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, NULL, 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                                         ext4fs_dirhash(de->name, de->name_len,
 657                                                        &h);
 658                                         printk("%*.s:(E)%x.%u ", len, name,
 659                                                h.hash, (unsigned) ((char *) de
 660                                                                    - base));
 661                                         ext4_put_fname_crypto_ctx(&ctx);
 662                                         ext4_fname_crypto_free_buffer(
 663                                                 &fname_crypto_str);
 664                                 }
 665 #else
 666                                 int len = de->name_len;
 667                                 char *name = de->name;
 668                                 ext4fs_dirhash(de->name, de->name_len, &h);
 669                                 printk("%*.s:%x.%u ", len, name, h.hash,
 670                                        (unsigned) ((char *) de - base));
 671 #endif
 672                         }
 673                         space += EXT4_DIR_REC_LEN(de->name_len);
 674                         names++;
 675                 }
 676                 de = ext4_next_entry(de, size);
 677         }
 678         printk("(%i)\n", names);
 679         return (struct stats) { names, space, 1 };
 680 }
 681
 682 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 683                              struct dx_entry *entries, int levels)
 684 {
 685         unsigned blocksize = dir->i_sb->s_blocksize;
 686         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 687         unsigned bcount = 0;
 688         struct buffer_head *bh;
 689         printk("%i indexed blocks...\n", count);
 690         for (i = 0; i < count; i++, entries++)
 691         {
 692                 ext4_lblk_t block = dx_get_block(entries);
 693                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 694                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 695                 struct stats stats;
 696                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 697                 bh = ext4_bread(NULL,dir, block, 0);
 698                 if (!bh || IS_ERR(bh))
 699                         continue;
 700                 stats = levels?
 701                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 702                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 703                         bh->b_data, blocksize, 0);
 704                 names += stats.names;
 705                 space += stats.space;
 706                 bcount += stats.bcount;
 707                 brelse(bh);
 708         }
 709         if (bcount)
 710                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 711                        levels ? "" : "   ", names, space/bcount,
 712                        (space/bcount)*100/blocksize);
 713         return (struct stats) { names, space, bcount};
 714 }
 715 #endif /* DX_DEBUG */
 716
 717 /*
 718  * Probe for a directory leaf block to search.
 719  *
 720  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 721  * error in the directory index, and the caller should fall back to
 722  * searching the directory normally.  The callers of dx_probe **MUST**
 723  * check for this error code, and make sure it never gets reflected
 724  * back to userspace.
 725  */
 726 static struct dx_frame *
 727 dx_probe(const struct qstr *d_name, struct inode *dir,
 728          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 729 {
 730         unsigned count, indirect;
 731         struct dx_entry *at, *entries, *p, *q, *m;
 732         struct dx_root *root;
 733         struct dx_frame *frame = frame_in;
 734         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 735         u32 hash;
 736
 737         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 738         if (IS_ERR(frame->bh))
 739                 return (struct dx_frame *) frame->bh;
 740
 741         root = (struct dx_root *) frame->bh->b_data;
 742         if (root->info.hash_version != DX_HASH_TEA &&
 743             root->info.hash_version != DX_HASH_HALF_MD4 &&
 744             root->info.hash_version != DX_HASH_LEGACY) {
 745                 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
 746                              root->info.hash_version);
 747                 goto fail;
 748         }
 749         hinfo->hash_version = root->info.hash_version;
 750         if (hinfo->hash_version <= DX_HASH_TEA)
 751                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 752         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 753 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 754         if (d_name) {
 755                 struct ext4_fname_crypto_ctx *ctx = NULL;
 756                 int res;
 757
 758                 /* Check if the directory is encrypted */
 759                 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
 760                 if (IS_ERR(ctx)) {
 761                         ret_err = ERR_PTR(PTR_ERR(ctx));
 762                         goto fail;
 763                 }
 764                 res = ext4_fname_usr_to_hash(ctx, d_name, hinfo);
 765                 if (res < 0) {
 766                         ret_err = ERR_PTR(res);
 767                         goto fail;
 768                 }
 769                 ext4_put_fname_crypto_ctx(&ctx);
 770         }
 771 #else
 772         if (d_name)
 773                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 774 #endif
 775         hash = hinfo->hash;
 776
 777         if (root->info.unused_flags & 1) {
 778                 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
 779                              root->info.unused_flags);
 780                 goto fail;
 781         }
 782
 783         if ((indirect = root->info.indirect_levels) > 1) {
 784                 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 785                              root->info.indirect_levels);
 786                 goto fail;
 787         }
 788
 789         entries = (struct dx_entry *) (((char *)&root->info) +
 790                                        root->info.info_length);
 791
 792         if (dx_get_limit(entries) != dx_root_limit(dir,
 793                                                    root->info.info_length)) {
 794                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 795                 goto fail;
 796         }
 797
 798         dxtrace(printk("Look up %x", hash));
 799         while (1) {
 800                 count = dx_get_count(entries);
 801                 if (!count || count > dx_get_limit(entries)) {
 802                         ext4_warning(dir->i_sb,
 803                                      "dx entry: no count or count > limit");
 804                         goto fail;
 805                 }
 806
 807                 p = entries + 1;
 808                 q = entries + count - 1;
 809                 while (p <= q) {
 810                         m = p + (q - p)/2;
 811                         dxtrace(printk("."));
 812                         if (dx_get_hash(m) > hash)
 813                                 q = m - 1;
 814                         else
 815                                 p = m + 1;
 816                 }
 817
 818                 if (0) { // linear search cross check
 819                         unsigned n = count - 1;
 820                         at = entries;
 821                         while (n--)
 822                         {
 823                                 dxtrace(printk(","));
 824                                 if (dx_get_hash(++at) > hash)
 825                                 {
 826                                         at--;
 827                                         break;
 828                                 }
 829                         }
 830                         assert (at == p - 1);
 831                 }
 832
 833                 at = p - 1;
 834                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 835                 frame->entries = entries;
 836                 frame->at = at;
 837                 if (!indirect--)
 838                         return frame;
 839                 frame++;
 840                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 841                 if (IS_ERR(frame->bh)) {
 842                         ret_err = (struct dx_frame *) frame->bh;
 843                         frame->bh = NULL;
 844                         goto fail;
 845                 }
 846                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 847
 848                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 849                         ext4_warning(dir->i_sb,
 850                                      "dx entry: limit != node limit");
 851                         goto fail;
 852                 }
 853         }
 854 fail:
 855         while (frame >= frame_in) {
 856                 brelse(frame->bh);
 857                 frame--;
 858         }
 859
 860         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 861                 ext4_warning(dir->i_sb,
 862                              "Corrupt dir inode %lu, running e2fsck is "
 863                              "recommended.", dir->i_ino);
 864         return ret_err;
 865 }
 866
 867 static void dx_release (struct dx_frame *frames)
 868 {
 869         if (frames[0].bh == NULL)
 870                 return;
 871
 872         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 873                 brelse(frames[1].bh);
 874         brelse(frames[0].bh);
 875 }
 876
 877 /*
 878  * This function increments the frame pointer to search the next leaf
 879  * block, and reads in the necessary intervening nodes if the search
 880  * should be necessary.  Whether or not the search is necessary is
 881  * controlled by the hash parameter.  If the hash value is even, then
 882  * the search is only continued if the next block starts with that
 883  * hash value.  This is used if we are searching for a specific file.
 884  *
 885  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 886  *
 887  * This function returns 1 if the caller should continue to search,
 888  * or 0 if it should not.  If there is an error reading one of the
 889  * index blocks, it will a negative error code.
 890  *
 891  * If start_hash is non-null, it will be filled in with the starting
 892  * hash of the next page.
 893  */
 894 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 895                                  struct dx_frame *frame,
 896                                  struct dx_frame *frames,
 897                                  __u32 *start_hash)
 898 {
 899         struct dx_frame *p;
 900         struct buffer_head *bh;
 901         int num_frames = 0;
 902         __u32 bhash;
 903
 904         p = frame;
 905         /*
 906          * Find the next leaf page by incrementing the frame pointer.
 907          * If we run out of entries in the interior node, loop around and
 908          * increment pointer in the parent node.  When we break out of
 909          * this loop, num_frames indicates the number of interior
 910          * nodes need to be read.
 911          */
 912         while (1) {
 913                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 914                         break;
 915                 if (p == frames)
 916                         return 0;
 917                 num_frames++;
 918                 p--;
 919         }
 920
 921         /*
 922          * If the hash is 1, then continue only if the next page has a
 923          * continuation hash of any value.  This is used for readdir
 924          * handling.  Otherwise, check to see if the hash matches the
 925          * desired contiuation hash.  If it doesn't, return since
 926          * there's no point to read in the successive index pages.
 927          */
 928         bhash = dx_get_hash(p->at);
 929         if (start_hash)
 930                 *start_hash = bhash;
 931         if ((hash & 1) == 0) {
 932                 if ((bhash & ~1) != hash)
 933                         return 0;
 934         }
 935         /*
 936          * If the hash is HASH_NB_ALWAYS, we always go to the next
 937          * block so no check is necessary
 938          */
 939         while (num_frames--) {
 940                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 941                 if (IS_ERR(bh))
 942                         return PTR_ERR(bh);
 943                 p++;
 944                 brelse(p->bh);
 945                 p->bh = bh;
 946                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 947         }
 948         return 1;
 949 }
 950
 951
 952 /*
 953  * This function fills a red-black tree with information from a
 954  * directory block.  It returns the number directory entries loaded
 955  * into the tree.  If there is an error it is returned in err.
 956  */
 957 static int htree_dirblock_to_tree(struct file *dir_file,
 958                                   struct inode *dir, ext4_lblk_t block,
 959                                   struct dx_hash_info *hinfo,
 960                                   __u32 start_hash, __u32 start_minor_hash)
 961 {
 962         struct buffer_head *bh;
 963         struct ext4_dir_entry_2 *de, *top;
 964         int err = 0, count = 0;
 965         struct ext4_fname_crypto_ctx *ctx = NULL;
 966         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
 967
 968         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 969                                                         (unsigned long)block));
 970         bh = ext4_read_dirblock(dir, block, DIRENT);
 971         if (IS_ERR(bh))
 972                 return PTR_ERR(bh);
 973
 974         de = (struct ext4_dir_entry_2 *) bh->b_data;
 975         top = (struct ext4_dir_entry_2 *) ((char *) de +
 976                                            dir->i_sb->s_blocksize -
 977                                            EXT4_DIR_REC_LEN(0));
 978 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 979         /* Check if the directory is encrypted */
 980         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
 981         if (IS_ERR(ctx)) {
 982                 err = PTR_ERR(ctx);
 983                 brelse(bh);
 984                 return err;
 985         }
 986         if (ctx != NULL) {
 987                 err = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
 988                                                      &fname_crypto_str);
 989                 if (err < 0) {
 990                         ext4_put_fname_crypto_ctx(&ctx);
 991                         brelse(bh);
 992                         return err;
 993                 }
 994         }
 995 #endif
 996         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 997                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 998                                 bh->b_data, bh->b_size,
 999                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1000                                          + ((char *)de - bh->b_data))) {
1001                         /* silently ignore the rest of the block */
1002                         break;
1003                 }
1004                 ext4fs_dirhash(de->name, de->name_len, hinfo);
1005                 if ((hinfo->hash < start_hash) ||
1006                     ((hinfo->hash == start_hash) &&
1007                      (hinfo->minor_hash < start_minor_hash)))
1008                         continue;
1009                 if (de->inode == 0)
1010                         continue;
1011                 if (ctx == NULL) {
1012                         /* Directory is not encrypted */
1013                         tmp_str.name = de->name;
1014                         tmp_str.len = de->name_len;
1015                         err = ext4_htree_store_dirent(dir_file,
1016                                    hinfo->hash, hinfo->minor_hash, de,
1017                                    &tmp_str);
1018                 } else {
1019                         /* Directory is encrypted */
1020                         err = ext4_fname_disk_to_usr(ctx, hinfo, de,
1021                                                      &fname_crypto_str);
1022                         if (err < 0) {
1023                                 count = err;
1024                                 goto errout;
1025                         }
1026                         err = ext4_htree_store_dirent(dir_file,
1027                                    hinfo->hash, hinfo->minor_hash, de,
1028                                         &fname_crypto_str);
1029                 }
1030                 if (err != 0) {
1031                         count = err;
1032                         goto errout;
1033                 }
1034                 count++;
1035         }
1036 errout:
1037         brelse(bh);
1038 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1039         ext4_put_fname_crypto_ctx(&ctx);
1040         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1041 #endif
1042         return count;
1043 }
1044
1045
1046 /*
1047  * This function fills a red-black tree with information from a
1048  * directory.  We start scanning the directory in hash order, starting
1049  * at start_hash and start_minor_hash.
1050  *
1051  * This function returns the number of entries inserted into the tree,
1052  * or a negative error code.
