fs/xfs/libxfs/xfs_attr_remote.c

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * Copyright (c) 2013 Red Hat, Inc.
   4  * All Rights Reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it would be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write the Free Software Foundation,
  17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19 #include "xfs.h"
  20 #include "xfs_fs.h"
  21 #include "xfs_shared.h"
  22 #include "xfs_format.h"
  23 #include "xfs_log_format.h"
  24 #include "xfs_trans_resv.h"
  25 #include "xfs_bit.h"
  26 #include "xfs_mount.h"
  27 #include "xfs_da_format.h"
  28 #include "xfs_da_btree.h"
  29 #include "xfs_inode.h"
  30 #include "xfs_alloc.h"
  31 #include "xfs_trans.h"
  32 #include "xfs_inode_item.h"
  33 #include "xfs_bmap.h"
  34 #include "xfs_bmap_util.h"
  35 #include "xfs_attr.h"
  36 #include "xfs_attr_leaf.h"
  37 #include "xfs_attr_remote.h"
  38 #include "xfs_trans_space.h"
  39 #include "xfs_trace.h"
  40 #include "xfs_cksum.h"
  41 #include "xfs_buf_item.h"
  42 #include "xfs_error.h"
  43
  44 #define ATTR_RMTVALUE_MAPSIZE   1       /* # of map entries at once */
  45
  46 /*
  47  * Each contiguous block has a header, so it is not just a simple attribute
  48  * length to FSB conversion.
  49  */
  50 int
  51 xfs_attr3_rmt_blocks(
  52         struct xfs_mount *mp,
  53         int             attrlen)
  54 {
  55         if (xfs_sb_version_hascrc(&mp->m_sb)) {
  56                 int buflen = XFS_ATTR3_RMT_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
  57                 return (attrlen + buflen - 1) / buflen;
  58         }
  59         return XFS_B_TO_FSB(mp, attrlen);
  60 }
  61
  62 /*
  63  * Checking of the remote attribute header is split into two parts. The verifier
  64  * does CRC, location and bounds checking, the unpacking function checks the
  65  * attribute parameters and owner.
  66  */
  67 static bool
  68 xfs_attr3_rmt_hdr_ok(
  69         void                    *ptr,
  70         xfs_ino_t               ino,
  71         uint32_t                offset,
  72         uint32_t                size,
  73         xfs_daddr_t             bno)
  74 {
  75         struct xfs_attr3_rmt_hdr *rmt = ptr;
  76
  77         if (bno != be64_to_cpu(rmt->rm_blkno))
  78                 return false;
  79         if (offset != be32_to_cpu(rmt->rm_offset))
  80                 return false;
  81         if (size != be32_to_cpu(rmt->rm_bytes))
  82                 return false;
  83         if (ino != be64_to_cpu(rmt->rm_owner))
  84                 return false;
  85
  86         /* ok */
  87         return true;
  88 }
  89
  90 static bool
  91 xfs_attr3_rmt_verify(
  92         struct xfs_mount        *mp,
  93         void                    *ptr,
  94         int                     fsbsize,
  95         xfs_daddr_t             bno)
  96 {
  97         struct xfs_attr3_rmt_hdr *rmt = ptr;
  98
  99         if (!xfs_sb_version_hascrc(&mp->m_sb))
 100                 return false;
 101         if (rmt->rm_magic != cpu_to_be32(XFS_ATTR3_RMT_MAGIC))
 102                 return false;
 103         if (!uuid_equal(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid))
 104                 return false;
 105         if (be64_to_cpu(rmt->rm_blkno) != bno)
 106                 return false;
 107         if (be32_to_cpu(rmt->rm_bytes) > fsbsize - sizeof(*rmt))
 108                 return false;
 109         if (be32_to_cpu(rmt->rm_offset) +
 110                                 be32_to_cpu(rmt->rm_bytes) > XFS_XATTR_SIZE_MAX)
 111                 return false;
 112         if (rmt->rm_owner == 0)
 113                 return false;
 114
 115         return true;
 116 }
 117
 118 static void
 119 xfs_attr3_rmt_read_verify(
 120         struct xfs_buf  *bp)
 121 {
 122         struct xfs_mount *mp = bp->b_target->bt_mount;
 123         char            *ptr;
 124         int             len;
 125         xfs_daddr_t     bno;
 126         int             blksize = mp->m_attr_geo->blksize;
 127
 128         /* no verification of non-crc buffers */
 129         if (!xfs_sb_version_hascrc(&mp->m_sb))
 130                 return;
 131
