Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux...
[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 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
81 #include <net/netlink.h>
82 #include <net/genetlink.h>
83 #endif
84
85 #include <asm/uaccess.h>
86
87 #define __DQUOT_PARANOIA
88
89 /*
90  * There are three quota SMP locks. dq_list_lock protects all lists with quotas
91  * and quota formats, dqstats structure containing statistics about the lists
92  * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
93  * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
94  * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
95  * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
96  * modifications of quota state (on quotaon and quotaoff) and readers who care
97  * about latest values take it as well.
98  *
99  * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
100  *   dq_list_lock > dq_state_lock
101  *
102  * Note that some things (eg. sb pointer, type, id) doesn't change during
103  * the life of the dquot structure and so needn't to be protected by a lock
104  *
105  * Any operation working on dquots via inode pointers must hold dqptr_sem.  If
106  * operation is just reading pointers from inode (or not using them at all) the
107  * read lock is enough. If pointers are altered function must hold write lock
108  * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
109  * for altering the flag i_mutex is also needed).
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 inline unsigned int
233 hashfn(const struct super_block *sb, unsigned int id, int type)
234 {
235         unsigned long tmp;
236
237         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
238         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
239 }
240
241 /*
242  * Following list functions expect dq_list_lock to be held
243  */
244 static inline void insert_dquot_hash(struct dquot *dquot)
245 {
246         struct hlist_head *head;
247         head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
248         hlist_add_head(&dquot->dq_hash, head);
249 }
250
251 static inline void remove_dquot_hash(struct dquot *dquot)
252 {
253         hlist_del_init(&dquot->dq_hash);
254 }
255
256 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
257                                 unsigned int id, int type)
258 {
259         struct hlist_node *node;
260         struct dquot *dquot;
261
262         hlist_for_each (node, dquot_hash+hashent) {
263                 dquot = hlist_entry(node, struct dquot, dq_hash);
264                 if (dquot->dq_sb == sb && dquot->dq_id == id &&
265                     dquot->dq_type == type)
266                         return dquot;
267         }
268         return NULL;
269 }
270
271 /* Add a dquot to the tail of the free list */
272 static inline void put_dquot_last(struct dquot *dquot)
273 {
274         list_add_tail(&dquot->dq_free, &free_dquots);
275         dqstats.free_dquots++;
276 }
277
278 static inline void remove_free_dquot(struct dquot *dquot)
279 {
280         if (list_empty(&dquot->dq_free))
281                 return;
282         list_del_init(&dquot->dq_free);
283         dqstats.free_dquots--;
284 }
285
286 static inline void put_inuse(struct dquot *dquot)
287 {
288         /* We add to the back of inuse list so we don't have to restart
289          * when traversing this list and we block */
290         list_add_tail(&dquot->dq_inuse, &inuse_list);
291         dqstats.allocated_dquots++;
292 }
293
294 static inline void remove_inuse(struct dquot *dquot)
295 {
296         dqstats.allocated_dquots--;
297         list_del(&dquot->dq_inuse);
298 }
299 /*
300  * End of list functions needing dq_list_lock
301  */
302
303 static void wait_on_dquot(struct dquot *dquot)
304 {
305         mutex_lock(&dquot->dq_lock);
306         mutex_unlock(&dquot->dq_lock);
307 }
308
309 static inline int dquot_dirty(struct dquot *dquot)
310 {
311         return test_bit(DQ_MOD_B, &dquot->dq_flags);
312 }
313
314 static inline int mark_dquot_dirty(struct dquot *dquot)
315 {
316         return dquot->dq_sb->dq_op->mark_dirty(dquot);
317 }
318
319 int dquot_mark_dquot_dirty(struct dquot *dquot)
320 {
321         spin_lock(&dq_list_lock);
322         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
323                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
324                                 info[dquot->dq_type].dqi_dirty_list);
325         spin_unlock(&dq_list_lock);
326         return 0;
327 }
328 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
329
330 /* This function needs dq_list_lock */
331 static inline int clear_dquot_dirty(struct dquot *dquot)
332 {
333         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
334                 return 0;
335         list_del_init(&dquot->dq_dirty);
336         return 1;
337 }
338
339 void mark_info_dirty(struct super_block *sb, int type)
340 {
341         set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
342 }
343 EXPORT_SYMBOL(mark_info_dirty);
344
345 /*
346  *      Read dquot from disk and alloc space for it
347  */
348
349 int dquot_acquire(struct dquot *dquot)
350 {
351         int ret = 0, ret2 = 0;
352         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
353
354         mutex_lock(&dquot->dq_lock);
355         mutex_lock(&dqopt->dqio_mutex);
356         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
357                 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
358         if (ret < 0)
359                 goto out_iolock;
360         set_bit(DQ_READ_B, &dquot->dq_flags);
361         /* Instantiate dquot if needed */
362         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
363                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
364                 /* Write the info if needed */
365                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
366                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
367                                                 dquot->dq_sb, dquot->dq_type);
368                 }
369                 if (ret < 0)
370                         goto out_iolock;
371                 if (ret2 < 0) {
372                         ret = ret2;
373                         goto out_iolock;
374                 }
375         }
376         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
377 out_iolock:
378         mutex_unlock(&dqopt->dqio_mutex);
379         mutex_unlock(&dquot->dq_lock);
380         return ret;
381 }
382 EXPORT_SYMBOL(dquot_acquire);
383
384 /*
385  *      Write dquot to disk
386  */
387 int dquot_commit(struct dquot *dquot)
388 {
389         int ret = 0, ret2 = 0;
390         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
391
392         mutex_lock(&dqopt->dqio_mutex);
393         spin_lock(&dq_list_lock);
394         if (!clear_dquot_dirty(dquot)) {
395                 spin_unlock(&dq_list_lock);
396                 goto out_sem;
397         }
398         spin_unlock(&dq_list_lock);
399         /* Inactive dquot can be only if there was error during read/init
400          * => we have better not writing it */
401         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
402                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
403                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
404                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
405                                                 dquot->dq_sb, dquot->dq_type);
406                 }
407                 if (ret >= 0)
408                         ret = ret2;
409         }
410 out_sem:
411         mutex_unlock(&dqopt->dqio_mutex);
412         return ret;
413 }
414 EXPORT_SYMBOL(dquot_commit);
415
416 /*
417  *      Release dquot
418  */
419 int dquot_release(struct dquot *dquot)
420 {
421         int ret = 0, ret2 = 0;
422         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
423
424         mutex_lock(&dquot->dq_lock);
425         /* Check whether we are not racing with some other dqget() */
426         if (atomic_read(&dquot->dq_count) > 1)
427                 goto out_dqlock;
428         mutex_lock(&dqopt->dqio_mutex);
429         if (dqopt->ops[dquot->dq_type]->release_dqblk) {
430                 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
431                 /* Write the info */
432                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
433                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
434                                                 dquot->dq_sb, dquot->dq_type);
435                 }
436                 if (ret >= 0)
437                         ret = ret2;
438         }
439         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
440         mutex_unlock(&dqopt->dqio_mutex);
441 out_dqlock:
442         mutex_unlock(&dquot->dq_lock);
443         return ret;
444 }
445 EXPORT_SYMBOL(dquot_release);
446
447 void dquot_destroy(struct dquot *dquot)
448 {
449         kmem_cache_free(dquot_cachep, dquot);
450 }
451 EXPORT_SYMBOL(dquot_destroy);
452
453 static inline void do_destroy_dquot(struct dquot *dquot)
454 {
455         dquot->dq_sb->dq_op->destroy_dquot(dquot);
456 }
457
458 /* Invalidate all dquots on the list. Note that this function is called after
459  * quota is disabled and pointers from inodes removed so there cannot be new
460  * quota users. There can still be some users of quotas due to inodes being
461  * just deleted or pruned by prune_icache() (those are not attached to any
462  * list) or parallel quotactl call. We have to wait for such users.
463  */
464 static void invalidate_dquots(struct super_block *sb, int type)
465 {
466         struct dquot *dquot, *tmp;
467
468 restart:
469         spin_lock(&dq_list_lock);
470         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
471                 if (dquot->dq_sb != sb)
472                         continue;
473                 if (dquot->dq_type != type)
474                         continue;
475                 /* Wait for dquot users */
476                 if (atomic_read(&dquot->dq_count)) {
477                         DEFINE_WAIT(wait);
478
479                         atomic_inc(&dquot->dq_count);
480                         prepare_to_wait(&dquot->dq_wait_unused, &wait,
481                                         TASK_UNINTERRUPTIBLE);
482                         spin_unlock(&dq_list_lock);
483                         /* Once dqput() wakes us up, we know it's time to free
484                          * the dquot.
485                          * IMPORTANT: we rely on the fact that there is always
486                          * at most one process waiting for dquot to free.
487                          * Otherwise dq_count would be > 1 and we would never
488                          * wake up.
