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 | |
1da177e4 LT |
31 | * - invalidate_bdev |
32 | * | |
33 | * FIXME: remove all knowledge of the buffer layer from this file | |
34 | */ | |
35 | #include <linux/buffer_head.h> | |
36 | ||
37 | /* | |
38 | * New inode.c implementation. | |
39 | * | |
40 | * This implementation has the basic premise of trying | |
41 | * to be extremely low-overhead and SMP-safe, yet be | |
42 | * simple enough to be "obviously correct". | |
43 | * | |
44 | * Famous last words. | |
45 | */ | |
46 | ||
47 | /* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */ | |
48 | ||
49 | /* #define INODE_PARANOIA 1 */ | |
50 | /* #define INODE_DEBUG 1 */ | |
51 | ||
52 | /* | |
53 | * Inode lookup is no longer as critical as it used to be: | |
54 | * most of the lookups are going to be through the dcache. | |
55 | */ | |
56 | #define I_HASHBITS i_hash_shift | |
57 | #define I_HASHMASK i_hash_mask | |
58 | ||
fa3536cc ED |
59 | static unsigned int i_hash_mask __read_mostly; |
60 | static unsigned int i_hash_shift __read_mostly; | |
1da177e4 LT |
61 | |
62 | /* | |
63 | * Each inode can be on two separate lists. One is | |
64 | * the hash list of the inode, used for lookups. The | |
65 | * other linked list is the "type" list: | |
66 | * "in_use" - valid inode, i_count > 0, i_nlink > 0 | |
67 | * "dirty" - as "in_use" but also dirty | |
68 | * "unused" - valid inode, i_count = 0 | |
69 | * | |
70 | * A "dirty" list is maintained for each super block, | |
71 | * allowing for low-overhead inode sync() operations. | |
72 | */ | |
73 | ||
7ccf19a8 | 74 | static LIST_HEAD(inode_lru); |
fa3536cc | 75 | static struct hlist_head *inode_hashtable __read_mostly; |
1da177e4 LT |
76 | |
77 | /* | |
78 | * A simple spinlock to protect the list manipulations. | |
79 | * | |
80 | * NOTE! You also have to own the lock if you change | |
81 | * the i_state of an inode while it is in use.. | |
82 | */ | |
83 | DEFINE_SPINLOCK(inode_lock); | |
84 | ||
85 | /* | |
88e0fbc4 | 86 | * iprune_sem provides exclusion between the kswapd or try_to_free_pages |
1da177e4 LT |
87 | * icache shrinking path, and the umount path. Without this exclusion, |
88 | * by the time prune_icache calls iput for the inode whose pages it has | |
89 | * been invalidating, or by the time it calls clear_inode & destroy_inode | |
90 | * from its final dispose_list, the struct super_block they refer to | |
91 | * (for inode->i_sb->s_op) may already have been freed and reused. | |
88e0fbc4 NP |
92 | * |
93 | * We make this an rwsem because the fastpath is icache shrinking. In | |
94 | * some cases a filesystem may be doing a significant amount of work in | |
95 | * its inode reclaim code, so this should improve parallelism. | |
1da177e4 | 96 | */ |
88e0fbc4 | 97 | static DECLARE_RWSEM(iprune_sem); |
1da177e4 LT |
98 | |
99 | /* | |
100 | * Statistics gathering.. | |
101 | */ | |
102 | struct inodes_stat_t inodes_stat; | |
103 | ||
cffbc8aa DC |
104 | static struct percpu_counter nr_inodes __cacheline_aligned_in_smp; |
105 | static struct percpu_counter nr_inodes_unused __cacheline_aligned_in_smp; | |
106 | ||
6b3304b5 | 107 | static struct kmem_cache *inode_cachep __read_mostly; |
1da177e4 | 108 | |
cffbc8aa DC |
109 | static inline int get_nr_inodes(void) |
110 | { | |
111 | return percpu_counter_sum_positive(&nr_inodes); | |
112 | } | |
113 | ||
114 | static inline int get_nr_inodes_unused(void) | |
115 | { | |
116 | return percpu_counter_sum_positive(&nr_inodes_unused); | |
117 | } | |
118 | ||
119 | int get_nr_dirty_inodes(void) | |
120 | { | |
121 | int nr_dirty = get_nr_inodes() - get_nr_inodes_unused(); | |
122 | return nr_dirty > 0 ? nr_dirty : 0; | |
123 | ||
124 | } | |
125 | ||
126 | /* | |
127 | * Handle nr_inode sysctl | |
128 | */ | |
129 | #ifdef CONFIG_SYSCTL | |
130 | int proc_nr_inodes(ctl_table *table, int write, | |
131 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
132 | { | |
133 | inodes_stat.nr_inodes = get_nr_inodes(); | |
134 | inodes_stat.nr_unused = get_nr_inodes_unused(); | |
135 | return proc_dointvec(table, write, buffer, lenp, ppos); | |
136 | } | |
137 | #endif | |
138 | ||
1c0eeaf5 JE |
139 | static void wake_up_inode(struct inode *inode) |
140 | { | |
141 | /* | |
142 | * Prevent speculative execution through spin_unlock(&inode_lock); | |
143 | */ | |
144 | smp_mb(); | |
eaff8079 | 145 | wake_up_bit(&inode->i_state, __I_NEW); |
1c0eeaf5 JE |
146 | } |
147 | ||
2cb1599f DC |
148 | /** |
149 | * inode_init_always - perform inode structure intialisation | |
0bc02f3f RD |
150 | * @sb: superblock inode belongs to |
151 | * @inode: inode to initialise | |
2cb1599f DC |
152 | * |
153 | * These are initializations that need to be done on every inode | |
154 | * allocation as the fields are not initialised by slab allocation. | |
155 | */ | |
54e34621 | 156 | int inode_init_always(struct super_block *sb, struct inode *inode) |
1da177e4 | 157 | { |
f5e54d6e | 158 | static const struct address_space_operations empty_aops; |
6e1d5dcc | 159 | static const struct inode_operations empty_iops; |
99ac48f5 | 160 | static const struct file_operations empty_fops; |
6b3304b5 | 161 | struct address_space *const mapping = &inode->i_data; |
2cb1599f DC |
162 | |
163 | inode->i_sb = sb; | |
164 | inode->i_blkbits = sb->s_blocksize_bits; | |
165 | inode->i_flags = 0; | |
166 | atomic_set(&inode->i_count, 1); | |
167 | inode->i_op = &empty_iops; | |
168 | inode->i_fop = &empty_fops; | |
169 | inode->i_nlink = 1; | |
56ff5efa AV |
170 | inode->i_uid = 0; |
171 | inode->i_gid = 0; | |
2cb1599f DC |
172 | atomic_set(&inode->i_writecount, 0); |
173 | inode->i_size = 0; | |
174 | inode->i_blocks = 0; | |
175 | inode->i_bytes = 0; | |
176 | inode->i_generation = 0; | |
1da177e4 | 177 | #ifdef CONFIG_QUOTA |
2cb1599f | 178 | memset(&inode->i_dquot, 0, sizeof(inode->i_dquot)); |
1da177e4 | 179 | #endif |
2cb1599f DC |
180 | inode->i_pipe = NULL; |
181 | inode->i_bdev = NULL; | |
182 | inode->i_cdev = NULL; | |
183 | inode->i_rdev = 0; | |
184 | inode->dirtied_when = 0; | |
6146f0d5 MZ |
185 | |
186 | if (security_inode_alloc(inode)) | |
54e34621 | 187 | goto out; |
2cb1599f DC |
188 | spin_lock_init(&inode->i_lock); |
189 | lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key); | |
190 | ||
191 | mutex_init(&inode->i_mutex); | |
192 | lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key); | |
193 | ||
194 | init_rwsem(&inode->i_alloc_sem); | |
195 | lockdep_set_class(&inode->i_alloc_sem, &sb->s_type->i_alloc_sem_key); | |
196 | ||
197 | mapping->a_ops = &empty_aops; | |
198 | mapping->host = inode; | |
199 | mapping->flags = 0; | |
3c1d4378 | 200 | mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE); |
2cb1599f DC |
201 | mapping->assoc_mapping = NULL; |
202 | mapping->backing_dev_info = &default_backing_dev_info; | |
203 | mapping->writeback_index = 0; | |
204 | ||
205 | /* | |
206 | * If the block_device provides a backing_dev_info for client | |
207 | * inodes then use that. Otherwise the inode share the bdev's | |
208 | * backing_dev_info. | |
209 | */ | |
210 | if (sb->s_bdev) { | |
211 | struct backing_dev_info *bdi; | |
212 | ||
2c96ce9f | 213 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; |
2cb1599f DC |
214 | mapping->backing_dev_info = bdi; |
215 | } | |
216 | inode->i_private = NULL; | |
217 | inode->i_mapping = mapping; | |
f19d4a8f AV |
218 | #ifdef CONFIG_FS_POSIX_ACL |
219 | inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; | |
220 | #endif | |
2cb1599f | 221 | |
3be25f49 EP |
222 | #ifdef CONFIG_FSNOTIFY |
223 | inode->i_fsnotify_mask = 0; | |
224 | #endif | |
225 | ||
cffbc8aa DC |
226 | percpu_counter_inc(&nr_inodes); |
227 | ||
54e34621 | 228 | return 0; |
54e34621 CH |
229 | out: |
230 | return -ENOMEM; | |
1da177e4 | 231 | } |
2cb1599f DC |
232 | EXPORT_SYMBOL(inode_init_always); |
233 | ||
234 | static struct inode *alloc_inode(struct super_block *sb) | |
235 | { | |
236 | struct inode *inode; | |
237 | ||
238 | if (sb->s_op->alloc_inode) | |
