1 // SPDX-License-Identifier: GPL-2.0-only
3 * (C) 1997 Linus Torvalds
4 * (C) 1999 Andrea Arcangeli <andrea@suse.de> (dynamic inode allocation)
6 #include <linux/export.h>
9 #include <linux/backing-dev.h>
10 #include <linux/hash.h>
11 #include <linux/swap.h>
12 #include <linux/security.h>
13 #include <linux/cdev.h>
14 #include <linux/memblock.h>
15 #include <linux/fsnotify.h>
16 #include <linux/mount.h>
17 #include <linux/posix_acl.h>
18 #include <linux/prefetch.h>
19 #include <linux/buffer_head.h> /* for inode_has_buffers */
20 #include <linux/ratelimit.h>
21 #include <linux/list_lru.h>
22 #include <linux/iversion.h>
23 #include <trace/events/writeback.h>
27 * Inode locking rules:
29 * inode->i_lock protects:
30 * inode->i_state, inode->i_hash, __iget(), inode->i_io_list
31 * Inode LRU list locks protect:
32 * inode->i_sb->s_inode_lru, inode->i_lru
33 * inode->i_sb->s_inode_list_lock protects:
34 * inode->i_sb->s_inodes, inode->i_sb_list
35 * bdi->wb.list_lock protects:
36 * bdi->wb.b_{dirty,io,more_io,dirty_time}, inode->i_io_list
37 * inode_hash_lock protects:
38 * inode_hashtable, inode->i_hash
42 * inode->i_sb->s_inode_list_lock
44 * Inode LRU list locks
50 * inode->i_sb->s_inode_list_lock
57 static unsigned int i_hash_mask __read_mostly
;
58 static unsigned int i_hash_shift __read_mostly
;
59 static struct hlist_head
*inode_hashtable __read_mostly
;
60 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(inode_hash_lock
);
63 * Empty aops. Can be used for the cases where the user does not
64 * define any of the address_space operations.
66 const struct address_space_operations empty_aops
= {
68 EXPORT_SYMBOL(empty_aops
);
71 * Statistics gathering..
73 struct inodes_stat_t inodes_stat
;
75 static DEFINE_PER_CPU(unsigned long, nr_inodes
);
76 static DEFINE_PER_CPU(unsigned long, nr_unused
);
78 static struct kmem_cache
*inode_cachep __read_mostly
;
80 static long get_nr_inodes(void)
84 for_each_possible_cpu(i
)
85 sum
+= per_cpu(nr_inodes
, i
);
86 return sum
< 0 ? 0 : sum
;
89 static inline long get_nr_inodes_unused(void)
93 for_each_possible_cpu(i
)
94 sum
+= per_cpu(nr_unused
, i
);
95 return sum
< 0 ? 0 : sum
;
98 long get_nr_dirty_inodes(void)
100 /* not actually dirty inodes, but a wild approximation */
101 long nr_dirty
= get_nr_inodes() - get_nr_inodes_unused();
102 return nr_dirty
> 0 ? nr_dirty
: 0;
106 * Handle nr_inode sysctl
109 int proc_nr_inodes(struct ctl_table
*table
, int write
,
110 void *buffer
, size_t *lenp
, loff_t
*ppos
)
112 inodes_stat
.nr_inodes
= get_nr_inodes();
113 inodes_stat
.nr_unused
= get_nr_inodes_unused();
114 return proc_doulongvec_minmax(table
, write
, buffer
, lenp
, ppos
);
118 static int no_open(struct inode
*inode
, struct file
*file
)
124 * inode_init_always - perform inode structure initialisation
125 * @sb: superblock inode belongs to
126 * @inode: inode to initialise
128 * These are initializations that need to be done on every inode
129 * allocation as the fields are not initialised by slab allocation.
131 int inode_init_always(struct super_block
*sb
, struct inode
*inode
)
133 static const struct inode_operations empty_iops
;
134 static const struct file_operations no_open_fops
= {.open
= no_open
};
135 struct address_space
*const mapping
= &inode
->i_data
;
138 inode
->i_blkbits
= sb
->s_blocksize_bits
;
140 atomic64_set(&inode
->i_sequence
, 0);
141 atomic_set(&inode
->i_count
, 1);
142 inode
->i_op
= &empty_iops
;
143 inode
->i_fop
= &no_open_fops
;
145 inode
->__i_nlink
= 1;
146 inode
->i_opflags
= 0;
148 inode
->i_opflags
|= IOP_XATTR
;
149 i_uid_write(inode
, 0);
150 i_gid_write(inode
, 0);
151 atomic_set(&inode
->i_writecount
, 0);
153 inode
->i_write_hint
= WRITE_LIFE_NOT_SET
;
156 inode
->i_generation
= 0;
157 inode
->i_pipe
= NULL
;
158 inode
->i_cdev
= NULL
;
159 inode
->i_link
= NULL
;
160 inode
->i_dir_seq
= 0;
162 inode
->dirtied_when
= 0;
164 #ifdef CONFIG_CGROUP_WRITEBACK
165 inode
->i_wb_frn_winner
= 0;
166 inode
->i_wb_frn_avg_time
= 0;
167 inode
->i_wb_frn_history
= 0;
170 if (security_inode_alloc(inode
))
172 spin_lock_init(&inode
->i_lock
);
173 lockdep_set_class(&inode
->i_lock
, &sb
->s_type
->i_lock_key
);
175 init_rwsem(&inode
->i_rwsem
);
176 lockdep_set_class(&inode
->i_rwsem
, &sb
->s_type
->i_mutex_key
);
178 atomic_set(&inode
->i_dio_count
, 0);
180 mapping
->a_ops
= &empty_aops
;
181 mapping
->host
= inode
;
183 if (sb
->s_type
->fs_flags
& FS_THP_SUPPORT
)
184 __set_bit(AS_THP_SUPPORT
, &mapping
->flags
);
186 atomic_set(&mapping
->i_mmap_writable
, 0);
187 #ifdef CONFIG_READ_ONLY_THP_FOR_FS
188 atomic_set(&mapping
->nr_thps
, 0);
190 mapping_set_gfp_mask(mapping
, GFP_HIGHUSER_MOVABLE
);
191 mapping
->private_data
= NULL
;
192 mapping
->writeback_index
= 0;
193 init_rwsem(&mapping
->invalidate_lock
);
194 lockdep_set_class_and_name(&mapping
->invalidate_lock
,
195 &sb
->s_type
->invalidate_lock_key
,
196 "mapping.invalidate_lock");
197 inode
->i_private
= NULL
;
198 inode
->i_mapping
= mapping
;
199 INIT_HLIST_HEAD(&inode
->i_dentry
); /* buggered by rcu freeing */
200 #ifdef CONFIG_FS_POSIX_ACL
201 inode
->i_acl
= inode
->i_default_acl
= ACL_NOT_CACHED
;
204 #ifdef CONFIG_FSNOTIFY
205 inode
->i_fsnotify_mask
= 0;
207 inode
->i_flctx
= NULL
;
208 this_cpu_inc(nr_inodes
);
214 EXPORT_SYMBOL(inode_init_always
);
216 void free_inode_nonrcu(struct inode
*inode
)
218 kmem_cache_free(inode_cachep
, inode
);
220 EXPORT_SYMBOL(free_inode_nonrcu
);
222 static void i_callback(struct rcu_head
*head
)
224 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
225 if (inode
->free_inode
)
226 inode
->free_inode(inode
);
228 free_inode_nonrcu(inode
);
231 static struct inode
*alloc_inode(struct super_block
*sb
)
233 const struct super_operations
*ops
= sb
->s_op
;
236 if (ops
->alloc_inode
)
237 inode
= ops
->alloc_inode(sb
);
239 inode
= kmem_cache_alloc(inode_cachep
, GFP_KERNEL
);
244 if (unlikely(inode_init_always(sb
, inode
))) {
245 if (ops
->destroy_inode
) {
246 ops
->destroy_inode(inode
);
247 if (!ops
->free_inode
)
250 inode
->free_inode
= ops
->free_inode
;
251 i_callback(&inode
->i_rcu
);
258 void __destroy_inode(struct inode
*inode
)
260 BUG_ON(inode_has_buffers(inode
));
261 inode_detach_wb(inode
);
262 security_inode_free(inode
);
263 fsnotify_inode_delete(inode
);
264 locks_free_lock_context(inode
);
265 if (!inode
->i_nlink
) {
266 WARN_ON(atomic_long_read(&inode
->i_sb
->s_remove_count
) == 0);
267 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
270 #ifdef CONFIG_FS_POSIX_ACL
271 if (inode
->i_acl
&& !is_uncached_acl(inode
->i_acl
))
272 posix_acl_release(inode
->i_acl
);
273 if (inode
->i_default_acl
&& !is_uncached_acl(inode
->i_default_acl
))
274 posix_acl_release(inode
->i_default_acl
);
276 this_cpu_dec(nr_inodes
);
278 EXPORT_SYMBOL(__destroy_inode
);
280 static void destroy_inode(struct inode
*inode
)
282 const struct super_operations
*ops
= inode
->i_sb
->s_op
;
284 BUG_ON(!list_empty(&inode
->i_lru
));
285 __destroy_inode(inode
);
286 if (ops
->destroy_inode
) {
287 ops
->destroy_inode(inode
);
288 if (!ops
->free_inode
)
291 inode
->free_inode
= ops
->free_inode
;
292 call_rcu(&inode
->i_rcu
, i_callback
);
296 * drop_nlink - directly drop an inode's link count
299 * This is a low-level filesystem helper to replace any
300 * direct filesystem manipulation of i_nlink. In cases
301 * where we are attempting to track writes to the
302 * filesystem, a decrement to zero means an imminent
303 * write when the file is truncated and actually unlinked
306 void drop_nlink(struct inode
*inode
)
308 WARN_ON(inode
->i_nlink
== 0);
311 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
313 EXPORT_SYMBOL(drop_nlink
);
316 * clear_nlink - directly zero an inode's link count
319 * This is a low-level filesystem helper to replace any
320 * direct filesystem manipulation of i_nlink. See
321 * drop_nlink() for why we care about i_nlink hitting zero.
