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, 2013, 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 #ifdef HAVE_EXT_PBLOCK /* Name changed to ext4_ext_pblock for kernel 2.6.35 */
  63 #define ext3_ext_pblock(ex) ext_pblock((ex))
  64 #endif
  65
  66 /* for kernels 2.6.18 and later */
  67 #define FSFILT_SINGLEDATA_TRANS_BLOCKS(sb) EXT3_SINGLEDATA_TRANS_BLOCKS(sb)
  68
  69 #define fsfilt_ext3_ext_insert_extent(handle, inode, path, newext, flag) \
  70                ext3_ext_insert_extent(handle, inode, path, newext, flag)
  71
  72 #define ext3_mb_discard_inode_preallocations(inode) \
  73                  ext3_discard_preallocations(inode)
  74
  75 #define fsfilt_log_start_commit(journal, tid) jbd2_log_start_commit(journal, tid)
  76 #define fsfilt_log_wait_commit(journal, tid) jbd2_log_wait_commit(journal, tid)
  77
  78 static struct kmem_cache *fcb_cache;
  79
  80 struct fsfilt_cb_data {
  81         struct ext4_journal_cb_entry cb_jcb; /* private data - MUST BE FIRST */
  82         fsfilt_cb_t cb_func;            /* MDS/OBD completion function */
  83         struct obd_device *cb_obd;      /* MDS/OBD completion device */
  84         __u64 cb_last_rcvd;             /* MDS/OST last committed operation */
  85         void *cb_data;                  /* MDS/OST completion function data */
  86 };
  87
  88 static char *fsfilt_ext3_get_label(struct super_block *sb)
  89 {
  90         return EXT3_SB(sb)->s_es->s_volume_name;
  91 }
  92
  93 /* kernel has ext4_blocks_for_truncate since linux-3.1.1 */
  94 #ifdef HAVE_BLOCKS_FOR_TRUNCATE
  95 # include <ext4/truncate.h>
  96 #else
  97 static inline unsigned long ext4_blocks_for_truncate(struct inode *inode)
  98 {
  99         ext4_lblk_t needed;
 100
 101         needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
 102         if (needed < 2)
 103                 needed = 2;
 104         if (needed > EXT4_MAX_TRANS_DATA)
 105                 needed = EXT4_MAX_TRANS_DATA;
 106         return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
 107 }
 108 #endif
 109
 110 /*
 111  * We don't currently need any additional blocks for rmdir and
 112  * unlink transactions because we are storing the OST oa_id inside
 113  * the inode (which we will be changing anyways as part of this
 114  * transaction).
 115  */
 116 static void *fsfilt_ext3_start(struct inode *inode, int op, void *desc_private,
 117                                int logs)
 118 {
 119         /* For updates to the last received file */
 120         int nblocks = FSFILT_SINGLEDATA_TRANS_BLOCKS(inode->i_sb);
 121         journal_t *journal;
 122         void *handle;
 123
 124         if (current->journal_info) {
 125                 CDEBUG(D_INODE, "increasing refcount on %p\n",
 126                        current->journal_info);
 127                 goto journal_start;
 128         }
 129
 130         switch(op) {
 131         case FSFILT_OP_UNLINK:
 132                 /* delete one file + create/update logs for each stripe */
 133                 nblocks += EXT3_DELETE_TRANS_BLOCKS(inode->i_sb);
 134                 nblocks += (EXT3_INDEX_EXTRA_TRANS_BLOCKS +
 135                             FSFILT_SINGLEDATA_TRANS_BLOCKS(inode->i_sb)) * logs;
 136                 break;
 137         case FSFILT_OP_CANCEL_UNLINK:
 138                 LASSERT(logs == 1);
 139
 140                 /* blocks for log header bitmap update OR
 141                  * blocks for catalog header bitmap update + unlink of logs +
 142                  * blocks for delete the inode (include blocks truncating). */
 143                 nblocks = (LLOG_CHUNK_SIZE >> inode->i_blkbits) +
 144                           EXT3_DELETE_TRANS_BLOCKS(inode->i_sb) +
 145                           ext4_blocks_for_truncate(inode) + 3;
 146                 break;
 147         default: CERROR("unknown transaction start op %d\n", op);
 148                 LBUG();
 149         }
 150
 151         LASSERT(current->journal_info == desc_private);
 152         journal = EXT3_SB(inode->i_sb)->s_journal;
 153         if (nblocks > journal->j_max_transaction_buffers) {
