]> git.kernelconcepts.de Git - karo-tx-linux.git/blob - fs/quota/dquot.c
ASoC: max98095: a couple array underflows
[karo-tx-linux.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, struct kqid qid)
257 {
258         unsigned int id = from_kqid(&init_user_ns, qid);
259         int type = qid.type;
260         unsigned long tmp;
261
262         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
263         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
264 }
265
266 /*
267  * Following list functions expect dq_list_lock to be held
268  */
269 static inline void insert_dquot_hash(struct dquot *dquot)
270 {
271         struct hlist_head *head;
272         head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id);
273         hlist_add_head(&dquot->dq_hash, head);
274 }
275
276 static inline void remove_dquot_hash(struct dquot *dquot)
277 {
278         hlist_del_init(&dquot->dq_hash);
279 }
280
281 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
282                                 struct kqid qid)
283 {
284         struct hlist_node *node;
285         struct dquot *dquot;
286
287         hlist_for_each (node, dquot_hash+hashent) {
288                 dquot = hlist_entry(node, struct dquot, dq_hash);
289                 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid))
290                         return dquot;
291         }
292         return NULL;
293 }
294
295 /* Add a dquot to the tail of the free list */
296 static inline void put_dquot_last(struct dquot *dquot)
297 {
298         list_add_tail(&dquot->dq_free, &free_dquots);
299         dqstats_inc(DQST_FREE_DQUOTS);
300 }
301
302 static inline void remove_free_dquot(struct dquot *dquot)
303 {
304         if (list_empty(&dquot->dq_free))
305                 return;
306         list_del_init(&dquot->dq_free);
307         dqstats_dec(DQST_FREE_DQUOTS);
308 }
309
310 static inline void put_inuse(struct dquot *dquot)
311 {
312         /* We add to the back of inuse list so we don't have to restart
313          * when traversing this list and we block */
314         list_add_tail(&dquot->dq_inuse, &inuse_list);
315         dqstats_inc(DQST_ALLOC_DQUOTS);
316 }
317
318 static inline void remove_inuse(struct dquot *dquot)
319 {
320         dqstats_dec(DQST_ALLOC_DQUOTS);
321         list_del(&dquot->dq_inuse);
322 }
323 /*
324  * End of list functions needing dq_list_lock
325  */
326
327 static void wait_on_dquot(struct dquot *dquot)
328 {
329         mutex_lock(&dquot->dq_lock);
330         mutex_unlock(&dquot->dq_lock);
331 }
332
333 static inline int dquot_dirty(struct dquot *dquot)
334 {
335         return test_bit(DQ_MOD_B, &dquot->dq_flags);
336 }
337
338 static inline int mark_dquot_dirty(struct dquot *dquot)
339 {
340         return dquot->dq_sb->dq_op->mark_dirty(dquot);
341 }
342
343 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */
344 int dquot_mark_dquot_dirty(struct dquot *dquot)
345 {
346         int ret = 1;
347
348         /* If quota is dirty already, we don't have to acquire dq_list_lock */
349         if (test_bit(DQ_MOD_B, &dquot->dq_flags))
350                 return 1;
351
352         spin_lock(&dq_list_lock);
353         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) {
354                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
355                                 info[dquot->dq_id.type].dqi_dirty_list);
356                 ret = 0;
357         }
358         spin_unlock(&dq_list_lock);
359         return ret;
360 }
361 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
362
363 /* Dirtify all the dquots - this can block when journalling */
364 static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
365 {
366         int ret, err, cnt;
367
368         ret = err = 0;
369         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
370                 if (dquot[cnt])
371                         /* Even in case of error we have to continue */
372                         ret = mark_dquot_dirty(dquot[cnt]);
373                 if (!err)
374                         err = ret;
375         }
376         return err;
377 }
378
379 static inline void dqput_all(struct dquot **dquot)
380 {
381         unsigned int cnt;
382
383         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
384                 dqput(dquot[cnt]);
385 }
386
387 /* This function needs dq_list_lock */
388 static inline int clear_dquot_dirty(struct dquot *dquot)
389 {
390         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
391                 return 0;
392         list_del_init(&dquot->dq_dirty);
393         return 1;
394 }
395
396 void mark_info_dirty(struct super_block *sb, int type)
397 {
398         set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
399 }
400 EXPORT_SYMBOL(mark_info_dirty);
401
402 /*
403  *      Read dquot from disk and alloc space for it
404  */
405
406 int dquot_acquire(struct dquot *dquot)
407 {
408         int ret = 0, ret2 = 0;
409         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
410
411         mutex_lock(&dquot->dq_lock);
412         mutex_lock(&dqopt->dqio_mutex);
413         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
414                 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
415         if (ret < 0)
416                 goto out_iolock;
417         set_bit(DQ_READ_B, &dquot->dq_flags);
418         /* Instantiate dquot if needed */
419         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
420                 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
421                 /* Write the info if needed */
422                 if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
423                         ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
424                                         dquot->dq_sb, dquot->dq_id.type);
425                 }
426                 if (ret < 0)
427                         goto out_iolock;
428                 if (ret2 < 0) {
429                         ret = ret2;
430                         goto out_iolock;
431                 }
432         }
433         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
434 out_iolock:
435         mutex_unlock(&dqopt->dqio_mutex);
436         mutex_unlock(&dquot->dq_lock);
437         return ret;
438 }
439 EXPORT_SYMBOL(dquot_acquire);
440
441 /*
442  *      Write dquot to disk
443  */
444 int dquot_commit(struct dquot *dquot)
445 {
446         int ret = 0;
447         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
448
449         mutex_lock(&dqopt->dqio_mutex);
450         spin_lock(&dq_list_lock);
451         if (!clear_dquot_dirty(dquot)) {
452                 spin_unlock(&dq_list_lock);
453                 goto out_sem;
454         }
455         spin_unlock(&dq_list_lock);
456         /* Inactive dquot can be only if there was error during read/init
457          * => we have better not writing it */
458         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
459                 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
460         else
461                 ret = -EIO;
462 out_sem:
463         mutex_unlock(&dqopt->dqio_mutex);
464         return ret;
465 }
466 EXPORT_SYMBOL(dquot_commit);
467
468 /*
469  *      Release dquot
470  */
471 int dquot_release(struct dquot *dquot)
472 {
473         int ret = 0, ret2 = 0;
474         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
475
476         mutex_lock(&dquot->dq_lock);
477         /* Check whether we are not racing with some other dqget() */
478         if (atomic_read(&dquot->dq_count) > 1)
479                 goto out_dqlock;
480         mutex_lock(&dqopt->dqio_mutex);
481         if (dqopt->ops[dquot->dq_id.type]->release_dqblk) {
482                 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot);
483                 /* Write the info */
484                 if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
485                         ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
486                                                 dquot->dq_sb, dquot->dq_id.type);
487                 }
488                 if (ret >= 0)
489                         ret = ret2;
490         }
491         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
492         mutex_unlock(&dqopt->dqio_mutex);
493 out_dqlock:
494         mutex_unlock(&dquot->dq_lock);
495         return ret;
496 }
497 EXPORT_SYMBOL(dquot_release);
498
499 void dquot_destroy(struct dquot *dquot)
500 {
501         kmem_cache_free(dquot_cachep, dquot);
502 }
503 EXPORT_SYMBOL(dquot_destroy);
504
505 static inline void do_destroy_dquot(struct dquot *dquot)
506 {
507         dquot->dq_sb->dq_op->destroy_dquot(dquot);
508 }
509
510 /* Invalidate all dquots on the list. Note that this function is called after
511  * quota is disabled and pointers from inodes removed so there cannot be new
512  * quota users. There can still be some users of quotas due to inodes being
513  * just deleted or pruned by prune_icache() (those are not attached to any
514  * list) or parallel quotactl call. We have to wait for such users.
515  */
516 static void invalidate_dquots(struct super_block *sb, int type)
517 {
518         struct dquot *dquot, *tmp;
519
520 restart:
521         spin_lock(&dq_list_lock);
522         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
523                 if (dquot->dq_sb != sb)
524                         continue;
525                 if (dquot->dq_id.type != type)
526                         continue;
527                 /* Wait for dquot users */
528                 if (atomic_read(&dquot->dq_count)) {
529                         DEFINE_WAIT(wait);
530
531                         atomic_inc(&dquot->dq_count);
532                         prepare_to_wait(&dquot->dq_wait_unused, &wait,
533                                         TASK_UNINTERRUPTIBLE);
534                         spin_unlock(&dq_list_lock);
535                         /* Once dqput() wakes us up, we know it's time to free
536                          * the dquot.
537                          * IMPORTANT: we rely on the fact that there is always
538                          * at most one process waiting for dquot to free.
539                          * Otherwise dq_count would be > 1 and we would never
540                          * wake up.
