quota: Fix possible dq_flags corruption
[linux-2.6.git] / fs / quota / dquot.c
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.
11  * 
12  * Author:      Marco van Wieringen <mvw@planets.elm.net>
13  *
14  * Fixes:   Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
15  *
16  *              Revised list management to avoid races
17  *              -- Bill Hawes, <whawes@star.net>, 9/98
18  *
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
31  *
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
39  *
40  *              Added dynamic quota structure allocation
41  *              Jan Kara <jack@suse.cz> 12/2000
42  *
43  *              Rewritten quota interface. Implemented new quota format and
44  *              formats registering.
45  *              Jan Kara, <jack@suse.cz>, 2001,2002
46  *
47  *              New SMP locking.
48  *              Jan Kara, <jack@suse.cz>, 10/2002
49  *
50  *              Added journalled quota support, fix lock inversion problems
51  *              Jan Kara, <jack@suse.cz>, 2003,2004
52  *
53  * (C) Copyright 1994 - 1997 Marco van Wieringen 
54  */
55
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 <linux/writeback.h> /* for inode_lock, oddly enough.. */
80
81 #include <asm/uaccess.h>
82
83 #define __DQUOT_PARANOIA
84
85 /*
86  * There are three quota SMP locks. dq_list_lock protects all lists with quotas
87  * and quota formats, dqstats structure containing statistics about the lists
88  * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
89  * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
90  * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
91  * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
92  * modifications of quota state (on quotaon and quotaoff) and readers who care
93  * about latest values take it as well.
94  *
95  * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
96  *   dq_list_lock > dq_state_lock
97  *
98  * Note that some things (eg. sb pointer, type, id) doesn't change during
99  * the life of the dquot structure and so needn't to be protected by a lock
100  *
101  * Any operation working on dquots via inode pointers must hold dqptr_sem.  If
102  * operation is just reading pointers from inode (or not using them at all) the
103  * read lock is enough. If pointers are altered function must hold write lock.
104  * Special care needs to be taken about S_NOQUOTA inode flag (marking that
105  * inode is a quota file). Functions adding pointers from inode to dquots have
106  * to check this flag under dqptr_sem and then (if S_NOQUOTA is not set) they
107  * have to do all pointer modifications before dropping dqptr_sem. This makes
108  * sure they cannot race with quotaon which first sets S_NOQUOTA flag and
109  * then drops all pointers to dquots from an inode.
110  *
111  * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
112  * from inodes (dquot_alloc_space() and such don't check the dq_lock).
113  * Currently dquot is locked only when it is being read to memory (or space for
114  * it is being allocated) on the first dqget() and when it is being released on
115  * the last dqput(). The allocation and release oparations are serialized by
116  * the dq_lock and by checking the use count in dquot_release().  Write
117  * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
118  * spinlock to internal buffers before writing.
119  *
120  * Lock ordering (including related VFS locks) is the following:
121  *   i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
122  *   dqio_mutex
123  * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem >
124  * dqptr_sem. But filesystem has to count with the fact that functions such as
125  * dquot_alloc_space() acquire dqptr_sem and they usually have to be called
126  * from inside a transaction to keep filesystem consistency after a crash. Also
127  * filesystems usually want to do some IO on dquot from ->mark_dirty which is
128  * called with dqptr_sem held.
129  * i_mutex on quota files is special (it's below dqio_mutex)
130  */
131
132 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
133 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
134 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
135 EXPORT_SYMBOL(dq_data_lock);
136
137 static char *quotatypes[] = INITQFNAMES;
138 static struct quota_format_type *quota_formats; /* List of registered formats */
139 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
140
141 /* SLAB cache for dquot structures */
142 static struct kmem_cache *dquot_cachep;
143
144 int register_quota_format(struct quota_format_type *fmt)
145 {
146         spin_lock(&dq_list_lock);
147         fmt->qf_next = quota_formats;
148         quota_formats = fmt;
149         spin_unlock(&dq_list_lock);
150         return 0;
151 }
152 EXPORT_SYMBOL(register_quota_format);
153
154 void unregister_quota_format(struct quota_format_type *fmt)
155 {
156         struct quota_format_type **actqf;
157
158         spin_lock(&dq_list_lock);
159         for (actqf = &quota_formats; *actqf && *actqf != fmt;
160              actqf = &(*actqf)->qf_next)
161                 ;
162         if (*actqf)
163                 *actqf = (*actqf)->qf_next;
164         spin_unlock(&dq_list_lock);
165 }
166 EXPORT_SYMBOL(unregister_quota_format);
167
168 static struct quota_format_type *find_quota_format(int id)
169 {
170         struct quota_format_type *actqf;
171
172         spin_lock(&dq_list_lock);
173         for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
174              actqf = actqf->qf_next)
175                 ;
176         if (!actqf || !try_module_get(actqf->qf_owner)) {
177                 int qm;
178
179                 spin_unlock(&dq_list_lock);
180                 
181                 for (qm = 0; module_names[qm].qm_fmt_id &&
182                              module_names[qm].qm_fmt_id != id; qm++)
183                         ;
184                 if (!module_names[qm].qm_fmt_id ||
185                     request_module(module_names[qm].qm_mod_name))
186                         return NULL;
187
188                 spin_lock(&dq_list_lock);
189                 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
190                      actqf = actqf->qf_next)
191                         ;
192                 if (actqf && !try_module_get(actqf->qf_owner))
193                         actqf = NULL;
194         }
195         spin_unlock(&dq_list_lock);
196         return actqf;
197 }
198
199 static void put_quota_format(struct quota_format_type *fmt)
200 {
201         module_put(fmt->qf_owner);
202 }
203
204 /*
205  * Dquot List Management:
206  * The quota code uses three lists for dquot management: the inuse_list,
207  * free_dquots, and dquot_hash[] array. A single dquot structure may be
208  * on all three lists, depending on its current state.
209  *
210  * All dquots are placed to the end of inuse_list when first created, and this
211  * list is used for invalidate operation, which must look at every dquot.
212  *
213  * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
214  * and this list is searched whenever we need an available dquot.  Dquots are
215  * removed from the list as soon as they are used again, and
216  * dqstats.free_dquots gives the number of dquots on the list. When
217  * dquot is invalidated it's completely released from memory.
218  *
219  * Dquots with a specific identity (device, type and id) are placed on
220  * one of the dquot_hash[] hash chains. The provides an efficient search
221  * mechanism to locate a specific dquot.
222  */
223
224 static LIST_HEAD(inuse_list);
225 static LIST_HEAD(free_dquots);
226 static unsigned int dq_hash_bits, dq_hash_mask;
227 static struct hlist_head *dquot_hash;
228
229 struct dqstats dqstats;
230 EXPORT_SYMBOL(dqstats);
231
232 static qsize_t inode_get_rsv_space(struct inode *inode);
233 static void __dquot_initialize(struct inode *inode, int type);
234
235 static inline unsigned int
236 hashfn(const struct super_block *sb, unsigned int id, int type)
237 {
238         unsigned long tmp;
239
240         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
241         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
242 }
243
244 /*
245  * Following list functions expect dq_list_lock to be held
246  */
247 static inline void insert_dquot_hash(struct dquot *dquot)
248 {
249         struct hlist_head *head;
250         head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
251         hlist_add_head(&dquot->dq_hash, head);
252 }
253
254 static inline void remove_dquot_hash(struct dquot *dquot)
255 {
256         hlist_del_init(&dquot->dq_hash);
257 }
258
259 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
260                                 unsigned int id, int type)
261 {
262         struct hlist_node *node;
263         struct dquot *dquot;
264
265         hlist_for_each (node, dquot_hash+hashent) {
266                 dquot = hlist_entry(node, struct dquot, dq_hash);
267                 if (dquot->dq_sb == sb && dquot->dq_id == id &&
268                     dquot->dq_type == type)
269                         return dquot;
270         }
271         return NULL;
272 }
273
274 /* Add a dquot to the tail of the free list */
275 static inline void put_dquot_last(struct dquot *dquot)
276 {
277         list_add_tail(&dquot->dq_free, &free_dquots);
278         dqstats.free_dquots++;
279 }
280
281 static inline void remove_free_dquot(struct dquot *dquot)
282 {
283         if (list_empty(&dquot->dq_free))
284                 return;
285         list_del_init(&dquot->dq_free);
286         dqstats.free_dquots--;
287 }
288
289 static inline void put_inuse(struct dquot *dquot)
290 {
291         /* We add to the back of inuse list so we don't have to restart
292          * when traversing this list and we block */
293         list_add_tail(&dquot->dq_inuse, &inuse_list);
294         dqstats.allocated_dquots++;
295 }
296
297 static inline void remove_inuse(struct dquot *dquot)
298 {
299         dqstats.allocated_dquots--;
300         list_del(&dquot->dq_inuse);
301 }
302 /*
303  * End of list functions needing dq_list_lock
304  */
305
306 static void wait_on_dquot(struct dquot *dquot)
307 {
308         mutex_lock(&dquot->dq_lock);
309         mutex_unlock(&dquot->dq_lock);
310 }
311
312 static inline int dquot_dirty(struct dquot *dquot)
313 {
314         return test_bit(DQ_MOD_B, &dquot->dq_flags);
315 }
316
317 static inline int mark_dquot_dirty(struct dquot *dquot)
318 {
319         return dquot->dq_sb->dq_op->mark_dirty(dquot);
320 }
321
322 int dquot_mark_dquot_dirty(struct dquot *dquot)
323 {
324         spin_lock(&dq_list_lock);
325         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
326                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
327                                 info[dquot->dq_type].dqi_dirty_list);
328         spin_unlock(&dq_list_lock);
329         return 0;
330 }
331 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
332
333 /* Dirtify all the dquots - this can block when journalling */
334 static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
335 {
336         int ret, err, cnt;
337
338         ret = err = 0;
339         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
340                 if (dquot[cnt])
341                         /* Even in case of error we have to continue */
342                         ret = mark_dquot_dirty(dquot[cnt]);
343                 if (!err)
344                         err = ret;
345         }
346         return err;
347 }
348
349 static inline void dqput_all(struct dquot **dquot)
350 {
351         unsigned int cnt;
352
353         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
354                 dqput(dquot[cnt]);
355 }
356
357 /* This function needs dq_list_lock */
358 static inline int clear_dquot_dirty(struct dquot *dquot)
359 {
360         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
361                 return 0;
362         list_del_init(&dquot->dq_dirty);
363         return 1;
364 }
365
366 void mark_info_dirty(struct super_block *sb, int type)
367 {
368         set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
369 }
370 EXPORT_SYMBOL(mark_info_dirty);
371
372 /*
373  *      Read dquot from disk and alloc space for it
374  */
375
376 int dquot_acquire(struct dquot *dquot)
377 {
378         int ret = 0, ret2 = 0;
379         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
380
381         mutex_lock(&dquot->dq_lock);
382         mutex_lock(&dqopt->dqio_mutex);
