1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_mount.h"
13#include "xfs_defer.h"
14#include "xfs_da_format.h"
15#include "xfs_da_btree.h"
16#include "xfs_attr_sf.h"
17#include "xfs_inode.h"
18#include "xfs_trans.h"
19#include "xfs_bmap.h"
20#include "xfs_bmap_btree.h"
21#include "xfs_attr.h"
22#include "xfs_attr_leaf.h"
23#include "xfs_attr_remote.h"
24#include "xfs_quota.h"
25#include "xfs_trans_space.h"
26#include "xfs_trace.h"
27#include "xfs_attr_item.h"
28#include "xfs_xattr.h"
29
30struct kmem_cache *xfs_attr_intent_cache;
31
32/*
33 * xfs_attr.c
34 *
35 * Provide the external interfaces to manage attribute lists.
36 */
37
38/*========================================================================
39 * Function prototypes for the kernel.
40 *========================================================================*/
41
42/*
43 * Internal routines when attribute list fits inside the inode.
44 */
45STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);
46
47/*
48 * Internal routines when attribute list is one block.
49 */
50STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
51STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
52STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
53STATIC int xfs_attr_leaf_try_add(struct xfs_da_args *args);
54
55/*
56 * Internal routines when attribute list is more than one block.
57 */
58STATIC int xfs_attr_node_get(xfs_da_args_t *args);
59STATIC void xfs_attr_restore_rmt_blk(struct xfs_da_args *args);
60static int xfs_attr_node_try_addname(struct xfs_attr_intent *attr);
61STATIC int xfs_attr_node_addname_find_attr(struct xfs_attr_intent *attr);
62STATIC int xfs_attr_node_remove_attr(struct xfs_attr_intent *attr);
63STATIC int xfs_attr_node_lookup(struct xfs_da_args *args,
64 struct xfs_da_state *state);
65
66int
67xfs_inode_hasattr(
68 struct xfs_inode *ip)
69{
70 if (!xfs_inode_has_attr_fork(ip))
71 return 0;
72 if (ip->i_af.if_format == XFS_DINODE_FMT_EXTENTS &&
73 ip->i_af.if_nextents == 0)
74 return 0;
75 return 1;
76}
77
78/*
79 * Returns true if the there is exactly only block in the attr fork, in which
80 * case the attribute fork consists of a single leaf block entry.
81 */
82bool
83xfs_attr_is_leaf(
84 struct xfs_inode *ip)
85{
86 struct xfs_ifork *ifp = &ip->i_af;
87 struct xfs_iext_cursor icur;
88 struct xfs_bmbt_irec imap;
89
90 if (ifp->if_nextents != 1 || ifp->if_format != XFS_DINODE_FMT_EXTENTS)
91 return false;
92
93 xfs_iext_first(ifp, &icur);
94 xfs_iext_get_extent(ifp, &icur, &imap);
95 return imap.br_startoff == 0 && imap.br_blockcount == 1;
96}
97
98/*
99 * XXX (dchinner): name path state saving and refilling is an optimisation to
100 * avoid needing to look up name entries after rolling transactions removing
101 * remote xattr blocks between the name entry lookup and name entry removal.
102 * This optimisation got sidelined when combining the set and remove state
103 * machines, but the code has been left in place because it is worthwhile to
104 * restore the optimisation once the combined state machine paths have settled.
105 *
106 * This comment is a public service announcement to remind Future Dave that he
107 * still needs to restore this code to working order.
108 */
109#if 0
110/*
111 * Fill in the disk block numbers in the state structure for the buffers
112 * that are attached to the state structure.
113 * This is done so that we can quickly reattach ourselves to those buffers
114 * after some set of transaction commits have released these buffers.
115 */
116static int
117xfs_attr_fillstate(xfs_da_state_t *state)
118{
119 xfs_da_state_path_t *path;
120 xfs_da_state_blk_t *blk;
121 int level;
122
123 trace_xfs_attr_fillstate(state->args);
124
125 /*
126 * Roll down the "path" in the state structure, storing the on-disk
127 * block number for those buffers in the "path".
128 */
129 path = &state->path;
130 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
131 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
132 if (blk->bp) {
133 blk->disk_blkno = xfs_buf_daddr(blk->bp);
134 blk->bp = NULL;
135 } else {
136 blk->disk_blkno = 0;
137 }
138 }
139
140 /*
141 * Roll down the "altpath" in the state structure, storing the on-disk
142 * block number for those buffers in the "altpath".
143 */
144 path = &state->altpath;
145 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
146 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
147 if (blk->bp) {
148 blk->disk_blkno = xfs_buf_daddr(blk->bp);
149 blk->bp = NULL;
150 } else {
151 blk->disk_blkno = 0;
152 }
153 }
154
155 return 0;
156}
157
158/*
159 * Reattach the buffers to the state structure based on the disk block
160 * numbers stored in the state structure.
161 * This is done after some set of transaction commits have released those
162 * buffers from our grip.
163 */
164static int
165xfs_attr_refillstate(xfs_da_state_t *state)
166{
167 xfs_da_state_path_t *path;
168 xfs_da_state_blk_t *blk;
169 int level, error;
170
171 trace_xfs_attr_refillstate(state->args);
172
173 /*
174 * Roll down the "path" in the state structure, storing the on-disk
175 * block number for those buffers in the "path".
176 */
177 path = &state->path;
178 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
179 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
180 if (blk->disk_blkno) {
181 error = xfs_da3_node_read_mapped(state->args->trans,
182 state->args->dp, blk->disk_blkno,
183 &blk->bp, XFS_ATTR_FORK);
184 if (error)
185 return error;
186 } else {
187 blk->bp = NULL;
188 }
189 }
190
191 /*
192 * Roll down the "altpath" in the state structure, storing the on-disk
193 * block number for those buffers in the "altpath".
194 */
195 path = &state->altpath;
196 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
197 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
198 if (blk->disk_blkno) {
199 error = xfs_da3_node_read_mapped(state->args->trans,
200 state->args->dp, blk->disk_blkno,
201 &blk->bp, XFS_ATTR_FORK);
202 if (error)
203 return error;
204 } else {
205 blk->bp = NULL;
206 }
207 }
208
209 return 0;
210}
211#else
212static int xfs_attr_fillstate(xfs_da_state_t *state) { return 0; }
213#endif
214
215/*========================================================================
216 * Overall external interface routines.
