fs/ext4/namei.c

   1 /*
   2  *  linux/fs/ext4/namei.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/namei.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  *  Directory entry file type support and forward compatibility hooks
  18  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  19  *  Hash Tree Directory indexing (c)
  20  *      Daniel Phillips, 2001
  21  *  Hash Tree Directory indexing porting
  22  *      Christopher Li, 2002
  23  *  Hash Tree Directory indexing cleanup
  24  *      Theodore Ts'o, 2002
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/time.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/stat.h>
  32 #include <linux/string.h>
  33 #include <linux/quotaops.h>
  34 #include <linux/buffer_head.h>
  35 #include <linux/bio.h>
  36 #include "ext4.h"
  37 #include "ext4_jbd2.h"
  38
  39 #include "xattr.h"
  40 #include "acl.h"
  41
  42 #include <trace/events/ext4.h>
  43 /*
  44  * define how far ahead to read directories while searching them.
  45  */
  46 #define NAMEI_RA_CHUNKS  2
  47 #define NAMEI_RA_BLOCKS  4
  48 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  49
  50 static struct buffer_head *ext4_append(handle_t *handle,
  51                                         struct inode *inode,
  52                                         ext4_lblk_t *block)
  53 {
  54         struct buffer_head *bh;
  55         int err;
  56
  57         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  58                      ((inode->i_size >> 10) >=
  59                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
  60                 return ERR_PTR(-ENOSPC);
  61
  62         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  63
  64         bh = ext4_bread(handle, inode, *block, 1);
  65         if (IS_ERR(bh))
  66                 return bh;
  67         inode->i_size += inode->i_sb->s_blocksize;
  68         EXT4_I(inode)->i_disksize = inode->i_size;
  69         BUFFER_TRACE(bh, "get_write_access");
  70         err = ext4_journal_get_write_access(handle, bh);
  71         if (err) {
  72                 brelse(bh);
  73                 ext4_std_error(inode->i_sb, err);
  74                 return ERR_PTR(err);
  75         }
  76         return bh;
  77 }
  78
  79 static int ext4_dx_csum_verify(struct inode *inode,
  80                                struct ext4_dir_entry *dirent);
  81
  82 typedef enum {
  83         EITHER, INDEX, DIRENT
  84 } dirblock_type_t;
  85
  86 #define ext4_read_dirblock(inode, block, type) \
  87         __ext4_read_dirblock((inode), (block), (type), __LINE__)
  88
  89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
  90                                               ext4_lblk_t block,
  91                                               dirblock_type_t type,
  92                                               unsigned int line)
  93 {
  94         struct buffer_head *bh;
  95         struct ext4_dir_entry *dirent;
  96         int is_dx_block = 0;
  97
  98         bh = ext4_bread(NULL, inode, block, 0);
  99         if (IS_ERR(bh)) {
 100                 __ext4_warning(inode->i_sb, __func__, line,
 101                                "error %ld reading directory block "
 102                                "(ino %lu, block %lu)", PTR_ERR(bh), inode->i_ino,
 103                                (unsigned long) block);
 104
 105                 return bh;
 106         }
 107         if (!bh) {
 108                 ext4_error_inode(inode, __func__, line, block, "Directory hole found");
 109                 return ERR_PTR(-EIO);
 110         }
 111         dirent = (struct ext4_dir_entry *) bh->b_data;
 112         /* Determine whether or not we have an index block */
 113         if (is_dx(inode)) {
 114                 if (block == 0)
 115                         is_dx_block = 1;
 116                 else if (ext4_rec_len_from_disk(dirent->rec_len,
 117                                                 inode->i_sb->s_blocksize) ==
 118                          inode->i_sb->s_blocksize)
 119                         is_dx_block = 1;
 120         }
 121         if (!is_dx_block && type == INDEX) {
 122                 ext4_error_inode(inode, __func__, line, block,
 123                        "directory leaf block found instead of index block");
 124                 return ERR_PTR(-EIO);
 125         }
 126         if (!ext4_has_metadata_csum(inode->i_sb) ||
 127             buffer_verified(bh))
 128                 return bh;
 129
 130         /*
 131          * An empty leaf block can get mistaken for a index block; for
 132          * this reason, we can only check the index checksum when the
 133          * caller is sure it should be an index block.
 134          */
 135         if (is_dx_block && type == INDEX) {
 136                 if (ext4_dx_csum_verify(inode, dirent))
 137                         set_buffer_verified(bh);
 138                 else {
 139                         ext4_error_inode(inode, __func__, line, block,
 140                                 "Directory index failed checksum");
 141                         brelse(bh);
 142                         return ERR_PTR(-EIO);
 143                 }
 144         }
 145         if (!is_dx_block) {
 146                 if (ext4_dirent_csum_verify(inode, dirent))
 147                         set_buffer_verified(bh);
 148                 else {
 149                         ext4_error_inode(inode, __func__, line, block,
 150                                 "Directory block failed checksum");
 151                         brelse(bh);
 152                         return ERR_PTR(-EIO);
 153                 }
 154         }
 155         return bh;
 156 }
 157
 158 #ifndef assert
 159 #define assert(test) J_ASSERT(test)
 160 #endif
 161
 162 #ifdef DX_DEBUG
 163 #define dxtrace(command) command
 164 #else
 165 #define dxtrace(command)
 166 #endif
 167
 168 struct fake_dirent
 169 {
 170         __le32 inode;
 171         __le16 rec_len;
 172         u8 name_len;
 173         u8 file_type;
 174 };
 175
 176 struct dx_countlimit
 177 {
 178         __le16 limit;
 179         __le16 count;
 180 };
 181
 182 struct dx_entry
 183 {
 184         __le32 hash;
 185         __le32 block;
 186 };
 187
 188 /*
 189  * dx_root_info is laid out so that if it should somehow get overlaid by a
 190  * dirent the two low bits of the hash version will be zero.  Therefore, the
 191  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 192  */
 193
 194 struct dx_root
 195 {
 196         struct fake_dirent dot;
 197         char dot_name[4];
 198         struct fake_dirent dotdot;
 199         char dotdot_name[4];
 200         struct dx_root_info
 201         {
 202                 __le32 reserved_zero;
 203                 u8 hash_version;
 204                 u8 info_length; /* 8 */
 205                 u8 indirect_levels;
 206                 u8 unused_flags;
 207         }
 208         info;
 209         struct dx_entry entries[0];
 210 };
 211
 212 struct dx_node
 213 {
 214         struct fake_dirent fake;
 215         struct dx_entry entries[0];
 216 };
 217
 218
 219 struct dx_frame
 220 {
 221         struct buffer_head *bh;
 222         struct dx_entry *entries;
 223         struct dx_entry *at;
 224 };
 225
 226 struct dx_map_entry
 227 {
 228         u32 hash;
 229         u16 offs;
 230         u16 size;
 231 };
 232
 233 /*
 234  * This goes at the end of each htree block.
 235  */
 236 struct dx_tail {
 237         u32 dt_reserved;
 238         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 239 };
 240
 241 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 242 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 243 static inline unsigned dx_get_hash(struct dx_entry *entry);
 244 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 245 static unsigned dx_get_count(struct dx_entry *entries);
 246 static unsigned dx_get_limit(struct dx_entry *entries);
 247 static void dx_set_count(struct dx_entry *entries, unsigned value);
 248 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 249 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 250 static unsigned dx_node_limit(struct inode *dir);
 251 static struct dx_frame *dx_probe(const struct qstr *d_name,
 252                                  struct inode *dir,
 253                                  struct dx_hash_info *hinfo,
 254                                  struct dx_frame *frame);
 255 static void dx_release(struct dx_frame *frames);
 256 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 257                        unsigned blocksize, struct dx_hash_info *hinfo,
 258                        struct dx_map_entry map[]);
 259 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 260 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 261                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 262 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 263 static void dx_insert_block(struct dx_frame *frame,
 264                                         u32 hash, ext4_lblk_t block);
 265 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 266                                  struct dx_frame *frame,
 267                                  struct dx_frame *frames,
 268                                  __u32 *start_hash);
 269 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 270                 const struct qstr *d_name,
 271                 struct ext4_dir_entry_2 **res_dir);
 272 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 273                              struct inode *inode);
 274
 275 /* checksumming functions */
 276 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 277                             unsigned int blocksize)
 278 {
 279         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 280         t->det_rec_len = ext4_rec_len_to_disk(
 281                         sizeof(struct ext4_dir_entry_tail), blocksize);
 282         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 283 }
 284
 285 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 286 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 287                                                    struct ext4_dir_entry *de)
 288 {
 289         struct ext4_dir_entry_tail *t;
 290
 291 #ifdef PARANOID
 292         struct ext4_dir_entry *d, *top;
 293
 294         d = de;
 295         top = (struct ext4_dir_entry *)(((void *)de) +
 296                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 297                 sizeof(struct ext4_dir_entry_tail)));
 298         while (d < top && d->rec_len)
 299                 d = (struct ext4_dir_entry *)(((void *)d) +
 300                     le16_to_cpu(d->rec_len));
 301
 302         if (d != top)
 303                 return NULL;
 304
 305         t = (struct ext4_dir_entry_tail *)d;
 306 #else
 307         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 308 #endif
 309
 310         if (t->det_reserved_zero1 ||
 311             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 312             t->det_reserved_zero2 ||
 313             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 314                 return NULL;
 315
 316         return t;
 317 }
 318
 319 static __le32 ext4_dirent_csum(struct inode *inode,
 320                                struct ext4_dir_entry *dirent, int size)
 321 {
 322         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 323         struct ext4_inode_info *ei = EXT4_I(inode);
 324         __u32 csum;
 325
 326         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 327         return cpu_to_le32(csum);
 328 }
 329
 330 static void warn_no_space_for_csum(struct inode *inode)
 331 {
 332         ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for "
 333                      "checksum.  Please run e2fsck -D.", inode->i_ino);
 334 }
 335
 336 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 337 {
 338         struct ext4_dir_entry_tail *t;
 339
 340         if (!ext4_has_metadata_csum(inode->i_sb))
 341                 return 1;
 342
 343         t = get_dirent_tail(inode, dirent);
 344         if (!t) {
 345                 warn_no_space_for_csum(inode);
 346                 return 0;
 347         }
 348
 349         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 350                                                 (void *)t - (void *)dirent))
 351                 return 0;
 352
 353         return 1;
 354 }
 355
 356 static void ext4_dirent_csum_set(struct inode *inode,
 357                                  struct ext4_dir_entry *dirent)
 358 {
 359         struct ext4_dir_entry_tail *t;
 360
 361         if (!ext4_has_metadata_csum(inode->i_sb))
 362                 return;
 363
 364         t = get_dirent_tail(inode, dirent);
 365         if (!t) {
 366                 warn_no_space_for_csum(inode);
 367                 return;
 368         }
 369
 370         t->det_checksum = ext4_dirent_csum(inode, dirent,
 371                                            (void *)t - (void *)dirent);
 372 }
 373
 374 int ext4_handle_dirty_dirent_node(handle_t *handle,
 375                                   struct inode *inode,
 376                                   struct buffer_head *bh)
 377 {
 378         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 379         return ext4_handle_dirty_metadata(handle, inode, bh);
 380 }
 381
 382 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 383                                                struct ext4_dir_entry *dirent,
 384                                                int *offset)
 385 {
 386         struct ext4_dir_entry *dp;
 387         struct dx_root_info *root;
 388         int count_offset;
 389
 390         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 391                 count_offset = 8;
 392         else if (le16_to_cpu(dirent->rec_len) == 12) {
 393                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 394                 if (le16_to_cpu(dp->rec_len) !=
 395                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 396                         return NULL;
 397                 root = (struct dx_root_info *)(((void *)dp + 12));
 398                 if (root->reserved_zero ||
 399                     root->info_length != sizeof(struct dx_root_info))
 400                         return NULL;
 401                 count_offset = 32;
 402         } else
 403                 return NULL;
 404
 405         if (offset)
 406                 *offset = count_offset;
 407         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 408 }
 409
 410 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 411                            int count_offset, int count, struct dx_tail *t)
 412 {
 413         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 414         struct ext4_inode_info *ei = EXT4_I(inode);
 415         __u32 csum;
 416         __le32 save_csum;
 417         int size;
 418
 419         size = count_offset + (count * sizeof(struct dx_entry));
 420         save_csum = t->dt_checksum;
 421         t->dt_checksum = 0;
 422         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 423         csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
 424         t->dt_checksum = save_csum;
 425
 426         return cpu_to_le32(csum);
 427 }
 428
 429 static int ext4_dx_csum_verify(struct inode *inode,
 430                                struct ext4_dir_entry *dirent)
 431 {
 432         struct dx_countlimit *c;
 433         struct dx_tail *t;
 434         int count_offset, limit, count;
 435
 436         if (!ext4_has_metadata_csum(inode->i_sb))
 437                 return 1;
 438
 439         c = get_dx_countlimit(inode, dirent, &count_offset);
 440         if (!c) {
 441                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 442                 return 1;
 443         }
 444         limit = le16_to_cpu(c->limit);
 445         count = le16_to_cpu(c->count);
 446         if (count_offset + (limit * sizeof(struct dx_entry)) >
 447             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 448                 warn_no_space_for_csum(inode);
 449                 return 1;
 450         }
 451         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 452
 453         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 454                                             count, t))
 455                 return 0;
 456         return 1;
 457 }
 458
 459 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 460 {
 461         struct dx_countlimit *c;
 462         struct dx_tail *t;
 463         int count_offset, limit, count;
 464
 465         if (!ext4_has_metadata_csum(inode->i_sb))
 466                 return;
 467
 468         c = get_dx_countlimit(inode, dirent, &count_offset);
 469         if (!c) {
 470                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 471                 return;
 472         }
 473         limit = le16_to_cpu(c->limit);
 474         count = le16_to_cpu(c->count);
 475         if (count_offset + (limit * sizeof(struct dx_entry)) >
 476             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 477                 warn_no_space_for_csum(inode);
 478                 return;
 479         }
 480         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 481
 482         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 483 }
 484
 485 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 486                                             struct inode *inode,
 487                                             struct buffer_head *bh)
 488 {
 489         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 490         return ext4_handle_dirty_metadata(handle, inode, bh);
 491 }
 492
 493 /*
 494  * p is at least 6 bytes before the end of page
 495  */
 496 static inline struct ext4_dir_entry_2 *
 497 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 498 {
 499         return (struct ext4_dir_entry_2 *)((char *)p +
 500                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 501 }
 502
 503 /*
 504  * Future: use high four bits of block for coalesce-on-delete flags
 505  * Mask them off for now.