 154                 CWARN("too many credits %d for op %ux%u using %d instead\n",
 155                        nblocks, op, logs, journal->j_max_transaction_buffers);
 156                 nblocks = journal->j_max_transaction_buffers;
 157         }
 158
 159  journal_start:
 160         LASSERTF(nblocks > 0, "can't start %d credit transaction\n", nblocks);
 161         handle = ext3_journal_start(inode, nblocks);
 162
 163         if (!IS_ERR(handle))
 164                 LASSERT(current->journal_info == handle);
 165         else
 166                 CERROR("error starting handle for op %u (%u credits): rc %ld\n",
 167                        op, nblocks, PTR_ERR(handle));
 168         return handle;
 169 }
 170
 171 static int fsfilt_ext3_commit(struct inode *inode, void *h, int force_sync)
 172 {
 173         int rc;
 174         handle_t *handle = h;
 175
 176         LASSERT(current->journal_info == handle);
 177         if (force_sync)
 178                 handle->h_sync = 1; /* recovery likes this */
 179
 180         rc = ext3_journal_stop(handle);
 181
 182         return rc;
 183 }
 184
 185 #ifndef EXT3_EXTENTS_FL
 186 #define EXT3_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 187 #endif
 188
 189 #ifndef EXT_ASSERT
 190 #define EXT_ASSERT(cond)  BUG_ON(!(cond))
 191 #endif
 192
 193 #define EXT_GENERATION(inode)           (EXT4_I(inode)->i_ext_generation)
 194 #define ext3_ext_base                   inode
 195 #define ext3_ext_base2inode(inode)      (inode)
 196 #define EXT_DEPTH(inode)                ext_depth(inode)
 197 #define fsfilt_ext3_ext_walk_space(inode, block, num, cb, cbdata) \
 198                         ext3_ext_walk_space(inode, block, num, cb, cbdata);
 199
 200 struct bpointers {
 201         unsigned long *blocks;
 202         unsigned long start;
 203         int num;
 204         int init_num;
 205         int create;
 206 };
 207
 208 static long ext3_ext_find_goal(struct inode *inode, struct ext3_ext_path *path,
 209                                unsigned long block, int *aflags)
 210 {
 211         struct ext3_inode_info *ei = EXT3_I(inode);
 212         unsigned long bg_start;
 213         unsigned long colour;
 214         int depth;
 215
 216         if (path) {
 217                 struct ext3_extent *ex;
 218                 depth = path->p_depth;
 219
 220                 /* try to predict block placement */
 221                 if ((ex = path[depth].p_ext))
 222                         return ext4_ext_pblock(ex) + (block - le32_to_cpu(ex->ee_block));
 223
 224                 /* it looks index is empty
 225                  * try to find starting from index itself */
 226                 if (path[depth].p_bh)
 227                         return path[depth].p_bh->b_blocknr;
 228         }
 229
 230         /* OK. use inode's group */
 231         bg_start = (ei->i_block_group * EXT3_BLOCKS_PER_GROUP(inode->i_sb)) +
 232                 le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block);
 233         colour = (current->pid % 16) *
 234                 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
 235         return bg_start + colour + block;
 236 }
 237
 238 #define ll_unmap_underlying_metadata(sb, blocknr) \
 239         unmap_underlying_metadata((sb)->s_bdev, blocknr)
 240
 241 #ifndef EXT3_MB_HINT_GROUP_ALLOC
 242 static unsigned long new_blocks(handle_t *handle, struct ext3_ext_base *base,
 243                                 struct ext3_ext_path *path, unsigned long block,
 244                                 unsigned long *count, int *err)
 245 {
 246         unsigned long pblock, goal;
 247         int aflags = 0;
 248         struct inode *inode = ext3_ext_base2inode(base);
 249
 250         goal = ext3_ext_find_goal(inode, path, block, &aflags);
 251         aflags |= 2; /* block have been already reserved */
 252         pblock = ext3_mb_new_blocks(handle, inode, goal, count, aflags, err);
 253         return pblock;
 254
 255 }
 256 #else
 257 static unsigned long new_blocks(handle_t *handle, struct ext3_ext_base *base,
 258                                 struct ext3_ext_path *path, unsigned long block,