 132         ptr = bp->b_addr;
 133         bno = bp->b_bn;
 134         len = BBTOB(bp->b_length);
 135         ASSERT(len >= blksize);
 136
 137         while (len > 0) {
 138                 if (!xfs_verify_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF)) {
 139                         xfs_buf_ioerror(bp, -EFSBADCRC);
 140                         break;
 141                 }
 142                 if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) {
 143                         xfs_buf_ioerror(bp, -EFSCORRUPTED);
 144                         break;
 145                 }
 146                 len -= blksize;
 147                 ptr += blksize;
 148                 bno += BTOBB(blksize);
 149         }
 150
 151         if (bp->b_error)
 152                 xfs_verifier_error(bp);
 153         else
 154                 ASSERT(len == 0);
 155 }
 156
 157 static void
 158 xfs_attr3_rmt_write_verify(
 159         struct xfs_buf  *bp)
 160 {
 161         struct xfs_mount *mp = bp->b_target->bt_mount;
 162         int             blksize = mp->m_attr_geo->blksize;
 163         char            *ptr;
 164         int             len;
 165         xfs_daddr_t     bno;
 166
 167         /* no verification of non-crc buffers */
 168         if (!xfs_sb_version_hascrc(&mp->m_sb))
 169                 return;
 170
 171         ptr = bp->b_addr;
 172         bno = bp->b_bn;
 173         len = BBTOB(bp->b_length);
 174         ASSERT(len >= blksize);
 175
 176         while (len > 0) {
 177                 struct xfs_attr3_rmt_hdr *rmt = (struct xfs_attr3_rmt_hdr *)ptr;
 178
 179                 if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) {
 180                         xfs_buf_ioerror(bp, -EFSCORRUPTED);
 181                         xfs_verifier_error(bp);
 182                         return;
 183                 }
 184
 185                 /*
 186                  * Ensure we aren't writing bogus LSNs to disk. See
 187                  * xfs_attr3_rmt_hdr_set() for the explanation.
 188                  */
 189                 if (rmt->rm_lsn != cpu_to_be64(NULLCOMMITLSN)) {
 190                         xfs_buf_ioerror(bp, -EFSCORRUPTED);
 191                         xfs_verifier_error(bp);
 192                         return;
 193                 }
 194                 xfs_update_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF);
 195
 196                 len -= blksize;
 197                 ptr += blksize;
 198                 bno += BTOBB(blksize);
 199         }
 200         ASSERT(len == 0);
 201 }
 202
 203 const struct xfs_buf_ops xfs_attr3_rmt_buf_ops = {
 204         .verify_read = xfs_attr3_rmt_read_verify,
 205         .verify_write = xfs_attr3_rmt_write_verify,
 206 };
 207
 208 STATIC int
 209 xfs_attr3_rmt_hdr_set(
 210         struct xfs_mount        *mp,
 211         void                    *ptr,
 212         xfs_ino_t               ino,
 213         uint32_t                offset,
 214         uint32_t                size,
 215         xfs_daddr_t             bno)
 216 {
 217         struct xfs_attr3_rmt_hdr *rmt = ptr;
 218
 219         if (!xfs_sb_version_hascrc(&mp->m_sb))
 220                 return 0;
 221
 222         rmt->rm_magic = cpu_to_be32(XFS_ATTR3_RMT_MAGIC);
 223         rmt->rm_offset = cpu_to_be32(offset);
 224         rmt->rm_bytes = cpu_to_be32(size);
 225         uuid_copy(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid);
 226         rmt->rm_owner = cpu_to_be64(ino);
 227         rmt->rm_blkno = cpu_to_be64(bno);
 228
 229         /*
 230          * Remote attribute blocks are written synchronously, so we don't
 231          * have an LSN that we can stamp in them that makes any sense to log
 232          * recovery. To ensure that log recovery handles overwrites of these
 233          * blocks sanely (i.e. once they've been freed and reallocated as some
 234          * other type of metadata) we need to ensure that the LSN has a value
 235          * that tells log recovery to ignore the LSN and overwrite the buffer
 236          * with whatever is in it's log. To do this, we use the magic
 237          * NULLCOMMITLSN to indicate that the LSN is invalid.
