2 * (C) 1997 Linus Torvalds
3 * (C) 1999 Andrea Arcangeli <andrea@suse.de> (dynamic inode allocation)
5 #include <linux/export.h>
8 #include <linux/backing-dev.h>
9 #include <linux/hash.h>
10 #include <linux/swap.h>
11 #include <linux/security.h>
12 #include <linux/cdev.h>
13 #include <linux/bootmem.h>
14 #include <linux/fsnotify.h>
15 #include <linux/mount.h>
16 #include <linux/posix_acl.h>
17 #include <linux/prefetch.h>
18 #include <linux/buffer_head.h> /* for inode_has_buffers */
19 #include <linux/ratelimit.h>
20 #include <linux/list_lru.h>
24 * Inode locking rules:
26 * inode->i_lock protects:
27 * inode->i_state, inode->i_hash, __iget()
28 * Inode LRU list locks protect:
29 * inode->i_sb->s_inode_lru, inode->i_lru
30 * inode_sb_list_lock protects:
31 * sb->s_inodes, inode->i_sb_list
32 * bdi->wb.list_lock protects:
33 * bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list
34 * inode_hash_lock protects:
35 * inode_hashtable, inode->i_hash
41 * Inode LRU list locks
54 static unsigned int i_hash_mask __read_mostly
;
55 static unsigned int i_hash_shift __read_mostly
;
56 static struct hlist_head
*inode_hashtable __read_mostly
;
57 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(inode_hash_lock
);
59 __cacheline_aligned_in_smp
DEFINE_SPINLOCK(inode_sb_list_lock
);
62 * Empty aops. Can be used for the cases where the user does not
63 * define any of the address_space operations.
65 const struct address_space_operations empty_aops
= {
67 EXPORT_SYMBOL(empty_aops
);
70 * Statistics gathering..
72 struct inodes_stat_t inodes_stat
;
74 static DEFINE_PER_CPU(unsigned long, nr_inodes
);
75 static DEFINE_PER_CPU(unsigned long, nr_unused
);
77 static struct kmem_cache
*inode_cachep __read_mostly
;
79 static long get_nr_inodes(void)
83 for_each_possible_cpu(i
)
84 sum
+= per_cpu(nr_inodes
, i
);
85 return sum
< 0 ? 0 : sum
;
88 static inline long get_nr_inodes_unused(void)
92 for_each_possible_cpu(i
)
93 sum
+= per_cpu(nr_unused
, i
);
94 return sum
< 0 ? 0 : sum
;
97 long get_nr_dirty_inodes(void)
99 /* not actually dirty inodes, but a wild approximation */
100 long nr_dirty
= get_nr_inodes() - get_nr_inodes_unused();
101 return nr_dirty
> 0 ? nr_dirty
: 0;
105 * Handle nr_inode sysctl
108 int proc_nr_inodes(struct ctl_table
*table
, int write
,
109 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
111 inodes_stat
.nr_inodes
= get_nr_inodes();
112 inodes_stat
.nr_unused
= get_nr_inodes_unused();
113 return proc_doulongvec_minmax(table
, write
, buffer
, lenp
, ppos
);
117 static int no_open(struct inode
*inode
, struct file
*file
)
123 * inode_init_always - perform inode structure intialisation
124 * @sb: superblock inode belongs to
125 * @inode: inode to initialise
127 * These are initializations that need to be done on every inode
128 * allocation as the fields are not initialised by slab allocation.
130 int inode_init_always(struct super_block
*sb
, struct inode
*inode
)
132 static const struct inode_operations empty_iops
;
133 static const struct file_operations no_open_fops
= {.open
= no_open
};
134 struct address_space
*const mapping
= &inode
->i_data
;
137 inode
->i_blkbits
= sb
->s_blocksize_bits
;
139 atomic_set(&inode
->i_count
, 1);
140 inode
->i_op
= &empty_iops
;
141 inode
->i_fop
= &no_open_fops
;
142 inode
->__i_nlink
= 1;
143 inode
->i_opflags
= 0;
144 i_uid_write(inode
, 0);
145 i_gid_write(inode
, 0);
146 atomic_set(&inode
->i_writecount
, 0);
150 inode
->i_generation
= 0;
151 inode
->i_pipe
= NULL
;
152 inode
->i_bdev
= NULL
;
153 inode
->i_cdev
= NULL
;
155 inode
->dirtied_when
= 0;
157 if (security_inode_alloc(inode
))
159 spin_lock_init(&inode
->i_lock
);
160 lockdep_set_class(&inode
->i_lock
, &sb
->s_type
->i_lock_key
);
162 mutex_init(&inode
->i_mutex
);
163 lockdep_set_class(&inode
->i_mutex
, &sb
->s_type
->i_mutex_key
);
165 atomic_set(&inode
->i_dio_count
, 0);
167 mapping
->a_ops
= &empty_aops
;
168 mapping
->host
= inode
;
170 atomic_set(&mapping
->i_mmap_writable
, 0);
171 mapping_set_gfp_mask(mapping
, GFP_HIGHUSER_MOVABLE
);
172 mapping
->private_data
= NULL
;
173 mapping
->writeback_index
= 0;
174 inode
->i_private
= NULL
;
175 inode
->i_mapping
= mapping
;
176 INIT_HLIST_HEAD(&inode
->i_dentry
); /* buggered by rcu freeing */
177 #ifdef CONFIG_FS_POSIX_ACL
178 inode
->i_acl
= inode
->i_default_acl
= ACL_NOT_CACHED
;
181 #ifdef CONFIG_FSNOTIFY
182 inode
->i_fsnotify_mask
= 0;
184 inode
->i_flctx
= NULL
;
185 this_cpu_inc(nr_inodes
);
191 EXPORT_SYMBOL(inode_init_always
);
193 static struct inode
*alloc_inode(struct super_block
*sb
)
197 if (sb
->s_op
->alloc_inode
)
198 inode
= sb
->s_op
->alloc_inode(sb
);
200 inode
= kmem_cache_alloc(inode_cachep
, GFP_KERNEL
);
205 if (unlikely(inode_init_always(sb
, inode
))) {
206 if (inode
->i_sb
->s_op
->destroy_inode
)
207 inode
->i_sb
->s_op
->destroy_inode(inode
);
209 kmem_cache_free(inode_cachep
, inode
);
216 void free_inode_nonrcu(struct inode
*inode
)
218 kmem_cache_free(inode_cachep
, inode
);
220 EXPORT_SYMBOL(free_inode_nonrcu
);
222 void __destroy_inode(struct inode
*inode
)
224 BUG_ON(inode_has_buffers(inode
));
225 security_inode_free(inode
);
226 fsnotify_inode_delete(inode
);
227 locks_free_lock_context(inode
->i_flctx
);
228 if (!inode
->i_nlink
) {
229 WARN_ON(atomic_long_read(&inode
->i_sb
->s_remove_count
) == 0);
230 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
233 #ifdef CONFIG_FS_POSIX_ACL
234 if (inode
->i_acl
&& inode
->i_acl
!= ACL_NOT_CACHED
)
235 posix_acl_release(inode
->i_acl
);
236 if (inode
->i_default_acl
&& inode
->i_default_acl
!= ACL_NOT_CACHED
)
237 posix_acl_release(inode
->i_default_acl
);
239 this_cpu_dec(nr_inodes
);
241 EXPORT_SYMBOL(__destroy_inode
);
243 static void i_callback(struct rcu_head
*head
)
245 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
246 kmem_cache_free(inode_cachep
, inode
);
249 static void destroy_inode(struct inode
*inode
)
251 BUG_ON(!list_empty(&inode
->i_lru
));
252 __destroy_inode(inode
);
253 if (inode
->i_sb
->s_op
->destroy_inode
)
254 inode
->i_sb
->s_op
->destroy_inode(inode
);
256 call_rcu(&inode
->i_rcu
, i_callback
);
260 * drop_nlink - directly drop an inode's link count
263 * This is a low-level filesystem helper to replace any
264 * direct filesystem manipulation of i_nlink. In cases
265 * where we are attempting to track writes to the
266 * filesystem, a decrement to zero means an imminent
267 * write when the file is truncated and actually unlinked
270 void drop_nlink(struct inode
*inode
)
272 WARN_ON(inode
->i_nlink
== 0);
275 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
277 EXPORT_SYMBOL(drop_nlink
);
280 * clear_nlink - directly zero an inode's link count
283 * This is a low-level filesystem helper to replace any
284 * direct filesystem manipulation of i_nlink. See
285 * drop_nlink() for why we care about i_nlink hitting zero.
