quota: Coding style fixes
[linux-2.6.git] / fs / quota / dquot.c
1 /*
2  * Implementation of the diskquota system for the LINUX operating system. QUOTA
3  * is implemented using the BSD system call interface as the means of
4  * communication with the user level. This file contains the generic routines
5  * called by the different filesystems on allocation of an inode or block.
6  * These routines take care of the administration needed to have a consistent
7  * diskquota tracking system. The ideas of both user and group quotas are based
8  * on the Melbourne quota system as used on BSD derived systems. The internal
9  * implementation is based on one of the several variants of the LINUX
10  * inode-subsystem with added complexity of the diskquota system.
11  * 
12  * Author:      Marco van Wieringen <mvw@planets.elm.net>
13  *
14  * Fixes:   Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
15  *
16  *              Revised list management to avoid races
17  *              -- Bill Hawes, <whawes@star.net>, 9/98
18  *
19  *              Fixed races in dquot_transfer(), dqget() and dquot_alloc_...().
20  *              As the consequence the locking was moved from dquot_decr_...(),
21  *              dquot_incr_...() to calling functions.
22  *              invalidate_dquots() now writes modified dquots.
23  *              Serialized quota_off() and quota_on() for mount point.
24  *              Fixed a few bugs in grow_dquots().
25  *              Fixed deadlock in write_dquot() - we no longer account quotas on
26  *              quota files
27  *              remove_dquot_ref() moved to inode.c - it now traverses through inodes
28  *              add_dquot_ref() restarts after blocking
29  *              Added check for bogus uid and fixed check for group in quotactl.
30  *              Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99
31  *
32  *              Used struct list_head instead of own list struct
33  *              Invalidation of referenced dquots is no longer possible
34  *              Improved free_dquots list management
35  *              Quota and i_blocks are now updated in one place to avoid races
36  *              Warnings are now delayed so we won't block in critical section
37  *              Write updated not to require dquot lock
38  *              Jan Kara, <jack@suse.cz>, 9/2000
39  *
40  *              Added dynamic quota structure allocation
41  *              Jan Kara <jack@suse.cz> 12/2000
42  *
43  *              Rewritten quota interface. Implemented new quota format and
44  *              formats registering.
45  *              Jan Kara, <jack@suse.cz>, 2001,2002
46  *
47  *              New SMP locking.
48  *              Jan Kara, <jack@suse.cz>, 10/2002
49  *
50  *              Added journalled quota support, fix lock inversion problems
51  *              Jan Kara, <jack@suse.cz>, 2003,2004
52  *
53  * (C) Copyright 1994 - 1997 Marco van Wieringen 
54  */
55
56 #include <linux/errno.h>
57 #include <linux/kernel.h>
58 #include <linux/fs.h>
59 #include <linux/mount.h>
60 #include <linux/mm.h>
61 #include <linux/time.h>
62 #include <linux/types.h>
63 #include <linux/string.h>
64 #include <linux/fcntl.h>
65 #include <linux/stat.h>
66 #include <linux/tty.h>
67 #include <linux/file.h>
68 #include <linux/slab.h>
69 #include <linux/sysctl.h>
70 #include <linux/init.h>
71 #include <linux/module.h>
72 #include <linux/proc_fs.h>
73 #include <linux/security.h>
74 #include <linux/kmod.h>
75 #include <linux/namei.h>
76 #include <linux/buffer_head.h>
77 #include <linux/capability.h>
78 #include <linux/quotaops.h>
79 #include <linux/writeback.h> /* for inode_lock, oddly enough.. */
80 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
81 #include <net/netlink.h>
82 #include <net/genetlink.h>
83 #endif
84
85 #include <asm/uaccess.h>
86
87 #define __DQUOT_PARANOIA
88
89 /*
90  * There are three quota SMP locks. dq_list_lock protects all lists with quotas
91  * and quota formats, dqstats structure containing statistics about the lists
92  * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
93  * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
94  * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
95  * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
96  * modifications of quota state (on quotaon and quotaoff) and readers who care
97  * about latest values take it as well.
98  *
99  * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
100  *   dq_list_lock > dq_state_lock
101  *
102  * Note that some things (eg. sb pointer, type, id) doesn't change during
103  * the life of the dquot structure and so needn't to be protected by a lock
104  *
105  * Any operation working on dquots via inode pointers must hold dqptr_sem.  If
106  * operation is just reading pointers from inode (or not using them at all) the
107  * read lock is enough. If pointers are altered function must hold write lock
108  * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
109  * for altering the flag i_mutex is also needed).
110  *
111  * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
112  * from inodes (dquot_alloc_space() and such don't check the dq_lock).
113  * Currently dquot is locked only when it is being read to memory (or space for
114  * it is being allocated) on the first dqget() and when it is being released on
115  * the last dqput(). The allocation and release oparations are serialized by
116  * the dq_lock and by checking the use count in dquot_release().  Write
117  * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
118  * spinlock to internal buffers before writing.
119  *
120  * Lock ordering (including related VFS locks) is the following:
121  *   i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
122  *   dqio_mutex
123  * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem >
124  * dqptr_sem. But filesystem has to count with the fact that functions such as
125  * dquot_alloc_space() acquire dqptr_sem and they usually have to be called
126  * from inside a transaction to keep filesystem consistency after a crash. Also
127  * filesystems usually want to do some IO on dquot from ->mark_dirty which is
128  * called with dqptr_sem held.
129  * i_mutex on quota files is special (it's below dqio_mutex)
130  */
131
132 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
133 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
134 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
135 EXPORT_SYMBOL(dq_data_lock);
136
137 static char *quotatypes[] = INITQFNAMES;
138 static struct quota_format_type *quota_formats; /* List of registered formats */
139 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
140
141 /* SLAB cache for dquot structures */
142 static struct kmem_cache *dquot_cachep;
143
144 int register_quota_format(struct quota_format_type *fmt)
145 {
146         spin_lock(&dq_list_lock);
147         fmt->qf_next = quota_formats;
148         quota_formats = fmt;
149         spin_unlock(&dq_list_lock);
150         return 0;
151 }
152 EXPORT_SYMBOL(register_quota_format);
153
154 void unregister_quota_format(struct quota_format_type *fmt)
155 {
156         struct quota_format_type **actqf;
157
158         spin_lock(&dq_list_lock);
159         for (actqf = &quota_formats; *actqf && *actqf != fmt;
160              actqf = &(*actqf)->qf_next)
161                 ;
162         if (*actqf)
163                 *actqf = (*actqf)->qf_next;
164         spin_unlock(&dq_list_lock);
165 }
166 EXPORT_SYMBOL(unregister_quota_format);
167
168 static struct quota_format_type *find_quota_format(int id)
169 {
170         struct quota_format_type *actqf;
171
172         spin_lock(&dq_list_lock);
173         for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
174              actqf = actqf->qf_next)
175                 ;
176         if (!actqf || !try_module_get(actqf->qf_owner)) {
177                 int qm;
178
179                 spin_unlock(&dq_list_lock);
180                 
181                 for (qm = 0; module_names[qm].qm_fmt_id &&
182                              module_names[qm].qm_fmt_id != id; qm++)
183                         ;
184                 if (!module_names[qm].qm_fmt_id ||
185                     request_module(module_names[qm].qm_mod_name))
186                         return NULL;
187
188                 spin_lock(&dq_list_lock);
189                 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
190                      actqf = actqf->qf_next)
191                         ;
192                 if (actqf && !try_module_get(actqf->qf_owner))
193                         actqf = NULL;
194         }
195         spin_unlock(&dq_list_lock);
196         return actqf;
197 }
198
199 static void put_quota_format(struct quota_format_type *fmt)
200 {
201         module_put(fmt->qf_owner);
202 }
203
204 /*
205  * Dquot List Management:
206  * The quota code uses three lists for dquot management: the inuse_list,
207  * free_dquots, and dquot_hash[] array. A single dquot structure may be
208  * on all three lists, depending on its current state.
209  *
210  * All dquots are placed to the end of inuse_list when first created, and this
211  * list is used for invalidate operation, which must look at every dquot.
212  *
213  * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
214  * and this list is searched whenever we need an available dquot.  Dquots are
215  * removed from the list as soon as they are used again, and
216  * dqstats.free_dquots gives the number of dquots on the list. When
217  * dquot is invalidated it's completely released from memory.
218  *
219  * Dquots with a specific identity (device, type and id) are placed on
220  * one of the dquot_hash[] hash chains. The provides an efficient search
221  * mechanism to locate a specific dquot.
