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Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/inode.c | |
3 | * | |
4 | * (C) 1997 Linus Torvalds | |
5 | */ | |
6 | ||
1da177e4 LT |
7 | #include <linux/fs.h> |
8 | #include <linux/mm.h> | |
9 | #include <linux/dcache.h> | |
10 | #include <linux/init.h> | |
1da177e4 LT |
11 | #include <linux/slab.h> |
12 | #include <linux/writeback.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/backing-dev.h> | |
15 | #include <linux/wait.h> | |
88e0fbc4 | 16 | #include <linux/rwsem.h> |
1da177e4 LT |
17 | #include <linux/hash.h> |
18 | #include <linux/swap.h> | |
19 | #include <linux/security.h> | |
20 | #include <linux/pagemap.h> | |
21 | #include <linux/cdev.h> | |
22 | #include <linux/bootmem.h> | |
3be25f49 | 23 | #include <linux/fsnotify.h> |
fc33a7bb | 24 | #include <linux/mount.h> |
efaee192 | 25 | #include <linux/async.h> |
f19d4a8f | 26 | #include <linux/posix_acl.h> |
a178d202 | 27 | #include <linux/ima.h> |
1da177e4 LT |
28 | |
29 | /* | |
30 | * This is needed for the following functions: | |
31 | * - inode_has_buffers | |
32 | * - invalidate_inode_buffers | |
1da177e4 LT |
33 | * - invalidate_bdev |
34 | * | |
35 | * FIXME: remove all knowledge of the buffer layer from this file | |
36 | */ | |
37 | #include <linux/buffer_head.h> | |
38 | ||
39 | /* | |
40 | * New inode.c implementation. | |
41 | * | |
42 | * This implementation has the basic premise of trying | |
43 | * to be extremely low-overhead and SMP-safe, yet be | |
44 | * simple enough to be "obviously correct". | |
45 | * | |
46 | * Famous last words. | |
47 | */ | |
48 | ||
49 | /* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */ | |
50 | ||
51 | /* #define INODE_PARANOIA 1 */ | |
52 | /* #define INODE_DEBUG 1 */ | |
53 | ||
54 | /* | |
55 | * Inode lookup is no longer as critical as it used to be: | |
56 | * most of the lookups are going to be through the dcache. | |
57 | */ | |
58 | #define I_HASHBITS i_hash_shift | |
59 | #define I_HASHMASK i_hash_mask | |
60 | ||
fa3536cc ED |
61 | static unsigned int i_hash_mask __read_mostly; |
62 | static unsigned int i_hash_shift __read_mostly; | |
1da177e4 LT |
63 | |
64 | /* | |
65 | * Each inode can be on two separate lists. One is | |
66 | * the hash list of the inode, used for lookups. The | |
67 | * other linked list is the "type" list: | |
68 | * "in_use" - valid inode, i_count > 0, i_nlink > 0 | |
69 | * "dirty" - as "in_use" but also dirty | |
70 | * "unused" - valid inode, i_count = 0 | |
71 | * | |
72 | * A "dirty" list is maintained for each super block, | |
73 | * allowing for low-overhead inode sync() operations. | |
74 | */ | |
75 | ||
76 | LIST_HEAD(inode_in_use); | |
77 | LIST_HEAD(inode_unused); | |
fa3536cc | 78 | static struct hlist_head *inode_hashtable __read_mostly; |
1da177e4 LT |
79 | |
80 | /* | |
81 | * A simple spinlock to protect the list manipulations. | |
82 | * | |
83 | * NOTE! You also have to own the lock if you change | |
84 | * the i_state of an inode while it is in use.. | |
85 | */ | |
86 | DEFINE_SPINLOCK(inode_lock); | |
87 | ||
88 | /* | |
88e0fbc4 | 89 | * iprune_sem provides exclusion between the kswapd or try_to_free_pages |
1da177e4 LT |
90 | * icache shrinking path, and the umount path. Without this exclusion, |
91 | * by the time prune_icache calls iput for the inode whose pages it has | |
92 | * been invalidating, or by the time it calls clear_inode & destroy_inode | |
93 | * from its final dispose_list, the struct super_block they refer to | |
94 | * (for inode->i_sb->s_op) may already have been freed and reused. | |
88e0fbc4 NP |
95 | * |
96 | * We make this an rwsem because the fastpath is icache shrinking. In | |
97 | * some cases a filesystem may be doing a significant amount of work in | |
98 | * its inode reclaim code, so this should improve parallelism. | |
1da177e4 | 99 | */ |
88e0fbc4 | 100 | static DECLARE_RWSEM(iprune_sem); |
1da177e4 LT |
101 | |
102 | /* | |
103 | * Statistics gathering.. | |
104 | */ | |
105 | struct inodes_stat_t inodes_stat; | |
106 | ||
6b3304b5 | 107 | static struct kmem_cache *inode_cachep __read_mostly; |
1da177e4 | 108 | |
1c0eeaf5 JE |
109 | static void wake_up_inode(struct inode *inode) |
110 | { | |
111 | /* | |
112 | * Prevent speculative execution through spin_unlock(&inode_lock); | |
113 | */ | |
114 | smp_mb(); | |
eaff8079 | 115 | wake_up_bit(&inode->i_state, __I_NEW); |
1c0eeaf5 JE |
116 | } |
117 | ||
2cb1599f DC |
118 | /** |
119 | * inode_init_always - perform inode structure intialisation | |
0bc02f3f RD |
120 | * @sb: superblock inode belongs to |
121 | * @inode: inode to initialise | |
2cb1599f DC |
122 | * |
123 | * These are initializations that need to be done on every inode | |
124 | * allocation as the fields are not initialised by slab allocation. | |
125 | */ | |
54e34621 | 126 | int inode_init_always(struct super_block *sb, struct inode *inode) |
1da177e4 | 127 | { |
f5e54d6e | 128 | static const struct address_space_operations empty_aops; |
6e1d5dcc | 129 | static const struct inode_operations empty_iops; |
99ac48f5 | 130 | static const struct file_operations empty_fops; |
6b3304b5 | 131 | struct address_space *const mapping = &inode->i_data; |
2cb1599f DC |
132 | |
133 | inode->i_sb = sb; | |
134 | inode->i_blkbits = sb->s_blocksize_bits; | |
135 | inode->i_flags = 0; | |
136 | atomic_set(&inode->i_count, 1); | |
137 | inode->i_op = &empty_iops; | |
138 | inode->i_fop = &empty_fops; | |
139 | inode->i_nlink = 1; | |
56ff5efa AV |
140 | inode->i_uid = 0; |
141 | inode->i_gid = 0; | |
2cb1599f DC |
142 | atomic_set(&inode->i_writecount, 0); |
143 | inode->i_size = 0; | |
144 | inode->i_blocks = 0; | |
145 | inode->i_bytes = 0; | |
146 | inode->i_generation = 0; | |
1da177e4 | 147 | #ifdef CONFIG_QUOTA |
2cb1599f | 148 | memset(&inode->i_dquot, 0, sizeof(inode->i_dquot)); |
1da177e4 | 149 | #endif |
2cb1599f DC |
150 | inode->i_pipe = NULL; |
151 | inode->i_bdev = NULL; | |
152 | inode->i_cdev = NULL; | |
153 | inode->i_rdev = 0; | |
154 | inode->dirtied_when = 0; | |
6146f0d5 MZ |
155 | |
156 | if (security_inode_alloc(inode)) | |
54e34621 | 157 | goto out; |
2cb1599f DC |
158 | spin_lock_init(&inode->i_lock); |
159 | lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key); | |
160 | ||
161 | mutex_init(&inode->i_mutex); | |
162 | lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key); | |
163 | ||
164 | init_rwsem(&inode->i_alloc_sem); | |
165 | lockdep_set_class(&inode->i_alloc_sem, &sb->s_type->i_alloc_sem_key); | |
166 | ||
167 | mapping->a_ops = &empty_aops; | |
168 | mapping->host = inode; | |
169 | mapping->flags = 0; | |
3c1d4378 | 170 | mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE); |
2cb1599f DC |
171 | mapping->assoc_mapping = NULL; |
172 | mapping->backing_dev_info = &default_backing_dev_info; | |
173 | mapping->writeback_index = 0; | |
174 | ||
175 | /* | |
176 | * If the block_device provides a backing_dev_info for client | |
177 | * inodes then use that. Otherwise the inode share the bdev's | |
178 | * backing_dev_info. | |
179 | */ | |
180 | if (sb->s_bdev) { | |
181 | struct backing_dev_info *bdi; | |
182 | ||
2c96ce9f | 183 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; |
2cb1599f DC |
184 | mapping->backing_dev_info = bdi; |
185 | } | |
186 | inode->i_private = NULL; | |
187 | inode->i_mapping = mapping; | |
f19d4a8f AV |
188 | #ifdef CONFIG_FS_POSIX_ACL |
