fs/gfs2/dir.c

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This source file includes following definitions.
gfs2_dir_get_new_buffer
gfs2_dir_get_existing_buffer
gfs2_dir_write_stuffed
gfs2_dir_write_data
gfs2_dir_read_stuffed
gfs2_dir_read_data
gfs2_dir_get_hash_table
gfs2_dir_hash_inval
gfs2_dirent_sentinel
__gfs2_dirent_find
gfs2_dirent_find
gfs2_dirent_prev
gfs2_dirent_last
gfs2_dirent_find_offset
gfs2_dirent_find_space
gfs2_dirent_gather
gfs2_check_dirent
gfs2_dirent_offset
gfs2_dirent_scan
dirent_check_reclen
dirent_next
dirent_del
do_init_dirent
gfs2_init_dirent
gfs2_dirent_split_alloc
get_leaf
get_leaf_nr
get_first_leaf
gfs2_dirent_search
new_leaf
dir_make_exhash
dir_split_leaf
dir_double_exhash
compare_dents
do_filldir_main
gfs2_alloc_sort_buffer
gfs2_set_cookies
gfs2_dir_read_leaf
gfs2_dir_readahead
dir_e_read
gfs2_dir_read
gfs2_dir_search
gfs2_dir_check
dir_new_leaf
gfs2_inode_ra_len
gfs2_dir_add
gfs2_dir_del
gfs2_dir_mvino
leaf_dealloc
gfs2_dir_exhash_dealloc
gfs2_diradd_alloc_required
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   4  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   5  */
   6 
   7 /*
   8  * Implements Extendible Hashing as described in:
   9  *   "Extendible Hashing" by Fagin, et al in
  10  *     __ACM Trans. on Database Systems__, Sept 1979.
  11  *
  12  *
  13  * Here's the layout of dirents which is essentially the same as that of ext2
  14  * within a single block. The field de_name_len is the number of bytes
  15  * actually required for the name (no null terminator). The field de_rec_len
  16  * is the number of bytes allocated to the dirent. The offset of the next
  17  * dirent in the block is (dirent + dirent->de_rec_len). When a dirent is
  18  * deleted, the preceding dirent inherits its allocated space, ie
  19  * prev->de_rec_len += deleted->de_rec_len. Since the next dirent is obtained
  20  * by adding de_rec_len to the current dirent, this essentially causes the
  21  * deleted dirent to get jumped over when iterating through all the dirents.
  22  *
  23  * When deleting the first dirent in a block, there is no previous dirent so
  24  * the field de_ino is set to zero to designate it as deleted. When allocating
  25  * a dirent, gfs2_dirent_alloc iterates through the dirents in a block. If the
  26  * first dirent has (de_ino == 0) and de_rec_len is large enough, this first
  27  * dirent is allocated. Otherwise it must go through all the 'used' dirents
  28  * searching for one in which the amount of total space minus the amount of
  29  * used space will provide enough space for the new dirent.
  30  *
  31  * There are two types of blocks in which dirents reside. In a stuffed dinode,
  32  * the dirents begin at offset sizeof(struct gfs2_dinode) from the beginning of
  33  * the block.  In leaves, they begin at offset sizeof(struct gfs2_leaf) from the
  34  * beginning of the leaf block. The dirents reside in leaves when
  35  *
  36  * dip->i_diskflags & GFS2_DIF_EXHASH is true
  37  *
  38  * Otherwise, the dirents are "linear", within a single stuffed dinode block.
  39  *
  40  * When the dirents are in leaves, the actual contents of the directory file are
  41  * used as an array of 64-bit block pointers pointing to the leaf blocks. The
  42  * dirents are NOT in the directory file itself. There can be more than one
  43  * block pointer in the array that points to the same leaf. In fact, when a
  44  * directory is first converted from linear to exhash, all of the pointers
  45  * point to the same leaf.
  46  *
  47  * When a leaf is completely full, the size of the hash table can be
  48  * doubled unless it is already at the maximum size which is hard coded into
  49  * GFS2_DIR_MAX_DEPTH. After that, leaves are chained together in a linked list,
  50  * but never before the maximum hash table size has been reached.
  51  */
  52 
  53 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  54 
  55 #include <linux/slab.h>
  56 #include <linux/spinlock.h>
  57 #include <linux/buffer_head.h>
  58 #include <linux/sort.h>
  59 #include <linux/gfs2_ondisk.h>
  60 #include <linux/crc32.h>
  61 #include <linux/vmalloc.h>
  62 #include <linux/bio.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 MAX_RA_BLOCKS 32 /* max read-ahead blocks */
  80 
  81 #define gfs2_disk_hash2offset(h) (((u64)(h)) >> 1)
  82 #define gfs2_dir_offset2hash(p) ((u32)(((u64)(p)) << 1))
  83 #define GFS2_HASH_INDEX_MASK 0xffffc000
  84 #define GFS2_USE_HASH_FLAG 0x2000
  85 
  86 struct qstr gfs2_qdot __read_mostly;
  87 struct qstr gfs2_qdotdot __read_mostly;
  88 
  89 typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent,
  90                             const struct qstr *name, void *opaque);
  91 
  92 int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
  93                             struct buffer_head **bhp)
  94 {
  95         struct buffer_head *bh;
  96 
  97         bh = gfs2_meta_new(ip->i_gl, block);
  98         gfs2_trans_add_meta(ip->i_gl, bh);
  99         gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
 100         gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
 101         *bhp = bh;
 102         return 0;
 103 }
 104 
 105 static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, u64 block,
 106                                         struct buffer_head **bhp)
 107 {
 108         struct buffer_head *bh;
 109         int error;
 110 
 111         error = gfs2_meta_read(ip->i_gl, block, DIO_WAIT, 0, &bh);
 112         if (error)
 113                 return error;
 114         if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_JD)) {
 115                 brelse(bh);
 116                 return -EIO;
 117         }
 118         *bhp = bh;
 119         return 0;
 120 }
 121 
 122 static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
 123                                   unsigned int offset, unsigned int size)
 124 {
 125         struct buffer_head *dibh;
 126         int error;
 127 
 128         error = gfs2_meta_inode_buffer(ip, &dibh);
 129         if (error)
 130                 return error;
 131 
 132         gfs2_trans_add_meta(ip->i_gl, dibh);
 133         memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
 134         if (ip->i_inode.i_size < offset + size)
 135                 i_size_write(&ip->i_inode, offset + size);
 136         ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
 137         gfs2_dinode_out(ip, dibh->b_data);
 138 
 139         brelse(dibh);
 140 
 141         return size;
 142 }
 143 
 144 
 145 
 146 /**
 147  * gfs2_dir_write_data - Write directory information to the inode
 148  * @ip: The GFS2 inode
 149  * @buf: The buffer containing information to be written
 150  * @offset: The file offset to start writing at
 151  * @size: The amount of data to write
 152  *
 153  * Returns: The number of bytes correctly written or error code
 154  */
 155 static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
 156                                u64 offset, unsigned int size)
 157 {
 158         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 159         struct buffer_head *dibh;
 160         u64 lblock, dblock;
 161         u32 extlen = 0;
 162         unsigned int o;
 163         int copied = 0;
 164         int error = 0;
 165         int new = 0;
 166 
 167         if (!size)
 168                 return 0;
 169 
 170         if (gfs2_is_stuffed(ip) && offset + size <= gfs2_max_stuffed_size(ip))
 171                 return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
 172                                               size);
 173 
 174         if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
 175                 return -EINVAL;
 176 
 177         if (gfs2_is_stuffed(ip)) {
 178                 error = gfs2_unstuff_dinode(ip, NULL);
 179                 if (error)
 180                         return error;
 181         }
 182 
 183         lblock = offset;
 184         o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
 185 
 186         while (copied < size) {
 187                 unsigned int amount;
 188                 struct buffer_head *bh;
 189 
 190                 amount = size - copied;
 191                 if (amount > sdp->sd_sb.sb_bsize - o)
 192                         amount = sdp->sd_sb.sb_bsize - o;
 193 
 194                 if (!extlen) {
 195                         new = 1;
 196                         error = gfs2_extent_map(&ip->i_inode, lblock, &new,
 197                                                 &dblock, &extlen);
 198                         if (error)
 199                                 goto fail;
 200                         error = -EIO;
 201                         if (gfs2_assert_withdraw(sdp, dblock))
 202                                 goto fail;
 203                 }
 204 
 205                 if (amount == sdp->sd_jbsize || new)
 206                         error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
 207                 else
 208                         error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
 209 
 210                 if (error)
 211                         goto fail;
 212 
 213                 gfs2_trans_add_meta(ip->i_gl, bh);
 214                 memcpy(bh->b_data + o, buf, amount);
 215                 brelse(bh);
 216 
 217                 buf += amount;
 218                 copied += amount;
 219                 lblock++;
 220                 dblock++;
 221                 extlen--;
 222 
 223                 o = sizeof(struct gfs2_meta_header);
 224         }
 225 
 226 out:
 227         error = gfs2_meta_inode_buffer(ip, &dibh);
 228         if (error)
