fs: move code out of buffer.c
[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/capability.h>
77 #include <linux/quotaops.h>
78 #include "../internal.h" /* ugh */
79
80 #include <asm/uaccess.h>
81
82 /*
83  * There are three quota SMP locks. dq_list_lock protects all lists with quotas
84  * and quota formats.
85  * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
86  * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
87  * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
88  * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
89  * modifications of quota state (on quotaon and quotaoff) and readers who care
90  * about latest values take it as well.
91  *
92  * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
93  *   dq_list_lock > dq_state_lock
94  *
95  * Note that some things (eg. sb pointer, type, id) doesn't change during
96  * the life of the dquot structure and so needn't to be protected by a lock
97  *
98  * Any operation working on dquots via inode pointers must hold dqptr_sem.  If
99  * operation is just reading pointers from inode (or not using them at all) the
100  * read lock is enough. If pointers are altered function must hold write lock.
101  * Special care needs to be taken about S_NOQUOTA inode flag (marking that
102  * inode is a quota file). Functions adding pointers from inode to dquots have
103  * to check this flag under dqptr_sem and then (if S_NOQUOTA is not set) they
104  * have to do all pointer modifications before dropping dqptr_sem. This makes
105  * sure they cannot race with quotaon which first sets S_NOQUOTA flag and
106  * then drops all pointers to dquots from an inode.
107  *
108  * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
109  * from inodes (dquot_alloc_space() and such don't check the dq_lock).
110  * Currently dquot is locked only when it is being read to memory (or space for
111  * it is being allocated) on the first dqget() and when it is being released on
112  * the last dqput(). The allocation and release oparations are serialized by
113  * the dq_lock and by checking the use count in dquot_release().  Write
114  * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
115  * spinlock to internal buffers before writing.
116  *
117  * Lock ordering (including related VFS locks) is the following:
118  *   i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
119  *   dqio_mutex
120  * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem >
121  * dqptr_sem. But filesystem has to count with the fact that functions such as
122  * dquot_alloc_space() acquire dqptr_sem and they usually have to be called
123  * from inside a transaction to keep filesystem consistency after a crash. Also
124  * filesystems usually want to do some IO on dquot from ->mark_dirty which is
125  * called with dqptr_sem held.
126  * i_mutex on quota files is special (it's below dqio_mutex)
127  */
128
129 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
130 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
131 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
132 EXPORT_SYMBOL(dq_data_lock);
133
134 void __quota_error(struct super_block *sb, const char *func,
135                    const char *fmt, ...)
136 {
137         if (printk_ratelimit()) {
138                 va_list args;
139                 struct va_format vaf;
140
141                 va_start(args, fmt);
142
143                 vaf.fmt = fmt;
144                 vaf.va = &args;
145
146                 printk(KERN_ERR "Quota error (device %s): %s: %pV\n",
147                        sb->s_id, func, &vaf);
148
149                 va_end(args);
150         }
151 }
152 EXPORT_SYMBOL(__quota_error);
153
154 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING)
155 static char *quotatypes[] = INITQFNAMES;
156 #endif
157 static struct quota_format_type *quota_formats; /* List of registered formats */
158 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
159
160 /* SLAB cache for dquot structures */
161 static struct kmem_cache *dquot_cachep;
162
163 int register_quota_format(struct quota_format_type *fmt)
164 {
165         spin_lock(&dq_list_lock);
166         fmt->qf_next = quota_formats;
167         quota_formats = fmt;
168         spin_unlock(&dq_list_lock);
169         return 0;
170 }
171 EXPORT_SYMBOL(register_quota_format);
172
173 void unregister_quota_format(struct quota_format_type *fmt)
174 {
175         struct quota_format_type **actqf;
176
177         spin_lock(&dq_list_lock);
178         for (actqf = &quota_formats; *actqf && *actqf != fmt;
179              actqf = &(*actqf)->qf_next)
180                 ;
181         if (*actqf)
182                 *actqf = (*actqf)->qf_next;
183         spin_unlock(&dq_list_lock);
184 }
185 EXPORT_SYMBOL(unregister_quota_format);
186
187 static struct quota_format_type *find_quota_format(int id)
188 {
189         struct quota_format_type *actqf;
190
191         spin_lock(&dq_list_lock);
192         for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
193              actqf = actqf->qf_next)
194                 ;
195         if (!actqf || !try_module_get(actqf->qf_owner)) {
196                 int qm;
197
198                 spin_unlock(&dq_list_lock);
199                 
200                 for (qm = 0; module_names[qm].qm_fmt_id &&
201                              module_names[qm].qm_fmt_id != id; qm++)
202                         ;
203                 if (!module_names[qm].qm_fmt_id ||
204                     request_module(module_names[qm].qm_mod_name))
205                         return NULL;
206
207                 spin_lock(&dq_list_lock);
208                 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
209                      actqf = actqf->qf_next)
210                         ;
211                 if (actqf && !try_module_get(actqf->qf_owner))
212                         actqf = NULL;
213         }
214         spin_unlock(&dq_list_lock);
215         return actqf;
216 }
217
218 static void put_quota_format(struct quota_format_type *fmt)
219 {
220         module_put(fmt->qf_owner);
221 }
222
223 /*
224  * Dquot List Management:
225  * The quota code uses three lists for dquot management: the inuse_list,
226  * free_dquots, and dquot_hash[] array. A single dquot structure may be
227  * on all three lists, depending on its current state.
228  *
229  * All dquots are placed to the end of inuse_list when first created, and this
230  * list is used for invalidate operation, which must look at every dquot.
231  *
232  * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
233  * and this list is searched whenever we need an available dquot.  Dquots are
234  * removed from the list as soon as they are used again, and
235  * dqstats.free_dquots gives the number of dquots on the list. When
236  * dquot is invalidated it's completely released from memory.
237  *
238  * Dquots with a specific identity (device, type and id) are placed on
239  * one of the dquot_hash[] hash chains. The provides an efficient search
240  * mechanism to locate a specific dquot.
241  */
242
243 static LIST_HEAD(inuse_list);
244 static LIST_HEAD(free_dquots);
245 static unsigned int dq_hash_bits, dq_hash_mask;
246 static struct hlist_head *dquot_hash;
247
248 struct dqstats dqstats;
249 EXPORT_SYMBOL(dqstats);
250
251 static qsize_t inode_get_rsv_space(struct inode *inode);
252 static void __dquot_initialize(struct inode *inode, int type);
253
254 static inline unsigned int
255 hashfn(const struct super_block *sb, unsigned int id, int type)
256 {
257         unsigned long tmp;
258
259         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
260         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
261 }
262
263 /*
264  * Following list functions expect dq_list_lock to be held
265  */
266 static inline void insert_dquot_hash(struct dquot *dquot)
267 {
268         struct hlist_head *head;
269         head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
270         hlist_add_head(&dquot->dq_hash, head);
271 }
272
273 static inline void remove_dquot_hash(struct dquot *dquot)
274 {
275         hlist_del_init(&dquot->dq_hash);
276 }
277
278 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
279                                 unsigned int id, int type)
280 {
281         struct hlist_node *node;
282         struct dquot *dquot;
283
284         hlist_for_each (node, dquot_hash+hashent) {
285                 dquot = hlist_entry(node, struct dquot, dq_hash);
286                 if (dquot->dq_sb == sb && dquot->dq_id == id &&
287                     dquot->dq_type == type)
288                         return dquot;
289         }
290         return NULL;
291 }
292
293 /* Add a dquot to the tail of the free list */
294 static inline void put_dquot_last(struct dquot *dquot)
295 {
296         list_add_tail(&dquot->dq_free, &free_dquots);
297         dqstats_inc(DQST_FREE_DQUOTS);
298 }
299
300 static inline void remove_free_dquot(struct dquot *dquot)
301 {
302         if (list_empty(&dquot->dq_free))
303                 return;
304         list_del_init(&dquot->dq_free);
305         dqstats_dec(DQST_FREE_DQUOTS);
306 }
307
308 static inline void put_inuse(struct dquot *dquot)
309 {
310         /* We add to the back of inuse list so we don't have to restart
311          * when traversing this list and we block */
312         list_add_tail(&dquot->dq_inuse, &inuse_list);
313         dqstats_inc(DQST_ALLOC_DQUOTS);
314 }
315
316 static inline void remove_inuse(struct dquot *dquot)
317 {
318         dqstats_dec(DQST_ALLOC_DQUOTS);
319         list_del(&dquot->dq_inuse);
320 }
321 /*
322  * End of list functions needing dq_list_lock
323  */
324
325 static void wait_on_dquot(struct dquot *dquot)
326 {
327         mutex_lock(&dquot->dq_lock);
328         mutex_unlock(&dquot->dq_lock);
329 }
330
331 static inline int dquot_dirty(struct dquot *dquot)
332 {
333         return test_bit(DQ_MOD_B, &dquot->dq_flags);
334 }
335
336 static inline int mark_dquot_dirty(struct dquot *dquot)
337 {
338         return dquot->dq_sb->dq_op->mark_dirty(dquot);
339 }
340
341 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */
342 int dquot_mark_dquot_dirty(struct dquot *dquot)
343 {
344         int ret = 1;
345
346         /* If quota is dirty already, we don't have to acquire dq_list_lock */
347         if (test_bit(DQ_MOD_B, &dquot->dq_flags))
348                 return 1;
349
350         spin_lock(&dq_list_lock);
351         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) {
352                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
353                                 info[dquot->dq_type].dqi_dirty_list);
354                 ret = 0;
355         }
356         spin_unlock(&dq_list_lock);
357         return ret;
358 }
359 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
360
361 /* Dirtify all the dquots - this can block when journalling */
362 static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
363 {
364         int ret, err, cnt;
365
366         ret = err = 0;
367         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
368                 if (dquot[cnt])
369                         /* Even in case of error we have to continue */
370                         ret = mark_dquot_dirty(dquot[cnt]);
371                 if (!err)
372                         err = ret;
373         }
374         return err;
375 }
376
377 static inline void dqput_all(struct dquot **dquot)
378 {
379         unsigned int cnt;
380
381         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
382                 dqput(dquot[cnt]);
383 }
384
385 /* This function needs dq_list_lock */
386 static inline int clear_dquot_dirty(struct dquot *dquot)
387 {
388         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
389                 return 0;
390         list_del_init(&dquot->dq_dirty);
391         return 1;
392 }
393
394 void mark_info_dirty(struct super_block *sb, int type)
395 {
396         set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
397 }
398 EXPORT_SYMBOL(mark_info_dirty);
399
400 /*
401  *      Read dquot from disk and alloc space for it
402  */
403
404 int dquot_acquire(struct dquot *dquot)
405 {
406         int ret = 0, ret2 = 0;
407         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
408
409         mutex_lock(&dquot->dq_lock);
410         mutex_lock(&dqopt->dqio_mutex);
411         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
412                 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
413         if (ret < 0)
414                 goto out_iolock;
415         set_bit(DQ_READ_B, &dquot->dq_flags);
416         /* Instantiate dquot if needed */
417         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
418                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
419                 /* Write the info if needed */
420                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
421                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
422                                                 dquot->dq_sb, dquot->dq_type);
423                 }
424                 if (ret < 0)
425                         goto out_iolock;
426                 if (ret2 < 0) {
427                         ret = ret2;
428                         goto out_iolock;
429                 }
430         }
431         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
432 out_iolock:
433         mutex_unlock(&dqopt->dqio_mutex);
434         mutex_unlock(&dquot->dq_lock);
435         return ret;
436 }
437 EXPORT_SYMBOL(dquot_acquire);
438
439 /*
440  *      Write dquot to disk
441  */
442 int dquot_commit(struct dquot *dquot)
443 {
444         int ret = 0;
445         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
446
447         mutex_lock(&dqopt->dqio_mutex);
448         spin_lock(&dq_list_lock);
449         if (!clear_dquot_dirty(dquot)) {
450                 spin_unlock(&dq_list_lock);
451                 goto out_sem;
452         }
453         spin_unlock(&dq_list_lock);
454         /* Inactive dquot can be only if there was error during read/init
455          * => we have better not writing it */
456         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
457                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
458         else
459                 ret = -EIO;
460 out_sem:
461         mutex_unlock(&dqopt->dqio_mutex);
462         return ret;
463 }
464 EXPORT_SYMBOL(dquot_commit);
465
466 /*
467  *      Release dquot
468  */
469 int dquot_release(struct dquot *dquot)
470 {
471         int ret = 0, ret2 = 0;
472         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
473
474         mutex_lock(&dquot->dq_lock);
475         /* Check whether we are not racing with some other dqget() */
476         if (atomic_read(&dquot->dq_count) > 1)
477                 goto out_dqlock;
478         mutex_lock(&dqopt->dqio_mutex);
479         if (dqopt->ops[dquot->dq_type]->release_dqblk) {
480                 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
481                 /* Write the info */
482                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
483                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
484                                                 dquot->dq_sb, dquot->dq_type);
485                 }
486                 if (ret >= 0)
487                         ret = ret2;
488         }
489         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
490         mutex_unlock(&dqopt->dqio_mutex);
491 out_dqlock:
492         mutex_unlock(&dquot->dq_lock);
493         return ret;
494 }
495 EXPORT_SYMBOL(dquot_release);
496
497 void dquot_destroy(struct dquot *dquot)
498 {
499         kmem_cache_free(dquot_cachep, dquot);
500 }
501 EXPORT_SYMBOL(dquot_destroy);
502
503 static inline void do_destroy_dquot(struct dquot *dquot)
504 {
505         dquot->dq_sb->dq_op->destroy_dquot(dquot);
506 }
507
508 /* Invalidate all dquots on the list. Note that this function is called after
509  * quota is disabled and pointers from inodes removed so there cannot be new
510  * quota users. There can still be some users of quotas due to inodes being
511  * just deleted or pruned by prune_icache() (those are not attached to any
512  * list) or parallel quotactl call. We have to wait for such users.
