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
28 /*
29 * xfs_attr.c
30 *
31 * Provide the external interfaces to manage attribute lists.
32 */
33
34 /*========================================================================
35 * Function prototypes for the kernel.
36 *========================================================================*/
37
38 /*
39 * Internal routines when attribute list fits inside the inode.
40 */
41 STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);
42
43 /*
44 * Internal routines when attribute list is one block.
45 */
46 STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
47 STATIC int xfs_attr_leaf_addname(xfs_da_args_t *args);
48 STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
49
50 /*
51 * Internal routines when attribute list is more than one block.
52 */
53 STATIC int xfs_attr_node_get(xfs_da_args_t *args);
54 STATIC int xfs_attr_node_addname(xfs_da_args_t *args);
55 STATIC int xfs_attr_node_removename(xfs_da_args_t *args);
56 STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
57 STATIC int xfs_attr_refillstate(xfs_da_state_t *state);
58
59
60 STATIC int
61 xfs_attr_args_init(
62 struct xfs_da_args *args,
63 struct xfs_inode *dp,
64 const unsigned char *name,
65 int flags)
66 {
67
68 if (!name)
69 return -EINVAL;
70
71 memset(args, 0, sizeof(*args));
72 args->geo = dp->i_mount->m_attr_geo;
73 args->whichfork = XFS_ATTR_FORK;
74 args->dp = dp;
75 args->flags = flags;
76 args->name = name;
77 args->namelen = strlen((const char *)name);
78 if (args->namelen >= MAXNAMELEN)
79 return -EFAULT; /* match IRIX behaviour */
80
81 args->hashval = xfs_da_hashname(args->name, args->namelen);
82 return 0;
83 }
84
85 int
86 xfs_inode_hasattr(
87 struct xfs_inode *ip)
88 {
89 if (!XFS_IFORK_Q(ip) ||
90 (ip->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
91 ip->i_d.di_anextents == 0))
92 return 0;
93 return 1;
94 }
95
96 /*========================================================================
97 * Overall external interface routines.
98 *========================================================================*/
99
100 /*
101 * Retrieve an extended attribute and its value. Must have ilock.
102 * Returns 0 on successful retrieval, otherwise an error.
103 */
104 int
105 xfs_attr_get_ilocked(
106 struct xfs_inode *ip,
107 struct xfs_da_args *args)
108 {
109 ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
110
111 if (!xfs_inode_hasattr(ip))
112 return -ENOATTR;
113 else if (ip->i_d.di_aformat == XFS_DINODE_FMT_LOCAL)
114 return xfs_attr_shortform_getvalue(args);
115 else if (xfs_bmap_one_block(ip, XFS_ATTR_FORK))
116 return xfs_attr_leaf_get(args);
117 else
118 return xfs_attr_node_get(args);
119 }
120
121 /*
122 * Retrieve an extended attribute by name, and its value if requested.
123 *
124 * If ATTR_KERNOVAL is set in @flags, then the caller does not want the value,
125 * just an indication whether the attribute exists and the size of the value if
126 * it exists. The size is returned in @valuelenp,
127 *
128 * If the attribute is found, but exceeds the size limit set by the caller in
129 * @valuelenp, return -ERANGE with the size of the attribute that was found in
130 * @valuelenp.
131 *
132 * If ATTR_ALLOC is set in @flags, allocate the buffer for the value after
133 * existence of the attribute has been determined. On success, return that
134 * buffer to the caller and leave them to free it. On failure, free any
135 * allocated buffer and ensure the buffer pointer returned to the caller is
136 * null.
137 */
138 int
139 xfs_attr_get(
140 struct xfs_inode *ip,
141 const unsigned char *name,
142 unsigned char **value,
143 int *valuelenp,
144 int flags)
145 {
146 struct xfs_da_args args;
147 uint lock_mode;
148 int error;
149
150 ASSERT((flags & (ATTR_ALLOC | ATTR_KERNOVAL)) || *value);
151
152 XFS_STATS_INC(ip->i_mount, xs_attr_get);
153
154 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
155 return -EIO;
156
157 error = xfs_attr_args_init(&args, ip, name, flags);
158 if (error)
159 return error;
160
161 /* Entirely possible to look up a name which doesn't exist */
162 args.op_flags = XFS_DA_OP_OKNOENT;
163 if (flags & ATTR_ALLOC)
164 args.op_flags |= XFS_DA_OP_ALLOCVAL;
165 else
166 args.value = *value;
167 args.valuelen = *valuelenp;
168
169 lock_mode = xfs_ilock_attr_map_shared(ip);
170 error = xfs_attr_get_ilocked(ip, &args);
171 xfs_iunlock(ip, lock_mode);
172 *valuelenp = args.valuelen;
173
174 /* on error, we have to clean up allocated value buffers */
175 if (error) {
176 if (flags & ATTR_ALLOC) {
177 kmem_free(args.value);
178 *value = NULL;
179 }
180 return error;
181 }
182 *value = args.value;
183 return 0;
184 }
185
186 /*
187 * Calculate how many blocks we need for the new attribute,
188 */
189 STATIC int
190 xfs_attr_calc_size(
191 struct xfs_da_args *args,
192 int *local)
193 {
194 struct xfs_mount *mp = args->dp->i_mount;
195 int size;
196 int nblks;
197
198 /*
199 * Determine space new attribute will use, and if it would be
200 * "local" or "remote" (note: local != inline).
