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#include "xfs_parent.h"
30
31struct kmem_cache *xfs_attr_intent_cache;
32
33/*
34 * xfs_attr.c
35 *
36 * Provide the external interfaces to manage attribute lists.
37 */
38
39/*========================================================================
40 * Function prototypes for the kernel.
41 *========================================================================*/
42
43/*
44 * Internal routines when attribute list fits inside the inode.
45 */
46STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);
47
48/*
49 * Internal routines when attribute list is one block.
50 */
51STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
52STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
53STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
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 ASSERT(!xfs_need_iread_extents(ifp));
91
92 if (ifp->if_nextents != 1 || ifp->if_format != XFS_DINODE_FMT_EXTENTS)
93 return false;
94
95 xfs_iext_first(ifp, &icur);
96 xfs_iext_get_extent(ifp, &icur, &imap);
97 return imap.br_startoff == 0 && imap.br_blockcount == 1;
98}
99
100/*
101 * XXX (dchinner): name path state saving and refilling is an optimisation to
102 * avoid needing to look up name entries after rolling transactions removing
103 * remote xattr blocks between the name entry lookup and name entry removal.
104 * This optimisation got sidelined when combining the set and remove state
105 * machines, but the code has been left in place because it is worthwhile to
106 * restore the optimisation once the combined state machine paths have settled.
107 *
108 * This comment is a public service announcement to remind Future Dave that he
109 * still needs to restore this code to working order.
110 */
111#if 0
112/*
113 * Fill in the disk block numbers in the state structure for the buffers
114 * that are attached to the state structure.
115 * This is done so that we can quickly reattach ourselves to those buffers
116 * after some set of transaction commits have released these buffers.
117 */
118static int
119xfs_attr_fillstate(xfs_da_state_t *state)
120{
121 xfs_da_state_path_t *path;
122 xfs_da_state_blk_t *blk;
123 int level;
124
125 trace_xfs_attr_fillstate(state->args);
126
127 /*
128 * Roll down the "path" in the state structure, storing the on-disk
129 * block number for those buffers in the "path".
130 */
131 path = &state->path;
132 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
133 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
134 if (blk->bp) {
135 blk->disk_blkno = xfs_buf_daddr(blk->bp);
136 blk->bp = NULL;
137 } else {
138 blk->disk_blkno = 0;
139 }
140 }
141
142 /*
143 * Roll down the "altpath" in the state structure, storing the on-disk
144 * block number for those buffers in the "altpath".
145 */
146 path = &state->altpath;
147 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
148 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
149 if (blk->bp) {
150 blk->disk_blkno = xfs_buf_daddr(blk->bp);
151 blk->bp = NULL;
152 } else {
153 blk->disk_blkno = 0;
154 }
155 }
156
157 return 0;
158}
159
160/*
161 * Reattach the buffers to the state structure based on the disk block
162 * numbers stored in the state structure.
163 * This is done after some set of transaction commits have released those
164 * buffers from our grip.
165 */
166static int
167xfs_attr_refillstate(xfs_da_state_t *state)
168{
169 xfs_da_state_path_t *path;
170 xfs_da_state_blk_t *blk;
171 int level, error;
172
173 trace_xfs_attr_refillstate(state->args);
174
175 /*
176 * Roll down the "path" in the state structure, storing the on-disk
177 * block number for those buffers in the "path".
178 */
179 path = &state->path;
180 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
181 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
182 if (blk->disk_blkno) {
183 error = xfs_da3_node_read_mapped(state->args->trans,
184 state->args->dp, blk->disk_blkno,
185 &blk->bp, XFS_ATTR_FORK);
186 if (error)
187 return error;
188 } else {
189 blk->bp = NULL;
190 }
191 }
192
193 /*
194 * Roll down the "altpath" in the state structure, storing the on-disk
195 * block number for those buffers in the "altpath".
196 */
197 path = &state->altpath;
198 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
199 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
200 if (blk->disk_blkno) {
201 error = xfs_da3_node_read_mapped(state->args->trans,
202 state->args->dp, blk->disk_blkno,
203 &blk->bp, XFS_ATTR_FORK);
204 if (error)
205 return error;
206 } else {
207 blk->bp = NULL;
208 }
209 }
210
211 return 0;
212}
213#else
214static int xfs_attr_fillstate(xfs_da_state_t *state) { return 0; }
215#endif
216
217/*========================================================================
218 * Overall external interface routines.
219 *========================================================================*/
220
221/*
222 * Retrieve an extended attribute and its value. Must have ilock.
223 * Returns 0 on successful retrieval, otherwise an error.
224 */
225int
226xfs_attr_get_ilocked(
227 struct xfs_da_args *args)
228{
229 int error;
230
231 xfs_assert_ilocked(args->dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL);
232
233 if (!xfs_inode_hasattr(args->dp))
234 return -ENOATTR;
235
236 /*
237 * The incore attr fork iext tree must be loaded for xfs_attr_is_leaf
238 * to work correctly.
239 */
240 error = xfs_iread_extents(args->trans, args->dp, XFS_ATTR_FORK);
241 if (error)
242 return error;
243
244 if (args->dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
245 return xfs_attr_shortform_getvalue(args);
246 if (xfs_attr_is_leaf(args->dp))
247 return xfs_attr_leaf_get(args);
248 return xfs_attr_node_get(args);
249}
250
251/*
252 * Retrieve an extended attribute by name, and its value if requested.
253 *
254 * If args->valuelen is zero, then the caller does not want the value, just an
255 * indication whether the attribute exists and the size of the value if it
256 * exists. The size is returned in args.valuelen.
257 *
258 * If args->value is NULL but args->valuelen is non-zero, allocate the buffer
259 * for the value after existence of the attribute has been determined. The
260 * caller always has to free args->value if it is set, no matter if this
261 * function was successful or not.
262 *
263 * If the attribute is found, but exceeds the size limit set by the caller in
264 * args->valuelen, return -ERANGE with the size of the attribute that was found
265 * in args->valuelen.