513  */
514 static void invalidate_dquots(struct super_block *sb, int type)
515 {
516         struct dquot *dquot, *tmp;
517
518 restart:
519         spin_lock(&dq_list_lock);
520         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
521                 if (dquot->dq_sb != sb)
522                         continue;
523                 if (dquot->dq_type != type)
524                         continue;
525                 /* Wait for dquot users */
526                 if (atomic_read(&dquot->dq_count)) {
527                         DEFINE_WAIT(wait);
528
529                         atomic_inc(&dquot->dq_count);
530                         prepare_to_wait(&dquot->dq_wait_unused, &wait,
531                                         TASK_UNINTERRUPTIBLE);
532                         spin_unlock(&dq_list_lock);
533                         /* Once dqput() wakes us up, we know it's time to free
534                          * the dquot.
535                          * IMPORTANT: we rely on the fact that there is always
536                          * at most one process waiting for dquot to free.
537                          * Otherwise dq_count would be > 1 and we would never
538                          * wake up.
539                          */
540                         if (atomic_read(&dquot->dq_count) > 1)
541                                 schedule();
542                         finish_wait(&dquot->dq_wait_unused, &wait);
543                         dqput(dquot);
544                         /* At this moment dquot() need not exist (it could be
545                          * reclaimed by prune_dqcache(). Hence we must
546                          * restart. */
547                         goto restart;
548                 }
549                 /*
550                  * Quota now has no users and it has been written on last
551                  * dqput()
552                  */
553                 remove_dquot_hash(dquot);
554                 remove_free_dquot(dquot);
555                 remove_inuse(dquot);
556                 do_destroy_dquot(dquot);
557         }
558         spin_unlock(&dq_list_lock);
559 }
560
561 /* Call callback for every active dquot on given filesystem */
562 int dquot_scan_active(struct super_block *sb,
563                       int (*fn)(struct dquot *dquot, unsigned long priv),
564                       unsigned long priv)
565 {
566         struct dquot *dquot, *old_dquot = NULL;
567         int ret = 0;
568
569         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
570         spin_lock(&dq_list_lock);
571         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
572                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
573                         continue;
574                 if (dquot->dq_sb != sb)
575                         continue;
576                 /* Now we have active dquot so we can just increase use count */
577                 atomic_inc(&dquot->dq_count);
578                 spin_unlock(&dq_list_lock);
579                 dqstats_inc(DQST_LOOKUPS);
580                 dqput(old_dquot);
581                 old_dquot = dquot;
582                 ret = fn(dquot, priv);
583                 if (ret < 0)
584                         goto out;
585                 spin_lock(&dq_list_lock);
586                 /* We are safe to continue now because our dquot could not
587                  * be moved out of the inuse list while we hold the reference */
588         }
589         spin_unlock(&dq_list_lock);
590 out:
591         dqput(old_dquot);
592         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
593         return ret;
594 }
595 EXPORT_SYMBOL(dquot_scan_active);
596
597 int dquot_quota_sync(struct super_block *sb, int type, int wait)
598 {
599         struct list_head *dirty;
600         struct dquot *dquot;
601         struct quota_info *dqopt = sb_dqopt(sb);
602         int cnt;
603
604         mutex_lock(&dqopt->dqonoff_mutex);
605         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
606                 if (type != -1 && cnt != type)
607                         continue;
608                 if (!sb_has_quota_active(sb, cnt))
609                         continue;
610                 spin_lock(&dq_list_lock);
611                 dirty = &dqopt->info[cnt].dqi_dirty_list;
612                 while (!list_empty(dirty)) {
613                         dquot = list_first_entry(dirty, struct dquot,
614                                                  dq_dirty);
615                         /* Dirty and inactive can be only bad dquot... */
616                         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
617                                 clear_dquot_dirty(dquot);
618                                 continue;
619                         }
620                         /* Now we have active dquot from which someone is
621                          * holding reference so we can safely just increase
622                          * use count */
623                         atomic_inc(&dquot->dq_count);
624                         spin_unlock(&dq_list_lock);
625                         dqstats_inc(DQST_LOOKUPS);
626                         sb->dq_op->write_dquot(dquot);
627                         dqput(dquot);
628                         spin_lock(&dq_list_lock);
629                 }
630                 spin_unlock(&dq_list_lock);
631         }
632
633         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
634                 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
635                     && info_dirty(&dqopt->info[cnt]))
636                         sb->dq_op->write_info(sb, cnt);
637         dqstats_inc(DQST_SYNCS);
638         mutex_unlock(&dqopt->dqonoff_mutex);
639
640         if (!wait || (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE))
641                 return 0;
642
643         /* This is not very clever (and fast) but currently I don't know about
644          * any other simple way of getting quota data to disk and we must get
645          * them there for userspace to be visible... */
646         if (sb->s_op->sync_fs)
647                 sb->s_op->sync_fs(sb, 1);
648         sync_blockdev(sb->s_bdev);
649
650         /*
651          * Now when everything is written we can discard the pagecache so
652          * that userspace sees the changes.
653          */
654         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
655         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
656                 if (type != -1 && cnt != type)
657                         continue;
658                 if (!sb_has_quota_active(sb, cnt))
659                         continue;
660                 mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex,
661                                   I_MUTEX_QUOTA);
662                 truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
663                 mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
664         }
665         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
666
667         return 0;
668 }
669 EXPORT_SYMBOL(dquot_quota_sync);
670
671 /* Free unused dquots from cache */
672 static void prune_dqcache(int count)
673 {
674         struct list_head *head;
675         struct dquot *dquot;
676
677         head = free_dquots.prev;
678         while (head != &free_dquots && count) {
679                 dquot = list_entry(head, struct dquot, dq_free);
680                 remove_dquot_hash(dquot);
681                 remove_free_dquot(dquot);
682                 remove_inuse(dquot);
683                 do_destroy_dquot(dquot);
684                 count--;
685                 head = free_dquots.prev;
686         }
687 }
688
689 /*
690  * This is called from kswapd when we think we need some
691  * more memory
692  */
693 static int shrink_dqcache_memory(struct shrinker *shrink,
694                                  struct shrink_control *sc)
695 {
696         int nr = sc->nr_to_scan;
697
698         if (nr) {
699                 spin_lock(&dq_list_lock);
700                 prune_dqcache(nr);
701                 spin_unlock(&dq_list_lock);
702         }
703         return ((unsigned)
704                 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])
705                 /100) * sysctl_vfs_cache_pressure;
706 }
707
708 static struct shrinker dqcache_shrinker = {
709         .shrink = shrink_dqcache_memory,
710         .seeks = DEFAULT_SEEKS,
711 };
712
713 /*
714  * Put reference to dquot
715  * NOTE: If you change this function please check whether dqput_blocks() works right...
