2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
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.
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.
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
20 #include "xfs_types.h"
24 #include "xfs_trans.h"
27 #include "xfs_mount.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_alloc_btree.h"
30 #include "xfs_ialloc_btree.h"
31 #include "xfs_dinode.h"
32 #include "xfs_inode.h"
33 #include "xfs_btree.h"
34 #include "xfs_ialloc.h"
35 #include "xfs_quota.h"
36 #include "xfs_utils.h"
37 #include "xfs_trans_priv.h"
38 #include "xfs_inode_item.h"
40 #include "xfs_trace.h"
44 * Define xfs inode iolock lockdep classes. We need to ensure that all active
45 * inodes are considered the same for lockdep purposes, including inodes that
46 * are recycled through the XFS_IRECLAIMABLE state. This is the the only way to
47 * guarantee the locks are considered the same when there are multiple lock
48 * initialisation siteѕ. Also, define a reclaimable inode class so it is
49 * obvious in lockdep reports which class the report is against.
51 static struct lock_class_key xfs_iolock_active
;
52 struct lock_class_key xfs_iolock_reclaimable
;
55 * Allocate and initialise an xfs_inode.
57 STATIC
struct xfs_inode
*
65 * if this didn't occur in transactions, we could use
66 * KM_MAYFAIL and return NULL here on ENOMEM. Set the
67 * code up to do this anyway.
69 ip
= kmem_zone_alloc(xfs_inode_zone
, KM_SLEEP
);
72 if (inode_init_always(mp
->m_super
, VFS_I(ip
))) {
73 kmem_zone_free(xfs_inode_zone
, ip
);
77 ASSERT(atomic_read(&ip
->i_pincount
) == 0);
78 ASSERT(!spin_is_locked(&ip
->i_flags_lock
));
79 ASSERT(!xfs_isiflocked(ip
));
80 ASSERT(ip
->i_ino
== 0);
82 mrlock_init(&ip
->i_iolock
, MRLOCK_BARRIER
, "xfsio", ip
->i_ino
);
83 lockdep_set_class_and_name(&ip
->i_iolock
.mr_lock
,
84 &xfs_iolock_active
, "xfs_iolock_active");
86 /* initialise the xfs inode */
89 memset(&ip
->i_imap
, 0, sizeof(struct xfs_imap
));
91 memset(&ip
->i_df
, 0, sizeof(xfs_ifork_t
));
93 ip
->i_delayed_blks
= 0;
94 memset(&ip
->i_d
, 0, sizeof(xfs_icdinode_t
));
100 xfs_inode_free_callback(
101 struct rcu_head
*head
)
103 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
104 struct xfs_inode
*ip
= XFS_I(inode
);
106 kmem_zone_free(xfs_inode_zone
, ip
);
111 struct xfs_inode
*ip
)
113 switch (ip
->i_d
.di_mode
& S_IFMT
) {
117 xfs_idestroy_fork(ip
, XFS_DATA_FORK
);
122 xfs_idestroy_fork(ip
, XFS_ATTR_FORK
);
125 ASSERT(!(ip
->i_itemp
->ili_item
.li_flags
& XFS_LI_IN_AIL
));
126 xfs_inode_item_destroy(ip
);
130 /* asserts to verify all state is correct here */
131 ASSERT(atomic_read(&ip
->i_pincount
) == 0);
132 ASSERT(!spin_is_locked(&ip
->i_flags_lock
));
133 ASSERT(!xfs_isiflocked(ip
));
136 * Because we use RCU freeing we need to ensure the inode always
137 * appears to be reclaimed with an invalid inode number when in the
138 * free state. The ip->i_flags_lock provides the barrier against lookup
141 spin_lock(&ip
->i_flags_lock
);
142 ip
->i_flags
= XFS_IRECLAIM
;
144 spin_unlock(&ip
->i_flags_lock
);
146 call_rcu(&VFS_I(ip
)->i_rcu
, xfs_inode_free_callback
);
150 * Check the validity of the inode we just found it the cache
154 struct xfs_perag
*pag
,
155 struct xfs_inode
*ip
,
158 int lock_flags
) __releases(RCU
)
160 struct inode
*inode
= VFS_I(ip
);
161 struct xfs_mount
*mp
= ip
->i_mount
;
165 * check for re-use of an inode within an RCU grace period due to the
166 * radix tree nodes not being updated yet. We monitor for this by
167 * setting the inode number to zero before freeing the inode structure.