217 *========================================================================*/
218
219/*
220 * Retrieve an extended attribute and its value. Must have ilock.
221 * Returns 0 on successful retrieval, otherwise an error.
222 */
223int
224xfs_attr_get_ilocked(
225 struct xfs_da_args *args)
226{
227 xfs_assert_ilocked(args->dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL);
228
229 if (!xfs_inode_hasattr(args->dp))
230 return -ENOATTR;
231
232 if (args->dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
233 return xfs_attr_shortform_getvalue(args);
234 if (xfs_attr_is_leaf(args->dp))
235 return xfs_attr_leaf_get(args);
236 return xfs_attr_node_get(args);
237}
238
239/*
240 * Retrieve an extended attribute by name, and its value if requested.
241 *
242 * If args->valuelen is zero, then the caller does not want the value, just an
243 * indication whether the attribute exists and the size of the value if it
244 * exists. The size is returned in args.valuelen.
245 *
246 * If args->value is NULL but args->valuelen is non-zero, allocate the buffer
247 * for the value after existence of the attribute has been determined. The
248 * caller always has to free args->value if it is set, no matter if this
249 * function was successful or not.
250 *
251 * If the attribute is found, but exceeds the size limit set by the caller in
252 * args->valuelen, return -ERANGE with the size of the attribute that was found
253 * in args->valuelen.
254 */
255int
256xfs_attr_get(
257 struct xfs_da_args *args)
258{
259 uint lock_mode;
260 int error;
261
262 XFS_STATS_INC(args->dp->i_mount, xs_attr_get);
263
264 if (xfs_is_shutdown(args->dp->i_mount))
265 return -EIO;
266
267 args->geo = args->dp->i_mount->m_attr_geo;
268 args->whichfork = XFS_ATTR_FORK;
269 args->hashval = xfs_da_hashname(args->name, args->namelen);
270
271 /* Entirely possible to look up a name which doesn't exist */
272 args->op_flags = XFS_DA_OP_OKNOENT;
273
274 lock_mode = xfs_ilock_attr_map_shared(args->dp);
275 error = xfs_attr_get_ilocked(args);
276 xfs_iunlock(args->dp, lock_mode);
277
278 return error;
279}
280
281/*
282 * Calculate how many blocks we need for the new attribute,
283 */
284int
285xfs_attr_calc_size(
286 struct xfs_da_args *args,
287 int *local)
288{
289 struct xfs_mount *mp = args->dp->i_mount;
290 int size;
291 int nblks;
292
293 /*
294 * Determine space new attribute will use, and if it would be
295 * "local" or "remote" (note: local != inline).
296 */
297 size = xfs_attr_leaf_newentsize(args, local);
298 nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
299 if (*local) {
300 if (size > (args->geo->blksize / 2)) {
301 /* Double split possible */
302 nblks *= 2;
303 }
304 } else {
305 /*
306 * Out of line attribute, cannot double split, but
307 * make room for the attribute value itself.
308 */
309 uint dblocks = xfs_attr3_rmt_blocks(mp, args->valuelen);
310 nblks += dblocks;
311 nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
312 }
313
314 return nblks;
315}
316
317/* Initialize transaction reservation for attr operations */
318void
319xfs_init_attr_trans(
320 struct xfs_da_args *args,
321 struct xfs_trans_res *tres,
322 unsigned int *total)
323{
324 struct xfs_mount *mp = args->dp->i_mount;
325
326 if (args->value) {
327 tres->tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
328 M_RES(mp)->tr_attrsetrt.tr_logres *
329 args->total;
330 tres->tr_logcount = XFS_ATTRSET_LOG_COUNT;
331 tres->tr_logflags = XFS_TRANS_PERM_LOG_RES;
332 *total = args->total;
333 } else {
334 *tres = M_RES(mp)->tr_attrrm;
335 *total = XFS_ATTRRM_SPACE_RES(mp);
336 }
337}
338
339/*
340 * Add an attr to a shortform fork. If there is no space,
341 * xfs_attr_shortform_addname() will convert to leaf format and return -ENOSPC.
342 * to use.
343 */
344STATIC int
345xfs_attr_try_sf_addname(
346 struct xfs_inode *dp,
347 struct xfs_da_args *args)
348{
349
350 int error;
351
352 /*
353 * Build initial attribute list (if required).
354 */
355 if (dp->i_af.if_format == XFS_DINODE_FMT_EXTENTS)
356 xfs_attr_shortform_create(args);
357
358 error = xfs_attr_shortform_addname(args);
359 if (error == -ENOSPC)
360 return error;
361
362 /*
363 * Commit the shortform mods, and we're done.
364 * NOTE: this is also the error path (EEXIST, etc).
365 */
366 if (!error && !(args->op_flags & XFS_DA_OP_NOTIME))
367 xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
368
369 if (xfs_has_wsync(dp->i_mount))
370 xfs_trans_set_sync(args->trans);
371
372 return error;
373}
374
375static int
376xfs_attr_sf_addname(
377 struct xfs_attr_intent *attr)
378{
379 struct xfs_da_args *args = attr->xattri_da_args;
380 struct xfs_inode *dp = args->dp;
381 int error = 0;
382
383 error = xfs_attr_try_sf_addname(dp, args);
384 if (error != -ENOSPC) {
385 ASSERT(!error || error == -EEXIST);
386 attr->xattri_dela_state = XFS_DAS_DONE;
387 goto out;
388 }
389
390 /*
391 * It won't fit in the shortform, transform to a leaf block. GROT:
392 * another possible req'mt for a double-split btree op.
393 */
394 error = xfs_attr_shortform_to_leaf(args);
395 if (error)
396 return error;
397
398 attr->xattri_dela_state = XFS_DAS_LEAF_ADD;
399out:
400 trace_xfs_attr_sf_addname_return(attr->xattri_dela_state, args->dp);
401 return error;
402}
403
404/*
405 * Handle the state change on completion of a multi-state attr operation.
406 *
407 * If the XFS_DA_OP_REPLACE flag is set, this means the operation was the first
408 * modification in a attr replace operation and we still have to do the second
409 * state, indicated by @replace_state.
