Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
[sfrench/cifs-2.6.git] / fs / quota / dquot.c
1 /*
2  * Implementation of the diskquota system for the LINUX operating system. QUOTA
3  * is implemented using the BSD system call interface as the means of
4  * communication with the user level. This file contains the generic routines
5  * called by the different filesystems on allocation of an inode or block.
6  * These routines take care of the administration needed to have a consistent
7  * diskquota tracking system. The ideas of both user and group quotas are based
8  * on the Melbourne quota system as used on BSD derived systems. The internal
9  * implementation is based on one of the several variants of the LINUX
10  * inode-subsystem with added complexity of the diskquota system.
11  * 
12  * Author:      Marco van Wieringen <mvw@planets.elm.net>
13  *
14  * Fixes:   Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
15  *
16  *              Revised list management to avoid races
17  *              -- Bill Hawes, <whawes@star.net>, 9/98
18  *
19  *              Fixed races in dquot_transfer(), dqget() and dquot_alloc_...().
20  *              As the consequence the locking was moved from dquot_decr_...(),
21  *              dquot_incr_...() to calling functions.
22  *              invalidate_dquots() now writes modified dquots.
23  *              Serialized quota_off() and quota_on() for mount point.
24  *              Fixed a few bugs in grow_dquots().
25  *              Fixed deadlock in write_dquot() - we no longer account quotas on
26  *              quota files
27  *              remove_dquot_ref() moved to inode.c - it now traverses through inodes
28  *              add_dquot_ref() restarts after blocking
29  *              Added check for bogus uid and fixed check for group in quotactl.
30  *              Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99
31  *
32  *              Used struct list_head instead of own list struct
33  *              Invalidation of referenced dquots is no longer possible
34  *              Improved free_dquots list management
35  *              Quota and i_blocks are now updated in one place to avoid races
36  *              Warnings are now delayed so we won't block in critical section
37  *              Write updated not to require dquot lock
38  *              Jan Kara, <jack@suse.cz>, 9/2000
39  *
40  *              Added dynamic quota structure allocation
41  *              Jan Kara <jack@suse.cz> 12/2000
42  *
43  *              Rewritten quota interface. Implemented new quota format and
44  *              formats registering.
45  *              Jan Kara, <jack@suse.cz>, 2001,2002
46  *
47  *              New SMP locking.
48  *              Jan Kara, <jack@suse.cz>, 10/2002
49  *
50  *              Added journalled quota support, fix lock inversion problems
51  *              Jan Kara, <jack@suse.cz>, 2003,2004
52  *
53  * (C) Copyright 1994 - 1997 Marco van Wieringen 
54  */
55
56 #include <linux/errno.h>
57 #include <linux/kernel.h>
58 #include <linux/fs.h>
59 #include <linux/mount.h>
60 #include <linux/mm.h>
61 #include <linux/time.h>
62 #include <linux/types.h>
63 #include <linux/string.h>
64 #include <linux/fcntl.h>
65 #include <linux/stat.h>
66 #include <linux/tty.h>
67 #include <linux/file.h>
68 #include <linux/slab.h>
69 #include <linux/sysctl.h>
70 #include <linux/init.h>
71 #include <linux/module.h>
72 #include <linux/proc_fs.h>
73 #include <linux/security.h>
74 #include <linux/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  * Operation accessing dquots via inode pointers are protected by dquot_srcu.
100  * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and
101  * synchronize_srcu(&dquot_srcu) is called after clearing pointers from
102  * inode and before dropping dquot references to avoid use of dquots after
103  * they are freed. dq_data_lock is used to serialize the pointer setting and
104  * clearing operations.
105  * Special care needs to be taken about S_NOQUOTA inode flag (marking that
106  * inode is a quota file). Functions adding pointers from inode to dquots have
107  * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they
108  * have to do all pointer modifications before dropping dq_data_lock. This makes
109  * sure they cannot race with quotaon which first sets S_NOQUOTA flag and
110  * then drops all pointers to dquots from an inode.
111  *
112  * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
113  * from inodes (dquot_alloc_space() and such don't check the dq_lock).
114  * Currently dquot is locked only when it is being read to memory (or space for
115  * it is being allocated) on the first dqget() and when it is being released on
116  * the last dqput(). The allocation and release oparations are serialized by
117  * the dq_lock and by checking the use count in dquot_release().  Write
118  * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
119  * spinlock to internal buffers before writing.
120  *
121  * Lock ordering (including related VFS locks) is the following:
122  *   s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_mutex
123  */
124
125 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
126 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
127 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
128 EXPORT_SYMBOL(dq_data_lock);
129 DEFINE_STATIC_SRCU(dquot_srcu);
130
131 void __quota_error(struct super_block *sb, const char *func,
132                    const char *fmt, ...)
133 {
134         if (printk_ratelimit()) {
135                 va_list args;
136                 struct va_format vaf;
137
138                 va_start(args, fmt);
139
140                 vaf.fmt = fmt;
141                 vaf.va = &args;
142
143                 printk(KERN_ERR "Quota error (device %s): %s: %pV\n",
144                        sb->s_id, func, &vaf);
145
146                 va_end(args);
147         }
148 }
149 EXPORT_SYMBOL(__quota_error);
150
151 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING)
152 static char *quotatypes[] = INITQFNAMES;
153 #endif
154 static struct quota_format_type *quota_formats; /* List of registered formats */
155 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
156
157 /* SLAB cache for dquot structures */
158 static struct kmem_cache *dquot_cachep;
159
160 int register_quota_format(struct quota_format_type *fmt)
161 {
162         spin_lock(&dq_list_lock);
163         fmt->qf_next = quota_formats;
164         quota_formats = fmt;
165         spin_unlock(&dq_list_lock);
166         return 0;
167 }
168 EXPORT_SYMBOL(register_quota_format);
169
170 void unregister_quota_format(struct quota_format_type *fmt)
171 {
172         struct quota_format_type **actqf;
173
174         spin_lock(&dq_list_lock);
175         for (actqf = &quota_formats; *actqf && *actqf != fmt;
176              actqf = &(*actqf)->qf_next)
177                 ;
178         if (*actqf)
179                 *actqf = (*actqf)->qf_next;
180         spin_unlock(&dq_list_lock);
181 }
182 EXPORT_SYMBOL(unregister_quota_format);
183
184 static struct quota_format_type *find_quota_format(int id)
185 {
186         struct quota_format_type *actqf;
187
188         spin_lock(&dq_list_lock);
189         for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
190              actqf = actqf->qf_next)
191                 ;
192         if (!actqf || !try_module_get(actqf->qf_owner)) {
193                 int qm;
194
195                 spin_unlock(&dq_list_lock);
196                 
197                 for (qm = 0; module_names[qm].qm_fmt_id &&
198                              module_names[qm].qm_fmt_id != id; qm++)
199                         ;
200                 if (!module_names[qm].qm_fmt_id ||
201                     request_module(module_names[qm].qm_mod_name))
202                         return NULL;
203
204                 spin_lock(&dq_list_lock);
205                 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
206                      actqf = actqf->qf_next)
207                         ;
208                 if (actqf && !try_module_get(actqf->qf_owner))
209                         actqf = NULL;
210         }
211         spin_unlock(&dq_list_lock);
212         return actqf;
213 }
214
215 static void put_quota_format(struct quota_format_type *fmt)
216 {
217         module_put(fmt->qf_owner);
218 }
219
220 /*
221  * Dquot List Management:
222  * The quota code uses three lists for dquot management: the inuse_list,
223  * free_dquots, and dquot_hash[] array. A single dquot structure may be
224  * on all three lists, depending on its current state.
225  *
226  * All dquots are placed to the end of inuse_list when first created, and this
227  * list is used for invalidate operation, which must look at every dquot.
228  *
229  * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
230  * and this list is searched whenever we need an available dquot.  Dquots are
231  * removed from the list as soon as they are used again, and
232  * dqstats.free_dquots gives the number of dquots on the list. When
233  * dquot is invalidated it's completely released from memory.
234  *
235  * Dquots with a specific identity (device, type and id) are placed on
236  * one of the dquot_hash[] hash chains. The provides an efficient search
237  * mechanism to locate a specific dquot.
238  */
239
240 static LIST_HEAD(inuse_list);
241 static LIST_HEAD(free_dquots);
242 static unsigned int dq_hash_bits, dq_hash_mask;
243 static struct hlist_head *dquot_hash;
244
245 struct dqstats dqstats;
246 EXPORT_SYMBOL(dqstats);
247
248 static qsize_t inode_get_rsv_space(struct inode *inode);
249 static int __dquot_initialize(struct inode *inode, int type);
250
251 static inline unsigned int
252 hashfn(const struct super_block *sb, struct kqid qid)
253 {
254         unsigned int id = from_kqid(&init_user_ns, qid);
255         int type = qid.type;
256         unsigned long tmp;
257
258         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
259         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
260 }
261
262 /*
263  * Following list functions expect dq_list_lock to be held
264  */
265 static inline void insert_dquot_hash(struct dquot *dquot)
266 {
267         struct hlist_head *head;
268         head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id);
269         hlist_add_head(&dquot->dq_hash, head);
270 }
271
272 static inline void remove_dquot_hash(struct dquot *dquot)
273 {
274         hlist_del_init(&dquot->dq_hash);
275 }
276
277 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
278                                 struct kqid qid)
279 {
280         struct hlist_node *node;
281         struct dquot *dquot;
282
283         hlist_for_each (node, dquot_hash+hashent) {
284                 dquot = hlist_entry(node, struct dquot, dq_hash);
285                 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid))
286                         return dquot;
287         }
288         return NULL;
289 }
290
291 /* Add a dquot to the tail of the free list */
292 static inline void put_dquot_last(struct dquot *dquot)
293 {
294         list_add_tail(&dquot->dq_free, &free_dquots);
295         dqstats_inc(DQST_FREE_DQUOTS);
296 }
297
298 static inline void remove_free_dquot(struct dquot *dquot)
299 {
300         if (list_empty(&dquot->dq_free))
301                 return;
302         list_del_init(&dquot->dq_free);
303         dqstats_dec(DQST_FREE_DQUOTS);
304 }
305
306 static inline void put_inuse(struct dquot *dquot)
307 {
308         /* We add to the back of inuse list so we don't have to restart
309          * when traversing this list and we block */
310         list_add_tail(&dquot->dq_inuse, &inuse_list);
311         dqstats_inc(DQST_ALLOC_DQUOTS);
312 }
313
314 static inline void remove_inuse(struct dquot *dquot)
315 {
316         dqstats_dec(DQST_ALLOC_DQUOTS);
317         list_del(&dquot->dq_inuse);
318 }
319 /*
320  * End of list functions needing dq_list_lock
321  */
322
323 static void wait_on_dquot(struct dquot *dquot)
324 {
325         mutex_lock(&dquot->dq_lock);
326         mutex_unlock(&dquot->dq_lock);
327 }
328
329 static inline int dquot_dirty(struct dquot *dquot)
330 {
331         return test_bit(DQ_MOD_B, &dquot->dq_flags);
332 }
333
334 static inline int mark_dquot_dirty(struct dquot *dquot)
335 {
336         return dquot->dq_sb->dq_op->mark_dirty(dquot);
337 }
338
339 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */
340 int dquot_mark_dquot_dirty(struct dquot *dquot)
341 {
342         int ret = 1;
343
344         /* If quota is dirty already, we don't have to acquire dq_list_lock */
345         if (test_bit(DQ_MOD_B, &dquot->dq_flags))
346                 return 1;
347
348         spin_lock(&dq_list_lock);
349         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) {
350                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
351                                 info[dquot->dq_id.type].dqi_dirty_list);
352                 ret = 0;
353         }
354         spin_unlock(&dq_list_lock);
355         return ret;
356 }
357 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
358
359 /* Dirtify all the dquots - this can block when journalling */
360 static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
361 {
362         int ret, err, cnt;
363
364         ret = err = 0;
365         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
366                 if (dquot[cnt])
367                         /* Even in case of error we have to continue */
368                         ret = mark_dquot_dirty(dquot[cnt]);
369                 if (!err)
370                         err = ret;
371         }
372         return err;
373 }
374
375 static inline void dqput_all(struct dquot **dquot)
376 {
377         unsigned int cnt;
378
379         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
380                 dqput(dquot[cnt]);
381 }
382
383 /* This function needs dq_list_lock */
384 static inline int clear_dquot_dirty(struct dquot *dquot)
385 {
386         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
387                 return 0;
388         list_del_init(&dquot->dq_dirty);
389         return 1;
390 }
391
392 void mark_info_dirty(struct super_block *sb, int type)
393 {
394         set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
395 }
396 EXPORT_SYMBOL(mark_info_dirty);
397
398 /*
399  *      Read dquot from disk and alloc space for it
400  */
401
402 int dquot_acquire(struct dquot *dquot)
403 {
404         int ret = 0, ret2 = 0;
405         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
406
407         mutex_lock(&dquot->dq_lock);
408         mutex_lock(&dqopt->dqio_mutex);
409         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
410                 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
411         if (ret < 0)
412                 goto out_iolock;
413         /* Make sure flags update is visible after dquot has been filled */
414         smp_mb__before_atomic();
415         set_bit(DQ_READ_B, &dquot->dq_flags);
416         /* Instantiate dquot if needed */
417         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
418                 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
419                 /* Write the info if needed */
420                 if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
421                         ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
422                                         dquot->dq_sb, dquot->dq_id.type);
423                 }
424                 if (ret < 0)
425                         goto out_iolock;
426                 if (ret2 < 0) {
427                         ret = ret2;
428                         goto out_iolock;
429                 }
430         }
431         /*
432          * Make sure flags update is visible after on-disk struct has been
433          * allocated. Paired with smp_rmb() in dqget().
