fs/gfs2/dir.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 /*
  11  * Implements Extendible Hashing as described in:
  12  *   "Extendible Hashing" by Fagin, et al in
  13  *     __ACM Trans. on Database Systems__, Sept 1979.
  14  *
  15  *
  16  * Here's the layout of dirents which is essentially the same as that of ext2
  17  * within a single block. The field de_name_len is the number of bytes
  18  * actually required for the name (no null terminator). The field de_rec_len
  19  * is the number of bytes allocated to the dirent. The offset of the next
  20  * dirent in the block is (dirent + dirent->de_rec_len). When a dirent is
  21  * deleted, the preceding dirent inherits its allocated space, ie
  22  * prev->de_rec_len += deleted->de_rec_len. Since the next dirent is obtained
  23  * by adding de_rec_len to the current dirent, this essentially causes the
  24  * deleted dirent to get jumped over when iterating through all the dirents.
  25  *
  26  * When deleting the first dirent in a block, there is no previous dirent so
  27  * the field de_ino is set to zero to designate it as deleted. When allocating
  28  * a dirent, gfs2_dirent_alloc iterates through the dirents in a block. If the
  29  * first dirent has (de_ino == 0) and de_rec_len is large enough, this first
  30  * dirent is allocated. Otherwise it must go through all the 'used' dirents
  31  * searching for one in which the amount of total space minus the amount of
  32  * used space will provide enough space for the new dirent.
  33  *
  34  * There are two types of blocks in which dirents reside. In a stuffed dinode,
  35  * the dirents begin at offset sizeof(struct gfs2_dinode) from the beginning of
  36  * the block.  In leaves, they begin at offset sizeof(struct gfs2_leaf) from the
  37  * beginning of the leaf block. The dirents reside in leaves when
  38  *
  39  * dip->i_diskflags & GFS2_DIF_EXHASH is true
  40  *
  41  * Otherwise, the dirents are "linear", within a single stuffed dinode block.
  42  *
  43  * When the dirents are in leaves, the actual contents of the directory file are
  44  * used as an array of 64-bit block pointers pointing to the leaf blocks. The
  45  * dirents are NOT in the directory file itself. There can be more than one
  46  * block pointer in the array that points to the same leaf. In fact, when a
  47  * directory is first converted from linear to exhash, all of the pointers
  48  * point to the same leaf.
  49  *
  50  * When a leaf is completely full, the size of the hash table can be
  51  * doubled unless it is already at the maximum size which is hard coded into
  52  * GFS2_DIR_MAX_DEPTH. After that, leaves are chained together in a linked list,
  53  * but never before the maximum hash table size has been reached.
  54  */
  55
  56 #include <linux/slab.h>
  57 #include <linux/spinlock.h>
  58 #include <linux/buffer_head.h>
  59 #include <linux/sort.h>
  60 #include <linux/gfs2_ondisk.h>
  61 #include <linux/crc32.h>
  62 #include <linux/vmalloc.h>
  63
  64 #include "gfs2.h"
  65 #include "incore.h"
  66 #include "dir.h"
  67 #include "glock.h"
  68 #include "inode.h"
  69 #include "meta_io.h"
  70 #include "quota.h"
  71 #include "rgrp.h"
  72 #include "trans.h"
  73 #include "bmap.h"
  74 #include "util.h"
  75
  76 #define IS_LEAF     1 /* Hashed (leaf) directory */
  77 #define IS_DINODE   2 /* Linear (stuffed dinode block) directory */
  78
  79 #define gfs2_disk_hash2offset(h) (((u64)(h)) >> 1)
  80 #define gfs2_dir_offset2hash(p) ((u32)(((u64)(p)) << 1))
  81
  82 typedef int (*leaf_call_t) (struct gfs2_inode *dip, u32 index, u32 len,
  83                             u64 leaf_no, void *data);
  84 typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent,
  85                             const struct qstr *name, void *opaque);
  86
  87
  88 int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
  89                             struct buffer_head **bhp)
  90 {
  91         struct buffer_head *bh;
  92
  93         bh = gfs2_meta_new(ip->i_gl, block);
  94         gfs2_trans_add_bh(ip->i_gl, bh, 1);
  95         gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
  96         gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
  97         *bhp = bh;
  98         return 0;
  99 }
 100
 101 static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, u64 block,
 102                                         struct buffer_head **bhp)
 103 {
 104         struct buffer_head *bh;
 105         int error;
 106
 107         error = gfs2_meta_read(ip->i_gl, block, DIO_WAIT, &bh);
 108         if (error)
 109                 return error;
 110         if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_JD)) {
 111                 brelse(bh);
 112                 return -EIO;
 113         }
 114         *bhp = bh;
 115         return 0;
 116 }
 117
 118 static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
 119                                   unsigned int offset, unsigned int size)
 120 {
 121         struct buffer_head *dibh;
 122         int error;
 123
 124         error = gfs2_meta_inode_buffer(ip, &dibh);
 125         if (error)
 126                 return error;
 127
 128         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 129         memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
 130         if (ip->i_disksize < offset + size)
 131                 ip->i_disksize = offset + size;
 132         ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 133         gfs2_dinode_out(ip, dibh->b_data);
 134
 135         brelse(dibh);
 136
 137         return size;
 138 }
 139
 140
 141
 142 /**
 143  * gfs2_dir_write_data - Write directory information to the inode
 144  * @ip: The GFS2 inode
 145  * @buf: The buffer containing information to be written
 146  * @offset: The file offset to start writing at
 147  * @size: The amount of data to write
 148  *
 149  * Returns: The number of bytes correctly written or error code
 150  */
 151 static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
 152                                u64 offset, unsigned int size)
 153 {
 154         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 155         struct buffer_head *dibh;
 156         u64 lblock, dblock;
 157         u32 extlen = 0;
 158         unsigned int o;
 159         int copied = 0;
 160         int error = 0;
 161         int new = 0;
 162
 163         if (!size)
 164                 return 0;
 165
 166         if (gfs2_is_stuffed(ip) &&
 167             offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
 168                 return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
 169                                               size);
 170
 171         if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
 172                 return -EINVAL;
 173
 174         if (gfs2_is_stuffed(ip)) {
 175                 error = gfs2_unstuff_dinode(ip, NULL);
 176                 if (error)
 177                         return error;
 178         }
 179
 180         lblock = offset;
 181         o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
 182
 183         while (copied < size) {
 184                 unsigned int amount;
 185                 struct buffer_head *bh;
 186
 187                 amount = size - copied;
 188                 if (amount > sdp->sd_sb.sb_bsize - o)
 189                         amount = sdp->sd_sb.sb_bsize - o;
 190
 191                 if (!extlen) {
 192                         new = 1;
 193                         error = gfs2_extent_map(&ip->i_inode, lblock, &new,
 194                                                 &dblock, &extlen);
 195                         if (error)
 196                                 goto fail;
 197                         error = -EIO;
 198                         if (gfs2_assert_withdraw(sdp, dblock))
 199                                 goto fail;
 200                 }
 201
 202                 if (amount == sdp->sd_jbsize || new)
 203                         error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
 204                 else
 205                         error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
 206
 207                 if (error)
 208                         goto fail;
 209
 210                 gfs2_trans_add_bh(ip->i_gl, bh, 1);
 211                 memcpy(bh->b_data + o, buf, amount);
 212                 brelse(bh);
 213
 214                 buf += amount;
 215                 copied += amount;
 216                 lblock++;
 217                 dblock++;
 218                 extlen--;
 219
 220                 o = sizeof(struct gfs2_meta_header);
