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Commit | Line | Data |
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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> | |
11 | #include <linux/quotaops.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/writeback.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/backing-dev.h> | |
16 | #include <linux/wait.h> | |
88e0fbc4 | 17 | #include <linux/rwsem.h> |
1da177e4 LT |
18 | #include <linux/hash.h> |
19 | #include <linux/swap.h> | |
20 | #include <linux/security.h> | |
6146f0d5 | 21 | #include <linux/ima.h> |
1da177e4 LT |
22 | #include <linux/pagemap.h> |
23 | #include <linux/cdev.h> | |
24 | #include <linux/bootmem.h> | |
0eeca283 | 25 | #include <linux/inotify.h> |
3be25f49 | 26 | #include <linux/fsnotify.h> |
fc33a7bb | 27 | #include <linux/mount.h> |
efaee192 | 28 | #include <linux/async.h> |
f19d4a8f | 29 | #include <linux/posix_acl.h> |
1da177e4 LT |
30 | |
31 | /* | |
32 | * This is needed for the following functions: | |
33 | * - inode_has_buffers | |
34 | * - invalidate_inode_buffers | |
1da177e4 LT |
35 | * - invalidate_bdev |
36 | * | |
37 | * FIXME: remove all knowledge of the buffer layer from this file | |
38 | */ | |
39 | #include <linux/buffer_head.h> | |
40 | ||
41 | /* | |
42 | * New inode.c implementation. | |
43 | * | |
44 | * This implementation has the basic premise of trying | |
45 | * to be extremely low-overhead and SMP-safe, yet be | |
46 | * simple enough to be "obviously correct". | |
47 | * | |
48 | * Famous last words. | |
49 | */ | |
50 | ||
51 | /* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */ | |
52 | ||
53 | /* #define INODE_PARANOIA 1 */ | |
54 | /* #define INODE_DEBUG 1 */ | |
55 | ||
56 | /* | |
57 | * Inode lookup is no longer as critical as it used to be: | |
58 | * most of the lookups are going to be through the dcache. | |
59 | */ | |
60 | #define I_HASHBITS i_hash_shift | |
61 | #define I_HASHMASK i_hash_mask | |
62 | ||
fa3536cc ED |
63 | static unsigned int i_hash_mask __read_mostly; |
64 | static unsigned int i_hash_shift __read_mostly; | |
1da177e4 LT |
65 | |
66 | /* | |
67 | * Each inode can be on two separate lists. One is | |
68 | * the hash list of the inode, used for lookups. The | |
69 | * other linked list is the "type" list: | |
70 | * "in_use" - valid inode, i_count > 0, i_nlink > 0 | |
71 | * "dirty" - as "in_use" but also dirty | |
72 | * "unused" - valid inode, i_count = 0 | |
73 | * | |
74 | * A "dirty" list is maintained for each super block, | |
75 | * allowing for low-overhead inode sync() operations. | |
76 | */ | |
77 | ||
78 | LIST_HEAD(inode_in_use); | |
79 | LIST_HEAD(inode_unused); | |
fa3536cc | 80 | static struct hlist_head *inode_hashtable __read_mostly; |
1da177e4 LT |
81 | |
82 | /* | |
83 | * A simple spinlock to protect the list manipulations. | |
84 | * | |
85 | * NOTE! You also have to own the lock if you change | |
86 | * the i_state of an inode while it is in use.. | |
87 | */ | |
88 | DEFINE_SPINLOCK(inode_lock); | |
89 | ||
90 | /* | |
88e0fbc4 | 91 | * iprune_sem provides exclusion between the kswapd or try_to_free_pages |
1da177e4 LT |
92 | * icache shrinking path, and the umount path. Without this exclusion, |
93 | * by the time prune_icache calls iput for the inode whose pages it has | |
94 | * been invalidating, or by the time it calls clear_inode & destroy_inode | |
95 | * from its final dispose_list, the struct super_block they refer to | |
96 | * (for inode->i_sb->s_op) may already have been freed and reused. | |
88e0fbc4 NP |
97 | * |
98 | * We make this an rwsem because the fastpath is icache shrinking. In | |
99 | * some cases a filesystem may be doing a significant amount of work in | |
100 | * its inode reclaim code, so this should improve parallelism. | |
1da177e4 | 101 | */ |
88e0fbc4 | 102 | static DECLARE_RWSEM(iprune_sem); |
1da177e4 LT |
103 | |
104 | /* | |
105 | * Statistics gathering.. | |
106 | */ | |
107 | struct inodes_stat_t inodes_stat; | |
108 | ||
6b3304b5 | 109 | static struct kmem_cache *inode_cachep __read_mostly; |
1da177e4 | 110 | |
1c0eeaf5 JE |
111 | static void wake_up_inode(struct inode *inode) |
112 | { | |
113 | /* | |
114 | * Prevent speculative execution through spin_unlock(&inode_lock); | |
115 | */ | |
116 | smp_mb(); | |
117 | wake_up_bit(&inode->i_state, __I_LOCK); | |
118 | } | |
119 | ||
2cb1599f DC |
120 | /** |
121 | * inode_init_always - perform inode structure intialisation | |
0bc02f3f RD |
122 | * @sb: superblock inode belongs to |
123 | * @inode: inode to initialise | |
2cb1599f DC |
124 | * |
125 | * These are initializations that need to be done on every inode | |
126 | * allocation as the fields are not initialised by slab allocation. | |
127 | */ | |
54e34621 | 128 | int inode_init_always(struct super_block *sb, struct inode *inode) |
1da177e4 | 129 | { |
f5e54d6e | 130 | static const struct address_space_operations empty_aops; |
6e1d5dcc | 131 | static const struct inode_operations empty_iops; |
99ac48f5 | 132 | static const struct file_operations empty_fops; |
6b3304b5 | 133 | struct address_space *const mapping = &inode->i_data; |
2cb1599f DC |
134 | |
135 | inode->i_sb = sb; | |
136 | inode->i_blkbits = sb->s_blocksize_bits; | |
137 | inode->i_flags = 0; | |
138 | atomic_set(&inode->i_count, 1); | |
139 | inode->i_op = &empty_iops; | |
140 | inode->i_fop = &empty_fops; | |
141 | inode->i_nlink = 1; | |
56ff5efa AV |
142 | inode->i_uid = 0; |
143 | inode->i_gid = 0; | |
2cb1599f DC |
144 | atomic_set(&inode->i_writecount, 0); |
145 | inode->i_size = 0; | |
146 | inode->i_blocks = 0; | |
147 | inode->i_bytes = 0; | |
148 | inode->i_generation = 0; | |
1da177e4 | 149 | #ifdef CONFIG_QUOTA |
2cb1599f | 150 | memset(&inode->i_dquot, 0, sizeof(inode->i_dquot)); |
1da177e4 | 151 | #endif |
2cb1599f DC |
152 | inode->i_pipe = NULL; |
153 | inode->i_bdev = NULL; | |
154 | inode->i_cdev = NULL; | |
155 | inode->i_rdev = 0; | |
156 | inode->dirtied_when = 0; | |
6146f0d5 MZ |
157 | |
158 | if (security_inode_alloc(inode)) | |
54e34621 | 159 | goto out; |
6146f0d5 MZ |
160 | |
161 | /* allocate and initialize an i_integrity */ | |
162 | if (ima_inode_alloc(inode)) | |
163 | goto out_free_security; | |
2cb1599f DC |
164 | |
165 | spin_lock_init(&inode->i_lock); | |
166 | lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key); | |
167 | ||
168 | mutex_init(&inode->i_mutex); | |
169 | lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key); | |
170 | ||
171 | init_rwsem(&inode->i_alloc_sem); | |
172 | lockdep_set_class(&inode->i_alloc_sem, &sb->s_type->i_alloc_sem_key); | |
173 | ||
174 | mapping->a_ops = &empty_aops; | |
175 | mapping->host = inode; | |
176 | mapping->flags = 0; | |
3c1d4378 | 177 | mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE); |
2cb1599f DC |
178 | mapping->assoc_mapping = NULL; |
179 | mapping->backing_dev_info = &default_backing_dev_info; | |
180 | mapping->writeback_index = 0; | |
181 | ||
182 | /* | |
183 | * If the block_device provides a backing_dev_info for client | |
184 | * inodes then use that. Otherwise the inode share the bdev's | |
185 | * backing_dev_info. | |
186 | */ | |
187 | if (sb->s_bdev) { | |
188 | struct backing_dev_info *bdi; | |
189 | ||
2c96ce9f | 190 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; |
2cb1599f DC |
191 | mapping->backing_dev_info = bdi; |
192 | } | |
193 | inode->i_private = NULL; | |
194 | inode->i_mapping = mapping; | |
f19d4a8f AV |
195 | #ifdef CONFIG_FS_POSIX_ACL |
196 | inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; | |
197 | #endif | |
2cb1599f | 198 | |
3be25f49 EP |
199 | #ifdef CONFIG_FSNOTIFY |
200 | inode->i_fsnotify_mask = 0; | |
201 | #endif | |
202 | ||
54e34621 | 203 | return 0; |
