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Merge branch 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[deliverable/linux.git] / fs / xfs / libxfs / xfs_attr.c
1 /*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_bit.h"
25 #include "xfs_mount.h"
26 #include "xfs_da_format.h"
27 #include "xfs_da_btree.h"
28 #include "xfs_attr_sf.h"
29 #include "xfs_inode.h"
30 #include "xfs_alloc.h"
31 #include "xfs_trans.h"
32 #include "xfs_inode_item.h"
33 #include "xfs_bmap.h"
34 #include "xfs_bmap_util.h"
35 #include "xfs_bmap_btree.h"
36 #include "xfs_attr.h"
37 #include "xfs_attr_leaf.h"
38 #include "xfs_attr_remote.h"
39 #include "xfs_error.h"
40 #include "xfs_quota.h"
41 #include "xfs_trans_space.h"
42 #include "xfs_trace.h"
43
44 /*
45 * xfs_attr.c
46 *
47 * Provide the external interfaces to manage attribute lists.
48 */
49
50 /*========================================================================
51 * Function prototypes for the kernel.
52 *========================================================================*/
53
54 /*
55 * Internal routines when attribute list fits inside the inode.
56 */
57 STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);
58
59 /*
60 * Internal routines when attribute list is one block.
61 */
62 STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
63 STATIC int xfs_attr_leaf_addname(xfs_da_args_t *args);
64 STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
65
66 /*
67 * Internal routines when attribute list is more than one block.
68 */
69 STATIC int xfs_attr_node_get(xfs_da_args_t *args);
70 STATIC int xfs_attr_node_addname(xfs_da_args_t *args);
71 STATIC int xfs_attr_node_removename(xfs_da_args_t *args);
72 STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
73 STATIC int xfs_attr_refillstate(xfs_da_state_t *state);
74
75
76 STATIC int
77 xfs_attr_args_init(
78 struct xfs_da_args *args,
79 struct xfs_inode *dp,
80 const unsigned char *name,
81 int flags)
82 {
83
84 if (!name)
85 return -EINVAL;
86
87 memset(args, 0, sizeof(*args));
88 args->geo = dp->i_mount->m_attr_geo;
89 args->whichfork = XFS_ATTR_FORK;
90 args->dp = dp;
91 args->flags = flags;
92 args->name = name;
93 args->namelen = strlen((const char *)name);
94 if (args->namelen >= MAXNAMELEN)
95 return -EFAULT; /* match IRIX behaviour */
96
97 args->hashval = xfs_da_hashname(args->name, args->namelen);
98 return 0;
99 }
100
101 int
102 xfs_inode_hasattr(
103 struct xfs_inode *ip)
104 {
105 if (!XFS_IFORK_Q(ip) ||
106 (ip->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
107 ip->i_d.di_anextents == 0))
108 return 0;
109 return 1;
110 }
111
112 /*========================================================================
113 * Overall external interface routines.
114 *========================================================================*/
115
116 int
117 xfs_attr_get(
118 struct xfs_inode *ip,
119 const unsigned char *name,
120 unsigned char *value,
121 int *valuelenp,
122 int flags)
123 {
124 struct xfs_da_args args;
125 uint lock_mode;
126 int error;
127
128 XFS_STATS_INC(ip->i_mount, xs_attr_get);
129
130 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
131 return -EIO;
132
133 if (!xfs_inode_hasattr(ip))
134 return -ENOATTR;
135
136 error = xfs_attr_args_init(&args, ip, name, flags);
137 if (error)
138 return error;
139
140 args.value = value;
141 args.valuelen = *valuelenp;
142 /* Entirely possible to look up a name which doesn't exist */
143 args.op_flags = XFS_DA_OP_OKNOENT;
144
145 lock_mode = xfs_ilock_attr_map_shared(ip);
146 if (!xfs_inode_hasattr(ip))
147 error = -ENOATTR;
148 else if (ip->i_d.di_aformat == XFS_DINODE_FMT_LOCAL)
149 error = xfs_attr_shortform_getvalue(&args);
150 else if (xfs_bmap_one_block(ip, XFS_ATTR_FORK))
151 error = xfs_attr_leaf_get(&args);
152 else
153 error = xfs_attr_node_get(&args);
154 xfs_iunlock(ip, lock_mode);
155
156 *valuelenp = args.valuelen;
157 return error == -EEXIST ? 0 : error;
158 }
159
160 /*
161 * Calculate how many blocks we need for the new attribute,
162 */
163 STATIC int
164 xfs_attr_calc_size(
165 struct xfs_da_args *args,
166 int *local)
167 {
168 struct xfs_mount *mp = args->dp->i_mount;
169 int size;
170 int nblks;
171
172 /*
173 * Determine space new attribute will use, and if it would be
174 * "local" or "remote" (note: local != inline).
175 */
176 size = xfs_attr_leaf_newentsize(args, local);
177 nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
178 if (*local) {
179 if (size > (args->geo->blksize / 2)) {
180 /* Double split possible */
181 nblks *= 2;
182 }
183 } else {
184 /*
185 * Out of line attribute, cannot double split, but
186 * make room for the attribute value itself.
