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>
21 #include <trace/events/writeback.h>
25 * Inode locking rules:
27 * inode->i_lock protects:
28 * inode->i_state, inode->i_hash, __iget()
29 * Inode LRU list locks protect:
30 * inode->i_sb->s_inode_lru, inode->i_lru
31 * inode->i_sb->s_inode_list_lock protects:
32 * inode->i_sb->s_inodes, inode->i_sb_list
33 * bdi->wb.list_lock protects:
34 * bdi->wb.b_{dirty,io,more_io,dirty_time}, inode->i_io_list
35 * inode_hash_lock protects:
36 * inode_hashtable, inode->i_hash
40 * inode->i_sb->s_inode_list_lock
42 * Inode LRU list locks
48 * inode->i_sb->s_inode_list_lock
55 static unsigned int i_hash_mask __read_mostly
;
56 static unsigned int i_hash_shift __read_mostly
;
57 static struct hlist_head
*inode_hashtable __read_mostly
;
58 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(inode_hash_lock
);
61 * Empty aops. Can be used for the cases where the user does not
62 * define any of the address_space operations.
64 const struct address_space_operations empty_aops
= {
66 EXPORT_SYMBOL(empty_aops
);
69 * Statistics gathering..
71 struct inodes_stat_t inodes_stat
;
73 static DEFINE_PER_CPU(unsigned long, nr_inodes
);
74 static DEFINE_PER_CPU(unsigned long, nr_unused
);
76 static struct kmem_cache
*inode_cachep __read_mostly
;
78 static long get_nr_inodes(void)
82 for_each_possible_cpu(i
)
83 sum
+= per_cpu(nr_inodes
, i
);
84 return sum
< 0 ? 0 : sum
;
87 static inline long get_nr_inodes_unused(void)
91 for_each_possible_cpu(i
)
92 sum
+= per_cpu(nr_unused
, i
);
93 return sum
< 0 ? 0 : sum
;
96 long get_nr_dirty_inodes(void)
98 /* not actually dirty inodes, but a wild approximation */
99 long nr_dirty
= get_nr_inodes() - get_nr_inodes_unused();
100 return nr_dirty
> 0 ? nr_dirty
: 0;
104 * Handle nr_inode sysctl
107 int proc_nr_inodes(struct ctl_table
*table
, int write
,
108 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
110 inodes_stat
.nr_inodes
= get_nr_inodes();
111 inodes_stat
.nr_unused
= get_nr_inodes_unused();
112 return proc_doulongvec_minmax(table
, write
, buffer
, lenp
, ppos
);
116 static int no_open(struct inode
*inode
, struct file
*file
)
122 * inode_init_always - perform inode structure intialisation
123 * @sb: superblock inode belongs to
124 * @inode: inode to initialise
126 * These are initializations that need to be done on every inode
127 * allocation as the fields are not initialised by slab allocation.
129 int inode_init_always(struct super_block
*sb
, struct inode
*inode
)
131 static const struct inode_operations empty_iops
;
132 static const struct file_operations no_open_fops
= {.open
= no_open
};
133 struct address_space
*const mapping
= &inode
->i_data
;
136 inode
->i_blkbits
= sb
->s_blocksize_bits
;
138 atomic_set(&inode
->i_count
, 1);
139 inode
->i_op
= &empty_iops
;
140 inode
->i_fop
= &no_open_fops
;
141 inode
->__i_nlink
= 1;
142 inode
->i_opflags
= 0;
143 i_uid_write(inode
, 0);
144 i_gid_write(inode
, 0);
145 atomic_set(&inode
->i_writecount
, 0);
149 inode
->i_generation
= 0;
150 inode
->i_pipe
= NULL
;
151 inode
->i_bdev
= NULL
;
152 inode
->i_cdev
= NULL
;
153 inode
->i_link
= 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 inode_detach_wb(inode
);
226 security_inode_free(inode
);
227 fsnotify_inode_delete(inode
);
228 locks_free_lock_context(inode
->i_flctx
);
229 if (!inode
->i_nlink
) {
230 WARN_ON(atomic_long_read(&inode
->i_sb
->s_remove_count
) == 0);
231 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
234 #ifdef CONFIG_FS_POSIX_ACL
235 if (inode
->i_acl
&& inode
->i_acl
!= ACL_NOT_CACHED
)
236 posix_acl_release(inode
->i_acl
);
237 if (inode
->i_default_acl
&& inode
->i_default_acl
!= ACL_NOT_CACHED
)
238 posix_acl_release(inode
->i_default_acl
);
240 this_cpu_dec(nr_inodes
);
242 EXPORT_SYMBOL(__destroy_inode
);
244 static void i_callback(struct rcu_head
*head
)
246 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
247 kmem_cache_free(inode_cachep
, inode
);
250 static void destroy_inode(struct inode
*inode
)
252 BUG_ON(!list_empty(&inode
->i_lru
));
253 __destroy_inode(inode
);
254 if (inode
->i_sb
->s_op
->destroy_inode
)
255 inode
->i_sb
->s_op
->destroy_inode(inode
);
257 call_rcu(&inode
->i_rcu
, i_callback
);
261 * drop_nlink - directly drop an inode's link count
264 * This is a low-level filesystem helper to replace any
265 * direct filesystem manipulation of i_nlink. In cases
266 * where we are attempting to track writes to the
267 * filesystem, a decrement to zero means an imminent
268 * write when the file is truncated and actually unlinked
271 void drop_nlink(struct inode
*inode
)
273 WARN_ON(inode
->i_nlink
== 0);
276 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
278 EXPORT_SYMBOL(drop_nlink
);
281 * clear_nlink - directly zero an inode's link count
284 * This is a low-level filesystem helper to replace any
285 * direct filesystem manipulation of i_nlink. See
286 * drop_nlink() for why we care about i_nlink hitting zero.
288 void clear_nlink(struct inode
*inode
)
290 if (inode
->i_nlink
) {
291 inode
->__i_nlink
= 0;
292 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
295 EXPORT_SYMBOL(clear_nlink
);
298 * set_nlink - directly set an inode's link count
300 * @nlink: new nlink (should be non-zero)
302 * This is a low-level filesystem helper to replace any
303 * direct filesystem manipulation of i_nlink.
305 void set_nlink(struct inode
*inode
, unsigned int nlink
)
310 /* Yes, some filesystems do change nlink from zero to one */
311 if (inode
->i_nlink
== 0)
312 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
314 inode
->__i_nlink
= nlink
;
317 EXPORT_SYMBOL(set_nlink
);
320 * inc_nlink - directly increment an inode's link count
323 * This is a low-level filesystem helper to replace any
324 * direct filesystem manipulation of i_nlink. Currently,
325 * it is only here for parity with dec_nlink().
327 void inc_nlink(struct inode
*inode
)
329 if (unlikely(inode
->i_nlink
== 0)) {
330 WARN_ON(!(inode
->i_state
& I_LINKABLE
));
331 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
336 EXPORT_SYMBOL(inc_nlink
);
338 void address_space_init_once(struct address_space
*mapping
)
340 memset(mapping
, 0, sizeof(*mapping
));
341 INIT_RADIX_TREE(&mapping
->page_tree
, GFP_ATOMIC
);
342 spin_lock_init(&mapping
->tree_lock
);
343 init_rwsem(&mapping
->i_mmap_rwsem
);
344 INIT_LIST_HEAD(&mapping
->private_list
);
345 spin_lock_init(&mapping
->private_lock
);
346 mapping
->i_mmap
= RB_ROOT
;
348 EXPORT_SYMBOL(address_space_init_once
);
351 * These are initializations that only need to be done
352 * once, because the fields are idempotent across use
353 * of the inode, so let the slab aware of that.
