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_attr.h"
  19 #include "xfs_attr_sf.h"
  20 #include "xfs_attr_leaf.h"
  21 #include "xfs_error.h"
  22 #include "xfs_trace.h"
  23 #include "xfs_dir2.h"
  24
  25 STATIC int
  26 xfs_attr_shortform_compare(const void *a, const void *b)
  27 {
  28         xfs_attr_sf_sort_t *sa, *sb;
  29
  30         sa = (xfs_attr_sf_sort_t *)a;
  31         sb = (xfs_attr_sf_sort_t *)b;
  32         if (sa->hash < sb->hash) {
  33                 return -1;
  34         } else if (sa->hash > sb->hash) {
  35                 return 1;
  36         } else {
  37                 return sa->entno - sb->entno;
  38         }
  39 }
  40
  41 #define XFS_ISRESET_CURSOR(cursor) \
  42         (!((cursor)->initted) && !((cursor)->hashval) && \
  43          !((cursor)->blkno) && !((cursor)->offset))
  44 /*
  45  * Copy out entries of shortform attribute lists for attr_list().
  46  * Shortform attribute lists are not stored in hashval sorted order.
  47  * If the output buffer is not large enough to hold them all, then
  48  * we have to calculate each entries' hashvalue and sort them before
  49  * we can begin returning them to the user.
  50  */
  51 static int
  52 xfs_attr_shortform_list(
  53         struct xfs_attr_list_context    *context)
  54 {
  55         struct xfs_attrlist_cursor_kern *cursor = &context->cursor;
  56         struct xfs_inode                *dp = context->dp;
  57         struct xfs_attr_sf_sort         *sbuf, *sbp;
  58         struct xfs_attr_shortform       *sf;
  59         struct xfs_attr_sf_entry        *sfe;
  60         int                             sbsize, nsbuf, count, i;
  61         int                             error = 0;
  62
  63         ASSERT(dp->i_afp != NULL);
  64         sf = (struct xfs_attr_shortform *)dp->i_afp->if_u1.if_data;
  65         ASSERT(sf != NULL);
  66         if (!sf->hdr.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_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
  83                 for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
  84                         if (XFS_IS_CORRUPT(context->dp->i_mount,
  85                                            !xfs_attr_namecheck(sfe->nameval,
  86                                                                sfe->namelen)))
  87                                 return -EFSCORRUPTED;
  88                         context->put_listent(context,
  89                                              sfe->flags,
  90                                              sfe->nameval,
  91                                              (int)sfe->namelen,
  92                                              (int)sfe->valuelen);
  93                         /*
  94                          * Either search callback finished early or
  95                          * didn't fit it all in the buffer after all.
  96                          */
  97                         if (context->seen_enough)
  98                                 break;
  99                         sfe = xfs_attr_sf_nextentry(sfe);
 100                 }
 101                 trace_xfs_attr_list_sf_all(context);
 102                 return 0;
 103         }
 104
 105         /* do no more for a search callback */
 106         if (context->bufsize == 0)
 107                 return 0;
 108
 109         /*
 110          * It didn't all fit, so we have to sort everything on hashval.
 111          */
 112         sbsize = sf->hdr.count * sizeof(*sbuf);
 113         sbp = sbuf = kmem_alloc(sbsize, KM_NOFS);
 114
 115         /*
 116          * Scan the attribute list for the rest of the entries, storing
 117          * the relevant info from only those that match into a buffer.
 118          */
 119         nsbuf = 0;
 120         for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
 121                 if (unlikely(
 122                     ((char *)sfe < (char *)sf) ||
 123                     ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
 124                         XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
 125                                              XFS_ERRLEVEL_LOW,
 126                                              context->dp->i_mount, sfe,
 127                                              sizeof(*sfe));
 128                         kmem_free(sbuf);
 129                         return -EFSCORRUPTED;
 130                 }
 131
 132                 sbp->entno = i;
 133                 sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
 134                 sbp->name = sfe->nameval;
 135                 sbp->namelen = sfe->namelen;
 136                 /* These are bytes, and both on-disk, don't endian-flip */
 137                 sbp->valuelen = sfe->valuelen;
 138                 sbp->flags = sfe->flags;
 139                 sfe = xfs_attr_sf_nextentry(sfe);
 140                 sbp++;
 141                 nsbuf++;
 142         }
 143
 144         /*
 145          * Sort the entries on hash then entno.
 146          */
 147         xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
 148
 149         /*
 150          * Re-find our place IN THE SORTED LIST.