189 | inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; | |
190 | #endif | |
2cb1599f | 191 | |
3be25f49 EP |
192 | #ifdef CONFIG_FSNOTIFY |
193 | inode->i_fsnotify_mask = 0; | |
194 | #endif | |
195 | ||
54e34621 | 196 | return 0; |
54e34621 CH |
197 | out: |
198 | return -ENOMEM; | |
1da177e4 | 199 | } |
2cb1599f DC |
200 | EXPORT_SYMBOL(inode_init_always); |
201 | ||
202 | static struct inode *alloc_inode(struct super_block *sb) | |
203 | { | |
204 | struct inode *inode; | |
205 | ||
206 | if (sb->s_op->alloc_inode) | |
207 | inode = sb->s_op->alloc_inode(sb); | |
208 | else | |
209 | inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL); | |
210 | ||
54e34621 CH |
211 | if (!inode) |
212 | return NULL; | |
213 | ||
214 | if (unlikely(inode_init_always(sb, inode))) { | |
215 | if (inode->i_sb->s_op->destroy_inode) | |
216 | inode->i_sb->s_op->destroy_inode(inode); | |
217 | else | |
218 | kmem_cache_free(inode_cachep, inode); | |
219 | return NULL; | |
220 | } | |
221 | ||
222 | return inode; | |
2cb1599f | 223 | } |
1da177e4 | 224 | |
2e00c97e | 225 | void __destroy_inode(struct inode *inode) |
1da177e4 | 226 | { |
b7542f8c | 227 | BUG_ON(inode_has_buffers(inode)); |
1da177e4 | 228 | security_inode_free(inode); |
3be25f49 | 229 | fsnotify_inode_delete(inode); |
f19d4a8f AV |
230 | #ifdef CONFIG_FS_POSIX_ACL |
231 | if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED) | |
232 | posix_acl_release(inode->i_acl); | |
233 | if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) | |
234 | posix_acl_release(inode->i_default_acl); | |
235 | #endif | |
2e00c97e CH |
236 | } |
237 | EXPORT_SYMBOL(__destroy_inode); | |
238 | ||
239 | void destroy_inode(struct inode *inode) | |
240 | { | |
241 | __destroy_inode(inode); | |
1da177e4 LT |
242 | if (inode->i_sb->s_op->destroy_inode) |
243 | inode->i_sb->s_op->destroy_inode(inode); | |
244 | else | |
245 | kmem_cache_free(inode_cachep, (inode)); | |
246 | } | |
1da177e4 LT |
247 | |
248 | /* | |
249 | * These are initializations that only need to be done | |
250 | * once, because the fields are idempotent across use | |
251 | * of the inode, so let the slab aware of that. | |
252 | */ | |
253 | void inode_init_once(struct inode *inode) | |
254 | { | |
255 | memset(inode, 0, sizeof(*inode)); | |
256 | INIT_HLIST_NODE(&inode->i_hash); | |
257 | INIT_LIST_HEAD(&inode->i_dentry); | |
258 | INIT_LIST_HEAD(&inode->i_devices); | |
1da177e4 | 259 | INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); |
19fd6231 | 260 | spin_lock_init(&inode->i_data.tree_lock); |
1da177e4 LT |
261 | spin_lock_init(&inode->i_data.i_mmap_lock); |
262 | INIT_LIST_HEAD(&inode->i_data.private_list); | |
263 | spin_lock_init(&inode->i_data.private_lock); | |
264 | INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap); | |
265 | INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); | |
1da177e4 | 266 | i_size_ordered_init(inode); |
3be25f49 | 267 | #ifdef CONFIG_FSNOTIFY |
e61ce867 | 268 | INIT_HLIST_HEAD(&inode->i_fsnotify_marks); |
3be25f49 | 269 | #endif |
1da177e4 | 270 | } |
1da177e4 LT |
271 | EXPORT_SYMBOL(inode_init_once); |
272 | ||
51cc5068 | 273 | static void init_once(void *foo) |
1da177e4 | 274 | { |
6b3304b5 | 275 | struct inode *inode = (struct inode *) foo; |
1da177e4 | 276 | |
a35afb83 | 277 | inode_init_once(inode); |
1da177e4 LT |
278 | } |
279 | ||
280 | /* | |
281 | * inode_lock must be held | |
282 | */ | |
6b3304b5 | 283 | void __iget(struct inode *inode) |
1da177e4 | 284 | { |
2e147f1e | 285 | if (atomic_inc_return(&inode->i_count) != 1) |
1da177e4 | 286 | return; |
2e147f1e | 287 | |
1c0eeaf5 | 288 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) |
1da177e4 LT |
289 | list_move(&inode->i_list, &inode_in_use); |
290 | inodes_stat.nr_unused--; | |
291 | } | |
292 | ||
b0683aa6 AV |
293 | void end_writeback(struct inode *inode) |
294 | { | |
295 | might_sleep(); | |
296 | BUG_ON(inode->i_data.nrpages); | |
297 | BUG_ON(!list_empty(&inode->i_data.private_list)); | |
298 | BUG_ON(!(inode->i_state & I_FREEING)); | |
299 | BUG_ON(inode->i_state & I_CLEAR); | |
300 | inode_sync_wait(inode); | |
301 | inode->i_state = I_FREEING | I_CLEAR; | |
302 | } | |
303 | EXPORT_SYMBOL(end_writeback); | |
304 | ||
644da596 | 305 | static void evict(struct inode *inode) |
b4272d4c AV |
306 | { |
307 | const struct super_operations *op = inode->i_sb->s_op; | |
308 | ||
be7ce416 AV |
309 | if (op->evict_inode) { |
310 | op->evict_inode(inode); | |
b4272d4c AV |
311 | } else { |
312 | if (inode->i_data.nrpages) | |
313 | truncate_inode_pages(&inode->i_data, 0); | |
30140837 | 314 | end_writeback(inode); |
b4272d4c | 315 | } |
661074e9 AV |
316 | if (S_ISBLK(inode->i_mode) && inode->i_bdev) |
317 | bd_forget(inode); | |
318 | if (S_ISCHR(inode->i_mode) && inode->i_cdev) | |
319 | cd_forget(inode); | |
b4272d4c AV |
320 | } |
321 | ||
1da177e4 LT |
322 | /* |
323 | * dispose_list - dispose of the contents of a local list | |
324 | * @head: the head of the list to free | |
325 | * | |
326 | * Dispose-list gets a local list with local inodes in it, so it doesn't | |
327 | * need to worry about list corruption and SMP locks. | |
328 | */ | |
329 | static void dispose_list(struct list_head *head) | |
330 | { | |
331 | int nr_disposed = 0; | |
332 | ||
333 | while (!list_empty(head)) { | |
334 | struct inode *inode; | |
335 | ||
b5e61818 | 336 | inode = list_first_entry(head, struct inode, i_list); |
1da177e4 LT |
337 | list_del(&inode->i_list); |
338 | ||
644da596 | 339 | evict(inode); |
4120db47 AB |
340 | |
341 | spin_lock(&inode_lock); | |
342 | hlist_del_init(&inode->i_hash); | |
343 | list_del_init(&inode->i_sb_list); | |
344 | spin_unlock(&inode_lock); | |
345 | ||
346 | wake_up_inode(inode); | |
1da177e4 LT |
347 | destroy_inode(inode); |
348 | nr_disposed++; | |
349 | } | |
350 | spin_lock(&inode_lock); | |
351 | inodes_stat.nr_inodes -= nr_disposed; | |
352 | spin_unlock(&inode_lock); | |
353 | } | |
354 | ||
355 | /* | |
356 | * Invalidate all inodes for a device. | |
357 | */ | |
358 | static int invalidate_list(struct list_head *head, struct list_head *dispose) | |
359 | { | |
360 | struct list_head *next; | |
361 | int busy = 0, count = 0; | |
362 | ||
363 | next = head->next; | |
364 | for (;;) { | |
6b3304b5 MK |
365 | struct list_head *tmp = next; |
366 | struct inode *inode; | |
1da177e4 LT |
367 | |
368 | /* | |
369 | * We can reschedule here without worrying about the list's | |
370 | * consistency because the per-sb list of inodes must not | |
88e0fbc4 | 371 | * change during umount anymore, and because iprune_sem keeps |
1da177e4 LT |
372 | * shrink_icache_memory() away. |
373 | */ | |
374 | cond_resched_lock(&inode_lock); | |
375 | ||
376 | next = next->next; | |
377 | if (tmp == head) | |
378 | break; | |
379 | inode = list_entry(tmp, struct inode, i_sb_list); | |
aabb8fdb NP |
380 | if (inode->i_state & I_NEW) |
381 | continue; | |
1da177e4 LT |
382 | invalidate_inode_buffers(inode); |
383 | if (!atomic_read(&inode->i_count)) { | |
1da177e4 | 384 | list_move(&inode->i_list, dispose); |
7ef0d737 | 385 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 LT |
386 | inode->i_state |= I_FREEING; |
387 | count++; | |
388 | continue; | |
389 | } | |
390 | busy = 1; | |
391 | } | |
392 | /* only unused inodes may be cached with i_count zero */ | |
393 | inodes_stat.nr_unused -= count; | |
394 | return busy; | |
395 | } | |
396 | ||
1da177e4 LT |
397 | /** |
