1 // SPDX-License-Identifier: GPL-2.0-only
3 * (C) 1997 Linus Torvalds
4 * (C) 1999 Andrea Arcangeli <andrea@suse.de> (dynamic inode allocation)
6 #include <linux/export.h>
9 #include <linux/backing-dev.h>
10 #include <linux/hash.h>
11 #include <linux/swap.h>
12 #include <linux/security.h>
13 #include <linux/cdev.h>
14 #include <linux/memblock.h>
15 #include <linux/fscrypt.h>
16 #include <linux/fsnotify.h>
17 #include <linux/mount.h>
18 #include <linux/posix_acl.h>
19 #include <linux/prefetch.h>
20 #include <linux/buffer_head.h> /* for inode_has_buffers */
21 #include <linux/ratelimit.h>
22 #include <linux/list_lru.h>
23 #include <linux/iversion.h>
24 #include <trace/events/writeback.h>
28 * Inode locking rules:
30 * inode->i_lock protects:
31 * inode->i_state, inode->i_hash, __iget()
32 * Inode LRU list locks protect:
33 * inode->i_sb->s_inode_lru, inode->i_lru
34 * inode->i_sb->s_inode_list_lock protects:
35 * inode->i_sb->s_inodes, inode->i_sb_list
36 * bdi->wb.list_lock protects:
37 * bdi->wb.b_{dirty,io,more_io,dirty_time}, inode->i_io_list
38 * inode_hash_lock protects:
39 * inode_hashtable, inode->i_hash
43 * inode->i_sb->s_inode_list_lock
45 * Inode LRU list locks
51 * inode->i_sb->s_inode_list_lock
58 static unsigned int i_hash_mask __read_mostly
;
59 static unsigned int i_hash_shift __read_mostly
;
60 static struct hlist_head
*inode_hashtable __read_mostly
;
61 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(inode_hash_lock
);
64 * Empty aops. Can be used for the cases where the user does not
65 * define any of the address_space operations.
67 const struct address_space_operations empty_aops
= {
69 EXPORT_SYMBOL(empty_aops
);
72 * Statistics gathering..
74 struct inodes_stat_t inodes_stat
;
76 static DEFINE_PER_CPU(unsigned long, nr_inodes
);
77 static DEFINE_PER_CPU(unsigned long, nr_unused
);
79 static struct kmem_cache
*inode_cachep __read_mostly
;
81 static long get_nr_inodes(void)
85 for_each_possible_cpu(i
)
86 sum
+= per_cpu(nr_inodes
, i
);
87 return sum
< 0 ? 0 : sum
;
90 static inline long get_nr_inodes_unused(void)
94 for_each_possible_cpu(i
)
95 sum
+= per_cpu(nr_unused
, i
);
96 return sum
< 0 ? 0 : sum
;
99 long get_nr_dirty_inodes(void)
101 /* not actually dirty inodes, but a wild approximation */
102 long nr_dirty
= get_nr_inodes() - get_nr_inodes_unused();
103 return nr_dirty
> 0 ? nr_dirty
: 0;
107 * Handle nr_inode sysctl
110 int proc_nr_inodes(struct ctl_table
*table
, int write
,
111 void *buffer
, size_t *lenp
, loff_t
*ppos
)
113 inodes_stat
.nr_inodes
= get_nr_inodes();
114 inodes_stat
.nr_unused
= get_nr_inodes_unused();
115 return proc_doulongvec_minmax(table
, write
, buffer
, lenp
, ppos
);
119 static int no_open(struct inode
*inode
, struct file
*file
)
125 * inode_init_always - perform inode structure initialisation
126 * @sb: superblock inode belongs to
127 * @inode: inode to initialise
129 * These are initializations that need to be done on every inode
130 * allocation as the fields are not initialised by slab allocation.
132 int inode_init_always(struct super_block
*sb
, struct inode
*inode
)
134 static const struct inode_operations empty_iops
;
135 static const struct file_operations no_open_fops
= {.open
= no_open
};
136 struct address_space
*const mapping
= &inode
->i_data
;
139 inode
->i_blkbits
= sb
->s_blocksize_bits
;
141 atomic64_set(&inode
->i_sequence
, 0);
142 atomic_set(&inode
->i_count
, 1);
143 inode
->i_op
= &empty_iops
;
144 inode
->i_fop
= &no_open_fops
;
145 inode
->__i_nlink
= 1;
146 inode
->i_opflags
= 0;
148 inode
->i_opflags
|= IOP_XATTR
;
149 i_uid_write(inode
, 0);
150 i_gid_write(inode
, 0);
151 atomic_set(&inode
->i_writecount
, 0);
153 inode
->i_write_hint
= WRITE_LIFE_NOT_SET
;
156 inode
->i_generation
= 0;
157 inode
->i_pipe
= NULL
;
158 inode
->i_bdev
= NULL
;
159 inode
->i_cdev
= NULL
;
160 inode
->i_link
= NULL
;
161 inode
->i_dir_seq
= 0;
163 inode
->dirtied_when
= 0;
165 #ifdef CONFIG_CGROUP_WRITEBACK
166 inode
->i_wb_frn_winner
= 0;
167 inode
->i_wb_frn_avg_time
= 0;
168 inode
->i_wb_frn_history
= 0;
171 if (security_inode_alloc(inode
))
173 spin_lock_init(&inode
->i_lock
);
174 lockdep_set_class(&inode
->i_lock
, &sb
->s_type
->i_lock_key
);
176 init_rwsem(&inode
->i_rwsem
);
177 lockdep_set_class(&inode
->i_rwsem
, &sb
->s_type
->i_mutex_key
);
179 atomic_set(&inode
->i_dio_count
, 0);
181 mapping
->a_ops
= &empty_aops
;
182 mapping
->host
= inode
;
184 if (sb
->s_type
->fs_flags
& FS_THP_SUPPORT
)
185 __set_bit(AS_THP_SUPPORT
, &mapping
->flags
);
187 atomic_set(&mapping
->i_mmap_writable
, 0);
188 #ifdef CONFIG_READ_ONLY_THP_FOR_FS
189 atomic_set(&mapping
->nr_thps
, 0);
191 mapping_set_gfp_mask(mapping
, GFP_HIGHUSER_MOVABLE
);
192 mapping
->private_data
= NULL
;
193 mapping
->writeback_index
= 0;
194 inode
->i_private
= NULL
;
195 inode
->i_mapping
= mapping
;
196 INIT_HLIST_HEAD(&inode
->i_dentry
); /* buggered by rcu freeing */
197 #ifdef CONFIG_FS_POSIX_ACL
198 inode
->i_acl
= inode
->i_default_acl
= ACL_NOT_CACHED
;
201 #ifdef CONFIG_FSNOTIFY
202 inode
->i_fsnotify_mask
= 0;
204 inode
->i_flctx
= NULL
;
205 this_cpu_inc(nr_inodes
);
211 EXPORT_SYMBOL(inode_init_always
);
213 void free_inode_nonrcu(struct inode
*inode
)
215 kmem_cache_free(inode_cachep
, inode
);
217 EXPORT_SYMBOL(free_inode_nonrcu
);
219 static void i_callback(struct rcu_head
*head
)
221 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
222 if (inode
->free_inode
)
223 inode
->free_inode(inode
);
225 free_inode_nonrcu(inode
);
228 static struct inode
*alloc_inode(struct super_block
*sb
)
230 const struct super_operations
*ops
= sb
->s_op
;
233 if (ops
->alloc_inode
)
234 inode
= ops
->alloc_inode(sb
);
236 inode
= kmem_cache_alloc(inode_cachep
, GFP_KERNEL
);
241 if (unlikely(inode_init_always(sb
, inode
))) {
242 if (ops
->destroy_inode
) {
243 ops
->destroy_inode(inode
);
244 if (!ops
->free_inode
)
247 inode
->free_inode
= ops
->free_inode
;
248 i_callback(&inode
->i_rcu
);
255 void __destroy_inode(struct inode
*inode
)
257 BUG_ON(inode_has_buffers(inode
));
258 inode_detach_wb(inode
);
259 security_inode_free(inode
);
260 fsnotify_inode_delete(inode
);
261 locks_free_lock_context(inode
);
262 if (!inode
->i_nlink
) {
263 WARN_ON(atomic_long_read(&inode
->i_sb
->s_remove_count
) == 0);
264 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
267 #ifdef CONFIG_FS_POSIX_ACL
268 if (inode
->i_acl
&& !is_uncached_acl(inode
->i_acl
))
269 posix_acl_release(inode
->i_acl
);
270 if (inode
->i_default_acl
&& !is_uncached_acl(inode
->i_default_acl
))
271 posix_acl_release(inode
->i_default_acl
);
273 this_cpu_dec(nr_inodes
);
275 EXPORT_SYMBOL(__destroy_inode
);
277 static void destroy_inode(struct inode
*inode
)
279 const struct super_operations
*ops
= inode
->i_sb
->s_op
;
281 BUG_ON(!list_empty(&inode
->i_lru
));
282 __destroy_inode(inode
);
283 if (ops
->destroy_inode
) {
284 ops
->destroy_inode(inode
);
285 if (!ops
->free_inode
)
288 inode
->free_inode
= ops
->free_inode
;
289 call_rcu(&inode
->i_rcu
, i_callback
);
293 * drop_nlink - directly drop an inode's link count
296 * This is a low-level filesystem helper to replace any
297 * direct filesystem manipulation of i_nlink. In cases
298 * where we are attempting to track writes to the
299 * filesystem, a decrement to zero means an imminent
300 * write when the file is truncated and actually unlinked
303 void drop_nlink(struct inode
*inode
)
305 WARN_ON(inode
->i_nlink
== 0);
308 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
310 EXPORT_SYMBOL(drop_nlink
);
313 * clear_nlink - directly zero an inode's link count
316 * This is a low-level filesystem helper to replace any
317 * direct filesystem manipulation of i_nlink. See
318 * drop_nlink() for why we care about i_nlink hitting zero.
