4 * (C) 1997 Linus Torvalds
7 #include <linux/config.h>
10 #include <linux/dcache.h>
11 #include <linux/init.h>
12 #include <linux/quotaops.h>
13 #include <linux/slab.h>
14 #include <linux/writeback.h>
15 #include <linux/module.h>
16 #include <linux/backing-dev.h>
17 #include <linux/wait.h>
18 #include <linux/hash.h>
19 #include <linux/swap.h>
20 #include <linux/security.h>
21 #include <linux/pagemap.h>
22 #include <linux/cdev.h>
23 #include <linux/bootmem.h>
24 #include <linux/inotify.h>
25 #include <linux/mount.h>
28 * This is needed for the following functions:
30 * - invalidate_inode_buffers
33 * FIXME: remove all knowledge of the buffer layer from this file
35 #include <linux/buffer_head.h>
38 * New inode.c implementation.
40 * This implementation has the basic premise of trying
41 * to be extremely low-overhead and SMP-safe, yet be
42 * simple enough to be "obviously correct".
47 /* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */
49 /* #define INODE_PARANOIA 1 */
50 /* #define INODE_DEBUG 1 */
53 * Inode lookup is no longer as critical as it used to be:
54 * most of the lookups are going to be through the dcache.
56 #define I_HASHBITS i_hash_shift
57 #define I_HASHMASK i_hash_mask
59 static unsigned int i_hash_mask __read_mostly
;
60 static unsigned int i_hash_shift __read_mostly
;
63 * Each inode can be on two separate lists. One is
64 * the hash list of the inode, used for lookups. The
65 * other linked list is the "type" list:
66 * "in_use" - valid inode, i_count > 0, i_nlink > 0
67 * "dirty" - as "in_use" but also dirty
68 * "unused" - valid inode, i_count = 0
70 * A "dirty" list is maintained for each super block,
71 * allowing for low-overhead inode sync() operations.
74 LIST_HEAD(inode_in_use
);
75 LIST_HEAD(inode_unused
);
76 static struct hlist_head
*inode_hashtable __read_mostly
;
79 * A simple spinlock to protect the list manipulations.
81 * NOTE! You also have to own the lock if you change
82 * the i_state of an inode while it is in use..
84 DEFINE_SPINLOCK(inode_lock
);
87 * iprune_mutex provides exclusion between the kswapd or try_to_free_pages
88 * icache shrinking path, and the umount path. Without this exclusion,
89 * by the time prune_icache calls iput for the inode whose pages it has
90 * been invalidating, or by the time it calls clear_inode & destroy_inode
91 * from its final dispose_list, the struct super_block they refer to
92 * (for inode->i_sb->s_op) may already have been freed and reused.
94 static DEFINE_MUTEX(iprune_mutex
);
97 * Statistics gathering..
99 struct inodes_stat_t inodes_stat
;
101 static kmem_cache_t
* inode_cachep __read_mostly
;
103 static struct inode
*alloc_inode(struct super_block
*sb
)
105 static struct address_space_operations empty_aops
;
106 static struct inode_operations empty_iops
;
107 static const struct file_operations empty_fops
;
110 if (sb
->s_op
->alloc_inode
)
111 inode
= sb
->s_op
->alloc_inode(sb
);
113 inode
= (struct inode
*) kmem_cache_alloc(inode_cachep
, SLAB_KERNEL
);
116 struct address_space
* const mapping
= &inode
->i_data
;
119 inode
->i_blkbits
= sb
->s_blocksize_bits
;
121 atomic_set(&inode
->i_count
, 1);
122 inode
->i_op
= &empty_iops
;
123 inode
->i_fop
= &empty_fops
;
125 atomic_set(&inode
->i_writecount
, 0);
129 inode
->i_generation
= 0;
131 memset(&inode
->i_dquot
, 0, sizeof(inode
->i_dquot
));
133 inode
->i_pipe
= NULL
;
134 inode
->i_bdev
= NULL
;
135 inode
->i_cdev
= NULL
;
137 inode
->i_security
= NULL
;
138 inode
->dirtied_when
= 0;
139 if (security_inode_alloc(inode
)) {
140 if (inode
->i_sb
->s_op
->destroy_inode
)
141 inode
->i_sb
->s_op
->destroy_inode(inode
);
143 kmem_cache_free(inode_cachep
, (inode
));
147 mapping
->a_ops
= &empty_aops
;
148 mapping
->host
= inode
;
150 mapping_set_gfp_mask(mapping
, GFP_HIGHUSER
);
151 mapping
->assoc_mapping
= NULL
;
152 mapping
->backing_dev_info
= &default_backing_dev_info
;
155 * If the block_device provides a backing_dev_info for client
156 * inodes then use that. Otherwise the inode share the bdev's
160 struct backing_dev_info
*bdi
;
162 bdi
= sb
->s_bdev
->bd_inode_backing_dev_info
;
164 bdi
= sb
->s_bdev
->bd_inode
->i_mapping
->backing_dev_info
;
165 mapping
->backing_dev_info
= bdi
;
167 memset(&inode
->u
, 0, sizeof(inode
->u
));
168 inode
->i_mapping
= mapping
;
173 void destroy_inode(struct inode
*inode
)
175 if (inode_has_buffers(inode
))
177 security_inode_free(inode
);
178 if (inode
->i_sb
->s_op
->destroy_inode
)
179 inode
->i_sb
->s_op
->destroy_inode(inode
);
181 kmem_cache_free(inode_cachep
, (inode
));
186 * These are initializations that only need to be done
187 * once, because the fields are idempotent across use
188 * of the inode, so let the slab aware of that.