489                          */
490                         if (atomic_read(&dquot->dq_count) > 1)
491                                 schedule();
492                         finish_wait(&dquot->dq_wait_unused, &wait);
493                         dqput(dquot);
494                         /* At this moment dquot() need not exist (it could be
495                          * reclaimed by prune_dqcache(). Hence we must
496                          * restart. */
497                         goto restart;
498                 }
499                 /*
500                  * Quota now has no users and it has been written on last
501                  * dqput()
502                  */
503                 remove_dquot_hash(dquot);
504                 remove_free_dquot(dquot);
505                 remove_inuse(dquot);
506                 do_destroy_dquot(dquot);
507         }
508         spin_unlock(&dq_list_lock);
509 }
510
511 /* Call callback for every active dquot on given filesystem */
512 int dquot_scan_active(struct super_block *sb,
513                       int (*fn)(struct dquot *dquot, unsigned long priv),
514                       unsigned long priv)
515 {
516         struct dquot *dquot, *old_dquot = NULL;
517         int ret = 0;
518
519         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
520         spin_lock(&dq_list_lock);
521         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
522                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
523                         continue;
524                 if (dquot->dq_sb != sb)
525                         continue;
526                 /* Now we have active dquot so we can just increase use count */
527                 atomic_inc(&dquot->dq_count);
528                 dqstats.lookups++;
529                 spin_unlock(&dq_list_lock);
530                 dqput(old_dquot);
531                 old_dquot = dquot;
532                 ret = fn(dquot, priv);
533                 if (ret < 0)
534                         goto out;
535                 spin_lock(&dq_list_lock);
536                 /* We are safe to continue now because our dquot could not
537                  * be moved out of the inuse list while we hold the reference */
538         }
539         spin_unlock(&dq_list_lock);
540 out:
541         dqput(old_dquot);
542         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
543         return ret;
544 }
545 EXPORT_SYMBOL(dquot_scan_active);
546
547 int vfs_quota_sync(struct super_block *sb, int type)
548 {
549         struct list_head *dirty;
550         struct dquot *dquot;
551         struct quota_info *dqopt = sb_dqopt(sb);
552         int cnt;
553
554         mutex_lock(&dqopt->dqonoff_mutex);
555         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
556                 if (type != -1 && cnt != type)
557                         continue;
558                 if (!sb_has_quota_active(sb, cnt))
559                         continue;
560                 spin_lock(&dq_list_lock);
561                 dirty = &dqopt->info[cnt].dqi_dirty_list;
562                 while (!list_empty(dirty)) {
563                         dquot = list_first_entry(dirty, struct dquot,
564                                                  dq_dirty);
565                         /* Dirty and inactive can be only bad dquot... */
566                         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
567                                 clear_dquot_dirty(dquot);
568                                 continue;
569                         }
570                         /* Now we have active dquot from which someone is
571                          * holding reference so we can safely just increase
572                          * use count */
573                         atomic_inc(&dquot->dq_count);
574                         dqstats.lookups++;
575                         spin_unlock(&dq_list_lock);
576                         sb->dq_op->write_dquot(dquot);
577                         dqput(dquot);
578                         spin_lock(&dq_list_lock);
579                 }
580                 spin_unlock(&dq_list_lock);
581         }
582
583         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
584                 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
585                     && info_dirty(&dqopt->info[cnt]))
586                         sb->dq_op->write_info(sb, cnt);
587         spin_lock(&dq_list_lock);
588         dqstats.syncs++;
589         spin_unlock(&dq_list_lock);
590         mutex_unlock(&dqopt->dqonoff_mutex);
591
592         return 0;
593 }
594 EXPORT_SYMBOL(vfs_quota_sync);
595
596 /* Free unused dquots from cache */
597 static void prune_dqcache(int count)
598 {
599         struct list_head *head;
600         struct dquot *dquot;
601
602         head = free_dquots.prev;
603         while (head != &free_dquots && count) {
604                 dquot = list_entry(head, struct dquot, dq_free);
605                 remove_dquot_hash(dquot);
606                 remove_free_dquot(dquot);
607                 remove_inuse(dquot);
608                 do_destroy_dquot(dquot);
609                 count--;
610                 head = free_dquots.prev;
611         }
612 }
613
614 /*
615  * This is called from kswapd when we think we need some
616  * more memory
617  */
618
619 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
620 {
621         if (nr) {
622                 spin_lock(&dq_list_lock);
623                 prune_dqcache(nr);
624                 spin_unlock(&dq_list_lock);
625         }
626         return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
627 }
628
629 static struct shrinker dqcache_shrinker = {
630         .shrink = shrink_dqcache_memory,
631         .seeks = DEFAULT_SEEKS,
632 };
633
634 /*
635  * Put reference to dquot
636  * NOTE: If you change this function please check whether dqput_blocks() works right...
637  */
638 void dqput(struct dquot *dquot)
639 {
640         int ret;
641
642         if (!dquot)
643                 return;
644 #ifdef __DQUOT_PARANOIA
645         if (!atomic_read(&dquot->dq_count)) {
646                 printk("VFS: dqput: trying to free free dquot\n");
647                 printk("VFS: device %s, dquot of %s %d\n",
648                         dquot->dq_sb->s_id,
649                         quotatypes[dquot->dq_type],
650                         dquot->dq_id);
651                 BUG();
652         }
653 #endif
654         
655         spin_lock(&dq_list_lock);
656         dqstats.drops++;
657         spin_unlock(&dq_list_lock);
658 we_slept:
659         spin_lock(&dq_list_lock);
660         if (atomic_read(&dquot->dq_count) > 1) {
661                 /* We have more than one user... nothing to do */
662                 atomic_dec(&dquot->dq_count);
663                 /* Releasing dquot during quotaoff phase? */
664                 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
665                     atomic_read(&dquot->dq_count) == 1)
666                         wake_up(&dquot->dq_wait_unused);
667                 spin_unlock(&dq_list_lock);
668                 return;
669         }
670         /* Need to release dquot? */
671         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
672                 spin_unlock(&dq_list_lock);
673                 /* Commit dquot before releasing */
674                 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
675                 if (ret < 0) {
676                         printk(KERN_ERR "VFS: cannot write quota structure on "
677                                 "device %s (error %d). Quota may get out of "
678                                 "sync!\n", dquot->dq_sb->s_id, ret);
679                         /*
680                          * We clear dirty bit anyway, so that we avoid
681                          * infinite loop here
682                          */
683                         spin_lock(&dq_list_lock);
684                         clear_dquot_dirty(dquot);
685                         spin_unlock(&dq_list_lock);
686                 }
687                 goto we_slept;
688         }
689         /* Clear flag in case dquot was inactive (something bad happened) */
690         clear_dquot_dirty(dquot);
691         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
692                 spin_unlock(&dq_list_lock);
693                 dquot->dq_sb->dq_op->release_dquot(dquot);
694                 goto we_slept;
695         }
696         atomic_dec(&dquot->dq_count);
697 #ifdef __DQUOT_PARANOIA
698         /* sanity check */
699         BUG_ON(!list_empty(&dquot->dq_free));
700 #endif
701         put_dquot_last(dquot);
702         spin_unlock(&dq_list_lock);
703 }
704 EXPORT_SYMBOL(dqput);
705
706 struct dquot *dquot_alloc(struct super_block *sb, int type)
707 {
708         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
709 }
710 EXPORT_SYMBOL(dquot_alloc);
711
712 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
713 {
714         struct dquot *dquot;
715
716         dquot = sb->dq_op->alloc_dquot(sb, type);
717         if(!dquot)
718                 return NULL;
719
720         mutex_init(&dquot->dq_lock);
721         INIT_LIST_HEAD(&dquot->dq_free);
722         INIT_LIST_HEAD(&dquot->dq_inuse);
723         INIT_HLIST_NODE(&dquot->dq_hash);
724         INIT_LIST_HEAD(&dquot->dq_dirty);
725         init_waitqueue_head(&dquot->dq_wait_unused);
726         dquot->dq_sb = sb;
727         dquot->dq_type = type;
728         atomic_set(&dquot->dq_count, 1);
729
730         return dquot;
731 }
732
733 /*
734  * Get reference to dquot
735  *
736  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
737  * destroying our dquot by:
738  *   a) checking for quota flags under dq_list_lock and
739  *   b) getting a reference to dquot before we release dq_list_lock
740  */
741 struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
742 {
743         unsigned int hashent = hashfn(sb, id, type);
744         struct dquot *dquot = NULL, *empty = NULL;
745
746         if (!sb_has_quota_active(sb, type))
747                 return NULL;
748 we_slept:
749         spin_lock(&dq_list_lock);
750         spin_lock(&dq_state_lock);
751         if (!sb_has_quota_active(sb, type)) {
752                 spin_unlock(&dq_state_lock);
753                 spin_unlock(&dq_list_lock);
754                 goto out;
755         }
756         spin_unlock(&dq_state_lock);
757
758         dquot = find_dquot(hashent, sb, id, type);
759         if (!dquot) {
760                 if (!empty) {
761                         spin_unlock(&dq_list_lock);
762                         empty = get_empty_dquot(sb, type);
763                         if (!empty)
764                                 schedule();     /* Try to wait for a moment... */
765                         goto we_slept;
766                 }
767                 dquot = empty;
768                 empty = NULL;
769                 dquot->dq_id = id;
770                 /* all dquots go on the inuse_list */
771                 put_inuse(dquot);
772                 /* hash it first so it can be found */
773                 insert_dquot_hash(dquot);
774                 dqstats.lookups++;
775                 spin_unlock(&dq_list_lock);
776         } else {
777                 if (!atomic_read(&dquot->dq_count))
778                         remove_free_dquot(dquot);
779                 atomic_inc(&dquot->dq_count);
780                 dqstats.cache_hits++;
781                 dqstats.lookups++;
782                 spin_unlock(&dq_list_lock);
783         }
784         /* Wait for dq_lock - after this we know that either dquot_release() is
785          * already finished or it will be canceled due to dq_count > 1 test */
786         wait_on_dquot(dquot);
787         /* Read the dquot / allocate space in quota file */
788         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) &&
789             sb->dq_op->acquire_dquot(dquot) < 0) {
790                 dqput(dquot);
791                 dquot = NULL;
792                 goto out;
793         }
794 #ifdef __DQUOT_PARANOIA
795         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
796 #endif
797 out:
798         if (empty)
799                 do_destroy_dquot(empty);
800
801         return dquot;
802 }
803 EXPORT_SYMBOL(dqget);
804
805 static int dqinit_needed(struct inode *inode, int type)
806 {
807         int cnt;
808
809         if (IS_NOQUOTA(inode))
810                 return 0;
811         if (type != -1)
812                 return !inode->i_dquot[type];
813         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
814                 if (!inode->i_dquot[cnt])
815                         return 1;
816         return 0;
817 }
818
819 /* This routine is guarded by dqonoff_mutex mutex */
820 static void add_dquot_ref(struct super_block *sb, int type)
821 {
822         struct inode *inode, *old_inode = NULL;
823
824         spin_lock(&inode_lock);
825         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
826                 if (!atomic_read(&inode->i_writecount))
827                         continue;
828                 if (!dqinit_needed(inode, type))
829                         continue;
830                 if (inode->i_state & (I_FREEING|I_WILL_FREE))
831                         continue;
832
833                 __iget(inode);
834                 spin_unlock(&inode_lock);
835
836                 iput(old_inode);
837                 sb->dq_op->initialize(inode, type);
838                 /* We hold a reference to 'inode' so it couldn't have been
839                  * removed from s_inodes list while we dropped the inode_lock.
