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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/inode.c
3 *
4 * (C) 1997 Linus Torvalds
5 */
6
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <linux/fs.h>
8#include <linux/mm.h>
9#include <linux/dcache.h>
10#include <linux/init.h>
11#include <linux/quotaops.h>
12#include <linux/slab.h>
13#include <linux/writeback.h>
14#include <linux/module.h>
15#include <linux/backing-dev.h>
16#include <linux/wait.h>
Nick Piggin88e0fbc2009-09-22 16:43:50 -070017#include <linux/rwsem.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#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>
Robert Love0eeca282005-07-12 17:06:03 -040024#include <linux/inotify.h>
Eric Paris3be25f42009-05-21 17:01:26 -040025#include <linux/fsnotify.h>
Christoph Hellwigfc33a7b2006-01-09 20:52:17 -080026#include <linux/mount.h>
Arjan van de Venefaee192009-01-06 07:20:54 -080027#include <linux/async.h>
Al Virof19d4a82009-06-08 19:50:45 -040028#include <linux/posix_acl.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30/*
31 * This is needed for the following functions:
32 * - inode_has_buffers
33 * - invalidate_inode_buffers
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 * - invalidate_bdev
35 *
36 * FIXME: remove all knowledge of the buffer layer from this file
37 */
38#include <linux/buffer_head.h>
39
40/*
41 * New inode.c implementation.
42 *
43 * This implementation has the basic premise of trying
44 * to be extremely low-overhead and SMP-safe, yet be
45 * simple enough to be "obviously correct".
46 *
47 * Famous last words.
48 */
49
50/* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */
51
52/* #define INODE_PARANOIA 1 */
53/* #define INODE_DEBUG 1 */
54
55/*
56 * Inode lookup is no longer as critical as it used to be:
57 * most of the lookups are going to be through the dcache.
58 */
59#define I_HASHBITS i_hash_shift
60#define I_HASHMASK i_hash_mask
61
Eric Dumazetfa3536c2006-03-26 01:37:24 -080062static unsigned int i_hash_mask __read_mostly;
63static unsigned int i_hash_shift __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65/*
66 * Each inode can be on two separate lists. One is
67 * the hash list of the inode, used for lookups. The
68 * other linked list is the "type" list:
69 * "in_use" - valid inode, i_count > 0, i_nlink > 0
70 * "dirty" - as "in_use" but also dirty
71 * "unused" - valid inode, i_count = 0
72 *
73 * A "dirty" list is maintained for each super block,
74 * allowing for low-overhead inode sync() operations.
75 */
76
77LIST_HEAD(inode_in_use);
78LIST_HEAD(inode_unused);
Eric Dumazetfa3536c2006-03-26 01:37:24 -080079static struct hlist_head *inode_hashtable __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81/*
82 * A simple spinlock to protect the list manipulations.
83 *
84 * NOTE! You also have to own the lock if you change
85 * the i_state of an inode while it is in use..
86 */
87DEFINE_SPINLOCK(inode_lock);
88
89/*
Nick Piggin88e0fbc2009-09-22 16:43:50 -070090 * iprune_sem provides exclusion between the kswapd or try_to_free_pages
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 * icache shrinking path, and the umount path. Without this exclusion,
92 * by the time prune_icache calls iput for the inode whose pages it has
93 * been invalidating, or by the time it calls clear_inode & destroy_inode
94 * from its final dispose_list, the struct super_block they refer to
95 * (for inode->i_sb->s_op) may already have been freed and reused.
Nick Piggin88e0fbc2009-09-22 16:43:50 -070096 *
97 * We make this an rwsem because the fastpath is icache shrinking. In
98 * some cases a filesystem may be doing a significant amount of work in
99 * its inode reclaim code, so this should improve parallelism.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 */
Nick Piggin88e0fbc2009-09-22 16:43:50 -0700101static DECLARE_RWSEM(iprune_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
103/*
104 * Statistics gathering..
105 */
106struct inodes_stat_t inodes_stat;
107
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530108static struct kmem_cache *inode_cachep __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
Joern Engel1c0eeaf2007-10-16 23:30:44 -0700110static void wake_up_inode(struct inode *inode)
111{
112 /*
113 * Prevent speculative execution through spin_unlock(&inode_lock);
114 */
115 smp_mb();
Christoph Hellwigeaff8072009-12-17 14:25:01 +0100116 wake_up_bit(&inode->i_state, __I_NEW);
Joern Engel1c0eeaf2007-10-16 23:30:44 -0700117}
118
David Chinner2cb15992008-10-30 17:32:23 +1100119/**
120 * inode_init_always - perform inode structure intialisation
Randy Dunlap0bc02f32009-01-06 14:41:13 -0800121 * @sb: superblock inode belongs to
122 * @inode: inode to initialise
David Chinner2cb15992008-10-30 17:32:23 +1100123 *
124 * These are initializations that need to be done on every inode
125 * allocation as the fields are not initialised by slab allocation.
126 */
Christoph Hellwig54e34622009-08-07 14:38:25 -0300127int inode_init_always(struct super_block *sb, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128{
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700129 static const struct address_space_operations empty_aops;
Alexey Dobriyan6e1d5dc2009-09-21 17:01:11 -0700130 static const struct inode_operations empty_iops;
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800131 static const struct file_operations empty_fops;
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530132 struct address_space *const mapping = &inode->i_data;
David Chinner2cb15992008-10-30 17:32:23 +1100133
134 inode->i_sb = sb;
135 inode->i_blkbits = sb->s_blocksize_bits;
136 inode->i_flags = 0;
137 atomic_set(&inode->i_count, 1);
138 inode->i_op = &empty_iops;
139 inode->i_fop = &empty_fops;
140 inode->i_nlink = 1;
Al Viro56ff5ef2008-12-09 09:34:39 -0500141 inode->i_uid = 0;
142 inode->i_gid = 0;
David Chinner2cb15992008-10-30 17:32:23 +1100143 atomic_set(&inode->i_writecount, 0);
144 inode->i_size = 0;
145 inode->i_blocks = 0;
146 inode->i_bytes = 0;
147 inode->i_generation = 0;
148#ifdef CONFIG_QUOTA
149 memset(&inode->i_dquot, 0, sizeof(inode->i_dquot));
150#endif
151 inode->i_pipe = NULL;
152 inode->i_bdev = NULL;
153 inode->i_cdev = NULL;
154 inode->i_rdev = 0;
155 inode->dirtied_when = 0;
Mimi Zohar6146f0d2009-02-04 09:06:57 -0500156
157 if (security_inode_alloc(inode))
Christoph Hellwig54e34622009-08-07 14:38:25 -0300158 goto out;
David Chinner2cb15992008-10-30 17:32:23 +1100159 spin_lock_init(&inode->i_lock);
160 lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key);
161
162 mutex_init(&inode->i_mutex);
163 lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key);
164
165 init_rwsem(&inode->i_alloc_sem);
166 lockdep_set_class(&inode->i_alloc_sem, &sb->s_type->i_alloc_sem_key);
167
168 mapping->a_ops = &empty_aops;
169 mapping->host = inode;
170 mapping->flags = 0;
Hugh Dickins3c1d4372009-01-06 14:39:23 -0800171 mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE);
David Chinner2cb15992008-10-30 17:32:23 +1100172 mapping->assoc_mapping = NULL;
173 mapping->backing_dev_info = &default_backing_dev_info;
174 mapping->writeback_index = 0;
175
176 /*
177 * If the block_device provides a backing_dev_info for client
178 * inodes then use that. Otherwise the inode share the bdev's
179 * backing_dev_info.