239 | inode = sb->s_op->alloc_inode(sb); | |
240 | else | |
241 | inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL); | |
242 | ||
54e34621 CH |
243 | if (!inode) |
244 | return NULL; | |
245 | ||
246 | if (unlikely(inode_init_always(sb, inode))) { | |
247 | if (inode->i_sb->s_op->destroy_inode) | |
248 | inode->i_sb->s_op->destroy_inode(inode); | |
249 | else | |
250 | kmem_cache_free(inode_cachep, inode); | |
251 | return NULL; | |
252 | } | |
253 | ||
254 | return inode; | |
2cb1599f | 255 | } |
1da177e4 | 256 | |
2e00c97e | 257 | void __destroy_inode(struct inode *inode) |
1da177e4 | 258 | { |
b7542f8c | 259 | BUG_ON(inode_has_buffers(inode)); |
1da177e4 | 260 | security_inode_free(inode); |
3be25f49 | 261 | fsnotify_inode_delete(inode); |
f19d4a8f AV |
262 | #ifdef CONFIG_FS_POSIX_ACL |
263 | if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED) | |
264 | posix_acl_release(inode->i_acl); | |
265 | if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) | |
266 | posix_acl_release(inode->i_default_acl); | |
267 | #endif | |
cffbc8aa | 268 | percpu_counter_dec(&nr_inodes); |
2e00c97e CH |
269 | } |
270 | EXPORT_SYMBOL(__destroy_inode); | |
271 | ||
56b0dacf | 272 | static void destroy_inode(struct inode *inode) |
2e00c97e | 273 | { |
7ccf19a8 | 274 | BUG_ON(!list_empty(&inode->i_lru)); |
2e00c97e | 275 | __destroy_inode(inode); |
1da177e4 LT |
276 | if (inode->i_sb->s_op->destroy_inode) |
277 | inode->i_sb->s_op->destroy_inode(inode); | |
278 | else | |
279 | kmem_cache_free(inode_cachep, (inode)); | |
280 | } | |
1da177e4 LT |
281 | |
282 | /* | |
283 | * These are initializations that only need to be done | |
284 | * once, because the fields are idempotent across use | |
285 | * of the inode, so let the slab aware of that. | |
286 | */ | |
287 | void inode_init_once(struct inode *inode) | |
288 | { | |
289 | memset(inode, 0, sizeof(*inode)); | |
290 | INIT_HLIST_NODE(&inode->i_hash); | |
291 | INIT_LIST_HEAD(&inode->i_dentry); | |
292 | INIT_LIST_HEAD(&inode->i_devices); | |
7ccf19a8 NP |
293 | INIT_LIST_HEAD(&inode->i_wb_list); |
294 | INIT_LIST_HEAD(&inode->i_lru); | |
1da177e4 | 295 | INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); |
19fd6231 | 296 | spin_lock_init(&inode->i_data.tree_lock); |
1da177e4 LT |
297 | spin_lock_init(&inode->i_data.i_mmap_lock); |
298 | INIT_LIST_HEAD(&inode->i_data.private_list); | |
299 | spin_lock_init(&inode->i_data.private_lock); | |
300 | INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap); | |
301 | INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); | |
1da177e4 | 302 | i_size_ordered_init(inode); |
3be25f49 | 303 | #ifdef CONFIG_FSNOTIFY |
e61ce867 | 304 | INIT_HLIST_HEAD(&inode->i_fsnotify_marks); |
3be25f49 | 305 | #endif |
1da177e4 | 306 | } |
1da177e4 LT |
307 | EXPORT_SYMBOL(inode_init_once); |
308 | ||
51cc5068 | 309 | static void init_once(void *foo) |
1da177e4 | 310 | { |
6b3304b5 | 311 | struct inode *inode = (struct inode *) foo; |
1da177e4 | 312 | |
a35afb83 | 313 | inode_init_once(inode); |
1da177e4 LT |
314 | } |
315 | ||
316 | /* | |
317 | * inode_lock must be held | |
318 | */ | |
6b3304b5 | 319 | void __iget(struct inode *inode) |
1da177e4 | 320 | { |
9e38d86f NP |
321 | atomic_inc(&inode->i_count); |
322 | } | |
2e147f1e | 323 | |
7de9c6ee AV |
324 | /* |
325 | * get additional reference to inode; caller must already hold one. | |
326 | */ | |
327 | void ihold(struct inode *inode) | |
328 | { | |
329 | WARN_ON(atomic_inc_return(&inode->i_count) < 2); | |
330 | } | |
331 | EXPORT_SYMBOL(ihold); | |
332 | ||
9e38d86f NP |
333 | static void inode_lru_list_add(struct inode *inode) |
334 | { | |
7ccf19a8 NP |
335 | if (list_empty(&inode->i_lru)) { |
336 | list_add(&inode->i_lru, &inode_lru); | |
9e38d86f NP |
337 | percpu_counter_inc(&nr_inodes_unused); |
338 | } | |
339 | } | |
340 | ||
341 | static void inode_lru_list_del(struct inode *inode) | |
342 | { | |
7ccf19a8 NP |
343 | if (!list_empty(&inode->i_lru)) { |
344 | list_del_init(&inode->i_lru); | |
9e38d86f NP |
345 | percpu_counter_dec(&nr_inodes_unused); |
346 | } | |
1da177e4 LT |
347 | } |
348 | ||
646ec461 CH |
349 | static inline void __inode_sb_list_add(struct inode *inode) |
350 | { | |
351 | list_add(&inode->i_sb_list, &inode->i_sb->s_inodes); | |
352 | } | |
353 | ||
354 | /** | |
355 | * inode_sb_list_add - add inode to the superblock list of inodes | |
356 | * @inode: inode to add | |
357 | */ | |
358 | void inode_sb_list_add(struct inode *inode) | |
359 | { | |
360 | spin_lock(&inode_lock); | |
361 | __inode_sb_list_add(inode); | |
362 | spin_unlock(&inode_lock); | |
363 | } | |
364 | EXPORT_SYMBOL_GPL(inode_sb_list_add); | |
365 | ||
366 | static inline void __inode_sb_list_del(struct inode *inode) | |
367 | { | |
368 | list_del_init(&inode->i_sb_list); | |
369 | } | |
370 | ||
4c51acbc DC |
371 | static unsigned long hash(struct super_block *sb, unsigned long hashval) |
372 | { | |
373 | unsigned long tmp; | |
374 | ||
375 | tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / | |
376 | L1_CACHE_BYTES; | |
377 | tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS); | |
378 | return tmp & I_HASHMASK; | |
379 | } | |
380 | ||
381 | /** | |
382 | * __insert_inode_hash - hash an inode | |
383 | * @inode: unhashed inode | |
384 | * @hashval: unsigned long value used to locate this object in the | |
385 | * inode_hashtable. | |
386 | * | |
387 | * Add an inode to the inode hash for this superblock. | |
388 | */ | |
389 | void __insert_inode_hash(struct inode *inode, unsigned long hashval) | |
390 | { | |
646ec461 CH |
391 | struct hlist_head *b = inode_hashtable + hash(inode->i_sb, hashval); |
392 | ||
4c51acbc | 393 | spin_lock(&inode_lock); |
646ec461 | 394 | hlist_add_head(&inode->i_hash, b); |
4c51acbc DC |
395 | spin_unlock(&inode_lock); |
396 | } | |
397 | EXPORT_SYMBOL(__insert_inode_hash); | |
398 | ||
399 | /** | |
400 | * __remove_inode_hash - remove an inode from the hash | |
401 | * @inode: inode to unhash | |
402 | * | |
403 | * Remove an inode from the superblock. | |
404 | */ | |
405 | static void __remove_inode_hash(struct inode *inode) | |
406 | { | |
407 | hlist_del_init(&inode->i_hash); | |
408 | } | |
409 | ||
410 | /** | |
411 | * remove_inode_hash - remove an inode from the hash | |
412 | * @inode: inode to unhash | |
413 | * | |
414 | * Remove an inode from the superblock. | |
415 | */ | |
416 | void remove_inode_hash(struct inode *inode) | |
417 | { | |
418 | spin_lock(&inode_lock); | |
419 | hlist_del_init(&inode->i_hash); | |
420 | spin_unlock(&inode_lock); | |
421 | } | |
422 | EXPORT_SYMBOL(remove_inode_hash); | |
423 | ||
b0683aa6 AV |
424 | void end_writeback(struct inode *inode) |
425 | { | |
426 | might_sleep(); | |
427 | BUG_ON(inode->i_data.nrpages); | |
428 | BUG_ON(!list_empty(&inode->i_data.private_list)); | |
429 | BUG_ON(!(inode->i_state & I_FREEING)); | |
430 | BUG_ON(inode->i_state & I_CLEAR); | |
431 | inode_sync_wait(inode); | |
432 | inode->i_state = I_FREEING | I_CLEAR; | |
433 | } | |
434 | EXPORT_SYMBOL(end_writeback); | |
435 | ||
644da596 | 436 | static void evict(struct inode *inode) |
b4272d4c AV |
437 | { |
438 | const struct super_operations *op = inode->i_sb->s_op; | |
439 | ||
be7ce416 AV |
440 | if (op->evict_inode) { |
441 | op->evict_inode(inode); | |
b4272d4c AV |
442 | } else { |
443 | if (inode->i_data.nrpages) | |
444 | truncate_inode_pages(&inode->i_data, 0); | |
30140837 | 445 | end_writeback(inode); |
b4272d4c | 446 | } |
661074e9 AV |
447 | if (S_ISBLK(inode->i_mode) && inode->i_bdev) |
448 | bd_forget(inode); | |
449 | if (S_ISCHR(inode->i_mode) && inode->i_cdev) | |
450 | cd_forget(inode); | |
b4272d4c AV |
451 | } |
452 | ||
1da177e4 LT |
453 | /* |
454 | * dispose_list - dispose of the contents of a local list | |
455 | * @head: the head of the list to free | |
456 | * | |
457 | * Dispose-list gets a local list with local inodes in it, so it doesn't | |
458 | * need to worry about list corruption and SMP locks. | |
459 | */ | |
