sysctl: Drop & in front of every proc_handler.
[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 (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW))
827                         continue;
828                 if (!atomic_read(&inode->i_writecount))
829                         continue;
830                 if (!dqinit_needed(inode, type))
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                 /*
919                  *  We have to scan also I_NEW inodes because they can already
920                  *  have quota pointer initialized. Luckily, we need to touch
921                  *  only quota pointers and these have separate locking
922                  *  (dqptr_sem).
923                  */
924                 if (!IS_NOQUOTA(inode))
925                         remove_inode_dquot_ref(inode, type, tofree_head);
926         }
927         spin_unlock(&inode_lock);
928 }
929
930 /* Gather all references from inodes and drop them */
931 static void drop_dquot_ref(struct super_block *sb, int type)
932 {
933         LIST_HEAD(tofree_head);
934
935         if (sb->dq_op) {
936                 down_write(&sb_dqopt(sb)->dqptr_sem);
937                 remove_dquot_ref(sb, type, &tofree_head);
938                 up_write(&sb_dqopt(sb)->dqptr_sem);
939                 put_dquot_list(&tofree_head);
940         }
941 }
942
943 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
944 {
945         dquot->dq_dqb.dqb_curinodes += number;
946 }
947
948 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
949 {
950         dquot->dq_dqb.dqb_curspace += number;
951 }
952
953 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
954 {
955         dquot->dq_dqb.dqb_rsvspace += number;
956 }
957
958 /*
959  * Claim reserved quota space
960  */
961 static void dquot_claim_reserved_space(struct dquot *dquot,
962                                                 qsize_t number)
963 {
964         WARN_ON(dquot->dq_dqb.dqb_rsvspace < number);
965         dquot->dq_dqb.dqb_curspace += number;
966         dquot->dq_dqb.dqb_rsvspace -= number;
967 }
968
969 static inline
970 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
971 {
972         dquot->dq_dqb.dqb_rsvspace -= number;
973 }
974
975 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
976 {
977         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
978             dquot->dq_dqb.dqb_curinodes >= number)
979                 dquot->dq_dqb.dqb_curinodes -= number;
980         else
981                 dquot->dq_dqb.dqb_curinodes = 0;
982         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
983                 dquot->dq_dqb.dqb_itime = (time_t) 0;
984         clear_bit(DQ_INODES_B, &dquot->dq_flags);
985 }
986
987 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
988 {
989         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
990             dquot->dq_dqb.dqb_curspace >= number)
991                 dquot->dq_dqb.dqb_curspace -= number;
992         else
993                 dquot->dq_dqb.dqb_curspace = 0;
994         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
995                 dquot->dq_dqb.dqb_btime = (time_t) 0;
996         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
997 }
998
999 static int warning_issued(struct dquot *dquot, const int warntype)
1000 {
1001         int flag = (warntype == QUOTA_NL_BHARDWARN ||
1002                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1003                 ((warntype == QUOTA_NL_IHARDWARN ||
1004                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1005
1006         if (!flag)
1007                 return 0;
1008         return test_and_set_bit(flag, &dquot->dq_flags);
1009 }
1010
1011 #ifdef CONFIG_PRINT_QUOTA_WARNING
1012 static int flag_print_warnings = 1;
1013
1014 static int need_print_warning(struct dquot *dquot)
1015 {
1016         if (!flag_print_warnings)
1017                 return 0;
1018
1019         switch (dquot->dq_type) {
1020                 case USRQUOTA:
1021                         return current_fsuid() == dquot->dq_id;
1022                 case GRPQUOTA:
1023                         return in_group_p(dquot->dq_id);
1024         }
1025         return 0;
1026 }
1027
1028 /* Print warning to user which exceeded quota */
1029 static void print_warning(struct dquot *dquot, const int warntype)
1030 {
1031         char *msg = NULL;
1032         struct tty_struct *tty;
1033
1034         if (warntype == QUOTA_NL_IHARDBELOW ||
1035             warntype == QUOTA_NL_ISOFTBELOW ||
1036             warntype == QUOTA_NL_BHARDBELOW ||
1037             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
1038                 return;
1039
1040         tty = get_current_tty();
1041         if (!tty)
1042                 return;
1043         tty_write_message(tty, dquot->dq_sb->s_id);
1044         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1045                 tty_write_message(tty, ": warning, ");
1046         else
1047                 tty_write_message(tty, ": write failed, ");
1048         tty_write_message(tty, quotatypes[dquot->dq_type]);
1049         switch (warntype) {
1050                 case QUOTA_NL_IHARDWARN:
1051                         msg = " file limit reached.\r\n";
1052                         break;
1053                 case QUOTA_NL_ISOFTLONGWARN:
1054                         msg = " file quota exceeded too long.\r\n";
1055                         break;
1056                 case QUOTA_NL_ISOFTWARN:
1057                         msg = " file quota exceeded.\r\n";
1058                         break;
1059                 case QUOTA_NL_BHARDWARN:
1060                         msg = " block limit reached.\r\n";
1061                         break;
1062                 case QUOTA_NL_BSOFTLONGWARN:
1063                         msg = " block quota exceeded too long.\r\n";
1064                         break;
1065                 case QUOTA_NL_BSOFTWARN:
1066                         msg = " block quota exceeded.\r\n";
1067                         break;
1068         }
1069         tty_write_message(tty, msg);
1070         tty_kref_put(tty);
1071 }
1072 #endif
1073
1074 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1075
1076 /* Netlink family structure for quota */
1077 static struct genl_family quota_genl_family = {
1078         .id = GENL_ID_GENERATE,
1079         .hdrsize = 0,
1080         .name = "VFS_DQUOT",
1081         .version = 1,
1082         .maxattr = QUOTA_NL_A_MAX,
1083 };
1084
1085 /* Send warning to userspace about user which exceeded quota */
1086 static void send_warning(const struct dquot *dquot, const char warntype)
1087 {
1088         static atomic_t seq;
1089         struct sk_buff *skb;
1090         void *msg_head;
1091         int ret;
1092         int msg_size = 4 * nla_total_size(sizeof(u32)) +
1093                        2 * nla_total_size(sizeof(u64));
1094
1095         /* We have to allocate using GFP_NOFS as we are called from a
1096          * filesystem performing write and thus further recursion into
1097          * the fs to free some data could cause deadlocks. */
1098         skb = genlmsg_new(msg_size, GFP_NOFS);
1099         if (!skb) {
1100                 printk(KERN_ERR
1101                   "VFS: Not enough memory to send quota warning.\n");
1102                 return;
1103         }
1104         msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
1105                         &quota_genl_family, 0, QUOTA_NL_C_WARNING);
1106         if (!msg_head) {
1107                 printk(KERN_ERR
1108                   "VFS: Cannot store netlink header in quota warning.\n");
1109                 goto err_out;
1110         }
1111         ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type);
1112         if (ret)
1113                 goto attr_err_out;
1114         ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id);
1115         if (ret)
1116                 goto attr_err_out;
1117         ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
1118         if (ret)
1119                 goto attr_err_out;
1120         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR,
1121                 MAJOR(dquot->dq_sb->s_dev));
1122         if (ret)
1123                 goto attr_err_out;
1124         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR,
1125                 MINOR(dquot->dq_sb->s_dev));
1126         if (ret)
1127                 goto attr_err_out;
1128         ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
1129         if (ret)
1130                 goto attr_err_out;
1131         genlmsg_end(skb, msg_head);
1132
1133         genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
1134         return;
1135 attr_err_out:
1136         printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
1137 err_out:
1138         kfree_skb(skb);
1139 }
1140 #endif
1141 /*
1142  * Write warnings to the console and send warning messages over netlink.