 238          */
 239         rmt->rm_lsn = cpu_to_be64(NULLCOMMITLSN);
 240
 241         return sizeof(struct xfs_attr3_rmt_hdr);
 242 }
 243
 244 /*
 245  * Helper functions to copy attribute data in and out of the one disk extents
 246  */
 247 STATIC int
 248 xfs_attr_rmtval_copyout(
 249         struct xfs_mount *mp,
 250         struct xfs_buf  *bp,
 251         xfs_ino_t       ino,
 252         int             *offset,
 253         int             *valuelen,
 254         __uint8_t       **dst)
 255 {
 256         char            *src = bp->b_addr;
 257         xfs_daddr_t     bno = bp->b_bn;
 258         int             len = BBTOB(bp->b_length);
 259         int             blksize = mp->m_attr_geo->blksize;
 260
 261         ASSERT(len >= blksize);
 262
 263         while (len > 0 && *valuelen > 0) {
 264                 int hdr_size = 0;
 265                 int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize);
 266
 267                 byte_cnt = min(*valuelen, byte_cnt);
 268
 269                 if (xfs_sb_version_hascrc(&mp->m_sb)) {
 270                         if (!xfs_attr3_rmt_hdr_ok(src, ino, *offset,
 271                                                   byte_cnt, bno)) {
 272                                 xfs_alert(mp,
 273 "remote attribute header mismatch bno/off/len/owner (0x%llx/0x%x/Ox%x/0x%llx)",
 274                                         bno, *offset, byte_cnt, ino);
 275                                 return -EFSCORRUPTED;
 276                         }
 277                         hdr_size = sizeof(struct xfs_attr3_rmt_hdr);
 278                 }
 279
 280                 memcpy(*dst, src + hdr_size, byte_cnt);
 281
 282                 /* roll buffer forwards */
 283                 len -= blksize;
 284                 src += blksize;
 285                 bno += BTOBB(blksize);
 286
 287                 /* roll attribute data forwards */
 288                 *valuelen -= byte_cnt;
 289                 *dst += byte_cnt;
 290                 *offset += byte_cnt;
 291         }
 292         return 0;
 293 }
 294
 295 STATIC void
 296 xfs_attr_rmtval_copyin(
 297         struct xfs_mount *mp,
 298         struct xfs_buf  *bp,
 299         xfs_ino_t       ino,
 300         int             *offset,
 301         int             *valuelen,
 302         __uint8_t       **src)
 303 {
 304         char            *dst = bp->b_addr;
 305         xfs_daddr_t     bno = bp->b_bn;
 306         int             len = BBTOB(bp->b_length);
 307         int             blksize = mp->m_attr_geo->blksize;
 308
 309         ASSERT(len >= blksize);
 310
 311         while (len > 0 && *valuelen > 0) {
 312                 int hdr_size;
 313                 int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize);
 314
 315                 byte_cnt = min(*valuelen, byte_cnt);
 316                 hdr_size = xfs_attr3_rmt_hdr_set(mp, dst, ino, *offset,
 317                                                  byte_cnt, bno);
 318
 319                 memcpy(dst + hdr_size, *src, byte_cnt);
 320
 321                 /*
 322                  * If this is the last block, zero the remainder of it.
