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_defer.h"
  28 #include "xfs_da_format.h"
  29 #include "xfs_da_btree.h"
  30 #include "xfs_inode.h"
  31 #include "xfs_alloc.h"
  32 #include "xfs_trans.h"
  33 #include "xfs_inode_item.h"
  34 #include "xfs_bmap.h"
  35 #include "xfs_bmap_util.h"
  36 #include "xfs_attr.h"
  37 #include "xfs_attr_leaf.h"
  38 #include "xfs_attr_remote.h"
  39 #include "xfs_trans_space.h"
  40 #include "xfs_trace.h"
  41 #include "xfs_cksum.h"
  42 #include "xfs_buf_item.h"
  43 #include "xfs_error.h"
  44
  45 #define ATTR_RMTVALUE_MAPSIZE   1       /* # of map entries at once */
  46
  47 /*
  48  * Each contiguous block has a header, so it is not just a simple attribute
  49  * length to FSB conversion.
  50  */
  51 int
  52 xfs_attr3_rmt_blocks(
  53         struct xfs_mount *mp,
  54         int             attrlen)
  55 {
  56         if (xfs_sb_version_hascrc(&mp->m_sb)) {
  57                 int buflen = XFS_ATTR3_RMT_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
  58                 return (attrlen + buflen - 1) / buflen;
  59         }
  60         return XFS_B_TO_FSB(mp, attrlen);
  61 }
  62
  63 /*
  64  * Checking of the remote attribute header is split into two parts. The verifier
  65  * does CRC, location and bounds checking, the unpacking function checks the
  66  * attribute parameters and owner.
  67  */
  68 static bool
  69 xfs_attr3_rmt_hdr_ok(
  70         void                    *ptr,
  71         xfs_ino_t               ino,
  72         uint32_t                offset,
  73         uint32_t                size,
  74         xfs_daddr_t             bno)
  75 {
  76         struct xfs_attr3_rmt_hdr *rmt = ptr;
  77
  78         if (bno != be64_to_cpu(rmt->rm_blkno))
  79                 return false;
  80         if (offset != be32_to_cpu(rmt->rm_offset))
  81                 return false;
  82         if (size != be32_to_cpu(rmt->rm_bytes))
  83                 return false;
  84         if (ino != be64_to_cpu(rmt->rm_owner))
  85                 return false;
  86
  87         /* ok */
  88         return true;
  89 }
  90
  91 static bool
  92 xfs_attr3_rmt_verify(
  93         struct xfs_mount        *mp,
  94         void                    *ptr,
  95         int                     fsbsize,
  96         xfs_daddr_t             bno)
  97 {
  98         struct xfs_attr3_rmt_hdr *rmt = ptr;
  99
 100         if (!xfs_sb_version_hascrc(&mp->m_sb))
 101                 return false;
 102         if (rmt->rm_magic != cpu_to_be32(XFS_ATTR3_RMT_MAGIC))
 103                 return false;
 104         if (!uuid_equal(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid))
 105                 return false;
 106         if (be64_to_cpu(rmt->rm_blkno) != bno)
 107                 return false;
 108         if (be32_to_cpu(rmt->rm_bytes) > fsbsize - sizeof(*rmt))
 109                 return false;
 110         if (be32_to_cpu(rmt->rm_offset) +
 111                                 be32_to_cpu(rmt->rm_bytes) > XFS_XATTR_SIZE_MAX)
 112                 return false;
 113         if (rmt->rm_owner == 0)
 114                 return false;
 115
 116         return true;
 117 }
 118
 119 static void
 120 xfs_attr3_rmt_read_verify(
 121         struct xfs_buf  *bp)
 122 {
 123         struct xfs_mount *mp = bp->b_target->bt_mount;
 124         char            *ptr;
 125         int             len;
 126         xfs_daddr_t     bno;
 127         int             blksize = mp->m_attr_geo->blksize;
 128
 129         /* no verification of non-crc buffers */
 130         if (!xfs_sb_version_hascrc(&mp->m_sb))
 131                 return;
 132
 133         ptr = bp->b_addr;
 134         bno = bp->b_bn;
 135         len = BBTOB(bp->b_length);
 136         ASSERT(len >= blksize);
 137
 138         while (len > 0) {
 139                 if (!xfs_verify_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF)) {
