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