 221         }
 222
 223 out:
 224         error = gfs2_meta_inode_buffer(ip, &dibh);
 225         if (error)
 226                 return error;
 227
 228         if (ip->i_disksize < offset + copied)
 229                 ip->i_disksize = offset + copied;
 230         ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 231
 232         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 233         gfs2_dinode_out(ip, dibh->b_data);
 234         brelse(dibh);
 235
 236         return copied;
 237 fail:
 238         if (copied)
 239                 goto out;
 240         return error;
 241 }
 242
 243 static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, char *buf,
 244                                  u64 offset, unsigned int size)
 245 {
 246         struct buffer_head *dibh;
 247         int error;
 248
 249         error = gfs2_meta_inode_buffer(ip, &dibh);
 250         if (!error) {
 251                 offset += sizeof(struct gfs2_dinode);
 252                 memcpy(buf, dibh->b_data + offset, size);
 253                 brelse(dibh);
 254         }
 255
 256         return (error) ? error : size;
 257 }
 258
 259
 260 /**
 261  * gfs2_dir_read_data - Read a data from a directory inode
 262  * @ip: The GFS2 Inode
 263  * @buf: The buffer to place result into
 264  * @offset: File offset to begin jdata_readng from
 265  * @size: Amount of data to transfer
 266  *
 267  * Returns: The amount of data actually copied or the error
 268  */
 269 static int gfs2_dir_read_data(struct gfs2_inode *ip, char *buf, u64 offset,
 270                               unsigned int size, unsigned ra)
 271 {
 272         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 273         u64 lblock, dblock;
 274         u32 extlen = 0;
 275         unsigned int o;
 276         int copied = 0;
 277         int error = 0;
 278
 279         if (offset >= ip->i_disksize)
 280                 return 0;
 281
 282         if (offset + size > ip->i_disksize)
 283                 size = ip->i_disksize - offset;
 284
 285         if (!size)
 286                 return 0;
 287
 288         if (gfs2_is_stuffed(ip))
 289                 return gfs2_dir_read_stuffed(ip, buf, offset, size);
 290
 291         if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
 292                 return -EINVAL;
 293
 294         lblock = offset;
 295         o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
 296
 297         while (copied < size) {
 298                 unsigned int amount;
 299                 struct buffer_head *bh;
 300                 int new;
 301
 302                 amount = size - copied;
 303                 if (amount > sdp->sd_sb.sb_bsize - o)
 304                         amount = sdp->sd_sb.sb_bsize - o;
 305
 306                 if (!extlen) {
 307                         new = 0;
 308                         error = gfs2_extent_map(&ip->i_inode, lblock, &new,
 309                                                 &dblock, &extlen);
 310                         if (error || !dblock)
 311                                 goto fail;
 312                         BUG_ON(extlen < 1);
 313                         if (!ra)
 314                                 extlen = 1;
 315                         bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
 316                 } else {
 317                         error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, &bh);
 318                         if (error)
 319                                 goto fail;
 320                 }
 321                 error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD);
 322                 if (error) {
 323                         brelse(bh);
 324                         goto fail;
 325                 }
 326                 dblock++;
 327                 extlen--;
 328                 memcpy(buf, bh->b_data + o, amount);
 329                 brelse(bh);
 330                 buf += amount;
 331                 copied += amount;
 332                 lblock++;
 333                 o = sizeof(struct gfs2_meta_header);
 334         }
 335
 336         return copied;
 337 fail:
 338         return (copied) ? copied : error;
 339 }
 340
 341 static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent)
 342 {
 343         return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0;
 344 }
 345
 346 static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
 347                                      const struct qstr *name, int ret)
 348 {
 349         if (!gfs2_dirent_sentinel(dent) &&
 350             be32_to_cpu(dent->de_hash) == name->hash &&
 351             be16_to_cpu(dent->de_name_len) == name->len &&
 352             memcmp(dent+1, name->name, name->len) == 0)
 353                 return ret;
 354         return 0;
 355 }
 356
 357 static int gfs2_dirent_find(const struct gfs2_dirent *dent,
 358                             const struct qstr *name,
 359                             void *opaque)
 360 {
 361         return __gfs2_dirent_find(dent, name, 1);
 362 }
 363
 364 static int gfs2_dirent_prev(const struct gfs2_dirent *dent,
 365                             const struct qstr *name,
 366                             void *opaque)
 367 {
 368         return __gfs2_dirent_find(dent, name, 2);
 369 }
 370
 371 /*
 372  * name->name holds ptr to start of block.
 373  * name->len holds size of block.
 374  */
 375 static int gfs2_dirent_last(const struct gfs2_dirent *dent,
 376                             const struct qstr *name,
 377                             void *opaque)
 378 {
 379         const char *start = name->name;
 380         const char *end = (const char *)dent + be16_to_cpu(dent->de_rec_len);
 381         if (name->len == (end - start))
 382                 return 1;
 383         return 0;
 384 }
 385
 386 static int gfs2_dirent_find_space(const struct gfs2_dirent *dent,
 387                                   const struct qstr *name,
 388                                   void *opaque)
 389 {
 390         unsigned required = GFS2_DIRENT_SIZE(name->len);
 391         unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 392         unsigned totlen = be16_to_cpu(dent->de_rec_len);
 393
 394         if (gfs2_dirent_sentinel(dent))
 395                 actual = 0;
 396         if (totlen - actual >= required)
 397                 return 1;
 398         return 0;
 399 }
 400
 401 struct dirent_gather {
 402         const struct gfs2_dirent **pdent;
 403         unsigned offset;
 404 };
 405
 406 static int gfs2_dirent_gather(const struct gfs2_dirent *dent,
 407                               const struct qstr *name,
 408                               void *opaque)
 409 {
 410         struct dirent_gather *g = opaque;
 411         if (!gfs2_dirent_sentinel(dent)) {
 412                 g->pdent[g->offset++] = dent;
 413         }
 414         return 0;
 415 }
 416
 417 /*
 418  * Other possible things to check:
 419  * - Inode located within filesystem size (and on valid block)
 420  * - Valid directory entry type
 421  * Not sure how heavy-weight we want to make this... could also check
 422  * hash is correct for example, but that would take a lot of extra time.
 423  * For now the most important thing is to check that the various sizes
 424  * are correct.
 425  */
 426 static int gfs2_check_dirent(struct gfs2_dirent *dent, unsigned int offset,
 427                              unsigned int size, unsigned int len, int first)
 428 {
 429         const char *msg = "gfs2_dirent too small";
 430         if (unlikely(size < sizeof(struct gfs2_dirent)))
 431                 goto error;
 432         msg = "gfs2_dirent misaligned";
 433         if (unlikely(offset & 0x7))
 434                 goto error;
 435         msg = "gfs2_dirent points beyond end of block";
 436         if (unlikely(offset + size > len))
 437                 goto error;
 438         msg = "zero inode number";
 439         if (unlikely(!first && gfs2_dirent_sentinel(dent)))
 440                 goto error;
 441         msg = "name length is greater than space in dirent";
 442         if (!gfs2_dirent_sentinel(dent) &&
 443             unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
 444                      size))
 445                 goto error;
 446         return 0;
 447 error:
 448         printk(KERN_WARNING "gfs2_check_dirent: %s (%s)\n", msg,
 449                first ? "first in block" : "not first in block");
 450         return -EIO;
 451 }
 452
 453 static int gfs2_dirent_offset(const void *buf)
 454 {
 455         const struct gfs2_meta_header *h = buf;
 456         int offset;
 457
 458         BUG_ON(buf == NULL);