 323                  * Check that we are actually the last block, too.
 324                  */
 325                 if (byte_cnt + hdr_size < blksize) {
 326                         ASSERT(*valuelen - byte_cnt == 0);
 327                         ASSERT(len == blksize);
 328                         memset(dst + hdr_size + byte_cnt, 0,
 329                                         blksize - hdr_size - byte_cnt);
 330                 }
 331
 332                 /* roll buffer forwards */
 333                 len -= blksize;
 334                 dst += blksize;
 335                 bno += BTOBB(blksize);
 336
 337                 /* roll attribute data forwards */
 338                 *valuelen -= byte_cnt;
 339                 *src += byte_cnt;
 340                 *offset += byte_cnt;
 341         }
 342 }
 343
 344 /*
 345  * Read the value associated with an attribute from the out-of-line buffer
 346  * that we stored it in.
 347  */
 348 int
 349 xfs_attr_rmtval_get(
 350         struct xfs_da_args      *args)
 351 {
 352         struct xfs_bmbt_irec    map[ATTR_RMTVALUE_MAPSIZE];
 353         struct xfs_mount        *mp = args->dp->i_mount;
 354         struct xfs_buf          *bp;
 355         xfs_dablk_t             lblkno = args->rmtblkno;
 356         __uint8_t               *dst = args->value;
 357         int                     valuelen;
 358         int                     nmap;
 359         int                     error;
 360         int                     blkcnt = args->rmtblkcnt;
 361         int                     i;
 362         int                     offset = 0;
 363
 364         trace_xfs_attr_rmtval_get(args);
 365
 366         ASSERT(!(args->flags & ATTR_KERNOVAL));
 367         ASSERT(args->rmtvaluelen == args->valuelen);
 368
 369         valuelen = args->rmtvaluelen;
 370         while (valuelen > 0) {
 371                 nmap = ATTR_RMTVALUE_MAPSIZE;
 372                 error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
 373                                        blkcnt, map, &nmap,
 374                                        XFS_BMAPI_ATTRFORK);
 375                 if (error)
 376                         return error;
 377                 ASSERT(nmap >= 1);
 378
 379                 for (i = 0; (i < nmap) && (valuelen > 0); i++) {
 380                         xfs_daddr_t     dblkno;
 381                         int             dblkcnt;
 382
 383                         ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) &&
 384                                (map[i].br_startblock != HOLESTARTBLOCK));
 385                         dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
 386                         dblkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
 387                         error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
 388                                                    dblkno, dblkcnt, 0, &bp,
 389                                                    &xfs_attr3_rmt_buf_ops);
 390                         if (error)
 391                                 return error;
 392
 393                         error = xfs_attr_rmtval_copyout(mp, bp, args->dp->i_ino,
 394                                                         &offset, &valuelen,
 395                                                         &dst);
 396                         xfs_buf_relse(bp);
 397                         if (error)
 398                                 return error;
 399
 400                         /* roll attribute extent map forwards */
 401                         lblkno += map[i].br_blockcount;
 402                         blkcnt -= map[i].br_blockcount;
 403                 }
 404         }
 405         ASSERT(valuelen == 0);
 406         return 0;
 407 }
 408
 409 /*
 410  * Write the value associated with an attribute into the out-of-line buffer
 411  * that we have defined for it.
