Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
[cris-mirror.git] / fs / quota / dquot.c
blobfcc8ae75d8743383c8a3436a867bb8c12b1b08b9
1 /*
2 * Implementation of the diskquota system for the LINUX operating system. QUOTA
3 * is implemented using the BSD system call interface as the means of
4 * communication with the user level. This file contains the generic routines
5 * called by the different filesystems on allocation of an inode or block.
6 * These routines take care of the administration needed to have a consistent
7 * diskquota tracking system. The ideas of both user and group quotas are based
8 * on the Melbourne quota system as used on BSD derived systems. The internal
9 * implementation is based on one of the several variants of the LINUX
10 * inode-subsystem with added complexity of the diskquota system.
12 * Author: Marco van Wieringen <mvw@planets.elm.net>
14 * Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
16 * Revised list management to avoid races
17 * -- Bill Hawes, <whawes@star.net>, 9/98
19 * Fixed races in dquot_transfer(), dqget() and dquot_alloc_...().
20 * As the consequence the locking was moved from dquot_decr_...(),
21 * dquot_incr_...() to calling functions.
22 * invalidate_dquots() now writes modified dquots.
23 * Serialized quota_off() and quota_on() for mount point.
24 * Fixed a few bugs in grow_dquots().
25 * Fixed deadlock in write_dquot() - we no longer account quotas on
26 * quota files
27 * remove_dquot_ref() moved to inode.c - it now traverses through inodes
28 * add_dquot_ref() restarts after blocking
29 * Added check for bogus uid and fixed check for group in quotactl.
30 * Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99
32 * Used struct list_head instead of own list struct
33 * Invalidation of referenced dquots is no longer possible
34 * Improved free_dquots list management
35 * Quota and i_blocks are now updated in one place to avoid races
36 * Warnings are now delayed so we won't block in critical section
37 * Write updated not to require dquot lock
38 * Jan Kara, <jack@suse.cz>, 9/2000
40 * Added dynamic quota structure allocation
41 * Jan Kara <jack@suse.cz> 12/2000
43 * Rewritten quota interface. Implemented new quota format and
44 * formats registering.
45 * Jan Kara, <jack@suse.cz>, 2001,2002
47 * New SMP locking.
48 * Jan Kara, <jack@suse.cz>, 10/2002
50 * Added journalled quota support, fix lock inversion problems
51 * Jan Kara, <jack@suse.cz>, 2003,2004
53 * (C) Copyright 1994 - 1997 Marco van Wieringen
56 #include <linux/errno.h>
57 #include <linux/kernel.h>
58 #include <linux/fs.h>
59 #include <linux/mount.h>
60 #include <linux/mm.h>
61 #include <linux/time.h>
62 #include <linux/types.h>
63 #include <linux/string.h>
64 #include <linux/fcntl.h>
65 #include <linux/stat.h>
66 #include <linux/tty.h>
67 #include <linux/file.h>
68 #include <linux/slab.h>
69 #include <linux/sysctl.h>
70 #include <linux/init.h>
71 #include <linux/module.h>
72 #include <linux/proc_fs.h>
73 #include <linux/security.h>
74 #include <linux/kmod.h>
75 #include <linux/namei.h>
76 #include <linux/buffer_head.h>
77 #include <linux/capability.h>
78 #include <linux/quotaops.h>
79 #include "../internal.h" /* ugh */
81 #include <asm/uaccess.h>
84 * There are three quota SMP locks. dq_list_lock protects all lists with quotas
85 * and quota formats.
86 * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
87 * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
88 * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
89 * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
90 * modifications of quota state (on quotaon and quotaoff) and readers who care
91 * about latest values take it as well.
93 * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
94 * dq_list_lock > dq_state_lock
96 * Note that some things (eg. sb pointer, type, id) doesn't change during
97 * the life of the dquot structure and so needn't to be protected by a lock
99 * Any operation working on dquots via inode pointers must hold dqptr_sem. If
100 * operation is just reading pointers from inode (or not using them at all) the
101 * read lock is enough. If pointers are altered function must hold write lock.
102 * Special care needs to be taken about S_NOQUOTA inode flag (marking that
103 * inode is a quota file). Functions adding pointers from inode to dquots have
104 * to check this flag under dqptr_sem and then (if S_NOQUOTA is not set) they
105 * have to do all pointer modifications before dropping dqptr_sem. This makes
106 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and
107 * then drops all pointers to dquots from an inode.
109 * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
110 * from inodes (dquot_alloc_space() and such don't check the dq_lock).
111 * Currently dquot is locked only when it is being read to memory (or space for
112 * it is being allocated) on the first dqget() and when it is being released on
113 * the last dqput(). The allocation and release oparations are serialized by
114 * the dq_lock and by checking the use count in dquot_release(). Write
115 * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
116 * spinlock to internal buffers before writing.
118 * Lock ordering (including related VFS locks) is the following:
119 * i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
120 * dqio_mutex
121 * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem >
122 * dqptr_sem. But filesystem has to count with the fact that functions such as
123 * dquot_alloc_space() acquire dqptr_sem and they usually have to be called
124 * from inside a transaction to keep filesystem consistency after a crash. Also
125 * filesystems usually want to do some IO on dquot from ->mark_dirty which is
126 * called with dqptr_sem held.
127 * i_mutex on quota files is special (it's below dqio_mutex)
130 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
131 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
132 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
133 EXPORT_SYMBOL(dq_data_lock);
135 void __quota_error(struct super_block *sb, const char *func,
136 const char *fmt, ...)
138 if (printk_ratelimit()) {
139 va_list args;
140 struct va_format vaf;
142 va_start(args, fmt);
144 vaf.fmt = fmt;
145 vaf.va = &args;
147 printk(KERN_ERR "Quota error (device %s): %s: %pV\n",
148 sb->s_id, func, &vaf);
150 va_end(args);
153 EXPORT_SYMBOL(__quota_error);
155 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING)
156 static char *quotatypes[] = INITQFNAMES;
157 #endif
158 static struct quota_format_type *quota_formats; /* List of registered formats */
159 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
161 /* SLAB cache for dquot structures */
162 static struct kmem_cache *dquot_cachep;
164 int register_quota_format(struct quota_format_type *fmt)
166 spin_lock(&dq_list_lock);
167 fmt->qf_next = quota_formats;
168 quota_formats = fmt;
169 spin_unlock(&dq_list_lock);
170 return 0;
172 EXPORT_SYMBOL(register_quota_format);
174 void unregister_quota_format(struct quota_format_type *fmt)
176 struct quota_format_type **actqf;
178 spin_lock(&dq_list_lock);
179 for (actqf = &quota_formats; *actqf && *actqf != fmt;
180 actqf = &(*actqf)->qf_next)
182 if (*actqf)
183 *actqf = (*actqf)->qf_next;
184 spin_unlock(&dq_list_lock);
186 EXPORT_SYMBOL(unregister_quota_format);
188 static struct quota_format_type *find_quota_format(int id)
190 struct quota_format_type *actqf;
192 spin_lock(&dq_list_lock);
193 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
194 actqf = actqf->qf_next)
196 if (!actqf || !try_module_get(actqf->qf_owner)) {
197 int qm;
199 spin_unlock(&dq_list_lock);
201 for (qm = 0; module_names[qm].qm_fmt_id &&
202 module_names[qm].qm_fmt_id != id; qm++)
204 if (!module_names[qm].qm_fmt_id ||
205 request_module(module_names[qm].qm_mod_name))
206 return NULL;
208 spin_lock(&dq_list_lock);
209 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
210 actqf = actqf->qf_next)
212 if (actqf && !try_module_get(actqf->qf_owner))
213 actqf = NULL;
215 spin_unlock(&dq_list_lock);
216 return actqf;
219 static void put_quota_format(struct quota_format_type *fmt)
221 module_put(fmt->qf_owner);
225 * Dquot List Management:
226 * The quota code uses three lists for dquot management: the inuse_list,
227 * free_dquots, and dquot_hash[] array. A single dquot structure may be
228 * on all three lists, depending on its current state.
230 * All dquots are placed to the end of inuse_list when first created, and this
231 * list is used for invalidate operation, which must look at every dquot.
233 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
234 * and this list is searched whenever we need an available dquot. Dquots are
235 * removed from the list as soon as they are used again, and
236 * dqstats.free_dquots gives the number of dquots on the list. When
237 * dquot is invalidated it's completely released from memory.
239 * Dquots with a specific identity (device, type and id) are placed on
240 * one of the dquot_hash[] hash chains. The provides an efficient search
241 * mechanism to locate a specific dquot.