1053  */
1054 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1055                          __u32 start_minor_hash, __u32 *next_hash)
1056 {
1057         struct dx_hash_info hinfo;
1058         struct ext4_dir_entry_2 *de;
1059         struct dx_frame frames[2], *frame;
1060         struct inode *dir;
1061         ext4_lblk_t block;
1062         int count = 0;
1063         int ret, err;
1064         __u32 hashval;
1065         struct ext4_str tmp_str;
1066
1067         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1068                        start_hash, start_minor_hash));
1069         dir = file_inode(dir_file);
1070         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1071                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1072                 if (hinfo.hash_version <= DX_HASH_TEA)
1073                         hinfo.hash_version +=
1074                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1075                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1076                 if (ext4_has_inline_data(dir)) {
1077                         int has_inline_data = 1;
1078                         count = htree_inlinedir_to_tree(dir_file, dir, 0,
1079                                                         &hinfo, start_hash,
1080                                                         start_minor_hash,
1081                                                         &has_inline_data);
1082                         if (has_inline_data) {
1083                                 *next_hash = ~0;
1084                                 return count;
1085                         }
1086                 }
1087                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1088                                                start_hash, start_minor_hash);
1089                 *next_hash = ~0;
1090                 return count;
1091         }
1092         hinfo.hash = start_hash;
1093         hinfo.minor_hash = 0;
1094         frame = dx_probe(NULL, dir, &hinfo, frames);
1095         if (IS_ERR(frame))
1096                 return PTR_ERR(frame);
1097
1098         /* Add '.' and '..' from the htree header */
1099         if (!start_hash && !start_minor_hash) {
1100                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1101                 tmp_str.name = de->name;
1102                 tmp_str.len = de->name_len;
1103                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1104                                               de, &tmp_str);
1105                 if (err != 0)
1106                         goto errout;
1107                 count++;
1108         }
1109         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1110                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1111                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1112                 tmp_str.name = de->name;
1113                 tmp_str.len = de->name_len;
1114                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1115                                               de, &tmp_str);
1116                 if (err != 0)
1117                         goto errout;
1118                 count++;
1119         }
1120
1121         while (1) {
1122                 block = dx_get_block(frame->at);
1123                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1124                                              start_hash, start_minor_hash);
1125                 if (ret < 0) {
1126                         err = ret;
1127                         goto errout;
1128                 }
1129                 count += ret;
1130                 hashval = ~0;
1131                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1132                                             frame, frames, &hashval);
1133                 *next_hash = hashval;
1134                 if (ret < 0) {
1135                         err = ret;
1136                         goto errout;
1137                 }
1138                 /*
1139                  * Stop if:  (a) there are no more entries, or
1140                  * (b) we have inserted at least one entry and the
1141                  * next hash value is not a continuation
1142                  */
1143                 if ((ret == 0) ||
1144                     (count && ((hashval & 1) == 0)))
1145                         break;
1146         }
1147         dx_release(frames);
1148         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1149                        "next hash: %x\n", count, *next_hash));
1150         return count;
1151 errout:
1152         dx_release(frames);
1153         return (err);
1154 }
1155
1156 static inline int search_dirblock(struct buffer_head *bh,
1157                                   struct inode *dir,
1158                                   const struct qstr *d_name,
1159                                   unsigned int offset,
1160                                   struct ext4_dir_entry_2 **res_dir)
1161 {
1162         return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1163                           d_name, offset, res_dir);
1164 }
1165
1166 /*
1167  * Directory block splitting, compacting
1168  */
1169
1170 /*
1171  * Create map of hash values, offsets, and sizes, stored at end of block.
1172  * Returns number of entries mapped.
1173  */
1174 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1175                        unsigned blocksize, struct dx_hash_info *hinfo,
1176                        struct dx_map_entry *map_tail)
1177 {
1178         int count = 0;
1179         char *base = (char *) de;
1180         struct dx_hash_info h = *hinfo;
1181
1182         while ((char *) de < base + blocksize) {
1183                 if (de->name_len && de->inode) {
1184                         ext4fs_dirhash(de->name, de->name_len, &h);
1185                         map_tail--;
1186                         map_tail->hash = h.hash;
1187                         map_tail->offs = ((char *) de - base)>>2;
1188                         map_tail->size = le16_to_cpu(de->rec_len);
1189                         count++;
1190                         cond_resched();
1191                 }
1192                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1193                 de = ext4_next_entry(de, blocksize);
1194         }
1195         return count;
1196 }
1197
1198 /* Sort map by hash value */
1199 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1200 {
1201         struct dx_map_entry *p, *q, *top = map + count - 1;
1202         int more;
1203         /* Combsort until bubble sort doesn't suck */
1204         while (count > 2) {
1205                 count = count*10/13;
1206                 if (count - 9 < 2) /* 9, 10 -> 11 */
1207                         count = 11;
1208                 for (p = top, q = p - count; q >= map; p--, q--)
1209                         if (p->hash < q->hash)
1210                                 swap(*p, *q);
1211         }
1212         /* Garden variety bubble sort */
1213         do {
1214                 more = 0;
1215                 q = top;
1216                 while (q-- > map) {
1217                         if (q[1].hash >= q[0].hash)
1218                                 continue;
1219                         swap(*(q+1), *q);
1220                         more = 1;
1221                 }
1222         } while(more);
1223 }
1224
1225 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1226 {
1227         struct dx_entry *entries = frame->entries;
1228         struct dx_entry *old = frame->at, *new = old + 1;
1229         int count = dx_get_count(entries);
1230
1231         assert(count < dx_get_limit(entries));
1232         assert(old < entries + count);
1233         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1234         dx_set_hash(new, hash);
1235         dx_set_block(new, block);
1236         dx_set_count(entries, count + 1);
1237 }
1238
1239 /*
1240  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1241  *
1242  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1243  * `de != NULL' is guaranteed by caller.
1244  */
1245 static inline int ext4_match(struct ext4_fname_crypto_ctx *ctx,
1246                              struct ext4_str *fname_crypto_str,
1247                              int len, const char * const name,
1248                              struct ext4_dir_entry_2 *de)
1249 {
1250         int res;
1251
1252         if (!de->inode)
1253                 return 0;
1254
1255 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1256         if (ctx)
1257                 return ext4_fname_match(ctx, fname_crypto_str, len, name, de);
1258 #endif
1259         if (len != de->name_len)
1260                 return 0;
1261         res = memcmp(name, de->name, len);
1262         return (res == 0) ? 1 : 0;
1263 }
1264
1265 /*
1266  * Returns 0 if not found, -1 on failure, and 1 on success
1267  */
1268 int search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1269                struct inode *dir, const struct qstr *d_name,
1270                unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1271 {
1272         struct ext4_dir_entry_2 * de;
1273         char * dlimit;
1274         int de_len;
1275         const char *name = d_name->name;
1276         int namelen = d_name->len;
1277         struct ext4_fname_crypto_ctx *ctx = NULL;
1278         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1279         int res;
1280
1281         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1282         if (IS_ERR(ctx))
1283                 return -1;
1284
1285         de = (struct ext4_dir_entry_2 *)search_buf;
1286         dlimit = search_buf + buf_size;
1287         while ((char *) de < dlimit) {
1288                 /* this code is executed quadratically often */
1289                 /* do minimal checking `by hand' */
1290                 if ((char *) de + de->name_len <= dlimit) {
1291                         res = ext4_match(ctx, &fname_crypto_str, namelen,
1292                                          name, de);
1293                         if (res < 0) {
1294                                 res = -1;
1295                                 goto return_result;
1296                         }
1297                         if (res > 0) {
1298                                 /* found a match - just to be sure, do
1299                                  * a full check */
1300                                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1301                                                 bh->b_data,
1302                                                  bh->b_size, offset)) {
1303                                         res = -1;
1304                                         goto return_result;
1305                                 }
1306                                 *res_dir = de;
1307                                 res = 1;
1308                                 goto return_result;
1309                         }
1310
1311                 }
1312                 /* prevent looping on a bad block */
1313                 de_len = ext4_rec_len_from_disk(de->rec_len,
1314                                                 dir->i_sb->s_blocksize);
1315                 if (de_len <= 0) {
1316                         res = -1;
1317                         goto return_result;
1318                 }
1319                 offset += de_len;
1320                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1321         }
1322
1323         res = 0;
1324 return_result:
1325         ext4_put_fname_crypto_ctx(&ctx);
1326         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1327         return res;
1328 }
1329
1330 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1331                                struct ext4_dir_entry *de)
1332 {
1333         struct super_block *sb = dir->i_sb;
1334
1335         if (!is_dx(dir))
1336                 return 0;
1337         if (block == 0)
1338                 return 1;
1339         if (de->inode == 0 &&
1340             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1341                         sb->s_blocksize)
1342                 return 1;
1343         return 0;
1344 }
1345
1346 /*
1347  *      ext4_find_entry()
1348  *
1349  * finds an entry in the specified directory with the wanted name. It
1350  * returns the cache buffer in which the entry was found, and the entry
1351  * itself (as a parameter - res_dir). It does NOT read the inode of the
1352  * entry - you'll have to do that yourself if you want to.
1353  *
1354  * The returned buffer_head has ->b_count elevated.  The caller is expected
1355  * to brelse() it when appropriate.
1356  */
1357 static struct buffer_head * ext4_find_entry (struct inode *dir,
1358                                         const struct qstr *d_name,
1359                                         struct ext4_dir_entry_2 **res_dir,
1360                                         int *inlined)
1361 {
1362         struct super_block *sb;
1363         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1364         struct buffer_head *bh, *ret = NULL;
1365         ext4_lblk_t start, block, b;
1366         const u8 *name = d_name->name;
1367         int ra_max = 0;         /* Number of bh's in the readahead
1368                                    buffer, bh_use[] */
1369         int ra_ptr = 0;         /* Current index into readahead
1370                                    buffer */
1371         int num = 0;
1372         ext4_lblk_t  nblocks;
1373         int i, namelen;
1374
1375         *res_dir = NULL;
1376         sb = dir->i_sb;
1377         namelen = d_name->len;
1378         if (namelen > EXT4_NAME_LEN)
1379                 return NULL;
1380
1381         if (ext4_has_inline_data(dir)) {
1382                 int has_inline_data = 1;
1383                 ret = ext4_find_inline_entry(dir, d_name, res_dir,
1384                                              &has_inline_data);
1385                 if (has_inline_data) {
1386                         if (inlined)
1387                                 *inlined = 1;
1388                         return ret;
1389                 }
1390         }
1391
1392         if ((namelen <= 2) && (name[0] == '.') &&
1393             (name[1] == '.' || name[1] == '\0')) {
1394                 /*
1395                  * "." or ".." will only be in the first block
1396                  * NFS may look up ".."; "." should be handled by the VFS
1397                  */
1398                 block = start = 0;
1399                 nblocks = 1;
1400                 goto restart;
1401         }
1402         if (is_dx(dir)) {
1403                 bh = ext4_dx_find_entry(dir, d_name, res_dir);
1404                 /*
1405                  * On success, or if the error was file not found,
1406                  * return.  Otherwise, fall back to doing a search the
1407                  * old fashioned way.
1408                  */
1409                 if (!IS_ERR(bh) || PTR_ERR(bh) != ERR_BAD_DX_DIR)
1410                         return bh;
1411                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1412                                "falling back\n"));
1413         }
1414         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1415         start = EXT4_I(dir)->i_dir_start_lookup;
1416         if (start >= nblocks)
1417                 start = 0;
1418         block = start;
1419 restart:
1420         do {
1421                 /*
1422                  * We deal with the read-ahead logic here.
1423                  */
1424                 if (ra_ptr >= ra_max) {
1425                         /* Refill the readahead buffer */
1426                         ra_ptr = 0;
1427                         b = block;
1428                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1429                                 /*
1430                                  * Terminate if we reach the end of the
1431                                  * directory and must wrap, or if our
1432                                  * search has finished at this block.
1433                                  */
1434                                 if (b >= nblocks || (num && block == start)) {
1435                                         bh_use[ra_max] = NULL;
1436                                         break;
1437                                 }
1438                                 num++;
1439                                 bh = ext4_getblk(NULL, dir, b++, 0);
1440                                 if (unlikely(IS_ERR(bh))) {
1441                                         if (ra_max == 0)
1442                                                 return bh;
1443                                         break;
1444                                 }
1445                                 bh_use[ra_max] = bh;
1446                                 if (bh)
1447                                         ll_rw_block(READ | REQ_META | REQ_PRIO,
1448                                                     1, &bh);
1449                         }
1450                 }
1451                 if ((bh = bh_use[ra_ptr++]) == NULL)
1452                         goto next;
1453                 wait_on_buffer(bh);
1454                 if (!buffer_uptodate(bh)) {
1455                         /* read error, skip block & hope for the best */
1456                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1457                                          (unsigned long) block);
1458                         brelse(bh);
1459                         goto next;
1460                 }
1461                 if (!buffer_verified(bh) &&
1462                     !is_dx_internal_node(dir, block,
1463                                          (struct ext4_dir_entry *)bh->b_data) &&
1464                     !ext4_dirent_csum_verify(dir,
1465                                 (struct ext4_dir_entry *)bh->b_data)) {
1466                         EXT4_ERROR_INODE(dir, "checksumming directory "
1467                                          "block %lu", (unsigned long)block);
1468                         brelse(bh);
1469                         goto next;
1470                 }
1471                 set_buffer_verified(bh);
1472                 i = search_dirblock(bh, dir, d_name,
1473                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1474                 if (i == 1) {
1475                         EXT4_I(dir)->i_dir_start_lookup = block;
1476                         ret = bh;
1477                         goto cleanup_and_exit;
1478                 } else {
1479                         brelse(bh);
1480                         if (i < 0)
1481                                 goto cleanup_and_exit;
1482                 }
1483         next:
1484                 if (++block >= nblocks)
1485                         block = 0;
1486         } while (block != start);
1487
1488         /*
1489          * If the directory has grown while we were searching, then
1490          * search the last part of the directory before giving up.
