d881d5a073b91aa9843503daec2f273fc8d895a9
[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/cred.h>
76 #include <linux/kmod.h>
77 #include <linux/namei.h>
78 #include <linux/capability.h>
79 #include <linux/quotaops.h>
80 #include "../internal.h" /* ugh */
81
82 #include <linux/uaccess.h>
83
84 /*
85  * There are three quota SMP locks. dq_list_lock protects all lists with quotas
86  * and quota formats.
87  * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
88  * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
89  * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
90  * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
91  * modifications of quota state (on quotaon and quotaoff) and readers who care
92  * about latest values take it as well.
93  *
94  * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
95  *   dq_list_lock > dq_state_lock
96  *
97  * Note that some things (eg. sb pointer, type, id) doesn't change during
98  * the life of the dquot structure and so needn't to be protected by a lock
99  *
100  * Operation accessing dquots via inode pointers are protected by dquot_srcu.
101  * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and
102  * synchronize_srcu(&dquot_srcu) is called after clearing pointers from
103  * inode and before dropping dquot references to avoid use of dquots after
104  * they are freed. dq_data_lock is used to serialize the pointer setting and
105  * clearing operations.
106  * Special care needs to be taken about S_NOQUOTA inode flag (marking that
107  * inode is a quota file). Functions adding pointers from inode to dquots have
108  * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they
109  * have to do all pointer modifications before dropping dq_data_lock. This makes
110  * sure they cannot race with quotaon which first sets S_NOQUOTA flag and
111  * then drops all pointers to dquots from an inode.
112  *
113  * Each dquot has its dq_lock mutex.  Dquot is locked when it is being read to
114  * memory (or space for it is being allocated) on the first dqget(), when it is
115  * being written out, and when it is being released on the last dqput(). The
116  * allocation and release operations are serialized by the dq_lock and by
117  * checking the use count in dquot_release().
118  *
119  * Lock ordering (including related VFS locks) is the following:
120  *   s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem
121  */
122
123 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
124 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
125 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
126 EXPORT_SYMBOL(dq_data_lock);
127 DEFINE_STATIC_SRCU(dquot_srcu);
128
129 static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq);
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 (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
345                 return 0;
346
347         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
348                 return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags);
349
350         /* If quota is dirty already, we don't have to acquire dq_list_lock */
351         if (test_bit(DQ_MOD_B, &dquot->dq_flags))
352                 return 1;
353
354         spin_lock(&dq_list_lock);
355         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) {
356                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
357                                 info[dquot->dq_id.type].dqi_dirty_list);
358                 ret = 0;
359         }
360         spin_unlock(&dq_list_lock);
361         return ret;
362 }
363 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
364
365 /* Dirtify all the dquots - this can block when journalling */
366 static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
367 {
368         int ret, err, cnt;
369
370         ret = err = 0;
371         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
372                 if (dquot[cnt])
373                         /* Even in case of error we have to continue */
374                         ret = mark_dquot_dirty(dquot[cnt]);
375                 if (!err)
376                         err = ret;
377         }
378         return err;
379 }
380
381 static inline void dqput_all(struct dquot **dquot)
382 {
383         unsigned int cnt;
384
385         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
386                 dqput(dquot[cnt]);
387 }
388
389 static inline int clear_dquot_dirty(struct dquot *dquot)
390 {
391         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
392                 return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags);
393
394         spin_lock(&dq_list_lock);
395         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) {
396                 spin_unlock(&dq_list_lock);
397                 return 0;
398         }
399         list_del_init(&dquot->dq_dirty);
400         spin_unlock(&dq_list_lock);
401         return 1;
402 }
403
404 void mark_info_dirty(struct super_block *sb, int type)
405 {
406         spin_lock(&dq_data_lock);
407         sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY;
408         spin_unlock(&dq_data_lock);
409 }
410 EXPORT_SYMBOL(mark_info_dirty);
411
412 /*
413  *      Read dquot from disk and alloc space for it
414  */
415
416 int dquot_acquire(struct dquot *dquot)
417 {
418         int ret = 0, ret2 = 0;
419         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
420
421         mutex_lock(&dquot->dq_lock);
422         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
423                 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
424         if (ret < 0)
425                 goto out_iolock;
426         /* Make sure flags update is visible after dquot has been filled */
427         smp_mb__before_atomic();
428         set_bit(DQ_READ_B, &dquot->dq_flags);
429         /* Instantiate dquot if needed */
430         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
431                 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
432                 /* Write the info if needed */
433                 if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
434                         ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
435                                         dquot->dq_sb, dquot->dq_id.type);
436                 }
437                 if (ret < 0)
438                         goto out_iolock;
439                 if (ret2 < 0) {
440                         ret = ret2;
441                         goto out_iolock;
442                 }
443         }
444         /*
445          * Make sure flags update is visible after on-disk struct has been
446          * allocated. Paired with smp_rmb() in dqget().
