fs/xfs/xfs_attr_list.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_format.h"
  22 #include "xfs_log_format.h"
  23 #include "xfs_trans_resv.h"
  24 #include "xfs_bit.h"
  25 #include "xfs_sb.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_trans.h"
  31 #include "xfs_inode_item.h"
  32 #include "xfs_bmap.h"
  33 #include "xfs_attr.h"
  34 #include "xfs_attr_sf.h"
  35 #include "xfs_attr_remote.h"
  36 #include "xfs_attr_leaf.h"
  37 #include "xfs_error.h"
  38 #include "xfs_trace.h"
  39 #include "xfs_buf_item.h"
  40 #include "xfs_cksum.h"
  41 #include "xfs_dir2.h"
  42
  43 STATIC int
  44 xfs_attr_shortform_compare(const void *a, const void *b)
  45 {
  46         xfs_attr_sf_sort_t *sa, *sb;
  47
  48         sa = (xfs_attr_sf_sort_t *)a;
  49         sb = (xfs_attr_sf_sort_t *)b;
  50         if (sa->hash < sb->hash) {
  51                 return -1;
  52         } else if (sa->hash > sb->hash) {
  53                 return 1;
  54         } else {
  55                 return sa->entno - sb->entno;
  56         }
  57 }
  58
  59 #define XFS_ISRESET_CURSOR(cursor) \
  60         (!((cursor)->initted) && !((cursor)->hashval) && \
  61          !((cursor)->blkno) && !((cursor)->offset))
  62 /*
  63  * Copy out entries of shortform attribute lists for attr_list().
  64  * Shortform attribute lists are not stored in hashval sorted order.
  65  * If the output buffer is not large enough to hold them all, then we
  66  * we have to calculate each entries' hashvalue and sort them before
  67  * we can begin returning them to the user.
  68  */
  69 int
  70 xfs_attr_shortform_list(xfs_attr_list_context_t *context)
  71 {
  72         attrlist_cursor_kern_t *cursor;
  73         xfs_attr_sf_sort_t *sbuf, *sbp;
  74         xfs_attr_shortform_t *sf;
  75         xfs_attr_sf_entry_t *sfe;
  76         xfs_inode_t *dp;
  77         int sbsize, nsbuf, count, i;
  78         int error;
  79
  80         ASSERT(context != NULL);
  81         dp = context->dp;
  82         ASSERT(dp != NULL);
  83         ASSERT(dp->i_afp != NULL);
  84         sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
  85         ASSERT(sf != NULL);
  86         if (!sf->hdr.count)
  87                 return 0;
  88         cursor = context->cursor;
  89         ASSERT(cursor != NULL);
  90
  91         trace_xfs_attr_list_sf(context);
  92
  93         /*
  94          * If the buffer is large enough and the cursor is at the start,
  95          * do not bother with sorting since we will return everything in
  96          * one buffer and another call using the cursor won't need to be
  97          * made.
  98          * Note the generous fudge factor of 16 overhead bytes per entry.
  99          * If bufsize is zero then put_listent must be a search function
 100          * and can just scan through what we have.
 101          */
 102         if (context->bufsize == 0 ||
 103             (XFS_ISRESET_CURSOR(cursor) &&
 104              (dp->i_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
 105                 for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
 106                         error = context->put_listent(context,
 107                                            sfe->flags,
 108                                            sfe->nameval,
 109                                            (int)sfe->namelen,
 110                                            (int)sfe->valuelen,
 111                                            &sfe->nameval[sfe->namelen]);
 112
 113                         /*
 114                          * Either search callback finished early or
 115                          * didn't fit it all in the buffer after all.
 116                          */
 117                         if (context->seen_enough)
 118                                 break;
 119
 120                         if (error)
 121                                 return error;
 122                         sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
 123                 }
 124                 trace_xfs_attr_list_sf_all(context);
 125                 return 0;
 126         }
 127
 128         /* do no more for a search callback */
 129         if (context->bufsize == 0)
 130                 return 0;
 131
 132         /*
 133          * It didn't all fit, so we have to sort everything on hashval.
