Commit | Line | Data |
---|---|---|
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> | |
24 | ||
25 | /* | |
26 | * This is needed for the following functions: | |
27 | * - inode_has_buffers | |
28 | * - invalidate_inode_buffers | |
1da177e4 LT |
29 | * - invalidate_bdev |
30 | * | |
31 | * FIXME: remove all knowledge of the buffer layer from this file | |
32 | */ | |
33 | #include <linux/buffer_head.h> | |
34 | ||
35 | /* | |
36 | * New inode.c implementation. | |
37 | * | |
38 | * This implementation has the basic premise of trying | |
39 | * to be extremely low-overhead and SMP-safe, yet be | |
40 | * simple enough to be "obviously correct". | |
41 | * | |
42 | * Famous last words. | |
43 | */ | |
44 | ||
45 | /* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */ | |
46 | ||
47 | /* #define INODE_PARANOIA 1 */ | |
48 | /* #define INODE_DEBUG 1 */ | |
49 | ||
50 | /* | |
51 | * Inode lookup is no longer as critical as it used to be: | |
52 | * most of the lookups are going to be through the dcache. | |
53 | */ | |
54 | #define I_HASHBITS i_hash_shift | |
55 | #define I_HASHMASK i_hash_mask | |
56 | ||
57 | static unsigned int i_hash_mask; | |
58 | static unsigned int i_hash_shift; | |
59 | ||
60 | /* | |
61 | * Each inode can be on two separate lists. One is | |
62 | * the hash list of the inode, used for lookups. The | |
63 | * other linked list is the "type" list: | |
64 | * "in_use" - valid inode, i_count > 0, i_nlink > 0 | |
65 | * "dirty" - as "in_use" but also dirty | |
66 | * "unused" - valid inode, i_count = 0 | |
67 | * | |
68 | * A "dirty" list is maintained for each super block, | |
69 | * allowing for low-overhead inode sync() operations. | |
70 | */ | |
71 | ||
72 | LIST_HEAD(inode_in_use); | |
73 | LIST_HEAD(inode_unused); | |
74 | static struct hlist_head *inode_hashtable; | |
75 | ||
76 | /* | |
77 | * A simple spinlock to protect the list manipulations. | |
78 | * | |
79 | * NOTE! You also have to own the lock if you change | |
80 | * the i_state of an inode while it is in use.. | |
81 | */ | |
82 | DEFINE_SPINLOCK(inode_lock); | |
83 | ||
84 | /* | |
85 | * iprune_sem provides exclusion between the kswapd or try_to_free_pages | |
86 | * icache shrinking path, and the umount path. Without this exclusion, | |
87 | * by the time prune_icache calls iput for the inode whose pages it has | |
88 | * been invalidating, or by the time it calls clear_inode & destroy_inode | |
89 | * from its final dispose_list, the struct super_block they refer to | |
90 | * (for inode->i_sb->s_op) may already have been freed and reused. | |
91 | */ | |
92 | DECLARE_MUTEX(iprune_sem); | |
93 | ||
94 | /* | |
95 | * Statistics gathering.. | |
96 | */ | |
97 | struct inodes_stat_t inodes_stat; | |
98 | ||
99 | static kmem_cache_t * inode_cachep; | |
100 | ||
101 | static struct inode *alloc_inode(struct super_block *sb) | |
102 | { | |
103 | static struct address_space_operations empty_aops; | |
104 | static struct inode_operations empty_iops; | |
105 | static struct file_operations empty_fops; | |
106 | struct inode *inode; | |
107 | ||
108 | if (sb->s_op->alloc_inode) | |
109 | inode = sb->s_op->alloc_inode(sb); | |
110 | else | |
111 | inode = (struct inode *) kmem_cache_alloc(inode_cachep, SLAB_KERNEL); | |
112 | ||
113 | if (inode) { | |
114 | struct address_space * const mapping = &inode->i_data; | |
115 | ||
116 | inode->i_sb = sb; | |
117 | inode->i_blkbits = sb->s_blocksize_bits; | |
118 | inode->i_flags = 0; | |
119 | atomic_set(&inode->i_count, 1); | |
120 | inode->i_op = &empty_iops; | |
121 | inode->i_fop = &empty_fops; | |
122 | inode->i_nlink = 1; | |
123 | atomic_set(&inode->i_writecount, 0); | |
124 | inode->i_size = 0; | |
125 | inode->i_blocks = 0; | |
126 | inode->i_bytes = 0; | |
127 | inode->i_generation = 0; | |
128 | #ifdef CONFIG_QUOTA | |
129 | memset(&inode->i_dquot, 0, sizeof(inode->i_dquot)); | |
130 | #endif | |
131 | inode->i_pipe = NULL; | |
132 | inode->i_bdev = NULL; | |
133 | inode->i_cdev = NULL; | |
134 | inode->i_rdev = 0; | |
135 | inode->i_security = NULL; | |
136 | inode->dirtied_when = 0; | |
137 | if (security_inode_alloc(inode)) { | |
138 | if (inode->i_sb->s_op->destroy_inode) | |
139 | inode->i_sb->s_op->destroy_inode(inode); | |
140 | else | |
141 | kmem_cache_free(inode_cachep, (inode)); | |
142 | return NULL; | |
143 | } | |
144 | ||
145 | mapping->a_ops = &empty_aops; | |
146 | mapping->host = inode; | |
147 | mapping->flags = 0; | |
148 | mapping_set_gfp_mask(mapping, GFP_HIGHUSER); | |
149 | mapping->assoc_mapping = NULL; | |
150 | mapping->backing_dev_info = &default_backing_dev_info; | |
151 | ||
152 | /* | |
153 | * If the block_device provides a backing_dev_info for client | |
154 | * inodes then use that. Otherwise the inode share the bdev's | |
155 | * backing_dev_info. | |
156 | */ | |
157 | if (sb->s_bdev) { | |
158 | struct backing_dev_info *bdi; | |
159 | ||
160 | bdi = sb->s_bdev->bd_inode_backing_dev_info; | |
161 | if (!bdi) | |
162 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; | |
163 | mapping->backing_dev_info = bdi; | |
164 | } | |
165 | memset(&inode->u, 0, sizeof(inode->u)); | |
166 | inode->i_mapping = mapping; | |
167 | } | |
168 | return inode; | |
169 | } | |
170 | ||
171 | void destroy_inode(struct inode *inode) | |
172 | { | |
173 | if (inode_has_buffers(inode)) | |
174 | BUG(); | |
175 | security_inode_free(inode); | |
176 | if (inode->i_sb->s_op->destroy_inode) | |
177 | inode->i_sb->s_op->destroy_inode(inode); | |
178 | else | |
179 | kmem_cache_free(inode_cachep, (inode)); | |
180 | } | |
181 | ||
182 | ||
183 | /* | |
184 | * These are initializations that only need to be done | |
185 | * once, because the fields are idempotent across use | |
186 | * of the inode, so let the slab aware of that. | |
187 | */ | |