222  */
223
224 static LIST_HEAD(inuse_list);
225 static LIST_HEAD(free_dquots);
226 static unsigned int dq_hash_bits, dq_hash_mask;
227 static struct hlist_head *dquot_hash;
228
229 struct dqstats dqstats;
230 EXPORT_SYMBOL(dqstats);
231
232 static inline unsigned int
233 hashfn(const struct super_block *sb, unsigned int id, int type)
234 {
235         unsigned long tmp;
236
237         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
238         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
239 }
240
241 /*
242  * Following list functions expect dq_list_lock to be held
243  */
244 static inline void insert_dquot_hash(struct dquot *dquot)
245 {
246         struct hlist_head *head;
247         head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
248         hlist_add_head(&dquot->dq_hash, head);
249 }
250
251 static inline void remove_dquot_hash(struct dquot *dquot)
252 {
253         hlist_del_init(&dquot->dq_hash);
254 }
255
256 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
257                                 unsigned int id, int type)
258 {
259         struct hlist_node *node;
260         struct dquot *dquot;
261
262         hlist_for_each (node, dquot_hash+hashent) {
263                 dquot = hlist_entry(node, struct dquot, dq_hash);
264                 if (dquot->dq_sb == sb && dquot->dq_id == id &&
265                     dquot->dq_type == type)
266                         return dquot;
267         }
268         return NULL;
269 }
270
271 /* Add a dquot to the tail of the free list */
272 static inline void put_dquot_last(struct dquot *dquot)
273 {
274         list_add_tail(&dquot->dq_free, &free_dquots);
275         dqstats.free_dquots++;
276 }
277
278 static inline void remove_free_dquot(struct dquot *dquot)
279 {
280         if (list_empty(&dquot->dq_free))
281                 return;
282         list_del_init(&dquot->dq_free);
283         dqstats.free_dquots--;
284 }
285
286 static inline void put_inuse(struct dquot *dquot)
287 {
288         /* We add to the back of inuse list so we don't have to restart
289          * when traversing this list and we block */
290         list_add_tail(&dquot->dq_inuse, &inuse_list);
291         dqstats.allocated_dquots++;
292 }
293
294 static inline void remove_inuse(struct dquot *dquot)
295 {
296         dqstats.allocated_dquots--;
297         list_del(&dquot->dq_inuse);
298 }
299 /*
300  * End of list functions needing dq_list_lock
301  */
302
303 static void wait_on_dquot(struct dquot *dquot)
304 {
305         mutex_lock(&dquot->dq_lock);
306         mutex_unlock(&dquot->dq_lock);
307 }
308
309 static inline int dquot_dirty(struct dquot *dquot)
310 {
311         return test_bit(DQ_MOD_B, &dquot->dq_flags);
312 }
313
314 static inline int mark_dquot_dirty(struct dquot *dquot)
315 {
316         return dquot->dq_sb->dq_op->mark_dirty(dquot);
317 }
318
319 int dquot_mark_dquot_dirty(struct dquot *dquot)
320 {
321         spin_lock(&dq_list_lock);
322         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
323                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
324                                 info[dquot->dq_type].dqi_dirty_list);
325         spin_unlock(&dq_list_lock);
326         return 0;
327 }
328 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
329
330 /* This function needs dq_list_lock */
331 static inline int clear_dquot_dirty(struct dquot *dquot)
332 {
333         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
334                 return 0;
335         list_del_init(&dquot->dq_dirty);
336         return 1;
337 }
338
339 void mark_info_dirty(struct super_block *sb, int type)
340 {
341         set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
342 }
343 EXPORT_SYMBOL(mark_info_dirty);
344
345 /*
346  *      Read dquot from disk and alloc space for it
347  */
348
349 int dquot_acquire(struct dquot *dquot)
350 {
351         int ret = 0, ret2 = 0;
352         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
353
354         mutex_lock(&dquot->dq_lock);
355         mutex_lock(&dqopt->dqio_mutex);
356         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
357                 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
358         if (ret < 0)
359                 goto out_iolock;
360         set_bit(DQ_READ_B, &dquot->dq_flags);
361         /* Instantiate dquot if needed */
362         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
363                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
364                 /* Write the info if needed */
365                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
366                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
367                                                 dquot->dq_sb, dquot->dq_type);
368                 }
369                 if (ret < 0)
370                         goto out_iolock;
371                 if (ret2 < 0) {
372                         ret = ret2;
373                         goto out_iolock;
374                 }
375         }
376         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
377 out_iolock:
378         mutex_unlock(&dqopt->dqio_mutex);
379         mutex_unlock(&dquot->dq_lock);
380         return ret;
381 }
382 EXPORT_SYMBOL(dquot_acquire);
383
384 /*
385  *      Write dquot to disk
386  */
387 int dquot_commit(struct dquot *dquot)
388 {
389         int ret = 0, ret2 = 0;
390         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
391
392         mutex_lock(&dqopt->dqio_mutex);
393         spin_lock(&dq_list_lock);
394         if (!clear_dquot_dirty(dquot)) {
395                 spin_unlock(&dq_list_lock);
396                 goto out_sem;
397         }
398         spin_unlock(&dq_list_lock);
399         /* Inactive dquot can be only if there was error during read/init
400          * => we have better not writing it */
401         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
402                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
403                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
404                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
405                                                 dquot->dq_sb, dquot->dq_type);
406                 }
407                 if (ret >= 0)
408                         ret = ret2;
409         }
410 out_sem:
411         mutex_unlock(&dqopt->dqio_mutex);
412         return ret;
413 }
414 EXPORT_SYMBOL(dquot_commit);
415
416 /*
417  *      Release dquot
418  */
419 int dquot_release(struct dquot *dquot)
420 {
421         int ret = 0, ret2 = 0;
422         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
423
424         mutex_lock(&dquot->dq_lock);
425         /* Check whether we are not racing with some other dqget() */
426         if (atomic_read(&dquot->dq_count) > 1)
427                 goto out_dqlock;
428         mutex_lock(&dqopt->dqio_mutex);
429         if (dqopt->ops[dquot->dq_type]->release_dqblk) {
430                 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
431                 /* Write the info */
432                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
433                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
434                                                 dquot->dq_sb, dquot->dq_type);
435                 }
436                 if (ret >= 0)
437                         ret = ret2;
438         }
439         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
440         mutex_unlock(&dqopt->dqio_mutex);
441 out_dqlock:
442         mutex_unlock(&dquot->dq_lock);
443         return ret;
444 }
445 EXPORT_SYMBOL(dquot_release);
446
447 void dquot_destroy(struct dquot *dquot)
448 {
449         kmem_cache_free(dquot_cachep, dquot);
450 }
451 EXPORT_SYMBOL(dquot_destroy);
452
453 static inline void do_destroy_dquot(struct dquot *dquot)
454 {
455         dquot->dq_sb->dq_op->destroy_dquot(dquot);
456 }
457
458 /* Invalidate all dquots on the list. Note that this function is called after
459  * quota is disabled and pointers from inodes removed so there cannot be new
460  * quota users. There can still be some users of quotas due to inodes being
461  * just deleted or pruned by prune_icache() (those are not attached to any
462  * list) or parallel quotactl call. We have to wait for such users.
463  */
464 static void invalidate_dquots(struct super_block *sb, int type)
465 {
466         struct dquot *dquot, *tmp;
467
468 restart:
469         spin_lock(&dq_list_lock);
470         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
471                 if (dquot->dq_sb != sb)
472                         continue;
473                 if (dquot->dq_type != type)
474                         continue;
475                 /* Wait for dquot users */
476                 if (atomic_read(&dquot->dq_count)) {
477                         DEFINE_WAIT(wait);
478
479                         atomic_inc(&dquot->dq_count);
480                         prepare_to_wait(&dquot->dq_wait_unused, &wait,
481                                         TASK_UNINTERRUPTIBLE);
482                         spin_unlock(&dq_list_lock);
483                         /* Once dqput() wakes us up, we know it's time to free
484                          * the dquot.
485                          * IMPORTANT: we rely on the fact that there is always
486                          * at most one process waiting for dquot to free.
487                          * Otherwise dq_count would be > 1 and we would never
488                          * wake up.
489                          */
490                         if (atomic_read(&dquot->dq_count) > 1)
491                                 schedule();
492                         finish_wait(&dquot->dq_wait_unused, &wait);
493                         dqput(dquot);
494                         /* At this moment dquot() need not exist (it could be
495                          * reclaimed by prune_dqcache(). Hence we must
496                          * restart. */
497                         goto restart;
498                 }
499                 /*
500                  * Quota now has no users and it has been written on last
501                  * dqput()
502                  */
503                 remove_dquot_hash(dquot);
504                 remove_free_dquot(dquot);
505                 remove_inuse(dquot);
506                 do_destroy_dquot(dquot);
507         }
508         spin_unlock(&dq_list_lock);
509 }
510
511 /* Call callback for every active dquot on given filesystem */
512 int dquot_scan_active(struct super_block *sb,
513                       int (*fn)(struct dquot *dquot, unsigned long priv),
514                       unsigned long priv)
515 {
516         struct dquot *dquot, *old_dquot = NULL;
517         int ret = 0;
518
519         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
520         spin_lock(&dq_list_lock);
521         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
522                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
523                         continue;
524                 if (dquot->dq_sb != sb)
525                         continue;
526                 /* Now we have active dquot so we can just increase use count */
527                 atomic_inc(&dquot->dq_count);
528                 dqstats.lookups++;
529                 spin_unlock(&dq_list_lock);
530                 dqput(old_dquot);
531                 old_dquot = dquot;
532                 ret = fn(dquot, priv);
533                 if (ret < 0)
534                         goto out;
535                 spin_lock(&dq_list_lock);
536                 /* We are safe to continue now because our dquot could not
537                  * be moved out of the inuse list while we hold the reference */
538         }
539         spin_unlock(&dq_list_lock);
540 out:
541         dqput(old_dquot);
542         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
543         return ret;
544 }
545 EXPORT_SYMBOL(dquot_scan_active);
546
547 int vfs_quota_sync(struct super_block *sb, int type)
548 {
549         struct list_head *dirty;
550         struct dquot *dquot;
551         struct quota_info *dqopt = sb_dqopt(sb);
552         int cnt;
553
554         mutex_lock(&dqopt->dqonoff_mutex);
555         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
556                 if (type != -1 && cnt != type)
557                         continue;
558                 if (!sb_has_quota_active(sb, cnt))
559                         continue;
560                 spin_lock(&dq_list_lock);
561                 dirty = &dqopt->info[cnt].dqi_dirty_list;
562                 while (!list_empty(dirty)) {
563                         dquot = list_first_entry(dirty, struct dquot,
564                                                  dq_dirty);
565                         /* Dirty and inactive can be only bad dquot... */
566                         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
567                                 clear_dquot_dirty(dquot);
568                                 continue;
569                         }
570                         /* Now we have active dquot from which someone is
571                          * holding reference so we can safely just increase
572                          * use count */
573                         atomic_inc(&dquot->dq_count);
574                         dqstats.lookups++;
575                         spin_unlock(&dq_list_lock);
576                         sb->dq_op->write_dquot(dquot);
577                         dqput(dquot);
578                         spin_lock(&dq_list_lock);
579                 }
580                 spin_unlock(&dq_list_lock);
581         }
582
583         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
584                 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
585                     && info_dirty(&dqopt->info[cnt]))
586                         sb->dq_op->write_info(sb, cnt);
587         spin_lock(&dq_list_lock);
588         dqstats.syncs++;
589         spin_unlock(&dq_list_lock);
590         mutex_unlock(&dqopt->dqonoff_mutex);
591
592         return 0;
593 }
594 EXPORT_SYMBOL(vfs_quota_sync);
595
596 /* Free unused dquots from cache */
597 static void prune_dqcache(int count)
598 {
599         struct list_head *head;
600         struct dquot *dquot;
601
602         head = free_dquots.prev;
603         while (head != &free_dquots && count) {
604                 dquot = list_entry(head, struct dquot, dq_free);
605                 remove_dquot_hash(dquot);
606                 remove_free_dquot(dquot);
607                 remove_inuse(dquot);
608                 do_destroy_dquot(dquot);
609                 count--;
610                 head = free_dquots.prev;
611         }
612 }
613
614 /*
615  * This is called from kswapd when we think we need some
616  * more memory
617  */
618
619 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
620 {
621         if (nr) {
622                 spin_lock(&dq_list_lock);
623                 prune_dqcache(nr);
624                 spin_unlock(&dq_list_lock);
625         }
626         return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
627 }
628
629 static struct shrinker dqcache_shrinker = {
630         .shrink = shrink_dqcache_memory,
631         .seeks = DEFAULT_SEEKS,
632 };
633
634 /*
635  * Put reference to dquot
636  * NOTE: If you change this function please check whether dqput_blocks() works right...
