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 #ifdef EXT3_EXT_CACHE_EXTENT
 303         if (cex->ec_type == EXT3_EXT_CACHE_EXTENT)
 304 #else
 305         if ((cex->ec_len != 0) && (cex->ec_start != 0))
 306 #endif
 307                                                    {
 308                 err = EXT_CONTINUE;
 309                 goto map;
 310         }
 311
 312         if (bp->create == 0) {
 313                 i = 0;
 314                 if (cex->ec_block < bp->start)
 315                         i = bp->start - cex->ec_block;
 316                 if (i >= cex->ec_len)
 317                         CERROR("nothing to do?! i = %d, e_num = %u\n",
 318                                         i, cex->ec_len);
 319                 for (; i < cex->ec_len && bp->num; i++) {
 320                         *(bp->created) = 0;
 321                         bp->created++;
 322                         *(bp->blocks) = 0;
 323                         bp->blocks++;
 324                         bp->num--;
 325                         bp->start++;
 326                 }
 327
 328                 return EXT_CONTINUE;
 329         }
 330
 331         tgen = EXT_GENERATION(base);
 332         count = ext3_ext_calc_credits_for_insert(base, path);
 333
 334         handle = ext3_journal_start(inode, count+EXT3_ALLOC_NEEDED+1);
 335         if (IS_ERR(handle)) {
 336                 return PTR_ERR(handle);
 337         }
 338
 339         if (tgen != EXT_GENERATION(base)) {
 340                 /* the tree has changed. so path can be invalid at moment */
 341                 ext3_journal_stop(handle);
 342                 return EXT_REPEAT;
 343         }
 344
 345         /* In 2.6.32 kernel, ext4_ext_walk_space()'s callback func is not
 346          * protected by i_data_sem as whole. so we patch it to store
 347          * generation to path and now verify the tree hasn't changed */
 348         down_write((&EXT4_I(inode)->i_data_sem));
 349
 350         /* validate extent, make sure the extent tree does not changed */
 351         if (EXT_GENERATION(base) != path[0].p_generation) {
 352                 /* cex is invalid, try again */
 353                 up_write(&EXT4_I(inode)->i_data_sem);
 354                 ext3_journal_stop(handle);
 355                 return EXT_REPEAT;
 356         }
 357
 358         count = cex->ec_len;
 359         pblock = new_blocks(handle, base, path, cex->ec_block, &count, &err);
 360         if (!pblock)
 361                 goto out;
 362         EXT_ASSERT(count <= cex->ec_len);
 363
 364         /* insert new extent */
 365         nex.ee_block = cpu_to_le32(cex->ec_block);
 366         ext3_ext_store_pblock(&nex, pblock);
 367         nex.ee_len = cpu_to_le16(count);
 368         err = fsfilt_ext3_ext_insert_extent(handle, base, path, &nex, 0);
 369         if (err) {
 370                 /* free data blocks we just allocated */
 371                 /* not a good idea to call discard here directly,
 372                  * but otherwise we'd need to call it every free() */
 373 #ifdef EXT3_MB_HINT_GROUP_ALLOC
 374                 ext3_mb_discard_inode_preallocations(inode);
 375 #endif
 376                 ext3_free_blocks(handle, inode, ext_pblock(&nex),
 377                                  cpu_to_le16(nex.ee_len), 0);
 378                 goto out;
 379         }
 380
 381         /*
 382          * Putting len of the actual extent we just inserted,
 383          * we are asking ext3_ext_walk_space() to continue
 384          * scaning after that block
 385          */
 386         cex->ec_len = le16_to_cpu(nex.ee_len);
 387         cex->ec_start = ext_pblock(&nex);
 388         BUG_ON(le16_to_cpu(nex.ee_len) == 0);
 389         BUG_ON(le32_to_cpu(nex.ee_block) != cex->ec_block);
 390
 391 out:
 392         up_write((&EXT4_I(inode)->i_data_sem));
 393         ext3_journal_stop(handle);
 394 map:
 395         if (err >= 0) {
 396                 /* map blocks */
 397                 if (bp->num == 0) {
 398                         CERROR("hmm. why do we find this extent?\n");
 399                         CERROR("initial space: %lu:%u\n",
 400                                 bp->start, bp->init_num);
 401 #ifdef EXT3_EXT_CACHE_EXTENT
 402                         CERROR("current extent: %u/%u/%llu %d\n",
 403                                 cex->ec_block, cex->ec_len,
 404                                 (unsigned long long)cex->ec_start,
 405                                 cex->ec_type);
 406 #else
 407                         CERROR("current extent: %u/%u/%llu\n",
 408                                 cex->ec_block, cex->ec_len,
 409                                 (unsigned long long)cex->ec_start);
 410 #endif
 411                 }
 412                 i = 0;
 413                 if (cex->ec_block < bp->start)
 414                         i = bp->start - cex->ec_block;
 415                 if (i >= cex->ec_len)
