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_types.h"
21 #include "xfs_acl.h"
22 #include "xfs_bit.h"
23 #include "xfs_log.h"
24 #include "xfs_inum.h"
25 #include "xfs_trans.h"
26 #include "xfs_sb.h"
27 #include "xfs_ag.h"
28 #include "xfs_mount.h"
29 #include "xfs_bmap_btree.h"
30 #include "xfs_alloc_btree.h"
31 #include "xfs_ialloc_btree.h"
32 #include "xfs_dinode.h"
33 #include "xfs_inode.h"
34 #include "xfs_btree.h"
35 #include "xfs_ialloc.h"
36 #include "xfs_quota.h"
37 #include "xfs_utils.h"
38 #include "xfs_trans_priv.h"
39 #include "xfs_inode_item.h"
40 #include "xfs_bmap.h"
41 #include "xfs_btree_trace.h"
42 #include "xfs_trace.h"
43
44
45 /*
46 * Define xfs inode iolock lockdep classes. We need to ensure that all active
47 * inodes are considered the same for lockdep purposes, including inodes that
48 * are recycled through the XFS_IRECLAIMABLE state. This is the the only way to
49 * guarantee the locks are considered the same when there are multiple lock
50 * initialisation siteѕ. Also, define a reclaimable inode class so it is
51 * obvious in lockdep reports which class the report is against.
52 */
53 static struct lock_class_key xfs_iolock_active;
54 struct lock_class_key xfs_iolock_reclaimable;
55
56 /*
57 * Allocate and initialise an xfs_inode.
58 */
59 STATIC struct xfs_inode *
xfs_inode_alloc(struct xfs_mount * mp,xfs_ino_t ino)60 xfs_inode_alloc(
61 struct xfs_mount *mp,
62 xfs_ino_t ino)
63 {
64 struct xfs_inode *ip;
65
66 /*
67 * if this didn't occur in transactions, we could use
68 * KM_MAYFAIL and return NULL here on ENOMEM. Set the
69 * code up to do this anyway.
70 */
71 ip = kmem_zone_alloc(xfs_inode_zone, KM_SLEEP);
72 if (!ip)
73 return NULL;
74 if (inode_init_always(mp->m_super, VFS_I(ip))) {
75 kmem_zone_free(xfs_inode_zone, ip);
76 return NULL;
77 }
78
79 ASSERT(atomic_read(&ip->i_iocount) == 0);
80 ASSERT(atomic_read(&ip->i_pincount) == 0);
81 ASSERT(!spin_is_locked(&ip->i_flags_lock));
82 ASSERT(completion_done(&ip->i_flush));
83 ASSERT(ip->i_ino == 0);
84
85 mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
86 lockdep_set_class_and_name(&ip->i_iolock.mr_lock,
87 &xfs_iolock_active, "xfs_iolock_active");
88
89 /* initialise the xfs inode */
90 ip->i_ino = ino;
91 ip->i_mount = mp;
92 memset(&ip->i_imap, 0, sizeof(struct xfs_imap));
93 ip->i_afp = NULL;
94 memset(&ip->i_df, 0, sizeof(xfs_ifork_t));
95 ip->i_flags = 0;
96 ip->i_update_core = 0;
97 ip->i_delayed_blks = 0;
98 memset(&ip->i_d, 0, sizeof(xfs_icdinode_t));
99 ip->i_size = 0;
100 ip->i_new_size = 0;
101
102 return ip;
103 }
104
105 STATIC void
xfs_inode_free_callback(struct rcu_head * head)106 xfs_inode_free_callback(
107 struct rcu_head *head)
108 {
109 struct inode *inode = container_of(head, struct inode, i_rcu);
110 struct xfs_inode *ip = XFS_I(inode);
111
112 INIT_LIST_HEAD(&inode->i_dentry);
113 kmem_zone_free(xfs_inode_zone, ip);
114 }
115
116 void
xfs_inode_free(struct xfs_inode * ip)117 xfs_inode_free(
118 struct xfs_inode *ip)
119 {
120 switch (ip->i_d.di_mode & S_IFMT) {
121 case S_IFREG:
122 case S_IFDIR:
123 case S_IFLNK:
124 xfs_idestroy_fork(ip, XFS_DATA_FORK);
125 break;
126 }
127
128 if (ip->i_afp)
129 xfs_idestroy_fork(ip, XFS_ATTR_FORK);
130
131 if (ip->i_itemp) {
132 /*
133 * Only if we are shutting down the fs will we see an
134 * inode still in the AIL. If it is there, we should remove
135 * it to prevent a use-after-free from occurring.