637  */
638 void dqput(struct dquot *dquot)
639 {
640         int ret;
641
642         if (!dquot)
643                 return;
644 #ifdef __DQUOT_PARANOIA
645         if (!atomic_read(&dquot->dq_count)) {
646                 printk("VFS: dqput: trying to free free dquot\n");
647                 printk("VFS: device %s, dquot of %s %d\n",
648                         dquot->dq_sb->s_id,
649                         quotatypes[dquot->dq_type],
650                         dquot->dq_id);
651                 BUG();
652         }
653 #endif
654         
655         spin_lock(&dq_list_lock);
656         dqstats.drops++;
657         spin_unlock(&dq_list_lock);
658 we_slept:
659         spin_lock(&dq_list_lock);
660         if (atomic_read(&dquot->dq_count) > 1) {
661                 /* We have more than one user... nothing to do */
662                 atomic_dec(&dquot->dq_count);
663                 /* Releasing dquot during quotaoff phase? */
664                 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
665                     atomic_read(&dquot->dq_count) == 1)
666                         wake_up(&dquot->dq_wait_unused);
667                 spin_unlock(&dq_list_lock);
668                 return;
669         }
670         /* Need to release dquot? */
671         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
672                 spin_unlock(&dq_list_lock);
673                 /* Commit dquot before releasing */
674                 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
675                 if (ret < 0) {
676                         printk(KERN_ERR "VFS: cannot write quota structure on "
677                                 "device %s (error %d). Quota may get out of "
678                                 "sync!\n", dquot->dq_sb->s_id, ret);
679                         /*
680                          * We clear dirty bit anyway, so that we avoid
681                          * infinite loop here
682                          */
683                         spin_lock(&dq_list_lock);
684                         clear_dquot_dirty(dquot);
685                         spin_unlock(&dq_list_lock);
686                 }
687                 goto we_slept;
688         }
689         /* Clear flag in case dquot was inactive (something bad happened) */
690         clear_dquot_dirty(dquot);
691         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
692                 spin_unlock(&dq_list_lock);
693                 dquot->dq_sb->dq_op->release_dquot(dquot);
694                 goto we_slept;
695         }
696         atomic_dec(&dquot->dq_count);
697 #ifdef __DQUOT_PARANOIA
698         /* sanity check */
699         BUG_ON(!list_empty(&dquot->dq_free));
700 #endif
701         put_dquot_last(dquot);
702         spin_unlock(&dq_list_lock);
703 }
704 EXPORT_SYMBOL(dqput);
705
706 struct dquot *dquot_alloc(struct super_block *sb, int type)
707 {
708         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
709 }
710 EXPORT_SYMBOL(dquot_alloc);
711
712 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
713 {
714         struct dquot *dquot;
715
716         dquot = sb->dq_op->alloc_dquot(sb, type);
717         if(!dquot)
718                 return NULL;
719
720         mutex_init(&dquot->dq_lock);
721         INIT_LIST_HEAD(&dquot->dq_free);
722         INIT_LIST_HEAD(&dquot->dq_inuse);
723         INIT_HLIST_NODE(&dquot->dq_hash);
724         INIT_LIST_HEAD(&dquot->dq_dirty);
725         init_waitqueue_head(&dquot->dq_wait_unused);
726         dquot->dq_sb = sb;
727         dquot->dq_type = type;
728         atomic_set(&dquot->dq_count, 1);
729
730         return dquot;
731 }
732
733 /*
734  * Get reference to dquot
735  *
736  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
737  * destroying our dquot by:
738  *   a) checking for quota flags under dq_list_lock and
739  *   b) getting a reference to dquot before we release dq_list_lock
740  */
741 struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
742 {
743         unsigned int hashent = hashfn(sb, id, type);
744         struct dquot *dquot = NULL, *empty = NULL;
745
746         if (!sb_has_quota_active(sb, type))
747                 return NULL;
748 we_slept:
749         spin_lock(&dq_list_lock);
750         spin_lock(&dq_state_lock);
751         if (!sb_has_quota_active(sb, type)) {
752                 spin_unlock(&dq_state_lock);
753                 spin_unlock(&dq_list_lock);
754                 goto out;
755         }
756         spin_unlock(&dq_state_lock);
757
758         dquot = find_dquot(hashent, sb, id, type);
759         if (!dquot) {
760                 if (!empty) {
761                         spin_unlock(&dq_list_lock);
762                         empty = get_empty_dquot(sb, type);
763                         if (!empty)
764                                 schedule();     /* Try to wait for a moment... */
765                         goto we_slept;
766                 }
767                 dquot = empty;
768                 empty = NULL;
769                 dquot->dq_id = id;
770                 /* all dquots go on the inuse_list */
771                 put_inuse(dquot);
772                 /* hash it first so it can be found */
773                 insert_dquot_hash(dquot);
774                 dqstats.lookups++;
775                 spin_unlock(&dq_list_lock);
776         } else {
777                 if (!atomic_read(&dquot->dq_count))
778                         remove_free_dquot(dquot);
779                 atomic_inc(&dquot->dq_count);
780                 dqstats.cache_hits++;
781                 dqstats.lookups++;
782                 spin_unlock(&dq_list_lock);
783         }
784         /* Wait for dq_lock - after this we know that either dquot_release() is
785          * already finished or it will be canceled due to dq_count > 1 test */
786         wait_on_dquot(dquot);
787         /* Read the dquot / allocate space in quota file */
788         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) &&
789             sb->dq_op->acquire_dquot(dquot) < 0) {
790                 dqput(dquot);
791                 dquot = NULL;
792                 goto out;
793         }
794 #ifdef __DQUOT_PARANOIA
795         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
796 #endif
797 out:
798         if (empty)
799                 do_destroy_dquot(empty);
800
801         return dquot;
802 }
803 EXPORT_SYMBOL(dqget);
804
805 static int dqinit_needed(struct inode *inode, int type)
806 {
807         int cnt;
808
809         if (IS_NOQUOTA(inode))
810                 return 0;
811         if (type != -1)
812                 return !inode->i_dquot[type];
813         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
814                 if (!inode->i_dquot[cnt])
815                         return 1;
816         return 0;
817 }
818
819 /* This routine is guarded by dqonoff_mutex mutex */
820 static void add_dquot_ref(struct super_block *sb, int type)
821 {
822         struct inode *inode, *old_inode = NULL;
823
824         spin_lock(&inode_lock);
825         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
826                 if (!atomic_read(&inode->i_writecount))
827                         continue;
828                 if (!dqinit_needed(inode, type))
829                         continue;
830                 if (inode->i_state & (I_FREEING|I_WILL_FREE))
831                         continue;
832
833                 __iget(inode);
834                 spin_unlock(&inode_lock);
835
836                 iput(old_inode);
837                 sb->dq_op->initialize(inode, type);
838                 /* We hold a reference to 'inode' so it couldn't have been
839                  * removed from s_inodes list while we dropped the inode_lock.
840                  * We cannot iput the inode now as we can be holding the last
841                  * reference and we cannot iput it under inode_lock. So we
842                  * keep the reference and iput it later. */
843                 old_inode = inode;
844                 spin_lock(&inode_lock);
845         }
846         spin_unlock(&inode_lock);
847         iput(old_inode);
848 }
849
850 /*
851  * Return 0 if dqput() won't block.
852  * (note that 1 doesn't necessarily mean blocking)
853  */
854 static inline int dqput_blocks(struct dquot *dquot)
855 {
856         if (atomic_read(&dquot->dq_count) <= 1)
857                 return 1;
858         return 0;
859 }
860
861 /*
862  * Remove references to dquots from inode and add dquot to list for freeing
863  * if we have the last referece to dquot
864  * We can't race with anybody because we hold dqptr_sem for writing...
865  */
866 static int remove_inode_dquot_ref(struct inode *inode, int type,
867                                   struct list_head *tofree_head)
868 {
869         struct dquot *dquot = inode->i_dquot[type];
870
871         inode->i_dquot[type] = NULL;
872         if (dquot) {
873                 if (dqput_blocks(dquot)) {
874 #ifdef __DQUOT_PARANOIA
875                         if (atomic_read(&dquot->dq_count) != 1)
876                                 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
877 #endif
878                         spin_lock(&dq_list_lock);
879                         /* As dquot must have currently users it can't be on
880                          * the free list... */
881                         list_add(&dquot->dq_free, tofree_head);
882                         spin_unlock(&dq_list_lock);
883                         return 1;
884                 }
885                 else
886                         dqput(dquot);   /* We have guaranteed we won't block */
887         }
888         return 0;
889 }
890
891 /*
892  * Free list of dquots
893  * Dquots are removed from inodes and no new references can be got so we are
894  * the only ones holding reference
895  */
896 static void put_dquot_list(struct list_head *tofree_head)
897 {
898         struct list_head *act_head;
899         struct dquot *dquot;
900
901         act_head = tofree_head->next;
902         while (act_head != tofree_head) {
903                 dquot = list_entry(act_head, struct dquot, dq_free);
904                 act_head = act_head->next;
905                 /* Remove dquot from the list so we won't have problems... */
906                 list_del_init(&dquot->dq_free);
907                 dqput(dquot);
908         }
909 }
910
911 static void remove_dquot_ref(struct super_block *sb, int type,
912                 struct list_head *tofree_head)
913 {
914         struct inode *inode;
915
916         spin_lock(&inode_lock);
917         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
918                 if (!IS_NOQUOTA(inode))
919                         remove_inode_dquot_ref(inode, type, tofree_head);
920         }
921         spin_unlock(&inode_lock);
922 }
923
924 /* Gather all references from inodes and drop them */
925 static void drop_dquot_ref(struct super_block *sb, int type)
926 {
927         LIST_HEAD(tofree_head);
928
929         if (sb->dq_op) {
930                 down_write(&sb_dqopt(sb)->dqptr_sem);
931                 remove_dquot_ref(sb, type, &tofree_head);
932                 up_write(&sb_dqopt(sb)->dqptr_sem);
933                 put_dquot_list(&tofree_head);
934         }
935 }
936
937 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
938 {
939         dquot->dq_dqb.dqb_curinodes += number;
940 }
941
942 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
943 {
944         dquot->dq_dqb.dqb_curspace += number;
945 }
946
947 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
948 {
949         dquot->dq_dqb.dqb_rsvspace += number;
950 }
951
952 /*
953  * Claim reserved quota space
954  */
955 static void dquot_claim_reserved_space(struct dquot *dquot,
956                                                 qsize_t number)
957 {
958         WARN_ON(dquot->dq_dqb.dqb_rsvspace < number);
959         dquot->dq_dqb.dqb_curspace += number;
960         dquot->dq_dqb.dqb_rsvspace -= number;
961 }
962
963 static inline
964 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
965 {
966         dquot->dq_dqb.dqb_rsvspace -= number;
967 }
968
969 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
970 {
971         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
972             dquot->dq_dqb.dqb_curinodes >= number)
973                 dquot->dq_dqb.dqb_curinodes -= number;
974         else
975                 dquot->dq_dqb.dqb_curinodes = 0;
976         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
977                 dquot->dq_dqb.dqb_itime = (time_t) 0;
978         clear_bit(DQ_INODES_B, &dquot->dq_flags);
979 }
980
981 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
982 {
983         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
984             dquot->dq_dqb.dqb_curspace >= number)
985                 dquot->dq_dqb.dqb_curspace -= number;
986         else
987                 dquot->dq_dqb.dqb_curspace = 0;
988         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
989                 dquot->dq_dqb.dqb_btime = (time_t) 0;
990         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
991 }
992
993 static int warning_issued(struct dquot *dquot, const int warntype)
994 {
995         int flag = (warntype == QUOTA_NL_BHARDWARN ||
996                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
997                 ((warntype == QUOTA_NL_IHARDWARN ||
998                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
999
1000         if (!flag)
1001                 return 0;
1002         return test_and_set_bit(flag, &dquot->dq_flags);
1003 }
1004
1005 #ifdef CONFIG_PRINT_QUOTA_WARNING
1006 static int flag_print_warnings = 1;
1007
1008 static int need_print_warning(struct dquot *dquot)
1009 {
1010         if (!flag_print_warnings)
1011                 return 0;
1012
1013         switch (dquot->dq_type) {
1014                 case USRQUOTA:
1015                         return current_fsuid() == dquot->dq_id;
1016                 case GRPQUOTA:
1017                         return in_group_p(dquot->dq_id);
1018         }
1019         return 0;
1020 }
1021
1022 /* Print warning to user which exceeded quota */
1023 static void print_warning(struct dquot *dquot, const int warntype)
1024 {
1025         char *msg = NULL;
1026         struct tty_struct *tty;
1027
1028         if (warntype == QUOTA_NL_IHARDBELOW ||
1029             warntype == QUOTA_NL_ISOFTBELOW ||
1030             warntype == QUOTA_NL_BHARDBELOW ||
1031             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
1032                 return;
1033
1034         tty = get_current_tty();
1035         if (!tty)
1036                 return;