 134          */
 135         sbsize = sf->hdr.count * sizeof(*sbuf);
 136         sbp = sbuf = kmem_alloc(sbsize, KM_SLEEP | KM_NOFS);
 137
 138         /*
 139          * Scan the attribute list for the rest of the entries, storing
 140          * the relevant info from only those that match into a buffer.
 141          */
 142         nsbuf = 0;
 143         for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
 144                 if (unlikely(
 145                     ((char *)sfe < (char *)sf) ||
 146                     ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
 147                         XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
 148                                              XFS_ERRLEVEL_LOW,
 149                                              context->dp->i_mount, sfe);
 150                         kmem_free(sbuf);
 151                         return -EFSCORRUPTED;
 152                 }
 153
 154                 sbp->entno = i;
 155                 sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
 156                 sbp->name = sfe->nameval;
 157                 sbp->namelen = sfe->namelen;
 158                 /* These are bytes, and both on-disk, don't endian-flip */
 159                 sbp->valuelen = sfe->valuelen;
 160                 sbp->flags = sfe->flags;
 161                 sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
 162                 sbp++;
 163                 nsbuf++;
 164         }
 165
 166         /*
 167          * Sort the entries on hash then entno.
 168          */
 169         xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
 170
 171         /*
 172          * Re-find our place IN THE SORTED LIST.
 173          */
 174         count = 0;
 175         cursor->initted = 1;
 176         cursor->blkno = 0;
 177         for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
 178                 if (sbp->hash == cursor->hashval) {
 179                         if (cursor->offset == count) {
 180                                 break;
 181                         }
 182                         count++;
 183                 } else if (sbp->hash > cursor->hashval) {
 184                         break;
 185                 }
 186         }
 187         if (i == nsbuf) {
 188                 kmem_free(sbuf);
 189                 return 0;
 190         }
 191
 192         /*
 193          * Loop putting entries into the user buffer.
 194          */
 195         for ( ; i < nsbuf; i++, sbp++) {
 196                 if (cursor->hashval != sbp->hash) {
 197                         cursor->hashval = sbp->hash;
 198                         cursor->offset = 0;
 199                 }
 200                 error = context->put_listent(context,
 201                                         sbp->flags,
 202                                         sbp->name,
 203                                         sbp->namelen,
 204                                         sbp->valuelen,
 205                                         &sbp->name[sbp->namelen]);
 206                 if (error)
 207                         return error;
 208                 if (context->seen_enough)
 209                         break;
 210                 cursor->offset++;
 211         }
 212
 213         kmem_free(sbuf);
 214         return 0;
 215 }
 216
 217 STATIC int
 218 xfs_attr_node_list(xfs_attr_list_context_t *context)
 219 {
 220         attrlist_cursor_kern_t *cursor;
 221         xfs_attr_leafblock_t *leaf;
 222         xfs_da_intnode_t *node;
 223         struct xfs_attr3_icleaf_hdr leafhdr;
 224         struct xfs_da3_icnode_hdr nodehdr;
 225         struct xfs_da_node_entry *btree;
 226         int error, i;
 227         struct xfs_buf *bp;
 228         struct xfs_inode        *dp = context->dp;
 229
 230         trace_xfs_attr_node_list(context);
 231
 232         cursor = context->cursor;
 233         cursor->initted = 1;
 234
 235         /*
 236          * Do all sorts of validation on the passed-in cursor structure.
 237          * If anything is amiss, ignore the cursor and look up the hashval
 238          * starting from the btree root.