1143  *
1144  * Note that this function can sleep.
1145  */
1146 static void flush_warnings(struct dquot *const *dquots, char *warntype)
1147 {
1148         int i;
1149
1150         for (i = 0; i < MAXQUOTAS; i++)
1151                 if (dquots[i] && warntype[i] != QUOTA_NL_NOWARN &&
1152                     !warning_issued(dquots[i], warntype[i])) {
1153 #ifdef CONFIG_PRINT_QUOTA_WARNING
1154                         print_warning(dquots[i], warntype[i]);
1155 #endif
1156 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1157                         send_warning(dquots[i], warntype[i]);
1158 #endif
1159                 }
1160 }
1161
1162 static int ignore_hardlimit(struct dquot *dquot)
1163 {
1164         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1165
1166         return capable(CAP_SYS_RESOURCE) &&
1167                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1168                 !(info->dqi_flags & V1_DQF_RSQUASH));
1169 }
1170
1171 /* needs dq_data_lock */
1172 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
1173 {
1174         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1175
1176         *warntype = QUOTA_NL_NOWARN;
1177         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1178             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1179                 return QUOTA_OK;
1180
1181         if (dquot->dq_dqb.dqb_ihardlimit &&
1182             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1183             !ignore_hardlimit(dquot)) {
1184                 *warntype = QUOTA_NL_IHARDWARN;
1185                 return NO_QUOTA;
1186         }
1187
1188         if (dquot->dq_dqb.dqb_isoftlimit &&
1189             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1190             dquot->dq_dqb.dqb_itime &&
1191             get_seconds() >= dquot->dq_dqb.dqb_itime &&
1192             !ignore_hardlimit(dquot)) {
1193                 *warntype = QUOTA_NL_ISOFTLONGWARN;
1194                 return NO_QUOTA;
1195         }
1196
1197         if (dquot->dq_dqb.dqb_isoftlimit &&
1198             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1199             dquot->dq_dqb.dqb_itime == 0) {
1200                 *warntype = QUOTA_NL_ISOFTWARN;
1201                 dquot->dq_dqb.dqb_itime = get_seconds() +
1202                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1203         }
1204
1205         return QUOTA_OK;
1206 }
1207
1208 /* needs dq_data_lock */
1209 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1210 {
1211         qsize_t tspace;
1212         struct super_block *sb = dquot->dq_sb;
1213
1214         *warntype = QUOTA_NL_NOWARN;
1215         if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
1216             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1217                 return QUOTA_OK;
1218
1219         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1220                 + space;
1221
1222         if (dquot->dq_dqb.dqb_bhardlimit &&
1223             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1224             !ignore_hardlimit(dquot)) {
1225                 if (!prealloc)
1226                         *warntype = QUOTA_NL_BHARDWARN;
1227                 return NO_QUOTA;
1228         }
1229
1230         if (dquot->dq_dqb.dqb_bsoftlimit &&
1231             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1232             dquot->dq_dqb.dqb_btime &&
1233             get_seconds() >= dquot->dq_dqb.dqb_btime &&
1234             !ignore_hardlimit(dquot)) {
1235                 if (!prealloc)
1236                         *warntype = QUOTA_NL_BSOFTLONGWARN;
1237                 return NO_QUOTA;
1238         }
1239
1240         if (dquot->dq_dqb.dqb_bsoftlimit &&
1241             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1242             dquot->dq_dqb.dqb_btime == 0) {
1243                 if (!prealloc) {
1244                         *warntype = QUOTA_NL_BSOFTWARN;
1245                         dquot->dq_dqb.dqb_btime = get_seconds() +
1246                             sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
1247                 }
1248                 else
1249                         /*
1250                          * We don't allow preallocation to exceed softlimit so exceeding will
1251                          * be always printed
1252                          */
1253                         return NO_QUOTA;
1254         }
1255
1256         return QUOTA_OK;
1257 }
1258
1259 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1260 {
1261         qsize_t newinodes;
1262
1263         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1264             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1265             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
1266                 return QUOTA_NL_NOWARN;
1267
1268         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1269         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1270                 return QUOTA_NL_ISOFTBELOW;
1271         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1272             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1273                 return QUOTA_NL_IHARDBELOW;
1274         return QUOTA_NL_NOWARN;
1275 }
1276
1277 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1278 {
1279         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1280             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1281                 return QUOTA_NL_NOWARN;
1282
1283         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1284                 return QUOTA_NL_BSOFTBELOW;
1285         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1286             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1287                 return QUOTA_NL_BHARDBELOW;
1288         return QUOTA_NL_NOWARN;
1289 }
1290 /*
1291  *      Initialize quota pointers in inode
1292  *      We do things in a bit complicated way but by that we avoid calling
1293  *      dqget() and thus filesystem callbacks under dqptr_sem.
1294  */
1295 int dquot_initialize(struct inode *inode, int type)
1296 {
1297         unsigned int id = 0;
1298         int cnt, ret = 0;
1299         struct dquot *got[MAXQUOTAS] = { NULL, NULL };
1300         struct super_block *sb = inode->i_sb;
1301
1302         /* First test before acquiring mutex - solves deadlocks when we
1303          * re-enter the quota code and are already holding the mutex */
1304         if (IS_NOQUOTA(inode))
1305                 return 0;
1306
1307         /* First get references to structures we might need. */
1308         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1309                 if (type != -1 && cnt != type)
1310                         continue;
1311                 switch (cnt) {
1312                 case USRQUOTA:
1313                         id = inode->i_uid;
1314                         break;
1315                 case GRPQUOTA:
1316                         id = inode->i_gid;
1317                         break;
1318                 }
1319                 got[cnt] = dqget(sb, id, cnt);
1320         }
1321
1322         down_write(&sb_dqopt(sb)->dqptr_sem);
1323         /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
1324         if (IS_NOQUOTA(inode))
1325                 goto out_err;
1326         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1327                 if (type != -1 && cnt != type)
1328                         continue;
1329                 /* Avoid races with quotaoff() */
1330                 if (!sb_has_quota_active(sb, cnt))
1331                         continue;
1332                 if (!inode->i_dquot[cnt]) {
1333                         inode->i_dquot[cnt] = got[cnt];
1334                         got[cnt] = NULL;
1335                 }
1336         }
1337 out_err:
1338         up_write(&sb_dqopt(sb)->dqptr_sem);
1339         /* Drop unused references */
1340         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1341                 dqput(got[cnt]);
1342         return ret;
1343 }
1344 EXPORT_SYMBOL(dquot_initialize);
1345
1346 /*
1347  *      Release all quotas referenced by inode
1348  */
1349 int dquot_drop(struct inode *inode)
1350 {
1351         int cnt;
1352         struct dquot *put[MAXQUOTAS];
1353
1354         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1355         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1356                 put[cnt] = inode->i_dquot[cnt];
1357                 inode->i_dquot[cnt] = NULL;
1358         }
1359         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1360
1361         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1362                 dqput(put[cnt]);
1363         return 0;
1364 }
1365 EXPORT_SYMBOL(dquot_drop);
1366
1367 /* Wrapper to remove references to quota structures from inode */
1368 void vfs_dq_drop(struct inode *inode)
1369 {
1370         /* Here we can get arbitrary inode from clear_inode() so we have
1371          * to be careful. OTOH we don't need locking as quota operations
1372          * are allowed to change only at mount time */
1373         if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op
1374             && inode->i_sb->dq_op->drop) {
1375                 int cnt;
1376                 /* Test before calling to rule out calls from proc and such
1377                  * where we are not allowed to block. Note that this is
1378                  * actually reliable test even without the lock - the caller
1379                  * must assure that nobody can come after the DQUOT_DROP and
1380                  * add quota pointers back anyway */
1381                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1382                         if (inode->i_dquot[cnt])
1383                                 break;
1384                 if (cnt < MAXQUOTAS)
1385                         inode->i_sb->dq_op->drop(inode);
1386         }
1387 }
1388 EXPORT_SYMBOL(vfs_dq_drop);
1389
1390 /*
1391  * Following four functions update i_blocks+i_bytes fields and
1392  * quota information (together with appropriate checks)
1393  * NOTE: We absolutely rely on the fact that caller dirties
1394  * the inode (usually macros in quotaops.h care about this) and
1395  * holds a handle for the current transaction so that dquot write and
1396  * inode write go into the same transaction.