6146f0d5 MZ |
204 | |
205 | out_free_security: | |
206 | security_inode_free(inode); | |
54e34621 CH |
207 | out: |
208 | return -ENOMEM; | |
1da177e4 | 209 | } |
2cb1599f DC |
210 | EXPORT_SYMBOL(inode_init_always); |
211 | ||
212 | static struct inode *alloc_inode(struct super_block *sb) | |
213 | { | |
214 | struct inode *inode; | |
215 | ||
216 | if (sb->s_op->alloc_inode) | |
217 | inode = sb->s_op->alloc_inode(sb); | |
218 | else | |
219 | inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL); | |
220 | ||
54e34621 CH |
221 | if (!inode) |
222 | return NULL; | |
223 | ||
224 | if (unlikely(inode_init_always(sb, inode))) { | |
225 | if (inode->i_sb->s_op->destroy_inode) | |
226 | inode->i_sb->s_op->destroy_inode(inode); | |
227 | else | |
228 | kmem_cache_free(inode_cachep, inode); | |
229 | return NULL; | |
230 | } | |
231 | ||
232 | return inode; | |
2cb1599f | 233 | } |
1da177e4 | 234 | |
2e00c97e | 235 | void __destroy_inode(struct inode *inode) |
1da177e4 | 236 | { |
b7542f8c | 237 | BUG_ON(inode_has_buffers(inode)); |
f07502da | 238 | ima_inode_free(inode); |
1da177e4 | 239 | security_inode_free(inode); |
3be25f49 | 240 | fsnotify_inode_delete(inode); |
f19d4a8f AV |
241 | #ifdef CONFIG_FS_POSIX_ACL |
242 | if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED) | |
243 | posix_acl_release(inode->i_acl); | |
244 | if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) | |
245 | posix_acl_release(inode->i_default_acl); | |
246 | #endif | |
2e00c97e CH |
247 | } |
248 | EXPORT_SYMBOL(__destroy_inode); | |
249 | ||
250 | void destroy_inode(struct inode *inode) | |
251 | { | |
252 | __destroy_inode(inode); | |
1da177e4 LT |
253 | if (inode->i_sb->s_op->destroy_inode) |
254 | inode->i_sb->s_op->destroy_inode(inode); | |
255 | else | |
256 | kmem_cache_free(inode_cachep, (inode)); | |
257 | } | |
1da177e4 LT |
258 | |
259 | /* | |
260 | * These are initializations that only need to be done | |
261 | * once, because the fields are idempotent across use | |
262 | * of the inode, so let the slab aware of that. | |
263 | */ | |
264 | void inode_init_once(struct inode *inode) | |
265 | { | |
266 | memset(inode, 0, sizeof(*inode)); | |
267 | INIT_HLIST_NODE(&inode->i_hash); | |
268 | INIT_LIST_HEAD(&inode->i_dentry); | |
269 | INIT_LIST_HEAD(&inode->i_devices); | |
1da177e4 | 270 | INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); |
19fd6231 | 271 | spin_lock_init(&inode->i_data.tree_lock); |
1da177e4 LT |
272 | spin_lock_init(&inode->i_data.i_mmap_lock); |
273 | INIT_LIST_HEAD(&inode->i_data.private_list); | |
274 | spin_lock_init(&inode->i_data.private_lock); | |
275 | INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap); | |
276 | INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); | |
1da177e4 | 277 | i_size_ordered_init(inode); |
0eeca283 RL |
278 | #ifdef CONFIG_INOTIFY |
279 | INIT_LIST_HEAD(&inode->inotify_watches); | |
d4f9af9d | 280 | mutex_init(&inode->inotify_mutex); |
0eeca283 | 281 | #endif |
3be25f49 EP |
282 | #ifdef CONFIG_FSNOTIFY |
283 | INIT_HLIST_HEAD(&inode->i_fsnotify_mark_entries); | |
284 | #endif | |
1da177e4 | 285 | } |
1da177e4 LT |
286 | EXPORT_SYMBOL(inode_init_once); |
287 | ||
51cc5068 | 288 | static void init_once(void *foo) |
1da177e4 | 289 | { |
6b3304b5 | 290 | struct inode *inode = (struct inode *) foo; |
1da177e4 | 291 | |
a35afb83 | 292 | inode_init_once(inode); |
1da177e4 LT |
293 | } |
294 | ||
295 | /* | |
296 | * inode_lock must be held | |
297 | */ | |
6b3304b5 | 298 | void __iget(struct inode *inode) |
1da177e4 LT |
299 | { |
300 | if (atomic_read(&inode->i_count)) { | |
301 | atomic_inc(&inode->i_count); | |
302 | return; | |
303 | } | |
304 | atomic_inc(&inode->i_count); | |
1c0eeaf5 | 305 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) |
1da177e4 LT |
306 | list_move(&inode->i_list, &inode_in_use); |
307 | inodes_stat.nr_unused--; | |
308 | } | |
309 | ||
310 | /** | |
311 | * clear_inode - clear an inode | |
312 | * @inode: inode to clear | |
313 | * | |
314 | * This is called by the filesystem to tell us | |
315 | * that the inode is no longer useful. We just | |
316 | * terminate it with extreme prejudice. | |
317 | */ | |
318 | void clear_inode(struct inode *inode) | |
319 | { | |
320 | might_sleep(); | |
321 | invalidate_inode_buffers(inode); | |
6b3304b5 | 322 | |
b7542f8c ES |
323 | BUG_ON(inode->i_data.nrpages); |
324 | BUG_ON(!(inode->i_state & I_FREEING)); | |
325 | BUG_ON(inode->i_state & I_CLEAR); | |
1c0eeaf5 | 326 | inode_sync_wait(inode); |
9e3509e2 | 327 | vfs_dq_drop(inode); |
acb0c854 | 328 | if (inode->i_sb->s_op->clear_inode) |
1da177e4 | 329 | inode->i_sb->s_op->clear_inode(inode); |
eaf796e7 | 330 | if (S_ISBLK(inode->i_mode) && inode->i_bdev) |
1da177e4 | 331 | bd_forget(inode); |
577c4eb0 | 332 | if (S_ISCHR(inode->i_mode) && inode->i_cdev) |
1da177e4 LT |
333 | cd_forget(inode); |
334 | inode->i_state = I_CLEAR; | |
335 | } | |
1da177e4 LT |
336 | EXPORT_SYMBOL(clear_inode); |
337 | ||
338 | /* | |
339 | * dispose_list - dispose of the contents of a local list | |
340 | * @head: the head of the list to free | |
341 | * | |
342 | * Dispose-list gets a local list with local inodes in it, so it doesn't | |
343 | * need to worry about list corruption and SMP locks. | |
344 | */ | |
345 | static void dispose_list(struct list_head *head) | |
346 | { | |
347 | int nr_disposed = 0; | |
348 | ||
349 | while (!list_empty(head)) { | |
350 | struct inode *inode; | |
351 | ||
b5e61818 | 352 | inode = list_first_entry(head, struct inode, i_list); |
1da177e4 LT |
353 | list_del(&inode->i_list); |
354 | ||
355 | if (inode->i_data.nrpages) | |
356 | truncate_inode_pages(&inode->i_data, 0); | |
357 | clear_inode(inode); | |
4120db47 AB |
358 | |
359 | spin_lock(&inode_lock); | |
360 | hlist_del_init(&inode->i_hash); | |
361 | list_del_init(&inode->i_sb_list); | |
362 | spin_unlock(&inode_lock); | |
363 | ||
364 | wake_up_inode(inode); | |
1da177e4 LT |
365 | destroy_inode(inode); |
366 | nr_disposed++; | |
367 | } | |
368 | spin_lock(&inode_lock); | |
369 | inodes_stat.nr_inodes -= nr_disposed; | |
370 | spin_unlock(&inode_lock); | |
371 | } | |
372 | ||
373 | /* | |
374 | * Invalidate all inodes for a device. | |
375 | */ | |
376 | static int invalidate_list(struct list_head *head, struct list_head *dispose) | |
377 | { | |
378 | struct list_head *next; | |
379 | int busy = 0, count = 0; | |
380 | ||
381 | next = head->next; | |
382 | for (;;) { | |
6b3304b5 MK |
383 | struct list_head *tmp = next; |
384 | struct inode *inode; | |
1da177e4 LT |
385 | |
386 | /* | |
387 | * We can reschedule here without worrying about the list's | |
388 | * consistency because the per-sb list of inodes must not | |
88e0fbc4 | 389 | * change during umount anymore, and because iprune_sem keeps |
1da177e4 LT |
390 | * shrink_icache_memory() away. |
391 | */ | |
392 | cond_resched_lock(&inode_lock); | |
393 | ||
394 | next = next->next; | |
395 | if (tmp == head) | |
396 | break; | |
397 | inode = list_entry(tmp, struct inode, i_sb_list); | |
aabb8fdb NP |
398 | if (inode->i_state & I_NEW) |
399 | continue; | |
1da177e4 LT |
400 | invalidate_inode_buffers(inode); |
401 | if (!atomic_read(&inode->i_count)) { | |
1da177e4 | 402 | list_move(&inode->i_list, dispose); |
7ef0d737 | 403 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 LT |
404 | inode->i_state |= I_FREEING; |
405 | count++; | |
406 | continue; | |
407 | } | |
408 | busy = 1; | |
409 | } | |
410 | /* only unused inodes may be cached with i_count zero */ | |
411 | inodes_stat.nr_unused -= count; | |
412 | return busy; | |
413 | } | |
414 | ||
1da177e4 LT |
415 | /** |
416 | * invalidate_inodes - discard the inodes on a device | |
417 | * @sb: superblock | |