 229                 return error;
 230 
 231         if (ip->i_inode.i_size < offset + copied)
 232                 i_size_write(&ip->i_inode, offset + copied);
 233         ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
 234 
 235         gfs2_trans_add_meta(ip->i_gl, dibh);
 236         gfs2_dinode_out(ip, dibh->b_data);
 237         brelse(dibh);
 238 
 239         return copied;
 240 fail:
 241         if (copied)
 242                 goto out;
 243         return error;
 244 }
 245 
 246 static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, __be64 *buf,
 247                                  unsigned int size)
 248 {
 249         struct buffer_head *dibh;
 250         int error;
 251 
 252         error = gfs2_meta_inode_buffer(ip, &dibh);
 253         if (!error) {
 254                 memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size);
 255                 brelse(dibh);
 256         }
 257 
 258         return (error) ? error : size;
 259 }
 260 
 261 
 262 /**
 263  * gfs2_dir_read_data - Read a data from a directory inode
 264  * @ip: The GFS2 Inode
 265  * @buf: The buffer to place result into
 266  * @size: Amount of data to transfer
 267  *
 268  * Returns: The amount of data actually copied or the error
 269  */
 270 static int gfs2_dir_read_data(struct gfs2_inode *ip, __be64 *buf,
 271                               unsigned int size)
 272 {
 273         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 274         u64 lblock, dblock;
 275         u32 extlen = 0;
 276         unsigned int o;
 277         int copied = 0;
 278         int error = 0;
 279 
 280         if (gfs2_is_stuffed(ip))
 281                 return gfs2_dir_read_stuffed(ip, buf, size);
 282 
 283         if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
 284                 return -EINVAL;
 285 
 286         lblock = 0;
 287         o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
 288 
 289         while (copied < size) {
 290                 unsigned int amount;
 291                 struct buffer_head *bh;
 292                 int new;
 293 
 294                 amount = size - copied;
 295                 if (amount > sdp->sd_sb.sb_bsize - o)
 296                         amount = sdp->sd_sb.sb_bsize - o;
 297 
 298                 if (!extlen) {
 299                         new = 0;
 300                         error = gfs2_extent_map(&ip->i_inode, lblock, &new,
 301                                                 &dblock, &extlen);
 302                         if (error || !dblock)
 303                                 goto fail;
 304                         BUG_ON(extlen < 1);
 305                         bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
 306                 } else {
 307                         error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, 0, &bh);
 308                         if (error)
 309                                 goto fail;
 310                 }
 311                 error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD);
 312                 if (error) {
 313                         brelse(bh);
 314                         goto fail;
 315                 }
 316                 dblock++;
 317                 extlen--;
 318                 memcpy(buf, bh->b_data + o, amount);
 319                 brelse(bh);
 320                 buf += (amount/sizeof(__be64));
 321                 copied += amount;
 322                 lblock++;
 323                 o = sizeof(struct gfs2_meta_header);
 324         }
 325 
 326         return copied;
 327 fail:
 328         return (copied) ? copied : error;
 329 }
 330 
 331 /**
 332  * gfs2_dir_get_hash_table - Get pointer to the dir hash table
 333  * @ip: The inode in question
 334  *
 335  * Returns: The hash table or an error
 336  */
 337 
 338 static __be64 *gfs2_dir_get_hash_table(struct gfs2_inode *ip)
 339 {
 340         struct inode *inode = &ip->i_inode;
 341         int ret;
 342         u32 hsize;
 343         __be64 *hc;
 344 
 345         BUG_ON(!(ip->i_diskflags & GFS2_DIF_EXHASH));
 346 
 347         hc = ip->i_hash_cache;
 348         if (hc)
 349                 return hc;
 350 
 351         hsize = BIT(ip->i_depth);
 352         hsize *= sizeof(__be64);
 353         if (hsize != i_size_read(&ip->i_inode)) {
 354                 gfs2_consist_inode(ip);
 355                 return ERR_PTR(-EIO);
 356         }
 357 
 358         hc = kmalloc(hsize, GFP_NOFS | __GFP_NOWARN);
 359         if (hc == NULL)
 360                 hc = __vmalloc(hsize, GFP_NOFS, PAGE_KERNEL);
 361 
 362         if (hc == NULL)
 363                 return ERR_PTR(-ENOMEM);
 364 
 365         ret = gfs2_dir_read_data(ip, hc, hsize);
 366         if (ret < 0) {
 367                 kvfree(hc);
 368                 return ERR_PTR(ret);
 369         }
 370 
 371         spin_lock(&inode->i_lock);
 372         if (likely(!ip->i_hash_cache)) {
 373                 ip->i_hash_cache = hc;
 374                 hc = NULL;
 375         }
 376         spin_unlock(&inode->i_lock);
 377         kvfree(hc);
 378 
 379         return ip->i_hash_cache;
 380 }
 381 
 382 /**
 383  * gfs2_dir_hash_inval - Invalidate dir hash
 384  * @ip: The directory inode
 385  *
 386  * Must be called with an exclusive glock, or during glock invalidation.
 387  */
 388 void gfs2_dir_hash_inval(struct gfs2_inode *ip)
 389 {
 390         __be64 *hc;
 391 
 392         spin_lock(&ip->i_inode.i_lock);
 393         hc = ip->i_hash_cache;
 394         ip->i_hash_cache = NULL;
 395         spin_unlock(&ip->i_inode.i_lock);
 396 
 397         kvfree(hc);
 398 }
 399 
 400 static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent)
 401 {
 402         return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0;
 403 }
 404 
 405 static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
 406                                      const struct qstr *name, int ret)
 407 {
 408         if (!gfs2_dirent_sentinel(dent) &&
 409             be32_to_cpu(dent->de_hash) == name->hash &&
 410             be16_to_cpu(dent->de_name_len) == name->len &&
 411             memcmp(dent+1, name->name, name->len) == 0)
 412                 return ret;
 413         return 0;
 414 }
 415 
 416 static int gfs2_dirent_find(const struct gfs2_dirent *dent,
 417                             const struct qstr *name,
 418                             void *opaque)
 419 {
 420         return __gfs2_dirent_find(dent, name, 1);
 421 }
 422 
 423 static int gfs2_dirent_prev(const struct gfs2_dirent *dent,
 424                             const struct qstr *name,
 425                             void *opaque)
 426 {
 427         return __gfs2_dirent_find(dent, name, 2);
 428 }
 429 
 430 /*
 431  * name->name holds ptr to start of block.
 432  * name->len holds size of block.
 433  */
 434 static int gfs2_dirent_last(const struct gfs2_dirent *dent,
 435                             const struct qstr *name,
 436                             void *opaque)
 437 {
 438         const char *start = name->name;
 439         const char *end = (const char *)dent + be16_to_cpu(dent->de_rec_len);
 440         if (name->len == (end - start))
 441                 return 1;
 442         return 0;
 443 }
 444 
 445 /* Look for the dirent that contains the offset specified in data. Once we
 446  * find that dirent, there must be space available there for the new dirent */
 447 static int gfs2_dirent_find_offset(const struct gfs2_dirent *dent,
 448                                   const struct qstr *name,
 449                                   void *ptr)
 450 {
 451         unsigned required = GFS2_DIRENT_SIZE(name->len);
 452         unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 453         unsigned totlen = be16_to_cpu(dent->de_rec_len);
 454 
 455         if (ptr < (void *)dent || ptr >= (void *)dent + totlen)
 456                 return 0;
 457         if (gfs2_dirent_sentinel(dent))
 458                 actual = 0;
 459         if (ptr < (void *)dent + actual)
 460                 return -1;
 461         if ((void *)dent + totlen >= ptr + required)
 462                 return 1;
 463         return -1;
 464 }
 465 
 466 static int gfs2_dirent_find_space(const struct gfs2_dirent *dent,
 467                                   const struct qstr *name,
 468                                   void *opaque)
 469 {
 470         unsigned required = GFS2_DIRENT_SIZE(name->len);
 471         unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 472         unsigned totlen = be16_to_cpu(dent->de_rec_len);
 473 
 474         if (gfs2_dirent_sentinel(dent))
 475                 actual = 0;
 476         if (totlen - actual >= required)
 477                 return 1;
 478         return 0;
 479 }
 480 
 481 struct dirent_gather {
 482         const struct gfs2_dirent **pdent;
 483         unsigned offset;
 484 };
 485 
 486 static int gfs2_dirent_gather(const struct gfs2_dirent *dent,
 487                               const struct qstr *name,
 488                               void *opaque)
 489 {
 490         struct dirent_gather *g = opaque;
 491         if (!gfs2_dirent_sentinel(dent)) {
 492                 g->pdent[g->offset++] = dent;
 493         }
 494         return 0;
 495 }
 496 
 497 /*
 498  * Other possible things to check:
 499  * - Inode located within filesystem size (and on valid block)
 500  * - Valid directory entry type
 501  * Not sure how heavy-weight we want to make this... could also check
 502  * hash is correct for example, but that would take a lot of extra time.
 503  * For now the most important thing is to check that the various sizes
 504  * are correct.
