linux/fs/gfs2/dir.c
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   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 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
  84struct qstr gfs2_qdot __read_mostly;
  85struct qstr gfs2_qdotdot __read_mostly;
  86
  87typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent,
  88                            const struct qstr *name, void *opaque);
  89
  90int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
  91                            struct buffer_head **bhp)
  92{
  93        struct buffer_head *bh;
  94
  95        bh = gfs2_meta_new(ip->i_gl, block);
  96        gfs2_trans_add_bh(ip->i_gl, bh, 1);
  97        gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
  98        gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
  99        *bhp = bh;
 100        return 0;
 101}
 102
 103static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, u64 block,
 104                                        struct buffer_head **bhp)
 105{
 106        struct buffer_head *bh;
 107        int error;
 108
 109        error = gfs2_meta_read(ip->i_gl, block, DIO_WAIT, &bh);
 110        if (error)
 111                return error;
 112        if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_JD)) {
 113                brelse(bh);
 114                return -EIO;
 115        }
 116        *bhp = bh;
 117        return 0;
 118}
 119
 120static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
 121                                  unsigned int offset, unsigned int size)
 122{
 123        struct buffer_head *dibh;
 124        int error;
 125
 126        error = gfs2_meta_inode_buffer(ip, &dibh);
 127        if (error)
 128                return error;
 129
 130        gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 131        memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
 132        if (ip->i_inode.i_size < offset + size)
 133                i_size_write(&ip->i_inode, offset + size);
 134        ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 135        gfs2_dinode_out(ip, dibh->b_data);
 136
 137        brelse(dibh);
 138
 139        return size;
 140}
 141
 142
 143
 144/**
 145 * gfs2_dir_write_data - Write directory information to the inode
 146 * @ip: The GFS2 inode
 147 * @buf: The buffer containing information to be written
 148 * @offset: The file offset to start writing at
 149 * @size: The amount of data to write
 150 *
 151 * Returns: The number of bytes correctly written or error code
 152 */
 153static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
 154                               u64 offset, unsigned int size)
 155{
 156        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 157        struct buffer_head *dibh;
 158        u64 lblock, dblock;
 159        u32 extlen = 0;
 160        unsigned int o;
 161        int copied = 0;
 162        int error = 0;
 163        int new = 0;
 164
 165        if (!size)
 166                return 0;
 167
 168        if (gfs2_is_stuffed(ip) &&
 169            offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
 170                return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
 171                                              size);
 172
 173        if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
 174                return -EINVAL;
 175
 176        if (gfs2_is_stuffed(ip)) {
 177                error = gfs2_unstuff_dinode(ip, NULL);
 178                if (error)
 179                        return error;
 180        }
 181
 182        lblock = offset;
 183        o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
 184
 185        while (copied < size) {
 186                unsigned int amount;
 187                struct buffer_head *bh;
 188
 189                amount = size - copied;
 190                if (amount > sdp->sd_sb.sb_bsize - o)
 191                        amount = sdp->sd_sb.sb_bsize - o;
 192
 193                if (!extlen) {
 194                        new = 1;
 195                        error = gfs2_extent_map(&ip->i_inode, lblock, &new,
 196                                                &dblock, &extlen);
 197                        if (error)
 198                                goto fail;
 199                        error = -EIO;
 200                        if (gfs2_assert_withdraw(sdp, dblock))
 201                                goto fail;
 202                }
 203
 204                if (amount == sdp->sd_jbsize || new)
 205                        error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
 206                else
 207                        error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
 208
 209                if (error)
 210                        goto fail;
 211
 212                gfs2_trans_add_bh(ip->i_gl, bh, 1);
 213                memcpy(bh->b_data + o, buf, amount);
 214                brelse(bh);
 215
 216                buf += amount;
 217                copied += amount;
 218                lblock++;
 219                dblock++;
 220                extlen--;
 221
 222                o = sizeof(struct gfs2_meta_header);
 223        }
 224
 225out:
 226        error = gfs2_meta_inode_buffer(ip, &dibh);
 227        if (error)
 228                return error;
 229
 230        if (ip->i_inode.i_size < offset + copied)
 231                i_size_write(&ip->i_inode, offset + copied);
 232        ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 233
 234        gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 235        gfs2_dinode_out(ip, dibh->b_data);
 236        brelse(dibh);
 237
 238        return copied;
 239fail:
 240        if (copied)
 241                goto out;
 242        return error;
 243}
 244
 245static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, __be64 *buf,
 246                                 unsigned int size)
 247{
 248        struct buffer_head *dibh;
 249        int error;
 250
 251        error = gfs2_meta_inode_buffer(ip, &dibh);
 252        if (!error) {
 253                memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size);
 254                brelse(dibh);
 255        }
 256
 257        return (error) ? error : size;
 258}
 259
 260
 261/**
 262 * gfs2_dir_read_data - Read a data from a directory inode
 263 * @ip: The GFS2 Inode
 264 * @buf: The buffer to place result into
 265 * @size: Amount of data to transfer
 266 *
 267 * Returns: The amount of data actually copied or the error
 268 */
 269static int gfs2_dir_read_data(struct gfs2_inode *ip, __be64 *buf,
 270                              unsigned int size)
 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 (gfs2_is_stuffed(ip))
 280                return gfs2_dir_read_stuffed(ip, buf, size);
 281
 282        if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
 283                return -EINVAL;
 284
 285        lblock = 0;
 286        o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
 287
 288        while (copied < size) {
 289                unsigned int amount;
 290                struct buffer_head *bh;
 291                int new;
 292
 293                amount = size - copied;
 294                if (amount > sdp->sd_sb.sb_bsize - o)
 295                        amount = sdp->sd_sb.sb_bsize - o;
 296
 297                if (!extlen) {
 298                        new = 0;
 299                        error = gfs2_extent_map(&ip->i_inode, lblock, &new,
 300                                                &dblock, &extlen);
 301                        if (error || !dblock)
 302                                goto fail;
 303                        BUG_ON(extlen < 1);
 304                        bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
 305                } else {
 306                        error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, &bh);
 307                        if (error)
 308                                goto fail;
 309                }
 310                error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD);
 311                if (error) {
 312                        brelse(bh);
 313                        goto fail;
 314                }
 315                dblock++;
 316                extlen--;
 317                memcpy(buf, bh->b_data + o, amount);
 318                brelse(bh);
 319                buf += (amount/sizeof(__be64));
 320                copied += amount;
 321                lblock++;
 322                o = sizeof(struct gfs2_meta_header);
 323        }
 324
 325        return copied;
 326fail:
 327        return (copied) ? copied : error;
 328}
 329
 330/**
 331 * gfs2_dir_get_hash_table - Get pointer to the dir hash table
 332 * @ip: The inode in question
 333 *
 334 * Returns: The hash table or an error
 335 */
 336
 337static __be64 *gfs2_dir_get_hash_table(struct gfs2_inode *ip)
 338{
 339        struct inode *inode = &ip->i_inode;
 340        int ret;
 341        u32 hsize;
 342        __be64 *hc;
 343
 344        BUG_ON(!(ip->i_diskflags & GFS2_DIF_EXHASH));
 345
 346        hc = ip->i_hash_cache;
 347        if (hc)
 348                return hc;
 349
 350        hsize = 1 << ip->i_depth;
 351        hsize *= sizeof(__be64);
 352        if (hsize != i_size_read(&ip->i_inode)) {
 353                gfs2_consist_inode(ip);
 354                return ERR_PTR(-EIO);
 355        }
 356
 357        hc = kmalloc(hsize, GFP_NOFS);
 358        ret = -ENOMEM;
 359        if (hc == NULL)
 360                return ERR_PTR(-ENOMEM);
 361
 362        ret = gfs2_dir_read_data(ip, hc, hsize);
 363        if (ret < 0) {
 364                kfree(hc);
 365                return ERR_PTR(ret);
 366        }
 367
 368        spin_lock(&inode->i_lock);
 369        if (ip->i_hash_cache)
 370                kfree(hc);
 371        else
 372                ip->i_hash_cache = hc;
 373        spin_unlock(&inode->i_lock);
 374
 375        return ip->i_hash_cache;
 376}
 377
 378/**
 379 * gfs2_dir_hash_inval - Invalidate dir hash
 380 * @ip: The directory inode
 381 *
 382 * Must be called with an exclusive glock, or during glock invalidation.