1037         tty_write_message(tty, dquot->dq_sb->s_id);
1038         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1039                 tty_write_message(tty, ": warning, ");
1040         else
1041                 tty_write_message(tty, ": write failed, ");
1042         tty_write_message(tty, quotatypes[dquot->dq_type]);
1043         switch (warntype) {
1044                 case QUOTA_NL_IHARDWARN:
1045                         msg = " file limit reached.\r\n";
1046                         break;
1047                 case QUOTA_NL_ISOFTLONGWARN:
1048                         msg = " file quota exceeded too long.\r\n";
1049                         break;
1050                 case QUOTA_NL_ISOFTWARN:
1051                         msg = " file quota exceeded.\r\n";
1052                         break;
1053                 case QUOTA_NL_BHARDWARN:
1054                         msg = " block limit reached.\r\n";
1055                         break;
1056                 case QUOTA_NL_BSOFTLONGWARN:
1057                         msg = " block quota exceeded too long.\r\n";
1058                         break;
1059                 case QUOTA_NL_BSOFTWARN:
1060                         msg = " block quota exceeded.\r\n";
1061                         break;
1062         }
1063         tty_write_message(tty, msg);
1064         tty_kref_put(tty);
1065 }
1066 #endif
1067
1068 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1069
1070 /* Netlink family structure for quota */
1071 static struct genl_family quota_genl_family = {
1072         .id = GENL_ID_GENERATE,
1073         .hdrsize = 0,
1074         .name = "VFS_DQUOT",
1075         .version = 1,
1076         .maxattr = QUOTA_NL_A_MAX,
1077 };
1078
1079 /* Send warning to userspace about user which exceeded quota */
1080 static void send_warning(const struct dquot *dquot, const char warntype)
1081 {
1082         static atomic_t seq;
1083         struct sk_buff *skb;
1084         void *msg_head;
1085         int ret;
1086         int msg_size = 4 * nla_total_size(sizeof(u32)) +
1087                        2 * nla_total_size(sizeof(u64));
1088
1089         /* We have to allocate using GFP_NOFS as we are called from a
1090          * filesystem performing write and thus further recursion into
1091          * the fs to free some data could cause deadlocks. */
1092         skb = genlmsg_new(msg_size, GFP_NOFS);
1093         if (!skb) {
1094                 printk(KERN_ERR
1095                   "VFS: Not enough memory to send quota warning.\n");
1096                 return;
1097         }
1098         msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
1099                         &quota_genl_family, 0, QUOTA_NL_C_WARNING);
1100         if (!msg_head) {
1101                 printk(KERN_ERR
1102                   "VFS: Cannot store netlink header in quota warning.\n");
1103                 goto err_out;
1104         }
1105         ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type);
1106         if (ret)
1107                 goto attr_err_out;
1108         ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id);
1109         if (ret)
1110                 goto attr_err_out;
1111         ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
1112         if (ret)
1113                 goto attr_err_out;
1114         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR,
1115                 MAJOR(dquot->dq_sb->s_dev));
1116         if (ret)
1117                 goto attr_err_out;
1118         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR,
1119                 MINOR(dquot->dq_sb->s_dev));
1120         if (ret)
1121                 goto attr_err_out;
1122         ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
1123         if (ret)
1124                 goto attr_err_out;
1125         genlmsg_end(skb, msg_head);
1126
1127         ret = genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
1128         if (ret < 0 && ret != -ESRCH)
1129                 printk(KERN_ERR
1130                         "VFS: Failed to send notification message: %d\n", ret);
1131         return;
1132 attr_err_out:
1133         printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
1134 err_out:
1135         kfree_skb(skb);
1136 }
1137 #endif
1138 /*
1139  * Write warnings to the console and send warning messages over netlink.
1140  *
1141  * Note that this function can sleep.
1142  */
1143 static void flush_warnings(struct dquot *const *dquots, char *warntype)
1144 {
1145         int i;
1146
1147         for (i = 0; i < MAXQUOTAS; i++)
1148                 if (dquots[i] && warntype[i] != QUOTA_NL_NOWARN &&
1149                     !warning_issued(dquots[i], warntype[i])) {
1150 #ifdef CONFIG_PRINT_QUOTA_WARNING
1151                         print_warning(dquots[i], warntype[i]);
1152 #endif
1153 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1154                         send_warning(dquots[i], warntype[i]);
1155 #endif
1156                 }
1157 }
1158
1159 static int ignore_hardlimit(struct dquot *dquot)
1160 {
1161         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1162
1163         return capable(CAP_SYS_RESOURCE) &&
1164                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1165                 !(info->dqi_flags & V1_DQF_RSQUASH));
1166 }
1167
1168 /* needs dq_data_lock */
1169 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
1170 {
1171         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1172
1173         *warntype = QUOTA_NL_NOWARN;
1174         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1175             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1176                 return QUOTA_OK;
1177
1178         if (dquot->dq_dqb.dqb_ihardlimit &&
1179             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1180             !ignore_hardlimit(dquot)) {
1181                 *warntype = QUOTA_NL_IHARDWARN;
1182                 return NO_QUOTA;
1183         }
1184
1185         if (dquot->dq_dqb.dqb_isoftlimit &&
1186             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1187             dquot->dq_dqb.dqb_itime &&
1188             get_seconds() >= dquot->dq_dqb.dqb_itime &&
1189             !ignore_hardlimit(dquot)) {
1190                 *warntype = QUOTA_NL_ISOFTLONGWARN;
1191                 return NO_QUOTA;
1192         }
1193
1194         if (dquot->dq_dqb.dqb_isoftlimit &&
1195             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1196             dquot->dq_dqb.dqb_itime == 0) {
1197                 *warntype = QUOTA_NL_ISOFTWARN;
1198                 dquot->dq_dqb.dqb_itime = get_seconds() +
1199                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1200         }
1201
1202         return QUOTA_OK;
1203 }
1204
1205 /* needs dq_data_lock */
1206 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1207 {
1208         qsize_t tspace;
1209         struct super_block *sb = dquot->dq_sb;
1210
1211         *warntype = QUOTA_NL_NOWARN;
1212         if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
1213             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1214                 return QUOTA_OK;
1215
1216         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1217                 + space;
1218
1219         if (dquot->dq_dqb.dqb_bhardlimit &&
1220             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1221             !ignore_hardlimit(dquot)) {
1222                 if (!prealloc)
1223                         *warntype = QUOTA_NL_BHARDWARN;
1224                 return NO_QUOTA;
1225         }
1226
1227         if (dquot->dq_dqb.dqb_bsoftlimit &&
1228             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1229             dquot->dq_dqb.dqb_btime &&
1230             get_seconds() >= dquot->dq_dqb.dqb_btime &&
1231             !ignore_hardlimit(dquot)) {
1232                 if (!prealloc)
1233                         *warntype = QUOTA_NL_BSOFTLONGWARN;
1234                 return NO_QUOTA;
1235         }
1236
1237         if (dquot->dq_dqb.dqb_bsoftlimit &&
1238             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1239             dquot->dq_dqb.dqb_btime == 0) {
1240                 if (!prealloc) {
1241                         *warntype = QUOTA_NL_BSOFTWARN;
1242                         dquot->dq_dqb.dqb_btime = get_seconds() +
1243                             sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
1244                 }
1245                 else
1246                         /*
1247                          * We don't allow preallocation to exceed softlimit so exceeding will
1248                          * be always printed
1249                          */
1250                         return NO_QUOTA;
1251         }
1252
1253         return QUOTA_OK;
1254 }
1255
1256 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1257 {
1258         qsize_t newinodes;
1259
1260         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1261             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1262             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
1263                 return QUOTA_NL_NOWARN;
1264
1265         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1266         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1267                 return QUOTA_NL_ISOFTBELOW;
1268         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1269             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1270                 return QUOTA_NL_IHARDBELOW;
1271         return QUOTA_NL_NOWARN;
1272 }
1273
1274 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1275 {
1276         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1277             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1278                 return QUOTA_NL_NOWARN;
1279
1280         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1281                 return QUOTA_NL_BSOFTBELOW;
1282         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1283             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1284                 return QUOTA_NL_BHARDBELOW;
1285         return QUOTA_NL_NOWARN;
1286 }
1287 /*
1288  *      Initialize quota pointers in inode
1289  *      We do things in a bit complicated way but by that we avoid calling
1290  *      dqget() and thus filesystem callbacks under dqptr_sem.
1291  */
1292 int dquot_initialize(struct inode *inode, int type)
1293 {
1294         unsigned int id = 0;
1295         int cnt, ret = 0;
1296         struct dquot *got[MAXQUOTAS] = { NULL, NULL };
1297         struct super_block *sb = inode->i_sb;
1298
1299         /* First test before acquiring mutex - solves deadlocks when we
1300          * re-enter the quota code and are already holding the mutex */
1301         if (IS_NOQUOTA(inode))
1302                 return 0;
1303
1304         /* First get references to structures we might need. */
1305         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1306                 if (type != -1 && cnt != type)
1307                         continue;
1308                 switch (cnt) {
1309                 case USRQUOTA:
1310                         id = inode->i_uid;
1311                         break;
1312                 case GRPQUOTA:
1313                         id = inode->i_gid;
1314                         break;
1315                 }
1316                 got[cnt] = dqget(sb, id, cnt);
1317         }
1318
1319         down_write(&sb_dqopt(sb)->dqptr_sem);
1320         /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
1321         if (IS_NOQUOTA(inode))
1322                 goto out_err;
1323         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1324                 if (type != -1 && cnt != type)
1325                         continue;
1326                 /* Avoid races with quotaoff() */
1327                 if (!sb_has_quota_active(sb, cnt))
1328                         continue;
1329                 if (!inode->i_dquot[cnt]) {
1330                         inode->i_dquot[cnt] = got[cnt];
1331                         got[cnt] = NULL;
1332                 }
1333         }
1334 out_err:
1335         up_write(&sb_dqopt(sb)->dqptr_sem);
1336         /* Drop unused references */
1337         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1338                 dqput(got[cnt]);
1339         return ret;
1340 }
1341 EXPORT_SYMBOL(dquot_initialize);
1342
1343 /*
1344  *      Release all quotas referenced by inode
1345  */
1346 int dquot_drop(struct inode *inode)
1347 {
1348         int cnt;
1349         struct dquot *put[MAXQUOTAS];
1350
1351         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1352         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1353                 put[cnt] = inode->i_dquot[cnt];
1354                 inode->i_dquot[cnt] = NULL;
1355         }
1356         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1357
1358         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1359                 dqput(put[cnt]);
1360         return 0;
1361 }
1362 EXPORT_SYMBOL(dquot_drop);
1363
1364 /* Wrapper to remove references to quota structures from inode */
1365 void vfs_dq_drop(struct inode *inode)
1366 {
1367         /* Here we can get arbitrary inode from clear_inode() so we have
1368          * to be careful. OTOH we don't need locking as quota operations
1369          * are allowed to change only at mount time */
1370         if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op
1371             && inode->i_sb->dq_op->drop) {
1372                 int cnt;
1373                 /* Test before calling to rule out calls from proc and such
1374                  * where we are not allowed to block. Note that this is
1375                  * actually reliable test even without the lock - the caller
1376                  * must assure that nobody can come after the DQUOT_DROP and
1377                  * add quota pointers back anyway */
1378                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1379                         if (inode->i_dquot[cnt])
1380                                 break;
1381                 if (cnt < MAXQUOTAS)
1382                         inode->i_sb->dq_op->drop(inode);
1383         }
1384 }
1385 EXPORT_SYMBOL(vfs_dq_drop);
1386
1387 /*
1388  * Following four functions update i_blocks+i_bytes fields and
1389  * quota information (together with appropriate checks)
1390  * NOTE: We absolutely rely on the fact that caller dirties
1391  * the inode (usually macros in quotaops.h care about this) and
1392  * holds a handle for the current transaction so that dquot write and
1393  * inode write go into the same transaction.