201 */
202 size = xfs_attr_leaf_newentsize(args, local);
203 nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
204 if (*local) {
205 if (size > (args->geo->blksize / 2)) {
206 /* Double split possible */
207 nblks *= 2;
208 }
209 } else {
210 /*
211 * Out of line attribute, cannot double split, but
212 * make room for the attribute value itself.
213 */
214 uint dblocks = xfs_attr3_rmt_blocks(mp, args->valuelen);
215 nblks += dblocks;
216 nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
217 }
218
219 return nblks;
220 }
221
222 STATIC int
223 xfs_attr_try_sf_addname(
224 struct xfs_inode *dp,
225 struct xfs_da_args *args)
226 {
227
228 struct xfs_mount *mp = dp->i_mount;
229 int error, error2;
230
231 error = xfs_attr_shortform_addname(args);
232 if (error == -ENOSPC)
233 return error;
234
235 /*
236 * Commit the shortform mods, and we're done.
237 * NOTE: this is also the error path (EEXIST, etc).
238 */
239 if (!error && (args->flags & ATTR_KERNOTIME) == 0)
240 xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
241
242 if (mp->m_flags & XFS_MOUNT_WSYNC)
243 xfs_trans_set_sync(args->trans);
244
245 error2 = xfs_trans_commit(args->trans);
246 args->trans = NULL;
247 return error ? error : error2;
248 }
249
250 /*
251 * Set the attribute specified in @args.
252 */
253 int
254 xfs_attr_set_args(
255 struct xfs_da_args *args)
256 {
257 struct xfs_inode *dp = args->dp;
258 struct xfs_buf *leaf_bp = NULL;
259 int error;
260
261 /*
262 * If the attribute list is non-existent or a shortform list,
263 * upgrade it to a single-leaf-block attribute list.
264 */
265 if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL ||
266 (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
267 dp->i_d.di_anextents == 0)) {
268
269 /*
270 * Build initial attribute list (if required).
271 */
272 if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS)
273 xfs_attr_shortform_create(args);
274
275 /*
276 * Try to add the attr to the attribute list in the inode.
277 */
278 error = xfs_attr_try_sf_addname(dp, args);
279 if (error != -ENOSPC)
280 return error;
281
282 /*
283 * It won't fit in the shortform, transform to a leaf block.
284 * GROT: another possible req'mt for a double-split btree op.
285 */
286 error = xfs_attr_shortform_to_leaf(args, &leaf_bp);
287 if (error)
288 return error;
289
290 /*
291 * Prevent the leaf buffer from being unlocked so that a
292 * concurrent AIL push cannot grab the half-baked leaf
293 * buffer and run into problems with the write verifier.
294 * Once we're done rolling the transaction we can release
295 * the hold and add the attr to the leaf.
296 */
297 xfs_trans_bhold(args->trans, leaf_bp);
298 error = xfs_defer_finish(&args->trans);
299 xfs_trans_bhold_release(args->trans, leaf_bp);
300 if (error) {
301 xfs_trans_brelse(args->trans, leaf_bp);
302 return error;
303 }
304 }
305
306 if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
307 error = xfs_attr_leaf_addname(args);
308 else
309 error = xfs_attr_node_addname(args);
310 return error;
311 }
312
313 /*
314 * Remove the attribute specified in @args.
315 */
316 int
317 xfs_attr_remove_args(
318 struct xfs_da_args *args)
319 {
320 struct xfs_inode *dp = args->dp;
321 int error;
322
323 if (!xfs_inode_hasattr(dp)) {
324 error = -ENOATTR;
325 } else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
326 ASSERT(dp->i_afp->if_flags & XFS_IFINLINE);
327 error = xfs_attr_shortform_remove(args);
328 } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
329 error = xfs_attr_leaf_removename(args);
330 } else {
331 error = xfs_attr_node_removename(args);
332 }
333
334 return error;
335 }
336
337 int
338 xfs_attr_set(
339 struct xfs_inode *dp,
340 const unsigned char *name,
341 unsigned char *value,
342 int valuelen,
343 int flags)
344 {
345 struct xfs_mount *mp = dp->i_mount;
346 struct xfs_da_args args;
347 struct xfs_trans_res tres;
348 int rsvd = (flags & ATTR_ROOT) != 0;
349 int error, local;
350
351 XFS_STATS_INC(mp, xs_attr_set);
352
353 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
354 return -EIO;
355
356 error = xfs_attr_args_init(&args, dp, name, flags);
357 if (error)
358 return error;
359
360 args.value = value;
361 args.valuelen = valuelen;
362 args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
363 args.total = xfs_attr_calc_size(&args, &local);
364
365 error = xfs_qm_dqattach(dp);
366 if (error)
367 return error;
368
369 /*
370 * If the inode doesn't have an attribute fork, add one.
