PCI: SR-IOV quirk for Intel 82576 NIC
[linux-2.6/mini2440.git] / fs / inode.c
blobd06d6d268de9a12c5fbe9d66bd618c293729e8e9
1 /*
2 * linux/fs/inode.c
4 * (C) 1997 Linus Torvalds
5 */
7 #include <linux/fs.h>
8 #include <linux/mm.h>
9 #include <linux/dcache.h>
10 #include <linux/init.h>
11 #include <linux/quotaops.h>
12 #include <linux/slab.h>
13 #include <linux/writeback.h>
14 #include <linux/module.h>
15 #include <linux/backing-dev.h>
16 #include <linux/wait.h>
17 #include <linux/hash.h>
18 #include <linux/swap.h>
19 #include <linux/security.h>
20 #include <linux/ima.h>
21 #include <linux/pagemap.h>
22 #include <linux/cdev.h>
23 #include <linux/bootmem.h>
24 #include <linux/inotify.h>
25 #include <linux/mount.h>
26 #include <linux/async.h>
29 * This is needed for the following functions:
30 * - inode_has_buffers
31 * - invalidate_inode_buffers
32 * - invalidate_bdev
34 * FIXME: remove all knowledge of the buffer layer from this file
36 #include <linux/buffer_head.h>
39 * New inode.c implementation.
41 * This implementation has the basic premise of trying
42 * to be extremely low-overhead and SMP-safe, yet be
43 * simple enough to be "obviously correct".
45 * Famous last words.
48 /* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */
50 /* #define INODE_PARANOIA 1 */
51 /* #define INODE_DEBUG 1 */
54 * Inode lookup is no longer as critical as it used to be:
55 * most of the lookups are going to be through the dcache.
57 #define I_HASHBITS i_hash_shift
58 #define I_HASHMASK i_hash_mask
60 static unsigned int i_hash_mask __read_mostly;
61 static unsigned int i_hash_shift __read_mostly;
64 * Each inode can be on two separate lists. One is
65 * the hash list of the inode, used for lookups. The
66 * other linked list is the "type" list:
67 * "in_use" - valid inode, i_count > 0, i_nlink > 0
68 * "dirty" - as "in_use" but also dirty
69 * "unused" - valid inode, i_count = 0
71 * A "dirty" list is maintained for each super block,
72 * allowing for low-overhead inode sync() operations.
75 LIST_HEAD(inode_in_use);
76 LIST_HEAD(inode_unused);
77 static struct hlist_head *inode_hashtable __read_mostly;
80 * A simple spinlock to protect the list manipulations.
82 * NOTE! You also have to own the lock if you change
83 * the i_state of an inode while it is in use..
85 DEFINE_SPINLOCK(inode_lock);
88 * iprune_mutex provides exclusion between the kswapd or try_to_free_pages
89 * icache shrinking path, and the umount path. Without this exclusion,
90 * by the time prune_icache calls iput for the inode whose pages it has
91 * been invalidating, or by the time it calls clear_inode & destroy_inode
92 * from its final dispose_list, the struct super_block they refer to
93 * (for inode->i_sb->s_op) may already have been freed and reused.
95 static DEFINE_MUTEX(iprune_mutex);
98 * Statistics gathering..
100 struct inodes_stat_t inodes_stat;
102 static struct kmem_cache * inode_cachep __read_mostly;
104 static void wake_up_inode(struct inode *inode)
107 * Prevent speculative execution through spin_unlock(&inode_lock);
109 smp_mb();
110 wake_up_bit(&inode->i_state, __I_LOCK);
114 * inode_init_always - perform inode structure intialisation
115 * @sb: superblock inode belongs to
116 * @inode: inode to initialise
118 * These are initializations that need to be done on every inode
119 * allocation as the fields are not initialised by slab allocation.
121 struct inode *inode_init_always(struct super_block *sb, struct inode *inode)
123 static const struct address_space_operations empty_aops;
124 static struct inode_operations empty_iops;
125 static const struct file_operations empty_fops;
127 struct address_space * const mapping = &inode->i_data;
129 inode->i_sb = sb;
130 inode->i_blkbits = sb->s_blocksize_bits;
131 inode->i_flags = 0;
132 atomic_set(&inode->i_count, 1);
133 inode->i_op = &empty_iops;
134 inode->i_fop = &empty_fops;
135 inode->i_nlink = 1;
136 inode->i_uid = 0;
137 inode->i_gid = 0;
138 atomic_set(&inode->i_writecount, 0);
139 inode->i_size = 0;
140 inode->i_blocks = 0;
141 inode->i_bytes = 0;
142 inode->i_generation = 0;
143 #ifdef CONFIG_QUOTA
144 memset(&inode->i_dquot, 0, sizeof(inode->i_dquot));
145 #endif
146 inode->i_pipe = NULL;
147 inode->i_bdev = NULL;
148 inode->i_cdev = NULL;
149 inode->i_rdev = 0;
150 inode->dirtied_when = 0;
152 if (security_inode_alloc(inode))
153 goto out_free_inode;
155 /* allocate and initialize an i_integrity */
156 if (ima_inode_alloc(inode))
157 goto out_free_security;
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 init_rwsem(&inode->i_alloc_sem);
166 lockdep_set_class(&inode->i_alloc_sem, &sb->s_type->i_alloc_sem_key);
168 mapping->a_ops = &empty_aops;
169 mapping->host = inode;
170 mapping->flags = 0;
171 mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE);
172 mapping->assoc_mapping = NULL;
173 mapping->backing_dev_info = &default_backing_dev_info;
174 mapping->writeback_index = 0;
177 * If the block_device provides a backing_dev_info for client
178 * inodes then use that. Otherwise the inode share the bdev's
179 * backing_dev_info.
