Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
[linux-drm-fsl-dcu.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/sched.h>
75 #include <linux/kmod.h>
76 #include <linux/namei.h>
77 #include <linux/capability.h>
78 #include <linux/quotaops.h>
79 #include "../internal.h" /* ugh */
80
81 #include <linux/uaccess.h>
82
83 /*
84  * There are three quota SMP locks. dq_list_lock protects all lists with quotas
85  * and quota formats.
86  * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
87  * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
88  * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
89  * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
90  * modifications of quota state (on quotaon and quotaoff) and readers who care
91  * about latest values take it as well.
92  *
93  * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
94  *   dq_list_lock > dq_state_lock
95  *
96  * Note that some things (eg. sb pointer, type, id) doesn't change during
97  * the life of the dquot structure and so needn't to be protected by a lock
98  *
99  * Any operation working on dquots via inode pointers must hold dqptr_sem.  If
100  * operation is just reading pointers from inode (or not using them at all) the
101  * read lock is enough. If pointers are altered function must hold write lock.
102  * Special care needs to be taken about S_NOQUOTA inode flag (marking that
103  * inode is a quota file). Functions adding pointers from inode to dquots have
104  * to check this flag under dqptr_sem and then (if S_NOQUOTA is not set) they
105  * have to do all pointer modifications before dropping dqptr_sem. This makes
106  * sure they cannot race with quotaon which first sets S_NOQUOTA flag and
107  * then drops all pointers to dquots from an inode.
108  *
109  * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
110  * from inodes (dquot_alloc_space() and such don't check the dq_lock).
111  * Currently dquot is locked only when it is being read to memory (or space for
112  * it is being allocated) on the first dqget() and when it is being released on
113  * the last dqput(). The allocation and release oparations are serialized by
114  * the dq_lock and by checking the use count in dquot_release().  Write
115  * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
116  * spinlock to internal buffers before writing.
117  *
118  * Lock ordering (including related VFS locks) is the following:
119  *   dqonoff_mutex > i_mutex > journal_lock > dqptr_sem > dquot->dq_lock >
120  *   dqio_mutex
121  * dqonoff_mutex > i_mutex comes from dquot_quota_sync, dquot_enable, etc.
122  * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem >
123  * dqptr_sem. But filesystem has to count with the fact that functions such as
124  * dquot_alloc_space() acquire dqptr_sem and they usually have to be called
125  * from inside a transaction to keep filesystem consistency after a crash. Also
126  * filesystems usually want to do some IO on dquot from ->mark_dirty which is
127  * called with dqptr_sem held.
128  */
129
130 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
131 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
132 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
133 EXPORT_SYMBOL(dq_data_lock);
134
135 void __quota_error(struct super_block *sb, const char *func,
136                    const char *fmt, ...)
137 {
138         if (printk_ratelimit()) {
139                 va_list args;
140                 struct va_format vaf;
141
142                 va_start(args, fmt);
143
144                 vaf.fmt = fmt;
145                 vaf.va = &args;
146
147                 printk(KERN_ERR "Quota error (device %s): %s: %pV\n",
148                        sb->s_id, func, &vaf);
149
150                 va_end(args);
151         }
152 }
153 EXPORT_SYMBOL(__quota_error);
154
155 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING)
156 static char *quotatypes[] = INITQFNAMES;
157 #endif
158 static struct quota_format_type *quota_formats; /* List of registered formats */
159 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
160
161 /* SLAB cache for dquot structures */
162 static struct kmem_cache *dquot_cachep;
163
164 int register_quota_format(struct quota_format_type *fmt)
165 {
166         spin_lock(&dq_list_lock);
167         fmt->qf_next = quota_formats;
168         quota_formats = fmt;
169         spin_unlock(&dq_list_lock);
170         return 0;
171 }
172 EXPORT_SYMBOL(register_quota_format);
173
174 void unregister_quota_format(struct quota_format_type *fmt)
175 {
176         struct quota_format_type **actqf;
177
178         spin_lock(&dq_list_lock);
179         for (actqf = &quota_formats; *actqf && *actqf != fmt;
180              actqf = &(*actqf)->qf_next)
181                 ;
182         if (*actqf)
183                 *actqf = (*actqf)->qf_next;
184         spin_unlock(&dq_list_lock);
185 }
186 EXPORT_SYMBOL(unregister_quota_format);
187
188 static struct quota_format_type *find_quota_format(int id)
189 {
190         struct quota_format_type *actqf;
191
192         spin_lock(&dq_list_lock);
193         for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
194              actqf = actqf->qf_next)
195                 ;
196         if (!actqf || !try_module_get(actqf->qf_owner)) {
197                 int qm;
198
199                 spin_unlock(&dq_list_lock);
200                 
201                 for (qm = 0; module_names[qm].qm_fmt_id &&
202                              module_names[qm].qm_fmt_id != id; qm++)
203                         ;
204                 if (!module_names[qm].qm_fmt_id ||
205                     request_module(module_names[qm].qm_mod_name))
206                         return NULL;
207
208                 spin_lock(&dq_list_lock);
209                 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
210                      actqf = actqf->qf_next)
211                         ;
212                 if (actqf && !try_module_get(actqf->qf_owner))
213                         actqf = NULL;
214         }
215         spin_unlock(&dq_list_lock);
216         return actqf;
217 }
218
219 static void put_quota_format(struct quota_format_type *fmt)
220 {
221         module_put(fmt->qf_owner);
222 }
223
224 /*
225  * Dquot List Management:
226  * The quota code uses three lists for dquot management: the inuse_list,
227  * free_dquots, and dquot_hash[] array. A single dquot structure may be
228  * on all three lists, depending on its current state.
229  *
230  * All dquots are placed to the end of inuse_list when first created, and this
231  * list is used for invalidate operation, which must look at every dquot.
232  *
233  * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
234  * and this list is searched whenever we need an available dquot.  Dquots are
235  * removed from the list as soon as they are used again, and
236  * dqstats.free_dquots gives the number of dquots on the list. When
237  * dquot is invalidated it's completely released from memory.
238  *
239  * Dquots with a specific identity (device, type and id) are placed on
240  * one of the dquot_hash[] hash chains. The provides an efficient search
241  * mechanism to locate a specific dquot.
242  */
243
244 static LIST_HEAD(inuse_list);
245 static LIST_HEAD(free_dquots);
246 static unsigned int dq_hash_bits, dq_hash_mask;
247 static struct hlist_head *dquot_hash;
248
249 struct dqstats dqstats;
250 EXPORT_SYMBOL(dqstats);
251
252 static qsize_t inode_get_rsv_space(struct inode *inode);
253 static void __dquot_initialize(struct inode *inode, int type);
254
255 static inline unsigned int
256 hashfn(const struct super_block *sb, unsigned int id, int type)
257 {
258         unsigned long tmp;
259
260         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
261         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
262 }
263
264 /*
265  * Following list functions expect dq_list_lock to be held
266  */
267 static inline void insert_dquot_hash(struct dquot *dquot)
268 {
269         struct hlist_head *head;
270         head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
271         hlist_add_head(&dquot->dq_hash, head);
272 }
273
274 static inline void remove_dquot_hash(struct dquot *dquot)
275 {
276         hlist_del_init(&dquot->dq_hash);
277 }
278
279 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
280                                 unsigned int id, int type)
281 {
282         struct hlist_node *node;
283         struct dquot *dquot;
284
285         hlist_for_each (node, dquot_hash+hashent) {
286                 dquot = hlist_entry(node, struct dquot, dq_hash);
287                 if (dquot->dq_sb == sb && dquot->dq_id == id &&
288                     dquot->dq_type == type)
289                         return dquot;
290         }
291         return NULL;
292 }
293
294 /* Add a dquot to the tail of the free list */
295 static inline void put_dquot_last(struct dquot *dquot)
296 {
297         list_add_tail(&dquot->dq_free, &free_dquots);
298         dqstats_inc(DQST_FREE_DQUOTS);
299 }
300
301 static inline void remove_free_dquot(struct dquot *dquot)
302 {
303         if (list_empty(&dquot->dq_free))
304                 return;
305         list_del_init(&dquot->dq_free);
306         dqstats_dec(DQST_FREE_DQUOTS);
307 }
308
309 static inline void put_inuse(struct dquot *dquot)
310 {
311         /* We add to the back of inuse list so we don't have to restart
312          * when traversing this list and we block */
313         list_add_tail(&dquot->dq_inuse, &inuse_list);
314         dqstats_inc(DQST_ALLOC_DQUOTS);
315 }
316
317 static inline void remove_inuse(struct dquot *dquot)
318 {
319         dqstats_dec(DQST_ALLOC_DQUOTS);
320         list_del(&dquot->dq_inuse);
321 }
322 /*
323  * End of list functions needing dq_list_lock
324  */
325
326 static void wait_on_dquot(struct dquot *dquot)
327 {
328         mutex_lock(&dquot->dq_lock);
329         mutex_unlock(&dquot->dq_lock);
330 }
331
332 static inline int dquot_dirty(struct dquot *dquot)
333 {
334         return test_bit(DQ_MOD_B, &dquot->dq_flags);
335 }
336
337 static inline int mark_dquot_dirty(struct dquot *dquot)
338 {
339         return dquot->dq_sb->dq_op->mark_dirty(dquot);
340 }
341
342 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */
343 int dquot_mark_dquot_dirty(struct dquot *dquot)
344 {
345         int ret = 1;
346
347         /* If quota is dirty already, we don't have to acquire dq_list_lock */
348         if (test_bit(DQ_MOD_B, &dquot->dq_flags))
349                 return 1;
350
351         spin_lock(&dq_list_lock);
352         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) {
353                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
354                                 info[dquot->dq_type].dqi_dirty_list);
355                 ret = 0;
356         }
357         spin_unlock(&dq_list_lock);
358         return ret;
359 }
360 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
361
362 /* Dirtify all the dquots - this can block when journalling */
363 static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
364 {
365         int ret, err, cnt;
366
367         ret = err = 0;
368         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
369                 if (dquot[cnt])
370                         /* Even in case of error we have to continue */
371                         ret = mark_dquot_dirty(dquot[cnt]);
372                 if (!err)
373                         err = ret;
374         }
375         return err;
376 }
377
378 static inline void dqput_all(struct dquot **dquot)
379 {
380         unsigned int cnt;
381
382         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
383                 dqput(dquot[cnt]);
384 }
385
386 /* This function needs dq_list_lock */
387 static inline int clear_dquot_dirty(struct dquot *dquot)
388 {
389         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
390                 return 0;
391         list_del_init(&dquot->dq_dirty);
392         return 1;
393 }
394
395 void mark_info_dirty(struct super_block *sb, int type)
396 {
397         set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
398 }
399 EXPORT_SYMBOL(mark_info_dirty);
400
401 /*
402  *      Read dquot from disk and alloc space for it
403  */
404
405 int dquot_acquire(struct dquot *dquot)
406 {
407         int ret = 0, ret2 = 0;
408         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
409
410         mutex_lock(&dquot->dq_lock);
411         mutex_lock(&dqopt->dqio_mutex);
412         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
413                 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
414         if (ret < 0)
415                 goto out_iolock;
416         set_bit(DQ_READ_B, &dquot->dq_flags);
417         /* Instantiate dquot if needed */
418         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
419                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
420                 /* Write the info if needed */
421                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
422                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
423                                                 dquot->dq_sb, dquot->dq_type);
424                 }
425                 if (ret < 0)
426                         goto out_iolock;
427                 if (ret2 < 0) {
428                         ret = ret2;
429                         goto out_iolock;
430                 }
431         }
432         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
433 out_iolock:
434         mutex_unlock(&dqopt->dqio_mutex);
435         mutex_unlock(&dquot->dq_lock);
436         return ret;
437 }
438 EXPORT_SYMBOL(dquot_acquire);
439
440 /*
441  *      Write dquot to disk
442  */
443 int dquot_commit(struct dquot *dquot)
444 {
445         int ret = 0;
446         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
447
448         mutex_lock(&dqopt->dqio_mutex);
449         spin_lock(&dq_list_lock);
450         if (!clear_dquot_dirty(dquot)) {
451                 spin_unlock(&dq_list_lock);
452                 goto out_sem;
453         }
454         spin_unlock(&dq_list_lock);
455         /* Inactive dquot can be only if there was error during read/init
456          * => we have better not writing it */
457         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
458                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
459         else
460                 ret = -EIO;
461 out_sem:
462         mutex_unlock(&dqopt->dqio_mutex);
463         return ret;
464 }
465 EXPORT_SYMBOL(dquot_commit);
466
467 /*
468  *      Release dquot
469  */
470 int dquot_release(struct dquot *dquot)
471 {
472         int ret = 0, ret2 = 0;
473         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
474
475         mutex_lock(&dquot->dq_lock);
476         /* Check whether we are not racing with some other dqget() */
477         if (atomic_read(&dquot->dq_count) > 1)
478                 goto out_dqlock;
479         mutex_lock(&dqopt->dqio_mutex);
480         if (dqopt->ops[dquot->dq_type]->release_dqblk) {
481                 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
482                 /* Write the info */
483                 if (info_dirty(&dqopt->info[dquot->dq_type])) {
484                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
485                                                 dquot->dq_sb, dquot->dq_type);
486                 }
487                 if (ret >= 0)
488                         ret = ret2;
489         }
490         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
491         mutex_unlock(&dqopt->dqio_mutex);
492 out_dqlock:
493         mutex_unlock(&dquot->dq_lock);
494         return ret;
495 }
496 EXPORT_SYMBOL(dquot_release);
497
498 void dquot_destroy(struct dquot *dquot)
499 {
500         kmem_cache_free(dquot_cachep, dquot);
501 }
502 EXPORT_SYMBOL(dquot_destroy);
503
504 static inline void do_destroy_dquot(struct dquot *dquot)
505 {
506         dquot->dq_sb->dq_op->destroy_dquot(dquot);
507 }
508
509 /* Invalidate all dquots on the list. Note that this function is called after
510  * quota is disabled and pointers from inodes removed so there cannot be new
511  * quota users. There can still be some users of quotas due to inodes being
512  * just deleted or pruned by prune_icache() (those are not attached to any
513  * list) or parallel quotactl call. We have to wait for such users.