 505  */
 506 static int gfs2_check_dirent(struct gfs2_sbd *sdp,
 507                              struct gfs2_dirent *dent, unsigned int offset,
 508                              unsigned int size, unsigned int len, int first)
 509 {
 510         const char *msg = "gfs2_dirent too small";
 511         if (unlikely(size < sizeof(struct gfs2_dirent)))
 512                 goto error;
 513         msg = "gfs2_dirent misaligned";
 514         if (unlikely(offset & 0x7))
 515                 goto error;
 516         msg = "gfs2_dirent points beyond end of block";
 517         if (unlikely(offset + size > len))
 518                 goto error;
 519         msg = "zero inode number";
 520         if (unlikely(!first && gfs2_dirent_sentinel(dent)))
 521                 goto error;
 522         msg = "name length is greater than space in dirent";
 523         if (!gfs2_dirent_sentinel(dent) &&
 524             unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
 525                      size))
 526                 goto error;
 527         return 0;
 528 error:
 529         fs_warn(sdp, "%s: %s (%s)\n",
 530                 __func__, msg, first ? "first in block" : "not first in block");
 531         return -EIO;
 532 }
 533 
 534 static int gfs2_dirent_offset(struct gfs2_sbd *sdp, const void *buf)
 535 {
 536         const struct gfs2_meta_header *h = buf;
 537         int offset;
 538 
 539         BUG_ON(buf == NULL);
 540 
 541         switch(be32_to_cpu(h->mh_type)) {
 542         case GFS2_METATYPE_LF:
 543                 offset = sizeof(struct gfs2_leaf);
 544                 break;
 545         case GFS2_METATYPE_DI:
 546                 offset = sizeof(struct gfs2_dinode);
 547                 break;
 548         default:
 549                 goto wrong_type;
 550         }
 551         return offset;
 552 wrong_type:
 553         fs_warn(sdp, "%s: wrong block type %u\n", __func__,
 554                 be32_to_cpu(h->mh_type));
 555         return -1;
 556 }
 557 
 558 static struct gfs2_dirent *gfs2_dirent_scan(struct inode *inode, void *buf,
 559                                             unsigned int len, gfs2_dscan_t scan,
 560                                             const struct qstr *name,
 561                                             void *opaque)
 562 {
 563         struct gfs2_dirent *dent, *prev;
 564         unsigned offset;
 565         unsigned size;
 566         int ret = 0;
 567 
 568         ret = gfs2_dirent_offset(GFS2_SB(inode), buf);
 569         if (ret < 0)
 570                 goto consist_inode;
 571 
 572         offset = ret;
 573         prev = NULL;
 574         dent = buf + offset;
 575         size = be16_to_cpu(dent->de_rec_len);
 576         if (gfs2_check_dirent(GFS2_SB(inode), dent, offset, size, len, 1))
 577                 goto consist_inode;
 578         do {
 579                 ret = scan(dent, name, opaque);
 580                 if (ret)
 581                         break;
 582                 offset += size;
 583                 if (offset == len)
 584                         break;
 585                 prev = dent;
 586                 dent = buf + offset;
 587                 size = be16_to_cpu(dent->de_rec_len);
 588                 if (gfs2_check_dirent(GFS2_SB(inode), dent, offset, size,
 589                                       len, 0))
 590                         goto consist_inode;
 591         } while(1);
 592 
 593         switch(ret) {
 594         case 0:
 595                 return NULL;
 596         case 1:
 597                 return dent;
 598         case 2:
 599                 return prev ? prev : dent;
 600         default:
 601                 BUG_ON(ret > 0);
 602                 return ERR_PTR(ret);
 603         }
 604 
 605 consist_inode:
 606         gfs2_consist_inode(GFS2_I(inode));
 607         return ERR_PTR(-EIO);
 608 }
 609 
 610 static int dirent_check_reclen(struct gfs2_inode *dip,
 611                                const struct gfs2_dirent *d, const void *end_p)
 612 {
 613         const void *ptr = d;
 614         u16 rec_len = be16_to_cpu(d->de_rec_len);
 615 
 616         if (unlikely(rec_len < sizeof(struct gfs2_dirent)))
 617                 goto broken;
 618         ptr += rec_len;
 619         if (ptr < end_p)
 620                 return rec_len;
 621         if (ptr == end_p)
 622                 return -ENOENT;
 623 broken:
 624         gfs2_consist_inode(dip);
 625         return -EIO;
 626 }
 627 
 628 /**
 629  * dirent_next - Next dirent
 630  * @dip: the directory
 631  * @bh: The buffer
 632  * @dent: Pointer to list of dirents
 633  *
 634  * Returns: 0 on success, error code otherwise
 635  */
 636 
 637 static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh,
 638                        struct gfs2_dirent **dent)
 639 {
 640         struct gfs2_dirent *cur = *dent, *tmp;
 641         char *bh_end = bh->b_data + bh->b_size;
 642         int ret;
 643 
 644         ret = dirent_check_reclen(dip, cur, bh_end);
 645         if (ret < 0)
 646                 return ret;
 647 
 648         tmp = (void *)cur + ret;
 649         ret = dirent_check_reclen(dip, tmp, bh_end);
 650         if (ret == -EIO)
 651                 return ret;
 652 
 653         /* Only the first dent could ever have de_inum.no_addr == 0 */
 654         if (gfs2_dirent_sentinel(tmp)) {
 655                 gfs2_consist_inode(dip);
 656                 return -EIO;
 657         }
 658 
 659         *dent = tmp;
 660         return 0;
 661 }
 662 
 663 /**
 664  * dirent_del - Delete a dirent
 665  * @dip: The GFS2 inode
 666  * @bh: The buffer
 667  * @prev: The previous dirent
 668  * @cur: The current dirent
 669  *
 670  */
 671 
 672 static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh,
 673                        struct gfs2_dirent *prev, struct gfs2_dirent *cur)
 674 {
 675         u16 cur_rec_len, prev_rec_len;
 676 
 677         if (gfs2_dirent_sentinel(cur)) {
 678                 gfs2_consist_inode(dip);
 679                 return;
 680         }
 681 
 682         gfs2_trans_add_meta(dip->i_gl, bh);
 683 
 684         /* If there is no prev entry, this is the first entry in the block.
 685            The de_rec_len is already as big as it needs to be.  Just zero
 686            out the inode number and return.  */
 687 
 688         if (!prev) {
 689                 cur->de_inum.no_addr = 0;
 690                 cur->de_inum.no_formal_ino = 0;
 691                 return;
 692         }
 693 
 694         /*  Combine this dentry with the previous one.  */
 695 
 696         prev_rec_len = be16_to_cpu(prev->de_rec_len);
 697         cur_rec_len = be16_to_cpu(cur->de_rec_len);
 698 
 699         if ((char *)prev + prev_rec_len != (char *)cur)
 700                 gfs2_consist_inode(dip);
 701         if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size)
 702                 gfs2_consist_inode(dip);
 703 
 704         prev_rec_len += cur_rec_len;
 705         prev->de_rec_len = cpu_to_be16(prev_rec_len);
 706 }
 707 
 708 
 709 static struct gfs2_dirent *do_init_dirent(struct inode *inode,
 710                                           struct gfs2_dirent *dent,
 711                                           const struct qstr *name,
 712                                           struct buffer_head *bh,
 713                                           unsigned offset)
 714 {
 715         struct gfs2_inode *ip = GFS2_I(inode);
 716         struct gfs2_dirent *ndent;
 717         unsigned totlen;
 718 
 719         totlen = be16_to_cpu(dent->de_rec_len);
 720         BUG_ON(offset + name->len > totlen);
 721         gfs2_trans_add_meta(ip->i_gl, bh);
 722         ndent = (struct gfs2_dirent *)((char *)dent + offset);
 723         dent->de_rec_len = cpu_to_be16(offset);
 724         gfs2_qstr2dirent(name, totlen - offset, ndent);
 725         return ndent;
 726 }
 727 
 728 
 729 /*
 730  * Takes a dent from which to grab space as an argument. Returns the
 731  * newly created dent.
 732  */
 733 static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
 734                                             struct gfs2_dirent *dent,
 735                                             const struct qstr *name,
 736                                             struct buffer_head *bh)
 737 {
 738         unsigned offset = 0;
 739 
 740         if (!gfs2_dirent_sentinel(dent))
 741                 offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 742         return do_init_dirent(inode, dent, name, bh, offset);
 743 }
 744 
 745 static struct gfs2_dirent *gfs2_dirent_split_alloc(struct inode *inode,
 746                                                    struct buffer_head *bh,
 747                                                    const struct qstr *name,
 748                                                    void *ptr)
 749 {
 750         struct gfs2_dirent *dent;
 751         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 752                                 gfs2_dirent_find_offset, name, ptr);
 753         if (IS_ERR_OR_NULL(dent))
 754                 return dent;
 755         return do_init_dirent(inode, dent, name, bh,
 756                               (unsigned)(ptr - (void *)dent));
 757 }
 758 
 759 static int get_leaf(struct gfs2_inode *dip, u64 leaf_no,
 760                     struct buffer_head **bhp)
 761 {
 762         int error;
 763 
 764         error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, 0, bhp);
 765         if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) {
 766                 /* pr_info("block num=%llu\n", leaf_no); */
 767                 error = -EIO;
 768         }
 769 
 770         return error;
 771 }
 772 
 773 /**
 774  * get_leaf_nr - Get a leaf number associated with the index
 775  * @dip: The GFS2 inode