 383 */
 384void gfs2_dir_hash_inval(struct gfs2_inode *ip)
 385{
 386        __be64 *hc = ip->i_hash_cache;
 387        ip->i_hash_cache = NULL;
 388        kfree(hc);
 389}
 390
 391static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent)
 392{
 393        return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0;
 394}
 395
 396static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
 397                                     const struct qstr *name, int ret)
 398{
 399        if (!gfs2_dirent_sentinel(dent) &&
 400            be32_to_cpu(dent->de_hash) == name->hash &&
 401            be16_to_cpu(dent->de_name_len) == name->len &&
 402            memcmp(dent+1, name->name, name->len) == 0)
 403                return ret;
 404        return 0;
 405}
 406
 407static int gfs2_dirent_find(const struct gfs2_dirent *dent,
 408                            const struct qstr *name,
 409                            void *opaque)
 410{
 411        return __gfs2_dirent_find(dent, name, 1);
 412}
 413
 414static int gfs2_dirent_prev(const struct gfs2_dirent *dent,
 415                            const struct qstr *name,
 416                            void *opaque)
 417{
 418        return __gfs2_dirent_find(dent, name, 2);
 419}
 420
 421/*
 422 * name->name holds ptr to start of block.
 423 * name->len holds size of block.
 424 */
 425static int gfs2_dirent_last(const struct gfs2_dirent *dent,
 426                            const struct qstr *name,
 427                            void *opaque)
 428{
 429        const char *start = name->name;
 430        const char *end = (const char *)dent + be16_to_cpu(dent->de_rec_len);
 431        if (name->len == (end - start))
 432                return 1;
 433        return 0;
 434}
 435
 436static int gfs2_dirent_find_space(const struct gfs2_dirent *dent,
 437                                  const struct qstr *name,
 438                                  void *opaque)
 439{
 440        unsigned required = GFS2_DIRENT_SIZE(name->len);
 441        unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 442        unsigned totlen = be16_to_cpu(dent->de_rec_len);
 443
 444        if (gfs2_dirent_sentinel(dent))
 445                actual = 0;
 446        if (totlen - actual >= required)
 447                return 1;
 448        return 0;
 449}
 450
 451struct dirent_gather {
 452        const struct gfs2_dirent **pdent;
 453        unsigned offset;
 454};
 455
 456static int gfs2_dirent_gather(const struct gfs2_dirent *dent,
 457                              const struct qstr *name,
 458                              void *opaque)
 459{
 460        struct dirent_gather *g = opaque;
 461        if (!gfs2_dirent_sentinel(dent)) {
 462                g->pdent[g->offset++] = dent;
 463        }
 464        return 0;
 465}
 466
 467/*
 468 * Other possible things to check:
 469 * - Inode located within filesystem size (and on valid block)
 470 * - Valid directory entry type
 471 * Not sure how heavy-weight we want to make this... could also check
 472 * hash is correct for example, but that would take a lot of extra time.
 473 * For now the most important thing is to check that the various sizes
 474 * are correct.
 475 */
 476static int gfs2_check_dirent(struct gfs2_dirent *dent, unsigned int offset,
 477                             unsigned int size, unsigned int len, int first)
 478{
 479        const char *msg = "gfs2_dirent too small";
 480        if (unlikely(size < sizeof(struct gfs2_dirent)))
 481                goto error;
 482        msg = "gfs2_dirent misaligned";
 483        if (unlikely(offset & 0x7))
 484                goto error;
 485        msg = "gfs2_dirent points beyond end of block";
 486        if (unlikely(offset + size > len))
 487                goto error;
 488        msg = "zero inode number";
 489        if (unlikely(!first && gfs2_dirent_sentinel(dent)))
 490                goto error;
 491        msg = "name length is greater than space in dirent";
 492        if (!gfs2_dirent_sentinel(dent) &&
 493            unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
 494                     size))
 495                goto error;
 496        return 0;
 497error:
 498        printk(KERN_WARNING "gfs2_check_dirent: %s (%s)\n", msg,
 499               first ? "first in block" : "not first in block");
 500        return -EIO;
 501}
 502
 503static int gfs2_dirent_offset(const void *buf)
 504{
 505        const struct gfs2_meta_header *h = buf;
 506        int offset;
 507
 508        BUG_ON(buf == NULL);
 509
 510        switch(be32_to_cpu(h->mh_type)) {
 511        case GFS2_METATYPE_LF:
 512                offset = sizeof(struct gfs2_leaf);
 513                break;
 514        case GFS2_METATYPE_DI:
 515                offset = sizeof(struct gfs2_dinode);
 516                break;
 517        default:
 518                goto wrong_type;
 519        }
 520        return offset;
 521wrong_type:
 522        printk(KERN_WARNING "gfs2_scan_dirent: wrong block type %u\n",
 523               be32_to_cpu(h->mh_type));
 524        return -1;
 525}
 526
 527static struct gfs2_dirent *gfs2_dirent_scan(struct inode *inode, void *buf,
 528                                            unsigned int len, gfs2_dscan_t scan,
 529                                            const struct qstr *name,
 530                                            void *opaque)
 531{
 532        struct gfs2_dirent *dent, *prev;
 533        unsigned offset;
 534        unsigned size;
 535        int ret = 0;
 536
 537        ret = gfs2_dirent_offset(buf);
 538        if (ret < 0)
 539                goto consist_inode;
 540
 541        offset = ret;
 542        prev = NULL;
 543        dent = buf + offset;
 544        size = be16_to_cpu(dent->de_rec_len);
 545        if (gfs2_check_dirent(dent, offset, size, len, 1))
 546                goto consist_inode;
 547        do {
 548                ret = scan(dent, name, opaque);
 549                if (ret)
 550                        break;
 551                offset += size;
 552                if (offset == len)
 553                        break;
 554                prev = dent;
 555                dent = buf + offset;
 556                size = be16_to_cpu(dent->de_rec_len);
 557                if (gfs2_check_dirent(dent, offset, size, len, 0))
 558                        goto consist_inode;
 559        } while(1);
 560
 561        switch(ret) {
 562        case 0:
 563                return NULL;
 564        case 1:
 565                return dent;
 566        case 2:
 567                return prev ? prev : dent;
 568        default:
 569                BUG_ON(ret > 0);
 570                return ERR_PTR(ret);
 571        }
 572
 573consist_inode:
 574        gfs2_consist_inode(GFS2_I(inode));
 575        return ERR_PTR(-EIO);
 576}
 577
 578static int dirent_check_reclen(struct gfs2_inode *dip,
 579                               const struct gfs2_dirent *d, const void *end_p)
 580{
 581        const void *ptr = d;
 582        u16 rec_len = be16_to_cpu(d->de_rec_len);
 583
 584        if (unlikely(rec_len < sizeof(struct gfs2_dirent)))
 585                goto broken;
 586        ptr += rec_len;
 587        if (ptr < end_p)
 588                return rec_len;
 589        if (ptr == end_p)
 590                return -ENOENT;
 591broken:
 592        gfs2_consist_inode(dip);
 593        return -EIO;
 594}
 595
 596/**
 597 * dirent_next - Next dirent
 598 * @dip: the directory
 599 * @bh: The buffer
 600 * @dent: Pointer to list of dirents
 601 *
 602 * Returns: 0 on success, error code otherwise
 603 */
 604
 605static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh,
 606                       struct gfs2_dirent **dent)
 607{
 608        struct gfs2_dirent *cur = *dent, *tmp;
 609        char *bh_end = bh->b_data + bh->b_size;
 610        int ret;
 611
 612        ret = dirent_check_reclen(dip, cur, bh_end);
 613        if (ret < 0)
 614                return ret;
 615
 616        tmp = (void *)cur + ret;
 617        ret = dirent_check_reclen(dip, tmp, bh_end);
 618        if (ret == -EIO)
 619                return ret;
 620
 621        /* Only the first dent could ever have de_inum.no_addr == 0 */
 622        if (gfs2_dirent_sentinel(tmp)) {
 623                gfs2_consist_inode(dip);
 624                return -EIO;
 625        }
 626
 627        *dent = tmp;
 628        return 0;
 629}
 630
 631/**
 632 * dirent_del - Delete a dirent
 633 * @dip: The GFS2 inode
 634 * @bh: The buffer
 635 * @prev: The previous dirent
 636 * @cur: The current dirent
 637 *
 638 */
 639
 640static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh,
 641                       struct gfs2_dirent *prev, struct gfs2_dirent *cur)
 642{
 643        u16 cur_rec_len, prev_rec_len;
 644
 645        if (gfs2_dirent_sentinel(cur)) {
 646                gfs2_consist_inode(dip);
 647                return;
 648        }
 649
 650        gfs2_trans_add_bh(dip->i_gl, bh, 1);
 651
 652        /* If there is no prev entry, this is the first entry in the block.
