Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/inode.c | |
3 | * | |
4 | * (C) 1997 Linus Torvalds | |
5 | */ | |
6 | ||
1da177e4 LT |
7 | #include <linux/fs.h> |
8 | #include <linux/mm.h> | |
9 | #include <linux/dcache.h> | |
10 | #include <linux/init.h> | |
1da177e4 LT |
11 | #include <linux/slab.h> |
12 | #include <linux/writeback.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/backing-dev.h> | |
15 | #include <linux/wait.h> | |
88e0fbc4 | 16 | #include <linux/rwsem.h> |
1da177e4 LT |
17 | #include <linux/hash.h> |
18 | #include <linux/swap.h> | |
19 | #include <linux/security.h> | |
20 | #include <linux/pagemap.h> | |
21 | #include <linux/cdev.h> | |
22 | #include <linux/bootmem.h> | |
0eeca283 | 23 | #include <linux/inotify.h> |
3be25f49 | 24 | #include <linux/fsnotify.h> |
fc33a7bb | 25 | #include <linux/mount.h> |
efaee192 | 26 | #include <linux/async.h> |
f19d4a8f | 27 | #include <linux/posix_acl.h> |
1da177e4 LT |
28 | |
29 | /* | |
30 | * This is needed for the following functions: | |
31 | * - inode_has_buffers | |
32 | * - invalidate_inode_buffers | |
1da177e4 LT |
33 | * - invalidate_bdev |
34 | * | |
35 | * FIXME: remove all knowledge of the buffer layer from this file | |
36 | */ | |
37 | #include <linux/buffer_head.h> | |
38 | ||
39 | /* | |
40 | * New inode.c implementation. | |
41 | * | |
42 | * This implementation has the basic premise of trying | |
43 | * to be extremely low-overhead and SMP-safe, yet be | |
44 | * simple enough to be "obviously correct". | |
45 | * | |
46 | * Famous last words. | |
47 | */ | |
48 | ||
49 | /* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */ | |
50 | ||
51 | /* #define INODE_PARANOIA 1 */ | |
52 | /* #define INODE_DEBUG 1 */ | |
53 | ||
54 | /* | |
55 | * Inode lookup is no longer as critical as it used to be: | |
56 | * most of the lookups are going to be through the dcache. | |
57 | */ | |
58 | #define I_HASHBITS i_hash_shift | |
59 | #define I_HASHMASK i_hash_mask | |
60 | ||
fa3536cc ED |
61 | static unsigned int i_hash_mask __read_mostly; |
62 | static unsigned int i_hash_shift __read_mostly; | |
1da177e4 LT |
63 | |
64 | /* | |
65 | * Each inode can be on two separate lists. One is | |
66 | * the hash list of the inode, used for lookups. The | |
67 | * other linked list is the "type" list: | |
68 | * "in_use" - valid inode, i_count > 0, i_nlink > 0 | |
69 | * "dirty" - as "in_use" but also dirty | |
70 | * "unused" - valid inode, i_count = 0 | |
71 | * | |
72 | * A "dirty" list is maintained for each super block, | |
73 | * allowing for low-overhead inode sync() operations. | |
74 | */ | |
75 | ||
76 | LIST_HEAD(inode_in_use); | |
77 | LIST_HEAD(inode_unused); | |
fa3536cc | 78 | static struct hlist_head *inode_hashtable __read_mostly; |
1da177e4 LT |
79 | |
80 | /* | |
81 | * A simple spinlock to protect the list manipulations. | |
82 | * | |
83 | * NOTE! You also have to own the lock if you change | |
84 | * the i_state of an inode while it is in use.. | |
85 | */ | |
86 | DEFINE_SPINLOCK(inode_lock); | |
87 | ||
88 | /* | |
88e0fbc4 | 89 | * iprune_sem provides exclusion between the kswapd or try_to_free_pages |
1da177e4 LT |
90 | * icache shrinking path, and the umount path. Without this exclusion, |
91 | * by the time prune_icache calls iput for the inode whose pages it has | |
92 | * been invalidating, or by the time it calls clear_inode & destroy_inode | |
93 | * from its final dispose_list, the struct super_block they refer to | |
94 | * (for inode->i_sb->s_op) may already have been freed and reused. | |
88e0fbc4 NP |
95 | * |
96 | * We make this an rwsem because the fastpath is icache shrinking. In | |
97 | * some cases a filesystem may be doing a significant amount of work in | |
98 | * its inode reclaim code, so this should improve parallelism. | |
1da177e4 | 99 | */ |
88e0fbc4 | 100 | static DECLARE_RWSEM(iprune_sem); |
1da177e4 LT |
101 | |
102 | /* | |
103 | * Statistics gathering.. | |
104 | */ | |
105 | struct inodes_stat_t inodes_stat; | |
106 | ||
6b3304b5 | 107 | static struct kmem_cache *inode_cachep __read_mostly; |
1da177e4 | 108 | |
1c0eeaf5 JE |
109 | static void wake_up_inode(struct inode *inode) |
110 | { | |
111 | /* | |
112 | * Prevent speculative execution through spin_unlock(&inode_lock); | |
113 | */ | |
114 | smp_mb(); | |
eaff8079 | 115 | wake_up_bit(&inode->i_state, __I_NEW); |
1c0eeaf5 JE |
116 | } |
117 | ||
2cb1599f DC |
118 | /** |
119 | * inode_init_always - perform inode structure intialisation | |
0bc02f3f RD |
120 | * @sb: superblock inode belongs to |
121 | * @inode: inode to initialise | |
2cb1599f DC |
122 | * |
123 | * These are initializations that need to be done on every inode | |
124 | * allocation as the fields are not initialised by slab allocation. | |
125 | */ | |
54e34621 | 126 | int inode_init_always(struct super_block *sb, struct inode *inode) |
1da177e4 | 127 | { |
f5e54d6e | 128 | static const struct address_space_operations empty_aops; |
6e1d5dcc | 129 | static const struct inode_operations empty_iops; |
99ac48f5 | 130 | static const struct file_operations empty_fops; |
6b3304b5 | 131 | struct address_space *const mapping = &inode->i_data; |
2cb1599f DC |
132 | |
133 | inode->i_sb = sb; | |
134 | inode->i_blkbits = sb->s_blocksize_bits; | |
135 | inode->i_flags = 0; | |
136 | atomic_set(&inode->i_count, 1); | |
137 | inode->i_op = &empty_iops; | |
138 | inode->i_fop = &empty_fops; | |
139 | inode->i_nlink = 1; | |
56ff5efa AV |
140 | inode->i_uid = 0; |
141 | inode->i_gid = 0; | |
2cb1599f DC |
142 | atomic_set(&inode->i_writecount, 0); |
143 | inode->i_size = 0; | |
144 | inode->i_blocks = 0; | |
145 | inode->i_bytes = 0; | |
146 | inode->i_generation = 0; | |
1da177e4 | 147 | #ifdef CONFIG_QUOTA |
2cb1599f | 148 | memset(&inode->i_dquot, 0, sizeof(inode->i_dquot)); |
1da177e4 | 149 | #endif |
2cb1599f DC |
150 | inode->i_pipe = NULL; |
151 | inode->i_bdev = NULL; | |
152 | inode->i_cdev = NULL; | |
153 | inode->i_rdev = 0; | |
154 | inode->dirtied_when = 0; | |
6146f0d5 MZ |
155 | |
156 | if (security_inode_alloc(inode)) | |
54e34621 | 157 | goto out; |
2cb1599f DC |
158 | spin_lock_init(&inode->i_lock); |
159 | lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key); | |
160 | ||
161 | mutex_init(&inode->i_mutex); | |
162 | lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key); | |
163 | ||
164 | init_rwsem(&inode->i_alloc_sem); | |
165 | lockdep_set_class(&inode->i_alloc_sem, &sb->s_type->i_alloc_sem_key); | |
166 | ||
167 | mapping->a_ops = &empty_aops; | |
168 | mapping->host = inode; | |
169 | mapping->flags = 0; | |
3c1d4378 | 170 | mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE); |
2cb1599f DC |
171 | mapping->assoc_mapping = NULL; |
172 | mapping->backing_dev_info = &default_backing_dev_info; | |
173 | mapping->writeback_index = 0; | |
174 | ||
175 | /* | |
176 | * If the block_device provides a backing_dev_info for client | |
177 | * inodes then use that. Otherwise the inode share the bdev's | |
178 | * backing_dev_info. | |
179 | */ | |
180 | if (sb->s_bdev) { | |
181 | struct backing_dev_info *bdi; | |
182 | ||
2c96ce9f | 183 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; |
2cb1599f DC |
184 | mapping->backing_dev_info = bdi; |
185 | } | |
186 | inode->i_private = NULL; | |
187 | inode->i_mapping = mapping; | |
f19d4a8f AV |
188 | #ifdef CONFIG_FS_POSIX_ACL |
189 | inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; | |
190 | #endif | |
2cb1599f | 191 | |
3be25f49 EP |
192 | #ifdef CONFIG_FSNOTIFY |
193 | inode->i_fsnotify_mask = 0; | |
194 | #endif | |
195 | ||
54e34621 | 196 | return 0; |
54e34621 CH |
197 | out: |
198 | return -ENOMEM; | |
1da177e4 | 199 | } |
2cb1599f DC |
200 | EXPORT_SYMBOL(inode_init_always); |
201 | ||
