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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 | ||
7 | #include <linux/config.h> | |
8 | #include <linux/fs.h> | |
9 | #include <linux/mm.h> | |
10 | #include <linux/dcache.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/quotaops.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/writeback.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/backing-dev.h> | |
17 | #include <linux/wait.h> | |
18 | #include <linux/hash.h> | |
19 | #include <linux/swap.h> | |
20 | #include <linux/security.h> | |
21 | #include <linux/pagemap.h> | |
22 | #include <linux/cdev.h> | |
23 | #include <linux/bootmem.h> | |
0eeca283 | 24 | #include <linux/inotify.h> |
fc33a7bb | 25 | #include <linux/mount.h> |
1da177e4 LT |
26 | |
27 | /* | |
28 | * This is needed for the following functions: | |
29 | * - inode_has_buffers | |
30 | * - invalidate_inode_buffers | |
1da177e4 LT |
31 | * - invalidate_bdev |
32 | * | |
33 | * FIXME: remove all knowledge of the buffer layer from this file | |
34 | */ | |
35 | #include <linux/buffer_head.h> | |
36 | ||
37 | /* | |
38 | * New inode.c implementation. | |
39 | * | |
40 | * This implementation has the basic premise of trying | |
41 | * to be extremely low-overhead and SMP-safe, yet be | |
42 | * simple enough to be "obviously correct". | |
43 | * | |
44 | * Famous last words. | |
45 | */ | |
46 | ||
47 | /* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */ | |
48 | ||
49 | /* #define INODE_PARANOIA 1 */ | |
50 | /* #define INODE_DEBUG 1 */ | |
51 | ||
52 | /* | |
53 | * Inode lookup is no longer as critical as it used to be: | |
54 | * most of the lookups are going to be through the dcache. | |
55 | */ | |
56 | #define I_HASHBITS i_hash_shift | |
57 | #define I_HASHMASK i_hash_mask | |
58 | ||
fa3536cc ED |
59 | static unsigned int i_hash_mask __read_mostly; |
60 | static unsigned int i_hash_shift __read_mostly; | |
1da177e4 LT |
61 | |
62 | /* | |
63 | * Each inode can be on two separate lists. One is | |
64 | * the hash list of the inode, used for lookups. The | |
65 | * other linked list is the "type" list: | |
66 | * "in_use" - valid inode, i_count > 0, i_nlink > 0 | |
67 | * "dirty" - as "in_use" but also dirty | |
68 | * "unused" - valid inode, i_count = 0 | |
69 | * | |
70 | * A "dirty" list is maintained for each super block, | |
71 | * allowing for low-overhead inode sync() operations. | |
72 | */ | |
73 | ||
74 | LIST_HEAD(inode_in_use); | |
75 | LIST_HEAD(inode_unused); | |
fa3536cc | 76 | static struct hlist_head *inode_hashtable __read_mostly; |
1da177e4 LT |
77 | |
78 | /* | |
79 | * A simple spinlock to protect the list manipulations. | |
80 | * | |
81 | * NOTE! You also have to own the lock if you change | |
82 | * the i_state of an inode while it is in use.. | |
83 | */ | |
84 | DEFINE_SPINLOCK(inode_lock); | |
85 | ||
86 | /* | |
f24075bd | 87 | * iprune_mutex provides exclusion between the kswapd or try_to_free_pages |
1da177e4 LT |
88 | * icache shrinking path, and the umount path. Without this exclusion, |
89 | * by the time prune_icache calls iput for the inode whose pages it has | |
90 | * been invalidating, or by the time it calls clear_inode & destroy_inode | |
91 | * from its final dispose_list, the struct super_block they refer to | |
92 | * (for inode->i_sb->s_op) may already have been freed and reused. | |
93 | */ | |
bdfc3266 | 94 | static DEFINE_MUTEX(iprune_mutex); |
1da177e4 LT |
95 | |
96 | /* | |
97 | * Statistics gathering.. | |
98 | */ | |
99 | struct inodes_stat_t inodes_stat; | |
100 | ||
fa3536cc | 101 | static kmem_cache_t * inode_cachep __read_mostly; |
1da177e4 LT |
102 | |
103 | static struct inode *alloc_inode(struct super_block *sb) | |
104 | { | |
105 | static struct address_space_operations empty_aops; | |
106 | static struct inode_operations empty_iops; | |
99ac48f5 | 107 | static const struct file_operations empty_fops; |
1da177e4 LT |
108 | struct inode *inode; |
109 | ||
110 | if (sb->s_op->alloc_inode) | |
111 | inode = sb->s_op->alloc_inode(sb); | |
112 | else | |
113 | inode = (struct inode *) kmem_cache_alloc(inode_cachep, SLAB_KERNEL); | |
114 | ||
115 | if (inode) { | |
116 | struct address_space * const mapping = &inode->i_data; | |
117 | ||
118 | inode->i_sb = sb; | |
119 | inode->i_blkbits = sb->s_blocksize_bits; | |
120 | inode->i_flags = 0; | |
121 | atomic_set(&inode->i_count, 1); | |
122 | inode->i_op = &empty_iops; | |
123 | inode->i_fop = &empty_fops; | |
124 | inode->i_nlink = 1; | |
125 | atomic_set(&inode->i_writecount, 0); | |
126 | inode->i_size = 0; | |
127 | inode->i_blocks = 0; | |
128 | inode->i_bytes = 0; | |
129 | inode->i_generation = 0; | |
130 | #ifdef CONFIG_QUOTA | |
131 | memset(&inode->i_dquot, 0, sizeof(inode->i_dquot)); | |
132 | #endif | |
133 | inode->i_pipe = NULL; | |
134 | inode->i_bdev = NULL; | |
135 | inode->i_cdev = NULL; | |
136 | inode->i_rdev = 0; | |
137 | inode->i_security = NULL; | |
138 | inode->dirtied_when = 0; | |
139 | if (security_inode_alloc(inode)) { | |
140 | if (inode->i_sb->s_op->destroy_inode) | |
141 | inode->i_sb->s_op->destroy_inode(inode); | |
142 | else | |
143 | kmem_cache_free(inode_cachep, (inode)); | |
144 | return NULL; | |
145 | } | |
146 | ||
147 | mapping->a_ops = &empty_aops; | |
148 | mapping->host = inode; | |
149 | mapping->flags = 0; | |
150 | mapping_set_gfp_mask(mapping, GFP_HIGHUSER); | |
151 | mapping->assoc_mapping = NULL; | |
152 | mapping->backing_dev_info = &default_backing_dev_info; | |
153 | ||
154 | /* | |
155 | * If the block_device provides a backing_dev_info for client | |
156 | * inodes then use that. Otherwise the inode share the bdev's | |
157 | * backing_dev_info. | |
158 | */ | |
159 | if (sb->s_bdev) { | |
160 | struct backing_dev_info *bdi; | |
161 | ||
162 | bdi = sb->s_bdev->bd_inode_backing_dev_info; | |
163 | if (!bdi) | |
164 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; | |
165 | mapping->backing_dev_info = bdi; | |
166 | } | |
167 | memset(&inode->u, 0, sizeof(inode->u)); | |
168 | inode->i_mapping = mapping; | |
169 | } | |
170 | return inode; | |
171 | } | |
172 | ||
173 | void destroy_inode(struct inode *inode) | |
174 | { | |
b7542f8c | 175 | BUG_ON(inode_has_buffers(inode)); |
1da177e4 LT |
176 | security_inode_free(inode); |
177 | if (inode->i_sb->s_op->destroy_inode) | |
178 | inode->i_sb->s_op->destroy_inode(inode); | |