355 void inode_init_once(struct inode
*inode
)
357 memset(inode
, 0, sizeof(*inode
));
358 INIT_HLIST_NODE(&inode
->i_hash
);
359 INIT_LIST_HEAD(&inode
->i_devices
);
360 INIT_LIST_HEAD(&inode
->i_io_list
);
361 INIT_LIST_HEAD(&inode
->i_lru
);
362 address_space_init_once(&inode
->i_data
);
363 i_size_ordered_init(inode
);
364 #ifdef CONFIG_FSNOTIFY
365 INIT_HLIST_HEAD(&inode
->i_fsnotify_marks
);
368 EXPORT_SYMBOL(inode_init_once
);
370 static void init_once(void *foo
)
372 struct inode
*inode
= (struct inode
*) foo
;
374 inode_init_once(inode
);
378 * inode->i_lock must be held
380 void __iget(struct inode
*inode
)
382 atomic_inc(&inode
->i_count
);
386 * get additional reference to inode; caller must already hold one.
388 void ihold(struct inode
*inode
)
390 WARN_ON(atomic_inc_return(&inode
->i_count
) < 2);
392 EXPORT_SYMBOL(ihold
);
394 static void inode_lru_list_add(struct inode
*inode
)
396 if (list_lru_add(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
397 this_cpu_inc(nr_unused
);
401 * Add inode to LRU if needed (inode is unused and clean).
403 * Needs inode->i_lock held.
405 void inode_add_lru(struct inode
*inode
)
407 if (!(inode
->i_state
& (I_DIRTY_ALL
| I_SYNC
|
408 I_FREEING
| I_WILL_FREE
)) &&
409 !atomic_read(&inode
->i_count
) && inode
->i_sb
->s_flags
& MS_ACTIVE
)
410 inode_lru_list_add(inode
);
414 static void inode_lru_list_del(struct inode
*inode
)
417 if (list_lru_del(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
418 this_cpu_dec(nr_unused
);
422 * inode_sb_list_add - add inode to the superblock list of inodes
423 * @inode: inode to add
425 void inode_sb_list_add(struct inode
*inode
)
427 spin_lock(&inode
->i_sb
->s_inode_list_lock
);
428 list_add(&inode
->i_sb_list
, &inode
->i_sb
->s_inodes
);
429 spin_unlock(&inode
->i_sb
->s_inode_list_lock
);
431 EXPORT_SYMBOL_GPL(inode_sb_list_add
);
433 static inline void inode_sb_list_del(struct inode
*inode
)
435 if (!list_empty(&inode
->i_sb_list
)) {
436 spin_lock(&inode
->i_sb
->s_inode_list_lock
);
437 list_del_init(&inode
->i_sb_list
);
438 spin_unlock(&inode
->i_sb
->s_inode_list_lock
);
442 static unsigned long hash(struct super_block
*sb
, unsigned long hashval
)
446 tmp
= (hashval
* (unsigned long)sb
) ^ (GOLDEN_RATIO_PRIME
+ hashval
) /
448 tmp
= tmp
^ ((tmp
^ GOLDEN_RATIO_PRIME
) >> i_hash_shift
);
449 return tmp
& i_hash_mask
;
453 * __insert_inode_hash - hash an inode
454 * @inode: unhashed inode
455 * @hashval: unsigned long value used to locate this object in the
458 * Add an inode to the inode hash for this superblock.
460 void __insert_inode_hash(struct inode
*inode
, unsigned long hashval
)
462 struct hlist_head
*b
= inode_hashtable
+ hash(inode
->i_sb
, hashval
);
464 spin_lock(&inode_hash_lock
);
465 spin_lock(&inode
->i_lock
);
466 hlist_add_head(&inode
->i_hash
, b
);
467 spin_unlock(&inode
->i_lock
);
468 spin_unlock(&inode_hash_lock
);
470 EXPORT_SYMBOL(__insert_inode_hash
);
473 * __remove_inode_hash - remove an inode from the hash
474 * @inode: inode to unhash
476 * Remove an inode from the superblock.
478 void __remove_inode_hash(struct inode
*inode
)
480 spin_lock(&inode_hash_lock
);
481 spin_lock(&inode
->i_lock
);
482 hlist_del_init(&inode
->i_hash
);
483 spin_unlock(&inode
->i_lock
);
484 spin_unlock(&inode_hash_lock
);
486 EXPORT_SYMBOL(__remove_inode_hash
);
488 void clear_inode(struct inode
*inode
)
492 * We have to cycle tree_lock here because reclaim can be still in the
493 * process of removing the last page (in __delete_from_page_cache())
494 * and we must not free mapping under it.
496 spin_lock_irq(&inode
->i_data
.tree_lock
);
497 BUG_ON(inode
->i_data
.nrpages
);
498 BUG_ON(inode
->i_data
.nrshadows
);
499 spin_unlock_irq(&inode
->i_data
.tree_lock
);
500 BUG_ON(!list_empty(&inode
->i_data
.private_list
));
501 BUG_ON(!(inode
->i_state
& I_FREEING
));
502 BUG_ON(inode
->i_state
& I_CLEAR
);
503 /* don't need i_lock here, no concurrent mods to i_state */
504 inode
->i_state
= I_FREEING
| I_CLEAR
;
506 EXPORT_SYMBOL(clear_inode
);
509 * Free the inode passed in, removing it from the lists it is still connected
510 * to. We remove any pages still attached to the inode and wait for any IO that
511 * is still in progress before finally destroying the inode.
513 * An inode must already be marked I_FREEING so that we avoid the inode being
514 * moved back onto lists if we race with other code that manipulates the lists
515 * (e.g. writeback_single_inode). The caller is responsible for setting this.
517 * An inode must already be removed from the LRU list before being evicted from
518 * the cache. This should occur atomically with setting the I_FREEING state
519 * flag, so no inodes here should ever be on the LRU when being evicted.
521 static void evict(struct inode
*inode
)
523 const struct super_operations
*op
= inode
->i_sb
->s_op
;
525 BUG_ON(!(inode
->i_state
& I_FREEING
));
526 BUG_ON(!list_empty(&inode
->i_lru
));
528 if (!list_empty(&inode
->i_io_list
))
529 inode_io_list_del(inode
);
531 inode_sb_list_del(inode
);
534 * Wait for flusher thread to be done with the inode so that filesystem
535 * does not start destroying it while writeback is still running. Since
536 * the inode has I_FREEING set, flusher thread won't start new work on
537 * the inode. We just have to wait for running writeback to finish.
539 inode_wait_for_writeback(inode
);
541 if (op
->evict_inode
) {
542 op
->evict_inode(inode
);
544 truncate_inode_pages_final(&inode
->i_data
);
547 if (S_ISBLK(inode
->i_mode
) && inode
->i_bdev
)
549 if (S_ISCHR(inode
->i_mode
) && inode
->i_cdev
)
552 remove_inode_hash(inode
);
554 spin_lock(&inode
->i_lock
);
555 wake_up_bit(&inode
->i_state
, __I_NEW
);
556 BUG_ON(inode
->i_state
!= (I_FREEING
| I_CLEAR
));
557 spin_unlock(&inode
->i_lock
);
559 destroy_inode(inode
);
563 * dispose_list - dispose of the contents of a local list
564 * @head: the head of the list to free
566 * Dispose-list gets a local list with local inodes in it, so it doesn't
567 * need to worry about list corruption and SMP locks.