181 if (sb->s_bdev) {
182 struct backing_dev_info *bdi;
184 bdi = sb->s_bdev->bd_inode_backing_dev_info;
185 if (!bdi)
186 bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
187 mapping->backing_dev_info = bdi;
189 inode->i_private = NULL;
190 inode->i_mapping = mapping;
192 return inode;
194 out_free_security:
195 security_inode_free(inode);
196 out_free_inode:
197 if (inode->i_sb->s_op->destroy_inode)
198 inode->i_sb->s_op->destroy_inode(inode);
199 else
200 kmem_cache_free(inode_cachep, (inode));
201 return NULL;
203 EXPORT_SYMBOL(inode_init_always);
205 static struct inode *alloc_inode(struct super_block *sb)
207 struct inode *inode;
209 if (sb->s_op->alloc_inode)
210 inode = sb->s_op->alloc_inode(sb);
211 else
212 inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL);
214 if (inode)
215 return inode_init_always(sb, inode);
216 return NULL;
219 void destroy_inode(struct inode *inode)
221 BUG_ON(inode_has_buffers(inode));
222 security_inode_free(inode);
223 if (inode->i_sb->s_op->destroy_inode)
224 inode->i_sb->s_op->destroy_inode(inode);
225 else
226 kmem_cache_free(inode_cachep, (inode));
228 EXPORT_SYMBOL(destroy_inode);
232 * These are initializations that only need to be done
233 * once, because the fields are idempotent across use
234 * of the inode, so let the slab aware of that.
236 void inode_init_once(struct inode *inode)
238 memset(inode, 0, sizeof(*inode));
239 INIT_HLIST_NODE(&inode->i_hash);
240 INIT_LIST_HEAD(&inode->i_dentry);
241 INIT_LIST_HEAD(&inode->i_devices);
242 INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
243 spin_lock_init(&inode->i_data.tree_lock);
244 spin_lock_init(&inode->i_data.i_mmap_lock);
245 INIT_LIST_HEAD(&inode->i_data.private_list);
246 spin_lock_init(&inode->i_data.private_lock);
247 INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap);
248 INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear);
249 i_size_ordered_init(inode);
250 #ifdef CONFIG_INOTIFY
251 INIT_LIST_HEAD(&inode->inotify_watches);
252 mutex_init(&inode->inotify_mutex);
253 #endif
256 EXPORT_SYMBOL(inode_init_once);
258 static void init_once(void *foo)
260 struct inode * inode = (struct inode *) foo;
262 inode_init_once(inode);
266 * inode_lock must be held
268 void __iget(struct inode * inode)
270 if (atomic_read(&inode->i_count)) {
271 atomic_inc(&inode->i_count);
272 return;
274 atomic_inc(&inode->i_count);
275 if (!(inode->i_state & (I_DIRTY|I_SYNC)))
276 list_move(&inode->i_list, &inode_in_use);
277 inodes_stat.nr_unused--;
281 * clear_inode - clear an inode
282 * @inode: inode to clear
284 * This is called by the filesystem to tell us
285 * that the inode is no longer useful. We just
286 * terminate it with extreme prejudice.
288 void clear_inode(struct inode *inode)
290 might_sleep();
291 invalidate_inode_buffers(inode);
293 BUG_ON(inode->i_data.nrpages);
294 BUG_ON(!(inode->i_state & I_FREEING));
295 BUG_ON(inode->i_state & I_CLEAR);
296 inode_sync_wait(inode);
297 vfs_dq_drop(inode);
298 if (inode->i_sb->s_op->clear_inode)
299 inode->i_sb->s_op->clear_inode(inode);
300 if (S_ISBLK(inode->i_mode) && inode->i_bdev)
301 bd_forget(inode);
302 if (S_ISCHR(inode->i_mode) && inode->i_cdev)
303 cd_forget(inode);
304 inode->i_state = I_CLEAR;
307 EXPORT_SYMBOL(clear_inode);
310 * dispose_list - dispose of the contents of a local list
311 * @head: the head of the list to free
313 * Dispose-list gets a local list with local inodes in it, so it doesn't
314 * need to worry about list corruption and SMP locks.
316 static void dispose_list(struct list_head *head)
318 int nr_disposed = 0;
320 while (!list_empty(head)) {
321 struct inode *inode;
323 inode = list_first_entry(head, struct inode, i_list);
324 list_del(&inode->i_list);
326 if (inode->i_data.nrpages)
327 truncate_inode_pages(&inode->i_data, 0);
328 clear_inode(inode);
330 spin_lock(&inode_lock);
331 hlist_del_init(&inode->i_hash);
332 list_del_init(&inode->i_sb_list);
333 spin_unlock(&inode_lock);
335 wake_up_inode(inode);
336 destroy_inode(inode);
337 nr_disposed++;
339 spin_lock(&inode_lock);
340 inodes_stat.nr_inodes -= nr_disposed;
341 spin_unlock(&inode_lock);
345 * Invalidate all inodes for a device.
347 static int invalidate_list(struct list_head *head, struct list_head *dispose)
349 struct list_head *next;
350 int busy = 0, count = 0;
352 next = head->next;
353 for (;;) {
354 struct list_head * tmp = next;
355 struct inode * inode;
358 * We can reschedule here without worrying about the list's
359 * consistency because the per-sb list of inodes must not
360 * change during umount anymore, and because iprune_mutex keeps
361 * shrink_icache_memory() away.
363 cond_resched_lock(&inode_lock);
365 next = next->next;
366 if (tmp == head)
367 break;
368 inode = list_entry(tmp, struct inode, i_sb_list);
369 if (inode->i_state & I_NEW)
370 continue;
371 invalidate_inode_buffers(inode);
372 if (!atomic_read(&inode->i_count)) {
373 list_move(&inode->i_list, dispose);
374 WARN_ON(inode->i_state & I_NEW);
375 inode->i_state |= I_FREEING;
376 count++;
377 continue;
379 busy = 1;
381 /* only unused inodes may be cached with i_count zero */
382 inodes_stat.nr_unused -= count;
383 return busy;
387 * invalidate_inodes - discard the inodes on a device
388 * @sb: superblock
390 * Discard all of the inodes for a given superblock. If the discard
391 * fails because there are busy inodes then a non zero value is returned.
392 * If the discard is successful all the inodes have been discarded.