323 void clear_nlink(struct inode
*inode
)
325 if (inode
->i_nlink
) {
326 inode
->__i_nlink
= 0;
327 atomic_long_inc(&inode
->i_sb
->s_remove_count
);
330 EXPORT_SYMBOL(clear_nlink
);
333 * set_nlink - directly set an inode's link count
335 * @nlink: new nlink (should be non-zero)
337 * This is a low-level filesystem helper to replace any
338 * direct filesystem manipulation of i_nlink.
340 void set_nlink(struct inode
*inode
, unsigned int nlink
)
345 /* Yes, some filesystems do change nlink from zero to one */
346 if (inode
->i_nlink
== 0)
347 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
349 inode
->__i_nlink
= nlink
;
352 EXPORT_SYMBOL(set_nlink
);
355 * inc_nlink - directly increment an inode's link count
358 * This is a low-level filesystem helper to replace any
359 * direct filesystem manipulation of i_nlink. Currently,
360 * it is only here for parity with dec_nlink().
362 void inc_nlink(struct inode
*inode
)
364 if (unlikely(inode
->i_nlink
== 0)) {
365 WARN_ON(!(inode
->i_state
& I_LINKABLE
));
366 atomic_long_dec(&inode
->i_sb
->s_remove_count
);
371 EXPORT_SYMBOL(inc_nlink
);
373 static void __address_space_init_once(struct address_space
*mapping
)
375 xa_init_flags(&mapping
->i_pages
, XA_FLAGS_LOCK_IRQ
| XA_FLAGS_ACCOUNT
);
376 init_rwsem(&mapping
->i_mmap_rwsem
);
377 INIT_LIST_HEAD(&mapping
->private_list
);
378 spin_lock_init(&mapping
->private_lock
);
379 mapping
->i_mmap
= RB_ROOT_CACHED
;
382 void address_space_init_once(struct address_space
*mapping
)
384 memset(mapping
, 0, sizeof(*mapping
));
385 __address_space_init_once(mapping
);
387 EXPORT_SYMBOL(address_space_init_once
);
390 * These are initializations that only need to be done
391 * once, because the fields are idempotent across use
392 * of the inode, so let the slab aware of that.
394 void inode_init_once(struct inode
*inode
)
396 memset(inode
, 0, sizeof(*inode
));
397 INIT_HLIST_NODE(&inode
->i_hash
);
398 INIT_LIST_HEAD(&inode
->i_devices
);
399 INIT_LIST_HEAD(&inode
->i_io_list
);
400 INIT_LIST_HEAD(&inode
->i_wb_list
);
401 INIT_LIST_HEAD(&inode
->i_lru
);
402 __address_space_init_once(&inode
->i_data
);
403 i_size_ordered_init(inode
);
405 EXPORT_SYMBOL(inode_init_once
);
407 static void init_once(void *foo
)
409 struct inode
*inode
= (struct inode
*) foo
;
411 inode_init_once(inode
);
415 * inode->i_lock must be held
417 void __iget(struct inode
*inode
)
419 atomic_inc(&inode
->i_count
);
423 * get additional reference to inode; caller must already hold one.
425 void ihold(struct inode
*inode
)
427 WARN_ON(atomic_inc_return(&inode
->i_count
) < 2);
429 EXPORT_SYMBOL(ihold
);
431 static void inode_lru_list_add(struct inode
*inode
)
433 if (list_lru_add(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
434 this_cpu_inc(nr_unused
);
436 inode
->i_state
|= I_REFERENCED
;
440 * Add inode to LRU if needed (inode is unused and clean).
442 * Needs inode->i_lock held.
444 void inode_add_lru(struct inode
*inode
)
446 if (!(inode
->i_state
& (I_DIRTY_ALL
| I_SYNC
|
447 I_FREEING
| I_WILL_FREE
)) &&
448 !atomic_read(&inode
->i_count
) && inode
->i_sb
->s_flags
& SB_ACTIVE
)
449 inode_lru_list_add(inode
);
453 static void inode_lru_list_del(struct inode
*inode
)
456 if (list_lru_del(&inode
->i_sb
->s_inode_lru
, &inode
->i_lru
))
457 this_cpu_dec(nr_unused
);
461 * inode_sb_list_add - add inode to the superblock list of inodes
462 * @inode: inode to add
464 void inode_sb_list_add(struct inode
*inode
)
466 spin_lock(&inode
->i_sb
->s_inode_list_lock
);
467 list_add(&inode
->i_sb_list
, &inode
->i_sb
->s_inodes
);
468 spin_unlock(&inode
->i_sb
->s_inode_list_lock
);
470 EXPORT_SYMBOL_GPL(inode_sb_list_add
);
472 static inline void inode_sb_list_del(struct inode
*inode
)
474 if (!list_empty(&inode
->i_sb_list
)) {
475 spin_lock(&inode
->i_sb
->s_inode_list_lock
);
476 list_del_init(&inode
->i_sb_list
);
477 spin_unlock(&inode
->i_sb
->s_inode_list_lock
);
481 static unsigned long hash(struct super_block
*sb
, unsigned long hashval
)
485 tmp
= (hashval
* (unsigned long)sb
) ^ (GOLDEN_RATIO_PRIME
+ hashval
) /
487 tmp
= tmp
^ ((tmp
^ GOLDEN_RATIO_PRIME
) >> i_hash_shift
);
488 return tmp
& i_hash_mask
;
492 * __insert_inode_hash - hash an inode
493 * @inode: unhashed inode
494 * @hashval: unsigned long value used to locate this object in the
497 * Add an inode to the inode hash for this superblock.
499 void __insert_inode_hash(struct inode
*inode
, unsigned long hashval
)
501 struct hlist_head
*b
= inode_hashtable
+ hash(inode
->i_sb
, hashval
);
503 spin_lock(&inode_hash_lock
);
504 spin_lock(&inode
->i_lock
);
505 hlist_add_head_rcu(&inode
->i_hash
, b
);
506 spin_unlock(&inode
->i_lock
);
507 spin_unlock(&inode_hash_lock
);
509 EXPORT_SYMBOL(__insert_inode_hash
);
512 * __remove_inode_hash - remove an inode from the hash
513 * @inode: inode to unhash
515 * Remove an inode from the superblock.
517 void __remove_inode_hash(struct inode
*inode
)
519 spin_lock(&inode_hash_lock
);
520 spin_lock(&inode
->i_lock
);
521 hlist_del_init_rcu(&inode
->i_hash
);
522 spin_unlock(&inode
->i_lock
);
523 spin_unlock(&inode_hash_lock
);
525 EXPORT_SYMBOL(__remove_inode_hash
);
527 void clear_inode(struct inode
*inode
)
530 * We have to cycle the i_pages lock here because reclaim can be in the
531 * process of removing the last page (in __delete_from_page_cache())
532 * and we must not free the mapping under it.
534 xa_lock_irq(&inode
->i_data
.i_pages
);
535 BUG_ON(inode
->i_data
.nrpages
);
537 * Almost always, mapping_empty(&inode->i_data) here; but there are
538 * two known and long-standing ways in which nodes may get left behind
539 * (when deep radix-tree node allocation failed partway; or when THP
540 * collapse_file() failed). Until those two known cases are cleaned up,
541 * or a cleanup function is called here, do not BUG_ON(!mapping_empty),
542 * nor even WARN_ON(!mapping_empty).
544 xa_unlock_irq(&inode
->i_data
.i_pages
);
545 BUG_ON(!list_empty(&inode
->i_data
.private_list
));
546 BUG_ON(!(inode
->i_state
& I_FREEING
));
547 BUG_ON(inode
->i_state
& I_CLEAR
);
548 BUG_ON(!list_empty(&inode
->i_wb_list
));
549 /* don't need i_lock here, no concurrent mods to i_state */
550 inode
->i_state
= I_FREEING
| I_CLEAR
;
552 EXPORT_SYMBOL(clear_inode
);
555 * Free the inode passed in, removing it from the lists it is still connected
556 * to. We remove any pages still attached to the inode and wait for any IO that
557 * is still in progress before finally destroying the inode.