 259                                 unsigned long *count, int *err)
 260 {
 261         struct inode *inode = ext3_ext_base2inode(base);
 262         struct ext3_allocation_request ar;
 263         unsigned long pblock;
 264         int aflags;
 265
 266         /* find neighbour allocated blocks */
 267         ar.lleft = block;
 268         *err = ext3_ext_search_left(base, path, &ar.lleft, &ar.pleft);
 269         if (*err)
 270                 return 0;
 271         ar.lright = block;
 272         *err = ext3_ext_search_right(base, path, &ar.lright, &ar.pright);
 273         if (*err)
 274                 return 0;
 275
 276         /* allocate new block */
 277         ar.goal = ext3_ext_find_goal(inode, path, block, &aflags);
 278         ar.inode = inode;
 279         ar.logical = block;
 280         ar.len = *count;
 281         ar.flags = EXT3_MB_HINT_DATA;
 282         pblock = ext3_mb_new_blocks(handle, &ar, err);
 283         *count = ar.len;
 284         return pblock;
 285 }
 286 #endif
 287
 288 static int ext3_ext_new_extent_cb(struct ext3_ext_base *base,
 289                                   struct ext3_ext_path *path,
 290                                   struct ext3_ext_cache *cex,
 291 #ifdef HAVE_EXT_PREPARE_CB_EXTENT
 292                                    struct ext3_extent *ex,
 293 #endif
 294                                   void *cbdata)
 295 {
 296         struct bpointers *bp = cbdata;
 297         struct inode *inode = ext3_ext_base2inode(base);
 298         struct ext3_extent nex;
 299         unsigned long pblock;
 300         unsigned long tgen;
 301         int err, i;
 302         unsigned long count;
 303         handle_t *handle;
 304
 305 #ifdef EXT3_EXT_CACHE_EXTENT
 306         if (cex->ec_type == EXT3_EXT_CACHE_EXTENT)
 307 #else
 308         if ((cex->ec_len != 0) && (cex->ec_start != 0))
 309 #endif
 310                                                    {
 311                 err = EXT_CONTINUE;
 312                 goto map;
 313         }
 314
 315         if (bp->create == 0) {
 316                 i = 0;
 317                 if (cex->ec_block < bp->start)
 318                         i = bp->start - cex->ec_block;
 319                 if (i >= cex->ec_len)
 320                         CERROR("nothing to do?! i = %d, e_num = %u\n",
 321                                         i, cex->ec_len);
 322                 for (; i < cex->ec_len && bp->num; i++) {
 323                         *(bp->blocks) = 0;
 324                         bp->blocks++;
 325                         bp->num--;
 326                         bp->start++;
 327                 }
 328
 329                 return EXT_CONTINUE;
 330         }
 331
 332         tgen = EXT_GENERATION(base);
 333         count = ext3_ext_calc_credits_for_insert(base, path);
 334
 335         handle = ext3_journal_start(inode, count+EXT3_ALLOC_NEEDED+1);
 336         if (IS_ERR(handle)) {
 337                 return PTR_ERR(handle);
 338         }
 339
 340         if (tgen != EXT_GENERATION(base)) {
 341                 /* the tree has changed. so path can be invalid at moment */
 342                 ext3_journal_stop(handle);
 343                 return EXT_REPEAT;
 344         }
 345
 346         /* In 2.6.32 kernel, ext4_ext_walk_space()'s callback func is not
 347          * protected by i_data_sem as whole. so we patch it to store
 348          * generation to path and now verify the tree hasn't changed */
 349         down_write((&EXT4_I(inode)->i_data_sem));
 350
 351         /* validate extent, make sure the extent tree does not changed */
 352         if (EXT_GENERATION(base) != path[0].p_generation) {
 353                 /* cex is invalid, try again */
 354                 up_write(&EXT4_I(inode)->i_data_sem);
 355                 ext3_journal_stop(handle);
 356                 return EXT_REPEAT;
 357         }
 358
 359         count = cex->ec_len;
 360         pblock = new_blocks(handle, base, path, cex->ec_block, &count, &err);
 361         if (!pblock)
 362                 goto out;
 363         EXT_ASSERT(count <= cex->ec_len);