179 | else | |
180 | kmem_cache_free(inode_cachep, (inode)); | |
181 | } | |
182 | ||
183 | ||
184 | /* | |
185 | * These are initializations that only need to be done | |
186 | * once, because the fields are idempotent across use | |
187 | * of the inode, so let the slab aware of that. | |
188 | */ | |
189 | void inode_init_once(struct inode *inode) | |
190 | { | |
191 | memset(inode, 0, sizeof(*inode)); | |
192 | INIT_HLIST_NODE(&inode->i_hash); | |
193 | INIT_LIST_HEAD(&inode->i_dentry); | |
194 | INIT_LIST_HEAD(&inode->i_devices); | |
1b1dcc1b | 195 | mutex_init(&inode->i_mutex); |
1da177e4 LT |
196 | init_rwsem(&inode->i_alloc_sem); |
197 | INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); | |
198 | rwlock_init(&inode->i_data.tree_lock); | |
199 | spin_lock_init(&inode->i_data.i_mmap_lock); | |
200 | INIT_LIST_HEAD(&inode->i_data.private_list); | |
201 | spin_lock_init(&inode->i_data.private_lock); | |
202 | INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap); | |
203 | INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); | |
204 | spin_lock_init(&inode->i_lock); | |
205 | i_size_ordered_init(inode); | |
0eeca283 RL |
206 | #ifdef CONFIG_INOTIFY |
207 | INIT_LIST_HEAD(&inode->inotify_watches); | |
d4f9af9d | 208 | mutex_init(&inode->inotify_mutex); |
0eeca283 | 209 | #endif |
1da177e4 LT |
210 | } |
211 | ||
212 | EXPORT_SYMBOL(inode_init_once); | |
213 | ||
214 | static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) | |
215 | { | |
216 | struct inode * inode = (struct inode *) foo; | |
217 | ||
218 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
219 | SLAB_CTOR_CONSTRUCTOR) | |
220 | inode_init_once(inode); | |
221 | } | |
222 | ||
223 | /* | |
224 | * inode_lock must be held | |
225 | */ | |
226 | void __iget(struct inode * inode) | |
227 | { | |
228 | if (atomic_read(&inode->i_count)) { | |
229 | atomic_inc(&inode->i_count); | |
230 | return; | |
231 | } | |
232 | atomic_inc(&inode->i_count); | |
233 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
234 | list_move(&inode->i_list, &inode_in_use); | |
235 | inodes_stat.nr_unused--; | |
236 | } | |
237 | ||
238 | /** | |
239 | * clear_inode - clear an inode | |
240 | * @inode: inode to clear | |
241 | * | |
242 | * This is called by the filesystem to tell us | |
243 | * that the inode is no longer useful. We just | |
244 | * terminate it with extreme prejudice. | |
245 | */ | |
246 | void clear_inode(struct inode *inode) | |
247 | { | |
248 | might_sleep(); | |
249 | invalidate_inode_buffers(inode); | |
250 | ||
b7542f8c ES |
251 | BUG_ON(inode->i_data.nrpages); |
252 | BUG_ON(!(inode->i_state & I_FREEING)); | |
253 | BUG_ON(inode->i_state & I_CLEAR); | |
1da177e4 LT |
254 | wait_on_inode(inode); |
255 | DQUOT_DROP(inode); | |
256 | if (inode->i_sb && inode->i_sb->s_op->clear_inode) | |
257 | inode->i_sb->s_op->clear_inode(inode); | |
258 | if (inode->i_bdev) | |
259 | bd_forget(inode); | |
260 | if (inode->i_cdev) | |
261 | cd_forget(inode); | |
262 | inode->i_state = I_CLEAR; | |
263 | } | |
264 | ||
265 | EXPORT_SYMBOL(clear_inode); | |
266 | ||
267 | /* | |
268 | * dispose_list - dispose of the contents of a local list | |
269 | * @head: the head of the list to free | |
270 | * | |
271 | * Dispose-list gets a local list with local inodes in it, so it doesn't | |
272 | * need to worry about list corruption and SMP locks. | |
273 | */ | |
274 | static void dispose_list(struct list_head *head) | |
275 | { | |
276 | int nr_disposed = 0; | |
277 | ||
278 | while (!list_empty(head)) { | |
279 | struct inode *inode; | |
280 | ||
281 | inode = list_entry(head->next, struct inode, i_list); | |
282 | list_del(&inode->i_list); | |
283 | ||
284 | if (inode->i_data.nrpages) | |
285 | truncate_inode_pages(&inode->i_data, 0); | |
286 | clear_inode(inode); | |
4120db47 AB |
287 | |
288 | spin_lock(&inode_lock); | |
289 | hlist_del_init(&inode->i_hash); | |
290 | list_del_init(&inode->i_sb_list); | |
291 | spin_unlock(&inode_lock); | |
292 | ||
293 | wake_up_inode(inode); | |
1da177e4 LT |
294 | destroy_inode(inode); |
295 | nr_disposed++; | |
296 | } | |
297 | spin_lock(&inode_lock); | |
298 | inodes_stat.nr_inodes -= nr_disposed; | |
299 | spin_unlock(&inode_lock); | |
300 | } | |
301 | ||
302 | /* | |
303 | * Invalidate all inodes for a device. | |
304 | */ | |
305 | static int invalidate_list(struct list_head *head, struct list_head *dispose) | |
306 | { | |
307 | struct list_head *next; | |
308 | int busy = 0, count = 0; | |
309 | ||
310 | next = head->next; | |
311 | for (;;) { | |
312 | struct list_head * tmp = next; | |
313 | struct inode * inode; | |
314 | ||
315 | /* | |
316 | * We can reschedule here without worrying about the list's | |
317 | * consistency because the per-sb list of inodes must not | |
f24075bd | 318 | * change during umount anymore, and because iprune_mutex keeps |
1da177e4 LT |
319 | * shrink_icache_memory() away. |
320 | */ | |
321 | cond_resched_lock(&inode_lock); | |
322 | ||
323 | next = next->next; | |
324 | if (tmp == head) | |
325 | break; | |
326 | inode = list_entry(tmp, struct inode, i_sb_list); | |
327 | invalidate_inode_buffers(inode); | |
328 | if (!atomic_read(&inode->i_count)) { | |
1da177e4 LT |
329 | list_move(&inode->i_list, dispose); |
330 | inode->i_state |= I_FREEING; | |
331 | count++; | |
332 | continue; | |
333 | } | |
334 | busy = 1; | |
335 | } | |
336 | /* only unused inodes may be cached with i_count zero */ | |
337 | inodes_stat.nr_unused -= count; | |
338 | return busy; | |
339 | } | |
340 | ||
1da177e4 LT |
341 | /** |
342 | * invalidate_inodes - discard the inodes on a device | |
343 | * @sb: superblock | |
344 | * | |
345 | * Discard all of the inodes for a given superblock. If the discard | |
346 | * fails because there are busy inodes then a non zero value is returned. | |
347 | * If the discard is successful all the inodes have been discarded. | |
348 | */ | |
349 | int invalidate_inodes(struct super_block * sb) | |
350 | { | |
351 | int busy; | |
352 | LIST_HEAD(throw_away); | |
353 | ||
f24075bd | 354 | mutex_lock(&iprune_mutex); |
1da177e4 | 355 | spin_lock(&inode_lock); |
0eeca283 | 356 | inotify_unmount_inodes(&sb->s_inodes); |
1da177e4 LT |
357 | busy = invalidate_list(&sb->s_inodes, &throw_away); |
358 | spin_unlock(&inode_lock); | |
359 | ||
360 | dispose_list(&throw_away); | |