 412  */
 413 int
 414 xfs_attr_rmtval_set(
 415         struct xfs_da_args      *args)
 416 {
 417         struct xfs_inode        *dp = args->dp;
 418         struct xfs_mount        *mp = dp->i_mount;
 419         struct xfs_bmbt_irec    map;
 420         xfs_dablk_t             lblkno;
 421         xfs_fileoff_t           lfileoff = 0;
 422         __uint8_t               *src = args->value;
 423         int                     blkcnt;
 424         int                     valuelen;
 425         int                     nmap;
 426         int                     error;
 427         int                     offset = 0;
 428
 429         trace_xfs_attr_rmtval_set(args);
 430
 431         /*
 432          * Find a "hole" in the attribute address space large enough for
 433          * us to drop the new attribute's value into. Because CRC enable
 434          * attributes have headers, we can't just do a straight byte to FSB
 435          * conversion and have to take the header space into account.
 436          */
 437         blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen);
 438         error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
 439                                                    XFS_ATTR_FORK);
 440         if (error)
 441                 return error;
 442
 443         args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
 444         args->rmtblkcnt = blkcnt;
 445
 446         /*
 447          * Roll through the "value", allocating blocks on disk as required.
 448          */
 449         while (blkcnt > 0) {
 450                 int     committed;
 451
 452                 /*
 453                  * Allocate a single extent, up to the size of the value.
 454                  *
 455                  * Note that we have to consider this a data allocation as we
 456                  * write the remote attribute without logging the contents.
 457                  * Hence we must ensure that we aren't using blocks that are on
 458                  * the busy list so that we don't overwrite blocks which have
 459                  * recently been freed but their transactions are not yet
 460                  * committed to disk. If we overwrite the contents of a busy
 461                  * extent and then crash then the block may not contain the
 462                  * correct metadata after log recovery occurs.
 463                  */
 464                 xfs_bmap_init(args->flist, args->firstblock);
 465                 nmap = 1;
 466                 error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
 467                                   blkcnt, XFS_BMAPI_ATTRFORK, args->firstblock,
 468                                   args->total, &map, &nmap, args->flist);
 469                 if (!error) {
 470                         error = xfs_bmap_finish(&args->trans, args->flist,
 471                                                 &committed);
 472                 }
 473                 if (error) {
 474                         ASSERT(committed);
 475                         args->trans = NULL;
 476                         xfs_bmap_cancel(args->flist);
 477                         return error;
 478                 }
 479
 480                 /*
 481                  * bmap_finish() may have committed the last trans and started
 482                  * a new one.  We need the inode to be in all transactions.
 483                  */
 484                 if (committed)
 485                         xfs_trans_ijoin(args->trans, dp, 0);
 486
 487                 ASSERT(nmap == 1);
 488                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 489                        (map.br_startblock != HOLESTARTBLOCK));
 490                 lblkno += map.br_blockcount;
 491                 blkcnt -= map.br_blockcount;
 492
 493                 /*
 494                  * Start the next trans in the chain.
 495                  */
 496                 error = xfs_trans_roll(&args->trans, dp);
 497                 if (error)
 498                         return error;
 499         }
 500
 501         /*
 502          * Roll through the "value", copying the attribute value to the
 503          * already-allocated blocks.  Blocks are written synchronously
 504          * so that we can know they are all on disk before we turn off
 505          * the INCOMPLETE flag.
 506          */
 507         lblkno = args->rmtblkno;
 508         blkcnt = args->rmtblkcnt;
 509         valuelen = args->rmtvaluelen;
 510         while (valuelen > 0) {
 511                 struct xfs_buf  *bp;
 512                 xfs_daddr_t     dblkno;
 513                 int             dblkcnt;
 514
 515                 ASSERT(blkcnt > 0);
 516
 517                 xfs_bmap_init(args->flist, args->firstblock);
 518                 nmap = 1;
 519                 error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
 520                                        blkcnt, &map, &nmap,
 521                                        XFS_BMAPI_ATTRFORK);
 522                 if (error)
 523                         return error;
 524                 ASSERT(nmap == 1);
 525                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 526                        (map.br_startblock != HOLESTARTBLOCK));
 527
 528                 dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
 529                 dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
 530
 531                 bp = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, 0);
 532                 if (!bp)
 533                         return -ENOMEM;
 534                 bp->b_ops = &xfs_attr3_rmt_buf_ops;
 535
 536                 xfs_attr_rmtval_copyin(mp, bp, args->dp->i_ino, &offset,
 537                                        &valuelen, &src);
 538
 539                 error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */
 540                 xfs_buf_relse(bp);
 541                 if (error)
 542                         return error;
 543
 544
 545                 /* roll attribute extent map forwards */
 546                 lblkno += map.br_blockcount;
 547                 blkcnt -= map.br_blockcount;
 548         }
 549         ASSERT(valuelen == 0);
 550         return 0;
 551 }
 552
 553 /*
 554  * Remove the value associated with an attribute by deleting the
 555  * out-of-line buffer that it is stored on.