394 int invalidate_inodes(struct super_block * sb)
396 int busy;
397 LIST_HEAD(throw_away);
399 mutex_lock(&iprune_mutex);
400 spin_lock(&inode_lock);
401 inotify_unmount_inodes(&sb->s_inodes);
402 busy = invalidate_list(&sb->s_inodes, &throw_away);
403 spin_unlock(&inode_lock);
405 dispose_list(&throw_away);
406 mutex_unlock(&iprune_mutex);
408 return busy;
411 EXPORT_SYMBOL(invalidate_inodes);
413 static int can_unuse(struct inode *inode)
415 if (inode->i_state)
416 return 0;
417 if (inode_has_buffers(inode))
418 return 0;
419 if (atomic_read(&inode->i_count))
420 return 0;
421 if (inode->i_data.nrpages)
422 return 0;
423 return 1;
427 * Scan `goal' inodes on the unused list for freeable ones. They are moved to
428 * a temporary list and then are freed outside inode_lock by dispose_list().
430 * Any inodes which are pinned purely because of attached pagecache have their
431 * pagecache removed. We expect the final iput() on that inode to add it to
432 * the front of the inode_unused list. So look for it there and if the
433 * inode is still freeable, proceed. The right inode is found 99.9% of the
434 * time in testing on a 4-way.
436 * If the inode has metadata buffers attached to mapping->private_list then
437 * try to remove them.
439 static void prune_icache(int nr_to_scan)
441 LIST_HEAD(freeable);
442 int nr_pruned = 0;
443 int nr_scanned;
444 unsigned long reap = 0;
446 mutex_lock(&iprune_mutex);
447 spin_lock(&inode_lock);
448 for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) {
449 struct inode *inode;
451 if (list_empty(&inode_unused))
452 break;
454 inode = list_entry(inode_unused.prev, struct inode, i_list);
456 if (inode->i_state || atomic_read(&inode->i_count)) {
457 list_move(&inode->i_list, &inode_unused);
458 continue;
460 if (inode_has_buffers(inode) || inode->i_data.nrpages) {
461 __iget(inode);
462 spin_unlock(&inode_lock);
463 if (remove_inode_buffers(inode))
464 reap += invalidate_mapping_pages(&inode->i_data,
465 0, -1);
466 iput(inode);
467 spin_lock(&inode_lock);
469 if (inode != list_entry(inode_unused.next,
470 struct inode, i_list))
471 continue; /* wrong inode or list_empty */
472 if (!can_unuse(inode))
473 continue;
475 list_move(&inode->i_list, &freeable);
476 WARN_ON(inode->i_state & I_NEW);
477 inode->i_state |= I_FREEING;
478 nr_pruned++;
480 inodes_stat.nr_unused -= nr_pruned;
481 if (current_is_kswapd())
482 __count_vm_events(KSWAPD_INODESTEAL, reap);
483 else
484 __count_vm_events(PGINODESTEAL, reap);
485 spin_unlock(&inode_lock);
487 dispose_list(&freeable);
488 mutex_unlock(&iprune_mutex);
492 * shrink_icache_memory() will attempt to reclaim some unused inodes. Here,
493 * "unused" means that no dentries are referring to the inodes: the files are
494 * not open and the dcache references to those inodes have already been
495 * reclaimed.
497 * This function is passed the number of inodes to scan, and it returns the
498 * total number of remaining possibly-reclaimable inodes.
500 static int shrink_icache_memory(int nr, gfp_t gfp_mask)
502 if (nr) {
504 * Nasty deadlock avoidance. We may hold various FS locks,
505 * and we don't want to recurse into the FS that called us
506 * in clear_inode() and friends..
508 if (!(gfp_mask & __GFP_FS))
509 return -1;
510 prune_icache(nr);
512 return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
515 static struct shrinker icache_shrinker = {
516 .shrink = shrink_icache_memory,
517 .seeks = DEFAULT_SEEKS,
520 static void __wait_on_freeing_inode(struct inode *inode);
522 * Called with the inode lock held.
523 * NOTE: we are not increasing the inode-refcount, you must call __iget()
524 * by hand after calling find_inode now! This simplifies iunique and won't
525 * add any additional branch in the common code.
527 static struct inode * find_inode(struct super_block * sb, struct hlist_head *head, int (*test)(struct inode *, void *), void *data)
529 struct hlist_node *node;
530 struct inode * inode = NULL;
532 repeat:
533 hlist_for_each_entry(inode, node, head, i_hash) {
534 if (inode->i_sb != sb)
535 continue;
536 if (!test(inode, data))
537 continue;
538 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
539 __wait_on_freeing_inode(inode);
540 goto repeat;
542 break;
544 return node ? inode : NULL;
548 * find_inode_fast is the fast path version of find_inode, see the comment at
549 * iget_locked for details.
551 static struct inode * find_inode_fast(struct super_block * sb, struct hlist_head *head, unsigned long ino)
553 struct hlist_node *node;
554 struct inode * inode = NULL;
556 repeat:
557 hlist_for_each_entry(inode, node, head, i_hash) {
558 if (inode->i_ino != ino)
559 continue;
560 if (inode->i_sb != sb)
561 continue;
562 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
563 __wait_on_freeing_inode(inode);
564 goto repeat;
566 break;
568 return node ? inode : NULL;
571 static unsigned long hash(struct super_block *sb, unsigned long hashval)
573 unsigned long tmp;
575 tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
576 L1_CACHE_BYTES;
577 tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS);
578 return tmp & I_HASHMASK;
581 static inline void
582 __inode_add_to_lists(struct super_block *sb, struct hlist_head *head,
583 struct inode *inode)
585 inodes_stat.nr_inodes++;
586 list_add(&inode->i_list, &inode_in_use);
587 list_add(&inode->i_sb_list, &sb->s_inodes);
588 if (head)
589 hlist_add_head(&inode->i_hash, head);
593 * inode_add_to_lists - add a new inode to relevant lists
594 * @sb: superblock inode belongs to
595 * @inode: inode to mark in use
597 * When an inode is allocated it needs to be accounted for, added to the in use
598 * list, the owning superblock and the inode hash. This needs to be done under
599 * the inode_lock, so export a function to do this rather than the inode lock
600 * itself. We calculate the hash list to add to here so it is all internal
601 * which requires the caller to have already set up the inode number in the
602 * inode to add.