460 | static void dispose_list(struct list_head *head) | |
461 | { | |
1da177e4 LT |
462 | while (!list_empty(head)) { |
463 | struct inode *inode; | |
464 | ||
7ccf19a8 NP |
465 | inode = list_first_entry(head, struct inode, i_lru); |
466 | list_del_init(&inode->i_lru); | |
1da177e4 | 467 | |
644da596 | 468 | evict(inode); |
4120db47 AB |
469 | |
470 | spin_lock(&inode_lock); | |
4c51acbc | 471 | __remove_inode_hash(inode); |
646ec461 | 472 | __inode_sb_list_del(inode); |
4120db47 AB |
473 | spin_unlock(&inode_lock); |
474 | ||
475 | wake_up_inode(inode); | |
1da177e4 | 476 | destroy_inode(inode); |
1da177e4 | 477 | } |
1da177e4 LT |
478 | } |
479 | ||
63997e98 AV |
480 | /** |
481 | * evict_inodes - evict all evictable inodes for a superblock | |
482 | * @sb: superblock to operate on | |
483 | * | |
484 | * Make sure that no inodes with zero refcount are retained. This is | |
485 | * called by superblock shutdown after having MS_ACTIVE flag removed, | |
486 | * so any inode reaching zero refcount during or after that call will | |
487 | * be immediately evicted. | |
488 | */ | |
489 | void evict_inodes(struct super_block *sb) | |
490 | { | |
491 | struct inode *inode, *next; | |
492 | LIST_HEAD(dispose); | |
493 | ||
494 | down_write(&iprune_sem); | |
495 | ||
496 | spin_lock(&inode_lock); | |
497 | list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { | |
498 | if (atomic_read(&inode->i_count)) | |
499 | continue; | |
500 | ||
501 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { | |
502 | WARN_ON(1); | |
503 | continue; | |
504 | } | |
505 | ||
506 | inode->i_state |= I_FREEING; | |
507 | ||
508 | /* | |
509 | * Move the inode off the IO lists and LRU once I_FREEING is | |
510 | * set so that it won't get moved back on there if it is dirty. | |
511 | */ | |
512 | list_move(&inode->i_lru, &dispose); | |
513 | list_del_init(&inode->i_wb_list); | |
514 | if (!(inode->i_state & (I_DIRTY | I_SYNC))) | |
515 | percpu_counter_dec(&nr_inodes_unused); | |
516 | } | |
517 | spin_unlock(&inode_lock); | |
518 | ||
519 | dispose_list(&dispose); | |
520 | up_write(&iprune_sem); | |
521 | } | |
522 | ||
a0318786 CH |
523 | /** |
524 | * invalidate_inodes - attempt to free all inodes on a superblock | |
525 | * @sb: superblock to operate on | |
526 | * | |
527 | * Attempts to free all inodes for a given superblock. If there were any | |
528 | * busy inodes return a non-zero value, else zero. | |
1da177e4 | 529 | */ |
a0318786 | 530 | int invalidate_inodes(struct super_block *sb) |
1da177e4 | 531 | { |
cffbc8aa | 532 | int busy = 0; |
a0318786 CH |
533 | struct inode *inode, *next; |
534 | LIST_HEAD(dispose); | |
1da177e4 | 535 | |
a0318786 CH |
536 | down_write(&iprune_sem); |
537 | ||
538 | spin_lock(&inode_lock); | |
a0318786 | 539 | list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { |
63997e98 | 540 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) |
aabb8fdb | 541 | continue; |
99a38919 CH |
542 | if (atomic_read(&inode->i_count)) { |
543 | busy = 1; | |
1da177e4 LT |
544 | continue; |
545 | } | |
99a38919 | 546 | |
99a38919 | 547 | inode->i_state |= I_FREEING; |
7ccf19a8 NP |
548 | |
549 | /* | |
550 | * Move the inode off the IO lists and LRU once I_FREEING is | |
551 | * set so that it won't get moved back on there if it is dirty. | |
552 | */ | |
a0318786 | 553 | list_move(&inode->i_lru, &dispose); |
7ccf19a8 | 554 | list_del_init(&inode->i_wb_list); |
99a38919 CH |
555 | if (!(inode->i_state & (I_DIRTY | I_SYNC))) |
556 | percpu_counter_dec(&nr_inodes_unused); | |
1da177e4 | 557 | } |
1da177e4 LT |
558 | spin_unlock(&inode_lock); |
559 | ||
a0318786 | 560 | dispose_list(&dispose); |
88e0fbc4 | 561 | up_write(&iprune_sem); |
1da177e4 LT |
562 | |
563 | return busy; | |
564 | } | |
1da177e4 LT |
565 | |
566 | static int can_unuse(struct inode *inode) | |
567 | { | |
9e38d86f | 568 | if (inode->i_state & ~I_REFERENCED) |
1da177e4 LT |
569 | return 0; |
570 | if (inode_has_buffers(inode)) | |
571 | return 0; | |
572 | if (atomic_read(&inode->i_count)) | |
573 | return 0; | |
574 | if (inode->i_data.nrpages) | |
575 | return 0; | |
576 | return 1; | |
577 | } | |
578 | ||
579 | /* | |
9e38d86f NP |
580 | * Scan `goal' inodes on the unused list for freeable ones. They are moved to a |
581 | * temporary list and then are freed outside inode_lock by dispose_list(). | |
1da177e4 LT |
582 | * |
583 | * Any inodes which are pinned purely because of attached pagecache have their | |
9e38d86f NP |
584 | * pagecache removed. If the inode has metadata buffers attached to |
585 | * mapping->private_list then try to remove them. | |
1da177e4 | 586 | * |
9e38d86f NP |
587 | * If the inode has the I_REFERENCED flag set, then it means that it has been |
588 | * used recently - the flag is set in iput_final(). When we encounter such an | |
589 | * inode, clear the flag and move it to the back of the LRU so it gets another | |
590 | * pass through the LRU before it gets reclaimed. This is necessary because of | |
591 | * the fact we are doing lazy LRU updates to minimise lock contention so the | |
592 | * LRU does not have strict ordering. Hence we don't want to reclaim inodes | |
593 | * with this flag set because they are the inodes that are out of order. | |
1da177e4 LT |
594 | */ |
595 | static void prune_icache(int nr_to_scan) | |
596 | { | |
597 | LIST_HEAD(freeable); | |
1da177e4 LT |
598 | int nr_scanned; |
599 | unsigned long reap = 0; | |
600 | ||
88e0fbc4 | 601 | down_read(&iprune_sem); |
1da177e4 LT |
602 | spin_lock(&inode_lock); |
603 | for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { | |
604 | struct inode *inode; | |
605 | ||
7ccf19a8 | 606 | if (list_empty(&inode_lru)) |
1da177e4 LT |
607 | break; |
608 | ||
7ccf19a8 | 609 | inode = list_entry(inode_lru.prev, struct inode, i_lru); |
1da177e4 | 610 | |
9e38d86f NP |
611 | /* |
612 | * Referenced or dirty inodes are still in use. Give them | |
613 | * another pass through the LRU as we canot reclaim them now. | |
614 | */ | |
615 | if (atomic_read(&inode->i_count) || | |
616 | (inode->i_state & ~I_REFERENCED)) { | |
7ccf19a8 | 617 | list_del_init(&inode->i_lru); |
9e38d86f NP |
618 | percpu_counter_dec(&nr_inodes_unused); |
619 | continue; | |
620 | } | |
621 | ||
622 | /* recently referenced inodes get one more pass */ | |
623 | if (inode->i_state & I_REFERENCED) { | |
7ccf19a8 | 624 | list_move(&inode->i_lru, &inode_lru); |
9e38d86f | 625 | inode->i_state &= ~I_REFERENCED; |
1da177e4 LT |
626 | continue; |
627 | } | |
628 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { | |
629 | __iget(inode); | |
630 | spin_unlock(&inode_lock); | |
631 | if (remove_inode_buffers(inode)) | |
fc0ecff6 AM |
632 | reap += invalidate_mapping_pages(&inode->i_data, |
633 | 0, -1); | |
1da177e4 LT |
634 | iput(inode); |
635 | spin_lock(&inode_lock); | |
636 | ||
7ccf19a8 NP |
637 | if (inode != list_entry(inode_lru.next, |
638 | struct inode, i_lru)) | |
1da177e4 LT |
639 | continue; /* wrong inode or list_empty */ |
640 | if (!can_unuse(inode)) | |
641 | continue; | |
642 | } | |
7ef0d737 | 643 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 | 644 | inode->i_state |= I_FREEING; |
7ccf19a8 NP |
645 | |
646 | /* | |
647 | * Move the inode off the IO lists and LRU once I_FREEING is | |
648 | * set so that it won't get moved back on there if it is dirty. | |
649 | */ | |
650 | list_move(&inode->i_lru, &freeable); | |
651 | list_del_init(&inode->i_wb_list); | |
cffbc8aa | 652 | percpu_counter_dec(&nr_inodes_unused); |
1da177e4 | 653 | } |
f8891e5e CL |
654 | if (current_is_kswapd()) |
655 | __count_vm_events(KSWAPD_INODESTEAL, reap); | |
656 | else | |
657 | __count_vm_events(PGINODESTEAL, reap); | |
1da177e4 LT |
658 | spin_unlock(&inode_lock); |
659 | ||
660 | dispose_list(&freeable); | |
88e0fbc4 | 661 | up_read(&iprune_sem); |
1da177e4 LT |
662 | } |
663 | ||
664 | /* | |
665 | * shrink_icache_memory() will attempt to reclaim some unused inodes. Here, | |
666 | * "unused" means that no dentries are referring to the inodes: the files are | |