 140                         xfs_buf_ioerror(bp, -EFSBADCRC);
 141                         break;
 142                 }
 143                 if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) {
 144                         xfs_buf_ioerror(bp, -EFSCORRUPTED);
 145                         break;
 146                 }
 147                 len -= blksize;
 148                 ptr += blksize;
 149                 bno += BTOBB(blksize);
 150         }
 151
 152         if (bp->b_error)
 153                 xfs_verifier_error(bp);
 154         else
 155                 ASSERT(len == 0);
 156 }
 157
 158 static void
 159 xfs_attr3_rmt_write_verify(
 160         struct xfs_buf  *bp)
 161 {
 162         struct xfs_mount *mp = bp->b_target->bt_mount;
 163         int             blksize = mp->m_attr_geo->blksize;
 164         char            *ptr;
 165         int             len;
 166         xfs_daddr_t     bno;
 167
 168         /* no verification of non-crc buffers */
 169         if (!xfs_sb_version_hascrc(&mp->m_sb))
 170                 return;
 171
 172         ptr = bp->b_addr;
 173         bno = bp->b_bn;
 174         len = BBTOB(bp->b_length);
 175         ASSERT(len >= blksize);
 176
 177         while (len > 0) {
 178                 struct xfs_attr3_rmt_hdr *rmt = (struct xfs_attr3_rmt_hdr *)ptr;
 179
 180                 if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) {
 181                         xfs_buf_ioerror(bp, -EFSCORRUPTED);
 182                         xfs_verifier_error(bp);
 183                         return;
 184                 }
 185
 186                 /*
 187                  * Ensure we aren't writing bogus LSNs to disk. See
 188                  * xfs_attr3_rmt_hdr_set() for the explanation.
 189                  */
 190                 if (rmt->rm_lsn != cpu_to_be64(NULLCOMMITLSN)) {
 191                         xfs_buf_ioerror(bp, -EFSCORRUPTED);
 192                         xfs_verifier_error(bp);
 193                         return;
 194                 }
 195                 xfs_update_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF);
 196
 197                 len -= blksize;
 198                 ptr += blksize;
 199                 bno += BTOBB(blksize);
 200         }
 201         ASSERT(len == 0);
 202 }
 203
 204 const struct xfs_buf_ops xfs_attr3_rmt_buf_ops = {
 205         .name = "xfs_attr3_rmt",
 206         .verify_read = xfs_attr3_rmt_read_verify,
 207         .verify_write = xfs_attr3_rmt_write_verify,
 208 };
 209
 210 STATIC int
 211 xfs_attr3_rmt_hdr_set(
 212         struct xfs_mount        *mp,
 213         void                    *ptr,
 214         xfs_ino_t               ino,
 215         uint32_t                offset,
 216         uint32_t                size,
 217         xfs_daddr_t             bno)
 218 {
 219         struct xfs_attr3_rmt_hdr *rmt = ptr;
 220
 221         if (!xfs_sb_version_hascrc(&mp->m_sb))
 222                 return 0;
 223
 224         rmt->rm_magic = cpu_to_be32(XFS_ATTR3_RMT_MAGIC);
 225         rmt->rm_offset = cpu_to_be32(offset);
 226         rmt->rm_bytes = cpu_to_be32(size);
 227         uuid_copy(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid);
 228         rmt->rm_owner = cpu_to_be64(ino);
 229         rmt->rm_blkno = cpu_to_be64(bno);
 230
 231         /*
 232          * Remote attribute blocks are written synchronously, so we don't
 233          * have an LSN that we can stamp in them that makes any sense to log
 234          * recovery. To ensure that log recovery handles overwrites of these
 235          * blocks sanely (i.e. once they've been freed and reallocated as some
 236          * other type of metadata) we need to ensure that the LSN has a value
 237          * that tells log recovery to ignore the LSN and overwrite the buffer
 238          * with whatever is in it's log. To do this, we use the magic
 239          * NULLCOMMITLSN to indicate that the LSN is invalid.
