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
xfs_attr_shortform_compare(const void * a,const void * b)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
xfs_attr_shortform_list(struct xfs_attr_list_context * context)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_shortform *sf;
60 struct xfs_attr_sf_entry *sfe;
61 int sbsize, nsbuf, count, i;
62 int error = 0;
63
64 sf = (struct xfs_attr_shortform *)dp->i_af.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_af.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_af.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
xfs_attr_node_list_lookup(struct xfs_attr_list_context * context,struct xfs_attrlist_cursor_kern * cursor,struct xfs_buf ** pbp)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
xfs_attr_node_list(struct xfs_attr_list_context * context)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
xfs_attr3_leaf_list_int(struct xfs_buf * bp,struct xfs_attr_list_context * context)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
xfs_attr_leaf_list(struct xfs_attr_list_context * context)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
xfs_attr_list_ilocked(struct xfs_attr_list_context * context)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_af.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
xfs_attr_list(struct xfs_attr_list_context * context)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_is_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 }
540