447          */
448         smp_mb__before_atomic();
449         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
450 out_iolock:
451         mutex_unlock(&dquot->dq_lock);
452         return ret;
453 }
454 EXPORT_SYMBOL(dquot_acquire);
455
456 /*
457  *      Write dquot to disk
458  */
459 int dquot_commit(struct dquot *dquot)
460 {
461         int ret = 0;
462         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
463
464         mutex_lock(&dquot->dq_lock);
465         if (!clear_dquot_dirty(dquot))
466                 goto out_lock;
467         /* Inactive dquot can be only if there was error during read/init
468          * => we have better not writing it */
469         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
470                 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
471         else
472                 ret = -EIO;
473 out_lock:
474         mutex_unlock(&dquot->dq_lock);
475         return ret;
476 }
477 EXPORT_SYMBOL(dquot_commit);
478
479 /*
480  *      Release dquot
481  */
482 int dquot_release(struct dquot *dquot)
483 {
484         int ret = 0, ret2 = 0;
485         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
486
487         mutex_lock(&dquot->dq_lock);
488         /* Check whether we are not racing with some other dqget() */
489         if (atomic_read(&dquot->dq_count) > 1)
490                 goto out_dqlock;
491         if (dqopt->ops[dquot->dq_id.type]->release_dqblk) {
492                 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot);
493                 /* Write the info */
494                 if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
495                         ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
496                                                 dquot->dq_sb, dquot->dq_id.type);
497                 }
498                 if (ret >= 0)
499                         ret = ret2;
500         }
501         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
502 out_dqlock:
503         mutex_unlock(&dquot->dq_lock);
504         return ret;
505 }
506 EXPORT_SYMBOL(dquot_release);
507
508 void dquot_destroy(struct dquot *dquot)
509 {
510         kmem_cache_free(dquot_cachep, dquot);
511 }
512 EXPORT_SYMBOL(dquot_destroy);
513
514 static inline void do_destroy_dquot(struct dquot *dquot)
515 {
516         dquot->dq_sb->dq_op->destroy_dquot(dquot);
517 }
518
519 /* Invalidate all dquots on the list. Note that this function is called after
520  * quota is disabled and pointers from inodes removed so there cannot be new
521  * quota users. There can still be some users of quotas due to inodes being
522  * just deleted or pruned by prune_icache() (those are not attached to any
523  * list) or parallel quotactl call. We have to wait for such users.
524  */
525 static void invalidate_dquots(struct super_block *sb, int type)
526 {
527         struct dquot *dquot, *tmp;
528
529 restart:
530         spin_lock(&dq_list_lock);
531         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
532                 if (dquot->dq_sb != sb)
533                         continue;
534                 if (dquot->dq_id.type != type)
535                         continue;
536                 /* Wait for dquot users */
537                 if (atomic_read(&dquot->dq_count)) {
538                         dqgrab(dquot);
539                         spin_unlock(&dq_list_lock);
540                         /*
541                          * Once dqput() wakes us up, we know it's time to free
542                          * the dquot.
543                          * IMPORTANT: we rely on the fact that there is always
544                          * at most one process waiting for dquot to free.
545                          * Otherwise dq_count would be > 1 and we would never
546                          * wake up.
