Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 | 2 | * (C) 1997 Linus Torvalds |
4b4563dc | 3 | * (C) 1999 Andrea Arcangeli <andrea@suse.de> (dynamic inode allocation) |
1da177e4 | 4 | */ |
1da177e4 LT |
5 | #include <linux/fs.h> |
6 | #include <linux/mm.h> | |
7 | #include <linux/dcache.h> | |
8 | #include <linux/init.h> | |
1da177e4 LT |
9 | #include <linux/slab.h> |
10 | #include <linux/writeback.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/backing-dev.h> | |
13 | #include <linux/wait.h> | |
88e0fbc4 | 14 | #include <linux/rwsem.h> |
1da177e4 LT |
15 | #include <linux/hash.h> |
16 | #include <linux/swap.h> | |
17 | #include <linux/security.h> | |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/cdev.h> | |
20 | #include <linux/bootmem.h> | |
3be25f49 | 21 | #include <linux/fsnotify.h> |
fc33a7bb | 22 | #include <linux/mount.h> |
efaee192 | 23 | #include <linux/async.h> |
f19d4a8f | 24 | #include <linux/posix_acl.h> |
9ce6e0be | 25 | #include <linux/prefetch.h> |
a178d202 | 26 | #include <linux/ima.h> |
e795b717 | 27 | #include <linux/cred.h> |
4b4563dc | 28 | #include <linux/buffer_head.h> /* for inode_has_buffers */ |
a66979ab | 29 | #include "internal.h" |
1da177e4 | 30 | |
250df6ed | 31 | /* |
4b4563dc | 32 | * Inode locking rules: |
250df6ed DC |
33 | * |
34 | * inode->i_lock protects: | |
35 | * inode->i_state, inode->i_hash, __iget() | |
02afc410 DC |
36 | * inode_lru_lock protects: |
37 | * inode_lru, inode->i_lru | |
55fa6091 DC |
38 | * inode_sb_list_lock protects: |
39 | * sb->s_inodes, inode->i_sb_list | |
a66979ab DC |
40 | * inode_wb_list_lock protects: |
41 | * bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list | |
67a23c49 DC |
42 | * inode_hash_lock protects: |
43 | * inode_hashtable, inode->i_hash | |
250df6ed DC |
44 | * |
45 | * Lock ordering: | |
55fa6091 DC |
46 | * |
47 | * inode_sb_list_lock | |
48 | * inode->i_lock | |
02afc410 | 49 | * inode_lru_lock |
a66979ab DC |
50 | * |
51 | * inode_wb_list_lock | |
52 | * inode->i_lock | |
67a23c49 DC |
53 | * |
54 | * inode_hash_lock | |
55 | * inode_sb_list_lock | |
56 | * inode->i_lock | |
57 | * | |
58 | * iunique_lock | |
59 | * inode_hash_lock | |
250df6ed DC |
60 | */ |
61 | ||
fa3536cc ED |
62 | static unsigned int i_hash_mask __read_mostly; |
63 | static unsigned int i_hash_shift __read_mostly; | |
67a23c49 DC |
64 | static struct hlist_head *inode_hashtable __read_mostly; |
65 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock); | |
1da177e4 | 66 | |
7ccf19a8 | 67 | static LIST_HEAD(inode_lru); |
02afc410 | 68 | static DEFINE_SPINLOCK(inode_lru_lock); |
1da177e4 | 69 | |
55fa6091 | 70 | __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock); |
a66979ab | 71 | __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_wb_list_lock); |
55fa6091 | 72 | |
1da177e4 | 73 | /* |
bab1d944 CH |
74 | * iprune_sem provides exclusion between the icache shrinking and the |
75 | * umount path. | |
88e0fbc4 | 76 | * |
bab1d944 CH |
77 | * We don't actually need it to protect anything in the umount path, |
78 | * but only need to cycle through it to make sure any inode that | |
79 | * prune_icache took off the LRU list has been fully torn down by the | |
80 | * time we are past evict_inodes. | |
1da177e4 | 81 | */ |
88e0fbc4 | 82 | static DECLARE_RWSEM(iprune_sem); |
1da177e4 | 83 | |
7dcda1c9 JA |
84 | /* |
85 | * Empty aops. Can be used for the cases where the user does not | |
86 | * define any of the address_space operations. | |
87 | */ | |
88 | const struct address_space_operations empty_aops = { | |
89 | }; | |
90 | EXPORT_SYMBOL(empty_aops); | |
91 | ||
1da177e4 LT |
92 | /* |
93 | * Statistics gathering.. | |
94 | */ | |
95 | struct inodes_stat_t inodes_stat; | |
96 | ||
3e880fb5 | 97 | static DEFINE_PER_CPU(unsigned int, nr_inodes); |
cffbc8aa | 98 | |
6b3304b5 | 99 | static struct kmem_cache *inode_cachep __read_mostly; |
1da177e4 | 100 | |
3e880fb5 | 101 | static int get_nr_inodes(void) |
cffbc8aa | 102 | { |
3e880fb5 NP |
103 | int i; |
104 | int sum = 0; | |
105 | for_each_possible_cpu(i) | |
106 | sum += per_cpu(nr_inodes, i); | |
107 | return sum < 0 ? 0 : sum; | |
cffbc8aa DC |
108 | } |
109 | ||
110 | static inline int get_nr_inodes_unused(void) | |
111 | { | |
86c8749e | 112 | return inodes_stat.nr_unused; |
cffbc8aa DC |
113 | } |
114 | ||
115 | int get_nr_dirty_inodes(void) | |
116 | { | |
3e880fb5 | 117 | /* not actually dirty inodes, but a wild approximation */ |
cffbc8aa DC |
118 | int nr_dirty = get_nr_inodes() - get_nr_inodes_unused(); |
119 | return nr_dirty > 0 ? nr_dirty : 0; | |
cffbc8aa DC |
120 | } |
121 | ||
122 | /* | |
123 | * Handle nr_inode sysctl | |
124 | */ | |
125 | #ifdef CONFIG_SYSCTL | |
126 | int proc_nr_inodes(ctl_table *table, int write, | |
127 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
128 | { | |
129 | inodes_stat.nr_inodes = get_nr_inodes(); | |
cffbc8aa DC |
130 | return proc_dointvec(table, write, buffer, lenp, ppos); |
131 | } | |
132 | #endif | |
133 | ||
2cb1599f DC |
134 | /** |
135 | * inode_init_always - perform inode structure intialisation | |
0bc02f3f RD |
136 | * @sb: superblock inode belongs to |
137 | * @inode: inode to initialise | |
2cb1599f DC |
138 | * |
139 | * These are initializations that need to be done on every inode | |
140 | * allocation as the fields are not initialised by slab allocation. | |
141 | */ | |
54e34621 | 142 | int inode_init_always(struct super_block *sb, struct inode *inode) |
1da177e4 | 143 | { |
6e1d5dcc | 144 | static const struct inode_operations empty_iops; |
99ac48f5 | 145 | static const struct file_operations empty_fops; |
6b3304b5 | 146 | struct address_space *const mapping = &inode->i_data; |
2cb1599f DC |
147 | |
148 | inode->i_sb = sb; | |
149 | inode->i_blkbits = sb->s_blocksize_bits; | |
150 | inode->i_flags = 0; | |
151 | atomic_set(&inode->i_count, 1); | |
152 | inode->i_op = &empty_iops; | |
153 | inode->i_fop = &empty_fops; | |
154 | inode->i_nlink = 1; | |
56ff5efa AV |
155 | inode->i_uid = 0; |
156 | inode->i_gid = 0; | |
2cb1599f DC |
157 | atomic_set(&inode->i_writecount, 0); |
158 | inode->i_size = 0; | |
159 | inode->i_blocks = 0; | |
160 | inode->i_bytes = 0; | |
161 | inode->i_generation = 0; | |
1da177e4 | 162 | #ifdef CONFIG_QUOTA |
2cb1599f | 163 | memset(&inode->i_dquot, 0, sizeof(inode->i_dquot)); |
1da177e4 | 164 | #endif |
2cb1599f DC |
165 | inode->i_pipe = NULL; |
166 | inode->i_bdev = NULL; | |
167 | inode->i_cdev = NULL; | |
168 | inode->i_rdev = 0; | |
169 | inode->dirtied_when = 0; | |
6146f0d5 MZ |
170 | |
171 | if (security_inode_alloc(inode)) | |
54e34621 | 172 | goto out; |
2cb1599f DC |
173 | spin_lock_init(&inode->i_lock); |
174 | lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key); | |
175 | ||
176 | mutex_init(&inode->i_mutex); | |
177 | lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key); | |
178 | ||
179 | init_rwsem(&inode->i_alloc_sem); | |
180 | lockdep_set_class(&inode->i_alloc_sem, &sb->s_type->i_alloc_sem_key); | |
181 | ||
182 | mapping->a_ops = &empty_aops; | |
183 | mapping->host = inode; | |
184 | mapping->flags = 0; | |
3c1d4378 | 185 | mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE); |
2cb1599f DC |
186 | mapping->assoc_mapping = NULL; |
187 | mapping->backing_dev_info = &default_backing_dev_info; | |
188 | mapping->writeback_index = 0; | |
189 | ||
190 | /* | |
191 | * If the block_device provides a backing_dev_info for client | |
192 | * inodes then use that. Otherwise the inode share the bdev's | |
193 | * backing_dev_info. | |
194 | */ | |
195 | if (sb->s_bdev) { | |
196 | struct backing_dev_info *bdi; | |
197 | ||
2c96ce9f | 198 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; |
2cb1599f DC |
199 | mapping->backing_dev_info = bdi; |
200 | } | |
201 | inode->i_private = NULL; | |
202 | inode->i_mapping = mapping; | |
f19d4a8f AV |
203 | #ifdef CONFIG_FS_POSIX_ACL |
204 | inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; | |
205 | #endif | |
2cb1599f | 206 | |
3be25f49 EP |
207 | #ifdef CONFIG_FSNOTIFY |
208 | inode->i_fsnotify_mask = 0; | |
209 | #endif | |
210 | ||
3e880fb5 | 211 | this_cpu_inc(nr_inodes); |
cffbc8aa | 212 | |
54e34621 | 213 | return 0; |
54e34621 CH |
214 | out: |
215 | return -ENOMEM; | |
1da177e4 | 216 | } |
2cb1599f DC |
