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