1491          */
1492         block = nblocks;
1493         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1494         if (block < nblocks) {
1495                 start = 0;
1496                 goto restart;
1497         }
1498
1499 cleanup_and_exit:
1500         /* Clean up the read-ahead blocks */
1501         for (; ra_ptr < ra_max; ra_ptr++)
1502                 brelse(bh_use[ra_ptr]);
1503         return ret;
1504 }
1505
1506 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1507                        struct ext4_dir_entry_2 **res_dir)
1508 {
1509         struct super_block * sb = dir->i_sb;
1510         struct dx_hash_info     hinfo;
1511         struct dx_frame frames[2], *frame;
1512         struct buffer_head *bh;
1513         ext4_lblk_t block;
1514         int retval;
1515
1516 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1517         *res_dir = NULL;
1518 #endif
1519         frame = dx_probe(d_name, dir, &hinfo, frames);
1520         if (IS_ERR(frame))
1521                 return (struct buffer_head *) frame;
1522         do {
1523                 block = dx_get_block(frame->at);
1524                 bh = ext4_read_dirblock(dir, block, DIRENT);
1525                 if (IS_ERR(bh))
1526                         goto errout;
1527
1528                 retval = search_dirblock(bh, dir, d_name,
1529                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1530                                          res_dir);
1531                 if (retval == 1)
1532                         goto success;
1533                 brelse(bh);
1534                 if (retval == -1) {
1535                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1536                         goto errout;
1537                 }
1538
1539                 /* Check to see if we should continue to search */
1540                 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1541                                                frames, NULL);
1542                 if (retval < 0) {
1543                         ext4_warning(sb,
1544                              "error %d reading index page in directory #%lu",
1545                              retval, dir->i_ino);
1546                         bh = ERR_PTR(retval);
1547                         goto errout;
1548                 }
1549         } while (retval == 1);
1550
1551         bh = NULL;
1552 errout:
1553         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1554 success:
1555         dx_release(frames);
1556         return bh;
1557 }
1558
1559 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1560 {
1561         struct inode *inode;
1562         struct ext4_dir_entry_2 *de;
1563         struct buffer_head *bh;
1564
1565         if (dentry->d_name.len > EXT4_NAME_LEN)
1566                 return ERR_PTR(-ENAMETOOLONG);
1567
1568         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1569         if (IS_ERR(bh))
1570                 return (struct dentry *) bh;
1571         inode = NULL;
1572         if (bh) {
1573                 __u32 ino = le32_to_cpu(de->inode);
1574                 brelse(bh);
1575                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1576                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1577                         return ERR_PTR(-EIO);
1578                 }
1579                 if (unlikely(ino == dir->i_ino)) {
1580                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1581                                          dentry);
1582                         return ERR_PTR(-EIO);
1583                 }
1584                 inode = ext4_iget_normal(dir->i_sb, ino);
1585                 if (inode == ERR_PTR(-ESTALE)) {
1586                         EXT4_ERROR_INODE(dir,
1587                                          "deleted inode referenced: %u",
1588                                          ino);
1589                         return ERR_PTR(-EIO);
1590                 }
1591                 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1592                     (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1593                      S_ISLNK(inode->i_mode)) &&
1594                     !ext4_is_child_context_consistent_with_parent(dir,
1595                                                                   inode)) {
1596                         iput(inode);
1597                         ext4_warning(inode->i_sb,
1598                                      "Inconsistent encryption contexts: %lu/%lu\n",
1599                                      (unsigned long) dir->i_ino,
1600                                      (unsigned long) inode->i_ino);
1601                         return ERR_PTR(-EPERM);
1602                 }
1603         }
1604         return d_splice_alias(inode, dentry);
1605 }
1606
1607
1608 struct dentry *ext4_get_parent(struct dentry *child)
1609 {
1610         __u32 ino;
1611         static const struct qstr dotdot = QSTR_INIT("..", 2);
1612         struct ext4_dir_entry_2 * de;
1613         struct buffer_head *bh;
1614
1615         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1616         if (IS_ERR(bh))
1617                 return (struct dentry *) bh;
1618         if (!bh)
1619                 return ERR_PTR(-ENOENT);
1620         ino = le32_to_cpu(de->inode);
1621         brelse(bh);
1622
1623         if (!ext4_valid_inum(d_inode(child)->i_sb, ino)) {
1624                 EXT4_ERROR_INODE(d_inode(child),
1625                                  "bad parent inode number: %u", ino);
1626                 return ERR_PTR(-EIO);
1627         }
1628
1629         return d_obtain_alias(ext4_iget_normal(d_inode(child)->i_sb, ino));
1630 }
1631
1632 /*
1633  * Move count entries from end of map between two memory locations.
1634  * Returns pointer to last entry moved.
1635  */
1636 static struct ext4_dir_entry_2 *
1637 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1638                 unsigned blocksize)
1639 {
1640         unsigned rec_len = 0;
1641
1642         while (count--) {
1643                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1644                                                 (from + (map->offs<<2));
1645                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1646                 memcpy (to, de, rec_len);
1647                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1648                                 ext4_rec_len_to_disk(rec_len, blocksize);
1649                 de->inode = 0;
1650                 map++;
1651                 to += rec_len;
1652         }
1653         return (struct ext4_dir_entry_2 *) (to - rec_len);
1654 }
1655
1656 /*
1657  * Compact each dir entry in the range to the minimal rec_len.
1658  * Returns pointer to last entry in range.
1659  */
1660 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1661 {
1662         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1663         unsigned rec_len = 0;
1664
1665         prev = to = de;
1666         while ((char*)de < base + blocksize) {
1667                 next = ext4_next_entry(de, blocksize);
1668                 if (de->inode && de->name_len) {
1669                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1670                         if (de > to)
1671                                 memmove(to, de, rec_len);
1672                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1673                         prev = to;
1674                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1675                 }
1676                 de = next;
1677         }
1678         return prev;
1679 }
1680
1681 /*
1682  * Split a full leaf block to make room for a new dir entry.
1683  * Allocate a new block, and move entries so that they are approx. equally full.
1684  * Returns pointer to de in block into which the new entry will be inserted.
1685  */
1686 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1687                         struct buffer_head **bh,struct dx_frame *frame,
1688                         struct dx_hash_info *hinfo)
1689 {
1690         unsigned blocksize = dir->i_sb->s_blocksize;
1691         unsigned count, continued;
1692         struct buffer_head *bh2;
1693         ext4_lblk_t newblock;
1694         u32 hash2;
1695         struct dx_map_entry *map;
1696         char *data1 = (*bh)->b_data, *data2;
1697         unsigned split, move, size;
1698         struct ext4_dir_entry_2 *de = NULL, *de2;
1699         struct ext4_dir_entry_tail *t;
1700         int     csum_size = 0;
1701         int     err = 0, i;
1702
1703         if (ext4_has_metadata_csum(dir->i_sb))
1704                 csum_size = sizeof(struct ext4_dir_entry_tail);
1705
1706         bh2 = ext4_append(handle, dir, &newblock);
1707         if (IS_ERR(bh2)) {
1708                 brelse(*bh);
1709                 *bh = NULL;
1710                 return (struct ext4_dir_entry_2 *) bh2;
1711         }
1712
1713         BUFFER_TRACE(*bh, "get_write_access");
1714         err = ext4_journal_get_write_access(handle, *bh);
1715         if (err)
1716                 goto journal_error;
1717
1718         BUFFER_TRACE(frame->bh, "get_write_access");
1719         err = ext4_journal_get_write_access(handle, frame->bh);
1720         if (err)
1721                 goto journal_error;
1722
1723         data2 = bh2->b_data;
1724
1725         /* create map in the end of data2 block */
1726         map = (struct dx_map_entry *) (data2 + blocksize);
1727         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1728                              blocksize, hinfo, map);
1729         map -= count;
1730         dx_sort_map(map, count);
1731         /* Split the existing block in the middle, size-wise */
1732         size = 0;
1733         move = 0;
1734         for (i = count-1; i >= 0; i--) {
1735                 /* is more than half of this entry in 2nd half of the block? */
1736                 if (size + map[i].size/2 > blocksize/2)
1737                         break;
1738                 size += map[i].size;
1739                 move++;
1740         }
1741         /* map index at which we will split */
1742         split = count - move;
1743         hash2 = map[split].hash;
1744         continued = hash2 == map[split - 1].hash;
1745         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1746                         (unsigned long)dx_get_block(frame->at),
1747                                         hash2, split, count-split));
1748
1749         /* Fancy dance to stay within two buffers */
1750         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1751                               blocksize);
1752         de = dx_pack_dirents(data1, blocksize);
1753         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1754                                            (char *) de,
1755                                            blocksize);
1756         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1757                                             (char *) de2,
1758                                             blocksize);
1759         if (csum_size) {
1760                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1761                 initialize_dirent_tail(t, blocksize);
1762
1763                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1764                 initialize_dirent_tail(t, blocksize);
1765         }
1766
1767         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1768                         blocksize, 1));
1769         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1770                         blocksize, 1));
1771
1772         /* Which block gets the new entry? */
1773         if (hinfo->hash >= hash2) {
1774                 swap(*bh, bh2);
1775                 de = de2;
1776         }
1777         dx_insert_block(frame, hash2 + continued, newblock);
1778         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1779         if (err)
1780                 goto journal_error;
1781         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1782         if (err)
1783                 goto journal_error;
1784         brelse(bh2);
1785         dxtrace(dx_show_index("frame", frame->entries));
1786         return de;
1787
1788 journal_error:
1789         brelse(*bh);
1790         brelse(bh2);
1791         *bh = NULL;
1792         ext4_std_error(dir->i_sb, err);
1793         return ERR_PTR(err);
1794 }
1795
1796 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1797                       struct buffer_head *bh,
1798                       void *buf, int buf_size,
1799                       const char *name, int namelen,
1800                       struct ext4_dir_entry_2 **dest_de)
1801 {
1802         struct ext4_dir_entry_2 *de;
1803         unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
1804         int nlen, rlen;
1805         unsigned int offset = 0;
1806         char *top;
1807         struct ext4_fname_crypto_ctx *ctx = NULL;
1808         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1809         int res;
1810
1811         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1812         if (IS_ERR(ctx))
1813                 return -1;
1814
1815         if (ctx != NULL) {
1816                 /* Calculate record length needed to store the entry */
1817                 res = ext4_fname_crypto_namelen_on_disk(ctx, namelen);
1818                 if (res < 0) {
1819                         ext4_put_fname_crypto_ctx(&ctx);
1820                         return res;
1821                 }
1822                 reclen = EXT4_DIR_REC_LEN(res);
1823         }
1824
1825         de = (struct ext4_dir_entry_2 *)buf;
1826         top = buf + buf_size - reclen;
1827         while ((char *) de <= top) {
1828                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1829                                          buf, buf_size, offset)) {
1830                         res = -EIO;
1831                         goto return_result;
1832                 }
1833                 /* Provide crypto context and crypto buffer to ext4 match */
1834                 res = ext4_match(ctx, &fname_crypto_str, namelen, name, de);
1835                 if (res < 0)
1836                         goto return_result;
1837                 if (res > 0) {
1838                         res = -EEXIST;
1839                         goto return_result;
1840                 }
1841                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1842                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1843                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1844                         break;
1845                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1846                 offset += rlen;
1847         }
1848
1849         if ((char *) de > top)
1850                 res = -ENOSPC;
1851         else {
1852                 *dest_de = de;
1853                 res = 0;
1854         }
1855 return_result:
1856         ext4_put_fname_crypto_ctx(&ctx);
1857         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1858         return res;
1859 }
1860
1861 int ext4_insert_dentry(struct inode *dir,
1862                        struct inode *inode,
1863                        struct ext4_dir_entry_2 *de,
1864                        int buf_size,
1865                        const struct qstr *iname,
1866                        const char *name, int namelen)
1867 {
1868
1869         int nlen, rlen;
1870         struct ext4_fname_crypto_ctx *ctx = NULL;
1871         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1872         struct ext4_str tmp_str;
1873         int res;
1874
1875         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1876         if (IS_ERR(ctx))
1877                 return -EIO;
1878         /* By default, the input name would be written to the disk */
1879         tmp_str.name = (unsigned char *)name;
1880         tmp_str.len = namelen;
1881         if (ctx != NULL) {
1882                 /* Directory is encrypted */
1883                 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
1884                                                      &fname_crypto_str);
1885                 if (res < 0) {
1886                         ext4_put_fname_crypto_ctx(&ctx);
1887                         return -ENOMEM;
1888                 }
1889                 res = ext4_fname_usr_to_disk(ctx, iname, &fname_crypto_str);
1890                 if (res < 0) {
1891                         ext4_put_fname_crypto_ctx(&ctx);
1892                         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1893                         return res;
1894                 }
1895                 tmp_str.name = fname_crypto_str.name;
1896                 tmp_str.len = fname_crypto_str.len;
1897         }
1898
1899         nlen = EXT4_DIR_REC_LEN(de->name_len);
1900         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1901         if (de->inode) {
1902                 struct ext4_dir_entry_2 *de1 =
1903                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1904                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1905                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1906                 de = de1;
1907         }
1908         de->file_type = EXT4_FT_UNKNOWN;
1909         de->inode = cpu_to_le32(inode->i_ino);
1910         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1911         de->name_len = tmp_str.len;
1912
1913         memcpy(de->name, tmp_str.name, tmp_str.len);
1914         ext4_put_fname_crypto_ctx(&ctx);
1915         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1916         return 0;
1917 }
1918
1919 /*
1920  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1921  * it points to a directory entry which is guaranteed to be large
1922  * enough for new directory entry.  If de is NULL, then
1923  * add_dirent_to_buf will attempt search the directory block for
1924  * space.  It will return -ENOSPC if no space is available, and -EIO
1925  * and -EEXIST if directory entry already exists.