371 * (inode must not be locked when we call this routine)
372 */
373 if (XFS_IFORK_Q(dp) == 0) {
374 int sf_size = sizeof(xfs_attr_sf_hdr_t) +
375 XFS_ATTR_SF_ENTSIZE_BYNAME(args.namelen, valuelen);
376
377 error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
378 if (error)
379 return error;
380 }
381
382 tres.tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
383 M_RES(mp)->tr_attrsetrt.tr_logres * args.total;
384 tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;
385 tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
386
387 /*
388 * Root fork attributes can use reserved data blocks for this
389 * operation if necessary
390 */
391 error = xfs_trans_alloc(mp, &tres, args.total, 0,
392 rsvd ? XFS_TRANS_RESERVE : 0, &args.trans);
393 if (error)
394 return error;
395
396 xfs_ilock(dp, XFS_ILOCK_EXCL);
397 error = xfs_trans_reserve_quota_nblks(args.trans, dp, args.total, 0,
398 rsvd ? XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES :
399 XFS_QMOPT_RES_REGBLKS);
400 if (error)
401 goto out_trans_cancel;
402
403 xfs_trans_ijoin(args.trans, dp, 0);
404 error = xfs_attr_set_args(&args);
405 if (error)
406 goto out_trans_cancel;
407 if (!args.trans) {
408 /* shortform attribute has already been committed */
409 goto out_unlock;
410 }
411
412 /*
413 * If this is a synchronous mount, make sure that the
414 * transaction goes to disk before returning to the user.
415 */
416 if (mp->m_flags & XFS_MOUNT_WSYNC)
417 xfs_trans_set_sync(args.trans);
418
419 if ((flags & ATTR_KERNOTIME) == 0)
420 xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);
421
422 /*
423 * Commit the last in the sequence of transactions.
424 */
425 xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
426 error = xfs_trans_commit(args.trans);
427 out_unlock:
428 xfs_iunlock(dp, XFS_ILOCK_EXCL);
429 return error;
430
431 out_trans_cancel:
432 if (args.trans)
433 xfs_trans_cancel(args.trans);
434 goto out_unlock;
435 }
436
437 /*
438 * Generic handler routine to remove a name from an attribute list.
439 * Transitions attribute list from Btree to shortform as necessary.
440 */
441 int
442 xfs_attr_remove(
443 struct xfs_inode *dp,
444 const unsigned char *name,
445 int flags)
446 {
447 struct xfs_mount *mp = dp->i_mount;
448 struct xfs_da_args args;
449 int error;
450
451 XFS_STATS_INC(mp, xs_attr_remove);
452
453 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
454 return -EIO;
455
456 error = xfs_attr_args_init(&args, dp, name, flags);
457 if (error)
458 return error;
459
460 /*
461 * we have no control over the attribute names that userspace passes us
462 * to remove, so we have to allow the name lookup prior to attribute
463 * removal to fail.
464 */
465 args.op_flags = XFS_DA_OP_OKNOENT;
466
467 error = xfs_qm_dqattach(dp);
468 if (error)
469 return error;
470
471 /*
472 * Root fork attributes can use reserved data blocks for this
473 * operation if necessary
474 */
475 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_attrrm,
476 XFS_ATTRRM_SPACE_RES(mp), 0,
477 (flags & ATTR_ROOT) ? XFS_TRANS_RESERVE : 0,
478 &args.trans);
479 if (error)
480 return error;
481
482 xfs_ilock(dp, XFS_ILOCK_EXCL);
483 /*
484 * No need to make quota reservations here. We expect to release some
485 * blocks not allocate in the common case.
486 */
487 xfs_trans_ijoin(args.trans, dp, 0);
488
489 error = xfs_attr_remove_args(&args);
490 if (error)
491 goto out;
492
493 /*
494 * If this is a synchronous mount, make sure that the
495 * transaction goes to disk before returning to the user.
496 */
497 if (mp->m_flags & XFS_MOUNT_WSYNC)
498 xfs_trans_set_sync(args.trans);
499
500 if ((flags & ATTR_KERNOTIME) == 0)
501 xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);
502
503 /*
504 * Commit the last in the sequence of transactions.
505 */
506 xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
507 error = xfs_trans_commit(args.trans);
508 xfs_iunlock(dp, XFS_ILOCK_EXCL);
509
510 return error;
511
512 out:
513 if (args.trans)
514 xfs_trans_cancel(args.trans);
515 xfs_iunlock(dp, XFS_ILOCK_EXCL);
516 return error;
517 }
518
519 /*========================================================================
520 * External routines when attribute list is inside the inode
521 *========================================================================*/
522
523 /*
524 * Add a name to the shortform attribute list structure
525 * This is the external routine.
526 */
527 STATIC int
528 xfs_attr_shortform_addname(xfs_da_args_t *args)
529 {
530 int newsize, forkoff, retval;
531
532 trace_xfs_attr_sf_addname(args);
533
534 retval = xfs_attr_shortform_lookup(args);
535 if ((args->flags & ATTR_REPLACE) && (retval == -ENOATTR)) {
536 return retval;
537 } else if (retval == -EEXIST) {
538 if (args->flags & ATTR_CREATE)
539 return retval;
540 retval = xfs_attr_shortform_remove(args);
541 if (retval)
542 return retval;
543 /*
544 * Since we have removed the old attr, clear ATTR_REPLACE so
545 * that the leaf format add routine won't trip over the attr
546 * not being around.
