linux/fs/ext4/namei.c
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   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/jbd2.h>
  30#include <linux/time.h>
  31#include <linux/fcntl.h>
  32#include <linux/stat.h>
  33#include <linux/string.h>
  34#include <linux/quotaops.h>
  35#include <linux/buffer_head.h>
  36#include <linux/bio.h>
  37#include "ext4.h"
  38#include "ext4_jbd2.h"
  39
  40#include "xattr.h"
  41#include "acl.h"
  42
  43#include <trace/events/ext4.h>
  44/*
  45 * define how far ahead to read directories while searching them.
  46 */
  47#define NAMEI_RA_CHUNKS  2
  48#define NAMEI_RA_BLOCKS  4
  49#define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  50#define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
  51
  52static struct buffer_head *ext4_append(handle_t *handle,
  53                                        struct inode *inode,
  54                                        ext4_lblk_t *block, int *err)
  55{
  56        struct buffer_head *bh;
  57
  58        if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  59                     ((inode->i_size >> 10) >=
  60                      EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) {
  61                *err = -ENOSPC;
  62                return NULL;
  63        }
  64
  65        *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  66
  67        bh = ext4_bread(handle, inode, *block, 1, err);
  68        if (bh) {
  69                inode->i_size += inode->i_sb->s_blocksize;
  70                EXT4_I(inode)->i_disksize = inode->i_size;
  71                *err = ext4_journal_get_write_access(handle, bh);
  72                if (*err) {
  73                        brelse(bh);
  74                        bh = NULL;
  75                }
  76        }
  77        if (!bh && !(*err)) {
  78                *err = -EIO;
  79                ext4_error(inode->i_sb,
  80                           "Directory hole detected on inode %lu\n",
  81                           inode->i_ino);
  82        }
  83        return bh;
  84}
  85
  86#ifndef assert
  87#define assert(test) J_ASSERT(test)
  88#endif
  89
  90#ifdef DX_DEBUG
  91#define dxtrace(command) command
  92#else
  93#define dxtrace(command)
  94#endif
  95
  96struct fake_dirent
  97{
  98        __le32 inode;
  99        __le16 rec_len;
 100        u8 name_len;
 101        u8 file_type;
 102};
 103
 104struct dx_countlimit
 105{
 106        __le16 limit;
 107        __le16 count;
 108};
 109
 110struct dx_entry
 111{
 112        __le32 hash;
 113        __le32 block;
 114};
 115
 116/*
 117 * dx_root_info is laid out so that if it should somehow get overlaid by a
 118 * dirent the two low bits of the hash version will be zero.  Therefore, the
 119 * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 120 */
 121
 122struct dx_root
 123{
 124        struct fake_dirent dot;
 125        char dot_name[4];
 126        struct fake_dirent dotdot;
 127        char dotdot_name[4];
 128        struct dx_root_info
 129        {
 130                __le32 reserved_zero;
 131                u8 hash_version;
 132                u8 info_length; /* 8 */
 133                u8 indirect_levels;
 134                u8 unused_flags;
 135        }
 136        info;
 137        struct dx_entry entries[0];
 138};
 139
 140struct dx_node
 141{
 142        struct fake_dirent fake;
 143        struct dx_entry entries[0];
 144};
 145
 146
 147struct dx_frame
 148{
 149        struct buffer_head *bh;
 150        struct dx_entry *entries;
 151        struct dx_entry *at;
 152};
 153
 154struct dx_map_entry
 155{
 156        u32 hash;
 157        u16 offs;
 158        u16 size;
 159};
 160
 161/*
 162 * This goes at the end of each htree block.
 163 */
 164struct dx_tail {
 165        u32 dt_reserved;
 166        __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 167};
 168
 169static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 170static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 171static inline unsigned dx_get_hash(struct dx_entry *entry);
 172static void dx_set_hash(struct dx_entry *entry, unsigned value);
 173static unsigned dx_get_count(struct dx_entry *entries);
 174static unsigned dx_get_limit(struct dx_entry *entries);
 175static void dx_set_count(struct dx_entry *entries, unsigned value);
 176static void dx_set_limit(struct dx_entry *entries, unsigned value);
 177static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 178static unsigned dx_node_limit(struct inode *dir);
 179static struct dx_frame *dx_probe(const struct qstr *d_name,
 180                                 struct inode *dir,
 181                                 struct dx_hash_info *hinfo,
 182                                 struct dx_frame *frame,
 183                                 int *err);
 184static void dx_release(struct dx_frame *frames);
 185static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 186                       struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 187static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 188static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 189                struct dx_map_entry *offsets, int count, unsigned blocksize);
 190static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 191static void dx_insert_block(struct dx_frame *frame,
 192                                        u32 hash, ext4_lblk_t block);
 193static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 194                                 struct dx_frame *frame,
 195                                 struct dx_frame *frames,
 196                                 __u32 *start_hash);
 197static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 198                const struct qstr *d_name,
 199                struct ext4_dir_entry_2 **res_dir,
 200                int *err);
 201static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 202                             struct inode *inode);
 203
 204/* checksumming functions */
 205#define EXT4_DIRENT_TAIL(block, blocksize) \
 206        ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
 207                                        ((blocksize) - \
 208                                         sizeof(struct ext4_dir_entry_tail))))
 209
 210static void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 211                                   unsigned int blocksize)
 212{
 213        memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 214        t->det_rec_len = ext4_rec_len_to_disk(
 215                        sizeof(struct ext4_dir_entry_tail), blocksize);
 216        t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 217}
 218
 219/* Walk through a dirent block to find a checksum "dirent" at the tail */
 220static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 221                                                   struct ext4_dir_entry *de)
 222{
 223        struct ext4_dir_entry_tail *t;
 224
 225#ifdef PARANOID
 226        struct ext4_dir_entry *d, *top;
 227
 228        d = de;
 229        top = (struct ext4_dir_entry *)(((void *)de) +
 230                (EXT4_BLOCK_SIZE(inode->i_sb) -
 231                sizeof(struct ext4_dir_entry_tail)));
 232        while (d < top && d->rec_len)
 233                d = (struct ext4_dir_entry *)(((void *)d) +
 234                    le16_to_cpu(d->rec_len));
 235
 236        if (d != top)
 237                return NULL;
 238
 239        t = (struct ext4_dir_entry_tail *)d;
 240#else
 241        t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 242#endif
 243
 244        if (t->det_reserved_zero1 ||
 245            le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 246            t->det_reserved_zero2 ||
 247            t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 248                return NULL;
 249
 250        return t;
 251}
 252
 253static __le32 ext4_dirent_csum(struct inode *inode,
 254                               struct ext4_dir_entry *dirent, int size)
 255{
 256        struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 257        struct ext4_inode_info *ei = EXT4_I(inode);
 258        __u32 csum;
 259
 260        csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 261        return cpu_to_le32(csum);
 262}
 263
 264int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 265{
 266        struct ext4_dir_entry_tail *t;
 267
 268        if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 269                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 270                return 1;
 271
 272        t = get_dirent_tail(inode, dirent);
 273        if (!t) {
 274                EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
 275                                 "leaf for checksum.  Please run e2fsck -D.");
 276                return 0;
 277        }
 278
 279        if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 280                                                (void *)t - (void *)dirent))
 281                return 0;
 282
 283        return 1;
 284}
 285
 286static void ext4_dirent_csum_set(struct inode *inode,
 287                                 struct ext4_dir_entry *dirent)
 288{
 289        struct ext4_dir_entry_tail *t;
 290
 291        if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 292                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 293                return;
 294
 295        t = get_dirent_tail(inode, dirent);
 296        if (!t) {
 297                EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
 298                                 "leaf for checksum.  Please run e2fsck -D.");
 299                return;
 300        }
 301
 302        t->det_checksum = ext4_dirent_csum(inode, dirent,
 303                                           (void *)t - (void *)dirent);
 304}
 305
 306static inline int ext4_handle_dirty_dirent_node(handle_t *handle,
 307                                                struct inode *inode,
 308                                                struct buffer_head *bh)
 309{
 310        ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 311        return ext4_handle_dirty_metadata(handle, inode, bh);
 312}
 313
 314static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 315                                               struct ext4_dir_entry *dirent,
 316                                               int *offset)
 317{
 318        struct ext4_dir_entry *dp;
 319        struct dx_root_info *root;
 320        int count_offset;
 321
 322        if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 323                count_offset = 8;
 324        else if (le16_to_cpu(dirent->rec_len) == 12) {
 325                dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 326                if (le16_to_cpu(dp->rec_len) !=
 327                    EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 328                        return NULL;
 329                root = (struct dx_root_info *)(((void *)dp + 12));
 330                if (root->reserved_zero ||
 331                    root->info_length != sizeof(struct dx_root_info))
 332                        return NULL;
 333                count_offset = 32;
 334        } else
 335                return NULL;
 336
 337        if (offset)
 338                *offset = count_offset;
 339        return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 340}
 341
 342static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 343                           int count_offset, int count, struct dx_tail *t)
 344{
 345        struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 346        struct ext4_inode_info *ei = EXT4_I(inode);
 347        __u32 csum, old_csum;
 348        int size;
 349
 350        size = count_offset + (count * sizeof(struct dx_entry));
 351        old_csum = t->dt_checksum;
 352        t->dt_checksum = 0;
 353        csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 354        csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
 355        t->dt_checksum = old_csum;
 356
 357        return cpu_to_le32(csum);
 358}
 359
 360static int ext4_dx_csum_verify(struct inode *inode,
 361                               struct ext4_dir_entry *dirent)
 362{
 363        struct dx_countlimit *c;
 364        struct dx_tail *t;
 365        int count_offset, limit, count;
 366
 367        if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 368                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 369                return 1;
 370
 371        c = get_dx_countlimit(inode, dirent, &count_offset);
 372        if (!c) {
 373                EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 374                return 1;
 375        }
 376        limit = le16_to_cpu(c->limit);
 377        count = le16_to_cpu(c->count);
 378        if (count_offset + (limit * sizeof(struct dx_entry)) >
 379            EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 380                EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
 381                                 "tree checksum found.  Run e2fsck -D.");
 382                return 1;
 383        }
 384        t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 385
 386        if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 387                                            count, t))
 388                return 0;
 389        return 1;
 390}
 391
 392static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 393{
 394        struct dx_countlimit *c;
 395        struct dx_tail *t;
 396        int count_offset, limit, count;
 397
 398        if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 399                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 400                return;
 401
 402        c = get_dx_countlimit(inode, dirent, &count_offset);
 403        if (!c) {
 404                EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 405                return;
 406        }
 407        limit = le16_to_cpu(c->limit);
 408        count = le16_to_cpu(c->count);
 409        if (count_offset + (limit * sizeof(struct dx_entry)) >
 410            EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 411                EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
 412                                 "tree checksum.  Run e2fsck -D.");
 413                return;
 414        }
 415        t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 416
 417        t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 418}
 419
 420static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 421                                            struct inode *inode,
 422                                            struct buffer_head *bh)
 423{
 424        ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 425        return ext4_handle_dirty_metadata(handle, inode, bh);
 426}
 427
 428/*
 429 * p is at least 6 bytes before the end of page
 430 */
 431static inline struct ext4_dir_entry_2 *
 432ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 433{
 434        return (struct ext4_dir_entry_2 *)((char *)p +
 435                ext4_rec_len_from_disk(p->rec_len, blocksize));
 436}
 437
 438/*
 439 * Future: use high four bits of block for coalesce-on-delete flags
 440 * Mask them off for now.