217 | EXPORT_SYMBOL(inode_init_always); |
218 | ||
219 | static struct inode *alloc_inode(struct super_block *sb) | |
220 | { | |
221 | struct inode *inode; | |
222 | ||
223 | if (sb->s_op->alloc_inode) | |
224 | inode = sb->s_op->alloc_inode(sb); | |
225 | else | |
226 | inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL); | |
227 | ||
54e34621 CH |
228 | if (!inode) |
229 | return NULL; | |
230 | ||
231 | if (unlikely(inode_init_always(sb, inode))) { | |
232 | if (inode->i_sb->s_op->destroy_inode) | |
233 | inode->i_sb->s_op->destroy_inode(inode); | |
234 | else | |
235 | kmem_cache_free(inode_cachep, inode); | |
236 | return NULL; | |
237 | } | |
238 | ||
239 | return inode; | |
2cb1599f | 240 | } |
1da177e4 | 241 | |
ff0c7d15 NP |
242 | void free_inode_nonrcu(struct inode *inode) |
243 | { | |
244 | kmem_cache_free(inode_cachep, inode); | |
245 | } | |
246 | EXPORT_SYMBOL(free_inode_nonrcu); | |
247 | ||
2e00c97e | 248 | void __destroy_inode(struct inode *inode) |
1da177e4 | 249 | { |
b7542f8c | 250 | BUG_ON(inode_has_buffers(inode)); |
1da177e4 | 251 | security_inode_free(inode); |
3be25f49 | 252 | fsnotify_inode_delete(inode); |
f19d4a8f AV |
253 | #ifdef CONFIG_FS_POSIX_ACL |
254 | if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED) | |
255 | posix_acl_release(inode->i_acl); | |
256 | if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) | |
257 | posix_acl_release(inode->i_default_acl); | |
258 | #endif | |
3e880fb5 | 259 | this_cpu_dec(nr_inodes); |
2e00c97e CH |
260 | } |
261 | EXPORT_SYMBOL(__destroy_inode); | |
262 | ||
fa0d7e3d NP |
263 | static void i_callback(struct rcu_head *head) |
264 | { | |
265 | struct inode *inode = container_of(head, struct inode, i_rcu); | |
266 | INIT_LIST_HEAD(&inode->i_dentry); | |
267 | kmem_cache_free(inode_cachep, inode); | |
268 | } | |
269 | ||
56b0dacf | 270 | static void destroy_inode(struct inode *inode) |
2e00c97e | 271 | { |
7ccf19a8 | 272 | BUG_ON(!list_empty(&inode->i_lru)); |
2e00c97e | 273 | __destroy_inode(inode); |
1da177e4 LT |
274 | if (inode->i_sb->s_op->destroy_inode) |
275 | inode->i_sb->s_op->destroy_inode(inode); | |
276 | else | |
fa0d7e3d | 277 | call_rcu(&inode->i_rcu, i_callback); |
1da177e4 | 278 | } |
1da177e4 | 279 | |
2aa15890 MS |
280 | void address_space_init_once(struct address_space *mapping) |
281 | { | |
282 | memset(mapping, 0, sizeof(*mapping)); | |
283 | INIT_RADIX_TREE(&mapping->page_tree, GFP_ATOMIC); | |
284 | spin_lock_init(&mapping->tree_lock); | |
3d48ae45 | 285 | mutex_init(&mapping->i_mmap_mutex); |
2aa15890 MS |
286 | INIT_LIST_HEAD(&mapping->private_list); |
287 | spin_lock_init(&mapping->private_lock); | |
288 | INIT_RAW_PRIO_TREE_ROOT(&mapping->i_mmap); | |
289 | INIT_LIST_HEAD(&mapping->i_mmap_nonlinear); | |
2aa15890 MS |
290 | } |
291 | EXPORT_SYMBOL(address_space_init_once); | |
292 | ||
1da177e4 LT |
293 | /* |
294 | * These are initializations that only need to be done | |
295 | * once, because the fields are idempotent across use | |
296 | * of the inode, so let the slab aware of that. | |
297 | */ | |
298 | void inode_init_once(struct inode *inode) | |
299 | { | |
300 | memset(inode, 0, sizeof(*inode)); | |
301 | INIT_HLIST_NODE(&inode->i_hash); | |
302 | INIT_LIST_HEAD(&inode->i_dentry); | |
303 | INIT_LIST_HEAD(&inode->i_devices); | |
7ccf19a8 NP |
304 | INIT_LIST_HEAD(&inode->i_wb_list); |
305 | INIT_LIST_HEAD(&inode->i_lru); | |
2aa15890 | 306 | address_space_init_once(&inode->i_data); |
1da177e4 | 307 | i_size_ordered_init(inode); |
3be25f49 | 308 | #ifdef CONFIG_FSNOTIFY |
e61ce867 | 309 | INIT_HLIST_HEAD(&inode->i_fsnotify_marks); |
3be25f49 | 310 | #endif |
1da177e4 | 311 | } |
1da177e4 LT |
312 | EXPORT_SYMBOL(inode_init_once); |
313 | ||
51cc5068 | 314 | static void init_once(void *foo) |
1da177e4 | 315 | { |
6b3304b5 | 316 | struct inode *inode = (struct inode *) foo; |
1da177e4 | 317 | |
a35afb83 | 318 | inode_init_once(inode); |
1da177e4 LT |
319 | } |
320 | ||
321 | /* | |
250df6ed | 322 | * inode->i_lock must be held |
1da177e4 | 323 | */ |
6b3304b5 | 324 | void __iget(struct inode *inode) |
1da177e4 | 325 | { |
9e38d86f NP |
326 | atomic_inc(&inode->i_count); |
327 | } | |
2e147f1e | 328 | |
7de9c6ee AV |
329 | /* |
330 | * get additional reference to inode; caller must already hold one. | |
331 | */ | |
332 | void ihold(struct inode *inode) | |
333 | { | |
334 | WARN_ON(atomic_inc_return(&inode->i_count) < 2); | |
335 | } | |
336 | EXPORT_SYMBOL(ihold); | |
337 | ||
9e38d86f NP |
338 | static void inode_lru_list_add(struct inode *inode) |
339 | { | |
02afc410 | 340 | spin_lock(&inode_lru_lock); |
7ccf19a8 NP |
341 | if (list_empty(&inode->i_lru)) { |
342 | list_add(&inode->i_lru, &inode_lru); | |
86c8749e | 343 | inodes_stat.nr_unused++; |
9e38d86f | 344 | } |
02afc410 | 345 | spin_unlock(&inode_lru_lock); |
9e38d86f | 346 | } |
2e147f1e | 347 | |
9e38d86f NP |
348 | static void inode_lru_list_del(struct inode *inode) |
349 | { | |
02afc410 | 350 | spin_lock(&inode_lru_lock); |
7ccf19a8 NP |
351 | if (!list_empty(&inode->i_lru)) { |
352 | list_del_init(&inode->i_lru); | |
86c8749e | 353 | inodes_stat.nr_unused--; |
9e38d86f | 354 | } |
02afc410 | 355 | spin_unlock(&inode_lru_lock); |
1da177e4 LT |
356 | } |
357 | ||
646ec461 CH |
358 | /** |
359 | * inode_sb_list_add - add inode to the superblock list of inodes | |
360 | * @inode: inode to add | |
361 | */ | |
362 | void inode_sb_list_add(struct inode *inode) | |
363 | { | |
55fa6091 DC |
364 | spin_lock(&inode_sb_list_lock); |
365 | list_add(&inode->i_sb_list, &inode->i_sb->s_inodes); | |
366 | spin_unlock(&inode_sb_list_lock); | |
646ec461 CH |
367 | } |
368 | EXPORT_SYMBOL_GPL(inode_sb_list_add); | |
369 | ||
55fa6091 | 370 | static inline void inode_sb_list_del(struct inode *inode) |
646ec461 | 371 | { |
55fa6091 | 372 | spin_lock(&inode_sb_list_lock); |
646ec461 | 373 | list_del_init(&inode->i_sb_list); |
55fa6091 | 374 | spin_unlock(&inode_sb_list_lock); |
646ec461 CH |
375 | } |
376 | ||
4c51acbc DC |
377 | static unsigned long hash(struct super_block *sb, unsigned long hashval) |
378 | { | |
379 | unsigned long tmp; | |
380 | ||
381 | tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / | |
382 | L1_CACHE_BYTES; | |
4b4563dc CH |
383 | tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> i_hash_shift); |
384 | return tmp & i_hash_mask; | |
4c51acbc DC |
385 | } |
386 | ||
387 | /** | |
388 | * __insert_inode_hash - hash an inode | |
389 | * @inode: unhashed inode | |
390 | * @hashval: unsigned long value used to locate this object in the | |
391 | * inode_hashtable. | |
392 | * | |
393 | * Add an inode to the inode hash for this superblock. | |
394 | */ | |
395 | void __insert_inode_hash(struct inode *inode, unsigned long hashval) | |
396 | { | |
646ec461 CH |
397 | struct hlist_head *b = inode_hashtable + hash(inode->i_sb, hashval); |
398 | ||
67a23c49 | 399 | spin_lock(&inode_hash_lock); |
250df6ed | 400 | spin_lock(&inode->i_lock); |
646ec461 | 401 | hlist_add_head(&inode->i_hash, b); |
250df6ed | 402 | spin_unlock(&inode->i_lock); |
67a23c49 | 403 | spin_unlock(&inode_hash_lock); |
4c51acbc DC |
404 | } |
405 | EXPORT_SYMBOL(__insert_inode_hash); | |
406 | ||
4c51acbc DC |
407 | /** |
408 | * remove_inode_hash - remove an inode from the hash | |
409 | * @inode: inode to unhash | |
410 | * | |
411 | * Remove an inode from the superblock. | |
412 | */ | |
413 | void remove_inode_hash(struct inode *inode) | |
414 | { | |
67a23c49 | 415 | spin_lock(&inode_hash_lock); |
250df6ed | 416 | spin_lock(&inode->i_lock); |
4c51acbc | 417 | hlist_del_init(&inode->i_hash); |
250df6ed | 418 | spin_unlock(&inode->i_lock); |
67a23c49 | 419 | spin_unlock(&inode_hash_lock); |
4c51acbc DC |
420 | } |
421 | EXPORT_SYMBOL(remove_inode_hash); | |
422 | ||
b0683aa6 AV |
423 | void end_writeback(struct inode *inode) |
424 | { | |
425 | might_sleep(); | |
426 | BUG_ON(inode->i_data.nrpages); | |
427 | BUG_ON(!list_empty(&inode->i_data.private_list)); | |
428 | BUG_ON(!(inode->i_state & I_FREEING)); | |
429 | BUG_ON(inode->i_state & I_CLEAR); | |
430 | inode_sync_wait(inode); | |
fa0d7e3d | 431 | /* don't need i_lock here, no concurrent mods to i_state */ |
b0683aa6 AV |
432 | inode->i_state = I_FREEING | I_CLEAR; |
433 | } | |
434 | EXPORT_SYMBOL(end_writeback); | |