 416                         CERROR("nothing to do?! i = %d, e_num = %u\n",
 417                                         i, cex->ec_len);
 418                 for (; i < cex->ec_len && bp->num; i++) {
 419                         *(bp->blocks) = cex->ec_start + i;
 420 #ifdef EXT3_EXT_CACHE_EXTENT
 421                         if (cex->ec_type == EXT3_EXT_CACHE_EXTENT)
 422 #else
 423                         if ((cex->ec_len != 0) && (cex->ec_start != 0))
 424 #endif
 425                                                                    {
 426                                 *(bp->created) = 0;
 427                         } else {
 428                                 *(bp->created) = 1;
 429                                 /* unmap any possible underlying metadata from
 430                                  * the block device mapping.  bug 6998. */
 431                                 ll_unmap_underlying_metadata(inode->i_sb,
 432                                                              *(bp->blocks));
 433                         }
 434                         bp->created++;
 435                         bp->blocks++;
 436                         bp->num--;
 437                         bp->start++;
 438                 }
 439         }
 440         return err;
 441 }
 442
 443 int fsfilt_map_nblocks(struct inode *inode, unsigned long block,
 444                        unsigned long num, unsigned long *blocks,
 445                        int *created, int create)
 446 {
 447         struct ext3_ext_base *base = inode;
 448         struct bpointers bp;
 449         int err;
 450
 451         CDEBUG(D_OTHER, "blocks %lu-%lu requested for inode %u\n",
 452                block, block + num - 1, (unsigned) inode->i_ino);
 453
 454         bp.blocks = blocks;
 455         bp.created = created;
 456         bp.start = block;
 457         bp.init_num = bp.num = num;
 458         bp.create = create;
 459
 460         err = fsfilt_ext3_ext_walk_space(base, block, num,
 461                                          ext3_ext_new_extent_cb, &bp);
 462         ext3_ext_invalidate_cache(base);
 463
 464         return err;
 465 }
 466
 467 int fsfilt_ext3_map_ext_inode_pages(struct inode *inode, struct page **page,
 468                                     int pages, unsigned long *blocks,
 469                                     int *created, int create)
 470 {
 471         int blocks_per_page = CFS_PAGE_SIZE >> inode->i_blkbits;
 472         int rc = 0, i = 0;
 473         struct page *fp = NULL;
 474         int clen = 0;
 475
 476         CDEBUG(D_OTHER, "inode %lu: map %d pages from %lu\n",
 477                 inode->i_ino, pages, (*page)->index);
 478
 479         /* pages are sorted already. so, we just have to find
 480          * contig. space and process them properly */
 481         while (i < pages) {
 482                 if (fp == NULL) {
 483                         /* start new extent */
 484                         fp = *page++;
 485                         clen = 1;
 486                         i++;
 487                         continue;
 488                 } else if (fp->index + clen == (*page)->index) {
 489                         /* continue the extent */
 490                         page++;
 491                         clen++;
 492                         i++;
 493                         continue;
 494                 }
 495
 496                 /* process found extent */
 497                 rc = fsfilt_map_nblocks(inode, fp->index * blocks_per_page,
 498                                         clen * blocks_per_page, blocks,
 499                                         created, create);
 500                 if (rc)
 501                         GOTO(cleanup, rc);
 502
 503                 /* look for next extent */
 504                 fp = NULL;
 505                 blocks += blocks_per_page * clen;
 506                 created += blocks_per_page * clen;
 507         }
 508
 509         if (fp)
 510                 rc = fsfilt_map_nblocks(inode, fp->index * blocks_per_page,
 511                                         clen * blocks_per_page, blocks,
 512                                         created, create);
 513 cleanup:
 514         return rc;
 515 }
 516
 517 extern int ext3_map_inode_page(struct inode *inode, struct page *page,
 518                                unsigned long *blocks, int *created, int create);
 519 int fsfilt_ext3_map_bm_inode_pages(struct inode *inode, struct page **page,
 520                                    int pages, unsigned long *blocks,
 521                                    int *created, int create)
 522 {
 523         int blocks_per_page = CFS_PAGE_SIZE >> inode->i_blkbits;
 524         unsigned long *b;
 525         int rc = 0, i, *cr;
 526
 527         for (i = 0, cr = created, b = blocks; i < pages; i++, page++) {
 528                 rc = ext3_map_inode_page(inode, *page, b, cr, create);
 529                 if (rc) {