187 */
188 uint dblocks = xfs_attr3_rmt_blocks(mp, args->valuelen);
189 nblks += dblocks;
190 nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
191 }
192
193 return nblks;
194 }
195
196 int
197 xfs_attr_set(
198 struct xfs_inode *dp,
199 const unsigned char *name,
200 unsigned char *value,
201 int valuelen,
202 int flags)
203 {
204 struct xfs_mount *mp = dp->i_mount;
205 struct xfs_da_args args;
206 struct xfs_bmap_free flist;
207 struct xfs_trans_res tres;
208 xfs_fsblock_t firstblock;
209 int rsvd = (flags & ATTR_ROOT) != 0;
210 int error, err2, local;
211
212 XFS_STATS_INC(mp, xs_attr_set);
213
214 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
215 return -EIO;
216
217 error = xfs_attr_args_init(&args, dp, name, flags);
218 if (error)
219 return error;
220
221 args.value = value;
222 args.valuelen = valuelen;
223 args.firstblock = &firstblock;
224 args.flist = &flist;
225 args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
226 args.total = xfs_attr_calc_size(&args, &local);
227
228 error = xfs_qm_dqattach(dp, 0);
229 if (error)
230 return error;
231
232 /*
233 * If the inode doesn't have an attribute fork, add one.
234 * (inode must not be locked when we call this routine)
235 */
236 if (XFS_IFORK_Q(dp) == 0) {
237 int sf_size = sizeof(xfs_attr_sf_hdr_t) +
238 XFS_ATTR_SF_ENTSIZE_BYNAME(args.namelen, valuelen);
239
240 error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
241 if (error)
242 return error;
243 }
244
245 tres.tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
246 M_RES(mp)->tr_attrsetrt.tr_logres * args.total;
247 tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;
248 tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
249
250 /*
251 * Root fork attributes can use reserved data blocks for this
252 * operation if necessary
253 */
254 error = xfs_trans_alloc(mp, &tres, args.total, 0,
255 rsvd ? XFS_TRANS_RESERVE : 0, &args.trans);
256 if (error)
257 return error;
258
259 xfs_ilock(dp, XFS_ILOCK_EXCL);
260 error = xfs_trans_reserve_quota_nblks(args.trans, dp, args.total, 0,
261 rsvd ? XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES :
262 XFS_QMOPT_RES_REGBLKS);
263 if (error) {
264 xfs_iunlock(dp, XFS_ILOCK_EXCL);
265 xfs_trans_cancel(args.trans);
266 return error;
267 }
268
269 xfs_trans_ijoin(args.trans, dp, 0);
270
271 /*
272 * If the attribute list is non-existent or a shortform list,
273 * upgrade it to a single-leaf-block attribute list.
274 */
275 if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL ||
276 (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
277 dp->i_d.di_anextents == 0)) {
278
279 /*
280 * Build initial attribute list (if required).
281 */
282 if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS)
283 xfs_attr_shortform_create(&args);
284
285 /*
286 * Try to add the attr to the attribute list in
287 * the inode.
288 */
289 error = xfs_attr_shortform_addname(&args);
290 if (error != -ENOSPC) {
291 /*
292 * Commit the shortform mods, and we're done.
293 * NOTE: this is also the error path (EEXIST, etc).
294 */
295 ASSERT(args.trans != NULL);
296
297 /*
298 * If this is a synchronous mount, make sure that
299 * the transaction goes to disk before returning
300 * to the user.
301 */
302 if (mp->m_flags & XFS_MOUNT_WSYNC)
303 xfs_trans_set_sync(args.trans);
304
305 if (!error && (flags & ATTR_KERNOTIME) == 0) {
306 xfs_trans_ichgtime(args.trans, dp,
307 XFS_ICHGTIME_CHG);
308 }
309 err2 = xfs_trans_commit(args.trans);
310 xfs_iunlock(dp, XFS_ILOCK_EXCL);
311
312 return error ? error : err2;
313 }
314
315 /*
316 * It won't fit in the shortform, transform to a leaf block.
317 * GROT: another possible req'mt for a double-split btree op.
318 */
319 xfs_bmap_init(args.flist, args.firstblock);
320 error = xfs_attr_shortform_to_leaf(&args);
321 if (!error)
322 error = xfs_bmap_finish(&args.trans, args.flist, dp);
323 if (error) {
324 args.trans = NULL;
325 xfs_bmap_cancel(&flist);
326 goto out;
327 }
328
329 /*
330 * Commit the leaf transformation. We'll need another (linked)
331 * transaction to add the new attribute to the leaf.
332 */
333
334 error = xfs_trans_roll(&args.trans, dp);
335 if (error)
336 goto out;
337
338 }
339
340 if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
341 error = xfs_attr_leaf_addname(&args);
342 else
343 error = xfs_attr_node_addname(&args);
344 if (error)
345 goto out;
346
347 /*
348 * If this is a synchronous mount, make sure that the
349 * transaction goes to disk before returning to the user.