 240          */
 241         rmt->rm_lsn = cpu_to_be64(NULLCOMMITLSN);
 242
 243         return sizeof(struct xfs_attr3_rmt_hdr);
 244 }
 245
 246 /*
 247  * Helper functions to copy attribute data in and out of the one disk extents
 248  */
 249 STATIC int
 250 xfs_attr_rmtval_copyout(
 251         struct xfs_mount *mp,
 252         struct xfs_buf  *bp,
 253         xfs_ino_t       ino,
 254         int             *offset,
 255         int             *valuelen,
 256         __uint8_t       **dst)
 257 {
 258         char            *src = bp->b_addr;
 259         xfs_daddr_t     bno = bp->b_bn;
 260         int             len = BBTOB(bp->b_length);
 261         int             blksize = mp->m_attr_geo->blksize;
 262
 263         ASSERT(len >= blksize);
 264
 265         while (len > 0 && *valuelen > 0) {
 266                 int hdr_size = 0;
 267                 int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize);
 268
 269                 byte_cnt = min(*valuelen, byte_cnt);
 270
 271                 if (xfs_sb_version_hascrc(&mp->m_sb)) {
 272                         if (!xfs_attr3_rmt_hdr_ok(src, ino, *offset,
 273                                                   byte_cnt, bno)) {
 274                                 xfs_alert(mp,
 275 "remote attribute header mismatch bno/off/len/owner (0x%llx/0x%x/Ox%x/0x%llx)",
 276                                         bno, *offset, byte_cnt, ino);
 277                                 return -EFSCORRUPTED;
 278                         }
 279                         hdr_size = sizeof(struct xfs_attr3_rmt_hdr);
 280                 }
 281
 282                 memcpy(*dst, src + hdr_size, byte_cnt);
 283
 284                 /* roll buffer forwards */
 285                 len -= blksize;
 286                 src += blksize;
 287                 bno += BTOBB(blksize);
 288
 289                 /* roll attribute data forwards */
 290                 *valuelen -= byte_cnt;
 291                 *dst += byte_cnt;
 292                 *offset += byte_cnt;
 293         }
 294         return 0;
 295 }
 296
 297 STATIC void
 298 xfs_attr_rmtval_copyin(
 299         struct xfs_mount *mp,
 300         struct xfs_buf  *bp,
 301         xfs_ino_t       ino,
 302         int             *offset,
 303         int             *valuelen,
 304         __uint8_t       **src)
 305 {
 306         char            *dst = bp->b_addr;
 307         xfs_daddr_t     bno = bp->b_bn;
 308         int             len = BBTOB(bp->b_length);
 309         int             blksize = mp->m_attr_geo->blksize;
 310
 311         ASSERT(len >= blksize);
 312
 313         while (len > 0 && *valuelen > 0) {
 314                 int hdr_size;
 315                 int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize);
 316
 317                 byte_cnt = min(*valuelen, byte_cnt);
 318                 hdr_size = xfs_attr3_rmt_hdr_set(mp, dst, ino, *offset,
 319                                                  byte_cnt, bno);
 320
 321                 memcpy(dst + hdr_size, *src, byte_cnt);
 322
 323                 /*
 324                  * If this is the last block, zero the remainder of it.
 325                  * Check that we are actually the last block, too.
 326                  */
 327                 if (byte_cnt + hdr_size < blksize) {
 328                         ASSERT(*valuelen - byte_cnt == 0);
 329                         ASSERT(len == blksize);
 330                         memset(dst + hdr_size + byte_cnt, 0,
 331                                         blksize - hdr_size - byte_cnt);
 332                 }
 333
 334                 /* roll buffer forwards */
 335                 len -= blksize;
 336                 dst += blksize;
 337                 bno += BTOBB(blksize);
 338
 339                 /* roll attribute data forwards */
 340                 *valuelen -= byte_cnt;
 341                 *src += byte_cnt;
 342                 *offset += byte_cnt;
 343         }
 344 }
 345
 346 /*
 347  * Read the value associated with an attribute from the out-of-line buffer
 348  * that we stored it in.