 530                         CERROR("ino %lu, blk %lu cr %u create %d: rc %d\n",
 531                                inode->i_ino, *b, *cr, create, rc);
 532                         break;
 533                 }
 534
 535                 b += blocks_per_page;
 536                 cr += blocks_per_page;
 537         }
 538         return rc;
 539 }
 540
 541 int fsfilt_ext3_map_inode_pages(struct inode *inode, struct page **page,
 542                                 int pages, unsigned long *blocks,
 543                                 int *created, int create,
 544                                 struct mutex *optional_mutex)
 545 {
 546         int rc;
 547
 548         if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL) {
 549                 rc = fsfilt_ext3_map_ext_inode_pages(inode, page, pages,
 550                                                      blocks, created, create);
 551                 return rc;
 552         }
 553         if (optional_mutex != NULL)
 554                 mutex_lock(optional_mutex);
 555         rc = fsfilt_ext3_map_bm_inode_pages(inode, page, pages, blocks,
 556                                             created, create);
 557         if (optional_mutex != NULL)
 558                 mutex_unlock(optional_mutex);
 559
 560         return rc;
 561 }
 562
 563 int fsfilt_ext3_read(struct inode *inode, void *buf, int size, loff_t *offs)
 564 {
 565         unsigned long block;
 566         struct buffer_head *bh;
 567         int err, blocksize, csize, boffs, osize = size;
 568
 569         /* prevent reading after eof */
 570         spin_lock(&inode->i_lock);
 571         if (i_size_read(inode) < *offs + size) {
 572                 size = i_size_read(inode) - *offs;
 573                 spin_unlock(&inode->i_lock);
 574                 if (size < 0) {
 575                         CDEBUG(D_EXT2, "size %llu is too short for read @%llu\n",
 576                                i_size_read(inode), *offs);
 577                         return -EBADR;
 578                 } else if (size == 0) {
 579                         return 0;
 580                 }
 581         } else {
 582                 spin_unlock(&inode->i_lock);
 583         }
 584
 585         blocksize = 1 << inode->i_blkbits;
 586
 587         while (size > 0) {
 588                 block = *offs >> inode->i_blkbits;
 589                 boffs = *offs & (blocksize - 1);
 590                 csize = min(blocksize - boffs, size);
 591                 bh = ext3_bread(NULL, inode, block, 0, &err);
 592                 if (!bh) {
 593                         CERROR("can't read block: %d\n", err);
 594                         return err;
 595                 }
 596
 597                 memcpy(buf, bh->b_data + boffs, csize);
 598                 brelse(bh);
 599
 600                 *offs += csize;
 601                 buf += csize;
 602                 size -= csize;
 603         }
 604         return osize;
 605 }
 606 EXPORT_SYMBOL(fsfilt_ext3_read);
 607
 608 static int fsfilt_ext3_read_record(struct file * file, void *buf,
 609                                    int size, loff_t *offs)
 610 {
 611         int rc;
 612         rc = fsfilt_ext3_read(file->f_dentry->d_inode, buf, size, offs);
 613         if (rc > 0)
 614                 rc = 0;
 615         return rc;
 616 }
 617
 618 int fsfilt_ext3_write_handle(struct inode *inode, void *buf, int bufsize,
 619                                 loff_t *offs, handle_t *handle)
 620 {
 621         struct buffer_head *bh = NULL;
 622         loff_t old_size = i_size_read(inode), offset = *offs;
 623         loff_t new_size = i_size_read(inode);
 624         unsigned long block;
 625         int err = 0, blocksize = 1 << inode->i_blkbits, size, boffs;
 626
 627         while (bufsize > 0) {
 628                 if (bh != NULL)
 629                         brelse(bh);
 630
 631                 block = offset >> inode->i_blkbits;
 632                 boffs = offset & (blocksize - 1);
 633                 size = min(blocksize - boffs, bufsize);
 634                 bh = ext3_bread(handle, inode, block, 1, &err);
 635                 if (!bh) {
 636                         CERROR("can't read/create block: %d\n", err);
 637                         break;
 638                 }
 639
 640                 err = ext3_journal_get_write_access(handle, bh);
 641                 if (err) {
 642                         CERROR("journal_get_write_access() returned error %d\n",
 643                                err);
 644                         break;
 645                 }
 646                 LASSERT(bh->b_data + boffs + size <= bh->b_data + bh->b_size);
 647                 memcpy(bh->b_data + boffs, buf, size);
 648                 err = ext3_journal_dirty_metadata(handle, bh);
 649                 if (err) {
 650                         CERROR("journal_dirty_metadata() returned error %d\n",
 651                                err);
 652                         break;