1394  */
1395
1396 /*
1397  * This operation can block, but only after everything is updated
1398  */
1399 int __dquot_alloc_space(struct inode *inode, qsize_t number,
1400                         int warn, int reserve)
1401 {
1402         int cnt, ret = QUOTA_OK;
1403         char warntype[MAXQUOTAS];
1404
1405         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1406                 warntype[cnt] = QUOTA_NL_NOWARN;
1407
1408         spin_lock(&dq_data_lock);
1409         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1410                 if (!inode->i_dquot[cnt])
1411                         continue;
1412                 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt)
1413                     == NO_QUOTA) {
1414                         ret = NO_QUOTA;
1415                         goto out_unlock;
1416                 }
1417         }
1418         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1419                 if (!inode->i_dquot[cnt])
1420                         continue;
1421                 if (reserve)
1422                         dquot_resv_space(inode->i_dquot[cnt], number);
1423                 else
1424                         dquot_incr_space(inode->i_dquot[cnt], number);
1425         }
1426         if (!reserve)
1427                 inode_add_bytes(inode, number);
1428 out_unlock:
1429         spin_unlock(&dq_data_lock);
1430         flush_warnings(inode->i_dquot, warntype);
1431         return ret;
1432 }
1433
1434 int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1435 {
1436         int cnt, ret = QUOTA_OK;
1437
1438         /*
1439          * First test before acquiring mutex - solves deadlocks when we
1440          * re-enter the quota code and are already holding the mutex
1441          */
1442         if (IS_NOQUOTA(inode)) {
1443                 inode_add_bytes(inode, number);
1444                 goto out;
1445         }
1446
1447         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1448         if (IS_NOQUOTA(inode)) {
1449                 inode_add_bytes(inode, number);
1450                 goto out_unlock;
1451         }
1452
1453         ret = __dquot_alloc_space(inode, number, warn, 0);
1454         if (ret == NO_QUOTA)
1455                 goto out_unlock;
1456
1457         /* Dirtify all the dquots - this can block when journalling */
1458         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1459                 if (inode->i_dquot[cnt])
1460                         mark_dquot_dirty(inode->i_dquot[cnt]);
1461 out_unlock:
1462         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1463 out:
1464         return ret;
1465 }
1466 EXPORT_SYMBOL(dquot_alloc_space);
1467
1468 int dquot_reserve_space(struct inode *inode, qsize_t number, int warn)
1469 {
1470         int ret = QUOTA_OK;
1471
1472         if (IS_NOQUOTA(inode))
1473                 goto out;
1474
1475         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1476         if (IS_NOQUOTA(inode))
1477                 goto out_unlock;
1478
1479         ret = __dquot_alloc_space(inode, number, warn, 1);
1480 out_unlock:
1481         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1482 out:
1483         return ret;
1484 }
1485 EXPORT_SYMBOL(dquot_reserve_space);
1486
1487 /*
1488  * This operation can block, but only after everything is updated
1489  */
1490 int dquot_alloc_inode(const struct inode *inode, qsize_t number)
1491 {
1492         int cnt, ret = NO_QUOTA;
1493         char warntype[MAXQUOTAS];
1494
1495         /* First test before acquiring mutex - solves deadlocks when we
1496          * re-enter the quota code and are already holding the mutex */
1497         if (IS_NOQUOTA(inode))
1498                 return QUOTA_OK;
1499         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1500                 warntype[cnt] = QUOTA_NL_NOWARN;
1501         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1502         if (IS_NOQUOTA(inode)) {
1503                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1504                 return QUOTA_OK;
1505         }
1506         spin_lock(&dq_data_lock);
1507         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1508                 if (!inode->i_dquot[cnt])
1509                         continue;
1510                 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt)
1511                     == NO_QUOTA)
1512                         goto warn_put_all;
1513         }
1514
1515         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1516                 if (!inode->i_dquot[cnt])
1517                         continue;
1518                 dquot_incr_inodes(inode->i_dquot[cnt], number);
1519         }
1520         ret = QUOTA_OK;
1521 warn_put_all:
1522         spin_unlock(&dq_data_lock);
1523         if (ret == QUOTA_OK)
1524                 /* Dirtify all the dquots - this can block when journalling */
1525                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1526                         if (inode->i_dquot[cnt])
1527                                 mark_dquot_dirty(inode->i_dquot[cnt]);
1528         flush_warnings(inode->i_dquot, warntype);
1529         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1530         return ret;
1531 }
1532 EXPORT_SYMBOL(dquot_alloc_inode);
1533
1534 int dquot_claim_space(struct inode *inode, qsize_t number)
1535 {
1536         int cnt;
1537         int ret = QUOTA_OK;
1538
1539         if (IS_NOQUOTA(inode)) {
1540                 inode_add_bytes(inode, number);
1541                 goto out;
1542         }
1543
1544         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1545         if (IS_NOQUOTA(inode))  {
1546                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1547                 inode_add_bytes(inode, number);
1548                 goto out;
1549         }
1550
1551         spin_lock(&dq_data_lock);
1552         /* Claim reserved quotas to allocated quotas */
1553         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1554                 if (inode->i_dquot[cnt])
1555                         dquot_claim_reserved_space(inode->i_dquot[cnt],
1556                                                         number);
1557         }
1558         /* Update inode bytes */
1559         inode_add_bytes(inode, number);
1560         spin_unlock(&dq_data_lock);
1561         /* Dirtify all the dquots - this can block when journalling */
1562         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1563                 if (inode->i_dquot[cnt])
1564                         mark_dquot_dirty(inode->i_dquot[cnt]);
1565         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1566 out:
1567         return ret;
1568 }
1569 EXPORT_SYMBOL(dquot_claim_space);
1570
1571 /*
1572  * Release reserved quota space
1573  */
1574 void dquot_release_reserved_space(struct inode *inode, qsize_t number)
1575 {
1576         int cnt;
1577
1578         if (IS_NOQUOTA(inode))
1579                 goto out;
1580
1581         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1582         if (IS_NOQUOTA(inode))
1583                 goto out_unlock;
1584
1585         spin_lock(&dq_data_lock);
1586         /* Release reserved dquots */
1587         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1588                 if (inode->i_dquot[cnt])
1589                         dquot_free_reserved_space(inode->i_dquot[cnt], number);
1590         }
1591         spin_unlock(&dq_data_lock);
1592
1593 out_unlock:
1594         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1595 out:
1596         return;
1597 }
1598 EXPORT_SYMBOL(dquot_release_reserved_space);
1599
1600 /*
1601  * This operation can block, but only after everything is updated
1602  */
1603 int dquot_free_space(struct inode *inode, qsize_t number)
1604 {
1605         unsigned int cnt;
1606         char warntype[MAXQUOTAS];
1607
1608         /* First test before acquiring mutex - solves deadlocks when we
1609          * re-enter the quota code and are already holding the mutex */
1610         if (IS_NOQUOTA(inode)) {
1611 out_sub:
1612                 inode_sub_bytes(inode, number);
1613                 return QUOTA_OK;
1614         }
1615
1616         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1617         /* Now recheck reliably when holding dqptr_sem */
1618         if (IS_NOQUOTA(inode)) {
1619                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1620                 goto out_sub;
1621         }
1622         spin_lock(&dq_data_lock);
1623         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1624                 if (!inode->i_dquot[cnt])
1625                         continue;
1626                 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
1627                 dquot_decr_space(inode->i_dquot[cnt], number);
1628         }
1629         inode_sub_bytes(inode, number);
1630         spin_unlock(&dq_data_lock);
1631         /* Dirtify all the dquots - this can block when journalling */
1632         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1633                 if (inode->i_dquot[cnt])
1634                         mark_dquot_dirty(inode->i_dquot[cnt]);
1635         flush_warnings(inode->i_dquot, warntype);
1636         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1637         return QUOTA_OK;
1638 }
1639 EXPORT_SYMBOL(dquot_free_space);
1640
1641 /*
1642  * This operation can block, but only after everything is updated
1643  */
1644 int dquot_free_inode(const struct inode *inode, qsize_t number)
1645 {
1646         unsigned int cnt;
1647         char warntype[MAXQUOTAS];
1648
1649         /* First test before acquiring mutex - solves deadlocks when we
1650          * re-enter the quota code and are already holding the mutex */
1651         if (IS_NOQUOTA(inode))
1652                 return QUOTA_OK;
1653
1654         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1655         /* Now recheck reliably when holding dqptr_sem */
1656         if (IS_NOQUOTA(inode)) {
1657                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1658                 return QUOTA_OK;
1659         }
1660         spin_lock(&dq_data_lock);
1661         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1662                 if (!inode->i_dquot[cnt])
1663                         continue;
1664                 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], number);
1665                 dquot_decr_inodes(inode->i_dquot[cnt], number);
1666         }
1667         spin_unlock(&dq_data_lock);
1668         /* Dirtify all the dquots - this can block when journalling */
1669         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1670                 if (inode->i_dquot[cnt])
1671                         mark_dquot_dirty(inode->i_dquot[cnt]);
1672         flush_warnings(inode->i_dquot, warntype);
1673         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1674         return QUOTA_OK;
1675 }
1676 EXPORT_SYMBOL(dquot_free_inode);
1677
1678 /*
1679  * call back function, get reserved quota space from underlying fs
1680  */
1681 qsize_t dquot_get_reserved_space(struct inode *inode)
1682 {
1683         qsize_t reserved_space = 0;
1684
1685         if (sb_any_quota_active(inode->i_sb) &&
1686             inode->i_sb->dq_op->get_reserved_space)
1687                 reserved_space = inode->i_sb->dq_op->get_reserved_space(inode);
1688         return reserved_space;
1689 }
1690
1691 /*
1692  * Transfer the number of inode and blocks from one diskquota to an other.
