382                 handle = NULL;
3383                 if (err)
3384                         goto err_drop_inode;
3385                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3386                 if (err)
3387                         goto err_drop_inode;
3388                 /*
3389                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3390                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3391                  */
3392                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3393                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3394                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3395                 if (IS_ERR(handle)) {
3396                         err = PTR_ERR(handle);
3397                         handle = NULL;
3398                         goto err_drop_inode;
3399                 }
3400                 set_nlink(inode, 1);
3401                 err = ext4_orphan_del(handle, inode);
3402                 if (err)
3403                         goto err_drop_inode;
3404         } else {
3405                 /* clear the extent format for fast symlink */
3406                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3407                 if (!IS_ENCRYPTED(inode)) {
3408                         inode->i_op = &ext4_fast_symlink_inode_operations;
3409                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3410                 }
3411                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3412                        disk_link.len);
3413                 inode->i_size = disk_link.len - 1;
3414         }
3415         EXT4_I(inode)->i_disksize = inode->i_size;
3416         err = ext4_add_nondir(handle, dentry, &inode);
3417         if (handle)
3418                 ext4_journal_stop(handle);
3419         if (inode)
3420                 iput(inode);
3421         goto out_free_encrypted_link;
3422
3423 err_drop_inode:
3424         if (handle)
3425                 ext4_journal_stop(handle);
3426         clear_nlink(inode);
3427         unlock_new_inode(inode);
3428         iput(inode);
3429 out_free_encrypted_link:
3430         if (disk_link.name != (unsigned char *)symname)
3431                 kfree(disk_link.name);
3432         return err;
3433 }
3434
3435 int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry)
3436 {
3437         handle_t *handle;
3438         int err, retries = 0;
3439 retry:
3440         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3441                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3442                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3443         if (IS_ERR(handle))
3444                 return PTR_ERR(handle);
3445
3446         if (IS_DIRSYNC(dir))
3447                 ext4_handle_sync(handle);
3448
3449         inode->i_ctime = current_time(inode);
3450         ext4_inc_count(inode);
3451         ihold(inode);
3452
3453         err = ext4_add_entry(handle, dentry, inode);
3454         if (!err) {
3455                 err = ext4_mark_inode_dirty(handle, inode);
3456                 /* this can happen only for tmpfile being
3457                  * linked the first time
3458                  */
3459                 if (inode->i_nlink == 1)
3460                         ext4_orphan_del(handle, inode);
3461                 d_instantiate(dentry, inode);
3462                 ext4_fc_track_link(handle, dentry);
3463         } else {
3464                 drop_nlink(inode);
3465                 iput(inode);
3466         }
3467         ext4_journal_stop(handle);
3468         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3469                 goto retry;
3470         return err;
3471 }
3472
3473 static int ext4_link(struct dentry *old_dentry,
3474                      struct inode *dir, struct dentry *dentry)
3475 {
3476         struct inode *inode = d_inode(old_dentry);
3477         int err;
3478
3479         if (inode->i_nlink >= EXT4_LINK_MAX)
3480                 return -EMLINK;
3481
3482         err = fscrypt_prepare_link(old_dentry, dir, dentry);
3483         if (err)
3484                 return err;
3485
3486         if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3487             (!projid_eq(EXT4_I(dir)->i_projid,
3488                         EXT4_I(old_dentry->d_inode)->i_projid)))
3489                 return -EXDEV;
3490
3491         err = dquot_initialize(dir);
3492         if (err)
3493                 return err;
3494         return __ext4_link(dir, inode, dentry);
3495 }
3496
3497 /*
3498  * Try to find buffer head where contains the parent block.
3499  * It should be the inode block if it is inlined or the 1st block
3500  * if it is a normal dir.
