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