266 */
267int
268xfs_attr_get(
269 struct xfs_da_args *args)
270{
271 uint lock_mode;
272 int error;
273
274 XFS_STATS_INC(args->dp->i_mount, xs_attr_get);
275
276 if (xfs_is_shutdown(args->dp->i_mount))
277 return -EIO;
278
279 if (!args->owner)
280 args->owner = args->dp->i_ino;
281 args->geo = args->dp->i_mount->m_attr_geo;
282 args->whichfork = XFS_ATTR_FORK;
283 xfs_attr_sethash(args);
284
285 /* Entirely possible to look up a name which doesn't exist */
286 args->op_flags = XFS_DA_OP_OKNOENT;
287
288 lock_mode = xfs_ilock_attr_map_shared(args->dp);
289 error = xfs_attr_get_ilocked(args);
290 xfs_iunlock(args->dp, lock_mode);
291
292 return error;
293}
294
295/*
296 * Calculate how many blocks we need for the new attribute,
297 */
298int
299xfs_attr_calc_size(
300 struct xfs_da_args *args,
301 int *local)
302{
303 struct xfs_mount *mp = args->dp->i_mount;
304 int size;
305 int nblks;
306
307 /*
308 * Determine space new attribute will use, and if it would be
309 * "local" or "remote" (note: local != inline).
310 */
311 size = xfs_attr_leaf_newentsize(args, local);
312 nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
313 if (*local) {
314 if (size > (args->geo->blksize / 2)) {
315 /* Double split possible */
316 nblks *= 2;
317 }
318 } else {
319 /*
320 * Out of line attribute, cannot double split, but
321 * make room for the attribute value itself.
322 */
323 uint dblocks = xfs_attr3_rmt_blocks(mp, args->valuelen);
324 nblks += dblocks;
325 nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
326 }
327
328 return nblks;
329}
330
331/* Initialize transaction reservation for an xattr set/replace/upsert */
332inline struct xfs_trans_res
333xfs_attr_set_resv(
334 const struct xfs_da_args *args)
335{
336 struct xfs_mount *mp = args->dp->i_mount;
337 struct xfs_trans_res ret = {
338 .tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
339 M_RES(mp)->tr_attrsetrt.tr_logres * args->total,
340 .tr_logcount = XFS_ATTRSET_LOG_COUNT,
341 .tr_logflags = XFS_TRANS_PERM_LOG_RES,
342 };
343
344 return ret;
345}
346
347/*
348 * Add an attr to a shortform fork. If there is no space,
349 * xfs_attr_shortform_addname() will convert to leaf format and return -ENOSPC.
350 * to use.
351 */
352STATIC int
353xfs_attr_try_sf_addname(
354 struct xfs_inode *dp,
355 struct xfs_da_args *args)
356{
357
358 int error;
359
360 /*
361 * Build initial attribute list (if required).
362 */
363 if (dp->i_af.if_format == XFS_DINODE_FMT_EXTENTS)
364 xfs_attr_shortform_create(args);
365
366 error = xfs_attr_shortform_addname(args);
367 if (error == -ENOSPC)
368 return error;
369
370 /*
371 * Commit the shortform mods, and we're done.
372 * NOTE: this is also the error path (EEXIST, etc).
373 */
374 if (!error)
375 xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
376
377 if (xfs_has_wsync(dp->i_mount))
378 xfs_trans_set_sync(args->trans);
379
380 return error;
381}
382
383static int
384xfs_attr_sf_addname(
385 struct xfs_attr_intent *attr)
386{
387 struct xfs_da_args *args = attr->xattri_da_args;
388 struct xfs_inode *dp = args->dp;
389 int error = 0;
390
391 error = xfs_attr_try_sf_addname(dp, args);
392 if (error != -ENOSPC) {
393 ASSERT(!error || error == -EEXIST);
394 attr->xattri_dela_state = XFS_DAS_DONE;
395 goto out;
396 }
397
398 /*
399 * It won't fit in the shortform, transform to a leaf block. GROT:
400 * another possible req'mt for a double-split btree op.
401 */
402 error = xfs_attr_shortform_to_leaf(args);
403 if (error)
404 return error;
405
406 attr->xattri_dela_state = XFS_DAS_LEAF_ADD;
407out:
408 trace_xfs_attr_sf_addname_return(attr->xattri_dela_state, args->dp);
409 return error;
410}
411
412/* Compute the hash value for a user/root/secure extended attribute */
413xfs_dahash_t
414xfs_attr_hashname(
415 const uint8_t *name,
416 int namelen)
417{
418 return xfs_da_hashname(name, namelen);
419}
420
421/* Compute the hash value for any extended attribute from any namespace. */
422xfs_dahash_t
423xfs_attr_hashval(
424 struct xfs_mount *mp,
425 unsigned int attr_flags,
426 const uint8_t *name,
427 int namelen,
428 const void *value,
429 int valuelen)
430{
431 ASSERT(xfs_attr_check_namespace(attr_flags));
432
433 if (attr_flags & XFS_ATTR_PARENT)
434 return xfs_parent_hashattr(mp, name, namelen, value, valuelen);
435
436 return xfs_attr_hashname(name, namelen);
437}
438
439/* Save the current remote block info and clear the current pointers. */
440static void
441xfs_attr_save_rmt_blk(
442 struct xfs_da_args *args)
443{
444 args->blkno2 = args->blkno;
445 args->index2 = args->index;
446 args->rmtblkno2 = args->rmtblkno;
447 args->rmtblkcnt2 = args->rmtblkcnt;
448 args->rmtvaluelen2 = args->rmtvaluelen;
449 args->rmtblkno = 0;
450 args->rmtblkcnt = 0;
451 args->rmtvaluelen = 0;
452}
453
454/* Set stored info about a remote block */
455static void
456xfs_attr_restore_rmt_blk(
457 struct xfs_da_args *args)
458{
459 args->blkno = args->blkno2;
460 args->index = args->index2;
461 args->rmtblkno = args->rmtblkno2;
462 args->rmtblkcnt = args->rmtblkcnt2;
463 args->rmtvaluelen = args->rmtvaluelen2;
464}
465
466/*
467 * PPTR_REPLACE operations require the caller to set the old and new names and
468 * values explicitly. Update the canonical fields to the new name and value
469 * here now that the removal phase has finished.