 653           The de_rec_len is already as big as it needs to be.  Just zero
 654           out the inode number and return.  */
 655
 656        if (!prev) {
 657                cur->de_inum.no_addr = 0;
 658                cur->de_inum.no_formal_ino = 0;
 659                return;
 660        }
 661
 662        /*  Combine this dentry with the previous one.  */
 663
 664        prev_rec_len = be16_to_cpu(prev->de_rec_len);
 665        cur_rec_len = be16_to_cpu(cur->de_rec_len);
 666
 667        if ((char *)prev + prev_rec_len != (char *)cur)
 668                gfs2_consist_inode(dip);
 669        if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size)
 670                gfs2_consist_inode(dip);
 671
 672        prev_rec_len += cur_rec_len;
 673        prev->de_rec_len = cpu_to_be16(prev_rec_len);
 674}
 675
 676/*
 677 * Takes a dent from which to grab space as an argument. Returns the
 678 * newly created dent.
 679 */
 680static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
 681                                            struct gfs2_dirent *dent,
 682                                            const struct qstr *name,
 683                                            struct buffer_head *bh)
 684{
 685        struct gfs2_inode *ip = GFS2_I(inode);
 686        struct gfs2_dirent *ndent;
 687        unsigned offset = 0, totlen;
 688
 689        if (!gfs2_dirent_sentinel(dent))
 690                offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 691        totlen = be16_to_cpu(dent->de_rec_len);
 692        BUG_ON(offset + name->len > totlen);
 693        gfs2_trans_add_bh(ip->i_gl, bh, 1);
 694        ndent = (struct gfs2_dirent *)((char *)dent + offset);
 695        dent->de_rec_len = cpu_to_be16(offset);
 696        gfs2_qstr2dirent(name, totlen - offset, ndent);
 697        return ndent;
 698}
 699
 700static struct gfs2_dirent *gfs2_dirent_alloc(struct inode *inode,
 701                                             struct buffer_head *bh,
 702                                             const struct qstr *name)
 703{
 704        struct gfs2_dirent *dent;
 705        dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 706                                gfs2_dirent_find_space, name, NULL);
 707        if (!dent || IS_ERR(dent))
 708                return dent;
 709        return gfs2_init_dirent(inode, dent, name, bh);
 710}
 711
 712static int get_leaf(struct gfs2_inode *dip, u64 leaf_no,
 713                    struct buffer_head **bhp)
 714{
 715        int error;
 716
 717        error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, bhp);
 718        if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) {
 719                /* printk(KERN_INFO "block num=%llu\n", leaf_no); */
 720                error = -EIO;
 721        }
 722
 723        return error;
 724}
 725
 726/**
 727 * get_leaf_nr - Get a leaf number associated with the index
 728 * @dip: The GFS2 inode
 729 * @index:
 730 * @leaf_out:
 731 *
 732 * Returns: 0 on success, error code otherwise
 733 */
 734
 735static int get_leaf_nr(struct gfs2_inode *dip, u32 index,
 736                       u64 *leaf_out)
 737{
 738        __be64 *hash;
 739
 740        hash = gfs2_dir_get_hash_table(dip);
 741        if (IS_ERR(hash))
 742                return PTR_ERR(hash);
 743        *leaf_out = be64_to_cpu(*(hash + index));
 744        return 0;
 745}
 746
 747static int get_first_leaf(struct gfs2_inode *dip, u32 index,
 748                          struct buffer_head **bh_out)
 749{
 750        u64 leaf_no;
 751        int error;
 752
 753        error = get_leaf_nr(dip, index, &leaf_no);
 754        if (!error)
 755                error = get_leaf(dip, leaf_no, bh_out);
 756
 757        return error;
 758}
 759
 760static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
 761                                              const struct qstr *name,
 762                                              gfs2_dscan_t scan,
 763                                              struct buffer_head **pbh)
 764{
 765        struct buffer_head *bh;
 766        struct gfs2_dirent *dent;
 767        struct gfs2_inode *ip = GFS2_I(inode);
 768        int error;
 769
 770        if (ip->i_diskflags & GFS2_DIF_EXHASH) {
 771                struct gfs2_leaf *leaf;
 772                unsigned hsize = 1 << ip->i_depth;
 773                unsigned index;
 774                u64 ln;
 775                if (hsize * sizeof(u64) != i_size_read(inode)) {
 776                        gfs2_consist_inode(ip);
 777                        return ERR_PTR(-EIO);
 778                }
 779
 780                index = name->hash >> (32 - ip->i_depth);
 781                error = get_first_leaf(ip, index, &bh);
 782                if (error)
 783                        return ERR_PTR(error);
 784                do {
 785                        dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 786                                                scan, name, NULL);
 787                        if (dent)
 788                                goto got_dent;
 789                        leaf = (struct gfs2_leaf *)bh->b_data;
 790                        ln = be64_to_cpu(leaf->lf_next);
 791                        brelse(bh);
 792                        if (!ln)
 793                                break;
 794
 795                        error = get_leaf(ip, ln, &bh);
 796                } while(!error);
 797
 798                return error ? ERR_PTR(error) : NULL;
 799        }
 800
 801
 802        error = gfs2_meta_inode_buffer(ip, &bh);
 803        if (error)
 804                return ERR_PTR(error);
 805        dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
 806got_dent:
 807        if (unlikely(dent == NULL || IS_ERR(dent))) {
 808                brelse(bh);
 809                bh = NULL;
 810        }
 811        *pbh = bh;
 812        return dent;
 813}
 814
 815static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
 816{
 817        struct gfs2_inode *ip = GFS2_I(inode);
 818        unsigned int n = 1;
 819        u64 bn;