418 | * | |
419 | * Discard all of the inodes for a given superblock. If the discard | |
420 | * fails because there are busy inodes then a non zero value is returned. | |
421 | * If the discard is successful all the inodes have been discarded. | |
422 | */ | |
6b3304b5 | 423 | int invalidate_inodes(struct super_block *sb) |
1da177e4 LT |
424 | { |
425 | int busy; | |
426 | LIST_HEAD(throw_away); | |
427 | ||
88e0fbc4 | 428 | down_write(&iprune_sem); |
1da177e4 | 429 | spin_lock(&inode_lock); |
0eeca283 | 430 | inotify_unmount_inodes(&sb->s_inodes); |
164bc619 | 431 | fsnotify_unmount_inodes(&sb->s_inodes); |
1da177e4 LT |
432 | busy = invalidate_list(&sb->s_inodes, &throw_away); |
433 | spin_unlock(&inode_lock); | |
434 | ||
435 | dispose_list(&throw_away); | |
88e0fbc4 | 436 | up_write(&iprune_sem); |
1da177e4 LT |
437 | |
438 | return busy; | |
439 | } | |
1da177e4 | 440 | EXPORT_SYMBOL(invalidate_inodes); |
1da177e4 LT |
441 | |
442 | static int can_unuse(struct inode *inode) | |
443 | { | |
444 | if (inode->i_state) | |
445 | return 0; | |
446 | if (inode_has_buffers(inode)) | |
447 | return 0; | |
448 | if (atomic_read(&inode->i_count)) | |
449 | return 0; | |
450 | if (inode->i_data.nrpages) | |
451 | return 0; | |
452 | return 1; | |
453 | } | |
454 | ||
455 | /* | |
456 | * Scan `goal' inodes on the unused list for freeable ones. They are moved to | |
457 | * a temporary list and then are freed outside inode_lock by dispose_list(). | |
458 | * | |
459 | * Any inodes which are pinned purely because of attached pagecache have their | |
460 | * pagecache removed. We expect the final iput() on that inode to add it to | |
461 | * the front of the inode_unused list. So look for it there and if the | |
462 | * inode is still freeable, proceed. The right inode is found 99.9% of the | |
463 | * time in testing on a 4-way. | |
464 | * | |
465 | * If the inode has metadata buffers attached to mapping->private_list then | |
466 | * try to remove them. | |
467 | */ | |
468 | static void prune_icache(int nr_to_scan) | |
469 | { | |
470 | LIST_HEAD(freeable); | |
471 | int nr_pruned = 0; | |
472 | int nr_scanned; | |
473 | unsigned long reap = 0; | |
474 | ||
88e0fbc4 | 475 | down_read(&iprune_sem); |
1da177e4 LT |
476 | spin_lock(&inode_lock); |
477 | for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { | |
478 | struct inode *inode; | |
479 | ||
480 | if (list_empty(&inode_unused)) | |
481 | break; | |
482 | ||
483 | inode = list_entry(inode_unused.prev, struct inode, i_list); | |
484 | ||
485 | if (inode->i_state || atomic_read(&inode->i_count)) { | |
486 | list_move(&inode->i_list, &inode_unused); | |
487 | continue; | |
488 | } | |
489 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { | |
490 | __iget(inode); | |
491 | spin_unlock(&inode_lock); | |
492 | if (remove_inode_buffers(inode)) | |
fc0ecff6 AM |
493 | reap += invalidate_mapping_pages(&inode->i_data, |
494 | 0, -1); | |
1da177e4 LT |
495 | iput(inode); |
496 | spin_lock(&inode_lock); | |
497 | ||
498 | if (inode != list_entry(inode_unused.next, | |
499 | struct inode, i_list)) | |
500 | continue; /* wrong inode or list_empty */ | |
501 | if (!can_unuse(inode)) | |
502 | continue; | |
503 | } | |
1da177e4 | 504 | list_move(&inode->i_list, &freeable); |
7ef0d737 | 505 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 LT |
506 | inode->i_state |= I_FREEING; |
507 | nr_pruned++; | |
508 | } | |
509 | inodes_stat.nr_unused -= nr_pruned; | |
f8891e5e CL |
510 | if (current_is_kswapd()) |
511 | __count_vm_events(KSWAPD_INODESTEAL, reap); | |
512 | else | |
513 | __count_vm_events(PGINODESTEAL, reap); | |
1da177e4 LT |
514 | spin_unlock(&inode_lock); |
515 | ||
516 | dispose_list(&freeable); | |
88e0fbc4 | 517 | up_read(&iprune_sem); |
1da177e4 LT |
518 | } |
519 | ||
520 | /* | |
521 | * shrink_icache_memory() will attempt to reclaim some unused inodes. Here, | |
522 | * "unused" means that no dentries are referring to the inodes: the files are | |
523 | * not open and the dcache references to those inodes have already been | |
524 | * reclaimed. | |
525 | * | |
526 | * This function is passed the number of inodes to scan, and it returns the | |
527 | * total number of remaining possibly-reclaimable inodes. | |
528 | */ | |
27496a8c | 529 | static int shrink_icache_memory(int nr, gfp_t gfp_mask) |
1da177e4 LT |
530 | { |
531 | if (nr) { | |
532 | /* | |
533 | * Nasty deadlock avoidance. We may hold various FS locks, | |
534 | * and we don't want to recurse into the FS that called us | |
535 | * in clear_inode() and friends.. | |
6b3304b5 | 536 | */ |
1da177e4 LT |
537 | if (!(gfp_mask & __GFP_FS)) |
538 | return -1; | |
539 | prune_icache(nr); | |
540 | } | |
541 | return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure; | |
542 | } | |
543 | ||
8e1f936b RR |
544 | static struct shrinker icache_shrinker = { |
545 | .shrink = shrink_icache_memory, | |
546 | .seeks = DEFAULT_SEEKS, | |
547 | }; | |
548 | ||
1da177e4 LT |
549 | static void __wait_on_freeing_inode(struct inode *inode); |
550 | /* | |
551 | * Called with the inode lock held. | |
552 | * NOTE: we are not increasing the inode-refcount, you must call __iget() | |
553 | * by hand after calling find_inode now! This simplifies iunique and won't | |
554 | * add any additional branch in the common code. | |
555 | */ | |
6b3304b5 MK |
556 | static struct inode *find_inode(struct super_block *sb, |
557 | struct hlist_head *head, | |
558 | int (*test)(struct inode *, void *), | |
559 | void *data) | |
1da177e4 LT |
560 | { |
561 | struct hlist_node *node; | |
6b3304b5 | 562 | struct inode *inode = NULL; |
1da177e4 LT |
563 | |
564 | repeat: | |
c5c8be3c | 565 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
566 | if (inode->i_sb != sb) |
567 | continue; | |
568 | if (!test(inode, data)) | |
569 | continue; | |
991114c6 | 570 | if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { |
1da177e4 LT |
571 | __wait_on_freeing_inode(inode); |
572 | goto repeat; | |
573 | } | |
574 | break; | |
575 | } | |
576 | return node ? inode : NULL; | |
577 | } | |
578 | ||
579 | /* | |
580 | * find_inode_fast is the fast path version of find_inode, see the comment at | |
581 | * iget_locked for details. | |
582 | */ | |
6b3304b5 MK |
583 | static struct inode *find_inode_fast(struct super_block *sb, |
584 | struct hlist_head *head, unsigned long ino) | |
1da177e4 LT |
585 | { |
586 | struct hlist_node *node; | |
6b3304b5 | 587 | struct inode *inode = NULL; |
1da177e4 LT |
588 | |
589 | repeat: | |
c5c8be3c | 590 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
591 | if (inode->i_ino != ino) |
592 | continue; | |
593 | if (inode->i_sb != sb) | |
594 | continue; | |
991114c6 | 595 | if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { |
1da177e4 LT |
596 | __wait_on_freeing_inode(inode); |
597 | goto repeat; | |
598 | } | |
599 | break; | |
600 | } | |
601 | return node ? inode : NULL; | |
602 | } | |
603 | ||
8290c35f DC |
604 | static unsigned long hash(struct super_block *sb, unsigned long hashval) |
605 | { | |
606 | unsigned long tmp; | |
607 | ||
608 | tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / | |
609 | L1_CACHE_BYTES; | |
610 | tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS); | |
611 | return tmp & I_HASHMASK; | |
612 | } | |
613 | ||
614 | static inline void | |
615 | __inode_add_to_lists(struct super_block *sb, struct hlist_head *head, | |
616 | struct inode *inode) | |
617 | { | |
618 | inodes_stat.nr_inodes++; | |
619 | list_add(&inode->i_list, &inode_in_use); | |
620 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
621 | if (head) | |
622 | hlist_add_head(&inode->i_hash, head); | |
623 | } | |
624 | ||
625 | /** | |