202 | static struct inode *alloc_inode(struct super_block *sb) | |
203 | { | |
204 | struct inode *inode; | |
205 | ||
206 | if (sb->s_op->alloc_inode) | |
207 | inode = sb->s_op->alloc_inode(sb); | |
208 | else | |
209 | inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL); | |
210 | ||
54e34621 CH |
211 | if (!inode) |
212 | return NULL; | |
213 | ||
214 | if (unlikely(inode_init_always(sb, inode))) { | |
215 | if (inode->i_sb->s_op->destroy_inode) | |
216 | inode->i_sb->s_op->destroy_inode(inode); | |
217 | else | |
218 | kmem_cache_free(inode_cachep, inode); | |
219 | return NULL; | |
220 | } | |
221 | ||
222 | return inode; | |
2cb1599f | 223 | } |
1da177e4 | 224 | |
2e00c97e | 225 | void __destroy_inode(struct inode *inode) |
1da177e4 | 226 | { |
b7542f8c | 227 | BUG_ON(inode_has_buffers(inode)); |
1da177e4 | 228 | security_inode_free(inode); |
3be25f49 | 229 | fsnotify_inode_delete(inode); |
f19d4a8f AV |
230 | #ifdef CONFIG_FS_POSIX_ACL |
231 | if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED) | |
232 | posix_acl_release(inode->i_acl); | |
233 | if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) | |
234 | posix_acl_release(inode->i_default_acl); | |
235 | #endif | |
2e00c97e CH |
236 | } |
237 | EXPORT_SYMBOL(__destroy_inode); | |
238 | ||
239 | void destroy_inode(struct inode *inode) | |
240 | { | |
241 | __destroy_inode(inode); | |
1da177e4 LT |
242 | if (inode->i_sb->s_op->destroy_inode) |
243 | inode->i_sb->s_op->destroy_inode(inode); | |
244 | else | |
245 | kmem_cache_free(inode_cachep, (inode)); | |
246 | } | |
1da177e4 LT |
247 | |
248 | /* | |
249 | * These are initializations that only need to be done | |
250 | * once, because the fields are idempotent across use | |
251 | * of the inode, so let the slab aware of that. | |
252 | */ | |
253 | void inode_init_once(struct inode *inode) | |
254 | { | |
255 | memset(inode, 0, sizeof(*inode)); | |
256 | INIT_HLIST_NODE(&inode->i_hash); | |
257 | INIT_LIST_HEAD(&inode->i_dentry); | |
258 | INIT_LIST_HEAD(&inode->i_devices); | |
1da177e4 | 259 | INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); |
19fd6231 | 260 | spin_lock_init(&inode->i_data.tree_lock); |
1da177e4 LT |
261 | spin_lock_init(&inode->i_data.i_mmap_lock); |
262 | INIT_LIST_HEAD(&inode->i_data.private_list); | |
263 | spin_lock_init(&inode->i_data.private_lock); | |
264 | INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap); | |
265 | INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); | |
1da177e4 | 266 | i_size_ordered_init(inode); |
0eeca283 RL |
267 | #ifdef CONFIG_INOTIFY |
268 | INIT_LIST_HEAD(&inode->inotify_watches); | |
d4f9af9d | 269 | mutex_init(&inode->inotify_mutex); |
0eeca283 | 270 | #endif |
3be25f49 EP |
271 | #ifdef CONFIG_FSNOTIFY |
272 | INIT_HLIST_HEAD(&inode->i_fsnotify_mark_entries); | |
273 | #endif | |
1da177e4 | 274 | } |
1da177e4 LT |
275 | EXPORT_SYMBOL(inode_init_once); |
276 | ||
51cc5068 | 277 | static void init_once(void *foo) |
1da177e4 | 278 | { |
6b3304b5 | 279 | struct inode *inode = (struct inode *) foo; |
1da177e4 | 280 | |
a35afb83 | 281 | inode_init_once(inode); |
1da177e4 LT |
282 | } |
283 | ||
284 | /* | |
285 | * inode_lock must be held | |
286 | */ | |
6b3304b5 | 287 | void __iget(struct inode *inode) |
1da177e4 | 288 | { |
2e147f1e | 289 | if (atomic_inc_return(&inode->i_count) != 1) |
1da177e4 | 290 | return; |
2e147f1e | 291 | |
1c0eeaf5 | 292 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) |
1da177e4 LT |
293 | list_move(&inode->i_list, &inode_in_use); |
294 | inodes_stat.nr_unused--; | |
295 | } | |
296 | ||
297 | /** | |
298 | * clear_inode - clear an inode | |
299 | * @inode: inode to clear | |
300 | * | |
301 | * This is called by the filesystem to tell us | |
302 | * that the inode is no longer useful. We just | |
303 | * terminate it with extreme prejudice. | |
304 | */ | |
305 | void clear_inode(struct inode *inode) | |
306 | { | |
307 | might_sleep(); | |
308 | invalidate_inode_buffers(inode); | |
6b3304b5 | 309 | |
b7542f8c ES |
310 | BUG_ON(inode->i_data.nrpages); |
311 | BUG_ON(!(inode->i_state & I_FREEING)); | |
312 | BUG_ON(inode->i_state & I_CLEAR); | |
1c0eeaf5 | 313 | inode_sync_wait(inode); |
acb0c854 | 314 | if (inode->i_sb->s_op->clear_inode) |
1da177e4 | 315 | inode->i_sb->s_op->clear_inode(inode); |
eaf796e7 | 316 | if (S_ISBLK(inode->i_mode) && inode->i_bdev) |
1da177e4 | 317 | bd_forget(inode); |
577c4eb0 | 318 | if (S_ISCHR(inode->i_mode) && inode->i_cdev) |
1da177e4 LT |
319 | cd_forget(inode); |
320 | inode->i_state = I_CLEAR; | |
321 | } | |
1da177e4 LT |
322 | EXPORT_SYMBOL(clear_inode); |
323 | ||
324 | /* | |
325 | * dispose_list - dispose of the contents of a local list | |
326 | * @head: the head of the list to free | |
327 | * | |
328 | * Dispose-list gets a local list with local inodes in it, so it doesn't | |
329 | * need to worry about list corruption and SMP locks. | |
330 | */ | |
331 | static void dispose_list(struct list_head *head) | |
332 | { | |
333 | int nr_disposed = 0; | |
334 | ||
335 | while (!list_empty(head)) { | |
336 | struct inode *inode; | |
337 | ||
b5e61818 | 338 | inode = list_first_entry(head, struct inode, i_list); |
1da177e4 LT |
339 | list_del(&inode->i_list); |
340 | ||
341 | if (inode->i_data.nrpages) | |
342 | truncate_inode_pages(&inode->i_data, 0); | |
343 | clear_inode(inode); | |
4120db47 AB |
344 | |
345 | spin_lock(&inode_lock); | |
346 | hlist_del_init(&inode->i_hash); | |
347 | list_del_init(&inode->i_sb_list); | |
348 | spin_unlock(&inode_lock); | |
349 | ||
350 | wake_up_inode(inode); | |
1da177e4 LT |
351 | destroy_inode(inode); |
352 | nr_disposed++; | |
353 | } | |
354 | spin_lock(&inode_lock); | |
355 | inodes_stat.nr_inodes -= nr_disposed; | |
356 | spin_unlock(&inode_lock); | |
357 | } | |
358 | ||
359 | /* | |
360 | * Invalidate all inodes for a device. | |
361 | */ | |
362 | static int invalidate_list(struct list_head *head, struct list_head *dispose) | |
363 | { | |
364 | struct list_head *next; | |
365 | int busy = 0, count = 0; | |
366 | ||
367 | next = head->next; | |
368 | for (;;) { | |
6b3304b5 MK |
369 | struct list_head *tmp = next; |
370 | struct inode *inode; | |
1da177e4 LT |
371 | |
372 | /* | |
373 | * We can reschedule here without worrying about the list's | |
374 | * consistency because the per-sb list of inodes must not | |
88e0fbc4 | 375 | * change during umount anymore, and because iprune_sem keeps |
1da177e4 LT |
376 | * shrink_icache_memory() away. |
377 | */ | |
378 | cond_resched_lock(&inode_lock); | |
379 | ||
380 | next = next->next; | |
381 | if (tmp == head) | |
382 | break; | |
383 | inode = list_entry(tmp, struct inode, i_sb_list); | |
aabb8fdb NP |
384 | if (inode->i_state & I_NEW) |
385 | continue; | |
1da177e4 LT |
386 | invalidate_inode_buffers(inode); |
387 | if (!atomic_read(&inode->i_count)) { | |
1da177e4 | 388 | list_move(&inode->i_list, dispose); |
7ef0d737 | 389 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 LT |
390 | inode->i_state |= I_FREEING; |
391 | count++; | |
392 | continue; | |
393 | } | |
394 | busy = 1; | |
395 | } | |
396 | /* only unused inodes may be cached with i_count zero */ | |
397 | inodes_stat.nr_unused -= count; | |
398 | return busy; | |
399 | } | |
400 | ||
1da177e4 LT |
401 | /** |
402 | * invalidate_inodes - discard the inodes on a device | |
403 | * @sb: superblock | |
404 | * | |
405 | * Discard all of the inodes for a given superblock. If the discard | |
406 | * fails because there are busy inodes then a non zero value is returned. | |
407 | * If the discard is successful all the inodes have been discarded. | |
408 | */ | |
6b3304b5 | 409 | int invalidate_inodes(struct super_block *sb) |
1da177e4 LT |
410 | { |
411 | int busy; | |
412 | LIST_HEAD(throw_away); | |
413 | ||