547                          */
548                         wait_event(dquot_ref_wq,
549                                    atomic_read(&dquot->dq_count) == 1);
550                         dqput(dquot);
551                         /* At this moment dquot() need not exist (it could be
552                          * reclaimed by prune_dqcache(). Hence we must
553                          * restart. */
554                         goto restart;
555                 }
556                 /*
557                  * Quota now has no users and it has been written on last
558                  * dqput()
559                  */
560                 remove_dquot_hash(dquot);
561                 remove_free_dquot(dquot);
562                 remove_inuse(dquot);
563                 do_destroy_dquot(dquot);
564         }
565         spin_unlock(&dq_list_lock);
566 }
567
568 /* Call callback for every active dquot on given filesystem */
569 int dquot_scan_active(struct super_block *sb,
570                       int (*fn)(struct dquot *dquot, unsigned long priv),
571                       unsigned long priv)
572 {
573         struct dquot *dquot, *old_dquot = NULL;
574         int ret = 0;
575
576         WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount));
577
578         spin_lock(&dq_list_lock);
579         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
580                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
581                         continue;
582                 if (dquot->dq_sb != sb)
583                         continue;
584                 /* Now we have active dquot so we can just increase use count */
585                 atomic_inc(&dquot->dq_count);
586                 spin_unlock(&dq_list_lock);
587                 dqstats_inc(DQST_LOOKUPS);
588                 dqput(old_dquot);
589                 old_dquot = dquot;
590                 /*
591                  * ->release_dquot() can be racing with us. Our reference
592                  * protects us from new calls to it so just wait for any
593                  * outstanding call and recheck the DQ_ACTIVE_B after that.
594                  */
595                 wait_on_dquot(dquot);
596                 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
597                         ret = fn(dquot, priv);
598                         if (ret < 0)
599                                 goto out;
600                 }
601                 spin_lock(&dq_list_lock);
602                 /* We are safe to continue now because our dquot could not
603                  * be moved out of the inuse list while we hold the reference */
604         }
605         spin_unlock(&dq_list_lock);
606 out:
607         dqput(old_dquot);
608         return ret;
609 }
610 EXPORT_SYMBOL(dquot_scan_active);
611
612 /* Write all dquot structures to quota files */
613 int dquot_writeback_dquots(struct super_block *sb, int type)
614 {
615         struct list_head *dirty;
616         struct dquot *dquot;
617         struct quota_info *dqopt = sb_dqopt(sb);
618         int cnt;
619         int err, ret = 0;
620
621         WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount));
622
623         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
624                 if (type != -1 && cnt != type)
625                         continue;
626                 if (!sb_has_quota_active(sb, cnt))
627                         continue;
628                 spin_lock(&dq_list_lock);
629                 dirty = &dqopt->info[cnt].dqi_dirty_list;
630                 while (!list_empty(dirty)) {
631                         dquot = list_first_entry(dirty, struct dquot,
632                                                  dq_dirty);
633
634                         WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags));
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_ref_wq);
762                 spin_unlock(&dq_list_lock);
763                 return;
764         }
765         /* Need to release dquot? */
766         if (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                         clear_dquot_dirty(dquot);
779                 }
780                 goto we_slept;
781         }
782         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
783                 spin_unlock(&dq_list_lock);
784                 dquot->dq_sb->dq_op->release_dquot(dquot);
785                 goto we_slept;
786         }
787         atomic_dec(&dquot->dq_count);
788 #ifdef CONFIG_QUOTA_DEBUG
789         /* sanity check */
790         BUG_ON(!list_empty(&dquot->dq_free));
791 #endif
792         put_dquot_last(dquot);
793         spin_unlock(&dq_list_lock);
794 }
795 EXPORT_SYMBOL(dqput);
796
797 struct dquot *dquot_alloc(struct super_block *sb, int type)
798 {
799         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
800 }
801 EXPORT_SYMBOL(dquot_alloc);
802
803 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
804 {
805         struct dquot *dquot;
806
807         dquot = sb->dq_op->alloc_dquot(sb, type);
808         if(!dquot)
809                 return NULL;
810
811         mutex_init(&dquot->dq_lock);
812         INIT_LIST_HEAD(&dquot->dq_free);
813         INIT_LIST_HEAD(&dquot->dq_inuse);
814         INIT_HLIST_NODE(&dquot->dq_hash);
815         INIT_LIST_HEAD(&dquot->dq_dirty);
816         dquot->dq_sb = sb;
817         dquot->dq_id = make_kqid_invalid(type);
818         atomic_set(&dquot->dq_count, 1);
819