136 */
137 xfs_log_item_t *lip = &ip->i_itemp->ili_item;
138 struct xfs_ail *ailp = lip->li_ailp;
139
140 ASSERT(((lip->li_flags & XFS_LI_IN_AIL) == 0) ||
141 XFS_FORCED_SHUTDOWN(ip->i_mount));
142 if (lip->li_flags & XFS_LI_IN_AIL) {
143 spin_lock(&ailp->xa_lock);
144 if (lip->li_flags & XFS_LI_IN_AIL)
145 xfs_trans_ail_delete(ailp, lip);
146 else
147 spin_unlock(&ailp->xa_lock);
148 }
149 xfs_inode_item_destroy(ip);
150 ip->i_itemp = NULL;
151 }
152
153 /* asserts to verify all state is correct here */
154 ASSERT(atomic_read(&ip->i_iocount) == 0);
155 ASSERT(atomic_read(&ip->i_pincount) == 0);
156 ASSERT(!spin_is_locked(&ip->i_flags_lock));
157 ASSERT(completion_done(&ip->i_flush));
158
159 /*
160 * Because we use RCU freeing we need to ensure the inode always
161 * appears to be reclaimed with an invalid inode number when in the
162 * free state. The ip->i_flags_lock provides the barrier against lookup
163 * races.
164 */
165 spin_lock(&ip->i_flags_lock);
166 ip->i_flags = XFS_IRECLAIM;
167 ip->i_ino = 0;
168 spin_unlock(&ip->i_flags_lock);
169
170 call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback);
171 }
172
173 /*
174 * Check the validity of the inode we just found it the cache
175 */
176 static int
xfs_iget_cache_hit(struct xfs_perag * pag,struct xfs_inode * ip,xfs_ino_t ino,int flags,int lock_flags)177 xfs_iget_cache_hit(
178 struct xfs_perag *pag,
179 struct xfs_inode *ip,
180 xfs_ino_t ino,
181 int flags,
182 int lock_flags) __releases(RCU)
183 {
184 struct inode *inode = VFS_I(ip);
185 struct xfs_mount *mp = ip->i_mount;
186 int error;
187
188 /*
189 * check for re-use of an inode within an RCU grace period due to the
190 * radix tree nodes not being updated yet. We monitor for this by
191 * setting the inode number to zero before freeing the inode structure.
192 * If the inode has been reallocated and set up, then the inode number
193 * will not match, so check for that, too.
194 */
195 spin_lock(&ip->i_flags_lock);
196 if (ip->i_ino != ino) {
197 trace_xfs_iget_skip(ip);
198 XFS_STATS_INC(xs_ig_frecycle);
199 error = EAGAIN;
200 goto out_error;
201 }
202
203
204 /*
205 * If we are racing with another cache hit that is currently
206 * instantiating this inode or currently recycling it out of
207 * reclaimabe state, wait for the initialisation to complete
208 * before continuing.
209 *
210 * XXX(hch): eventually we should do something equivalent to
211 * wait_on_inode to wait for these flags to be cleared
212 * instead of polling for it.
213 */
214 if (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) {
215 trace_xfs_iget_skip(ip);
216 XFS_STATS_INC(xs_ig_frecycle);
217 error = EAGAIN;
218 goto out_error;
219 }
220
221 /*
222 * If lookup is racing with unlink return an error immediately.
223 */
224 if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) {
225 error = ENOENT;
226 goto out_error;
227 }
228
229 /*
230 * If IRECLAIMABLE is set, we've torn down the VFS inode already.
231 * Need to carefully get it back into useable state.