3501  */
3502 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3503                                         struct inode *inode,
3504                                         int *retval,
3505                                         struct ext4_dir_entry_2 **parent_de,
3506                                         int *inlined)
3507 {
3508         struct buffer_head *bh;
3509
3510         if (!ext4_has_inline_data(inode)) {
3511                 /* The first directory block must not be a hole, so
3512                  * treat it as DIRENT_HTREE
3513                  */
3514                 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
3515                 if (IS_ERR(bh)) {
3516                         *retval = PTR_ERR(bh);
3517                         return NULL;
3518                 }
3519                 *parent_de = ext4_next_entry(
3520                                         (struct ext4_dir_entry_2 *)bh->b_data,
3521                                         inode->i_sb->s_blocksize);
3522                 return bh;
3523         }
3524
3525         *inlined = 1;
3526         return ext4_get_first_inline_block(inode, parent_de, retval);
3527 }
3528
3529 struct ext4_renament {
3530         struct inode *dir;
3531         struct dentry *dentry;
3532         struct inode *inode;
3533         bool is_dir;
3534         int dir_nlink_delta;
3535
3536         /* entry for "dentry" */
3537         struct buffer_head *bh;
3538         struct ext4_dir_entry_2 *de;
3539         int inlined;
3540
3541         /* entry for ".." in inode if it's a directory */
3542         struct buffer_head *dir_bh;
3543         struct ext4_dir_entry_2 *parent_de;
3544         int dir_inlined;
3545 };
3546
3547 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3548 {
3549         int retval;
3550
3551         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3552                                               &retval, &ent->parent_de,
3553                                               &ent->dir_inlined);
3554         if (!ent->dir_bh)
3555                 return retval;
3556         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3557                 return -EFSCORRUPTED;
3558         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3559         return ext4_journal_get_write_access(handle, ent->dir_bh);
3560 }
3561
3562 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3563                                   unsigned dir_ino)
3564 {
3565         int retval;
3566
3567         ent->parent_de->inode = cpu_to_le32(dir_ino);
3568         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3569         if (!ent->dir_inlined) {
3570                 if (is_dx(ent->inode)) {
3571                         retval = ext4_handle_dirty_dx_node(handle,
3572                                                            ent->inode,
3573                                                            ent->dir_bh);
3574                 } else {
3575                         retval = ext4_handle_dirty_dirblock(handle, ent->inode,
3576                                                             ent->dir_bh);
3577                 }
3578         } else {
3579                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3580         }
3581         if (retval) {
3582                 ext4_std_error(ent->dir->i_sb, retval);
3583                 return retval;
3584         }
3585         return 0;
3586 }
3587
3588 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3589                        unsigned ino, unsigned file_type)
3590 {
3591         int retval, retval2;
3592
3593         BUFFER_TRACE(ent->bh, "get write access");
3594         retval = ext4_journal_get_write_access(handle, ent->bh);
3595         if (retval)
3596                 return retval;
3597         ent->de->inode = cpu_to_le32(ino);
3598         if (ext4_has_feature_filetype(ent->dir->i_sb))
3599                 ent->de->file_type = file_type;
3600         inode_inc_iversion(ent->dir);
3601         ent->dir->i_ctime = ent->dir->i_mtime =
3602                 current_time(ent->dir);
3603         retval = ext4_mark_inode_dirty(handle, ent->dir);
3604         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3605         if (!ent->inlined) {
3606                 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh);
3607                 if (unlikely(retval2)) {
3608                         ext4_std_error(ent->dir->i_sb, retval2);
3609                         return retval2;
3610                 }
3611         }
3612         return retval;
3613 }
3614
3615 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3616                                   const struct qstr *d_name)
3617 {
3618         int retval = -ENOENT;
3619         struct buffer_head *bh;
3620         struct ext4_dir_entry_2 *de;
3621
3622         bh = ext4_find_entry(dir, d_name, &de, NULL);
3623         if (IS_ERR(bh))
3624                 return PTR_ERR(bh);
3625         if (bh) {
3626                 retval = ext4_delete_entry(handle, dir, de, bh);
3627                 brelse(bh);
3628         }
3629         return retval;
3630 }
3631
3632 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3633                                int force_reread)
3634 {
3635         int retval;
3636         /*
3637          * ent->de could have moved from under us during htree split, so make
3638          * sure that we are deleting the right entry.  We might also be pointing
3639          * to a stale entry in the unused part of ent->bh so just checking inum
3640          * and the name isn't enough.