820         return dquot;
821 }
822
823 /*
824  * Get reference to dquot
825  *
826  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
827  * destroying our dquot by:
828  *   a) checking for quota flags under dq_list_lock and
829  *   b) getting a reference to dquot before we release dq_list_lock
830  */
831 struct dquot *dqget(struct super_block *sb, struct kqid qid)
832 {
833         unsigned int hashent = hashfn(sb, qid);
834         struct dquot *dquot, *empty = NULL;
835
836         if (!qid_has_mapping(sb->s_user_ns, qid))
837                 return ERR_PTR(-EINVAL);
838
839         if (!sb_has_quota_active(sb, qid.type))
840                 return ERR_PTR(-ESRCH);
841 we_slept:
842         spin_lock(&dq_list_lock);
843         spin_lock(&dq_state_lock);
844         if (!sb_has_quota_active(sb, qid.type)) {
845                 spin_unlock(&dq_state_lock);
846                 spin_unlock(&dq_list_lock);
847                 dquot = ERR_PTR(-ESRCH);
848                 goto out;
849         }
850         spin_unlock(&dq_state_lock);
851
852         dquot = find_dquot(hashent, sb, qid);
853         if (!dquot) {
854                 if (!empty) {
855                         spin_unlock(&dq_list_lock);
856                         empty = get_empty_dquot(sb, qid.type);
857                         if (!empty)
858                                 schedule();     /* Try to wait for a moment... */
859                         goto we_slept;
860                 }
861                 dquot = empty;
862                 empty = NULL;
863                 dquot->dq_id = qid;
864                 /* all dquots go on the inuse_list */
865                 put_inuse(dquot);
866                 /* hash it first so it can be found */
867                 insert_dquot_hash(dquot);
868                 spin_unlock(&dq_list_lock);
869                 dqstats_inc(DQST_LOOKUPS);
870         } else {
871                 if (!atomic_read(&dquot->dq_count))
872                         remove_free_dquot(dquot);
873                 atomic_inc(&dquot->dq_count);
874                 spin_unlock(&dq_list_lock);
875                 dqstats_inc(DQST_CACHE_HITS);
876                 dqstats_inc(DQST_LOOKUPS);
877         }
878         /* Wait for dq_lock - after this we know that either dquot_release() is
879          * already finished or it will be canceled due to dq_count > 1 test */
880         wait_on_dquot(dquot);
881         /* Read the dquot / allocate space in quota file */
882         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
883                 int err;
884
885                 err = sb->dq_op->acquire_dquot(dquot);
886                 if (err < 0) {
887                         dqput(dquot);
888                         dquot = ERR_PTR(err);
889                         goto out;
890                 }
891         }
892         /*
893          * Make sure following reads see filled structure - paired with
894          * smp_mb__before_atomic() in dquot_acquire().
895          */
896         smp_rmb();
897 #ifdef CONFIG_QUOTA_DEBUG
898         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
899 #endif
900 out:
901         if (empty)
902                 do_destroy_dquot(empty);
903
904         return dquot;
905 }
906 EXPORT_SYMBOL(dqget);
907
908 static inline struct dquot **i_dquot(struct inode *inode)
909 {
910         return inode->i_sb->s_op->get_dquots(inode);
911 }
912
913 static int dqinit_needed(struct inode *inode, int type)
914 {
915         struct dquot * const *dquots;
916         int cnt;
917
918         if (IS_NOQUOTA(inode))
919                 return 0;
920
921         dquots = i_dquot(inode);
922         if (type != -1)
923                 return !dquots[type];
924         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
925                 if (!dquots[cnt])
926                         return 1;
927         return 0;
928 }
929
930 /* This routine is guarded by s_umount semaphore */
931 static void add_dquot_ref(struct super_block *sb, int type)
932 {
933         struct inode *inode, *old_inode = NULL;
934 #ifdef CONFIG_QUOTA_DEBUG
935         int reserved = 0;
936 #endif
937
938         spin_lock(&sb->s_inode_list_lock);
939         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
940                 spin_lock(&inode->i_lock);
941                 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
942                     !atomic_read(&inode->i_writecount) ||
943                     !dqinit_needed(inode, type)) {
944                         spin_unlock(&inode->i_lock);
945                         continue;
946                 }
947                 __iget(inode);
948                 spin_unlock(&inode->i_lock);
949                 spin_unlock(&sb->s_inode_list_lock);
950
951 #ifdef CONFIG_QUOTA_DEBUG
952                 if (unlikely(inode_get_rsv_space(inode) > 0))
953                         reserved = 1;
954 #endif
955                 iput(old_inode);
956                 __dquot_initialize(inode, type);
957
958                 /*
959                  * We hold a reference to 'inode' so it couldn't have been
960                  * removed from s_inodes list while we dropped the
961                  * s_inode_list_lock. We cannot iput the inode now as we can be
962                  * holding the last reference and we cannot iput it under
963                  * s_inode_list_lock. So we keep the reference and iput it
964                  * later.