 653                 }
 654                 if (offset + size > new_size)
 655                         new_size = offset + size;
 656                 offset += size;
 657                 bufsize -= size;
 658                 buf += size;
 659         }
 660         if (bh)
 661                 brelse(bh);
 662
 663         /* correct in-core and on-disk sizes */
 664         if (new_size > i_size_read(inode)) {
 665                 spin_lock(&inode->i_lock);
 666                 if (new_size > i_size_read(inode))
 667                         i_size_write(inode, new_size);
 668                 if (i_size_read(inode) > EXT3_I(inode)->i_disksize)
 669                         EXT3_I(inode)->i_disksize = i_size_read(inode);
 670                 if (i_size_read(inode) > old_size) {
 671                         spin_unlock(&inode->i_lock);
 672                         mark_inode_dirty(inode);
 673                 } else {
 674                         spin_unlock(&inode->i_lock);
 675                 }
 676         }
 677
 678         if (err == 0)
 679                 *offs = offset;
 680         return err;
 681 }
 682 EXPORT_SYMBOL(fsfilt_ext3_write_handle);
 683
 684 static int fsfilt_ext3_write_record(struct file *file, void *buf, int bufsize,
 685                                     loff_t *offs, int force_sync)
 686 {
 687         struct inode *inode = file->f_dentry->d_inode;
 688         handle_t *handle;
 689         int err, block_count = 0, blocksize;
 690
 691         /* Determine how many transaction credits are needed */
 692         blocksize = 1 << inode->i_blkbits;
 693         block_count = (*offs & (blocksize - 1)) + bufsize;
 694         block_count = (block_count + blocksize - 1) >> inode->i_blkbits;
 695
 696         handle = ext3_journal_start(inode,
 697                         block_count * EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + 2);
 698         if (IS_ERR(handle)) {
 699                 CERROR("can't start transaction for %d blocks (%d bytes)\n",
 700                        block_count * EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + 2,
 701                        bufsize);
 702                 return PTR_ERR(handle);
 703         }
 704
 705         err = fsfilt_ext3_write_handle(inode, buf, bufsize, offs, handle);
 706
 707         if (!err && force_sync)
 708                 handle->h_sync = 1; /* recovery likes this */
 709
 710         ext3_journal_stop(handle);
 711
 712         return err;
 713 }
 714
 715 static int fsfilt_ext3_setup(struct super_block *sb)
 716 {
 717         if (!EXT3_HAS_COMPAT_FEATURE(sb,
 718                                 EXT3_FEATURE_COMPAT_HAS_JOURNAL)) {
 719                 CERROR("ext3 mounted without journal\n");
 720                 return -EINVAL;
 721         }
 722
 723 #ifdef S_PDIROPS
 724         CWARN("Enabling PDIROPS\n");
 725         set_opt(EXT3_SB(sb)->s_mount_opt, PDIROPS);
 726         sb->s_flags |= S_PDIROPS;
 727 #endif
 728         if (!EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_DIR_INDEX))
 729                 CWARN("filesystem doesn't have dir_index feature enabled\n");
 730         return 0;
 731 }
 732 static struct fsfilt_operations fsfilt_ext3_ops = {
 733         .fs_type                = "ext3",
 734         .fs_owner               = THIS_MODULE,
 735         .fs_getlabel            = fsfilt_ext3_get_label,
 736         .fs_start               = fsfilt_ext3_start,
 737         .fs_commit              = fsfilt_ext3_commit,
 738         .fs_map_inode_pages     = fsfilt_ext3_map_inode_pages,
 739         .fs_write_record        = fsfilt_ext3_write_record,
 740         .fs_read_record         = fsfilt_ext3_read_record,
 741         .fs_setup               = fsfilt_ext3_setup,
 742 };
 743
 744 static int __init fsfilt_ext3_init(void)
 745 {
 746         int rc;
 747
 748         fcb_cache = cfs_mem_cache_create("fsfilt_ext3_fcb",
 749                                          sizeof(struct fsfilt_cb_data), 0, 0);
 750         if (!fcb_cache) {
 751                 CERROR("error allocating fsfilt journal callback cache\n");
 752                 GOTO(out, rc = -ENOMEM);
 753         }
 754
 755         rc = fsfilt_register_ops(&fsfilt_ext3_ops);
 756
 757         if (rc) {
 758                 int err = cfs_mem_cache_destroy(fcb_cache);
 759                 LASSERTF(err == 0, "error destroying new cache: rc %d\n", err);
 760         }
 761 out:
 762         return rc;
 763 }
 764
 765 static void __exit fsfilt_ext3_exit(void)
 766 {
 767         int rc;
 768
 769         fsfilt_unregister_ops(&fsfilt_ext3_ops);
 770         rc = cfs_mem_cache_destroy(fcb_cache);
 771         LASSERTF(rc == 0, "couldn't destroy fcb_cache slab\n");
 772 }
 773
 774 module_init(fsfilt_ext3_init);
 775 module_exit(fsfilt_ext3_exit);
 776
 777 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 778 MODULE_DESCRIPTION("Lustre ext3 Filesystem Helper v0.1");
 779 MODULE_LICENSE("GPL");