 441 */
 442
 443static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 444{
 445        return le32_to_cpu(entry->block) & 0x00ffffff;
 446}
 447
 448static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 449{
 450        entry->block = cpu_to_le32(value);
 451}
 452
 453static inline unsigned dx_get_hash(struct dx_entry *entry)
 454{
 455        return le32_to_cpu(entry->hash);
 456}
 457
 458static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 459{
 460        entry->hash = cpu_to_le32(value);
 461}
 462
 463static inline unsigned dx_get_count(struct dx_entry *entries)
 464{
 465        return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 466}
 467
 468static inline unsigned dx_get_limit(struct dx_entry *entries)
 469{
 470        return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 471}
 472
 473static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 474{
 475        ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 476}
 477
 478static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 479{
 480        ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 481}
 482
 483static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 484{
 485        unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 486                EXT4_DIR_REC_LEN(2) - infosize;
 487
 488        if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 489                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 490                entry_space -= sizeof(struct dx_tail);
 491        return entry_space / sizeof(struct dx_entry);
 492}
 493
 494static inline unsigned dx_node_limit(struct inode *dir)
 495{
 496        unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 497
 498        if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 499                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 500                entry_space -= sizeof(struct dx_tail);
 501        return entry_space / sizeof(struct dx_entry);
 502}
 503
 504/*
 505 * Debug
 506 */
 507#ifdef DX_DEBUG
 508static void dx_show_index(char * label, struct dx_entry *entries)
 509{
 510        int i, n = dx_get_count (entries);
 511        printk(KERN_DEBUG "%s index ", label);
 512        for (i = 0; i < n; i++) {
 513                printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 514                                0, (unsigned long)dx_get_block(entries + i));
 515        }
 516        printk("\n");
 517}
 518
 519struct stats
 520{
 521        unsigned names;
 522        unsigned space;
 523        unsigned bcount;
 524};
 525
 526static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
 527                                 int size, int show_names)
 528{
 529        unsigned names = 0, space = 0;
 530        char *base = (char *) de;
 531        struct dx_hash_info h = *hinfo;
 532
 533        printk("names: ");
 534        while ((char *) de < base + size)
 535        {
 536                if (de->inode)
 537                {
 538                        if (show_names)
 539                        {
 540                                int len = de->name_len;
 541                                char *name = de->name;
 542                                while (len--) printk("%c", *name++);
 543                                ext4fs_dirhash(de->name, de->name_len, &h);
 544                                printk(":%x.%u ", h.hash,
 545                                       (unsigned) ((char *) de - base));
 546                        }
 547                        space += EXT4_DIR_REC_LEN(de->name_len);
 548                        names++;
 549                }
 550                de = ext4_next_entry(de, size);
 551        }
 552        printk("(%i)\n", names);
 553        return (struct stats) { names, space, 1 };
 554}
 555
 556struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 557                             struct dx_entry *entries, int levels)
 558{
 559        unsigned blocksize = dir->i_sb->s_blocksize;
 560        unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 561        unsigned bcount = 0;
 562        struct buffer_head *bh;
 563        int err;
 564        printk("%i indexed blocks...\n", count);
 565        for (i = 0; i < count; i++, entries++)
 566        {
 567                ext4_lblk_t block = dx_get_block(entries);
 568                ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 569                u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 570                struct stats stats;
 571                printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 572                if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
 573                stats = levels?
 574                   dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 575                   dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
 576                names += stats.names;
 577                space += stats.space;
 578                bcount += stats.bcount;
 579                brelse(bh);
 580        }
 581        if (bcount)
 582                printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 583                       levels ? "" : "   ", names, space/bcount,
 584                       (space/bcount)*100/blocksize);
 585        return (struct stats) { names, space, bcount};
 586}
 587#endif /* DX_DEBUG */
 588
 589/*
 590 * Probe for a directory leaf block to search.
 591 *
 592 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 593 * error in the directory index, and the caller should fall back to
 594 * searching the directory normally.  The callers of dx_probe **MUST**
 595 * check for this error code, and make sure it never gets reflected
 596 * back to userspace.
 597 */
 598static struct dx_frame *
 599dx_probe(const struct qstr *d_name, struct inode *dir,
 600         struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
 601{
 602        unsigned count, indirect;
 603        struct dx_entry *at, *entries, *p, *q, *m;
 604        struct dx_root *root;
 605        struct buffer_head *bh;
 606        struct dx_frame *frame = frame_in;
 607        u32 hash;
 608
 609        frame->bh = NULL;
 610        if (!(bh = ext4_bread(NULL, dir, 0, 0, err))) {
 611                if (*err == 0)
 612                        *err = ERR_BAD_DX_DIR;
 613                goto fail;
 614        }
 615        root = (struct dx_root *) bh->b_data;
 616        if (root->info.hash_version != DX_HASH_TEA &&
 617            root->info.hash_version != DX_HASH_HALF_MD4 &&
 618            root->info.hash_version != DX_HASH_LEGACY) {
 619                ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
 620                             root->info.hash_version);
 621                brelse(bh);
 622                *err = ERR_BAD_DX_DIR;
 623                goto fail;
 624        }
 625        hinfo->hash_version = root->info.hash_version;
 626        if (hinfo->hash_version <= DX_HASH_TEA)
 627                hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 628        hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 629        if (d_name)
 630                ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 631        hash = hinfo->hash;
 632
 633        if (root->info.unused_flags & 1) {
 634                ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
 635                             root->info.unused_flags);
 636                brelse(bh);
 637                *err = ERR_BAD_DX_DIR;
 638                goto fail;
 639        }
 640
 641        if ((indirect = root->info.indirect_levels) > 1) {
 642                ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 643                             root->info.indirect_levels);
 644                brelse(bh);
 645                *err = ERR_BAD_DX_DIR;
 646                goto fail;
 647        }
 648
 649        if (!buffer_verified(bh) &&
 650            !ext4_dx_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) {
 651                ext4_warning(dir->i_sb, "Root failed checksum");
 652                brelse(bh);
 653                *err = ERR_BAD_DX_DIR;
 654                goto fail;
 655        }
 656        set_buffer_verified(bh);
 657
 658        entries = (struct dx_entry *) (((char *)&root->info) +
 659                                       root->info.info_length);
 660
 661        if (dx_get_limit(entries) != dx_root_limit(dir,
 662                                                   root->info.info_length)) {
 663                ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 664                brelse(bh);
 665                *err = ERR_BAD_DX_DIR;
 666                goto fail;
 667        }
 668
 669        dxtrace(printk("Look up %x", hash));
 670        while (1)
 671        {
 672                count = dx_get_count(entries);
 673                if (!count || count > dx_get_limit(entries)) {
 674                        ext4_warning(dir->i_sb,
 675                                     "dx entry: no count or count > limit");
 676                        brelse(bh);
 677                        *err = ERR_BAD_DX_DIR;
 678                        goto fail2;
 679                }
 680
 681                p = entries + 1;
 682                q = entries + count - 1;
 683                while (p <= q)
 684                {
 685                        m = p + (q - p)/2;
 686                        dxtrace(printk("."));
 687                        if (dx_get_hash(m) > hash)
 688                                q = m - 1;
 689                        else
 690                                p = m + 1;
 691                }
 692
 693                if (0) // linear search cross check
 694                {
 695                        unsigned n = count - 1;
 696                        at = entries;
 697                        while (n--)
 698                        {
 699                                dxtrace(printk(","));
 700                                if (dx_get_hash(++at) > hash)
 701                                {
 702                                        at--;
 703                                        break;
 704                                }
 705                        }
 706                        assert (at == p - 1);
 707                }
 708
 709                at = p - 1;
 710                dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 711                frame->bh = bh;
 712                frame->entries = entries;
 713                frame->at = at;
 714                if (!indirect--) return frame;
 715                if (!(bh = ext4_bread(NULL, dir, dx_get_block(at), 0, err))) {
 716                        if (!(*err))
 717                                *err = ERR_BAD_DX_DIR;
 718                        goto fail2;
 719                }
 720                at = entries = ((struct dx_node *) bh->b_data)->entries;
 721
 722                if (!buffer_verified(bh) &&
 723                    !ext4_dx_csum_verify(dir,
 724                                         (struct ext4_dir_entry *)bh->b_data)) {
 725                        ext4_warning(dir->i_sb, "Node failed checksum");
 726                        brelse(bh);
 727                        *err = ERR_BAD_DX_DIR;
 728                        goto fail;
 729                }
 730                set_buffer_verified(bh);
 731
 732                if (dx_get_limit(entries) != dx_node_limit (dir)) {
 733                        ext4_warning(dir->i_sb,
 734                                     "dx entry: limit != node limit");
 735                        brelse(bh);
 736                        *err = ERR_BAD_DX_DIR;
 737                        goto fail2;
 738                }
 739                frame++;
 740                frame->bh = NULL;
 741        }
 742fail2:
 743        while (frame >= frame_in) {
 744                brelse(frame->bh);
 745                frame--;
 746        }
 747fail:
 748        if (*err == ERR_BAD_DX_DIR)
 749                ext4_warning(dir->i_sb,
 750                             "Corrupt dir inode %lu, running e2fsck is "
 751                             "recommended.", dir->i_ino);
 752        return NULL;
 753}
 754
 755static void dx_release (struct dx_frame *frames)
 756{
 757        if (frames[0].bh == NULL)
 758                return;
 759
 760        if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 761                brelse(frames[1].bh);
 762        brelse(frames[0].bh);
 763}
 764
 765/*
 766 * This function increments the frame pointer to search the next leaf
 767 * block, and reads in the necessary intervening nodes if the search
 768 * should be necessary.  Whether or not the search is necessary is
 769 * controlled by the hash parameter.  If the hash value is even, then
 770 * the search is only continued if the next block starts with that
 771 * hash value.  This is used if we are searching for a specific file.
 772 *
 773 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 774 *
 775 * This function returns 1 if the caller should continue to search,
 776 * or 0 if it should not.  If there is an error reading one of the
 777 * index blocks, it will a negative error code.
 778 *
 779 * If start_hash is non-null, it will be filled in with the starting
 780 * hash of the next page.
 781 */
 782static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 783                                 struct dx_frame *frame,
 784                                 struct dx_frame *frames,
 785                                 __u32 *start_hash)
 786{
 787        struct dx_frame *p;
 788        struct buffer_head *bh;
 789        int err, num_frames = 0;
 790        __u32 bhash;
 791
 792        p = frame;
 793        /*
 794         * Find the next leaf page by incrementing the frame pointer.
 795         * If we run out of entries in the interior node, loop around and
 796         * increment pointer in the parent node.  When we break out of
 797         * this loop, num_frames indicates the number of interior
 798         * nodes need to be read.
 799         */
 800        while (1) {
 801                if (++(p->at) < p->entries + dx_get_count(p->entries))
 802                        break;
 803                if (p == frames)
 804                        return 0;
 805                num_frames++;
 806                p--;
 807        }
 808
 809        /*
 810         * If the hash is 1, then continue only if the next page has a
 811         * continuation hash of any value.  This is used for readdir
 812         * handling.  Otherwise, check to see if the hash matches the
 813         * desired contiuation hash.  If it doesn't, return since
 814         * there's no point to read in the successive index pages.
 815         */
 816        bhash = dx_get_hash(p->at);
 817        if (start_hash)
 818                *start_hash = bhash;
 819        if ((hash & 1) == 0) {
 820                if ((bhash & ~1) != hash)
 821                        return 0;
 822        }
 823        /*
 824         * If the hash is HASH_NB_ALWAYS, we always go to the next
 825         * block so no check is necessary
 826         */
 827        while (num_frames--) {
 828                if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
 829                                      0, &err))) {
 830                        if (!err) {
 831                                ext4_error(dir->i_sb,
 832                                           "Directory hole detected on inode %lu\n",
 833                                           dir->i_ino);
 834                                return -EIO;
 835                        }
 836                        return err; /* Failure */
 837                }
 838
 839                if (!buffer_verified(bh) &&
 840                    !ext4_dx_csum_verify(dir,
 841                                         (struct ext4_dir_entry *)bh->b_data)) {
 842                        ext4_warning(dir->i_sb, "Node failed checksum");
 843                        return -EIO;
 844                }
 845                set_buffer_verified(bh);
 846
 847                p++;
 848                brelse(p->bh);
 849                p->bh = bh;
 850                p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 851        }
 852        return 1;
 853}
 854
 855
 856/*
 857 * This function fills a red-black tree with information from a
 858 * directory block.  It returns the number directory entries loaded
 859 * into the tree.  If there is an error it is returned in err.