 776  * @index:
 777  * @leaf_out:
 778  *
 779  * Returns: 0 on success, error code otherwise
 780  */
 781 
 782 static int get_leaf_nr(struct gfs2_inode *dip, u32 index,
 783                        u64 *leaf_out)
 784 {
 785         __be64 *hash;
 786         int error;
 787 
 788         hash = gfs2_dir_get_hash_table(dip);
 789         error = PTR_ERR_OR_ZERO(hash);
 790 
 791         if (!error)
 792                 *leaf_out = be64_to_cpu(*(hash + index));
 793 
 794         return error;
 795 }
 796 
 797 static int get_first_leaf(struct gfs2_inode *dip, u32 index,
 798                           struct buffer_head **bh_out)
 799 {
 800         u64 leaf_no;
 801         int error;
 802 
 803         error = get_leaf_nr(dip, index, &leaf_no);
 804         if (!error)
 805                 error = get_leaf(dip, leaf_no, bh_out);
 806 
 807         return error;
 808 }
 809 
 810 static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
 811                                               const struct qstr *name,
 812                                               gfs2_dscan_t scan,
 813                                               struct buffer_head **pbh)
 814 {
 815         struct buffer_head *bh;
 816         struct gfs2_dirent *dent;
 817         struct gfs2_inode *ip = GFS2_I(inode);
 818         int error;
 819 
 820         if (ip->i_diskflags & GFS2_DIF_EXHASH) {
 821                 struct gfs2_leaf *leaf;
 822                 unsigned int hsize = BIT(ip->i_depth);
 823                 unsigned int index;
 824                 u64 ln;
 825                 if (hsize * sizeof(u64) != i_size_read(inode)) {
 826                         gfs2_consist_inode(ip);
 827                         return ERR_PTR(-EIO);
 828                 }
 829 
 830                 index = name->hash >> (32 - ip->i_depth);
 831                 error = get_first_leaf(ip, index, &bh);
 832                 if (error)
 833                         return ERR_PTR(error);
 834                 do {
 835                         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 836                                                 scan, name, NULL);
 837                         if (dent)
 838                                 goto got_dent;
 839                         leaf = (struct gfs2_leaf *)bh->b_data;
 840                         ln = be64_to_cpu(leaf->lf_next);
 841                         brelse(bh);
 842                         if (!ln)
 843                                 break;
 844 
 845                         error = get_leaf(ip, ln, &bh);
 846                 } while(!error);
 847 
 848                 return error ? ERR_PTR(error) : NULL;
 849         }
 850 
 851 
 852         error = gfs2_meta_inode_buffer(ip, &bh);
 853         if (error)
 854                 return ERR_PTR(error);
 855         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
 856 got_dent:
 857         if (IS_ERR_OR_NULL(dent)) {
 858                 brelse(bh);
 859                 bh = NULL;
 860         }
 861         *pbh = bh;
 862         return dent;
 863 }
 864 
 865 static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
 866 {
 867         struct gfs2_inode *ip = GFS2_I(inode);
 868         unsigned int n = 1;
 869         u64 bn;
 870         int error;
 871         struct buffer_head *bh;
 872         struct gfs2_leaf *leaf;
 873         struct gfs2_dirent *dent;
 874         struct timespec64 tv = current_time(inode);
 875 
 876         error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);
 877         if (error)
 878                 return NULL;
 879         bh = gfs2_meta_new(ip->i_gl, bn);
 880         if (!bh)
 881                 return NULL;
 882 
 883         gfs2_trans_remove_revoke(GFS2_SB(inode), bn, 1);
 884         gfs2_trans_add_meta(ip->i_gl, bh);
 885         gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF);
 886         leaf = (struct gfs2_leaf *)bh->b_data;
 887         leaf->lf_depth = cpu_to_be16(depth);
 888         leaf->lf_entries = 0;
 889         leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
 890         leaf->lf_next = 0;
 891         leaf->lf_inode = cpu_to_be64(ip->i_no_addr);
 892         leaf->lf_dist = cpu_to_be32(1);
 893         leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
 894         leaf->lf_sec = cpu_to_be64(tv.tv_sec);
 895         memset(leaf->lf_reserved2, 0, sizeof(leaf->lf_reserved2));
 896         dent = (struct gfs2_dirent *)(leaf+1);
 897         gfs2_qstr2dirent(&empty_name, bh->b_size - sizeof(struct gfs2_leaf), dent);
 898         *pbh = bh;
 899         return leaf;
 900 }
 901 
 902 /**
 903  * dir_make_exhash - Convert a stuffed directory into an ExHash directory
 904  * @dip: The GFS2 inode
 905  *
 906  * Returns: 0 on success, error code otherwise
 907  */
 908 
 909 static int dir_make_exhash(struct inode *inode)
 910 {
 911         struct gfs2_inode *dip = GFS2_I(inode);
 912         struct gfs2_sbd *sdp = GFS2_SB(inode);
 913         struct gfs2_dirent *dent;
 914         struct qstr args;
 915         struct buffer_head *bh, *dibh;
 916         struct gfs2_leaf *leaf;
 917         int y;
 918         u32 x;
 919         __be64 *lp;
 920         u64 bn;
 921         int error;
 922 
 923         error = gfs2_meta_inode_buffer(dip, &dibh);
 924         if (error)
 925                 return error;
 926 
 927         /*  Turn over a new leaf  */
 928 
 929         leaf = new_leaf(inode, &bh, 0);
 930         if (!leaf)
 931                 return -ENOSPC;
 932         bn = bh->b_blocknr;
 933 
 934         gfs2_assert(sdp, dip->i_entries < BIT(16));
 935         leaf->lf_entries = cpu_to_be16(dip->i_entries);
 936 
 937         /*  Copy dirents  */
 938 
 939         gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
 940                              sizeof(struct gfs2_dinode));
 941 
 942         /*  Find last entry  */
 943 
 944         x = 0;
 945         args.len = bh->b_size - sizeof(struct gfs2_dinode) +
 946                    sizeof(struct gfs2_leaf);
 947         args.name = bh->b_data;
 948         dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size,
 949                                 gfs2_dirent_last, &args, NULL);
 950         if (!dent) {
 951                 brelse(bh);
 952                 brelse(dibh);
 953                 return -EIO;
 954         }
 955         if (IS_ERR(dent)) {
 956                 brelse(bh);
 957                 brelse(dibh);
 958                 return PTR_ERR(dent);
 959         }
 960 
 961         /*  Adjust the last dirent's record length
 962            (Remember that dent still points to the last entry.)  */
 963 
 964         dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
 965                 sizeof(struct gfs2_dinode) -
 966                 sizeof(struct gfs2_leaf));
 967 
 968         brelse(bh);
 969 
 970         /*  We're done with the new leaf block, now setup the new
 971             hash table.  */
 972 
 973         gfs2_trans_add_meta(dip->i_gl, dibh);
 974         gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
 975 
 976         lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
 977 
 978         for (x = sdp->sd_hash_ptrs; x--; lp++)
 979                 *lp = cpu_to_be64(bn);
 980 
 981         i_size_write(inode, sdp->sd_sb.sb_bsize / 2);
 982         gfs2_add_inode_blocks(&dip->i_inode, 1);
 983         dip->i_diskflags |= GFS2_DIF_EXHASH;
 984 
 985         for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
 986         dip->i_depth = y;
 987 
 988         gfs2_dinode_out(dip, dibh->b_data);
 989 
 990         brelse(dibh);
 991 
 992         return 0;
 993 }
 994 
 995 /**
 996  * dir_split_leaf - Split a leaf block into two
 997  * @dip: The GFS2 inode
 998  * @index:
 999  * @leaf_no:
1000  *
1001  * Returns: 0 on success, error code on failure
1002  */
1003 
1004 static int dir_split_leaf(struct inode *inode, const struct qstr *name)
1005 {
1006         struct gfs2_inode *dip = GFS2_I(inode);
1007         struct buffer_head *nbh, *obh, *dibh;
1008         struct gfs2_leaf *nleaf, *oleaf;
1009         struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new;
1010         u32 start, len, half_len, divider;
1011         u64 bn, leaf_no;
1012         __be64 *lp;
1013         u32 index;
1014         int x;
1015         int error;
1016 
1017         index = name->hash >> (32 - dip->i_depth);
1018         error = get_leaf_nr(dip, index, &leaf_no);
1019         if (error)
1020                 return error;
1021 
1022         /*  Get the old leaf block  */
1023         error = get_leaf(dip, leaf_no, &obh);
1024         if (error)
1025                 return error;
1026 
1027         oleaf = (struct gfs2_leaf *)obh->b_data;
1028         if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
1029                 brelse(obh);
1030                 return 1; /* can't split */
1031         }
1032 
1033         gfs2_trans_add_meta(dip->i_gl, obh);
1034 
1035         nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
1036         if (!nleaf) {
1037                 brelse(obh);
1038                 return -ENOSPC;
1039         }
1040         bn = nbh->b_blocknr;
1041 
1042         /*  Compute the start and len of leaf pointers in the hash table.  */
1043         len = BIT(dip->i_depth - be16_to_cpu(oleaf->lf_depth));
1044         half_len = len >> 1;
1045         if (!half_len) {
1046                 fs_warn(GFS2_SB(inode), "i_depth %u lf_depth %u index %u\n",
1047                         dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
1048                 gfs2_consist_inode(dip);
1049                 error = -EIO;
1050                 goto fail_brelse;
1051         }
1052 
1053         start = (index & ~(len - 1));
1054 
1055         /* Change the pointers.
