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1 | /* |
2 | * (C) 1997 Linus Torvalds |
3 | * (C) 1999 Andrea Arcangeli <andrea@suse.de> (dynamic inode allocation) |
4 | */ |
5 | #include <linux/export.h> |
6 | #include <linux/fs.h> |
7 | #include <linux/mm.h> |
8 | #include <linux/backing-dev.h> |
9 | #include <linux/hash.h> |
10 | #include <linux/swap.h> |
11 | #include <linux/security.h> |
12 | #include <linux/cdev.h> |
13 | #include <linux/bootmem.h> |
14 | #include <linux/fsnotify.h> |
15 | #include <linux/mount.h> |
16 | #include <linux/posix_acl.h> |
17 | #include <linux/prefetch.h> |
18 | #include <linux/buffer_head.h> /* for inode_has_buffers */ |
19 | #include <linux/ratelimit.h> |
20 | #include <linux/list_lru.h> |
21 | #include "internal.h" |
22 | |
23 | /* |
24 | * Inode locking rules: |
25 | * |
26 | * inode->i_lock protects: |
27 | * inode->i_state, inode->i_hash, __iget() |
28 | * Inode LRU list locks protect: |
29 | * inode->i_sb->s_inode_lru, inode->i_lru |
30 | * inode_sb_list_lock protects: |
31 | * sb->s_inodes, inode->i_sb_list |
32 | * bdi->wb.list_lock protects: |
33 | * bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list |
34 | * inode_hash_lock protects: |
35 | * inode_hashtable, inode->i_hash |
36 | * |
37 | * Lock ordering: |
38 | * |
39 | * inode_sb_list_lock |
40 | * inode->i_lock |
41 | * Inode LRU list locks |
42 | * |
43 | * bdi->wb.list_lock |
44 | * inode->i_lock |
45 | * |
46 | * inode_hash_lock |
47 | * inode_sb_list_lock |
48 | * inode->i_lock |
49 | * |
50 | * iunique_lock |
51 | * inode_hash_lock |
52 | */ |
53 | |
54 | static unsigned int i_hash_mask __read_mostly; |
55 | static unsigned int i_hash_shift __read_mostly; |
56 | static struct hlist_head *inode_hashtable __read_mostly; |
57 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock); |
58 | |
59 | __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock); |
60 | |
61 | /* |
62 | * Empty aops. Can be used for the cases where the user does not |
63 | * define any of the address_space operations. |
64 | */ |
65 | const struct address_space_operations empty_aops = { |
66 | }; |
67 | EXPORT_SYMBOL(empty_aops); |
68 | |
69 | /* |
70 | * Statistics gathering.. |
71 | */ |
72 | struct inodes_stat_t inodes_stat; |
73 | |
74 | static DEFINE_PER_CPU(unsigned long, nr_inodes); |
75 | static DEFINE_PER_CPU(unsigned long, nr_unused); |
76 | |
77 | static struct kmem_cache *inode_cachep __read_mostly; |
78 | |
79 | static long get_nr_inodes(void) |
80 | { |
81 | int i; |
82 | long sum = 0; |
83 | for_each_possible_cpu(i) |
84 | sum += per_cpu(nr_inodes, i); |
85 | return sum < 0 ? 0 : sum; |
86 | } |
87 | |
88 | static inline long get_nr_inodes_unused(void) |
89 | { |
90 | int i; |
91 | long sum = 0; |
92 | for_each_possible_cpu(i) |
93 | sum += per_cpu(nr_unused, i); |
94 | return sum < 0 ? 0 : sum; |
95 | } |
96 | |
97 | long get_nr_dirty_inodes(void) |
98 | { |
99 | /* not actually dirty inodes, but a wild approximation */ |
100 | long nr_dirty = get_nr_inodes() - get_nr_inodes_unused(); |
101 | return nr_dirty > 0 ? nr_dirty : 0; |
102 | } |
103 | |
104 | /* |
105 | * Handle nr_inode sysctl |
106 | */ |
107 | #ifdef CONFIG_SYSCTL |
108 | int proc_nr_inodes(ctl_table *table, int write, |
109 | void __user *buffer, size_t *lenp, loff_t *ppos) |
110 | { |
111 | inodes_stat.nr_inodes = get_nr_inodes(); |
112 | inodes_stat.nr_unused = get_nr_inodes_unused(); |
113 | return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); |
114 | } |
115 | #endif |
116 | |
117 | /** |
118 | * inode_init_always - perform inode structure intialisation |
119 | * @sb: superblock inode belongs to |
120 | * @inode: inode to initialise |
121 | * |
122 | * These are initializations that need to be done on every inode |
123 | * allocation as the fields are not initialised by slab allocation. |
124 | */ |
125 | int inode_init_always(struct super_block *sb, struct inode *inode) |
126 | { |
127 | static const struct inode_operations empty_iops; |
128 | static const struct file_operations empty_fops; |
129 | struct address_space *const mapping = &inode->i_data; |
130 | |
131 | inode->i_sb = sb; |
132 | inode->i_blkbits = sb->s_blocksize_bits; |
133 | inode->i_flags = 0; |
134 | atomic_set(&inode->i_count, 1); |
135 | inode->i_op = &empty_iops; |
136 | inode->i_fop = &empty_fops; |
137 | inode->__i_nlink = 1; |
138 | inode->i_opflags = 0; |
139 | i_uid_write(inode, 0); |
140 | i_gid_write(inode, 0); |
141 | atomic_set(&inode->i_writecount, 0); |
142 | inode->i_size = 0; |
143 | inode->i_blocks = 0; |
144 | inode->i_bytes = 0; |
145 | inode->i_generation = 0; |
146 | #ifdef CONFIG_QUOTA |
147 | memset(&inode->i_dquot, 0, sizeof(inode->i_dquot)); |
148 | #endif |
149 | inode->i_pipe = NULL; |
150 | inode->i_bdev = NULL; |
151 | inode->i_cdev = NULL; |
152 | inode->i_rdev = 0; |
153 | inode->dirtied_when = 0; |
154 | |
155 | if (security_inode_alloc(inode)) |
156 | goto out; |
157 | spin_lock_init(&inode->i_lock); |
158 | lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key); |
159 | |
160 | mutex_init(&inode->i_mutex); |
161 | lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key); |
162 | |
163 | atomic_set(&inode->i_dio_count, 0); |
164 | |
165 | mapping->a_ops = &empty_aops; |
166 | mapping->host = inode; |
167 | mapping->flags = 0; |
168 | mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE); |
169 | mapping->private_data = NULL; |
170 | mapping->backing_dev_info = &default_backing_dev_info; |
171 | mapping->writeback_index = 0; |
172 | |
173 | /* |
174 | * If the block_device provides a backing_dev_info for client |
175 | * inodes then use that. Otherwise the inode share the bdev's |
176 | * backing_dev_info. |
177 | */ |
178 | if (sb->s_bdev) { |
179 | struct backing_dev_info *bdi; |
180 | |
181 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; |
182 | mapping->backing_dev_info = bdi; |
183 | } |
184 | inode->i_private = NULL; |
185 | inode->i_mapping = mapping; |
186 | INIT_HLIST_HEAD(&inode->i_dentry); /* buggered by rcu freeing */ |
187 | #ifdef CONFIG_FS_POSIX_ACL |
188 | inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; |
189 | #endif |
190 | |
191 | #ifdef CONFIG_FSNOTIFY |
192 | inode->i_fsnotify_mask = 0; |
193 | #endif |
194 | |
195 | this_cpu_inc(nr_inodes); |
196 | |
197 | return 0; |
198 | out: |
199 | return -ENOMEM; |
200 | } |
201 | EXPORT_SYMBOL(inode_init_always); |
202 | |
203 | static struct inode *alloc_inode(struct super_block *sb) |
204 | { |
205 | struct inode *inode; |
206 | |
207 | if (sb->s_op->alloc_inode) |
208 | inode = sb->s_op->alloc_inode(sb); |
209 | else |
210 | inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL); |
211 | |
212 | if (!inode) |
213 | return NULL; |
214 | |
215 | if (unlikely(inode_init_always(sb, inode))) { |
216 | if (inode->i_sb->s_op->destroy_inode) |
217 | inode->i_sb->s_op->destroy_inode(inode); |
218 | else |
219 | kmem_cache_free(inode_cachep, inode); |
220 | return NULL; |
221 | } |
222 | |
223 | return inode; |
224 | } |
225 | |
226 | void free_inode_nonrcu(struct inode *inode) |
227 | { |
228 | kmem_cache_free(inode_cachep, inode); |
229 | } |
230 | EXPORT_SYMBOL(free_inode_nonrcu); |
231 | |
232 | void __destroy_inode(struct inode *inode) |
233 | { |
234 | BUG_ON(inode_has_buffers(inode)); |
235 | security_inode_free(inode); |
236 | fsnotify_inode_delete(inode); |
237 | if (!inode->i_nlink) { |
238 | WARN_ON(atomic_long_read(&inode->i_sb->s_remove_count) == 0); |
239 | atomic_long_dec(&inode->i_sb->s_remove_count); |
240 | } |
241 | |
242 | #ifdef CONFIG_FS_POSIX_ACL |
243 | if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED) |
244 | posix_acl_release(inode->i_acl); |
245 | if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) |
246 | posix_acl_release(inode->i_default_acl); |