965                  */
966                 old_inode = inode;
967                 spin_lock(&sb->s_inode_list_lock);
968         }
969         spin_unlock(&sb->s_inode_list_lock);
970         iput(old_inode);
971
972 #ifdef CONFIG_QUOTA_DEBUG
973         if (reserved) {
974                 quota_error(sb, "Writes happened before quota was turned on "
975                         "thus quota information is probably inconsistent. "
976                         "Please run quotacheck(8)");
977         }
978 #endif
979 }
980
981 /*
982  * Remove references to dquots from inode and add dquot to list for freeing
983  * if we have the last reference to dquot
984  */
985 static void remove_inode_dquot_ref(struct inode *inode, int type,
986                                    struct list_head *tofree_head)
987 {
988         struct dquot **dquots = i_dquot(inode);
989         struct dquot *dquot = dquots[type];
990
991         if (!dquot)
992                 return;
993
994         dquots[type] = NULL;
995         if (list_empty(&dquot->dq_free)) {
996                 /*
997                  * The inode still has reference to dquot so it can't be in the
998                  * free list
999                  */
1000                 spin_lock(&dq_list_lock);
1001                 list_add(&dquot->dq_free, tofree_head);
1002                 spin_unlock(&dq_list_lock);
1003         } else {
1004                 /*
1005                  * Dquot is already in a list to put so we won't drop the last
1006                  * reference here.
1007                  */
1008                 dqput(dquot);
1009         }
1010 }
1011
1012 /*
1013  * Free list of dquots
1014  * Dquots are removed from inodes and no new references can be got so we are
1015  * the only ones holding reference
1016  */
1017 static void put_dquot_list(struct list_head *tofree_head)
1018 {
1019         struct list_head *act_head;
1020         struct dquot *dquot;
1021
1022         act_head = tofree_head->next;
1023         while (act_head != tofree_head) {
1024                 dquot = list_entry(act_head, struct dquot, dq_free);
1025                 act_head = act_head->next;
1026                 /* Remove dquot from the list so we won't have problems... */
1027                 list_del_init(&dquot->dq_free);
1028                 dqput(dquot);
1029         }
1030 }
1031
1032 static void remove_dquot_ref(struct super_block *sb, int type,
1033                 struct list_head *tofree_head)
1034 {
1035         struct inode *inode;
1036         int reserved = 0;
1037
1038         spin_lock(&sb->s_inode_list_lock);
1039         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
1040                 /*
1041                  *  We have to scan also I_NEW inodes because they can already
1042                  *  have quota pointer initialized. Luckily, we need to touch
1043                  *  only quota pointers and these have separate locking
1044                  *  (dq_data_lock).