3641          */
3642         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3643             ent->de->name_len != ent->dentry->d_name.len ||
3644             strncmp(ent->de->name, ent->dentry->d_name.name,
3645                     ent->de->name_len) ||
3646             force_reread) {
3647                 retval = ext4_find_delete_entry(handle, ent->dir,
3648                                                 &ent->dentry->d_name);
3649         } else {
3650                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3651                 if (retval == -ENOENT) {
3652                         retval = ext4_find_delete_entry(handle, ent->dir,
3653                                                         &ent->dentry->d_name);
3654                 }
3655         }
3656
3657         if (retval) {
3658                 ext4_warning_inode(ent->dir,
3659                                    "Deleting old file: nlink %d, error=%d",
3660                                    ent->dir->i_nlink, retval);
3661         }
3662 }
3663
3664 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3665 {
3666         if (ent->dir_nlink_delta) {
3667                 if (ent->dir_nlink_delta == -1)
3668                         ext4_dec_count(ent->dir);
3669                 else
3670                         ext4_inc_count(ent->dir);
3671                 ext4_mark_inode_dirty(handle, ent->dir);
3672         }
3673 }
3674
3675 static struct inode *ext4_whiteout_for_rename(struct user_namespace *mnt_userns,
3676                                               struct ext4_renament *ent,
3677                                               int credits, handle_t **h)
3678 {
3679         struct inode *wh;
3680         handle_t *handle;
3681         int retries = 0;
3682
3683         /*
3684          * for inode block, sb block, group summaries,
3685          * and inode bitmap
3686          */
3687         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3688                     EXT4_XATTR_TRANS_BLOCKS + 4);
3689 retry:
3690         wh = ext4_new_inode_start_handle(mnt_userns, ent->dir,
3691                                          S_IFCHR | WHITEOUT_MODE,
3692                                          &ent->dentry->d_name, 0, NULL,
3693                                          EXT4_HT_DIR, credits);
3694
3695         handle = ext4_journal_current_handle();
3696         if (IS_ERR(wh)) {
3697                 if (handle)
3698                         ext4_journal_stop(handle);
3699                 if (PTR_ERR(wh) == -ENOSPC &&
3700                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3701                         goto retry;
3702         } else {
3703                 *h = handle;
3704                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3705                 wh->i_op = &ext4_special_inode_operations;
3706         }
3707         return wh;
3708 }
3709
3710 /*
3711  * Anybody can rename anything with this: the permission checks are left to the
3712  * higher-level routines.
3713  *
3714  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3715  * while new_{dentry,inode) refers to the destination dentry/inode
3716  * This comes from rename(const char *oldpath, const char *newpath)
3717  */
3718 static int ext4_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
3719                        struct dentry *old_dentry, struct inode *new_dir,
3720                        struct dentry *new_dentry, unsigned int flags)
3721 {
3722         handle_t *handle = NULL;
3723         struct ext4_renament old = {
3724                 .dir = old_dir,
3725                 .dentry = old_dentry,
3726                 .inode = d_inode(old_dentry),
3727         };
3728         struct ext4_renament new = {
3729                 .dir = new_dir,
3730                 .dentry = new_dentry,
3731                 .inode = d_inode(new_dentry),
3732         };
3733         int force_reread;
3734         int retval;
3735         struct inode *whiteout = NULL;
3736         int credits;
3737         u8 old_file_type;
3738
3739         if (new.inode && new.inode->i_nlink == 0) {
3740                 EXT4_ERROR_INODE(new.inode,
3741                                  "target of rename is already freed");
3742                 return -EFSCORRUPTED;
3743         }
3744
3745         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3746             (!projid_eq(EXT4_I(new_dir)->i_projid,
3747                         EXT4_I(old_dentry->d_inode)->i_projid)))
3748                 return -EXDEV;
3749
3750         retval = dquot_initialize(old.dir);
3751         if (retval)
3752                 return retval;
3753         retval = dquot_initialize(new.dir);
3754         if (retval)
3755                 return retval;
3756
3757         /* Initialize quotas before so that eventual writes go
3758          * in separate transaction */
3759         if (new.inode) {
3760                 retval = dquot_initialize(new.inode);
3761                 if (retval)
3762                         return retval;
3763         }
3764
3765         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3766         if (IS_ERR(old.bh))
3767                 return PTR_ERR(old.bh);
3768         /*
3769          *  Check for inode number is _not_ due to possible IO errors.