f24075bd | 361 | mutex_unlock(&iprune_mutex); |
1da177e4 LT |
362 | |
363 | return busy; | |
364 | } | |
365 | ||
366 | EXPORT_SYMBOL(invalidate_inodes); | |
367 | ||
2ef41634 | 368 | int __invalidate_device(struct block_device *bdev) |
1da177e4 | 369 | { |
2ef41634 CH |
370 | struct super_block *sb = get_super(bdev); |
371 | int res = 0; | |
1da177e4 | 372 | |
1da177e4 LT |
373 | if (sb) { |
374 | /* | |
375 | * no need to lock the super, get_super holds the | |
f24075bd | 376 | * read mutex so the filesystem cannot go away |
1da177e4 LT |
377 | * under us (->put_super runs with the write lock |
378 | * hold). | |
379 | */ | |
380 | shrink_dcache_sb(sb); | |
381 | res = invalidate_inodes(sb); | |
382 | drop_super(sb); | |
383 | } | |
384 | invalidate_bdev(bdev, 0); | |
385 | return res; | |
386 | } | |
1da177e4 LT |
387 | EXPORT_SYMBOL(__invalidate_device); |
388 | ||
389 | static int can_unuse(struct inode *inode) | |
390 | { | |
391 | if (inode->i_state) | |
392 | return 0; | |
393 | if (inode_has_buffers(inode)) | |
394 | return 0; | |
395 | if (atomic_read(&inode->i_count)) | |
396 | return 0; | |
397 | if (inode->i_data.nrpages) | |
398 | return 0; | |
399 | return 1; | |
400 | } | |
401 | ||
402 | /* | |
403 | * Scan `goal' inodes on the unused list for freeable ones. They are moved to | |
404 | * a temporary list and then are freed outside inode_lock by dispose_list(). | |
405 | * | |
406 | * Any inodes which are pinned purely because of attached pagecache have their | |
407 | * pagecache removed. We expect the final iput() on that inode to add it to | |
408 | * the front of the inode_unused list. So look for it there and if the | |
409 | * inode is still freeable, proceed. The right inode is found 99.9% of the | |
410 | * time in testing on a 4-way. | |
411 | * | |
412 | * If the inode has metadata buffers attached to mapping->private_list then | |
413 | * try to remove them. | |
414 | */ | |
415 | static void prune_icache(int nr_to_scan) | |
416 | { | |
417 | LIST_HEAD(freeable); | |
418 | int nr_pruned = 0; | |
419 | int nr_scanned; | |
420 | unsigned long reap = 0; | |
421 | ||
f24075bd | 422 | mutex_lock(&iprune_mutex); |
1da177e4 LT |
423 | spin_lock(&inode_lock); |
424 | for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { | |
425 | struct inode *inode; | |
426 | ||
427 | if (list_empty(&inode_unused)) | |
428 | break; | |
429 | ||
430 | inode = list_entry(inode_unused.prev, struct inode, i_list); | |
431 | ||
432 | if (inode->i_state || atomic_read(&inode->i_count)) { | |
433 | list_move(&inode->i_list, &inode_unused); | |
434 | continue; | |
435 | } | |
436 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { | |
437 | __iget(inode); | |
438 | spin_unlock(&inode_lock); | |
439 | if (remove_inode_buffers(inode)) | |
440 | reap += invalidate_inode_pages(&inode->i_data); | |
441 | iput(inode); | |
442 | spin_lock(&inode_lock); | |
443 | ||
444 | if (inode != list_entry(inode_unused.next, | |
445 | struct inode, i_list)) | |
446 | continue; /* wrong inode or list_empty */ | |
447 | if (!can_unuse(inode)) | |
448 | continue; | |
449 | } | |
1da177e4 LT |
450 | list_move(&inode->i_list, &freeable); |
451 | inode->i_state |= I_FREEING; | |
452 | nr_pruned++; | |
453 | } | |
454 | inodes_stat.nr_unused -= nr_pruned; | |
455 | spin_unlock(&inode_lock); | |
456 | ||
457 | dispose_list(&freeable); | |
f24075bd | 458 | mutex_unlock(&iprune_mutex); |
1da177e4 LT |
459 | |
460 | if (current_is_kswapd()) | |
461 | mod_page_state(kswapd_inodesteal, reap); | |
462 | else | |
463 | mod_page_state(pginodesteal, reap); | |
464 | } | |
465 | ||
466 | /* | |
467 | * shrink_icache_memory() will attempt to reclaim some unused inodes. Here, | |
468 | * "unused" means that no dentries are referring to the inodes: the files are | |
469 | * not open and the dcache references to those inodes have already been | |
470 | * reclaimed. | |
471 | * | |
472 | * This function is passed the number of inodes to scan, and it returns the | |
473 | * total number of remaining possibly-reclaimable inodes. | |
474 | */ | |
27496a8c | 475 | static int shrink_icache_memory(int nr, gfp_t gfp_mask) |
1da177e4 LT |
476 | { |
477 | if (nr) { | |
478 | /* | |
479 | * Nasty deadlock avoidance. We may hold various FS locks, | |
480 | * and we don't want to recurse into the FS that called us | |
481 | * in clear_inode() and friends.. | |
482 | */ | |
483 | if (!(gfp_mask & __GFP_FS)) | |
484 | return -1; | |
485 | prune_icache(nr); | |
486 | } | |
487 | return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure; | |
488 | } | |
489 | ||
490 | static void __wait_on_freeing_inode(struct inode *inode); | |
491 | /* | |
492 | * Called with the inode lock held. | |
493 | * NOTE: we are not increasing the inode-refcount, you must call __iget() | |
494 | * by hand after calling find_inode now! This simplifies iunique and won't | |
495 | * add any additional branch in the common code. | |
496 | */ | |
497 | static struct inode * find_inode(struct super_block * sb, struct hlist_head *head, int (*test)(struct inode *, void *), void *data) | |
498 | { | |
499 | struct hlist_node *node; | |
500 | struct inode * inode = NULL; | |
501 | ||
502 | repeat: | |
503 | hlist_for_each (node, head) { | |
504 | inode = hlist_entry(node, struct inode, i_hash); | |
505 | if (inode->i_sb != sb) | |
506 | continue; | |
507 | if (!test(inode, data)) | |
508 | continue; | |
991114c6 | 509 | if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { |
1da177e4 LT |
510 | __wait_on_freeing_inode(inode); |
511 | goto repeat; | |
512 | } | |
513 | break; | |
514 | } | |
515 | return node ? inode : NULL; | |
516 | } | |
517 | ||
518 | /* | |
519 | * find_inode_fast is the fast path version of find_inode, see the comment at | |
520 | * iget_locked for details. | |
521 | */ | |
522 | static struct inode * find_inode_fast(struct super_block * sb, struct hlist_head *head, unsigned long ino) | |
523 | { | |
524 | struct hlist_node *node; | |
525 | struct inode * inode = NULL; | |
526 | ||
527 | repeat: | |
528 | hlist_for_each (node, head) { | |
529 | inode = hlist_entry(node, struct inode, i_hash); | |
530 | if (inode->i_ino != ino) | |
531 | continue; | |
532 | if (inode->i_sb != sb) | |
533 | continue; | |
991114c6 | 534 | if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { |
1da177e4 LT |
535 | __wait_on_freeing_inode(inode); |
536 | goto repeat; | |