190 void inode_init_once(struct inode
*inode
)
192 memset(inode
, 0, sizeof(*inode
));
193 INIT_HLIST_NODE(&inode
->i_hash
);
194 INIT_LIST_HEAD(&inode
->i_dentry
);
195 INIT_LIST_HEAD(&inode
->i_devices
);
196 mutex_init(&inode
->i_mutex
);
197 init_rwsem(&inode
->i_alloc_sem
);
198 INIT_RADIX_TREE(&inode
->i_data
.page_tree
, GFP_ATOMIC
);
199 rwlock_init(&inode
->i_data
.tree_lock
);
200 spin_lock_init(&inode
->i_data
.i_mmap_lock
);
201 INIT_LIST_HEAD(&inode
->i_data
.private_list
);
202 spin_lock_init(&inode
->i_data
.private_lock
);
203 INIT_RAW_PRIO_TREE_ROOT(&inode
->i_data
.i_mmap
);
204 INIT_LIST_HEAD(&inode
->i_data
.i_mmap_nonlinear
);
205 spin_lock_init(&inode
->i_lock
);
206 i_size_ordered_init(inode
);
207 #ifdef CONFIG_INOTIFY
208 INIT_LIST_HEAD(&inode
->inotify_watches
);
209 mutex_init(&inode
->inotify_mutex
);
213 EXPORT_SYMBOL(inode_init_once
);
215 static void init_once(void * foo
, kmem_cache_t
* cachep
, unsigned long flags
)
217 struct inode
* inode
= (struct inode
*) foo
;
219 if ((flags
& (SLAB_CTOR_VERIFY
|SLAB_CTOR_CONSTRUCTOR
)) ==
220 SLAB_CTOR_CONSTRUCTOR
)
221 inode_init_once(inode
);
225 * inode_lock must be held
227 void __iget(struct inode
* inode
)
229 if (atomic_read(&inode
->i_count
)) {
230 atomic_inc(&inode
->i_count
);
233 atomic_inc(&inode
->i_count
);
234 if (!(inode
->i_state
& (I_DIRTY
|I_LOCK
)))
235 list_move(&inode
->i_list
, &inode_in_use
);
236 inodes_stat
.nr_unused
--;
240 * clear_inode - clear an inode
241 * @inode: inode to clear
243 * This is called by the filesystem to tell us
244 * that the inode is no longer useful. We just
245 * terminate it with extreme prejudice.
247 void clear_inode(struct inode
*inode
)
250 invalidate_inode_buffers(inode
);
252 if (inode
->i_data
.nrpages
)
254 if (!(inode
->i_state
& I_FREEING
))
256 if (inode
->i_state
& I_CLEAR
)
258 wait_on_inode(inode
);
260 if (inode
->i_sb
&& inode
->i_sb
->s_op
->clear_inode
)
261 inode
->i_sb
->s_op
->clear_inode(inode
);
266 inode
->i_state
= I_CLEAR
;
269 EXPORT_SYMBOL(clear_inode
);
272 * dispose_list - dispose of the contents of a local list
273 * @head: the head of the list to free
275 * Dispose-list gets a local list with local inodes in it, so it doesn't
276 * need to worry about list corruption and SMP locks.
278 static void dispose_list(struct list_head
*head
)
282 while (!list_empty(head
)) {
285 inode
= list_entry(head
->next
, struct inode
, i_list
);
286 list_del(&inode
->i_list
);
288 if (inode
->i_data
.nrpages
)
289 truncate_inode_pages(&inode
->i_data
, 0);
292 spin_lock(&inode_lock
);
293 hlist_del_init(&inode
->i_hash
);
294 list_del_init(&inode
->i_sb_list
);
295 spin_unlock(&inode_lock
);
297 wake_up_inode(inode
);
298 destroy_inode(inode
);
301 spin_lock(&inode_lock
);
302 inodes_stat
.nr_inodes
-= nr_disposed
;
303 spin_unlock(&inode_lock
);
307 * Invalidate all inodes for a device.
309 static int invalidate_list(struct list_head
*head
, struct list_head
*dispose
)
311 struct list_head
*next
;
312 int busy
= 0, count
= 0;
316 struct list_head
* tmp
= next
;
317 struct inode
* inode
;
320 * We can reschedule here without worrying about the list's
321 * consistency because the per-sb list of inodes must not
322 * change during umount anymore, and because iprune_mutex keeps
323 * shrink_icache_memory() away.
325 cond_resched_lock(&inode_lock
);
330 inode
= list_entry(tmp
, struct inode
, i_sb_list
);
331 invalidate_inode_buffers(inode
);
332 if (!atomic_read(&inode
->i_count
)) {
333 list_move(&inode
->i_list
, dispose
);
334 inode
->i_state
|= I_FREEING
;
340 /* only unused inodes may be cached with i_count zero */
341 inodes_stat
.nr_unused
-= count
;
346 * invalidate_inodes - discard the inodes on a device
349 * Discard all of the inodes for a given superblock. If the discard
350 * fails because there are busy inodes then a non zero value is returned.