1056            Don't bother distinguishing stuffed from non-stuffed.
1057            This code is complicated enough already. */
1058         lp = kmalloc_array(half_len, sizeof(__be64), GFP_NOFS);
1059         if (!lp) {
1060                 error = -ENOMEM;
1061                 goto fail_brelse;
1062         }
1063 
1064         /*  Change the pointers  */
1065         for (x = 0; x < half_len; x++)
1066                 lp[x] = cpu_to_be64(bn);
1067 
1068         gfs2_dir_hash_inval(dip);
1069 
1070         error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64),
1071                                     half_len * sizeof(u64));
1072         if (error != half_len * sizeof(u64)) {
1073                 if (error >= 0)
1074                         error = -EIO;
1075                 goto fail_lpfree;
1076         }
1077 
1078         kfree(lp);
1079 
1080         /*  Compute the divider  */
1081         divider = (start + half_len) << (32 - dip->i_depth);
1082 
1083         /*  Copy the entries  */
1084         dent = (struct gfs2_dirent *)(obh->b_data + sizeof(struct gfs2_leaf));
1085 
1086         do {
1087                 next = dent;
1088                 if (dirent_next(dip, obh, &next))
1089                         next = NULL;
1090 
1091                 if (!gfs2_dirent_sentinel(dent) &&
1092                     be32_to_cpu(dent->de_hash) < divider) {
1093                         struct qstr str;
1094                         void *ptr = ((char *)dent - obh->b_data) + nbh->b_data;
1095                         str.name = (char*)(dent+1);
1096                         str.len = be16_to_cpu(dent->de_name_len);
1097                         str.hash = be32_to_cpu(dent->de_hash);
1098                         new = gfs2_dirent_split_alloc(inode, nbh, &str, ptr);
1099                         if (IS_ERR(new)) {
1100                                 error = PTR_ERR(new);
1101                                 break;
1102                         }
1103 
1104                         new->de_inum = dent->de_inum; /* No endian worries */
1105                         new->de_type = dent->de_type; /* No endian worries */
1106                         be16_add_cpu(&nleaf->lf_entries, 1);
1107 
1108                         dirent_del(dip, obh, prev, dent);
1109 
1110                         if (!oleaf->lf_entries)
1111                                 gfs2_consist_inode(dip);
1112                         be16_add_cpu(&oleaf->lf_entries, -1);
1113 
1114                         if (!prev)
1115                                 prev = dent;
1116                 } else {
1117                         prev = dent;
1118                 }
1119                 dent = next;
1120         } while (dent);
1121 
1122         oleaf->lf_depth = nleaf->lf_depth;
1123 
1124         error = gfs2_meta_inode_buffer(dip, &dibh);
1125         if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) {
1126                 gfs2_trans_add_meta(dip->i_gl, dibh);
1127                 gfs2_add_inode_blocks(&dip->i_inode, 1);
1128                 gfs2_dinode_out(dip, dibh->b_data);
1129                 brelse(dibh);
1130         }
1131 
1132         brelse(obh);
1133         brelse(nbh);
1134 
1135         return error;
1136 
1137 fail_lpfree:
1138         kfree(lp);
1139 
1140 fail_brelse:
1141         brelse(obh);
1142         brelse(nbh);
1143         return error;
1144 }
1145 
1146 /**
1147  * dir_double_exhash - Double size of ExHash table
1148  * @dip: The GFS2 dinode
1149  *
1150  * Returns: 0 on success, error code on failure
1151  */
1152 
1153 static int dir_double_exhash(struct gfs2_inode *dip)
1154 {
1155         struct buffer_head *dibh;
1156         u32 hsize;
1157         u32 hsize_bytes;
1158         __be64 *hc;
1159         __be64 *hc2, *h;
1160         int x;
1161         int error = 0;
1162 
1163         hsize = BIT(dip->i_depth);
1164         hsize_bytes = hsize * sizeof(__be64);
1165 
1166         hc = gfs2_dir_get_hash_table(dip);
1167         if (IS_ERR(hc))
1168                 return PTR_ERR(hc);
1169 
1170         hc2 = kmalloc_array(hsize_bytes, 2, GFP_NOFS | __GFP_NOWARN);
1171         if (hc2 == NULL)
1172                 hc2 = __vmalloc(hsize_bytes * 2, GFP_NOFS, PAGE_KERNEL);
1173 
1174         if (!hc2)
1175                 return -ENOMEM;
1176 
1177         h = hc2;
1178         error = gfs2_meta_inode_buffer(dip, &dibh);
1179         if (error)
1180                 goto out_kfree;
1181 
1182         for (x = 0; x < hsize; x++) {
1183                 *h++ = *hc;
1184                 *h++ = *hc;
1185                 hc++;
1186         }
1187 
1188         error = gfs2_dir_write_data(dip, (char *)hc2, 0, hsize_bytes * 2);
1189         if (error != (hsize_bytes * 2))
1190                 goto fail;
1191 
1192         gfs2_dir_hash_inval(dip);
1193         dip->i_hash_cache = hc2;
1194         dip->i_depth++;
1195         gfs2_dinode_out(dip, dibh->b_data);
1196         brelse(dibh);
1197         return 0;
1198 
1199 fail:
1200         /* Replace original hash table & size */
1201         gfs2_dir_write_data(dip, (char *)hc, 0, hsize_bytes);
1202         i_size_write(&dip->i_inode, hsize_bytes);
1203         gfs2_dinode_out(dip, dibh->b_data);
1204         brelse(dibh);
1205 out_kfree:
1206         kvfree(hc2);
1207         return error;
1208 }
1209 
1210 /**
1211  * compare_dents - compare directory entries by hash value
1212  * @a: first dent
1213  * @b: second dent
1214  *
1215  * When comparing the hash entries of @a to @b:
1216  *   gt: returns 1
1217  *   lt: returns -1
1218  *   eq: returns 0
1219  */
1220 
1221 static int compare_dents(const void *a, const void *b)
1222 {
1223         const struct gfs2_dirent *dent_a, *dent_b;
1224         u32 hash_a, hash_b;
1225         int ret = 0;
1226 
1227         dent_a = *(const struct gfs2_dirent **)a;
1228         hash_a = dent_a->de_cookie;
1229 
1230         dent_b = *(const struct gfs2_dirent **)b;
1231         hash_b = dent_b->de_cookie;
1232 
1233         if (hash_a > hash_b)
1234                 ret = 1;
1235         else if (hash_a < hash_b)
1236                 ret = -1;
1237         else {
1238                 unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
1239                 unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
1240 
1241                 if (len_a > len_b)
1242                         ret = 1;
1243                 else if (len_a < len_b)
1244                         ret = -1;
1245                 else
1246                         ret = memcmp(dent_a + 1, dent_b + 1, len_a);
1247         }
1248 
1249         return ret;
1250 }
1251 
1252 /**
1253  * do_filldir_main - read out directory entries
1254  * @dip: The GFS2 inode
1255  * @ctx: what to feed the entries to
1256  * @darr: an array of struct gfs2_dirent pointers to read
1257  * @entries: the number of entries in darr
1258  * @copied: pointer to int that's non-zero if a entry has been copied out
1259  *
1260  * Jump through some hoops to make sure that if there are hash collsions,
1261  * they are read out at the beginning of a buffer.  We want to minimize
1262  * the possibility that they will fall into different readdir buffers or
1263  * that someone will want to seek to that location.
1264  *
1265  * Returns: errno, >0 if the actor tells you to stop
1266  */
1267 
1268 static int do_filldir_main(struct gfs2_inode *dip, struct dir_context *ctx,
1269                            struct gfs2_dirent **darr, u32 entries,
1270                            u32 sort_start, int *copied)
1271 {
1272         const struct gfs2_dirent *dent, *dent_next;
1273         u64 off, off_next;
1274         unsigned int x, y;
1275         int run = 0;
1276 
1277         if (sort_start < entries)
1278                 sort(&darr[sort_start], entries - sort_start,
1279                      sizeof(struct gfs2_dirent *), compare_dents, NULL);
1280 
1281         dent_next = darr[0];
1282         off_next = dent_next->de_cookie;
1283 
1284         for (x = 0, y = 1; x < entries; x++, y++) {
1285                 dent = dent_next;
1286                 off = off_next;
1287 
1288                 if (y < entries) {
1289                         dent_next = darr[y];
1290                         off_next = dent_next->de_cookie;
1291 
1292                         if (off < ctx->pos)
1293                                 continue;
1294                         ctx->pos = off;
1295 
1296                         if (off_next == off) {
1297                                 if (*copied && !run)
1298                                         return 1;
1299                                 run = 1;
1300                         } else
1301                                 run = 0;
1302                 } else {
1303                         if (off < ctx->pos)
1304                                 continue;
1305                         ctx->pos = off;
1306                 }
1307 
1308                 if (!dir_emit(ctx, (const char *)(dent + 1),
1309                                 be16_to_cpu(dent->de_name_len),
1310                                 be64_to_cpu(dent->de_inum.no_addr),
1311                                 be16_to_cpu(dent->de_type)))
1312                         return 1;
1313 
1314                 *copied = 1;
1315         }
1316 
1317         /* Increment the ctx->pos by one, so the next time we come into the
1318            do_filldir fxn, we get the next entry instead of the last one in the
1319            current leaf */
1320 
1321         ctx->pos++;
1322 
1323         return 0;
1324 }
1325 
1326 static void *gfs2_alloc_sort_buffer(unsigned size)
1327 {
1328         void *ptr = NULL;
1329 
1330         if (size < KMALLOC_MAX_SIZE)
1331                 ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN);
1332         if (!ptr)
1333                 ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL);
1334         return ptr;
1335 }
1336 
1337 
1338 static int gfs2_set_cookies(struct gfs2_sbd *sdp, struct buffer_head *bh,
1339                             unsigned leaf_nr, struct gfs2_dirent **darr,
1340                             unsigned entries)
1341 {
1342         int sort_id = -1;
1343         int i;
1344         
1345         for (i = 0; i < entries; i++) {
1346                 unsigned offset;
1347 
1348                 darr[i]->de_cookie = be32_to_cpu(darr[i]->de_hash);
1349                 darr[i]->de_cookie = gfs2_disk_hash2offset(darr[i]->de_cookie);
1350 
1351                 if (!sdp->sd_args.ar_loccookie)
1352                         continue;
1353                 offset = (char *)(darr[i]) -
1354                         (bh->b_data + gfs2_dirent_offset(sdp, bh->b_data));
1355                 offset /= GFS2_MIN_DIRENT_SIZE;
1356                 offset += leaf_nr * sdp->sd_max_dents_per_leaf;
1357                 if (offset >= GFS2_USE_HASH_FLAG ||
1358                     leaf_nr >= GFS2_USE_HASH_FLAG) {
1359                         darr[i]->de_cookie |= GFS2_USE_HASH_FLAG;
1360                         if (sort_id < 0)
1361                                 sort_id = i;
1362                         continue;
1363                 }
1364                 darr[i]->de_cookie &= GFS2_HASH_INDEX_MASK;
1365                 darr[i]->de_cookie |= offset;
1366         }
1367         return sort_id;
1368 }       
1369 
1370 
1371 static int gfs2_dir_read_leaf(struct inode *inode, struct dir_context *ctx,
1372                               int *copied, unsigned *depth,
1373                               u64 leaf_no)
1374 {
1375         struct gfs2_inode *ip = GFS2_I(inode);
1376         struct gfs2_sbd *sdp = GFS2_SB(inode);
1377         struct buffer_head *bh;
1378         struct gfs2_leaf *lf;
1379         unsigned entries = 0, entries2 = 0;
1380         unsigned leaves = 0, leaf = 0, offset, sort_offset;
1381         struct gfs2_dirent **darr, *dent;
1382         struct dirent_gather g;
1383         struct buffer_head **larr;
1384         int error, i, need_sort = 0, sort_id;
1385         u64 lfn = leaf_no;
1386 
1387         do {
1388                 error = get_leaf(ip, lfn, &bh);
1389                 if (error)
1390                         goto out;
1391                 lf = (struct gfs2_leaf *)bh->b_data;
1392                 if (leaves == 0)
1393                         *depth = be16_to_cpu(lf->lf_depth);
1394                 entries += be16_to_cpu(lf->lf_entries);
1395                 leaves++;
1396                 lfn = be64_to_cpu(lf->lf_next);
1397                 brelse(bh);
1398         } while(lfn);
1399 
1400         if (*depth < GFS2_DIR_MAX_DEPTH || !sdp->sd_args.ar_loccookie) {
1401                 need_sort = 1;
1402                 sort_offset = 0;
1403         }
1404 
1405         if (!entries)
1406                 return 0;
1407 
1408         error = -ENOMEM;
1409         /*
1410          * The extra 99 entries are not normally used, but are a buffer
1411          * zone in case the number of entries in the leaf is corrupt.