 239          */
 240         bp = NULL;
 241         if (cursor->blkno > 0) {
 242                 error = xfs_da3_node_read(NULL, dp, cursor->blkno, -1,
 243                                               &bp, XFS_ATTR_FORK);
 244                 if ((error != 0) && (error != -EFSCORRUPTED))
 245                         return error;
 246                 if (bp) {
 247                         struct xfs_attr_leaf_entry *entries;
 248
 249                         node = bp->b_addr;
 250                         switch (be16_to_cpu(node->hdr.info.magic)) {
 251                         case XFS_DA_NODE_MAGIC:
 252                         case XFS_DA3_NODE_MAGIC:
 253                                 trace_xfs_attr_list_wrong_blk(context);
 254                                 xfs_trans_brelse(NULL, bp);
 255                                 bp = NULL;
 256                                 break;
 257                         case XFS_ATTR_LEAF_MAGIC:
 258                         case XFS_ATTR3_LEAF_MAGIC:
 259                                 leaf = bp->b_addr;
 260                                 xfs_attr3_leaf_hdr_from_disk(&leafhdr, leaf);
 261                                 entries = xfs_attr3_leaf_entryp(leaf);
 262                                 if (cursor->hashval > be32_to_cpu(
 263                                                 entries[leafhdr.count - 1].hashval)) {
 264                                         trace_xfs_attr_list_wrong_blk(context);
 265                                         xfs_trans_brelse(NULL, bp);
 266                                         bp = NULL;
 267                                 } else if (cursor->hashval <= be32_to_cpu(
 268                                                 entries[0].hashval)) {
 269                                         trace_xfs_attr_list_wrong_blk(context);
 270                                         xfs_trans_brelse(NULL, bp);
 271                                         bp = NULL;
 272                                 }
 273                                 break;
 274                         default:
 275                                 trace_xfs_attr_list_wrong_blk(context);
 276                                 xfs_trans_brelse(NULL, bp);
 277                                 bp = NULL;
 278                         }
 279                 }
 280         }
 281
 282         /*
 283          * We did not find what we expected given the cursor's contents,
 284          * so we start from the top and work down based on the hash value.
 285          * Note that start of node block is same as start of leaf block.
 286          */
 287         if (bp == NULL) {
 288                 cursor->blkno = 0;
 289                 for (;;) {
 290                         __uint16_t magic;
 291
 292                         error = xfs_da3_node_read(NULL, dp,
 293                                                       cursor->blkno, -1, &bp,
 294                                                       XFS_ATTR_FORK);
 295                         if (error)
 296                                 return error;
 297                         node = bp->b_addr;
 298                         magic = be16_to_cpu(node->hdr.info.magic);
 299                         if (magic == XFS_ATTR_LEAF_MAGIC ||
 300                             magic == XFS_ATTR3_LEAF_MAGIC)
 301                                 break;
 302                         if (magic != XFS_DA_NODE_MAGIC &&
 303                             magic != XFS_DA3_NODE_MAGIC) {
 304                                 XFS_CORRUPTION_ERROR("xfs_attr_node_list(3)",
 305                                                      XFS_ERRLEVEL_LOW,
 306                                                      context->dp->i_mount,
 307                                                      node);
 308                                 xfs_trans_brelse(NULL, bp);
 309                                 return -EFSCORRUPTED;
 310                         }
 311
 312                         dp->d_ops->node_hdr_from_disk(&nodehdr, node);
 313                         btree = dp->d_ops->node_tree_p(node);
 314                         for (i = 0; i < nodehdr.count; btree++, i++) {
 315                                 if (cursor->hashval
 316                                                 <= be32_to_cpu(btree->hashval)) {
 317                                         cursor->blkno = be32_to_cpu(btree->before);
 318                                         trace_xfs_attr_list_node_descend(context,
 319                                                                          btree);
 320                                         break;
 321                                 }
 322                         }
 323                         if (i == nodehdr.count) {
 324                                 xfs_trans_brelse(NULL, bp);
 325                                 return 0;
 326                         }
 327                         xfs_trans_brelse(NULL, bp);
 328                 }
 329         }
 330         ASSERT(bp != NULL);
 331
 332         /*
 333          * Roll upward through the blocks, processing each leaf block in
 334          * order.  As long as there is space in the result buffer, keep
 335          * adding the information.