320 void clear_nlink(struct inode
*inode
)
322 if (inode
->i_nlink
) {
323 inode
->__i_nlink
= 0;
324 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
327 EXPORT_SYMBOL(clear_nlink
);
330 * set_nlink - directly set an inode's link count
332 * @nlink: new nlink (should be non-zero)
334 * This is a low-level filesystem helper to replace any
335 * direct filesystem manipulation of i_nlink.
337 void set_nlink(struct inode
*inode
, unsigned int nlink
)
342 /* Yes, some filesystems do change nlink from zero to one */
343 if (inode
->i_nlink
== 0)
344 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
346 inode
->__i_nlink
= nlink
;
349 EXPORT_SYMBOL(set_nlink
);
352 * inc_nlink - directly increment an inode's link count
355 * This is a low-level filesystem helper to replace any
356 * direct filesystem manipulation of i_nlink. Currently,
357 * it is only here for parity with dec_nlink().
359 void inc_nlink(struct inode
*inode
)
361 if (unlikely(inode
->i_nlink
== 0)) {
362 WARN_ON(!(inode
->i_state
& I_LINKABLE
));
363 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
368 EXPORT_SYMBOL(inc_nlink
);
370 static void __address_space_init_once(struct address_space
*mapping
)
372 xa_init_flags(&mapping
->i_pages
, XA_FLAGS_LOCK_IRQ
| XA_FLAGS_ACCOUNT
);
373 init_rwsem(&mapping
->i_mmap_rwsem
);
374 INIT_LIST_HEAD(&mapping
->private_list
);
375 spin_lock_init(&mapping
->private_lock
);
376 mapping
->i_mmap
= RB_ROOT_CACHED
;
379 void address_space_init_once(struct address_space
*mapping
)
381 memset(mapping
, 0, sizeof(*mapping
));
382 __address_space_init_once(mapping
);
384 EXPORT_SYMBOL(address_space_init_once
);
387 * These are initializations that only need to be done
388 * once, because the fields are idempotent across use
389 * of the inode, so let the slab aware of that.
391 void inode_init_once(struct inode
*inode
)
393 memset(inode
, 0, sizeof(*inode
));
394 INIT_HLIST_NODE(&inode
->i_hash
);
395 INIT_LIST_HEAD(&inode
->i_devices
);
396 INIT_LIST_HEAD(&inode
->i_io_list
);
397 INIT_LIST_HEAD(&inode
->i_wb_list
);
398 INIT_LIST_HEAD(&inode
->i_lru
);
399 __address_space_init_once(&inode
->i_data
);
400 i_size_ordered_init(inode
);
402 EXPORT_SYMBOL(inode_init_once
);
404 static void init_once(void *foo
)
406 struct inode
*inode
= (struct inode
*) foo
;
408 inode_init_once(inode
);
412 * inode->i_lock must be held
414 void __iget(struct inode
*inode
)
416 atomic_inc(&inode
->i_count
);
420 * get additional reference to inode; caller must already hold one.
422 void ihold(struct inode
*inode
)
424 WARN_ON(atomic_inc_return(&inode
->i_count
) < 2);
426 EXPORT_SYMBOL(ihold
);
428 static void inode_lru_list_add(struct inode
*inode
)
430 if (list_lru_add(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
431 this_cpu_inc(nr_unused
);
433 inode
->i_state
|= I_REFERENCED
;
437 * Add inode to LRU if needed (inode is unused and clean).
439 * Needs inode->i_lock held.
441 void inode_add_lru(struct inode
*inode
)
443 if (!(inode
->i_state
& (I_DIRTY_ALL
| I_SYNC
|
444 I_FREEING
| I_WILL_FREE
)) &&
445 !atomic_read(&inode
->i_count
) && inode
->i_sb
->s_flags
& SB_ACTIVE
)
446 inode_lru_list_add(inode
);
450 static void inode_lru_list_del(struct inode
*inode
)
453 if (list_lru_del(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
454 this_cpu_dec(nr_unused
);
458 * inode_sb_list_add - add inode to the superblock list of inodes
459 * @inode: inode to add
461 void inode_sb_list_add(struct inode
*inode
)
463 spin_lock(&inode
->i_sb
->s_inode_list_lock
);
464 list_add(&inode
->i_sb_list
, &inode
->i_sb
->s_inodes
);
465 spin_unlock(&inode
->i_sb
->s_inode_list_lock
);
467 EXPORT_SYMBOL_GPL(inode_sb_list_add
);
469 static inline void inode_sb_list_del(struct inode
*inode
)
471 if (!list_empty(&inode
->i_sb_list
)) {
472 spin_lock(&inode
->i_sb
->s_inode_list_lock
);
473 list_del_init(&inode
->i_sb_list
);
474 spin_unlock(&inode
->i_sb
->s_inode_list_lock
);
478 static unsigned long hash(struct super_block
*sb
, unsigned long hashval
)
482 tmp
= (hashval
* (unsigned long)sb
) ^ (GOLDEN_RATIO_PRIME
+ hashval
) /
484 tmp
= tmp
^ ((tmp
^ GOLDEN_RATIO_PRIME
) >> i_hash_shift
);
485 return tmp
& i_hash_mask
;
489 * __insert_inode_hash - hash an inode
490 * @inode: unhashed inode
491 * @hashval: unsigned long value used to locate this object in the
494 * Add an inode to the inode hash for this superblock.
496 void __insert_inode_hash(struct inode
*inode
, unsigned long hashval
)
498 struct hlist_head
*b
= inode_hashtable
+ hash(inode
->i_sb
, hashval
);
500 spin_lock(&inode_hash_lock
);
501 spin_lock(&inode
->i_lock
);
502 hlist_add_head_rcu(&inode
->i_hash
, b
);
503 spin_unlock(&inode
->i_lock
);
504 spin_unlock(&inode_hash_lock
);
506 EXPORT_SYMBOL(__insert_inode_hash
);
509 * __remove_inode_hash - remove an inode from the hash
510 * @inode: inode to unhash
512 * Remove an inode from the superblock.
514 void __remove_inode_hash(struct inode
*inode
)
516 spin_lock(&inode_hash_lock
);
517 spin_lock(&inode
->i_lock
);
518 hlist_del_init_rcu(&inode
->i_hash
);
519 spin_unlock(&inode
->i_lock
);
520 spin_unlock(&inode_hash_lock
);
522 EXPORT_SYMBOL(__remove_inode_hash
);
524 void clear_inode(struct inode
*inode
)
527 * We have to cycle the i_pages lock here because reclaim can be in the
528 * process of removing the last page (in __delete_from_page_cache())
529 * and we must not free the mapping under it.
531 xa_lock_irq(&inode
->i_data
.i_pages
);
532 BUG_ON(inode
->i_data
.nrpages
);
533 BUG_ON(inode
->i_data
.nrexceptional
);
534 xa_unlock_irq(&inode
->i_data
.i_pages
);
535 BUG_ON(!list_empty(&inode
->i_data
.private_list
));
536 BUG_ON(!(inode
->i_state
& I_FREEING
));
537 BUG_ON(inode
->i_state
& I_CLEAR
);
538 BUG_ON(!list_empty(&inode
->i_wb_list
));
539 /* don't need i_lock here, no concurrent mods to i_state */
540 inode
->i_state
= I_FREEING
| I_CLEAR
;
542 EXPORT_SYMBOL(clear_inode
);
545 * Free the inode passed in, removing it from the lists it is still connected
546 * to. We remove any pages still attached to the inode and wait for any IO that
547 * is still in progress before finally destroying the inode.
549 * An inode must already be marked I_FREEING so that we avoid the inode being
550 * moved back onto lists if we race with other code that manipulates the lists
551 * (e.g. writeback_single_inode). The caller is responsible for setting this.
553 * An inode must already be removed from the LRU list before being evicted from
554 * the cache. This should occur atomically with setting the I_FREEING state
555 * flag, so no inodes here should ever be on the LRU when being evicted.
557 static void evict(struct inode
*inode
)
559 const struct super_operations
*op
= inode
->i_sb
->s_op
;
561 BUG_ON(!(inode
->i_state
& I_FREEING
));
562 BUG_ON(!list_empty(&inode
->i_lru
));
564 if (!list_empty(&inode
->i_io_list
))
565 inode_io_list_del(inode
);
567 inode_sb_list_del(inode
);
570 * Wait for flusher thread to be done with the inode so that filesystem
571 * does not start destroying it while writeback is still running. Since
572 * the inode has I_FREEING set, flusher thread won't start new work on
573 * the inode. We just have to wait for running writeback to finish.