 820        int error;
 821        struct buffer_head *bh;
 822        struct gfs2_leaf *leaf;
 823        struct gfs2_dirent *dent;
 824        struct qstr name = { .name = "" };
 825
 826        error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);
 827        if (error)
 828                return NULL;
 829        bh = gfs2_meta_new(ip->i_gl, bn);
 830        if (!bh)
 831                return NULL;
 832
 833        gfs2_trans_add_unrevoke(GFS2_SB(inode), bn, 1);
 834        gfs2_trans_add_bh(ip->i_gl, bh, 1);
 835        gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF);
 836        leaf = (struct gfs2_leaf *)bh->b_data;
 837        leaf->lf_depth = cpu_to_be16(depth);
 838        leaf->lf_entries = 0;
 839        leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
 840        leaf->lf_next = 0;
 841        memset(leaf->lf_reserved, 0, sizeof(leaf->lf_reserved));
 842        dent = (struct gfs2_dirent *)(leaf+1);
 843        gfs2_qstr2dirent(&name, bh->b_size - sizeof(struct gfs2_leaf), dent);
 844        *pbh = bh;
 845        return leaf;
 846}
 847
 848/**
 849 * dir_make_exhash - Convert a stuffed directory into an ExHash directory
 850 * @dip: The GFS2 inode
 851 *
 852 * Returns: 0 on success, error code otherwise
 853 */
 854
 855static int dir_make_exhash(struct inode *inode)
 856{
 857        struct gfs2_inode *dip = GFS2_I(inode);
 858        struct gfs2_sbd *sdp = GFS2_SB(inode);
 859        struct gfs2_dirent *dent;
 860        struct qstr args;
 861        struct buffer_head *bh, *dibh;
 862        struct gfs2_leaf *leaf;
 863        int y;
 864        u32 x;
 865        __be64 *lp;
 866        u64 bn;
 867        int error;
 868
 869        error = gfs2_meta_inode_buffer(dip, &dibh);
 870        if (error)
 871                return error;
 872
 873        /*  Turn over a new leaf  */
 874
 875        leaf = new_leaf(inode, &bh, 0);
 876        if (!leaf)
 877                return -ENOSPC;
 878        bn = bh->b_blocknr;
 879
 880        gfs2_assert(sdp, dip->i_entries < (1 << 16));
 881        leaf->lf_entries = cpu_to_be16(dip->i_entries);
 882
 883        /*  Copy dirents  */
 884
 885        gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
 886                             sizeof(struct gfs2_dinode));
 887
 888        /*  Find last entry  */
 889
 890        x = 0;
 891        args.len = bh->b_size - sizeof(struct gfs2_dinode) +
 892                   sizeof(struct gfs2_leaf);
 893        args.name = bh->b_data;
 894        dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size,
 895                                gfs2_dirent_last, &args, NULL);
 896        if (!dent) {
 897                brelse(bh);
 898                brelse(dibh);
 899                return -EIO;
 900        }
 901        if (IS_ERR(dent)) {
 902                brelse(bh);
 903                brelse(dibh);
 904                return PTR_ERR(dent);
 905        }
 906
 907        /*  Adjust the last dirent's record length
 908           (Remember that dent still points to the last entry.)  */
 909
 910        dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
 911                sizeof(struct gfs2_dinode) -
 912                sizeof(struct gfs2_leaf));
 913
 914        brelse(bh);
 915
 916        /*  We're done with the new leaf block, now setup the new
 917            hash table.  */
 918
 919        gfs2_trans_add_bh(dip->i_gl, dibh, 1);
 920        gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
 921
 922        lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
 923
 924        for (x = sdp->sd_hash_ptrs; x--; lp++)
 925                *lp = cpu_to_be64(bn);
 926
 927        i_size_write(inode, sdp->sd_sb.sb_bsize / 2);
 928        gfs2_add_inode_blocks(&dip->i_inode, 1);
 929        dip->i_diskflags |= GFS2_DIF_EXHASH;
 930
 931        for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
 932        dip->i_depth = y;
 933
 934        gfs2_dinode_out(dip, dibh->b_data);
 935
 936        brelse(dibh);
 937
 938        return 0;
 939}
 940
 941/**
 942 * dir_split_leaf - Split a leaf block into two
 943 * @dip: The GFS2 inode
 944 * @index:
 945 * @leaf_no:
 946 *
 947 * Returns: 0 on success, error code on failure
 948 */
 949
 950static int dir_split_leaf(struct inode *inode, const struct qstr *name)
 951{
 952        struct gfs2_inode *dip = GFS2_I(inode);
 953        struct buffer_head *nbh, *obh, *dibh;
 954        struct gfs2_leaf *nleaf, *oleaf;
 955        struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new;
 956        u32 start, len, half_len, divider;
 957        u64 bn, leaf_no;
 958        __be64 *lp;
 959        u32 index;
 960        int x, moved = 0;
 961        int error;
 962
 963        index = name->hash >> (32 - dip->i_depth);
 964        error = get_leaf_nr(dip, index, &leaf_no);
 965        if (error)
 966                return error;
 967
 968        /*  Get the old leaf block  */
 969        error = get_leaf(dip, leaf_no, &obh);
 970        if (error)
 971                return error;
 972
 973        oleaf = (struct gfs2_leaf *)obh->b_data;
 974        if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
 975                brelse(obh);
 976                return 1; /* can't split */
 977        }
 978
 979        gfs2_trans_add_bh(dip->i_gl, obh, 1);
 980
 981        nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
 982        if (!nleaf) {
 983                brelse(obh);
 984                return -ENOSPC;
 985        }
 986        bn = nbh->b_blocknr;
 987
 988        /*  Compute the start and len of leaf pointers in the hash table.  */
 989        len = 1 << (dip->i_depth - be16_to_cpu(oleaf->lf_depth));
 990        half_len = len >> 1;
 991        if (!half_len) {
 992                printk(KERN_WARNING "i_depth %u lf_depth %u index %u\n", dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
 993                gfs2_consist_inode(dip);
 994                error = -EIO;
 995                goto fail_brelse;
 996        }
 997
 998        start = (index & ~(len - 1));
 999
1000        /* Change the pointers.