514  */
515 static void invalidate_dquots(struct super_block *sb, int type)
516 {
517         struct dquot *dquot, *tmp;
518
519 restart:
520         spin_lock(&dq_list_lock);
521         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
522                 if (dquot->dq_sb != sb)
523                         continue;
524                 if (dquot->dq_type != type)
525                         continue;
526                 /* Wait for dquot users */
527                 if (atomic_read(&dquot->dq_count)) {
528                         DEFINE_WAIT(wait);
529
530                         atomic_inc(&dquot->dq_count);
531                         prepare_to_wait(&dquot->dq_wait_unused, &wait,
532                                         TASK_UNINTERRUPTIBLE);
533                         spin_unlock(&dq_list_lock);
534                         /* Once dqput() wakes us up, we know it's time to free
535                          * the dquot.
536                          * IMPORTANT: we rely on the fact that there is always
537                          * at most one process waiting for dquot to free.
538                          * Otherwise dq_count would be > 1 and we would never
539                          * wake up.
540                          */
541                         if (atomic_read(&dquot->dq_count) > 1)
542                                 schedule();
543                         finish_wait(&dquot->dq_wait_unused, &wait);
544                         dqput(dquot);
545                         /* At this moment dquot() need not exist (it could be
546                          * reclaimed by prune_dqcache(). Hence we must
547                          * restart. */
548                         goto restart;
549                 }
550                 /*
551                  * Quota now has no users and it has been written on last
552                  * dqput()
553                  */
554                 remove_dquot_hash(dquot);
555                 remove_free_dquot(dquot);
556                 remove_inuse(dquot);
557                 do_destroy_dquot(dquot);
558         }
559         spin_unlock(&dq_list_lock);
560 }
561
562 /* Call callback for every active dquot on given filesystem */
563 int dquot_scan_active(struct super_block *sb,
564                       int (*fn)(struct dquot *dquot, unsigned long priv),
565                       unsigned long priv)
566 {
567         struct dquot *dquot, *old_dquot = NULL;
568         int ret = 0;
569
570         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
571         spin_lock(&dq_list_lock);
572         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
573                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
574                         continue;
575                 if (dquot->dq_sb != sb)
576                         continue;
577                 /* Now we have active dquot so we can just increase use count */
578                 atomic_inc(&dquot->dq_count);
579                 spin_unlock(&dq_list_lock);
580                 dqstats_inc(DQST_LOOKUPS);
581                 dqput(old_dquot);
582                 old_dquot = dquot;
583                 ret = fn(dquot, priv);
584                 if (ret < 0)
585                         goto out;
586                 spin_lock(&dq_list_lock);
587                 /* We are safe to continue now because our dquot could not
588                  * be moved out of the inuse list while we hold the reference */
589         }
590         spin_unlock(&dq_list_lock);
591 out:
592         dqput(old_dquot);
593         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
594         return ret;
595 }
596 EXPORT_SYMBOL(dquot_scan_active);
597
598 /* Write all dquot structures to quota files */
599 int dquot_writeback_dquots(struct super_block *sb, int type)
600 {
601         struct list_head *dirty;
602         struct dquot *dquot;
603         struct quota_info *dqopt = sb_dqopt(sb);
604         int cnt;
605         int err, ret = 0;
606
607         mutex_lock(&dqopt->dqonoff_mutex);
608         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
609                 if (type != -1 && cnt != type)
610                         continue;
611                 if (!sb_has_quota_active(sb, cnt))
612                         continue;
613                 spin_lock(&dq_list_lock);
614                 dirty = &dqopt->info[cnt].dqi_dirty_list;
615                 while (!list_empty(dirty)) {
616                         dquot = list_first_entry(dirty, struct dquot,
617                                                  dq_dirty);
618                         /* Dirty and inactive can be only bad dquot... */
619                         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
620                                 clear_dquot_dirty(dquot);
621                                 continue;
622                         }
623                         /* Now we have active dquot from which someone is
624                          * holding reference so we can safely just increase
625                          * use count */
626                         atomic_inc(&dquot->dq_count);
627                         spin_unlock(&dq_list_lock);
628                         dqstats_inc(DQST_LOOKUPS);
629                         err = sb->dq_op->write_dquot(dquot);
630                         if (!ret && err)
631                                 err = ret;
632                         dqput(dquot);
633                         spin_lock(&dq_list_lock);
634                 }
635                 spin_unlock(&dq_list_lock);
636         }
637
638         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
639                 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
640                     && info_dirty(&dqopt->info[cnt]))
641                         sb->dq_op->write_info(sb, cnt);
642         dqstats_inc(DQST_SYNCS);
643         mutex_unlock(&dqopt->dqonoff_mutex);
644
645         return ret;
646 }
647 EXPORT_SYMBOL(dquot_writeback_dquots);
648
649 /* Write all dquot structures to disk and make them visible from userspace */
650 int dquot_quota_sync(struct super_block *sb, int type)
651 {
652         struct quota_info *dqopt = sb_dqopt(sb);
653         int cnt;
654         int ret;
655
656         ret = dquot_writeback_dquots(sb, type);
657         if (ret)
658                 return ret;
659         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
660                 return 0;
661
662         /* This is not very clever (and fast) but currently I don't know about
663          * any other simple way of getting quota data to disk and we must get
664          * them there for userspace to be visible... */
665         if (sb->s_op->sync_fs)
666                 sb->s_op->sync_fs(sb, 1);
667         sync_blockdev(sb->s_bdev);
668
669         /*
670          * Now when everything is written we can discard the pagecache so
671          * that userspace sees the changes.
672          */
673         mutex_lock(&dqopt->dqonoff_mutex);
674         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
675                 if (type != -1 && cnt != type)
676                         continue;
677                 if (!sb_has_quota_active(sb, cnt))
678                         continue;
679                 mutex_lock(&dqopt->files[cnt]->i_mutex);
680                 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
681                 mutex_unlock(&dqopt->files[cnt]->i_mutex);
682         }
683         mutex_unlock(&dqopt->dqonoff_mutex);
684
685         return 0;
686 }
687 EXPORT_SYMBOL(dquot_quota_sync);
688
689 /* Free unused dquots from cache */
690 static void prune_dqcache(int count)
691 {
692         struct list_head *head;
693         struct dquot *dquot;
694
695         head = free_dquots.prev;
696         while (head != &free_dquots && count) {
697                 dquot = list_entry(head, struct dquot, dq_free);
698                 remove_dquot_hash(dquot);
699                 remove_free_dquot(dquot);
700                 remove_inuse(dquot);
701                 do_destroy_dquot(dquot);
702                 count--;
703                 head = free_dquots.prev;
704         }
705 }
706
707 /*
708  * This is called from kswapd when we think we need some
709  * more memory
710  */
711 static int shrink_dqcache_memory(struct shrinker *shrink,
712                                  struct shrink_control *sc)
713 {
714         int nr = sc->nr_to_scan;
715
716         if (nr) {
717                 spin_lock(&dq_list_lock);
718                 prune_dqcache(nr);
719                 spin_unlock(&dq_list_lock);
720         }
721         return ((unsigned)
722                 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])
723                 /100) * sysctl_vfs_cache_pressure;
724 }
725
726 static struct shrinker dqcache_shrinker = {
727         .shrink = shrink_dqcache_memory,
728         .seeks = DEFAULT_SEEKS,
729 };
730
731 /*
732  * Put reference to dquot
733  * NOTE: If you change this function please check whether dqput_blocks() works right...