188 | void inode_init_once(struct inode *inode) | |
189 | { | |
190 | memset(inode, 0, sizeof(*inode)); | |
191 | INIT_HLIST_NODE(&inode->i_hash); | |
192 | INIT_LIST_HEAD(&inode->i_dentry); | |
193 | INIT_LIST_HEAD(&inode->i_devices); | |
194 | sema_init(&inode->i_sem, 1); | |
195 | init_rwsem(&inode->i_alloc_sem); | |
196 | INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); | |
197 | rwlock_init(&inode->i_data.tree_lock); | |
198 | spin_lock_init(&inode->i_data.i_mmap_lock); | |
199 | INIT_LIST_HEAD(&inode->i_data.private_list); | |
200 | spin_lock_init(&inode->i_data.private_lock); | |
201 | INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap); | |
202 | INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); | |
203 | spin_lock_init(&inode->i_lock); | |
204 | i_size_ordered_init(inode); | |
205 | } | |
206 | ||
207 | EXPORT_SYMBOL(inode_init_once); | |
208 | ||
209 | static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) | |
210 | { | |
211 | struct inode * inode = (struct inode *) foo; | |
212 | ||
213 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
214 | SLAB_CTOR_CONSTRUCTOR) | |
215 | inode_init_once(inode); | |
216 | } | |
217 | ||
218 | /* | |
219 | * inode_lock must be held | |
220 | */ | |
221 | void __iget(struct inode * inode) | |
222 | { | |
223 | if (atomic_read(&inode->i_count)) { | |
224 | atomic_inc(&inode->i_count); | |
225 | return; | |
226 | } | |
227 | atomic_inc(&inode->i_count); | |
228 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
229 | list_move(&inode->i_list, &inode_in_use); | |
230 | inodes_stat.nr_unused--; | |
231 | } | |
232 | ||
233 | /** | |
234 | * clear_inode - clear an inode | |
235 | * @inode: inode to clear | |
236 | * | |
237 | * This is called by the filesystem to tell us | |
238 | * that the inode is no longer useful. We just | |
239 | * terminate it with extreme prejudice. | |
240 | */ | |
241 | void clear_inode(struct inode *inode) | |
242 | { | |
243 | might_sleep(); | |
244 | invalidate_inode_buffers(inode); | |
245 | ||
246 | if (inode->i_data.nrpages) | |
247 | BUG(); | |
248 | if (!(inode->i_state & I_FREEING)) | |
249 | BUG(); | |
250 | if (inode->i_state & I_CLEAR) | |
251 | BUG(); | |
252 | wait_on_inode(inode); | |
253 | DQUOT_DROP(inode); | |
254 | if (inode->i_sb && inode->i_sb->s_op->clear_inode) | |
255 | inode->i_sb->s_op->clear_inode(inode); | |
256 | if (inode->i_bdev) | |
257 | bd_forget(inode); | |
258 | if (inode->i_cdev) | |
259 | cd_forget(inode); | |
260 | inode->i_state = I_CLEAR; | |
261 | } | |
262 | ||
263 | EXPORT_SYMBOL(clear_inode); | |
264 | ||
265 | /* | |
266 | * dispose_list - dispose of the contents of a local list | |
267 | * @head: the head of the list to free | |
268 | * | |
269 | * Dispose-list gets a local list with local inodes in it, so it doesn't | |
270 | * need to worry about list corruption and SMP locks. | |
271 | */ | |
272 | static void dispose_list(struct list_head *head) | |
273 | { | |
274 | int nr_disposed = 0; | |
275 | ||
276 | while (!list_empty(head)) { | |
277 | struct inode *inode; | |
278 | ||
279 | inode = list_entry(head->next, struct inode, i_list); | |
280 | list_del(&inode->i_list); | |
281 | ||
282 | if (inode->i_data.nrpages) | |
283 | truncate_inode_pages(&inode->i_data, 0); | |
284 | clear_inode(inode); | |
285 | destroy_inode(inode); | |
286 | nr_disposed++; | |
287 | } | |
288 | spin_lock(&inode_lock); | |
289 | inodes_stat.nr_inodes -= nr_disposed; | |
290 | spin_unlock(&inode_lock); | |
291 | } | |
292 | ||
293 | /* | |
294 | * Invalidate all inodes for a device. | |
295 | */ | |
296 | static int invalidate_list(struct list_head *head, struct list_head *dispose) | |
297 | { | |
298 | struct list_head *next; | |
299 | int busy = 0, count = 0; | |
300 | ||
301 | next = head->next; | |
302 | for (;;) { | |
303 | struct list_head * tmp = next; | |
304 | struct inode * inode; | |
305 | ||
306 | /* | |
307 | * We can reschedule here without worrying about the list's | |
308 | * consistency because the per-sb list of inodes must not | |
309 | * change during umount anymore, and because iprune_sem keeps | |
310 | * shrink_icache_memory() away. | |
311 | */ | |
312 | cond_resched_lock(&inode_lock); | |
313 | ||
314 | next = next->next; | |
315 | if (tmp == head) | |
316 | break; | |
317 | inode = list_entry(tmp, struct inode, i_sb_list); | |
318 | invalidate_inode_buffers(inode); | |
319 | if (!atomic_read(&inode->i_count)) { | |
320 | hlist_del_init(&inode->i_hash); | |
321 | list_del(&inode->i_sb_list); | |
322 | list_move(&inode->i_list, dispose); | |
323 | inode->i_state |= I_FREEING; | |
324 | count++; | |
325 | continue; | |
326 | } | |
327 | busy = 1; | |
328 | } | |
329 | /* only unused inodes may be cached with i_count zero */ | |
330 | inodes_stat.nr_unused -= count; | |
331 | return busy; | |
332 | } | |
333 | ||
1da177e4 LT |
334 | /** |
335 | * invalidate_inodes - discard the inodes on a device | |
336 | * @sb: superblock | |
337 | * | |
338 | * Discard all of the inodes for a given superblock. If the discard | |
339 | * fails because there are busy inodes then a non zero value is returned. | |
340 | * If the discard is successful all the inodes have been discarded. | |
341 | */ | |
342 | int invalidate_inodes(struct super_block * sb) | |
343 | { | |
344 | int busy; | |
345 | LIST_HEAD(throw_away); | |
346 | ||
347 | down(&iprune_sem); | |
348 | spin_lock(&inode_lock); | |
349 | busy = invalidate_list(&sb->s_inodes, &throw_away); | |
350 | spin_unlock(&inode_lock); | |
351 | ||
352 | dispose_list(&throw_away); | |
353 | up(&iprune_sem); | |
354 | ||
355 | return busy; | |
356 | } | |
357 | ||
358 | EXPORT_SYMBOL(invalidate_inodes); | |
359 | ||
2ef41634 | 360 | int __invalidate_device(struct block_device *bdev) |
1da177e4 | 361 | { |