410 *
411 * We consume the XFS_DA_OP_REPLACE flag so that when we are called again on
412 * completion of the second half of the attr replace operation we correctly
413 * signal that it is done.
414 */
415static enum xfs_delattr_state
416xfs_attr_complete_op(
417 struct xfs_attr_intent *attr,
418 enum xfs_delattr_state replace_state)
419{
420 struct xfs_da_args *args = attr->xattri_da_args;
421 bool do_replace = args->op_flags & XFS_DA_OP_REPLACE;
422
423 args->op_flags &= ~XFS_DA_OP_REPLACE;
424 args->attr_filter &= ~XFS_ATTR_INCOMPLETE;
425 if (do_replace)
426 return replace_state;
427
428 return XFS_DAS_DONE;
429}
430
431static int
432xfs_attr_leaf_addname(
433 struct xfs_attr_intent *attr)
434{
435 struct xfs_da_args *args = attr->xattri_da_args;
436 int error;
437
438 ASSERT(xfs_attr_is_leaf(args->dp));
439
440 /*
441 * Use the leaf buffer we may already hold locked as a result of
442 * a sf-to-leaf conversion.
443 */
444 error = xfs_attr_leaf_try_add(args);
445
446 if (error == -ENOSPC) {
447 error = xfs_attr3_leaf_to_node(args);
448 if (error)
449 return error;
450
451 /*
452 * We're not in leaf format anymore, so roll the transaction and
453 * retry the add to the newly allocated node block.
454 */
455 attr->xattri_dela_state = XFS_DAS_NODE_ADD;
456 goto out;
457 }
458 if (error)
459 return error;
460
461 /*
462 * We need to commit and roll if we need to allocate remote xattr blocks
463 * or perform more xattr manipulations. Otherwise there is nothing more
464 * to do and we can return success.
465 */
466 if (args->rmtblkno)
467 attr->xattri_dela_state = XFS_DAS_LEAF_SET_RMT;
468 else
469 attr->xattri_dela_state = xfs_attr_complete_op(attr,
470 replace_state: XFS_DAS_LEAF_REPLACE);
471out:
472 trace_xfs_attr_leaf_addname_return(attr->xattri_dela_state, args->dp);
473 return error;
474}
475
476/*
477 * Add an entry to a node format attr tree.
478 *
479 * Note that we might still have a leaf here - xfs_attr_is_leaf() cannot tell
480 * the difference between leaf + remote attr blocks and a node format tree,
481 * so we may still end up having to convert from leaf to node format here.
482 */
483static int
484xfs_attr_node_addname(
485 struct xfs_attr_intent *attr)
486{
487 struct xfs_da_args *args = attr->xattri_da_args;
488 int error;
489
490 error = xfs_attr_node_addname_find_attr(attr);
491 if (error)
492 return error;
493
494 error = xfs_attr_node_try_addname(attr);
495 if (error == -ENOSPC) {
496 error = xfs_attr3_leaf_to_node(args);
497 if (error)
498 return error;
499 /*
500 * No state change, we really are in node form now
501 * but we need the transaction rolled to continue.
502 */
503 goto out;
504 }
505 if (error)
506 return error;
507
508 if (args->rmtblkno)
509 attr->xattri_dela_state = XFS_DAS_NODE_SET_RMT;
510 else
511 attr->xattri_dela_state = xfs_attr_complete_op(attr,
512 replace_state: XFS_DAS_NODE_REPLACE);
513out:
514 trace_xfs_attr_node_addname_return(attr->xattri_dela_state, args->dp);
515 return error;
516}
517
518static int
519xfs_attr_rmtval_alloc(
520 struct xfs_attr_intent *attr)
521{
522 struct xfs_da_args *args = attr->xattri_da_args;
523 int error = 0;
524
525 /*
526 * If there was an out-of-line value, allocate the blocks we
527 * identified for its storage and copy the value. This is done
528 * after we create the attribute so that we don't overflow the
529 * maximum size of a transaction and/or hit a deadlock.
530 */
531 if (attr->xattri_blkcnt > 0) {
532 error = xfs_attr_rmtval_set_blk(attr);
533 if (error)
534 return error;
535 /* Roll the transaction only if there is more to allocate. */
536 if (attr->xattri_blkcnt > 0)
537 goto out;
538 }
539
540 error = xfs_attr_rmtval_set_value(args);
541 if (error)
542 return error;
543
544 attr->xattri_dela_state = xfs_attr_complete_op(attr,
545 replace_state: ++attr->xattri_dela_state);
546 /*
547 * If we are not doing a rename, we've finished the operation but still
548 * have to clear the incomplete flag protecting the new attr from
549 * exposing partially initialised state if we crash during creation.
550 */
551 if (attr->xattri_dela_state == XFS_DAS_DONE)
552 error = xfs_attr3_leaf_clearflag(args);
553out:
554 trace_xfs_attr_rmtval_alloc(attr->xattri_dela_state, args->dp);
555 return error;
556}
557
558/*
559 * Mark an attribute entry INCOMPLETE and save pointers to the relevant buffers
560 * for later deletion of the entry.
561 */
562static int
563xfs_attr_leaf_mark_incomplete(
564 struct xfs_da_args *args,
565 struct xfs_da_state *state)
566{
567 int error;
568
569 /*
570 * Fill in disk block numbers in the state structure
571 * so that we can get the buffers back after we commit
572 * several transactions in the following calls.
573 */
574 error = xfs_attr_fillstate(state);
575 if (error)
576 return error;
577
578 /*
579 * Mark the attribute as INCOMPLETE
580 */
581 return xfs_attr3_leaf_setflag(args);
582}
583
584/* Ensure the da state of an xattr deferred work item is ready to go. */
585static inline void
586xfs_attr_item_init_da_state(
587 struct xfs_attr_intent *attr)
588{
589 struct xfs_da_args *args = attr->xattri_da_args;
590
591 if (!attr->xattri_da_state)
592 attr->xattri_da_state = xfs_da_state_alloc(args);
593 else
594 xfs_da_state_reset(state: attr->xattri_da_state, args);
595}
596
597/*
598 * Initial setup for xfs_attr_node_removename. Make sure the attr is there and
599 * the blocks are valid. Attr keys with remote blocks will be marked
600 * incomplete.