434          */
435         smp_mb__before_atomic();
436         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
437 out_iolock:
438         mutex_unlock(&dqopt->dqio_mutex);
439         mutex_unlock(&dquot->dq_lock);
440         return ret;
441 }
442 EXPORT_SYMBOL(dquot_acquire);
443
444 /*
445  *      Write dquot to disk
446  */
447 int dquot_commit(struct dquot *dquot)
448 {
449         int ret = 0;
450         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
451
452         mutex_lock(&dqopt->dqio_mutex);
453         spin_lock(&dq_list_lock);
454         if (!clear_dquot_dirty(dquot)) {
455                 spin_unlock(&dq_list_lock);
456                 goto out_sem;
457         }
458         spin_unlock(&dq_list_lock);
459         /* Inactive dquot can be only if there was error during read/init
460          * => we have better not writing it */
461         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
462                 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
463         else
464                 ret = -EIO;
465 out_sem:
466         mutex_unlock(&dqopt->dqio_mutex);
467         return ret;
468 }
469 EXPORT_SYMBOL(dquot_commit);
470
471 /*
472  *      Release dquot
473  */
474 int dquot_release(struct dquot *dquot)
475 {
476         int ret = 0, ret2 = 0;
477         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
478
479         mutex_lock(&dquot->dq_lock);
480         /* Check whether we are not racing with some other dqget() */
481         if (atomic_read(&dquot->dq_count) > 1)
482                 goto out_dqlock;
483         mutex_lock(&dqopt->dqio_mutex);
484         if (dqopt->ops[dquot->dq_id.type]->release_dqblk) {
485                 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot);
486                 /* Write the info */
487                 if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
488                         ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
489                                                 dquot->dq_sb, dquot->dq_id.type);
490                 }
491                 if (ret >= 0)
492                         ret = ret2;
493         }
494         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
495         mutex_unlock(&dqopt->dqio_mutex);
496 out_dqlock:
497         mutex_unlock(&dquot->dq_lock);
498         return ret;
499 }
500 EXPORT_SYMBOL(dquot_release);
501
502 void dquot_destroy(struct dquot *dquot)
503 {
504         kmem_cache_free(dquot_cachep, dquot);
505 }
506 EXPORT_SYMBOL(dquot_destroy);
507
508 static inline void do_destroy_dquot(struct dquot *dquot)
509 {
510         dquot->dq_sb->dq_op->destroy_dquot(dquot);
511 }
512
513 /* Invalidate all dquots on the list. Note that this function is called after
514  * quota is disabled and pointers from inodes removed so there cannot be new
515  * quota users. There can still be some users of quotas due to inodes being
516  * just deleted or pruned by prune_icache() (those are not attached to any
517  * list) or parallel quotactl call. We have to wait for such users.
518  */
519 static void invalidate_dquots(struct super_block *sb, int type)
520 {
521         struct dquot *dquot, *tmp;
522
523 restart:
524         spin_lock(&dq_list_lock);
525         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
526                 if (dquot->dq_sb != sb)
527                         continue;
528                 if (dquot->dq_id.type != type)
529                         continue;
530                 /* Wait for dquot users */
531                 if (atomic_read(&dquot->dq_count)) {
532                         DEFINE_WAIT(wait);
533
534                         dqgrab(dquot);
535                         prepare_to_wait(&dquot->dq_wait_unused, &wait,
536                                         TASK_UNINTERRUPTIBLE);
537                         spin_unlock(&dq_list_lock);
538                         /* Once dqput() wakes us up, we know it's time to free
539                          * the dquot.
540                          * IMPORTANT: we rely on the fact that there is always
541                          * at most one process waiting for dquot to free.
542                          * Otherwise dq_count would be > 1 and we would never
543                          * wake up.
544                          */
545                         if (atomic_read(&dquot->dq_count) > 1)
546                                 schedule();
547                         finish_wait(&dquot->dq_wait_unused, &wait);
548                         dqput(dquot);
549                         /* At this moment dquot() need not exist (it could be
550                          * reclaimed by prune_dqcache(). Hence we must
551                          * restart. */
552                         goto restart;
553                 }
554                 /*
555                  * Quota now has no users and it has been written on last
556                  * dqput()
557                  */
558                 remove_dquot_hash(dquot);
559                 remove_free_dquot(dquot);
560                 remove_inuse(dquot);
561                 do_destroy_dquot(dquot);
562         }
563         spin_unlock(&dq_list_lock);
564 }
565
566 /* Call callback for every active dquot on given filesystem */
567 int dquot_scan_active(struct super_block *sb,
568                       int (*fn)(struct dquot *dquot, unsigned long priv),
569                       unsigned long priv)
570 {
571         struct dquot *dquot, *old_dquot = NULL;
572         int ret = 0;
573
574         WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount));
575
576         spin_lock(&dq_list_lock);
577         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
578                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
579                         continue;
580                 if (dquot->dq_sb != sb)
581                         continue;
582                 /* Now we have active dquot so we can just increase use count */
583                 atomic_inc(&dquot->dq_count);
584                 spin_unlock(&dq_list_lock);
585                 dqstats_inc(DQST_LOOKUPS);
586                 dqput(old_dquot);
587                 old_dquot = dquot;
588                 /*
589                  * ->release_dquot() can be racing with us. Our reference
590                  * protects us from new calls to it so just wait for any
591                  * outstanding call and recheck the DQ_ACTIVE_B after that.
592                  */
593                 wait_on_dquot(dquot);
594                 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
595                         ret = fn(dquot, priv);
596                         if (ret < 0)
597                                 goto out;
598                 }
599                 spin_lock(&dq_list_lock);
600                 /* We are safe to continue now because our dquot could not
601                  * be moved out of the inuse list while we hold the reference */
602         }
603         spin_unlock(&dq_list_lock);
604 out:
605         dqput(old_dquot);
606         return ret;
607 }
608 EXPORT_SYMBOL(dquot_scan_active);
609
610 /* Write all dquot structures to quota files */
611 int dquot_writeback_dquots(struct super_block *sb, int type)
612 {
613         struct list_head *dirty;
614         struct dquot *dquot;
615         struct quota_info *dqopt = sb_dqopt(sb);
616         int cnt;
617         int err, ret = 0;
618
619         WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount));
620
621         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
622                 if (type != -1 && cnt != type)
623                         continue;
624                 if (!sb_has_quota_active(sb, cnt))
625                         continue;
626                 spin_lock(&dq_list_lock);
627                 dirty = &dqopt->info[cnt].dqi_dirty_list;
628                 while (!list_empty(dirty)) {
629                         dquot = list_first_entry(dirty, struct dquot,
630                                                  dq_dirty);
631                         /* Dirty and inactive can be only bad dquot... */
632                         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
633                                 clear_dquot_dirty(dquot);
634                                 continue;
635                         }
636                         /* Now we have active dquot from which someone is
637                          * holding reference so we can safely just increase
638                          * use count */
639                         dqgrab(dquot);
640                         spin_unlock(&dq_list_lock);
641                         dqstats_inc(DQST_LOOKUPS);
642                         err = sb->dq_op->write_dquot(dquot);
643                         if (!ret && err)
644                                 ret = err;
645                         dqput(dquot);
646                         spin_lock(&dq_list_lock);
647                 }
648                 spin_unlock(&dq_list_lock);
649         }
650
651         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
652                 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
653                     && info_dirty(&dqopt->info[cnt]))
654                         sb->dq_op->write_info(sb, cnt);
655         dqstats_inc(DQST_SYNCS);
656
657         return ret;
658 }
659 EXPORT_SYMBOL(dquot_writeback_dquots);
660
661 /* Write all dquot structures to disk and make them visible from userspace */
662 int dquot_quota_sync(struct super_block *sb, int type)
663 {
664         struct quota_info *dqopt = sb_dqopt(sb);
665         int cnt;
666         int ret;
667
668         ret = dquot_writeback_dquots(sb, type);
669         if (ret)
670                 return ret;
671         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
672                 return 0;
673
674         /* This is not very clever (and fast) but currently I don't know about
675          * any other simple way of getting quota data to disk and we must get
676          * them there for userspace to be visible... */
677         if (sb->s_op->sync_fs)
678                 sb->s_op->sync_fs(sb, 1);
679         sync_blockdev(sb->s_bdev);
680
681         /*
682          * Now when everything is written we can discard the pagecache so
683          * that userspace sees the changes.
