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