601 */
602static
603int xfs_attr_node_removename_setup(
604 struct xfs_attr_intent *attr)
605{
606 struct xfs_da_args *args = attr->xattri_da_args;
607 struct xfs_da_state *state;
608 int error;
609
610 xfs_attr_item_init_da_state(attr);
611 error = xfs_attr_node_lookup(args, attr->xattri_da_state);
612 if (error != -EEXIST)
613 goto out;
614 error = 0;
615
616 state = attr->xattri_da_state;
617 ASSERT(state->path.blk[state->path.active - 1].bp != NULL);
618 ASSERT(state->path.blk[state->path.active - 1].magic ==
619 XFS_ATTR_LEAF_MAGIC);
620
621 error = xfs_attr_leaf_mark_incomplete(args, state);
622 if (error)
623 goto out;
624 if (args->rmtblkno > 0)
625 error = xfs_attr_rmtval_invalidate(args);
626out:
627 if (error) {
628 xfs_da_state_free(state: attr->xattri_da_state);
629 attr->xattri_da_state = NULL;
630 }
631
632 return error;
633}
634
635/*
636 * Remove the original attr we have just replaced. This is dependent on the
637 * original lookup and insert placing the old attr in args->blkno/args->index
638 * and the new attr in args->blkno2/args->index2.
639 */
640static int
641xfs_attr_leaf_remove_attr(
642 struct xfs_attr_intent *attr)
643{
644 struct xfs_da_args *args = attr->xattri_da_args;
645 struct xfs_inode *dp = args->dp;
646 struct xfs_buf *bp = NULL;
647 int forkoff;
648 int error;
649
650 error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno,
651 &bp);
652 if (error)
653 return error;
654
655 xfs_attr3_leaf_remove(leaf_buffer: bp, args);
656
657 forkoff = xfs_attr_shortform_allfit(bp, dp);
658 if (forkoff)
659 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
660 /* bp is gone due to xfs_da_shrink_inode */
661
662 return error;
663}
664
665/*
666 * Shrink an attribute from leaf to shortform. Used by the node format remove
667 * path when the node format collapses to a single block and so we have to check
668 * if it can be collapsed further.
669 */
670static int
671xfs_attr_leaf_shrink(
672 struct xfs_da_args *args)
673{
674 struct xfs_inode *dp = args->dp;
675 struct xfs_buf *bp;
676 int forkoff;
677 int error;
678
679 if (!xfs_attr_is_leaf(dp))
680 return 0;
681
682 error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp);
683 if (error)
684 return error;
685
686 forkoff = xfs_attr_shortform_allfit(bp, dp);
687 if (forkoff) {
688 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
689 /* bp is gone due to xfs_da_shrink_inode */
690 } else {
691 xfs_trans_brelse(args->trans, bp);
692 }
693
694 return error;
695}
696
697/*
698 * Run the attribute operation specified in @attr.
699 *
700 * This routine is meant to function as a delayed operation and will set the
701 * state to XFS_DAS_DONE when the operation is complete. Calling functions will
702 * need to handle this, and recall the function until either an error or
703 * XFS_DAS_DONE is detected.
704 */
705int
706xfs_attr_set_iter(
707 struct xfs_attr_intent *attr)
708{
709 struct xfs_da_args *args = attr->xattri_da_args;
710 int error = 0;
711
712 /* State machine switch */
713next_state:
714 switch (attr->xattri_dela_state) {
715 case XFS_DAS_UNINIT:
716 ASSERT(0);
717 return -EFSCORRUPTED;
718 case XFS_DAS_SF_ADD:
719 return xfs_attr_sf_addname(attr);
720 case XFS_DAS_LEAF_ADD:
721 return xfs_attr_leaf_addname(attr);
722 case XFS_DAS_NODE_ADD:
723 return xfs_attr_node_addname(attr);
724
725 case XFS_DAS_SF_REMOVE:
726 error = xfs_attr_sf_removename(args);
727 attr->xattri_dela_state = xfs_attr_complete_op(attr,
728 replace_state: xfs_attr_init_add_state(args));
729 break;
730 case XFS_DAS_LEAF_REMOVE:
731 error = xfs_attr_leaf_removename(args);
732 attr->xattri_dela_state = xfs_attr_complete_op(attr,
733 replace_state: xfs_attr_init_add_state(args));
734 break;
735 case XFS_DAS_NODE_REMOVE:
736 error = xfs_attr_node_removename_setup(attr);
737 if (error == -ENOATTR &&
738 (args->op_flags & XFS_DA_OP_RECOVERY)) {
739 attr->xattri_dela_state = xfs_attr_complete_op(attr,
740 replace_state: xfs_attr_init_add_state(args));
741 error = 0;
742 break;
743 }
744 if (error)
745 return error;
746 attr->xattri_dela_state = XFS_DAS_NODE_REMOVE_RMT;
747 if (args->rmtblkno == 0)
748 attr->xattri_dela_state++;
749 break;
750
751 case XFS_DAS_LEAF_SET_RMT:
752 case XFS_DAS_NODE_SET_RMT:
753 error = xfs_attr_rmtval_find_space(attr);
754 if (error)
755 return error;
756 attr->xattri_dela_state++;
757 fallthrough;
758
759 case XFS_DAS_LEAF_ALLOC_RMT:
760 case XFS_DAS_NODE_ALLOC_RMT:
761 error = xfs_attr_rmtval_alloc(attr);
762 if (error)
763 return error;
764 if (attr->xattri_dela_state == XFS_DAS_DONE)
765 break;
766 goto next_state;
767
768 case XFS_DAS_LEAF_REPLACE:
769 case XFS_DAS_NODE_REPLACE:
770 /*
771 * We must "flip" the incomplete flags on the "new" and "old"
772 * attribute/value pairs so that one disappears and one appears
773 * atomically.
774 */
775 error = xfs_attr3_leaf_flipflags(args);
776 if (error)
777 return error;
778 /*
779 * We must commit the flag value change now to make it atomic
780 * and then we can start the next trans in series at REMOVE_OLD.