1045                  */
1046                 spin_lock(&dq_data_lock);
1047                 if (!IS_NOQUOTA(inode)) {
1048                         if (unlikely(inode_get_rsv_space(inode) > 0))
1049                                 reserved = 1;
1050                         remove_inode_dquot_ref(inode, type, tofree_head);
1051                 }
1052                 spin_unlock(&dq_data_lock);
1053         }
1054         spin_unlock(&sb->s_inode_list_lock);
1055 #ifdef CONFIG_QUOTA_DEBUG
1056         if (reserved) {
1057                 printk(KERN_WARNING "VFS (%s): Writes happened after quota"
1058                         " was disabled thus quota information is probably "
1059                         "inconsistent. Please run quotacheck(8).\n", sb->s_id);
1060         }
1061 #endif
1062 }
1063
1064 /* Gather all references from inodes and drop them */
1065 static void drop_dquot_ref(struct super_block *sb, int type)
1066 {
1067         LIST_HEAD(tofree_head);
1068
1069         if (sb->dq_op) {
1070                 remove_dquot_ref(sb, type, &tofree_head);
1071                 synchronize_srcu(&dquot_srcu);
1072                 put_dquot_list(&tofree_head);
1073         }
1074 }
1075
1076 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
1077 {
1078         dquot->dq_dqb.dqb_curinodes += number;
1079 }
1080
1081 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
1082 {
1083         dquot->dq_dqb.dqb_curspace += number;
1084 }
1085
1086 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
1087 {
1088         dquot->dq_dqb.dqb_rsvspace += number;
1089 }
1090
1091 /*
1092  * Claim reserved quota space
1093  */
1094 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number)
1095 {
1096         if (dquot->dq_dqb.dqb_rsvspace < number) {
1097                 WARN_ON_ONCE(1);
1098                 number = dquot->dq_dqb.dqb_rsvspace;
1099         }
1100         dquot->dq_dqb.dqb_curspace += number;
1101         dquot->dq_dqb.dqb_rsvspace -= number;
1102 }
1103
1104 static void dquot_reclaim_reserved_space(struct dquot *dquot, qsize_t number)
1105 {
1106         if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number))
1107                 number = dquot->dq_dqb.dqb_curspace;
1108         dquot->dq_dqb.dqb_rsvspace += number;
1109         dquot->dq_dqb.dqb_curspace -= number;
1110 }
1111
1112 static inline
1113 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
1114 {
1115         if (dquot->dq_dqb.dqb_rsvspace >= number)
1116                 dquot->dq_dqb.dqb_rsvspace -= number;
1117         else {
1118                 WARN_ON_ONCE(1);
1119                 dquot->dq_dqb.dqb_rsvspace = 0;
1120         }
1121 }
1122
1123 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1124 {
1125         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1126             dquot->dq_dqb.dqb_curinodes >= number)
1127                 dquot->dq_dqb.dqb_curinodes -= number;
1128         else
1129                 dquot->dq_dqb.dqb_curinodes = 0;
1130         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1131                 dquot->dq_dqb.dqb_itime = (time64_t) 0;
1132         clear_bit(DQ_INODES_B, &dquot->dq_flags);
1133 }
1134
1135 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1136 {
1137         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1138             dquot->dq_dqb.dqb_curspace >= number)
1139                 dquot->dq_dqb.dqb_curspace -= number;
1140         else
1141                 dquot->dq_dqb.dqb_curspace = 0;
1142         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1143                 dquot->dq_dqb.dqb_btime = (time64_t) 0;
1144         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1145 }
1146
1147 struct dquot_warn {
1148         struct super_block *w_sb;
1149         struct kqid w_dq_id;
1150         short w_type;
1151 };
1152
1153 static int warning_issued(struct dquot *dquot, const int warntype)
1154 {
1155         int flag = (warntype == QUOTA_NL_BHARDWARN ||
1156                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1157                 ((warntype == QUOTA_NL_IHARDWARN ||
1158                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1159
1160         if (!flag)
1161                 return 0;
1162         return test_and_set_bit(flag, &dquot->dq_flags);
1163 }
1164
1165 #ifdef CONFIG_PRINT_QUOTA_WARNING
1166 static int flag_print_warnings = 1;
1167
1168 static int need_print_warning(struct dquot_warn *warn)
1169 {
1170         if (!flag_print_warnings)
1171                 return 0;
1172
1173         switch (warn->w_dq_id.type) {
1174                 case USRQUOTA:
1175                         return uid_eq(current_fsuid(), warn->w_dq_id.uid);
1176                 case GRPQUOTA:
1177                         return in_group_p(warn->w_dq_id.gid);
1178                 case PRJQUOTA:
1179                         return 1;
1180         }
1181         return 0;
1182 }
1183
1184 /* Print warning to user which exceeded quota */
1185 static void print_warning(struct dquot_warn *warn)
1186 {
1187         char *msg = NULL;
1188         struct tty_struct *tty;
1189         int warntype = warn->w_type;
1190
1191         if (warntype == QUOTA_NL_IHARDBELOW ||
1192             warntype == QUOTA_NL_ISOFTBELOW ||
1193             warntype == QUOTA_NL_BHARDBELOW ||
1194             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn))
1195                 return;