244 static LIST_HEAD(inuse_list);
245 static LIST_HEAD(free_dquots);
246 static unsigned int dq_hash_bits, dq_hash_mask;
247 static struct hlist_head *dquot_hash;
249 struct dqstats dqstats;
250 EXPORT_SYMBOL(dqstats);
252 static qsize_t inode_get_rsv_space(struct inode *inode);
253 static void __dquot_initialize(struct inode *inode, int type);
255 static inline unsigned int
256 hashfn(const struct super_block *sb, unsigned int id, int type)
258 unsigned long tmp;
260 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
261 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
265 * Following list functions expect dq_list_lock to be held
267 static inline void insert_dquot_hash(struct dquot *dquot)
269 struct hlist_head *head;
270 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
271 hlist_add_head(&dquot->dq_hash, head);
274 static inline void remove_dquot_hash(struct dquot *dquot)
276 hlist_del_init(&dquot->dq_hash);
279 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
280 unsigned int id, int type)
282 struct hlist_node *node;
283 struct dquot *dquot;
285 hlist_for_each (node, dquot_hash+hashent) {
286 dquot = hlist_entry(node, struct dquot, dq_hash);
287 if (dquot->dq_sb == sb && dquot->dq_id == id &&
288 dquot->dq_type == type)
289 return dquot;
291 return NULL;
294 /* Add a dquot to the tail of the free list */
295 static inline void put_dquot_last(struct dquot *dquot)
297 list_add_tail(&dquot->dq_free, &free_dquots);
298 dqstats_inc(DQST_FREE_DQUOTS);
301 static inline void remove_free_dquot(struct dquot *dquot)
303 if (list_empty(&dquot->dq_free))
304 return;
305 list_del_init(&dquot->dq_free);
306 dqstats_dec(DQST_FREE_DQUOTS);
309 static inline void put_inuse(struct dquot *dquot)
311 /* We add to the back of inuse list so we don't have to restart
312 * when traversing this list and we block */
313 list_add_tail(&dquot->dq_inuse, &inuse_list);
314 dqstats_inc(DQST_ALLOC_DQUOTS);
317 static inline void remove_inuse(struct dquot *dquot)
319 dqstats_dec(DQST_ALLOC_DQUOTS);
320 list_del(&dquot->dq_inuse);
323 * End of list functions needing dq_list_lock
326 static void wait_on_dquot(struct dquot *dquot)
328 mutex_lock(&dquot->dq_lock);
329 mutex_unlock(&dquot->dq_lock);
332 static inline int dquot_dirty(struct dquot *dquot)
334 return test_bit(DQ_MOD_B, &dquot->dq_flags);
337 static inline int mark_dquot_dirty(struct dquot *dquot)
339 return dquot->dq_sb->dq_op->mark_dirty(dquot);
342 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */
343 int dquot_mark_dquot_dirty(struct dquot *dquot)
345 int ret = 1;
347 /* If quota is dirty already, we don't have to acquire dq_list_lock */
348 if (test_bit(DQ_MOD_B, &dquot->dq_flags))
349 return 1;
351 spin_lock(&dq_list_lock);
352 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) {
353 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
354 info[dquot->dq_type].dqi_dirty_list);
355 ret = 0;
357 spin_unlock(&dq_list_lock);
358 return ret;
360 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
362 /* Dirtify all the dquots - this can block when journalling */
363 static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
365 int ret, err, cnt;
367 ret = err = 0;
368 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
369 if (dquot[cnt])
370 /* Even in case of error we have to continue */
371 ret = mark_dquot_dirty(dquot[cnt]);
372 if (!err)
373 err = ret;
375 return err;
378 static inline void dqput_all(struct dquot **dquot)
380 unsigned int cnt;
382 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
383 dqput(dquot[cnt]);
386 /* This function needs dq_list_lock */
387 static inline int clear_dquot_dirty(struct dquot *dquot)
389 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
390 return 0;
391 list_del_init(&dquot->dq_dirty);
392 return 1;
395 void mark_info_dirty(struct super_block *sb, int type)
397 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
399 EXPORT_SYMBOL(mark_info_dirty);
402 * Read dquot from disk and alloc space for it
405 int dquot_acquire(struct dquot *dquot)
407 int ret = 0, ret2 = 0;
408 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
410 mutex_lock(&dquot->dq_lock);
411 mutex_lock(&dqopt->dqio_mutex);
412 if (!test_bit(DQ_READ_B, &dquot->dq_flags))
413 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
414 if (ret < 0)
415 goto out_iolock;
416 set_bit(DQ_READ_B, &dquot->dq_flags);
417 /* Instantiate dquot if needed */
418 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
419 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
420 /* Write the info if needed */
421 if (info_dirty(&dqopt->info[dquot->dq_type])) {
422 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
423 dquot->dq_sb, dquot->dq_type);
425 if (ret < 0)
426 goto out_iolock;
427 if (ret2 < 0) {
428 ret = ret2;
429 goto out_iolock;
432 set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
433 out_iolock:
434 mutex_unlock(&dqopt->dqio_mutex);
435 mutex_unlock(&dquot->dq_lock);
436 return ret;
438 EXPORT_SYMBOL(dquot_acquire);
441 * Write dquot to disk
443 int dquot_commit(struct dquot *dquot)
445 int ret = 0, ret2 = 0;
446 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
448 mutex_lock(&dqopt->dqio_mutex);
449 spin_lock(&dq_list_lock);
450 if (!clear_dquot_dirty(dquot)) {
451 spin_unlock(&dq_list_lock);
452 goto out_sem;
454 spin_unlock(&dq_list_lock);
455 /* Inactive dquot can be only if there was error during read/init
456 * => we have better not writing it */
457 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
458 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
459 if (info_dirty(&dqopt->info[dquot->dq_type])) {
460 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
461 dquot->dq_sb, dquot->dq_type);
463 if (ret >= 0)
464 ret = ret2;
466 out_sem:
467 mutex_unlock(&dqopt->dqio_mutex);
468 return ret;
470 EXPORT_SYMBOL(dquot_commit);
473 * Release dquot
475 int dquot_release(struct dquot *dquot)
477 int ret = 0, ret2 = 0;
478 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
480 mutex_lock(&dquot->dq_lock);
481 /* Check whether we are not racing with some other dqget() */
482 if (atomic_read(&dquot->dq_count) > 1)
483 goto out_dqlock;
484 mutex_lock(&dqopt->dqio_mutex);
485 if (dqopt->ops[dquot->dq_type]->release_dqblk) {
486 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
487 /* Write the info */
488 if (info_dirty(&dqopt->info[dquot->dq_type])) {
489 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
490 dquot->dq_sb, dquot->dq_type);
492 if (ret >= 0)
493 ret = ret2;
495 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
496 mutex_unlock(&dqopt->dqio_mutex);
497 out_dqlock:
498 mutex_unlock(&dquot->dq_lock);
499 return ret;
501 EXPORT_SYMBOL(dquot_release);
503 void dquot_destroy(struct dquot *dquot)
505 kmem_cache_free(dquot_cachep, dquot);
507 EXPORT_SYMBOL(dquot_destroy);
509 static inline void do_destroy_dquot(struct dquot *dquot)
511 dquot->dq_sb->dq_op->destroy_dquot(dquot);
514 /* Invalidate all dquots on the list. Note that this function is called after
515 * quota is disabled and pointers from inodes removed so there cannot be new
516 * quota users. There can still be some users of quotas due to inodes being
517 * just deleted or pruned by prune_icache() (those are not attached to any
518 * list) or parallel quotactl call. We have to wait for such users.
520 static void invalidate_dquots(struct super_block *sb, int type)
522 struct dquot *dquot, *tmp;
524 restart:
525 spin_lock(&dq_list_lock);
526 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
527 if (dquot->dq_sb != sb)
528 continue;
529 if (dquot->dq_type != type)
530 continue;
531 /* Wait for dquot users */
532 if (atomic_read(&dquot->dq_count)) {
533 DEFINE_WAIT(wait);
535 atomic_inc(&dquot->dq_count);
536 prepare_to_wait(&dquot->dq_wait_unused, &wait,
537 TASK_UNINTERRUPTIBLE);
538 spin_unlock(&dq_list_lock);
539 /* Once dqput() wakes us up, we know it's time to free
540 * the dquot.
541 * IMPORTANT: we rely on the fact that there is always
542 * at most one process waiting for dquot to free.
543 * Otherwise dq_count would be > 1 and we would never
544 * wake up.
546 if (atomic_read(&dquot->dq_count) > 1)
547 schedule();
548 finish_wait(&dquot->dq_wait_unused, &wait);
549 dqput(dquot);
550 /* At this moment dquot() need not exist (it could be
551 * reclaimed by prune_dqcache(). Hence we must
552 * restart. */
553 goto restart;
556 * Quota now has no users and it has been written on last
557 * dqput()
559 remove_dquot_hash(dquot);
560 remove_free_dquot(dquot);
561 remove_inuse(dquot);
562 do_destroy_dquot(dquot);
564 spin_unlock(&dq_list_lock);
567 /* Call callback for every active dquot on given filesystem */
568 int dquot_scan_active(struct super_block *sb,
569 int (*fn)(struct dquot *dquot, unsigned long priv),
570 unsigned long priv)
572 struct dquot *dquot, *old_dquot = NULL;
573 int ret = 0;
575 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
576 spin_lock(&dq_list_lock);
577 list_for_each_entry(dquot, &inuse_list, dq_inuse) {
578 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
579 continue;
580 if (dquot->dq_sb != sb)
581 continue;
582 /* Now we have active dquot so we can just increase use count */
583 atomic_inc(&dquot->dq_count);
584 spin_unlock(&dq_list_lock);
585 dqstats_inc(DQST_LOOKUPS);
586 dqput(old_dquot);
587 old_dquot = dquot;
588 ret = fn(dquot, priv);
589 if (ret < 0)
590 goto out;
591 spin_lock(&dq_list_lock);
592 /* We are safe to continue now because our dquot could not
593 * be moved out of the inuse list while we hold the reference */
595 spin_unlock(&dq_list_lock);
596 out:
597 dqput(old_dquot);
598 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
599 return ret;
601 EXPORT_SYMBOL(dquot_scan_active);
603 int dquot_quota_sync(struct super_block *sb, int type, int wait)
605 struct list_head *dirty;
606 struct dquot *dquot;
607 struct quota_info *dqopt = sb_dqopt(sb);
608 int cnt;
610 mutex_lock(&dqopt->dqonoff_mutex);
611 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
612 if (type != -1 && cnt != type)
613 continue;
614 if (!sb_has_quota_active(sb, cnt))
615 continue;
616 spin_lock(&dq_list_lock);
617 dirty = &dqopt->info[cnt].dqi_dirty_list;
618 while (!list_empty(dirty)) {
619 dquot = list_first_entry(dirty, struct dquot,
620 dq_dirty);
621 /* Dirty and inactive can be only bad dquot... */
622 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
623 clear_dquot_dirty(dquot);
624 continue;
626 /* Now we have active dquot from which someone is
627 * holding reference so we can safely just increase
628 * use count */
629 atomic_inc(&dquot->dq_count);
630 spin_unlock(&dq_list_lock);
631 dqstats_inc(DQST_LOOKUPS);
632 sb->dq_op->write_dquot(dquot);
633 dqput(dquot);
634 spin_lock(&dq_list_lock);
636 spin_unlock(&dq_list_lock);
639 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
640 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
641 && info_dirty(&dqopt->info[cnt]))
642 sb->dq_op->write_info(sb, cnt);
643 dqstats_inc(DQST_SYNCS);
644 mutex_unlock(&dqopt->dqonoff_mutex);
646 if (!wait || (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE))
647 return 0;
649 /* This is not very clever (and fast) but currently I don't know about
650 * any other simple way of getting quota data to disk and we must get
651 * them there for userspace to be visible... */
652 if (sb->s_op->sync_fs)
653 sb->s_op->sync_fs(sb, 1);
654 sync_blockdev(sb->s_bdev);
657 * Now when everything is written we can discard the pagecache so
658 * that userspace sees the changes.
