lustre/lvfs/fsfilt_ext3.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/lvfs/fsfilt_ext3.c
  37  *
  38  * Author: Andreas Dilger <adilger@clusterfs.com>
  39  */
  40
  41 #define DEBUG_SUBSYSTEM S_FILTER
  42
  43 #include <linux/init.h>
  44 #include <linux/module.h>
  45 #include <linux/fs.h>
  46 #include <linux/slab.h>
  47 #include <linux/pagemap.h>
  48 #include <ext4/ext4.h>
  49 #include <ext4/ext4_jbd2.h>
  50 #include <linux/version.h>
  51 #include <linux/bitops.h>
  52 #include <linux/quota.h>
  53
  54 #include <libcfs/libcfs.h>
  55 #include <lustre_fsfilt.h>
  56 #include <obd.h>
  57 #include <linux/lustre_compat25.h>
  58 #include <linux/lprocfs_status.h>
  59
  60 #include <ext4/ext4_extents.h>
  61
  62 /* for kernels 2.6.18 and later */
  63 #define FSFILT_SINGLEDATA_TRANS_BLOCKS(sb) EXT3_SINGLEDATA_TRANS_BLOCKS(sb)
  64
  65 #define fsfilt_ext3_ext_insert_extent(handle, inode, path, newext, flag) \
  66                ext3_ext_insert_extent(handle, inode, path, newext, flag)
  67
  68 #define ext3_mb_discard_inode_preallocations(inode) \
  69                  ext3_discard_preallocations(inode)
  70
  71 #define fsfilt_log_start_commit(journal, tid) jbd2_log_start_commit(journal, tid)
  72 #define fsfilt_log_wait_commit(journal, tid) jbd2_log_wait_commit(journal, tid)
  73
  74 static cfs_mem_cache_t *fcb_cache;
  75
  76 struct fsfilt_cb_data {
  77         struct ext4_journal_cb_entry cb_jcb; /* private data - MUST BE FIRST */
  78         fsfilt_cb_t cb_func;            /* MDS/OBD completion function */
  79         struct obd_device *cb_obd;      /* MDS/OBD completion device */
  80         __u64 cb_last_rcvd;             /* MDS/OST last committed operation */
  81         void *cb_data;                  /* MDS/OST completion function data */
  82 };
  83
  84 static char *fsfilt_ext3_get_label(struct super_block *sb)
  85 {
  86         return EXT3_SB(sb)->s_es->s_volume_name;
  87 }
  88
  89 /* kernel has ext4_blocks_for_truncate since linux-3.1.1 */
  90 #ifdef HAVE_BLOCKS_FOR_TRUNCATE
  91 # include <ext4/truncate.h>
  92 #else
  93 static inline unsigned long ext4_blocks_for_truncate(struct inode *inode)
  94 {
  95         ext4_lblk_t needed;
  96
  97         needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
  98         if (needed < 2)
  99                 needed = 2;
 100         if (needed > EXT4_MAX_TRANS_DATA)
 101                 needed = EXT4_MAX_TRANS_DATA;
 102         return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
 103 }
 104 #endif
 105
 106 /*
 107  * We don't currently need any additional blocks for rmdir and
 108  * unlink transactions because we are storing the OST oa_id inside
 109  * the inode (which we will be changing anyways as part of this
 110  * transaction).