575 inode_wait_for_writeback(inode
);
577 if (op
->evict_inode
) {
578 op
->evict_inode(inode
);
580 truncate_inode_pages_final(&inode
->i_data
);
583 if (S_ISBLK(inode
->i_mode
) && inode
->i_bdev
)
585 if (S_ISCHR(inode
->i_mode
) && inode
->i_cdev
)
588 remove_inode_hash(inode
);
590 spin_lock(&inode
->i_lock
);
591 wake_up_bit(&inode
->i_state
, __I_NEW
);
592 BUG_ON(inode
->i_state
!= (I_FREEING
| I_CLEAR
));
593 spin_unlock(&inode
->i_lock
);
595 destroy_inode(inode
);
599 * dispose_list - dispose of the contents of a local list
600 * @head: the head of the list to free
602 * Dispose-list gets a local list with local inodes in it, so it doesn't
603 * need to worry about list corruption and SMP locks.
605 static void dispose_list(struct list_head
*head
)
607 while (!list_empty(head
)) {
610 inode
= list_first_entry(head
, struct inode
, i_lru
);
611 list_del_init(&inode
->i_lru
);
619 * evict_inodes - evict all evictable inodes for a superblock
620 * @sb: superblock to operate on
622 * Make sure that no inodes with zero refcount are retained. This is
623 * called by superblock shutdown after having SB_ACTIVE flag removed,
624 * so any inode reaching zero refcount during or after that call will
625 * be immediately evicted.
627 void evict_inodes(struct super_block
*sb
)
629 struct inode
*inode
, *next
;
633 spin_lock(&sb
->s_inode_list_lock
);
634 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
635 if (atomic_read(&inode
->i_count
))
638 spin_lock(&inode
->i_lock
);
639 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
640 spin_unlock(&inode
->i_lock
);
644 inode
->i_state
|= I_FREEING
;
645 inode_lru_list_del(inode
);
646 spin_unlock(&inode
->i_lock
);
647 list_add(&inode
->i_lru
, &dispose
);
650 * We can have a ton of inodes to evict at unmount time given
651 * enough memory, check to see if we need to go to sleep for a
652 * bit so we don't livelock.
654 if (need_resched()) {
655 spin_unlock(&sb
->s_inode_list_lock
);
657 dispose_list(&dispose
);
661 spin_unlock(&sb
->s_inode_list_lock
);
663 dispose_list(&dispose
);
665 EXPORT_SYMBOL_GPL(evict_inodes
);
668 * invalidate_inodes - attempt to free all inodes on a superblock
669 * @sb: superblock to operate on
670 * @kill_dirty: flag to guide handling of dirty inodes
672 * Attempts to free all inodes for a given superblock. If there were any
673 * busy inodes return a non-zero value, else zero.
674 * If @kill_dirty is set, discard dirty inodes too, otherwise treat
677 int invalidate_inodes(struct super_block
*sb
, bool kill_dirty
)
680 struct inode
*inode
, *next
;
684 spin_lock(&sb
->s_inode_list_lock
);
685 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
686 spin_lock(&inode
->i_lock
);
687 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
688 spin_unlock(&inode
->i_lock
);
691 if (inode
->i_state
& I_DIRTY_ALL
&& !kill_dirty
) {
692 spin_unlock(&inode
->i_lock
);
696 if (atomic_read(&inode
->i_count
)) {
697 spin_unlock(&inode
->i_lock
);
702 inode
->i_state
|= I_FREEING
;
703 inode_lru_list_del(inode
);
704 spin_unlock(&inode
->i_lock
);
705 list_add(&inode
->i_lru
, &dispose
);
706 if (need_resched()) {
707 spin_unlock(&sb
->s_inode_list_lock
);
709 dispose_list(&dispose
);
713 spin_unlock(&sb
->s_inode_list_lock
);
715 dispose_list(&dispose
);
721 * Isolate the inode from the LRU in preparation for freeing it.
723 * Any inodes which are pinned purely because of attached pagecache have their
724 * pagecache removed. If the inode has metadata buffers attached to
725 * mapping->private_list then try to remove them.
727 * If the inode has the I_REFERENCED flag set, then it means that it has been
728 * used recently - the flag is set in iput_final(). When we encounter such an
729 * inode, clear the flag and move it to the back of the LRU so it gets another
730 * pass through the LRU before it gets reclaimed. This is necessary because of
731 * the fact we are doing lazy LRU updates to minimise lock contention so the
732 * LRU does not have strict ordering. Hence we don't want to reclaim inodes
733 * with this flag set because they are the inodes that are out of order.
735 static enum lru_status
inode_lru_isolate(struct list_head
*item
,
736 struct list_lru_one
*lru
, spinlock_t
*lru_lock
, void *arg
)
738 struct list_head
*freeable
= arg
;
739 struct inode
*inode
= container_of(item
, struct inode
, i_lru
);
742 * we are inverting the lru lock/inode->i_lock here, so use a trylock.
743 * If we fail to get the lock, just skip it.
745 if (!spin_trylock(&inode
->i_lock
))
749 * Referenced or dirty inodes are still in use. Give them another pass
750 * through the LRU as we canot reclaim them now.
752 if (atomic_read(&inode
->i_count
) ||
753 (inode
->i_state
& ~I_REFERENCED
)) {
754 list_lru_isolate(lru
, &inode
->i_lru
);
755 spin_unlock(&inode
->i_lock
);
756 this_cpu_dec(nr_unused
);
760 /* recently referenced inodes get one more pass */
761 if (inode
->i_state
& I_REFERENCED
) {
762 inode
->i_state
&= ~I_REFERENCED
;
763 spin_unlock(&inode
->i_lock
);
767 if (inode_has_buffers(inode
) || inode
->i_data
.nrpages
) {
769 spin_unlock(&inode
->i_lock
);
770 spin_unlock(lru_lock
);
771 if (remove_inode_buffers(inode
)) {
773 reap
= invalidate_mapping_pages(&inode
->i_data
, 0, -1);
774 if (current_is_kswapd())
775 __count_vm_events(KSWAPD_INODESTEAL
, reap
);
777 __count_vm_events(PGINODESTEAL
, reap
);
778 if (current
->reclaim_state
)
779 current
->reclaim_state
->reclaimed_slab
+= reap
;
786 WARN_ON(inode
->i_state
& I_NEW
);
787 inode
->i_state
|= I_FREEING
;
788 list_lru_isolate_move(lru
, &inode
->i_lru
, freeable
);
789 spin_unlock(&inode
->i_lock
);
791 this_cpu_dec(nr_unused
);
796 * Walk the superblock inode LRU for freeable inodes and attempt to free them.
797 * This is called from the superblock shrinker function with a number of inodes
798 * to trim from the LRU. Inodes to be freed are moved to a temporary list and
799 * then are freed outside inode_lock by dispose_list().
801 long prune_icache_sb(struct super_block
*sb
, struct shrink_control
*sc
)
806 freed
= list_lru_shrink_walk(&sb
->s_inode_lru
, sc
,
807 inode_lru_isolate
, &freeable
);
808 dispose_list(&freeable
);
812 static void __wait_on_freeing_inode(struct inode
*inode
);
814 * Called with the inode lock held.
816 static struct inode
*find_inode(struct super_block
*sb
,
817 struct hlist_head
*head
,
818 int (*test
)(struct inode
*, void *),
821 struct inode
*inode
= NULL
;
824 hlist_for_each_entry(inode
, head
, i_hash
) {
825 if (inode
->i_sb
!= sb
)
827 if (!test(inode
, data
))
829 spin_lock(&inode
->i_lock
);
830 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
831 __wait_on_freeing_inode(inode
);
834 if (unlikely(inode
->i_state
& I_CREATING
)) {
835 spin_unlock(&inode
->i_lock
);
836 return ERR_PTR(-ESTALE
);
839 spin_unlock(&inode
->i_lock
);
846 * find_inode_fast is the fast path version of find_inode, see the comment at
847 * iget_locked for details.
849 static struct inode
*find_inode_fast(struct super_block
*sb
,
850 struct hlist_head
*head
, unsigned long ino
)
852 struct inode
*inode
= NULL
;
855 hlist_for_each_entry(inode
, head
, i_hash
) {
856 if (inode
->i_ino
!= ino
)
858 if (inode
->i_sb
!= sb
)
860 spin_lock(&inode
->i_lock
);
861 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
862 __wait_on_freeing_inode(inode
);
865 if (unlikely(inode
->i_state
& I_CREATING
)) {
866 spin_unlock(&inode
->i_lock
);
867 return ERR_PTR(-ESTALE
);
870 spin_unlock(&inode
->i_lock
);
877 * Each cpu owns a range of LAST_INO_BATCH numbers.
878 * 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations,
879 * to renew the exhausted range.