2ef41634 CH |
362 | struct super_block *sb = get_super(bdev); |
363 | int res = 0; | |
1da177e4 | 364 | |
1da177e4 LT |
365 | if (sb) { |
366 | /* | |
367 | * no need to lock the super, get_super holds the | |
368 | * read semaphore so the filesystem cannot go away | |
369 | * under us (->put_super runs with the write lock | |
370 | * hold). | |
371 | */ | |
372 | shrink_dcache_sb(sb); | |
373 | res = invalidate_inodes(sb); | |
374 | drop_super(sb); | |
375 | } | |
376 | invalidate_bdev(bdev, 0); | |
377 | return res; | |
378 | } | |
1da177e4 LT |
379 | EXPORT_SYMBOL(__invalidate_device); |
380 | ||
381 | static int can_unuse(struct inode *inode) | |
382 | { | |
383 | if (inode->i_state) | |
384 | return 0; | |
385 | if (inode_has_buffers(inode)) | |
386 | return 0; | |
387 | if (atomic_read(&inode->i_count)) | |
388 | return 0; | |
389 | if (inode->i_data.nrpages) | |
390 | return 0; | |
391 | return 1; | |
392 | } | |
393 | ||
394 | /* | |
395 | * Scan `goal' inodes on the unused list for freeable ones. They are moved to | |
396 | * a temporary list and then are freed outside inode_lock by dispose_list(). | |
397 | * | |
398 | * Any inodes which are pinned purely because of attached pagecache have their | |
399 | * pagecache removed. We expect the final iput() on that inode to add it to | |
400 | * the front of the inode_unused list. So look for it there and if the | |
401 | * inode is still freeable, proceed. The right inode is found 99.9% of the | |
402 | * time in testing on a 4-way. | |
403 | * | |
404 | * If the inode has metadata buffers attached to mapping->private_list then | |
405 | * try to remove them. | |
406 | */ | |
407 | static void prune_icache(int nr_to_scan) | |
408 | { | |
409 | LIST_HEAD(freeable); | |
410 | int nr_pruned = 0; | |
411 | int nr_scanned; | |
412 | unsigned long reap = 0; | |
413 | ||
414 | down(&iprune_sem); | |
415 | spin_lock(&inode_lock); | |
416 | for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { | |
417 | struct inode *inode; | |
418 | ||
419 | if (list_empty(&inode_unused)) | |
420 | break; | |
421 | ||
422 | inode = list_entry(inode_unused.prev, struct inode, i_list); | |
423 | ||
424 | if (inode->i_state || atomic_read(&inode->i_count)) { | |
425 | list_move(&inode->i_list, &inode_unused); | |
426 | continue; | |
427 | } | |
428 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { | |
429 | __iget(inode); | |
430 | spin_unlock(&inode_lock); | |
431 | if (remove_inode_buffers(inode)) | |
432 | reap += invalidate_inode_pages(&inode->i_data); | |
433 | iput(inode); | |
434 | spin_lock(&inode_lock); | |
435 | ||
436 | if (inode != list_entry(inode_unused.next, | |
437 | struct inode, i_list)) | |
438 | continue; /* wrong inode or list_empty */ | |
439 | if (!can_unuse(inode)) | |
440 | continue; | |
441 | } | |
442 | hlist_del_init(&inode->i_hash); | |
443 | list_del_init(&inode->i_sb_list); | |
444 | list_move(&inode->i_list, &freeable); | |
445 | inode->i_state |= I_FREEING; | |
446 | nr_pruned++; | |
447 | } | |
448 | inodes_stat.nr_unused -= nr_pruned; | |
449 | spin_unlock(&inode_lock); | |
450 | ||
451 | dispose_list(&freeable); | |
452 | up(&iprune_sem); | |
453 | ||
454 | if (current_is_kswapd()) | |
455 | mod_page_state(kswapd_inodesteal, reap); | |
456 | else | |
457 | mod_page_state(pginodesteal, reap); | |
458 | } | |
459 | ||
460 | /* | |
461 | * shrink_icache_memory() will attempt to reclaim some unused inodes. Here, | |
462 | * "unused" means that no dentries are referring to the inodes: the files are | |
463 | * not open and the dcache references to those inodes have already been | |
464 | * reclaimed. | |
465 | * | |
466 | * This function is passed the number of inodes to scan, and it returns the | |
467 | * total number of remaining possibly-reclaimable inodes. | |
468 | */ | |
469 | static int shrink_icache_memory(int nr, unsigned int gfp_mask) | |
470 | { | |
471 | if (nr) { | |
472 | /* | |
473 | * Nasty deadlock avoidance. We may hold various FS locks, | |
474 | * and we don't want to recurse into the FS that called us | |
475 | * in clear_inode() and friends.. | |
476 | */ | |
477 | if (!(gfp_mask & __GFP_FS)) | |
478 | return -1; | |
479 | prune_icache(nr); | |
480 | } | |
481 | return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure; | |
482 | } | |
483 | ||
484 | static void __wait_on_freeing_inode(struct inode *inode); | |
485 | /* | |
486 | * Called with the inode lock held. | |
487 | * NOTE: we are not increasing the inode-refcount, you must call __iget() | |
488 | * by hand after calling find_inode now! This simplifies iunique and won't | |
489 | * add any additional branch in the common code. | |
490 | */ | |
491 | static struct inode * find_inode(struct super_block * sb, struct hlist_head *head, int (*test)(struct inode *, void *), void *data) | |
492 | { | |
493 | struct hlist_node *node; | |
494 | struct inode * inode = NULL; | |
495 | ||
496 | repeat: | |
497 | hlist_for_each (node, head) { | |
498 | inode = hlist_entry(node, struct inode, i_hash); | |
499 | if (inode->i_sb != sb) | |
500 | continue; | |
501 | if (!test(inode, data)) | |
502 | continue; | |
503 | if (inode->i_state & (I_FREEING|I_CLEAR)) { | |
504 | __wait_on_freeing_inode(inode); | |
505 | goto repeat; | |
506 | } | |
507 | break; | |
508 | } | |
509 | return node ? inode : NULL; | |
510 | } | |
511 | ||
512 | /* | |
513 | * find_inode_fast is the fast path version of find_inode, see the comment at | |
514 | * iget_locked for details. | |
515 | */ | |
516 | static struct inode * find_inode_fast(struct super_block * sb, struct hlist_head *head, unsigned long ino) | |
517 | { | |
518 | struct hlist_node *node; | |
519 | struct inode * inode = NULL; | |
520 | ||
521 | repeat: | |
522 | hlist_for_each (node, head) { | |