1926  */
1927 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1928                              struct inode *inode, struct ext4_dir_entry_2 *de,
1929                              struct buffer_head *bh)
1930 {
1931         struct inode    *dir = d_inode(dentry->d_parent);
1932         const char      *name = dentry->d_name.name;
1933         int             namelen = dentry->d_name.len;
1934         unsigned int    blocksize = dir->i_sb->s_blocksize;
1935         int             csum_size = 0;
1936         int             err;
1937
1938         if (ext4_has_metadata_csum(inode->i_sb))
1939                 csum_size = sizeof(struct ext4_dir_entry_tail);
1940
1941         if (!de) {
1942                 err = ext4_find_dest_de(dir, inode,
1943                                         bh, bh->b_data, blocksize - csum_size,
1944                                         name, namelen, &de);
1945                 if (err)
1946                         return err;
1947         }
1948         BUFFER_TRACE(bh, "get_write_access");
1949         err = ext4_journal_get_write_access(handle, bh);
1950         if (err) {
1951                 ext4_std_error(dir->i_sb, err);
1952                 return err;
1953         }
1954
1955         /* By now the buffer is marked for journaling. Due to crypto operations,
1956          * the following function call may fail */
1957         err = ext4_insert_dentry(dir, inode, de, blocksize, &dentry->d_name,
1958                                  name, namelen);
1959         if (err < 0)
1960                 return err;
1961
1962         /*
1963          * XXX shouldn't update any times until successful
1964          * completion of syscall, but too many callers depend
1965          * on this.
1966          *
1967          * XXX similarly, too many callers depend on
1968          * ext4_new_inode() setting the times, but error
1969          * recovery deletes the inode, so the worst that can
1970          * happen is that the times are slightly out of date
1971          * and/or different from the directory change time.
1972          */
1973         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1974         ext4_update_dx_flag(dir);
1975         dir->i_version++;
1976         ext4_mark_inode_dirty(handle, dir);
1977         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1978         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1979         if (err)
1980                 ext4_std_error(dir->i_sb, err);
1981         return 0;
1982 }
1983
1984 /*
1985  * This converts a one block unindexed directory to a 3 block indexed
1986  * directory, and adds the dentry to the indexed directory.
1987  */
1988 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1989                             struct inode *inode, struct buffer_head *bh)
1990 {
1991         struct inode    *dir = d_inode(dentry->d_parent);
1992 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1993         struct ext4_fname_crypto_ctx *ctx = NULL;
1994         int res;
1995 #else
1996         const char      *name = dentry->d_name.name;
1997         int             namelen = dentry->d_name.len;
1998 #endif
1999         struct buffer_head *bh2;
2000         struct dx_root  *root;
2001         struct dx_frame frames[2], *frame;
2002         struct dx_entry *entries;
2003         struct ext4_dir_entry_2 *de, *de2;
2004         struct ext4_dir_entry_tail *t;
2005         char            *data1, *top;
2006         unsigned        len;
2007         int             retval;
2008         unsigned        blocksize;
2009         struct dx_hash_info hinfo;
2010         ext4_lblk_t  block;
2011         struct fake_dirent *fde;
2012         int csum_size = 0;
2013
2014 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2015         ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
2016         if (IS_ERR(ctx))
2017                 return PTR_ERR(ctx);
2018 #endif
2019
2020         if (ext4_has_metadata_csum(inode->i_sb))
2021                 csum_size = sizeof(struct ext4_dir_entry_tail);
2022
2023         blocksize =  dir->i_sb->s_blocksize;
2024         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2025         BUFFER_TRACE(bh, "get_write_access");
2026         retval = ext4_journal_get_write_access(handle, bh);
2027         if (retval) {
2028                 ext4_std_error(dir->i_sb, retval);
2029                 brelse(bh);
2030                 return retval;
2031         }
2032         root = (struct dx_root *) bh->b_data;
2033
2034         /* The 0th block becomes the root, move the dirents out */
2035         fde = &root->dotdot;
2036         de = (struct ext4_dir_entry_2 *)((char *)fde +
2037                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2038         if ((char *) de >= (((char *) root) + blocksize)) {
2039                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2040                 brelse(bh);
2041                 return -EIO;
2042         }
2043         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2044
2045         /* Allocate new block for the 0th block's dirents */
2046         bh2 = ext4_append(handle, dir, &block);
2047         if (IS_ERR(bh2)) {
2048                 brelse(bh);
2049                 return PTR_ERR(bh2);
2050         }
2051         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2052         data1 = bh2->b_data;
2053
2054         memcpy (data1, de, len);
2055         de = (struct ext4_dir_entry_2 *) data1;
2056         top = data1 + len;
2057         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2058                 de = de2;
2059         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2060                                            (char *) de,
2061                                            blocksize);
2062
2063         if (csum_size) {
2064                 t = EXT4_DIRENT_TAIL(data1, blocksize);
2065                 initialize_dirent_tail(t, blocksize);
2066         }
2067
2068         /* Initialize the root; the dot dirents already exist */
2069         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2070         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2071                                            blocksize);
2072         memset (&root->info, 0, sizeof(root->info));
2073         root->info.info_length = sizeof(root->info);
2074         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2075         entries = root->entries;
2076         dx_set_block(entries, 1);
2077         dx_set_count(entries, 1);
2078         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2079
2080         /* Initialize as for dx_probe */
2081         hinfo.hash_version = root->info.hash_version;
2082         if (hinfo.hash_version <= DX_HASH_TEA)
2083                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2084         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2085 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2086         res = ext4_fname_usr_to_hash(ctx, &dentry->d_name, &hinfo);
2087         if (res < 0) {
2088                 ext4_put_fname_crypto_ctx(&ctx);
2089                 ext4_mark_inode_dirty(handle, dir);
2090                 brelse(bh);
2091                 return res;
2092         }
2093         ext4_put_fname_crypto_ctx(&ctx);
2094 #else
2095         ext4fs_dirhash(name, namelen, &hinfo);
2096 #endif
2097         memset(frames, 0, sizeof(frames));
2098         frame = frames;
2099         frame->entries = entries;
2100         frame->at = entries;
2101         frame->bh = bh;
2102         bh = bh2;
2103
2104         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2105         if (retval)
2106                 goto out_frames;
2107         retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
2108         if (retval)
2109                 goto out_frames;
2110
2111         de = do_split(handle,dir, &bh, frame, &hinfo);
2112         if (IS_ERR(de)) {
2113                 retval = PTR_ERR(de);
2114                 goto out_frames;
2115         }
2116         dx_release(frames);
2117
2118         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
2119         brelse(bh);
2120         return retval;
2121 out_frames:
2122         /*
2123          * Even if the block split failed, we have to properly write
2124          * out all the changes we did so far. Otherwise we can end up
2125          * with corrupted filesystem.
2126          */
2127         ext4_mark_inode_dirty(handle, dir);
2128         dx_release(frames);
2129         return retval;
2130 }
2131
2132 /*
2133  *      ext4_add_entry()
2134  *
2135  * adds a file entry to the specified directory, using the same
2136  * semantics as ext4_find_entry(). It returns NULL if it failed.
2137  *
2138  * NOTE!! The inode part of 'de' is left at 0 - which means you
2139  * may not sleep between calling this and putting something into
2140  * the entry, as someone else might have used it while you slept.
2141  */
2142 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2143                           struct inode *inode)
2144 {
2145         struct inode *dir = d_inode(dentry->d_parent);
2146         struct buffer_head *bh = NULL;
2147         struct ext4_dir_entry_2 *de;
2148         struct ext4_dir_entry_tail *t;
2149         struct super_block *sb;
2150         int     retval;
2151         int     dx_fallback=0;
2152         unsigned blocksize;
2153         ext4_lblk_t block, blocks;
2154         int     csum_size = 0;
2155
2156         if (ext4_has_metadata_csum(inode->i_sb))
2157                 csum_size = sizeof(struct ext4_dir_entry_tail);
2158
2159         sb = dir->i_sb;
2160         blocksize = sb->s_blocksize;
2161         if (!dentry->d_name.len)
2162                 return -EINVAL;
2163
2164         if (ext4_has_inline_data(dir)) {
2165                 retval = ext4_try_add_inline_entry(handle, dentry, inode);
2166                 if (retval < 0)
2167                         return retval;
2168                 if (retval == 1) {
2169                         retval = 0;
2170                         goto out;
2171                 }
2172         }
2173
2174         if (is_dx(dir)) {
2175                 retval = ext4_dx_add_entry(handle, dentry, inode);
2176                 if (!retval || (retval != ERR_BAD_DX_DIR))
2177                         goto out;
2178                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2179                 dx_fallback++;
2180                 ext4_mark_inode_dirty(handle, dir);
2181         }
2182         blocks = dir->i_size >> sb->s_blocksize_bits;
2183         for (block = 0; block < blocks; block++) {
2184                 bh = ext4_read_dirblock(dir, block, DIRENT);
2185                 if (IS_ERR(bh))
2186                         return PTR_ERR(bh);
2187
2188                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
2189                 if (retval != -ENOSPC)
2190                         goto out;
2191
2192                 if (blocks == 1 && !dx_fallback &&
2193                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
2194                         retval = make_indexed_dir(handle, dentry, inode, bh);
2195                         bh = NULL; /* make_indexed_dir releases bh */
2196                         goto out;
2197                 }
2198                 brelse(bh);
2199         }
2200         bh = ext4_append(handle, dir, &block);
2201         if (IS_ERR(bh))
2202                 return PTR_ERR(bh);
2203         de = (struct ext4_dir_entry_2 *) bh->b_data;
2204         de->inode = 0;
2205         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2206
2207         if (csum_size) {
2208                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2209                 initialize_dirent_tail(t, blocksize);
2210         }
2211
2212         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
2213 out:
2214         brelse(bh);
2215         if (retval == 0)
2216                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2217         return retval;
2218 }
2219
2220 /*
2221  * Returns 0 for success, or a negative error value
2222  */
2223 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
2224                              struct inode *inode)
2225 {
2226         struct dx_frame frames[2], *frame;
2227         struct dx_entry *entries, *at;
2228         struct dx_hash_info hinfo;
2229         struct buffer_head *bh;
2230         struct inode *dir = d_inode(dentry->d_parent);
2231         struct super_block *sb = dir->i_sb;
2232         struct ext4_dir_entry_2 *de;
2233         int err;
2234
2235         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames);
2236         if (IS_ERR(frame))
2237                 return PTR_ERR(frame);
2238         entries = frame->entries;
2239         at = frame->at;
2240         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2241         if (IS_ERR(bh)) {
2242                 err = PTR_ERR(bh);
2243                 bh = NULL;
2244                 goto cleanup;
2245         }
2246
2247         BUFFER_TRACE(bh, "get_write_access");
2248         err = ext4_journal_get_write_access(handle, bh);
2249         if (err)
2250                 goto journal_error;
2251
2252         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
2253         if (err != -ENOSPC)
2254                 goto cleanup;
2255
2256         /* Block full, should compress but for now just split */
2257         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2258                        dx_get_count(entries), dx_get_limit(entries)));
2259         /* Need to split index? */
2260         if (dx_get_count(entries) == dx_get_limit(entries)) {
2261                 ext4_lblk_t newblock;
2262                 unsigned icount = dx_get_count(entries);
2263                 int levels = frame - frames;
2264                 struct dx_entry *entries2;
2265                 struct dx_node *node2;
2266                 struct buffer_head *bh2;
2267
2268                 if (levels && (dx_get_count(frames->entries) ==
2269                                dx_get_limit(frames->entries))) {
2270                         ext4_warning(sb, "Directory index full!");
2271                         err = -ENOSPC;
2272                         goto cleanup;
2273                 }
2274                 bh2 = ext4_append(handle, dir, &newblock);
2275                 if (IS_ERR(bh2)) {
2276                         err = PTR_ERR(bh2);
2277                         goto cleanup;
2278                 }
2279                 node2 = (struct dx_node *)(bh2->b_data);
2280                 entries2 = node2->entries;
2281                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2282                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2283                                                            sb->s_blocksize);
2284                 BUFFER_TRACE(frame->bh, "get_write_access");
2285                 err = ext4_journal_get_write_access(handle, frame->bh);
2286                 if (err)
2287                         goto journal_error;
2288                 if (levels) {
2289                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2290                         unsigned hash2 = dx_get_hash(entries + icount1);
2291                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2292                                        icount1, icount2));
2293
2294                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2295                         err = ext4_journal_get_write_access(handle,
2296                                                              frames[0].bh);
2297                         if (err)
2298                                 goto journal_error;
2299
2300                         memcpy((char *) entries2, (char *) (entries + icount1),
2301                                icount2 * sizeof(struct dx_entry));
2302                         dx_set_count(entries, icount1);
2303                         dx_set_count(entries2, icount2);
2304                         dx_set_limit(entries2, dx_node_limit(dir));
2305
2306                         /* Which index block gets the new entry? */
2307                         if (at - entries >= icount1) {
2308                                 frame->at = at = at - entries - icount1 + entries2;
2309                                 frame->entries = entries = entries2;
2310                                 swap(frame->bh, bh2);
2311                         }
2312                         dx_insert_block(frames + 0, hash2, newblock);
2313                         dxtrace(dx_show_index("node", frames[1].entries));
2314                         dxtrace(dx_show_index("node",
2315                                ((struct dx_node *) bh2->b_data)->entries));
2316                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2317                         if (err)
2318                                 goto journal_error;