660 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
661 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
662 if (type != -1 && cnt != type)
663 continue;
664 if (!sb_has_quota_active(sb, cnt))
665 continue;
666 mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex,
667 I_MUTEX_QUOTA);
668 truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
669 mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
671 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
673 return 0;
675 EXPORT_SYMBOL(dquot_quota_sync);
677 /* Free unused dquots from cache */
678 static void prune_dqcache(int count)
680 struct list_head *head;
681 struct dquot *dquot;
683 head = free_dquots.prev;
684 while (head != &free_dquots && count) {
685 dquot = list_entry(head, struct dquot, dq_free);
686 remove_dquot_hash(dquot);
687 remove_free_dquot(dquot);
688 remove_inuse(dquot);
689 do_destroy_dquot(dquot);
690 count--;
691 head = free_dquots.prev;
696 * This is called from kswapd when we think we need some
697 * more memory
699 static int shrink_dqcache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask)
701 if (nr) {
702 spin_lock(&dq_list_lock);
703 prune_dqcache(nr);
704 spin_unlock(&dq_list_lock);
706 return ((unsigned)
707 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])
708 /100) * sysctl_vfs_cache_pressure;
711 static struct shrinker dqcache_shrinker = {
712 .shrink = shrink_dqcache_memory,
713 .seeks = DEFAULT_SEEKS,
717 * Put reference to dquot
718 * NOTE: If you change this function please check whether dqput_blocks() works right...
720 void dqput(struct dquot *dquot)
722 int ret;
724 if (!dquot)
725 return;
726 #ifdef CONFIG_QUOTA_DEBUG
727 if (!atomic_read(&dquot->dq_count)) {
728 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d",
729 quotatypes[dquot->dq_type], dquot->dq_id);
730 BUG();
732 #endif
733 dqstats_inc(DQST_DROPS);
734 we_slept:
735 spin_lock(&dq_list_lock);
736 if (atomic_read(&dquot->dq_count) > 1) {
737 /* We have more than one user... nothing to do */
738 atomic_dec(&dquot->dq_count);
739 /* Releasing dquot during quotaoff phase? */
740 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
741 atomic_read(&dquot->dq_count) == 1)
742 wake_up(&dquot->dq_wait_unused);
743 spin_unlock(&dq_list_lock);
744 return;
746 /* Need to release dquot? */
747 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
748 spin_unlock(&dq_list_lock);
749 /* Commit dquot before releasing */
750 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
751 if (ret < 0) {
752 quota_error(dquot->dq_sb, "Can't write quota structure"
753 " (error %d). Quota may get out of sync!",
754 ret);
756 * We clear dirty bit anyway, so that we avoid
757 * infinite loop here
759 spin_lock(&dq_list_lock);
760 clear_dquot_dirty(dquot);
761 spin_unlock(&dq_list_lock);
763 goto we_slept;
765 /* Clear flag in case dquot was inactive (something bad happened) */
766 clear_dquot_dirty(dquot);
767 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
768 spin_unlock(&dq_list_lock);
769 dquot->dq_sb->dq_op->release_dquot(dquot);
770 goto we_slept;
772 atomic_dec(&dquot->dq_count);
773 #ifdef CONFIG_QUOTA_DEBUG
774 /* sanity check */
775 BUG_ON(!list_empty(&dquot->dq_free));
776 #endif
777 put_dquot_last(dquot);
778 spin_unlock(&dq_list_lock);
780 EXPORT_SYMBOL(dqput);
782 struct dquot *dquot_alloc(struct super_block *sb, int type)
784 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
786 EXPORT_SYMBOL(dquot_alloc);
788 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
790 struct dquot *dquot;
792 dquot = sb->dq_op->alloc_dquot(sb, type);
793 if(!dquot)
794 return NULL;
796 mutex_init(&dquot->dq_lock);
797 INIT_LIST_HEAD(&dquot->dq_free);
798 INIT_LIST_HEAD(&dquot->dq_inuse);
799 INIT_HLIST_NODE(&dquot->dq_hash);
800 INIT_LIST_HEAD(&dquot->dq_dirty);
801 init_waitqueue_head(&dquot->dq_wait_unused);
802 dquot->dq_sb = sb;
803 dquot->dq_type = type;
804 atomic_set(&dquot->dq_count, 1);
806 return dquot;
810 * Get reference to dquot
812 * Locking is slightly tricky here. We are guarded from parallel quotaoff()
813 * destroying our dquot by:
814 * a) checking for quota flags under dq_list_lock and
815 * b) getting a reference to dquot before we release dq_list_lock
817 struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
819 unsigned int hashent = hashfn(sb, id, type);
820 struct dquot *dquot = NULL, *empty = NULL;
822 if (!sb_has_quota_active(sb, type))
823 return NULL;
824 we_slept:
825 spin_lock(&dq_list_lock);
826 spin_lock(&dq_state_lock);
827 if (!sb_has_quota_active(sb, type)) {
828 spin_unlock(&dq_state_lock);
829 spin_unlock(&dq_list_lock);
830 goto out;
832 spin_unlock(&dq_state_lock);
834 dquot = find_dquot(hashent, sb, id, type);
835 if (!dquot) {
836 if (!empty) {
837 spin_unlock(&dq_list_lock);
838 empty = get_empty_dquot(sb, type);
839 if (!empty)
840 schedule(); /* Try to wait for a moment... */
841 goto we_slept;
843 dquot = empty;
844 empty = NULL;
845 dquot->dq_id = id;
846 /* all dquots go on the inuse_list */
847 put_inuse(dquot);
848 /* hash it first so it can be found */
849 insert_dquot_hash(dquot);
850 spin_unlock(&dq_list_lock);
851 dqstats_inc(DQST_LOOKUPS);
852 } else {
853 if (!atomic_read(&dquot->dq_count))
854 remove_free_dquot(dquot);
855 atomic_inc(&dquot->dq_count);
856 spin_unlock(&dq_list_lock);
857 dqstats_inc(DQST_CACHE_HITS);
858 dqstats_inc(DQST_LOOKUPS);
860 /* Wait for dq_lock - after this we know that either dquot_release() is
861 * already finished or it will be canceled due to dq_count > 1 test */
862 wait_on_dquot(dquot);
863 /* Read the dquot / allocate space in quota file */
864 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) &&
865 sb->dq_op->acquire_dquot(dquot) < 0) {
866 dqput(dquot);
867 dquot = NULL;
868 goto out;
870 #ifdef CONFIG_QUOTA_DEBUG
871 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */
872 #endif
873 out:
874 if (empty)
875 do_destroy_dquot(empty);
877 return dquot;
879 EXPORT_SYMBOL(dqget);
881 static int dqinit_needed(struct inode *inode, int type)
883 int cnt;
885 if (IS_NOQUOTA(inode))
886 return 0;
887 if (type != -1)
888 return !inode->i_dquot[type];
889 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
890 if (!inode->i_dquot[cnt])
891 return 1;
892 return 0;
895 /* This routine is guarded by dqonoff_mutex mutex */
896 static void add_dquot_ref(struct super_block *sb, int type)
898 struct inode *inode, *old_inode = NULL;
899 #ifdef CONFIG_QUOTA_DEBUG
900 int reserved = 0;
901 #endif
903 spin_lock(&inode_sb_list_lock);
904 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
905 spin_lock(&inode->i_lock);
906 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
907 !atomic_read(&inode->i_writecount) ||
908 !dqinit_needed(inode, type)) {
909 spin_unlock(&inode->i_lock);
910 continue;
912 #ifdef CONFIG_QUOTA_DEBUG
913 if (unlikely(inode_get_rsv_space(inode) > 0))
914 reserved = 1;
915 #endif
916 __iget(inode);
917 spin_unlock(&inode->i_lock);
918 spin_unlock(&inode_sb_list_lock);
920 iput(old_inode);
921 __dquot_initialize(inode, type);
924 * We hold a reference to 'inode' so it couldn't have been
925 * removed from s_inodes list while we dropped the
926 * inode_sb_list_lock We cannot iput the inode now as we can be
927 * holding the last reference and we cannot iput it under
928 * inode_sb_list_lock. So we keep the reference and iput it
929 * later.
931 old_inode = inode;
932 spin_lock(&inode_sb_list_lock);
934 spin_unlock(&inode_sb_list_lock);
935 iput(old_inode);
937 #ifdef CONFIG_QUOTA_DEBUG
938 if (reserved) {
939 quota_error(sb, "Writes happened before quota was turned on "
940 "thus quota information is probably inconsistent. "
941 "Please run quotacheck(8)");
943 #endif
947 * Return 0 if dqput() won't block.
948 * (note that 1 doesn't necessarily mean blocking)
950 static inline int dqput_blocks(struct dquot *dquot)
952 if (atomic_read(&dquot->dq_count) <= 1)
953 return 1;
954 return 0;
958 * Remove references to dquots from inode and add dquot to list for freeing
959 * if we have the last referece to dquot
960 * We can't race with anybody because we hold dqptr_sem for writing...
962 static int remove_inode_dquot_ref(struct inode *inode, int type,
963 struct list_head *tofree_head)
965 struct dquot *dquot = inode->i_dquot[type];
967 inode->i_dquot[type] = NULL;
968 if (dquot) {
969 if (dqput_blocks(dquot)) {
970 #ifdef CONFIG_QUOTA_DEBUG
971 if (atomic_read(&dquot->dq_count) != 1)
972 quota_error(inode->i_sb, "Adding dquot with "
973 "dq_count %d to dispose list",
974 atomic_read(&dquot->dq_count));
975 #endif
976 spin_lock(&dq_list_lock);
977 /* As dquot must have currently users it can't be on
978 * the free list... */
979 list_add(&dquot->dq_free, tofree_head);
980 spin_unlock(&dq_list_lock);
981 return 1;
983 else
984 dqput(dquot); /* We have guaranteed we won't block */
986 return 0;
990 * Free list of dquots
991 * Dquots are removed from inodes and no new references can be got so we are
992 * the only ones holding reference
994 static void put_dquot_list(struct list_head *tofree_head)
996 struct list_head *act_head;
997 struct dquot *dquot;
999 act_head = tofree_head->next;
1000 while (act_head != tofree_head) {
1001 dquot = list_entry(act_head, struct dquot, dq_free);
1002 act_head = act_head->next;
1003 /* Remove dquot from the list so we won't have problems... */
1004 list_del_init(&dquot->dq_free);
1005 dqput(dquot);
1009 static void remove_dquot_ref(struct super_block *sb, int type,
1010 struct list_head *tofree_head)
1012 struct inode *inode;
1013 int reserved = 0;
1015 spin_lock(&inode_sb_list_lock);
1016 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
1018 * We have to scan also I_NEW inodes because they can already
1019 * have quota pointer initialized. Luckily, we need to touch
1020 * only quota pointers and these have separate locking
1021 * (dqptr_sem).