523 | inode = hlist_entry(node, struct inode, i_hash); | |
524 | if (inode->i_ino != ino) | |
525 | continue; | |
526 | if (inode->i_sb != sb) | |
527 | continue; | |
528 | if (inode->i_state & (I_FREEING|I_CLEAR)) { | |
529 | __wait_on_freeing_inode(inode); | |
530 | goto repeat; | |
531 | } | |
532 | break; | |
533 | } | |
534 | return node ? inode : NULL; | |
535 | } | |
536 | ||
537 | /** | |
538 | * new_inode - obtain an inode | |
539 | * @sb: superblock | |
540 | * | |
541 | * Allocates a new inode for given superblock. | |
542 | */ | |
543 | struct inode *new_inode(struct super_block *sb) | |
544 | { | |
545 | static unsigned long last_ino; | |
546 | struct inode * inode; | |
547 | ||
548 | spin_lock_prefetch(&inode_lock); | |
549 | ||
550 | inode = alloc_inode(sb); | |
551 | if (inode) { | |
552 | spin_lock(&inode_lock); | |
553 | inodes_stat.nr_inodes++; | |
554 | list_add(&inode->i_list, &inode_in_use); | |
555 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
556 | inode->i_ino = ++last_ino; | |
557 | inode->i_state = 0; | |
558 | spin_unlock(&inode_lock); | |
559 | } | |
560 | return inode; | |
561 | } | |
562 | ||
563 | EXPORT_SYMBOL(new_inode); | |
564 | ||
565 | void unlock_new_inode(struct inode *inode) | |
566 | { | |
567 | /* | |
568 | * This is special! We do not need the spinlock | |
569 | * when clearing I_LOCK, because we're guaranteed | |
570 | * that nobody else tries to do anything about the | |
571 | * state of the inode when it is locked, as we | |
572 | * just created it (so there can be no old holders | |
573 | * that haven't tested I_LOCK). | |
574 | */ | |
575 | inode->i_state &= ~(I_LOCK|I_NEW); | |
576 | wake_up_inode(inode); | |
577 | } | |
578 | ||
579 | EXPORT_SYMBOL(unlock_new_inode); | |
580 | ||
581 | /* | |
582 | * This is called without the inode lock held.. Be careful. | |
583 | * | |
584 | * We no longer cache the sb_flags in i_flags - see fs.h | |
585 | * -- rmk@arm.uk.linux.org | |
586 | */ | |
587 | 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) | |
588 | { | |
589 | struct inode * inode; | |
590 | ||
591 | inode = alloc_inode(sb); | |
592 | if (inode) { | |
593 | struct inode * old; | |
594 | ||
595 | spin_lock(&inode_lock); | |
596 | /* We released the lock, so.. */ | |
597 | old = find_inode(sb, head, test, data); | |
598 | if (!old) { | |
599 | if (set(inode, data)) | |
600 | goto set_failed; | |
601 | ||
602 | inodes_stat.nr_inodes++; | |
603 | list_add(&inode->i_list, &inode_in_use); | |
604 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
605 | hlist_add_head(&inode->i_hash, head); | |
606 | inode->i_state = I_LOCK|I_NEW; | |
607 | spin_unlock(&inode_lock); | |
608 | ||
609 | /* Return the locked inode with I_NEW set, the | |
610 | * caller is responsible for filling in the contents | |
611 | */ | |
612 | return inode; | |
613 | } | |
614 | ||
615 | /* | |
616 | * Uhhuh, somebody else created the same inode under | |
617 | * us. Use the old inode instead of the one we just | |
618 | * allocated. | |
619 | */ | |
620 | __iget(old); | |
621 | spin_unlock(&inode_lock); | |
622 | destroy_inode(inode); | |
623 | inode = old; | |
624 | wait_on_inode(inode); | |
625 | } | |
626 | return inode; | |
627 | ||
628 | set_failed: | |
629 | spin_unlock(&inode_lock); | |
630 | destroy_inode(inode); | |
631 | return NULL; | |
632 | } | |
633 | ||
634 | /* | |
635 | * get_new_inode_fast is the fast path version of get_new_inode, see the | |
636 | * comment at iget_locked for details. | |
637 | */ | |
638 | static struct inode * get_new_inode_fast(struct super_block *sb, struct hlist_head *head, unsigned long ino) | |
639 | { | |
640 | struct inode * inode; | |
641 | ||
642 | inode = alloc_inode(sb); | |
643 | if (inode) { | |
644 | struct inode * old; | |
645 | ||
646 | spin_lock(&inode_lock); | |
647 | /* We released the lock, so.. */ | |
648 | old = find_inode_fast(sb, head, ino); | |
649 | if (!old) { | |
650 | inode->i_ino = ino; | |
651 | inodes_stat.nr_inodes++; | |
652 | list_add(&inode->i_list, &inode_in_use); | |
653 | list_add(&inode->i_sb_list, &sb->s_inodes); | |
654 | hlist_add_head(&inode->i_hash, head); | |
655 | inode->i_state = I_LOCK|I_NEW; | |
656 | spin_unlock(&inode_lock); | |
657 | ||
658 | /* Return the locked inode with I_NEW set, the | |
659 | * caller is responsible for filling in the contents | |
660 | */ | |
661 | return inode; | |
662 | } | |
663 | ||
664 | /* | |
665 | * Uhhuh, somebody else created the same inode under | |
666 | * us. Use the old inode instead of the one we just | |
667 | * allocated. | |
668 | */ | |
669 | __iget(old); | |
670 | spin_unlock(&inode_lock); | |
671 | destroy_inode(inode); | |
672 | inode = old; | |
673 | wait_on_inode(inode); | |
674 | } | |
675 | return inode; | |
676 | } | |
677 | ||
678 | static inline unsigned long hash(struct super_block *sb, unsigned long hashval) | |
679 | { | |
680 | unsigned long tmp; | |
681 | ||
682 | tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / | |
683 | L1_CACHE_BYTES; | |
684 | tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS); | |
685 | return tmp & I_HASHMASK; | |
686 | } | |
687 | ||
688 | /** | |
689 | * iunique - get a unique inode number | |
690 | * @sb: superblock | |
691 | * @max_reserved: highest reserved inode number | |
692 | * | |
693 | * Obtain an inode number that is unique on the system for a given | |
694 | * superblock. This is used by file systems that have no natural | |
695 | * permanent inode numbering system. An inode number is returned that | |
696 | * is higher than the reserved limit but unique. | |
697 | * | |
698 | * BUGS: | |
699 | * With a large number of inodes live on the file system this function | |
700 | * currently becomes quite slow. | |
701 | */ | |
702 | ino_t iunique(struct super_block *sb, ino_t max_reserved) | |
703 | { | |