247 | #endif |
248 | this_cpu_dec(nr_inodes); |
249 | } |
250 | EXPORT_SYMBOL(__destroy_inode); |
251 | |
252 | static void i_callback(struct rcu_head *head) |
253 | { |
254 | struct inode *inode = container_of(head, struct inode, i_rcu); |
255 | kmem_cache_free(inode_cachep, inode); |
256 | } |
257 | |
258 | static void destroy_inode(struct inode *inode) |
259 | { |
260 | BUG_ON(!list_empty(&inode->i_lru)); |
261 | __destroy_inode(inode); |
262 | if (inode->i_sb->s_op->destroy_inode) |
263 | inode->i_sb->s_op->destroy_inode(inode); |
264 | else |
265 | call_rcu(&inode->i_rcu, i_callback); |
266 | } |
267 | |
268 | /** |
269 | * drop_nlink - directly drop an inode's link count |
270 | * @inode: inode |
271 | * |
272 | * This is a low-level filesystem helper to replace any |
273 | * direct filesystem manipulation of i_nlink. In cases |
274 | * where we are attempting to track writes to the |
275 | * filesystem, a decrement to zero means an imminent |
276 | * write when the file is truncated and actually unlinked |
277 | * on the filesystem. |
278 | */ |
279 | void drop_nlink(struct inode *inode) |
280 | { |
281 | WARN_ON(inode->i_nlink == 0); |
282 | inode->__i_nlink--; |
283 | if (!inode->i_nlink) |
284 | atomic_long_inc(&inode->i_sb->s_remove_count); |
285 | } |
286 | EXPORT_SYMBOL(drop_nlink); |
287 | |
288 | /** |
289 | * clear_nlink - directly zero an inode's link count |
290 | * @inode: inode |
291 | * |
292 | * This is a low-level filesystem helper to replace any |
293 | * direct filesystem manipulation of i_nlink. See |
294 | * drop_nlink() for why we care about i_nlink hitting zero. |
295 | */ |
296 | void clear_nlink(struct inode *inode) |
297 | { |
298 | if (inode->i_nlink) { |
299 | inode->__i_nlink = 0; |
300 | atomic_long_inc(&inode->i_sb->s_remove_count); |
301 | } |
302 | } |
303 | EXPORT_SYMBOL(clear_nlink); |
304 | |
305 | /** |
306 | * set_nlink - directly set an inode's link count |
307 | * @inode: inode |
308 | * @nlink: new nlink (should be non-zero) |
309 | * |
310 | * This is a low-level filesystem helper to replace any |
311 | * direct filesystem manipulation of i_nlink. |
312 | */ |
313 | void set_nlink(struct inode *inode, unsigned int nlink) |
314 | { |
315 | if (!nlink) { |
316 | clear_nlink(inode); |
317 | } else { |
318 | /* Yes, some filesystems do change nlink from zero to one */ |
319 | if (inode->i_nlink == 0) |
320 | atomic_long_dec(&inode->i_sb->s_remove_count); |
321 | |
322 | inode->__i_nlink = nlink; |
323 | } |
324 | } |
325 | EXPORT_SYMBOL(set_nlink); |
326 | |
327 | /** |
328 | * inc_nlink - directly increment an inode's link count |
329 | * @inode: inode |
330 | * |
331 | * This is a low-level filesystem helper to replace any |
332 | * direct filesystem manipulation of i_nlink. Currently, |
333 | * it is only here for parity with dec_nlink(). |
334 | */ |
335 | void inc_nlink(struct inode *inode) |
336 | { |
337 | if (unlikely(inode->i_nlink == 0)) { |
338 | WARN_ON(!(inode->i_state & I_LINKABLE)); |
339 | atomic_long_dec(&inode->i_sb->s_remove_count); |
340 | } |
341 | |
342 | inode->__i_nlink++; |
343 | } |
344 | EXPORT_SYMBOL(inc_nlink); |
345 | |
346 | void address_space_init_once(struct address_space *mapping) |
347 | { |
348 | memset(mapping, 0, sizeof(*mapping)); |
349 | INIT_RADIX_TREE(&mapping->page_tree, GFP_ATOMIC); |
350 | spin_lock_init(&mapping->tree_lock); |
351 | mutex_init(&mapping->i_mmap_mutex); |
352 | INIT_LIST_HEAD(&mapping->private_list); |
353 | spin_lock_init(&mapping->private_lock); |
354 | mapping->i_mmap = RB_ROOT; |
355 | INIT_LIST_HEAD(&mapping->i_mmap_nonlinear); |
356 | } |
357 | EXPORT_SYMBOL(address_space_init_once); |
358 | |
359 | /* |
360 | * These are initializations that only need to be done |
361 | * once, because the fields are idempotent across use |
362 | * of the inode, so let the slab aware of that. |
363 | */ |
364 | void inode_init_once(struct inode *inode) |
365 | { |
366 | memset(inode, 0, sizeof(*inode)); |
367 | INIT_HLIST_NODE(&inode->i_hash); |
368 | INIT_LIST_HEAD(&inode->i_devices); |
369 | INIT_LIST_HEAD(&inode->i_wb_list); |
370 | INIT_LIST_HEAD(&inode->i_lru); |
371 | address_space_init_once(&inode->i_data); |
372 | i_size_ordered_init(inode); |
373 | #ifdef CONFIG_FSNOTIFY |
374 | INIT_HLIST_HEAD(&inode->i_fsnotify_marks); |
375 | #endif |
376 | } |
377 | EXPORT_SYMBOL(inode_init_once); |
378 | |
379 | static void init_once(void *foo) |
380 | { |
381 | struct inode *inode = (struct inode *) foo; |
382 | |
383 | inode_init_once(inode); |
384 | } |
385 | |
386 | /* |
387 | * inode->i_lock must be held |
388 | */ |
389 | void __iget(struct inode *inode) |
390 | { |
391 | atomic_inc(&inode->i_count); |
392 | } |
393 | |
394 | /* |
395 | * get additional reference to inode; caller must already hold one. |
396 | */ |
397 | void ihold(struct inode *inode) |
398 | { |
399 | WARN_ON(atomic_inc_return(&inode->i_count) < 2); |
400 | } |
401 | EXPORT_SYMBOL(ihold); |
402 | |
403 | static void inode_lru_list_add(struct inode *inode) |
404 | { |
405 | if (list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru)) |
406 | this_cpu_inc(nr_unused); |
407 | } |
408 | |
409 | /* |
410 | * Add inode to LRU if needed (inode is unused and clean). |
411 | * |
412 | * Needs inode->i_lock held. |
413 | */ |
414 | void inode_add_lru(struct inode *inode) |
415 | { |
416 | if (!(inode->i_state & (I_DIRTY | I_SYNC | I_FREEING | I_WILL_FREE)) && |
417 | !atomic_read(&inode->i_count) && inode->i_sb->s_flags & MS_ACTIVE) |
418 | inode_lru_list_add(inode); |
419 | } |
420 | |
421 | |
422 | static void inode_lru_list_del(struct inode *inode) |
423 | { |
424 | |
425 | if (list_lru_del(&inode->i_sb->s_inode_lru, &inode->i_lru)) |
426 | this_cpu_dec(nr_unused); |
427 | } |
428 | |
429 | /** |
430 | * inode_sb_list_add - add inode to the superblock list of inodes |
431 | * @inode: inode to add |
432 | */ |
433 | void inode_sb_list_add(struct inode *inode) |
434 | { |
435 | spin_lock(&inode_sb_list_lock); |
436 | list_add(&inode->i_sb_list, &inode->i_sb->s_inodes); |
437 | spin_unlock(&inode_sb_list_lock); |
438 | } |
439 | EXPORT_SYMBOL_GPL(inode_sb_list_add); |
440 | |
441 | static inline void inode_sb_list_del(struct inode *inode) |
442 | { |
443 | if (!list_empty(&inode->i_sb_list)) { |
444 | spin_lock(&inode_sb_list_lock); |
445 | list_del_init(&inode->i_sb_list); |
446 | spin_unlock(&inode_sb_list_lock); |
447 | } |
448 | } |
449 | |
450 | static unsigned long hash(struct super_block *sb, unsigned long hashval) |
451 | { |
452 | unsigned long tmp; |
453 | |
454 | tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / |
455 | L1_CACHE_BYTES; |
456 | tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> i_hash_shift); |
457 | return tmp & i_hash_mask; |
458 | } |
459 | |
460 | /** |
461 | * __insert_inode_hash - hash an inode |
462 | * @inode: unhashed inode |
463 | * @hashval: unsigned long value used to locate this object in the |
464 | * inode_hashtable. |
465 | * |
466 | * Add an inode to the inode hash for this superblock. |
467 | */ |
468 | void __insert_inode_hash(struct inode *inode, unsigned long hashval) |
469 | { |
470 | struct hlist_head *b = inode_hashtable + hash(inode->i_sb, hashval); |
471 | |
472 | spin_lock(&inode_hash_lock); |
473 | spin_lock(&inode->i_lock); |
474 | hlist_add_head(&inode->i_hash, b); |
475 | spin_unlock(&inode->i_lock); |
476 | spin_unlock(&inode_hash_lock); |
477 | } |
478 | EXPORT_SYMBOL(__insert_inode_hash); |
479 | |
480 | /** |
481 | * __remove_inode_hash - remove an inode from the hash |
482 | * @inode: inode to unhash |
483 | * |
484 | * Remove an inode from the superblock. |
485 | */ |
486 | void __remove_inode_hash(struct inode *inode) |
487 | { |
488 | spin_lock(&inode_hash_lock); |
489 | spin_lock(&inode->i_lock); |