559 * An inode must already be marked I_FREEING so that we avoid the inode being
560 * moved back onto lists if we race with other code that manipulates the lists
561 * (e.g. writeback_single_inode). The caller is responsible for setting this.
563 * An inode must already be removed from the LRU list before being evicted from
564 * the cache. This should occur atomically with setting the I_FREEING state
565 * flag, so no inodes here should ever be on the LRU when being evicted.
567 static void evict(struct inode
*inode
)
569 const struct super_operations
*op
= inode
->i_sb
->s_op
;
571 BUG_ON(!(inode
->i_state
& I_FREEING
));
572 BUG_ON(!list_empty(&inode
->i_lru
));
574 if (!list_empty(&inode
->i_io_list
))
575 inode_io_list_del(inode
);
577 inode_sb_list_del(inode
);
580 * Wait for flusher thread to be done with the inode so that filesystem
581 * does not start destroying it while writeback is still running. Since
582 * the inode has I_FREEING set, flusher thread won't start new work on
583 * the inode. We just have to wait for running writeback to finish.
585 inode_wait_for_writeback(inode
);
587 if (op
->evict_inode
) {
588 op
->evict_inode(inode
);
590 truncate_inode_pages_final(&inode
->i_data
);
593 if (S_ISCHR(inode
->i_mode
) && inode
->i_cdev
)
596 remove_inode_hash(inode
);
598 spin_lock(&inode
->i_lock
);
599 wake_up_bit(&inode
->i_state
, __I_NEW
);
600 BUG_ON(inode
->i_state
!= (I_FREEING
| I_CLEAR
));
601 spin_unlock(&inode
->i_lock
);
603 destroy_inode(inode
);
607 * dispose_list - dispose of the contents of a local list
608 * @head: the head of the list to free
610 * Dispose-list gets a local list with local inodes in it, so it doesn't
611 * need to worry about list corruption and SMP locks.
613 static void dispose_list(struct list_head
*head
)
615 while (!list_empty(head
)) {
618 inode
= list_first_entry(head
, struct inode
, i_lru
);
619 list_del_init(&inode
->i_lru
);
627 * evict_inodes - evict all evictable inodes for a superblock
628 * @sb: superblock to operate on
630 * Make sure that no inodes with zero refcount are retained. This is
631 * called by superblock shutdown after having SB_ACTIVE flag removed,
632 * so any inode reaching zero refcount during or after that call will
633 * be immediately evicted.
635 void evict_inodes(struct super_block
*sb
)
637 struct inode
*inode
, *next
;
641 spin_lock(&sb
->s_inode_list_lock
);
642 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
643 if (atomic_read(&inode
->i_count
))
646 spin_lock(&inode
->i_lock
);
647 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
648 spin_unlock(&inode
->i_lock
);
652 inode
->i_state
|= I_FREEING
;
653 inode_lru_list_del(inode
);
654 spin_unlock(&inode
->i_lock
);
655 list_add(&inode
->i_lru
, &dispose
);
658 * We can have a ton of inodes to evict at unmount time given
659 * enough memory, check to see if we need to go to sleep for a
660 * bit so we don't livelock.
662 if (need_resched()) {
663 spin_unlock(&sb
->s_inode_list_lock
);
665 dispose_list(&dispose
);
669 spin_unlock(&sb
->s_inode_list_lock
);
671 dispose_list(&dispose
);
673 EXPORT_SYMBOL_GPL(evict_inodes
);
676 * invalidate_inodes - attempt to free all inodes on a superblock
677 * @sb: superblock to operate on
678 * @kill_dirty: flag to guide handling of dirty inodes
680 * Attempts to free all inodes for a given superblock. If there were any
681 * busy inodes return a non-zero value, else zero.
682 * If @kill_dirty is set, discard dirty inodes too, otherwise treat
685 int invalidate_inodes(struct super_block
*sb
, bool kill_dirty
)
688 struct inode
*inode
, *next
;
692 spin_lock(&sb
->s_inode_list_lock
);
693 list_for_each_entry_safe(inode
, next
, &sb
->s_inodes
, i_sb_list
) {
694 spin_lock(&inode
->i_lock
);
695 if (inode
->i_state
& (I_NEW
| I_FREEING
| I_WILL_FREE
)) {
696 spin_unlock(&inode
->i_lock
);
699 if (inode
->i_state
& I_DIRTY_ALL
&& !kill_dirty
) {
700 spin_unlock(&inode
->i_lock
);
704 if (atomic_read(&inode
->i_count
)) {
705 spin_unlock(&inode
->i_lock
);
710 inode
->i_state
|= I_FREEING
;
711 inode_lru_list_del(inode
);
712 spin_unlock(&inode
->i_lock
);
713 list_add(&inode
->i_lru
, &dispose
);
714 if (need_resched()) {
715 spin_unlock(&sb
->s_inode_list_lock
);
717 dispose_list(&dispose
);
721 spin_unlock(&sb
->s_inode_list_lock
);
723 dispose_list(&dispose
);
729 * Isolate the inode from the LRU in preparation for freeing it.
731 * Any inodes which are pinned purely because of attached pagecache have their
732 * pagecache removed. If the inode has metadata buffers attached to
733 * mapping->private_list then try to remove them.
735 * If the inode has the I_REFERENCED flag set, then it means that it has been
736 * used recently - the flag is set in iput_final(). When we encounter such an
737 * inode, clear the flag and move it to the back of the LRU so it gets another
738 * pass through the LRU before it gets reclaimed. This is necessary because of
739 * the fact we are doing lazy LRU updates to minimise lock contention so the
740 * LRU does not have strict ordering. Hence we don't want to reclaim inodes
741 * with this flag set because they are the inodes that are out of order.
743 static enum lru_status
inode_lru_isolate(struct list_head
*item
,
744 struct list_lru_one
*lru
, spinlock_t
*lru_lock
, void *arg
)
746 struct list_head
*freeable
= arg
;
747 struct inode
*inode
= container_of(item
, struct inode
, i_lru
);
750 * we are inverting the lru lock/inode->i_lock here, so use a trylock.
751 * If we fail to get the lock, just skip it.
753 if (!spin_trylock(&inode
->i_lock
))
757 * Referenced or dirty inodes are still in use. Give them another pass
758 * through the LRU as we canot reclaim them now.
760 if (atomic_read(&inode
->i_count
) ||
761 (inode
->i_state
& ~I_REFERENCED
)) {
762 list_lru_isolate(lru
, &inode
->i_lru
);
763 spin_unlock(&inode
->i_lock
);
764 this_cpu_dec(nr_unused
);
768 /* recently referenced inodes get one more pass */
769 if (inode
->i_state
& I_REFERENCED
) {
770 inode
->i_state
&= ~I_REFERENCED
;
771 spin_unlock(&inode
->i_lock
);
775 if (inode_has_buffers(inode
) || !mapping_empty(&inode
->i_data
)) {
777 spin_unlock(&inode
->i_lock
);
778 spin_unlock(lru_lock
);
779 if (remove_inode_buffers(inode
)) {
781 reap
= invalidate_mapping_pages(&inode
->i_data
, 0, -1);
782 if (current_is_kswapd())
783 __count_vm_events(KSWAPD_INODESTEAL
, reap
);
785 __count_vm_events(PGINODESTEAL
, reap
);
786 if (current
->reclaim_state
)
787 current
->reclaim_state
->reclaimed_slab
+= reap
;
794 WARN_ON(inode
->i_state
& I_NEW
);
795 inode
->i_state
|= I_FREEING
;
796 list_lru_isolate_move(lru
, &inode
->i_lru
, freeable
);
797 spin_unlock(&inode
->i_lock
);
799 this_cpu_dec(nr_unused
);
804 * Walk the superblock inode LRU for freeable inodes and attempt to free them.
805 * This is called from the superblock shrinker function with a number of inodes
806 * to trim from the LRU. Inodes to be freed are moved to a temporary list and
807 * then are freed outside inode_lock by dispose_list().
809 long prune_icache_sb(struct super_block
*sb
, struct shrink_control
*sc
)
814 freed
= list_lru_shrink_walk(&sb
->s_inode_lru
, sc
,
815 inode_lru_isolate
, &freeable
);
816 dispose_list(&freeable
);
820 static void __wait_on_freeing_inode(struct inode
*inode
);
822 * Called with the inode lock held.
824 static struct inode
*find_inode(struct super_block
*sb
,
825 struct hlist_head
*head
,
826 int (*test
)(struct inode
*, void *),
829 struct inode
*inode
= NULL
;
832 hlist_for_each_entry(inode
, head
, i_hash
) {
833 if (inode
->i_sb
!= sb
)
835 if (!test(inode
, data
))
837 spin_lock(&inode
->i_lock
);
838 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
839 __wait_on_freeing_inode(inode
);
842 if (unlikely(inode
->i_state
& I_CREATING
)) {
843 spin_unlock(&inode
->i_lock
);
844 return ERR_PTR(-ESTALE
);
847 spin_unlock(&inode
->i_lock
);
854 * find_inode_fast is the fast path version of find_inode, see the comment at
855 * iget_locked for details.