 860 */
 861static int htree_dirblock_to_tree(struct file *dir_file,
 862                                  struct inode *dir, ext4_lblk_t block,
 863                                  struct dx_hash_info *hinfo,
 864                                  __u32 start_hash, __u32 start_minor_hash)
 865{
 866        struct buffer_head *bh;
 867        struct ext4_dir_entry_2 *de, *top;
 868        int err = 0, count = 0;
 869
 870        dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 871                                                        (unsigned long)block));
 872        if (!(bh = ext4_bread(NULL, dir, block, 0, &err))) {
 873                if (!err) {
 874                        err = -EIO;
 875                        ext4_error(dir->i_sb,
 876                                   "Directory hole detected on inode %lu\n",
 877                                   dir->i_ino);
 878                }
 879                return err;
 880        }
 881
 882        if (!buffer_verified(bh) &&
 883            !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
 884                return -EIO;
 885        set_buffer_verified(bh);
 886
 887        de = (struct ext4_dir_entry_2 *) bh->b_data;
 888        top = (struct ext4_dir_entry_2 *) ((char *) de +
 889                                           dir->i_sb->s_blocksize -
 890                                           EXT4_DIR_REC_LEN(0));
 891        for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 892                if (ext4_check_dir_entry(dir, NULL, de, bh,
 893                                (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 894                                         + ((char *)de - bh->b_data))) {
 895                        /* On error, skip the f_pos to the next block. */
 896                        dir_file->f_pos = (dir_file->f_pos |
 897                                        (dir->i_sb->s_blocksize - 1)) + 1;
 898                        brelse(bh);
 899                        return count;
 900                }
 901                ext4fs_dirhash(de->name, de->name_len, hinfo);
 902                if ((hinfo->hash < start_hash) ||
 903                    ((hinfo->hash == start_hash) &&
 904                     (hinfo->minor_hash < start_minor_hash)))
 905                        continue;
 906                if (de->inode == 0)
 907                        continue;
 908                if ((err = ext4_htree_store_dirent(dir_file,
 909                                   hinfo->hash, hinfo->minor_hash, de)) != 0) {
 910                        brelse(bh);
 911                        return err;
 912                }
 913                count++;
 914        }
 915        brelse(bh);
 916        return count;
 917}
 918
 919
 920/*
 921 * This function fills a red-black tree with information from a
 922 * directory.  We start scanning the directory in hash order, starting
 923 * at start_hash and start_minor_hash.
 924 *
 925 * This function returns the number of entries inserted into the tree,
 926 * or a negative error code.
 927 */
 928int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 929                         __u32 start_minor_hash, __u32 *next_hash)
 930{
 931        struct dx_hash_info hinfo;
 932        struct ext4_dir_entry_2 *de;
 933        struct dx_frame frames[2], *frame;
 934        struct inode *dir;
 935        ext4_lblk_t block;
 936        int count = 0;
 937        int ret, err;
 938        __u32 hashval;
 939
 940        dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 941                       start_hash, start_minor_hash));
 942        dir = dir_file->f_path.dentry->d_inode;
 943        if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
 944                hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 945                if (hinfo.hash_version <= DX_HASH_TEA)
 946                        hinfo.hash_version +=
 947                                EXT4_SB(dir->i_sb)->s_hash_unsigned;
 948                hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 949                count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
 950                                               start_hash, start_minor_hash);
 951                *next_hash = ~0;
 952                return count;
 953        }
 954        hinfo.hash = start_hash;
 955        hinfo.minor_hash = 0;
 956        frame = dx_probe(NULL, dir, &hinfo, frames, &err);
 957        if (!frame)
 958                return err;
 959
 960        /* Add '.' and '..' from the htree header */
 961        if (!start_hash && !start_minor_hash) {
 962                de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 963                if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 964                        goto errout;
 965                count++;
 966        }
 967        if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
 968                de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 969                de = ext4_next_entry(de, dir->i_sb->s_blocksize);
 970                if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
 971                        goto errout;
 972                count++;
 973        }
 974
 975        while (1) {
 976                block = dx_get_block(frame->at);
 977                ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
 978                                             start_hash, start_minor_hash);
 979                if (ret < 0) {
 980                        err = ret;
 981                        goto errout;
 982                }
 983                count += ret;
 984                hashval = ~0;
 985                ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
 986                                            frame, frames, &hashval);
 987                *next_hash = hashval;
 988                if (ret < 0) {
 989                        err = ret;
 990                        goto errout;
 991                }
 992                /*
 993                 * Stop if:  (a) there are no more entries, or
 994                 * (b) we have inserted at least one entry and the
 995                 * next hash value is not a continuation
 996                 */
 997                if ((ret == 0) ||
 998                    (count && ((hashval & 1) == 0)))
 999                        break;
1000        }
1001        dx_release(frames);
1002        dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1003                       "next hash: %x\n", count, *next_hash));
1004        return count;
1005errout:
1006        dx_release(frames);
1007        return (err);
1008}
1009
1010
1011/*
1012 * Directory block splitting, compacting
1013 */
1014
1015/*
1016 * Create map of hash values, offsets, and sizes, stored at end of block.
1017 * Returns number of entries mapped.
1018 */
1019static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
1020                       struct dx_hash_info *hinfo,
1021                       struct dx_map_entry *map_tail)
1022{
1023        int count = 0;
1024        char *base = (char *) de;
1025        struct dx_hash_info h = *hinfo;
1026
1027        while ((char *) de < base + blocksize) {
1028                if (de->name_len && de->inode) {
1029                        ext4fs_dirhash(de->name, de->name_len, &h);
1030                        map_tail--;
1031                        map_tail->hash = h.hash;
1032                        map_tail->offs = ((char *) de - base)>>2;
1033                        map_tail->size = le16_to_cpu(de->rec_len);
1034                        count++;
1035                        cond_resched();
1036                }
1037                /* XXX: do we need to check rec_len == 0 case? -Chris */
1038                de = ext4_next_entry(de, blocksize);
1039        }
1040        return count;
1041}
1042
1043/* Sort map by hash value */
1044static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1045{
1046        struct dx_map_entry *p, *q, *top = map + count - 1;
1047        int more;
1048        /* Combsort until bubble sort doesn't suck */
1049        while (count > 2) {
1050                count = count*10/13;
1051                if (count - 9 < 2) /* 9, 10 -> 11 */
1052                        count = 11;
1053                for (p = top, q = p - count; q >= map; p--, q--)
1054                        if (p->hash < q->hash)
1055                                swap(*p, *q);
1056        }
1057        /* Garden variety bubble sort */
1058        do {
1059                more = 0;
1060                q = top;
1061                while (q-- > map) {
1062                        if (q[1].hash >= q[0].hash)
1063                                continue;
1064                        swap(*(q+1), *q);
1065                        more = 1;
1066                }
1067        } while(more);
1068}
1069
1070static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1071{
1072        struct dx_entry *entries = frame->entries;
1073        struct dx_entry *old = frame->at, *new = old + 1;
1074        int count = dx_get_count(entries);
1075
1076        assert(count < dx_get_limit(entries));
1077        assert(old < entries + count);
1078        memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1079        dx_set_hash(new, hash);
1080        dx_set_block(new, block);
1081        dx_set_count(entries, count + 1);
1082}
1083
1084static void ext4_update_dx_flag(struct inode *inode)
1085{
1086        if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
1087                                     EXT4_FEATURE_COMPAT_DIR_INDEX))
1088                ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
1089}
1090
1091/*
1092 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1093 *
1094 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1095 * `de != NULL' is guaranteed by caller.
1096 */
1097static inline int ext4_match (int len, const char * const name,
1098                              struct ext4_dir_entry_2 * de)
1099{
1100        if (len != de->name_len)
1101                return 0;
1102        if (!de->inode)
1103                return 0;
1104        return !memcmp(name, de->name, len);
1105}
1106
1107/*
1108 * Returns 0 if not found, -1 on failure, and 1 on success
1109 */
1110static inline int search_dirblock(struct buffer_head *bh,
1111                                  struct inode *dir,
1112                                  const struct qstr *d_name,
1113                                  unsigned int offset,
1114                                  struct ext4_dir_entry_2 ** res_dir)
1115{
1116        struct ext4_dir_entry_2 * de;
1117        char * dlimit;
1118        int de_len;
1119        const char *name = d_name->name;
1120        int namelen = d_name->len;
1121
1122        de = (struct ext4_dir_entry_2 *) bh->b_data;
1123        dlimit = bh->b_data + dir->i_sb->s_blocksize;
1124        while ((char *) de < dlimit) {
1125                /* this code is executed quadratically often */
1126                /* do minimal checking `by hand' */
1127
1128                if ((char *) de + namelen <= dlimit &&
1129                    ext4_match (namelen, name, de)) {
1130                        /* found a match - just to be sure, do a full check */
1131                        if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1132                                return -1;
1133                        *res_dir = de;
1134                        return 1;
1135                }
1136                /* prevent looping on a bad block */
1137                de_len = ext4_rec_len_from_disk(de->rec_len,
1138                                                dir->i_sb->s_blocksize);
1139                if (de_len <= 0)
1140                        return -1;
1141                offset += de_len;
1142                de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1143        }
1144        return 0;
1145}
1146
1147
1148/*
1149 *      ext4_find_entry()
1150 *
1151 * finds an entry in the specified directory with the wanted name. It
1152 * returns the cache buffer in which the entry was found, and the entry
1153 * itself (as a parameter - res_dir). It does NOT read the inode of the
1154 * entry - you'll have to do that yourself if you want to.
1155 *
1156 * The returned buffer_head has ->b_count elevated.  The caller is expected
1157 * to brelse() it when appropriate.
1158 */
1159static struct buffer_head * ext4_find_entry (struct inode *dir,
1160                                        const struct qstr *d_name,
1161                                        struct ext4_dir_entry_2 ** res_dir)
1162{
1163        struct super_block *sb;
1164        struct buffer_head *bh_use[NAMEI_RA_SIZE];
1165        struct buffer_head *bh, *ret = NULL;
1166        ext4_lblk_t start, block, b;
1167        const u8 *name = d_name->name;
1168        int ra_max = 0;         /* Number of bh's in the readahead
1169                                   buffer, bh_use[] */
1170        int ra_ptr = 0;         /* Current index into readahead
1171                                   buffer */
1172        int num = 0;
1173        ext4_lblk_t  nblocks;
1174        int i, err;
1175        int namelen;
1176
1177        *res_dir = NULL;
1178        sb = dir->i_sb;
1179        namelen = d_name->len;
1180        if (namelen > EXT4_NAME_LEN)
1181                return NULL;
1182        if ((namelen <= 2) && (name[0] == '.') &&
1183            (name[1] == '.' || name[1] == '\0')) {
1184                /*
1185                 * "." or ".." will only be in the first block
1186                 * NFS may look up ".."; "." should be handled by the VFS
1187                 */
1188                block = start = 0;
1189                nblocks = 1;
1190                goto restart;
1191        }
1192        if (is_dx(dir)) {
1193                bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
1194                /*
1195                 * On success, or if the error was file not found,
1196                 * return.  Otherwise, fall back to doing a search the
1197                 * old fashioned way.
1198                 */
1199                if (bh || (err != ERR_BAD_DX_DIR))
1200                        return bh;
1201                dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1202                               "falling back\n"));
1203        }
1204        nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1205        start = EXT4_I(dir)->i_dir_start_lookup;
1206        if (start >= nblocks)
1207                start = 0;
1208        block = start;
1209restart:
1210        do {
1211                /*
1212                 * We deal with the read-ahead logic here.
1213                 */
1214                if (ra_ptr >= ra_max) {
1215                        /* Refill the readahead buffer */
1216                        ra_ptr = 0;
1217                        b = block;
1218                        for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1219                                /*
1220                                 * Terminate if we reach the end of the
1221                                 * directory and must wrap, or if our
1222                                 * search has finished at this block.
