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 = GFS2_DIRENT_SIZE(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
 529 /**
 530  * dirent_first - Return the first dirent
 531  * @dip: the directory
 532  * @bh: The buffer
 533  * @dent: Pointer to list of dirents
 534  *
 535  * return first dirent whether bh points to leaf or stuffed dinode
 536  *
 537  * Returns: IS_LEAF, IS_DINODE, or -errno
 538  */
 539
 540 static int dirent_first(struct gfs2_inode *dip, struct buffer_head *bh,
 541                         struct gfs2_dirent **dent)
 542 {
 543         struct gfs2_meta_header *h = (struct gfs2_meta_header *)bh->b_data;
 544
 545         if (be32_to_cpu(h->mh_type) == GFS2_METATYPE_LF) {
 546                 if (gfs2_meta_check(GFS2_SB(&dip->i_inode), bh))
 547                         return -EIO;
 548                 *dent = (struct gfs2_dirent *)(bh->b_data +
 549                                                sizeof(struct gfs2_leaf));
 550                 return IS_LEAF;
 551         } else {
 552                 if (gfs2_metatype_check(GFS2_SB(&dip->i_inode), bh, GFS2_METATYPE_DI))
 553                         return -EIO;
 554                 *dent = (struct gfs2_dirent *)(bh->b_data +
 555                                                sizeof(struct gfs2_dinode));
 556                 return IS_DINODE;
 557         }
 558 }
 559
 560 static int dirent_check_reclen(struct gfs2_inode *dip,
 561                                const struct gfs2_dirent *d, const void *end_p)
 562 {
 563         const void *ptr = d;
 564         u16 rec_len = be16_to_cpu(d->de_rec_len);
 565
 566         if (unlikely(rec_len < sizeof(struct gfs2_dirent)))
 567                 goto broken;
 568         ptr += rec_len;
 569         if (ptr < end_p)
 570                 return rec_len;
 571         if (ptr == end_p)
 572                 return -ENOENT;
 573 broken:
 574         gfs2_consist_inode(dip);
 575         return -EIO;
 576 }
 577
 578 /**
 579  * dirent_next - Next dirent
 580  * @dip: the directory
 581  * @bh: The buffer
 582  * @dent: Pointer to list of dirents
 583  *
 584  * Returns: 0 on success, error code otherwise
 585  */
 586
 587 static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh,
 588                        struct gfs2_dirent **dent)
 589 {
 590         struct gfs2_dirent *cur = *dent, *tmp;
 591         char *bh_end = bh->b_data + bh->b_size;
 592         int ret;
 593
 594         ret = dirent_check_reclen(dip, cur, bh_end);
 595         if (ret < 0)
 596                 return ret;
 597
 598         tmp = (void *)cur + ret;
 599         ret = dirent_check_reclen(dip, tmp, bh_end);
 600         if (ret == -EIO)
 601                 return ret;
 602
 603         /* Only the first dent could ever have de_inum.no_addr == 0 */
 604         if (gfs2_dirent_sentinel(tmp)) {
 605                 gfs2_consist_inode(dip);
 606                 return -EIO;
 607         }
 608
 609         *dent = tmp;
 610         return 0;
 611 }
 612
 613 /**
 614  * dirent_del - Delete a dirent
 615  * @dip: The GFS2 inode
 616  * @bh: The buffer
 617  * @prev: The previous dirent
 618  * @cur: The current dirent
 619  *
 620  */
 621
 622 static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh,
 623                        struct gfs2_dirent *prev, struct gfs2_dirent *cur)
 624 {
 625         u16 cur_rec_len, prev_rec_len;
 626
 627         if (gfs2_dirent_sentinel(cur)) {
 628                 gfs2_consist_inode(dip);
 629                 return;
 630         }
 631
 632         gfs2_trans_add_bh(dip->i_gl, bh, 1);
 633
 634         /* If there is no prev entry, this is the first entry in the block.
 635            The de_rec_len is already as big as it needs to be.  Just zero
 636            out the inode number and return.  */
 637
 638         if (!prev) {
 639                 cur->de_inum.no_addr = 0;
 640                 cur->de_inum.no_formal_ino = 0;
 641                 return;
 642         }
 643
 644         /*  Combine this dentry with the previous one.  */
 645
 646         prev_rec_len = be16_to_cpu(prev->de_rec_len);
 647         cur_rec_len = be16_to_cpu(cur->de_rec_len);
 648
 649         if ((char *)prev + prev_rec_len != (char *)cur)
 650                 gfs2_consist_inode(dip);
 651         if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size)
 652                 gfs2_consist_inode(dip);
 653
 654         prev_rec_len += cur_rec_len;
 655         prev->de_rec_len = cpu_to_be16(prev_rec_len);
 656 }
 657
 658 /*
 659  * Takes a dent from which to grab space as an argument. Returns the
 660  * newly created dent.