1412          * 99 is the maximum number of entries that can fit in a single
1413          * leaf block.
1414          */
1415         larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *));
1416         if (!larr)
1417                 goto out;
1418         darr = (struct gfs2_dirent **)(larr + leaves);
1419         g.pdent = (const struct gfs2_dirent **)darr;
1420         g.offset = 0;
1421         lfn = leaf_no;
1422 
1423         do {
1424                 error = get_leaf(ip, lfn, &bh);
1425                 if (error)
1426                         goto out_free;
1427                 lf = (struct gfs2_leaf *)bh->b_data;
1428                 lfn = be64_to_cpu(lf->lf_next);
1429                 if (lf->lf_entries) {
1430                         offset = g.offset;
1431                         entries2 += be16_to_cpu(lf->lf_entries);
1432                         dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
1433                                                 gfs2_dirent_gather, NULL, &g);
1434                         error = PTR_ERR(dent);
1435                         if (IS_ERR(dent))
1436                                 goto out_free;
1437                         if (entries2 != g.offset) {
1438                                 fs_warn(sdp, "Number of entries corrupt in dir "
1439                                                 "leaf %llu, entries2 (%u) != "
1440                                                 "g.offset (%u)\n",
1441                                         (unsigned long long)bh->b_blocknr,
1442                                         entries2, g.offset);
1443                                 gfs2_consist_inode(ip);
1444                                 error = -EIO;
1445                                 goto out_free;
1446                         }
1447                         error = 0;
1448                         sort_id = gfs2_set_cookies(sdp, bh, leaf, &darr[offset],
1449                                                    be16_to_cpu(lf->lf_entries));
1450                         if (!need_sort && sort_id >= 0) {
1451                                 need_sort = 1;
1452                                 sort_offset = offset + sort_id;
1453                         }
1454                         larr[leaf++] = bh;
1455                 } else {
1456                         larr[leaf++] = NULL;
1457                         brelse(bh);
1458                 }
1459         } while(lfn);
1460 
1461         BUG_ON(entries2 != entries);
1462         error = do_filldir_main(ip, ctx, darr, entries, need_sort ?
1463                                 sort_offset : entries, copied);
1464 out_free:
1465         for(i = 0; i < leaf; i++)
1466                 brelse(larr[i]);
1467         kvfree(larr);
1468 out:
1469         return error;
1470 }
1471 
1472 /**
1473  * gfs2_dir_readahead - Issue read-ahead requests for leaf blocks.
1474  *
1475  * Note: we can't calculate each index like dir_e_read can because we don't
1476  * have the leaf, and therefore we don't have the depth, and therefore we
1477  * don't have the length. So we have to just read enough ahead to make up
1478  * for the loss of information.
1479  */
1480 static void gfs2_dir_readahead(struct inode *inode, unsigned hsize, u32 index,
1481                                struct file_ra_state *f_ra)
1482 {
1483         struct gfs2_inode *ip = GFS2_I(inode);
1484         struct gfs2_glock *gl = ip->i_gl;
1485         struct buffer_head *bh;
1486         u64 blocknr = 0, last;
1487         unsigned count;
1488 
1489         /* First check if we've already read-ahead for the whole range. */
1490         if (index + MAX_RA_BLOCKS < f_ra->start)
1491                 return;
1492 
1493         f_ra->start = max((pgoff_t)index, f_ra->start);
1494         for (count = 0; count < MAX_RA_BLOCKS; count++) {
1495                 if (f_ra->start >= hsize) /* if exceeded the hash table */
1496                         break;
1497 
1498                 last = blocknr;
1499                 blocknr = be64_to_cpu(ip->i_hash_cache[f_ra->start]);
1500                 f_ra->start++;
1501                 if (blocknr == last)
1502                         continue;
1503 
1504                 bh = gfs2_getbuf(gl, blocknr, 1);
1505                 if (trylock_buffer(bh)) {
1506                         if (buffer_uptodate(bh)) {
1507                                 unlock_buffer(bh);
1508                                 brelse(bh);
1509                                 continue;
1510                         }
1511                         bh->b_end_io = end_buffer_read_sync;
1512                         submit_bh(REQ_OP_READ,
1513                                   REQ_RAHEAD | REQ_META | REQ_PRIO,
1514                                   bh);
1515                         continue;
1516                 }
1517                 brelse(bh);
1518         }
1519 }
1520 
1521 /**
1522  * dir_e_read - Reads the entries from a directory into a filldir buffer
1523  * @dip: dinode pointer
1524  * @ctx: actor to feed the entries to
1525  *
1526  * Returns: errno
1527  */
1528 
1529 static int dir_e_read(struct inode *inode, struct dir_context *ctx,
1530                       struct file_ra_state *f_ra)
1531 {
1532         struct gfs2_inode *dip = GFS2_I(inode);
1533         u32 hsize, len = 0;
1534         u32 hash, index;
1535         __be64 *lp;
1536         int copied = 0;
1537         int error = 0;
1538         unsigned depth = 0;
1539 
1540         hsize = BIT(dip->i_depth);
1541         hash = gfs2_dir_offset2hash(ctx->pos);
1542         index = hash >> (32 - dip->i_depth);
1543 
1544         if (dip->i_hash_cache == NULL)
1545                 f_ra->start = 0;
1546         lp = gfs2_dir_get_hash_table(dip);
1547         if (IS_ERR(lp))
1548                 return PTR_ERR(lp);
1549 
1550         gfs2_dir_readahead(inode, hsize, index, f_ra);
1551 
1552         while (index < hsize) {
1553                 error = gfs2_dir_read_leaf(inode, ctx,
1554                                            &copied, &depth,
1555                                            be64_to_cpu(lp[index]));
1556                 if (error)
1557                         break;
1558 
1559                 len = BIT(dip->i_depth - depth);
1560                 index = (index & ~(len - 1)) + len;
1561         }
1562 
1563         if (error > 0)
1564                 error = 0;
1565         return error;
1566 }
1567 
1568 int gfs2_dir_read(struct inode *inode, struct dir_context *ctx,
1569                   struct file_ra_state *f_ra)
1570 {
1571         struct gfs2_inode *dip = GFS2_I(inode);
1572         struct gfs2_sbd *sdp = GFS2_SB(inode);
1573         struct dirent_gather g;
1574         struct gfs2_dirent **darr, *dent;
1575         struct buffer_head *dibh;
1576         int copied = 0;
1577         int error;
1578 
1579         if (!dip->i_entries)
1580                 return 0;
1581 
1582         if (dip->i_diskflags & GFS2_DIF_EXHASH)
1583                 return dir_e_read(inode, ctx, f_ra);
1584 
1585         if (!gfs2_is_stuffed(dip)) {
1586                 gfs2_consist_inode(dip);
1587                 return -EIO;
1588         }
1589 
1590         error = gfs2_meta_inode_buffer(dip, &dibh);
1591         if (error)
1592                 return error;
1593 
1594         error = -ENOMEM;
1595         /* 96 is max number of dirents which can be stuffed into an inode */
1596         darr = kmalloc_array(96, sizeof(struct gfs2_dirent *), GFP_NOFS);
1597         if (darr) {
1598                 g.pdent = (const struct gfs2_dirent **)darr;
1599                 g.offset = 0;
1600                 dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size,
1601                                         gfs2_dirent_gather, NULL, &g);
1602                 if (IS_ERR(dent)) {
1603                         error = PTR_ERR(dent);
1604                         goto out;
1605                 }
1606                 if (dip->i_entries != g.offset) {
1607                         fs_warn(sdp, "Number of entries corrupt in dir %llu, "
1608                                 "ip->i_entries (%u) != g.offset (%u)\n",
1609                                 (unsigned long long)dip->i_no_addr,
1610                                 dip->i_entries,
1611                                 g.offset);
1612                         gfs2_consist_inode(dip);
1613                         error = -EIO;
1614                         goto out;
1615                 }
1616                 gfs2_set_cookies(sdp, dibh, 0, darr, dip->i_entries);
1617                 error = do_filldir_main(dip, ctx, darr,
1618                                         dip->i_entries, 0, &copied);
1619 out:
1620                 kfree(darr);
1621         }
1622 
1623         if (error > 0)
1624                 error = 0;
1625 
1626         brelse(dibh);
1627 
1628         return error;
1629 }
1630 
1631 /**
1632  * gfs2_dir_search - Search a directory
1633  * @dip: The GFS2 dir inode
1634  * @name: The name we are looking up
1635  * @fail_on_exist: Fail if the name exists rather than looking it up
1636  *
1637  * This routine searches a directory for a file or another directory.