1693  *
1694  * This operation can block, but only after everything is updated
1695  * A transaction must be started when entering this function.
1696  */
1697 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1698 {
1699         qsize_t space, cur_space;
1700         qsize_t rsv_space = 0;
1701         struct dquot *transfer_from[MAXQUOTAS];
1702         struct dquot *transfer_to[MAXQUOTAS];
1703         int cnt, ret = QUOTA_OK;
1704         int chuid = iattr->ia_valid & ATTR_UID && inode->i_uid != iattr->ia_uid,
1705             chgid = iattr->ia_valid & ATTR_GID && inode->i_gid != iattr->ia_gid;
1706         char warntype_to[MAXQUOTAS];
1707         char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
1708
1709         /* First test before acquiring mutex - solves deadlocks when we
1710          * re-enter the quota code and are already holding the mutex */
1711         if (IS_NOQUOTA(inode))
1712                 return QUOTA_OK;
1713         /* Initialize the arrays */
1714         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1715                 transfer_from[cnt] = NULL;
1716                 transfer_to[cnt] = NULL;
1717                 warntype_to[cnt] = QUOTA_NL_NOWARN;
1718         }
1719         if (chuid)
1720                 transfer_to[USRQUOTA] = dqget(inode->i_sb, iattr->ia_uid,
1721                                               USRQUOTA);
1722         if (chgid)
1723                 transfer_to[GRPQUOTA] = dqget(inode->i_sb, iattr->ia_gid,
1724                                               GRPQUOTA);
1725
1726         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1727         /* Now recheck reliably when holding dqptr_sem */
1728         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1729                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1730                 goto put_all;
1731         }
1732         spin_lock(&dq_data_lock);
1733         cur_space = inode_get_bytes(inode);
1734         rsv_space = dquot_get_reserved_space(inode);
1735         space = cur_space + rsv_space;
1736         /* Build the transfer_from list and check the limits */
1737         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1738                 if (!transfer_to[cnt])
1739                         continue;
1740                 transfer_from[cnt] = inode->i_dquot[cnt];
1741                 if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) ==
1742                     NO_QUOTA || check_bdq(transfer_to[cnt], space, 0,
1743                     warntype_to + cnt) == NO_QUOTA)
1744                         goto over_quota;
1745         }
1746
1747         /*
1748          * Finally perform the needed transfer from transfer_from to transfer_to
1749          */
1750         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1751                 /*
1752                  * Skip changes for same uid or gid or for turned off quota-type.
1753                  */
1754                 if (!transfer_to[cnt])
1755                         continue;
1756
1757                 /* Due to IO error we might not have transfer_from[] structure */
1758                 if (transfer_from[cnt]) {
1759                         warntype_from_inodes[cnt] =
1760                                 info_idq_free(transfer_from[cnt], 1);
1761                         warntype_from_space[cnt] =
1762                                 info_bdq_free(transfer_from[cnt], space);
1763                         dquot_decr_inodes(transfer_from[cnt], 1);
1764                         dquot_decr_space(transfer_from[cnt], cur_space);
1765                         dquot_free_reserved_space(transfer_from[cnt],
1766                                                   rsv_space);
1767                 }
1768
1769                 dquot_incr_inodes(transfer_to[cnt], 1);
1770                 dquot_incr_space(transfer_to[cnt], cur_space);
1771                 dquot_resv_space(transfer_to[cnt], rsv_space);
1772
1773                 inode->i_dquot[cnt] = transfer_to[cnt];
1774         }
1775         spin_unlock(&dq_data_lock);
1776         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1777
1778         /* Dirtify all the dquots - this can block when journalling */
1779         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1780                 if (transfer_from[cnt])
1781                         mark_dquot_dirty(transfer_from[cnt]);
1782                 if (transfer_to[cnt]) {
1783                         mark_dquot_dirty(transfer_to[cnt]);
1784                         /* The reference we got is transferred to the inode */
1785                         transfer_to[cnt] = NULL;
1786                 }
1787         }
1788 warn_put_all:
1789         flush_warnings(transfer_to, warntype_to);
1790         flush_warnings(transfer_from, warntype_from_inodes);
1791         flush_warnings(transfer_from, warntype_from_space);
1792 put_all:
1793         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1794                 dqput(transfer_from[cnt]);
1795                 dqput(transfer_to[cnt]);
1796         }
1797         return ret;
1798 over_quota:
1799         spin_unlock(&dq_data_lock);
1800         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1801         /* Clear dquot pointers we don't want to dqput() */
1802         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1803                 transfer_from[cnt] = NULL;
1804         ret = NO_QUOTA;
1805         goto warn_put_all;
1806 }
1807 EXPORT_SYMBOL(dquot_transfer);
1808
1809 /* Wrapper for transferring ownership of an inode */
1810 int vfs_dq_transfer(struct inode *inode, struct iattr *iattr)
1811 {
1812         if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) {
1813                 vfs_dq_init(inode);
1814                 if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA)
1815                         return 1;
1816         }
1817         return 0;
1818 }
1819 EXPORT_SYMBOL(vfs_dq_transfer);
1820
1821 /*
1822  * Write info of quota file to disk
1823  */
1824 int dquot_commit_info(struct super_block *sb, int type)
1825 {
1826         int ret;
1827         struct quota_info *dqopt = sb_dqopt(sb);
1828
1829         mutex_lock(&dqopt->dqio_mutex);
1830         ret = dqopt->ops[type]->write_file_info(sb, type);
1831         mutex_unlock(&dqopt->dqio_mutex);
1832         return ret;
1833 }
1834 EXPORT_SYMBOL(dquot_commit_info);
1835
1836 /*
1837  * Definitions of diskquota operations.
1838  */
1839 struct dquot_operations dquot_operations = {
1840         .initialize     = dquot_initialize,
1841         .drop           = dquot_drop,
1842         .alloc_space    = dquot_alloc_space,
1843         .alloc_inode    = dquot_alloc_inode,
1844         .free_space     = dquot_free_space,
1845         .free_inode     = dquot_free_inode,
1846         .transfer       = dquot_transfer,
1847         .write_dquot    = dquot_commit,
1848         .acquire_dquot  = dquot_acquire,
1849         .release_dquot  = dquot_release,
1850         .mark_dirty     = dquot_mark_dquot_dirty,
1851         .write_info     = dquot_commit_info,
1852         .alloc_dquot    = dquot_alloc,
1853         .destroy_dquot  = dquot_destroy,
1854 };
1855
1856 /*
1857  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1858  */
1859 int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags)
1860 {
1861         int cnt, ret = 0;
1862         struct quota_info *dqopt = sb_dqopt(sb);
1863         struct inode *toputinode[MAXQUOTAS];
1864
1865         /* Cannot turn off usage accounting without turning off limits, or
1866          * suspend quotas and simultaneously turn quotas off. */
1867         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1868             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1869             DQUOT_USAGE_ENABLED)))
1870                 return -EINVAL;
1871
1872         /* We need to serialize quota_off() for device */
1873         mutex_lock(&dqopt->dqonoff_mutex);
1874
1875         /*
1876          * Skip everything if there's nothing to do. We have to do this because
1877          * sometimes we are called when fill_super() failed and calling
1878          * sync_fs() in such cases does no good.
1879          */
1880         if (!sb_any_quota_loaded(sb)) {
1881                 mutex_unlock(&dqopt->dqonoff_mutex);
1882                 return 0;
1883         }
1884         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1885                 toputinode[cnt] = NULL;
1886                 if (type != -1 && cnt != type)
1887                         continue;
1888                 if (!sb_has_quota_loaded(sb, cnt))
1889                         continue;
1890
1891                 if (flags & DQUOT_SUSPENDED) {
1892                         spin_lock(&dq_state_lock);
1893                         dqopt->flags |=
1894                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1895                         spin_unlock(&dq_state_lock);
1896                 } else {
1897                         spin_lock(&dq_state_lock);
1898                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
1899                         /* Turning off suspended quotas? */
1900                         if (!sb_has_quota_loaded(sb, cnt) &&
1901                             sb_has_quota_suspended(sb, cnt)) {
1902                                 dqopt->flags &= ~dquot_state_flag(
1903                                                         DQUOT_SUSPENDED, cnt);
1904                                 spin_unlock(&dq_state_lock);
1905                                 iput(dqopt->files[cnt]);
1906                                 dqopt->files[cnt] = NULL;
1907                                 continue;
1908                         }
1909                         spin_unlock(&dq_state_lock);
1910                 }
1911
1912                 /* We still have to keep quota loaded? */
1913                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
1914                         continue;
1915
1916                 /* Note: these are blocking operations */
1917                 drop_dquot_ref(sb, cnt);
1918                 invalidate_dquots(sb, cnt);
1919                 /*
1920                  * Now all dquots should be invalidated, all writes done so we
1921                  * should be only users of the info. No locks needed.
1922                  */
1923                 if (info_dirty(&dqopt->info[cnt]))
1924                         sb->dq_op->write_info(sb, cnt);
1925                 if (dqopt->ops[cnt]->free_file_info)
1926                         dqopt->ops[cnt]->free_file_info(sb, cnt);
1927                 put_quota_format(dqopt->info[cnt].dqi_format);
1928
1929                 toputinode[cnt] = dqopt->files[cnt];
1930                 if (!sb_has_quota_loaded(sb, cnt))
1931                         dqopt->files[cnt] = NULL;
1932                 dqopt->info[cnt].dqi_flags = 0;
1933                 dqopt->info[cnt].dqi_igrace = 0;
1934                 dqopt->info[cnt].dqi_bgrace = 0;
1935                 dqopt->ops[cnt] = NULL;
1936         }
1937         mutex_unlock(&dqopt->dqonoff_mutex);
1938
1939         /* Skip syncing and setting flags if quota files are hidden */
1940         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
1941                 goto put_inodes;
1942
1943         /* Sync the superblock so that buffers with quota data are written to
1944          * disk (and so userspace sees correct data afterwards). */
1945         if (sb->s_op->sync_fs)
1946                 sb->s_op->sync_fs(sb, 1);
1947         sync_blockdev(sb->s_bdev);
1948         /* Now the quota files are just ordinary files and we can set the
1949          * inode flags back. Moreover we discard the pagecache so that
1950          * userspace sees the writes we did bypassing the pagecache. We
1951          * must also discard the blockdev buffers so that we see the
1952          * changes done by userspace on the next quotaon() */
1953         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1954                 if (toputinode[cnt]) {
1955                         mutex_lock(&dqopt->dqonoff_mutex);
1956                         /* If quota was reenabled in the meantime, we have
1957                          * nothing to do */
1958                         if (!sb_has_quota_loaded(sb, cnt)) {
1959                                 mutex_lock_nested(&toputinode[cnt]->i_mutex,
1960                                                   I_MUTEX_QUOTA);
1961                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1962                                   S_NOATIME | S_NOQUOTA);
1963                                 truncate_inode_pages(&toputinode[cnt]->i_data,
1964                                                      0);
1965                                 mutex_unlock(&toputinode[cnt]->i_mutex);
1966                                 mark_inode_dirty(toputinode[cnt]);
1967                         }
1968                         mutex_unlock(&dqopt->dqonoff_mutex);
1969                 }
1970         if (sb->s_bdev)
1971                 invalidate_bdev(sb->s_bdev);
1972 put_inodes:
1973         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1974                 if (toputinode[cnt]) {
1975                         /* On remount RO, we keep the inode pointer so that we
1976                          * can reenable quota on the subsequent remount RW. We
1977                          * have to check 'flags' variable and not use sb_has_
1978                          * function because another quotaon / quotaoff could
1979                          * change global state before we got here. We refuse
1980                          * to suspend quotas when there is pending delete on
1981                          * the quota file... */
1982                         if (!(flags & DQUOT_SUSPENDED))
1983                                 iput(toputinode[cnt]);
1984                         else if (!toputinode[cnt]->i_nlink)
1985                                 ret = -EBUSY;
1986                 }
1987         return ret;
1988 }
1989 EXPORT_SYMBOL(vfs_quota_disable);
1990
1991 int vfs_quota_off(struct super_block *sb, int type, int remount)
1992 {
1993         return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED :
1994                                  (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED));
1995 }
1996 EXPORT_SYMBOL(vfs_quota_off);
1997 /*
1998  *      Turn quotas on on a device
1999  */
2000
2001 /*
2002  * Helper function to turn quotas on when we already have the inode of
2003  * quota file and no quota information is loaded.