604 void inode_add_to_lists(struct super_block *sb, struct inode *inode)
606 struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino);
608 spin_lock(&inode_lock);
609 __inode_add_to_lists(sb, head, inode);
610 spin_unlock(&inode_lock);
612 EXPORT_SYMBOL_GPL(inode_add_to_lists);
615 * new_inode - obtain an inode
616 * @sb: superblock
618 * Allocates a new inode for given superblock. The default gfp_mask
619 * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE.
620 * If HIGHMEM pages are unsuitable or it is known that pages allocated
621 * for the page cache are not reclaimable or migratable,
622 * mapping_set_gfp_mask() must be called with suitable flags on the
623 * newly created inode's mapping
626 struct inode *new_inode(struct super_block *sb)
629 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
630 * error if st_ino won't fit in target struct field. Use 32bit counter
631 * here to attempt to avoid that.
633 static unsigned int last_ino;
634 struct inode * inode;
636 spin_lock_prefetch(&inode_lock);
638 inode = alloc_inode(sb);
639 if (inode) {
640 spin_lock(&inode_lock);
641 __inode_add_to_lists(sb, NULL, inode);
642 inode->i_ino = ++last_ino;
643 inode->i_state = 0;
644 spin_unlock(&inode_lock);
646 return inode;
649 EXPORT_SYMBOL(new_inode);
651 void unlock_new_inode(struct inode *inode)
653 #ifdef CONFIG_DEBUG_LOCK_ALLOC
654 if (inode->i_mode & S_IFDIR) {
655 struct file_system_type *type = inode->i_sb->s_type;
658 * ensure nobody is actually holding i_mutex
660 mutex_destroy(&inode->i_mutex);
661 mutex_init(&inode->i_mutex);
662 lockdep_set_class(&inode->i_mutex, &type->i_mutex_dir_key);
664 #endif
666 * This is special! We do not need the spinlock
667 * when clearing I_LOCK, because we're guaranteed
668 * that nobody else tries to do anything about the
669 * state of the inode when it is locked, as we
670 * just created it (so there can be no old holders
671 * that haven't tested I_LOCK).
673 WARN_ON((inode->i_state & (I_LOCK|I_NEW)) != (I_LOCK|I_NEW));
674 inode->i_state &= ~(I_LOCK|I_NEW);
675 wake_up_inode(inode);
678 EXPORT_SYMBOL(unlock_new_inode);
681 * This is called without the inode lock held.. Be careful.
683 * We no longer cache the sb_flags in i_flags - see fs.h
684 * -- rmk@arm.uk.linux.org
686 static struct inode * get_new_inode(struct super_block *sb, struct hlist_head *head, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *data)
688 struct inode * inode;
690 inode = alloc_inode(sb);
691 if (inode) {
692 struct inode * old;
694 spin_lock(&inode_lock);
695 /* We released the lock, so.. */
696 old = find_inode(sb, head, test, data);
697 if (!old) {
698 if (set(inode, data))
699 goto set_failed;
701 __inode_add_to_lists(sb, head, inode);
702 inode->i_state = I_LOCK|I_NEW;
703 spin_unlock(&inode_lock);
705 /* Return the locked inode with I_NEW set, the
706 * caller is responsible for filling in the contents
708 return inode;
712 * Uhhuh, somebody else created the same inode under
713 * us. Use the old inode instead of the one we just
714 * allocated.
716 __iget(old);
717 spin_unlock(&inode_lock);
718 destroy_inode(inode);
719 inode = old;
720 wait_on_inode(inode);
722 return inode;
724 set_failed:
725 spin_unlock(&inode_lock);
726 destroy_inode(inode);
727 return NULL;
731 * get_new_inode_fast is the fast path version of get_new_inode, see the
732 * comment at iget_locked for details.
734 static struct inode * get_new_inode_fast(struct super_block *sb, struct hlist_head *head, unsigned long ino)
736 struct inode * inode;
738 inode = alloc_inode(sb);
739 if (inode) {
740 struct inode * old;
742 spin_lock(&inode_lock);
743 /* We released the lock, so.. */
744 old = find_inode_fast(sb, head, ino);
745 if (!old) {
746 inode->i_ino = ino;
747 __inode_add_to_lists(sb, head, inode);
748 inode->i_state = I_LOCK|I_NEW;
749 spin_unlock(&inode_lock);
751 /* Return the locked inode with I_NEW set, the
752 * caller is responsible for filling in the contents
754 return inode;
758 * Uhhuh, somebody else created the same inode under
759 * us. Use the old inode instead of the one we just
760 * allocated.
762 __iget(old);
763 spin_unlock(&inode_lock);
764 destroy_inode(inode);
765 inode = old;
766 wait_on_inode(inode);
768 return inode;
772 * iunique - get a unique inode number
773 * @sb: superblock
774 * @max_reserved: highest reserved inode number
776 * Obtain an inode number that is unique on the system for a given
777 * superblock. This is used by file systems that have no natural
778 * permanent inode numbering system. An inode number is returned that
779 * is higher than the reserved limit but unique.
781 * BUGS:
782 * With a large number of inodes live on the file system this function
783 * currently becomes quite slow.
785 ino_t iunique(struct super_block *sb, ino_t max_reserved)
788 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
789 * error if st_ino won't fit in target struct field. Use 32bit counter
790 * here to attempt to avoid that.