398 | * invalidate_inodes - discard the inodes on a device | |
399 | * @sb: superblock | |
400 | * | |
401 | * Discard all of the inodes for a given superblock. If the discard | |
402 | * fails because there are busy inodes then a non zero value is returned. | |
403 | * If the discard is successful all the inodes have been discarded. | |
404 | */ | |
6b3304b5 | 405 | int invalidate_inodes(struct super_block *sb) |
1da177e4 LT |
406 | { |
407 | int busy; | |
408 | LIST_HEAD(throw_away); | |
409 | ||
88e0fbc4 | 410 | down_write(&iprune_sem); |
1da177e4 | 411 | spin_lock(&inode_lock); |
164bc619 | 412 | fsnotify_unmount_inodes(&sb->s_inodes); |
1da177e4 LT |
413 | busy = invalidate_list(&sb->s_inodes, &throw_away); |
414 | spin_unlock(&inode_lock); | |
415 | ||
416 | dispose_list(&throw_away); | |
88e0fbc4 | 417 | up_write(&iprune_sem); |
1da177e4 LT |
418 | |
419 | return busy; | |
420 | } | |
1da177e4 | 421 | EXPORT_SYMBOL(invalidate_inodes); |
1da177e4 LT |
422 | |
423 | static int can_unuse(struct inode *inode) | |
424 | { | |
425 | if (inode->i_state) | |
426 | return 0; | |
427 | if (inode_has_buffers(inode)) | |
428 | return 0; | |
429 | if (atomic_read(&inode->i_count)) | |
430 | return 0; | |
431 | if (inode->i_data.nrpages) | |
432 | return 0; | |
433 | return 1; | |
434 | } | |
435 | ||
436 | /* | |
437 | * Scan `goal' inodes on the unused list for freeable ones. They are moved to | |
438 | * a temporary list and then are freed outside inode_lock by dispose_list(). | |
439 | * | |
440 | * Any inodes which are pinned purely because of attached pagecache have their | |
441 | * pagecache removed. We expect the final iput() on that inode to add it to | |
442 | * the front of the inode_unused list. So look for it there and if the | |
443 | * inode is still freeable, proceed. The right inode is found 99.9% of the | |
444 | * time in testing on a 4-way. | |
445 | * | |
446 | * If the inode has metadata buffers attached to mapping->private_list then | |
447 | * try to remove them. | |
448 | */ | |
449 | static void prune_icache(int nr_to_scan) | |
450 | { | |
451 | LIST_HEAD(freeable); | |
452 | int nr_pruned = 0; | |
453 | int nr_scanned; | |
454 | unsigned long reap = 0; | |
455 | ||
88e0fbc4 | 456 | down_read(&iprune_sem); |
1da177e4 LT |
457 | spin_lock(&inode_lock); |
458 | for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { | |
459 | struct inode *inode; | |
460 | ||
461 | if (list_empty(&inode_unused)) | |
462 | break; | |
463 | ||
464 | inode = list_entry(inode_unused.prev, struct inode, i_list); | |
465 | ||
466 | if (inode->i_state || atomic_read(&inode->i_count)) { | |
467 | list_move(&inode->i_list, &inode_unused); | |
468 | continue; | |
469 | } | |
470 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { | |
471 | __iget(inode); | |
472 | spin_unlock(&inode_lock); | |
473 | if (remove_inode_buffers(inode)) | |
fc0ecff6 AM |
474 | reap += invalidate_mapping_pages(&inode->i_data, |
475 | 0, -1); | |
1da177e4 LT |
476 | iput(inode); |
477 | spin_lock(&inode_lock); | |
478 | ||
479 | if (inode != list_entry(inode_unused.next, | |
480 | struct inode, i_list)) | |
481 | continue; /* wrong inode or list_empty */ | |
482 | if (!can_unuse(inode)) | |
483 | continue; | |
484 | } | |
1da177e4 | 485 | list_move(&inode->i_list, &freeable); |
7ef0d737 | 486 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 LT |
487 | inode->i_state |= I_FREEING; |
488 | nr_pruned++; | |
489 | } | |
490 | inodes_stat.nr_unused -= nr_pruned; | |
f8891e5e CL |
491 | if (current_is_kswapd()) |
492 | __count_vm_events(KSWAPD_INODESTEAL, reap); | |
493 | else | |
494 | __count_vm_events(PGINODESTEAL, reap); | |
1da177e4 LT |
495 | spin_unlock(&inode_lock); |
496 | ||
497 | dispose_list(&freeable); | |
88e0fbc4 | 498 | up_read(&iprune_sem); |
1da177e4 LT |
499 | } |
500 | ||
501 | /* | |
502 | * shrink_icache_memory() will attempt to reclaim some unused inodes. Here, | |
503 | * "unused" means that no dentries are referring to the inodes: the files are | |
504 | * not open and the dcache references to those inodes have already been | |
505 | * reclaimed. | |
506 | * | |
507 | * This function is passed the number of inodes to scan, and it returns the | |
508 | * total number of remaining possibly-reclaimable inodes. | |
509 | */ | |
7f8275d0 | 510 | static int shrink_icache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask) |
1da177e4 LT |
511 | { |
512 | if (nr) { | |
513 | /* | |
514 | * Nasty deadlock avoidance. We may hold various FS locks, | |
515 | * and we don't want to recurse into the FS that called us | |
516 | * in clear_inode() and friends.. | |
6b3304b5 | 517 | */ |
1da177e4 LT |
518 | if (!(gfp_mask & __GFP_FS)) |
519 | return -1; | |
520 | prune_icache(nr); | |
521 | } | |
522 | return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure; | |
523 | } | |
524 | ||
8e1f936b RR |
525 | static struct shrinker icache_shrinker = { |
526 | .shrink = shrink_icache_memory, | |
527 | .seeks = DEFAULT_SEEKS, | |
528 | }; | |
529 | ||
1da177e4 LT |
530 | static void __wait_on_freeing_inode(struct inode *inode); |
531 | /* | |
532 | * Called with the inode lock held. | |
533 | * NOTE: we are not increasing the inode-refcount, you must call __iget() | |
534 | * by hand after calling find_inode now! This simplifies iunique and won't | |
535 | * add any additional branch in the common code. | |
536 | */ | |
6b3304b5 MK |
537 | static struct inode *find_inode(struct super_block *sb, |
538 | struct hlist_head *head, | |
539 | int (*test)(struct inode *, void *), | |
540 | void *data) | |
1da177e4 LT |
541 | { |
542 | struct hlist_node *node; | |
6b3304b5 | 543 | struct inode *inode = NULL; |
1da177e4 LT |
544 | |
545 | repeat: | |
c5c8be3c | 546 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
547 | if (inode->i_sb != sb) |
548 | continue; | |
549 | if (!test(inode, data)) | |
550 | continue; | |
a4ffdde6 | 551 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
1da177e4 LT |
552 | __wait_on_freeing_inode(inode); |
553 | goto repeat; | |
554 | } | |
555 | break; | |
556 | } | |
557 | return node ? inode : NULL; | |
558 | } | |
559 | ||
560 | /* | |
561 | * find_inode_fast is the fast path version of find_inode, see the comment at | |
562 | * iget_locked for details. | |
563 | */ | |
6b3304b5 MK |
564 | static struct inode *find_inode_fast(struct super_block *sb, |
565 | struct hlist_head *head, unsigned long ino) | |
1da177e4 LT |
566 | { |
567 | struct hlist_node *node; | |
6b3304b5 | 568 | struct inode *inode = NULL; |
1da177e4 LT |
569 | |
570 | repeat: | |
c5c8be3c | 571 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
572 | if (inode->i_ino != ino) |
573 | continue; | |
574 | if (inode->i_sb != sb) | |
575 | continue; | |
a4ffdde6 | 576 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
1da177e4 LT |
577 | __wait_on_freeing_inode(inode); |
578 | goto repeat; | |
579 | } | |
580 | break; | |
581 | } | |
582 | return node ? inode : NULL; | |
583 | } | |
584 | ||
8290c35f DC |
585 | static unsigned long hash(struct super_block *sb, unsigned long hashval) |
586 | { | |
587 | unsigned long tmp; | |
588 | ||
589 | tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / | |
590 | L1_CACHE_BYTES; | |
591 | tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS); | |
592 | return tmp & I_HASHMASK; | |
593 | } | |
594 | ||
595 | static inline void | |
596 | __inode_add_to_lists(struct super_block *sb, struct hlist_head *head, | |