781 */
782 attr->xattri_dela_state++;
783 break;
784
785 case XFS_DAS_LEAF_REMOVE_OLD:
786 case XFS_DAS_NODE_REMOVE_OLD:
787 /*
788 * If we have a remote attr, start the process of removing it
789 * by invalidating any cached buffers.
790 *
791 * If we don't have a remote attr, we skip the remote block
792 * removal state altogether with a second state increment.
793 */
794 xfs_attr_restore_rmt_blk(args);
795 if (args->rmtblkno) {
796 error = xfs_attr_rmtval_invalidate(args);
797 if (error)
798 return error;
799 } else {
800 attr->xattri_dela_state++;
801 }
802
803 attr->xattri_dela_state++;
804 goto next_state;
805
806 case XFS_DAS_LEAF_REMOVE_RMT:
807 case XFS_DAS_NODE_REMOVE_RMT:
808 error = xfs_attr_rmtval_remove(attr);
809 if (error == -EAGAIN) {
810 error = 0;
811 break;
812 }
813 if (error)
814 return error;
815
816 /*
817 * We've finished removing the remote attr blocks, so commit the
818 * transaction and move on to removing the attr name from the
819 * leaf/node block. Removing the attr might require a full
820 * transaction reservation for btree block freeing, so we
821 * can't do that in the same transaction where we removed the
822 * remote attr blocks.
823 */
824 attr->xattri_dela_state++;
825 break;
826
827 case XFS_DAS_LEAF_REMOVE_ATTR:
828 error = xfs_attr_leaf_remove_attr(attr);
829 attr->xattri_dela_state = xfs_attr_complete_op(attr,
830 replace_state: xfs_attr_init_add_state(args));
831 break;
832
833 case XFS_DAS_NODE_REMOVE_ATTR:
834 error = xfs_attr_node_remove_attr(attr);
835 if (!error)
836 error = xfs_attr_leaf_shrink(args);
837 attr->xattri_dela_state = xfs_attr_complete_op(attr,
838 replace_state: xfs_attr_init_add_state(args));
839 break;
840 default:
841 ASSERT(0);
842 break;
843 }
844
845 trace_xfs_attr_set_iter_return(attr->xattri_dela_state, args->dp);
846 return error;
847}
848
849
850/*
851 * Return EEXIST if attr is found, or ENOATTR if not
852 */
853static int
854xfs_attr_lookup(
855 struct xfs_da_args *args)
856{
857 struct xfs_inode *dp = args->dp;
858 struct xfs_buf *bp = NULL;
859 struct xfs_da_state *state;
860 int error;
861
862 if (!xfs_inode_hasattr(dp))
863 return -ENOATTR;
864
865 if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL) {
866 if (xfs_attr_sf_findname(args))
867 return -EEXIST;
868 return -ENOATTR;
869 }
870
871 if (xfs_attr_is_leaf(dp)) {
872 error = xfs_attr_leaf_hasname(args, &bp);
873
874 if (bp)
875 xfs_trans_brelse(args->trans, bp);
876
877 return error;
878 }
879
880 state = xfs_da_state_alloc(args);
881 error = xfs_attr_node_lookup(args, state);
882 xfs_da_state_free(state);
883 return error;
884}
885
886static void
887xfs_attr_defer_add(
888 struct xfs_da_args *args,
889 unsigned int op_flags)
890{
891
892 struct xfs_attr_intent *new;
893
894 new = kmem_cache_zalloc(xfs_attr_intent_cache,
895 GFP_KERNEL | __GFP_NOFAIL);
896 new->xattri_op_flags = op_flags;
897 new->xattri_da_args = args;
898
899 switch (op_flags) {
900 case XFS_ATTRI_OP_FLAGS_SET:
901 new->xattri_dela_state = xfs_attr_init_add_state(args);
902 break;
903 case XFS_ATTRI_OP_FLAGS_REPLACE:
904 new->xattri_dela_state = xfs_attr_init_replace_state(args);
905 break;
906 case XFS_ATTRI_OP_FLAGS_REMOVE:
907 new->xattri_dela_state = xfs_attr_init_remove_state(args);
908 break;
909 default:
910 ASSERT(0);
911 }
912
913 xfs_defer_add(tp: args->trans, h: &new->xattri_list, ops: &xfs_attr_defer_type);
914 trace_xfs_attr_defer_add(new->xattri_dela_state, args->dp);
915}
916
917/*
918 * Note: If args->value is NULL the attribute will be removed, just like the
919 * Linux ->setattr API.
920 */
921int
922xfs_attr_set(
923 struct xfs_da_args *args)
924{
925 struct xfs_inode *dp = args->dp;
926 struct xfs_mount *mp = dp->i_mount;
927 struct xfs_trans_res tres;
928 bool rsvd = (args->attr_filter & XFS_ATTR_ROOT);
929 int error, local;
930 int rmt_blks = 0;
931 unsigned int total;
932
933 if (xfs_is_shutdown(dp->i_mount))
934 return -EIO;
935
936 error = xfs_qm_dqattach(dp);
937 if (error)
938 return error;
939
940 args->geo = mp->m_attr_geo;
941 args->whichfork = XFS_ATTR_FORK;
942 args->hashval = xfs_da_hashname(args->name, args->namelen);
943
944 /*
945 * We have no control over the attribute names that userspace passes us
946 * to remove, so we have to allow the name lookup prior to attribute
947 * removal to fail as well. Preserve the logged flag, since we need
948 * to pass that through to the logging code.
949 */
950 args->op_flags = XFS_DA_OP_OKNOENT |
951 (args->op_flags & XFS_DA_OP_LOGGED);
952
953 if (args->value) {
954 XFS_STATS_INC(mp, xs_attr_set);
955 args->total = xfs_attr_calc_size(args, local: &local);
956
957 /*
958 * If the inode doesn't have an attribute fork, add one.