547 */
548 args->flags &= ~ATTR_REPLACE;
549 }
550
551 if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX ||
552 args->valuelen >= XFS_ATTR_SF_ENTSIZE_MAX)
553 return -ENOSPC;
554
555 newsize = XFS_ATTR_SF_TOTSIZE(args->dp);
556 newsize += XFS_ATTR_SF_ENTSIZE_BYNAME(args->namelen, args->valuelen);
557
558 forkoff = xfs_attr_shortform_bytesfit(args->dp, newsize);
559 if (!forkoff)
560 return -ENOSPC;
561
562 xfs_attr_shortform_add(args, forkoff);
563 return 0;
564 }
565
566
567 /*========================================================================
568 * External routines when attribute list is one block
569 *========================================================================*/
570
571 /*
572 * Add a name to the leaf attribute list structure
573 *
574 * This leaf block cannot have a "remote" value, we only call this routine
575 * if bmap_one_block() says there is only one block (ie: no remote blks).
576 */
577 STATIC int
578 xfs_attr_leaf_addname(
579 struct xfs_da_args *args)
580 {
581 struct xfs_inode *dp;
582 struct xfs_buf *bp;
583 int retval, error, forkoff;
584
585 trace_xfs_attr_leaf_addname(args);
586
587 /*
588 * Read the (only) block in the attribute list in.
589 */
590 dp = args->dp;
591 args->blkno = 0;
592 error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
593 if (error)
594 return error;
595
596 /*
597 * Look up the given attribute in the leaf block. Figure out if
598 * the given flags produce an error or call for an atomic rename.
599 */
600 retval = xfs_attr3_leaf_lookup_int(bp, args);
601 if ((args->flags & ATTR_REPLACE) && (retval == -ENOATTR)) {
602 xfs_trans_brelse(args->trans, bp);
603 return retval;
604 } else if (retval == -EEXIST) {
605 if (args->flags & ATTR_CREATE) { /* pure create op */
606 xfs_trans_brelse(args->trans, bp);
607 return retval;
608 }
609
610 trace_xfs_attr_leaf_replace(args);
611
612 /* save the attribute state for later removal*/
613 args->op_flags |= XFS_DA_OP_RENAME; /* an atomic rename */
614 args->blkno2 = args->blkno; /* set 2nd entry info*/
615 args->index2 = args->index;
616 args->rmtblkno2 = args->rmtblkno;
617 args->rmtblkcnt2 = args->rmtblkcnt;
618 args->rmtvaluelen2 = args->rmtvaluelen;
619
620 /*
621 * clear the remote attr state now that it is saved so that the
622 * values reflect the state of the attribute we are about to
623 * add, not the attribute we just found and will remove later.
624 */
625 args->rmtblkno = 0;
626 args->rmtblkcnt = 0;
627 args->rmtvaluelen = 0;
628 }
629
630 /*
631 * Add the attribute to the leaf block, transitioning to a Btree
632 * if required.
633 */
634 retval = xfs_attr3_leaf_add(bp, args);
635 if (retval == -ENOSPC) {
636 /*
637 * Promote the attribute list to the Btree format, then
638 * Commit that transaction so that the node_addname() call
639 * can manage its own transactions.
640 */
641 error = xfs_attr3_leaf_to_node(args);
642 if (error)
643 return error;
644 error = xfs_defer_finish(&args->trans);
645 if (error)
646 return error;
647
648 /*
649 * Commit the current trans (including the inode) and start
650 * a new one.
651 */
652 error = xfs_trans_roll_inode(&args->trans, dp);
653 if (error)
654 return error;
655
656 /*
657 * Fob the whole rest of the problem off on the Btree code.
658 */
659 error = xfs_attr_node_addname(args);
660 return error;
661 }
662
663 /*
664 * Commit the transaction that added the attr name so that
665 * later routines can manage their own transactions.
666 */
667 error = xfs_trans_roll_inode(&args->trans, dp);
668 if (error)
669 return error;
670
671 /*
672 * If there was an out-of-line value, allocate the blocks we
673 * identified for its storage and copy the value. This is done
674 * after we create the attribute so that we don't overflow the
675 * maximum size of a transaction and/or hit a deadlock.
676 */
677 if (args->rmtblkno > 0) {
678 error = xfs_attr_rmtval_set(args);
679 if (error)
680 return error;
681 }
682
683 /*
684 * If this is an atomic rename operation, we must "flip" the
685 * incomplete flags on the "new" and "old" attribute/value pairs
686 * so that one disappears and one appears atomically. Then we
687 * must remove the "old" attribute/value pair.
688 */
689 if (args->op_flags & XFS_DA_OP_RENAME) {
690 /*
691 * In a separate transaction, set the incomplete flag on the
692 * "old" attr and clear the incomplete flag on the "new" attr.