168 * If the inode has been reallocated and set up, then the inode number
169 * will not match, so check for that, too.
171 spin_lock(&ip
->i_flags_lock
);
172 if (ip
->i_ino
!= ino
) {
173 trace_xfs_iget_skip(ip
);
174 XFS_STATS_INC(xs_ig_frecycle
);
181 * If we are racing with another cache hit that is currently
182 * instantiating this inode or currently recycling it out of
183 * reclaimabe state, wait for the initialisation to complete
186 * XXX(hch): eventually we should do something equivalent to
187 * wait_on_inode to wait for these flags to be cleared
188 * instead of polling for it.
190 if (ip
->i_flags
& (XFS_INEW
|XFS_IRECLAIM
)) {
191 trace_xfs_iget_skip(ip
);
192 XFS_STATS_INC(xs_ig_frecycle
);
198 * If lookup is racing with unlink return an error immediately.
200 if (ip
->i_d
.di_mode
== 0 && !(flags
& XFS_IGET_CREATE
)) {
206 * If IRECLAIMABLE is set, we've torn down the VFS inode already.
207 * Need to carefully get it back into useable state.
209 if (ip
->i_flags
& XFS_IRECLAIMABLE
) {
210 trace_xfs_iget_reclaim(ip
);
213 * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode
214 * from stomping over us while we recycle the inode. We can't
215 * clear the radix tree reclaimable tag yet as it requires
216 * pag_ici_lock to be held exclusive.
218 ip
->i_flags
|= XFS_IRECLAIM
;
220 spin_unlock(&ip
->i_flags_lock
);
223 error
= -inode_init_always(mp
->m_super
, inode
);
226 * Re-initializing the inode failed, and we are in deep
227 * trouble. Try to re-add it to the reclaim list.
230 spin_lock(&ip
->i_flags_lock
);
232 ip
->i_flags
&= ~(XFS_INEW
| XFS_IRECLAIM
);
233 ASSERT(ip
->i_flags
& XFS_IRECLAIMABLE
);
234 trace_xfs_iget_reclaim_fail(ip
);
238 spin_lock(&pag
->pag_ici_lock
);
239 spin_lock(&ip
->i_flags_lock
);
242 * Clear the per-lifetime state in the inode as we are now
243 * effectively a new inode and need to return to the initial
244 * state before reuse occurs.
246 ip
->i_flags
&= ~XFS_IRECLAIM_RESET_FLAGS
;
247 ip
->i_flags
|= XFS_INEW
;
248 __xfs_inode_clear_reclaim_tag(mp
, pag
, ip
);
249 inode
->i_state
= I_NEW
;
251 ASSERT(!rwsem_is_locked(&ip
->i_iolock
.mr_lock
));
252 mrlock_init(&ip
->i_iolock
, MRLOCK_BARRIER
, "xfsio", ip
->i_ino
);
253 lockdep_set_class_and_name(&ip
->i_iolock
.mr_lock
,
254 &xfs_iolock_active
, "xfs_iolock_active");
256 spin_unlock(&ip
->i_flags_lock
);
257 spin_unlock(&pag
->pag_ici_lock
);
259 /* If the VFS inode is being torn down, pause and try again. */
261 trace_xfs_iget_skip(ip
);
266 /* We've got a live one. */
267 spin_unlock(&ip
->i_flags_lock
);
269 trace_xfs_iget_hit(ip
);
273 xfs_ilock(ip
, lock_flags
);
275 xfs_iflags_clear(ip
, XFS_ISTALE
| XFS_IDONTCACHE
);
276 XFS_STATS_INC(xs_ig_found
);
281 spin_unlock(&ip
->i_flags_lock
);
289 struct xfs_mount
*mp
,
290 struct xfs_perag
*pag
,
293 struct xfs_inode
**ipp
,
297 struct xfs_inode
*ip
;
299 xfs_agino_t agino
= XFS_INO_TO_AGINO(mp
, ino
);
302 ip
= xfs_inode_alloc(mp
, ino
);
306 error
= xfs_iread(mp
, tp
, ip
, flags
);
310 trace_xfs_iget_miss(ip
);
312 if ((ip
->i_d
.di_mode
== 0) && !(flags
& XFS_IGET_CREATE
)) {
318 * Preload the radix tree so we can insert safely under the
319 * write spinlock. Note that we cannot sleep inside the preload
320 * region. Since we can be called from transaction context, don't
321 * recurse into the file system.