667 | * not open and the dcache references to those inodes have already been | |
668 | * reclaimed. | |
669 | * | |
670 | * This function is passed the number of inodes to scan, and it returns the | |
671 | * total number of remaining possibly-reclaimable inodes. | |
672 | */ | |
7f8275d0 | 673 | static int shrink_icache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask) |
1da177e4 LT |
674 | { |
675 | if (nr) { | |
676 | /* | |
677 | * Nasty deadlock avoidance. We may hold various FS locks, | |
678 | * and we don't want to recurse into the FS that called us | |
679 | * in clear_inode() and friends.. | |
6b3304b5 | 680 | */ |
1da177e4 LT |
681 | if (!(gfp_mask & __GFP_FS)) |
682 | return -1; | |
683 | prune_icache(nr); | |
684 | } | |
cffbc8aa | 685 | return (get_nr_inodes_unused() / 100) * sysctl_vfs_cache_pressure; |
1da177e4 LT |
686 | } |
687 | ||
8e1f936b RR |
688 | static struct shrinker icache_shrinker = { |
689 | .shrink = shrink_icache_memory, | |
690 | .seeks = DEFAULT_SEEKS, | |
691 | }; | |
692 | ||
1da177e4 LT |
693 | static void __wait_on_freeing_inode(struct inode *inode); |
694 | /* | |
695 | * Called with the inode lock held. | |
1da177e4 | 696 | */ |
6b3304b5 MK |
697 | static struct inode *find_inode(struct super_block *sb, |
698 | struct hlist_head *head, | |
699 | int (*test)(struct inode *, void *), | |
700 | void *data) | |
1da177e4 LT |
701 | { |
702 | struct hlist_node *node; | |
6b3304b5 | 703 | struct inode *inode = NULL; |
1da177e4 LT |
704 | |
705 | repeat: | |
c5c8be3c | 706 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
707 | if (inode->i_sb != sb) |
708 | continue; | |
709 | if (!test(inode, data)) | |
710 | continue; | |
a4ffdde6 | 711 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
1da177e4 LT |
712 | __wait_on_freeing_inode(inode); |
713 | goto repeat; | |
714 | } | |
f7899bd5 CH |
715 | __iget(inode); |
716 | return inode; | |
1da177e4 | 717 | } |
f7899bd5 | 718 | return NULL; |
1da177e4 LT |
719 | } |
720 | ||
721 | /* | |
722 | * find_inode_fast is the fast path version of find_inode, see the comment at | |
723 | * iget_locked for details. | |
724 | */ | |
6b3304b5 MK |
725 | static struct inode *find_inode_fast(struct super_block *sb, |
726 | struct hlist_head *head, unsigned long ino) | |
1da177e4 LT |
727 | { |
728 | struct hlist_node *node; | |
6b3304b5 | 729 | struct inode *inode = NULL; |
1da177e4 LT |
730 | |
731 | repeat: | |
c5c8be3c | 732 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
733 | if (inode->i_ino != ino) |
734 | continue; | |
735 | if (inode->i_sb != sb) | |
736 | continue; | |
a4ffdde6 | 737 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
1da177e4 LT |
738 | __wait_on_freeing_inode(inode); |
739 | goto repeat; | |
740 | } | |
f7899bd5 CH |
741 | __iget(inode); |
742 | return inode; | |
1da177e4 | 743 | } |
f7899bd5 | 744 | return NULL; |
1da177e4 LT |
745 | } |
746 | ||
f991bd2e ED |
747 | /* |
748 | * Each cpu owns a range of LAST_INO_BATCH numbers. | |
749 | * 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations, | |
750 | * to renew the exhausted range. | |
751 | * | |
752 | * This does not significantly increase overflow rate because every CPU can | |
753 | * consume at most LAST_INO_BATCH-1 unused inode numbers. So there is | |
754 | * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the | |
755 | * 2^32 range, and is a worst-case. Even a 50% wastage would only increase | |
756 | * overflow rate by 2x, which does not seem too significant. | |
757 | * | |
758 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
759 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
760 | * here to attempt to avoid that. | |
761 | */ | |
762 | #define LAST_INO_BATCH 1024 | |
763 | static DEFINE_PER_CPU(unsigned int, last_ino); | |
764 | ||
85fe4025 | 765 | unsigned int get_next_ino(void) |
f991bd2e ED |
766 | { |
767 | unsigned int *p = &get_cpu_var(last_ino); | |
768 | unsigned int res = *p; | |
769 | ||
770 | #ifdef CONFIG_SMP | |
771 | if (unlikely((res & (LAST_INO_BATCH-1)) == 0)) { | |
772 | static atomic_t shared_last_ino; | |
773 | int next = atomic_add_return(LAST_INO_BATCH, &shared_last_ino); | |
774 | ||
775 | res = next - LAST_INO_BATCH; | |
776 | } | |
777 | #endif | |
778 | ||
779 | *p = ++res; | |
780 | put_cpu_var(last_ino); | |
781 | return res; | |
782 | } | |
85fe4025 | 783 | EXPORT_SYMBOL(get_next_ino); |
f991bd2e | 784 | |
1da177e4 LT |
785 | /** |
786 | * new_inode - obtain an inode | |
787 | * @sb: superblock | |
788 | * | |
769848c0 | 789 | * Allocates a new inode for given superblock. The default gfp_mask |
3c1d4378 | 790 | * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE. |
769848c0 MG |
791 | * If HIGHMEM pages are unsuitable or it is known that pages allocated |
792 | * for the page cache are not reclaimable or migratable, | |
793 | * mapping_set_gfp_mask() must be called with suitable flags on the | |
794 | * newly created inode's mapping | |
795 | * | |
1da177e4 LT |
796 | */ |
797 | struct inode *new_inode(struct super_block *sb) | |
798 | { | |
6b3304b5 | 799 | struct inode *inode; |
1da177e4 LT |
800 | |
801 | spin_lock_prefetch(&inode_lock); | |
6b3304b5 | 802 | |
1da177e4 LT |
803 | inode = alloc_inode(sb); |
804 | if (inode) { | |
805 | spin_lock(&inode_lock); | |
646ec461 | 806 | __inode_sb_list_add(inode); |
1da177e4 LT |
807 | inode->i_state = 0; |
808 | spin_unlock(&inode_lock); | |
809 | } | |
810 | return inode; | |
811 | } | |
1da177e4 LT |
812 | EXPORT_SYMBOL(new_inode); |
813 | ||
814 | void unlock_new_inode(struct inode *inode) | |
815 | { | |
14358e6d | 816 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
a3314a0e | 817 | if (S_ISDIR(inode->i_mode)) { |
1e89a5e1 PZ |
818 | struct file_system_type *type = inode->i_sb->s_type; |
819 | ||
9a7aa12f JK |
820 | /* Set new key only if filesystem hasn't already changed it */ |
821 | if (!lockdep_match_class(&inode->i_mutex, | |
822 | &type->i_mutex_key)) { | |
823 | /* | |
824 | * ensure nobody is actually holding i_mutex | |
825 | */ | |
826 | mutex_destroy(&inode->i_mutex); | |
827 | mutex_init(&inode->i_mutex); | |
828 | lockdep_set_class(&inode->i_mutex, | |
829 | &type->i_mutex_dir_key); | |
830 | } | |
1e89a5e1 | 831 | } |
14358e6d | 832 | #endif |
1da177e4 | 833 | /* |
eaff8079 | 834 | * This is special! We do not need the spinlock when clearing I_NEW, |
580be083 JK |
835 | * because we're guaranteed that nobody else tries to do anything about |
836 | * the state of the inode when it is locked, as we just created it (so | |
eaff8079 | 837 | * there can be no old holders that haven't tested I_NEW). |
580be083 | 838 | * However we must emit the memory barrier so that other CPUs reliably |
eaff8079 | 839 | * see the clearing of I_NEW after the other inode initialisation has |
580be083 | 840 | * completed. |
1da177e4 | 841 | */ |
580be083 | 842 | smp_mb(); |
eaff8079 CH |
843 | WARN_ON(!(inode->i_state & I_NEW)); |
844 | inode->i_state &= ~I_NEW; | |
1da177e4 LT |
845 | wake_up_inode(inode); |
846 | } | |
1da177e4 LT |
847 | EXPORT_SYMBOL(unlock_new_inode); |
848 | ||
849 | /* | |
850 | * This is called without the inode lock held.. Be careful. | |
851 | * | |
852 | * We no longer cache the sb_flags in i_flags - see fs.h | |
853 | * -- rmk@arm.uk.linux.org | |
854 | */ | |
6b3304b5 MK |
855 | static struct inode *get_new_inode(struct super_block *sb, |
856 | struct hlist_head *head, | |
857 | int (*test)(struct inode *, void *), | |
858 | int (*set)(struct inode *, void *), | |
859 | void *data) | |
1da177e4 | 860 | { |
6b3304b5 | 861 | struct inode *inode; |
1da177e4 LT |
862 | |
863 | inode = alloc_inode(sb); | |
864 | if (inode) { | |
6b3304b5 | 865 | struct inode *old; |
1da177e4 LT |
866 | |
867 | spin_lock(&inode_lock); | |
868 | /* We released the lock, so.. */ | |
869 | old = find_inode(sb, head, test, data); | |
870 | if (!old) { | |
871 | if (set(inode, data)) | |
872 | goto set_failed; | |
873 | ||
646ec461 CH |
874 | hlist_add_head(&inode->i_hash, head); |
875 | __inode_sb_list_add(inode); | |
