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 struct qstr gfs2_qdot __read_mostly;
  83 struct qstr gfs2_qdotdot __read_mostly;
  84
  85 typedef int (*leaf_call_t) (struct gfs2_inode *dip, u32 index, u32 len,
  86                             u64 leaf_no, void *data);
  87 typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent,
  88                             const struct qstr *name, void *opaque);
  89
  90
  91 int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
  92                             struct buffer_head **bhp)
  93 {
  94         struct buffer_head *bh;
  95
  96         bh = gfs2_meta_new(ip->i_gl, block);
  97         gfs2_trans_add_bh(ip->i_gl, bh, 1);
  98         gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
  99         gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
 100         *bhp = bh;
 101         return 0;
 102 }
 103
 104 static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, u64 block,
 105                                         struct buffer_head **bhp)
 106 {
 107         struct buffer_head *bh;
 108         int error;
 109
 110         error = gfs2_meta_read(ip->i_gl, block, DIO_WAIT, &bh);
 111         if (error)
 112                 return error;
 113         if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_JD)) {
 114                 brelse(bh);
 115                 return -EIO;
 116         }
 117         *bhp = bh;
 118         return 0;
 119 }
 120
 121 static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
 122                                   unsigned int offset, unsigned int size)
 123 {
 124         struct buffer_head *dibh;
 125         int error;
 126
 127         error = gfs2_meta_inode_buffer(ip, &dibh);
 128         if (error)
 129                 return error;
 130
 131         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 132         memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
 133         if (ip->i_inode.i_size < offset + size)
 134                 i_size_write(&ip->i_inode, offset + size);
 135         ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 136         gfs2_dinode_out(ip, dibh->b_data);
 137
 138         brelse(dibh);
 139
 140         return size;
 141 }
 142
 143
 144
 145 /**
 146  * gfs2_dir_write_data - Write directory information to the inode
 147  * @ip: The GFS2 inode
 148  * @buf: The buffer containing information to be written
 149  * @offset: The file offset to start writing at
 150  * @size: The amount of data to write
 151  *
 152  * Returns: The number of bytes correctly written or error code
 153  */
 154 static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
 155                                u64 offset, unsigned int size)
 156 {
 157         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 158         struct buffer_head *dibh;
 159         u64 lblock, dblock;
 160         u32 extlen = 0;
 161         unsigned int o;
 162         int copied = 0;
 163         int error = 0;
 164         int new = 0;
 165
 166         if (!size)
 167                 return 0;
 168
 169         if (gfs2_is_stuffed(ip) &&
 170             offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
 171                 return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
 172                                               size);
 173
 174         if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
 175                 return -EINVAL;
 176
 177         if (gfs2_is_stuffed(ip)) {
 178                 error = gfs2_unstuff_dinode(ip, NULL);
 179                 if (error)
 180                         return error;
 181         }
 182
 183         lblock = offset;
 184         o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
 185
 186         while (copied < size) {
 187                 unsigned int amount;
 188                 struct buffer_head *bh;
 189
 190                 amount = size - copied;
 191                 if (amount > sdp->sd_sb.sb_bsize - o)
 192                         amount = sdp->sd_sb.sb_bsize - o;
 193
 194                 if (!extlen) {
 195                         new = 1;
 196                         error = gfs2_extent_map(&ip->i_inode, lblock, &new,
 197                                                 &dblock, &extlen);
 198                         if (error)
 199                                 goto fail;
 200                         error = -EIO;
 201                         if (gfs2_assert_withdraw(sdp, dblock))
 202                                 goto fail;
 203                 }
 204
 205                 if (amount == sdp->sd_jbsize || new)
 206                         error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
 207                 else
 208                         error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
 209
 210                 if (error)
 211                         goto fail;
 212
 213                 gfs2_trans_add_bh(ip->i_gl, bh, 1);
 214                 memcpy(bh->b_data + o, buf, amount);
 215                 brelse(bh);
 216
 217                 buf += amount;
 218                 copied += amount;
 219                 lblock++;
 220                 dblock++;
 221                 extlen--;
 222
 223                 o = sizeof(struct gfs2_meta_header);
 224         }
 225
 226 out:
 227         error = gfs2_meta_inode_buffer(ip, &dibh);
 228         if (error)
 229                 return error;
 230
 231         if (ip->i_inode.i_size < offset + copied)
 232                 i_size_write(&ip->i_inode, offset + copied);
 233         ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 234
 235         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 236         gfs2_dinode_out(ip, dibh->b_data);
 237         brelse(dibh);
 238
 239         return copied;
 240 fail:
 241         if (copied)
 242                 goto out;
 243         return error;
 244 }
 245
 246 static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, char *buf,
 247                                  u64 offset, unsigned int size)
 248 {
 249         struct buffer_head *dibh;
 250         int error;
 251
 252         error = gfs2_meta_inode_buffer(ip, &dibh);
 253         if (!error) {
 254                 offset += sizeof(struct gfs2_dinode);
 255                 memcpy(buf, dibh->b_data + offset, size);
 256                 brelse(dibh);
 257         }
 258
 259         return (error) ? error : size;
 260 }
 261
 262
 263 /**
 264  * gfs2_dir_read_data - Read a data from a directory inode
 265  * @ip: The GFS2 Inode
 266  * @buf: The buffer to place result into
 267  * @offset: File offset to begin jdata_readng from
 268  * @size: Amount of data to transfer
 269  *
 270  * Returns: The amount of data actually copied or the error
 271  */
 272 static int gfs2_dir_read_data(struct gfs2_inode *ip, char *buf, u64 offset,
 273                               unsigned int size, unsigned ra)
 274 {
 275         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 276         u64 lblock, dblock;
 277         u32 extlen = 0;
 278         unsigned int o;
 279         int copied = 0;
 280         int error = 0;
 281         u64 disksize = i_size_read(&ip->i_inode);
 282
 283         if (offset >= disksize)
 284                 return 0;
 285
 286         if (offset + size > disksize)
 287                 size = disksize - offset;
 288
 289         if (!size)
 290                 return 0;
 291
 292         if (gfs2_is_stuffed(ip))
 293                 return gfs2_dir_read_stuffed(ip, buf, offset, size);
 294
 295         if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
 296                 return -EINVAL;
 297
 298         lblock = offset;
 299         o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
 300
 301         while (copied < size) {
 302                 unsigned int amount;
 303                 struct buffer_head *bh;
 304                 int new;
 305
 306                 amount = size - copied;
 307                 if (amount > sdp->sd_sb.sb_bsize - o)
 308                         amount = sdp->sd_sb.sb_bsize - o;
 309
 310                 if (!extlen) {
 311                         new = 0;
 312                         error = gfs2_extent_map(&ip->i_inode, lblock, &new,
 313                                                 &dblock, &extlen);
 314                         if (error || !dblock)
 315                                 goto fail;
 316                         BUG_ON(extlen < 1);
 317                         if (!ra)
 318                                 extlen = 1;
 319                         bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
 320                 } else {
 321                         error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, &bh);
 322                         if (error)
 323                                 goto fail;
 324                 }
 325                 error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD);
 326                 if (error) {
 327                         brelse(bh);
 328                         goto fail;
 329                 }
 330                 dblock++;
 331                 extlen--;
 332                 memcpy(buf, bh->b_data + o, amount);
 333                 brelse(bh);
 334                 buf += amount;
 335                 copied += amount;
 336                 lblock++;
 337                 o = sizeof(struct gfs2_meta_header);
 338         }
 339
 340         return copied;
 341 fail:
 342         return (copied) ? copied : error;
 343 }
 344
 345 static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent)
 346 {
 347         return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0;
 348 }
 349
 350 static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
 351                                      const struct qstr *name, int ret)
 352 {
 353         if (!gfs2_dirent_sentinel(dent) &&
 354             be32_to_cpu(dent->de_hash) == name->hash &&
 355             be16_to_cpu(dent->de_name_len) == name->len &&
 356             memcmp(dent+1, name->name, name->len) == 0)
 357                 return ret;
 358         return 0;
 359 }
 360
 361 static int gfs2_dirent_find(const struct gfs2_dirent *dent,
 362                             const struct qstr *name,
 363                             void *opaque)
 364 {
 365         return __gfs2_dirent_find(dent, name, 1);
 366 }
 367
 368 static int gfs2_dirent_prev(const struct gfs2_dirent *dent,
 369                             const struct qstr *name,
 370                             void *opaque)
 371 {
 372         return __gfs2_dirent_find(dent, name, 2);
 373 }
 374
 375 /*
 376  * name->name holds ptr to start of block.