1397  */
1398
1399 /*
1400  * This operation can block, but only after everything is updated
1401  */
1402 int __dquot_alloc_space(struct inode *inode, qsize_t number,
1403                         int warn, int reserve)
1404 {
1405         int cnt, ret = QUOTA_OK;
1406         char warntype[MAXQUOTAS];
1407
1408         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1409                 warntype[cnt] = QUOTA_NL_NOWARN;
1410
1411         spin_lock(&dq_data_lock);
1412         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1413                 if (!inode->i_dquot[cnt])
1414                         continue;
1415                 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt)
1416                     == NO_QUOTA) {
1417                         ret = NO_QUOTA;
1418                         goto out_unlock;
1419                 }
1420         }
1421         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1422                 if (!inode->i_dquot[cnt])
1423                         continue;
1424                 if (reserve)
1425                         dquot_resv_space(inode->i_dquot[cnt], number);
1426                 else
1427                         dquot_incr_space(inode->i_dquot[cnt], number);
1428         }
1429         if (!reserve)
1430                 inode_add_bytes(inode, number);
1431 out_unlock:
1432         spin_unlock(&dq_data_lock);
1433         flush_warnings(inode->i_dquot, warntype);
1434         return ret;
1435 }
1436
1437 int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1438 {
1439         int cnt, ret = QUOTA_OK;
1440
1441         /*
1442          * First test before acquiring mutex - solves deadlocks when we
1443          * re-enter the quota code and are already holding the mutex
1444          */
1445         if (IS_NOQUOTA(inode)) {
1446                 inode_add_bytes(inode, number);
1447                 goto out;
1448         }
1449
1450         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1451         if (IS_NOQUOTA(inode)) {
1452                 inode_add_bytes(inode, number);
1453                 goto out_unlock;
1454         }
1455
1456         ret = __dquot_alloc_space(inode, number, warn, 0);
1457         if (ret == NO_QUOTA)
1458                 goto out_unlock;
1459
1460         /* Dirtify all the dquots - this can block when journalling */
1461         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1462                 if (inode->i_dquot[cnt])
1463                         mark_dquot_dirty(inode->i_dquot[cnt]);
1464 out_unlock:
1465         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1466 out:
1467         return ret;
1468 }
1469 EXPORT_SYMBOL(dquot_alloc_space);
1470
1471 int dquot_reserve_space(struct inode *inode, qsize_t number, int warn)
1472 {
1473         int ret = QUOTA_OK;
1474
1475         if (IS_NOQUOTA(inode))
1476                 goto out;
1477
1478         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1479         if (IS_NOQUOTA(inode))
1480                 goto out_unlock;
1481
1482         ret = __dquot_alloc_space(inode, number, warn, 1);
1483 out_unlock:
1484         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1485 out:
1486         return ret;
1487 }
1488 EXPORT_SYMBOL(dquot_reserve_space);
1489
1490 /*
1491  * This operation can block, but only after everything is updated
1492  */
1493 int dquot_alloc_inode(const struct inode *inode, qsize_t number)
1494 {
1495         int cnt, ret = NO_QUOTA;
1496         char warntype[MAXQUOTAS];
1497
1498         /* First test before acquiring mutex - solves deadlocks when we
1499          * re-enter the quota code and are already holding the mutex */
1500         if (IS_NOQUOTA(inode))
1501                 return QUOTA_OK;
1502         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1503                 warntype[cnt] = QUOTA_NL_NOWARN;
1504         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1505         if (IS_NOQUOTA(inode)) {
1506                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1507                 return QUOTA_OK;
1508         }
1509         spin_lock(&dq_data_lock);
1510         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1511                 if (!inode->i_dquot[cnt])
1512                         continue;
1513                 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt)
1514                     == NO_QUOTA)
1515                         goto warn_put_all;
1516         }
1517
1518         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1519                 if (!inode->i_dquot[cnt])
1520                         continue;
1521                 dquot_incr_inodes(inode->i_dquot[cnt], number);
1522         }
1523         ret = QUOTA_OK;
1524 warn_put_all:
1525         spin_unlock(&dq_data_lock);
1526         if (ret == QUOTA_OK)
1527                 /* Dirtify all the dquots - this can block when journalling */
1528                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1529                         if (inode->i_dquot[cnt])
1530                                 mark_dquot_dirty(inode->i_dquot[cnt]);
1531         flush_warnings(inode->i_dquot, warntype);
1532         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1533         return ret;
1534 }
1535 EXPORT_SYMBOL(dquot_alloc_inode);
1536
1537 int dquot_claim_space(struct inode *inode, qsize_t number)
1538 {
1539         int cnt;
1540         int ret = QUOTA_OK;
1541
1542         if (IS_NOQUOTA(inode)) {
1543                 inode_add_bytes(inode, number);
1544                 goto out;
1545         }
1546
1547         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1548         if (IS_NOQUOTA(inode))  {
1549                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1550                 inode_add_bytes(inode, number);
1551                 goto out;
1552         }
1553
1554         spin_lock(&dq_data_lock);
1555         /* Claim reserved quotas to allocated quotas */
1556         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1557                 if (inode->i_dquot[cnt])
1558                         dquot_claim_reserved_space(inode->i_dquot[cnt],
1559                                                         number);
1560         }
1561         /* Update inode bytes */
1562         inode_add_bytes(inode, number);
1563         spin_unlock(&dq_data_lock);
1564         /* Dirtify all the dquots - this can block when journalling */
1565         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1566                 if (inode->i_dquot[cnt])
1567                         mark_dquot_dirty(inode->i_dquot[cnt]);
1568         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1569 out:
1570         return ret;
1571 }
1572 EXPORT_SYMBOL(dquot_claim_space);
1573
1574 /*
1575  * Release reserved quota space
1576  */
1577 void dquot_release_reserved_space(struct inode *inode, qsize_t number)
1578 {
1579         int cnt;
1580
1581         if (IS_NOQUOTA(inode))
1582                 goto out;
1583
1584         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1585         if (IS_NOQUOTA(inode))
1586                 goto out_unlock;
1587
1588         spin_lock(&dq_data_lock);
1589         /* Release reserved dquots */