840                  * We cannot iput the inode now as we can be holding the last
841                  * reference and we cannot iput it under inode_lock. So we
842                  * keep the reference and iput it later. */
843                 old_inode = inode;
844                 spin_lock(&inode_lock);
845         }
846         spin_unlock(&inode_lock);
847         iput(old_inode);
848 }
849
850 /*
851  * Return 0 if dqput() won't block.
852  * (note that 1 doesn't necessarily mean blocking)
853  */
854 static inline int dqput_blocks(struct dquot *dquot)
855 {
856         if (atomic_read(&dquot->dq_count) <= 1)
857                 return 1;
858         return 0;
859 }
860
861 /*
862  * Remove references to dquots from inode and add dquot to list for freeing
863  * if we have the last referece to dquot
864  * We can't race with anybody because we hold dqptr_sem for writing...
865  */
866 static int remove_inode_dquot_ref(struct inode *inode, int type,
867                                   struct list_head *tofree_head)
868 {
869         struct dquot *dquot = inode->i_dquot[type];
870
871         inode->i_dquot[type] = NULL;
872         if (dquot) {
873                 if (dqput_blocks(dquot)) {
874 #ifdef __DQUOT_PARANOIA
875                         if (atomic_read(&dquot->dq_count) != 1)
876                                 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
877 #endif
878                         spin_lock(&dq_list_lock);
879                         /* As dquot must have currently users it can't be on
880                          * the free list... */
881                         list_add(&dquot->dq_free, tofree_head);
882                         spin_unlock(&dq_list_lock);
883                         return 1;
884                 }
885                 else
886                         dqput(dquot);   /* We have guaranteed we won't block */
887         }
888         return 0;
889 }
890
891 /*
892  * Free list of dquots
893  * Dquots are removed from inodes and no new references can be got so we are
894  * the only ones holding reference
895  */
896 static void put_dquot_list(struct list_head *tofree_head)
897 {
898         struct list_head *act_head;
899         struct dquot *dquot;
900
901         act_head = tofree_head->next;
902         while (act_head != tofree_head) {
903                 dquot = list_entry(act_head, struct dquot, dq_free);
904                 act_head = act_head->next;
905                 /* Remove dquot from the list so we won't have problems... */
906                 list_del_init(&dquot->dq_free);
907                 dqput(dquot);
908         }
909 }
910
911 static void remove_dquot_ref(struct super_block *sb, int type,
912                 struct list_head *tofree_head)
913 {
914         struct inode *inode;
915
916         spin_lock(&inode_lock);
917         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
918                 if (!IS_NOQUOTA(inode))
919                         remove_inode_dquot_ref(inode, type, tofree_head);
920         }
921         spin_unlock(&inode_lock);
922 }
923
924 /* Gather all references from inodes and drop them */
925 static void drop_dquot_ref(struct super_block *sb, int type)
926 {
927         LIST_HEAD(tofree_head);
928
929         if (sb->dq_op) {
930                 down_write(&sb_dqopt(sb)->dqptr_sem);
931                 remove_dquot_ref(sb, type, &tofree_head);
932                 up_write(&sb_dqopt(sb)->dqptr_sem);
933                 put_dquot_list(&tofree_head);
934         }
935 }
936
937 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
938 {
939         dquot->dq_dqb.dqb_curinodes += number;
940 }
941
942 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
943 {
944         dquot->dq_dqb.dqb_curspace += number;
945 }
946
947 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
948 {
949         dquot->dq_dqb.dqb_rsvspace += number;
950 }
951
952 /*
953  * Claim reserved quota space
954  */
955 static void dquot_claim_reserved_space(struct dquot *dquot,
956                                                 qsize_t number)
957 {
958         WARN_ON(dquot->dq_dqb.dqb_rsvspace < number);
959         dquot->dq_dqb.dqb_curspace += number;
960         dquot->dq_dqb.dqb_rsvspace -= number;
961 }
962
963 static inline
964 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
965 {
966         dquot->dq_dqb.dqb_rsvspace -= number;
967 }
968
969 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
970 {
971         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
972             dquot->dq_dqb.dqb_curinodes >= number)
973                 dquot->dq_dqb.dqb_curinodes -= number;
974         else
975                 dquot->dq_dqb.dqb_curinodes = 0;
976         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
977                 dquot->dq_dqb.dqb_itime = (time_t) 0;
978         clear_bit(DQ_INODES_B, &dquot->dq_flags);
979 }
980
981 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
982 {
983         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
984             dquot->dq_dqb.dqb_curspace >= number)
985                 dquot->dq_dqb.dqb_curspace -= number;
986         else
987                 dquot->dq_dqb.dqb_curspace = 0;
988         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
989                 dquot->dq_dqb.dqb_btime = (time_t) 0;
990         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
991 }
992
993 static int warning_issued(struct dquot *dquot, const int warntype)
994 {
995         int flag = (warntype == QUOTA_NL_BHARDWARN ||
996                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
997                 ((warntype == QUOTA_NL_IHARDWARN ||
998                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
999
1000         if (!flag)
1001                 return 0;
1002         return test_and_set_bit(flag, &dquot->dq_flags);
1003 }
1004
1005 #ifdef CONFIG_PRINT_QUOTA_WARNING
1006 static int flag_print_warnings = 1;
1007
1008 static int need_print_warning(struct dquot *dquot)
1009 {
1010         if (!flag_print_warnings)
1011                 return 0;
1012
1013         switch (dquot->dq_type) {
1014                 case USRQUOTA:
1015                         return current_fsuid() == dquot->dq_id;
1016                 case GRPQUOTA:
1017                         return in_group_p(dquot->dq_id);
1018         }
1019         return 0;
1020 }
1021
1022 /* Print warning to user which exceeded quota */
1023 static void print_warning(struct dquot *dquot, const int warntype)
1024 {
1025         char *msg = NULL;
1026         struct tty_struct *tty;
1027
1028         if (warntype == QUOTA_NL_IHARDBELOW ||
1029             warntype == QUOTA_NL_ISOFTBELOW ||
1030             warntype == QUOTA_NL_BHARDBELOW ||
1031             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
1032                 return;
1033
1034         tty = get_current_tty();
1035         if (!tty)
1036                 return;
1037         tty_write_message(tty, dquot->dq_sb->s_id);
1038         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1039                 tty_write_message(tty, ": warning, ");
1040         else
1041                 tty_write_message(tty, ": write failed, ");
1042         tty_write_message(tty, quotatypes[dquot->dq_type]);
1043         switch (warntype) {
1044                 case QUOTA_NL_IHARDWARN:
1045                         msg = " file limit reached.\r\n";
1046                         break;
1047                 case QUOTA_NL_ISOFTLONGWARN:
1048                         msg = " file quota exceeded too long.\r\n";
1049                         break;
1050                 case QUOTA_NL_ISOFTWARN:
1051                         msg = " file quota exceeded.\r\n";
1052                         break;
1053                 case QUOTA_NL_BHARDWARN:
1054                         msg = " block limit reached.\r\n";
1055                         break;
1056                 case QUOTA_NL_BSOFTLONGWARN:
1057                         msg = " block quota exceeded too long.\r\n";
1058                         break;
1059                 case QUOTA_NL_BSOFTWARN:
1060                         msg = " block quota exceeded.\r\n";
1061                         break;
1062         }
1063         tty_write_message(tty, msg);
1064         tty_kref_put(tty);
1065 }
1066 #endif
1067
1068 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1069
1070 /* Netlink family structure for quota */
1071 static struct genl_family quota_genl_family = {
1072         .id = GENL_ID_GENERATE,
1073         .hdrsize = 0,
1074         .name = "VFS_DQUOT",
1075         .version = 1,
1076         .maxattr = QUOTA_NL_A_MAX,
1077 };
1078
1079 /* Send warning to userspace about user which exceeded quota */
1080 static void send_warning(const struct dquot *dquot, const char warntype)
1081 {
1082         static atomic_t seq;
1083         struct sk_buff *skb;
1084         void *msg_head;
1085         int ret;
1086         int msg_size = 4 * nla_total_size(sizeof(u32)) +
1087                        2 * nla_total_size(sizeof(u64));
1088
1089         /* We have to allocate using GFP_NOFS as we are called from a
1090          * filesystem performing write and thus further recursion into
1091          * the fs to free some data could cause deadlocks. */
1092         skb = genlmsg_new(msg_size, GFP_NOFS);
1093         if (!skb) {
1094                 printk(KERN_ERR
1095                   "VFS: Not enough memory to send quota warning.\n");
1096                 return;
1097         }
1098         msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
1099                         &quota_genl_family, 0, QUOTA_NL_C_WARNING);
1100         if (!msg_head) {
1101                 printk(KERN_ERR
1102                   "VFS: Cannot store netlink header in quota warning.\n");
1103                 goto err_out;
1104         }
1105         ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type);
1106         if (ret)
1107                 goto attr_err_out;
1108         ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id);
1109         if (ret)
1110                 goto attr_err_out;
1111         ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
1112         if (ret)
1113                 goto attr_err_out;
1114         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR,
1115                 MAJOR(dquot->dq_sb->s_dev));
1116         if (ret)
1117                 goto attr_err_out;
1118         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR,
1119                 MINOR(dquot->dq_sb->s_dev));
1120         if (ret)
1121                 goto attr_err_out;
1122         ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
1123         if (ret)
1124                 goto attr_err_out;
1125         genlmsg_end(skb, msg_head);
1126
1127         genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
1128         return;
1129 attr_err_out:
1130         printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
1131 err_out:
1132         kfree_skb(skb);
1133 }
1134 #endif
1135 /*
1136  * Write warnings to the console and send warning messages over netlink.
1137  *
1138  * Note that this function can sleep.