734  */
735 void dqput(struct dquot *dquot)
736 {
737         int ret;
738
739         if (!dquot)
740                 return;
741 #ifdef CONFIG_QUOTA_DEBUG
742         if (!atomic_read(&dquot->dq_count)) {
743                 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d",
744                             quotatypes[dquot->dq_type], dquot->dq_id);
745                 BUG();
746         }
747 #endif
748         dqstats_inc(DQST_DROPS);
749 we_slept:
750         spin_lock(&dq_list_lock);
751         if (atomic_read(&dquot->dq_count) > 1) {
752                 /* We have more than one user... nothing to do */
753                 atomic_dec(&dquot->dq_count);
754                 /* Releasing dquot during quotaoff phase? */
755                 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
756                     atomic_read(&dquot->dq_count) == 1)
757                         wake_up(&dquot->dq_wait_unused);
758                 spin_unlock(&dq_list_lock);
759                 return;
760         }
761         /* Need to release dquot? */
762         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
763                 spin_unlock(&dq_list_lock);
764                 /* Commit dquot before releasing */
765                 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
766                 if (ret < 0) {
767                         quota_error(dquot->dq_sb, "Can't write quota structure"
768                                     " (error %d). Quota may get out of sync!",
769                                     ret);
770                         /*
771                          * We clear dirty bit anyway, so that we avoid
772                          * infinite loop here
773                          */
774                         spin_lock(&dq_list_lock);
775                         clear_dquot_dirty(dquot);
776                         spin_unlock(&dq_list_lock);
777                 }
778                 goto we_slept;
779         }
780         /* Clear flag in case dquot was inactive (something bad happened) */
781         clear_dquot_dirty(dquot);
782         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
783                 spin_unlock(&dq_list_lock);
784                 dquot->dq_sb->dq_op->release_dquot(dquot);
785                 goto we_slept;
786         }
787         atomic_dec(&dquot->dq_count);
788 #ifdef CONFIG_QUOTA_DEBUG
789         /* sanity check */
790         BUG_ON(!list_empty(&dquot->dq_free));
791 #endif
792         put_dquot_last(dquot);
793         spin_unlock(&dq_list_lock);
794 }
795 EXPORT_SYMBOL(dqput);
796
797 struct dquot *dquot_alloc(struct super_block *sb, int type)
798 {
799         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
800 }
801 EXPORT_SYMBOL(dquot_alloc);
802
803 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
804 {
805         struct dquot *dquot;
806
807         dquot = sb->dq_op->alloc_dquot(sb, type);
808         if(!dquot)
809                 return NULL;
810
811         mutex_init(&dquot->dq_lock);
812         INIT_LIST_HEAD(&dquot->dq_free);
813         INIT_LIST_HEAD(&dquot->dq_inuse);
814         INIT_HLIST_NODE(&dquot->dq_hash);
815         INIT_LIST_HEAD(&dquot->dq_dirty);
816         init_waitqueue_head(&dquot->dq_wait_unused);
817         dquot->dq_sb = sb;
818         dquot->dq_type = type;
819         atomic_set(&dquot->dq_count, 1);
820
821         return dquot;
822 }
823
824 /*
825  * Get reference to dquot
826  *
827  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
828  * destroying our dquot by:
829  *   a) checking for quota flags under dq_list_lock and
830  *   b) getting a reference to dquot before we release dq_list_lock
831  */
832 struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
833 {
834         unsigned int hashent = hashfn(sb, id, type);
835         struct dquot *dquot = NULL, *empty = NULL;
836
837         if (!sb_has_quota_active(sb, type))
838                 return NULL;
839 we_slept:
840         spin_lock(&dq_list_lock);
841         spin_lock(&dq_state_lock);
842         if (!sb_has_quota_active(sb, type)) {
843                 spin_unlock(&dq_state_lock);
844                 spin_unlock(&dq_list_lock);
845                 goto out;
846         }
847         spin_unlock(&dq_state_lock);
848
849         dquot = find_dquot(hashent, sb, id, type);
850         if (!dquot) {
851                 if (!empty) {
852                         spin_unlock(&dq_list_lock);
853                         empty = get_empty_dquot(sb, type);
854                         if (!empty)
855                                 schedule();     /* Try to wait for a moment... */
856                         goto we_slept;
857                 }
858                 dquot = empty;
859                 empty = NULL;
860                 dquot->dq_id = id;
861                 /* all dquots go on the inuse_list */
862                 put_inuse(dquot);
863                 /* hash it first so it can be found */
864                 insert_dquot_hash(dquot);
865                 spin_unlock(&dq_list_lock);
866                 dqstats_inc(DQST_LOOKUPS);
867         } else {
868                 if (!atomic_read(&dquot->dq_count))
869                         remove_free_dquot(dquot);
870                 atomic_inc(&dquot->dq_count);
871                 spin_unlock(&dq_list_lock);
872                 dqstats_inc(DQST_CACHE_HITS);
873                 dqstats_inc(DQST_LOOKUPS);
874         }
875         /* Wait for dq_lock - after this we know that either dquot_release() is
876          * already finished or it will be canceled due to dq_count > 1 test */
877         wait_on_dquot(dquot);
878         /* Read the dquot / allocate space in quota file */
879         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) &&
880             sb->dq_op->acquire_dquot(dquot) < 0) {
881                 dqput(dquot);
882                 dquot = NULL;
883                 goto out;
884         }
885 #ifdef CONFIG_QUOTA_DEBUG
886         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
887 #endif
888 out:
889         if (empty)
890                 do_destroy_dquot(empty);
891
892         return dquot;
893 }
894 EXPORT_SYMBOL(dqget);
895
896 static int dqinit_needed(struct inode *inode, int type)
897 {
898         int cnt;
899
900         if (IS_NOQUOTA(inode))
901                 return 0;
902         if (type != -1)
903                 return !inode->i_dquot[type];
904         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
905                 if (!inode->i_dquot[cnt])
906                         return 1;
907         return 0;
908 }
909
910 /* This routine is guarded by dqonoff_mutex mutex */
911 static void add_dquot_ref(struct super_block *sb, int type)
912 {
913         struct inode *inode, *old_inode = NULL;
914 #ifdef CONFIG_QUOTA_DEBUG
915         int reserved = 0;
916 #endif
917
918         spin_lock(&inode_sb_list_lock);
919         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
920                 spin_lock(&inode->i_lock);
921                 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
922                     !atomic_read(&inode->i_writecount) ||
923                     !dqinit_needed(inode, type)) {
924                         spin_unlock(&inode->i_lock);
925                         continue;
926                 }
927                 __iget(inode);
928                 spin_unlock(&inode->i_lock);
929                 spin_unlock(&inode_sb_list_lock);
930
931 #ifdef CONFIG_QUOTA_DEBUG
932                 if (unlikely(inode_get_rsv_space(inode) > 0))
933                         reserved = 1;
934 #endif
935                 iput(old_inode);
936                 __dquot_initialize(inode, type);
937
938                 /*
939                  * We hold a reference to 'inode' so it couldn't have been
940                  * removed from s_inodes list while we dropped the
941                  * inode_sb_list_lock We cannot iput the inode now as we can be
942                  * holding the last reference and we cannot iput it under
943                  * inode_sb_list_lock. So we keep the reference and iput it
944                  * later.
945                  */
946                 old_inode = inode;
947                 spin_lock(&inode_sb_list_lock);
948         }
949         spin_unlock(&inode_sb_list_lock);
950         iput(old_inode);
951
952 #ifdef CONFIG_QUOTA_DEBUG
953         if (reserved) {
954                 quota_error(sb, "Writes happened before quota was turned on "
955                         "thus quota information is probably inconsistent. "
956                         "Please run quotacheck(8)");
957         }
958 #endif
959 }
960
961 /*
962  * Return 0 if dqput() won't block.
963  * (note that 1 doesn't necessarily mean blocking)
964  */
965 static inline int dqput_blocks(struct dquot *dquot)
966 {
967         if (atomic_read(&dquot->dq_count) <= 1)
968                 return 1;
969         return 0;
970 }
971
972 /*
973  * Remove references to dquots from inode and add dquot to list for freeing
974  * if we have the last reference to dquot
975  * We can't race with anybody because we hold dqptr_sem for writing...
976  */
977 static int remove_inode_dquot_ref(struct inode *inode, int type,
978                                   struct list_head *tofree_head)
979 {
980         struct dquot *dquot = inode->i_dquot[type];
981
982         inode->i_dquot[type] = NULL;
983         if (dquot) {
984                 if (dqput_blocks(dquot)) {
985 #ifdef CONFIG_QUOTA_DEBUG
986                         if (atomic_read(&dquot->dq_count) != 1)
987                                 quota_error(inode->i_sb, "Adding dquot with "
988                                             "dq_count %d to dispose list",
989                                             atomic_read(&dquot->dq_count));
990 #endif
991                         spin_lock(&dq_list_lock);
992                         /* As dquot must have currently users it can't be on
993                          * the free list... */
994                         list_add(&dquot->dq_free, tofree_head);
995                         spin_unlock(&dq_list_lock);
996                         return 1;
997                 }
998                 else
999                         dqput(dquot);   /* We have guaranteed we won't block */
1000         }
1001         return 0;
1002 }
1003
1004 /*
1005  * Free list of dquots
1006  * Dquots are removed from inodes and no new references can be got so we are
1007  * the only ones holding reference
1008  */
1009 static void put_dquot_list(struct list_head *tofree_head)
1010 {
1011         struct list_head *act_head;
1012         struct dquot *dquot;
1013
1014         act_head = tofree_head->next;
1015         while (act_head != tofree_head) {
1016                 dquot = list_entry(act_head, struct dquot, dq_free);
1017                 act_head = act_head->next;
1018                 /* Remove dquot from the list so we won't have problems... */
1019                 list_del_init(&dquot->dq_free);
1020                 dqput(dquot);
1021         }
1022 }
1023
1024 static void remove_dquot_ref(struct super_block *sb, int type,
1025                 struct list_head *tofree_head)
1026 {
1027         struct inode *inode;
1028         int reserved = 0;
1029
1030         spin_lock(&inode_sb_list_lock);
1031         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
1032                 /*
1033                  *  We have to scan also I_NEW inodes because they can already
1034                  *  have quota pointer initialized. Luckily, we need to touch
1035                  *  only quota pointers and these have separate locking
1036                  *  (dqptr_sem).