383         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
384                 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
385         if (ret < 0)
386                 goto out_iolock;
387         set_bit(DQ_READ_B, &dquot->dq_flags);
388         /* Instantiate dquot if needed */
389         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
390                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
391                 /* Write the info if needed */
392                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
393                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
394                                                 dquot->dq_sb, dquot->dq_type);
395                 }
396                 if (ret < 0)
397                         goto out_iolock;
398                 if (ret2 < 0) {
399                         ret = ret2;
400                         goto out_iolock;
401                 }
402         }
403         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
404 out_iolock:
405         mutex_unlock(&dqopt->dqio_mutex);
406         mutex_unlock(&dquot->dq_lock);
407         return ret;
408 }
409 EXPORT_SYMBOL(dquot_acquire);
410
411 /*
412  *      Write dquot to disk
413  */
414 int dquot_commit(struct dquot *dquot)
415 {
416         int ret = 0, ret2 = 0;
417         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
418
419         mutex_lock(&dqopt->dqio_mutex);
420         spin_lock(&dq_list_lock);
421         if (!clear_dquot_dirty(dquot)) {
422                 spin_unlock(&dq_list_lock);
423                 goto out_sem;
424         }
425         spin_unlock(&dq_list_lock);
426         /* Inactive dquot can be only if there was error during read/init
427          * => we have better not writing it */
428         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
429                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
430                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
431                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
432                                                 dquot->dq_sb, dquot->dq_type);
433                 }
434                 if (ret >= 0)
435                         ret = ret2;
436         }
437 out_sem:
438         mutex_unlock(&dqopt->dqio_mutex);
439         return ret;
440 }
441 EXPORT_SYMBOL(dquot_commit);
442
443 /*
444  *      Release dquot
445  */
446 int dquot_release(struct dquot *dquot)
447 {
448         int ret = 0, ret2 = 0;
449         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
450
451         mutex_lock(&dquot->dq_lock);
452         /* Check whether we are not racing with some other dqget() */
453         if (atomic_read(&dquot->dq_count) > 1)
454                 goto out_dqlock;
455         mutex_lock(&dqopt->dqio_mutex);
456         if (dqopt->ops[dquot->dq_type]->release_dqblk) {
457                 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
458                 /* Write the info */
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);
462                 }
463                 if (ret >= 0)
464                         ret = ret2;
465         }
466         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
467         mutex_unlock(&dqopt->dqio_mutex);
468 out_dqlock:
469         mutex_unlock(&dquot->dq_lock);
470         return ret;
471 }
472 EXPORT_SYMBOL(dquot_release);
473
474 void dquot_destroy(struct dquot *dquot)
475 {
476         kmem_cache_free(dquot_cachep, dquot);
477 }
478 EXPORT_SYMBOL(dquot_destroy);
479
480 static inline void do_destroy_dquot(struct dquot *dquot)
481 {
482         dquot->dq_sb->dq_op->destroy_dquot(dquot);
483 }
484
485 /* Invalidate all dquots on the list. Note that this function is called after
486  * quota is disabled and pointers from inodes removed so there cannot be new
487  * quota users. There can still be some users of quotas due to inodes being
488  * just deleted or pruned by prune_icache() (those are not attached to any
489  * list) or parallel quotactl call. We have to wait for such users.
490  */
491 static void invalidate_dquots(struct super_block *sb, int type)
492 {
493         struct dquot *dquot, *tmp;
494
495 restart:
496         spin_lock(&dq_list_lock);
497         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
498                 if (dquot->dq_sb != sb)
499                         continue;
500                 if (dquot->dq_type != type)
501                         continue;
502                 /* Wait for dquot users */
503                 if (atomic_read(&dquot->dq_count)) {
504                         DEFINE_WAIT(wait);
505
506                         atomic_inc(&dquot->dq_count);
507                         prepare_to_wait(&dquot->dq_wait_unused, &wait,
508                                         TASK_UNINTERRUPTIBLE);
509                         spin_unlock(&dq_list_lock);
510                         /* Once dqput() wakes us up, we know it's time to free
511                          * the dquot.
512                          * IMPORTANT: we rely on the fact that there is always
513                          * at most one process waiting for dquot to free.
514                          * Otherwise dq_count would be > 1 and we would never
515                          * wake up.
516                          */
517                         if (atomic_read(&dquot->dq_count) > 1)
518                                 schedule();
519                         finish_wait(&dquot->dq_wait_unused, &wait);
520                         dqput(dquot);
521                         /* At this moment dquot() need not exist (it could be
522                          * reclaimed by prune_dqcache(). Hence we must
523                          * restart. */
524                         goto restart;
525                 }
526                 /*
527                  * Quota now has no users and it has been written on last
528                  * dqput()
529                  */
530                 remove_dquot_hash(dquot);
531                 remove_free_dquot(dquot);
532                 remove_inuse(dquot);
533                 do_destroy_dquot(dquot);
534         }
535         spin_unlock(&dq_list_lock);
536 }
537
538 /* Call callback for every active dquot on given filesystem */
539 int dquot_scan_active(struct super_block *sb,
540                       int (*fn)(struct dquot *dquot, unsigned long priv),
541                       unsigned long priv)
542 {
543         struct dquot *dquot, *old_dquot = NULL;
544         int ret = 0;
545
546         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
547         spin_lock(&dq_list_lock);
548         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
549                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
550                         continue;
551                 if (dquot->dq_sb != sb)
552                         continue;
553                 /* Now we have active dquot so we can just increase use count */
554                 atomic_inc(&dquot->dq_count);
555                 dqstats.lookups++;
556                 spin_unlock(&dq_list_lock);
557                 dqput(old_dquot);
558                 old_dquot = dquot;
559                 ret = fn(dquot, priv);
560                 if (ret < 0)
561                         goto out;
562                 spin_lock(&dq_list_lock);
563                 /* We are safe to continue now because our dquot could not
564                  * be moved out of the inuse list while we hold the reference */
565         }
566         spin_unlock(&dq_list_lock);
567 out:
568         dqput(old_dquot);
569         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
570         return ret;
571 }
572 EXPORT_SYMBOL(dquot_scan_active);
573
574 int vfs_quota_sync(struct super_block *sb, int type, int wait)
575 {
576         struct list_head *dirty;
577         struct dquot *dquot;
578         struct quota_info *dqopt = sb_dqopt(sb);
579         int cnt;
580
581         mutex_lock(&dqopt->dqonoff_mutex);
582         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
583                 if (type != -1 && cnt != type)
584                         continue;
585                 if (!sb_has_quota_active(sb, cnt))
586                         continue;
587                 spin_lock(&dq_list_lock);
588                 dirty = &dqopt->info[cnt].dqi_dirty_list;
589                 while (!list_empty(dirty)) {
590                         dquot = list_first_entry(dirty, struct dquot,
591                                                  dq_dirty);
592                         /* Dirty and inactive can be only bad dquot... */
593                         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
594                                 clear_dquot_dirty(dquot);
595                                 continue;
596                         }
597                         /* Now we have active dquot from which someone is
598                          * holding reference so we can safely just increase
599                          * use count */
600                         atomic_inc(&dquot->dq_count);
601                         dqstats.lookups++;
602                         spin_unlock(&dq_list_lock);
603                         sb->dq_op->write_dquot(dquot);
604                         dqput(dquot);
605                         spin_lock(&dq_list_lock);
606                 }
607                 spin_unlock(&dq_list_lock);
608         }
609
610         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
611                 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
612                     && info_dirty(&dqopt->info[cnt]))
613                         sb->dq_op->write_info(sb, cnt);
614         spin_lock(&dq_list_lock);
615         dqstats.syncs++;
616         spin_unlock(&dq_list_lock);
617         mutex_unlock(&dqopt->dqonoff_mutex);
618
619         if (!wait || (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE))
620                 return 0;
621
622         /* This is not very clever (and fast) but currently I don't know about
623          * any other simple way of getting quota data to disk and we must get
624          * them there for userspace to be visible... */
625         if (sb->s_op->sync_fs)
626                 sb->s_op->sync_fs(sb, 1);
627         sync_blockdev(sb->s_bdev);
628
629         /*
630          * Now when everything is written we can discard the pagecache so
631          * that userspace sees the changes.
632          */
633         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
634         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
635                 if (type != -1 && cnt != type)
636                         continue;
637                 if (!sb_has_quota_active(sb, cnt))
638                         continue;
639                 mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex,
640                                   I_MUTEX_QUOTA);
641                 truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
642                 mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
643         }
644         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
645
646         return 0;
647 }
648 EXPORT_SYMBOL(vfs_quota_sync);
649
650 /* Free unused dquots from cache */
651 static void prune_dqcache(int count)
652 {
653         struct list_head *head;
654         struct dquot *dquot;
655
656         head = free_dquots.prev;
657         while (head != &free_dquots && count) {
658                 dquot = list_entry(head, struct dquot, dq_free);
659                 remove_dquot_hash(dquot);
660                 remove_free_dquot(dquot);
661                 remove_inuse(dquot);
662                 do_destroy_dquot(dquot);
663                 count--;
664                 head = free_dquots.prev;
665         }
666 }
667
668 /*
669  * This is called from kswapd when we think we need some
670  * more memory
671  */
672
673 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
674 {
675         if (nr) {
676                 spin_lock(&dq_list_lock);
677                 prune_dqcache(nr);
678                 spin_unlock(&dq_list_lock);
679         }
680         return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
681 }
682
683 static struct shrinker dqcache_shrinker = {
684         .shrink = shrink_dqcache_memory,
685         .seeks = DEFAULT_SEEKS,
686 };
687
688 /*
689  * Put reference to dquot
690  * NOTE: If you change this function please check whether dqput_blocks() works right...