 661  */
 662 static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
 663                                             struct gfs2_dirent *dent,
 664                                             const struct qstr *name,
 665                                             struct buffer_head *bh)
 666 {
 667         struct gfs2_inode *ip = GFS2_I(inode);
 668         struct gfs2_dirent *ndent;
 669         unsigned offset = 0, totlen;
 670
 671         if (!gfs2_dirent_sentinel(dent))
 672                 offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 673         totlen = be16_to_cpu(dent->de_rec_len);
 674         BUG_ON(offset + name->len > totlen);
 675         gfs2_trans_add_bh(ip->i_gl, bh, 1);
 676         ndent = (struct gfs2_dirent *)((char *)dent + offset);
 677         dent->de_rec_len = cpu_to_be16(offset);
 678         gfs2_qstr2dirent(name, totlen - offset, ndent);
 679         return ndent;
 680 }
 681
 682 static struct gfs2_dirent *gfs2_dirent_alloc(struct inode *inode,
 683                                              struct buffer_head *bh,
 684                                              const struct qstr *name)
 685 {
 686         struct gfs2_dirent *dent;
 687         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 688                                 gfs2_dirent_find_space, name, NULL);
 689         if (!dent || IS_ERR(dent))
 690                 return dent;
 691         return gfs2_init_dirent(inode, dent, name, bh);
 692 }
 693
 694 static int get_leaf(struct gfs2_inode *dip, u64 leaf_no,
 695                     struct buffer_head **bhp)
 696 {
 697         int error;
 698
 699         error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, bhp);
 700         if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) {
 701                 /* printk(KERN_INFO "block num=%llu\n", leaf_no); */
 702                 error = -EIO;
 703         }
 704
 705         return error;
 706 }
 707
 708 /**
 709  * get_leaf_nr - Get a leaf number associated with the index
 710  * @dip: The GFS2 inode
 711  * @index:
 712  * @leaf_out:
 713  *
 714  * Returns: 0 on success, error code otherwise
 715  */
 716
 717 static int get_leaf_nr(struct gfs2_inode *dip, u32 index,
 718                        u64 *leaf_out)
 719 {
 720         __be64 leaf_no;
 721         int error;
 722
 723         error = gfs2_dir_read_data(dip, (char *)&leaf_no,
 724                                     index * sizeof(__be64),
 725                                     sizeof(__be64), 0);
 726         if (error != sizeof(u64))
 727                 return (error < 0) ? error : -EIO;
 728
 729         *leaf_out = be64_to_cpu(leaf_no);
 730
 731         return 0;
 732 }
 733
 734 static int get_first_leaf(struct gfs2_inode *dip, u32 index,
 735                           struct buffer_head **bh_out)
 736 {
 737         u64 leaf_no;
 738         int error;
 739
 740         error = get_leaf_nr(dip, index, &leaf_no);
 741         if (!error)
 742                 error = get_leaf(dip, leaf_no, bh_out);
 743
 744         return error;
 745 }
 746
 747 static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
 748                                               const struct qstr *name,
 749                                               gfs2_dscan_t scan,
 750                                               struct buffer_head **pbh)
 751 {
 752         struct buffer_head *bh;
 753         struct gfs2_dirent *dent;
 754         struct gfs2_inode *ip = GFS2_I(inode);
 755         int error;
 756
 757         if (ip->i_diskflags & GFS2_DIF_EXHASH) {
 758                 struct gfs2_leaf *leaf;
 759                 unsigned hsize = 1 << ip->i_depth;
 760                 unsigned index;
 761                 u64 ln;
 762                 if (hsize * sizeof(u64) != ip->i_disksize) {
 763                         gfs2_consist_inode(ip);
 764                         return ERR_PTR(-EIO);
 765                 }
 766
 767                 index = name->hash >> (32 - ip->i_depth);
 768                 error = get_first_leaf(ip, index, &bh);
 769                 if (error)
 770                         return ERR_PTR(error);
 771                 do {
 772                         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 773                                                 scan, name, NULL);
 774                         if (dent)
 775                                 goto got_dent;
 776                         leaf = (struct gfs2_leaf *)bh->b_data;
 777                         ln = be64_to_cpu(leaf->lf_next);
 778                         brelse(bh);
 779                         if (!ln)
 780                                 break;
 781
 782                         error = get_leaf(ip, ln, &bh);
 783                 } while(!error);
 784
 785                 return error ? ERR_PTR(error) : NULL;
 786         }
 787
 788
 789         error = gfs2_meta_inode_buffer(ip, &bh);
 790         if (error)
 791                 return ERR_PTR(error);
 792         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
 793 got_dent:
 794         if (unlikely(dent == NULL || IS_ERR(dent))) {
 795                 brelse(bh);
 796                 bh = NULL;
 797         }
 798         *pbh = bh;
 799         return dent;
 800 }
 801
 802 static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
 803 {
 804         struct gfs2_inode *ip = GFS2_I(inode);
 805         unsigned int n = 1;
 806         u64 bn;
 807         int error;
 808         struct buffer_head *bh;
 809         struct gfs2_leaf *leaf;
 810         struct gfs2_dirent *dent;
 811         struct qstr name = { .name = "", .len = 0, .hash = 0 };
 812
 813         error = gfs2_alloc_block(ip, &bn, &n);
 814         if (error)
 815                 return NULL;
 816         bh = gfs2_meta_new(ip->i_gl, bn);
 817         if (!bh)
 818                 return NULL;
 819
 820         gfs2_trans_add_unrevoke(GFS2_SB(inode), bn, 1);
 821         gfs2_trans_add_bh(ip->i_gl, bh, 1);
 822         gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF);
 823         leaf = (struct gfs2_leaf *)bh->b_data;
 824         leaf->lf_depth = cpu_to_be16(depth);
 825         leaf->lf_entries = 0;
 826         leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
 827         leaf->lf_next = 0;
 828         memset(leaf->lf_reserved, 0, sizeof(leaf->lf_reserved));
 829         dent = (struct gfs2_dirent *)(leaf+1);
 830         gfs2_qstr2dirent(&name, bh->b_size - sizeof(struct gfs2_leaf), dent);
 831         *pbh = bh;
 832         return leaf;
 833 }
 834
 835 /**
 836  * dir_make_exhash - Convert a stuffed directory into an ExHash directory
 837  * @dip: The GFS2 inode
 838  *
 839  * Returns: 0 on success, error code otherwise
 840  */
 841
 842 static int dir_make_exhash(struct inode *inode)
 843 {
 844         struct gfs2_inode *dip = GFS2_I(inode);
 845         struct gfs2_sbd *sdp = GFS2_SB(inode);
 846         struct gfs2_dirent *dent;
 847         struct qstr args;
 848         struct buffer_head *bh, *dibh;
 849         struct gfs2_leaf *leaf;
 850         int y;
 851         u32 x;
 852         __be64 *lp;
 853         u64 bn;
 854         int error;
 855
 856         error = gfs2_meta_inode_buffer(dip, &dibh);
 857         if (error)
 858                 return error;
 859
 860         /*  Turn over a new leaf  */
 861
 862         leaf = new_leaf(inode, &bh, 0);
 863         if (!leaf)
 864                 return -ENOSPC;
 865         bn = bh->b_blocknr;
 866
 867         gfs2_assert(sdp, dip->i_entries < (1 << 16));
 868         leaf->lf_entries = cpu_to_be16(dip->i_entries);
 869
 870         /*  Copy dirents  */
 871
 872         gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
 873                              sizeof(struct gfs2_dinode));