684          */
685         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
686                 if (type != -1 && cnt != type)
687                         continue;
688                 if (!sb_has_quota_active(sb, cnt))
689                         continue;
690                 inode_lock(dqopt->files[cnt]);
691                 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
692                 inode_unlock(dqopt->files[cnt]);
693         }
694
695         return 0;
696 }
697 EXPORT_SYMBOL(dquot_quota_sync);
698
699 static unsigned long
700 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
701 {
702         struct list_head *head;
703         struct dquot *dquot;
704         unsigned long freed = 0;
705
706         spin_lock(&dq_list_lock);
707         head = free_dquots.prev;
708         while (head != &free_dquots && sc->nr_to_scan) {
709                 dquot = list_entry(head, struct dquot, dq_free);
710                 remove_dquot_hash(dquot);
711                 remove_free_dquot(dquot);
712                 remove_inuse(dquot);
713                 do_destroy_dquot(dquot);
714                 sc->nr_to_scan--;
715                 freed++;
716                 head = free_dquots.prev;
717         }
718         spin_unlock(&dq_list_lock);
719         return freed;
720 }
721
722 static unsigned long
723 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
724 {
725         return vfs_pressure_ratio(
726         percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]));
727 }
728
729 static struct shrinker dqcache_shrinker = {
730         .count_objects = dqcache_shrink_count,
731         .scan_objects = dqcache_shrink_scan,
732         .seeks = DEFAULT_SEEKS,
733 };
734
735 /*
736  * Put reference to dquot
737  */
738 void dqput(struct dquot *dquot)
739 {
740         int ret;
741
742         if (!dquot)
743                 return;
744 #ifdef CONFIG_QUOTA_DEBUG
745         if (!atomic_read(&dquot->dq_count)) {
746                 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d",
747                             quotatypes[dquot->dq_id.type],
748                             from_kqid(&init_user_ns, dquot->dq_id));
749                 BUG();
750         }
751 #endif
752         dqstats_inc(DQST_DROPS);
753 we_slept:
754         spin_lock(&dq_list_lock);
755         if (atomic_read(&dquot->dq_count) > 1) {
756                 /* We have more than one user... nothing to do */
757                 atomic_dec(&dquot->dq_count);
758                 /* Releasing dquot during quotaoff phase? */
759                 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) &&
760                     atomic_read(&dquot->dq_count) == 1)
761                         wake_up(&dquot->dq_wait_unused);
762                 spin_unlock(&dq_list_lock);
763                 return;
764         }
765         /* Need to release dquot? */
766         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
767                 spin_unlock(&dq_list_lock);
768                 /* Commit dquot before releasing */
769                 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
770                 if (ret < 0) {
771                         quota_error(dquot->dq_sb, "Can't write quota structure"
772                                     " (error %d). Quota may get out of sync!",
773                                     ret);
774                         /*
775                          * We clear dirty bit anyway, so that we avoid
776                          * infinite loop here
777                          */
778                         spin_lock(&dq_list_lock);
779                         clear_dquot_dirty(dquot);
780                         spin_unlock(&dq_list_lock);
781                 }
782                 goto we_slept;
783         }
784         /* Clear flag in case dquot was inactive (something bad happened) */
785         clear_dquot_dirty(dquot);
786         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
787                 spin_unlock(&dq_list_lock);
788                 dquot->dq_sb->dq_op->release_dquot(dquot);
789                 goto we_slept;
790         }
791         atomic_dec(&dquot->dq_count);
792 #ifdef CONFIG_QUOTA_DEBUG
793         /* sanity check */
794         BUG_ON(!list_empty(&dquot->dq_free));
795 #endif
796         put_dquot_last(dquot);
797         spin_unlock(&dq_list_lock);
798 }
799 EXPORT_SYMBOL(dqput);
800
801 struct dquot *dquot_alloc(struct super_block *sb, int type)
802 {
803         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
804 }
805 EXPORT_SYMBOL(dquot_alloc);
806
807 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
808 {
809         struct dquot *dquot;
810
811         dquot = sb->dq_op->alloc_dquot(sb, type);
812         if(!dquot)
813                 return NULL;
814
815         mutex_init(&dquot->dq_lock);
816         INIT_LIST_HEAD(&dquot->dq_free);
817         INIT_LIST_HEAD(&dquot->dq_inuse);
818         INIT_HLIST_NODE(&dquot->dq_hash);
819         INIT_LIST_HEAD(&dquot->dq_dirty);
820         init_waitqueue_head(&dquot->dq_wait_unused);
821         dquot->dq_sb = sb;
822         dquot->dq_id = make_kqid_invalid(type);
823         atomic_set(&dquot->dq_count, 1);
824
825         return dquot;
826 }
827
828 /*
829  * Get reference to dquot
830  *
831  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
832  * destroying our dquot by:
833  *   a) checking for quota flags under dq_list_lock and
834  *   b) getting a reference to dquot before we release dq_list_lock
835  */
836 struct dquot *dqget(struct super_block *sb, struct kqid qid)
837 {
838         unsigned int hashent = hashfn(sb, qid);
839         struct dquot *dquot, *empty = NULL;
840
841         if (!qid_has_mapping(sb->s_user_ns, qid))
842                 return ERR_PTR(-EINVAL);
843
844         if (!sb_has_quota_active(sb, qid.type))
845                 return ERR_PTR(-ESRCH);
846 we_slept:
847         spin_lock(&dq_list_lock);
848         spin_lock(&dq_state_lock);
849         if (!sb_has_quota_active(sb, qid.type)) {
850                 spin_unlock(&dq_state_lock);
851                 spin_unlock(&dq_list_lock);
852                 dquot = ERR_PTR(-ESRCH);
853                 goto out;
854         }
855         spin_unlock(&dq_state_lock);
856
857         dquot = find_dquot(hashent, sb, qid);
858         if (!dquot) {
859                 if (!empty) {
860                         spin_unlock(&dq_list_lock);
861                         empty = get_empty_dquot(sb, qid.type);
862                         if (!empty)
863                                 schedule();     /* Try to wait for a moment... */
864                         goto we_slept;
865                 }
866                 dquot = empty;
867                 empty = NULL;
868                 dquot->dq_id = qid;
869                 /* all dquots go on the inuse_list */
870                 put_inuse(dquot);
871                 /* hash it first so it can be found */
872                 insert_dquot_hash(dquot);
873                 spin_unlock(&dq_list_lock);
874                 dqstats_inc(DQST_LOOKUPS);
875         } else {
876                 if (!atomic_read(&dquot->dq_count))
877                         remove_free_dquot(dquot);
878                 atomic_inc(&dquot->dq_count);
879                 spin_unlock(&dq_list_lock);
880                 dqstats_inc(DQST_CACHE_HITS);
881                 dqstats_inc(DQST_LOOKUPS);
882         }
883         /* Wait for dq_lock - after this we know that either dquot_release() is
884          * already finished or it will be canceled due to dq_count > 1 test */
885         wait_on_dquot(dquot);
886         /* Read the dquot / allocate space in quota file */
887         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
888                 int err;
889
890                 err = sb->dq_op->acquire_dquot(dquot);
891                 if (err < 0) {
892                         dqput(dquot);
893                         dquot = ERR_PTR(err);
894                         goto out;
895                 }
896         }
897         /*
898          * Make sure following reads see filled structure - paired with
899          * smp_mb__before_atomic() in dquot_acquire().
900          */
901         smp_rmb();
902 #ifdef CONFIG_QUOTA_DEBUG
903         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
904 #endif
905 out:
906         if (empty)
907                 do_destroy_dquot(empty);
908
909         return dquot;
910 }
911 EXPORT_SYMBOL(dqget);
912
913 static inline struct dquot **i_dquot(struct inode *inode)
914 {
915         return inode->i_sb->s_op->get_dquots(inode);
916 }
917
918 static int dqinit_needed(struct inode *inode, int type)
919 {
920         struct dquot * const *dquots;
921         int cnt;
922
923         if (IS_NOQUOTA(inode))
924                 return 0;
925
926         dquots = i_dquot(inode);
927         if (type != -1)
928                 return !dquots[type];
929         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
930                 if (!dquots[cnt])
931                         return 1;
932         return 0;
933 }
934
935 /* This routine is guarded by s_umount semaphore */
936 static void add_dquot_ref(struct super_block *sb, int type)
937 {
938         struct inode *inode, *old_inode = NULL;
939 #ifdef CONFIG_QUOTA_DEBUG
940         int reserved = 0;
941 #endif
942
943         spin_lock(&sb->s_inode_list_lock);
944         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
945                 spin_lock(&inode->i_lock);
946                 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
947                     !atomic_read(&inode->i_writecount) ||
948                     !dqinit_needed(inode, type)) {
949                         spin_unlock(&inode->i_lock);
950                         continue;
951                 }
952                 __iget(inode);
953                 spin_unlock(&inode->i_lock);
954                 spin_unlock(&sb->s_inode_list_lock);
955
956 #ifdef CONFIG_QUOTA_DEBUG
957                 if (unlikely(inode_get_rsv_space(inode) > 0))
958                         reserved = 1;
959 #endif
960                 iput(old_inode);
961                 __dquot_initialize(inode, type);
962
963                 /*
964                  * We hold a reference to 'inode' so it couldn't have been
965                  * removed from s_inodes list while we dropped the
966                  * s_inode_list_lock. We cannot iput the inode now as we can be
967                  * holding the last reference and we cannot iput it under
968                  * s_inode_list_lock. So we keep the reference and iput it
969                  * later.
970                  */
971                 old_inode = inode;
972                 spin_lock(&sb->s_inode_list_lock);
973         }
974         spin_unlock(&sb->s_inode_list_lock);
975         iput(old_inode);
976
977 #ifdef CONFIG_QUOTA_DEBUG
978         if (reserved) {
979                 quota_error(sb, "Writes happened before quota was turned on "
980                         "thus quota information is probably inconsistent. "
981                         "Please run quotacheck(8)");
982         }
983 #endif
984 }
985
986 /*
987  * Remove references to dquots from inode and add dquot to list for freeing
988  * if we have the last reference to dquot
989  */
990 static void remove_inode_dquot_ref(struct inode *inode, int type,
991                                    struct list_head *tofree_head)
992 {
993         struct dquot **dquots = i_dquot(inode);
994         struct dquot *dquot = dquots[type];
995
996         if (!dquot)
997                 return;
998
999         dquots[type] = NULL;
1000         if (list_empty(&dquot->dq_free)) {
1001                 /*
1002                  * The inode still has reference to dquot so it can't be in the
1003                  * free list
1004                  */
1005                 spin_lock(&dq_list_lock);
1006                 list_add(&dquot->dq_free, tofree_head);
1007                 spin_unlock(&dq_list_lock);
1008         } else {
1009                 /*
1010                  * Dquot is already in a list to put so we won't drop the last
1011                  * reference here.
1012                  */
1013                 dqput(dquot);
1014         }
1015 }
1016
1017 /*
1018  * Free list of dquots
1019  * Dquots are removed from inodes and no new references can be got so we are
1020  * the only ones holding reference
1021  */
1022 static void put_dquot_list(struct list_head *tofree_head)
1023 {
1024         struct list_head *act_head;
1025         struct dquot *dquot;
1026
1027         act_head = tofree_head->next;
1028         while (act_head != tofree_head) {
1029                 dquot = list_entry(act_head, struct dquot, dq_free);
1030                 act_head = act_head->next;
1031                 /* Remove dquot from the list so we won't have problems... */
1032                 list_del_init(&dquot->dq_free);
1033                 dqput(dquot);
1034         }
1035 }
1036
1037 static void remove_dquot_ref(struct super_block *sb, int type,
1038                 struct list_head *tofree_head)
1039 {
1040         struct inode *inode;
1041         int reserved = 0;
1042
1043         spin_lock(&sb->s_inode_list_lock);
1044         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
1045                 /*
1046                  *  We have to scan also I_NEW inodes because they can already
1047                  *  have quota pointer initialized. Luckily, we need to touch
1048                  *  only quota pointers and these have separate locking
1049                  *  (dq_data_lock).
1050                  */
1051                 spin_lock(&dq_data_lock);
1052                 if (!IS_NOQUOTA(inode)) {
1053                         if (unlikely(inode_get_rsv_space(inode) > 0))
1054                                 reserved = 1;
1055                         remove_inode_dquot_ref(inode, type, tofree_head);
1056                 }
1057                 spin_unlock(&dq_data_lock);
1058         }
1059         spin_unlock(&sb->s_inode_list_lock);
1060 #ifdef CONFIG_QUOTA_DEBUG
1061         if (reserved) {
1062                 printk(KERN_WARNING "VFS (%s): Writes happened after quota"
1063                         " was disabled thus quota information is probably "
1064                         "inconsistent. Please run quotacheck(8).\n", sb->s_id);
1065         }
1066 #endif
1067 }
1068
1069 /* Gather all references from inodes and drop them */
1070 static void drop_dquot_ref(struct super_block *sb, int type)
1071 {
1072         LIST_HEAD(tofree_head);
1073
1074         if (sb->dq_op) {
1075                 remove_dquot_ref(sb, type, &tofree_head);
1076                 synchronize_srcu(&dquot_srcu);
1077                 put_dquot_list(&tofree_head);
1078         }
1079 }
1080
1081 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
1082 {
1083         dquot->dq_dqb.dqb_curinodes += number;
1084 }
1085
1086 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
1087 {
1088         dquot->dq_dqb.dqb_curspace += number;
1089 }
1090
1091 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
1092 {
1093         dquot->dq_dqb.dqb_rsvspace += number;
1094 }
1095
1096 /*
1097  * Claim reserved quota space
1098  */
1099 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number)
1100 {
1101         if (dquot->dq_dqb.dqb_rsvspace < number) {
1102                 WARN_ON_ONCE(1);
1103                 number = dquot->dq_dqb.dqb_rsvspace;
1104         }
1105         dquot->dq_dqb.dqb_curspace += number;
1106         dquot->dq_dqb.dqb_rsvspace -= number;
1107 }
1108
1109 static void dquot_reclaim_reserved_space(struct dquot *dquot, qsize_t number)
1110 {
1111         if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number))
1112                 number = dquot->dq_dqb.dqb_curspace;
1113         dquot->dq_dqb.dqb_rsvspace += number;
1114         dquot->dq_dqb.dqb_curspace -= number;
1115 }
1116
1117 static inline
1118 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
1119 {
1120         if (dquot->dq_dqb.dqb_rsvspace >= number)
1121                 dquot->dq_dqb.dqb_rsvspace -= number;
1122         else {
1123                 WARN_ON_ONCE(1);
1124                 dquot->dq_dqb.dqb_rsvspace = 0;
1125         }
1126 }
1127
1128 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1129 {
1130         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1131             dquot->dq_dqb.dqb_curinodes >= number)
1132                 dquot->dq_dqb.dqb_curinodes -= number;
1133         else
1134                 dquot->dq_dqb.dqb_curinodes = 0;
1135         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1136                 dquot->dq_dqb.dqb_itime = (time64_t) 0;
1137         clear_bit(DQ_INODES_B, &dquot->dq_flags);
1138 }
1139
1140 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1141 {
1142         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1143             dquot->dq_dqb.dqb_curspace >= number)
1144                 dquot->dq_dqb.dqb_curspace -= number;
1145         else
1146                 dquot->dq_dqb.dqb_curspace = 0;
1147         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1148                 dquot->dq_dqb.dqb_btime = (time64_t) 0;
1149         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1150 }
1151
1152 struct dquot_warn {
1153         struct super_block *w_sb;
1154         struct kqid w_dq_id;
1155         short w_type;
1156 };
1157
1158 static int warning_issued(struct dquot *dquot, const int warntype)
1159 {
1160         int flag = (warntype == QUOTA_NL_BHARDWARN ||
1161                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1162                 ((warntype == QUOTA_NL_IHARDWARN ||
1163                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1164
1165         if (!flag)
1166                 return 0;
1167         return test_and_set_bit(flag, &dquot->dq_flags);
1168 }
1169
1170 #ifdef CONFIG_PRINT_QUOTA_WARNING
1171 static int flag_print_warnings = 1;
1172
1173 static int need_print_warning(struct dquot_warn *warn)
1174 {
1175         if (!flag_print_warnings)
1176                 return 0;
1177
1178         switch (warn->w_dq_id.type) {
1179                 case USRQUOTA:
1180                         return uid_eq(current_fsuid(), warn->w_dq_id.uid);
1181                 case GRPQUOTA:
1182                         return in_group_p(warn->w_dq_id.gid);
1183                 case PRJQUOTA:
1184                         return 1;
1185         }
1186         return 0;
1187 }
1188
1189 /* Print warning to user which exceeded quota */
1190 static void print_warning(struct dquot_warn *warn)
1191 {
1192         char *msg = NULL;
1193         struct tty_struct *tty;
1194         int warntype = warn->w_type;
1195
1196         if (warntype == QUOTA_NL_IHARDBELOW ||
1197             warntype == QUOTA_NL_ISOFTBELOW ||
1198             warntype == QUOTA_NL_BHARDBELOW ||
1199             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn))
1200                 return;
1201
1202         tty = get_current_tty();
1203         if (!tty)
1204                 return;
1205         tty_write_message(tty, warn->w_sb->s_id);
1206         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1207                 tty_write_message(tty, ": warning, ");
1208         else
1209                 tty_write_message(tty, ": write failed, ");
1210         tty_write_message(tty, quotatypes[warn->w_dq_id.type]);
1211         switch (warntype) {
1212                 case QUOTA_NL_IHARDWARN:
1213                         msg = " file limit reached.\r\n";
1214                         break;
1215                 case QUOTA_NL_ISOFTLONGWARN:
1216                         msg = " file quota exceeded too long.\r\n";
1217                         break;
1218                 case QUOTA_NL_ISOFTWARN:
1219                         msg = " file quota exceeded.\r\n";
1220                         break;
1221                 case QUOTA_NL_BHARDWARN:
1222                         msg = " block limit reached.\r\n";
1223                         break;
1224                 case QUOTA_NL_BSOFTLONGWARN:
1225                         msg = " block quota exceeded too long.\r\n";
1226                         break;
1227                 case QUOTA_NL_BSOFTWARN:
1228                         msg = " block quota exceeded.\r\n";
1229                         break;
1230         }
1231         tty_write_message(tty, msg);
1232         tty_kref_put(tty);
1233 }
1234 #endif
1235
1236 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot,
1237                             int warntype)
1238 {
1239         if (warning_issued(dquot, warntype))
1240                 return;
1241         warn->w_type = warntype;
1242         warn->w_sb = dquot->dq_sb;
1243         warn->w_dq_id = dquot->dq_id;
1244 }
1245
1246 /*
1247  * Write warnings to the console and send warning messages over netlink.