232 */
233 if (ip->i_flags & XFS_IRECLAIMABLE) {
234 trace_xfs_iget_reclaim(ip);
235
236 /*
237 * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode
238 * from stomping over us while we recycle the inode. We can't
239 * clear the radix tree reclaimable tag yet as it requires
240 * pag_ici_lock to be held exclusive.
241 */
242 ip->i_flags |= XFS_IRECLAIM;
243
244 spin_unlock(&ip->i_flags_lock);
245 rcu_read_unlock();
246
247 error = -inode_init_always(mp->m_super, inode);
248 if (error) {
249 /*
250 * Re-initializing the inode failed, and we are in deep
251 * trouble. Try to re-add it to the reclaim list.
252 */
253 rcu_read_lock();
254 spin_lock(&ip->i_flags_lock);
255
256 ip->i_flags &= ~XFS_INEW;
257 ip->i_flags |= XFS_IRECLAIMABLE;
258 __xfs_inode_set_reclaim_tag(pag, ip);
259 trace_xfs_iget_reclaim_fail(ip);
260 goto out_error;
261 }
262
263 spin_lock(&pag->pag_ici_lock);
264 spin_lock(&ip->i_flags_lock);
265 ip->i_flags &= ~(XFS_IRECLAIMABLE | XFS_IRECLAIM);
266 ip->i_flags |= XFS_INEW;
267 __xfs_inode_clear_reclaim_tag(mp, pag, ip);
268 inode->i_state = I_NEW;
269
270 ASSERT(!rwsem_is_locked(&ip->i_iolock.mr_lock));
271 mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
272 lockdep_set_class_and_name(&ip->i_iolock.mr_lock,
273 &xfs_iolock_active, "xfs_iolock_active");
274
275 spin_unlock(&ip->i_flags_lock);
276 spin_unlock(&pag->pag_ici_lock);
277 } else {
278 /* If the VFS inode is being torn down, pause and try again. */
279 if (!igrab(inode)) {
280 trace_xfs_iget_skip(ip);
281 error = EAGAIN;
282 goto out_error;
283 }
284
285 /* We've got a live one. */
286 spin_unlock(&ip->i_flags_lock);
287 rcu_read_unlock();
288 trace_xfs_iget_hit(ip);
289 }
290
291 if (lock_flags != 0)
292 xfs_ilock(ip, lock_flags);
293
294 xfs_iflags_clear(ip, XFS_ISTALE);
295 XFS_STATS_INC(xs_ig_found);
296
297 return 0;
298
299 out_error:
300 spin_unlock(&ip->i_flags_lock);
301 rcu_read_unlock();
302 return error;
303 }
304
305
306 static int
xfs_iget_cache_miss(struct xfs_mount * mp,struct xfs_perag * pag,xfs_trans_t * tp,xfs_ino_t ino,struct xfs_inode ** ipp,int flags,int lock_flags)307 xfs_iget_cache_miss(
308 struct xfs_mount *mp,
309 struct xfs_perag *pag,
310 xfs_trans_t *tp,
311 xfs_ino_t ino,
312 struct xfs_inode **ipp,
313 int flags,
314 int lock_flags)
315 {
316 struct xfs_inode *ip;
317 int error;
318 xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino);
319
320 ip = xfs_inode_alloc(mp, ino);
321 if (!ip)
322 return ENOMEM;
323
324 error = xfs_iread(mp, tp, ip, flags);
325 if (error)
326 goto out_destroy;
327
328 trace_xfs_iget_miss(ip);
329
330 if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) {
331 error = ENOENT;
332 goto out_destroy;
333 }
334
335 /*
336 * Preload the radix tree so we can insert safely under the
337 * write spinlock. Note that we cannot sleep inside the preload
338 * region.
339 */
340 if (radix_tree_preload(GFP_KERNEL)) {
341 error = EAGAIN;
342 goto out_destroy;
343 }
344
345 /*
346 * Because the inode hasn't been added to the radix-tree yet it can't
347 * be found by another thread, so we can do the non-sleeping lock here.