 506  */
 507
 508 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 509 {
 510         return le32_to_cpu(entry->block) & 0x00ffffff;
 511 }
 512
 513 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 514 {
 515         entry->block = cpu_to_le32(value);
 516 }
 517
 518 static inline unsigned dx_get_hash(struct dx_entry *entry)
 519 {
 520         return le32_to_cpu(entry->hash);
 521 }
 522
 523 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 524 {
 525         entry->hash = cpu_to_le32(value);
 526 }
 527
 528 static inline unsigned dx_get_count(struct dx_entry *entries)
 529 {
 530         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 531 }
 532
 533 static inline unsigned dx_get_limit(struct dx_entry *entries)
 534 {
 535         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 536 }
 537
 538 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 539 {
 540         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 541 }
 542
 543 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 544 {
 545         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 546 }
 547
 548 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 549 {
 550         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 551                 EXT4_DIR_REC_LEN(2) - infosize;
 552
 553         if (ext4_has_metadata_csum(dir->i_sb))
 554                 entry_space -= sizeof(struct dx_tail);
 555         return entry_space / sizeof(struct dx_entry);
 556 }
 557
 558 static inline unsigned dx_node_limit(struct inode *dir)
 559 {
 560         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 561
 562         if (ext4_has_metadata_csum(dir->i_sb))
 563                 entry_space -= sizeof(struct dx_tail);
 564         return entry_space / sizeof(struct dx_entry);
 565 }
 566
 567 /*
 568  * Debug
 569  */
 570 #ifdef DX_DEBUG
 571 static void dx_show_index(char * label, struct dx_entry *entries)
 572 {
 573         int i, n = dx_get_count (entries);
 574         printk(KERN_DEBUG "%s index ", label);
 575         for (i = 0; i < n; i++) {
 576                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 577                                 0, (unsigned long)dx_get_block(entries + i));
 578         }
 579         printk("\n");
 580 }
 581
 582 struct stats
 583 {
 584         unsigned names;
 585         unsigned space;
 586         unsigned bcount;
 587 };
 588
 589 static struct stats dx_show_leaf(struct inode *dir,
 590                                 struct dx_hash_info *hinfo,
 591                                 struct ext4_dir_entry_2 *de,
 592                                 int size, int show_names)
 593 {
 594         unsigned names = 0, space = 0;
 595         char *base = (char *) de;
 596         struct dx_hash_info h = *hinfo;
 597
 598         printk("names: ");
 599         while ((char *) de < base + size)
 600         {
 601                 if (de->inode)
 602                 {
 603                         if (show_names)
 604                         {
 605 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 606                                 int len;
 607                                 char *name;
 608                                 struct ext4_str fname_crypto_str
 609                                         = {.name = NULL, .len = 0};
 610                                 struct ext4_fname_crypto_ctx *ctx = NULL;
 611                                 int res;
 612
 613                                 name  = de->name;
 614                                 len = de->name_len;
 615                                 ctx = ext4_get_fname_crypto_ctx(dir,
 616                                                                 EXT4_NAME_LEN);
 617                                 if (IS_ERR(ctx)) {
 618                                         printk(KERN_WARNING "Error acquiring"
 619                                         " crypto ctxt--skipping crypto\n");
 620                                         ctx = NULL;
 621                                 }
 622                                 if (ctx == NULL) {
 623                                         /* Directory is not encrypted */
 624                                         ext4fs_dirhash(de->name,
 625                                                 de->name_len, &h);
 626                                         printk("%*.s:(U)%x.%u ", len,
 627                                                name, h.hash,
 628                                                (unsigned) ((char *) de
 629                                                            - base));
 630                                 } else {
 631                                         /* Directory is encrypted */
 632                                         res = ext4_fname_crypto_alloc_buffer(
 633                                                 ctx, de->name_len,
 634                                                 &fname_crypto_str);
 635                                         if (res < 0) {
 636                                                 printk(KERN_WARNING "Error "
 637                                                         "allocating crypto "
 638                                                         "buffer--skipping "
 639                                                         "crypto\n");
 640                                                 ext4_put_fname_crypto_ctx(&ctx);
 641                                                 ctx = NULL;
 642                                         }
 643                                         res = ext4_fname_disk_to_usr(ctx, de,
 644                                                         &fname_crypto_str);
 645                                         if (res < 0) {
 646                                                 printk(KERN_WARNING "Error "
 647                                                         "converting filename "
 648                                                         "from disk to usr"
 649                                                         "\n");
 650                                                 name = "??";
 651                                                 len = 2;
 652                                         } else {
 653                                                 name = fname_crypto_str.name;
 654                                                 len = fname_crypto_str.len;
 655                                         }
 656                                         res = ext4_fname_disk_to_hash(ctx, de,
 657                                                                       &h);
 658                                         if (res < 0) {
 659                                                 printk(KERN_WARNING "Error "
 660                                                         "converting filename "
 661                                                         "from disk to htree"
 662                                                         "\n");
 663                                                 h.hash = 0xDEADBEEF;
 664                                         }
 665                                         printk("%*.s:(E)%x.%u ", len, name,
 666                                                h.hash, (unsigned) ((char *) de
 667                                                                    - base));
 668                                         ext4_put_fname_crypto_ctx(&ctx);
 669                                         ext4_fname_crypto_free_buffer(
 670                                                 &fname_crypto_str);
 671                                 }
 672 #else
 673                                 int len = de->name_len;
 674                                 char *name = de->name;
 675                                 ext4fs_dirhash(de->name, de->name_len, &h);
 676                                 printk("%*.s:%x.%u ", len, name, h.hash,
 677                                        (unsigned) ((char *) de - base));
 678 #endif
 679                         }
 680                         space += EXT4_DIR_REC_LEN(de->name_len);
 681                         names++;
 682                 }
 683                 de = ext4_next_entry(de, size);
 684         }
 685         printk("(%i)\n", names);
 686         return (struct stats) { names, space, 1 };
 687 }
 688
 689 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 690                              struct dx_entry *entries, int levels)
 691 {
 692         unsigned blocksize = dir->i_sb->s_blocksize;
 693         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 694         unsigned bcount = 0;
 695         struct buffer_head *bh;
 696         printk("%i indexed blocks...\n", count);
 697         for (i = 0; i < count; i++, entries++)
 698         {
 699                 ext4_lblk_t block = dx_get_block(entries);
 700                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 701                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 702                 struct stats stats;
 703                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 704                 bh = ext4_bread(NULL,dir, block, 0);
 705                 if (!bh || IS_ERR(bh))
 706                         continue;
 707                 stats = levels?
 708                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 709                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 710                         bh->b_data, blocksize, 0);
 711                 names += stats.names;
 712                 space += stats.space;
 713                 bcount += stats.bcount;
 714                 brelse(bh);
 715         }
 716         if (bcount)
 717                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 718                        levels ? "" : "   ", names, space/bcount,
 719                        (space/bcount)*100/blocksize);
 720         return (struct stats) { names, space, bcount};
 721 }
 722 #endif /* DX_DEBUG */
 723
 724 /*
 725  * Probe for a directory leaf block to search.
 726  *
 727  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 728  * error in the directory index, and the caller should fall back to
 729  * searching the directory normally.  The callers of dx_probe **MUST**
 730  * check for this error code, and make sure it never gets reflected
 731  * back to userspace.
 732  */
 733 static struct dx_frame *
 734 dx_probe(const struct qstr *d_name, struct inode *dir,
 735          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 736 {
 737         unsigned count, indirect;
 738         struct dx_entry *at, *entries, *p, *q, *m;
 739         struct dx_root *root;
 740         struct dx_frame *frame = frame_in;
 741         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 742         u32 hash;
 743
 744         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 745         if (IS_ERR(frame->bh))
 746                 return (struct dx_frame *) frame->bh;
 747
 748         root = (struct dx_root *) frame->bh->b_data;
 749         if (root->info.hash_version != DX_HASH_TEA &&
 750             root->info.hash_version != DX_HASH_HALF_MD4 &&
 751             root->info.hash_version != DX_HASH_LEGACY) {
 752                 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
 753                              root->info.hash_version);
 754                 goto fail;
 755         }
 756         hinfo->hash_version = root->info.hash_version;
 757         if (hinfo->hash_version <= DX_HASH_TEA)
 758                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 759         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 760 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 761         if (d_name) {
 762                 struct ext4_fname_crypto_ctx *ctx = NULL;
 763                 int res;
 764
 765                 /* Check if the directory is encrypted */
 766                 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
 767                 if (IS_ERR(ctx)) {
 768                         ret_err = ERR_PTR(PTR_ERR(ctx));
 769                         goto fail;
 770                 }
 771                 res = ext4_fname_usr_to_hash(ctx, d_name, hinfo);
 772                 if (res < 0) {
 773                         ret_err = ERR_PTR(res);
 774                         goto fail;
 775                 }
 776                 ext4_put_fname_crypto_ctx(&ctx);
 777         }
 778 #else
 779         if (d_name)
 780                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 781 #endif
 782         hash = hinfo->hash;
 783
 784         if (root->info.unused_flags & 1) {
 785                 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
 786                              root->info.unused_flags);
 787                 goto fail;
 788         }
 789
 790         if ((indirect = root->info.indirect_levels) > 1) {
 791                 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 792                              root->info.indirect_levels);
 793                 goto fail;
 794         }
 795
 796         entries = (struct dx_entry *) (((char *)&root->info) +
 797                                        root->info.info_length);
 798
 799         if (dx_get_limit(entries) != dx_root_limit(dir,
 800                                                    root->info.info_length)) {
 801                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 802                 goto fail;
 803         }
 804
 805         dxtrace(printk("Look up %x", hash));
 806         while (1) {
 807                 count = dx_get_count(entries);
 808                 if (!count || count > dx_get_limit(entries)) {
 809                         ext4_warning(dir->i_sb,
 810                                      "dx entry: no count or count > limit");
 811                         goto fail;
 812                 }
 813
 814                 p = entries + 1;
 815                 q = entries + count - 1;
 816                 while (p <= q) {
 817                         m = p + (q - p)/2;
 818                         dxtrace(printk("."));
 819                         if (dx_get_hash(m) > hash)
 820                                 q = m - 1;
 821                         else
 822                                 p = m + 1;
 823                 }
 824
 825                 if (0) { // linear search cross check
 826                         unsigned n = count - 1;
 827                         at = entries;
 828                         while (n--)
 829                         {
 830                                 dxtrace(printk(","));
 831                                 if (dx_get_hash(++at) > hash)
 832                                 {
 833                                         at--;
 834                                         break;
 835                                 }
 836                         }
 837                         assert (at == p - 1);
 838                 }
 839
 840                 at = p - 1;
 841                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 842                 frame->entries = entries;
 843                 frame->at = at;
 844                 if (!indirect--)
 845                         return frame;
 846                 frame++;
 847                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 848                 if (IS_ERR(frame->bh)) {
 849                         ret_err = (struct dx_frame *) frame->bh;
 850                         frame->bh = NULL;
 851                         goto fail;
 852                 }
 853                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 854
 855                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 856                         ext4_warning(dir->i_sb,
 857                                      "dx entry: limit != node limit");
 858                         goto fail;
 859                 }
 860         }
 861 fail:
 862         while (frame >= frame_in) {
 863                 brelse(frame->bh);
 864                 frame--;
 865         }
 866
 867         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 868                 ext4_warning(dir->i_sb,
 869                              "Corrupt dir inode %lu, running e2fsck is "
 870                              "recommended.", dir->i_ino);
 871         return ret_err;
 872 }
 873
 874 static void dx_release (struct dx_frame *frames)
 875 {
 876         if (frames[0].bh == NULL)
 877                 return;
 878
 879         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 880                 brelse(frames[1].bh);
 881         brelse(frames[0].bh);
 882 }
 883
 884 /*
 885  * This function increments the frame pointer to search the next leaf
 886  * block, and reads in the necessary intervening nodes if the search
 887  * should be necessary.  Whether or not the search is necessary is
 888  * controlled by the hash parameter.  If the hash value is even, then
 889  * the search is only continued if the next block starts with that
 890  * hash value.  This is used if we are searching for a specific file.
 891  *
 892  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 893  *
 894  * This function returns 1 if the caller should continue to search,
 895  * or 0 if it should not.  If there is an error reading one of the
 896  * index blocks, it will a negative error code.
 897  *
 898  * If start_hash is non-null, it will be filled in with the starting
 899  * hash of the next page.
 900  */
 901 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 902                                  struct dx_frame *frame,
 903                                  struct dx_frame *frames,
 904                                  __u32 *start_hash)
 905 {
 906         struct dx_frame *p;
 907         struct buffer_head *bh;
 908         int num_frames = 0;
 909         __u32 bhash;
 910
 911         p = frame;
 912         /*
 913          * Find the next leaf page by incrementing the frame pointer.
 914          * If we run out of entries in the interior node, loop around and
 915          * increment pointer in the parent node.  When we break out of
 916          * this loop, num_frames indicates the number of interior
 917          * nodes need to be read.
 918          */
 919         while (1) {
 920                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 921                         break;
 922                 if (p == frames)
 923                         return 0;
 924                 num_frames++;
 925                 p--;
 926         }
 927
 928         /*
 929          * If the hash is 1, then continue only if the next page has a
 930          * continuation hash of any value.  This is used for readdir
 931          * handling.  Otherwise, check to see if the hash matches the
 932          * desired contiuation hash.  If it doesn't, return since
 933          * there's no point to read in the successive index pages.
 934          */
 935         bhash = dx_get_hash(p->at);
 936         if (start_hash)
 937                 *start_hash = bhash;
 938         if ((hash & 1) == 0) {
 939                 if ((bhash & ~1) != hash)
 940                         return 0;
 941         }
 942         /*
 943          * If the hash is HASH_NB_ALWAYS, we always go to the next
 944          * block so no check is necessary
 945          */
 946         while (num_frames--) {
 947                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 948                 if (IS_ERR(bh))
 949                         return PTR_ERR(bh);
 950                 p++;
 951                 brelse(p->bh);
 952                 p->bh = bh;
 953                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 954         }
 955         return 1;
 956 }
 957
 958
 959 /*
 960  * This function fills a red-black tree with information from a
 961  * directory block.  It returns the number directory entries loaded
 962  * into the tree.  If there is an error it is returned in err.
 963  */
 964 static int htree_dirblock_to_tree(struct file *dir_file,
 965                                   struct inode *dir, ext4_lblk_t block,
 966                                   struct dx_hash_info *hinfo,
 967                                   __u32 start_hash, __u32 start_minor_hash)
 968 {
 969         struct buffer_head *bh;
 970         struct ext4_dir_entry_2 *de, *top;
 971         int err = 0, count = 0;
 972         struct ext4_fname_crypto_ctx *ctx = NULL;
 973         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
 974
 975         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 976                                                         (unsigned long)block));
 977         bh = ext4_read_dirblock(dir, block, DIRENT);
 978         if (IS_ERR(bh))
 979                 return PTR_ERR(bh);
 980
 981         de = (struct ext4_dir_entry_2 *) bh->b_data;
 982         top = (struct ext4_dir_entry_2 *) ((char *) de +
 983                                            dir->i_sb->s_blocksize -
 984                                            EXT4_DIR_REC_LEN(0));
 985 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 986         /* Check if the directory is encrypted */
 987         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
 988         if (IS_ERR(ctx)) {
 989                 err = PTR_ERR(ctx);
 990                 brelse(bh);
 991                 return err;
 992         }
 993         if (ctx != NULL) {
 994                 err = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
 995                                                      &fname_crypto_str);
 996                 if (err < 0) {
 997                         ext4_put_fname_crypto_ctx(&ctx);
 998                         brelse(bh);
 999                         return err;
1000                 }
1001         }
1002 #endif
1003         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1004                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1005                                 bh->b_data, bh->b_size,
1006                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1007                                          + ((char *)de - bh->b_data))) {
1008                         /* silently ignore the rest of the block */
1009                         break;
1010                 }
1011 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1012                 err = ext4_fname_disk_to_hash(ctx, de, hinfo);
1013                 if (err < 0) {
1014                         count = err;
1015                         goto errout;
1016                 }
1017 #else
1018                 ext4fs_dirhash(de->name, de->name_len, hinfo);
1019 #endif
1020                 if ((hinfo->hash < start_hash) ||
1021                     ((hinfo->hash == start_hash) &&
1022                      (hinfo->minor_hash < start_minor_hash)))
1023                         continue;
1024                 if (de->inode == 0)
1025                         continue;
1026                 if (ctx == NULL) {
1027                         /* Directory is not encrypted */
1028                         tmp_str.name = de->name;
1029                         tmp_str.len = de->name_len;
1030                         err = ext4_htree_store_dirent(dir_file,
1031                                    hinfo->hash, hinfo->minor_hash, de,
1032                                    &tmp_str);
1033                 } else {
1034                         /* Directory is encrypted */
1035                         err = ext4_fname_disk_to_usr(ctx, de,
1036                                                      &fname_crypto_str);
1037                         if (err < 0) {
1038                                 count = err;
1039                                 goto errout;
1040                         }
1041                         err = ext4_htree_store_dirent(dir_file,
1042                                    hinfo->hash, hinfo->minor_hash, de,
1043                                         &fname_crypto_str);
1044                 }
1045                 if (err != 0) {
1046                         count = err;
1047                         goto errout;
1048                 }
1049                 count++;
1050         }
1051 errout:
1052         brelse(bh);
1053 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1054         ext4_put_fname_crypto_ctx(&ctx);
1055         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1056 #endif
1057         return count;
1058 }
1059
1060
1061 /*
1062  * This function fills a red-black tree with information from a
1063  * directory.  We start scanning the directory in hash order, starting
1064  * at start_hash and start_minor_hash.