490 | hlist_del_init(&inode->i_hash); |
491 | spin_unlock(&inode->i_lock); |
492 | spin_unlock(&inode_hash_lock); |
493 | } |
494 | EXPORT_SYMBOL(__remove_inode_hash); |
495 | |
496 | void clear_inode(struct inode *inode) |
497 | { |
498 | might_sleep(); |
499 | /* |
500 | * We have to cycle tree_lock here because reclaim can be still in the |
501 | * process of removing the last page (in __delete_from_page_cache()) |
502 | * and we must not free mapping under it. |
503 | */ |
504 | spin_lock_irq(&inode->i_data.tree_lock); |
505 | BUG_ON(inode->i_data.nrpages); |
506 | spin_unlock_irq(&inode->i_data.tree_lock); |
507 | BUG_ON(!list_empty(&inode->i_data.private_list)); |
508 | BUG_ON(!(inode->i_state & I_FREEING)); |
509 | BUG_ON(inode->i_state & I_CLEAR); |
510 | /* don't need i_lock here, no concurrent mods to i_state */ |
511 | inode->i_state = I_FREEING | I_CLEAR; |
512 | } |
513 | EXPORT_SYMBOL(clear_inode); |
514 | |
515 | /* |
516 | * Free the inode passed in, removing it from the lists it is still connected |
517 | * to. We remove any pages still attached to the inode and wait for any IO that |
518 | * is still in progress before finally destroying the inode. |
519 | * |
520 | * An inode must already be marked I_FREEING so that we avoid the inode being |
521 | * moved back onto lists if we race with other code that manipulates the lists |
522 | * (e.g. writeback_single_inode). The caller is responsible for setting this. |
523 | * |
524 | * An inode must already be removed from the LRU list before being evicted from |
525 | * the cache. This should occur atomically with setting the I_FREEING state |
526 | * flag, so no inodes here should ever be on the LRU when being evicted. |
527 | */ |
528 | static void evict(struct inode *inode) |
529 | { |
530 | const struct super_operations *op = inode->i_sb->s_op; |
531 | |
532 | BUG_ON(!(inode->i_state & I_FREEING)); |
533 | BUG_ON(!list_empty(&inode->i_lru)); |
534 | |
535 | if (!list_empty(&inode->i_wb_list)) |
536 | inode_wb_list_del(inode); |
537 | |
538 | inode_sb_list_del(inode); |
539 | |
540 | /* |
541 | * Wait for flusher thread to be done with the inode so that filesystem |
542 | * does not start destroying it while writeback is still running. Since |
543 | * the inode has I_FREEING set, flusher thread won't start new work on |
544 | * the inode. We just have to wait for running writeback to finish. |
545 | */ |
546 | inode_wait_for_writeback(inode); |
547 | |
548 | if (op->evict_inode) { |
549 | op->evict_inode(inode); |
550 | } else { |
551 | if (inode->i_data.nrpages) |
552 | truncate_inode_pages(&inode->i_data, 0); |
553 | clear_inode(inode); |
554 | } |
555 | if (S_ISBLK(inode->i_mode) && inode->i_bdev) |
556 | bd_forget(inode); |
557 | if (S_ISCHR(inode->i_mode) && inode->i_cdev) |
558 | cd_forget(inode); |
559 | |
560 | remove_inode_hash(inode); |
561 | |
562 | spin_lock(&inode->i_lock); |
563 | wake_up_bit(&inode->i_state, __I_NEW); |
564 | BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); |
565 | spin_unlock(&inode->i_lock); |
566 | |
567 | destroy_inode(inode); |
568 | } |
569 | |
570 | /* |
571 | * dispose_list - dispose of the contents of a local list |
572 | * @head: the head of the list to free |
573 | * |
574 | * Dispose-list gets a local list with local inodes in it, so it doesn't |
575 | * need to worry about list corruption and SMP locks. |
576 | */ |
577 | static void dispose_list(struct list_head *head) |
578 | { |
579 | while (!list_empty(head)) { |
580 | struct inode *inode; |
581 | |
582 | inode = list_first_entry(head, struct inode, i_lru); |
583 | list_del_init(&inode->i_lru); |
584 | |
585 | evict(inode); |
586 | } |
587 | } |
588 | |
589 | /** |
590 | * evict_inodes - evict all evictable inodes for a superblock |
591 | * @sb: superblock to operate on |
592 | * |
593 | * Make sure that no inodes with zero refcount are retained. This is |
594 | * called by superblock shutdown after having MS_ACTIVE flag removed, |
595 | * so any inode reaching zero refcount during or after that call will |
596 | * be immediately evicted. |
597 | */ |
598 | void evict_inodes(struct super_block *sb) |
599 | { |
600 | struct inode *inode, *next; |
601 | LIST_HEAD(dispose); |
602 | |
603 | spin_lock(&inode_sb_list_lock); |
604 | list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { |
605 | if (atomic_read(&inode->i_count)) |
606 | continue; |
607 | |
608 | spin_lock(&inode->i_lock); |
609 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { |
610 | spin_unlock(&inode->i_lock); |
611 | continue; |
612 | } |
613 | |
614 | inode->i_state |= I_FREEING; |
615 | inode_lru_list_del(inode); |
616 | spin_unlock(&inode->i_lock); |
617 | list_add(&inode->i_lru, &dispose); |
618 | } |
619 | spin_unlock(&inode_sb_list_lock); |
620 | |
621 | dispose_list(&dispose); |
622 | } |
623 | |
624 | /** |
625 | * invalidate_inodes - attempt to free all inodes on a superblock |
626 | * @sb: superblock to operate on |
627 | * @kill_dirty: flag to guide handling of dirty inodes |
628 | * |
629 | * Attempts to free all inodes for a given superblock. If there were any |
630 | * busy inodes return a non-zero value, else zero. |
631 | * If @kill_dirty is set, discard dirty inodes too, otherwise treat |
632 | * them as busy. |
633 | */ |
634 | int invalidate_inodes(struct super_block *sb, bool kill_dirty) |
635 | { |
636 | int busy = 0; |
637 | struct inode *inode, *next; |
638 | LIST_HEAD(dispose); |
639 | |
640 | spin_lock(&inode_sb_list_lock); |
641 | list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { |
642 | spin_lock(&inode->i_lock); |
643 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { |
644 | spin_unlock(&inode->i_lock); |
645 | continue; |
646 | } |
647 | if (inode->i_state & I_DIRTY && !kill_dirty) { |
648 | spin_unlock(&inode->i_lock); |
649 | busy = 1; |
650 | continue; |
651 | } |
652 | if (atomic_read(&inode->i_count)) { |
653 | spin_unlock(&inode->i_lock); |
654 | busy = 1; |
655 | continue; |
656 | } |
657 | |
658 | inode->i_state |= I_FREEING; |
659 | inode_lru_list_del(inode); |
660 | spin_unlock(&inode->i_lock); |
661 | list_add(&inode->i_lru, &dispose); |
662 | } |
663 | spin_unlock(&inode_sb_list_lock); |
664 | |
665 | dispose_list(&dispose); |
666 | |
667 | return busy; |
668 | } |
669 | |
670 | /* |
671 | * Isolate the inode from the LRU in preparation for freeing it. |
672 | * |
673 | * Any inodes which are pinned purely because of attached pagecache have their |
674 | * pagecache removed. If the inode has metadata buffers attached to |
675 | * mapping->private_list then try to remove them. |
676 | * |
677 | * If the inode has the I_REFERENCED flag set, then it means that it has been |
678 | * used recently - the flag is set in iput_final(). When we encounter such an |
679 | * inode, clear the flag and move it to the back of the LRU so it gets another |
680 | * pass through the LRU before it gets reclaimed. This is necessary because of |
681 | * the fact we are doing lazy LRU updates to minimise lock contention so the |
682 | * LRU does not have strict ordering. Hence we don't want to reclaim inodes |
683 | * with this flag set because they are the inodes that are out of order. |
684 | */ |
685 | static enum lru_status |
686 | inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg) |
687 | { |
688 | struct list_head *freeable = arg; |
689 | struct inode *inode = container_of(item, struct inode, i_lru); |
690 | |
691 | /* |
692 | * we are inverting the lru lock/inode->i_lock here, so use a trylock. |
693 | * If we fail to get the lock, just skip it. |
694 | */ |
695 | if (!spin_trylock(&inode->i_lock)) |
696 | return LRU_SKIP; |
697 | |
698 | /* |
699 | * Referenced or dirty inodes are still in use. Give them another pass |
700 | * through the LRU as we canot reclaim them now. |