287 void clear_nlink(struct inode
*inode
)
289 if (inode
->i_nlink
) {
290 inode
->__i_nlink
= 0;
291 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
294 EXPORT_SYMBOL(clear_nlink
);
297 * set_nlink - directly set an inode's link count
299 * @nlink: new nlink (should be non-zero)
301 * This is a low-level filesystem helper to replace any
302 * direct filesystem manipulation of i_nlink.
304 void set_nlink(struct inode
*inode
, unsigned int nlink
)
309 /* Yes, some filesystems do change nlink from zero to one */
310 if (inode
->i_nlink
== 0)
311 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
313 inode
->__i_nlink
= nlink
;
316 EXPORT_SYMBOL(set_nlink
);
319 * inc_nlink - directly increment an inode's link count
322 * This is a low-level filesystem helper to replace any
323 * direct filesystem manipulation of i_nlink. Currently,
324 * it is only here for parity with dec_nlink().
326 void inc_nlink(struct inode
*inode
)
328 if (unlikely(inode
->i_nlink
== 0)) {
329 WARN_ON(!(inode
->i_state
& I_LINKABLE
));
330 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
335 EXPORT_SYMBOL(inc_nlink
);
337 void address_space_init_once(struct address_space
*mapping
)
339 memset(mapping
, 0, sizeof(*mapping
));
340 INIT_RADIX_TREE(&mapping
->page_tree
, GFP_ATOMIC
);
341 spin_lock_init(&mapping
->tree_lock
);
342 init_rwsem(&mapping
->i_mmap_rwsem
);
343 INIT_LIST_HEAD(&mapping
->private_list
);
344 spin_lock_init(&mapping
->private_lock
);
345 mapping
->i_mmap
= RB_ROOT
;
347 EXPORT_SYMBOL(address_space_init_once
);
350 * These are initializations that only need to be done
351 * once, because the fields are idempotent across use
352 * of the inode, so let the slab aware of that.
354 void inode_init_once(struct inode
*inode
)
356 memset(inode
, 0, sizeof(*inode
));
357 INIT_HLIST_NODE(&inode
->i_hash
);
358 INIT_LIST_HEAD(&inode
->i_devices
);
359 INIT_LIST_HEAD(&inode
->i_wb_list
);
360 INIT_LIST_HEAD(&inode
->i_lru
);
361 address_space_init_once(&inode
->i_data
);
362 i_size_ordered_init(inode
);
363 #ifdef CONFIG_FSNOTIFY
364 INIT_HLIST_HEAD(&inode
->i_fsnotify_marks
);
367 EXPORT_SYMBOL(inode_init_once
);
369 static void init_once(void *foo
)
371 struct inode
*inode
= (struct inode
*) foo
;
373 inode_init_once(inode
);
377 * inode->i_lock must be held
379 void __iget(struct inode
*inode
)
381 atomic_inc(&inode
->i_count
);
385 * get additional reference to inode; caller must already hold one.
387 void ihold(struct inode
*inode
)
389 WARN_ON(atomic_inc_return(&inode
->i_count
) < 2);
391 EXPORT_SYMBOL(ihold
);
393 static void inode_lru_list_add(struct inode
*inode
)
395 if (list_lru_add(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
396 this_cpu_inc(nr_unused
);
400 * Add inode to LRU if needed (inode is unused and clean).
402 * Needs inode->i_lock held.
404 void inode_add_lru(struct inode
*inode
)
406 if (!(inode
->i_state
& (I_DIRTY
| I_SYNC
| I_FREEING
| I_WILL_FREE
)) &&
407 !atomic_read(&inode
->i_count
) && inode
->i_sb
->s_flags
& MS_ACTIVE
)
408 inode_lru_list_add(inode
);
412 static void inode_lru_list_del(struct inode
*inode
)
415 if (list_lru_del(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
416 this_cpu_dec(nr_unused
);
420 * inode_sb_list_add - add inode to the superblock list of inodes
421 * @inode: inode to add
423 void inode_sb_list_add(struct inode
*inode
)
425 spin_lock(&inode_sb_list_lock
);
426 list_add(&inode
->i_sb_list
, &inode
->i_sb
->s_inodes
);
427 spin_unlock(&inode_sb_list_lock
);
429 EXPORT_SYMBOL_GPL(inode_sb_list_add
);
431 static inline void inode_sb_list_del(struct inode
*inode
)
433 if (!list_empty(&inode
->i_sb_list
)) {
434 spin_lock(&inode_sb_list_lock
);
435 list_del_init(&inode
->i_sb_list
);
436 spin_unlock(&inode_sb_list_lock
);
440 static unsigned long hash(struct super_block
*sb
, unsigned long hashval
)
444 tmp
= (hashval
* (unsigned long)sb
) ^ (GOLDEN_RATIO_PRIME
+ hashval
) /
446 tmp
= tmp
^ ((tmp
^ GOLDEN_RATIO_PRIME
) >> i_hash_shift
);
447 return tmp
& i_hash_mask
;
451 * __insert_inode_hash - hash an inode
452 * @inode: unhashed inode
453 * @hashval: unsigned long value used to locate this object in the
456 * Add an inode to the inode hash for this superblock.
458 void __insert_inode_hash(struct inode
*inode
, unsigned long hashval
)
460 struct hlist_head
*b
= inode_hashtable
+ hash(inode
->i_sb
, hashval
);
462 spin_lock(&inode_hash_lock
);
463 spin_lock(&inode
->i_lock
);
464 hlist_add_head(&inode
->i_hash
, b
);
465 spin_unlock(&inode
->i_lock
);
466 spin_unlock(&inode_hash_lock
);
468 EXPORT_SYMBOL(__insert_inode_hash
);
471 * __remove_inode_hash - remove an inode from the hash
472 * @inode: inode to unhash
474 * Remove an inode from the superblock.