350 */
351 if (mp->m_flags & XFS_MOUNT_WSYNC)
352 xfs_trans_set_sync(args.trans);
353
354 if ((flags & ATTR_KERNOTIME) == 0)
355 xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);
356
357 /*
358 * Commit the last in the sequence of transactions.
359 */
360 xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
361 error = xfs_trans_commit(args.trans);
362 xfs_iunlock(dp, XFS_ILOCK_EXCL);
363
364 return error;
365
366 out:
367 if (args.trans)
368 xfs_trans_cancel(args.trans);
369 xfs_iunlock(dp, XFS_ILOCK_EXCL);
370 return error;
371 }
372
373 /*
374 * Generic handler routine to remove a name from an attribute list.
375 * Transitions attribute list from Btree to shortform as necessary.
376 */
377 int
378 xfs_attr_remove(
379 struct xfs_inode *dp,
380 const unsigned char *name,
381 int flags)
382 {
383 struct xfs_mount *mp = dp->i_mount;
384 struct xfs_da_args args;
385 struct xfs_bmap_free flist;
386 xfs_fsblock_t firstblock;
387 int error;
388
389 XFS_STATS_INC(mp, xs_attr_remove);
390
391 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
392 return -EIO;
393
394 if (!xfs_inode_hasattr(dp))
395 return -ENOATTR;
396
397 error = xfs_attr_args_init(&args, dp, name, flags);
398 if (error)
399 return error;
400
401 args.firstblock = &firstblock;
402 args.flist = &flist;
403
404 /*
405 * we have no control over the attribute names that userspace passes us
406 * to remove, so we have to allow the name lookup prior to attribute
407 * removal to fail.
408 */
409 args.op_flags = XFS_DA_OP_OKNOENT;
410
411 error = xfs_qm_dqattach(dp, 0);
412 if (error)
413 return error;
414
415 /*
416 * Root fork attributes can use reserved data blocks for this
417 * operation if necessary
418 */
419 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_attrrm,
420 XFS_ATTRRM_SPACE_RES(mp), 0,
421 (flags & ATTR_ROOT) ? XFS_TRANS_RESERVE : 0,
422 &args.trans);
423 if (error)
424 return error;
425
426 xfs_ilock(dp, XFS_ILOCK_EXCL);
427 /*
428 * No need to make quota reservations here. We expect to release some
429 * blocks not allocate in the common case.
430 */
431 xfs_trans_ijoin(args.trans, dp, 0);
432
433 if (!xfs_inode_hasattr(dp)) {
434 error = -ENOATTR;
435 } else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
436 ASSERT(dp->i_afp->if_flags & XFS_IFINLINE);
437 error = xfs_attr_shortform_remove(&args);
438 } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
439 error = xfs_attr_leaf_removename(&args);
440 } else {
441 error = xfs_attr_node_removename(&args);
442 }
443
444 if (error)
445 goto out;
446
447 /*
448 * If this is a synchronous mount, make sure that the
449 * transaction goes to disk before returning to the user.
450 */
451 if (mp->m_flags & XFS_MOUNT_WSYNC)
452 xfs_trans_set_sync(args.trans);
453
454 if ((flags & ATTR_KERNOTIME) == 0)
455 xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);
456
457 /*
458 * Commit the last in the sequence of transactions.
459 */
460 xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
461 error = xfs_trans_commit(args.trans);
462 xfs_iunlock(dp, XFS_ILOCK_EXCL);
463
464 return error;
465
466 out:
467 if (args.trans)
468 xfs_trans_cancel(args.trans);
469 xfs_iunlock(dp, XFS_ILOCK_EXCL);
470 return error;
471 }
472
473 /*========================================================================
474 * External routines when attribute list is inside the inode
475 *========================================================================*/
476
477 /*
478 * Add a name to the shortform attribute list structure
479 * This is the external routine.
480 */
481 STATIC int
482 xfs_attr_shortform_addname(xfs_da_args_t *args)
483 {
484 int newsize, forkoff, retval;
485
486 trace_xfs_attr_sf_addname(args);
487
488 retval = xfs_attr_shortform_lookup(args);
489 if ((args->flags & ATTR_REPLACE) && (retval == -ENOATTR)) {
490 return retval;
491 } else if (retval == -EEXIST) {
492 if (args->flags & ATTR_CREATE)
493 return retval;
494 retval = xfs_attr_shortform_remove(args);
495 ASSERT(retval == 0);
496 }
497
498 if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX ||
499 args->valuelen >= XFS_ATTR_SF_ENTSIZE_MAX)
500 return -ENOSPC;
501
502 newsize = XFS_ATTR_SF_TOTSIZE(args->dp);
503 newsize += XFS_ATTR_SF_ENTSIZE_BYNAME(args->namelen, args->valuelen);
504
505 forkoff = xfs_attr_shortform_bytesfit(args->dp, newsize);
506 if (!forkoff)
507 return -ENOSPC;
508
509 xfs_attr_shortform_add(args, forkoff);
510 return 0;
511 }
512
513
514 /*========================================================================
515 * External routines when attribute list is one block
516 *========================================================================*/
517
518 /*
519 * Add a name to the leaf attribute list structure
520 *
521 * This leaf block cannot have a "remote" value, we only call this routine
522 * if bmap_one_block() says there is only one block (ie: no remote blks).