691  */
692 void dqput(struct dquot *dquot)
693 {
694         int ret;
695
696         if (!dquot)
697                 return;
698 #ifdef __DQUOT_PARANOIA
699         if (!atomic_read(&dquot->dq_count)) {
700                 printk("VFS: dqput: trying to free free dquot\n");
701                 printk("VFS: device %s, dquot of %s %d\n",
702                         dquot->dq_sb->s_id,
703                         quotatypes[dquot->dq_type],
704                         dquot->dq_id);
705                 BUG();
706         }
707 #endif
708         
709         spin_lock(&dq_list_lock);
710         dqstats.drops++;
711         spin_unlock(&dq_list_lock);
712 we_slept:
713         spin_lock(&dq_list_lock);
714         if (atomic_read(&dquot->dq_count) > 1) {
715                 /* We have more than one user... nothing to do */
716                 atomic_dec(&dquot->dq_count);
717                 /* Releasing dquot during quotaoff phase? */
718                 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
719                     atomic_read(&dquot->dq_count) == 1)
720                         wake_up(&dquot->dq_wait_unused);
721                 spin_unlock(&dq_list_lock);
722                 return;
723         }
724         /* Need to release dquot? */
725         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
726                 spin_unlock(&dq_list_lock);
727                 /* Commit dquot before releasing */
728                 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
729                 if (ret < 0) {
730                         printk(KERN_ERR "VFS: cannot write quota structure on "
731                                 "device %s (error %d). Quota may get out of "
732                                 "sync!\n", dquot->dq_sb->s_id, ret);
733                         /*
734                          * We clear dirty bit anyway, so that we avoid
735                          * infinite loop here
736                          */
737                         spin_lock(&dq_list_lock);
738                         clear_dquot_dirty(dquot);
739                         spin_unlock(&dq_list_lock);
740                 }
741                 goto we_slept;
742         }
743         /* Clear flag in case dquot was inactive (something bad happened) */
744         clear_dquot_dirty(dquot);
745         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
746                 spin_unlock(&dq_list_lock);
747                 dquot->dq_sb->dq_op->release_dquot(dquot);
748                 goto we_slept;
749         }
750         atomic_dec(&dquot->dq_count);
751 #ifdef __DQUOT_PARANOIA
752         /* sanity check */
753         BUG_ON(!list_empty(&dquot->dq_free));
754 #endif
755         put_dquot_last(dquot);
756         spin_unlock(&dq_list_lock);
757 }
758 EXPORT_SYMBOL(dqput);
759
760 struct dquot *dquot_alloc(struct super_block *sb, int type)
761 {
762         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
763 }
764 EXPORT_SYMBOL(dquot_alloc);
765
766 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
767 {
768         struct dquot *dquot;
769
770         dquot = sb->dq_op->alloc_dquot(sb, type);
771         if(!dquot)
772                 return NULL;
773
774         mutex_init(&dquot->dq_lock);
775         INIT_LIST_HEAD(&dquot->dq_free);
776         INIT_LIST_HEAD(&dquot->dq_inuse);
777         INIT_HLIST_NODE(&dquot->dq_hash);
778         INIT_LIST_HEAD(&dquot->dq_dirty);
779         init_waitqueue_head(&dquot->dq_wait_unused);
780         dquot->dq_sb = sb;
781         dquot->dq_type = type;
782         atomic_set(&dquot->dq_count, 1);
783
784         return dquot;
785 }
786
787 /*
788  * Get reference to dquot
789  *
790  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
791  * destroying our dquot by:
792  *   a) checking for quota flags under dq_list_lock and
793  *   b) getting a reference to dquot before we release dq_list_lock
794  */
795 struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
796 {
797         unsigned int hashent = hashfn(sb, id, type);
798         struct dquot *dquot = NULL, *empty = NULL;
799
800         if (!sb_has_quota_active(sb, type))
801                 return NULL;
802 we_slept:
803         spin_lock(&dq_list_lock);
804         spin_lock(&dq_state_lock);
805         if (!sb_has_quota_active(sb, type)) {
806                 spin_unlock(&dq_state_lock);
807                 spin_unlock(&dq_list_lock);
808                 goto out;
809         }
810         spin_unlock(&dq_state_lock);
811
812         dquot = find_dquot(hashent, sb, id, type);
813         if (!dquot) {
814                 if (!empty) {
815                         spin_unlock(&dq_list_lock);
816                         empty = get_empty_dquot(sb, type);
817                         if (!empty)
818                                 schedule();     /* Try to wait for a moment... */
819                         goto we_slept;
820                 }
821                 dquot = empty;
822                 empty = NULL;
823                 dquot->dq_id = id;
824                 /* all dquots go on the inuse_list */
825                 put_inuse(dquot);
826                 /* hash it first so it can be found */
827                 insert_dquot_hash(dquot);
828                 dqstats.lookups++;
829                 spin_unlock(&dq_list_lock);
830         } else {
831                 if (!atomic_read(&dquot->dq_count))
832                         remove_free_dquot(dquot);
833                 atomic_inc(&dquot->dq_count);
834                 dqstats.cache_hits++;
835                 dqstats.lookups++;
836                 spin_unlock(&dq_list_lock);
837         }
838         /* Wait for dq_lock - after this we know that either dquot_release() is
839          * already finished or it will be canceled due to dq_count > 1 test */
840         wait_on_dquot(dquot);
841         /* Read the dquot / allocate space in quota file */
842         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) &&
843             sb->dq_op->acquire_dquot(dquot) < 0) {
844                 dqput(dquot);
845                 dquot = NULL;
846                 goto out;
847         }
848 #ifdef __DQUOT_PARANOIA
849         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
850 #endif
851 out:
852         if (empty)
853                 do_destroy_dquot(empty);
854
855         return dquot;
856 }
857 EXPORT_SYMBOL(dqget);
858
859 static int dqinit_needed(struct inode *inode, int type)
860 {
861         int cnt;
862
863         if (IS_NOQUOTA(inode))
864                 return 0;
865         if (type != -1)
866                 return !inode->i_dquot[type];
867         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
868                 if (!inode->i_dquot[cnt])
869                         return 1;
870         return 0;
871 }
872
873 /* This routine is guarded by dqonoff_mutex mutex */
874 static void add_dquot_ref(struct super_block *sb, int type)
875 {
876         struct inode *inode, *old_inode = NULL;
877 #ifdef __DQUOT_PARANOIA
878         int reserved = 0;
879 #endif
880
881         spin_lock(&inode_lock);
882         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
883                 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW))
884                         continue;
885 #ifdef __DQUOT_PARANOIA
886                 if (unlikely(inode_get_rsv_space(inode) > 0))
887                         reserved = 1;
888 #endif
889                 if (!atomic_read(&inode->i_writecount))
890                         continue;
891                 if (!dqinit_needed(inode, type))
892                         continue;
893
894                 __iget(inode);
895                 spin_unlock(&inode_lock);
896
897                 iput(old_inode);
898                 __dquot_initialize(inode, type);
899                 /* We hold a reference to 'inode' so it couldn't have been
900                  * removed from s_inodes list while we dropped the inode_lock.
901                  * We cannot iput the inode now as we can be holding the last
902                  * reference and we cannot iput it under inode_lock. So we
903                  * keep the reference and iput it later. */
904                 old_inode = inode;
905                 spin_lock(&inode_lock);
906         }
907         spin_unlock(&inode_lock);
908         iput(old_inode);
909
910 #ifdef __DQUOT_PARANOIA
911         if (reserved) {
912                 printk(KERN_WARNING "VFS (%s): Writes happened before quota"
913                         " was turned on thus quota information is probably "
914                         "inconsistent. Please run quotacheck(8).\n", sb->s_id);
915         }
916 #endif
917 }
918
919 /*
920  * Return 0 if dqput() won't block.
921  * (note that 1 doesn't necessarily mean blocking)
922  */
923 static inline int dqput_blocks(struct dquot *dquot)
924 {
925         if (atomic_read(&dquot->dq_count) <= 1)
926                 return 1;
927         return 0;
928 }
929
930 /*
931  * Remove references to dquots from inode and add dquot to list for freeing
932  * if we have the last referece to dquot
933  * We can't race with anybody because we hold dqptr_sem for writing...
934  */
935 static int remove_inode_dquot_ref(struct inode *inode, int type,
936                                   struct list_head *tofree_head)
937 {
938         struct dquot *dquot = inode->i_dquot[type];
939
940         inode->i_dquot[type] = NULL;
941         if (dquot) {
942                 if (dqput_blocks(dquot)) {
943 #ifdef __DQUOT_PARANOIA
944                         if (atomic_read(&dquot->dq_count) != 1)
945                                 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
946 #endif
947                         spin_lock(&dq_list_lock);
948                         /* As dquot must have currently users it can't be on
949                          * the free list... */
950                         list_add(&dquot->dq_free, tofree_head);
951                         spin_unlock(&dq_list_lock);
952                         return 1;
953                 }
954                 else
955                         dqput(dquot);   /* We have guaranteed we won't block */
956         }
957         return 0;
958 }
959
960 /*
961  * Free list of dquots
962  * Dquots are removed from inodes and no new references can be got so we are
963  * the only ones holding reference
964  */
965 static void put_dquot_list(struct list_head *tofree_head)
966 {
967         struct list_head *act_head;
968         struct dquot *dquot;
969
970         act_head = tofree_head->next;
971         while (act_head != tofree_head) {
972                 dquot = list_entry(act_head, struct dquot, dq_free);
973                 act_head = act_head->next;
974                 /* Remove dquot from the list so we won't have problems... */
975                 list_del_init(&dquot->dq_free);
976                 dqput(dquot);
977         }
978 }
979
980 static void remove_dquot_ref(struct super_block *sb, int type,
981                 struct list_head *tofree_head)
982 {
983         struct inode *inode;
984
985         spin_lock(&inode_lock);
986         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
987                 /*
988                  *  We have to scan also I_NEW inodes because they can already
989                  *  have quota pointer initialized. Luckily, we need to touch
990                  *  only quota pointers and these have separate locking
991                  *  (dqptr_sem).