693 */
694 error = xfs_attr3_leaf_flipflags(args);
695 if (error)
696 return error;
697
698 /*
699 * Dismantle the "old" attribute/value pair by removing
700 * a "remote" value (if it exists).
701 */
702 args->index = args->index2;
703 args->blkno = args->blkno2;
704 args->rmtblkno = args->rmtblkno2;
705 args->rmtblkcnt = args->rmtblkcnt2;
706 args->rmtvaluelen = args->rmtvaluelen2;
707 if (args->rmtblkno) {
708 error = xfs_attr_rmtval_remove(args);
709 if (error)
710 return error;
711 }
712
713 /*
714 * Read in the block containing the "old" attr, then
715 * remove the "old" attr from that block (neat, huh!)
716 */
717 error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno,
718 -1, &bp);
719 if (error)
720 return error;
721
722 xfs_attr3_leaf_remove(bp, args);
723
724 /*
725 * If the result is small enough, shrink it all into the inode.
726 */
727 if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
728 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
729 /* bp is gone due to xfs_da_shrink_inode */
730 if (error)
731 return error;
732 error = xfs_defer_finish(&args->trans);
733 if (error)
734 return error;
735 }
736
737 /*
738 * Commit the remove and start the next trans in series.
739 */
740 error = xfs_trans_roll_inode(&args->trans, dp);
741
742 } else if (args->rmtblkno > 0) {
743 /*
744 * Added a "remote" value, just clear the incomplete flag.
745 */
746 error = xfs_attr3_leaf_clearflag(args);
747 }
748 return error;
749 }
750
751 /*
752 * Remove a name from the leaf attribute list structure
753 *
754 * This leaf block cannot have a "remote" value, we only call this routine
755 * if bmap_one_block() says there is only one block (ie: no remote blks).
756 */
757 STATIC int
758 xfs_attr_leaf_removename(
759 struct xfs_da_args *args)
760 {
761 struct xfs_inode *dp;
762 struct xfs_buf *bp;
763 int error, forkoff;
764
765 trace_xfs_attr_leaf_removename(args);
766
767 /*
768 * Remove the attribute.
769 */
770 dp = args->dp;
771 args->blkno = 0;
772 error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
773 if (error)
774 return error;
775
776 error = xfs_attr3_leaf_lookup_int(bp, args);
777 if (error == -ENOATTR) {
778 xfs_trans_brelse(args->trans, bp);
779 return error;
780 }
781
782 xfs_attr3_leaf_remove(bp, args);
783
784 /*
785 * If the result is small enough, shrink it all into the inode.
786 */
787 if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
788 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
789 /* bp is gone due to xfs_da_shrink_inode */
790 if (error)
791 return error;
792 error = xfs_defer_finish(&args->trans);
793 if (error)
794 return error;
795 }
796 return 0;
797 }
798
799 /*
800 * Look up a name in a leaf attribute list structure.
801 *
802 * This leaf block cannot have a "remote" value, we only call this routine
803 * if bmap_one_block() says there is only one block (ie: no remote blks).
804 *
805 * Returns 0 on successful retrieval, otherwise an error.
806 */
807 STATIC int
808 xfs_attr_leaf_get(xfs_da_args_t *args)
809 {
810 struct xfs_buf *bp;
811 int error;
812
813 trace_xfs_attr_leaf_get(args);
814
815 args->blkno = 0;
816 error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
817 if (error)
818 return error;
819
820 error = xfs_attr3_leaf_lookup_int(bp, args);
821 if (error != -EEXIST) {
822 xfs_trans_brelse(args->trans, bp);
823 return error;
824 }
825 error = xfs_attr3_leaf_getvalue(bp, args);
826 xfs_trans_brelse(args->trans, bp);
827 return error;
828 }
829
830 /*========================================================================
831 * External routines when attribute list size > geo->blksize
832 *========================================================================*/
833
834 /*
835 * Add a name to a Btree-format attribute list.
836 *
837 * This will involve walking down the Btree, and may involve splitting
838 * leaf nodes and even splitting intermediate nodes up to and including
839 * the root node (a special case of an intermediate node).
840 *
841 * "Remote" attribute values confuse the issue and atomic rename operations
842 * add a whole extra layer of confusion on top of that.
843 */
844 STATIC int
845 xfs_attr_node_addname(
846 struct xfs_da_args *args)
847 {
848 struct xfs_da_state *state;
849 struct xfs_da_state_blk *blk;
850 struct xfs_inode *dp;
851 struct xfs_mount *mp;
852 int retval, error;
853
854 trace_xfs_attr_node_addname(args);
855
856 /*
857 * Fill in bucket of arguments/results/context to carry around.
858 */
859 dp = args->dp;
860 mp = dp->i_mount;
861 restart:
862 state = xfs_da_state_alloc();
863 state->args = args;
864 state->mp = mp;
865
866 /*
867 * Search to see if name already exists, and get back a pointer
868 * to where it should go.