716  */
717 void dqput(struct dquot *dquot)
718 {
719         int ret;
720
721         if (!dquot)
722                 return;
723 #ifdef CONFIG_QUOTA_DEBUG
724         if (!atomic_read(&dquot->dq_count)) {
725                 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d",
726                             quotatypes[dquot->dq_type], dquot->dq_id);
727                 BUG();
728         }
729 #endif
730         dqstats_inc(DQST_DROPS);
731 we_slept:
732         spin_lock(&dq_list_lock);
733         if (atomic_read(&dquot->dq_count) > 1) {
734                 /* We have more than one user... nothing to do */
735                 atomic_dec(&dquot->dq_count);
736                 /* Releasing dquot during quotaoff phase? */
737                 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
738                     atomic_read(&dquot->dq_count) == 1)
739                         wake_up(&dquot->dq_wait_unused);
740                 spin_unlock(&dq_list_lock);
741                 return;
742         }
743         /* Need to release dquot? */
744         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
745                 spin_unlock(&dq_list_lock);
746                 /* Commit dquot before releasing */
747                 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
748                 if (ret < 0) {
749                         quota_error(dquot->dq_sb, "Can't write quota structure"
750                                     " (error %d). Quota may get out of sync!",
751                                     ret);
752                         /*
753                          * We clear dirty bit anyway, so that we avoid
754                          * infinite loop here
755                          */
756                         spin_lock(&dq_list_lock);
757                         clear_dquot_dirty(dquot);
758                         spin_unlock(&dq_list_lock);
759                 }
760                 goto we_slept;
761         }
762         /* Clear flag in case dquot was inactive (something bad happened) */
763         clear_dquot_dirty(dquot);
764         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
765                 spin_unlock(&dq_list_lock);
766                 dquot->dq_sb->dq_op->release_dquot(dquot);
767                 goto we_slept;
768         }
769         atomic_dec(&dquot->dq_count);
770 #ifdef CONFIG_QUOTA_DEBUG
771         /* sanity check */
772         BUG_ON(!list_empty(&dquot->dq_free));
773 #endif
774         put_dquot_last(dquot);
775         spin_unlock(&dq_list_lock);
776 }
777 EXPORT_SYMBOL(dqput);
778
779 struct dquot *dquot_alloc(struct super_block *sb, int type)
780 {
781         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
782 }
783 EXPORT_SYMBOL(dquot_alloc);
784
785 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
786 {
787         struct dquot *dquot;
788
789         dquot = sb->dq_op->alloc_dquot(sb, type);
790         if(!dquot)
791                 return NULL;
792
793         mutex_init(&dquot->dq_lock);
794         INIT_LIST_HEAD(&dquot->dq_free);
795         INIT_LIST_HEAD(&dquot->dq_inuse);
796         INIT_HLIST_NODE(&dquot->dq_hash);
797         INIT_LIST_HEAD(&dquot->dq_dirty);
798         init_waitqueue_head(&dquot->dq_wait_unused);
799         dquot->dq_sb = sb;
800         dquot->dq_type = type;
801         atomic_set(&dquot->dq_count, 1);
802
803         return dquot;
804 }
805
806 /*
807  * Get reference to dquot
808  *
809  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
810  * destroying our dquot by:
811  *   a) checking for quota flags under dq_list_lock and
812  *   b) getting a reference to dquot before we release dq_list_lock
813  */
814 struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
815 {
816         unsigned int hashent = hashfn(sb, id, type);
817         struct dquot *dquot = NULL, *empty = NULL;
818
819         if (!sb_has_quota_active(sb, type))
820                 return NULL;
821 we_slept:
822         spin_lock(&dq_list_lock);
823         spin_lock(&dq_state_lock);
824         if (!sb_has_quota_active(sb, type)) {
825                 spin_unlock(&dq_state_lock);
826                 spin_unlock(&dq_list_lock);
827                 goto out;
828         }
829         spin_unlock(&dq_state_lock);
830
831         dquot = find_dquot(hashent, sb, id, type);
832         if (!dquot) {
833                 if (!empty) {
834                         spin_unlock(&dq_list_lock);
835                         empty = get_empty_dquot(sb, type);
836                         if (!empty)
837                                 schedule();     /* Try to wait for a moment... */
838                         goto we_slept;
839                 }
840                 dquot = empty;
841                 empty = NULL;
842                 dquot->dq_id = id;
843                 /* all dquots go on the inuse_list */
844                 put_inuse(dquot);
845                 /* hash it first so it can be found */
846                 insert_dquot_hash(dquot);
847                 spin_unlock(&dq_list_lock);
848                 dqstats_inc(DQST_LOOKUPS);
849         } else {
850                 if (!atomic_read(&dquot->dq_count))
851                         remove_free_dquot(dquot);
852                 atomic_inc(&dquot->dq_count);
853                 spin_unlock(&dq_list_lock);
854                 dqstats_inc(DQST_CACHE_HITS);
855                 dqstats_inc(DQST_LOOKUPS);
856         }
857         /* Wait for dq_lock - after this we know that either dquot_release() is
858          * already finished or it will be canceled due to dq_count > 1 test */
859         wait_on_dquot(dquot);
860         /* Read the dquot / allocate space in quota file */
861         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) &&
862             sb->dq_op->acquire_dquot(dquot) < 0) {
863                 dqput(dquot);
864                 dquot = NULL;
865                 goto out;
866         }
867 #ifdef CONFIG_QUOTA_DEBUG
868         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
869 #endif
870 out:
871         if (empty)
872                 do_destroy_dquot(empty);
873
874         return dquot;
875 }
876 EXPORT_SYMBOL(dqget);
877
878 static int dqinit_needed(struct inode *inode, int type)
879 {
880         int cnt;
881
882         if (IS_NOQUOTA(inode))
883                 return 0;
884         if (type != -1)
885                 return !inode->i_dquot[type];
886         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
887                 if (!inode->i_dquot[cnt])
888                         return 1;
889         return 0;
890 }
891
892 /* This routine is guarded by dqonoff_mutex mutex */
893 static void add_dquot_ref(struct super_block *sb, int type)
894 {
895         struct inode *inode, *old_inode = NULL;
896 #ifdef CONFIG_QUOTA_DEBUG
897         int reserved = 0;
898 #endif
899
900         spin_lock(&inode_sb_list_lock);
901         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
902                 spin_lock(&inode->i_lock);
903                 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
904                     !atomic_read(&inode->i_writecount) ||
905                     !dqinit_needed(inode, type)) {
906                         spin_unlock(&inode->i_lock);
907                         continue;
908                 }
909 #ifdef CONFIG_QUOTA_DEBUG
910                 if (unlikely(inode_get_rsv_space(inode) > 0))
911                         reserved = 1;
912 #endif
913                 __iget(inode);
914                 spin_unlock(&inode->i_lock);
915                 spin_unlock(&inode_sb_list_lock);
916
917                 iput(old_inode);
918                 __dquot_initialize(inode, type);
919
920                 /*
921                  * We hold a reference to 'inode' so it couldn't have been
922                  * removed from s_inodes list while we dropped the
923                  * inode_sb_list_lock We cannot iput the inode now as we can be
924                  * holding the last reference and we cannot iput it under
925                  * inode_sb_list_lock. So we keep the reference and iput it
926                  * later.
927                  */
928                 old_inode = inode;
929                 spin_lock(&inode_sb_list_lock);
930         }
931         spin_unlock(&inode_sb_list_lock);
932         iput(old_inode);
933
934 #ifdef CONFIG_QUOTA_DEBUG
935         if (reserved) {
936                 quota_error(sb, "Writes happened before quota was turned on "
937                         "thus quota information is probably inconsistent. "
938                         "Please run quotacheck(8)");
939         }
940 #endif
941 }
942
943 /*
944  * Return 0 if dqput() won't block.
945  * (note that 1 doesn't necessarily mean blocking)
946  */
947 static inline int dqput_blocks(struct dquot *dquot)
948 {
949         if (atomic_read(&dquot->dq_count) <= 1)
950                 return 1;
951         return 0;
952 }
953
954 /*
955  * Remove references to dquots from inode and add dquot to list for freeing
956  * if we have the last reference to dquot
957  * We can't race with anybody because we hold dqptr_sem for writing...
958  */
959 static int remove_inode_dquot_ref(struct inode *inode, int type,
960                                   struct list_head *tofree_head)
961 {
962         struct dquot *dquot = inode->i_dquot[type];
963
964         inode->i_dquot[type] = NULL;
965         if (dquot) {
966                 if (dqput_blocks(dquot)) {
967 #ifdef CONFIG_QUOTA_DEBUG
968                         if (atomic_read(&dquot->dq_count) != 1)
969                                 quota_error(inode->i_sb, "Adding dquot with "
970                                             "dq_count %d to dispose list",
971                                             atomic_read(&dquot->dq_count));
972 #endif
973                         spin_lock(&dq_list_lock);
974                         /* As dquot must have currently users it can't be on
975                          * the free list... */
976                         list_add(&dquot->dq_free, tofree_head);
977                         spin_unlock(&dq_list_lock);
978                         return 1;
979                 }
980                 else
981                         dqput(dquot);   /* We have guaranteed we won't block */
982         }
983         return 0;
984 }
985
986 /*
987  * Free list of dquots
988  * Dquots are removed from inodes and no new references can be got so we are
989  * the only ones holding reference
990  */
991 static void put_dquot_list(struct list_head *tofree_head)
992 {
993         struct list_head *act_head;
994         struct dquot *dquot;
995
996         act_head = tofree_head->next;
997         while (act_head != tofree_head) {
998                 dquot = list_entry(act_head, struct dquot, dq_free);
999                 act_head = act_head->next;
1000                 /* Remove dquot from the list so we won't have problems... */
1001                 list_del_init(&dquot->dq_free);
1002                 dqput(dquot);
1003         }
1004 }
1005
1006 static void remove_dquot_ref(struct super_block *sb, int type,
1007                 struct list_head *tofree_head)
1008 {
1009         struct inode *inode;
1010         int reserved = 0;
1011
1012         spin_lock(&inode_sb_list_lock);
1013         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
1014                 /*
1015                  *  We have to scan also I_NEW inodes because they can already
1016                  *  have quota pointer initialized. Luckily, we need to touch
1017                  *  only quota pointers and these have separate locking
1018                  *  (dqptr_sem).