597 | struct inode *inode) | |
598 | { | |
599 | inodes_stat.nr_inodes++; | |
600 | list_add(&inode->i_list, &inode_in_use); | |
601 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
602 | if (head) | |
603 | hlist_add_head(&inode->i_hash, head); | |
604 | } | |
605 | ||
606 | /** | |
607 | * inode_add_to_lists - add a new inode to relevant lists | |
0bc02f3f RD |
608 | * @sb: superblock inode belongs to |
609 | * @inode: inode to mark in use | |
8290c35f DC |
610 | * |
611 | * When an inode is allocated it needs to be accounted for, added to the in use | |
612 | * list, the owning superblock and the inode hash. This needs to be done under | |
613 | * the inode_lock, so export a function to do this rather than the inode lock | |
614 | * itself. We calculate the hash list to add to here so it is all internal | |
615 | * which requires the caller to have already set up the inode number in the | |
616 | * inode to add. | |
617 | */ | |
618 | void inode_add_to_lists(struct super_block *sb, struct inode *inode) | |
619 | { | |
620 | struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino); | |
621 | ||
622 | spin_lock(&inode_lock); | |
623 | __inode_add_to_lists(sb, head, inode); | |
624 | spin_unlock(&inode_lock); | |
625 | } | |
626 | EXPORT_SYMBOL_GPL(inode_add_to_lists); | |
627 | ||
1da177e4 LT |
628 | /** |
629 | * new_inode - obtain an inode | |
630 | * @sb: superblock | |
631 | * | |
769848c0 | 632 | * Allocates a new inode for given superblock. The default gfp_mask |
3c1d4378 | 633 | * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE. |
769848c0 MG |
634 | * If HIGHMEM pages are unsuitable or it is known that pages allocated |
635 | * for the page cache are not reclaimable or migratable, | |
636 | * mapping_set_gfp_mask() must be called with suitable flags on the | |
637 | * newly created inode's mapping | |
638 | * | |
1da177e4 LT |
639 | */ |
640 | struct inode *new_inode(struct super_block *sb) | |
641 | { | |
866b04fc JL |
642 | /* |
643 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
644 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
645 | * here to attempt to avoid that. | |
646 | */ | |
647 | static unsigned int last_ino; | |
6b3304b5 | 648 | struct inode *inode; |
1da177e4 LT |
649 | |
650 | spin_lock_prefetch(&inode_lock); | |
6b3304b5 | 651 | |
1da177e4 LT |
652 | inode = alloc_inode(sb); |
653 | if (inode) { | |
654 | spin_lock(&inode_lock); | |
8290c35f | 655 | __inode_add_to_lists(sb, NULL, inode); |
1da177e4 LT |
656 | inode->i_ino = ++last_ino; |
657 | inode->i_state = 0; | |
658 | spin_unlock(&inode_lock); | |
659 | } | |
660 | return inode; | |
661 | } | |
1da177e4 LT |
662 | EXPORT_SYMBOL(new_inode); |
663 | ||
664 | void unlock_new_inode(struct inode *inode) | |
665 | { | |
14358e6d | 666 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
1e89a5e1 PZ |
667 | if (inode->i_mode & S_IFDIR) { |
668 | struct file_system_type *type = inode->i_sb->s_type; | |
669 | ||
9a7aa12f JK |
670 | /* Set new key only if filesystem hasn't already changed it */ |
671 | if (!lockdep_match_class(&inode->i_mutex, | |
672 | &type->i_mutex_key)) { | |
673 | /* | |
674 | * ensure nobody is actually holding i_mutex | |
675 | */ | |
676 | mutex_destroy(&inode->i_mutex); | |
677 | mutex_init(&inode->i_mutex); | |
678 | lockdep_set_class(&inode->i_mutex, | |
679 | &type->i_mutex_dir_key); | |
680 | } | |
1e89a5e1 | 681 | } |
14358e6d | 682 | #endif |
1da177e4 | 683 | /* |
eaff8079 | 684 | * This is special! We do not need the spinlock when clearing I_NEW, |
580be083 JK |
685 | * because we're guaranteed that nobody else tries to do anything about |
686 | * the state of the inode when it is locked, as we just created it (so | |
eaff8079 | 687 | * there can be no old holders that haven't tested I_NEW). |
580be083 | 688 | * However we must emit the memory barrier so that other CPUs reliably |
eaff8079 | 689 | * see the clearing of I_NEW after the other inode initialisation has |
580be083 | 690 | * completed. |
1da177e4 | 691 | */ |
580be083 | 692 | smp_mb(); |
eaff8079 CH |
693 | WARN_ON(!(inode->i_state & I_NEW)); |
694 | inode->i_state &= ~I_NEW; | |
1da177e4 LT |
695 | wake_up_inode(inode); |
696 | } | |
1da177e4 LT |
697 | EXPORT_SYMBOL(unlock_new_inode); |
698 | ||
699 | /* | |
700 | * This is called without the inode lock held.. Be careful. | |
701 | * | |
702 | * We no longer cache the sb_flags in i_flags - see fs.h | |
703 | * -- rmk@arm.uk.linux.org | |
704 | */ | |
6b3304b5 MK |
705 | static struct inode *get_new_inode(struct super_block *sb, |
706 | struct hlist_head *head, | |
707 | int (*test)(struct inode *, void *), | |
708 | int (*set)(struct inode *, void *), | |
709 | void *data) | |
1da177e4 | 710 | { |
6b3304b5 | 711 | struct inode *inode; |
1da177e4 LT |
712 | |
713 | inode = alloc_inode(sb); | |
714 | if (inode) { | |
6b3304b5 | 715 | struct inode *old; |
1da177e4 LT |
716 | |
717 | spin_lock(&inode_lock); | |
718 | /* We released the lock, so.. */ | |
719 | old = find_inode(sb, head, test, data); | |
720 | if (!old) { | |
721 | if (set(inode, data)) | |
722 | goto set_failed; | |
723 | ||
8290c35f | 724 | __inode_add_to_lists(sb, head, inode); |
eaff8079 | 725 | inode->i_state = I_NEW; |
1da177e4 LT |
726 | spin_unlock(&inode_lock); |
727 | ||
728 | /* Return the locked inode with I_NEW set, the | |
729 | * caller is responsible for filling in the contents | |
730 | */ | |
731 | return inode; | |
732 | } | |
733 | ||
734 | /* | |
735 | * Uhhuh, somebody else created the same inode under | |
736 | * us. Use the old inode instead of the one we just | |
737 | * allocated. | |
738 | */ | |
739 | __iget(old); | |
740 | spin_unlock(&inode_lock); | |
741 | destroy_inode(inode); | |
742 | inode = old; | |
743 | wait_on_inode(inode); | |
744 | } | |
745 | return inode; | |
746 | ||
747 | set_failed: | |
748 | spin_unlock(&inode_lock); | |
749 | destroy_inode(inode); | |
750 | return NULL; | |
751 | } | |
752 | ||
753 | /* | |
754 | * get_new_inode_fast is the fast path version of get_new_inode, see the | |
755 | * comment at iget_locked for details. | |
756 | */ | |
6b3304b5 MK |
757 | static struct inode *get_new_inode_fast(struct super_block *sb, |
758 | struct hlist_head *head, unsigned long ino) | |
1da177e4 | 759 | { |
6b3304b5 | 760 | struct inode *inode; |
1da177e4 LT |
761 | |
762 | inode = alloc_inode(sb); | |
763 | if (inode) { | |
6b3304b5 | 764 | struct inode *old; |
1da177e4 LT |
765 | |
766 | spin_lock(&inode_lock); | |
767 | /* We released the lock, so.. */ | |
768 | old = find_inode_fast(sb, head, ino); | |
769 | if (!old) { | |
770 | inode->i_ino = ino; | |
8290c35f | 771 | __inode_add_to_lists(sb, head, inode); |
eaff8079 | 772 | inode->i_state = I_NEW; |
1da177e4 LT |
773 | spin_unlock(&inode_lock); |
774 | ||
775 | /* Return the locked inode with I_NEW set, the | |
776 | * caller is responsible for filling in the contents | |
777 | */ | |
778 | return inode; | |
779 | } | |
780 | ||
781 | /* | |
782 | * Uhhuh, somebody else created the same inode under | |
783 | * us. Use the old inode instead of the one we just | |
784 | * allocated. | |
785 | */ | |
786 | __iget(old); | |
787 | spin_unlock(&inode_lock); | |
788 | destroy_inode(inode); | |
789 | inode = old; | |
790 | wait_on_inode(inode); | |
791 | } | |
792 | return inode; | |
793 | } | |
794 | ||
1da177e4 LT |
795 | /** |
796 | * iunique - get a unique inode number | |
797 | * @sb: superblock | |