 336          */
 337         for (;;) {
 338                 leaf = bp->b_addr;
 339                 error = xfs_attr3_leaf_list_int(bp, context);
 340                 if (error) {
 341                         xfs_trans_brelse(NULL, bp);
 342                         return error;
 343                 }
 344                 xfs_attr3_leaf_hdr_from_disk(&leafhdr, leaf);
 345                 if (context->seen_enough || leafhdr.forw == 0)
 346                         break;
 347                 cursor->blkno = leafhdr.forw;
 348                 xfs_trans_brelse(NULL, bp);
 349                 error = xfs_attr3_leaf_read(NULL, dp, cursor->blkno, -1, &bp);
 350                 if (error)
 351                         return error;
 352         }
 353         xfs_trans_brelse(NULL, bp);
 354         return 0;
 355 }
 356
 357 /*
 358  * Copy out attribute list entries for attr_list(), for leaf attribute lists.
 359  */
 360 int
 361 xfs_attr3_leaf_list_int(
 362         struct xfs_buf                  *bp,
 363         struct xfs_attr_list_context    *context)
 364 {
 365         struct attrlist_cursor_kern     *cursor;
 366         struct xfs_attr_leafblock       *leaf;
 367         struct xfs_attr3_icleaf_hdr     ichdr;
 368         struct xfs_attr_leaf_entry      *entries;
 369         struct xfs_attr_leaf_entry      *entry;
 370         int                             retval;
 371         int                             i;
 372
 373         trace_xfs_attr_list_leaf(context);
 374
 375         leaf = bp->b_addr;
 376         xfs_attr3_leaf_hdr_from_disk(&ichdr, leaf);
 377         entries = xfs_attr3_leaf_entryp(leaf);
 378
 379         cursor = context->cursor;
 380         cursor->initted = 1;
 381
 382         /*
 383          * Re-find our place in the leaf block if this is a new syscall.
 384          */
 385         if (context->resynch) {
 386                 entry = &entries[0];
 387                 for (i = 0; i < ichdr.count; entry++, i++) {
 388                         if (be32_to_cpu(entry->hashval) == cursor->hashval) {
 389                                 if (cursor->offset == context->dupcnt) {
 390                                         context->dupcnt = 0;
 391                                         break;
 392                                 }
 393                                 context->dupcnt++;
 394                         } else if (be32_to_cpu(entry->hashval) >
 395                                         cursor->hashval) {
 396                                 context->dupcnt = 0;
 397                                 break;
 398                         }
 399                 }
 400                 if (i == ichdr.count) {
 401                         trace_xfs_attr_list_notfound(context);
 402                         return 0;
 403                 }
 404         } else {
 405                 entry = &entries[0];
 406                 i = 0;
 407         }
 408         context->resynch = 0;
 409
 410         /*
 411          * We have found our place, start copying out the new attributes.