1638  * Assumes a glock is held on dip.
1639  *
1640  * Returns: errno
1641  */
1642 
1643 struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name,
1644                               bool fail_on_exist)
1645 {
1646         struct buffer_head *bh;
1647         struct gfs2_dirent *dent;
1648         u64 addr, formal_ino;
1649         u16 dtype;
1650 
1651         dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1652         if (dent) {
1653                 struct inode *inode;
1654                 u16 rahead;
1655 
1656                 if (IS_ERR(dent))
1657                         return ERR_CAST(dent);
1658                 dtype = be16_to_cpu(dent->de_type);
1659                 rahead = be16_to_cpu(dent->de_rahead);
1660                 addr = be64_to_cpu(dent->de_inum.no_addr);
1661                 formal_ino = be64_to_cpu(dent->de_inum.no_formal_ino);
1662                 brelse(bh);
1663                 if (fail_on_exist)
1664                         return ERR_PTR(-EEXIST);
1665                 inode = gfs2_inode_lookup(dir->i_sb, dtype, addr, formal_ino,
1666                                           GFS2_BLKST_FREE /* ignore */);
1667                 if (!IS_ERR(inode))
1668                         GFS2_I(inode)->i_rahead = rahead;
1669                 return inode;
1670         }
1671         return ERR_PTR(-ENOENT);
1672 }
1673 
1674 int gfs2_dir_check(struct inode *dir, const struct qstr *name,
1675                    const struct gfs2_inode *ip)
1676 {
1677         struct buffer_head *bh;
1678         struct gfs2_dirent *dent;
1679         int ret = -ENOENT;
1680 
1681         dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1682         if (dent) {
1683                 if (IS_ERR(dent))
1684                         return PTR_ERR(dent);
1685                 if (ip) {
1686                         if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
1687                                 goto out;
1688                         if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
1689                             ip->i_no_formal_ino)
1690                                 goto out;
1691                         if (unlikely(IF2DT(ip->i_inode.i_mode) !=
1692                             be16_to_cpu(dent->de_type))) {
1693                                 gfs2_consist_inode(GFS2_I(dir));
1694                                 ret = -EIO;
1695                                 goto out;
1696                         }
1697                 }
1698                 ret = 0;
1699 out:
1700                 brelse(bh);
1701         }
1702         return ret;
1703 }
1704 
1705 /**
1706  * dir_new_leaf - Add a new leaf onto hash chain
1707  * @inode: The directory
1708  * @name: The name we are adding
1709  *
1710  * This adds a new dir leaf onto an existing leaf when there is not
1711  * enough space to add a new dir entry. This is a last resort after
1712  * we've expanded the hash table to max size and also split existing
1713  * leaf blocks, so it will only occur for very large directories.
1714  *
1715  * The dist parameter is set to 1 for leaf blocks directly attached
1716  * to the hash table, 2 for one layer of indirection, 3 for two layers
1717  * etc. We are thus able to tell the difference between an old leaf
1718  * with dist set to zero (i.e. "don't know") and a new one where we
1719  * set this information for debug/fsck purposes.
1720  *
1721  * Returns: 0 on success, or -ve on error
1722  */
1723 
1724 static int dir_new_leaf(struct inode *inode, const struct qstr *name)
1725 {
1726         struct buffer_head *bh, *obh;
1727         struct gfs2_inode *ip = GFS2_I(inode);
1728         struct gfs2_leaf *leaf, *oleaf;
1729         u32 dist = 1;
1730         int error;
1731         u32 index;
1732         u64 bn;
1733 
1734         index = name->hash >> (32 - ip->i_depth);
1735         error = get_first_leaf(ip, index, &obh);
1736         if (error)
1737                 return error;
1738         do {
1739                 dist++;
1740                 oleaf = (struct gfs2_leaf *)obh->b_data;
1741                 bn = be64_to_cpu(oleaf->lf_next);
1742                 if (!bn)
1743                         break;
1744                 brelse(obh);
1745                 error = get_leaf(ip, bn, &obh);
1746                 if (error)
1747                         return error;
1748         } while(1);
1749 
1750         gfs2_trans_add_meta(ip->i_gl, obh);
1751 
1752         leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
1753         if (!leaf) {
1754                 brelse(obh);
1755                 return -ENOSPC;
1756         }
1757         leaf->lf_dist = cpu_to_be32(dist);
1758         oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
1759         brelse(bh);
1760         brelse(obh);
1761 
1762         error = gfs2_meta_inode_buffer(ip, &bh);
1763         if (error)
1764                 return error;
1765         gfs2_trans_add_meta(ip->i_gl, bh);
1766         gfs2_add_inode_blocks(&ip->i_inode, 1);
1767         gfs2_dinode_out(ip, bh->b_data);
1768         brelse(bh);
1769         return 0;
1770 }
1771 
1772 static u16 gfs2_inode_ra_len(const struct gfs2_inode *ip)
1773 {
1774         u64 where = ip->i_no_addr + 1;
1775         if (ip->i_eattr == where)
1776                 return 1;
1777         return 0;
1778 }
1779 
1780 /**
1781  * gfs2_dir_add - Add new filename into directory
1782  * @inode: The directory inode
1783  * @name: The new name
1784  * @nip: The GFS2 inode to be linked in to the directory
1785  * @da: The directory addition info
1786  *
1787  * If the call to gfs2_diradd_alloc_required resulted in there being
1788  * no need to allocate any new directory blocks, then it will contain
1789  * a pointer to the directory entry and the bh in which it resides. We
1790  * can use that without having to repeat the search. If there was no
1791  * free space, then we must now create more space.
1792  *
1793  * Returns: 0 on success, error code on failure
1794  */
1795 
1796 int gfs2_dir_add(struct inode *inode, const struct qstr *name,
1797                  const struct gfs2_inode *nip, struct gfs2_diradd *da)
1798 {
1799         struct gfs2_inode *ip = GFS2_I(inode);
1800         struct buffer_head *bh = da->bh;
1801         struct gfs2_dirent *dent = da->dent;
1802         struct timespec64 tv;
1803         struct gfs2_leaf *leaf;
1804         int error;
1805 
1806         while(1) {
1807                 if (da->bh == NULL) {
1808                         dent = gfs2_dirent_search(inode, name,
1809                                                   gfs2_dirent_find_space, &bh);
1810                 }
1811                 if (dent) {
1812                         if (IS_ERR(dent))
1813                                 return PTR_ERR(dent);
1814                         dent = gfs2_init_dirent(inode, dent, name, bh);
1815                         gfs2_inum_out(nip, dent);
1816                         dent->de_type = cpu_to_be16(IF2DT(nip->i_inode.i_mode));
1817                         dent->de_rahead = cpu_to_be16(gfs2_inode_ra_len(nip));
1818                         tv = current_time(&ip->i_inode);
1819                         if (ip->i_diskflags & GFS2_DIF_EXHASH) {
1820                                 leaf = (struct gfs2_leaf *)bh->b_data;
1821                                 be16_add_cpu(&leaf->lf_entries, 1);
1822                                 leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
1823                                 leaf->lf_sec = cpu_to_be64(tv.tv_sec);
1824                         }
1825                         da->dent = NULL;
1826                         da->bh = NULL;
1827                         brelse(bh);
1828                         ip->i_entries++;
1829                         ip->i_inode.i_mtime = ip->i_inode.i_ctime = tv;
1830                         if (S_ISDIR(nip->i_inode.i_mode))
1831                                 inc_nlink(&ip->i_inode);
1832                         mark_inode_dirty(inode);
1833                         error = 0;
1834                         break;
1835                 }
1836                 if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) {
1837                         error = dir_make_exhash(inode);
1838                         if (error)
1839                                 break;
1840                         continue;
1841                 }
1842                 error = dir_split_leaf(inode, name);
1843                 if (error == 0)
1844                         continue;
1845                 if (error < 0)
1846                         break;
1847                 if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
1848                         error = dir_double_exhash(ip);
1849                         if (error)
1850                                 break;
1851                         error = dir_split_leaf(inode, name);
1852                         if (error < 0)
1853                                 break;
1854                         if (error == 0)
1855                                 continue;
1856                 }
1857                 error = dir_new_leaf(inode, name);
1858                 if (!error)
1859                         continue;
1860                 error = -ENOSPC;
1861                 break;
1862         }
1863         return error;
1864 }
1865 
1866 
1867 /**
1868  * gfs2_dir_del - Delete a directory entry
1869  * @dip: The GFS2 inode
1870  * @filename: The filename
1871  *
1872  * Returns: 0 on success, error code on failure
1873  */
1874 
1875 int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry)
1876 {
1877         const struct qstr *name = &dentry->d_name;
1878         struct gfs2_dirent *dent, *prev = NULL;
1879         struct buffer_head *bh;
1880         struct timespec64 tv = current_time(&dip->i_inode);
1881 
1882         /* Returns _either_ the entry (if its first in block) or the
1883            previous entry otherwise */
1884         dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh);
1885         if (!dent) {
1886                 gfs2_consist_inode(dip);
1887                 return -EIO;
1888         }
1889         if (IS_ERR(dent)) {
1890                 gfs2_consist_inode(dip);
1891                 return PTR_ERR(dent);
1892         }
1893         /* If not first in block, adjust pointers accordingly */
1894         if (gfs2_dirent_find(dent, name, NULL) == 0) {
1895                 prev = dent;
1896                 dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
1897         }
1898 
1899         dirent_del(dip, bh, prev, dent);
1900         if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1901                 struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
1902                 u16 entries = be16_to_cpu(leaf->lf_entries);
1903                 if (!entries)
1904                         gfs2_consist_inode(dip);
1905                 leaf->lf_entries = cpu_to_be16(--entries);
1906                 leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
1907                 leaf->lf_sec = cpu_to_be64(tv.tv_sec);
1908         }
1909         brelse(bh);
1910 
1911         if (!dip->i_entries)
1912                 gfs2_consist_inode(dip);
1913         dip->i_entries--;
1914         dip->i_inode.i_mtime = dip->i_inode.i_ctime = tv;
1915         if (d_is_dir(dentry))
1916                 drop_nlink(&dip->i_inode);
1917         mark_inode_dirty(&dip->i_inode);
1918 
1919         return 0;
1920 }
1921 
1922 /**
1923  * gfs2_dir_mvino - Change inode number of directory entry
1924  * @dip: The GFS2 inode
1925  * @filename:
1926  * @new_inode:
1927  *
1928  * This routine changes the inode number of a directory entry.  It's used
1929  * by rename to change ".." when a directory is moved.