1223                                 */
1224                                if (b >= nblocks || (num && block == start)) {
1225                                        bh_use[ra_max] = NULL;
1226                                        break;
1227                                }
1228                                num++;
1229                                bh = ext4_getblk(NULL, dir, b++, 0, &err);
1230                                bh_use[ra_max] = bh;
1231                                if (bh)
1232                                        ll_rw_block(READ | REQ_META | REQ_PRIO,
1233                                                    1, &bh);
1234                        }
1235                }
1236                if ((bh = bh_use[ra_ptr++]) == NULL)
1237                        goto next;
1238                wait_on_buffer(bh);
1239                if (!buffer_uptodate(bh)) {
1240                        /* read error, skip block & hope for the best */
1241                        EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1242                                         (unsigned long) block);
1243                        brelse(bh);
1244                        goto next;
1245                }
1246                if (!buffer_verified(bh) &&
1247                    !ext4_dirent_csum_verify(dir,
1248                                (struct ext4_dir_entry *)bh->b_data)) {
1249                        EXT4_ERROR_INODE(dir, "checksumming directory "
1250                                         "block %lu", (unsigned long)block);
1251                        brelse(bh);
1252                        goto next;
1253                }
1254                set_buffer_verified(bh);
1255                i = search_dirblock(bh, dir, d_name,
1256                            block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1257                if (i == 1) {
1258                        EXT4_I(dir)->i_dir_start_lookup = block;
1259                        ret = bh;
1260                        goto cleanup_and_exit;
1261                } else {
1262                        brelse(bh);
1263                        if (i < 0)
1264                                goto cleanup_and_exit;
1265                }
1266        next:
1267                if (++block >= nblocks)
1268                        block = 0;
1269        } while (block != start);
1270
1271        /*
1272         * If the directory has grown while we were searching, then
1273         * search the last part of the directory before giving up.
1274         */
1275        block = nblocks;
1276        nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1277        if (block < nblocks) {
1278                start = 0;
1279                goto restart;
1280        }
1281
1282cleanup_and_exit:
1283        /* Clean up the read-ahead blocks */
1284        for (; ra_ptr < ra_max; ra_ptr++)
1285                brelse(bh_use[ra_ptr]);
1286        return ret;
1287}
1288
1289static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1290                       struct ext4_dir_entry_2 **res_dir, int *err)
1291{
1292        struct super_block * sb = dir->i_sb;
1293        struct dx_hash_info     hinfo;
1294        struct dx_frame frames[2], *frame;
1295        struct buffer_head *bh;
1296        ext4_lblk_t block;
1297        int retval;
1298
1299        if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1300                return NULL;
1301        do {
1302                block = dx_get_block(frame->at);
1303                if (!(bh = ext4_bread(NULL, dir, block, 0, err))) {
1304                        if (!(*err)) {
1305                                *err = -EIO;
1306                                ext4_error(dir->i_sb,
1307                                           "Directory hole detected on inode %lu\n",
1308                                           dir->i_ino);
1309                        }
1310                        goto errout;
1311                }
1312
1313                if (!buffer_verified(bh) &&
1314                    !ext4_dirent_csum_verify(dir,
1315                                (struct ext4_dir_entry *)bh->b_data)) {
1316                        EXT4_ERROR_INODE(dir, "checksumming directory "
1317                                         "block %lu", (unsigned long)block);
1318                        brelse(bh);
1319                        *err = -EIO;
1320                        goto errout;
1321                }
1322                set_buffer_verified(bh);
1323                retval = search_dirblock(bh, dir, d_name,
1324                                         block << EXT4_BLOCK_SIZE_BITS(sb),
1325                                         res_dir);
1326                if (retval == 1) {      /* Success! */
1327                        dx_release(frames);
1328                        return bh;
1329                }
1330                brelse(bh);
1331                if (retval == -1) {
1332                        *err = ERR_BAD_DX_DIR;
1333                        goto errout;
1334                }
1335
1336                /* Check to see if we should continue to search */
1337                retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1338                                               frames, NULL);
1339                if (retval < 0) {
1340                        ext4_warning(sb,
1341                             "error reading index page in directory #%lu",
1342                             dir->i_ino);
1343                        *err = retval;
1344                        goto errout;
1345                }
1346        } while (retval == 1);
1347
1348        *err = -ENOENT;
1349errout:
1350        dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1351        dx_release (frames);
1352        return NULL;
1353}
1354
1355static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1356{
1357        struct inode *inode;
1358        struct ext4_dir_entry_2 *de;
1359        struct buffer_head *bh;
1360
1361        if (dentry->d_name.len > EXT4_NAME_LEN)
1362                return ERR_PTR(-ENAMETOOLONG);
1363
1364        bh = ext4_find_entry(dir, &dentry->d_name, &de);
1365        inode = NULL;
1366        if (bh) {
1367                __u32 ino = le32_to_cpu(de->inode);
1368                brelse(bh);
1369                if (!ext4_valid_inum(dir->i_sb, ino)) {
1370                        EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1371                        return ERR_PTR(-EIO);
1372                }
1373                if (unlikely(ino == dir->i_ino)) {
1374                        EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
1375                                         dentry->d_name.len,
1376                                         dentry->d_name.name);
1377                        return ERR_PTR(-EIO);
1378                }
1379                inode = ext4_iget(dir->i_sb, ino);
1380                if (inode == ERR_PTR(-ESTALE)) {
1381                        EXT4_ERROR_INODE(dir,
1382                                         "deleted inode referenced: %u",
1383                                         ino);
1384                        return ERR_PTR(-EIO);
1385                }
1386        }
1387        return d_splice_alias(inode, dentry);
1388}
1389
1390
1391struct dentry *ext4_get_parent(struct dentry *child)
1392{
1393        __u32 ino;
1394        static const struct qstr dotdot = QSTR_INIT("..", 2);
1395        struct ext4_dir_entry_2 * de;
1396        struct buffer_head *bh;
1397
1398        bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1399        if (!bh)
1400                return ERR_PTR(-ENOENT);
1401        ino = le32_to_cpu(de->inode);
1402        brelse(bh);
1403
1404        if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1405                EXT4_ERROR_INODE(child->d_inode,
1406                                 "bad parent inode number: %u", ino);
1407                return ERR_PTR(-EIO);
1408        }
1409
1410        return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1411}
1412
1413#define S_SHIFT 12
1414static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1415        [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1416        [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1417        [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1418        [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1419        [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1420        [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1421        [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1422};
1423
1424static inline void ext4_set_de_type(struct super_block *sb,
1425                                struct ext4_dir_entry_2 *de,
1426                                umode_t mode) {
1427        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1428                de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1429}
1430
1431/*
1432 * Move count entries from end of map between two memory locations.
1433 * Returns pointer to last entry moved.
1434 */
1435static struct ext4_dir_entry_2 *
1436dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1437                unsigned blocksize)
1438{
1439        unsigned rec_len = 0;
1440
1441        while (count--) {
1442                struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1443                                                (from + (map->offs<<2));
1444                rec_len = EXT4_DIR_REC_LEN(de->name_len);
1445                memcpy (to, de, rec_len);
1446                ((struct ext4_dir_entry_2 *) to)->rec_len =
1447                                ext4_rec_len_to_disk(rec_len, blocksize);
1448                de->inode = 0;
1449                map++;
1450                to += rec_len;
1451        }
1452        return (struct ext4_dir_entry_2 *) (to - rec_len);
1453}
1454
1455/*
1456 * Compact each dir entry in the range to the minimal rec_len.
1457 * Returns pointer to last entry in range.
1458 */
1459static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1460{
1461        struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1462        unsigned rec_len = 0;
1463
1464        prev = to = de;
1465        while ((char*)de < base + blocksize) {
1466                next = ext4_next_entry(de, blocksize);
1467                if (de->inode && de->name_len) {
1468                        rec_len = EXT4_DIR_REC_LEN(de->name_len);
1469                        if (de > to)
1470                                memmove(to, de, rec_len);
1471                        to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1472                        prev = to;
1473                        to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1474                }
1475                de = next;
1476        }
1477        return prev;
1478}
1479
1480/*
1481 * Split a full leaf block to make room for a new dir entry.
1482 * Allocate a new block, and move entries so that they are approx. equally full.
1483 * Returns pointer to de in block into which the new entry will be inserted.
1484 */
1485static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1486                        struct buffer_head **bh,struct dx_frame *frame,
1487                        struct dx_hash_info *hinfo, int *error)
1488{
1489        unsigned blocksize = dir->i_sb->s_blocksize;
1490        unsigned count, continued;
1491        struct buffer_head *bh2;
1492        ext4_lblk_t newblock;
1493        u32 hash2;
1494        struct dx_map_entry *map;
1495        char *data1 = (*bh)->b_data, *data2;
1496        unsigned split, move, size;
1497        struct ext4_dir_entry_2 *de = NULL, *de2;
1498        struct ext4_dir_entry_tail *t;
1499        int     csum_size = 0;
1500        int     err = 0, i;
1501
1502        if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
1503                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1504                csum_size = sizeof(struct ext4_dir_entry_tail);
1505
1506        bh2 = ext4_append (handle, dir, &newblock, &err);
1507        if (!(bh2)) {
1508                brelse(*bh);
1509                *bh = NULL;
1510                goto errout;
1511        }
1512
1513        BUFFER_TRACE(*bh, "get_write_access");
1514        err = ext4_journal_get_write_access(handle, *bh);
1515        if (err)
1516                goto journal_error;
1517
1518        BUFFER_TRACE(frame->bh, "get_write_access");
1519        err = ext4_journal_get_write_access(handle, frame->bh);
1520        if (err)
1521                goto journal_error;
1522
1523        data2 = bh2->b_data;
1524
1525        /* create map in the end of data2 block */
1526        map = (struct dx_map_entry *) (data2 + blocksize);
1527        count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1528                             blocksize, hinfo, map);
1529        map -= count;
1530        dx_sort_map(map, count);
1531        /* Split the existing block in the middle, size-wise */
1532        size = 0;
1533        move = 0;
1534        for (i = count-1; i >= 0; i--) {
1535                /* is more than half of this entry in 2nd half of the block? */
1536                if (size + map[i].size/2 > blocksize/2)
1537                        break;
1538                size += map[i].size;
1539                move++;
1540        }
1541        /* map index at which we will split */
1542        split = count - move;
1543        hash2 = map[split].hash;
1544        continued = hash2 == map[split - 1].hash;
1545        dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1546                        (unsigned long)dx_get_block(frame->at),
1547                                        hash2, split, count-split));
1548
1549        /* Fancy dance to stay within two buffers */
1550        de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1551        de = dx_pack_dirents(data1, blocksize);
1552        de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1553                                           (char *) de,
1554                                           blocksize);
1555        de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1556                                            (char *) de2,
1557                                            blocksize);
1558        if (csum_size) {
1559                t = EXT4_DIRENT_TAIL(data2, blocksize);
1560                initialize_dirent_tail(t, blocksize);
1561
1562                t = EXT4_DIRENT_TAIL(data1, blocksize);
1563                initialize_dirent_tail(t, blocksize);
1564        }
1565
1566        dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1567        dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1568
1569        /* Which block gets the new entry? */
1570        if (hinfo->hash >= hash2)
1571        {
1572                swap(*bh, bh2);
1573                de = de2;
1574        }
1575        dx_insert_block(frame, hash2 + continued, newblock);
1576        err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1577        if (err)
1578                goto journal_error;
1579        err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1580        if (err)
1581                goto journal_error;
1582        brelse(bh2);
1583        dxtrace(dx_show_index("frame", frame->entries));
1584        return de;
1585
1586journal_error:
1587        brelse(*bh);
1588        brelse(bh2);
1589        *bh = NULL;
1590        ext4_std_error(dir->i_sb, err);
1591errout:
1592        *error = err;
1593        return NULL;
1594}
1595
1596/*
1597 * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1598 * it points to a directory entry which is guaranteed to be large
1599 * enough for new directory entry.  If de is NULL, then
1600 * add_dirent_to_buf will attempt search the directory block for
1601 * space.  It will return -ENOSPC if no space is available, and -EIO
1602 * and -EEXIST if directory entry already exists.