537 | } | |
538 | break; | |
539 | } | |
540 | return node ? inode : NULL; | |
541 | } | |
542 | ||
543 | /** | |
544 | * new_inode - obtain an inode | |
545 | * @sb: superblock | |
546 | * | |
547 | * Allocates a new inode for given superblock. | |
548 | */ | |
549 | struct inode *new_inode(struct super_block *sb) | |
550 | { | |
551 | static unsigned long last_ino; | |
552 | struct inode * inode; | |
553 | ||
554 | spin_lock_prefetch(&inode_lock); | |
555 | ||
556 | inode = alloc_inode(sb); | |
557 | if (inode) { | |
558 | spin_lock(&inode_lock); | |
559 | inodes_stat.nr_inodes++; | |
560 | list_add(&inode->i_list, &inode_in_use); | |
561 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
562 | inode->i_ino = ++last_ino; | |
563 | inode->i_state = 0; | |
564 | spin_unlock(&inode_lock); | |
565 | } | |
566 | return inode; | |
567 | } | |
568 | ||
569 | EXPORT_SYMBOL(new_inode); | |
570 | ||
571 | void unlock_new_inode(struct inode *inode) | |
572 | { | |
573 | /* | |
574 | * This is special! We do not need the spinlock | |
575 | * when clearing I_LOCK, because we're guaranteed | |
576 | * that nobody else tries to do anything about the | |
577 | * state of the inode when it is locked, as we | |
578 | * just created it (so there can be no old holders | |
579 | * that haven't tested I_LOCK). | |
580 | */ | |
581 | inode->i_state &= ~(I_LOCK|I_NEW); | |
582 | wake_up_inode(inode); | |
583 | } | |
584 | ||
585 | EXPORT_SYMBOL(unlock_new_inode); | |
586 | ||
587 | /* | |
588 | * This is called without the inode lock held.. Be careful. | |
589 | * | |
590 | * We no longer cache the sb_flags in i_flags - see fs.h | |
591 | * -- rmk@arm.uk.linux.org | |
592 | */ | |
593 | static struct inode * get_new_inode(struct super_block *sb, struct hlist_head *head, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *data) | |
594 | { | |
595 | struct inode * inode; | |
596 | ||
597 | inode = alloc_inode(sb); | |
598 | if (inode) { | |
599 | struct inode * old; | |
600 | ||
601 | spin_lock(&inode_lock); | |
602 | /* We released the lock, so.. */ | |
603 | old = find_inode(sb, head, test, data); | |
604 | if (!old) { | |
605 | if (set(inode, data)) | |
606 | goto set_failed; | |
607 | ||
608 | inodes_stat.nr_inodes++; | |
609 | list_add(&inode->i_list, &inode_in_use); | |
610 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
611 | hlist_add_head(&inode->i_hash, head); | |
612 | inode->i_state = I_LOCK|I_NEW; | |
613 | spin_unlock(&inode_lock); | |
614 | ||
615 | /* Return the locked inode with I_NEW set, the | |
616 | * caller is responsible for filling in the contents | |
617 | */ | |
618 | return inode; | |
619 | } | |
620 | ||
621 | /* | |
622 | * Uhhuh, somebody else created the same inode under | |
623 | * us. Use the old inode instead of the one we just | |
624 | * allocated. | |
625 | */ | |
626 | __iget(old); | |
627 | spin_unlock(&inode_lock); | |
628 | destroy_inode(inode); | |
629 | inode = old; | |
630 | wait_on_inode(inode); | |
631 | } | |
632 | return inode; | |
633 | ||
634 | set_failed: | |
635 | spin_unlock(&inode_lock); | |
636 | destroy_inode(inode); | |
637 | return NULL; | |
638 | } | |
639 | ||
640 | /* | |
641 | * get_new_inode_fast is the fast path version of get_new_inode, see the | |
642 | * comment at iget_locked for details. | |
643 | */ | |
644 | static struct inode * get_new_inode_fast(struct super_block *sb, struct hlist_head *head, unsigned long ino) | |
645 | { | |
646 | struct inode * inode; | |
647 | ||
648 | inode = alloc_inode(sb); | |
649 | if (inode) { | |
650 | struct inode * old; | |
651 | ||
652 | spin_lock(&inode_lock); | |
653 | /* We released the lock, so.. */ | |
654 | old = find_inode_fast(sb, head, ino); | |
655 | if (!old) { | |
656 | inode->i_ino = ino; | |
657 | inodes_stat.nr_inodes++; | |
658 | list_add(&inode->i_list, &inode_in_use); | |
659 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
660 | hlist_add_head(&inode->i_hash, head); | |
661 | inode->i_state = I_LOCK|I_NEW; | |
662 | spin_unlock(&inode_lock); | |
663 | ||
664 | /* Return the locked inode with I_NEW set, the | |
665 | * caller is responsible for filling in the contents | |
666 | */ | |
667 | return inode; | |
668 | } | |
669 | ||
670 | /* | |
671 | * Uhhuh, somebody else created the same inode under | |
672 | * us. Use the old inode instead of the one we just | |
673 | * allocated. | |
674 | */ | |
675 | __iget(old); | |
676 | spin_unlock(&inode_lock); | |
677 | destroy_inode(inode); | |
678 | inode = old; | |
679 | wait_on_inode(inode); | |
680 | } | |
681 | return inode; | |
682 | } | |
683 | ||
684 | static inline unsigned long hash(struct super_block *sb, unsigned long hashval) | |
685 | { | |
686 | unsigned long tmp; | |
687 | ||
688 | tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / | |
689 | L1_CACHE_BYTES; | |
690 | tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS); | |
691 | return tmp & I_HASHMASK; | |
692 | } | |
693 | ||
694 | /** | |
695 | * iunique - get a unique inode number | |
696 | * @sb: superblock | |
697 | * @max_reserved: highest reserved inode number | |
698 | * | |
699 | * Obtain an inode number that is unique on the system for a given | |
700 | * superblock. This is used by file systems that have no natural | |
701 | * permanent inode numbering system. An inode number is returned that | |
702 | * is higher than the reserved limit but unique. | |
703 | * | |
704 | * BUGS: | |
705 | * With a large number of inodes live on the file system this function | |
706 | * currently becomes quite slow. | |
707 | */ | |
708 | ino_t iunique(struct super_block *sb, ino_t max_reserved) | |
709 | { | |
710 | static ino_t counter; | |
711 | struct inode *inode; | |
712 | struct hlist_head * head; | |
713 | ino_t res; | |
714 | spin_lock(&inode_lock); | |
715 | retry: | |
716 | if (counter > max_reserved) { | |
717 | head = inode_hashtable + hash(sb,counter); | |
718 | res = counter++; | |
719 | inode = find_inode_fast(sb, head, res); | |
720 | if (!inode) { | |
721 | spin_unlock(&inode_lock); | |
722 | return res; | |
723 | } | |
724 | } else { | |
725 | counter = max_reserved + 1; | |
726 | } | |
727 | goto retry; | |
728 | ||
729 | } | |
730 | ||
731 | EXPORT_SYMBOL(iunique); | |
732 | ||
733 | struct inode *igrab(struct inode *inode) | |
734 | { | |
735 | spin_lock(&inode_lock); | |
991114c6 | 736 | if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) |