323 if (radix_tree_preload(GFP_NOFS
)) {
329 * Because the inode hasn't been added to the radix-tree yet it can't
330 * be found by another thread, so we can do the non-sleeping lock here.
333 if (!xfs_ilock_nowait(ip
, lock_flags
))
338 * These values must be set before inserting the inode into the radix
339 * tree as the moment it is inserted a concurrent lookup (allowed by the
340 * RCU locking mechanism) can find it and that lookup must see that this
341 * is an inode currently under construction (i.e. that XFS_INEW is set).
342 * The ip->i_flags_lock that protects the XFS_INEW flag forms the
343 * memory barrier that ensures this detection works correctly at lookup
347 if (flags
& XFS_IGET_DONTCACHE
)
348 iflags
|= XFS_IDONTCACHE
;
349 ip
->i_udquot
= ip
->i_gdquot
= NULL
;
350 xfs_iflags_set(ip
, iflags
);
352 /* insert the new inode */
353 spin_lock(&pag
->pag_ici_lock
);
354 error
= radix_tree_insert(&pag
->pag_ici_root
, agino
, ip
);
355 if (unlikely(error
)) {
356 WARN_ON(error
!= -EEXIST
);
357 XFS_STATS_INC(xs_ig_dup
);
359 goto out_preload_end
;
361 spin_unlock(&pag
->pag_ici_lock
);
362 radix_tree_preload_end();
368 spin_unlock(&pag
->pag_ici_lock
);
369 radix_tree_preload_end();
371 xfs_iunlock(ip
, lock_flags
);
373 __destroy_inode(VFS_I(ip
));
379 * Look up an inode by number in the given file system.
380 * The inode is looked up in the cache held in each AG.
381 * If the inode is found in the cache, initialise the vfs inode
384 * If it is not in core, read it in from the file system's device,
385 * add it to the cache and initialise the vfs inode.
387 * The inode is locked according to the value of the lock_flags parameter.
388 * This flag parameter indicates how and if the inode's IO lock and inode lock
391 * mp -- the mount point structure for the current file system. It points
392 * to the inode hash table.
393 * tp -- a pointer to the current transaction if there is one. This is
394 * simply passed through to the xfs_iread() call.
395 * ino -- the number of the inode desired. This is the unique identifier
396 * within the file system for the inode being requested.
397 * lock_flags -- flags indicating how to lock the inode. See the comment
398 * for xfs_ilock() for a list of valid values.
415 * xfs_reclaim_inode() uses the ILOCK to ensure an inode
416 * doesn't get freed while it's being referenced during a
417 * radix tree traversal here. It assumes this function
418 * aqcuires only the ILOCK (and therefore it has no need to
419 * involve the IOLOCK in this synchronization).
421 ASSERT((lock_flags
& (XFS_IOLOCK_EXCL
| XFS_IOLOCK_SHARED
)) == 0);
423 /* reject inode numbers outside existing AGs */
424 if (!ino
|| XFS_INO_TO_AGNO(mp
, ino
) >= mp
->m_sb
.sb_agcount
)
427 /* get the perag structure and ensure that it's inode capable */
428 pag
= xfs_perag_get(mp
, XFS_INO_TO_AGNO(mp
, ino
));
429 agino
= XFS_INO_TO_AGINO(mp
, ino
);
434 ip
= radix_tree_lookup(&pag
->pag_ici_root
, agino
);
437 error
= xfs_iget_cache_hit(pag
, ip
, ino
, flags
, lock_flags
);
439 goto out_error_or_again
;
442 XFS_STATS_INC(xs_ig_missed
);
444 error
= xfs_iget_cache_miss(mp
, pag
, tp
, ino
, &ip
,
447 goto out_error_or_again
;
454 * If we have a real type for an on-disk inode, we can set ops(&unlock)
455 * now. If it's a new inode being created, xfs_ialloc will handle it.
457 if (xfs_iflags_test(ip
, XFS_INEW
) && ip
->i_d
.di_mode
!= 0)
462 if (error
== EAGAIN
) {
471 * This is a wrapper routine around the xfs_ilock() routine
472 * used to centralize some grungy code. It is used in places
473 * that wish to lock the inode solely for reading the extents.
474 * The reason these places can't just call xfs_ilock(SHARED)
475 * is that the inode lock also guards to bringing in of the
476 * extents from disk for a file in b-tree format. If the inode
477 * is in b-tree format, then we need to lock the inode exclusively
478 * until the extents are read in. Locking it exclusively all
479 * the time would limit our parallelism unnecessarily, though.