 349  */
 350 int
 351 xfs_attr_rmtval_get(
 352         struct xfs_da_args      *args)
 353 {
 354         struct xfs_bmbt_irec    map[ATTR_RMTVALUE_MAPSIZE];
 355         struct xfs_mount        *mp = args->dp->i_mount;
 356         struct xfs_buf          *bp;
 357         xfs_dablk_t             lblkno = args->rmtblkno;
 358         __uint8_t               *dst = args->value;
 359         int                     valuelen;
 360         int                     nmap;
 361         int                     error;
 362         int                     blkcnt = args->rmtblkcnt;
 363         int                     i;
 364         int                     offset = 0;
 365
 366         trace_xfs_attr_rmtval_get(args);
 367
 368         ASSERT(!(args->flags & ATTR_KERNOVAL));
 369         ASSERT(args->rmtvaluelen == args->valuelen);
 370
 371         valuelen = args->rmtvaluelen;
 372         while (valuelen > 0) {
 373                 nmap = ATTR_RMTVALUE_MAPSIZE;
 374                 error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
 375                                        blkcnt, map, &nmap,
 376                                        XFS_BMAPI_ATTRFORK);
 377                 if (error)
 378                         return error;
 379                 ASSERT(nmap >= 1);
 380
 381                 for (i = 0; (i < nmap) && (valuelen > 0); i++) {
 382                         xfs_daddr_t     dblkno;
 383                         int             dblkcnt;
 384
 385                         ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) &&
 386                                (map[i].br_startblock != HOLESTARTBLOCK));
 387                         dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
 388                         dblkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
 389                         error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
 390                                                    dblkno, dblkcnt, 0, &bp,
 391                                                    &xfs_attr3_rmt_buf_ops);
 392                         if (error)
 393                                 return error;
 394
 395                         error = xfs_attr_rmtval_copyout(mp, bp, args->dp->i_ino,
 396                                                         &offset, &valuelen,
 397                                                         &dst);
 398                         xfs_buf_relse(bp);
 399                         if (error)
 400                                 return error;
 401
 402                         /* roll attribute extent map forwards */
 403                         lblkno += map[i].br_blockcount;
 404                         blkcnt -= map[i].br_blockcount;
 405                 }
 406         }
 407         ASSERT(valuelen == 0);
 408         return 0;
 409 }
 410
 411 /*
 412  * Write the value associated with an attribute into the out-of-line buffer
 413  * that we have defined for it.
 414  */
 415 int
 416 xfs_attr_rmtval_set(
 417         struct xfs_da_args      *args)
 418 {
 419         struct xfs_inode        *dp = args->dp;
 420         struct xfs_mount        *mp = dp->i_mount;
 421         struct xfs_bmbt_irec    map;
 422         xfs_dablk_t             lblkno;
 423         xfs_fileoff_t           lfileoff = 0;
 424         __uint8_t               *src = args->value;
 425         int                     blkcnt;
 426         int                     valuelen;
 427         int                     nmap;
 428         int                     error;
 429         int                     offset = 0;
 430
 431         trace_xfs_attr_rmtval_set(args);
 432
 433         /*
 434          * Find a "hole" in the attribute address space large enough for
 435          * us to drop the new attribute's value into. Because CRC enable
 436          * attributes have headers, we can't just do a straight byte to FSB
 437          * conversion and have to take the header space into account.
 438          */
 439         blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen);
 440         error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
 441                                                    XFS_ATTR_FORK);
 442         if (error)
 443                 return error;
 444
 445         args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
 446         args->rmtblkcnt = blkcnt;
 447
 448         /*
 449          * Roll through the "value", allocating blocks on disk as required.
 450          */
 451         while (blkcnt > 0) {
 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_defer_init(args->dfops, 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->dfops);
 469                 if (!error)
 470                         error = xfs_defer_finish(&args->trans, args->dfops, dp);
 471                 if (error) {
 472                         args->trans = NULL;
 473                         xfs_defer_cancel(args->dfops);
 474                         return error;
 475                 }
 476
 477                 ASSERT(nmap == 1);
 478                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 479                        (map.br_startblock != HOLESTARTBLOCK));
 480                 lblkno += map.br_blockcount;
 481                 blkcnt -= map.br_blockcount;
 482
 483                 /*
 484                  * Start the next trans in the chain.
 485                  */
 486                 error = xfs_trans_roll(&args->trans, dp);
 487                 if (error)
 488                         return error;
 489         }
 490
 491         /*
 492          * Roll through the "value", copying the attribute value to the
 493          * already-allocated blocks.  Blocks are written synchronously
 494          * so that we can know they are all on disk before we turn off
 495          * the INCOMPLETE flag.