523 */
524 STATIC int
525 xfs_attr_leaf_addname(xfs_da_args_t *args)
526 {
527 xfs_inode_t *dp;
528 struct xfs_buf *bp;
529 int retval, error, forkoff;
530
531 trace_xfs_attr_leaf_addname(args);
532
533 /*
534 * Read the (only) block in the attribute list in.
535 */
536 dp = args->dp;
537 args->blkno = 0;
538 error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
539 if (error)
540 return error;
541
542 /*
543 * Look up the given attribute in the leaf block. Figure out if
544 * the given flags produce an error or call for an atomic rename.
545 */
546 retval = xfs_attr3_leaf_lookup_int(bp, args);
547 if ((args->flags & ATTR_REPLACE) && (retval == -ENOATTR)) {
548 xfs_trans_brelse(args->trans, bp);
549 return retval;
550 } else if (retval == -EEXIST) {
551 if (args->flags & ATTR_CREATE) { /* pure create op */
552 xfs_trans_brelse(args->trans, bp);
553 return retval;
554 }
555
556 trace_xfs_attr_leaf_replace(args);
557
558 /* save the attribute state for later removal*/
559 args->op_flags |= XFS_DA_OP_RENAME; /* an atomic rename */
560 args->blkno2 = args->blkno; /* set 2nd entry info*/
561 args->index2 = args->index;
562 args->rmtblkno2 = args->rmtblkno;
563 args->rmtblkcnt2 = args->rmtblkcnt;
564 args->rmtvaluelen2 = args->rmtvaluelen;
565
566 /*
567 * clear the remote attr state now that it is saved so that the
568 * values reflect the state of the attribute we are about to
569 * add, not the attribute we just found and will remove later.
570 */
571 args->rmtblkno = 0;
572 args->rmtblkcnt = 0;
573 args->rmtvaluelen = 0;
574 }
575
576 /*
577 * Add the attribute to the leaf block, transitioning to a Btree
578 * if required.
579 */
580 retval = xfs_attr3_leaf_add(bp, args);
581 if (retval == -ENOSPC) {
582 /*
583 * Promote the attribute list to the Btree format, then
584 * Commit that transaction so that the node_addname() call
585 * can manage its own transactions.
586 */
587 xfs_bmap_init(args->flist, args->firstblock);
588 error = xfs_attr3_leaf_to_node(args);
589 if (!error)
590 error = xfs_bmap_finish(&args->trans, args->flist, dp);
591 if (error) {
592 args->trans = NULL;
593 xfs_bmap_cancel(args->flist);
594 return error;
595 }
596
597 /*
598 * Commit the current trans (including the inode) and start
599 * a new one.
600 */
601 error = xfs_trans_roll(&args->trans, dp);
602 if (error)
603 return error;
604
605 /*
606 * Fob the whole rest of the problem off on the Btree code.
607 */
608 error = xfs_attr_node_addname(args);
609 return error;
610 }
611
612 /*
613 * Commit the transaction that added the attr name so that
614 * later routines can manage their own transactions.
615 */
616 error = xfs_trans_roll(&args->trans, dp);
617 if (error)
618 return error;
619
620 /*
621 * If there was an out-of-line value, allocate the blocks we
622 * identified for its storage and copy the value. This is done
623 * after we create the attribute so that we don't overflow the
624 * maximum size of a transaction and/or hit a deadlock.
625 */
626 if (args->rmtblkno > 0) {
627 error = xfs_attr_rmtval_set(args);
628 if (error)
629 return error;
630 }
631
632 /*
633 * If this is an atomic rename operation, we must "flip" the
634 * incomplete flags on the "new" and "old" attribute/value pairs
635 * so that one disappears and one appears atomically. Then we
636 * must remove the "old" attribute/value pair.
637 */
638 if (args->op_flags & XFS_DA_OP_RENAME) {
639 /*
640 * In a separate transaction, set the incomplete flag on the
641 * "old" attr and clear the incomplete flag on the "new" attr.
642 */
643 error = xfs_attr3_leaf_flipflags(args);
644 if (error)
645 return error;
646
647 /*
648 * Dismantle the "old" attribute/value pair by removing
649 * a "remote" value (if it exists).
650 */
651 args->index = args->index2;
652 args->blkno = args->blkno2;
653 args->rmtblkno = args->rmtblkno2;
654 args->rmtblkcnt = args->rmtblkcnt2;
655 args->rmtvaluelen = args->rmtvaluelen2;
656 if (args->rmtblkno) {
657 error = xfs_attr_rmtval_remove(args);
658 if (error)
659 return error;
660 }
661
662 /*
663 * Read in the block containing the "old" attr, then
664 * remove the "old" attr from that block (neat, huh!)
665 */
666 error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno,
667 -1, &bp);
668 if (error)
669 return error;
670
671 xfs_attr3_leaf_remove(bp, args);
672
673 /*
674 * If the result is small enough, shrink it all into the inode.