701 | */ |
702 | if (atomic_read(&inode->i_count) || |
703 | (inode->i_state & ~I_REFERENCED)) { |
704 | list_del_init(&inode->i_lru); |
705 | spin_unlock(&inode->i_lock); |
706 | this_cpu_dec(nr_unused); |
707 | return LRU_REMOVED; |
708 | } |
709 | |
710 | /* recently referenced inodes get one more pass */ |
711 | if (inode->i_state & I_REFERENCED) { |
712 | inode->i_state &= ~I_REFERENCED; |
713 | spin_unlock(&inode->i_lock); |
714 | return LRU_ROTATE; |
715 | } |
716 | |
717 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { |
718 | __iget(inode); |
719 | spin_unlock(&inode->i_lock); |
720 | spin_unlock(lru_lock); |
721 | if (remove_inode_buffers(inode)) { |
722 | unsigned long reap; |
723 | reap = invalidate_mapping_pages(&inode->i_data, 0, -1); |
724 | if (current_is_kswapd()) |
725 | __count_vm_events(KSWAPD_INODESTEAL, reap); |
726 | else |
727 | __count_vm_events(PGINODESTEAL, reap); |
728 | if (current->reclaim_state) |
729 | current->reclaim_state->reclaimed_slab += reap; |
730 | } |
731 | iput(inode); |
732 | spin_lock(lru_lock); |
733 | return LRU_RETRY; |
734 | } |
735 | |
736 | WARN_ON(inode->i_state & I_NEW); |
737 | inode->i_state |= I_FREEING; |
738 | list_move(&inode->i_lru, freeable); |
739 | spin_unlock(&inode->i_lock); |
740 | |
741 | this_cpu_dec(nr_unused); |
742 | return LRU_REMOVED; |
743 | } |
744 | |
745 | /* |
746 | * Walk the superblock inode LRU for freeable inodes and attempt to free them. |
747 | * This is called from the superblock shrinker function with a number of inodes |
748 | * to trim from the LRU. Inodes to be freed are moved to a temporary list and |
749 | * then are freed outside inode_lock by dispose_list(). |
750 | */ |
751 | long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan, |
752 | int nid) |
753 | { |
754 | LIST_HEAD(freeable); |
755 | long freed; |
756 | |
757 | freed = list_lru_walk_node(&sb->s_inode_lru, nid, inode_lru_isolate, |
758 | &freeable, &nr_to_scan); |
759 | dispose_list(&freeable); |
760 | return freed; |
761 | } |
762 | |
763 | static void __wait_on_freeing_inode(struct inode *inode); |
764 | /* |
765 | * Called with the inode lock held. |
766 | */ |
767 | static struct inode *find_inode(struct super_block *sb, |
768 | struct hlist_head *head, |
769 | int (*test)(struct inode *, void *), |
770 | void *data) |
771 | { |
772 | struct inode *inode = NULL; |
773 | |
774 | repeat: |
775 | hlist_for_each_entry(inode, head, i_hash) { |
776 | spin_lock(&inode->i_lock); |
777 | if (inode->i_sb != sb) { |
778 | spin_unlock(&inode->i_lock); |
779 | continue; |
780 | } |
781 | if (!test(inode, data)) { |
782 | spin_unlock(&inode->i_lock); |
783 | continue; |
784 | } |
785 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
786 | __wait_on_freeing_inode(inode); |
787 | goto repeat; |
788 | } |
789 | __iget(inode); |
790 | spin_unlock(&inode->i_lock); |
791 | return inode; |
792 | } |
793 | return NULL; |
794 | } |
795 | |
796 | /* |
797 | * find_inode_fast is the fast path version of find_inode, see the comment at |
798 | * iget_locked for details. |
799 | */ |
800 | static struct inode *find_inode_fast(struct super_block *sb, |
801 | struct hlist_head *head, unsigned long ino) |
802 | { |
803 | struct inode *inode = NULL; |
804 | |
805 | repeat: |
806 | hlist_for_each_entry(inode, head, i_hash) { |
807 | spin_lock(&inode->i_lock); |
808 | if (inode->i_ino != ino) { |
809 | spin_unlock(&inode->i_lock); |
810 | continue; |
811 | } |
812 | if (inode->i_sb != sb) { |
813 | spin_unlock(&inode->i_lock); |
814 | continue; |
815 | } |
816 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
817 | __wait_on_freeing_inode(inode); |
818 | goto repeat; |
819 | } |
820 | __iget(inode); |
821 | spin_unlock(&inode->i_lock); |
822 | return inode; |
823 | } |
824 | return NULL; |
825 | } |
826 | |
827 | /* |
828 | * Each cpu owns a range of LAST_INO_BATCH numbers. |
829 | * 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations, |
830 | * to renew the exhausted range. |
831 | * |
832 | * This does not significantly increase overflow rate because every CPU can |
833 | * consume at most LAST_INO_BATCH-1 unused inode numbers. So there is |
834 | * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the |
835 | * 2^32 range, and is a worst-case. Even a 50% wastage would only increase |
836 | * overflow rate by 2x, which does not seem too significant. |
837 | * |
838 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW |
839 | * error if st_ino won't fit in target struct field. Use 32bit counter |
840 | * here to attempt to avoid that. |
841 | */ |
842 | #define LAST_INO_BATCH 1024 |
843 | static DEFINE_PER_CPU(unsigned int, last_ino); |
844 | |
845 | unsigned int get_next_ino(void) |
846 | { |
847 | unsigned int *p = &get_cpu_var(last_ino); |
848 | unsigned int res = *p; |
849 | |
850 | #ifdef CONFIG_SMP |
851 | if (unlikely((res & (LAST_INO_BATCH-1)) == 0)) { |
852 | static atomic_t shared_last_ino; |
853 | int next = atomic_add_return(LAST_INO_BATCH, &shared_last_ino); |
854 | |
855 | res = next - LAST_INO_BATCH; |
856 | } |
857 | #endif |
858 | |
859 | *p = ++res; |
860 | put_cpu_var(last_ino); |
861 | return res; |
862 | } |
863 | EXPORT_SYMBOL(get_next_ino); |
864 | |
865 | /** |
866 | * new_inode_pseudo - obtain an inode |
867 | * @sb: superblock |
868 | * |
869 | * Allocates a new inode for given superblock. |
870 | * Inode wont be chained in superblock s_inodes list |
871 | * This means : |
872 | * - fs can't be unmount |
873 | * - quotas, fsnotify, writeback can't work |
874 | */ |
875 | struct inode *new_inode_pseudo(struct super_block *sb) |
876 | { |
877 | struct inode *inode = alloc_inode(sb); |
878 | |
879 | if (inode) { |
880 | spin_lock(&inode->i_lock); |
881 | inode->i_state = 0; |
882 | spin_unlock(&inode->i_lock); |
883 | INIT_LIST_HEAD(&inode->i_sb_list); |
884 | } |
885 | return inode; |
886 | } |
887 | |
888 | /** |
889 | * new_inode - obtain an inode |
890 | * @sb: superblock |
891 | * |
892 | * Allocates a new inode for given superblock. The default gfp_mask |
893 | * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE. |
894 | * If HIGHMEM pages are unsuitable or it is known that pages allocated |
895 | * for the page cache are not reclaimable or migratable, |
896 | * mapping_set_gfp_mask() must be called with suitable flags on the |
897 | * newly created inode's mapping |
898 | * |
899 | */ |
900 | struct inode *new_inode(struct super_block *sb) |
901 | { |
902 | struct inode *inode; |
903 | |
904 | spin_lock_prefetch(&inode_sb_list_lock); |
905 | |
906 | inode = new_inode_pseudo(sb); |
907 | if (inode) |
908 | inode_sb_list_add(inode); |
909 | return inode; |
910 | } |
911 | EXPORT_SYMBOL(new_inode); |
912 | |
913 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
914 | void lockdep_annotate_inode_mutex_key(struct inode *inode) |
915 | { |
916 | if (S_ISDIR(inode->i_mode)) { |
917 | struct file_system_type *type = inode->i_sb->s_type; |
918 | |
919 | /* Set new key only if filesystem hasn't already changed it */ |
920 | if (lockdep_match_class(&inode->i_mutex, &type->i_mutex_key)) { |
921 | /* |
922 | * ensure nobody is actually holding i_mutex |
923 | */ |
924 | mutex_destroy(&inode->i_mutex); |
925 | mutex_init(&inode->i_mutex); |
926 | lockdep_set_class(&inode->i_mutex, |
927 | &type->i_mutex_dir_key); |
928 | } |
929 | } |
930 | } |
931 | EXPORT_SYMBOL(lockdep_annotate_inode_mutex_key); |
932 | #endif |
933 | |
934 | /** |
935 | * unlock_new_inode - clear the I_NEW state and wake up any waiters |
936 | * @inode: new inode to unlock |
937 | * |
938 | * Called when the inode is fully initialised to clear the new state of the |
939 | * inode and wake up anyone waiting for the inode to finish initialisation. |
940 | */ |
941 | void unlock_new_inode(struct inode *inode) |