 111  */
 112 static void *fsfilt_ext3_start(struct inode *inode, int op, void *desc_private,
 113                                int logs)
 114 {
 115         /* For updates to the last received file */
 116         int nblocks = FSFILT_SINGLEDATA_TRANS_BLOCKS(inode->i_sb);
 117         journal_t *journal;
 118         void *handle;
 119
 120         if (current->journal_info) {
 121                 CDEBUG(D_INODE, "increasing refcount on %p\n",
 122                        current->journal_info);
 123                 goto journal_start;
 124         }
 125
 126         switch(op) {
 127         case FSFILT_OP_UNLINK:
 128                 /* delete one file + create/update logs for each stripe */
 129                 nblocks += EXT3_DELETE_TRANS_BLOCKS(inode->i_sb);
 130                 nblocks += (EXT3_INDEX_EXTRA_TRANS_BLOCKS +
 131                             FSFILT_SINGLEDATA_TRANS_BLOCKS(inode->i_sb)) * logs;
 132                 break;
 133         case FSFILT_OP_CANCEL_UNLINK:
 134                 LASSERT(logs == 1);
 135
 136                 /* blocks for log header bitmap update OR
 137                  * blocks for catalog header bitmap update + unlink of logs +
 138                  * blocks for delete the inode (include blocks truncating). */
 139                 nblocks = (LLOG_CHUNK_SIZE >> inode->i_blkbits) +
 140                           EXT3_DELETE_TRANS_BLOCKS(inode->i_sb) +
 141                           ext4_blocks_for_truncate(inode) + 3;
 142                 break;
 143         default: CERROR("unknown transaction start op %d\n", op);
 144                 LBUG();
 145         }
 146
 147         LASSERT(current->journal_info == desc_private);
 148         journal = EXT3_SB(inode->i_sb)->s_journal;
 149         if (nblocks > journal->j_max_transaction_buffers) {
 150                 CWARN("too many credits %d for op %ux%u using %d instead\n",
 151                        nblocks, op, logs, journal->j_max_transaction_buffers);
 152                 nblocks = journal->j_max_transaction_buffers;
 153         }
 154
 155  journal_start:
 156         LASSERTF(nblocks > 0, "can't start %d credit transaction\n", nblocks);
 157         handle = ext3_journal_start(inode, nblocks);
 158
 159         if (!IS_ERR(handle))
 160                 LASSERT(current->journal_info == handle);
 161         else
 162                 CERROR("error starting handle for op %u (%u credits): rc %ld\n",
 163                        op, nblocks, PTR_ERR(handle));
 164         return handle;
 165 }
 166
 167 static int fsfilt_ext3_commit(struct inode *inode, void *h, int force_sync)
 168 {
 169         int rc;
 170         handle_t *handle = h;
 171
 172         LASSERT(current->journal_info == handle);
 173         if (force_sync)
 174                 handle->h_sync = 1; /* recovery likes this */
 175
 176         rc = ext3_journal_stop(handle);
 177
 178         return rc;
 179 }
 180
 181 #ifndef EXT3_EXTENTS_FL
 182 #define EXT3_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 183 #endif
 184
 185 #ifndef EXT_ASSERT
 186 #define EXT_ASSERT(cond)  BUG_ON(!(cond))
 187 #endif
 188
 189 #define EXT_GENERATION(inode)           (EXT4_I(inode)->i_ext_generation)
 190 #define ext3_ext_base                   inode
 191 #define ext3_ext_base2inode(inode)      (inode)
 192 #define EXT_DEPTH(inode)                ext_depth(inode)
 193 #define fsfilt_ext3_ext_walk_space(inode, block, num, cb, cbdata) \
 194                         ext3_ext_walk_space(inode, block, num, cb, cbdata);
 195
 196 struct bpointers {
 197         unsigned long *blocks;
 198         int *created;
 199         unsigned long start;
 200         int num;
 201         int init_num;
 202         int create;
 203 };
 204
 205 static long ext3_ext_find_goal(struct inode *inode, struct ext3_ext_path *path,
 206                                unsigned long block, int *aflags)
 207 {
 208         struct ext3_inode_info *ei = EXT3_I(inode);
 209         unsigned long bg_start;
 210         unsigned long colour;
 211         int depth;
 212
 213         if (path) {
 214                 struct ext3_extent *ex;
 215                 depth = path->p_depth;
 216
 217                 /* try to predict block placement */
 218                 if ((ex = path[depth].p_ext))
 219                         return ext_pblock(ex) + (block - le32_to_cpu(ex->ee_block));
 220
 221                 /* it looks index is empty
 222                  * try to find starting from index itself */