 364
 365         /* insert new extent */
 366         nex.ee_block = cpu_to_le32(cex->ec_block);
 367         ext3_ext_store_pblock(&nex, pblock);
 368         nex.ee_len = cpu_to_le16(count);
 369         err = fsfilt_ext3_ext_insert_extent(handle, base, path, &nex, 0);
 370         if (err) {
 371                 /* free data blocks we just allocated */
 372                 /* not a good idea to call discard here directly,
 373                  * but otherwise we'd need to call it every free() */
 374 #ifdef EXT3_MB_HINT_GROUP_ALLOC
 375                 ext3_mb_discard_inode_preallocations(inode);
 376 #endif
 377 #ifdef HAVE_EXT_FREE_BLOCK_WITH_BUFFER_HEAD /* Introduced in 2.6.32-rc7 */
 378                 ext3_free_blocks(handle, inode, NULL, ext4_ext_pblock(&nex),
 379                                  cpu_to_le16(nex.ee_len), 0);
 380 #else
 381                 ext3_free_blocks(handle, inode, ext4_ext_pblock(&nex),
 382                                  cpu_to_le16(nex.ee_len), 0);
 383 #endif
 384                 goto out;
 385         }
 386
 387         /*
 388          * Putting len of the actual extent we just inserted,
 389          * we are asking ext3_ext_walk_space() to continue
 390          * scaning after that block
 391          */
 392         cex->ec_len = le16_to_cpu(nex.ee_len);
 393         cex->ec_start = ext4_ext_pblock(&nex);
 394         BUG_ON(le16_to_cpu(nex.ee_len) == 0);
 395         BUG_ON(le32_to_cpu(nex.ee_block) != cex->ec_block);
 396
 397 out:
 398         up_write((&EXT4_I(inode)->i_data_sem));
 399         ext3_journal_stop(handle);
 400 map:
 401         if (err >= 0) {
 402                 /* map blocks */
 403                 if (bp->num == 0) {
 404                         CERROR("hmm. why do we find this extent?\n");
 405                         CERROR("initial space: %lu:%u\n",
 406                                 bp->start, bp->init_num);
 407 #ifdef EXT3_EXT_CACHE_EXTENT
 408                         CERROR("current extent: %u/%u/%llu %d\n",
 409                                 cex->ec_block, cex->ec_len,
 410                                 (unsigned long long)cex->ec_start,
 411                                 cex->ec_type);
 412 #else
 413                         CERROR("current extent: %u/%u/%llu\n",
 414                                 cex->ec_block, cex->ec_len,
 415                                 (unsigned long long)cex->ec_start);
 416 #endif
 417                 }
 418                 i = 0;
 419                 if (cex->ec_block < bp->start)
 420                         i = bp->start - cex->ec_block;
 421                 if (i >= cex->ec_len)
 422                         CERROR("nothing to do?! i = %d, e_num = %u\n",
 423                                         i, cex->ec_len);
 424                 for (; i < cex->ec_len && bp->num; i++) {
 425                         *(bp->blocks) = cex->ec_start + i;
 426 #ifdef EXT3_EXT_CACHE_EXTENT
 427                         if (cex->ec_type != EXT3_EXT_CACHE_EXTENT)
 428 #else
 429                         if ((cex->ec_len == 0) || (cex->ec_start == 0))
 430 #endif
 431                                                                         {
 432                                 /* unmap any possible underlying metadata from
 433                                  * the block device mapping.  bug 6998. */
 434                                 ll_unmap_underlying_metadata(inode->i_sb,
 435                                                              *(bp->blocks));
 436                         }
 437                         bp->blocks++;
 438                         bp->num--;
 439                         bp->start++;
 440                 }
 441         }
 442         return err;
 443 }
 444
 445 int fsfilt_map_nblocks(struct inode *inode, unsigned long block,
 446                        unsigned long num, unsigned long *blocks,
 447                        int create)
 448 {
 449         struct ext3_ext_base *base = inode;
 450         struct bpointers bp;
 451         int err;
 452
 453         CDEBUG(D_OTHER, "blocks %lu-%lu requested for inode %u\n",