470 */
471static void
472xfs_attr_update_pptr_replace_args(
473 struct xfs_da_args *args)
474{
475 ASSERT(args->new_namelen > 0);
476 args->name = args->new_name;
477 args->namelen = args->new_namelen;
478 args->value = args->new_value;
479 args->valuelen = args->new_valuelen;
480 xfs_attr_sethash(args);
481}
482
483/*
484 * Handle the state change on completion of a multi-state attr operation.
485 *
486 * If the XFS_DA_OP_REPLACE flag is set, this means the operation was the first
487 * modification in a attr replace operation and we still have to do the second
488 * state, indicated by @replace_state.
489 *
490 * We consume the XFS_DA_OP_REPLACE flag so that when we are called again on
491 * completion of the second half of the attr replace operation we correctly
492 * signal that it is done.
493 */
494static enum xfs_delattr_state
495xfs_attr_complete_op(
496 struct xfs_attr_intent *attr,
497 enum xfs_delattr_state replace_state)
498{
499 struct xfs_da_args *args = attr->xattri_da_args;
500
501 if (!(args->op_flags & XFS_DA_OP_REPLACE))
502 replace_state = XFS_DAS_DONE;
503 else if (xfs_attr_intent_op(attr) == XFS_ATTRI_OP_FLAGS_PPTR_REPLACE)
504 xfs_attr_update_pptr_replace_args(args);
505
506 args->op_flags &= ~XFS_DA_OP_REPLACE;
507 args->attr_filter &= ~XFS_ATTR_INCOMPLETE;
508 return replace_state;
509}
510
511/*
512 * Try to add an attribute to an inode in leaf form.
513 */
514static int
515xfs_attr_leaf_addname(
516 struct xfs_attr_intent *attr)
517{
518 struct xfs_da_args *args = attr->xattri_da_args;
519 struct xfs_buf *bp;
520 int error;
521
522 ASSERT(xfs_attr_is_leaf(args->dp));
523
524 error = xfs_attr3_leaf_read(args->trans, args->dp, args->owner, 0, &bp);
525 if (error)
526 return error;
527
528 /*
529 * Look up the xattr name to set the insertion point for the new xattr.
530 */
531 error = xfs_attr3_leaf_lookup_int(leaf: bp, args);
532 switch (error) {
533 case -ENOATTR:
534 if (args->op_flags & XFS_DA_OP_REPLACE)
535 goto out_brelse;
536 break;
537 case -EEXIST:
538 if (!(args->op_flags & XFS_DA_OP_REPLACE))
539 goto out_brelse;
540
541 trace_xfs_attr_leaf_replace(args);
542 /*
543 * Save the existing remote attr state so that the current
544 * values reflect the state of the new attribute we are about to
545 * add, not the attribute we just found and will remove later.
546 */
547 xfs_attr_save_rmt_blk(args);
548 break;
549 case 0:
550 break;
551 default:
552 goto out_brelse;
553 }
554
555 /*
556 * We need to commit and roll if we need to allocate remote xattr blocks
557 * or perform more xattr manipulations. Otherwise there is nothing more
558 * to do and we can return success.
559 */
560 if (!xfs_attr3_leaf_add(bp, args)) {
561 error = xfs_attr3_leaf_to_node(args);
562 if (error)
563 return error;
564
565 attr->xattri_dela_state = XFS_DAS_NODE_ADD;
566 } else if (args->rmtblkno) {
567 attr->xattri_dela_state = XFS_DAS_LEAF_SET_RMT;
568 } else {
569 attr->xattri_dela_state =
570 xfs_attr_complete_op(attr, replace_state: XFS_DAS_LEAF_REPLACE);
571 }
572
573 trace_xfs_attr_leaf_addname_return(attr->xattri_dela_state, args->dp);
574 return 0;
575
576out_brelse:
577 xfs_trans_brelse(args->trans, bp);
578 return error;
579}
580
581/*
582 * Add an entry to a node format attr tree.
583 *
584 * Note that we might still have a leaf here - xfs_attr_is_leaf() cannot tell
585 * the difference between leaf + remote attr blocks and a node format tree,
586 * so we may still end up having to convert from leaf to node format here.
587 */
588static int
589xfs_attr_node_addname(
590 struct xfs_attr_intent *attr)
591{
592 struct xfs_da_args *args = attr->xattri_da_args;
593 int error;
594
595 error = xfs_attr_node_addname_find_attr(attr);
596 if (error)
597 return error;
598
599 error = xfs_attr_node_try_addname(attr);
600 if (error == 1) {
601 error = xfs_attr3_leaf_to_node(args);
602 if (error)
603 return error;
604 /*
605 * No state change, we really are in node form now
606 * but we need the transaction rolled to continue.
607 */
608 goto out;
609 }
610 if (error)
611 return error;
612
613 if (args->rmtblkno)
614 attr->xattri_dela_state = XFS_DAS_NODE_SET_RMT;
615 else
616 attr->xattri_dela_state = xfs_attr_complete_op(attr,
617 replace_state: XFS_DAS_NODE_REPLACE);
618out:
619 trace_xfs_attr_node_addname_return(attr->xattri_dela_state, args->dp);
620 return error;
621}
622
623static int
624xfs_attr_rmtval_alloc(
625 struct xfs_attr_intent *attr)
626{
627 struct xfs_da_args *args = attr->xattri_da_args;
628 int error = 0;
629
630 /*
631 * If there was an out-of-line value, allocate the blocks we
632 * identified for its storage and copy the value. This is done
633 * after we create the attribute so that we don't overflow the
634 * maximum size of a transaction and/or hit a deadlock.
635 */
636 if (attr->xattri_blkcnt > 0) {
637 error = xfs_attr_rmtval_set_blk(attr);
638 if (error)
639 return error;
640 /* Roll the transaction only if there is more to allocate. */
641 if (attr->xattri_blkcnt > 0)
642 goto out;
643 }
644
645 error = xfs_attr_rmtval_set_value(args);
646 if (error)
647 return error;
648
649 attr->xattri_dela_state = xfs_attr_complete_op(attr,
650 replace_state: ++attr->xattri_dela_state);
651 /*
652 * If we are not doing a rename, we've finished the operation but still
653 * have to clear the incomplete flag protecting the new attr from
654 * exposing partially initialised state if we crash during creation.
