]>
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> |
1da177e4 LT |
27 | |
28 | /* | |
29 | * This is needed for the following functions: | |
30 | * - inode_has_buffers | |
31 | * - invalidate_inode_buffers | |
1da177e4 LT |
32 | * - invalidate_bdev |
33 | * | |
34 | * FIXME: remove all knowledge of the buffer layer from this file | |
35 | */ | |
36 | #include <linux/buffer_head.h> | |
37 | ||
38 | /* | |
39 | * New inode.c implementation. | |
40 | * | |
41 | * This implementation has the basic premise of trying | |
42 | * to be extremely low-overhead and SMP-safe, yet be | |
43 | * simple enough to be "obviously correct". | |
44 | * | |
45 | * Famous last words. | |
46 | */ | |
47 | ||
48 | /* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */ | |
49 | ||
50 | /* #define INODE_PARANOIA 1 */ | |
51 | /* #define INODE_DEBUG 1 */ | |
52 | ||
53 | /* | |
54 | * Inode lookup is no longer as critical as it used to be: | |
55 | * most of the lookups are going to be through the dcache. | |
56 | */ | |
57 | #define I_HASHBITS i_hash_shift | |
58 | #define I_HASHMASK i_hash_mask | |
59 | ||
fa3536cc ED |
60 | static unsigned int i_hash_mask __read_mostly; |
61 | static unsigned int i_hash_shift __read_mostly; | |
1da177e4 LT |
62 | |
63 | /* | |
64 | * Each inode can be on two separate lists. One is | |
65 | * the hash list of the inode, used for lookups. The | |
66 | * other linked list is the "type" list: | |
67 | * "in_use" - valid inode, i_count > 0, i_nlink > 0 | |
68 | * "dirty" - as "in_use" but also dirty | |
69 | * "unused" - valid inode, i_count = 0 | |
70 | * | |
71 | * A "dirty" list is maintained for each super block, | |
72 | * allowing for low-overhead inode sync() operations. | |
73 | */ | |
74 | ||
75 | LIST_HEAD(inode_in_use); | |
76 | LIST_HEAD(inode_unused); | |
fa3536cc | 77 | static struct hlist_head *inode_hashtable __read_mostly; |
1da177e4 LT |
78 | |
79 | /* | |
80 | * A simple spinlock to protect the list manipulations. | |
81 | * | |
82 | * NOTE! You also have to own the lock if you change | |
83 | * the i_state of an inode while it is in use.. | |
84 | */ | |
85 | DEFINE_SPINLOCK(inode_lock); | |
86 | ||
87 | /* | |
88e0fbc4 | 88 | * iprune_sem provides exclusion between the kswapd or try_to_free_pages |
1da177e4 LT |
89 | * icache shrinking path, and the umount path. Without this exclusion, |
90 | * by the time prune_icache calls iput for the inode whose pages it has | |
91 | * been invalidating, or by the time it calls clear_inode & destroy_inode | |
92 | * from its final dispose_list, the struct super_block they refer to | |
93 | * (for inode->i_sb->s_op) may already have been freed and reused. | |
88e0fbc4 NP |
94 | * |
95 | * We make this an rwsem because the fastpath is icache shrinking. In | |
96 | * some cases a filesystem may be doing a significant amount of work in | |
97 | * its inode reclaim code, so this should improve parallelism. | |
1da177e4 | 98 | */ |
88e0fbc4 | 99 | static DECLARE_RWSEM(iprune_sem); |
1da177e4 LT |
100 | |
101 | /* | |
102 | * Statistics gathering.. | |
103 | */ | |
104 | struct inodes_stat_t inodes_stat; | |
105 | ||
6b3304b5 | 106 | static struct kmem_cache *inode_cachep __read_mostly; |
1da177e4 | 107 | |
1c0eeaf5 JE |
108 | static void wake_up_inode(struct inode *inode) |
109 | { | |
110 | /* | |
111 | * Prevent speculative execution through spin_unlock(&inode_lock); | |
112 | */ | |
113 | smp_mb(); | |
eaff8079 | 114 | wake_up_bit(&inode->i_state, __I_NEW); |
1c0eeaf5 JE |
115 | } |
116 | ||
2cb1599f DC |
117 | /** |
118 | * inode_init_always - perform inode structure intialisation | |
0bc02f3f RD |
119 | * @sb: superblock inode belongs to |
120 | * @inode: inode to initialise | |
2cb1599f DC |
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 | */ | |
54e34621 | 125 | int inode_init_always(struct super_block *sb, struct inode *inode) |
1da177e4 | 126 | { |
f5e54d6e | 127 | static const struct address_space_operations empty_aops; |
6e1d5dcc | 128 | static const struct inode_operations empty_iops; |
99ac48f5 | 129 | static const struct file_operations empty_fops; |
6b3304b5 | 130 | struct address_space *const mapping = &inode->i_data; |
2cb1599f DC |
131 | |
132 | inode->i_sb = sb; | |
133 | inode->i_blkbits = sb->s_blocksize_bits; | |
134 | inode->i_flags = 0; | |
135 | atomic_set(&inode->i_count, 1); | |
136 | inode->i_op = &empty_iops; | |
137 | inode->i_fop = &empty_fops; | |
138 | inode->i_nlink = 1; | |
56ff5efa AV |
139 | inode->i_uid = 0; |
140 | inode->i_gid = 0; | |
2cb1599f DC |
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; | |
1da177e4 | 146 | #ifdef CONFIG_QUOTA |
2cb1599f | 147 | memset(&inode->i_dquot, 0, sizeof(inode->i_dquot)); |
1da177e4 | 148 | #endif |
2cb1599f DC |
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; | |
6146f0d5 MZ |
154 | |
155 | if (security_inode_alloc(inode)) | |
54e34621 | 156 | goto out; |
2cb1599f DC |
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 | init_rwsem(&inode->i_alloc_sem); | |
164 | lockdep_set_class(&inode->i_alloc_sem, &sb->s_type->i_alloc_sem_key); | |
165 | ||
166 | mapping->a_ops = &empty_aops; | |
167 | mapping->host = inode; | |
168 | mapping->flags = 0; | |
3c1d4378 | 169 | mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE); |
2cb1599f DC |
170 | mapping->assoc_mapping = NULL; |
171 | mapping->backing_dev_info = &default_backing_dev_info; | |
172 | mapping->writeback_index = 0; | |
173 | ||
174 | /* | |
175 | * If the block_device provides a backing_dev_info for client | |
176 | * inodes then use that. Otherwise the inode share the bdev's | |
177 | * backing_dev_info. | |
178 | */ | |
179 | if (sb->s_bdev) { | |
180 | struct backing_dev_info *bdi; | |
181 | ||
2c96ce9f | 182 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; |
2cb1599f DC |
183 | mapping->backing_dev_info = bdi; |
184 | } | |
185 | inode->i_private = NULL; | |
186 | inode->i_mapping = mapping; | |
f19d4a8f AV |
187 | #ifdef CONFIG_FS_POSIX_ACL |
188 | inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; | |
189 | #endif | |
2cb1599f | 190 | |
3be25f49 EP |
191 | #ifdef CONFIG_FSNOTIFY |
192 | inode->i_fsnotify_mask = 0; | |
193 | #endif | |
194 | ||
54e34621 | 195 | return 0; |
54e34621 CH |
196 | out: |
197 | return -ENOMEM; | |
1da177e4 | 198 | } |
2cb1599f DC |
199 | EXPORT_SYMBOL(inode_init_always); |
200 | ||
201 | static struct inode *alloc_inode(struct super_block *sb) | |
202 | { | |
203 | struct inode *inode; | |
204 | ||
205 | if (sb->s_op->alloc_inode) | |
206 | inode = sb->s_op->alloc_inode(sb); | |
207 | else | |
208 | inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL); | |
209 | ||
54e34621 CH |
210 | if (!inode) |
211 | return NULL; | |
212 | ||
213 | if (unlikely(inode_init_always(sb, inode))) { | |
214 | if (inode->i_sb->s_op->destroy_inode) | |
215 | inode->i_sb->s_op->destroy_inode(inode); | |
216 | else | |
217 | kmem_cache_free(inode_cachep, inode); | |
218 | return NULL; | |
219 | } | |
220 | ||
221 | return inode; | |
2cb1599f | 222 | } |
1da177e4 | 223 | |
2e00c97e | 224 | void __destroy_inode(struct inode *inode) |
1da177e4 | 225 | { |
b7542f8c | 226 | BUG_ON(inode_has_buffers(inode)); |
1da177e4 | 227 | security_inode_free(inode); |
3be25f49 | 228 | fsnotify_inode_delete(inode); |