1139  */
1140 static void flush_warnings(struct dquot *const *dquots, char *warntype)
1141 {
1142         int i;
1143
1144         for (i = 0; i < MAXQUOTAS; i++)
1145                 if (dquots[i] && warntype[i] != QUOTA_NL_NOWARN &&
1146                     !warning_issued(dquots[i], warntype[i])) {
1147 #ifdef CONFIG_PRINT_QUOTA_WARNING
1148                         print_warning(dquots[i], warntype[i]);
1149 #endif
1150 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1151                         send_warning(dquots[i], warntype[i]);
1152 #endif
1153                 }
1154 }
1155
1156 static int ignore_hardlimit(struct dquot *dquot)
1157 {
1158         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1159
1160         return capable(CAP_SYS_RESOURCE) &&
1161                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1162                 !(info->dqi_flags & V1_DQF_RSQUASH));
1163 }
1164
1165 /* needs dq_data_lock */
1166 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
1167 {
1168         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1169
1170         *warntype = QUOTA_NL_NOWARN;
1171         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1172             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1173                 return QUOTA_OK;
1174
1175         if (dquot->dq_dqb.dqb_ihardlimit &&
1176             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1177             !ignore_hardlimit(dquot)) {
1178                 *warntype = QUOTA_NL_IHARDWARN;
1179                 return NO_QUOTA;
1180         }
1181
1182         if (dquot->dq_dqb.dqb_isoftlimit &&
1183             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1184             dquot->dq_dqb.dqb_itime &&
1185             get_seconds() >= dquot->dq_dqb.dqb_itime &&
1186             !ignore_hardlimit(dquot)) {
1187                 *warntype = QUOTA_NL_ISOFTLONGWARN;
1188                 return NO_QUOTA;
1189         }
1190
1191         if (dquot->dq_dqb.dqb_isoftlimit &&
1192             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1193             dquot->dq_dqb.dqb_itime == 0) {
1194                 *warntype = QUOTA_NL_ISOFTWARN;
1195                 dquot->dq_dqb.dqb_itime = get_seconds() +
1196                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1197         }
1198
1199         return QUOTA_OK;
1200 }
1201
1202 /* needs dq_data_lock */
1203 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1204 {
1205         qsize_t tspace;
1206         struct super_block *sb = dquot->dq_sb;
1207
1208         *warntype = QUOTA_NL_NOWARN;
1209         if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
1210             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1211                 return QUOTA_OK;
1212
1213         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1214                 + space;
1215
1216         if (dquot->dq_dqb.dqb_bhardlimit &&
1217             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1218             !ignore_hardlimit(dquot)) {
1219                 if (!prealloc)
1220                         *warntype = QUOTA_NL_BHARDWARN;
1221                 return NO_QUOTA;
1222         }
1223
1224         if (dquot->dq_dqb.dqb_bsoftlimit &&
1225             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1226             dquot->dq_dqb.dqb_btime &&
1227             get_seconds() >= dquot->dq_dqb.dqb_btime &&
1228             !ignore_hardlimit(dquot)) {
1229                 if (!prealloc)
1230                         *warntype = QUOTA_NL_BSOFTLONGWARN;
1231                 return NO_QUOTA;
1232         }
1233
1234         if (dquot->dq_dqb.dqb_bsoftlimit &&
1235             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1236             dquot->dq_dqb.dqb_btime == 0) {
1237                 if (!prealloc) {
1238                         *warntype = QUOTA_NL_BSOFTWARN;
1239                         dquot->dq_dqb.dqb_btime = get_seconds() +
1240                             sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
1241                 }
1242                 else
1243                         /*
1244                          * We don't allow preallocation to exceed softlimit so exceeding will
1245                          * be always printed
1246                          */
1247                         return NO_QUOTA;
1248         }
1249
1250         return QUOTA_OK;
1251 }
1252
1253 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1254 {
1255         qsize_t newinodes;
1256
1257         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1258             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1259             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
1260                 return QUOTA_NL_NOWARN;
1261
1262         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1263         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1264                 return QUOTA_NL_ISOFTBELOW;
1265         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1266             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1267                 return QUOTA_NL_IHARDBELOW;
1268         return QUOTA_NL_NOWARN;
1269 }
1270
1271 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1272 {
1273         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1274             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1275                 return QUOTA_NL_NOWARN;
1276
1277         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1278                 return QUOTA_NL_BSOFTBELOW;
1279         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1280             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1281                 return QUOTA_NL_BHARDBELOW;
1282         return QUOTA_NL_NOWARN;
1283 }
1284 /*
1285  *      Initialize quota pointers in inode
1286  *      We do things in a bit complicated way but by that we avoid calling
1287  *      dqget() and thus filesystem callbacks under dqptr_sem.
1288  */
1289 int dquot_initialize(struct inode *inode, int type)
1290 {
1291         unsigned int id = 0;
1292         int cnt, ret = 0;
1293         struct dquot *got[MAXQUOTAS] = { NULL, NULL };
1294         struct super_block *sb = inode->i_sb;
1295
1296         /* First test before acquiring mutex - solves deadlocks when we
1297          * re-enter the quota code and are already holding the mutex */
1298         if (IS_NOQUOTA(inode))
1299                 return 0;
1300
1301         /* First get references to structures we might need. */
1302         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1303                 if (type != -1 && cnt != type)
1304                         continue;
1305                 switch (cnt) {
1306                 case USRQUOTA:
1307                         id = inode->i_uid;
1308                         break;
1309                 case GRPQUOTA:
1310                         id = inode->i_gid;
1311                         break;
1312                 }
1313                 got[cnt] = dqget(sb, id, cnt);
1314         }
1315
1316         down_write(&sb_dqopt(sb)->dqptr_sem);
1317         /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
1318         if (IS_NOQUOTA(inode))
1319                 goto out_err;
1320         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1321                 if (type != -1 && cnt != type)
1322                         continue;
1323                 /* Avoid races with quotaoff() */
1324                 if (!sb_has_quota_active(sb, cnt))
1325                         continue;
1326                 if (!inode->i_dquot[cnt]) {
1327                         inode->i_dquot[cnt] = got[cnt];
1328                         got[cnt] = NULL;
1329                 }
1330         }
1331 out_err:
1332         up_write(&sb_dqopt(sb)->dqptr_sem);
1333         /* Drop unused references */
1334         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1335                 dqput(got[cnt]);
1336         return ret;
1337 }
1338 EXPORT_SYMBOL(dquot_initialize);
1339
1340 /*
1341  *      Release all quotas referenced by inode
1342  */
1343 int dquot_drop(struct inode *inode)
1344 {
1345         int cnt;
1346         struct dquot *put[MAXQUOTAS];
1347
1348         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1349         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1350                 put[cnt] = inode->i_dquot[cnt];
1351                 inode->i_dquot[cnt] = NULL;
1352         }
1353         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1354
1355         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1356                 dqput(put[cnt]);
1357         return 0;
1358 }
1359 EXPORT_SYMBOL(dquot_drop);
1360
1361 /* Wrapper to remove references to quota structures from inode */
1362 void vfs_dq_drop(struct inode *inode)
1363 {
1364         /* Here we can get arbitrary inode from clear_inode() so we have
1365          * to be careful. OTOH we don't need locking as quota operations
1366          * are allowed to change only at mount time */
1367         if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op
1368             && inode->i_sb->dq_op->drop) {
1369                 int cnt;
1370                 /* Test before calling to rule out calls from proc and such
1371                  * where we are not allowed to block. Note that this is
1372                  * actually reliable test even without the lock - the caller
1373                  * must assure that nobody can come after the DQUOT_DROP and
1374                  * add quota pointers back anyway */
1375                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1376                         if (inode->i_dquot[cnt])
1377                                 break;
1378                 if (cnt < MAXQUOTAS)
1379                         inode->i_sb->dq_op->drop(inode);
1380         }
1381 }
1382 EXPORT_SYMBOL(vfs_dq_drop);
1383
1384 /*
1385  * Following four functions update i_blocks+i_bytes fields and
1386  * quota information (together with appropriate checks)
1387  * NOTE: We absolutely rely on the fact that caller dirties
1388  * the inode (usually macros in quotaops.h care about this) and
1389  * holds a handle for the current transaction so that dquot write and
1390  * inode write go into the same transaction.