88e0fbc4 | 414 | down_write(&iprune_sem); |
1da177e4 | 415 | spin_lock(&inode_lock); |
0eeca283 | 416 | inotify_unmount_inodes(&sb->s_inodes); |
164bc619 | 417 | fsnotify_unmount_inodes(&sb->s_inodes); |
1da177e4 LT |
418 | busy = invalidate_list(&sb->s_inodes, &throw_away); |
419 | spin_unlock(&inode_lock); | |
420 | ||
421 | dispose_list(&throw_away); | |
88e0fbc4 | 422 | up_write(&iprune_sem); |
1da177e4 LT |
423 | |
424 | return busy; | |
425 | } | |
1da177e4 | 426 | EXPORT_SYMBOL(invalidate_inodes); |
1da177e4 LT |
427 | |
428 | static int can_unuse(struct inode *inode) | |
429 | { | |
430 | if (inode->i_state) | |
431 | return 0; | |
432 | if (inode_has_buffers(inode)) | |
433 | return 0; | |
434 | if (atomic_read(&inode->i_count)) | |
435 | return 0; | |
436 | if (inode->i_data.nrpages) | |
437 | return 0; | |
438 | return 1; | |
439 | } | |
440 | ||
441 | /* | |
442 | * Scan `goal' inodes on the unused list for freeable ones. They are moved to | |
443 | * a temporary list and then are freed outside inode_lock by dispose_list(). | |
444 | * | |
445 | * Any inodes which are pinned purely because of attached pagecache have their | |
446 | * pagecache removed. We expect the final iput() on that inode to add it to | |
447 | * the front of the inode_unused list. So look for it there and if the | |
448 | * inode is still freeable, proceed. The right inode is found 99.9% of the | |
449 | * time in testing on a 4-way. | |
450 | * | |
451 | * If the inode has metadata buffers attached to mapping->private_list then | |
452 | * try to remove them. | |
453 | */ | |
454 | static void prune_icache(int nr_to_scan) | |
455 | { | |
456 | LIST_HEAD(freeable); | |
457 | int nr_pruned = 0; | |
458 | int nr_scanned; | |
459 | unsigned long reap = 0; | |
460 | ||
88e0fbc4 | 461 | down_read(&iprune_sem); |
1da177e4 LT |
462 | spin_lock(&inode_lock); |
463 | for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { | |
464 | struct inode *inode; | |
465 | ||
466 | if (list_empty(&inode_unused)) | |
467 | break; | |
468 | ||
469 | inode = list_entry(inode_unused.prev, struct inode, i_list); | |
470 | ||
471 | if (inode->i_state || atomic_read(&inode->i_count)) { | |
472 | list_move(&inode->i_list, &inode_unused); | |
473 | continue; | |
474 | } | |
475 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { | |
476 | __iget(inode); | |
477 | spin_unlock(&inode_lock); | |
478 | if (remove_inode_buffers(inode)) | |
fc0ecff6 AM |
479 | reap += invalidate_mapping_pages(&inode->i_data, |
480 | 0, -1); | |
1da177e4 LT |
481 | iput(inode); |
482 | spin_lock(&inode_lock); | |
483 | ||
484 | if (inode != list_entry(inode_unused.next, | |
485 | struct inode, i_list)) | |
486 | continue; /* wrong inode or list_empty */ | |
487 | if (!can_unuse(inode)) | |
488 | continue; | |
489 | } | |
1da177e4 | 490 | list_move(&inode->i_list, &freeable); |
7ef0d737 | 491 | WARN_ON(inode->i_state & I_NEW); |
1da177e4 LT |
492 | inode->i_state |= I_FREEING; |
493 | nr_pruned++; | |
494 | } | |
495 | inodes_stat.nr_unused -= nr_pruned; | |
f8891e5e CL |
496 | if (current_is_kswapd()) |
497 | __count_vm_events(KSWAPD_INODESTEAL, reap); | |
498 | else | |
499 | __count_vm_events(PGINODESTEAL, reap); | |
1da177e4 LT |
500 | spin_unlock(&inode_lock); |
501 | ||
502 | dispose_list(&freeable); | |
88e0fbc4 | 503 | up_read(&iprune_sem); |
1da177e4 LT |
504 | } |
505 | ||
506 | /* | |
507 | * shrink_icache_memory() will attempt to reclaim some unused inodes. Here, | |
508 | * "unused" means that no dentries are referring to the inodes: the files are | |
509 | * not open and the dcache references to those inodes have already been | |
510 | * reclaimed. | |
511 | * | |
512 | * This function is passed the number of inodes to scan, and it returns the | |
513 | * total number of remaining possibly-reclaimable inodes. | |
514 | */ | |
7f8275d0 | 515 | static int shrink_icache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask) |
1da177e4 LT |
516 | { |
517 | if (nr) { | |
518 | /* | |
519 | * Nasty deadlock avoidance. We may hold various FS locks, | |
520 | * and we don't want to recurse into the FS that called us | |
521 | * in clear_inode() and friends.. | |
6b3304b5 | 522 | */ |
1da177e4 LT |
523 | if (!(gfp_mask & __GFP_FS)) |
524 | return -1; | |
525 | prune_icache(nr); | |
526 | } | |
527 | return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure; | |
528 | } | |
529 | ||
8e1f936b RR |
530 | static struct shrinker icache_shrinker = { |
531 | .shrink = shrink_icache_memory, | |
532 | .seeks = DEFAULT_SEEKS, | |
533 | }; | |
534 | ||
1da177e4 LT |
535 | static void __wait_on_freeing_inode(struct inode *inode); |
536 | /* | |
537 | * Called with the inode lock held. | |
538 | * NOTE: we are not increasing the inode-refcount, you must call __iget() | |
539 | * by hand after calling find_inode now! This simplifies iunique and won't | |
540 | * add any additional branch in the common code. | |
541 | */ | |
6b3304b5 MK |
542 | static struct inode *find_inode(struct super_block *sb, |
543 | struct hlist_head *head, | |
544 | int (*test)(struct inode *, void *), | |
545 | void *data) | |
1da177e4 LT |
546 | { |
547 | struct hlist_node *node; | |
6b3304b5 | 548 | struct inode *inode = NULL; |
1da177e4 LT |
549 | |
550 | repeat: | |
c5c8be3c | 551 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
552 | if (inode->i_sb != sb) |
553 | continue; | |
554 | if (!test(inode, data)) | |
555 | continue; | |
991114c6 | 556 | if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { |
1da177e4 LT |
557 | __wait_on_freeing_inode(inode); |
558 | goto repeat; | |
559 | } | |
560 | break; | |
561 | } | |
562 | return node ? inode : NULL; | |
563 | } | |
564 | ||
565 | /* | |
566 | * find_inode_fast is the fast path version of find_inode, see the comment at | |
567 | * iget_locked for details. | |
568 | */ | |
6b3304b5 MK |
569 | static struct inode *find_inode_fast(struct super_block *sb, |
570 | struct hlist_head *head, unsigned long ino) | |
1da177e4 LT |
571 | { |
572 | struct hlist_node *node; | |
6b3304b5 | 573 | struct inode *inode = NULL; |
1da177e4 LT |
574 | |
575 | repeat: | |
c5c8be3c | 576 | hlist_for_each_entry(inode, node, head, i_hash) { |
1da177e4 LT |
577 | if (inode->i_ino != ino) |
578 | continue; | |
579 | if (inode->i_sb != sb) | |
580 | continue; | |
991114c6 | 581 | if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { |
1da177e4 LT |
582 | __wait_on_freeing_inode(inode); |
583 | goto repeat; | |
584 | } | |
585 | break; | |
586 | } | |
587 | return node ? inode : NULL; | |
588 | } | |
589 | ||
8290c35f DC |
590 | static unsigned long hash(struct super_block *sb, unsigned long hashval) |
591 | { | |
592 | unsigned long tmp; | |
593 | ||
594 | tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / | |
595 | L1_CACHE_BYTES; | |
596 | tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS); | |
597 | return tmp & I_HASHMASK; | |
598 | } | |
599 | ||
600 | static inline void | |
601 | __inode_add_to_lists(struct super_block *sb, struct hlist_head *head, | |
602 | struct inode *inode) | |
603 | { | |
604 | inodes_stat.nr_inodes++; | |
605 | list_add(&inode->i_list, &inode_in_use); | |
606 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
607 | if (head) | |
608 | hlist_add_head(&inode->i_hash, head); | |
609 | } | |
610 | ||
611 | /** | |
612 | * inode_add_to_lists - add a new inode to relevant lists | |
0bc02f3f RD |
613 | * @sb: superblock inode belongs to |
614 | * @inode: inode to mark in use | |
8290c35f DC |
615 | * |
616 | * When an inode is allocated it needs to be accounted for, added to the in use | |
617 | * list, the owning superblock and the inode hash. This needs to be done under | |
618 | * the inode_lock, so export a function to do this rather than the inode lock | |