f19d4a8f AV |
229 | #ifdef CONFIG_FS_POSIX_ACL |
230 | if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED) | |
231 | posix_acl_release(inode->i_acl); | |
232 | if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) | |
233 | posix_acl_release(inode->i_default_acl); | |
234 | #endif | |
2e00c97e CH |
235 | } |
236 | EXPORT_SYMBOL(__destroy_inode); | |
237 | ||
56b0dacf | 238 | static void destroy_inode(struct inode *inode) |
2e00c97e CH |
239 | { |
240 | __destroy_inode(inode); | |
1da177e4 LT |
241 | if (inode->i_sb->s_op->destroy_inode) |
242 | inode->i_sb->s_op->destroy_inode(inode); | |
243 | else | |
244 | kmem_cache_free(inode_cachep, (inode)); | |
245 | } | |
1da177e4 LT |
246 | |
247 | /* | |
248 | * These are initializations that only need to be done | |
249 | * once, because the fields are idempotent across use | |
250 | * of the inode, so let the slab aware of that. | |
251 | */ | |
252 | void inode_init_once(struct inode *inode) | |
253 | { | |
254 | memset(inode, 0, sizeof(*inode)); | |
255 | INIT_HLIST_NODE(&inode->i_hash); | |
256 | INIT_LIST_HEAD(&inode->i_dentry); | |
257 | INIT_LIST_HEAD(&inode->i_devices); | |
1da177e4 | 258 | INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); |
19fd6231 | 259 | spin_lock_init(&inode->i_data.tree_lock); |
1da177e4 LT |
260 | spin_lock_init(&inode->i_data.i_mmap_lock); |
261 | INIT_LIST_HEAD(&inode->i_data.private_list); | |
262 | spin_lock_init(&inode->i_data.private_lock); | |
263 | INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap); | |
264 | INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); | |
1da177e4 | 265 | i_size_ordered_init(inode); |
3be25f49 | 266 | #ifdef CONFIG_FSNOTIFY |
e61ce867 | 267 | INIT_HLIST_HEAD(&inode->i_fsnotify_marks); |
3be25f49 | 268 | #endif |
1da177e4 | 269 | } |
1da177e4 LT |
270 | EXPORT_SYMBOL(inode_init_once); |
271 | ||
51cc5068 | 272 | static void init_once(void *foo) |
1da177e4 | 273 | { |
6b3304b5 | 274 | struct inode *inode = (struct inode *) foo; |
1da177e4 | 275 | |
a35afb83 | 276 | inode_init_once(inode); |
1da177e4 LT |
277 | } |
278 | ||
279 | /* | |
280 | * inode_lock must be held | |
281 | */ | |
6b3304b5 | 282 | void __iget(struct inode *inode) |
1da177e4 | 283 | { |
2e147f1e | 284 | if (atomic_inc_return(&inode->i_count) != 1) |
1da177e4 | 285 | return; |
2e147f1e | 286 | |
1c0eeaf5 | 287 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) |
1da177e4 LT |
288 | list_move(&inode->i_list, &inode_in_use); |
289 | inodes_stat.nr_unused--; | |
290 | } | |
291 | ||
b0683aa6 AV |
292 | void end_writeback(struct inode *inode) |
293 | { | |
294 | might_sleep(); | |
295 | BUG_ON(inode->i_data.nrpages); | |
296 | BUG_ON(!list_empty(&inode->i_data.private_list)); | |
297 | BUG_ON(!(inode->i_state & I_FREEING)); | |
298 | BUG_ON(inode->i_state & I_CLEAR); | |
299 | inode_sync_wait(inode); | |
300 | inode->i_state = I_FREEING | I_CLEAR; | |
301 | } | |
302 | EXPORT_SYMBOL(end_writeback); | |
303 | ||
644da596 | 304 | static void evict(struct inode *inode) |
b4272d4c AV |
305 | { |
306 | const struct super_operations *op = inode->i_sb->s_op; | |
307 | ||
be7ce416 AV |
308 | if (op->evict_inode) { |
309 | op->evict_inode(inode); | |
b4272d4c AV |
310 | } else { |
311 | if (inode->i_data.nrpages) | |
312 | truncate_inode_pages(&inode->i_data, 0); | |
30140837 | 313 | end_writeback(inode); |
b4272d4c | 314 | } |
661074e9 AV |
315 | if (S_ISBLK(inode->i_mode) && inode->i_bdev) |
316 | bd_forget(inode); | |
317 | if (S_ISCHR(inode->i_mode) && inode->i_cdev) | |
318 | cd_forget(inode); | |
b4272d4c AV |
319 | } |
320 | ||
1da177e4 LT |
321 | /* |
322 | * dispose_list - dispose of the contents of a local list | |
323 | * @head: the head of the list to free | |
324 | * | |
325 | * Dispose-list gets a local list with local inodes in it, so it doesn't | |
326 | * need to worry about list corruption and SMP locks. | |
327 | */ | |
328 | static void dispose_list(struct list_head *head) | |
329 | { | |
330 | int nr_disposed = 0; | |
331 | ||
332 | while (!list_empty(head)) { | |
333 | struct inode *inode; | |
334 | ||
b5e61818 | 335 | inode = list_first_entry(head, struct inode, i_list); |
1da177e4 LT |
336 | list_del(&inode->i_list); |
337 | ||
644da596 | 338 | evict(inode); |
4120db47 AB |
339 | |
340 | spin_lock(&inode_lock); | |
341 | hlist_del_init(&inode->i_hash); | |
342 | list_del_init(&inode->i_sb_list); | |
343 | spin_unlock(&inode_lock); | |
344 | ||
345 | wake_up_inode(inode); | |
1da177e4 LT |
346 | destroy_inode(inode); |
347 | nr_disposed++; | |
348 | } | |
349 | spin_lock(&inode_lock); | |
350 | inodes_stat.nr_inodes -= nr_disposed; | |
351 | spin_unlock(&inode_lock); | |
352 | } | |
353 | ||
354 | /* | |
355 | * Invalidate all inodes for a device. | |
356 | */ | |
357 | static int invalidate_list(struct list_head *head, struct list_head *dispose) | |
358 | { | |
359 | struct list_head *next; | |
360 | int busy = 0, count = 0; | |
361 | ||
362 | next = head->next; | |
363 | for (;;) { | |
6b3304b5 MK |
364 | struct list_head *tmp = next; |
365 | struct inode *inode; | |
1da177e4 LT |
366 | |
367 | /* | |
368 | * We can reschedule here without worrying about the list's | |
369 | * consistency because the per-sb list of inodes must not | |
88e0fbc4 | 370 | * change during umount anymore, and because iprune_sem keeps |
1da177e4 LT |
371 | * shrink_icache_memory() away. |
372 | */ | |
373 | cond_resched_lock(&inode_lock); | |
374 | ||
375 | next = next->next; | |
376 | if (tmp == head) | |
377 | break; | |
378 | inode = list_entry(tmp, struct inode, i_sb_list); | |
aabb8fdb NP |
379 | if (inode->i_state & I_NEW) |
380 | continue; | |
1da177e4 LT |
381 | invalidate_inode_buffers(inode); |
382 | if (!atomic_read(&inode->i_count)) { | |
1da177e4 | 383 | list_move(&inode->i_list, dispose); |
7ef0d737 | 384 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 LT |
385 | inode->i_state |= I_FREEING; |
386 | count++; | |
387 | continue; | |
388 | } | |
389 | busy = 1; | |
390 | } | |
391 | /* only unused inodes may be cached with i_count zero */ | |
392 | inodes_stat.nr_unused -= count; | |
393 | return busy; | |
394 | } | |
395 | ||
1da177e4 LT |
396 | /** |
397 | * invalidate_inodes - discard the inodes on a device | |
398 | * @sb: superblock | |
399 | * | |
400 | * Discard all of the inodes for a given superblock. If the discard | |
401 | * fails because there are busy inodes then a non zero value is returned. | |
402 | * If the discard is successful all the inodes have been discarded. | |
403 | */ | |
6b3304b5 | 404 | int invalidate_inodes(struct super_block *sb) |
1da177e4 LT |
405 | { |
406 | int busy; | |
407 | LIST_HEAD(throw_away); | |
408 | ||
88e0fbc4 | 409 | down_write(&iprune_sem); |
1da177e4 | 410 | spin_lock(&inode_lock); |
164bc619 | 411 | fsnotify_unmount_inodes(&sb->s_inodes); |
1da177e4 LT |
412 | busy = invalidate_list(&sb->s_inodes, &throw_away); |
413 | spin_unlock(&inode_lock); | |
414 | ||
415 | dispose_list(&throw_away); | |
88e0fbc4 | 416 | up_write(&iprune_sem); |
1da177e4 LT |
417 | |
418 | return busy; | |
419 | } | |
1da177e4 LT |
420 | |
421 | static int can_unuse(struct inode *inode) | |
422 | { | |
423 | if (inode->i_state) | |
424 | return 0; | |
425 | if (inode_has_buffers(inode)) | |