541                          */
542                         if (atomic_read(&dquot->dq_count) > 1)
543                                 schedule();
544                         finish_wait(&dquot->dq_wait_unused, &wait);
545                         dqput(dquot);
546                         /* At this moment dquot() need not exist (it could be
547                          * reclaimed by prune_dqcache(). Hence we must
548                          * restart. */
549                         goto restart;
550                 }
551                 /*
552                  * Quota now has no users and it has been written on last
553                  * dqput()
554                  */
555                 remove_dquot_hash(dquot);
556                 remove_free_dquot(dquot);
557                 remove_inuse(dquot);
558                 do_destroy_dquot(dquot);
559         }
560         spin_unlock(&dq_list_lock);
561 }
562
563 /* Call callback for every active dquot on given filesystem */
564 int dquot_scan_active(struct super_block *sb,
565                       int (*fn)(struct dquot *dquot, unsigned long priv),
566                       unsigned long priv)
567 {
568         struct dquot *dquot, *old_dquot = NULL;
569         int ret = 0;
570
571         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
572         spin_lock(&dq_list_lock);
573         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
574                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
575                         continue;
576                 if (dquot->dq_sb != sb)
577                         continue;
578                 /* Now we have active dquot so we can just increase use count */
579                 atomic_inc(&dquot->dq_count);
580                 spin_unlock(&dq_list_lock);
581                 dqstats_inc(DQST_LOOKUPS);
582                 dqput(old_dquot);
583                 old_dquot = dquot;
584                 ret = fn(dquot, priv);
585                 if (ret < 0)
586                         goto out;
587                 spin_lock(&dq_list_lock);
588                 /* We are safe to continue now because our dquot could not
589                  * be moved out of the inuse list while we hold the reference */
590         }
591         spin_unlock(&dq_list_lock);
592 out:
593         dqput(old_dquot);
594         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
595         return ret;
596 }
597 EXPORT_SYMBOL(dquot_scan_active);
598
599 /* Write all dquot structures to quota files */
600 int dquot_writeback_dquots(struct super_block *sb, int type)
601 {
602         struct list_head *dirty;
603         struct dquot *dquot;
604         struct quota_info *dqopt = sb_dqopt(sb);
605         int cnt;
606         int err, ret = 0;
607
608         mutex_lock(&dqopt->dqonoff_mutex);
609         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
610                 if (type != -1 && cnt != type)
611                         continue;
612                 if (!sb_has_quota_active(sb, cnt))
613                         continue;
614                 spin_lock(&dq_list_lock);
615                 dirty = &dqopt->info[cnt].dqi_dirty_list;
616                 while (!list_empty(dirty)) {
617                         dquot = list_first_entry(dirty, struct dquot,
618                                                  dq_dirty);
619                         /* Dirty and inactive can be only bad dquot... */
620                         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
621                                 clear_dquot_dirty(dquot);
622                                 continue;
623                         }
624                         /* Now we have active dquot from which someone is
625                          * holding reference so we can safely just increase
626                          * use count */
627                         atomic_inc(&dquot->dq_count);
628                         spin_unlock(&dq_list_lock);
629                         dqstats_inc(DQST_LOOKUPS);
630                         err = sb->dq_op->write_dquot(dquot);
631                         if (!ret && err)
632                                 err = ret;
633                         dqput(dquot);
634                         spin_lock(&dq_list_lock);
635                 }
636                 spin_unlock(&dq_list_lock);
637         }
638
639         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
640                 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
641                     && info_dirty(&dqopt->info[cnt]))
642                         sb->dq_op->write_info(sb, cnt);
643         dqstats_inc(DQST_SYNCS);
644         mutex_unlock(&dqopt->dqonoff_mutex);
645
646         return ret;
647 }
648 EXPORT_SYMBOL(dquot_writeback_dquots);
649
650 /* Write all dquot structures to disk and make them visible from userspace */
651 int dquot_quota_sync(struct super_block *sb, int type)
652 {
653         struct quota_info *dqopt = sb_dqopt(sb);
654         int cnt;
655         int ret;
656
657         ret = dquot_writeback_dquots(sb, type);
658         if (ret)
659                 return ret;
660         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
661                 return 0;
662
663         /* This is not very clever (and fast) but currently I don't know about
664          * any other simple way of getting quota data to disk and we must get
665          * them there for userspace to be visible... */
666         if (sb->s_op->sync_fs)
667                 sb->s_op->sync_fs(sb, 1);
668         sync_blockdev(sb->s_bdev);
669
670         /*
671          * Now when everything is written we can discard the pagecache so
672          * that userspace sees the changes.
673          */
674         mutex_lock(&dqopt->dqonoff_mutex);
675         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
676                 if (type != -1 && cnt != type)
677                         continue;
678                 if (!sb_has_quota_active(sb, cnt))
679                         continue;
680                 mutex_lock(&dqopt->files[cnt]->i_mutex);
681                 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
682                 mutex_unlock(&dqopt->files[cnt]->i_mutex);
683         }
684         mutex_unlock(&dqopt->dqonoff_mutex);
685
686         return 0;
687 }
688 EXPORT_SYMBOL(dquot_quota_sync);
689
690 /* Free unused dquots from cache */
691 static void prune_dqcache(int count)
692 {
693         struct list_head *head;
694         struct dquot *dquot;
695
696         head = free_dquots.prev;
697         while (head != &free_dquots && count) {
698                 dquot = list_entry(head, struct dquot, dq_free);
699                 remove_dquot_hash(dquot);
700                 remove_free_dquot(dquot);
701                 remove_inuse(dquot);
702                 do_destroy_dquot(dquot);
703                 count--;
704                 head = free_dquots.prev;
705         }
706 }
707
708 /*
709  * This is called from kswapd when we think we need some
710  * more memory
711  */
712 static int shrink_dqcache_memory(struct shrinker *shrink,
713                                  struct shrink_control *sc)
714 {
715         int nr = sc->nr_to_scan;
716
717         if (nr) {
718                 spin_lock(&dq_list_lock);
719                 prune_dqcache(nr);
720                 spin_unlock(&dq_list_lock);
721         }
722         return ((unsigned)
723                 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])
724                 /100) * sysctl_vfs_cache_pressure;
725 }
726
727 static struct shrinker dqcache_shrinker = {
728         .shrink = shrink_dqcache_memory,
729         .seeks = DEFAULT_SEEKS,
730 };
731
732 /*
733  * Put reference to dquot
734  * NOTE: If you change this function please check whether dqput_blocks() works right...
735  */
736 void dqput(struct dquot *dquot)
737 {
738         int ret;
739
740         if (!dquot)
741                 return;
742 #ifdef CONFIG_QUOTA_DEBUG
743         if (!atomic_read(&dquot->dq_count)) {
744                 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d",
745                             quotatypes[dquot->dq_id.type],
746                             from_kqid(&init_user_ns, dquot->dq_id));
747                 BUG();
748         }
749 #endif
750         dqstats_inc(DQST_DROPS);
751 we_slept:
752         spin_lock(&dq_list_lock);
753         if (atomic_read(&dquot->dq_count) > 1) {
754                 /* We have more than one user... nothing to do */
755                 atomic_dec(&dquot->dq_count);
756                 /* Releasing dquot during quotaoff phase? */
757                 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) &&
758                     atomic_read(&dquot->dq_count) == 1)
759                         wake_up(&dquot->dq_wait_unused);
760                 spin_unlock(&dq_list_lock);
761                 return;
762         }
763         /* Need to release dquot? */
764         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
765                 spin_unlock(&dq_list_lock);
766                 /* Commit dquot before releasing */
767                 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
768                 if (ret < 0) {
769                         quota_error(dquot->dq_sb, "Can't write quota structure"
770                                     " (error %d). Quota may get out of sync!",
771                                     ret);
772                         /*
773                          * We clear dirty bit anyway, so that we avoid
774                          * infinite loop here
775                          */
776                         spin_lock(&dq_list_lock);
777                         clear_dquot_dirty(dquot);
778                         spin_unlock(&dq_list_lock);
779                 }
780                 goto we_slept;
781         }
782         /* Clear flag in case dquot was inactive (something bad happened) */
783         clear_dquot_dirty(dquot);
784         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
785                 spin_unlock(&dq_list_lock);
786                 dquot->dq_sb->dq_op->release_dquot(dquot);
787                 goto we_slept;
788         }
789         atomic_dec(&dquot->dq_count);
790 #ifdef CONFIG_QUOTA_DEBUG
791         /* sanity check */
792         BUG_ON(!list_empty(&dquot->dq_free));
793 #endif
794         put_dquot_last(dquot);
795         spin_unlock(&dq_list_lock);
796 }
797 EXPORT_SYMBOL(dqput);
798
799 struct dquot *dquot_alloc(struct super_block *sb, int type)
800 {
801         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
802 }
803 EXPORT_SYMBOL(dquot_alloc);
804
805 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
806 {
807         struct dquot *dquot;
808
809         dquot = sb->dq_op->alloc_dquot(sb, type);
810         if(!dquot)
811                 return NULL;
812
813         mutex_init(&dquot->dq_lock);
814         INIT_LIST_HEAD(&dquot->dq_free);
815         INIT_LIST_HEAD(&dquot->dq_inuse);
816         INIT_HLIST_NODE(&dquot->dq_hash);
817         INIT_LIST_HEAD(&dquot->dq_dirty);
818         init_waitqueue_head(&dquot->dq_wait_unused);
819         dquot->dq_sb = sb;
820         dquot->dq_id = make_kqid_invalid(type);
821         atomic_set(&dquot->dq_count, 1);
822
823         return dquot;
824 }
825
826 /*
827  * Get reference to dquot
828  *
829  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
830  * destroying our dquot by:
831  *   a) checking for quota flags under dq_list_lock and
832  *   b) getting a reference to dquot before we release dq_list_lock
833  */
834 struct dquot *dqget(struct super_block *sb, struct kqid qid)
835 {
836         unsigned int hashent = hashfn(sb, qid);
837         struct dquot *dquot = NULL, *empty = NULL;
838
839         if (!sb_has_quota_active(sb, qid.type))
840                 return NULL;
841 we_slept:
842         spin_lock(&dq_list_lock);
843         spin_lock(&dq_state_lock);
844         if (!sb_has_quota_active(sb, qid.type)) {
845                 spin_unlock(&dq_state_lock);
846                 spin_unlock(&dq_list_lock);
847                 goto out;
848         }
849         spin_unlock(&dq_state_lock);
850
851         dquot = find_dquot(hashent, sb, qid);
852         if (!dquot) {
853                 if (!empty) {
854                         spin_unlock(&dq_list_lock);
855                         empty = get_empty_dquot(sb, qid.type);
856                         if (!empty)
857                                 schedule();     /* Try to wait for a moment... */
858                         goto we_slept;
859                 }
860                 dquot = empty;
861                 empty = NULL;
862                 dquot->dq_id = qid;
863                 /* all dquots go on the inuse_list */
864                 put_inuse(dquot);
865                 /* hash it first so it can be found */
866                 insert_dquot_hash(dquot);
867                 spin_unlock(&dq_list_lock);
868                 dqstats_inc(DQST_LOOKUPS);
869         } else {
870                 if (!atomic_read(&dquot->dq_count))
871                         remove_free_dquot(dquot);
872                 atomic_inc(&dquot->dq_count);
873                 spin_unlock(&dq_list_lock);
874                 dqstats_inc(DQST_CACHE_HITS);
875                 dqstats_inc(DQST_LOOKUPS);
876         }
877         /* Wait for dq_lock - after this we know that either dquot_release() is
878          * already finished or it will be canceled due to dq_count > 1 test */
879         wait_on_dquot(dquot);
880         /* Read the dquot / allocate space in quota file */
881         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) &&
882             sb->dq_op->acquire_dquot(dquot) < 0) {
883                 dqput(dquot);
884                 dquot = NULL;
885                 goto out;
886         }
887 #ifdef CONFIG_QUOTA_DEBUG
888         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
889 #endif
890 out:
891         if (empty)
892                 do_destroy_dquot(empty);
893
894         return dquot;
895 }
896 EXPORT_SYMBOL(dqget);
897
898 static int dqinit_needed(struct inode *inode, int type)
899 {
900         int cnt;
901
902         if (IS_NOQUOTA(inode))
903                 return 0;
904         if (type != -1)
905                 return !inode->i_dquot[type];
906         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
907                 if (!inode->i_dquot[cnt])
908                         return 1;
909         return 0;
910 }
911
912 /* This routine is guarded by dqonoff_mutex mutex */
913 static void add_dquot_ref(struct super_block *sb, int type)
914 {
915         struct inode *inode, *old_inode = NULL;
916 #ifdef CONFIG_QUOTA_DEBUG
917         int reserved = 0;
918 #endif
919
920         spin_lock(&inode_sb_list_lock);
921         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
922                 spin_lock(&inode->i_lock);
923                 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
924                     !atomic_read(&inode->i_writecount) ||
925                     !dqinit_needed(inode, type)) {
926                         spin_unlock(&inode->i_lock);
927                         continue;
928                 }
929                 __iget(inode);
930                 spin_unlock(&inode->i_lock);
931                 spin_unlock(&inode_sb_list_lock);
932
933 #ifdef CONFIG_QUOTA_DEBUG
934                 if (unlikely(inode_get_rsv_space(inode) > 0))
935                         reserved = 1;
936 #endif
937                 iput(old_inode);
938                 __dquot_initialize(inode, type);
939
940                 /*
941                  * We hold a reference to 'inode' so it couldn't have been
942                  * removed from s_inodes list while we dropped the
943                  * inode_sb_list_lock We cannot iput the inode now as we can be
944                  * holding the last reference and we cannot iput it under
945                  * inode_sb_list_lock. So we keep the reference and iput it
946                  * later.