180 */
181 if (sb->s_bdev) {
182 struct backing_dev_info *bdi;
183
Jens Axboe2c96ce92009-09-15 09:43:56 +0200184 bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
David Chinner2cb15992008-10-30 17:32:23 +1100185 mapping->backing_dev_info = bdi;
186 }
187 inode->i_private = NULL;
188 inode->i_mapping = mapping;
Al Virof19d4a82009-06-08 19:50:45 -0400189#ifdef CONFIG_FS_POSIX_ACL
190 inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
191#endif
David Chinner2cb15992008-10-30 17:32:23 +1100192
Eric Paris3be25f42009-05-21 17:01:26 -0400193#ifdef CONFIG_FSNOTIFY
194 inode->i_fsnotify_mask = 0;
195#endif
196
Christoph Hellwig54e34622009-08-07 14:38:25 -0300197 return 0;
Christoph Hellwig54e34622009-08-07 14:38:25 -0300198out:
199 return -ENOMEM;
David Chinner2cb15992008-10-30 17:32:23 +1100200}
201EXPORT_SYMBOL(inode_init_always);
202
203static struct inode *alloc_inode(struct super_block *sb)
204{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 struct inode *inode;
206
207 if (sb->s_op->alloc_inode)
208 inode = sb->s_op->alloc_inode(sb);
209 else
David Chinner2cb15992008-10-30 17:32:23 +1100210 inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
Christoph Hellwig54e34622009-08-07 14:38:25 -0300212 if (!inode)
213 return NULL;
214
215 if (unlikely(inode_init_always(sb, inode))) {
216 if (inode->i_sb->s_op->destroy_inode)
217 inode->i_sb->s_op->destroy_inode(inode);
218 else
219 kmem_cache_free(inode_cachep, inode);
220 return NULL;
221 }
222
223 return inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224}
225
Christoph Hellwig2e00c972009-08-07 14:38:29 -0300226void __destroy_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227{
Eric Sesterhennb7542f82006-04-02 13:38:18 +0200228 BUG_ON(inode_has_buffers(inode));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 security_inode_free(inode);
Eric Paris3be25f42009-05-21 17:01:26 -0400230 fsnotify_inode_delete(inode);
Al Virof19d4a82009-06-08 19:50:45 -0400231#ifdef CONFIG_FS_POSIX_ACL
232 if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED)
233 posix_acl_release(inode->i_acl);
234 if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED)
235 posix_acl_release(inode->i_default_acl);
236#endif
Christoph Hellwig2e00c972009-08-07 14:38:29 -0300237}
238EXPORT_SYMBOL(__destroy_inode);
239
240void destroy_inode(struct inode *inode)
241{
242 __destroy_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 if (inode->i_sb->s_op->destroy_inode)
244 inode->i_sb->s_op->destroy_inode(inode);
245 else
246 kmem_cache_free(inode_cachep, (inode));
247}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
249/*
250 * These are initializations that only need to be done
251 * once, because the fields are idempotent across use
252 * of the inode, so let the slab aware of that.
253 */
254void inode_init_once(struct inode *inode)
255{
256 memset(inode, 0, sizeof(*inode));
257 INIT_HLIST_NODE(&inode->i_hash);
258 INIT_LIST_HEAD(&inode->i_dentry);
259 INIT_LIST_HEAD(&inode->i_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
Nick Piggin19fd6232008-07-25 19:45:32 -0700261 spin_lock_init(&inode->i_data.tree_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 spin_lock_init(&inode->i_data.i_mmap_lock);
263 INIT_LIST_HEAD(&inode->i_data.private_list);
264 spin_lock_init(&inode->i_data.private_lock);
265 INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap);
266 INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 i_size_ordered_init(inode);
Robert Love0eeca282005-07-12 17:06:03 -0400268#ifdef CONFIG_INOTIFY
269 INIT_LIST_HEAD(&inode->inotify_watches);
Ingo Molnard4f9af92006-03-23 03:00:30 -0800270 mutex_init(&inode->inotify_mutex);
Robert Love0eeca282005-07-12 17:06:03 -0400271#endif
Eric Paris3be25f42009-05-21 17:01:26 -0400272#ifdef CONFIG_FSNOTIFY
273 INIT_HLIST_HEAD(&inode->i_fsnotify_mark_entries);
274#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276EXPORT_SYMBOL(inode_init_once);
277
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700278static void init_once(void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279{
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530280 struct inode *inode = (struct inode *) foo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
Christoph Lametera35afb82007-05-16 22:10:57 -0700282 inode_init_once(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283}
284
285/*
286 * inode_lock must be held
287 */
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530288void __iget(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289{
290 if (atomic_read(&inode->i_count)) {
291 atomic_inc(&inode->i_count);
292 return;
293 }
294 atomic_inc(&inode->i_count);
Joern Engel1c0eeaf2007-10-16 23:30:44 -0700295 if (!(inode->i_state & (I_DIRTY|I_SYNC)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 list_move(&inode->i_list, &inode_in_use);
297 inodes_stat.nr_unused--;
298}
299
300/**
301 * clear_inode - clear an inode
302 * @inode: inode to clear
303 *
304 * This is called by the filesystem to tell us
305 * that the inode is no longer useful. We just
306 * terminate it with extreme prejudice.
307 */
308void clear_inode(struct inode *inode)
309{
310 might_sleep();
311 invalidate_inode_buffers(inode);
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530312
Eric Sesterhennb7542f82006-04-02 13:38:18 +0200313 BUG_ON(inode->i_data.nrpages);
314 BUG_ON(!(inode->i_state & I_FREEING));
315 BUG_ON(inode->i_state & I_CLEAR);
Joern Engel1c0eeaf2007-10-16 23:30:44 -0700316 inode_sync_wait(inode);
Jan Kara9e3509e2009-01-26 16:45:12 +0100317 vfs_dq_drop(inode);
Christoph Hellwigacb0c852007-05-08 00:25:52 -0700318 if (inode->i_sb->s_op->clear_inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 inode->i_sb->s_op->clear_inode(inode);
Theodore Ts'oeaf796e2006-09-27 01:50:48 -0700320 if (S_ISBLK(inode->i_mode) && inode->i_bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 bd_forget(inode);
Theodore Ts'o577c4eb2006-09-27 01:50:49 -0700322 if (S_ISCHR(inode->i_mode) && inode->i_cdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 cd_forget(inode);
324 inode->i_state = I_CLEAR;
325}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326EXPORT_SYMBOL(clear_inode);
327
328/*
329 * dispose_list - dispose of the contents of a local list
330 * @head: the head of the list to free
331 *
332 * Dispose-list gets a local list with local inodes in it, so it doesn't
333 * need to worry about list corruption and SMP locks.
334 */
335static void dispose_list(struct list_head *head)
336{
337 int nr_disposed = 0;
338
339 while (!list_empty(head)) {
340 struct inode *inode;
341
Pavel Emelianovb5e61812007-05-08 00:30:19 -0700342 inode = list_first_entry(head, struct inode, i_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 list_del(&inode->i_list);
344
345 if (inode->i_data.nrpages)
346 truncate_inode_pages(&inode->i_data, 0);
347 clear_inode(inode);
Artem B. Bityuckiy4120db42005-07-12 13:58:12 -0700348
349 spin_lock(&inode_lock);
350 hlist_del_init(&inode->i_hash);
351 list_del_init(&inode->i_sb_list);
352 spin_unlock(&inode_lock);
353
354 wake_up_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 destroy_inode(inode);
356 nr_disposed++;
357 }
358 spin_lock(&inode_lock);
359 inodes_stat.nr_inodes -= nr_disposed;
360 spin_unlock(&inode_lock);
361}
362
363/*
364 * Invalidate all inodes for a device.
365 */
366static int invalidate_list(struct list_head *head, struct list_head *dispose)
367{
368 struct list_head *next;
369 int busy = 0, count = 0;
370
371 next = head->next;
372 for (;;) {
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530373 struct list_head *tmp = next;
374 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
376 /*
377 * We can reschedule here without worrying about the list's
378 * consistency because the per-sb list of inodes must not
Nick Piggin88e0fbc2009-09-22 16:43:50 -0700379 * change during umount anymore, and because iprune_sem keeps
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 * shrink_icache_memory() away.
381 */
382 cond_resched_lock(&inode_lock);
383
384 next = next->next;
385 if (tmp == head)
386 break;
387 inode = list_entry(tmp, struct inode, i_sb_list);
Nick Pigginaabb8fd2009-03-11 13:17:36 -0700388 if (inode->i_state & I_NEW)
389 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 invalidate_inode_buffers(inode);
391 if (!atomic_read(&inode->i_count)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 list_move(&inode->i_list, dispose);
Nick Piggin7ef0d732009-03-12 14:31:38 -0700393 WARN_ON(inode->i_state & I_NEW);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 inode->i_state |= I_FREEING;
395 count++;
396 continue;
397 }
398 busy = 1;
399 }
400 /* only unused inodes may be cached with i_count zero */
401 inodes_stat.nr_unused -= count;
402 return busy;
403}
404
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405/**
406 * invalidate_inodes - discard the inodes on a device
407 * @sb: superblock
408 *
409 * Discard all of the inodes for a given superblock. If the discard
410 * fails because there are busy inodes then a non zero value is returned.