1da177e4 LT |
737 | __iget(inode); |
738 | else | |
739 | /* | |
740 | * Handle the case where s_op->clear_inode is not been | |
741 | * called yet, and somebody is calling igrab | |
742 | * while the inode is getting freed. | |
743 | */ | |
744 | inode = NULL; | |
745 | spin_unlock(&inode_lock); | |
746 | return inode; | |
747 | } | |
748 | ||
749 | EXPORT_SYMBOL(igrab); | |
750 | ||
751 | /** | |
752 | * ifind - internal function, you want ilookup5() or iget5(). | |
753 | * @sb: super block of file system to search | |
754 | * @head: the head of the list to search | |
755 | * @test: callback used for comparisons between inodes | |
756 | * @data: opaque data pointer to pass to @test | |
88bd5121 | 757 | * @wait: if true wait for the inode to be unlocked, if false do not |
1da177e4 LT |
758 | * |
759 | * ifind() searches for the inode specified by @data in the inode | |
760 | * cache. This is a generalized version of ifind_fast() for file systems where | |
761 | * the inode number is not sufficient for unique identification of an inode. | |
762 | * | |
763 | * If the inode is in the cache, the inode is returned with an incremented | |
764 | * reference count. | |
765 | * | |
766 | * Otherwise NULL is returned. | |
767 | * | |
768 | * Note, @test is called with the inode_lock held, so can't sleep. | |
769 | */ | |
5d2bea45 | 770 | static struct inode *ifind(struct super_block *sb, |
1da177e4 | 771 | struct hlist_head *head, int (*test)(struct inode *, void *), |
88bd5121 | 772 | void *data, const int wait) |
1da177e4 LT |
773 | { |
774 | struct inode *inode; | |
775 | ||
776 | spin_lock(&inode_lock); | |
777 | inode = find_inode(sb, head, test, data); | |
778 | if (inode) { | |
779 | __iget(inode); | |
780 | spin_unlock(&inode_lock); | |
88bd5121 AA |
781 | if (likely(wait)) |
782 | wait_on_inode(inode); | |
1da177e4 LT |
783 | return inode; |
784 | } | |
785 | spin_unlock(&inode_lock); | |
786 | return NULL; | |
787 | } | |
788 | ||
789 | /** | |
790 | * ifind_fast - internal function, you want ilookup() or iget(). | |
791 | * @sb: super block of file system to search | |
792 | * @head: head of the list to search | |
793 | * @ino: inode number to search for | |
794 | * | |
795 | * ifind_fast() searches for the inode @ino in the inode cache. This is for | |
796 | * file systems where the inode number is sufficient for unique identification | |
797 | * of an inode. | |
798 | * | |
799 | * If the inode is in the cache, the inode is returned with an incremented | |
800 | * reference count. | |
801 | * | |
802 | * Otherwise NULL is returned. | |
803 | */ | |
5d2bea45 | 804 | static struct inode *ifind_fast(struct super_block *sb, |
1da177e4 LT |
805 | struct hlist_head *head, unsigned long ino) |
806 | { | |
807 | struct inode *inode; | |
808 | ||
809 | spin_lock(&inode_lock); | |
810 | inode = find_inode_fast(sb, head, ino); | |
811 | if (inode) { | |
812 | __iget(inode); | |
813 | spin_unlock(&inode_lock); | |
814 | wait_on_inode(inode); | |
815 | return inode; | |
816 | } | |
817 | spin_unlock(&inode_lock); | |
818 | return NULL; | |
819 | } | |
820 | ||
821 | /** | |
88bd5121 | 822 | * ilookup5_nowait - search for an inode in the inode cache |
1da177e4 LT |
823 | * @sb: super block of file system to search |
824 | * @hashval: hash value (usually inode number) to search for | |
825 | * @test: callback used for comparisons between inodes | |
826 | * @data: opaque data pointer to pass to @test | |
827 | * | |
828 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
829 | * @data in the inode cache. This is a generalized version of ilookup() for | |
830 | * file systems where the inode number is not sufficient for unique | |
831 | * identification of an inode. | |
832 | * | |
833 | * If the inode is in the cache, the inode is returned with an incremented | |
88bd5121 AA |
834 | * reference count. Note, the inode lock is not waited upon so you have to be |
835 | * very careful what you do with the returned inode. You probably should be | |
836 | * using ilookup5() instead. | |
837 | * | |
838 | * Otherwise NULL is returned. | |
839 | * | |
840 | * Note, @test is called with the inode_lock held, so can't sleep. | |
841 | */ | |
842 | struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, | |
843 | int (*test)(struct inode *, void *), void *data) | |
844 | { | |
845 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
846 | ||
847 | return ifind(sb, head, test, data, 0); | |
848 | } | |
849 | ||
850 | EXPORT_SYMBOL(ilookup5_nowait); | |
851 | ||
852 | /** | |
853 | * ilookup5 - search for an inode in the inode cache | |
854 | * @sb: super block of file system to search | |
855 | * @hashval: hash value (usually inode number) to search for | |
856 | * @test: callback used for comparisons between inodes | |
857 | * @data: opaque data pointer to pass to @test | |
858 | * | |
859 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
860 | * @data in the inode cache. This is a generalized version of ilookup() for | |
861 | * file systems where the inode number is not sufficient for unique | |
862 | * identification of an inode. | |
863 | * | |
864 | * If the inode is in the cache, the inode lock is waited upon and the inode is | |
865 | * returned with an incremented reference count. | |
1da177e4 LT |
866 | * |
867 | * Otherwise NULL is returned. | |
868 | * | |
869 | * Note, @test is called with the inode_lock held, so can't sleep. | |
870 | */ | |
871 | struct inode *ilookup5(struct super_block *sb, unsigned long hashval, | |
872 | int (*test)(struct inode *, void *), void *data) | |
873 | { | |
874 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
875 | ||
88bd5121 | 876 | return ifind(sb, head, test, data, 1); |
1da177e4 LT |
877 | } |
878 | ||
879 | EXPORT_SYMBOL(ilookup5); | |
880 | ||
881 | /** | |
882 | * ilookup - search for an inode in the inode cache | |
883 | * @sb: super block of file system to search | |
884 | * @ino: inode number to search for | |
885 | * | |
886 | * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache. | |
887 | * This is for file systems where the inode number is sufficient for unique | |
888 | * identification of an inode. | |
889 | * | |
890 | * If the inode is in the cache, the inode is returned with an incremented | |
891 | * reference count. | |
892 | * | |
893 | * Otherwise NULL is returned. | |