704 | static ino_t counter; | |
705 | struct inode *inode; | |
706 | struct hlist_head * head; | |
707 | ino_t res; | |
708 | spin_lock(&inode_lock); | |
709 | retry: | |
710 | if (counter > max_reserved) { | |
711 | head = inode_hashtable + hash(sb,counter); | |
712 | res = counter++; | |
713 | inode = find_inode_fast(sb, head, res); | |
714 | if (!inode) { | |
715 | spin_unlock(&inode_lock); | |
716 | return res; | |
717 | } | |
718 | } else { | |
719 | counter = max_reserved + 1; | |
720 | } | |
721 | goto retry; | |
722 | ||
723 | } | |
724 | ||
725 | EXPORT_SYMBOL(iunique); | |
726 | ||
727 | struct inode *igrab(struct inode *inode) | |
728 | { | |
729 | spin_lock(&inode_lock); | |
730 | if (!(inode->i_state & I_FREEING)) | |
731 | __iget(inode); | |
732 | else | |
733 | /* | |
734 | * Handle the case where s_op->clear_inode is not been | |
735 | * called yet, and somebody is calling igrab | |
736 | * while the inode is getting freed. | |
737 | */ | |
738 | inode = NULL; | |
739 | spin_unlock(&inode_lock); | |
740 | return inode; | |
741 | } | |
742 | ||
743 | EXPORT_SYMBOL(igrab); | |
744 | ||
745 | /** | |
746 | * ifind - internal function, you want ilookup5() or iget5(). | |
747 | * @sb: super block of file system to search | |
748 | * @head: the head of the list to search | |
749 | * @test: callback used for comparisons between inodes | |
750 | * @data: opaque data pointer to pass to @test | |
751 | * | |
752 | * ifind() searches for the inode specified by @data in the inode | |
753 | * cache. This is a generalized version of ifind_fast() for file systems where | |
754 | * the inode number is not sufficient for unique identification of an inode. | |
755 | * | |
756 | * If the inode is in the cache, the inode is returned with an incremented | |
757 | * reference count. | |
758 | * | |
759 | * Otherwise NULL is returned. | |
760 | * | |
761 | * Note, @test is called with the inode_lock held, so can't sleep. | |
762 | */ | |
763 | static inline struct inode *ifind(struct super_block *sb, | |
764 | struct hlist_head *head, int (*test)(struct inode *, void *), | |
765 | void *data) | |
766 | { | |
767 | struct inode *inode; | |
768 | ||
769 | spin_lock(&inode_lock); | |
770 | inode = find_inode(sb, head, test, data); | |
771 | if (inode) { | |
772 | __iget(inode); | |
773 | spin_unlock(&inode_lock); | |
774 | wait_on_inode(inode); | |
775 | return inode; | |
776 | } | |
777 | spin_unlock(&inode_lock); | |
778 | return NULL; | |
779 | } | |
780 | ||
781 | /** | |
782 | * ifind_fast - internal function, you want ilookup() or iget(). | |
783 | * @sb: super block of file system to search | |
784 | * @head: head of the list to search | |
785 | * @ino: inode number to search for | |
786 | * | |
787 | * ifind_fast() searches for the inode @ino in the inode cache. This is for | |
788 | * file systems where the inode number is sufficient for unique identification | |
789 | * of an inode. | |
790 | * | |
791 | * If the inode is in the cache, the inode is returned with an incremented | |
792 | * reference count. | |
793 | * | |
794 | * Otherwise NULL is returned. | |
795 | */ | |
796 | static inline struct inode *ifind_fast(struct super_block *sb, | |
797 | struct hlist_head *head, unsigned long ino) | |
798 | { | |
799 | struct inode *inode; | |
800 | ||
801 | spin_lock(&inode_lock); | |
802 | inode = find_inode_fast(sb, head, ino); | |
803 | if (inode) { | |
804 | __iget(inode); | |
805 | spin_unlock(&inode_lock); | |
806 | wait_on_inode(inode); | |
807 | return inode; | |
808 | } | |
809 | spin_unlock(&inode_lock); | |
810 | return NULL; | |
811 | } | |
812 | ||
813 | /** | |
814 | * ilookup5 - search for an inode in the inode cache | |
815 | * @sb: super block of file system to search | |
816 | * @hashval: hash value (usually inode number) to search for | |
817 | * @test: callback used for comparisons between inodes | |
818 | * @data: opaque data pointer to pass to @test | |
819 | * | |
820 | * ilookup5() uses ifind() to search for the inode specified by @hashval and | |
821 | * @data in the inode cache. This is a generalized version of ilookup() for | |
822 | * file systems where the inode number is not sufficient for unique | |
823 | * identification of an inode. | |
824 | * | |
825 | * If the inode is in the cache, the inode is returned with an incremented | |
826 | * reference count. | |
827 | * | |
828 | * Otherwise NULL is returned. | |
829 | * | |
830 | * Note, @test is called with the inode_lock held, so can't sleep. | |
831 | */ | |
832 | struct inode *ilookup5(struct super_block *sb, unsigned long hashval, | |
833 | int (*test)(struct inode *, void *), void *data) | |
834 | { | |
835 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
836 | ||
837 | return ifind(sb, head, test, data); | |
838 | } | |
839 | ||
840 | EXPORT_SYMBOL(ilookup5); | |
841 | ||
842 | /** | |
843 | * ilookup - search for an inode in the inode cache | |
844 | * @sb: super block of file system to search | |
845 | * @ino: inode number to search for | |
846 | * | |
847 | * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache. | |
848 | * This is for file systems where the inode number is sufficient for unique | |
849 | * identification of an inode. | |
850 | * | |
851 | * If the inode is in the cache, the inode is returned with an incremented | |
852 | * reference count. | |
853 | * | |
854 | * Otherwise NULL is returned. | |
855 | */ | |
856 | struct inode *ilookup(struct super_block *sb, unsigned long ino) | |
857 | { | |
858 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
859 | ||
860 | return ifind_fast(sb, head, ino); | |
861 | } | |
862 | ||
863 | EXPORT_SYMBOL(ilookup); | |
864 | ||
865 | /** | |
866 | * iget5_locked - obtain an inode from a mounted file system | |
867 | * @sb: super block of file system | |