411 * If the discard is successful all the inodes have been discarded.
412 */
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530413int invalidate_inodes(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414{
415 int busy;
416 LIST_HEAD(throw_away);
417
Nick Piggin88e0fbc2009-09-22 16:43:50 -0700418 down_write(&iprune_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 spin_lock(&inode_lock);
Robert Love0eeca282005-07-12 17:06:03 -0400420 inotify_unmount_inodes(&sb->s_inodes);
Eric Paris164bc612009-05-21 17:01:58 -0400421 fsnotify_unmount_inodes(&sb->s_inodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 busy = invalidate_list(&sb->s_inodes, &throw_away);
423 spin_unlock(&inode_lock);
424
425 dispose_list(&throw_away);
Nick Piggin88e0fbc2009-09-22 16:43:50 -0700426 up_write(&iprune_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
428 return busy;
429}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430EXPORT_SYMBOL(invalidate_inodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
432static int can_unuse(struct inode *inode)
433{
434 if (inode->i_state)
435 return 0;
436 if (inode_has_buffers(inode))
437 return 0;
438 if (atomic_read(&inode->i_count))
439 return 0;
440 if (inode->i_data.nrpages)
441 return 0;
442 return 1;
443}
444
445/*
446 * Scan `goal' inodes on the unused list for freeable ones. They are moved to
447 * a temporary list and then are freed outside inode_lock by dispose_list().
448 *
449 * Any inodes which are pinned purely because of attached pagecache have their
450 * pagecache removed. We expect the final iput() on that inode to add it to
451 * the front of the inode_unused list. So look for it there and if the
452 * inode is still freeable, proceed. The right inode is found 99.9% of the
453 * time in testing on a 4-way.
454 *
455 * If the inode has metadata buffers attached to mapping->private_list then
456 * try to remove them.
457 */
458static void prune_icache(int nr_to_scan)
459{
460 LIST_HEAD(freeable);
461 int nr_pruned = 0;
462 int nr_scanned;
463 unsigned long reap = 0;
464
Nick Piggin88e0fbc2009-09-22 16:43:50 -0700465 down_read(&iprune_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 spin_lock(&inode_lock);
467 for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) {
468 struct inode *inode;
469
470 if (list_empty(&inode_unused))
471 break;
472
473 inode = list_entry(inode_unused.prev, struct inode, i_list);
474
475 if (inode->i_state || atomic_read(&inode->i_count)) {
476 list_move(&inode->i_list, &inode_unused);
477 continue;
478 }
479 if (inode_has_buffers(inode) || inode->i_data.nrpages) {
480 __iget(inode);
481 spin_unlock(&inode_lock);
482 if (remove_inode_buffers(inode))
Andrew Mortonfc0ecff2007-02-10 01:45:39 -0800483 reap += invalidate_mapping_pages(&inode->i_data,
484 0, -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 iput(inode);
486 spin_lock(&inode_lock);
487
488 if (inode != list_entry(inode_unused.next,
489 struct inode, i_list))
490 continue; /* wrong inode or list_empty */
491 if (!can_unuse(inode))
492 continue;
493 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 list_move(&inode->i_list, &freeable);
Nick Piggin7ef0d732009-03-12 14:31:38 -0700495 WARN_ON(inode->i_state & I_NEW);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 inode->i_state |= I_FREEING;
497 nr_pruned++;
498 }
499 inodes_stat.nr_unused -= nr_pruned;
Christoph Lameterf8891e52006-06-30 01:55:45 -0700500 if (current_is_kswapd())
501 __count_vm_events(KSWAPD_INODESTEAL, reap);
502 else
503 __count_vm_events(PGINODESTEAL, reap);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 spin_unlock(&inode_lock);
505
506 dispose_list(&freeable);
Nick Piggin88e0fbc2009-09-22 16:43:50 -0700507 up_read(&iprune_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508}
509
510/*
511 * shrink_icache_memory() will attempt to reclaim some unused inodes. Here,
512 * "unused" means that no dentries are referring to the inodes: the files are
513 * not open and the dcache references to those inodes have already been
514 * reclaimed.
515 *
516 * This function is passed the number of inodes to scan, and it returns the
517 * total number of remaining possibly-reclaimable inodes.
518 */
Al Viro27496a82005-10-21 03:20:48 -0400519static int shrink_icache_memory(int nr, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520{
521 if (nr) {
522 /*
523 * Nasty deadlock avoidance. We may hold various FS locks,
524 * and we don't want to recurse into the FS that called us
525 * in clear_inode() and friends..
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530526 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 if (!(gfp_mask & __GFP_FS))
528 return -1;
529 prune_icache(nr);
530 }
531 return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
532}
533
Rusty Russell8e1f9362007-07-17 04:03:17 -0700534static struct shrinker icache_shrinker = {
535 .shrink = shrink_icache_memory,
536 .seeks = DEFAULT_SEEKS,
537};
538
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539static void __wait_on_freeing_inode(struct inode *inode);
540/*
541 * Called with the inode lock held.
542 * NOTE: we are not increasing the inode-refcount, you must call __iget()
543 * by hand after calling find_inode now! This simplifies iunique and won't
544 * add any additional branch in the common code.
545 */
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530546static struct inode *find_inode(struct super_block *sb,
547 struct hlist_head *head,
548 int (*test)(struct inode *, void *),
549 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550{
551 struct hlist_node *node;
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530552 struct inode *inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553
554repeat:
Matthias Kaehlckec5c8be32008-04-29 00:59:40 -0700555 hlist_for_each_entry(inode, node, head, i_hash) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 if (inode->i_sb != sb)
557 continue;
558 if (!test(inode, data))
559 continue;
Alexander Viro991114c2005-06-23 00:09:01 -0700560 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 __wait_on_freeing_inode(inode);
562 goto repeat;
563 }
564 break;
565 }
566 return node ? inode : NULL;
567}
568
569/*
570 * find_inode_fast is the fast path version of find_inode, see the comment at
571 * iget_locked for details.
572 */
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530573static struct inode *find_inode_fast(struct super_block *sb,
574 struct hlist_head *head, unsigned long ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575{
576 struct hlist_node *node;
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530577 struct inode *inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
579repeat:
Matthias Kaehlckec5c8be32008-04-29 00:59:40 -0700580 hlist_for_each_entry(inode, node, head, i_hash) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 if (inode->i_ino != ino)
582 continue;
583 if (inode->i_sb != sb)
584 continue;
Alexander Viro991114c2005-06-23 00:09:01 -0700585 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 __wait_on_freeing_inode(inode);
587 goto repeat;
588 }
589 break;
590 }
591 return node ? inode : NULL;
592}
593
David Chinner8290c352008-10-30 17:35:24 +1100594static unsigned long hash(struct super_block *sb, unsigned long hashval)
595{
596 unsigned long tmp;
597
598 tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
599 L1_CACHE_BYTES;
600 tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS);
601 return tmp & I_HASHMASK;
602}
603
604static inline void
605__inode_add_to_lists(struct super_block *sb, struct hlist_head *head,
606 struct inode *inode)
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 if (head)
612 hlist_add_head(&inode->i_hash, head);
613}
614
615/**
616 * inode_add_to_lists - add a new inode to relevant lists
Randy Dunlap0bc02f32009-01-06 14:41:13 -0800617 * @sb: superblock inode belongs to
618 * @inode: inode to mark in use
David Chinner8290c352008-10-30 17:35:24 +1100619 *
620 * When an inode is allocated it needs to be accounted for, added to the in use
621 * list, the owning superblock and the inode hash. This needs to be done under
622 * the inode_lock, so export a function to do this rather than the inode lock
623 * itself. We calculate the hash list to add to here so it is all internal
624 * which requires the caller to have already set up the inode number in the
625 * inode to add.