351 * If the discard is successful all the inodes have been discarded.
353 int invalidate_inodes(struct super_block
* sb
)
356 LIST_HEAD(throw_away
);
358 mutex_lock(&iprune_mutex
);
359 spin_lock(&inode_lock
);
360 inotify_unmount_inodes(&sb
->s_inodes
);
361 busy
= invalidate_list(&sb
->s_inodes
, &throw_away
);
362 spin_unlock(&inode_lock
);
364 dispose_list(&throw_away
);
365 mutex_unlock(&iprune_mutex
);
370 EXPORT_SYMBOL(invalidate_inodes
);
372 int __invalidate_device(struct block_device
*bdev
)
374 struct super_block
*sb
= get_super(bdev
);
379 * no need to lock the super, get_super holds the
380 * read mutex so the filesystem cannot go away
381 * under us (->put_super runs with the write lock
384 shrink_dcache_sb(sb
);
385 res
= invalidate_inodes(sb
);
388 invalidate_bdev(bdev
, 0);
391 EXPORT_SYMBOL(__invalidate_device
);
393 static int can_unuse(struct inode
*inode
)
397 if (inode_has_buffers(inode
))
399 if (atomic_read(&inode
->i_count
))
401 if (inode
->i_data
.nrpages
)
407 * Scan `goal' inodes on the unused list for freeable ones. They are moved to
408 * a temporary list and then are freed outside inode_lock by dispose_list().
410 * Any inodes which are pinned purely because of attached pagecache have their
411 * pagecache removed. We expect the final iput() on that inode to add it to
412 * the front of the inode_unused list. So look for it there and if the
413 * inode is still freeable, proceed. The right inode is found 99.9% of the
414 * time in testing on a 4-way.
416 * If the inode has metadata buffers attached to mapping->private_list then
417 * try to remove them.
419 static void prune_icache(int nr_to_scan
)
424 unsigned long reap
= 0;
426 mutex_lock(&iprune_mutex
);
427 spin_lock(&inode_lock
);
428 for (nr_scanned
= 0; nr_scanned
< nr_to_scan
; nr_scanned
++) {
431 if (list_empty(&inode_unused
))
434 inode
= list_entry(inode_unused
.prev
, struct inode
, i_list
);
436 if (inode
->i_state
|| atomic_read(&inode
->i_count
)) {
437 list_move(&inode
->i_list
, &inode_unused
);
440 if (inode_has_buffers(inode
) || inode
->i_data
.nrpages
) {
442 spin_unlock(&inode_lock
);
443 if (remove_inode_buffers(inode
))
444 reap
+= invalidate_inode_pages(&inode
->i_data
);
446 spin_lock(&inode_lock
);
448 if (inode
!= list_entry(inode_unused
.next
,
449 struct inode
, i_list
))
450 continue; /* wrong inode or list_empty */
451 if (!can_unuse(inode
))
454 list_move(&inode
->i_list
, &freeable
);
455 inode
->i_state
|= I_FREEING
;
458 inodes_stat
.nr_unused
-= nr_pruned
;
459 spin_unlock(&inode_lock
);
461 dispose_list(&freeable
);
462 mutex_unlock(&iprune_mutex
);
464 if (current_is_kswapd())
465 mod_page_state(kswapd_inodesteal
, reap
);
467 mod_page_state(pginodesteal
, reap
);
471 * shrink_icache_memory() will attempt to reclaim some unused inodes. Here,
472 * "unused" means that no dentries are referring to the inodes: the files are
473 * not open and the dcache references to those inodes have already been
476 * This function is passed the number of inodes to scan, and it returns the
477 * total number of remaining possibly-reclaimable inodes.
479 static int shrink_icache_memory(int nr
, gfp_t gfp_mask
)
483 * Nasty deadlock avoidance. We may hold various FS locks,
484 * and we don't want to recurse into the FS that called us
485 * in clear_inode() and friends..
487 if (!(gfp_mask
& __GFP_FS
))
491 return (inodes_stat
.nr_unused
/ 100) * sysctl_vfs_cache_pressure
;
494 static void __wait_on_freeing_inode(struct inode
*inode
);
496 * Called with the inode lock held.
497 * NOTE: we are not increasing the inode-refcount, you must call __iget()
498 * by hand after calling find_inode now! This simplifies iunique and won't
499 * add any additional branch in the common code.
501 static struct inode
* find_inode(struct super_block
* sb
, struct hlist_head
*head
, int (*test
)(struct inode
*, void *), void *data
)
503 struct hlist_node
*node
;
504 struct inode
* inode
= NULL
;
507 hlist_for_each (node
, head
) {
508 inode
= hlist_entry(node
, struct inode
, i_hash
);
509 if (inode
->i_sb
!= sb
)
511 if (!test(inode
, data
))
513 if (inode
->i_state
& (I_FREEING
|I_CLEAR
|I_WILL_FREE
)) {
514 __wait_on_freeing_inode(inode
);
519 return node
? inode
: NULL
;
523 * find_inode_fast is the fast path version of find_inode, see the comment at
524 * iget_locked for details.