2004  */
2005 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2006         unsigned int flags)
2007 {
2008         struct quota_format_type *fmt = find_quota_format(format_id);
2009         struct super_block *sb = inode->i_sb;
2010         struct quota_info *dqopt = sb_dqopt(sb);
2011         int error;
2012         int oldflags = -1;
2013
2014         if (!fmt)
2015                 return -ESRCH;
2016         if (!S_ISREG(inode->i_mode)) {
2017                 error = -EACCES;
2018                 goto out_fmt;
2019         }
2020         if (IS_RDONLY(inode)) {
2021                 error = -EROFS;
2022                 goto out_fmt;
2023         }
2024         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
2025                 error = -EINVAL;
2026                 goto out_fmt;
2027         }
2028         /* Usage always has to be set... */
2029         if (!(flags & DQUOT_USAGE_ENABLED)) {
2030                 error = -EINVAL;
2031                 goto out_fmt;
2032         }
2033
2034         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2035                 /* As we bypass the pagecache we must now flush the inode so
2036                  * that we see all the changes from userspace... */
2037                 write_inode_now(inode, 1);
2038                 /* And now flush the block cache so that kernel sees the
2039                  * changes */
2040                 invalidate_bdev(sb->s_bdev);
2041         }
2042         mutex_lock(&inode->i_mutex);
2043         mutex_lock(&dqopt->dqonoff_mutex);
2044         if (sb_has_quota_loaded(sb, type)) {
2045                 error = -EBUSY;
2046                 goto out_lock;
2047         }
2048
2049         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2050                 /* We don't want quota and atime on quota files (deadlocks
2051                  * possible) Also nobody should write to the file - we use
2052                  * special IO operations which ignore the immutable bit. */
2053                 down_write(&dqopt->dqptr_sem);
2054                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2055                                              S_NOQUOTA);
2056                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2057                 up_write(&dqopt->dqptr_sem);
2058                 sb->dq_op->drop(inode);
2059         }
2060
2061         error = -EIO;
2062         dqopt->files[type] = igrab(inode);
2063         if (!dqopt->files[type])
2064                 goto out_lock;
2065         error = -EINVAL;
2066         if (!fmt->qf_ops->check_quota_file(sb, type))
2067                 goto out_file_init;
2068
2069         dqopt->ops[type] = fmt->qf_ops;
2070         dqopt->info[type].dqi_format = fmt;
2071         dqopt->info[type].dqi_fmt_id = format_id;
2072         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2073         mutex_lock(&dqopt->dqio_mutex);
2074         error = dqopt->ops[type]->read_file_info(sb, type);
2075         if (error < 0) {
2076                 mutex_unlock(&dqopt->dqio_mutex);
2077                 goto out_file_init;
2078         }
2079         mutex_unlock(&dqopt->dqio_mutex);
2080         mutex_unlock(&inode->i_mutex);
2081         spin_lock(&dq_state_lock);
2082         dqopt->flags |= dquot_state_flag(flags, type);
2083         spin_unlock(&dq_state_lock);
2084
2085         add_dquot_ref(sb, type);
2086         mutex_unlock(&dqopt->dqonoff_mutex);
2087
2088         return 0;
2089
2090 out_file_init:
2091         dqopt->files[type] = NULL;
2092         iput(inode);
2093 out_lock:
2094         mutex_unlock(&dqopt->dqonoff_mutex);
2095         if (oldflags != -1) {
2096                 down_write(&dqopt->dqptr_sem);
2097                 /* Set the flags back (in the case of accidental quotaon()
2098                  * on a wrong file we don't want to mess up the flags) */
2099                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2100                 inode->i_flags |= oldflags;
2101                 up_write(&dqopt->dqptr_sem);
2102         }
2103         mutex_unlock(&inode->i_mutex);
2104 out_fmt:
2105         put_quota_format(fmt);
2106
2107         return error; 
2108 }
2109
2110 /* Reenable quotas on remount RW */
2111 static int vfs_quota_on_remount(struct super_block *sb, int type)
2112 {
2113         struct quota_info *dqopt = sb_dqopt(sb);
2114         struct inode *inode;
2115         int ret;
2116         unsigned int flags;
2117
2118         mutex_lock(&dqopt->dqonoff_mutex);
2119         if (!sb_has_quota_suspended(sb, type)) {
2120                 mutex_unlock(&dqopt->dqonoff_mutex);
2121                 return 0;
2122         }
2123         inode = dqopt->files[type];
2124         dqopt->files[type] = NULL;
2125         spin_lock(&dq_state_lock);
2126         flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2127                                                 DQUOT_LIMITS_ENABLED, type);
2128         dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type);
2129         spin_unlock(&dq_state_lock);
2130         mutex_unlock(&dqopt->dqonoff_mutex);
2131
2132         flags = dquot_generic_flag(flags, type);
2133         ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id,
2134                                    flags);
2135         iput(inode);
2136
2137         return ret;
2138 }
2139
2140 int vfs_quota_on_path(struct super_block *sb, int type, int format_id,
2141                       struct path *path)
2142 {
2143         int error = security_quota_on(path->dentry);
2144         if (error)
2145                 return error;
2146         /* Quota file not on the same filesystem? */
2147         if (path->mnt->mnt_sb != sb)
2148                 error = -EXDEV;
2149         else
2150                 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2151                                              format_id, DQUOT_USAGE_ENABLED |
2152                                              DQUOT_LIMITS_ENABLED);
2153         return error;
2154 }
2155 EXPORT_SYMBOL(vfs_quota_on_path);
2156
2157 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name,
2158                  int remount)
2159 {
2160         struct path path;
2161         int error;
2162
2163         if (remount)
2164                 return vfs_quota_on_remount(sb, type);
2165
2166         error = kern_path(name, LOOKUP_FOLLOW, &path);
2167         if (!error) {
2168                 error = vfs_quota_on_path(sb, type, format_id, &path);
2169                 path_put(&path);
2170         }
2171         return error;
2172 }
2173 EXPORT_SYMBOL(vfs_quota_on);
2174
2175 /*
2176  * More powerful function for turning on quotas allowing setting
2177  * of individual quota flags
2178  */
2179 int vfs_quota_enable(struct inode *inode, int type, int format_id,
2180                 unsigned int flags)
2181 {
2182         int ret = 0;
2183         struct super_block *sb = inode->i_sb;
2184         struct quota_info *dqopt = sb_dqopt(sb);
2185
2186         /* Just unsuspend quotas? */
2187         if (flags & DQUOT_SUSPENDED)
2188                 return vfs_quota_on_remount(sb, type);
2189         if (!flags)
2190                 return 0;
2191         /* Just updating flags needed? */
2192         if (sb_has_quota_loaded(sb, type)) {
2193                 mutex_lock(&dqopt->dqonoff_mutex);
2194                 /* Now do a reliable test... */
2195                 if (!sb_has_quota_loaded(sb, type)) {
2196                         mutex_unlock(&dqopt->dqonoff_mutex);
2197                         goto load_quota;
2198                 }
2199                 if (flags & DQUOT_USAGE_ENABLED &&
2200                     sb_has_quota_usage_enabled(sb, type)) {
2201                         ret = -EBUSY;
2202                         goto out_lock;
2203                 }
2204                 if (flags & DQUOT_LIMITS_ENABLED &&
2205                     sb_has_quota_limits_enabled(sb, type)) {
2206                         ret = -EBUSY;
2207                         goto out_lock;
2208                 }
2209                 spin_lock(&dq_state_lock);
2210                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2211                 spin_unlock(&dq_state_lock);
2212 out_lock:
2213                 mutex_unlock(&dqopt->dqonoff_mutex);
2214                 return ret;
2215         }
2216
2217 load_quota:
2218         return vfs_load_quota_inode(inode, type, format_id, flags);
2219 }
2220 EXPORT_SYMBOL(vfs_quota_enable);
2221
2222 /*
2223  * This function is used when filesystem needs to initialize quotas
2224  * during mount time.