626 */
627void inode_add_to_lists(struct super_block *sb, struct inode *inode)
628{
629 struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino);
630
631 spin_lock(&inode_lock);
632 __inode_add_to_lists(sb, head, inode);
633 spin_unlock(&inode_lock);
634}
635EXPORT_SYMBOL_GPL(inode_add_to_lists);
636
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637/**
638 * new_inode - obtain an inode
639 * @sb: superblock
640 *
Mel Gorman769848c2007-07-17 04:03:05 -0700641 * Allocates a new inode for given superblock. The default gfp_mask
Hugh Dickins3c1d4372009-01-06 14:39:23 -0800642 * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE.
Mel Gorman769848c2007-07-17 04:03:05 -0700643 * If HIGHMEM pages are unsuitable or it is known that pages allocated
644 * for the page cache are not reclaimable or migratable,
645 * mapping_set_gfp_mask() must be called with suitable flags on the
646 * newly created inode's mapping
647 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 */
649struct inode *new_inode(struct super_block *sb)
650{
Jeff Layton866b04f2007-05-08 00:32:29 -0700651 /*
652 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
653 * error if st_ino won't fit in target struct field. Use 32bit counter
654 * here to attempt to avoid that.
655 */
656 static unsigned int last_ino;
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530657 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658
659 spin_lock_prefetch(&inode_lock);
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530660
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 inode = alloc_inode(sb);
662 if (inode) {
663 spin_lock(&inode_lock);
David Chinner8290c352008-10-30 17:35:24 +1100664 __inode_add_to_lists(sb, NULL, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 inode->i_ino = ++last_ino;
666 inode->i_state = 0;
667 spin_unlock(&inode_lock);
668 }
669 return inode;
670}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671EXPORT_SYMBOL(new_inode);
672
673void unlock_new_inode(struct inode *inode)
674{
Peter Zijlstra14358e62007-10-14 01:38:33 +0200675#ifdef CONFIG_DEBUG_LOCK_ALLOC
Peter Zijlstra1e89a5e2007-10-16 06:47:54 +0200676 if (inode->i_mode & S_IFDIR) {
677 struct file_system_type *type = inode->i_sb->s_type;
678
Jan Kara9a7aa122009-06-04 15:26:49 +0200679 /* Set new key only if filesystem hasn't already changed it */
680 if (!lockdep_match_class(&inode->i_mutex,
681 &type->i_mutex_key)) {
682 /*
683 * ensure nobody is actually holding i_mutex
684 */
685 mutex_destroy(&inode->i_mutex);
686 mutex_init(&inode->i_mutex);
687 lockdep_set_class(&inode->i_mutex,
688 &type->i_mutex_dir_key);
689 }
Peter Zijlstra1e89a5e2007-10-16 06:47:54 +0200690 }
Peter Zijlstra14358e62007-10-14 01:38:33 +0200691#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 /*
Christoph Hellwigeaff8072009-12-17 14:25:01 +0100693 * This is special! We do not need the spinlock when clearing I_NEW,
Jan Kara580be082009-09-21 17:01:06 -0700694 * because we're guaranteed that nobody else tries to do anything about
695 * the state of the inode when it is locked, as we just created it (so
Christoph Hellwigeaff8072009-12-17 14:25:01 +0100696 * there can be no old holders that haven't tested I_NEW).
Jan Kara580be082009-09-21 17:01:06 -0700697 * However we must emit the memory barrier so that other CPUs reliably
Christoph Hellwigeaff8072009-12-17 14:25:01 +0100698 * see the clearing of I_NEW after the other inode initialisation has
Jan Kara580be082009-09-21 17:01:06 -0700699 * completed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 */
Jan Kara580be082009-09-21 17:01:06 -0700701 smp_mb();
Christoph Hellwigeaff8072009-12-17 14:25:01 +0100702 WARN_ON(!(inode->i_state & I_NEW));
703 inode->i_state &= ~I_NEW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 wake_up_inode(inode);
705}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706EXPORT_SYMBOL(unlock_new_inode);
707
708/*
709 * This is called without the inode lock held.. Be careful.
710 *
711 * We no longer cache the sb_flags in i_flags - see fs.h
712 * -- rmk@arm.uk.linux.org
713 */
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530714static struct inode *get_new_inode(struct super_block *sb,
715 struct hlist_head *head,
716 int (*test)(struct inode *, void *),
717 int (*set)(struct inode *, void *),
718 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719{
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530720 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721
722 inode = alloc_inode(sb);
723 if (inode) {
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530724 struct inode *old;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725
726 spin_lock(&inode_lock);
727 /* We released the lock, so.. */
728 old = find_inode(sb, head, test, data);
729 if (!old) {
730 if (set(inode, data))
731 goto set_failed;
732
David Chinner8290c352008-10-30 17:35:24 +1100733 __inode_add_to_lists(sb, head, inode);
Christoph Hellwigeaff8072009-12-17 14:25:01 +0100734 inode->i_state = I_NEW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 spin_unlock(&inode_lock);
736
737 /* Return the locked inode with I_NEW set, the
738 * caller is responsible for filling in the contents
739 */
740 return inode;
741 }
742
743 /*
744 * Uhhuh, somebody else created the same inode under
745 * us. Use the old inode instead of the one we just
746 * allocated.
747 */
748 __iget(old);
749 spin_unlock(&inode_lock);
750 destroy_inode(inode);
751 inode = old;
752 wait_on_inode(inode);
753 }
754 return inode;
755
756set_failed:
757 spin_unlock(&inode_lock);
758 destroy_inode(inode);
759 return NULL;
760}
761
762/*
763 * get_new_inode_fast is the fast path version of get_new_inode, see the
764 * comment at iget_locked for details.
765 */
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530766static struct inode *get_new_inode_fast(struct super_block *sb,
767 struct hlist_head *head, unsigned long ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768{
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530769 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770
771 inode = alloc_inode(sb);
772 if (inode) {
Manish Katiyar6b3304b2009-03-31 19:35:54 +0530773 struct inode *old;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774
775 spin_lock(&inode_lock);
776 /* We released the lock, so.. */
777 old = find_inode_fast(sb, head, ino);
778 if (!old) {
779 inode->i_ino = ino;
David Chinner8290c352008-10-30 17:35:24 +1100780 __inode_add_to_lists(sb, head, inode);
Christoph Hellwigeaff8072009-12-17 14:25:01 +0100781 inode->i_state = I_NEW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 spin_unlock(&inode_lock);
783
784 /* Return the locked inode with I_NEW set, the
785 * caller is responsible for filling in the contents
786 */
787 return inode;
788 }
789
790 /*
791 * Uhhuh, somebody else created the same inode under
792 * us. Use the old inode instead of the one we just
793 * allocated.
794 */
795 __iget(old);
796 spin_unlock(&inode_lock);
797 destroy_inode(inode);
798 inode = old;
799 wait_on_inode(inode);
800 }
801 return inode;
802}
803
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804/**
805 * iunique - get a unique inode number
806 * @sb: superblock
807 * @max_reserved: highest reserved inode number
808 *
809 * Obtain an inode number that is unique on the system for a given
810 * superblock. This is used by file systems that have no natural
811 * permanent inode numbering system. An inode number is returned that
812 * is higher than the reserved limit but unique.
813 *
814 * BUGS:
815 * With a large number of inodes live on the file system this function
816 * currently becomes quite slow.
817 */
818ino_t iunique(struct super_block *sb, ino_t max_reserved)
819{
Jeff Layton866b04f2007-05-08 00:32:29 -0700820 /*
821 * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
822 * error if st_ino won't fit in target struct field. Use 32bit counter
823 * here to attempt to avoid that.
824 */
825 static unsigned int counter;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 struct inode *inode;
Jeffrey Layton3361c7b2007-05-08 00:29:48 -0700827 struct hlist_head *head;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 ino_t res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829
Jeffrey Layton3361c7b2007-05-08 00:29:48 -0700830 spin_lock(&inode_lock);
831 do {
832 if (counter <= max_reserved)
833 counter = max_reserved + 1;
834 res = counter++;
835 head = inode_hashtable + hash(sb, res);
836 inode = find_inode_fast(sb, head, res);
837 } while (inode != NULL);
838 spin_unlock(&inode_lock);
839
840 return res;
841}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842EXPORT_SYMBOL(iunique);
843
844struct inode *igrab(struct inode *inode)
845{
846 spin_lock(&inode_lock);
Jan Blunck4a3b0a42007-02-10 01:44:59 -0800847 if (!(inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 __iget(inode);
849 else
850 /*
851 * Handle the case where s_op->clear_inode is not been
852 * called yet, and somebody is calling igrab
853 * while the inode is getting freed.