569 static void dispose_list(struct list_head
*head
)
571 while (!list_empty(head
)) {
574 inode
= list_first_entry(head
, struct inode
, i_lru
);
575 list_del_init(&inode
->i_lru
);
583 * evict_inodes - evict all evictable inodes for a superblock
584 * @sb: superblock to operate on
586 * Make sure that no inodes with zero refcount are retained. This is
587 * called by superblock shutdown after having MS_ACTIVE flag removed,
588 * so any inode reaching zero refcount during or after that call will
589 * be immediately evicted.
591 void evict_inodes(struct super_block
*sb
)
593 struct inode
*inode
, *next
;
597 spin_lock(&sb
->s_inode_list_lock
);
598 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
599 if (atomic_read(&inode
->i_count
))
602 spin_lock(&inode
->i_lock
);
603 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
604 spin_unlock(&inode
->i_lock
);
608 inode
->i_state
|= I_FREEING
;
609 inode_lru_list_del(inode
);
610 spin_unlock(&inode
->i_lock
);
611 list_add(&inode
->i_lru
, &dispose
);
614 * We can have a ton of inodes to evict at unmount time given
615 * enough memory, check to see if we need to go to sleep for a
616 * bit so we don't livelock.
618 if (need_resched()) {
619 spin_unlock(&sb
->s_inode_list_lock
);
621 dispose_list(&dispose
);
625 spin_unlock(&sb
->s_inode_list_lock
);
627 dispose_list(&dispose
);
631 * invalidate_inodes - attempt to free all inodes on a superblock
632 * @sb: superblock to operate on
633 * @kill_dirty: flag to guide handling of dirty inodes
635 * Attempts to free all inodes for a given superblock. If there were any
636 * busy inodes return a non-zero value, else zero.
637 * If @kill_dirty is set, discard dirty inodes too, otherwise treat
640 int invalidate_inodes(struct super_block
*sb
, bool kill_dirty
)
643 struct inode
*inode
, *next
;
646 spin_lock(&sb
->s_inode_list_lock
);
647 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
648 spin_lock(&inode
->i_lock
);
649 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
650 spin_unlock(&inode
->i_lock
);
653 if (inode
->i_state
& I_DIRTY_ALL
&& !kill_dirty
) {
654 spin_unlock(&inode
->i_lock
);
658 if (atomic_read(&inode
->i_count
)) {
659 spin_unlock(&inode
->i_lock
);
664 inode
->i_state
|= I_FREEING
;
665 inode_lru_list_del(inode
);
666 spin_unlock(&inode
->i_lock
);
667 list_add(&inode
->i_lru
, &dispose
);
669 spin_unlock(&sb
->s_inode_list_lock
);
671 dispose_list(&dispose
);
677 * Isolate the inode from the LRU in preparation for freeing it.
679 * Any inodes which are pinned purely because of attached pagecache have their
680 * pagecache removed. If the inode has metadata buffers attached to
681 * mapping->private_list then try to remove them.
683 * If the inode has the I_REFERENCED flag set, then it means that it has been
684 * used recently - the flag is set in iput_final(). When we encounter such an
685 * inode, clear the flag and move it to the back of the LRU so it gets another
686 * pass through the LRU before it gets reclaimed. This is necessary because of
687 * the fact we are doing lazy LRU updates to minimise lock contention so the
688 * LRU does not have strict ordering. Hence we don't want to reclaim inodes
689 * with this flag set because they are the inodes that are out of order.
691 static enum lru_status
inode_lru_isolate(struct list_head
*item
,
692 struct list_lru_one
*lru
, spinlock_t
*lru_lock
, void *arg
)
694 struct list_head
*freeable
= arg
;
695 struct inode
*inode
= container_of(item
, struct inode
, i_lru
);
698 * we are inverting the lru lock/inode->i_lock here, so use a trylock.
699 * If we fail to get the lock, just skip it.
701 if (!spin_trylock(&inode
->i_lock
))
705 * Referenced or dirty inodes are still in use. Give them another pass
706 * through the LRU as we canot reclaim them now.
708 if (atomic_read(&inode
->i_count
) ||
709 (inode
->i_state
& ~I_REFERENCED
)) {
710 list_lru_isolate(lru
, &inode
->i_lru
);
711 spin_unlock(&inode
->i_lock
);
712 this_cpu_dec(nr_unused
);
716 /* recently referenced inodes get one more pass */
717 if (inode
->i_state
& I_REFERENCED
) {
718 inode
->i_state
&= ~I_REFERENCED
;
719 spin_unlock(&inode
->i_lock
);
723 if (inode_has_buffers(inode
) || inode
->i_data
.nrpages
) {
725 spin_unlock(&inode
->i_lock
);
726 spin_unlock(lru_lock
);
727 if (remove_inode_buffers(inode
)) {
729 reap
= invalidate_mapping_pages(&inode
->i_data
, 0, -1);
730 if (current_is_kswapd())
731 __count_vm_events(KSWAPD_INODESTEAL
, reap
);
733 __count_vm_events(PGINODESTEAL
, reap
);
734 if (current
->reclaim_state
)
735 current
->reclaim_state
->reclaimed_slab
+= reap
;
742 WARN_ON(inode
->i_state
& I_NEW
);
743 inode
->i_state
|= I_FREEING
;
744 list_lru_isolate_move(lru
, &inode
->i_lru
, freeable
);
745 spin_unlock(&inode
->i_lock
);
747 this_cpu_dec(nr_unused
);
752 * Walk the superblock inode LRU for freeable inodes and attempt to free them.
753 * This is called from the superblock shrinker function with a number of inodes
754 * to trim from the LRU. Inodes to be freed are moved to a temporary list and
755 * then are freed outside inode_lock by dispose_list().
757 long prune_icache_sb(struct super_block
*sb
, struct shrink_control
*sc
)
762 freed
= list_lru_shrink_walk(&sb
->s_inode_lru
, sc
,
763 inode_lru_isolate
, &freeable
);
764 dispose_list(&freeable
);
768 static void __wait_on_freeing_inode(struct inode
*inode
);
770 * Called with the inode lock held.
772 static struct inode
*find_inode(struct super_block
*sb
,
773 struct hlist_head
*head
,
774 int (*test
)(struct inode
*, void *),
777 struct inode
*inode
= NULL
;
780 hlist_for_each_entry(inode
, head
, i_hash
) {
781 if (inode
->i_sb
!= sb
)
783 if (!test(inode
, data
))
785 spin_lock(&inode
->i_lock
);
786 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
787 __wait_on_freeing_inode(inode
);
791 spin_unlock(&inode
->i_lock
);
798 * find_inode_fast is the fast path version of find_inode, see the comment at
799 * iget_locked for details.