619 | * itself. We calculate the hash list to add to here so it is all internal | |
620 | * which requires the caller to have already set up the inode number in the | |
621 | * inode to add. | |
622 | */ | |
623 | void inode_add_to_lists(struct super_block *sb, struct inode *inode) | |
624 | { | |
625 | struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino); | |
626 | ||
627 | spin_lock(&inode_lock); | |
628 | __inode_add_to_lists(sb, head, inode); | |
629 | spin_unlock(&inode_lock); | |
630 | } | |
631 | EXPORT_SYMBOL_GPL(inode_add_to_lists); | |
632 | ||
1da177e4 LT |
633 | /** |
634 | * new_inode - obtain an inode | |
635 | * @sb: superblock | |
636 | * | |
769848c0 | 637 | * Allocates a new inode for given superblock. The default gfp_mask |
3c1d4378 | 638 | * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE. |
769848c0 MG |
639 | * If HIGHMEM pages are unsuitable or it is known that pages allocated |
640 | * for the page cache are not reclaimable or migratable, | |
641 | * mapping_set_gfp_mask() must be called with suitable flags on the | |
642 | * newly created inode's mapping | |
643 | * | |
1da177e4 LT |
644 | */ |
645 | struct inode *new_inode(struct super_block *sb) | |
646 | { | |
866b04fc JL |
647 | /* |
648 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
649 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
650 | * here to attempt to avoid that. | |
651 | */ | |
652 | static unsigned int last_ino; | |
6b3304b5 | 653 | struct inode *inode; |
1da177e4 LT |
654 | |
655 | spin_lock_prefetch(&inode_lock); | |
6b3304b5 | 656 | |
1da177e4 LT |
657 | inode = alloc_inode(sb); |
658 | if (inode) { | |
659 | spin_lock(&inode_lock); | |
8290c35f | 660 | __inode_add_to_lists(sb, NULL, inode); |
1da177e4 LT |
661 | inode->i_ino = ++last_ino; |
662 | inode->i_state = 0; | |
663 | spin_unlock(&inode_lock); | |
664 | } | |
665 | return inode; | |
666 | } | |
1da177e4 LT |
667 | EXPORT_SYMBOL(new_inode); |
668 | ||
669 | void unlock_new_inode(struct inode *inode) | |
670 | { | |
14358e6d | 671 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
1e89a5e1 PZ |
672 | if (inode->i_mode & S_IFDIR) { |
673 | struct file_system_type *type = inode->i_sb->s_type; | |
674 | ||
9a7aa12f JK |
675 | /* Set new key only if filesystem hasn't already changed it */ |
676 | if (!lockdep_match_class(&inode->i_mutex, | |
677 | &type->i_mutex_key)) { | |
678 | /* | |
679 | * ensure nobody is actually holding i_mutex | |
680 | */ | |
681 | mutex_destroy(&inode->i_mutex); | |
682 | mutex_init(&inode->i_mutex); | |
683 | lockdep_set_class(&inode->i_mutex, | |
684 | &type->i_mutex_dir_key); | |
685 | } | |
1e89a5e1 | 686 | } |
14358e6d | 687 | #endif |
1da177e4 | 688 | /* |
eaff8079 | 689 | * This is special! We do not need the spinlock when clearing I_NEW, |
580be083 JK |
690 | * because we're guaranteed that nobody else tries to do anything about |
691 | * the state of the inode when it is locked, as we just created it (so | |
eaff8079 | 692 | * there can be no old holders that haven't tested I_NEW). |
580be083 | 693 | * However we must emit the memory barrier so that other CPUs reliably |
eaff8079 | 694 | * see the clearing of I_NEW after the other inode initialisation has |
580be083 | 695 | * completed. |
1da177e4 | 696 | */ |
580be083 | 697 | smp_mb(); |
eaff8079 CH |
698 | WARN_ON(!(inode->i_state & I_NEW)); |
699 | inode->i_state &= ~I_NEW; | |
1da177e4 LT |
700 | wake_up_inode(inode); |
701 | } | |
1da177e4 LT |
702 | EXPORT_SYMBOL(unlock_new_inode); |
703 | ||
704 | /* | |
705 | * This is called without the inode lock held.. Be careful. | |
706 | * | |
707 | * We no longer cache the sb_flags in i_flags - see fs.h | |
708 | * -- rmk@arm.uk.linux.org | |
709 | */ | |
6b3304b5 MK |
710 | static struct inode *get_new_inode(struct super_block *sb, |
711 | struct hlist_head *head, | |
712 | int (*test)(struct inode *, void *), | |
713 | int (*set)(struct inode *, void *), | |
714 | void *data) | |
1da177e4 | 715 | { |
6b3304b5 | 716 | struct inode *inode; |
1da177e4 LT |
717 | |
718 | inode = alloc_inode(sb); | |
719 | if (inode) { | |
6b3304b5 | 720 | struct inode *old; |
1da177e4 LT |
721 | |
722 | spin_lock(&inode_lock); | |
723 | /* We released the lock, so.. */ | |
724 | old = find_inode(sb, head, test, data); | |
725 | if (!old) { | |
726 | if (set(inode, data)) | |
727 | goto set_failed; | |
728 | ||
8290c35f | 729 | __inode_add_to_lists(sb, head, inode); |
eaff8079 | 730 | inode->i_state = I_NEW; |
1da177e4 LT |
731 | spin_unlock(&inode_lock); |
732 | ||
733 | /* Return the locked inode with I_NEW set, the | |
734 | * caller is responsible for filling in the contents | |
735 | */ | |
736 | return inode; | |
737 | } | |
738 | ||
739 | /* | |
740 | * Uhhuh, somebody else created the same inode under | |
741 | * us. Use the old inode instead of the one we just | |
742 | * allocated. | |
743 | */ | |
744 | __iget(old); | |
745 | spin_unlock(&inode_lock); | |
746 | destroy_inode(inode); | |
747 | inode = old; | |
748 | wait_on_inode(inode); | |
749 | } | |
750 | return inode; | |
751 | ||
752 | set_failed: | |
753 | spin_unlock(&inode_lock); | |
754 | destroy_inode(inode); | |
755 | return NULL; | |
756 | } | |
757 | ||
758 | /* | |
759 | * get_new_inode_fast is the fast path version of get_new_inode, see the | |
760 | * comment at iget_locked for details. | |
761 | */ | |
6b3304b5 MK |
762 | static struct inode *get_new_inode_fast(struct super_block *sb, |
763 | struct hlist_head *head, unsigned long ino) | |
1da177e4 | 764 | { |
6b3304b5 | 765 | struct inode *inode; |
1da177e4 LT |
766 | |
767 | inode = alloc_inode(sb); | |
768 | if (inode) { | |
6b3304b5 | 769 | struct inode *old; |
1da177e4 LT |
770 | |
771 | spin_lock(&inode_lock); | |
772 | /* We released the lock, so.. */ | |
773 | old = find_inode_fast(sb, head, ino); | |
774 | if (!old) { | |
775 | inode->i_ino = ino; | |
8290c35f | 776 | __inode_add_to_lists(sb, head, inode); |
eaff8079 | 777 | inode->i_state = I_NEW; |
1da177e4 LT |
778 | spin_unlock(&inode_lock); |
779 | ||
780 | /* Return the locked inode with I_NEW set, the | |
781 | * caller is responsible for filling in the contents | |
782 | */ | |
783 | return inode; | |
784 | } | |
785 | ||
786 | /* | |
787 | * Uhhuh, somebody else created the same inode under | |
788 | * us. Use the old inode instead of the one we just | |
789 | * allocated. | |
790 | */ | |
791 | __iget(old); | |
792 | spin_unlock(&inode_lock); | |
793 | destroy_inode(inode); | |
794 | inode = old; | |
795 | wait_on_inode(inode); | |
796 | } | |
797 | return inode; | |
798 | } | |
799 | ||
1da177e4 LT |
800 | /** |
801 | * iunique - get a unique inode number | |
802 | * @sb: superblock | |
803 | * @max_reserved: highest reserved inode number | |
804 | * | |
805 | * Obtain an inode number that is unique on the system for a given | |
806 | * superblock. This is used by file systems that have no natural | |
807 | * permanent inode numbering system. An inode number is returned that | |
808 | * is higher than the reserved limit but unique. | |
809 | * | |
810 | * BUGS: | |
811 | * With a large number of inodes live on the file system this function | |
812 | * currently becomes quite slow. | |
813 | */ | |
814 | ino_t iunique(struct super_block *sb, ino_t max_reserved) | |
815 | { | |
866b04fc JL |
816 | /* |
817 | * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW | |
818 | * error if st_ino won't fit in target struct field. Use 32bit counter | |
819 | * here to attempt to avoid that. | |
820 | */ | |
821 | static unsigned int counter; | |
1da177e4 | 822 | struct inode *inode; |
3361c7be | 823 | struct hlist_head *head; |
1da177e4 | 824 | ino_t res; |
3361c7be | 825 | |
1da177e4 | 826 | spin_lock(&inode_lock); |
3361c7be JL |
827 | do { |