881 * This does not significantly increase overflow rate because every CPU can
882 * consume at most LAST_INO_BATCH-1 unused inode numbers. So there is
883 * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the
884 * 2^32 range, and is a worst-case. Even a 50% wastage would only increase
885 * overflow rate by 2x, which does not seem too significant.
887 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
888 * error if st_ino won't fit in target struct field. Use 32bit counter
889 * here to attempt to avoid that.
891 #define LAST_INO_BATCH 1024
892 static DEFINE_PER_CPU(unsigned int, last_ino
);
894 unsigned int get_next_ino(void)
896 unsigned int *p
= &get_cpu_var(last_ino
);
897 unsigned int res
= *p
;
900 if (unlikely((res
& (LAST_INO_BATCH
-1)) == 0)) {
901 static atomic_t shared_last_ino
;
902 int next
= atomic_add_return(LAST_INO_BATCH
, &shared_last_ino
);
904 res
= next
- LAST_INO_BATCH
;
909 /* get_next_ino should not provide a 0 inode number */
913 put_cpu_var(last_ino
);
916 EXPORT_SYMBOL(get_next_ino
);
919 * new_inode_pseudo - obtain an inode
922 * Allocates a new inode for given superblock.
923 * Inode wont be chained in superblock s_inodes list
925 * - fs can't be unmount
926 * - quotas, fsnotify, writeback can't work
928 struct inode
*new_inode_pseudo(struct super_block
*sb
)
930 struct inode
*inode
= alloc_inode(sb
);
933 spin_lock(&inode
->i_lock
);
935 spin_unlock(&inode
->i_lock
);
936 INIT_LIST_HEAD(&inode
->i_sb_list
);
942 * new_inode - obtain an inode
945 * Allocates a new inode for given superblock. The default gfp_mask
946 * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE.
947 * If HIGHMEM pages are unsuitable or it is known that pages allocated
948 * for the page cache are not reclaimable or migratable,
949 * mapping_set_gfp_mask() must be called with suitable flags on the
950 * newly created inode's mapping
953 struct inode
*new_inode(struct super_block
*sb
)
957 spin_lock_prefetch(&sb
->s_inode_list_lock
);
959 inode
= new_inode_pseudo(sb
);
961 inode_sb_list_add(inode
);
964 EXPORT_SYMBOL(new_inode
);
966 #ifdef CONFIG_DEBUG_LOCK_ALLOC
967 void lockdep_annotate_inode_mutex_key(struct inode
*inode
)
969 if (S_ISDIR(inode
->i_mode
)) {
970 struct file_system_type
*type
= inode
->i_sb
->s_type
;
972 /* Set new key only if filesystem hasn't already changed it */
973 if (lockdep_match_class(&inode
->i_rwsem
, &type
->i_mutex_key
)) {
975 * ensure nobody is actually holding i_mutex
977 // mutex_destroy(&inode->i_mutex);
978 init_rwsem(&inode
->i_rwsem
);
979 lockdep_set_class(&inode
->i_rwsem
,
980 &type
->i_mutex_dir_key
);
984 EXPORT_SYMBOL(lockdep_annotate_inode_mutex_key
);
988 * unlock_new_inode - clear the I_NEW state and wake up any waiters
989 * @inode: new inode to unlock
991 * Called when the inode is fully initialised to clear the new state of the
992 * inode and wake up anyone waiting for the inode to finish initialisation.
994 void unlock_new_inode(struct inode
*inode
)
996 lockdep_annotate_inode_mutex_key(inode
);
997 spin_lock(&inode
->i_lock
);
998 WARN_ON(!(inode
->i_state
& I_NEW
));
999 inode
->i_state
&= ~I_NEW
& ~I_CREATING
;
1001 wake_up_bit(&inode
->i_state
, __I_NEW
);
1002 spin_unlock(&inode
->i_lock
);
1004 EXPORT_SYMBOL(unlock_new_inode
);
1006 void discard_new_inode(struct inode
*inode
)
1008 lockdep_annotate_inode_mutex_key(inode
);
1009 spin_lock(&inode
->i_lock
);
1010 WARN_ON(!(inode
->i_state
& I_NEW
));
1011 inode
->i_state
&= ~I_NEW
;
1013 wake_up_bit(&inode
->i_state
, __I_NEW
);
1014 spin_unlock(&inode
->i_lock
);
1017 EXPORT_SYMBOL(discard_new_inode
);
1020 * lock_two_nondirectories - take two i_mutexes on non-directory objects
1022 * Lock any non-NULL argument that is not a directory.
1023 * Zero, one or two objects may be locked by this function.
1025 * @inode1: first inode to lock
1026 * @inode2: second inode to lock
1028 void lock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
1030 if (inode1
> inode2
)
1031 swap(inode1
, inode2
);
1033 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
1035 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
1036 inode_lock_nested(inode2
, I_MUTEX_NONDIR2
);
1038 EXPORT_SYMBOL(lock_two_nondirectories
);
1041 * unlock_two_nondirectories - release locks from lock_two_nondirectories()
1042 * @inode1: first inode to unlock
1043 * @inode2: second inode to unlock
1045 void unlock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
1047 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
1048 inode_unlock(inode1
);
1049 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
1050 inode_unlock(inode2
);
1052 EXPORT_SYMBOL(unlock_two_nondirectories
);
1055 * inode_insert5 - obtain an inode from a mounted file system
1056 * @inode: pre-allocated inode to use for insert to cache
1057 * @hashval: hash value (usually inode number) to get
1058 * @test: callback used for comparisons between inodes
1059 * @set: callback used to initialize a new struct inode
1060 * @data: opaque data pointer to pass to @test and @set
1062 * Search for the inode specified by @hashval and @data in the inode cache,
1063 * and if present it is return it with an increased reference count. This is
1064 * a variant of iget5_locked() for callers that don't want to fail on memory
1065 * allocation of inode.
1067 * If the inode is not in cache, insert the pre-allocated inode to cache and
1068 * return it locked, hashed, and with the I_NEW flag set. The file system gets
1069 * to fill it in before unlocking it via unlock_new_inode().
1071 * Note both @test and @set are called with the inode_hash_lock held, so can't
1074 struct inode
*inode_insert5(struct inode
*inode
, unsigned long hashval
,
1075 int (*test
)(struct inode
*, void *),
1076 int (*set
)(struct inode
*, void *), void *data
)
1078 struct hlist_head
*head
= inode_hashtable
+ hash(inode
->i_sb
, hashval
);
1080 bool creating
= inode
->i_state
& I_CREATING
;
1083 spin_lock(&inode_hash_lock
);
1084 old
= find_inode(inode
->i_sb
, head
, test
, data
);
1085 if (unlikely(old
)) {
1087 * Uhhuh, somebody else created the same inode under us.
1088 * Use the old inode instead of the preallocated one.
1090 spin_unlock(&inode_hash_lock
);
1094 if (unlikely(inode_unhashed(old
))) {
1101 if (set
&& unlikely(set(inode
, data
))) {
1107 * Return the locked inode with I_NEW set, the
1108 * caller is responsible for filling in the contents
1110 spin_lock(&inode
->i_lock
);
1111 inode
->i_state
|= I_NEW
;
1112 hlist_add_head_rcu(&inode
->i_hash
, head
);
1113 spin_unlock(&inode
->i_lock
);
1115 inode_sb_list_add(inode
);
1117 spin_unlock(&inode_hash_lock
);
1121 EXPORT_SYMBOL(inode_insert5
);
1124 * iget5_locked - obtain an inode from a mounted file system
1125 * @sb: super block of file system
1126 * @hashval: hash value (usually inode number) to get
1127 * @test: callback used for comparisons between inodes
1128 * @set: callback used to initialize a new struct inode
1129 * @data: opaque data pointer to pass to @test and @set
1131 * Search for the inode specified by @hashval and @data in the inode cache,
1132 * and if present it is return it with an increased reference count. This is
1133 * a generalized version of iget_locked() for file systems where the inode
1134 * number is not sufficient for unique identification of an inode.
1136 * If the inode is not in cache, allocate a new inode and return it locked,
1137 * hashed, and with the I_NEW flag set. The file system gets to fill it in
1138 * before unlocking it via unlock_new_inode().
1140 * Note both @test and @set are called with the inode_hash_lock held, so can't
1143 struct inode
*iget5_locked(struct super_block
*sb
, unsigned long hashval
,
1144 int (*test
)(struct inode
*, void *),
1145 int (*set
)(struct inode
*, void *), void *data
)
1147 struct inode
*inode
= ilookup5(sb
, hashval
, test
, data
);
1150 struct inode
*new = alloc_inode(sb
);
1154 inode
= inode_insert5(new, hashval
, test
, set
, data
);
1155 if (unlikely(inode
!= new))
1161 EXPORT_SYMBOL(iget5_locked
);
1164 * iget_locked - obtain an inode from a mounted file system
1165 * @sb: super block of file system
1166 * @ino: inode number to get
1168 * Search for the inode specified by @ino in the inode cache and if present
1169 * return it with an increased reference count. This is for file systems
1170 * where the inode number is sufficient for unique identification of an inode.
1172 * If the inode is not in cache, allocate a new inode and return it locked,
1173 * hashed, and with the I_NEW flag set. The file system gets to fill it in
1174 * before unlocking it via unlock_new_inode().