857 static struct inode
*find_inode_fast(struct super_block
*sb
,
858 struct hlist_head
*head
, unsigned long ino
)
860 struct inode
*inode
= NULL
;
863 hlist_for_each_entry(inode
, head
, i_hash
) {
864 if (inode
->i_ino
!= ino
)
866 if (inode
->i_sb
!= sb
)
868 spin_lock(&inode
->i_lock
);
869 if (inode
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
870 __wait_on_freeing_inode(inode
);
873 if (unlikely(inode
->i_state
& I_CREATING
)) {
874 spin_unlock(&inode
->i_lock
);
875 return ERR_PTR(-ESTALE
);
878 spin_unlock(&inode
->i_lock
);
885 * Each cpu owns a range of LAST_INO_BATCH numbers.
886 * 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations,
887 * to renew the exhausted range.
889 * This does not significantly increase overflow rate because every CPU can
890 * consume at most LAST_INO_BATCH-1 unused inode numbers. So there is
891 * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the
892 * 2^32 range, and is a worst-case. Even a 50% wastage would only increase
893 * overflow rate by 2x, which does not seem too significant.
895 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
896 * error if st_ino won't fit in target struct field. Use 32bit counter
897 * here to attempt to avoid that.
899 #define LAST_INO_BATCH 1024
900 static DEFINE_PER_CPU(unsigned int, last_ino
);
902 unsigned int get_next_ino(void)
904 unsigned int *p
= &get_cpu_var(last_ino
);
905 unsigned int res
= *p
;
908 if (unlikely((res
& (LAST_INO_BATCH
-1)) == 0)) {
909 static atomic_t shared_last_ino
;
910 int next
= atomic_add_return(LAST_INO_BATCH
, &shared_last_ino
);
912 res
= next
- LAST_INO_BATCH
;
917 /* get_next_ino should not provide a 0 inode number */
921 put_cpu_var(last_ino
);
924 EXPORT_SYMBOL(get_next_ino
);
927 * new_inode_pseudo - obtain an inode
930 * Allocates a new inode for given superblock.
931 * Inode wont be chained in superblock s_inodes list
933 * - fs can't be unmount
934 * - quotas, fsnotify, writeback can't work
936 struct inode
*new_inode_pseudo(struct super_block
*sb
)
938 struct inode
*inode
= alloc_inode(sb
);
941 spin_lock(&inode
->i_lock
);
943 spin_unlock(&inode
->i_lock
);
944 INIT_LIST_HEAD(&inode
->i_sb_list
);
950 * new_inode - obtain an inode
953 * Allocates a new inode for given superblock. The default gfp_mask
954 * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE.
955 * If HIGHMEM pages are unsuitable or it is known that pages allocated
956 * for the page cache are not reclaimable or migratable,
957 * mapping_set_gfp_mask() must be called with suitable flags on the
958 * newly created inode's mapping
961 struct inode
*new_inode(struct super_block
*sb
)
965 spin_lock_prefetch(&sb
->s_inode_list_lock
);
967 inode
= new_inode_pseudo(sb
);
969 inode_sb_list_add(inode
);
972 EXPORT_SYMBOL(new_inode
);
974 #ifdef CONFIG_DEBUG_LOCK_ALLOC
975 void lockdep_annotate_inode_mutex_key(struct inode
*inode
)
977 if (S_ISDIR(inode
->i_mode
)) {
978 struct file_system_type
*type
= inode
->i_sb
->s_type
;
980 /* Set new key only if filesystem hasn't already changed it */
981 if (lockdep_match_class(&inode
->i_rwsem
, &type
->i_mutex_key
)) {
983 * ensure nobody is actually holding i_mutex
985 // mutex_destroy(&inode->i_mutex);
986 init_rwsem(&inode
->i_rwsem
);
987 lockdep_set_class(&inode
->i_rwsem
,
988 &type
->i_mutex_dir_key
);
992 EXPORT_SYMBOL(lockdep_annotate_inode_mutex_key
);
996 * unlock_new_inode - clear the I_NEW state and wake up any waiters
997 * @inode: new inode to unlock
999 * Called when the inode is fully initialised to clear the new state of the
1000 * inode and wake up anyone waiting for the inode to finish initialisation.
1002 void unlock_new_inode(struct inode
*inode
)
1004 lockdep_annotate_inode_mutex_key(inode
);
1005 spin_lock(&inode
->i_lock
);
1006 WARN_ON(!(inode
->i_state
& I_NEW
));
1007 inode
->i_state
&= ~I_NEW
& ~I_CREATING
;
1009 wake_up_bit(&inode
->i_state
, __I_NEW
);
1010 spin_unlock(&inode
->i_lock
);
1012 EXPORT_SYMBOL(unlock_new_inode
);
1014 void discard_new_inode(struct inode
*inode
)
1016 lockdep_annotate_inode_mutex_key(inode
);
1017 spin_lock(&inode
->i_lock
);
1018 WARN_ON(!(inode
->i_state
& I_NEW
));
1019 inode
->i_state
&= ~I_NEW
;
1021 wake_up_bit(&inode
->i_state
, __I_NEW
);
1022 spin_unlock(&inode
->i_lock
);
1025 EXPORT_SYMBOL(discard_new_inode
);
1028 * lock_two_nondirectories - take two i_mutexes on non-directory objects
1030 * Lock any non-NULL argument that is not a directory.
1031 * Zero, one or two objects may be locked by this function.
1033 * @inode1: first inode to lock
1034 * @inode2: second inode to lock
1036 void lock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
1038 if (inode1
> inode2
)
1039 swap(inode1
, inode2
);
1041 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
1043 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
1044 inode_lock_nested(inode2
, I_MUTEX_NONDIR2
);
1046 EXPORT_SYMBOL(lock_two_nondirectories
);
1049 * unlock_two_nondirectories - release locks from lock_two_nondirectories()
1050 * @inode1: first inode to unlock
1051 * @inode2: second inode to unlock
1053 void unlock_two_nondirectories(struct inode
*inode1
, struct inode
*inode2
)
1055 if (inode1
&& !S_ISDIR(inode1
->i_mode
))
1056 inode_unlock(inode1
);
1057 if (inode2
&& !S_ISDIR(inode2
->i_mode
) && inode2
!= inode1
)
1058 inode_unlock(inode2
);
1060 EXPORT_SYMBOL(unlock_two_nondirectories
);
1063 * inode_insert5 - obtain an inode from a mounted file system
1064 * @inode: pre-allocated inode to use for insert to cache
1065 * @hashval: hash value (usually inode number) to get
1066 * @test: callback used for comparisons between inodes
1067 * @set: callback used to initialize a new struct inode
1068 * @data: opaque data pointer to pass to @test and @set
1070 * Search for the inode specified by @hashval and @data in the inode cache,
1071 * and if present it is return it with an increased reference count. This is
1072 * a variant of iget5_locked() for callers that don't want to fail on memory
1073 * allocation of inode.
1075 * If the inode is not in cache, insert the pre-allocated inode to cache and
1076 * return it locked, hashed, and with the I_NEW flag set. The file system gets
1077 * to fill it in before unlocking it via unlock_new_inode().
1079 * Note both @test and @set are called with the inode_hash_lock held, so can't
1082 struct inode
*inode_insert5(struct inode
*inode
, unsigned long hashval
,
1083 int (*test
)(struct inode
*, void *),
1084 int (*set
)(struct inode
*, void *), void *data
)
1086 struct hlist_head
*head
= inode_hashtable
+ hash(inode
->i_sb
, hashval
);
1088 bool creating
= inode
->i_state
& I_CREATING
;
1091 spin_lock(&inode_hash_lock
);
1092 old
= find_inode(inode
->i_sb
, head
, test
, data
);
1093 if (unlikely(old
)) {
1095 * Uhhuh, somebody else created the same inode under us.
1096 * Use the old inode instead of the preallocated one.
1098 spin_unlock(&inode_hash_lock
);
1102 if (unlikely(inode_unhashed(old
))) {
1109 if (set
&& unlikely(set(inode
, data
))) {
1115 * Return the locked inode with I_NEW set, the
1116 * caller is responsible for filling in the contents
1118 spin_lock(&inode
->i_lock
);
1119 inode
->i_state
|= I_NEW
;
1120 hlist_add_head_rcu(&inode
->i_hash
, head
);
1121 spin_unlock(&inode
->i_lock
);
1123 inode_sb_list_add(inode
);
1125 spin_unlock(&inode_hash_lock
);
1129 EXPORT_SYMBOL(inode_insert5
);
1132 * iget5_locked - obtain an inode from a mounted file system
1133 * @sb: super block of file system
1134 * @hashval: hash value (usually inode number) to get
1135 * @test: callback used for comparisons between inodes
1136 * @set: callback used to initialize a new struct inode
1137 * @data: opaque data pointer to pass to @test and @set
1139 * Search for the inode specified by @hashval and @data in the inode cache,
1140 * and if present it is return it with an increased reference count. This is
1141 * a generalized version of iget_locked() for file systems where the inode
1142 * number is not sufficient for unique identification of an inode.