526 static struct inode
* find_inode_fast(struct super_block
* sb
, struct hlist_head
*head
, unsigned long ino
)
528 struct hlist_node
*node
;
529 struct inode
* inode
= NULL
;
532 hlist_for_each (node
, head
) {
533 inode
= hlist_entry(node
, struct inode
, i_hash
);
534 if (inode
->i_ino
!= ino
)
536 if (inode
->i_sb
!= sb
)
538 if (inode
->i_state
& (I_FREEING
|I_CLEAR
|I_WILL_FREE
)) {
539 __wait_on_freeing_inode(inode
);
544 return node
? inode
: NULL
;
548 * new_inode - obtain an inode
551 * Allocates a new inode for given superblock.
553 struct inode
*new_inode(struct super_block
*sb
)
555 static unsigned long last_ino
;
556 struct inode
* inode
;
558 spin_lock_prefetch(&inode_lock
);
560 inode
= alloc_inode(sb
);
562 spin_lock(&inode_lock
);
563 inodes_stat
.nr_inodes
++;
564 list_add(&inode
->i_list
, &inode_in_use
);
565 list_add(&inode
->i_sb_list
, &sb
->s_inodes
);
566 inode
->i_ino
= ++last_ino
;
568 spin_unlock(&inode_lock
);
573 EXPORT_SYMBOL(new_inode
);
575 void unlock_new_inode(struct inode
*inode
)
578 * This is special! We do not need the spinlock
579 * when clearing I_LOCK, because we're guaranteed
580 * that nobody else tries to do anything about the
581 * state of the inode when it is locked, as we
582 * just created it (so there can be no old holders
583 * that haven't tested I_LOCK).
585 inode
->i_state
&= ~(I_LOCK
|I_NEW
);
586 wake_up_inode(inode
);
589 EXPORT_SYMBOL(unlock_new_inode
);
592 * This is called without the inode lock held.. Be careful.
594 * We no longer cache the sb_flags in i_flags - see fs.h
595 * -- rmk@arm.uk.linux.org
597 static struct inode
* get_new_inode(struct super_block
*sb
, struct hlist_head
*head
, int (*test
)(struct inode
*, void *), int (*set
)(struct inode
*, void *), void *data
)
599 struct inode
* inode
;
601 inode
= alloc_inode(sb
);
605 spin_lock(&inode_lock
);
606 /* We released the lock, so.. */
607 old
= find_inode(sb
, head
, test
, data
);
609 if (set(inode
, data
))
612 inodes_stat
.nr_inodes
++;
613 list_add(&inode
->i_list
, &inode_in_use
);
614 list_add(&inode
->i_sb_list
, &sb
->s_inodes
);
615 hlist_add_head(&inode
->i_hash
, head
);
616 inode
->i_state
= I_LOCK
|I_NEW
;
617 spin_unlock(&inode_lock
);
619 /* Return the locked inode with I_NEW set, the
620 * caller is responsible for filling in the contents
626 * Uhhuh, somebody else created the same inode under
627 * us. Use the old inode instead of the one we just
631 spin_unlock(&inode_lock
);
632 destroy_inode(inode
);
634 wait_on_inode(inode
);
639 spin_unlock(&inode_lock
);
640 destroy_inode(inode
);
645 * get_new_inode_fast is the fast path version of get_new_inode, see the
646 * comment at iget_locked for details.
648 static struct inode
* get_new_inode_fast(struct super_block
*sb
, struct hlist_head
*head
, unsigned long ino
)
650 struct inode
* inode
;
652 inode
= alloc_inode(sb
);
656 spin_lock(&inode_lock
);
657 /* We released the lock, so.. */
658 old
= find_inode_fast(sb
, head
, ino
);
661 inodes_stat
.nr_inodes
++;
662 list_add(&inode
->i_list
, &inode_in_use
);
663 list_add(&inode
->i_sb_list
, &sb
->s_inodes
);
664 hlist_add_head(&inode
->i_hash
, head
);
665 inode
->i_state
= I_LOCK
|I_NEW
;
666 spin_unlock(&inode_lock
);
668 /* Return the locked inode with I_NEW set, the
669 * caller is responsible for filling in the contents
675 * Uhhuh, somebody else created the same inode under
676 * us. Use the old inode instead of the one we just
680 spin_unlock(&inode_lock
);
681 destroy_inode(inode
);
683 wait_on_inode(inode
);
688 static inline unsigned long hash(struct super_block
*sb
, unsigned long hashval
)
692 tmp
= (hashval
* (unsigned long)sb
) ^ (GOLDEN_RATIO_PRIME
+ hashval
) /
694 tmp
= tmp
^ ((tmp
^ GOLDEN_RATIO_PRIME
) >> I_HASHBITS
);
695 return tmp
& I_HASHMASK
;
699 * iunique - get a unique inode number
701 * @max_reserved: highest reserved inode number
703 * Obtain an inode number that is unique on the system for a given
704 * superblock. This is used by file systems that have no natural
705 * permanent inode numbering system. An inode number is returned that
706 * is higher than the reserved limit but unique.
709 * With a large number of inodes live on the file system this function
710 * currently becomes quite slow.