1603 */
1604static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1605                             struct inode *inode, struct ext4_dir_entry_2 *de,
1606                             struct buffer_head *bh)
1607{
1608        struct inode    *dir = dentry->d_parent->d_inode;
1609        const char      *name = dentry->d_name.name;
1610        int             namelen = dentry->d_name.len;
1611        unsigned int    offset = 0;
1612        unsigned int    blocksize = dir->i_sb->s_blocksize;
1613        unsigned short  reclen;
1614        int             nlen, rlen, err;
1615        char            *top;
1616        int             csum_size = 0;
1617
1618        if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1619                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1620                csum_size = sizeof(struct ext4_dir_entry_tail);
1621
1622        reclen = EXT4_DIR_REC_LEN(namelen);
1623        if (!de) {
1624                de = (struct ext4_dir_entry_2 *)bh->b_data;
1625                top = bh->b_data + (blocksize - csum_size) - reclen;
1626                while ((char *) de <= top) {
1627                        if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1628                                return -EIO;
1629                        if (ext4_match(namelen, name, de))
1630                                return -EEXIST;
1631                        nlen = EXT4_DIR_REC_LEN(de->name_len);
1632                        rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1633                        if ((de->inode? rlen - nlen: rlen) >= reclen)
1634                                break;
1635                        de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1636                        offset += rlen;
1637                }
1638                if ((char *) de > top)
1639                        return -ENOSPC;
1640        }
1641        BUFFER_TRACE(bh, "get_write_access");
1642        err = ext4_journal_get_write_access(handle, bh);
1643        if (err) {
1644                ext4_std_error(dir->i_sb, err);
1645                return err;
1646        }
1647
1648        /* By now the buffer is marked for journaling */
1649        nlen = EXT4_DIR_REC_LEN(de->name_len);
1650        rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1651        if (de->inode) {
1652                struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1653                de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1654                de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1655                de = de1;
1656        }
1657        de->file_type = EXT4_FT_UNKNOWN;
1658        de->inode = cpu_to_le32(inode->i_ino);
1659        ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1660        de->name_len = namelen;
1661        memcpy(de->name, name, namelen);
1662        /*
1663         * XXX shouldn't update any times until successful
1664         * completion of syscall, but too many callers depend
1665         * on this.
1666         *
1667         * XXX similarly, too many callers depend on
1668         * ext4_new_inode() setting the times, but error
1669         * recovery deletes the inode, so the worst that can
1670         * happen is that the times are slightly out of date
1671         * and/or different from the directory change time.
1672         */
1673        dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1674        ext4_update_dx_flag(dir);
1675        dir->i_version++;
1676        ext4_mark_inode_dirty(handle, dir);
1677        BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1678        err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1679        if (err)
1680                ext4_std_error(dir->i_sb, err);
1681        return 0;
1682}
1683
1684/*
1685 * This converts a one block unindexed directory to a 3 block indexed
1686 * directory, and adds the dentry to the indexed directory.
1687 */
1688static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1689                            struct inode *inode, struct buffer_head *bh)
1690{
1691        struct inode    *dir = dentry->d_parent->d_inode;
1692        const char      *name = dentry->d_name.name;
1693        int             namelen = dentry->d_name.len;
1694        struct buffer_head *bh2;
1695        struct dx_root  *root;
1696        struct dx_frame frames[2], *frame;
1697        struct dx_entry *entries;
1698        struct ext4_dir_entry_2 *de, *de2;
1699        struct ext4_dir_entry_tail *t;
1700        char            *data1, *top;
1701        unsigned        len;
1702        int             retval;
1703        unsigned        blocksize;
1704        struct dx_hash_info hinfo;
1705        ext4_lblk_t  block;
1706        struct fake_dirent *fde;
1707        int             csum_size = 0;
1708
1709        if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1710                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1711                csum_size = sizeof(struct ext4_dir_entry_tail);
1712
1713        blocksize =  dir->i_sb->s_blocksize;
1714        dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1715        retval = ext4_journal_get_write_access(handle, bh);
1716        if (retval) {
1717                ext4_std_error(dir->i_sb, retval);
1718                brelse(bh);
1719                return retval;
1720        }
1721        root = (struct dx_root *) bh->b_data;
1722
1723        /* The 0th block becomes the root, move the dirents out */
1724        fde = &root->dotdot;
1725        de = (struct ext4_dir_entry_2 *)((char *)fde +
1726                ext4_rec_len_from_disk(fde->rec_len, blocksize));
1727        if ((char *) de >= (((char *) root) + blocksize)) {
1728                EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1729                brelse(bh);
1730                return -EIO;
1731        }
1732        len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1733
1734        /* Allocate new block for the 0th block's dirents */
1735        bh2 = ext4_append(handle, dir, &block, &retval);
1736        if (!(bh2)) {
1737                brelse(bh);
1738                return retval;
1739        }
1740        ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1741        data1 = bh2->b_data;
1742
1743        memcpy (data1, de, len);
1744        de = (struct ext4_dir_entry_2 *) data1;
1745        top = data1 + len;
1746        while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1747                de = de2;
1748        de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1749                                           (char *) de,
1750                                           blocksize);
1751
1752        if (csum_size) {
1753                t = EXT4_DIRENT_TAIL(data1, blocksize);
1754                initialize_dirent_tail(t, blocksize);
1755        }
1756
1757        /* Initialize the root; the dot dirents already exist */
1758        de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1759        de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1760                                           blocksize);
1761        memset (&root->info, 0, sizeof(root->info));
1762        root->info.info_length = sizeof(root->info);
1763        root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1764        entries = root->entries;
1765        dx_set_block(entries, 1);
1766        dx_set_count(entries, 1);
1767        dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1768
1769        /* Initialize as for dx_probe */
1770        hinfo.hash_version = root->info.hash_version;
1771        if (hinfo.hash_version <= DX_HASH_TEA)
1772                hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1773        hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1774        ext4fs_dirhash(name, namelen, &hinfo);
1775        frame = frames;
1776        frame->entries = entries;
1777        frame->at = entries;
1778        frame->bh = bh;
1779        bh = bh2;
1780
1781        ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1782        ext4_handle_dirty_dirent_node(handle, dir, bh);
1783
1784        de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1785        if (!de) {
1786                /*
1787                 * Even if the block split failed, we have to properly write
1788                 * out all the changes we did so far. Otherwise we can end up
1789                 * with corrupted filesystem.
1790                 */
1791                ext4_mark_inode_dirty(handle, dir);
1792                dx_release(frames);
1793                return retval;
1794        }
1795        dx_release(frames);
1796
1797        retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1798        brelse(bh);
1799        return retval;
1800}
1801
1802/*
1803 *      ext4_add_entry()
1804 *
1805 * adds a file entry to the specified directory, using the same
1806 * semantics as ext4_find_entry(). It returns NULL if it failed.
1807 *
1808 * NOTE!! The inode part of 'de' is left at 0 - which means you
1809 * may not sleep between calling this and putting something into
1810 * the entry, as someone else might have used it while you slept.
1811 */
1812static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1813                          struct inode *inode)
1814{
1815        struct inode *dir = dentry->d_parent->d_inode;
1816        struct buffer_head *bh;
1817        struct ext4_dir_entry_2 *de;
1818        struct ext4_dir_entry_tail *t;
1819        struct super_block *sb;
1820        int     retval;
1821        int     dx_fallback=0;
1822        unsigned blocksize;
1823        ext4_lblk_t block, blocks;
1824        int     csum_size = 0;
1825
1826        if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1827                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1828                csum_size = sizeof(struct ext4_dir_entry_tail);
1829
1830        sb = dir->i_sb;
1831        blocksize = sb->s_blocksize;
1832        if (!dentry->d_name.len)
1833                return -EINVAL;
1834        if (is_dx(dir)) {
1835                retval = ext4_dx_add_entry(handle, dentry, inode);
1836                if (!retval || (retval != ERR_BAD_DX_DIR))
1837                        return retval;
1838                ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1839                dx_fallback++;
1840                ext4_mark_inode_dirty(handle, dir);
1841        }
1842        blocks = dir->i_size >> sb->s_blocksize_bits;
1843        for (block = 0; block < blocks; block++) {
1844                if (!(bh = ext4_bread(handle, dir, block, 0, &retval))) {
1845                        if (!retval) {
1846                                retval = -EIO;
1847                                ext4_error(inode->i_sb,
1848                                           "Directory hole detected on inode %lu\n",
1849                                           inode->i_ino);
1850                        }
1851                        return retval;
1852                }
1853                if (!buffer_verified(bh) &&
1854                    !ext4_dirent_csum_verify(dir,
1855                                (struct ext4_dir_entry *)bh->b_data))
1856                        return -EIO;
1857                set_buffer_verified(bh);
1858                retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1859                if (retval != -ENOSPC) {
1860                        brelse(bh);
1861                        return retval;
1862                }
1863
1864                if (blocks == 1 && !dx_fallback &&
1865                    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1866                        return make_indexed_dir(handle, dentry, inode, bh);
1867                brelse(bh);
1868        }
1869        bh = ext4_append(handle, dir, &block, &retval);
1870        if (!bh)
1871                return retval;
1872        de = (struct ext4_dir_entry_2 *) bh->b_data;
1873        de->inode = 0;
1874        de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
1875
1876        if (csum_size) {
1877                t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
1878                initialize_dirent_tail(t, blocksize);
1879        }
1880
1881        retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1882        brelse(bh);
1883        if (retval == 0)
1884                ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1885        return retval;
1886}
1887
1888/*
1889 * Returns 0 for success, or a negative error value
1890 */
1891static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1892                             struct inode *inode)
1893{
1894        struct dx_frame frames[2], *frame;
1895        struct dx_entry *entries, *at;
1896        struct dx_hash_info hinfo;
1897        struct buffer_head *bh;
1898        struct inode *dir = dentry->d_parent->d_inode;
1899        struct super_block *sb = dir->i_sb;
1900        struct ext4_dir_entry_2 *de;
1901        int err;
1902
1903        frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1904        if (!frame)
1905                return err;
1906        entries = frame->entries;
1907        at = frame->at;
1908
1909        if (!(bh = ext4_bread(handle, dir, dx_get_block(frame->at), 0, &err))) {
1910                if (!err) {
1911                        err = -EIO;
1912                        ext4_error(dir->i_sb,
1913                                   "Directory hole detected on inode %lu\n",
1914                                   dir->i_ino);
1915                }
1916                goto cleanup;
1917        }
1918
1919        if (!buffer_verified(bh) &&
1920            !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
1921                goto journal_error;
1922        set_buffer_verified(bh);
1923
1924        BUFFER_TRACE(bh, "get_write_access");
1925        err = ext4_journal_get_write_access(handle, bh);
1926        if (err)
1927                goto journal_error;
1928
1929        err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1930        if (err != -ENOSPC)
1931                goto cleanup;
1932
1933        /* Block full, should compress but for now just split */
1934        dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1935                       dx_get_count(entries), dx_get_limit(entries)));
1936        /* Need to split index? */
1937        if (dx_get_count(entries) == dx_get_limit(entries)) {
1938                ext4_lblk_t newblock;
1939                unsigned icount = dx_get_count(entries);
1940                int levels = frame - frames;
1941                struct dx_entry *entries2;
1942                struct dx_node *node2;
1943                struct buffer_head *bh2;
1944
1945                if (levels && (dx_get_count(frames->entries) ==
1946                               dx_get_limit(frames->entries))) {
1947                        ext4_warning(sb, "Directory index full!");
1948                        err = -ENOSPC;
1949                        goto cleanup;
1950                }
1951                bh2 = ext4_append (handle, dir, &newblock, &err);
1952                if (!(bh2))
1953                        goto cleanup;
1954                node2 = (struct dx_node *)(bh2->b_data);
1955                entries2 = node2->entries;
1956                memset(&node2->fake, 0, sizeof(struct fake_dirent));
1957                node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1958                                                           sb->s_blocksize);
1959                BUFFER_TRACE(frame->bh, "get_write_access");
1960                err = ext4_journal_get_write_access(handle, frame->bh);
1961                if (err)
1962                        goto journal_error;
1963                if (levels) {
1964                        unsigned icount1 = icount/2, icount2 = icount - icount1;
1965                        unsigned hash2 = dx_get_hash(entries + icount1);
1966                        dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1967                                       icount1, icount2));
1968
1969                        BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1970                        err = ext4_journal_get_write_access(handle,
1971                                                             frames[0].bh);
1972                        if (err)
1973                                goto journal_error;
1974
1975                        memcpy((char *) entries2, (char *) (entries + icount1),
1976                               icount2 * sizeof(struct dx_entry));
1977                        dx_set_count(entries, icount1);
1978                        dx_set_count(entries2, icount2);
1979                        dx_set_limit(entries2, dx_node_limit(dir));
1980
1981                        /* Which index block gets the new entry? */
1982                        if (at - entries >= icount1) {
1983                                frame->at = at = at - entries - icount1 + entries2;
1984                                frame->entries = entries = entries2;
1985                                swap(frame->bh, bh2);
1986                        }
1987                        dx_insert_block(frames + 0, hash2, newblock);
1988                        dxtrace(dx_show_index("node", frames[1].entries));
1989                        dxtrace(dx_show_index("node",
1990                               ((struct dx_node *) bh2->b_data)->entries));
1991                        err = ext4_handle_dirty_dx_node(handle, dir, bh2);
1992                        if (err)
1993                                goto journal_error;
1994                        brelse (bh2);
1995                } else {
1996                        dxtrace(printk(KERN_DEBUG
1997                                       "Creating second level index...\n"));
1998                        memcpy((char *) entries2, (char *) entries,