1023 if (!IS_NOQUOTA(inode)) {
1024 if (unlikely(inode_get_rsv_space(inode) > 0))
1025 reserved = 1;
1026 remove_inode_dquot_ref(inode, type, tofree_head);
1029 spin_unlock(&inode_sb_list_lock);
1030 #ifdef CONFIG_QUOTA_DEBUG
1031 if (reserved) {
1032 printk(KERN_WARNING "VFS (%s): Writes happened after quota"
1033 " was disabled thus quota information is probably "
1034 "inconsistent. Please run quotacheck(8).\n", sb->s_id);
1036 #endif
1039 /* Gather all references from inodes and drop them */
1040 static void drop_dquot_ref(struct super_block *sb, int type)
1042 LIST_HEAD(tofree_head);
1044 if (sb->dq_op) {
1045 down_write(&sb_dqopt(sb)->dqptr_sem);
1046 remove_dquot_ref(sb, type, &tofree_head);
1047 up_write(&sb_dqopt(sb)->dqptr_sem);
1048 put_dquot_list(&tofree_head);
1052 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
1054 dquot->dq_dqb.dqb_curinodes += number;
1057 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
1059 dquot->dq_dqb.dqb_curspace += number;
1062 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
1064 dquot->dq_dqb.dqb_rsvspace += number;
1068 * Claim reserved quota space
1070 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number)
1072 if (dquot->dq_dqb.dqb_rsvspace < number) {
1073 WARN_ON_ONCE(1);
1074 number = dquot->dq_dqb.dqb_rsvspace;
1076 dquot->dq_dqb.dqb_curspace += number;
1077 dquot->dq_dqb.dqb_rsvspace -= number;
1080 static inline
1081 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
1083 if (dquot->dq_dqb.dqb_rsvspace >= number)
1084 dquot->dq_dqb.dqb_rsvspace -= number;
1085 else {
1086 WARN_ON_ONCE(1);
1087 dquot->dq_dqb.dqb_rsvspace = 0;
1091 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1093 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1094 dquot->dq_dqb.dqb_curinodes >= number)
1095 dquot->dq_dqb.dqb_curinodes -= number;
1096 else
1097 dquot->dq_dqb.dqb_curinodes = 0;
1098 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1099 dquot->dq_dqb.dqb_itime = (time_t) 0;
1100 clear_bit(DQ_INODES_B, &dquot->dq_flags);
1103 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1105 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1106 dquot->dq_dqb.dqb_curspace >= number)
1107 dquot->dq_dqb.dqb_curspace -= number;
1108 else
1109 dquot->dq_dqb.dqb_curspace = 0;
1110 if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1111 dquot->dq_dqb.dqb_btime = (time_t) 0;
1112 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1115 static int warning_issued(struct dquot *dquot, const int warntype)
1117 int flag = (warntype == QUOTA_NL_BHARDWARN ||
1118 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1119 ((warntype == QUOTA_NL_IHARDWARN ||
1120 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1122 if (!flag)
1123 return 0;
1124 return test_and_set_bit(flag, &dquot->dq_flags);
1127 #ifdef CONFIG_PRINT_QUOTA_WARNING
1128 static int flag_print_warnings = 1;
1130 static int need_print_warning(struct dquot *dquot)
1132 if (!flag_print_warnings)
1133 return 0;
1135 switch (dquot->dq_type) {
1136 case USRQUOTA:
1137 return current_fsuid() == dquot->dq_id;
1138 case GRPQUOTA:
1139 return in_group_p(dquot->dq_id);
1141 return 0;
1144 /* Print warning to user which exceeded quota */
1145 static void print_warning(struct dquot *dquot, const int warntype)
1147 char *msg = NULL;
1148 struct tty_struct *tty;
1150 if (warntype == QUOTA_NL_IHARDBELOW ||
1151 warntype == QUOTA_NL_ISOFTBELOW ||
1152 warntype == QUOTA_NL_BHARDBELOW ||
1153 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
1154 return;
1156 tty = get_current_tty();
1157 if (!tty)
1158 return;
1159 tty_write_message(tty, dquot->dq_sb->s_id);
1160 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1161 tty_write_message(tty, ": warning, ");
1162 else
1163 tty_write_message(tty, ": write failed, ");
1164 tty_write_message(tty, quotatypes[dquot->dq_type]);
1165 switch (warntype) {
1166 case QUOTA_NL_IHARDWARN:
1167 msg = " file limit reached.\r\n";
1168 break;
1169 case QUOTA_NL_ISOFTLONGWARN:
1170 msg = " file quota exceeded too long.\r\n";
1171 break;
1172 case QUOTA_NL_ISOFTWARN:
1173 msg = " file quota exceeded.\r\n";
1174 break;
1175 case QUOTA_NL_BHARDWARN:
1176 msg = " block limit reached.\r\n";
1177 break;
1178 case QUOTA_NL_BSOFTLONGWARN:
1179 msg = " block quota exceeded too long.\r\n";
1180 break;
1181 case QUOTA_NL_BSOFTWARN:
1182 msg = " block quota exceeded.\r\n";
1183 break;
1185 tty_write_message(tty, msg);
1186 tty_kref_put(tty);
1188 #endif
1191 * Write warnings to the console and send warning messages over netlink.
1193 * Note that this function can sleep.
1195 static void flush_warnings(struct dquot *const *dquots, char *warntype)
1197 struct dquot *dq;
1198 int i;
1200 for (i = 0; i < MAXQUOTAS; i++) {
1201 dq = dquots[i];
1202 if (dq && warntype[i] != QUOTA_NL_NOWARN &&
1203 !warning_issued(dq, warntype[i])) {
1204 #ifdef CONFIG_PRINT_QUOTA_WARNING
1205 print_warning(dq, warntype[i]);
1206 #endif
1207 quota_send_warning(dq->dq_type, dq->dq_id,
1208 dq->dq_sb->s_dev, warntype[i]);
1213 static int ignore_hardlimit(struct dquot *dquot)
1215 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1217 return capable(CAP_SYS_RESOURCE) &&
1218 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1219 !(info->dqi_flags & V1_DQF_RSQUASH));
1222 /* needs dq_data_lock */
1223 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
1225 qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1227 *warntype = QUOTA_NL_NOWARN;
1228 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1229 test_bit(DQ_FAKE_B, &dquot->dq_flags))
1230 return 0;
1232 if (dquot->dq_dqb.dqb_ihardlimit &&
1233 newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1234 !ignore_hardlimit(dquot)) {
1235 *warntype = QUOTA_NL_IHARDWARN;
1236 return -EDQUOT;
1239 if (dquot->dq_dqb.dqb_isoftlimit &&
1240 newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1241 dquot->dq_dqb.dqb_itime &&
1242 get_seconds() >= dquot->dq_dqb.dqb_itime &&
1243 !ignore_hardlimit(dquot)) {
1244 *warntype = QUOTA_NL_ISOFTLONGWARN;
1245 return -EDQUOT;
1248 if (dquot->dq_dqb.dqb_isoftlimit &&
1249 newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1250 dquot->dq_dqb.dqb_itime == 0) {
1251 *warntype = QUOTA_NL_ISOFTWARN;
1252 dquot->dq_dqb.dqb_itime = get_seconds() +
1253 sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1256 return 0;
1259 /* needs dq_data_lock */
1260 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1262 qsize_t tspace;
1263 struct super_block *sb = dquot->dq_sb;
1265 *warntype = QUOTA_NL_NOWARN;
1266 if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
1267 test_bit(DQ_FAKE_B, &dquot->dq_flags))
1268 return 0;
1270 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1271 + space;
1273 if (dquot->dq_dqb.dqb_bhardlimit &&
1274 tspace > dquot->dq_dqb.dqb_bhardlimit &&
1275 !ignore_hardlimit(dquot)) {
1276 if (!prealloc)
1277 *warntype = QUOTA_NL_BHARDWARN;
1278 return -EDQUOT;
1281 if (dquot->dq_dqb.dqb_bsoftlimit &&
1282 tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1283 dquot->dq_dqb.dqb_btime &&
1284 get_seconds() >= dquot->dq_dqb.dqb_btime &&
1285 !ignore_hardlimit(dquot)) {
1286 if (!prealloc)
1287 *warntype = QUOTA_NL_BSOFTLONGWARN;
1288 return -EDQUOT;
1291 if (dquot->dq_dqb.dqb_bsoftlimit &&
1292 tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1293 dquot->dq_dqb.dqb_btime == 0) {
1294 if (!prealloc) {
1295 *warntype = QUOTA_NL_BSOFTWARN;
1296 dquot->dq_dqb.dqb_btime = get_seconds() +
1297 sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
1299 else
1301 * We don't allow preallocation to exceed softlimit so exceeding will
1302 * be always printed
1304 return -EDQUOT;
1307 return 0;
1310 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1312 qsize_t newinodes;
1314 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1315 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1316 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
1317 return QUOTA_NL_NOWARN;
1319 newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1320 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1321 return QUOTA_NL_ISOFTBELOW;
1322 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1323 newinodes < dquot->dq_dqb.dqb_ihardlimit)
1324 return QUOTA_NL_IHARDBELOW;
1325 return QUOTA_NL_NOWARN;
1328 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1330 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1331 dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1332 return QUOTA_NL_NOWARN;
1334 if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1335 return QUOTA_NL_BSOFTBELOW;
1336 if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1337 dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1338 return QUOTA_NL_BHARDBELOW;
1339 return QUOTA_NL_NOWARN;
1342 static int dquot_active(const struct inode *inode)
1344 struct super_block *sb = inode->i_sb;
1346 if (IS_NOQUOTA(inode))
1347 return 0;
1348 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
1352 * Initialize quota pointers in inode
1354 * We do things in a bit complicated way but by that we avoid calling
1355 * dqget() and thus filesystem callbacks under dqptr_sem.
1357 * It is better to call this function outside of any transaction as it
1358 * might need a lot of space in journal for dquot structure allocation.