1019                  */
1020                 if (!IS_NOQUOTA(inode)) {
1021                         if (unlikely(inode_get_rsv_space(inode) > 0))
1022                                 reserved = 1;
1023                         remove_inode_dquot_ref(inode, type, tofree_head);
1024                 }
1025         }
1026         spin_unlock(&inode_sb_list_lock);
1027 #ifdef CONFIG_QUOTA_DEBUG
1028         if (reserved) {
1029                 printk(KERN_WARNING "VFS (%s): Writes happened after quota"
1030                         " was disabled thus quota information is probably "
1031                         "inconsistent. Please run quotacheck(8).\n", sb->s_id);
1032         }
1033 #endif
1034 }
1035
1036 /* Gather all references from inodes and drop them */
1037 static void drop_dquot_ref(struct super_block *sb, int type)
1038 {
1039         LIST_HEAD(tofree_head);
1040
1041         if (sb->dq_op) {
1042                 down_write(&sb_dqopt(sb)->dqptr_sem);
1043                 remove_dquot_ref(sb, type, &tofree_head);
1044                 up_write(&sb_dqopt(sb)->dqptr_sem);
1045                 put_dquot_list(&tofree_head);
1046         }
1047 }
1048
1049 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
1050 {
1051         dquot->dq_dqb.dqb_curinodes += number;
1052 }
1053
1054 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
1055 {
1056         dquot->dq_dqb.dqb_curspace += number;
1057 }
1058
1059 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
1060 {
1061         dquot->dq_dqb.dqb_rsvspace += number;
1062 }
1063
1064 /*
1065  * Claim reserved quota space
1066  */
1067 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number)
1068 {
1069         if (dquot->dq_dqb.dqb_rsvspace < number) {
1070                 WARN_ON_ONCE(1);
1071                 number = dquot->dq_dqb.dqb_rsvspace;
1072         }
1073         dquot->dq_dqb.dqb_curspace += number;
1074         dquot->dq_dqb.dqb_rsvspace -= number;
1075 }
1076
1077 static inline
1078 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
1079 {
1080         if (dquot->dq_dqb.dqb_rsvspace >= number)
1081                 dquot->dq_dqb.dqb_rsvspace -= number;
1082         else {
1083                 WARN_ON_ONCE(1);
1084                 dquot->dq_dqb.dqb_rsvspace = 0;
1085         }
1086 }
1087
1088 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1089 {
1090         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1091             dquot->dq_dqb.dqb_curinodes >= number)
1092                 dquot->dq_dqb.dqb_curinodes -= number;
1093         else
1094                 dquot->dq_dqb.dqb_curinodes = 0;
1095         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1096                 dquot->dq_dqb.dqb_itime = (time_t) 0;
1097         clear_bit(DQ_INODES_B, &dquot->dq_flags);
1098 }
1099
1100 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1101 {
1102         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1103             dquot->dq_dqb.dqb_curspace >= number)
1104                 dquot->dq_dqb.dqb_curspace -= number;
1105         else
1106                 dquot->dq_dqb.dqb_curspace = 0;
1107         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1108                 dquot->dq_dqb.dqb_btime = (time_t) 0;
1109         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1110 }
1111
1112 static int warning_issued(struct dquot *dquot, const int warntype)
1113 {
1114         int flag = (warntype == QUOTA_NL_BHARDWARN ||
1115                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1116                 ((warntype == QUOTA_NL_IHARDWARN ||
1117                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1118
1119         if (!flag)
1120                 return 0;
1121         return test_and_set_bit(flag, &dquot->dq_flags);
1122 }
1123
1124 #ifdef CONFIG_PRINT_QUOTA_WARNING
1125 static int flag_print_warnings = 1;
1126
1127 static int need_print_warning(struct dquot *dquot)
1128 {
1129         if (!flag_print_warnings)
1130                 return 0;
1131
1132         switch (dquot->dq_type) {
1133                 case USRQUOTA:
1134                         return current_fsuid() == dquot->dq_id;
1135                 case GRPQUOTA:
1136                         return in_group_p(dquot->dq_id);
1137         }
1138         return 0;
1139 }
1140
1141 /* Print warning to user which exceeded quota */
1142 static void print_warning(struct dquot *dquot, const int warntype)
1143 {
1144         char *msg = NULL;
1145         struct tty_struct *tty;
1146
1147         if (warntype == QUOTA_NL_IHARDBELOW ||
1148             warntype == QUOTA_NL_ISOFTBELOW ||
1149             warntype == QUOTA_NL_BHARDBELOW ||
1150             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
1151                 return;
1152
1153         tty = get_current_tty();
1154         if (!tty)
1155                 return;
1156         tty_write_message(tty, dquot->dq_sb->s_id);
1157         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1158                 tty_write_message(tty, ": warning, ");
1159         else
1160                 tty_write_message(tty, ": write failed, ");
1161         tty_write_message(tty, quotatypes[dquot->dq_type]);
1162         switch (warntype) {
1163                 case QUOTA_NL_IHARDWARN:
1164                         msg = " file limit reached.\r\n";
1165                         break;
1166                 case QUOTA_NL_ISOFTLONGWARN:
1167                         msg = " file quota exceeded too long.\r\n";
1168                         break;
1169                 case QUOTA_NL_ISOFTWARN:
1170                         msg = " file quota exceeded.\r\n";
1171                         break;
1172                 case QUOTA_NL_BHARDWARN:
1173                         msg = " block limit reached.\r\n";
1174                         break;
1175                 case QUOTA_NL_BSOFTLONGWARN:
1176                         msg = " block quota exceeded too long.\r\n";
1177                         break;
1178                 case QUOTA_NL_BSOFTWARN:
1179                         msg = " block quota exceeded.\r\n";
1180                         break;
1181         }
1182         tty_write_message(tty, msg);
1183         tty_kref_put(tty);
1184 }
1185 #endif
1186
1187 /*
1188  * Write warnings to the console and send warning messages over netlink.
1189  *
1190  * Note that this function can sleep.
1191  */
1192 static void flush_warnings(struct dquot *const *dquots, char *warntype)
1193 {
1194         struct dquot *dq;
1195         int i;
1196
1197         for (i = 0; i < MAXQUOTAS; i++) {
1198                 dq = dquots[i];
1199                 if (dq && warntype[i] != QUOTA_NL_NOWARN &&
1200                     !warning_issued(dq, warntype[i])) {
1201 #ifdef CONFIG_PRINT_QUOTA_WARNING
1202                         print_warning(dq, warntype[i]);
1203 #endif
1204                         quota_send_warning(dq->dq_type, dq->dq_id,
1205                                            dq->dq_sb->s_dev, warntype[i]);
1206                 }
1207         }
1208 }
1209
1210 static int ignore_hardlimit(struct dquot *dquot)
1211 {
1212         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1213
1214         return capable(CAP_SYS_RESOURCE) &&
1215                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1216                 !(info->dqi_flags & V1_DQF_RSQUASH));
1217 }
1218
1219 /* needs dq_data_lock */
1220 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
1221 {
1222         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1223
1224         *warntype = QUOTA_NL_NOWARN;
1225         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1226             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1227                 return 0;
1228
1229         if (dquot->dq_dqb.dqb_ihardlimit &&
1230             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1231             !ignore_hardlimit(dquot)) {
1232                 *warntype = QUOTA_NL_IHARDWARN;
1233                 return -EDQUOT;
1234         }
1235
1236         if (dquot->dq_dqb.dqb_isoftlimit &&
1237             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1238             dquot->dq_dqb.dqb_itime &&
1239             get_seconds() >= dquot->dq_dqb.dqb_itime &&
1240             !ignore_hardlimit(dquot)) {
1241                 *warntype = QUOTA_NL_ISOFTLONGWARN;
1242                 return -EDQUOT;
1243         }
1244
1245         if (dquot->dq_dqb.dqb_isoftlimit &&
1246             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1247             dquot->dq_dqb.dqb_itime == 0) {
1248                 *warntype = QUOTA_NL_ISOFTWARN;
1249                 dquot->dq_dqb.dqb_itime = get_seconds() +
1250                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1251         }
1252
1253         return 0;
1254 }
1255
1256 /* needs dq_data_lock */
1257 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1258 {
1259         qsize_t tspace;
1260         struct super_block *sb = dquot->dq_sb;
1261
1262         *warntype = QUOTA_NL_NOWARN;
1263         if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
1264             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1265                 return 0;
1266
1267         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1268                 + space;
1269
1270         if (dquot->dq_dqb.dqb_bhardlimit &&
1271             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1272             !ignore_hardlimit(dquot)) {
1273                 if (!prealloc)
1274                         *warntype = QUOTA_NL_BHARDWARN;
1275                 return -EDQUOT;
1276         }
1277
1278         if (dquot->dq_dqb.dqb_bsoftlimit &&
1279             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1280             dquot->dq_dqb.dqb_btime &&
1281             get_seconds() >= dquot->dq_dqb.dqb_btime &&
1282             !ignore_hardlimit(dquot)) {
1283                 if (!prealloc)
1284                         *warntype = QUOTA_NL_BSOFTLONGWARN;
1285                 return -EDQUOT;
1286         }
1287
1288         if (dquot->dq_dqb.dqb_bsoftlimit &&
1289             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1290             dquot->dq_dqb.dqb_btime == 0) {
1291                 if (!prealloc) {
1292                         *warntype = QUOTA_NL_BSOFTWARN;
1293                         dquot->dq_dqb.dqb_btime = get_seconds() +
1294                             sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
1295                 }
1296                 else
1297                         /*
1298                          * We don't allow preallocation to exceed softlimit so exceeding will
1299                          * be always printed
1300                          */
1301                         return -EDQUOT;
1302         }
1303
1304         return 0;
1305 }
1306
1307 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1308 {
1309         qsize_t newinodes;
1310
1311         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1312             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1313             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
1314                 return QUOTA_NL_NOWARN;
1315
1316         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1317         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1318                 return QUOTA_NL_ISOFTBELOW;
1319         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1320             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1321                 return QUOTA_NL_IHARDBELOW;
1322         return QUOTA_NL_NOWARN;
1323 }
1324
1325 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1326 {
1327         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1328             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1329                 return QUOTA_NL_NOWARN;
1330
1331         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1332                 return QUOTA_NL_BSOFTBELOW;
1333         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1334             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1335                 return QUOTA_NL_BHARDBELOW;
1336         return QUOTA_NL_NOWARN;
1337 }
1338
1339 static int dquot_active(const struct inode *inode)
1340 {
1341         struct super_block *sb = inode->i_sb;
1342
1343         if (IS_NOQUOTA(inode))
1344                 return 0;
1345         return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
1346 }
1347
1348 /*
1349  * Initialize quota pointers in inode
1350  *
1351  * We do things in a bit complicated way but by that we avoid calling
1352  * dqget() and thus filesystem callbacks under dqptr_sem.
1353  *
1354  * It is better to call this function outside of any transaction as it
1355  * might need a lot of space in journal for dquot structure allocation.
1356  */
1357 static void __dquot_initialize(struct inode *inode, int type)
1358 {
1359         unsigned int id = 0;
1360         int cnt;
1361         struct dquot *got[MAXQUOTAS];
1362         struct super_block *sb = inode->i_sb;
1363         qsize_t rsv;
1364
1365         /* First test before acquiring mutex - solves deadlocks when we
1366          * re-enter the quota code and are already holding the mutex */
1367         if (!dquot_active(inode))
1368                 return;
1369
1370         /* First get references to structures we might need. */
1371         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1372                 got[cnt] = NULL;
1373                 if (type != -1 && cnt != type)
1374                         continue;
1375                 switch (cnt) {
1376                 case USRQUOTA:
1377                         id = inode->i_uid;
1378                         break;
1379                 case GRPQUOTA:
1380                         id = inode->i_gid;
1381                         break;
1382                 }
1383                 got[cnt] = dqget(sb, id, cnt);
1384         }
1385
1386         down_write(&sb_dqopt(sb)->dqptr_sem);
1387         if (IS_NOQUOTA(inode))
1388                 goto out_err;
1389         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1390                 if (type != -1 && cnt != type)
1391                         continue;
1392                 /* Avoid races with quotaoff() */
1393                 if (!sb_has_quota_active(sb, cnt))
1394                         continue;
1395                 /* We could race with quotaon or dqget() could have failed */
1396                 if (!got[cnt])
1397                         continue;
1398                 if (!inode->i_dquot[cnt]) {
1399                         inode->i_dquot[cnt] = got[cnt];
1400                         got[cnt] = NULL;
1401                         /*
1402                          * Make quota reservation system happy if someone
1403                          * did a write before quota was turned on
1404                          */
1405                         rsv = inode_get_rsv_space(inode);
1406                         if (unlikely(rsv))
1407                                 dquot_resv_space(inode->i_dquot[cnt], rsv);
1408                 }
1409         }
1410 out_err:
1411         up_write(&sb_dqopt(sb)->dqptr_sem);
1412         /* Drop unused references */
1413         dqput_all(got);
1414 }
1415
1416 void dquot_initialize(struct inode *inode)
1417 {
1418         __dquot_initialize(inode, -1);
1419 }
1420 EXPORT_SYMBOL(dquot_initialize);
1421
1422 /*
1423  *      Release all quotas referenced by inode
1424  */
1425 static void __dquot_drop(struct inode *inode)
1426 {
1427         int cnt;
1428         struct dquot *put[MAXQUOTAS];
1429
1430         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1431         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1432                 put[cnt] = inode->i_dquot[cnt];
1433                 inode->i_dquot[cnt] = NULL;
1434         }
1435         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1436         dqput_all(put);
1437 }
1438
1439 void dquot_drop(struct inode *inode)
1440 {
1441         int cnt;
1442
1443         if (IS_NOQUOTA(inode))
1444                 return;
1445
1446         /*
1447          * Test before calling to rule out calls from proc and such
1448          * where we are not allowed to block. Note that this is
1449          * actually reliable test even without the lock - the caller
1450          * must assure that nobody can come after the DQUOT_DROP and
1451          * add quota pointers back anyway.