476 void __remove_inode_hash(struct inode
*inode
)
478 spin_lock(&inode_hash_lock
);
479 spin_lock(&inode
->i_lock
);
480 hlist_del_init(&inode
->i_hash
);
481 spin_unlock(&inode
->i_lock
);
482 spin_unlock(&inode_hash_lock
);
484 EXPORT_SYMBOL(__remove_inode_hash
);
486 void clear_inode(struct inode
*inode
)
490 * We have to cycle tree_lock here because reclaim can be still in the
491 * process of removing the last page (in __delete_from_page_cache())
492 * and we must not free mapping under it.
494 spin_lock_irq(&inode
->i_data
.tree_lock
);
495 BUG_ON(inode
->i_data
.nrpages
);
496 BUG_ON(inode
->i_data
.nrshadows
);
497 spin_unlock_irq(&inode
->i_data
.tree_lock
);
498 BUG_ON(!list_empty(&inode
->i_data
.private_list
));
499 BUG_ON(!(inode
->i_state
& I_FREEING
));
500 BUG_ON(inode
->i_state
& I_CLEAR
);
501 /* don't need i_lock here, no concurrent mods to i_state */
502 inode
->i_state
= I_FREEING
| I_CLEAR
;
504 EXPORT_SYMBOL(clear_inode
);
507 * Free the inode passed in, removing it from the lists it is still connected
508 * to. We remove any pages still attached to the inode and wait for any IO that
509 * is still in progress before finally destroying the inode.
511 * An inode must already be marked I_FREEING so that we avoid the inode being
512 * moved back onto lists if we race with other code that manipulates the lists
513 * (e.g. writeback_single_inode). The caller is responsible for setting this.
515 * An inode must already be removed from the LRU list before being evicted from
516 * the cache. This should occur atomically with setting the I_FREEING state
517 * flag, so no inodes here should ever be on the LRU when being evicted.
519 static void evict(struct inode
*inode
)
521 const struct super_operations
*op
= inode
->i_sb
->s_op
;
523 BUG_ON(!(inode
->i_state
& I_FREEING
));
524 BUG_ON(!list_empty(&inode
->i_lru
));
526 if (!list_empty(&inode
->i_wb_list
))
527 inode_wb_list_del(inode
);
529 inode_sb_list_del(inode
);
532 * Wait for flusher thread to be done with the inode so that filesystem
533 * does not start destroying it while writeback is still running. Since
534 * the inode has I_FREEING set, flusher thread won't start new work on
535 * the inode. We just have to wait for running writeback to finish.
537 inode_wait_for_writeback(inode
);
539 if (op
->evict_inode
) {
540 op
->evict_inode(inode
);
542 truncate_inode_pages_final(&inode
->i_data
);
545 if (S_ISBLK(inode
->i_mode
) && inode
->i_bdev
)
547 if (S_ISCHR(inode
->i_mode
) && inode
->i_cdev
)
550 remove_inode_hash(inode
);
552 spin_lock(&inode
->i_lock
);
553 wake_up_bit(&inode
->i_state
, __I_NEW
);
554 BUG_ON(inode
->i_state
!= (I_FREEING
| I_CLEAR
));
555 spin_unlock(&inode
->i_lock
);
557 destroy_inode(inode
);
561 * dispose_list - dispose of the contents of a local list
562 * @head: the head of the list to free
564 * Dispose-list gets a local list with local inodes in it, so it doesn't
565 * need to worry about list corruption and SMP locks.
567 static void dispose_list(struct list_head
*head
)
569 while (!list_empty(head
)) {
572 inode
= list_first_entry(head
, struct inode
, i_lru
);
573 list_del_init(&inode
->i_lru
);
580 * evict_inodes - evict all evictable inodes for a superblock
581 * @sb: superblock to operate on
583 * Make sure that no inodes with zero refcount are retained. This is
584 * called by superblock shutdown after having MS_ACTIVE flag removed,
585 * so any inode reaching zero refcount during or after that call will
586 * be immediately evicted.
588 void evict_inodes(struct super_block
*sb
)
590 struct inode
*inode
, *next
;
593 spin_lock(&inode_sb_list_lock
);
594 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
595 if (atomic_read(&inode
->i_count
))
598 spin_lock(&inode
->i_lock
);
599 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
600 spin_unlock(&inode
->i_lock
);
604 inode
->i_state
|= I_FREEING
;
605 inode_lru_list_del(inode
);
606 spin_unlock(&inode
->i_lock
);
607 list_add(&inode
->i_lru
, &dispose
);
609 spin_unlock(&inode_sb_list_lock
);
611 dispose_list(&dispose
);
615 * invalidate_inodes - attempt to free all inodes on a superblock
616 * @sb: superblock to operate on
617 * @kill_dirty: flag to guide handling of dirty inodes
619 * Attempts to free all inodes for a given superblock. If there were any
620 * busy inodes return a non-zero value, else zero.
621 * If @kill_dirty is set, discard dirty inodes too, otherwise treat
624 int invalidate_inodes(struct super_block
*sb
, bool kill_dirty
)
627 struct inode
*inode
, *next
;
630 spin_lock(&inode_sb_list_lock
);
631 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
632 spin_lock(&inode
->i_lock
);
633 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
634 spin_unlock(&inode
->i_lock
);
637 if (inode
->i_state
& I_DIRTY
&& !kill_dirty
) {
638 spin_unlock(&inode
->i_lock
);
642 if (atomic_read(&inode
->i_count
)) {
643 spin_unlock(&inode
->i_lock
);
648 inode
->i_state
|= I_FREEING
;
649 inode_lru_list_del(inode
);
650 spin_unlock(&inode
->i_lock
);
651 list_add(&inode
->i_lru
, &dispose
);
653 spin_unlock(&inode_sb_list_lock
);
655 dispose_list(&dispose
);
661 * Isolate the inode from the LRU in preparation for freeing it.
663 * Any inodes which are pinned purely because of attached pagecache have their
664 * pagecache removed. If the inode has metadata buffers attached to
665 * mapping->private_list then try to remove them.
667 * If the inode has the I_REFERENCED flag set, then it means that it has been
668 * used recently - the flag is set in iput_final(). When we encounter such an
669 * inode, clear the flag and move it to the back of the LRU so it gets another
670 * pass through the LRU before it gets reclaimed. This is necessary because of
671 * the fact we are doing lazy LRU updates to minimise lock contention so the
672 * LRU does not have strict ordering. Hence we don't want to reclaim inodes
673 * with this flag set because they are the inodes that are out of order.
675 static enum lru_status
inode_lru_isolate(struct list_head
*item
,
676 struct list_lru_one
*lru
, spinlock_t
*lru_lock
, void *arg
)
678 struct list_head
*freeable
= arg
;
679 struct inode
*inode
= container_of(item
, struct inode
, i_lru
);
682 * we are inverting the lru lock/inode->i_lock here, so use a trylock.
683 * If we fail to get the lock, just skip it.
685 if (!spin_trylock(&inode
->i_lock
))
689 * Referenced or dirty inodes are still in use. Give them another pass
690 * through the LRU as we canot reclaim them now.