992                  */
993                 if (!IS_NOQUOTA(inode))
994                         remove_inode_dquot_ref(inode, type, tofree_head);
995         }
996         spin_unlock(&inode_lock);
997 }
998
999 /* Gather all references from inodes and drop them */
1000 static void drop_dquot_ref(struct super_block *sb, int type)
1001 {
1002         LIST_HEAD(tofree_head);
1003
1004         if (sb->dq_op) {
1005                 down_write(&sb_dqopt(sb)->dqptr_sem);
1006                 remove_dquot_ref(sb, type, &tofree_head);
1007                 up_write(&sb_dqopt(sb)->dqptr_sem);
1008                 put_dquot_list(&tofree_head);
1009         }
1010 }
1011
1012 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
1013 {
1014         dquot->dq_dqb.dqb_curinodes += number;
1015 }
1016
1017 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
1018 {
1019         dquot->dq_dqb.dqb_curspace += number;
1020 }
1021
1022 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
1023 {
1024         dquot->dq_dqb.dqb_rsvspace += number;
1025 }
1026
1027 /*
1028  * Claim reserved quota space
1029  */
1030 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number)
1031 {
1032         if (dquot->dq_dqb.dqb_rsvspace < number) {
1033                 WARN_ON_ONCE(1);
1034                 number = dquot->dq_dqb.dqb_rsvspace;
1035         }
1036         dquot->dq_dqb.dqb_curspace += number;
1037         dquot->dq_dqb.dqb_rsvspace -= number;
1038 }
1039
1040 static inline
1041 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
1042 {
1043         if (dquot->dq_dqb.dqb_rsvspace >= number)
1044                 dquot->dq_dqb.dqb_rsvspace -= number;
1045         else {
1046                 WARN_ON_ONCE(1);
1047                 dquot->dq_dqb.dqb_rsvspace = 0;
1048         }
1049 }
1050
1051 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1052 {
1053         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1054             dquot->dq_dqb.dqb_curinodes >= number)
1055                 dquot->dq_dqb.dqb_curinodes -= number;
1056         else
1057                 dquot->dq_dqb.dqb_curinodes = 0;
1058         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1059                 dquot->dq_dqb.dqb_itime = (time_t) 0;
1060         clear_bit(DQ_INODES_B, &dquot->dq_flags);
1061 }
1062
1063 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1064 {
1065         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1066             dquot->dq_dqb.dqb_curspace >= number)
1067                 dquot->dq_dqb.dqb_curspace -= number;
1068         else
1069                 dquot->dq_dqb.dqb_curspace = 0;
1070         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1071                 dquot->dq_dqb.dqb_btime = (time_t) 0;
1072         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1073 }
1074
1075 static int warning_issued(struct dquot *dquot, const int warntype)
1076 {
1077         int flag = (warntype == QUOTA_NL_BHARDWARN ||
1078                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1079                 ((warntype == QUOTA_NL_IHARDWARN ||
1080                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1081
1082         if (!flag)
1083                 return 0;
1084         return test_and_set_bit(flag, &dquot->dq_flags);
1085 }
1086
1087 #ifdef CONFIG_PRINT_QUOTA_WARNING
1088 static int flag_print_warnings = 1;
1089
1090 static int need_print_warning(struct dquot *dquot)
1091 {
1092         if (!flag_print_warnings)
1093                 return 0;
1094
1095         switch (dquot->dq_type) {
1096                 case USRQUOTA:
1097                         return current_fsuid() == dquot->dq_id;
1098                 case GRPQUOTA:
1099                         return in_group_p(dquot->dq_id);
1100         }
1101         return 0;
1102 }
1103
1104 /* Print warning to user which exceeded quota */
1105 static void print_warning(struct dquot *dquot, const int warntype)
1106 {
1107         char *msg = NULL;
1108         struct tty_struct *tty;
1109
1110         if (warntype == QUOTA_NL_IHARDBELOW ||
1111             warntype == QUOTA_NL_ISOFTBELOW ||
1112             warntype == QUOTA_NL_BHARDBELOW ||
1113             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
1114                 return;
1115
1116         tty = get_current_tty();
1117         if (!tty)
1118                 return;
1119         tty_write_message(tty, dquot->dq_sb->s_id);
1120         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1121                 tty_write_message(tty, ": warning, ");
1122         else
1123                 tty_write_message(tty, ": write failed, ");
1124         tty_write_message(tty, quotatypes[dquot->dq_type]);
1125         switch (warntype) {
1126                 case QUOTA_NL_IHARDWARN:
1127                         msg = " file limit reached.\r\n";
1128                         break;
1129                 case QUOTA_NL_ISOFTLONGWARN:
1130                         msg = " file quota exceeded too long.\r\n";
1131                         break;
1132                 case QUOTA_NL_ISOFTWARN:
1133                         msg = " file quota exceeded.\r\n";
1134                         break;
1135                 case QUOTA_NL_BHARDWARN:
1136                         msg = " block limit reached.\r\n";
1137                         break;
1138                 case QUOTA_NL_BSOFTLONGWARN:
1139                         msg = " block quota exceeded too long.\r\n";
1140                         break;
1141                 case QUOTA_NL_BSOFTWARN:
1142                         msg = " block quota exceeded.\r\n";
1143                         break;
1144         }
1145         tty_write_message(tty, msg);
1146         tty_kref_put(tty);
1147 }
1148 #endif
1149
1150 /*
1151  * Write warnings to the console and send warning messages over netlink.
1152  *
1153  * Note that this function can sleep.
1154  */
1155 static void flush_warnings(struct dquot *const *dquots, char *warntype)
1156 {
1157         struct dquot *dq;
1158         int i;
1159
1160         for (i = 0; i < MAXQUOTAS; i++) {
1161                 dq = dquots[i];
1162                 if (dq && warntype[i] != QUOTA_NL_NOWARN &&
1163                     !warning_issued(dq, warntype[i])) {
1164 #ifdef CONFIG_PRINT_QUOTA_WARNING
1165                         print_warning(dq, warntype[i]);
1166 #endif
1167                         quota_send_warning(dq->dq_type, dq->dq_id,
1168                                            dq->dq_sb->s_dev, warntype[i]);
1169                 }
1170         }
1171 }
1172
1173 static int ignore_hardlimit(struct dquot *dquot)
1174 {
1175         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1176
1177         return capable(CAP_SYS_RESOURCE) &&
1178                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1179                 !(info->dqi_flags & V1_DQF_RSQUASH));
1180 }
1181
1182 /* needs dq_data_lock */
1183 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
1184 {
1185         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1186
1187         *warntype = QUOTA_NL_NOWARN;
1188         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1189             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1190                 return 0;
1191
1192         if (dquot->dq_dqb.dqb_ihardlimit &&
1193             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1194             !ignore_hardlimit(dquot)) {
1195                 *warntype = QUOTA_NL_IHARDWARN;
1196                 return -EDQUOT;
1197         }
1198
1199         if (dquot->dq_dqb.dqb_isoftlimit &&
1200             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1201             dquot->dq_dqb.dqb_itime &&
1202             get_seconds() >= dquot->dq_dqb.dqb_itime &&
1203             !ignore_hardlimit(dquot)) {
1204                 *warntype = QUOTA_NL_ISOFTLONGWARN;
1205                 return -EDQUOT;
1206         }
1207
1208         if (dquot->dq_dqb.dqb_isoftlimit &&
1209             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1210             dquot->dq_dqb.dqb_itime == 0) {
1211                 *warntype = QUOTA_NL_ISOFTWARN;
1212                 dquot->dq_dqb.dqb_itime = get_seconds() +
1213                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1214         }
1215
1216         return 0;
1217 }
1218
1219 /* needs dq_data_lock */
1220 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1221 {
1222         qsize_t tspace;
1223         struct super_block *sb = dquot->dq_sb;
1224
1225         *warntype = QUOTA_NL_NOWARN;
1226         if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
1227             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1228                 return 0;
1229
1230         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1231                 + space;
1232
1233         if (dquot->dq_dqb.dqb_bhardlimit &&
1234             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1235             !ignore_hardlimit(dquot)) {
1236                 if (!prealloc)
1237                         *warntype = QUOTA_NL_BHARDWARN;
1238                 return -EDQUOT;
1239         }
1240
1241         if (dquot->dq_dqb.dqb_bsoftlimit &&
1242             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1243             dquot->dq_dqb.dqb_btime &&
1244             get_seconds() >= dquot->dq_dqb.dqb_btime &&
1245             !ignore_hardlimit(dquot)) {
1246                 if (!prealloc)
1247                         *warntype = QUOTA_NL_BSOFTLONGWARN;
1248                 return -EDQUOT;
1249         }
1250
1251         if (dquot->dq_dqb.dqb_bsoftlimit &&
1252             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1253             dquot->dq_dqb.dqb_btime == 0) {
1254                 if (!prealloc) {
1255                         *warntype = QUOTA_NL_BSOFTWARN;
1256                         dquot->dq_dqb.dqb_btime = get_seconds() +
1257                             sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
1258                 }
1259                 else
1260                         /*
1261                          * We don't allow preallocation to exceed softlimit so exceeding will
1262                          * be always printed
1263                          */
1264                         return -EDQUOT;
1265         }
1266
1267         return 0;
1268 }
1269
1270 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1271 {
1272         qsize_t newinodes;
1273
1274         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1275             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1276             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
1277                 return QUOTA_NL_NOWARN;
1278
1279         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1280         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1281                 return QUOTA_NL_ISOFTBELOW;
1282         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1283             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1284                 return QUOTA_NL_IHARDBELOW;
1285         return QUOTA_NL_NOWARN;
1286 }
1287
1288 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1289 {
1290         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1291             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1292                 return QUOTA_NL_NOWARN;
1293
1294         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1295                 return QUOTA_NL_BSOFTBELOW;
1296         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1297             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1298                 return QUOTA_NL_BHARDBELOW;
1299         return QUOTA_NL_NOWARN;
1300 }
1301
1302 /*
1303  * Initialize quota pointers in inode
1304  *
1305  * We do things in a bit complicated way but by that we avoid calling
1306  * dqget() and thus filesystem callbacks under dqptr_sem.
1307  *
1308  * It is better to call this function outside of any transaction as it
1309  * might need a lot of space in journal for dquot structure allocation.
1310  */
1311 static void __dquot_initialize(struct inode *inode, int type)
1312 {
1313         unsigned int id = 0;
1314         int cnt;
1315         struct dquot *got[MAXQUOTAS];
1316         struct super_block *sb = inode->i_sb;
1317         qsize_t rsv;
1318
1319         /* First test before acquiring mutex - solves deadlocks when we
1320          * re-enter the quota code and are already holding the mutex */
1321         if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode))
1322                 return;
1323
1324         /* First get references to structures we might need. */
1325         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1326                 got[cnt] = NULL;
1327                 if (type != -1 && cnt != type)
1328                         continue;
1329                 switch (cnt) {
1330                 case USRQUOTA:
1331                         id = inode->i_uid;
1332                         break;
1333                 case GRPQUOTA:
1334                         id = inode->i_gid;
1335                         break;
1336                 }
1337                 got[cnt] = dqget(sb, id, cnt);
1338         }
1339
1340         down_write(&sb_dqopt(sb)->dqptr_sem);
1341         if (IS_NOQUOTA(inode))
1342                 goto out_err;
1343         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1344                 if (type != -1 && cnt != type)
1345                         continue;
1346                 /* Avoid races with quotaoff() */
1347                 if (!sb_has_quota_active(sb, cnt))
1348                         continue;
1349                 if (!inode->i_dquot[cnt]) {
1350                         inode->i_dquot[cnt] = got[cnt];
1351                         got[cnt] = NULL;
1352                         /*
1353                          * Make quota reservation system happy if someone
1354                          * did a write before quota was turned on
1355                          */
1356                         rsv = inode_get_rsv_space(inode);
1357                         if (unlikely(rsv))
1358                                 dquot_resv_space(inode->i_dquot[cnt], rsv);
1359                 }
1360         }
1361 out_err:
1362         up_write(&sb_dqopt(sb)->dqptr_sem);
1363         /* Drop unused references */
1364         dqput_all(got);
1365 }
1366
1367 void dquot_initialize(struct inode *inode)
1368 {
1369         __dquot_initialize(inode, -1);
1370 }
1371 EXPORT_SYMBOL(dquot_initialize);
1372
1373 /*
1374  *      Release all quotas referenced by inode
1375  */
1376 static void __dquot_drop(struct inode *inode)
1377 {
1378         int cnt;
1379         struct dquot *put[MAXQUOTAS];
1380
1381         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1382         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1383                 put[cnt] = inode->i_dquot[cnt];
1384                 inode->i_dquot[cnt] = NULL;
1385         }
1386         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1387         dqput_all(put);
1388 }
1389
1390 void dquot_drop(struct inode *inode)
1391 {
1392         int cnt;
1393
1394         if (IS_NOQUOTA(inode))
1395                 return;
1396
1397         /*
1398          * Test before calling to rule out calls from proc and such
1399          * where we are not allowed to block. Note that this is
1400          * actually reliable test even without the lock - the caller
1401          * must assure that nobody can come after the DQUOT_DROP and
1402          * add quota pointers back anyway.