942 | { |
943 | lockdep_annotate_inode_mutex_key(inode); |
944 | spin_lock(&inode->i_lock); |
945 | WARN_ON(!(inode->i_state & I_NEW)); |
946 | inode->i_state &= ~I_NEW; |
947 | smp_mb(); |
948 | wake_up_bit(&inode->i_state, __I_NEW); |
949 | spin_unlock(&inode->i_lock); |
950 | } |
951 | EXPORT_SYMBOL(unlock_new_inode); |
952 | |
953 | /** |
954 | * iget5_locked - obtain an inode from a mounted file system |
955 | * @sb: super block of file system |
956 | * @hashval: hash value (usually inode number) to get |
957 | * @test: callback used for comparisons between inodes |
958 | * @set: callback used to initialize a new struct inode |
959 | * @data: opaque data pointer to pass to @test and @set |
960 | * |
961 | * Search for the inode specified by @hashval and @data in the inode cache, |
962 | * and if present it is return it with an increased reference count. This is |
963 | * a generalized version of iget_locked() for file systems where the inode |
964 | * number is not sufficient for unique identification of an inode. |
965 | * |
966 | * If the inode is not in cache, allocate a new inode and return it locked, |
967 | * hashed, and with the I_NEW flag set. The file system gets to fill it in |
968 | * before unlocking it via unlock_new_inode(). |
969 | * |
970 | * Note both @test and @set are called with the inode_hash_lock held, so can't |
971 | * sleep. |
972 | */ |
973 | struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, |
974 | int (*test)(struct inode *, void *), |
975 | int (*set)(struct inode *, void *), void *data) |
976 | { |
977 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); |
978 | struct inode *inode; |
979 | |
980 | spin_lock(&inode_hash_lock); |
981 | inode = find_inode(sb, head, test, data); |
982 | spin_unlock(&inode_hash_lock); |
983 | |
984 | if (inode) { |
985 | wait_on_inode(inode); |
986 | return inode; |
987 | } |
988 | |
989 | inode = alloc_inode(sb); |
990 | if (inode) { |
991 | struct inode *old; |
992 | |
993 | spin_lock(&inode_hash_lock); |
994 | /* We released the lock, so.. */ |
995 | old = find_inode(sb, head, test, data); |
996 | if (!old) { |
997 | if (set(inode, data)) |
998 | goto set_failed; |
999 | |
1000 | spin_lock(&inode->i_lock); |
1001 | inode->i_state = I_NEW; |
1002 | hlist_add_head(&inode->i_hash, head); |
1003 | spin_unlock(&inode->i_lock); |
1004 | inode_sb_list_add(inode); |
1005 | spin_unlock(&inode_hash_lock); |
1006 | |
1007 | /* Return the locked inode with I_NEW set, the |
1008 | * caller is responsible for filling in the contents |
1009 | */ |
1010 | return inode; |
1011 | } |
1012 | |
1013 | /* |
1014 | * Uhhuh, somebody else created the same inode under |
1015 | * us. Use the old inode instead of the one we just |
1016 | * allocated. |
1017 | */ |
1018 | spin_unlock(&inode_hash_lock); |
1019 | destroy_inode(inode); |
1020 | inode = old; |
1021 | wait_on_inode(inode); |
1022 | } |
1023 | return inode; |
1024 | |
1025 | set_failed: |
1026 | spin_unlock(&inode_hash_lock); |
1027 | destroy_inode(inode); |
1028 | return NULL; |
1029 | } |
1030 | EXPORT_SYMBOL(iget5_locked); |
1031 | |
1032 | /** |
1033 | * iget_locked - obtain an inode from a mounted file system |
1034 | * @sb: super block of file system |
1035 | * @ino: inode number to get |
1036 | * |
1037 | * Search for the inode specified by @ino in the inode cache and if present |
1038 | * return it with an increased reference count. This is for file systems |
1039 | * where the inode number is sufficient for unique identification of an inode. |
1040 | * |
1041 | * If the inode is not in cache, allocate a new inode and return it locked, |
1042 | * hashed, and with the I_NEW flag set. The file system gets to fill it in |
1043 | * before unlocking it via unlock_new_inode(). |
1044 | */ |
1045 | struct inode *iget_locked(struct super_block *sb, unsigned long ino) |
1046 | { |
1047 | struct hlist_head *head = inode_hashtable + hash(sb, ino); |
1048 | struct inode *inode; |
1049 | |
1050 | spin_lock(&inode_hash_lock); |
1051 | inode = find_inode_fast(sb, head, ino); |
1052 | spin_unlock(&inode_hash_lock); |
1053 | if (inode) { |
1054 | wait_on_inode(inode); |
1055 | return inode; |
1056 | } |
1057 | |
1058 | inode = alloc_inode(sb); |
1059 | if (inode) { |
1060 | struct inode *old; |
1061 | |
1062 | spin_lock(&inode_hash_lock); |
1063 | /* We released the lock, so.. */ |
1064 | old = find_inode_fast(sb, head, ino); |
1065 | if (!old) { |
1066 | inode->i_ino = ino; |
1067 | spin_lock(&inode->i_lock); |
1068 | inode->i_state = I_NEW; |
1069 | hlist_add_head(&inode->i_hash, head); |
1070 | spin_unlock(&inode->i_lock); |
1071 | inode_sb_list_add(inode); |
1072 | spin_unlock(&inode_hash_lock); |
1073 | |
1074 | /* Return the locked inode with I_NEW set, the |
1075 | * caller is responsible for filling in the contents |
1076 | */ |
1077 | return inode; |
1078 | } |
1079 | |
1080 | /* |
1081 | * Uhhuh, somebody else created the same inode under |
1082 | * us. Use the old inode instead of the one we just |
1083 | * allocated. |
1084 | */ |
1085 | spin_unlock(&inode_hash_lock); |
1086 | destroy_inode(inode); |
1087 | inode = old; |
1088 | wait_on_inode(inode); |
1089 | } |
1090 | return inode; |
1091 | } |
1092 | EXPORT_SYMBOL(iget_locked); |
1093 | |
1094 | /* |
1095 | * search the inode cache for a matching inode number. |
1096 | * If we find one, then the inode number we are trying to |
1097 | * allocate is not unique and so we should not use it. |
1098 | * |
1099 | * Returns 1 if the inode number is unique, 0 if it is not. |
1100 | */ |
1101 | static int test_inode_iunique(struct super_block *sb, unsigned long ino) |
1102 | { |
1103 | struct hlist_head *b = inode_hashtable + hash(sb, ino); |
1104 | struct inode *inode; |
1105 | |
1106 | spin_lock(&inode_hash_lock); |
1107 | hlist_for_each_entry(inode, b, i_hash) { |
1108 | if (inode->i_ino == ino && inode->i_sb == sb) { |
1109 | spin_unlock(&inode_hash_lock); |
1110 | return 0; |
1111 | } |
1112 | } |
1113 | spin_unlock(&inode_hash_lock); |
1114 | |
1115 | return 1; |
1116 | } |
1117 | |
1118 | /** |
1119 | * iunique - get a unique inode number |
1120 | * @sb: superblock |
1121 | * @max_reserved: highest reserved inode number |
1122 | * |
1123 | * Obtain an inode number that is unique on the system for a given |
1124 | * superblock. This is used by file systems that have no natural |
1125 | * permanent inode numbering system. An inode number is returned that |
1126 | * is higher than the reserved limit but unique. |
1127 | * |
1128 | * BUGS: |
1129 | * With a large number of inodes live on the file system this function |
1130 | * currently becomes quite slow. |
1131 | */ |
1132 | ino_t iunique(struct super_block *sb, ino_t max_reserved) |
1133 | { |
1134 | /* |
1135 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW |
1136 | * error if st_ino won't fit in target struct field. Use 32bit counter |
1137 | * here to attempt to avoid that. |
1138 | */ |
1139 | static DEFINE_SPINLOCK(iunique_lock); |
1140 | static unsigned int counter; |
1141 | ino_t res; |
1142 | |
1143 | spin_lock(&iunique_lock); |
1144 | do { |
1145 | if (counter <= max_reserved) |
1146 | counter = max_reserved + 1; |
1147 | res = counter++; |
1148 | } while (!test_inode_iunique(sb, res)); |
1149 | spin_unlock(&iunique_lock); |
1150 | |
1151 | return res; |
1152 | } |
1153 | EXPORT_SYMBOL(iunique); |
1154 | |
1155 | struct inode *igrab(struct inode *inode) |
1156 | { |
1157 | spin_lock(&inode->i_lock); |
1158 | if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) { |
1159 | __iget(inode); |
1160 | spin_unlock(&inode->i_lock); |
1161 | } else { |
1162 | spin_unlock(&inode->i_lock); |
1163 | /* |
1164 | * Handle the case where s_op->clear_inode is not been |
1165 | * called yet, and somebody is calling igrab |