426 | return 0; | |
427 | if (atomic_read(&inode->i_count)) | |
428 | return 0; | |
429 | if (inode->i_data.nrpages) | |
430 | return 0; | |
431 | return 1; | |
432 | } | |
433 | ||
434 | /* | |
435 | * Scan `goal' inodes on the unused list for freeable ones. They are moved to | |
436 | * a temporary list and then are freed outside inode_lock by dispose_list(). | |
437 | * | |
438 | * Any inodes which are pinned purely because of attached pagecache have their | |
439 | * pagecache removed. We expect the final iput() on that inode to add it to | |
440 | * the front of the inode_unused list. So look for it there and if the | |
441 | * inode is still freeable, proceed. The right inode is found 99.9% of the | |
442 | * time in testing on a 4-way. | |
443 | * | |
444 | * If the inode has metadata buffers attached to mapping->private_list then | |
445 | * try to remove them. | |
446 | */ | |
447 | static void prune_icache(int nr_to_scan) | |
448 | { | |
449 | LIST_HEAD(freeable); | |
450 | int nr_pruned = 0; | |
451 | int nr_scanned; | |
452 | unsigned long reap = 0; | |
453 | ||
88e0fbc4 | 454 | down_read(&iprune_sem); |
1da177e4 LT |
455 | spin_lock(&inode_lock); |
456 | for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { | |
457 | struct inode *inode; | |
458 | ||
459 | if (list_empty(&inode_unused)) | |
460 | break; | |
461 | ||
462 | inode = list_entry(inode_unused.prev, struct inode, i_list); | |
463 | ||
464 | if (inode->i_state || atomic_read(&inode->i_count)) { | |
465 | list_move(&inode->i_list, &inode_unused); | |
466 | continue; | |
467 | } | |
468 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { | |
469 | __iget(inode); | |
470 | spin_unlock(&inode_lock); | |
471 | if (remove_inode_buffers(inode)) | |
fc0ecff6 AM |
472 | reap += invalidate_mapping_pages(&inode->i_data, |
473 | 0, -1); | |
1da177e4 LT |
474 | iput(inode); |
475 | spin_lock(&inode_lock); | |
476 | ||
477 | if (inode != list_entry(inode_unused.next, | |
478 | struct inode, i_list)) | |
479 | continue; /* wrong inode or list_empty */ | |
480 | if (!can_unuse(inode)) | |
481 | continue; | |
482 | } | |
1da177e4 | 483 | list_move(&inode->i_list, &freeable); |
7ef0d737 | 484 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 LT |
485 | inode->i_state |= I_FREEING; |
486 | nr_pruned++; | |
487 | } | |
488 | inodes_stat.nr_unused -= nr_pruned; | |
f8891e5e CL |
489 | if (current_is_kswapd()) |
490 | __count_vm_events(KSWAPD_INODESTEAL, reap); | |
491 | else | |
492 | __count_vm_events(PGINODESTEAL, reap); | |
1da177e4 LT |
493 | spin_unlock(&inode_lock); |
494 | ||
495 | dispose_list(&freeable); | |
88e0fbc4 | 496 | up_read(&iprune_sem); |
1da177e4 LT |
497 | } |
498 | ||
499 | /* | |
500 | * shrink_icache_memory() will attempt to reclaim some unused inodes. Here, | |
501 | * "unused" means that no dentries are referring to the inodes: the files are | |
502 | * not open and the dcache references to those inodes have already been | |
503 | * reclaimed. | |
504 | * | |
505 | * This function is passed the number of inodes to scan, and it returns the | |
506 | * total number of remaining possibly-reclaimable inodes. | |
507 | */ | |
7f8275d0 | 508 | static int shrink_icache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask) |
1da177e4 LT |
509 | { |
510 | if (nr) { | |
511 | /* | |
512 | * Nasty deadlock avoidance. We may hold various FS locks, | |
513 | * and we don't want to recurse into the FS that called us | |
514 | * in clear_inode() and friends.. | |
6b3304b5 | 515 | */ |
1da177e4 LT |
516 | if (!(gfp_mask & __GFP_FS)) |
517 | return -1; | |
518 | prune_icache(nr); | |
519 | } | |
520 | return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure; | |
521 | } | |
522 | ||
8e1f936b RR |
523 | static struct shrinker icache_shrinker = { |
524 | .shrink = shrink_icache_memory, | |
525 | .seeks = DEFAULT_SEEKS, | |
526 | }; | |
527 | ||
1da177e4 LT |
528 | static void __wait_on_freeing_inode(struct inode *inode); |
529 | /* | |
530 | * Called with the inode lock held. | |
531 | * NOTE: we are not increasing the inode-refcount, you must call __iget() | |
532 | * by hand after calling find_inode now! This simplifies iunique and won't | |
533 | * add any additional branch in the common code. | |
534 | */ | |
6b3304b5 MK |
535 | static struct inode *find_inode(struct super_block *sb, |
536 | struct hlist_head *head, | |
537 | int (*test)(struct inode *, void *), | |
538 | void *data) | |
1da177e4 LT |
539 | { |
540 | struct hlist_node *node; | |
6b3304b5 | 541 | struct inode *inode = NULL; |
1da177e4 LT |
542 | |
543 | repeat: | |
c5c8be3c | 544 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
545 | if (inode->i_sb != sb) |
546 | continue; | |
547 | if (!test(inode, data)) | |
548 | continue; | |
a4ffdde6 | 549 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
1da177e4 LT |
550 | __wait_on_freeing_inode(inode); |
551 | goto repeat; | |
552 | } | |
553 | break; | |
554 | } | |
555 | return node ? inode : NULL; | |
556 | } | |
557 | ||
558 | /* | |
559 | * find_inode_fast is the fast path version of find_inode, see the comment at | |
560 | * iget_locked for details. | |
561 | */ | |
6b3304b5 MK |
562 | static struct inode *find_inode_fast(struct super_block *sb, |
563 | struct hlist_head *head, unsigned long ino) | |
1da177e4 LT |
564 | { |
565 | struct hlist_node *node; | |
6b3304b5 | 566 | struct inode *inode = NULL; |
1da177e4 LT |
567 | |
568 | repeat: | |
c5c8be3c | 569 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
570 | if (inode->i_ino != ino) |
571 | continue; | |
572 | if (inode->i_sb != sb) | |
573 | continue; | |
a4ffdde6 | 574 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
1da177e4 LT |
575 | __wait_on_freeing_inode(inode); |
576 | goto repeat; | |
577 | } | |
578 | break; | |
579 | } | |
580 | return node ? inode : NULL; | |
581 | } | |
582 | ||
8290c35f DC |
583 | static unsigned long hash(struct super_block *sb, unsigned long hashval) |
584 | { | |
585 | unsigned long tmp; | |
586 | ||
587 | tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / | |
588 | L1_CACHE_BYTES; | |
589 | tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS); | |
590 | return tmp & I_HASHMASK; | |
591 | } | |
592 | ||
593 | static inline void | |
594 | __inode_add_to_lists(struct super_block *sb, struct hlist_head *head, | |
595 | struct inode *inode) | |
596 | { | |
597 | inodes_stat.nr_inodes++; | |
598 | list_add(&inode->i_list, &inode_in_use); | |
599 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
600 | if (head) | |
601 | hlist_add_head(&inode->i_hash, head); | |
602 | } | |
603 | ||
604 | /** | |
605 | * inode_add_to_lists - add a new inode to relevant lists | |
0bc02f3f RD |
606 | * @sb: superblock inode belongs to |
607 | * @inode: inode to mark in use | |
8290c35f DC |
608 | * |
609 | * When an inode is allocated it needs to be accounted for, added to the in use | |
610 | * list, the owning superblock and the inode hash. This needs to be done under | |
611 | * the inode_lock, so export a function to do this rather than the inode lock | |
612 | * itself. We calculate the hash list to add to here so it is all internal | |
613 | * which requires the caller to have already set up the inode number in the | |