 377  * name->len holds size of block.
 378  */
 379 static int gfs2_dirent_last(const struct gfs2_dirent *dent,
 380                             const struct qstr *name,
 381                             void *opaque)
 382 {
 383         const char *start = name->name;
 384         const char *end = (const char *)dent + be16_to_cpu(dent->de_rec_len);
 385         if (name->len == (end - start))
 386                 return 1;
 387         return 0;
 388 }
 389
 390 static int gfs2_dirent_find_space(const struct gfs2_dirent *dent,
 391                                   const struct qstr *name,
 392                                   void *opaque)
 393 {
 394         unsigned required = GFS2_DIRENT_SIZE(name->len);
 395         unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 396         unsigned totlen = be16_to_cpu(dent->de_rec_len);
 397
 398         if (gfs2_dirent_sentinel(dent))
 399                 actual = 0;
 400         if (totlen - actual >= required)
 401                 return 1;
 402         return 0;
 403 }
 404
 405 struct dirent_gather {
 406         const struct gfs2_dirent **pdent;
 407         unsigned offset;
 408 };
 409
 410 static int gfs2_dirent_gather(const struct gfs2_dirent *dent,
 411                               const struct qstr *name,
 412                               void *opaque)
 413 {
 414         struct dirent_gather *g = opaque;
 415         if (!gfs2_dirent_sentinel(dent)) {
 416                 g->pdent[g->offset++] = dent;
 417         }
 418         return 0;
 419 }
 420
 421 /*
 422  * Other possible things to check:
 423  * - Inode located within filesystem size (and on valid block)
 424  * - Valid directory entry type
 425  * Not sure how heavy-weight we want to make this... could also check
 426  * hash is correct for example, but that would take a lot of extra time.
 427  * For now the most important thing is to check that the various sizes
 428  * are correct.
 429  */
 430 static int gfs2_check_dirent(struct gfs2_dirent *dent, unsigned int offset,
 431                              unsigned int size, unsigned int len, int first)
 432 {
 433         const char *msg = "gfs2_dirent too small";
 434         if (unlikely(size < sizeof(struct gfs2_dirent)))
 435                 goto error;
 436         msg = "gfs2_dirent misaligned";
 437         if (unlikely(offset & 0x7))
 438                 goto error;
 439         msg = "gfs2_dirent points beyond end of block";
 440         if (unlikely(offset + size > len))
 441                 goto error;
 442         msg = "zero inode number";
 443         if (unlikely(!first && gfs2_dirent_sentinel(dent)))
 444                 goto error;
 445         msg = "name length is greater than space in dirent";
 446         if (!gfs2_dirent_sentinel(dent) &&
 447             unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
 448                      size))
 449                 goto error;
 450         return 0;
 451 error:
 452         printk(KERN_WARNING "gfs2_check_dirent: %s (%s)\n", msg,
 453                first ? "first in block" : "not first in block");
 454         return -EIO;
 455 }
 456
 457 static int gfs2_dirent_offset(const void *buf)
 458 {
 459         const struct gfs2_meta_header *h = buf;
 460         int offset;
 461
 462         BUG_ON(buf == NULL);
 463
 464         switch(be32_to_cpu(h->mh_type)) {
 465         case GFS2_METATYPE_LF:
 466                 offset = sizeof(struct gfs2_leaf);
 467                 break;
 468         case GFS2_METATYPE_DI:
 469                 offset = sizeof(struct gfs2_dinode);
 470                 break;
 471         default:
 472                 goto wrong_type;
 473         }
 474         return offset;
 475 wrong_type:
 476         printk(KERN_WARNING "gfs2_scan_dirent: wrong block type %u\n",
 477                be32_to_cpu(h->mh_type));
 478         return -1;
 479 }
 480
 481 static struct gfs2_dirent *gfs2_dirent_scan(struct inode *inode, void *buf,
 482                                             unsigned int len, gfs2_dscan_t scan,
 483                                             const struct qstr *name,
 484                                             void *opaque)
 485 {
 486         struct gfs2_dirent *dent, *prev;
 487         unsigned offset;
 488         unsigned size;
 489         int ret = 0;
 490
 491         ret = gfs2_dirent_offset(buf);
 492         if (ret < 0)
 493                 goto consist_inode;
 494
 495         offset = ret;
 496         prev = NULL;
 497         dent = buf + offset;
 498         size = be16_to_cpu(dent->de_rec_len);
 499         if (gfs2_check_dirent(dent, offset, size, len, 1))
 500                 goto consist_inode;
 501         do {
 502                 ret = scan(dent, name, opaque);
 503                 if (ret)
 504                         break;
 505                 offset += size;
 506                 if (offset == len)
 507                         break;
 508                 prev = dent;
 509                 dent = buf + offset;
 510                 size = be16_to_cpu(dent->de_rec_len);
 511                 if (gfs2_check_dirent(dent, offset, size, len, 0))
 512                         goto consist_inode;
 513         } while(1);
 514
 515         switch(ret) {
 516         case 0:
 517                 return NULL;
 518         case 1:
 519                 return dent;
 520         case 2:
 521                 return prev ? prev : dent;
 522         default:
 523                 BUG_ON(ret > 0);
 524                 return ERR_PTR(ret);
 525         }
 526
 527 consist_inode:
 528         gfs2_consist_inode(GFS2_I(inode));
 529         return ERR_PTR(-EIO);
 530 }
 531
 532 static int dirent_check_reclen(struct gfs2_inode *dip,
 533                                const struct gfs2_dirent *d, const void *end_p)
 534 {
 535         const void *ptr = d;
 536         u16 rec_len = be16_to_cpu(d->de_rec_len);
 537
 538         if (unlikely(rec_len < sizeof(struct gfs2_dirent)))
 539                 goto broken;
 540         ptr += rec_len;
 541         if (ptr < end_p)
 542                 return rec_len;
 543         if (ptr == end_p)
 544                 return -ENOENT;
 545 broken:
 546         gfs2_consist_inode(dip);
 547         return -EIO;
 548 }
 549
 550 /**
 551  * dirent_next - Next dirent
 552  * @dip: the directory
 553  * @bh: The buffer
 554  * @dent: Pointer to list of dirents
 555  *
 556  * Returns: 0 on success, error code otherwise
 557  */
 558
 559 static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh,
 560                        struct gfs2_dirent **dent)
 561 {
 562         struct gfs2_dirent *cur = *dent, *tmp;
 563         char *bh_end = bh->b_data + bh->b_size;
 564         int ret;
 565
 566         ret = dirent_check_reclen(dip, cur, bh_end);
 567         if (ret < 0)
 568                 return ret;
 569
 570         tmp = (void *)cur + ret;
 571         ret = dirent_check_reclen(dip, tmp, bh_end);
 572         if (ret == -EIO)
 573                 return ret;
 574
 575         /* Only the first dent could ever have de_inum.no_addr == 0 */
 576         if (gfs2_dirent_sentinel(tmp)) {
 577                 gfs2_consist_inode(dip);
 578                 return -EIO;
 579         }
 580
 581         *dent = tmp;
 582         return 0;
 583 }
 584
 585 /**
 586  * dirent_del - Delete a dirent
 587  * @dip: The GFS2 inode
 588  * @bh: The buffer
 589  * @prev: The previous dirent
 590  * @cur: The current dirent
 591  *
 592  */
 593
 594 static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh,
 595                        struct gfs2_dirent *prev, struct gfs2_dirent *cur)
 596 {
 597         u16 cur_rec_len, prev_rec_len;
 598
 599         if (gfs2_dirent_sentinel(cur)) {
 600                 gfs2_consist_inode(dip);
 601                 return;
 602         }
 603
 604         gfs2_trans_add_bh(dip->i_gl, bh, 1);
 605
 606         /* If there is no prev entry, this is the first entry in the block.