869 */
870 error = xfs_da3_node_lookup_int(state, &retval);
871 if (error)
872 goto out;
873 blk = &state->path.blk[ state->path.active-1 ];
874 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
875 if ((args->flags & ATTR_REPLACE) && (retval == -ENOATTR)) {
876 goto out;
877 } else if (retval == -EEXIST) {
878 if (args->flags & ATTR_CREATE)
879 goto out;
880
881 trace_xfs_attr_node_replace(args);
882
883 /* save the attribute state for later removal*/
884 args->op_flags |= XFS_DA_OP_RENAME; /* atomic rename op */
885 args->blkno2 = args->blkno; /* set 2nd entry info*/
886 args->index2 = args->index;
887 args->rmtblkno2 = args->rmtblkno;
888 args->rmtblkcnt2 = args->rmtblkcnt;
889 args->rmtvaluelen2 = args->rmtvaluelen;
890
891 /*
892 * clear the remote attr state now that it is saved so that the
893 * values reflect the state of the attribute we are about to
894 * add, not the attribute we just found and will remove later.
895 */
896 args->rmtblkno = 0;
897 args->rmtblkcnt = 0;
898 args->rmtvaluelen = 0;
899 }
900
901 retval = xfs_attr3_leaf_add(blk->bp, state->args);
902 if (retval == -ENOSPC) {
903 if (state->path.active == 1) {
904 /*
905 * Its really a single leaf node, but it had
906 * out-of-line values so it looked like it *might*
907 * have been a b-tree.
908 */
909 xfs_da_state_free(state);
910 state = NULL;
911 error = xfs_attr3_leaf_to_node(args);
912 if (error)
913 goto out;
914 error = xfs_defer_finish(&args->trans);
915 if (error)
916 goto out;
917
918 /*
919 * Commit the node conversion and start the next
920 * trans in the chain.
921 */
922 error = xfs_trans_roll_inode(&args->trans, dp);
923 if (error)
924 goto out;
925
926 goto restart;
927 }
928
929 /*
930 * Split as many Btree elements as required.
931 * This code tracks the new and old attr's location
932 * in the index/blkno/rmtblkno/rmtblkcnt fields and
933 * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
934 */
935 error = xfs_da3_split(state);
936 if (error)
937 goto out;
938 error = xfs_defer_finish(&args->trans);
939 if (error)
940 goto out;
941 } else {
942 /*
943 * Addition succeeded, update Btree hashvals.
944 */
945 xfs_da3_fixhashpath(state, &state->path);
946 }
947
948 /*
949 * Kill the state structure, we're done with it and need to
950 * allow the buffers to come back later.
951 */
952 xfs_da_state_free(state);
953 state = NULL;
954
955 /*
956 * Commit the leaf addition or btree split and start the next
957 * trans in the chain.
958 */
959 error = xfs_trans_roll_inode(&args->trans, dp);
960 if (error)
961 goto out;
962
963 /*
964 * If there was an out-of-line value, allocate the blocks we
965 * identified for its storage and copy the value. This is done
966 * after we create the attribute so that we don't overflow the
967 * maximum size of a transaction and/or hit a deadlock.
968 */
969 if (args->rmtblkno > 0) {
970 error = xfs_attr_rmtval_set(args);
971 if (error)
972 return error;
973 }
974
975 /*
976 * If this is an atomic rename operation, we must "flip" the
977 * incomplete flags on the "new" and "old" attribute/value pairs
978 * so that one disappears and one appears atomically. Then we
979 * must remove the "old" attribute/value pair.
980 */
981 if (args->op_flags & XFS_DA_OP_RENAME) {
982 /*
983 * In a separate transaction, set the incomplete flag on the
984 * "old" attr and clear the incomplete flag on the "new" attr.
985 */
986 error = xfs_attr3_leaf_flipflags(args);
987 if (error)
988 goto out;
989
990 /*
991 * Dismantle the "old" attribute/value pair by removing
992 * a "remote" value (if it exists).
993 */
994 args->index = args->index2;
995 args->blkno = args->blkno2;
996 args->rmtblkno = args->rmtblkno2;
997 args->rmtblkcnt = args->rmtblkcnt2;
998 args->rmtvaluelen = args->rmtvaluelen2;
999 if (args->rmtblkno) {
1000 error = xfs_attr_rmtval_remove(args);
1001 if (error)
1002 return error;
1003 }
1004
1005 /*
1006 * Re-find the "old" attribute entry after any split ops.
1007 * The INCOMPLETE flag means that we will find the "old"
1008 * attr, not the "new" one.
1009 */
1010 args->flags |= XFS_ATTR_INCOMPLETE;
1011 state = xfs_da_state_alloc();
1012 state->args = args;
1013 state->mp = mp;
1014 state->inleaf = 0;
1015 error = xfs_da3_node_lookup_int(state, &retval);
1016 if (error)
1017 goto out;
1018
1019 /*
1020 * Remove the name and update the hashvals in the tree.
1021 */
1022 blk = &state->path.blk[ state->path.active-1 ];
1023 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1024 error = xfs_attr3_leaf_remove(blk->bp, args);
1025 xfs_da3_fixhashpath(state, &state->path);
1026
1027 /*
1028 * Check to see if the tree needs to be collapsed.