626 | * inode_add_to_lists - add a new inode to relevant lists | |
0bc02f3f RD |
627 | * @sb: superblock inode belongs to |
628 | * @inode: inode to mark in use | |
8290c35f DC |
629 | * |
630 | * When an inode is allocated it needs to be accounted for, added to the in use | |
631 | * list, the owning superblock and the inode hash. This needs to be done under | |
632 | * the inode_lock, so export a function to do this rather than the inode lock | |
633 | * itself. We calculate the hash list to add to here so it is all internal | |
634 | * which requires the caller to have already set up the inode number in the | |
635 | * inode to add. | |
636 | */ | |
637 | void inode_add_to_lists(struct super_block *sb, struct inode *inode) | |
638 | { | |
639 | struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino); | |
640 | ||
641 | spin_lock(&inode_lock); | |
642 | __inode_add_to_lists(sb, head, inode); | |
643 | spin_unlock(&inode_lock); | |
644 | } | |
645 | EXPORT_SYMBOL_GPL(inode_add_to_lists); | |
646 | ||
1da177e4 LT |
647 | /** |
648 | * new_inode - obtain an inode | |
649 | * @sb: superblock | |
650 | * | |
769848c0 | 651 | * Allocates a new inode for given superblock. The default gfp_mask |
3c1d4378 | 652 | * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE. |
769848c0 MG |
653 | * If HIGHMEM pages are unsuitable or it is known that pages allocated |
654 | * for the page cache are not reclaimable or migratable, | |
655 | * mapping_set_gfp_mask() must be called with suitable flags on the | |
656 | * newly created inode's mapping | |
657 | * | |
1da177e4 LT |
658 | */ |
659 | struct inode *new_inode(struct super_block *sb) | |
660 | { | |
866b04fc JL |
661 | /* |
662 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
663 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
664 | * here to attempt to avoid that. | |
665 | */ | |
666 | static unsigned int last_ino; | |
6b3304b5 | 667 | struct inode *inode; |
1da177e4 LT |
668 | |
669 | spin_lock_prefetch(&inode_lock); | |
6b3304b5 | 670 | |
1da177e4 LT |
671 | inode = alloc_inode(sb); |
672 | if (inode) { | |
673 | spin_lock(&inode_lock); | |
8290c35f | 674 | __inode_add_to_lists(sb, NULL, inode); |
1da177e4 LT |
675 | inode->i_ino = ++last_ino; |
676 | inode->i_state = 0; | |
677 | spin_unlock(&inode_lock); | |
678 | } | |
679 | return inode; | |
680 | } | |
1da177e4 LT |
681 | EXPORT_SYMBOL(new_inode); |
682 | ||
683 | void unlock_new_inode(struct inode *inode) | |
684 | { | |
14358e6d | 685 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
1e89a5e1 PZ |
686 | if (inode->i_mode & S_IFDIR) { |
687 | struct file_system_type *type = inode->i_sb->s_type; | |
688 | ||
9a7aa12f JK |
689 | /* Set new key only if filesystem hasn't already changed it */ |
690 | if (!lockdep_match_class(&inode->i_mutex, | |
691 | &type->i_mutex_key)) { | |
692 | /* | |
693 | * ensure nobody is actually holding i_mutex | |
694 | */ | |
695 | mutex_destroy(&inode->i_mutex); | |
696 | mutex_init(&inode->i_mutex); | |
697 | lockdep_set_class(&inode->i_mutex, | |
698 | &type->i_mutex_dir_key); | |
699 | } | |
1e89a5e1 | 700 | } |
14358e6d | 701 | #endif |
1da177e4 | 702 | /* |
580be083 JK |
703 | * This is special! We do not need the spinlock when clearing I_LOCK, |
704 | * because we're guaranteed that nobody else tries to do anything about | |
705 | * the state of the inode when it is locked, as we just created it (so | |
706 | * there can be no old holders that haven't tested I_LOCK). | |
707 | * However we must emit the memory barrier so that other CPUs reliably | |
708 | * see the clearing of I_LOCK after the other inode initialisation has | |
709 | * completed. | |
1da177e4 | 710 | */ |
580be083 | 711 | smp_mb(); |
7ef0d737 | 712 | WARN_ON((inode->i_state & (I_LOCK|I_NEW)) != (I_LOCK|I_NEW)); |
1da177e4 LT |
713 | inode->i_state &= ~(I_LOCK|I_NEW); |
714 | wake_up_inode(inode); | |
715 | } | |
1da177e4 LT |
716 | EXPORT_SYMBOL(unlock_new_inode); |
717 | ||
718 | /* | |
719 | * This is called without the inode lock held.. Be careful. | |
720 | * | |
721 | * We no longer cache the sb_flags in i_flags - see fs.h | |
722 | * -- rmk@arm.uk.linux.org | |
723 | */ | |
6b3304b5 MK |
724 | static struct inode *get_new_inode(struct super_block *sb, |
725 | struct hlist_head *head, | |
726 | int (*test)(struct inode *, void *), | |
727 | int (*set)(struct inode *, void *), | |
728 | void *data) | |
1da177e4 | 729 | { |
6b3304b5 | 730 | struct inode *inode; |
1da177e4 LT |
731 | |
732 | inode = alloc_inode(sb); | |
733 | if (inode) { | |
6b3304b5 | 734 | struct inode *old; |
1da177e4 LT |
735 | |
736 | spin_lock(&inode_lock); | |
737 | /* We released the lock, so.. */ | |
738 | old = find_inode(sb, head, test, data); | |
739 | if (!old) { | |
740 | if (set(inode, data)) | |
741 | goto set_failed; | |
742 | ||
8290c35f | 743 | __inode_add_to_lists(sb, head, inode); |
1da177e4 LT |
744 | inode->i_state = I_LOCK|I_NEW; |
745 | spin_unlock(&inode_lock); | |
746 | ||
747 | /* Return the locked inode with I_NEW set, the | |
748 | * caller is responsible for filling in the contents | |
749 | */ | |
750 | return inode; | |
751 | } | |
752 | ||
753 | /* | |
754 | * Uhhuh, somebody else created the same inode under | |
755 | * us. Use the old inode instead of the one we just | |
756 | * allocated. | |
757 | */ | |
758 | __iget(old); | |
759 | spin_unlock(&inode_lock); | |
760 | destroy_inode(inode); | |
761 | inode = old; | |
762 | wait_on_inode(inode); | |
763 | } | |
764 | return inode; | |
765 | ||
766 | set_failed: | |
767 | spin_unlock(&inode_lock); | |
768 | destroy_inode(inode); | |
769 | return NULL; | |
770 | } | |
771 | ||
772 | /* | |
773 | * get_new_inode_fast is the fast path version of get_new_inode, see the | |
774 | * comment at iget_locked for details. | |
775 | */ | |
6b3304b5 MK |
776 | static struct inode *get_new_inode_fast(struct super_block *sb, |
777 | struct hlist_head *head, unsigned long ino) | |
1da177e4 | 778 | { |
6b3304b5 | 779 | struct inode *inode; |
1da177e4 LT |
780 | |
781 | inode = alloc_inode(sb); | |
782 | if (inode) { | |
6b3304b5 | 783 | struct inode *old; |
1da177e4 LT |
784 | |
785 | spin_lock(&inode_lock); | |
786 | /* We released the lock, so.. */ | |
787 | old = find_inode_fast(sb, head, ino); | |
788 | if (!old) { | |
789 | inode->i_ino = ino; | |
8290c35f | 790 | __inode_add_to_lists(sb, head, inode); |
1da177e4 LT |
791 | inode->i_state = I_LOCK|I_NEW; |
792 | spin_unlock(&inode_lock); | |
793 | ||
794 | /* Return the locked inode with I_NEW set, the | |
795 | * caller is responsible for filling in the contents | |
796 | */ | |
797 | return inode; | |
798 | } | |
799 | ||
800 | /* | |
801 | * Uhhuh, somebody else created the same inode under | |
802 | * us. Use the old inode instead of the one we just | |
803 | * allocated. | |
804 | */ | |
805 | __iget(old); | |
806 | spin_unlock(&inode_lock); | |
807 | destroy_inode(inode); | |
808 | inode = old; | |
809 | wait_on_inode(inode); | |
810 | } | |
811 | return inode; | |
812 | } | |
813 | ||
1da177e4 LT |
814 | /** |
815 | * iunique - get a unique inode number | |
816 | * @sb: superblock | |
817 | * @max_reserved: highest reserved inode number | |
818 | * | |
819 | * Obtain an inode number that is unique on the system for a given | |
820 | * superblock. This is used by file systems that have no natural | |
821 | * permanent inode numbering system. An inode number is returned that | |
822 | * is higher than the reserved limit but unique. | |
823 | * | |
824 | * BUGS: | |
825 | * With a large number of inodes live on the file system this function | |
826 | * currently becomes quite slow. | |
827 | */ | |
828 | ino_t iunique(struct super_block *sb, ino_t max_reserved) | |
829 | { | |