1590         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1591                 if (inode->i_dquot[cnt])
1592                         dquot_free_reserved_space(inode->i_dquot[cnt], number);
1593         }
1594         spin_unlock(&dq_data_lock);
1595
1596 out_unlock:
1597         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1598 out:
1599         return;
1600 }
1601 EXPORT_SYMBOL(dquot_release_reserved_space);
1602
1603 /*
1604  * This operation can block, but only after everything is updated
1605  */
1606 int dquot_free_space(struct inode *inode, qsize_t number)
1607 {
1608         unsigned int cnt;
1609         char warntype[MAXQUOTAS];
1610
1611         /* First test before acquiring mutex - solves deadlocks when we
1612          * re-enter the quota code and are already holding the mutex */
1613         if (IS_NOQUOTA(inode)) {
1614 out_sub:
1615                 inode_sub_bytes(inode, number);
1616                 return QUOTA_OK;
1617         }
1618
1619         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1620         /* Now recheck reliably when holding dqptr_sem */
1621         if (IS_NOQUOTA(inode)) {
1622                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1623                 goto out_sub;
1624         }
1625         spin_lock(&dq_data_lock);
1626         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1627                 if (!inode->i_dquot[cnt])
1628                         continue;
1629                 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
1630                 dquot_decr_space(inode->i_dquot[cnt], number);
1631         }
1632         inode_sub_bytes(inode, number);
1633         spin_unlock(&dq_data_lock);
1634         /* Dirtify all the dquots - this can block when journalling */
1635         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1636                 if (inode->i_dquot[cnt])
1637                         mark_dquot_dirty(inode->i_dquot[cnt]);
1638         flush_warnings(inode->i_dquot, warntype);
1639         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1640         return QUOTA_OK;
1641 }
1642 EXPORT_SYMBOL(dquot_free_space);
1643
1644 /*
1645  * This operation can block, but only after everything is updated
1646  */
1647 int dquot_free_inode(const struct inode *inode, qsize_t number)
1648 {
1649         unsigned int cnt;
1650         char warntype[MAXQUOTAS];
1651
1652         /* First test before acquiring mutex - solves deadlocks when we
1653          * re-enter the quota code and are already holding the mutex */
1654         if (IS_NOQUOTA(inode))
1655                 return QUOTA_OK;
1656
1657         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1658         /* Now recheck reliably when holding dqptr_sem */
1659         if (IS_NOQUOTA(inode)) {
1660                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1661                 return QUOTA_OK;
1662         }
1663         spin_lock(&dq_data_lock);
1664         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1665                 if (!inode->i_dquot[cnt])
1666                         continue;
1667                 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], number);
1668                 dquot_decr_inodes(inode->i_dquot[cnt], number);
1669         }
1670         spin_unlock(&dq_data_lock);
1671         /* Dirtify all the dquots - this can block when journalling */
1672         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1673                 if (inode->i_dquot[cnt])
1674                         mark_dquot_dirty(inode->i_dquot[cnt]);
1675         flush_warnings(inode->i_dquot, warntype);
1676         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1677         return QUOTA_OK;
1678 }
1679 EXPORT_SYMBOL(dquot_free_inode);
1680
1681 /*
1682  * call back function, get reserved quota space from underlying fs
1683  */
1684 qsize_t dquot_get_reserved_space(struct inode *inode)
1685 {
1686         qsize_t reserved_space = 0;
1687
1688         if (sb_any_quota_active(inode->i_sb) &&
1689             inode->i_sb->dq_op->get_reserved_space)
1690                 reserved_space = inode->i_sb->dq_op->get_reserved_space(inode);
1691         return reserved_space;
1692 }
1693
1694 /*
1695  * Transfer the number of inode and blocks from one diskquota to an other.
1696  *
1697  * This operation can block, but only after everything is updated
1698  * A transaction must be started when entering this function.
1699  */
1700 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1701 {
1702         qsize_t space, cur_space;
1703         qsize_t rsv_space = 0;
1704         struct dquot *transfer_from[MAXQUOTAS];
1705         struct dquot *transfer_to[MAXQUOTAS];
1706         int cnt, ret = QUOTA_OK;
1707         int chuid = iattr->ia_valid & ATTR_UID && inode->i_uid != iattr->ia_uid,
1708             chgid = iattr->ia_valid & ATTR_GID && inode->i_gid != iattr->ia_gid;
1709         char warntype_to[MAXQUOTAS];
1710         char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
1711
1712         /* First test before acquiring mutex - solves deadlocks when we
1713          * re-enter the quota code and are already holding the mutex */
1714         if (IS_NOQUOTA(inode))
1715                 return QUOTA_OK;
1716         /* Initialize the arrays */
1717         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1718                 transfer_from[cnt] = NULL;
1719                 transfer_to[cnt] = NULL;
1720                 warntype_to[cnt] = QUOTA_NL_NOWARN;
1721         }
1722         if (chuid)
1723                 transfer_to[USRQUOTA] = dqget(inode->i_sb, iattr->ia_uid,
1724                                               USRQUOTA);
1725         if (chgid)
1726                 transfer_to[GRPQUOTA] = dqget(inode->i_sb, iattr->ia_gid,
1727                                               GRPQUOTA);
1728
1729         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1730         /* Now recheck reliably when holding dqptr_sem */
1731         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1732                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1733                 goto put_all;
1734         }
1735         spin_lock(&dq_data_lock);
1736         cur_space = inode_get_bytes(inode);
1737         rsv_space = dquot_get_reserved_space(inode);
1738         space = cur_space + rsv_space;
1739         /* Build the transfer_from list and check the limits */
1740         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1741                 if (!transfer_to[cnt])
1742                         continue;
1743                 transfer_from[cnt] = inode->i_dquot[cnt];
1744                 if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) ==
1745                     NO_QUOTA || check_bdq(transfer_to[cnt], space, 0,
1746                     warntype_to + cnt) == NO_QUOTA)
1747                         goto over_quota;
1748         }
1749
1750         /*
1751          * Finally perform the needed transfer from transfer_from to transfer_to
1752          */
1753         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1754                 /*
1755                  * Skip changes for same uid or gid or for turned off quota-type.