1403          */
1404         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1405                 if (inode->i_dquot[cnt])
1406                         break;
1407         }
1408
1409         if (cnt < MAXQUOTAS)
1410                 __dquot_drop(inode);
1411 }
1412 EXPORT_SYMBOL(dquot_drop);
1413
1414 /*
1415  * inode_reserved_space is managed internally by quota, and protected by
1416  * i_lock similar to i_blocks+i_bytes.
1417  */
1418 static qsize_t *inode_reserved_space(struct inode * inode)
1419 {
1420         /* Filesystem must explicitly define it's own method in order to use
1421          * quota reservation interface */
1422         BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1423         return inode->i_sb->dq_op->get_reserved_space(inode);
1424 }
1425
1426 void inode_add_rsv_space(struct inode *inode, qsize_t number)
1427 {
1428         spin_lock(&inode->i_lock);
1429         *inode_reserved_space(inode) += number;
1430         spin_unlock(&inode->i_lock);
1431 }
1432 EXPORT_SYMBOL(inode_add_rsv_space);
1433
1434 void inode_claim_rsv_space(struct inode *inode, qsize_t number)
1435 {
1436         spin_lock(&inode->i_lock);
1437         *inode_reserved_space(inode) -= number;
1438         __inode_add_bytes(inode, number);
1439         spin_unlock(&inode->i_lock);
1440 }
1441 EXPORT_SYMBOL(inode_claim_rsv_space);
1442
1443 void inode_sub_rsv_space(struct inode *inode, qsize_t number)
1444 {
1445         spin_lock(&inode->i_lock);
1446         *inode_reserved_space(inode) -= number;
1447         spin_unlock(&inode->i_lock);
1448 }
1449 EXPORT_SYMBOL(inode_sub_rsv_space);
1450
1451 static qsize_t inode_get_rsv_space(struct inode *inode)
1452 {
1453         qsize_t ret;
1454
1455         if (!inode->i_sb->dq_op->get_reserved_space)
1456                 return 0;
1457         spin_lock(&inode->i_lock);
1458         ret = *inode_reserved_space(inode);
1459         spin_unlock(&inode->i_lock);
1460         return ret;
1461 }
1462
1463 static void inode_incr_space(struct inode *inode, qsize_t number,
1464                                 int reserve)
1465 {
1466         if (reserve)
1467                 inode_add_rsv_space(inode, number);
1468         else
1469                 inode_add_bytes(inode, number);
1470 }
1471
1472 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve)
1473 {
1474         if (reserve)
1475                 inode_sub_rsv_space(inode, number);
1476         else
1477                 inode_sub_bytes(inode, number);
1478 }
1479
1480 /*
1481  * This functions updates i_blocks+i_bytes fields and quota information
1482  * (together with appropriate checks).
1483  *
1484  * NOTE: We absolutely rely on the fact that caller dirties the inode
1485  * (usually helpers in quotaops.h care about this) and holds a handle for
1486  * the current transaction so that dquot write and inode write go into the
1487  * same transaction.
1488  */
1489
1490 /*
1491  * This operation can block, but only after everything is updated
1492  */
1493 int __dquot_alloc_space(struct inode *inode, qsize_t number,
1494                 int warn, int reserve)
1495 {
1496         int cnt, ret = 0;
1497         char warntype[MAXQUOTAS];
1498
1499         /*
1500          * First test before acquiring mutex - solves deadlocks when we
1501          * re-enter the quota code and are already holding the mutex
1502          */
1503         if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) {
1504                 inode_incr_space(inode, number, reserve);
1505                 goto out;
1506         }
1507
1508         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1509         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1510                 warntype[cnt] = QUOTA_NL_NOWARN;
1511
1512         spin_lock(&dq_data_lock);
1513         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1514                 if (!inode->i_dquot[cnt])
1515                         continue;
1516                 ret = check_bdq(inode->i_dquot[cnt], number, !warn,
1517                                 warntype+cnt);
1518                 if (ret) {
1519                         spin_unlock(&dq_data_lock);
1520                         goto out_flush_warn;
1521                 }
1522         }
1523         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1524                 if (!inode->i_dquot[cnt])
1525                         continue;
1526                 if (reserve)
1527                         dquot_resv_space(inode->i_dquot[cnt], number);
1528                 else
1529                         dquot_incr_space(inode->i_dquot[cnt], number);
1530         }
1531         inode_incr_space(inode, number, reserve);
1532         spin_unlock(&dq_data_lock);
1533
1534         if (reserve)
1535                 goto out_flush_warn;
1536         mark_all_dquot_dirty(inode->i_dquot);
1537 out_flush_warn:
1538         flush_warnings(inode->i_dquot, warntype);
1539         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1540 out:
1541         return ret;
1542 }
1543 EXPORT_SYMBOL(__dquot_alloc_space);
1544
1545 /*
1546  * This operation can block, but only after everything is updated
1547  */
1548 int dquot_alloc_inode(const struct inode *inode)
1549 {
1550         int cnt, ret = 0;
1551         char warntype[MAXQUOTAS];
1552
1553         /* First test before acquiring mutex - solves deadlocks when we
1554          * re-enter the quota code and are already holding the mutex */
1555         if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode))
1556                 return 0;
1557         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1558                 warntype[cnt] = QUOTA_NL_NOWARN;
1559         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1560         spin_lock(&dq_data_lock);
1561         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1562                 if (!inode->i_dquot[cnt])
1563                         continue;
1564                 ret = check_idq(inode->i_dquot[cnt], 1, warntype + cnt);
1565                 if (ret)
1566                         goto warn_put_all;
1567         }
1568
1569         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1570                 if (!inode->i_dquot[cnt])
1571                         continue;
1572                 dquot_incr_inodes(inode->i_dquot[cnt], 1);
1573         }
1574
1575 warn_put_all:
1576         spin_unlock(&dq_data_lock);
1577         if (ret == 0)
1578                 mark_all_dquot_dirty(inode->i_dquot);
1579         flush_warnings(inode->i_dquot, warntype);
1580         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1581         return ret;
1582 }
1583 EXPORT_SYMBOL(dquot_alloc_inode);
1584
1585 /*
1586  * Convert in-memory reserved quotas to real consumed quotas
1587  */
1588 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
1589 {
1590         int cnt;
1591
1592         if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) {
1593                 inode_claim_rsv_space(inode, number);
1594                 return 0;
1595         }
1596
1597         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1598         spin_lock(&dq_data_lock);
1599         /* Claim reserved quotas to allocated quotas */
1600         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1601                 if (inode->i_dquot[cnt])
1602                         dquot_claim_reserved_space(inode->i_dquot[cnt],
1603                                                         number);
1604         }
1605         /* Update inode bytes */
1606         inode_claim_rsv_space(inode, number);
1607         spin_unlock(&dq_data_lock);
1608         mark_all_dquot_dirty(inode->i_dquot);
1609         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1610         return 0;
1611 }
1612 EXPORT_SYMBOL(dquot_claim_space_nodirty);
1613
1614 /*
1615  * This operation can block, but only after everything is updated
1616  */
1617 void __dquot_free_space(struct inode *inode, qsize_t number, int reserve)
1618 {
1619         unsigned int cnt;
1620         char warntype[MAXQUOTAS];
1621
1622         /* First test before acquiring mutex - solves deadlocks when we
1623          * re-enter the quota code and are already holding the mutex */
1624         if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) {
1625                 inode_decr_space(inode, number, reserve);
1626                 return;
1627         }
1628
1629         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1630         spin_lock(&dq_data_lock);
1631         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1632                 if (!inode->i_dquot[cnt])
1633                         continue;
1634                 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
1635                 if (reserve)
1636                         dquot_free_reserved_space(inode->i_dquot[cnt], number);
1637                 else
1638                         dquot_decr_space(inode->i_dquot[cnt], number);
1639         }
1640         inode_decr_space(inode, number, reserve);
1641         spin_unlock(&dq_data_lock);
1642
1643         if (reserve)
1644                 goto out_unlock;
1645         mark_all_dquot_dirty(inode->i_dquot);
1646 out_unlock:
1647         flush_warnings(inode->i_dquot, warntype);
1648         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1649 }
1650 EXPORT_SYMBOL(__dquot_free_space);
1651
1652 /*
1653  * This operation can block, but only after everything is updated
1654  */
1655 void dquot_free_inode(const struct inode *inode)
1656 {
1657         unsigned int cnt;
1658         char warntype[MAXQUOTAS];
1659
1660         /* First test before acquiring mutex - solves deadlocks when we
1661          * re-enter the quota code and are already holding the mutex */
1662         if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode))
1663                 return;
1664
1665         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1666         spin_lock(&dq_data_lock);
1667         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1668                 if (!inode->i_dquot[cnt])
1669                         continue;
1670                 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], 1);
1671                 dquot_decr_inodes(inode->i_dquot[cnt], 1);
1672         }
1673         spin_unlock(&dq_data_lock);
1674         mark_all_dquot_dirty(inode->i_dquot);
1675         flush_warnings(inode->i_dquot, warntype);
1676         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1677 }
1678 EXPORT_SYMBOL(dquot_free_inode);
1679
1680 /*
1681  * Transfer the number of inode and blocks from one diskquota to an other.
1682  *
1683  * This operation can block, but only after everything is updated
1684  * A transaction must be started when entering this function.