712 ino_t
iunique(struct super_block
*sb
, ino_t max_reserved
)
714 static ino_t counter
;
716 struct hlist_head
* head
;
718 spin_lock(&inode_lock
);
720 if (counter
> max_reserved
) {
721 head
= inode_hashtable
+ hash(sb
,counter
);
723 inode
= find_inode_fast(sb
, head
, res
);
725 spin_unlock(&inode_lock
);
729 counter
= max_reserved
+ 1;
735 EXPORT_SYMBOL(iunique
);
737 struct inode
*igrab(struct inode
*inode
)
739 spin_lock(&inode_lock
);
740 if (!(inode
->i_state
& (I_FREEING
|I_WILL_FREE
)))
744 * Handle the case where s_op->clear_inode is not been
745 * called yet, and somebody is calling igrab
746 * while the inode is getting freed.
749 spin_unlock(&inode_lock
);
753 EXPORT_SYMBOL(igrab
);
756 * ifind - internal function, you want ilookup5() or iget5().
757 * @sb: super block of file system to search
758 * @head: the head of the list to search
759 * @test: callback used for comparisons between inodes
760 * @data: opaque data pointer to pass to @test
761 * @wait: if true wait for the inode to be unlocked, if false do not
763 * ifind() searches for the inode specified by @data in the inode
764 * cache. This is a generalized version of ifind_fast() for file systems where
765 * the inode number is not sufficient for unique identification of an inode.
767 * If the inode is in the cache, the inode is returned with an incremented
770 * Otherwise NULL is returned.
772 * Note, @test is called with the inode_lock held, so can't sleep.
774 static struct inode
*ifind(struct super_block
*sb
,
775 struct hlist_head
*head
, int (*test
)(struct inode
*, void *),
776 void *data
, const int wait
)
780 spin_lock(&inode_lock
);
781 inode
= find_inode(sb
, head
, test
, data
);
784 spin_unlock(&inode_lock
);
786 wait_on_inode(inode
);
789 spin_unlock(&inode_lock
);
794 * ifind_fast - internal function, you want ilookup() or iget().
795 * @sb: super block of file system to search
796 * @head: head of the list to search
797 * @ino: inode number to search for
799 * ifind_fast() searches for the inode @ino in the inode cache. This is for
800 * file systems where the inode number is sufficient for unique identification
803 * If the inode is in the cache, the inode is returned with an incremented
806 * Otherwise NULL is returned.
808 static struct inode
*ifind_fast(struct super_block
*sb
,
809 struct hlist_head
*head
, unsigned long ino
)
813 spin_lock(&inode_lock
);
814 inode
= find_inode_fast(sb
, head
, ino
);
817 spin_unlock(&inode_lock
);
818 wait_on_inode(inode
);
821 spin_unlock(&inode_lock
);
826 * ilookup5_nowait - search for an inode in the inode cache
827 * @sb: super block of file system to search
828 * @hashval: hash value (usually inode number) to search for
829 * @test: callback used for comparisons between inodes
830 * @data: opaque data pointer to pass to @test
832 * ilookup5() uses ifind() to search for the inode specified by @hashval and
833 * @data in the inode cache. This is a generalized version of ilookup() for
834 * file systems where the inode number is not sufficient for unique
835 * identification of an inode.
837 * If the inode is in the cache, the inode is returned with an incremented
838 * reference count. Note, the inode lock is not waited upon so you have to be
839 * very careful what you do with the returned inode. You probably should be
840 * using ilookup5() instead.
842 * Otherwise NULL is returned.
844 * Note, @test is called with the inode_lock held, so can't sleep.
846 struct inode
*ilookup5_nowait(struct super_block
*sb
, unsigned long hashval
,
847 int (*test
)(struct inode
*, void *), void *data
)
849 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
851 return ifind(sb
, head
, test
, data
, 0);
854 EXPORT_SYMBOL(ilookup5_nowait
);
857 * ilookup5 - search for an inode in the inode cache
858 * @sb: super block of file system to search
859 * @hashval: hash value (usually inode number) to search for
860 * @test: callback used for comparisons between inodes
861 * @data: opaque data pointer to pass to @test
863 * ilookup5() uses ifind() to search for the inode specified by @hashval and
864 * @data in the inode cache. This is a generalized version of ilookup() for
865 * file systems where the inode number is not sufficient for unique
866 * identification of an inode.
868 * If the inode is in the cache, the inode lock is waited upon and the inode is
869 * returned with an incremented reference count.
871 * Otherwise NULL is returned.
873 * Note, @test is called with the inode_lock held, so can't sleep.
875 struct inode
*ilookup5(struct super_block
*sb
, unsigned long hashval
,
876 int (*test
)(struct inode
*, void *), void *data
)
878 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
880 return ifind(sb
, head
, test
, data
, 1);
883 EXPORT_SYMBOL(ilookup5
);
886 * ilookup - search for an inode in the inode cache
887 * @sb: super block of file system to search
888 * @ino: inode number to search for
890 * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache.
891 * This is for file systems where the inode number is sufficient for unique
892 * identification of an inode.
894 * If the inode is in the cache, the inode is returned with an incremented
897 * Otherwise NULL is returned.