1065  *
1066  * This function returns the number of entries inserted into the tree,
1067  * or a negative error code.
1068  */
1069 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1070                          __u32 start_minor_hash, __u32 *next_hash)
1071 {
1072         struct dx_hash_info hinfo;
1073         struct ext4_dir_entry_2 *de;
1074         struct dx_frame frames[2], *frame;
1075         struct inode *dir;
1076         ext4_lblk_t block;
1077         int count = 0;
1078         int ret, err;
1079         __u32 hashval;
1080         struct ext4_str tmp_str;
1081
1082         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1083                        start_hash, start_minor_hash));
1084         dir = file_inode(dir_file);
1085         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1086                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1087                 if (hinfo.hash_version <= DX_HASH_TEA)
1088                         hinfo.hash_version +=
1089                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1090                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1091                 if (ext4_has_inline_data(dir)) {
1092                         int has_inline_data = 1;
1093                         count = htree_inlinedir_to_tree(dir_file, dir, 0,
1094                                                         &hinfo, start_hash,
1095                                                         start_minor_hash,
1096                                                         &has_inline_data);
1097                         if (has_inline_data) {
1098                                 *next_hash = ~0;
1099                                 return count;
1100                         }
1101                 }
1102                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1103                                                start_hash, start_minor_hash);
1104                 *next_hash = ~0;
1105                 return count;
1106         }
1107         hinfo.hash = start_hash;
1108         hinfo.minor_hash = 0;
1109         frame = dx_probe(NULL, dir, &hinfo, frames);
1110         if (IS_ERR(frame))
1111                 return PTR_ERR(frame);
1112
1113         /* Add '.' and '..' from the htree header */
1114         if (!start_hash && !start_minor_hash) {
1115                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1116                 tmp_str.name = de->name;
1117                 tmp_str.len = de->name_len;
1118                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1119                                               de, &tmp_str);
1120                 if (err != 0)
1121                         goto errout;
1122                 count++;
1123         }
1124         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1125                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1126                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1127                 tmp_str.name = de->name;
1128                 tmp_str.len = de->name_len;
1129                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1130                                               de, &tmp_str);
1131                 if (err != 0)
1132                         goto errout;
1133                 count++;
1134         }
1135
1136         while (1) {
1137                 block = dx_get_block(frame->at);
1138                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1139                                              start_hash, start_minor_hash);
1140                 if (ret < 0) {
1141                         err = ret;
1142                         goto errout;
1143                 }
1144                 count += ret;
1145                 hashval = ~0;
1146                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1147                                             frame, frames, &hashval);
1148                 *next_hash = hashval;
1149                 if (ret < 0) {
1150                         err = ret;
1151                         goto errout;
1152                 }
1153                 /*
1154                  * Stop if:  (a) there are no more entries, or
1155                  * (b) we have inserted at least one entry and the
1156                  * next hash value is not a continuation
1157                  */
1158                 if ((ret == 0) ||
1159                     (count && ((hashval & 1) == 0)))
1160                         break;
1161         }
1162         dx_release(frames);
1163         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1164                        "next hash: %x\n", count, *next_hash));
1165         return count;
1166 errout:
1167         dx_release(frames);
1168         return (err);
1169 }
1170
1171 static inline int search_dirblock(struct buffer_head *bh,
1172                                   struct inode *dir,
1173                                   const struct qstr *d_name,
1174                                   unsigned int offset,
1175                                   struct ext4_dir_entry_2 **res_dir)
1176 {
1177         return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1178                           d_name, offset, res_dir);
1179 }
1180
1181 /*
1182  * Directory block splitting, compacting
1183  */
1184
1185 /*
1186  * Create map of hash values, offsets, and sizes, stored at end of block.
1187  * Returns number of entries mapped.
1188  */
1189 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1190                        unsigned blocksize, struct dx_hash_info *hinfo,
1191                        struct dx_map_entry *map_tail)
1192 {
1193         int count = 0;
1194         char *base = (char *) de;
1195         struct dx_hash_info h = *hinfo;
1196 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1197         struct ext4_fname_crypto_ctx *ctx = NULL;
1198         int err;
1199
1200         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1201         if (IS_ERR(ctx))
1202                 return PTR_ERR(ctx);
1203 #endif
1204
1205         while ((char *) de < base + blocksize) {
1206                 if (de->name_len && de->inode) {
1207 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1208                         err = ext4_fname_disk_to_hash(ctx, de, &h);
1209                         if (err < 0) {
1210                                 ext4_put_fname_crypto_ctx(&ctx);
1211                                 return err;
1212                         }
1213 #else
1214                         ext4fs_dirhash(de->name, de->name_len, &h);
1215 #endif
1216                         map_tail--;
1217                         map_tail->hash = h.hash;
1218                         map_tail->offs = ((char *) de - base)>>2;
1219                         map_tail->size = le16_to_cpu(de->rec_len);
1220                         count++;
1221                         cond_resched();
1222                 }
1223                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1224                 de = ext4_next_entry(de, blocksize);
1225         }
1226 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1227         ext4_put_fname_crypto_ctx(&ctx);
1228 #endif
1229         return count;
1230 }
1231
1232 /* Sort map by hash value */
1233 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1234 {
1235         struct dx_map_entry *p, *q, *top = map + count - 1;
1236         int more;
1237         /* Combsort until bubble sort doesn't suck */
1238         while (count > 2) {
1239                 count = count*10/13;
1240                 if (count - 9 < 2) /* 9, 10 -> 11 */
1241                         count = 11;
1242                 for (p = top, q = p - count; q >= map; p--, q--)
1243                         if (p->hash < q->hash)
1244                                 swap(*p, *q);
1245         }
1246         /* Garden variety bubble sort */
1247         do {
1248                 more = 0;
1249                 q = top;
1250                 while (q-- > map) {
1251                         if (q[1].hash >= q[0].hash)
1252                                 continue;
1253                         swap(*(q+1), *q);
1254                         more = 1;
1255                 }
1256         } while(more);
1257 }
1258
1259 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1260 {
1261         struct dx_entry *entries = frame->entries;
1262         struct dx_entry *old = frame->at, *new = old + 1;
1263         int count = dx_get_count(entries);
1264
1265         assert(count < dx_get_limit(entries));
1266         assert(old < entries + count);
1267         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1268         dx_set_hash(new, hash);
1269         dx_set_block(new, block);
1270         dx_set_count(entries, count + 1);
1271 }
1272
1273 /*
1274  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1275  *
1276  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1277  * `de != NULL' is guaranteed by caller.
1278  */
1279 static inline int ext4_match(struct ext4_fname_crypto_ctx *ctx,
1280                              struct ext4_str *fname_crypto_str,
1281                              int len, const char * const name,
1282                              struct ext4_dir_entry_2 *de)
1283 {
1284         int res;
1285
1286         if (!de->inode)
1287                 return 0;
1288
1289 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1290         if (ctx) {
1291                 /* Directory is encrypted */
1292                 res = ext4_fname_disk_to_usr(ctx, de, fname_crypto_str);
1293                 if (res < 0)
1294                         return res;
1295                 if (len != res)
1296                         return 0;
1297                 res = memcmp(name, fname_crypto_str->name, len);
1298                 return (res == 0) ? 1 : 0;
1299         }
1300 #endif
1301         if (len != de->name_len)
1302                 return 0;
1303         res = memcmp(name, de->name, len);
1304         return (res == 0) ? 1 : 0;
1305 }
1306
1307 /*
1308  * Returns 0 if not found, -1 on failure, and 1 on success
1309  */
1310 int search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1311                struct inode *dir, const struct qstr *d_name,
1312                unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1313 {
1314         struct ext4_dir_entry_2 * de;
1315         char * dlimit;
1316         int de_len;
1317         const char *name = d_name->name;
1318         int namelen = d_name->len;
1319         struct ext4_fname_crypto_ctx *ctx = NULL;
1320         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1321         int res;
1322
1323         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1324         if (IS_ERR(ctx))
1325                 return -1;
1326
1327         if (ctx != NULL) {
1328                 /* Allocate buffer to hold maximum name length */
1329                 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
1330                                                      &fname_crypto_str);
1331                 if (res < 0) {
1332                         ext4_put_fname_crypto_ctx(&ctx);
1333                         return -1;
1334                 }
1335         }
1336
1337         de = (struct ext4_dir_entry_2 *)search_buf;
1338         dlimit = search_buf + buf_size;
1339         while ((char *) de < dlimit) {
1340                 /* this code is executed quadratically often */
1341                 /* do minimal checking `by hand' */
1342                 if ((char *) de + de->name_len <= dlimit) {
1343                         res = ext4_match(ctx, &fname_crypto_str, namelen,
1344                                          name, de);
1345                         if (res < 0) {
1346                                 res = -1;
1347                                 goto return_result;
1348                         }
1349                         if (res > 0) {
1350                                 /* found a match - just to be sure, do
1351                                  * a full check */
1352                                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1353                                                 bh->b_data,
1354                                                  bh->b_size, offset)) {
1355                                         res = -1;
1356                                         goto return_result;
1357                                 }
1358                                 *res_dir = de;
1359                                 res = 1;
1360                                 goto return_result;
1361                         }
1362
1363                 }
1364                 /* prevent looping on a bad block */
1365                 de_len = ext4_rec_len_from_disk(de->rec_len,
1366                                                 dir->i_sb->s_blocksize);
1367                 if (de_len <= 0) {
1368                         res = -1;
1369                         goto return_result;
1370                 }
1371                 offset += de_len;
1372                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1373         }
1374
1375         res = 0;
1376 return_result:
1377         ext4_put_fname_crypto_ctx(&ctx);
1378         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1379         return res;
1380 }
1381
1382 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1383                                struct ext4_dir_entry *de)
1384 {
1385         struct super_block *sb = dir->i_sb;
1386
1387         if (!is_dx(dir))
1388                 return 0;
1389         if (block == 0)
1390                 return 1;
1391         if (de->inode == 0 &&
1392             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1393                         sb->s_blocksize)
1394                 return 1;
1395         return 0;
1396 }
1397
1398 /*
1399  *      ext4_find_entry()
1400  *
1401  * finds an entry in the specified directory with the wanted name. It
1402  * returns the cache buffer in which the entry was found, and the entry
1403  * itself (as a parameter - res_dir). It does NOT read the inode of the
1404  * entry - you'll have to do that yourself if you want to.
1405  *
1406  * The returned buffer_head has ->b_count elevated.  The caller is expected
1407  * to brelse() it when appropriate.
1408  */
1409 static struct buffer_head * ext4_find_entry (struct inode *dir,
1410                                         const struct qstr *d_name,
1411                                         struct ext4_dir_entry_2 **res_dir,
1412                                         int *inlined)
1413 {
1414         struct super_block *sb;
1415         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1416         struct buffer_head *bh, *ret = NULL;
1417         ext4_lblk_t start, block, b;
1418         const u8 *name = d_name->name;
1419         int ra_max = 0;         /* Number of bh's in the readahead
1420                                    buffer, bh_use[] */
1421         int ra_ptr = 0;         /* Current index into readahead
1422                                    buffer */
1423         int num = 0;
1424         ext4_lblk_t  nblocks;
1425         int i, namelen;
1426
1427         *res_dir = NULL;
1428         sb = dir->i_sb;
1429         namelen = d_name->len;
1430         if (namelen > EXT4_NAME_LEN)
1431                 return NULL;
1432
1433         if (ext4_has_inline_data(dir)) {
1434                 int has_inline_data = 1;
1435                 ret = ext4_find_inline_entry(dir, d_name, res_dir,
1436                                              &has_inline_data);
1437                 if (has_inline_data) {
1438                         if (inlined)
1439                                 *inlined = 1;
1440                         return ret;
1441                 }
1442         }
1443
1444         if ((namelen <= 2) && (name[0] == '.') &&
1445             (name[1] == '.' || name[1] == '\0')) {
1446                 /*
1447                  * "." or ".." will only be in the first block
1448                  * NFS may look up ".."; "." should be handled by the VFS
1449                  */
1450                 block = start = 0;
1451                 nblocks = 1;
1452                 goto restart;
1453         }
1454         if (is_dx(dir)) {
1455                 bh = ext4_dx_find_entry(dir, d_name, res_dir);
1456                 /*
1457                  * On success, or if the error was file not found,
1458                  * return.  Otherwise, fall back to doing a search the
1459                  * old fashioned way.
1460                  */
1461                 if (!IS_ERR(bh) || PTR_ERR(bh) != ERR_BAD_DX_DIR)
1462                         return bh;
1463                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1464                                "falling back\n"));
1465         }
1466         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1467         start = EXT4_I(dir)->i_dir_start_lookup;
1468         if (start >= nblocks)
1469                 start = 0;
1470         block = start;
1471 restart:
1472         do {
1473                 /*
1474                  * We deal with the read-ahead logic here.
1475                  */
1476                 if (ra_ptr >= ra_max) {
1477                         /* Refill the readahead buffer */
1478                         ra_ptr = 0;
1479                         b = block;
1480                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1481                                 /*
1482                                  * Terminate if we reach the end of the
1483                                  * directory and must wrap, or if our
1484                                  * search has finished at this block.
1485                                  */
1486                                 if (b >= nblocks || (num && block == start)) {
1487                                         bh_use[ra_max] = NULL;
1488                                         break;
1489                                 }
1490                                 num++;
1491                                 bh = ext4_getblk(NULL, dir, b++, 0);
1492                                 if (unlikely(IS_ERR(bh))) {
1493                                         if (ra_max == 0)
1494                                                 return bh;
1495                                         break;
1496                                 }
1497                                 bh_use[ra_max] = bh;
1498                                 if (bh)
1499                                         ll_rw_block(READ | REQ_META | REQ_PRIO,
1500                                                     1, &bh);
1501                         }
1502                 }
1503                 if ((bh = bh_use[ra_ptr++]) == NULL)
1504                         goto next;
1505                 wait_on_buffer(bh);
1506                 if (!buffer_uptodate(bh)) {
1507                         /* read error, skip block & hope for the best */
1508                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1509                                          (unsigned long) block);
1510                         brelse(bh);
1511                         goto next;
1512                 }
1513                 if (!buffer_verified(bh) &&
1514                     !is_dx_internal_node(dir, block,
1515                                          (struct ext4_dir_entry *)bh->b_data) &&
1516                     !ext4_dirent_csum_verify(dir,
1517                                 (struct ext4_dir_entry *)bh->b_data)) {
1518                         EXT4_ERROR_INODE(dir, "checksumming directory "
1519                                          "block %lu", (unsigned long)block);
1520                         brelse(bh);
1521                         goto next;
1522                 }
1523                 set_buffer_verified(bh);
1524                 i = search_dirblock(bh, dir, d_name,
1525                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1526                 if (i == 1) {
1527                         EXT4_I(dir)->i_dir_start_lookup = block;
1528                         ret = bh;
1529                         goto cleanup_and_exit;
1530                 } else {
1531                         brelse(bh);
1532                         if (i < 0)
1533                                 goto cleanup_and_exit;
1534                 }
1535         next:
1536                 if (++block >= nblocks)
1537                         block = 0;
1538         } while (block != start);
1539
1540         /*
1541          * If the directory has grown while we were searching, then
1542          * search the last part of the directory before giving up.