1037                  */
1038                 if (!IS_NOQUOTA(inode)) {
1039                         if (unlikely(inode_get_rsv_space(inode) > 0))
1040                                 reserved = 1;
1041                         remove_inode_dquot_ref(inode, type, tofree_head);
1042                 }
1043         }
1044         spin_unlock(&inode_sb_list_lock);
1045 #ifdef CONFIG_QUOTA_DEBUG
1046         if (reserved) {
1047                 printk(KERN_WARNING "VFS (%s): Writes happened after quota"
1048                         " was disabled thus quota information is probably "
1049                         "inconsistent. Please run quotacheck(8).\n", sb->s_id);
1050         }
1051 #endif
1052 }
1053
1054 /* Gather all references from inodes and drop them */
1055 static void drop_dquot_ref(struct super_block *sb, int type)
1056 {
1057         LIST_HEAD(tofree_head);
1058
1059         if (sb->dq_op) {
1060                 down_write(&sb_dqopt(sb)->dqptr_sem);
1061                 remove_dquot_ref(sb, type, &tofree_head);
1062                 up_write(&sb_dqopt(sb)->dqptr_sem);
1063                 put_dquot_list(&tofree_head);
1064         }
1065 }
1066
1067 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
1068 {
1069         dquot->dq_dqb.dqb_curinodes += number;
1070 }
1071
1072 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
1073 {
1074         dquot->dq_dqb.dqb_curspace += number;
1075 }
1076
1077 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
1078 {
1079         dquot->dq_dqb.dqb_rsvspace += number;
1080 }
1081
1082 /*
1083  * Claim reserved quota space
1084  */
1085 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number)
1086 {
1087         if (dquot->dq_dqb.dqb_rsvspace < number) {
1088                 WARN_ON_ONCE(1);
1089                 number = dquot->dq_dqb.dqb_rsvspace;
1090         }
1091         dquot->dq_dqb.dqb_curspace += number;
1092         dquot->dq_dqb.dqb_rsvspace -= number;
1093 }
1094
1095 static inline
1096 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
1097 {
1098         if (dquot->dq_dqb.dqb_rsvspace >= number)
1099                 dquot->dq_dqb.dqb_rsvspace -= number;
1100         else {
1101                 WARN_ON_ONCE(1);
1102                 dquot->dq_dqb.dqb_rsvspace = 0;
1103         }
1104 }
1105
1106 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1107 {
1108         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1109             dquot->dq_dqb.dqb_curinodes >= number)
1110                 dquot->dq_dqb.dqb_curinodes -= number;
1111         else
1112                 dquot->dq_dqb.dqb_curinodes = 0;
1113         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1114                 dquot->dq_dqb.dqb_itime = (time_t) 0;
1115         clear_bit(DQ_INODES_B, &dquot->dq_flags);
1116 }
1117
1118 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1119 {
1120         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1121             dquot->dq_dqb.dqb_curspace >= number)
1122                 dquot->dq_dqb.dqb_curspace -= number;
1123         else
1124                 dquot->dq_dqb.dqb_curspace = 0;
1125         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1126                 dquot->dq_dqb.dqb_btime = (time_t) 0;
1127         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1128 }
1129
1130 struct dquot_warn {
1131         struct super_block *w_sb;
1132         qid_t w_dq_id;
1133         short w_dq_type;
1134         short w_type;
1135 };
1136
1137 static int warning_issued(struct dquot *dquot, const int warntype)
1138 {
1139         int flag = (warntype == QUOTA_NL_BHARDWARN ||
1140                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1141                 ((warntype == QUOTA_NL_IHARDWARN ||
1142                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1143
1144         if (!flag)
1145                 return 0;
1146         return test_and_set_bit(flag, &dquot->dq_flags);
1147 }
1148
1149 #ifdef CONFIG_PRINT_QUOTA_WARNING
1150 static int flag_print_warnings = 1;
1151
1152 static int need_print_warning(struct dquot_warn *warn)
1153 {
1154         if (!flag_print_warnings)
1155                 return 0;
1156
1157         switch (warn->w_dq_type) {
1158                 case USRQUOTA:
1159                         return current_fsuid() == warn->w_dq_id;
1160                 case GRPQUOTA:
1161                         return in_group_p(warn->w_dq_id);
1162         }
1163         return 0;
1164 }
1165
1166 /* Print warning to user which exceeded quota */
1167 static void print_warning(struct dquot_warn *warn)
1168 {
1169         char *msg = NULL;
1170         struct tty_struct *tty;
1171         int warntype = warn->w_type;
1172
1173         if (warntype == QUOTA_NL_IHARDBELOW ||
1174             warntype == QUOTA_NL_ISOFTBELOW ||
1175             warntype == QUOTA_NL_BHARDBELOW ||
1176             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn))
1177                 return;
1178
1179         tty = get_current_tty();
1180         if (!tty)
1181                 return;
1182         tty_write_message(tty, warn->w_sb->s_id);
1183         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1184                 tty_write_message(tty, ": warning, ");
1185         else
1186                 tty_write_message(tty, ": write failed, ");
1187         tty_write_message(tty, quotatypes[warn->w_dq_type]);
1188         switch (warntype) {
1189                 case QUOTA_NL_IHARDWARN:
1190                         msg = " file limit reached.\r\n";
1191                         break;
1192                 case QUOTA_NL_ISOFTLONGWARN:
1193                         msg = " file quota exceeded too long.\r\n";
1194                         break;
1195                 case QUOTA_NL_ISOFTWARN:
1196                         msg = " file quota exceeded.\r\n";
1197                         break;
1198                 case QUOTA_NL_BHARDWARN:
1199                         msg = " block limit reached.\r\n";
1200                         break;
1201                 case QUOTA_NL_BSOFTLONGWARN:
1202                         msg = " block quota exceeded too long.\r\n";
1203                         break;
1204                 case QUOTA_NL_BSOFTWARN:
1205                         msg = " block quota exceeded.\r\n";
1206                         break;
1207         }
1208         tty_write_message(tty, msg);
1209         tty_kref_put(tty);
1210 }
1211 #endif
1212
1213 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot,
1214                             int warntype)
1215 {
1216         if (warning_issued(dquot, warntype))
1217                 return;
1218         warn->w_type = warntype;
1219         warn->w_sb = dquot->dq_sb;
1220         warn->w_dq_id = dquot->dq_id;
1221         warn->w_dq_type = dquot->dq_type;
1222 }
1223
1224 /*
1225  * Write warnings to the console and send warning messages over netlink.
1226  *
1227  * Note that this function can call into tty and networking code.
1228  */
1229 static void flush_warnings(struct dquot_warn *warn)
1230 {
1231         int i;
1232
1233         for (i = 0; i < MAXQUOTAS; i++) {
1234                 if (warn[i].w_type == QUOTA_NL_NOWARN)
1235                         continue;
1236 #ifdef CONFIG_PRINT_QUOTA_WARNING
1237                 print_warning(&warn[i]);
1238 #endif
1239                 quota_send_warning(warn[i].w_dq_type, warn[i].w_dq_id,
1240                                    warn[i].w_sb->s_dev, warn[i].w_type);
1241         }
1242 }
1243
1244 static int ignore_hardlimit(struct dquot *dquot)
1245 {
1246         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1247
1248         return capable(CAP_SYS_RESOURCE) &&
1249                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1250                 !(info->dqi_flags & V1_DQF_RSQUASH));
1251 }
1252
1253 /* needs dq_data_lock */
1254 static int check_idq(struct dquot *dquot, qsize_t inodes,
1255                      struct dquot_warn *warn)
1256 {
1257         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1258
1259         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1260             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1261                 return 0;
1262
1263         if (dquot->dq_dqb.dqb_ihardlimit &&
1264             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1265             !ignore_hardlimit(dquot)) {
1266                 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN);
1267                 return -EDQUOT;
1268         }
1269
1270         if (dquot->dq_dqb.dqb_isoftlimit &&
1271             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1272             dquot->dq_dqb.dqb_itime &&
1273             get_seconds() >= dquot->dq_dqb.dqb_itime &&
1274             !ignore_hardlimit(dquot)) {
1275                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN);
1276                 return -EDQUOT;
1277         }
1278
1279         if (dquot->dq_dqb.dqb_isoftlimit &&
1280             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1281             dquot->dq_dqb.dqb_itime == 0) {
1282                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN);
1283                 dquot->dq_dqb.dqb_itime = get_seconds() +
1284                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1285         }
1286
1287         return 0;
1288 }
1289
1290 /* needs dq_data_lock */
1291 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc,
1292                      struct dquot_warn *warn)
1293 {
1294         qsize_t tspace;
1295         struct super_block *sb = dquot->dq_sb;
1296
1297         if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
1298             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1299                 return 0;
1300
1301         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1302                 + space;
1303
1304         if (dquot->dq_dqb.dqb_bhardlimit &&
1305             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1306             !ignore_hardlimit(dquot)) {
1307                 if (!prealloc)
1308                         prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN);
1309                 return -EDQUOT;
1310         }
1311
1312         if (dquot->dq_dqb.dqb_bsoftlimit &&
1313             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1314             dquot->dq_dqb.dqb_btime &&
1315             get_seconds() >= dquot->dq_dqb.dqb_btime &&
1316             !ignore_hardlimit(dquot)) {
1317                 if (!prealloc)
1318                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN);
1319                 return -EDQUOT;
1320         }
1321
1322         if (dquot->dq_dqb.dqb_bsoftlimit &&
1323             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1324             dquot->dq_dqb.dqb_btime == 0) {
1325                 if (!prealloc) {
1326                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN);
1327                         dquot->dq_dqb.dqb_btime = get_seconds() +
1328                             sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
1329                 }
1330                 else
1331                         /*
1332                          * We don't allow preallocation to exceed softlimit so exceeding will
1333                          * be always printed
1334                          */
1335                         return -EDQUOT;
1336         }
1337
1338         return 0;
1339 }
1340
1341 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1342 {
1343         qsize_t newinodes;
1344
1345         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1346             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1347             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
1348                 return QUOTA_NL_NOWARN;
1349
1350         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1351         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1352                 return QUOTA_NL_ISOFTBELOW;
1353         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1354             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1355                 return QUOTA_NL_IHARDBELOW;
1356         return QUOTA_NL_NOWARN;
1357 }
1358
1359 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1360 {
1361         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1362             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1363                 return QUOTA_NL_NOWARN;
1364
1365         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1366                 return QUOTA_NL_BSOFTBELOW;
1367         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1368             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1369                 return QUOTA_NL_BHARDBELOW;
1370         return QUOTA_NL_NOWARN;
1371 }
1372
1373 static int dquot_active(const struct inode *inode)
1374 {
1375         struct super_block *sb = inode->i_sb;
1376
1377         if (IS_NOQUOTA(inode))
1378                 return 0;
1379         return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
1380 }
1381
1382 /*
1383  * Initialize quota pointers in inode
1384  *
1385  * We do things in a bit complicated way but by that we avoid calling
1386  * dqget() and thus filesystem callbacks under dqptr_sem.
1387  *
1388  * It is better to call this function outside of any transaction as it
1389  * might need a lot of space in journal for dquot structure allocation.
1390  */
1391 static void __dquot_initialize(struct inode *inode, int type)
1392 {
1393         unsigned int id = 0;
1394         int cnt;
1395         struct dquot *got[MAXQUOTAS];
1396         struct super_block *sb = inode->i_sb;
1397         qsize_t rsv;
1398
1399         /* First test before acquiring mutex - solves deadlocks when we
1400          * re-enter the quota code and are already holding the mutex */
1401         if (!dquot_active(inode))
1402                 return;
1403
1404         /* First get references to structures we might need. */
1405         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1406                 got[cnt] = NULL;
1407                 if (type != -1 && cnt != type)
1408                         continue;
1409                 switch (cnt) {
1410                 case USRQUOTA:
1411                         id = inode->i_uid;
1412                         break;
1413                 case GRPQUOTA:
1414                         id = inode->i_gid;
1415                         break;
1416                 }
1417                 got[cnt] = dqget(sb, id, cnt);
1418         }
1419
1420         down_write(&sb_dqopt(sb)->dqptr_sem);
1421         if (IS_NOQUOTA(inode))
1422                 goto out_err;
1423         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1424                 if (type != -1 && cnt != type)
1425                         continue;
1426                 /* Avoid races with quotaoff() */
1427                 if (!sb_has_quota_active(sb, cnt))
1428                         continue;
1429                 /* We could race with quotaon or dqget() could have failed */
1430                 if (!got[cnt])
1431                         continue;
1432                 if (!inode->i_dquot[cnt]) {
1433                         inode->i_dquot[cnt] = got[cnt];
1434                         got[cnt] = NULL;
1435                         /*
1436                          * Make quota reservation system happy if someone
1437                          * did a write before quota was turned on
1438                          */
1439                         rsv = inode_get_rsv_space(inode);
1440                         if (unlikely(rsv))
1441                                 dquot_resv_space(inode->i_dquot[cnt], rsv);
1442                 }
1443         }
1444 out_err:
1445         up_write(&sb_dqopt(sb)->dqptr_sem);
1446         /* Drop unused references */
1447         dqput_all(got);
1448 }
1449
1450 void dquot_initialize(struct inode *inode)
1451 {
1452         __dquot_initialize(inode, -1);
1453 }
1454 EXPORT_SYMBOL(dquot_initialize);
1455
1456 /*
1457  *      Release all quotas referenced by inode
1458  */
1459 static void __dquot_drop(struct inode *inode)
1460 {
1461         int cnt;
1462         struct dquot *put[MAXQUOTAS];
1463
1464         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1465         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1466                 put[cnt] = inode->i_dquot[cnt];
1467                 inode->i_dquot[cnt] = NULL;
1468         }
1469         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1470         dqput_all(put);
1471 }
1472
1473 void dquot_drop(struct inode *inode)
1474 {
1475         int cnt;
1476
1477         if (IS_NOQUOTA(inode))
1478                 return;
1479
1480         /*
1481          * Test before calling to rule out calls from proc and such
1482          * where we are not allowed to block. Note that this is
1483          * actually reliable test even without the lock - the caller
1484          * must assure that nobody can come after the DQUOT_DROP and
1485          * add quota pointers back anyway.