3770          *  We might rmdir the source, keep it as pwd of some process
3771          *  and merrily kill the link to whatever was created under the
3772          *  same name. Goodbye sticky bit ;-<
3773          */
3774         retval = -ENOENT;
3775         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3776                 goto end_rename;
3777
3778         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3779                                  &new.de, &new.inlined);
3780         if (IS_ERR(new.bh)) {
3781                 retval = PTR_ERR(new.bh);
3782                 new.bh = NULL;
3783                 goto end_rename;
3784         }
3785         if (new.bh) {
3786                 if (!new.inode) {
3787                         brelse(new.bh);
3788                         new.bh = NULL;
3789                 }
3790         }
3791         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3792                 ext4_alloc_da_blocks(old.inode);
3793
3794         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3795                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3796         if (!(flags & RENAME_WHITEOUT)) {
3797                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3798                 if (IS_ERR(handle)) {
3799                         retval = PTR_ERR(handle);
3800                         handle = NULL;
3801                         goto end_rename;
3802                 }
3803         } else {
3804                 whiteout = ext4_whiteout_for_rename(mnt_userns, &old, credits, &handle);
3805                 if (IS_ERR(whiteout)) {
3806                         retval = PTR_ERR(whiteout);
3807                         whiteout = NULL;
3808                         goto end_rename;
3809                 }
3810         }
3811
3812         old_file_type = old.de->file_type;
3813         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3814                 ext4_handle_sync(handle);
3815
3816         if (S_ISDIR(old.inode->i_mode)) {
3817                 if (new.inode) {
3818                         retval = -ENOTEMPTY;
3819                         if (!ext4_empty_dir(new.inode))
3820                                 goto end_rename;
3821                 } else {
3822                         retval = -EMLINK;
3823                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3824                                 goto end_rename;
3825                 }
3826                 retval = ext4_rename_dir_prepare(handle, &old);
3827                 if (retval)
3828                         goto end_rename;
3829         }
3830         /*
3831          * If we're renaming a file within an inline_data dir and adding or
3832          * setting the new dirent causes a conversion from inline_data to
3833          * extents/blockmap, we need to force the dirent delete code to
3834          * re-read the directory, or else we end up trying to delete a dirent
3835          * from what is now the extent tree root (or a block map).
3836          */
3837         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3838                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3839
3840         if (whiteout) {
3841                 /*
3842                  * Do this before adding a new entry, so the old entry is sure
3843                  * to be still pointing to the valid old entry.
3844                  */
3845                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3846                                      EXT4_FT_CHRDEV);
3847                 if (retval)
3848                         goto end_rename;
3849                 retval = ext4_mark_inode_dirty(handle, whiteout);
3850                 if (unlikely(retval))
3851                         goto end_rename;
3852         }
3853         if (!new.bh) {
3854                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3855                 if (retval)
3856                         goto end_rename;
3857         } else {
3858                 retval = ext4_setent(handle, &new,
3859                                      old.inode->i_ino, old_file_type);
3860                 if (retval)
3861                         goto end_rename;
3862         }
3863         if (force_reread)
3864                 force_reread = !ext4_test_inode_flag(new.dir,
3865                                                      EXT4_INODE_INLINE_DATA);
3866
3867         /*
3868          * Like most other Unix systems, set the ctime for inodes on a
3869          * rename.
3870          */
3871         old.inode->i_ctime = current_time(old.inode);
3872         retval = ext4_mark_inode_dirty(handle, old.inode);
3873         if (unlikely(retval))
3874                 goto end_rename;
3875
3876         if (!whiteout) {
3877                 /*
3878                  * ok, that's it
3879                  */
3880                 ext4_rename_delete(handle, &old, force_reread);
3881         }
3882
3883         if (new.inode) {
3884                 ext4_dec_count(new.inode);
3885                 new.inode->i_ctime = current_time(new.inode);
3886         }
3887         old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
3888         ext4_update_dx_flag(old.dir);
3889         if (old.dir_bh) {
3890                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3891                 if (retval)
3892                         goto end_rename;
3893
3894                 ext4_dec_count(old.dir);
3895                 if (new.inode) {
3896                         /* checked ext4_empty_dir above, can't have another
3897                          * parent, ext4_dec_count() won't work for many-linked
3898                          * dirs */
3899                         clear_nlink(new.inode);
3900                 } else {
3901                         ext4_inc_count(new.dir);
3902                         ext4_update_dx_flag(new.dir);
3903                         retval = ext4_mark_inode_dirty(handle, new.dir);
3904                         if (unlikely(retval))
3905                                 goto end_rename;
3906                 }
3907         }
3908         retval = ext4_mark_inode_dirty(handle, old.dir);
3909         if (unlikely(retval))
3910                 goto end_rename;
3911
3912         if (S_ISDIR(old.inode->i_mode)) {
3913                 /*
3914                  * We disable fast commits here that's because the
3915                  * replay code is not yet capable of changing dot dot
3916                  * dirents in directories.