480 * What we do instead is check to see if the extents have been
481 * read in yet, and only lock the inode exclusively if they
484 * The function returns a value which should be given to the
485 * corresponding xfs_iunlock_map_shared(). This value is
486 * the mode in which the lock was actually taken.
489 xfs_ilock_map_shared(
494 if ((ip
->i_d
.di_format
== XFS_DINODE_FMT_BTREE
) &&
495 ((ip
->i_df
.if_flags
& XFS_IFEXTENTS
) == 0)) {
496 lock_mode
= XFS_ILOCK_EXCL
;
498 lock_mode
= XFS_ILOCK_SHARED
;
501 xfs_ilock(ip
, lock_mode
);
507 * This is simply the unlock routine to go with xfs_ilock_map_shared().
508 * All it does is call xfs_iunlock() with the given lock_mode.
511 xfs_iunlock_map_shared(
513 unsigned int lock_mode
)
515 xfs_iunlock(ip
, lock_mode
);
519 * The xfs inode contains 2 locks: a multi-reader lock called the
520 * i_iolock and a multi-reader lock called the i_lock. This routine
521 * allows either or both of the locks to be obtained.
523 * The 2 locks should always be ordered so that the IO lock is
524 * obtained first in order to prevent deadlock.
526 * ip -- the inode being locked
527 * lock_flags -- this parameter indicates the inode's locks
528 * to be locked. It can be:
533 * XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED,
534 * XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL,
535 * XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED,
536 * XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL
544 * You can't set both SHARED and EXCL for the same lock,
545 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
546 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
548 ASSERT((lock_flags
& (XFS_IOLOCK_SHARED
| XFS_IOLOCK_EXCL
)) !=
549 (XFS_IOLOCK_SHARED
| XFS_IOLOCK_EXCL
));
550 ASSERT((lock_flags
& (XFS_ILOCK_SHARED
| XFS_ILOCK_EXCL
)) !=
551 (XFS_ILOCK_SHARED
| XFS_ILOCK_EXCL
));
552 ASSERT((lock_flags
& ~(XFS_LOCK_MASK
| XFS_LOCK_DEP_MASK
)) == 0);
554 if (lock_flags
& XFS_IOLOCK_EXCL
)
555 mrupdate_nested(&ip
->i_iolock
, XFS_IOLOCK_DEP(lock_flags
));
556 else if (lock_flags
& XFS_IOLOCK_SHARED
)
557 mraccess_nested(&ip
->i_iolock
, XFS_IOLOCK_DEP(lock_flags
));
559 if (lock_flags
& XFS_ILOCK_EXCL
)
560 mrupdate_nested(&ip
->i_lock
, XFS_ILOCK_DEP(lock_flags
));
561 else if (lock_flags
& XFS_ILOCK_SHARED
)
562 mraccess_nested(&ip
->i_lock
, XFS_ILOCK_DEP(lock_flags
));
564 trace_xfs_ilock(ip
, lock_flags
, _RET_IP_
);
568 * This is just like xfs_ilock(), except that the caller
569 * is guaranteed not to sleep. It returns 1 if it gets
570 * the requested locks and 0 otherwise. If the IO lock is
571 * obtained but the inode lock cannot be, then the IO lock
572 * is dropped before returning.
574 * ip -- the inode being locked
575 * lock_flags -- this parameter indicates the inode's locks to be
576 * to be locked. See the comment for xfs_ilock() for a list
585 * You can't set both SHARED and EXCL for the same lock,
586 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
587 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
589 ASSERT((lock_flags
& (XFS_IOLOCK_SHARED
| XFS_IOLOCK_EXCL
)) !=
590 (XFS_IOLOCK_SHARED
| XFS_IOLOCK_EXCL
));
591 ASSERT((lock_flags
& (XFS_ILOCK_SHARED
| XFS_ILOCK_EXCL
)) !=
592 (XFS_ILOCK_SHARED
| XFS_ILOCK_EXCL
));
593 ASSERT((lock_flags
& ~(XFS_LOCK_MASK
| XFS_LOCK_DEP_MASK
)) == 0);
595 if (lock_flags
& XFS_IOLOCK_EXCL
) {
596 if (!mrtryupdate(&ip
->i_iolock
))
598 } else if (lock_flags
& XFS_IOLOCK_SHARED
) {
599 if (!mrtryaccess(&ip
->i_iolock
))
602 if (lock_flags
& XFS_ILOCK_EXCL
) {
603 if (!mrtryupdate(&ip
->i_lock
))
604 goto out_undo_iolock
;
605 } else if (lock_flags
& XFS_ILOCK_SHARED
) {
606 if (!mrtryaccess(&ip
->i_lock
))
607 goto out_undo_iolock
;
609 trace_xfs_ilock_nowait(ip
, lock_flags
, _RET_IP_
);
613 if (lock_flags
& XFS_IOLOCK_EXCL
)
614 mrunlock_excl(&ip
->i_iolock
);
615 else if (lock_flags
& XFS_IOLOCK_SHARED
)
616 mrunlock_shared(&ip
->i_iolock
);
622 * xfs_iunlock() is used to drop the inode locks acquired with
623 * xfs_ilock() and xfs_ilock_nowait(). The caller must pass
624 * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
625 * that we know which locks to drop.