 459
 460         switch(be32_to_cpu(h->mh_type)) {
 461         case GFS2_METATYPE_LF:
 462                 offset = sizeof(struct gfs2_leaf);
 463                 break;
 464         case GFS2_METATYPE_DI:
 465                 offset = sizeof(struct gfs2_dinode);
 466                 break;
 467         default:
 468                 goto wrong_type;
 469         }
 470         return offset;
 471 wrong_type:
 472         printk(KERN_WARNING "gfs2_scan_dirent: wrong block type %u\n",
 473                be32_to_cpu(h->mh_type));
 474         return -1;
 475 }
 476
 477 static struct gfs2_dirent *gfs2_dirent_scan(struct inode *inode, void *buf,
 478                                             unsigned int len, gfs2_dscan_t scan,
 479                                             const struct qstr *name,
 480                                             void *opaque)
 481 {
 482         struct gfs2_dirent *dent, *prev;
 483         unsigned offset;
 484         unsigned size;
 485         int ret = 0;
 486
 487         ret = gfs2_dirent_offset(buf);
 488         if (ret < 0)
 489                 goto consist_inode;
 490
 491         offset = ret;
 492         prev = NULL;
 493         dent = buf + offset;
 494         size = be16_to_cpu(dent->de_rec_len);
 495         if (gfs2_check_dirent(dent, offset, size, len, 1))
 496                 goto consist_inode;
 497         do {
 498                 ret = scan(dent, name, opaque);
 499                 if (ret)
 500                         break;
 501                 offset += size;
 502                 if (offset == len)
 503                         break;
 504                 prev = dent;
 505                 dent = buf + offset;
 506                 size = be16_to_cpu(dent->de_rec_len);
 507                 if (gfs2_check_dirent(dent, offset, size, len, 0))
 508                         goto consist_inode;
 509         } while(1);
 510
 511         switch(ret) {
 512         case 0:
 513                 return NULL;
 514         case 1:
 515                 return dent;
 516         case 2:
 517                 return prev ? prev : dent;
 518         default:
 519                 BUG_ON(ret > 0);
 520                 return ERR_PTR(ret);
 521         }
 522
 523 consist_inode:
 524         gfs2_consist_inode(GFS2_I(inode));
 525         return ERR_PTR(-EIO);
 526 }
 527
 528 static int dirent_check_reclen(struct gfs2_inode *dip,
 529                                const struct gfs2_dirent *d, const void *end_p)
 530 {
 531         const void *ptr = d;
 532         u16 rec_len = be16_to_cpu(d->de_rec_len);
 533
 534         if (unlikely(rec_len < sizeof(struct gfs2_dirent)))
 535                 goto broken;
 536         ptr += rec_len;
 537         if (ptr < end_p)
 538                 return rec_len;
 539         if (ptr == end_p)
 540                 return -ENOENT;
 541 broken:
 542         gfs2_consist_inode(dip);
 543         return -EIO;
 544 }
 545
 546 /**
 547  * dirent_next - Next dirent
 548  * @dip: the directory
 549  * @bh: The buffer
 550  * @dent: Pointer to list of dirents
 551  *
 552  * Returns: 0 on success, error code otherwise
 553  */
 554
 555 static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh,
 556                        struct gfs2_dirent **dent)
 557 {
 558         struct gfs2_dirent *cur = *dent, *tmp;
 559         char *bh_end = bh->b_data + bh->b_size;
 560         int ret;
 561
 562         ret = dirent_check_reclen(dip, cur, bh_end);
 563         if (ret < 0)
 564                 return ret;
 565
 566         tmp = (void *)cur + ret;
 567         ret = dirent_check_reclen(dip, tmp, bh_end);
 568         if (ret == -EIO)
 569                 return ret;
 570
 571         /* Only the first dent could ever have de_inum.no_addr == 0 */
 572         if (gfs2_dirent_sentinel(tmp)) {
 573                 gfs2_consist_inode(dip);
 574                 return -EIO;
 575         }
 576
 577         *dent = tmp;
 578         return 0;
 579 }
 580
 581 /**
 582  * dirent_del - Delete a dirent
 583  * @dip: The GFS2 inode
 584  * @bh: The buffer
 585  * @prev: The previous dirent
 586  * @cur: The current dirent
 587  *
 588  */
 589
 590 static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh,
 591                        struct gfs2_dirent *prev, struct gfs2_dirent *cur)
 592 {
 593         u16 cur_rec_len, prev_rec_len;
 594
 595         if (gfs2_dirent_sentinel(cur)) {
 596                 gfs2_consist_inode(dip);
 597                 return;
 598         }
 599
 600         gfs2_trans_add_bh(dip->i_gl, bh, 1);
 601
 602         /* If there is no prev entry, this is the first entry in the block.
 603            The de_rec_len is already as big as it needs to be.  Just zero
 604            out the inode number and return.  */
 605
 606         if (!prev) {
 607                 cur->de_inum.no_addr = 0;
 608                 cur->de_inum.no_formal_ino = 0;
 609                 return;
 610         }
 611
 612         /*  Combine this dentry with the previous one.  */
 613
 614         prev_rec_len = be16_to_cpu(prev->de_rec_len);
 615         cur_rec_len = be16_to_cpu(cur->de_rec_len);
 616
 617         if ((char *)prev + prev_rec_len != (char *)cur)
 618                 gfs2_consist_inode(dip);
 619         if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size)
 620                 gfs2_consist_inode(dip);
 621
 622         prev_rec_len += cur_rec_len;
 623         prev->de_rec_len = cpu_to_be16(prev_rec_len);
 624 }
 625
 626 /*
 627  * Takes a dent from which to grab space as an argument. Returns the
 628  * newly created dent.
 629  */
 630 static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
 631                                             struct gfs2_dirent *dent,
 632                                             const struct qstr *name,
 633                                             struct buffer_head *bh)
 634 {
 635         struct gfs2_inode *ip = GFS2_I(inode);
 636         struct gfs2_dirent *ndent;
 637         unsigned offset = 0, totlen;
 638
 639         if (!gfs2_dirent_sentinel(dent))
 640                 offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 641         totlen = be16_to_cpu(dent->de_rec_len);
 642         BUG_ON(offset + name->len > totlen);
 643         gfs2_trans_add_bh(ip->i_gl, bh, 1);
 644         ndent = (struct gfs2_dirent *)((char *)dent + offset);
 645         dent->de_rec_len = cpu_to_be16(offset);
 646         gfs2_qstr2dirent(name, totlen - offset, ndent);
 647         return ndent;
 648 }
 649
 650 static struct gfs2_dirent *gfs2_dirent_alloc(struct inode *inode,
 651                                              struct buffer_head *bh,
 652                                              const struct qstr *name)
 653 {
 654         struct gfs2_dirent *dent;
 655         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 656                                 gfs2_dirent_find_space, name, NULL);
 657         if (!dent || IS_ERR(dent))
 658                 return dent;
 659         return gfs2_init_dirent(inode, dent, name, bh);
 660 }
 661
 662 static int get_leaf(struct gfs2_inode *dip, u64 leaf_no,
 663                     struct buffer_head **bhp)
 664 {
 665         int error;
 666
 667         error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, bhp);
 668         if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) {
 669                 /* printk(KERN_INFO "block num=%llu\n", leaf_no); */
 670                 error = -EIO;
 671         }
 672
 673         return error;
 674 }
 675
 676 /**
 677  * get_leaf_nr - Get a leaf number associated with the index
 678  * @dip: The GFS2 inode
 679  * @index:
 680  * @leaf_out:
 681  *
 682  * Returns: 0 on success, error code otherwise
 683  */
 684
 685 static int get_leaf_nr(struct gfs2_inode *dip, u32 index,
 686                        u64 *leaf_out)
 687 {
 688         __be64 leaf_no;
 689         int error;
 690
 691         error = gfs2_dir_read_data(dip, (char *)&leaf_no,
 692                                     index * sizeof(__be64),
 693                                     sizeof(__be64), 0);
 694         if (error != sizeof(u64))
 695                 return (error < 0) ? error : -EIO;
 696
 697         *leaf_out = be64_to_cpu(leaf_no);
 698
 699         return 0;
 700 }
 701
 702 static int get_first_leaf(struct gfs2_inode *dip, u32 index,
 703                           struct buffer_head **bh_out)
 704 {
 705         u64 leaf_no;
 706         int error;
 707
 708         error = get_leaf_nr(dip, index, &leaf_no);
 709         if (!error)
 710                 error = get_leaf(dip, leaf_no, bh_out);
 711