1756                  */
1757                 if (!transfer_to[cnt])
1758                         continue;
1759
1760                 /* Due to IO error we might not have transfer_from[] structure */
1761                 if (transfer_from[cnt]) {
1762                         warntype_from_inodes[cnt] =
1763                                 info_idq_free(transfer_from[cnt], 1);
1764                         warntype_from_space[cnt] =
1765                                 info_bdq_free(transfer_from[cnt], space);
1766                         dquot_decr_inodes(transfer_from[cnt], 1);
1767                         dquot_decr_space(transfer_from[cnt], cur_space);
1768                         dquot_free_reserved_space(transfer_from[cnt],
1769                                                   rsv_space);
1770                 }
1771
1772                 dquot_incr_inodes(transfer_to[cnt], 1);
1773                 dquot_incr_space(transfer_to[cnt], cur_space);
1774                 dquot_resv_space(transfer_to[cnt], rsv_space);
1775
1776                 inode->i_dquot[cnt] = transfer_to[cnt];
1777         }
1778         spin_unlock(&dq_data_lock);
1779         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1780
1781         /* Dirtify all the dquots - this can block when journalling */
1782         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1783                 if (transfer_from[cnt])
1784                         mark_dquot_dirty(transfer_from[cnt]);
1785                 if (transfer_to[cnt]) {
1786                         mark_dquot_dirty(transfer_to[cnt]);
1787                         /* The reference we got is transferred to the inode */
1788                         transfer_to[cnt] = NULL;
1789                 }
1790         }
1791 warn_put_all:
1792         flush_warnings(transfer_to, warntype_to);
1793         flush_warnings(transfer_from, warntype_from_inodes);
1794         flush_warnings(transfer_from, warntype_from_space);
1795 put_all:
1796         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1797                 dqput(transfer_from[cnt]);
1798                 dqput(transfer_to[cnt]);
1799         }
1800         return ret;
1801 over_quota:
1802         spin_unlock(&dq_data_lock);
1803         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1804         /* Clear dquot pointers we don't want to dqput() */
1805         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1806                 transfer_from[cnt] = NULL;
1807         ret = NO_QUOTA;
1808         goto warn_put_all;
1809 }
1810 EXPORT_SYMBOL(dquot_transfer);
1811
1812 /* Wrapper for transferring ownership of an inode */
1813 int vfs_dq_transfer(struct inode *inode, struct iattr *iattr)
1814 {
1815         if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) {
1816                 vfs_dq_init(inode);
1817                 if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA)
1818                         return 1;
1819         }
1820         return 0;
1821 }
1822 EXPORT_SYMBOL(vfs_dq_transfer);
1823
1824 /*
1825  * Write info of quota file to disk
1826  */
1827 int dquot_commit_info(struct super_block *sb, int type)
1828 {
1829         int ret;
1830         struct quota_info *dqopt = sb_dqopt(sb);
1831
1832         mutex_lock(&dqopt->dqio_mutex);
1833         ret = dqopt->ops[type]->write_file_info(sb, type);
1834         mutex_unlock(&dqopt->dqio_mutex);
1835         return ret;
1836 }
1837 EXPORT_SYMBOL(dquot_commit_info);
1838
1839 /*
1840  * Definitions of diskquota operations.
1841  */
1842 const struct dquot_operations dquot_operations = {
1843         .initialize     = dquot_initialize,
1844         .drop           = dquot_drop,
1845         .alloc_space    = dquot_alloc_space,
1846         .alloc_inode    = dquot_alloc_inode,
1847         .free_space     = dquot_free_space,
1848         .free_inode     = dquot_free_inode,
1849         .transfer       = dquot_transfer,
1850         .write_dquot    = dquot_commit,
1851         .acquire_dquot  = dquot_acquire,
1852         .release_dquot  = dquot_release,
1853         .mark_dirty     = dquot_mark_dquot_dirty,
1854         .write_info     = dquot_commit_info,
1855         .alloc_dquot    = dquot_alloc,
1856         .destroy_dquot  = dquot_destroy,
1857 };
1858
1859 /*
1860  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1861  */
1862 int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags)
1863 {
1864         int cnt, ret = 0;
1865         struct quota_info *dqopt = sb_dqopt(sb);
1866         struct inode *toputinode[MAXQUOTAS];
1867
1868         /* Cannot turn off usage accounting without turning off limits, or
1869          * suspend quotas and simultaneously turn quotas off. */
1870         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1871             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1872             DQUOT_USAGE_ENABLED)))
1873                 return -EINVAL;
1874
1875         /* We need to serialize quota_off() for device */
1876         mutex_lock(&dqopt->dqonoff_mutex);
1877
1878         /*
1879          * Skip everything if there's nothing to do. We have to do this because
1880          * sometimes we are called when fill_super() failed and calling
1881          * sync_fs() in such cases does no good.
1882          */
1883         if (!sb_any_quota_loaded(sb)) {
1884                 mutex_unlock(&dqopt->dqonoff_mutex);
1885                 return 0;
1886         }
1887         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1888                 toputinode[cnt] = NULL;
1889                 if (type != -1 && cnt != type)
1890                         continue;
1891                 if (!sb_has_quota_loaded(sb, cnt))
1892                         continue;
1893
1894                 if (flags & DQUOT_SUSPENDED) {
1895                         spin_lock(&dq_state_lock);
1896                         dqopt->flags |=
1897                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1898                         spin_unlock(&dq_state_lock);
1899                 } else {
1900                         spin_lock(&dq_state_lock);
1901                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
1902                         /* Turning off suspended quotas? */
1903                         if (!sb_has_quota_loaded(sb, cnt) &&
1904                             sb_has_quota_suspended(sb, cnt)) {
1905                                 dqopt->flags &= ~dquot_state_flag(
1906                                                         DQUOT_SUSPENDED, cnt);
1907                                 spin_unlock(&dq_state_lock);
1908                                 iput(dqopt->files[cnt]);
1909                                 dqopt->files[cnt] = NULL;
1910                                 continue;
1911                         }
1912                         spin_unlock(&dq_state_lock);
1913                 }
1914
1915                 /* We still have to keep quota loaded? */
1916                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
1917                         continue;
1918
1919                 /* Note: these are blocking operations */
1920                 drop_dquot_ref(sb, cnt);
1921                 invalidate_dquots(sb, cnt);
1922                 /*
1923                  * Now all dquots should be invalidated, all writes done so we
1924                  * should be only users of the info. No locks needed.
1925                  */
1926                 if (info_dirty(&dqopt->info[cnt]))
1927                         sb->dq_op->write_info(sb, cnt);
1928                 if (dqopt->ops[cnt]->free_file_info)
1929                         dqopt->ops[cnt]->free_file_info(sb, cnt);
1930                 put_quota_format(dqopt->info[cnt].dqi_format);
1931
1932                 toputinode[cnt] = dqopt->files[cnt];
1933                 if (!sb_has_quota_loaded(sb, cnt))
1934                         dqopt->files[cnt] = NULL;
1935                 dqopt->info[cnt].dqi_flags = 0;
1936                 dqopt->info[cnt].dqi_igrace = 0;
1937                 dqopt->info[cnt].dqi_bgrace = 0;
1938                 dqopt->ops[cnt] = NULL;
1939         }
1940         mutex_unlock(&dqopt->dqonoff_mutex);
1941
1942         /* Skip syncing and setting flags if quota files are hidden */
1943         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
1944                 goto put_inodes;
1945
1946         /* Sync the superblock so that buffers with quota data are written to
1947          * disk (and so userspace sees correct data afterwards). */
1948         if (sb->s_op->sync_fs)
1949                 sb->s_op->sync_fs(sb, 1);
1950         sync_blockdev(sb->s_bdev);
1951         /* Now the quota files are just ordinary files and we can set the
1952          * inode flags back. Moreover we discard the pagecache so that
1953          * userspace sees the writes we did bypassing the pagecache. We
1954          * must also discard the blockdev buffers so that we see the
1955          * changes done by userspace on the next quotaon() */
1956         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1957                 if (toputinode[cnt]) {
1958                         mutex_lock(&dqopt->dqonoff_mutex);
1959                         /* If quota was reenabled in the meantime, we have
1960                          * nothing to do */
1961                         if (!sb_has_quota_loaded(sb, cnt)) {
1962                                 mutex_lock_nested(&toputinode[cnt]->i_mutex,
1963                                                   I_MUTEX_QUOTA);
1964                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1965                                   S_NOATIME | S_NOQUOTA);
1966                                 truncate_inode_pages(&toputinode[cnt]->i_data,
1967                                                      0);
1968                                 mutex_unlock(&toputinode[cnt]->i_mutex);
1969                                 mark_inode_dirty(toputinode[cnt]);
1970                         }
1971                         mutex_unlock(&dqopt->dqonoff_mutex);
1972                 }
1973         if (sb->s_bdev)
1974                 invalidate_bdev(sb->s_bdev);
1975 put_inodes:
1976         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1977                 if (toputinode[cnt]) {
1978                         /* On remount RO, we keep the inode pointer so that we
1979                          * can reenable quota on the subsequent remount RW. We
1980                          * have to check 'flags' variable and not use sb_has_
1981                          * function because another quotaon / quotaoff could
1982                          * change global state before we got here. We refuse
1983                          * to suspend quotas when there is pending delete on
1984                          * the quota file... */
1985                         if (!(flags & DQUOT_SUSPENDED))
1986                                 iput(toputinode[cnt]);
1987                         else if (!toputinode[cnt]->i_nlink)
1988                                 ret = -EBUSY;
1989                 }
1990         return ret;
1991 }
1992 EXPORT_SYMBOL(vfs_quota_disable);
1993
1994 int vfs_quota_off(struct super_block *sb, int type, int remount)
1995 {
1996         return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED :
1997                                  (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED));
1998 }
1999 EXPORT_SYMBOL(vfs_quota_off);
2000 /*
2001  *      Turn quotas on on a device
2002  */
2003
2004 /*
2005  * Helper function to turn quotas on when we already have the inode of
2006  * quota file and no quota information is loaded.