1543          */
1544         block = nblocks;
1545         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1546         if (block < nblocks) {
1547                 start = 0;
1548                 goto restart;
1549         }
1550
1551 cleanup_and_exit:
1552         /* Clean up the read-ahead blocks */
1553         for (; ra_ptr < ra_max; ra_ptr++)
1554                 brelse(bh_use[ra_ptr]);
1555         return ret;
1556 }
1557
1558 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1559                        struct ext4_dir_entry_2 **res_dir)
1560 {
1561         struct super_block * sb = dir->i_sb;
1562         struct dx_hash_info     hinfo;
1563         struct dx_frame frames[2], *frame;
1564         struct buffer_head *bh;
1565         ext4_lblk_t block;
1566         int retval;
1567
1568 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1569         *res_dir = NULL;
1570 #endif
1571         frame = dx_probe(d_name, dir, &hinfo, frames);
1572         if (IS_ERR(frame))
1573                 return (struct buffer_head *) frame;
1574         do {
1575                 block = dx_get_block(frame->at);
1576                 bh = ext4_read_dirblock(dir, block, DIRENT);
1577                 if (IS_ERR(bh))
1578                         goto errout;
1579
1580                 retval = search_dirblock(bh, dir, d_name,
1581                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1582                                          res_dir);
1583                 if (retval == 1)
1584                         goto success;
1585                 brelse(bh);
1586                 if (retval == -1) {
1587                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1588                         goto errout;
1589                 }
1590
1591                 /* Check to see if we should continue to search */
1592                 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1593                                                frames, NULL);
1594                 if (retval < 0) {
1595                         ext4_warning(sb,
1596                              "error %d reading index page in directory #%lu",
1597                              retval, dir->i_ino);
1598                         bh = ERR_PTR(retval);
1599                         goto errout;
1600                 }
1601         } while (retval == 1);
1602
1603         bh = NULL;
1604 errout:
1605         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1606 success:
1607         dx_release(frames);
1608         return bh;
1609 }
1610
1611 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1612 {
1613         struct inode *inode;
1614         struct ext4_dir_entry_2 *de;
1615         struct buffer_head *bh;
1616
1617         if (dentry->d_name.len > EXT4_NAME_LEN)
1618                 return ERR_PTR(-ENAMETOOLONG);
1619
1620         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1621         if (IS_ERR(bh))
1622                 return (struct dentry *) bh;
1623         inode = NULL;
1624         if (bh) {
1625                 __u32 ino = le32_to_cpu(de->inode);
1626                 brelse(bh);
1627                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1628                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1629                         return ERR_PTR(-EIO);
1630                 }
1631                 if (unlikely(ino == dir->i_ino)) {
1632                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1633                                          dentry);
1634                         return ERR_PTR(-EIO);
1635                 }
1636                 inode = ext4_iget_normal(dir->i_sb, ino);
1637                 if (inode == ERR_PTR(-ESTALE)) {
1638                         EXT4_ERROR_INODE(dir,
1639                                          "deleted inode referenced: %u",
1640                                          ino);
1641                         return ERR_PTR(-EIO);
1642                 }
1643                 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1644                     (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1645                      S_ISLNK(inode->i_mode)) &&
1646                     !ext4_is_child_context_consistent_with_parent(dir,
1647                                                                   inode)) {
1648                         iput(inode);
1649                         ext4_warning(inode->i_sb,
1650                                      "Inconsistent encryption contexts: %lu/%lu\n",
1651                                      (unsigned long) dir->i_ino,
1652                                      (unsigned long) inode->i_ino);
1653                         return ERR_PTR(-EPERM);
1654                 }
1655         }
1656         return d_splice_alias(inode, dentry);
1657 }
1658
1659
1660 struct dentry *ext4_get_parent(struct dentry *child)
1661 {
1662         __u32 ino;
1663         static const struct qstr dotdot = QSTR_INIT("..", 2);
1664         struct ext4_dir_entry_2 * de;
1665         struct buffer_head *bh;
1666
1667         bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL);
1668         if (IS_ERR(bh))
1669                 return (struct dentry *) bh;
1670         if (!bh)
1671                 return ERR_PTR(-ENOENT);
1672         ino = le32_to_cpu(de->inode);
1673         brelse(bh);
1674
1675         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1676                 EXT4_ERROR_INODE(child->d_inode,
1677                                  "bad parent inode number: %u", ino);
1678                 return ERR_PTR(-EIO);
1679         }
1680
1681         return d_obtain_alias(ext4_iget_normal(child->d_inode->i_sb, ino));
1682 }
1683
1684 /*
1685  * Move count entries from end of map between two memory locations.
1686  * Returns pointer to last entry moved.
1687  */
1688 static struct ext4_dir_entry_2 *
1689 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1690                 unsigned blocksize)
1691 {
1692         unsigned rec_len = 0;
1693
1694         while (count--) {
1695                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1696                                                 (from + (map->offs<<2));
1697                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1698                 memcpy (to, de, rec_len);
1699                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1700                                 ext4_rec_len_to_disk(rec_len, blocksize);
1701                 de->inode = 0;
1702                 map++;
1703                 to += rec_len;
1704         }
1705         return (struct ext4_dir_entry_2 *) (to - rec_len);
1706 }
1707
1708 /*
1709  * Compact each dir entry in the range to the minimal rec_len.
1710  * Returns pointer to last entry in range.
1711  */
1712 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1713 {
1714         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1715         unsigned rec_len = 0;
1716
1717         prev = to = de;
1718         while ((char*)de < base + blocksize) {
1719                 next = ext4_next_entry(de, blocksize);
1720                 if (de->inode && de->name_len) {
1721                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1722                         if (de > to)
1723                                 memmove(to, de, rec_len);
1724                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1725                         prev = to;
1726                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1727                 }
1728                 de = next;
1729         }
1730         return prev;
1731 }
1732
1733 /*
1734  * Split a full leaf block to make room for a new dir entry.
1735  * Allocate a new block, and move entries so that they are approx. equally full.
1736  * Returns pointer to de in block into which the new entry will be inserted.
1737  */
1738 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1739                         struct buffer_head **bh,struct dx_frame *frame,
1740                         struct dx_hash_info *hinfo)
1741 {
1742         unsigned blocksize = dir->i_sb->s_blocksize;
1743         unsigned count, continued;
1744         struct buffer_head *bh2;
1745         ext4_lblk_t newblock;
1746         u32 hash2;
1747         struct dx_map_entry *map;
1748         char *data1 = (*bh)->b_data, *data2;
1749         unsigned split, move, size;
1750         struct ext4_dir_entry_2 *de = NULL, *de2;
1751         struct ext4_dir_entry_tail *t;
1752         int     csum_size = 0;
1753         int     err = 0, i;
1754
1755         if (ext4_has_metadata_csum(dir->i_sb))
1756                 csum_size = sizeof(struct ext4_dir_entry_tail);
1757
1758         bh2 = ext4_append(handle, dir, &newblock);
1759         if (IS_ERR(bh2)) {
1760                 brelse(*bh);
1761                 *bh = NULL;
1762                 return (struct ext4_dir_entry_2 *) bh2;
1763         }
1764
1765         BUFFER_TRACE(*bh, "get_write_access");
1766         err = ext4_journal_get_write_access(handle, *bh);
1767         if (err)
1768                 goto journal_error;
1769
1770         BUFFER_TRACE(frame->bh, "get_write_access");
1771         err = ext4_journal_get_write_access(handle, frame->bh);
1772         if (err)
1773                 goto journal_error;
1774
1775         data2 = bh2->b_data;
1776
1777         /* create map in the end of data2 block */
1778         map = (struct dx_map_entry *) (data2 + blocksize);
1779         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1780                              blocksize, hinfo, map);
1781         map -= count;
1782         dx_sort_map(map, count);
1783         /* Split the existing block in the middle, size-wise */
1784         size = 0;
1785         move = 0;
1786         for (i = count-1; i >= 0; i--) {
1787                 /* is more than half of this entry in 2nd half of the block? */
1788                 if (size + map[i].size/2 > blocksize/2)
1789                         break;
1790                 size += map[i].size;
1791                 move++;
1792         }
1793         /* map index at which we will split */
1794         split = count - move;
1795         hash2 = map[split].hash;
1796         continued = hash2 == map[split - 1].hash;
1797         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1798                         (unsigned long)dx_get_block(frame->at),
1799                                         hash2, split, count-split));
1800
1801         /* Fancy dance to stay within two buffers */
1802         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1803                               blocksize);
1804         de = dx_pack_dirents(data1, blocksize);
1805         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1806                                            (char *) de,
1807                                            blocksize);
1808         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1809                                             (char *) de2,
1810                                             blocksize);
1811         if (csum_size) {
1812                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1813                 initialize_dirent_tail(t, blocksize);
1814
1815                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1816                 initialize_dirent_tail(t, blocksize);
1817         }
1818
1819         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1820                         blocksize, 1));
1821         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1822                         blocksize, 1));
1823
1824         /* Which block gets the new entry? */
1825         if (hinfo->hash >= hash2) {
1826                 swap(*bh, bh2);
1827                 de = de2;
1828         }
1829         dx_insert_block(frame, hash2 + continued, newblock);
1830         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1831         if (err)
1832                 goto journal_error;
1833         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1834         if (err)
1835                 goto journal_error;
1836         brelse(bh2);
1837         dxtrace(dx_show_index("frame", frame->entries));
1838         return de;
1839
1840 journal_error:
1841         brelse(*bh);
1842         brelse(bh2);
1843         *bh = NULL;
1844         ext4_std_error(dir->i_sb, err);
1845         return ERR_PTR(err);
1846 }
1847
1848 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1849                       struct buffer_head *bh,
1850                       void *buf, int buf_size,
1851                       const char *name, int namelen,
1852                       struct ext4_dir_entry_2 **dest_de)
1853 {
1854         struct ext4_dir_entry_2 *de;
1855         unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
1856         int nlen, rlen;
1857         unsigned int offset = 0;
1858         char *top;
1859         struct ext4_fname_crypto_ctx *ctx = NULL;
1860         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1861         int res;
1862
1863         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1864         if (IS_ERR(ctx))
1865                 return -1;
1866
1867         if (ctx != NULL) {
1868                 /* Calculate record length needed to store the entry */
1869                 res = ext4_fname_crypto_namelen_on_disk(ctx, namelen);
1870                 if (res < 0) {
1871                         ext4_put_fname_crypto_ctx(&ctx);
1872                         return res;
1873                 }
1874                 reclen = EXT4_DIR_REC_LEN(res);
1875
1876                 /* Allocate buffer to hold maximum name length */
1877                 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
1878                                                      &fname_crypto_str);
1879                 if (res < 0) {
1880                         ext4_put_fname_crypto_ctx(&ctx);
1881                         return -1;
1882                 }
1883         }
1884
1885         de = (struct ext4_dir_entry_2 *)buf;
1886         top = buf + buf_size - reclen;
1887         while ((char *) de <= top) {
1888                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1889                                          buf, buf_size, offset)) {
1890                         res = -EIO;
1891                         goto return_result;
1892                 }
1893                 /* Provide crypto context and crypto buffer to ext4 match */
1894                 res = ext4_match(ctx, &fname_crypto_str, namelen, name, de);
1895                 if (res < 0)
1896                         goto return_result;
1897                 if (res > 0) {
1898                         res = -EEXIST;
1899                         goto return_result;
1900                 }
1901                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1902                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1903                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1904                         break;
1905                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1906                 offset += rlen;
1907         }
1908
1909         if ((char *) de > top)
1910                 res = -ENOSPC;
1911         else {
1912                 *dest_de = de;
1913                 res = 0;
1914         }
1915 return_result:
1916         ext4_put_fname_crypto_ctx(&ctx);
1917         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1918         return res;
1919 }
1920
1921 int ext4_insert_dentry(struct inode *dir,
1922                        struct inode *inode,
1923                        struct ext4_dir_entry_2 *de,
1924                        int buf_size,
1925                        const struct qstr *iname,
1926                        const char *name, int namelen)
1927 {
1928
1929         int nlen, rlen;
1930         struct ext4_fname_crypto_ctx *ctx = NULL;
1931         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1932         struct ext4_str tmp_str;
1933         int res;
1934
1935         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1936         if (IS_ERR(ctx))
1937                 return -EIO;
1938         /* By default, the input name would be written to the disk */
1939         tmp_str.name = (unsigned char *)name;
1940         tmp_str.len = namelen;
1941         if (ctx != NULL) {
1942                 /* Directory is encrypted */
1943                 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
1944                                                      &fname_crypto_str);
1945                 if (res < 0) {
1946                         ext4_put_fname_crypto_ctx(&ctx);
1947                         return -ENOMEM;
1948                 }
1949                 res = ext4_fname_usr_to_disk(ctx, iname, &fname_crypto_str);
1950                 if (res < 0) {
1951                         ext4_put_fname_crypto_ctx(&ctx);
1952                         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1953                         return res;
1954                 }
1955                 tmp_str.name = fname_crypto_str.name;
1956                 tmp_str.len = fname_crypto_str.len;
1957         }
1958
1959         nlen = EXT4_DIR_REC_LEN(de->name_len);
1960         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1961         if (de->inode) {
1962                 struct ext4_dir_entry_2 *de1 =
1963                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1964                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1965                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1966                 de = de1;
1967         }
1968         de->file_type = EXT4_FT_UNKNOWN;
1969         de->inode = cpu_to_le32(inode->i_ino);
1970         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1971         de->name_len = tmp_str.len;
1972
1973         memcpy(de->name, tmp_str.name, tmp_str.len);
1974         ext4_put_fname_crypto_ctx(&ctx);
1975         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1976         return 0;
1977 }
1978
1979 /*
1980  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1981  * it points to a directory entry which is guaranteed to be large
1982  * enough for new directory entry.  If de is NULL, then
1983  * add_dirent_to_buf will attempt search the directory block for
1984  * space.  It will return -ENOSPC if no space is available, and -EIO
1985  * and -EEXIST if directory entry already exists.
1986  */
1987 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1988                              struct inode *inode, struct ext4_dir_entry_2 *de,
1989                              struct buffer_head *bh)
1990 {
1991         struct inode    *dir = dentry->d_parent->d_inode;
1992         const char      *name = dentry->d_name.name;
1993         int             namelen = dentry->d_name.len;
1994         unsigned int    blocksize = dir->i_sb->s_blocksize;
1995         int             csum_size = 0;
1996         int             err;
1997
1998         if (ext4_has_metadata_csum(inode->i_sb))
1999                 csum_size = sizeof(struct ext4_dir_entry_tail);
2000
2001         if (!de) {
2002                 err = ext4_find_dest_de(dir, inode,
2003                                         bh, bh->b_data, blocksize - csum_size,
2004                                         name, namelen, &de);
2005                 if (err)
2006                         return err;
2007         }
2008         BUFFER_TRACE(bh, "get_write_access");
2009         err = ext4_journal_get_write_access(handle, bh);
2010         if (err) {
2011                 ext4_std_error(dir->i_sb, err);
2012                 return err;
2013         }
2014
2015         /* By now the buffer is marked for journaling. Due to crypto operations,
2016          * the following function call may fail */
2017         err = ext4_insert_dentry(dir, inode, de, blocksize, &dentry->d_name,
2018                                  name, namelen);
2019         if (err < 0)
2020                 return err;
2021
2022         /*
2023          * XXX shouldn't update any times until successful
2024          * completion of syscall, but too many callers depend
2025          * on this.