798 | * @max_reserved: highest reserved inode number | |
799 | * | |
800 | * Obtain an inode number that is unique on the system for a given | |
801 | * superblock. This is used by file systems that have no natural | |
802 | * permanent inode numbering system. An inode number is returned that | |
803 | * is higher than the reserved limit but unique. | |
804 | * | |
805 | * BUGS: | |
806 | * With a large number of inodes live on the file system this function | |
807 | * currently becomes quite slow. | |
808 | */ | |
809 | ino_t iunique(struct super_block *sb, ino_t max_reserved) | |
810 | { | |
866b04fc JL |
811 | /* |
812 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
813 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
814 | * here to attempt to avoid that. | |
815 | */ | |
816 | static unsigned int counter; | |
1da177e4 | 817 | struct inode *inode; |
3361c7be | 818 | struct hlist_head *head; |
1da177e4 | 819 | ino_t res; |
3361c7be | 820 | |
1da177e4 | 821 | spin_lock(&inode_lock); |
3361c7be JL |
822 | do { |
823 | if (counter <= max_reserved) | |
824 | counter = max_reserved + 1; | |
1da177e4 | 825 | res = counter++; |
3361c7be | 826 | head = inode_hashtable + hash(sb, res); |
1da177e4 | 827 | inode = find_inode_fast(sb, head, res); |
3361c7be JL |
828 | } while (inode != NULL); |
829 | spin_unlock(&inode_lock); | |
1da177e4 | 830 | |
3361c7be JL |
831 | return res; |
832 | } | |
1da177e4 LT |
833 | EXPORT_SYMBOL(iunique); |
834 | ||
835 | struct inode *igrab(struct inode *inode) | |
836 | { | |
837 | spin_lock(&inode_lock); | |
a4ffdde6 | 838 | if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) |
1da177e4 LT |
839 | __iget(inode); |
840 | else | |
841 | /* | |
842 | * Handle the case where s_op->clear_inode is not been | |
843 | * called yet, and somebody is calling igrab | |
844 | * while the inode is getting freed. | |
845 | */ | |
846 | inode = NULL; | |
847 | spin_unlock(&inode_lock); | |
848 | return inode; | |
849 | } | |
1da177e4 LT |
850 | EXPORT_SYMBOL(igrab); |
851 | ||
852 | /** | |
853 | * ifind - internal function, you want ilookup5() or iget5(). | |
854 | * @sb: super block of file system to search | |
855 | * @head: the head of the list to search | |
856 | * @test: callback used for comparisons between inodes | |
857 | * @data: opaque data pointer to pass to @test | |
88bd5121 | 858 | * @wait: if true wait for the inode to be unlocked, if false do not |
1da177e4 LT |
859 | * |
860 | * ifind() searches for the inode specified by @data in the inode | |
861 | * cache. This is a generalized version of ifind_fast() for file systems where | |
862 | * the inode number is not sufficient for unique identification of an inode. | |
863 | * | |
864 | * If the inode is in the cache, the inode is returned with an incremented | |
865 | * reference count. | |
866 | * | |
867 | * Otherwise NULL is returned. | |
868 | * | |
869 | * Note, @test is called with the inode_lock held, so can't sleep. | |
870 | */ | |
5d2bea45 | 871 | static struct inode *ifind(struct super_block *sb, |
1da177e4 | 872 | struct hlist_head *head, int (*test)(struct inode *, void *), |
88bd5121 | 873 | void *data, const int wait) |
1da177e4 LT |
874 | { |
875 | struct inode *inode; | |
876 | ||
877 | spin_lock(&inode_lock); | |
878 | inode = find_inode(sb, head, test, data); | |
879 | if (inode) { | |
880 | __iget(inode); | |
881 | spin_unlock(&inode_lock); | |
88bd5121 AA |
882 | if (likely(wait)) |
883 | wait_on_inode(inode); | |
1da177e4 LT |
884 | return inode; |
885 | } | |
886 | spin_unlock(&inode_lock); | |
887 | return NULL; | |
888 | } | |
889 | ||
890 | /** | |
891 | * ifind_fast - internal function, you want ilookup() or iget(). | |
892 | * @sb: super block of file system to search | |
893 | * @head: head of the list to search | |
894 | * @ino: inode number to search for | |
895 | * | |
896 | * ifind_fast() searches for the inode @ino in the inode cache. This is for | |
897 | * file systems where the inode number is sufficient for unique identification | |
898 | * of an inode. | |
899 | * | |
900 | * If the inode is in the cache, the inode is returned with an incremented | |
901 | * reference count. | |
902 | * | |
903 | * Otherwise NULL is returned. | |
904 | */ | |
5d2bea45 | 905 | static struct inode *ifind_fast(struct super_block *sb, |
1da177e4 LT |
906 | struct hlist_head *head, unsigned long ino) |
907 | { | |
908 | struct inode *inode; | |
909 | ||
910 | spin_lock(&inode_lock); | |
911 | inode = find_inode_fast(sb, head, ino); | |
912 | if (inode) { | |
913 | __iget(inode); | |
914 | spin_unlock(&inode_lock); | |
915 | wait_on_inode(inode); | |
916 | return inode; | |
917 | } | |
918 | spin_unlock(&inode_lock); | |
919 | return NULL; | |
920 | } | |
921 | ||
922 | /** | |
88bd5121 | 923 | * ilookup5_nowait - search for an inode in the inode cache |
1da177e4 LT |
924 | * @sb: super block of file system to search |
925 | * @hashval: hash value (usually inode number) to search for | |
926 | * @test: callback used for comparisons between inodes | |
927 | * @data: opaque data pointer to pass to @test | |
928 | * | |
929 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
930 | * @data in the inode cache. This is a generalized version of ilookup() for | |
931 | * file systems where the inode number is not sufficient for unique | |
932 | * identification of an inode. | |
933 | * | |
934 | * If the inode is in the cache, the inode is returned with an incremented | |
88bd5121 AA |
935 | * reference count. Note, the inode lock is not waited upon so you have to be |
936 | * very careful what you do with the returned inode. You probably should be | |
937 | * using ilookup5() instead. | |
938 | * | |
939 | * Otherwise NULL is returned. | |
940 | * | |
941 | * Note, @test is called with the inode_lock held, so can't sleep. | |
942 | */ | |
943 | struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, | |
944 | int (*test)(struct inode *, void *), void *data) | |
945 | { | |
946 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
947 | ||
948 | return ifind(sb, head, test, data, 0); | |
949 | } | |
88bd5121 AA |
950 | EXPORT_SYMBOL(ilookup5_nowait); |
951 | ||
952 | /** | |
953 | * ilookup5 - search for an inode in the inode cache | |
954 | * @sb: super block of file system to search | |
955 | * @hashval: hash value (usually inode number) to search for | |
956 | * @test: callback used for comparisons between inodes | |
957 | * @data: opaque data pointer to pass to @test | |
958 | * | |
959 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
960 | * @data in the inode cache. This is a generalized version of ilookup() for | |
961 | * file systems where the inode number is not sufficient for unique | |
962 | * identification of an inode. | |
963 | * | |
964 | * If the inode is in the cache, the inode lock is waited upon and the inode is | |
965 | * returned with an incremented reference count. | |
1da177e4 LT |
966 | * |
967 | * Otherwise NULL is returned. | |
968 | * | |
969 | * Note, @test is called with the inode_lock held, so can't sleep. | |
970 | */ | |
971 | struct inode *ilookup5(struct super_block *sb, unsigned long hashval, | |
972 | int (*test)(struct inode *, void *), void *data) | |
973 | { | |
974 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
975 | ||
88bd5121 | 976 | return ifind(sb, head, test, data, 1); |
1da177e4 | 977 | } |
1da177e4 LT |
978 | EXPORT_SYMBOL(ilookup5); |
979 | ||
980 | /** | |