2007  */
2008 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2009         unsigned int flags)
2010 {
2011         struct quota_format_type *fmt = find_quota_format(format_id);
2012         struct super_block *sb = inode->i_sb;
2013         struct quota_info *dqopt = sb_dqopt(sb);
2014         int error;
2015         int oldflags = -1;
2016
2017         if (!fmt)
2018                 return -ESRCH;
2019         if (!S_ISREG(inode->i_mode)) {
2020                 error = -EACCES;
2021                 goto out_fmt;
2022         }
2023         if (IS_RDONLY(inode)) {
2024                 error = -EROFS;
2025                 goto out_fmt;
2026         }
2027         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
2028                 error = -EINVAL;
2029                 goto out_fmt;
2030         }
2031         /* Usage always has to be set... */
2032         if (!(flags & DQUOT_USAGE_ENABLED)) {
2033                 error = -EINVAL;
2034                 goto out_fmt;
2035         }
2036
2037         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2038                 /* As we bypass the pagecache we must now flush the inode so
2039                  * that we see all the changes from userspace... */
2040                 write_inode_now(inode, 1);
2041                 /* And now flush the block cache so that kernel sees the
2042                  * changes */
2043                 invalidate_bdev(sb->s_bdev);
2044         }
2045         mutex_lock(&dqopt->dqonoff_mutex);
2046         if (sb_has_quota_loaded(sb, type)) {
2047                 error = -EBUSY;
2048                 goto out_lock;
2049         }
2050
2051         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2052                 /* We don't want quota and atime on quota files (deadlocks
2053                  * possible) Also nobody should write to the file - we use
2054                  * special IO operations which ignore the immutable bit. */
2055                 down_write(&dqopt->dqptr_sem);
2056                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2057                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2058                                              S_NOQUOTA);
2059                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2060                 mutex_unlock(&inode->i_mutex);
2061                 up_write(&dqopt->dqptr_sem);
2062                 sb->dq_op->drop(inode);
2063         }
2064
2065         error = -EIO;
2066         dqopt->files[type] = igrab(inode);
2067         if (!dqopt->files[type])
2068                 goto out_lock;
2069         error = -EINVAL;
2070         if (!fmt->qf_ops->check_quota_file(sb, type))
2071                 goto out_file_init;
2072
2073         dqopt->ops[type] = fmt->qf_ops;
2074         dqopt->info[type].dqi_format = fmt;
2075         dqopt->info[type].dqi_fmt_id = format_id;
2076         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2077         mutex_lock(&dqopt->dqio_mutex);
2078         error = dqopt->ops[type]->read_file_info(sb, type);
2079         if (error < 0) {
2080                 mutex_unlock(&dqopt->dqio_mutex);
2081                 goto out_file_init;
2082         }
2083         mutex_unlock(&dqopt->dqio_mutex);
2084         spin_lock(&dq_state_lock);
2085         dqopt->flags |= dquot_state_flag(flags, type);
2086         spin_unlock(&dq_state_lock);
2087
2088         add_dquot_ref(sb, type);
2089         mutex_unlock(&dqopt->dqonoff_mutex);
2090
2091         return 0;
2092
2093 out_file_init:
2094         dqopt->files[type] = NULL;
2095         iput(inode);
2096 out_lock:
2097         if (oldflags != -1) {
2098                 down_write(&dqopt->dqptr_sem);
2099                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2100                 /* Set the flags back (in the case of accidental quotaon()
2101                  * on a wrong file we don't want to mess up the flags) */
2102                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2103                 inode->i_flags |= oldflags;
2104                 mutex_unlock(&inode->i_mutex);
2105                 up_write(&dqopt->dqptr_sem);
2106         }
2107         mutex_unlock(&dqopt->dqonoff_mutex);
2108 out_fmt:
2109         put_quota_format(fmt);
2110
2111         return error; 
2112 }
2113
2114 /* Reenable quotas on remount RW */
2115 static int vfs_quota_on_remount(struct super_block *sb, int type)
2116 {
2117         struct quota_info *dqopt = sb_dqopt(sb);
2118         struct inode *inode;
2119         int ret;
2120         unsigned int flags;
2121
2122         mutex_lock(&dqopt->dqonoff_mutex);
2123         if (!sb_has_quota_suspended(sb, type)) {
2124                 mutex_unlock(&dqopt->dqonoff_mutex);
2125                 return 0;
2126         }
2127         inode = dqopt->files[type];
2128         dqopt->files[type] = NULL;
2129         spin_lock(&dq_state_lock);
2130         flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2131                                                 DQUOT_LIMITS_ENABLED, type);
2132         dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type);
2133         spin_unlock(&dq_state_lock);
2134         mutex_unlock(&dqopt->dqonoff_mutex);
2135
2136         flags = dquot_generic_flag(flags, type);
2137         ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id,
2138                                    flags);
2139         iput(inode);
2140
2141         return ret;
2142 }
2143
2144 int vfs_quota_on_path(struct super_block *sb, int type, int format_id,
2145                       struct path *path)
2146 {
2147         int error = security_quota_on(path->dentry);
2148         if (error)
2149                 return error;
2150         /* Quota file not on the same filesystem? */
2151         if (path->mnt->mnt_sb != sb)
2152                 error = -EXDEV;
2153         else
2154                 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2155                                              format_id, DQUOT_USAGE_ENABLED |
2156                                              DQUOT_LIMITS_ENABLED);
2157         return error;
2158 }
2159 EXPORT_SYMBOL(vfs_quota_on_path);
2160
2161 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name,
2162                  int remount)
2163 {
2164         struct path path;
2165         int error;
2166
2167         if (remount)
2168                 return vfs_quota_on_remount(sb, type);
2169
2170         error = kern_path(name, LOOKUP_FOLLOW, &path);
2171         if (!error) {
2172                 error = vfs_quota_on_path(sb, type, format_id, &path);
2173                 path_put(&path);
2174         }
2175         return error;
2176 }
2177 EXPORT_SYMBOL(vfs_quota_on);
2178
2179 /*
2180  * More powerful function for turning on quotas allowing setting
2181  * of individual quota flags
2182  */
2183 int vfs_quota_enable(struct inode *inode, int type, int format_id,
2184                 unsigned int flags)
2185 {
2186         int ret = 0;
2187         struct super_block *sb = inode->i_sb;
2188         struct quota_info *dqopt = sb_dqopt(sb);
2189
2190         /* Just unsuspend quotas? */
2191         if (flags & DQUOT_SUSPENDED)
2192                 return vfs_quota_on_remount(sb, type);
2193         if (!flags)
2194                 return 0;
2195         /* Just updating flags needed? */
2196         if (sb_has_quota_loaded(sb, type)) {
2197                 mutex_lock(&dqopt->dqonoff_mutex);
2198                 /* Now do a reliable test... */
2199                 if (!sb_has_quota_loaded(sb, type)) {
2200                         mutex_unlock(&dqopt->dqonoff_mutex);
2201                         goto load_quota;
2202                 }