1196
1197         tty = get_current_tty();
1198         if (!tty)
1199                 return;
1200         tty_write_message(tty, warn->w_sb->s_id);
1201         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1202                 tty_write_message(tty, ": warning, ");
1203         else
1204                 tty_write_message(tty, ": write failed, ");
1205         tty_write_message(tty, quotatypes[warn->w_dq_id.type]);
1206         switch (warntype) {
1207                 case QUOTA_NL_IHARDWARN:
1208                         msg = " file limit reached.\r\n";
1209                         break;
1210                 case QUOTA_NL_ISOFTLONGWARN:
1211                         msg = " file quota exceeded too long.\r\n";
1212                         break;
1213                 case QUOTA_NL_ISOFTWARN:
1214                         msg = " file quota exceeded.\r\n";
1215                         break;
1216                 case QUOTA_NL_BHARDWARN:
1217                         msg = " block limit reached.\r\n";
1218                         break;
1219                 case QUOTA_NL_BSOFTLONGWARN:
1220                         msg = " block quota exceeded too long.\r\n";
1221                         break;
1222                 case QUOTA_NL_BSOFTWARN:
1223                         msg = " block quota exceeded.\r\n";
1224                         break;
1225         }
1226         tty_write_message(tty, msg);
1227         tty_kref_put(tty);
1228 }
1229 #endif
1230
1231 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot,
1232                             int warntype)
1233 {
1234         if (warning_issued(dquot, warntype))
1235                 return;
1236         warn->w_type = warntype;
1237         warn->w_sb = dquot->dq_sb;
1238         warn->w_dq_id = dquot->dq_id;
1239 }
1240
1241 /*
1242  * Write warnings to the console and send warning messages over netlink.
1243  *
1244  * Note that this function can call into tty and networking code.
1245  */
1246 static void flush_warnings(struct dquot_warn *warn)
1247 {
1248         int i;
1249
1250         for (i = 0; i < MAXQUOTAS; i++) {
1251                 if (warn[i].w_type == QUOTA_NL_NOWARN)
1252                         continue;
1253 #ifdef CONFIG_PRINT_QUOTA_WARNING
1254                 print_warning(&warn[i]);
1255 #endif
1256                 quota_send_warning(warn[i].w_dq_id,
1257                                    warn[i].w_sb->s_dev, warn[i].w_type);
1258         }
1259 }
1260
1261 static int ignore_hardlimit(struct dquot *dquot)
1262 {
1263         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
1264
1265         return capable(CAP_SYS_RESOURCE) &&
1266                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1267                 !(info->dqi_flags & DQF_ROOT_SQUASH));
1268 }
1269
1270 /* needs dq_data_lock */
1271 static int check_idq(struct dquot *dquot, qsize_t inodes,
1272                      struct dquot_warn *warn)
1273 {
1274         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1275
1276         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) ||
1277             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1278                 return 0;
1279
1280         if (dquot->dq_dqb.dqb_ihardlimit &&
1281             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1282             !ignore_hardlimit(dquot)) {
1283                 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN);
1284                 return -EDQUOT;
1285         }
1286
1287         if (dquot->dq_dqb.dqb_isoftlimit &&
1288             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1289             dquot->dq_dqb.dqb_itime &&
1290             ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime &&
1291             !ignore_hardlimit(dquot)) {
1292                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN);
1293                 return -EDQUOT;
1294         }
1295
1296         if (dquot->dq_dqb.dqb_isoftlimit &&
1297             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1298             dquot->dq_dqb.dqb_itime == 0) {
1299                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN);
1300                 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() +
1301                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace;
1302         }
1303
1304         return 0;
1305 }
1306
1307 /* needs dq_data_lock */
1308 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc,
1309                      struct dquot_warn *warn)
1310 {
1311         qsize_t tspace;
1312         struct super_block *sb = dquot->dq_sb;
1313
1314         if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) ||
1315             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1316                 return 0;
1317
1318         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1319                 + space;
1320
1321         if (dquot->dq_dqb.dqb_bhardlimit &&
1322             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1323             !ignore_hardlimit(dquot)) {
1324                 if (!prealloc)
1325                         prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN);
1326                 return -EDQUOT;
1327         }
1328
1329         if (dquot->dq_dqb.dqb_bsoftlimit &&
1330             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1331             dquot->dq_dqb.dqb_btime &&