1001           Don't bother distinguishing stuffed from non-stuffed.
1002           This code is complicated enough already. */
1003        lp = kmalloc(half_len * sizeof(__be64), GFP_NOFS);
1004        if (!lp) {
1005                error = -ENOMEM;
1006                goto fail_brelse;
1007        }
1008
1009        /*  Change the pointers  */
1010        for (x = 0; x < half_len; x++)
1011                lp[x] = cpu_to_be64(bn);
1012
1013        gfs2_dir_hash_inval(dip);
1014
1015        error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64),
1016                                    half_len * sizeof(u64));
1017        if (error != half_len * sizeof(u64)) {
1018                if (error >= 0)
1019                        error = -EIO;
1020                goto fail_lpfree;
1021        }
1022
1023        kfree(lp);
1024
1025        /*  Compute the divider  */
1026        divider = (start + half_len) << (32 - dip->i_depth);
1027
1028        /*  Copy the entries  */
1029        dent = (struct gfs2_dirent *)(obh->b_data + sizeof(struct gfs2_leaf));
1030
1031        do {
1032                next = dent;
1033                if (dirent_next(dip, obh, &next))
1034                        next = NULL;
1035
1036                if (!gfs2_dirent_sentinel(dent) &&
1037                    be32_to_cpu(dent->de_hash) < divider) {
1038                        struct qstr str;
1039                        str.name = (char*)(dent+1);
1040                        str.len = be16_to_cpu(dent->de_name_len);
1041                        str.hash = be32_to_cpu(dent->de_hash);
1042                        new = gfs2_dirent_alloc(inode, nbh, &str);
1043                        if (IS_ERR(new)) {
1044                                error = PTR_ERR(new);
1045                                break;
1046                        }
1047
1048                        new->de_inum = dent->de_inum; /* No endian worries */
1049                        new->de_type = dent->de_type; /* No endian worries */
1050                        be16_add_cpu(&nleaf->lf_entries, 1);
1051
1052                        dirent_del(dip, obh, prev, dent);
1053
1054                        if (!oleaf->lf_entries)
1055                                gfs2_consist_inode(dip);
1056                        be16_add_cpu(&oleaf->lf_entries, -1);
1057
1058                        if (!prev)
1059                                prev = dent;
1060
1061                        moved = 1;
1062                } else {
1063                        prev = dent;
1064                }
1065                dent = next;
1066        } while (dent);
1067
1068        oleaf->lf_depth = nleaf->lf_depth;
1069
1070        error = gfs2_meta_inode_buffer(dip, &dibh);
1071        if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) {
1072                gfs2_trans_add_bh(dip->i_gl, dibh, 1);
1073                gfs2_add_inode_blocks(&dip->i_inode, 1);
1074                gfs2_dinode_out(dip, dibh->b_data);
1075                brelse(dibh);
1076        }
1077
1078        brelse(obh);
1079        brelse(nbh);
1080
1081        return error;
1082
1083fail_lpfree:
1084        kfree(lp);
1085
1086fail_brelse:
1087        brelse(obh);
1088        brelse(nbh);
1089        return error;
1090}
1091
1092/**
1093 * dir_double_exhash - Double size of ExHash table
1094 * @dip: The GFS2 dinode
1095 *
1096 * Returns: 0 on success, error code on failure
1097 */
1098
1099static int dir_double_exhash(struct gfs2_inode *dip)
1100{
1101        struct buffer_head *dibh;
1102        u32 hsize;
1103        u32 hsize_bytes;
1104        __be64 *hc;
1105        __be64 *hc2, *h;
1106        int x;
1107        int error = 0;
1108
1109        hsize = 1 << dip->i_depth;
1110        hsize_bytes = hsize * sizeof(__be64);
1111
1112        hc = gfs2_dir_get_hash_table(dip);
1113        if (IS_ERR(hc))
1114                return PTR_ERR(hc);
1115
1116        h = hc2 = kmalloc(hsize_bytes * 2, GFP_NOFS);
1117        if (!hc2)
1118                return -ENOMEM;
1119
1120        error = gfs2_meta_inode_buffer(dip, &dibh);
1121        if (error)
1122                goto out_kfree;
1123
1124        for (x = 0; x < hsize; x++) {
1125                *h++ = *hc;
1126                *h++ = *hc;
1127                hc++;
1128        }
1129
1130        error = gfs2_dir_write_data(dip, (char *)hc2, 0, hsize_bytes * 2);
1131        if (error != (hsize_bytes * 2))
1132                goto fail;
1133
1134        gfs2_dir_hash_inval(dip);
1135        dip->i_hash_cache = hc2;
1136        dip->i_depth++;
1137        gfs2_dinode_out(dip, dibh->b_data);
1138        brelse(dibh);
1139        return 0;
1140
1141fail:
1142        /* Replace original hash table & size */
1143        gfs2_dir_write_data(dip, (char *)hc, 0, hsize_bytes);
1144        i_size_write(&dip->i_inode, hsize_bytes);
1145        gfs2_dinode_out(dip, dibh->b_data);
1146        brelse(dibh);
1147out_kfree:
1148        kfree(hc2);
1149        return error;
1150}
1151
1152/**
1153 * compare_dents - compare directory entries by hash value
1154 * @a: first dent
1155 * @b: second dent
1156 *
1157 * When comparing the hash entries of @a to @b:
1158 *   gt: returns 1
1159 *   lt: returns -1
1160 *   eq: returns 0
1161 */
1162
1163static int compare_dents(const void *a, const void *b)
1164{
1165        const struct gfs2_dirent *dent_a, *dent_b;
1166        u32 hash_a, hash_b;
1167        int ret = 0;
1168
1169        dent_a = *(const struct gfs2_dirent **)a;
1170        hash_a = be32_to_cpu(dent_a->de_hash);
1171
1172        dent_b = *(const struct gfs2_dirent **)b;
1173        hash_b = be32_to_cpu(dent_b->de_hash);
1174
1175        if (hash_a > hash_b)
1176                ret = 1;
1177        else if (hash_a < hash_b)
1178                ret = -1;
1179        else {
1180                unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
1181                unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
1182
1183                if (len_a > len_b)
1184                        ret = 1;
1185                else if (len_a < len_b)
1186                        ret = -1;
1187                else
1188                        ret = memcmp(dent_a + 1, dent_b + 1, len_a);
1189        }
1190
1191        return ret;
1192}
1193
1194/**
1195 * do_filldir_main - read out directory entries
1196 * @dip: The GFS2 inode
1197 * @offset: The offset in the file to read from
1198 * @opaque: opaque data to pass to filldir
1199 * @filldir: The function to pass entries to
1200 * @darr: an array of struct gfs2_dirent pointers to read
1201 * @entries: the number of entries in darr
1202 * @copied: pointer to int that's non-zero if a entry has been copied out
1203 *
1204 * Jump through some hoops to make sure that if there are hash collsions,
1205 * they are read out at the beginning of a buffer.  We want to minimize
1206 * the possibility that they will fall into different readdir buffers or
1207 * that someone will want to seek to that location.
1208 *
1209 * Returns: errno, >0 on exception from filldir
1210 */
1211
1212static int do_filldir_main(struct gfs2_inode *dip, u64 *offset,
1213                           void *opaque, filldir_t filldir,
1214                           const struct gfs2_dirent **darr, u32 entries,
1215                           int *copied)
1216{
1217        const struct gfs2_dirent *dent, *dent_next;
1218        u64 off, off_next;
1219        unsigned int x, y;
1220        int run = 0;
1221        int error = 0;
1222
1223        sort(darr, entries, sizeof(struct gfs2_dirent *), compare_dents, NULL);
1224
1225        dent_next = darr[0];
1226        off_next = be32_to_cpu(dent_next->de_hash);
1227        off_next = gfs2_disk_hash2offset(off_next);
1228
1229        for (x = 0, y = 1; x < entries; x++, y++) {
1230                dent = dent_next;
1231                off = off_next;
1232
1233                if (y < entries) {
1234                        dent_next = darr[y];
1235                        off_next = be32_to_cpu(dent_next->de_hash);
1236                        off_next = gfs2_disk_hash2offset(off_next);
1237
1238                        if (off < *offset)
1239                                continue;
1240                        *offset = off;
1241
1242                        if (off_next == off) {
1243                                if (*copied && !run)
1244                                        return 1;
1245                                run = 1;
1246                        } else
1247                                run = 0;
1248                } else {
1249                        if (off < *offset)
1250                                continue;
1251                        *offset = off;
1252                }
1253
1254                error = filldir(opaque, (const char *)(dent + 1),
1255                                be16_to_cpu(dent->de_name_len),
1256                                off, be64_to_cpu(dent->de_inum.no_addr),
1257                                be16_to_cpu(dent->de_type));
1258                if (error)
1259                        return 1;
1260
1261                *copied = 1;
1262        }
1263
1264        /* Increment the *offset by one, so the next time we come into the
1265           do_filldir fxn, we get the next entry instead of the last one in the
1266           current leaf */
1267
1268        (*offset)++;
1269
1270        return 0;
1271}
1272
1273static void *gfs2_alloc_sort_buffer(unsigned size)
1274{
1275        void *ptr = NULL;
1276
1277        if (size < KMALLOC_MAX_SIZE)
1278                ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN);
1279        if (!ptr)
1280                ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL);
1281        return ptr;
1282}
1283
1284static void gfs2_free_sort_buffer(void *ptr)
1285{
1286        if (is_vmalloc_addr(ptr))
1287                vfree(ptr);
1288        else
1289                kfree(ptr);
1290}
1291
1292static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
1293                              filldir_t filldir, int *copied, unsigned *depth,
1294                              u64 leaf_no)
1295{
1296        struct gfs2_inode *ip = GFS2_I(inode);
1297        struct gfs2_sbd *sdp = GFS2_SB(inode);
1298        struct buffer_head *bh;
1299        struct gfs2_leaf *lf;
1300        unsigned entries = 0, entries2 = 0;
1301        unsigned leaves = 0;
1302        const struct gfs2_dirent **darr, *dent;
1303        struct dirent_gather g;
1304        struct buffer_head **larr;
1305        int leaf = 0;
1306        int error, i;
1307        u64 lfn = leaf_no;
1308
1309        do {
1310                error = get_leaf(ip, lfn, &bh);
1311                if (error)
1312                        goto out;
1313                lf = (struct gfs2_leaf *)bh->b_data;
1314                if (leaves == 0)
1315                        *depth = be16_to_cpu(lf->lf_depth);
1316                entries += be16_to_cpu(lf->lf_entries);
1317                leaves++;
1318                lfn = be64_to_cpu(lf->lf_next);
1319                brelse(bh);
1320        } while(lfn);
1321
1322        if (!entries)
1323                return 0;
1324
1325        error = -ENOMEM;
1326        /*
1327         * The extra 99 entries are not normally used, but are a buffer
1328         * zone in case the number of entries in the leaf is corrupt.