435 | ||
b2b2af8e DC |
436 | /* |
437 | * Free the inode passed in, removing it from the lists it is still connected | |
438 | * to. We remove any pages still attached to the inode and wait for any IO that | |
439 | * is still in progress before finally destroying the inode. | |
440 | * | |
441 | * An inode must already be marked I_FREEING so that we avoid the inode being | |
442 | * moved back onto lists if we race with other code that manipulates the lists | |
443 | * (e.g. writeback_single_inode). The caller is responsible for setting this. | |
444 | * | |
445 | * An inode must already be removed from the LRU list before being evicted from | |
446 | * the cache. This should occur atomically with setting the I_FREEING state | |
447 | * flag, so no inodes here should ever be on the LRU when being evicted. | |
448 | */ | |
644da596 | 449 | static void evict(struct inode *inode) |
b4272d4c AV |
450 | { |
451 | const struct super_operations *op = inode->i_sb->s_op; | |
452 | ||
b2b2af8e DC |
453 | BUG_ON(!(inode->i_state & I_FREEING)); |
454 | BUG_ON(!list_empty(&inode->i_lru)); | |
455 | ||
a66979ab | 456 | inode_wb_list_del(inode); |
55fa6091 DC |
457 | inode_sb_list_del(inode); |
458 | ||
be7ce416 AV |
459 | if (op->evict_inode) { |
460 | op->evict_inode(inode); | |
b4272d4c AV |
461 | } else { |
462 | if (inode->i_data.nrpages) | |
463 | truncate_inode_pages(&inode->i_data, 0); | |
30140837 | 464 | end_writeback(inode); |
b4272d4c | 465 | } |
661074e9 AV |
466 | if (S_ISBLK(inode->i_mode) && inode->i_bdev) |
467 | bd_forget(inode); | |
468 | if (S_ISCHR(inode->i_mode) && inode->i_cdev) | |
469 | cd_forget(inode); | |
b2b2af8e DC |
470 | |
471 | remove_inode_hash(inode); | |
472 | ||
473 | spin_lock(&inode->i_lock); | |
474 | wake_up_bit(&inode->i_state, __I_NEW); | |
475 | BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); | |
476 | spin_unlock(&inode->i_lock); | |
477 | ||
478 | destroy_inode(inode); | |
b4272d4c AV |
479 | } |
480 | ||
1da177e4 LT |
481 | /* |
482 | * dispose_list - dispose of the contents of a local list | |
483 | * @head: the head of the list to free | |
484 | * | |
485 | * Dispose-list gets a local list with local inodes in it, so it doesn't | |
486 | * need to worry about list corruption and SMP locks. | |
487 | */ | |
488 | static void dispose_list(struct list_head *head) | |
489 | { | |
1da177e4 LT |
490 | while (!list_empty(head)) { |
491 | struct inode *inode; | |
492 | ||
7ccf19a8 NP |
493 | inode = list_first_entry(head, struct inode, i_lru); |
494 | list_del_init(&inode->i_lru); | |
1da177e4 | 495 | |
644da596 | 496 | evict(inode); |
1da177e4 | 497 | } |
1da177e4 LT |
498 | } |
499 | ||
63997e98 AV |
500 | /** |
501 | * evict_inodes - evict all evictable inodes for a superblock | |
502 | * @sb: superblock to operate on | |
503 | * | |
504 | * Make sure that no inodes with zero refcount are retained. This is | |
505 | * called by superblock shutdown after having MS_ACTIVE flag removed, | |
506 | * so any inode reaching zero refcount during or after that call will | |
507 | * be immediately evicted. | |
1da177e4 | 508 | */ |
63997e98 | 509 | void evict_inodes(struct super_block *sb) |
1da177e4 | 510 | { |
63997e98 AV |
511 | struct inode *inode, *next; |
512 | LIST_HEAD(dispose); | |
1da177e4 | 513 | |
55fa6091 | 514 | spin_lock(&inode_sb_list_lock); |
63997e98 AV |
515 | list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { |
516 | if (atomic_read(&inode->i_count)) | |
aabb8fdb | 517 | continue; |
250df6ed DC |
518 | |
519 | spin_lock(&inode->i_lock); | |
520 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { | |
521 | spin_unlock(&inode->i_lock); | |
1da177e4 | 522 | continue; |
250df6ed | 523 | } |
63997e98 AV |
524 | |
525 | inode->i_state |= I_FREEING; | |
02afc410 | 526 | inode_lru_list_del(inode); |
250df6ed | 527 | spin_unlock(&inode->i_lock); |
02afc410 | 528 | list_add(&inode->i_lru, &dispose); |
1da177e4 | 529 | } |
55fa6091 | 530 | spin_unlock(&inode_sb_list_lock); |
63997e98 AV |
531 | |
532 | dispose_list(&dispose); | |
bab1d944 CH |
533 | |
534 | /* | |
535 | * Cycle through iprune_sem to make sure any inode that prune_icache | |
536 | * moved off the list before we took the lock has been fully torn | |
537 | * down. | |
538 | */ | |
539 | down_write(&iprune_sem); | |
63997e98 | 540 | up_write(&iprune_sem); |
1da177e4 LT |
541 | } |
542 | ||
1da177e4 | 543 | /** |
a0318786 CH |
544 | * invalidate_inodes - attempt to free all inodes on a superblock |
545 | * @sb: superblock to operate on | |
93b270f7 | 546 | * @kill_dirty: flag to guide handling of dirty inodes |
1da177e4 | 547 | * |
a0318786 CH |
548 | * Attempts to free all inodes for a given superblock. If there were any |
549 | * busy inodes return a non-zero value, else zero. | |
93b270f7 N |
550 | * If @kill_dirty is set, discard dirty inodes too, otherwise treat |
551 | * them as busy. | |
1da177e4 | 552 | */ |
93b270f7 | 553 | int invalidate_inodes(struct super_block *sb, bool kill_dirty) |
1da177e4 | 554 | { |
cffbc8aa | 555 | int busy = 0; |
a0318786 CH |
556 | struct inode *inode, *next; |
557 | LIST_HEAD(dispose); | |
1da177e4 | 558 | |
55fa6091 | 559 | spin_lock(&inode_sb_list_lock); |
a0318786 | 560 | list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { |
250df6ed DC |
561 | spin_lock(&inode->i_lock); |
562 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { | |
563 | spin_unlock(&inode->i_lock); | |
aabb8fdb | 564 | continue; |
250df6ed | 565 | } |
93b270f7 | 566 | if (inode->i_state & I_DIRTY && !kill_dirty) { |
250df6ed | 567 | spin_unlock(&inode->i_lock); |
93b270f7 N |
568 | busy = 1; |
569 | continue; | |
570 | } | |
99a38919 | 571 | if (atomic_read(&inode->i_count)) { |
250df6ed | 572 | spin_unlock(&inode->i_lock); |
99a38919 | 573 | busy = 1; |
1da177e4 LT |
574 | continue; |
575 | } | |
99a38919 | 576 | |
99a38919 | 577 | inode->i_state |= I_FREEING; |
02afc410 | 578 | inode_lru_list_del(inode); |
250df6ed | 579 | spin_unlock(&inode->i_lock); |
02afc410 | 580 | list_add(&inode->i_lru, &dispose); |
1da177e4 | 581 | } |
55fa6091 | 582 | spin_unlock(&inode_sb_list_lock); |
1da177e4 | 583 | |
a0318786 | 584 | dispose_list(&dispose); |
1da177e4 LT |
585 | |
586 | return busy; | |
587 | } | |
1da177e4 LT |
588 | |
589 | static int can_unuse(struct inode *inode) | |
590 | { | |
9e38d86f | 591 | if (inode->i_state & ~I_REFERENCED) |
1da177e4 LT |
592 | return 0; |
593 | if (inode_has_buffers(inode)) | |
594 | return 0; | |
595 | if (atomic_read(&inode->i_count)) | |
596 | return 0; | |
597 | if (inode->i_data.nrpages) | |
598 | return 0; | |
599 | return 1; | |
600 | } | |
601 | ||
602 | /* | |
9e38d86f | 603 | * Scan `goal' inodes on the unused list for freeable ones. They are moved to a |
02afc410 | 604 | * temporary list and then are freed outside inode_lru_lock by dispose_list(). |
1da177e4 LT |
605 | * |
606 | * Any inodes which are pinned purely because of attached pagecache have their | |
9e38d86f NP |
607 | * pagecache removed. If the inode has metadata buffers attached to |
608 | * mapping->private_list then try to remove them. | |
1da177e4 | 609 | * |
9e38d86f NP |
610 | * If the inode has the I_REFERENCED flag set, then it means that it has been |
611 | * used recently - the flag is set in iput_final(). When we encounter such an | |
612 | * inode, clear the flag and move it to the back of the LRU so it gets another | |
613 | * pass through the LRU before it gets reclaimed. This is necessary because of | |
614 | * the fact we are doing lazy LRU updates to minimise lock contention so the | |
615 | * LRU does not have strict ordering. Hence we don't want to reclaim inodes | |
616 | * with this flag set because they are the inodes that are out of order. | |
1da177e4 LT |
617 | */ |
618 | static void prune_icache(int nr_to_scan) | |
619 | { | |
620 | LIST_HEAD(freeable); | |
1da177e4 LT |
621 | int nr_scanned; |
622 | unsigned long reap = 0; | |
623 | ||
88e0fbc4 | 624 | down_read(&iprune_sem); |
02afc410 | 625 | spin_lock(&inode_lru_lock); |
1da177e4 LT |
626 | for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { |
627 | struct inode *inode; | |
628 | ||
7ccf19a8 | 629 | if (list_empty(&inode_lru)) |
1da177e4 LT |
630 | break; |
631 | ||
7ccf19a8 | 632 | inode = list_entry(inode_lru.prev, struct inode, i_lru); |