828 | if (counter <= max_reserved) | |
829 | counter = max_reserved + 1; | |
1da177e4 | 830 | res = counter++; |
3361c7be | 831 | head = inode_hashtable + hash(sb, res); |
1da177e4 | 832 | inode = find_inode_fast(sb, head, res); |
3361c7be JL |
833 | } while (inode != NULL); |
834 | spin_unlock(&inode_lock); | |
1da177e4 | 835 | |
3361c7be JL |
836 | return res; |
837 | } | |
1da177e4 LT |
838 | EXPORT_SYMBOL(iunique); |
839 | ||
840 | struct inode *igrab(struct inode *inode) | |
841 | { | |
842 | spin_lock(&inode_lock); | |
4a3b0a49 | 843 | if (!(inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE))) |
1da177e4 LT |
844 | __iget(inode); |
845 | else | |
846 | /* | |
847 | * Handle the case where s_op->clear_inode is not been | |
848 | * called yet, and somebody is calling igrab | |
849 | * while the inode is getting freed. | |
850 | */ | |
851 | inode = NULL; | |
852 | spin_unlock(&inode_lock); | |
853 | return inode; | |
854 | } | |
1da177e4 LT |
855 | EXPORT_SYMBOL(igrab); |
856 | ||
857 | /** | |
858 | * ifind - internal function, you want ilookup5() or iget5(). | |
859 | * @sb: super block of file system to search | |
860 | * @head: the head of the list to search | |
861 | * @test: callback used for comparisons between inodes | |
862 | * @data: opaque data pointer to pass to @test | |
88bd5121 | 863 | * @wait: if true wait for the inode to be unlocked, if false do not |
1da177e4 LT |
864 | * |
865 | * ifind() searches for the inode specified by @data in the inode | |
866 | * cache. This is a generalized version of ifind_fast() for file systems where | |
867 | * the inode number is not sufficient for unique identification of an inode. | |
868 | * | |
869 | * If the inode is in the cache, the inode is returned with an incremented | |
870 | * reference count. | |
871 | * | |
872 | * Otherwise NULL is returned. | |
873 | * | |
874 | * Note, @test is called with the inode_lock held, so can't sleep. | |
875 | */ | |
5d2bea45 | 876 | static struct inode *ifind(struct super_block *sb, |
1da177e4 | 877 | struct hlist_head *head, int (*test)(struct inode *, void *), |
88bd5121 | 878 | void *data, const int wait) |
1da177e4 LT |
879 | { |
880 | struct inode *inode; | |
881 | ||
882 | spin_lock(&inode_lock); | |
883 | inode = find_inode(sb, head, test, data); | |
884 | if (inode) { | |
885 | __iget(inode); | |
886 | spin_unlock(&inode_lock); | |
88bd5121 AA |
887 | if (likely(wait)) |
888 | wait_on_inode(inode); | |
1da177e4 LT |
889 | return inode; |
890 | } | |
891 | spin_unlock(&inode_lock); | |
892 | return NULL; | |
893 | } | |
894 | ||
895 | /** | |
896 | * ifind_fast - internal function, you want ilookup() or iget(). | |
897 | * @sb: super block of file system to search | |
898 | * @head: head of the list to search | |
899 | * @ino: inode number to search for | |
900 | * | |
901 | * ifind_fast() searches for the inode @ino in the inode cache. This is for | |
902 | * file systems where the inode number is sufficient for unique identification | |
903 | * of an inode. | |
904 | * | |
905 | * If the inode is in the cache, the inode is returned with an incremented | |
906 | * reference count. | |
907 | * | |
908 | * Otherwise NULL is returned. | |
909 | */ | |
5d2bea45 | 910 | static struct inode *ifind_fast(struct super_block *sb, |
1da177e4 LT |
911 | struct hlist_head *head, unsigned long ino) |
912 | { | |
913 | struct inode *inode; | |
914 | ||
915 | spin_lock(&inode_lock); | |
916 | inode = find_inode_fast(sb, head, ino); | |
917 | if (inode) { | |
918 | __iget(inode); | |
919 | spin_unlock(&inode_lock); | |
920 | wait_on_inode(inode); | |
921 | return inode; | |
922 | } | |
923 | spin_unlock(&inode_lock); | |
924 | return NULL; | |
925 | } | |
926 | ||
927 | /** | |
88bd5121 | 928 | * ilookup5_nowait - search for an inode in the inode cache |
1da177e4 LT |
929 | * @sb: super block of file system to search |
930 | * @hashval: hash value (usually inode number) to search for | |
931 | * @test: callback used for comparisons between inodes | |
932 | * @data: opaque data pointer to pass to @test | |
933 | * | |
934 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
935 | * @data in the inode cache. This is a generalized version of ilookup() for | |
936 | * file systems where the inode number is not sufficient for unique | |
937 | * identification of an inode. | |
938 | * | |
939 | * If the inode is in the cache, the inode is returned with an incremented | |
88bd5121 AA |
940 | * reference count. Note, the inode lock is not waited upon so you have to be |
941 | * very careful what you do with the returned inode. You probably should be | |
942 | * using ilookup5() instead. | |
943 | * | |
944 | * Otherwise NULL is returned. | |
945 | * | |
946 | * Note, @test is called with the inode_lock held, so can't sleep. | |
947 | */ | |
948 | struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, | |
949 | int (*test)(struct inode *, void *), void *data) | |
950 | { | |
951 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
952 | ||
953 | return ifind(sb, head, test, data, 0); | |
954 | } | |
88bd5121 AA |
955 | EXPORT_SYMBOL(ilookup5_nowait); |
956 | ||
957 | /** | |
958 | * ilookup5 - search for an inode in the inode cache | |
959 | * @sb: super block of file system to search | |
960 | * @hashval: hash value (usually inode number) to search for | |
961 | * @test: callback used for comparisons between inodes | |
962 | * @data: opaque data pointer to pass to @test | |
963 | * | |
964 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
965 | * @data in the inode cache. This is a generalized version of ilookup() for | |
966 | * file systems where the inode number is not sufficient for unique | |
967 | * identification of an inode. | |
968 | * | |
969 | * If the inode is in the cache, the inode lock is waited upon and the inode is | |
970 | * returned with an incremented reference count. | |
1da177e4 LT |
971 | * |
972 | * Otherwise NULL is returned. | |
973 | * | |
974 | * Note, @test is called with the inode_lock held, so can't sleep. | |
975 | */ | |
976 | struct inode *ilookup5(struct super_block *sb, unsigned long hashval, | |
977 | int (*test)(struct inode *, void *), void *data) | |
978 | { | |
979 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
980 | ||
88bd5121 | 981 | return ifind(sb, head, test, data, 1); |
1da177e4 | 982 | } |
1da177e4 LT |
983 | EXPORT_SYMBOL(ilookup5); |
984 | ||
985 | /** | |
986 | * ilookup - search for an inode in the inode cache | |
987 | * @sb: super block of file system to search | |
988 | * @ino: inode number to search for | |
989 | * | |
990 | * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache. | |
991 | * This is for file systems where the inode number is sufficient for unique | |
992 | * identification of an inode. | |
993 | * | |
994 | * If the inode is in the cache, the inode is returned with an incremented | |
995 | * reference count. | |
996 | * | |
997 | * Otherwise NULL is returned. | |
998 | */ | |
999 | struct inode *ilookup(struct super_block *sb, unsigned long ino) | |
1000 | { | |
1001 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
1002 | ||
1003 | return ifind_fast(sb, head, ino); | |
1004 | } | |
1da177e4 LT |
1005 | EXPORT_SYMBOL(ilookup); |
1006 | ||
1007 | /** | |
1008 | * iget5_locked - obtain an inode from a mounted file system | |
1009 | * @sb: super block of file system | |
1010 | * @hashval: hash value (usually inode number) to get | |
1011 | * @test: callback used for comparisons between inodes | |
1012 | * @set: callback used to initialize a new struct inode | |
1013 | * @data: opaque data pointer to pass to @test and @set | |
1014 | * | |
1da177e4 LT |
1015 | * iget5_locked() uses ifind() to search for the inode specified by @hashval |