854 */
855 inode = NULL;
856 spin_unlock(&inode_lock);
857 return inode;
858}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859EXPORT_SYMBOL(igrab);
860
861/**
862 * ifind - internal function, you want ilookup5() or iget5().
863 * @sb: super block of file system to search
864 * @head: the head of the list to search
865 * @test: callback used for comparisons between inodes
866 * @data: opaque data pointer to pass to @test
Anton Altaparmakov88bd5122005-07-13 01:10:44 -0700867 * @wait: if true wait for the inode to be unlocked, if false do not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 *
869 * ifind() searches for the inode specified by @data in the inode
870 * cache. This is a generalized version of ifind_fast() for file systems where
871 * the inode number is not sufficient for unique identification of an inode.
872 *
873 * If the inode is in the cache, the inode is returned with an incremented
874 * reference count.
875 *
876 * Otherwise NULL is returned.
877 *
878 * Note, @test is called with the inode_lock held, so can't sleep.
879 */
Matt Mackall5d2bea42006-01-08 01:05:21 -0800880static struct inode *ifind(struct super_block *sb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 struct hlist_head *head, int (*test)(struct inode *, void *),
Anton Altaparmakov88bd5122005-07-13 01:10:44 -0700882 void *data, const int wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883{
884 struct inode *inode;
885
886 spin_lock(&inode_lock);
887 inode = find_inode(sb, head, test, data);
888 if (inode) {
889 __iget(inode);
890 spin_unlock(&inode_lock);
Anton Altaparmakov88bd5122005-07-13 01:10:44 -0700891 if (likely(wait))
892 wait_on_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 return inode;
894 }
895 spin_unlock(&inode_lock);
896 return NULL;
897}
898
899/**
900 * ifind_fast - internal function, you want ilookup() or iget().
901 * @sb: super block of file system to search
902 * @head: head of the list to search
903 * @ino: inode number to search for
904 *
905 * ifind_fast() searches for the inode @ino in the inode cache. This is for
906 * file systems where the inode number is sufficient for unique identification
907 * of an inode.
908 *
909 * If the inode is in the cache, the inode is returned with an incremented
910 * reference count.
911 *
912 * Otherwise NULL is returned.
913 */
Matt Mackall5d2bea42006-01-08 01:05:21 -0800914static struct inode *ifind_fast(struct super_block *sb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 struct hlist_head *head, unsigned long ino)
916{
917 struct inode *inode;
918
919 spin_lock(&inode_lock);
920 inode = find_inode_fast(sb, head, ino);
921 if (inode) {
922 __iget(inode);
923 spin_unlock(&inode_lock);
924 wait_on_inode(inode);
925 return inode;
926 }
927 spin_unlock(&inode_lock);
928 return NULL;
929}
930
931/**
Anton Altaparmakov88bd5122005-07-13 01:10:44 -0700932 * ilookup5_nowait - search for an inode in the inode cache
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 * @sb: super block of file system to search
934 * @hashval: hash value (usually inode number) to search for
935 * @test: callback used for comparisons between inodes
936 * @data: opaque data pointer to pass to @test
937 *
938 * ilookup5() uses ifind() to search for the inode specified by @hashval and
939 * @data in the inode cache. This is a generalized version of ilookup() for
940 * file systems where the inode number is not sufficient for unique
941 * identification of an inode.
942 *
943 * If the inode is in the cache, the inode is returned with an incremented
Anton Altaparmakov88bd5122005-07-13 01:10:44 -0700944 * reference count. Note, the inode lock is not waited upon so you have to be
945 * very careful what you do with the returned inode. You probably should be
946 * using ilookup5() instead.
947 *
948 * Otherwise NULL is returned.
949 *
950 * Note, @test is called with the inode_lock held, so can't sleep.
951 */
952struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval,
953 int (*test)(struct inode *, void *), void *data)
954{
955 struct hlist_head *head = inode_hashtable + hash(sb, hashval);
956
957 return ifind(sb, head, test, data, 0);
958}
Anton Altaparmakov88bd5122005-07-13 01:10:44 -0700959EXPORT_SYMBOL(ilookup5_nowait);
960
961/**
962 * ilookup5 - search for an inode in the inode cache
963 * @sb: super block of file system to search
964 * @hashval: hash value (usually inode number) to search for
965 * @test: callback used for comparisons between inodes
966 * @data: opaque data pointer to pass to @test
967 *
968 * ilookup5() uses ifind() to search for the inode specified by @hashval and
969 * @data in the inode cache. This is a generalized version of ilookup() for
970 * file systems where the inode number is not sufficient for unique
971 * identification of an inode.
972 *
973 * If the inode is in the cache, the inode lock is waited upon and the inode is
974 * returned with an incremented reference count.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 *
976 * Otherwise NULL is returned.
977 *
978 * Note, @test is called with the inode_lock held, so can't sleep.
979 */
980struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
981 int (*test)(struct inode *, void *), void *data)
982{
983 struct hlist_head *head = inode_hashtable + hash(sb, hashval);
984
Anton Altaparmakov88bd5122005-07-13 01:10:44 -0700985 return ifind(sb, head, test, data, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987EXPORT_SYMBOL(ilookup5);
988
989/**
990 * ilookup - search for an inode in the inode cache
991 * @sb: super block of file system to search
992 * @ino: inode number to search for
993 *
994 * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache.
995 * This is for file systems where the inode number is sufficient for unique
996 * identification of an inode.
997 *
998 * If the inode is in the cache, the inode is returned with an incremented
999 * reference count.
1000 *
1001 * Otherwise NULL is returned.
1002 */
1003struct inode *ilookup(struct super_block *sb, unsigned long ino)
1004{
1005 struct hlist_head *head = inode_hashtable + hash(sb, ino);
1006
1007 return ifind_fast(sb, head, ino);
1008}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009EXPORT_SYMBOL(ilookup);
1010
1011/**
1012 * iget5_locked - obtain an inode from a mounted file system
1013 * @sb: super block of file system
1014 * @hashval: hash value (usually inode number) to get
1015 * @test: callback used for comparisons between inodes
1016 * @set: callback used to initialize a new struct inode
1017 * @data: opaque data pointer to pass to @test and @set
1018 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 * iget5_locked() uses ifind() to search for the inode specified by @hashval
1020 * and @data in the inode cache and if present it is returned with an increased
1021 * reference count. This is a generalized version of iget_locked() for file
1022 * systems where the inode number is not sufficient for unique identification
1023 * of an inode.
1024 *
1025 * If the inode is not in cache, get_new_inode() is called to allocate a new
1026 * inode and this is returned locked, hashed, and with the I_NEW flag set. The
1027 * file system gets to fill it in before unlocking it via unlock_new_inode().
1028 *
1029 * Note both @test and @set are called with the inode_lock held, so can't sleep.
1030 */
1031struct inode *iget5_locked(struct super_block *sb, unsigned long hashval,
1032 int (*test)(struct inode *, void *),
1033 int (*set)(struct inode *, void *), void *data)
1034{
1035 struct hlist_head *head = inode_hashtable + hash(sb, hashval);
1036 struct inode *inode;
1037
Anton Altaparmakov88bd5122005-07-13 01:10:44 -07001038 inode = ifind(sb, head, test, data, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 if (inode)
1040 return inode;
1041 /*
1042 * get_new_inode() will do the right thing, re-trying the search
1043 * in case it had to block at any point.
1044 */
1045 return get_new_inode(sb, head, test, set, data);
1046}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047EXPORT_SYMBOL(iget5_locked);
1048
1049/**
1050 * iget_locked - obtain an inode from a mounted file system
1051 * @sb: super block of file system
1052 * @ino: inode number to get
1053 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 * iget_locked() uses ifind_fast() to search for the inode specified by @ino in
1055 * the inode cache and if present it is returned with an increased reference
1056 * count. This is for file systems where the inode number is sufficient for
1057 * unique identification of an inode.