1329         * 99 is the maximum number of entries that can fit in a single
1330         * leaf block.
1331         */
1332        larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *));
1333        if (!larr)
1334                goto out;
1335        darr = (const struct gfs2_dirent **)(larr + leaves);
1336        g.pdent = darr;
1337        g.offset = 0;
1338        lfn = leaf_no;
1339
1340        do {
1341                error = get_leaf(ip, lfn, &bh);
1342                if (error)
1343                        goto out_free;
1344                lf = (struct gfs2_leaf *)bh->b_data;
1345                lfn = be64_to_cpu(lf->lf_next);
1346                if (lf->lf_entries) {
1347                        entries2 += be16_to_cpu(lf->lf_entries);
1348                        dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
1349                                                gfs2_dirent_gather, NULL, &g);
1350                        error = PTR_ERR(dent);
1351                        if (IS_ERR(dent))
1352                                goto out_free;
1353                        if (entries2 != g.offset) {
1354                                fs_warn(sdp, "Number of entries corrupt in dir "
1355                                                "leaf %llu, entries2 (%u) != "
1356                                                "g.offset (%u)\n",
1357                                        (unsigned long long)bh->b_blocknr,
1358                                        entries2, g.offset);
1359                                        
1360                                error = -EIO;
1361                                goto out_free;
1362                        }
1363                        error = 0;
1364                        larr[leaf++] = bh;
1365                } else {
1366                        brelse(bh);
1367                }
1368        } while(lfn);
1369
1370        BUG_ON(entries2 != entries);
1371        error = do_filldir_main(ip, offset, opaque, filldir, darr,
1372                                entries, copied);
1373out_free:
1374        for(i = 0; i < leaf; i++)
1375                brelse(larr[i]);
1376        gfs2_free_sort_buffer(larr);
1377out:
1378        return error;
1379}
1380
1381/**
1382 * gfs2_dir_readahead - Issue read-ahead requests for leaf blocks.
1383 *
1384 * Note: we can't calculate each index like dir_e_read can because we don't
1385 * have the leaf, and therefore we don't have the depth, and therefore we
1386 * don't have the length. So we have to just read enough ahead to make up
1387 * for the loss of information.
1388 */
1389static void gfs2_dir_readahead(struct inode *inode, unsigned hsize, u32 index,
1390                               struct file_ra_state *f_ra)
1391{
1392        struct gfs2_inode *ip = GFS2_I(inode);
1393        struct gfs2_glock *gl = ip->i_gl;
1394        struct buffer_head *bh;
1395        u64 blocknr = 0, last;
1396        unsigned count;
1397
1398        /* First check if we've already read-ahead for the whole range. */
1399        if (index + MAX_RA_BLOCKS < f_ra->start)
1400                return;
1401
1402        f_ra->start = max((pgoff_t)index, f_ra->start);
1403        for (count = 0; count < MAX_RA_BLOCKS; count++) {
1404                if (f_ra->start >= hsize) /* if exceeded the hash table */
1405                        break;
1406
1407                last = blocknr;
1408                blocknr = be64_to_cpu(ip->i_hash_cache[f_ra->start]);
1409                f_ra->start++;
1410                if (blocknr == last)
1411                        continue;
1412
1413                bh = gfs2_getbuf(gl, blocknr, 1);
1414                if (trylock_buffer(bh)) {
1415                        if (buffer_uptodate(bh)) {
1416                                unlock_buffer(bh);
1417                                brelse(bh);
1418                                continue;
1419                        }
1420                        bh->b_end_io = end_buffer_read_sync;
1421                        submit_bh(READA | REQ_META, bh);
1422                        continue;
1423                }
1424                brelse(bh);
1425        }
1426}
1427
1428/**
1429 * dir_e_read - Reads the entries from a directory into a filldir buffer
1430 * @dip: dinode pointer
1431 * @offset: the hash of the last entry read shifted to the right once
1432 * @opaque: buffer for the filldir function to fill
1433 * @filldir: points to the filldir function to use
1434 *
1435 * Returns: errno
1436 */
1437
1438static int dir_e_read(struct inode *inode, u64 *offset, void *opaque,
1439                      filldir_t filldir, struct file_ra_state *f_ra)
1440{
1441        struct gfs2_inode *dip = GFS2_I(inode);
1442        u32 hsize, len = 0;
1443        u32 hash, index;
1444        __be64 *lp;
1445        int copied = 0;
1446        int error = 0;
1447        unsigned depth = 0;
1448
1449        hsize = 1 << dip->i_depth;
1450        hash = gfs2_dir_offset2hash(*offset);
1451        index = hash >> (32 - dip->i_depth);
1452
1453        if (dip->i_hash_cache == NULL)
1454                f_ra->start = 0;
1455        lp = gfs2_dir_get_hash_table(dip);
1456        if (IS_ERR(lp))
1457                return PTR_ERR(lp);
1458
1459        gfs2_dir_readahead(inode, hsize, index, f_ra);
1460
1461        while (index < hsize) {
1462                error = gfs2_dir_read_leaf(inode, offset, opaque, filldir,
1463                                           &copied, &depth,
1464                                           be64_to_cpu(lp[index]));
1465                if (error)
1466                        break;
1467
1468                len = 1 << (dip->i_depth - depth);
1469                index = (index & ~(len - 1)) + len;
1470        }
1471
1472        if (error > 0)
1473                error = 0;
1474        return error;
1475}
1476
1477int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque,
1478                  filldir_t filldir, struct file_ra_state *f_ra)
1479{
1480        struct gfs2_inode *dip = GFS2_I(inode);
1481        struct gfs2_sbd *sdp = GFS2_SB(inode);
1482        struct dirent_gather g;
1483        const struct gfs2_dirent **darr, *dent;
1484        struct buffer_head *dibh;
1485        int copied = 0;
1486        int error;
1487
1488        if (!dip->i_entries)
1489                return 0;
1490
1491        if (dip->i_diskflags & GFS2_DIF_EXHASH)
1492                return dir_e_read(inode, offset, opaque, filldir, f_ra);
1493
1494        if (!gfs2_is_stuffed(dip)) {
1495                gfs2_consist_inode(dip);
1496                return -EIO;
1497        }
1498
1499        error = gfs2_meta_inode_buffer(dip, &dibh);
1500        if (error)
1501                return error;
1502
1503        error = -ENOMEM;
1504        /* 96 is max number of dirents which can be stuffed into an inode */
1505        darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_NOFS);
1506        if (darr) {
1507                g.pdent = darr;
1508                g.offset = 0;
1509                dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size,
1510                                        gfs2_dirent_gather, NULL, &g);
1511                if (IS_ERR(dent)) {
1512                        error = PTR_ERR(dent);
1513                        goto out;
1514                }
1515                if (dip->i_entries != g.offset) {
1516                        fs_warn(sdp, "Number of entries corrupt in dir %llu, "
1517                                "ip->i_entries (%u) != g.offset (%u)\n",
1518                                (unsigned long long)dip->i_no_addr,
1519                                dip->i_entries,
1520                                g.offset);
1521                        error = -EIO;
1522                        goto out;
1523                }
1524                error = do_filldir_main(dip, offset, opaque, filldir, darr,
1525                                        dip->i_entries, &copied);
1526out:
1527                kfree(darr);
1528        }
1529
1530        if (error > 0)
1531                error = 0;
1532
1533        brelse(dibh);
1534
1535        return error;
1536}
1537
1538/**
1539 * gfs2_dir_search - Search a directory
1540 * @dip: The GFS2 inode
1541 * @filename:
1542 * @inode:
1543 *
1544 * This routine searches a directory for a file or another directory.