 151          */
 152         count = 0;
 153         cursor->initted = 1;
 154         cursor->blkno = 0;
 155         for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
 156                 if (sbp->hash == cursor->hashval) {
 157                         if (cursor->offset == count) {
 158                                 break;
 159                         }
 160                         count++;
 161                 } else if (sbp->hash > cursor->hashval) {
 162                         break;
 163                 }
 164         }
 165         if (i == nsbuf)
 166                 goto out;
 167
 168         /*
 169          * Loop putting entries into the user buffer.
 170          */
 171         for ( ; i < nsbuf; i++, sbp++) {
 172                 if (cursor->hashval != sbp->hash) {
 173                         cursor->hashval = sbp->hash;
 174                         cursor->offset = 0;
 175                 }
 176                 if (XFS_IS_CORRUPT(context->dp->i_mount,
 177                                    !xfs_attr_namecheck(sbp->name,
 178                                                        sbp->namelen))) {
 179                         error = -EFSCORRUPTED;
 180                         goto out;
 181                 }
 182                 context->put_listent(context,
 183                                      sbp->flags,
 184                                      sbp->name,
 185                                      sbp->namelen,
 186                                      sbp->valuelen);
 187                 if (context->seen_enough)
 188                         break;
 189                 cursor->offset++;
 190         }
 191 out:
 192         kmem_free(sbuf);
 193         return error;
 194 }
 195
 196 /*
 197  * We didn't find the block & hash mentioned in the cursor state, so
 198  * walk down the attr btree looking for the hash.
 199  */
 200 STATIC int
 201 xfs_attr_node_list_lookup(
 202         struct xfs_attr_list_context    *context,
 203         struct xfs_attrlist_cursor_kern *cursor,
 204         struct xfs_buf                  **pbp)
 205 {
 206         struct xfs_da3_icnode_hdr       nodehdr;
 207         struct xfs_da_intnode           *node;
 208         struct xfs_da_node_entry        *btree;
 209         struct xfs_inode                *dp = context->dp;
 210         struct xfs_mount                *mp = dp->i_mount;
 211         struct xfs_trans                *tp = context->tp;
 212         struct xfs_buf                  *bp;
 213         int                             i;
 214         int                             error = 0;
 215         unsigned int                    expected_level = 0;
 216         uint16_t                        magic;
 217
 218         ASSERT(*pbp == NULL);
 219         cursor->blkno = 0;
 220         for (;;) {
 221                 error = xfs_da3_node_read(tp, dp, cursor->blkno, &bp,
 222                                 XFS_ATTR_FORK);
 223                 if (error)
 224                         return error;
 225                 node = bp->b_addr;
 226                 magic = be16_to_cpu(node->hdr.info.magic);
 227                 if (magic == XFS_ATTR_LEAF_MAGIC ||
 228                     magic == XFS_ATTR3_LEAF_MAGIC)
 229                         break;
 230                 if (magic != XFS_DA_NODE_MAGIC &&
 231                     magic != XFS_DA3_NODE_MAGIC) {
 232                         XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
 233                                         node, sizeof(*node));
 234                         goto out_corruptbuf;
 235                 }
 236
 237                 xfs_da3_node_hdr_from_disk(mp, &nodehdr, node);
 238
 239                 /* Tree taller than we can handle; bail out! */
 240                 if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
 241                         goto out_corruptbuf;
 242
 243                 /* Check the level from the root node. */
 244                 if (cursor->blkno == 0)
 245                         expected_level = nodehdr.level - 1;
 246                 else if (expected_level != nodehdr.level)
 247                         goto out_corruptbuf;
 248                 else
 249                         expected_level--;
 250
 251                 btree = nodehdr.btree;
 252                 for (i = 0; i < nodehdr.count; btree++, i++) {
 253                         if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
 254                                 cursor->blkno = be32_to_cpu(btree->before);
 255                                 trace_xfs_attr_list_node_descend(context,
 256                                                 btree);
 257                                 break;
 258                         }
 259                 }
 260                 xfs_trans_brelse(tp, bp);
 261
 262                 if (i == nodehdr.count)
 263                         return 0;
 264
 265                 /* We can't point back to the root. */
 266                 if (XFS_IS_CORRUPT(mp, cursor->blkno == 0))
 267                         return -EFSCORRUPTED;
 268         }
 269
 270         if (expected_level != 0)
 271                 goto out_corruptbuf;
 272
 273         *pbp = bp;
 274         return 0;
 275
 276 out_corruptbuf:
 277         xfs_buf_mark_corrupt(bp);
 278         xfs_trans_brelse(tp, bp);
 279         return -EFSCORRUPTED;
 280 }
 281
 282 STATIC int
 283 xfs_attr_node_list(
 284         struct xfs_attr_list_context    *context)
 285 {
 286         struct xfs_attrlist_cursor_kern *cursor = &context->cursor;
 287         struct xfs_attr3_icleaf_hdr     leafhdr;
 288         struct xfs_attr_leafblock       *leaf;
 289         struct xfs_da_intnode           *node;
 290         struct xfs_buf                  *bp;
 291         struct xfs_inode                *dp = context->dp;
 292         struct xfs_mount                *mp = dp->i_mount;
 293         int                             error = 0;
 294
 295         trace_xfs_attr_node_list(context);
 296
 297         cursor->initted = 1;
 298
 299         /*
 300          * Do all sorts of validation on the passed-in cursor structure.