614 | * inode to add. | |
615 | */ | |
616 | void inode_add_to_lists(struct super_block *sb, struct inode *inode) | |
617 | { | |
618 | struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino); | |
619 | ||
620 | spin_lock(&inode_lock); | |
621 | __inode_add_to_lists(sb, head, inode); | |
622 | spin_unlock(&inode_lock); | |
623 | } | |
624 | EXPORT_SYMBOL_GPL(inode_add_to_lists); | |
625 | ||
1da177e4 LT |
626 | /** |
627 | * new_inode - obtain an inode | |
628 | * @sb: superblock | |
629 | * | |
769848c0 | 630 | * Allocates a new inode for given superblock. The default gfp_mask |
3c1d4378 | 631 | * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE. |
769848c0 MG |
632 | * If HIGHMEM pages are unsuitable or it is known that pages allocated |
633 | * for the page cache are not reclaimable or migratable, | |
634 | * mapping_set_gfp_mask() must be called with suitable flags on the | |
635 | * newly created inode's mapping | |
636 | * | |
1da177e4 LT |
637 | */ |
638 | struct inode *new_inode(struct super_block *sb) | |
639 | { | |
866b04fc JL |
640 | /* |
641 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
642 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
643 | * here to attempt to avoid that. | |
644 | */ | |
645 | static unsigned int last_ino; | |
6b3304b5 | 646 | struct inode *inode; |
1da177e4 LT |
647 | |
648 | spin_lock_prefetch(&inode_lock); | |
6b3304b5 | 649 | |
1da177e4 LT |
650 | inode = alloc_inode(sb); |
651 | if (inode) { | |
652 | spin_lock(&inode_lock); | |
8290c35f | 653 | __inode_add_to_lists(sb, NULL, inode); |
1da177e4 LT |
654 | inode->i_ino = ++last_ino; |
655 | inode->i_state = 0; | |
656 | spin_unlock(&inode_lock); | |
657 | } | |
658 | return inode; | |
659 | } | |
1da177e4 LT |
660 | EXPORT_SYMBOL(new_inode); |
661 | ||
662 | void unlock_new_inode(struct inode *inode) | |
663 | { | |
14358e6d | 664 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
a3314a0e | 665 | if (S_ISDIR(inode->i_mode)) { |
1e89a5e1 PZ |
666 | struct file_system_type *type = inode->i_sb->s_type; |
667 | ||
9a7aa12f JK |
668 | /* Set new key only if filesystem hasn't already changed it */ |
669 | if (!lockdep_match_class(&inode->i_mutex, | |
670 | &type->i_mutex_key)) { | |
671 | /* | |
672 | * ensure nobody is actually holding i_mutex | |
673 | */ | |
674 | mutex_destroy(&inode->i_mutex); | |
675 | mutex_init(&inode->i_mutex); | |
676 | lockdep_set_class(&inode->i_mutex, | |
677 | &type->i_mutex_dir_key); | |
678 | } | |
1e89a5e1 | 679 | } |
14358e6d | 680 | #endif |
1da177e4 | 681 | /* |
eaff8079 | 682 | * This is special! We do not need the spinlock when clearing I_NEW, |
580be083 JK |
683 | * because we're guaranteed that nobody else tries to do anything about |
684 | * the state of the inode when it is locked, as we just created it (so | |
eaff8079 | 685 | * there can be no old holders that haven't tested I_NEW). |
580be083 | 686 | * However we must emit the memory barrier so that other CPUs reliably |
eaff8079 | 687 | * see the clearing of I_NEW after the other inode initialisation has |
580be083 | 688 | * completed. |
1da177e4 | 689 | */ |
580be083 | 690 | smp_mb(); |
eaff8079 CH |
691 | WARN_ON(!(inode->i_state & I_NEW)); |
692 | inode->i_state &= ~I_NEW; | |
1da177e4 LT |
693 | wake_up_inode(inode); |
694 | } | |
1da177e4 LT |
695 | EXPORT_SYMBOL(unlock_new_inode); |
696 | ||
697 | /* | |
698 | * This is called without the inode lock held.. Be careful. | |
699 | * | |
700 | * We no longer cache the sb_flags in i_flags - see fs.h | |
701 | * -- rmk@arm.uk.linux.org | |
702 | */ | |
6b3304b5 MK |
703 | static struct inode *get_new_inode(struct super_block *sb, |
704 | struct hlist_head *head, | |
705 | int (*test)(struct inode *, void *), | |
706 | int (*set)(struct inode *, void *), | |
707 | void *data) | |
1da177e4 | 708 | { |
6b3304b5 | 709 | struct inode *inode; |
1da177e4 LT |
710 | |
711 | inode = alloc_inode(sb); | |
712 | if (inode) { | |
6b3304b5 | 713 | struct inode *old; |
1da177e4 LT |
714 | |
715 | spin_lock(&inode_lock); | |
716 | /* We released the lock, so.. */ | |
717 | old = find_inode(sb, head, test, data); | |
718 | if (!old) { | |
719 | if (set(inode, data)) | |
720 | goto set_failed; | |
721 | ||
8290c35f | 722 | __inode_add_to_lists(sb, head, inode); |
eaff8079 | 723 | inode->i_state = I_NEW; |
1da177e4 LT |
724 | spin_unlock(&inode_lock); |
725 | ||
726 | /* Return the locked inode with I_NEW set, the | |
727 | * caller is responsible for filling in the contents | |
728 | */ | |
729 | return inode; | |
730 | } | |
731 | ||
732 | /* | |
733 | * Uhhuh, somebody else created the same inode under | |
734 | * us. Use the old inode instead of the one we just | |
735 | * allocated. | |
736 | */ | |
737 | __iget(old); | |
738 | spin_unlock(&inode_lock); | |
739 | destroy_inode(inode); | |
740 | inode = old; | |
741 | wait_on_inode(inode); | |
742 | } | |
743 | return inode; | |
744 | ||
745 | set_failed: | |
746 | spin_unlock(&inode_lock); | |
747 | destroy_inode(inode); | |
748 | return NULL; | |
749 | } | |
750 | ||
751 | /* | |
752 | * get_new_inode_fast is the fast path version of get_new_inode, see the | |
753 | * comment at iget_locked for details. | |
754 | */ | |
6b3304b5 MK |
755 | static struct inode *get_new_inode_fast(struct super_block *sb, |
756 | struct hlist_head *head, unsigned long ino) | |
1da177e4 | 757 | { |
6b3304b5 | 758 | struct inode *inode; |
1da177e4 LT |
759 | |
760 | inode = alloc_inode(sb); | |
761 | if (inode) { | |
6b3304b5 | 762 | struct inode *old; |
1da177e4 LT |
763 | |
764 | spin_lock(&inode_lock); | |
765 | /* We released the lock, so.. */ | |
766 | old = find_inode_fast(sb, head, ino); | |
767 | if (!old) { | |
768 | inode->i_ino = ino; | |
8290c35f | 769 | __inode_add_to_lists(sb, head, inode); |
eaff8079 | 770 | inode->i_state = I_NEW; |
1da177e4 LT |
771 | spin_unlock(&inode_lock); |
772 | ||
773 | /* Return the locked inode with I_NEW set, the | |
774 | * caller is responsible for filling in the contents | |
775 | */ | |
776 | return inode; | |
777 | } | |
778 | ||
779 | /* | |
780 | * Uhhuh, somebody else created the same inode under | |
781 | * us. Use the old inode instead of the one we just | |
782 | * allocated. | |
783 | */ | |
784 | __iget(old); | |
785 | spin_unlock(&inode_lock); | |
786 | destroy_inode(inode); | |
787 | inode = old; | |
788 | wait_on_inode(inode); | |
789 | } | |
790 | return inode; | |
791 | } | |
792 | ||
1da177e4 LT |
793 | /** |
794 | * iunique - get a unique inode number | |
795 | * @sb: superblock | |
796 | * @max_reserved: highest reserved inode number | |
797 | * | |
798 | * Obtain an inode number that is unique on the system for a given | |
799 | * superblock. This is used by file systems that have no natural | |
800 | * permanent inode numbering system. An inode number is returned that | |
801 | * is higher than the reserved limit but unique. | |
802 | * | |
803 | * BUGS: | |
804 | * With a large number of inodes live on the file system this function | |
805 | * currently becomes quite slow. | |
806 | */ | |
807 | ino_t iunique(struct super_block *sb, ino_t max_reserved) | |
808 | { | |
866b04fc JL |
809 | /* |
810 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
811 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