1999                               icount * sizeof(struct dx_entry));
2000                        dx_set_limit(entries2, dx_node_limit(dir));
2001
2002                        /* Set up root */
2003                        dx_set_count(entries, 1);
2004                        dx_set_block(entries + 0, newblock);
2005                        ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2006
2007                        /* Add new access path frame */
2008                        frame = frames + 1;
2009                        frame->at = at = at - entries + entries2;
2010                        frame->entries = entries = entries2;
2011                        frame->bh = bh2;
2012                        err = ext4_journal_get_write_access(handle,
2013                                                             frame->bh);
2014                        if (err)
2015                                goto journal_error;
2016                }
2017                err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2018                if (err) {
2019                        ext4_std_error(inode->i_sb, err);
2020                        goto cleanup;
2021                }
2022        }
2023        de = do_split(handle, dir, &bh, frame, &hinfo, &err);
2024        if (!de)
2025                goto cleanup;
2026        err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2027        goto cleanup;
2028
2029journal_error:
2030        ext4_std_error(dir->i_sb, err);
2031cleanup:
2032        if (bh)
2033                brelse(bh);
2034        dx_release(frames);
2035        return err;
2036}
2037
2038/*
2039 * ext4_delete_entry deletes a directory entry by merging it with the
2040 * previous entry
2041 */
2042static int ext4_delete_entry(handle_t *handle,
2043                             struct inode *dir,
2044                             struct ext4_dir_entry_2 *de_del,
2045                             struct buffer_head *bh)
2046{
2047        struct ext4_dir_entry_2 *de, *pde;
2048        unsigned int blocksize = dir->i_sb->s_blocksize;
2049        int csum_size = 0;
2050        int i, err;
2051
2052        if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2053                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2054                csum_size = sizeof(struct ext4_dir_entry_tail);
2055
2056        i = 0;
2057        pde = NULL;
2058        de = (struct ext4_dir_entry_2 *) bh->b_data;
2059        while (i < bh->b_size - csum_size) {
2060                if (ext4_check_dir_entry(dir, NULL, de, bh, i))
2061                        return -EIO;
2062                if (de == de_del)  {
2063                        BUFFER_TRACE(bh, "get_write_access");
2064                        err = ext4_journal_get_write_access(handle, bh);
2065                        if (unlikely(err)) {
2066                                ext4_std_error(dir->i_sb, err);
2067                                return err;
2068                        }
2069                        if (pde)
2070                                pde->rec_len = ext4_rec_len_to_disk(
2071                                        ext4_rec_len_from_disk(pde->rec_len,
2072                                                               blocksize) +
2073                                        ext4_rec_len_from_disk(de->rec_len,
2074                                                               blocksize),
2075                                        blocksize);
2076                        else
2077                                de->inode = 0;
2078                        dir->i_version++;
2079                        BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2080                        err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2081                        if (unlikely(err)) {
2082                                ext4_std_error(dir->i_sb, err);
2083                                return err;
2084                        }
2085                        return 0;
2086                }
2087                i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2088                pde = de;
2089                de = ext4_next_entry(de, blocksize);
2090        }
2091        return -ENOENT;
2092}
2093
2094/*
2095 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2096 * since this indicates that nlinks count was previously 1.
2097 */
2098static void ext4_inc_count(handle_t *handle, struct inode *inode)
2099{
2100        inc_nlink(inode);
2101        if (is_dx(inode) && inode->i_nlink > 1) {
2102                /* limit is 16-bit i_links_count */
2103                if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2104                        set_nlink(inode, 1);
2105                        EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2106                                              EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2107                }
2108        }
2109}
2110
2111/*
2112 * If a directory had nlink == 1, then we should let it be 1. This indicates
2113 * directory has >EXT4_LINK_MAX subdirs.
2114 */
2115static void ext4_dec_count(handle_t *handle, struct inode *inode)
2116{
2117        if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2118                drop_nlink(inode);
2119}
2120
2121
2122static int ext4_add_nondir(handle_t *handle,
2123                struct dentry *dentry, struct inode *inode)
2124{
2125        int err = ext4_add_entry(handle, dentry, inode);
2126        if (!err) {
2127                ext4_mark_inode_dirty(handle, inode);
2128                unlock_new_inode(inode);
2129                d_instantiate(dentry, inode);
2130                return 0;
2131        }
2132        drop_nlink(inode);
2133        unlock_new_inode(inode);
2134        iput(inode);
2135        return err;
2136}
2137
2138/*
2139 * By the time this is called, we already have created
2140 * the directory cache entry for the new file, but it
2141 * is so far negative - it has no inode.
2142 *
2143 * If the create succeeds, we fill in the inode information
2144 * with d_instantiate().
2145 */
2146static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2147                       bool excl)
2148{
2149        handle_t *handle;
2150        struct inode *inode;
2151        int err, retries = 0;
2152
2153        dquot_initialize(dir);
2154
2155retry:
2156        handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2157                                        EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2158                                        EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2159        if (IS_ERR(handle))
2160                return PTR_ERR(handle);
2161
2162        if (IS_DIRSYNC(dir))
2163                ext4_handle_sync(handle);
2164
2165        inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2166        err = PTR_ERR(inode);
2167        if (!IS_ERR(inode)) {
2168                inode->i_op = &ext4_file_inode_operations;
2169                inode->i_fop = &ext4_file_operations;
2170                ext4_set_aops(inode);
2171                err = ext4_add_nondir(handle, dentry, inode);
2172        }
2173        ext4_journal_stop(handle);
2174        if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2175                goto retry;
2176        return err;
2177}
2178
2179static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2180                      umode_t mode, dev_t rdev)
2181{
2182        handle_t *handle;
2183        struct inode *inode;
2184        int err, retries = 0;
2185
2186        if (!new_valid_dev(rdev))
2187                return -EINVAL;
2188
2189        dquot_initialize(dir);
2190
2191retry:
2192        handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2193                                        EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2194                                        EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2195        if (IS_ERR(handle))
2196                return PTR_ERR(handle);
2197
2198        if (IS_DIRSYNC(dir))
2199                ext4_handle_sync(handle);
2200
2201        inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2202        err = PTR_ERR(inode);
2203        if (!IS_ERR(inode)) {
2204                init_special_inode(inode, inode->i_mode, rdev);
2205                inode->i_op = &ext4_special_inode_operations;
2206                err = ext4_add_nondir(handle, dentry, inode);
2207        }
2208        ext4_journal_stop(handle);
2209        if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2210                goto retry;
2211        return err;
2212}
2213
2214static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2215{
2216        handle_t *handle;
2217        struct inode *inode;
2218        struct buffer_head *dir_block = NULL;
2219        struct ext4_dir_entry_2 *de;
2220        struct ext4_dir_entry_tail *t;
2221        unsigned int blocksize = dir->i_sb->s_blocksize;
2222        int csum_size = 0;
2223        int err, retries = 0;
2224
2225        if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2226                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2227                csum_size = sizeof(struct ext4_dir_entry_tail);
2228
2229        if (EXT4_DIR_LINK_MAX(dir))
2230                return -EMLINK;
2231
2232        dquot_initialize(dir);
2233
2234retry:
2235        handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2236                                        EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2237                                        EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2238        if (IS_ERR(handle))
2239                return PTR_ERR(handle);
2240
2241        if (IS_DIRSYNC(dir))
2242                ext4_handle_sync(handle);
2243
2244        inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
2245                               &dentry->d_name, 0, NULL);
2246        err = PTR_ERR(inode);
2247        if (IS_ERR(inode))
2248                goto out_stop;
2249
2250        inode->i_op = &ext4_dir_inode_operations;
2251        inode->i_fop = &ext4_dir_operations;
2252        inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
2253        if (!(dir_block = ext4_bread(handle, inode, 0, 1, &err))) {
2254                if (!err) {
2255                        err = -EIO;
2256                        ext4_error(inode->i_sb,
2257                                   "Directory hole detected on inode %lu\n",
2258                                   inode->i_ino);
2259                }
2260                goto out_clear_inode;
2261        }
2262        BUFFER_TRACE(dir_block, "get_write_access");
2263        err = ext4_journal_get_write_access(handle, dir_block);
2264        if (err)
2265                goto out_clear_inode;
2266        de = (struct ext4_dir_entry_2 *) dir_block->b_data;
2267        de->inode = cpu_to_le32(inode->i_ino);
2268        de->name_len = 1;
2269        de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2270                                           blocksize);
2271        strcpy(de->name, ".");
2272        ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2273        de = ext4_next_entry(de, blocksize);
2274        de->inode = cpu_to_le32(dir->i_ino);
2275        de->rec_len = ext4_rec_len_to_disk(blocksize -
2276                                           (csum_size + EXT4_DIR_REC_LEN(1)),
2277                                           blocksize);
2278        de->name_len = 2;
2279        strcpy(de->name, "..");
2280        ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2281        set_nlink(inode, 2);
2282
2283        if (csum_size) {
2284                t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2285                initialize_dirent_tail(t, blocksize);
2286        }
2287
2288        BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2289        err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2290        if (err)
2291                goto out_clear_inode;
2292        set_buffer_verified(dir_block);
2293        err = ext4_mark_inode_dirty(handle, inode);
2294        if (!err)
2295                err = ext4_add_entry(handle, dentry, inode);
2296        if (err) {
2297out_clear_inode:
2298                clear_nlink(inode);
2299                unlock_new_inode(inode);
2300                ext4_mark_inode_dirty(handle, inode);
2301                iput(inode);
2302                goto out_stop;
2303        }
2304        ext4_inc_count(handle, dir);
2305        ext4_update_dx_flag(dir);
2306        err = ext4_mark_inode_dirty(handle, dir);
2307        if (err)
2308                goto out_clear_inode;
2309        unlock_new_inode(inode);
2310        d_instantiate(dentry, inode);
2311out_stop:
2312        brelse(dir_block);
2313        ext4_journal_stop(handle);
2314        if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2315                goto retry;
2316        return err;
2317}
2318
2319/*
2320 * routine to check that the specified directory is empty (for rmdir)
2321 */
2322static int empty_dir(struct inode *inode)
2323{
2324        unsigned int offset;
2325        struct buffer_head *bh;
2326        struct ext4_dir_entry_2 *de, *de1;
2327        struct super_block *sb;
2328        int err = 0;
2329
2330        sb = inode->i_sb;
2331        if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
2332            !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
2333                if (err)
2334                        EXT4_ERROR_INODE(inode,
2335                                "error %d reading directory lblock 0", err);
2336                else
2337                        ext4_warning(inode->i_sb,
2338                                     "bad directory (dir #%lu) - no data block",
2339                                     inode->i_ino);
2340                return 1;
2341        }
2342        if (!buffer_verified(bh) &&
2343            !ext4_dirent_csum_verify(inode,
2344                        (struct ext4_dir_entry *)bh->b_data)) {
2345                EXT4_ERROR_INODE(inode, "checksum error reading directory "
2346                                 "lblock 0");
2347                return -EIO;
2348        }
2349        set_buffer_verified(bh);
2350        de = (struct ext4_dir_entry_2 *) bh->b_data;
2351        de1 = ext4_next_entry(de, sb->s_blocksize);
2352        if (le32_to_cpu(de->inode) != inode->i_ino ||
2353                        !le32_to_cpu(de1->inode) ||
2354                        strcmp(".", de->name) ||
2355                        strcmp("..", de1->name)) {
2356                ext4_warning(inode->i_sb,
2357                             "bad directory (dir #%lu) - no `.' or `..'",
2358                             inode->i_ino);
2359                brelse(bh);
2360                return 1;
2361        }
2362        offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2363                 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2364        de = ext4_next_entry(de1, sb->s_blocksize);
2365        while (offset < inode->i_size) {
2366                if (!bh ||
2367                    (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2368                        unsigned int lblock;
2369                        err = 0;
2370                        brelse(bh);
2371                        lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2372                        bh = ext4_bread(NULL, inode, lblock, 0, &err);
2373                        if (!bh) {
2374                                if (err)
2375                                        EXT4_ERROR_INODE(inode,
2376                                                "error %d reading directory "
2377                                                "lblock %u", err, lblock);
2378                                else
2379                                        ext4_warning(inode->i_sb,
2380                                                "bad directory (dir #%lu) - no data block",
2381                                                inode->i_ino);
2382
2383                                offset += sb->s_blocksize;
2384                                continue;
2385                        }
2386                        if (!buffer_verified(bh) &&
2387                            !ext4_dirent_csum_verify(inode,
2388                                        (struct ext4_dir_entry *)bh->b_data)) {
2389                                EXT4_ERROR_INODE(inode, "checksum error "
2390                                                 "reading directory lblock 0");
2391                                return -EIO;
2392                        }
2393                        set_buffer_verified(bh);
2394                        de = (struct ext4_dir_entry_2 *) bh->b_data;
2395                }
2396                if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
2397                        de = (struct ext4_dir_entry_2 *)(bh->b_data +
2398                                                         sb->s_blocksize);
2399                        offset = (offset | (sb->s_blocksize - 1)) + 1;
2400                        continue;
2401                }
2402                if (le32_to_cpu(de->inode)) {
2403                        brelse(bh);
2404                        return 0;
2405                }
2406                offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2407                de = ext4_next_entry(de, sb->s_blocksize);
2408        }
2409        brelse(bh);
2410        return 1;
2411}
2412
2413/* ext4_orphan_add() links an unlinked or truncated inode into a list of
2414 * such inodes, starting at the superblock, in case we crash before the
2415 * file is closed/deleted, or in case the inode truncate spans multiple
2416 * transactions and the last transaction is not recovered after a crash.