947                  */
948                 old_inode = inode;
949                 spin_lock(&inode_sb_list_lock);
950         }
951         spin_unlock(&inode_sb_list_lock);
952         iput(old_inode);
953
954 #ifdef CONFIG_QUOTA_DEBUG
955         if (reserved) {
956                 quota_error(sb, "Writes happened before quota was turned on "
957                         "thus quota information is probably inconsistent. "
958                         "Please run quotacheck(8)");
959         }
960 #endif
961 }
962
963 /*
964  * Return 0 if dqput() won't block.
965  * (note that 1 doesn't necessarily mean blocking)
966  */
967 static inline int dqput_blocks(struct dquot *dquot)
968 {
969         if (atomic_read(&dquot->dq_count) <= 1)
970                 return 1;
971         return 0;
972 }
973
974 /*
975  * Remove references to dquots from inode and add dquot to list for freeing
976  * if we have the last reference to dquot
977  * We can't race with anybody because we hold dqptr_sem for writing...
978  */
979 static int remove_inode_dquot_ref(struct inode *inode, int type,
980                                   struct list_head *tofree_head)
981 {
982         struct dquot *dquot = inode->i_dquot[type];
983
984         inode->i_dquot[type] = NULL;
985         if (dquot) {
986                 if (dqput_blocks(dquot)) {
987 #ifdef CONFIG_QUOTA_DEBUG
988                         if (atomic_read(&dquot->dq_count) != 1)
989                                 quota_error(inode->i_sb, "Adding dquot with "
990                                             "dq_count %d to dispose list",
991                                             atomic_read(&dquot->dq_count));
992 #endif
993                         spin_lock(&dq_list_lock);
994                         /* As dquot must have currently users it can't be on
995                          * the free list... */
996                         list_add(&dquot->dq_free, tofree_head);
997                         spin_unlock(&dq_list_lock);
998                         return 1;
999                 }
1000                 else
1001                         dqput(dquot);   /* We have guaranteed we won't block */
1002         }
1003         return 0;
1004 }
1005
1006 /*
1007  * Free list of dquots
1008  * Dquots are removed from inodes and no new references can be got so we are
1009  * the only ones holding reference
1010  */
1011 static void put_dquot_list(struct list_head *tofree_head)
1012 {
1013         struct list_head *act_head;
1014         struct dquot *dquot;
1015
1016         act_head = tofree_head->next;
1017         while (act_head != tofree_head) {
1018                 dquot = list_entry(act_head, struct dquot, dq_free);
1019                 act_head = act_head->next;
1020                 /* Remove dquot from the list so we won't have problems... */
1021                 list_del_init(&dquot->dq_free);
1022                 dqput(dquot);
1023         }
1024 }
1025
1026 static void remove_dquot_ref(struct super_block *sb, int type,
1027                 struct list_head *tofree_head)
1028 {
1029         struct inode *inode;
1030         int reserved = 0;
1031
1032         spin_lock(&inode_sb_list_lock);
1033         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
1034                 /*
1035                  *  We have to scan also I_NEW inodes because they can already
1036                  *  have quota pointer initialized. Luckily, we need to touch
1037                  *  only quota pointers and these have separate locking
1038                  *  (dqptr_sem).
1039                  */
1040                 if (!IS_NOQUOTA(inode)) {
1041                         if (unlikely(inode_get_rsv_space(inode) > 0))
1042                                 reserved = 1;
1043                         remove_inode_dquot_ref(inode, type, tofree_head);
1044                 }
1045         }
1046         spin_unlock(&inode_sb_list_lock);
1047 #ifdef CONFIG_QUOTA_DEBUG
1048         if (reserved) {
1049                 printk(KERN_WARNING "VFS (%s): Writes happened after quota"
1050                         " was disabled thus quota information is probably "
1051                         "inconsistent. Please run quotacheck(8).\n", sb->s_id);
1052         }
1053 #endif
1054 }
1055
1056 /* Gather all references from inodes and drop them */
1057 static void drop_dquot_ref(struct super_block *sb, int type)
1058 {
1059         LIST_HEAD(tofree_head);
1060
1061         if (sb->dq_op) {
1062                 down_write(&sb_dqopt(sb)->dqptr_sem);
1063                 remove_dquot_ref(sb, type, &tofree_head);
1064                 up_write(&sb_dqopt(sb)->dqptr_sem);
1065                 put_dquot_list(&tofree_head);
1066         }
1067 }
1068
1069 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
1070 {
1071         dquot->dq_dqb.dqb_curinodes += number;
1072 }
1073
1074 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
1075 {
1076         dquot->dq_dqb.dqb_curspace += number;
1077 }
1078
1079 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
1080 {
1081         dquot->dq_dqb.dqb_rsvspace += number;
1082 }
1083
1084 /*
1085  * Claim reserved quota space
1086  */
1087 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number)
1088 {
1089         if (dquot->dq_dqb.dqb_rsvspace < number) {
1090                 WARN_ON_ONCE(1);
1091                 number = dquot->dq_dqb.dqb_rsvspace;
1092         }
1093         dquot->dq_dqb.dqb_curspace += number;
1094         dquot->dq_dqb.dqb_rsvspace -= number;
1095 }
1096
1097 static inline
1098 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
1099 {
1100         if (dquot->dq_dqb.dqb_rsvspace >= number)
1101                 dquot->dq_dqb.dqb_rsvspace -= number;
1102         else {
1103                 WARN_ON_ONCE(1);
1104                 dquot->dq_dqb.dqb_rsvspace = 0;
1105         }
1106 }
1107
1108 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1109 {
1110         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1111             dquot->dq_dqb.dqb_curinodes >= number)
1112                 dquot->dq_dqb.dqb_curinodes -= number;
1113         else
1114                 dquot->dq_dqb.dqb_curinodes = 0;
1115         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1116                 dquot->dq_dqb.dqb_itime = (time_t) 0;
1117         clear_bit(DQ_INODES_B, &dquot->dq_flags);
1118 }
1119
1120 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1121 {
1122         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1123             dquot->dq_dqb.dqb_curspace >= number)
1124                 dquot->dq_dqb.dqb_curspace -= number;
1125         else
1126                 dquot->dq_dqb.dqb_curspace = 0;
1127         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1128                 dquot->dq_dqb.dqb_btime = (time_t) 0;
1129         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1130 }
1131
1132 struct dquot_warn {
1133         struct super_block *w_sb;
1134         struct kqid w_dq_id;
1135         short w_type;
1136 };
1137
1138 static int warning_issued(struct dquot *dquot, const int warntype)
1139 {
1140         int flag = (warntype == QUOTA_NL_BHARDWARN ||
1141                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1142                 ((warntype == QUOTA_NL_IHARDWARN ||
1143                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1144
1145         if (!flag)
1146                 return 0;
1147         return test_and_set_bit(flag, &dquot->dq_flags);
1148 }
1149
1150 #ifdef CONFIG_PRINT_QUOTA_WARNING
1151 static int flag_print_warnings = 1;
1152
1153 static int need_print_warning(struct dquot_warn *warn)
1154 {
1155         if (!flag_print_warnings)
1156                 return 0;
1157
1158         switch (warn->w_dq_id.type) {
1159                 case USRQUOTA:
1160                         return uid_eq(current_fsuid(), warn->w_dq_id.uid);
1161                 case GRPQUOTA:
1162                         return in_group_p(warn->w_dq_id.gid);
1163                 case PRJQUOTA:  /* Never taken... Just make gcc happy */
1164                         return 0;
1165         }
1166         return 0;
1167 }
1168
1169 /* Print warning to user which exceeded quota */
1170 static void print_warning(struct dquot_warn *warn)
1171 {
1172         char *msg = NULL;
1173         struct tty_struct *tty;
1174         int warntype = warn->w_type;
1175
1176         if (warntype == QUOTA_NL_IHARDBELOW ||
1177             warntype == QUOTA_NL_ISOFTBELOW ||
1178             warntype == QUOTA_NL_BHARDBELOW ||
1179             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn))
1180                 return;
1181
1182         tty = get_current_tty();
1183         if (!tty)
1184                 return;
1185         tty_write_message(tty, warn->w_sb->s_id);
1186         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1187                 tty_write_message(tty, ": warning, ");
1188         else
1189                 tty_write_message(tty, ": write failed, ");
1190         tty_write_message(tty, quotatypes[warn->w_dq_id.type]);
1191         switch (warntype) {
1192                 case QUOTA_NL_IHARDWARN:
1193                         msg = " file limit reached.\r\n";
1194                         break;
1195                 case QUOTA_NL_ISOFTLONGWARN:
1196                         msg = " file quota exceeded too long.\r\n";
1197                         break;
1198                 case QUOTA_NL_ISOFTWARN:
1199                         msg = " file quota exceeded.\r\n";
1200                         break;
1201                 case QUOTA_NL_BHARDWARN:
1202                         msg = " block limit reached.\r\n";
1203                         break;
1204                 case QUOTA_NL_BSOFTLONGWARN:
1205                         msg = " block quota exceeded too long.\r\n";
1206                         break;
1207                 case QUOTA_NL_BSOFTWARN:
1208                         msg = " block quota exceeded.\r\n";
1209                         break;
1210         }
1211         tty_write_message(tty, msg);
1212         tty_kref_put(tty);
1213 }
1214 #endif
1215
1216 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot,
1217                             int warntype)
1218 {
1219         if (warning_issued(dquot, warntype))
1220                 return;
1221         warn->w_type = warntype;
1222         warn->w_sb = dquot->dq_sb;
1223         warn->w_dq_id = dquot->dq_id;
1224 }
1225
1226 /*
1227  * Write warnings to the console and send warning messages over netlink.