2319                         brelse (bh2);
2320                 } else {
2321                         dxtrace(printk(KERN_DEBUG
2322                                        "Creating second level index...\n"));
2323                         memcpy((char *) entries2, (char *) entries,
2324                                icount * sizeof(struct dx_entry));
2325                         dx_set_limit(entries2, dx_node_limit(dir));
2326
2327                         /* Set up root */
2328                         dx_set_count(entries, 1);
2329                         dx_set_block(entries + 0, newblock);
2330                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2331
2332                         /* Add new access path frame */
2333                         frame = frames + 1;
2334                         frame->at = at = at - entries + entries2;
2335                         frame->entries = entries = entries2;
2336                         frame->bh = bh2;
2337                         err = ext4_journal_get_write_access(handle,
2338                                                              frame->bh);
2339                         if (err)
2340                                 goto journal_error;
2341                 }
2342                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2343                 if (err) {
2344                         ext4_std_error(inode->i_sb, err);
2345                         goto cleanup;
2346                 }
2347         }
2348         de = do_split(handle, dir, &bh, frame, &hinfo);
2349         if (IS_ERR(de)) {
2350                 err = PTR_ERR(de);
2351                 goto cleanup;
2352         }
2353         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2354         goto cleanup;
2355
2356 journal_error:
2357         ext4_std_error(dir->i_sb, err);
2358 cleanup:
2359         brelse(bh);
2360         dx_release(frames);
2361         return err;
2362 }
2363
2364 /*
2365  * ext4_generic_delete_entry deletes a directory entry by merging it
2366  * with the previous entry
2367  */
2368 int ext4_generic_delete_entry(handle_t *handle,
2369                               struct inode *dir,
2370                               struct ext4_dir_entry_2 *de_del,
2371                               struct buffer_head *bh,
2372                               void *entry_buf,
2373                               int buf_size,
2374                               int csum_size)
2375 {
2376         struct ext4_dir_entry_2 *de, *pde;
2377         unsigned int blocksize = dir->i_sb->s_blocksize;
2378         int i;
2379
2380         i = 0;
2381         pde = NULL;
2382         de = (struct ext4_dir_entry_2 *)entry_buf;
2383         while (i < buf_size - csum_size) {
2384                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2385                                          bh->b_data, bh->b_size, i))
2386                         return -EIO;
2387                 if (de == de_del)  {
2388                         if (pde)
2389                                 pde->rec_len = ext4_rec_len_to_disk(
2390                                         ext4_rec_len_from_disk(pde->rec_len,
2391                                                                blocksize) +
2392                                         ext4_rec_len_from_disk(de->rec_len,
2393                                                                blocksize),
2394                                         blocksize);
2395                         else
2396                                 de->inode = 0;
2397                         dir->i_version++;
2398                         return 0;
2399                 }
2400                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2401                 pde = de;
2402                 de = ext4_next_entry(de, blocksize);
2403         }
2404         return -ENOENT;
2405 }
2406
2407 static int ext4_delete_entry(handle_t *handle,
2408                              struct inode *dir,
2409                              struct ext4_dir_entry_2 *de_del,
2410                              struct buffer_head *bh)
2411 {
2412         int err, csum_size = 0;
2413
2414         if (ext4_has_inline_data(dir)) {
2415                 int has_inline_data = 1;
2416                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2417                                                &has_inline_data);
2418                 if (has_inline_data)
2419                         return err;
2420         }
2421
2422         if (ext4_has_metadata_csum(dir->i_sb))
2423                 csum_size = sizeof(struct ext4_dir_entry_tail);
2424
2425         BUFFER_TRACE(bh, "get_write_access");
2426         err = ext4_journal_get_write_access(handle, bh);
2427         if (unlikely(err))
2428                 goto out;
2429
2430         err = ext4_generic_delete_entry(handle, dir, de_del,
2431                                         bh, bh->b_data,
2432                                         dir->i_sb->s_blocksize, csum_size);
2433         if (err)
2434                 goto out;
2435
2436         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2437         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2438         if (unlikely(err))
2439                 goto out;
2440
2441         return 0;
2442 out:
2443         if (err != -ENOENT)
2444                 ext4_std_error(dir->i_sb, err);
2445         return err;
2446 }
2447
2448 /*
2449  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2450  * since this indicates that nlinks count was previously 1.
2451  */
2452 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2453 {
2454         inc_nlink(inode);
2455         if (is_dx(inode) && inode->i_nlink > 1) {
2456                 /* limit is 16-bit i_links_count */
2457                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2458                         set_nlink(inode, 1);
2459                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2460                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2461                 }
2462         }
2463 }
2464
2465 /*
2466  * If a directory had nlink == 1, then we should let it be 1. This indicates
2467  * directory has >EXT4_LINK_MAX subdirs.
2468  */
2469 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2470 {
2471         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2472                 drop_nlink(inode);
2473 }
2474
2475
2476 static int ext4_add_nondir(handle_t *handle,
2477                 struct dentry *dentry, struct inode *inode)
2478 {
2479         int err = ext4_add_entry(handle, dentry, inode);
2480         if (!err) {
2481                 ext4_mark_inode_dirty(handle, inode);
2482                 unlock_new_inode(inode);
2483                 d_instantiate(dentry, inode);
2484                 return 0;
2485         }
2486         drop_nlink(inode);
2487         unlock_new_inode(inode);
2488         iput(inode);
2489         return err;
2490 }
2491
2492 /*
2493  * By the time this is called, we already have created
2494  * the directory cache entry for the new file, but it
2495  * is so far negative - it has no inode.
2496  *
2497  * If the create succeeds, we fill in the inode information
2498  * with d_instantiate().
2499  */
2500 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2501                        bool excl)
2502 {
2503         handle_t *handle;
2504         struct inode *inode;
2505         int err, credits, retries = 0;
2506
2507         dquot_initialize(dir);
2508
2509         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2510                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2511 retry:
2512         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2513                                             NULL, EXT4_HT_DIR, credits);
2514         handle = ext4_journal_current_handle();
2515         err = PTR_ERR(inode);
2516         if (!IS_ERR(inode)) {
2517                 inode->i_op = &ext4_file_inode_operations;
2518                 inode->i_fop = &ext4_file_operations;
2519                 ext4_set_aops(inode);
2520                 err = 0;
2521 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2522                 if (!err && (ext4_encrypted_inode(dir) ||
2523                              DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)))) {
2524                         err = ext4_inherit_context(dir, inode);
2525                         if (err) {
2526                                 clear_nlink(inode);
2527                                 unlock_new_inode(inode);
2528                                 iput(inode);
2529                         }
2530                 }
2531 #endif
2532                 if (!err)
2533                         err = ext4_add_nondir(handle, dentry, inode);
2534                 if (!err && IS_DIRSYNC(dir))
2535                         ext4_handle_sync(handle);
2536         }
2537         if (handle)
2538                 ext4_journal_stop(handle);
2539         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2540                 goto retry;
2541         return err;
2542 }
2543
2544 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2545                       umode_t mode, dev_t rdev)
2546 {
2547         handle_t *handle;
2548         struct inode *inode;
2549         int err, credits, retries = 0;
2550
2551         if (!new_valid_dev(rdev))
2552                 return -EINVAL;
2553
2554         dquot_initialize(dir);
2555
2556         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2557                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2558 retry:
2559         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2560                                             NULL, EXT4_HT_DIR, credits);
2561         handle = ext4_journal_current_handle();
2562         err = PTR_ERR(inode);
2563         if (!IS_ERR(inode)) {
2564                 init_special_inode(inode, inode->i_mode, rdev);
2565                 inode->i_op = &ext4_special_inode_operations;
2566                 err = ext4_add_nondir(handle, dentry, inode);
2567                 if (!err && IS_DIRSYNC(dir))
2568                         ext4_handle_sync(handle);
2569         }
2570         if (handle)
2571                 ext4_journal_stop(handle);
2572         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2573                 goto retry;
2574         return err;
2575 }
2576
2577 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2578 {
2579         handle_t *handle;
2580         struct inode *inode;
2581         int err, retries = 0;
2582
2583         dquot_initialize(dir);
2584
2585 retry:
2586         inode = ext4_new_inode_start_handle(dir, mode,
2587                                             NULL, 0, NULL,
2588                                             EXT4_HT_DIR,
2589                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2590                           4 + EXT4_XATTR_TRANS_BLOCKS);
2591         handle = ext4_journal_current_handle();
2592         err = PTR_ERR(inode);
2593         if (!IS_ERR(inode)) {
2594                 inode->i_op = &ext4_file_inode_operations;
2595                 inode->i_fop = &ext4_file_operations;
2596                 ext4_set_aops(inode);
2597                 d_tmpfile(dentry, inode);
2598                 err = ext4_orphan_add(handle, inode);
2599                 if (err)
2600                         goto err_unlock_inode;
2601                 mark_inode_dirty(inode);
2602                 unlock_new_inode(inode);
2603         }
2604         if (handle)
2605                 ext4_journal_stop(handle);
2606         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2607                 goto retry;
2608         return err;
2609 err_unlock_inode:
2610         ext4_journal_stop(handle);
2611         unlock_new_inode(inode);
2612         return err;
2613 }
2614
2615 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2616                           struct ext4_dir_entry_2 *de,
2617                           int blocksize, int csum_size,
2618                           unsigned int parent_ino, int dotdot_real_len)
2619 {
2620         de->inode = cpu_to_le32(inode->i_ino);
2621         de->name_len = 1;
2622         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2623                                            blocksize);
2624         strcpy(de->name, ".");
2625         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2626
2627         de = ext4_next_entry(de, blocksize);
2628         de->inode = cpu_to_le32(parent_ino);
2629         de->name_len = 2;
2630         if (!dotdot_real_len)
2631                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2632                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2633                                         blocksize);
2634         else
2635                 de->rec_len = ext4_rec_len_to_disk(
2636                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2637         strcpy(de->name, "..");
2638         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2639
2640         return ext4_next_entry(de, blocksize);
2641 }
2642
2643 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2644                              struct inode *inode)
2645 {
2646         struct buffer_head *dir_block = NULL;
2647         struct ext4_dir_entry_2 *de;
2648         struct ext4_dir_entry_tail *t;
2649         ext4_lblk_t block = 0;
2650         unsigned int blocksize = dir->i_sb->s_blocksize;
2651         int csum_size = 0;
2652         int err;
2653
2654         if (ext4_has_metadata_csum(dir->i_sb))
2655                 csum_size = sizeof(struct ext4_dir_entry_tail);
2656
2657         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2658                 err = ext4_try_create_inline_dir(handle, dir, inode);
2659                 if (err < 0 && err != -ENOSPC)
2660                         goto out;
2661                 if (!err)
2662                         goto out;
2663         }
2664
2665         inode->i_size = 0;
2666         dir_block = ext4_append(handle, inode, &block);
2667         if (IS_ERR(dir_block))
2668                 return PTR_ERR(dir_block);
2669         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2670         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2671         set_nlink(inode, 2);
2672         if (csum_size) {
2673                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2674                 initialize_dirent_tail(t, blocksize);
2675         }
2676
2677         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2678         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2679         if (err)
2680                 goto out;
2681         set_buffer_verified(dir_block);
2682 out:
2683         brelse(dir_block);
2684         return err;
2685 }
2686
2687 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2688 {
2689         handle_t *handle;
2690         struct inode *inode;
2691         int err, credits, retries = 0;
2692
2693         if (EXT4_DIR_LINK_MAX(dir))
2694                 return -EMLINK;
2695
2696         dquot_initialize(dir);
2697
2698         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2699                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2700 retry:
2701         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2702                                             &dentry->d_name,
2703                                             0, NULL, EXT4_HT_DIR, credits);
2704         handle = ext4_journal_current_handle();
2705         err = PTR_ERR(inode);
2706         if (IS_ERR(inode))
2707                 goto out_stop;
2708
2709         inode->i_op = &ext4_dir_inode_operations;
2710         inode->i_fop = &ext4_dir_operations;
2711         err = ext4_init_new_dir(handle, dir, inode);
2712         if (err)
2713                 goto out_clear_inode;
2714 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2715         if (ext4_encrypted_inode(dir) ||
2716             DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) {
2717                 err = ext4_inherit_context(dir, inode);
2718                 if (err)
2719                         goto out_clear_inode;
2720         }
2721 #endif
2722         err = ext4_mark_inode_dirty(handle, inode);
2723         if (!err)
2724                 err = ext4_add_entry(handle, dentry, inode);
2725         if (err) {
2726 out_clear_inode:
2727                 clear_nlink(inode);
2728                 unlock_new_inode(inode);
2729                 ext4_mark_inode_dirty(handle, inode);
2730                 iput(inode);
2731                 goto out_stop;
2732         }
2733         ext4_inc_count(handle, dir);
2734         ext4_update_dx_flag(dir);
2735         err = ext4_mark_inode_dirty(handle, dir);
2736         if (err)
2737                 goto out_clear_inode;
2738         unlock_new_inode(inode);