1da177e4 | 633 | |
02afc410 DC |
634 | /* |
635 | * we are inverting the inode_lru_lock/inode->i_lock here, | |
636 | * so use a trylock. If we fail to get the lock, just move the | |
637 | * inode to the back of the list so we don't spin on it. | |
638 | */ | |
639 | if (!spin_trylock(&inode->i_lock)) { | |
640 | list_move(&inode->i_lru, &inode_lru); | |
641 | continue; | |
642 | } | |
643 | ||
9e38d86f NP |
644 | /* |
645 | * Referenced or dirty inodes are still in use. Give them | |
646 | * another pass through the LRU as we canot reclaim them now. | |
647 | */ | |
648 | if (atomic_read(&inode->i_count) || | |
649 | (inode->i_state & ~I_REFERENCED)) { | |
7ccf19a8 | 650 | list_del_init(&inode->i_lru); |
f283c86a | 651 | spin_unlock(&inode->i_lock); |
86c8749e | 652 | inodes_stat.nr_unused--; |
9e38d86f NP |
653 | continue; |
654 | } | |
655 | ||
656 | /* recently referenced inodes get one more pass */ | |
657 | if (inode->i_state & I_REFERENCED) { | |
9e38d86f | 658 | inode->i_state &= ~I_REFERENCED; |
250df6ed | 659 | list_move(&inode->i_lru, &inode_lru); |
f283c86a | 660 | spin_unlock(&inode->i_lock); |
1da177e4 LT |
661 | continue; |
662 | } | |
663 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { | |
664 | __iget(inode); | |
250df6ed | 665 | spin_unlock(&inode->i_lock); |
02afc410 | 666 | spin_unlock(&inode_lru_lock); |
1da177e4 | 667 | if (remove_inode_buffers(inode)) |
fc0ecff6 AM |
668 | reap += invalidate_mapping_pages(&inode->i_data, |
669 | 0, -1); | |
1da177e4 | 670 | iput(inode); |
02afc410 | 671 | spin_lock(&inode_lru_lock); |
1da177e4 | 672 | |
7ccf19a8 NP |
673 | if (inode != list_entry(inode_lru.next, |
674 | struct inode, i_lru)) | |
1da177e4 | 675 | continue; /* wrong inode or list_empty */ |
02afc410 DC |
676 | /* avoid lock inversions with trylock */ |
677 | if (!spin_trylock(&inode->i_lock)) | |
678 | continue; | |
250df6ed DC |
679 | if (!can_unuse(inode)) { |
680 | spin_unlock(&inode->i_lock); | |
1da177e4 | 681 | continue; |
250df6ed | 682 | } |
1da177e4 | 683 | } |
7ef0d737 | 684 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 | 685 | inode->i_state |= I_FREEING; |
250df6ed | 686 | spin_unlock(&inode->i_lock); |
7ccf19a8 | 687 | |
7ccf19a8 | 688 | list_move(&inode->i_lru, &freeable); |
86c8749e | 689 | inodes_stat.nr_unused--; |
1da177e4 | 690 | } |
f8891e5e CL |
691 | if (current_is_kswapd()) |
692 | __count_vm_events(KSWAPD_INODESTEAL, reap); | |
693 | else | |
694 | __count_vm_events(PGINODESTEAL, reap); | |
02afc410 | 695 | spin_unlock(&inode_lru_lock); |
1da177e4 LT |
696 | |
697 | dispose_list(&freeable); | |
88e0fbc4 | 698 | up_read(&iprune_sem); |
1da177e4 LT |
699 | } |
700 | ||
701 | /* | |
702 | * shrink_icache_memory() will attempt to reclaim some unused inodes. Here, | |
703 | * "unused" means that no dentries are referring to the inodes: the files are | |
704 | * not open and the dcache references to those inodes have already been | |
705 | * reclaimed. | |
706 | * | |
707 | * This function is passed the number of inodes to scan, and it returns the | |
708 | * total number of remaining possibly-reclaimable inodes. | |
709 | */ | |
1495f230 YH |
710 | static int shrink_icache_memory(struct shrinker *shrink, |
711 | struct shrink_control *sc) | |
1da177e4 | 712 | { |
1495f230 YH |
713 | int nr = sc->nr_to_scan; |
714 | gfp_t gfp_mask = sc->gfp_mask; | |
715 | ||
1da177e4 LT |
716 | if (nr) { |
717 | /* | |
718 | * Nasty deadlock avoidance. We may hold various FS locks, | |
719 | * and we don't want to recurse into the FS that called us | |
720 | * in clear_inode() and friends.. | |
6b3304b5 | 721 | */ |
1da177e4 LT |
722 | if (!(gfp_mask & __GFP_FS)) |
723 | return -1; | |
724 | prune_icache(nr); | |
725 | } | |
cffbc8aa | 726 | return (get_nr_inodes_unused() / 100) * sysctl_vfs_cache_pressure; |
1da177e4 LT |
727 | } |
728 | ||
8e1f936b RR |
729 | static struct shrinker icache_shrinker = { |
730 | .shrink = shrink_icache_memory, | |
731 | .seeks = DEFAULT_SEEKS, | |
732 | }; | |
733 | ||
1da177e4 LT |
734 | static void __wait_on_freeing_inode(struct inode *inode); |
735 | /* | |
736 | * Called with the inode lock held. | |
1da177e4 | 737 | */ |
6b3304b5 MK |
738 | static struct inode *find_inode(struct super_block *sb, |
739 | struct hlist_head *head, | |
740 | int (*test)(struct inode *, void *), | |
741 | void *data) | |
1da177e4 LT |
742 | { |
743 | struct hlist_node *node; | |
6b3304b5 | 744 | struct inode *inode = NULL; |
1da177e4 LT |
745 | |
746 | repeat: | |
c5c8be3c | 747 | hlist_for_each_entry(inode, node, head, i_hash) { |
67a23c49 DC |
748 | spin_lock(&inode->i_lock); |
749 | if (inode->i_sb != sb) { | |
750 | spin_unlock(&inode->i_lock); | |
1da177e4 | 751 | continue; |
67a23c49 DC |
752 | } |
753 | if (!test(inode, data)) { | |
754 | spin_unlock(&inode->i_lock); | |
1da177e4 | 755 | continue; |
67a23c49 | 756 | } |
a4ffdde6 | 757 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
1da177e4 LT |
758 | __wait_on_freeing_inode(inode); |
759 | goto repeat; | |
760 | } | |
f7899bd5 | 761 | __iget(inode); |
250df6ed | 762 | spin_unlock(&inode->i_lock); |
f7899bd5 | 763 | return inode; |
1da177e4 | 764 | } |
f7899bd5 | 765 | return NULL; |
1da177e4 LT |
766 | } |
767 | ||
768 | /* | |
769 | * find_inode_fast is the fast path version of find_inode, see the comment at | |
770 | * iget_locked for details. | |
771 | */ | |
6b3304b5 MK |
772 | static struct inode *find_inode_fast(struct super_block *sb, |
773 | struct hlist_head *head, unsigned long ino) | |
1da177e4 LT |
774 | { |
775 | struct hlist_node *node; | |
6b3304b5 | 776 | struct inode *inode = NULL; |
1da177e4 LT |
777 | |
778 | repeat: | |
c5c8be3c | 779 | hlist_for_each_entry(inode, node, head, i_hash) { |
67a23c49 DC |
780 | spin_lock(&inode->i_lock); |
781 | if (inode->i_ino != ino) { | |
782 | spin_unlock(&inode->i_lock); | |
1da177e4 | 783 | continue; |
67a23c49 DC |
784 | } |
785 | if (inode->i_sb != sb) { | |
786 | spin_unlock(&inode->i_lock); | |
1da177e4 | 787 | continue; |
67a23c49 | 788 | } |
a4ffdde6 | 789 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) { |
1da177e4 LT |
790 | __wait_on_freeing_inode(inode); |
791 | goto repeat; | |
792 | } | |
f7899bd5 | 793 | __iget(inode); |
250df6ed | 794 | spin_unlock(&inode->i_lock); |
f7899bd5 | 795 | return inode; |
1da177e4 | 796 | } |
f7899bd5 | 797 | return NULL; |
8290c35f DC |
798 | } |
799 | ||
f991bd2e ED |
800 | /* |
801 | * Each cpu owns a range of LAST_INO_BATCH numbers. | |
802 | * 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations, | |
803 | * to renew the exhausted range. | |
8290c35f | 804 | * |
f991bd2e ED |
805 | * This does not significantly increase overflow rate because every CPU can |
806 | * consume at most LAST_INO_BATCH-1 unused inode numbers. So there is | |
807 | * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the | |
808 | * 2^32 range, and is a worst-case. Even a 50% wastage would only increase | |
809 | * overflow rate by 2x, which does not seem too significant. | |
810 | * | |
811 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
812 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
813 | * here to attempt to avoid that. | |
8290c35f | 814 | */ |
f991bd2e ED |
815 | #define LAST_INO_BATCH 1024 |
816 | static DEFINE_PER_CPU(unsigned int, last_ino); | |
817 | ||
85fe4025 | 818 | unsigned int get_next_ino(void) |
8290c35f | 819 | { |
f991bd2e ED |
820 | unsigned int *p = &get_cpu_var(last_ino); |
821 | unsigned int res = *p; | |
8290c35f | 822 | |
f991bd2e ED |
823 | #ifdef CONFIG_SMP |
824 | if (unlikely((res & (LAST_INO_BATCH-1)) == 0)) { | |
825 | static atomic_t shared_last_ino; | |
826 | int next = atomic_add_return(LAST_INO_BATCH, &shared_last_ino); | |
827 | ||
828 | res = next - LAST_INO_BATCH; | |
829 | } | |
830 | #endif | |
831 | ||
832 | *p = ++res; | |
833 | put_cpu_var(last_ino); | |
834 | return res; | |
8290c35f | 835 | } |
85fe4025 | 836 | EXPORT_SYMBOL(get_next_ino); |
8290c35f | 837 | |
1da177e4 LT |
838 | /** |
839 | * new_inode - obtain an inode | |
840 | * @sb: superblock | |
841 | * | |
769848c0 | 842 | * Allocates a new inode for given superblock. The default gfp_mask |
3c1d4378 | 843 | * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE. |
769848c0 MG |