2026          *
2027          * XXX similarly, too many callers depend on
2028          * ext4_new_inode() setting the times, but error
2029          * recovery deletes the inode, so the worst that can
2030          * happen is that the times are slightly out of date
2031          * and/or different from the directory change time.
2032          */
2033         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
2034         ext4_update_dx_flag(dir);
2035         dir->i_version++;
2036         ext4_mark_inode_dirty(handle, dir);
2037         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2038         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2039         if (err)
2040                 ext4_std_error(dir->i_sb, err);
2041         return 0;
2042 }
2043
2044 /*
2045  * This converts a one block unindexed directory to a 3 block indexed
2046  * directory, and adds the dentry to the indexed directory.
2047  */
2048 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
2049                             struct inode *inode, struct buffer_head *bh)
2050 {
2051         struct inode    *dir = dentry->d_parent->d_inode;
2052 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2053         struct ext4_fname_crypto_ctx *ctx = NULL;
2054         int res;
2055 #else
2056         const char      *name = dentry->d_name.name;
2057         int             namelen = dentry->d_name.len;
2058 #endif
2059         struct buffer_head *bh2;
2060         struct dx_root  *root;
2061         struct dx_frame frames[2], *frame;
2062         struct dx_entry *entries;
2063         struct ext4_dir_entry_2 *de, *de2;
2064         struct ext4_dir_entry_tail *t;
2065         char            *data1, *top;
2066         unsigned        len;
2067         int             retval;
2068         unsigned        blocksize;
2069         struct dx_hash_info hinfo;
2070         ext4_lblk_t  block;
2071         struct fake_dirent *fde;
2072         int csum_size = 0;
2073
2074 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2075         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
2076         if (IS_ERR(ctx))
2077                 return PTR_ERR(ctx);
2078 #endif
2079
2080         if (ext4_has_metadata_csum(inode->i_sb))
2081                 csum_size = sizeof(struct ext4_dir_entry_tail);
2082
2083         blocksize =  dir->i_sb->s_blocksize;
2084         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2085         BUFFER_TRACE(bh, "get_write_access");
2086         retval = ext4_journal_get_write_access(handle, bh);
2087         if (retval) {
2088                 ext4_std_error(dir->i_sb, retval);
2089                 brelse(bh);
2090                 return retval;
2091         }
2092         root = (struct dx_root *) bh->b_data;
2093
2094         /* The 0th block becomes the root, move the dirents out */
2095         fde = &root->dotdot;
2096         de = (struct ext4_dir_entry_2 *)((char *)fde +
2097                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2098         if ((char *) de >= (((char *) root) + blocksize)) {
2099                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2100                 brelse(bh);
2101                 return -EIO;
2102         }
2103         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2104
2105         /* Allocate new block for the 0th block's dirents */
2106         bh2 = ext4_append(handle, dir, &block);
2107         if (IS_ERR(bh2)) {
2108                 brelse(bh);
2109                 return PTR_ERR(bh2);
2110         }
2111         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2112         data1 = bh2->b_data;
2113
2114         memcpy (data1, de, len);
2115         de = (struct ext4_dir_entry_2 *) data1;
2116         top = data1 + len;
2117         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2118                 de = de2;
2119         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2120                                            (char *) de,
2121                                            blocksize);
2122
2123         if (csum_size) {
2124                 t = EXT4_DIRENT_TAIL(data1, blocksize);
2125                 initialize_dirent_tail(t, blocksize);
2126         }
2127
2128         /* Initialize the root; the dot dirents already exist */
2129         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2130         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2131                                            blocksize);
2132         memset (&root->info, 0, sizeof(root->info));
2133         root->info.info_length = sizeof(root->info);
2134         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2135         entries = root->entries;
2136         dx_set_block(entries, 1);
2137         dx_set_count(entries, 1);
2138         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2139
2140         /* Initialize as for dx_probe */
2141         hinfo.hash_version = root->info.hash_version;
2142         if (hinfo.hash_version <= DX_HASH_TEA)
2143                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2144         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2145 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2146         res = ext4_fname_usr_to_hash(ctx, &dentry->d_name, &hinfo);
2147         if (res < 0) {
2148                 ext4_put_fname_crypto_ctx(&ctx);
2149                 ext4_mark_inode_dirty(handle, dir);
2150                 brelse(bh);
2151                 return res;
2152         }
2153         ext4_put_fname_crypto_ctx(&ctx);
2154 #else
2155         ext4fs_dirhash(name, namelen, &hinfo);
2156 #endif
2157         memset(frames, 0, sizeof(frames));
2158         frame = frames;
2159         frame->entries = entries;
2160         frame->at = entries;
2161         frame->bh = bh;
2162         bh = bh2;
2163
2164         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2165         if (retval)
2166                 goto out_frames;
2167         retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
2168         if (retval)
2169                 goto out_frames;
2170
2171         de = do_split(handle,dir, &bh, frame, &hinfo);
2172         if (IS_ERR(de)) {
2173                 retval = PTR_ERR(de);
2174                 goto out_frames;
2175         }
2176         dx_release(frames);
2177
2178         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
2179         brelse(bh);
2180         return retval;
2181 out_frames:
2182         /*
2183          * Even if the block split failed, we have to properly write
2184          * out all the changes we did so far. Otherwise we can end up
2185          * with corrupted filesystem.
2186          */
2187         ext4_mark_inode_dirty(handle, dir);
2188         dx_release(frames);
2189         return retval;
2190 }
2191
2192 /*
2193  *      ext4_add_entry()
2194  *
2195  * adds a file entry to the specified directory, using the same
2196  * semantics as ext4_find_entry(). It returns NULL if it failed.
2197  *
2198  * NOTE!! The inode part of 'de' is left at 0 - which means you
2199  * may not sleep between calling this and putting something into
2200  * the entry, as someone else might have used it while you slept.
2201  */
2202 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2203                           struct inode *inode)
2204 {
2205         struct inode *dir = dentry->d_parent->d_inode;
2206         struct buffer_head *bh = NULL;
2207         struct ext4_dir_entry_2 *de;
2208         struct ext4_dir_entry_tail *t;
2209         struct super_block *sb;
2210         int     retval;
2211         int     dx_fallback=0;
2212         unsigned blocksize;
2213         ext4_lblk_t block, blocks;
2214         int     csum_size = 0;
2215
2216         if (ext4_has_metadata_csum(inode->i_sb))
2217                 csum_size = sizeof(struct ext4_dir_entry_tail);
2218
2219         sb = dir->i_sb;
2220         blocksize = sb->s_blocksize;
2221         if (!dentry->d_name.len)
2222                 return -EINVAL;
2223
2224         if (ext4_has_inline_data(dir)) {
2225                 retval = ext4_try_add_inline_entry(handle, dentry, inode);
2226                 if (retval < 0)
2227                         return retval;
2228                 if (retval == 1) {
2229                         retval = 0;
2230                         goto out;
2231                 }
2232         }
2233
2234         if (is_dx(dir)) {
2235                 retval = ext4_dx_add_entry(handle, dentry, inode);
2236                 if (!retval || (retval != ERR_BAD_DX_DIR))
2237                         goto out;
2238                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2239                 dx_fallback++;
2240                 ext4_mark_inode_dirty(handle, dir);
2241         }
2242         blocks = dir->i_size >> sb->s_blocksize_bits;
2243         for (block = 0; block < blocks; block++) {
2244                 bh = ext4_read_dirblock(dir, block, DIRENT);
2245                 if (IS_ERR(bh))
2246                         return PTR_ERR(bh);
2247
2248                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
2249                 if (retval != -ENOSPC)
2250                         goto out;
2251
2252                 if (blocks == 1 && !dx_fallback &&
2253                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
2254                         retval = make_indexed_dir(handle, dentry, inode, bh);
2255                         bh = NULL; /* make_indexed_dir releases bh */
2256                         goto out;
2257                 }
2258                 brelse(bh);
2259         }
2260         bh = ext4_append(handle, dir, &block);
2261         if (IS_ERR(bh))
2262                 return PTR_ERR(bh);
2263         de = (struct ext4_dir_entry_2 *) bh->b_data;
2264         de->inode = 0;
2265         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2266
2267         if (csum_size) {
2268                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2269                 initialize_dirent_tail(t, blocksize);
2270         }
2271
2272         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
2273 out:
2274         brelse(bh);
2275         if (retval == 0)
2276                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2277         return retval;
2278 }
2279
2280 /*
2281  * Returns 0 for success, or a negative error value
2282  */
2283 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
2284                              struct inode *inode)
2285 {
2286         struct dx_frame frames[2], *frame;
2287         struct dx_entry *entries, *at;
2288         struct dx_hash_info hinfo;
2289         struct buffer_head *bh;
2290         struct inode *dir = dentry->d_parent->d_inode;
2291         struct super_block *sb = dir->i_sb;
2292         struct ext4_dir_entry_2 *de;
2293         int err;
2294
2295         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames);
2296         if (IS_ERR(frame))
2297                 return PTR_ERR(frame);
2298         entries = frame->entries;
2299         at = frame->at;
2300         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2301         if (IS_ERR(bh)) {
2302                 err = PTR_ERR(bh);
2303                 bh = NULL;
2304                 goto cleanup;
2305         }
2306
2307         BUFFER_TRACE(bh, "get_write_access");
2308         err = ext4_journal_get_write_access(handle, bh);
2309         if (err)
2310                 goto journal_error;
2311
2312         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
2313         if (err != -ENOSPC)
2314                 goto cleanup;
2315
2316         /* Block full, should compress but for now just split */
2317         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2318                        dx_get_count(entries), dx_get_limit(entries)));
2319         /* Need to split index? */
2320         if (dx_get_count(entries) == dx_get_limit(entries)) {
2321                 ext4_lblk_t newblock;
2322                 unsigned icount = dx_get_count(entries);
2323                 int levels = frame - frames;
2324                 struct dx_entry *entries2;
2325                 struct dx_node *node2;
2326                 struct buffer_head *bh2;
2327
2328                 if (levels && (dx_get_count(frames->entries) ==
2329                                dx_get_limit(frames->entries))) {
2330                         ext4_warning(sb, "Directory index full!");
2331                         err = -ENOSPC;
2332                         goto cleanup;
2333                 }
2334                 bh2 = ext4_append(handle, dir, &newblock);
2335                 if (IS_ERR(bh2)) {
2336                         err = PTR_ERR(bh2);
2337                         goto cleanup;
2338                 }
2339                 node2 = (struct dx_node *)(bh2->b_data);
2340                 entries2 = node2->entries;
2341                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2342                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2343                                                            sb->s_blocksize);
2344                 BUFFER_TRACE(frame->bh, "get_write_access");
2345                 err = ext4_journal_get_write_access(handle, frame->bh);
2346                 if (err)
2347                         goto journal_error;
2348                 if (levels) {
2349                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2350                         unsigned hash2 = dx_get_hash(entries + icount1);
2351                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2352                                        icount1, icount2));
2353
2354                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2355                         err = ext4_journal_get_write_access(handle,
2356                                                              frames[0].bh);
2357                         if (err)
2358                                 goto journal_error;
2359
2360                         memcpy((char *) entries2, (char *) (entries + icount1),
2361                                icount2 * sizeof(struct dx_entry));
2362                         dx_set_count(entries, icount1);
2363                         dx_set_count(entries2, icount2);
2364                         dx_set_limit(entries2, dx_node_limit(dir));
2365
2366                         /* Which index block gets the new entry? */
2367                         if (at - entries >= icount1) {
2368                                 frame->at = at = at - entries - icount1 + entries2;
2369                                 frame->entries = entries = entries2;
2370                                 swap(frame->bh, bh2);
2371                         }
2372                         dx_insert_block(frames + 0, hash2, newblock);
2373                         dxtrace(dx_show_index("node", frames[1].entries));
2374                         dxtrace(dx_show_index("node",
2375                                ((struct dx_node *) bh2->b_data)->entries));
2376                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2377                         if (err)
2378                                 goto journal_error;
2379                         brelse (bh2);
2380                 } else {
2381                         dxtrace(printk(KERN_DEBUG
2382                                        "Creating second level index...\n"));
2383                         memcpy((char *) entries2, (char *) entries,
2384                                icount * sizeof(struct dx_entry));
2385                         dx_set_limit(entries2, dx_node_limit(dir));
2386
2387                         /* Set up root */
2388                         dx_set_count(entries, 1);
2389                         dx_set_block(entries + 0, newblock);
2390                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2391
2392                         /* Add new access path frame */
2393                         frame = frames + 1;
2394                         frame->at = at = at - entries + entries2;
2395                         frame->entries = entries = entries2;
2396                         frame->bh = bh2;
2397                         err = ext4_journal_get_write_access(handle,
2398                                                              frame->bh);
2399                         if (err)
2400                                 goto journal_error;
2401                 }
2402                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2403                 if (err) {
2404                         ext4_std_error(inode->i_sb, err);
2405                         goto cleanup;
2406                 }
2407         }
2408         de = do_split(handle, dir, &bh, frame, &hinfo);
2409         if (IS_ERR(de)) {
2410                 err = PTR_ERR(de);
2411                 goto cleanup;
2412         }
2413         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2414         goto cleanup;
2415
2416 journal_error:
2417         ext4_std_error(dir->i_sb, err);
2418 cleanup:
2419         brelse(bh);
2420         dx_release(frames);
2421         return err;
2422 }
2423
2424 /*
2425  * ext4_generic_delete_entry deletes a directory entry by merging it
2426  * with the previous entry
2427  */
2428 int ext4_generic_delete_entry(handle_t *handle,
2429                               struct inode *dir,
2430                               struct ext4_dir_entry_2 *de_del,
2431                               struct buffer_head *bh,
2432                               void *entry_buf,
2433                               int buf_size,
2434                               int csum_size)
2435 {
2436         struct ext4_dir_entry_2 *de, *pde;
2437         unsigned int blocksize = dir->i_sb->s_blocksize;
2438         int i;
2439
2440         i = 0;
2441         pde = NULL;
2442         de = (struct ext4_dir_entry_2 *)entry_buf;
2443         while (i < buf_size - csum_size) {
2444                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2445                                          bh->b_data, bh->b_size, i))
2446                         return -EIO;
2447                 if (de == de_del)  {
2448                         if (pde)
2449                                 pde->rec_len = ext4_rec_len_to_disk(
2450                                         ext4_rec_len_from_disk(pde->rec_len,
2451                                                                blocksize) +
2452                                         ext4_rec_len_from_disk(de->rec_len,
2453                                                                blocksize),
2454                                         blocksize);
2455                         else
2456                                 de->inode = 0;
2457                         dir->i_version++;
2458                         return 0;
2459                 }
2460                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2461                 pde = de;
2462                 de = ext4_next_entry(de, blocksize);
2463         }
2464         return -ENOENT;
2465 }
2466
2467 static int ext4_delete_entry(handle_t *handle,
2468                              struct inode *dir,
2469                              struct ext4_dir_entry_2 *de_del,
2470                              struct buffer_head *bh)
2471 {
2472         int err, csum_size = 0;
2473
2474         if (ext4_has_inline_data(dir)) {
2475                 int has_inline_data = 1;
2476                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2477                                                &has_inline_data);
2478                 if (has_inline_data)
2479                         return err;
2480         }
2481
2482         if (ext4_has_metadata_csum(dir->i_sb))
2483                 csum_size = sizeof(struct ext4_dir_entry_tail);
2484
2485         BUFFER_TRACE(bh, "get_write_access");
2486         err = ext4_journal_get_write_access(handle, bh);
2487         if (unlikely(err))
2488                 goto out;
2489
2490         err = ext4_generic_delete_entry(handle, dir, de_del,
2491                                         bh, bh->b_data,
2492                                         dir->i_sb->s_blocksize, csum_size);
2493         if (err)
2494                 goto out;
2495
2496         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2497         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2498         if (unlikely(err))
2499                 goto out;
2500
2501         return 0;
2502 out:
2503         if (err != -ENOENT)
2504                 ext4_std_error(dir->i_sb, err);
2505         return err;
2506 }
2507
2508 /*
2509  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2510  * since this indicates that nlinks count was previously 1.