959 * (inode must not be locked when we call this routine)
960 */
961 if (xfs_inode_has_attr_fork(dp) == 0) {
962 int sf_size = sizeof(struct xfs_attr_sf_hdr) +
963 xfs_attr_sf_entsize_byname(args->namelen,
964 args->valuelen);
965
966 error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
967 if (error)
968 return error;
969 }
970
971 if (!local)
972 rmt_blks = xfs_attr3_rmt_blocks(mp, attrlen: args->valuelen);
973 } else {
974 XFS_STATS_INC(mp, xs_attr_remove);
975 rmt_blks = xfs_attr3_rmt_blocks(mp, XFS_XATTR_SIZE_MAX);
976 }
977
978 /*
979 * Root fork attributes can use reserved data blocks for this
980 * operation if necessary
981 */
982 xfs_init_attr_trans(args, tres: &tres, total: &total);
983 error = xfs_trans_alloc_inode(dp, &tres, total, 0, rsvd, &args->trans);
984 if (error)
985 return error;
986
987 if (args->value || xfs_inode_hasattr(ip: dp)) {
988 error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,
989 XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
990 if (error == -EFBIG)
991 error = xfs_iext_count_upgrade(args->trans, dp,
992 XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
993 if (error)
994 goto out_trans_cancel;
995 }
996
997 error = xfs_attr_lookup(args);
998 switch (error) {
999 case -EEXIST:
1000 if (!args->value) {
1001 /* if no value, we are performing a remove operation */
1002 xfs_attr_defer_add(args, XFS_ATTRI_OP_FLAGS_REMOVE);
1003 break;
1004 }
1005
1006 /* Pure create fails if the attr already exists */
1007 if (args->attr_flags & XATTR_CREATE)
1008 goto out_trans_cancel;
1009 xfs_attr_defer_add(args, XFS_ATTRI_OP_FLAGS_REPLACE);
1010 break;
1011 case -ENOATTR:
1012 /* Can't remove what isn't there. */
1013 if (!args->value)
1014 goto out_trans_cancel;
1015
1016 /* Pure replace fails if no existing attr to replace. */
1017 if (args->attr_flags & XATTR_REPLACE)
1018 goto out_trans_cancel;
1019 xfs_attr_defer_add(args, XFS_ATTRI_OP_FLAGS_SET);
1020 break;
1021 default:
1022 goto out_trans_cancel;
1023 }
1024
1025 /*
1026 * If this is a synchronous mount, make sure that the
1027 * transaction goes to disk before returning to the user.
1028 */
1029 if (xfs_has_wsync(mp))
1030 xfs_trans_set_sync(args->trans);
1031
1032 if (!(args->op_flags & XFS_DA_OP_NOTIME))
1033 xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
1034
1035 /*
1036 * Commit the last in the sequence of transactions.
1037 */
1038 xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
1039 error = xfs_trans_commit(args->trans);
1040out_unlock:
1041 xfs_iunlock(dp, XFS_ILOCK_EXCL);
1042 return error;
1043
1044out_trans_cancel:
1045 if (args->trans)
1046 xfs_trans_cancel(args->trans);
1047 goto out_unlock;
1048}
1049
1050/*========================================================================
1051 * External routines when attribute list is inside the inode
1052 *========================================================================*/
1053
1054static inline int xfs_attr_sf_totsize(struct xfs_inode *dp)
1055{
1056 struct xfs_attr_sf_hdr *sf = dp->i_af.if_data;
1057
1058 return be16_to_cpu(sf->totsize);
1059}
1060
1061/*
1062 * Add a name to the shortform attribute list structure
1063 * This is the external routine.
1064 */
1065static int
1066xfs_attr_shortform_addname(
1067 struct xfs_da_args *args)
1068{
1069 int newsize, forkoff;
1070
1071 trace_xfs_attr_sf_addname(args);
1072
1073 if (xfs_attr_sf_findname(args)) {
1074 int error;
1075
1076 ASSERT(args->op_flags & XFS_DA_OP_REPLACE);
1077
1078 error = xfs_attr_sf_removename(args);
1079 if (error)
1080 return error;
1081
1082 /*
1083 * Since we have removed the old attr, clear XFS_DA_OP_REPLACE
1084 * so that the new attr doesn't fit in shortform format, the
1085 * leaf format add routine won't trip over the attr not being
1086 * around.
1087 */
1088 args->op_flags &= ~XFS_DA_OP_REPLACE;
1089 } else {
1090 ASSERT(!(args->op_flags & XFS_DA_OP_REPLACE));
1091 }
1092
1093 if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX ||
1094 args->valuelen >= XFS_ATTR_SF_ENTSIZE_MAX)
1095 return -ENOSPC;
1096
1097 newsize = xfs_attr_sf_totsize(dp: args->dp);
1098 newsize += xfs_attr_sf_entsize_byname(args->namelen, args->valuelen);
1099
1100 forkoff = xfs_attr_shortform_bytesfit(dp: args->dp, bytes: newsize);
1101 if (!forkoff)
1102 return -ENOSPC;
1103
1104 xfs_attr_shortform_add(args, forkoff);
1105 return 0;
1106}
1107
1108
1109/*========================================================================
1110 * External routines when attribute list is one block
1111 *========================================================================*/
1112
1113/* Save the current remote block info and clear the current pointers. */
1114static void
1115xfs_attr_save_rmt_blk(
1116 struct xfs_da_args *args)
1117{
1118 args->blkno2 = args->blkno;
1119 args->index2 = args->index;
1120 args->rmtblkno2 = args->rmtblkno;
1121 args->rmtblkcnt2 = args->rmtblkcnt;
1122 args->rmtvaluelen2 = args->rmtvaluelen;
1123 args->rmtblkno = 0;
1124 args->rmtblkcnt = 0;
1125 args->rmtvaluelen = 0;
1126}
1127
1128/* Set stored info about a remote block */
1129static void
1130xfs_attr_restore_rmt_blk(
1131 struct xfs_da_args *args)
1132{
1133 args->blkno = args->blkno2;
1134 args->index = args->index2;
1135 args->rmtblkno = args->rmtblkno2;
1136 args->rmtblkcnt = args->rmtblkcnt2;
1137 args->rmtvaluelen = args->rmtvaluelen2;
1138}
1139
1140/*
1141 * Tries to add an attribute to an inode in leaf form
1142 *
1143 * This function is meant to execute as part of a delayed operation and leaves
1144 * the transaction handling to the caller. On success the attribute is added
1145 * and the inode and transaction are left dirty. If there is not enough space,
1146 * the attr data is converted to node format and -ENOSPC is returned. Caller is
1147 * responsible for handling the dirty inode and transaction or adding the attr
1148 * in node format.