844 | * If HIGHMEM pages are unsuitable or it is known that pages allocated |
845 | * for the page cache are not reclaimable or migratable, | |
846 | * mapping_set_gfp_mask() must be called with suitable flags on the | |
847 | * newly created inode's mapping | |
848 | * | |
1da177e4 LT |
849 | */ |
850 | struct inode *new_inode(struct super_block *sb) | |
851 | { | |
6b3304b5 | 852 | struct inode *inode; |
1da177e4 | 853 | |
55fa6091 | 854 | spin_lock_prefetch(&inode_sb_list_lock); |
6b3304b5 | 855 | |
1da177e4 LT |
856 | inode = alloc_inode(sb); |
857 | if (inode) { | |
250df6ed | 858 | spin_lock(&inode->i_lock); |
1da177e4 | 859 | inode->i_state = 0; |
250df6ed | 860 | spin_unlock(&inode->i_lock); |
55fa6091 | 861 | inode_sb_list_add(inode); |
1da177e4 LT |
862 | } |
863 | return inode; | |
864 | } | |
1da177e4 LT |
865 | EXPORT_SYMBOL(new_inode); |
866 | ||
250df6ed DC |
867 | /** |
868 | * unlock_new_inode - clear the I_NEW state and wake up any waiters | |
869 | * @inode: new inode to unlock | |
870 | * | |
871 | * Called when the inode is fully initialised to clear the new state of the | |
872 | * inode and wake up anyone waiting for the inode to finish initialisation. | |
873 | */ | |
1da177e4 LT |
874 | void unlock_new_inode(struct inode *inode) |
875 | { | |
14358e6d | 876 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
a3314a0e | 877 | if (S_ISDIR(inode->i_mode)) { |
1e89a5e1 PZ |
878 | struct file_system_type *type = inode->i_sb->s_type; |
879 | ||
9a7aa12f JK |
880 | /* Set new key only if filesystem hasn't already changed it */ |
881 | if (!lockdep_match_class(&inode->i_mutex, | |
882 | &type->i_mutex_key)) { | |
883 | /* | |
884 | * ensure nobody is actually holding i_mutex | |
885 | */ | |
886 | mutex_destroy(&inode->i_mutex); | |
887 | mutex_init(&inode->i_mutex); | |
888 | lockdep_set_class(&inode->i_mutex, | |
889 | &type->i_mutex_dir_key); | |
890 | } | |
1e89a5e1 | 891 | } |
14358e6d | 892 | #endif |
250df6ed | 893 | spin_lock(&inode->i_lock); |
eaff8079 CH |
894 | WARN_ON(!(inode->i_state & I_NEW)); |
895 | inode->i_state &= ~I_NEW; | |
250df6ed DC |
896 | wake_up_bit(&inode->i_state, __I_NEW); |
897 | spin_unlock(&inode->i_lock); | |
1da177e4 | 898 | } |
1da177e4 LT |
899 | EXPORT_SYMBOL(unlock_new_inode); |
900 | ||
0b2d0724 CH |
901 | /** |
902 | * iget5_locked - obtain an inode from a mounted file system | |
903 | * @sb: super block of file system | |
904 | * @hashval: hash value (usually inode number) to get | |
905 | * @test: callback used for comparisons between inodes | |
906 | * @set: callback used to initialize a new struct inode | |
907 | * @data: opaque data pointer to pass to @test and @set | |
908 | * | |
909 | * Search for the inode specified by @hashval and @data in the inode cache, | |
910 | * and if present it is return it with an increased reference count. This is | |
911 | * a generalized version of iget_locked() for file systems where the inode | |
912 | * number is not sufficient for unique identification of an inode. | |
913 | * | |
914 | * If the inode is not in cache, allocate a new inode and return it locked, | |
915 | * hashed, and with the I_NEW flag set. The file system gets to fill it in | |
916 | * before unlocking it via unlock_new_inode(). | |
1da177e4 | 917 | * |
0b2d0724 CH |
918 | * Note both @test and @set are called with the inode_hash_lock held, so can't |
919 | * sleep. | |
1da177e4 | 920 | */ |
0b2d0724 CH |
921 | struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, |
922 | int (*test)(struct inode *, void *), | |
923 | int (*set)(struct inode *, void *), void *data) | |
1da177e4 | 924 | { |
0b2d0724 | 925 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); |
6b3304b5 | 926 | struct inode *inode; |
1da177e4 | 927 | |
0b2d0724 CH |
928 | spin_lock(&inode_hash_lock); |
929 | inode = find_inode(sb, head, test, data); | |
930 | spin_unlock(&inode_hash_lock); | |
931 | ||
932 | if (inode) { | |
933 | wait_on_inode(inode); | |
934 | return inode; | |
935 | } | |
936 | ||
1da177e4 LT |
937 | inode = alloc_inode(sb); |
938 | if (inode) { | |
6b3304b5 | 939 | struct inode *old; |
1da177e4 | 940 | |
67a23c49 | 941 | spin_lock(&inode_hash_lock); |
1da177e4 LT |
942 | /* We released the lock, so.. */ |
943 | old = find_inode(sb, head, test, data); | |
944 | if (!old) { | |
945 | if (set(inode, data)) | |
946 | goto set_failed; | |
947 | ||
250df6ed DC |
948 | spin_lock(&inode->i_lock); |
949 | inode->i_state = I_NEW; | |
646ec461 | 950 | hlist_add_head(&inode->i_hash, head); |
250df6ed | 951 | spin_unlock(&inode->i_lock); |
55fa6091 | 952 | inode_sb_list_add(inode); |
67a23c49 | 953 | spin_unlock(&inode_hash_lock); |
1da177e4 LT |
954 | |
955 | /* Return the locked inode with I_NEW set, the | |
956 | * caller is responsible for filling in the contents | |
957 | */ | |
958 | return inode; | |
959 | } | |
960 | ||
961 | /* | |
962 | * Uhhuh, somebody else created the same inode under | |
963 | * us. Use the old inode instead of the one we just | |
964 | * allocated. | |
965 | */ | |
67a23c49 | 966 | spin_unlock(&inode_hash_lock); |
1da177e4 LT |
967 | destroy_inode(inode); |
968 | inode = old; | |
969 | wait_on_inode(inode); | |
970 | } | |
971 | return inode; | |
972 | ||
973 | set_failed: | |
67a23c49 | 974 | spin_unlock(&inode_hash_lock); |
1da177e4 LT |
975 | destroy_inode(inode); |
976 | return NULL; | |
977 | } | |
0b2d0724 | 978 | EXPORT_SYMBOL(iget5_locked); |
1da177e4 | 979 | |
0b2d0724 CH |
980 | /** |
981 | * iget_locked - obtain an inode from a mounted file system | |
982 | * @sb: super block of file system | |
983 | * @ino: inode number to get | |
984 | * | |
985 | * Search for the inode specified by @ino in the inode cache and if present | |
986 | * return it with an increased reference count. This is for file systems | |
987 | * where the inode number is sufficient for unique identification of an inode. | |
988 | * | |
989 | * If the inode is not in cache, allocate a new inode and return it locked, | |
990 | * hashed, and with the I_NEW flag set. The file system gets to fill it in | |
991 | * before unlocking it via unlock_new_inode(). | |
1da177e4 | 992 | */ |
0b2d0724 | 993 | struct inode *iget_locked(struct super_block *sb, unsigned long ino) |
1da177e4 | 994 | { |
0b2d0724 | 995 | struct hlist_head *head = inode_hashtable + hash(sb, ino); |
6b3304b5 | 996 | struct inode *inode; |
1da177e4 | 997 | |
0b2d0724 CH |
998 | spin_lock(&inode_hash_lock); |
999 | inode = find_inode_fast(sb, head, ino); | |
1000 | spin_unlock(&inode_hash_lock); | |
1001 | if (inode) { | |
1002 | wait_on_inode(inode); | |
1003 | return inode; | |
1004 | } | |
1005 | ||
1da177e4 LT |
1006 | inode = alloc_inode(sb); |
1007 | if (inode) { | |
6b3304b5 | 1008 | struct inode *old; |
1da177e4 | 1009 | |
67a23c49 | 1010 | spin_lock(&inode_hash_lock); |
1da177e4 LT |
1011 | /* We released the lock, so.. */ |
1012 | old = find_inode_fast(sb, head, ino); | |
1013 | if (!old) { | |
1014 | inode->i_ino = ino; | |
250df6ed DC |
1015 | spin_lock(&inode->i_lock); |
1016 | inode->i_state = I_NEW; | |
646ec461 | 1017 | hlist_add_head(&inode->i_hash, head); |
250df6ed | 1018 | spin_unlock(&inode->i_lock); |
55fa6091 | 1019 | inode_sb_list_add(inode); |
67a23c49 | 1020 | spin_unlock(&inode_hash_lock); |
1da177e4 LT |
1021 | |
1022 | /* Return the locked inode with I_NEW set, the | |
1023 | * caller is responsible for filling in the contents | |
1024 | */ | |
1025 | return inode; | |
1026 | } | |
1027 | ||
1028 | /* | |
1029 | * Uhhuh, somebody else created the same inode under | |
1030 | * us. Use the old inode instead of the one we just | |
1031 | * allocated. | |
1032 | */ | |
67a23c49 | 1033 | spin_unlock(&inode_hash_lock); |
1da177e4 LT |
1034 | destroy_inode(inode); |
1035 | inode = old; | |
1036 | wait_on_inode(inode); | |
1037 | } | |
1038 | return inode; | |
1039 | } | |
0b2d0724 | 1040 | EXPORT_SYMBOL(iget_locked); |
1da177e4 | 1041 | |
ad5e195a CH |
1042 | /* |
1043 | * search the inode cache for a matching inode number. | |
1044 | * If we find one, then the inode number we are trying to | |
1045 | * allocate is not unique and so we should not use it. | |
1046 | * | |
1047 | * Returns 1 if the inode number is unique, 0 if it is not. | |
1048 | */ | |
1049 | static int test_inode_iunique(struct super_block *sb, unsigned long ino) | |