 712         return error;
 713 }
 714
 715 static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
 716                                               const struct qstr *name,
 717                                               gfs2_dscan_t scan,
 718                                               struct buffer_head **pbh)
 719 {
 720         struct buffer_head *bh;
 721         struct gfs2_dirent *dent;
 722         struct gfs2_inode *ip = GFS2_I(inode);
 723         int error;
 724
 725         if (ip->i_diskflags & GFS2_DIF_EXHASH) {
 726                 struct gfs2_leaf *leaf;
 727                 unsigned hsize = 1 << ip->i_depth;
 728                 unsigned index;
 729                 u64 ln;
 730                 if (hsize * sizeof(u64) != ip->i_disksize) {
 731                         gfs2_consist_inode(ip);
 732                         return ERR_PTR(-EIO);
 733                 }
 734
 735                 index = name->hash >> (32 - ip->i_depth);
 736                 error = get_first_leaf(ip, index, &bh);
 737                 if (error)
 738                         return ERR_PTR(error);
 739                 do {
 740                         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 741                                                 scan, name, NULL);
 742                         if (dent)
 743                                 goto got_dent;
 744                         leaf = (struct gfs2_leaf *)bh->b_data;
 745                         ln = be64_to_cpu(leaf->lf_next);
 746                         brelse(bh);
 747                         if (!ln)
 748                                 break;
 749
 750                         error = get_leaf(ip, ln, &bh);
 751                 } while(!error);
 752
 753                 return error ? ERR_PTR(error) : NULL;
 754         }
 755
 756
 757         error = gfs2_meta_inode_buffer(ip, &bh);
 758         if (error)
 759                 return ERR_PTR(error);
 760         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
 761 got_dent:
 762         if (unlikely(dent == NULL || IS_ERR(dent))) {
 763                 brelse(bh);
 764                 bh = NULL;
 765         }
 766         *pbh = bh;
 767         return dent;
 768 }
 769
 770 static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
 771 {
 772         struct gfs2_inode *ip = GFS2_I(inode);
 773         unsigned int n = 1;
 774         u64 bn;
 775         int error;
 776         struct buffer_head *bh;
 777         struct gfs2_leaf *leaf;
 778         struct gfs2_dirent *dent;
 779         struct qstr name = { .name = "", .len = 0, .hash = 0 };
 780
 781         error = gfs2_alloc_block(ip, &bn, &n);
 782         if (error)
 783                 return NULL;
 784         bh = gfs2_meta_new(ip->i_gl, bn);
 785         if (!bh)
 786                 return NULL;
 787
 788         gfs2_trans_add_unrevoke(GFS2_SB(inode), bn, 1);
 789         gfs2_trans_add_bh(ip->i_gl, bh, 1);
 790         gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF);
 791         leaf = (struct gfs2_leaf *)bh->b_data;
 792         leaf->lf_depth = cpu_to_be16(depth);
 793         leaf->lf_entries = 0;
 794         leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
 795         leaf->lf_next = 0;
 796         memset(leaf->lf_reserved, 0, sizeof(leaf->lf_reserved));
 797         dent = (struct gfs2_dirent *)(leaf+1);
 798         gfs2_qstr2dirent(&name, bh->b_size - sizeof(struct gfs2_leaf), dent);
 799         *pbh = bh;
 800         return leaf;
 801 }
 802
 803 /**
 804  * dir_make_exhash - Convert a stuffed directory into an ExHash directory
 805  * @dip: The GFS2 inode
 806  *
 807  * Returns: 0 on success, error code otherwise
 808  */
 809
 810 static int dir_make_exhash(struct inode *inode)
 811 {
 812         struct gfs2_inode *dip = GFS2_I(inode);
 813         struct gfs2_sbd *sdp = GFS2_SB(inode);
 814         struct gfs2_dirent *dent;
 815         struct qstr args;
 816         struct buffer_head *bh, *dibh;
 817         struct gfs2_leaf *leaf;
 818         int y;
 819         u32 x;
 820         __be64 *lp;
 821         u64 bn;
 822         int error;
 823
 824         error = gfs2_meta_inode_buffer(dip, &dibh);
 825         if (error)
 826                 return error;
 827
 828         /*  Turn over a new leaf  */
 829
 830         leaf = new_leaf(inode, &bh, 0);
 831         if (!leaf)
 832                 return -ENOSPC;
 833         bn = bh->b_blocknr;
 834
 835         gfs2_assert(sdp, dip->i_entries < (1 << 16));
 836         leaf->lf_entries = cpu_to_be16(dip->i_entries);
 837
 838         /*  Copy dirents  */
 839
 840         gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
 841                              sizeof(struct gfs2_dinode));
 842
 843         /*  Find last entry  */
 844
 845         x = 0;
 846         args.len = bh->b_size - sizeof(struct gfs2_dinode) +
 847                    sizeof(struct gfs2_leaf);
 848         args.name = bh->b_data;
 849         dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size,
 850                                 gfs2_dirent_last, &args, NULL);
 851         if (!dent) {
 852                 brelse(bh);
 853                 brelse(dibh);
 854                 return -EIO;
 855         }
 856         if (IS_ERR(dent)) {
 857                 brelse(bh);
 858                 brelse(dibh);
 859                 return PTR_ERR(dent);
 860         }
 861
 862         /*  Adjust the last dirent's record length
 863            (Remember that dent still points to the last entry.)  */
 864
 865         dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
 866                 sizeof(struct gfs2_dinode) -
 867                 sizeof(struct gfs2_leaf));
 868
 869         brelse(bh);
 870
 871         /*  We're done with the new leaf block, now setup the new
 872             hash table.  */
 873
 874         gfs2_trans_add_bh(dip->i_gl, dibh, 1);
 875         gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
 876
 877         lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
 878
 879         for (x = sdp->sd_hash_ptrs; x--; lp++)
 880                 *lp = cpu_to_be64(bn);
 881
 882         dip->i_disksize = sdp->sd_sb.sb_bsize / 2;
 883         gfs2_add_inode_blocks(&dip->i_inode, 1);
 884         dip->i_diskflags |= GFS2_DIF_EXHASH;
 885
 886         for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
 887         dip->i_depth = y;
 888
 889         gfs2_dinode_out(dip, dibh->b_data);
 890
 891         brelse(dibh);
 892
 893         return 0;
 894 }
 895
 896 /**
 897  * dir_split_leaf - Split a leaf block into two
 898  * @dip: The GFS2 inode
 899  * @index:
 900  * @leaf_no:
 901  *
 902  * Returns: 0 on success, error code on failure
 903  */
 904
 905 static int dir_split_leaf(struct inode *inode, const struct qstr *name)
 906 {
 907         struct gfs2_inode *dip = GFS2_I(inode);
 908         struct buffer_head *nbh, *obh, *dibh;
 909         struct gfs2_leaf *nleaf, *oleaf;
 910         struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new;
 911         u32 start, len, half_len, divider;
 912         u64 bn, leaf_no;
 913         __be64 *lp;
 914         u32 index;
 915         int x, moved = 0;
 916         int error;
 917
 918         index = name->hash >> (32 - dip->i_depth);
 919         error = get_leaf_nr(dip, index, &leaf_no);
 920         if (error)
 921                 return error;
 922
 923         /*  Get the old leaf block  */
 924         error = get_leaf(dip, leaf_no, &obh);
 925         if (error)
 926                 return error;
 927
 928         oleaf = (struct gfs2_leaf *)obh->b_data;
 929         if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
 930                 brelse(obh);
 931                 return 1; /* can't split */
 932         }
 933
 934         gfs2_trans_add_bh(dip->i_gl, obh, 1);
 935
 936         nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
 937         if (!nleaf) {
 938                 brelse(obh);
 939                 return -ENOSPC;
 940         }
 941         bn = nbh->b_blocknr;
 942
 943         /*  Compute the start and len of leaf pointers in the hash table.  */
 944         len = 1 << (dip->i_depth - be16_to_cpu(oleaf->lf_depth));
 945         half_len = len >> 1;
 946         if (!half_len) {
 947                 printk(KERN_WARNING "i_depth %u lf_depth %u index %u\n", dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
 948                 gfs2_consist_inode(dip);
 949                 error = -EIO;
 950                 goto fail_brelse;
 951         }
 952
 953         start = (index & ~(len - 1));
 954
 955         /* Change the pointers.