 607            The de_rec_len is already as big as it needs to be.  Just zero
 608            out the inode number and return.  */
 609
 610         if (!prev) {
 611                 cur->de_inum.no_addr = 0;
 612                 cur->de_inum.no_formal_ino = 0;
 613                 return;
 614         }
 615
 616         /*  Combine this dentry with the previous one.  */
 617
 618         prev_rec_len = be16_to_cpu(prev->de_rec_len);
 619         cur_rec_len = be16_to_cpu(cur->de_rec_len);
 620
 621         if ((char *)prev + prev_rec_len != (char *)cur)
 622                 gfs2_consist_inode(dip);
 623         if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size)
 624                 gfs2_consist_inode(dip);
 625
 626         prev_rec_len += cur_rec_len;
 627         prev->de_rec_len = cpu_to_be16(prev_rec_len);
 628 }
 629
 630 /*
 631  * Takes a dent from which to grab space as an argument. Returns the
 632  * newly created dent.
 633  */
 634 static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
 635                                             struct gfs2_dirent *dent,
 636                                             const struct qstr *name,
 637                                             struct buffer_head *bh)
 638 {
 639         struct gfs2_inode *ip = GFS2_I(inode);
 640         struct gfs2_dirent *ndent;
 641         unsigned offset = 0, totlen;
 642
 643         if (!gfs2_dirent_sentinel(dent))
 644                 offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 645         totlen = be16_to_cpu(dent->de_rec_len);
 646         BUG_ON(offset + name->len > totlen);
 647         gfs2_trans_add_bh(ip->i_gl, bh, 1);
 648         ndent = (struct gfs2_dirent *)((char *)dent + offset);
 649         dent->de_rec_len = cpu_to_be16(offset);
 650         gfs2_qstr2dirent(name, totlen - offset, ndent);
 651         return ndent;
 652 }
 653
 654 static struct gfs2_dirent *gfs2_dirent_alloc(struct inode *inode,
 655                                              struct buffer_head *bh,
 656                                              const struct qstr *name)
 657 {
 658         struct gfs2_dirent *dent;
 659         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 660                                 gfs2_dirent_find_space, name, NULL);
 661         if (!dent || IS_ERR(dent))
 662                 return dent;
 663         return gfs2_init_dirent(inode, dent, name, bh);
 664 }
 665
 666 static int get_leaf(struct gfs2_inode *dip, u64 leaf_no,
 667                     struct buffer_head **bhp)
 668 {
 669         int error;
 670
 671         error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, bhp);
 672         if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) {
 673                 /* printk(KERN_INFO "block num=%llu\n", leaf_no); */
 674                 error = -EIO;
 675         }
 676
 677         return error;
 678 }
 679
 680 /**
 681  * get_leaf_nr - Get a leaf number associated with the index
 682  * @dip: The GFS2 inode
 683  * @index:
 684  * @leaf_out:
 685  *
 686  * Returns: 0 on success, error code otherwise
 687  */
 688
 689 static int get_leaf_nr(struct gfs2_inode *dip, u32 index,
 690                        u64 *leaf_out)
 691 {
 692         __be64 leaf_no;
 693         int error;
 694
 695         error = gfs2_dir_read_data(dip, (char *)&leaf_no,
 696                                     index * sizeof(__be64),
 697                                     sizeof(__be64), 0);
 698         if (error != sizeof(u64))
 699                 return (error < 0) ? error : -EIO;
 700
 701         *leaf_out = be64_to_cpu(leaf_no);
 702
 703         return 0;
 704 }
 705
 706 static int get_first_leaf(struct gfs2_inode *dip, u32 index,
 707                           struct buffer_head **bh_out)
 708 {
 709         u64 leaf_no;
 710         int error;
 711
 712         error = get_leaf_nr(dip, index, &leaf_no);
 713         if (!error)
 714                 error = get_leaf(dip, leaf_no, bh_out);
 715
 716         return error;
 717 }
 718
 719 static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
 720                                               const struct qstr *name,
 721                                               gfs2_dscan_t scan,
 722                                               struct buffer_head **pbh)
 723 {
 724         struct buffer_head *bh;
 725         struct gfs2_dirent *dent;
 726         struct gfs2_inode *ip = GFS2_I(inode);
 727         int error;
 728
 729         if (ip->i_diskflags & GFS2_DIF_EXHASH) {
 730                 struct gfs2_leaf *leaf;
 731                 unsigned hsize = 1 << ip->i_depth;
 732                 unsigned index;
 733                 u64 ln;
 734                 if (hsize * sizeof(u64) != i_size_read(inode)) {
 735                         gfs2_consist_inode(ip);
 736                         return ERR_PTR(-EIO);
 737                 }
 738
 739                 index = name->hash >> (32 - ip->i_depth);
 740                 error = get_first_leaf(ip, index, &bh);
 741                 if (error)
 742                         return ERR_PTR(error);
 743                 do {
 744                         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 745                                                 scan, name, NULL);
 746                         if (dent)
 747                                 goto got_dent;
 748                         leaf = (struct gfs2_leaf *)bh->b_data;
 749                         ln = be64_to_cpu(leaf->lf_next);
 750                         brelse(bh);
 751                         if (!ln)
 752                                 break;
 753
 754                         error = get_leaf(ip, ln, &bh);
 755                 } while(!error);
 756
 757                 return error ? ERR_PTR(error) : NULL;
 758         }
 759
 760
 761         error = gfs2_meta_inode_buffer(ip, &bh);
 762         if (error)
 763                 return ERR_PTR(error);
 764         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
 765 got_dent:
 766         if (unlikely(dent == NULL || IS_ERR(dent))) {
 767                 brelse(bh);
 768                 bh = NULL;
 769         }
 770         *pbh = bh;
 771         return dent;
 772 }
 773
 774 static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
 775 {
 776         struct gfs2_inode *ip = GFS2_I(inode);
 777         unsigned int n = 1;
 778         u64 bn;
 779         int error;
 780         struct buffer_head *bh;
 781         struct gfs2_leaf *leaf;
 782         struct gfs2_dirent *dent;
 783         struct qstr name = { .name = "", .len = 0, .hash = 0 };
 784
 785         error = gfs2_alloc_block(ip, &bn, &n);
 786         if (error)
 787                 return NULL;
 788         bh = gfs2_meta_new(ip->i_gl, bn);
 789         if (!bh)
 790                 return NULL;
 791
 792         gfs2_trans_add_unrevoke(GFS2_SB(inode), bn, 1);
 793         gfs2_trans_add_bh(ip->i_gl, bh, 1);
 794         gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF);
 795         leaf = (struct gfs2_leaf *)bh->b_data;
 796         leaf->lf_depth = cpu_to_be16(depth);
 797         leaf->lf_entries = 0;
 798         leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
 799         leaf->lf_next = 0;
 800         memset(leaf->lf_reserved, 0, sizeof(leaf->lf_reserved));
 801         dent = (struct gfs2_dirent *)(leaf+1);
 802         gfs2_qstr2dirent(&name, bh->b_size - sizeof(struct gfs2_leaf), dent);
 803         *pbh = bh;
 804         return leaf;
 805 }
 806
 807 /**
 808  * dir_make_exhash - Convert a stuffed directory into an ExHash directory
 809  * @dip: The GFS2 inode
 810  *
 811  * Returns: 0 on success, error code otherwise
 812  */
 813
 814 static int dir_make_exhash(struct inode *inode)
 815 {
 816         struct gfs2_inode *dip = GFS2_I(inode);
 817         struct gfs2_sbd *sdp = GFS2_SB(inode);
 818         struct gfs2_dirent *dent;
 819         struct qstr args;
 820         struct buffer_head *bh, *dibh;
 821         struct gfs2_leaf *leaf;
 822         int y;
 823         u32 x;
 824         __be64 *lp;
 825         u64 bn;
 826         int error;
 827
 828         error = gfs2_meta_inode_buffer(dip, &dibh);
 829         if (error)
 830                 return error;
 831
 832         /*  Turn over a new leaf  */
 833
 834         leaf = new_leaf(inode, &bh, 0);