2511  */
2512 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2513 {
2514         inc_nlink(inode);
2515         if (is_dx(inode) && inode->i_nlink > 1) {
2516                 /* limit is 16-bit i_links_count */
2517                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2518                         set_nlink(inode, 1);
2519                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2520                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2521                 }
2522         }
2523 }
2524
2525 /*
2526  * If a directory had nlink == 1, then we should let it be 1. This indicates
2527  * directory has >EXT4_LINK_MAX subdirs.
2528  */
2529 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2530 {
2531         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2532                 drop_nlink(inode);
2533 }
2534
2535
2536 static int ext4_add_nondir(handle_t *handle,
2537                 struct dentry *dentry, struct inode *inode)
2538 {
2539         int err = ext4_add_entry(handle, dentry, inode);
2540         if (!err) {
2541                 ext4_mark_inode_dirty(handle, inode);
2542                 unlock_new_inode(inode);
2543                 d_instantiate(dentry, inode);
2544                 return 0;
2545         }
2546         drop_nlink(inode);
2547         unlock_new_inode(inode);
2548         iput(inode);
2549         return err;
2550 }
2551
2552 /*
2553  * By the time this is called, we already have created
2554  * the directory cache entry for the new file, but it
2555  * is so far negative - it has no inode.
2556  *
2557  * If the create succeeds, we fill in the inode information
2558  * with d_instantiate().
2559  */
2560 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2561                        bool excl)
2562 {
2563         handle_t *handle;
2564         struct inode *inode;
2565         int err, credits, retries = 0;
2566
2567         dquot_initialize(dir);
2568
2569         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2570                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2571 retry:
2572         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2573                                             NULL, EXT4_HT_DIR, credits);
2574         handle = ext4_journal_current_handle();
2575         err = PTR_ERR(inode);
2576         if (!IS_ERR(inode)) {
2577                 inode->i_op = &ext4_file_inode_operations;
2578                 inode->i_fop = &ext4_file_operations;
2579                 ext4_set_aops(inode);
2580                 err = 0;
2581 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2582                 if (!err && (ext4_encrypted_inode(dir) ||
2583                              DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)))) {
2584                         err = ext4_inherit_context(dir, inode);
2585                         if (err) {
2586                                 clear_nlink(inode);
2587                                 unlock_new_inode(inode);
2588                                 iput(inode);
2589                         }
2590                 }
2591 #endif
2592                 if (!err)
2593                         err = ext4_add_nondir(handle, dentry, inode);
2594                 if (!err && IS_DIRSYNC(dir))
2595                         ext4_handle_sync(handle);
2596         }
2597         if (handle)
2598                 ext4_journal_stop(handle);
2599         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2600                 goto retry;
2601         return err;
2602 }
2603
2604 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2605                       umode_t mode, dev_t rdev)
2606 {
2607         handle_t *handle;
2608         struct inode *inode;
2609         int err, credits, retries = 0;
2610
2611         if (!new_valid_dev(rdev))
2612                 return -EINVAL;
2613
2614         dquot_initialize(dir);
2615
2616         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2617                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2618 retry:
2619         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2620                                             NULL, EXT4_HT_DIR, credits);
2621         handle = ext4_journal_current_handle();
2622         err = PTR_ERR(inode);
2623         if (!IS_ERR(inode)) {
2624                 init_special_inode(inode, inode->i_mode, rdev);
2625                 inode->i_op = &ext4_special_inode_operations;
2626                 err = ext4_add_nondir(handle, dentry, inode);
2627                 if (!err && IS_DIRSYNC(dir))
2628                         ext4_handle_sync(handle);
2629         }
2630         if (handle)
2631                 ext4_journal_stop(handle);
2632         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2633                 goto retry;
2634         return err;
2635 }
2636
2637 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2638 {
2639         handle_t *handle;
2640         struct inode *inode;
2641         int err, retries = 0;
2642
2643         dquot_initialize(dir);
2644
2645 retry:
2646         inode = ext4_new_inode_start_handle(dir, mode,
2647                                             NULL, 0, NULL,
2648                                             EXT4_HT_DIR,
2649                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2650                           4 + EXT4_XATTR_TRANS_BLOCKS);
2651         handle = ext4_journal_current_handle();
2652         err = PTR_ERR(inode);
2653         if (!IS_ERR(inode)) {
2654                 inode->i_op = &ext4_file_inode_operations;
2655                 inode->i_fop = &ext4_file_operations;
2656                 ext4_set_aops(inode);
2657                 d_tmpfile(dentry, inode);
2658                 err = ext4_orphan_add(handle, inode);
2659                 if (err)
2660                         goto err_unlock_inode;
2661                 mark_inode_dirty(inode);
2662                 unlock_new_inode(inode);
2663         }
2664         if (handle)
2665                 ext4_journal_stop(handle);
2666         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2667                 goto retry;
2668         return err;
2669 err_unlock_inode:
2670         ext4_journal_stop(handle);
2671         unlock_new_inode(inode);
2672         return err;
2673 }
2674
2675 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2676                           struct ext4_dir_entry_2 *de,
2677                           int blocksize, int csum_size,
2678                           unsigned int parent_ino, int dotdot_real_len)
2679 {
2680         de->inode = cpu_to_le32(inode->i_ino);
2681         de->name_len = 1;
2682         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2683                                            blocksize);
2684         strcpy(de->name, ".");
2685         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2686
2687         de = ext4_next_entry(de, blocksize);
2688         de->inode = cpu_to_le32(parent_ino);
2689         de->name_len = 2;
2690         if (!dotdot_real_len)
2691                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2692                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2693                                         blocksize);
2694         else
2695                 de->rec_len = ext4_rec_len_to_disk(
2696                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2697         strcpy(de->name, "..");
2698         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2699
2700         return ext4_next_entry(de, blocksize);
2701 }
2702
2703 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2704                              struct inode *inode)
2705 {
2706         struct buffer_head *dir_block = NULL;
2707         struct ext4_dir_entry_2 *de;
2708         struct ext4_dir_entry_tail *t;
2709         ext4_lblk_t block = 0;
2710         unsigned int blocksize = dir->i_sb->s_blocksize;
2711         int csum_size = 0;
2712         int err;
2713
2714         if (ext4_has_metadata_csum(dir->i_sb))
2715                 csum_size = sizeof(struct ext4_dir_entry_tail);
2716
2717         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2718                 err = ext4_try_create_inline_dir(handle, dir, inode);
2719                 if (err < 0 && err != -ENOSPC)
2720                         goto out;
2721                 if (!err)
2722                         goto out;
2723         }
2724
2725         inode->i_size = 0;
2726         dir_block = ext4_append(handle, inode, &block);
2727         if (IS_ERR(dir_block))
2728                 return PTR_ERR(dir_block);
2729         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2730         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2731         set_nlink(inode, 2);
2732         if (csum_size) {
2733                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2734                 initialize_dirent_tail(t, blocksize);
2735         }
2736
2737         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2738         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2739         if (err)
2740                 goto out;
2741         set_buffer_verified(dir_block);
2742 out:
2743         brelse(dir_block);
2744         return err;
2745 }
2746
2747 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2748 {
2749         handle_t *handle;
2750         struct inode *inode;
2751         int err, credits, retries = 0;
2752
2753         if (EXT4_DIR_LINK_MAX(dir))
2754                 return -EMLINK;
2755
2756         dquot_initialize(dir);
2757
2758         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2759                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2760 retry:
2761         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2762                                             &dentry->d_name,
2763                                             0, NULL, EXT4_HT_DIR, credits);
2764         handle = ext4_journal_current_handle();
2765         err = PTR_ERR(inode);
2766         if (IS_ERR(inode))
2767                 goto out_stop;
2768
2769         inode->i_op = &ext4_dir_inode_operations;
2770         inode->i_fop = &ext4_dir_operations;
2771         err = ext4_init_new_dir(handle, dir, inode);
2772         if (err)
2773                 goto out_clear_inode;
2774 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2775         if (ext4_encrypted_inode(dir) ||
2776             DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) {
2777                 err = ext4_inherit_context(dir, inode);
2778                 if (err)
2779                         goto out_clear_inode;
2780         }
2781 #endif
2782         err = ext4_mark_inode_dirty(handle, inode);
2783         if (!err)
2784                 err = ext4_add_entry(handle, dentry, inode);
2785         if (err) {
2786 out_clear_inode:
2787                 clear_nlink(inode);
2788                 unlock_new_inode(inode);
2789                 ext4_mark_inode_dirty(handle, inode);
2790                 iput(inode);
2791                 goto out_stop;
2792         }
2793         ext4_inc_count(handle, dir);
2794         ext4_update_dx_flag(dir);
2795         err = ext4_mark_inode_dirty(handle, dir);
2796         if (err)
2797                 goto out_clear_inode;
2798         unlock_new_inode(inode);
2799         d_instantiate(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 int 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         int err = 0;
2821
2822         if (ext4_has_inline_data(inode)) {
2823                 int has_inline_data = 1;
2824
2825                 err = empty_inline_dir(inode, &has_inline_data);
2826                 if (has_inline_data)
2827                         return err;
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 1;
2834         }
2835         bh = ext4_read_dirblock(inode, 0, EITHER);
2836         if (IS_ERR(bh))
2837                 return 1;
2838
2839         de = (struct ext4_dir_entry_2 *) bh->b_data;
2840         de1 = ext4_next_entry(de, sb->s_blocksize);
2841         if (le32_to_cpu(de->inode) != inode->i_ino ||
2842                         !le32_to_cpu(de1->inode) ||
2843                         strcmp(".", de->name) ||
2844                         strcmp("..", de1->name)) {
2845                 ext4_warning(inode->i_sb,
2846                              "bad directory (dir #%lu) - no `.' or `..'",
2847                              inode->i_ino);
2848                 brelse(bh);
2849                 return 1;
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                         err = 0;
2858                         brelse(bh);
2859                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2860                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2861                         if (IS_ERR(bh))
2862                                 return 1;
2863                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2864                 }
2865                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2866                                          bh->b_data, bh->b_size, offset)) {
2867                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2868                                                          sb->s_blocksize);
2869                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2870                         continue;
2871                 }
2872                 if (le32_to_cpu(de->inode)) {
2873                         brelse(bh);
2874                         return 0;
2875                 }
2876                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2877                 de = ext4_next_entry(de, sb->s_blocksize);
2878         }
2879         brelse(bh);
2880         return 1;
2881 }
2882
2883 /*
2884  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2885  * such inodes, starting at the superblock, in case we crash before the
2886  * file is closed/deleted, or in case the inode truncate spans multiple
2887  * transactions and the last transaction is not recovered after a crash.
2888  *
2889  * At filesystem recovery time, we walk this list deleting unlinked
2890  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2891  *
2892  * Orphan list manipulation functions must be called under i_mutex unless
2893  * we are just creating the inode or deleting it.
2894  */
2895 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2896 {
2897         struct super_block *sb = inode->i_sb;
2898         struct ext4_sb_info *sbi = EXT4_SB(sb);
2899         struct ext4_iloc iloc;
2900         int err = 0, rc;
2901         bool dirty = false;
2902
2903         if (!sbi->s_journal || is_bad_inode(inode))
2904                 return 0;
2905
2906         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2907                      !mutex_is_locked(&inode->i_mutex));
2908         /*
2909          * Exit early if inode already is on orphan list. This is a big speedup
2910          * since we don't have to contend on the global s_orphan_lock.
2911          */
2912         if (!list_empty(&EXT4_I(inode)->i_orphan))
2913                 return 0;
2914
2915         /*
2916          * Orphan handling is only valid for files with data blocks
2917          * being truncated, or files being unlinked. Note that we either
2918          * hold i_mutex, or the inode can not be referenced from outside,
2919          * so i_nlink should not be bumped due to race
2920          */
2921         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2922                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2923
2924         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2925         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2926         if (err)
2927                 goto out;
2928
2929         err = ext4_reserve_inode_write(handle, inode, &iloc);
2930         if (err)
2931                 goto out;
2932
2933         mutex_lock(&sbi->s_orphan_lock);
2934         /*
2935          * Due to previous errors inode may be already a part of on-disk
2936          * orphan list. If so skip on-disk list modification.
2937          */
2938         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2939             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2940                 /* Insert this inode at the head of the on-disk orphan list */
2941                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2942                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2943                 dirty = true;
2944         }
2945         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2946         mutex_unlock(&sbi->s_orphan_lock);
2947
2948         if (dirty) {
2949                 err = ext4_handle_dirty_super(handle, sb);
2950                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2951                 if (!err)
2952                         err = rc;
2953                 if (err) {
2954                         /*
2955                          * We have to remove inode from in-memory list if
2956                          * addition to on disk orphan list failed. Stray orphan
2957                          * list entries can cause panics at unmount time.
2958                          */
2959                         mutex_lock(&sbi->s_orphan_lock);
2960                         list_del(&EXT4_I(inode)->i_orphan);
2961                         mutex_unlock(&sbi->s_orphan_lock);
2962                 }
2963         }
2964         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2965         jbd_debug(4, "orphan inode %lu will point to %d\n",
2966                         inode->i_ino, NEXT_ORPHAN(inode));
2967 out:
2968         ext4_std_error(sb, err);
2969         return err;
2970 }
2971
2972 /*
2973  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2974  * of such inodes stored on disk, because it is finally being cleaned up.