1058 *
1059 * If the inode is not in cache, get_new_inode_fast() is called to allocate a
1060 * new inode and this is returned locked, hashed, and with the I_NEW flag set.
1061 * The file system gets to fill it in before unlocking it via
1062 * unlock_new_inode().
1063 */
1064struct inode *iget_locked(struct super_block *sb, unsigned long ino)
1065{
1066 struct hlist_head *head = inode_hashtable + hash(sb, ino);
1067 struct inode *inode;
1068
1069 inode = ifind_fast(sb, head, ino);
1070 if (inode)
1071 return inode;
1072 /*
1073 * get_new_inode_fast() will do the right thing, re-trying the search
1074 * in case it had to block at any point.
1075 */
1076 return get_new_inode_fast(sb, head, ino);
1077}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078EXPORT_SYMBOL(iget_locked);
1079
Al Viro261bca82008-12-30 01:48:21 -05001080int insert_inode_locked(struct inode *inode)
1081{
1082 struct super_block *sb = inode->i_sb;
1083 ino_t ino = inode->i_ino;
1084 struct hlist_head *head = inode_hashtable + hash(sb, ino);
Al Viro261bca82008-12-30 01:48:21 -05001085
Christoph Hellwigeaff8072009-12-17 14:25:01 +01001086 inode->i_state |= I_NEW;
Al Viro261bca82008-12-30 01:48:21 -05001087 while (1) {
Al Viro72a43d62009-05-13 19:13:40 +01001088 struct hlist_node *node;
1089 struct inode *old = NULL;
Al Viro261bca82008-12-30 01:48:21 -05001090 spin_lock(&inode_lock);
Al Viro72a43d62009-05-13 19:13:40 +01001091 hlist_for_each_entry(old, node, head, i_hash) {
1092 if (old->i_ino != ino)
1093 continue;
1094 if (old->i_sb != sb)
1095 continue;
1096 if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE))
1097 continue;
1098 break;
1099 }
1100 if (likely(!node)) {
Al Viro261bca82008-12-30 01:48:21 -05001101 hlist_add_head(&inode->i_hash, head);
1102 spin_unlock(&inode_lock);
1103 return 0;
1104 }
1105 __iget(old);
1106 spin_unlock(&inode_lock);
1107 wait_on_inode(old);
1108 if (unlikely(!hlist_unhashed(&old->i_hash))) {
1109 iput(old);
1110 return -EBUSY;
1111 }
1112 iput(old);
1113 }
1114}
Al Viro261bca82008-12-30 01:48:21 -05001115EXPORT_SYMBOL(insert_inode_locked);
1116
1117int insert_inode_locked4(struct inode *inode, unsigned long hashval,
1118 int (*test)(struct inode *, void *), void *data)
1119{
1120 struct super_block *sb = inode->i_sb;
1121 struct hlist_head *head = inode_hashtable + hash(sb, hashval);
Al Viro261bca82008-12-30 01:48:21 -05001122
Christoph Hellwigeaff8072009-12-17 14:25:01 +01001123 inode->i_state |= I_NEW;
Al Viro261bca82008-12-30 01:48:21 -05001124
1125 while (1) {
Al Viro72a43d62009-05-13 19:13:40 +01001126 struct hlist_node *node;
1127 struct inode *old = NULL;
1128
Al Viro261bca82008-12-30 01:48:21 -05001129 spin_lock(&inode_lock);
Al Viro72a43d62009-05-13 19:13:40 +01001130 hlist_for_each_entry(old, node, head, i_hash) {
1131 if (old->i_sb != sb)
1132 continue;
1133 if (!test(old, data))
1134 continue;
1135 if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE))
1136 continue;
1137 break;
1138 }
1139 if (likely(!node)) {
Al Viro261bca82008-12-30 01:48:21 -05001140 hlist_add_head(&inode->i_hash, head);
1141 spin_unlock(&inode_lock);
1142 return 0;
1143 }
1144 __iget(old);
1145 spin_unlock(&inode_lock);
1146 wait_on_inode(old);
1147 if (unlikely(!hlist_unhashed(&old->i_hash))) {
1148 iput(old);
1149 return -EBUSY;
1150 }
1151 iput(old);
1152 }
1153}
Al Viro261bca82008-12-30 01:48:21 -05001154EXPORT_SYMBOL(insert_inode_locked4);
1155
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156/**
1157 * __insert_inode_hash - hash an inode
1158 * @inode: unhashed inode
1159 * @hashval: unsigned long value used to locate this object in the
1160 * inode_hashtable.
1161 *
1162 * Add an inode to the inode hash for this superblock.
1163 */
1164void __insert_inode_hash(struct inode *inode, unsigned long hashval)
1165{
1166 struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval);
1167 spin_lock(&inode_lock);
1168 hlist_add_head(&inode->i_hash, head);
1169 spin_unlock(&inode_lock);
1170}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171EXPORT_SYMBOL(__insert_inode_hash);
1172
1173/**
1174 * remove_inode_hash - remove an inode from the hash
1175 * @inode: inode to unhash
1176 *
1177 * Remove an inode from the superblock.
1178 */
1179void remove_inode_hash(struct inode *inode)
1180{
1181 spin_lock(&inode_lock);
1182 hlist_del_init(&inode->i_hash);
1183 spin_unlock(&inode_lock);
1184}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185EXPORT_SYMBOL(remove_inode_hash);
1186
1187/*
1188 * Tell the filesystem that this inode is no longer of any interest and should
1189 * be completely destroyed.
1190 *
1191 * We leave the inode in the inode hash table until *after* the filesystem's
1192 * ->delete_inode completes. This ensures that an iget (such as nfsd might
1193 * instigate) will always find up-to-date information either in the hash or on
1194 * disk.
1195 *
1196 * I_FREEING is set so that no-one will take a new reference to the inode while
1197 * it is being deleted.
1198 */
Arjan van de Venb32714b2009-01-09 07:04:15 -08001199void generic_delete_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200{
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -08001201 const struct super_operations *op = inode->i_sb->s_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202
Arjan van de Venb32714b2009-01-09 07:04:15 -08001203 list_del_init(&inode->i_list);
1204 list_del_init(&inode->i_sb_list);
Nick Piggin7ef0d732009-03-12 14:31:38 -07001205 WARN_ON(inode->i_state & I_NEW);
Arjan van de Venb32714b2009-01-09 07:04:15 -08001206 inode->i_state |= I_FREEING;
1207 inodes_stat.nr_inodes--;
1208 spin_unlock(&inode_lock);
1209
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210 security_inode_delete(inode);
1211
1212 if (op->delete_inode) {
1213 void (*delete)(struct inode *) = op->delete_inode;
1214 if (!is_bad_inode(inode))
Jan Kara9e3509e2009-01-26 16:45:12 +01001215 vfs_dq_init(inode);
Mark Fashehe85b5652005-09-09 13:01:29 -07001216 /* Filesystems implementing their own
1217 * s_op->delete_inode are required to call
1218 * truncate_inode_pages and clear_inode()
1219 * internally */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220 delete(inode);
Mark Fashehe85b5652005-09-09 13:01:29 -07001221 } else {
1222 truncate_inode_pages(&inode->i_data, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223 clear_inode(inode);
Mark Fashehe85b5652005-09-09 13:01:29 -07001224 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 spin_lock(&inode_lock);
1226 hlist_del_init(&inode->i_hash);
1227 spin_unlock(&inode_lock);
1228 wake_up_inode(inode);
Eric Sesterhennb7542f82006-04-02 13:38:18 +02001229 BUG_ON(inode->i_state != I_CLEAR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 destroy_inode(inode);
1231}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232EXPORT_SYMBOL(generic_delete_inode);
1233
Jan Kara22fe40422009-09-18 13:05:44 -07001234/**
1235 * generic_detach_inode - remove inode from inode lists
1236 * @inode: inode to remove
1237 *
1238 * Remove inode from inode lists, write it if it's dirty. This is just an
1239 * internal VFS helper exported for hugetlbfs. Do not use!
1240 *
1241 * Returns 1 if inode should be completely destroyed.