1144 * If the inode is not in cache, allocate a new inode and return it locked,
1145 * hashed, and with the I_NEW flag set. The file system gets to fill it in
1146 * before unlocking it via unlock_new_inode().
1148 * Note both @test and @set are called with the inode_hash_lock held, so can't
1151 struct inode
*iget5_locked(struct super_block
*sb
, unsigned long hashval
,
1152 int (*test
)(struct inode
*, void *),
1153 int (*set
)(struct inode
*, void *), void *data
)
1155 struct inode
*inode
= ilookup5(sb
, hashval
, test
, data
);
1158 struct inode
*new = alloc_inode(sb
);
1162 inode
= inode_insert5(new, hashval
, test
, set
, data
);
1163 if (unlikely(inode
!= new))
1169 EXPORT_SYMBOL(iget5_locked
);
1172 * iget_locked - obtain an inode from a mounted file system
1173 * @sb: super block of file system
1174 * @ino: inode number to get
1176 * Search for the inode specified by @ino in the inode cache and if present
1177 * return it with an increased reference count. This is for file systems
1178 * where the inode number is sufficient for unique identification of an inode.
1180 * If the inode is not in cache, allocate a new inode and return it locked,
1181 * hashed, and with the I_NEW flag set. The file system gets to fill it in
1182 * before unlocking it via unlock_new_inode().
1184 struct inode
*iget_locked(struct super_block
*sb
, unsigned long ino
)
1186 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1187 struct inode
*inode
;
1189 spin_lock(&inode_hash_lock
);
1190 inode
= find_inode_fast(sb
, head
, ino
);
1191 spin_unlock(&inode_hash_lock
);
1195 wait_on_inode(inode
);
1196 if (unlikely(inode_unhashed(inode
))) {
1203 inode
= alloc_inode(sb
);
1207 spin_lock(&inode_hash_lock
);
1208 /* We released the lock, so.. */
1209 old
= find_inode_fast(sb
, head
, ino
);
1212 spin_lock(&inode
->i_lock
);
1213 inode
->i_state
= I_NEW
;
1214 hlist_add_head_rcu(&inode
->i_hash
, head
);
1215 spin_unlock(&inode
->i_lock
);
1216 inode_sb_list_add(inode
);
1217 spin_unlock(&inode_hash_lock
);
1219 /* Return the locked inode with I_NEW set, the
1220 * caller is responsible for filling in the contents
1226 * Uhhuh, somebody else created the same inode under
1227 * us. Use the old inode instead of the one we just
1230 spin_unlock(&inode_hash_lock
);
1231 destroy_inode(inode
);
1235 wait_on_inode(inode
);
1236 if (unlikely(inode_unhashed(inode
))) {
1243 EXPORT_SYMBOL(iget_locked
);
1246 * search the inode cache for a matching inode number.
1247 * If we find one, then the inode number we are trying to
1248 * allocate is not unique and so we should not use it.
1250 * Returns 1 if the inode number is unique, 0 if it is not.
1252 static int test_inode_iunique(struct super_block
*sb
, unsigned long ino
)
1254 struct hlist_head
*b
= inode_hashtable
+ hash(sb
, ino
);
1255 struct inode
*inode
;
1257 hlist_for_each_entry_rcu(inode
, b
, i_hash
) {
1258 if (inode
->i_ino
== ino
&& inode
->i_sb
== sb
)
1265 * iunique - get a unique inode number
1267 * @max_reserved: highest reserved inode number
1269 * Obtain an inode number that is unique on the system for a given
1270 * superblock. This is used by file systems that have no natural
1271 * permanent inode numbering system. An inode number is returned that
1272 * is higher than the reserved limit but unique.
1275 * With a large number of inodes live on the file system this function
1276 * currently becomes quite slow.
1278 ino_t
iunique(struct super_block
*sb
, ino_t max_reserved
)
1281 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
1282 * error if st_ino won't fit in target struct field. Use 32bit counter
1283 * here to attempt to avoid that.
1285 static DEFINE_SPINLOCK(iunique_lock
);
1286 static unsigned int counter
;
1290 spin_lock(&iunique_lock
);
1292 if (counter
<= max_reserved
)
1293 counter
= max_reserved
+ 1;
1295 } while (!test_inode_iunique(sb
, res
));
1296 spin_unlock(&iunique_lock
);
1301 EXPORT_SYMBOL(iunique
);
1303 struct inode
*igrab(struct inode
*inode
)
1305 spin_lock(&inode
->i_lock
);
1306 if (!(inode
->i_state
& (I_FREEING
|I_WILL_FREE
))) {
1308 spin_unlock(&inode
->i_lock
);
1310 spin_unlock(&inode
->i_lock
);
1312 * Handle the case where s_op->clear_inode is not been
1313 * called yet, and somebody is calling igrab
1314 * while the inode is getting freed.
1320 EXPORT_SYMBOL(igrab
);
1323 * ilookup5_nowait - search for an inode in the inode cache
1324 * @sb: super block of file system to search
1325 * @hashval: hash value (usually inode number) to search for
1326 * @test: callback used for comparisons between inodes
1327 * @data: opaque data pointer to pass to @test
1329 * Search for the inode specified by @hashval and @data in the inode cache.
1330 * If the inode is in the cache, the inode is returned with an incremented
1333 * Note: I_NEW is not waited upon so you have to be very careful what you do
1334 * with the returned inode. You probably should be using ilookup5() instead.
1336 * Note2: @test is called with the inode_hash_lock held, so can't sleep.
1338 struct inode
*ilookup5_nowait(struct super_block
*sb
, unsigned long hashval
,
1339 int (*test
)(struct inode
*, void *), void *data
)
1341 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1342 struct inode
*inode
;
1344 spin_lock(&inode_hash_lock
);
1345 inode
= find_inode(sb
, head
, test
, data
);
1346 spin_unlock(&inode_hash_lock
);
1348 return IS_ERR(inode
) ? NULL
: inode
;
1350 EXPORT_SYMBOL(ilookup5_nowait
);
1353 * ilookup5 - search for an inode in the inode cache
1354 * @sb: super block of file system to search
1355 * @hashval: hash value (usually inode number) to search for
1356 * @test: callback used for comparisons between inodes
1357 * @data: opaque data pointer to pass to @test
1359 * Search for the inode specified by @hashval and @data in the inode cache,
1360 * and if the inode is in the cache, return the inode with an incremented
1361 * reference count. Waits on I_NEW before returning the inode.
1362 * returned with an incremented reference count.
1364 * This is a generalized version of ilookup() for file systems where the
1365 * inode number is not sufficient for unique identification of an inode.
1367 * Note: @test is called with the inode_hash_lock held, so can't sleep.
1369 struct inode
*ilookup5(struct super_block
*sb
, unsigned long hashval
,
1370 int (*test
)(struct inode
*, void *), void *data
)
1372 struct inode
*inode
;
1374 inode
= ilookup5_nowait(sb
, hashval
, test
, data
);
1376 wait_on_inode(inode
);
1377 if (unlikely(inode_unhashed(inode
))) {
1384 EXPORT_SYMBOL(ilookup5
);
1387 * ilookup - search for an inode in the inode cache
1388 * @sb: super block of file system to search
1389 * @ino: inode number to search for
1391 * Search for the inode @ino in the inode cache, and if the inode is in the
1392 * cache, the inode is returned with an incremented reference count.
1394 struct inode
*ilookup(struct super_block
*sb
, unsigned long ino
)
1396 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1397 struct inode
*inode
;
1399 spin_lock(&inode_hash_lock
);
1400 inode
= find_inode_fast(sb
, head
, ino
);
1401 spin_unlock(&inode_hash_lock
);
1406 wait_on_inode(inode
);
1407 if (unlikely(inode_unhashed(inode
))) {
1414 EXPORT_SYMBOL(ilookup
);
1417 * find_inode_nowait - find an inode in the inode cache
1418 * @sb: super block of file system to search
1419 * @hashval: hash value (usually inode number) to search for
1420 * @match: callback used for comparisons between inodes
1421 * @data: opaque data pointer to pass to @match
1423 * Search for the inode specified by @hashval and @data in the inode
1424 * cache, where the helper function @match will return 0 if the inode
1425 * does not match, 1 if the inode does match, and -1 if the search
1426 * should be stopped. The @match function must be responsible for
1427 * taking the i_lock spin_lock and checking i_state for an inode being
1428 * freed or being initialized, and incrementing the reference count
1429 * before returning 1. It also must not sleep, since it is called with
1430 * the inode_hash_lock spinlock held.
1432 * This is a even more generalized version of ilookup5() when the
1433 * function must never block --- find_inode() can block in
1434 * __wait_on_freeing_inode() --- or when the caller can not increment
1435 * the reference count because the resulting iput() might cause an
1436 * inode eviction. The tradeoff is that the @match funtion must be
1437 * very carefully implemented.
