fs/xfs/xfs_attr_list.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   4  * Copyright (c) 2013 Red Hat, Inc.
   5  * All Rights Reserved.
   6  */
   7 #include "xfs.h"
   8 #include "xfs_fs.h"
   9 #include "xfs_shared.h"
  10 #include "xfs_format.h"
  11 #include "xfs_log_format.h"
  12 #include "xfs_trans_resv.h"
  13 #include "xfs_mount.h"
  14 #include "xfs_da_format.h"
  15 #include "xfs_inode.h"
  16 #include "xfs_trans.h"
  17 #include "xfs_bmap.h"
  18 #include "xfs_da_btree.h"
  19 #include "xfs_attr.h"
  20 #include "xfs_attr_sf.h"
  21 #include "xfs_attr_leaf.h"
  22 #include "xfs_error.h"
  23 #include "xfs_trace.h"
  24 #include "xfs_dir2.h"
  25 #include "xfs_health.h"
  26
  27 STATIC int
  28 xfs_attr_shortform_compare(const void *a, const void *b)
  29 {
  30         xfs_attr_sf_sort_t *sa, *sb;
  31
  32         sa = (xfs_attr_sf_sort_t *)a;
  33         sb = (xfs_attr_sf_sort_t *)b;
  34         if (sa->hash < sb->hash) {
  35                 return -1;
  36         } else if (sa->hash > sb->hash) {
  37                 return 1;
  38         } else {
  39                 return sa->entno - sb->entno;
  40         }
  41 }
  42
  43 #define XFS_ISRESET_CURSOR(cursor) \
  44         (!((cursor)->initted) && !((cursor)->hashval) && \
  45          !((cursor)->blkno) && !((cursor)->offset))
  46 /*
  47  * Copy out entries of shortform attribute lists for attr_list().
  48  * Shortform attribute lists are not stored in hashval sorted order.
  49  * If the output buffer is not large enough to hold them all, then
  50  * we have to calculate each entries' hashvalue and sort them before
  51  * we can begin returning them to the user.
  52  */
  53 static int
  54 xfs_attr_shortform_list(
  55         struct xfs_attr_list_context    *context)
  56 {
  57         struct xfs_attrlist_cursor_kern *cursor = &context->cursor;
  58         struct xfs_inode                *dp = context->dp;
  59         struct xfs_attr_sf_sort         *sbuf, *sbp;
  60         struct xfs_attr_sf_hdr          *sf = dp->i_af.if_data;
  61         struct xfs_attr_sf_entry        *sfe;
  62         int                             sbsize, nsbuf, count, i;
  63         int                             error = 0;
  64
  65         ASSERT(sf != NULL);
  66         if (!sf->count)
  67                 return 0;
  68
  69         trace_xfs_attr_list_sf(context);
  70
  71         /*
  72          * If the buffer is large enough and the cursor is at the start,
  73          * do not bother with sorting since we will return everything in
  74          * one buffer and another call using the cursor won't need to be
  75          * made.
  76          * Note the generous fudge factor of 16 overhead bytes per entry.
  77          * If bufsize is zero then put_listent must be a search function
  78          * and can just scan through what we have.
  79          */
  80         if (context->bufsize == 0 ||
  81             (XFS_ISRESET_CURSOR(cursor) &&
  82              (dp->i_af.if_bytes + sf->count * 16) < context->bufsize)) {
  83                 for (i = 0, sfe = xfs_attr_sf_firstentry(sf); i < sf->count; i++) {
  84                         if (XFS_IS_CORRUPT(context->dp->i_mount,
  85                                            !xfs_attr_namecheck(sfe->nameval,
  86                                                                sfe->namelen))) {
  87                                 xfs_dirattr_mark_sick(context->dp, XFS_ATTR_FORK);
  88                                 return -EFSCORRUPTED;
  89                         }
  90                         context->put_listent(context,
  91                                              sfe->flags,
  92                                              sfe->nameval,
  93                                              (int)sfe->namelen,
  94                                              (int)sfe->valuelen);
  95                         /*
  96                          * Either search callback finished early or
  97                          * didn't fit it all in the buffer after all.