 874
 875         /*  Find last entry  */
 876
 877         x = 0;
 878         args.len = bh->b_size - sizeof(struct gfs2_dinode) +
 879                    sizeof(struct gfs2_leaf);
 880         args.name = bh->b_data;
 881         dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size,
 882                                 gfs2_dirent_last, &args, NULL);
 883         if (!dent) {
 884                 brelse(bh);
 885                 brelse(dibh);
 886                 return -EIO;
 887         }
 888         if (IS_ERR(dent)) {
 889                 brelse(bh);
 890                 brelse(dibh);
 891                 return PTR_ERR(dent);
 892         }
 893
 894         /*  Adjust the last dirent's record length
 895            (Remember that dent still points to the last entry.)  */
 896
 897         dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
 898                 sizeof(struct gfs2_dinode) -
 899                 sizeof(struct gfs2_leaf));
 900
 901         brelse(bh);
 902
 903         /*  We're done with the new leaf block, now setup the new
 904             hash table.  */
 905
 906         gfs2_trans_add_bh(dip->i_gl, dibh, 1);
 907         gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
 908
 909         lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
 910
 911         for (x = sdp->sd_hash_ptrs; x--; lp++)
 912                 *lp = cpu_to_be64(bn);
 913
 914         dip->i_disksize = sdp->sd_sb.sb_bsize / 2;
 915         gfs2_add_inode_blocks(&dip->i_inode, 1);
 916         dip->i_diskflags |= GFS2_DIF_EXHASH;
 917
 918         for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
 919         dip->i_depth = y;
 920
 921         gfs2_dinode_out(dip, dibh->b_data);
 922
 923         brelse(dibh);
 924
 925         return 0;
 926 }
 927
 928 /**
 929  * dir_split_leaf - Split a leaf block into two
 930  * @dip: The GFS2 inode
 931  * @index:
 932  * @leaf_no:
 933  *
 934  * Returns: 0 on success, error code on failure
 935  */
 936
 937 static int dir_split_leaf(struct inode *inode, const struct qstr *name)
 938 {
 939         struct gfs2_inode *dip = GFS2_I(inode);
 940         struct buffer_head *nbh, *obh, *dibh;
 941         struct gfs2_leaf *nleaf, *oleaf;
 942         struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new;
 943         u32 start, len, half_len, divider;
 944         u64 bn, leaf_no;
 945         __be64 *lp;
 946         u32 index;
 947         int x, moved = 0;
 948         int error;
 949
 950         index = name->hash >> (32 - dip->i_depth);
 951         error = get_leaf_nr(dip, index, &leaf_no);
 952         if (error)
 953                 return error;
 954
 955         /*  Get the old leaf block  */
 956         error = get_leaf(dip, leaf_no, &obh);
 957         if (error)
 958                 return error;
 959
 960         oleaf = (struct gfs2_leaf *)obh->b_data;
 961         if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
 962                 brelse(obh);
 963                 return 1; /* can't split */
 964         }
 965
 966         gfs2_trans_add_bh(dip->i_gl, obh, 1);
 967
 968         nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
 969         if (!nleaf) {
 970                 brelse(obh);
 971                 return -ENOSPC;
 972         }
 973         bn = nbh->b_blocknr;
 974
 975         /*  Compute the start and len of leaf pointers in the hash table.  */
 976         len = 1 << (dip->i_depth - be16_to_cpu(oleaf->lf_depth));
 977         half_len = len >> 1;
 978         if (!half_len) {
 979                 printk(KERN_WARNING "i_depth %u lf_depth %u index %u\n", dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
 980                 gfs2_consist_inode(dip);
 981                 error = -EIO;
 982                 goto fail_brelse;
 983         }
 984
 985         start = (index & ~(len - 1));
 986
 987         /* Change the pointers.
 988            Don't bother distinguishing stuffed from non-stuffed.
 989            This code is complicated enough already. */
 990         lp = kmalloc(half_len * sizeof(__be64), GFP_NOFS | __GFP_NOFAIL);
 991         /*  Change the pointers  */
 992         for (x = 0; x < half_len; x++)
 993                 lp[x] = cpu_to_be64(bn);
 994
 995         error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64),
 996                                     half_len * sizeof(u64));
 997         if (error != half_len * sizeof(u64)) {
 998                 if (error >= 0)
 999                         error = -EIO;
1000                 goto fail_lpfree;
1001         }
1002
1003         kfree(lp);
1004
1005         /*  Compute the divider  */
1006         divider = (start + half_len) << (32 - dip->i_depth);
1007
1008         /*  Copy the entries  */
1009         dirent_first(dip, obh, &dent);
1010
1011         do {
1012                 next = dent;
1013                 if (dirent_next(dip, obh, &next))
1014                         next = NULL;
1015
1016                 if (!gfs2_dirent_sentinel(dent) &&
1017                     be32_to_cpu(dent->de_hash) < divider) {
1018                         struct qstr str;
1019                         str.name = (char*)(dent+1);
1020                         str.len = be16_to_cpu(dent->de_name_len);
1021                         str.hash = be32_to_cpu(dent->de_hash);
1022                         new = gfs2_dirent_alloc(inode, nbh, &str);
1023                         if (IS_ERR(new)) {
1024                                 error = PTR_ERR(new);
1025                                 break;
1026                         }
1027
1028                         new->de_inum = dent->de_inum; /* No endian worries */
1029                         new->de_type = dent->de_type; /* No endian worries */
1030                         be16_add_cpu(&nleaf->lf_entries, 1);
1031
1032                         dirent_del(dip, obh, prev, dent);
1033
1034                         if (!oleaf->lf_entries)
1035                                 gfs2_consist_inode(dip);
1036                         be16_add_cpu(&oleaf->lf_entries, -1);
1037
1038                         if (!prev)
1039                                 prev = dent;
1040
1041                         moved = 1;
1042                 } else {
1043                         prev = dent;
1044                 }
1045                 dent = next;
1046         } while (dent);
1047
1048         oleaf->lf_depth = nleaf->lf_depth;
1049
1050         error = gfs2_meta_inode_buffer(dip, &dibh);
1051         if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) {
1052                 gfs2_trans_add_bh(dip->i_gl, dibh, 1);
1053                 gfs2_add_inode_blocks(&dip->i_inode, 1);
1054                 gfs2_dinode_out(dip, dibh->b_data);
1055                 brelse(dibh);
1056         }
1057
1058         brelse(obh);
1059         brelse(nbh);
1060
1061         return error;
1062
1063 fail_lpfree:
1064         kfree(lp);
1065
1066 fail_brelse:
1067         brelse(obh);
1068         brelse(nbh);
1069         return error;
1070 }
1071
1072 /**
1073  * dir_double_exhash - Double size of ExHash table
1074  * @dip: The GFS2 dinode
1075  *
1076  * Returns: 0 on success, error code on failure
1077  */
1078
1079 static int dir_double_exhash(struct gfs2_inode *dip)
1080 {
1081         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1082         struct buffer_head *dibh;
1083         u32 hsize;
1084         u64 *buf;
1085         u64 *from, *to;
1086         u64 block;
1087         int x;
1088         int error = 0;
1089
1090         hsize = 1 << dip->i_depth;
1091         if (hsize * sizeof(u64) != dip->i_disksize) {
1092                 gfs2_consist_inode(dip);
1093                 return -EIO;
1094         }
1095
1096         /*  Allocate both the "from" and "to" buffers in one big chunk  */