1360 static void __dquot_initialize(struct inode *inode, int type)
1362 unsigned int id = 0;
1363 int cnt;
1364 struct dquot *got[MAXQUOTAS];
1365 struct super_block *sb = inode->i_sb;
1366 qsize_t rsv;
1368 /* First test before acquiring mutex - solves deadlocks when we
1369 * re-enter the quota code and are already holding the mutex */
1370 if (!dquot_active(inode))
1371 return;
1373 /* First get references to structures we might need. */
1374 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1375 got[cnt] = NULL;
1376 if (type != -1 && cnt != type)
1377 continue;
1378 switch (cnt) {
1379 case USRQUOTA:
1380 id = inode->i_uid;
1381 break;
1382 case GRPQUOTA:
1383 id = inode->i_gid;
1384 break;
1386 got[cnt] = dqget(sb, id, cnt);
1389 down_write(&sb_dqopt(sb)->dqptr_sem);
1390 if (IS_NOQUOTA(inode))
1391 goto out_err;
1392 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1393 if (type != -1 && cnt != type)
1394 continue;
1395 /* Avoid races with quotaoff() */
1396 if (!sb_has_quota_active(sb, cnt))
1397 continue;
1398 /* We could race with quotaon or dqget() could have failed */
1399 if (!got[cnt])
1400 continue;
1401 if (!inode->i_dquot[cnt]) {
1402 inode->i_dquot[cnt] = got[cnt];
1403 got[cnt] = NULL;
1405 * Make quota reservation system happy if someone
1406 * did a write before quota was turned on
1408 rsv = inode_get_rsv_space(inode);
1409 if (unlikely(rsv))
1410 dquot_resv_space(inode->i_dquot[cnt], rsv);
1413 out_err:
1414 up_write(&sb_dqopt(sb)->dqptr_sem);
1415 /* Drop unused references */
1416 dqput_all(got);
1419 void dquot_initialize(struct inode *inode)
1421 __dquot_initialize(inode, -1);
1423 EXPORT_SYMBOL(dquot_initialize);
1426 * Release all quotas referenced by inode
1428 static void __dquot_drop(struct inode *inode)
1430 int cnt;
1431 struct dquot *put[MAXQUOTAS];
1433 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1434 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1435 put[cnt] = inode->i_dquot[cnt];
1436 inode->i_dquot[cnt] = NULL;
1438 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1439 dqput_all(put);
1442 void dquot_drop(struct inode *inode)
1444 int cnt;
1446 if (IS_NOQUOTA(inode))
1447 return;
1450 * Test before calling to rule out calls from proc and such
1451 * where we are not allowed to block. Note that this is
1452 * actually reliable test even without the lock - the caller
1453 * must assure that nobody can come after the DQUOT_DROP and
1454 * add quota pointers back anyway.
1456 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1457 if (inode->i_dquot[cnt])
1458 break;
1461 if (cnt < MAXQUOTAS)
1462 __dquot_drop(inode);
1464 EXPORT_SYMBOL(dquot_drop);
1467 * inode_reserved_space is managed internally by quota, and protected by
1468 * i_lock similar to i_blocks+i_bytes.
1470 static qsize_t *inode_reserved_space(struct inode * inode)
1472 /* Filesystem must explicitly define it's own method in order to use
1473 * quota reservation interface */
1474 BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1475 return inode->i_sb->dq_op->get_reserved_space(inode);
1478 void inode_add_rsv_space(struct inode *inode, qsize_t number)
1480 spin_lock(&inode->i_lock);
1481 *inode_reserved_space(inode) += number;
1482 spin_unlock(&inode->i_lock);
1484 EXPORT_SYMBOL(inode_add_rsv_space);
1486 void inode_claim_rsv_space(struct inode *inode, qsize_t number)
1488 spin_lock(&inode->i_lock);
1489 *inode_reserved_space(inode) -= number;
1490 __inode_add_bytes(inode, number);
1491 spin_unlock(&inode->i_lock);
1493 EXPORT_SYMBOL(inode_claim_rsv_space);
1495 void inode_sub_rsv_space(struct inode *inode, qsize_t number)
1497 spin_lock(&inode->i_lock);
1498 *inode_reserved_space(inode) -= number;
1499 spin_unlock(&inode->i_lock);
1501 EXPORT_SYMBOL(inode_sub_rsv_space);
1503 static qsize_t inode_get_rsv_space(struct inode *inode)
1505 qsize_t ret;
1507 if (!inode->i_sb->dq_op->get_reserved_space)
1508 return 0;
1509 spin_lock(&inode->i_lock);
1510 ret = *inode_reserved_space(inode);
1511 spin_unlock(&inode->i_lock);
1512 return ret;
1515 static void inode_incr_space(struct inode *inode, qsize_t number,
1516 int reserve)
1518 if (reserve)
1519 inode_add_rsv_space(inode, number);
1520 else
1521 inode_add_bytes(inode, number);
1524 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve)
1526 if (reserve)
1527 inode_sub_rsv_space(inode, number);
1528 else
1529 inode_sub_bytes(inode, number);
1533 * This functions updates i_blocks+i_bytes fields and quota information
1534 * (together with appropriate checks).
1536 * NOTE: We absolutely rely on the fact that caller dirties the inode
1537 * (usually helpers in quotaops.h care about this) and holds a handle for
1538 * the current transaction so that dquot write and inode write go into the
1539 * same transaction.
1543 * This operation can block, but only after everything is updated
1545 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
1547 int cnt, ret = 0;
1548 char warntype[MAXQUOTAS];
1549 int warn = flags & DQUOT_SPACE_WARN;
1550 int reserve = flags & DQUOT_SPACE_RESERVE;
1551 int nofail = flags & DQUOT_SPACE_NOFAIL;
1554 * First test before acquiring mutex - solves deadlocks when we
1555 * re-enter the quota code and are already holding the mutex
1557 if (!dquot_active(inode)) {
1558 inode_incr_space(inode, number, reserve);
1559 goto out;
1562 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1563 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1564 warntype[cnt] = QUOTA_NL_NOWARN;
1566 spin_lock(&dq_data_lock);
1567 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1568 if (!inode->i_dquot[cnt])
1569 continue;
1570 ret = check_bdq(inode->i_dquot[cnt], number, !warn,
1571 warntype+cnt);
1572 if (ret && !nofail) {
1573 spin_unlock(&dq_data_lock);
1574 goto out_flush_warn;
1577 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1578 if (!inode->i_dquot[cnt])
1579 continue;
1580 if (reserve)
1581 dquot_resv_space(inode->i_dquot[cnt], number);
1582 else
1583 dquot_incr_space(inode->i_dquot[cnt], number);
1585 inode_incr_space(inode, number, reserve);
1586 spin_unlock(&dq_data_lock);
1588 if (reserve)
1589 goto out_flush_warn;
1590 mark_all_dquot_dirty(inode->i_dquot);
1591 out_flush_warn:
1592 flush_warnings(inode->i_dquot, warntype);
1593 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1594 out:
1595 return ret;
1597 EXPORT_SYMBOL(__dquot_alloc_space);
1600 * This operation can block, but only after everything is updated
1602 int dquot_alloc_inode(const struct inode *inode)
1604 int cnt, ret = 0;
1605 char warntype[MAXQUOTAS];
1607 /* First test before acquiring mutex - solves deadlocks when we
1608 * re-enter the quota code and are already holding the mutex */
1609 if (!dquot_active(inode))
1610 return 0;
1611 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1612 warntype[cnt] = QUOTA_NL_NOWARN;
1613 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1614 spin_lock(&dq_data_lock);
1615 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1616 if (!inode->i_dquot[cnt])
1617 continue;
1618 ret = check_idq(inode->i_dquot[cnt], 1, warntype + cnt);
1619 if (ret)
1620 goto warn_put_all;
1623 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1624 if (!inode->i_dquot[cnt])
1625 continue;
1626 dquot_incr_inodes(inode->i_dquot[cnt], 1);
1629 warn_put_all:
1630 spin_unlock(&dq_data_lock);
1631 if (ret == 0)
1632 mark_all_dquot_dirty(inode->i_dquot);
1633 flush_warnings(inode->i_dquot, warntype);
1634 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1635 return ret;
1637 EXPORT_SYMBOL(dquot_alloc_inode);
1640 * Convert in-memory reserved quotas to real consumed quotas
1642 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
1644 int cnt;
1646 if (!dquot_active(inode)) {
1647 inode_claim_rsv_space(inode, number);
1648 return 0;
1651 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1652 spin_lock(&dq_data_lock);
1653 /* Claim reserved quotas to allocated quotas */
1654 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1655 if (inode->i_dquot[cnt])
1656 dquot_claim_reserved_space(inode->i_dquot[cnt],
1657 number);
1659 /* Update inode bytes */
1660 inode_claim_rsv_space(inode, number);
1661 spin_unlock(&dq_data_lock);
1662 mark_all_dquot_dirty(inode->i_dquot);
1663 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1664 return 0;
1666 EXPORT_SYMBOL(dquot_claim_space_nodirty);
1669 * This operation can block, but only after everything is updated
1671 void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
1673 unsigned int cnt;
1674 char warntype[MAXQUOTAS];
1675 int reserve = flags & DQUOT_SPACE_RESERVE;
1677 /* First test before acquiring mutex - solves deadlocks when we
1678 * re-enter the quota code and are already holding the mutex */
1679 if (!dquot_active(inode)) {
1680 inode_decr_space(inode, number, reserve);
1681 return;
1684 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1685 spin_lock(&dq_data_lock);
1686 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1687 if (!inode->i_dquot[cnt])
1688 continue;
1689 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
1690 if (reserve)
1691 dquot_free_reserved_space(inode->i_dquot[cnt], number);
1692 else
1693 dquot_decr_space(inode->i_dquot[cnt], number);
1695 inode_decr_space(inode, number, reserve);
1696 spin_unlock(&dq_data_lock);
1698 if (reserve)
1699 goto out_unlock;
1700 mark_all_dquot_dirty(inode->i_dquot);
1701 out_unlock:
1702 flush_warnings(inode->i_dquot, warntype);
1703 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1705 EXPORT_SYMBOL(__dquot_free_space);
1708 * This operation can block, but only after everything is updated
1710 void dquot_free_inode(const struct inode *inode)
1712 unsigned int cnt;
1713 char warntype[MAXQUOTAS];
1715 /* First test before acquiring mutex - solves deadlocks when we
1716 * re-enter the quota code and are already holding the mutex */
1717 if (!dquot_active(inode))
1718 return;
1720 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1721 spin_lock(&dq_data_lock);
1722 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1723 if (!inode->i_dquot[cnt])
1724 continue;
1725 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], 1);
1726 dquot_decr_inodes(inode->i_dquot[cnt], 1);
1728 spin_unlock(&dq_data_lock);
1729 mark_all_dquot_dirty(inode->i_dquot);
1730 flush_warnings(inode->i_dquot, warntype);
1731 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1733 EXPORT_SYMBOL(dquot_free_inode);
1736 * Transfer the number of inode and blocks from one diskquota to an other.