1149 */
1150STATIC int
1151xfs_attr_leaf_try_add(
1152 struct xfs_da_args *args)
1153{
1154 struct xfs_buf *bp;
1155 int error;
1156
1157 error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp);
1158 if (error)
1159 return error;
1160
1161 /*
1162 * Look up the xattr name to set the insertion point for the new xattr.
1163 */
1164 error = xfs_attr3_leaf_lookup_int(leaf: bp, args);
1165 switch (error) {
1166 case -ENOATTR:
1167 if (args->op_flags & XFS_DA_OP_REPLACE)
1168 goto out_brelse;
1169 break;
1170 case -EEXIST:
1171 if (!(args->op_flags & XFS_DA_OP_REPLACE))
1172 goto out_brelse;
1173
1174 trace_xfs_attr_leaf_replace(args);
1175 /*
1176 * Save the existing remote attr state so that the current
1177 * values reflect the state of the new attribute we are about to
1178 * add, not the attribute we just found and will remove later.
1179 */
1180 xfs_attr_save_rmt_blk(args);
1181 break;
1182 case 0:
1183 break;
1184 default:
1185 goto out_brelse;
1186 }
1187
1188 return xfs_attr3_leaf_add(leaf_buffer: bp, args);
1189
1190out_brelse:
1191 xfs_trans_brelse(args->trans, bp);
1192 return error;
1193}
1194
1195/*
1196 * Return EEXIST if attr is found, or ENOATTR if not
1197 */
1198STATIC int
1199xfs_attr_leaf_hasname(
1200 struct xfs_da_args *args,
1201 struct xfs_buf **bp)
1202{
1203 int error = 0;
1204
1205 error = xfs_attr3_leaf_read(args->trans, args->dp, 0, bp);
1206 if (error)
1207 return error;
1208
1209 error = xfs_attr3_leaf_lookup_int(leaf: *bp, args);
1210 if (error != -ENOATTR && error != -EEXIST)
1211 xfs_trans_brelse(args->trans, *bp);
1212
1213 return error;
1214}
1215
1216/*
1217 * Remove a name from the leaf attribute list structure
1218 *
1219 * This leaf block cannot have a "remote" value, we only call this routine
1220 * if bmap_one_block() says there is only one block (ie: no remote blks).
1221 */
1222STATIC int
1223xfs_attr_leaf_removename(
1224 struct xfs_da_args *args)
1225{
1226 struct xfs_inode *dp;
1227 struct xfs_buf *bp;
1228 int error, forkoff;
1229
1230 trace_xfs_attr_leaf_removename(args);
1231
1232 /*
1233 * Remove the attribute.
1234 */
1235 dp = args->dp;
1236
1237 error = xfs_attr_leaf_hasname(args, &bp);
1238 if (error == -ENOATTR) {
1239 xfs_trans_brelse(args->trans, bp);
1240 if (args->op_flags & XFS_DA_OP_RECOVERY)
1241 return 0;
1242 return error;
1243 } else if (error != -EEXIST)
1244 return error;
1245
1246 xfs_attr3_leaf_remove(leaf_buffer: bp, args);
1247
1248 /*
1249 * If the result is small enough, shrink it all into the inode.
1250 */
1251 forkoff = xfs_attr_shortform_allfit(bp, dp);
1252 if (forkoff)
1253 return xfs_attr3_leaf_to_shortform(bp, args, forkoff);
1254 /* bp is gone due to xfs_da_shrink_inode */
1255
1256 return 0;
1257}
1258
1259/*
1260 * Look up a name in a leaf attribute list structure.
1261 *
1262 * This leaf block cannot have a "remote" value, we only call this routine
1263 * if bmap_one_block() says there is only one block (ie: no remote blks).
1264 *
1265 * Returns 0 on successful retrieval, otherwise an error.
1266 */
1267STATIC int
1268xfs_attr_leaf_get(xfs_da_args_t *args)
1269{
1270 struct xfs_buf *bp;
1271 int error;
1272
1273 trace_xfs_attr_leaf_get(args);
1274
1275 error = xfs_attr_leaf_hasname(args, &bp);
1276
1277 if (error == -ENOATTR) {
1278 xfs_trans_brelse(args->trans, bp);
1279 return error;
1280 } else if (error != -EEXIST)
1281 return error;
1282
1283
1284 error = xfs_attr3_leaf_getvalue(bp, args);
1285 xfs_trans_brelse(args->trans, bp);
1286 return error;
1287}
1288
1289/* Return EEXIST if attr is found, or ENOATTR if not. */
1290STATIC int
1291xfs_attr_node_lookup(
1292 struct xfs_da_args *args,
1293 struct xfs_da_state *state)
1294{
1295 int retval, error;
1296
1297 /*
1298 * Search to see if name exists, and get back a pointer to it.
1299 */
1300 error = xfs_da3_node_lookup_int(state, result: &retval);
1301 if (error)
1302 return error;
1303
1304 return retval;
1305}
1306
1307/*========================================================================
1308 * External routines when attribute list size > geo->blksize
1309 *========================================================================*/
1310
1311STATIC int
1312xfs_attr_node_addname_find_attr(
1313 struct xfs_attr_intent *attr)
1314{
1315 struct xfs_da_args *args = attr->xattri_da_args;
1316 int error;
1317
1318 /*
1319 * Search to see if name already exists, and get back a pointer
1320 * to where it should go.
1321 */
1322 xfs_attr_item_init_da_state(attr);
1323 error = xfs_attr_node_lookup(args, attr->xattri_da_state);
1324 switch (error) {
1325 case -ENOATTR:
1326 if (args->op_flags & XFS_DA_OP_REPLACE)
1327 goto error;
1328 break;
1329 case -EEXIST:
1330 if (!(args->op_flags & XFS_DA_OP_REPLACE))
1331 goto error;
1332
1333
1334 trace_xfs_attr_node_replace(args);
1335 /*
1336 * Save the existing remote attr state so that the current
1337 * values reflect the state of the new attribute we are about to
1338 * add, not the attribute we just found and will remove later.
1339 */
1340 xfs_attr_save_rmt_blk(args);
1341 break;
1342 case 0:
1343 break;
1344 default:
1345 goto error;
1346 }
1347
1348 return 0;
1349error:
1350 if (attr->xattri_da_state) {
1351 xfs_da_state_free(state: attr->xattri_da_state);
1352 attr->xattri_da_state = NULL;
1353 }
1354 return error;
1355}
1356
1357/*
1358 * Add a name to a Btree-format attribute list.