 223                 if (path[depth].p_bh)
 224                         return path[depth].p_bh->b_blocknr;
 225         }
 226
 227         /* OK. use inode's group */
 228         bg_start = (ei->i_block_group * EXT3_BLOCKS_PER_GROUP(inode->i_sb)) +
 229                 le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block);
 230         colour = (current->pid % 16) *
 231                 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
 232         return bg_start + colour + block;
 233 }
 234
 235 #define ll_unmap_underlying_metadata(sb, blocknr) \
 236         unmap_underlying_metadata((sb)->s_bdev, blocknr)
 237
 238 #ifndef EXT3_MB_HINT_GROUP_ALLOC
 239 static unsigned long new_blocks(handle_t *handle, struct ext3_ext_base *base,
 240                                 struct ext3_ext_path *path, unsigned long block,
 241                                 unsigned long *count, int *err)
 242 {
 243         unsigned long pblock, goal;
 244         int aflags = 0;
 245         struct inode *inode = ext3_ext_base2inode(base);
 246
 247         goal = ext3_ext_find_goal(inode, path, block, &aflags);
 248         aflags |= 2; /* block have been already reserved */
 249         pblock = ext3_mb_new_blocks(handle, inode, goal, count, aflags, err);
 250         return pblock;
 251
 252 }
 253 #else
 254 static unsigned long new_blocks(handle_t *handle, struct ext3_ext_base *base,
 255                                 struct ext3_ext_path *path, unsigned long block,
 256                                 unsigned long *count, int *err)
 257 {
 258         struct inode *inode = ext3_ext_base2inode(base);
 259         struct ext3_allocation_request ar;
 260         unsigned long pblock;
 261         int aflags;
 262
 263         /* find neighbour allocated blocks */
 264         ar.lleft = block;
 265         *err = ext3_ext_search_left(base, path, &ar.lleft, &ar.pleft);
 266         if (*err)
 267                 return 0;
 268         ar.lright = block;
 269         *err = ext3_ext_search_right(base, path, &ar.lright, &ar.pright);
 270         if (*err)
 271                 return 0;
 272
 273         /* allocate new block */
 274         ar.goal = ext3_ext_find_goal(inode, path, block, &aflags);
 275         ar.inode = inode;
 276         ar.logical = block;
 277         ar.len = *count;
 278         ar.flags = EXT3_MB_HINT_DATA;
 279         pblock = ext3_mb_new_blocks(handle, &ar, err);
 280         *count = ar.len;
 281         return pblock;
 282 }
 283 #endif
 284
 285 static int ext3_ext_new_extent_cb(struct ext3_ext_base *base,
 286                                   struct ext3_ext_path *path,
 287                                   struct ext3_ext_cache *cex,
 288 #ifdef HAVE_EXT_PREPARE_CB_EXTENT
 289                                    struct ext3_extent *ex,
 290 #endif
 291                                   void *cbdata)
 292 {
 293         struct bpointers *bp = cbdata;
 294         struct inode *inode = ext3_ext_base2inode(base);
 295         struct ext3_extent nex;
 296         unsigned long pblock;
 297         unsigned long tgen;
 298         int err, i;
 299         unsigned long count;
 300         handle_t *handle;
 301
 302         if (cex->ec_type == EXT3_EXT_CACHE_EXTENT) {
 303                 err = EXT_CONTINUE;
 304                 goto map;
 305         }
 306
 307         if (bp->create == 0) {
 308                 i = 0;
 309                 if (cex->ec_block < bp->start)
 310                         i = bp->start - cex->ec_block;
 311                 if (i >= cex->ec_len)
 312                         CERROR("nothing to do?! i = %d, e_num = %u\n",
 313                                         i, cex->ec_len);
 314                 for (; i < cex->ec_len && bp->num; i++) {
 315                         *(bp->created) = 0;
 316                         bp->created++;
 317                         *(bp->blocks) = 0;
 318                         bp->blocks++;
 319                         bp->num--;
 320                         bp->start++;
 321                 }
 322
 323                 return EXT_CONTINUE;
 324         }
 325
 326         tgen = EXT_GENERATION(base);
 327         count = ext3_ext_calc_credits_for_insert(base, path);
 328
 329         handle = ext3_journal_start(inode, count+EXT3_ALLOC_NEEDED+1);
 330         if (IS_ERR(handle)) {
 331                 return PTR_ERR(handle);
 332         }
 333
 334         if (tgen != EXT_GENERATION(base)) {