 835         if (!leaf)
 836                 return -ENOSPC;
 837         bn = bh->b_blocknr;
 838
 839         gfs2_assert(sdp, dip->i_entries < (1 << 16));
 840         leaf->lf_entries = cpu_to_be16(dip->i_entries);
 841
 842         /*  Copy dirents  */
 843
 844         gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
 845                              sizeof(struct gfs2_dinode));
 846
 847         /*  Find last entry  */
 848
 849         x = 0;
 850         args.len = bh->b_size - sizeof(struct gfs2_dinode) +
 851                    sizeof(struct gfs2_leaf);
 852         args.name = bh->b_data;
 853         dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size,
 854                                 gfs2_dirent_last, &args, NULL);
 855         if (!dent) {
 856                 brelse(bh);
 857                 brelse(dibh);
 858                 return -EIO;
 859         }
 860         if (IS_ERR(dent)) {
 861                 brelse(bh);
 862                 brelse(dibh);
 863                 return PTR_ERR(dent);
 864         }
 865
 866         /*  Adjust the last dirent's record length
 867            (Remember that dent still points to the last entry.)  */
 868
 869         dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
 870                 sizeof(struct gfs2_dinode) -
 871                 sizeof(struct gfs2_leaf));
 872
 873         brelse(bh);
 874
 875         /*  We're done with the new leaf block, now setup the new
 876             hash table.  */
 877
 878         gfs2_trans_add_bh(dip->i_gl, dibh, 1);
 879         gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
 880
 881         lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
 882
 883         for (x = sdp->sd_hash_ptrs; x--; lp++)
 884                 *lp = cpu_to_be64(bn);
 885
 886         i_size_write(inode, sdp->sd_sb.sb_bsize / 2);
 887         gfs2_add_inode_blocks(&dip->i_inode, 1);
 888         dip->i_diskflags |= GFS2_DIF_EXHASH;
 889
 890         for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
 891         dip->i_depth = y;
 892
 893         gfs2_dinode_out(dip, dibh->b_data);
 894
 895         brelse(dibh);
 896
 897         return 0;
 898 }
 899
 900 /**
 901  * dir_split_leaf - Split a leaf block into two
 902  * @dip: The GFS2 inode
 903  * @index:
 904  * @leaf_no:
 905  *
 906  * Returns: 0 on success, error code on failure
 907  */
 908
 909 static int dir_split_leaf(struct inode *inode, const struct qstr *name)
 910 {
 911         struct gfs2_inode *dip = GFS2_I(inode);
 912         struct buffer_head *nbh, *obh, *dibh;
 913         struct gfs2_leaf *nleaf, *oleaf;
 914         struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new;
 915         u32 start, len, half_len, divider;
 916         u64 bn, leaf_no;
 917         __be64 *lp;
 918         u32 index;
 919         int x, moved = 0;
 920         int error;
 921
 922         index = name->hash >> (32 - dip->i_depth);
 923         error = get_leaf_nr(dip, index, &leaf_no);
 924         if (error)
 925                 return error;
 926
 927         /*  Get the old leaf block  */
 928         error = get_leaf(dip, leaf_no, &obh);
 929         if (error)
 930                 return error;
 931
 932         oleaf = (struct gfs2_leaf *)obh->b_data;
 933         if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
 934                 brelse(obh);
 935                 return 1; /* can't split */
 936         }
 937
 938         gfs2_trans_add_bh(dip->i_gl, obh, 1);
 939
 940         nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
 941         if (!nleaf) {
 942                 brelse(obh);
 943                 return -ENOSPC;
 944         }
 945         bn = nbh->b_blocknr;
 946
 947         /*  Compute the start and len of leaf pointers in the hash table.  */
 948         len = 1 << (dip->i_depth - be16_to_cpu(oleaf->lf_depth));
 949         half_len = len >> 1;
 950         if (!half_len) {
 951                 printk(KERN_WARNING "i_depth %u lf_depth %u index %u\n", dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
 952                 gfs2_consist_inode(dip);
 953                 error = -EIO;
 954                 goto fail_brelse;
 955         }
 956
 957         start = (index & ~(len - 1));
 958
 959         /* Change the pointers.
 960            Don't bother distinguishing stuffed from non-stuffed.
 961            This code is complicated enough already. */
 962         lp = kmalloc(half_len * sizeof(__be64), GFP_NOFS);
 963         if (!lp) {
 964                 error = -ENOMEM;
 965                 goto fail_brelse;
 966         }
 967
 968         /*  Change the pointers  */
 969         for (x = 0; x < half_len; x++)
 970                 lp[x] = cpu_to_be64(bn);
 971
 972         error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64),
 973                                     half_len * sizeof(u64));
 974         if (error != half_len * sizeof(u64)) {
 975                 if (error >= 0)
 976                         error = -EIO;
 977                 goto fail_lpfree;
 978         }
 979
 980         kfree(lp);
 981
 982         /*  Compute the divider  */
 983         divider = (start + half_len) << (32 - dip->i_depth);
 984
 985         /*  Copy the entries  */
 986         dent = (struct gfs2_dirent *)(obh->b_data + sizeof(struct gfs2_leaf));
 987
 988         do {
 989                 next = dent;
 990                 if (dirent_next(dip, obh, &next))
 991                         next = NULL;
 992
 993                 if (!gfs2_dirent_sentinel(dent) &&
 994                     be32_to_cpu(dent->de_hash) < divider) {
 995                         struct qstr str;
 996                         str.name = (char*)(dent+1);
 997                         str.len = be16_to_cpu(dent->de_name_len);
 998                         str.hash = be32_to_cpu(dent->de_hash);
 999                         new = gfs2_dirent_alloc(inode, nbh, &str);
1000                         if (IS_ERR(new)) {
1001                                 error = PTR_ERR(new);
1002                                 break;
1003                         }
1004
1005                         new->de_inum = dent->de_inum; /* No endian worries */
1006                         new->de_type = dent->de_type; /* No endian worries */
1007                         be16_add_cpu(&nleaf->lf_entries, 1);
1008
1009                         dirent_del(dip, obh, prev, dent);
1010
1011                         if (!oleaf->lf_entries)
1012                                 gfs2_consist_inode(dip);
1013                         be16_add_cpu(&oleaf->lf_entries, -1);
1014
1015                         if (!prev)
1016                                 prev = dent;
1017
1018                         moved = 1;
1019                 } else {
1020                         prev = dent;
1021                 }
1022                 dent = next;
1023         } while (dent);
1024
1025         oleaf->lf_depth = nleaf->lf_depth;
1026
1027         error = gfs2_meta_inode_buffer(dip, &dibh);
1028         if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) {
1029                 gfs2_trans_add_bh(dip->i_gl, dibh, 1);
1030                 gfs2_add_inode_blocks(&dip->i_inode, 1);
1031                 gfs2_dinode_out(dip, dibh->b_data);
1032                 brelse(dibh);
1033         }
1034
1035         brelse(obh);
1036         brelse(nbh);
1037
1038         return error;
1039
1040 fail_lpfree:
1041         kfree(lp);
1042
1043 fail_brelse:
1044         brelse(obh);
1045         brelse(nbh);
1046         return error;
1047 }
1048
1049 /**
1050  * dir_double_exhash - Double size of ExHash table
1051  * @dip: The GFS2 dinode
1052  *
1053  * Returns: 0 on success, error code on failure
1054  */
1055
1056 static int dir_double_exhash(struct gfs2_inode *dip)
1057 {
1058         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1059         struct buffer_head *dibh;
1060         u32 hsize;
1061         u64 *buf;
1062         u64 *from, *to;
1063         u64 block;
1064         u64 disksize = i_size_read(&dip->i_inode);
1065         int x;
1066         int error = 0;
1067
1068         hsize = 1 << dip->i_depth;
1069         if (hsize * sizeof(u64) != disksize) {
1070                 gfs2_consist_inode(dip);
1071                 return -EIO;
1072         }
1073
1074         /*  Allocate both the "from" and "to" buffers in one big chunk  */