1097
1098         buf = kcalloc(3, sdp->sd_hash_bsize, GFP_NOFS | __GFP_NOFAIL);
1099
1100         for (block = dip->i_disksize >> sdp->sd_hash_bsize_shift; block--;) {
1101                 error = gfs2_dir_read_data(dip, (char *)buf,
1102                                             block * sdp->sd_hash_bsize,
1103                                             sdp->sd_hash_bsize, 1);
1104                 if (error != sdp->sd_hash_bsize) {
1105                         if (error >= 0)
1106                                 error = -EIO;
1107                         goto fail;
1108                 }
1109
1110                 from = buf;
1111                 to = (u64 *)((char *)buf + sdp->sd_hash_bsize);
1112
1113                 for (x = sdp->sd_hash_ptrs; x--; from++) {
1114                         *to++ = *from;  /*  No endianess worries  */
1115                         *to++ = *from;
1116                 }
1117
1118                 error = gfs2_dir_write_data(dip,
1119                                              (char *)buf + sdp->sd_hash_bsize,
1120                                              block * sdp->sd_sb.sb_bsize,
1121                                              sdp->sd_sb.sb_bsize);
1122                 if (error != sdp->sd_sb.sb_bsize) {
1123                         if (error >= 0)
1124                                 error = -EIO;
1125                         goto fail;
1126                 }
1127         }
1128
1129         kfree(buf);
1130
1131         error = gfs2_meta_inode_buffer(dip, &dibh);
1132         if (!gfs2_assert_withdraw(sdp, !error)) {
1133                 dip->i_depth++;
1134                 gfs2_dinode_out(dip, dibh->b_data);
1135                 brelse(dibh);
1136         }
1137
1138         return error;
1139
1140 fail:
1141         kfree(buf);
1142         return error;
1143 }
1144
1145 /**
1146  * compare_dents - compare directory entries by hash value
1147  * @a: first dent
1148  * @b: second dent
1149  *
1150  * When comparing the hash entries of @a to @b:
1151  *   gt: returns 1
1152  *   lt: returns -1
1153  *   eq: returns 0
1154  */
1155
1156 static int compare_dents(const void *a, const void *b)
1157 {
1158         const struct gfs2_dirent *dent_a, *dent_b;
1159         u32 hash_a, hash_b;
1160         int ret = 0;
1161
1162         dent_a = *(const struct gfs2_dirent **)a;
1163         hash_a = be32_to_cpu(dent_a->de_hash);
1164
1165         dent_b = *(const struct gfs2_dirent **)b;
1166         hash_b = be32_to_cpu(dent_b->de_hash);
1167
1168         if (hash_a > hash_b)
1169                 ret = 1;
1170         else if (hash_a < hash_b)
1171                 ret = -1;
1172         else {
1173                 unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
1174                 unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
1175
1176                 if (len_a > len_b)
1177                         ret = 1;
1178                 else if (len_a < len_b)
1179                         ret = -1;
1180                 else
1181                         ret = memcmp(dent_a + 1, dent_b + 1, len_a);
1182         }
1183
1184         return ret;
1185 }
1186
1187 /**
1188  * do_filldir_main - read out directory entries
1189  * @dip: The GFS2 inode
1190  * @offset: The offset in the file to read from
1191  * @opaque: opaque data to pass to filldir
1192  * @filldir: The function to pass entries to
1193  * @darr: an array of struct gfs2_dirent pointers to read
1194  * @entries: the number of entries in darr
1195  * @copied: pointer to int that's non-zero if a entry has been copied out
1196  *
1197  * Jump through some hoops to make sure that if there are hash collsions,
1198  * they are read out at the beginning of a buffer.  We want to minimize
1199  * the possibility that they will fall into different readdir buffers or
1200  * that someone will want to seek to that location.
1201  *
1202  * Returns: errno, >0 on exception from filldir
1203  */
1204
1205 static int do_filldir_main(struct gfs2_inode *dip, u64 *offset,
1206                            void *opaque, filldir_t filldir,
1207                            const struct gfs2_dirent **darr, u32 entries,
1208                            int *copied)
1209 {
1210         const struct gfs2_dirent *dent, *dent_next;
1211         u64 off, off_next;
1212         unsigned int x, y;
1213         int run = 0;
1214         int error = 0;
1215
1216         sort(darr, entries, sizeof(struct gfs2_dirent *), compare_dents, NULL);
1217
1218         dent_next = darr[0];
1219         off_next = be32_to_cpu(dent_next->de_hash);
1220         off_next = gfs2_disk_hash2offset(off_next);
1221
1222         for (x = 0, y = 1; x < entries; x++, y++) {
1223                 dent = dent_next;
1224                 off = off_next;
1225
1226                 if (y < entries) {
1227                         dent_next = darr[y];
1228                         off_next = be32_to_cpu(dent_next->de_hash);
1229                         off_next = gfs2_disk_hash2offset(off_next);
1230
1231                         if (off < *offset)
1232                                 continue;
1233                         *offset = off;
1234
1235                         if (off_next == off) {
1236                                 if (*copied && !run)
1237                                         return 1;
1238                                 run = 1;
1239                         } else
1240                                 run = 0;
1241                 } else {
1242                         if (off < *offset)
1243                                 continue;
1244                         *offset = off;
1245                 }
1246
1247                 error = filldir(opaque, (const char *)(dent + 1),
1248                                 be16_to_cpu(dent->de_name_len),
1249                                 off, be64_to_cpu(dent->de_inum.no_addr),
1250                                 be16_to_cpu(dent->de_type));
1251                 if (error)
1252                         return 1;
1253
1254                 *copied = 1;
1255         }
1256
1257         /* Increment the *offset by one, so the next time we come into the
1258            do_filldir fxn, we get the next entry instead of the last one in the
1259            current leaf */
1260
1261         (*offset)++;
1262
1263         return 0;
1264 }
1265
1266 static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
1267                               filldir_t filldir, int *copied, unsigned *depth,
1268                               u64 leaf_no)
1269 {
1270         struct gfs2_inode *ip = GFS2_I(inode);
1271         struct gfs2_sbd *sdp = GFS2_SB(inode);
1272         struct buffer_head *bh;
1273         struct gfs2_leaf *lf;
1274         unsigned entries = 0, entries2 = 0;
1275         unsigned leaves = 0;
1276         const struct gfs2_dirent **darr, *dent;
1277         struct dirent_gather g;
1278         struct buffer_head **larr;
1279         int leaf = 0;
1280         int error, i;
1281         u64 lfn = leaf_no;
1282
1283         do {
1284                 error = get_leaf(ip, lfn, &bh);
1285                 if (error)
1286                         goto out;
1287                 lf = (struct gfs2_leaf *)bh->b_data;
1288                 if (leaves == 0)
1289                         *depth = be16_to_cpu(lf->lf_depth);
1290                 entries += be16_to_cpu(lf->lf_entries);
1291                 leaves++;
1292                 lfn = be64_to_cpu(lf->lf_next);
1293                 brelse(bh);
1294         } while(lfn);
1295
1296         if (!entries)
1297                 return 0;
1298
1299         error = -ENOMEM;
1300         /*
1301          * The extra 99 entries are not normally used, but are a buffer
1302          * zone in case the number of entries in the leaf is corrupt.