1248  *
1249  * Note that this function can call into tty and networking code.
1250  */
1251 static void flush_warnings(struct dquot_warn *warn)
1252 {
1253         int i;
1254
1255         for (i = 0; i < MAXQUOTAS; i++) {
1256                 if (warn[i].w_type == QUOTA_NL_NOWARN)
1257                         continue;
1258 #ifdef CONFIG_PRINT_QUOTA_WARNING
1259                 print_warning(&warn[i]);
1260 #endif
1261                 quota_send_warning(warn[i].w_dq_id,
1262                                    warn[i].w_sb->s_dev, warn[i].w_type);
1263         }
1264 }
1265
1266 static int ignore_hardlimit(struct dquot *dquot)
1267 {
1268         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
1269
1270         return capable(CAP_SYS_RESOURCE) &&
1271                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1272                 !(info->dqi_flags & DQF_ROOT_SQUASH));
1273 }
1274
1275 /* needs dq_data_lock */
1276 static int check_idq(struct dquot *dquot, qsize_t inodes,
1277                      struct dquot_warn *warn)
1278 {
1279         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1280
1281         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) ||
1282             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1283                 return 0;
1284
1285         if (dquot->dq_dqb.dqb_ihardlimit &&
1286             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1287             !ignore_hardlimit(dquot)) {
1288                 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN);
1289                 return -EDQUOT;
1290         }
1291
1292         if (dquot->dq_dqb.dqb_isoftlimit &&
1293             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1294             dquot->dq_dqb.dqb_itime &&
1295             ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime &&
1296             !ignore_hardlimit(dquot)) {
1297                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN);
1298                 return -EDQUOT;
1299         }
1300
1301         if (dquot->dq_dqb.dqb_isoftlimit &&
1302             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1303             dquot->dq_dqb.dqb_itime == 0) {
1304                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN);
1305                 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() +
1306                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace;
1307         }
1308
1309         return 0;
1310 }
1311
1312 /* needs dq_data_lock */
1313 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc,
1314                      struct dquot_warn *warn)
1315 {
1316         qsize_t tspace;
1317         struct super_block *sb = dquot->dq_sb;
1318
1319         if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) ||
1320             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1321                 return 0;
1322
1323         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1324                 + space;
1325
1326         if (dquot->dq_dqb.dqb_bhardlimit &&
1327             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1328             !ignore_hardlimit(dquot)) {
1329                 if (!prealloc)
1330                         prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN);
1331                 return -EDQUOT;
1332         }
1333
1334         if (dquot->dq_dqb.dqb_bsoftlimit &&
1335             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1336             dquot->dq_dqb.dqb_btime &&
1337             ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime &&
1338             !ignore_hardlimit(dquot)) {
1339                 if (!prealloc)
1340                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN);
1341                 return -EDQUOT;
1342         }
1343
1344         if (dquot->dq_dqb.dqb_bsoftlimit &&
1345             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1346             dquot->dq_dqb.dqb_btime == 0) {
1347                 if (!prealloc) {
1348                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN);
1349                         dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() +
1350                             sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace;
1351                 }
1352                 else
1353                         /*
1354                          * We don't allow preallocation to exceed softlimit so exceeding will
1355                          * be always printed
1356                          */
1357                         return -EDQUOT;
1358         }
1359
1360         return 0;
1361 }
1362
1363 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1364 {
1365         qsize_t newinodes;
1366
1367         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1368             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1369             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type))
1370                 return QUOTA_NL_NOWARN;
1371
1372         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1373         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1374                 return QUOTA_NL_ISOFTBELOW;
1375         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1376             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1377                 return QUOTA_NL_IHARDBELOW;
1378         return QUOTA_NL_NOWARN;
1379 }
1380
1381 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1382 {
1383         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1384             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1385                 return QUOTA_NL_NOWARN;
1386
1387         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1388                 return QUOTA_NL_BSOFTBELOW;
1389         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1390             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1391                 return QUOTA_NL_BHARDBELOW;
1392         return QUOTA_NL_NOWARN;
1393 }
1394
1395 static int dquot_active(const struct inode *inode)
1396 {
1397         struct super_block *sb = inode->i_sb;
1398
1399         if (IS_NOQUOTA(inode))
1400                 return 0;
1401         return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
1402 }
1403
1404 /*
1405  * Initialize quota pointers in inode
1406  *
1407  * It is better to call this function outside of any transaction as it
1408  * might need a lot of space in journal for dquot structure allocation.
1409  */
1410 static int __dquot_initialize(struct inode *inode, int type)
1411 {
1412         int cnt, init_needed = 0;
1413         struct dquot **dquots, *got[MAXQUOTAS] = {};
1414         struct super_block *sb = inode->i_sb;
1415         qsize_t rsv;
1416         int ret = 0;
1417
1418         if (!dquot_active(inode))
1419                 return 0;
1420
1421         dquots = i_dquot(inode);
1422
1423         /* First get references to structures we might need. */
1424         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1425                 struct kqid qid;
1426                 kprojid_t projid;
1427                 int rc;
1428                 struct dquot *dquot;
1429
1430                 if (type != -1 && cnt != type)
1431                         continue;
1432                 /*
1433                  * The i_dquot should have been initialized in most cases,
1434                  * we check it without locking here to avoid unnecessary
1435                  * dqget()/dqput() calls.
1436                  */
1437                 if (dquots[cnt])
1438                         continue;
1439
1440                 if (!sb_has_quota_active(sb, cnt))
1441                         continue;
1442
1443                 init_needed = 1;
1444
1445                 switch (cnt) {
1446                 case USRQUOTA:
1447                         qid = make_kqid_uid(inode->i_uid);
1448                         break;
1449                 case GRPQUOTA:
1450                         qid = make_kqid_gid(inode->i_gid);
1451                         break;
1452                 case PRJQUOTA:
1453                         rc = inode->i_sb->dq_op->get_projid(inode, &projid);
1454                         if (rc)
1455                                 continue;
1456                         qid = make_kqid_projid(projid);
1457                         break;
1458                 }
1459                 dquot = dqget(sb, qid);
1460                 if (IS_ERR(dquot)) {
1461                         /* We raced with somebody turning quotas off... */
1462                         if (PTR_ERR(dquot) != -ESRCH) {
1463                                 ret = PTR_ERR(dquot);
1464                                 goto out_put;
1465                         }
1466                         dquot = NULL;
1467                 }
1468                 got[cnt] = dquot;
1469         }
1470
1471         /* All required i_dquot has been initialized */
1472         if (!init_needed)
1473                 return 0;
1474
1475         spin_lock(&dq_data_lock);
1476         if (IS_NOQUOTA(inode))
1477                 goto out_lock;
1478         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1479                 if (type != -1 && cnt != type)
1480                         continue;
1481                 /* Avoid races with quotaoff() */
1482                 if (!sb_has_quota_active(sb, cnt))
1483                         continue;
1484                 /* We could race with quotaon or dqget() could have failed */
1485                 if (!got[cnt])
1486                         continue;
1487                 if (!dquots[cnt]) {
1488                         dquots[cnt] = got[cnt];
1489                         got[cnt] = NULL;
1490                         /*
1491                          * Make quota reservation system happy if someone
1492                          * did a write before quota was turned on
1493                          */
1494                         rsv = inode_get_rsv_space(inode);
1495                         if (unlikely(rsv))
1496                                 dquot_resv_space(dquots[cnt], rsv);
1497                 }
1498         }
1499 out_lock:
1500         spin_unlock(&dq_data_lock);
1501 out_put:
1502         /* Drop unused references */
1503         dqput_all(got);
1504
1505         return ret;
1506 }
1507
1508 int dquot_initialize(struct inode *inode)
1509 {
1510         return __dquot_initialize(inode, -1);
1511 }
1512 EXPORT_SYMBOL(dquot_initialize);
1513
1514 /*
1515  * Release all quotas referenced by inode.
1516  *
1517  * This function only be called on inode free or converting
1518  * a file to quota file, no other users for the i_dquot in
1519  * both cases, so we needn't call synchronize_srcu() after
1520  * clearing i_dquot.
1521  */
1522 static void __dquot_drop(struct inode *inode)
1523 {
1524         int cnt;
1525         struct dquot **dquots = i_dquot(inode);
1526         struct dquot *put[MAXQUOTAS];
1527
1528         spin_lock(&dq_data_lock);
1529         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1530                 put[cnt] = dquots[cnt];
1531                 dquots[cnt] = NULL;
1532         }
1533         spin_unlock(&dq_data_lock);
1534         dqput_all(put);
1535 }
1536
1537 void dquot_drop(struct inode *inode)
1538 {
1539         struct dquot * const *dquots;
1540         int cnt;
1541
1542         if (IS_NOQUOTA(inode))
1543                 return;
1544
1545         /*
1546          * Test before calling to rule out calls from proc and such
1547          * where we are not allowed to block. Note that this is
1548          * actually reliable test even without the lock - the caller
1549          * must assure that nobody can come after the DQUOT_DROP and
1550          * add quota pointers back anyway.
1551          */
1552         dquots = i_dquot(inode);
1553         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1554                 if (dquots[cnt])
1555                         break;
1556         }
1557
1558         if (cnt < MAXQUOTAS)
1559                 __dquot_drop(inode);
1560 }
1561 EXPORT_SYMBOL(dquot_drop);
1562
1563 /*
1564  * inode_reserved_space is managed internally by quota, and protected by
1565  * i_lock similar to i_blocks+i_bytes.