3917                  */
3918                 ext4_fc_mark_ineligible(old.inode->i_sb,
3919                         EXT4_FC_REASON_RENAME_DIR);
3920         } else {
3921                 if (new.inode)
3922                         ext4_fc_track_unlink(handle, new.dentry);
3923                 __ext4_fc_track_link(handle, old.inode, new.dentry);
3924                 __ext4_fc_track_unlink(handle, old.inode, old.dentry);
3925         }
3926
3927         if (new.inode) {
3928                 retval = ext4_mark_inode_dirty(handle, new.inode);
3929                 if (unlikely(retval))
3930                         goto end_rename;
3931                 if (!new.inode->i_nlink)
3932                         ext4_orphan_add(handle, new.inode);
3933         }
3934         retval = 0;
3935
3936 end_rename:
3937         if (whiteout) {
3938                 if (retval) {
3939                         ext4_setent(handle, &old,
3940                                 old.inode->i_ino, old_file_type);
3941                         drop_nlink(whiteout);
3942                 }
3943                 unlock_new_inode(whiteout);
3944                 iput(whiteout);
3945
3946         }
3947         brelse(old.dir_bh);
3948         brelse(old.bh);
3949         brelse(new.bh);
3950         if (handle)
3951                 ext4_journal_stop(handle);
3952         return retval;
3953 }
3954
3955 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3956                              struct inode *new_dir, struct dentry *new_dentry)
3957 {
3958         handle_t *handle = NULL;
3959         struct ext4_renament old = {
3960                 .dir = old_dir,
3961                 .dentry = old_dentry,
3962                 .inode = d_inode(old_dentry),
3963         };
3964         struct ext4_renament new = {
3965                 .dir = new_dir,
3966                 .dentry = new_dentry,
3967                 .inode = d_inode(new_dentry),
3968         };
3969         u8 new_file_type;
3970         int retval;
3971         struct timespec64 ctime;
3972
3973         if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3974              !projid_eq(EXT4_I(new_dir)->i_projid,
3975                         EXT4_I(old_dentry->d_inode)->i_projid)) ||
3976             (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3977              !projid_eq(EXT4_I(old_dir)->i_projid,
3978                         EXT4_I(new_dentry->d_inode)->i_projid)))
3979                 return -EXDEV;
3980
3981         retval = dquot_initialize(old.dir);
3982         if (retval)
3983                 return retval;
3984         retval = dquot_initialize(new.dir);
3985         if (retval)
3986                 return retval;
3987
3988         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3989                                  &old.de, &old.inlined);
3990         if (IS_ERR(old.bh))
3991                 return PTR_ERR(old.bh);
3992         /*
3993          *  Check for inode number is _not_ due to possible IO errors.
3994          *  We might rmdir the source, keep it as pwd of some process
3995          *  and merrily kill the link to whatever was created under the
3996          *  same name. Goodbye sticky bit ;-<
3997          */
3998         retval = -ENOENT;
3999         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
4000                 goto end_rename;
4001
4002         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
4003                                  &new.de, &new.inlined);
4004         if (IS_ERR(new.bh)) {
4005                 retval = PTR_ERR(new.bh);
4006                 new.bh = NULL;
4007                 goto end_rename;
4008         }
4009
4010         /* RENAME_EXCHANGE case: old *and* new must both exist */
4011         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
4012                 goto end_rename;
4013
4014         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
4015                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
4016                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
4017         if (IS_ERR(handle)) {
4018                 retval = PTR_ERR(handle);
4019                 handle = NULL;
4020                 goto end_rename;
4021         }
4022
4023         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
4024                 ext4_handle_sync(handle);
4025
4026         if (S_ISDIR(old.inode->i_mode)) {
4027                 old.is_dir = true;
4028                 retval = ext4_rename_dir_prepare(handle, &old);
4029                 if (retval)
4030                         goto end_rename;
4031         }
4032         if (S_ISDIR(new.inode->i_mode)) {
4033                 new.is_dir = true;
4034                 retval = ext4_rename_dir_prepare(handle, &new);
4035                 if (retval)
4036                         goto end_rename;
4037         }
4038
4039         /*
4040          * Other than the special case of overwriting a directory, parents'
4041          * nlink only needs to be modified if this is a cross directory rename.