1029 */
1030 if (retval && (state->path.active > 1)) {
1031 error = xfs_da3_join(state);
1032 if (error)
1033 goto out;
1034 error = xfs_defer_finish(&args->trans);
1035 if (error)
1036 goto out;
1037 }
1038
1039 /*
1040 * Commit and start the next trans in the chain.
1041 */
1042 error = xfs_trans_roll_inode(&args->trans, dp);
1043 if (error)
1044 goto out;
1045
1046 } else if (args->rmtblkno > 0) {
1047 /*
1048 * Added a "remote" value, just clear the incomplete flag.
1049 */
1050 error = xfs_attr3_leaf_clearflag(args);
1051 if (error)
1052 goto out;
1053 }
1054 retval = error = 0;
1055
1056 out:
1057 if (state)
1058 xfs_da_state_free(state);
1059 if (error)
1060 return error;
1061 return retval;
1062 }
1063
1064 /*
1065 * Remove a name from a B-tree attribute list.
1066 *
1067 * This will involve walking down the Btree, and may involve joining
1068 * leaf nodes and even joining intermediate nodes up to and including
1069 * the root node (a special case of an intermediate node).
1070 */
1071 STATIC int
1072 xfs_attr_node_removename(
1073 struct xfs_da_args *args)
1074 {
1075 struct xfs_da_state *state;
1076 struct xfs_da_state_blk *blk;
1077 struct xfs_inode *dp;
1078 struct xfs_buf *bp;
1079 int retval, error, forkoff;
1080
1081 trace_xfs_attr_node_removename(args);
1082
1083 /*
1084 * Tie a string around our finger to remind us where we are.
1085 */
1086 dp = args->dp;
1087 state = xfs_da_state_alloc();
1088 state->args = args;
1089 state->mp = dp->i_mount;
1090
1091 /*
1092 * Search to see if name exists, and get back a pointer to it.
1093 */
1094 error = xfs_da3_node_lookup_int(state, &retval);
1095 if (error || (retval != -EEXIST)) {
1096 if (error == 0)
1097 error = retval;
1098 goto out;
1099 }
1100
1101 /*
1102 * If there is an out-of-line value, de-allocate the blocks.
1103 * This is done before we remove the attribute so that we don't
1104 * overflow the maximum size of a transaction and/or hit a deadlock.
1105 */
1106 blk = &state->path.blk[ state->path.active-1 ];
1107 ASSERT(blk->bp != NULL);
1108 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1109 if (args->rmtblkno > 0) {
1110 /*
1111 * Fill in disk block numbers in the state structure
1112 * so that we can get the buffers back after we commit
1113 * several transactions in the following calls.
1114 */
1115 error = xfs_attr_fillstate(state);
1116 if (error)
1117 goto out;
1118
1119 /*
1120 * Mark the attribute as INCOMPLETE, then bunmapi() the
1121 * remote value.
1122 */
1123 error = xfs_attr3_leaf_setflag(args);
1124 if (error)
1125 goto out;
1126 error = xfs_attr_rmtval_remove(args);
1127 if (error)
1128 goto out;
1129
1130 /*
1131 * Refill the state structure with buffers, the prior calls
1132 * released our buffers.
1133 */
1134 error = xfs_attr_refillstate(state);
1135 if (error)
1136 goto out;
1137 }
1138
1139 /*
1140 * Remove the name and update the hashvals in the tree.
1141 */
1142 blk = &state->path.blk[ state->path.active-1 ];
1143 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1144 retval = xfs_attr3_leaf_remove(blk->bp, args);
1145 xfs_da3_fixhashpath(state, &state->path);
1146
1147 /*
1148 * Check to see if the tree needs to be collapsed.
1149 */
1150 if (retval && (state->path.active > 1)) {
1151 error = xfs_da3_join(state);
1152 if (error)
1153 goto out;
1154 error = xfs_defer_finish(&args->trans);
1155 if (error)
1156 goto out;
1157 /*
1158 * Commit the Btree join operation and start a new trans.
1159 */
1160 error = xfs_trans_roll_inode(&args->trans, dp);
1161 if (error)
1162 goto out;
1163 }
1164
1165 /*
1166 * If the result is small enough, push it all into the inode.
1167 */
1168 if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
1169 /*
1170 * Have to get rid of the copy of this dabuf in the state.
1171 */
1172 ASSERT(state->path.active == 1);
1173 ASSERT(state->path.blk[0].bp);
1174 state->path.blk[0].bp = NULL;
1175
1176 error = xfs_attr3_leaf_read(args->trans, args->dp, 0, -1, &bp);
1177 if (error)
1178 goto out;
1179
1180 if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
1181 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
1182 /* bp is gone due to xfs_da_shrink_inode */
1183 if (error)
1184 goto out;
1185 error = xfs_defer_finish(&args->trans);
1186 if (error)
1187 goto out;
1188 } else
1189 xfs_trans_brelse(args->trans, bp);
1190 }
1191 error = 0;
1192
1193 out:
1194 xfs_da_state_free(state);
1195 return error;
1196 }
1197
1198 /*
1199 * Fill in the disk block numbers in the state structure for the buffers
1200 * that are attached to the state structure.
1201 * This is done so that we can quickly reattach ourselves to those buffers
1202 * after some set of transaction commits have released these buffers.