812 | * here to attempt to avoid that. | |
813 | */ | |
814 | static unsigned int counter; | |
1da177e4 | 815 | struct inode *inode; |
3361c7be | 816 | struct hlist_head *head; |
1da177e4 | 817 | ino_t res; |
3361c7be | 818 | |
1da177e4 | 819 | spin_lock(&inode_lock); |
3361c7be JL |
820 | do { |
821 | if (counter <= max_reserved) | |
822 | counter = max_reserved + 1; | |
1da177e4 | 823 | res = counter++; |
3361c7be | 824 | head = inode_hashtable + hash(sb, res); |
1da177e4 | 825 | inode = find_inode_fast(sb, head, res); |
3361c7be JL |
826 | } while (inode != NULL); |
827 | spin_unlock(&inode_lock); | |
1da177e4 | 828 | |
3361c7be JL |
829 | return res; |
830 | } | |
1da177e4 LT |
831 | EXPORT_SYMBOL(iunique); |
832 | ||
833 | struct inode *igrab(struct inode *inode) | |
834 | { | |
835 | spin_lock(&inode_lock); | |
a4ffdde6 | 836 | if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) |
1da177e4 LT |
837 | __iget(inode); |
838 | else | |
839 | /* | |
840 | * Handle the case where s_op->clear_inode is not been | |
841 | * called yet, and somebody is calling igrab | |
842 | * while the inode is getting freed. | |
843 | */ | |
844 | inode = NULL; | |
845 | spin_unlock(&inode_lock); | |
846 | return inode; | |
847 | } | |
1da177e4 LT |
848 | EXPORT_SYMBOL(igrab); |
849 | ||
850 | /** | |
851 | * ifind - internal function, you want ilookup5() or iget5(). | |
852 | * @sb: super block of file system to search | |
853 | * @head: the head of the list to search | |
854 | * @test: callback used for comparisons between inodes | |
855 | * @data: opaque data pointer to pass to @test | |
88bd5121 | 856 | * @wait: if true wait for the inode to be unlocked, if false do not |
1da177e4 LT |
857 | * |
858 | * ifind() searches for the inode specified by @data in the inode | |
859 | * cache. This is a generalized version of ifind_fast() for file systems where | |
860 | * the inode number is not sufficient for unique identification of an inode. | |
861 | * | |
862 | * If the inode is in the cache, the inode is returned with an incremented | |
863 | * reference count. | |
864 | * | |
865 | * Otherwise NULL is returned. | |
866 | * | |
867 | * Note, @test is called with the inode_lock held, so can't sleep. | |
868 | */ | |
5d2bea45 | 869 | static struct inode *ifind(struct super_block *sb, |
1da177e4 | 870 | struct hlist_head *head, int (*test)(struct inode *, void *), |
88bd5121 | 871 | void *data, const int wait) |
1da177e4 LT |
872 | { |
873 | struct inode *inode; | |
874 | ||
875 | spin_lock(&inode_lock); | |
876 | inode = find_inode(sb, head, test, data); | |
877 | if (inode) { | |
878 | __iget(inode); | |
879 | spin_unlock(&inode_lock); | |
88bd5121 AA |
880 | if (likely(wait)) |
881 | wait_on_inode(inode); | |
1da177e4 LT |
882 | return inode; |
883 | } | |
884 | spin_unlock(&inode_lock); | |
885 | return NULL; | |
886 | } | |
887 | ||
888 | /** | |
889 | * ifind_fast - internal function, you want ilookup() or iget(). | |
890 | * @sb: super block of file system to search | |
891 | * @head: head of the list to search | |
892 | * @ino: inode number to search for | |
893 | * | |
894 | * ifind_fast() searches for the inode @ino in the inode cache. This is for | |
895 | * file systems where the inode number is sufficient for unique identification | |
896 | * of an inode. | |
897 | * | |
898 | * If the inode is in the cache, the inode is returned with an incremented | |
899 | * reference count. | |
900 | * | |
901 | * Otherwise NULL is returned. | |
902 | */ | |
5d2bea45 | 903 | static struct inode *ifind_fast(struct super_block *sb, |
1da177e4 LT |
904 | struct hlist_head *head, unsigned long ino) |
905 | { | |
906 | struct inode *inode; | |
907 | ||
908 | spin_lock(&inode_lock); | |
909 | inode = find_inode_fast(sb, head, ino); | |
910 | if (inode) { | |
911 | __iget(inode); | |
912 | spin_unlock(&inode_lock); | |
913 | wait_on_inode(inode); | |
914 | return inode; | |
915 | } | |
916 | spin_unlock(&inode_lock); | |
917 | return NULL; | |
918 | } | |
919 | ||
920 | /** | |
88bd5121 | 921 | * ilookup5_nowait - search for an inode in the inode cache |
1da177e4 LT |
922 | * @sb: super block of file system to search |
923 | * @hashval: hash value (usually inode number) to search for | |
924 | * @test: callback used for comparisons between inodes | |
925 | * @data: opaque data pointer to pass to @test | |
926 | * | |
927 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
928 | * @data in the inode cache. This is a generalized version of ilookup() for | |
929 | * file systems where the inode number is not sufficient for unique | |
930 | * identification of an inode. | |
931 | * | |
932 | * If the inode is in the cache, the inode is returned with an incremented | |
88bd5121 AA |
933 | * reference count. Note, the inode lock is not waited upon so you have to be |
934 | * very careful what you do with the returned inode. You probably should be | |
935 | * using ilookup5() instead. | |
936 | * | |
937 | * Otherwise NULL is returned. | |
938 | * | |
939 | * Note, @test is called with the inode_lock held, so can't sleep. | |
940 | */ | |
941 | struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, | |
942 | int (*test)(struct inode *, void *), void *data) | |
943 | { | |
944 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
945 | ||
946 | return ifind(sb, head, test, data, 0); | |
947 | } | |
88bd5121 AA |
948 | EXPORT_SYMBOL(ilookup5_nowait); |
949 | ||
950 | /** | |
951 | * ilookup5 - search for an inode in the inode cache | |
952 | * @sb: super block of file system to search | |
953 | * @hashval: hash value (usually inode number) to search for | |
954 | * @test: callback used for comparisons between inodes | |
955 | * @data: opaque data pointer to pass to @test | |
956 | * | |
957 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
958 | * @data in the inode cache. This is a generalized version of ilookup() for | |
959 | * file systems where the inode number is not sufficient for unique | |
960 | * identification of an inode. | |
961 | * | |
962 | * If the inode is in the cache, the inode lock is waited upon and the inode is | |
963 | * returned with an incremented reference count. | |
1da177e4 LT |
964 | * |
965 | * Otherwise NULL is returned. | |
966 | * | |
967 | * Note, @test is called with the inode_lock held, so can't sleep. | |
968 | */ | |
969 | struct inode *ilookup5(struct super_block *sb, unsigned long hashval, | |
970 | int (*test)(struct inode *, void *), void *data) | |
971 | { | |
972 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
973 | ||
88bd5121 | 974 | return ifind(sb, head, test, data, 1); |
1da177e4 | 975 | } |
1da177e4 LT |
976 | EXPORT_SYMBOL(ilookup5); |
977 | ||
978 | /** | |
979 | * ilookup - search for an inode in the inode cache | |
980 | * @sb: super block of file system to search | |
981 | * @ino: inode number to search for | |
982 | * | |
983 | * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache. | |
984 | * This is for file systems where the inode number is sufficient for unique | |
985 | * identification of an inode. | |
986 | * | |
987 | * If the inode is in the cache, the inode is returned with an incremented | |
988 | * reference count. | |
989 | * | |
990 | * Otherwise NULL is returned. | |