1228  *
1229  * Note that this function can call into tty and networking code.
1230  */
1231 static void flush_warnings(struct dquot_warn *warn)
1232 {
1233         int i;
1234
1235         for (i = 0; i < MAXQUOTAS; i++) {
1236                 if (warn[i].w_type == QUOTA_NL_NOWARN)
1237                         continue;
1238 #ifdef CONFIG_PRINT_QUOTA_WARNING
1239                 print_warning(&warn[i]);
1240 #endif
1241                 quota_send_warning(warn[i].w_dq_id,
1242                                    warn[i].w_sb->s_dev, warn[i].w_type);
1243         }
1244 }
1245
1246 static int ignore_hardlimit(struct dquot *dquot)
1247 {
1248         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
1249
1250         return capable(CAP_SYS_RESOURCE) &&
1251                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1252                 !(info->dqi_flags & V1_DQF_RSQUASH));
1253 }
1254
1255 /* needs dq_data_lock */
1256 static int check_idq(struct dquot *dquot, qsize_t inodes,
1257                      struct dquot_warn *warn)
1258 {
1259         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1260
1261         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) ||
1262             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1263                 return 0;
1264
1265         if (dquot->dq_dqb.dqb_ihardlimit &&
1266             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1267             !ignore_hardlimit(dquot)) {
1268                 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN);
1269                 return -EDQUOT;
1270         }
1271
1272         if (dquot->dq_dqb.dqb_isoftlimit &&
1273             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1274             dquot->dq_dqb.dqb_itime &&
1275             get_seconds() >= dquot->dq_dqb.dqb_itime &&
1276             !ignore_hardlimit(dquot)) {
1277                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN);
1278                 return -EDQUOT;
1279         }
1280
1281         if (dquot->dq_dqb.dqb_isoftlimit &&
1282             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1283             dquot->dq_dqb.dqb_itime == 0) {
1284                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN);
1285                 dquot->dq_dqb.dqb_itime = get_seconds() +
1286                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace;
1287         }
1288
1289         return 0;
1290 }
1291
1292 /* needs dq_data_lock */
1293 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc,
1294                      struct dquot_warn *warn)
1295 {
1296         qsize_t tspace;
1297         struct super_block *sb = dquot->dq_sb;
1298
1299         if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) ||
1300             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1301                 return 0;
1302
1303         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1304                 + space;
1305
1306         if (dquot->dq_dqb.dqb_bhardlimit &&
1307             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1308             !ignore_hardlimit(dquot)) {
1309                 if (!prealloc)
1310                         prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN);
1311                 return -EDQUOT;
1312         }
1313
1314         if (dquot->dq_dqb.dqb_bsoftlimit &&
1315             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1316             dquot->dq_dqb.dqb_btime &&
1317             get_seconds() >= dquot->dq_dqb.dqb_btime &&
1318             !ignore_hardlimit(dquot)) {
1319                 if (!prealloc)
1320                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN);
1321                 return -EDQUOT;
1322         }
1323
1324         if (dquot->dq_dqb.dqb_bsoftlimit &&
1325             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1326             dquot->dq_dqb.dqb_btime == 0) {
1327                 if (!prealloc) {
1328                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN);
1329                         dquot->dq_dqb.dqb_btime = get_seconds() +
1330                             sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace;
1331                 }
1332                 else
1333                         /*
1334                          * We don't allow preallocation to exceed softlimit so exceeding will
1335                          * be always printed
1336                          */
1337                         return -EDQUOT;
1338         }
1339
1340         return 0;
1341 }
1342
1343 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1344 {
1345         qsize_t newinodes;
1346
1347         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1348             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1349             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type))
1350                 return QUOTA_NL_NOWARN;
1351
1352         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1353         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1354                 return QUOTA_NL_ISOFTBELOW;
1355         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1356             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1357                 return QUOTA_NL_IHARDBELOW;
1358         return QUOTA_NL_NOWARN;
1359 }
1360
1361 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1362 {
1363         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1364             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1365                 return QUOTA_NL_NOWARN;
1366
1367         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1368                 return QUOTA_NL_BSOFTBELOW;
1369         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1370             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1371                 return QUOTA_NL_BHARDBELOW;
1372         return QUOTA_NL_NOWARN;
1373 }
1374
1375 static int dquot_active(const struct inode *inode)
1376 {
1377         struct super_block *sb = inode->i_sb;
1378
1379         if (IS_NOQUOTA(inode))
1380                 return 0;
1381         return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
1382 }
1383
1384 /*
1385  * Initialize quota pointers in inode
1386  *
1387  * We do things in a bit complicated way but by that we avoid calling
1388  * dqget() and thus filesystem callbacks under dqptr_sem.
1389  *
1390  * It is better to call this function outside of any transaction as it
1391  * might need a lot of space in journal for dquot structure allocation.
1392  */
1393 static void __dquot_initialize(struct inode *inode, int type)
1394 {
1395         int cnt;
1396         struct dquot *got[MAXQUOTAS];
1397         struct super_block *sb = inode->i_sb;
1398         qsize_t rsv;
1399
1400         /* First test before acquiring mutex - solves deadlocks when we
1401          * re-enter the quota code and are already holding the mutex */
1402         if (!dquot_active(inode))
1403                 return;
1404
1405         /* First get references to structures we might need. */
1406         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1407                 struct kqid qid;
1408                 got[cnt] = NULL;
1409                 if (type != -1 && cnt != type)
1410                         continue;
1411                 switch (cnt) {
1412                 case USRQUOTA:
1413                         qid = make_kqid_uid(inode->i_uid);
1414                         break;
1415                 case GRPQUOTA:
1416                         qid = make_kqid_gid(inode->i_gid);
1417                         break;
1418                 }
1419                 got[cnt] = dqget(sb, qid);
1420         }
1421
1422         down_write(&sb_dqopt(sb)->dqptr_sem);
1423         if (IS_NOQUOTA(inode))
1424                 goto out_err;
1425         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1426                 if (type != -1 && cnt != type)
1427                         continue;
1428                 /* Avoid races with quotaoff() */
1429                 if (!sb_has_quota_active(sb, cnt))
1430                         continue;
1431                 /* We could race with quotaon or dqget() could have failed */
1432                 if (!got[cnt])
1433                         continue;
1434                 if (!inode->i_dquot[cnt]) {
1435                         inode->i_dquot[cnt] = got[cnt];
1436                         got[cnt] = NULL;
1437                         /*
1438                          * Make quota reservation system happy if someone
1439                          * did a write before quota was turned on
1440                          */
1441                         rsv = inode_get_rsv_space(inode);
1442                         if (unlikely(rsv)) {
1443                                 spin_lock(&dq_data_lock);
1444                                 dquot_resv_space(inode->i_dquot[cnt], rsv);
1445                                 spin_unlock(&dq_data_lock);
1446                         }
1447                 }
1448         }
1449 out_err:
1450         up_write(&sb_dqopt(sb)->dqptr_sem);
1451         /* Drop unused references */
1452         dqput_all(got);
1453 }
1454
1455 void dquot_initialize(struct inode *inode)
1456 {
1457         __dquot_initialize(inode, -1);
1458 }
1459 EXPORT_SYMBOL(dquot_initialize);
1460
1461 /*
1462  *      Release all quotas referenced by inode
1463  */
1464 static void __dquot_drop(struct inode *inode)
1465 {
1466         int cnt;
1467         struct dquot *put[MAXQUOTAS];
1468
1469         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1470         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1471                 put[cnt] = inode->i_dquot[cnt];
1472                 inode->i_dquot[cnt] = NULL;
1473         }
1474         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1475         dqput_all(put);
1476 }
1477
1478 void dquot_drop(struct inode *inode)
1479 {
1480         int cnt;
1481
1482         if (IS_NOQUOTA(inode))
1483                 return;
1484
1485         /*
1486          * Test before calling to rule out calls from proc and such
1487          * where we are not allowed to block. Note that this is
1488          * actually reliable test even without the lock - the caller
1489          * must assure that nobody can come after the DQUOT_DROP and
1490          * add quota pointers back anyway.
1491          */
1492         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1493                 if (inode->i_dquot[cnt])
1494                         break;
1495         }
1496
1497         if (cnt < MAXQUOTAS)
1498                 __dquot_drop(inode);
1499 }
1500 EXPORT_SYMBOL(dquot_drop);
1501
1502 /*
1503  * inode_reserved_space is managed internally by quota, and protected by
1504  * i_lock similar to i_blocks+i_bytes.
1505  */
1506 static qsize_t *inode_reserved_space(struct inode * inode)
1507 {
1508         /* Filesystem must explicitly define it's own method in order to use
1509          * quota reservation interface */
1510         BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1511         return inode->i_sb->dq_op->get_reserved_space(inode);
1512 }
1513
1514 void inode_add_rsv_space(struct inode *inode, qsize_t number)
1515 {
1516         spin_lock(&inode->i_lock);
1517         *inode_reserved_space(inode) += number;
1518         spin_unlock(&inode->i_lock);
1519 }
1520 EXPORT_SYMBOL(inode_add_rsv_space);
1521
1522 void inode_claim_rsv_space(struct inode *inode, qsize_t number)
1523 {
1524         spin_lock(&inode->i_lock);
1525         *inode_reserved_space(inode) -= number;
1526         __inode_add_bytes(inode, number);
1527         spin_unlock(&inode->i_lock);
1528 }
1529 EXPORT_SYMBOL(inode_claim_rsv_space);
1530
1531 void inode_sub_rsv_space(struct inode *inode, qsize_t number)
1532 {
1533         spin_lock(&inode->i_lock);
1534         *inode_reserved_space(inode) -= number;
1535         spin_unlock(&inode->i_lock);
1536 }
1537 EXPORT_SYMBOL(inode_sub_rsv_space);
1538
1539 static qsize_t inode_get_rsv_space(struct inode *inode)
1540 {
1541         qsize_t ret;
1542
1543         if (!inode->i_sb->dq_op->get_reserved_space)
1544                 return 0;
1545         spin_lock(&inode->i_lock);
1546         ret = *inode_reserved_space(inode);
1547         spin_unlock(&inode->i_lock);
1548         return ret;
1549 }
1550
1551 static void inode_incr_space(struct inode *inode, qsize_t number,
1552                                 int reserve)
1553 {
1554         if (reserve)
1555                 inode_add_rsv_space(inode, number);
1556         else
1557                 inode_add_bytes(inode, number);
1558 }
1559
1560 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve)
1561 {
1562         if (reserve)
1563                 inode_sub_rsv_space(inode, number);
1564         else
1565                 inode_sub_bytes(inode, number);
1566 }
1567
1568 /*
1569  * This functions updates i_blocks+i_bytes fields and quota information
1570  * (together with appropriate checks).