792 static unsigned int counter;
793 struct inode *inode;
794 struct hlist_head *head;
795 ino_t res;
797 spin_lock(&inode_lock);
798 do {
799 if (counter <= max_reserved)
800 counter = max_reserved + 1;
801 res = counter++;
802 head = inode_hashtable + hash(sb, res);
803 inode = find_inode_fast(sb, head, res);
804 } while (inode != NULL);
805 spin_unlock(&inode_lock);
807 return res;
809 EXPORT_SYMBOL(iunique);
811 struct inode *igrab(struct inode *inode)
813 spin_lock(&inode_lock);
814 if (!(inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)))
815 __iget(inode);
816 else
818 * Handle the case where s_op->clear_inode is not been
819 * called yet, and somebody is calling igrab
820 * while the inode is getting freed.
822 inode = NULL;
823 spin_unlock(&inode_lock);
824 return inode;
827 EXPORT_SYMBOL(igrab);
830 * ifind - internal function, you want ilookup5() or iget5().
831 * @sb: super block of file system to search
832 * @head: the head of the list to search
833 * @test: callback used for comparisons between inodes
834 * @data: opaque data pointer to pass to @test
835 * @wait: if true wait for the inode to be unlocked, if false do not
837 * ifind() searches for the inode specified by @data in the inode
838 * cache. This is a generalized version of ifind_fast() for file systems where
839 * the inode number is not sufficient for unique identification of an inode.
841 * If the inode is in the cache, the inode is returned with an incremented
842 * reference count.
844 * Otherwise NULL is returned.
846 * Note, @test is called with the inode_lock held, so can't sleep.
848 static struct inode *ifind(struct super_block *sb,
849 struct hlist_head *head, int (*test)(struct inode *, void *),
850 void *data, const int wait)
852 struct inode *inode;
854 spin_lock(&inode_lock);
855 inode = find_inode(sb, head, test, data);
856 if (inode) {
857 __iget(inode);
858 spin_unlock(&inode_lock);
859 if (likely(wait))
860 wait_on_inode(inode);
861 return inode;
863 spin_unlock(&inode_lock);
864 return NULL;
868 * ifind_fast - internal function, you want ilookup() or iget().
869 * @sb: super block of file system to search
870 * @head: head of the list to search
871 * @ino: inode number to search for
873 * ifind_fast() searches for the inode @ino in the inode cache. This is for
874 * file systems where the inode number is sufficient for unique identification
875 * of an inode.
877 * If the inode is in the cache, the inode is returned with an incremented
878 * reference count.
880 * Otherwise NULL is returned.
882 static struct inode *ifind_fast(struct super_block *sb,
883 struct hlist_head *head, unsigned long ino)
885 struct inode *inode;
887 spin_lock(&inode_lock);
888 inode = find_inode_fast(sb, head, ino);
889 if (inode) {
890 __iget(inode);
891 spin_unlock(&inode_lock);
892 wait_on_inode(inode);
893 return inode;
895 spin_unlock(&inode_lock);
896 return NULL;
900 * ilookup5_nowait - search for an inode in the inode cache
901 * @sb: super block of file system to search
902 * @hashval: hash value (usually inode number) to search for
903 * @test: callback used for comparisons between inodes
904 * @data: opaque data pointer to pass to @test
906 * ilookup5() uses ifind() to search for the inode specified by @hashval and
907 * @data in the inode cache. This is a generalized version of ilookup() for
908 * file systems where the inode number is not sufficient for unique
909 * identification of an inode.
911 * If the inode is in the cache, the inode is returned with an incremented
912 * reference count. Note, the inode lock is not waited upon so you have to be
913 * very careful what you do with the returned inode. You probably should be
914 * using ilookup5() instead.
916 * Otherwise NULL is returned.
918 * Note, @test is called with the inode_lock held, so can't sleep.
920 struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval,
921 int (*test)(struct inode *, void *), void *data)
923 struct hlist_head *head = inode_hashtable + hash(sb, hashval);
925 return ifind(sb, head, test, data, 0);
928 EXPORT_SYMBOL(ilookup5_nowait);
931 * ilookup5 - search for an inode in the inode cache
932 * @sb: super block of file system to search
933 * @hashval: hash value (usually inode number) to search for
934 * @test: callback used for comparisons between inodes
935 * @data: opaque data pointer to pass to @test
937 * ilookup5() uses ifind() to search for the inode specified by @hashval and
938 * @data in the inode cache. This is a generalized version of ilookup() for
939 * file systems where the inode number is not sufficient for unique
940 * identification of an inode.
942 * If the inode is in the cache, the inode lock is waited upon and the inode is
943 * returned with an incremented reference count.
945 * Otherwise NULL is returned.
947 * Note, @test is called with the inode_lock held, so can't sleep.
949 struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
950 int (*test)(struct inode *, void *), void *data)
952 struct hlist_head *head = inode_hashtable + hash(sb, hashval);
954 return ifind(sb, head, test, data, 1);
957 EXPORT_SYMBOL(ilookup5);
960 * ilookup - search for an inode in the inode cache
961 * @sb: super block of file system to search
962 * @ino: inode number to search for
964 * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache.
965 * This is for file systems where the inode number is sufficient for unique
966 * identification of an inode.
968 * If the inode is in the cache, the inode is returned with an incremented
969 * reference count.
971 * Otherwise NULL is returned.
973 struct inode *ilookup(struct super_block *sb, unsigned long ino)
975 struct hlist_head *head = inode_hashtable + hash(sb, ino);
977 return ifind_fast(sb, head, ino);
980 EXPORT_SYMBOL(ilookup);
983 * iget5_locked - obtain an inode from a mounted file system
984 * @sb: super block of file system
985 * @hashval: hash value (usually inode number) to get
986 * @test: callback used for comparisons between inodes
987 * @set: callback used to initialize a new struct inode
988 * @data: opaque data pointer to pass to @test and @set
990 * iget5_locked() uses ifind() to search for the inode specified by @hashval
991 * and @data in the inode cache and if present it is returned with an increased
992 * reference count. This is a generalized version of iget_locked() for file
993 * systems where the inode number is not sufficient for unique identification
994 * of an inode.
996 * If the inode is not in cache, get_new_inode() is called to allocate a new
997 * inode and this is returned locked, hashed, and with the I_NEW flag set. The
998 * file system gets to fill it in before unlocking it via unlock_new_inode().