1050 | { | |
1051 | struct hlist_head *b = inode_hashtable + hash(sb, ino); | |
1052 | struct hlist_node *node; | |
1053 | struct inode *inode; | |
1054 | ||
67a23c49 | 1055 | spin_lock(&inode_hash_lock); |
ad5e195a | 1056 | hlist_for_each_entry(inode, node, b, i_hash) { |
67a23c49 DC |
1057 | if (inode->i_ino == ino && inode->i_sb == sb) { |
1058 | spin_unlock(&inode_hash_lock); | |
ad5e195a | 1059 | return 0; |
67a23c49 | 1060 | } |
ad5e195a | 1061 | } |
67a23c49 | 1062 | spin_unlock(&inode_hash_lock); |
ad5e195a CH |
1063 | |
1064 | return 1; | |
1065 | } | |
1066 | ||
1da177e4 LT |
1067 | /** |
1068 | * iunique - get a unique inode number | |
1069 | * @sb: superblock | |
1070 | * @max_reserved: highest reserved inode number | |
1071 | * | |
1072 | * Obtain an inode number that is unique on the system for a given | |
1073 | * superblock. This is used by file systems that have no natural | |
1074 | * permanent inode numbering system. An inode number is returned that | |
1075 | * is higher than the reserved limit but unique. | |
1076 | * | |
1077 | * BUGS: | |
1078 | * With a large number of inodes live on the file system this function | |
1079 | * currently becomes quite slow. | |
1080 | */ | |
1081 | ino_t iunique(struct super_block *sb, ino_t max_reserved) | |
1082 | { | |
866b04fc JL |
1083 | /* |
1084 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
1085 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
1086 | * here to attempt to avoid that. | |
1087 | */ | |
ad5e195a | 1088 | static DEFINE_SPINLOCK(iunique_lock); |
866b04fc | 1089 | static unsigned int counter; |
1da177e4 | 1090 | ino_t res; |
3361c7be | 1091 | |
ad5e195a | 1092 | spin_lock(&iunique_lock); |
3361c7be JL |
1093 | do { |
1094 | if (counter <= max_reserved) | |
1095 | counter = max_reserved + 1; | |
1da177e4 | 1096 | res = counter++; |
ad5e195a CH |
1097 | } while (!test_inode_iunique(sb, res)); |
1098 | spin_unlock(&iunique_lock); | |
1da177e4 | 1099 | |
3361c7be JL |
1100 | return res; |
1101 | } | |
1da177e4 LT |
1102 | EXPORT_SYMBOL(iunique); |
1103 | ||
1104 | struct inode *igrab(struct inode *inode) | |
1105 | { | |
250df6ed DC |
1106 | spin_lock(&inode->i_lock); |
1107 | if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) { | |
1da177e4 | 1108 | __iget(inode); |
250df6ed DC |
1109 | spin_unlock(&inode->i_lock); |
1110 | } else { | |
1111 | spin_unlock(&inode->i_lock); | |
1da177e4 LT |
1112 | /* |
1113 | * Handle the case where s_op->clear_inode is not been | |
1114 | * called yet, and somebody is calling igrab | |
1115 | * while the inode is getting freed. | |
1116 | */ | |
1117 | inode = NULL; | |
250df6ed | 1118 | } |
1da177e4 LT |
1119 | return inode; |
1120 | } | |
1da177e4 LT |
1121 | EXPORT_SYMBOL(igrab); |
1122 | ||
1123 | /** | |
0b2d0724 | 1124 | * ilookup5_nowait - search for an inode in the inode cache |
1da177e4 | 1125 | * @sb: super block of file system to search |
0b2d0724 | 1126 | * @hashval: hash value (usually inode number) to search for |
1da177e4 LT |
1127 | * @test: callback used for comparisons between inodes |
1128 | * @data: opaque data pointer to pass to @test | |
1da177e4 | 1129 | * |
0b2d0724 | 1130 | * Search for the inode specified by @hashval and @data in the inode cache. |
1da177e4 LT |
1131 | * If the inode is in the cache, the inode is returned with an incremented |
1132 | * reference count. | |
1133 | * | |
0b2d0724 CH |
1134 | * Note: I_NEW is not waited upon so you have to be very careful what you do |
1135 | * with the returned inode. You probably should be using ilookup5() instead. | |
1da177e4 | 1136 | * |
b6d0ad68 | 1137 | * Note2: @test is called with the inode_hash_lock held, so can't sleep. |
1da177e4 | 1138 | */ |
0b2d0724 CH |
1139 | struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, |
1140 | int (*test)(struct inode *, void *), void *data) | |
1da177e4 | 1141 | { |
0b2d0724 | 1142 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); |
1da177e4 LT |
1143 | struct inode *inode; |
1144 | ||
67a23c49 | 1145 | spin_lock(&inode_hash_lock); |
1da177e4 | 1146 | inode = find_inode(sb, head, test, data); |
67a23c49 | 1147 | spin_unlock(&inode_hash_lock); |
88bd5121 | 1148 | |
0b2d0724 | 1149 | return inode; |
88bd5121 | 1150 | } |
88bd5121 AA |
1151 | EXPORT_SYMBOL(ilookup5_nowait); |
1152 | ||
1153 | /** | |
1154 | * ilookup5 - search for an inode in the inode cache | |
1155 | * @sb: super block of file system to search | |
1156 | * @hashval: hash value (usually inode number) to search for | |
1157 | * @test: callback used for comparisons between inodes | |
1158 | * @data: opaque data pointer to pass to @test | |
1159 | * | |
0b2d0724 CH |
1160 | * Search for the inode specified by @hashval and @data in the inode cache, |
1161 | * and if the inode is in the cache, return the inode with an incremented | |
1162 | * reference count. Waits on I_NEW before returning the inode. | |
88bd5121 | 1163 | * returned with an incremented reference count. |
1da177e4 | 1164 | * |
0b2d0724 CH |
1165 | * This is a generalized version of ilookup() for file systems where the |
1166 | * inode number is not sufficient for unique identification of an inode. | |
1da177e4 | 1167 | * |
0b2d0724 | 1168 | * Note: @test is called with the inode_hash_lock held, so can't sleep. |
1da177e4 LT |
1169 | */ |
1170 | struct inode *ilookup5(struct super_block *sb, unsigned long hashval, | |
1171 | int (*test)(struct inode *, void *), void *data) | |
1172 | { | |
0b2d0724 | 1173 | struct inode *inode = ilookup5_nowait(sb, hashval, test, data); |
1da177e4 | 1174 | |
0b2d0724 CH |
1175 | if (inode) |
1176 | wait_on_inode(inode); | |
1177 | return inode; | |
1da177e4 | 1178 | } |
1da177e4 LT |
1179 | EXPORT_SYMBOL(ilookup5); |
1180 | ||
1181 | /** | |
1182 | * ilookup - search for an inode in the inode cache | |
1183 | * @sb: super block of file system to search | |
1184 | * @ino: inode number to search for | |
1185 | * | |
0b2d0724 CH |
1186 | * Search for the inode @ino in the inode cache, and if the inode is in the |
1187 | * cache, the inode is returned with an incremented reference count. | |
1da177e4 LT |
1188 | */ |
1189 | struct inode *ilookup(struct super_block *sb, unsigned long ino) | |
1190 | { | |
1191 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
1da177e4 LT |
1192 | struct inode *inode; |
1193 | ||
0b2d0724 CH |
1194 | spin_lock(&inode_hash_lock); |
1195 | inode = find_inode_fast(sb, head, ino); | |
1196 | spin_unlock(&inode_hash_lock); | |
1da177e4 | 1197 | |
1da177e4 | 1198 | if (inode) |
0b2d0724 CH |
1199 | wait_on_inode(inode); |
1200 | return inode; | |
1da177e4 | 1201 | } |
0b2d0724 | 1202 | EXPORT_SYMBOL(ilookup); |
1da177e4 | 1203 | |
261bca86 AV |
1204 | int insert_inode_locked(struct inode *inode) |
1205 | { | |
1206 | struct super_block *sb = inode->i_sb; | |
1207 | ino_t ino = inode->i_ino; | |
1208 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
261bca86 | 1209 | |
261bca86 | 1210 | while (1) { |
72a43d63 AV |
1211 | struct hlist_node *node; |
1212 | struct inode *old = NULL; | |
67a23c49 | 1213 | spin_lock(&inode_hash_lock); |
72a43d63 AV |
1214 | hlist_for_each_entry(old, node, head, i_hash) { |
1215 | if (old->i_ino != ino) | |
1216 | continue; | |
1217 | if (old->i_sb != sb) | |
1218 | continue; | |
250df6ed DC |
1219 | spin_lock(&old->i_lock); |
1220 | if (old->i_state & (I_FREEING|I_WILL_FREE)) { | |
1221 | spin_unlock(&old->i_lock); | |
72a43d63 | 1222 | continue; |
250df6ed | 1223 | } |
72a43d63 AV |
1224 | break; |
1225 | } | |
1226 | if (likely(!node)) { | |
250df6ed DC |
1227 | spin_lock(&inode->i_lock); |
1228 | inode->i_state |= I_NEW; | |
261bca86 | 1229 | hlist_add_head(&inode->i_hash, head); |
250df6ed | 1230 | spin_unlock(&inode->i_lock); |
67a23c49 | 1231 | spin_unlock(&inode_hash_lock); |
261bca86 AV |
1232 | return 0; |
1233 | } | |
1234 | __iget(old); | |
250df6ed | 1235 | spin_unlock(&old->i_lock); |
67a23c49 | 1236 | spin_unlock(&inode_hash_lock); |
261bca86 | 1237 | wait_on_inode(old); |
1d3382cb | 1238 | if (unlikely(!inode_unhashed(old))) { |
261bca86 AV |
1239 | iput(old); |
1240 | return -EBUSY; | |
1241 | } | |
1242 | iput(old); | |
1243 | } | |
1244 | } | |
261bca86 AV |
1245 | EXPORT_SYMBOL(insert_inode_locked); |
1246 | ||