655 */
656 if (attr->xattri_dela_state == XFS_DAS_DONE)
657 error = xfs_attr3_leaf_clearflag(args);
658out:
659 trace_xfs_attr_rmtval_alloc(attr->xattri_dela_state, args->dp);
660 return error;
661}
662
663/*
664 * Mark an attribute entry INCOMPLETE and save pointers to the relevant buffers
665 * for later deletion of the entry.
666 */
667static int
668xfs_attr_leaf_mark_incomplete(
669 struct xfs_da_args *args,
670 struct xfs_da_state *state)
671{
672 int error;
673
674 /*
675 * Fill in disk block numbers in the state structure
676 * so that we can get the buffers back after we commit
677 * several transactions in the following calls.
678 */
679 error = xfs_attr_fillstate(state);
680 if (error)
681 return error;
682
683 /*
684 * Mark the attribute as INCOMPLETE
685 */
686 return xfs_attr3_leaf_setflag(args);
687}
688
689/* Ensure the da state of an xattr deferred work item is ready to go. */
690static inline void
691xfs_attr_item_init_da_state(
692 struct xfs_attr_intent *attr)
693{
694 struct xfs_da_args *args = attr->xattri_da_args;
695
696 if (!attr->xattri_da_state)
697 attr->xattri_da_state = xfs_da_state_alloc(args);
698 else
699 xfs_da_state_reset(state: attr->xattri_da_state, args);
700}
701
702/*
703 * Initial setup for xfs_attr_node_removename. Make sure the attr is there and
704 * the blocks are valid. Attr keys with remote blocks will be marked
705 * incomplete.
706 */
707static
708int xfs_attr_node_removename_setup(
709 struct xfs_attr_intent *attr)
710{
711 struct xfs_da_args *args = attr->xattri_da_args;
712 struct xfs_da_state *state;
713 int error;
714
715 xfs_attr_item_init_da_state(attr);
716 error = xfs_attr_node_lookup(args, attr->xattri_da_state);
717 if (error != -EEXIST)
718 goto out;
719 error = 0;
720
721 state = attr->xattri_da_state;
722 ASSERT(state->path.blk[state->path.active - 1].bp != NULL);
723 ASSERT(state->path.blk[state->path.active - 1].magic ==
724 XFS_ATTR_LEAF_MAGIC);
725
726 error = xfs_attr_leaf_mark_incomplete(args, state);
727 if (error)
728 goto out;
729 if (args->rmtblkno > 0)
730 error = xfs_attr_rmtval_invalidate(args);
731out:
732 if (error) {
733 xfs_da_state_free(state: attr->xattri_da_state);
734 attr->xattri_da_state = NULL;
735 }
736
737 return error;
738}
739
740/*
741 * Remove the original attr we have just replaced. This is dependent on the
742 * original lookup and insert placing the old attr in args->blkno/args->index
743 * and the new attr in args->blkno2/args->index2.
744 */
745static int
746xfs_attr_leaf_remove_attr(
747 struct xfs_attr_intent *attr)
748{
749 struct xfs_da_args *args = attr->xattri_da_args;
750 struct xfs_inode *dp = args->dp;
751 struct xfs_buf *bp = NULL;
752 int forkoff;
753 int error;
754
755 error = xfs_attr3_leaf_read(args->trans, args->dp, args->owner,
756 args->blkno, &bp);
757 if (error)
758 return error;
759
760 xfs_attr3_leaf_remove(leaf_buffer: bp, args);
761
762 forkoff = xfs_attr_shortform_allfit(bp, dp);
763 if (forkoff)
764 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
765 /* bp is gone due to xfs_da_shrink_inode */
766
767 return error;
768}
769
770/*
771 * Shrink an attribute from leaf to shortform. Used by the node format remove
772 * path when the node format collapses to a single block and so we have to check
773 * if it can be collapsed further.
774 */
775static int
776xfs_attr_leaf_shrink(
777 struct xfs_da_args *args)
778{
779 struct xfs_inode *dp = args->dp;
780 struct xfs_buf *bp;
781 int forkoff;
782 int error;
783
784 if (!xfs_attr_is_leaf(dp))
785 return 0;
786
787 error = xfs_attr3_leaf_read(args->trans, args->dp, args->owner, 0, &bp);
788 if (error)
789 return error;
790
791 forkoff = xfs_attr_shortform_allfit(bp, dp);
792 if (forkoff) {
793 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
794 /* bp is gone due to xfs_da_shrink_inode */
795 } else {
796 xfs_trans_brelse(args->trans, bp);
797 }
798
799 return error;
800}
801
802/*
803 * Run the attribute operation specified in @attr.
804 *
805 * This routine is meant to function as a delayed operation and will set the
806 * state to XFS_DAS_DONE when the operation is complete. Calling functions will
807 * need to handle this, and recall the function until either an error or
808 * XFS_DAS_DONE is detected.
809 */
810int
811xfs_attr_set_iter(
812 struct xfs_attr_intent *attr)
813{
814 struct xfs_da_args *args = attr->xattri_da_args;
815 int error = 0;
816
817 /* State machine switch */
818next_state:
819 switch (attr->xattri_dela_state) {
820 case XFS_DAS_UNINIT:
821 ASSERT(0);
822 return -EFSCORRUPTED;
823 case XFS_DAS_SF_ADD:
824 return xfs_attr_sf_addname(attr);
825 case XFS_DAS_LEAF_ADD:
826 return xfs_attr_leaf_addname(attr);
827 case XFS_DAS_NODE_ADD:
828 return xfs_attr_node_addname(attr);
829
830 case XFS_DAS_SF_REMOVE:
831 error = xfs_attr_sf_removename(args);
832 attr->xattri_dela_state = xfs_attr_complete_op(attr,
833 replace_state: xfs_attr_init_add_state(args));
834 break;
835 case XFS_DAS_LEAF_REMOVE:
836 error = xfs_attr_leaf_removename(args);
837 attr->xattri_dela_state = xfs_attr_complete_op(attr,
838 replace_state: xfs_attr_init_add_state(args));
839 break;
840 case XFS_DAS_NODE_REMOVE:
841 error = xfs_attr_node_removename_setup(attr);
842 if (error == -ENOATTR &&
843 (args->op_flags & XFS_DA_OP_RECOVERY)) {
844 attr->xattri_dela_state = xfs_attr_complete_op(attr,
845 replace_state: xfs_attr_init_add_state(args));
846 error = 0;
847 break;
848 }
849 if (error)
850 return error;
851 attr->xattri_dela_state = XFS_DAS_NODE_REMOVE_RMT;
852 if (args->rmtblkno == 0)
853 attr->xattri_dela_state++;
854 break;
855
856 case XFS_DAS_LEAF_SET_RMT:
857 case XFS_DAS_NODE_SET_RMT:
858 error = xfs_attr_rmtval_find_space(attr);
859 if (error)
860 return error;
861 attr->xattri_dela_state++;
862 fallthrough;
863
864 case XFS_DAS_LEAF_ALLOC_RMT:
865 case XFS_DAS_NODE_ALLOC_RMT:
866 error = xfs_attr_rmtval_alloc(attr);
867 if (error)
868 return error;
869 if (attr->xattri_dela_state == XFS_DAS_DONE)
870 break;
871 goto next_state;
872
873 case XFS_DAS_LEAF_REPLACE:
874 case XFS_DAS_NODE_REPLACE:
875 /*
876 * We must "flip" the incomplete flags on the "new" and "old"
877 * attribute/value pairs so that one disappears and one appears
878 * atomically.