1242 */
1243int generic_detach_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244{
1245 struct super_block *sb = inode->i_sb;
1246
1247 if (!hlist_unhashed(&inode->i_hash)) {
Joern Engel1c0eeaf2007-10-16 23:30:44 -07001248 if (!(inode->i_state & (I_DIRTY|I_SYNC)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249 list_move(&inode->i_list, &inode_unused);
1250 inodes_stat.nr_unused++;
Christoph Hellwigacb0c852007-05-08 00:25:52 -07001251 if (sb->s_flags & MS_ACTIVE) {
Alexander Viro991114c2005-06-23 00:09:01 -07001252 spin_unlock(&inode_lock);
Jan Kara22fe40422009-09-18 13:05:44 -07001253 return 0;
Alexander Viro991114c2005-06-23 00:09:01 -07001254 }
Nick Piggin7ef0d732009-03-12 14:31:38 -07001255 WARN_ON(inode->i_state & I_NEW);
Alexander Viro991114c2005-06-23 00:09:01 -07001256 inode->i_state |= I_WILL_FREE;
1257 spin_unlock(&inode_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 write_inode_now(inode, 1);
1259 spin_lock(&inode_lock);
Nick Piggin7ef0d732009-03-12 14:31:38 -07001260 WARN_ON(inode->i_state & I_NEW);
Alexander Viro991114c2005-06-23 00:09:01 -07001261 inode->i_state &= ~I_WILL_FREE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 inodes_stat.nr_unused--;
1263 hlist_del_init(&inode->i_hash);
1264 }
1265 list_del_init(&inode->i_list);
1266 list_del_init(&inode->i_sb_list);
Nick Piggin7ef0d732009-03-12 14:31:38 -07001267 WARN_ON(inode->i_state & I_NEW);
Alexander Viro991114c2005-06-23 00:09:01 -07001268 inode->i_state |= I_FREEING;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 inodes_stat.nr_inodes--;
1270 spin_unlock(&inode_lock);
Jan Kara22fe40422009-09-18 13:05:44 -07001271 return 1;
1272}
1273EXPORT_SYMBOL_GPL(generic_detach_inode);
1274
1275static void generic_forget_inode(struct inode *inode)
1276{
1277 if (!generic_detach_inode(inode))
1278 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 if (inode->i_data.nrpages)
1280 truncate_inode_pages(&inode->i_data, 0);
1281 clear_inode(inode);
Andrea Arcangeli7f04c262005-10-30 15:03:05 -08001282 wake_up_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 destroy_inode(inode);
1284}
1285
1286/*
1287 * Normal UNIX filesystem behaviour: delete the
1288 * inode when the usage count drops to zero, and
1289 * i_nlink is zero.
1290 */
Mark Fashehcb2c0232005-07-07 17:56:03 -07001291void generic_drop_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292{
1293 if (!inode->i_nlink)
1294 generic_delete_inode(inode);
1295 else
1296 generic_forget_inode(inode);
1297}
Mark Fashehcb2c0232005-07-07 17:56:03 -07001298EXPORT_SYMBOL_GPL(generic_drop_inode);
1299
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300/*
1301 * Called when we're dropping the last reference
Manish Katiyar6b3304b2009-03-31 19:35:54 +05301302 * to an inode.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 *
1304 * Call the FS "drop()" function, defaulting to
1305 * the legacy UNIX filesystem behaviour..
1306 *
1307 * NOTE! NOTE! NOTE! We're called with the inode lock
1308 * held, and the drop function is supposed to release
1309 * the lock!
1310 */
1311static inline void iput_final(struct inode *inode)
1312{
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -08001313 const struct super_operations *op = inode->i_sb->s_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 void (*drop)(struct inode *) = generic_drop_inode;
1315
1316 if (op && op->drop_inode)
1317 drop = op->drop_inode;
1318 drop(inode);
1319}
1320
1321/**
Manish Katiyar6b3304b2009-03-31 19:35:54 +05301322 * iput - put an inode
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 * @inode: inode to put
1324 *
1325 * Puts an inode, dropping its usage count. If the inode use count hits
1326 * zero, the inode is then freed and may also be destroyed.
1327 *
1328 * Consequently, iput() can sleep.
1329 */
1330void iput(struct inode *inode)
1331{
1332 if (inode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333 BUG_ON(inode->i_state == I_CLEAR);
1334
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335 if (atomic_dec_and_lock(&inode->i_count, &inode_lock))
1336 iput_final(inode);
1337 }
1338}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339EXPORT_SYMBOL(iput);
1340
1341/**
1342 * bmap - find a block number in a file
1343 * @inode: inode of file
1344 * @block: block to find
1345 *
1346 * Returns the block number on the device holding the inode that
1347 * is the disk block number for the block of the file requested.
1348 * That is, asked for block 4 of inode 1 the function will return the
Manish Katiyar6b3304b2009-03-31 19:35:54 +05301349 * disk block relative to the disk start that holds that block of the
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350 * file.
1351 */
Manish Katiyar6b3304b2009-03-31 19:35:54 +05301352sector_t bmap(struct inode *inode, sector_t block)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353{
1354 sector_t res = 0;
1355 if (inode->i_mapping->a_ops->bmap)
1356 res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block);
1357 return res;
1358}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359EXPORT_SYMBOL(bmap);
1360
Matthew Garrett11ff6f052009-03-26 17:32:14 +00001361/*
1362 * With relative atime, only update atime if the previous atime is
1363 * earlier than either the ctime or mtime or if at least a day has
1364 * passed since the last atime update.
1365 */
1366static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
1367 struct timespec now)
1368{
1369
1370 if (!(mnt->mnt_flags & MNT_RELATIME))
1371 return 1;
1372 /*
1373 * Is mtime younger than atime? If yes, update atime:
1374 */
1375 if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0)
1376 return 1;
1377 /*
1378 * Is ctime younger than atime? If yes, update atime:
1379 */
1380 if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0)
1381 return 1;
1382
1383 /*
1384 * Is the previous atime value older than a day? If yes,
1385 * update atime:
1386 */
1387 if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60)
1388 return 1;
1389 /*
1390 * Good, we can skip the atime update:
1391 */
1392 return 0;
1393}
1394
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395/**
Christoph Hellwig869243a2006-01-09 20:52:03 -08001396 * touch_atime - update the access time
1397 * @mnt: mount the inode is accessed on
Martin Waitz7045f372006-02-01 03:06:57 -08001398 * @dentry: dentry accessed
Linus Torvalds1da177e2005-04-16 15:20:36 -07001399 *
1400 * Update the accessed time on an inode and mark it for writeback.
1401 * This function automatically handles read only file systems and media,
1402 * as well as the "noatime" flag and inode specific "noatime" markers.