1247 | int insert_inode_locked4(struct inode *inode, unsigned long hashval, | |
1248 | int (*test)(struct inode *, void *), void *data) | |
1249 | { | |
1250 | struct super_block *sb = inode->i_sb; | |
1251 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
261bca86 | 1252 | |
261bca86 | 1253 | while (1) { |
72a43d63 AV |
1254 | struct hlist_node *node; |
1255 | struct inode *old = NULL; | |
1256 | ||
67a23c49 | 1257 | spin_lock(&inode_hash_lock); |
72a43d63 AV |
1258 | hlist_for_each_entry(old, node, head, i_hash) { |
1259 | if (old->i_sb != sb) | |
1260 | continue; | |
1261 | if (!test(old, data)) | |
1262 | continue; | |
250df6ed DC |
1263 | spin_lock(&old->i_lock); |
1264 | if (old->i_state & (I_FREEING|I_WILL_FREE)) { | |
1265 | spin_unlock(&old->i_lock); | |
72a43d63 | 1266 | continue; |
250df6ed | 1267 | } |
72a43d63 AV |
1268 | break; |
1269 | } | |
1270 | if (likely(!node)) { | |
250df6ed DC |
1271 | spin_lock(&inode->i_lock); |
1272 | inode->i_state |= I_NEW; | |
261bca86 | 1273 | hlist_add_head(&inode->i_hash, head); |
250df6ed | 1274 | spin_unlock(&inode->i_lock); |
67a23c49 | 1275 | spin_unlock(&inode_hash_lock); |
261bca86 AV |
1276 | return 0; |
1277 | } | |
1278 | __iget(old); | |
250df6ed | 1279 | spin_unlock(&old->i_lock); |
67a23c49 | 1280 | spin_unlock(&inode_hash_lock); |
261bca86 | 1281 | wait_on_inode(old); |
1d3382cb | 1282 | if (unlikely(!inode_unhashed(old))) { |
261bca86 AV |
1283 | iput(old); |
1284 | return -EBUSY; | |
1285 | } | |
1286 | iput(old); | |
1287 | } | |
1288 | } | |
261bca86 AV |
1289 | EXPORT_SYMBOL(insert_inode_locked4); |
1290 | ||
1da177e4 | 1291 | |
45321ac5 AV |
1292 | int generic_delete_inode(struct inode *inode) |
1293 | { | |
1294 | return 1; | |
1295 | } | |
1296 | EXPORT_SYMBOL(generic_delete_inode); | |
1297 | ||
1da177e4 | 1298 | /* |
45321ac5 AV |
1299 | * Normal UNIX filesystem behaviour: delete the |
1300 | * inode when the usage count drops to zero, and | |
1301 | * i_nlink is zero. | |
1da177e4 | 1302 | */ |
45321ac5 | 1303 | int generic_drop_inode(struct inode *inode) |
1da177e4 | 1304 | { |
1d3382cb | 1305 | return !inode->i_nlink || inode_unhashed(inode); |
1da177e4 | 1306 | } |
45321ac5 | 1307 | EXPORT_SYMBOL_GPL(generic_drop_inode); |
1da177e4 | 1308 | |
45321ac5 AV |
1309 | /* |
1310 | * Called when we're dropping the last reference | |
1311 | * to an inode. | |
22fe4042 | 1312 | * |
45321ac5 AV |
1313 | * Call the FS "drop_inode()" function, defaulting to |
1314 | * the legacy UNIX filesystem behaviour. If it tells | |
1315 | * us to evict inode, do so. Otherwise, retain inode | |
1316 | * in cache if fs is alive, sync and evict if fs is | |
1317 | * shutting down. | |
22fe4042 | 1318 | */ |
45321ac5 | 1319 | static void iput_final(struct inode *inode) |
1da177e4 LT |
1320 | { |
1321 | struct super_block *sb = inode->i_sb; | |
45321ac5 AV |
1322 | const struct super_operations *op = inode->i_sb->s_op; |
1323 | int drop; | |
1324 | ||
250df6ed DC |
1325 | WARN_ON(inode->i_state & I_NEW); |
1326 | ||
45321ac5 AV |
1327 | if (op && op->drop_inode) |
1328 | drop = op->drop_inode(inode); | |
1329 | else | |
1330 | drop = generic_drop_inode(inode); | |
1da177e4 | 1331 | |
b2b2af8e DC |
1332 | if (!drop && (sb->s_flags & MS_ACTIVE)) { |
1333 | inode->i_state |= I_REFERENCED; | |
1334 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) | |
1335 | inode_lru_list_add(inode); | |
1336 | spin_unlock(&inode->i_lock); | |
b2b2af8e DC |
1337 | return; |
1338 | } | |
1339 | ||
45321ac5 | 1340 | if (!drop) { |
991114c6 | 1341 | inode->i_state |= I_WILL_FREE; |
250df6ed | 1342 | spin_unlock(&inode->i_lock); |
1da177e4 | 1343 | write_inode_now(inode, 1); |
250df6ed | 1344 | spin_lock(&inode->i_lock); |
7ef0d737 | 1345 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1346 | inode->i_state &= ~I_WILL_FREE; |
1da177e4 | 1347 | } |
7ccf19a8 | 1348 | |
991114c6 | 1349 | inode->i_state |= I_FREEING; |
9e38d86f | 1350 | inode_lru_list_del(inode); |
b2b2af8e | 1351 | spin_unlock(&inode->i_lock); |
b2b2af8e | 1352 | |
644da596 | 1353 | evict(inode); |
1da177e4 LT |
1354 | } |
1355 | ||
1da177e4 | 1356 | /** |
6b3304b5 | 1357 | * iput - put an inode |
1da177e4 LT |
1358 | * @inode: inode to put |
1359 | * | |
1360 | * Puts an inode, dropping its usage count. If the inode use count hits | |
1361 | * zero, the inode is then freed and may also be destroyed. | |
1362 | * | |
1363 | * Consequently, iput() can sleep. | |
1364 | */ | |
1365 | void iput(struct inode *inode) | |
1366 | { | |
1367 | if (inode) { | |
a4ffdde6 | 1368 | BUG_ON(inode->i_state & I_CLEAR); |
1da177e4 | 1369 | |
f283c86a | 1370 | if (atomic_dec_and_lock(&inode->i_count, &inode->i_lock)) |
1da177e4 LT |
1371 | iput_final(inode); |
1372 | } | |
1373 | } | |
1da177e4 LT |
1374 | EXPORT_SYMBOL(iput); |
1375 | ||
1376 | /** | |
1377 | * bmap - find a block number in a file | |
1378 | * @inode: inode of file | |
1379 | * @block: block to find | |
1380 | * | |
1381 | * Returns the block number on the device holding the inode that | |
1382 | * is the disk block number for the block of the file requested. | |
1383 | * That is, asked for block 4 of inode 1 the function will return the | |
6b3304b5 | 1384 | * disk block relative to the disk start that holds that block of the |
1da177e4 LT |
1385 | * file. |
1386 | */ | |
6b3304b5 | 1387 | sector_t bmap(struct inode *inode, sector_t block) |
1da177e4 LT |
1388 | { |
1389 | sector_t res = 0; | |
1390 | if (inode->i_mapping->a_ops->bmap) | |
1391 | res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); | |
1392 | return res; | |
1393 | } | |
1da177e4 LT |
1394 | EXPORT_SYMBOL(bmap); |
1395 | ||
11ff6f05 MG |
1396 | /* |
1397 | * With relative atime, only update atime if the previous atime is | |
1398 | * earlier than either the ctime or mtime or if at least a day has | |
1399 | * passed since the last atime update. | |
1400 | */ | |
1401 | static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, | |
1402 | struct timespec now) | |
1403 | { | |
1404 | ||
1405 | if (!(mnt->mnt_flags & MNT_RELATIME)) | |
1406 | return 1; | |
1407 | /* | |
1408 | * Is mtime younger than atime? If yes, update atime: | |
1409 | */ | |
1410 | if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0) | |
1411 | return 1; | |
1412 | /* | |
1413 | * Is ctime younger than atime? If yes, update atime: | |
1414 | */ | |
1415 | if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0) | |
1416 | return 1; | |
1417 | ||
1418 | /* | |
1419 | * Is the previous atime value older than a day? If yes, | |
1420 | * update atime: | |
1421 | */ | |
1422 | if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60) | |
1423 | return 1; | |
1424 | /* | |
1425 | * Good, we can skip the atime update: | |
1426 | */ | |
1427 | return 0; | |
1428 | } | |
1429 | ||
1da177e4 | 1430 | /** |
869243a0 CH |
1431 | * touch_atime - update the access time |
1432 | * @mnt: mount the inode is accessed on | |
7045f37b | 1433 | * @dentry: dentry accessed |
1da177e4 LT |
1434 | * |
1435 | * Update the accessed time on an inode and mark it for writeback. | |
1436 | * This function automatically handles read only file systems and media, | |
1437 | * as well as the "noatime" flag and inode specific "noatime" markers. | |
1438 | */ | |
869243a0 | 1439 | void touch_atime(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4 | 1440 | { |
869243a0 | 1441 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
1442 | struct timespec now; |
1443 | ||
cdb70f3f | 1444 | if (inode->i_flags & S_NOATIME) |
b12536c2 | 1445 | return; |
37756ced | 1446 | if (IS_NOATIME(inode)) |
b12536c2 | 1447 | return; |
b2276138 | 1448 | if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1449 | return; |
47ae32d6 | 1450 | |
cdb70f3f | 1451 | if (mnt->mnt_flags & MNT_NOATIME) |
b12536c2 | 1452 | return; |
cdb70f3f | 1453 | if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1454 | return; |
1da177e4 LT |
1455 | |
1456 | now = current_fs_time(inode->i_sb); | |
11ff6f05 MG |
1457 | |
1458 | if (!relatime_need_update(mnt, inode, now)) | |
b12536c2 | 1459 | return; |
11ff6f05 | 1460 | |
47ae32d6 | 1461 | if (timespec_equal(&inode->i_atime, &now)) |
b12536c2 AK |
1462 | return; |
1463 | ||
1464 | if (mnt_want_write(mnt)) | |
1465 | return; | |
47ae32d6 VH |
1466 | |