1166 | * while the inode is getting freed. |
1167 | */ |
1168 | inode = NULL; |
1169 | } |
1170 | return inode; |
1171 | } |
1172 | EXPORT_SYMBOL(igrab); |
1173 | |
1174 | /** |
1175 | * ilookup5_nowait - search for an inode in the inode cache |
1176 | * @sb: super block of file system to search |
1177 | * @hashval: hash value (usually inode number) to search for |
1178 | * @test: callback used for comparisons between inodes |
1179 | * @data: opaque data pointer to pass to @test |
1180 | * |
1181 | * Search for the inode specified by @hashval and @data in the inode cache. |
1182 | * If the inode is in the cache, the inode is returned with an incremented |
1183 | * reference count. |
1184 | * |
1185 | * Note: I_NEW is not waited upon so you have to be very careful what you do |
1186 | * with the returned inode. You probably should be using ilookup5() instead. |
1187 | * |
1188 | * Note2: @test is called with the inode_hash_lock held, so can't sleep. |
1189 | */ |
1190 | struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, |
1191 | int (*test)(struct inode *, void *), void *data) |
1192 | { |
1193 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); |
1194 | struct inode *inode; |
1195 | |
1196 | spin_lock(&inode_hash_lock); |
1197 | inode = find_inode(sb, head, test, data); |
1198 | spin_unlock(&inode_hash_lock); |
1199 | |
1200 | return inode; |
1201 | } |
1202 | EXPORT_SYMBOL(ilookup5_nowait); |
1203 | |
1204 | /** |
1205 | * ilookup5 - search for an inode in the inode cache |
1206 | * @sb: super block of file system to search |
1207 | * @hashval: hash value (usually inode number) to search for |
1208 | * @test: callback used for comparisons between inodes |
1209 | * @data: opaque data pointer to pass to @test |
1210 | * |
1211 | * Search for the inode specified by @hashval and @data in the inode cache, |
1212 | * and if the inode is in the cache, return the inode with an incremented |
1213 | * reference count. Waits on I_NEW before returning the inode. |
1214 | * returned with an incremented reference count. |
1215 | * |
1216 | * This is a generalized version of ilookup() for file systems where the |
1217 | * inode number is not sufficient for unique identification of an inode. |
1218 | * |
1219 | * Note: @test is called with the inode_hash_lock held, so can't sleep. |
1220 | */ |
1221 | struct inode *ilookup5(struct super_block *sb, unsigned long hashval, |
1222 | int (*test)(struct inode *, void *), void *data) |
1223 | { |
1224 | struct inode *inode = ilookup5_nowait(sb, hashval, test, data); |
1225 | |
1226 | if (inode) |
1227 | wait_on_inode(inode); |
1228 | return inode; |
1229 | } |
1230 | EXPORT_SYMBOL(ilookup5); |
1231 | |
1232 | /** |
1233 | * ilookup - search for an inode in the inode cache |
1234 | * @sb: super block of file system to search |
1235 | * @ino: inode number to search for |
1236 | * |
1237 | * Search for the inode @ino in the inode cache, and if the inode is in the |
1238 | * cache, the inode is returned with an incremented reference count. |
1239 | */ |
1240 | struct inode *ilookup(struct super_block *sb, unsigned long ino) |
1241 | { |
1242 | struct hlist_head *head = inode_hashtable + hash(sb, ino); |
1243 | struct inode *inode; |
1244 | |
1245 | spin_lock(&inode_hash_lock); |
1246 | inode = find_inode_fast(sb, head, ino); |
1247 | spin_unlock(&inode_hash_lock); |
1248 | |
1249 | if (inode) |
1250 | wait_on_inode(inode); |
1251 | return inode; |
1252 | } |
1253 | EXPORT_SYMBOL(ilookup); |
1254 | |
1255 | int insert_inode_locked(struct inode *inode) |
1256 | { |
1257 | struct super_block *sb = inode->i_sb; |
1258 | ino_t ino = inode->i_ino; |
1259 | struct hlist_head *head = inode_hashtable + hash(sb, ino); |
1260 | |
1261 | while (1) { |
1262 | struct inode *old = NULL; |
1263 | spin_lock(&inode_hash_lock); |
1264 | hlist_for_each_entry(old, head, i_hash) { |
1265 | if (old->i_ino != ino) |
1266 | continue; |
1267 | if (old->i_sb != sb) |
1268 | continue; |
1269 | spin_lock(&old->i_lock); |
1270 | if (old->i_state & (I_FREEING|I_WILL_FREE)) { |
1271 | spin_unlock(&old->i_lock); |
1272 | continue; |
1273 | } |
1274 | break; |
1275 | } |
1276 | if (likely(!old)) { |
1277 | spin_lock(&inode->i_lock); |
1278 | inode->i_state |= I_NEW; |
1279 | hlist_add_head(&inode->i_hash, head); |
1280 | spin_unlock(&inode->i_lock); |
1281 | spin_unlock(&inode_hash_lock); |
1282 | return 0; |
1283 | } |
1284 | __iget(old); |
1285 | spin_unlock(&old->i_lock); |
1286 | spin_unlock(&inode_hash_lock); |
1287 | wait_on_inode(old); |
1288 | if (unlikely(!inode_unhashed(old))) { |
1289 | iput(old); |
1290 | return -EBUSY; |
1291 | } |
1292 | iput(old); |
1293 | } |
1294 | } |
1295 | EXPORT_SYMBOL(insert_inode_locked); |
1296 | |
1297 | int insert_inode_locked4(struct inode *inode, unsigned long hashval, |
1298 | int (*test)(struct inode *, void *), void *data) |
1299 | { |
1300 | struct super_block *sb = inode->i_sb; |
1301 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); |
1302 | |
1303 | while (1) { |
1304 | struct inode *old = NULL; |
1305 | |
1306 | spin_lock(&inode_hash_lock); |
1307 | hlist_for_each_entry(old, head, i_hash) { |
1308 | if (old->i_sb != sb) |
1309 | continue; |
1310 | if (!test(old, data)) |
1311 | continue; |
1312 | spin_lock(&old->i_lock); |
1313 | if (old->i_state & (I_FREEING|I_WILL_FREE)) { |
1314 | spin_unlock(&old->i_lock); |
1315 | continue; |
1316 | } |
1317 | break; |
1318 | } |
1319 | if (likely(!old)) { |
1320 | spin_lock(&inode->i_lock); |
1321 | inode->i_state |= I_NEW; |
1322 | hlist_add_head(&inode->i_hash, head); |
1323 | spin_unlock(&inode->i_lock); |
1324 | spin_unlock(&inode_hash_lock); |
1325 | return 0; |
1326 | } |
1327 | __iget(old); |
1328 | spin_unlock(&old->i_lock); |
1329 | spin_unlock(&inode_hash_lock); |
1330 | wait_on_inode(old); |
1331 | if (unlikely(!inode_unhashed(old))) { |
1332 | iput(old); |
1333 | return -EBUSY; |
1334 | } |
1335 | iput(old); |
1336 | } |
1337 | } |
1338 | EXPORT_SYMBOL(insert_inode_locked4); |
1339 | |
1340 | |
1341 | int generic_delete_inode(struct inode *inode) |
1342 | { |
1343 | return 1; |
1344 | } |
1345 | EXPORT_SYMBOL(generic_delete_inode); |
1346 | |
1347 | /* |
1348 | * Called when we're dropping the last reference |
1349 | * to an inode. |
1350 | * |
1351 | * Call the FS "drop_inode()" function, defaulting to |
1352 | * the legacy UNIX filesystem behaviour. If it tells |
1353 | * us to evict inode, do so. Otherwise, retain inode |
1354 | * in cache if fs is alive, sync and evict if fs is |
1355 | * shutting down. |
1356 | */ |
1357 | static void iput_final(struct inode *inode) |
1358 | { |
1359 | struct super_block *sb = inode->i_sb; |
1360 | const struct super_operations *op = inode->i_sb->s_op; |
1361 | int drop; |
1362 | |
1363 | WARN_ON(inode->i_state & I_NEW); |
1364 | |
1365 | if (op->drop_inode) |
1366 | drop = op->drop_inode(inode); |
1367 | else |
1368 | drop = generic_drop_inode(inode); |
1369 | |
1370 | if (!drop && (sb->s_flags & MS_ACTIVE)) { |
1371 | inode->i_state |= I_REFERENCED; |
1372 | inode_add_lru(inode); |
1373 | spin_unlock(&inode->i_lock); |
1374 | return; |
1375 | } |
1376 | |
1377 | if (!drop) { |
1378 | inode->i_state |= I_WILL_FREE; |
1379 | spin_unlock(&inode->i_lock); |
1380 | write_inode_now(inode, 1); |
1381 | spin_lock(&inode->i_lock); |
1382 | WARN_ON(inode->i_state & I_NEW); |
1383 | inode->i_state &= ~I_WILL_FREE; |
1384 | } |
1385 | |
1386 | inode->i_state |= I_FREEING; |
1387 | if (!list_empty(&inode->i_lru)) |
1388 | inode_lru_list_del(inode); |
1389 | spin_unlock(&inode->i_lock); |
1390 | |
1391 | evict(inode); |
1392 | } |
1393 | |
1394 | /** |
1395 | * iput - put an inode |
1396 | * @inode: inode to put |
1397 | * |
1398 | * Puts an inode, dropping its usage count. If the inode use count hits |