899 struct inode
*ilookup(struct super_block
*sb
, unsigned long ino
)
901 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
903 return ifind_fast(sb
, head
, ino
);
906 EXPORT_SYMBOL(ilookup
);
909 * iget5_locked - obtain an inode from a mounted file system
910 * @sb: super block of file system
911 * @hashval: hash value (usually inode number) to get
912 * @test: callback used for comparisons between inodes
913 * @set: callback used to initialize a new struct inode
914 * @data: opaque data pointer to pass to @test and @set
916 * This is iget() without the read_inode() portion of get_new_inode().
918 * iget5_locked() uses ifind() to search for the inode specified by @hashval
919 * and @data in the inode cache and if present it is returned with an increased
920 * reference count. This is a generalized version of iget_locked() for file
921 * systems where the inode number is not sufficient for unique identification
924 * If the inode is not in cache, get_new_inode() is called to allocate a new
925 * inode and this is returned locked, hashed, and with the I_NEW flag set. The
926 * file system gets to fill it in before unlocking it via unlock_new_inode().
928 * Note both @test and @set are called with the inode_lock held, so can't sleep.
930 struct inode
*iget5_locked(struct super_block
*sb
, unsigned long hashval
,
931 int (*test
)(struct inode
*, void *),
932 int (*set
)(struct inode
*, void *), void *data
)
934 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
937 inode
= ifind(sb
, head
, test
, data
, 1);
941 * get_new_inode() will do the right thing, re-trying the search
942 * in case it had to block at any point.
944 return get_new_inode(sb
, head
, test
, set
, data
);
947 EXPORT_SYMBOL(iget5_locked
);
950 * iget_locked - obtain an inode from a mounted file system
951 * @sb: super block of file system
952 * @ino: inode number to get
954 * This is iget() without the read_inode() portion of get_new_inode_fast().
956 * iget_locked() uses ifind_fast() to search for the inode specified by @ino in
957 * the inode cache and if present it is returned with an increased reference
958 * count. This is for file systems where the inode number is sufficient for
959 * unique identification of an inode.
961 * If the inode is not in cache, get_new_inode_fast() is called to allocate a
962 * new inode and this is returned locked, hashed, and with the I_NEW flag set.
963 * The file system gets to fill it in before unlocking it via
964 * unlock_new_inode().
966 struct inode
*iget_locked(struct super_block
*sb
, unsigned long ino
)
968 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
971 inode
= ifind_fast(sb
, head
, ino
);
975 * get_new_inode_fast() will do the right thing, re-trying the search
976 * in case it had to block at any point.
978 return get_new_inode_fast(sb
, head
, ino
);
981 EXPORT_SYMBOL(iget_locked
);
984 * __insert_inode_hash - hash an inode
985 * @inode: unhashed inode
986 * @hashval: unsigned long value used to locate this object in the
989 * Add an inode to the inode hash for this superblock.
991 void __insert_inode_hash(struct inode
*inode
, unsigned long hashval
)
993 struct hlist_head
*head
= inode_hashtable
+ hash(inode
->i_sb
, hashval
);
994 spin_lock(&inode_lock
);
995 hlist_add_head(&inode
->i_hash
, head
);
996 spin_unlock(&inode_lock
);
999 EXPORT_SYMBOL(__insert_inode_hash
);
1002 * remove_inode_hash - remove an inode from the hash
1003 * @inode: inode to unhash
1005 * Remove an inode from the superblock.
1007 void remove_inode_hash(struct inode
*inode
)
1009 spin_lock(&inode_lock
);
1010 hlist_del_init(&inode
->i_hash
);
1011 spin_unlock(&inode_lock
);
1014 EXPORT_SYMBOL(remove_inode_hash
);
1017 * Tell the filesystem that this inode is no longer of any interest and should
1018 * be completely destroyed.
1020 * We leave the inode in the inode hash table until *after* the filesystem's
1021 * ->delete_inode completes. This ensures that an iget (such as nfsd might
1022 * instigate) will always find up-to-date information either in the hash or on
1025 * I_FREEING is set so that no-one will take a new reference to the inode while
1026 * it is being deleted.