1486          */
1487         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1488                 if (inode->i_dquot[cnt])
1489                         break;
1490         }
1491
1492         if (cnt < MAXQUOTAS)
1493                 __dquot_drop(inode);
1494 }
1495 EXPORT_SYMBOL(dquot_drop);
1496
1497 /*
1498  * inode_reserved_space is managed internally by quota, and protected by
1499  * i_lock similar to i_blocks+i_bytes.
1500  */
1501 static qsize_t *inode_reserved_space(struct inode * inode)
1502 {
1503         /* Filesystem must explicitly define it's own method in order to use
1504          * quota reservation interface */
1505         BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1506         return inode->i_sb->dq_op->get_reserved_space(inode);
1507 }
1508
1509 void inode_add_rsv_space(struct inode *inode, qsize_t number)
1510 {
1511         spin_lock(&inode->i_lock);
1512         *inode_reserved_space(inode) += number;
1513         spin_unlock(&inode->i_lock);
1514 }
1515 EXPORT_SYMBOL(inode_add_rsv_space);
1516
1517 void inode_claim_rsv_space(struct inode *inode, qsize_t number)
1518 {
1519         spin_lock(&inode->i_lock);
1520         *inode_reserved_space(inode) -= number;
1521         __inode_add_bytes(inode, number);
1522         spin_unlock(&inode->i_lock);
1523 }
1524 EXPORT_SYMBOL(inode_claim_rsv_space);
1525
1526 void inode_sub_rsv_space(struct inode *inode, qsize_t number)
1527 {
1528         spin_lock(&inode->i_lock);
1529         *inode_reserved_space(inode) -= number;
1530         spin_unlock(&inode->i_lock);
1531 }
1532 EXPORT_SYMBOL(inode_sub_rsv_space);
1533
1534 static qsize_t inode_get_rsv_space(struct inode *inode)
1535 {
1536         qsize_t ret;
1537
1538         if (!inode->i_sb->dq_op->get_reserved_space)
1539                 return 0;
1540         spin_lock(&inode->i_lock);
1541         ret = *inode_reserved_space(inode);
1542         spin_unlock(&inode->i_lock);
1543         return ret;
1544 }
1545
1546 static void inode_incr_space(struct inode *inode, qsize_t number,
1547                                 int reserve)
1548 {
1549         if (reserve)
1550                 inode_add_rsv_space(inode, number);
1551         else
1552                 inode_add_bytes(inode, number);
1553 }
1554
1555 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve)
1556 {
1557         if (reserve)
1558                 inode_sub_rsv_space(inode, number);
1559         else
1560                 inode_sub_bytes(inode, number);
1561 }
1562
1563 /*
1564  * This functions updates i_blocks+i_bytes fields and quota information
1565  * (together with appropriate checks).
1566  *
1567  * NOTE: We absolutely rely on the fact that caller dirties the inode
1568  * (usually helpers in quotaops.h care about this) and holds a handle for
1569  * the current transaction so that dquot write and inode write go into the
1570  * same transaction.
1571  */
1572
1573 /*
1574  * This operation can block, but only after everything is updated
1575  */
1576 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
1577 {
1578         int cnt, ret = 0;
1579         struct dquot_warn warn[MAXQUOTAS];
1580         struct dquot **dquots = inode->i_dquot;
1581         int reserve = flags & DQUOT_SPACE_RESERVE;
1582
1583         /*
1584          * First test before acquiring mutex - solves deadlocks when we
1585          * re-enter the quota code and are already holding the mutex
1586          */
1587         if (!dquot_active(inode)) {
1588                 inode_incr_space(inode, number, reserve);
1589                 goto out;
1590         }
1591
1592         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1593         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1594                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1595
1596         spin_lock(&dq_data_lock);
1597         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1598                 if (!dquots[cnt])
1599                         continue;
1600                 ret = check_bdq(dquots[cnt], number,
1601                                 !(flags & DQUOT_SPACE_WARN), &warn[cnt]);
1602                 if (ret && !(flags & DQUOT_SPACE_NOFAIL)) {
1603                         spin_unlock(&dq_data_lock);
1604                         goto out_flush_warn;
1605                 }
1606         }
1607         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1608                 if (!dquots[cnt])
1609                         continue;
1610                 if (reserve)
1611                         dquot_resv_space(dquots[cnt], number);
1612                 else
1613                         dquot_incr_space(dquots[cnt], number);
1614         }
1615         inode_incr_space(inode, number, reserve);
1616         spin_unlock(&dq_data_lock);
1617
1618         if (reserve)
1619                 goto out_flush_warn;
1620         mark_all_dquot_dirty(dquots);
1621 out_flush_warn:
1622         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1623         flush_warnings(warn);
1624 out:
1625         return ret;
1626 }
1627 EXPORT_SYMBOL(__dquot_alloc_space);
1628
1629 /*
1630  * This operation can block, but only after everything is updated
1631  */
1632 int dquot_alloc_inode(const struct inode *inode)
1633 {
1634         int cnt, ret = 0;
1635         struct dquot_warn warn[MAXQUOTAS];
1636         struct dquot * const *dquots = inode->i_dquot;
1637
1638         /* First test before acquiring mutex - solves deadlocks when we
1639          * re-enter the quota code and are already holding the mutex */
1640         if (!dquot_active(inode))
1641                 return 0;
1642         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1643                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1644         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1645         spin_lock(&dq_data_lock);
1646         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1647                 if (!dquots[cnt])
1648                         continue;
1649                 ret = check_idq(dquots[cnt], 1, &warn[cnt]);
1650                 if (ret)
1651                         goto warn_put_all;
1652         }
1653
1654         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1655                 if (!dquots[cnt])
1656                         continue;
1657                 dquot_incr_inodes(dquots[cnt], 1);
1658         }
1659
1660 warn_put_all:
1661         spin_unlock(&dq_data_lock);
1662         if (ret == 0)
1663                 mark_all_dquot_dirty(dquots);
1664         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1665         flush_warnings(warn);
1666         return ret;
1667 }
1668 EXPORT_SYMBOL(dquot_alloc_inode);
1669
1670 /*
1671  * Convert in-memory reserved quotas to real consumed quotas
1672  */
1673 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
1674 {
1675         int cnt;
1676
1677         if (!dquot_active(inode)) {
1678                 inode_claim_rsv_space(inode, number);
1679                 return 0;
1680         }
1681
1682         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1683         spin_lock(&dq_data_lock);
1684         /* Claim reserved quotas to allocated quotas */
1685         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1686                 if (inode->i_dquot[cnt])
1687                         dquot_claim_reserved_space(inode->i_dquot[cnt],
1688                                                         number);
1689         }
1690         /* Update inode bytes */
1691         inode_claim_rsv_space(inode, number);
1692         spin_unlock(&dq_data_lock);
1693         mark_all_dquot_dirty(inode->i_dquot);
1694         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1695         return 0;
1696 }
1697 EXPORT_SYMBOL(dquot_claim_space_nodirty);
1698
1699 /*
1700  * This operation can block, but only after everything is updated
1701  */
1702 void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
1703 {
1704         unsigned int cnt;
1705         struct dquot_warn warn[MAXQUOTAS];
1706         struct dquot **dquots = inode->i_dquot;
1707         int reserve = flags & DQUOT_SPACE_RESERVE;
1708
1709         /* First test before acquiring mutex - solves deadlocks when we
1710          * re-enter the quota code and are already holding the mutex */
1711         if (!dquot_active(inode)) {
1712                 inode_decr_space(inode, number, reserve);
1713                 return;
1714         }
1715
1716         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1717         spin_lock(&dq_data_lock);
1718         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1719                 int wtype;
1720
1721                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1722                 if (!dquots[cnt])
1723                         continue;
1724                 wtype = info_bdq_free(dquots[cnt], number);
1725                 if (wtype != QUOTA_NL_NOWARN)
1726                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1727                 if (reserve)
1728                         dquot_free_reserved_space(dquots[cnt], number);
1729                 else
1730                         dquot_decr_space(dquots[cnt], number);
1731         }
1732         inode_decr_space(inode, number, reserve);
1733         spin_unlock(&dq_data_lock);
1734
1735         if (reserve)
1736                 goto out_unlock;
1737         mark_all_dquot_dirty(dquots);
1738 out_unlock:
1739         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1740         flush_warnings(warn);
1741 }
1742 EXPORT_SYMBOL(__dquot_free_space);
1743
1744 /*
1745  * This operation can block, but only after everything is updated
1746  */
1747 void dquot_free_inode(const struct inode *inode)
1748 {
1749         unsigned int cnt;
1750         struct dquot_warn warn[MAXQUOTAS];
1751         struct dquot * const *dquots = inode->i_dquot;
1752
1753         /* First test before acquiring mutex - solves deadlocks when we
1754          * re-enter the quota code and are already holding the mutex */
1755         if (!dquot_active(inode))
1756                 return;
1757
1758         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1759         spin_lock(&dq_data_lock);
1760         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1761                 int wtype;
1762
1763                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1764                 if (!dquots[cnt])
1765                         continue;
1766                 wtype = info_idq_free(dquots[cnt], 1);
1767                 if (wtype != QUOTA_NL_NOWARN)
1768                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1769                 dquot_decr_inodes(dquots[cnt], 1);
1770         }
1771         spin_unlock(&dq_data_lock);
1772         mark_all_dquot_dirty(dquots);
1773         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1774         flush_warnings(warn);
1775 }
1776 EXPORT_SYMBOL(dquot_free_inode);
1777
1778 /*
1779  * Transfer the number of inode and blocks from one diskquota to an other.
1780  * On success, dquot references in transfer_to are consumed and references
1781  * to original dquots that need to be released are placed there. On failure,
1782  * references are kept untouched.
1783  *
1784  * This operation can block, but only after everything is updated
1785  * A transaction must be started when entering this function.
1786  *
1787  */
1788 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
1789 {
1790         qsize_t space, cur_space;
1791         qsize_t rsv_space = 0;
1792         struct dquot *transfer_from[MAXQUOTAS] = {};
1793         int cnt, ret = 0;
1794         char is_valid[MAXQUOTAS] = {};
1795         struct dquot_warn warn_to[MAXQUOTAS];
1796         struct dquot_warn warn_from_inodes[MAXQUOTAS];
1797         struct dquot_warn warn_from_space[MAXQUOTAS];
1798
1799         /* First test before acquiring mutex - solves deadlocks when we
1800          * re-enter the quota code and are already holding the mutex */
1801         if (IS_NOQUOTA(inode))
1802                 return 0;
1803         /* Initialize the arrays */
1804         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1805                 warn_to[cnt].w_type = QUOTA_NL_NOWARN;
1806                 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN;
1807                 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN;
1808         }
1809         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1810         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1811                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1812                 return 0;
1813         }
1814         spin_lock(&dq_data_lock);
1815         cur_space = inode_get_bytes(inode);
1816         rsv_space = inode_get_rsv_space(inode);
1817         space = cur_space + rsv_space;
1818         /* Build the transfer_from list and check the limits */
1819         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1820                 /*
1821                  * Skip changes for same uid or gid or for turned off quota-type.