1000 * Note both @test and @set are called with the inode_lock held, so can't sleep.
1002 struct inode *iget5_locked(struct super_block *sb, unsigned long hashval,
1003 int (*test)(struct inode *, void *),
1004 int (*set)(struct inode *, void *), void *data)
1006 struct hlist_head *head = inode_hashtable + hash(sb, hashval);
1007 struct inode *inode;
1009 inode = ifind(sb, head, test, data, 1);
1010 if (inode)
1011 return inode;
1013 * get_new_inode() will do the right thing, re-trying the search
1014 * in case it had to block at any point.
1016 return get_new_inode(sb, head, test, set, data);
1019 EXPORT_SYMBOL(iget5_locked);
1022 * iget_locked - obtain an inode from a mounted file system
1023 * @sb: super block of file system
1024 * @ino: inode number to get
1026 * iget_locked() uses ifind_fast() to search for the inode specified by @ino in
1027 * the inode cache and if present it is returned with an increased reference
1028 * count. This is for file systems where the inode number is sufficient for
1029 * unique identification of an inode.
1031 * If the inode is not in cache, get_new_inode_fast() is called to allocate a
1032 * new inode and this is returned locked, hashed, and with the I_NEW flag set.
1033 * The file system gets to fill it in before unlocking it via
1034 * unlock_new_inode().
1036 struct inode *iget_locked(struct super_block *sb, unsigned long ino)
1038 struct hlist_head *head = inode_hashtable + hash(sb, ino);
1039 struct inode *inode;
1041 inode = ifind_fast(sb, head, ino);
1042 if (inode)
1043 return inode;
1045 * get_new_inode_fast() will do the right thing, re-trying the search
1046 * in case it had to block at any point.
1048 return get_new_inode_fast(sb, head, ino);
1051 EXPORT_SYMBOL(iget_locked);
1053 int insert_inode_locked(struct inode *inode)
1055 struct super_block *sb = inode->i_sb;
1056 ino_t ino = inode->i_ino;
1057 struct hlist_head *head = inode_hashtable + hash(sb, ino);
1058 struct inode *old;
1060 inode->i_state |= I_LOCK|I_NEW;
1061 while (1) {
1062 spin_lock(&inode_lock);
1063 old = find_inode_fast(sb, head, ino);
1064 if (likely(!old)) {
1065 hlist_add_head(&inode->i_hash, head);
1066 spin_unlock(&inode_lock);
1067 return 0;
1069 __iget(old);
1070 spin_unlock(&inode_lock);
1071 wait_on_inode(old);
1072 if (unlikely(!hlist_unhashed(&old->i_hash))) {
1073 iput(old);
1074 return -EBUSY;
1076 iput(old);
1080 EXPORT_SYMBOL(insert_inode_locked);
1082 int insert_inode_locked4(struct inode *inode, unsigned long hashval,
1083 int (*test)(struct inode *, void *), void *data)
1085 struct super_block *sb = inode->i_sb;
1086 struct hlist_head *head = inode_hashtable + hash(sb, hashval);
1087 struct inode *old;
1089 inode->i_state |= I_LOCK|I_NEW;
1091 while (1) {
1092 spin_lock(&inode_lock);
1093 old = find_inode(sb, head, test, data);
1094 if (likely(!old)) {
1095 hlist_add_head(&inode->i_hash, head);
1096 spin_unlock(&inode_lock);
1097 return 0;
1099 __iget(old);
1100 spin_unlock(&inode_lock);
1101 wait_on_inode(old);
1102 if (unlikely(!hlist_unhashed(&old->i_hash))) {
1103 iput(old);
1104 return -EBUSY;
1106 iput(old);
1110 EXPORT_SYMBOL(insert_inode_locked4);
1113 * __insert_inode_hash - hash an inode
1114 * @inode: unhashed inode
1115 * @hashval: unsigned long value used to locate this object in the
1116 * inode_hashtable.
1118 * Add an inode to the inode hash for this superblock.
1120 void __insert_inode_hash(struct inode *inode, unsigned long hashval)
1122 struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval);
1123 spin_lock(&inode_lock);
1124 hlist_add_head(&inode->i_hash, head);
1125 spin_unlock(&inode_lock);
1128 EXPORT_SYMBOL(__insert_inode_hash);
1131 * remove_inode_hash - remove an inode from the hash
1132 * @inode: inode to unhash
1134 * Remove an inode from the superblock.
1136 void remove_inode_hash(struct inode *inode)
1138 spin_lock(&inode_lock);
1139 hlist_del_init(&inode->i_hash);
1140 spin_unlock(&inode_lock);
1143 EXPORT_SYMBOL(remove_inode_hash);
1146 * Tell the filesystem that this inode is no longer of any interest and should
1147 * be completely destroyed.
1149 * We leave the inode in the inode hash table until *after* the filesystem's
1150 * ->delete_inode completes. This ensures that an iget (such as nfsd might
1151 * instigate) will always find up-to-date information either in the hash or on
1152 * disk.
1154 * I_FREEING is set so that no-one will take a new reference to the inode while
1155 * it is being deleted.