1176 struct inode
*iget_locked(struct super_block
*sb
, unsigned long ino
)
1178 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1179 struct inode
*inode
;
1181 spin_lock(&inode_hash_lock
);
1182 inode
= find_inode_fast(sb
, head
, ino
);
1183 spin_unlock(&inode_hash_lock
);
1187 wait_on_inode(inode
);
1188 if (unlikely(inode_unhashed(inode
))) {
1195 inode
= alloc_inode(sb
);
1199 spin_lock(&inode_hash_lock
);
1200 /* We released the lock, so.. */
1201 old
= find_inode_fast(sb
, head
, ino
);
1204 spin_lock(&inode
->i_lock
);
1205 inode
->i_state
= I_NEW
;
1206 hlist_add_head_rcu(&inode
->i_hash
, head
);
1207 spin_unlock(&inode
->i_lock
);
1208 inode_sb_list_add(inode
);
1209 spin_unlock(&inode_hash_lock
);
1211 /* Return the locked inode with I_NEW set, the
1212 * caller is responsible for filling in the contents
1218 * Uhhuh, somebody else created the same inode under
1219 * us. Use the old inode instead of the one we just
1222 spin_unlock(&inode_hash_lock
);
1223 destroy_inode(inode
);
1227 wait_on_inode(inode
);
1228 if (unlikely(inode_unhashed(inode
))) {
1235 EXPORT_SYMBOL(iget_locked
);
1238 * search the inode cache for a matching inode number.
1239 * If we find one, then the inode number we are trying to
1240 * allocate is not unique and so we should not use it.
1242 * Returns 1 if the inode number is unique, 0 if it is not.
1244 static int test_inode_iunique(struct super_block
*sb
, unsigned long ino
)
1246 struct hlist_head
*b
= inode_hashtable
+ hash(sb
, ino
);
1247 struct inode
*inode
;
1249 hlist_for_each_entry_rcu(inode
, b
, i_hash
) {
1250 if (inode
->i_ino
== ino
&& inode
->i_sb
== sb
)
1257 * iunique - get a unique inode number
1259 * @max_reserved: highest reserved inode number
1261 * Obtain an inode number that is unique on the system for a given
1262 * superblock. This is used by file systems that have no natural
1263 * permanent inode numbering system. An inode number is returned that
1264 * is higher than the reserved limit but unique.
1267 * With a large number of inodes live on the file system this function
1268 * currently becomes quite slow.
1270 ino_t
iunique(struct super_block
*sb
, ino_t max_reserved
)
1273 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
1274 * error if st_ino won't fit in target struct field. Use 32bit counter
1275 * here to attempt to avoid that.
1277 static DEFINE_SPINLOCK(iunique_lock
);
1278 static unsigned int counter
;
1282 spin_lock(&iunique_lock
);
1284 if (counter
<= max_reserved
)
1285 counter
= max_reserved
+ 1;
1287 } while (!test_inode_iunique(sb
, res
));
1288 spin_unlock(&iunique_lock
);
1293 EXPORT_SYMBOL(iunique
);
1295 struct inode
*igrab(struct inode
*inode
)
1297 spin_lock(&inode
->i_lock
);
1298 if (!(inode
->i_state
& (I_FREEING
|I_WILL_FREE
))) {
1300 spin_unlock(&inode
->i_lock
);
1302 spin_unlock(&inode
->i_lock
);
1304 * Handle the case where s_op->clear_inode is not been
1305 * called yet, and somebody is calling igrab
1306 * while the inode is getting freed.
1312 EXPORT_SYMBOL(igrab
);
1315 * ilookup5_nowait - search for an inode in the inode cache
1316 * @sb: super block of file system to search
1317 * @hashval: hash value (usually inode number) to search for
1318 * @test: callback used for comparisons between inodes
1319 * @data: opaque data pointer to pass to @test
1321 * Search for the inode specified by @hashval and @data in the inode cache.
1322 * If the inode is in the cache, the inode is returned with an incremented
1325 * Note: I_NEW is not waited upon so you have to be very careful what you do
1326 * with the returned inode. You probably should be using ilookup5() instead.
1328 * Note2: @test is called with the inode_hash_lock held, so can't sleep.
1330 struct inode
*ilookup5_nowait(struct super_block
*sb
, unsigned long hashval
,
1331 int (*test
)(struct inode
*, void *), void *data
)
1333 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1334 struct inode
*inode
;
1336 spin_lock(&inode_hash_lock
);
1337 inode
= find_inode(sb
, head
, test
, data
);
1338 spin_unlock(&inode_hash_lock
);
1340 return IS_ERR(inode
) ? NULL
: inode
;
1342 EXPORT_SYMBOL(ilookup5_nowait
);
1345 * ilookup5 - search for an inode in the inode cache
1346 * @sb: super block of file system to search
1347 * @hashval: hash value (usually inode number) to search for
1348 * @test: callback used for comparisons between inodes
1349 * @data: opaque data pointer to pass to @test
1351 * Search for the inode specified by @hashval and @data in the inode cache,
1352 * and if the inode is in the cache, return the inode with an incremented
1353 * reference count. Waits on I_NEW before returning the inode.
1354 * returned with an incremented reference count.
1356 * This is a generalized version of ilookup() for file systems where the
1357 * inode number is not sufficient for unique identification of an inode.
1359 * Note: @test is called with the inode_hash_lock held, so can't sleep.
1361 struct inode
*ilookup5(struct super_block
*sb
, unsigned long hashval
,
1362 int (*test
)(struct inode
*, void *), void *data
)
1364 struct inode
*inode
;
1366 inode
= ilookup5_nowait(sb
, hashval
, test
, data
);
1368 wait_on_inode(inode
);
1369 if (unlikely(inode_unhashed(inode
))) {
1376 EXPORT_SYMBOL(ilookup5
);
1379 * ilookup - search for an inode in the inode cache
1380 * @sb: super block of file system to search
1381 * @ino: inode number to search for
1383 * Search for the inode @ino in the inode cache, and if the inode is in the
1384 * cache, the inode is returned with an incremented reference count.
1386 struct inode
*ilookup(struct super_block
*sb
, unsigned long ino
)
1388 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1389 struct inode
*inode
;
1391 spin_lock(&inode_hash_lock
);
1392 inode
= find_inode_fast(sb
, head
, ino
);
1393 spin_unlock(&inode_hash_lock
);
1398 wait_on_inode(inode
);
1399 if (unlikely(inode_unhashed(inode
))) {
1406 EXPORT_SYMBOL(ilookup
);
1409 * find_inode_nowait - find an inode in the inode cache
1410 * @sb: super block of file system to search
1411 * @hashval: hash value (usually inode number) to search for
1412 * @match: callback used for comparisons between inodes
1413 * @data: opaque data pointer to pass to @match
1415 * Search for the inode specified by @hashval and @data in the inode
1416 * cache, where the helper function @match will return 0 if the inode
1417 * does not match, 1 if the inode does match, and -1 if the search
1418 * should be stopped. The @match function must be responsible for
1419 * taking the i_lock spin_lock and checking i_state for an inode being
1420 * freed or being initialized, and incrementing the reference count
1421 * before returning 1. It also must not sleep, since it is called with
1422 * the inode_hash_lock spinlock held.
1424 * This is a even more generalized version of ilookup5() when the
1425 * function must never block --- find_inode() can block in
1426 * __wait_on_freeing_inode() --- or when the caller can not increment
1427 * the reference count because the resulting iput() might cause an
1428 * inode eviction. The tradeoff is that the @match funtion must be
1429 * very carefully implemented.
1431 struct inode
*find_inode_nowait(struct super_block
*sb
,
1432 unsigned long hashval
,
1433 int (*match
)(struct inode
*, unsigned long,
1437 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1438 struct inode
*inode
, *ret_inode
= NULL
;
1441 spin_lock(&inode_hash_lock
);
1442 hlist_for_each_entry(inode
, head
, i_hash
) {
1443 if (inode
->i_sb
!= sb
)
1445 mval
= match(inode
, hashval
, data
);
1453 spin_unlock(&inode_hash_lock
);
1456 EXPORT_SYMBOL(find_inode_nowait
);
1459 * find_inode_rcu - find an inode in the inode cache
1460 * @sb: Super block of file system to search
1461 * @hashval: Key to hash
1462 * @test: Function to test match on an inode
1463 * @data: Data for test function
1465 * Search for the inode specified by @hashval and @data in the inode cache,
1466 * where the helper function @test will return 0 if the inode does not match
1467 * and 1 if it does. The @test function must be responsible for taking the
1468 * i_lock spin_lock and checking i_state for an inode being freed or being
1471 * If successful, this will return the inode for which the @test function
1472 * returned 1 and NULL otherwise.
1474 * The @test function is not permitted to take a ref on any inode presented.
1475 * It is also not permitted to sleep.
1477 * The caller must hold the RCU read lock.