894 | */ | |
895 | struct inode *ilookup(struct super_block *sb, unsigned long ino) | |
896 | { | |
897 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
898 | ||
899 | return ifind_fast(sb, head, ino); | |
900 | } | |
901 | ||
902 | EXPORT_SYMBOL(ilookup); | |
903 | ||
904 | /** | |
905 | * iget5_locked - obtain an inode from a mounted file system | |
906 | * @sb: super block of file system | |
907 | * @hashval: hash value (usually inode number) to get | |
908 | * @test: callback used for comparisons between inodes | |
909 | * @set: callback used to initialize a new struct inode | |
910 | * @data: opaque data pointer to pass to @test and @set | |
911 | * | |
912 | * This is iget() without the read_inode() portion of get_new_inode(). | |
913 | * | |
914 | * iget5_locked() uses ifind() to search for the inode specified by @hashval | |
915 | * and @data in the inode cache and if present it is returned with an increased | |
916 | * reference count. This is a generalized version of iget_locked() for file | |
917 | * systems where the inode number is not sufficient for unique identification | |
918 | * of an inode. | |
919 | * | |
920 | * If the inode is not in cache, get_new_inode() is called to allocate a new | |
921 | * inode and this is returned locked, hashed, and with the I_NEW flag set. The | |
922 | * file system gets to fill it in before unlocking it via unlock_new_inode(). | |
923 | * | |
924 | * Note both @test and @set are called with the inode_lock held, so can't sleep. | |
925 | */ | |
926 | struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, | |
927 | int (*test)(struct inode *, void *), | |
928 | int (*set)(struct inode *, void *), void *data) | |
929 | { | |
930 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
931 | struct inode *inode; | |
932 | ||
88bd5121 | 933 | inode = ifind(sb, head, test, data, 1); |
1da177e4 LT |
934 | if (inode) |
935 | return inode; | |
936 | /* | |
937 | * get_new_inode() will do the right thing, re-trying the search | |
938 | * in case it had to block at any point. | |
939 | */ | |
940 | return get_new_inode(sb, head, test, set, data); | |
941 | } | |
942 | ||
943 | EXPORT_SYMBOL(iget5_locked); | |
944 | ||
945 | /** | |
946 | * iget_locked - obtain an inode from a mounted file system | |
947 | * @sb: super block of file system | |
948 | * @ino: inode number to get | |
949 | * | |
950 | * This is iget() without the read_inode() portion of get_new_inode_fast(). | |
951 | * | |
952 | * iget_locked() uses ifind_fast() to search for the inode specified by @ino in | |
953 | * the inode cache and if present it is returned with an increased reference | |
954 | * count. This is for file systems where the inode number is sufficient for | |
955 | * unique identification of an inode. | |
956 | * | |
957 | * If the inode is not in cache, get_new_inode_fast() is called to allocate a | |
958 | * new inode and this is returned locked, hashed, and with the I_NEW flag set. | |
959 | * The file system gets to fill it in before unlocking it via | |
960 | * unlock_new_inode(). | |
961 | */ | |
962 | struct inode *iget_locked(struct super_block *sb, unsigned long ino) | |
963 | { | |
964 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
965 | struct inode *inode; | |
966 | ||
967 | inode = ifind_fast(sb, head, ino); | |
968 | if (inode) | |
969 | return inode; | |
970 | /* | |
971 | * get_new_inode_fast() will do the right thing, re-trying the search | |
972 | * in case it had to block at any point. | |
973 | */ | |
974 | return get_new_inode_fast(sb, head, ino); | |
975 | } | |
976 | ||
977 | EXPORT_SYMBOL(iget_locked); | |
978 | ||
979 | /** | |
980 | * __insert_inode_hash - hash an inode | |
981 | * @inode: unhashed inode | |
982 | * @hashval: unsigned long value used to locate this object in the | |
983 | * inode_hashtable. | |
984 | * | |
985 | * Add an inode to the inode hash for this superblock. | |
986 | */ | |
987 | void __insert_inode_hash(struct inode *inode, unsigned long hashval) | |
988 | { | |
989 | struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval); | |
990 | spin_lock(&inode_lock); | |
991 | hlist_add_head(&inode->i_hash, head); | |
992 | spin_unlock(&inode_lock); | |
993 | } | |
994 | ||
995 | EXPORT_SYMBOL(__insert_inode_hash); | |
996 | ||
997 | /** | |
998 | * remove_inode_hash - remove an inode from the hash | |
999 | * @inode: inode to unhash | |
1000 | * | |
1001 | * Remove an inode from the superblock. | |
1002 | */ | |
1003 | void remove_inode_hash(struct inode *inode) | |
1004 | { | |
1005 | spin_lock(&inode_lock); | |
1006 | hlist_del_init(&inode->i_hash); | |
1007 | spin_unlock(&inode_lock); | |
1008 | } | |
1009 | ||
1010 | EXPORT_SYMBOL(remove_inode_hash); | |
1011 | ||
1012 | /* | |
1013 | * Tell the filesystem that this inode is no longer of any interest and should | |
1014 | * be completely destroyed. | |
1015 | * | |
1016 | * We leave the inode in the inode hash table until *after* the filesystem's | |
1017 | * ->delete_inode completes. This ensures that an iget (such as nfsd might | |
1018 | * instigate) will always find up-to-date information either in the hash or on | |
1019 | * disk. | |
1020 | * | |
1021 | * I_FREEING is set so that no-one will take a new reference to the inode while | |
1022 | * it is being deleted. | |
1023 | */ | |
1024 | void generic_delete_inode(struct inode *inode) | |
1025 | { | |
1026 | struct super_operations *op = inode->i_sb->s_op; | |
1027 | ||
1028 | list_del_init(&inode->i_list); | |
1029 | list_del_init(&inode->i_sb_list); | |
1030 | inode->i_state|=I_FREEING; | |
1031 | inodes_stat.nr_inodes--; | |
1032 | spin_unlock(&inode_lock); | |
1033 | ||
1da177e4 LT |
1034 | security_inode_delete(inode); |
1035 | ||
1036 | if (op->delete_inode) { | |
1037 | void (*delete)(struct inode *) = op->delete_inode; | |
1038 | if (!is_bad_inode(inode)) | |
1039 | DQUOT_INIT(inode); | |
e85b5652 MF |
1040 | /* Filesystems implementing their own |
1041 | * s_op->delete_inode are required to call | |
1042 | * truncate_inode_pages and clear_inode() | |
1043 | * internally */ | |
1da177e4 | 1044 | delete(inode); |
e85b5652 MF |
1045 | } else { |
1046 | truncate_inode_pages(&inode->i_data, 0); | |
1da177e4 | 1047 | clear_inode(inode); |
e85b5652 | 1048 | } |
1da177e4 LT |
1049 | spin_lock(&inode_lock); |
1050 | hlist_del_init(&inode->i_hash); | |
1051 | spin_unlock(&inode_lock); | |