eaff8079 | 876 | inode->i_state = I_NEW; |
1da177e4 LT |
877 | spin_unlock(&inode_lock); |
878 | ||
879 | /* Return the locked inode with I_NEW set, the | |
880 | * caller is responsible for filling in the contents | |
881 | */ | |
882 | return inode; | |
883 | } | |
884 | ||
885 | /* | |
886 | * Uhhuh, somebody else created the same inode under | |
887 | * us. Use the old inode instead of the one we just | |
888 | * allocated. | |
889 | */ | |
1da177e4 LT |
890 | spin_unlock(&inode_lock); |
891 | destroy_inode(inode); | |
892 | inode = old; | |
893 | wait_on_inode(inode); | |
894 | } | |
895 | return inode; | |
896 | ||
897 | set_failed: | |
898 | spin_unlock(&inode_lock); | |
899 | destroy_inode(inode); | |
900 | return NULL; | |
901 | } | |
902 | ||
903 | /* | |
904 | * get_new_inode_fast is the fast path version of get_new_inode, see the | |
905 | * comment at iget_locked for details. | |
906 | */ | |
6b3304b5 MK |
907 | static struct inode *get_new_inode_fast(struct super_block *sb, |
908 | struct hlist_head *head, unsigned long ino) | |
1da177e4 | 909 | { |
6b3304b5 | 910 | struct inode *inode; |
1da177e4 LT |
911 | |
912 | inode = alloc_inode(sb); | |
913 | if (inode) { | |
6b3304b5 | 914 | struct inode *old; |
1da177e4 LT |
915 | |
916 | spin_lock(&inode_lock); | |
917 | /* We released the lock, so.. */ | |
918 | old = find_inode_fast(sb, head, ino); | |
919 | if (!old) { | |
920 | inode->i_ino = ino; | |
646ec461 CH |
921 | hlist_add_head(&inode->i_hash, head); |
922 | __inode_sb_list_add(inode); | |
eaff8079 | 923 | inode->i_state = I_NEW; |
1da177e4 LT |
924 | spin_unlock(&inode_lock); |
925 | ||
926 | /* Return the locked inode with I_NEW set, the | |
927 | * caller is responsible for filling in the contents | |
928 | */ | |
929 | return inode; | |
930 | } | |
931 | ||
932 | /* | |
933 | * Uhhuh, somebody else created the same inode under | |
934 | * us. Use the old inode instead of the one we just | |
935 | * allocated. | |
936 | */ | |
1da177e4 LT |
937 | spin_unlock(&inode_lock); |
938 | destroy_inode(inode); | |
939 | inode = old; | |
940 | wait_on_inode(inode); | |
941 | } | |
942 | return inode; | |
943 | } | |
944 | ||
ad5e195a CH |
945 | /* |
946 | * search the inode cache for a matching inode number. | |
947 | * If we find one, then the inode number we are trying to | |
948 | * allocate is not unique and so we should not use it. | |
949 | * | |
950 | * Returns 1 if the inode number is unique, 0 if it is not. | |
951 | */ | |
952 | static int test_inode_iunique(struct super_block *sb, unsigned long ino) | |
953 | { | |
954 | struct hlist_head *b = inode_hashtable + hash(sb, ino); | |
955 | struct hlist_node *node; | |
956 | struct inode *inode; | |
957 | ||
958 | hlist_for_each_entry(inode, node, b, i_hash) { | |
959 | if (inode->i_ino == ino && inode->i_sb == sb) | |
960 | return 0; | |
961 | } | |
962 | ||
963 | return 1; | |
964 | } | |
965 | ||
1da177e4 LT |
966 | /** |
967 | * iunique - get a unique inode number | |
968 | * @sb: superblock | |
969 | * @max_reserved: highest reserved inode number | |
970 | * | |
971 | * Obtain an inode number that is unique on the system for a given | |
972 | * superblock. This is used by file systems that have no natural | |
973 | * permanent inode numbering system. An inode number is returned that | |
974 | * is higher than the reserved limit but unique. | |
975 | * | |
976 | * BUGS: | |
977 | * With a large number of inodes live on the file system this function | |
978 | * currently becomes quite slow. | |
979 | */ | |
980 | ino_t iunique(struct super_block *sb, ino_t max_reserved) | |
981 | { | |
866b04fc JL |
982 | /* |
983 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
984 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
985 | * here to attempt to avoid that. | |
986 | */ | |
ad5e195a | 987 | static DEFINE_SPINLOCK(iunique_lock); |
866b04fc | 988 | static unsigned int counter; |
1da177e4 | 989 | ino_t res; |
3361c7be | 990 | |
1da177e4 | 991 | spin_lock(&inode_lock); |
ad5e195a | 992 | spin_lock(&iunique_lock); |
3361c7be JL |
993 | do { |
994 | if (counter <= max_reserved) | |
995 | counter = max_reserved + 1; | |
1da177e4 | 996 | res = counter++; |
ad5e195a CH |
997 | } while (!test_inode_iunique(sb, res)); |
998 | spin_unlock(&iunique_lock); | |
3361c7be | 999 | spin_unlock(&inode_lock); |
1da177e4 | 1000 | |
3361c7be JL |
1001 | return res; |
1002 | } | |
1da177e4 LT |
1003 | EXPORT_SYMBOL(iunique); |
1004 | ||
1005 | struct inode *igrab(struct inode *inode) | |
1006 | { | |
1007 | spin_lock(&inode_lock); | |
a4ffdde6 | 1008 | if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) |
1da177e4 LT |
1009 | __iget(inode); |
1010 | else | |
1011 | /* | |
1012 | * Handle the case where s_op->clear_inode is not been | |
1013 | * called yet, and somebody is calling igrab | |
1014 | * while the inode is getting freed. | |
1015 | */ | |
1016 | inode = NULL; | |
1017 | spin_unlock(&inode_lock); | |
1018 | return inode; | |
1019 | } | |
1da177e4 LT |
1020 | EXPORT_SYMBOL(igrab); |
1021 | ||
1022 | /** | |
1023 | * ifind - internal function, you want ilookup5() or iget5(). | |
1024 | * @sb: super block of file system to search | |
1025 | * @head: the head of the list to search | |
1026 | * @test: callback used for comparisons between inodes | |
1027 | * @data: opaque data pointer to pass to @test | |
88bd5121 | 1028 | * @wait: if true wait for the inode to be unlocked, if false do not |
1da177e4 LT |
1029 | * |
1030 | * ifind() searches for the inode specified by @data in the inode | |
1031 | * cache. This is a generalized version of ifind_fast() for file systems where | |
1032 | * the inode number is not sufficient for unique identification of an inode. | |
1033 | * | |
1034 | * If the inode is in the cache, the inode is returned with an incremented | |
1035 | * reference count. | |
1036 | * | |
1037 | * Otherwise NULL is returned. | |
1038 | * | |
1039 | * Note, @test is called with the inode_lock held, so can't sleep. | |
1040 | */ | |
5d2bea45 | 1041 | static struct inode *ifind(struct super_block *sb, |
1da177e4 | 1042 | struct hlist_head *head, int (*test)(struct inode *, void *), |
88bd5121 | 1043 | void *data, const int wait) |
1da177e4 LT |
1044 | { |
1045 | struct inode *inode; | |
1046 | ||
1047 | spin_lock(&inode_lock); | |
1048 | inode = find_inode(sb, head, test, data); | |
1049 | if (inode) { | |
1da177e4 | 1050 | spin_unlock(&inode_lock); |
88bd5121 AA |
1051 | if (likely(wait)) |
1052 | wait_on_inode(inode); | |
1da177e4 LT |
1053 | return inode; |
1054 | } | |
1055 | spin_unlock(&inode_lock); | |
1056 | return NULL; | |
1057 | } | |
1058 | ||
1059 | /** | |
1060 | * ifind_fast - internal function, you want ilookup() or iget(). | |
1061 | * @sb: super block of file system to search | |
1062 | * @head: head of the list to search | |
1063 | * @ino: inode number to search for | |
1064 | * | |
1065 | * ifind_fast() searches for the inode @ino in the inode cache. This is for | |
1066 | * file systems where the inode number is sufficient for unique identification | |
1067 | * of an inode. | |
1068 | * | |
1069 | * If the inode is in the cache, the inode is returned with an incremented | |
1070 | * reference count. | |
1071 | * | |
1072 | * Otherwise NULL is returned. | |
1073 | */ | |
5d2bea45 | 1074 | static struct inode *ifind_fast(struct super_block *sb, |
1da177e4 LT |
1075 | struct hlist_head *head, unsigned long ino) |
1076 | { | |
1077 | struct inode *inode; | |
1078 | ||
1079 | spin_lock(&inode_lock); | |
1080 | inode = find_inode_fast(sb, head, ino); | |
1081 | if (inode) { | |
1da177e4 LT |
1082 | spin_unlock(&inode_lock); |
1083 | wait_on_inode(inode); | |
1084 | return inode; | |
1085 | } | |
1086 | spin_unlock(&inode_lock); | |
1087 | return NULL; | |
1088 | } | |
1089 | ||
1090 | /** | |
88bd5121 | 1091 | * ilookup5_nowait - search for an inode in the inode cache |
1da177e4 LT |
1092 | * @sb: super block of file system to search |
1093 | * @hashval: hash value (usually inode number) to search for | |