868 | * @hashval: hash value (usually inode number) to get | |
869 | * @test: callback used for comparisons between inodes | |
870 | * @set: callback used to initialize a new struct inode | |
871 | * @data: opaque data pointer to pass to @test and @set | |
872 | * | |
873 | * This is iget() without the read_inode() portion of get_new_inode(). | |
874 | * | |
875 | * iget5_locked() uses ifind() to search for the inode specified by @hashval | |
876 | * and @data in the inode cache and if present it is returned with an increased | |
877 | * reference count. This is a generalized version of iget_locked() for file | |
878 | * systems where the inode number is not sufficient for unique identification | |
879 | * of an inode. | |
880 | * | |
881 | * If the inode is not in cache, get_new_inode() is called to allocate a new | |
882 | * inode and this is returned locked, hashed, and with the I_NEW flag set. The | |
883 | * file system gets to fill it in before unlocking it via unlock_new_inode(). | |
884 | * | |
885 | * Note both @test and @set are called with the inode_lock held, so can't sleep. | |
886 | */ | |
887 | struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, | |
888 | int (*test)(struct inode *, void *), | |
889 | int (*set)(struct inode *, void *), void *data) | |
890 | { | |
891 | struct hlist_head *head = inode_hashtable + hash(sb, hashval); | |
892 | struct inode *inode; | |
893 | ||
894 | inode = ifind(sb, head, test, data); | |
895 | if (inode) | |
896 | return inode; | |
897 | /* | |
898 | * get_new_inode() will do the right thing, re-trying the search | |
899 | * in case it had to block at any point. | |
900 | */ | |
901 | return get_new_inode(sb, head, test, set, data); | |
902 | } | |
903 | ||
904 | EXPORT_SYMBOL(iget5_locked); | |
905 | ||
906 | /** | |
907 | * iget_locked - obtain an inode from a mounted file system | |
908 | * @sb: super block of file system | |
909 | * @ino: inode number to get | |
910 | * | |
911 | * This is iget() without the read_inode() portion of get_new_inode_fast(). | |
912 | * | |
913 | * iget_locked() uses ifind_fast() to search for the inode specified by @ino in | |
914 | * the inode cache and if present it is returned with an increased reference | |
915 | * count. This is for file systems where the inode number is sufficient for | |
916 | * unique identification of an inode. | |
917 | * | |
918 | * If the inode is not in cache, get_new_inode_fast() is called to allocate a | |
919 | * new inode and this is returned locked, hashed, and with the I_NEW flag set. | |
920 | * The file system gets to fill it in before unlocking it via | |
921 | * unlock_new_inode(). | |
922 | */ | |
923 | struct inode *iget_locked(struct super_block *sb, unsigned long ino) | |
924 | { | |
925 | struct hlist_head *head = inode_hashtable + hash(sb, ino); | |
926 | struct inode *inode; | |
927 | ||
928 | inode = ifind_fast(sb, head, ino); | |
929 | if (inode) | |
930 | return inode; | |
931 | /* | |
932 | * get_new_inode_fast() will do the right thing, re-trying the search | |
933 | * in case it had to block at any point. | |
934 | */ | |
935 | return get_new_inode_fast(sb, head, ino); | |
936 | } | |
937 | ||
938 | EXPORT_SYMBOL(iget_locked); | |
939 | ||
940 | /** | |
941 | * __insert_inode_hash - hash an inode | |
942 | * @inode: unhashed inode | |
943 | * @hashval: unsigned long value used to locate this object in the | |
944 | * inode_hashtable. | |
945 | * | |
946 | * Add an inode to the inode hash for this superblock. | |
947 | */ | |
948 | void __insert_inode_hash(struct inode *inode, unsigned long hashval) | |
949 | { | |
950 | struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval); | |
951 | spin_lock(&inode_lock); | |
952 | hlist_add_head(&inode->i_hash, head); | |
953 | spin_unlock(&inode_lock); | |
954 | } | |
955 | ||
956 | EXPORT_SYMBOL(__insert_inode_hash); | |
957 | ||
958 | /** | |
959 | * remove_inode_hash - remove an inode from the hash | |
960 | * @inode: inode to unhash | |
961 | * | |
962 | * Remove an inode from the superblock. | |
963 | */ | |
964 | void remove_inode_hash(struct inode *inode) | |
965 | { | |
966 | spin_lock(&inode_lock); | |
967 | hlist_del_init(&inode->i_hash); | |
968 | spin_unlock(&inode_lock); | |
969 | } | |
970 | ||
971 | EXPORT_SYMBOL(remove_inode_hash); | |
972 | ||
973 | /* | |
974 | * Tell the filesystem that this inode is no longer of any interest and should | |
975 | * be completely destroyed. | |
976 | * | |
977 | * We leave the inode in the inode hash table until *after* the filesystem's | |
978 | * ->delete_inode completes. This ensures that an iget (such as nfsd might | |
979 | * instigate) will always find up-to-date information either in the hash or on | |
980 | * disk. | |
981 | * | |
982 | * I_FREEING is set so that no-one will take a new reference to the inode while | |
983 | * it is being deleted. | |
984 | */ | |
985 | void generic_delete_inode(struct inode *inode) | |
986 | { | |
987 | struct super_operations *op = inode->i_sb->s_op; | |
988 | ||
989 | list_del_init(&inode->i_list); | |
990 | list_del_init(&inode->i_sb_list); | |
991 | inode->i_state|=I_FREEING; | |
992 | inodes_stat.nr_inodes--; | |
993 | spin_unlock(&inode_lock); | |
994 | ||
995 | if (inode->i_data.nrpages) | |
996 | truncate_inode_pages(&inode->i_data, 0); | |
997 | ||
998 | security_inode_delete(inode); | |
999 | ||
1000 | if (op->delete_inode) { | |
1001 | void (*delete)(struct inode *) = op->delete_inode; | |
1002 | if (!is_bad_inode(inode)) | |
1003 | DQUOT_INIT(inode); | |
1004 | /* s_op->delete_inode internally recalls clear_inode() */ | |
1005 | delete(inode); | |
1006 | } else | |
1007 | clear_inode(inode); | |
1008 | spin_lock(&inode_lock); | |
1009 | hlist_del_init(&inode->i_hash); | |
1010 | spin_unlock(&inode_lock); | |