991 | */ | |
992 | struct inode *ilookup(struct super_block *sb, unsigned long ino) | |
993 | { | |
994 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
995 | ||
996 | return ifind_fast(sb, head, ino); | |
997 | } | |
1da177e4 LT |
998 | EXPORT_SYMBOL(ilookup); |
999 | ||
1000 | /** | |
1001 | * iget5_locked - obtain an inode from a mounted file system | |
1002 | * @sb: super block of file system | |
1003 | * @hashval: hash value (usually inode number) to get | |
1004 | * @test: callback used for comparisons between inodes | |
1005 | * @set: callback used to initialize a new struct inode | |
1006 | * @data: opaque data pointer to pass to @test and @set | |
1007 | * | |
1da177e4 LT |
1008 | * iget5_locked() uses ifind() to search for the inode specified by @hashval |
1009 | * and @data in the inode cache and if present it is returned with an increased | |
1010 | * reference count. This is a generalized version of iget_locked() for file | |
1011 | * systems where the inode number is not sufficient for unique identification | |
1012 | * of an inode. | |
1013 | * | |
1014 | * If the inode is not in cache, get_new_inode() is called to allocate a new | |
1015 | * inode and this is returned locked, hashed, and with the I_NEW flag set. The | |
1016 | * file system gets to fill it in before unlocking it via unlock_new_inode(). | |
1017 | * | |
1018 | * Note both @test and @set are called with the inode_lock held, so can't sleep. | |
1019 | */ | |
1020 | struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, | |
1021 | int (*test)(struct inode *, void *), | |
1022 | int (*set)(struct inode *, void *), void *data) | |
1023 | { | |
1024 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
1025 | struct inode *inode; | |
1026 | ||
88bd5121 | 1027 | inode = ifind(sb, head, test, data, 1); |
1da177e4 LT |
1028 | if (inode) |
1029 | return inode; | |
1030 | /* | |
1031 | * get_new_inode() will do the right thing, re-trying the search | |
1032 | * in case it had to block at any point. | |
1033 | */ | |
1034 | return get_new_inode(sb, head, test, set, data); | |
1035 | } | |
1da177e4 LT |
1036 | EXPORT_SYMBOL(iget5_locked); |
1037 | ||
1038 | /** | |
1039 | * iget_locked - obtain an inode from a mounted file system | |
1040 | * @sb: super block of file system | |
1041 | * @ino: inode number to get | |
1042 | * | |
1da177e4 LT |
1043 | * iget_locked() uses ifind_fast() to search for the inode specified by @ino in |
1044 | * the inode cache and if present it is returned with an increased reference | |
1045 | * count. This is for file systems where the inode number is sufficient for | |
1046 | * unique identification of an inode. | |
1047 | * | |
1048 | * If the inode is not in cache, get_new_inode_fast() is called to allocate a | |
1049 | * new inode and this is returned locked, hashed, and with the I_NEW flag set. | |
1050 | * The file system gets to fill it in before unlocking it via | |
1051 | * unlock_new_inode(). | |
1052 | */ | |
1053 | struct inode *iget_locked(struct super_block *sb, unsigned long ino) | |
1054 | { | |
1055 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
1056 | struct inode *inode; | |
1057 | ||
1058 | inode = ifind_fast(sb, head, ino); | |
1059 | if (inode) | |
1060 | return inode; | |
1061 | /* | |
1062 | * get_new_inode_fast() will do the right thing, re-trying the search | |
1063 | * in case it had to block at any point. | |
1064 | */ | |
1065 | return get_new_inode_fast(sb, head, ino); | |
1066 | } | |
1da177e4 LT |
1067 | EXPORT_SYMBOL(iget_locked); |
1068 | ||
261bca86 AV |
1069 | int insert_inode_locked(struct inode *inode) |
1070 | { | |
1071 | struct super_block *sb = inode->i_sb; | |
1072 | ino_t ino = inode->i_ino; | |
1073 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
261bca86 | 1074 | |
eaff8079 | 1075 | inode->i_state |= I_NEW; |
261bca86 | 1076 | while (1) { |
72a43d63 AV |
1077 | struct hlist_node *node; |
1078 | struct inode *old = NULL; | |
261bca86 | 1079 | spin_lock(&inode_lock); |
72a43d63 AV |
1080 | hlist_for_each_entry(old, node, head, i_hash) { |
1081 | if (old->i_ino != ino) | |
1082 | continue; | |
1083 | if (old->i_sb != sb) | |
1084 | continue; | |
a4ffdde6 | 1085 | if (old->i_state & (I_FREEING|I_WILL_FREE)) |
72a43d63 AV |
1086 | continue; |
1087 | break; | |
1088 | } | |
1089 | if (likely(!node)) { | |
261bca86 AV |
1090 | hlist_add_head(&inode->i_hash, head); |
1091 | spin_unlock(&inode_lock); | |
1092 | return 0; | |
1093 | } | |
1094 | __iget(old); | |
1095 | spin_unlock(&inode_lock); | |
1096 | wait_on_inode(old); | |
1097 | if (unlikely(!hlist_unhashed(&old->i_hash))) { | |
1098 | iput(old); | |
1099 | return -EBUSY; | |
1100 | } | |
1101 | iput(old); | |
1102 | } | |
1103 | } | |
261bca86 AV |
1104 | EXPORT_SYMBOL(insert_inode_locked); |
1105 | ||
1106 | int insert_inode_locked4(struct inode *inode, unsigned long hashval, | |
1107 | int (*test)(struct inode *, void *), void *data) | |
1108 | { | |
1109 | struct super_block *sb = inode->i_sb; | |
1110 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
261bca86 | 1111 | |
eaff8079 | 1112 | inode->i_state |= I_NEW; |
261bca86 AV |
1113 | |
1114 | while (1) { | |
72a43d63 AV |
1115 | struct hlist_node *node; |
1116 | struct inode *old = NULL; | |
1117 | ||
261bca86 | 1118 | spin_lock(&inode_lock); |
72a43d63 AV |
1119 | hlist_for_each_entry(old, node, head, i_hash) { |
1120 | if (old->i_sb != sb) | |
1121 | continue; | |
1122 | if (!test(old, data)) | |
1123 | continue; | |
a4ffdde6 | 1124 | if (old->i_state & (I_FREEING|I_WILL_FREE)) |
72a43d63 AV |
1125 | continue; |
1126 | break; | |
1127 | } | |
1128 | if (likely(!node)) { | |
261bca86 AV |
1129 | hlist_add_head(&inode->i_hash, head); |
1130 | spin_unlock(&inode_lock); | |
1131 | return 0; | |
1132 | } | |
1133 | __iget(old); | |
1134 | spin_unlock(&inode_lock); | |
1135 | wait_on_inode(old); | |
1136 | if (unlikely(!hlist_unhashed(&old->i_hash))) { | |
1137 | iput(old); | |
1138 | return -EBUSY; | |
1139 | } | |
1140 | iput(old); | |
1141 | } | |
1142 | } | |
261bca86 AV |
1143 | EXPORT_SYMBOL(insert_inode_locked4); |
1144 | ||
1da177e4 LT |
1145 | /** |
1146 | * __insert_inode_hash - hash an inode | |
1147 | * @inode: unhashed inode | |
1148 | * @hashval: unsigned long value used to locate this object in the | |
1149 | * inode_hashtable. | |
1150 | * | |
1151 | * Add an inode to the inode hash for this superblock. | |
1152 | */ | |
1153 | void __insert_inode_hash(struct inode *inode, unsigned long hashval) | |
1154 | { | |
1155 | struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval); | |
1156 | spin_lock(&inode_lock); | |
1157 | hlist_add_head(&inode->i_hash, head); | |
1158 | spin_unlock(&inode_lock); | |
1159 | } | |
1da177e4 LT |
1160 | EXPORT_SYMBOL(__insert_inode_hash); |
1161 | ||
1162 | /** | |
1163 | * remove_inode_hash - remove an inode from the hash | |
1164 | * @inode: inode to unhash | |
1165 | * | |
1166 | * Remove an inode from the superblock. | |
1167 | */ | |
1168 | void remove_inode_hash(struct inode *inode) | |
1169 | { | |
1170 | spin_lock(&inode_lock); | |
1171 | hlist_del_init(&inode->i_hash); | |
1172 | spin_unlock(&inode_lock); | |
1173 | } | |
1da177e4 LT |
1174 | EXPORT_SYMBOL(remove_inode_hash); |
1175 | ||
45321ac5 AV |