348 */
349 if (lock_flags) {
350 if (!xfs_ilock_nowait(ip, lock_flags))
351 BUG();
352 }
353
354 spin_lock(&pag->pag_ici_lock);
355
356 /* insert the new inode */
357 error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
358 if (unlikely(error)) {
359 WARN_ON(error != -EEXIST);
360 XFS_STATS_INC(xs_ig_dup);
361 error = EAGAIN;
362 goto out_preload_end;
363 }
364
365 /* These values _must_ be set before releasing the radix tree lock! */
366 ip->i_udquot = ip->i_gdquot = NULL;
367 xfs_iflags_set(ip, XFS_INEW);
368
369 spin_unlock(&pag->pag_ici_lock);
370 radix_tree_preload_end();
371
372 *ipp = ip;
373 return 0;
374
375 out_preload_end:
376 spin_unlock(&pag->pag_ici_lock);
377 radix_tree_preload_end();
378 if (lock_flags)
379 xfs_iunlock(ip, lock_flags);
380 out_destroy:
381 __destroy_inode(VFS_I(ip));
382 xfs_inode_free(ip);
383 return error;
384 }
385
386 /*
387 * Look up an inode by number in the given file system.
388 * The inode is looked up in the cache held in each AG.
389 * If the inode is found in the cache, initialise the vfs inode
390 * if necessary.
391 *
392 * If it is not in core, read it in from the file system's device,
393 * add it to the cache and initialise the vfs inode.
394 *
395 * The inode is locked according to the value of the lock_flags parameter.
396 * This flag parameter indicates how and if the inode's IO lock and inode lock
397 * should be taken.
398 *
399 * mp -- the mount point structure for the current file system. It points
400 * to the inode hash table.
401 * tp -- a pointer to the current transaction if there is one. This is
402 * simply passed through to the xfs_iread() call.
403 * ino -- the number of the inode desired. This is the unique identifier
404 * within the file system for the inode being requested.
405 * lock_flags -- flags indicating how to lock the inode. See the comment
406 * for xfs_ilock() for a list of valid values.
407 */
408 int
xfs_iget(xfs_mount_t * mp,xfs_trans_t * tp,xfs_ino_t ino,uint flags,uint lock_flags,xfs_inode_t ** ipp)409 xfs_iget(
410 xfs_mount_t *mp,
411 xfs_trans_t *tp,
412 xfs_ino_t ino,
413 uint flags,
414 uint lock_flags,
415 xfs_inode_t **ipp)
416 {
417 xfs_inode_t *ip;
418 int error;
419 xfs_perag_t *pag;
420 xfs_agino_t agino;
421
422 /* reject inode numbers outside existing AGs */
423 if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
424 return EINVAL;
425
426 /* get the perag structure and ensure that it's inode capable */
427 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
428 agino = XFS_INO_TO_AGINO(mp, ino);
429
430 again:
431 error = 0;
432 rcu_read_lock();
433 ip = radix_tree_lookup(&pag->pag_ici_root, agino);
434
435 if (ip) {
436 error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags);
437 if (error)
438 goto out_error_or_again;
439 } else {
440 rcu_read_unlock();
441 XFS_STATS_INC(xs_ig_missed);
442
443 error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip,
444 flags, lock_flags);
445 if (error)
446 goto out_error_or_again;
447 }
448 xfs_perag_put(pag);
449
450 *ipp = ip;
451
452 ASSERT(ip->i_df.if_ext_max ==
453 XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t));
454 /*
455 * If we have a real type for an on-disk inode, we can set ops(&unlock)
456 * now. If it's a new inode being created, xfs_ialloc will handle it.
457 */
458 if (xfs_iflags_test(ip, XFS_INEW) && ip->i_d.di_mode != 0)
459 xfs_setup_inode(ip);
460 return 0;
461
462 out_error_or_again:
463 if (error == EAGAIN) {
464 delay(1);
465 goto again;
466 }
467 xfs_perag_put(pag);
468 return error;
469 }
470
471 /*
472 * This is a wrapper routine around the xfs_ilock() routine
473 * used to centralize some grungy code. It is used in places
474 * that wish to lock the inode solely for reading the extents.