1016 | * and @data in the inode cache and if present it is returned with an increased | |
1017 | * reference count. This is a generalized version of iget_locked() for file | |
1018 | * systems where the inode number is not sufficient for unique identification | |
1019 | * of an inode. | |
1020 | * | |
1021 | * If the inode is not in cache, get_new_inode() is called to allocate a new | |
1022 | * inode and this is returned locked, hashed, and with the I_NEW flag set. The | |
1023 | * file system gets to fill it in before unlocking it via unlock_new_inode(). | |
1024 | * | |
1025 | * Note both @test and @set are called with the inode_lock held, so can't sleep. | |
1026 | */ | |
1027 | struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, | |
1028 | int (*test)(struct inode *, void *), | |
1029 | int (*set)(struct inode *, void *), void *data) | |
1030 | { | |
1031 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
1032 | struct inode *inode; | |
1033 | ||
88bd5121 | 1034 | inode = ifind(sb, head, test, data, 1); |
1da177e4 LT |
1035 | if (inode) |
1036 | return inode; | |
1037 | /* | |
1038 | * get_new_inode() will do the right thing, re-trying the search | |
1039 | * in case it had to block at any point. | |
1040 | */ | |
1041 | return get_new_inode(sb, head, test, set, data); | |
1042 | } | |
1da177e4 LT |
1043 | EXPORT_SYMBOL(iget5_locked); |
1044 | ||
1045 | /** | |
1046 | * iget_locked - obtain an inode from a mounted file system | |
1047 | * @sb: super block of file system | |
1048 | * @ino: inode number to get | |
1049 | * | |
1da177e4 LT |
1050 | * iget_locked() uses ifind_fast() to search for the inode specified by @ino in |
1051 | * the inode cache and if present it is returned with an increased reference | |
1052 | * count. This is for file systems where the inode number is sufficient for | |
1053 | * unique identification of an inode. | |
1054 | * | |
1055 | * If the inode is not in cache, get_new_inode_fast() is called to allocate a | |
1056 | * new inode and this is returned locked, hashed, and with the I_NEW flag set. | |
1057 | * The file system gets to fill it in before unlocking it via | |
1058 | * unlock_new_inode(). | |
1059 | */ | |
1060 | struct inode *iget_locked(struct super_block *sb, unsigned long ino) | |
1061 | { | |
1062 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
1063 | struct inode *inode; | |
1064 | ||
1065 | inode = ifind_fast(sb, head, ino); | |
1066 | if (inode) | |
1067 | return inode; | |
1068 | /* | |
1069 | * get_new_inode_fast() will do the right thing, re-trying the search | |
1070 | * in case it had to block at any point. | |
1071 | */ | |
1072 | return get_new_inode_fast(sb, head, ino); | |
1073 | } | |
1da177e4 LT |
1074 | EXPORT_SYMBOL(iget_locked); |
1075 | ||
261bca86 AV |
1076 | int insert_inode_locked(struct inode *inode) |
1077 | { | |
1078 | struct super_block *sb = inode->i_sb; | |
1079 | ino_t ino = inode->i_ino; | |
1080 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
261bca86 | 1081 | |
eaff8079 | 1082 | inode->i_state |= I_NEW; |
261bca86 | 1083 | while (1) { |
72a43d63 AV |
1084 | struct hlist_node *node; |
1085 | struct inode *old = NULL; | |
261bca86 | 1086 | spin_lock(&inode_lock); |
72a43d63 AV |
1087 | hlist_for_each_entry(old, node, head, i_hash) { |
1088 | if (old->i_ino != ino) | |
1089 | continue; | |
1090 | if (old->i_sb != sb) | |
1091 | continue; | |
1092 | if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) | |
1093 | continue; | |
1094 | break; | |
1095 | } | |
1096 | if (likely(!node)) { | |
261bca86 AV |
1097 | hlist_add_head(&inode->i_hash, head); |
1098 | spin_unlock(&inode_lock); | |
1099 | return 0; | |
1100 | } | |
1101 | __iget(old); | |
1102 | spin_unlock(&inode_lock); | |
1103 | wait_on_inode(old); | |
1104 | if (unlikely(!hlist_unhashed(&old->i_hash))) { | |
1105 | iput(old); | |
1106 | return -EBUSY; | |
1107 | } | |
1108 | iput(old); | |
1109 | } | |
1110 | } | |
261bca86 AV |
1111 | EXPORT_SYMBOL(insert_inode_locked); |
1112 | ||
1113 | int insert_inode_locked4(struct inode *inode, unsigned long hashval, | |
1114 | int (*test)(struct inode *, void *), void *data) | |
1115 | { | |
1116 | struct super_block *sb = inode->i_sb; | |
1117 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
261bca86 | 1118 | |
eaff8079 | 1119 | inode->i_state |= I_NEW; |
261bca86 AV |
1120 | |
1121 | while (1) { | |
72a43d63 AV |
1122 | struct hlist_node *node; |
1123 | struct inode *old = NULL; | |
1124 | ||
261bca86 | 1125 | spin_lock(&inode_lock); |
72a43d63 AV |
1126 | hlist_for_each_entry(old, node, head, i_hash) { |
1127 | if (old->i_sb != sb) | |
1128 | continue; | |
1129 | if (!test(old, data)) | |
1130 | continue; | |
1131 | if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) | |
1132 | continue; | |
1133 | break; | |
1134 | } | |
1135 | if (likely(!node)) { | |
261bca86 AV |
1136 | hlist_add_head(&inode->i_hash, head); |
1137 | spin_unlock(&inode_lock); | |
1138 | return 0; | |
1139 | } | |
1140 | __iget(old); | |
1141 | spin_unlock(&inode_lock); | |
1142 | wait_on_inode(old); | |
1143 | if (unlikely(!hlist_unhashed(&old->i_hash))) { | |
1144 | iput(old); | |
1145 | return -EBUSY; | |
1146 | } | |
1147 | iput(old); | |
1148 | } | |
1149 | } | |
261bca86 AV |
1150 | EXPORT_SYMBOL(insert_inode_locked4); |
1151 | ||
1da177e4 LT |
1152 | /** |
1153 | * __insert_inode_hash - hash an inode | |
1154 | * @inode: unhashed inode | |
1155 | * @hashval: unsigned long value used to locate this object in the | |
1156 | * inode_hashtable. | |
1157 | * | |
1158 | * Add an inode to the inode hash for this superblock. | |
1159 | */ | |
1160 | void __insert_inode_hash(struct inode *inode, unsigned long hashval) | |
1161 | { | |
1162 | struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval); | |
1163 | spin_lock(&inode_lock); | |
1164 | hlist_add_head(&inode->i_hash, head); | |
1165 | spin_unlock(&inode_lock); | |
1166 | } | |
1da177e4 LT |
1167 | EXPORT_SYMBOL(__insert_inode_hash); |
1168 | ||
1169 | /** | |
1170 | * remove_inode_hash - remove an inode from the hash | |
1171 | * @inode: inode to unhash | |
1172 | * | |
1173 | * Remove an inode from the superblock. | |
1174 | */ | |
1175 | void remove_inode_hash(struct inode *inode) | |
1176 | { | |
1177 | spin_lock(&inode_lock); | |
1178 | hlist_del_init(&inode->i_hash); | |
1179 | spin_unlock(&inode_lock); | |
1180 | } | |
1da177e4 LT |
1181 | EXPORT_SYMBOL(remove_inode_hash); |
1182 | ||
1183 | /* | |
1184 | * Tell the filesystem that this inode is no longer of any interest and should | |
1185 | * be completely destroyed. | |
1186 | * | |
1187 | * We leave the inode in the inode hash table until *after* the filesystem's | |
1188 | * ->delete_inode completes. This ensures that an iget (such as nfsd might | |
1189 | * instigate) will always find up-to-date information either in the hash or on | |
1190 | * disk. | |
1191 | * | |
1192 | * I_FREEING is set so that no-one will take a new reference to the inode while | |
1193 | * it is being deleted. | |
1194 | */ | |
b32714ba | 1195 | void generic_delete_inode(struct inode *inode) |
1da177e4 | 1196 | { |
ee9b6d61 | 1197 | const struct super_operations *op = inode->i_sb->s_op; |
1da177e4 | 1198 | |
b32714ba AV |
1199 | list_del_init(&inode->i_list); |
1200 | list_del_init(&inode->i_sb_list); | |
7ef0d737 | 1201 | WARN_ON(inode->i_state & I_NEW); |
b32714ba AV |
1202 | inode->i_state |= I_FREEING; |
1203 | inodes_stat.nr_inodes--; | |
1204 | spin_unlock(&inode_lock); | |
1205 | ||
1da177e4 LT |
1206 | if (op->delete_inode) { |
1207 | void (*delete)(struct inode *) = op->delete_inode; | |
e85b5652 MF |
1208 | /* Filesystems implementing their own |
1209 | * s_op->delete_inode are required to call | |
1210 | * truncate_inode_pages and clear_inode() | |