879 */
880 error = xfs_attr3_leaf_flipflags(args);
881 if (error)
882 return error;
883 /*
884 * We must commit the flag value change now to make it atomic
885 * and then we can start the next trans in series at REMOVE_OLD.
886 */
887 attr->xattri_dela_state++;
888 break;
889
890 case XFS_DAS_LEAF_REMOVE_OLD:
891 case XFS_DAS_NODE_REMOVE_OLD:
892 /*
893 * If we have a remote attr, start the process of removing it
894 * by invalidating any cached buffers.
895 *
896 * If we don't have a remote attr, we skip the remote block
897 * removal state altogether with a second state increment.
898 */
899 xfs_attr_restore_rmt_blk(args);
900 if (args->rmtblkno) {
901 error = xfs_attr_rmtval_invalidate(args);
902 if (error)
903 return error;
904 } else {
905 attr->xattri_dela_state++;
906 }
907
908 attr->xattri_dela_state++;
909 goto next_state;
910
911 case XFS_DAS_LEAF_REMOVE_RMT:
912 case XFS_DAS_NODE_REMOVE_RMT:
913 error = xfs_attr_rmtval_remove(attr);
914 if (error == -EAGAIN) {
915 error = 0;
916 break;
917 }
918 if (error)
919 return error;
920
921 /*
922 * We've finished removing the remote attr blocks, so commit the
923 * transaction and move on to removing the attr name from the
924 * leaf/node block. Removing the attr might require a full
925 * transaction reservation for btree block freeing, so we
926 * can't do that in the same transaction where we removed the
927 * remote attr blocks.
928 */
929 attr->xattri_dela_state++;
930 break;
931
932 case XFS_DAS_LEAF_REMOVE_ATTR:
933 error = xfs_attr_leaf_remove_attr(attr);
934 attr->xattri_dela_state = xfs_attr_complete_op(attr,
935 replace_state: xfs_attr_init_add_state(args));
936 break;
937
938 case XFS_DAS_NODE_REMOVE_ATTR:
939 error = xfs_attr_node_remove_attr(attr);
940 if (!error)
941 error = xfs_attr_leaf_shrink(args);
942 attr->xattri_dela_state = xfs_attr_complete_op(attr,
943 replace_state: xfs_attr_init_add_state(args));
944 break;
945 default:
946 ASSERT(0);
947 break;
948 }
949
950 trace_xfs_attr_set_iter_return(attr->xattri_dela_state, args->dp);
951 return error;
952}
953
954
955/*
956 * Return EEXIST if attr is found, or ENOATTR if not
957 */
958static int
959xfs_attr_lookup(
960 struct xfs_da_args *args)
961{
962 struct xfs_inode *dp = args->dp;
963 struct xfs_buf *bp = NULL;
964 struct xfs_da_state *state;
965 int error;
966
967 if (!xfs_inode_hasattr(dp))
968 return -ENOATTR;
969
970 if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL) {
971 if (xfs_attr_sf_findname(args))
972 return -EEXIST;
973 return -ENOATTR;
974 }
975
976 /* Prerequisite for xfs_attr_is_leaf */
977 error = xfs_iread_extents(args->trans, args->dp, XFS_ATTR_FORK);
978 if (error)
979 return error;
980
981 if (xfs_attr_is_leaf(dp)) {
982 error = xfs_attr_leaf_hasname(args, &bp);
983
984 if (bp)
985 xfs_trans_brelse(args->trans, bp);
986
987 return error;
988 }
989
990 state = xfs_da_state_alloc(args);
991 error = xfs_attr_node_lookup(args, state);
992 xfs_da_state_free(state);
993 return error;
994}
995
996int
997xfs_attr_add_fork(
998 struct xfs_inode *ip, /* incore inode pointer */
999 int size, /* space new attribute needs */
1000 int rsvd) /* xact may use reserved blks */
1001{
1002 struct xfs_mount *mp = ip->i_mount;
1003 struct xfs_trans *tp; /* transaction pointer */
1004 unsigned int blks; /* space reservation */
1005 int error; /* error return value */
1006
1007 if (!xfs_is_metadir_inode(ip))
1008 ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1009
1010 blks = XFS_ADDAFORK_SPACE_RES(mp);
1011
1012 error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_addafork, blks, 0,
1013 rsvd, &tp);
1014 if (error)
1015 return error;
1016
1017 if (xfs_inode_has_attr_fork(ip))
1018 goto trans_cancel;
1019
1020 error = xfs_bmap_add_attrfork(tp, ip, size, rsvd);
1021 if (error)
1022 goto trans_cancel;
1023
1024 error = xfs_trans_commit(tp);
1025 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1026 return error;
1027
1028trans_cancel:
1029 xfs_trans_cancel(tp);
1030 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1031 return error;
1032}
1033
1034/*
1035 * Make a change to the xattr structure.
1036 *
1037 * The caller must have initialized @args, attached dquots, and must not hold
1038 * any ILOCKs. Reserved data blocks may be used if @rsvd is set.
