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TOMOYO Linux Cross Reference
Linux/fs/xfs/libxfs/xfs_attr.c

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

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