1737 * On success, dquot references in transfer_to are consumed and references
1738 * to original dquots that need to be released are placed there. On failure,
1739 * references are kept untouched.
1741 * This operation can block, but only after everything is updated
1742 * A transaction must be started when entering this function.
1745 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
1747 qsize_t space, cur_space;
1748 qsize_t rsv_space = 0;
1749 struct dquot *transfer_from[MAXQUOTAS] = {};
1750 int cnt, ret = 0;
1751 char is_valid[MAXQUOTAS] = {};
1752 char warntype_to[MAXQUOTAS];
1753 char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
1755 /* First test before acquiring mutex - solves deadlocks when we
1756 * re-enter the quota code and are already holding the mutex */
1757 if (IS_NOQUOTA(inode))
1758 return 0;
1759 /* Initialize the arrays */
1760 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1761 warntype_to[cnt] = QUOTA_NL_NOWARN;
1762 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1763 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */
1764 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1765 return 0;
1767 spin_lock(&dq_data_lock);
1768 cur_space = inode_get_bytes(inode);
1769 rsv_space = inode_get_rsv_space(inode);
1770 space = cur_space + rsv_space;
1771 /* Build the transfer_from list and check the limits */
1772 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1774 * Skip changes for same uid or gid or for turned off quota-type.
1776 if (!transfer_to[cnt])
1777 continue;
1778 /* Avoid races with quotaoff() */
1779 if (!sb_has_quota_active(inode->i_sb, cnt))
1780 continue;
1781 is_valid[cnt] = 1;
1782 transfer_from[cnt] = inode->i_dquot[cnt];
1783 ret = check_idq(transfer_to[cnt], 1, warntype_to + cnt);
1784 if (ret)
1785 goto over_quota;
1786 ret = check_bdq(transfer_to[cnt], space, 0, warntype_to + cnt);
1787 if (ret)
1788 goto over_quota;
1792 * Finally perform the needed transfer from transfer_from to transfer_to
1794 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1795 if (!is_valid[cnt])
1796 continue;
1797 /* Due to IO error we might not have transfer_from[] structure */
1798 if (transfer_from[cnt]) {
1799 warntype_from_inodes[cnt] =
1800 info_idq_free(transfer_from[cnt], 1);
1801 warntype_from_space[cnt] =
1802 info_bdq_free(transfer_from[cnt], space);
1803 dquot_decr_inodes(transfer_from[cnt], 1);
1804 dquot_decr_space(transfer_from[cnt], cur_space);
1805 dquot_free_reserved_space(transfer_from[cnt],
1806 rsv_space);
1809 dquot_incr_inodes(transfer_to[cnt], 1);
1810 dquot_incr_space(transfer_to[cnt], cur_space);
1811 dquot_resv_space(transfer_to[cnt], rsv_space);
1813 inode->i_dquot[cnt] = transfer_to[cnt];
1815 spin_unlock(&dq_data_lock);
1816 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1818 mark_all_dquot_dirty(transfer_from);
1819 mark_all_dquot_dirty(transfer_to);
1820 flush_warnings(transfer_to, warntype_to);
1821 flush_warnings(transfer_from, warntype_from_inodes);
1822 flush_warnings(transfer_from, warntype_from_space);
1823 /* Pass back references to put */
1824 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1825 if (is_valid[cnt])
1826 transfer_to[cnt] = transfer_from[cnt];
1827 return 0;
1828 over_quota:
1829 spin_unlock(&dq_data_lock);
1830 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1831 flush_warnings(transfer_to, warntype_to);
1832 return ret;
1834 EXPORT_SYMBOL(__dquot_transfer);
1836 /* Wrapper for transferring ownership of an inode for uid/gid only
1837 * Called from FSXXX_setattr()
1839 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1841 struct dquot *transfer_to[MAXQUOTAS] = {};
1842 struct super_block *sb = inode->i_sb;
1843 int ret;
1845 if (!dquot_active(inode))
1846 return 0;
1848 if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid)
1849 transfer_to[USRQUOTA] = dqget(sb, iattr->ia_uid, USRQUOTA);
1850 if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)
1851 transfer_to[GRPQUOTA] = dqget(sb, iattr->ia_gid, GRPQUOTA);
1853 ret = __dquot_transfer(inode, transfer_to);
1854 dqput_all(transfer_to);
1855 return ret;
1857 EXPORT_SYMBOL(dquot_transfer);
1860 * Write info of quota file to disk
1862 int dquot_commit_info(struct super_block *sb, int type)
1864 int ret;
1865 struct quota_info *dqopt = sb_dqopt(sb);
1867 mutex_lock(&dqopt->dqio_mutex);
1868 ret = dqopt->ops[type]->write_file_info(sb, type);
1869 mutex_unlock(&dqopt->dqio_mutex);
1870 return ret;
1872 EXPORT_SYMBOL(dquot_commit_info);
1875 * Definitions of diskquota operations.
1877 const struct dquot_operations dquot_operations = {
1878 .write_dquot = dquot_commit,
1879 .acquire_dquot = dquot_acquire,
1880 .release_dquot = dquot_release,
1881 .mark_dirty = dquot_mark_dquot_dirty,
1882 .write_info = dquot_commit_info,
1883 .alloc_dquot = dquot_alloc,
1884 .destroy_dquot = dquot_destroy,
1886 EXPORT_SYMBOL(dquot_operations);
1889 * Generic helper for ->open on filesystems supporting disk quotas.
1891 int dquot_file_open(struct inode *inode, struct file *file)
1893 int error;
1895 error = generic_file_open(inode, file);
1896 if (!error && (file->f_mode & FMODE_WRITE))
1897 dquot_initialize(inode);
1898 return error;
1900 EXPORT_SYMBOL(dquot_file_open);
1903 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1905 int dquot_disable(struct super_block *sb, int type, unsigned int flags)
1907 int cnt, ret = 0;
1908 struct quota_info *dqopt = sb_dqopt(sb);
1909 struct inode *toputinode[MAXQUOTAS];
1911 /* Cannot turn off usage accounting without turning off limits, or
1912 * suspend quotas and simultaneously turn quotas off. */
1913 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1914 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1915 DQUOT_USAGE_ENABLED)))
1916 return -EINVAL;
1918 /* We need to serialize quota_off() for device */
1919 mutex_lock(&dqopt->dqonoff_mutex);
1922 * Skip everything if there's nothing to do. We have to do this because
1923 * sometimes we are called when fill_super() failed and calling
1924 * sync_fs() in such cases does no good.
1926 if (!sb_any_quota_loaded(sb)) {
1927 mutex_unlock(&dqopt->dqonoff_mutex);
1928 return 0;
1930 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1931 toputinode[cnt] = NULL;
1932 if (type != -1 && cnt != type)
1933 continue;
1934 if (!sb_has_quota_loaded(sb, cnt))
1935 continue;
1937 if (flags & DQUOT_SUSPENDED) {
1938 spin_lock(&dq_state_lock);
1939 dqopt->flags |=
1940 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1941 spin_unlock(&dq_state_lock);
1942 } else {
1943 spin_lock(&dq_state_lock);
1944 dqopt->flags &= ~dquot_state_flag(flags, cnt);
1945 /* Turning off suspended quotas? */
1946 if (!sb_has_quota_loaded(sb, cnt) &&
1947 sb_has_quota_suspended(sb, cnt)) {
1948 dqopt->flags &= ~dquot_state_flag(
1949 DQUOT_SUSPENDED, cnt);
1950 spin_unlock(&dq_state_lock);
1951 iput(dqopt->files[cnt]);
1952 dqopt->files[cnt] = NULL;
1953 continue;
1955 spin_unlock(&dq_state_lock);
1958 /* We still have to keep quota loaded? */
1959 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
1960 continue;
1962 /* Note: these are blocking operations */
1963 drop_dquot_ref(sb, cnt);
1964 invalidate_dquots(sb, cnt);
1966 * Now all dquots should be invalidated, all writes done so we
1967 * should be only users of the info. No locks needed.
1969 if (info_dirty(&dqopt->info[cnt]))
1970 sb->dq_op->write_info(sb, cnt);
1971 if (dqopt->ops[cnt]->free_file_info)
1972 dqopt->ops[cnt]->free_file_info(sb, cnt);
1973 put_quota_format(dqopt->info[cnt].dqi_format);
1975 toputinode[cnt] = dqopt->files[cnt];
1976 if (!sb_has_quota_loaded(sb, cnt))
1977 dqopt->files[cnt] = NULL;
1978 dqopt->info[cnt].dqi_flags = 0;
1979 dqopt->info[cnt].dqi_igrace = 0;
1980 dqopt->info[cnt].dqi_bgrace = 0;
1981 dqopt->ops[cnt] = NULL;
1983 mutex_unlock(&dqopt->dqonoff_mutex);
1985 /* Skip syncing and setting flags if quota files are hidden */
1986 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
1987 goto put_inodes;
1989 /* Sync the superblock so that buffers with quota data are written to
1990 * disk (and so userspace sees correct data afterwards). */
1991 if (sb->s_op->sync_fs)
1992 sb->s_op->sync_fs(sb, 1);
1993 sync_blockdev(sb->s_bdev);
1994 /* Now the quota files are just ordinary files and we can set the
1995 * inode flags back. Moreover we discard the pagecache so that
1996 * userspace sees the writes we did bypassing the pagecache. We
1997 * must also discard the blockdev buffers so that we see the
1998 * changes done by userspace on the next quotaon() */
1999 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2000 if (toputinode[cnt]) {
2001 mutex_lock(&dqopt->dqonoff_mutex);
2002 /* If quota was reenabled in the meantime, we have
2003 * nothing to do */
2004 if (!sb_has_quota_loaded(sb, cnt)) {
2005 mutex_lock_nested(&toputinode[cnt]->i_mutex,
2006 I_MUTEX_QUOTA);
2007 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
2008 S_NOATIME | S_NOQUOTA);
2009 truncate_inode_pages(&toputinode[cnt]->i_data,
2011 mutex_unlock(&toputinode[cnt]->i_mutex);
2012 mark_inode_dirty_sync(toputinode[cnt]);
2014 mutex_unlock(&dqopt->dqonoff_mutex);
2016 if (sb->s_bdev)
2017 invalidate_bdev(sb->s_bdev);
2018 put_inodes:
2019 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2020 if (toputinode[cnt]) {
2021 /* On remount RO, we keep the inode pointer so that we
2022 * can reenable quota on the subsequent remount RW. We
2023 * have to check 'flags' variable and not use sb_has_
2024 * function because another quotaon / quotaoff could
2025 * change global state before we got here. We refuse
2026 * to suspend quotas when there is pending delete on
2027 * the quota file... */
2028 if (!(flags & DQUOT_SUSPENDED))
2029 iput(toputinode[cnt]);
2030 else if (!toputinode[cnt]->i_nlink)
2031 ret = -EBUSY;
2033 return ret;
2035 EXPORT_SYMBOL(dquot_disable);
2037 int dquot_quota_off(struct super_block *sb, int type)
2039 return dquot_disable(sb, type,
2040 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2042 EXPORT_SYMBOL(dquot_quota_off);
2045 * Turn quotas on on a device
2049 * Helper function to turn quotas on when we already have the inode of
2050 * quota file and no quota information is loaded.