1303          * 99 is the maximum number of entries that can fit in a single
1304          * leaf block.
1305          */
1306         larr = vmalloc((leaves + entries + 99) * sizeof(void *));
1307         if (!larr)
1308                 goto out;
1309         darr = (const struct gfs2_dirent **)(larr + leaves);
1310         g.pdent = darr;
1311         g.offset = 0;
1312         lfn = leaf_no;
1313
1314         do {
1315                 error = get_leaf(ip, lfn, &bh);
1316                 if (error)
1317                         goto out_kfree;
1318                 lf = (struct gfs2_leaf *)bh->b_data;
1319                 lfn = be64_to_cpu(lf->lf_next);
1320                 if (lf->lf_entries) {
1321                         entries2 += be16_to_cpu(lf->lf_entries);
1322                         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
1323                                                 gfs2_dirent_gather, NULL, &g);
1324                         error = PTR_ERR(dent);
1325                         if (IS_ERR(dent))
1326                                 goto out_kfree;
1327                         if (entries2 != g.offset) {
1328                                 fs_warn(sdp, "Number of entries corrupt in dir "
1329                                                 "leaf %llu, entries2 (%u) != "
1330                                                 "g.offset (%u)\n",
1331                                         (unsigned long long)bh->b_blocknr,
1332                                         entries2, g.offset);
1333
1334                                 error = -EIO;
1335                                 goto out_kfree;
1336                         }
1337                         error = 0;
1338                         larr[leaf++] = bh;
1339                 } else {
1340                         brelse(bh);
1341                 }
1342         } while(lfn);
1343
1344         BUG_ON(entries2 != entries);
1345         error = do_filldir_main(ip, offset, opaque, filldir, darr,
1346                                 entries, copied);
1347 out_kfree:
1348         for(i = 0; i < leaf; i++)
1349                 brelse(larr[i]);
1350         vfree(larr);
1351 out:
1352         return error;
1353 }
1354
1355 /**
1356  * dir_e_read - Reads the entries from a directory into a filldir buffer
1357  * @dip: dinode pointer
1358  * @offset: the hash of the last entry read shifted to the right once
1359  * @opaque: buffer for the filldir function to fill
1360  * @filldir: points to the filldir function to use
1361  *
1362  * Returns: errno
1363  */
1364
1365 static int dir_e_read(struct inode *inode, u64 *offset, void *opaque,
1366                       filldir_t filldir)
1367 {
1368         struct gfs2_inode *dip = GFS2_I(inode);
1369         struct gfs2_sbd *sdp = GFS2_SB(inode);
1370         u32 hsize, len = 0;
1371         u32 ht_offset, lp_offset, ht_offset_cur = -1;
1372         u32 hash, index;
1373         __be64 *lp;
1374         int copied = 0;
1375         int error = 0;
1376         unsigned depth = 0;
1377
1378         hsize = 1 << dip->i_depth;
1379         if (hsize * sizeof(u64) != dip->i_disksize) {
1380                 gfs2_consist_inode(dip);
1381                 return -EIO;
1382         }
1383
1384         hash = gfs2_dir_offset2hash(*offset);
1385         index = hash >> (32 - dip->i_depth);
1386
1387         lp = kmalloc(sdp->sd_hash_bsize, GFP_NOFS);
1388         if (!lp)
1389                 return -ENOMEM;
1390
1391         while (index < hsize) {
1392                 lp_offset = index & (sdp->sd_hash_ptrs - 1);
1393                 ht_offset = index - lp_offset;
1394
1395                 if (ht_offset_cur != ht_offset) {
1396                         error = gfs2_dir_read_data(dip, (char *)lp,
1397                                                 ht_offset * sizeof(__be64),
1398                                                 sdp->sd_hash_bsize, 1);
1399                         if (error != sdp->sd_hash_bsize) {
1400                                 if (error >= 0)
1401                                         error = -EIO;
1402                                 goto out;
1403                         }
1404                         ht_offset_cur = ht_offset;
1405                 }
1406
1407                 error = gfs2_dir_read_leaf(inode, offset, opaque, filldir,
1408                                            &copied, &depth,
1409                                            be64_to_cpu(lp[lp_offset]));
1410                 if (error)
1411                         break;
1412
1413                 len = 1 << (dip->i_depth - depth);
1414                 index = (index & ~(len - 1)) + len;
1415         }
1416
1417 out:
1418         kfree(lp);
1419         if (error > 0)
1420                 error = 0;
1421         return error;
1422 }
1423
1424 int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque,
1425                   filldir_t filldir)
1426 {
1427         struct gfs2_inode *dip = GFS2_I(inode);
1428         struct gfs2_sbd *sdp = GFS2_SB(inode);
1429         struct dirent_gather g;
1430         const struct gfs2_dirent **darr, *dent;
1431         struct buffer_head *dibh;
1432         int copied = 0;
1433         int error;
1434
1435         if (!dip->i_entries)
1436                 return 0;
1437
1438         if (dip->i_diskflags & GFS2_DIF_EXHASH)
1439                 return dir_e_read(inode, offset, opaque, filldir);
1440
1441         if (!gfs2_is_stuffed(dip)) {
1442                 gfs2_consist_inode(dip);
1443                 return -EIO;
1444         }
1445
1446         error = gfs2_meta_inode_buffer(dip, &dibh);
1447         if (error)
1448                 return error;
1449
1450         error = -ENOMEM;
1451         /* 96 is max number of dirents which can be stuffed into an inode */
1452         darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_NOFS);
1453         if (darr) {
1454                 g.pdent = darr;
1455                 g.offset = 0;
1456                 dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size,
1457                                         gfs2_dirent_gather, NULL, &g);
1458                 if (IS_ERR(dent)) {
1459                         error = PTR_ERR(dent);
1460                         goto out;
1461                 }
1462                 if (dip->i_entries != g.offset) {
1463                         fs_warn(sdp, "Number of entries corrupt in dir %llu, "
1464                                 "ip->i_entries (%u) != g.offset (%u)\n",
1465                                 (unsigned long long)dip->i_no_addr,
1466                                 dip->i_entries,
1467                                 g.offset);
1468                         error = -EIO;
1469                         goto out;
1470                 }
1471                 error = do_filldir_main(dip, offset, opaque, filldir, darr,
1472                                         dip->i_entries, &copied);
1473 out:
1474                 kfree(darr);
1475         }
1476
1477         if (error > 0)
1478                 error = 0;
1479
1480         brelse(dibh);
1481
1482         return error;
1483 }
1484
1485 /**
1486  * gfs2_dir_search - Search a directory
1487  * @dip: The GFS2 inode
1488  * @filename:
1489  * @inode:
1490  *
1491  * This routine searches a directory for a file or another directory.