1028 void generic_delete_inode(struct inode
*inode
)
1030 struct super_operations
*op
= inode
->i_sb
->s_op
;
1032 list_del_init(&inode
->i_list
);
1033 list_del_init(&inode
->i_sb_list
);
1034 inode
->i_state
|=I_FREEING
;
1035 inodes_stat
.nr_inodes
--;
1036 spin_unlock(&inode_lock
);
1038 security_inode_delete(inode
);
1040 if (op
->delete_inode
) {
1041 void (*delete)(struct inode
*) = op
->delete_inode
;
1042 if (!is_bad_inode(inode
))
1044 /* Filesystems implementing their own
1045 * s_op->delete_inode are required to call
1046 * truncate_inode_pages and clear_inode()
1050 truncate_inode_pages(&inode
->i_data
, 0);
1053 spin_lock(&inode_lock
);
1054 hlist_del_init(&inode
->i_hash
);
1055 spin_unlock(&inode_lock
);
1056 wake_up_inode(inode
);
1057 if (inode
->i_state
!= I_CLEAR
)
1059 destroy_inode(inode
);
1062 EXPORT_SYMBOL(generic_delete_inode
);
1064 static void generic_forget_inode(struct inode
*inode
)
1066 struct super_block
*sb
= inode
->i_sb
;
1068 if (!hlist_unhashed(&inode
->i_hash
)) {
1069 if (!(inode
->i_state
& (I_DIRTY
|I_LOCK
)))
1070 list_move(&inode
->i_list
, &inode_unused
);
1071 inodes_stat
.nr_unused
++;
1072 if (!sb
|| (sb
->s_flags
& MS_ACTIVE
)) {
1073 spin_unlock(&inode_lock
);
1076 inode
->i_state
|= I_WILL_FREE
;
1077 spin_unlock(&inode_lock
);
1078 write_inode_now(inode
, 1);
1079 spin_lock(&inode_lock
);
1080 inode
->i_state
&= ~I_WILL_FREE
;
1081 inodes_stat
.nr_unused
--;
1082 hlist_del_init(&inode
->i_hash
);
1084 list_del_init(&inode
->i_list
);
1085 list_del_init(&inode
->i_sb_list
);
1086 inode
->i_state
|= I_FREEING
;
1087 inodes_stat
.nr_inodes
--;
1088 spin_unlock(&inode_lock
);
1089 if (inode
->i_data
.nrpages
)
1090 truncate_inode_pages(&inode
->i_data
, 0);
1092 wake_up_inode(inode
);
1093 destroy_inode(inode
);
1097 * Normal UNIX filesystem behaviour: delete the
1098 * inode when the usage count drops to zero, and
1101 void generic_drop_inode(struct inode
*inode
)
1103 if (!inode
->i_nlink
)
1104 generic_delete_inode(inode
);
1106 generic_forget_inode(inode
);
1109 EXPORT_SYMBOL_GPL(generic_drop_inode
);
1112 * Called when we're dropping the last reference
1115 * Call the FS "drop()" function, defaulting to
1116 * the legacy UNIX filesystem behaviour..
1118 * NOTE! NOTE! NOTE! We're called with the inode lock
1119 * held, and the drop function is supposed to release
1122 static inline void iput_final(struct inode
*inode
)
1124 struct super_operations
*op
= inode
->i_sb
->s_op
;
1125 void (*drop
)(struct inode
*) = generic_drop_inode
;
1127 if (op
&& op
->drop_inode
)
1128 drop
= op
->drop_inode
;
1133 * iput - put an inode
1134 * @inode: inode to put
1136 * Puts an inode, dropping its usage count. If the inode use count hits
1137 * zero, the inode is then freed and may also be destroyed.
1139 * Consequently, iput() can sleep.
1141 void iput(struct inode
*inode
)
1144 struct super_operations
*op
= inode
->i_sb
->s_op
;
1146 BUG_ON(inode
->i_state
== I_CLEAR
);
1148 if (op
&& op
->put_inode
)
1149 op
->put_inode(inode
);
1151 if (atomic_dec_and_lock(&inode
->i_count
, &inode_lock
))
1156 EXPORT_SYMBOL(iput
);
1159 * bmap - find a block number in a file
1160 * @inode: inode of file
1161 * @block: block to find
1163 * Returns the block number on the device holding the inode that
1164 * is the disk block number for the block of the file requested.
1165 * That is, asked for block 4 of inode 1 the function will return the
1166 * disk block relative to the disk start that holds that block of the
1169 sector_t
bmap(struct inode
* inode
, sector_t block
)
1172 if (inode
->i_mapping
->a_ops
->bmap
)
1173 res
= inode
->i_mapping
->a_ops
->bmap(inode
->i_mapping
, block
);
1177 EXPORT_SYMBOL(bmap
);
1180 * touch_atime - update the access time
1181 * @mnt: mount the inode is accessed on
1182 * @dentry: dentry accessed
1184 * Update the accessed time on an inode and mark it for writeback.
1185 * This function automatically handles read only file systems and media,
1186 * as well as the "noatime" flag and inode specific "noatime" markers.
1188 void touch_atime(struct vfsmount
*mnt
, struct dentry
*dentry
)
1190 struct inode
*inode
= dentry
->d_inode
;
1191 struct timespec now
;
1193 if (IS_RDONLY(inode
))
1196 if ((inode
->i_flags
& S_NOATIME
) ||
1197 (inode
->i_sb
->s_flags
& MS_NOATIME
) ||
1198 ((inode
->i_sb
->s_flags
& MS_NODIRATIME
) && S_ISDIR(inode
->i_mode
)))
1202 * We may have a NULL vfsmount when coming from NFSD
1205 ((mnt
->mnt_flags
& MNT_NOATIME
) ||
1206 ((mnt
->mnt_flags
& MNT_NODIRATIME
) && S_ISDIR(inode
->i_mode
))))
1209 now
= current_fs_time(inode
->i_sb
);
1210 if (!timespec_equal(&inode
->i_atime
, &now
)) {
1211 inode
->i_atime
= now
;
1212 mark_inode_dirty_sync(inode
);
1216 EXPORT_SYMBOL(touch_atime
);
1219 * file_update_time - update mtime and ctime time
1220 * @file: file accessed
1222 * Update the mtime and ctime members of an inode and mark the inode
1223 * for writeback. Note that this function is meant exclusively for
1224 * usage in the file write path of filesystems, and filesystems may
1225 * choose to explicitly ignore update via this function with the
1226 * S_NOCTIME inode flag, e.g. for network filesystem where these
1227 * timestamps are handled by the server.