2417 *
2418 * At filesystem recovery time, we walk this list deleting unlinked
2419 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2420 */
2421int ext4_orphan_add(handle_t *handle, struct inode *inode)
2422{
2423        struct super_block *sb = inode->i_sb;
2424        struct ext4_iloc iloc;
2425        int err = 0, rc;
2426
2427        if (!EXT4_SB(sb)->s_journal)
2428                return 0;
2429
2430        mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2431        if (!list_empty(&EXT4_I(inode)->i_orphan))
2432                goto out_unlock;
2433
2434        /*
2435         * Orphan handling is only valid for files with data blocks
2436         * being truncated, or files being unlinked. Note that we either
2437         * hold i_mutex, or the inode can not be referenced from outside,
2438         * so i_nlink should not be bumped due to race
2439         */
2440        J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2441                  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2442
2443        BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2444        err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2445        if (err)
2446                goto out_unlock;
2447
2448        err = ext4_reserve_inode_write(handle, inode, &iloc);
2449        if (err)
2450                goto out_unlock;
2451        /*
2452         * Due to previous errors inode may be already a part of on-disk
2453         * orphan list. If so skip on-disk list modification.
2454         */
2455        if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2456                (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2457                        goto mem_insert;
2458
2459        /* Insert this inode at the head of the on-disk orphan list... */
2460        NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2461        EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2462        err = ext4_handle_dirty_super(handle, sb);
2463        rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2464        if (!err)
2465                err = rc;
2466
2467        /* Only add to the head of the in-memory list if all the
2468         * previous operations succeeded.  If the orphan_add is going to
2469         * fail (possibly taking the journal offline), we can't risk
2470         * leaving the inode on the orphan list: stray orphan-list
2471         * entries can cause panics at unmount time.
2472         *
2473         * This is safe: on error we're going to ignore the orphan list
2474         * anyway on the next recovery. */
2475mem_insert:
2476        if (!err)
2477                list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2478
2479        jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2480        jbd_debug(4, "orphan inode %lu will point to %d\n",
2481                        inode->i_ino, NEXT_ORPHAN(inode));
2482out_unlock:
2483        mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2484        ext4_std_error(inode->i_sb, err);
2485        return err;
2486}
2487
2488/*
2489 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2490 * of such inodes stored on disk, because it is finally being cleaned up.
2491 */
2492int ext4_orphan_del(handle_t *handle, struct inode *inode)
2493{
2494        struct list_head *prev;
2495        struct ext4_inode_info *ei = EXT4_I(inode);
2496        struct ext4_sb_info *sbi;
2497        __u32 ino_next;
2498        struct ext4_iloc iloc;
2499        int err = 0;
2500
2501        if (!EXT4_SB(inode->i_sb)->s_journal)
2502                return 0;
2503
2504        mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2505        if (list_empty(&ei->i_orphan))
2506                goto out;
2507
2508        ino_next = NEXT_ORPHAN(inode);
2509        prev = ei->i_orphan.prev;
2510        sbi = EXT4_SB(inode->i_sb);
2511
2512        jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2513
2514        list_del_init(&ei->i_orphan);
2515
2516        /* If we're on an error path, we may not have a valid
2517         * transaction handle with which to update the orphan list on
2518         * disk, but we still need to remove the inode from the linked
2519         * list in memory. */
2520        if (!handle)
2521                goto out;
2522
2523        err = ext4_reserve_inode_write(handle, inode, &iloc);
2524        if (err)
2525                goto out_err;
2526
2527        if (prev == &sbi->s_orphan) {
2528                jbd_debug(4, "superblock will point to %u\n", ino_next);
2529                BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2530                err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2531                if (err)
2532                        goto out_brelse;
2533                sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2534                err = ext4_handle_dirty_super(handle, inode->i_sb);
2535        } else {
2536                struct ext4_iloc iloc2;
2537                struct inode *i_prev =
2538                        &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2539
2540                jbd_debug(4, "orphan inode %lu will point to %u\n",
2541                          i_prev->i_ino, ino_next);
2542                err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2543                if (err)
2544                        goto out_brelse;
2545                NEXT_ORPHAN(i_prev) = ino_next;
2546                err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2547        }
2548        if (err)
2549                goto out_brelse;
2550        NEXT_ORPHAN(inode) = 0;
2551        err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2552
2553out_err:
2554        ext4_std_error(inode->i_sb, err);
2555out:
2556        mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2557        return err;
2558
2559out_brelse:
2560        brelse(iloc.bh);
2561        goto out_err;
2562}
2563
2564static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2565{
2566        int retval;
2567        struct inode *inode;
2568        struct buffer_head *bh;
2569        struct ext4_dir_entry_2 *de;
2570        handle_t *handle;
2571
2572        /* Initialize quotas before so that eventual writes go in
2573         * separate transaction */
2574        dquot_initialize(dir);
2575        dquot_initialize(dentry->d_inode);
2576
2577        handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2578        if (IS_ERR(handle))
2579                return PTR_ERR(handle);
2580
2581        retval = -ENOENT;
2582        bh = ext4_find_entry(dir, &dentry->d_name, &de);
2583        if (!bh)
2584                goto end_rmdir;
2585
2586        if (IS_DIRSYNC(dir))
2587                ext4_handle_sync(handle);
2588
2589        inode = dentry->d_inode;
2590
2591        retval = -EIO;
2592        if (le32_to_cpu(de->inode) != inode->i_ino)
2593                goto end_rmdir;
2594
2595        retval = -ENOTEMPTY;
2596        if (!empty_dir(inode))
2597                goto end_rmdir;
2598
2599        retval = ext4_delete_entry(handle, dir, de, bh);
2600        if (retval)
2601                goto end_rmdir;
2602        if (!EXT4_DIR_LINK_EMPTY(inode))
2603                ext4_warning(inode->i_sb,
2604                             "empty directory has too many links (%d)",
2605                             inode->i_nlink);
2606        inode->i_version++;
2607        clear_nlink(inode);
2608        /* There's no need to set i_disksize: the fact that i_nlink is
2609         * zero will ensure that the right thing happens during any
2610         * recovery. */
2611        inode->i_size = 0;
2612        ext4_orphan_add(handle, inode);
2613        inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2614        ext4_mark_inode_dirty(handle, inode);
2615        ext4_dec_count(handle, dir);
2616        ext4_update_dx_flag(dir);
2617        ext4_mark_inode_dirty(handle, dir);
2618
2619end_rmdir:
2620        ext4_journal_stop(handle);
2621        brelse(bh);
2622        return retval;
2623}
2624
2625static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2626{
2627        int retval;
2628        struct inode *inode;
2629        struct buffer_head *bh;
2630        struct ext4_dir_entry_2 *de;
2631        handle_t *handle;
2632
2633        trace_ext4_unlink_enter(dir, dentry);
2634        /* Initialize quotas before so that eventual writes go
2635         * in separate transaction */
2636        dquot_initialize(dir);
2637        dquot_initialize(dentry->d_inode);
2638
2639        handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2640        if (IS_ERR(handle))
2641                return PTR_ERR(handle);
2642
2643        if (IS_DIRSYNC(dir))
2644                ext4_handle_sync(handle);
2645
2646        retval = -ENOENT;
2647        bh = ext4_find_entry(dir, &dentry->d_name, &de);
2648        if (!bh)
2649                goto end_unlink;
2650
2651        inode = dentry->d_inode;
2652
2653        retval = -EIO;
2654        if (le32_to_cpu(de->inode) != inode->i_ino)
2655                goto end_unlink;
2656
2657        if (!inode->i_nlink) {
2658                ext4_warning(inode->i_sb,
2659                             "Deleting nonexistent file (%lu), %d",
2660                             inode->i_ino, inode->i_nlink);
2661                set_nlink(inode, 1);
2662        }
2663        retval = ext4_delete_entry(handle, dir, de, bh);
2664        if (retval)
2665                goto end_unlink;
2666        dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2667        ext4_update_dx_flag(dir);
2668        ext4_mark_inode_dirty(handle, dir);
2669        drop_nlink(inode);
2670        if (!inode->i_nlink)
2671                ext4_orphan_add(handle, inode);
2672        inode->i_ctime = ext4_current_time(inode);
2673        ext4_mark_inode_dirty(handle, inode);
2674        retval = 0;
2675
2676end_unlink:
2677        ext4_journal_stop(handle);
2678        brelse(bh);
2679        trace_ext4_unlink_exit(dentry, retval);
2680        return retval;
2681}
2682
2683static int ext4_symlink(struct inode *dir,
2684                        struct dentry *dentry, const char *symname)
2685{
2686        handle_t *handle;
2687        struct inode *inode;
2688        int l, err, retries = 0;
2689        int credits;
2690
2691        l = strlen(symname)+1;
2692        if (l > dir->i_sb->s_blocksize)
2693                return -ENAMETOOLONG;
2694
2695        dquot_initialize(dir);
2696
2697        if (l > EXT4_N_BLOCKS * 4) {
2698                /*
2699                 * For non-fast symlinks, we just allocate inode and put it on
2700                 * orphan list in the first transaction => we need bitmap,
2701                 * group descriptor, sb, inode block, quota blocks, and
2702                 * possibly selinux xattr blocks.
2703                 */
2704                credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2705                          EXT4_XATTR_TRANS_BLOCKS;
2706        } else {
2707                /*
2708                 * Fast symlink. We have to add entry to directory
2709                 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2710                 * allocate new inode (bitmap, group descriptor, inode block,
2711                 * quota blocks, sb is already counted in previous macros).