1479 struct inode
*find_inode_rcu(struct super_block
*sb
, unsigned long hashval
,
1480 int (*test
)(struct inode
*, void *), void *data
)
1482 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1483 struct inode
*inode
;
1485 RCU_LOCKDEP_WARN(!rcu_read_lock_held(),
1486 "suspicious find_inode_rcu() usage");
1488 hlist_for_each_entry_rcu(inode
, head
, i_hash
) {
1489 if (inode
->i_sb
== sb
&&
1490 !(READ_ONCE(inode
->i_state
) & (I_FREEING
| I_WILL_FREE
)) &&
1496 EXPORT_SYMBOL(find_inode_rcu
);
1499 * find_inode_by_rcu - Find an inode in the inode cache
1500 * @sb: Super block of file system to search
1501 * @ino: The inode number to match
1503 * Search for the inode specified by @hashval and @data in the inode cache,
1504 * where the helper function @test will return 0 if the inode does not match
1505 * and 1 if it does. The @test function must be responsible for taking the
1506 * i_lock spin_lock and checking i_state for an inode being freed or being
1509 * If successful, this will return the inode for which the @test function
1510 * returned 1 and NULL otherwise.
1512 * The @test function is not permitted to take a ref on any inode presented.
1513 * It is also not permitted to sleep.
1515 * The caller must hold the RCU read lock.
1517 struct inode
*find_inode_by_ino_rcu(struct super_block
*sb
,
1520 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1521 struct inode
*inode
;
1523 RCU_LOCKDEP_WARN(!rcu_read_lock_held(),
1524 "suspicious find_inode_by_ino_rcu() usage");
1526 hlist_for_each_entry_rcu(inode
, head
, i_hash
) {
1527 if (inode
->i_ino
== ino
&&
1528 inode
->i_sb
== sb
&&
1529 !(READ_ONCE(inode
->i_state
) & (I_FREEING
| I_WILL_FREE
)))
1534 EXPORT_SYMBOL(find_inode_by_ino_rcu
);
1536 int insert_inode_locked(struct inode
*inode
)
1538 struct super_block
*sb
= inode
->i_sb
;
1539 ino_t ino
= inode
->i_ino
;
1540 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1543 struct inode
*old
= NULL
;
1544 spin_lock(&inode_hash_lock
);
1545 hlist_for_each_entry(old
, head
, i_hash
) {
1546 if (old
->i_ino
!= ino
)
1548 if (old
->i_sb
!= sb
)
1550 spin_lock(&old
->i_lock
);
1551 if (old
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
1552 spin_unlock(&old
->i_lock
);
1558 spin_lock(&inode
->i_lock
);
1559 inode
->i_state
|= I_NEW
| I_CREATING
;
1560 hlist_add_head_rcu(&inode
->i_hash
, head
);
1561 spin_unlock(&inode
->i_lock
);
1562 spin_unlock(&inode_hash_lock
);
1565 if (unlikely(old
->i_state
& I_CREATING
)) {
1566 spin_unlock(&old
->i_lock
);
1567 spin_unlock(&inode_hash_lock
);
1571 spin_unlock(&old
->i_lock
);
1572 spin_unlock(&inode_hash_lock
);
1574 if (unlikely(!inode_unhashed(old
))) {
1581 EXPORT_SYMBOL(insert_inode_locked
);
1583 int insert_inode_locked4(struct inode
*inode
, unsigned long hashval
,
1584 int (*test
)(struct inode
*, void *), void *data
)
1588 inode
->i_state
|= I_CREATING
;
1589 old
= inode_insert5(inode
, hashval
, test
, NULL
, data
);
1597 EXPORT_SYMBOL(insert_inode_locked4
);
1600 int generic_delete_inode(struct inode
*inode
)
1604 EXPORT_SYMBOL(generic_delete_inode
);
1607 * Called when we're dropping the last reference
1610 * Call the FS "drop_inode()" function, defaulting to
1611 * the legacy UNIX filesystem behaviour. If it tells
1612 * us to evict inode, do so. Otherwise, retain inode
1613 * in cache if fs is alive, sync and evict if fs is
1616 static void iput_final(struct inode
*inode
)
1618 struct super_block
*sb
= inode
->i_sb
;
1619 const struct super_operations
*op
= inode
->i_sb
->s_op
;
1620 unsigned long state
;
1623 WARN_ON(inode
->i_state
& I_NEW
);
1626 drop
= op
->drop_inode(inode
);
1628 drop
= generic_drop_inode(inode
);
1630 if (!drop
&& (sb
->s_flags
& SB_ACTIVE
)) {
1631 inode_add_lru(inode
);
1632 spin_unlock(&inode
->i_lock
);
1636 state
= inode
->i_state
;
1638 WRITE_ONCE(inode
->i_state
, state
| I_WILL_FREE
);
1639 spin_unlock(&inode
->i_lock
);
1641 write_inode_now(inode
, 1);
1643 spin_lock(&inode
->i_lock
);
1644 state
= inode
->i_state
;
1645 WARN_ON(state
& I_NEW
);
1646 state
&= ~I_WILL_FREE
;
1649 WRITE_ONCE(inode
->i_state
, state
| I_FREEING
);
1650 if (!list_empty(&inode
->i_lru
))
1651 inode_lru_list_del(inode
);
1652 spin_unlock(&inode
->i_lock
);
1658 * iput - put an inode
1659 * @inode: inode to put
1661 * Puts an inode, dropping its usage count. If the inode use count hits
1662 * zero, the inode is then freed and may also be destroyed.
1664 * Consequently, iput() can sleep.
1666 void iput(struct inode
*inode
)
1670 BUG_ON(inode
->i_state
& I_CLEAR
);
1672 if (atomic_dec_and_lock(&inode
->i_count
, &inode
->i_lock
)) {
1673 if (inode
->i_nlink
&& (inode
->i_state
& I_DIRTY_TIME
)) {
1674 atomic_inc(&inode
->i_count
);
1675 spin_unlock(&inode
->i_lock
);
1676 trace_writeback_lazytime_iput(inode
);
1677 mark_inode_dirty_sync(inode
);
1683 EXPORT_SYMBOL(iput
);
1687 * bmap - find a block number in a file
1688 * @inode: inode owning the block number being requested
1689 * @block: pointer containing the block to find
1691 * Replaces the value in ``*block`` with the block number on the device holding
1692 * corresponding to the requested block number in the file.
1693 * That is, asked for block 4 of inode 1 the function will replace the
1694 * 4 in ``*block``, with disk block relative to the disk start that holds that
1695 * block of the file.
1697 * Returns -EINVAL in case of error, 0 otherwise. If mapping falls into a
1698 * hole, returns 0 and ``*block`` is also set to 0.
1700 int bmap(struct inode
*inode
, sector_t
*block
)
1702 if (!inode
->i_mapping
->a_ops
->bmap
)
1705 *block
= inode
->i_mapping
->a_ops
->bmap(inode
->i_mapping
, *block
);
1708 EXPORT_SYMBOL(bmap
);
1712 * With relative atime, only update atime if the previous atime is
1713 * earlier than either the ctime or mtime or if at least a day has
1714 * passed since the last atime update.
1716 static int relatime_need_update(struct vfsmount
*mnt
, struct inode
*inode
,
1717 struct timespec64 now
)
1720 if (!(mnt
->mnt_flags
& MNT_RELATIME
))
1723 * Is mtime younger than atime? If yes, update atime:
1725 if (timespec64_compare(&inode
->i_mtime
, &inode
->i_atime
) >= 0)
1728 * Is ctime younger than atime? If yes, update atime:
1730 if (timespec64_compare(&inode
->i_ctime
, &inode
->i_atime
) >= 0)
1734 * Is the previous atime value older than a day? If yes,
1737 if ((long)(now
.tv_sec
- inode
->i_atime
.tv_sec
) >= 24*60*60)
1740 * Good, we can skip the atime update:
1745 int generic_update_time(struct inode
*inode
, struct timespec64
*time
, int flags
)
1747 int iflags
= I_DIRTY_TIME
;
1750 if (flags
& S_ATIME
)
1751 inode
->i_atime
= *time
;
1752 if (flags
& S_VERSION
)
1753 dirty
= inode_maybe_inc_iversion(inode
, false);
1754 if (flags
& S_CTIME
)
1755 inode
->i_ctime
= *time
;
1756 if (flags
& S_MTIME
)
1757 inode
->i_mtime
= *time
;
1758 if ((flags
& (S_ATIME
| S_CTIME
| S_MTIME
)) &&
1759 !(inode
->i_sb
->s_flags
& SB_LAZYTIME
))
1763 iflags
|= I_DIRTY_SYNC
;
1764 __mark_inode_dirty(inode
, iflags
);
1767 EXPORT_SYMBOL(generic_update_time
);
1770 * This does the actual work of updating an inodes time or version. Must have
1771 * had called mnt_want_write() before calling this.
1773 static int update_time(struct inode
*inode
, struct timespec64
*time
, int flags
)
1775 if (inode
->i_op
->update_time
)
1776 return inode
->i_op
->update_time(inode
, time
, flags
);
1777 return generic_update_time(inode
, time
, flags
);
1781 * touch_atime - update the access time
1782 * @path: the &struct path to update
1783 * @inode: inode to update
1785 * Update the accessed time on an inode and mark it for writeback.
1786 * This function automatically handles read only file systems and media,
1787 * as well as the "noatime" flag and inode specific "noatime" markers.