692 if (atomic_read(&inode
->i_count
) ||
693 (inode
->i_state
& ~I_REFERENCED
)) {
694 list_lru_isolate(lru
, &inode
->i_lru
);
695 spin_unlock(&inode
->i_lock
);
696 this_cpu_dec(nr_unused
);
700 /* recently referenced inodes get one more pass */
701 if (inode
->i_state
& I_REFERENCED
) {
702 inode
->i_state
&= ~I_REFERENCED
;
703 spin_unlock(&inode
->i_lock
);
707 if (inode_has_buffers(inode
) || inode
->i_data
.nrpages
) {
709 spin_unlock(&inode
->i_lock
);
710 spin_unlock(lru_lock
);
711 if (remove_inode_buffers(inode
)) {
713 reap
= invalidate_mapping_pages(&inode
->i_data
, 0, -1);
714 if (current_is_kswapd())
715 __count_vm_events(KSWAPD_INODESTEAL
, reap
);
717 __count_vm_events(PGINODESTEAL
, reap
);
718 if (current
->reclaim_state
)
719 current
->reclaim_state
->reclaimed_slab
+= reap
;
726 WARN_ON(inode
->i_state
& I_NEW
);
727 inode
->i_state
|= I_FREEING
;
728 list_lru_isolate_move(lru
, &inode
->i_lru
, freeable
);
729 spin_unlock(&inode
->i_lock
);
731 this_cpu_dec(nr_unused
);
736 * Walk the superblock inode LRU for freeable inodes and attempt to free them.
737 * This is called from the superblock shrinker function with a number of inodes
738 * to trim from the LRU. Inodes to be freed are moved to a temporary list and
739 * then are freed outside inode_lock by dispose_list().
741 long prune_icache_sb(struct super_block
*sb
, struct shrink_control
*sc
)
746 freed
= list_lru_shrink_walk(&sb
->s_inode_lru
, sc
,
747 inode_lru_isolate
, &freeable
);
748 dispose_list(&freeable
);
752 static void __wait_on_freeing_inode(struct inode
*inode
);
754 * Called with the inode lock held.
756 static struct inode
*find_inode(struct super_block
*sb
,
757 struct hlist_head
*head
,
758 int (*test
)(struct inode
*, void *),
761 struct inode
*inode
= NULL
;
764 hlist_for_each_entry(inode
, head
, i_hash
) {
765 if (inode
->i_sb
!= sb
)
767 if (!test(inode
, data
))
769 spin_lock(&inode
->i_lock
);
770 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
771 __wait_on_freeing_inode(inode
);
775 spin_unlock(&inode
->i_lock
);
782 * find_inode_fast is the fast path version of find_inode, see the comment at
783 * iget_locked for details.
785 static struct inode
*find_inode_fast(struct super_block
*sb
,
786 struct hlist_head
*head
, unsigned long ino
)
788 struct inode
*inode
= NULL
;
791 hlist_for_each_entry(inode
, head
, i_hash
) {
792 if (inode
->i_ino
!= ino
)
794 if (inode
->i_sb
!= sb
)
796 spin_lock(&inode
->i_lock
);
797 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
798 __wait_on_freeing_inode(inode
);
802 spin_unlock(&inode
->i_lock
);
809 * Each cpu owns a range of LAST_INO_BATCH numbers.
810 * 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations,
811 * to renew the exhausted range.
813 * This does not significantly increase overflow rate because every CPU can
814 * consume at most LAST_INO_BATCH-1 unused inode numbers. So there is
815 * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the
816 * 2^32 range, and is a worst-case. Even a 50% wastage would only increase
817 * overflow rate by 2x, which does not seem too significant.
819 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
820 * error if st_ino won't fit in target struct field. Use 32bit counter
821 * here to attempt to avoid that.
823 #define LAST_INO_BATCH 1024
824 static DEFINE_PER_CPU(unsigned int, last_ino
);
826 unsigned int get_next_ino(void)
828 unsigned int *p
= &get_cpu_var(last_ino
);
829 unsigned int res
= *p
;
832 if (unlikely((res
& (LAST_INO_BATCH
-1)) == 0)) {
833 static atomic_t shared_last_ino
;
834 int next
= atomic_add_return(LAST_INO_BATCH
, &shared_last_ino
);
836 res
= next
- LAST_INO_BATCH
;
841 put_cpu_var(last_ino
);
844 EXPORT_SYMBOL(get_next_ino
);
847 * new_inode_pseudo - obtain an inode
850 * Allocates a new inode for given superblock.
851 * Inode wont be chained in superblock s_inodes list
853 * - fs can't be unmount
854 * - quotas, fsnotify, writeback can't work
856 struct inode
*new_inode_pseudo(struct super_block
*sb
)
858 struct inode
*inode
= alloc_inode(sb
);
861 spin_lock(&inode
->i_lock
);
863 spin_unlock(&inode
->i_lock
);
864 INIT_LIST_HEAD(&inode
->i_sb_list
);
870 * new_inode - obtain an inode
873 * Allocates a new inode for given superblock. The default gfp_mask
874 * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE.
875 * If HIGHMEM pages are unsuitable or it is known that pages allocated
876 * for the page cache are not reclaimable or migratable,
877 * mapping_set_gfp_mask() must be called with suitable flags on the
878 * newly created inode's mapping
881 struct inode
*new_inode(struct super_block
*sb
)
885 spin_lock_prefetch(&inode_sb_list_lock
);
887 inode
= new_inode_pseudo(sb
);
889 inode_sb_list_add(inode
);
892 EXPORT_SYMBOL(new_inode
);
894 #ifdef CONFIG_DEBUG_LOCK_ALLOC
895 void lockdep_annotate_inode_mutex_key(struct inode
*inode
)
897 if (S_ISDIR(inode
->i_mode
)) {
898 struct file_system_type
*type
= inode
->i_sb
->s_type
;
900 /* Set new key only if filesystem hasn't already changed it */
901 if (lockdep_match_class(&inode
->i_mutex
, &type
->i_mutex_key
)) {
903 * ensure nobody is actually holding i_mutex
905 mutex_destroy(&inode
->i_mutex
);
906 mutex_init(&inode
->i_mutex
);
907 lockdep_set_class(&inode
->i_mutex
,
908 &type
->i_mutex_dir_key
);
912 EXPORT_SYMBOL(lockdep_annotate_inode_mutex_key
);
916 * unlock_new_inode - clear the I_NEW state and wake up any waiters
917 * @inode: new inode to unlock
919 * Called when the inode is fully initialised to clear the new state of the
920 * inode and wake up anyone waiting for the inode to finish initialisation.
922 void unlock_new_inode(struct inode
*inode
)
924 lockdep_annotate_inode_mutex_key(inode
);
925 spin_lock(&inode
->i_lock
);
926 WARN_ON(!(inode
->i_state
& I_NEW
));
927 inode
->i_state
&= ~I_NEW
;
929 wake_up_bit(&inode
->i_state
, __I_NEW
);
930 spin_unlock(&inode
->i_lock
);
932 EXPORT_SYMBOL(unlock_new_inode
);
935 * lock_two_nondirectories - take two i_mutexes on non-directory objects
937 * Lock any non-NULL argument that is not a directory.
938 * Zero, one or two objects may be locked by this function.