1822                  */
1823                 if (!transfer_to[cnt])
1824                         continue;
1825                 /* Avoid races with quotaoff() */
1826                 if (!sb_has_quota_active(inode->i_sb, cnt))
1827                         continue;
1828                 is_valid[cnt] = 1;
1829                 transfer_from[cnt] = inode->i_dquot[cnt];
1830                 ret = check_idq(transfer_to[cnt], 1, &warn_to[cnt]);
1831                 if (ret)
1832                         goto over_quota;
1833                 ret = check_bdq(transfer_to[cnt], space, 0, &warn_to[cnt]);
1834                 if (ret)
1835                         goto over_quota;
1836         }
1837
1838         /*
1839          * Finally perform the needed transfer from transfer_from to transfer_to
1840          */
1841         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1842                 if (!is_valid[cnt])
1843                         continue;
1844                 /* Due to IO error we might not have transfer_from[] structure */
1845                 if (transfer_from[cnt]) {
1846                         int wtype;
1847                         wtype = info_idq_free(transfer_from[cnt], 1);
1848                         if (wtype != QUOTA_NL_NOWARN)
1849                                 prepare_warning(&warn_from_inodes[cnt],
1850                                                 transfer_from[cnt], wtype);
1851                         wtype = info_bdq_free(transfer_from[cnt], space);
1852                         if (wtype != QUOTA_NL_NOWARN)
1853                                 prepare_warning(&warn_from_space[cnt],
1854                                                 transfer_from[cnt], wtype);
1855                         dquot_decr_inodes(transfer_from[cnt], 1);
1856                         dquot_decr_space(transfer_from[cnt], cur_space);
1857                         dquot_free_reserved_space(transfer_from[cnt],
1858                                                   rsv_space);
1859                 }
1860
1861                 dquot_incr_inodes(transfer_to[cnt], 1);
1862                 dquot_incr_space(transfer_to[cnt], cur_space);
1863                 dquot_resv_space(transfer_to[cnt], rsv_space);
1864
1865                 inode->i_dquot[cnt] = transfer_to[cnt];
1866         }
1867         spin_unlock(&dq_data_lock);
1868         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1869
1870         mark_all_dquot_dirty(transfer_from);
1871         mark_all_dquot_dirty(transfer_to);
1872         flush_warnings(warn_to);
1873         flush_warnings(warn_from_inodes);
1874         flush_warnings(warn_from_space);
1875         /* Pass back references to put */
1876         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1877                 if (is_valid[cnt])
1878                         transfer_to[cnt] = transfer_from[cnt];
1879         return 0;
1880 over_quota:
1881         spin_unlock(&dq_data_lock);
1882         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1883         flush_warnings(warn_to);
1884         return ret;
1885 }
1886 EXPORT_SYMBOL(__dquot_transfer);
1887
1888 /* Wrapper for transferring ownership of an inode for uid/gid only
1889  * Called from FSXXX_setattr()
1890  */
1891 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1892 {
1893         struct dquot *transfer_to[MAXQUOTAS] = {};
1894         struct super_block *sb = inode->i_sb;
1895         int ret;
1896
1897         if (!dquot_active(inode))
1898                 return 0;
1899
1900         if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid)
1901                 transfer_to[USRQUOTA] = dqget(sb, iattr->ia_uid, USRQUOTA);
1902         if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)
1903                 transfer_to[GRPQUOTA] = dqget(sb, iattr->ia_gid, GRPQUOTA);
1904
1905         ret = __dquot_transfer(inode, transfer_to);
1906         dqput_all(transfer_to);
1907         return ret;
1908 }
1909 EXPORT_SYMBOL(dquot_transfer);
1910
1911 /*
1912  * Write info of quota file to disk
1913  */
1914 int dquot_commit_info(struct super_block *sb, int type)
1915 {
1916         int ret;
1917         struct quota_info *dqopt = sb_dqopt(sb);
1918
1919         mutex_lock(&dqopt->dqio_mutex);
1920         ret = dqopt->ops[type]->write_file_info(sb, type);
1921         mutex_unlock(&dqopt->dqio_mutex);
1922         return ret;
1923 }
1924 EXPORT_SYMBOL(dquot_commit_info);
1925
1926 /*
1927  * Definitions of diskquota operations.
1928  */
1929 const struct dquot_operations dquot_operations = {
1930         .write_dquot    = dquot_commit,
1931         .acquire_dquot  = dquot_acquire,
1932         .release_dquot  = dquot_release,
1933         .mark_dirty     = dquot_mark_dquot_dirty,
1934         .write_info     = dquot_commit_info,
1935         .alloc_dquot    = dquot_alloc,
1936         .destroy_dquot  = dquot_destroy,
1937 };
1938 EXPORT_SYMBOL(dquot_operations);
1939
1940 /*
1941  * Generic helper for ->open on filesystems supporting disk quotas.
1942  */
1943 int dquot_file_open(struct inode *inode, struct file *file)
1944 {
1945         int error;
1946
1947         error = generic_file_open(inode, file);
1948         if (!error && (file->f_mode & FMODE_WRITE))
1949                 dquot_initialize(inode);
1950         return error;
1951 }
1952 EXPORT_SYMBOL(dquot_file_open);
1953
1954 /*
1955  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1956  */
1957 int dquot_disable(struct super_block *sb, int type, unsigned int flags)
1958 {
1959         int cnt, ret = 0;
1960         struct quota_info *dqopt = sb_dqopt(sb);
1961         struct inode *toputinode[MAXQUOTAS];
1962
1963         /* Cannot turn off usage accounting without turning off limits, or
1964          * suspend quotas and simultaneously turn quotas off. */
1965         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1966             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1967             DQUOT_USAGE_ENABLED)))
1968                 return -EINVAL;
1969
1970         /* We need to serialize quota_off() for device */
1971         mutex_lock(&dqopt->dqonoff_mutex);
1972
1973         /*
1974          * Skip everything if there's nothing to do. We have to do this because
1975          * sometimes we are called when fill_super() failed and calling
1976          * sync_fs() in such cases does no good.
1977          */
1978         if (!sb_any_quota_loaded(sb)) {
1979                 mutex_unlock(&dqopt->dqonoff_mutex);
1980                 return 0;
1981         }
1982         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1983                 toputinode[cnt] = NULL;
1984                 if (type != -1 && cnt != type)
1985                         continue;
1986                 if (!sb_has_quota_loaded(sb, cnt))
1987                         continue;
1988
1989                 if (flags & DQUOT_SUSPENDED) {
1990                         spin_lock(&dq_state_lock);
1991                         dqopt->flags |=
1992                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1993                         spin_unlock(&dq_state_lock);
1994                 } else {
1995                         spin_lock(&dq_state_lock);
1996                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
1997                         /* Turning off suspended quotas? */
1998                         if (!sb_has_quota_loaded(sb, cnt) &&
1999                             sb_has_quota_suspended(sb, cnt)) {
2000                                 dqopt->flags &= ~dquot_state_flag(
2001                                                         DQUOT_SUSPENDED, cnt);
2002                                 spin_unlock(&dq_state_lock);
2003                                 iput(dqopt->files[cnt]);
2004                                 dqopt->files[cnt] = NULL;
2005                                 continue;
2006                         }
2007                         spin_unlock(&dq_state_lock);
2008                 }
2009
2010                 /* We still have to keep quota loaded? */
2011                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
2012                         continue;
2013
2014                 /* Note: these are blocking operations */
2015                 drop_dquot_ref(sb, cnt);
2016                 invalidate_dquots(sb, cnt);
2017                 /*
2018                  * Now all dquots should be invalidated, all writes done so we
2019                  * should be only users of the info. No locks needed.
2020                  */
2021                 if (info_dirty(&dqopt->info[cnt]))
2022                         sb->dq_op->write_info(sb, cnt);
2023                 if (dqopt->ops[cnt]->free_file_info)
2024                         dqopt->ops[cnt]->free_file_info(sb, cnt);
2025                 put_quota_format(dqopt->info[cnt].dqi_format);
2026
2027                 toputinode[cnt] = dqopt->files[cnt];
2028                 if (!sb_has_quota_loaded(sb, cnt))
2029                         dqopt->files[cnt] = NULL;
2030                 dqopt->info[cnt].dqi_flags = 0;
2031                 dqopt->info[cnt].dqi_igrace = 0;
2032                 dqopt->info[cnt].dqi_bgrace = 0;
2033                 dqopt->ops[cnt] = NULL;
2034         }
2035         mutex_unlock(&dqopt->dqonoff_mutex);
2036
2037         /* Skip syncing and setting flags if quota files are hidden */
2038         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
2039                 goto put_inodes;
2040
2041         /* Sync the superblock so that buffers with quota data are written to
2042          * disk (and so userspace sees correct data afterwards). */
2043         if (sb->s_op->sync_fs)
2044                 sb->s_op->sync_fs(sb, 1);
2045         sync_blockdev(sb->s_bdev);
2046         /* Now the quota files are just ordinary files and we can set the
2047          * inode flags back. Moreover we discard the pagecache so that
2048          * userspace sees the writes we did bypassing the pagecache. We
2049          * must also discard the blockdev buffers so that we see the
2050          * changes done by userspace on the next quotaon() */
2051         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2052                 if (toputinode[cnt]) {
2053                         mutex_lock(&dqopt->dqonoff_mutex);
2054                         /* If quota was reenabled in the meantime, we have
2055                          * nothing to do */
2056                         if (!sb_has_quota_loaded(sb, cnt)) {
2057                                 mutex_lock(&toputinode[cnt]->i_mutex);
2058                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
2059                                   S_NOATIME | S_NOQUOTA);
2060                                 truncate_inode_pages(&toputinode[cnt]->i_data,
2061                                                      0);
2062                                 mutex_unlock(&toputinode[cnt]->i_mutex);
2063                                 mark_inode_dirty_sync(toputinode[cnt]);
2064                         }
2065                         mutex_unlock(&dqopt->dqonoff_mutex);
2066                 }
2067         if (sb->s_bdev)
2068                 invalidate_bdev(sb->s_bdev);
2069 put_inodes:
2070         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2071                 if (toputinode[cnt]) {
2072                         /* On remount RO, we keep the inode pointer so that we
2073                          * can reenable quota on the subsequent remount RW. We
2074                          * have to check 'flags' variable and not use sb_has_
2075                          * function because another quotaon / quotaoff could
2076                          * change global state before we got here. We refuse
2077                          * to suspend quotas when there is pending delete on
2078                          * the quota file... */
2079                         if (!(flags & DQUOT_SUSPENDED))
2080                                 iput(toputinode[cnt]);
2081                         else if (!toputinode[cnt]->i_nlink)
2082                                 ret = -EBUSY;
2083                 }
2084         return ret;
2085 }
2086 EXPORT_SYMBOL(dquot_disable);
2087
2088 int dquot_quota_off(struct super_block *sb, int type)
2089 {
2090         return dquot_disable(sb, type,
2091                              DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2092 }
2093 EXPORT_SYMBOL(dquot_quota_off);
2094
2095 /*
2096  *      Turn quotas on on a device
2097  */
2098
2099 /*
2100  * Helper function to turn quotas on when we already have the inode of
2101  * quota file and no quota information is loaded.