675 */
676 if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
677 xfs_bmap_init(args->flist, args->firstblock);
678 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
679 /* bp is gone due to xfs_da_shrink_inode */
680 if (!error)
681 error = xfs_bmap_finish(&args->trans,
682 args->flist, dp);
683 if (error) {
684 args->trans = NULL;
685 xfs_bmap_cancel(args->flist);
686 return error;
687 }
688 }
689
690 /*
691 * Commit the remove and start the next trans in series.
692 */
693 error = xfs_trans_roll(&args->trans, dp);
694
695 } else if (args->rmtblkno > 0) {
696 /*
697 * Added a "remote" value, just clear the incomplete flag.
698 */
699 error = xfs_attr3_leaf_clearflag(args);
700 }
701 return error;
702 }
703
704 /*
705 * Remove a name from the leaf attribute list structure
706 *
707 * This leaf block cannot have a "remote" value, we only call this routine
708 * if bmap_one_block() says there is only one block (ie: no remote blks).
709 */
710 STATIC int
711 xfs_attr_leaf_removename(xfs_da_args_t *args)
712 {
713 xfs_inode_t *dp;
714 struct xfs_buf *bp;
715 int error, forkoff;
716
717 trace_xfs_attr_leaf_removename(args);
718
719 /*
720 * Remove the attribute.
721 */
722 dp = args->dp;
723 args->blkno = 0;
724 error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
725 if (error)
726 return error;
727
728 error = xfs_attr3_leaf_lookup_int(bp, args);
729 if (error == -ENOATTR) {
730 xfs_trans_brelse(args->trans, bp);
731 return error;
732 }
733
734 xfs_attr3_leaf_remove(bp, args);
735
736 /*
737 * If the result is small enough, shrink it all into the inode.
738 */
739 if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
740 xfs_bmap_init(args->flist, args->firstblock);
741 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
742 /* bp is gone due to xfs_da_shrink_inode */
743 if (!error)
744 error = xfs_bmap_finish(&args->trans, args->flist, dp);
745 if (error) {
746 args->trans = NULL;
747 xfs_bmap_cancel(args->flist);
748 return error;
749 }
750 }
751 return 0;
752 }
753
754 /*
755 * Look up a name in a leaf attribute list structure.
756 *
757 * This leaf block cannot have a "remote" value, we only call this routine
758 * if bmap_one_block() says there is only one block (ie: no remote blks).
759 */
760 STATIC int
761 xfs_attr_leaf_get(xfs_da_args_t *args)
762 {
763 struct xfs_buf *bp;
764 int error;
765
766 trace_xfs_attr_leaf_get(args);
767
768 args->blkno = 0;
769 error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
770 if (error)
771 return error;
772
773 error = xfs_attr3_leaf_lookup_int(bp, args);
774 if (error != -EEXIST) {
775 xfs_trans_brelse(args->trans, bp);
776 return error;
777 }
778 error = xfs_attr3_leaf_getvalue(bp, args);
779 xfs_trans_brelse(args->trans, bp);
780 if (!error && (args->rmtblkno > 0) && !(args->flags & ATTR_KERNOVAL)) {
781 error = xfs_attr_rmtval_get(args);
782 }
783 return error;
784 }
785
786 /*========================================================================
787 * External routines when attribute list size > geo->blksize
788 *========================================================================*/
789
790 /*
791 * Add a name to a Btree-format attribute list.
792 *
793 * This will involve walking down the Btree, and may involve splitting
794 * leaf nodes and even splitting intermediate nodes up to and including
795 * the root node (a special case of an intermediate node).
796 *
797 * "Remote" attribute values confuse the issue and atomic rename operations
798 * add a whole extra layer of confusion on top of that.
799 */
800 STATIC int
801 xfs_attr_node_addname(xfs_da_args_t *args)
802 {
803 xfs_da_state_t *state;
804 xfs_da_state_blk_t *blk;
805 xfs_inode_t *dp;
806 xfs_mount_t *mp;
807 int retval, error;
808
809 trace_xfs_attr_node_addname(args);
810
811 /*
812 * Fill in bucket of arguments/results/context to carry around.
813 */
814 dp = args->dp;
815 mp = dp->i_mount;
816 restart:
817 state = xfs_da_state_alloc();
818 state->args = args;
819 state->mp = mp;
820
821 /*
822 * Search to see if name already exists, and get back a pointer
823 * to where it should go.
824 */
825 error = xfs_da3_node_lookup_int(state, &retval);
826 if (error)
827 goto out;
828 blk = &state->path.blk[ state->path.active-1 ];
829 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
830 if ((args->flags & ATTR_REPLACE) && (retval == -ENOATTR)) {
831 goto out;
832 } else if (retval == -EEXIST) {
833 if (args->flags & ATTR_CREATE)
834 goto out;
835
836 trace_xfs_attr_node_replace(args);
837
838 /* save the attribute state for later removal*/
839 args->op_flags |= XFS_DA_OP_RENAME; /* atomic rename op */
840 args->blkno2 = args->blkno; /* set 2nd entry info*/
841 args->index2 = args->index;
842 args->rmtblkno2 = args->rmtblkno;
843 args->rmtblkcnt2 = args->rmtblkcnt;
844 args->rmtvaluelen2 = args->rmtvaluelen;
845
846 /*
847 * clear the remote attr state now that it is saved so that the
848 * values reflect the state of the attribute we are about to
849 * add, not the attribute we just found and will remove later.