981 | * ilookup - search for an inode in the inode cache | |
982 | * @sb: super block of file system to search | |
983 | * @ino: inode number to search for | |
984 | * | |
985 | * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache. | |
986 | * This is for file systems where the inode number is sufficient for unique | |
987 | * identification of an inode. | |
988 | * | |
989 | * If the inode is in the cache, the inode is returned with an incremented | |
990 | * reference count. | |
991 | * | |
992 | * Otherwise NULL is returned. | |
993 | */ | |
994 | struct inode *ilookup(struct super_block *sb, unsigned long ino) | |
995 | { | |
996 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
997 | ||
998 | return ifind_fast(sb, head, ino); | |
999 | } | |
1da177e4 LT |
1000 | EXPORT_SYMBOL(ilookup); |
1001 | ||
1002 | /** | |
1003 | * iget5_locked - obtain an inode from a mounted file system | |
1004 | * @sb: super block of file system | |
1005 | * @hashval: hash value (usually inode number) to get | |
1006 | * @test: callback used for comparisons between inodes | |
1007 | * @set: callback used to initialize a new struct inode | |
1008 | * @data: opaque data pointer to pass to @test and @set | |
1009 | * | |
1da177e4 LT |
1010 | * iget5_locked() uses ifind() to search for the inode specified by @hashval |
1011 | * and @data in the inode cache and if present it is returned with an increased | |
1012 | * reference count. This is a generalized version of iget_locked() for file | |
1013 | * systems where the inode number is not sufficient for unique identification | |
1014 | * of an inode. | |
1015 | * | |
1016 | * If the inode is not in cache, get_new_inode() is called to allocate a new | |
1017 | * inode and this is returned locked, hashed, and with the I_NEW flag set. The | |
1018 | * file system gets to fill it in before unlocking it via unlock_new_inode(). | |
1019 | * | |
1020 | * Note both @test and @set are called with the inode_lock held, so can't sleep. | |
1021 | */ | |
1022 | struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, | |
1023 | int (*test)(struct inode *, void *), | |
1024 | int (*set)(struct inode *, void *), void *data) | |
1025 | { | |
1026 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
1027 | struct inode *inode; | |
1028 | ||
88bd5121 | 1029 | inode = ifind(sb, head, test, data, 1); |
1da177e4 LT |
1030 | if (inode) |
1031 | return inode; | |
1032 | /* | |
1033 | * get_new_inode() will do the right thing, re-trying the search | |
1034 | * in case it had to block at any point. | |
1035 | */ | |
1036 | return get_new_inode(sb, head, test, set, data); | |
1037 | } | |
1da177e4 LT |
1038 | EXPORT_SYMBOL(iget5_locked); |
1039 | ||
1040 | /** | |
1041 | * iget_locked - obtain an inode from a mounted file system | |
1042 | * @sb: super block of file system | |
1043 | * @ino: inode number to get | |
1044 | * | |
1da177e4 LT |
1045 | * iget_locked() uses ifind_fast() to search for the inode specified by @ino in |
1046 | * the inode cache and if present it is returned with an increased reference | |
1047 | * count. This is for file systems where the inode number is sufficient for | |
1048 | * unique identification of an inode. | |
1049 | * | |
1050 | * If the inode is not in cache, get_new_inode_fast() is called to allocate a | |
1051 | * new inode and this is returned locked, hashed, and with the I_NEW flag set. | |
1052 | * The file system gets to fill it in before unlocking it via | |
1053 | * unlock_new_inode(). | |
1054 | */ | |
1055 | struct inode *iget_locked(struct super_block *sb, unsigned long ino) | |
1056 | { | |
1057 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
1058 | struct inode *inode; | |
1059 | ||
1060 | inode = ifind_fast(sb, head, ino); | |
1061 | if (inode) | |
1062 | return inode; | |
1063 | /* | |
1064 | * get_new_inode_fast() will do the right thing, re-trying the search | |
1065 | * in case it had to block at any point. | |
1066 | */ | |
1067 | return get_new_inode_fast(sb, head, ino); | |
1068 | } | |
1da177e4 LT |
1069 | EXPORT_SYMBOL(iget_locked); |
1070 | ||
261bca86 AV |
1071 | int insert_inode_locked(struct inode *inode) |
1072 | { | |
1073 | struct super_block *sb = inode->i_sb; | |
1074 | ino_t ino = inode->i_ino; | |
1075 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
261bca86 | 1076 | |
eaff8079 | 1077 | inode->i_state |= I_NEW; |
261bca86 | 1078 | while (1) { |
72a43d63 AV |
1079 | struct hlist_node *node; |
1080 | struct inode *old = NULL; | |
261bca86 | 1081 | spin_lock(&inode_lock); |
72a43d63 AV |
1082 | hlist_for_each_entry(old, node, head, i_hash) { |
1083 | if (old->i_ino != ino) | |
1084 | continue; | |
1085 | if (old->i_sb != sb) | |
1086 | continue; | |
a4ffdde6 | 1087 | if (old->i_state & (I_FREEING|I_WILL_FREE)) |
72a43d63 AV |
1088 | continue; |
1089 | break; | |
1090 | } | |
1091 | if (likely(!node)) { | |
261bca86 AV |
1092 | hlist_add_head(&inode->i_hash, head); |
1093 | spin_unlock(&inode_lock); | |
1094 | return 0; | |
1095 | } | |
1096 | __iget(old); | |
1097 | spin_unlock(&inode_lock); | |
1098 | wait_on_inode(old); | |
1099 | if (unlikely(!hlist_unhashed(&old->i_hash))) { | |
1100 | iput(old); | |
1101 | return -EBUSY; | |
1102 | } | |
1103 | iput(old); | |
1104 | } | |
1105 | } | |
261bca86 AV |
1106 | EXPORT_SYMBOL(insert_inode_locked); |
1107 | ||
1108 | int insert_inode_locked4(struct inode *inode, unsigned long hashval, | |
1109 | int (*test)(struct inode *, void *), void *data) | |
1110 | { | |
1111 | struct super_block *sb = inode->i_sb; | |
1112 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
261bca86 | 1113 | |
eaff8079 | 1114 | inode->i_state |= I_NEW; |
261bca86 AV |
1115 | |
1116 | while (1) { | |
72a43d63 AV |
1117 | struct hlist_node *node; |
1118 | struct inode *old = NULL; | |
1119 | ||
261bca86 | 1120 | spin_lock(&inode_lock); |
72a43d63 AV |
1121 | hlist_for_each_entry(old, node, head, i_hash) { |
1122 | if (old->i_sb != sb) | |
1123 | continue; | |
1124 | if (!test(old, data)) | |
1125 | continue; | |
a4ffdde6 | 1126 | if (old->i_state & (I_FREEING|I_WILL_FREE)) |
72a43d63 AV |
1127 | continue; |
1128 | break; | |
1129 | } | |
1130 | if (likely(!node)) { | |
261bca86 AV |
1131 | hlist_add_head(&inode->i_hash, head); |
1132 | spin_unlock(&inode_lock); | |
1133 | return 0; | |
1134 | } | |
1135 | __iget(old); | |
1136 | spin_unlock(&inode_lock); | |
1137 | wait_on_inode(old); | |
1138 | if (unlikely(!hlist_unhashed(&old->i_hash))) { | |
1139 | iput(old); | |
1140 | return -EBUSY; | |
1141 | } | |
1142 | iput(old); | |
1143 | } | |
1144 | } | |
261bca86 AV |
1145 | EXPORT_SYMBOL(insert_inode_locked4); |
1146 | ||
1da177e4 LT |
1147 | /** |
1148 | * __insert_inode_hash - hash an inode | |
1149 | * @inode: unhashed inode | |
1150 | * @hashval: unsigned long value used to locate this object in the | |
1151 | * inode_hashtable. | |
1152 | * | |
1153 | * Add an inode to the inode hash for this superblock. | |
1154 | */ | |
1155 | void __insert_inode_hash(struct inode *inode, unsigned long hashval) | |
1156 | { | |
1157 | struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval); | |
1158 | spin_lock(&inode_lock); | |
1159 | hlist_add_head(&inode->i_hash, head); | |
1160 | spin_unlock(&inode_lock); | |
1161 | } | |
1da177e4 LT |
1162 | EXPORT_SYMBOL(__insert_inode_hash); |
1163 | ||
1164 | /** | |
1165 | * remove_inode_hash - remove an inode from the hash | |
1166 | * @inode: inode to unhash | |