1157 void generic_delete_inode(struct inode *inode)
1159 const struct super_operations *op = inode->i_sb->s_op;
1161 list_del_init(&inode->i_list);
1162 list_del_init(&inode->i_sb_list);
1163 WARN_ON(inode->i_state & I_NEW);
1164 inode->i_state |= I_FREEING;
1165 inodes_stat.nr_inodes--;
1166 spin_unlock(&inode_lock);
1168 security_inode_delete(inode);
1170 if (op->delete_inode) {
1171 void (*delete)(struct inode *) = op->delete_inode;
1172 if (!is_bad_inode(inode))
1173 vfs_dq_init(inode);
1174 /* Filesystems implementing their own
1175 * s_op->delete_inode are required to call
1176 * truncate_inode_pages and clear_inode()
1177 * internally */
1178 delete(inode);
1179 } else {
1180 truncate_inode_pages(&inode->i_data, 0);
1181 clear_inode(inode);
1183 spin_lock(&inode_lock);
1184 hlist_del_init(&inode->i_hash);
1185 spin_unlock(&inode_lock);
1186 wake_up_inode(inode);
1187 BUG_ON(inode->i_state != I_CLEAR);
1188 destroy_inode(inode);
1191 EXPORT_SYMBOL(generic_delete_inode);
1193 static void generic_forget_inode(struct inode *inode)
1195 struct super_block *sb = inode->i_sb;
1197 if (!hlist_unhashed(&inode->i_hash)) {
1198 if (!(inode->i_state & (I_DIRTY|I_SYNC)))
1199 list_move(&inode->i_list, &inode_unused);
1200 inodes_stat.nr_unused++;
1201 if (sb->s_flags & MS_ACTIVE) {
1202 spin_unlock(&inode_lock);
1203 return;
1205 WARN_ON(inode->i_state & I_NEW);
1206 inode->i_state |= I_WILL_FREE;
1207 spin_unlock(&inode_lock);
1208 write_inode_now(inode, 1);
1209 spin_lock(&inode_lock);
1210 WARN_ON(inode->i_state & I_NEW);
1211 inode->i_state &= ~I_WILL_FREE;
1212 inodes_stat.nr_unused--;
1213 hlist_del_init(&inode->i_hash);
1215 list_del_init(&inode->i_list);
1216 list_del_init(&inode->i_sb_list);
1217 WARN_ON(inode->i_state & I_NEW);
1218 inode->i_state |= I_FREEING;
1219 inodes_stat.nr_inodes--;
1220 spin_unlock(&inode_lock);
1221 if (inode->i_data.nrpages)
1222 truncate_inode_pages(&inode->i_data, 0);
1223 clear_inode(inode);
1224 wake_up_inode(inode);
1225 destroy_inode(inode);
1229 * Normal UNIX filesystem behaviour: delete the
1230 * inode when the usage count drops to zero, and
1231 * i_nlink is zero.
1233 void generic_drop_inode(struct inode *inode)
1235 if (!inode->i_nlink)
1236 generic_delete_inode(inode);
1237 else
1238 generic_forget_inode(inode);
1241 EXPORT_SYMBOL_GPL(generic_drop_inode);
1244 * Called when we're dropping the last reference
1245 * to an inode.
1247 * Call the FS "drop()" function, defaulting to
1248 * the legacy UNIX filesystem behaviour..
1250 * NOTE! NOTE! NOTE! We're called with the inode lock
1251 * held, and the drop function is supposed to release
1252 * the lock!
1254 static inline void iput_final(struct inode *inode)
1256 const struct super_operations *op = inode->i_sb->s_op;
1257 void (*drop)(struct inode *) = generic_drop_inode;
1259 if (op && op->drop_inode)
1260 drop = op->drop_inode;
1261 drop(inode);
1265 * iput - put an inode
1266 * @inode: inode to put
1268 * Puts an inode, dropping its usage count. If the inode use count hits
1269 * zero, the inode is then freed and may also be destroyed.
1271 * Consequently, iput() can sleep.
1273 void iput(struct inode *inode)
1275 if (inode) {
1276 BUG_ON(inode->i_state == I_CLEAR);
1278 if (atomic_dec_and_lock(&inode->i_count, &inode_lock))
1279 iput_final(inode);
1283 EXPORT_SYMBOL(iput);
1286 * bmap - find a block number in a file
1287 * @inode: inode of file
1288 * @block: block to find
1290 * Returns the block number on the device holding the inode that
1291 * is the disk block number for the block of the file requested.
1292 * That is, asked for block 4 of inode 1 the function will return the
1293 * disk block relative to the disk start that holds that block of the
1294 * file.
1296 sector_t bmap(struct inode * inode, sector_t block)
1298 sector_t res = 0;
1299 if (inode->i_mapping->a_ops->bmap)
1300 res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block);
1301 return res;
1303 EXPORT_SYMBOL(bmap);
1306 * With relative atime, only update atime if the previous atime is
1307 * earlier than either the ctime or mtime or if at least a day has
1308 * passed since the last atime update.
1310 static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
1311 struct timespec now)
1314 if (!(mnt->mnt_flags & MNT_RELATIME))
1315 return 1;
1317 * Is mtime younger than atime? If yes, update atime:
1319 if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0)
1320 return 1;
1322 * Is ctime younger than atime? If yes, update atime:
1324 if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0)
1325 return 1;
1328 * Is the previous atime value older than a day? If yes,
1329 * update atime:
1331 if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60)
1332 return 1;
1334 * Good, we can skip the atime update:
1336 return 0;
1340 * touch_atime - update the access time
1341 * @mnt: mount the inode is accessed on
1342 * @dentry: dentry accessed
1344 * Update the accessed time on an inode and mark it for writeback.
1345 * This function automatically handles read only file systems and media,
1346 * as well as the "noatime" flag and inode specific "noatime" markers.
1348 void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
1350 struct inode *inode = dentry->d_inode;
1351 struct timespec now;
1353 if (mnt_want_write(mnt))
1354 return;
1355 if (inode->i_flags & S_NOATIME)
1356 goto out;
1357 if (IS_NOATIME(inode))
1358 goto out;
1359 if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))
1360 goto out;
1362 if (mnt->mnt_flags & MNT_NOATIME)
1363 goto out;
1364 if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
1365 goto out;
1367 now = current_fs_time(inode->i_sb);
1369 if (!relatime_need_update(mnt, inode, now))
1370 goto out;
1372 if (timespec_equal(&inode->i_atime, &now))
1373 goto out;
1375 inode->i_atime = now;
1376 mark_inode_dirty_sync(inode);
1377 out:
1378 mnt_drop_write(mnt);
1380 EXPORT_SYMBOL(touch_atime);
1383 * file_update_time - update mtime and ctime time
1384 * @file: file accessed
1386 * Update the mtime and ctime members of an inode and mark the inode
1387 * for writeback. Note that this function is meant exclusively for
1388 * usage in the file write path of filesystems, and filesystems may
1389 * choose to explicitly ignore update via this function with the
1390 * S_NOCTIME inode flag, e.g. for network filesystem where these
1391 * timestamps are handled by the server.