1094 | * @test: callback used for comparisons between inodes | |
1095 | * @data: opaque data pointer to pass to @test | |
1096 | * | |
1097 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
1098 | * @data in the inode cache. This is a generalized version of ilookup() for | |
1099 | * file systems where the inode number is not sufficient for unique | |
1100 | * identification of an inode. | |
1101 | * | |
1102 | * If the inode is in the cache, the inode is returned with an incremented | |
88bd5121 AA |
1103 | * reference count. Note, the inode lock is not waited upon so you have to be |
1104 | * very careful what you do with the returned inode. You probably should be | |
1105 | * using ilookup5() instead. | |
1106 | * | |
1107 | * Otherwise NULL is returned. | |
1108 | * | |
1109 | * Note, @test is called with the inode_lock held, so can't sleep. | |
1110 | */ | |
1111 | struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, | |
1112 | int (*test)(struct inode *, void *), void *data) | |
1113 | { | |
1114 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
1115 | ||
1116 | return ifind(sb, head, test, data, 0); | |
1117 | } | |
88bd5121 AA |
1118 | EXPORT_SYMBOL(ilookup5_nowait); |
1119 | ||
1120 | /** | |
1121 | * ilookup5 - search for an inode in the inode cache | |
1122 | * @sb: super block of file system to search | |
1123 | * @hashval: hash value (usually inode number) to search for | |
1124 | * @test: callback used for comparisons between inodes | |
1125 | * @data: opaque data pointer to pass to @test | |
1126 | * | |
1127 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
1128 | * @data in the inode cache. This is a generalized version of ilookup() for | |
1129 | * file systems where the inode number is not sufficient for unique | |
1130 | * identification of an inode. | |
1131 | * | |
1132 | * If the inode is in the cache, the inode lock is waited upon and the inode is | |
1133 | * returned with an incremented reference count. | |
1da177e4 LT |
1134 | * |
1135 | * Otherwise NULL is returned. | |
1136 | * | |
1137 | * Note, @test is called with the inode_lock held, so can't sleep. | |
1138 | */ | |
1139 | struct inode *ilookup5(struct super_block *sb, unsigned long hashval, | |
1140 | int (*test)(struct inode *, void *), void *data) | |
1141 | { | |
1142 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
1143 | ||
88bd5121 | 1144 | return ifind(sb, head, test, data, 1); |
1da177e4 | 1145 | } |
1da177e4 LT |
1146 | EXPORT_SYMBOL(ilookup5); |
1147 | ||
1148 | /** | |
1149 | * ilookup - search for an inode in the inode cache | |
1150 | * @sb: super block of file system to search | |
1151 | * @ino: inode number to search for | |
1152 | * | |
1153 | * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache. | |
1154 | * This is for file systems where the inode number is sufficient for unique | |
1155 | * identification of an inode. | |
1156 | * | |
1157 | * If the inode is in the cache, the inode is returned with an incremented | |
1158 | * reference count. | |
1159 | * | |
1160 | * Otherwise NULL is returned. | |
1161 | */ | |
1162 | struct inode *ilookup(struct super_block *sb, unsigned long ino) | |
1163 | { | |
1164 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
1165 | ||
1166 | return ifind_fast(sb, head, ino); | |
1167 | } | |
1da177e4 LT |
1168 | EXPORT_SYMBOL(ilookup); |
1169 | ||
1170 | /** | |
1171 | * iget5_locked - obtain an inode from a mounted file system | |
1172 | * @sb: super block of file system | |
1173 | * @hashval: hash value (usually inode number) to get | |
1174 | * @test: callback used for comparisons between inodes | |
1175 | * @set: callback used to initialize a new struct inode | |
1176 | * @data: opaque data pointer to pass to @test and @set | |
1177 | * | |
1da177e4 LT |
1178 | * iget5_locked() uses ifind() to search for the inode specified by @hashval |
1179 | * and @data in the inode cache and if present it is returned with an increased | |
1180 | * reference count. This is a generalized version of iget_locked() for file | |
1181 | * systems where the inode number is not sufficient for unique identification | |
1182 | * of an inode. | |
1183 | * | |
1184 | * If the inode is not in cache, get_new_inode() is called to allocate a new | |
1185 | * inode and this is returned locked, hashed, and with the I_NEW flag set. The | |
1186 | * file system gets to fill it in before unlocking it via unlock_new_inode(). | |
1187 | * | |
1188 | * Note both @test and @set are called with the inode_lock held, so can't sleep. | |
1189 | */ | |
1190 | struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, | |
1191 | int (*test)(struct inode *, void *), | |
1192 | int (*set)(struct inode *, void *), void *data) | |
1193 | { | |
1194 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
1195 | struct inode *inode; | |
1196 | ||
88bd5121 | 1197 | inode = ifind(sb, head, test, data, 1); |
1da177e4 LT |
1198 | if (inode) |
1199 | return inode; | |
1200 | /* | |
1201 | * get_new_inode() will do the right thing, re-trying the search | |
1202 | * in case it had to block at any point. | |
1203 | */ | |
1204 | return get_new_inode(sb, head, test, set, data); | |
1205 | } | |
1da177e4 LT |
1206 | EXPORT_SYMBOL(iget5_locked); |
1207 | ||
1208 | /** | |
1209 | * iget_locked - obtain an inode from a mounted file system | |
1210 | * @sb: super block of file system | |
1211 | * @ino: inode number to get | |
1212 | * | |
1da177e4 LT |
1213 | * iget_locked() uses ifind_fast() to search for the inode specified by @ino in |
1214 | * the inode cache and if present it is returned with an increased reference | |
1215 | * count. This is for file systems where the inode number is sufficient for | |
1216 | * unique identification of an inode. | |
1217 | * | |
1218 | * If the inode is not in cache, get_new_inode_fast() is called to allocate a | |
1219 | * new inode and this is returned locked, hashed, and with the I_NEW flag set. | |
1220 | * The file system gets to fill it in before unlocking it via | |
1221 | * unlock_new_inode(). | |
1222 | */ | |
1223 | struct inode *iget_locked(struct super_block *sb, unsigned long ino) | |
1224 | { | |
1225 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
1226 | struct inode *inode; | |
1227 | ||
1228 | inode = ifind_fast(sb, head, ino); | |
1229 | if (inode) | |
1230 | return inode; | |
1231 | /* | |
1232 | * get_new_inode_fast() will do the right thing, re-trying the search | |
1233 | * in case it had to block at any point. | |
1234 | */ | |
1235 | return get_new_inode_fast(sb, head, ino); | |
1236 | } | |
1da177e4 LT |
1237 | EXPORT_SYMBOL(iget_locked); |
1238 | ||
261bca86 AV |
1239 | int insert_inode_locked(struct inode *inode) |
1240 | { | |
1241 | struct super_block *sb = inode->i_sb; | |
1242 | ino_t ino = inode->i_ino; | |
1243 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
261bca86 | 1244 | |
eaff8079 | 1245 | inode->i_state |= I_NEW; |
261bca86 | 1246 | while (1) { |
72a43d63 AV |
1247 | struct hlist_node *node; |
1248 | struct inode *old = NULL; | |
261bca86 | 1249 | spin_lock(&inode_lock); |
72a43d63 AV |
1250 | hlist_for_each_entry(old, node, head, i_hash) { |
1251 | if (old->i_ino != ino) | |
1252 | continue; | |
1253 | if (old->i_sb != sb) | |
1254 | continue; | |
a4ffdde6 | 1255 | if (old->i_state & (I_FREEING|I_WILL_FREE)) |
72a43d63 AV |
1256 | continue; |
1257 | break; | |
1258 | } | |
1259 | if (likely(!node)) { | |
261bca86 AV |
1260 | hlist_add_head(&inode->i_hash, head); |
1261 | spin_unlock(&inode_lock); | |
1262 | return 0; | |
1263 | } | |
1264 | __iget(old); | |
1265 | spin_unlock(&inode_lock); | |
1266 | wait_on_inode(old); | |
1d3382cb | 1267 | if (unlikely(!inode_unhashed(old))) { |
261bca86 AV |
1268 | iput(old); |
1269 | return -EBUSY; | |
1270 | } | |
1271 | iput(old); | |
1272 | } | |
1273 | } | |
261bca86 AV |
1274 | EXPORT_SYMBOL(insert_inode_locked); |
1275 | ||
1276 | int insert_inode_locked4(struct inode *inode, unsigned long hashval, | |