1452          */
1453         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1454                 if (inode->i_dquot[cnt])
1455                         break;
1456         }
1457
1458         if (cnt < MAXQUOTAS)
1459                 __dquot_drop(inode);
1460 }
1461 EXPORT_SYMBOL(dquot_drop);
1462
1463 /*
1464  * inode_reserved_space is managed internally by quota, and protected by
1465  * i_lock similar to i_blocks+i_bytes.
1466  */
1467 static qsize_t *inode_reserved_space(struct inode * inode)
1468 {
1469         /* Filesystem must explicitly define it's own method in order to use
1470          * quota reservation interface */
1471         BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1472         return inode->i_sb->dq_op->get_reserved_space(inode);
1473 }
1474
1475 void inode_add_rsv_space(struct inode *inode, qsize_t number)
1476 {
1477         spin_lock(&inode->i_lock);
1478         *inode_reserved_space(inode) += number;
1479         spin_unlock(&inode->i_lock);
1480 }
1481 EXPORT_SYMBOL(inode_add_rsv_space);
1482
1483 void inode_claim_rsv_space(struct inode *inode, qsize_t number)
1484 {
1485         spin_lock(&inode->i_lock);
1486         *inode_reserved_space(inode) -= number;
1487         __inode_add_bytes(inode, number);
1488         spin_unlock(&inode->i_lock);
1489 }
1490 EXPORT_SYMBOL(inode_claim_rsv_space);
1491
1492 void inode_sub_rsv_space(struct inode *inode, qsize_t number)
1493 {
1494         spin_lock(&inode->i_lock);
1495         *inode_reserved_space(inode) -= number;
1496         spin_unlock(&inode->i_lock);
1497 }
1498 EXPORT_SYMBOL(inode_sub_rsv_space);
1499
1500 static qsize_t inode_get_rsv_space(struct inode *inode)
1501 {
1502         qsize_t ret;
1503
1504         if (!inode->i_sb->dq_op->get_reserved_space)
1505                 return 0;
1506         spin_lock(&inode->i_lock);
1507         ret = *inode_reserved_space(inode);
1508         spin_unlock(&inode->i_lock);
1509         return ret;
1510 }
1511
1512 static void inode_incr_space(struct inode *inode, qsize_t number,
1513                                 int reserve)
1514 {
1515         if (reserve)
1516                 inode_add_rsv_space(inode, number);
1517         else
1518                 inode_add_bytes(inode, number);
1519 }
1520
1521 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve)
1522 {
1523         if (reserve)
1524                 inode_sub_rsv_space(inode, number);
1525         else
1526                 inode_sub_bytes(inode, number);
1527 }
1528
1529 /*
1530  * This functions updates i_blocks+i_bytes fields and quota information
1531  * (together with appropriate checks).
1532  *
1533  * NOTE: We absolutely rely on the fact that caller dirties the inode
1534  * (usually helpers in quotaops.h care about this) and holds a handle for
1535  * the current transaction so that dquot write and inode write go into the
1536  * same transaction.
1537  */
1538
1539 /*
1540  * This operation can block, but only after everything is updated
1541  */
1542 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
1543 {
1544         int cnt, ret = 0;
1545         char warntype[MAXQUOTAS];
1546         int warn = flags & DQUOT_SPACE_WARN;
1547         int reserve = flags & DQUOT_SPACE_RESERVE;
1548         int nofail = flags & DQUOT_SPACE_NOFAIL;
1549
1550         /*
1551          * First test before acquiring mutex - solves deadlocks when we
1552          * re-enter the quota code and are already holding the mutex
1553          */
1554         if (!dquot_active(inode)) {
1555                 inode_incr_space(inode, number, reserve);
1556                 goto out;
1557         }
1558
1559         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1560         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1561                 warntype[cnt] = QUOTA_NL_NOWARN;
1562
1563         spin_lock(&dq_data_lock);
1564         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1565                 if (!inode->i_dquot[cnt])
1566                         continue;
1567                 ret = check_bdq(inode->i_dquot[cnt], number, !warn,
1568                                 warntype+cnt);
1569                 if (ret && !nofail) {
1570                         spin_unlock(&dq_data_lock);
1571                         goto out_flush_warn;
1572                 }
1573         }
1574         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1575                 if (!inode->i_dquot[cnt])
1576                         continue;
1577                 if (reserve)
1578                         dquot_resv_space(inode->i_dquot[cnt], number);
1579                 else
1580                         dquot_incr_space(inode->i_dquot[cnt], number);
1581         }
1582         inode_incr_space(inode, number, reserve);
1583         spin_unlock(&dq_data_lock);
1584
1585         if (reserve)
1586                 goto out_flush_warn;
1587         mark_all_dquot_dirty(inode->i_dquot);
1588 out_flush_warn:
1589         flush_warnings(inode->i_dquot, warntype);
1590         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1591 out:
1592         return ret;
1593 }
1594 EXPORT_SYMBOL(__dquot_alloc_space);
1595
1596 /*
1597  * This operation can block, but only after everything is updated
1598  */
1599 int dquot_alloc_inode(const struct inode *inode)
1600 {
1601         int cnt, ret = 0;
1602         char warntype[MAXQUOTAS];
1603
1604         /* First test before acquiring mutex - solves deadlocks when we
1605          * re-enter the quota code and are already holding the mutex */
1606         if (!dquot_active(inode))
1607                 return 0;
1608         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1609                 warntype[cnt] = QUOTA_NL_NOWARN;
1610         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1611         spin_lock(&dq_data_lock);
1612         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1613                 if (!inode->i_dquot[cnt])
1614                         continue;
1615                 ret = check_idq(inode->i_dquot[cnt], 1, warntype + cnt);
1616                 if (ret)
1617                         goto warn_put_all;
1618         }
1619
1620         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1621                 if (!inode->i_dquot[cnt])
1622                         continue;
1623                 dquot_incr_inodes(inode->i_dquot[cnt], 1);
1624         }
1625
1626 warn_put_all:
1627         spin_unlock(&dq_data_lock);
1628         if (ret == 0)
1629                 mark_all_dquot_dirty(inode->i_dquot);
1630         flush_warnings(inode->i_dquot, warntype);
1631         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1632         return ret;
1633 }
1634 EXPORT_SYMBOL(dquot_alloc_inode);
1635
1636 /*
1637  * Convert in-memory reserved quotas to real consumed quotas
1638  */
1639 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
1640 {
1641         int cnt;
1642
1643         if (!dquot_active(inode)) {
1644                 inode_claim_rsv_space(inode, number);
1645                 return 0;
1646         }
1647
1648         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1649         spin_lock(&dq_data_lock);
1650         /* Claim reserved quotas to allocated quotas */
1651         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1652                 if (inode->i_dquot[cnt])
1653                         dquot_claim_reserved_space(inode->i_dquot[cnt],
1654                                                         number);
1655         }
1656         /* Update inode bytes */
1657         inode_claim_rsv_space(inode, number);
1658         spin_unlock(&dq_data_lock);
1659         mark_all_dquot_dirty(inode->i_dquot);
1660         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1661         return 0;
1662 }
1663 EXPORT_SYMBOL(dquot_claim_space_nodirty);
1664
1665 /*
1666  * This operation can block, but only after everything is updated
1667  */
1668 void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
1669 {
1670         unsigned int cnt;
1671         char warntype[MAXQUOTAS];
1672         int reserve = flags & DQUOT_SPACE_RESERVE;
1673
1674         /* First test before acquiring mutex - solves deadlocks when we
1675          * re-enter the quota code and are already holding the mutex */
1676         if (!dquot_active(inode)) {
1677                 inode_decr_space(inode, number, reserve);
1678                 return;
1679         }
1680
1681         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1682         spin_lock(&dq_data_lock);
1683         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1684                 if (!inode->i_dquot[cnt])
1685                         continue;
1686                 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
1687                 if (reserve)
1688                         dquot_free_reserved_space(inode->i_dquot[cnt], number);
1689                 else
1690                         dquot_decr_space(inode->i_dquot[cnt], number);
1691         }
1692         inode_decr_space(inode, number, reserve);
1693         spin_unlock(&dq_data_lock);
1694
1695         if (reserve)
1696                 goto out_unlock;
1697         mark_all_dquot_dirty(inode->i_dquot);
1698 out_unlock:
1699         flush_warnings(inode->i_dquot, warntype);
1700         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1701 }
1702 EXPORT_SYMBOL(__dquot_free_space);
1703
1704 /*
1705  * This operation can block, but only after everything is updated
1706  */
1707 void dquot_free_inode(const struct inode *inode)
1708 {
1709         unsigned int cnt;
1710         char warntype[MAXQUOTAS];
1711
1712         /* First test before acquiring mutex - solves deadlocks when we
1713          * re-enter the quota code and are already holding the mutex */
1714         if (!dquot_active(inode))
1715                 return;
1716
1717         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1718         spin_lock(&dq_data_lock);
1719         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1720                 if (!inode->i_dquot[cnt])
1721                         continue;
1722                 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], 1);
1723                 dquot_decr_inodes(inode->i_dquot[cnt], 1);
1724         }
1725         spin_unlock(&dq_data_lock);
1726         mark_all_dquot_dirty(inode->i_dquot);
1727         flush_warnings(inode->i_dquot, warntype);
1728         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1729 }
1730 EXPORT_SYMBOL(dquot_free_inode);
1731
1732 /*
1733  * Transfer the number of inode and blocks from one diskquota to an other.
1734  * On success, dquot references in transfer_to are consumed and references
1735  * to original dquots that need to be released are placed there. On failure,
1736  * references are kept untouched.
1737  *
1738  * This operation can block, but only after everything is updated
1739  * A transaction must be started when entering this function.
1740  *
1741  */
1742 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
1743 {
1744         qsize_t space, cur_space;
1745         qsize_t rsv_space = 0;
1746         struct dquot *transfer_from[MAXQUOTAS] = {};
1747         int cnt, ret = 0;
1748         char is_valid[MAXQUOTAS] = {};
1749         char warntype_to[MAXQUOTAS];
1750         char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
1751
1752         /* First test before acquiring mutex - solves deadlocks when we
1753          * re-enter the quota code and are already holding the mutex */
1754         if (IS_NOQUOTA(inode))
1755                 return 0;
1756         /* Initialize the arrays */
1757         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1758                 warntype_to[cnt] = QUOTA_NL_NOWARN;
1759         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1760         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1761                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1762                 return 0;
1763         }
1764         spin_lock(&dq_data_lock);
1765         cur_space = inode_get_bytes(inode);
1766         rsv_space = inode_get_rsv_space(inode);
1767         space = cur_space + rsv_space;
1768         /* Build the transfer_from list and check the limits */
1769         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1770                 /*
1771                  * Skip changes for same uid or gid or for turned off quota-type.