 301          * If anything is amiss, ignore the cursor and look up the hashval
 302          * starting from the btree root.
 303          */
 304         bp = NULL;
 305         if (cursor->blkno > 0) {
 306                 error = xfs_da3_node_read(context->tp, dp, cursor->blkno, &bp,
 307                                 XFS_ATTR_FORK);
 308                 if ((error != 0) && (error != -EFSCORRUPTED))
 309                         return error;
 310                 if (bp) {
 311                         struct xfs_attr_leaf_entry *entries;
 312
 313                         node = bp->b_addr;
 314                         switch (be16_to_cpu(node->hdr.info.magic)) {
 315                         case XFS_DA_NODE_MAGIC:
 316                         case XFS_DA3_NODE_MAGIC:
 317                                 trace_xfs_attr_list_wrong_blk(context);
 318                                 xfs_trans_brelse(context->tp, bp);
 319                                 bp = NULL;
 320                                 break;
 321                         case XFS_ATTR_LEAF_MAGIC:
 322                         case XFS_ATTR3_LEAF_MAGIC:
 323                                 leaf = bp->b_addr;
 324                                 xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
 325                                                              &leafhdr, leaf);
 326                                 entries = xfs_attr3_leaf_entryp(leaf);
 327                                 if (cursor->hashval > be32_to_cpu(
 328                                                 entries[leafhdr.count - 1].hashval)) {
 329                                         trace_xfs_attr_list_wrong_blk(context);
 330                                         xfs_trans_brelse(context->tp, bp);
 331                                         bp = NULL;
 332                                 } else if (cursor->hashval <= be32_to_cpu(
 333                                                 entries[0].hashval)) {
 334                                         trace_xfs_attr_list_wrong_blk(context);
 335                                         xfs_trans_brelse(context->tp, bp);
 336                                         bp = NULL;
 337                                 }
 338                                 break;
 339                         default:
 340                                 trace_xfs_attr_list_wrong_blk(context);
 341                                 xfs_trans_brelse(context->tp, bp);
 342                                 bp = NULL;
 343                         }
 344                 }
 345         }
 346
 347         /*
 348          * We did not find what we expected given the cursor's contents,
 349          * so we start from the top and work down based on the hash value.
 350          * Note that start of node block is same as start of leaf block.
 351          */
 352         if (bp == NULL) {
 353                 error = xfs_attr_node_list_lookup(context, cursor, &bp);
 354                 if (error || !bp)
 355                         return error;
 356         }
 357         ASSERT(bp != NULL);
 358
 359         /*
 360          * Roll upward through the blocks, processing each leaf block in
 361          * order.  As long as there is space in the result buffer, keep
 362          * adding the information.
 363          */
 364         for (;;) {
 365                 leaf = bp->b_addr;
 366                 error = xfs_attr3_leaf_list_int(bp, context);
 367                 if (error)
 368                         break;
 369                 xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
 370                 if (context->seen_enough || leafhdr.forw == 0)
 371                         break;
 372                 cursor->blkno = leafhdr.forw;
 373                 xfs_trans_brelse(context->tp, bp);
 374                 error = xfs_attr3_leaf_read(context->tp, dp, cursor->blkno,
 375                                             &bp);
 376                 if (error)
 377                         return error;
 378         }
 379         xfs_trans_brelse(context->tp, bp);
 380         return error;
 381 }
 382
 383 /*
 384  * Copy out attribute list entries for attr_list(), for leaf attribute lists.
 385  */
 386 int
 387 xfs_attr3_leaf_list_int(
 388         struct xfs_buf                  *bp,
 389         struct xfs_attr_list_context    *context)
 390 {
 391         struct xfs_attrlist_cursor_kern *cursor = &context->cursor;
 392         struct xfs_attr_leafblock       *leaf;
 393         struct xfs_attr3_icleaf_hdr     ichdr;
 394         struct xfs_attr_leaf_entry      *entries;
 395         struct xfs_attr_leaf_entry      *entry;
 396         int                             i;
 397         struct xfs_mount                *mp = context->dp->i_mount;
 398
 399         trace_xfs_attr_list_leaf(context);
 400
 401         leaf = bp->b_addr;
 402         xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
 403         entries = xfs_attr3_leaf_entryp(leaf);
 404
 405         cursor->initted = 1;
 406
 407         /*
 408          * Re-find our place in the leaf block if this is a new syscall.