1359 *
1360 * This will involve walking down the Btree, and may involve splitting
1361 * leaf nodes and even splitting intermediate nodes up to and including
1362 * the root node (a special case of an intermediate node).
1363 */
1364static int
1365xfs_attr_node_try_addname(
1366 struct xfs_attr_intent *attr)
1367{
1368 struct xfs_da_state *state = attr->xattri_da_state;
1369 struct xfs_da_state_blk *blk;
1370 int error;
1371
1372 trace_xfs_attr_node_addname(state->args);
1373
1374 blk = &state->path.blk[state->path.active-1];
1375 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1376
1377 error = xfs_attr3_leaf_add(leaf_buffer: blk->bp, args: state->args);
1378 if (error == -ENOSPC) {
1379 if (state->path.active == 1) {
1380 /*
1381 * Its really a single leaf node, but it had
1382 * out-of-line values so it looked like it *might*
1383 * have been a b-tree. Let the caller deal with this.
1384 */
1385 goto out;
1386 }
1387
1388 /*
1389 * Split as many Btree elements as required.
1390 * This code tracks the new and old attr's location
1391 * in the index/blkno/rmtblkno/rmtblkcnt fields and
1392 * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
1393 */
1394 error = xfs_da3_split(state);
1395 if (error)
1396 goto out;
1397 } else {
1398 /*
1399 * Addition succeeded, update Btree hashvals.
1400 */
1401 xfs_da3_fixhashpath(state, path_to_to_fix: &state->path);
1402 }
1403
1404out:
1405 xfs_da_state_free(state);
1406 attr->xattri_da_state = NULL;
1407 return error;
1408}
1409
1410static int
1411xfs_attr_node_removename(
1412 struct xfs_da_args *args,
1413 struct xfs_da_state *state)
1414{
1415 struct xfs_da_state_blk *blk;
1416 int retval;
1417
1418 /*
1419 * Remove the name and update the hashvals in the tree.
1420 */
1421 blk = &state->path.blk[state->path.active-1];
1422 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1423 retval = xfs_attr3_leaf_remove(leaf_buffer: blk->bp, args);
1424 xfs_da3_fixhashpath(state, path_to_to_fix: &state->path);
1425
1426 return retval;
1427}
1428
1429static int
1430xfs_attr_node_remove_attr(
1431 struct xfs_attr_intent *attr)
1432{
1433 struct xfs_da_args *args = attr->xattri_da_args;
1434 struct xfs_da_state *state = xfs_da_state_alloc(args);
1435 int retval = 0;
1436 int error = 0;
1437
1438 /*
1439 * The attr we are removing has already been marked incomplete, so
1440 * we need to set the filter appropriately to re-find the "old"
1441 * attribute entry after any split ops.
1442 */
1443 args->attr_filter |= XFS_ATTR_INCOMPLETE;
1444 error = xfs_da3_node_lookup_int(state, result: &retval);
1445 if (error)
1446 goto out;
1447
1448 error = xfs_attr_node_removename(args, state);
1449
1450 /*
1451 * Check to see if the tree needs to be collapsed.
1452 */
1453 if (retval && (state->path.active > 1)) {
1454 error = xfs_da3_join(state);
1455 if (error)
1456 goto out;
1457 }
1458 retval = error = 0;
1459
1460out:
1461 xfs_da_state_free(state);
1462 if (error)
1463 return error;
1464 return retval;
1465}
1466
1467/*
1468 * Retrieve the attribute data from a node attribute list.
1469 *
1470 * This routine gets called for any attribute fork that has more than one
1471 * block, ie: both true Btree attr lists and for single-leaf-blocks with
1472 * "remote" values taking up more blocks.
1473 *
1474 * Returns 0 on successful retrieval, otherwise an error.
1475 */
1476STATIC int
1477xfs_attr_node_get(
1478 struct xfs_da_args *args)
1479{
1480 struct xfs_da_state *state;
1481 struct xfs_da_state_blk *blk;
1482 int i;
1483 int error;
1484
1485 trace_xfs_attr_node_get(args);
1486
1487 /*
1488 * Search to see if name exists, and get back a pointer to it.
1489 */
1490 state = xfs_da_state_alloc(args);
1491 error = xfs_attr_node_lookup(args, state);
1492 if (error != -EEXIST)
1493 goto out_release;
1494
1495 /*
1496 * Get the value, local or "remote"
1497 */
1498 blk = &state->path.blk[state->path.active - 1];
1499 error = xfs_attr3_leaf_getvalue(bp: blk->bp, args);
1500
1501 /*
1502 * If not in a transaction, we have to release all the buffers.
1503 */
1504out_release:
1505 for (i = 0; i < state->path.active; i++) {
1506 xfs_trans_brelse(args->trans, state->path.blk[i].bp);
1507 state->path.blk[i].bp = NULL;
1508 }
1509
1510 xfs_da_state_free(state);
1511 return error;
1512}
1513
1514/* Returns true if the attribute entry name is valid. */
1515bool
1516xfs_attr_namecheck(
1517 const void *name,
1518 size_t length)
1519{
1520 /*
1521 * MAXNAMELEN includes the trailing null, but (name/length) leave it
1522 * out, so use >= for the length check.
1523 */
1524 if (length >= MAXNAMELEN)
1525 return false;
1526
1527 /* There shouldn't be any nulls here */
1528 return !memchr(name, 0, length);
1529}
1530
1531int __init
1532xfs_attr_intent_init_cache(void)
1533{
1534 xfs_attr_intent_cache = kmem_cache_create("xfs_attr_intent",
1535 sizeof(struct xfs_attr_intent),
1536 0, 0, NULL);
1537
1538 return xfs_attr_intent_cache != NULL ? 0 : -ENOMEM;
1539}
1540
1541void
1542xfs_attr_intent_destroy_cache(void)
1543{
1544 kmem_cache_destroy(xfs_attr_intent_cache);
1545 xfs_attr_intent_cache = NULL;
1546}
1547

source code of linux/fs/xfs/libxfs/xfs_attr.c