 412          */
 413         retval = 0;
 414         for (; i < ichdr.count; entry++, i++) {
 415                 if (be32_to_cpu(entry->hashval) != cursor->hashval) {
 416                         cursor->hashval = be32_to_cpu(entry->hashval);
 417                         cursor->offset = 0;
 418                 }
 419
 420                 if (entry->flags & XFS_ATTR_INCOMPLETE)
 421                         continue;               /* skip incomplete entries */
 422
 423                 if (entry->flags & XFS_ATTR_LOCAL) {
 424                         xfs_attr_leaf_name_local_t *name_loc =
 425                                 xfs_attr3_leaf_name_local(leaf, i);
 426
 427                         retval = context->put_listent(context,
 428                                                 entry->flags,
 429                                                 name_loc->nameval,
 430                                                 (int)name_loc->namelen,
 431                                                 be16_to_cpu(name_loc->valuelen),
 432                                                 &name_loc->nameval[name_loc->namelen]);
 433                         if (retval)
 434                                 return retval;
 435                 } else {
 436                         xfs_attr_leaf_name_remote_t *name_rmt =
 437                                 xfs_attr3_leaf_name_remote(leaf, i);
 438
 439                         int valuelen = be32_to_cpu(name_rmt->valuelen);
 440
 441                         if (context->put_value) {
 442                                 xfs_da_args_t args;
 443
 444                                 memset((char *)&args, 0, sizeof(args));
 445                                 args.geo = context->dp->i_mount->m_attr_geo;
 446                                 args.dp = context->dp;
 447                                 args.whichfork = XFS_ATTR_FORK;
 448                                 args.valuelen = valuelen;
 449                                 args.rmtvaluelen = valuelen;
 450                                 args.value = kmem_alloc(valuelen, KM_SLEEP | KM_NOFS);
 451                                 args.rmtblkno = be32_to_cpu(name_rmt->valueblk);
 452                                 args.rmtblkcnt = xfs_attr3_rmt_blocks(
 453                                                         args.dp->i_mount, valuelen);
 454                                 retval = xfs_attr_rmtval_get(&args);
 455                                 if (retval)
 456                                         return retval;
 457                                 retval = context->put_listent(context,
 458                                                 entry->flags,
 459                                                 name_rmt->name,
 460                                                 (int)name_rmt->namelen,
 461                                                 valuelen,
 462                                                 args.value);
 463                                 kmem_free(args.value);
 464                         } else {
 465                                 retval = context->put_listent(context,
 466                                                 entry->flags,
 467                                                 name_rmt->name,
 468                                                 (int)name_rmt->namelen,
 469                                                 valuelen,
 470                                                 NULL);
 471                         }
 472                         if (retval)
 473                                 return retval;
 474                 }
 475                 if (context->seen_enough)
 476                         break;
 477                 cursor->offset++;
 478         }
 479         trace_xfs_attr_list_leaf_end(context);
 480         return retval;
 481 }
 482
 483 /*
 484  * Copy out attribute entries for attr_list(), for leaf attribute lists.
 485  */
 486 STATIC int
 487 xfs_attr_leaf_list(xfs_attr_list_context_t *context)
 488 {
 489         int error;
 490         struct xfs_buf *bp;
 491
 492         trace_xfs_attr_leaf_list(context);
 493
 494         context->cursor->blkno = 0;
 495         error = xfs_attr3_leaf_read(NULL, context->dp, 0, -1, &bp);
 496         if (error)
 497                 return error;
 498
 499         error = xfs_attr3_leaf_list_int(bp, context);
 500         xfs_trans_brelse(NULL, bp);
 501         return error;
 502 }
 503
 504 int
 505 xfs_attr_list_int(
 506         xfs_attr_list_context_t *context)
 507 {
 508         int error;
 509         xfs_inode_t *dp = context->dp;
 510         uint            lock_mode;
 511
 512         XFS_STATS_INC(xs_attr_list);
 513
 514         if (XFS_FORCED_SHUTDOWN(dp->i_mount))
 515                 return -EIO;
 516
 517         /*
 518          * Decide on what work routines to call based on the inode size.
 519          */
 520         lock_mode = xfs_ilock_attr_map_shared(dp);
 521         if (!xfs_inode_hasattr(dp)) {
 522                 error = 0;
 523         } else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
 524                 error = xfs_attr_shortform_list(context);
 525         } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
 526                 error = xfs_attr_leaf_list(context);
 527         } else {
 528                 error = xfs_attr_node_list(context);
 529         }
 530         xfs_iunlock(dp, lock_mode);
 531         return error;
 532 }
 533
 534 #define ATTR_ENTBASESIZE                /* minimum bytes used by an attr */ \
 535         (((struct attrlist_ent *) 0)->a_name - (char *) 0)
 536 #define ATTR_ENTSIZE(namelen)           /* actual bytes used by an attr */ \
 537         ((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(u_int32_t)-1) \
 538          & ~(sizeof(u_int32_t)-1))
 539
 540 /*
 541  * Format an attribute and copy it out to the user's buffer.