475 * The reason these places can't just call xfs_ilock(SHARED)
476 * is that the inode lock also guards to bringing in of the
477 * extents from disk for a file in b-tree format. If the inode
478 * is in b-tree format, then we need to lock the inode exclusively
479 * until the extents are read in. Locking it exclusively all
480 * the time would limit our parallelism unnecessarily, though.
481 * What we do instead is check to see if the extents have been
482 * read in yet, and only lock the inode exclusively if they
483 * have not.
484 *
485 * The function returns a value which should be given to the
486 * corresponding xfs_iunlock_map_shared(). This value is
487 * the mode in which the lock was actually taken.
488 */
489 uint
xfs_ilock_map_shared(xfs_inode_t * ip)490 xfs_ilock_map_shared(
491 xfs_inode_t *ip)
492 {
493 uint lock_mode;
494
495 if ((ip->i_d.di_format == XFS_DINODE_FMT_BTREE) &&
496 ((ip->i_df.if_flags & XFS_IFEXTENTS) == 0)) {
497 lock_mode = XFS_ILOCK_EXCL;
498 } else {
499 lock_mode = XFS_ILOCK_SHARED;
500 }
501
502 xfs_ilock(ip, lock_mode);
503
504 return lock_mode;
505 }
506
507 /*
508 * This is simply the unlock routine to go with xfs_ilock_map_shared().
509 * All it does is call xfs_iunlock() with the given lock_mode.
510 */
511 void
xfs_iunlock_map_shared(xfs_inode_t * ip,unsigned int lock_mode)512 xfs_iunlock_map_shared(
513 xfs_inode_t *ip,
514 unsigned int lock_mode)
515 {
516 xfs_iunlock(ip, lock_mode);
517 }
518
519 /*
520 * The xfs inode contains 2 locks: a multi-reader lock called the
521 * i_iolock and a multi-reader lock called the i_lock. This routine
522 * allows either or both of the locks to be obtained.
523 *
524 * The 2 locks should always be ordered so that the IO lock is
525 * obtained first in order to prevent deadlock.
526 *
527 * ip -- the inode being locked
528 * lock_flags -- this parameter indicates the inode's locks
529 * to be locked. It can be:
530 * XFS_IOLOCK_SHARED,
531 * XFS_IOLOCK_EXCL,
532 * XFS_ILOCK_SHARED,
533 * XFS_ILOCK_EXCL,
534 * XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED,
535 * XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL,
536 * XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED,
537 * XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL
538 */
539 void
xfs_ilock(xfs_inode_t * ip,uint lock_flags)540 xfs_ilock(
541 xfs_inode_t *ip,
542 uint lock_flags)
543 {
544 /*
545 * You can't set both SHARED and EXCL for the same lock,
546 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
547 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
548 */
549 ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
550 (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
551 ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
552 (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
553 ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
554
555 if (lock_flags & XFS_IOLOCK_EXCL)
556 mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
557 else if (lock_flags & XFS_IOLOCK_SHARED)
558 mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
559
560 if (lock_flags & XFS_ILOCK_EXCL)
561 mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
562 else if (lock_flags & XFS_ILOCK_SHARED)
563 mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
564
565 trace_xfs_ilock(ip, lock_flags, _RET_IP_);
566 }
567
568 /*
569 * This is just like xfs_ilock(), except that the caller
570 * is guaranteed not to sleep. It returns 1 if it gets
571 * the requested locks and 0 otherwise. If the IO lock is
572 * obtained but the inode lock cannot be, then the IO lock
573 * is dropped before returning.
574 *
575 * ip -- the inode being locked
576 * lock_flags -- this parameter indicates the inode's locks to be
577 * to be locked. See the comment for xfs_ilock() for a list
578 * of valid values.