866b04fc JL |
830 | /* |
831 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
832 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
833 | * here to attempt to avoid that. | |
834 | */ | |
835 | static unsigned int counter; | |
1da177e4 | 836 | struct inode *inode; |
3361c7be | 837 | struct hlist_head *head; |
1da177e4 | 838 | ino_t res; |
3361c7be | 839 | |
1da177e4 | 840 | spin_lock(&inode_lock); |
3361c7be JL |
841 | do { |
842 | if (counter <= max_reserved) | |
843 | counter = max_reserved + 1; | |
1da177e4 | 844 | res = counter++; |
3361c7be | 845 | head = inode_hashtable + hash(sb, res); |
1da177e4 | 846 | inode = find_inode_fast(sb, head, res); |
3361c7be JL |
847 | } while (inode != NULL); |
848 | spin_unlock(&inode_lock); | |
1da177e4 | 849 | |
3361c7be JL |
850 | return res; |
851 | } | |
1da177e4 LT |
852 | EXPORT_SYMBOL(iunique); |
853 | ||
854 | struct inode *igrab(struct inode *inode) | |
855 | { | |
856 | spin_lock(&inode_lock); | |
4a3b0a49 | 857 | if (!(inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE))) |
1da177e4 LT |
858 | __iget(inode); |
859 | else | |
860 | /* | |
861 | * Handle the case where s_op->clear_inode is not been | |
862 | * called yet, and somebody is calling igrab | |
863 | * while the inode is getting freed. | |
864 | */ | |
865 | inode = NULL; | |
866 | spin_unlock(&inode_lock); | |
867 | return inode; | |
868 | } | |
1da177e4 LT |
869 | EXPORT_SYMBOL(igrab); |
870 | ||
871 | /** | |
872 | * ifind - internal function, you want ilookup5() or iget5(). | |
873 | * @sb: super block of file system to search | |
874 | * @head: the head of the list to search | |
875 | * @test: callback used for comparisons between inodes | |
876 | * @data: opaque data pointer to pass to @test | |
88bd5121 | 877 | * @wait: if true wait for the inode to be unlocked, if false do not |
1da177e4 LT |
878 | * |
879 | * ifind() searches for the inode specified by @data in the inode | |
880 | * cache. This is a generalized version of ifind_fast() for file systems where | |
881 | * the inode number is not sufficient for unique identification of an inode. | |
882 | * | |
883 | * If the inode is in the cache, the inode is returned with an incremented | |
884 | * reference count. | |
885 | * | |
886 | * Otherwise NULL is returned. | |
887 | * | |
888 | * Note, @test is called with the inode_lock held, so can't sleep. | |
889 | */ | |
5d2bea45 | 890 | static struct inode *ifind(struct super_block *sb, |
1da177e4 | 891 | struct hlist_head *head, int (*test)(struct inode *, void *), |
88bd5121 | 892 | void *data, const int wait) |
1da177e4 LT |
893 | { |
894 | struct inode *inode; | |
895 | ||
896 | spin_lock(&inode_lock); | |
897 | inode = find_inode(sb, head, test, data); | |
898 | if (inode) { | |
899 | __iget(inode); | |
900 | spin_unlock(&inode_lock); | |
88bd5121 AA |
901 | if (likely(wait)) |
902 | wait_on_inode(inode); | |
1da177e4 LT |
903 | return inode; |
904 | } | |
905 | spin_unlock(&inode_lock); | |
906 | return NULL; | |
907 | } | |
908 | ||
909 | /** | |
910 | * ifind_fast - internal function, you want ilookup() or iget(). | |
911 | * @sb: super block of file system to search | |
912 | * @head: head of the list to search | |
913 | * @ino: inode number to search for | |
914 | * | |
915 | * ifind_fast() searches for the inode @ino in the inode cache. This is for | |
916 | * file systems where the inode number is sufficient for unique identification | |
917 | * of an inode. | |
918 | * | |
919 | * If the inode is in the cache, the inode is returned with an incremented | |
920 | * reference count. | |
921 | * | |
922 | * Otherwise NULL is returned. | |
923 | */ | |
5d2bea45 | 924 | static struct inode *ifind_fast(struct super_block *sb, |
1da177e4 LT |
925 | struct hlist_head *head, unsigned long ino) |
926 | { | |
927 | struct inode *inode; | |
928 | ||
929 | spin_lock(&inode_lock); | |
930 | inode = find_inode_fast(sb, head, ino); | |
931 | if (inode) { | |
932 | __iget(inode); | |
933 | spin_unlock(&inode_lock); | |
934 | wait_on_inode(inode); | |
935 | return inode; | |
936 | } | |
937 | spin_unlock(&inode_lock); | |
938 | return NULL; | |
939 | } | |
940 | ||
941 | /** | |
88bd5121 | 942 | * ilookup5_nowait - search for an inode in the inode cache |
1da177e4 LT |
943 | * @sb: super block of file system to search |
944 | * @hashval: hash value (usually inode number) to search for | |
945 | * @test: callback used for comparisons between inodes | |
946 | * @data: opaque data pointer to pass to @test | |
947 | * | |
948 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
949 | * @data in the inode cache. This is a generalized version of ilookup() for | |
950 | * file systems where the inode number is not sufficient for unique | |
951 | * identification of an inode. | |
952 | * | |
953 | * If the inode is in the cache, the inode is returned with an incremented | |
88bd5121 AA |
954 | * reference count. Note, the inode lock is not waited upon so you have to be |
955 | * very careful what you do with the returned inode. You probably should be | |
956 | * using ilookup5() instead. | |
957 | * | |
958 | * Otherwise NULL is returned. | |
959 | * | |
960 | * Note, @test is called with the inode_lock held, so can't sleep. | |
961 | */ | |
962 | struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, | |
963 | int (*test)(struct inode *, void *), void *data) | |
964 | { | |
965 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
966 | ||
967 | return ifind(sb, head, test, data, 0); | |
968 | } | |
88bd5121 AA |
969 | EXPORT_SYMBOL(ilookup5_nowait); |
970 | ||
971 | /** | |
972 | * ilookup5 - search for an inode in the inode cache | |
973 | * @sb: super block of file system to search | |
974 | * @hashval: hash value (usually inode number) to search for | |
975 | * @test: callback used for comparisons between inodes | |
976 | * @data: opaque data pointer to pass to @test | |
977 | * | |
978 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
979 | * @data in the inode cache. This is a generalized version of ilookup() for | |
980 | * file systems where the inode number is not sufficient for unique | |
981 | * identification of an inode. | |
982 | * | |
983 | * If the inode is in the cache, the inode lock is waited upon and the inode is | |
984 | * returned with an incremented reference count. | |
1da177e4 LT |
985 | * |
986 | * Otherwise NULL is returned. | |
987 | * | |
988 | * Note, @test is called with the inode_lock held, so can't sleep. | |
989 | */ | |
990 | struct inode *ilookup5(struct super_block *sb, unsigned long hashval, | |
991 | int (*test)(struct inode *, void *), void *data) | |
992 | { | |
993 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
994 | ||
88bd5121 | 995 | return ifind(sb, head, test, data, 1); |
1da177e4 | 996 | } |
1da177e4 LT |
997 | EXPORT_SYMBOL(ilookup5); |
998 | ||
999 | /** | |
1000 | * ilookup - search for an inode in the inode cache | |
1001 | * @sb: super block of file system to search | |
1002 | * @ino: inode number to search for | |
1003 | * | |
1004 | * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache. | |
1005 | * This is for file systems where the inode number is sufficient for unique | |
1006 | * identification of an inode. | |
1007 | * | |
1008 | * If the inode is in the cache, the inode is returned with an incremented | |
1009 | * reference count. | |
1010 | * | |
1011 | * Otherwise NULL is returned. | |
1012 | */ | |
1013 | struct inode *ilookup(struct super_block *sb, unsigned long ino) | |
1014 | { | |
1015 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
1016 | ||
1017 | return ifind_fast(sb, head, ino); | |
1018 | } | |
1da177e4 LT |
1019 | EXPORT_SYMBOL(ilookup); |
1020 | ||
1021 | /** | |