 956            Don't bother distinguishing stuffed from non-stuffed.
 957            This code is complicated enough already. */
 958         lp = kmalloc(half_len * sizeof(__be64), GFP_NOFS);
 959         if (!lp) {
 960                 error = -ENOMEM;
 961                 goto fail_brelse;
 962         }
 963
 964         /*  Change the pointers  */
 965         for (x = 0; x < half_len; x++)
 966                 lp[x] = cpu_to_be64(bn);
 967
 968         error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64),
 969                                     half_len * sizeof(u64));
 970         if (error != half_len * sizeof(u64)) {
 971                 if (error >= 0)
 972                         error = -EIO;
 973                 goto fail_lpfree;
 974         }
 975
 976         kfree(lp);
 977
 978         /*  Compute the divider  */
 979         divider = (start + half_len) << (32 - dip->i_depth);
 980
 981         /*  Copy the entries  */
 982         dent = (struct gfs2_dirent *)(obh->b_data + sizeof(struct gfs2_leaf));
 983
 984         do {
 985                 next = dent;
 986                 if (dirent_next(dip, obh, &next))
 987                         next = NULL;
 988
 989                 if (!gfs2_dirent_sentinel(dent) &&
 990                     be32_to_cpu(dent->de_hash) < divider) {
 991                         struct qstr str;
 992                         str.name = (char*)(dent+1);
 993                         str.len = be16_to_cpu(dent->de_name_len);
 994                         str.hash = be32_to_cpu(dent->de_hash);
 995                         new = gfs2_dirent_alloc(inode, nbh, &str);
 996                         if (IS_ERR(new)) {
 997                                 error = PTR_ERR(new);
 998                                 break;
 999                         }
1000
1001                         new->de_inum = dent->de_inum; /* No endian worries */
1002                         new->de_type = dent->de_type; /* No endian worries */
1003                         be16_add_cpu(&nleaf->lf_entries, 1);
1004
1005                         dirent_del(dip, obh, prev, dent);
1006
1007                         if (!oleaf->lf_entries)
1008                                 gfs2_consist_inode(dip);
1009                         be16_add_cpu(&oleaf->lf_entries, -1);
1010
1011                         if (!prev)
1012                                 prev = dent;
1013
1014                         moved = 1;
1015                 } else {
1016                         prev = dent;
1017                 }
1018                 dent = next;
1019         } while (dent);
1020
1021         oleaf->lf_depth = nleaf->lf_depth;
1022
1023         error = gfs2_meta_inode_buffer(dip, &dibh);
1024         if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) {
1025                 gfs2_trans_add_bh(dip->i_gl, dibh, 1);
1026                 gfs2_add_inode_blocks(&dip->i_inode, 1);
1027                 gfs2_dinode_out(dip, dibh->b_data);
1028                 brelse(dibh);
1029         }
1030
1031         brelse(obh);
1032         brelse(nbh);
1033
1034         return error;
1035
1036 fail_lpfree:
1037         kfree(lp);
1038
1039 fail_brelse:
1040         brelse(obh);
1041         brelse(nbh);
1042         return error;
1043 }
1044
1045 /**
1046  * dir_double_exhash - Double size of ExHash table
1047  * @dip: The GFS2 dinode
1048  *
1049  * Returns: 0 on success, error code on failure
1050  */
1051
1052 static int dir_double_exhash(struct gfs2_inode *dip)
1053 {
1054         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1055         struct buffer_head *dibh;
1056         u32 hsize;
1057         u64 *buf;
1058         u64 *from, *to;
1059         u64 block;
1060         int x;
1061         int error = 0;
1062
1063         hsize = 1 << dip->i_depth;
1064         if (hsize * sizeof(u64) != dip->i_disksize) {
1065                 gfs2_consist_inode(dip);
1066                 return -EIO;
1067         }
1068
1069         /*  Allocate both the "from" and "to" buffers in one big chunk  */
1070
1071         buf = kcalloc(3, sdp->sd_hash_bsize, GFP_NOFS);
1072         if (!buf)
1073                 return -ENOMEM;
1074
1075         for (block = dip->i_disksize >> sdp->sd_hash_bsize_shift; block--;) {
1076                 error = gfs2_dir_read_data(dip, (char *)buf,
1077                                             block * sdp->sd_hash_bsize,
1078                                             sdp->sd_hash_bsize, 1);
1079                 if (error != sdp->sd_hash_bsize) {
1080                         if (error >= 0)
1081                                 error = -EIO;
1082                         goto fail;
1083                 }
1084
1085                 from = buf;
1086                 to = (u64 *)((char *)buf + sdp->sd_hash_bsize);
1087
1088                 for (x = sdp->sd_hash_ptrs; x--; from++) {
1089                         *to++ = *from;  /*  No endianess worries  */
1090                         *to++ = *from;
1091                 }
1092
1093                 error = gfs2_dir_write_data(dip,
1094                                              (char *)buf + sdp->sd_hash_bsize,
1095                                              block * sdp->sd_sb.sb_bsize,
1096                                              sdp->sd_sb.sb_bsize);
1097                 if (error != sdp->sd_sb.sb_bsize) {
1098                         if (error >= 0)
1099                                 error = -EIO;
1100                         goto fail;
1101                 }
1102         }
1103
1104         kfree(buf);
1105
1106         error = gfs2_meta_inode_buffer(dip, &dibh);
1107         if (!gfs2_assert_withdraw(sdp, !error)) {
1108                 dip->i_depth++;
1109                 gfs2_dinode_out(dip, dibh->b_data);
1110                 brelse(dibh);
1111         }
1112
1113         return error;
1114
1115 fail:
1116         kfree(buf);
1117         return error;
1118 }
1119
1120 /**
1121  * compare_dents - compare directory entries by hash value
1122  * @a: first dent
1123  * @b: second dent
1124  *
1125  * When comparing the hash entries of @a to @b:
1126  *   gt: returns 1
1127  *   lt: returns -1
1128  *   eq: returns 0
1129  */
1130
1131 static int compare_dents(const void *a, const void *b)
1132 {
1133         const struct gfs2_dirent *dent_a, *dent_b;
1134         u32 hash_a, hash_b;
1135         int ret = 0;
1136
1137         dent_a = *(const struct gfs2_dirent **)a;
1138         hash_a = be32_to_cpu(dent_a->de_hash);
1139
1140         dent_b = *(const struct gfs2_dirent **)b;
1141         hash_b = be32_to_cpu(dent_b->de_hash);
1142
1143         if (hash_a > hash_b)
1144                 ret = 1;
1145         else if (hash_a < hash_b)
1146                 ret = -1;
1147         else {
1148                 unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
1149                 unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
1150
1151                 if (len_a > len_b)
1152                         ret = 1;
1153                 else if (len_a < len_b)
1154                         ret = -1;
1155                 else
1156                         ret = memcmp(dent_a + 1, dent_b + 1, len_a);
1157         }
1158
1159         return ret;
1160 }
1161
1162 /**
1163  * do_filldir_main - read out directory entries
1164  * @dip: The GFS2 inode
1165  * @offset: The offset in the file to read from
1166  * @opaque: opaque data to pass to filldir
1167  * @filldir: The function to pass entries to
1168  * @darr: an array of struct gfs2_dirent pointers to read
1169  * @entries: the number of entries in darr
1170  * @copied: pointer to int that's non-zero if a entry has been copied out
1171  *
1172  * Jump through some hoops to make sure that if there are hash collsions,
1173  * they are read out at the beginning of a buffer.  We want to minimize
1174  * the possibility that they will fall into different readdir buffers or
1175  * that someone will want to seek to that location.
1176  *
1177  * Returns: errno, >0 on exception from filldir
1178  */
1179
1180 static int do_filldir_main(struct gfs2_inode *dip, u64 *offset,
1181                            void *opaque, filldir_t filldir,
1182                            const struct gfs2_dirent **darr, u32 entries,
1183                            int *copied)
1184 {
1185         const struct gfs2_dirent *dent, *dent_next;
1186         u64 off, off_next;
1187         unsigned int x, y;
1188         int run = 0;
1189         int error = 0;
1190
1191         sort(darr, entries, sizeof(struct gfs2_dirent *), compare_dents, NULL);
1192
1193         dent_next = darr[0];
1194         off_next = be32_to_cpu(dent_next->de_hash);
1195         off_next = gfs2_disk_hash2offset(off_next);
1196
1197         for (x = 0, y = 1; x < entries; x++, y++) {
1198                 dent = dent_next;
1199                 off = off_next;
1200
1201                 if (y < entries) {
1202                         dent_next = darr[y];
1203                         off_next = be32_to_cpu(dent_next->de_hash);
1204                         off_next = gfs2_disk_hash2offset(off_next);
1205
1206                         if (off < *offset)
1207                                 continue;
1208                         *offset = off;
1209
1210                         if (off_next == off) {
1211                                 if (*copied && !run)
1212                                         return 1;
1213                                 run = 1;
1214                         } else
1215                                 run = 0;
1216                 } else {
1217                         if (off < *offset)
1218                                 continue;
1219                         *offset = off;
1220                 }
1221
1222                 error = filldir(opaque, (const char *)(dent + 1),
1223                                 be16_to_cpu(dent->de_name_len),
1224                                 off, be64_to_cpu(dent->de_inum.no_addr),
1225                                 be16_to_cpu(dent->de_type));
1226                 if (error)
1227                         return 1;
1228
1229                 *copied = 1;
1230         }
1231
1232         /* Increment the *offset by one, so the next time we come into the
1233            do_filldir fxn, we get the next entry instead of the last one in the
1234            current leaf */
1235
1236         (*offset)++;
1237
1238         return 0;
1239 }
1240
1241 static void *gfs2_alloc_sort_buffer(unsigned size)
1242 {
1243         void *ptr = NULL;
1244
1245         if (size < KMALLOC_MAX_SIZE)
1246                 ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN);
1247         if (!ptr)
1248                 ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL);
1249         return ptr;
1250 }
1251
1252 static void gfs2_free_sort_buffer(void *ptr)
1253 {
1254         if (is_vmalloc_addr(ptr))
1255                 vfree(ptr);
1256         else
1257                 kfree(ptr);
1258 }
1259
1260 static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
1261                               filldir_t filldir, int *copied, unsigned *depth,
1262                               u64 leaf_no)
1263 {
1264         struct gfs2_inode *ip = GFS2_I(inode);
1265         struct gfs2_sbd *sdp = GFS2_SB(inode);
1266         struct buffer_head *bh;
1267         struct gfs2_leaf *lf;
1268         unsigned entries = 0, entries2 = 0;
1269         unsigned leaves = 0;
1270         const struct gfs2_dirent **darr, *dent;
1271         struct dirent_gather g;
1272         struct buffer_head **larr;
1273         int leaf = 0;
1274         int error, i;
1275         u64 lfn = leaf_no;
1276
1277         do {
1278                 error = get_leaf(ip, lfn, &bh);
1279                 if (error)
1280                         goto out;
1281                 lf = (struct gfs2_leaf *)bh->b_data;
1282                 if (leaves == 0)
1283                         *depth = be16_to_cpu(lf->lf_depth);
1284                 entries += be16_to_cpu(lf->lf_entries);
1285                 leaves++;
1286                 lfn = be64_to_cpu(lf->lf_next);
1287                 brelse(bh);
1288         } while(lfn);
1289
1290         if (!entries)
1291                 return 0;
1292
1293         error = -ENOMEM;
1294         /*
1295          * The extra 99 entries are not normally used, but are a buffer
1296          * zone in case the number of entries in the leaf is corrupt.