2975  */
2976 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2977 {
2978         struct list_head *prev;
2979         struct ext4_inode_info *ei = EXT4_I(inode);
2980         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2981         __u32 ino_next;
2982         struct ext4_iloc iloc;
2983         int err = 0;
2984
2985         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2986                 return 0;
2987
2988         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2989                      !mutex_is_locked(&inode->i_mutex));
2990         /* Do this quick check before taking global s_orphan_lock. */
2991         if (list_empty(&ei->i_orphan))
2992                 return 0;
2993
2994         if (handle) {
2995                 /* Grab inode buffer early before taking global s_orphan_lock */
2996                 err = ext4_reserve_inode_write(handle, inode, &iloc);
2997         }
2998
2999         mutex_lock(&sbi->s_orphan_lock);
3000         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
3001
3002         prev = ei->i_orphan.prev;
3003         list_del_init(&ei->i_orphan);
3004
3005         /* If we're on an error path, we may not have a valid
3006          * transaction handle with which to update the orphan list on
3007          * disk, but we still need to remove the inode from the linked
3008          * list in memory. */
3009         if (!handle || err) {
3010                 mutex_unlock(&sbi->s_orphan_lock);
3011                 goto out_err;
3012         }
3013
3014         ino_next = NEXT_ORPHAN(inode);
3015         if (prev == &sbi->s_orphan) {
3016                 jbd_debug(4, "superblock will point to %u\n", ino_next);
3017                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
3018                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
3019                 if (err) {
3020                         mutex_unlock(&sbi->s_orphan_lock);
3021                         goto out_brelse;
3022                 }
3023                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
3024                 mutex_unlock(&sbi->s_orphan_lock);
3025                 err = ext4_handle_dirty_super(handle, inode->i_sb);
3026         } else {
3027                 struct ext4_iloc iloc2;
3028                 struct inode *i_prev =
3029                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
3030
3031                 jbd_debug(4, "orphan inode %lu will point to %u\n",
3032                           i_prev->i_ino, ino_next);
3033                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
3034                 if (err) {
3035                         mutex_unlock(&sbi->s_orphan_lock);
3036                         goto out_brelse;
3037                 }
3038                 NEXT_ORPHAN(i_prev) = ino_next;
3039                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
3040                 mutex_unlock(&sbi->s_orphan_lock);
3041         }
3042         if (err)
3043                 goto out_brelse;
3044         NEXT_ORPHAN(inode) = 0;
3045         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
3046 out_err:
3047         ext4_std_error(inode->i_sb, err);
3048         return err;
3049
3050 out_brelse:
3051         brelse(iloc.bh);
3052         goto out_err;
3053 }
3054
3055 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3056 {
3057         int retval;
3058         struct inode *inode;
3059         struct buffer_head *bh;
3060         struct ext4_dir_entry_2 *de;
3061         handle_t *handle = NULL;
3062
3063         /* Initialize quotas before so that eventual writes go in
3064          * separate transaction */
3065         dquot_initialize(dir);
3066         dquot_initialize(dentry->d_inode);
3067
3068         retval = -ENOENT;
3069         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3070         if (IS_ERR(bh))
3071                 return PTR_ERR(bh);
3072         if (!bh)
3073                 goto end_rmdir;
3074
3075         inode = dentry->d_inode;
3076
3077         retval = -EIO;
3078         if (le32_to_cpu(de->inode) != inode->i_ino)
3079                 goto end_rmdir;
3080
3081         retval = -ENOTEMPTY;
3082         if (!ext4_empty_dir(inode))
3083                 goto end_rmdir;
3084
3085         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3086                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3087         if (IS_ERR(handle)) {
3088                 retval = PTR_ERR(handle);
3089                 handle = NULL;
3090                 goto end_rmdir;
3091         }
3092
3093         if (IS_DIRSYNC(dir))
3094                 ext4_handle_sync(handle);
3095
3096         retval = ext4_delete_entry(handle, dir, de, bh);
3097         if (retval)
3098                 goto end_rmdir;
3099         if (!EXT4_DIR_LINK_EMPTY(inode))
3100                 ext4_warning(inode->i_sb,
3101                              "empty directory has too many links (%d)",
3102                              inode->i_nlink);
3103         inode->i_version++;
3104         clear_nlink(inode);
3105         /* There's no need to set i_disksize: the fact that i_nlink is
3106          * zero will ensure that the right thing happens during any
3107          * recovery. */
3108         inode->i_size = 0;
3109         ext4_orphan_add(handle, inode);
3110         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
3111         ext4_mark_inode_dirty(handle, inode);
3112         ext4_dec_count(handle, dir);
3113         ext4_update_dx_flag(dir);
3114         ext4_mark_inode_dirty(handle, dir);
3115
3116 end_rmdir:
3117         brelse(bh);
3118         if (handle)
3119                 ext4_journal_stop(handle);
3120         return retval;
3121 }
3122
3123 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3124 {
3125         int retval;
3126         struct inode *inode;
3127         struct buffer_head *bh;
3128         struct ext4_dir_entry_2 *de;
3129         handle_t *handle = NULL;
3130
3131         trace_ext4_unlink_enter(dir, dentry);
3132         /* Initialize quotas before so that eventual writes go
3133          * in separate transaction */
3134         dquot_initialize(dir);
3135         dquot_initialize(dentry->d_inode);
3136
3137         retval = -ENOENT;
3138         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3139         if (IS_ERR(bh))
3140                 return PTR_ERR(bh);
3141         if (!bh)
3142                 goto end_unlink;
3143
3144         inode = dentry->d_inode;
3145
3146         retval = -EIO;
3147         if (le32_to_cpu(de->inode) != inode->i_ino)
3148                 goto end_unlink;
3149
3150         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3151                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3152         if (IS_ERR(handle)) {
3153                 retval = PTR_ERR(handle);
3154                 handle = NULL;
3155                 goto end_unlink;
3156         }
3157
3158         if (IS_DIRSYNC(dir))
3159                 ext4_handle_sync(handle);
3160
3161         if (!inode->i_nlink) {
3162                 ext4_warning(inode->i_sb,
3163                              "Deleting nonexistent file (%lu), %d",
3164                              inode->i_ino, inode->i_nlink);
3165                 set_nlink(inode, 1);
3166         }
3167         retval = ext4_delete_entry(handle, dir, de, bh);
3168         if (retval)
3169                 goto end_unlink;
3170         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3171         ext4_update_dx_flag(dir);
3172         ext4_mark_inode_dirty(handle, dir);
3173         drop_nlink(inode);
3174         if (!inode->i_nlink)
3175                 ext4_orphan_add(handle, inode);
3176         inode->i_ctime = ext4_current_time(inode);
3177         ext4_mark_inode_dirty(handle, inode);
3178
3179 end_unlink:
3180         brelse(bh);
3181         if (handle)
3182                 ext4_journal_stop(handle);
3183         trace_ext4_unlink_exit(dentry, retval);
3184         return retval;
3185 }
3186
3187 static int ext4_symlink(struct inode *dir,
3188                         struct dentry *dentry, const char *symname)
3189 {
3190         handle_t *handle;
3191         struct inode *inode;
3192         int err, len = strlen(symname);
3193         int credits;
3194         bool encryption_required;
3195         struct ext4_str disk_link;
3196         struct ext4_encrypted_symlink_data *sd = NULL;
3197
3198         disk_link.len = len + 1;
3199         disk_link.name = (char *) symname;
3200
3201         encryption_required = (ext4_encrypted_inode(dir) ||
3202                                DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3203         if (encryption_required)
3204                 disk_link.len = encrypted_symlink_data_len(len) + 1;
3205         if (disk_link.len > dir->i_sb->s_blocksize)
3206                 return -ENAMETOOLONG;
3207
3208         dquot_initialize(dir);
3209
3210         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3211                 /*
3212                  * For non-fast symlinks, we just allocate inode and put it on
3213                  * orphan list in the first transaction => we need bitmap,
3214                  * group descriptor, sb, inode block, quota blocks, and
3215                  * possibly selinux xattr blocks.
3216                  */
3217                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3218                           EXT4_XATTR_TRANS_BLOCKS;
3219         } else {
3220                 /*
3221                  * Fast symlink. We have to add entry to directory
3222                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3223                  * allocate new inode (bitmap, group descriptor, inode block,
3224                  * quota blocks, sb is already counted in previous macros).
3225                  */
3226                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3227                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3228         }
3229
3230         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3231                                             &dentry->d_name, 0, NULL,
3232                                             EXT4_HT_DIR, credits);
3233         handle = ext4_journal_current_handle();
3234         if (IS_ERR(inode)) {
3235                 if (handle)
3236                         ext4_journal_stop(handle);
3237                 return PTR_ERR(inode);
3238         }
3239
3240         if (encryption_required) {
3241                 struct ext4_fname_crypto_ctx *ctx = NULL;
3242                 struct qstr istr;
3243                 struct ext4_str ostr;
3244
3245                 sd = kzalloc(disk_link.len, GFP_NOFS);
3246                 if (!sd) {
3247                         err = -ENOMEM;
3248                         goto err_drop_inode;
3249                 }
3250                 err = ext4_inherit_context(dir, inode);
3251                 if (err)
3252                         goto err_drop_inode;
3253                 ctx = ext4_get_fname_crypto_ctx(inode,
3254                                                 inode->i_sb->s_blocksize);
3255                 if (IS_ERR_OR_NULL(ctx)) {
3256                         /* We just set the policy, so ctx should not be NULL */
3257                         err = (ctx == NULL) ? -EIO : PTR_ERR(ctx);
3258                         goto err_drop_inode;
3259                 }
3260                 istr.name = (const unsigned char *) symname;
3261                 istr.len = len;
3262                 ostr.name = sd->encrypted_path;
3263                 err = ext4_fname_usr_to_disk(ctx, &istr, &ostr);
3264                 ext4_put_fname_crypto_ctx(&ctx);
3265                 if (err < 0)
3266                         goto err_drop_inode;
3267                 sd->len = cpu_to_le16(ostr.len);
3268                 disk_link.name = (char *) sd;
3269         }
3270
3271         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3272                 inode->i_op = &ext4_symlink_inode_operations;
3273                 ext4_set_aops(inode);
3274                 /*
3275                  * We cannot call page_symlink() with transaction started
3276                  * because it calls into ext4_write_begin() which can wait
3277                  * for transaction commit if we are running out of space
3278                  * and thus we deadlock. So we have to stop transaction now
3279                  * and restart it when symlink contents is written.
3280                  *
3281                  * To keep fs consistent in case of crash, we have to put inode
3282                  * to orphan list in the mean time.
3283                  */
3284                 drop_nlink(inode);
3285                 err = ext4_orphan_add(handle, inode);
3286                 ext4_journal_stop(handle);
3287                 handle = NULL;
3288                 if (err)
3289                         goto err_drop_inode;
3290                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3291                 if (err)
3292                         goto err_drop_inode;
3293                 /*
3294                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3295                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3296                  */
3297                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3298                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3299                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3300                 if (IS_ERR(handle)) {
3301                         err = PTR_ERR(handle);
3302                         handle = NULL;
3303                         goto err_drop_inode;
3304                 }
3305                 set_nlink(inode, 1);
3306                 err = ext4_orphan_del(handle, inode);
3307                 if (err)
3308                         goto err_drop_inode;
3309         } else {
3310                 /* clear the extent format for fast symlink */
3311                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3312                 inode->i_op = encryption_required ?
3313                         &ext4_symlink_inode_operations :
3314                         &ext4_fast_symlink_inode_operations;
3315                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3316                        disk_link.len);
3317                 inode->i_size = disk_link.len - 1;
3318         }
3319         EXT4_I(inode)->i_disksize = inode->i_size;
3320         err = ext4_add_nondir(handle, dentry, inode);
3321         if (!err && IS_DIRSYNC(dir))
3322                 ext4_handle_sync(handle);
3323
3324         if (handle)
3325                 ext4_journal_stop(handle);
3326         kfree(sd);
3327         return err;
3328 err_drop_inode:
3329         if (handle)
3330                 ext4_journal_stop(handle);
3331         kfree(sd);
3332         clear_nlink(inode);
3333         unlock_new_inode(inode);
3334         iput(inode);
3335         return err;
3336 }
3337
3338 static int ext4_link(struct dentry *old_dentry,
3339                      struct inode *dir, struct dentry *dentry)
3340 {
3341         handle_t *handle;
3342         struct inode *inode = old_dentry->d_inode;
3343         int err, retries = 0;
3344
3345         if (inode->i_nlink >= EXT4_LINK_MAX)
3346                 return -EMLINK;
3347         if (ext4_encrypted_inode(dir) &&
3348             !ext4_is_child_context_consistent_with_parent(dir, inode))
3349                 return -EPERM;
3350         dquot_initialize(dir);
3351
3352 retry:
3353         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3354                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3355                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3356         if (IS_ERR(handle))
3357                 return PTR_ERR(handle);
3358
3359         if (IS_DIRSYNC(dir))
3360                 ext4_handle_sync(handle);
3361
3362         inode->i_ctime = ext4_current_time(inode);
3363         ext4_inc_count(handle, inode);
3364         ihold(inode);
3365
3366         err = ext4_add_entry(handle, dentry, inode);
3367         if (!err) {
3368                 ext4_mark_inode_dirty(handle, inode);
3369                 /* this can happen only for tmpfile being
3370                  * linked the first time
3371                  */
3372                 if (inode->i_nlink == 1)
3373                         ext4_orphan_del(handle, inode);
3374                 d_instantiate(dentry, inode);
3375         } else {
3376                 drop_nlink(inode);
3377                 iput(inode);
3378         }
3379         ext4_journal_stop(handle);
3380         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3381                 goto retry;
3382         return err;
3383 }
3384
3385
3386 /*
3387  * Try to find buffer head where contains the parent block.
3388  * It should be the inode block if it is inlined or the 1st block
3389  * if it is a normal dir.
3390  */
3391 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3392                                         struct inode *inode,
3393                                         int *retval,
3394                                         struct ext4_dir_entry_2 **parent_de,
3395                                         int *inlined)
3396 {
3397         struct buffer_head *bh;
3398
3399         if (!ext4_has_inline_data(inode)) {
3400                 bh = ext4_read_dirblock(inode, 0, EITHER);
3401                 if (IS_ERR(bh)) {
3402                         *retval = PTR_ERR(bh);
3403                         return NULL;
3404                 }
3405                 *parent_de = ext4_next_entry(
3406                                         (struct ext4_dir_entry_2 *)bh->b_data,
3407                                         inode->i_sb->s_blocksize);
3408                 return bh;
3409         }
3410
3411         *inlined = 1;
3412         return ext4_get_first_inline_block(inode, parent_de, retval);
3413 }
3414
3415 struct ext4_renament {
3416         struct inode *dir;
3417         struct dentry *dentry;
3418         struct inode *inode;
3419         bool is_dir;
3420         int dir_nlink_delta;
3421
3422         /* entry for "dentry" */
3423         struct buffer_head *bh;
3424         struct ext4_dir_entry_2 *de;
3425         int inlined;
3426
3427         /* entry for ".." in inode if it's a directory */
3428         struct buffer_head *dir_bh;
3429         struct ext4_dir_entry_2 *parent_de;
3430         int dir_inlined;
3431 };
3432
3433 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3434 {
3435         int retval;
3436
3437         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3438                                               &retval, &ent->parent_de,
3439                                               &ent->dir_inlined);
3440         if (!ent->dir_bh)
3441                 return retval;
3442         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3443                 return -EIO;
3444         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3445         return ext4_journal_get_write_access(handle, ent->dir_bh);
3446 }
3447
3448 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3449                                   unsigned dir_ino)
3450 {
3451         int retval;
3452
3453         ent->parent_de->inode = cpu_to_le32(dir_ino);
3454         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3455         if (!ent->dir_inlined) {
3456                 if (is_dx(ent->inode)) {
3457                         retval = ext4_handle_dirty_dx_node(handle,
3458                                                            ent->inode,
3459                                                            ent->dir_bh);
3460                 } else {
3461                         retval = ext4_handle_dirty_dirent_node(handle,
3462                                                                ent->inode,
3463                                                                ent->dir_bh);
3464                 }
3465         } else {
3466                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3467         }
3468         if (retval) {
3469                 ext4_std_error(ent->dir->i_sb, retval);
3470                 return retval;
3471         }
3472         return 0;
3473 }
3474
3475 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3476                        unsigned ino, unsigned file_type)
3477 {
3478         int retval;
3479
3480         BUFFER_TRACE(ent->bh, "get write access");
3481         retval = ext4_journal_get_write_access(handle, ent->bh);
3482         if (retval)
3483                 return retval;
3484         ent->de->inode = cpu_to_le32(ino);
3485         if (EXT4_HAS_INCOMPAT_FEATURE(ent->dir->i_sb,
3486                                       EXT4_FEATURE_INCOMPAT_FILETYPE))
3487                 ent->de->file_type = file_type;
3488         ent->dir->i_version++;
3489         ent->dir->i_ctime = ent->dir->i_mtime =
3490                 ext4_current_time(ent->dir);
3491         ext4_mark_inode_dirty(handle, ent->dir);
3492         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3493         if (!ent->inlined) {
3494                 retval = ext4_handle_dirty_dirent_node(handle,
3495                                                        ent->dir, ent->bh);
3496                 if (unlikely(retval)) {
3497                         ext4_std_error(ent->dir->i_sb, retval);
3498                         return retval;
3499                 }
3500         }
3501         brelse(ent->bh);
3502         ent->bh = NULL;
3503
3504         return 0;
3505 }
3506
3507 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3508                                   const struct qstr *d_name)
3509 {
3510         int retval = -ENOENT;
3511         struct buffer_head *bh;
3512         struct ext4_dir_entry_2 *de;
3513
3514         bh = ext4_find_entry(dir, d_name, &de, NULL);
3515         if (IS_ERR(bh))
3516                 return PTR_ERR(bh);
3517         if (bh) {
3518                 retval = ext4_delete_entry(handle, dir, de, bh);
3519                 brelse(bh);
3520         }
3521         return retval;
3522 }
3523
3524 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3525                                int force_reread)
3526 {
3527         int retval;
3528         /*
3529          * ent->de could have moved from under us during htree split, so make
3530          * sure that we are deleting the right entry.  We might also be pointing
3531          * to a stale entry in the unused part of ent->bh so just checking inum
3532          * and the name isn't enough.