1439 struct inode
*find_inode_nowait(struct super_block
*sb
,
1440 unsigned long hashval
,
1441 int (*match
)(struct inode
*, unsigned long,
1445 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1446 struct inode
*inode
, *ret_inode
= NULL
;
1449 spin_lock(&inode_hash_lock
);
1450 hlist_for_each_entry(inode
, head
, i_hash
) {
1451 if (inode
->i_sb
!= sb
)
1453 mval
= match(inode
, hashval
, data
);
1461 spin_unlock(&inode_hash_lock
);
1464 EXPORT_SYMBOL(find_inode_nowait
);
1467 * find_inode_rcu - find an inode in the inode cache
1468 * @sb: Super block of file system to search
1469 * @hashval: Key to hash
1470 * @test: Function to test match on an inode
1471 * @data: Data for test function
1473 * Search for the inode specified by @hashval and @data in the inode cache,
1474 * where the helper function @test will return 0 if the inode does not match
1475 * and 1 if it does. The @test function must be responsible for taking the
1476 * i_lock spin_lock and checking i_state for an inode being freed or being
1479 * If successful, this will return the inode for which the @test function
1480 * returned 1 and NULL otherwise.
1482 * The @test function is not permitted to take a ref on any inode presented.
1483 * It is also not permitted to sleep.
1485 * The caller must hold the RCU read lock.
1487 struct inode
*find_inode_rcu(struct super_block
*sb
, unsigned long hashval
,
1488 int (*test
)(struct inode
*, void *), void *data
)
1490 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, hashval
);
1491 struct inode
*inode
;
1493 RCU_LOCKDEP_WARN(!rcu_read_lock_held(),
1494 "suspicious find_inode_rcu() usage");
1496 hlist_for_each_entry_rcu(inode
, head
, i_hash
) {
1497 if (inode
->i_sb
== sb
&&
1498 !(READ_ONCE(inode
->i_state
) & (I_FREEING
| I_WILL_FREE
)) &&
1504 EXPORT_SYMBOL(find_inode_rcu
);
1507 * find_inode_by_ino_rcu - Find an inode in the inode cache
1508 * @sb: Super block of file system to search
1509 * @ino: The inode number to match
1511 * Search for the inode specified by @hashval and @data in the inode cache,
1512 * where the helper function @test will return 0 if the inode does not match
1513 * and 1 if it does. The @test function must be responsible for taking the
1514 * i_lock spin_lock and checking i_state for an inode being freed or being
1517 * If successful, this will return the inode for which the @test function
1518 * returned 1 and NULL otherwise.
1520 * The @test function is not permitted to take a ref on any inode presented.
1521 * It is also not permitted to sleep.
1523 * The caller must hold the RCU read lock.
1525 struct inode
*find_inode_by_ino_rcu(struct super_block
*sb
,
1528 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1529 struct inode
*inode
;
1531 RCU_LOCKDEP_WARN(!rcu_read_lock_held(),
1532 "suspicious find_inode_by_ino_rcu() usage");
1534 hlist_for_each_entry_rcu(inode
, head
, i_hash
) {
1535 if (inode
->i_ino
== ino
&&
1536 inode
->i_sb
== sb
&&
1537 !(READ_ONCE(inode
->i_state
) & (I_FREEING
| I_WILL_FREE
)))
1542 EXPORT_SYMBOL(find_inode_by_ino_rcu
);
1544 int insert_inode_locked(struct inode
*inode
)
1546 struct super_block
*sb
= inode
->i_sb
;
1547 ino_t ino
= inode
->i_ino
;
1548 struct hlist_head
*head
= inode_hashtable
+ hash(sb
, ino
);
1551 struct inode
*old
= NULL
;
1552 spin_lock(&inode_hash_lock
);
1553 hlist_for_each_entry(old
, head
, i_hash
) {
1554 if (old
->i_ino
!= ino
)
1556 if (old
->i_sb
!= sb
)
1558 spin_lock(&old
->i_lock
);
1559 if (old
->i_state
& (I_FREEING
|I_WILL_FREE
)) {
1560 spin_unlock(&old
->i_lock
);
1566 spin_lock(&inode
->i_lock
);
1567 inode
->i_state
|= I_NEW
| I_CREATING
;
1568 hlist_add_head_rcu(&inode
->i_hash
, head
);
1569 spin_unlock(&inode
->i_lock
);
1570 spin_unlock(&inode_hash_lock
);
1573 if (unlikely(old
->i_state
& I_CREATING
)) {
1574 spin_unlock(&old
->i_lock
);
1575 spin_unlock(&inode_hash_lock
);
1579 spin_unlock(&old
->i_lock
);
1580 spin_unlock(&inode_hash_lock
);
1582 if (unlikely(!inode_unhashed(old
))) {
1589 EXPORT_SYMBOL(insert_inode_locked
);
1591 int insert_inode_locked4(struct inode
*inode
, unsigned long hashval
,
1592 int (*test
)(struct inode
*, void *), void *data
)
1596 inode
->i_state
|= I_CREATING
;
1597 old
= inode_insert5(inode
, hashval
, test
, NULL
, data
);
1605 EXPORT_SYMBOL(insert_inode_locked4
);
1608 int generic_delete_inode(struct inode
*inode
)
1612 EXPORT_SYMBOL(generic_delete_inode
);
1615 * Called when we're dropping the last reference
1618 * Call the FS "drop_inode()" function, defaulting to
1619 * the legacy UNIX filesystem behaviour. If it tells
1620 * us to evict inode, do so. Otherwise, retain inode
1621 * in cache if fs is alive, sync and evict if fs is
1624 static void iput_final(struct inode
*inode
)
1626 struct super_block
*sb
= inode
->i_sb
;
1627 const struct super_operations
*op
= inode
->i_sb
->s_op
;
1628 unsigned long state
;
1631 WARN_ON(inode
->i_state
& I_NEW
);
1634 drop
= op
->drop_inode(inode
);
1636 drop
= generic_drop_inode(inode
);
1639 !(inode
->i_state
& I_DONTCACHE
) &&
1640 (sb
->s_flags
& SB_ACTIVE
)) {
1641 inode_add_lru(inode
);
1642 spin_unlock(&inode
->i_lock
);
1646 state
= inode
->i_state
;
1648 WRITE_ONCE(inode
->i_state
, state
| I_WILL_FREE
);
1649 spin_unlock(&inode
->i_lock
);
1651 write_inode_now(inode
, 1);
1653 spin_lock(&inode
->i_lock
);
1654 state
= inode
->i_state
;
1655 WARN_ON(state
& I_NEW
);
1656 state
&= ~I_WILL_FREE
;
1659 WRITE_ONCE(inode
->i_state
, state
| I_FREEING
);
1660 if (!list_empty(&inode
->i_lru
))
1661 inode_lru_list_del(inode
);
1662 spin_unlock(&inode
->i_lock
);
1668 * iput - put an inode
1669 * @inode: inode to put
1671 * Puts an inode, dropping its usage count. If the inode use count hits
1672 * zero, the inode is then freed and may also be destroyed.
1674 * Consequently, iput() can sleep.
1676 void iput(struct inode
*inode
)
1680 BUG_ON(inode
->i_state
& I_CLEAR
);
1682 if (atomic_dec_and_lock(&inode
->i_count
, &inode
->i_lock
)) {
1683 if (inode
->i_nlink
&& (inode
->i_state
& I_DIRTY_TIME
)) {
1684 atomic_inc(&inode
->i_count
);
1685 spin_unlock(&inode
->i_lock
);
1686 trace_writeback_lazytime_iput(inode
);
1687 mark_inode_dirty_sync(inode
);
1693 EXPORT_SYMBOL(iput
);
1697 * bmap - find a block number in a file
1698 * @inode: inode owning the block number being requested
1699 * @block: pointer containing the block to find
1701 * Replaces the value in ``*block`` with the block number on the device holding
1702 * corresponding to the requested block number in the file.
1703 * That is, asked for block 4 of inode 1 the function will replace the
1704 * 4 in ``*block``, with disk block relative to the disk start that holds that
1705 * block of the file.
1707 * Returns -EINVAL in case of error, 0 otherwise. If mapping falls into a
1708 * hole, returns 0 and ``*block`` is also set to 0.
1710 int bmap(struct inode
*inode
, sector_t
*block
)
1712 if (!inode
->i_mapping
->a_ops
->bmap
)
1715 *block
= inode
->i_mapping
->a_ops
->bmap(inode
->i_mapping
, *block
);
1718 EXPORT_SYMBOL(bmap
);
1722 * With relative atime, only update atime if the previous atime is
1723 * earlier than either the ctime or mtime or if at least a day has
1724 * passed since the last atime update.