1399 | * zero, the inode is then freed and may also be destroyed. |
1400 | * |
1401 | * Consequently, iput() can sleep. |
1402 | */ |
1403 | void iput(struct inode *inode) |
1404 | { |
1405 | if (inode) { |
1406 | BUG_ON(inode->i_state & I_CLEAR); |
1407 | |
1408 | if (atomic_dec_and_lock(&inode->i_count, &inode->i_lock)) |
1409 | iput_final(inode); |
1410 | } |
1411 | } |
1412 | EXPORT_SYMBOL(iput); |
1413 | |
1414 | /** |
1415 | * bmap - find a block number in a file |
1416 | * @inode: inode of file |
1417 | * @block: block to find |
1418 | * |
1419 | * Returns the block number on the device holding the inode that |
1420 | * is the disk block number for the block of the file requested. |
1421 | * That is, asked for block 4 of inode 1 the function will return the |
1422 | * disk block relative to the disk start that holds that block of the |
1423 | * file. |
1424 | */ |
1425 | sector_t bmap(struct inode *inode, sector_t block) |
1426 | { |
1427 | sector_t res = 0; |
1428 | if (inode->i_mapping->a_ops->bmap) |
1429 | res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); |
1430 | return res; |
1431 | } |
1432 | EXPORT_SYMBOL(bmap); |
1433 | |
1434 | /* |
1435 | * With relative atime, only update atime if the previous atime is |
1436 | * earlier than either the ctime or mtime or if at least a day has |
1437 | * passed since the last atime update. |
1438 | */ |
1439 | static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, |
1440 | struct timespec now) |
1441 | { |
1442 | |
1443 | if (!(mnt->mnt_flags & MNT_RELATIME)) |
1444 | return 1; |
1445 | /* |
1446 | * Is mtime younger than atime? If yes, update atime: |
1447 | */ |
1448 | if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0) |
1449 | return 1; |
1450 | /* |
1451 | * Is ctime younger than atime? If yes, update atime: |
1452 | */ |
1453 | if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0) |
1454 | return 1; |
1455 | |
1456 | /* |
1457 | * Is the previous atime value older than a day? If yes, |
1458 | * update atime: |
1459 | */ |
1460 | if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60) |
1461 | return 1; |
1462 | /* |
1463 | * Good, we can skip the atime update: |
1464 | */ |
1465 | return 0; |
1466 | } |
1467 | |
1468 | /* |
1469 | * This does the actual work of updating an inodes time or version. Must have |
1470 | * had called mnt_want_write() before calling this. |
1471 | */ |
1472 | static int update_time(struct inode *inode, struct timespec *time, int flags) |
1473 | { |
1474 | if (inode->i_op->update_time) |
1475 | return inode->i_op->update_time(inode, time, flags); |
1476 | |
1477 | if (flags & S_ATIME) |
1478 | inode->i_atime = *time; |
1479 | if (flags & S_VERSION) |
1480 | inode_inc_iversion(inode); |
1481 | if (flags & S_CTIME) |
1482 | inode->i_ctime = *time; |
1483 | if (flags & S_MTIME) |
1484 | inode->i_mtime = *time; |
1485 | mark_inode_dirty_sync(inode); |
1486 | return 0; |
1487 | } |
1488 | |
1489 | /** |
1490 | * touch_atime - update the access time |
1491 | * @path: the &struct path to update |
1492 | * |
1493 | * Update the accessed time on an inode and mark it for writeback. |
1494 | * This function automatically handles read only file systems and media, |
1495 | * as well as the "noatime" flag and inode specific "noatime" markers. |
1496 | */ |
1497 | void touch_atime(const struct path *path) |
1498 | { |
1499 | struct vfsmount *mnt = path->mnt; |
1500 | struct inode *inode = path->dentry->d_inode; |
1501 | struct timespec now; |
1502 | |
1503 | if (inode->i_flags & S_NOATIME) |
1504 | return; |
1505 | if (IS_NOATIME(inode)) |
1506 | return; |
1507 | if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode)) |
1508 | return; |
1509 | |
1510 | if (mnt->mnt_flags & MNT_NOATIME) |
1511 | return; |
1512 | if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)) |
1513 | return; |
1514 | |
1515 | now = current_fs_time(inode->i_sb); |
1516 | |
1517 | if (!relatime_need_update(mnt, inode, now)) |
1518 | return; |
1519 | |
1520 | if (timespec_equal(&inode->i_atime, &now)) |
1521 | return; |
1522 | |
1523 | if (!sb_start_write_trylock(inode->i_sb)) |
1524 | return; |
1525 | |
1526 | if (__mnt_want_write(mnt)) |
1527 | goto skip_update; |
1528 | /* |
1529 | * File systems can error out when updating inodes if they need to |
1530 | * allocate new space to modify an inode (such is the case for |
1531 | * Btrfs), but since we touch atime while walking down the path we |
1532 | * really don't care if we failed to update the atime of the file, |
1533 | * so just ignore the return value. |
1534 | * We may also fail on filesystems that have the ability to make parts |
1535 | * of the fs read only, e.g. subvolumes in Btrfs. |
1536 | */ |
1537 | update_time(inode, &now, S_ATIME); |
1538 | __mnt_drop_write(mnt); |
1539 | skip_update: |
1540 | sb_end_write(inode->i_sb); |
1541 | } |
1542 | EXPORT_SYMBOL(touch_atime); |
1543 | |
1544 | /* |
1545 | * The logic we want is |
1546 | * |
1547 | * if suid or (sgid and xgrp) |
1548 | * remove privs |
1549 | */ |
1550 | int should_remove_suid(struct dentry *dentry) |
1551 | { |
1552 | umode_t mode = dentry->d_inode->i_mode; |
1553 | int kill = 0; |
1554 | |
1555 | /* suid always must be killed */ |
1556 | if (unlikely(mode & S_ISUID)) |
1557 | kill = ATTR_KILL_SUID; |
1558 | |
1559 | /* |
1560 | * sgid without any exec bits is just a mandatory locking mark; leave |
1561 | * it alone. If some exec bits are set, it's a real sgid; kill it. |
1562 | */ |
1563 | if (unlikely((mode & S_ISGID) && (mode & S_IXGRP))) |
1564 | kill |= ATTR_KILL_SGID; |
1565 | |
1566 | if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode))) |
1567 | return kill; |
1568 | |
1569 | return 0; |
1570 | } |
1571 | EXPORT_SYMBOL(should_remove_suid); |
1572 | |
1573 | static int __remove_suid(struct dentry *dentry, int kill) |
1574 | { |
1575 | struct iattr newattrs; |
1576 | |
1577 | newattrs.ia_valid = ATTR_FORCE | kill; |
1578 | return notify_change(dentry, &newattrs); |
1579 | } |
1580 | |
1581 | int file_remove_suid(struct file *file) |
1582 | { |
1583 | struct dentry *dentry = file->f_path.dentry; |
1584 | struct inode *inode = dentry->d_inode; |
1585 | int killsuid; |
1586 | int killpriv; |
1587 | int error = 0; |
1588 | |
1589 | /* Fast path for nothing security related */ |
1590 | if (IS_NOSEC(inode)) |
1591 | return 0; |
1592 | |
1593 | killsuid = should_remove_suid(dentry); |
1594 | killpriv = security_inode_need_killpriv(dentry); |
1595 | |
1596 | if (killpriv < 0) |
1597 | return killpriv; |
1598 | if (killpriv) |
1599 | error = security_inode_killpriv(dentry); |
1600 | if (!error && killsuid) |
1601 | error = __remove_suid(dentry, killsuid); |
1602 | if (!error && (inode->i_sb->s_flags & MS_NOSEC)) |
1603 | inode->i_flags |= S_NOSEC; |
1604 | |
1605 | return error; |
1606 | } |
1607 | EXPORT_SYMBOL(file_remove_suid); |
1608 | |
1609 | /** |
1610 | * file_update_time - update mtime and ctime time |
1611 | * @file: file accessed |
1612 | * |
1613 | * Update the mtime and ctime members of an inode and mark the inode |
1614 | * for writeback. Note that this function is meant exclusively for |
1615 | * usage in the file write path of filesystems, and filesystems may |
1616 | * choose to explicitly ignore update via this function with the |
1617 | * S_NOCMTIME inode flag, e.g. for network filesystem where these |
1618 | * timestamps are handled by the server. This can return an error for |
1619 | * file systems who need to allocate space in order to update an inode. |
1620 | */ |
1621 | |
1622 | int file_update_time(struct file *file) |
1623 | { |
1624 | struct inode *inode = file_inode(file); |
1625 | struct timespec now; |
1626 | int sync_it = 0; |
1627 | int ret; |
1628 | |
1629 | /* First try to exhaust all avenues to not sync */ |