1211 | * internally */ | |
1da177e4 | 1212 | delete(inode); |
e85b5652 MF |
1213 | } else { |
1214 | truncate_inode_pages(&inode->i_data, 0); | |
1da177e4 | 1215 | clear_inode(inode); |
e85b5652 | 1216 | } |
1da177e4 LT |
1217 | spin_lock(&inode_lock); |
1218 | hlist_del_init(&inode->i_hash); | |
1219 | spin_unlock(&inode_lock); | |
1220 | wake_up_inode(inode); | |
b7542f8c | 1221 | BUG_ON(inode->i_state != I_CLEAR); |
1da177e4 LT |
1222 | destroy_inode(inode); |
1223 | } | |
1da177e4 LT |
1224 | EXPORT_SYMBOL(generic_delete_inode); |
1225 | ||
22fe4042 JK |
1226 | /** |
1227 | * generic_detach_inode - remove inode from inode lists | |
1228 | * @inode: inode to remove | |
1229 | * | |
1230 | * Remove inode from inode lists, write it if it's dirty. This is just an | |
1231 | * internal VFS helper exported for hugetlbfs. Do not use! | |
1232 | * | |
1233 | * Returns 1 if inode should be completely destroyed. | |
1234 | */ | |
1235 | int generic_detach_inode(struct inode *inode) | |
1da177e4 LT |
1236 | { |
1237 | struct super_block *sb = inode->i_sb; | |
1238 | ||
1239 | if (!hlist_unhashed(&inode->i_hash)) { | |
1c0eeaf5 | 1240 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) |
1da177e4 LT |
1241 | list_move(&inode->i_list, &inode_unused); |
1242 | inodes_stat.nr_unused++; | |
acb0c854 | 1243 | if (sb->s_flags & MS_ACTIVE) { |
991114c6 | 1244 | spin_unlock(&inode_lock); |
22fe4042 | 1245 | return 0; |
991114c6 | 1246 | } |
7ef0d737 | 1247 | WARN_ON(inode->i_state & I_NEW); |
991114c6 AV |
1248 | inode->i_state |= I_WILL_FREE; |
1249 | spin_unlock(&inode_lock); | |
1da177e4 LT |
1250 | write_inode_now(inode, 1); |
1251 | spin_lock(&inode_lock); | |
7ef0d737 | 1252 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1253 | inode->i_state &= ~I_WILL_FREE; |
1da177e4 LT |
1254 | inodes_stat.nr_unused--; |
1255 | hlist_del_init(&inode->i_hash); | |
1256 | } | |
1257 | list_del_init(&inode->i_list); | |
1258 | list_del_init(&inode->i_sb_list); | |
7ef0d737 | 1259 | WARN_ON(inode->i_state & I_NEW); |
991114c6 | 1260 | inode->i_state |= I_FREEING; |
1da177e4 LT |
1261 | inodes_stat.nr_inodes--; |
1262 | spin_unlock(&inode_lock); | |
22fe4042 JK |
1263 | return 1; |
1264 | } | |
1265 | EXPORT_SYMBOL_GPL(generic_detach_inode); | |
1266 | ||
1267 | static void generic_forget_inode(struct inode *inode) | |
1268 | { | |
1269 | if (!generic_detach_inode(inode)) | |
1270 | return; | |
1da177e4 LT |
1271 | if (inode->i_data.nrpages) |
1272 | truncate_inode_pages(&inode->i_data, 0); | |
1273 | clear_inode(inode); | |
7f04c26d | 1274 | wake_up_inode(inode); |
1da177e4 LT |
1275 | destroy_inode(inode); |
1276 | } | |
1277 | ||
1278 | /* | |
1279 | * Normal UNIX filesystem behaviour: delete the | |
1280 | * inode when the usage count drops to zero, and | |
1281 | * i_nlink is zero. | |
1282 | */ | |
cb2c0233 | 1283 | void generic_drop_inode(struct inode *inode) |
1da177e4 LT |
1284 | { |
1285 | if (!inode->i_nlink) | |
1286 | generic_delete_inode(inode); | |
1287 | else | |
1288 | generic_forget_inode(inode); | |
1289 | } | |
cb2c0233 MF |
1290 | EXPORT_SYMBOL_GPL(generic_drop_inode); |
1291 | ||
1da177e4 LT |
1292 | /* |
1293 | * Called when we're dropping the last reference | |
6b3304b5 | 1294 | * to an inode. |
1da177e4 LT |
1295 | * |
1296 | * Call the FS "drop()" function, defaulting to | |
1297 | * the legacy UNIX filesystem behaviour.. | |
1298 | * | |
1299 | * NOTE! NOTE! NOTE! We're called with the inode lock | |
1300 | * held, and the drop function is supposed to release | |
1301 | * the lock! | |
1302 | */ | |
1303 | static inline void iput_final(struct inode *inode) | |
1304 | { | |
ee9b6d61 | 1305 | const struct super_operations *op = inode->i_sb->s_op; |
1da177e4 LT |
1306 | void (*drop)(struct inode *) = generic_drop_inode; |
1307 | ||
1308 | if (op && op->drop_inode) | |
1309 | drop = op->drop_inode; | |
1310 | drop(inode); | |
1311 | } | |
1312 | ||
1313 | /** | |
6b3304b5 | 1314 | * iput - put an inode |
1da177e4 LT |
1315 | * @inode: inode to put |
1316 | * | |
1317 | * Puts an inode, dropping its usage count. If the inode use count hits | |
1318 | * zero, the inode is then freed and may also be destroyed. | |
1319 | * | |
1320 | * Consequently, iput() can sleep. | |
1321 | */ | |
1322 | void iput(struct inode *inode) | |
1323 | { | |
1324 | if (inode) { | |
1da177e4 LT |
1325 | BUG_ON(inode->i_state == I_CLEAR); |
1326 | ||
1da177e4 LT |
1327 | if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) |
1328 | iput_final(inode); | |
1329 | } | |
1330 | } | |
1da177e4 LT |
1331 | EXPORT_SYMBOL(iput); |
1332 | ||
1333 | /** | |
1334 | * bmap - find a block number in a file | |
1335 | * @inode: inode of file | |
1336 | * @block: block to find | |
1337 | * | |
1338 | * Returns the block number on the device holding the inode that | |
1339 | * is the disk block number for the block of the file requested. | |
1340 | * That is, asked for block 4 of inode 1 the function will return the | |
6b3304b5 | 1341 | * disk block relative to the disk start that holds that block of the |
1da177e4 LT |
1342 | * file. |
1343 | */ | |
6b3304b5 | 1344 | sector_t bmap(struct inode *inode, sector_t block) |
1da177e4 LT |
1345 | { |
1346 | sector_t res = 0; | |
1347 | if (inode->i_mapping->a_ops->bmap) | |
1348 | res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); | |
1349 | return res; | |
1350 | } | |
1da177e4 LT |
1351 | EXPORT_SYMBOL(bmap); |
1352 | ||
11ff6f05 MG |
1353 | /* |
1354 | * With relative atime, only update atime if the previous atime is | |
1355 | * earlier than either the ctime or mtime or if at least a day has | |
1356 | * passed since the last atime update. | |
1357 | */ | |
1358 | static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, | |
1359 | struct timespec now) | |
1360 | { | |
1361 | ||
1362 | if (!(mnt->mnt_flags & MNT_RELATIME)) | |
1363 | return 1; | |
1364 | /* | |
1365 | * Is mtime younger than atime? If yes, update atime: | |
1366 | */ | |
1367 | if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0) | |
1368 | return 1; | |
1369 | /* | |
1370 | * Is ctime younger than atime? If yes, update atime: | |
1371 | */ | |
1372 | if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0) | |
1373 | return 1; | |
1374 | ||
1375 | /* | |
1376 | * Is the previous atime value older than a day? If yes, | |
1377 | * update atime: | |
1378 | */ | |
1379 | if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60) | |
1380 | return 1; | |
1381 | /* | |
1382 | * Good, we can skip the atime update: | |
1383 | */ | |
1384 | return 0; | |
1385 | } | |
1386 | ||
1da177e4 | 1387 | /** |
869243a0 CH |
1388 | * touch_atime - update the access time |
1389 | * @mnt: mount the inode is accessed on | |
7045f37b | 1390 | * @dentry: dentry accessed |
1da177e4 LT |
1391 | * |
1392 | * Update the accessed time on an inode and mark it for writeback. | |
1393 | * This function automatically handles read only file systems and media, | |
1394 | * as well as the "noatime" flag and inode specific "noatime" markers. | |
1395 | */ | |
869243a0 | 1396 | void touch_atime(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4 | 1397 | { |
869243a0 | 1398 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
1399 | struct timespec now; |
1400 | ||
cdb70f3f | 1401 | if (inode->i_flags & S_NOATIME) |
b12536c2 | 1402 | return; |
37756ced | 1403 | if (IS_NOATIME(inode)) |
b12536c2 | 1404 | return; |
b2276138 | 1405 | if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1406 | return; |
47ae32d6 | 1407 | |
cdb70f3f | 1408 | if (mnt->mnt_flags & MNT_NOATIME) |
b12536c2 | 1409 | return; |
cdb70f3f | 1410 | if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)) |
b12536c2 | 1411 | return; |
1da177e4 LT |
1412 | |
1413 | now = current_fs_time(inode->i_sb); | |