2739         d_instantiate(dentry, inode);
2740         if (IS_DIRSYNC(dir))
2741                 ext4_handle_sync(handle);
2742
2743 out_stop:
2744         if (handle)
2745                 ext4_journal_stop(handle);
2746         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2747                 goto retry;
2748         return err;
2749 }
2750
2751 /*
2752  * routine to check that the specified directory is empty (for rmdir)
2753  */
2754 int ext4_empty_dir(struct inode *inode)
2755 {
2756         unsigned int offset;
2757         struct buffer_head *bh;
2758         struct ext4_dir_entry_2 *de, *de1;
2759         struct super_block *sb;
2760         int err = 0;
2761
2762         if (ext4_has_inline_data(inode)) {
2763                 int has_inline_data = 1;
2764
2765                 err = empty_inline_dir(inode, &has_inline_data);
2766                 if (has_inline_data)
2767                         return err;
2768         }
2769
2770         sb = inode->i_sb;
2771         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2772                 EXT4_ERROR_INODE(inode, "invalid size");
2773                 return 1;
2774         }
2775         bh = ext4_read_dirblock(inode, 0, EITHER);
2776         if (IS_ERR(bh))
2777                 return 1;
2778
2779         de = (struct ext4_dir_entry_2 *) bh->b_data;
2780         de1 = ext4_next_entry(de, sb->s_blocksize);
2781         if (le32_to_cpu(de->inode) != inode->i_ino ||
2782                         !le32_to_cpu(de1->inode) ||
2783                         strcmp(".", de->name) ||
2784                         strcmp("..", de1->name)) {
2785                 ext4_warning(inode->i_sb,
2786                              "bad directory (dir #%lu) - no `.' or `..'",
2787                              inode->i_ino);
2788                 brelse(bh);
2789                 return 1;
2790         }
2791         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2792                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2793         de = ext4_next_entry(de1, sb->s_blocksize);
2794         while (offset < inode->i_size) {
2795                 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2796                         unsigned int lblock;
2797                         err = 0;
2798                         brelse(bh);
2799                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2800                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2801                         if (IS_ERR(bh))
2802                                 return 1;
2803                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2804                 }
2805                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2806                                          bh->b_data, bh->b_size, offset)) {
2807                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2808                                                          sb->s_blocksize);
2809                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2810                         continue;
2811                 }
2812                 if (le32_to_cpu(de->inode)) {
2813                         brelse(bh);
2814                         return 0;
2815                 }
2816                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2817                 de = ext4_next_entry(de, sb->s_blocksize);
2818         }
2819         brelse(bh);
2820         return 1;
2821 }
2822
2823 /*
2824  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2825  * such inodes, starting at the superblock, in case we crash before the
2826  * file is closed/deleted, or in case the inode truncate spans multiple
2827  * transactions and the last transaction is not recovered after a crash.
2828  *
2829  * At filesystem recovery time, we walk this list deleting unlinked
2830  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2831  *
2832  * Orphan list manipulation functions must be called under i_mutex unless
2833  * we are just creating the inode or deleting it.
2834  */
2835 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2836 {
2837         struct super_block *sb = inode->i_sb;
2838         struct ext4_sb_info *sbi = EXT4_SB(sb);
2839         struct ext4_iloc iloc;
2840         int err = 0, rc;
2841         bool dirty = false;
2842
2843         if (!sbi->s_journal || is_bad_inode(inode))
2844                 return 0;
2845
2846         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2847                      !mutex_is_locked(&inode->i_mutex));
2848         /*
2849          * Exit early if inode already is on orphan list. This is a big speedup
2850          * since we don't have to contend on the global s_orphan_lock.
2851          */
2852         if (!list_empty(&EXT4_I(inode)->i_orphan))
2853                 return 0;
2854
2855         /*
2856          * Orphan handling is only valid for files with data blocks
2857          * being truncated, or files being unlinked. Note that we either
2858          * hold i_mutex, or the inode can not be referenced from outside,
2859          * so i_nlink should not be bumped due to race
2860          */
2861         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2862                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2863
2864         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2865         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2866         if (err)
2867                 goto out;
2868
2869         err = ext4_reserve_inode_write(handle, inode, &iloc);
2870         if (err)
2871                 goto out;
2872
2873         mutex_lock(&sbi->s_orphan_lock);
2874         /*
2875          * Due to previous errors inode may be already a part of on-disk
2876          * orphan list. If so skip on-disk list modification.
2877          */
2878         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2879             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2880                 /* Insert this inode at the head of the on-disk orphan list */
2881                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2882                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2883                 dirty = true;
2884         }
2885         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2886         mutex_unlock(&sbi->s_orphan_lock);
2887
2888         if (dirty) {
2889                 err = ext4_handle_dirty_super(handle, sb);
2890                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2891                 if (!err)
2892                         err = rc;
2893                 if (err) {
2894                         /*
2895                          * We have to remove inode from in-memory list if
2896                          * addition to on disk orphan list failed. Stray orphan
2897                          * list entries can cause panics at unmount time.
2898                          */
2899                         mutex_lock(&sbi->s_orphan_lock);
2900                         list_del(&EXT4_I(inode)->i_orphan);
2901                         mutex_unlock(&sbi->s_orphan_lock);
2902                 }
2903         }
2904         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2905         jbd_debug(4, "orphan inode %lu will point to %d\n",
2906                         inode->i_ino, NEXT_ORPHAN(inode));
2907 out:
2908         ext4_std_error(sb, err);
2909         return err;
2910 }
2911
2912 /*
2913  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2914  * of such inodes stored on disk, because it is finally being cleaned up.
2915  */
2916 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2917 {
2918         struct list_head *prev;
2919         struct ext4_inode_info *ei = EXT4_I(inode);
2920         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2921         __u32 ino_next;
2922         struct ext4_iloc iloc;
2923         int err = 0;
2924
2925         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2926                 return 0;
2927
2928         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2929                      !mutex_is_locked(&inode->i_mutex));
2930         /* Do this quick check before taking global s_orphan_lock. */
2931         if (list_empty(&ei->i_orphan))
2932                 return 0;
2933
2934         if (handle) {
2935                 /* Grab inode buffer early before taking global s_orphan_lock */
2936                 err = ext4_reserve_inode_write(handle, inode, &iloc);
2937         }
2938
2939         mutex_lock(&sbi->s_orphan_lock);
2940         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2941
2942         prev = ei->i_orphan.prev;
2943         list_del_init(&ei->i_orphan);
2944
2945         /* If we're on an error path, we may not have a valid
2946          * transaction handle with which to update the orphan list on
2947          * disk, but we still need to remove the inode from the linked
2948          * list in memory. */
2949         if (!handle || err) {
2950                 mutex_unlock(&sbi->s_orphan_lock);
2951                 goto out_err;
2952         }
2953
2954         ino_next = NEXT_ORPHAN(inode);
2955         if (prev == &sbi->s_orphan) {
2956                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2957                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2958                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2959                 if (err) {
2960                         mutex_unlock(&sbi->s_orphan_lock);
2961                         goto out_brelse;
2962                 }
2963                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2964                 mutex_unlock(&sbi->s_orphan_lock);
2965                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2966         } else {
2967                 struct ext4_iloc iloc2;
2968                 struct inode *i_prev =
2969                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2970
2971                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2972                           i_prev->i_ino, ino_next);
2973                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2974                 if (err) {
2975                         mutex_unlock(&sbi->s_orphan_lock);
2976                         goto out_brelse;
2977                 }
2978                 NEXT_ORPHAN(i_prev) = ino_next;
2979                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2980                 mutex_unlock(&sbi->s_orphan_lock);
2981         }
2982         if (err)
2983                 goto out_brelse;
2984         NEXT_ORPHAN(inode) = 0;
2985         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2986 out_err:
2987         ext4_std_error(inode->i_sb, err);
2988         return err;
2989
2990 out_brelse:
2991         brelse(iloc.bh);
2992         goto out_err;
2993 }
2994
2995 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2996 {
2997         int retval;
2998         struct inode *inode;
2999         struct buffer_head *bh;
3000         struct ext4_dir_entry_2 *de;
3001         handle_t *handle = NULL;
3002
3003         /* Initialize quotas before so that eventual writes go in
3004          * separate transaction */
3005         dquot_initialize(dir);
3006         dquot_initialize(d_inode(dentry));
3007
3008         retval = -ENOENT;
3009         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3010         if (IS_ERR(bh))
3011                 return PTR_ERR(bh);
3012         if (!bh)
3013                 goto end_rmdir;
3014
3015         inode = d_inode(dentry);
3016
3017         retval = -EIO;
3018         if (le32_to_cpu(de->inode) != inode->i_ino)
3019                 goto end_rmdir;
3020
3021         retval = -ENOTEMPTY;
3022         if (!ext4_empty_dir(inode))
3023                 goto end_rmdir;
3024
3025         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3026                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3027         if (IS_ERR(handle)) {
3028                 retval = PTR_ERR(handle);
3029                 handle = NULL;
3030                 goto end_rmdir;
3031         }
3032
3033         if (IS_DIRSYNC(dir))
3034                 ext4_handle_sync(handle);
3035
3036         retval = ext4_delete_entry(handle, dir, de, bh);
3037         if (retval)
3038                 goto end_rmdir;
3039         if (!EXT4_DIR_LINK_EMPTY(inode))
3040                 ext4_warning(inode->i_sb,
3041                              "empty directory has too many links (%d)",
3042                              inode->i_nlink);
3043         inode->i_version++;
3044         clear_nlink(inode);
3045         /* There's no need to set i_disksize: the fact that i_nlink is
3046          * zero will ensure that the right thing happens during any
3047          * recovery. */
3048         inode->i_size = 0;
3049         ext4_orphan_add(handle, inode);
3050         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
3051         ext4_mark_inode_dirty(handle, inode);
3052         ext4_dec_count(handle, dir);
3053         ext4_update_dx_flag(dir);
3054         ext4_mark_inode_dirty(handle, dir);
3055
3056 end_rmdir:
3057         brelse(bh);
3058         if (handle)
3059                 ext4_journal_stop(handle);
3060         return retval;
3061 }
3062
3063 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3064 {
3065         int retval;
3066         struct inode *inode;
3067         struct buffer_head *bh;
3068         struct ext4_dir_entry_2 *de;
3069         handle_t *handle = NULL;
3070
3071         trace_ext4_unlink_enter(dir, dentry);
3072         /* Initialize quotas before so that eventual writes go
3073          * in separate transaction */
3074         dquot_initialize(dir);
3075         dquot_initialize(d_inode(dentry));
3076
3077         retval = -ENOENT;
3078         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3079         if (IS_ERR(bh))
3080                 return PTR_ERR(bh);
3081         if (!bh)
3082                 goto end_unlink;
3083
3084         inode = d_inode(dentry);
3085
3086         retval = -EIO;
3087         if (le32_to_cpu(de->inode) != inode->i_ino)
3088                 goto end_unlink;
3089
3090         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3091                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3092         if (IS_ERR(handle)) {
3093                 retval = PTR_ERR(handle);
3094                 handle = NULL;
3095                 goto end_unlink;
3096         }
3097
3098         if (IS_DIRSYNC(dir))
3099                 ext4_handle_sync(handle);
3100
3101         if (!inode->i_nlink) {
3102                 ext4_warning(inode->i_sb,
3103                              "Deleting nonexistent file (%lu), %d",
3104                              inode->i_ino, inode->i_nlink);
3105                 set_nlink(inode, 1);
3106         }
3107         retval = ext4_delete_entry(handle, dir, de, bh);
3108         if (retval)
3109                 goto end_unlink;
3110         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3111         ext4_update_dx_flag(dir);
3112         ext4_mark_inode_dirty(handle, dir);
3113         drop_nlink(inode);
3114         if (!inode->i_nlink)
3115                 ext4_orphan_add(handle, inode);
3116         inode->i_ctime = ext4_current_time(inode);
3117         ext4_mark_inode_dirty(handle, inode);
3118
3119 end_unlink:
3120         brelse(bh);
3121         if (handle)
3122                 ext4_journal_stop(handle);
3123         trace_ext4_unlink_exit(dentry, retval);
3124         return retval;
3125 }
3126
3127 static int ext4_symlink(struct inode *dir,
3128                         struct dentry *dentry, const char *symname)
3129 {
3130         handle_t *handle;
3131         struct inode *inode;
3132         int err, len = strlen(symname);
3133         int credits;
3134         bool encryption_required;
3135         struct ext4_str disk_link;
3136         struct ext4_encrypted_symlink_data *sd = NULL;
3137
3138         disk_link.len = len + 1;
3139         disk_link.name = (char *) symname;
3140
3141         encryption_required = (ext4_encrypted_inode(dir) ||
3142                                DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3143         if (encryption_required)
3144                 disk_link.len = encrypted_symlink_data_len(len) + 1;
3145         if (disk_link.len > dir->i_sb->s_blocksize)
3146                 return -ENAMETOOLONG;
3147
3148         dquot_initialize(dir);
3149
3150         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3151                 /*
3152                  * For non-fast symlinks, we just allocate inode and put it on
3153                  * orphan list in the first transaction => we need bitmap,
3154                  * group descriptor, sb, inode block, quota blocks, and
3155                  * possibly selinux xattr blocks.