1075
1076         buf = kcalloc(3, sdp->sd_hash_bsize, GFP_NOFS);
1077         if (!buf)
1078                 return -ENOMEM;
1079
1080         for (block = disksize >> sdp->sd_hash_bsize_shift; block--;) {
1081                 error = gfs2_dir_read_data(dip, (char *)buf,
1082                                             block * sdp->sd_hash_bsize,
1083                                             sdp->sd_hash_bsize, 1);
1084                 if (error != sdp->sd_hash_bsize) {
1085                         if (error >= 0)
1086                                 error = -EIO;
1087                         goto fail;
1088                 }
1089
1090                 from = buf;
1091                 to = (u64 *)((char *)buf + sdp->sd_hash_bsize);
1092
1093                 for (x = sdp->sd_hash_ptrs; x--; from++) {
1094                         *to++ = *from;  /*  No endianess worries  */
1095                         *to++ = *from;
1096                 }
1097
1098                 error = gfs2_dir_write_data(dip,
1099                                              (char *)buf + sdp->sd_hash_bsize,
1100                                              block * sdp->sd_sb.sb_bsize,
1101                                              sdp->sd_sb.sb_bsize);
1102                 if (error != sdp->sd_sb.sb_bsize) {
1103                         if (error >= 0)
1104                                 error = -EIO;
1105                         goto fail;
1106                 }
1107         }
1108
1109         kfree(buf);
1110
1111         error = gfs2_meta_inode_buffer(dip, &dibh);
1112         if (!gfs2_assert_withdraw(sdp, !error)) {
1113                 dip->i_depth++;
1114                 gfs2_dinode_out(dip, dibh->b_data);
1115                 brelse(dibh);
1116         }
1117
1118         return error;
1119
1120 fail:
1121         kfree(buf);
1122         return error;
1123 }
1124
1125 /**
1126  * compare_dents - compare directory entries by hash value
1127  * @a: first dent
1128  * @b: second dent
1129  *
1130  * When comparing the hash entries of @a to @b:
1131  *   gt: returns 1
1132  *   lt: returns -1
1133  *   eq: returns 0
1134  */
1135
1136 static int compare_dents(const void *a, const void *b)
1137 {
1138         const struct gfs2_dirent *dent_a, *dent_b;
1139         u32 hash_a, hash_b;
1140         int ret = 0;
1141
1142         dent_a = *(const struct gfs2_dirent **)a;
1143         hash_a = be32_to_cpu(dent_a->de_hash);
1144
1145         dent_b = *(const struct gfs2_dirent **)b;
1146         hash_b = be32_to_cpu(dent_b->de_hash);
1147
1148         if (hash_a > hash_b)
1149                 ret = 1;
1150         else if (hash_a < hash_b)
1151                 ret = -1;
1152         else {
1153                 unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
1154                 unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
1155
1156                 if (len_a > len_b)
1157                         ret = 1;
1158                 else if (len_a < len_b)
1159                         ret = -1;
1160                 else
1161                         ret = memcmp(dent_a + 1, dent_b + 1, len_a);
1162         }
1163
1164         return ret;
1165 }
1166
1167 /**
1168  * do_filldir_main - read out directory entries
1169  * @dip: The GFS2 inode
1170  * @offset: The offset in the file to read from
1171  * @opaque: opaque data to pass to filldir
1172  * @filldir: The function to pass entries to
1173  * @darr: an array of struct gfs2_dirent pointers to read
1174  * @entries: the number of entries in darr
1175  * @copied: pointer to int that's non-zero if a entry has been copied out
1176  *
1177  * Jump through some hoops to make sure that if there are hash collsions,
1178  * they are read out at the beginning of a buffer.  We want to minimize
1179  * the possibility that they will fall into different readdir buffers or
1180  * that someone will want to seek to that location.
1181  *
1182  * Returns: errno, >0 on exception from filldir
1183  */
1184
1185 static int do_filldir_main(struct gfs2_inode *dip, u64 *offset,
1186                            void *opaque, filldir_t filldir,
1187                            const struct gfs2_dirent **darr, u32 entries,
1188                            int *copied)
1189 {
1190         const struct gfs2_dirent *dent, *dent_next;
1191         u64 off, off_next;
1192         unsigned int x, y;
1193         int run = 0;
1194         int error = 0;
1195
1196         sort(darr, entries, sizeof(struct gfs2_dirent *), compare_dents, NULL);
1197
1198         dent_next = darr[0];
1199         off_next = be32_to_cpu(dent_next->de_hash);
1200         off_next = gfs2_disk_hash2offset(off_next);
1201
1202         for (x = 0, y = 1; x < entries; x++, y++) {
1203                 dent = dent_next;
1204                 off = off_next;
1205
1206                 if (y < entries) {
1207                         dent_next = darr[y];
1208                         off_next = be32_to_cpu(dent_next->de_hash);
1209                         off_next = gfs2_disk_hash2offset(off_next);
1210
1211                         if (off < *offset)
1212                                 continue;
1213                         *offset = off;
1214
1215                         if (off_next == off) {
1216                                 if (*copied && !run)
1217                                         return 1;
1218                                 run = 1;
1219                         } else
1220                                 run = 0;
1221                 } else {
1222                         if (off < *offset)
1223                                 continue;
1224                         *offset = off;
1225                 }
1226
1227                 error = filldir(opaque, (const char *)(dent + 1),
1228                                 be16_to_cpu(dent->de_name_len),
1229                                 off, be64_to_cpu(dent->de_inum.no_addr),
1230                                 be16_to_cpu(dent->de_type));
1231                 if (error)
1232                         return 1;
1233
1234                 *copied = 1;
1235         }
1236
1237         /* Increment the *offset by one, so the next time we come into the
1238            do_filldir fxn, we get the next entry instead of the last one in the
1239            current leaf */
1240
1241         (*offset)++;
1242
1243         return 0;
1244 }
1245
1246 static void *gfs2_alloc_sort_buffer(unsigned size)
1247 {
1248         void *ptr = NULL;
1249
1250         if (size < KMALLOC_MAX_SIZE)
1251                 ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN);
1252         if (!ptr)
1253                 ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL);
1254         return ptr;
1255 }
1256
1257 static void gfs2_free_sort_buffer(void *ptr)
1258 {
1259         if (is_vmalloc_addr(ptr))
1260                 vfree(ptr);
1261         else
1262                 kfree(ptr);
1263 }
1264
1265 static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
1266                               filldir_t filldir, int *copied, unsigned *depth,
1267                               u64 leaf_no)
1268 {
1269         struct gfs2_inode *ip = GFS2_I(inode);
1270         struct gfs2_sbd *sdp = GFS2_SB(inode);
1271         struct buffer_head *bh;
1272         struct gfs2_leaf *lf;
1273         unsigned entries = 0, entries2 = 0;
1274         unsigned leaves = 0;
1275         const struct gfs2_dirent **darr, *dent;
1276         struct dirent_gather g;
1277         struct buffer_head **larr;
1278         int leaf = 0;
1279         int error, i;
1280         u64 lfn = leaf_no;
1281
1282         do {
1283                 error = get_leaf(ip, lfn, &bh);
1284                 if (error)
1285                         goto out;
1286                 lf = (struct gfs2_leaf *)bh->b_data;
1287                 if (leaves == 0)
1288                         *depth = be16_to_cpu(lf->lf_depth);
1289                 entries += be16_to_cpu(lf->lf_entries);
1290                 leaves++;
1291                 lfn = be64_to_cpu(lf->lf_next);
1292                 brelse(bh);
1293         } while(lfn);
1294
1295         if (!entries)
1296                 return 0;
1297
1298         error = -ENOMEM;
1299         /*
1300          * The extra 99 entries are not normally used, but are a buffer
1301          * zone in case the number of entries in the leaf is corrupt.