1011 | wake_up_inode(inode); | |
1012 | if (inode->i_state != I_CLEAR) | |
1013 | BUG(); | |
1014 | destroy_inode(inode); | |
1015 | } | |
1016 | ||
1017 | EXPORT_SYMBOL(generic_delete_inode); | |
1018 | ||
1019 | static void generic_forget_inode(struct inode *inode) | |
1020 | { | |
1021 | struct super_block *sb = inode->i_sb; | |
1022 | ||
1023 | if (!hlist_unhashed(&inode->i_hash)) { | |
1024 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
1025 | list_move(&inode->i_list, &inode_unused); | |
1026 | inodes_stat.nr_unused++; | |
1027 | spin_unlock(&inode_lock); | |
1028 | if (!sb || (sb->s_flags & MS_ACTIVE)) | |
1029 | return; | |
1030 | write_inode_now(inode, 1); | |
1031 | spin_lock(&inode_lock); | |
1032 | inodes_stat.nr_unused--; | |
1033 | hlist_del_init(&inode->i_hash); | |
1034 | } | |
1035 | list_del_init(&inode->i_list); | |
1036 | list_del_init(&inode->i_sb_list); | |
1037 | inode->i_state|=I_FREEING; | |
1038 | inodes_stat.nr_inodes--; | |
1039 | spin_unlock(&inode_lock); | |
1040 | if (inode->i_data.nrpages) | |
1041 | truncate_inode_pages(&inode->i_data, 0); | |
1042 | clear_inode(inode); | |
1043 | destroy_inode(inode); | |
1044 | } | |
1045 | ||
1046 | /* | |
1047 | * Normal UNIX filesystem behaviour: delete the | |
1048 | * inode when the usage count drops to zero, and | |
1049 | * i_nlink is zero. | |
1050 | */ | |
1051 | static void generic_drop_inode(struct inode *inode) | |
1052 | { | |
1053 | if (!inode->i_nlink) | |
1054 | generic_delete_inode(inode); | |
1055 | else | |
1056 | generic_forget_inode(inode); | |
1057 | } | |
1058 | ||
1059 | /* | |
1060 | * Called when we're dropping the last reference | |
1061 | * to an inode. | |
1062 | * | |
1063 | * Call the FS "drop()" function, defaulting to | |
1064 | * the legacy UNIX filesystem behaviour.. | |
1065 | * | |
1066 | * NOTE! NOTE! NOTE! We're called with the inode lock | |
1067 | * held, and the drop function is supposed to release | |
1068 | * the lock! | |
1069 | */ | |
1070 | static inline void iput_final(struct inode *inode) | |
1071 | { | |
1072 | struct super_operations *op = inode->i_sb->s_op; | |
1073 | void (*drop)(struct inode *) = generic_drop_inode; | |
1074 | ||
1075 | if (op && op->drop_inode) | |
1076 | drop = op->drop_inode; | |
1077 | drop(inode); | |
1078 | } | |
1079 | ||
1080 | /** | |
1081 | * iput - put an inode | |
1082 | * @inode: inode to put | |
1083 | * | |
1084 | * Puts an inode, dropping its usage count. If the inode use count hits | |
1085 | * zero, the inode is then freed and may also be destroyed. | |
1086 | * | |
1087 | * Consequently, iput() can sleep. | |
1088 | */ | |
1089 | void iput(struct inode *inode) | |
1090 | { | |
1091 | if (inode) { | |
1092 | struct super_operations *op = inode->i_sb->s_op; | |
1093 | ||
1094 | BUG_ON(inode->i_state == I_CLEAR); | |
1095 | ||
1096 | if (op && op->put_inode) | |
1097 | op->put_inode(inode); | |
1098 | ||
1099 | if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) | |
1100 | iput_final(inode); | |
1101 | } | |
1102 | } | |
1103 | ||
1104 | EXPORT_SYMBOL(iput); | |
1105 | ||
1106 | /** | |
1107 | * bmap - find a block number in a file | |
1108 | * @inode: inode of file | |
1109 | * @block: block to find | |
1110 | * | |
1111 | * Returns the block number on the device holding the inode that | |
1112 | * is the disk block number for the block of the file requested. | |
1113 | * That is, asked for block 4 of inode 1 the function will return the | |
1114 | * disk block relative to the disk start that holds that block of the | |
1115 | * file. | |
1116 | */ | |
1117 | sector_t bmap(struct inode * inode, sector_t block) | |
1118 | { | |
1119 | sector_t res = 0; | |
1120 | if (inode->i_mapping->a_ops->bmap) | |
1121 | res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); | |
1122 | return res; | |
1123 | } | |
1124 | ||
1125 | EXPORT_SYMBOL(bmap); | |
1126 | ||
1127 | /** | |
1128 | * update_atime - update the access time | |
1129 | * @inode: inode accessed | |
1130 | * | |
1131 | * Update the accessed time on an inode and mark it for writeback. | |
1132 | * This function automatically handles read only file systems and media, | |
1133 | * as well as the "noatime" flag and inode specific "noatime" markers. | |
1134 | */ | |
1135 | void update_atime(struct inode *inode) | |
1136 | { | |
1137 | struct timespec now; | |
1138 | ||
1139 | if (IS_NOATIME(inode)) | |
1140 | return; | |
1141 | if (IS_NODIRATIME(inode) && S_ISDIR(inode->i_mode)) | |
1142 | return; | |
1143 | if (IS_RDONLY(inode)) | |
1144 | return; | |
1145 | ||
1146 | now = current_fs_time(inode->i_sb); | |
1147 | if (!timespec_equal(&inode->i_atime, &now)) { | |
1148 | inode->i_atime = now; | |
1149 | mark_inode_dirty_sync(inode); | |
1150 | } else { | |
1151 | if (!timespec_equal(&inode->i_atime, &now)) | |
1152 | inode->i_atime = now; | |
1153 | } | |
1154 | } | |
1155 | ||
1156 | EXPORT_SYMBOL(update_atime); | |
1157 | ||
1158 | /** | |
1159 | * inode_update_time - update mtime and ctime time | |
1160 | * @inode: inode accessed | |
1161 | * @ctime_too: update ctime too | |
1162 | * | |
1163 | * Update the mtime time on an inode and mark it for writeback. | |
1164 | * When ctime_too is specified update the ctime too. | |
1165 | */ | |
1166 | ||
1167 | void inode_update_time(struct inode *inode, int ctime_too) | |
1168 | { | |
1169 | struct timespec now; | |
1170 | int sync_it = 0; | |
1171 | ||
1172 | if (IS_NOCMTIME(inode)) | |
1173 | return; | |
1174 | if (IS_RDONLY(inode)) | |
1175 | return; | |
1176 | ||
1177 | now = current_fs_time(inode->i_sb); | |
1178 | if (!timespec_equal(&inode->i_mtime, &now)) | |
1179 | sync_it = 1; | |
1180 | inode->i_mtime = now; | |
1181 | ||
1182 | if (ctime_too) { | |
1183 | if (!timespec_equal(&inode->i_ctime, &now)) | |