11ff6f05 MG |
1414 | |
1415 | if (!relatime_need_update(mnt, inode, now)) | |
b12536c2 | 1416 | return; |
11ff6f05 | 1417 | |
47ae32d6 | 1418 | if (timespec_equal(&inode->i_atime, &now)) |
b12536c2 AK |
1419 | return; |
1420 | ||
1421 | if (mnt_want_write(mnt)) | |
1422 | return; | |
47ae32d6 VH |
1423 | |
1424 | inode->i_atime = now; | |
1425 | mark_inode_dirty_sync(inode); | |
cdb70f3f | 1426 | mnt_drop_write(mnt); |
1da177e4 | 1427 | } |
869243a0 | 1428 | EXPORT_SYMBOL(touch_atime); |
1da177e4 LT |
1429 | |
1430 | /** | |
870f4817 CH |
1431 | * file_update_time - update mtime and ctime time |
1432 | * @file: file accessed | |
1da177e4 | 1433 | * |
870f4817 CH |
1434 | * Update the mtime and ctime members of an inode and mark the inode |
1435 | * for writeback. Note that this function is meant exclusively for | |
1436 | * usage in the file write path of filesystems, and filesystems may | |
1437 | * choose to explicitly ignore update via this function with the | |
2eadfc0e | 1438 | * S_NOCMTIME inode flag, e.g. for network filesystem where these |
870f4817 | 1439 | * timestamps are handled by the server. |
1da177e4 LT |
1440 | */ |
1441 | ||
870f4817 | 1442 | void file_update_time(struct file *file) |
1da177e4 | 1443 | { |
0f7fc9e4 | 1444 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 | 1445 | struct timespec now; |
ce06e0b2 | 1446 | enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0; |
1da177e4 | 1447 | |
ce06e0b2 | 1448 | /* First try to exhaust all avenues to not sync */ |
1da177e4 LT |
1449 | if (IS_NOCMTIME(inode)) |
1450 | return; | |
20ddee2c | 1451 | |
1da177e4 | 1452 | now = current_fs_time(inode->i_sb); |
ce06e0b2 AK |
1453 | if (!timespec_equal(&inode->i_mtime, &now)) |
1454 | sync_it = S_MTIME; | |
1da177e4 | 1455 | |
ce06e0b2 AK |
1456 | if (!timespec_equal(&inode->i_ctime, &now)) |
1457 | sync_it |= S_CTIME; | |
870f4817 | 1458 | |
ce06e0b2 AK |
1459 | if (IS_I_VERSION(inode)) |
1460 | sync_it |= S_VERSION; | |
7a224228 | 1461 | |
ce06e0b2 AK |
1462 | if (!sync_it) |
1463 | return; | |
1464 | ||
1465 | /* Finally allowed to write? Takes lock. */ | |
1466 | if (mnt_want_write_file(file)) | |
1467 | return; | |
1468 | ||
1469 | /* Only change inode inside the lock region */ | |
1470 | if (sync_it & S_VERSION) | |
1471 | inode_inc_iversion(inode); | |
1472 | if (sync_it & S_CTIME) | |
1473 | inode->i_ctime = now; | |
1474 | if (sync_it & S_MTIME) | |
1475 | inode->i_mtime = now; | |
1476 | mark_inode_dirty_sync(inode); | |
20ddee2c | 1477 | mnt_drop_write(file->f_path.mnt); |
1da177e4 | 1478 | } |
870f4817 | 1479 | EXPORT_SYMBOL(file_update_time); |
1da177e4 LT |
1480 | |
1481 | int inode_needs_sync(struct inode *inode) | |
1482 | { | |
1483 | if (IS_SYNC(inode)) | |
1484 | return 1; | |
1485 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) | |
1486 | return 1; | |
1487 | return 0; | |
1488 | } | |
1da177e4 LT |
1489 | EXPORT_SYMBOL(inode_needs_sync); |
1490 | ||
1da177e4 LT |
1491 | int inode_wait(void *word) |
1492 | { | |
1493 | schedule(); | |
1494 | return 0; | |
1495 | } | |
d44dab8d | 1496 | EXPORT_SYMBOL(inode_wait); |
1da177e4 LT |
1497 | |
1498 | /* | |
168a9fd6 MS |
1499 | * If we try to find an inode in the inode hash while it is being |
1500 | * deleted, we have to wait until the filesystem completes its | |
1501 | * deletion before reporting that it isn't found. This function waits | |
1502 | * until the deletion _might_ have completed. Callers are responsible | |
1503 | * to recheck inode state. | |
1504 | * | |
eaff8079 | 1505 | * It doesn't matter if I_NEW is not set initially, a call to |
168a9fd6 MS |
1506 | * wake_up_inode() after removing from the hash list will DTRT. |
1507 | * | |
1da177e4 LT |
1508 | * This is called with inode_lock held. |
1509 | */ | |
1510 | static void __wait_on_freeing_inode(struct inode *inode) | |
1511 | { | |
1512 | wait_queue_head_t *wq; | |
eaff8079 CH |
1513 | DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); |
1514 | wq = bit_waitqueue(&inode->i_state, __I_NEW); | |
1da177e4 LT |
1515 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); |
1516 | spin_unlock(&inode_lock); | |
1517 | schedule(); | |
1518 | finish_wait(wq, &wait.wait); | |
1519 | spin_lock(&inode_lock); | |
1520 | } | |
1521 | ||
1da177e4 LT |
1522 | static __initdata unsigned long ihash_entries; |
1523 | static int __init set_ihash_entries(char *str) | |
1524 | { | |
1525 | if (!str) | |
1526 | return 0; | |
1527 | ihash_entries = simple_strtoul(str, &str, 0); | |
1528 | return 1; | |
1529 | } | |
1530 | __setup("ihash_entries=", set_ihash_entries); | |
1531 | ||
1532 | /* | |
1533 | * Initialize the waitqueues and inode hash table. | |
1534 | */ | |
1535 | void __init inode_init_early(void) | |
1536 | { | |
1537 | int loop; | |
1538 | ||
1539 | /* If hashes are distributed across NUMA nodes, defer | |
1540 | * hash allocation until vmalloc space is available. | |
1541 | */ | |
1542 | if (hashdist) | |
1543 | return; | |
1544 | ||
1545 | inode_hashtable = | |
1546 | alloc_large_system_hash("Inode-cache", | |
1547 | sizeof(struct hlist_head), | |
1548 | ihash_entries, | |
1549 | 14, | |
1550 | HASH_EARLY, | |
1551 | &i_hash_shift, | |
1552 | &i_hash_mask, | |
1553 | 0); | |
1554 | ||
1555 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1556 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1557 | } | |
1558 | ||
74bf17cf | 1559 | void __init inode_init(void) |
1da177e4 LT |
1560 | { |
1561 | int loop; | |
1562 | ||
1563 | /* inode slab cache */ | |
b0196009 PJ |
1564 | inode_cachep = kmem_cache_create("inode_cache", |
1565 | sizeof(struct inode), | |
1566 | 0, | |
1567 | (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| | |
1568 | SLAB_MEM_SPREAD), | |
20c2df83 | 1569 | init_once); |
8e1f936b | 1570 | register_shrinker(&icache_shrinker); |
1da177e4 LT |
1571 | |
1572 | /* Hash may have been set up in inode_init_early */ | |
1573 | if (!hashdist) | |
1574 | return; | |
1575 | ||
1576 | inode_hashtable = | |
1577 | alloc_large_system_hash("Inode-cache", | |
1578 | sizeof(struct hlist_head), | |
1579 | ihash_entries, | |
1580 | 14, | |
1581 | 0, | |
1582 | &i_hash_shift, | |
1583 | &i_hash_mask, | |
1584 | 0); | |
1585 | ||
1586 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1587 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1588 | } | |
1589 | ||
1590 | void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) | |
1591 | { | |
1592 | inode->i_mode = mode; | |
1593 | if (S_ISCHR(mode)) { | |
1594 | inode->i_fop = &def_chr_fops; | |
1595 | inode->i_rdev = rdev; | |
1596 | } else if (S_ISBLK(mode)) { | |
1597 | inode->i_fop = &def_blk_fops; | |
1598 | inode->i_rdev = rdev; | |
1599 | } else if (S_ISFIFO(mode)) | |
1600 | inode->i_fop = &def_fifo_fops; | |
1601 | else if (S_ISSOCK(mode)) | |
1602 | inode->i_fop = &bad_sock_fops; | |
1603 | else | |
af0d9ae8 MK |
1604 | printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for" |
1605 | " inode %s:%lu\n", mode, inode->i_sb->s_id, | |
1606 | inode->i_ino); | |
1da177e4 LT |
1607 | } |
1608 | EXPORT_SYMBOL(init_special_inode); | |
a1bd120d DM |
1609 | |
1610 | /** | |
1611 | * Init uid,gid,mode for new inode according to posix standards | |
1612 | * @inode: New inode | |
1613 | * @dir: Directory inode | |
1614 | * @mode: mode of the new inode | |
1615 | */ | |
1616 | void inode_init_owner(struct inode *inode, const struct inode *dir, | |
1617 | mode_t mode) | |
1618 | { | |
1619 | inode->i_uid = current_fsuid(); | |
1620 | if (dir && dir->i_mode & S_ISGID) { | |
1621 | inode->i_gid = dir->i_gid; | |
1622 | if (S_ISDIR(mode)) | |
1623 | mode |= S_ISGID; | |
1624 | } else | |
1625 | inode->i_gid = current_fsgid(); | |
1626 | inode->i_mode = mode; | |
1627 | } | |
1628 | EXPORT_SYMBOL(inode_init_owner); |