1545 * Assumes a glock is held on dip.
1546 *
1547 * Returns: errno
1548 */
1549
1550struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name)
1551{
1552        struct buffer_head *bh;
1553        struct gfs2_dirent *dent;
1554        struct inode *inode;
1555
1556        dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1557        if (dent) {
1558                if (IS_ERR(dent))
1559                        return ERR_CAST(dent);
1560                inode = gfs2_inode_lookup(dir->i_sb, 
1561                                be16_to_cpu(dent->de_type),
1562                                be64_to_cpu(dent->de_inum.no_addr),
1563                                be64_to_cpu(dent->de_inum.no_formal_ino), 0);
1564                brelse(bh);
1565                return inode;
1566        }
1567        return ERR_PTR(-ENOENT);
1568}
1569
1570int gfs2_dir_check(struct inode *dir, const struct qstr *name,
1571                   const struct gfs2_inode *ip)
1572{
1573        struct buffer_head *bh;
1574        struct gfs2_dirent *dent;
1575        int ret = -ENOENT;
1576
1577        dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1578        if (dent) {
1579                if (IS_ERR(dent))
1580                        return PTR_ERR(dent);
1581                if (ip) {
1582                        if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
1583                                goto out;
1584                        if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
1585                            ip->i_no_formal_ino)
1586                                goto out;
1587                        if (unlikely(IF2DT(ip->i_inode.i_mode) !=
1588                            be16_to_cpu(dent->de_type))) {
1589                                gfs2_consist_inode(GFS2_I(dir));
1590                                ret = -EIO;
1591                                goto out;
1592                        }
1593                }
1594                ret = 0;
1595out:
1596                brelse(bh);
1597        }
1598        return ret;
1599}
1600
1601static int dir_new_leaf(struct inode *inode, const struct qstr *name)
1602{
1603        struct buffer_head *bh, *obh;
1604        struct gfs2_inode *ip = GFS2_I(inode);
1605        struct gfs2_leaf *leaf, *oleaf;
1606        int error;
1607        u32 index;
1608        u64 bn;
1609
1610        index = name->hash >> (32 - ip->i_depth);
1611        error = get_first_leaf(ip, index, &obh);
1612        if (error)
1613                return error;
1614        do {
1615                oleaf = (struct gfs2_leaf *)obh->b_data;
1616                bn = be64_to_cpu(oleaf->lf_next);
1617                if (!bn)
1618                        break;
1619                brelse(obh);
1620                error = get_leaf(ip, bn, &obh);
1621                if (error)
1622                        return error;
1623        } while(1);
1624
1625        gfs2_trans_add_bh(ip->i_gl, obh, 1);
1626
1627        leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
1628        if (!leaf) {
1629                brelse(obh);
1630                return -ENOSPC;
1631        }
1632        oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
1633        brelse(bh);
1634        brelse(obh);
1635
1636        error = gfs2_meta_inode_buffer(ip, &bh);
1637        if (error)
1638                return error;
1639        gfs2_trans_add_bh(ip->i_gl, bh, 1);
1640        gfs2_add_inode_blocks(&ip->i_inode, 1);
1641        gfs2_dinode_out(ip, bh->b_data);
1642        brelse(bh);
1643        return 0;
1644}
1645
1646/**
1647 * gfs2_dir_add - Add new filename into directory
1648 * @dip: The GFS2 inode
1649 * @filename: The new name
1650 * @inode: The inode number of the entry
1651 * @type: The type of the entry
1652 *
1653 * Returns: 0 on success, error code on failure
1654 */
1655
1656int gfs2_dir_add(struct inode *inode, const struct qstr *name,
1657                 const struct gfs2_inode *nip)
1658{
1659        struct gfs2_inode *ip = GFS2_I(inode);
1660        struct buffer_head *bh;
1661        struct gfs2_dirent *dent;
1662        struct gfs2_leaf *leaf;
1663        int error;
1664
1665        while(1) {
1666                dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space,
1667                                          &bh);
1668                if (dent) {
1669                        if (IS_ERR(dent))
1670                                return PTR_ERR(dent);
1671                        dent = gfs2_init_dirent(inode, dent, name, bh);
1672                        gfs2_inum_out(nip, dent);
1673                        dent->de_type = cpu_to_be16(IF2DT(nip->i_inode.i_mode));
1674                        if (ip->i_diskflags & GFS2_DIF_EXHASH) {
1675                                leaf = (struct gfs2_leaf *)bh->b_data;
1676                                be16_add_cpu(&leaf->lf_entries, 1);
1677                        }
1678                        brelse(bh);
1679                        error = gfs2_meta_inode_buffer(ip, &bh);
1680                        if (error)
1681                                break;
1682                        gfs2_trans_add_bh(ip->i_gl, bh, 1);
1683                        ip->i_entries++;
1684                        ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
1685                        if (S_ISDIR(nip->i_inode.i_mode))
1686                                inc_nlink(&ip->i_inode);
1687                        gfs2_dinode_out(ip, bh->b_data);
1688                        brelse(bh);
1689                        error = 0;
1690                        break;
1691                }
1692                if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) {
1693                        error = dir_make_exhash(inode);
1694                        if (error)
1695                                break;
1696                        continue;
1697                }
1698                error = dir_split_leaf(inode, name);
1699                if (error == 0)
1700                        continue;
1701                if (error < 0)
1702                        break;
1703                if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
1704                        error = dir_double_exhash(ip);
1705                        if (error)
1706                                break;
1707                        error = dir_split_leaf(inode, name);
1708                        if (error < 0)
1709                                break;
1710                        if (error == 0)
1711                                continue;
1712                }
1713                error = dir_new_leaf(inode, name);
1714                if (!error)
1715                        continue;
1716                error = -ENOSPC;
1717                break;
1718        }
1719        return error;
1720}
1721
1722
1723/**
1724 * gfs2_dir_del - Delete a directory entry
1725 * @dip: The GFS2 inode
1726 * @filename: The filename
1727 *
1728 * Returns: 0 on success, error code on failure
1729 */
1730
1731int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry)
1732{
1733        const struct qstr *name = &dentry->d_name;
1734        struct gfs2_dirent *dent, *prev = NULL;
1735        struct buffer_head *bh;
1736
1737        /* Returns _either_ the entry (if its first in block) or the
1738           previous entry otherwise */
1739        dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh);
1740        if (!dent) {
1741                gfs2_consist_inode(dip);
1742                return -EIO;
1743        }
1744        if (IS_ERR(dent)) {
1745                gfs2_consist_inode(dip);
1746                return PTR_ERR(dent);
1747        }
1748        /* If not first in block, adjust pointers accordingly */
1749        if (gfs2_dirent_find(dent, name, NULL) == 0) {
1750                prev = dent;
1751                dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
1752        }
1753
1754        dirent_del(dip, bh, prev, dent);
1755        if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1756                struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
1757                u16 entries = be16_to_cpu(leaf->lf_entries);
1758                if (!entries)
1759                        gfs2_consist_inode(dip);
1760                leaf->lf_entries = cpu_to_be16(--entries);
1761        }
1762        brelse(bh);
1763
1764        if (!dip->i_entries)
1765                gfs2_consist_inode(dip);
1766        dip->i_entries--;
1767        dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1768        if (S_ISDIR(dentry->d_inode->i_mode))
1769                drop_nlink(&dip->i_inode);
1770        mark_inode_dirty(&dip->i_inode);
1771
1772        return 0;
1773}
1774
1775/**
1776 * gfs2_dir_mvino - Change inode number of directory entry
1777 * @dip: The GFS2 inode
1778 * @filename:
1779 * @new_inode:
1780 *
1781 * This routine changes the inode number of a directory entry.  It's used
1782 * by rename to change ".." when a directory is moved.