1052 | wake_up_inode(inode); | |
b7542f8c | 1053 | BUG_ON(inode->i_state != I_CLEAR); |
1da177e4 LT |
1054 | destroy_inode(inode); |
1055 | } | |
1056 | ||
1057 | EXPORT_SYMBOL(generic_delete_inode); | |
1058 | ||
1059 | static void generic_forget_inode(struct inode *inode) | |
1060 | { | |
1061 | struct super_block *sb = inode->i_sb; | |
1062 | ||
1063 | if (!hlist_unhashed(&inode->i_hash)) { | |
1064 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
1065 | list_move(&inode->i_list, &inode_unused); | |
1066 | inodes_stat.nr_unused++; | |
991114c6 AV |
1067 | if (!sb || (sb->s_flags & MS_ACTIVE)) { |
1068 | spin_unlock(&inode_lock); | |
1da177e4 | 1069 | return; |
991114c6 AV |
1070 | } |
1071 | inode->i_state |= I_WILL_FREE; | |
1072 | spin_unlock(&inode_lock); | |
1da177e4 LT |
1073 | write_inode_now(inode, 1); |
1074 | spin_lock(&inode_lock); | |
991114c6 | 1075 | inode->i_state &= ~I_WILL_FREE; |
1da177e4 LT |
1076 | inodes_stat.nr_unused--; |
1077 | hlist_del_init(&inode->i_hash); | |
1078 | } | |
1079 | list_del_init(&inode->i_list); | |
1080 | list_del_init(&inode->i_sb_list); | |
991114c6 | 1081 | inode->i_state |= I_FREEING; |
1da177e4 LT |
1082 | inodes_stat.nr_inodes--; |
1083 | spin_unlock(&inode_lock); | |
1084 | if (inode->i_data.nrpages) | |
1085 | truncate_inode_pages(&inode->i_data, 0); | |
1086 | clear_inode(inode); | |
7f04c26d | 1087 | wake_up_inode(inode); |
1da177e4 LT |
1088 | destroy_inode(inode); |
1089 | } | |
1090 | ||
1091 | /* | |
1092 | * Normal UNIX filesystem behaviour: delete the | |
1093 | * inode when the usage count drops to zero, and | |
1094 | * i_nlink is zero. | |
1095 | */ | |
cb2c0233 | 1096 | void generic_drop_inode(struct inode *inode) |
1da177e4 LT |
1097 | { |
1098 | if (!inode->i_nlink) | |
1099 | generic_delete_inode(inode); | |
1100 | else | |
1101 | generic_forget_inode(inode); | |
1102 | } | |
1103 | ||
cb2c0233 MF |
1104 | EXPORT_SYMBOL_GPL(generic_drop_inode); |
1105 | ||
1da177e4 LT |
1106 | /* |
1107 | * Called when we're dropping the last reference | |
1108 | * to an inode. | |
1109 | * | |
1110 | * Call the FS "drop()" function, defaulting to | |
1111 | * the legacy UNIX filesystem behaviour.. | |
1112 | * | |
1113 | * NOTE! NOTE! NOTE! We're called with the inode lock | |
1114 | * held, and the drop function is supposed to release | |
1115 | * the lock! | |
1116 | */ | |
1117 | static inline void iput_final(struct inode *inode) | |
1118 | { | |
1119 | struct super_operations *op = inode->i_sb->s_op; | |
1120 | void (*drop)(struct inode *) = generic_drop_inode; | |
1121 | ||
1122 | if (op && op->drop_inode) | |
1123 | drop = op->drop_inode; | |
1124 | drop(inode); | |
1125 | } | |
1126 | ||
1127 | /** | |
1128 | * iput - put an inode | |
1129 | * @inode: inode to put | |
1130 | * | |
1131 | * Puts an inode, dropping its usage count. If the inode use count hits | |
1132 | * zero, the inode is then freed and may also be destroyed. | |
1133 | * | |
1134 | * Consequently, iput() can sleep. | |
1135 | */ | |
1136 | void iput(struct inode *inode) | |
1137 | { | |
1138 | if (inode) { | |
1139 | struct super_operations *op = inode->i_sb->s_op; | |
1140 | ||
1141 | BUG_ON(inode->i_state == I_CLEAR); | |
1142 | ||
1143 | if (op && op->put_inode) | |
1144 | op->put_inode(inode); | |
1145 | ||
1146 | if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) | |
1147 | iput_final(inode); | |
1148 | } | |
1149 | } | |
1150 | ||
1151 | EXPORT_SYMBOL(iput); | |
1152 | ||
1153 | /** | |
1154 | * bmap - find a block number in a file | |
1155 | * @inode: inode of file | |
1156 | * @block: block to find | |
1157 | * | |
1158 | * Returns the block number on the device holding the inode that | |
1159 | * is the disk block number for the block of the file requested. | |
1160 | * That is, asked for block 4 of inode 1 the function will return the | |
1161 | * disk block relative to the disk start that holds that block of the | |
1162 | * file. | |
1163 | */ | |
1164 | sector_t bmap(struct inode * inode, sector_t block) | |
1165 | { | |
1166 | sector_t res = 0; | |
1167 | if (inode->i_mapping->a_ops->bmap) | |
1168 | res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); | |
1169 | return res; | |
1170 | } | |
1171 | ||
1172 | EXPORT_SYMBOL(bmap); | |
1173 | ||
1174 | /** | |
869243a0 CH |
1175 | * touch_atime - update the access time |
1176 | * @mnt: mount the inode is accessed on | |
7045f37b | 1177 | * @dentry: dentry accessed |
1da177e4 LT |
1178 | * |
1179 | * Update the accessed time on an inode and mark it for writeback. | |
1180 | * This function automatically handles read only file systems and media, | |
1181 | * as well as the "noatime" flag and inode specific "noatime" markers. | |
1182 | */ | |
869243a0 | 1183 | void touch_atime(struct vfsmount *mnt, struct dentry *dentry) |
1da177e4 | 1184 | { |
869243a0 | 1185 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
1186 | struct timespec now; |
1187 | ||
fc33a7bb | 1188 | if (IS_RDONLY(inode)) |
1da177e4 | 1189 | return; |
fc33a7bb CH |
1190 | |
1191 | if ((inode->i_flags & S_NOATIME) || | |
1192 | (inode->i_sb->s_flags & MS_NOATIME) || | |
1193 | ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))) | |
1da177e4 | 1194 | return; |
fc33a7bb CH |
1195 | |
1196 | /* | |
1197 | * We may have a NULL vfsmount when coming from NFSD | |
1198 | */ | |
1199 | if (mnt && | |
1200 | ((mnt->mnt_flags & MNT_NOATIME) || | |
1201 | ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))) | |
1da177e4 LT |
1202 | return; |
1203 | ||
1204 | now = current_fs_time(inode->i_sb); | |
1205 | if (!timespec_equal(&inode->i_atime, &now)) { | |
1206 | inode->i_atime = now; | |
1207 | mark_inode_dirty_sync(inode); | |
1da177e4 LT |
1208 | } |
1209 | } | |
1210 | ||
869243a0 | 1211 | EXPORT_SYMBOL(touch_atime); |
1da177e4 LT |
1212 | |
1213 | /** | |
870f4817 CH |
1214 | * file_update_time - update mtime and ctime time |
1215 | * @file: file accessed | |
1da177e4 | 1216 | * |
870f4817 CH |
1217 | * Update the mtime and ctime members of an inode and mark the inode |
1218 | * for writeback. Note that this function is meant exclusively for | |
1219 | * usage in the file write path of filesystems, and filesystems may | |
1220 | * choose to explicitly ignore update via this function with the | |
1221 | * S_NOCTIME inode flag, e.g. for network filesystem where these | |