1039 *
1040 * Returns -EEXIST for XFS_ATTRUPDATE_CREATE if the name already exists.
1041 * Returns -ENOATTR for XFS_ATTRUPDATE_REMOVE if the name does not exist.
1042 * Returns 0 on success, or a negative errno if something else went wrong.
1043 */
1044int
1045xfs_attr_set(
1046 struct xfs_da_args *args,
1047 enum xfs_attr_update op,
1048 bool rsvd)
1049{
1050 struct xfs_inode *dp = args->dp;
1051 struct xfs_mount *mp = dp->i_mount;
1052 struct xfs_trans_res tres;
1053 int error, local;
1054 int rmt_blks = 0;
1055 unsigned int total = 0;
1056
1057 ASSERT(!args->trans);
1058
1059 switch (op) {
1060 case XFS_ATTRUPDATE_UPSERT:
1061 case XFS_ATTRUPDATE_CREATE:
1062 case XFS_ATTRUPDATE_REPLACE:
1063 XFS_STATS_INC(mp, xs_attr_set);
1064 args->total = xfs_attr_calc_size(args, local: &local);
1065
1066 /*
1067 * If the inode doesn't have an attribute fork, add one.
1068 * (inode must not be locked when we call this routine)
1069 */
1070 if (xfs_inode_has_attr_fork(dp) == 0) {
1071 int sf_size = sizeof(struct xfs_attr_sf_hdr) +
1072 xfs_attr_sf_entsize_byname(args->namelen,
1073 args->valuelen);
1074
1075 error = xfs_attr_add_fork(ip: dp, size: sf_size, rsvd: rsvd);
1076 if (error)
1077 return error;
1078 }
1079
1080 if (!local)
1081 rmt_blks = xfs_attr3_rmt_blocks(mp, attrlen: args->valuelen);
1082
1083 tres = xfs_attr_set_resv(args);
1084 total = args->total;
1085 break;
1086 case XFS_ATTRUPDATE_REMOVE:
1087 XFS_STATS_INC(mp, xs_attr_remove);
1088 rmt_blks = xfs_attr3_max_rmt_blocks(mp);
1089 tres = M_RES(mp)->tr_attrrm;
1090 total = XFS_ATTRRM_SPACE_RES(mp);
1091 break;
1092 }
1093
1094 /*
1095 * Root fork attributes can use reserved data blocks for this
1096 * operation if necessary
1097 */
1098 error = xfs_trans_alloc_inode(dp, &tres, total, 0, rsvd, &args->trans);
1099 if (error)
1100 return error;
1101
1102 if (op != XFS_ATTRUPDATE_REMOVE || xfs_inode_hasattr(ip: dp)) {
1103 error = xfs_iext_count_extend(args->trans, dp, XFS_ATTR_FORK,
1104 XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
1105 if (error)
1106 goto out_trans_cancel;
1107 }
1108
1109 error = xfs_attr_lookup(args);
1110 switch (error) {
1111 case -EEXIST:
1112 if (op == XFS_ATTRUPDATE_REMOVE) {
1113 /* if no value, we are performing a remove operation */
1114 xfs_attr_defer_add(args, XFS_ATTR_DEFER_REMOVE);
1115 break;
1116 }
1117
1118 /* Pure create fails if the attr already exists */
1119 if (op == XFS_ATTRUPDATE_CREATE)
1120 goto out_trans_cancel;
1121 xfs_attr_defer_add(args, XFS_ATTR_DEFER_REPLACE);
1122 break;
1123 case -ENOATTR:
1124 /* Can't remove what isn't there. */
1125 if (op == XFS_ATTRUPDATE_REMOVE)
1126 goto out_trans_cancel;
1127
1128 /* Pure replace fails if no existing attr to replace. */
1129 if (op == XFS_ATTRUPDATE_REPLACE)
1130 goto out_trans_cancel;
1131 xfs_attr_defer_add(args, XFS_ATTR_DEFER_SET);
1132 break;
1133 default:
1134 goto out_trans_cancel;
1135 }
1136
1137 /*
1138 * If this is a synchronous mount, make sure that the
1139 * transaction goes to disk before returning to the user.
1140 */
1141 if (xfs_has_wsync(mp))
1142 xfs_trans_set_sync(args->trans);
1143
1144 xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
1145
1146 /*
1147 * Commit the last in the sequence of transactions.
1148 */
1149 xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
1150 error = xfs_trans_commit(args->trans);
1151out_unlock:
1152 xfs_iunlock(dp, XFS_ILOCK_EXCL);
1153 args->trans = NULL;
1154 return error;
1155
1156out_trans_cancel:
1157 if (args->trans)
1158 xfs_trans_cancel(args->trans);
1159 goto out_unlock;
1160}
1161
1162/*========================================================================
1163 * External routines when attribute list is inside the inode
1164 *========================================================================*/
1165
1166int xfs_attr_sf_totsize(struct xfs_inode *dp)
1167{
1168 struct xfs_attr_sf_hdr *sf = dp->i_af.if_data;
1169
1170 return be16_to_cpu(sf->totsize);
1171}
1172
1173/*
1174 * Add a name to the shortform attribute list structure
1175 * This is the external routine.
1176 */
1177static int
1178xfs_attr_shortform_addname(
1179 struct xfs_da_args *args)
1180{
1181 int newsize, forkoff;
1182
1183 trace_xfs_attr_sf_addname(args);
1184
1185 if (xfs_attr_sf_findname(args)) {
1186 int error;
1187
1188 ASSERT(args->op_flags & XFS_DA_OP_REPLACE);
1189
1190 error = xfs_attr_sf_removename(args);
1191 if (error)
1192 return error;
1193
1194 /*
1195 * Since we have removed the old attr, clear XFS_DA_OP_REPLACE
1196 * so that the new attr doesn't fit in shortform format, the
1197 * leaf format add routine won't trip over the attr not being
1198 * around.