 556  */
 557 int
 558 xfs_attr_rmtval_remove(
 559         struct xfs_da_args      *args)
 560 {
 561         struct xfs_mount        *mp = args->dp->i_mount;
 562         xfs_dablk_t             lblkno;
 563         int                     blkcnt;
 564         int                     error;
 565         int                     done;
 566
 567         trace_xfs_attr_rmtval_remove(args);
 568
 569         /*
 570          * Roll through the "value", invalidating the attribute value's blocks.
 571          */
 572         lblkno = args->rmtblkno;
 573         blkcnt = args->rmtblkcnt;
 574         while (blkcnt > 0) {
 575                 struct xfs_bmbt_irec    map;
 576                 struct xfs_buf          *bp;
 577                 xfs_daddr_t             dblkno;
 578                 int                     dblkcnt;
 579                 int                     nmap;
 580
 581                 /*
 582                  * Try to remember where we decided to put the value.
 583                  */
 584                 nmap = 1;
 585                 error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
 586                                        blkcnt, &map, &nmap, XFS_BMAPI_ATTRFORK);
 587                 if (error)
 588                         return error;
 589                 ASSERT(nmap == 1);
 590                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 591                        (map.br_startblock != HOLESTARTBLOCK));
 592
 593                 dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
 594                 dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
 595
 596                 /*
 597                  * If the "remote" value is in the cache, remove it.
 598                  */
 599                 bp = xfs_incore(mp->m_ddev_targp, dblkno, dblkcnt, XBF_TRYLOCK);
 600                 if (bp) {
 601                         xfs_buf_stale(bp);
 602                         xfs_buf_relse(bp);
 603                         bp = NULL;
 604                 }
 605
 606                 lblkno += map.br_blockcount;
 607                 blkcnt -= map.br_blockcount;
 608         }
 609
 610         /*
 611          * Keep de-allocating extents until the remote-value region is gone.
 612          */
 613         lblkno = args->rmtblkno;
 614         blkcnt = args->rmtblkcnt;
 615         done = 0;
 616         while (!done) {
 617                 int committed;
 618
 619                 xfs_bmap_init(args->flist, args->firstblock);
 620                 error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt,
 621                                     XFS_BMAPI_ATTRFORK, 1, args->firstblock,
 622                                     args->flist, &done);
 623                 if (!error) {
 624                         error = xfs_bmap_finish(&args->trans, args->flist,
 625                                                 &committed);
 626                 }
 627                 if (error) {
 628                         ASSERT(committed);
 629                         args->trans = NULL;
 630                         xfs_bmap_cancel(args->flist);
 631                         return error;
 632                 }
 633
 634                 /*
 635                  * bmap_finish() may have committed the last trans and started
 636                  * a new one.  We need the inode to be in all transactions.
 637                  */
 638                 if (committed)
 639                         xfs_trans_ijoin(args->trans, args->dp, 0);
 640
 641                 /*
 642                  * Close out trans and start the next one in the chain.
 643                  */
 644                 error = xfs_trans_roll(&args->trans, args->dp);
 645                 if (error)
 646                         return error;
 647         }
 648         return 0;
 649 }