850 */
851 args->rmtblkno = 0;
852 args->rmtblkcnt = 0;
853 args->rmtvaluelen = 0;
854 }
855
856 retval = xfs_attr3_leaf_add(blk->bp, state->args);
857 if (retval == -ENOSPC) {
858 if (state->path.active == 1) {
859 /*
860 * Its really a single leaf node, but it had
861 * out-of-line values so it looked like it *might*
862 * have been a b-tree.
863 */
864 xfs_da_state_free(state);
865 state = NULL;
866 xfs_bmap_init(args->flist, args->firstblock);
867 error = xfs_attr3_leaf_to_node(args);
868 if (!error)
869 error = xfs_bmap_finish(&args->trans,
870 args->flist, dp);
871 if (error) {
872 args->trans = NULL;
873 xfs_bmap_cancel(args->flist);
874 goto out;
875 }
876
877 /*
878 * Commit the node conversion and start the next
879 * trans in the chain.
880 */
881 error = xfs_trans_roll(&args->trans, dp);
882 if (error)
883 goto out;
884
885 goto restart;
886 }
887
888 /*
889 * Split as many Btree elements as required.
890 * This code tracks the new and old attr's location
891 * in the index/blkno/rmtblkno/rmtblkcnt fields and
892 * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
893 */
894 xfs_bmap_init(args->flist, args->firstblock);
895 error = xfs_da3_split(state);
896 if (!error)
897 error = xfs_bmap_finish(&args->trans, args->flist, dp);
898 if (error) {
899 args->trans = NULL;
900 xfs_bmap_cancel(args->flist);
901 goto out;
902 }
903 } else {
904 /*
905 * Addition succeeded, update Btree hashvals.
906 */
907 xfs_da3_fixhashpath(state, &state->path);
908 }
909
910 /*
911 * Kill the state structure, we're done with it and need to
912 * allow the buffers to come back later.
913 */
914 xfs_da_state_free(state);
915 state = NULL;
916
917 /*
918 * Commit the leaf addition or btree split and start the next
919 * trans in the chain.
920 */
921 error = xfs_trans_roll(&args->trans, dp);
922 if (error)
923 goto out;
924
925 /*
926 * If there was an out-of-line value, allocate the blocks we
927 * identified for its storage and copy the value. This is done
928 * after we create the attribute so that we don't overflow the
929 * maximum size of a transaction and/or hit a deadlock.
930 */
931 if (args->rmtblkno > 0) {
932 error = xfs_attr_rmtval_set(args);
933 if (error)
934 return error;
935 }
936
937 /*
938 * If this is an atomic rename operation, we must "flip" the
939 * incomplete flags on the "new" and "old" attribute/value pairs
940 * so that one disappears and one appears atomically. Then we
941 * must remove the "old" attribute/value pair.
942 */
943 if (args->op_flags & XFS_DA_OP_RENAME) {
944 /*
945 * In a separate transaction, set the incomplete flag on the
946 * "old" attr and clear the incomplete flag on the "new" attr.
947 */
948 error = xfs_attr3_leaf_flipflags(args);
949 if (error)
950 goto out;
951
952 /*
953 * Dismantle the "old" attribute/value pair by removing
954 * a "remote" value (if it exists).
955 */
956 args->index = args->index2;
957 args->blkno = args->blkno2;
958 args->rmtblkno = args->rmtblkno2;
959 args->rmtblkcnt = args->rmtblkcnt2;
960 args->rmtvaluelen = args->rmtvaluelen2;
961 if (args->rmtblkno) {
962 error = xfs_attr_rmtval_remove(args);
963 if (error)
964 return error;
965 }
966
967 /*
968 * Re-find the "old" attribute entry after any split ops.
969 * The INCOMPLETE flag means that we will find the "old"
970 * attr, not the "new" one.
971 */
972 args->flags |= XFS_ATTR_INCOMPLETE;
973 state = xfs_da_state_alloc();
974 state->args = args;
975 state->mp = mp;
976 state->inleaf = 0;
977 error = xfs_da3_node_lookup_int(state, &retval);
978 if (error)
979 goto out;
980
981 /*
982 * Remove the name and update the hashvals in the tree.
983 */
984 blk = &state->path.blk[ state->path.active-1 ];
985 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
986 error = xfs_attr3_leaf_remove(blk->bp, args);
987 xfs_da3_fixhashpath(state, &state->path);
988
989 /*
990 * Check to see if the tree needs to be collapsed.
991 */
992 if (retval && (state->path.active > 1)) {
993 xfs_bmap_init(args->flist, args->firstblock);
994 error = xfs_da3_join(state);
995 if (!error)
996 error = xfs_bmap_finish(&args->trans,
997 args->flist, dp);
998 if (error) {
999 args->trans = NULL;
1000 xfs_bmap_cancel(args->flist);
1001 goto out;
1002 }
1003 }
1004
1005 /*
1006 * Commit and start the next trans in the chain.