1726 static int relatime_need_update(struct vfsmount
*mnt
, struct inode
*inode
,
1727 struct timespec64 now
)
1730 if (!(mnt
->mnt_flags
& MNT_RELATIME
))
1733 * Is mtime younger than atime? If yes, update atime:
1735 if (timespec64_compare(&inode
->i_mtime
, &inode
->i_atime
) >= 0)
1738 * Is ctime younger than atime? If yes, update atime:
1740 if (timespec64_compare(&inode
->i_ctime
, &inode
->i_atime
) >= 0)
1744 * Is the previous atime value older than a day? If yes,
1747 if ((long)(now
.tv_sec
- inode
->i_atime
.tv_sec
) >= 24*60*60)
1750 * Good, we can skip the atime update:
1755 int generic_update_time(struct inode
*inode
, struct timespec64
*time
, int flags
)
1757 int dirty_flags
= 0;
1759 if (flags
& (S_ATIME
| S_CTIME
| S_MTIME
)) {
1760 if (flags
& S_ATIME
)
1761 inode
->i_atime
= *time
;
1762 if (flags
& S_CTIME
)
1763 inode
->i_ctime
= *time
;
1764 if (flags
& S_MTIME
)
1765 inode
->i_mtime
= *time
;
1767 if (inode
->i_sb
->s_flags
& SB_LAZYTIME
)
1768 dirty_flags
|= I_DIRTY_TIME
;
1770 dirty_flags
|= I_DIRTY_SYNC
;
1773 if ((flags
& S_VERSION
) && inode_maybe_inc_iversion(inode
, false))
1774 dirty_flags
|= I_DIRTY_SYNC
;
1776 __mark_inode_dirty(inode
, dirty_flags
);
1779 EXPORT_SYMBOL(generic_update_time
);
1782 * This does the actual work of updating an inodes time or version. Must have
1783 * had called mnt_want_write() before calling this.
1785 int inode_update_time(struct inode
*inode
, struct timespec64
*time
, int flags
)
1787 if (inode
->i_op
->update_time
)
1788 return inode
->i_op
->update_time(inode
, time
, flags
);
1789 return generic_update_time(inode
, time
, flags
);
1791 EXPORT_SYMBOL(inode_update_time
);
1794 * atime_needs_update - update the access time
1795 * @path: the &struct path to update
1796 * @inode: inode to update
1798 * Update the accessed time on an inode and mark it for writeback.
1799 * This function automatically handles read only file systems and media,
1800 * as well as the "noatime" flag and inode specific "noatime" markers.
1802 bool atime_needs_update(const struct path
*path
, struct inode
*inode
)
1804 struct vfsmount
*mnt
= path
->mnt
;
1805 struct timespec64 now
;
1807 if (inode
->i_flags
& S_NOATIME
)
1810 /* Atime updates will likely cause i_uid and i_gid to be written
1811 * back improprely if their true value is unknown to the vfs.
1813 if (HAS_UNMAPPED_ID(mnt_user_ns(mnt
), inode
))
1816 if (IS_NOATIME(inode
))
1818 if ((inode
->i_sb
->s_flags
& SB_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1821 if (mnt
->mnt_flags
& MNT_NOATIME
)
1823 if ((mnt
->mnt_flags
& MNT_NODIRATIME
) && S_ISDIR(inode
->i_mode
))
1826 now
= current_time(inode
);
1828 if (!relatime_need_update(mnt
, inode
, now
))
1831 if (timespec64_equal(&inode
->i_atime
, &now
))
1837 void touch_atime(const struct path
*path
)
1839 struct vfsmount
*mnt
= path
->mnt
;
1840 struct inode
*inode
= d_inode(path
->dentry
);
1841 struct timespec64 now
;
1843 if (!atime_needs_update(path
, inode
))
1846 if (!sb_start_write_trylock(inode
->i_sb
))
1849 if (__mnt_want_write(mnt
) != 0)
1852 * File systems can error out when updating inodes if they need to
1853 * allocate new space to modify an inode (such is the case for
1854 * Btrfs), but since we touch atime while walking down the path we
1855 * really don't care if we failed to update the atime of the file,
1856 * so just ignore the return value.
1857 * We may also fail on filesystems that have the ability to make parts
1858 * of the fs read only, e.g. subvolumes in Btrfs.
1860 now
= current_time(inode
);
1861 inode_update_time(inode
, &now
, S_ATIME
);
1862 __mnt_drop_write(mnt
);
1864 sb_end_write(inode
->i_sb
);
1866 EXPORT_SYMBOL(touch_atime
);
1869 * The logic we want is
1871 * if suid or (sgid and xgrp)
1874 int should_remove_suid(struct dentry
*dentry
)
1876 umode_t mode
= d_inode(dentry
)->i_mode
;
1879 /* suid always must be killed */
1880 if (unlikely(mode
& S_ISUID
))
1881 kill
= ATTR_KILL_SUID
;
1884 * sgid without any exec bits is just a mandatory locking mark; leave
1885 * it alone. If some exec bits are set, it's a real sgid; kill it.
1887 if (unlikely((mode
& S_ISGID
) && (mode
& S_IXGRP
)))
1888 kill
|= ATTR_KILL_SGID
;
1890 if (unlikely(kill
&& !capable(CAP_FSETID
) && S_ISREG(mode
)))
1895 EXPORT_SYMBOL(should_remove_suid
);
1898 * Return mask of changes for notify_change() that need to be done as a
1899 * response to write or truncate. Return 0 if nothing has to be changed.
1900 * Negative value on error (change should be denied).
1902 int dentry_needs_remove_privs(struct dentry
*dentry
)
1904 struct inode
*inode
= d_inode(dentry
);
1908 if (IS_NOSEC(inode
))
1911 mask
= should_remove_suid(dentry
);
1912 ret
= security_inode_need_killpriv(dentry
);
1916 mask
|= ATTR_KILL_PRIV
;
1920 static int __remove_privs(struct user_namespace
*mnt_userns
,
1921 struct dentry
*dentry
, int kill
)
1923 struct iattr newattrs
;
1925 newattrs
.ia_valid
= ATTR_FORCE
| kill
;
1927 * Note we call this on write, so notify_change will not
1928 * encounter any conflicting delegations:
1930 return notify_change(mnt_userns
, dentry
, &newattrs
, NULL
);
1934 * Remove special file priviledges (suid, capabilities) when file is written
1937 int file_remove_privs(struct file
*file
)
1939 struct dentry
*dentry
= file_dentry(file
);
1940 struct inode
*inode
= file_inode(file
);
1945 * Fast path for nothing security related.
1946 * As well for non-regular files, e.g. blkdev inodes.
1947 * For example, blkdev_write_iter() might get here
1948 * trying to remove privs which it is not allowed to.
1950 if (IS_NOSEC(inode
) || !S_ISREG(inode
->i_mode
))
1953 kill
= dentry_needs_remove_privs(dentry
);
1957 error
= __remove_privs(file_mnt_user_ns(file
), dentry
, kill
);
1959 inode_has_no_xattr(inode
);
1963 EXPORT_SYMBOL(file_remove_privs
);
1966 * file_update_time - update mtime and ctime time
1967 * @file: file accessed
1969 * Update the mtime and ctime members of an inode and mark the inode
1970 * for writeback. Note that this function is meant exclusively for
1971 * usage in the file write path of filesystems, and filesystems may
1972 * choose to explicitly ignore update via this function with the
1973 * S_NOCMTIME inode flag, e.g. for network filesystem where these
1974 * timestamps are handled by the server. This can return an error for
1975 * file systems who need to allocate space in order to update an inode.
1978 int file_update_time(struct file
*file
)
1980 struct inode
*inode
= file_inode(file
);
1981 struct timespec64 now
;
1985 /* First try to exhaust all avenues to not sync */
1986 if (IS_NOCMTIME(inode
))
1989 now
= current_time(inode
);
1990 if (!timespec64_equal(&inode
->i_mtime
, &now
))
1993 if (!timespec64_equal(&inode
->i_ctime
, &now
))
1996 if (IS_I_VERSION(inode
) && inode_iversion_need_inc(inode
))
1997 sync_it
|= S_VERSION
;
2002 /* Finally allowed to write? Takes lock. */
2003 if (__mnt_want_write_file(file
))
2006 ret
= inode_update_time(inode
, &now
, sync_it
);
2007 __mnt_drop_write_file(file
);
2011 EXPORT_SYMBOL(file_update_time
);
2013 /* Caller must hold the file's inode lock */
2014 int file_modified(struct file
*file
)
2019 * Clear the security bits if the process is not being run by root.
2020 * This keeps people from modifying setuid and setgid binaries.
2022 err
= file_remove_privs(file
);
2026 if (unlikely(file
->f_mode
& FMODE_NOCMTIME
))
2029 return file_update_time(file
);
2031 EXPORT_SYMBOL(file_modified
);
2033 int inode_needs_sync(struct inode
*inode
)
2037 if (S_ISDIR(inode
->i_mode
) && IS_DIRSYNC(inode
))
2041 EXPORT_SYMBOL(inode_needs_sync
);
2044 * If we try to find an inode in the inode hash while it is being
2045 * deleted, we have to wait until the filesystem completes its
2046 * deletion before reporting that it isn't found. This function waits
2047 * until the deletion _might_ have completed. Callers are responsible
2048 * to recheck inode state.