940 * @inode1: first inode to lock
941 * @inode2: second inode to lock
943 void lock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
946 swap(inode1
, inode2
);
948 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
949 mutex_lock(&inode1
->i_mutex
);
950 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
951 mutex_lock_nested(&inode2
->i_mutex
, I_MUTEX_NONDIR2
);
953 EXPORT_SYMBOL(lock_two_nondirectories
);
956 * unlock_two_nondirectories - release locks from lock_two_nondirectories()
957 * @inode1: first inode to unlock
958 * @inode2: second inode to unlock
960 void unlock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
962 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
963 mutex_unlock(&inode1
->i_mutex
);
964 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
965 mutex_unlock(&inode2
->i_mutex
);
967 EXPORT_SYMBOL(unlock_two_nondirectories
);
970 * iget5_locked - obtain an inode from a mounted file system
971 * @sb: super block of file system
972 * @hashval: hash value (usually inode number) to get
973 * @test: callback used for comparisons between inodes
974 * @set: callback used to initialize a new struct inode
975 * @data: opaque data pointer to pass to @test and @set
977 * Search for the inode specified by @hashval and @data in the inode cache,
978 * and if present it is return it with an increased reference count. This is
979 * a generalized version of iget_locked() for file systems where the inode
980 * number is not sufficient for unique identification of an inode.
982 * If the inode is not in cache, allocate a new inode and return it locked,
983 * hashed, and with the I_NEW flag set. The file system gets to fill it in
984 * before unlocking it via unlock_new_inode().
986 * Note both @test and @set are called with the inode_hash_lock held, so can't
989 struct inode
*iget5_locked(struct super_block
*sb
, unsigned long hashval
,
990 int (*test
)(struct inode
*, void *),
991 int (*set
)(struct inode
*, void *), void *data
)
993 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
996 spin_lock(&inode_hash_lock
);
997 inode
= find_inode(sb
, head
, test
, data
);
998 spin_unlock(&inode_hash_lock
);
1001 wait_on_inode(inode
);
1005 inode
= alloc_inode(sb
);
1009 spin_lock(&inode_hash_lock
);
1010 /* We released the lock, so.. */
1011 old
= find_inode(sb
, head
, test
, data
);
1013 if (set(inode
, data
))
1016 spin_lock(&inode
->i_lock
);
1017 inode
->i_state
= I_NEW
;
1018 hlist_add_head(&inode
->i_hash
, head
);
1019 spin_unlock(&inode
->i_lock
);
1020 inode_sb_list_add(inode
);
1021 spin_unlock(&inode_hash_lock
);
1023 /* Return the locked inode with I_NEW set, the
1024 * caller is responsible for filling in the contents
1030 * Uhhuh, somebody else created the same inode under
1031 * us. Use the old inode instead of the one we just
1034 spin_unlock(&inode_hash_lock
);
1035 destroy_inode(inode
);
1037 wait_on_inode(inode
);
1042 spin_unlock(&inode_hash_lock
);
1043 destroy_inode(inode
);
1046 EXPORT_SYMBOL(iget5_locked
);
1049 * iget_locked - obtain an inode from a mounted file system
1050 * @sb: super block of file system
1051 * @ino: inode number to get
1053 * Search for the inode specified by @ino in the inode cache and if present
1054 * return it with an increased reference count. This is for file systems
1055 * where the inode number is sufficient for unique identification of an inode.
1057 * If the inode is not in cache, allocate a new inode and return it locked,
1058 * hashed, and with the I_NEW flag set. The file system gets to fill it in
1059 * before unlocking it via unlock_new_inode().
1061 struct inode
*iget_locked(struct super_block
*sb
, unsigned long ino
)
1063 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1064 struct inode
*inode
;
1066 spin_lock(&inode_hash_lock
);
1067 inode
= find_inode_fast(sb
, head
, ino
);
1068 spin_unlock(&inode_hash_lock
);
1070 wait_on_inode(inode
);
1074 inode
= alloc_inode(sb
);
1078 spin_lock(&inode_hash_lock
);
1079 /* We released the lock, so.. */
1080 old
= find_inode_fast(sb
, head
, ino
);
1083 spin_lock(&inode
->i_lock
);
1084 inode
->i_state
= I_NEW
;
1085 hlist_add_head(&inode
->i_hash
, head
);
1086 spin_unlock(&inode
->i_lock
);
1087 inode_sb_list_add(inode
);
1088 spin_unlock(&inode_hash_lock
);
1090 /* Return the locked inode with I_NEW set, the
1091 * caller is responsible for filling in the contents
1097 * Uhhuh, somebody else created the same inode under
1098 * us. Use the old inode instead of the one we just
1101 spin_unlock(&inode_hash_lock
);
1102 destroy_inode(inode
);
1104 wait_on_inode(inode
);
1108 EXPORT_SYMBOL(iget_locked
);
1111 * search the inode cache for a matching inode number.
1112 * If we find one, then the inode number we are trying to
1113 * allocate is not unique and so we should not use it.
1115 * Returns 1 if the inode number is unique, 0 if it is not.
1117 static int test_inode_iunique(struct super_block
*sb
, unsigned long ino
)
1119 struct hlist_head
*b
= inode_hashtable
+ hash(sb
, ino
);
1120 struct inode
*inode
;
1122 spin_lock(&inode_hash_lock
);
1123 hlist_for_each_entry(inode
, b
, i_hash
) {
1124 if (inode
->i_ino
== ino
&& inode
->i_sb
== sb
) {
1125 spin_unlock(&inode_hash_lock
);
1129 spin_unlock(&inode_hash_lock
);
1135 * iunique - get a unique inode number
1137 * @max_reserved: highest reserved inode number
1139 * Obtain an inode number that is unique on the system for a given
1140 * superblock. This is used by file systems that have no natural
1141 * permanent inode numbering system. An inode number is returned that
1142 * is higher than the reserved limit but unique.
1145 * With a large number of inodes live on the file system this function
1146 * currently becomes quite slow.
1148 ino_t
iunique(struct super_block
*sb
, ino_t max_reserved
)
1151 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
1152 * error if st_ino won't fit in target struct field. Use 32bit counter
1153 * here to attempt to avoid that.
1155 static DEFINE_SPINLOCK(iunique_lock
);
1156 static unsigned int counter
;
1159 spin_lock(&iunique_lock
);
1161 if (counter
<= max_reserved
)
1162 counter
= max_reserved
+ 1;
1164 } while (!test_inode_iunique(sb
, res
));
1165 spin_unlock(&iunique_lock
);
1169 EXPORT_SYMBOL(iunique
);
1171 struct inode
*igrab(struct inode
*inode
)
1173 spin_lock(&inode
->i_lock
);
1174 if (!(inode
->i_state
& (I_FREEING
|I_WILL_FREE
))) {
1176 spin_unlock(&inode
->i_lock
);
1178 spin_unlock(&inode
->i_lock
);
1180 * Handle the case where s_op->clear_inode is not been
1181 * called yet, and somebody is calling igrab
1182 * while the inode is getting freed.
1188 EXPORT_SYMBOL(igrab
);
1191 * ilookup5_nowait - search for an inode in the inode cache
1192 * @sb: super block of file system to search
1193 * @hashval: hash value (usually inode number) to search for
1194 * @test: callback used for comparisons between inodes
1195 * @data: opaque data pointer to pass to @test
1197 * Search for the inode specified by @hashval and @data in the inode cache.