2225  */
2226 int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
2227                 int format_id, int type)
2228 {
2229         struct dentry *dentry;
2230         int error;
2231
2232         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2233         if (IS_ERR(dentry))
2234                 return PTR_ERR(dentry);
2235
2236         if (!dentry->d_inode) {
2237                 error = -ENOENT;
2238                 goto out;
2239         }
2240
2241         error = security_quota_on(dentry);
2242         if (!error)
2243                 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2244                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2245
2246 out:
2247         dput(dentry);
2248         return error;
2249 }
2250 EXPORT_SYMBOL(vfs_quota_on_mount);
2251
2252 /* Wrapper to turn on quotas when remounting rw */
2253 int vfs_dq_quota_on_remount(struct super_block *sb)
2254 {
2255         int cnt;
2256         int ret = 0, err;
2257
2258         if (!sb->s_qcop || !sb->s_qcop->quota_on)
2259                 return -ENOSYS;
2260         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2261                 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1);
2262                 if (err < 0 && !ret)
2263                         ret = err;
2264         }
2265         return ret;
2266 }
2267 EXPORT_SYMBOL(vfs_dq_quota_on_remount);
2268
2269 static inline qsize_t qbtos(qsize_t blocks)
2270 {
2271         return blocks << QIF_DQBLKSIZE_BITS;
2272 }
2273
2274 static inline qsize_t stoqb(qsize_t space)
2275 {
2276         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2277 }
2278
2279 /* Generic routine for getting common part of quota structure */
2280 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
2281 {
2282         struct mem_dqblk *dm = &dquot->dq_dqb;
2283
2284         spin_lock(&dq_data_lock);
2285         di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit);
2286         di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit);
2287         di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace;
2288         di->dqb_ihardlimit = dm->dqb_ihardlimit;
2289         di->dqb_isoftlimit = dm->dqb_isoftlimit;
2290         di->dqb_curinodes = dm->dqb_curinodes;
2291         di->dqb_btime = dm->dqb_btime;
2292         di->dqb_itime = dm->dqb_itime;
2293         di->dqb_valid = QIF_ALL;
2294         spin_unlock(&dq_data_lock);
2295 }
2296
2297 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id,
2298                   struct if_dqblk *di)
2299 {
2300         struct dquot *dquot;
2301
2302         dquot = dqget(sb, id, type);
2303         if (!dquot)
2304                 return -ESRCH;
2305         do_get_dqblk(dquot, di);
2306         dqput(dquot);
2307
2308         return 0;
2309 }
2310 EXPORT_SYMBOL(vfs_get_dqblk);
2311
2312 /* Generic routine for setting common part of quota structure */
2313 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
2314 {
2315         struct mem_dqblk *dm = &dquot->dq_dqb;
2316         int check_blim = 0, check_ilim = 0;
2317         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2318
2319         if ((di->dqb_valid & QIF_BLIMITS &&
2320              (di->dqb_bhardlimit > dqi->dqi_maxblimit ||
2321               di->dqb_bsoftlimit > dqi->dqi_maxblimit)) ||
2322             (di->dqb_valid & QIF_ILIMITS &&
2323              (di->dqb_ihardlimit > dqi->dqi_maxilimit ||
2324               di->dqb_isoftlimit > dqi->dqi_maxilimit)))
2325                 return -ERANGE;
2326
2327         spin_lock(&dq_data_lock);
2328         if (di->dqb_valid & QIF_SPACE) {
2329                 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace;
2330                 check_blim = 1;
2331                 __set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2332         }
2333         if (di->dqb_valid & QIF_BLIMITS) {
2334                 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit);
2335                 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit);
2336                 check_blim = 1;
2337                 __set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2338         }
2339         if (di->dqb_valid & QIF_INODES) {
2340                 dm->dqb_curinodes = di->dqb_curinodes;
2341                 check_ilim = 1;
2342                 __set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2343         }
2344         if (di->dqb_valid & QIF_ILIMITS) {
2345                 dm->dqb_isoftlimit = di->dqb_isoftlimit;
2346                 dm->dqb_ihardlimit = di->dqb_ihardlimit;
2347                 check_ilim = 1;
2348                 __set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2349         }
2350         if (di->dqb_valid & QIF_BTIME) {
2351                 dm->dqb_btime = di->dqb_btime;
2352                 check_blim = 1;
2353                 __set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2354         }
2355         if (di->dqb_valid & QIF_ITIME) {
2356                 dm->dqb_itime = di->dqb_itime;
2357                 check_ilim = 1;
2358                 __set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2359         }
2360
2361         if (check_blim) {
2362                 if (!dm->dqb_bsoftlimit ||
2363                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2364                         dm->dqb_btime = 0;
2365                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2366                 } else if (!(di->dqb_valid & QIF_BTIME))
2367                         /* Set grace only if user hasn't provided his own... */
2368                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2369         }
2370         if (check_ilim) {
2371                 if (!dm->dqb_isoftlimit ||
2372                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2373                         dm->dqb_itime = 0;
2374                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2375                 } else if (!(di->dqb_valid & QIF_ITIME))
2376                         /* Set grace only if user hasn't provided his own... */
2377                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2378         }
2379         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2380             dm->dqb_isoftlimit)
2381                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2382         else
2383                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2384         spin_unlock(&dq_data_lock);
2385         mark_dquot_dirty(dquot);
2386
2387         return 0;
2388 }
2389
2390 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id,
2391                   struct if_dqblk *di)
2392 {
2393         struct dquot *dquot;
2394         int rc;
2395
2396         dquot = dqget(sb, id, type);
2397         if (!dquot) {
2398                 rc = -ESRCH;
2399                 goto out;
2400         }
2401         rc = do_set_dqblk(dquot, di);
2402         dqput(dquot);
2403 out:
2404         return rc;
2405 }
2406 EXPORT_SYMBOL(vfs_set_dqblk);
2407
2408 /* Generic routine for getting common part of quota file information */
2409 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2410 {
2411         struct mem_dqinfo *mi;
2412   
2413         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2414         if (!sb_has_quota_active(sb, type)) {
2415                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2416                 return -ESRCH;
2417         }
2418         mi = sb_dqopt(sb)->info + type;
2419         spin_lock(&dq_data_lock);
2420         ii->dqi_bgrace = mi->dqi_bgrace;
2421         ii->dqi_igrace = mi->dqi_igrace;
2422         ii->dqi_flags = mi->dqi_flags & DQF_MASK;
2423         ii->dqi_valid = IIF_ALL;
2424         spin_unlock(&dq_data_lock);
2425         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2426         return 0;
2427 }
2428 EXPORT_SYMBOL(vfs_get_dqinfo);
2429
2430 /* Generic routine for setting common part of quota file information */
2431 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2432 {
2433         struct mem_dqinfo *mi;
2434         int err = 0;
2435
2436         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2437         if (!sb_has_quota_active(sb, type)) {
2438                 err = -ESRCH;
2439                 goto out;
2440         }
2441         mi = sb_dqopt(sb)->info + type;
2442         spin_lock(&dq_data_lock);
2443         if (ii->dqi_valid & IIF_BGRACE)
2444                 mi->dqi_bgrace = ii->dqi_bgrace;
2445         if (ii->dqi_valid & IIF_IGRACE)
2446                 mi->dqi_igrace = ii->dqi_igrace;
2447         if (ii->dqi_valid & IIF_FLAGS)
2448                 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) |
2449                                 (ii->dqi_flags & DQF_MASK);
2450         spin_unlock(&dq_data_lock);
2451         mark_info_dirty(sb, type);
2452         /* Force write to disk */
2453         sb->dq_op->write_info(sb, type);
2454 out:
2455         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2456         return err;
2457 }
2458 EXPORT_SYMBOL(vfs_set_dqinfo);
2459
2460 struct quotactl_ops vfs_quotactl_ops = {
2461         .quota_on       = vfs_quota_on,
2462         .quota_off      = vfs_quota_off,
2463         .quota_sync     = vfs_quota_sync,
2464         .get_info       = vfs_get_dqinfo,
2465         .set_info       = vfs_set_dqinfo,
2466         .get_dqblk      = vfs_get_dqblk,
2467         .set_dqblk      = vfs_set_dqblk
2468 };
2469
2470 static ctl_table fs_dqstats_table[] = {
2471         {
2472                 .ctl_name       = FS_DQ_LOOKUPS,
2473                 .procname       = "lookups",
2474                 .data           = &dqstats.lookups,
2475                 .maxlen         = sizeof(int),
2476                 .mode           = 0444,
2477                 .proc_handler   = &proc_dointvec,
2478         },
2479         {
2480                 .ctl_name       = FS_DQ_DROPS,
2481                 .procname       = "drops",
2482                 .data           = &dqstats.drops,
2483                 .maxlen         = sizeof(int),
2484                 .mode           = 0444,
2485                 .proc_handler   = &proc_dointvec,
2486         },
2487         {
2488                 .ctl_name       = FS_DQ_READS,
2489                 .procname       = "reads",
2490                 .data           = &dqstats.reads,
2491                 .maxlen         = sizeof(int),
2492                 .mode           = 0444,
2493                 .proc_handler   = &proc_dointvec,
2494         },
2495         {
2496                 .ctl_name       = FS_DQ_WRITES,
2497                 .procname       = "writes",
2498                 .data           = &dqstats.writes,
2499                 .maxlen         = sizeof(int),
2500                 .mode           = 0444,
2501                 .proc_handler   = &proc_dointvec,
2502         },
2503         {
2504                 .ctl_name       = FS_DQ_CACHE_HITS,
2505                 .procname       = "cache_hits",
2506                 .data           = &dqstats.cache_hits,
2507                 .maxlen         = sizeof(int),
2508                 .mode           = 0444,
2509                 .proc_handler   = &proc_dointvec,
2510         },
2511         {
2512                 .ctl_name       = FS_DQ_ALLOCATED,
2513                 .procname       = "allocated_dquots",
2514                 .data           = &dqstats.allocated_dquots,
2515                 .maxlen         = sizeof(int),
2516                 .mode           = 0444,
2517                 .proc_handler   = &proc_dointvec,
2518         },
2519         {
2520                 .ctl_name       = FS_DQ_FREE,
2521                 .procname       = "free_dquots",
2522                 .data           = &dqstats.free_dquots,
2523                 .maxlen         = sizeof(int),
2524                 .mode           = 0444,
2525                 .proc_handler   = &proc_dointvec,
2526         },
2527         {
2528                 .ctl_name       = FS_DQ_SYNCS,
2529                 .procname       = "syncs",
2530                 .data           = &dqstats.syncs,
2531                 .maxlen         = sizeof(int),
2532                 .mode           = 0444,
2533                 .proc_handler   = &proc_dointvec,
2534         },
2535 #ifdef CONFIG_PRINT_QUOTA_WARNING
2536         {
2537                 .ctl_name       = FS_DQ_WARNINGS,
2538                 .procname       = "warnings",
2539                 .data           = &flag_print_warnings,
2540                 .maxlen         = sizeof(int),
2541                 .mode           = 0644,
2542                 .proc_handler   = &proc_dointvec,
2543         },
2544 #endif
2545         { .ctl_name = 0 },
2546 };
2547
2548 static ctl_table fs_table[] = {
2549         {
2550                 .ctl_name       = FS_DQSTATS,
2551                 .procname       = "quota",
2552                 .mode           = 0555,
2553                 .child          = fs_dqstats_table,
2554         },
2555         { .ctl_name = 0 },
2556 };
2557
2558 static ctl_table sys_table[] = {
2559         {
2560                 .ctl_name       = CTL_FS,
2561                 .procname       = "fs",
2562                 .mode           = 0555,
2563                 .child          = fs_table,
2564         },
2565         { .ctl_name = 0 },
2566 };
2567
2568 static int __init dquot_init(void)
2569 {
2570         int i;
2571         unsigned long nr_hash, order;
2572
2573         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2574
2575         register_sysctl_table(sys_table);
2576
2577         dquot_cachep = kmem_cache_create("dquot",
2578                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2579                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2580                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2581                         NULL);
2582
2583         order = 0;
2584         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2585         if (!dquot_hash)
2586                 panic("Cannot create dquot hash table");
2587
2588         /* Find power-of-two hlist_heads which can fit into allocation */
2589         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2590         dq_hash_bits = 0;
2591         do {
2592                 dq_hash_bits++;
2593         } while (nr_hash >> dq_hash_bits);
2594         dq_hash_bits--;
2595
2596         nr_hash = 1UL << dq_hash_bits;
2597         dq_hash_mask = nr_hash - 1;
2598         for (i = 0; i < nr_hash; i++)
2599                 INIT_HLIST_HEAD(dquot_hash + i);
2600
2601         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2602                         nr_hash, order, (PAGE_SIZE << order));
2603
2604         register_shrinker(&dqcache_shrinker);
2605
2606 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
2607         if (genl_register_family(&quota_genl_family) != 0)
2608                 printk(KERN_ERR
2609                        "VFS: Failed to create quota netlink interface.\n");
2610 #endif
2611
2612         return 0;
2613 }
2614 module_init(dquot_init);