2203                 if (flags & DQUOT_USAGE_ENABLED &&
2204                     sb_has_quota_usage_enabled(sb, type)) {
2205                         ret = -EBUSY;
2206                         goto out_lock;
2207                 }
2208                 if (flags & DQUOT_LIMITS_ENABLED &&
2209                     sb_has_quota_limits_enabled(sb, type)) {
2210                         ret = -EBUSY;
2211                         goto out_lock;
2212                 }
2213                 spin_lock(&dq_state_lock);
2214                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2215                 spin_unlock(&dq_state_lock);
2216 out_lock:
2217                 mutex_unlock(&dqopt->dqonoff_mutex);
2218                 return ret;
2219         }
2220
2221 load_quota:
2222         return vfs_load_quota_inode(inode, type, format_id, flags);
2223 }
2224 EXPORT_SYMBOL(vfs_quota_enable);
2225
2226 /*
2227  * This function is used when filesystem needs to initialize quotas
2228  * during mount time.
2229  */
2230 int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
2231                 int format_id, int type)
2232 {
2233         struct dentry *dentry;
2234         int error;
2235
2236         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2237         if (IS_ERR(dentry))
2238                 return PTR_ERR(dentry);
2239
2240         if (!dentry->d_inode) {
2241                 error = -ENOENT;
2242                 goto out;
2243         }
2244
2245         error = security_quota_on(dentry);
2246         if (!error)
2247                 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2248                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2249
2250 out:
2251         dput(dentry);
2252         return error;
2253 }
2254 EXPORT_SYMBOL(vfs_quota_on_mount);
2255
2256 /* Wrapper to turn on quotas when remounting rw */
2257 int vfs_dq_quota_on_remount(struct super_block *sb)
2258 {
2259         int cnt;
2260         int ret = 0, err;
2261
2262         if (!sb->s_qcop || !sb->s_qcop->quota_on)
2263                 return -ENOSYS;
2264         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2265                 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1);
2266                 if (err < 0 && !ret)
2267                         ret = err;
2268         }
2269         return ret;
2270 }
2271 EXPORT_SYMBOL(vfs_dq_quota_on_remount);
2272
2273 static inline qsize_t qbtos(qsize_t blocks)
2274 {
2275         return blocks << QIF_DQBLKSIZE_BITS;
2276 }
2277
2278 static inline qsize_t stoqb(qsize_t space)
2279 {
2280         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2281 }
2282
2283 /* Generic routine for getting common part of quota structure */
2284 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
2285 {
2286         struct mem_dqblk *dm = &dquot->dq_dqb;
2287
2288         spin_lock(&dq_data_lock);
2289         di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit);
2290         di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit);
2291         di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace;
2292         di->dqb_ihardlimit = dm->dqb_ihardlimit;
2293         di->dqb_isoftlimit = dm->dqb_isoftlimit;
2294         di->dqb_curinodes = dm->dqb_curinodes;
2295         di->dqb_btime = dm->dqb_btime;
2296         di->dqb_itime = dm->dqb_itime;
2297         di->dqb_valid = QIF_ALL;
2298         spin_unlock(&dq_data_lock);
2299 }
2300
2301 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id,
2302                   struct if_dqblk *di)
2303 {
2304         struct dquot *dquot;
2305
2306         dquot = dqget(sb, id, type);
2307         if (!dquot)
2308                 return -ESRCH;
2309         do_get_dqblk(dquot, di);
2310         dqput(dquot);
2311
2312         return 0;
2313 }
2314 EXPORT_SYMBOL(vfs_get_dqblk);
2315
2316 /* Generic routine for setting common part of quota structure */
2317 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
2318 {
2319         struct mem_dqblk *dm = &dquot->dq_dqb;
2320         int check_blim = 0, check_ilim = 0;
2321         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2322
2323         if ((di->dqb_valid & QIF_BLIMITS &&
2324              (di->dqb_bhardlimit > dqi->dqi_maxblimit ||
2325               di->dqb_bsoftlimit > dqi->dqi_maxblimit)) ||
2326             (di->dqb_valid & QIF_ILIMITS &&
2327              (di->dqb_ihardlimit > dqi->dqi_maxilimit ||
2328               di->dqb_isoftlimit > dqi->dqi_maxilimit)))
2329                 return -ERANGE;
2330
2331         spin_lock(&dq_data_lock);
2332         if (di->dqb_valid & QIF_SPACE) {
2333                 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace;
2334                 check_blim = 1;
2335                 __set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2336         }
2337         if (di->dqb_valid & QIF_BLIMITS) {
2338                 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit);
2339                 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit);
2340                 check_blim = 1;
2341                 __set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2342         }
2343         if (di->dqb_valid & QIF_INODES) {
2344                 dm->dqb_curinodes = di->dqb_curinodes;
2345                 check_ilim = 1;
2346                 __set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2347         }
2348         if (di->dqb_valid & QIF_ILIMITS) {
2349                 dm->dqb_isoftlimit = di->dqb_isoftlimit;
2350                 dm->dqb_ihardlimit = di->dqb_ihardlimit;
2351                 check_ilim = 1;
2352                 __set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2353         }
2354         if (di->dqb_valid & QIF_BTIME) {
2355                 dm->dqb_btime = di->dqb_btime;
2356                 check_blim = 1;
2357                 __set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2358         }
2359         if (di->dqb_valid & QIF_ITIME) {
2360                 dm->dqb_itime = di->dqb_itime;
2361                 check_ilim = 1;
2362                 __set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2363         }
2364
2365         if (check_blim) {
2366                 if (!dm->dqb_bsoftlimit ||
2367                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2368                         dm->dqb_btime = 0;
2369                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2370                 } else if (!(di->dqb_valid & QIF_BTIME))
2371                         /* Set grace only if user hasn't provided his own... */
2372                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2373         }
2374         if (check_ilim) {
2375                 if (!dm->dqb_isoftlimit ||
2376                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2377                         dm->dqb_itime = 0;
2378                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2379                 } else if (!(di->dqb_valid & QIF_ITIME))
2380                         /* Set grace only if user hasn't provided his own... */
2381                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2382         }
2383         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2384             dm->dqb_isoftlimit)
2385                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2386         else
2387                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2388         spin_unlock(&dq_data_lock);
2389         mark_dquot_dirty(dquot);
2390
2391         return 0;
2392 }
2393
2394 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id,
2395                   struct if_dqblk *di)
2396 {
2397         struct dquot *dquot;
2398         int rc;
2399