 496          */
 497         lblkno = args->rmtblkno;
 498         blkcnt = args->rmtblkcnt;
 499         valuelen = args->rmtvaluelen;
 500         while (valuelen > 0) {
 501                 struct xfs_buf  *bp;
 502                 xfs_daddr_t     dblkno;
 503                 int             dblkcnt;
 504
 505                 ASSERT(blkcnt > 0);
 506
 507                 xfs_defer_init(args->dfops, args->firstblock);
 508                 nmap = 1;
 509                 error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
 510                                        blkcnt, &map, &nmap,
 511                                        XFS_BMAPI_ATTRFORK);
 512                 if (error)
 513                         return error;
 514                 ASSERT(nmap == 1);
 515                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 516                        (map.br_startblock != HOLESTARTBLOCK));
 517
 518                 dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
 519                 dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
 520
 521                 bp = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, 0);
 522                 if (!bp)
 523                         return -ENOMEM;
 524                 bp->b_ops = &xfs_attr3_rmt_buf_ops;
 525
 526                 xfs_attr_rmtval_copyin(mp, bp, args->dp->i_ino, &offset,
 527                                        &valuelen, &src);
 528
 529                 error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */
 530                 xfs_buf_relse(bp);
 531                 if (error)
 532                         return error;
 533
 534
 535                 /* roll attribute extent map forwards */
 536                 lblkno += map.br_blockcount;
 537                 blkcnt -= map.br_blockcount;
 538         }
 539         ASSERT(valuelen == 0);
 540         return 0;
 541 }
 542
 543 /*
 544  * Remove the value associated with an attribute by deleting the
 545  * out-of-line buffer that it is stored on.
 546  */
 547 int
 548 xfs_attr_rmtval_remove(
 549         struct xfs_da_args      *args)
 550 {
 551         struct xfs_mount        *mp = args->dp->i_mount;
 552         xfs_dablk_t             lblkno;
 553         int                     blkcnt;
 554         int                     error;
 555         int                     done;
 556
 557         trace_xfs_attr_rmtval_remove(args);
 558
 559         /*
 560          * Roll through the "value", invalidating the attribute value's blocks.
 561          */
 562         lblkno = args->rmtblkno;
 563         blkcnt = args->rmtblkcnt;
 564         while (blkcnt > 0) {
 565                 struct xfs_bmbt_irec    map;
 566                 struct xfs_buf          *bp;
 567                 xfs_daddr_t             dblkno;
 568                 int                     dblkcnt;
 569                 int                     nmap;
 570
 571                 /*
 572                  * Try to remember where we decided to put the value.
 573                  */
 574                 nmap = 1;
 575                 error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
 576                                        blkcnt, &map, &nmap, XFS_BMAPI_ATTRFORK);
 577                 if (error)
 578                         return error;
 579                 ASSERT(nmap == 1);
 580                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 581                        (map.br_startblock != HOLESTARTBLOCK));
 582
 583                 dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
 584                 dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
 585
 586                 /*
 587                  * If the "remote" value is in the cache, remove it.
 588                  */
 589                 bp = xfs_incore(mp->m_ddev_targp, dblkno, dblkcnt, XBF_TRYLOCK);
 590                 if (bp) {
 591                         xfs_buf_stale(bp);
 592                         xfs_buf_relse(bp);
 593                         bp = NULL;
 594                 }
 595
 596                 lblkno += map.br_blockcount;
 597                 blkcnt -= map.br_blockcount;
 598         }
 599
 600         /*
 601          * Keep de-allocating extents until the remote-value region is gone.
 602          */
 603         lblkno = args->rmtblkno;
 604         blkcnt = args->rmtblkcnt;
 605         done = 0;
 606         while (!done) {
 607                 xfs_defer_init(args->dfops, args->firstblock);
 608                 error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt,
 609                                     XFS_BMAPI_ATTRFORK, 1, args->firstblock,
 610                                     args->dfops, &done);
 611                 if (!error)
 612                         error = xfs_defer_finish(&args->trans, args->dfops,
 613                                                 args->dp);
 614                 if (error) {
 615                         args->trans = NULL;
 616                         xfs_defer_cancel(args->dfops);
 617                         return error;
 618                 }
 619
 620                 /*
 621                  * Close out trans and start the next one in the chain.
 622                  */
 623                 error = xfs_trans_roll(&args->trans, args->dp);
 624                 if (error)
 625                         return error;
 626         }
 627         return 0;
 628 }