1297          * 99 is the maximum number of entries that can fit in a single
1298          * leaf block.
1299          */
1300         larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *));
1301         if (!larr)
1302                 goto out;
1303         darr = (const struct gfs2_dirent **)(larr + leaves);
1304         g.pdent = darr;
1305         g.offset = 0;
1306         lfn = leaf_no;
1307
1308         do {
1309                 error = get_leaf(ip, lfn, &bh);
1310                 if (error)
1311                         goto out_free;
1312                 lf = (struct gfs2_leaf *)bh->b_data;
1313                 lfn = be64_to_cpu(lf->lf_next);
1314                 if (lf->lf_entries) {
1315                         entries2 += be16_to_cpu(lf->lf_entries);
1316                         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
1317                                                 gfs2_dirent_gather, NULL, &g);
1318                         error = PTR_ERR(dent);
1319                         if (IS_ERR(dent))
1320                                 goto out_free;
1321                         if (entries2 != g.offset) {
1322                                 fs_warn(sdp, "Number of entries corrupt in dir "
1323                                                 "leaf %llu, entries2 (%u) != "
1324                                                 "g.offset (%u)\n",
1325                                         (unsigned long long)bh->b_blocknr,
1326                                         entries2, g.offset);
1327
1328                                 error = -EIO;
1329                                 goto out_free;
1330                         }
1331                         error = 0;
1332                         larr[leaf++] = bh;
1333                 } else {
1334                         brelse(bh);
1335                 }
1336         } while(lfn);
1337
1338         BUG_ON(entries2 != entries);
1339         error = do_filldir_main(ip, offset, opaque, filldir, darr,
1340                                 entries, copied);
1341 out_free:
1342         for(i = 0; i < leaf; i++)
1343                 brelse(larr[i]);
1344         gfs2_free_sort_buffer(larr);
1345 out:
1346         return error;
1347 }
1348
1349 /**
1350  * dir_e_read - Reads the entries from a directory into a filldir buffer
1351  * @dip: dinode pointer
1352  * @offset: the hash of the last entry read shifted to the right once
1353  * @opaque: buffer for the filldir function to fill
1354  * @filldir: points to the filldir function to use
1355  *
1356  * Returns: errno
1357  */
1358
1359 static int dir_e_read(struct inode *inode, u64 *offset, void *opaque,
1360                       filldir_t filldir)
1361 {
1362         struct gfs2_inode *dip = GFS2_I(inode);
1363         struct gfs2_sbd *sdp = GFS2_SB(inode);
1364         u32 hsize, len = 0;
1365         u32 ht_offset, lp_offset, ht_offset_cur = -1;
1366         u32 hash, index;
1367         __be64 *lp;
1368         int copied = 0;
1369         int error = 0;
1370         unsigned depth = 0;
1371
1372         hsize = 1 << dip->i_depth;
1373         if (hsize * sizeof(u64) != dip->i_disksize) {
1374                 gfs2_consist_inode(dip);
1375                 return -EIO;
1376         }
1377
1378         hash = gfs2_dir_offset2hash(*offset);
1379         index = hash >> (32 - dip->i_depth);
1380
1381         lp = kmalloc(sdp->sd_hash_bsize, GFP_NOFS);
1382         if (!lp)
1383                 return -ENOMEM;
1384
1385         while (index < hsize) {
1386                 lp_offset = index & (sdp->sd_hash_ptrs - 1);
1387                 ht_offset = index - lp_offset;
1388
1389                 if (ht_offset_cur != ht_offset) {
1390                         error = gfs2_dir_read_data(dip, (char *)lp,
1391                                                 ht_offset * sizeof(__be64),
1392                                                 sdp->sd_hash_bsize, 1);
1393                         if (error != sdp->sd_hash_bsize) {
1394                                 if (error >= 0)
1395                                         error = -EIO;
1396                                 goto out;
1397                         }
1398                         ht_offset_cur = ht_offset;
1399                 }
1400
1401                 error = gfs2_dir_read_leaf(inode, offset, opaque, filldir,
1402                                            &copied, &depth,
1403                                            be64_to_cpu(lp[lp_offset]));
1404                 if (error)
1405                         break;
1406
1407                 len = 1 << (dip->i_depth - depth);
1408                 index = (index & ~(len - 1)) + len;
1409         }
1410
1411 out:
1412         kfree(lp);
1413         if (error > 0)
1414                 error = 0;
1415         return error;
1416 }
1417
1418 int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque,
1419                   filldir_t filldir)
1420 {
1421         struct gfs2_inode *dip = GFS2_I(inode);
1422         struct gfs2_sbd *sdp = GFS2_SB(inode);
1423         struct dirent_gather g;
1424         const struct gfs2_dirent **darr, *dent;
1425         struct buffer_head *dibh;
1426         int copied = 0;
1427         int error;
1428
1429         if (!dip->i_entries)
1430                 return 0;
1431
1432         if (dip->i_diskflags & GFS2_DIF_EXHASH)
1433                 return dir_e_read(inode, offset, opaque, filldir);
1434
1435         if (!gfs2_is_stuffed(dip)) {
1436                 gfs2_consist_inode(dip);
1437                 return -EIO;
1438         }
1439
1440         error = gfs2_meta_inode_buffer(dip, &dibh);
1441         if (error)
1442                 return error;
1443
1444         error = -ENOMEM;
1445         /* 96 is max number of dirents which can be stuffed into an inode */
1446         darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_NOFS);
1447         if (darr) {
1448                 g.pdent = darr;
1449                 g.offset = 0;
1450                 dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size,
1451                                         gfs2_dirent_gather, NULL, &g);
1452                 if (IS_ERR(dent)) {
1453                         error = PTR_ERR(dent);
1454                         goto out;
1455                 }
1456                 if (dip->i_entries != g.offset) {
1457                         fs_warn(sdp, "Number of entries corrupt in dir %llu, "
1458                                 "ip->i_entries (%u) != g.offset (%u)\n",
1459                                 (unsigned long long)dip->i_no_addr,
1460                                 dip->i_entries,
1461                                 g.offset);
1462                         error = -EIO;
1463                         goto out;
1464                 }
1465                 error = do_filldir_main(dip, offset, opaque, filldir, darr,
1466                                         dip->i_entries, &copied);
1467 out:
1468                 kfree(darr);
1469         }
1470
1471         if (error > 0)
1472                 error = 0;
1473
1474         brelse(dibh);
1475
1476         return error;
1477 }
1478
1479 /**
1480  * gfs2_dir_search - Search a directory
1481  * @dip: The GFS2 inode
1482  * @filename:
1483  * @inode:
1484  *
1485  * This routine searches a directory for a file or another directory.
1486  * Assumes a glock is held on dip.