1022 | * iget5_locked - obtain an inode from a mounted file system | |
1023 | * @sb: super block of file system | |
1024 | * @hashval: hash value (usually inode number) to get | |
1025 | * @test: callback used for comparisons between inodes | |
1026 | * @set: callback used to initialize a new struct inode | |
1027 | * @data: opaque data pointer to pass to @test and @set | |
1028 | * | |
1da177e4 LT |
1029 | * iget5_locked() uses ifind() to search for the inode specified by @hashval |
1030 | * and @data in the inode cache and if present it is returned with an increased | |
1031 | * reference count. This is a generalized version of iget_locked() for file | |
1032 | * systems where the inode number is not sufficient for unique identification | |
1033 | * of an inode. | |
1034 | * | |
1035 | * If the inode is not in cache, get_new_inode() is called to allocate a new | |
1036 | * inode and this is returned locked, hashed, and with the I_NEW flag set. The | |
1037 | * file system gets to fill it in before unlocking it via unlock_new_inode(). | |
1038 | * | |
1039 | * Note both @test and @set are called with the inode_lock held, so can't sleep. | |
1040 | */ | |
1041 | struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, | |
1042 | int (*test)(struct inode *, void *), | |
1043 | int (*set)(struct inode *, void *), void *data) | |
1044 | { | |
1045 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
1046 | struct inode *inode; | |
1047 | ||
88bd5121 | 1048 | inode = ifind(sb, head, test, data, 1); |
1da177e4 LT |
1049 | if (inode) |
1050 | return inode; | |
1051 | /* | |
1052 | * get_new_inode() will do the right thing, re-trying the search | |
1053 | * in case it had to block at any point. | |
1054 | */ | |
1055 | return get_new_inode(sb, head, test, set, data); | |
1056 | } | |
1da177e4 LT |
1057 | EXPORT_SYMBOL(iget5_locked); |
1058 | ||
1059 | /** | |
1060 | * iget_locked - obtain an inode from a mounted file system | |
1061 | * @sb: super block of file system | |
1062 | * @ino: inode number to get | |
1063 | * | |
1da177e4 LT |
1064 | * iget_locked() uses ifind_fast() to search for the inode specified by @ino in |
1065 | * the inode cache and if present it is returned with an increased reference | |
1066 | * count. This is for file systems where the inode number is sufficient for | |
1067 | * unique identification of an inode. | |
1068 | * | |
1069 | * If the inode is not in cache, get_new_inode_fast() is called to allocate a | |
1070 | * new inode and this is returned locked, hashed, and with the I_NEW flag set. | |
1071 | * The file system gets to fill it in before unlocking it via | |
1072 | * unlock_new_inode(). | |
1073 | */ | |
1074 | struct inode *iget_locked(struct super_block *sb, unsigned long ino) | |
1075 | { | |
1076 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
1077 | struct inode *inode; | |
1078 | ||
1079 | inode = ifind_fast(sb, head, ino); | |
1080 | if (inode) | |
1081 | return inode; | |
1082 | /* | |
1083 | * get_new_inode_fast() will do the right thing, re-trying the search | |
1084 | * in case it had to block at any point. | |
1085 | */ | |
1086 | return get_new_inode_fast(sb, head, ino); | |
1087 | } | |
1da177e4 LT |
1088 | EXPORT_SYMBOL(iget_locked); |
1089 | ||
261bca86 AV |
1090 | int insert_inode_locked(struct inode *inode) |
1091 | { | |
1092 | struct super_block *sb = inode->i_sb; | |
1093 | ino_t ino = inode->i_ino; | |
1094 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
261bca86 AV |
1095 | |
1096 | inode->i_state |= I_LOCK|I_NEW; | |
1097 | while (1) { | |
72a43d63 AV |
1098 | struct hlist_node *node; |
1099 | struct inode *old = NULL; | |
261bca86 | 1100 | spin_lock(&inode_lock); |
72a43d63 AV |
1101 | hlist_for_each_entry(old, node, head, i_hash) { |
1102 | if (old->i_ino != ino) | |
1103 | continue; | |
1104 | if (old->i_sb != sb) | |
1105 | continue; | |
1106 | if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) | |
1107 | continue; | |
1108 | break; | |
1109 | } | |
1110 | if (likely(!node)) { | |
261bca86 AV |
1111 | hlist_add_head(&inode->i_hash, head); |
1112 | spin_unlock(&inode_lock); | |
1113 | return 0; | |
1114 | } | |
1115 | __iget(old); | |
1116 | spin_unlock(&inode_lock); | |
1117 | wait_on_inode(old); | |
1118 | if (unlikely(!hlist_unhashed(&old->i_hash))) { | |
1119 | iput(old); | |
1120 | return -EBUSY; | |
1121 | } | |
1122 | iput(old); | |
1123 | } | |
1124 | } | |
261bca86 AV |
1125 | EXPORT_SYMBOL(insert_inode_locked); |
1126 | ||
1127 | int insert_inode_locked4(struct inode *inode, unsigned long hashval, | |
1128 | int (*test)(struct inode *, void *), void *data) | |
1129 | { | |
1130 | struct super_block *sb = inode->i_sb; | |
1131 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
261bca86 AV |
1132 | |
1133 | inode->i_state |= I_LOCK|I_NEW; | |
1134 | ||
1135 | while (1) { | |
72a43d63 AV |
1136 | struct hlist_node *node; |
1137 | struct inode *old = NULL; | |
1138 | ||
261bca86 | 1139 | spin_lock(&inode_lock); |
72a43d63 AV |
1140 | hlist_for_each_entry(old, node, head, i_hash) { |
1141 | if (old->i_sb != sb) | |
1142 | continue; | |
1143 | if (!test(old, data)) | |
1144 | continue; | |
1145 | if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) | |
1146 | continue; | |
1147 | break; | |
1148 | } | |
1149 | if (likely(!node)) { | |
261bca86 AV |
1150 | hlist_add_head(&inode->i_hash, head); |
1151 | spin_unlock(&inode_lock); | |
1152 | return 0; | |
1153 | } | |
1154 | __iget(old); | |
1155 | spin_unlock(&inode_lock); | |
1156 | wait_on_inode(old); | |
1157 | if (unlikely(!hlist_unhashed(&old->i_hash))) { | |
1158 | iput(old); | |
1159 | return -EBUSY; | |
1160 | } | |
1161 | iput(old); | |
1162 | } | |
1163 | } | |
261bca86 AV |
1164 | EXPORT_SYMBOL(insert_inode_locked4); |
1165 | ||
1da177e4 LT |
1166 | /** |
1167 | * __insert_inode_hash - hash an inode | |
1168 | * @inode: unhashed inode | |
1169 | * @hashval: unsigned long value used to locate this object in the | |
1170 | * inode_hashtable. | |
1171 | * | |
1172 | * Add an inode to the inode hash for this superblock. | |
1173 | */ | |
1174 | void __insert_inode_hash(struct inode *inode, unsigned long hashval) | |
1175 | { | |
1176 | struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval); | |
1177 | spin_lock(&inode_lock); | |
1178 | hlist_add_head(&inode->i_hash, head); | |
1179 | spin_unlock(&inode_lock); | |
1180 | } | |
1da177e4 LT |
1181 | EXPORT_SYMBOL(__insert_inode_hash); |
1182 | ||
1183 | /** | |
1184 | * remove_inode_hash - remove an inode from the hash | |
1185 | * @inode: inode to unhash | |
1186 | * | |
1187 | * Remove an inode from the superblock. | |
1188 | */ | |
1189 | void remove_inode_hash(struct inode *inode) | |
1190 | { | |
1191 | spin_lock(&inode_lock); | |
1192 | hlist_del_init(&inode->i_hash); | |
1193 | spin_unlock(&inode_lock); | |
1194 | } | |
1da177e4 LT |
1195 | EXPORT_SYMBOL(remove_inode_hash); |
1196 | ||
1197 | /* | |
1198 | * Tell the filesystem that this inode is no longer of any interest and should | |
1199 | * be completely destroyed. | |
1200 | * | |
1201 | * We leave the inode in the inode hash table until *after* the filesystem's | |
1202 | * ->delete_inode completes. This ensures that an iget (such as nfsd might | |
1203 | * instigate) will always find up-to-date information either in the hash or on | |
1204 | * disk. | |
1205 | * | |
1206 | * I_FREEING is set so that no-one will take a new reference to the inode while | |
1207 | * it is being deleted. | |
1208 | */ | |
b32714ba | 1209 | void generic_delete_inode(struct inode *inode) |
1da177e4 | 1210 | { |
ee9b6d61 | 1211 | const struct super_operations *op = inode->i_sb->s_op; |
1da177e4 | 1212 | |
b32714ba AV |
1213 | list_del_init(&inode->i_list); |