1007 */
1008 error = xfs_trans_roll(&args->trans, dp);
1009 if (error)
1010 goto out;
1011
1012 } else if (args->rmtblkno > 0) {
1013 /*
1014 * Added a "remote" value, just clear the incomplete flag.
1015 */
1016 error = xfs_attr3_leaf_clearflag(args);
1017 if (error)
1018 goto out;
1019 }
1020 retval = error = 0;
1021
1022 out:
1023 if (state)
1024 xfs_da_state_free(state);
1025 if (error)
1026 return error;
1027 return retval;
1028 }
1029
1030 /*
1031 * Remove a name from a B-tree attribute list.
1032 *
1033 * This will involve walking down the Btree, and may involve joining
1034 * leaf nodes and even joining intermediate nodes up to and including
1035 * the root node (a special case of an intermediate node).
1036 */
1037 STATIC int
1038 xfs_attr_node_removename(xfs_da_args_t *args)
1039 {
1040 xfs_da_state_t *state;
1041 xfs_da_state_blk_t *blk;
1042 xfs_inode_t *dp;
1043 struct xfs_buf *bp;
1044 int retval, error, forkoff;
1045
1046 trace_xfs_attr_node_removename(args);
1047
1048 /*
1049 * Tie a string around our finger to remind us where we are.
1050 */
1051 dp = args->dp;
1052 state = xfs_da_state_alloc();
1053 state->args = args;
1054 state->mp = dp->i_mount;
1055
1056 /*
1057 * Search to see if name exists, and get back a pointer to it.
1058 */
1059 error = xfs_da3_node_lookup_int(state, &retval);
1060 if (error || (retval != -EEXIST)) {
1061 if (error == 0)
1062 error = retval;
1063 goto out;
1064 }
1065
1066 /*
1067 * If there is an out-of-line value, de-allocate the blocks.
1068 * This is done before we remove the attribute so that we don't
1069 * overflow the maximum size of a transaction and/or hit a deadlock.
1070 */
1071 blk = &state->path.blk[ state->path.active-1 ];
1072 ASSERT(blk->bp != NULL);
1073 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1074 if (args->rmtblkno > 0) {
1075 /*
1076 * Fill in disk block numbers in the state structure
1077 * so that we can get the buffers back after we commit
1078 * several transactions in the following calls.
1079 */
1080 error = xfs_attr_fillstate(state);
1081 if (error)
1082 goto out;
1083
1084 /*
1085 * Mark the attribute as INCOMPLETE, then bunmapi() the
1086 * remote value.
1087 */
1088 error = xfs_attr3_leaf_setflag(args);
1089 if (error)
1090 goto out;
1091 error = xfs_attr_rmtval_remove(args);
1092 if (error)
1093 goto out;
1094
1095 /*
1096 * Refill the state structure with buffers, the prior calls
1097 * released our buffers.
1098 */
1099 error = xfs_attr_refillstate(state);
1100 if (error)
1101 goto out;
1102 }
1103
1104 /*
1105 * Remove the name and update the hashvals in the tree.
1106 */
1107 blk = &state->path.blk[ state->path.active-1 ];
1108 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1109 retval = xfs_attr3_leaf_remove(blk->bp, args);
1110 xfs_da3_fixhashpath(state, &state->path);
1111
1112 /*
1113 * Check to see if the tree needs to be collapsed.
1114 */
1115 if (retval && (state->path.active > 1)) {
1116 xfs_bmap_init(args->flist, args->firstblock);
1117 error = xfs_da3_join(state);
1118 if (!error)
1119 error = xfs_bmap_finish(&args->trans, args->flist, dp);
1120 if (error) {
1121 args->trans = NULL;
1122 xfs_bmap_cancel(args->flist);
1123 goto out;
1124 }
1125 /*
1126 * Commit the Btree join operation and start a new trans.
1127 */
1128 error = xfs_trans_roll(&args->trans, dp);
1129 if (error)
1130 goto out;
1131 }
1132
1133 /*
1134 * If the result is small enough, push it all into the inode.
1135 */
1136 if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
1137 /*
1138 * Have to get rid of the copy of this dabuf in the state.
1139 */
1140 ASSERT(state->path.active == 1);
1141 ASSERT(state->path.blk[0].bp);
1142 state->path.blk[0].bp = NULL;
1143
1144 error = xfs_attr3_leaf_read(args->trans, args->dp, 0, -1, &bp);
1145 if (error)
1146 goto out;
1147
1148 if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
1149 xfs_bmap_init(args->flist, args->firstblock);
1150 error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
1151 /* bp is gone due to xfs_da_shrink_inode */
1152 if (!error)
1153 error = xfs_bmap_finish(&args->trans,
1154 args->flist, dp);
1155 if (error) {
1156 args->trans = NULL;
1157 xfs_bmap_cancel(args->flist);
1158 goto out;
1159 }
1160 } else
1161 xfs_trans_brelse(args->trans, bp);
1162 }
1163 error = 0;
1164
1165 out:
1166 xfs_da_state_free(state);
1167 return error;
1168 }
1169
1170 /*
1171 * Fill in the disk block numbers in the state structure for the buffers
1172 * that are attached to the state structure.