 454                block, block + num - 1, (unsigned) inode->i_ino);
 455
 456         bp.blocks = blocks;
 457         bp.start = block;
 458         bp.init_num = bp.num = num;
 459         bp.create = create;
 460
 461         err = fsfilt_ext3_ext_walk_space(base, block, num,
 462                                          ext3_ext_new_extent_cb, &bp);
 463         ext3_ext_invalidate_cache(base);
 464
 465         return err;
 466 }
 467
 468 int fsfilt_ext3_map_ext_inode_pages(struct inode *inode, struct page **page,
 469                                     int pages, unsigned long *blocks,
 470                                     int create)
 471 {
 472         int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits;
 473         int rc = 0, i = 0;
 474         struct page *fp = NULL;
 475         int clen = 0;
 476
 477         CDEBUG(D_OTHER, "inode %lu: map %d pages from %lu\n",
 478                 inode->i_ino, pages, (*page)->index);
 479
 480         /* pages are sorted already. so, we just have to find
 481          * contig. space and process them properly */
 482         while (i < pages) {
 483                 if (fp == NULL) {
 484                         /* start new extent */
 485                         fp = *page++;
 486                         clen = 1;
 487                         i++;
 488                         continue;
 489                 } else if (fp->index + clen == (*page)->index) {
 490                         /* continue the extent */
 491                         page++;
 492                         clen++;
 493                         i++;
 494                         continue;
 495                 }
 496
 497                 /* process found extent */
 498                 rc = fsfilt_map_nblocks(inode, fp->index * blocks_per_page,
 499                                         clen * blocks_per_page, blocks,
 500                                         create);
 501                 if (rc)
 502                         GOTO(cleanup, rc);
 503
 504                 /* look for next extent */
 505                 fp = NULL;
 506                 blocks += 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                                         create);
 513 cleanup:
 514         return rc;
 515 }
 516
 517 int fsfilt_ext3_map_bm_inode_pages(struct inode *inode, struct page **page,
 518                                    int pages, unsigned long *blocks,
 519                                    int create)
 520 {
 521         int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits;
 522         unsigned long *b;
 523         int rc = 0, i;
 524
 525         for (i = 0, b = blocks; i < pages; i++, page++) {
 526                 rc = ext3_map_inode_page(inode, *page, b, create);
 527                 if (rc) {
 528                         CERROR("ino %lu, blk %lu create %d: rc %d\n",
 529                                inode->i_ino, *b, create, rc);
 530                         break;
 531                 }
 532
 533                 b += blocks_per_page;
 534         }
 535         return rc;
 536 }
 537
 538 int fsfilt_ext3_map_inode_pages(struct inode *inode, struct page **page,
 539                                 int pages, unsigned long *blocks,
 540                                 int create, struct mutex *optional_mutex)
 541 {
 542         int rc;
 543
 544         if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL) {
 545                 rc = fsfilt_ext3_map_ext_inode_pages(inode, page, pages,
 546                                                      blocks, create);
 547                 return rc;
 548         }
 549         if (optional_mutex != NULL)
 550                 mutex_lock(optional_mutex);
 551         rc = fsfilt_ext3_map_bm_inode_pages(inode, page, pages, blocks, create);
 552         if (optional_mutex != NULL)
 553                 mutex_unlock(optional_mutex);
 554
 555         return rc;
 556 }
 557
 558 int fsfilt_ext3_read(struct inode *inode, void *buf, int size, loff_t *offs)
 559 {
 560         unsigned long block;
 561         struct buffer_head *bh;
 562         int err, blocksize, csize, boffs, osize = size;