1214 | list_del_init(&inode->i_sb_list); | |
7ef0d737 | 1215 | WARN_ON(inode->i_state & I_NEW); |
b32714ba AV |
1216 | inode->i_state |= I_FREEING; |
1217 | inodes_stat.nr_inodes--; | |
1218 | spin_unlock(&inode_lock); | |
1219 | ||
1da177e4 LT |
1220 | security_inode_delete(inode); |
1221 | ||
1222 | if (op->delete_inode) { | |
1223 | void (*delete)(struct inode *) = op->delete_inode; | |
1224 | if (!is_bad_inode(inode)) | |
9e3509e2 | 1225 | vfs_dq_init(inode); |
e85b5652 MF |
1226 | /* Filesystems implementing their own |
1227 | * s_op->delete_inode are required to call | |
1228 | * truncate_inode_pages and clear_inode() | |
1229 | * internally */ | |
1da177e4 | 1230 | delete(inode); |
e85b5652 MF |
1231 | } else { |
1232 | truncate_inode_pages(&inode->i_data, 0); | |
1da177e4 | 1233 | clear_inode(inode); |
e85b5652 | 1234 | } |
1da177e4 LT |
1235 | spin_lock(&inode_lock); |
1236 | hlist_del_init(&inode->i_hash); | |
1237 | spin_unlock(&inode_lock); | |
1238 | wake_up_inode(inode); | |
b7542f8c | 1239 | BUG_ON(inode->i_state != I_CLEAR); |
1da177e4 LT |
1240 | destroy_inode(inode); |
1241 | } | |
1da177e4 LT |
1242 | EXPORT_SYMBOL(generic_delete_inode); |
1243 | ||
22fe4042 JK |
1244 | /** |
1245 | * generic_detach_inode - remove inode from inode lists | |
1246 | * @inode: inode to remove | |
1247 | * | |
1248 | * Remove inode from inode lists, write it if it's dirty. This is just an | |
1249 | * internal VFS helper exported for hugetlbfs. Do not use! | |
1250 | * | |
1251 | * Returns 1 if inode should be completely destroyed. | |
1252 | */ | |
1253 | int generic_detach_inode(struct inode *inode) | |
1da177e4 LT |
1254 | { |
1255 | struct super_block *sb = inode->i_sb; | |
1256 | ||
1257 | if (!hlist_unhashed(&inode->i_hash)) { | |
1c0eeaf5 | 1258 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) |
1da177e4 LT |
1259 | list_move(&inode->i_list, &inode_unused); |
1260 | inodes_stat.nr_unused++; | |
acb0c854 | 1261 | if (sb->s_flags & MS_ACTIVE) { |
991114c6 | 1262 | spin_unlock(&inode_lock); |
22fe4042 | 1263 | return 0; |
991114c6 | 1264 | } |
7ef0d737 | 1265 | WARN_ON(inode->i_state & I_NEW); |
991114c6 AV |
1266 | inode->i_state |= I_WILL_FREE; |
1267 | spin_unlock(&inode_lock); | |
1da177e4 LT |
1268 | write_inode_now(inode, 1); |
1269 | spin_lock(&inode_lock); | |
7ef0d737 | 1270 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1271 | inode->i_state &= ~I_WILL_FREE; |
1da177e4 LT |
1272 | inodes_stat.nr_unused--; |
1273 | hlist_del_init(&inode->i_hash); | |
1274 | } | |
1275 | list_del_init(&inode->i_list); | |
1276 | list_del_init(&inode->i_sb_list); | |
7ef0d737 | 1277 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1278 | inode->i_state |= I_FREEING; |
1da177e4 LT |
1279 | inodes_stat.nr_inodes--; |
1280 | spin_unlock(&inode_lock); | |
22fe4042 JK |
1281 | return 1; |
1282 | } | |
1283 | EXPORT_SYMBOL_GPL(generic_detach_inode); | |
1284 | ||
1285 | static void generic_forget_inode(struct inode *inode) | |
1286 | { | |
1287 | if (!generic_detach_inode(inode)) | |
1288 | return; | |
1da177e4 LT |
1289 | if (inode->i_data.nrpages) |
1290 | truncate_inode_pages(&inode->i_data, 0); | |
1291 | clear_inode(inode); | |
7f04c26d | 1292 | wake_up_inode(inode); |
1da177e4 LT |
1293 | destroy_inode(inode); |
1294 | } | |
1295 | ||
1296 | /* | |
1297 | * Normal UNIX filesystem behaviour: delete the | |
1298 | * inode when the usage count drops to zero, and | |
1299 | * i_nlink is zero. | |
1300 | */ | |
cb2c0233 | 1301 | void generic_drop_inode(struct inode *inode) |
1da177e4 LT |
1302 | { |
1303 | if (!inode->i_nlink) | |
1304 | generic_delete_inode(inode); | |
1305 | else | |
1306 | generic_forget_inode(inode); | |
1307 | } | |
cb2c0233 MF |
1308 | EXPORT_SYMBOL_GPL(generic_drop_inode); |
1309 | ||
1da177e4 LT |
1310 | /* |
1311 | * Called when we're dropping the last reference | |
6b3304b5 | 1312 | * to an inode. |
1da177e4 LT |
1313 | * |
1314 | * Call the FS "drop()" function, defaulting to | |
1315 | * the legacy UNIX filesystem behaviour.. | |
1316 | * | |
1317 | * NOTE! NOTE! NOTE! We're called with the inode lock | |
1318 | * held, and the drop function is supposed to release | |
1319 | * the lock! | |
1320 | */ | |
1321 | static inline void iput_final(struct inode *inode) | |
1322 | { | |
ee9b6d61 | 1323 | const struct super_operations *op = inode->i_sb->s_op; |
1da177e4 LT |
1324 | void (*drop)(struct inode *) = generic_drop_inode; |
1325 | ||
1326 | if (op && op->drop_inode) | |
1327 | drop = op->drop_inode; | |
1328 | drop(inode); | |
1329 | } | |
1330 | ||
1331 | /** | |
6b3304b5 | 1332 | * iput - put an inode |
1da177e4 LT |
1333 | * @inode: inode to put |
1334 | * | |
1335 | * Puts an inode, dropping its usage count. If the inode use count hits | |
1336 | * zero, the inode is then freed and may also be destroyed. | |
1337 | * | |
1338 | * Consequently, iput() can sleep. | |
1339 | */ | |
1340 | void iput(struct inode *inode) | |
1341 | { | |
1342 | if (inode) { | |
1da177e4 LT |
1343 | BUG_ON(inode->i_state == I_CLEAR); |
1344 | ||
1da177e4 LT |
1345 | if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) |
1346 | iput_final(inode); | |
1347 | } | |
1348 | } | |
1da177e4 LT |
1349 | EXPORT_SYMBOL(iput); |
1350 | ||
1351 | /** | |
1352 | * bmap - find a block number in a file | |
1353 | * @inode: inode of file | |
1354 | * @block: block to find | |
1355 | * | |
1356 | * Returns the block number on the device holding the inode that | |
1357 | * is the disk block number for the block of the file requested. | |
1358 | * That is, asked for block 4 of inode 1 the function will return the | |
6b3304b5 | 1359 | * disk block relative to the disk start that holds that block of the |
1da177e4 LT |
1360 | * file. |
1361 | */ | |
6b3304b5 | 1362 | sector_t bmap(struct inode *inode, sector_t block) |
1da177e4 LT |
1363 | { |
1364 | sector_t res = 0; | |
1365 | if (inode->i_mapping->a_ops->bmap) | |
1366 | res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); | |
1367 | return res; | |
1368 | } | |
1da177e4 LT |
1369 | EXPORT_SYMBOL(bmap); |
1370 | ||
11ff6f05 MG |
1371 | /* |
1372 | * With relative atime, only update atime if the previous atime is | |
1373 | * earlier than either the ctime or mtime or if at least a day has | |
1374 | * passed since the last atime update. | |
1375 | */ | |
1376 | static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, | |
1377 | struct timespec now) | |
1378 | { | |
1379 | ||
1380 | if (!(mnt->mnt_flags & MNT_RELATIME)) | |
1381 | return 1; | |
1382 | /* | |
1383 | * Is mtime younger than atime? If yes, update atime: | |
1384 | */ | |
1385 | if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0) | |
1386 | return 1; | |
1387 | /* | |
1388 | * Is ctime younger than atime? If yes, update atime: | |
1389 | */ | |
1390 | if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0) | |
1391 | return 1; | |
1392 | ||
1393 | /* | |
1394 | * Is the previous atime value older than a day? If yes, | |
1395 | * update atime: | |
1396 | */ | |
1397 | if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60) | |
1398 | return 1; | |
1399 | /* | |
1400 | * Good, we can skip the atime update: | |
1401 | */ | |
1402 | return 0; | |
1403 | } | |
1404 | ||
1da177e4 | 1405 | /** |
869243a0 CH |
1406 | * touch_atime - update the access time |
1407 | * @mnt: mount the inode is accessed on | |
7045f37b | 1408 | * @dentry: dentry accessed |
1da177e4 LT |
1409 | * |
1410 | * Update the accessed time on an inode and mark it for writeback. | |
1411 | * This function automatically handles read only file systems and media, | |
1412 | * as well as the "noatime" flag and inode specific "noatime" markers. | |
1413 | */ | |