  98                          */
  99                         if (context->seen_enough)
 100                                 break;
 101                         sfe = xfs_attr_sf_nextentry(sfe);
 102                 }
 103                 trace_xfs_attr_list_sf_all(context);
 104                 return 0;
 105         }
 106
 107         /* do no more for a search callback */
 108         if (context->bufsize == 0)
 109                 return 0;
 110
 111         /*
 112          * It didn't all fit, so we have to sort everything on hashval.
 113          */
 114         sbsize = sf->count * sizeof(*sbuf);
 115         sbp = sbuf = kmalloc(sbsize, GFP_KERNEL | __GFP_NOFAIL);
 116
 117         /*
 118          * Scan the attribute list for the rest of the entries, storing
 119          * the relevant info from only those that match into a buffer.
 120          */
 121         nsbuf = 0;
 122         for (i = 0, sfe = xfs_attr_sf_firstentry(sf); i < sf->count; i++) {
 123                 if (unlikely(
 124                     ((char *)sfe < (char *)sf) ||
 125                     ((char *)sfe >= ((char *)sf + dp->i_af.if_bytes)))) {
 126                         XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
 127                                              XFS_ERRLEVEL_LOW,
 128                                              context->dp->i_mount, sfe,
 129                                              sizeof(*sfe));
 130                         kfree(sbuf);
 131                         xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
 132                         return -EFSCORRUPTED;
 133                 }
 134
 135                 sbp->entno = i;
 136                 sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
 137                 sbp->name = sfe->nameval;
 138                 sbp->namelen = sfe->namelen;
 139                 /* These are bytes, and both on-disk, don't endian-flip */
 140                 sbp->valuelen = sfe->valuelen;
 141                 sbp->flags = sfe->flags;
 142                 sfe = xfs_attr_sf_nextentry(sfe);
 143                 sbp++;
 144                 nsbuf++;
 145         }
 146
 147         /*
 148          * Sort the entries on hash then entno.
 149          */
 150         xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
 151
 152         /*
 153          * Re-find our place IN THE SORTED LIST.
 154          */
 155         count = 0;
 156         cursor->initted = 1;
 157         cursor->blkno = 0;
 158         for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
 159                 if (sbp->hash == cursor->hashval) {
 160                         if (cursor->offset == count) {
 161                                 break;
 162                         }
 163                         count++;
 164                 } else if (sbp->hash > cursor->hashval) {
 165                         break;
 166                 }
 167         }
 168         if (i == nsbuf)
 169                 goto out;
 170
 171         /*
 172          * Loop putting entries into the user buffer.
 173          */
 174         for ( ; i < nsbuf; i++, sbp++) {
 175                 if (cursor->hashval != sbp->hash) {
 176                         cursor->hashval = sbp->hash;
 177                         cursor->offset = 0;
 178                 }
 179                 if (XFS_IS_CORRUPT(context->dp->i_mount,
 180                                    !xfs_attr_namecheck(sbp->name,
 181                                                        sbp->namelen))) {
 182                         xfs_dirattr_mark_sick(context->dp, XFS_ATTR_FORK);
 183                         error = -EFSCORRUPTED;
 184                         goto out;
 185                 }
 186                 context->put_listent(context,
 187                                      sbp->flags,
 188                                      sbp->name,
 189                                      sbp->namelen,
 190                                      sbp->valuelen);
 191                 if (context->seen_enough)
 192                         break;
 193                 cursor->offset++;
 194         }
 195 out:
 196         kfree(sbuf);
 197         return error;
 198 }
 199
 200 /*
 201  * We didn't find the block & hash mentioned in the cursor state, so
 202  * walk down the attr btree looking for the hash.