1391  */
1392
1393 /*
1394  * This operation can block, but only after everything is updated
1395  */
1396 int __dquot_alloc_space(struct inode *inode, qsize_t number,
1397                         int warn, int reserve)
1398 {
1399         int cnt, ret = QUOTA_OK;
1400         char warntype[MAXQUOTAS];
1401
1402         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1403                 warntype[cnt] = QUOTA_NL_NOWARN;
1404
1405         spin_lock(&dq_data_lock);
1406         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1407                 if (!inode->i_dquot[cnt])
1408                         continue;
1409                 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt)
1410                     == NO_QUOTA) {
1411                         ret = NO_QUOTA;
1412                         goto out_unlock;
1413                 }
1414         }
1415         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1416                 if (!inode->i_dquot[cnt])
1417                         continue;
1418                 if (reserve)
1419                         dquot_resv_space(inode->i_dquot[cnt], number);
1420                 else
1421                         dquot_incr_space(inode->i_dquot[cnt], number);
1422         }
1423         if (!reserve)
1424                 inode_add_bytes(inode, number);
1425 out_unlock:
1426         spin_unlock(&dq_data_lock);
1427         flush_warnings(inode->i_dquot, warntype);
1428         return ret;
1429 }
1430
1431 int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1432 {
1433         int cnt, ret = QUOTA_OK;
1434
1435         /*
1436          * First test before acquiring mutex - solves deadlocks when we
1437          * re-enter the quota code and are already holding the mutex
1438          */
1439         if (IS_NOQUOTA(inode)) {
1440                 inode_add_bytes(inode, number);
1441                 goto out;
1442         }
1443
1444         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1445         if (IS_NOQUOTA(inode)) {
1446                 inode_add_bytes(inode, number);
1447                 goto out_unlock;
1448         }
1449
1450         ret = __dquot_alloc_space(inode, number, warn, 0);
1451         if (ret == NO_QUOTA)
1452                 goto out_unlock;
1453
1454         /* Dirtify all the dquots - this can block when journalling */
1455         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1456                 if (inode->i_dquot[cnt])
1457                         mark_dquot_dirty(inode->i_dquot[cnt]);
1458 out_unlock:
1459         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1460 out:
1461         return ret;
1462 }
1463 EXPORT_SYMBOL(dquot_alloc_space);
1464
1465 int dquot_reserve_space(struct inode *inode, qsize_t number, int warn)
1466 {
1467         int ret = QUOTA_OK;
1468
1469         if (IS_NOQUOTA(inode))
1470                 goto out;
1471
1472         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1473         if (IS_NOQUOTA(inode))
1474                 goto out_unlock;
1475
1476         ret = __dquot_alloc_space(inode, number, warn, 1);
1477 out_unlock:
1478         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1479 out:
1480         return ret;
1481 }
1482 EXPORT_SYMBOL(dquot_reserve_space);
1483
1484 /*
1485  * This operation can block, but only after everything is updated
1486  */
1487 int dquot_alloc_inode(const struct inode *inode, qsize_t number)
1488 {
1489         int cnt, ret = NO_QUOTA;
1490         char warntype[MAXQUOTAS];
1491
1492         /* First test before acquiring mutex - solves deadlocks when we
1493          * re-enter the quota code and are already holding the mutex */
1494         if (IS_NOQUOTA(inode))
1495                 return QUOTA_OK;
1496         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1497                 warntype[cnt] = QUOTA_NL_NOWARN;
1498         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1499         if (IS_NOQUOTA(inode)) {
1500                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1501                 return QUOTA_OK;
1502         }
1503         spin_lock(&dq_data_lock);
1504         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1505                 if (!inode->i_dquot[cnt])
1506                         continue;
1507                 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt)
1508                     == NO_QUOTA)
1509                         goto warn_put_all;
1510         }
1511
1512         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1513                 if (!inode->i_dquot[cnt])
1514                         continue;
1515                 dquot_incr_inodes(inode->i_dquot[cnt], number);
1516         }
1517         ret = QUOTA_OK;
1518 warn_put_all:
1519         spin_unlock(&dq_data_lock);
1520         if (ret == QUOTA_OK)
1521                 /* Dirtify all the dquots - this can block when journalling */
1522                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1523                         if (inode->i_dquot[cnt])
1524                                 mark_dquot_dirty(inode->i_dquot[cnt]);
1525         flush_warnings(inode->i_dquot, warntype);
1526         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1527         return ret;
1528 }
1529 EXPORT_SYMBOL(dquot_alloc_inode);
1530
1531 int dquot_claim_space(struct inode *inode, qsize_t number)
1532 {
1533         int cnt;
1534         int ret = QUOTA_OK;
1535
1536         if (IS_NOQUOTA(inode)) {
1537                 inode_add_bytes(inode, number);
1538                 goto out;
1539         }
1540
1541         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1542         if (IS_NOQUOTA(inode))  {
1543                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1544                 inode_add_bytes(inode, number);
1545                 goto out;
1546         }
1547
1548         spin_lock(&dq_data_lock);
1549         /* Claim reserved quotas to allocated quotas */
1550         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1551                 if (inode->i_dquot[cnt])
1552                         dquot_claim_reserved_space(inode->i_dquot[cnt],
1553                                                         number);
1554         }
1555         /* Update inode bytes */
1556         inode_add_bytes(inode, number);
1557         spin_unlock(&dq_data_lock);
1558         /* Dirtify all the dquots - this can block when journalling */
1559         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1560                 if (inode->i_dquot[cnt])
1561                         mark_dquot_dirty(inode->i_dquot[cnt]);
1562         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1563 out:
1564         return ret;
1565 }
1566 EXPORT_SYMBOL(dquot_claim_space);
1567
1568 /*
1569  * Release reserved quota space
1570  */
1571 void dquot_release_reserved_space(struct inode *inode, qsize_t number)
1572 {
1573         int cnt;
1574
1575         if (IS_NOQUOTA(inode))
1576                 goto out;
1577
1578         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1579         if (IS_NOQUOTA(inode))
1580                 goto out_unlock;
1581
1582         spin_lock(&dq_data_lock);
1583         /* Release reserved dquots */
1584         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1585                 if (inode->i_dquot[cnt])
1586                         dquot_free_reserved_space(inode->i_dquot[cnt], number);
1587         }
1588         spin_unlock(&dq_data_lock);
1589
1590 out_unlock:
1591         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1592 out:
1593         return;
1594 }
1595 EXPORT_SYMBOL(dquot_release_reserved_space);
1596
1597 /*
1598  * This operation can block, but only after everything is updated
1599  */
1600 int dquot_free_space(struct inode *inode, qsize_t number)
1601 {
1602         unsigned int cnt;
1603         char warntype[MAXQUOTAS];
1604
1605         /* First test before acquiring mutex - solves deadlocks when we
1606          * re-enter the quota code and are already holding the mutex */
1607         if (IS_NOQUOTA(inode)) {
1608 out_sub:
1609                 inode_sub_bytes(inode, number);
1610                 return QUOTA_OK;
1611         }
1612
1613         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1614         /* Now recheck reliably when holding dqptr_sem */
1615         if (IS_NOQUOTA(inode)) {
1616                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1617                 goto out_sub;
1618         }
1619         spin_lock(&dq_data_lock);
1620         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1621                 if (!inode->i_dquot[cnt])
1622                         continue;
1623                 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
1624                 dquot_decr_space(inode->i_dquot[cnt], number);
1625         }
1626         inode_sub_bytes(inode, number);
1627         spin_unlock(&dq_data_lock);
1628         /* Dirtify all the dquots - this can block when journalling */
1629         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1630                 if (inode->i_dquot[cnt])
1631                         mark_dquot_dirty(inode->i_dquot[cnt]);
1632         flush_warnings(inode->i_dquot, warntype);
1633         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1634         return QUOTA_OK;
1635 }
1636 EXPORT_SYMBOL(dquot_free_space);
1637
1638 /*
1639  * This operation can block, but only after everything is updated
1640  */
1641 int dquot_free_inode(const struct inode *inode, qsize_t number)
1642 {
1643         unsigned int cnt;
1644         char warntype[MAXQUOTAS];
1645
1646         /* First test before acquiring mutex - solves deadlocks when we
1647          * re-enter the quota code and are already holding the mutex */
1648         if (IS_NOQUOTA(inode))
1649                 return QUOTA_OK;
1650
1651         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1652         /* Now recheck reliably when holding dqptr_sem */
1653         if (IS_NOQUOTA(inode)) {
1654                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1655                 return QUOTA_OK;
1656         }
1657         spin_lock(&dq_data_lock);
1658         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1659                 if (!inode->i_dquot[cnt])
1660                         continue;
1661                 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], number);
1662                 dquot_decr_inodes(inode->i_dquot[cnt], number);
1663         }
1664         spin_unlock(&dq_data_lock);
1665         /* Dirtify all the dquots - this can block when journalling */
1666         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1667                 if (inode->i_dquot[cnt])
1668                         mark_dquot_dirty(inode->i_dquot[cnt]);
1669         flush_warnings(inode->i_dquot, warntype);
1670         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1671         return QUOTA_OK;
1672 }
1673 EXPORT_SYMBOL(dquot_free_inode);
1674
1675 /*
1676  * call back function, get reserved quota space from underlying fs
1677  */
1678 qsize_t dquot_get_reserved_space(struct inode *inode)
1679 {
1680         qsize_t reserved_space = 0;
1681
1682         if (sb_any_quota_active(inode->i_sb) &&
1683             inode->i_sb->dq_op->get_reserved_space)
1684                 reserved_space = inode->i_sb->dq_op->get_reserved_space(inode);
1685         return reserved_space;
1686 }
1687
1688 /*
1689  * Transfer the number of inode and blocks from one diskquota to an other.
1690  *
1691  * This operation can block, but only after everything is updated
1692  * A transaction must be started when entering this function.
1693  */
1694 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1695 {
1696         qsize_t space, cur_space;
1697         qsize_t rsv_space = 0;
1698         struct dquot *transfer_from[MAXQUOTAS];
1699         struct dquot *transfer_to[MAXQUOTAS];
1700         int cnt, ret = QUOTA_OK;
1701         int chuid = iattr->ia_valid & ATTR_UID && inode->i_uid != iattr->ia_uid,
1702             chgid = iattr->ia_valid & ATTR_GID && inode->i_gid != iattr->ia_gid;
1703         char warntype_to[MAXQUOTAS];
1704         char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
1705
1706         /* First test before acquiring mutex - solves deadlocks when we
1707          * re-enter the quota code and are already holding the mutex */
1708         if (IS_NOQUOTA(inode))
1709                 return QUOTA_OK;
1710         /* Initialize the arrays */
1711         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1712                 transfer_from[cnt] = NULL;
1713                 transfer_to[cnt] = NULL;
1714                 warntype_to[cnt] = QUOTA_NL_NOWARN;
1715         }
1716         if (chuid)
1717                 transfer_to[USRQUOTA] = dqget(inode->i_sb, iattr->ia_uid,
1718                                               USRQUOTA);
1719         if (chgid)
1720                 transfer_to[GRPQUOTA] = dqget(inode->i_sb, iattr->ia_gid,
1721                                               GRPQUOTA);
1722
1723         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1724         /* Now recheck reliably when holding dqptr_sem */
1725         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1726                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1727                 goto put_all;
1728         }
1729         spin_lock(&dq_data_lock);
1730         cur_space = inode_get_bytes(inode);
1731         rsv_space = dquot_get_reserved_space(inode);
1732         space = cur_space + rsv_space;
1733         /* Build the transfer_from list and check the limits */
1734         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1735                 if (!transfer_to[cnt])
1736                         continue;
1737                 transfer_from[cnt] = inode->i_dquot[cnt];
1738                 if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) ==
1739                     NO_QUOTA || check_bdq(transfer_to[cnt], space, 0,
1740                     warntype_to + cnt) == NO_QUOTA)
1741                         goto over_quota;
1742         }
1743
1744         /*
1745          * Finally perform the needed transfer from transfer_from to transfer_to
1746          */
1747         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1748                 /*
1749                  * Skip changes for same uid or gid or for turned off quota-type.