2400         dquot = dqget(sb, id, type);
2401         if (!dquot) {
2402                 rc = -ESRCH;
2403                 goto out;
2404         }
2405         rc = do_set_dqblk(dquot, di);
2406         dqput(dquot);
2407 out:
2408         return rc;
2409 }
2410 EXPORT_SYMBOL(vfs_set_dqblk);
2411
2412 /* Generic routine for getting common part of quota file information */
2413 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2414 {
2415         struct mem_dqinfo *mi;
2416   
2417         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2418         if (!sb_has_quota_active(sb, type)) {
2419                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2420                 return -ESRCH;
2421         }
2422         mi = sb_dqopt(sb)->info + type;
2423         spin_lock(&dq_data_lock);
2424         ii->dqi_bgrace = mi->dqi_bgrace;
2425         ii->dqi_igrace = mi->dqi_igrace;
2426         ii->dqi_flags = mi->dqi_flags & DQF_MASK;
2427         ii->dqi_valid = IIF_ALL;
2428         spin_unlock(&dq_data_lock);
2429         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2430         return 0;
2431 }
2432 EXPORT_SYMBOL(vfs_get_dqinfo);
2433
2434 /* Generic routine for setting common part of quota file information */
2435 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2436 {
2437         struct mem_dqinfo *mi;
2438         int err = 0;
2439
2440         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2441         if (!sb_has_quota_active(sb, type)) {
2442                 err = -ESRCH;
2443                 goto out;
2444         }
2445         mi = sb_dqopt(sb)->info + type;
2446         spin_lock(&dq_data_lock);
2447         if (ii->dqi_valid & IIF_BGRACE)
2448                 mi->dqi_bgrace = ii->dqi_bgrace;
2449         if (ii->dqi_valid & IIF_IGRACE)
2450                 mi->dqi_igrace = ii->dqi_igrace;
2451         if (ii->dqi_valid & IIF_FLAGS)
2452                 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) |
2453                                 (ii->dqi_flags & DQF_MASK);
2454         spin_unlock(&dq_data_lock);
2455         mark_info_dirty(sb, type);
2456         /* Force write to disk */
2457         sb->dq_op->write_info(sb, type);
2458 out:
2459         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2460         return err;
2461 }
2462 EXPORT_SYMBOL(vfs_set_dqinfo);
2463
2464 const struct quotactl_ops vfs_quotactl_ops = {
2465         .quota_on       = vfs_quota_on,
2466         .quota_off      = vfs_quota_off,
2467         .quota_sync     = vfs_quota_sync,
2468         .get_info       = vfs_get_dqinfo,
2469         .set_info       = vfs_set_dqinfo,
2470         .get_dqblk      = vfs_get_dqblk,
2471         .set_dqblk      = vfs_set_dqblk
2472 };
2473
2474 static ctl_table fs_dqstats_table[] = {
2475         {
2476                 .procname       = "lookups",
2477                 .data           = &dqstats.lookups,
2478                 .maxlen         = sizeof(int),
2479                 .mode           = 0444,
2480                 .proc_handler   = proc_dointvec,
2481         },
2482         {
2483                 .procname       = "drops",
2484                 .data           = &dqstats.drops,
2485                 .maxlen         = sizeof(int),
2486                 .mode           = 0444,
2487                 .proc_handler   = proc_dointvec,
2488         },
2489         {
2490                 .procname       = "reads",
2491                 .data           = &dqstats.reads,
2492                 .maxlen         = sizeof(int),
2493                 .mode           = 0444,
2494                 .proc_handler   = proc_dointvec,
2495         },
2496         {
2497                 .procname       = "writes",
2498                 .data           = &dqstats.writes,
2499                 .maxlen         = sizeof(int),
2500                 .mode           = 0444,
2501                 .proc_handler   = proc_dointvec,
2502         },
2503         {
2504                 .procname       = "cache_hits",
2505                 .data           = &dqstats.cache_hits,
2506                 .maxlen         = sizeof(int),
2507                 .mode           = 0444,
2508                 .proc_handler   = proc_dointvec,
2509         },
2510         {
2511                 .procname       = "allocated_dquots",
2512                 .data           = &dqstats.allocated_dquots,
2513                 .maxlen         = sizeof(int),
2514                 .mode           = 0444,
2515                 .proc_handler   = proc_dointvec,
2516         },
2517         {
2518                 .procname       = "free_dquots",
2519                 .data           = &dqstats.free_dquots,
2520                 .maxlen         = sizeof(int),
2521                 .mode           = 0444,
2522                 .proc_handler   = proc_dointvec,
2523         },
2524         {
2525                 .procname       = "syncs",
2526                 .data           = &dqstats.syncs,
2527                 .maxlen         = sizeof(int),
2528                 .mode           = 0444,
2529                 .proc_handler   = proc_dointvec,
2530         },
2531 #ifdef CONFIG_PRINT_QUOTA_WARNING
2532         {
2533                 .procname       = "warnings",
2534                 .data           = &flag_print_warnings,
2535                 .maxlen         = sizeof(int),
2536                 .mode           = 0644,
2537                 .proc_handler   = proc_dointvec,
2538         },
2539 #endif
2540         { },
2541 };
2542
2543 static ctl_table fs_table[] = {
2544         {
2545                 .procname       = "quota",
2546                 .mode           = 0555,
2547                 .child          = fs_dqstats_table,
2548         },
2549         { },
2550 };
2551
2552 static ctl_table sys_table[] = {
2553         {
2554                 .procname       = "fs",
2555                 .mode           = 0555,
2556                 .child          = fs_table,
2557         },
2558         { },
2559 };
2560
2561 static int __init dquot_init(void)
2562 {
2563         int i;
2564         unsigned long nr_hash, order;
2565
2566         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2567
2568         register_sysctl_table(sys_table);
2569
2570         dquot_cachep = kmem_cache_create("dquot",
2571                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2572                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2573                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2574                         NULL);
2575
2576         order = 0;
2577         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2578         if (!dquot_hash)
2579                 panic("Cannot create dquot hash table");
2580
2581         /* Find power-of-two hlist_heads which can fit into allocation */
2582         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2583         dq_hash_bits = 0;
2584         do {
2585                 dq_hash_bits++;
2586         } while (nr_hash >> dq_hash_bits);
2587         dq_hash_bits--;
2588
2589         nr_hash = 1UL << dq_hash_bits;
2590         dq_hash_mask = nr_hash - 1;
2591         for (i = 0; i < nr_hash; i++)
2592                 INIT_HLIST_HEAD(dquot_hash + i);
2593
2594         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2595                         nr_hash, order, (PAGE_SIZE << order));
2596
2597         register_shrinker(&dqcache_shrinker);
2598
2599 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
2600         if (genl_register_family(&quota_genl_family) != 0)
2601                 printk(KERN_ERR
2602                        "VFS: Failed to create quota netlink interface.\n");
2603 #endif
2604
2605         return 0;
2606 }
2607 module_init(dquot_init);