1930  * Assumes a glock is held on dvp.
1931  *
1932  * Returns: errno
1933  */
1934 
1935 int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
1936                    const struct gfs2_inode *nip, unsigned int new_type)
1937 {
1938         struct buffer_head *bh;
1939         struct gfs2_dirent *dent;
1940 
1941         dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh);
1942         if (!dent) {
1943                 gfs2_consist_inode(dip);
1944                 return -EIO;
1945         }
1946         if (IS_ERR(dent))
1947                 return PTR_ERR(dent);
1948 
1949         gfs2_trans_add_meta(dip->i_gl, bh);
1950         gfs2_inum_out(nip, dent);
1951         dent->de_type = cpu_to_be16(new_type);
1952         brelse(bh);
1953 
1954         dip->i_inode.i_mtime = dip->i_inode.i_ctime = current_time(&dip->i_inode);
1955         mark_inode_dirty_sync(&dip->i_inode);
1956         return 0;
1957 }
1958 
1959 /**
1960  * leaf_dealloc - Deallocate a directory leaf
1961  * @dip: the directory
1962  * @index: the hash table offset in the directory
1963  * @len: the number of pointers to this leaf
1964  * @leaf_no: the leaf number
1965  * @leaf_bh: buffer_head for the starting leaf
1966  * last_dealloc: 1 if this is the final dealloc for the leaf, else 0
1967  *
1968  * Returns: errno
1969  */
1970 
1971 static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len,
1972                         u64 leaf_no, struct buffer_head *leaf_bh,
1973                         int last_dealloc)
1974 {
1975         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1976         struct gfs2_leaf *tmp_leaf;
1977         struct gfs2_rgrp_list rlist;
1978         struct buffer_head *bh, *dibh;
1979         u64 blk, nblk;
1980         unsigned int rg_blocks = 0, l_blocks = 0;
1981         char *ht;
1982         unsigned int x, size = len * sizeof(u64);
1983         int error;
1984 
1985         error = gfs2_rindex_update(sdp);
1986         if (error)
1987                 return error;
1988 
1989         memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
1990 
1991         ht = kzalloc(size, GFP_NOFS | __GFP_NOWARN);
1992         if (ht == NULL)
1993                 ht = __vmalloc(size, GFP_NOFS | __GFP_NOWARN | __GFP_ZERO,
1994                                PAGE_KERNEL);
1995         if (!ht)
1996                 return -ENOMEM;
1997 
1998         error = gfs2_quota_hold(dip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1999         if (error)
2000                 goto out;
2001 
2002         /*  Count the number of leaves  */
2003         bh = leaf_bh;
2004 
2005         for (blk = leaf_no; blk; blk = nblk) {
2006                 if (blk != leaf_no) {
2007                         error = get_leaf(dip, blk, &bh);
2008                         if (error)
2009                                 goto out_rlist;
2010                 }
2011                 tmp_leaf = (struct gfs2_leaf *)bh->b_data;
2012                 nblk = be64_to_cpu(tmp_leaf->lf_next);
2013                 if (blk != leaf_no)
2014                         brelse(bh);
2015 
2016                 gfs2_rlist_add(dip, &rlist, blk);
2017                 l_blocks++;
2018         }
2019 
2020         gfs2_rlist_alloc(&rlist);
2021 
2022         for (x = 0; x < rlist.rl_rgrps; x++) {
2023                 struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(rlist.rl_ghs[x].gh_gl);
2024 
2025                 rg_blocks += rgd->rd_length;
2026         }
2027 
2028         error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
2029         if (error)
2030                 goto out_rlist;
2031 
2032         error = gfs2_trans_begin(sdp,
2033                         rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
2034                         RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
2035         if (error)
2036                 goto out_rg_gunlock;
2037 
2038         bh = leaf_bh;
2039 
2040         for (blk = leaf_no; blk; blk = nblk) {
2041                 struct gfs2_rgrpd *rgd;
2042 
2043                 if (blk != leaf_no) {
2044                         error = get_leaf(dip, blk, &bh);
2045                         if (error)
2046                                 goto out_end_trans;
2047                 }
2048                 tmp_leaf = (struct gfs2_leaf *)bh->b_data;
2049                 nblk = be64_to_cpu(tmp_leaf->lf_next);
2050                 if (blk != leaf_no)
2051                         brelse(bh);
2052 
2053                 rgd = gfs2_blk2rgrpd(sdp, blk, true);
2054                 gfs2_free_meta(dip, rgd, blk, 1);
2055                 gfs2_add_inode_blocks(&dip->i_inode, -1);
2056         }
2057 
2058         error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size);
2059         if (error != size) {
2060                 if (error >= 0)
2061                         error = -EIO;
2062                 goto out_end_trans;
2063         }
2064 
2065         error = gfs2_meta_inode_buffer(dip, &dibh);
2066         if (error)
2067                 goto out_end_trans;
2068 
2069         gfs2_trans_add_meta(dip->i_gl, dibh);
2070         /* On the last dealloc, make this a regular file in case we crash.
2071            (We don't want to free these blocks a second time.)  */
2072         if (last_dealloc)
2073                 dip->i_inode.i_mode = S_IFREG;
2074         gfs2_dinode_out(dip, dibh->b_data);
2075         brelse(dibh);
2076 
2077 out_end_trans:
2078         gfs2_trans_end(sdp);
2079 out_rg_gunlock:
2080         gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
2081 out_rlist:
2082         gfs2_rlist_free(&rlist);
2083         gfs2_quota_unhold(dip);
2084 out:
2085         kvfree(ht);
2086         return error;
2087 }
2088 
2089 /**
2090  * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory
2091  * @dip: the directory
2092  *
2093  * Dealloc all on-disk directory leaves to FREEMETA state
2094  * Change on-disk inode type to "regular file"
2095  *
2096  * Returns: errno
2097  */
2098 
2099 int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip)
2100 {
2101         struct buffer_head *bh;
2102         struct gfs2_leaf *leaf;
2103         u32 hsize, len;
2104         u32 index = 0, next_index;
2105         __be64 *lp;
2106         u64 leaf_no;
2107         int error = 0, last;
2108 
2109         hsize = BIT(dip->i_depth);
2110 
2111         lp = gfs2_dir_get_hash_table(dip);
2112         if (IS_ERR(lp))
2113                 return PTR_ERR(lp);
2114 
2115         while (index < hsize) {
2116                 leaf_no = be64_to_cpu(lp[index]);
2117                 if (leaf_no) {
2118                         error = get_leaf(dip, leaf_no, &bh);
2119                         if (error)
2120                                 goto out;
2121                         leaf = (struct gfs2_leaf *)bh->b_data;
2122                         len = BIT(dip->i_depth - be16_to_cpu(leaf->lf_depth));
2123 
2124                         next_index = (index & ~(len - 1)) + len;
2125                         last = ((next_index >= hsize) ? 1 : 0);
2126                         error = leaf_dealloc(dip, index, len, leaf_no, bh,
2127                                              last);
2128                         brelse(bh);
2129                         if (error)
2130                                 goto out;
2131                         index = next_index;
2132                 } else
2133                         index++;
2134         }
2135 
2136         if (index != hsize) {
2137                 gfs2_consist_inode(dip);
2138                 error = -EIO;
2139         }
2140 
2141 out:
2142 
2143         return error;
2144 }
2145 
2146 /**
2147  * gfs2_diradd_alloc_required - find if adding entry will require an allocation
2148  * @ip: the file being written to
2149  * @filname: the filename that's going to be added
2150  * @da: The structure to return dir alloc info
2151  *
2152  * Returns: 0 if ok, -ve on error
2153  */
2154 
2155 int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name,
2156                                struct gfs2_diradd *da)
2157 {
2158         struct gfs2_inode *ip = GFS2_I(inode);
2159         struct gfs2_sbd *sdp = GFS2_SB(inode);
2160         const unsigned int extra = sizeof(struct gfs2_dinode) - sizeof(struct gfs2_leaf);
2161         struct gfs2_dirent *dent;
2162         struct buffer_head *bh;
2163 
2164         da->nr_blocks = 0;
2165         da->bh = NULL;
2166         da->dent = NULL;
2167 
2168         dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
2169         if (!dent) {
2170                 da->nr_blocks = sdp->sd_max_dirres;
2171                 if (!(ip->i_diskflags & GFS2_DIF_EXHASH) &&
2172                     (GFS2_DIRENT_SIZE(name->len) < extra))
2173                         da->nr_blocks = 1;
2174                 return 0;
2175         }
2176         if (IS_ERR(dent))
2177                 return PTR_ERR(dent);
2178 
2179         if (da->save_loc) {
2180                 da->bh = bh;
2181                 da->dent = dent;
2182         } else {
2183                 brelse(bh);
2184         }
2185         return 0;
2186 }
2187
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root/fs/gfs2/dir.c

DEFINITIONS