1198 * If the inode is in the cache, the inode is returned with an incremented
1201 * Note: I_NEW is not waited upon so you have to be very careful what you do
1202 * with the returned inode. You probably should be using ilookup5() instead.
1204 * Note2: @test is called with the inode_hash_lock held, so can't sleep.
1206 struct inode
*ilookup5_nowait(struct super_block
*sb
, unsigned long hashval
,
1207 int (*test
)(struct inode
*, void *), void *data
)
1209 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1210 struct inode
*inode
;
1212 spin_lock(&inode_hash_lock
);
1213 inode
= find_inode(sb
, head
, test
, data
);
1214 spin_unlock(&inode_hash_lock
);
1218 EXPORT_SYMBOL(ilookup5_nowait
);
1221 * ilookup5 - search for an inode in the inode cache
1222 * @sb: super block of file system to search
1223 * @hashval: hash value (usually inode number) to search for
1224 * @test: callback used for comparisons between inodes
1225 * @data: opaque data pointer to pass to @test
1227 * Search for the inode specified by @hashval and @data in the inode cache,
1228 * and if the inode is in the cache, return the inode with an incremented
1229 * reference count. Waits on I_NEW before returning the inode.
1230 * returned with an incremented reference count.
1232 * This is a generalized version of ilookup() for file systems where the
1233 * inode number is not sufficient for unique identification of an inode.
1235 * Note: @test is called with the inode_hash_lock held, so can't sleep.
1237 struct inode
*ilookup5(struct super_block
*sb
, unsigned long hashval
,
1238 int (*test
)(struct inode
*, void *), void *data
)
1240 struct inode
*inode
= ilookup5_nowait(sb
, hashval
, test
, data
);
1243 wait_on_inode(inode
);
1246 EXPORT_SYMBOL(ilookup5
);
1249 * ilookup - search for an inode in the inode cache
1250 * @sb: super block of file system to search
1251 * @ino: inode number to search for
1253 * Search for the inode @ino in the inode cache, and if the inode is in the
1254 * cache, the inode is returned with an incremented reference count.
1256 struct inode
*ilookup(struct super_block
*sb
, unsigned long ino
)
1258 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1259 struct inode
*inode
;
1261 spin_lock(&inode_hash_lock
);
1262 inode
= find_inode_fast(sb
, head
, ino
);
1263 spin_unlock(&inode_hash_lock
);
1266 wait_on_inode(inode
);
1269 EXPORT_SYMBOL(ilookup
);
1271 int insert_inode_locked(struct inode
*inode
)
1273 struct super_block
*sb
= inode
->i_sb
;
1274 ino_t ino
= inode
->i_ino
;
1275 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1278 struct inode
*old
= NULL
;
1279 spin_lock(&inode_hash_lock
);
1280 hlist_for_each_entry(old
, head
, i_hash
) {
1281 if (old
->i_ino
!= ino
)
1283 if (old
->i_sb
!= sb
)
1285 spin_lock(&old
->i_lock
);
1286 if (old
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
1287 spin_unlock(&old
->i_lock
);
1293 spin_lock(&inode
->i_lock
);
1294 inode
->i_state
|= I_NEW
;
1295 hlist_add_head(&inode
->i_hash
, head
);
1296 spin_unlock(&inode
->i_lock
);
1297 spin_unlock(&inode_hash_lock
);
1301 spin_unlock(&old
->i_lock
);
1302 spin_unlock(&inode_hash_lock
);
1304 if (unlikely(!inode_unhashed(old
))) {
1311 EXPORT_SYMBOL(insert_inode_locked
);
1313 int insert_inode_locked4(struct inode
*inode
, unsigned long hashval
,
1314 int (*test
)(struct inode
*, void *), void *data
)
1316 struct super_block
*sb
= inode
->i_sb
;
1317 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1320 struct inode
*old
= NULL
;
1322 spin_lock(&inode_hash_lock
);
1323 hlist_for_each_entry(old
, head
, i_hash
) {
1324 if (old
->i_sb
!= sb
)
1326 if (!test(old
, data
))
1328 spin_lock(&old
->i_lock
);
1329 if (old
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
1330 spin_unlock(&old
->i_lock
);
1336 spin_lock(&inode
->i_lock
);
1337 inode
->i_state
|= I_NEW
;
1338 hlist_add_head(&inode
->i_hash
, head
);
1339 spin_unlock(&inode
->i_lock
);
1340 spin_unlock(&inode_hash_lock
);
1344 spin_unlock(&old
->i_lock
);
1345 spin_unlock(&inode_hash_lock
);
1347 if (unlikely(!inode_unhashed(old
))) {
1354 EXPORT_SYMBOL(insert_inode_locked4
);
1357 int generic_delete_inode(struct inode
*inode
)
1361 EXPORT_SYMBOL(generic_delete_inode
);
1364 * Called when we're dropping the last reference
1367 * Call the FS "drop_inode()" function, defaulting to
1368 * the legacy UNIX filesystem behaviour. If it tells
1369 * us to evict inode, do so. Otherwise, retain inode
1370 * in cache if fs is alive, sync and evict if fs is
1373 static void iput_final(struct inode
*inode
)
1375 struct super_block
*sb
= inode
->i_sb
;
1376 const struct super_operations
*op
= inode
->i_sb
->s_op
;
1379 WARN_ON(inode
->i_state
& I_NEW
);
1382 drop
= op
->drop_inode(inode
);
1384 drop
= generic_drop_inode(inode
);
1386 if (!drop
&& (sb
->s_flags
& MS_ACTIVE
)) {
1387 inode
->i_state
|= I_REFERENCED
;
1388 inode_add_lru(inode
);
1389 spin_unlock(&inode
->i_lock
);
1394 inode
->i_state
|= I_WILL_FREE
;
1395 spin_unlock(&inode
->i_lock
);
1396 write_inode_now(inode
, 1);
1397 spin_lock(&inode
->i_lock
);
1398 WARN_ON(inode
->i_state
& I_NEW
);
1399 inode
->i_state
&= ~I_WILL_FREE
;
1402 inode
->i_state
|= I_FREEING
;
1403 if (!list_empty(&inode
->i_lru
))
1404 inode_lru_list_del(inode
);
1405 spin_unlock(&inode
->i_lock
);
1411 * iput - put an inode
1412 * @inode: inode to put
1414 * Puts an inode, dropping its usage count. If the inode use count hits
1415 * zero, the inode is then freed and may also be destroyed.
1417 * Consequently, iput() can sleep.
1419 void iput(struct inode
*inode
)
1422 BUG_ON(inode
->i_state
& I_CLEAR
);
1424 if (atomic_dec_and_lock(&inode
->i_count
, &inode
->i_lock
))
1428 EXPORT_SYMBOL(iput
);
1431 * bmap - find a block number in a file
1432 * @inode: inode of file
1433 * @block: block to find
1435 * Returns the block number on the device holding the inode that
1436 * is the disk block number for the block of the file requested.
1437 * That is, asked for block 4 of inode 1 the function will return the
1438 * disk block relative to the disk start that holds that block of the
1441 sector_t
bmap(struct inode
*inode
, sector_t block
)
1444 if (inode
->i_mapping
->a_ops
->bmap
)
1445 res
= inode
->i_mapping
->a_ops
->bmap(inode
->i_mapping
, block
);
1448 EXPORT_SYMBOL(bmap
);
1451 * With relative atime, only update atime if the previous atime is
1452 * earlier than either the ctime or mtime or if at least a day has
1453 * passed since the last atime update.