2052 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2053 unsigned int flags)
2055 struct quota_format_type *fmt = find_quota_format(format_id);
2056 struct super_block *sb = inode->i_sb;
2057 struct quota_info *dqopt = sb_dqopt(sb);
2058 int error;
2059 int oldflags = -1;
2061 if (!fmt)
2062 return -ESRCH;
2063 if (!S_ISREG(inode->i_mode)) {
2064 error = -EACCES;
2065 goto out_fmt;
2067 if (IS_RDONLY(inode)) {
2068 error = -EROFS;
2069 goto out_fmt;
2071 if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
2072 error = -EINVAL;
2073 goto out_fmt;
2075 /* Usage always has to be set... */
2076 if (!(flags & DQUOT_USAGE_ENABLED)) {
2077 error = -EINVAL;
2078 goto out_fmt;
2081 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2082 /* As we bypass the pagecache we must now flush all the
2083 * dirty data and invalidate caches so that kernel sees
2084 * changes from userspace. It is not enough to just flush
2085 * the quota file since if blocksize < pagesize, invalidation
2086 * of the cache could fail because of other unrelated dirty
2087 * data */
2088 sync_filesystem(sb);
2089 invalidate_bdev(sb->s_bdev);
2091 mutex_lock(&dqopt->dqonoff_mutex);
2092 if (sb_has_quota_loaded(sb, type)) {
2093 error = -EBUSY;
2094 goto out_lock;
2097 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2098 /* We don't want quota and atime on quota files (deadlocks
2099 * possible) Also nobody should write to the file - we use
2100 * special IO operations which ignore the immutable bit. */
2101 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2102 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2103 S_NOQUOTA);
2104 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2105 mutex_unlock(&inode->i_mutex);
2107 * When S_NOQUOTA is set, remove dquot references as no more
2108 * references can be added
2110 __dquot_drop(inode);
2113 error = -EIO;
2114 dqopt->files[type] = igrab(inode);
2115 if (!dqopt->files[type])
2116 goto out_lock;
2117 error = -EINVAL;
2118 if (!fmt->qf_ops->check_quota_file(sb, type))
2119 goto out_file_init;
2121 dqopt->ops[type] = fmt->qf_ops;
2122 dqopt->info[type].dqi_format = fmt;
2123 dqopt->info[type].dqi_fmt_id = format_id;
2124 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2125 mutex_lock(&dqopt->dqio_mutex);
2126 error = dqopt->ops[type]->read_file_info(sb, type);
2127 if (error < 0) {
2128 mutex_unlock(&dqopt->dqio_mutex);
2129 goto out_file_init;
2131 mutex_unlock(&dqopt->dqio_mutex);
2132 spin_lock(&dq_state_lock);
2133 dqopt->flags |= dquot_state_flag(flags, type);
2134 spin_unlock(&dq_state_lock);
2136 add_dquot_ref(sb, type);
2137 mutex_unlock(&dqopt->dqonoff_mutex);
2139 return 0;
2141 out_file_init:
2142 dqopt->files[type] = NULL;
2143 iput(inode);
2144 out_lock:
2145 if (oldflags != -1) {
2146 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2147 /* Set the flags back (in the case of accidental quotaon()
2148 * on a wrong file we don't want to mess up the flags) */
2149 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2150 inode->i_flags |= oldflags;
2151 mutex_unlock(&inode->i_mutex);
2153 mutex_unlock(&dqopt->dqonoff_mutex);
2154 out_fmt:
2155 put_quota_format(fmt);
2157 return error;
2160 /* Reenable quotas on remount RW */
2161 int dquot_resume(struct super_block *sb, int type)
2163 struct quota_info *dqopt = sb_dqopt(sb);
2164 struct inode *inode;
2165 int ret = 0, cnt;
2166 unsigned int flags;
2168 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2169 if (type != -1 && cnt != type)
2170 continue;
2172 mutex_lock(&dqopt->dqonoff_mutex);
2173 if (!sb_has_quota_suspended(sb, cnt)) {
2174 mutex_unlock(&dqopt->dqonoff_mutex);
2175 continue;
2177 inode = dqopt->files[cnt];
2178 dqopt->files[cnt] = NULL;
2179 spin_lock(&dq_state_lock);
2180 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2181 DQUOT_LIMITS_ENABLED,
2182 cnt);
2183 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
2184 spin_unlock(&dq_state_lock);
2185 mutex_unlock(&dqopt->dqonoff_mutex);
2187 flags = dquot_generic_flag(flags, cnt);
2188 ret = vfs_load_quota_inode(inode, cnt,
2189 dqopt->info[cnt].dqi_fmt_id, flags);
2190 iput(inode);
2193 return ret;
2195 EXPORT_SYMBOL(dquot_resume);
2197 int dquot_quota_on(struct super_block *sb, int type, int format_id,
2198 struct path *path)
2200 int error = security_quota_on(path->dentry);
2201 if (error)
2202 return error;
2203 /* Quota file not on the same filesystem? */
2204 if (path->mnt->mnt_sb != sb)
2205 error = -EXDEV;
2206 else
2207 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2208 format_id, DQUOT_USAGE_ENABLED |
2209 DQUOT_LIMITS_ENABLED);
2210 return error;
2212 EXPORT_SYMBOL(dquot_quota_on);
2215 * More powerful function for turning on quotas allowing setting
2216 * of individual quota flags
2218 int dquot_enable(struct inode *inode, int type, int format_id,
2219 unsigned int flags)
2221 int ret = 0;
2222 struct super_block *sb = inode->i_sb;
2223 struct quota_info *dqopt = sb_dqopt(sb);
2225 /* Just unsuspend quotas? */
2226 BUG_ON(flags & DQUOT_SUSPENDED);
2228 if (!flags)
2229 return 0;
2230 /* Just updating flags needed? */
2231 if (sb_has_quota_loaded(sb, type)) {
2232 mutex_lock(&dqopt->dqonoff_mutex);
2233 /* Now do a reliable test... */
2234 if (!sb_has_quota_loaded(sb, type)) {
2235 mutex_unlock(&dqopt->dqonoff_mutex);
2236 goto load_quota;
2238 if (flags & DQUOT_USAGE_ENABLED &&
2239 sb_has_quota_usage_enabled(sb, type)) {
2240 ret = -EBUSY;
2241 goto out_lock;
2243 if (flags & DQUOT_LIMITS_ENABLED &&
2244 sb_has_quota_limits_enabled(sb, type)) {
2245 ret = -EBUSY;
2246 goto out_lock;
2248 spin_lock(&dq_state_lock);
2249 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2250 spin_unlock(&dq_state_lock);
2251 out_lock:
2252 mutex_unlock(&dqopt->dqonoff_mutex);
2253 return ret;
2256 load_quota:
2257 return vfs_load_quota_inode(inode, type, format_id, flags);
2259 EXPORT_SYMBOL(dquot_enable);
2262 * This function is used when filesystem needs to initialize quotas
2263 * during mount time.
2265 int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
2266 int format_id, int type)
2268 struct dentry *dentry;
2269 int error;
2271 mutex_lock(&sb->s_root->d_inode->i_mutex);
2272 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2273 mutex_unlock(&sb->s_root->d_inode->i_mutex);
2274 if (IS_ERR(dentry))
2275 return PTR_ERR(dentry);
2277 if (!dentry->d_inode) {
2278 error = -ENOENT;
2279 goto out;
2282 error = security_quota_on(dentry);
2283 if (!error)
2284 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2285 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2287 out:
2288 dput(dentry);
2289 return error;
2291 EXPORT_SYMBOL(dquot_quota_on_mount);
2293 static inline qsize_t qbtos(qsize_t blocks)
2295 return blocks << QIF_DQBLKSIZE_BITS;
2298 static inline qsize_t stoqb(qsize_t space)
2300 return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2303 /* Generic routine for getting common part of quota structure */
2304 static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
2306 struct mem_dqblk *dm = &dquot->dq_dqb;
2308 memset(di, 0, sizeof(*di));
2309 di->d_version = FS_DQUOT_VERSION;
2310 di->d_flags = dquot->dq_type == USRQUOTA ?