1492  * Assumes a glock is held on dip.
1493  *
1494  * Returns: errno
1495  */
1496
1497 struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name)
1498 {
1499         struct buffer_head *bh;
1500         struct gfs2_dirent *dent;
1501         struct inode *inode;
1502
1503         dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1504         if (dent) {
1505                 if (IS_ERR(dent))
1506                         return ERR_CAST(dent);
1507                 inode = gfs2_inode_lookup(dir->i_sb,
1508                                 be16_to_cpu(dent->de_type),
1509                                 be64_to_cpu(dent->de_inum.no_addr),
1510                                 be64_to_cpu(dent->de_inum.no_formal_ino), 0);
1511                 brelse(bh);
1512                 return inode;
1513         }
1514         return ERR_PTR(-ENOENT);
1515 }
1516
1517 int gfs2_dir_check(struct inode *dir, const struct qstr *name,
1518                    const struct gfs2_inode *ip)
1519 {
1520         struct buffer_head *bh;
1521         struct gfs2_dirent *dent;
1522         int ret = -ENOENT;
1523
1524         dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1525         if (dent) {
1526                 if (IS_ERR(dent))
1527                         return PTR_ERR(dent);
1528                 if (ip) {
1529                         if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
1530                                 goto out;
1531                         if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
1532                             ip->i_no_formal_ino)
1533                                 goto out;
1534                         if (unlikely(IF2DT(ip->i_inode.i_mode) !=
1535                             be16_to_cpu(dent->de_type))) {
1536                                 gfs2_consist_inode(GFS2_I(dir));
1537                                 ret = -EIO;
1538                                 goto out;
1539                         }
1540                 }
1541                 ret = 0;
1542 out:
1543                 brelse(bh);
1544         }
1545         return ret;
1546 }
1547
1548 static int dir_new_leaf(struct inode *inode, const struct qstr *name)
1549 {
1550         struct buffer_head *bh, *obh;
1551         struct gfs2_inode *ip = GFS2_I(inode);
1552         struct gfs2_leaf *leaf, *oleaf;
1553         int error;
1554         u32 index;
1555         u64 bn;
1556
1557         index = name->hash >> (32 - ip->i_depth);
1558         error = get_first_leaf(ip, index, &obh);
1559         if (error)
1560                 return error;
1561         do {
1562                 oleaf = (struct gfs2_leaf *)obh->b_data;
1563                 bn = be64_to_cpu(oleaf->lf_next);
1564                 if (!bn)
1565                         break;
1566                 brelse(obh);
1567                 error = get_leaf(ip, bn, &obh);
1568                 if (error)
1569                         return error;
1570         } while(1);
1571
1572         gfs2_trans_add_bh(ip->i_gl, obh, 1);
1573
1574         leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
1575         if (!leaf) {
1576                 brelse(obh);
1577                 return -ENOSPC;
1578         }
1579         oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
1580         brelse(bh);
1581         brelse(obh);
1582
1583         error = gfs2_meta_inode_buffer(ip, &bh);
1584         if (error)
1585                 return error;
1586         gfs2_trans_add_bh(ip->i_gl, bh, 1);
1587         gfs2_add_inode_blocks(&ip->i_inode, 1);
1588         gfs2_dinode_out(ip, bh->b_data);
1589         brelse(bh);
1590         return 0;
1591 }
1592
1593 /**
1594  * gfs2_dir_add - Add new filename into directory
1595  * @dip: The GFS2 inode
1596  * @filename: The new name
1597  * @inode: The inode number of the entry
1598  * @type: The type of the entry
1599  *
1600  * Returns: 0 on success, error code on failure
1601  */
1602
1603 int gfs2_dir_add(struct inode *inode, const struct qstr *name,
1604                  const struct gfs2_inode *nip, unsigned type)
1605 {
1606         struct gfs2_inode *ip = GFS2_I(inode);
1607         struct buffer_head *bh;
1608         struct gfs2_dirent *dent;
1609         struct gfs2_leaf *leaf;
1610         int error;
1611
1612         while(1) {
1613                 dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space,
1614                                           &bh);
1615                 if (dent) {
1616                         if (IS_ERR(dent))
1617                                 return PTR_ERR(dent);
1618                         dent = gfs2_init_dirent(inode, dent, name, bh);
1619                         gfs2_inum_out(nip, dent);
1620                         dent->de_type = cpu_to_be16(type);
1621                         if (ip->i_diskflags & GFS2_DIF_EXHASH) {
1622                                 leaf = (struct gfs2_leaf *)bh->b_data;
1623                                 be16_add_cpu(&leaf->lf_entries, 1);
1624                         }
1625                         brelse(bh);
1626                         error = gfs2_meta_inode_buffer(ip, &bh);
1627                         if (error)
1628                                 break;
1629                         gfs2_trans_add_bh(ip->i_gl, bh, 1);
1630                         ip->i_entries++;
1631                         ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
1632                         gfs2_dinode_out(ip, bh->b_data);
1633                         brelse(bh);
1634                         error = 0;
1635                         break;
1636                 }
1637                 if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) {
1638                         error = dir_make_exhash(inode);
1639                         if (error)
1640                                 break;
1641                         continue;
1642                 }
1643                 error = dir_split_leaf(inode, name);
1644                 if (error == 0)
1645                         continue;
1646                 if (error < 0)
1647                         break;
1648                 if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
1649                         error = dir_double_exhash(ip);
1650                         if (error)
1651                                 break;
1652                         error = dir_split_leaf(inode, name);
1653                         if (error < 0)