1789 bool atime_needs_update(const struct path
*path
, struct inode
*inode
)
1791 struct vfsmount
*mnt
= path
->mnt
;
1792 struct timespec64 now
;
1794 if (inode
->i_flags
& S_NOATIME
)
1797 /* Atime updates will likely cause i_uid and i_gid to be written
1798 * back improprely if their true value is unknown to the vfs.
1800 if (HAS_UNMAPPED_ID(inode
))
1803 if (IS_NOATIME(inode
))
1805 if ((inode
->i_sb
->s_flags
& SB_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1808 if (mnt
->mnt_flags
& MNT_NOATIME
)
1810 if ((mnt
->mnt_flags
& MNT_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1813 now
= current_time(inode
);
1815 if (!relatime_need_update(mnt
, inode
, now
))
1818 if (timespec64_equal(&inode
->i_atime
, &now
))
1824 void touch_atime(const struct path
*path
)
1826 struct vfsmount
*mnt
= path
->mnt
;
1827 struct inode
*inode
= d_inode(path
->dentry
);
1828 struct timespec64 now
;
1830 if (!atime_needs_update(path
, inode
))
1833 if (!sb_start_write_trylock(inode
->i_sb
))
1836 if (__mnt_want_write(mnt
) != 0)
1839 * File systems can error out when updating inodes if they need to
1840 * allocate new space to modify an inode (such is the case for
1841 * Btrfs), but since we touch atime while walking down the path we
1842 * really don't care if we failed to update the atime of the file,
1843 * so just ignore the return value.
1844 * We may also fail on filesystems that have the ability to make parts
1845 * of the fs read only, e.g. subvolumes in Btrfs.
1847 now
= current_time(inode
);
1848 update_time(inode
, &now
, S_ATIME
);
1849 __mnt_drop_write(mnt
);
1851 sb_end_write(inode
->i_sb
);
1853 EXPORT_SYMBOL(touch_atime
);
1856 * The logic we want is
1858 * if suid or (sgid and xgrp)
1861 int should_remove_suid(struct dentry
*dentry
)
1863 umode_t mode
= d_inode(dentry
)->i_mode
;
1866 /* suid always must be killed */
1867 if (unlikely(mode
& S_ISUID
))
1868 kill
= ATTR_KILL_SUID
;
1871 * sgid without any exec bits is just a mandatory locking mark; leave
1872 * it alone. If some exec bits are set, it's a real sgid; kill it.
1874 if (unlikely((mode
& S_ISGID
) && (mode
& S_IXGRP
)))
1875 kill
|= ATTR_KILL_SGID
;
1877 if (unlikely(kill
&& !capable(CAP_FSETID
) && S_ISREG(mode
)))
1882 EXPORT_SYMBOL(should_remove_suid
);
1885 * Return mask of changes for notify_change() that need to be done as a
1886 * response to write or truncate. Return 0 if nothing has to be changed.
1887 * Negative value on error (change should be denied).
1889 int dentry_needs_remove_privs(struct dentry
*dentry
)
1891 struct inode
*inode
= d_inode(dentry
);
1895 if (IS_NOSEC(inode
))
1898 mask
= should_remove_suid(dentry
);
1899 ret
= security_inode_need_killpriv(dentry
);
1903 mask
|= ATTR_KILL_PRIV
;
1907 static int __remove_privs(struct dentry
*dentry
, int kill
)
1909 struct iattr newattrs
;
1911 newattrs
.ia_valid
= ATTR_FORCE
| kill
;
1913 * Note we call this on write, so notify_change will not
1914 * encounter any conflicting delegations:
1916 return notify_change(dentry
, &newattrs
, NULL
);
1920 * Remove special file priviledges (suid, capabilities) when file is written
1923 int file_remove_privs(struct file
*file
)
1925 struct dentry
*dentry
= file_dentry(file
);
1926 struct inode
*inode
= file_inode(file
);
1931 * Fast path for nothing security related.
1932 * As well for non-regular files, e.g. blkdev inodes.
1933 * For example, blkdev_write_iter() might get here
1934 * trying to remove privs which it is not allowed to.
1936 if (IS_NOSEC(inode
) || !S_ISREG(inode
->i_mode
))
1939 kill
= dentry_needs_remove_privs(dentry
);
1943 error
= __remove_privs(dentry
, kill
);
1945 inode_has_no_xattr(inode
);
1949 EXPORT_SYMBOL(file_remove_privs
);
1952 * file_update_time - update mtime and ctime time
1953 * @file: file accessed
1955 * Update the mtime and ctime members of an inode and mark the inode
1956 * for writeback. Note that this function is meant exclusively for
1957 * usage in the file write path of filesystems, and filesystems may
1958 * choose to explicitly ignore update via this function with the
1959 * S_NOCMTIME inode flag, e.g. for network filesystem where these
1960 * timestamps are handled by the server. This can return an error for
1961 * file systems who need to allocate space in order to update an inode.
1964 int file_update_time(struct file
*file
)
1966 struct inode
*inode
= file_inode(file
);
1967 struct timespec64 now
;
1971 /* First try to exhaust all avenues to not sync */
1972 if (IS_NOCMTIME(inode
))
1975 now
= current_time(inode
);
1976 if (!timespec64_equal(&inode
->i_mtime
, &now
))
1979 if (!timespec64_equal(&inode
->i_ctime
, &now
))
1982 if (IS_I_VERSION(inode
) && inode_iversion_need_inc(inode
))
1983 sync_it
|= S_VERSION
;
1988 /* Finally allowed to write? Takes lock. */
1989 if (__mnt_want_write_file(file
))
1992 ret
= update_time(inode
, &now
, sync_it
);
1993 __mnt_drop_write_file(file
);
1997 EXPORT_SYMBOL(file_update_time
);
1999 /* Caller must hold the file's inode lock */
2000 int file_modified(struct file
*file
)
2005 * Clear the security bits if the process is not being run by root.
2006 * This keeps people from modifying setuid and setgid binaries.
2008 err
= file_remove_privs(file
);
2012 if (unlikely(file
->f_mode
& FMODE_NOCMTIME
))
2015 return file_update_time(file
);
2017 EXPORT_SYMBOL(file_modified
);
2019 int inode_needs_sync(struct inode
*inode
)
2023 if (S_ISDIR(inode
->i_mode
) && IS_DIRSYNC(inode
))
2027 EXPORT_SYMBOL(inode_needs_sync
);
2030 * If we try to find an inode in the inode hash while it is being
2031 * deleted, we have to wait until the filesystem completes its
2032 * deletion before reporting that it isn't found. This function waits
2033 * until the deletion _might_ have completed. Callers are responsible
2034 * to recheck inode state.
2036 * It doesn't matter if I_NEW is not set initially, a call to
2037 * wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list
2040 static void __wait_on_freeing_inode(struct inode
*inode
)
2042 wait_queue_head_t
*wq
;
2043 DEFINE_WAIT_BIT(wait
, &inode
->i_state
, __I_NEW
);
2044 wq
= bit_waitqueue(&inode
->i_state
, __I_NEW
);
2045 prepare_to_wait(wq
, &wait
.wq_entry
, TASK_UNINTERRUPTIBLE
);
2046 spin_unlock(&inode
->i_lock
);
2047 spin_unlock(&inode_hash_lock
);
2049 finish_wait(wq
, &wait
.wq_entry
);
2050 spin_lock(&inode_hash_lock
);
2053 static __initdata
unsigned long ihash_entries
;
2054 static int __init
set_ihash_entries(char *str
)
2058 ihash_entries
= simple_strtoul(str
, &str
, 0);
2061 __setup("ihash_entries=", set_ihash_entries
);
2064 * Initialize the waitqueues and inode hash table.
2066 void __init
inode_init_early(void)
2068 /* If hashes are distributed across NUMA nodes, defer
2069 * hash allocation until vmalloc space is available.