1772                  */
1773                 if (!transfer_to[cnt])
1774                         continue;
1775                 /* Avoid races with quotaoff() */
1776                 if (!sb_has_quota_active(inode->i_sb, cnt))
1777                         continue;
1778                 is_valid[cnt] = 1;
1779                 transfer_from[cnt] = inode->i_dquot[cnt];
1780                 ret = check_idq(transfer_to[cnt], 1, warntype_to + cnt);
1781                 if (ret)
1782                         goto over_quota;
1783                 ret = check_bdq(transfer_to[cnt], space, 0, warntype_to + cnt);
1784                 if (ret)
1785                         goto over_quota;
1786         }
1787
1788         /*
1789          * Finally perform the needed transfer from transfer_from to transfer_to
1790          */
1791         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1792                 if (!is_valid[cnt])
1793                         continue;
1794                 /* Due to IO error we might not have transfer_from[] structure */
1795                 if (transfer_from[cnt]) {
1796                         warntype_from_inodes[cnt] =
1797                                 info_idq_free(transfer_from[cnt], 1);
1798                         warntype_from_space[cnt] =
1799                                 info_bdq_free(transfer_from[cnt], space);
1800                         dquot_decr_inodes(transfer_from[cnt], 1);
1801                         dquot_decr_space(transfer_from[cnt], cur_space);
1802                         dquot_free_reserved_space(transfer_from[cnt],
1803                                                   rsv_space);
1804                 }
1805
1806                 dquot_incr_inodes(transfer_to[cnt], 1);
1807                 dquot_incr_space(transfer_to[cnt], cur_space);
1808                 dquot_resv_space(transfer_to[cnt], rsv_space);
1809
1810                 inode->i_dquot[cnt] = transfer_to[cnt];
1811         }
1812         spin_unlock(&dq_data_lock);
1813         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1814
1815         mark_all_dquot_dirty(transfer_from);
1816         mark_all_dquot_dirty(transfer_to);
1817         flush_warnings(transfer_to, warntype_to);
1818         flush_warnings(transfer_from, warntype_from_inodes);
1819         flush_warnings(transfer_from, warntype_from_space);
1820         /* Pass back references to put */
1821         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1822                 if (is_valid[cnt])
1823                         transfer_to[cnt] = transfer_from[cnt];
1824         return 0;
1825 over_quota:
1826         spin_unlock(&dq_data_lock);
1827         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1828         flush_warnings(transfer_to, warntype_to);
1829         return ret;
1830 }
1831 EXPORT_SYMBOL(__dquot_transfer);
1832
1833 /* Wrapper for transferring ownership of an inode for uid/gid only
1834  * Called from FSXXX_setattr()
1835  */
1836 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1837 {
1838         struct dquot *transfer_to[MAXQUOTAS] = {};
1839         struct super_block *sb = inode->i_sb;
1840         int ret;
1841
1842         if (!dquot_active(inode))
1843                 return 0;
1844
1845         if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid)
1846                 transfer_to[USRQUOTA] = dqget(sb, iattr->ia_uid, USRQUOTA);
1847         if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)
1848                 transfer_to[GRPQUOTA] = dqget(sb, iattr->ia_gid, GRPQUOTA);
1849
1850         ret = __dquot_transfer(inode, transfer_to);
1851         dqput_all(transfer_to);
1852         return ret;
1853 }
1854 EXPORT_SYMBOL(dquot_transfer);
1855
1856 /*
1857  * Write info of quota file to disk
1858  */
1859 int dquot_commit_info(struct super_block *sb, int type)
1860 {
1861         int ret;
1862         struct quota_info *dqopt = sb_dqopt(sb);
1863
1864         mutex_lock(&dqopt->dqio_mutex);
1865         ret = dqopt->ops[type]->write_file_info(sb, type);
1866         mutex_unlock(&dqopt->dqio_mutex);
1867         return ret;
1868 }
1869 EXPORT_SYMBOL(dquot_commit_info);
1870
1871 /*
1872  * Definitions of diskquota operations.
1873  */
1874 const struct dquot_operations dquot_operations = {
1875         .write_dquot    = dquot_commit,
1876         .acquire_dquot  = dquot_acquire,
1877         .release_dquot  = dquot_release,
1878         .mark_dirty     = dquot_mark_dquot_dirty,
1879         .write_info     = dquot_commit_info,
1880         .alloc_dquot    = dquot_alloc,
1881         .destroy_dquot  = dquot_destroy,
1882 };
1883 EXPORT_SYMBOL(dquot_operations);
1884
1885 /*
1886  * Generic helper for ->open on filesystems supporting disk quotas.
1887  */
1888 int dquot_file_open(struct inode *inode, struct file *file)
1889 {
1890         int error;
1891
1892         error = generic_file_open(inode, file);
1893         if (!error && (file->f_mode & FMODE_WRITE))
1894                 dquot_initialize(inode);
1895         return error;
1896 }
1897 EXPORT_SYMBOL(dquot_file_open);
1898
1899 /*
1900  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1901  */
1902 int dquot_disable(struct super_block *sb, int type, unsigned int flags)
1903 {
1904         int cnt, ret = 0;
1905         struct quota_info *dqopt = sb_dqopt(sb);
1906         struct inode *toputinode[MAXQUOTAS];
1907
1908         /* Cannot turn off usage accounting without turning off limits, or
1909          * suspend quotas and simultaneously turn quotas off. */
1910         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1911             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1912             DQUOT_USAGE_ENABLED)))
1913                 return -EINVAL;
1914
1915         /* We need to serialize quota_off() for device */
1916         mutex_lock(&dqopt->dqonoff_mutex);
1917
1918         /*
1919          * Skip everything if there's nothing to do. We have to do this because
1920          * sometimes we are called when fill_super() failed and calling
1921          * sync_fs() in such cases does no good.
1922          */
1923         if (!sb_any_quota_loaded(sb)) {
1924                 mutex_unlock(&dqopt->dqonoff_mutex);
1925                 return 0;
1926         }
1927         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1928                 toputinode[cnt] = NULL;
1929                 if (type != -1 && cnt != type)
1930                         continue;
1931                 if (!sb_has_quota_loaded(sb, cnt))
1932                         continue;
1933
1934                 if (flags & DQUOT_SUSPENDED) {
1935                         spin_lock(&dq_state_lock);
1936                         dqopt->flags |=
1937                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1938                         spin_unlock(&dq_state_lock);
1939                 } else {
1940                         spin_lock(&dq_state_lock);
1941                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
1942                         /* Turning off suspended quotas? */
1943                         if (!sb_has_quota_loaded(sb, cnt) &&
1944                             sb_has_quota_suspended(sb, cnt)) {
1945                                 dqopt->flags &= ~dquot_state_flag(
1946                                                         DQUOT_SUSPENDED, cnt);
1947                                 spin_unlock(&dq_state_lock);
1948                                 iput(dqopt->files[cnt]);
1949                                 dqopt->files[cnt] = NULL;
1950                                 continue;
1951                         }
1952                         spin_unlock(&dq_state_lock);
1953                 }
1954
1955                 /* We still have to keep quota loaded? */
1956                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
1957                         continue;
1958
1959                 /* Note: these are blocking operations */
1960                 drop_dquot_ref(sb, cnt);
1961                 invalidate_dquots(sb, cnt);
1962                 /*
1963                  * Now all dquots should be invalidated, all writes done so we
1964                  * should be only users of the info. No locks needed.
1965                  */
1966                 if (info_dirty(&dqopt->info[cnt]))
1967                         sb->dq_op->write_info(sb, cnt);
1968                 if (dqopt->ops[cnt]->free_file_info)
1969                         dqopt->ops[cnt]->free_file_info(sb, cnt);
1970                 put_quota_format(dqopt->info[cnt].dqi_format);
1971
1972                 toputinode[cnt] = dqopt->files[cnt];
1973                 if (!sb_has_quota_loaded(sb, cnt))
1974                         dqopt->files[cnt] = NULL;
1975                 dqopt->info[cnt].dqi_flags = 0;
1976                 dqopt->info[cnt].dqi_igrace = 0;
1977                 dqopt->info[cnt].dqi_bgrace = 0;
1978                 dqopt->ops[cnt] = NULL;
1979         }
1980         mutex_unlock(&dqopt->dqonoff_mutex);
1981
1982         /* Skip syncing and setting flags if quota files are hidden */
1983         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
1984                 goto put_inodes;
1985
1986         /* Sync the superblock so that buffers with quota data are written to
1987          * disk (and so userspace sees correct data afterwards). */
1988         if (sb->s_op->sync_fs)
1989                 sb->s_op->sync_fs(sb, 1);
1990         sync_blockdev(sb->s_bdev);
1991         /* Now the quota files are just ordinary files and we can set the
1992          * inode flags back. Moreover we discard the pagecache so that
1993          * userspace sees the writes we did bypassing the pagecache. We
1994          * must also discard the blockdev buffers so that we see the
1995          * changes done by userspace on the next quotaon() */
1996         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1997                 if (toputinode[cnt]) {
1998                         mutex_lock(&dqopt->dqonoff_mutex);
1999                         /* If quota was reenabled in the meantime, we have
2000                          * nothing to do */
2001                         if (!sb_has_quota_loaded(sb, cnt)) {
2002                                 mutex_lock_nested(&toputinode[cnt]->i_mutex,
2003                                                   I_MUTEX_QUOTA);
2004                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
2005                                   S_NOATIME | S_NOQUOTA);
2006                                 truncate_inode_pages(&toputinode[cnt]->i_data,
2007                                                      0);
2008                                 mutex_unlock(&toputinode[cnt]->i_mutex);
2009                                 mark_inode_dirty_sync(toputinode[cnt]);
2010                         }
2011                         mutex_unlock(&dqopt->dqonoff_mutex);
2012                 }
2013         if (sb->s_bdev)
2014                 invalidate_bdev(sb->s_bdev);
2015 put_inodes:
2016         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2017                 if (toputinode[cnt]) {
2018                         /* On remount RO, we keep the inode pointer so that we
2019                          * can reenable quota on the subsequent remount RW. We
2020                          * have to check 'flags' variable and not use sb_has_
2021                          * function because another quotaon / quotaoff could
2022                          * change global state before we got here. We refuse
2023                          * to suspend quotas when there is pending delete on
2024                          * the quota file... */
2025                         if (!(flags & DQUOT_SUSPENDED))
2026                                 iput(toputinode[cnt]);
2027                         else if (!toputinode[cnt]->i_nlink)
2028                                 ret = -EBUSY;
2029                 }
2030         return ret;
2031 }
2032 EXPORT_SYMBOL(dquot_disable);
2033
2034 int dquot_quota_off(struct super_block *sb, int type)
2035 {
2036         return dquot_disable(sb, type,
2037                              DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2038 }
2039 EXPORT_SYMBOL(dquot_quota_off);
2040
2041 /*
2042  *      Turn quotas on on a device
2043  */
2044
2045 /*
2046  * Helper function to turn quotas on when we already have the inode of
2047  * quota file and no quota information is loaded.