1571  *
1572  * NOTE: We absolutely rely on the fact that caller dirties the inode
1573  * (usually helpers in quotaops.h care about this) and holds a handle for
1574  * the current transaction so that dquot write and inode write go into the
1575  * same transaction.
1576  */
1577
1578 /*
1579  * This operation can block, but only after everything is updated
1580  */
1581 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
1582 {
1583         int cnt, ret = 0;
1584         struct dquot_warn warn[MAXQUOTAS];
1585         struct dquot **dquots = inode->i_dquot;
1586         int reserve = flags & DQUOT_SPACE_RESERVE;
1587
1588         /*
1589          * First test before acquiring mutex - solves deadlocks when we
1590          * re-enter the quota code and are already holding the mutex
1591          */
1592         if (!dquot_active(inode)) {
1593                 inode_incr_space(inode, number, reserve);
1594                 goto out;
1595         }
1596
1597         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1598                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1599
1600         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1601         spin_lock(&dq_data_lock);
1602         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1603                 if (!dquots[cnt])
1604                         continue;
1605                 ret = check_bdq(dquots[cnt], number,
1606                                 !(flags & DQUOT_SPACE_WARN), &warn[cnt]);
1607                 if (ret && !(flags & DQUOT_SPACE_NOFAIL)) {
1608                         spin_unlock(&dq_data_lock);
1609                         goto out_flush_warn;
1610                 }
1611         }
1612         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1613                 if (!dquots[cnt])
1614                         continue;
1615                 if (reserve)
1616                         dquot_resv_space(dquots[cnt], number);
1617                 else
1618                         dquot_incr_space(dquots[cnt], number);
1619         }
1620         inode_incr_space(inode, number, reserve);
1621         spin_unlock(&dq_data_lock);
1622
1623         if (reserve)
1624                 goto out_flush_warn;
1625         mark_all_dquot_dirty(dquots);
1626 out_flush_warn:
1627         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1628         flush_warnings(warn);
1629 out:
1630         return ret;
1631 }
1632 EXPORT_SYMBOL(__dquot_alloc_space);
1633
1634 /*
1635  * This operation can block, but only after everything is updated
1636  */
1637 int dquot_alloc_inode(const struct inode *inode)
1638 {
1639         int cnt, ret = 0;
1640         struct dquot_warn warn[MAXQUOTAS];
1641         struct dquot * const *dquots = inode->i_dquot;
1642
1643         /* First test before acquiring mutex - solves deadlocks when we
1644          * re-enter the quota code and are already holding the mutex */
1645         if (!dquot_active(inode))
1646                 return 0;
1647         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1648                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1649         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1650         spin_lock(&dq_data_lock);
1651         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1652                 if (!dquots[cnt])
1653                         continue;
1654                 ret = check_idq(dquots[cnt], 1, &warn[cnt]);
1655                 if (ret)
1656                         goto warn_put_all;
1657         }
1658
1659         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1660                 if (!dquots[cnt])
1661                         continue;
1662                 dquot_incr_inodes(dquots[cnt], 1);
1663         }
1664
1665 warn_put_all:
1666         spin_unlock(&dq_data_lock);
1667         if (ret == 0)
1668                 mark_all_dquot_dirty(dquots);
1669         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1670         flush_warnings(warn);
1671         return ret;
1672 }
1673 EXPORT_SYMBOL(dquot_alloc_inode);
1674
1675 /*
1676  * Convert in-memory reserved quotas to real consumed quotas
1677  */
1678 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
1679 {
1680         int cnt;
1681
1682         if (!dquot_active(inode)) {
1683                 inode_claim_rsv_space(inode, number);
1684                 return 0;
1685         }
1686
1687         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1688         spin_lock(&dq_data_lock);
1689         /* Claim reserved quotas to allocated quotas */
1690         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1691                 if (inode->i_dquot[cnt])
1692                         dquot_claim_reserved_space(inode->i_dquot[cnt],
1693                                                         number);
1694         }
1695         /* Update inode bytes */
1696         inode_claim_rsv_space(inode, number);
1697         spin_unlock(&dq_data_lock);
1698         mark_all_dquot_dirty(inode->i_dquot);
1699         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1700         return 0;
1701 }
1702 EXPORT_SYMBOL(dquot_claim_space_nodirty);
1703
1704 /*
1705  * This operation can block, but only after everything is updated
1706  */
1707 void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
1708 {
1709         unsigned int cnt;
1710         struct dquot_warn warn[MAXQUOTAS];
1711         struct dquot **dquots = inode->i_dquot;
1712         int reserve = flags & DQUOT_SPACE_RESERVE;
1713
1714         /* First test before acquiring mutex - solves deadlocks when we
1715          * re-enter the quota code and are already holding the mutex */
1716         if (!dquot_active(inode)) {
1717                 inode_decr_space(inode, number, reserve);
1718                 return;
1719         }
1720
1721         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1722         spin_lock(&dq_data_lock);
1723         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1724                 int wtype;
1725
1726                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1727                 if (!dquots[cnt])
1728                         continue;
1729                 wtype = info_bdq_free(dquots[cnt], number);
1730                 if (wtype != QUOTA_NL_NOWARN)
1731                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1732                 if (reserve)
1733                         dquot_free_reserved_space(dquots[cnt], number);
1734                 else
1735                         dquot_decr_space(dquots[cnt], number);
1736         }
1737         inode_decr_space(inode, number, reserve);
1738         spin_unlock(&dq_data_lock);
1739
1740         if (reserve)
1741                 goto out_unlock;
1742         mark_all_dquot_dirty(dquots);
1743 out_unlock:
1744         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1745         flush_warnings(warn);
1746 }
1747 EXPORT_SYMBOL(__dquot_free_space);
1748
1749 /*
1750  * This operation can block, but only after everything is updated
1751  */
1752 void dquot_free_inode(const struct inode *inode)
1753 {
1754         unsigned int cnt;
1755         struct dquot_warn warn[MAXQUOTAS];
1756         struct dquot * const *dquots = inode->i_dquot;
1757
1758         /* First test before acquiring mutex - solves deadlocks when we
1759          * re-enter the quota code and are already holding the mutex */
1760         if (!dquot_active(inode))
1761                 return;
1762
1763         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1764         spin_lock(&dq_data_lock);
1765         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1766                 int wtype;
1767
1768                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1769                 if (!dquots[cnt])
1770                         continue;
1771                 wtype = info_idq_free(dquots[cnt], 1);
1772                 if (wtype != QUOTA_NL_NOWARN)
1773                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1774                 dquot_decr_inodes(dquots[cnt], 1);
1775         }
1776         spin_unlock(&dq_data_lock);
1777         mark_all_dquot_dirty(dquots);
1778         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1779         flush_warnings(warn);
1780 }
1781 EXPORT_SYMBOL(dquot_free_inode);
1782
1783 /*
1784  * Transfer the number of inode and blocks from one diskquota to an other.
1785  * On success, dquot references in transfer_to are consumed and references
1786  * to original dquots that need to be released are placed there. On failure,
1787  * references are kept untouched.
1788  *
1789  * This operation can block, but only after everything is updated
1790  * A transaction must be started when entering this function.
1791  *
1792  */
1793 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
1794 {
1795         qsize_t space, cur_space;
1796         qsize_t rsv_space = 0;
1797         struct dquot *transfer_from[MAXQUOTAS] = {};
1798         int cnt, ret = 0;
1799         char is_valid[MAXQUOTAS] = {};
1800         struct dquot_warn warn_to[MAXQUOTAS];
1801         struct dquot_warn warn_from_inodes[MAXQUOTAS];
1802         struct dquot_warn warn_from_space[MAXQUOTAS];
1803
1804         /* First test before acquiring mutex - solves deadlocks when we
1805          * re-enter the quota code and are already holding the mutex */
1806         if (IS_NOQUOTA(inode))
1807                 return 0;
1808         /* Initialize the arrays */
1809         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1810                 warn_to[cnt].w_type = QUOTA_NL_NOWARN;
1811                 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN;
1812                 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN;
1813         }
1814         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1815         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1816                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1817                 return 0;
1818         }
1819         spin_lock(&dq_data_lock);
1820         cur_space = inode_get_bytes(inode);
1821         rsv_space = inode_get_rsv_space(inode);
1822         space = cur_space + rsv_space;
1823         /* Build the transfer_from list and check the limits */
1824         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1825                 /*
1826                  * Skip changes for same uid or gid or for turned off quota-type.