1566  */
1567 static qsize_t *inode_reserved_space(struct inode * inode)
1568 {
1569         /* Filesystem must explicitly define it's own method in order to use
1570          * quota reservation interface */
1571         BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1572         return inode->i_sb->dq_op->get_reserved_space(inode);
1573 }
1574
1575 void inode_add_rsv_space(struct inode *inode, qsize_t number)
1576 {
1577         spin_lock(&inode->i_lock);
1578         *inode_reserved_space(inode) += number;
1579         spin_unlock(&inode->i_lock);
1580 }
1581 EXPORT_SYMBOL(inode_add_rsv_space);
1582
1583 void inode_claim_rsv_space(struct inode *inode, qsize_t number)
1584 {
1585         spin_lock(&inode->i_lock);
1586         *inode_reserved_space(inode) -= number;
1587         __inode_add_bytes(inode, number);
1588         spin_unlock(&inode->i_lock);
1589 }
1590 EXPORT_SYMBOL(inode_claim_rsv_space);
1591
1592 void inode_reclaim_rsv_space(struct inode *inode, qsize_t number)
1593 {
1594         spin_lock(&inode->i_lock);
1595         *inode_reserved_space(inode) += number;
1596         __inode_sub_bytes(inode, number);
1597         spin_unlock(&inode->i_lock);
1598 }
1599 EXPORT_SYMBOL(inode_reclaim_rsv_space);
1600
1601 void inode_sub_rsv_space(struct inode *inode, qsize_t number)
1602 {
1603         spin_lock(&inode->i_lock);
1604         *inode_reserved_space(inode) -= number;
1605         spin_unlock(&inode->i_lock);
1606 }
1607 EXPORT_SYMBOL(inode_sub_rsv_space);
1608
1609 static qsize_t inode_get_rsv_space(struct inode *inode)
1610 {
1611         qsize_t ret;
1612
1613         if (!inode->i_sb->dq_op->get_reserved_space)
1614                 return 0;
1615         spin_lock(&inode->i_lock);
1616         ret = *inode_reserved_space(inode);
1617         spin_unlock(&inode->i_lock);
1618         return ret;
1619 }
1620
1621 static void inode_incr_space(struct inode *inode, qsize_t number,
1622                                 int reserve)
1623 {
1624         if (reserve)
1625                 inode_add_rsv_space(inode, number);
1626         else
1627                 inode_add_bytes(inode, number);
1628 }
1629
1630 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve)
1631 {
1632         if (reserve)
1633                 inode_sub_rsv_space(inode, number);
1634         else
1635                 inode_sub_bytes(inode, number);
1636 }
1637
1638 /*
1639  * This functions updates i_blocks+i_bytes fields and quota information
1640  * (together with appropriate checks).
1641  *
1642  * NOTE: We absolutely rely on the fact that caller dirties the inode
1643  * (usually helpers in quotaops.h care about this) and holds a handle for
1644  * the current transaction so that dquot write and inode write go into the
1645  * same transaction.
1646  */
1647
1648 /*
1649  * This operation can block, but only after everything is updated
1650  */
1651 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
1652 {
1653         int cnt, ret = 0, index;
1654         struct dquot_warn warn[MAXQUOTAS];
1655         int reserve = flags & DQUOT_SPACE_RESERVE;
1656         struct dquot **dquots;
1657
1658         if (!dquot_active(inode)) {
1659                 inode_incr_space(inode, number, reserve);
1660                 goto out;
1661         }
1662
1663         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1664                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1665
1666         dquots = i_dquot(inode);
1667         index = srcu_read_lock(&dquot_srcu);
1668         spin_lock(&dq_data_lock);
1669         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1670                 if (!dquots[cnt])
1671                         continue;
1672                 ret = check_bdq(dquots[cnt], number,
1673                                 !(flags & DQUOT_SPACE_WARN), &warn[cnt]);
1674                 if (ret && !(flags & DQUOT_SPACE_NOFAIL)) {
1675                         spin_unlock(&dq_data_lock);
1676                         goto out_flush_warn;
1677                 }
1678         }
1679         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1680                 if (!dquots[cnt])
1681                         continue;
1682                 if (reserve)
1683                         dquot_resv_space(dquots[cnt], number);
1684                 else
1685                         dquot_incr_space(dquots[cnt], number);
1686         }
1687         inode_incr_space(inode, number, reserve);
1688         spin_unlock(&dq_data_lock);
1689
1690         if (reserve)
1691                 goto out_flush_warn;
1692         mark_all_dquot_dirty(dquots);
1693 out_flush_warn:
1694         srcu_read_unlock(&dquot_srcu, index);
1695         flush_warnings(warn);
1696 out:
1697         return ret;
1698 }
1699 EXPORT_SYMBOL(__dquot_alloc_space);
1700
1701 /*
1702  * This operation can block, but only after everything is updated
1703  */
1704 int dquot_alloc_inode(struct inode *inode)
1705 {
1706         int cnt, ret = 0, index;
1707         struct dquot_warn warn[MAXQUOTAS];
1708         struct dquot * const *dquots;
1709
1710         if (!dquot_active(inode))
1711                 return 0;
1712         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1713                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1714
1715         dquots = i_dquot(inode);
1716         index = srcu_read_lock(&dquot_srcu);
1717         spin_lock(&dq_data_lock);
1718         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1719                 if (!dquots[cnt])
1720                         continue;
1721                 ret = check_idq(dquots[cnt], 1, &warn[cnt]);
1722                 if (ret)
1723                         goto warn_put_all;
1724         }
1725
1726         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1727                 if (!dquots[cnt])
1728                         continue;
1729                 dquot_incr_inodes(dquots[cnt], 1);
1730         }
1731
1732 warn_put_all:
1733         spin_unlock(&dq_data_lock);
1734         if (ret == 0)
1735                 mark_all_dquot_dirty(dquots);
1736         srcu_read_unlock(&dquot_srcu, index);
1737         flush_warnings(warn);
1738         return ret;
1739 }
1740 EXPORT_SYMBOL(dquot_alloc_inode);
1741
1742 /*
1743  * Convert in-memory reserved quotas to real consumed quotas
1744  */
1745 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
1746 {
1747         struct dquot **dquots;
1748         int cnt, index;
1749
1750         if (!dquot_active(inode)) {
1751                 inode_claim_rsv_space(inode, number);
1752                 return 0;
1753         }
1754
1755         dquots = i_dquot(inode);
1756         index = srcu_read_lock(&dquot_srcu);
1757         spin_lock(&dq_data_lock);
1758         /* Claim reserved quotas to allocated quotas */
1759         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1760                 if (dquots[cnt])
1761                         dquot_claim_reserved_space(dquots[cnt], number);
1762         }
1763         /* Update inode bytes */
1764         inode_claim_rsv_space(inode, number);
1765         spin_unlock(&dq_data_lock);
1766         mark_all_dquot_dirty(dquots);
1767         srcu_read_unlock(&dquot_srcu, index);
1768         return 0;
1769 }
1770 EXPORT_SYMBOL(dquot_claim_space_nodirty);
1771
1772 /*
1773  * Convert allocated space back to in-memory reserved quotas
1774  */
1775 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number)
1776 {
1777         struct dquot **dquots;
1778         int cnt, index;
1779
1780         if (!dquot_active(inode)) {
1781                 inode_reclaim_rsv_space(inode, number);
1782                 return;
1783         }
1784
1785         dquots = i_dquot(inode);
1786         index = srcu_read_lock(&dquot_srcu);
1787         spin_lock(&dq_data_lock);
1788         /* Claim reserved quotas to allocated quotas */
1789         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1790                 if (dquots[cnt])
1791                         dquot_reclaim_reserved_space(dquots[cnt], number);
1792         }
1793         /* Update inode bytes */
1794         inode_reclaim_rsv_space(inode, number);
1795         spin_unlock(&dq_data_lock);
1796         mark_all_dquot_dirty(dquots);
1797         srcu_read_unlock(&dquot_srcu, index);
1798         return;
1799 }
1800 EXPORT_SYMBOL(dquot_reclaim_space_nodirty);
1801
1802 /*
1803  * This operation can block, but only after everything is updated
1804  */
1805 void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
1806 {
1807         unsigned int cnt;
1808         struct dquot_warn warn[MAXQUOTAS];
1809         struct dquot **dquots;
1810         int reserve = flags & DQUOT_SPACE_RESERVE, index;
1811
1812         if (!dquot_active(inode)) {
1813                 inode_decr_space(inode, number, reserve);
1814                 return;
1815         }
1816
1817         dquots = i_dquot(inode);
1818         index = srcu_read_lock(&dquot_srcu);
1819         spin_lock(&dq_data_lock);
1820         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1821                 int wtype;
1822
1823                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1824                 if (!dquots[cnt])
1825                         continue;
1826                 wtype = info_bdq_free(dquots[cnt], number);
1827                 if (wtype != QUOTA_NL_NOWARN)
1828                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1829                 if (reserve)
1830                         dquot_free_reserved_space(dquots[cnt], number);
1831                 else
1832                         dquot_decr_space(dquots[cnt], number);
1833         }
1834         inode_decr_space(inode, number, reserve);
1835         spin_unlock(&dq_data_lock);
1836
1837         if (reserve)
1838                 goto out_unlock;
1839         mark_all_dquot_dirty(dquots);
1840 out_unlock:
1841         srcu_read_unlock(&dquot_srcu, index);
1842         flush_warnings(warn);
1843 }
1844 EXPORT_SYMBOL(__dquot_free_space);
1845
1846 /*
1847  * This operation can block, but only after everything is updated
1848  */
1849 void dquot_free_inode(struct inode *inode)
1850 {
1851         unsigned int cnt;
1852         struct dquot_warn warn[MAXQUOTAS];
1853         struct dquot * const *dquots;
1854         int index;
1855
1856         if (!dquot_active(inode))
1857                 return;
1858
1859         dquots = i_dquot(inode);
1860         index = srcu_read_lock(&dquot_srcu);
1861         spin_lock(&dq_data_lock);
1862         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1863                 int wtype;
1864
1865                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1866                 if (!dquots[cnt])
1867                         continue;
1868                 wtype = info_idq_free(dquots[cnt], 1);
1869                 if (wtype != QUOTA_NL_NOWARN)
1870                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1871                 dquot_decr_inodes(dquots[cnt], 1);
1872         }
1873         spin_unlock(&dq_data_lock);
1874         mark_all_dquot_dirty(dquots);
1875         srcu_read_unlock(&dquot_srcu, index);
1876         flush_warnings(warn);
1877 }
1878 EXPORT_SYMBOL(dquot_free_inode);
1879
1880 /*
1881  * Transfer the number of inode and blocks from one diskquota to an other.
1882  * On success, dquot references in transfer_to are consumed and references
1883  * to original dquots that need to be released are placed there. On failure,
1884  * references are kept untouched.
1885  *
1886  * This operation can block, but only after everything is updated
1887  * A transaction must be started when entering this function.
1888  *
1889  * We are holding reference on transfer_from & transfer_to, no need to
1890  * protect them by srcu_read_lock().
1891  */
1892 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
1893 {
1894         qsize_t space, cur_space;
1895         qsize_t rsv_space = 0;
1896         struct dquot *transfer_from[MAXQUOTAS] = {};
1897         int cnt, ret = 0;
1898         char is_valid[MAXQUOTAS] = {};
1899         struct dquot_warn warn_to[MAXQUOTAS];
1900         struct dquot_warn warn_from_inodes[MAXQUOTAS];
1901         struct dquot_warn warn_from_space[MAXQUOTAS];
1902
1903         if (IS_NOQUOTA(inode))
1904                 return 0;
1905         /* Initialize the arrays */
1906         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1907                 warn_to[cnt].w_type = QUOTA_NL_NOWARN;
1908                 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN;
1909                 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN;
1910         }
1911
1912         spin_lock(&dq_data_lock);
1913         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1914                 spin_unlock(&dq_data_lock);
1915                 return 0;
1916         }
1917         cur_space = inode_get_bytes(inode);
1918         rsv_space = inode_get_rsv_space(inode);
1919         space = cur_space + rsv_space;
1920         /* Build the transfer_from list and check the limits */
1921         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1922                 /*
1923                  * Skip changes for same uid or gid or for turned off quota-type.