 409          */
 410         if (context->resynch) {
 411                 entry = &entries[0];
 412                 for (i = 0; i < ichdr.count; entry++, i++) {
 413                         if (be32_to_cpu(entry->hashval) == cursor->hashval) {
 414                                 if (cursor->offset == context->dupcnt) {
 415                                         context->dupcnt = 0;
 416                                         break;
 417                                 }
 418                                 context->dupcnt++;
 419                         } else if (be32_to_cpu(entry->hashval) >
 420                                         cursor->hashval) {
 421                                 context->dupcnt = 0;
 422                                 break;
 423                         }
 424                 }
 425                 if (i == ichdr.count) {
 426                         trace_xfs_attr_list_notfound(context);
 427                         return 0;
 428                 }
 429         } else {
 430                 entry = &entries[0];
 431                 i = 0;
 432         }
 433         context->resynch = 0;
 434
 435         /*
 436          * We have found our place, start copying out the new attributes.
 437          */
 438         for (; i < ichdr.count; entry++, i++) {
 439                 char *name;
 440                 int namelen, valuelen;
 441
 442                 if (be32_to_cpu(entry->hashval) != cursor->hashval) {
 443                         cursor->hashval = be32_to_cpu(entry->hashval);
 444                         cursor->offset = 0;
 445                 }
 446
 447                 if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
 448                     !context->allow_incomplete)
 449                         continue;
 450
 451                 if (entry->flags & XFS_ATTR_LOCAL) {
 452                         xfs_attr_leaf_name_local_t *name_loc;
 453
 454                         name_loc = xfs_attr3_leaf_name_local(leaf, i);
 455                         name = name_loc->nameval;
 456                         namelen = name_loc->namelen;
 457                         valuelen = be16_to_cpu(name_loc->valuelen);
 458                 } else {
 459                         xfs_attr_leaf_name_remote_t *name_rmt;
 460
 461                         name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
 462                         name = name_rmt->name;
 463                         namelen = name_rmt->namelen;
 464                         valuelen = be32_to_cpu(name_rmt->valuelen);
 465                 }
 466
 467                 if (XFS_IS_CORRUPT(context->dp->i_mount,
 468                                    !xfs_attr_namecheck(name, namelen)))
 469                         return -EFSCORRUPTED;
 470                 context->put_listent(context, entry->flags,
 471                                               name, namelen, valuelen);
 472                 if (context->seen_enough)
 473                         break;
 474                 cursor->offset++;
 475         }
 476         trace_xfs_attr_list_leaf_end(context);
 477         return 0;
 478 }
 479
 480 /*
 481  * Copy out attribute entries for attr_list(), for leaf attribute lists.
 482  */
 483 STATIC int
 484 xfs_attr_leaf_list(
 485         struct xfs_attr_list_context    *context)
 486 {
 487         struct xfs_buf                  *bp;
 488         int                             error;
 489
 490         trace_xfs_attr_leaf_list(context);
 491
 492         context->cursor.blkno = 0;
 493         error = xfs_attr3_leaf_read(context->tp, context->dp, 0, &bp);
 494         if (error)
 495                 return error;
 496
 497         error = xfs_attr3_leaf_list_int(bp, context);
 498         xfs_trans_brelse(context->tp, bp);
 499         return error;
 500 }
 501
 502 int
 503 xfs_attr_list_ilocked(
 504         struct xfs_attr_list_context    *context)
 505 {
 506         struct xfs_inode                *dp = context->dp;
 507
 508         ASSERT(xfs_isilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 509
 510         /*
 511          * Decide on what work routines to call based on the inode size.
 512          */
 513         if (!xfs_inode_hasattr(dp))
 514                 return 0;
 515         if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL)
 516                 return xfs_attr_shortform_list(context);
 517         if (xfs_attr_is_leaf(dp))
 518                 return xfs_attr_leaf_list(context);
 519         return xfs_attr_node_list(context);
 520 }
 521
 522 int
 523 xfs_attr_list(
 524         struct xfs_attr_list_context    *context)
 525 {
 526         struct xfs_inode                *dp = context->dp;
 527         uint                            lock_mode;
 528         int                             error;
 529
 530         XFS_STATS_INC(dp->i_mount, xs_attr_list);
 531
 532         if (XFS_FORCED_SHUTDOWN(dp->i_mount))
 533                 return -EIO;
 534
 535         lock_mode = xfs_ilock_attr_map_shared(dp);
 536         error = xfs_attr_list_ilocked(context);
 537         xfs_iunlock(dp, lock_mode);
 538         return error;
 539 }