1167 | * | |
1168 | * Remove an inode from the superblock. | |
1169 | */ | |
1170 | void remove_inode_hash(struct inode *inode) | |
1171 | { | |
1172 | spin_lock(&inode_lock); | |
1173 | hlist_del_init(&inode->i_hash); | |
1174 | spin_unlock(&inode_lock); | |
1175 | } | |
1da177e4 LT |
1176 | EXPORT_SYMBOL(remove_inode_hash); |
1177 | ||
45321ac5 AV |
1178 | int generic_delete_inode(struct inode *inode) |
1179 | { | |
1180 | return 1; | |
1181 | } | |
1182 | EXPORT_SYMBOL(generic_delete_inode); | |
1183 | ||
1da177e4 | 1184 | /* |
45321ac5 AV |
1185 | * Normal UNIX filesystem behaviour: delete the |
1186 | * inode when the usage count drops to zero, and | |
1187 | * i_nlink is zero. | |
1da177e4 | 1188 | */ |
45321ac5 | 1189 | int generic_drop_inode(struct inode *inode) |
1da177e4 | 1190 | { |
45321ac5 | 1191 | return !inode->i_nlink || hlist_unhashed(&inode->i_hash); |
1da177e4 | 1192 | } |
45321ac5 | 1193 | EXPORT_SYMBOL_GPL(generic_drop_inode); |
1da177e4 | 1194 | |
45321ac5 AV |
1195 | /* |
1196 | * Called when we're dropping the last reference | |
1197 | * to an inode. | |
22fe4042 | 1198 | * |
45321ac5 AV |
1199 | * Call the FS "drop_inode()" function, defaulting to |
1200 | * the legacy UNIX filesystem behaviour. If it tells | |
1201 | * us to evict inode, do so. Otherwise, retain inode | |
1202 | * in cache if fs is alive, sync and evict if fs is | |
1203 | * shutting down. | |
22fe4042 | 1204 | */ |
45321ac5 | 1205 | static void iput_final(struct inode *inode) |
1da177e4 LT |
1206 | { |
1207 | struct super_block *sb = inode->i_sb; | |
45321ac5 AV |
1208 | const struct super_operations *op = inode->i_sb->s_op; |
1209 | int drop; | |
1210 | ||
1211 | if (op && op->drop_inode) | |
1212 | drop = op->drop_inode(inode); | |
1213 | else | |
1214 | drop = generic_drop_inode(inode); | |
1da177e4 | 1215 | |
45321ac5 | 1216 | if (!drop) { |
1c0eeaf5 | 1217 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) |
1da177e4 LT |
1218 | list_move(&inode->i_list, &inode_unused); |
1219 | inodes_stat.nr_unused++; | |
acb0c854 | 1220 | if (sb->s_flags & MS_ACTIVE) { |
991114c6 | 1221 | spin_unlock(&inode_lock); |
45321ac5 | 1222 | return; |
991114c6 | 1223 | } |
7ef0d737 | 1224 | WARN_ON(inode->i_state & I_NEW); |
991114c6 AV |
1225 | inode->i_state |= I_WILL_FREE; |
1226 | spin_unlock(&inode_lock); | |
1da177e4 LT |
1227 | write_inode_now(inode, 1); |
1228 | spin_lock(&inode_lock); | |
7ef0d737 | 1229 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1230 | inode->i_state &= ~I_WILL_FREE; |
1da177e4 LT |
1231 | inodes_stat.nr_unused--; |
1232 | hlist_del_init(&inode->i_hash); | |
1233 | } | |
1234 | list_del_init(&inode->i_list); | |
1235 | list_del_init(&inode->i_sb_list); | |
7ef0d737 | 1236 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1237 | inode->i_state |= I_FREEING; |
1da177e4 LT |
1238 | inodes_stat.nr_inodes--; |
1239 | spin_unlock(&inode_lock); | |
644da596 | 1240 | evict(inode); |
45321ac5 AV |
1241 | spin_lock(&inode_lock); |
1242 | hlist_del_init(&inode->i_hash); | |
1243 | spin_unlock(&inode_lock); | |
7f04c26d | 1244 | wake_up_inode(inode); |
45321ac5 | 1245 | BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); |
1da177e4 LT |
1246 | destroy_inode(inode); |
1247 | } | |
1248 | ||
1da177e4 | 1249 | /** |
6b3304b5 | 1250 | * iput - put an inode |
1da177e4 LT |
1251 | * @inode: inode to put |
1252 | * | |
1253 | * Puts an inode, dropping its usage count. If the inode use count hits | |
1254 | * zero, the inode is then freed and may also be destroyed. | |
1255 | * | |
1256 | * Consequently, iput() can sleep. | |
1257 | */ | |
1258 | void iput(struct inode *inode) | |
1259 | { | |
1260 | if (inode) { | |
a4ffdde6 | 1261 | BUG_ON(inode->i_state & I_CLEAR); |
1da177e4 | 1262 | |
1da177e4 LT |
1263 | if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) |
1264 | iput_final(inode); | |
1265 | } | |
1266 | } | |
1da177e4 LT |
1267 | EXPORT_SYMBOL(iput); |
1268 | ||
1269 | /** | |
1270 | * bmap - find a block number in a file | |
1271 | * @inode: inode of file | |
1272 | * @block: block to find | |
1273 | * | |
1274 | * Returns the block number on the device holding the inode that | |
1275 | * is the disk block number for the block of the file requested. | |
1276 | * That is, asked for block 4 of inode 1 the function will return the | |
6b3304b5 | 1277 | * disk block relative to the disk start that holds that block of the |
1da177e4 LT |
1278 | * file. |
1279 | */ | |
6b3304b5 | 1280 | sector_t bmap(struct inode *inode, sector_t block) |
1da177e4 LT |
1281 | { |
1282 | sector_t res = 0; | |
1283 | if (inode->i_mapping->a_ops->bmap) | |
1284 | res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); | |
1285 | return res; | |
1286 | } | |
1da177e4 LT |
1287 | EXPORT_SYMBOL(bmap); |
1288 | ||
11ff6f05 MG |
1289 | /* |
1290 | * With relative atime, only update atime if the previous atime is | |
1291 | * earlier than either the ctime or mtime or if at least a day has | |
1292 | * passed since the last atime update. | |
1293 | */ | |
1294 | static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, | |
1295 | struct timespec now) | |
1296 | { | |
1297 | ||
1298 | if (!(mnt->mnt_flags & MNT_RELATIME)) | |
1299 | return 1; | |
1300 | /* | |
1301 | * Is mtime younger than atime? If yes, update atime: | |
1302 | */ | |
1303 | if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0) | |
1304 | return 1; | |
1305 | /* | |
1306 | * Is ctime younger than atime? If yes, update atime: | |
1307 | */ | |
1308 | if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0) | |
1309 | return 1; | |
1310 | ||
1311 | /* | |
1312 | * Is the previous atime value older than a day? If yes, | |
1313 | * update atime: | |
1314 | */ | |
1315 | if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60) | |
1316 | return 1; | |
1317 | /* | |
1318 | * Good, we can skip the atime update: | |
1319 | */ | |
1320 | return 0; | |
1321 | } | |
1322 | ||
1da177e4 | 1323 | /** |
869243a0 CH |
1324 | * touch_atime - update the access time |
1325 | * @mnt: mount the inode is accessed on | |
7045f37b | 1326 | * @dentry: dentry accessed |
1da177e4 LT |
1327 | * |
1328 | * Update the accessed time on an inode and mark it for writeback. | |
1329 | * This function automatically handles read only file systems and media, | |
1330 | * as well as the "noatime" flag and inode specific "noatime" markers. | |
1331 | */ | |
869243a0 | 1332 | void touch_atime(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4 | 1333 | { |
869243a0 | 1334 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
1335 | struct timespec now; |
1336 | ||
cdb70f3f | 1337 | if (inode->i_flags & S_NOATIME) |
b12536c2 | 1338 | return; |
37756ced | 1339 | if (IS_NOATIME(inode)) |
b12536c2 | 1340 | return; |
b2276138 | 1341 | if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1342 | return; |
47ae32d6 | 1343 | |
cdb70f3f | 1344 | if (mnt->mnt_flags & MNT_NOATIME) |
b12536c2 | 1345 | return; |
cdb70f3f | 1346 | if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1347 | return; |
1da177e4 LT |
1348 | |
1349 | now = current_fs_time(inode->i_sb); | |
11ff6f05 MG |
1350 | |
1351 | if (!relatime_need_update(mnt, inode, now)) | |
b12536c2 | 1352 | return; |
11ff6f05 | 1353 | |
47ae32d6 | 1354 | if (timespec_equal(&inode->i_atime, &now)) |
b12536c2 AK |
1355 | return; |
1356 | ||
1357 | if (mnt_want_write(mnt)) | |
1358 | return; | |
47ae32d6 VH |
1359 | |
1360 | inode->i_atime = now; | |