1924                  */
1925                 if (!transfer_to[cnt])
1926                         continue;
1927                 /* Avoid races with quotaoff() */
1928                 if (!sb_has_quota_active(inode->i_sb, cnt))
1929                         continue;
1930                 is_valid[cnt] = 1;
1931                 transfer_from[cnt] = i_dquot(inode)[cnt];
1932                 ret = check_idq(transfer_to[cnt], 1, &warn_to[cnt]);
1933                 if (ret)
1934                         goto over_quota;
1935                 ret = check_bdq(transfer_to[cnt], space, 0, &warn_to[cnt]);
1936                 if (ret)
1937                         goto over_quota;
1938         }
1939
1940         /*
1941          * Finally perform the needed transfer from transfer_from to transfer_to
1942          */
1943         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1944                 if (!is_valid[cnt])
1945                         continue;
1946                 /* Due to IO error we might not have transfer_from[] structure */
1947                 if (transfer_from[cnt]) {
1948                         int wtype;
1949                         wtype = info_idq_free(transfer_from[cnt], 1);
1950                         if (wtype != QUOTA_NL_NOWARN)
1951                                 prepare_warning(&warn_from_inodes[cnt],
1952                                                 transfer_from[cnt], wtype);
1953                         wtype = info_bdq_free(transfer_from[cnt], space);
1954                         if (wtype != QUOTA_NL_NOWARN)
1955                                 prepare_warning(&warn_from_space[cnt],
1956                                                 transfer_from[cnt], wtype);
1957                         dquot_decr_inodes(transfer_from[cnt], 1);
1958                         dquot_decr_space(transfer_from[cnt], cur_space);
1959                         dquot_free_reserved_space(transfer_from[cnt],
1960                                                   rsv_space);
1961                 }
1962
1963                 dquot_incr_inodes(transfer_to[cnt], 1);
1964                 dquot_incr_space(transfer_to[cnt], cur_space);
1965                 dquot_resv_space(transfer_to[cnt], rsv_space);
1966
1967                 i_dquot(inode)[cnt] = transfer_to[cnt];
1968         }
1969         spin_unlock(&dq_data_lock);
1970
1971         mark_all_dquot_dirty(transfer_from);
1972         mark_all_dquot_dirty(transfer_to);
1973         flush_warnings(warn_to);
1974         flush_warnings(warn_from_inodes);
1975         flush_warnings(warn_from_space);
1976         /* Pass back references to put */
1977         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1978                 if (is_valid[cnt])
1979                         transfer_to[cnt] = transfer_from[cnt];
1980         return 0;
1981 over_quota:
1982         spin_unlock(&dq_data_lock);
1983         flush_warnings(warn_to);
1984         return ret;
1985 }
1986 EXPORT_SYMBOL(__dquot_transfer);
1987
1988 /* Wrapper for transferring ownership of an inode for uid/gid only
1989  * Called from FSXXX_setattr()
1990  */
1991 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1992 {
1993         struct dquot *transfer_to[MAXQUOTAS] = {};
1994         struct dquot *dquot;
1995         struct super_block *sb = inode->i_sb;
1996         int ret;
1997
1998         if (!dquot_active(inode))
1999                 return 0;
2000
2001         if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){
2002                 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid));
2003                 if (IS_ERR(dquot)) {
2004                         if (PTR_ERR(dquot) != -ESRCH) {
2005                                 ret = PTR_ERR(dquot);
2006                                 goto out_put;
2007                         }
2008                         dquot = NULL;
2009                 }
2010                 transfer_to[USRQUOTA] = dquot;
2011         }
2012         if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){
2013                 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid));
2014                 if (IS_ERR(dquot)) {
2015                         if (PTR_ERR(dquot) != -ESRCH) {
2016                                 ret = PTR_ERR(dquot);
2017                                 goto out_put;
2018                         }
2019                         dquot = NULL;
2020                 }
2021                 transfer_to[GRPQUOTA] = dquot;
2022         }
2023         ret = __dquot_transfer(inode, transfer_to);
2024 out_put:
2025         dqput_all(transfer_to);
2026         return ret;
2027 }
2028 EXPORT_SYMBOL(dquot_transfer);
2029
2030 /*
2031  * Write info of quota file to disk
2032  */
2033 int dquot_commit_info(struct super_block *sb, int type)
2034 {
2035         int ret;
2036         struct quota_info *dqopt = sb_dqopt(sb);
2037
2038         mutex_lock(&dqopt->dqio_mutex);
2039         ret = dqopt->ops[type]->write_file_info(sb, type);
2040         mutex_unlock(&dqopt->dqio_mutex);
2041         return ret;
2042 }
2043 EXPORT_SYMBOL(dquot_commit_info);
2044
2045 int dquot_get_next_id(struct super_block *sb, struct kqid *qid)
2046 {
2047         struct quota_info *dqopt = sb_dqopt(sb);
2048         int err;
2049
2050         if (!sb_has_quota_active(sb, qid->type))
2051                 return -ESRCH;
2052         if (!dqopt->ops[qid->type]->get_next_id)
2053                 return -ENOSYS;
2054         mutex_lock(&dqopt->dqio_mutex);
2055         err = dqopt->ops[qid->type]->get_next_id(sb, qid);
2056         mutex_unlock(&dqopt->dqio_mutex);
2057         return err;
2058 }
2059 EXPORT_SYMBOL(dquot_get_next_id);
2060
2061 /*
2062  * Definitions of diskquota operations.
2063  */
2064 const struct dquot_operations dquot_operations = {
2065         .write_dquot    = dquot_commit,
2066         .acquire_dquot  = dquot_acquire,
2067         .release_dquot  = dquot_release,
2068         .mark_dirty     = dquot_mark_dquot_dirty,
2069         .write_info     = dquot_commit_info,
2070         .alloc_dquot    = dquot_alloc,
2071         .destroy_dquot  = dquot_destroy,
2072         .get_next_id    = dquot_get_next_id,
2073 };
2074 EXPORT_SYMBOL(dquot_operations);
2075
2076 /*
2077  * Generic helper for ->open on filesystems supporting disk quotas.
2078  */
2079 int dquot_file_open(struct inode *inode, struct file *file)
2080 {
2081         int error;
2082
2083         error = generic_file_open(inode, file);
2084         if (!error && (file->f_mode & FMODE_WRITE))
2085                 dquot_initialize(inode);
2086         return error;
2087 }
2088 EXPORT_SYMBOL(dquot_file_open);
2089
2090 /*
2091  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
2092  */
2093 int dquot_disable(struct super_block *sb, int type, unsigned int flags)
2094 {
2095         int cnt, ret = 0;
2096         struct quota_info *dqopt = sb_dqopt(sb);
2097         struct inode *toputinode[MAXQUOTAS];
2098
2099         /* s_umount should be held in exclusive mode */
2100         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2101                 up_read(&sb->s_umount);
2102
2103         /* Cannot turn off usage accounting without turning off limits, or
2104          * suspend quotas and simultaneously turn quotas off. */
2105         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
2106             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
2107             DQUOT_USAGE_ENABLED)))
2108                 return -EINVAL;
2109
2110         /*
2111          * Skip everything if there's nothing to do. We have to do this because
2112          * sometimes we are called when fill_super() failed and calling
2113          * sync_fs() in such cases does no good.
2114          */
2115         if (!sb_any_quota_loaded(sb))
2116                 return 0;
2117
2118         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2119                 toputinode[cnt] = NULL;
2120                 if (type != -1 && cnt != type)
2121                         continue;
2122                 if (!sb_has_quota_loaded(sb, cnt))
2123                         continue;
2124
2125                 if (flags & DQUOT_SUSPENDED) {
2126                         spin_lock(&dq_state_lock);
2127                         dqopt->flags |=
2128                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
2129                         spin_unlock(&dq_state_lock);
2130                 } else {
2131                         spin_lock(&dq_state_lock);
2132                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
2133                         /* Turning off suspended quotas? */
2134                         if (!sb_has_quota_loaded(sb, cnt) &&
2135                             sb_has_quota_suspended(sb, cnt)) {
2136                                 dqopt->flags &= ~dquot_state_flag(
2137                                                         DQUOT_SUSPENDED, cnt);
2138                                 spin_unlock(&dq_state_lock);
2139                                 iput(dqopt->files[cnt]);
2140                                 dqopt->files[cnt] = NULL;
2141                                 continue;
2142                         }
2143                         spin_unlock(&dq_state_lock);
2144                 }
2145
2146                 /* We still have to keep quota loaded? */
2147                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
2148                         continue;
2149
2150                 /* Note: these are blocking operations */
2151                 drop_dquot_ref(sb, cnt);
2152                 invalidate_dquots(sb, cnt);
2153                 /*
2154                  * Now all dquots should be invalidated, all writes done so we
2155                  * should be only users of the info. No locks needed.
2156                  */
2157                 if (info_dirty(&dqopt->info[cnt]))
2158                         sb->dq_op->write_info(sb, cnt);
2159                 if (dqopt->ops[cnt]->free_file_info)
2160                         dqopt->ops[cnt]->free_file_info(sb, cnt);
2161                 put_quota_format(dqopt->info[cnt].dqi_format);
2162
2163                 toputinode[cnt] = dqopt->files[cnt];
2164                 if (!sb_has_quota_loaded(sb, cnt))
2165                         dqopt->files[cnt] = NULL;
2166                 dqopt->info[cnt].dqi_flags = 0;
2167                 dqopt->info[cnt].dqi_igrace = 0;
2168                 dqopt->info[cnt].dqi_bgrace = 0;
2169                 dqopt->ops[cnt] = NULL;
2170         }
2171
2172         /* Skip syncing and setting flags if quota files are hidden */
2173         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
2174                 goto put_inodes;
2175
2176         /* Sync the superblock so that buffers with quota data are written to
2177          * disk (and so userspace sees correct data afterwards). */
2178         if (sb->s_op->sync_fs)
2179                 sb->s_op->sync_fs(sb, 1);
2180         sync_blockdev(sb->s_bdev);
2181         /* Now the quota files are just ordinary files and we can set the
2182          * inode flags back. Moreover we discard the pagecache so that
2183          * userspace sees the writes we did bypassing the pagecache. We
2184          * must also discard the blockdev buffers so that we see the
2185          * changes done by userspace on the next quotaon() */
2186         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2187                 /* This can happen when suspending quotas on remount-ro... */
2188                 if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) {
2189                         inode_lock(toputinode[cnt]);
2190                         toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
2191                                   S_NOATIME | S_NOQUOTA);
2192                         truncate_inode_pages(&toputinode[cnt]->i_data, 0);
2193                         inode_unlock(toputinode[cnt]);
2194                         mark_inode_dirty_sync(toputinode[cnt]);
2195                 }
2196         if (sb->s_bdev)
2197                 invalidate_bdev(sb->s_bdev);
2198 put_inodes:
2199         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2200                 if (toputinode[cnt]) {
2201                         /* On remount RO, we keep the inode pointer so that we
2202                          * can reenable quota on the subsequent remount RW. We
2203                          * have to check 'flags' variable and not use sb_has_
2204                          * function because another quotaon / quotaoff could
2205                          * change global state before we got here. We refuse
2206                          * to suspend quotas when there is pending delete on
2207                          * the quota file... */
2208                         if (!(flags & DQUOT_SUSPENDED))
2209                                 iput(toputinode[cnt]);
2210                         else if (!toputinode[cnt]->i_nlink)
2211                                 ret = -EBUSY;
2212                 }
2213         return ret;
2214 }
2215 EXPORT_SYMBOL(dquot_disable);
2216
2217 int dquot_quota_off(struct super_block *sb, int type)
2218 {
2219         return dquot_disable(sb, type,
2220                              DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2221 }
2222 EXPORT_SYMBOL(dquot_quota_off);
2223
2224 /*
2225  *      Turn quotas on on a device
2226  */
2227
2228 /*
2229  * Helper function to turn quotas on when we already have the inode of
2230  * quota file and no quota information is loaded.