 203  */
 204 STATIC int
 205 xfs_attr_node_list_lookup(
 206         struct xfs_attr_list_context    *context,
 207         struct xfs_attrlist_cursor_kern *cursor,
 208         struct xfs_buf                  **pbp)
 209 {
 210         struct xfs_da3_icnode_hdr       nodehdr;
 211         struct xfs_da_intnode           *node;
 212         struct xfs_da_node_entry        *btree;
 213         struct xfs_inode                *dp = context->dp;
 214         struct xfs_mount                *mp = dp->i_mount;
 215         struct xfs_trans                *tp = context->tp;
 216         struct xfs_buf                  *bp;
 217         int                             i;
 218         int                             error = 0;
 219         unsigned int                    expected_level = 0;
 220         uint16_t                        magic;
 221
 222         ASSERT(*pbp == NULL);
 223         cursor->blkno = 0;
 224         for (;;) {
 225                 error = xfs_da3_node_read(tp, dp, cursor->blkno, &bp,
 226                                 XFS_ATTR_FORK);
 227                 if (error)
 228                         return error;
 229                 node = bp->b_addr;
 230                 magic = be16_to_cpu(node->hdr.info.magic);
 231                 if (magic == XFS_ATTR_LEAF_MAGIC ||
 232                     magic == XFS_ATTR3_LEAF_MAGIC)
 233                         break;
 234                 if (magic != XFS_DA_NODE_MAGIC &&
 235                     magic != XFS_DA3_NODE_MAGIC) {
 236                         XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
 237                                         node, sizeof(*node));
 238                         goto out_corruptbuf;
 239                 }
 240
 241                 xfs_da3_node_hdr_from_disk(mp, &nodehdr, node);
 242
 243                 /* Tree taller than we can handle; bail out! */
 244                 if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
 245                         goto out_corruptbuf;
 246
 247                 /* Check the level from the root node. */
 248                 if (cursor->blkno == 0)
 249                         expected_level = nodehdr.level - 1;
 250                 else if (expected_level != nodehdr.level)
 251                         goto out_corruptbuf;
 252                 else
 253                         expected_level--;
 254
 255                 btree = nodehdr.btree;
 256                 for (i = 0; i < nodehdr.count; btree++, i++) {
 257                         if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
 258                                 cursor->blkno = be32_to_cpu(btree->before);
 259                                 trace_xfs_attr_list_node_descend(context,
 260                                                 btree);
 261                                 break;
 262                         }
 263                 }
 264                 xfs_trans_brelse(tp, bp);
 265
 266                 if (i == nodehdr.count)
 267                         return 0;
 268
 269                 /* We can't point back to the root. */
 270                 if (XFS_IS_CORRUPT(mp, cursor->blkno == 0)) {
 271                         xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
 272                         return -EFSCORRUPTED;
 273                 }
 274         }
 275
 276         if (expected_level != 0)
 277                 goto out_corruptbuf;
 278
 279         *pbp = bp;
 280         return 0;
 281
 282 out_corruptbuf:
 283         xfs_buf_mark_corrupt(bp);
 284         xfs_trans_brelse(tp, bp);
 285         xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
 286         return -EFSCORRUPTED;
 287 }
 288
 289 STATIC int
 290 xfs_attr_node_list(
 291         struct xfs_attr_list_context    *context)
 292 {
 293         struct xfs_attrlist_cursor_kern *cursor = &context->cursor;
 294         struct xfs_attr3_icleaf_hdr     leafhdr;
 295         struct xfs_attr_leafblock       *leaf;
 296         struct xfs_da_intnode           *node;
 297         struct xfs_buf                  *bp;
 298         struct xfs_inode                *dp = context->dp;
 299         struct xfs_mount                *mp = dp->i_mount;
 300         int                             error = 0;
 301
 302         trace_xfs_attr_node_list(context);
 303
 304         cursor->initted = 1;
 305
 306         /*
 307          * Do all sorts of validation on the passed-in cursor structure.
 308          * If anything is amiss, ignore the cursor and look up the hashval
 309          * starting from the btree root.