1750                  */
1751                 if (!transfer_to[cnt])
1752                         continue;
1753
1754                 /* Due to IO error we might not have transfer_from[] structure */
1755                 if (transfer_from[cnt]) {
1756                         warntype_from_inodes[cnt] =
1757                                 info_idq_free(transfer_from[cnt], 1);
1758                         warntype_from_space[cnt] =
1759                                 info_bdq_free(transfer_from[cnt], space);
1760                         dquot_decr_inodes(transfer_from[cnt], 1);
1761                         dquot_decr_space(transfer_from[cnt], cur_space);
1762                         dquot_free_reserved_space(transfer_from[cnt],
1763                                                   rsv_space);
1764                 }
1765
1766                 dquot_incr_inodes(transfer_to[cnt], 1);
1767                 dquot_incr_space(transfer_to[cnt], cur_space);
1768                 dquot_resv_space(transfer_to[cnt], rsv_space);
1769
1770                 inode->i_dquot[cnt] = transfer_to[cnt];
1771         }
1772         spin_unlock(&dq_data_lock);
1773         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1774
1775         /* Dirtify all the dquots - this can block when journalling */
1776         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1777                 if (transfer_from[cnt])
1778                         mark_dquot_dirty(transfer_from[cnt]);
1779                 if (transfer_to[cnt]) {
1780                         mark_dquot_dirty(transfer_to[cnt]);
1781                         /* The reference we got is transferred to the inode */
1782                         transfer_to[cnt] = NULL;
1783                 }
1784         }
1785 warn_put_all:
1786         flush_warnings(transfer_to, warntype_to);
1787         flush_warnings(transfer_from, warntype_from_inodes);
1788         flush_warnings(transfer_from, warntype_from_space);
1789 put_all:
1790         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1791                 dqput(transfer_from[cnt]);
1792                 dqput(transfer_to[cnt]);
1793         }
1794         return ret;
1795 over_quota:
1796         spin_unlock(&dq_data_lock);
1797         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1798         /* Clear dquot pointers we don't want to dqput() */
1799         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1800                 transfer_from[cnt] = NULL;
1801         ret = NO_QUOTA;
1802         goto warn_put_all;
1803 }
1804 EXPORT_SYMBOL(dquot_transfer);
1805
1806 /* Wrapper for transferring ownership of an inode */
1807 int vfs_dq_transfer(struct inode *inode, struct iattr *iattr)
1808 {
1809         if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) {
1810                 vfs_dq_init(inode);
1811                 if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA)
1812                         return 1;
1813         }
1814         return 0;
1815 }
1816 EXPORT_SYMBOL(vfs_dq_transfer);
1817
1818 /*
1819  * Write info of quota file to disk
1820  */
1821 int dquot_commit_info(struct super_block *sb, int type)
1822 {
1823         int ret;
1824         struct quota_info *dqopt = sb_dqopt(sb);
1825
1826         mutex_lock(&dqopt->dqio_mutex);
1827         ret = dqopt->ops[type]->write_file_info(sb, type);
1828         mutex_unlock(&dqopt->dqio_mutex);
1829         return ret;
1830 }
1831 EXPORT_SYMBOL(dquot_commit_info);
1832
1833 /*
1834  * Definitions of diskquota operations.
1835  */
1836 struct dquot_operations dquot_operations = {
1837         .initialize     = dquot_initialize,
1838         .drop           = dquot_drop,
1839         .alloc_space    = dquot_alloc_space,
1840         .alloc_inode    = dquot_alloc_inode,
1841         .free_space     = dquot_free_space,
1842         .free_inode     = dquot_free_inode,
1843         .transfer       = dquot_transfer,
1844         .write_dquot    = dquot_commit,
1845         .acquire_dquot  = dquot_acquire,
1846         .release_dquot  = dquot_release,
1847         .mark_dirty     = dquot_mark_dquot_dirty,
1848         .write_info     = dquot_commit_info,
1849         .alloc_dquot    = dquot_alloc,
1850         .destroy_dquot  = dquot_destroy,
1851 };
1852
1853 /*
1854  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1855  */
1856 int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags)
1857 {
1858         int cnt, ret = 0;
1859         struct quota_info *dqopt = sb_dqopt(sb);
1860         struct inode *toputinode[MAXQUOTAS];
1861
1862         /* Cannot turn off usage accounting without turning off limits, or
1863          * suspend quotas and simultaneously turn quotas off. */
1864         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1865             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1866             DQUOT_USAGE_ENABLED)))
1867                 return -EINVAL;
1868
1869         /* We need to serialize quota_off() for device */
1870         mutex_lock(&dqopt->dqonoff_mutex);
1871
1872         /*
1873          * Skip everything if there's nothing to do. We have to do this because
1874          * sometimes we are called when fill_super() failed and calling
1875          * sync_fs() in such cases does no good.
1876          */
1877         if (!sb_any_quota_loaded(sb)) {
1878                 mutex_unlock(&dqopt->dqonoff_mutex);
1879                 return 0;
1880         }
1881         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1882                 toputinode[cnt] = NULL;
1883                 if (type != -1 && cnt != type)
1884                         continue;
1885                 if (!sb_has_quota_loaded(sb, cnt))
1886                         continue;
1887
1888                 if (flags & DQUOT_SUSPENDED) {
1889                         spin_lock(&dq_state_lock);
1890                         dqopt->flags |=
1891                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1892                         spin_unlock(&dq_state_lock);
1893                 } else {
1894                         spin_lock(&dq_state_lock);
1895                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
1896                         /* Turning off suspended quotas? */
1897                         if (!sb_has_quota_loaded(sb, cnt) &&
1898                             sb_has_quota_suspended(sb, cnt)) {
1899                                 dqopt->flags &= ~dquot_state_flag(
1900                                                         DQUOT_SUSPENDED, cnt);
1901                                 spin_unlock(&dq_state_lock);
1902                                 iput(dqopt->files[cnt]);
1903                                 dqopt->files[cnt] = NULL;
1904                                 continue;
1905                         }
1906                         spin_unlock(&dq_state_lock);
1907                 }
1908
1909                 /* We still have to keep quota loaded? */
1910                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
1911                         continue;
1912
1913                 /* Note: these are blocking operations */
1914                 drop_dquot_ref(sb, cnt);
1915                 invalidate_dquots(sb, cnt);
1916                 /*
1917                  * Now all dquots should be invalidated, all writes done so we
1918                  * should be only users of the info. No locks needed.
1919                  */
1920                 if (info_dirty(&dqopt->info[cnt]))
1921                         sb->dq_op->write_info(sb, cnt);
1922                 if (dqopt->ops[cnt]->free_file_info)
1923                         dqopt->ops[cnt]->free_file_info(sb, cnt);
1924                 put_quota_format(dqopt->info[cnt].dqi_format);
1925
1926                 toputinode[cnt] = dqopt->files[cnt];
1927                 if (!sb_has_quota_loaded(sb, cnt))
1928                         dqopt->files[cnt] = NULL;
1929                 dqopt->info[cnt].dqi_flags = 0;
1930                 dqopt->info[cnt].dqi_igrace = 0;
1931                 dqopt->info[cnt].dqi_bgrace = 0;
1932                 dqopt->ops[cnt] = NULL;
1933         }
1934         mutex_unlock(&dqopt->dqonoff_mutex);
1935
1936         /* Skip syncing and setting flags if quota files are hidden */
1937         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
1938                 goto put_inodes;
1939
1940         /* Sync the superblock so that buffers with quota data are written to
1941          * disk (and so userspace sees correct data afterwards). */
1942         if (sb->s_op->sync_fs)
1943                 sb->s_op->sync_fs(sb, 1);
1944         sync_blockdev(sb->s_bdev);
1945         /* Now the quota files are just ordinary files and we can set the
1946          * inode flags back. Moreover we discard the pagecache so that
1947          * userspace sees the writes we did bypassing the pagecache. We
1948          * must also discard the blockdev buffers so that we see the
1949          * changes done by userspace on the next quotaon() */
1950         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1951                 if (toputinode[cnt]) {
1952                         mutex_lock(&dqopt->dqonoff_mutex);
1953                         /* If quota was reenabled in the meantime, we have
1954                          * nothing to do */
1955                         if (!sb_has_quota_loaded(sb, cnt)) {
1956                                 mutex_lock_nested(&toputinode[cnt]->i_mutex,
1957                                                   I_MUTEX_QUOTA);
1958                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1959                                   S_NOATIME | S_NOQUOTA);
1960                                 truncate_inode_pages(&toputinode[cnt]->i_data,
1961                                                      0);
1962                                 mutex_unlock(&toputinode[cnt]->i_mutex);
1963                                 mark_inode_dirty(toputinode[cnt]);
1964                         }
1965                         mutex_unlock(&dqopt->dqonoff_mutex);
1966                 }
1967         if (sb->s_bdev)
1968                 invalidate_bdev(sb->s_bdev);
1969 put_inodes:
1970         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1971                 if (toputinode[cnt]) {
1972                         /* On remount RO, we keep the inode pointer so that we
1973                          * can reenable quota on the subsequent remount RW. We
1974                          * have to check 'flags' variable and not use sb_has_
1975                          * function because another quotaon / quotaoff could
1976                          * change global state before we got here. We refuse
1977                          * to suspend quotas when there is pending delete on
1978                          * the quota file... */
1979                         if (!(flags & DQUOT_SUSPENDED))
1980                                 iput(toputinode[cnt]);
1981                         else if (!toputinode[cnt]->i_nlink)
1982                                 ret = -EBUSY;
1983                 }
1984         return ret;
1985 }
1986 EXPORT_SYMBOL(vfs_quota_disable);
1987
1988 int vfs_quota_off(struct super_block *sb, int type, int remount)
1989 {
1990         return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED :
1991                                  (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED));
1992 }
1993 EXPORT_SYMBOL(vfs_quota_off);
1994 /*
1995  *      Turn quotas on on a device
1996  */
1997
1998 /*
1999  * Helper function to turn quotas on when we already have the inode of
2000  * quota file and no quota information is loaded.