3533          */
3534         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3535             ent->de->name_len != ent->dentry->d_name.len ||
3536             strncmp(ent->de->name, ent->dentry->d_name.name,
3537                     ent->de->name_len) ||
3538             force_reread) {
3539                 retval = ext4_find_delete_entry(handle, ent->dir,
3540                                                 &ent->dentry->d_name);
3541         } else {
3542                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3543                 if (retval == -ENOENT) {
3544                         retval = ext4_find_delete_entry(handle, ent->dir,
3545                                                         &ent->dentry->d_name);
3546                 }
3547         }
3548
3549         if (retval) {
3550                 ext4_warning(ent->dir->i_sb,
3551                                 "Deleting old file (%lu), %d, error=%d",
3552                                 ent->dir->i_ino, ent->dir->i_nlink, retval);
3553         }
3554 }
3555
3556 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3557 {
3558         if (ent->dir_nlink_delta) {
3559                 if (ent->dir_nlink_delta == -1)
3560                         ext4_dec_count(handle, ent->dir);
3561                 else
3562                         ext4_inc_count(handle, ent->dir);
3563                 ext4_mark_inode_dirty(handle, ent->dir);
3564         }
3565 }
3566
3567 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3568                                               int credits, handle_t **h)
3569 {
3570         struct inode *wh;
3571         handle_t *handle;
3572         int retries = 0;
3573
3574         /*
3575          * for inode block, sb block, group summaries,
3576          * and inode bitmap
3577          */
3578         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3579                     EXT4_XATTR_TRANS_BLOCKS + 4);
3580 retry:
3581         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3582                                          &ent->dentry->d_name, 0, NULL,
3583                                          EXT4_HT_DIR, credits);
3584
3585         handle = ext4_journal_current_handle();
3586         if (IS_ERR(wh)) {
3587                 if (handle)
3588                         ext4_journal_stop(handle);
3589                 if (PTR_ERR(wh) == -ENOSPC &&
3590                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3591                         goto retry;
3592         } else {
3593                 *h = handle;
3594                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3595                 wh->i_op = &ext4_special_inode_operations;
3596         }
3597         return wh;
3598 }
3599
3600 /*
3601  * Anybody can rename anything with this: the permission checks are left to the
3602  * higher-level routines.
3603  *
3604  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3605  * while new_{dentry,inode) refers to the destination dentry/inode
3606  * This comes from rename(const char *oldpath, const char *newpath)
3607  */
3608 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3609                        struct inode *new_dir, struct dentry *new_dentry,
3610                        unsigned int flags)
3611 {
3612         handle_t *handle = NULL;
3613         struct ext4_renament old = {
3614                 .dir = old_dir,
3615                 .dentry = old_dentry,
3616                 .inode = old_dentry->d_inode,
3617         };
3618         struct ext4_renament new = {
3619                 .dir = new_dir,
3620                 .dentry = new_dentry,
3621                 .inode = new_dentry->d_inode,
3622         };
3623         int force_reread;
3624         int retval;
3625         struct inode *whiteout = NULL;
3626         int credits;
3627         u8 old_file_type;
3628
3629         dquot_initialize(old.dir);
3630         dquot_initialize(new.dir);
3631
3632         /* Initialize quotas before so that eventual writes go
3633          * in separate transaction */
3634         if (new.inode)
3635                 dquot_initialize(new.inode);
3636
3637         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3638         if (IS_ERR(old.bh))
3639                 return PTR_ERR(old.bh);
3640         /*
3641          *  Check for inode number is _not_ due to possible IO errors.
3642          *  We might rmdir the source, keep it as pwd of some process
3643          *  and merrily kill the link to whatever was created under the
3644          *  same name. Goodbye sticky bit ;-<
3645          */
3646         retval = -ENOENT;
3647         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3648                 goto end_rename;
3649
3650         if ((old.dir != new.dir) &&
3651             ext4_encrypted_inode(new.dir) &&
3652             !ext4_is_child_context_consistent_with_parent(new.dir,
3653                                                           old.inode)) {
3654                 retval = -EPERM;
3655                 goto end_rename;
3656         }
3657
3658         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3659                                  &new.de, &new.inlined);
3660         if (IS_ERR(new.bh)) {
3661                 retval = PTR_ERR(new.bh);
3662                 new.bh = NULL;
3663                 goto end_rename;
3664         }
3665         if (new.bh) {
3666                 if (!new.inode) {
3667                         brelse(new.bh);
3668                         new.bh = NULL;
3669                 }
3670         }
3671         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3672                 ext4_alloc_da_blocks(old.inode);
3673
3674         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3675                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3676         if (!(flags & RENAME_WHITEOUT)) {
3677                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3678                 if (IS_ERR(handle)) {
3679                         retval = PTR_ERR(handle);
3680                         handle = NULL;
3681                         goto end_rename;
3682                 }
3683         } else {
3684                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3685                 if (IS_ERR(whiteout)) {
3686                         retval = PTR_ERR(whiteout);
3687                         whiteout = NULL;
3688                         goto end_rename;
3689                 }
3690         }
3691
3692         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3693                 ext4_handle_sync(handle);
3694
3695         if (S_ISDIR(old.inode->i_mode)) {
3696                 if (new.inode) {
3697                         retval = -ENOTEMPTY;
3698                         if (!ext4_empty_dir(new.inode))
3699                                 goto end_rename;
3700                 } else {
3701                         retval = -EMLINK;
3702                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3703                                 goto end_rename;
3704                 }
3705                 retval = ext4_rename_dir_prepare(handle, &old);
3706                 if (retval)
3707                         goto end_rename;
3708         }
3709         /*
3710          * If we're renaming a file within an inline_data dir and adding or
3711          * setting the new dirent causes a conversion from inline_data to
3712          * extents/blockmap, we need to force the dirent delete code to
3713          * re-read the directory, or else we end up trying to delete a dirent
3714          * from what is now the extent tree root (or a block map).
3715          */
3716         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3717                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3718
3719         old_file_type = old.de->file_type;
3720         if (whiteout) {
3721                 /*
3722                  * Do this before adding a new entry, so the old entry is sure
3723                  * to be still pointing to the valid old entry.
3724                  */
3725                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3726                                      EXT4_FT_CHRDEV);
3727                 if (retval)
3728                         goto end_rename;
3729                 ext4_mark_inode_dirty(handle, whiteout);
3730         }
3731         if (!new.bh) {
3732                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3733                 if (retval)
3734                         goto end_rename;
3735         } else {
3736                 retval = ext4_setent(handle, &new,
3737                                      old.inode->i_ino, old_file_type);
3738                 if (retval)
3739                         goto end_rename;
3740         }
3741         if (force_reread)
3742                 force_reread = !ext4_test_inode_flag(new.dir,
3743                                                      EXT4_INODE_INLINE_DATA);
3744
3745         /*
3746          * Like most other Unix systems, set the ctime for inodes on a
3747          * rename.
3748          */
3749         old.inode->i_ctime = ext4_current_time(old.inode);
3750         ext4_mark_inode_dirty(handle, old.inode);
3751
3752         if (!whiteout) {
3753                 /*
3754                  * ok, that's it
3755                  */
3756                 ext4_rename_delete(handle, &old, force_reread);
3757         }
3758
3759         if (new.inode) {
3760                 ext4_dec_count(handle, new.inode);
3761                 new.inode->i_ctime = ext4_current_time(new.inode);
3762         }
3763         old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3764         ext4_update_dx_flag(old.dir);
3765         if (old.dir_bh) {
3766                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3767                 if (retval)
3768                         goto end_rename;
3769
3770                 ext4_dec_count(handle, old.dir);
3771                 if (new.inode) {
3772                         /* checked ext4_empty_dir above, can't have another
3773                          * parent, ext4_dec_count() won't work for many-linked
3774                          * dirs */
3775                         clear_nlink(new.inode);
3776                 } else {
3777                         ext4_inc_count(handle, new.dir);
3778                         ext4_update_dx_flag(new.dir);
3779                         ext4_mark_inode_dirty(handle, new.dir);
3780                 }
3781         }
3782         ext4_mark_inode_dirty(handle, old.dir);
3783         if (new.inode) {
3784                 ext4_mark_inode_dirty(handle, new.inode);
3785                 if (!new.inode->i_nlink)
3786                         ext4_orphan_add(handle, new.inode);
3787         }
3788         retval = 0;
3789
3790 end_rename:
3791         brelse(old.dir_bh);
3792         brelse(old.bh);
3793         brelse(new.bh);
3794         if (whiteout) {
3795                 if (retval)
3796                         drop_nlink(whiteout);
3797                 unlock_new_inode(whiteout);
3798                 iput(whiteout);
3799         }
3800         if (handle)
3801                 ext4_journal_stop(handle);
3802         return retval;
3803 }
3804
3805 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3806                              struct inode *new_dir, struct dentry *new_dentry)
3807 {
3808         handle_t *handle = NULL;
3809         struct ext4_renament old = {
3810                 .dir = old_dir,
3811                 .dentry = old_dentry,
3812                 .inode = old_dentry->d_inode,
3813         };
3814         struct ext4_renament new = {
3815                 .dir = new_dir,
3816                 .dentry = new_dentry,
3817                 .inode = new_dentry->d_inode,
3818         };
3819         u8 new_file_type;
3820         int retval;
3821
3822         dquot_initialize(old.dir);
3823         dquot_initialize(new.dir);
3824
3825         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3826                                  &old.de, &old.inlined);
3827         if (IS_ERR(old.bh))
3828                 return PTR_ERR(old.bh);
3829         /*
3830          *  Check for inode number is _not_ due to possible IO errors.
3831          *  We might rmdir the source, keep it as pwd of some process
3832          *  and merrily kill the link to whatever was created under the
3833          *  same name. Goodbye sticky bit ;-<
3834          */
3835         retval = -ENOENT;
3836         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3837                 goto end_rename;
3838
3839         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3840                                  &new.de, &new.inlined);
3841         if (IS_ERR(new.bh)) {
3842                 retval = PTR_ERR(new.bh);
3843                 new.bh = NULL;
3844                 goto end_rename;
3845         }
3846
3847         /* RENAME_EXCHANGE case: old *and* new must both exist */
3848         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3849                 goto end_rename;
3850
3851         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3852                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3853                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3854         if (IS_ERR(handle)) {
3855                 retval = PTR_ERR(handle);
3856                 handle = NULL;
3857                 goto end_rename;
3858         }
3859
3860         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3861                 ext4_handle_sync(handle);
3862
3863         if (S_ISDIR(old.inode->i_mode)) {
3864                 old.is_dir = true;
3865                 retval = ext4_rename_dir_prepare(handle, &old);
3866                 if (retval)
3867                         goto end_rename;
3868         }
3869         if (S_ISDIR(new.inode->i_mode)) {
3870                 new.is_dir = true;
3871                 retval = ext4_rename_dir_prepare(handle, &new);
3872                 if (retval)
3873                         goto end_rename;
3874         }
3875
3876         /*
3877          * Other than the special case of overwriting a directory, parents'
3878          * nlink only needs to be modified if this is a cross directory rename.
3879          */
3880         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3881                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3882                 new.dir_nlink_delta = -old.dir_nlink_delta;
3883                 retval = -EMLINK;
3884                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3885                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3886                         goto end_rename;
3887         }
3888
3889         new_file_type = new.de->file_type;
3890         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3891         if (retval)
3892                 goto end_rename;
3893
3894         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3895         if (retval)
3896                 goto end_rename;
3897
3898         /*
3899          * Like most other Unix systems, set the ctime for inodes on a
3900          * rename.
3901          */
3902         old.inode->i_ctime = ext4_current_time(old.inode);
3903         new.inode->i_ctime = ext4_current_time(new.inode);
3904         ext4_mark_inode_dirty(handle, old.inode);
3905         ext4_mark_inode_dirty(handle, new.inode);
3906
3907         if (old.dir_bh) {
3908                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3909                 if (retval)
3910                         goto end_rename;
3911         }
3912         if (new.dir_bh) {
3913                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3914                 if (retval)
3915                         goto end_rename;
3916         }
3917         ext4_update_dir_count(handle, &old);
3918         ext4_update_dir_count(handle, &new);
3919         retval = 0;
3920
3921 end_rename:
3922         brelse(old.dir_bh);
3923         brelse(new.dir_bh);
3924         brelse(old.bh);
3925         brelse(new.bh);
3926         if (handle)
3927                 ext4_journal_stop(handle);
3928         return retval;
3929 }
3930
3931 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3932                         struct inode *new_dir, struct dentry *new_dentry,
3933                         unsigned int flags)
3934 {
3935         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3936                 return -EINVAL;
3937
3938         if (flags & RENAME_EXCHANGE) {
3939                 return ext4_cross_rename(old_dir, old_dentry,
3940                                          new_dir, new_dentry);
3941         }
3942
3943         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3944 }
3945
3946 /*
3947  * directories can handle most operations...
3948  */
3949 const struct inode_operations ext4_dir_inode_operations = {
3950         .create         = ext4_create,
3951         .lookup         = ext4_lookup,
3952         .link           = ext4_link,
3953         .unlink         = ext4_unlink,
3954         .symlink        = ext4_symlink,
3955         .mkdir          = ext4_mkdir,
3956         .rmdir          = ext4_rmdir,
3957         .mknod          = ext4_mknod,
3958         .tmpfile        = ext4_tmpfile,
3959         .rename2        = ext4_rename2,
3960         .setattr        = ext4_setattr,
3961         .setxattr       = generic_setxattr,
3962         .getxattr       = generic_getxattr,
3963         .listxattr      = ext4_listxattr,
3964         .removexattr    = generic_removexattr,
3965         .get_acl        = ext4_get_acl,
3966         .set_acl        = ext4_set_acl,
3967         .fiemap         = ext4_fiemap,
3968 };
3969
3970 const struct inode_operations ext4_special_inode_operations = {
3971         .setattr        = ext4_setattr,
3972         .setxattr       = generic_setxattr,
3973         .getxattr       = generic_getxattr,
3974         .listxattr      = ext4_listxattr,
3975         .removexattr    = generic_removexattr,
3976         .get_acl        = ext4_get_acl,
3977         .set_acl        = ext4_set_acl,
3978 };