1783 * Assumes a glock is held on dvp.
1784 *
1785 * Returns: errno
1786 */
1787
1788int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
1789                   const struct gfs2_inode *nip, unsigned int new_type)
1790{
1791        struct buffer_head *bh;
1792        struct gfs2_dirent *dent;
1793        int error;
1794
1795        dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh);
1796        if (!dent) {
1797                gfs2_consist_inode(dip);
1798                return -EIO;
1799        }
1800        if (IS_ERR(dent))
1801                return PTR_ERR(dent);
1802
1803        gfs2_trans_add_bh(dip->i_gl, bh, 1);
1804        gfs2_inum_out(nip, dent);
1805        dent->de_type = cpu_to_be16(new_type);
1806
1807        if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1808                brelse(bh);
1809                error = gfs2_meta_inode_buffer(dip, &bh);
1810                if (error)
1811                        return error;
1812                gfs2_trans_add_bh(dip->i_gl, bh, 1);
1813        }
1814
1815        dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1816        gfs2_dinode_out(dip, bh->b_data);
1817        brelse(bh);
1818        return 0;
1819}
1820
1821/**
1822 * leaf_dealloc - Deallocate a directory leaf
1823 * @dip: the directory
1824 * @index: the hash table offset in the directory
1825 * @len: the number of pointers to this leaf
1826 * @leaf_no: the leaf number
1827 * @leaf_bh: buffer_head for the starting leaf
1828 * last_dealloc: 1 if this is the final dealloc for the leaf, else 0
1829 *
1830 * Returns: errno
1831 */
1832
1833static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len,
1834                        u64 leaf_no, struct buffer_head *leaf_bh,
1835                        int last_dealloc)
1836{
1837        struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1838        struct gfs2_leaf *tmp_leaf;
1839        struct gfs2_rgrp_list rlist;
1840        struct buffer_head *bh, *dibh;
1841        u64 blk, nblk;
1842        unsigned int rg_blocks = 0, l_blocks = 0;
1843        char *ht;
1844        unsigned int x, size = len * sizeof(u64);
1845        int error;
1846
1847        error = gfs2_rindex_update(sdp);
1848        if (error)
1849                return error;
1850
1851        memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
1852
1853        ht = kzalloc(size, GFP_NOFS);
1854        if (!ht)
1855                return -ENOMEM;
1856
1857        error = gfs2_quota_hold(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
1858        if (error)
1859                goto out;
1860
1861        /*  Count the number of leaves  */
1862        bh = leaf_bh;
1863
1864        for (blk = leaf_no; blk; blk = nblk) {
1865                if (blk != leaf_no) {
1866                        error = get_leaf(dip, blk, &bh);
1867                        if (error)
1868                                goto out_rlist;
1869                }
1870                tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1871                nblk = be64_to_cpu(tmp_leaf->lf_next);
1872                if (blk != leaf_no)
1873                        brelse(bh);
1874
1875                gfs2_rlist_add(dip, &rlist, blk);
1876                l_blocks++;
1877        }
1878
1879        gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
1880
1881        for (x = 0; x < rlist.rl_rgrps; x++) {
1882                struct gfs2_rgrpd *rgd;
1883                rgd = rlist.rl_ghs[x].gh_gl->gl_object;
1884                rg_blocks += rgd->rd_length;
1885        }
1886
1887        error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
1888        if (error)
1889                goto out_rlist;
1890
1891        error = gfs2_trans_begin(sdp,
1892                        rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
1893                        RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
1894        if (error)
1895                goto out_rg_gunlock;
1896
1897        bh = leaf_bh;
1898
1899        for (blk = leaf_no; blk; blk = nblk) {
1900                if (blk != leaf_no) {
1901                        error = get_leaf(dip, blk, &bh);
1902                        if (error)
1903                                goto out_end_trans;
1904                }
1905                tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1906                nblk = be64_to_cpu(tmp_leaf->lf_next);
1907                if (blk != leaf_no)
1908                        brelse(bh);
1909
1910                gfs2_free_meta(dip, blk, 1);
1911                gfs2_add_inode_blocks(&dip->i_inode, -1);
1912        }
1913
1914        error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size);
1915        if (error != size) {
1916                if (error >= 0)
1917                        error = -EIO;
1918                goto out_end_trans;
1919        }
1920
1921        error = gfs2_meta_inode_buffer(dip, &dibh);
1922        if (error)
1923                goto out_end_trans;
1924
1925        gfs2_trans_add_bh(dip->i_gl, dibh, 1);
1926        /* On the last dealloc, make this a regular file in case we crash.
1927           (We don't want to free these blocks a second time.)  */
1928        if (last_dealloc)
1929                dip->i_inode.i_mode = S_IFREG;
1930        gfs2_dinode_out(dip, dibh->b_data);
1931        brelse(dibh);
1932
1933out_end_trans:
1934        gfs2_trans_end(sdp);
1935out_rg_gunlock:
1936        gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
1937out_rlist:
1938        gfs2_rlist_free(&rlist);
1939        gfs2_quota_unhold(dip);
1940out:
1941        kfree(ht);
1942        return error;
1943}
1944
1945/**
1946 * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory
1947 * @dip: the directory
1948 *
1949 * Dealloc all on-disk directory leaves to FREEMETA state
1950 * Change on-disk inode type to "regular file"
1951 *
1952 * Returns: errno
1953 */
1954
1955int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip)
1956{
1957        struct buffer_head *bh;
1958        struct gfs2_leaf *leaf;
1959        u32 hsize, len;
1960        u32 index = 0, next_index;
1961        __be64 *lp;
1962        u64 leaf_no;
1963        int error = 0, last;
1964
1965        hsize = 1 << dip->i_depth;
1966
1967        lp = gfs2_dir_get_hash_table(dip);
1968        if (IS_ERR(lp))
1969                return PTR_ERR(lp);
1970
1971        while (index < hsize) {
1972                leaf_no = be64_to_cpu(lp[index]);
1973                if (leaf_no) {
1974                        error = get_leaf(dip, leaf_no, &bh);
1975                        if (error)
1976                                goto out;
1977                        leaf = (struct gfs2_leaf *)bh->b_data;
1978                        len = 1 << (dip->i_depth - be16_to_cpu(leaf->lf_depth));
1979
1980                        next_index = (index & ~(len - 1)) + len;
1981                        last = ((next_index >= hsize) ? 1 : 0);
1982                        error = leaf_dealloc(dip, index, len, leaf_no, bh,
1983                                             last);
1984                        brelse(bh);
1985                        if (error)
1986                                goto out;
1987                        index = next_index;
1988                } else
1989                        index++;
1990        }
1991
1992        if (index != hsize) {
1993                gfs2_consist_inode(dip);
1994                error = -EIO;
1995        }
1996
1997out:
1998
1999        return error;
2000}
2001
2002/**
2003 * gfs2_diradd_alloc_required - find if adding entry will require an allocation
2004 * @ip: the file being written to
2005 * @filname: the filename that's going to be added
2006 *
2007 * Returns: 1 if alloc required, 0 if not, -ve on error
2008 */
2009
2010int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name)
2011{
2012        struct gfs2_dirent *dent;
2013        struct buffer_head *bh;
2014
2015        dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
2016        if (!dent) {
2017                return 1;
2018        }
2019        if (IS_ERR(dent))
2020                return PTR_ERR(dent);
2021        brelse(bh);
2022        return 0;
2023}
2024
2025
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