1199 */
1200 args->op_flags &= ~XFS_DA_OP_REPLACE;
1201 } else {
1202 ASSERT(!(args->op_flags & XFS_DA_OP_REPLACE));
1203 }
1204
1205 if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX ||
1206 args->valuelen >= XFS_ATTR_SF_ENTSIZE_MAX)
1207 return -ENOSPC;
1208
1209 newsize = xfs_attr_sf_totsize(dp: args->dp);
1210 newsize += xfs_attr_sf_entsize_byname(args->namelen, args->valuelen);
1211
1212 forkoff = xfs_attr_shortform_bytesfit(dp: args->dp, bytes: newsize);
1213 if (!forkoff)
1214 return -ENOSPC;
1215
1216 xfs_attr_shortform_add(args, forkoff);
1217 return 0;
1218}
1219
1220
1221/*========================================================================
1222 * External routines when attribute list is one block
1223 *========================================================================*/
1224
1225/*
1226 * Return EEXIST if attr is found, or ENOATTR if not
1227 */
1228STATIC int
1229xfs_attr_leaf_hasname(
1230 struct xfs_da_args *args,
1231 struct xfs_buf **bp)
1232{
1233 int error = 0;
1234
1235 error = xfs_attr3_leaf_read(args->trans, args->dp, args->owner, 0, bp);
1236 if (error)
1237 return error;
1238
1239 error = xfs_attr3_leaf_lookup_int(leaf: *bp, args);
1240 if (error != -ENOATTR && error != -EEXIST)
1241 xfs_trans_brelse(args->trans, *bp);
1242
1243 return error;
1244}
1245
1246/*
1247 * Remove a name from the leaf attribute list structure
1248 *
1249 * This leaf block cannot have a "remote" value, we only call this routine
1250 * if bmap_one_block() says there is only one block (ie: no remote blks).
1251 */
1252STATIC int
1253xfs_attr_leaf_removename(
1254 struct xfs_da_args *args)
1255{
1256 struct xfs_inode *dp;
1257 struct xfs_buf *bp;
1258 int error, forkoff;
1259
1260 trace_xfs_attr_leaf_removename(args);
1261
1262 /*
1263 * Remove the attribute.
1264 */
1265 dp = args->dp;
1266
1267 error = xfs_attr_leaf_hasname(args, &bp);
1268 if (error == -ENOATTR) {
1269 xfs_trans_brelse(args->trans, bp);
1270 if (args->op_flags & XFS_DA_OP_RECOVERY)
1271 return 0;
1272 return error;
1273 } else if (error != -EEXIST)
1274 return error;
1275
1276 xfs_attr3_leaf_remove(leaf_buffer: bp, args);
1277
1278 /*
1279 * If the result is small enough, shrink it all into the inode.
1280 */
1281 forkoff = xfs_attr_shortform_allfit(bp, dp);
1282 if (forkoff)
1283 return xfs_attr3_leaf_to_shortform(bp, args, forkoff);
1284 /* bp is gone due to xfs_da_shrink_inode */
1285
1286 return 0;
1287}
1288
1289/*
1290 * Look up a name in a leaf attribute list structure.
1291 *
1292 * This leaf block cannot have a "remote" value, we only call this routine
1293 * if bmap_one_block() says there is only one block (ie: no remote blks).
1294 *
1295 * Returns 0 on successful retrieval, otherwise an error.
1296 */
1297STATIC int
1298xfs_attr_leaf_get(xfs_da_args_t *args)
1299{
1300 struct xfs_buf *bp;
1301 int error;
1302
1303 trace_xfs_attr_leaf_get(args);
1304
1305 error = xfs_attr_leaf_hasname(args, &bp);
1306
1307 if (error == -ENOATTR) {
1308 xfs_trans_brelse(args->trans, bp);
1309 return error;
1310 } else if (error != -EEXIST)
1311 return error;
1312
1313
1314 error = xfs_attr3_leaf_getvalue(bp, args);
1315 xfs_trans_brelse(args->trans, bp);
1316 return error;
1317}
1318
1319/* Return EEXIST if attr is found, or ENOATTR if not. */
1320STATIC int
1321xfs_attr_node_lookup(
1322 struct xfs_da_args *args,
1323 struct xfs_da_state *state)
1324{
1325 int retval, error;
1326
1327 /*
1328 * Search to see if name exists, and get back a pointer to it.
1329 */
1330 error = xfs_da3_node_lookup_int(state, result: &retval);
1331 if (error)
1332 return error;
1333
1334 return retval;
1335}
1336
1337/*========================================================================
1338 * External routines when attribute list size > geo->blksize
1339 *========================================================================*/
1340
1341STATIC int
1342xfs_attr_node_addname_find_attr(
1343 struct xfs_attr_intent *attr)
1344{
1345 struct xfs_da_args *args = attr->xattri_da_args;
1346 int error;
1347
1348 /*
1349 * Search to see if name already exists, and get back a pointer
1350 * to where it should go.
1351 */
1352 xfs_attr_item_init_da_state(attr);
1353 error = xfs_attr_node_lookup(args, attr->xattri_da_state);
1354 switch (error) {
1355 case -ENOATTR:
1356 if (args->op_flags & XFS_DA_OP_REPLACE)
1357 goto error;
1358 break;
1359 case -EEXIST:
1360 if (!(args->op_flags & XFS_DA_OP_REPLACE))
1361 goto error;
1362
1363
1364 trace_xfs_attr_node_replace(args);
1365 /*
1366 * Save the existing remote attr state so that the current
1367 * values reflect the state of the new attribute we are about to
1368 * add, not the attribute we just found and will remove later.
1369 */
1370 xfs_attr_save_rmt_blk(args);
1371 break;
1372 case 0:
1373 break;
1374 default:
1375 goto error;
1376 }
1377
1378 return 0;
1379error:
1380 if (attr->xattri_da_state) {
1381 xfs_da_state_free(state: attr->xattri_da_state);
1382 attr->xattri_da_state = NULL;
1383 }
1384 return error;
1385}
1386
1387/*
1388 * Add a name to a Btree-format attribute list.
1389 *
1390 * This will involve walking down the Btree, and may involve splitting leaf
1391 * nodes and even splitting intermediate nodes up to and including the root
1392 * node (a special case of an intermediate node).
1393 *
1394 * If the tree was still in single leaf format and needs to converted to
1395 * real node format return 1 and let the caller handle that.