 542  * Take care to check values and protect against them changing later,
 543  * we may be reading them directly out of a user buffer.
 544  */
 545 STATIC int
 546 xfs_attr_put_listent(
 547         xfs_attr_list_context_t *context,
 548         int             flags,
 549         unsigned char   *name,
 550         int             namelen,
 551         int             valuelen,
 552         unsigned char   *value)
 553 {
 554         struct attrlist *alist = (struct attrlist *)context->alist;
 555         attrlist_ent_t *aep;
 556         int arraytop;
 557
 558         ASSERT(!(context->flags & ATTR_KERNOVAL));
 559         ASSERT(context->count >= 0);
 560         ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
 561         ASSERT(context->firstu >= sizeof(*alist));
 562         ASSERT(context->firstu <= context->bufsize);
 563
 564         /*
 565          * Only list entries in the right namespace.
 566          */
 567         if (((context->flags & ATTR_SECURE) == 0) !=
 568             ((flags & XFS_ATTR_SECURE) == 0))
 569                 return 0;
 570         if (((context->flags & ATTR_ROOT) == 0) !=
 571             ((flags & XFS_ATTR_ROOT) == 0))
 572                 return 0;
 573
 574         arraytop = sizeof(*alist) +
 575                         context->count * sizeof(alist->al_offset[0]);
 576         context->firstu -= ATTR_ENTSIZE(namelen);
 577         if (context->firstu < arraytop) {
 578                 trace_xfs_attr_list_full(context);
 579                 alist->al_more = 1;
 580                 context->seen_enough = 1;
 581                 return 1;
 582         }
 583
 584         aep = (attrlist_ent_t *)&context->alist[context->firstu];
 585         aep->a_valuelen = valuelen;
 586         memcpy(aep->a_name, name, namelen);
 587         aep->a_name[namelen] = 0;
 588         alist->al_offset[context->count++] = context->firstu;
 589         alist->al_count = context->count;
 590         trace_xfs_attr_list_add(context);
 591         return 0;
 592 }
 593
 594 /*
 595  * Generate a list of extended attribute names and optionally
 596  * also value lengths.  Positive return value follows the XFS
 597  * convention of being an error, zero or negative return code
 598  * is the length of the buffer returned (negated), indicating
 599  * success.
 600  */
 601 int
 602 xfs_attr_list(
 603         xfs_inode_t     *dp,
 604         char            *buffer,
 605         int             bufsize,
 606         int             flags,
 607         attrlist_cursor_kern_t *cursor)
 608 {
 609         xfs_attr_list_context_t context;
 610         struct attrlist *alist;
 611         int error;
 612
 613         /*
 614          * Validate the cursor.
 615          */
 616         if (cursor->pad1 || cursor->pad2)
 617                 return -EINVAL;
 618         if ((cursor->initted == 0) &&
 619             (cursor->hashval || cursor->blkno || cursor->offset))
 620                 return -EINVAL;
 621
 622         /*
 623          * Check for a properly aligned buffer.
 624          */
 625         if (((long)buffer) & (sizeof(int)-1))
 626                 return -EFAULT;
 627         if (flags & ATTR_KERNOVAL)
 628                 bufsize = 0;
 629
 630         /*
 631          * Initialize the output buffer.
 632          */
 633         memset(&context, 0, sizeof(context));
 634         context.dp = dp;
 635         context.cursor = cursor;
 636         context.resynch = 1;
 637         context.flags = flags;
 638         context.alist = buffer;
 639         context.bufsize = (bufsize & ~(sizeof(int)-1));  /* align */
 640         context.firstu = context.bufsize;
 641         context.put_listent = xfs_attr_put_listent;
 642
 643         alist = (struct attrlist *)context.alist;
 644         alist->al_count = 0;
 645         alist->al_more = 0;
 646         alist->al_offset[0] = context.bufsize;
 647
 648         error = xfs_attr_list_int(&context);
 649         ASSERT(error <= 0);
 650         return error;
 651 }