1654                                 break;
1655                         if (error == 0)
1656                                 continue;
1657                 }
1658                 error = dir_new_leaf(inode, name);
1659                 if (!error)
1660                         continue;
1661                 error = -ENOSPC;
1662                 break;
1663         }
1664         return error;
1665 }
1666
1667
1668 /**
1669  * gfs2_dir_del - Delete a directory entry
1670  * @dip: The GFS2 inode
1671  * @filename: The filename
1672  *
1673  * Returns: 0 on success, error code on failure
1674  */
1675
1676 int gfs2_dir_del(struct gfs2_inode *dip, const struct qstr *name)
1677 {
1678         struct gfs2_dirent *dent, *prev = NULL;
1679         struct buffer_head *bh;
1680         int error;
1681
1682         /* Returns _either_ the entry (if its first in block) or the
1683            previous entry otherwise */
1684         dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh);
1685         if (!dent) {
1686                 gfs2_consist_inode(dip);
1687                 return -EIO;
1688         }
1689         if (IS_ERR(dent)) {
1690                 gfs2_consist_inode(dip);
1691                 return PTR_ERR(dent);
1692         }
1693         /* If not first in block, adjust pointers accordingly */
1694         if (gfs2_dirent_find(dent, name, NULL) == 0) {
1695                 prev = dent;
1696                 dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
1697         }
1698
1699         dirent_del(dip, bh, prev, dent);
1700         if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1701                 struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
1702                 u16 entries = be16_to_cpu(leaf->lf_entries);
1703                 if (!entries)
1704                         gfs2_consist_inode(dip);
1705                 leaf->lf_entries = cpu_to_be16(--entries);
1706         }
1707         brelse(bh);
1708
1709         error = gfs2_meta_inode_buffer(dip, &bh);
1710         if (error)
1711                 return error;
1712
1713         if (!dip->i_entries)
1714                 gfs2_consist_inode(dip);
1715         gfs2_trans_add_bh(dip->i_gl, bh, 1);
1716         dip->i_entries--;
1717         dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1718         gfs2_dinode_out(dip, bh->b_data);
1719         brelse(bh);
1720         mark_inode_dirty(&dip->i_inode);
1721
1722         return error;
1723 }
1724
1725 /**
1726  * gfs2_dir_mvino - Change inode number of directory entry
1727  * @dip: The GFS2 inode
1728  * @filename:
1729  * @new_inode:
1730  *
1731  * This routine changes the inode number of a directory entry.  It's used
1732  * by rename to change ".." when a directory is moved.
1733  * Assumes a glock is held on dvp.
1734  *
1735  * Returns: errno
1736  */
1737
1738 int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
1739                    const struct gfs2_inode *nip, unsigned int new_type)
1740 {
1741         struct buffer_head *bh;
1742         struct gfs2_dirent *dent;
1743         int error;
1744
1745         dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh);
1746         if (!dent) {
1747                 gfs2_consist_inode(dip);
1748                 return -EIO;
1749         }
1750         if (IS_ERR(dent))
1751                 return PTR_ERR(dent);
1752
1753         gfs2_trans_add_bh(dip->i_gl, bh, 1);
1754         gfs2_inum_out(nip, dent);
1755         dent->de_type = cpu_to_be16(new_type);
1756
1757         if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1758                 brelse(bh);
1759                 error = gfs2_meta_inode_buffer(dip, &bh);
1760                 if (error)
1761                         return error;
1762                 gfs2_trans_add_bh(dip->i_gl, bh, 1);
1763         }
1764
1765         dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1766         gfs2_dinode_out(dip, bh->b_data);
1767         brelse(bh);
1768         return 0;
1769 }
1770
1771 /**
1772  * foreach_leaf - call a function for each leaf in a directory
1773  * @dip: the directory
1774  * @lc: the function to call for each each
1775  * @data: private data to pass to it
1776  *
1777  * Returns: errno
1778  */
1779
1780 static int foreach_leaf(struct gfs2_inode *dip, leaf_call_t lc, void *data)
1781 {
1782         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1783         struct buffer_head *bh;
1784         struct gfs2_leaf *leaf;
1785         u32 hsize, len;
1786         u32 ht_offset, lp_offset, ht_offset_cur = -1;
1787         u32 index = 0;
1788         __be64 *lp;
1789         u64 leaf_no;
1790         int error = 0;
1791
1792         hsize = 1 << dip->i_depth;
1793         if (hsize * sizeof(u64) != dip->i_disksize) {
1794                 gfs2_consist_inode(dip);
1795                 return -EIO;
1796         }
1797
1798         lp = kmalloc(sdp->sd_hash_bsize, GFP_NOFS);
1799         if (!lp)
1800                 return -ENOMEM;
1801
1802         while (index < hsize) {
1803                 lp_offset = index & (sdp->sd_hash_ptrs - 1);
1804                 ht_offset = index - lp_offset;
1805
1806                 if (ht_offset_cur != ht_offset) {
1807                         error = gfs2_dir_read_data(dip, (char *)lp,
1808                                                 ht_offset * sizeof(__be64),
1809                                                 sdp->sd_hash_bsize, 1);
1810                         if (error != sdp->sd_hash_bsize) {
1811                                 if (error >= 0)
1812                                         error = -EIO;
1813                                 goto out;
1814                         }
1815                         ht_offset_cur = ht_offset;
1816                 }
1817
1818                 leaf_no = be64_to_cpu(lp[lp_offset]);
1819                 if (leaf_no) {
1820                         error = get_leaf(dip, leaf_no, &bh);
1821                         if (error)
1822                                 goto out;
1823                         leaf = (struct gfs2_leaf *)bh->b_data;
1824                         len = 1 << (dip->i_depth - be16_to_cpu(leaf->lf_depth));
1825                         brelse(bh);
1826
1827                         error = lc(dip, index, len, leaf_no, data);
1828                         if (error)
1829                                 goto out;
1830
1831                         index = (index & ~(len - 1)) + len;