 563
 564         /* prevent reading after eof */
 565         spin_lock(&inode->i_lock);
 566         if (i_size_read(inode) < *offs + size) {
 567                 size = i_size_read(inode) - *offs;
 568                 spin_unlock(&inode->i_lock);
 569                 if (size < 0) {
 570                         CDEBUG(D_EXT2, "size %llu is too short for read @%llu\n",
 571                                i_size_read(inode), *offs);
 572                         return -EBADR;
 573                 } else if (size == 0) {
 574                         return 0;
 575                 }
 576         } else {
 577                 spin_unlock(&inode->i_lock);
 578         }
 579
 580         blocksize = 1 << inode->i_blkbits;
 581
 582         while (size > 0) {
 583                 block = *offs >> inode->i_blkbits;
 584                 boffs = *offs & (blocksize - 1);
 585                 csize = min(blocksize - boffs, size);
 586                 bh = ext3_bread(NULL, inode, block, 0, &err);
 587                 if (!bh) {
 588                         CERROR("can't read block: %d\n", err);
 589                         return err;
 590                 }
 591
 592                 memcpy(buf, bh->b_data + boffs, csize);
 593                 brelse(bh);
 594
 595                 *offs += csize;
 596                 buf += csize;
 597                 size -= csize;
 598         }
 599         return osize;
 600 }
 601 EXPORT_SYMBOL(fsfilt_ext3_read);
 602
 603 static int fsfilt_ext3_read_record(struct file * file, void *buf,
 604                                    int size, loff_t *offs)
 605 {
 606         int rc;
 607         rc = fsfilt_ext3_read(file->f_dentry->d_inode, buf, size, offs);
 608         if (rc > 0)
 609                 rc = 0;
 610         return rc;
 611 }
 612
 613 int fsfilt_ext3_write_handle(struct inode *inode, void *buf, int bufsize,
 614                                 loff_t *offs, handle_t *handle)
 615 {
 616         struct buffer_head *bh = NULL;
 617         loff_t old_size = i_size_read(inode), offset = *offs;
 618         loff_t new_size = i_size_read(inode);
 619         unsigned long block;
 620         int err = 0, blocksize = 1 << inode->i_blkbits, size, boffs;
 621
 622         while (bufsize > 0) {
 623                 if (bh != NULL)
 624                         brelse(bh);
 625
 626                 block = offset >> inode->i_blkbits;
 627                 boffs = offset & (blocksize - 1);
 628                 size = min(blocksize - boffs, bufsize);
 629                 bh = ext3_bread(handle, inode, block, 1, &err);
 630                 if (!bh) {
 631                         CERROR("can't read/create block: %d\n", err);
 632                         break;
 633                 }
 634
 635                 err = ext3_journal_get_write_access(handle, bh);
 636                 if (err) {
 637                         CERROR("journal_get_write_access() returned error %d\n",
 638                                err);
 639                         break;
 640                 }
 641                 LASSERT(bh->b_data + boffs + size <= bh->b_data + bh->b_size);
 642                 memcpy(bh->b_data + boffs, buf, size);
 643                 err = ext3_journal_dirty_metadata(handle, bh);
 644                 if (err) {
 645                         CERROR("journal_dirty_metadata() returned error %d\n",
 646                                err);
 647                         break;
 648                 }
 649                 if (offset + size > new_size)
 650                         new_size = offset + size;
 651                 offset += size;
 652                 bufsize -= size;
 653                 buf += size;
 654         }
 655         if (bh)
 656                 brelse(bh);
 657
 658         /* correct in-core and on-disk sizes */
 659         if (new_size > i_size_read(inode)) {
 660                 spin_lock(&inode->i_lock);
 661                 if (new_size > i_size_read(inode))
 662                         i_size_write(inode, new_size);
 663                 if (i_size_read(inode) > EXT3_I(inode)->i_disksize)