1222 | * timestamps are handled by the server. | |
1da177e4 LT |
1223 | */ |
1224 | ||
870f4817 | 1225 | void file_update_time(struct file *file) |
1da177e4 | 1226 | { |
870f4817 | 1227 | struct inode *inode = file->f_dentry->d_inode; |
1da177e4 LT |
1228 | struct timespec now; |
1229 | int sync_it = 0; | |
1230 | ||
1231 | if (IS_NOCMTIME(inode)) | |
1232 | return; | |
1233 | if (IS_RDONLY(inode)) | |
1234 | return; | |
1235 | ||
1236 | now = current_fs_time(inode->i_sb); | |
1237 | if (!timespec_equal(&inode->i_mtime, &now)) | |
1238 | sync_it = 1; | |
1239 | inode->i_mtime = now; | |
1240 | ||
870f4817 CH |
1241 | if (!timespec_equal(&inode->i_ctime, &now)) |
1242 | sync_it = 1; | |
1243 | inode->i_ctime = now; | |
1244 | ||
1da177e4 LT |
1245 | if (sync_it) |
1246 | mark_inode_dirty_sync(inode); | |
1247 | } | |
1248 | ||
870f4817 | 1249 | EXPORT_SYMBOL(file_update_time); |
1da177e4 LT |
1250 | |
1251 | int inode_needs_sync(struct inode *inode) | |
1252 | { | |
1253 | if (IS_SYNC(inode)) | |
1254 | return 1; | |
1255 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) | |
1256 | return 1; | |
1257 | return 0; | |
1258 | } | |
1259 | ||
1260 | EXPORT_SYMBOL(inode_needs_sync); | |
1261 | ||
1262 | /* | |
1263 | * Quota functions that want to walk the inode lists.. | |
1264 | */ | |
1265 | #ifdef CONFIG_QUOTA | |
1266 | ||
1267 | /* Function back in dquot.c */ | |
1268 | int remove_inode_dquot_ref(struct inode *, int, struct list_head *); | |
1269 | ||
1270 | void remove_dquot_ref(struct super_block *sb, int type, | |
1271 | struct list_head *tofree_head) | |
1272 | { | |
1273 | struct inode *inode; | |
1274 | ||
1275 | if (!sb->dq_op) | |
1276 | return; /* nothing to do */ | |
1277 | spin_lock(&inode_lock); /* This lock is for inodes code */ | |
1278 | ||
1279 | /* | |
1280 | * We don't have to lock against quota code - test IS_QUOTAINIT is | |
1281 | * just for speedup... | |
1282 | */ | |
1283 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) | |
1284 | if (!IS_NOQUOTA(inode)) | |
1285 | remove_inode_dquot_ref(inode, type, tofree_head); | |
1286 | ||
1287 | spin_unlock(&inode_lock); | |
1288 | } | |
1289 | ||
1290 | #endif | |
1291 | ||
1292 | int inode_wait(void *word) | |
1293 | { | |
1294 | schedule(); | |
1295 | return 0; | |
1296 | } | |
1297 | ||
1298 | /* | |
168a9fd6 MS |
1299 | * If we try to find an inode in the inode hash while it is being |
1300 | * deleted, we have to wait until the filesystem completes its | |
1301 | * deletion before reporting that it isn't found. This function waits | |
1302 | * until the deletion _might_ have completed. Callers are responsible | |
1303 | * to recheck inode state. | |
1304 | * | |
1305 | * It doesn't matter if I_LOCK is not set initially, a call to | |
1306 | * wake_up_inode() after removing from the hash list will DTRT. | |
1307 | * | |
1da177e4 LT |
1308 | * This is called with inode_lock held. |
1309 | */ | |
1310 | static void __wait_on_freeing_inode(struct inode *inode) | |
1311 | { | |
1312 | wait_queue_head_t *wq; | |
1313 | DEFINE_WAIT_BIT(wait, &inode->i_state, __I_LOCK); | |
1da177e4 LT |
1314 | wq = bit_waitqueue(&inode->i_state, __I_LOCK); |
1315 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); | |
1316 | spin_unlock(&inode_lock); | |
1317 | schedule(); | |
1318 | finish_wait(wq, &wait.wait); | |
1319 | spin_lock(&inode_lock); | |
1320 | } | |
1321 | ||
1322 | void wake_up_inode(struct inode *inode) | |
1323 | { | |
1324 | /* | |
1325 | * Prevent speculative execution through spin_unlock(&inode_lock); | |
1326 | */ | |
1327 | smp_mb(); | |
1328 | wake_up_bit(&inode->i_state, __I_LOCK); | |
1329 | } | |
1330 | ||
1331 | static __initdata unsigned long ihash_entries; | |
1332 | static int __init set_ihash_entries(char *str) | |
1333 | { | |
1334 | if (!str) | |
1335 | return 0; | |
1336 | ihash_entries = simple_strtoul(str, &str, 0); | |
1337 | return 1; | |
1338 | } | |
1339 | __setup("ihash_entries=", set_ihash_entries); | |
1340 | ||
1341 | /* | |
1342 | * Initialize the waitqueues and inode hash table. | |
1343 | */ | |
1344 | void __init inode_init_early(void) | |
1345 | { | |
1346 | int loop; | |
1347 | ||
1348 | /* If hashes are distributed across NUMA nodes, defer | |
1349 | * hash allocation until vmalloc space is available. | |
1350 | */ | |
1351 | if (hashdist) | |
1352 | return; | |
1353 | ||
1354 | inode_hashtable = | |
1355 | alloc_large_system_hash("Inode-cache", | |
1356 | sizeof(struct hlist_head), | |
1357 | ihash_entries, | |
1358 | 14, | |
1359 | HASH_EARLY, | |
1360 | &i_hash_shift, | |
1361 | &i_hash_mask, | |
1362 | 0); | |
1363 | ||
1364 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1365 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1366 | } | |
1367 | ||
1368 | void __init inode_init(unsigned long mempages) | |
1369 | { | |
1370 | int loop; | |
1371 | ||
1372 | /* inode slab cache */ | |
b0196009 PJ |
1373 | inode_cachep = kmem_cache_create("inode_cache", |
1374 | sizeof(struct inode), | |
1375 | 0, | |
1376 | (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| | |
1377 | SLAB_MEM_SPREAD), | |
1378 | init_once, | |
1379 | NULL); | |
1da177e4 LT |
1380 | set_shrinker(DEFAULT_SEEKS, shrink_icache_memory); |
1381 | ||
1382 | /* Hash may have been set up in inode_init_early */ | |
1383 | if (!hashdist) | |
1384 | return; | |
1385 | ||
1386 | inode_hashtable = | |
1387 | alloc_large_system_hash("Inode-cache", | |
1388 | sizeof(struct hlist_head), | |
1389 | ihash_entries, | |
1390 | 14, | |
1391 | 0, | |
1392 | &i_hash_shift, | |
1393 | &i_hash_mask, | |
1394 | 0); | |
1395 | ||
1396 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1397 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1398 | } | |
1399 | ||
1400 | void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) | |
1401 | { | |
1402 | inode->i_mode = mode; | |
1403 | if (S_ISCHR(mode)) { | |
1404 | inode->i_fop = &def_chr_fops; | |
1405 | inode->i_rdev = rdev; | |
1406 | } else if (S_ISBLK(mode)) { | |
1407 | inode->i_fop = &def_blk_fops; | |
1408 | inode->i_rdev = rdev; | |
1409 | } else if (S_ISFIFO(mode)) | |
1410 | inode->i_fop = &def_fifo_fops; | |
1411 | else if (S_ISSOCK(mode)) | |
1412 | inode->i_fop = &bad_sock_fops; | |
1413 | else | |
1414 | printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o)\n", | |
1415 | mode); | |
1416 | } | |
1417 | EXPORT_SYMBOL(init_special_inode); |