2102  */
2103 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2104         unsigned int flags)
2105 {
2106         struct quota_format_type *fmt = find_quota_format(format_id);
2107         struct super_block *sb = inode->i_sb;
2108         struct quota_info *dqopt = sb_dqopt(sb);
2109         int error;
2110         int oldflags = -1;
2111
2112         if (!fmt)
2113                 return -ESRCH;
2114         if (!S_ISREG(inode->i_mode)) {
2115                 error = -EACCES;
2116                 goto out_fmt;
2117         }
2118         if (IS_RDONLY(inode)) {
2119                 error = -EROFS;
2120                 goto out_fmt;
2121         }
2122         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
2123                 error = -EINVAL;
2124                 goto out_fmt;
2125         }
2126         /* Usage always has to be set... */
2127         if (!(flags & DQUOT_USAGE_ENABLED)) {
2128                 error = -EINVAL;
2129                 goto out_fmt;
2130         }
2131
2132         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2133                 /* As we bypass the pagecache we must now flush all the
2134                  * dirty data and invalidate caches so that kernel sees
2135                  * changes from userspace. It is not enough to just flush
2136                  * the quota file since if blocksize < pagesize, invalidation
2137                  * of the cache could fail because of other unrelated dirty
2138                  * data */
2139                 sync_filesystem(sb);
2140                 invalidate_bdev(sb->s_bdev);
2141         }
2142         mutex_lock(&dqopt->dqonoff_mutex);
2143         if (sb_has_quota_loaded(sb, type)) {
2144                 error = -EBUSY;
2145                 goto out_lock;
2146         }
2147
2148         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2149                 /* We don't want quota and atime on quota files (deadlocks
2150                  * possible) Also nobody should write to the file - we use
2151                  * special IO operations which ignore the immutable bit. */
2152                 mutex_lock(&inode->i_mutex);
2153                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2154                                              S_NOQUOTA);
2155                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2156                 mutex_unlock(&inode->i_mutex);
2157                 /*
2158                  * When S_NOQUOTA is set, remove dquot references as no more
2159                  * references can be added
2160                  */
2161                 __dquot_drop(inode);
2162         }
2163
2164         error = -EIO;
2165         dqopt->files[type] = igrab(inode);
2166         if (!dqopt->files[type])
2167                 goto out_lock;
2168         error = -EINVAL;
2169         if (!fmt->qf_ops->check_quota_file(sb, type))
2170                 goto out_file_init;
2171
2172         dqopt->ops[type] = fmt->qf_ops;
2173         dqopt->info[type].dqi_format = fmt;
2174         dqopt->info[type].dqi_fmt_id = format_id;
2175         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2176         mutex_lock(&dqopt->dqio_mutex);
2177         error = dqopt->ops[type]->read_file_info(sb, type);
2178         if (error < 0) {
2179                 mutex_unlock(&dqopt->dqio_mutex);
2180                 goto out_file_init;
2181         }
2182         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
2183                 dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
2184         mutex_unlock(&dqopt->dqio_mutex);
2185         spin_lock(&dq_state_lock);
2186         dqopt->flags |= dquot_state_flag(flags, type);
2187         spin_unlock(&dq_state_lock);
2188
2189         add_dquot_ref(sb, type);
2190         mutex_unlock(&dqopt->dqonoff_mutex);
2191
2192         return 0;
2193
2194 out_file_init:
2195         dqopt->files[type] = NULL;
2196         iput(inode);
2197 out_lock:
2198         if (oldflags != -1) {
2199                 mutex_lock(&inode->i_mutex);
2200                 /* Set the flags back (in the case of accidental quotaon()
2201                  * on a wrong file we don't want to mess up the flags) */
2202                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2203                 inode->i_flags |= oldflags;
2204                 mutex_unlock(&inode->i_mutex);
2205         }
2206         mutex_unlock(&dqopt->dqonoff_mutex);
2207 out_fmt:
2208         put_quota_format(fmt);
2209
2210         return error; 
2211 }
2212
2213 /* Reenable quotas on remount RW */
2214 int dquot_resume(struct super_block *sb, int type)
2215 {
2216         struct quota_info *dqopt = sb_dqopt(sb);
2217         struct inode *inode;
2218         int ret = 0, cnt;
2219         unsigned int flags;
2220
2221         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2222                 if (type != -1 && cnt != type)
2223                         continue;
2224
2225                 mutex_lock(&dqopt->dqonoff_mutex);
2226                 if (!sb_has_quota_suspended(sb, cnt)) {
2227                         mutex_unlock(&dqopt->dqonoff_mutex);
2228                         continue;
2229                 }
2230                 inode = dqopt->files[cnt];
2231                 dqopt->files[cnt] = NULL;
2232                 spin_lock(&dq_state_lock);
2233                 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2234                                                         DQUOT_LIMITS_ENABLED,
2235                                                         cnt);
2236                 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
2237                 spin_unlock(&dq_state_lock);
2238                 mutex_unlock(&dqopt->dqonoff_mutex);
2239
2240                 flags = dquot_generic_flag(flags, cnt);
2241                 ret = vfs_load_quota_inode(inode, cnt,
2242                                 dqopt->info[cnt].dqi_fmt_id, flags);
2243                 iput(inode);
2244         }
2245
2246         return ret;
2247 }
2248 EXPORT_SYMBOL(dquot_resume);
2249
2250 int dquot_quota_on(struct super_block *sb, int type, int format_id,
2251                    struct path *path)
2252 {
2253         int error = security_quota_on(path->dentry);
2254         if (error)
2255                 return error;
2256         /* Quota file not on the same filesystem? */
2257         if (path->dentry->d_sb != sb)
2258                 error = -EXDEV;
2259         else
2260                 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2261                                              format_id, DQUOT_USAGE_ENABLED |
2262                                              DQUOT_LIMITS_ENABLED);
2263         return error;
2264 }
2265 EXPORT_SYMBOL(dquot_quota_on);
2266
2267 /*
2268  * More powerful function for turning on quotas allowing setting
2269  * of individual quota flags
2270  */
2271 int dquot_enable(struct inode *inode, int type, int format_id,
2272                  unsigned int flags)
2273 {
2274         int ret = 0;
2275         struct super_block *sb = inode->i_sb;
2276         struct quota_info *dqopt = sb_dqopt(sb);
2277
2278         /* Just unsuspend quotas? */
2279         BUG_ON(flags & DQUOT_SUSPENDED);
2280
2281         if (!flags)
2282                 return 0;
2283         /* Just updating flags needed? */
2284         if (sb_has_quota_loaded(sb, type)) {
2285                 mutex_lock(&dqopt->dqonoff_mutex);
2286                 /* Now do a reliable test... */
2287                 if (!sb_has_quota_loaded(sb, type)) {
2288                         mutex_unlock(&dqopt->dqonoff_mutex);
2289                         goto load_quota;
2290                 }
2291                 if (flags & DQUOT_USAGE_ENABLED &&
2292                     sb_has_quota_usage_enabled(sb, type)) {
2293                         ret = -EBUSY;
2294                         goto out_lock;
2295                 }
2296                 if (flags & DQUOT_LIMITS_ENABLED &&
2297                     sb_has_quota_limits_enabled(sb, type)) {
2298                         ret = -EBUSY;
2299                         goto out_lock;
2300                 }
2301                 spin_lock(&dq_state_lock);
2302                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2303                 spin_unlock(&dq_state_lock);
2304 out_lock:
2305                 mutex_unlock(&dqopt->dqonoff_mutex);
2306                 return ret;
2307         }
2308
2309 load_quota:
2310         return vfs_load_quota_inode(inode, type, format_id, flags);
2311 }
2312 EXPORT_SYMBOL(dquot_enable);
2313
2314 /*
2315  * This function is used when filesystem needs to initialize quotas
2316  * during mount time.
2317  */
2318 int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
2319                 int format_id, int type)
2320 {
2321         struct dentry *dentry;
2322         int error;
2323
2324         mutex_lock(&sb->s_root->d_inode->i_mutex);
2325         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2326         mutex_unlock(&sb->s_root->d_inode->i_mutex);
2327         if (IS_ERR(dentry))
2328                 return PTR_ERR(dentry);
2329
2330         if (!dentry->d_inode) {
2331                 error = -ENOENT;
2332                 goto out;
2333         }
2334
2335         error = security_quota_on(dentry);
2336         if (!error)
2337                 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2338                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2339
2340 out:
2341         dput(dentry);
2342         return error;
2343 }
2344 EXPORT_SYMBOL(dquot_quota_on_mount);
2345
2346 static inline qsize_t qbtos(qsize_t blocks)
2347 {
2348         return blocks << QIF_DQBLKSIZE_BITS;
2349 }
2350
2351 static inline qsize_t stoqb(qsize_t space)
2352 {
2353         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2354 }
2355
2356 /* Generic routine for getting common part of quota structure */
2357 static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
2358 {
2359         struct mem_dqblk *dm = &dquot->dq_dqb;
2360
2361         memset(di, 0, sizeof(*di));
2362         di->d_version = FS_DQUOT_VERSION;
2363         di->d_flags = dquot->dq_type == USRQUOTA ?