1361 | mark_inode_dirty_sync(inode); | |
cdb70f3f | 1362 | mnt_drop_write(mnt); |
1da177e4 | 1363 | } |
869243a0 | 1364 | EXPORT_SYMBOL(touch_atime); |
1da177e4 LT |
1365 | |
1366 | /** | |
870f4817 CH |
1367 | * file_update_time - update mtime and ctime time |
1368 | * @file: file accessed | |
1da177e4 | 1369 | * |
870f4817 CH |
1370 | * Update the mtime and ctime members of an inode and mark the inode |
1371 | * for writeback. Note that this function is meant exclusively for | |
1372 | * usage in the file write path of filesystems, and filesystems may | |
1373 | * choose to explicitly ignore update via this function with the | |
2eadfc0e | 1374 | * S_NOCMTIME inode flag, e.g. for network filesystem where these |
870f4817 | 1375 | * timestamps are handled by the server. |
1da177e4 LT |
1376 | */ |
1377 | ||
870f4817 | 1378 | void file_update_time(struct file *file) |
1da177e4 | 1379 | { |
0f7fc9e4 | 1380 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 | 1381 | struct timespec now; |
ce06e0b2 | 1382 | enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0; |
1da177e4 | 1383 | |
ce06e0b2 | 1384 | /* First try to exhaust all avenues to not sync */ |
1da177e4 LT |
1385 | if (IS_NOCMTIME(inode)) |
1386 | return; | |
20ddee2c | 1387 | |
1da177e4 | 1388 | now = current_fs_time(inode->i_sb); |
ce06e0b2 AK |
1389 | if (!timespec_equal(&inode->i_mtime, &now)) |
1390 | sync_it = S_MTIME; | |
1da177e4 | 1391 | |
ce06e0b2 AK |
1392 | if (!timespec_equal(&inode->i_ctime, &now)) |
1393 | sync_it |= S_CTIME; | |
870f4817 | 1394 | |
ce06e0b2 AK |
1395 | if (IS_I_VERSION(inode)) |
1396 | sync_it |= S_VERSION; | |
7a224228 | 1397 | |
ce06e0b2 AK |
1398 | if (!sync_it) |
1399 | return; | |
1400 | ||
1401 | /* Finally allowed to write? Takes lock. */ | |
1402 | if (mnt_want_write_file(file)) | |
1403 | return; | |
1404 | ||
1405 | /* Only change inode inside the lock region */ | |
1406 | if (sync_it & S_VERSION) | |
1407 | inode_inc_iversion(inode); | |
1408 | if (sync_it & S_CTIME) | |
1409 | inode->i_ctime = now; | |
1410 | if (sync_it & S_MTIME) | |
1411 | inode->i_mtime = now; | |
1412 | mark_inode_dirty_sync(inode); | |
20ddee2c | 1413 | mnt_drop_write(file->f_path.mnt); |
1da177e4 | 1414 | } |
870f4817 | 1415 | EXPORT_SYMBOL(file_update_time); |
1da177e4 LT |
1416 | |
1417 | int inode_needs_sync(struct inode *inode) | |
1418 | { | |
1419 | if (IS_SYNC(inode)) | |
1420 | return 1; | |
1421 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) | |
1422 | return 1; | |
1423 | return 0; | |
1424 | } | |
1da177e4 LT |
1425 | EXPORT_SYMBOL(inode_needs_sync); |
1426 | ||
1da177e4 LT |
1427 | int inode_wait(void *word) |
1428 | { | |
1429 | schedule(); | |
1430 | return 0; | |
1431 | } | |
d44dab8d | 1432 | EXPORT_SYMBOL(inode_wait); |
1da177e4 LT |
1433 | |
1434 | /* | |
168a9fd6 MS |
1435 | * If we try to find an inode in the inode hash while it is being |
1436 | * deleted, we have to wait until the filesystem completes its | |
1437 | * deletion before reporting that it isn't found. This function waits | |
1438 | * until the deletion _might_ have completed. Callers are responsible | |
1439 | * to recheck inode state. | |
1440 | * | |
eaff8079 | 1441 | * It doesn't matter if I_NEW is not set initially, a call to |
168a9fd6 MS |
1442 | * wake_up_inode() after removing from the hash list will DTRT. |
1443 | * | |
1da177e4 LT |
1444 | * This is called with inode_lock held. |
1445 | */ | |
1446 | static void __wait_on_freeing_inode(struct inode *inode) | |
1447 | { | |
1448 | wait_queue_head_t *wq; | |
eaff8079 CH |
1449 | DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); |
1450 | wq = bit_waitqueue(&inode->i_state, __I_NEW); | |
1da177e4 LT |
1451 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); |
1452 | spin_unlock(&inode_lock); | |
1453 | schedule(); | |
1454 | finish_wait(wq, &wait.wait); | |
1455 | spin_lock(&inode_lock); | |
1456 | } | |
1457 | ||
1da177e4 LT |
1458 | static __initdata unsigned long ihash_entries; |
1459 | static int __init set_ihash_entries(char *str) | |
1460 | { | |
1461 | if (!str) | |
1462 | return 0; | |
1463 | ihash_entries = simple_strtoul(str, &str, 0); | |
1464 | return 1; | |
1465 | } | |
1466 | __setup("ihash_entries=", set_ihash_entries); | |
1467 | ||
1468 | /* | |
1469 | * Initialize the waitqueues and inode hash table. | |
1470 | */ | |
1471 | void __init inode_init_early(void) | |
1472 | { | |
1473 | int loop; | |
1474 | ||
1475 | /* If hashes are distributed across NUMA nodes, defer | |
1476 | * hash allocation until vmalloc space is available. | |
1477 | */ | |
1478 | if (hashdist) | |
1479 | return; | |
1480 | ||
1481 | inode_hashtable = | |
1482 | alloc_large_system_hash("Inode-cache", | |
1483 | sizeof(struct hlist_head), | |
1484 | ihash_entries, | |
1485 | 14, | |
1486 | HASH_EARLY, | |
1487 | &i_hash_shift, | |
1488 | &i_hash_mask, | |
1489 | 0); | |
1490 | ||
1491 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1492 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1493 | } | |
1494 | ||
74bf17cf | 1495 | void __init inode_init(void) |
1da177e4 LT |
1496 | { |
1497 | int loop; | |
1498 | ||
1499 | /* inode slab cache */ | |
b0196009 PJ |
1500 | inode_cachep = kmem_cache_create("inode_cache", |
1501 | sizeof(struct inode), | |
1502 | 0, | |
1503 | (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| | |
1504 | SLAB_MEM_SPREAD), | |
20c2df83 | 1505 | init_once); |
8e1f936b | 1506 | register_shrinker(&icache_shrinker); |
1da177e4 LT |
1507 | |
1508 | /* Hash may have been set up in inode_init_early */ | |
1509 | if (!hashdist) | |
1510 | return; | |
1511 | ||
1512 | inode_hashtable = | |
1513 | alloc_large_system_hash("Inode-cache", | |
1514 | sizeof(struct hlist_head), | |
1515 | ihash_entries, | |
1516 | 14, | |
1517 | 0, | |
1518 | &i_hash_shift, | |
1519 | &i_hash_mask, | |
1520 | 0); | |
1521 | ||
1522 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1523 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1524 | } | |
1525 | ||
1526 | void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) | |
1527 | { | |
1528 | inode->i_mode = mode; | |
1529 | if (S_ISCHR(mode)) { | |
1530 | inode->i_fop = &def_chr_fops; | |
1531 | inode->i_rdev = rdev; | |
1532 | } else if (S_ISBLK(mode)) { | |
1533 | inode->i_fop = &def_blk_fops; | |
1534 | inode->i_rdev = rdev; | |
1535 | } else if (S_ISFIFO(mode)) | |
1536 | inode->i_fop = &def_fifo_fops; | |
1537 | else if (S_ISSOCK(mode)) | |
1538 | inode->i_fop = &bad_sock_fops; | |
1539 | else | |
af0d9ae8 MK |
1540 | printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for" |
1541 | " inode %s:%lu\n", mode, inode->i_sb->s_id, | |
1542 | inode->i_ino); | |
1da177e4 LT |
1543 | } |
1544 | EXPORT_SYMBOL(init_special_inode); | |
a1bd120d DM |
1545 | |
1546 | /** | |
1547 | * Init uid,gid,mode for new inode according to posix standards | |
1548 | * @inode: New inode | |
1549 | * @dir: Directory inode | |
1550 | * @mode: mode of the new inode | |
1551 | */ | |
1552 | void inode_init_owner(struct inode *inode, const struct inode *dir, | |
1553 | mode_t mode) | |
1554 | { | |
1555 | inode->i_uid = current_fsuid(); | |
1556 | if (dir && dir->i_mode & S_ISGID) { | |
1557 | inode->i_gid = dir->i_gid; | |
1558 | if (S_ISDIR(mode)) | |
1559 | mode |= S_ISGID; | |
1560 | } else | |
1561 | inode->i_gid = current_fsgid(); | |
1562 | inode->i_mode = mode; | |
1563 | } | |
1564 | EXPORT_SYMBOL(inode_init_owner); |