627 * ip -- the inode being unlocked
628 * lock_flags -- this parameter indicates the inode's locks to be
629 * to be unlocked. See the comment for xfs_ilock() for a list
630 * of valid values for this parameter.
639 * You can't set both SHARED and EXCL for the same lock,
640 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
641 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
643 ASSERT((lock_flags
& (XFS_IOLOCK_SHARED
| XFS_IOLOCK_EXCL
)) !=
644 (XFS_IOLOCK_SHARED
| XFS_IOLOCK_EXCL
));
645 ASSERT((lock_flags
& (XFS_ILOCK_SHARED
| XFS_ILOCK_EXCL
)) !=
646 (XFS_ILOCK_SHARED
| XFS_ILOCK_EXCL
));
647 ASSERT((lock_flags
& ~(XFS_LOCK_MASK
| XFS_LOCK_DEP_MASK
)) == 0);
648 ASSERT(lock_flags
!= 0);
650 if (lock_flags
& XFS_IOLOCK_EXCL
)
651 mrunlock_excl(&ip
->i_iolock
);
652 else if (lock_flags
& XFS_IOLOCK_SHARED
)
653 mrunlock_shared(&ip
->i_iolock
);
655 if (lock_flags
& XFS_ILOCK_EXCL
)
656 mrunlock_excl(&ip
->i_lock
);
657 else if (lock_flags
& XFS_ILOCK_SHARED
)
658 mrunlock_shared(&ip
->i_lock
);
660 trace_xfs_iunlock(ip
, lock_flags
, _RET_IP_
);
664 * give up write locks. the i/o lock cannot be held nested
665 * if it is being demoted.
672 ASSERT(lock_flags
& (XFS_IOLOCK_EXCL
|XFS_ILOCK_EXCL
));
673 ASSERT((lock_flags
& ~(XFS_IOLOCK_EXCL
|XFS_ILOCK_EXCL
)) == 0);
675 if (lock_flags
& XFS_ILOCK_EXCL
)
676 mrdemote(&ip
->i_lock
);
677 if (lock_flags
& XFS_IOLOCK_EXCL
)
678 mrdemote(&ip
->i_iolock
);
680 trace_xfs_ilock_demote(ip
, lock_flags
, _RET_IP_
);
689 if (lock_flags
& (XFS_ILOCK_EXCL
|XFS_ILOCK_SHARED
)) {
690 if (!(lock_flags
& XFS_ILOCK_SHARED
))
691 return !!ip
->i_lock
.mr_writer
;
692 return rwsem_is_locked(&ip
->i_lock
.mr_lock
);
695 if (lock_flags
& (XFS_IOLOCK_EXCL
|XFS_IOLOCK_SHARED
)) {
696 if (!(lock_flags
& XFS_IOLOCK_SHARED
))
697 return !!ip
->i_iolock
.mr_writer
;
698 return rwsem_is_locked(&ip
->i_iolock
.mr_lock
);
708 struct xfs_inode
*ip
)
710 wait_queue_head_t
*wq
= bit_waitqueue(&ip
->i_flags
, __XFS_IFLOCK_BIT
);
711 DEFINE_WAIT_BIT(wait
, &ip
->i_flags
, __XFS_IFLOCK_BIT
);
714 prepare_to_wait_exclusive(wq
, &wait
.wait
, TASK_UNINTERRUPTIBLE
);
715 if (xfs_isiflocked(ip
))
717 } while (!xfs_iflock_nowait(ip
));
719 finish_wait(wq
, &wait
.wait
);