 335                 /* the tree has changed. so path can be invalid at moment */
 336                 ext3_journal_stop(handle);
 337                 return EXT_REPEAT;
 338         }
 339
 340         /* In 2.6.32 kernel, ext4_ext_walk_space()'s callback func is not
 341          * protected by i_data_sem as whole. so we patch it to store
 342          * generation to path and now verify the tree hasn't changed */
 343         down_write((&EXT4_I(inode)->i_data_sem));
 344
 345         /* validate extent, make sure the extent tree does not changed */
 346         if (EXT_GENERATION(base) != path[0].p_generation) {
 347                 /* cex is invalid, try again */
 348                 up_write(&EXT4_I(inode)->i_data_sem);
 349                 ext3_journal_stop(handle);
 350                 return EXT_REPEAT;
 351         }
 352
 353         count = cex->ec_len;
 354         pblock = new_blocks(handle, base, path, cex->ec_block, &count, &err);
 355         if (!pblock)
 356                 goto out;
 357         EXT_ASSERT(count <= cex->ec_len);
 358
 359         /* insert new extent */
 360         nex.ee_block = cpu_to_le32(cex->ec_block);
 361         ext3_ext_store_pblock(&nex, pblock);
 362         nex.ee_len = cpu_to_le16(count);
 363         err = fsfilt_ext3_ext_insert_extent(handle, base, path, &nex, 0);
 364         if (err) {
 365                 /* free data blocks we just allocated */
 366                 /* not a good idea to call discard here directly,
 367                  * but otherwise we'd need to call it every free() */
 368 #ifdef EXT3_MB_HINT_GROUP_ALLOC
 369                 ext3_mb_discard_inode_preallocations(inode);
 370 #endif
 371                 ext3_free_blocks(handle, inode, ext_pblock(&nex),
 372                                  cpu_to_le16(nex.ee_len), 0);
 373                 goto out;
 374         }
 375
 376         /*
 377          * Putting len of the actual extent we just inserted,
 378          * we are asking ext3_ext_walk_space() to continue
 379          * scaning after that block
 380          */
 381         cex->ec_len = le16_to_cpu(nex.ee_len);
 382         cex->ec_start = ext_pblock(&nex);
 383         BUG_ON(le16_to_cpu(nex.ee_len) == 0);
 384         BUG_ON(le32_to_cpu(nex.ee_block) != cex->ec_block);
 385
 386 out:
 387         up_write((&EXT4_I(inode)->i_data_sem));
 388         ext3_journal_stop(handle);
 389 map:
 390         if (err >= 0) {
 391                 /* map blocks */
 392                 if (bp->num == 0) {
 393                         CERROR("hmm. why do we find this extent?\n");
 394                         CERROR("initial space: %lu:%u\n",
 395                                 bp->start, bp->init_num);
 396                         CERROR("current extent: %u/%u/%llu %d\n",
 397                                 cex->ec_block, cex->ec_len,
 398                                 (unsigned long long)cex->ec_start,
 399                                 cex->ec_type);
 400                 }
 401                 i = 0;
 402                 if (cex->ec_block < bp->start)
 403                         i = bp->start - cex->ec_block;
 404                 if (i >= cex->ec_len)
 405                         CERROR("nothing to do?! i = %d, e_num = %u\n",
 406                                         i, cex->ec_len);
 407                 for (; i < cex->ec_len && bp->num; i++) {
 408                         *(bp->blocks) = cex->ec_start + i;
 409                         if (cex->ec_type == EXT3_EXT_CACHE_EXTENT) {
 410                                 *(bp->created) = 0;
 411                         } else {
 412                                 *(bp->created) = 1;
 413                                 /* unmap any possible underlying metadata from
 414                                  * the block device mapping.  bug 6998. */
 415                                 ll_unmap_underlying_metadata(inode->i_sb,
 416                                                              *(bp->blocks));
 417                         }
 418                         bp->created++;
 419                         bp->blocks++;
 420                         bp->num--;
 421                         bp->start++;
 422                 }
 423         }
 424         return err;
 425 }
 426
 427 int fsfilt_map_nblocks(struct inode *inode, unsigned long block,
 428                        unsigned long num, unsigned long *blocks,
 429                        int *created, int create)