2311 FS_USER_QUOTA : FS_GROUP_QUOTA;
2312 di->d_id = dquot->dq_id;
2314 spin_lock(&dq_data_lock);
2315 di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit);
2316 di->d_blk_softlimit = stoqb(dm->dqb_bsoftlimit);
2317 di->d_ino_hardlimit = dm->dqb_ihardlimit;
2318 di->d_ino_softlimit = dm->dqb_isoftlimit;
2319 di->d_bcount = dm->dqb_curspace + dm->dqb_rsvspace;
2320 di->d_icount = dm->dqb_curinodes;
2321 di->d_btimer = dm->dqb_btime;
2322 di->d_itimer = dm->dqb_itime;
2323 spin_unlock(&dq_data_lock);
2326 int dquot_get_dqblk(struct super_block *sb, int type, qid_t id,
2327 struct fs_disk_quota *di)
2329 struct dquot *dquot;
2331 dquot = dqget(sb, id, type);
2332 if (!dquot)
2333 return -ESRCH;
2334 do_get_dqblk(dquot, di);
2335 dqput(dquot);
2337 return 0;
2339 EXPORT_SYMBOL(dquot_get_dqblk);
2341 #define VFS_FS_DQ_MASK \
2342 (FS_DQ_BCOUNT | FS_DQ_BSOFT | FS_DQ_BHARD | \
2343 FS_DQ_ICOUNT | FS_DQ_ISOFT | FS_DQ_IHARD | \
2344 FS_DQ_BTIMER | FS_DQ_ITIMER)
2346 /* Generic routine for setting common part of quota structure */
2347 static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
2349 struct mem_dqblk *dm = &dquot->dq_dqb;
2350 int check_blim = 0, check_ilim = 0;
2351 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2353 if (di->d_fieldmask & ~VFS_FS_DQ_MASK)
2354 return -EINVAL;
2356 if (((di->d_fieldmask & FS_DQ_BSOFT) &&
2357 (di->d_blk_softlimit > dqi->dqi_maxblimit)) ||
2358 ((di->d_fieldmask & FS_DQ_BHARD) &&
2359 (di->d_blk_hardlimit > dqi->dqi_maxblimit)) ||
2360 ((di->d_fieldmask & FS_DQ_ISOFT) &&
2361 (di->d_ino_softlimit > dqi->dqi_maxilimit)) ||
2362 ((di->d_fieldmask & FS_DQ_IHARD) &&
2363 (di->d_ino_hardlimit > dqi->dqi_maxilimit)))
2364 return -ERANGE;
2366 spin_lock(&dq_data_lock);
2367 if (di->d_fieldmask & FS_DQ_BCOUNT) {
2368 dm->dqb_curspace = di->d_bcount - dm->dqb_rsvspace;
2369 check_blim = 1;
2370 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2373 if (di->d_fieldmask & FS_DQ_BSOFT)
2374 dm->dqb_bsoftlimit = qbtos(di->d_blk_softlimit);
2375 if (di->d_fieldmask & FS_DQ_BHARD)
2376 dm->dqb_bhardlimit = qbtos(di->d_blk_hardlimit);
2377 if (di->d_fieldmask & (FS_DQ_BSOFT | FS_DQ_BHARD)) {
2378 check_blim = 1;
2379 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2382 if (di->d_fieldmask & FS_DQ_ICOUNT) {
2383 dm->dqb_curinodes = di->d_icount;
2384 check_ilim = 1;
2385 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2388 if (di->d_fieldmask & FS_DQ_ISOFT)
2389 dm->dqb_isoftlimit = di->d_ino_softlimit;
2390 if (di->d_fieldmask & FS_DQ_IHARD)
2391 dm->dqb_ihardlimit = di->d_ino_hardlimit;
2392 if (di->d_fieldmask & (FS_DQ_ISOFT | FS_DQ_IHARD)) {
2393 check_ilim = 1;
2394 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2397 if (di->d_fieldmask & FS_DQ_BTIMER) {
2398 dm->dqb_btime = di->d_btimer;
2399 check_blim = 1;
2400 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2403 if (di->d_fieldmask & FS_DQ_ITIMER) {
2404 dm->dqb_itime = di->d_itimer;
2405 check_ilim = 1;
2406 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2409 if (check_blim) {
2410 if (!dm->dqb_bsoftlimit ||
2411 dm->dqb_curspace < dm->dqb_bsoftlimit) {
2412 dm->dqb_btime = 0;
2413 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2414 } else if (!(di->d_fieldmask & FS_DQ_BTIMER))
2415 /* Set grace only if user hasn't provided his own... */
2416 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2418 if (check_ilim) {
2419 if (!dm->dqb_isoftlimit ||
2420 dm->dqb_curinodes < dm->dqb_isoftlimit) {
2421 dm->dqb_itime = 0;
2422 clear_bit(DQ_INODES_B, &dquot->dq_flags);
2423 } else if (!(di->d_fieldmask & FS_DQ_ITIMER))
2424 /* Set grace only if user hasn't provided his own... */
2425 dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2427 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2428 dm->dqb_isoftlimit)
2429 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2430 else
2431 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2432 spin_unlock(&dq_data_lock);
2433 mark_dquot_dirty(dquot);
2435 return 0;
2438 int dquot_set_dqblk(struct super_block *sb, int type, qid_t id,
2439 struct fs_disk_quota *di)
2441 struct dquot *dquot;
2442 int rc;
2444 dquot = dqget(sb, id, type);
2445 if (!dquot) {
2446 rc = -ESRCH;
2447 goto out;
2449 rc = do_set_dqblk(dquot, di);
2450 dqput(dquot);
2451 out:
2452 return rc;
2454 EXPORT_SYMBOL(dquot_set_dqblk);
2456 /* Generic routine for getting common part of quota file information */
2457 int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2459 struct mem_dqinfo *mi;
2461 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2462 if (!sb_has_quota_active(sb, type)) {
2463 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2464 return -ESRCH;
2466 mi = sb_dqopt(sb)->info + type;
2467 spin_lock(&dq_data_lock);
2468 ii->dqi_bgrace = mi->dqi_bgrace;
2469 ii->dqi_igrace = mi->dqi_igrace;
2470 ii->dqi_flags = mi->dqi_flags & DQF_MASK;
2471 ii->dqi_valid = IIF_ALL;
2472 spin_unlock(&dq_data_lock);
2473 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2474 return 0;
2476 EXPORT_SYMBOL(dquot_get_dqinfo);
2478 /* Generic routine for setting common part of quota file information */
2479 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2481 struct mem_dqinfo *mi;
2482 int err = 0;
2484 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2485 if (!sb_has_quota_active(sb, type)) {
2486 err = -ESRCH;
2487 goto out;
2489 mi = sb_dqopt(sb)->info + type;
2490 spin_lock(&dq_data_lock);
2491 if (ii->dqi_valid & IIF_BGRACE)
2492 mi->dqi_bgrace = ii->dqi_bgrace;
2493 if (ii->dqi_valid & IIF_IGRACE)
2494 mi->dqi_igrace = ii->dqi_igrace;
2495 if (ii->dqi_valid & IIF_FLAGS)
2496 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) |
2497 (ii->dqi_flags & DQF_MASK);
2498 spin_unlock(&dq_data_lock);
2499 mark_info_dirty(sb, type);
2500 /* Force write to disk */
2501 sb->dq_op->write_info(sb, type);
2502 out:
2503 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2504 return err;
2506 EXPORT_SYMBOL(dquot_set_dqinfo);
2508 const struct quotactl_ops dquot_quotactl_ops = {
2509 .quota_on = dquot_quota_on,
2510 .quota_off = dquot_quota_off,
2511 .quota_sync = dquot_quota_sync,
2512 .get_info = dquot_get_dqinfo,
2513 .set_info = dquot_set_dqinfo,
2514 .get_dqblk = dquot_get_dqblk,
2515 .set_dqblk = dquot_set_dqblk
2517 EXPORT_SYMBOL(dquot_quotactl_ops);
2519 static int do_proc_dqstats(struct ctl_table *table, int write,
2520 void __user *buffer, size_t *lenp, loff_t *ppos)
2522 unsigned int type = (int *)table->data - dqstats.stat;
2524 /* Update global table */
2525 dqstats.stat[type] =
2526 percpu_counter_sum_positive(&dqstats.counter[type]);
2527 return proc_dointvec(table, write, buffer, lenp, ppos);
2530 static ctl_table fs_dqstats_table[] = {
2532 .procname = "lookups",
2533 .data = &dqstats.stat[DQST_LOOKUPS],
2534 .maxlen = sizeof(int),
2535 .mode = 0444,
2536 .proc_handler = do_proc_dqstats,
2539 .procname = "drops",
2540 .data = &dqstats.stat[DQST_DROPS],
2541 .maxlen = sizeof(int),
2542 .mode = 0444,
2543 .proc_handler = do_proc_dqstats,
2546 .procname = "reads",
2547 .data = &dqstats.stat[DQST_READS],
2548 .maxlen = sizeof(int),
2549 .mode = 0444,
2550 .proc_handler = do_proc_dqstats,
2553 .procname = "writes",
2554 .data = &dqstats.stat[DQST_WRITES],
2555 .maxlen = sizeof(int),
2556 .mode = 0444,
2557 .proc_handler = do_proc_dqstats,
2560 .procname = "cache_hits",
2561 .data = &dqstats.stat[DQST_CACHE_HITS],
2562 .maxlen = sizeof(int),
2563 .mode = 0444,
2564 .proc_handler = do_proc_dqstats,
2567 .procname = "allocated_dquots",
2568 .data = &dqstats.stat[DQST_ALLOC_DQUOTS],
2569 .maxlen = sizeof(int),
2570 .mode = 0444,
2571 .proc_handler = do_proc_dqstats,
2574 .procname = "free_dquots",
2575 .data = &dqstats.stat[DQST_FREE_DQUOTS],
2576 .maxlen = sizeof(int),
2577 .mode = 0444,
2578 .proc_handler = do_proc_dqstats,
2581 .procname = "syncs",
2582 .data = &dqstats.stat[DQST_SYNCS],
2583 .maxlen = sizeof(int),
2584 .mode = 0444,
2585 .proc_handler = do_proc_dqstats,
2587 #ifdef CONFIG_PRINT_QUOTA_WARNING
2589 .procname = "warnings",
2590 .data = &flag_print_warnings,
2591 .maxlen = sizeof(int),
2592 .mode = 0644,
2593 .proc_handler = proc_dointvec,
2595 #endif
2596 { },
2599 static ctl_table fs_table[] = {
2601 .procname = "quota",
2602 .mode = 0555,
2603 .child = fs_dqstats_table,
2605 { },
2608 static ctl_table sys_table[] = {
2610 .procname = "fs",
2611 .mode = 0555,
2612 .child = fs_table,
2614 { },
2617 static int __init dquot_init(void)
2619 int i, ret;
2620 unsigned long nr_hash, order;
2622 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2624 register_sysctl_table(sys_table);
2626 dquot_cachep = kmem_cache_create("dquot",
2627 sizeof(struct dquot), sizeof(unsigned long) * 4,
2628 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2629 SLAB_MEM_SPREAD|SLAB_PANIC),
2630 NULL);
2632 order = 0;
2633 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2634 if (!dquot_hash)
2635 panic("Cannot create dquot hash table");
2637 for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
2638 ret = percpu_counter_init(&dqstats.counter[i], 0);
2639 if (ret)
2640 panic("Cannot create dquot stat counters");
2643 /* Find power-of-two hlist_heads which can fit into allocation */
2644 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2645 dq_hash_bits = 0;
2646 do {
2647 dq_hash_bits++;
2648 } while (nr_hash >> dq_hash_bits);
2649 dq_hash_bits--;
2651 nr_hash = 1UL << dq_hash_bits;
2652 dq_hash_mask = nr_hash - 1;
2653 for (i = 0; i < nr_hash; i++)
2654 INIT_HLIST_HEAD(dquot_hash + i);
2656 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2657 nr_hash, order, (PAGE_SIZE << order));
2659 register_shrinker(&dqcache_shrinker);
2661 return 0;
2663 module_init(dquot_init);