1827                  */
1828                 if (!transfer_to[cnt])
1829                         continue;
1830                 /* Avoid races with quotaoff() */
1831                 if (!sb_has_quota_active(inode->i_sb, cnt))
1832                         continue;
1833                 is_valid[cnt] = 1;
1834                 transfer_from[cnt] = inode->i_dquot[cnt];
1835                 ret = check_idq(transfer_to[cnt], 1, &warn_to[cnt]);
1836                 if (ret)
1837                         goto over_quota;
1838                 ret = check_bdq(transfer_to[cnt], space, 0, &warn_to[cnt]);
1839                 if (ret)
1840                         goto over_quota;
1841         }
1842
1843         /*
1844          * Finally perform the needed transfer from transfer_from to transfer_to
1845          */
1846         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1847                 if (!is_valid[cnt])
1848                         continue;
1849                 /* Due to IO error we might not have transfer_from[] structure */
1850                 if (transfer_from[cnt]) {
1851                         int wtype;
1852                         wtype = info_idq_free(transfer_from[cnt], 1);
1853                         if (wtype != QUOTA_NL_NOWARN)
1854                                 prepare_warning(&warn_from_inodes[cnt],
1855                                                 transfer_from[cnt], wtype);
1856                         wtype = info_bdq_free(transfer_from[cnt], space);
1857                         if (wtype != QUOTA_NL_NOWARN)
1858                                 prepare_warning(&warn_from_space[cnt],
1859                                                 transfer_from[cnt], wtype);
1860                         dquot_decr_inodes(transfer_from[cnt], 1);
1861                         dquot_decr_space(transfer_from[cnt], cur_space);
1862                         dquot_free_reserved_space(transfer_from[cnt],
1863                                                   rsv_space);
1864                 }
1865
1866                 dquot_incr_inodes(transfer_to[cnt], 1);
1867                 dquot_incr_space(transfer_to[cnt], cur_space);
1868                 dquot_resv_space(transfer_to[cnt], rsv_space);
1869
1870                 inode->i_dquot[cnt] = transfer_to[cnt];
1871         }
1872         spin_unlock(&dq_data_lock);
1873         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1874
1875         mark_all_dquot_dirty(transfer_from);
1876         mark_all_dquot_dirty(transfer_to);
1877         flush_warnings(warn_to);
1878         flush_warnings(warn_from_inodes);
1879         flush_warnings(warn_from_space);
1880         /* Pass back references to put */
1881         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1882                 if (is_valid[cnt])
1883                         transfer_to[cnt] = transfer_from[cnt];
1884         return 0;
1885 over_quota:
1886         spin_unlock(&dq_data_lock);
1887         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1888         flush_warnings(warn_to);
1889         return ret;
1890 }
1891 EXPORT_SYMBOL(__dquot_transfer);
1892
1893 /* Wrapper for transferring ownership of an inode for uid/gid only
1894  * Called from FSXXX_setattr()
1895  */
1896 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1897 {
1898         struct dquot *transfer_to[MAXQUOTAS] = {};
1899         struct super_block *sb = inode->i_sb;
1900         int ret;
1901
1902         if (!dquot_active(inode))
1903                 return 0;
1904
1905         if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid))
1906                 transfer_to[USRQUOTA] = dqget(sb, make_kqid_uid(iattr->ia_uid));
1907         if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))
1908                 transfer_to[GRPQUOTA] = dqget(sb, make_kqid_gid(iattr->ia_gid));
1909
1910         ret = __dquot_transfer(inode, transfer_to);
1911         dqput_all(transfer_to);
1912         return ret;
1913 }
1914 EXPORT_SYMBOL(dquot_transfer);
1915
1916 /*
1917  * Write info of quota file to disk
1918  */
1919 int dquot_commit_info(struct super_block *sb, int type)
1920 {
1921         int ret;
1922         struct quota_info *dqopt = sb_dqopt(sb);
1923
1924         mutex_lock(&dqopt->dqio_mutex);
1925         ret = dqopt->ops[type]->write_file_info(sb, type);
1926         mutex_unlock(&dqopt->dqio_mutex);
1927         return ret;
1928 }
1929 EXPORT_SYMBOL(dquot_commit_info);
1930
1931 /*
1932  * Definitions of diskquota operations.
1933  */
1934 const struct dquot_operations dquot_operations = {
1935         .write_dquot    = dquot_commit,
1936         .acquire_dquot  = dquot_acquire,
1937         .release_dquot  = dquot_release,
1938         .mark_dirty     = dquot_mark_dquot_dirty,
1939         .write_info     = dquot_commit_info,
1940         .alloc_dquot    = dquot_alloc,
1941         .destroy_dquot  = dquot_destroy,
1942 };
1943 EXPORT_SYMBOL(dquot_operations);
1944
1945 /*
1946  * Generic helper for ->open on filesystems supporting disk quotas.
1947  */
1948 int dquot_file_open(struct inode *inode, struct file *file)
1949 {
1950         int error;
1951
1952         error = generic_file_open(inode, file);
1953         if (!error && (file->f_mode & FMODE_WRITE))
1954                 dquot_initialize(inode);
1955         return error;
1956 }
1957 EXPORT_SYMBOL(dquot_file_open);
1958
1959 /*
1960  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1961  */
1962 int dquot_disable(struct super_block *sb, int type, unsigned int flags)
1963 {
1964         int cnt, ret = 0;
1965         struct quota_info *dqopt = sb_dqopt(sb);
1966         struct inode *toputinode[MAXQUOTAS];
1967
1968         /* Cannot turn off usage accounting without turning off limits, or
1969          * suspend quotas and simultaneously turn quotas off. */
1970         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1971             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1972             DQUOT_USAGE_ENABLED)))
1973                 return -EINVAL;
1974
1975         /* We need to serialize quota_off() for device */
1976         mutex_lock(&dqopt->dqonoff_mutex);
1977
1978         /*
1979          * Skip everything if there's nothing to do. We have to do this because
1980          * sometimes we are called when fill_super() failed and calling
1981          * sync_fs() in such cases does no good.
1982          */
1983         if (!sb_any_quota_loaded(sb)) {
1984                 mutex_unlock(&dqopt->dqonoff_mutex);
1985                 return 0;
1986         }
1987         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1988                 toputinode[cnt] = NULL;
1989                 if (type != -1 && cnt != type)
1990                         continue;
1991                 if (!sb_has_quota_loaded(sb, cnt))
1992                         continue;
1993
1994                 if (flags & DQUOT_SUSPENDED) {
1995                         spin_lock(&dq_state_lock);
1996                         dqopt->flags |=
1997                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1998                         spin_unlock(&dq_state_lock);
1999                 } else {
2000                         spin_lock(&dq_state_lock);
2001                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
2002                         /* Turning off suspended quotas? */
2003                         if (!sb_has_quota_loaded(sb, cnt) &&
2004                             sb_has_quota_suspended(sb, cnt)) {
2005                                 dqopt->flags &= ~dquot_state_flag(
2006                                                         DQUOT_SUSPENDED, cnt);
2007                                 spin_unlock(&dq_state_lock);
2008                                 iput(dqopt->files[cnt]);
2009                                 dqopt->files[cnt] = NULL;
2010                                 continue;
2011                         }
2012                         spin_unlock(&dq_state_lock);
2013                 }
2014
2015                 /* We still have to keep quota loaded? */
2016                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
2017                         continue;
2018
2019                 /* Note: these are blocking operations */
2020                 drop_dquot_ref(sb, cnt);
2021                 invalidate_dquots(sb, cnt);
2022                 /*
2023                  * Now all dquots should be invalidated, all writes done so we
2024                  * should be only users of the info. No locks needed.
2025                  */
2026                 if (info_dirty(&dqopt->info[cnt]))
2027                         sb->dq_op->write_info(sb, cnt);
2028                 if (dqopt->ops[cnt]->free_file_info)
2029                         dqopt->ops[cnt]->free_file_info(sb, cnt);
2030                 put_quota_format(dqopt->info[cnt].dqi_format);
2031
2032                 toputinode[cnt] = dqopt->files[cnt];
2033                 if (!sb_has_quota_loaded(sb, cnt))
2034                         dqopt->files[cnt] = NULL;
2035                 dqopt->info[cnt].dqi_flags = 0;
2036                 dqopt->info[cnt].dqi_igrace = 0;
2037                 dqopt->info[cnt].dqi_bgrace = 0;
2038                 dqopt->ops[cnt] = NULL;
2039         }
2040         mutex_unlock(&dqopt->dqonoff_mutex);
2041
2042         /* Skip syncing and setting flags if quota files are hidden */
2043         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
2044                 goto put_inodes;
2045
2046         /* Sync the superblock so that buffers with quota data are written to
2047          * disk (and so userspace sees correct data afterwards). */
2048         if (sb->s_op->sync_fs)
2049                 sb->s_op->sync_fs(sb, 1);
2050         sync_blockdev(sb->s_bdev);
2051         /* Now the quota files are just ordinary files and we can set the
2052          * inode flags back. Moreover we discard the pagecache so that
2053          * userspace sees the writes we did bypassing the pagecache. We
2054          * must also discard the blockdev buffers so that we see the
2055          * changes done by userspace on the next quotaon() */
2056         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2057                 if (toputinode[cnt]) {
2058                         mutex_lock(&dqopt->dqonoff_mutex);
2059                         /* If quota was reenabled in the meantime, we have
2060                          * nothing to do */
2061                         if (!sb_has_quota_loaded(sb, cnt)) {
2062                                 mutex_lock(&toputinode[cnt]->i_mutex);
2063                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
2064                                   S_NOATIME | S_NOQUOTA);
2065                                 truncate_inode_pages(&toputinode[cnt]->i_data,
2066                                                      0);
2067                                 mutex_unlock(&toputinode[cnt]->i_mutex);
2068                                 mark_inode_dirty_sync(toputinode[cnt]);
2069                         }
2070                         mutex_unlock(&dqopt->dqonoff_mutex);
2071                 }
2072         if (sb->s_bdev)
2073                 invalidate_bdev(sb->s_bdev);
2074 put_inodes:
2075         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2076                 if (toputinode[cnt]) {
2077                         /* On remount RO, we keep the inode pointer so that we
2078                          * can reenable quota on the subsequent remount RW. We
2079                          * have to check 'flags' variable and not use sb_has_
2080                          * function because another quotaon / quotaoff could
2081                          * change global state before we got here. We refuse
2082                          * to suspend quotas when there is pending delete on
2083                          * the quota file... */
2084                         if (!(flags & DQUOT_SUSPENDED))
2085                                 iput(toputinode[cnt]);
2086                         else if (!toputinode[cnt]->i_nlink)
2087                                 ret = -EBUSY;
2088                 }
2089         return ret;
2090 }
2091 EXPORT_SYMBOL(dquot_disable);
2092
2093 int dquot_quota_off(struct super_block *sb, int type)
2094 {
2095         return dquot_disable(sb, type,
2096                              DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2097 }
2098 EXPORT_SYMBOL(dquot_quota_off);
2099
2100 /*
2101  *      Turn quotas on on a device
2102  */
2103
2104 /*
2105  * Helper function to turn quotas on when we already have the inode of
2106  * quota file and no quota information is loaded.