1487  *
1488  * Returns: errno
1489  */
1490
1491 struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name)
1492 {
1493         struct buffer_head *bh;
1494         struct gfs2_dirent *dent;
1495         struct inode *inode;
1496
1497         dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1498         if (dent) {
1499                 if (IS_ERR(dent))
1500                         return ERR_CAST(dent);
1501                 inode = gfs2_inode_lookup(dir->i_sb,
1502                                 be16_to_cpu(dent->de_type),
1503                                 be64_to_cpu(dent->de_inum.no_addr),
1504                                 be64_to_cpu(dent->de_inum.no_formal_ino));
1505                 brelse(bh);
1506                 return inode;
1507         }
1508         return ERR_PTR(-ENOENT);
1509 }
1510
1511 int gfs2_dir_check(struct inode *dir, const struct qstr *name,
1512                    const struct gfs2_inode *ip)
1513 {
1514         struct buffer_head *bh;
1515         struct gfs2_dirent *dent;
1516         int ret = -ENOENT;
1517
1518         dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1519         if (dent) {
1520                 if (IS_ERR(dent))
1521                         return PTR_ERR(dent);
1522                 if (ip) {
1523                         if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
1524                                 goto out;
1525                         if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
1526                             ip->i_no_formal_ino)
1527                                 goto out;
1528                         if (unlikely(IF2DT(ip->i_inode.i_mode) !=
1529                             be16_to_cpu(dent->de_type))) {
1530                                 gfs2_consist_inode(GFS2_I(dir));
1531                                 ret = -EIO;
1532                                 goto out;
1533                         }
1534                 }
1535                 ret = 0;
1536 out:
1537                 brelse(bh);
1538         }
1539         return ret;
1540 }
1541
1542 static int dir_new_leaf(struct inode *inode, const struct qstr *name)
1543 {
1544         struct buffer_head *bh, *obh;
1545         struct gfs2_inode *ip = GFS2_I(inode);
1546         struct gfs2_leaf *leaf, *oleaf;
1547         int error;
1548         u32 index;
1549         u64 bn;
1550
1551         index = name->hash >> (32 - ip->i_depth);
1552         error = get_first_leaf(ip, index, &obh);
1553         if (error)
1554                 return error;
1555         do {
1556                 oleaf = (struct gfs2_leaf *)obh->b_data;
1557                 bn = be64_to_cpu(oleaf->lf_next);
1558                 if (!bn)
1559                         break;
1560                 brelse(obh);
1561                 error = get_leaf(ip, bn, &obh);
1562                 if (error)
1563                         return error;
1564         } while(1);
1565
1566         gfs2_trans_add_bh(ip->i_gl, obh, 1);
1567
1568         leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
1569         if (!leaf) {
1570                 brelse(obh);
1571                 return -ENOSPC;
1572         }
1573         oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
1574         brelse(bh);
1575         brelse(obh);
1576
1577         error = gfs2_meta_inode_buffer(ip, &bh);
1578         if (error)
1579                 return error;
1580         gfs2_trans_add_bh(ip->i_gl, bh, 1);
1581         gfs2_add_inode_blocks(&ip->i_inode, 1);
1582         gfs2_dinode_out(ip, bh->b_data);
1583         brelse(bh);
1584         return 0;
1585 }
1586
1587 /**
1588  * gfs2_dir_add - Add new filename into directory
1589  * @dip: The GFS2 inode
1590  * @filename: The new name
1591  * @inode: The inode number of the entry
1592  * @type: The type of the entry
1593  *
1594  * Returns: 0 on success, error code on failure
1595  */
1596
1597 int gfs2_dir_add(struct inode *inode, const struct qstr *name,
1598                  const struct gfs2_inode *nip, unsigned type)
1599 {
1600         struct gfs2_inode *ip = GFS2_I(inode);
1601         struct buffer_head *bh;
1602         struct gfs2_dirent *dent;
1603         struct gfs2_leaf *leaf;
1604         int error;
1605
1606         while(1) {
1607                 dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space,
1608                                           &bh);
1609                 if (dent) {
1610                         if (IS_ERR(dent))
1611                                 return PTR_ERR(dent);
1612                         dent = gfs2_init_dirent(inode, dent, name, bh);
1613                         gfs2_inum_out(nip, dent);
1614                         dent->de_type = cpu_to_be16(type);
1615                         if (ip->i_diskflags & GFS2_DIF_EXHASH) {
1616                                 leaf = (struct gfs2_leaf *)bh->b_data;
1617                                 be16_add_cpu(&leaf->lf_entries, 1);
1618                         }
1619                         brelse(bh);
1620                         error = gfs2_meta_inode_buffer(ip, &bh);
1621                         if (error)
1622                                 break;
1623                         gfs2_trans_add_bh(ip->i_gl, bh, 1);
1624                         ip->i_entries++;
1625                         ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
1626                         gfs2_dinode_out(ip, bh->b_data);
1627                         brelse(bh);
1628                         error = 0;
1629                         break;
1630                 }
1631                 if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) {
1632                         error = dir_make_exhash(inode);
1633                         if (error)
1634                                 break;
1635                         continue;
1636                 }
1637                 error = dir_split_leaf(inode, name);
1638                 if (error == 0)
1639                         continue;
1640                 if (error < 0)
1641                         break;
1642                 if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
1643                         error = dir_double_exhash(ip);
1644                         if (error)
1645                                 break;
1646                         error = dir_split_leaf(inode, name);
1647                         if (error < 0)
1648                                 break;
1649                         if (error == 0)
1650                                 continue;
1651                 }
1652                 error = dir_new_leaf(inode, name);
1653                 if (!error)
1654                         continue;
1655                 error = -ENOSPC;
1656                 break;
1657         }
1658         return error;
1659 }
1660
1661
1662 /**
1663  * gfs2_dir_del - Delete a directory entry
1664  * @dip: The GFS2 inode
1665  * @filename: The filename
1666  *
1667  * Returns: 0 on success, error code on failure
1668  */
1669
1670 int gfs2_dir_del(struct gfs2_inode *dip, const struct qstr *name)
1671 {
1672         struct gfs2_dirent *dent, *prev = NULL;
1673         struct buffer_head *bh;
1674         int error;
1675
1676         /* Returns _either_ the entry (if its first in block) or the
1677            previous entry otherwise */
1678         dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh);
1679         if (!dent) {
1680                 gfs2_consist_inode(dip);
1681                 return -EIO;
1682         }
1683         if (IS_ERR(dent)) {
1684                 gfs2_consist_inode(dip);
1685                 return PTR_ERR(dent);
1686         }
1687         /* If not first in block, adjust pointers accordingly */
1688         if (gfs2_dirent_find(dent, name, NULL) == 0) {
1689                 prev = dent;
1690                 dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
1691         }
1692
1693         dirent_del(dip, bh, prev, dent);
1694         if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1695                 struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
1696                 u16 entries = be16_to_cpu(leaf->lf_entries);
1697                 if (!entries)
1698                         gfs2_consist_inode(dip);
1699                 leaf->lf_entries = cpu_to_be16(--entries);
1700         }
1701         brelse(bh);
1702
1703         error = gfs2_meta_inode_buffer(dip, &bh);
1704         if (error)
1705                 return error;
1706
1707         if (!dip->i_entries)
1708                 gfs2_consist_inode(dip);
1709         gfs2_trans_add_bh(dip->i_gl, bh, 1);
1710         dip->i_entries--;
1711         dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1712         gfs2_dinode_out(dip, bh->b_data);
1713         brelse(bh);
1714         mark_inode_dirty(&dip->i_inode);
1715
1716         return error;
1717 }
1718
1719 /**
1720  * gfs2_dir_mvino - Change inode number of directory entry
1721  * @dip: The GFS2 inode
1722  * @filename:
1723  * @new_inode:
1724  *
1725  * This routine changes the inode number of a directory entry.  It's used
1726  * by rename to change ".." when a directory is moved.
1727  * Assumes a glock is held on dvp.