869243a0 | 1414 | void touch_atime(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4 | 1415 | { |
869243a0 | 1416 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
1417 | struct timespec now; |
1418 | ||
cdb70f3f | 1419 | if (inode->i_flags & S_NOATIME) |
b12536c2 | 1420 | return; |
37756ced | 1421 | if (IS_NOATIME(inode)) |
b12536c2 | 1422 | return; |
b2276138 | 1423 | if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1424 | return; |
47ae32d6 | 1425 | |
cdb70f3f | 1426 | if (mnt->mnt_flags & MNT_NOATIME) |
b12536c2 | 1427 | return; |
cdb70f3f | 1428 | if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1429 | return; |
1da177e4 LT |
1430 | |
1431 | now = current_fs_time(inode->i_sb); | |
11ff6f05 MG |
1432 | |
1433 | if (!relatime_need_update(mnt, inode, now)) | |
b12536c2 | 1434 | return; |
11ff6f05 | 1435 | |
47ae32d6 | 1436 | if (timespec_equal(&inode->i_atime, &now)) |
b12536c2 AK |
1437 | return; |
1438 | ||
1439 | if (mnt_want_write(mnt)) | |
1440 | return; | |
47ae32d6 VH |
1441 | |
1442 | inode->i_atime = now; | |
1443 | mark_inode_dirty_sync(inode); | |
cdb70f3f | 1444 | mnt_drop_write(mnt); |
1da177e4 | 1445 | } |
869243a0 | 1446 | EXPORT_SYMBOL(touch_atime); |
1da177e4 LT |
1447 | |
1448 | /** | |
870f4817 CH |
1449 | * file_update_time - update mtime and ctime time |
1450 | * @file: file accessed | |
1da177e4 | 1451 | * |
870f4817 CH |
1452 | * Update the mtime and ctime members of an inode and mark the inode |
1453 | * for writeback. Note that this function is meant exclusively for | |
1454 | * usage in the file write path of filesystems, and filesystems may | |
1455 | * choose to explicitly ignore update via this function with the | |
2eadfc0e | 1456 | * S_NOCMTIME inode flag, e.g. for network filesystem where these |
870f4817 | 1457 | * timestamps are handled by the server. |
1da177e4 LT |
1458 | */ |
1459 | ||
870f4817 | 1460 | void file_update_time(struct file *file) |
1da177e4 | 1461 | { |
0f7fc9e4 | 1462 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 | 1463 | struct timespec now; |
ce06e0b2 | 1464 | enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0; |
1da177e4 | 1465 | |
ce06e0b2 | 1466 | /* First try to exhaust all avenues to not sync */ |
1da177e4 LT |
1467 | if (IS_NOCMTIME(inode)) |
1468 | return; | |
20ddee2c | 1469 | |
1da177e4 | 1470 | now = current_fs_time(inode->i_sb); |
ce06e0b2 AK |
1471 | if (!timespec_equal(&inode->i_mtime, &now)) |
1472 | sync_it = S_MTIME; | |
1da177e4 | 1473 | |
ce06e0b2 AK |
1474 | if (!timespec_equal(&inode->i_ctime, &now)) |
1475 | sync_it |= S_CTIME; | |
870f4817 | 1476 | |
ce06e0b2 AK |
1477 | if (IS_I_VERSION(inode)) |
1478 | sync_it |= S_VERSION; | |
7a224228 | 1479 | |
ce06e0b2 AK |
1480 | if (!sync_it) |
1481 | return; | |
1482 | ||
1483 | /* Finally allowed to write? Takes lock. */ | |
1484 | if (mnt_want_write_file(file)) | |
1485 | return; | |
1486 | ||
1487 | /* Only change inode inside the lock region */ | |
1488 | if (sync_it & S_VERSION) | |
1489 | inode_inc_iversion(inode); | |
1490 | if (sync_it & S_CTIME) | |
1491 | inode->i_ctime = now; | |
1492 | if (sync_it & S_MTIME) | |
1493 | inode->i_mtime = now; | |
1494 | mark_inode_dirty_sync(inode); | |
20ddee2c | 1495 | mnt_drop_write(file->f_path.mnt); |
1da177e4 | 1496 | } |
870f4817 | 1497 | EXPORT_SYMBOL(file_update_time); |
1da177e4 LT |
1498 | |
1499 | int inode_needs_sync(struct inode *inode) | |
1500 | { | |
1501 | if (IS_SYNC(inode)) | |
1502 | return 1; | |
1503 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) | |
1504 | return 1; | |
1505 | return 0; | |
1506 | } | |
1da177e4 LT |
1507 | EXPORT_SYMBOL(inode_needs_sync); |
1508 | ||
1da177e4 LT |
1509 | int inode_wait(void *word) |
1510 | { | |
1511 | schedule(); | |
1512 | return 0; | |
1513 | } | |
d44dab8d | 1514 | EXPORT_SYMBOL(inode_wait); |
1da177e4 LT |
1515 | |
1516 | /* | |
168a9fd6 MS |
1517 | * If we try to find an inode in the inode hash while it is being |
1518 | * deleted, we have to wait until the filesystem completes its | |
1519 | * deletion before reporting that it isn't found. This function waits | |
1520 | * until the deletion _might_ have completed. Callers are responsible | |
1521 | * to recheck inode state. | |
1522 | * | |
1523 | * It doesn't matter if I_LOCK is not set initially, a call to | |
1524 | * wake_up_inode() after removing from the hash list will DTRT. | |
1525 | * | |
1da177e4 LT |
1526 | * This is called with inode_lock held. |
1527 | */ | |
1528 | static void __wait_on_freeing_inode(struct inode *inode) | |
1529 | { | |
1530 | wait_queue_head_t *wq; | |
1531 | DEFINE_WAIT_BIT(wait, &inode->i_state, __I_LOCK); | |
1da177e4 LT |
1532 | wq = bit_waitqueue(&inode->i_state, __I_LOCK); |
1533 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); | |
1534 | spin_unlock(&inode_lock); | |
1535 | schedule(); | |
1536 | finish_wait(wq, &wait.wait); | |
1537 | spin_lock(&inode_lock); | |
1538 | } | |
1539 | ||
1da177e4 LT |
1540 | static __initdata unsigned long ihash_entries; |
1541 | static int __init set_ihash_entries(char *str) | |
1542 | { | |
1543 | if (!str) | |
1544 | return 0; | |
1545 | ihash_entries = simple_strtoul(str, &str, 0); | |
1546 | return 1; | |
1547 | } | |
1548 | __setup("ihash_entries=", set_ihash_entries); | |
1549 | ||
1550 | /* | |
1551 | * Initialize the waitqueues and inode hash table. | |
1552 | */ | |
1553 | void __init inode_init_early(void) | |
1554 | { | |
1555 | int loop; | |
1556 | ||
1557 | /* If hashes are distributed across NUMA nodes, defer | |
1558 | * hash allocation until vmalloc space is available. | |
1559 | */ | |
1560 | if (hashdist) | |
1561 | return; | |
1562 | ||
1563 | inode_hashtable = | |
1564 | alloc_large_system_hash("Inode-cache", | |
1565 | sizeof(struct hlist_head), | |
1566 | ihash_entries, | |
1567 | 14, | |
1568 | HASH_EARLY, | |
1569 | &i_hash_shift, | |
1570 | &i_hash_mask, | |
1571 | 0); | |
1572 | ||
1573 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1574 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1575 | } | |
1576 | ||
74bf17cf | 1577 | void __init inode_init(void) |
1da177e4 LT |
1578 | { |
1579 | int loop; | |
1580 | ||
1581 | /* inode slab cache */ | |
b0196009 PJ |
1582 | inode_cachep = kmem_cache_create("inode_cache", |
1583 | sizeof(struct inode), | |
1584 | 0, | |
1585 | (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| | |
1586 | SLAB_MEM_SPREAD), | |
20c2df83 | 1587 | init_once); |
8e1f936b | 1588 | register_shrinker(&icache_shrinker); |
1da177e4 LT |
1589 | |
1590 | /* Hash may have been set up in inode_init_early */ | |
1591 | if (!hashdist) | |
1592 | return; | |
1593 | ||
1594 | inode_hashtable = | |
1595 | alloc_large_system_hash("Inode-cache", | |
1596 | sizeof(struct hlist_head), | |
1597 | ihash_entries, | |
1598 | 14, | |
1599 | 0, | |
1600 | &i_hash_shift, | |
1601 | &i_hash_mask, | |
1602 | 0); | |
1603 | ||
1604 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1605 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1606 | } | |
1607 | ||
1608 | void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) | |
1609 | { | |
1610 | inode->i_mode = mode; | |
1611 | if (S_ISCHR(mode)) { | |
1612 | inode->i_fop = &def_chr_fops; | |
1613 | inode->i_rdev = rdev; | |
1614 | } else if (S_ISBLK(mode)) { | |
1615 | inode->i_fop = &def_blk_fops; | |
1616 | inode->i_rdev = rdev; | |
1617 | } else if (S_ISFIFO(mode)) | |
1618 | inode->i_fop = &def_fifo_fops; | |
1619 | else if (S_ISSOCK(mode)) | |
1620 | inode->i_fop = &bad_sock_fops; | |
1621 | else | |
af0d9ae8 MK |
1622 | printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for" |
1623 | " inode %s:%lu\n", mode, inode->i_sb->s_id, | |
1624 | inode->i_ino); | |
1da177e4 LT |
1625 | } |
1626 | EXPORT_SYMBOL(init_special_inode); |