1403 */
Christoph Hellwig869243a2006-01-09 20:52:03 -08001404void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405{
Christoph Hellwig869243a2006-01-09 20:52:03 -08001406 struct inode *inode = dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 struct timespec now;
1408
Andrew Mortonb2276132006-12-13 00:34:33 -08001409 if (inode->i_flags & S_NOATIME)
Andi Kleenb12536c2009-09-18 13:05:47 -07001410 return;
Eric Dumazet37756ce2007-02-10 01:44:49 -08001411 if (IS_NOATIME(inode))
Andi Kleenb12536c2009-09-18 13:05:47 -07001412 return;
Andrew Mortonb2276132006-12-13 00:34:33 -08001413 if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))
Andi Kleenb12536c2009-09-18 13:05:47 -07001414 return;
Christoph Hellwigfc33a7b2006-01-09 20:52:17 -08001415
Dave Hansencdb70f32008-02-15 14:37:41 -08001416 if (mnt->mnt_flags & MNT_NOATIME)
Andi Kleenb12536c2009-09-18 13:05:47 -07001417 return;
Dave Hansencdb70f32008-02-15 14:37:41 -08001418 if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
Andi Kleenb12536c2009-09-18 13:05:47 -07001419 return;
Christoph Hellwigfc33a7b2006-01-09 20:52:17 -08001420
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421 now = current_fs_time(inode->i_sb);
Matthew Garrett11ff6f052009-03-26 17:32:14 +00001422
1423 if (!relatime_need_update(mnt, inode, now))
Andi Kleenb12536c2009-09-18 13:05:47 -07001424 return;
Matthew Garrett11ff6f052009-03-26 17:32:14 +00001425
Valerie Henson47ae32d2006-12-13 00:34:34 -08001426 if (timespec_equal(&inode->i_atime, &now))
Andi Kleenb12536c2009-09-18 13:05:47 -07001427 return;
1428
1429 if (mnt_want_write(mnt))
1430 return;
Valerie Henson47ae32d2006-12-13 00:34:34 -08001431
1432 inode->i_atime = now;
1433 mark_inode_dirty_sync(inode);
Dave Hansencdb70f32008-02-15 14:37:41 -08001434 mnt_drop_write(mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435}
Christoph Hellwig869243a2006-01-09 20:52:03 -08001436EXPORT_SYMBOL(touch_atime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001437
1438/**
Christoph Hellwig870f4812006-01-09 20:52:01 -08001439 * file_update_time - update mtime and ctime time
1440 * @file: file accessed
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 *
Christoph Hellwig870f4812006-01-09 20:52:01 -08001442 * Update the mtime and ctime members of an inode and mark the inode
1443 * for writeback. Note that this function is meant exclusively for
1444 * usage in the file write path of filesystems, and filesystems may
1445 * choose to explicitly ignore update via this function with the
Wolfram Sang2eadfc02009-04-02 15:23:37 +02001446 * S_NOCMTIME inode flag, e.g. for network filesystem where these
Christoph Hellwig870f4812006-01-09 20:52:01 -08001447 * timestamps are handled by the server.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448 */
1449
Christoph Hellwig870f4812006-01-09 20:52:01 -08001450void file_update_time(struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451{
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -08001452 struct inode *inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001453 struct timespec now;
Andi Kleence06e0b2009-09-18 13:05:48 -07001454 enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001455
Andi Kleence06e0b2009-09-18 13:05:48 -07001456 /* First try to exhaust all avenues to not sync */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457 if (IS_NOCMTIME(inode))
1458 return;
Dave Hansen20ddee22008-02-15 14:37:43 -08001459
Andi Kleence06e0b2009-09-18 13:05:48 -07001460 now = current_fs_time(inode->i_sb);
1461 if (!timespec_equal(&inode->i_mtime, &now))
1462 sync_it = S_MTIME;
1463
1464 if (!timespec_equal(&inode->i_ctime, &now))
1465 sync_it |= S_CTIME;
1466
1467 if (IS_I_VERSION(inode))
1468 sync_it |= S_VERSION;
1469
1470 if (!sync_it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471 return;
1472
Andi Kleence06e0b2009-09-18 13:05:48 -07001473 /* Finally allowed to write? Takes lock. */
1474 if (mnt_want_write_file(file))
1475 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476
Andi Kleence06e0b2009-09-18 13:05:48 -07001477 /* Only change inode inside the lock region */
1478 if (sync_it & S_VERSION)
Jean Noel Cordenner7a224222008-01-28 23:58:27 -05001479 inode_inc_iversion(inode);
Andi Kleence06e0b2009-09-18 13:05:48 -07001480 if (sync_it & S_CTIME)
1481 inode->i_ctime = now;
1482 if (sync_it & S_MTIME)
1483 inode->i_mtime = now;
1484 mark_inode_dirty_sync(inode);
Dave Hansen20ddee22008-02-15 14:37:43 -08001485 mnt_drop_write(file->f_path.mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486}
Christoph Hellwig870f4812006-01-09 20:52:01 -08001487EXPORT_SYMBOL(file_update_time);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488
1489int inode_needs_sync(struct inode *inode)
1490{
1491 if (IS_SYNC(inode))
1492 return 1;
1493 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
1494 return 1;
1495 return 0;
1496}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001497EXPORT_SYMBOL(inode_needs_sync);
1498
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499int inode_wait(void *word)
1500{
1501 schedule();
1502 return 0;
1503}
Stephen Rothwelld44dab82008-11-10 17:06:05 +11001504EXPORT_SYMBOL(inode_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001505
1506/*
Miklos Szeredi168a9fd2005-07-12 13:58:10 -07001507 * If we try to find an inode in the inode hash while it is being
1508 * deleted, we have to wait until the filesystem completes its
1509 * deletion before reporting that it isn't found. This function waits
1510 * until the deletion _might_ have completed. Callers are responsible
1511 * to recheck inode state.
1512 *
Christoph Hellwigeaff8072009-12-17 14:25:01 +01001513 * It doesn't matter if I_NEW is not set initially, a call to
Miklos Szeredi168a9fd2005-07-12 13:58:10 -07001514 * wake_up_inode() after removing from the hash list will DTRT.
1515 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001516 * This is called with inode_lock held.
1517 */
1518static void __wait_on_freeing_inode(struct inode *inode)
1519{
1520 wait_queue_head_t *wq;
Christoph Hellwigeaff8072009-12-17 14:25:01 +01001521 DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW);
1522 wq = bit_waitqueue(&inode->i_state, __I_NEW);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001523 prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
1524 spin_unlock(&inode_lock);
1525 schedule();
1526 finish_wait(wq, &wait.wait);
1527 spin_lock(&inode_lock);
1528}
1529
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530static __initdata unsigned long ihash_entries;
1531static int __init set_ihash_entries(char *str)
1532{
1533 if (!str)
1534 return 0;
1535 ihash_entries = simple_strtoul(str, &str, 0);
1536 return 1;
1537}
1538__setup("ihash_entries=", set_ihash_entries);
1539
1540/*
1541 * Initialize the waitqueues and inode hash table.
1542 */
1543void __init inode_init_early(void)
1544{
1545 int loop;
1546
1547 /* If hashes are distributed across NUMA nodes, defer
1548 * hash allocation until vmalloc space is available.
1549 */
1550 if (hashdist)
1551 return;
1552
1553 inode_hashtable =
1554 alloc_large_system_hash("Inode-cache",
1555 sizeof(struct hlist_head),
1556 ihash_entries,
1557 14,
1558 HASH_EARLY,
1559 &i_hash_shift,
1560 &i_hash_mask,
1561 0);
1562
1563 for (loop = 0; loop < (1 << i_hash_shift); loop++)
1564 INIT_HLIST_HEAD(&inode_hashtable[loop]);
1565}
1566
Denis Cheng74bf17c2007-10-16 23:26:30 -07001567void __init inode_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001568{
1569 int loop;
1570
1571 /* inode slab cache */
Paul Jacksonb0196002006-03-24 03:16:09 -08001572 inode_cachep = kmem_cache_create("inode_cache",
1573 sizeof(struct inode),
1574 0,
1575 (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
1576 SLAB_MEM_SPREAD),
Paul Mundt20c2df82007-07-20 10:11:58 +09001577 init_once);
Rusty Russell8e1f9362007-07-17 04:03:17 -07001578 register_shrinker(&icache_shrinker);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001579
1580 /* Hash may have been set up in inode_init_early */
1581 if (!hashdist)
1582 return;
1583
1584 inode_hashtable =
1585 alloc_large_system_hash("Inode-cache",
1586 sizeof(struct hlist_head),
1587 ihash_entries,
1588 14,
1589 0,
1590 &i_hash_shift,
1591 &i_hash_mask,
1592 0);
1593
1594 for (loop = 0; loop < (1 << i_hash_shift); loop++)
1595 INIT_HLIST_HEAD(&inode_hashtable[loop]);
1596}
1597
1598void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev)
1599{
1600 inode->i_mode = mode;
1601 if (S_ISCHR(mode)) {
1602 inode->i_fop = &def_chr_fops;
1603 inode->i_rdev = rdev;
1604 } else if (S_ISBLK(mode)) {
1605 inode->i_fop = &def_blk_fops;
1606 inode->i_rdev = rdev;
1607 } else if (S_ISFIFO(mode))
1608 inode->i_fop = &def_fifo_fops;
1609 else if (S_ISSOCK(mode))
1610 inode->i_fop = &bad_sock_fops;
1611 else
Manish Katiyaraf0d9ae2009-09-18 13:05:43 -07001612 printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for"
1613 " inode %s:%lu\n", mode, inode->i_sb->s_id,
1614 inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001615}
1616EXPORT_SYMBOL(init_special_inode);