2364                         FS_USER_QUOTA : FS_GROUP_QUOTA;
2365         di->d_id = dquot->dq_id;
2366
2367         spin_lock(&dq_data_lock);
2368         di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit);
2369         di->d_blk_softlimit = stoqb(dm->dqb_bsoftlimit);
2370         di->d_ino_hardlimit = dm->dqb_ihardlimit;
2371         di->d_ino_softlimit = dm->dqb_isoftlimit;
2372         di->d_bcount = dm->dqb_curspace + dm->dqb_rsvspace;
2373         di->d_icount = dm->dqb_curinodes;
2374         di->d_btimer = dm->dqb_btime;
2375         di->d_itimer = dm->dqb_itime;
2376         spin_unlock(&dq_data_lock);
2377 }
2378
2379 int dquot_get_dqblk(struct super_block *sb, int type, qid_t id,
2380                     struct fs_disk_quota *di)
2381 {
2382         struct dquot *dquot;
2383
2384         dquot = dqget(sb, id, type);
2385         if (!dquot)
2386                 return -ESRCH;
2387         do_get_dqblk(dquot, di);
2388         dqput(dquot);
2389
2390         return 0;
2391 }
2392 EXPORT_SYMBOL(dquot_get_dqblk);
2393
2394 #define VFS_FS_DQ_MASK \
2395         (FS_DQ_BCOUNT | FS_DQ_BSOFT | FS_DQ_BHARD | \
2396          FS_DQ_ICOUNT | FS_DQ_ISOFT | FS_DQ_IHARD | \
2397          FS_DQ_BTIMER | FS_DQ_ITIMER)
2398
2399 /* Generic routine for setting common part of quota structure */
2400 static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
2401 {
2402         struct mem_dqblk *dm = &dquot->dq_dqb;
2403         int check_blim = 0, check_ilim = 0;
2404         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2405
2406         if (di->d_fieldmask & ~VFS_FS_DQ_MASK)
2407                 return -EINVAL;
2408
2409         if (((di->d_fieldmask & FS_DQ_BSOFT) &&
2410              (di->d_blk_softlimit > dqi->dqi_maxblimit)) ||
2411             ((di->d_fieldmask & FS_DQ_BHARD) &&
2412              (di->d_blk_hardlimit > dqi->dqi_maxblimit)) ||
2413             ((di->d_fieldmask & FS_DQ_ISOFT) &&
2414              (di->d_ino_softlimit > dqi->dqi_maxilimit)) ||
2415             ((di->d_fieldmask & FS_DQ_IHARD) &&
2416              (di->d_ino_hardlimit > dqi->dqi_maxilimit)))
2417                 return -ERANGE;
2418
2419         spin_lock(&dq_data_lock);
2420         if (di->d_fieldmask & FS_DQ_BCOUNT) {
2421                 dm->dqb_curspace = di->d_bcount - dm->dqb_rsvspace;
2422                 check_blim = 1;
2423                 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2424         }
2425
2426         if (di->d_fieldmask & FS_DQ_BSOFT)
2427                 dm->dqb_bsoftlimit = qbtos(di->d_blk_softlimit);
2428         if (di->d_fieldmask & FS_DQ_BHARD)
2429                 dm->dqb_bhardlimit = qbtos(di->d_blk_hardlimit);
2430         if (di->d_fieldmask & (FS_DQ_BSOFT | FS_DQ_BHARD)) {
2431                 check_blim = 1;
2432                 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2433         }
2434
2435         if (di->d_fieldmask & FS_DQ_ICOUNT) {
2436                 dm->dqb_curinodes = di->d_icount;
2437                 check_ilim = 1;
2438                 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2439         }
2440
2441         if (di->d_fieldmask & FS_DQ_ISOFT)
2442                 dm->dqb_isoftlimit = di->d_ino_softlimit;
2443         if (di->d_fieldmask & FS_DQ_IHARD)
2444                 dm->dqb_ihardlimit = di->d_ino_hardlimit;
2445         if (di->d_fieldmask & (FS_DQ_ISOFT | FS_DQ_IHARD)) {
2446                 check_ilim = 1;
2447                 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2448         }
2449
2450         if (di->d_fieldmask & FS_DQ_BTIMER) {
2451                 dm->dqb_btime = di->d_btimer;
2452                 check_blim = 1;
2453                 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2454         }
2455
2456         if (di->d_fieldmask & FS_DQ_ITIMER) {
2457                 dm->dqb_itime = di->d_itimer;
2458                 check_ilim = 1;
2459                 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2460         }
2461
2462         if (check_blim) {
2463                 if (!dm->dqb_bsoftlimit ||
2464                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2465                         dm->dqb_btime = 0;
2466                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2467                 } else if (!(di->d_fieldmask & FS_DQ_BTIMER))
2468                         /* Set grace only if user hasn't provided his own... */
2469                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2470         }
2471         if (check_ilim) {
2472                 if (!dm->dqb_isoftlimit ||
2473                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2474                         dm->dqb_itime = 0;
2475                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2476                 } else if (!(di->d_fieldmask & FS_DQ_ITIMER))
2477                         /* Set grace only if user hasn't provided his own... */
2478                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2479         }
2480         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2481             dm->dqb_isoftlimit)
2482                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2483         else
2484                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2485         spin_unlock(&dq_data_lock);
2486         mark_dquot_dirty(dquot);
2487
2488         return 0;
2489 }
2490
2491 int dquot_set_dqblk(struct super_block *sb, int type, qid_t id,
2492                   struct fs_disk_quota *di)
2493 {
2494         struct dquot *dquot;
2495         int rc;
2496
2497         dquot = dqget(sb, id, type);
2498         if (!dquot) {
2499                 rc = -ESRCH;
2500                 goto out;
2501         }
2502         rc = do_set_dqblk(dquot, di);
2503         dqput(dquot);
2504 out:
2505         return rc;
2506 }
2507 EXPORT_SYMBOL(dquot_set_dqblk);
2508
2509 /* Generic routine for getting common part of quota file information */
2510 int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2511 {
2512         struct mem_dqinfo *mi;
2513   
2514         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2515         if (!sb_has_quota_active(sb, type)) {
2516                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2517                 return -ESRCH;
2518         }
2519         mi = sb_dqopt(sb)->info + type;
2520         spin_lock(&dq_data_lock);
2521         ii->dqi_bgrace = mi->dqi_bgrace;
2522         ii->dqi_igrace = mi->dqi_igrace;
2523         ii->dqi_flags = mi->dqi_flags & DQF_GETINFO_MASK;
2524         ii->dqi_valid = IIF_ALL;
2525         spin_unlock(&dq_data_lock);
2526         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2527         return 0;
2528 }
2529 EXPORT_SYMBOL(dquot_get_dqinfo);
2530
2531 /* Generic routine for setting common part of quota file information */
2532 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2533 {
2534         struct mem_dqinfo *mi;
2535         int err = 0;
2536
2537         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2538         if (!sb_has_quota_active(sb, type)) {
2539                 err = -ESRCH;
2540                 goto out;
2541         }
2542         mi = sb_dqopt(sb)->info + type;
2543         spin_lock(&dq_data_lock);
2544         if (ii->dqi_valid & IIF_BGRACE)
2545                 mi->dqi_bgrace = ii->dqi_bgrace;
2546         if (ii->dqi_valid & IIF_IGRACE)
2547                 mi->dqi_igrace = ii->dqi_igrace;
2548         if (ii->dqi_valid & IIF_FLAGS)
2549                 mi->dqi_flags = (mi->dqi_flags & ~DQF_SETINFO_MASK) |
2550                                 (ii->dqi_flags & DQF_SETINFO_MASK);
2551         spin_unlock(&dq_data_lock);
2552         mark_info_dirty(sb, type);
2553         /* Force write to disk */
2554         sb->dq_op->write_info(sb, type);
2555 out:
2556         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2557         return err;
2558 }
2559 EXPORT_SYMBOL(dquot_set_dqinfo);
2560
2561 const struct quotactl_ops dquot_quotactl_ops = {
2562         .quota_on       = dquot_quota_on,
2563         .quota_off      = dquot_quota_off,
2564         .quota_sync     = dquot_quota_sync,
2565         .get_info       = dquot_get_dqinfo,
2566         .set_info       = dquot_set_dqinfo,
2567         .get_dqblk      = dquot_get_dqblk,
2568         .set_dqblk      = dquot_set_dqblk
2569 };
2570 EXPORT_SYMBOL(dquot_quotactl_ops);
2571
2572 static int do_proc_dqstats(struct ctl_table *table, int write,
2573                      void __user *buffer, size_t *lenp, loff_t *ppos)
2574 {
2575         unsigned int type = (int *)table->data - dqstats.stat;
2576
2577         /* Update global table */
2578         dqstats.stat[type] =
2579                         percpu_counter_sum_positive(&dqstats.counter[type]);
2580         return proc_dointvec(table, write, buffer, lenp, ppos);
2581 }
2582
2583 static ctl_table fs_dqstats_table[] = {
2584         {
2585                 .procname       = "lookups",
2586                 .data           = &dqstats.stat[DQST_LOOKUPS],
2587                 .maxlen         = sizeof(int),
2588                 .mode           = 0444,
2589                 .proc_handler   = do_proc_dqstats,
2590         },
2591         {
2592                 .procname       = "drops",
2593                 .data           = &dqstats.stat[DQST_DROPS],
2594                 .maxlen         = sizeof(int),
2595                 .mode           = 0444,
2596                 .proc_handler   = do_proc_dqstats,
2597         },
2598         {
2599                 .procname       = "reads",
2600                 .data           = &dqstats.stat[DQST_READS],
2601                 .maxlen         = sizeof(int),
2602                 .mode           = 0444,
2603                 .proc_handler   = do_proc_dqstats,
2604         },
2605         {
2606                 .procname       = "writes",
2607                 .data           = &dqstats.stat[DQST_WRITES],
2608                 .maxlen         = sizeof(int),
2609                 .mode           = 0444,
2610                 .proc_handler   = do_proc_dqstats,
2611         },
2612         {
2613                 .procname       = "cache_hits",
2614                 .data           = &dqstats.stat[DQST_CACHE_HITS],
2615                 .maxlen         = sizeof(int),
2616                 .mode           = 0444,
2617                 .proc_handler   = do_proc_dqstats,
2618         },
2619         {
2620                 .procname       = "allocated_dquots",
2621                 .data           = &dqstats.stat[DQST_ALLOC_DQUOTS],
2622                 .maxlen         = sizeof(int),
2623                 .mode           = 0444,
2624                 .proc_handler   = do_proc_dqstats,
2625         },
2626         {
2627                 .procname       = "free_dquots",
2628                 .data           = &dqstats.stat[DQST_FREE_DQUOTS],
2629                 .maxlen         = sizeof(int),
2630                 .mode           = 0444,
2631                 .proc_handler   = do_proc_dqstats,
2632         },
2633         {
2634                 .procname       = "syncs",
2635                 .data           = &dqstats.stat[DQST_SYNCS],
2636                 .maxlen         = sizeof(int),
2637                 .mode           = 0444,
2638                 .proc_handler   = do_proc_dqstats,
2639         },
2640 #ifdef CONFIG_PRINT_QUOTA_WARNING
2641         {
2642                 .procname       = "warnings",
2643                 .data           = &flag_print_warnings,
2644                 .maxlen         = sizeof(int),
2645                 .mode           = 0644,
2646                 .proc_handler   = proc_dointvec,
2647         },
2648 #endif
2649         { },
2650 };
2651
2652 static ctl_table fs_table[] = {
2653         {
2654                 .procname       = "quota",
2655                 .mode           = 0555,
2656                 .child          = fs_dqstats_table,
2657         },
2658         { },
2659 };
2660
2661 static ctl_table sys_table[] = {
2662         {
2663                 .procname       = "fs",
2664                 .mode           = 0555,
2665                 .child          = fs_table,
2666         },
2667         { },
2668 };
2669
2670 static int __init dquot_init(void)
2671 {
2672         int i, ret;
2673         unsigned long nr_hash, order;
2674
2675         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2676
2677         register_sysctl_table(sys_table);
2678
2679         dquot_cachep = kmem_cache_create("dquot",
2680                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2681                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2682                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2683                         NULL);
2684
2685         order = 0;
2686         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2687         if (!dquot_hash)
2688                 panic("Cannot create dquot hash table");
2689
2690         for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
2691                 ret = percpu_counter_init(&dqstats.counter[i], 0);
2692                 if (ret)
2693                         panic("Cannot create dquot stat counters");
2694         }
2695
2696         /* Find power-of-two hlist_heads which can fit into allocation */
2697         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2698         dq_hash_bits = 0;
2699         do {
2700                 dq_hash_bits++;
2701         } while (nr_hash >> dq_hash_bits);
2702         dq_hash_bits--;
2703
2704         nr_hash = 1UL << dq_hash_bits;
2705         dq_hash_mask = nr_hash - 1;
2706         for (i = 0; i < nr_hash; i++)
2707                 INIT_HLIST_HEAD(dquot_hash + i);
2708
2709         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2710                         nr_hash, order, (PAGE_SIZE << order));
2711
2712         register_shrinker(&dqcache_shrinker);
2713
2714         return 0;
2715 }
2716 module_init(dquot_init);