1277 | int (*test)(struct inode *, void *), void *data) | |
1278 | { | |
1279 | struct super_block *sb = inode->i_sb; | |
1280 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
261bca86 | 1281 | |
eaff8079 | 1282 | inode->i_state |= I_NEW; |
261bca86 AV |
1283 | |
1284 | while (1) { | |
72a43d63 AV |
1285 | struct hlist_node *node; |
1286 | struct inode *old = NULL; | |
1287 | ||
261bca86 | 1288 | spin_lock(&inode_lock); |
72a43d63 AV |
1289 | hlist_for_each_entry(old, node, head, i_hash) { |
1290 | if (old->i_sb != sb) | |
1291 | continue; | |
1292 | if (!test(old, data)) | |
1293 | continue; | |
a4ffdde6 | 1294 | if (old->i_state & (I_FREEING|I_WILL_FREE)) |
72a43d63 AV |
1295 | continue; |
1296 | break; | |
1297 | } | |
1298 | if (likely(!node)) { | |
261bca86 AV |
1299 | hlist_add_head(&inode->i_hash, head); |
1300 | spin_unlock(&inode_lock); | |
1301 | return 0; | |
1302 | } | |
1303 | __iget(old); | |
1304 | spin_unlock(&inode_lock); | |
1305 | wait_on_inode(old); | |
1d3382cb | 1306 | if (unlikely(!inode_unhashed(old))) { |
261bca86 AV |
1307 | iput(old); |
1308 | return -EBUSY; | |
1309 | } | |
1310 | iput(old); | |
1311 | } | |
1312 | } | |
261bca86 AV |
1313 | EXPORT_SYMBOL(insert_inode_locked4); |
1314 | ||
1da177e4 | 1315 | |
45321ac5 AV |
1316 | int generic_delete_inode(struct inode *inode) |
1317 | { | |
1318 | return 1; | |
1319 | } | |
1320 | EXPORT_SYMBOL(generic_delete_inode); | |
1321 | ||
1da177e4 | 1322 | /* |
45321ac5 AV |
1323 | * Normal UNIX filesystem behaviour: delete the |
1324 | * inode when the usage count drops to zero, and | |
1325 | * i_nlink is zero. | |
1da177e4 | 1326 | */ |
45321ac5 | 1327 | int generic_drop_inode(struct inode *inode) |
1da177e4 | 1328 | { |
1d3382cb | 1329 | return !inode->i_nlink || inode_unhashed(inode); |
1da177e4 | 1330 | } |
45321ac5 | 1331 | EXPORT_SYMBOL_GPL(generic_drop_inode); |
1da177e4 | 1332 | |
45321ac5 AV |
1333 | /* |
1334 | * Called when we're dropping the last reference | |
1335 | * to an inode. | |
22fe4042 | 1336 | * |
45321ac5 AV |
1337 | * Call the FS "drop_inode()" function, defaulting to |
1338 | * the legacy UNIX filesystem behaviour. If it tells | |
1339 | * us to evict inode, do so. Otherwise, retain inode | |
1340 | * in cache if fs is alive, sync and evict if fs is | |
1341 | * shutting down. | |
22fe4042 | 1342 | */ |
45321ac5 | 1343 | static void iput_final(struct inode *inode) |
1da177e4 LT |
1344 | { |
1345 | struct super_block *sb = inode->i_sb; | |
45321ac5 AV |
1346 | const struct super_operations *op = inode->i_sb->s_op; |
1347 | int drop; | |
1348 | ||
1349 | if (op && op->drop_inode) | |
1350 | drop = op->drop_inode(inode); | |
1351 | else | |
1352 | drop = generic_drop_inode(inode); | |
1da177e4 | 1353 | |
45321ac5 | 1354 | if (!drop) { |
acb0c854 | 1355 | if (sb->s_flags & MS_ACTIVE) { |
9e38d86f NP |
1356 | inode->i_state |= I_REFERENCED; |
1357 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) { | |
1358 | inode_lru_list_add(inode); | |
1359 | } | |
991114c6 | 1360 | spin_unlock(&inode_lock); |
45321ac5 | 1361 | return; |
991114c6 | 1362 | } |
7ef0d737 | 1363 | WARN_ON(inode->i_state & I_NEW); |
991114c6 AV |
1364 | inode->i_state |= I_WILL_FREE; |
1365 | spin_unlock(&inode_lock); | |
1da177e4 LT |
1366 | write_inode_now(inode, 1); |
1367 | spin_lock(&inode_lock); | |
7ef0d737 | 1368 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1369 | inode->i_state &= ~I_WILL_FREE; |
4c51acbc | 1370 | __remove_inode_hash(inode); |
1da177e4 | 1371 | } |
7ccf19a8 | 1372 | |
7ef0d737 | 1373 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1374 | inode->i_state |= I_FREEING; |
9e38d86f NP |
1375 | |
1376 | /* | |
7ccf19a8 NP |
1377 | * Move the inode off the IO lists and LRU once I_FREEING is |
1378 | * set so that it won't get moved back on there if it is dirty. | |
9e38d86f NP |
1379 | */ |
1380 | inode_lru_list_del(inode); | |
7ccf19a8 | 1381 | list_del_init(&inode->i_wb_list); |
9e38d86f | 1382 | |
646ec461 | 1383 | __inode_sb_list_del(inode); |
1da177e4 | 1384 | spin_unlock(&inode_lock); |
644da596 | 1385 | evict(inode); |
4c51acbc | 1386 | remove_inode_hash(inode); |
7f04c26d | 1387 | wake_up_inode(inode); |
45321ac5 | 1388 | BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); |
1da177e4 LT |
1389 | destroy_inode(inode); |
1390 | } | |
1391 | ||
1da177e4 | 1392 | /** |
6b3304b5 | 1393 | * iput - put an inode |
1da177e4 LT |
1394 | * @inode: inode to put |
1395 | * | |
1396 | * Puts an inode, dropping its usage count. If the inode use count hits | |
1397 | * zero, the inode is then freed and may also be destroyed. | |
1398 | * | |
1399 | * Consequently, iput() can sleep. | |
1400 | */ | |
1401 | void iput(struct inode *inode) | |
1402 | { | |
1403 | if (inode) { | |
a4ffdde6 | 1404 | BUG_ON(inode->i_state & I_CLEAR); |
1da177e4 | 1405 | |
1da177e4 LT |
1406 | if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) |
1407 | iput_final(inode); | |
1408 | } | |
1409 | } | |
1da177e4 LT |
1410 | EXPORT_SYMBOL(iput); |
1411 | ||
1412 | /** | |
1413 | * bmap - find a block number in a file | |
1414 | * @inode: inode of file | |
1415 | * @block: block to find | |
1416 | * | |
1417 | * Returns the block number on the device holding the inode that | |
1418 | * is the disk block number for the block of the file requested. | |
1419 | * That is, asked for block 4 of inode 1 the function will return the | |
6b3304b5 | 1420 | * disk block relative to the disk start that holds that block of the |
1da177e4 LT |
1421 | * file. |
1422 | */ | |
6b3304b5 | 1423 | sector_t bmap(struct inode *inode, sector_t block) |
1da177e4 LT |
1424 | { |
1425 | sector_t res = 0; | |
1426 | if (inode->i_mapping->a_ops->bmap) | |
1427 | res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); | |
1428 | return res; | |
1429 | } | |
1da177e4 LT |
1430 | EXPORT_SYMBOL(bmap); |
1431 | ||
11ff6f05 MG |
1432 | /* |
1433 | * With relative atime, only update atime if the previous atime is | |
1434 | * earlier than either the ctime or mtime or if at least a day has | |
1435 | * passed since the last atime update. | |
1436 | */ | |
1437 | static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, | |
1438 | struct timespec now) | |
1439 | { | |
1440 | ||
1441 | if (!(mnt->mnt_flags & MNT_RELATIME)) | |
1442 | return 1; | |
1443 | /* | |
1444 | * Is mtime younger than atime? If yes, update atime: | |
1445 | */ | |
1446 | if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0) | |
1447 | return 1; | |
1448 | /* | |
1449 | * Is ctime younger than atime? If yes, update atime: | |
1450 | */ | |
1451 | if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0) | |
1452 | return 1; | |
1453 | ||
1454 | /* | |
1455 | * Is the previous atime value older than a day? If yes, | |
1456 | * update atime: | |
1457 | */ | |
1458 | if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60) | |
1459 | return 1; | |
1460 | /* | |
1461 | * Good, we can skip the atime update: | |
1462 | */ | |
1463 | return 0; | |
1464 | } | |
1465 | ||
1da177e4 | 1466 | /** |
869243a0 CH |
1467 | * touch_atime - update the access time |
1468 | * @mnt: mount the inode is accessed on | |
7045f37b | 1469 | * @dentry: dentry accessed |
1da177e4 LT |
1470 | * |
1471 | * Update the accessed time on an inode and mark it for writeback. | |
1472 | * This function automatically handles read only file systems and media, | |
1473 | * as well as the "noatime" flag and inode specific "noatime" markers. | |
1474 | */ | |
869243a0 | 1475 | void touch_atime(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4 | 1476 | { |
869243a0 | 1477 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
1478 | struct timespec now; |
1479 | ||
cdb70f3f | 1480 | if (inode->i_flags & S_NOATIME) |
b12536c2 | 1481 | return; |
37756ced | 1482 | if (IS_NOATIME(inode)) |
b12536c2 | 1483 | return; |
b2276138 | 1484 | if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1485 | return; |
47ae32d6 | 1486 | |
cdb70f3f | 1487 | if (mnt->mnt_flags & MNT_NOATIME) |
b12536c2 | 1488 | return; |