1728  *
1729  * Returns: errno
1730  */
1731
1732 int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
1733                    const struct gfs2_inode *nip, unsigned int new_type)
1734 {
1735         struct buffer_head *bh;
1736         struct gfs2_dirent *dent;
1737         int error;
1738
1739         dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh);
1740         if (!dent) {
1741                 gfs2_consist_inode(dip);
1742                 return -EIO;
1743         }
1744         if (IS_ERR(dent))
1745                 return PTR_ERR(dent);
1746
1747         gfs2_trans_add_bh(dip->i_gl, bh, 1);
1748         gfs2_inum_out(nip, dent);
1749         dent->de_type = cpu_to_be16(new_type);
1750
1751         if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1752                 brelse(bh);
1753                 error = gfs2_meta_inode_buffer(dip, &bh);
1754                 if (error)
1755                         return error;
1756                 gfs2_trans_add_bh(dip->i_gl, bh, 1);
1757         }
1758
1759         dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1760         gfs2_dinode_out(dip, bh->b_data);
1761         brelse(bh);
1762         return 0;
1763 }
1764
1765 /**
1766  * foreach_leaf - call a function for each leaf in a directory
1767  * @dip: the directory
1768  * @lc: the function to call for each each
1769  * @data: private data to pass to it
1770  *
1771  * Returns: errno
1772  */
1773
1774 static int foreach_leaf(struct gfs2_inode *dip, leaf_call_t lc, void *data)
1775 {
1776         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1777         struct buffer_head *bh;
1778         struct gfs2_leaf *leaf;
1779         u32 hsize, len;
1780         u32 ht_offset, lp_offset, ht_offset_cur = -1;
1781         u32 index = 0;
1782         __be64 *lp;
1783         u64 leaf_no;
1784         int error = 0;
1785
1786         hsize = 1 << dip->i_depth;
1787         if (hsize * sizeof(u64) != dip->i_disksize) {
1788                 gfs2_consist_inode(dip);
1789                 return -EIO;
1790         }
1791
1792         lp = kmalloc(sdp->sd_hash_bsize, GFP_NOFS);
1793         if (!lp)
1794                 return -ENOMEM;
1795
1796         while (index < hsize) {
1797                 lp_offset = index & (sdp->sd_hash_ptrs - 1);
1798                 ht_offset = index - lp_offset;
1799
1800                 if (ht_offset_cur != ht_offset) {
1801                         error = gfs2_dir_read_data(dip, (char *)lp,
1802                                                 ht_offset * sizeof(__be64),
1803                                                 sdp->sd_hash_bsize, 1);
1804                         if (error != sdp->sd_hash_bsize) {
1805                                 if (error >= 0)
1806                                         error = -EIO;
1807                                 goto out;
1808                         }
1809                         ht_offset_cur = ht_offset;
1810                 }
1811
1812                 leaf_no = be64_to_cpu(lp[lp_offset]);
1813                 if (leaf_no) {
1814                         error = get_leaf(dip, leaf_no, &bh);
1815                         if (error)
1816                                 goto out;
1817                         leaf = (struct gfs2_leaf *)bh->b_data;
1818                         len = 1 << (dip->i_depth - be16_to_cpu(leaf->lf_depth));
1819                         brelse(bh);
1820
1821                         error = lc(dip, index, len, leaf_no, data);
1822                         if (error)
1823                                 goto out;
1824
1825                         index = (index & ~(len - 1)) + len;
1826                 } else
1827                         index++;
1828         }
1829
1830         if (index != hsize) {
1831                 gfs2_consist_inode(dip);
1832                 error = -EIO;
1833         }
1834
1835 out:
1836         kfree(lp);
1837
1838         return error;
1839 }
1840
1841 /**
1842  * leaf_dealloc - Deallocate a directory leaf
1843  * @dip: the directory
1844  * @index: the hash table offset in the directory
1845  * @len: the number of pointers to this leaf
1846  * @leaf_no: the leaf number
1847  * @data: not used
1848  *
1849  * Returns: errno
1850  */
1851
1852 static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len,
1853                         u64 leaf_no, void *data)
1854 {
1855         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1856         struct gfs2_leaf *tmp_leaf;
1857         struct gfs2_rgrp_list rlist;
1858         struct buffer_head *bh, *dibh;
1859         u64 blk, nblk;
1860         unsigned int rg_blocks = 0, l_blocks = 0;
1861         char *ht;
1862         unsigned int x, size = len * sizeof(u64);
1863         int error;
1864
1865         memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
1866
1867         ht = kzalloc(size, GFP_NOFS);
1868         if (!ht)
1869                 return -ENOMEM;
1870
1871         if (!gfs2_alloc_get(dip)) {
1872                 error = -ENOMEM;
1873                 goto out;
1874         }
1875
1876         error = gfs2_quota_hold(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
1877         if (error)
1878                 goto out_put;
1879
1880         error = gfs2_rindex_hold(sdp, &dip->i_alloc->al_ri_gh);
1881         if (error)
1882                 goto out_qs;
1883
1884         /*  Count the number of leaves  */
1885
1886         for (blk = leaf_no; blk; blk = nblk) {
1887                 error = get_leaf(dip, blk, &bh);
1888                 if (error)
1889                         goto out_rlist;
1890                 tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1891                 nblk = be64_to_cpu(tmp_leaf->lf_next);
1892                 brelse(bh);
1893
1894                 gfs2_rlist_add(sdp, &rlist, blk);
1895                 l_blocks++;
1896         }
1897
1898         gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
1899
1900         for (x = 0; x < rlist.rl_rgrps; x++) {
1901                 struct gfs2_rgrpd *rgd;
1902                 rgd = rlist.rl_ghs[x].gh_gl->gl_object;
1903                 rg_blocks += rgd->rd_length;
1904         }
1905
1906         error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
1907         if (error)
1908                 goto out_rlist;
1909
1910         error = gfs2_trans_begin(sdp,
1911                         rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
1912                         RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
1913         if (error)
1914                 goto out_rg_gunlock;
1915
1916         for (blk = leaf_no; blk; blk = nblk) {
1917                 error = get_leaf(dip, blk, &bh);
1918                 if (error)
1919                         goto out_end_trans;
1920                 tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1921                 nblk = be64_to_cpu(tmp_leaf->lf_next);
1922                 brelse(bh);
1923
1924                 gfs2_free_meta(dip, blk, 1);
1925                 gfs2_add_inode_blocks(&dip->i_inode, -1);
1926         }
1927
1928         error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size);
1929         if (error != size) {
1930                 if (error >= 0)
1931                         error = -EIO;
1932                 goto out_end_trans;
1933         }
1934
1935         error = gfs2_meta_inode_buffer(dip, &dibh);
1936         if (error)
1937                 goto out_end_trans;
1938
1939         gfs2_trans_add_bh(dip->i_gl, dibh, 1);
1940         gfs2_dinode_out(dip, dibh->b_data);
1941         brelse(dibh);
1942
1943 out_end_trans:
1944         gfs2_trans_end(sdp);
1945 out_rg_gunlock:
1946         gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
1947 out_rlist:
1948         gfs2_rlist_free(&rlist);
1949         gfs2_glock_dq_uninit(&dip->i_alloc->al_ri_gh);
1950 out_qs:
1951         gfs2_quota_unhold(dip);
1952 out_put:
1953         gfs2_alloc_put(dip);
1954 out:
1955         kfree(ht);
1956         return error;
1957 }
1958
1959 /**
1960  * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory
1961  * @dip: the directory
1962  *
1963  * Dealloc all on-disk directory leaves to FREEMETA state
1964  * Change on-disk inode type to "regular file"
1965  *
1966  * Returns: errno
1967  */
1968
1969 int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip)
1970 {
1971         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1972         struct buffer_head *bh;
1973         int error;
1974
1975         /* Dealloc on-disk leaves to FREEMETA state */
1976         error = foreach_leaf(dip, leaf_dealloc, NULL);
1977         if (error)
1978                 return error;
1979
1980         /* Make this a regular file in case we crash.
1981            (We don't want to free these blocks a second time.)  */
1982
1983         error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1984         if (error)
1985                 return error;
1986
1987         error = gfs2_meta_inode_buffer(dip, &bh);
1988         if (!error) {
1989                 gfs2_trans_add_bh(dip->i_gl, bh, 1);
1990                 ((struct gfs2_dinode *)bh->b_data)->di_mode =
1991                                                 cpu_to_be32(S_IFREG);
1992                 brelse(bh);
1993         }
1994
1995         gfs2_trans_end(sdp);
1996
1997         return error;
1998 }
1999
2000 /**
2001  * gfs2_diradd_alloc_required - find if adding entry will require an allocation
2002  * @ip: the file being written to
2003  * @filname: the filename that's going to be added
2004  *
2005  * Returns: 1 if alloc required, 0 if not, -ve on error
2006  */
2007
2008 int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name)
2009 {
2010         struct gfs2_dirent *dent;
2011         struct buffer_head *bh;
2012
2013         dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
2014         if (!dent) {
2015                 return 1;
2016         }
2017         if (IS_ERR(dent))
2018                 return PTR_ERR(dent);
2019         brelse(bh);
2020         return 0;
2021 }
2022