2050 * It doesn't matter if I_NEW is not set initially, a call to
2051 * wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list
2054 static void __wait_on_freeing_inode(struct inode
*inode
)
2056 wait_queue_head_t
*wq
;
2057 DEFINE_WAIT_BIT(wait
, &inode
->i_state
, __I_NEW
);
2058 wq
= bit_waitqueue(&inode
->i_state
, __I_NEW
);
2059 prepare_to_wait(wq
, &wait
.wq_entry
, TASK_UNINTERRUPTIBLE
);
2060 spin_unlock(&inode
->i_lock
);
2061 spin_unlock(&inode_hash_lock
);
2063 finish_wait(wq
, &wait
.wq_entry
);
2064 spin_lock(&inode_hash_lock
);
2067 static __initdata
unsigned long ihash_entries
;
2068 static int __init
set_ihash_entries(char *str
)
2072 ihash_entries
= simple_strtoul(str
, &str
, 0);
2075 __setup("ihash_entries=", set_ihash_entries
);
2078 * Initialize the waitqueues and inode hash table.
2080 void __init
inode_init_early(void)
2082 /* If hashes are distributed across NUMA nodes, defer
2083 * hash allocation until vmalloc space is available.
2089 alloc_large_system_hash("Inode-cache",
2090 sizeof(struct hlist_head
),
2093 HASH_EARLY
| HASH_ZERO
,
2100 void __init
inode_init(void)
2102 /* inode slab cache */
2103 inode_cachep
= kmem_cache_create("inode_cache",
2104 sizeof(struct inode
),
2106 (SLAB_RECLAIM_ACCOUNT
|SLAB_PANIC
|
2107 SLAB_MEM_SPREAD
|SLAB_ACCOUNT
),
2110 /* Hash may have been set up in inode_init_early */
2115 alloc_large_system_hash("Inode-cache",
2116 sizeof(struct hlist_head
),
2126 void init_special_inode(struct inode
*inode
, umode_t mode
, dev_t rdev
)
2128 inode
->i_mode
= mode
;
2129 if (S_ISCHR(mode
)) {
2130 inode
->i_fop
= &def_chr_fops
;
2131 inode
->i_rdev
= rdev
;
2132 } else if (S_ISBLK(mode
)) {
2133 inode
->i_fop
= &def_blk_fops
;
2134 inode
->i_rdev
= rdev
;
2135 } else if (S_ISFIFO(mode
))
2136 inode
->i_fop
= &pipefifo_fops
;
2137 else if (S_ISSOCK(mode
))
2138 ; /* leave it no_open_fops */
2140 printk(KERN_DEBUG
"init_special_inode: bogus i_mode (%o) for"
2141 " inode %s:%lu\n", mode
, inode
->i_sb
->s_id
,
2144 EXPORT_SYMBOL(init_special_inode
);
2147 * inode_init_owner - Init uid,gid,mode for new inode according to posix standards
2148 * @mnt_userns: User namespace of the mount the inode was created from
2150 * @dir: Directory inode
2151 * @mode: mode of the new inode
2153 * If the inode has been created through an idmapped mount the user namespace of
2154 * the vfsmount must be passed through @mnt_userns. This function will then take
2155 * care to map the inode according to @mnt_userns before checking permissions
2156 * and initializing i_uid and i_gid. On non-idmapped mounts or if permission
2157 * checking is to be performed on the raw inode simply passs init_user_ns.
2159 void inode_init_owner(struct user_namespace
*mnt_userns
, struct inode
*inode
,
2160 const struct inode
*dir
, umode_t mode
)
2162 inode_fsuid_set(inode
, mnt_userns
);
2163 if (dir
&& dir
->i_mode
& S_ISGID
) {
2164 inode
->i_gid
= dir
->i_gid
;
2166 /* Directories are special, and always inherit S_ISGID */
2169 else if ((mode
& (S_ISGID
| S_IXGRP
)) == (S_ISGID
| S_IXGRP
) &&
2170 !in_group_p(i_gid_into_mnt(mnt_userns
, dir
)) &&
2171 !capable_wrt_inode_uidgid(mnt_userns
, dir
, CAP_FSETID
))
2174 inode_fsgid_set(inode
, mnt_userns
);
2175 inode
->i_mode
= mode
;
2177 EXPORT_SYMBOL(inode_init_owner
);
2180 * inode_owner_or_capable - check current task permissions to inode
2181 * @mnt_userns: user namespace of the mount the inode was found from
2182 * @inode: inode being checked
2184 * Return true if current either has CAP_FOWNER in a namespace with the
2185 * inode owner uid mapped, or owns the file.
2187 * If the inode has been found through an idmapped mount the user namespace of
2188 * the vfsmount must be passed through @mnt_userns. This function will then take
2189 * care to map the inode according to @mnt_userns before checking permissions.
2190 * On non-idmapped mounts or if permission checking is to be performed on the
2191 * raw inode simply passs init_user_ns.
2193 bool inode_owner_or_capable(struct user_namespace
*mnt_userns
,
2194 const struct inode
*inode
)
2197 struct user_namespace
*ns
;
2199 i_uid
= i_uid_into_mnt(mnt_userns
, inode
);
2200 if (uid_eq(current_fsuid(), i_uid
))
2203 ns
= current_user_ns();
2204 if (kuid_has_mapping(ns
, i_uid
) && ns_capable(ns
, CAP_FOWNER
))
2208 EXPORT_SYMBOL(inode_owner_or_capable
);
2211 * Direct i/o helper functions
2213 static void __inode_dio_wait(struct inode
*inode
)
2215 wait_queue_head_t
*wq
= bit_waitqueue(&inode
->i_state
, __I_DIO_WAKEUP
);
2216 DEFINE_WAIT_BIT(q
, &inode
->i_state
, __I_DIO_WAKEUP
);
2219 prepare_to_wait(wq
, &q
.wq_entry
, TASK_UNINTERRUPTIBLE
);
2220 if (atomic_read(&inode
->i_dio_count
))
2222 } while (atomic_read(&inode
->i_dio_count
));
2223 finish_wait(wq
, &q
.wq_entry
);
2227 * inode_dio_wait - wait for outstanding DIO requests to finish
2228 * @inode: inode to wait for
2230 * Waits for all pending direct I/O requests to finish so that we can
2231 * proceed with a truncate or equivalent operation.
2233 * Must be called under a lock that serializes taking new references
2234 * to i_dio_count, usually by inode->i_mutex.
2236 void inode_dio_wait(struct inode
*inode
)
2238 if (atomic_read(&inode
->i_dio_count
))
2239 __inode_dio_wait(inode
);
2241 EXPORT_SYMBOL(inode_dio_wait
);
2244 * inode_set_flags - atomically set some inode flags
2246 * Note: the caller should be holding i_mutex, or else be sure that
2247 * they have exclusive access to the inode structure (i.e., while the
2248 * inode is being instantiated). The reason for the cmpxchg() loop
2249 * --- which wouldn't be necessary if all code paths which modify
2250 * i_flags actually followed this rule, is that there is at least one
2251 * code path which doesn't today so we use cmpxchg() out of an abundance
2254 * In the long run, i_mutex is overkill, and we should probably look
2255 * at using the i_lock spinlock to protect i_flags, and then make sure
2256 * it is so documented in include/linux/fs.h and that all code follows
2257 * the locking convention!!
2259 void inode_set_flags(struct inode
*inode
, unsigned int flags
,
2262 WARN_ON_ONCE(flags
& ~mask
);
2263 set_mask_bits(&inode
->i_flags
, mask
, flags
);
2265 EXPORT_SYMBOL(inode_set_flags
);
2267 void inode_nohighmem(struct inode
*inode
)
2269 mapping_set_gfp_mask(inode
->i_mapping
, GFP_USER
);
2271 EXPORT_SYMBOL(inode_nohighmem
);
2274 * timestamp_truncate - Truncate timespec to a granularity
2276 * @inode: inode being updated
2278 * Truncate a timespec to the granularity supported by the fs
2279 * containing the inode. Always rounds down. gran must
2280 * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns).
2282 struct timespec64
timestamp_truncate(struct timespec64 t
, struct inode
*inode
)
2284 struct super_block
*sb
= inode
->i_sb
;
2285 unsigned int gran
= sb
->s_time_gran
;
2287 t
.tv_sec
= clamp(t
.tv_sec
, sb
->s_time_min
, sb
->s_time_max
);
2288 if (unlikely(t
.tv_sec
== sb
->s_time_max
|| t
.tv_sec
== sb
->s_time_min
))
2291 /* Avoid division in the common cases 1 ns and 1 s. */
2294 else if (gran
== NSEC_PER_SEC
)
2296 else if (gran
> 1 && gran
< NSEC_PER_SEC
)
2297 t
.tv_nsec
-= t
.tv_nsec
% gran
;
2299 WARN(1, "invalid file time granularity: %u", gran
);
2302 EXPORT_SYMBOL(timestamp_truncate
);
2305 * current_time - Return FS time
2308 * Return the current time truncated to the time granularity supported by
2311 * Note that inode and inode->sb cannot be NULL.
2312 * Otherwise, the function warns and returns time without truncation.
2314 struct timespec64
current_time(struct inode
*inode
)
2316 struct timespec64 now
;
2318 ktime_get_coarse_real_ts64(&now
);
2320 if (unlikely(!inode
->i_sb
)) {
2321 WARN(1, "current_time() called with uninitialized super_block in the inode");
2325 return timestamp_truncate(now
, inode
);
2327 EXPORT_SYMBOL(current_time
);