1302          * 99 is the maximum number of entries that can fit in a single
1303          * leaf block.
1304          */
1305         larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *));
1306         if (!larr)
1307                 goto out;
1308         darr = (const struct gfs2_dirent **)(larr + leaves);
1309         g.pdent = darr;
1310         g.offset = 0;
1311         lfn = leaf_no;
1312
1313         do {
1314                 error = get_leaf(ip, lfn, &bh);
1315                 if (error)
1316                         goto out_free;
1317                 lf = (struct gfs2_leaf *)bh->b_data;
1318                 lfn = be64_to_cpu(lf->lf_next);
1319                 if (lf->lf_entries) {
1320                         entries2 += be16_to_cpu(lf->lf_entries);
1321                         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
1322                                                 gfs2_dirent_gather, NULL, &g);
1323                         error = PTR_ERR(dent);
1324                         if (IS_ERR(dent))
1325                                 goto out_free;
1326                         if (entries2 != g.offset) {
1327                                 fs_warn(sdp, "Number of entries corrupt in dir "
1328                                                 "leaf %llu, entries2 (%u) != "
1329                                                 "g.offset (%u)\n",
1330                                         (unsigned long long)bh->b_blocknr,
1331                                         entries2, g.offset);
1332
1333                                 error = -EIO;
1334                                 goto out_free;
1335                         }
1336                         error = 0;
1337                         larr[leaf++] = bh;
1338                 } else {
1339                         brelse(bh);
1340                 }
1341         } while(lfn);
1342
1343         BUG_ON(entries2 != entries);
1344         error = do_filldir_main(ip, offset, opaque, filldir, darr,
1345                                 entries, copied);
1346 out_free:
1347         for(i = 0; i < leaf; i++)
1348                 brelse(larr[i]);
1349         gfs2_free_sort_buffer(larr);
1350 out:
1351         return error;
1352 }
1353
1354 /**
1355  * dir_e_read - Reads the entries from a directory into a filldir buffer
1356  * @dip: dinode pointer
1357  * @offset: the hash of the last entry read shifted to the right once
1358  * @opaque: buffer for the filldir function to fill
1359  * @filldir: points to the filldir function to use
1360  *
1361  * Returns: errno
1362  */
1363
1364 static int dir_e_read(struct inode *inode, u64 *offset, void *opaque,
1365                       filldir_t filldir)
1366 {
1367         struct gfs2_inode *dip = GFS2_I(inode);
1368         struct gfs2_sbd *sdp = GFS2_SB(inode);
1369         u32 hsize, len = 0;
1370         u32 ht_offset, lp_offset, ht_offset_cur = -1;
1371         u32 hash, index;
1372         __be64 *lp;
1373         int copied = 0;
1374         int error = 0;
1375         unsigned depth = 0;
1376
1377         hsize = 1 << dip->i_depth;
1378         if (hsize * sizeof(u64) != i_size_read(inode)) {
1379                 gfs2_consist_inode(dip);
1380                 return -EIO;
1381         }
1382
1383         hash = gfs2_dir_offset2hash(*offset);
1384         index = hash >> (32 - dip->i_depth);
1385
1386         lp = kmalloc(sdp->sd_hash_bsize, GFP_NOFS);
1387         if (!lp)
1388                 return -ENOMEM;
1389
1390         while (index < hsize) {
1391                 lp_offset = index & (sdp->sd_hash_ptrs - 1);
1392                 ht_offset = index - lp_offset;
1393
1394                 if (ht_offset_cur != ht_offset) {
1395                         error = gfs2_dir_read_data(dip, (char *)lp,
1396                                                 ht_offset * sizeof(__be64),
1397                                                 sdp->sd_hash_bsize, 1);
1398                         if (error != sdp->sd_hash_bsize) {
1399                                 if (error >= 0)
1400                                         error = -EIO;
1401                                 goto out;
1402                         }
1403                         ht_offset_cur = ht_offset;
1404                 }
1405
1406                 error = gfs2_dir_read_leaf(inode, offset, opaque, filldir,
1407                                            &copied, &depth,
1408                                            be64_to_cpu(lp[lp_offset]));
1409                 if (error)
1410                         break;
1411
1412                 len = 1 << (dip->i_depth - depth);
1413                 index = (index & ~(len - 1)) + len;
1414         }
1415
1416 out:
1417         kfree(lp);
1418         if (error > 0)
1419                 error = 0;
1420         return error;
1421 }
1422
1423 int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque,
1424                   filldir_t filldir)
1425 {
1426         struct gfs2_inode *dip = GFS2_I(inode);
1427         struct gfs2_sbd *sdp = GFS2_SB(inode);
1428         struct dirent_gather g;
1429         const struct gfs2_dirent **darr, *dent;
1430         struct buffer_head *dibh;
1431         int copied = 0;
1432         int error;
1433
1434         if (!dip->i_entries)
1435                 return 0;
1436
1437         if (dip->i_diskflags & GFS2_DIF_EXHASH)
1438                 return dir_e_read(inode, offset, opaque, filldir);
1439
1440         if (!gfs2_is_stuffed(dip)) {
1441                 gfs2_consist_inode(dip);
1442                 return -EIO;
1443         }
1444
1445         error = gfs2_meta_inode_buffer(dip, &dibh);
1446         if (error)
1447                 return error;
1448
1449         error = -ENOMEM;
1450         /* 96 is max number of dirents which can be stuffed into an inode */
1451         darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_NOFS);
1452         if (darr) {
1453                 g.pdent = darr;
1454                 g.offset = 0;
1455                 dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size,
1456                                         gfs2_dirent_gather, NULL, &g);
1457                 if (IS_ERR(dent)) {
1458                         error = PTR_ERR(dent);
1459                         goto out;
1460                 }
1461                 if (dip->i_entries != g.offset) {
1462                         fs_warn(sdp, "Number of entries corrupt in dir %llu, "
1463                                 "ip->i_entries (%u) != g.offset (%u)\n",
1464                                 (unsigned long long)dip->i_no_addr,
1465                                 dip->i_entries,
1466                                 g.offset);
1467                         error = -EIO;
1468                         goto out;
1469                 }
1470                 error = do_filldir_main(dip, offset, opaque, filldir, darr,
1471                                         dip->i_entries, &copied);
1472 out:
1473                 kfree(darr);
1474         }
1475
1476         if (error > 0)
1477                 error = 0;
1478
1479         brelse(dibh);
1480
1481         return error;
1482 }
1483
1484 /**
1485  * gfs2_dir_search - Search a directory
1486  * @dip: The GFS2 inode
1487  * @filename:
1488  * @inode:
1489  *
1490  * This routine searches a directory for a file or another directory.
1491  * Assumes a glock is held on dip.