1685  */
1686 static int __dquot_transfer(struct inode *inode, qid_t *chid, unsigned long mask)
1687 {
1688         qsize_t space, cur_space;
1689         qsize_t rsv_space = 0;
1690         struct dquot *transfer_from[MAXQUOTAS];
1691         struct dquot *transfer_to[MAXQUOTAS];
1692         int cnt, ret = 0;
1693         char warntype_to[MAXQUOTAS];
1694         char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
1695
1696         /* First test before acquiring mutex - solves deadlocks when we
1697          * re-enter the quota code and are already holding the mutex */
1698         if (IS_NOQUOTA(inode))
1699                 return 0;
1700         /* Initialize the arrays */
1701         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1702                 transfer_from[cnt] = NULL;
1703                 transfer_to[cnt] = NULL;
1704                 warntype_to[cnt] = QUOTA_NL_NOWARN;
1705         }
1706         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1707                 if (mask & (1 << cnt))
1708                         transfer_to[cnt] = dqget(inode->i_sb, chid[cnt], cnt);
1709         }
1710         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1711         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1712                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1713                 goto put_all;
1714         }
1715         spin_lock(&dq_data_lock);
1716         cur_space = inode_get_bytes(inode);
1717         rsv_space = inode_get_rsv_space(inode);
1718         space = cur_space + rsv_space;
1719         /* Build the transfer_from list and check the limits */
1720         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1721                 if (!transfer_to[cnt])
1722                         continue;
1723                 transfer_from[cnt] = inode->i_dquot[cnt];
1724                 ret = check_idq(transfer_to[cnt], 1, warntype_to + cnt);
1725                 if (ret)
1726                         goto over_quota;
1727                 ret = check_bdq(transfer_to[cnt], space, 0, warntype_to + cnt);
1728                 if (ret)
1729                         goto over_quota;
1730         }
1731
1732         /*
1733          * Finally perform the needed transfer from transfer_from to transfer_to
1734          */
1735         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1736                 /*
1737                  * Skip changes for same uid or gid or for turned off quota-type.
1738                  */
1739                 if (!transfer_to[cnt])
1740                         continue;
1741
1742                 /* Due to IO error we might not have transfer_from[] structure */
1743                 if (transfer_from[cnt]) {
1744                         warntype_from_inodes[cnt] =
1745                                 info_idq_free(transfer_from[cnt], 1);
1746                         warntype_from_space[cnt] =
1747                                 info_bdq_free(transfer_from[cnt], space);
1748                         dquot_decr_inodes(transfer_from[cnt], 1);
1749                         dquot_decr_space(transfer_from[cnt], cur_space);
1750                         dquot_free_reserved_space(transfer_from[cnt],
1751                                                   rsv_space);
1752                 }
1753
1754                 dquot_incr_inodes(transfer_to[cnt], 1);
1755                 dquot_incr_space(transfer_to[cnt], cur_space);
1756                 dquot_resv_space(transfer_to[cnt], rsv_space);
1757
1758                 inode->i_dquot[cnt] = transfer_to[cnt];
1759         }
1760         spin_unlock(&dq_data_lock);
1761         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1762
1763         mark_all_dquot_dirty(transfer_from);
1764         mark_all_dquot_dirty(transfer_to);
1765         /* The reference we got is transferred to the inode */
1766         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1767                 transfer_to[cnt] = NULL;
1768 warn_put_all:
1769         flush_warnings(transfer_to, warntype_to);
1770         flush_warnings(transfer_from, warntype_from_inodes);
1771         flush_warnings(transfer_from, warntype_from_space);
1772 put_all:
1773         dqput_all(transfer_from);
1774         dqput_all(transfer_to);
1775         return ret;
1776 over_quota:
1777         spin_unlock(&dq_data_lock);
1778         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1779         /* Clear dquot pointers we don't want to dqput() */
1780         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1781                 transfer_from[cnt] = NULL;
1782         goto warn_put_all;
1783 }
1784
1785 /* Wrapper for transferring ownership of an inode for uid/gid only
1786  * Called from FSXXX_setattr()
1787  */
1788 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1789 {
1790         qid_t chid[MAXQUOTAS];
1791         unsigned long mask = 0;
1792
1793         if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) {
1794                 mask |= 1 << USRQUOTA;
1795                 chid[USRQUOTA] = iattr->ia_uid;
1796         }
1797         if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid) {
1798                 mask |= 1 << GRPQUOTA;
1799                 chid[GRPQUOTA] = iattr->ia_gid;
1800         }
1801         if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) {
1802                 dquot_initialize(inode);
1803                 return __dquot_transfer(inode, chid, mask);
1804         }
1805         return 0;
1806 }
1807 EXPORT_SYMBOL(dquot_transfer);
1808
1809 /*
1810  * Write info of quota file to disk
1811  */
1812 int dquot_commit_info(struct super_block *sb, int type)
1813 {
1814         int ret;
1815         struct quota_info *dqopt = sb_dqopt(sb);
1816
1817         mutex_lock(&dqopt->dqio_mutex);
1818         ret = dqopt->ops[type]->write_file_info(sb, type);
1819         mutex_unlock(&dqopt->dqio_mutex);
1820         return ret;
1821 }
1822 EXPORT_SYMBOL(dquot_commit_info);
1823
1824 /*
1825  * Definitions of diskquota operations.
1826  */
1827 const struct dquot_operations dquot_operations = {
1828         .write_dquot    = dquot_commit,
1829         .acquire_dquot  = dquot_acquire,
1830         .release_dquot  = dquot_release,
1831         .mark_dirty     = dquot_mark_dquot_dirty,
1832         .write_info     = dquot_commit_info,
1833         .alloc_dquot    = dquot_alloc,
1834         .destroy_dquot  = dquot_destroy,
1835 };
1836
1837 /*
1838  * Generic helper for ->open on filesystems supporting disk quotas.
1839  */
1840 int dquot_file_open(struct inode *inode, struct file *file)
1841 {
1842         int error;
1843
1844         error = generic_file_open(inode, file);
1845         if (!error && (file->f_mode & FMODE_WRITE))
1846                 dquot_initialize(inode);
1847         return error;
1848 }
1849 EXPORT_SYMBOL(dquot_file_open);
1850
1851 /*
1852  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1853  */
1854 int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags)
1855 {
1856         int cnt, ret = 0;
1857         struct quota_info *dqopt = sb_dqopt(sb);
1858         struct inode *toputinode[MAXQUOTAS];
1859
1860         /* Cannot turn off usage accounting without turning off limits, or
1861          * suspend quotas and simultaneously turn quotas off. */
1862         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1863             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1864             DQUOT_USAGE_ENABLED)))
1865                 return -EINVAL;
1866
1867         /* We need to serialize quota_off() for device */
1868         mutex_lock(&dqopt->dqonoff_mutex);
1869
1870         /*
1871          * Skip everything if there's nothing to do. We have to do this because
1872          * sometimes we are called when fill_super() failed and calling
1873          * sync_fs() in such cases does no good.
1874          */
1875         if (!sb_any_quota_loaded(sb)) {
1876                 mutex_unlock(&dqopt->dqonoff_mutex);
1877                 return 0;
1878         }
1879         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1880                 toputinode[cnt] = NULL;
1881                 if (type != -1 && cnt != type)
1882                         continue;
1883                 if (!sb_has_quota_loaded(sb, cnt))
1884                         continue;
1885
1886                 if (flags & DQUOT_SUSPENDED) {
1887                         spin_lock(&dq_state_lock);
1888                         dqopt->flags |=
1889                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1890                         spin_unlock(&dq_state_lock);
1891                 } else {
1892                         spin_lock(&dq_state_lock);
1893                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
1894                         /* Turning off suspended quotas? */
1895                         if (!sb_has_quota_loaded(sb, cnt) &&
1896                             sb_has_quota_suspended(sb, cnt)) {
1897                                 dqopt->flags &= ~dquot_state_flag(
1898                                                         DQUOT_SUSPENDED, cnt);
1899                                 spin_unlock(&dq_state_lock);
1900                                 iput(dqopt->files[cnt]);
1901                                 dqopt->files[cnt] = NULL;
1902                                 continue;
1903                         }
1904                         spin_unlock(&dq_state_lock);
1905                 }
1906
1907                 /* We still have to keep quota loaded? */
1908                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
1909                         continue;
1910
1911                 /* Note: these are blocking operations */
1912                 drop_dquot_ref(sb, cnt);
1913                 invalidate_dquots(sb, cnt);
1914                 /*
1915                  * Now all dquots should be invalidated, all writes done so we
1916                  * should be only users of the info. No locks needed.
1917                  */
1918                 if (info_dirty(&dqopt->info[cnt]))
1919                         sb->dq_op->write_info(sb, cnt);
1920                 if (dqopt->ops[cnt]->free_file_info)
1921                         dqopt->ops[cnt]->free_file_info(sb, cnt);
1922                 put_quota_format(dqopt->info[cnt].dqi_format);
1923
1924                 toputinode[cnt] = dqopt->files[cnt];
1925                 if (!sb_has_quota_loaded(sb, cnt))
1926                         dqopt->files[cnt] = NULL;
1927                 dqopt->info[cnt].dqi_flags = 0;
1928                 dqopt->info[cnt].dqi_igrace = 0;
1929                 dqopt->info[cnt].dqi_bgrace = 0;
1930                 dqopt->ops[cnt] = NULL;
1931         }
1932         mutex_unlock(&dqopt->dqonoff_mutex);
1933
1934         /* Skip syncing and setting flags if quota files are hidden */
1935         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
1936                 goto put_inodes;
1937
1938         /* Sync the superblock so that buffers with quota data are written to
1939          * disk (and so userspace sees correct data afterwards). */
1940         if (sb->s_op->sync_fs)
1941                 sb->s_op->sync_fs(sb, 1);
1942         sync_blockdev(sb->s_bdev);
1943         /* Now the quota files are just ordinary files and we can set the
1944          * inode flags back. Moreover we discard the pagecache so that
1945          * userspace sees the writes we did bypassing the pagecache. We
1946          * must also discard the blockdev buffers so that we see the
1947          * changes done by userspace on the next quotaon() */
1948         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1949                 if (toputinode[cnt]) {
1950                         mutex_lock(&dqopt->dqonoff_mutex);
1951                         /* If quota was reenabled in the meantime, we have
1952                          * nothing to do */
1953                         if (!sb_has_quota_loaded(sb, cnt)) {
1954                                 mutex_lock_nested(&toputinode[cnt]->i_mutex,
1955                                                   I_MUTEX_QUOTA);
1956                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1957                                   S_NOATIME | S_NOQUOTA);
1958                                 truncate_inode_pages(&toputinode[cnt]->i_data,
1959                                                      0);
1960                                 mutex_unlock(&toputinode[cnt]->i_mutex);
1961                                 mark_inode_dirty(toputinode[cnt]);
1962                         }
1963                         mutex_unlock(&dqopt->dqonoff_mutex);
1964                 }
1965         if (sb->s_bdev)
1966                 invalidate_bdev(sb->s_bdev);
1967 put_inodes:
1968         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1969                 if (toputinode[cnt]) {
1970                         /* On remount RO, we keep the inode pointer so that we
1971                          * can reenable quota on the subsequent remount RW. We
1972                          * have to check 'flags' variable and not use sb_has_
1973                          * function because another quotaon / quotaoff could
1974                          * change global state before we got here. We refuse
1975                          * to suspend quotas when there is pending delete on
1976                          * the quota file... */
1977                         if (!(flags & DQUOT_SUSPENDED))
1978                                 iput(toputinode[cnt]);
1979                         else if (!toputinode[cnt]->i_nlink)
1980                                 ret = -EBUSY;
1981                 }
1982         return ret;
1983 }
1984 EXPORT_SYMBOL(vfs_quota_disable);
1985
1986 int vfs_quota_off(struct super_block *sb, int type, int remount)
1987 {
1988         return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED :
1989                                  (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED));
1990 }
1991 EXPORT_SYMBOL(vfs_quota_off);
1992 /*
1993  *      Turn quotas on on a device
1994  */
1995
1996 /*
1997  * Helper function to turn quotas on when we already have the inode of
1998  * quota file and no quota information is loaded.