1184 | sync_it = 1; | |
1185 | inode->i_ctime = now; | |
1186 | } | |
1187 | if (sync_it) | |
1188 | mark_inode_dirty_sync(inode); | |
1189 | } | |
1190 | ||
1191 | EXPORT_SYMBOL(inode_update_time); | |
1192 | ||
1193 | int inode_needs_sync(struct inode *inode) | |
1194 | { | |
1195 | if (IS_SYNC(inode)) | |
1196 | return 1; | |
1197 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) | |
1198 | return 1; | |
1199 | return 0; | |
1200 | } | |
1201 | ||
1202 | EXPORT_SYMBOL(inode_needs_sync); | |
1203 | ||
1204 | /* | |
1205 | * Quota functions that want to walk the inode lists.. | |
1206 | */ | |
1207 | #ifdef CONFIG_QUOTA | |
1208 | ||
1209 | /* Function back in dquot.c */ | |
1210 | int remove_inode_dquot_ref(struct inode *, int, struct list_head *); | |
1211 | ||
1212 | void remove_dquot_ref(struct super_block *sb, int type, | |
1213 | struct list_head *tofree_head) | |
1214 | { | |
1215 | struct inode *inode; | |
1216 | ||
1217 | if (!sb->dq_op) | |
1218 | return; /* nothing to do */ | |
1219 | spin_lock(&inode_lock); /* This lock is for inodes code */ | |
1220 | ||
1221 | /* | |
1222 | * We don't have to lock against quota code - test IS_QUOTAINIT is | |
1223 | * just for speedup... | |
1224 | */ | |
1225 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) | |
1226 | if (!IS_NOQUOTA(inode)) | |
1227 | remove_inode_dquot_ref(inode, type, tofree_head); | |
1228 | ||
1229 | spin_unlock(&inode_lock); | |
1230 | } | |
1231 | ||
1232 | #endif | |
1233 | ||
1234 | int inode_wait(void *word) | |
1235 | { | |
1236 | schedule(); | |
1237 | return 0; | |
1238 | } | |
1239 | ||
1240 | /* | |
1241 | * If we try to find an inode in the inode hash while it is being deleted, we | |
1242 | * have to wait until the filesystem completes its deletion before reporting | |
1243 | * that it isn't found. This is because iget will immediately call | |
1244 | * ->read_inode, and we want to be sure that evidence of the deletion is found | |
1245 | * by ->read_inode. | |
1246 | * This is called with inode_lock held. | |
1247 | */ | |
1248 | static void __wait_on_freeing_inode(struct inode *inode) | |
1249 | { | |
1250 | wait_queue_head_t *wq; | |
1251 | DEFINE_WAIT_BIT(wait, &inode->i_state, __I_LOCK); | |
1252 | ||
1253 | /* | |
1254 | * I_FREEING and I_CLEAR are cleared in process context under | |
1255 | * inode_lock, so we have to give the tasks who would clear them | |
1256 | * a chance to run and acquire inode_lock. | |
1257 | */ | |
1258 | if (!(inode->i_state & I_LOCK)) { | |
1259 | spin_unlock(&inode_lock); | |
1260 | yield(); | |
1261 | spin_lock(&inode_lock); | |
1262 | return; | |
1263 | } | |
1264 | wq = bit_waitqueue(&inode->i_state, __I_LOCK); | |
1265 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); | |
1266 | spin_unlock(&inode_lock); | |
1267 | schedule(); | |
1268 | finish_wait(wq, &wait.wait); | |
1269 | spin_lock(&inode_lock); | |
1270 | } | |
1271 | ||
1272 | void wake_up_inode(struct inode *inode) | |
1273 | { | |
1274 | /* | |
1275 | * Prevent speculative execution through spin_unlock(&inode_lock); | |
1276 | */ | |
1277 | smp_mb(); | |
1278 | wake_up_bit(&inode->i_state, __I_LOCK); | |
1279 | } | |
1280 | ||
1281 | static __initdata unsigned long ihash_entries; | |
1282 | static int __init set_ihash_entries(char *str) | |
1283 | { | |
1284 | if (!str) | |
1285 | return 0; | |
1286 | ihash_entries = simple_strtoul(str, &str, 0); | |
1287 | return 1; | |
1288 | } | |
1289 | __setup("ihash_entries=", set_ihash_entries); | |
1290 | ||
1291 | /* | |
1292 | * Initialize the waitqueues and inode hash table. | |
1293 | */ | |
1294 | void __init inode_init_early(void) | |
1295 | { | |
1296 | int loop; | |
1297 | ||
1298 | /* If hashes are distributed across NUMA nodes, defer | |
1299 | * hash allocation until vmalloc space is available. | |
1300 | */ | |
1301 | if (hashdist) | |
1302 | return; | |
1303 | ||
1304 | inode_hashtable = | |
1305 | alloc_large_system_hash("Inode-cache", | |
1306 | sizeof(struct hlist_head), | |
1307 | ihash_entries, | |
1308 | 14, | |
1309 | HASH_EARLY, | |
1310 | &i_hash_shift, | |
1311 | &i_hash_mask, | |
1312 | 0); | |
1313 | ||
1314 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1315 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1316 | } | |
1317 | ||
1318 | void __init inode_init(unsigned long mempages) | |
1319 | { | |
1320 | int loop; | |
1321 | ||
1322 | /* inode slab cache */ | |
1323 | inode_cachep = kmem_cache_create("inode_cache", sizeof(struct inode), | |
e422fd2c | 1324 | 0, SLAB_RECLAIM_ACCOUNT|SLAB_PANIC, init_once, NULL); |
1da177e4 LT |
1325 | set_shrinker(DEFAULT_SEEKS, shrink_icache_memory); |
1326 | ||
1327 | /* Hash may have been set up in inode_init_early */ | |
1328 | if (!hashdist) | |
1329 | return; | |
1330 | ||
1331 | inode_hashtable = | |
1332 | alloc_large_system_hash("Inode-cache", | |
1333 | sizeof(struct hlist_head), | |
1334 | ihash_entries, | |
1335 | 14, | |
1336 | 0, | |
1337 | &i_hash_shift, | |
1338 | &i_hash_mask, | |
1339 | 0); | |
1340 | ||
1341 | for (loop = 0; loop < (1 << i_hash_shift); loop++) | |
1342 | INIT_HLIST_HEAD(&inode_hashtable[loop]); | |
1343 | } | |
1344 | ||
1345 | void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) | |
1346 | { | |
1347 | inode->i_mode = mode; | |
1348 | if (S_ISCHR(mode)) { | |
1349 | inode->i_fop = &def_chr_fops; | |
1350 | inode->i_rdev = rdev; | |
1351 | } else if (S_ISBLK(mode)) { | |
1352 | inode->i_fop = &def_blk_fops; | |
1353 | inode->i_rdev = rdev; | |
1354 | } else if (S_ISFIFO(mode)) | |
1355 | inode->i_fop = &def_fifo_fops; | |
1356 | else if (S_ISSOCK(mode)) | |
1357 | inode->i_fop = &bad_sock_fops; | |
1358 | else | |
1359 | printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o)\n", | |
1360 | mode); | |
1361 | } | |
1362 | EXPORT_SYMBOL(init_special_inode); |