2075 alloc_large_system_hash("Inode-cache",
2076 sizeof(struct hlist_head
),
2079 HASH_EARLY
| HASH_ZERO
,
2086 void __init
inode_init(void)
2088 /* inode slab cache */
2089 inode_cachep
= kmem_cache_create("inode_cache",
2090 sizeof(struct inode
),
2092 (SLAB_RECLAIM_ACCOUNT
|SLAB_PANIC
|
2093 SLAB_MEM_SPREAD
|SLAB_ACCOUNT
),
2096 /* Hash may have been set up in inode_init_early */
2101 alloc_large_system_hash("Inode-cache",
2102 sizeof(struct hlist_head
),
2112 void init_special_inode(struct inode
*inode
, umode_t mode
, dev_t rdev
)
2114 inode
->i_mode
= mode
;
2115 if (S_ISCHR(mode
)) {
2116 inode
->i_fop
= &def_chr_fops
;
2117 inode
->i_rdev
= rdev
;
2118 } else if (S_ISBLK(mode
)) {
2119 inode
->i_fop
= &def_blk_fops
;
2120 inode
->i_rdev
= rdev
;
2121 } else if (S_ISFIFO(mode
))
2122 inode
->i_fop
= &pipefifo_fops
;
2123 else if (S_ISSOCK(mode
))
2124 ; /* leave it no_open_fops */
2126 printk(KERN_DEBUG
"init_special_inode: bogus i_mode (%o) for"
2127 " inode %s:%lu\n", mode
, inode
->i_sb
->s_id
,
2130 EXPORT_SYMBOL(init_special_inode
);
2133 * inode_init_owner - Init uid,gid,mode for new inode according to posix standards
2135 * @dir: Directory inode
2136 * @mode: mode of the new inode
2138 void inode_init_owner(struct inode
*inode
, const struct inode
*dir
,
2141 inode
->i_uid
= current_fsuid();
2142 if (dir
&& dir
->i_mode
& S_ISGID
) {
2143 inode
->i_gid
= dir
->i_gid
;
2145 /* Directories are special, and always inherit S_ISGID */
2148 else if ((mode
& (S_ISGID
| S_IXGRP
)) == (S_ISGID
| S_IXGRP
) &&
2149 !in_group_p(inode
->i_gid
) &&
2150 !capable_wrt_inode_uidgid(dir
, CAP_FSETID
))
2153 inode
->i_gid
= current_fsgid();
2154 inode
->i_mode
= mode
;
2156 EXPORT_SYMBOL(inode_init_owner
);
2159 * inode_owner_or_capable - check current task permissions to inode
2160 * @inode: inode being checked
2162 * Return true if current either has CAP_FOWNER in a namespace with the
2163 * inode owner uid mapped, or owns the file.
2165 bool inode_owner_or_capable(const struct inode
*inode
)
2167 struct user_namespace
*ns
;
2169 if (uid_eq(current_fsuid(), inode
->i_uid
))
2172 ns
= current_user_ns();
2173 if (kuid_has_mapping(ns
, inode
->i_uid
) && ns_capable(ns
, CAP_FOWNER
))
2177 EXPORT_SYMBOL(inode_owner_or_capable
);
2180 * Direct i/o helper functions
2182 static void __inode_dio_wait(struct inode
*inode
)
2184 wait_queue_head_t
*wq
= bit_waitqueue(&inode
->i_state
, __I_DIO_WAKEUP
);
2185 DEFINE_WAIT_BIT(q
, &inode
->i_state
, __I_DIO_WAKEUP
);
2188 prepare_to_wait(wq
, &q
.wq_entry
, TASK_UNINTERRUPTIBLE
);
2189 if (atomic_read(&inode
->i_dio_count
))
2191 } while (atomic_read(&inode
->i_dio_count
));
2192 finish_wait(wq
, &q
.wq_entry
);
2196 * inode_dio_wait - wait for outstanding DIO requests to finish
2197 * @inode: inode to wait for
2199 * Waits for all pending direct I/O requests to finish so that we can
2200 * proceed with a truncate or equivalent operation.
2202 * Must be called under a lock that serializes taking new references
2203 * to i_dio_count, usually by inode->i_mutex.
2205 void inode_dio_wait(struct inode
*inode
)
2207 if (atomic_read(&inode
->i_dio_count
))
2208 __inode_dio_wait(inode
);
2210 EXPORT_SYMBOL(inode_dio_wait
);
2213 * inode_set_flags - atomically set some inode flags
2215 * Note: the caller should be holding i_mutex, or else be sure that
2216 * they have exclusive access to the inode structure (i.e., while the
2217 * inode is being instantiated). The reason for the cmpxchg() loop
2218 * --- which wouldn't be necessary if all code paths which modify
2219 * i_flags actually followed this rule, is that there is at least one
2220 * code path which doesn't today so we use cmpxchg() out of an abundance
2223 * In the long run, i_mutex is overkill, and we should probably look
2224 * at using the i_lock spinlock to protect i_flags, and then make sure
2225 * it is so documented in include/linux/fs.h and that all code follows
2226 * the locking convention!!
2228 void inode_set_flags(struct inode
*inode
, unsigned int flags
,
2231 WARN_ON_ONCE(flags
& ~mask
);
2232 set_mask_bits(&inode
->i_flags
, mask
, flags
);
2234 EXPORT_SYMBOL(inode_set_flags
);
2236 void inode_nohighmem(struct inode
*inode
)
2238 mapping_set_gfp_mask(inode
->i_mapping
, GFP_USER
);
2240 EXPORT_SYMBOL(inode_nohighmem
);
2243 * timestamp_truncate - Truncate timespec to a granularity
2245 * @inode: inode being updated
2247 * Truncate a timespec to the granularity supported by the fs
2248 * containing the inode. Always rounds down. gran must
2249 * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns).
2251 struct timespec64
timestamp_truncate(struct timespec64 t
, struct inode
*inode
)
2253 struct super_block
*sb
= inode
->i_sb
;
2254 unsigned int gran
= sb
->s_time_gran
;
2256 t
.tv_sec
= clamp(t
.tv_sec
, sb
->s_time_min
, sb
->s_time_max
);
2257 if (unlikely(t
.tv_sec
== sb
->s_time_max
|| t
.tv_sec
== sb
->s_time_min
))
2260 /* Avoid division in the common cases 1 ns and 1 s. */
2263 else if (gran
== NSEC_PER_SEC
)
2265 else if (gran
> 1 && gran
< NSEC_PER_SEC
)
2266 t
.tv_nsec
-= t
.tv_nsec
% gran
;
2268 WARN(1, "invalid file time granularity: %u", gran
);
2271 EXPORT_SYMBOL(timestamp_truncate
);
2274 * current_time - Return FS time
2277 * Return the current time truncated to the time granularity supported by
2280 * Note that inode and inode->sb cannot be NULL.
2281 * Otherwise, the function warns and returns time without truncation.
2283 struct timespec64
current_time(struct inode
*inode
)
2285 struct timespec64 now
;
2287 ktime_get_coarse_real_ts64(&now
);
2289 if (unlikely(!inode
->i_sb
)) {
2290 WARN(1, "current_time() called with uninitialized super_block in the inode");
2294 return timestamp_truncate(now
, inode
);
2296 EXPORT_SYMBOL(current_time
);
2299 * Generic function to check FS_IOC_SETFLAGS values and reject any invalid
2302 * Note: the caller should be holding i_mutex, or else be sure that they have
2303 * exclusive access to the inode structure.
2305 int vfs_ioc_setflags_prepare(struct inode
*inode
, unsigned int oldflags
,
2309 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
2310 * the relevant capability.
2312 * This test looks nicer. Thanks to Pauline Middelink
2314 if ((flags
^ oldflags
) & (FS_APPEND_FL
| FS_IMMUTABLE_FL
) &&
2315 !capable(CAP_LINUX_IMMUTABLE
))
2318 return fscrypt_prepare_setflags(inode
, oldflags
, flags
);
2320 EXPORT_SYMBOL(vfs_ioc_setflags_prepare
);
2323 * Generic function to check FS_IOC_FSSETXATTR values and reject any invalid
2326 * Note: the caller should be holding i_mutex, or else be sure that they have
2327 * exclusive access to the inode structure.
2329 int vfs_ioc_fssetxattr_check(struct inode
*inode
, const struct fsxattr
*old_fa
,
2333 * Can't modify an immutable/append-only file unless we have
2334 * appropriate permission.
2336 if ((old_fa
->fsx_xflags
^ fa
->fsx_xflags
) &
2337 (FS_XFLAG_IMMUTABLE
| FS_XFLAG_APPEND
) &&
2338 !capable(CAP_LINUX_IMMUTABLE
))
2342 * Project Quota ID state is only allowed to change from within the init
2343 * namespace. Enforce that restriction only if we are trying to change
2344 * the quota ID state. Everything else is allowed in user namespaces.
2346 if (current_user_ns() != &init_user_ns
) {
2347 if (old_fa
->fsx_projid
!= fa
->fsx_projid
)
2349 if ((old_fa
->fsx_xflags
^ fa
->fsx_xflags
) &
2350 FS_XFLAG_PROJINHERIT
)
2354 /* Check extent size hints. */
2355 if ((fa
->fsx_xflags
& FS_XFLAG_EXTSIZE
) && !S_ISREG(inode
->i_mode
))
2358 if ((fa
->fsx_xflags
& FS_XFLAG_EXTSZINHERIT
) &&
2359 !S_ISDIR(inode
->i_mode
))
2362 if ((fa
->fsx_xflags
& FS_XFLAG_COWEXTSIZE
) &&
2363 !S_ISREG(inode
->i_mode
) && !S_ISDIR(inode
->i_mode
))
2367 * It is only valid to set the DAX flag on regular files and
2368 * directories on filesystems.
2370 if ((fa
->fsx_xflags
& FS_XFLAG_DAX
) &&
2371 !(S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
)))
2374 /* Extent size hints of zero turn off the flags. */
2375 if (fa
->fsx_extsize
== 0)
2376 fa
->fsx_xflags
&= ~(FS_XFLAG_EXTSIZE
| FS_XFLAG_EXTSZINHERIT
);
2377 if (fa
->fsx_cowextsize
== 0)
2378 fa
->fsx_xflags
&= ~FS_XFLAG_COWEXTSIZE
;
2382 EXPORT_SYMBOL(vfs_ioc_fssetxattr_check
);