1832                 } else
1833                         index++;
1834         }
1835
1836         if (index != hsize) {
1837                 gfs2_consist_inode(dip);
1838                 error = -EIO;
1839         }
1840
1841 out:
1842         kfree(lp);
1843
1844         return error;
1845 }
1846
1847 /**
1848  * leaf_dealloc - Deallocate a directory leaf
1849  * @dip: the directory
1850  * @index: the hash table offset in the directory
1851  * @len: the number of pointers to this leaf
1852  * @leaf_no: the leaf number
1853  * @data: not used
1854  *
1855  * Returns: errno
1856  */
1857
1858 static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len,
1859                         u64 leaf_no, void *data)
1860 {
1861         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1862         struct gfs2_leaf *tmp_leaf;
1863         struct gfs2_rgrp_list rlist;
1864         struct buffer_head *bh, *dibh;
1865         u64 blk, nblk;
1866         unsigned int rg_blocks = 0, l_blocks = 0;
1867         char *ht;
1868         unsigned int x, size = len * sizeof(u64);
1869         int error;
1870
1871         memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
1872
1873         ht = kzalloc(size, GFP_NOFS);
1874         if (!ht)
1875                 return -ENOMEM;
1876
1877         if (!gfs2_alloc_get(dip)) {
1878                 error = -ENOMEM;
1879                 goto out;
1880         }
1881
1882         error = gfs2_quota_hold(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
1883         if (error)
1884                 goto out_put;
1885
1886         error = gfs2_rindex_hold(sdp, &dip->i_alloc->al_ri_gh);
1887         if (error)
1888                 goto out_qs;
1889
1890         /*  Count the number of leaves  */
1891
1892         for (blk = leaf_no; blk; blk = nblk) {
1893                 error = get_leaf(dip, blk, &bh);
1894                 if (error)
1895                         goto out_rlist;
1896                 tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1897                 nblk = be64_to_cpu(tmp_leaf->lf_next);
1898                 brelse(bh);
1899
1900                 gfs2_rlist_add(sdp, &rlist, blk);
1901                 l_blocks++;
1902         }
1903
1904         gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
1905
1906         for (x = 0; x < rlist.rl_rgrps; x++) {
1907                 struct gfs2_rgrpd *rgd;
1908                 rgd = rlist.rl_ghs[x].gh_gl->gl_object;
1909                 rg_blocks += rgd->rd_length;
1910         }
1911
1912         error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
1913         if (error)
1914                 goto out_rlist;
1915
1916         error = gfs2_trans_begin(sdp,
1917                         rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
1918                         RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
1919         if (error)
1920                 goto out_rg_gunlock;
1921
1922         for (blk = leaf_no; blk; blk = nblk) {
1923                 error = get_leaf(dip, blk, &bh);
1924                 if (error)
1925                         goto out_end_trans;
1926                 tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1927                 nblk = be64_to_cpu(tmp_leaf->lf_next);
1928                 brelse(bh);
1929
1930                 gfs2_free_meta(dip, blk, 1);
1931                 gfs2_add_inode_blocks(&dip->i_inode, -1);
1932         }
1933
1934         error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size);
1935         if (error != size) {
1936                 if (error >= 0)
1937                         error = -EIO;
1938                 goto out_end_trans;
1939         }
1940
1941         error = gfs2_meta_inode_buffer(dip, &dibh);
1942         if (error)
1943                 goto out_end_trans;
1944
1945         gfs2_trans_add_bh(dip->i_gl, dibh, 1);
1946         gfs2_dinode_out(dip, dibh->b_data);
1947         brelse(dibh);
1948
1949 out_end_trans:
1950         gfs2_trans_end(sdp);
1951 out_rg_gunlock:
1952         gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
1953 out_rlist:
1954         gfs2_rlist_free(&rlist);
1955         gfs2_glock_dq_uninit(&dip->i_alloc->al_ri_gh);
1956 out_qs:
1957         gfs2_quota_unhold(dip);
1958 out_put:
1959         gfs2_alloc_put(dip);
1960 out:
1961         kfree(ht);
1962         return error;
1963 }
1964
1965 /**
1966  * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory
1967  * @dip: the directory
1968  *
1969  * Dealloc all on-disk directory leaves to FREEMETA state
1970  * Change on-disk inode type to "regular file"
1971  *
1972  * Returns: errno
1973  */
1974
1975 int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip)
1976 {
1977         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1978         struct buffer_head *bh;
1979         int error;
1980
1981         /* Dealloc on-disk leaves to FREEMETA state */
1982         error = foreach_leaf(dip, leaf_dealloc, NULL);
1983         if (error)
1984                 return error;
1985
1986         /* Make this a regular file in case we crash.
1987            (We don't want to free these blocks a second time.)  */
1988
1989         error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1990         if (error)
1991                 return error;
1992
1993         error = gfs2_meta_inode_buffer(dip, &bh);
1994         if (!error) {
1995                 gfs2_trans_add_bh(dip->i_gl, bh, 1);
1996                 ((struct gfs2_dinode *)bh->b_data)->di_mode =
1997                                                 cpu_to_be32(S_IFREG);
1998                 brelse(bh);
1999         }
2000
2001         gfs2_trans_end(sdp);
2002
2003         return error;
2004 }
2005
2006 /**
2007  * gfs2_diradd_alloc_required - find if adding entry will require an allocation
2008  * @ip: the file being written to
2009  * @filname: the filename that's going to be added
2010  *
2011  * Returns: 1 if alloc required, 0 if not, -ve on error
2012  */
2013
2014 int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name)
2015 {
2016         struct gfs2_dirent *dent;
2017         struct buffer_head *bh;
2018
2019         dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
2020         if (!dent) {
2021                 return 1;
2022         }
2023         if (IS_ERR(dent))
2024                 return PTR_ERR(dent);
2025         brelse(bh);
2026         return 0;
2027 }
2028