2107  */
2108 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2109         unsigned int flags)
2110 {
2111         struct quota_format_type *fmt = find_quota_format(format_id);
2112         struct super_block *sb = inode->i_sb;
2113         struct quota_info *dqopt = sb_dqopt(sb);
2114         int error;
2115         int oldflags = -1;
2116
2117         if (!fmt)
2118                 return -ESRCH;
2119         if (!S_ISREG(inode->i_mode)) {
2120                 error = -EACCES;
2121                 goto out_fmt;
2122         }
2123         if (IS_RDONLY(inode)) {
2124                 error = -EROFS;
2125                 goto out_fmt;
2126         }
2127         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
2128                 error = -EINVAL;
2129                 goto out_fmt;
2130         }
2131         /* Usage always has to be set... */
2132         if (!(flags & DQUOT_USAGE_ENABLED)) {
2133                 error = -EINVAL;
2134                 goto out_fmt;
2135         }
2136
2137         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2138                 /* As we bypass the pagecache we must now flush all the
2139                  * dirty data and invalidate caches so that kernel sees
2140                  * changes from userspace. It is not enough to just flush
2141                  * the quota file since if blocksize < pagesize, invalidation
2142                  * of the cache could fail because of other unrelated dirty
2143                  * data */
2144                 sync_filesystem(sb);
2145                 invalidate_bdev(sb->s_bdev);
2146         }
2147         mutex_lock(&dqopt->dqonoff_mutex);
2148         if (sb_has_quota_loaded(sb, type)) {
2149                 error = -EBUSY;
2150                 goto out_lock;
2151         }
2152
2153         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2154                 /* We don't want quota and atime on quota files (deadlocks
2155                  * possible) Also nobody should write to the file - we use
2156                  * special IO operations which ignore the immutable bit. */
2157                 mutex_lock(&inode->i_mutex);
2158                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2159                                              S_NOQUOTA);
2160                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2161                 mutex_unlock(&inode->i_mutex);
2162                 /*
2163                  * When S_NOQUOTA is set, remove dquot references as no more
2164                  * references can be added
2165                  */
2166                 __dquot_drop(inode);
2167         }
2168
2169         error = -EIO;
2170         dqopt->files[type] = igrab(inode);
2171         if (!dqopt->files[type])
2172                 goto out_lock;
2173         error = -EINVAL;
2174         if (!fmt->qf_ops->check_quota_file(sb, type))
2175                 goto out_file_init;
2176
2177         dqopt->ops[type] = fmt->qf_ops;
2178         dqopt->info[type].dqi_format = fmt;
2179         dqopt->info[type].dqi_fmt_id = format_id;
2180         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2181         mutex_lock(&dqopt->dqio_mutex);
2182         error = dqopt->ops[type]->read_file_info(sb, type);
2183         if (error < 0) {
2184                 mutex_unlock(&dqopt->dqio_mutex);
2185                 goto out_file_init;
2186         }
2187         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
2188                 dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
2189         mutex_unlock(&dqopt->dqio_mutex);
2190         spin_lock(&dq_state_lock);
2191         dqopt->flags |= dquot_state_flag(flags, type);
2192         spin_unlock(&dq_state_lock);
2193
2194         add_dquot_ref(sb, type);
2195         mutex_unlock(&dqopt->dqonoff_mutex);
2196
2197         return 0;
2198
2199 out_file_init:
2200         dqopt->files[type] = NULL;
2201         iput(inode);
2202 out_lock:
2203         if (oldflags != -1) {
2204                 mutex_lock(&inode->i_mutex);
2205                 /* Set the flags back (in the case of accidental quotaon()
2206                  * on a wrong file we don't want to mess up the flags) */
2207                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2208                 inode->i_flags |= oldflags;
2209                 mutex_unlock(&inode->i_mutex);
2210         }
2211         mutex_unlock(&dqopt->dqonoff_mutex);
2212 out_fmt:
2213         put_quota_format(fmt);
2214
2215         return error; 
2216 }
2217
2218 /* Reenable quotas on remount RW */
2219 int dquot_resume(struct super_block *sb, int type)
2220 {
2221         struct quota_info *dqopt = sb_dqopt(sb);
2222         struct inode *inode;
2223         int ret = 0, cnt;
2224         unsigned int flags;
2225
2226         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2227                 if (type != -1 && cnt != type)
2228                         continue;
2229
2230                 mutex_lock(&dqopt->dqonoff_mutex);
2231                 if (!sb_has_quota_suspended(sb, cnt)) {
2232                         mutex_unlock(&dqopt->dqonoff_mutex);
2233                         continue;
2234                 }
2235                 inode = dqopt->files[cnt];
2236                 dqopt->files[cnt] = NULL;
2237                 spin_lock(&dq_state_lock);
2238                 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2239                                                         DQUOT_LIMITS_ENABLED,
2240                                                         cnt);
2241                 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
2242                 spin_unlock(&dq_state_lock);
2243                 mutex_unlock(&dqopt->dqonoff_mutex);
2244
2245                 flags = dquot_generic_flag(flags, cnt);
2246                 ret = vfs_load_quota_inode(inode, cnt,
2247                                 dqopt->info[cnt].dqi_fmt_id, flags);
2248                 iput(inode);
2249         }
2250
2251         return ret;
2252 }
2253 EXPORT_SYMBOL(dquot_resume);
2254
2255 int dquot_quota_on(struct super_block *sb, int type, int format_id,
2256                    struct path *path)
2257 {
2258         int error = security_quota_on(path->dentry);
2259         if (error)
2260                 return error;
2261         /* Quota file not on the same filesystem? */
2262         if (path->dentry->d_sb != sb)
2263                 error = -EXDEV;
2264         else
2265                 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2266                                              format_id, DQUOT_USAGE_ENABLED |
2267                                              DQUOT_LIMITS_ENABLED);
2268         return error;
2269 }
2270 EXPORT_SYMBOL(dquot_quota_on);
2271
2272 /*
2273  * More powerful function for turning on quotas allowing setting
2274  * of individual quota flags
2275  */
2276 int dquot_enable(struct inode *inode, int type, int format_id,
2277                  unsigned int flags)
2278 {
2279         int ret = 0;
2280         struct super_block *sb = inode->i_sb;
2281         struct quota_info *dqopt = sb_dqopt(sb);
2282
2283         /* Just unsuspend quotas? */
2284         BUG_ON(flags & DQUOT_SUSPENDED);
2285
2286         if (!flags)
2287                 return 0;
2288         /* Just updating flags needed? */
2289         if (sb_has_quota_loaded(sb, type)) {
2290                 mutex_lock(&dqopt->dqonoff_mutex);
2291                 /* Now do a reliable test... */
2292                 if (!sb_has_quota_loaded(sb, type)) {
2293                         mutex_unlock(&dqopt->dqonoff_mutex);
2294                         goto load_quota;
2295                 }
2296                 if (flags & DQUOT_USAGE_ENABLED &&
2297                     sb_has_quota_usage_enabled(sb, type)) {
2298                         ret = -EBUSY;
2299                         goto out_lock;
2300                 }
2301                 if (flags & DQUOT_LIMITS_ENABLED &&
2302                     sb_has_quota_limits_enabled(sb, type)) {
2303                         ret = -EBUSY;
2304                         goto out_lock;
2305                 }
2306                 spin_lock(&dq_state_lock);
2307                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2308                 spin_unlock(&dq_state_lock);
2309 out_lock:
2310                 mutex_unlock(&dqopt->dqonoff_mutex);
2311                 return ret;
2312         }
2313
2314 load_quota:
2315         return vfs_load_quota_inode(inode, type, format_id, flags);
2316 }
2317 EXPORT_SYMBOL(dquot_enable);
2318
2319 /*
2320  * This function is used when filesystem needs to initialize quotas
2321  * during mount time.
2322  */
2323 int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
2324                 int format_id, int type)
2325 {
2326         struct dentry *dentry;
2327         int error;
2328
2329         mutex_lock(&sb->s_root->d_inode->i_mutex);
2330         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2331         mutex_unlock(&sb->s_root->d_inode->i_mutex);
2332         if (IS_ERR(dentry))
2333                 return PTR_ERR(dentry);
2334
2335         if (!dentry->d_inode) {
2336                 error = -ENOENT;
2337                 goto out;
2338         }
2339
2340         error = security_quota_on(dentry);
2341         if (!error)
2342                 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2343                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2344
2345 out:
2346         dput(dentry);
2347         return error;
2348 }
2349 EXPORT_SYMBOL(dquot_quota_on_mount);
2350
2351 static inline qsize_t qbtos(qsize_t blocks)
2352 {
2353         return blocks << QIF_DQBLKSIZE_BITS;
2354 }
2355
2356 static inline qsize_t stoqb(qsize_t space)
2357 {
2358         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2359 }
2360
2361 /* Generic routine for getting common part of quota structure */
2362 static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
2363 {
2364         struct mem_dqblk *dm = &dquot->dq_dqb;
2365
2366         memset(di, 0, sizeof(*di));
2367         di->d_version = FS_DQUOT_VERSION;
2368         di->d_flags = dquot->dq_id.type == USRQUOTA ?