 430 {
 431         struct ext3_ext_base *base = inode;
 432         struct bpointers bp;
 433         int err;
 434
 435         CDEBUG(D_OTHER, "blocks %lu-%lu requested for inode %u\n",
 436                block, block + num - 1, (unsigned) inode->i_ino);
 437
 438         bp.blocks = blocks;
 439         bp.created = created;
 440         bp.start = block;
 441         bp.init_num = bp.num = num;
 442         bp.create = create;
 443
 444         err = fsfilt_ext3_ext_walk_space(base, block, num,
 445                                          ext3_ext_new_extent_cb, &bp);
 446         ext3_ext_invalidate_cache(base);
 447
 448         return err;
 449 }
 450
 451 int fsfilt_ext3_map_ext_inode_pages(struct inode *inode, struct page **page,
 452                                     int pages, unsigned long *blocks,
 453                                     int *created, int create)
 454 {
 455         int blocks_per_page = CFS_PAGE_SIZE >> inode->i_blkbits;
 456         int rc = 0, i = 0;
 457         struct page *fp = NULL;
 458         int clen = 0;
 459
 460         CDEBUG(D_OTHER, "inode %lu: map %d pages from %lu\n",
 461                 inode->i_ino, pages, (*page)->index);
 462
 463         /* pages are sorted already. so, we just have to find
 464          * contig. space and process them properly */
 465         while (i < pages) {
 466                 if (fp == NULL) {
 467                         /* start new extent */
 468                         fp = *page++;
 469                         clen = 1;
 470                         i++;
 471                         continue;
 472                 } else if (fp->index + clen == (*page)->index) {
 473                         /* continue the extent */
 474                         page++;
 475                         clen++;
 476                         i++;
 477                         continue;
 478                 }
 479
 480                 /* process found extent */
 481                 rc = fsfilt_map_nblocks(inode, fp->index * blocks_per_page,
 482                                         clen * blocks_per_page, blocks,
 483                                         created, create);
 484                 if (rc)
 485                         GOTO(cleanup, rc);
 486
 487                 /* look for next extent */
 488                 fp = NULL;
 489                 blocks += blocks_per_page * clen;
 490                 created += blocks_per_page * clen;
 491         }
 492
 493         if (fp)
 494                 rc = fsfilt_map_nblocks(inode, fp->index * blocks_per_page,
 495                                         clen * blocks_per_page, blocks,
 496                                         created, create);
 497 cleanup:
 498         return rc;
 499 }
 500
 501 extern int ext3_map_inode_page(struct inode *inode, struct page *page,
 502                                unsigned long *blocks, int *created, int create);
 503 int fsfilt_ext3_map_bm_inode_pages(struct inode *inode, struct page **page,
 504                                    int pages, unsigned long *blocks,
 505                                    int *created, int create)
 506 {
 507         int blocks_per_page = CFS_PAGE_SIZE >> inode->i_blkbits;
 508         unsigned long *b;
 509         int rc = 0, i, *cr;
 510
 511         for (i = 0, cr = created, b = blocks; i < pages; i++, page++) {
 512                 rc = ext3_map_inode_page(inode, *page, b, cr, create);
 513                 if (rc) {
 514                         CERROR("ino %lu, blk %lu cr %u create %d: rc %d\n",
 515                                inode->i_ino, *b, *cr, create, rc);
 516                         break;
 517                 }
 518
 519                 b += blocks_per_page;
 520                 cr += blocks_per_page;
 521         }
 522         return rc;
 523 }
 524
 525 int fsfilt_ext3_map_inode_pages(struct inode *inode, struct page **page,
 526                                 int pages, unsigned long *blocks,
 527                                 int *created, int create,
 528                                 struct mutex *optional_mutex)
 529 {
 530         int rc;
 531
 532         if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL) {
 533                 rc = fsfilt_ext3_map_ext_inode_pages(inode, page, pages,
 534                                                      blocks, created, create);
 535                 return rc;
 536         }
 537         if (optional_mutex != NULL)