1999  */
2000 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2001         unsigned int flags)
2002 {
2003         struct quota_format_type *fmt = find_quota_format(format_id);
2004         struct super_block *sb = inode->i_sb;
2005         struct quota_info *dqopt = sb_dqopt(sb);
2006         int error;
2007         int oldflags = -1;
2008
2009         if (!fmt)
2010                 return -ESRCH;
2011         if (!S_ISREG(inode->i_mode)) {
2012                 error = -EACCES;
2013                 goto out_fmt;
2014         }
2015         if (IS_RDONLY(inode)) {
2016                 error = -EROFS;
2017                 goto out_fmt;
2018         }
2019         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
2020                 error = -EINVAL;
2021                 goto out_fmt;
2022         }
2023         /* Usage always has to be set... */
2024         if (!(flags & DQUOT_USAGE_ENABLED)) {
2025                 error = -EINVAL;
2026                 goto out_fmt;
2027         }
2028
2029         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2030                 /* As we bypass the pagecache we must now flush all the
2031                  * dirty data and invalidate caches so that kernel sees
2032                  * changes from userspace. It is not enough to just flush
2033                  * the quota file since if blocksize < pagesize, invalidation
2034                  * of the cache could fail because of other unrelated dirty
2035                  * data */
2036                 sync_filesystem(sb);
2037                 invalidate_bdev(sb->s_bdev);
2038         }
2039         mutex_lock(&dqopt->dqonoff_mutex);
2040         if (sb_has_quota_loaded(sb, type)) {
2041                 error = -EBUSY;
2042                 goto out_lock;
2043         }
2044
2045         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2046                 /* We don't want quota and atime on quota files (deadlocks
2047                  * possible) Also nobody should write to the file - we use
2048                  * special IO operations which ignore the immutable bit. */
2049                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2050                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2051                                              S_NOQUOTA);
2052                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2053                 mutex_unlock(&inode->i_mutex);
2054                 /*
2055                  * When S_NOQUOTA is set, remove dquot references as no more
2056                  * references can be added
2057                  */
2058                 __dquot_drop(inode);
2059         }
2060
2061         error = -EIO;
2062         dqopt->files[type] = igrab(inode);
2063         if (!dqopt->files[type])
2064                 goto out_lock;
2065         error = -EINVAL;
2066         if (!fmt->qf_ops->check_quota_file(sb, type))
2067                 goto out_file_init;
2068
2069         dqopt->ops[type] = fmt->qf_ops;
2070         dqopt->info[type].dqi_format = fmt;
2071         dqopt->info[type].dqi_fmt_id = format_id;
2072         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2073         mutex_lock(&dqopt->dqio_mutex);
2074         error = dqopt->ops[type]->read_file_info(sb, type);
2075         if (error < 0) {
2076                 mutex_unlock(&dqopt->dqio_mutex);
2077                 goto out_file_init;
2078         }
2079         mutex_unlock(&dqopt->dqio_mutex);
2080         spin_lock(&dq_state_lock);
2081         dqopt->flags |= dquot_state_flag(flags, type);
2082         spin_unlock(&dq_state_lock);
2083
2084         add_dquot_ref(sb, type);
2085         mutex_unlock(&dqopt->dqonoff_mutex);
2086
2087         return 0;
2088
2089 out_file_init:
2090         dqopt->files[type] = NULL;
2091         iput(inode);
2092 out_lock:
2093         if (oldflags != -1) {
2094                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2095                 /* Set the flags back (in the case of accidental quotaon()
2096                  * on a wrong file we don't want to mess up the flags) */
2097                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2098                 inode->i_flags |= oldflags;
2099                 mutex_unlock(&inode->i_mutex);
2100         }
2101         mutex_unlock(&dqopt->dqonoff_mutex);
2102 out_fmt:
2103         put_quota_format(fmt);
2104
2105         return error; 
2106 }
2107
2108 /* Reenable quotas on remount RW */
2109 static int vfs_quota_on_remount(struct super_block *sb, int type)
2110 {
2111         struct quota_info *dqopt = sb_dqopt(sb);
2112         struct inode *inode;
2113         int ret;
2114         unsigned int flags;
2115
2116         mutex_lock(&dqopt->dqonoff_mutex);
2117         if (!sb_has_quota_suspended(sb, type)) {
2118                 mutex_unlock(&dqopt->dqonoff_mutex);
2119                 return 0;
2120         }
2121         inode = dqopt->files[type];
2122         dqopt->files[type] = NULL;
2123         spin_lock(&dq_state_lock);
2124         flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2125                                                 DQUOT_LIMITS_ENABLED, type);
2126         dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type);
2127         spin_unlock(&dq_state_lock);
2128         mutex_unlock(&dqopt->dqonoff_mutex);
2129
2130         flags = dquot_generic_flag(flags, type);
2131         ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id,
2132                                    flags);
2133         iput(inode);
2134
2135         return ret;
2136 }
2137
2138 int vfs_quota_on_path(struct super_block *sb, int type, int format_id,
2139                       struct path *path)
2140 {
2141         int error = security_quota_on(path->dentry);
2142         if (error)
2143                 return error;
2144         /* Quota file not on the same filesystem? */
2145         if (path->mnt->mnt_sb != sb)
2146                 error = -EXDEV;
2147         else
2148                 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2149                                              format_id, DQUOT_USAGE_ENABLED |
2150                                              DQUOT_LIMITS_ENABLED);
2151         return error;
2152 }
2153 EXPORT_SYMBOL(vfs_quota_on_path);
2154
2155 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name,
2156                  int remount)
2157 {
2158         struct path path;
2159         int error;
2160
2161         if (remount)
2162                 return vfs_quota_on_remount(sb, type);
2163
2164         error = kern_path(name, LOOKUP_FOLLOW, &path);
2165         if (!error) {
2166                 error = vfs_quota_on_path(sb, type, format_id, &path);
2167                 path_put(&path);
2168         }
2169         return error;
2170 }
2171 EXPORT_SYMBOL(vfs_quota_on);
2172
2173 /*
2174  * More powerful function for turning on quotas allowing setting
2175  * of individual quota flags
2176  */
2177 int vfs_quota_enable(struct inode *inode, int type, int format_id,
2178                 unsigned int flags)
2179 {
2180         int ret = 0;
2181         struct super_block *sb = inode->i_sb;
2182         struct quota_info *dqopt = sb_dqopt(sb);
2183
2184         /* Just unsuspend quotas? */
2185         if (flags & DQUOT_SUSPENDED)
2186                 return vfs_quota_on_remount(sb, type);
2187         if (!flags)
2188                 return 0;
2189         /* Just updating flags needed? */
2190         if (sb_has_quota_loaded(sb, type)) {
2191                 mutex_lock(&dqopt->dqonoff_mutex);
2192                 /* Now do a reliable test... */
2193                 if (!sb_has_quota_loaded(sb, type)) {
2194                         mutex_unlock(&dqopt->dqonoff_mutex);
2195                         goto load_quota;
2196                 }
2197                 if (flags & DQUOT_USAGE_ENABLED &&
2198                     sb_has_quota_usage_enabled(sb, type)) {
2199                         ret = -EBUSY;
2200                         goto out_lock;
2201                 }
2202                 if (flags & DQUOT_LIMITS_ENABLED &&
2203                     sb_has_quota_limits_enabled(sb, type)) {
2204                         ret = -EBUSY;
2205                         goto out_lock;
2206                 }
2207                 spin_lock(&dq_state_lock);
2208                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2209                 spin_unlock(&dq_state_lock);
2210 out_lock:
2211                 mutex_unlock(&dqopt->dqonoff_mutex);
2212                 return ret;
2213         }
2214
2215 load_quota:
2216         return vfs_load_quota_inode(inode, type, format_id, flags);
2217 }
2218 EXPORT_SYMBOL(vfs_quota_enable);
2219
2220 /*
2221  * This function is used when filesystem needs to initialize quotas
2222  * during mount time.