1203 */
1204 STATIC int
1205 xfs_attr_fillstate(xfs_da_state_t *state)
1206 {
1207 xfs_da_state_path_t *path;
1208 xfs_da_state_blk_t *blk;
1209 int level;
1210
1211 trace_xfs_attr_fillstate(state->args);
1212
1213 /*
1214 * Roll down the "path" in the state structure, storing the on-disk
1215 * block number for those buffers in the "path".
1216 */
1217 path = &state->path;
1218 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1219 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
1220 if (blk->bp) {
1221 blk->disk_blkno = XFS_BUF_ADDR(blk->bp);
1222 blk->bp = NULL;
1223 } else {
1224 blk->disk_blkno = 0;
1225 }
1226 }
1227
1228 /*
1229 * Roll down the "altpath" in the state structure, storing the on-disk
1230 * block number for those buffers in the "altpath".
1231 */
1232 path = &state->altpath;
1233 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1234 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
1235 if (blk->bp) {
1236 blk->disk_blkno = XFS_BUF_ADDR(blk->bp);
1237 blk->bp = NULL;
1238 } else {
1239 blk->disk_blkno = 0;
1240 }
1241 }
1242
1243 return 0;
1244 }
1245
1246 /*
1247 * Reattach the buffers to the state structure based on the disk block
1248 * numbers stored in the state structure.
1249 * This is done after some set of transaction commits have released those
1250 * buffers from our grip.
1251 */
1252 STATIC int
1253 xfs_attr_refillstate(xfs_da_state_t *state)
1254 {
1255 xfs_da_state_path_t *path;
1256 xfs_da_state_blk_t *blk;
1257 int level, error;
1258
1259 trace_xfs_attr_refillstate(state->args);
1260
1261 /*
1262 * Roll down the "path" in the state structure, storing the on-disk
1263 * block number for those buffers in the "path".
1264 */
1265 path = &state->path;
1266 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1267 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
1268 if (blk->disk_blkno) {
1269 error = xfs_da3_node_read(state->args->trans,
1270 state->args->dp,
1271 blk->blkno, blk->disk_blkno,
1272 &blk->bp, XFS_ATTR_FORK);
1273 if (error)
1274 return error;
1275 } else {
1276 blk->bp = NULL;
1277 }
1278 }
1279
1280 /*
1281 * Roll down the "altpath" in the state structure, storing the on-disk
1282 * block number for those buffers in the "altpath".
1283 */
1284 path = &state->altpath;
1285 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1286 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
1287 if (blk->disk_blkno) {
1288 error = xfs_da3_node_read(state->args->trans,
1289 state->args->dp,
1290 blk->blkno, blk->disk_blkno,
1291 &blk->bp, XFS_ATTR_FORK);
1292 if (error)
1293 return error;
1294 } else {
1295 blk->bp = NULL;
1296 }
1297 }
1298
1299 return 0;
1300 }
1301
1302 /*
1303 * Retrieve the attribute data from a node attribute list.
1304 *
1305 * This routine gets called for any attribute fork that has more than one
1306 * block, ie: both true Btree attr lists and for single-leaf-blocks with
1307 * "remote" values taking up more blocks.
1308 *
1309 * Returns 0 on successful retrieval, otherwise an error.
1310 */
1311 STATIC int
1312 xfs_attr_node_get(xfs_da_args_t *args)
1313 {
1314 xfs_da_state_t *state;
1315 xfs_da_state_blk_t *blk;
1316 int error, retval;
1317 int i;
1318
1319 trace_xfs_attr_node_get(args);
1320
1321 state = xfs_da_state_alloc();
1322 state->args = args;
1323 state->mp = args->dp->i_mount;
1324
1325 /*
1326 * Search to see if name exists, and get back a pointer to it.
1327 */
1328 error = xfs_da3_node_lookup_int(state, &retval);
1329 if (error) {
1330 retval = error;
1331 goto out_release;
1332 }
1333 if (retval != -EEXIST)
1334 goto out_release;
1335
1336 /*
1337 * Get the value, local or "remote"
1338 */
1339 blk = &state->path.blk[state->path.active - 1];
1340 retval = xfs_attr3_leaf_getvalue(blk->bp, args);
1341
1342 /*
1343 * If not in a transaction, we have to release all the buffers.
1344 */
1345 out_release:
1346 for (i = 0; i < state->path.active; i++) {
1347 xfs_trans_brelse(args->trans, state->path.blk[i].bp);
1348 state->path.blk[i].bp = NULL;
1349 }
1350
1351 xfs_da_state_free(state);
1352 return retval;
1353 }
1354
1355 /* Returns true if the attribute entry name is valid. */
1356 bool
1357 xfs_attr_namecheck(
1358 const void *name,
1359 size_t length)
1360 {
1361 /*
1362 * MAXNAMELEN includes the trailing null, but (name/length) leave it
1363 * out, so use >= for the length check.
1364 */
1365 if (length >= MAXNAMELEN)
1366 return false;
1367
1368 /* There shouldn't be any nulls here */
1369 return !memchr(name, 0, length);
1370 }