2369                         FS_USER_QUOTA : FS_GROUP_QUOTA;
2370         di->d_id = from_kqid_munged(current_user_ns(), dquot->dq_id);
2371
2372         spin_lock(&dq_data_lock);
2373         di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit);
2374         di->d_blk_softlimit = stoqb(dm->dqb_bsoftlimit);
2375         di->d_ino_hardlimit = dm->dqb_ihardlimit;
2376         di->d_ino_softlimit = dm->dqb_isoftlimit;
2377         di->d_bcount = dm->dqb_curspace + dm->dqb_rsvspace;
2378         di->d_icount = dm->dqb_curinodes;
2379         di->d_btimer = dm->dqb_btime;
2380         di->d_itimer = dm->dqb_itime;
2381         spin_unlock(&dq_data_lock);
2382 }
2383
2384 int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
2385                     struct fs_disk_quota *di)
2386 {
2387         struct dquot *dquot;
2388
2389         dquot = dqget(sb, qid);
2390         if (!dquot)
2391                 return -ESRCH;
2392         do_get_dqblk(dquot, di);
2393         dqput(dquot);
2394
2395         return 0;
2396 }
2397 EXPORT_SYMBOL(dquot_get_dqblk);
2398
2399 #define VFS_FS_DQ_MASK \
2400         (FS_DQ_BCOUNT | FS_DQ_BSOFT | FS_DQ_BHARD | \
2401          FS_DQ_ICOUNT | FS_DQ_ISOFT | FS_DQ_IHARD | \
2402          FS_DQ_BTIMER | FS_DQ_ITIMER)
2403
2404 /* Generic routine for setting common part of quota structure */
2405 static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
2406 {
2407         struct mem_dqblk *dm = &dquot->dq_dqb;
2408         int check_blim = 0, check_ilim = 0;
2409         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
2410
2411         if (di->d_fieldmask & ~VFS_FS_DQ_MASK)
2412                 return -EINVAL;
2413
2414         if (((di->d_fieldmask & FS_DQ_BSOFT) &&
2415              (di->d_blk_softlimit > dqi->dqi_maxblimit)) ||
2416             ((di->d_fieldmask & FS_DQ_BHARD) &&
2417              (di->d_blk_hardlimit > dqi->dqi_maxblimit)) ||
2418             ((di->d_fieldmask & FS_DQ_ISOFT) &&
2419              (di->d_ino_softlimit > dqi->dqi_maxilimit)) ||
2420             ((di->d_fieldmask & FS_DQ_IHARD) &&
2421              (di->d_ino_hardlimit > dqi->dqi_maxilimit)))
2422                 return -ERANGE;
2423
2424         spin_lock(&dq_data_lock);
2425         if (di->d_fieldmask & FS_DQ_BCOUNT) {
2426                 dm->dqb_curspace = di->d_bcount - dm->dqb_rsvspace;
2427                 check_blim = 1;
2428                 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2429         }
2430
2431         if (di->d_fieldmask & FS_DQ_BSOFT)
2432                 dm->dqb_bsoftlimit = qbtos(di->d_blk_softlimit);
2433         if (di->d_fieldmask & FS_DQ_BHARD)
2434                 dm->dqb_bhardlimit = qbtos(di->d_blk_hardlimit);
2435         if (di->d_fieldmask & (FS_DQ_BSOFT | FS_DQ_BHARD)) {
2436                 check_blim = 1;
2437                 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2438         }
2439
2440         if (di->d_fieldmask & FS_DQ_ICOUNT) {
2441                 dm->dqb_curinodes = di->d_icount;
2442                 check_ilim = 1;
2443                 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2444         }
2445
2446         if (di->d_fieldmask & FS_DQ_ISOFT)
2447                 dm->dqb_isoftlimit = di->d_ino_softlimit;
2448         if (di->d_fieldmask & FS_DQ_IHARD)
2449                 dm->dqb_ihardlimit = di->d_ino_hardlimit;
2450         if (di->d_fieldmask & (FS_DQ_ISOFT | FS_DQ_IHARD)) {
2451                 check_ilim = 1;
2452                 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2453         }
2454
2455         if (di->d_fieldmask & FS_DQ_BTIMER) {
2456                 dm->dqb_btime = di->d_btimer;
2457                 check_blim = 1;
2458                 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2459         }
2460
2461         if (di->d_fieldmask & FS_DQ_ITIMER) {
2462                 dm->dqb_itime = di->d_itimer;
2463                 check_ilim = 1;
2464                 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2465         }
2466
2467         if (check_blim) {
2468                 if (!dm->dqb_bsoftlimit ||
2469                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2470                         dm->dqb_btime = 0;
2471                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2472                 } else if (!(di->d_fieldmask & FS_DQ_BTIMER))
2473                         /* Set grace only if user hasn't provided his own... */
2474                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2475         }
2476         if (check_ilim) {
2477                 if (!dm->dqb_isoftlimit ||
2478                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2479                         dm->dqb_itime = 0;
2480                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2481                 } else if (!(di->d_fieldmask & FS_DQ_ITIMER))
2482                         /* Set grace only if user hasn't provided his own... */
2483                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2484         }
2485         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2486             dm->dqb_isoftlimit)
2487                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2488         else
2489                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2490         spin_unlock(&dq_data_lock);
2491         mark_dquot_dirty(dquot);
2492
2493         return 0;
2494 }
2495
2496 int dquot_set_dqblk(struct super_block *sb, struct kqid qid,
2497                   struct fs_disk_quota *di)
2498 {
2499         struct dquot *dquot;
2500         int rc;
2501
2502         dquot = dqget(sb, qid);
2503         if (!dquot) {
2504                 rc = -ESRCH;
2505                 goto out;
2506         }
2507         rc = do_set_dqblk(dquot, di);
2508         dqput(dquot);
2509 out:
2510         return rc;
2511 }
2512 EXPORT_SYMBOL(dquot_set_dqblk);
2513
2514 /* Generic routine for getting common part of quota file information */
2515 int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2516 {
2517         struct mem_dqinfo *mi;
2518   
2519         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2520         if (!sb_has_quota_active(sb, type)) {
2521                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2522                 return -ESRCH;
2523         }
2524         mi = sb_dqopt(sb)->info + type;
2525         spin_lock(&dq_data_lock);
2526         ii->dqi_bgrace = mi->dqi_bgrace;
2527         ii->dqi_igrace = mi->dqi_igrace;
2528         ii->dqi_flags = mi->dqi_flags & DQF_GETINFO_MASK;
2529         ii->dqi_valid = IIF_ALL;
2530         spin_unlock(&dq_data_lock);
2531         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2532         return 0;
2533 }
2534 EXPORT_SYMBOL(dquot_get_dqinfo);
2535
2536 /* Generic routine for setting common part of quota file information */
2537 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2538 {
2539         struct mem_dqinfo *mi;
2540         int err = 0;
2541
2542         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2543         if (!sb_has_quota_active(sb, type)) {
2544                 err = -ESRCH;
2545                 goto out;
2546         }
2547         mi = sb_dqopt(sb)->info + type;
2548         spin_lock(&dq_data_lock);
2549         if (ii->dqi_valid & IIF_BGRACE)
2550                 mi->dqi_bgrace = ii->dqi_bgrace;
2551         if (ii->dqi_valid & IIF_IGRACE)
2552                 mi->dqi_igrace = ii->dqi_igrace;
2553         if (ii->dqi_valid & IIF_FLAGS)
2554                 mi->dqi_flags = (mi->dqi_flags & ~DQF_SETINFO_MASK) |
2555                                 (ii->dqi_flags & DQF_SETINFO_MASK);
2556         spin_unlock(&dq_data_lock);
2557         mark_info_dirty(sb, type);
2558         /* Force write to disk */
2559         sb->dq_op->write_info(sb, type);
2560 out:
2561         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2562         return err;
2563 }
2564 EXPORT_SYMBOL(dquot_set_dqinfo);
2565
2566 const struct quotactl_ops dquot_quotactl_ops = {
2567         .quota_on       = dquot_quota_on,
2568         .quota_off      = dquot_quota_off,
2569         .quota_sync     = dquot_quota_sync,
2570         .get_info       = dquot_get_dqinfo,
2571         .set_info       = dquot_set_dqinfo,
2572         .get_dqblk      = dquot_get_dqblk,
2573         .set_dqblk      = dquot_set_dqblk
2574 };
2575 EXPORT_SYMBOL(dquot_quotactl_ops);
2576
2577 static int do_proc_dqstats(struct ctl_table *table, int write,
2578                      void __user *buffer, size_t *lenp, loff_t *ppos)
2579 {
2580         unsigned int type = (int *)table->data - dqstats.stat;
2581
2582         /* Update global table */
2583         dqstats.stat[type] =
2584                         percpu_counter_sum_positive(&dqstats.counter[type]);
2585         return proc_dointvec(table, write, buffer, lenp, ppos);
2586 }
2587
2588 static struct ctl_table fs_dqstats_table[] = {
2589         {
2590                 .procname       = "lookups",
2591                 .data           = &dqstats.stat[DQST_LOOKUPS],
2592                 .maxlen         = sizeof(int),
2593                 .mode           = 0444,
2594                 .proc_handler   = do_proc_dqstats,
2595         },
2596         {
2597                 .procname       = "drops",
2598                 .data           = &dqstats.stat[DQST_DROPS],
2599                 .maxlen         = sizeof(int),
2600                 .mode           = 0444,
2601                 .proc_handler   = do_proc_dqstats,
2602         },
2603         {
2604                 .procname       = "reads",
2605                 .data           = &dqstats.stat[DQST_READS],
2606                 .maxlen         = sizeof(int),
2607                 .mode           = 0444,
2608                 .proc_handler   = do_proc_dqstats,
2609         },
2610         {
2611                 .procname       = "writes",
2612                 .data           = &dqstats.stat[DQST_WRITES],
2613                 .maxlen         = sizeof(int),
2614                 .mode           = 0444,
2615                 .proc_handler   = do_proc_dqstats,
2616         },
2617         {
2618                 .procname       = "cache_hits",
2619                 .data           = &dqstats.stat[DQST_CACHE_HITS],
2620                 .maxlen         = sizeof(int),
2621                 .mode           = 0444,
2622                 .proc_handler   = do_proc_dqstats,
2623         },
2624         {
2625                 .procname       = "allocated_dquots",
2626                 .data           = &dqstats.stat[DQST_ALLOC_DQUOTS],
2627                 .maxlen         = sizeof(int),
2628                 .mode           = 0444,
2629                 .proc_handler   = do_proc_dqstats,
2630         },
2631         {
2632                 .procname       = "free_dquots",
2633                 .data           = &dqstats.stat[DQST_FREE_DQUOTS],
2634                 .maxlen         = sizeof(int),
2635                 .mode           = 0444,
2636                 .proc_handler   = do_proc_dqstats,
2637         },
2638         {
2639                 .procname       = "syncs",
2640                 .data           = &dqstats.stat[DQST_SYNCS],
2641                 .maxlen         = sizeof(int),
2642                 .mode           = 0444,
2643                 .proc_handler   = do_proc_dqstats,
2644         },
2645 #ifdef CONFIG_PRINT_QUOTA_WARNING
2646         {
2647                 .procname       = "warnings",
2648                 .data           = &flag_print_warnings,
2649                 .maxlen         = sizeof(int),
2650                 .mode           = 0644,
2651                 .proc_handler   = proc_dointvec,
2652         },
2653 #endif
2654         { },
2655 };
2656
2657 static struct ctl_table fs_table[] = {
2658         {
2659                 .procname       = "quota",
2660                 .mode           = 0555,
2661                 .child          = fs_dqstats_table,
2662         },
2663         { },
2664 };
2665
2666 static struct ctl_table sys_table[] = {
2667         {
2668                 .procname       = "fs",
2669                 .mode           = 0555,
2670                 .child          = fs_table,
2671         },
2672         { },
2673 };
2674
2675 static int __init dquot_init(void)
2676 {
2677         int i, ret;
2678         unsigned long nr_hash, order;
2679
2680         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2681
2682         register_sysctl_table(sys_table);
2683
2684         dquot_cachep = kmem_cache_create("dquot",
2685                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2686                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2687                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2688                         NULL);
2689
2690         order = 0;
2691         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2692         if (!dquot_hash)
2693                 panic("Cannot create dquot hash table");
2694
2695         for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
2696                 ret = percpu_counter_init(&dqstats.counter[i], 0);
2697                 if (ret)
2698                         panic("Cannot create dquot stat counters");
2699         }
2700
2701         /* Find power-of-two hlist_heads which can fit into allocation */
2702         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2703         dq_hash_bits = 0;
2704         do {
2705                 dq_hash_bits++;
2706         } while (nr_hash >> dq_hash_bits);
2707         dq_hash_bits--;
2708
2709         nr_hash = 1UL << dq_hash_bits;
2710         dq_hash_mask = nr_hash - 1;
2711         for (i = 0; i < nr_hash; i++)
2712                 INIT_HLIST_HEAD(dquot_hash + i);
2713
2714         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2715                         nr_hash, order, (PAGE_SIZE << order));
2716
2717         register_shrinker(&dqcache_shrinker);
2718
2719         return 0;
2720 }
2721 module_init(dquot_init);