1176 | int generic_delete_inode(struct inode *inode) |
1177 | { | |
1178 | return 1; | |
1179 | } | |
1180 | EXPORT_SYMBOL(generic_delete_inode); | |
1181 | ||
1da177e4 | 1182 | /* |
45321ac5 AV |
1183 | * Normal UNIX filesystem behaviour: delete the |
1184 | * inode when the usage count drops to zero, and | |
1185 | * i_nlink is zero. | |
1da177e4 | 1186 | */ |
45321ac5 | 1187 | int generic_drop_inode(struct inode *inode) |
1da177e4 | 1188 | { |
45321ac5 | 1189 | return !inode->i_nlink || hlist_unhashed(&inode->i_hash); |
1da177e4 | 1190 | } |
45321ac5 | 1191 | EXPORT_SYMBOL_GPL(generic_drop_inode); |
1da177e4 | 1192 | |
45321ac5 AV |
1193 | /* |
1194 | * Called when we're dropping the last reference | |
1195 | * to an inode. | |
22fe4042 | 1196 | * |
45321ac5 AV |
1197 | * Call the FS "drop_inode()" function, defaulting to |
1198 | * the legacy UNIX filesystem behaviour. If it tells | |
1199 | * us to evict inode, do so. Otherwise, retain inode | |
1200 | * in cache if fs is alive, sync and evict if fs is | |
1201 | * shutting down. | |
22fe4042 | 1202 | */ |
45321ac5 | 1203 | static void iput_final(struct inode *inode) |
1da177e4 LT |
1204 | { |
1205 | struct super_block *sb = inode->i_sb; | |
45321ac5 AV |
1206 | const struct super_operations *op = inode->i_sb->s_op; |
1207 | int drop; | |
1208 | ||
1209 | if (op && op->drop_inode) | |
1210 | drop = op->drop_inode(inode); | |
1211 | else | |
1212 | drop = generic_drop_inode(inode); | |
1da177e4 | 1213 | |
45321ac5 | 1214 | if (!drop) { |
1c0eeaf5 | 1215 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) |
1da177e4 LT |
1216 | list_move(&inode->i_list, &inode_unused); |
1217 | inodes_stat.nr_unused++; | |
acb0c854 | 1218 | if (sb->s_flags & MS_ACTIVE) { |
991114c6 | 1219 | spin_unlock(&inode_lock); |
45321ac5 | 1220 | return; |
991114c6 | 1221 | } |
7ef0d737 | 1222 | WARN_ON(inode->i_state & I_NEW); |
991114c6 AV |
1223 | inode->i_state |= I_WILL_FREE; |
1224 | spin_unlock(&inode_lock); | |
1da177e4 LT |
1225 | write_inode_now(inode, 1); |
1226 | spin_lock(&inode_lock); | |
7ef0d737 | 1227 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1228 | inode->i_state &= ~I_WILL_FREE; |
1da177e4 LT |
1229 | inodes_stat.nr_unused--; |
1230 | hlist_del_init(&inode->i_hash); | |
1231 | } | |
1232 | list_del_init(&inode->i_list); | |
1233 | list_del_init(&inode->i_sb_list); | |
7ef0d737 | 1234 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1235 | inode->i_state |= I_FREEING; |
1da177e4 LT |
1236 | inodes_stat.nr_inodes--; |
1237 | spin_unlock(&inode_lock); | |
644da596 | 1238 | evict(inode); |
45321ac5 AV |
1239 | spin_lock(&inode_lock); |
1240 | hlist_del_init(&inode->i_hash); | |
1241 | spin_unlock(&inode_lock); | |
7f04c26d | 1242 | wake_up_inode(inode); |
45321ac5 | 1243 | BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); |
1da177e4 LT |
1244 | destroy_inode(inode); |
1245 | } | |
1246 | ||
1da177e4 | 1247 | /** |
6b3304b5 | 1248 | * iput - put an inode |
1da177e4 LT |
1249 | * @inode: inode to put |
1250 | * | |
1251 | * Puts an inode, dropping its usage count. If the inode use count hits | |
1252 | * zero, the inode is then freed and may also be destroyed. | |
1253 | * | |
1254 | * Consequently, iput() can sleep. | |
1255 | */ | |
1256 | void iput(struct inode *inode) | |
1257 | { | |
1258 | if (inode) { | |
a4ffdde6 | 1259 | BUG_ON(inode->i_state & I_CLEAR); |
1da177e4 | 1260 | |
1da177e4 LT |
1261 | if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) |
1262 | iput_final(inode); | |
1263 | } | |
1264 | } | |
1da177e4 LT |
1265 | EXPORT_SYMBOL(iput); |
1266 | ||
1267 | /** | |
1268 | * bmap - find a block number in a file | |
1269 | * @inode: inode of file | |
1270 | * @block: block to find | |
1271 | * | |
1272 | * Returns the block number on the device holding the inode that | |
1273 | * is the disk block number for the block of the file requested. | |
1274 | * That is, asked for block 4 of inode 1 the function will return the | |
6b3304b5 | 1275 | * disk block relative to the disk start that holds that block of the |
1da177e4 LT |
1276 | * file. |
1277 | */ | |
6b3304b5 | 1278 | sector_t bmap(struct inode *inode, sector_t block) |
1da177e4 LT |
1279 | { |
1280 | sector_t res = 0; | |
1281 | if (inode->i_mapping->a_ops->bmap) | |
1282 | res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); | |
1283 | return res; | |
1284 | } | |
1da177e4 LT |
1285 | EXPORT_SYMBOL(bmap); |
1286 | ||
11ff6f05 MG |
1287 | /* |
1288 | * With relative atime, only update atime if the previous atime is | |
1289 | * earlier than either the ctime or mtime or if at least a day has | |
1290 | * passed since the last atime update. | |
1291 | */ | |
1292 | static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, | |
1293 | struct timespec now) | |
1294 | { | |
1295 | ||
1296 | if (!(mnt->mnt_flags & MNT_RELATIME)) | |
1297 | return 1; | |
1298 | /* | |
1299 | * Is mtime younger than atime? If yes, update atime: | |
1300 | */ | |
1301 | if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0) | |
1302 | return 1; | |
1303 | /* | |
1304 | * Is ctime younger than atime? If yes, update atime: | |
1305 | */ | |
1306 | if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0) | |
1307 | return 1; | |
1308 | ||
1309 | /* | |
1310 | * Is the previous atime value older than a day? If yes, | |
1311 | * update atime: | |
1312 | */ | |
1313 | if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60) | |
1314 | return 1; | |
1315 | /* | |
1316 | * Good, we can skip the atime update: | |
1317 | */ | |
1318 | return 0; | |
1319 | } | |
1320 | ||
1da177e4 | 1321 | /** |
869243a0 CH |
1322 | * touch_atime - update the access time |
1323 | * @mnt: mount the inode is accessed on | |
7045f37b | 1324 | * @dentry: dentry accessed |
1da177e4 LT |
1325 | * |
1326 | * Update the accessed time on an inode and mark it for writeback. | |
1327 | * This function automatically handles read only file systems and media, | |
1328 | * as well as the "noatime" flag and inode specific "noatime" markers. | |
1329 | */ | |
869243a0 | 1330 | void touch_atime(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4 | 1331 | { |
869243a0 | 1332 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
1333 | struct timespec now; |
1334 | ||
cdb70f3f | 1335 | if (inode->i_flags & S_NOATIME) |
b12536c2 | 1336 | return; |
37756ced | 1337 | if (IS_NOATIME(inode)) |
b12536c2 | 1338 | return; |
b2276138 | 1339 | if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1340 | return; |
47ae32d6 | 1341 | |
cdb70f3f | 1342 | if (mnt->mnt_flags & MNT_NOATIME) |
b12536c2 | 1343 | return; |
cdb70f3f | 1344 | if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1345 | return; |
1da177e4 LT |
1346 | |
1347 | now = current_fs_time(inode->i_sb); | |
11ff6f05 MG |
1348 | |
1349 | if (!relatime_need_update(mnt, inode, now)) | |
b12536c2 | 1350 | return; |
11ff6f05 | 1351 | |
47ae32d6 | 1352 | if (timespec_equal(&inode->i_atime, &now)) |
b12536c2 AK |
1353 | return; |
1354 | ||
1355 | if (mnt_want_write(mnt)) | |
1356 | return; | |
47ae32d6 VH |
1357 | |
1358 | inode->i_atime = now; | |
1359 | mark_inode_dirty_sync(inode); | |
cdb70f3f | 1360 | mnt_drop_write(mnt); |
1da177e4 | 1361 | } |
869243a0 | 1362 | EXPORT_SYMBOL(touch_atime); |
1da177e4 LT |