 310          */
 311         bp = NULL;
 312         if (cursor->blkno > 0) {
 313                 error = xfs_da3_node_read(context->tp, dp, cursor->blkno, &bp,
 314                                 XFS_ATTR_FORK);
 315                 if (xfs_metadata_is_sick(error))
 316                         xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
 317                 if ((error != 0) && (error != -EFSCORRUPTED))
 318                         return error;
 319                 if (bp) {
 320                         struct xfs_attr_leaf_entry *entries;
 321
 322                         node = bp->b_addr;
 323                         switch (be16_to_cpu(node->hdr.info.magic)) {
 324                         case XFS_DA_NODE_MAGIC:
 325                         case XFS_DA3_NODE_MAGIC:
 326                                 trace_xfs_attr_list_wrong_blk(context);
 327                                 xfs_trans_brelse(context->tp, bp);
 328                                 bp = NULL;
 329                                 break;
 330                         case XFS_ATTR_LEAF_MAGIC:
 331                         case XFS_ATTR3_LEAF_MAGIC:
 332                                 leaf = bp->b_addr;
 333                                 xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
 334                                                              &leafhdr, leaf);
 335                                 entries = xfs_attr3_leaf_entryp(leaf);
 336                                 if (cursor->hashval > be32_to_cpu(
 337                                                 entries[leafhdr.count - 1].hashval)) {
 338                                         trace_xfs_attr_list_wrong_blk(context);
 339                                         xfs_trans_brelse(context->tp, bp);
 340                                         bp = NULL;
 341                                 } else if (cursor->hashval <= be32_to_cpu(
 342                                                 entries[0].hashval)) {
 343                                         trace_xfs_attr_list_wrong_blk(context);
 344                                         xfs_trans_brelse(context->tp, bp);
 345                                         bp = NULL;
 346                                 }
 347                                 break;
 348                         default:
 349                                 trace_xfs_attr_list_wrong_blk(context);
 350                                 xfs_trans_brelse(context->tp, bp);
 351                                 bp = NULL;
 352                         }
 353                 }
 354         }
 355
 356         /*
 357          * We did not find what we expected given the cursor's contents,
 358          * so we start from the top and work down based on the hash value.
 359          * Note that start of node block is same as start of leaf block.
 360          */
 361         if (bp == NULL) {
 362                 error = xfs_attr_node_list_lookup(context, cursor, &bp);
 363                 if (error || !bp)
 364                         return error;
 365         }
 366         ASSERT(bp != NULL);
 367
 368         /*
 369          * Roll upward through the blocks, processing each leaf block in
 370          * order.  As long as there is space in the result buffer, keep
 371          * adding the information.
 372          */
 373         for (;;) {
 374                 leaf = bp->b_addr;
 375                 error = xfs_attr3_leaf_list_int(bp, context);
 376                 if (error)
 377                         break;
 378                 xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
 379                 if (context->seen_enough || leafhdr.forw == 0)
 380                         break;
 381                 cursor->blkno = leafhdr.forw;
 382                 xfs_trans_brelse(context->tp, bp);
 383                 error = xfs_attr3_leaf_read(context->tp, dp, cursor->blkno,
 384                                             &bp);
 385                 if (error)
 386                         return error;
 387         }
 388         xfs_trans_brelse(context->tp, bp);
 389         return error;
 390 }
 391
 392 /*
 393  * Copy out attribute list entries for attr_list(), for leaf attribute lists.
 394  */
 395 int
 396 xfs_attr3_leaf_list_int(
 397         struct xfs_buf                  *bp,
 398         struct xfs_attr_list_context    *context)
 399 {
 400         struct xfs_attrlist_cursor_kern *cursor = &context->cursor;
 401         struct xfs_attr_leafblock       *leaf;
 402         struct xfs_attr3_icleaf_hdr     ichdr;
 403         struct xfs_attr_leaf_entry      *entries;
 404         struct xfs_attr_leaf_entry      *entry;
 405         int                             i;
 406         struct xfs_mount                *mp = context->dp->i_mount;
 407
 408         trace_xfs_attr_list_leaf(context);
 409
 410         leaf = bp->b_addr;
 411         xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
 412         entries = xfs_attr3_leaf_entryp(leaf);
 413
 414         cursor->initted = 1;
 415
 416         /*
 417          * Re-find our place in the leaf block if this is a new syscall.
 418          */
 419         if (context->resynch) {
 420                 entry = &entries[0];
 421                 for (i = 0; i < ichdr.count; entry++, i++) {
 422                         if (be32_to_cpu(entry->hashval) == cursor->hashval) {
 423                                 if (cursor->offset == context->dupcnt) {
 424                                         context->dupcnt = 0;
 425                                         break;
 426                                 }
 427                                 context->dupcnt++;
 428                         } else if (be32_to_cpu(entry->hashval) >
 429                                         cursor->hashval) {
 430                                 context->dupcnt = 0;
 431                                 break;
 432                         }
 433                 }
 434                 if (i == ichdr.count) {
 435                         trace_xfs_attr_list_notfound(context);
 436                         return 0;
 437                 }
 438         } else {
 439                 entry = &entries[0];
 440                 i = 0;
 441         }
 442         context->resynch = 0;
 443
 444         /*
 445          * We have found our place, start copying out the new attributes.