 664                         EXT3_I(inode)->i_disksize = i_size_read(inode);
 665                 if (i_size_read(inode) > old_size) {
 666                         spin_unlock(&inode->i_lock);
 667                         mark_inode_dirty(inode);
 668                 } else {
 669                         spin_unlock(&inode->i_lock);
 670                 }
 671         }
 672
 673         if (err == 0)
 674                 *offs = offset;
 675         return err;
 676 }
 677 EXPORT_SYMBOL(fsfilt_ext3_write_handle);
 678
 679 static int fsfilt_ext3_write_record(struct file *file, void *buf, int bufsize,
 680                                     loff_t *offs, int force_sync)
 681 {
 682         struct inode *inode = file->f_dentry->d_inode;
 683         handle_t *handle;
 684         int err, block_count = 0, blocksize;
 685
 686         /* Determine how many transaction credits are needed */
 687         blocksize = 1 << inode->i_blkbits;
 688         block_count = (*offs & (blocksize - 1)) + bufsize;
 689         block_count = (block_count + blocksize - 1) >> inode->i_blkbits;
 690
 691         handle = ext3_journal_start(inode,
 692                         block_count * EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + 2);
 693         if (IS_ERR(handle)) {
 694                 CERROR("can't start transaction for %d blocks (%d bytes)\n",
 695                        block_count * EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + 2,
 696                        bufsize);
 697                 return PTR_ERR(handle);
 698         }
 699
 700         err = fsfilt_ext3_write_handle(inode, buf, bufsize, offs, handle);
 701
 702         if (!err && force_sync)
 703                 handle->h_sync = 1; /* recovery likes this */
 704
 705         ext3_journal_stop(handle);
 706
 707         return err;
 708 }
 709
 710 static int fsfilt_ext3_setup(struct super_block *sb)
 711 {
 712         if (!EXT3_HAS_COMPAT_FEATURE(sb,
 713                                 EXT3_FEATURE_COMPAT_HAS_JOURNAL)) {
 714                 CERROR("ext3 mounted without journal\n");
 715                 return -EINVAL;
 716         }
 717
 718 #ifdef S_PDIROPS
 719         CWARN("Enabling PDIROPS\n");
 720         set_opt(EXT3_SB(sb)->s_mount_opt, PDIROPS);
 721         sb->s_flags |= S_PDIROPS;
 722 #endif
 723         if (!EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_DIR_INDEX))
 724                 CWARN("filesystem doesn't have dir_index feature enabled\n");
 725         return 0;
 726 }
 727 static struct fsfilt_operations fsfilt_ext3_ops = {
 728         .fs_type                = "ext3",
 729         .fs_owner               = THIS_MODULE,
 730         .fs_getlabel            = fsfilt_ext3_get_label,
 731         .fs_start               = fsfilt_ext3_start,
 732         .fs_commit              = fsfilt_ext3_commit,
 733         .fs_map_inode_pages     = fsfilt_ext3_map_inode_pages,
 734         .fs_write_record        = fsfilt_ext3_write_record,
 735         .fs_read_record         = fsfilt_ext3_read_record,
 736         .fs_setup               = fsfilt_ext3_setup,
 737 };
 738
 739 static int __init fsfilt_ext3_init(void)
 740 {
 741         int rc;
 742
 743         fcb_cache = kmem_cache_create("fsfilt_ext3_fcb",
 744                                       sizeof(struct fsfilt_cb_data),
 745                                       0, 0, NULL);
 746         if (!fcb_cache) {
 747                 CERROR("error allocating fsfilt journal callback cache\n");
 748                 GOTO(out, rc = -ENOMEM);
 749         }
 750
 751         rc = fsfilt_register_ops(&fsfilt_ext3_ops);
 752
 753         if (rc)
 754                 kmem_cache_destroy(fcb_cache);
 755 out:
 756         return rc;
 757 }
 758
 759 static void __exit fsfilt_ext3_exit(void)
 760 {
 761         fsfilt_unregister_ops(&fsfilt_ext3_ops);
 762         kmem_cache_destroy(fcb_cache);
 763 }
 764
 765 module_init(fsfilt_ext3_init);
 766 module_exit(fsfilt_ext3_exit);
 767
 768 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 769 MODULE_DESCRIPTION("Lustre ext3 Filesystem Helper v0.1");
 770 MODULE_LICENSE("GPL");