1173 * This is done so that we can quickly reattach ourselves to those buffers
1174 * after some set of transaction commits have released these buffers.
1175 */
1176 STATIC int
1177 xfs_attr_fillstate(xfs_da_state_t *state)
1178 {
1179 xfs_da_state_path_t *path;
1180 xfs_da_state_blk_t *blk;
1181 int level;
1182
1183 trace_xfs_attr_fillstate(state->args);
1184
1185 /*
1186 * Roll down the "path" in the state structure, storing the on-disk
1187 * block number for those buffers in the "path".
1188 */
1189 path = &state->path;
1190 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1191 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
1192 if (blk->bp) {
1193 blk->disk_blkno = XFS_BUF_ADDR(blk->bp);
1194 blk->bp = NULL;
1195 } else {
1196 blk->disk_blkno = 0;
1197 }
1198 }
1199
1200 /*
1201 * Roll down the "altpath" in the state structure, storing the on-disk
1202 * block number for those buffers in the "altpath".
1203 */
1204 path = &state->altpath;
1205 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1206 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
1207 if (blk->bp) {
1208 blk->disk_blkno = XFS_BUF_ADDR(blk->bp);
1209 blk->bp = NULL;
1210 } else {
1211 blk->disk_blkno = 0;
1212 }
1213 }
1214
1215 return 0;
1216 }
1217
1218 /*
1219 * Reattach the buffers to the state structure based on the disk block
1220 * numbers stored in the state structure.
1221 * This is done after some set of transaction commits have released those
1222 * buffers from our grip.
1223 */
1224 STATIC int
1225 xfs_attr_refillstate(xfs_da_state_t *state)
1226 {
1227 xfs_da_state_path_t *path;
1228 xfs_da_state_blk_t *blk;
1229 int level, error;
1230
1231 trace_xfs_attr_refillstate(state->args);
1232
1233 /*
1234 * Roll down the "path" in the state structure, storing the on-disk
1235 * block number for those buffers in the "path".
1236 */
1237 path = &state->path;
1238 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1239 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
1240 if (blk->disk_blkno) {
1241 error = xfs_da3_node_read(state->args->trans,
1242 state->args->dp,
1243 blk->blkno, blk->disk_blkno,
1244 &blk->bp, XFS_ATTR_FORK);
1245 if (error)
1246 return error;
1247 } else {
1248 blk->bp = NULL;
1249 }
1250 }
1251
1252 /*
1253 * Roll down the "altpath" in the state structure, storing the on-disk
1254 * block number for those buffers in the "altpath".
1255 */
1256 path = &state->altpath;
1257 ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1258 for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
1259 if (blk->disk_blkno) {
1260 error = xfs_da3_node_read(state->args->trans,
1261 state->args->dp,
1262 blk->blkno, blk->disk_blkno,
1263 &blk->bp, XFS_ATTR_FORK);
1264 if (error)
1265 return error;
1266 } else {
1267 blk->bp = NULL;
1268 }
1269 }
1270
1271 return 0;
1272 }
1273
1274 /*
1275 * Look up a filename in a node attribute list.
1276 *
1277 * This routine gets called for any attribute fork that has more than one
1278 * block, ie: both true Btree attr lists and for single-leaf-blocks with
1279 * "remote" values taking up more blocks.
1280 */
1281 STATIC int
1282 xfs_attr_node_get(xfs_da_args_t *args)
1283 {
1284 xfs_da_state_t *state;
1285 xfs_da_state_blk_t *blk;
1286 int error, retval;
1287 int i;
1288
1289 trace_xfs_attr_node_get(args);
1290
1291 state = xfs_da_state_alloc();
1292 state->args = args;
1293 state->mp = args->dp->i_mount;
1294
1295 /*
1296 * Search to see if name exists, and get back a pointer to it.
1297 */
1298 error = xfs_da3_node_lookup_int(state, &retval);
1299 if (error) {
1300 retval = error;
1301 } else if (retval == -EEXIST) {
1302 blk = &state->path.blk[ state->path.active-1 ];
1303 ASSERT(blk->bp != NULL);
1304 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
1305
1306 /*
1307 * Get the value, local or "remote"
1308 */
1309 retval = xfs_attr3_leaf_getvalue(blk->bp, args);
1310 if (!retval && (args->rmtblkno > 0)
1311 && !(args->flags & ATTR_KERNOVAL)) {
1312 retval = xfs_attr_rmtval_get(args);
1313 }
1314 }
1315
1316 /*
1317 * If not in a transaction, we have to release all the buffers.
1318 */
1319 for (i = 0; i < state->path.active; i++) {
1320 xfs_trans_brelse(args->trans, state->path.blk[i].bp);
1321 state->path.blk[i].bp = NULL;
1322 }
1323
1324 xfs_da_state_free(state);
1325 return retval;
1326 }
Linux kernel - Deliverables
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