2231  */
2232 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2233         unsigned int flags)
2234 {
2235         struct quota_format_type *fmt = find_quota_format(format_id);
2236         struct super_block *sb = inode->i_sb;
2237         struct quota_info *dqopt = sb_dqopt(sb);
2238         int error;
2239         int oldflags = -1;
2240
2241         if (!fmt)
2242                 return -ESRCH;
2243         if (!S_ISREG(inode->i_mode)) {
2244                 error = -EACCES;
2245                 goto out_fmt;
2246         }
2247         if (IS_RDONLY(inode)) {
2248                 error = -EROFS;
2249                 goto out_fmt;
2250         }
2251         if (!sb->s_op->quota_write || !sb->s_op->quota_read ||
2252             (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) {
2253                 error = -EINVAL;
2254                 goto out_fmt;
2255         }
2256         /* Filesystems outside of init_user_ns not yet supported */
2257         if (sb->s_user_ns != &init_user_ns) {
2258                 error = -EINVAL;
2259                 goto out_fmt;
2260         }
2261         /* Usage always has to be set... */
2262         if (!(flags & DQUOT_USAGE_ENABLED)) {
2263                 error = -EINVAL;
2264                 goto out_fmt;
2265         }
2266         if (sb_has_quota_loaded(sb, type)) {
2267                 error = -EBUSY;
2268                 goto out_fmt;
2269         }
2270
2271         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2272                 /* As we bypass the pagecache we must now flush all the
2273                  * dirty data and invalidate caches so that kernel sees
2274                  * changes from userspace. It is not enough to just flush
2275                  * the quota file since if blocksize < pagesize, invalidation
2276                  * of the cache could fail because of other unrelated dirty
2277                  * data */
2278                 sync_filesystem(sb);
2279                 invalidate_bdev(sb->s_bdev);
2280         }
2281
2282         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2283                 /* We don't want quota and atime on quota files (deadlocks
2284                  * possible) Also nobody should write to the file - we use
2285                  * special IO operations which ignore the immutable bit. */
2286                 inode_lock(inode);
2287                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2288                                              S_NOQUOTA);
2289                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2290                 inode_unlock(inode);
2291                 /*
2292                  * When S_NOQUOTA is set, remove dquot references as no more
2293                  * references can be added
2294                  */
2295                 __dquot_drop(inode);
2296         }
2297
2298         error = -EIO;
2299         dqopt->files[type] = igrab(inode);
2300         if (!dqopt->files[type])
2301                 goto out_file_flags;
2302         error = -EINVAL;
2303         if (!fmt->qf_ops->check_quota_file(sb, type))
2304                 goto out_file_init;
2305
2306         dqopt->ops[type] = fmt->qf_ops;
2307         dqopt->info[type].dqi_format = fmt;
2308         dqopt->info[type].dqi_fmt_id = format_id;
2309         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2310         mutex_lock(&dqopt->dqio_mutex);
2311         error = dqopt->ops[type]->read_file_info(sb, type);
2312         if (error < 0) {
2313                 mutex_unlock(&dqopt->dqio_mutex);
2314                 goto out_file_init;
2315         }
2316         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
2317                 dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
2318         mutex_unlock(&dqopt->dqio_mutex);
2319         spin_lock(&dq_state_lock);
2320         dqopt->flags |= dquot_state_flag(flags, type);
2321         spin_unlock(&dq_state_lock);
2322
2323         add_dquot_ref(sb, type);
2324
2325         return 0;
2326
2327 out_file_init:
2328         dqopt->files[type] = NULL;
2329         iput(inode);
2330 out_file_flags:
2331         if (oldflags != -1) {
2332                 inode_lock(inode);
2333                 /* Set the flags back (in the case of accidental quotaon()
2334                  * on a wrong file we don't want to mess up the flags) */
2335                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2336                 inode->i_flags |= oldflags;
2337                 inode_unlock(inode);
2338         }
2339 out_fmt:
2340         put_quota_format(fmt);
2341
2342         return error; 
2343 }
2344
2345 /* Reenable quotas on remount RW */
2346 int dquot_resume(struct super_block *sb, int type)
2347 {
2348         struct quota_info *dqopt = sb_dqopt(sb);
2349         struct inode *inode;
2350         int ret = 0, cnt;
2351         unsigned int flags;
2352
2353         /* s_umount should be held in exclusive mode */
2354         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2355                 up_read(&sb->s_umount);
2356
2357         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2358                 if (type != -1 && cnt != type)
2359                         continue;
2360                 if (!sb_has_quota_suspended(sb, cnt))
2361                         continue;
2362
2363                 inode = dqopt->files[cnt];
2364                 dqopt->files[cnt] = NULL;
2365                 spin_lock(&dq_state_lock);
2366                 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2367                                                         DQUOT_LIMITS_ENABLED,
2368                                                         cnt);
2369                 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
2370                 spin_unlock(&dq_state_lock);
2371
2372                 flags = dquot_generic_flag(flags, cnt);
2373                 ret = vfs_load_quota_inode(inode, cnt,
2374                                 dqopt->info[cnt].dqi_fmt_id, flags);
2375                 iput(inode);
2376         }
2377
2378         return ret;
2379 }
2380 EXPORT_SYMBOL(dquot_resume);
2381
2382 int dquot_quota_on(struct super_block *sb, int type, int format_id,
2383                    const struct path *path)
2384 {
2385         int error = security_quota_on(path->dentry);
2386         if (error)
2387                 return error;
2388         /* Quota file not on the same filesystem? */
2389         if (path->dentry->d_sb != sb)
2390                 error = -EXDEV;
2391         else
2392                 error = vfs_load_quota_inode(d_inode(path->dentry), type,
2393                                              format_id, DQUOT_USAGE_ENABLED |
2394                                              DQUOT_LIMITS_ENABLED);
2395         return error;
2396 }
2397 EXPORT_SYMBOL(dquot_quota_on);
2398
2399 /*
2400  * More powerful function for turning on quotas allowing setting
2401  * of individual quota flags
2402  */
2403 int dquot_enable(struct inode *inode, int type, int format_id,
2404                  unsigned int flags)
2405 {
2406         struct super_block *sb = inode->i_sb;
2407
2408         /* Just unsuspend quotas? */
2409         BUG_ON(flags & DQUOT_SUSPENDED);
2410         /* s_umount should be held in exclusive mode */
2411         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2412                 up_read(&sb->s_umount);
2413
2414         if (!flags)
2415                 return 0;
2416         /* Just updating flags needed? */
2417         if (sb_has_quota_loaded(sb, type)) {
2418                 if (flags & DQUOT_USAGE_ENABLED &&
2419                     sb_has_quota_usage_enabled(sb, type))
2420                         return -EBUSY;
2421                 if (flags & DQUOT_LIMITS_ENABLED &&
2422                     sb_has_quota_limits_enabled(sb, type))
2423                         return -EBUSY;
2424                 spin_lock(&dq_state_lock);
2425                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2426                 spin_unlock(&dq_state_lock);
2427                 return 0;
2428         }
2429
2430         return vfs_load_quota_inode(inode, type, format_id, flags);
2431 }
2432 EXPORT_SYMBOL(dquot_enable);
2433
2434 /*
2435  * This function is used when filesystem needs to initialize quotas
2436  * during mount time.
2437  */
2438 int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
2439                 int format_id, int type)
2440 {
2441         struct dentry *dentry;
2442         int error;
2443
2444         dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name));
2445         if (IS_ERR(dentry))
2446                 return PTR_ERR(dentry);
2447
2448         if (d_really_is_negative(dentry)) {
2449                 error = -ENOENT;
2450                 goto out;
2451         }
2452
2453         error = security_quota_on(dentry);
2454         if (!error)
2455                 error = vfs_load_quota_inode(d_inode(dentry), type, format_id,
2456                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2457
2458 out:
2459         dput(dentry);
2460         return error;
2461 }
2462 EXPORT_SYMBOL(dquot_quota_on_mount);
2463
2464 static int dquot_quota_enable(struct super_block *sb, unsigned int flags)
2465 {
2466         int ret;
2467         int type;
2468         struct quota_info *dqopt = sb_dqopt(sb);
2469
2470         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
2471                 return -ENOSYS;
2472         /* Accounting cannot be turned on while fs is mounted */
2473         flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT);
2474         if (!flags)
2475                 return -EINVAL;
2476         for (type = 0; type < MAXQUOTAS; type++) {
2477                 if (!(flags & qtype_enforce_flag(type)))
2478                         continue;
2479                 /* Can't enforce without accounting */
2480                 if (!sb_has_quota_usage_enabled(sb, type))
2481                         return -EINVAL;
2482                 ret = dquot_enable(dqopt->files[type], type,
2483                                    dqopt->info[type].dqi_fmt_id,
2484                                    DQUOT_LIMITS_ENABLED);
2485                 if (ret < 0)
2486                         goto out_err;
2487         }
2488         return 0;
2489 out_err:
2490         /* Backout enforcement enablement we already did */
2491         for (type--; type >= 0; type--)  {
2492                 if (flags & qtype_enforce_flag(type))
2493                         dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
2494         }
2495         /* Error code translation for better compatibility with XFS */
2496         if (ret == -EBUSY)
2497                 ret = -EEXIST;
2498         return ret;
2499 }
2500
2501 static int dquot_quota_disable(struct super_block *sb, unsigned int flags)
2502 {
2503         int ret;
2504         int type;
2505         struct quota_info *dqopt = sb_dqopt(sb);
2506
2507         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
2508                 return -ENOSYS;
2509         /*
2510          * We don't support turning off accounting via quotactl. In principle
2511          * quota infrastructure can do this but filesystems don't expect
2512          * userspace to be able to do it.
2513          */
2514         if (flags &
2515                   (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT))
2516                 return -EOPNOTSUPP;
2517
2518         /* Filter out limits not enabled */
2519         for (type = 0; type < MAXQUOTAS; type++)
2520                 if (!sb_has_quota_limits_enabled(sb, type))
2521                         flags &= ~qtype_enforce_flag(type);
2522         /* Nothing left? */
2523         if (!flags)
2524                 return -EEXIST;
2525         for (type = 0; type < MAXQUOTAS; type++) {
2526                 if (flags & qtype_enforce_flag(type)) {
2527                         ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
2528                         if (ret < 0)
2529                                 goto out_err;
2530                 }
2531         }
2532         return 0;
2533 out_err:
2534         /* Backout enforcement disabling we already did */
2535         for (type--; type >= 0; type--)  {
2536                 if (flags & qtype_enforce_flag(type))
2537                         dquot_enable(dqopt->files[type], type,
2538                                      dqopt->info[type].dqi_fmt_id,
2539                                      DQUOT_LIMITS_ENABLED);
2540         }
2541         return ret;
2542 }
2543
2544 /* Generic routine for getting common part of quota structure */
2545 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di)
2546 {
2547         struct mem_dqblk *dm = &dquot->dq_dqb;
2548
2549         memset(di, 0, sizeof(*di));
2550         spin_lock(&dq_data_lock);
2551         di->d_spc_hardlimit = dm->dqb_bhardlimit;
2552         di->d_spc_softlimit = dm->dqb_bsoftlimit;
2553         di->d_ino_hardlimit = dm->dqb_ihardlimit;
2554         di->d_ino_softlimit = dm->dqb_isoftlimit;
2555         di->d_space = dm->dqb_curspace + dm->dqb_rsvspace;
2556         di->d_ino_count = dm->dqb_curinodes;
2557         di->d_spc_timer = dm->dqb_btime;
2558         di->d_ino_timer = dm->dqb_itime;
2559         spin_unlock(&dq_data_lock);
2560 }
2561
2562 int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
2563                     struct qc_dqblk *di)
2564 {
2565         struct dquot *dquot;
2566
2567         dquot = dqget(sb, qid);
2568         if (IS_ERR(dquot))
2569                 return PTR_ERR(dquot);
2570         do_get_dqblk(dquot, di);
2571         dqput(dquot);
2572
2573         return 0;
2574 }
2575 EXPORT_SYMBOL(dquot_get_dqblk);
2576
2577 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid,
2578                          struct qc_dqblk *di)
2579 {
2580         struct dquot *dquot;
2581         int err;
2582
2583         if (!sb->dq_op->get_next_id)
2584                 return -ENOSYS;
2585         err = sb->dq_op->get_next_id(sb, qid);
2586         if (err < 0)
2587                 return err;
2588         dquot = dqget(sb, *qid);
2589         if (IS_ERR(dquot))
2590                 return PTR_ERR(dquot);
2591         do_get_dqblk(dquot, di);
2592         dqput(dquot);
2593
2594         return 0;
2595 }
2596 EXPORT_SYMBOL(dquot_get_next_dqblk);
2597
2598 #define VFS_QC_MASK \
2599         (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \
2600          QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \
2601          QC_SPC_TIMER | QC_INO_TIMER)
2602
2603 /* Generic routine for setting common part of quota structure */
2604 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di)
2605 {
2606         struct mem_dqblk *dm = &dquot->dq_dqb;
2607         int check_blim = 0, check_ilim = 0;
2608         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
2609
2610         if (di->d_fieldmask & ~VFS_QC_MASK)
2611                 return -EINVAL;
2612
2613         if (((di->d_fieldmask & QC_SPC_SOFT) &&
2614              di->d_spc_softlimit > dqi->dqi_max_spc_limit) ||
2615             ((di->d_fieldmask & QC_SPC_HARD) &&
2616              di->d_spc_hardlimit > dqi->dqi_max_spc_limit) ||
2617             ((di->d_fieldmask & QC_INO_SOFT) &&
2618              (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) ||
2619             ((di->d_fieldmask & QC_INO_HARD) &&
2620              (di->d_ino_hardlimit > dqi->dqi_max_ino_limit)))
2621                 return -ERANGE;
2622
2623         spin_lock(&dq_data_lock);
2624         if (di->d_fieldmask & QC_SPACE) {
2625                 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace;
2626                 check_blim = 1;
2627                 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2628         }
2629
2630         if (di->d_fieldmask & QC_SPC_SOFT)
2631                 dm->dqb_bsoftlimit = di->d_spc_softlimit;
2632         if (di->d_fieldmask & QC_SPC_HARD)
2633                 dm->dqb_bhardlimit = di->d_spc_hardlimit;
2634         if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) {
2635                 check_blim = 1;
2636                 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2637         }
2638
2639         if (di->d_fieldmask & QC_INO_COUNT) {
2640                 dm->dqb_curinodes = di->d_ino_count;
2641                 check_ilim = 1;
2642                 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2643         }
2644
2645         if (di->d_fieldmask & QC_INO_SOFT)
2646                 dm->dqb_isoftlimit = di->d_ino_softlimit;
2647         if (di->d_fieldmask & QC_INO_HARD)
2648                 dm->dqb_ihardlimit = di->d_ino_hardlimit;
2649         if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) {
2650                 check_ilim = 1;
2651                 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2652         }
2653
2654         if (di->d_fieldmask & QC_SPC_TIMER) {
2655                 dm->dqb_btime = di->d_spc_timer;
2656                 check_blim = 1;
2657                 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2658         }
2659
2660         if (di->d_fieldmask & QC_INO_TIMER) {
2661                 dm->dqb_itime = di->d_ino_timer;
2662                 check_ilim = 1;
2663                 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2664         }
2665
2666         if (check_blim) {
2667                 if (!dm->dqb_bsoftlimit ||
2668                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2669                         dm->dqb_btime = 0;
2670                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2671                 } else if (!(di->d_fieldmask & QC_SPC_TIMER))
2672                         /* Set grace only if user hasn't provided his own... */
2673                         dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace;
2674         }
2675         if (check_ilim) {
2676                 if (!dm->dqb_isoftlimit ||
2677                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2678                         dm->dqb_itime = 0;
2679                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2680                 } else if (!(di->d_fieldmask & QC_INO_TIMER))
2681                         /* Set grace only if user hasn't provided his own... */
2682                         dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace;
2683         }
2684         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2685             dm->dqb_isoftlimit)
2686                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2687         else
2688                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2689         spin_unlock(&dq_data_lock);
2690         mark_dquot_dirty(dquot);
2691
2692         return 0;
2693 }
2694
2695 int dquot_set_dqblk(struct super_block *sb, struct kqid qid,
2696                   struct qc_dqblk *di)
2697 {
2698         struct dquot *dquot;
2699         int rc;
2700
2701         dquot = dqget(sb, qid);
2702         if (IS_ERR(dquot)) {
2703                 rc = PTR_ERR(dquot);
2704                 goto out;
2705         }
2706         rc = do_set_dqblk(dquot, di);
2707         dqput(dquot);
2708 out:
2709         return rc;
2710 }
2711 EXPORT_SYMBOL(dquot_set_dqblk);
2712
2713 /* Generic routine for getting common part of quota file information */
2714 int dquot_get_state(struct super_block *sb, struct qc_state *state)
2715 {
2716         struct mem_dqinfo *mi;
2717         struct qc_type_state *tstate;
2718         struct quota_info *dqopt = sb_dqopt(sb);
2719         int type;
2720   
2721         memset(state, 0, sizeof(*state));
2722         for (type = 0; type < MAXQUOTAS; type++) {
2723                 if (!sb_has_quota_active(sb, type))
2724                         continue;
2725                 tstate = state->s_state + type;
2726                 mi = sb_dqopt(sb)->info + type;
2727                 tstate->flags = QCI_ACCT_ENABLED;
2728                 spin_lock(&dq_data_lock);
2729                 if (mi->dqi_flags & DQF_SYS_FILE)
2730                         tstate->flags |= QCI_SYSFILE;
2731                 if (mi->dqi_flags & DQF_ROOT_SQUASH)
2732                         tstate->flags |= QCI_ROOT_SQUASH;
2733                 if (sb_has_quota_limits_enabled(sb, type))
2734                         tstate->flags |= QCI_LIMITS_ENFORCED;
2735                 tstate->spc_timelimit = mi->dqi_bgrace;
2736                 tstate->ino_timelimit = mi->dqi_igrace;
2737                 tstate->ino = dqopt->files[type]->i_ino;
2738                 tstate->blocks = dqopt->files[type]->i_blocks;
2739                 tstate->nextents = 1;   /* We don't know... */
2740                 spin_unlock(&dq_data_lock);
2741         }
2742         return 0;
2743 }
2744 EXPORT_SYMBOL(dquot_get_state);
2745
2746 /* Generic routine for setting common part of quota file information */
2747 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii)
2748 {
2749         struct mem_dqinfo *mi;
2750         int err = 0;
2751
2752         if ((ii->i_fieldmask & QC_WARNS_MASK) ||
2753             (ii->i_fieldmask & QC_RT_SPC_TIMER))
2754                 return -EINVAL;
2755         if (!sb_has_quota_active(sb, type))
2756                 return -ESRCH;
2757         mi = sb_dqopt(sb)->info + type;
2758         if (ii->i_fieldmask & QC_FLAGS) {
2759                 if ((ii->i_flags & QCI_ROOT_SQUASH &&
2760                      mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD))
2761                         return -EINVAL;
2762         }
2763         spin_lock(&dq_data_lock);
2764         if (ii->i_fieldmask & QC_SPC_TIMER)
2765                 mi->dqi_bgrace = ii->i_spc_timelimit;
2766         if (ii->i_fieldmask & QC_INO_TIMER)
2767                 mi->dqi_igrace = ii->i_ino_timelimit;
2768         if (ii->i_fieldmask & QC_FLAGS) {
2769                 if (ii->i_flags & QCI_ROOT_SQUASH)
2770                         mi->dqi_flags |= DQF_ROOT_SQUASH;
2771                 else
2772                         mi->dqi_flags &= ~DQF_ROOT_SQUASH;
2773         }
2774         spin_unlock(&dq_data_lock);
2775         mark_info_dirty(sb, type);
2776         /* Force write to disk */
2777         sb->dq_op->write_info(sb, type);
2778         return err;
2779 }
2780 EXPORT_SYMBOL(dquot_set_dqinfo);
2781
2782 const struct quotactl_ops dquot_quotactl_ops = {
2783         .quota_on       = dquot_quota_on,
2784         .quota_off      = dquot_quota_off,
2785         .quota_sync     = dquot_quota_sync,
2786         .get_state      = dquot_get_state,
2787         .set_info       = dquot_set_dqinfo,
2788         .get_dqblk      = dquot_get_dqblk,
2789         .get_nextdqblk  = dquot_get_next_dqblk,
2790         .set_dqblk      = dquot_set_dqblk
2791 };
2792 EXPORT_SYMBOL(dquot_quotactl_ops);
2793
2794 const struct quotactl_ops dquot_quotactl_sysfile_ops = {
2795         .quota_enable   = dquot_quota_enable,
2796         .quota_disable  = dquot_quota_disable,
2797         .quota_sync     = dquot_quota_sync,
2798         .get_state      = dquot_get_state,
2799         .set_info       = dquot_set_dqinfo,
2800         .get_dqblk      = dquot_get_dqblk,
2801         .get_nextdqblk  = dquot_get_next_dqblk,
2802         .set_dqblk      = dquot_set_dqblk
2803 };
2804 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);
2805
2806 static int do_proc_dqstats(struct ctl_table *table, int write,
2807                      void __user *buffer, size_t *lenp, loff_t *ppos)
2808 {
2809         unsigned int type = (int *)table->data - dqstats.stat;
2810
2811         /* Update global table */
2812         dqstats.stat[type] =
2813                         percpu_counter_sum_positive(&dqstats.counter[type]);
2814         return proc_dointvec(table, write, buffer, lenp, ppos);
2815 }
2816
2817 static struct ctl_table fs_dqstats_table[] = {
2818         {
2819                 .procname       = "lookups",
2820                 .data           = &dqstats.stat[DQST_LOOKUPS],
2821                 .maxlen         = sizeof(int),
2822                 .mode           = 0444,
2823                 .proc_handler   = do_proc_dqstats,
2824         },
2825         {
2826                 .procname       = "drops",
2827                 .data           = &dqstats.stat[DQST_DROPS],
2828                 .maxlen         = sizeof(int),
2829                 .mode           = 0444,
2830                 .proc_handler   = do_proc_dqstats,
2831         },
2832         {
2833                 .procname       = "reads",
2834                 .data           = &dqstats.stat[DQST_READS],
2835                 .maxlen         = sizeof(int),
2836                 .mode           = 0444,
2837                 .proc_handler   = do_proc_dqstats,
2838         },
2839         {
2840                 .procname       = "writes",
2841                 .data           = &dqstats.stat[DQST_WRITES],
2842                 .maxlen         = sizeof(int),
2843                 .mode           = 0444,
2844                 .proc_handler   = do_proc_dqstats,
2845         },
2846         {
2847                 .procname       = "cache_hits",
2848                 .data           = &dqstats.stat[DQST_CACHE_HITS],
2849                 .maxlen         = sizeof(int),
2850                 .mode           = 0444,
2851                 .proc_handler   = do_proc_dqstats,
2852         },
2853         {
2854                 .procname       = "allocated_dquots",
2855                 .data           = &dqstats.stat[DQST_ALLOC_DQUOTS],
2856                 .maxlen         = sizeof(int),
2857                 .mode           = 0444,
2858                 .proc_handler   = do_proc_dqstats,
2859         },
2860         {
2861                 .procname       = "free_dquots",
2862                 .data           = &dqstats.stat[DQST_FREE_DQUOTS],
2863                 .maxlen         = sizeof(int),
2864                 .mode           = 0444,
2865                 .proc_handler   = do_proc_dqstats,
2866         },
2867         {
2868                 .procname       = "syncs",
2869                 .data           = &dqstats.stat[DQST_SYNCS],
2870                 .maxlen         = sizeof(int),
2871                 .mode           = 0444,
2872                 .proc_handler   = do_proc_dqstats,
2873         },
2874 #ifdef CONFIG_PRINT_QUOTA_WARNING
2875         {
2876                 .procname       = "warnings",
2877                 .data           = &flag_print_warnings,
2878                 .maxlen         = sizeof(int),
2879                 .mode           = 0644,
2880                 .proc_handler   = proc_dointvec,
2881         },
2882 #endif
2883         { },
2884 };
2885
2886 static struct ctl_table fs_table[] = {
2887         {
2888                 .procname       = "quota",
2889                 .mode           = 0555,
2890                 .child          = fs_dqstats_table,
2891         },
2892         { },
2893 };
2894
2895 static struct ctl_table sys_table[] = {
2896         {
2897                 .procname       = "fs",
2898                 .mode           = 0555,
2899                 .child          = fs_table,
2900         },
2901         { },
2902 };
2903
2904 static int __init dquot_init(void)
2905 {
2906         int i, ret;
2907         unsigned long nr_hash, order;
2908
2909         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2910
2911         register_sysctl_table(sys_table);
2912
2913         dquot_cachep = kmem_cache_create("dquot",
2914                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2915                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2916                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2917                         NULL);
2918
2919         order = 0;
2920         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2921         if (!dquot_hash)
2922                 panic("Cannot create dquot hash table");
2923
2924         for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
2925                 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL);
2926                 if (ret)
2927                         panic("Cannot create dquot stat counters");
2928         }
2929
2930         /* Find power-of-two hlist_heads which can fit into allocation */
2931         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2932         dq_hash_bits = 0;
2933         do {
2934                 dq_hash_bits++;
2935         } while (nr_hash >> dq_hash_bits);
2936         dq_hash_bits--;
2937
2938         nr_hash = 1UL << dq_hash_bits;
2939         dq_hash_mask = nr_hash - 1;
2940         for (i = 0; i < nr_hash; i++)
2941                 INIT_HLIST_HEAD(dquot_hash + i);
2942
2943         pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld,"
2944                 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order));
2945
2946         register_shrinker(&dqcache_shrinker);
2947
2948         return 0;
2949 }
2950 fs_initcall(dquot_init);