 538                 mutex_lock(optional_mutex);
 539         rc = fsfilt_ext3_map_bm_inode_pages(inode, page, pages, blocks,
 540                                             created, create);
 541         if (optional_mutex != NULL)
 542                 mutex_unlock(optional_mutex);
 543
 544         return rc;
 545 }
 546
 547 int fsfilt_ext3_read(struct inode *inode, void *buf, int size, loff_t *offs)
 548 {
 549         unsigned long block;
 550         struct buffer_head *bh;
 551         int err, blocksize, csize, boffs, osize = size;
 552
 553         /* prevent reading after eof */
 554         spin_lock(&inode->i_lock);
 555         if (i_size_read(inode) < *offs + size) {
 556                 size = i_size_read(inode) - *offs;
 557                 spin_unlock(&inode->i_lock);
 558                 if (size < 0) {
 559                         CDEBUG(D_EXT2, "size %llu is too short for read @%llu\n",
 560                                i_size_read(inode), *offs);
 561                         return -EBADR;
 562                 } else if (size == 0) {
 563                         return 0;
 564                 }
 565         } else {
 566                 spin_unlock(&inode->i_lock);
 567         }
 568
 569         blocksize = 1 << inode->i_blkbits;
 570
 571         while (size > 0) {
 572                 block = *offs >> inode->i_blkbits;
 573                 boffs = *offs & (blocksize - 1);
 574                 csize = min(blocksize - boffs, size);
 575                 bh = ext3_bread(NULL, inode, block, 0, &err);
 576                 if (!bh) {
 577                         CERROR("can't read block: %d\n", err);
 578                         return err;
 579                 }
 580
 581                 memcpy(buf, bh->b_data + boffs, csize);
 582                 brelse(bh);
 583
 584                 *offs += csize;
 585                 buf += csize;
 586                 size -= csize;
 587         }
 588         return osize;
 589 }
 590 EXPORT_SYMBOL(fsfilt_ext3_read);
 591
 592 static int fsfilt_ext3_read_record(struct file * file, void *buf,
 593                                    int size, loff_t *offs)
 594 {
 595         int rc;
 596         rc = fsfilt_ext3_read(file->f_dentry->d_inode, buf, size, offs);
 597         if (rc > 0)
 598                 rc = 0;
 599         return rc;
 600 }
 601
 602 int fsfilt_ext3_write_handle(struct inode *inode, void *buf, int bufsize,
 603                                 loff_t *offs, handle_t *handle)
 604 {
 605         struct buffer_head *bh = NULL;
 606         loff_t old_size = i_size_read(inode), offset = *offs;
 607         loff_t new_size = i_size_read(inode);
 608         unsigned long block;
 609         int err = 0, blocksize = 1 << inode->i_blkbits, size, boffs;
 610
 611         while (bufsize > 0) {
 612                 if (bh != NULL)
 613                         brelse(bh);
 614
 615                 block = offset >> inode->i_blkbits;
 616                 boffs = offset & (blocksize - 1);
 617                 size = min(blocksize - boffs, bufsize);
 618                 bh = ext3_bread(handle, inode, block, 1, &err);
 619                 if (!bh) {
 620                         CERROR("can't read/create block: %d\n", err);
 621                         break;
 622                 }
 623
 624                 err = ext3_journal_get_write_access(handle, bh);
 625                 if (err) {
 626                         CERROR("journal_get_write_access() returned error %d\n",
 627                                err);
 628                         break;
 629                 }
 630                 LASSERT(bh->b_data + boffs + size <= bh->b_data + bh->b_size);
 631                 memcpy(bh->b_data + boffs, buf, size);
 632                 err = ext3_journal_dirty_metadata(handle, bh);
 633                 if (err) {
 634                         CERROR("journal_dirty_metadata() returned error %d\n",
 635                                err);
 636                         break;
 637                 }
 638                 if (offset + size > new_size)
 639                         new_size = offset + size;
 640                 offset += size;
 641                 bufsize -= size;
 642                 buf += size;
 643         }
 644         if (bh)
 645                 brelse(bh);
 646
 647         /* correct in-core and on-disk sizes */
 648         if (new_size > i_size_read(inode)) {
 649                 spin_lock(&inode->i_lock);