1363 | |
1364 | /** | |
870f4817 CH |
1365 | * file_update_time - update mtime and ctime time |
1366 | * @file: file accessed | |
1da177e4 | 1367 | * |
870f4817 CH |
1368 | * Update the mtime and ctime members of an inode and mark the inode |
1369 | * for writeback. Note that this function is meant exclusively for | |
1370 | * usage in the file write path of filesystems, and filesystems may | |
1371 | * choose to explicitly ignore update via this function with the | |
2eadfc0e | 1372 | * S_NOCMTIME inode flag, e.g. for network filesystem where these |
870f4817 | 1373 | * timestamps are handled by the server. |
1da177e4 LT |
1374 | */ |
1375 | ||
870f4817 | 1376 | void file_update_time(struct file *file) |
1da177e4 | 1377 | { |
0f7fc9e4 | 1378 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 | 1379 | struct timespec now; |
ce06e0b2 | 1380 | enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0; |
1da177e4 | 1381 | |
ce06e0b2 | 1382 | /* First try to exhaust all avenues to not sync */ |
1da177e4 LT |
1383 | if (IS_NOCMTIME(inode)) |
1384 | return; | |
20ddee2c | 1385 | |
1da177e4 | 1386 | now = current_fs_time(inode->i_sb); |
ce06e0b2 AK |
1387 | if (!timespec_equal(&inode->i_mtime, &now)) |
1388 | sync_it = S_MTIME; | |
1da177e4 | 1389 | |
ce06e0b2 AK |
1390 | if (!timespec_equal(&inode->i_ctime, &now)) |
1391 | sync_it |= S_CTIME; | |
870f4817 | 1392 | |
ce06e0b2 AK |
1393 | if (IS_I_VERSION(inode)) |
1394 | sync_it |= S_VERSION; | |
7a224228 | 1395 | |
ce06e0b2 AK |
1396 | if (!sync_it) |
1397 | return; | |
1398 | ||
1399 | /* Finally allowed to write? Takes lock. */ | |
1400 | if (mnt_want_write_file(file)) | |
1401 | return; | |
1402 | ||
1403 | /* Only change inode inside the lock region */ | |
1404 | if (sync_it & S_VERSION) | |
1405 | inode_inc_iversion(inode); | |
1406 | if (sync_it & S_CTIME) | |
1407 | inode->i_ctime = now; | |
1408 | if (sync_it & S_MTIME) | |
1409 | inode->i_mtime = now; | |
1410 | mark_inode_dirty_sync(inode); | |
20ddee2c | 1411 | mnt_drop_write(file->f_path.mnt); |
1da177e4 | 1412 | } |
870f4817 | 1413 | EXPORT_SYMBOL(file_update_time); |
1da177e4 LT |
1414 | |
1415 | int inode_needs_sync(struct inode *inode) | |
1416 | { | |
1417 | if (IS_SYNC(inode)) | |
1418 | return 1; | |
1419 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) | |
1420 | return 1; | |
1421 | return 0; | |
1422 | } | |
1da177e4 LT |
1423 | EXPORT_SYMBOL(inode_needs_sync); |
1424 | ||
1da177e4 LT |
1425 | int inode_wait(void *word) |
1426 | { | |
1427 | schedule(); | |
1428 | return 0; | |
1429 | } | |
d44dab8d | 1430 | EXPORT_SYMBOL(inode_wait); |
1da177e4 LT |
1431 | |
1432 | /* | |
168a9fd6 MS |
1433 | * If we try to find an inode in the inode hash while it is being |
1434 | * deleted, we have to wait until the filesystem completes its | |
1435 | * deletion before reporting that it isn't found. This function waits | |
1436 | * until the deletion _might_ have completed. Callers are responsible | |
1437 | * to recheck inode state. | |
1438 | * | |
eaff8079 | 1439 | * It doesn't matter if I_NEW is not set initially, a call to |
168a9fd6 MS |
1440 | * wake_up_inode() after removing from the hash list will DTRT. |
1441 | * | |
1da177e4 LT |
1442 | * This is called with inode_lock held. |
1443 | */ | |
1444 | static void __wait_on_freeing_inode(struct inode *inode) | |
1445 | { | |
1446 | wait_queue_head_t *wq; | |
eaff8079 CH |
1447 | DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); |
1448 | wq = bit_waitqueue(&inode->i_state, __I_NEW); | |
1da177e4 LT |
1449 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); |
1450 | spin_unlock(&inode_lock); | |
1451 | schedule(); | |
1452 | finish_wait(wq, &wait.wait); | |
1453 | spin_lock(&inode_lock); | |
1454 | } | |
1455 | ||
1da177e4 LT |
1456 | static __initdata unsigned long ihash_entries; |
1457 | static int __init set_ihash_entries(char *str) | |
1458 | { | |
1459 | if (!str) | |
1460 | return 0; | |
1461 | ihash_entries = simple_strtoul(str, &str, 0); | |
1462 | return 1; | |
1463 | } | |
1464 | __setup("ihash_entries=", set_ihash_entries); | |
1465 | ||
1466 | /* | |
1467 | * Initialize the waitqueues and inode hash table. | |
1468 | */ | |
1469 | void __init inode_init_early(void) | |
1470 | { | |
1471 | int loop; | |
1472 | ||
1473 | /* If hashes are distributed across NUMA nodes, defer | |
1474 | * hash allocation until vmalloc space is available. | |
1475 | */ | |
1476 | if (hashdist) | |
1477 | return; | |
1478 | ||
1479 | inode_hashtable = | |
1480 | alloc_large_system_hash("Inode-cache", | |
1481 | sizeof(struct hlist_head), | |
1482 | ihash_entries, | |
1483 | 14, | |
1484 | HASH_EARLY, | |
1485 | &i_hash_shift, | |
1486 | &i_hash_mask, | |
1487 | 0); | |
1488 | ||
1489 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1490 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1491 | } | |
1492 | ||
74bf17cf | 1493 | void __init inode_init(void) |
1da177e4 LT |
1494 | { |
1495 | int loop; | |
1496 | ||
1497 | /* inode slab cache */ | |
b0196009 PJ |
1498 | inode_cachep = kmem_cache_create("inode_cache", |
1499 | sizeof(struct inode), | |
1500 | 0, | |
1501 | (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| | |
1502 | SLAB_MEM_SPREAD), | |
20c2df83 | 1503 | init_once); |
8e1f936b | 1504 | register_shrinker(&icache_shrinker); |
1da177e4 LT |
1505 | |
1506 | /* Hash may have been set up in inode_init_early */ | |
1507 | if (!hashdist) | |
1508 | return; | |
1509 | ||
1510 | inode_hashtable = | |
1511 | alloc_large_system_hash("Inode-cache", | |
1512 | sizeof(struct hlist_head), | |
1513 | ihash_entries, | |
1514 | 14, | |
1515 | 0, | |
1516 | &i_hash_shift, | |
1517 | &i_hash_mask, | |
1518 | 0); | |
1519 | ||
1520 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1521 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1522 | } | |
1523 | ||
1524 | void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) | |
1525 | { | |
1526 | inode->i_mode = mode; | |
1527 | if (S_ISCHR(mode)) { | |
1528 | inode->i_fop = &def_chr_fops; | |
1529 | inode->i_rdev = rdev; | |
1530 | } else if (S_ISBLK(mode)) { | |
1531 | inode->i_fop = &def_blk_fops; | |
1532 | inode->i_rdev = rdev; | |
1533 | } else if (S_ISFIFO(mode)) | |
1534 | inode->i_fop = &def_fifo_fops; | |
1535 | else if (S_ISSOCK(mode)) | |
1536 | inode->i_fop = &bad_sock_fops; | |
1537 | else | |
af0d9ae8 MK |
1538 | printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for" |
1539 | " inode %s:%lu\n", mode, inode->i_sb->s_id, | |
1540 | inode->i_ino); | |
1da177e4 LT |
1541 | } |
1542 | EXPORT_SYMBOL(init_special_inode); | |
a1bd120d DM |
1543 | |
1544 | /** | |
1545 | * Init uid,gid,mode for new inode according to posix standards | |
1546 | * @inode: New inode | |
1547 | * @dir: Directory inode | |
1548 | * @mode: mode of the new inode | |
1549 | */ | |
1550 | void inode_init_owner(struct inode *inode, const struct inode *dir, | |
1551 | mode_t mode) | |
1552 | { | |
1553 | inode->i_uid = current_fsuid(); | |
1554 | if (dir && dir->i_mode & S_ISGID) { | |
1555 | inode->i_gid = dir->i_gid; | |
1556 | if (S_ISDIR(mode)) | |
1557 | mode |= S_ISGID; | |
1558 | } else | |
1559 | inode->i_gid = current_fsgid(); | |
1560 | inode->i_mode = mode; | |
1561 | } | |
1562 | EXPORT_SYMBOL(inode_init_owner); |