1455 static int relatime_need_update(struct vfsmount
*mnt
, struct inode
*inode
,
1456 struct timespec now
)
1459 if (!(mnt
->mnt_flags
& MNT_RELATIME
))
1462 * Is mtime younger than atime? If yes, update atime:
1464 if (timespec_compare(&inode
->i_mtime
, &inode
->i_atime
) >= 0)
1467 * Is ctime younger than atime? If yes, update atime:
1469 if (timespec_compare(&inode
->i_ctime
, &inode
->i_atime
) >= 0)
1473 * Is the previous atime value older than a day? If yes,
1476 if ((long)(now
.tv_sec
- inode
->i_atime
.tv_sec
) >= 24*60*60)
1479 * Good, we can skip the atime update:
1485 * This does the actual work of updating an inodes time or version. Must have
1486 * had called mnt_want_write() before calling this.
1488 static int update_time(struct inode
*inode
, struct timespec
*time
, int flags
)
1490 if (inode
->i_op
->update_time
)
1491 return inode
->i_op
->update_time(inode
, time
, flags
);
1493 if (flags
& S_ATIME
)
1494 inode
->i_atime
= *time
;
1495 if (flags
& S_VERSION
)
1496 inode_inc_iversion(inode
);
1497 if (flags
& S_CTIME
)
1498 inode
->i_ctime
= *time
;
1499 if (flags
& S_MTIME
)
1500 inode
->i_mtime
= *time
;
1501 mark_inode_dirty_sync(inode
);
1506 * touch_atime - update the access time
1507 * @path: the &struct path to update
1509 * Update the accessed time on an inode and mark it for writeback.
1510 * This function automatically handles read only file systems and media,
1511 * as well as the "noatime" flag and inode specific "noatime" markers.
1513 void touch_atime(const struct path
*path
)
1515 struct vfsmount
*mnt
= path
->mnt
;
1516 struct inode
*inode
= path
->dentry
->d_inode
;
1517 struct timespec now
;
1519 if (inode
->i_flags
& S_NOATIME
)
1521 if (IS_NOATIME(inode
))
1523 if ((inode
->i_sb
->s_flags
& MS_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1526 if (mnt
->mnt_flags
& MNT_NOATIME
)
1528 if ((mnt
->mnt_flags
& MNT_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1531 now
= current_fs_time(inode
->i_sb
);
1533 if (!relatime_need_update(mnt
, inode
, now
))
1536 if (timespec_equal(&inode
->i_atime
, &now
))
1539 if (!sb_start_write_trylock(inode
->i_sb
))
1542 if (__mnt_want_write(mnt
))
1545 * File systems can error out when updating inodes if they need to
1546 * allocate new space to modify an inode (such is the case for
1547 * Btrfs), but since we touch atime while walking down the path we
1548 * really don't care if we failed to update the atime of the file,
1549 * so just ignore the return value.
1550 * We may also fail on filesystems that have the ability to make parts
1551 * of the fs read only, e.g. subvolumes in Btrfs.
1553 update_time(inode
, &now
, S_ATIME
);
1554 __mnt_drop_write(mnt
);
1556 sb_end_write(inode
->i_sb
);
1558 EXPORT_SYMBOL(touch_atime
);
1561 * The logic we want is
1563 * if suid or (sgid and xgrp)
1566 int should_remove_suid(struct dentry
*dentry
)
1568 umode_t mode
= dentry
->d_inode
->i_mode
;
1571 /* suid always must be killed */
1572 if (unlikely(mode
& S_ISUID
))
1573 kill
= ATTR_KILL_SUID
;
1576 * sgid without any exec bits is just a mandatory locking mark; leave
1577 * it alone. If some exec bits are set, it's a real sgid; kill it.
1579 if (unlikely((mode
& S_ISGID
) && (mode
& S_IXGRP
)))
1580 kill
|= ATTR_KILL_SGID
;
1582 if (unlikely(kill
&& !capable(CAP_FSETID
) && S_ISREG(mode
)))
1587 EXPORT_SYMBOL(should_remove_suid
);
1589 static int __remove_suid(struct dentry
*dentry
, int kill
)
1591 struct iattr newattrs
;
1593 newattrs
.ia_valid
= ATTR_FORCE
| kill
;
1595 * Note we call this on write, so notify_change will not
1596 * encounter any conflicting delegations:
1598 return notify_change(dentry
, &newattrs
, NULL
);
1601 int file_remove_suid(struct file
*file
)
1603 struct dentry
*dentry
= file
->f_path
.dentry
;
1604 struct inode
*inode
= dentry
->d_inode
;
1609 /* Fast path for nothing security related */
1610 if (IS_NOSEC(inode
))
1613 killsuid
= should_remove_suid(dentry
);
1614 killpriv
= security_inode_need_killpriv(dentry
);
1619 error
= security_inode_killpriv(dentry
);
1620 if (!error
&& killsuid
)
1621 error
= __remove_suid(dentry
, killsuid
);
1622 if (!error
&& (inode
->i_sb
->s_flags
& MS_NOSEC
))
1623 inode
->i_flags
|= S_NOSEC
;
1627 EXPORT_SYMBOL(file_remove_suid
);
1630 * file_update_time - update mtime and ctime time
1631 * @file: file accessed
1633 * Update the mtime and ctime members of an inode and mark the inode
1634 * for writeback. Note that this function is meant exclusively for
1635 * usage in the file write path of filesystems, and filesystems may
1636 * choose to explicitly ignore update via this function with the
1637 * S_NOCMTIME inode flag, e.g. for network filesystem where these
1638 * timestamps are handled by the server. This can return an error for
1639 * file systems who need to allocate space in order to update an inode.
1642 int file_update_time(struct file
*file
)
1644 struct inode
*inode
= file_inode(file
);
1645 struct timespec now
;
1649 /* First try to exhaust all avenues to not sync */
1650 if (IS_NOCMTIME(inode
))
1653 now
= current_fs_time(inode
->i_sb
);
1654 if (!timespec_equal(&inode
->i_mtime
, &now
))
1657 if (!timespec_equal(&inode
->i_ctime
, &now
))
1660 if (IS_I_VERSION(inode
))
1661 sync_it
|= S_VERSION
;
1666 /* Finally allowed to write? Takes lock. */
1667 if (__mnt_want_write_file(file
))
1670 ret
= update_time(inode
, &now
, sync_it
);
1671 __mnt_drop_write_file(file
);
1675 EXPORT_SYMBOL(file_update_time
);
1677 int inode_needs_sync(struct inode
*inode
)
1681 if (S_ISDIR(inode
->i_mode
) && IS_DIRSYNC(inode
))
1685 EXPORT_SYMBOL(inode_needs_sync
);
1688 * If we try to find an inode in the inode hash while it is being
1689 * deleted, we have to wait until the filesystem completes its
1690 * deletion before reporting that it isn't found. This function waits
1691 * until the deletion _might_ have completed. Callers are responsible
1692 * to recheck inode state.
