fs/gfs2/dir.c

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