cdb70f3f | 1489 | if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1490 | return; |
1da177e4 LT |
1491 | |
1492 | now = current_fs_time(inode->i_sb); | |
11ff6f05 MG |
1493 | |
1494 | if (!relatime_need_update(mnt, inode, now)) | |
b12536c2 | 1495 | return; |
11ff6f05 | 1496 | |
47ae32d6 | 1497 | if (timespec_equal(&inode->i_atime, &now)) |
b12536c2 AK |
1498 | return; |
1499 | ||
1500 | if (mnt_want_write(mnt)) | |
1501 | return; | |
47ae32d6 VH |
1502 | |
1503 | inode->i_atime = now; | |
1504 | mark_inode_dirty_sync(inode); | |
cdb70f3f | 1505 | mnt_drop_write(mnt); |
1da177e4 | 1506 | } |
869243a0 | 1507 | EXPORT_SYMBOL(touch_atime); |
1da177e4 LT |
1508 | |
1509 | /** | |
870f4817 CH |
1510 | * file_update_time - update mtime and ctime time |
1511 | * @file: file accessed | |
1da177e4 | 1512 | * |
870f4817 CH |
1513 | * Update the mtime and ctime members of an inode and mark the inode |
1514 | * for writeback. Note that this function is meant exclusively for | |
1515 | * usage in the file write path of filesystems, and filesystems may | |
1516 | * choose to explicitly ignore update via this function with the | |
2eadfc0e | 1517 | * S_NOCMTIME inode flag, e.g. for network filesystem where these |
870f4817 | 1518 | * timestamps are handled by the server. |
1da177e4 LT |
1519 | */ |
1520 | ||
870f4817 | 1521 | void file_update_time(struct file *file) |
1da177e4 | 1522 | { |
0f7fc9e4 | 1523 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 | 1524 | struct timespec now; |
ce06e0b2 | 1525 | enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0; |
1da177e4 | 1526 | |
ce06e0b2 | 1527 | /* First try to exhaust all avenues to not sync */ |
1da177e4 LT |
1528 | if (IS_NOCMTIME(inode)) |
1529 | return; | |
20ddee2c | 1530 | |
1da177e4 | 1531 | now = current_fs_time(inode->i_sb); |
ce06e0b2 AK |
1532 | if (!timespec_equal(&inode->i_mtime, &now)) |
1533 | sync_it = S_MTIME; | |
1da177e4 | 1534 | |
ce06e0b2 AK |
1535 | if (!timespec_equal(&inode->i_ctime, &now)) |
1536 | sync_it |= S_CTIME; | |
870f4817 | 1537 | |
ce06e0b2 AK |
1538 | if (IS_I_VERSION(inode)) |
1539 | sync_it |= S_VERSION; | |
7a224228 | 1540 | |
ce06e0b2 AK |
1541 | if (!sync_it) |
1542 | return; | |
1543 | ||
1544 | /* Finally allowed to write? Takes lock. */ | |
1545 | if (mnt_want_write_file(file)) | |
1546 | return; | |
1547 | ||
1548 | /* Only change inode inside the lock region */ | |
1549 | if (sync_it & S_VERSION) | |
1550 | inode_inc_iversion(inode); | |
1551 | if (sync_it & S_CTIME) | |
1552 | inode->i_ctime = now; | |
1553 | if (sync_it & S_MTIME) | |
1554 | inode->i_mtime = now; | |
1555 | mark_inode_dirty_sync(inode); | |
20ddee2c | 1556 | mnt_drop_write(file->f_path.mnt); |
1da177e4 | 1557 | } |
870f4817 | 1558 | EXPORT_SYMBOL(file_update_time); |
1da177e4 LT |
1559 | |
1560 | int inode_needs_sync(struct inode *inode) | |
1561 | { | |
1562 | if (IS_SYNC(inode)) | |
1563 | return 1; | |
1564 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) | |
1565 | return 1; | |
1566 | return 0; | |
1567 | } | |
1da177e4 LT |
1568 | EXPORT_SYMBOL(inode_needs_sync); |
1569 | ||
1da177e4 LT |
1570 | int inode_wait(void *word) |
1571 | { | |
1572 | schedule(); | |
1573 | return 0; | |
1574 | } | |
d44dab8d | 1575 | EXPORT_SYMBOL(inode_wait); |
1da177e4 LT |
1576 | |
1577 | /* | |
168a9fd6 MS |
1578 | * If we try to find an inode in the inode hash while it is being |
1579 | * deleted, we have to wait until the filesystem completes its | |
1580 | * deletion before reporting that it isn't found. This function waits | |
1581 | * until the deletion _might_ have completed. Callers are responsible | |
1582 | * to recheck inode state. | |
1583 | * | |
eaff8079 | 1584 | * It doesn't matter if I_NEW is not set initially, a call to |
168a9fd6 MS |
1585 | * wake_up_inode() after removing from the hash list will DTRT. |
1586 | * | |
1da177e4 LT |
1587 | * This is called with inode_lock held. |
1588 | */ | |
1589 | static void __wait_on_freeing_inode(struct inode *inode) | |
1590 | { | |
1591 | wait_queue_head_t *wq; | |
eaff8079 CH |
1592 | DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); |
1593 | wq = bit_waitqueue(&inode->i_state, __I_NEW); | |
1da177e4 LT |
1594 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); |
1595 | spin_unlock(&inode_lock); | |
1596 | schedule(); | |
1597 | finish_wait(wq, &wait.wait); | |
1598 | spin_lock(&inode_lock); | |
1599 | } | |
1600 | ||
1da177e4 LT |
1601 | static __initdata unsigned long ihash_entries; |
1602 | static int __init set_ihash_entries(char *str) | |
1603 | { | |
1604 | if (!str) | |
1605 | return 0; | |
1606 | ihash_entries = simple_strtoul(str, &str, 0); | |
1607 | return 1; | |
1608 | } | |
1609 | __setup("ihash_entries=", set_ihash_entries); | |
1610 | ||
1611 | /* | |
1612 | * Initialize the waitqueues and inode hash table. | |
1613 | */ | |
1614 | void __init inode_init_early(void) | |
1615 | { | |
1616 | int loop; | |
1617 | ||
1618 | /* If hashes are distributed across NUMA nodes, defer | |
1619 | * hash allocation until vmalloc space is available. | |
1620 | */ | |
1621 | if (hashdist) | |
1622 | return; | |
1623 | ||
1624 | inode_hashtable = | |
1625 | alloc_large_system_hash("Inode-cache", | |
1626 | sizeof(struct hlist_head), | |
1627 | ihash_entries, | |
1628 | 14, | |
1629 | HASH_EARLY, | |
1630 | &i_hash_shift, | |
1631 | &i_hash_mask, | |
1632 | 0); | |
1633 | ||
1634 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1635 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1636 | } | |
1637 | ||
74bf17cf | 1638 | void __init inode_init(void) |
1da177e4 LT |
1639 | { |
1640 | int loop; | |
1641 | ||
1642 | /* inode slab cache */ | |
b0196009 PJ |
1643 | inode_cachep = kmem_cache_create("inode_cache", |
1644 | sizeof(struct inode), | |
1645 | 0, | |
1646 | (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| | |
1647 | SLAB_MEM_SPREAD), | |
20c2df83 | 1648 | init_once); |
8e1f936b | 1649 | register_shrinker(&icache_shrinker); |
cffbc8aa DC |
1650 | percpu_counter_init(&nr_inodes, 0); |
1651 | percpu_counter_init(&nr_inodes_unused, 0); | |
1da177e4 LT |
1652 | |
1653 | /* Hash may have been set up in inode_init_early */ | |
1654 | if (!hashdist) | |
1655 | return; | |
1656 | ||
1657 | inode_hashtable = | |
1658 | alloc_large_system_hash("Inode-cache", | |
1659 | sizeof(struct hlist_head), | |
1660 | ihash_entries, | |
1661 | 14, | |
1662 | 0, | |
1663 | &i_hash_shift, | |
1664 | &i_hash_mask, | |
1665 | 0); | |
1666 | ||
1667 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1668 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1669 | } | |
1670 | ||
1671 | void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) | |
1672 | { | |
1673 | inode->i_mode = mode; | |
1674 | if (S_ISCHR(mode)) { | |
1675 | inode->i_fop = &def_chr_fops; | |
1676 | inode->i_rdev = rdev; | |
1677 | } else if (S_ISBLK(mode)) { | |
1678 | inode->i_fop = &def_blk_fops; | |
1679 | inode->i_rdev = rdev; | |
1680 | } else if (S_ISFIFO(mode)) | |
1681 | inode->i_fop = &def_fifo_fops; | |
1682 | else if (S_ISSOCK(mode)) | |
1683 | inode->i_fop = &bad_sock_fops; | |
1684 | else | |
af0d9ae8 MK |
1685 | printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for" |
1686 | " inode %s:%lu\n", mode, inode->i_sb->s_id, | |
1687 | inode->i_ino); | |
1da177e4 LT |
1688 | } |
1689 | EXPORT_SYMBOL(init_special_inode); | |
a1bd120d DM |
1690 | |
1691 | /** | |
1692 | * Init uid,gid,mode for new inode according to posix standards | |
1693 | * @inode: New inode | |
1694 | * @dir: Directory inode | |
1695 | * @mode: mode of the new inode | |
1696 | */ | |
1697 | void inode_init_owner(struct inode *inode, const struct inode *dir, | |
1698 | mode_t mode) | |
1699 | { | |
1700 | inode->i_uid = current_fsuid(); | |
1701 | if (dir && dir->i_mode & S_ISGID) { | |
1702 | inode->i_gid = dir->i_gid; | |
1703 | if (S_ISDIR(mode)) | |
1704 | mode |= S_ISGID; | |
1705 | } else | |
1706 | inode->i_gid = current_fsgid(); | |
1707 | inode->i_mode = mode; | |
1708 | } | |
1709 | EXPORT_SYMBOL(inode_init_owner); |