3156                  */
3157                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3158                           EXT4_XATTR_TRANS_BLOCKS;
3159         } else {
3160                 /*
3161                  * Fast symlink. We have to add entry to directory
3162                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3163                  * allocate new inode (bitmap, group descriptor, inode block,
3164                  * quota blocks, sb is already counted in previous macros).
3165                  */
3166                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3167                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3168         }
3169
3170         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3171                                             &dentry->d_name, 0, NULL,
3172                                             EXT4_HT_DIR, credits);
3173         handle = ext4_journal_current_handle();
3174         if (IS_ERR(inode)) {
3175                 if (handle)
3176                         ext4_journal_stop(handle);
3177                 return PTR_ERR(inode);
3178         }
3179
3180         if (encryption_required) {
3181                 struct ext4_fname_crypto_ctx *ctx = NULL;
3182                 struct qstr istr;
3183                 struct ext4_str ostr;
3184
3185                 sd = kzalloc(disk_link.len, GFP_NOFS);
3186                 if (!sd) {
3187                         err = -ENOMEM;
3188                         goto err_drop_inode;
3189                 }
3190                 err = ext4_inherit_context(dir, inode);
3191                 if (err)
3192                         goto err_drop_inode;
3193                 ctx = ext4_get_fname_crypto_ctx(inode,
3194                                                 inode->i_sb->s_blocksize);
3195                 if (IS_ERR_OR_NULL(ctx)) {
3196                         /* We just set the policy, so ctx should not be NULL */
3197                         err = (ctx == NULL) ? -EIO : PTR_ERR(ctx);
3198                         goto err_drop_inode;
3199                 }
3200                 istr.name = (const unsigned char *) symname;
3201                 istr.len = len;
3202                 ostr.name = sd->encrypted_path;
3203                 err = ext4_fname_usr_to_disk(ctx, &istr, &ostr);
3204                 ext4_put_fname_crypto_ctx(&ctx);
3205                 if (err < 0)
3206                         goto err_drop_inode;
3207                 sd->len = cpu_to_le16(ostr.len);
3208                 disk_link.name = (char *) sd;
3209         }
3210
3211         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3212                 inode->i_op = &ext4_symlink_inode_operations;
3213                 ext4_set_aops(inode);
3214                 /*
3215                  * We cannot call page_symlink() with transaction started
3216                  * because it calls into ext4_write_begin() which can wait
3217                  * for transaction commit if we are running out of space
3218                  * and thus we deadlock. So we have to stop transaction now
3219                  * and restart it when symlink contents is written.
3220                  *
3221                  * To keep fs consistent in case of crash, we have to put inode
3222                  * to orphan list in the mean time.
3223                  */
3224                 drop_nlink(inode);
3225                 err = ext4_orphan_add(handle, inode);
3226                 ext4_journal_stop(handle);
3227                 handle = NULL;
3228                 if (err)
3229                         goto err_drop_inode;
3230                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3231                 if (err)
3232                         goto err_drop_inode;
3233                 /*
3234                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3235                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3236                  */
3237                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3238                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3239                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3240                 if (IS_ERR(handle)) {
3241                         err = PTR_ERR(handle);
3242                         handle = NULL;
3243                         goto err_drop_inode;
3244                 }
3245                 set_nlink(inode, 1);
3246                 err = ext4_orphan_del(handle, inode);
3247                 if (err)
3248                         goto err_drop_inode;
3249         } else {
3250                 /* clear the extent format for fast symlink */
3251                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3252                 inode->i_op = encryption_required ?
3253                         &ext4_symlink_inode_operations :
3254                         &ext4_fast_symlink_inode_operations;
3255                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3256                        disk_link.len);
3257                 inode->i_size = disk_link.len - 1;
3258         }
3259         EXT4_I(inode)->i_disksize = inode->i_size;
3260         err = ext4_add_nondir(handle, dentry, inode);
3261         if (!err && IS_DIRSYNC(dir))
3262                 ext4_handle_sync(handle);
3263
3264         if (handle)
3265                 ext4_journal_stop(handle);
3266         kfree(sd);
3267         return err;
3268 err_drop_inode:
3269         if (handle)
3270                 ext4_journal_stop(handle);
3271         kfree(sd);
3272         clear_nlink(inode);
3273         unlock_new_inode(inode);
3274         iput(inode);
3275         return err;
3276 }
3277
3278 static int ext4_link(struct dentry *old_dentry,
3279                      struct inode *dir, struct dentry *dentry)
3280 {
3281         handle_t *handle;
3282         struct inode *inode = d_inode(old_dentry);
3283         int err, retries = 0;
3284
3285         if (inode->i_nlink >= EXT4_LINK_MAX)
3286                 return -EMLINK;
3287         if (ext4_encrypted_inode(dir) &&
3288             !ext4_is_child_context_consistent_with_parent(dir, inode))
3289                 return -EPERM;
3290         dquot_initialize(dir);
3291
3292 retry:
3293         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3294                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3295                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3296         if (IS_ERR(handle))
3297                 return PTR_ERR(handle);
3298
3299         if (IS_DIRSYNC(dir))
3300                 ext4_handle_sync(handle);
3301
3302         inode->i_ctime = ext4_current_time(inode);
3303         ext4_inc_count(handle, inode);
3304         ihold(inode);
3305
3306         err = ext4_add_entry(handle, dentry, inode);
3307         if (!err) {
3308                 ext4_mark_inode_dirty(handle, inode);
3309                 /* this can happen only for tmpfile being
3310                  * linked the first time
3311                  */
3312                 if (inode->i_nlink == 1)
3313                         ext4_orphan_del(handle, inode);
3314                 d_instantiate(dentry, inode);
3315         } else {
3316                 drop_nlink(inode);
3317                 iput(inode);
3318         }
3319         ext4_journal_stop(handle);
3320         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3321                 goto retry;
3322         return err;
3323 }
3324
3325
3326 /*
3327  * Try to find buffer head where contains the parent block.
3328  * It should be the inode block if it is inlined or the 1st block
3329  * if it is a normal dir.
3330  */
3331 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3332                                         struct inode *inode,
3333                                         int *retval,
3334                                         struct ext4_dir_entry_2 **parent_de,
3335                                         int *inlined)
3336 {
3337         struct buffer_head *bh;
3338
3339         if (!ext4_has_inline_data(inode)) {
3340                 bh = ext4_read_dirblock(inode, 0, EITHER);
3341                 if (IS_ERR(bh)) {
3342                         *retval = PTR_ERR(bh);
3343                         return NULL;
3344                 }
3345                 *parent_de = ext4_next_entry(
3346                                         (struct ext4_dir_entry_2 *)bh->b_data,
3347                                         inode->i_sb->s_blocksize);
3348                 return bh;
3349         }
3350
3351         *inlined = 1;
3352         return ext4_get_first_inline_block(inode, parent_de, retval);
3353 }
3354
3355 struct ext4_renament {
3356         struct inode *dir;
3357         struct dentry *dentry;
3358         struct inode *inode;
3359         bool is_dir;
3360         int dir_nlink_delta;
3361
3362         /* entry for "dentry" */
3363         struct buffer_head *bh;
3364         struct ext4_dir_entry_2 *de;
3365         int inlined;
3366
3367         /* entry for ".." in inode if it's a directory */
3368         struct buffer_head *dir_bh;
3369         struct ext4_dir_entry_2 *parent_de;
3370         int dir_inlined;
3371 };
3372
3373 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3374 {
3375         int retval;
3376
3377         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3378                                               &retval, &ent->parent_de,
3379                                               &ent->dir_inlined);
3380         if (!ent->dir_bh)
3381                 return retval;
3382         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3383                 return -EIO;
3384         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3385         return ext4_journal_get_write_access(handle, ent->dir_bh);
3386 }
3387
3388 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3389                                   unsigned dir_ino)
3390 {
3391         int retval;
3392
3393         ent->parent_de->inode = cpu_to_le32(dir_ino);
3394         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3395         if (!ent->dir_inlined) {
3396                 if (is_dx(ent->inode)) {
3397                         retval = ext4_handle_dirty_dx_node(handle,
3398                                                            ent->inode,
3399                                                            ent->dir_bh);
3400                 } else {
3401                         retval = ext4_handle_dirty_dirent_node(handle,
3402                                                                ent->inode,
3403                                                                ent->dir_bh);
3404                 }
3405         } else {
3406                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3407         }
3408         if (retval) {
3409                 ext4_std_error(ent->dir->i_sb, retval);
3410                 return retval;
3411         }
3412         return 0;
3413 }
3414
3415 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3416                        unsigned ino, unsigned file_type)
3417 {
3418         int retval;
3419
3420         BUFFER_TRACE(ent->bh, "get write access");
3421         retval = ext4_journal_get_write_access(handle, ent->bh);
3422         if (retval)
3423                 return retval;
3424         ent->de->inode = cpu_to_le32(ino);
3425         if (EXT4_HAS_INCOMPAT_FEATURE(ent->dir->i_sb,
3426                                       EXT4_FEATURE_INCOMPAT_FILETYPE))
3427                 ent->de->file_type = file_type;
3428         ent->dir->i_version++;
3429         ent->dir->i_ctime = ent->dir->i_mtime =
3430                 ext4_current_time(ent->dir);
3431         ext4_mark_inode_dirty(handle, ent->dir);
3432         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3433         if (!ent->inlined) {
3434                 retval = ext4_handle_dirty_dirent_node(handle,
3435                                                        ent->dir, ent->bh);
3436                 if (unlikely(retval)) {
3437                         ext4_std_error(ent->dir->i_sb, retval);
3438                         return retval;
3439                 }
3440         }
3441         brelse(ent->bh);
3442         ent->bh = NULL;
3443
3444         return 0;
3445 }
3446
3447 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3448                                   const struct qstr *d_name)
3449 {
3450         int retval = -ENOENT;
3451         struct buffer_head *bh;
3452         struct ext4_dir_entry_2 *de;
3453
3454         bh = ext4_find_entry(dir, d_name, &de, NULL);
3455         if (IS_ERR(bh))
3456                 return PTR_ERR(bh);
3457         if (bh) {
3458                 retval = ext4_delete_entry(handle, dir, de, bh);
3459                 brelse(bh);
3460         }
3461         return retval;
3462 }
3463
3464 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3465                                int force_reread)
3466 {
3467         int retval;
3468         /*
3469          * ent->de could have moved from under us during htree split, so make
3470          * sure that we are deleting the right entry.  We might also be pointing
3471          * to a stale entry in the unused part of ent->bh so just checking inum
3472          * and the name isn't enough.