801 static struct inode
*find_inode_fast(struct super_block
*sb
,
802 struct hlist_head
*head
, unsigned long ino
)
804 struct inode
*inode
= NULL
;
807 hlist_for_each_entry(inode
, head
, i_hash
) {
808 if (inode
->i_ino
!= ino
)
810 if (inode
->i_sb
!= sb
)
812 spin_lock(&inode
->i_lock
);
813 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
814 __wait_on_freeing_inode(inode
);
818 spin_unlock(&inode
->i_lock
);
825 * Each cpu owns a range of LAST_INO_BATCH numbers.
826 * 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations,
827 * to renew the exhausted range.
829 * This does not significantly increase overflow rate because every CPU can
830 * consume at most LAST_INO_BATCH-1 unused inode numbers. So there is
831 * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the
832 * 2^32 range, and is a worst-case. Even a 50% wastage would only increase
833 * overflow rate by 2x, which does not seem too significant.
835 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
836 * error if st_ino won't fit in target struct field. Use 32bit counter
837 * here to attempt to avoid that.
839 #define LAST_INO_BATCH 1024
840 static DEFINE_PER_CPU(unsigned int, last_ino
);
842 unsigned int get_next_ino(void)
844 unsigned int *p
= &get_cpu_var(last_ino
);
845 unsigned int res
= *p
;
848 if (unlikely((res
& (LAST_INO_BATCH
-1)) == 0)) {
849 static atomic_t shared_last_ino
;
850 int next
= atomic_add_return(LAST_INO_BATCH
, &shared_last_ino
);
852 res
= next
- LAST_INO_BATCH
;
857 /* get_next_ino should not provide a 0 inode number */
861 put_cpu_var(last_ino
);
864 EXPORT_SYMBOL(get_next_ino
);
867 * new_inode_pseudo - obtain an inode
870 * Allocates a new inode for given superblock.
871 * Inode wont be chained in superblock s_inodes list
873 * - fs can't be unmount
874 * - quotas, fsnotify, writeback can't work
876 struct inode
*new_inode_pseudo(struct super_block
*sb
)
878 struct inode
*inode
= alloc_inode(sb
);
881 spin_lock(&inode
->i_lock
);
883 spin_unlock(&inode
->i_lock
);
884 INIT_LIST_HEAD(&inode
->i_sb_list
);
890 * new_inode - obtain an inode
893 * Allocates a new inode for given superblock. The default gfp_mask
894 * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE.
895 * If HIGHMEM pages are unsuitable or it is known that pages allocated
896 * for the page cache are not reclaimable or migratable,
897 * mapping_set_gfp_mask() must be called with suitable flags on the
898 * newly created inode's mapping
901 struct inode
*new_inode(struct super_block
*sb
)
905 spin_lock_prefetch(&sb
->s_inode_list_lock
);
907 inode
= new_inode_pseudo(sb
);
909 inode_sb_list_add(inode
);
912 EXPORT_SYMBOL(new_inode
);
914 #ifdef CONFIG_DEBUG_LOCK_ALLOC
915 void lockdep_annotate_inode_mutex_key(struct inode
*inode
)
917 if (S_ISDIR(inode
->i_mode
)) {
918 struct file_system_type
*type
= inode
->i_sb
->s_type
;
920 /* Set new key only if filesystem hasn't already changed it */
921 if (lockdep_match_class(&inode
->i_mutex
, &type
->i_mutex_key
)) {
923 * ensure nobody is actually holding i_mutex
925 mutex_destroy(&inode
->i_mutex
);
926 mutex_init(&inode
->i_mutex
);
927 lockdep_set_class(&inode
->i_mutex
,
928 &type
->i_mutex_dir_key
);
932 EXPORT_SYMBOL(lockdep_annotate_inode_mutex_key
);
936 * unlock_new_inode - clear the I_NEW state and wake up any waiters
937 * @inode: new inode to unlock
939 * Called when the inode is fully initialised to clear the new state of the
940 * inode and wake up anyone waiting for the inode to finish initialisation.
942 void unlock_new_inode(struct inode
*inode
)
944 lockdep_annotate_inode_mutex_key(inode
);
945 spin_lock(&inode
->i_lock
);
946 WARN_ON(!(inode
->i_state
& I_NEW
));
947 inode
->i_state
&= ~I_NEW
;
949 wake_up_bit(&inode
->i_state
, __I_NEW
);
950 spin_unlock(&inode
->i_lock
);
952 EXPORT_SYMBOL(unlock_new_inode
);
955 * lock_two_nondirectories - take two i_mutexes on non-directory objects
957 * Lock any non-NULL argument that is not a directory.
958 * Zero, one or two objects may be locked by this function.
960 * @inode1: first inode to lock
961 * @inode2: second inode to lock
963 void lock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
966 swap(inode1
, inode2
);
968 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
969 mutex_lock(&inode1
->i_mutex
);
970 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
971 mutex_lock_nested(&inode2
->i_mutex
, I_MUTEX_NONDIR2
);
973 EXPORT_SYMBOL(lock_two_nondirectories
);
976 * unlock_two_nondirectories - release locks from lock_two_nondirectories()
977 * @inode1: first inode to unlock
978 * @inode2: second inode to unlock
980 void unlock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
982 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
983 mutex_unlock(&inode1
->i_mutex
);
984 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
985 mutex_unlock(&inode2
->i_mutex
);
987 EXPORT_SYMBOL(unlock_two_nondirectories
);
990 * iget5_locked - obtain an inode from a mounted file system
991 * @sb: super block of file system
992 * @hashval: hash value (usually inode number) to get
993 * @test: callback used for comparisons between inodes
994 * @set: callback used to initialize a new struct inode
995 * @data: opaque data pointer to pass to @test and @set
997 * Search for the inode specified by @hashval and @data in the inode cache,
998 * and if present it is return it with an increased reference count. This is
999 * a generalized version of iget_locked() for file systems where the inode
1000 * number is not sufficient for unique identification of an inode.
1002 * If the inode is not in cache, allocate a new inode and return it locked,
1003 * hashed, and with the I_NEW flag set. The file system gets to fill it in
1004 * before unlocking it via unlock_new_inode().
1006 * Note both @test and @set are called with the inode_hash_lock held, so can't
1009 struct inode
*iget5_locked(struct super_block
*sb
, unsigned long hashval
,
1010 int (*test
)(struct inode
*, void *),
1011 int (*set
)(struct inode
*, void *), void *data
)
1013 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1014 struct inode
*inode
;
1016 spin_lock(&inode_hash_lock
);
1017 inode
= find_inode(sb
, head
, test
, data
);
1018 spin_unlock(&inode_hash_lock
);
1021 wait_on_inode(inode
);
1025 inode
= alloc_inode(sb
);
1029 spin_lock(&inode_hash_lock
);
1030 /* We released the lock, so.. */
1031 old
= find_inode(sb
, head
, test
, data
);
1033 if (set(inode
, data
))
1036 spin_lock(&inode
->i_lock
);
1037 inode
->i_state
= I_NEW
;
1038 hlist_add_head(&inode
->i_hash
, head
);
1039 spin_unlock(&inode
->i_lock
);
1040 inode_sb_list_add(inode
);
1041 spin_unlock(&inode_hash_lock
);
1043 /* Return the locked inode with I_NEW set, the
1044 * caller is responsible for filling in the contents
1050 * Uhhuh, somebody else created the same inode under
1051 * us. Use the old inode instead of the one we just
1054 spin_unlock(&inode_hash_lock
);
1055 destroy_inode(inode
);
1057 wait_on_inode(inode
);
1062 spin_unlock(&inode_hash_lock
);
1063 destroy_inode(inode
);
1066 EXPORT_SYMBOL(iget5_locked
);
1069 * iget_locked - obtain an inode from a mounted file system
1070 * @sb: super block of file system
1071 * @ino: inode number to get
1073 * Search for the inode specified by @ino in the inode cache and if present
1074 * return it with an increased reference count. This is for file systems
1075 * where the inode number is sufficient for unique identification of an inode.