2048  */
2049 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2050         unsigned int flags)
2051 {
2052         struct quota_format_type *fmt = find_quota_format(format_id);
2053         struct super_block *sb = inode->i_sb;
2054         struct quota_info *dqopt = sb_dqopt(sb);
2055         int error;
2056         int oldflags = -1;
2057
2058         if (!fmt)
2059                 return -ESRCH;
2060         if (!S_ISREG(inode->i_mode)) {
2061                 error = -EACCES;
2062                 goto out_fmt;
2063         }
2064         if (IS_RDONLY(inode)) {
2065                 error = -EROFS;
2066                 goto out_fmt;
2067         }
2068         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
2069                 error = -EINVAL;
2070                 goto out_fmt;
2071         }
2072         /* Usage always has to be set... */
2073         if (!(flags & DQUOT_USAGE_ENABLED)) {
2074                 error = -EINVAL;
2075                 goto out_fmt;
2076         }
2077
2078         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2079                 /* As we bypass the pagecache we must now flush all the
2080                  * dirty data and invalidate caches so that kernel sees
2081                  * changes from userspace. It is not enough to just flush
2082                  * the quota file since if blocksize < pagesize, invalidation
2083                  * of the cache could fail because of other unrelated dirty
2084                  * data */
2085                 sync_filesystem(sb);
2086                 invalidate_bdev(sb->s_bdev);
2087         }
2088         mutex_lock(&dqopt->dqonoff_mutex);
2089         if (sb_has_quota_loaded(sb, type)) {
2090                 error = -EBUSY;
2091                 goto out_lock;
2092         }
2093
2094         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2095                 /* We don't want quota and atime on quota files (deadlocks
2096                  * possible) Also nobody should write to the file - we use
2097                  * special IO operations which ignore the immutable bit. */
2098                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2099                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2100                                              S_NOQUOTA);
2101                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2102                 mutex_unlock(&inode->i_mutex);
2103                 /*
2104                  * When S_NOQUOTA is set, remove dquot references as no more
2105                  * references can be added
2106                  */
2107                 __dquot_drop(inode);
2108         }
2109
2110         error = -EIO;
2111         dqopt->files[type] = igrab(inode);
2112         if (!dqopt->files[type])
2113                 goto out_lock;
2114         error = -EINVAL;
2115         if (!fmt->qf_ops->check_quota_file(sb, type))
2116                 goto out_file_init;
2117
2118         dqopt->ops[type] = fmt->qf_ops;
2119         dqopt->info[type].dqi_format = fmt;
2120         dqopt->info[type].dqi_fmt_id = format_id;
2121         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2122         mutex_lock(&dqopt->dqio_mutex);
2123         error = dqopt->ops[type]->read_file_info(sb, type);
2124         if (error < 0) {
2125                 mutex_unlock(&dqopt->dqio_mutex);
2126                 goto out_file_init;
2127         }
2128         mutex_unlock(&dqopt->dqio_mutex);
2129         spin_lock(&dq_state_lock);
2130         dqopt->flags |= dquot_state_flag(flags, type);
2131         spin_unlock(&dq_state_lock);
2132
2133         add_dquot_ref(sb, type);
2134         mutex_unlock(&dqopt->dqonoff_mutex);
2135
2136         return 0;
2137
2138 out_file_init:
2139         dqopt->files[type] = NULL;
2140         iput(inode);
2141 out_lock:
2142         if (oldflags != -1) {
2143                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2144                 /* Set the flags back (in the case of accidental quotaon()
2145                  * on a wrong file we don't want to mess up the flags) */
2146                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2147                 inode->i_flags |= oldflags;
2148                 mutex_unlock(&inode->i_mutex);
2149         }
2150         mutex_unlock(&dqopt->dqonoff_mutex);
2151 out_fmt:
2152         put_quota_format(fmt);
2153
2154         return error; 
2155 }
2156
2157 /* Reenable quotas on remount RW */
2158 int dquot_resume(struct super_block *sb, int type)
2159 {
2160         struct quota_info *dqopt = sb_dqopt(sb);
2161         struct inode *inode;
2162         int ret = 0, cnt;
2163         unsigned int flags;
2164
2165         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2166                 if (type != -1 && cnt != type)
2167                         continue;
2168
2169                 mutex_lock(&dqopt->dqonoff_mutex);
2170                 if (!sb_has_quota_suspended(sb, cnt)) {
2171                         mutex_unlock(&dqopt->dqonoff_mutex);
2172                         continue;
2173                 }
2174                 inode = dqopt->files[cnt];
2175                 dqopt->files[cnt] = NULL;
2176                 spin_lock(&dq_state_lock);
2177                 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2178                                                         DQUOT_LIMITS_ENABLED,
2179                                                         cnt);
2180                 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
2181                 spin_unlock(&dq_state_lock);
2182                 mutex_unlock(&dqopt->dqonoff_mutex);
2183
2184                 flags = dquot_generic_flag(flags, cnt);
2185                 ret = vfs_load_quota_inode(inode, cnt,
2186                                 dqopt->info[cnt].dqi_fmt_id, flags);
2187                 iput(inode);
2188         }
2189
2190         return ret;
2191 }
2192 EXPORT_SYMBOL(dquot_resume);
2193
2194 int dquot_quota_on(struct super_block *sb, int type, int format_id,
2195                    struct path *path)
2196 {
2197         int error = security_quota_on(path->dentry);
2198         if (error)
2199                 return error;
2200         /* Quota file not on the same filesystem? */
2201         if (path->mnt->mnt_sb != sb)
2202                 error = -EXDEV;
2203         else
2204                 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2205                                              format_id, DQUOT_USAGE_ENABLED |
2206                                              DQUOT_LIMITS_ENABLED);
2207         return error;
2208 }
2209 EXPORT_SYMBOL(dquot_quota_on);
2210
2211 /*
2212  * More powerful function for turning on quotas allowing setting
2213  * of individual quota flags
2214  */
2215 int dquot_enable(struct inode *inode, int type, int format_id,
2216                  unsigned int flags)
2217 {
2218         int ret = 0;
2219         struct super_block *sb = inode->i_sb;
2220         struct quota_info *dqopt = sb_dqopt(sb);
2221
2222         /* Just unsuspend quotas? */
2223         BUG_ON(flags & DQUOT_SUSPENDED);
2224
2225         if (!flags)
2226                 return 0;
2227         /* Just updating flags needed? */
2228         if (sb_has_quota_loaded(sb, type)) {
2229                 mutex_lock(&dqopt->dqonoff_mutex);
2230                 /* Now do a reliable test... */
2231                 if (!sb_has_quota_loaded(sb, type)) {
2232                         mutex_unlock(&dqopt->dqonoff_mutex);
2233                         goto load_quota;
2234                 }
2235                 if (flags & DQUOT_USAGE_ENABLED &&
2236                     sb_has_quota_usage_enabled(sb, type)) {
2237                         ret = -EBUSY;
2238                         goto out_lock;
2239                 }
2240                 if (flags & DQUOT_LIMITS_ENABLED &&
2241                     sb_has_quota_limits_enabled(sb, type)) {
2242                         ret = -EBUSY;
2243                         goto out_lock;
2244                 }
2245                 spin_lock(&dq_state_lock);
2246                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2247                 spin_unlock(&dq_state_lock);
2248 out_lock:
2249                 mutex_unlock(&dqopt->dqonoff_mutex);
2250                 return ret;
2251         }
2252
2253 load_quota:
2254         return vfs_load_quota_inode(inode, type, format_id, flags);
2255 }
2256 EXPORT_SYMBOL(dquot_enable);
2257
2258 /*
2259  * This function is used when filesystem needs to initialize quotas
2260  * during mount time.
2261  */
2262 int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
2263                 int format_id, int type)
2264 {
2265         struct dentry *dentry;
2266         int error;
2267
2268         mutex_lock(&sb->s_root->d_inode->i_mutex);
2269         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2270         mutex_unlock(&sb->s_root->d_inode->i_mutex);
2271         if (IS_ERR(dentry))
2272                 return PTR_ERR(dentry);
2273
2274         if (!dentry->d_inode) {
2275                 error = -ENOENT;
2276                 goto out;
2277         }
2278
2279         error = security_quota_on(dentry);
2280         if (!error)
2281                 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2282                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2283
2284 out:
2285         dput(dentry);
2286         return error;
2287 }
2288 EXPORT_SYMBOL(dquot_quota_on_mount);
2289
2290 static inline qsize_t qbtos(qsize_t blocks)
2291 {
2292         return blocks << QIF_DQBLKSIZE_BITS;
2293 }
2294
2295 static inline qsize_t stoqb(qsize_t space)
2296 {
2297         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2298 }
2299
2300 /* Generic routine for getting common part of quota structure */
2301 static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
2302 {
2303         struct mem_dqblk *dm = &dquot->dq_dqb;
2304
2305         memset(di, 0, sizeof(*di));
2306         di->d_version = FS_DQUOT_VERSION;
2307         di->d_flags = dquot->dq_type == USRQUOTA ?