 650                 if (new_size > i_size_read(inode))
 651                         i_size_write(inode, new_size);
 652                 if (i_size_read(inode) > EXT3_I(inode)->i_disksize)
 653                         EXT3_I(inode)->i_disksize = i_size_read(inode);
 654                 if (i_size_read(inode) > old_size) {
 655                         spin_unlock(&inode->i_lock);
 656                         mark_inode_dirty(inode);
 657                 } else {
 658                         spin_unlock(&inode->i_lock);
 659                 }
 660         }
 661
 662         if (err == 0)
 663                 *offs = offset;
 664         return err;
 665 }
 666 EXPORT_SYMBOL(fsfilt_ext3_write_handle);
 667
 668 static int fsfilt_ext3_write_record(struct file *file, void *buf, int bufsize,
 669                                     loff_t *offs, int force_sync)
 670 {
 671         struct inode *inode = file->f_dentry->d_inode;
 672         handle_t *handle;
 673         int err, block_count = 0, blocksize;
 674
 675         /* Determine how many transaction credits are needed */
 676         blocksize = 1 << inode->i_blkbits;
 677         block_count = (*offs & (blocksize - 1)) + bufsize;
 678         block_count = (block_count + blocksize - 1) >> inode->i_blkbits;
 679
 680         handle = ext3_journal_start(inode,
 681                         block_count * EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + 2);
 682         if (IS_ERR(handle)) {
 683                 CERROR("can't start transaction for %d blocks (%d bytes)\n",
 684                        block_count * EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + 2,
 685                        bufsize);
 686                 return PTR_ERR(handle);
 687         }
 688
 689         err = fsfilt_ext3_write_handle(inode, buf, bufsize, offs, handle);
 690
 691         if (!err && force_sync)
 692                 handle->h_sync = 1; /* recovery likes this */
 693
 694         ext3_journal_stop(handle);
 695
 696         return err;
 697 }
 698
 699 static int fsfilt_ext3_setup(struct super_block *sb)
 700 {
 701         if (!EXT3_HAS_COMPAT_FEATURE(sb,
 702                                 EXT3_FEATURE_COMPAT_HAS_JOURNAL)) {
 703                 CERROR("ext3 mounted without journal\n");
 704                 return -EINVAL;
 705         }
 706
 707 #ifdef S_PDIROPS
 708         CWARN("Enabling PDIROPS\n");
 709         set_opt(EXT3_SB(sb)->s_mount_opt, PDIROPS);
 710         sb->s_flags |= S_PDIROPS;
 711 #endif
 712         if (!EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_DIR_INDEX))
 713                 CWARN("filesystem doesn't have dir_index feature enabled\n");
 714         return 0;
 715 }
 716 static struct fsfilt_operations fsfilt_ext3_ops = {
 717         .fs_type                = "ext3",
 718         .fs_owner               = THIS_MODULE,
 719         .fs_getlabel            = fsfilt_ext3_get_label,
 720         .fs_start               = fsfilt_ext3_start,
 721         .fs_commit              = fsfilt_ext3_commit,
 722         .fs_map_inode_pages     = fsfilt_ext3_map_inode_pages,
 723         .fs_write_record        = fsfilt_ext3_write_record,
 724         .fs_read_record         = fsfilt_ext3_read_record,
 725         .fs_setup               = fsfilt_ext3_setup,
 726 };
 727
 728 static int __init fsfilt_ext3_init(void)
 729 {
 730         int rc;
 731
 732         fcb_cache = cfs_mem_cache_create("fsfilt_ext3_fcb",
 733                                          sizeof(struct fsfilt_cb_data), 0, 0);
 734         if (!fcb_cache) {
 735                 CERROR("error allocating fsfilt journal callback cache\n");
 736                 GOTO(out, rc = -ENOMEM);
 737         }
 738
 739         rc = fsfilt_register_ops(&fsfilt_ext3_ops);
 740
 741         if (rc) {
 742                 int err = cfs_mem_cache_destroy(fcb_cache);
 743                 LASSERTF(err == 0, "error destroying new cache: rc %d\n", err);
 744         }
 745 out:
 746         return rc;
 747 }
 748
 749 static void __exit fsfilt_ext3_exit(void)
 750 {
 751         int rc;
 752
 753         fsfilt_unregister_ops(&fsfilt_ext3_ops);
 754         rc = cfs_mem_cache_destroy(fcb_cache);
 755         LASSERTF(rc == 0, "couldn't destroy fcb_cache slab\n");
 756 }
 757
 758 module_init(fsfilt_ext3_init);
 759 module_exit(fsfilt_ext3_exit);
 760
 761 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 762 MODULE_DESCRIPTION("Lustre ext3 Filesystem Helper v0.1");
 763 MODULE_LICENSE("GPL");