1077 * If the inode is not in cache, allocate a new inode and return it locked,
1078 * hashed, and with the I_NEW flag set. The file system gets to fill it in
1079 * before unlocking it via unlock_new_inode().
1081 struct inode
*iget_locked(struct super_block
*sb
, unsigned long ino
)
1083 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1084 struct inode
*inode
;
1086 spin_lock(&inode_hash_lock
);
1087 inode
= find_inode_fast(sb
, head
, ino
);
1088 spin_unlock(&inode_hash_lock
);
1090 wait_on_inode(inode
);
1094 inode
= alloc_inode(sb
);
1098 spin_lock(&inode_hash_lock
);
1099 /* We released the lock, so.. */
1100 old
= find_inode_fast(sb
, head
, ino
);
1103 spin_lock(&inode
->i_lock
);
1104 inode
->i_state
= I_NEW
;
1105 hlist_add_head(&inode
->i_hash
, head
);
1106 spin_unlock(&inode
->i_lock
);
1107 inode_sb_list_add(inode
);
1108 spin_unlock(&inode_hash_lock
);
1110 /* Return the locked inode with I_NEW set, the
1111 * caller is responsible for filling in the contents
1117 * Uhhuh, somebody else created the same inode under
1118 * us. Use the old inode instead of the one we just
1121 spin_unlock(&inode_hash_lock
);
1122 destroy_inode(inode
);
1124 wait_on_inode(inode
);
1128 EXPORT_SYMBOL(iget_locked
);
1131 * search the inode cache for a matching inode number.
1132 * If we find one, then the inode number we are trying to
1133 * allocate is not unique and so we should not use it.
1135 * Returns 1 if the inode number is unique, 0 if it is not.
1137 static int test_inode_iunique(struct super_block
*sb
, unsigned long ino
)
1139 struct hlist_head
*b
= inode_hashtable
+ hash(sb
, ino
);
1140 struct inode
*inode
;
1142 spin_lock(&inode_hash_lock
);
1143 hlist_for_each_entry(inode
, b
, i_hash
) {
1144 if (inode
->i_ino
== ino
&& inode
->i_sb
== sb
) {
1145 spin_unlock(&inode_hash_lock
);
1149 spin_unlock(&inode_hash_lock
);
1155 * iunique - get a unique inode number
1157 * @max_reserved: highest reserved inode number
1159 * Obtain an inode number that is unique on the system for a given
1160 * superblock. This is used by file systems that have no natural
1161 * permanent inode numbering system. An inode number is returned that
1162 * is higher than the reserved limit but unique.
1165 * With a large number of inodes live on the file system this function
1166 * currently becomes quite slow.
1168 ino_t
iunique(struct super_block
*sb
, ino_t max_reserved
)
1171 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
1172 * error if st_ino won't fit in target struct field. Use 32bit counter
1173 * here to attempt to avoid that.
1175 static DEFINE_SPINLOCK(iunique_lock
);
1176 static unsigned int counter
;
1179 spin_lock(&iunique_lock
);
1181 if (counter
<= max_reserved
)
1182 counter
= max_reserved
+ 1;
1184 } while (!test_inode_iunique(sb
, res
));
1185 spin_unlock(&iunique_lock
);
1189 EXPORT_SYMBOL(iunique
);
1191 struct inode
*igrab(struct inode
*inode
)
1193 spin_lock(&inode
->i_lock
);
1194 if (!(inode
->i_state
& (I_FREEING
|I_WILL_FREE
))) {
1196 spin_unlock(&inode
->i_lock
);
1198 spin_unlock(&inode
->i_lock
);
1200 * Handle the case where s_op->clear_inode is not been
1201 * called yet, and somebody is calling igrab
1202 * while the inode is getting freed.
1208 EXPORT_SYMBOL(igrab
);
1211 * ilookup5_nowait - search for an inode in the inode cache
1212 * @sb: super block of file system to search
1213 * @hashval: hash value (usually inode number) to search for
1214 * @test: callback used for comparisons between inodes
1215 * @data: opaque data pointer to pass to @test
1217 * Search for the inode specified by @hashval and @data in the inode cache.
1218 * If the inode is in the cache, the inode is returned with an incremented
1221 * Note: I_NEW is not waited upon so you have to be very careful what you do
1222 * with the returned inode. You probably should be using ilookup5() instead.
1224 * Note2: @test is called with the inode_hash_lock held, so can't sleep.
1226 struct inode
*ilookup5_nowait(struct super_block
*sb
, unsigned long hashval
,
1227 int (*test
)(struct inode
*, void *), void *data
)
1229 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1230 struct inode
*inode
;
1232 spin_lock(&inode_hash_lock
);
1233 inode
= find_inode(sb
, head
, test
, data
);
1234 spin_unlock(&inode_hash_lock
);
1238 EXPORT_SYMBOL(ilookup5_nowait
);
1241 * ilookup5 - search for an inode in the inode cache
1242 * @sb: super block of file system to search
1243 * @hashval: hash value (usually inode number) to search for
1244 * @test: callback used for comparisons between inodes
1245 * @data: opaque data pointer to pass to @test
1247 * Search for the inode specified by @hashval and @data in the inode cache,
1248 * and if the inode is in the cache, return the inode with an incremented
1249 * reference count. Waits on I_NEW before returning the inode.
1250 * returned with an incremented reference count.
1252 * This is a generalized version of ilookup() for file systems where the
1253 * inode number is not sufficient for unique identification of an inode.
1255 * Note: @test is called with the inode_hash_lock held, so can't sleep.
1257 struct inode
*ilookup5(struct super_block
*sb
, unsigned long hashval
,
1258 int (*test
)(struct inode
*, void *), void *data
)
1260 struct inode
*inode
= ilookup5_nowait(sb
, hashval
, test
, data
);
1263 wait_on_inode(inode
);
1266 EXPORT_SYMBOL(ilookup5
);
1269 * ilookup - search for an inode in the inode cache
1270 * @sb: super block of file system to search
1271 * @ino: inode number to search for
1273 * Search for the inode @ino in the inode cache, and if the inode is in the
1274 * cache, the inode is returned with an incremented reference count.
1276 struct inode
*ilookup(struct super_block
*sb
, unsigned long ino
)
1278 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1279 struct inode
*inode
;
1281 spin_lock(&inode_hash_lock
);
1282 inode
= find_inode_fast(sb
, head
, ino
);
1283 spin_unlock(&inode_hash_lock
);
1286 wait_on_inode(inode
);
1289 EXPORT_SYMBOL(ilookup
);
1292 * find_inode_nowait - find an inode in the inode cache
1293 * @sb: super block of file system to search
1294 * @hashval: hash value (usually inode number) to search for
1295 * @match: callback used for comparisons between inodes
1296 * @data: opaque data pointer to pass to @match
1298 * Search for the inode specified by @hashval and @data in the inode
1299 * cache, where the helper function @match will return 0 if the inode
1300 * does not match, 1 if the inode does match, and -1 if the search
1301 * should be stopped. The @match function must be responsible for
1302 * taking the i_lock spin_lock and checking i_state for an inode being
1303 * freed or being initialized, and incrementing the reference count
1304 * before returning 1. It also must not sleep, since it is called with
1305 * the inode_hash_lock spinlock held.