1492  *
1493  * Returns: errno
1494  */
1495
1496 struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name)
1497 {
1498         struct buffer_head *bh;
1499         struct gfs2_dirent *dent;
1500         struct inode *inode;
1501
1502         dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1503         if (dent) {
1504                 if (IS_ERR(dent))
1505                         return ERR_CAST(dent);
1506                 inode = gfs2_inode_lookup(dir->i_sb,
1507                                 be16_to_cpu(dent->de_type),
1508                                 be64_to_cpu(dent->de_inum.no_addr),
1509                                 be64_to_cpu(dent->de_inum.no_formal_ino));
1510                 brelse(bh);
1511                 return inode;
1512         }
1513         return ERR_PTR(-ENOENT);
1514 }
1515
1516 int gfs2_dir_check(struct inode *dir, const struct qstr *name,
1517                    const struct gfs2_inode *ip)
1518 {
1519         struct buffer_head *bh;
1520         struct gfs2_dirent *dent;
1521         int ret = -ENOENT;
1522
1523         dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1524         if (dent) {
1525                 if (IS_ERR(dent))
1526                         return PTR_ERR(dent);
1527                 if (ip) {
1528                         if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
1529                                 goto out;
1530                         if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
1531                             ip->i_no_formal_ino)
1532                                 goto out;
1533                         if (unlikely(IF2DT(ip->i_inode.i_mode) !=
1534                             be16_to_cpu(dent->de_type))) {
1535                                 gfs2_consist_inode(GFS2_I(dir));
1536                                 ret = -EIO;
1537                                 goto out;
1538                         }
1539                 }
1540                 ret = 0;
1541 out:
1542                 brelse(bh);
1543         }
1544         return ret;
1545 }
1546
1547 static int dir_new_leaf(struct inode *inode, const struct qstr *name)
1548 {
1549         struct buffer_head *bh, *obh;
1550         struct gfs2_inode *ip = GFS2_I(inode);
1551         struct gfs2_leaf *leaf, *oleaf;
1552         int error;
1553         u32 index;
1554         u64 bn;
1555
1556         index = name->hash >> (32 - ip->i_depth);
1557         error = get_first_leaf(ip, index, &obh);
1558         if (error)
1559                 return error;
1560         do {
1561                 oleaf = (struct gfs2_leaf *)obh->b_data;
1562                 bn = be64_to_cpu(oleaf->lf_next);
1563                 if (!bn)
1564                         break;
1565                 brelse(obh);
1566                 error = get_leaf(ip, bn, &obh);
1567                 if (error)
1568                         return error;
1569         } while(1);
1570
1571         gfs2_trans_add_bh(ip->i_gl, obh, 1);
1572
1573         leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
1574         if (!leaf) {
1575                 brelse(obh);
1576                 return -ENOSPC;
1577         }
1578         oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
1579         brelse(bh);
1580         brelse(obh);
1581
1582         error = gfs2_meta_inode_buffer(ip, &bh);
1583         if (error)
1584                 return error;
1585         gfs2_trans_add_bh(ip->i_gl, bh, 1);
1586         gfs2_add_inode_blocks(&ip->i_inode, 1);
1587         gfs2_dinode_out(ip, bh->b_data);
1588         brelse(bh);
1589         return 0;
1590 }
1591
1592 /**
1593  * gfs2_dir_add - Add new filename into directory
1594  * @dip: The GFS2 inode
1595  * @filename: The new name
1596  * @inode: The inode number of the entry
1597  * @type: The type of the entry
1598  *
1599  * Returns: 0 on success, error code on failure
1600  */
1601
1602 int gfs2_dir_add(struct inode *inode, const struct qstr *name,
1603                  const struct gfs2_inode *nip, unsigned type)
1604 {
1605         struct gfs2_inode *ip = GFS2_I(inode);
1606         struct buffer_head *bh;
1607         struct gfs2_dirent *dent;
1608         struct gfs2_leaf *leaf;
1609         int error;
1610
1611         while(1) {
1612                 dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space,
1613                                           &bh);
1614                 if (dent) {
1615                         if (IS_ERR(dent))
1616                                 return PTR_ERR(dent);
1617                         dent = gfs2_init_dirent(inode, dent, name, bh);
1618                         gfs2_inum_out(nip, dent);
1619                         dent->de_type = cpu_to_be16(type);
1620                         if (ip->i_diskflags & GFS2_DIF_EXHASH) {
1621                                 leaf = (struct gfs2_leaf *)bh->b_data;
1622                                 be16_add_cpu(&leaf->lf_entries, 1);
1623                         }
1624                         brelse(bh);
1625                         error = gfs2_meta_inode_buffer(ip, &bh);
1626                         if (error)
1627                                 break;
1628                         gfs2_trans_add_bh(ip->i_gl, bh, 1);
1629                         ip->i_entries++;
1630                         ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
1631                         gfs2_dinode_out(ip, bh->b_data);
1632                         brelse(bh);
1633                         error = 0;
1634                         break;
1635                 }
1636                 if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) {
1637                         error = dir_make_exhash(inode);
1638                         if (error)
1639                                 break;
1640                         continue;
1641                 }
1642                 error = dir_split_leaf(inode, name);
1643                 if (error == 0)
1644                         continue;
1645                 if (error < 0)
1646                         break;
1647                 if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
1648                         error = dir_double_exhash(ip);
1649                         if (error)
1650                                 break;
1651                         error = dir_split_leaf(inode, name);
1652                         if (error < 0)
1653                                 break;
1654                         if (error == 0)
1655                                 continue;
1656                 }
1657                 error = dir_new_leaf(inode, name);
1658                 if (!error)
1659                         continue;
1660                 error = -ENOSPC;
1661                 break;
1662         }
1663         return error;
1664 }
1665
1666
1667 /**
1668  * gfs2_dir_del - Delete a directory entry
1669  * @dip: The GFS2 inode
1670  * @filename: The filename
1671  *
1672  * Returns: 0 on success, error code on failure
1673  */
1674
1675 int gfs2_dir_del(struct gfs2_inode *dip, const struct qstr *name)
1676 {
1677         struct gfs2_dirent *dent, *prev = NULL;
1678         struct buffer_head *bh;
1679         int error;
1680
1681         /* Returns _either_ the entry (if its first in block) or the
1682            previous entry otherwise */
1683         dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh);
1684         if (!dent) {
1685                 gfs2_consist_inode(dip);
1686                 return -EIO;
1687         }
1688         if (IS_ERR(dent)) {
1689                 gfs2_consist_inode(dip);
1690                 return PTR_ERR(dent);
1691         }
1692         /* If not first in block, adjust pointers accordingly */
1693         if (gfs2_dirent_find(dent, name, NULL) == 0) {
1694                 prev = dent;
1695                 dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
1696         }
1697
1698         dirent_del(dip, bh, prev, dent);
1699         if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1700                 struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
1701                 u16 entries = be16_to_cpu(leaf->lf_entries);
1702                 if (!entries)
1703                         gfs2_consist_inode(dip);
1704                 leaf->lf_entries = cpu_to_be16(--entries);
1705         }
1706         brelse(bh);
1707
1708         error = gfs2_meta_inode_buffer(dip, &bh);
1709         if (error)
1710                 return error;
1711
1712         if (!dip->i_entries)
1713                 gfs2_consist_inode(dip);
1714         gfs2_trans_add_bh(dip->i_gl, bh, 1);
1715         dip->i_entries--;
1716         dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1717         gfs2_dinode_out(dip, bh->b_data);
1718         brelse(bh);
1719         mark_inode_dirty(&dip->i_inode);
1720
1721         return error;
1722 }
1723
1724 /**
1725  * gfs2_dir_mvino - Change inode number of directory entry
1726  * @dip: The GFS2 inode
1727  * @filename:
1728  * @new_inode:
1729  *
1730  * This routine changes the inode number of a directory entry.  It's used
1731  * by rename to change ".." when a directory is moved.
1732  * Assumes a glock is held on dvp.