2223  */
2224 int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
2225                 int format_id, int type)
2226 {
2227         struct dentry *dentry;
2228         int error;
2229
2230         mutex_lock(&sb->s_root->d_inode->i_mutex);
2231         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2232         mutex_unlock(&sb->s_root->d_inode->i_mutex);
2233         if (IS_ERR(dentry))
2234                 return PTR_ERR(dentry);
2235
2236         if (!dentry->d_inode) {
2237                 error = -ENOENT;
2238                 goto out;
2239         }
2240
2241         error = security_quota_on(dentry);
2242         if (!error)
2243                 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2244                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2245
2246 out:
2247         dput(dentry);
2248         return error;
2249 }
2250 EXPORT_SYMBOL(vfs_quota_on_mount);
2251
2252 /* Wrapper to turn on quotas when remounting rw */
2253 int vfs_dq_quota_on_remount(struct super_block *sb)
2254 {
2255         int cnt;
2256         int ret = 0, err;
2257
2258         if (!sb->s_qcop || !sb->s_qcop->quota_on)
2259                 return -ENOSYS;
2260         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2261                 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1);
2262                 if (err < 0 && !ret)
2263                         ret = err;
2264         }
2265         return ret;
2266 }
2267 EXPORT_SYMBOL(vfs_dq_quota_on_remount);
2268
2269 static inline qsize_t qbtos(qsize_t blocks)
2270 {
2271         return blocks << QIF_DQBLKSIZE_BITS;
2272 }
2273
2274 static inline qsize_t stoqb(qsize_t space)
2275 {
2276         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2277 }
2278
2279 /* Generic routine for getting common part of quota structure */
2280 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
2281 {
2282         struct mem_dqblk *dm = &dquot->dq_dqb;
2283
2284         spin_lock(&dq_data_lock);
2285         di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit);
2286         di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit);
2287         di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace;
2288         di->dqb_ihardlimit = dm->dqb_ihardlimit;
2289         di->dqb_isoftlimit = dm->dqb_isoftlimit;
2290         di->dqb_curinodes = dm->dqb_curinodes;
2291         di->dqb_btime = dm->dqb_btime;
2292         di->dqb_itime = dm->dqb_itime;
2293         di->dqb_valid = QIF_ALL;
2294         spin_unlock(&dq_data_lock);
2295 }
2296
2297 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id,
2298                   struct if_dqblk *di)
2299 {
2300         struct dquot *dquot;
2301
2302         dquot = dqget(sb, id, type);
2303         if (!dquot)
2304                 return -ESRCH;
2305         do_get_dqblk(dquot, di);
2306         dqput(dquot);
2307
2308         return 0;
2309 }
2310 EXPORT_SYMBOL(vfs_get_dqblk);
2311
2312 /* Generic routine for setting common part of quota structure */
2313 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
2314 {
2315         struct mem_dqblk *dm = &dquot->dq_dqb;
2316         int check_blim = 0, check_ilim = 0;
2317         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2318
2319         if ((di->dqb_valid & QIF_BLIMITS &&
2320              (di->dqb_bhardlimit > dqi->dqi_maxblimit ||
2321               di->dqb_bsoftlimit > dqi->dqi_maxblimit)) ||
2322             (di->dqb_valid & QIF_ILIMITS &&
2323              (di->dqb_ihardlimit > dqi->dqi_maxilimit ||
2324               di->dqb_isoftlimit > dqi->dqi_maxilimit)))
2325                 return -ERANGE;
2326
2327         spin_lock(&dq_data_lock);
2328         if (di->dqb_valid & QIF_SPACE) {
2329                 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace;
2330                 check_blim = 1;
2331                 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2332         }
2333         if (di->dqb_valid & QIF_BLIMITS) {
2334                 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit);
2335                 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit);
2336                 check_blim = 1;
2337                 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2338         }
2339         if (di->dqb_valid & QIF_INODES) {
2340                 dm->dqb_curinodes = di->dqb_curinodes;
2341                 check_ilim = 1;
2342                 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2343         }
2344         if (di->dqb_valid & QIF_ILIMITS) {
2345                 dm->dqb_isoftlimit = di->dqb_isoftlimit;
2346                 dm->dqb_ihardlimit = di->dqb_ihardlimit;
2347                 check_ilim = 1;
2348                 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2349         }
2350         if (di->dqb_valid & QIF_BTIME) {
2351                 dm->dqb_btime = di->dqb_btime;
2352                 check_blim = 1;
2353                 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2354         }
2355         if (di->dqb_valid & QIF_ITIME) {
2356                 dm->dqb_itime = di->dqb_itime;
2357                 check_ilim = 1;
2358                 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2359         }
2360
2361         if (check_blim) {
2362                 if (!dm->dqb_bsoftlimit ||
2363                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2364                         dm->dqb_btime = 0;
2365                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2366                 } else if (!(di->dqb_valid & QIF_BTIME))
2367                         /* Set grace only if user hasn't provided his own... */
2368                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2369         }
2370         if (check_ilim) {
2371                 if (!dm->dqb_isoftlimit ||
2372                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2373                         dm->dqb_itime = 0;
2374                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2375                 } else if (!(di->dqb_valid & QIF_ITIME))
2376                         /* Set grace only if user hasn't provided his own... */
2377                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2378         }
2379         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2380             dm->dqb_isoftlimit)
2381                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2382         else
2383                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2384         spin_unlock(&dq_data_lock);
2385         mark_dquot_dirty(dquot);
2386
2387         return 0;
2388 }
2389
2390 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id,
2391                   struct if_dqblk *di)
2392 {
2393         struct dquot *dquot;
2394         int rc;
2395
2396         dquot = dqget(sb, id, type);
2397         if (!dquot) {
2398                 rc = -ESRCH;
2399                 goto out;
2400         }
2401         rc = do_set_dqblk(dquot, di);
2402         dqput(dquot);
2403 out:
2404         return rc;
2405 }
2406 EXPORT_SYMBOL(vfs_set_dqblk);
2407
2408 /* Generic routine for getting common part of quota file information */
2409 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2410 {
2411         struct mem_dqinfo *mi;
2412   
2413         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2414         if (!sb_has_quota_active(sb, type)) {
2415                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2416                 return -ESRCH;
2417         }
2418         mi = sb_dqopt(sb)->info + type;
2419         spin_lock(&dq_data_lock);
2420         ii->dqi_bgrace = mi->dqi_bgrace;
2421         ii->dqi_igrace = mi->dqi_igrace;
2422         ii->dqi_flags = mi->dqi_flags & DQF_MASK;
2423         ii->dqi_valid = IIF_ALL;
2424         spin_unlock(&dq_data_lock);
2425         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2426         return 0;
2427 }
2428 EXPORT_SYMBOL(vfs_get_dqinfo);
2429
2430 /* Generic routine for setting common part of quota file information */
2431 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2432 {
2433         struct mem_dqinfo *mi;
2434         int err = 0;
2435
2436         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2437         if (!sb_has_quota_active(sb, type)) {
2438                 err = -ESRCH;
2439                 goto out;
2440         }
2441         mi = sb_dqopt(sb)->info + type;
2442         spin_lock(&dq_data_lock);
2443         if (ii->dqi_valid & IIF_BGRACE)
2444                 mi->dqi_bgrace = ii->dqi_bgrace;
2445         if (ii->dqi_valid & IIF_IGRACE)
2446                 mi->dqi_igrace = ii->dqi_igrace;
2447         if (ii->dqi_valid & IIF_FLAGS)
2448                 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) |
2449                                 (ii->dqi_flags & DQF_MASK);
2450         spin_unlock(&dq_data_lock);
2451         mark_info_dirty(sb, type);
2452         /* Force write to disk */
2453         sb->dq_op->write_info(sb, type);
2454 out:
2455         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2456         return err;
2457 }
2458 EXPORT_SYMBOL(vfs_set_dqinfo);
2459
2460 const struct quotactl_ops vfs_quotactl_ops = {
2461         .quota_on       = vfs_quota_on,
2462         .quota_off      = vfs_quota_off,
2463         .quota_sync     = vfs_quota_sync,
2464         .get_info       = vfs_get_dqinfo,
2465         .set_info       = vfs_set_dqinfo,
2466         .get_dqblk      = vfs_get_dqblk,
2467         .set_dqblk      = vfs_set_dqblk
2468 };
2469
2470 static ctl_table fs_dqstats_table[] = {
2471         {
2472                 .procname       = "lookups",
2473                 .data           = &dqstats.lookups,
2474                 .maxlen         = sizeof(int),
2475                 .mode           = 0444,
2476                 .proc_handler   = proc_dointvec,
2477         },
2478         {
2479                 .procname       = "drops",
2480                 .data           = &dqstats.drops,
2481                 .maxlen         = sizeof(int),
2482                 .mode           = 0444,
2483                 .proc_handler   = proc_dointvec,
2484         },
2485         {
2486                 .procname       = "reads",
2487                 .data           = &dqstats.reads,
2488                 .maxlen         = sizeof(int),
2489                 .mode           = 0444,
2490                 .proc_handler   = proc_dointvec,
2491         },
2492         {
2493                 .procname       = "writes",
2494                 .data           = &dqstats.writes,
2495                 .maxlen         = sizeof(int),
2496                 .mode           = 0444,
2497                 .proc_handler   = proc_dointvec,
2498         },
2499         {
2500                 .procname       = "cache_hits",
2501                 .data           = &dqstats.cache_hits,
2502                 .maxlen         = sizeof(int),
2503                 .mode           = 0444,
2504                 .proc_handler   = proc_dointvec,
2505         },
2506         {
2507                 .procname       = "allocated_dquots",
2508                 .data           = &dqstats.allocated_dquots,
2509                 .maxlen         = sizeof(int),
2510                 .mode           = 0444,
2511                 .proc_handler   = proc_dointvec,
2512         },
2513         {
2514                 .procname       = "free_dquots",
2515                 .data           = &dqstats.free_dquots,
2516                 .maxlen         = sizeof(int),
2517                 .mode           = 0444,
2518                 .proc_handler   = proc_dointvec,
2519         },
2520         {
2521                 .procname       = "syncs",
2522                 .data           = &dqstats.syncs,
2523                 .maxlen         = sizeof(int),
2524                 .mode           = 0444,
2525                 .proc_handler   = proc_dointvec,
2526         },
2527 #ifdef CONFIG_PRINT_QUOTA_WARNING
2528         {
2529                 .procname       = "warnings",
2530                 .data           = &flag_print_warnings,
2531                 .maxlen         = sizeof(int),
2532                 .mode           = 0644,
2533                 .proc_handler   = proc_dointvec,
2534         },
2535 #endif
2536         { },
2537 };
2538
2539 static ctl_table fs_table[] = {
2540         {
2541                 .procname       = "quota",
2542                 .mode           = 0555,
2543                 .child          = fs_dqstats_table,
2544         },
2545         { },
2546 };
2547
2548 static ctl_table sys_table[] = {
2549         {
2550                 .procname       = "fs",
2551                 .mode           = 0555,
2552                 .child          = fs_table,
2553         },
2554         { },
2555 };
2556
2557 static int __init dquot_init(void)
2558 {
2559         int i;
2560         unsigned long nr_hash, order;
2561
2562         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2563
2564         register_sysctl_table(sys_table);
2565
2566         dquot_cachep = kmem_cache_create("dquot",
2567                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2568                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2569                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2570                         NULL);
2571
2572         order = 0;
2573         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2574         if (!dquot_hash)
2575                 panic("Cannot create dquot hash table");
2576
2577         /* Find power-of-two hlist_heads which can fit into allocation */
2578         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2579         dq_hash_bits = 0;
2580         do {
2581                 dq_hash_bits++;
2582         } while (nr_hash >> dq_hash_bits);
2583         dq_hash_bits--;
2584
2585         nr_hash = 1UL << dq_hash_bits;
2586         dq_hash_mask = nr_hash - 1;
2587         for (i = 0; i < nr_hash; i++)
2588                 INIT_HLIST_HEAD(dquot_hash + i);
2589
2590         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2591                         nr_hash, order, (PAGE_SIZE << order));
2592
2593         register_shrinker(&dqcache_shrinker);
2594
2595         return 0;
2596 }
2597 module_init(dquot_init);