1307 * This is a even more generalized version of ilookup5() when the
1308 * function must never block --- find_inode() can block in
1309 * __wait_on_freeing_inode() --- or when the caller can not increment
1310 * the reference count because the resulting iput() might cause an
1311 * inode eviction. The tradeoff is that the @match funtion must be
1312 * very carefully implemented.
1314 struct inode
*find_inode_nowait(struct super_block
*sb
,
1315 unsigned long hashval
,
1316 int (*match
)(struct inode
*, unsigned long,
1320 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1321 struct inode
*inode
, *ret_inode
= NULL
;
1324 spin_lock(&inode_hash_lock
);
1325 hlist_for_each_entry(inode
, head
, i_hash
) {
1326 if (inode
->i_sb
!= sb
)
1328 mval
= match(inode
, hashval
, data
);
1336 spin_unlock(&inode_hash_lock
);
1339 EXPORT_SYMBOL(find_inode_nowait
);
1341 int insert_inode_locked(struct inode
*inode
)
1343 struct super_block
*sb
= inode
->i_sb
;
1344 ino_t ino
= inode
->i_ino
;
1345 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1348 struct inode
*old
= NULL
;
1349 spin_lock(&inode_hash_lock
);
1350 hlist_for_each_entry(old
, head
, i_hash
) {
1351 if (old
->i_ino
!= ino
)
1353 if (old
->i_sb
!= sb
)
1355 spin_lock(&old
->i_lock
);
1356 if (old
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
1357 spin_unlock(&old
->i_lock
);
1363 spin_lock(&inode
->i_lock
);
1364 inode
->i_state
|= I_NEW
;
1365 hlist_add_head(&inode
->i_hash
, head
);
1366 spin_unlock(&inode
->i_lock
);
1367 spin_unlock(&inode_hash_lock
);
1371 spin_unlock(&old
->i_lock
);
1372 spin_unlock(&inode_hash_lock
);
1374 if (unlikely(!inode_unhashed(old
))) {
1381 EXPORT_SYMBOL(insert_inode_locked
);
1383 int insert_inode_locked4(struct inode
*inode
, unsigned long hashval
,
1384 int (*test
)(struct inode
*, void *), void *data
)
1386 struct super_block
*sb
= inode
->i_sb
;
1387 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1390 struct inode
*old
= NULL
;
1392 spin_lock(&inode_hash_lock
);
1393 hlist_for_each_entry(old
, head
, i_hash
) {
1394 if (old
->i_sb
!= sb
)
1396 if (!test(old
, data
))
1398 spin_lock(&old
->i_lock
);
1399 if (old
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
1400 spin_unlock(&old
->i_lock
);
1406 spin_lock(&inode
->i_lock
);
1407 inode
->i_state
|= I_NEW
;
1408 hlist_add_head(&inode
->i_hash
, head
);
1409 spin_unlock(&inode
->i_lock
);
1410 spin_unlock(&inode_hash_lock
);
1414 spin_unlock(&old
->i_lock
);
1415 spin_unlock(&inode_hash_lock
);
1417 if (unlikely(!inode_unhashed(old
))) {
1424 EXPORT_SYMBOL(insert_inode_locked4
);
1427 int generic_delete_inode(struct inode
*inode
)
1431 EXPORT_SYMBOL(generic_delete_inode
);
1434 * Called when we're dropping the last reference
1437 * Call the FS "drop_inode()" function, defaulting to
1438 * the legacy UNIX filesystem behaviour. If it tells
1439 * us to evict inode, do so. Otherwise, retain inode
1440 * in cache if fs is alive, sync and evict if fs is
1443 static void iput_final(struct inode
*inode
)
1445 struct super_block
*sb
= inode
->i_sb
;
1446 const struct super_operations
*op
= inode
->i_sb
->s_op
;
1449 WARN_ON(inode
->i_state
& I_NEW
);
1452 drop
= op
->drop_inode(inode
);
1454 drop
= generic_drop_inode(inode
);
1456 if (!drop
&& (sb
->s_flags
& MS_ACTIVE
)) {
1457 inode
->i_state
|= I_REFERENCED
;
1458 inode_add_lru(inode
);
1459 spin_unlock(&inode
->i_lock
);
1464 inode
->i_state
|= I_WILL_FREE
;
1465 spin_unlock(&inode
->i_lock
);
1466 write_inode_now(inode
, 1);
1467 spin_lock(&inode
->i_lock
);
1468 WARN_ON(inode
->i_state
& I_NEW
);
1469 inode
->i_state
&= ~I_WILL_FREE
;
1472 inode
->i_state
|= I_FREEING
;
1473 if (!list_empty(&inode
->i_lru
))
1474 inode_lru_list_del(inode
);
1475 spin_unlock(&inode
->i_lock
);
1481 * iput - put an inode
1482 * @inode: inode to put
1484 * Puts an inode, dropping its usage count. If the inode use count hits
1485 * zero, the inode is then freed and may also be destroyed.
1487 * Consequently, iput() can sleep.
1489 void iput(struct inode
*inode
)
1493 BUG_ON(inode
->i_state
& I_CLEAR
);
1495 if (atomic_dec_and_lock(&inode
->i_count
, &inode
->i_lock
)) {
1496 if (inode
->i_nlink
&& (inode
->i_state
& I_DIRTY_TIME
)) {
1497 atomic_inc(&inode
->i_count
);
1498 inode
->i_state
&= ~I_DIRTY_TIME
;
1499 spin_unlock(&inode
->i_lock
);
1500 trace_writeback_lazytime_iput(inode
);
1501 mark_inode_dirty_sync(inode
);
1507 EXPORT_SYMBOL(iput
);
1510 * bmap - find a block number in a file
1511 * @inode: inode of file
1512 * @block: block to find
1514 * Returns the block number on the device holding the inode that
1515 * is the disk block number for the block of the file requested.
1516 * That is, asked for block 4 of inode 1 the function will return the
1517 * disk block relative to the disk start that holds that block of the
1520 sector_t
bmap(struct inode
*inode
, sector_t block
)
1523 if (inode
->i_mapping
->a_ops
->bmap
)
1524 res
= inode
->i_mapping
->a_ops
->bmap(inode
->i_mapping
, block
);
1527 EXPORT_SYMBOL(bmap
);
1530 * With relative atime, only update atime if the previous atime is
1531 * earlier than either the ctime or mtime or if at least a day has
1532 * passed since the last atime update.