2001  */
2002 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2003         unsigned int flags)
2004 {
2005         struct quota_format_type *fmt = find_quota_format(format_id);
2006         struct super_block *sb = inode->i_sb;
2007         struct quota_info *dqopt = sb_dqopt(sb);
2008         int error;
2009         int oldflags = -1;
2010
2011         if (!fmt)
2012                 return -ESRCH;
2013         if (!S_ISREG(inode->i_mode)) {
2014                 error = -EACCES;
2015                 goto out_fmt;
2016         }
2017         if (IS_RDONLY(inode)) {
2018                 error = -EROFS;
2019                 goto out_fmt;
2020         }
2021         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
2022                 error = -EINVAL;
2023                 goto out_fmt;
2024         }
2025         /* Usage always has to be set... */
2026         if (!(flags & DQUOT_USAGE_ENABLED)) {
2027                 error = -EINVAL;
2028                 goto out_fmt;
2029         }
2030
2031         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2032                 /* As we bypass the pagecache we must now flush the inode so
2033                  * that we see all the changes from userspace... */
2034                 write_inode_now(inode, 1);
2035                 /* And now flush the block cache so that kernel sees the
2036                  * changes */
2037                 invalidate_bdev(sb->s_bdev);
2038         }
2039         mutex_lock(&inode->i_mutex);
2040         mutex_lock(&dqopt->dqonoff_mutex);
2041         if (sb_has_quota_loaded(sb, type)) {
2042                 error = -EBUSY;
2043                 goto out_lock;
2044         }
2045
2046         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2047                 /* We don't want quota and atime on quota files (deadlocks
2048                  * possible) Also nobody should write to the file - we use
2049                  * special IO operations which ignore the immutable bit. */
2050                 down_write(&dqopt->dqptr_sem);
2051                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2052                                              S_NOQUOTA);
2053                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2054                 up_write(&dqopt->dqptr_sem);
2055                 sb->dq_op->drop(inode);
2056         }
2057
2058         error = -EIO;
2059         dqopt->files[type] = igrab(inode);
2060         if (!dqopt->files[type])
2061                 goto out_lock;
2062         error = -EINVAL;
2063         if (!fmt->qf_ops->check_quota_file(sb, type))
2064                 goto out_file_init;
2065
2066         dqopt->ops[type] = fmt->qf_ops;
2067         dqopt->info[type].dqi_format = fmt;
2068         dqopt->info[type].dqi_fmt_id = format_id;
2069         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2070         mutex_lock(&dqopt->dqio_mutex);
2071         error = dqopt->ops[type]->read_file_info(sb, type);
2072         if (error < 0) {
2073                 mutex_unlock(&dqopt->dqio_mutex);
2074                 goto out_file_init;
2075         }
2076         mutex_unlock(&dqopt->dqio_mutex);
2077         mutex_unlock(&inode->i_mutex);
2078         spin_lock(&dq_state_lock);
2079         dqopt->flags |= dquot_state_flag(flags, type);
2080         spin_unlock(&dq_state_lock);
2081
2082         add_dquot_ref(sb, type);
2083         mutex_unlock(&dqopt->dqonoff_mutex);
2084
2085         return 0;
2086
2087 out_file_init:
2088         dqopt->files[type] = NULL;
2089         iput(inode);
2090 out_lock:
2091         mutex_unlock(&dqopt->dqonoff_mutex);
2092         if (oldflags != -1) {
2093                 down_write(&dqopt->dqptr_sem);
2094                 /* Set the flags back (in the case of accidental quotaon()
2095                  * on a wrong file we don't want to mess up the flags) */
2096                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2097                 inode->i_flags |= oldflags;
2098                 up_write(&dqopt->dqptr_sem);
2099         }
2100         mutex_unlock(&inode->i_mutex);
2101 out_fmt:
2102         put_quota_format(fmt);
2103
2104         return error; 
2105 }
2106
2107 /* Reenable quotas on remount RW */
2108 static int vfs_quota_on_remount(struct super_block *sb, int type)
2109 {
2110         struct quota_info *dqopt = sb_dqopt(sb);
2111         struct inode *inode;
2112         int ret;
2113         unsigned int flags;
2114
2115         mutex_lock(&dqopt->dqonoff_mutex);
2116         if (!sb_has_quota_suspended(sb, type)) {
2117                 mutex_unlock(&dqopt->dqonoff_mutex);
2118                 return 0;
2119         }
2120         inode = dqopt->files[type];
2121         dqopt->files[type] = NULL;
2122         spin_lock(&dq_state_lock);
2123         flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2124                                                 DQUOT_LIMITS_ENABLED, type);
2125         dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type);
2126         spin_unlock(&dq_state_lock);
2127         mutex_unlock(&dqopt->dqonoff_mutex);
2128
2129         flags = dquot_generic_flag(flags, type);
2130         ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id,
2131                                    flags);
2132         iput(inode);
2133
2134         return ret;
2135 }
2136
2137 int vfs_quota_on_path(struct super_block *sb, int type, int format_id,
2138                       struct path *path)
2139 {
2140         int error = security_quota_on(path->dentry);
2141         if (error)
2142                 return error;
2143         /* Quota file not on the same filesystem? */
2144         if (path->mnt->mnt_sb != sb)
2145                 error = -EXDEV;
2146         else
2147                 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2148                                              format_id, DQUOT_USAGE_ENABLED |
2149                                              DQUOT_LIMITS_ENABLED);
2150         return error;
2151 }
2152 EXPORT_SYMBOL(vfs_quota_on_path);
2153
2154 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name,
2155                  int remount)
2156 {
2157         struct path path;
2158         int error;
2159
2160         if (remount)
2161                 return vfs_quota_on_remount(sb, type);
2162
2163         error = kern_path(name, LOOKUP_FOLLOW, &path);
2164         if (!error) {
2165                 error = vfs_quota_on_path(sb, type, format_id, &path);
2166                 path_put(&path);
2167         }
2168         return error;
2169 }
2170 EXPORT_SYMBOL(vfs_quota_on);
2171
2172 /*
2173  * More powerful function for turning on quotas allowing setting
2174  * of individual quota flags
2175  */
2176 int vfs_quota_enable(struct inode *inode, int type, int format_id,
2177                 unsigned int flags)
2178 {
2179         int ret = 0;
2180         struct super_block *sb = inode->i_sb;
2181         struct quota_info *dqopt = sb_dqopt(sb);
2182
2183         /* Just unsuspend quotas? */
2184         if (flags & DQUOT_SUSPENDED)
2185                 return vfs_quota_on_remount(sb, type);
2186         if (!flags)
2187                 return 0;
2188         /* Just updating flags needed? */
2189         if (sb_has_quota_loaded(sb, type)) {
2190                 mutex_lock(&dqopt->dqonoff_mutex);
2191                 /* Now do a reliable test... */
2192                 if (!sb_has_quota_loaded(sb, type)) {
2193                         mutex_unlock(&dqopt->dqonoff_mutex);
2194                         goto load_quota;
2195                 }
2196                 if (flags & DQUOT_USAGE_ENABLED &&
2197                     sb_has_quota_usage_enabled(sb, type)) {
2198                         ret = -EBUSY;
2199                         goto out_lock;
2200                 }
2201                 if (flags & DQUOT_LIMITS_ENABLED &&
2202                     sb_has_quota_limits_enabled(sb, type)) {
2203                         ret = -EBUSY;
2204                         goto out_lock;
2205                 }
2206                 spin_lock(&dq_state_lock);
2207                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2208                 spin_unlock(&dq_state_lock);
2209 out_lock:
2210                 mutex_unlock(&dqopt->dqonoff_mutex);
2211                 return ret;
2212         }
2213
2214 load_quota:
2215         return vfs_load_quota_inode(inode, type, format_id, flags);
2216 }
2217 EXPORT_SYMBOL(vfs_quota_enable);
2218
2219 /*
2220  * This function is used when filesystem needs to initialize quotas
2221  * during mount time.