1733  *
1734  * Returns: errno
1735  */
1736
1737 int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
1738                    const struct gfs2_inode *nip, unsigned int new_type)
1739 {
1740         struct buffer_head *bh;
1741         struct gfs2_dirent *dent;
1742         int error;
1743
1744         dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh);
1745         if (!dent) {
1746                 gfs2_consist_inode(dip);
1747                 return -EIO;
1748         }
1749         if (IS_ERR(dent))
1750                 return PTR_ERR(dent);
1751
1752         gfs2_trans_add_bh(dip->i_gl, bh, 1);
1753         gfs2_inum_out(nip, dent);
1754         dent->de_type = cpu_to_be16(new_type);
1755
1756         if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1757                 brelse(bh);
1758                 error = gfs2_meta_inode_buffer(dip, &bh);
1759                 if (error)
1760                         return error;
1761                 gfs2_trans_add_bh(dip->i_gl, bh, 1);
1762         }
1763
1764         dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1765         gfs2_dinode_out(dip, bh->b_data);
1766         brelse(bh);
1767         return 0;
1768 }
1769
1770 /**
1771  * foreach_leaf - call a function for each leaf in a directory
1772  * @dip: the directory
1773  * @lc: the function to call for each each
1774  * @data: private data to pass to it
1775  *
1776  * Returns: errno
1777  */
1778
1779 static int foreach_leaf(struct gfs2_inode *dip, leaf_call_t lc, void *data)
1780 {
1781         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1782         struct buffer_head *bh;
1783         struct gfs2_leaf *leaf;
1784         u32 hsize, len;
1785         u32 ht_offset, lp_offset, ht_offset_cur = -1;
1786         u32 index = 0;
1787         __be64 *lp;
1788         u64 leaf_no;
1789         int error = 0;
1790
1791         hsize = 1 << dip->i_depth;
1792         if (hsize * sizeof(u64) != i_size_read(&dip->i_inode)) {
1793                 gfs2_consist_inode(dip);
1794                 return -EIO;
1795         }
1796
1797         lp = kmalloc(sdp->sd_hash_bsize, GFP_NOFS);
1798         if (!lp)
1799                 return -ENOMEM;
1800
1801         while (index < hsize) {
1802                 lp_offset = index & (sdp->sd_hash_ptrs - 1);
1803                 ht_offset = index - lp_offset;
1804
1805                 if (ht_offset_cur != ht_offset) {
1806                         error = gfs2_dir_read_data(dip, (char *)lp,
1807                                                 ht_offset * sizeof(__be64),
1808                                                 sdp->sd_hash_bsize, 1);
1809                         if (error != sdp->sd_hash_bsize) {
1810                                 if (error >= 0)
1811                                         error = -EIO;
1812                                 goto out;
1813                         }
1814                         ht_offset_cur = ht_offset;
1815                 }
1816
1817                 leaf_no = be64_to_cpu(lp[lp_offset]);
1818                 if (leaf_no) {
1819                         error = get_leaf(dip, leaf_no, &bh);
1820                         if (error)
1821                                 goto out;
1822                         leaf = (struct gfs2_leaf *)bh->b_data;
1823                         len = 1 << (dip->i_depth - be16_to_cpu(leaf->lf_depth));
1824                         brelse(bh);
1825
1826                         error = lc(dip, index, len, leaf_no, data);
1827                         if (error)
1828                                 goto out;
1829
1830                         index = (index & ~(len - 1)) + len;
1831                 } else
1832                         index++;
1833         }
1834
1835         if (index != hsize) {
1836                 gfs2_consist_inode(dip);
1837                 error = -EIO;
1838         }
1839
1840 out:
1841         kfree(lp);
1842
1843         return error;
1844 }
1845
1846 /**
1847  * leaf_dealloc - Deallocate a directory leaf
1848  * @dip: the directory
1849  * @index: the hash table offset in the directory
1850  * @len: the number of pointers to this leaf
1851  * @leaf_no: the leaf number
1852  * @data: not used
1853  *
1854  * Returns: errno
1855  */
1856
1857 static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len,
1858                         u64 leaf_no, void *data)
1859 {
1860         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1861         struct gfs2_leaf *tmp_leaf;
1862         struct gfs2_rgrp_list rlist;
1863         struct buffer_head *bh, *dibh;
1864         u64 blk, nblk;
1865         unsigned int rg_blocks = 0, l_blocks = 0;
1866         char *ht;
1867         unsigned int x, size = len * sizeof(u64);
1868         int error;
1869
1870         memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
1871
1872         ht = kzalloc(size, GFP_NOFS);
1873         if (!ht)
1874                 return -ENOMEM;
1875
1876         if (!gfs2_alloc_get(dip)) {
1877                 error = -ENOMEM;
1878                 goto out;
1879         }
1880
1881         error = gfs2_quota_hold(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
1882         if (error)
1883                 goto out_put;
1884
1885         error = gfs2_rindex_hold(sdp, &dip->i_alloc->al_ri_gh);
1886         if (error)
1887                 goto out_qs;
1888
1889         /*  Count the number of leaves  */
1890
1891         for (blk = leaf_no; blk; blk = nblk) {
1892                 error = get_leaf(dip, blk, &bh);
1893                 if (error)
1894                         goto out_rlist;
1895                 tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1896                 nblk = be64_to_cpu(tmp_leaf->lf_next);
1897                 brelse(bh);
1898
1899                 gfs2_rlist_add(sdp, &rlist, blk);
1900                 l_blocks++;
1901         }
1902
1903         gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
1904
1905         for (x = 0; x < rlist.rl_rgrps; x++) {
1906                 struct gfs2_rgrpd *rgd;
1907                 rgd = rlist.rl_ghs[x].gh_gl->gl_object;
1908                 rg_blocks += rgd->rd_length;
1909         }
1910
1911         error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
1912         if (error)
1913                 goto out_rlist;
1914
1915         error = gfs2_trans_begin(sdp,
1916                         rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
1917                         RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
1918         if (error)
1919                 goto out_rg_gunlock;
1920
1921         for (blk = leaf_no; blk; blk = nblk) {
1922                 error = get_leaf(dip, blk, &bh);
1923                 if (error)
1924                         goto out_end_trans;
1925                 tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1926                 nblk = be64_to_cpu(tmp_leaf->lf_next);
1927                 brelse(bh);
1928
1929                 gfs2_free_meta(dip, blk, 1);
1930                 gfs2_add_inode_blocks(&dip->i_inode, -1);
1931         }
1932
1933         error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size);
1934         if (error != size) {
1935                 if (error >= 0)
1936                         error = -EIO;
1937                 goto out_end_trans;
1938         }
1939
1940         error = gfs2_meta_inode_buffer(dip, &dibh);
1941         if (error)
1942                 goto out_end_trans;
1943
1944         gfs2_trans_add_bh(dip->i_gl, dibh, 1);
1945         gfs2_dinode_out(dip, dibh->b_data);
1946         brelse(dibh);
1947
1948 out_end_trans:
1949         gfs2_trans_end(sdp);
1950 out_rg_gunlock:
1951         gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
1952 out_rlist:
1953         gfs2_rlist_free(&rlist);
1954         gfs2_glock_dq_uninit(&dip->i_alloc->al_ri_gh);
1955 out_qs:
1956         gfs2_quota_unhold(dip);
1957 out_put:
1958         gfs2_alloc_put(dip);
1959 out:
1960         kfree(ht);
1961         return error;
1962 }
1963
1964 /**
1965  * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory
1966  * @dip: the directory
1967  *
1968  * Dealloc all on-disk directory leaves to FREEMETA state
1969  * Change on-disk inode type to "regular file"
1970  *
1971  * Returns: errno
1972  */
1973
1974 int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip)
1975 {
1976         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1977         struct buffer_head *bh;
1978         int error;
1979
1980         /* Dealloc on-disk leaves to FREEMETA state */
1981         error = foreach_leaf(dip, leaf_dealloc, NULL);
1982         if (error)
1983                 return error;
1984
1985         /* Make this a regular file in case we crash.
1986            (We don't want to free these blocks a second time.)  */
1987
1988         error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1989         if (error)
1990                 return error;
1991
1992         error = gfs2_meta_inode_buffer(dip, &bh);
1993         if (!error) {
1994                 gfs2_trans_add_bh(dip->i_gl, bh, 1);
1995                 ((struct gfs2_dinode *)bh->b_data)->di_mode =
1996                                                 cpu_to_be32(S_IFREG);
1997                 brelse(bh);
1998         }
1999
2000         gfs2_trans_end(sdp);
2001
2002         return error;
2003 }
2004
2005 /**
2006  * gfs2_diradd_alloc_required - find if adding entry will require an allocation
2007  * @ip: the file being written to
2008  * @filname: the filename that's going to be added
2009  *
2010  * Returns: 1 if alloc required, 0 if not, -ve on error
2011  */
2012
2013 int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name)
2014 {
2015         struct gfs2_dirent *dent;
2016         struct buffer_head *bh;
2017
2018         dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
2019         if (!dent) {
2020                 return 1;
2021         }
2022         if (IS_ERR(dent))
2023                 return PTR_ERR(dent);
2024         brelse(bh);
2025         return 0;
2026 }
2027