1534 static int relatime_need_update(struct vfsmount
*mnt
, struct inode
*inode
,
1535 struct timespec now
)
1538 if (!(mnt
->mnt_flags
& MNT_RELATIME
))
1541 * Is mtime younger than atime? If yes, update atime:
1543 if (timespec_compare(&inode
->i_mtime
, &inode
->i_atime
) >= 0)
1546 * Is ctime younger than atime? If yes, update atime:
1548 if (timespec_compare(&inode
->i_ctime
, &inode
->i_atime
) >= 0)
1552 * Is the previous atime value older than a day? If yes,
1555 if ((long)(now
.tv_sec
- inode
->i_atime
.tv_sec
) >= 24*60*60)
1558 * Good, we can skip the atime update:
1563 int generic_update_time(struct inode
*inode
, struct timespec
*time
, int flags
)
1565 int iflags
= I_DIRTY_TIME
;
1567 if (flags
& S_ATIME
)
1568 inode
->i_atime
= *time
;
1569 if (flags
& S_VERSION
)
1570 inode_inc_iversion(inode
);
1571 if (flags
& S_CTIME
)
1572 inode
->i_ctime
= *time
;
1573 if (flags
& S_MTIME
)
1574 inode
->i_mtime
= *time
;
1576 if (!(inode
->i_sb
->s_flags
& MS_LAZYTIME
) || (flags
& S_VERSION
))
1577 iflags
|= I_DIRTY_SYNC
;
1578 __mark_inode_dirty(inode
, iflags
);
1581 EXPORT_SYMBOL(generic_update_time
);
1584 * This does the actual work of updating an inodes time or version. Must have
1585 * had called mnt_want_write() before calling this.
1587 static int update_time(struct inode
*inode
, struct timespec
*time
, int flags
)
1589 int (*update_time
)(struct inode
*, struct timespec
*, int);
1591 update_time
= inode
->i_op
->update_time
? inode
->i_op
->update_time
:
1592 generic_update_time
;
1594 return update_time(inode
, time
, flags
);
1598 * touch_atime - update the access time
1599 * @path: the &struct path to update
1600 * @inode: inode to update
1602 * Update the accessed time on an inode and mark it for writeback.
1603 * This function automatically handles read only file systems and media,
1604 * as well as the "noatime" flag and inode specific "noatime" markers.
1606 bool atime_needs_update(const struct path
*path
, struct inode
*inode
)
1608 struct vfsmount
*mnt
= path
->mnt
;
1609 struct timespec now
;
1611 if (inode
->i_flags
& S_NOATIME
)
1613 if (IS_NOATIME(inode
))
1615 if ((inode
->i_sb
->s_flags
& MS_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1618 if (mnt
->mnt_flags
& MNT_NOATIME
)
1620 if ((mnt
->mnt_flags
& MNT_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1623 now
= current_fs_time(inode
->i_sb
);
1625 if (!relatime_need_update(mnt
, inode
, now
))
1628 if (timespec_equal(&inode
->i_atime
, &now
))
1634 void touch_atime(const struct path
*path
)
1636 struct vfsmount
*mnt
= path
->mnt
;
1637 struct inode
*inode
= d_inode(path
->dentry
);
1638 struct timespec now
;
1640 if (!atime_needs_update(path
, inode
))
1643 if (!sb_start_write_trylock(inode
->i_sb
))
1646 if (__mnt_want_write(mnt
) != 0)
1649 * File systems can error out when updating inodes if they need to
1650 * allocate new space to modify an inode (such is the case for
1651 * Btrfs), but since we touch atime while walking down the path we
1652 * really don't care if we failed to update the atime of the file,
1653 * so just ignore the return value.
1654 * We may also fail on filesystems that have the ability to make parts
1655 * of the fs read only, e.g. subvolumes in Btrfs.
1657 now
= current_fs_time(inode
->i_sb
);
1658 update_time(inode
, &now
, S_ATIME
);
1659 __mnt_drop_write(mnt
);
1661 sb_end_write(inode
->i_sb
);
1663 EXPORT_SYMBOL(touch_atime
);
1666 * The logic we want is
1668 * if suid or (sgid and xgrp)
1671 int should_remove_suid(struct dentry
*dentry
)
1673 umode_t mode
= d_inode(dentry
)->i_mode
;
1676 /* suid always must be killed */
1677 if (unlikely(mode
& S_ISUID
))
1678 kill
= ATTR_KILL_SUID
;
1681 * sgid without any exec bits is just a mandatory locking mark; leave
1682 * it alone. If some exec bits are set, it's a real sgid; kill it.
1684 if (unlikely((mode
& S_ISGID
) && (mode
& S_IXGRP
)))
1685 kill
|= ATTR_KILL_SGID
;
1687 if (unlikely(kill
&& !capable(CAP_FSETID
) && S_ISREG(mode
)))
1692 EXPORT_SYMBOL(should_remove_suid
);
1695 * Return mask of changes for notify_change() that need to be done as a
1696 * response to write or truncate. Return 0 if nothing has to be changed.
1697 * Negative value on error (change should be denied).
1699 int dentry_needs_remove_privs(struct dentry
*dentry
)
1701 struct inode
*inode
= d_inode(dentry
);
1705 if (IS_NOSEC(inode
))
1708 mask
= should_remove_suid(dentry
);
1709 ret
= security_inode_need_killpriv(dentry
);
1713 mask
|= ATTR_KILL_PRIV
;
1716 EXPORT_SYMBOL(dentry_needs_remove_privs
);
1718 static int __remove_privs(struct dentry
*dentry
, int kill
)
1720 struct iattr newattrs
;
1722 newattrs
.ia_valid
= ATTR_FORCE
| kill
;
1724 * Note we call this on write, so notify_change will not
1725 * encounter any conflicting delegations:
1727 return notify_change(dentry
, &newattrs
, NULL
);
1731 * Remove special file priviledges (suid, capabilities) when file is written
1734 int file_remove_privs(struct file
*file
)
1736 struct dentry
*dentry
= file_dentry(file
);
1737 struct inode
*inode
= file_inode(file
);
1741 /* Fast path for nothing security related */
1742 if (IS_NOSEC(inode
))
1745 kill
= dentry_needs_remove_privs(dentry
);
1749 error
= __remove_privs(dentry
, kill
);
1751 inode_has_no_xattr(inode
);
1755 EXPORT_SYMBOL(file_remove_privs
);
1758 * file_update_time - update mtime and ctime time
1759 * @file: file accessed
1761 * Update the mtime and ctime members of an inode and mark the inode
1762 * for writeback. Note that this function is meant exclusively for
1763 * usage in the file write path of filesystems, and filesystems may
1764 * choose to explicitly ignore update via this function with the
1765 * S_NOCMTIME inode flag, e.g. for network filesystem where these
1766 * timestamps are handled by the server. This can return an error for
1767 * file systems who need to allocate space in order to update an inode.
1770 int file_update_time(struct file
*file
)
1772 struct inode
*inode
= file_inode(file
);
1773 struct timespec now
;
1777 /* First try to exhaust all avenues to not sync */
1778 if (IS_NOCMTIME(inode
))
1781 now
= current_fs_time(inode
->i_sb
);
1782 if (!timespec_equal(&inode
->i_mtime
, &now
))
1785 if (!timespec_equal(&inode
->i_ctime
, &now
))
1788 if (IS_I_VERSION(inode
))
1789 sync_it
|= S_VERSION
;
1794 /* Finally allowed to write? Takes lock. */
1795 if (__mnt_want_write_file(file
))
1798 ret
= update_time(inode
, &now
, sync_it
);
1799 __mnt_drop_write_file(file
);
1803 EXPORT_SYMBOL(file_update_time
);
1805 int inode_needs_sync(struct inode
*inode
)
1809 if (S_ISDIR(inode
->i_mode
) && IS_DIRSYNC(inode
))
1813 EXPORT_SYMBOL(inode_needs_sync
);
1816 * If we try to find an inode in the inode hash while it is being
1817 * deleted, we have to wait until the filesystem completes its
1818 * deletion before reporting that it isn't found. This function waits
1819 * until the deletion _might_ have completed. Callers are responsible
1820 * to recheck inode state.