1630 | if (IS_NOCMTIME(inode)) |
1631 | return 0; |
1632 | |
1633 | now = current_fs_time(inode->i_sb); |
1634 | if (!timespec_equal(&inode->i_mtime, &now)) |
1635 | sync_it = S_MTIME; |
1636 | |
1637 | if (!timespec_equal(&inode->i_ctime, &now)) |
1638 | sync_it |= S_CTIME; |
1639 | |
1640 | if (IS_I_VERSION(inode)) |
1641 | sync_it |= S_VERSION; |
1642 | |
1643 | if (!sync_it) |
1644 | return 0; |
1645 | |
1646 | /* Finally allowed to write? Takes lock. */ |
1647 | if (__mnt_want_write_file(file)) |
1648 | return 0; |
1649 | |
1650 | ret = update_time(inode, &now, sync_it); |
1651 | __mnt_drop_write_file(file); |
1652 | |
1653 | return ret; |
1654 | } |
1655 | EXPORT_SYMBOL(file_update_time); |
1656 | |
1657 | int inode_needs_sync(struct inode *inode) |
1658 | { |
1659 | if (IS_SYNC(inode)) |
1660 | return 1; |
1661 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) |
1662 | return 1; |
1663 | return 0; |
1664 | } |
1665 | EXPORT_SYMBOL(inode_needs_sync); |
1666 | |
1667 | int inode_wait(void *word) |
1668 | { |
1669 | schedule(); |
1670 | return 0; |
1671 | } |
1672 | EXPORT_SYMBOL(inode_wait); |
1673 | |
1674 | /* |
1675 | * If we try to find an inode in the inode hash while it is being |
1676 | * deleted, we have to wait until the filesystem completes its |
1677 | * deletion before reporting that it isn't found. This function waits |
1678 | * until the deletion _might_ have completed. Callers are responsible |
1679 | * to recheck inode state. |
1680 | * |
1681 | * It doesn't matter if I_NEW is not set initially, a call to |
1682 | * wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list |
1683 | * will DTRT. |
1684 | */ |
1685 | static void __wait_on_freeing_inode(struct inode *inode) |
1686 | { |
1687 | wait_queue_head_t *wq; |
1688 | DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); |
1689 | wq = bit_waitqueue(&inode->i_state, __I_NEW); |
1690 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); |
1691 | spin_unlock(&inode->i_lock); |
1692 | spin_unlock(&inode_hash_lock); |
1693 | schedule(); |
1694 | finish_wait(wq, &wait.wait); |
1695 | spin_lock(&inode_hash_lock); |
1696 | } |
1697 | |
1698 | static __initdata unsigned long ihash_entries; |
1699 | static int __init set_ihash_entries(char *str) |
1700 | { |
1701 | if (!str) |
1702 | return 0; |
1703 | ihash_entries = simple_strtoul(str, &str, 0); |
1704 | return 1; |
1705 | } |
1706 | __setup("ihash_entries=", set_ihash_entries); |
1707 | |
1708 | /* |
1709 | * Initialize the waitqueues and inode hash table. |
1710 | */ |
1711 | void __init inode_init_early(void) |
1712 | { |
1713 | unsigned int loop; |
1714 | |
1715 | /* If hashes are distributed across NUMA nodes, defer |
1716 | * hash allocation until vmalloc space is available. |
1717 | */ |
1718 | if (hashdist) |
1719 | return; |
1720 | |
1721 | inode_hashtable = |
1722 | alloc_large_system_hash("Inode-cache", |
1723 | sizeof(struct hlist_head), |
1724 | ihash_entries, |
1725 | 14, |
1726 | HASH_EARLY, |
1727 | &i_hash_shift, |
1728 | &i_hash_mask, |
1729 | 0, |
1730 | 0); |
1731 | |
1732 | for (loop = 0; loop < (1U << i_hash_shift); loop++) |
1733 | INIT_HLIST_HEAD(&inode_hashtable[loop]); |
1734 | } |
1735 | |
1736 | void __init inode_init(void) |
1737 | { |
1738 | unsigned int loop; |
1739 | |
1740 | /* inode slab cache */ |
1741 | inode_cachep = kmem_cache_create("inode_cache", |
1742 | sizeof(struct inode), |
1743 | 0, |
1744 | (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| |
1745 | SLAB_MEM_SPREAD), |
1746 | init_once); |
1747 | |
1748 | /* Hash may have been set up in inode_init_early */ |
1749 | if (!hashdist) |
1750 | return; |
1751 | |
1752 | inode_hashtable = |
1753 | alloc_large_system_hash("Inode-cache", |
1754 | sizeof(struct hlist_head), |
1755 | ihash_entries, |
1756 | 14, |
1757 | 0, |
1758 | &i_hash_shift, |
1759 | &i_hash_mask, |
1760 | 0, |
1761 | 0); |
1762 | |
1763 | for (loop = 0; loop < (1U << i_hash_shift); loop++) |
1764 | INIT_HLIST_HEAD(&inode_hashtable[loop]); |
1765 | } |
1766 | |
1767 | void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) |
1768 | { |
1769 | inode->i_mode = mode; |
1770 | if (S_ISCHR(mode)) { |
1771 | inode->i_fop = &def_chr_fops; |
1772 | inode->i_rdev = rdev; |
1773 | } else if (S_ISBLK(mode)) { |
1774 | inode->i_fop = &def_blk_fops; |
1775 | inode->i_rdev = rdev; |
1776 | } else if (S_ISFIFO(mode)) |
1777 | inode->i_fop = &pipefifo_fops; |
1778 | else if (S_ISSOCK(mode)) |
1779 | inode->i_fop = &bad_sock_fops; |
1780 | else |
1781 | printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for" |
1782 | " inode %s:%lu\n", mode, inode->i_sb->s_id, |
1783 | inode->i_ino); |
1784 | } |
1785 | EXPORT_SYMBOL(init_special_inode); |
1786 | |
1787 | /** |
1788 | * inode_init_owner - Init uid,gid,mode for new inode according to posix standards |
1789 | * @inode: New inode |
1790 | * @dir: Directory inode |
1791 | * @mode: mode of the new inode |
1792 | */ |
1793 | void inode_init_owner(struct inode *inode, const struct inode *dir, |
1794 | umode_t mode) |
1795 | { |
1796 | inode->i_uid = current_fsuid(); |
1797 | if (dir && dir->i_mode & S_ISGID) { |
1798 | inode->i_gid = dir->i_gid; |
1799 | if (S_ISDIR(mode)) |
1800 | mode |= S_ISGID; |
1801 | } else |
1802 | inode->i_gid = current_fsgid(); |
1803 | inode->i_mode = mode; |
1804 | } |
1805 | EXPORT_SYMBOL(inode_init_owner); |
1806 | |
1807 | /** |
1808 | * inode_owner_or_capable - check current task permissions to inode |
1809 | * @inode: inode being checked |
1810 | * |
1811 | * Return true if current either has CAP_FOWNER to the inode, or |
1812 | * owns the file. |
1813 | */ |
1814 | bool inode_owner_or_capable(const struct inode *inode) |
1815 | { |
1816 | if (uid_eq(current_fsuid(), inode->i_uid)) |
1817 | return true; |
1818 | if (inode_capable(inode, CAP_FOWNER)) |
1819 | return true; |
1820 | return false; |
1821 | } |
1822 | EXPORT_SYMBOL(inode_owner_or_capable); |
1823 | |
1824 | /* |
1825 | * Direct i/o helper functions |
1826 | */ |
1827 | static void __inode_dio_wait(struct inode *inode) |
1828 | { |
1829 | wait_queue_head_t *wq = bit_waitqueue(&inode->i_state, __I_DIO_WAKEUP); |
1830 | DEFINE_WAIT_BIT(q, &inode->i_state, __I_DIO_WAKEUP); |
1831 | |
1832 | do { |
1833 | prepare_to_wait(wq, &q.wait, TASK_UNINTERRUPTIBLE); |
1834 | if (atomic_read(&inode->i_dio_count)) |
1835 | schedule(); |
1836 | } while (atomic_read(&inode->i_dio_count)); |
1837 | finish_wait(wq, &q.wait); |
1838 | } |
1839 | |
1840 | /** |
1841 | * inode_dio_wait - wait for outstanding DIO requests to finish |
1842 | * @inode: inode to wait for |
1843 | * |
1844 | * Waits for all pending direct I/O requests to finish so that we can |
1845 | * proceed with a truncate or equivalent operation. |
1846 | * |
1847 | * Must be called under a lock that serializes taking new references |
1848 | * to i_dio_count, usually by inode->i_mutex. |
1849 | */ |
1850 | void inode_dio_wait(struct inode *inode) |
1851 | { |
1852 | if (atomic_read(&inode->i_dio_count)) |
1853 | __inode_dio_wait(inode); |
1854 | } |
1855 | EXPORT_SYMBOL(inode_dio_wait); |
1856 | |
1857 | /* |
1858 | * inode_dio_done - signal finish of a direct I/O requests |
1859 | * @inode: inode the direct I/O happens on |
1860 | * |
1861 | * This is called once we've finished processing a direct I/O request, |
1862 | * and is used to wake up callers waiting for direct I/O to be quiesced. |
1863 | */ |
1864 | void inode_dio_done(struct inode *inode) |
1865 | { |
1866 | if (atomic_dec_and_test(&inode->i_dio_count)) |
1867 | wake_up_bit(&inode->i_state, __I_DIO_WAKEUP); |
1868 | } |
1869 | EXPORT_SYMBOL(inode_dio_done); |
1870 |
Branches:
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javiroman/ks7010
jz-2.6.34
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9