1467 | inode->i_atime = now; | |
1468 | mark_inode_dirty_sync(inode); | |
cdb70f3f | 1469 | mnt_drop_write(mnt); |
1da177e4 | 1470 | } |
869243a0 | 1471 | EXPORT_SYMBOL(touch_atime); |
1da177e4 LT |
1472 | |
1473 | /** | |
870f4817 CH |
1474 | * file_update_time - update mtime and ctime time |
1475 | * @file: file accessed | |
1da177e4 | 1476 | * |
870f4817 CH |
1477 | * Update the mtime and ctime members of an inode and mark the inode |
1478 | * for writeback. Note that this function is meant exclusively for | |
1479 | * usage in the file write path of filesystems, and filesystems may | |
1480 | * choose to explicitly ignore update via this function with the | |
2eadfc0e | 1481 | * S_NOCMTIME inode flag, e.g. for network filesystem where these |
870f4817 | 1482 | * timestamps are handled by the server. |
1da177e4 LT |
1483 | */ |
1484 | ||
870f4817 | 1485 | void file_update_time(struct file *file) |
1da177e4 | 1486 | { |
0f7fc9e4 | 1487 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 | 1488 | struct timespec now; |
ce06e0b2 | 1489 | enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0; |
1da177e4 | 1490 | |
ce06e0b2 | 1491 | /* First try to exhaust all avenues to not sync */ |
1da177e4 LT |
1492 | if (IS_NOCMTIME(inode)) |
1493 | return; | |
20ddee2c | 1494 | |
1da177e4 | 1495 | now = current_fs_time(inode->i_sb); |
ce06e0b2 AK |
1496 | if (!timespec_equal(&inode->i_mtime, &now)) |
1497 | sync_it = S_MTIME; | |
1da177e4 | 1498 | |
ce06e0b2 AK |
1499 | if (!timespec_equal(&inode->i_ctime, &now)) |
1500 | sync_it |= S_CTIME; | |
870f4817 | 1501 | |
ce06e0b2 AK |
1502 | if (IS_I_VERSION(inode)) |
1503 | sync_it |= S_VERSION; | |
7a224228 | 1504 | |
ce06e0b2 AK |
1505 | if (!sync_it) |
1506 | return; | |
1507 | ||
1508 | /* Finally allowed to write? Takes lock. */ | |
1509 | if (mnt_want_write_file(file)) | |
1510 | return; | |
1511 | ||
1512 | /* Only change inode inside the lock region */ | |
1513 | if (sync_it & S_VERSION) | |
1514 | inode_inc_iversion(inode); | |
1515 | if (sync_it & S_CTIME) | |
1516 | inode->i_ctime = now; | |
1517 | if (sync_it & S_MTIME) | |
1518 | inode->i_mtime = now; | |
1519 | mark_inode_dirty_sync(inode); | |
20ddee2c | 1520 | mnt_drop_write(file->f_path.mnt); |
1da177e4 | 1521 | } |
870f4817 | 1522 | EXPORT_SYMBOL(file_update_time); |
1da177e4 LT |
1523 | |
1524 | int inode_needs_sync(struct inode *inode) | |
1525 | { | |
1526 | if (IS_SYNC(inode)) | |
1527 | return 1; | |
1528 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) | |
1529 | return 1; | |
1530 | return 0; | |
1531 | } | |
1da177e4 LT |
1532 | EXPORT_SYMBOL(inode_needs_sync); |
1533 | ||
1da177e4 LT |
1534 | int inode_wait(void *word) |
1535 | { | |
1536 | schedule(); | |
1537 | return 0; | |
1538 | } | |
d44dab8d | 1539 | EXPORT_SYMBOL(inode_wait); |
1da177e4 LT |
1540 | |
1541 | /* | |
168a9fd6 MS |
1542 | * If we try to find an inode in the inode hash while it is being |
1543 | * deleted, we have to wait until the filesystem completes its | |
1544 | * deletion before reporting that it isn't found. This function waits | |
1545 | * until the deletion _might_ have completed. Callers are responsible | |
1546 | * to recheck inode state. | |
1547 | * | |
eaff8079 | 1548 | * It doesn't matter if I_NEW is not set initially, a call to |
250df6ed DC |
1549 | * wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list |
1550 | * will DTRT. | |
1da177e4 LT |
1551 | */ |
1552 | static void __wait_on_freeing_inode(struct inode *inode) | |
1553 | { | |
1554 | wait_queue_head_t *wq; | |
eaff8079 CH |
1555 | DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); |
1556 | wq = bit_waitqueue(&inode->i_state, __I_NEW); | |
1da177e4 | 1557 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); |
250df6ed | 1558 | spin_unlock(&inode->i_lock); |
67a23c49 | 1559 | spin_unlock(&inode_hash_lock); |
1da177e4 LT |
1560 | schedule(); |
1561 | finish_wait(wq, &wait.wait); | |
67a23c49 | 1562 | spin_lock(&inode_hash_lock); |
1da177e4 LT |
1563 | } |
1564 | ||
1da177e4 LT |
1565 | static __initdata unsigned long ihash_entries; |
1566 | static int __init set_ihash_entries(char *str) | |
1567 | { | |
1568 | if (!str) | |
1569 | return 0; | |
1570 | ihash_entries = simple_strtoul(str, &str, 0); | |
1571 | return 1; | |
1572 | } | |
1573 | __setup("ihash_entries=", set_ihash_entries); | |
1574 | ||
1575 | /* | |
1576 | * Initialize the waitqueues and inode hash table. | |
1577 | */ | |
1578 | void __init inode_init_early(void) | |
1579 | { | |
1580 | int loop; | |
1581 | ||
1582 | /* If hashes are distributed across NUMA nodes, defer | |
1583 | * hash allocation until vmalloc space is available. | |
1584 | */ | |
1585 | if (hashdist) | |
1586 | return; | |
1587 | ||
1588 | inode_hashtable = | |
1589 | alloc_large_system_hash("Inode-cache", | |
1590 | sizeof(struct hlist_head), | |
1591 | ihash_entries, | |
1592 | 14, | |
1593 | HASH_EARLY, | |
1594 | &i_hash_shift, | |
1595 | &i_hash_mask, | |
1596 | 0); | |
1597 | ||
1598 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1599 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1600 | } | |
1601 | ||
74bf17cf | 1602 | void __init inode_init(void) |
1da177e4 LT |
1603 | { |
1604 | int loop; | |
1605 | ||
1606 | /* inode slab cache */ | |
b0196009 PJ |
1607 | inode_cachep = kmem_cache_create("inode_cache", |
1608 | sizeof(struct inode), | |
1609 | 0, | |
1610 | (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| | |
1611 | SLAB_MEM_SPREAD), | |
20c2df83 | 1612 | init_once); |
8e1f936b | 1613 | register_shrinker(&icache_shrinker); |
1da177e4 LT |
1614 | |
1615 | /* Hash may have been set up in inode_init_early */ | |
1616 | if (!hashdist) | |
1617 | return; | |
1618 | ||
1619 | inode_hashtable = | |
1620 | alloc_large_system_hash("Inode-cache", | |
1621 | sizeof(struct hlist_head), | |
1622 | ihash_entries, | |
1623 | 14, | |
1624 | 0, | |
1625 | &i_hash_shift, | |
1626 | &i_hash_mask, | |
1627 | 0); | |
1628 | ||
1629 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1630 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1631 | } | |
1632 | ||
1633 | void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) | |
1634 | { | |
1635 | inode->i_mode = mode; | |
1636 | if (S_ISCHR(mode)) { | |
1637 | inode->i_fop = &def_chr_fops; | |
1638 | inode->i_rdev = rdev; | |
1639 | } else if (S_ISBLK(mode)) { | |
1640 | inode->i_fop = &def_blk_fops; | |
1641 | inode->i_rdev = rdev; | |
1642 | } else if (S_ISFIFO(mode)) | |
1643 | inode->i_fop = &def_fifo_fops; | |
1644 | else if (S_ISSOCK(mode)) | |
1645 | inode->i_fop = &bad_sock_fops; | |
1646 | else | |
af0d9ae8 MK |
1647 | printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for" |
1648 | " inode %s:%lu\n", mode, inode->i_sb->s_id, | |
1649 | inode->i_ino); | |
1da177e4 LT |
1650 | } |
1651 | EXPORT_SYMBOL(init_special_inode); | |
a1bd120d DM |
1652 | |
1653 | /** | |
eaae668d | 1654 | * inode_init_owner - Init uid,gid,mode for new inode according to posix standards |
a1bd120d DM |
1655 | * @inode: New inode |
1656 | * @dir: Directory inode | |
1657 | * @mode: mode of the new inode | |
1658 | */ | |
1659 | void inode_init_owner(struct inode *inode, const struct inode *dir, | |
1660 | mode_t mode) | |
1661 | { | |
1662 | inode->i_uid = current_fsuid(); | |
1663 | if (dir && dir->i_mode & S_ISGID) { | |
1664 | inode->i_gid = dir->i_gid; | |
1665 | if (S_ISDIR(mode)) | |
1666 | mode |= S_ISGID; | |
1667 | } else | |
1668 | inode->i_gid = current_fsgid(); | |
1669 | inode->i_mode = mode; | |
1670 | } | |
1671 | EXPORT_SYMBOL(inode_init_owner); | |
e795b717 | 1672 | |
2e149670 SH |
1673 | /** |
1674 | * inode_owner_or_capable - check current task permissions to inode | |
1675 | * @inode: inode being checked | |
1676 | * | |
1677 | * Return true if current either has CAP_FOWNER to the inode, or | |
1678 | * owns the file. | |
e795b717 | 1679 | */ |
2e149670 | 1680 | bool inode_owner_or_capable(const struct inode *inode) |
e795b717 SH |
1681 | { |
1682 | struct user_namespace *ns = inode_userns(inode); | |
1683 | ||
1684 | if (current_user_ns() == ns && current_fsuid() == inode->i_uid) | |
1685 | return true; | |
1686 | if (ns_capable(ns, CAP_FOWNER)) | |
1687 | return true; | |
1688 | return false; | |
1689 | } | |
2e149670 | 1690 | EXPORT_SYMBOL(inode_owner_or_capable); |