1822 * It doesn't matter if I_NEW is not set initially, a call to
1823 * wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list
1826 static void __wait_on_freeing_inode(struct inode
*inode
)
1828 wait_queue_head_t
*wq
;
1829 DEFINE_WAIT_BIT(wait
, &inode
->i_state
, __I_NEW
);
1830 wq
= bit_waitqueue(&inode
->i_state
, __I_NEW
);
1831 prepare_to_wait(wq
, &wait
.wait
, TASK_UNINTERRUPTIBLE
);
1832 spin_unlock(&inode
->i_lock
);
1833 spin_unlock(&inode_hash_lock
);
1835 finish_wait(wq
, &wait
.wait
);
1836 spin_lock(&inode_hash_lock
);
1839 static __initdata
unsigned long ihash_entries
;
1840 static int __init
set_ihash_entries(char *str
)
1844 ihash_entries
= simple_strtoul(str
, &str
, 0);
1847 __setup("ihash_entries=", set_ihash_entries
);
1850 * Initialize the waitqueues and inode hash table.
1852 void __init
inode_init_early(void)
1856 /* If hashes are distributed across NUMA nodes, defer
1857 * hash allocation until vmalloc space is available.
1863 alloc_large_system_hash("Inode-cache",
1864 sizeof(struct hlist_head
),
1873 for (loop
= 0; loop
< (1U << i_hash_shift
); loop
++)
1874 INIT_HLIST_HEAD(&inode_hashtable
[loop
]);
1877 void __init
inode_init(void)
1881 /* inode slab cache */
1882 inode_cachep
= kmem_cache_create("inode_cache",
1883 sizeof(struct inode
),
1885 (SLAB_RECLAIM_ACCOUNT
|SLAB_PANIC
|
1889 /* Hash may have been set up in inode_init_early */
1894 alloc_large_system_hash("Inode-cache",
1895 sizeof(struct hlist_head
),
1904 for (loop
= 0; loop
< (1U << i_hash_shift
); loop
++)
1905 INIT_HLIST_HEAD(&inode_hashtable
[loop
]);
1908 void init_special_inode(struct inode
*inode
, umode_t mode
, dev_t rdev
)
1910 inode
->i_mode
= mode
;
1911 if (S_ISCHR(mode
)) {
1912 inode
->i_fop
= &def_chr_fops
;
1913 inode
->i_rdev
= rdev
;
1914 } else if (S_ISBLK(mode
)) {
1915 inode
->i_fop
= &def_blk_fops
;
1916 inode
->i_rdev
= rdev
;
1917 } else if (S_ISFIFO(mode
))
1918 inode
->i_fop
= &pipefifo_fops
;
1919 else if (S_ISSOCK(mode
))
1920 ; /* leave it no_open_fops */
1922 printk(KERN_DEBUG
"init_special_inode: bogus i_mode (%o) for"
1923 " inode %s:%lu\n", mode
, inode
->i_sb
->s_id
,
1926 EXPORT_SYMBOL(init_special_inode
);
1929 * inode_init_owner - Init uid,gid,mode for new inode according to posix standards
1931 * @dir: Directory inode
1932 * @mode: mode of the new inode
1934 void inode_init_owner(struct inode
*inode
, const struct inode
*dir
,
1937 inode
->i_uid
= current_fsuid();
1938 if (dir
&& dir
->i_mode
& S_ISGID
) {
1939 inode
->i_gid
= dir
->i_gid
;
1941 /* Directories are special, and always inherit S_ISGID */
1944 else if ((mode
& (S_ISGID
| S_IXGRP
)) == (S_ISGID
| S_IXGRP
) &&
1945 !in_group_p(inode
->i_gid
) &&
1946 !capable_wrt_inode_uidgid(dir
, CAP_FSETID
))
1949 inode
->i_gid
= current_fsgid();
1950 inode
->i_mode
= mode
;
1952 EXPORT_SYMBOL(inode_init_owner
);
1955 * inode_owner_or_capable - check current task permissions to inode
1956 * @inode: inode being checked
1958 * Return true if current either has CAP_FOWNER in a namespace with the
1959 * inode owner uid mapped, or owns the file.
1961 bool inode_owner_or_capable(const struct inode
*inode
)
1963 struct user_namespace
*ns
;
1965 if (uid_eq(current_fsuid(), inode
->i_uid
))
1968 ns
= current_user_ns();
1969 if (ns_capable(ns
, CAP_FOWNER
) && kuid_has_mapping(ns
, inode
->i_uid
))
1973 EXPORT_SYMBOL(inode_owner_or_capable
);
1976 * Direct i/o helper functions
1978 static void __inode_dio_wait(struct inode
*inode
)
1980 wait_queue_head_t
*wq
= bit_waitqueue(&inode
->i_state
, __I_DIO_WAKEUP
);
1981 DEFINE_WAIT_BIT(q
, &inode
->i_state
, __I_DIO_WAKEUP
);
1984 prepare_to_wait(wq
, &q
.wait
, TASK_UNINTERRUPTIBLE
);
1985 if (atomic_read(&inode
->i_dio_count
))
1987 } while (atomic_read(&inode
->i_dio_count
));
1988 finish_wait(wq
, &q
.wait
);
1992 * inode_dio_wait - wait for outstanding DIO requests to finish
1993 * @inode: inode to wait for
1995 * Waits for all pending direct I/O requests to finish so that we can
1996 * proceed with a truncate or equivalent operation.
1998 * Must be called under a lock that serializes taking new references
1999 * to i_dio_count, usually by inode->i_mutex.
2001 void inode_dio_wait(struct inode
*inode
)
2003 if (atomic_read(&inode
->i_dio_count
))
2004 __inode_dio_wait(inode
);
2006 EXPORT_SYMBOL(inode_dio_wait
);
2009 * inode_set_flags - atomically set some inode flags
2011 * Note: the caller should be holding i_mutex, or else be sure that
2012 * they have exclusive access to the inode structure (i.e., while the
2013 * inode is being instantiated). The reason for the cmpxchg() loop
2014 * --- which wouldn't be necessary if all code paths which modify
2015 * i_flags actually followed this rule, is that there is at least one
2016 * code path which doesn't today so we use cmpxchg() out of an abundance
2019 * In the long run, i_mutex is overkill, and we should probably look
2020 * at using the i_lock spinlock to protect i_flags, and then make sure
2021 * it is so documented in include/linux/fs.h and that all code follows
2022 * the locking convention!!
2024 void inode_set_flags(struct inode
*inode
, unsigned int flags
,
2027 unsigned int old_flags
, new_flags
;
2029 WARN_ON_ONCE(flags
& ~mask
);
2031 old_flags
= ACCESS_ONCE(inode
->i_flags
);
2032 new_flags
= (old_flags
& ~mask
) | flags
;
2033 } while (unlikely(cmpxchg(&inode
->i_flags
, old_flags
,
2034 new_flags
) != old_flags
));
2036 EXPORT_SYMBOL(inode_set_flags
);
2038 void inode_nohighmem(struct inode
*inode
)
2040 mapping_set_gfp_mask(inode
->i_mapping
, GFP_USER
);
2042 EXPORT_SYMBOL(inode_nohighmem
);