1396 */
1397static int
1398xfs_attr_node_try_addname(
1399 struct xfs_attr_intent *attr)
1400{
1401 struct xfs_da_state *state = attr->xattri_da_state;
1402 struct xfs_da_state_blk *blk;
1403 int error = 0;
1404
1405 trace_xfs_attr_node_addname(state->args);
1406
1407 blk = &state->path.blk[state->path.active-1];
1408 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1409
1410 if (!xfs_attr3_leaf_add(blk->bp, state->args)) {
1411 if (state->path.active == 1) {
1412 /*
1413 * Its really a single leaf node, but it had
1414 * out-of-line values so it looked like it *might*
1415 * have been a b-tree. Let the caller deal with this.
1416 */
1417 error = 1;
1418 goto out;
1419 }
1420
1421 /*
1422 * Split as many Btree elements as required.
1423 * This code tracks the new and old attr's location
1424 * in the index/blkno/rmtblkno/rmtblkcnt fields and
1425 * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
1426 */
1427 error = xfs_da3_split(state);
1428 if (error)
1429 goto out;
1430 } else {
1431 /*
1432 * Addition succeeded, update Btree hashvals.
1433 */
1434 xfs_da3_fixhashpath(state, path_to_to_fix: &state->path);
1435 }
1436
1437out:
1438 xfs_da_state_free(state);
1439 attr->xattri_da_state = NULL;
1440 return error;
1441}
1442
1443static int
1444xfs_attr_node_removename(
1445 struct xfs_da_args *args,
1446 struct xfs_da_state *state)
1447{
1448 struct xfs_da_state_blk *blk;
1449 int retval;
1450
1451 /*
1452 * Remove the name and update the hashvals in the tree.
1453 */
1454 blk = &state->path.blk[state->path.active-1];
1455 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1456 retval = xfs_attr3_leaf_remove(leaf_buffer: blk->bp, args);
1457 xfs_da3_fixhashpath(state, path_to_to_fix: &state->path);
1458
1459 return retval;
1460}
1461
1462static int
1463xfs_attr_node_remove_attr(
1464 struct xfs_attr_intent *attr)
1465{
1466 struct xfs_da_args *args = attr->xattri_da_args;
1467 struct xfs_da_state *state = xfs_da_state_alloc(args);
1468 int retval = 0;
1469 int error = 0;
1470
1471 /*
1472 * The attr we are removing has already been marked incomplete, so
1473 * we need to set the filter appropriately to re-find the "old"
1474 * attribute entry after any split ops.
1475 */
1476 args->attr_filter |= XFS_ATTR_INCOMPLETE;
1477 error = xfs_da3_node_lookup_int(state, result: &retval);
1478 if (error)
1479 goto out;
1480
1481 error = xfs_attr_node_removename(args, state);
1482
1483 /*
1484 * Check to see if the tree needs to be collapsed.
1485 */
1486 if (retval && (state->path.active > 1)) {
1487 error = xfs_da3_join(state);
1488 if (error)
1489 goto out;
1490 }
1491 retval = error = 0;
1492
1493out:
1494 xfs_da_state_free(state);
1495 if (error)
1496 return error;
1497 return retval;
1498}
1499
1500/*
1501 * Retrieve the attribute data from a node attribute list.
1502 *
1503 * This routine gets called for any attribute fork that has more than one
1504 * block, ie: both true Btree attr lists and for single-leaf-blocks with
1505 * "remote" values taking up more blocks.
1506 *
1507 * Returns 0 on successful retrieval, otherwise an error.
1508 */
1509STATIC int
1510xfs_attr_node_get(
1511 struct xfs_da_args *args)
1512{
1513 struct xfs_da_state *state;
1514 struct xfs_da_state_blk *blk;
1515 int i;
1516 int error;
1517
1518 trace_xfs_attr_node_get(args);
1519
1520 /*
1521 * Search to see if name exists, and get back a pointer to it.
1522 */
1523 state = xfs_da_state_alloc(args);
1524 error = xfs_attr_node_lookup(args, state);
1525 if (error != -EEXIST)
1526 goto out_release;
1527
1528 /*
1529 * Get the value, local or "remote"
1530 */
1531 blk = &state->path.blk[state->path.active - 1];
1532 error = xfs_attr3_leaf_getvalue(bp: blk->bp, args);
1533
1534 /*
1535 * If not in a transaction, we have to release all the buffers.
1536 */
1537out_release:
1538 for (i = 0; i < state->path.active; i++) {
1539 xfs_trans_brelse(args->trans, state->path.blk[i].bp);
1540 state->path.blk[i].bp = NULL;
1541 }
1542
1543 xfs_da_state_free(state);
1544 return error;
1545}
1546
1547/* Enforce that there is at most one namespace bit per attr. */
1548inline bool xfs_attr_check_namespace(unsigned int attr_flags)
1549{
1550 return hweight32(attr_flags & XFS_ATTR_NSP_ONDISK_MASK) < 2;
1551}
1552
1553/* Returns true if the attribute entry name is valid. */
1554bool
1555xfs_attr_namecheck(
1556 unsigned int attr_flags,
1557 const void *name,
1558 size_t length)
1559{
1560 /* Only one namespace bit allowed. */
1561 if (!xfs_attr_check_namespace(attr_flags))
1562 return false;
1563
1564 /*
1565 * MAXNAMELEN includes the trailing null, but (name/length) leave it
1566 * out, so use >= for the length check.
1567 */
1568 if (length >= MAXNAMELEN)
1569 return false;
1570
1571 /* Parent pointers have their own validation. */
1572 if (attr_flags & XFS_ATTR_PARENT)
1573 return xfs_parent_namecheck(attr_flags, name, length);
1574
1575 /* There shouldn't be any nulls here */
1576 return !memchr(name, 0, length);
1577}
1578
1579int __init
1580xfs_attr_intent_init_cache(void)
1581{
1582 xfs_attr_intent_cache = kmem_cache_create("xfs_attr_intent",
1583 sizeof(struct xfs_attr_intent),
1584 0, 0, NULL);
1585
1586 return xfs_attr_intent_cache != NULL ? 0 : -ENOMEM;
1587}
1588
1589void
1590xfs_attr_intent_destroy_cache(void)
1591{
1592 kmem_cache_destroy(xfs_attr_intent_cache);
1593 xfs_attr_intent_cache = NULL;
1594}
1595

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