579 */
580 int
xfs_ilock_nowait(xfs_inode_t * ip,uint lock_flags)581 xfs_ilock_nowait(
582 xfs_inode_t *ip,
583 uint lock_flags)
584 {
585 /*
586 * You can't set both SHARED and EXCL for the same lock,
587 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
588 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
589 */
590 ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
591 (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
592 ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
593 (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
594 ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
595
596 if (lock_flags & XFS_IOLOCK_EXCL) {
597 if (!mrtryupdate(&ip->i_iolock))
598 goto out;
599 } else if (lock_flags & XFS_IOLOCK_SHARED) {
600 if (!mrtryaccess(&ip->i_iolock))
601 goto out;
602 }
603 if (lock_flags & XFS_ILOCK_EXCL) {
604 if (!mrtryupdate(&ip->i_lock))
605 goto out_undo_iolock;
606 } else if (lock_flags & XFS_ILOCK_SHARED) {
607 if (!mrtryaccess(&ip->i_lock))
608 goto out_undo_iolock;
609 }
610 trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_);
611 return 1;
612
613 out_undo_iolock:
614 if (lock_flags & XFS_IOLOCK_EXCL)
615 mrunlock_excl(&ip->i_iolock);
616 else if (lock_flags & XFS_IOLOCK_SHARED)
617 mrunlock_shared(&ip->i_iolock);
618 out:
619 return 0;
620 }
621
622 /*
623 * xfs_iunlock() is used to drop the inode locks acquired with
624 * xfs_ilock() and xfs_ilock_nowait(). The caller must pass
625 * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
626 * that we know which locks to drop.
627 *
628 * ip -- the inode being unlocked
629 * lock_flags -- this parameter indicates the inode's locks to be
630 * to be unlocked. See the comment for xfs_ilock() for a list
631 * of valid values for this parameter.
632 *
633 */
634 void
xfs_iunlock(xfs_inode_t * ip,uint lock_flags)635 xfs_iunlock(
636 xfs_inode_t *ip,
637 uint lock_flags)
638 {
639 /*
640 * You can't set both SHARED and EXCL for the same lock,
641 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
642 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
643 */
644 ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
645 (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
646 ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
647 (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
648 ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_IUNLOCK_NONOTIFY |
649 XFS_LOCK_DEP_MASK)) == 0);
650 ASSERT(lock_flags != 0);
651
652 if (lock_flags & XFS_IOLOCK_EXCL)
653 mrunlock_excl(&ip->i_iolock);
654 else if (lock_flags & XFS_IOLOCK_SHARED)
655 mrunlock_shared(&ip->i_iolock);
656
657 if (lock_flags & XFS_ILOCK_EXCL)
658 mrunlock_excl(&ip->i_lock);
659 else if (lock_flags & XFS_ILOCK_SHARED)
660 mrunlock_shared(&ip->i_lock);
661
662 if ((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) &&
663 !(lock_flags & XFS_IUNLOCK_NONOTIFY) && ip->i_itemp) {
664 /*
665 * Let the AIL know that this item has been unlocked in case
666 * it is in the AIL and anyone is waiting on it. Don't do
667 * this if the caller has asked us not to.
668 */
669 xfs_trans_unlocked_item(ip->i_itemp->ili_item.li_ailp,
670 (xfs_log_item_t*)(ip->i_itemp));
671 }
672 trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
673 }
674
675 /*
676 * give up write locks. the i/o lock cannot be held nested
677 * if it is being demoted.
678 */
679 void
xfs_ilock_demote(xfs_inode_t * ip,uint lock_flags)680 xfs_ilock_demote(
681 xfs_inode_t *ip,
682 uint lock_flags)
683 {
684 ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL));
685 ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
686
687 if (lock_flags & XFS_ILOCK_EXCL)
688 mrdemote(&ip->i_lock);
689 if (lock_flags & XFS_IOLOCK_EXCL)
690 mrdemote(&ip->i_iolock);
691
692 trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
693 }
694
695 #ifdef DEBUG
696 int
xfs_isilocked(xfs_inode_t * ip,uint lock_flags)697 xfs_isilocked(
698 xfs_inode_t *ip,
699 uint lock_flags)
700 {
701 if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
702 if (!(lock_flags & XFS_ILOCK_SHARED))
703 return !!ip->i_lock.mr_writer;
704 return rwsem_is_locked(&ip->i_lock.mr_lock);
705 }
706
707 if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
708 if (!(lock_flags & XFS_IOLOCK_SHARED))
709 return !!ip->i_iolock.mr_writer;
710 return rwsem_is_locked(&ip->i_iolock.mr_lock);
711 }
712
713 ASSERT(0);
714 return 0;
715 }
716 #endif
717