1230 void file_update_time(struct file
*file
)
1232 struct inode
*inode
= file
->f_dentry
->d_inode
;
1233 struct timespec now
;
1236 if (IS_NOCMTIME(inode
))
1238 if (IS_RDONLY(inode
))
1241 now
= current_fs_time(inode
->i_sb
);
1242 if (!timespec_equal(&inode
->i_mtime
, &now
))
1244 inode
->i_mtime
= now
;
1246 if (!timespec_equal(&inode
->i_ctime
, &now
))
1248 inode
->i_ctime
= now
;
1251 mark_inode_dirty_sync(inode
);
1254 EXPORT_SYMBOL(file_update_time
);
1256 int inode_needs_sync(struct inode
*inode
)
1260 if (S_ISDIR(inode
->i_mode
) && IS_DIRSYNC(inode
))
1265 EXPORT_SYMBOL(inode_needs_sync
);
1268 * Quota functions that want to walk the inode lists..
1272 /* Function back in dquot.c */
1273 int remove_inode_dquot_ref(struct inode
*, int, struct list_head
*);
1275 void remove_dquot_ref(struct super_block
*sb
, int type
,
1276 struct list_head
*tofree_head
)
1278 struct inode
*inode
;
1281 return; /* nothing to do */
1282 spin_lock(&inode_lock
); /* This lock is for inodes code */
1285 * We don't have to lock against quota code - test IS_QUOTAINIT is
1286 * just for speedup...
1288 list_for_each_entry(inode
, &sb
->s_inodes
, i_sb_list
)
1289 if (!IS_NOQUOTA(inode
))
1290 remove_inode_dquot_ref(inode
, type
, tofree_head
);
1292 spin_unlock(&inode_lock
);
1297 int inode_wait(void *word
)
1304 * If we try to find an inode in the inode hash while it is being
1305 * deleted, we have to wait until the filesystem completes its
1306 * deletion before reporting that it isn't found. This function waits
1307 * until the deletion _might_ have completed. Callers are responsible
1308 * to recheck inode state.
1310 * It doesn't matter if I_LOCK is not set initially, a call to
1311 * wake_up_inode() after removing from the hash list will DTRT.
1313 * This is called with inode_lock held.
1315 static void __wait_on_freeing_inode(struct inode
*inode
)
1317 wait_queue_head_t
*wq
;
1318 DEFINE_WAIT_BIT(wait
, &inode
->i_state
, __I_LOCK
);
1319 wq
= bit_waitqueue(&inode
->i_state
, __I_LOCK
);
1320 prepare_to_wait(wq
, &wait
.wait
, TASK_UNINTERRUPTIBLE
);
1321 spin_unlock(&inode_lock
);
1323 finish_wait(wq
, &wait
.wait
);
1324 spin_lock(&inode_lock
);
1327 void wake_up_inode(struct inode
*inode
)
1330 * Prevent speculative execution through spin_unlock(&inode_lock);
1333 wake_up_bit(&inode
->i_state
, __I_LOCK
);
1336 static __initdata
unsigned long ihash_entries
;
1337 static int __init
set_ihash_entries(char *str
)
1341 ihash_entries
= simple_strtoul(str
, &str
, 0);
1344 __setup("ihash_entries=", set_ihash_entries
);
1347 * Initialize the waitqueues and inode hash table.
1349 void __init
inode_init_early(void)
1353 /* If hashes are distributed across NUMA nodes, defer
1354 * hash allocation until vmalloc space is available.
1360 alloc_large_system_hash("Inode-cache",
1361 sizeof(struct hlist_head
),
1369 for (loop
= 0; loop
< (1 << i_hash_shift
); loop
++)
1370 INIT_HLIST_HEAD(&inode_hashtable
[loop
]);
1373 void __init
inode_init(unsigned long mempages
)
1377 /* inode slab cache */
1378 inode_cachep
= kmem_cache_create("inode_cache",
1379 sizeof(struct inode
),
1381 (SLAB_RECLAIM_ACCOUNT
|SLAB_PANIC
|
1385 set_shrinker(DEFAULT_SEEKS
, shrink_icache_memory
);
1387 /* Hash may have been set up in inode_init_early */
1392 alloc_large_system_hash("Inode-cache",
1393 sizeof(struct hlist_head
),
1401 for (loop
= 0; loop
< (1 << i_hash_shift
); loop
++)
1402 INIT_HLIST_HEAD(&inode_hashtable
[loop
]);
1405 void init_special_inode(struct inode
*inode
, umode_t mode
, dev_t rdev
)
1407 inode
->i_mode
= mode
;
1408 if (S_ISCHR(mode
)) {
1409 inode
->i_fop
= &def_chr_fops
;
1410 inode
->i_rdev
= rdev
;
1411 } else if (S_ISBLK(mode
)) {
1412 inode
->i_fop
= &def_blk_fops
;
1413 inode
->i_rdev
= rdev
;
1414 } else if (S_ISFIFO(mode
))
1415 inode
->i_fop
= &def_fifo_fops
;
1416 else if (S_ISSOCK(mode
))
1417 inode
->i_fop
= &bad_sock_fops
;
1419 printk(KERN_DEBUG
"init_special_inode: bogus i_mode (%o)\n",
1422 EXPORT_SYMBOL(init_special_inode
);