2222  */
2223 int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
2224                 int format_id, int type)
2225 {
2226         struct dentry *dentry;
2227         int error;
2228
2229         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2230         if (IS_ERR(dentry))
2231                 return PTR_ERR(dentry);
2232
2233         if (!dentry->d_inode) {
2234                 error = -ENOENT;
2235                 goto out;
2236         }
2237
2238         error = security_quota_on(dentry);
2239         if (!error)
2240                 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2241                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2242
2243 out:
2244         dput(dentry);
2245         return error;
2246 }
2247 EXPORT_SYMBOL(vfs_quota_on_mount);
2248
2249 /* Wrapper to turn on quotas when remounting rw */
2250 int vfs_dq_quota_on_remount(struct super_block *sb)
2251 {
2252         int cnt;
2253         int ret = 0, err;
2254
2255         if (!sb->s_qcop || !sb->s_qcop->quota_on)
2256                 return -ENOSYS;
2257         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2258                 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1);
2259                 if (err < 0 && !ret)
2260                         ret = err;
2261         }
2262         return ret;
2263 }
2264 EXPORT_SYMBOL(vfs_dq_quota_on_remount);
2265
2266 static inline qsize_t qbtos(qsize_t blocks)
2267 {
2268         return blocks << QIF_DQBLKSIZE_BITS;
2269 }
2270
2271 static inline qsize_t stoqb(qsize_t space)
2272 {
2273         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2274 }
2275
2276 /* Generic routine for getting common part of quota structure */
2277 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
2278 {
2279         struct mem_dqblk *dm = &dquot->dq_dqb;
2280
2281         spin_lock(&dq_data_lock);
2282         di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit);
2283         di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit);
2284         di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace;
2285         di->dqb_ihardlimit = dm->dqb_ihardlimit;
2286         di->dqb_isoftlimit = dm->dqb_isoftlimit;
2287         di->dqb_curinodes = dm->dqb_curinodes;
2288         di->dqb_btime = dm->dqb_btime;
2289         di->dqb_itime = dm->dqb_itime;
2290         di->dqb_valid = QIF_ALL;
2291         spin_unlock(&dq_data_lock);
2292 }
2293
2294 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id,
2295                   struct if_dqblk *di)
2296 {
2297         struct dquot *dquot;
2298
2299         dquot = dqget(sb, id, type);
2300         if (!dquot)
2301                 return -ESRCH;
2302         do_get_dqblk(dquot, di);
2303         dqput(dquot);
2304
2305         return 0;
2306 }
2307 EXPORT_SYMBOL(vfs_get_dqblk);
2308
2309 /* Generic routine for setting common part of quota structure */
2310 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
2311 {
2312         struct mem_dqblk *dm = &dquot->dq_dqb;
2313         int check_blim = 0, check_ilim = 0;
2314         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2315
2316         if ((di->dqb_valid & QIF_BLIMITS &&
2317              (di->dqb_bhardlimit > dqi->dqi_maxblimit ||
2318               di->dqb_bsoftlimit > dqi->dqi_maxblimit)) ||
2319             (di->dqb_valid & QIF_ILIMITS &&
2320              (di->dqb_ihardlimit > dqi->dqi_maxilimit ||
2321               di->dqb_isoftlimit > dqi->dqi_maxilimit)))
2322                 return -ERANGE;
2323
2324         spin_lock(&dq_data_lock);
2325         if (di->dqb_valid & QIF_SPACE) {
2326                 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace;
2327                 check_blim = 1;
2328                 __set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2329         }
2330         if (di->dqb_valid & QIF_BLIMITS) {
2331                 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit);
2332                 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit);
2333                 check_blim = 1;
2334                 __set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2335         }
2336         if (di->dqb_valid & QIF_INODES) {
2337                 dm->dqb_curinodes = di->dqb_curinodes;
2338                 check_ilim = 1;
2339                 __set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2340         }
2341         if (di->dqb_valid & QIF_ILIMITS) {
2342                 dm->dqb_isoftlimit = di->dqb_isoftlimit;
2343                 dm->dqb_ihardlimit = di->dqb_ihardlimit;
2344                 check_ilim = 1;
2345                 __set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2346         }
2347         if (di->dqb_valid & QIF_BTIME) {
2348                 dm->dqb_btime = di->dqb_btime;
2349                 check_blim = 1;
2350                 __set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2351         }
2352         if (di->dqb_valid & QIF_ITIME) {
2353                 dm->dqb_itime = di->dqb_itime;
2354                 check_ilim = 1;
2355                 __set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2356         }
2357
2358         if (check_blim) {
2359                 if (!dm->dqb_bsoftlimit ||
2360                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2361                         dm->dqb_btime = 0;
2362                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2363                 } else if (!(di->dqb_valid & QIF_BTIME))
2364                         /* Set grace only if user hasn't provided his own... */
2365                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2366         }
2367         if (check_ilim) {
2368                 if (!dm->dqb_isoftlimit ||
2369                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2370                         dm->dqb_itime = 0;
2371                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2372                 } else if (!(di->dqb_valid & QIF_ITIME))
2373                         /* Set grace only if user hasn't provided his own... */
2374                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2375         }
2376         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2377             dm->dqb_isoftlimit)
2378                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2379         else
2380                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2381         spin_unlock(&dq_data_lock);
2382         mark_dquot_dirty(dquot);
2383
2384         return 0;
2385 }
2386
2387 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id,
2388                   struct if_dqblk *di)
2389 {
2390         struct dquot *dquot;
2391         int rc;
2392
2393         dquot = dqget(sb, id, type);
2394         if (!dquot) {
2395                 rc = -ESRCH;
2396                 goto out;
2397         }
2398         rc = do_set_dqblk(dquot, di);
2399         dqput(dquot);
2400 out:
2401         return rc;
2402 }
2403 EXPORT_SYMBOL(vfs_set_dqblk);
2404
2405 /* Generic routine for getting common part of quota file information */
2406 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2407 {
2408         struct mem_dqinfo *mi;
2409   
2410         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2411         if (!sb_has_quota_active(sb, type)) {
2412                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2413                 return -ESRCH;
2414         }
2415         mi = sb_dqopt(sb)->info + type;
2416         spin_lock(&dq_data_lock);
2417         ii->dqi_bgrace = mi->dqi_bgrace;
2418         ii->dqi_igrace = mi->dqi_igrace;
2419         ii->dqi_flags = mi->dqi_flags & DQF_MASK;
2420         ii->dqi_valid = IIF_ALL;
2421         spin_unlock(&dq_data_lock);
2422         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2423         return 0;
2424 }
2425 EXPORT_SYMBOL(vfs_get_dqinfo);
2426
2427 /* Generic routine for setting common part of quota file information */
2428 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2429 {
2430         struct mem_dqinfo *mi;
2431         int err = 0;
2432
2433         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2434         if (!sb_has_quota_active(sb, type)) {
2435                 err = -ESRCH;
2436                 goto out;
2437         }
2438         mi = sb_dqopt(sb)->info + type;
2439         spin_lock(&dq_data_lock);
2440         if (ii->dqi_valid & IIF_BGRACE)
2441                 mi->dqi_bgrace = ii->dqi_bgrace;
2442         if (ii->dqi_valid & IIF_IGRACE)
2443                 mi->dqi_igrace = ii->dqi_igrace;
2444         if (ii->dqi_valid & IIF_FLAGS)
2445                 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) |
2446                                 (ii->dqi_flags & DQF_MASK);
2447         spin_unlock(&dq_data_lock);
2448         mark_info_dirty(sb, type);
2449         /* Force write to disk */
2450         sb->dq_op->write_info(sb, type);
2451 out:
2452         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2453         return err;
2454 }
2455 EXPORT_SYMBOL(vfs_set_dqinfo);
2456
2457 struct quotactl_ops vfs_quotactl_ops = {
2458         .quota_on       = vfs_quota_on,
2459         .quota_off      = vfs_quota_off,
2460         .quota_sync     = vfs_quota_sync,
2461         .get_info       = vfs_get_dqinfo,
2462         .set_info       = vfs_set_dqinfo,
2463         .get_dqblk      = vfs_get_dqblk,
2464         .set_dqblk      = vfs_set_dqblk
2465 };
2466
2467 static ctl_table fs_dqstats_table[] = {
2468         {
2469                 .ctl_name       = FS_DQ_LOOKUPS,
2470                 .procname       = "lookups",
2471                 .data           = &dqstats.lookups,
2472                 .maxlen         = sizeof(int),
2473                 .mode           = 0444,
2474                 .proc_handler   = &proc_dointvec,
2475         },
2476         {
2477                 .ctl_name       = FS_DQ_DROPS,
2478                 .procname       = "drops",
2479                 .data           = &dqstats.drops,
2480                 .maxlen         = sizeof(int),
2481                 .mode           = 0444,
2482                 .proc_handler   = &proc_dointvec,
2483         },
2484         {
2485                 .ctl_name       = FS_DQ_READS,
2486                 .procname       = "reads",
2487                 .data           = &dqstats.reads,
2488                 .maxlen         = sizeof(int),
2489                 .mode           = 0444,
2490                 .proc_handler   = &proc_dointvec,
2491         },
2492         {
2493                 .ctl_name       = FS_DQ_WRITES,
2494                 .procname       = "writes",
2495                 .data           = &dqstats.writes,
2496                 .maxlen         = sizeof(int),
2497                 .mode           = 0444,
2498                 .proc_handler   = &proc_dointvec,
2499         },
2500         {
2501                 .ctl_name       = FS_DQ_CACHE_HITS,
2502                 .procname       = "cache_hits",
2503                 .data           = &dqstats.cache_hits,
2504                 .maxlen         = sizeof(int),
2505                 .mode           = 0444,
2506                 .proc_handler   = &proc_dointvec,
2507         },
2508         {
2509                 .ctl_name       = FS_DQ_ALLOCATED,
2510                 .procname       = "allocated_dquots",
2511                 .data           = &dqstats.allocated_dquots,
2512                 .maxlen         = sizeof(int),
2513                 .mode           = 0444,
2514                 .proc_handler   = &proc_dointvec,
2515         },
2516         {
2517                 .ctl_name       = FS_DQ_FREE,
2518                 .procname       = "free_dquots",
2519                 .data           = &dqstats.free_dquots,
2520                 .maxlen         = sizeof(int),
2521                 .mode           = 0444,
2522                 .proc_handler   = &proc_dointvec,
2523         },
2524         {
2525                 .ctl_name       = FS_DQ_SYNCS,
2526                 .procname       = "syncs",
2527                 .data           = &dqstats.syncs,
2528                 .maxlen         = sizeof(int),
2529                 .mode           = 0444,
2530                 .proc_handler   = &proc_dointvec,
2531         },
2532 #ifdef CONFIG_PRINT_QUOTA_WARNING
2533         {
2534                 .ctl_name       = FS_DQ_WARNINGS,
2535                 .procname       = "warnings",
2536                 .data           = &flag_print_warnings,
2537                 .maxlen         = sizeof(int),
2538                 .mode           = 0644,
2539                 .proc_handler   = &proc_dointvec,
2540         },
2541 #endif
2542         { .ctl_name = 0 },
2543 };
2544
2545 static ctl_table fs_table[] = {
2546         {
2547                 .ctl_name       = FS_DQSTATS,
2548                 .procname       = "quota",
2549                 .mode           = 0555,
2550                 .child          = fs_dqstats_table,
2551         },
2552         { .ctl_name = 0 },
2553 };
2554
2555 static ctl_table sys_table[] = {
2556         {
2557                 .ctl_name       = CTL_FS,
2558                 .procname       = "fs",
2559                 .mode           = 0555,
2560                 .child          = fs_table,
2561         },
2562         { .ctl_name = 0 },
2563 };
2564
2565 static int __init dquot_init(void)
2566 {
2567         int i;
2568         unsigned long nr_hash, order;
2569
2570         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2571
2572         register_sysctl_table(sys_table);
2573
2574         dquot_cachep = kmem_cache_create("dquot",
2575                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2576                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2577                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2578                         NULL);
2579
2580         order = 0;
2581         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2582         if (!dquot_hash)
2583                 panic("Cannot create dquot hash table");
2584
2585         /* Find power-of-two hlist_heads which can fit into allocation */
2586         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2587         dq_hash_bits = 0;
2588         do {
2589                 dq_hash_bits++;
2590         } while (nr_hash >> dq_hash_bits);
2591         dq_hash_bits--;
2592
2593         nr_hash = 1UL << dq_hash_bits;
2594         dq_hash_mask = nr_hash - 1;
2595         for (i = 0; i < nr_hash; i++)
2596                 INIT_HLIST_HEAD(dquot_hash + i);
2597
2598         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2599                         nr_hash, order, (PAGE_SIZE << order));
2600
2601         register_shrinker(&dqcache_shrinker);
2602
2603 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
2604         if (genl_register_family(&quota_genl_family) != 0)
2605                 printk(KERN_ERR
2606                        "VFS: Failed to create quota netlink interface.\n");
2607 #endif
2608
2609         return 0;
2610 }
2611 module_init(dquot_init);