4042          */
4043         if (old.dir != new.dir && old.is_dir != new.is_dir) {
4044                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
4045                 new.dir_nlink_delta = -old.dir_nlink_delta;
4046                 retval = -EMLINK;
4047                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
4048                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
4049                         goto end_rename;
4050         }
4051
4052         new_file_type = new.de->file_type;
4053         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
4054         if (retval)
4055                 goto end_rename;
4056
4057         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
4058         if (retval)
4059                 goto end_rename;
4060
4061         /*
4062          * Like most other Unix systems, set the ctime for inodes on a
4063          * rename.
4064          */
4065         ctime = current_time(old.inode);
4066         old.inode->i_ctime = ctime;
4067         new.inode->i_ctime = ctime;
4068         retval = ext4_mark_inode_dirty(handle, old.inode);
4069         if (unlikely(retval))
4070                 goto end_rename;
4071         retval = ext4_mark_inode_dirty(handle, new.inode);
4072         if (unlikely(retval))
4073                 goto end_rename;
4074         ext4_fc_mark_ineligible(new.inode->i_sb,
4075                                 EXT4_FC_REASON_CROSS_RENAME);
4076         if (old.dir_bh) {
4077                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
4078                 if (retval)
4079                         goto end_rename;
4080         }
4081         if (new.dir_bh) {
4082                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
4083                 if (retval)
4084                         goto end_rename;
4085         }
4086         ext4_update_dir_count(handle, &old);
4087         ext4_update_dir_count(handle, &new);
4088         retval = 0;
4089
4090 end_rename:
4091         brelse(old.dir_bh);
4092         brelse(new.dir_bh);
4093         brelse(old.bh);
4094         brelse(new.bh);
4095         if (handle)
4096                 ext4_journal_stop(handle);
4097         return retval;
4098 }
4099
4100 static int ext4_rename2(struct user_namespace *mnt_userns,
4101                         struct inode *old_dir, struct dentry *old_dentry,
4102                         struct inode *new_dir, struct dentry *new_dentry,
4103                         unsigned int flags)
4104 {
4105         int err;
4106
4107         if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
4108                 return -EIO;
4109
4110         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
4111                 return -EINVAL;
4112
4113         err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
4114                                      flags);
4115         if (err)
4116                 return err;
4117
4118         if (flags & RENAME_EXCHANGE) {
4119                 return ext4_cross_rename(old_dir, old_dentry,
4120                                          new_dir, new_dentry);
4121         }
4122
4123         return ext4_rename(mnt_userns, old_dir, old_dentry, new_dir, new_dentry, flags);
4124 }
4125
4126 /*
4127  * directories can handle most operations...
4128  */
4129 const struct inode_operations ext4_dir_inode_operations = {
4130         .create         = ext4_create,
4131         .lookup         = ext4_lookup,
4132         .link           = ext4_link,
4133         .unlink         = ext4_unlink,
4134         .symlink        = ext4_symlink,
4135         .mkdir          = ext4_mkdir,
4136         .rmdir          = ext4_rmdir,
4137         .mknod          = ext4_mknod,
4138         .tmpfile        = ext4_tmpfile,
4139         .rename         = ext4_rename2,
4140         .setattr        = ext4_setattr,
4141         .getattr        = ext4_getattr,
4142         .listxattr      = ext4_listxattr,
4143         .get_acl        = ext4_get_acl,
4144         .set_acl        = ext4_set_acl,
4145         .fiemap         = ext4_fiemap,
4146 };
4147
4148 const struct inode_operations ext4_special_inode_operations = {
4149         .setattr        = ext4_setattr,
4150         .getattr        = ext4_getattr,
4151         .listxattr      = ext4_listxattr,
4152         .get_acl        = ext4_get_acl,
4153         .set_acl        = ext4_set_acl,
4154 };