1694 * It doesn't matter if I_NEW is not set initially, a call to
1695 * wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list
1698 static void __wait_on_freeing_inode(struct inode
*inode
)
1700 wait_queue_head_t
*wq
;
1701 DEFINE_WAIT_BIT(wait
, &inode
->i_state
, __I_NEW
);
1702 wq
= bit_waitqueue(&inode
->i_state
, __I_NEW
);
1703 prepare_to_wait(wq
, &wait
.wait
, TASK_UNINTERRUPTIBLE
);
1704 spin_unlock(&inode
->i_lock
);
1705 spin_unlock(&inode_hash_lock
);
1707 finish_wait(wq
, &wait
.wait
);
1708 spin_lock(&inode_hash_lock
);
1711 static __initdata
unsigned long ihash_entries
;
1712 static int __init
set_ihash_entries(char *str
)
1716 ihash_entries
= simple_strtoul(str
, &str
, 0);
1719 __setup("ihash_entries=", set_ihash_entries
);
1722 * Initialize the waitqueues and inode hash table.
1724 void __init
inode_init_early(void)
1728 /* If hashes are distributed across NUMA nodes, defer
1729 * hash allocation until vmalloc space is available.
1735 alloc_large_system_hash("Inode-cache",
1736 sizeof(struct hlist_head
),
1745 for (loop
= 0; loop
< (1U << i_hash_shift
); loop
++)
1746 INIT_HLIST_HEAD(&inode_hashtable
[loop
]);
1749 void __init
inode_init(void)
1753 /* inode slab cache */
1754 inode_cachep
= kmem_cache_create("inode_cache",
1755 sizeof(struct inode
),
1757 (SLAB_RECLAIM_ACCOUNT
|SLAB_PANIC
|
1761 /* Hash may have been set up in inode_init_early */
1766 alloc_large_system_hash("Inode-cache",
1767 sizeof(struct hlist_head
),
1776 for (loop
= 0; loop
< (1U << i_hash_shift
); loop
++)
1777 INIT_HLIST_HEAD(&inode_hashtable
[loop
]);
1780 void init_special_inode(struct inode
*inode
, umode_t mode
, dev_t rdev
)
1782 inode
->i_mode
= mode
;
1783 if (S_ISCHR(mode
)) {
1784 inode
->i_fop
= &def_chr_fops
;
1785 inode
->i_rdev
= rdev
;
1786 } else if (S_ISBLK(mode
)) {
1787 inode
->i_fop
= &def_blk_fops
;
1788 inode
->i_rdev
= rdev
;
1789 } else if (S_ISFIFO(mode
))
1790 inode
->i_fop
= &pipefifo_fops
;
1791 else if (S_ISSOCK(mode
))
1792 ; /* leave it no_open_fops */
1794 printk(KERN_DEBUG
"init_special_inode: bogus i_mode (%o) for"
1795 " inode %s:%lu\n", mode
, inode
->i_sb
->s_id
,
1798 EXPORT_SYMBOL(init_special_inode
);
1801 * inode_init_owner - Init uid,gid,mode for new inode according to posix standards
1803 * @dir: Directory inode
1804 * @mode: mode of the new inode
1806 void inode_init_owner(struct inode
*inode
, const struct inode
*dir
,
1809 inode
->i_uid
= current_fsuid();
1810 if (dir
&& dir
->i_mode
& S_ISGID
) {
1811 inode
->i_gid
= dir
->i_gid
;
1815 inode
->i_gid
= current_fsgid();
1816 inode
->i_mode
= mode
;
1818 EXPORT_SYMBOL(inode_init_owner
);
1821 * inode_owner_or_capable - check current task permissions to inode
1822 * @inode: inode being checked
1824 * Return true if current either has CAP_FOWNER in a namespace with the
1825 * inode owner uid mapped, or owns the file.
1827 bool inode_owner_or_capable(const struct inode
*inode
)
1829 struct user_namespace
*ns
;
1831 if (uid_eq(current_fsuid(), inode
->i_uid
))
1834 ns
= current_user_ns();
1835 if (ns_capable(ns
, CAP_FOWNER
) && kuid_has_mapping(ns
, inode
->i_uid
))
1839 EXPORT_SYMBOL(inode_owner_or_capable
);
1842 * Direct i/o helper functions
1844 static void __inode_dio_wait(struct inode
*inode
)
1846 wait_queue_head_t
*wq
= bit_waitqueue(&inode
->i_state
, __I_DIO_WAKEUP
);
1847 DEFINE_WAIT_BIT(q
, &inode
->i_state
, __I_DIO_WAKEUP
);
1850 prepare_to_wait(wq
, &q
.wait
, TASK_UNINTERRUPTIBLE
);
1851 if (atomic_read(&inode
->i_dio_count
))
1853 } while (atomic_read(&inode
->i_dio_count
));
1854 finish_wait(wq
, &q
.wait
);
1858 * inode_dio_wait - wait for outstanding DIO requests to finish
1859 * @inode: inode to wait for
1861 * Waits for all pending direct I/O requests to finish so that we can
1862 * proceed with a truncate or equivalent operation.
1864 * Must be called under a lock that serializes taking new references
1865 * to i_dio_count, usually by inode->i_mutex.
1867 void inode_dio_wait(struct inode
*inode
)
1869 if (atomic_read(&inode
->i_dio_count
))
1870 __inode_dio_wait(inode
);
1872 EXPORT_SYMBOL(inode_dio_wait
);
1875 * inode_dio_done - signal finish of a direct I/O requests
1876 * @inode: inode the direct I/O happens on
1878 * This is called once we've finished processing a direct I/O request,
1879 * and is used to wake up callers waiting for direct I/O to be quiesced.
1881 void inode_dio_done(struct inode
*inode
)
1883 if (atomic_dec_and_test(&inode
->i_dio_count
))
1884 wake_up_bit(&inode
->i_state
, __I_DIO_WAKEUP
);
1886 EXPORT_SYMBOL(inode_dio_done
);
1889 * inode_set_flags - atomically set some inode flags
1891 * Note: the caller should be holding i_mutex, or else be sure that
1892 * they have exclusive access to the inode structure (i.e., while the
1893 * inode is being instantiated). The reason for the cmpxchg() loop
1894 * --- which wouldn't be necessary if all code paths which modify
1895 * i_flags actually followed this rule, is that there is at least one
1896 * code path which doesn't today --- for example,
1897 * __generic_file_aio_write() calls file_remove_suid() without holding
1898 * i_mutex --- so we use cmpxchg() out of an abundance of caution.
1900 * In the long run, i_mutex is overkill, and we should probably look
1901 * at using the i_lock spinlock to protect i_flags, and then make sure
1902 * it is so documented in include/linux/fs.h and that all code follows
1903 * the locking convention!!
1905 void inode_set_flags(struct inode
*inode
, unsigned int flags
,
1908 unsigned int old_flags
, new_flags
;
1910 WARN_ON_ONCE(flags
& ~mask
);
1912 old_flags
= ACCESS_ONCE(inode
->i_flags
);
1913 new_flags
= (old_flags
& ~mask
) | flags
;
1914 } while (unlikely(cmpxchg(&inode
->i_flags
, old_flags
,
1915 new_flags
) != old_flags
));
1917 EXPORT_SYMBOL(inode_set_flags
);