1394 void file_update_time(struct file *file)
1396 struct inode *inode = file->f_path.dentry->d_inode;
1397 struct timespec now;
1398 int sync_it = 0;
1399 int err;
1401 if (IS_NOCMTIME(inode))
1402 return;
1404 err = mnt_want_write(file->f_path.mnt);
1405 if (err)
1406 return;
1408 now = current_fs_time(inode->i_sb);
1409 if (!timespec_equal(&inode->i_mtime, &now)) {
1410 inode->i_mtime = now;
1411 sync_it = 1;
1414 if (!timespec_equal(&inode->i_ctime, &now)) {
1415 inode->i_ctime = now;
1416 sync_it = 1;
1419 if (IS_I_VERSION(inode)) {
1420 inode_inc_iversion(inode);
1421 sync_it = 1;
1424 if (sync_it)
1425 mark_inode_dirty_sync(inode);
1426 mnt_drop_write(file->f_path.mnt);
1429 EXPORT_SYMBOL(file_update_time);
1431 int inode_needs_sync(struct inode *inode)
1433 if (IS_SYNC(inode))
1434 return 1;
1435 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
1436 return 1;
1437 return 0;
1440 EXPORT_SYMBOL(inode_needs_sync);
1442 int inode_wait(void *word)
1444 schedule();
1445 return 0;
1447 EXPORT_SYMBOL(inode_wait);
1450 * If we try to find an inode in the inode hash while it is being
1451 * deleted, we have to wait until the filesystem completes its
1452 * deletion before reporting that it isn't found. This function waits
1453 * until the deletion _might_ have completed. Callers are responsible
1454 * to recheck inode state.
1456 * It doesn't matter if I_LOCK is not set initially, a call to
1457 * wake_up_inode() after removing from the hash list will DTRT.
1459 * This is called with inode_lock held.
1461 static void __wait_on_freeing_inode(struct inode *inode)
1463 wait_queue_head_t *wq;
1464 DEFINE_WAIT_BIT(wait, &inode->i_state, __I_LOCK);
1465 wq = bit_waitqueue(&inode->i_state, __I_LOCK);
1466 prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
1467 spin_unlock(&inode_lock);
1468 schedule();
1469 finish_wait(wq, &wait.wait);
1470 spin_lock(&inode_lock);
1474 * We rarely want to lock two inodes that do not have a parent/child
1475 * relationship (such as directory, child inode) simultaneously. The
1476 * vast majority of file systems should be able to get along fine
1477 * without this. Do not use these functions except as a last resort.
1479 void inode_double_lock(struct inode *inode1, struct inode *inode2)
1481 if (inode1 == NULL || inode2 == NULL || inode1 == inode2) {
1482 if (inode1)
1483 mutex_lock(&inode1->i_mutex);
1484 else if (inode2)
1485 mutex_lock(&inode2->i_mutex);
1486 return;
1489 if (inode1 < inode2) {
1490 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
1491 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
1492 } else {
1493 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT);
1494 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD);
1497 EXPORT_SYMBOL(inode_double_lock);
1499 void inode_double_unlock(struct inode *inode1, struct inode *inode2)
1501 if (inode1)
1502 mutex_unlock(&inode1->i_mutex);
1504 if (inode2 && inode2 != inode1)
1505 mutex_unlock(&inode2->i_mutex);
1507 EXPORT_SYMBOL(inode_double_unlock);
1509 static __initdata unsigned long ihash_entries;
1510 static int __init set_ihash_entries(char *str)
1512 if (!str)
1513 return 0;
1514 ihash_entries = simple_strtoul(str, &str, 0);
1515 return 1;
1517 __setup("ihash_entries=", set_ihash_entries);
1520 * Initialize the waitqueues and inode hash table.
1522 void __init inode_init_early(void)
1524 int loop;
1526 /* If hashes are distributed across NUMA nodes, defer
1527 * hash allocation until vmalloc space is available.
1529 if (hashdist)
1530 return;
1532 inode_hashtable =
1533 alloc_large_system_hash("Inode-cache",
1534 sizeof(struct hlist_head),
1535 ihash_entries,
1537 HASH_EARLY,
1538 &i_hash_shift,
1539 &i_hash_mask,
1542 for (loop = 0; loop < (1 << i_hash_shift); loop++)
1543 INIT_HLIST_HEAD(&inode_hashtable[loop]);
1546 void __init inode_init(void)
1548 int loop;
1550 /* inode slab cache */
1551 inode_cachep = kmem_cache_create("inode_cache",
1552 sizeof(struct inode),
1554 (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
1555 SLAB_MEM_SPREAD),
1556 init_once);
1557 register_shrinker(&icache_shrinker);
1559 /* Hash may have been set up in inode_init_early */
1560 if (!hashdist)
1561 return;
1563 inode_hashtable =
1564 alloc_large_system_hash("Inode-cache",
1565 sizeof(struct hlist_head),
1566 ihash_entries,
1569 &i_hash_shift,
1570 &i_hash_mask,
1573 for (loop = 0; loop < (1 << i_hash_shift); loop++)
1574 INIT_HLIST_HEAD(&inode_hashtable[loop]);
1577 void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev)
1579 inode->i_mode = mode;
1580 if (S_ISCHR(mode)) {
1581 inode->i_fop = &def_chr_fops;
1582 inode->i_rdev = rdev;
1583 } else if (S_ISBLK(mode)) {
1584 inode->i_fop = &def_blk_fops;
1585 inode->i_rdev = rdev;
1586 } else if (S_ISFIFO(mode))
1587 inode->i_fop = &def_fifo_fops;
1588 else if (S_ISSOCK(mode))
1589 inode->i_fop = &bad_sock_fops;
1590 else
1591 printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o)\n",
1592 mode);
1594 EXPORT_SYMBOL(init_special_inode);