 446          */
 447         for (; i < ichdr.count; entry++, i++) {
 448                 char *name;
 449                 int namelen, valuelen;
 450
 451                 if (be32_to_cpu(entry->hashval) != cursor->hashval) {
 452                         cursor->hashval = be32_to_cpu(entry->hashval);
 453                         cursor->offset = 0;
 454                 }
 455
 456                 if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
 457                     !context->allow_incomplete)
 458                         continue;
 459
 460                 if (entry->flags & XFS_ATTR_LOCAL) {
 461                         xfs_attr_leaf_name_local_t *name_loc;
 462
 463                         name_loc = xfs_attr3_leaf_name_local(leaf, i);
 464                         name = name_loc->nameval;
 465                         namelen = name_loc->namelen;
 466                         valuelen = be16_to_cpu(name_loc->valuelen);
 467                 } else {
 468                         xfs_attr_leaf_name_remote_t *name_rmt;
 469
 470                         name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
 471                         name = name_rmt->name;
 472                         namelen = name_rmt->namelen;
 473                         valuelen = be32_to_cpu(name_rmt->valuelen);
 474                 }
 475
 476                 if (XFS_IS_CORRUPT(context->dp->i_mount,
 477                                    !xfs_attr_namecheck(name, namelen))) {
 478                         xfs_dirattr_mark_sick(context->dp, XFS_ATTR_FORK);
 479                         return -EFSCORRUPTED;
 480                 }
 481                 context->put_listent(context, entry->flags,
 482                                               name, namelen, valuelen);
 483                 if (context->seen_enough)
 484                         break;
 485                 cursor->offset++;
 486         }
 487         trace_xfs_attr_list_leaf_end(context);
 488         return 0;
 489 }
 490
 491 /*
 492  * Copy out attribute entries for attr_list(), for leaf attribute lists.
 493  */
 494 STATIC int
 495 xfs_attr_leaf_list(
 496         struct xfs_attr_list_context    *context)
 497 {
 498         struct xfs_buf                  *bp;
 499         int                             error;
 500
 501         trace_xfs_attr_leaf_list(context);
 502
 503         context->cursor.blkno = 0;
 504         error = xfs_attr3_leaf_read(context->tp, context->dp, 0, &bp);
 505         if (error)
 506                 return error;
 507
 508         error = xfs_attr3_leaf_list_int(bp, context);
 509         xfs_trans_brelse(context->tp, bp);
 510         return error;
 511 }
 512
 513 int
 514 xfs_attr_list_ilocked(
 515         struct xfs_attr_list_context    *context)
 516 {
 517         struct xfs_inode                *dp = context->dp;
 518
 519         xfs_assert_ilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL);
 520
 521         /*
 522          * Decide on what work routines to call based on the inode size.
 523          */
 524         if (!xfs_inode_hasattr(dp))
 525                 return 0;
 526         if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
 527                 return xfs_attr_shortform_list(context);
 528         if (xfs_attr_is_leaf(dp))
 529                 return xfs_attr_leaf_list(context);
 530         return xfs_attr_node_list(context);
 531 }
 532
 533 int
 534 xfs_attr_list(
 535         struct xfs_attr_list_context    *context)
 536 {
 537         struct xfs_inode                *dp = context->dp;
 538         uint                            lock_mode;
 539         int                             error;
 540
 541         XFS_STATS_INC(dp->i_mount, xs_attr_list);
 542
 543         if (xfs_is_shutdown(dp->i_mount))
 544                 return -EIO;
 545
 546         lock_mode = xfs_ilock_attr_map_shared(dp);
 547         error = xfs_attr_list_ilocked(context);
 548         xfs_iunlock(dp, lock_mode);
 549         return error;
 550 }