2308                         FS_USER_QUOTA : FS_GROUP_QUOTA;
2309         di->d_id = dquot->dq_id;
2310
2311         spin_lock(&dq_data_lock);
2312         di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit);
2313         di->d_blk_softlimit = stoqb(dm->dqb_bsoftlimit);
2314         di->d_ino_hardlimit = dm->dqb_ihardlimit;
2315         di->d_ino_softlimit = dm->dqb_isoftlimit;
2316         di->d_bcount = dm->dqb_curspace + dm->dqb_rsvspace;
2317         di->d_icount = dm->dqb_curinodes;
2318         di->d_btimer = dm->dqb_btime;
2319         di->d_itimer = dm->dqb_itime;
2320         spin_unlock(&dq_data_lock);
2321 }
2322
2323 int dquot_get_dqblk(struct super_block *sb, int type, qid_t id,
2324                     struct fs_disk_quota *di)
2325 {
2326         struct dquot *dquot;
2327
2328         dquot = dqget(sb, id, type);
2329         if (!dquot)
2330                 return -ESRCH;
2331         do_get_dqblk(dquot, di);
2332         dqput(dquot);
2333
2334         return 0;
2335 }
2336 EXPORT_SYMBOL(dquot_get_dqblk);
2337
2338 #define VFS_FS_DQ_MASK \
2339         (FS_DQ_BCOUNT | FS_DQ_BSOFT | FS_DQ_BHARD | \
2340          FS_DQ_ICOUNT | FS_DQ_ISOFT | FS_DQ_IHARD | \
2341          FS_DQ_BTIMER | FS_DQ_ITIMER)
2342
2343 /* Generic routine for setting common part of quota structure */
2344 static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
2345 {
2346         struct mem_dqblk *dm = &dquot->dq_dqb;
2347         int check_blim = 0, check_ilim = 0;
2348         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2349
2350         if (di->d_fieldmask & ~VFS_FS_DQ_MASK)
2351                 return -EINVAL;
2352
2353         if (((di->d_fieldmask & FS_DQ_BSOFT) &&
2354              (di->d_blk_softlimit > dqi->dqi_maxblimit)) ||
2355             ((di->d_fieldmask & FS_DQ_BHARD) &&
2356              (di->d_blk_hardlimit > dqi->dqi_maxblimit)) ||
2357             ((di->d_fieldmask & FS_DQ_ISOFT) &&
2358              (di->d_ino_softlimit > dqi->dqi_maxilimit)) ||
2359             ((di->d_fieldmask & FS_DQ_IHARD) &&
2360              (di->d_ino_hardlimit > dqi->dqi_maxilimit)))
2361                 return -ERANGE;
2362
2363         spin_lock(&dq_data_lock);
2364         if (di->d_fieldmask & FS_DQ_BCOUNT) {
2365                 dm->dqb_curspace = di->d_bcount - dm->dqb_rsvspace;
2366                 check_blim = 1;
2367                 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2368         }
2369
2370         if (di->d_fieldmask & FS_DQ_BSOFT)
2371                 dm->dqb_bsoftlimit = qbtos(di->d_blk_softlimit);
2372         if (di->d_fieldmask & FS_DQ_BHARD)
2373                 dm->dqb_bhardlimit = qbtos(di->d_blk_hardlimit);
2374         if (di->d_fieldmask & (FS_DQ_BSOFT | FS_DQ_BHARD)) {
2375                 check_blim = 1;
2376                 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2377         }
2378
2379         if (di->d_fieldmask & FS_DQ_ICOUNT) {
2380                 dm->dqb_curinodes = di->d_icount;
2381                 check_ilim = 1;
2382                 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2383         }
2384
2385         if (di->d_fieldmask & FS_DQ_ISOFT)
2386                 dm->dqb_isoftlimit = di->d_ino_softlimit;
2387         if (di->d_fieldmask & FS_DQ_IHARD)
2388                 dm->dqb_ihardlimit = di->d_ino_hardlimit;
2389         if (di->d_fieldmask & (FS_DQ_ISOFT | FS_DQ_IHARD)) {
2390                 check_ilim = 1;
2391                 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2392         }
2393
2394         if (di->d_fieldmask & FS_DQ_BTIMER) {
2395                 dm->dqb_btime = di->d_btimer;
2396                 check_blim = 1;
2397                 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2398         }
2399
2400         if (di->d_fieldmask & FS_DQ_ITIMER) {
2401                 dm->dqb_itime = di->d_itimer;
2402                 check_ilim = 1;
2403                 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2404         }
2405
2406         if (check_blim) {
2407                 if (!dm->dqb_bsoftlimit ||
2408                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2409                         dm->dqb_btime = 0;
2410                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2411                 } else if (!(di->d_fieldmask & FS_DQ_BTIMER))
2412                         /* Set grace only if user hasn't provided his own... */
2413                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2414         }
2415         if (check_ilim) {
2416                 if (!dm->dqb_isoftlimit ||
2417                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2418                         dm->dqb_itime = 0;
2419                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2420                 } else if (!(di->d_fieldmask & FS_DQ_ITIMER))
2421                         /* Set grace only if user hasn't provided his own... */
2422                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2423         }
2424         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2425             dm->dqb_isoftlimit)
2426                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2427         else
2428                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2429         spin_unlock(&dq_data_lock);
2430         mark_dquot_dirty(dquot);
2431
2432         return 0;
2433 }
2434
2435 int dquot_set_dqblk(struct super_block *sb, int type, qid_t id,
2436                   struct fs_disk_quota *di)
2437 {
2438         struct dquot *dquot;
2439         int rc;
2440
2441         dquot = dqget(sb, id, type);
2442         if (!dquot) {
2443                 rc = -ESRCH;
2444                 goto out;
2445         }
2446         rc = do_set_dqblk(dquot, di);
2447         dqput(dquot);
2448 out:
2449         return rc;
2450 }
2451 EXPORT_SYMBOL(dquot_set_dqblk);
2452
2453 /* Generic routine for getting common part of quota file information */
2454 int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2455 {
2456         struct mem_dqinfo *mi;
2457   
2458         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2459         if (!sb_has_quota_active(sb, type)) {
2460                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2461                 return -ESRCH;
2462         }
2463         mi = sb_dqopt(sb)->info + type;
2464         spin_lock(&dq_data_lock);
2465         ii->dqi_bgrace = mi->dqi_bgrace;
2466         ii->dqi_igrace = mi->dqi_igrace;
2467         ii->dqi_flags = mi->dqi_flags & DQF_MASK;
2468         ii->dqi_valid = IIF_ALL;
2469         spin_unlock(&dq_data_lock);
2470         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2471         return 0;
2472 }
2473 EXPORT_SYMBOL(dquot_get_dqinfo);
2474
2475 /* Generic routine for setting common part of quota file information */
2476 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2477 {
2478         struct mem_dqinfo *mi;
2479         int err = 0;
2480
2481         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2482         if (!sb_has_quota_active(sb, type)) {
2483                 err = -ESRCH;
2484                 goto out;
2485         }
2486         mi = sb_dqopt(sb)->info + type;
2487         spin_lock(&dq_data_lock);
2488         if (ii->dqi_valid & IIF_BGRACE)
2489                 mi->dqi_bgrace = ii->dqi_bgrace;
2490         if (ii->dqi_valid & IIF_IGRACE)
2491                 mi->dqi_igrace = ii->dqi_igrace;
2492         if (ii->dqi_valid & IIF_FLAGS)
2493                 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) |
2494                                 (ii->dqi_flags & DQF_MASK);
2495         spin_unlock(&dq_data_lock);
2496         mark_info_dirty(sb, type);
2497         /* Force write to disk */
2498         sb->dq_op->write_info(sb, type);
2499 out:
2500         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2501         return err;
2502 }
2503 EXPORT_SYMBOL(dquot_set_dqinfo);
2504
2505 const struct quotactl_ops dquot_quotactl_ops = {
2506         .quota_on       = dquot_quota_on,
2507         .quota_off      = dquot_quota_off,
2508         .quota_sync     = dquot_quota_sync,
2509         .get_info       = dquot_get_dqinfo,
2510         .set_info       = dquot_set_dqinfo,
2511         .get_dqblk      = dquot_get_dqblk,
2512         .set_dqblk      = dquot_set_dqblk
2513 };
2514 EXPORT_SYMBOL(dquot_quotactl_ops);
2515
2516 static int do_proc_dqstats(struct ctl_table *table, int write,
2517                      void __user *buffer, size_t *lenp, loff_t *ppos)
2518 {
2519         unsigned int type = (int *)table->data - dqstats.stat;
2520
2521         /* Update global table */
2522         dqstats.stat[type] =
2523                         percpu_counter_sum_positive(&dqstats.counter[type]);
2524         return proc_dointvec(table, write, buffer, lenp, ppos);
2525 }
2526
2527 static ctl_table fs_dqstats_table[] = {
2528         {
2529                 .procname       = "lookups",
2530                 .data           = &dqstats.stat[DQST_LOOKUPS],
2531                 .maxlen         = sizeof(int),
2532                 .mode           = 0444,
2533                 .proc_handler   = do_proc_dqstats,
2534         },
2535         {
2536                 .procname       = "drops",
2537                 .data           = &dqstats.stat[DQST_DROPS],
2538                 .maxlen         = sizeof(int),
2539                 .mode           = 0444,
2540                 .proc_handler   = do_proc_dqstats,
2541         },
2542         {
2543                 .procname       = "reads",
2544                 .data           = &dqstats.stat[DQST_READS],
2545                 .maxlen         = sizeof(int),
2546                 .mode           = 0444,
2547                 .proc_handler   = do_proc_dqstats,
2548         },
2549         {
2550                 .procname       = "writes",
2551                 .data           = &dqstats.stat[DQST_WRITES],
2552                 .maxlen         = sizeof(int),
2553                 .mode           = 0444,
2554                 .proc_handler   = do_proc_dqstats,
2555         },
2556         {
2557                 .procname       = "cache_hits",
2558                 .data           = &dqstats.stat[DQST_CACHE_HITS],
2559                 .maxlen         = sizeof(int),
2560                 .mode           = 0444,
2561                 .proc_handler   = do_proc_dqstats,
2562         },
2563         {
2564                 .procname       = "allocated_dquots",
2565                 .data           = &dqstats.stat[DQST_ALLOC_DQUOTS],
2566                 .maxlen         = sizeof(int),
2567                 .mode           = 0444,
2568                 .proc_handler   = do_proc_dqstats,
2569         },
2570         {
2571                 .procname       = "free_dquots",
2572                 .data           = &dqstats.stat[DQST_FREE_DQUOTS],
2573                 .maxlen         = sizeof(int),
2574                 .mode           = 0444,
2575                 .proc_handler   = do_proc_dqstats,
2576         },
2577         {
2578                 .procname       = "syncs",
2579                 .data           = &dqstats.stat[DQST_SYNCS],
2580                 .maxlen         = sizeof(int),
2581                 .mode           = 0444,
2582                 .proc_handler   = do_proc_dqstats,
2583         },
2584 #ifdef CONFIG_PRINT_QUOTA_WARNING
2585         {
2586                 .procname       = "warnings",
2587                 .data           = &flag_print_warnings,
2588                 .maxlen         = sizeof(int),
2589                 .mode           = 0644,
2590                 .proc_handler   = proc_dointvec,
2591         },
2592 #endif
2593         { },
2594 };
2595
2596 static ctl_table fs_table[] = {
2597         {
2598                 .procname       = "quota",
2599                 .mode           = 0555,
2600                 .child          = fs_dqstats_table,
2601         },
2602         { },
2603 };
2604
2605 static ctl_table sys_table[] = {
2606         {
2607                 .procname       = "fs",
2608                 .mode           = 0555,
2609                 .child          = fs_table,
2610         },
2611         { },
2612 };
2613
2614 static int __init dquot_init(void)
2615 {
2616         int i, ret;
2617         unsigned long nr_hash, order;
2618
2619         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2620
2621         register_sysctl_table(sys_table);
2622
2623         dquot_cachep = kmem_cache_create("dquot",
2624                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2625                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2626                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2627                         NULL);
2628
2629         order = 0;
2630         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2631         if (!dquot_hash)
2632                 panic("Cannot create dquot hash table");
2633
2634         for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
2635                 ret = percpu_counter_init(&dqstats.counter[i], 0);
2636                 if (ret)
2637                         panic("Cannot create dquot stat counters");
2638         }
2639
2640         /* Find power-of-two hlist_heads which can fit into allocation */
2641         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2642         dq_hash_bits = 0;
2643         do {
2644                 dq_hash_bits++;
2645         } while (nr_hash >> dq_hash_bits);
2646         dq_hash_bits--;
2647
2648         nr_hash = 1UL << dq_hash_bits;
2649         dq_hash_mask = nr_hash - 1;
2650         for (i = 0; i < nr_hash; i++)
2651                 INIT_HLIST_HEAD(dquot_hash + i);
2652
2653         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2654                         nr_hash, order, (PAGE_SIZE << order));
2655
2656         register_shrinker(&dqcache_shrinker);
2657
2658         return 0;
2659 }
2660 module_init(dquot_init);