3473          */
3474         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3475             ent->de->name_len != ent->dentry->d_name.len ||
3476             strncmp(ent->de->name, ent->dentry->d_name.name,
3477                     ent->de->name_len) ||
3478             force_reread) {
3479                 retval = ext4_find_delete_entry(handle, ent->dir,
3480                                                 &ent->dentry->d_name);
3481         } else {
3482                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3483                 if (retval == -ENOENT) {
3484                         retval = ext4_find_delete_entry(handle, ent->dir,
3485                                                         &ent->dentry->d_name);
3486                 }
3487         }
3488
3489         if (retval) {
3490                 ext4_warning(ent->dir->i_sb,
3491                                 "Deleting old file (%lu), %d, error=%d",
3492                                 ent->dir->i_ino, ent->dir->i_nlink, retval);
3493         }
3494 }
3495
3496 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3497 {
3498         if (ent->dir_nlink_delta) {
3499                 if (ent->dir_nlink_delta == -1)
3500                         ext4_dec_count(handle, ent->dir);
3501                 else
3502                         ext4_inc_count(handle, ent->dir);
3503                 ext4_mark_inode_dirty(handle, ent->dir);
3504         }
3505 }
3506
3507 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3508                                               int credits, handle_t **h)
3509 {
3510         struct inode *wh;
3511         handle_t *handle;
3512         int retries = 0;
3513
3514         /*
3515          * for inode block, sb block, group summaries,
3516          * and inode bitmap
3517          */
3518         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3519                     EXT4_XATTR_TRANS_BLOCKS + 4);
3520 retry:
3521         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3522                                          &ent->dentry->d_name, 0, NULL,
3523                                          EXT4_HT_DIR, credits);
3524
3525         handle = ext4_journal_current_handle();
3526         if (IS_ERR(wh)) {
3527                 if (handle)
3528                         ext4_journal_stop(handle);
3529                 if (PTR_ERR(wh) == -ENOSPC &&
3530                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3531                         goto retry;
3532         } else {
3533                 *h = handle;
3534                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3535                 wh->i_op = &ext4_special_inode_operations;
3536         }
3537         return wh;
3538 }
3539
3540 /*
3541  * Anybody can rename anything with this: the permission checks are left to the
3542  * higher-level routines.
3543  *
3544  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3545  * while new_{dentry,inode) refers to the destination dentry/inode
3546  * This comes from rename(const char *oldpath, const char *newpath)
3547  */
3548 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3549                        struct inode *new_dir, struct dentry *new_dentry,
3550                        unsigned int flags)
3551 {
3552         handle_t *handle = NULL;
3553         struct ext4_renament old = {
3554                 .dir = old_dir,
3555                 .dentry = old_dentry,
3556                 .inode = d_inode(old_dentry),
3557         };
3558         struct ext4_renament new = {
3559                 .dir = new_dir,
3560                 .dentry = new_dentry,
3561                 .inode = d_inode(new_dentry),
3562         };
3563         int force_reread;
3564         int retval;
3565         struct inode *whiteout = NULL;
3566         int credits;
3567         u8 old_file_type;
3568
3569         dquot_initialize(old.dir);
3570         dquot_initialize(new.dir);
3571
3572         /* Initialize quotas before so that eventual writes go
3573          * in separate transaction */
3574         if (new.inode)
3575                 dquot_initialize(new.inode);
3576
3577         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3578         if (IS_ERR(old.bh))
3579                 return PTR_ERR(old.bh);
3580         /*
3581          *  Check for inode number is _not_ due to possible IO errors.
3582          *  We might rmdir the source, keep it as pwd of some process
3583          *  and merrily kill the link to whatever was created under the
3584          *  same name. Goodbye sticky bit ;-<
3585          */
3586         retval = -ENOENT;
3587         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3588                 goto end_rename;
3589
3590         if ((old.dir != new.dir) &&
3591             ext4_encrypted_inode(new.dir) &&
3592             !ext4_is_child_context_consistent_with_parent(new.dir,
3593                                                           old.inode)) {
3594                 retval = -EPERM;
3595                 goto end_rename;
3596         }
3597
3598         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3599                                  &new.de, &new.inlined);
3600         if (IS_ERR(new.bh)) {
3601                 retval = PTR_ERR(new.bh);
3602                 new.bh = NULL;
3603                 goto end_rename;
3604         }
3605         if (new.bh) {
3606                 if (!new.inode) {
3607                         brelse(new.bh);
3608                         new.bh = NULL;
3609                 }
3610         }
3611         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3612                 ext4_alloc_da_blocks(old.inode);
3613
3614         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3615                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3616         if (!(flags & RENAME_WHITEOUT)) {
3617                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3618                 if (IS_ERR(handle)) {
3619                         retval = PTR_ERR(handle);
3620                         handle = NULL;
3621                         goto end_rename;
3622                 }
3623         } else {
3624                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3625                 if (IS_ERR(whiteout)) {
3626                         retval = PTR_ERR(whiteout);
3627                         whiteout = NULL;
3628                         goto end_rename;
3629                 }
3630         }
3631
3632         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3633                 ext4_handle_sync(handle);
3634
3635         if (S_ISDIR(old.inode->i_mode)) {
3636                 if (new.inode) {
3637                         retval = -ENOTEMPTY;
3638                         if (!ext4_empty_dir(new.inode))
3639                                 goto end_rename;
3640                 } else {
3641                         retval = -EMLINK;
3642                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3643                                 goto end_rename;
3644                 }
3645                 retval = ext4_rename_dir_prepare(handle, &old);
3646                 if (retval)
3647                         goto end_rename;
3648         }
3649         /*
3650          * If we're renaming a file within an inline_data dir and adding or
3651          * setting the new dirent causes a conversion from inline_data to
3652          * extents/blockmap, we need to force the dirent delete code to
3653          * re-read the directory, or else we end up trying to delete a dirent
3654          * from what is now the extent tree root (or a block map).
3655          */
3656         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3657                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3658
3659         old_file_type = old.de->file_type;
3660         if (whiteout) {
3661                 /*
3662                  * Do this before adding a new entry, so the old entry is sure
3663                  * to be still pointing to the valid old entry.
3664                  */
3665                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3666                                      EXT4_FT_CHRDEV);
3667                 if (retval)
3668                         goto end_rename;
3669                 ext4_mark_inode_dirty(handle, whiteout);
3670         }
3671         if (!new.bh) {
3672                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3673                 if (retval)
3674                         goto end_rename;
3675         } else {
3676                 retval = ext4_setent(handle, &new,
3677                                      old.inode->i_ino, old_file_type);
3678                 if (retval)
3679                         goto end_rename;
3680         }
3681         if (force_reread)
3682                 force_reread = !ext4_test_inode_flag(new.dir,
3683                                                      EXT4_INODE_INLINE_DATA);
3684
3685         /*
3686          * Like most other Unix systems, set the ctime for inodes on a
3687          * rename.
3688          */
3689         old.inode->i_ctime = ext4_current_time(old.inode);
3690         ext4_mark_inode_dirty(handle, old.inode);
3691
3692         if (!whiteout) {
3693                 /*
3694                  * ok, that's it
3695                  */
3696                 ext4_rename_delete(handle, &old, force_reread);
3697         }
3698
3699         if (new.inode) {
3700                 ext4_dec_count(handle, new.inode);
3701                 new.inode->i_ctime = ext4_current_time(new.inode);
3702         }
3703         old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3704         ext4_update_dx_flag(old.dir);
3705         if (old.dir_bh) {
3706                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3707                 if (retval)
3708                         goto end_rename;
3709
3710                 ext4_dec_count(handle, old.dir);
3711                 if (new.inode) {
3712                         /* checked ext4_empty_dir above, can't have another
3713                          * parent, ext4_dec_count() won't work for many-linked
3714                          * dirs */
3715                         clear_nlink(new.inode);
3716                 } else {
3717                         ext4_inc_count(handle, new.dir);
3718                         ext4_update_dx_flag(new.dir);
3719                         ext4_mark_inode_dirty(handle, new.dir);
3720                 }
3721         }
3722         ext4_mark_inode_dirty(handle, old.dir);
3723         if (new.inode) {
3724                 ext4_mark_inode_dirty(handle, new.inode);
3725                 if (!new.inode->i_nlink)
3726                         ext4_orphan_add(handle, new.inode);
3727         }
3728         retval = 0;
3729
3730 end_rename:
3731         brelse(old.dir_bh);
3732         brelse(old.bh);
3733         brelse(new.bh);
3734         if (whiteout) {
3735                 if (retval)
3736                         drop_nlink(whiteout);
3737                 unlock_new_inode(whiteout);
3738                 iput(whiteout);
3739         }
3740         if (handle)
3741                 ext4_journal_stop(handle);
3742         return retval;
3743 }
3744
3745 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3746                              struct inode *new_dir, struct dentry *new_dentry)
3747 {
3748         handle_t *handle = NULL;
3749         struct ext4_renament old = {
3750                 .dir = old_dir,
3751                 .dentry = old_dentry,
3752                 .inode = d_inode(old_dentry),
3753         };
3754         struct ext4_renament new = {
3755                 .dir = new_dir,
3756                 .dentry = new_dentry,
3757                 .inode = d_inode(new_dentry),
3758         };
3759         u8 new_file_type;
3760         int retval;
3761
3762         dquot_initialize(old.dir);
3763         dquot_initialize(new.dir);
3764
3765         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3766                                  &old.de, &old.inlined);
3767         if (IS_ERR(old.bh))
3768                 return PTR_ERR(old.bh);
3769         /*
3770          *  Check for inode number is _not_ due to possible IO errors.
3771          *  We might rmdir the source, keep it as pwd of some process
3772          *  and merrily kill the link to whatever was created under the
3773          *  same name. Goodbye sticky bit ;-<
3774          */
3775         retval = -ENOENT;
3776         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3777                 goto end_rename;
3778
3779         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3780                                  &new.de, &new.inlined);
3781         if (IS_ERR(new.bh)) {
3782                 retval = PTR_ERR(new.bh);
3783                 new.bh = NULL;
3784                 goto end_rename;
3785         }
3786
3787         /* RENAME_EXCHANGE case: old *and* new must both exist */
3788         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3789                 goto end_rename;
3790
3791         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3792                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3793                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3794         if (IS_ERR(handle)) {
3795                 retval = PTR_ERR(handle);
3796                 handle = NULL;
3797                 goto end_rename;
3798         }
3799
3800         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3801                 ext4_handle_sync(handle);
3802
3803         if (S_ISDIR(old.inode->i_mode)) {
3804                 old.is_dir = true;
3805                 retval = ext4_rename_dir_prepare(handle, &old);
3806                 if (retval)
3807                         goto end_rename;
3808         }
3809         if (S_ISDIR(new.inode->i_mode)) {
3810                 new.is_dir = true;
3811                 retval = ext4_rename_dir_prepare(handle, &new);
3812                 if (retval)
3813                         goto end_rename;
3814         }
3815
3816         /*
3817          * Other than the special case of overwriting a directory, parents'
3818          * nlink only needs to be modified if this is a cross directory rename.
3819          */
3820         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3821                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3822                 new.dir_nlink_delta = -old.dir_nlink_delta;
3823                 retval = -EMLINK;
3824                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3825                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3826                         goto end_rename;
3827         }
3828
3829         new_file_type = new.de->file_type;
3830         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3831         if (retval)
3832                 goto end_rename;
3833
3834         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3835         if (retval)
3836                 goto end_rename;
3837
3838         /*
3839          * Like most other Unix systems, set the ctime for inodes on a
3840          * rename.
3841          */
3842         old.inode->i_ctime = ext4_current_time(old.inode);
3843         new.inode->i_ctime = ext4_current_time(new.inode);
3844         ext4_mark_inode_dirty(handle, old.inode);
3845         ext4_mark_inode_dirty(handle, new.inode);
3846
3847         if (old.dir_bh) {
3848                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3849                 if (retval)
3850                         goto end_rename;
3851         }
3852         if (new.dir_bh) {
3853                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3854                 if (retval)
3855                         goto end_rename;
3856         }
3857         ext4_update_dir_count(handle, &old);
3858         ext4_update_dir_count(handle, &new);
3859         retval = 0;
3860
3861 end_rename:
3862         brelse(old.dir_bh);
3863         brelse(new.dir_bh);
3864         brelse(old.bh);
3865         brelse(new.bh);
3866         if (handle)
3867                 ext4_journal_stop(handle);
3868         return retval;
3869 }
3870
3871 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3872                         struct inode *new_dir, struct dentry *new_dentry,
3873                         unsigned int flags)
3874 {
3875         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3876                 return -EINVAL;
3877
3878         if (flags & RENAME_EXCHANGE) {
3879                 return ext4_cross_rename(old_dir, old_dentry,
3880                                          new_dir, new_dentry);
3881         }
3882
3883         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3884 }
3885
3886 /*
3887  * directories can handle most operations...
3888  */
3889 const struct inode_operations ext4_dir_inode_operations = {
3890         .create         = ext4_create,
3891         .lookup         = ext4_lookup,
3892         .link           = ext4_link,
3893         .unlink         = ext4_unlink,
3894         .symlink        = ext4_symlink,
3895         .mkdir          = ext4_mkdir,
3896         .rmdir          = ext4_rmdir,
3897         .mknod          = ext4_mknod,
3898         .tmpfile        = ext4_tmpfile,
3899         .rename2        = ext4_rename2,
3900         .setattr        = ext4_setattr,
3901         .setxattr       = generic_setxattr,
3902         .getxattr       = generic_getxattr,
3903         .listxattr      = ext4_listxattr,
3904         .removexattr    = generic_removexattr,
3905         .get_acl        = ext4_get_acl,
3906         .set_acl        = ext4_set_acl,
3907         .fiemap         = ext4_fiemap,
3908 };
3909
3910 const struct inode_operations ext4_special_inode_operations = {
3911         .setattr        = ext4_setattr,
3912         .setxattr       = generic_setxattr,
3913         .getxattr       = generic_getxattr,
3914         .listxattr      = ext4_listxattr,
3915         .removexattr    = generic_removexattr,
3916         .get_acl        = ext4_get_acl,
3917         .set_acl        = ext4_set_acl,
3918 };