2712                 */
2713                credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2714                          EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2715                          EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2716        }
2717retry:
2718        handle = ext4_journal_start(dir, credits);
2719        if (IS_ERR(handle))
2720                return PTR_ERR(handle);
2721
2722        if (IS_DIRSYNC(dir))
2723                ext4_handle_sync(handle);
2724
2725        inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2726                               &dentry->d_name, 0, NULL);
2727        err = PTR_ERR(inode);
2728        if (IS_ERR(inode))
2729                goto out_stop;
2730
2731        if (l > EXT4_N_BLOCKS * 4) {
2732                inode->i_op = &ext4_symlink_inode_operations;
2733                ext4_set_aops(inode);
2734                /*
2735                 * We cannot call page_symlink() with transaction started
2736                 * because it calls into ext4_write_begin() which can wait
2737                 * for transaction commit if we are running out of space
2738                 * and thus we deadlock. So we have to stop transaction now
2739                 * and restart it when symlink contents is written.
2740                 * 
2741                 * To keep fs consistent in case of crash, we have to put inode
2742                 * to orphan list in the mean time.
2743                 */
2744                drop_nlink(inode);
2745                err = ext4_orphan_add(handle, inode);
2746                ext4_journal_stop(handle);
2747                if (err)
2748                        goto err_drop_inode;
2749                err = __page_symlink(inode, symname, l, 1);
2750                if (err)
2751                        goto err_drop_inode;
2752                /*
2753                 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2754                 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2755                 */
2756                handle = ext4_journal_start(dir,
2757                                EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2758                                EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2759                if (IS_ERR(handle)) {
2760                        err = PTR_ERR(handle);
2761                        goto err_drop_inode;
2762                }
2763                set_nlink(inode, 1);
2764                err = ext4_orphan_del(handle, inode);
2765                if (err) {
2766                        ext4_journal_stop(handle);
2767                        clear_nlink(inode);
2768                        goto err_drop_inode;
2769                }
2770        } else {
2771                /* clear the extent format for fast symlink */
2772                ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2773                inode->i_op = &ext4_fast_symlink_inode_operations;
2774                memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2775                inode->i_size = l-1;
2776        }
2777        EXT4_I(inode)->i_disksize = inode->i_size;
2778        err = ext4_add_nondir(handle, dentry, inode);
2779out_stop:
2780        ext4_journal_stop(handle);
2781        if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2782                goto retry;
2783        return err;
2784err_drop_inode:
2785        unlock_new_inode(inode);
2786        iput(inode);
2787        return err;
2788}
2789
2790static int ext4_link(struct dentry *old_dentry,
2791                     struct inode *dir, struct dentry *dentry)
2792{
2793        handle_t *handle;
2794        struct inode *inode = old_dentry->d_inode;
2795        int err, retries = 0;
2796
2797        if (inode->i_nlink >= EXT4_LINK_MAX)
2798                return -EMLINK;
2799
2800        dquot_initialize(dir);
2801
2802retry:
2803        handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2804                                        EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2805        if (IS_ERR(handle))
2806                return PTR_ERR(handle);
2807
2808        if (IS_DIRSYNC(dir))
2809                ext4_handle_sync(handle);
2810
2811        inode->i_ctime = ext4_current_time(inode);
2812        ext4_inc_count(handle, inode);
2813        ihold(inode);
2814
2815        err = ext4_add_entry(handle, dentry, inode);
2816        if (!err) {
2817                ext4_mark_inode_dirty(handle, inode);
2818                d_instantiate(dentry, inode);
2819        } else {
2820                drop_nlink(inode);
2821                iput(inode);
2822        }
2823        ext4_journal_stop(handle);
2824        if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2825                goto retry;
2826        return err;
2827}
2828
2829#define PARENT_INO(buffer, size) \
2830        (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2831
2832/*
2833 * Anybody can rename anything with this: the permission checks are left to the
2834 * higher-level routines.
2835 */
2836static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2837                       struct inode *new_dir, struct dentry *new_dentry)
2838{
2839        handle_t *handle;
2840        struct inode *old_inode, *new_inode;
2841        struct buffer_head *old_bh, *new_bh, *dir_bh;
2842        struct ext4_dir_entry_2 *old_de, *new_de;
2843        int retval, force_da_alloc = 0;
2844
2845        dquot_initialize(old_dir);
2846        dquot_initialize(new_dir);
2847
2848        old_bh = new_bh = dir_bh = NULL;
2849
2850        /* Initialize quotas before so that eventual writes go
2851         * in separate transaction */
2852        if (new_dentry->d_inode)
2853                dquot_initialize(new_dentry->d_inode);
2854        handle = ext4_journal_start(old_dir, 2 *
2855                                        EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2856                                        EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2857        if (IS_ERR(handle))
2858                return PTR_ERR(handle);
2859
2860        if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2861                ext4_handle_sync(handle);
2862
2863        old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2864        /*
2865         *  Check for inode number is _not_ due to possible IO errors.
2866         *  We might rmdir the source, keep it as pwd of some process
2867         *  and merrily kill the link to whatever was created under the
2868         *  same name. Goodbye sticky bit ;-<
2869         */
2870        old_inode = old_dentry->d_inode;
2871        retval = -ENOENT;
2872        if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2873                goto end_rename;
2874
2875        new_inode = new_dentry->d_inode;
2876        new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2877        if (new_bh) {
2878                if (!new_inode) {
2879                        brelse(new_bh);
2880                        new_bh = NULL;
2881                }
2882        }
2883        if (S_ISDIR(old_inode->i_mode)) {
2884                if (new_inode) {
2885                        retval = -ENOTEMPTY;
2886                        if (!empty_dir(new_inode))
2887                                goto end_rename;
2888                }
2889                retval = -EIO;
2890                if (!(dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval))) {
2891                        if (!retval) {
2892                                retval = -EIO;
2893                                ext4_error(old_inode->i_sb,
2894                                           "Directory hole detected on inode %lu\n",
2895                                           old_inode->i_ino);
2896                        }
2897                        goto end_rename;
2898                }
2899                if (!buffer_verified(dir_bh) &&
2900                    !ext4_dirent_csum_verify(old_inode,
2901                                (struct ext4_dir_entry *)dir_bh->b_data))
2902                        goto end_rename;
2903                set_buffer_verified(dir_bh);
2904                if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2905                                old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2906                        goto end_rename;
2907                retval = -EMLINK;
2908                if (!new_inode && new_dir != old_dir &&
2909                    EXT4_DIR_LINK_MAX(new_dir))
2910                        goto end_rename;
2911                BUFFER_TRACE(dir_bh, "get_write_access");
2912                retval = ext4_journal_get_write_access(handle, dir_bh);
2913                if (retval)
2914                        goto end_rename;
2915        }
2916        if (!new_bh) {
2917                retval = ext4_add_entry(handle, new_dentry, old_inode);
2918                if (retval)
2919                        goto end_rename;
2920        } else {
2921                BUFFER_TRACE(new_bh, "get write access");
2922                retval = ext4_journal_get_write_access(handle, new_bh);
2923                if (retval)
2924                        goto end_rename;
2925                new_de->inode = cpu_to_le32(old_inode->i_ino);
2926                if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2927                                              EXT4_FEATURE_INCOMPAT_FILETYPE))
2928                        new_de->file_type = old_de->file_type;
2929                new_dir->i_version++;
2930                new_dir->i_ctime = new_dir->i_mtime =
2931                                        ext4_current_time(new_dir);
2932                ext4_mark_inode_dirty(handle, new_dir);
2933                BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2934                retval = ext4_handle_dirty_dirent_node(handle, new_dir, new_bh);
2935                if (unlikely(retval)) {
2936                        ext4_std_error(new_dir->i_sb, retval);
2937                        goto end_rename;
2938                }
2939                brelse(new_bh);
2940                new_bh = NULL;
2941        }
2942
2943        /*
2944         * Like most other Unix systems, set the ctime for inodes on a
2945         * rename.
2946         */
2947        old_inode->i_ctime = ext4_current_time(old_inode);
2948        ext4_mark_inode_dirty(handle, old_inode);
2949
2950        /*
2951         * ok, that's it
2952         */
2953        if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2954            old_de->name_len != old_dentry->d_name.len ||
2955            strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2956            (retval = ext4_delete_entry(handle, old_dir,
2957                                        old_de, old_bh)) == -ENOENT) {
2958                /* old_de could have moved from under us during htree split, so
2959                 * make sure that we are deleting the right entry.  We might
2960                 * also be pointing to a stale entry in the unused part of
2961                 * old_bh so just checking inum and the name isn't enough. */
2962                struct buffer_head *old_bh2;
2963                struct ext4_dir_entry_2 *old_de2;
2964
2965                old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2966                if (old_bh2) {
2967                        retval = ext4_delete_entry(handle, old_dir,
2968                                                   old_de2, old_bh2);
2969                        brelse(old_bh2);
2970                }
2971        }
2972        if (retval) {
2973                ext4_warning(old_dir->i_sb,
2974                                "Deleting old file (%lu), %d, error=%d",
2975                                old_dir->i_ino, old_dir->i_nlink, retval);
2976        }
2977
2978        if (new_inode) {
2979                ext4_dec_count(handle, new_inode);
2980                new_inode->i_ctime = ext4_current_time(new_inode);
2981        }
2982        old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2983        ext4_update_dx_flag(old_dir);
2984        if (dir_bh) {
2985                PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2986                                                cpu_to_le32(new_dir->i_ino);
2987                BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2988                if (is_dx(old_inode)) {
2989                        retval = ext4_handle_dirty_dx_node(handle,
2990                                                           old_inode,
2991                                                           dir_bh);
2992                } else {
2993                        retval = ext4_handle_dirty_dirent_node(handle,
2994                                                               old_inode,
2995                                                               dir_bh);
2996                }
2997                if (retval) {
2998                        ext4_std_error(old_dir->i_sb, retval);
2999                        goto end_rename;
3000                }
3001                ext4_dec_count(handle, old_dir);
3002                if (new_inode) {
3003                        /* checked empty_dir above, can't have another parent,
3004                         * ext4_dec_count() won't work for many-linked dirs */
3005                        clear_nlink(new_inode);
3006                } else {
3007                        ext4_inc_count(handle, new_dir);
3008                        ext4_update_dx_flag(new_dir);
3009                        ext4_mark_inode_dirty(handle, new_dir);
3010                }
3011        }
3012        ext4_mark_inode_dirty(handle, old_dir);
3013        if (new_inode) {
3014                ext4_mark_inode_dirty(handle, new_inode);
3015                if (!new_inode->i_nlink)
3016                        ext4_orphan_add(handle, new_inode);
3017                if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
3018                        force_da_alloc = 1;
3019        }
3020        retval = 0;
3021
3022end_rename:
3023        brelse(dir_bh);
3024        brelse(old_bh);
3025        brelse(new_bh);
3026        ext4_journal_stop(handle);
3027        if (retval == 0 && force_da_alloc)
3028                ext4_alloc_da_blocks(old_inode);
3029        return retval;
3030}
3031
3032/*
3033 * directories can handle most operations...
3034 */
3035const struct inode_operations ext4_dir_inode_operations = {
3036        .create         = ext4_create,
3037        .lookup         = ext4_lookup,
3038        .link           = ext4_link,
3039        .unlink         = ext4_unlink,
3040        .symlink        = ext4_symlink,
3041        .mkdir          = ext4_mkdir,
3042        .rmdir          = ext4_rmdir,
3043        .mknod          = ext4_mknod,
3044        .rename         = ext4_rename,
3045        .setattr        = ext4_setattr,
3046#ifdef CONFIG_EXT4_FS_XATTR
3047        .setxattr       = generic_setxattr,
3048        .getxattr       = generic_getxattr,
3049        .listxattr      = ext4_listxattr,
3050        .removexattr    = generic_removexattr,
3051#endif
3052        .get_acl        = ext4_get_acl,
3053        .fiemap         = ext4_fiemap,
3054};
3055
3056const struct inode_operations ext4_special_inode_operations = {
3057        .setattr        = ext4_setattr,
3058#ifdef CONFIG_EXT4_FS_XATTR
3059        .setxattr       = generic_setxattr,
3060        .getxattr       = generic_getxattr,
3061        .listxattr      = ext4_listxattr,
3062        .removexattr    = generic_removexattr,
3063#endif
3064        .get_acl        = ext4_get_acl,
3065};
3066
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