1332             ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime &&
1333             !ignore_hardlimit(dquot)) {
1334                 if (!prealloc)
1335                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN);
1336                 return -EDQUOT;
1337         }
1338
1339         if (dquot->dq_dqb.dqb_bsoftlimit &&
1340             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1341             dquot->dq_dqb.dqb_btime == 0) {
1342                 if (!prealloc) {
1343                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN);
1344                         dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() +
1345                             sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace;
1346                 }
1347                 else
1348                         /*
1349                          * We don't allow preallocation to exceed softlimit so exceeding will
1350                          * be always printed
1351                          */
1352                         return -EDQUOT;
1353         }
1354
1355         return 0;
1356 }
1357
1358 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1359 {
1360         qsize_t newinodes;
1361
1362         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1363             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1364             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type))
1365                 return QUOTA_NL_NOWARN;
1366
1367         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1368         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1369                 return QUOTA_NL_ISOFTBELOW;
1370         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1371             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1372                 return QUOTA_NL_IHARDBELOW;
1373         return QUOTA_NL_NOWARN;
1374 }
1375
1376 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1377 {
1378         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1379             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1380                 return QUOTA_NL_NOWARN;
1381
1382         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1383                 return QUOTA_NL_BSOFTBELOW;
1384         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1385             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1386                 return QUOTA_NL_BHARDBELOW;
1387         return QUOTA_NL_NOWARN;
1388 }
1389
1390 static int dquot_active(const struct inode *inode)
1391 {
1392         struct super_block *sb = inode->i_sb;
1393
1394         if (IS_NOQUOTA(inode))
1395                 return 0;
1396         return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
1397 }
1398
1399 /*
1400  * Initialize quota pointers in inode
1401  *
1402  * It is better to call this function outside of any transaction as it
1403  * might need a lot of space in journal for dquot structure allocation.
1404  */
1405 static int __dquot_initialize(struct inode *inode, int type)
1406 {
1407         int cnt, init_needed = 0;
1408         struct dquot **dquots, *got[MAXQUOTAS] = {};
1409         struct super_block *sb = inode->i_sb;
1410         qsize_t rsv;
1411         int ret = 0;
1412
1413         if (!dquot_active(inode))
1414                 return 0;
1415
1416         dquots = i_dquot(inode);
1417
1418         /* First get references to structures we might need. */
1419         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1420                 struct kqid qid;
1421                 kprojid_t projid;
1422                 int rc;
1423                 struct dquot *dquot;
1424
1425                 if (type != -1 && cnt != type)
1426                         continue;
1427                 /*
1428                  * The i_dquot should have been initialized in most cases,
1429                  * we check it without locking here to avoid unnecessary
1430                  * dqget()/dqput() calls.
1431                  */
1432                 if (dquots[cnt])
1433                         continue;
1434
1435                 if (!sb_has_quota_active(sb, cnt))
1436                         continue;
1437
1438                 init_needed = 1;
1439
1440                 switch (cnt) {
1441                 case USRQUOTA:
1442                         qid = make_kqid_uid(inode->i_uid);
1443                         break;
1444                 case GRPQUOTA:
1445                         qid = make_kqid_gid(inode->i_gid);
1446                         break;
1447                 case PRJQUOTA:
1448                         rc = inode->i_sb->dq_op->get_projid(inode, &projid);
1449                         if (rc)
1450                                 continue;
1451                         qid = make_kqid_projid(projid);
1452                         break;
1453                 }
1454                 dquot = dqget(sb, qid);
1455                 if (IS_ERR(dquot)) {
1456                         /* We raced with somebody turning quotas off... */
1457                         if (PTR_ERR(dquot) != -ESRCH) {
1458                                 ret = PTR_ERR(dquot);
1459                                 goto out_put;
1460                         }
1461                         dquot = NULL;
1462                 }
1463                 got[cnt] = dquot;
1464         }
1465
1466         /* All required i_dquot has been initialized */
1467         if (!init_needed)
1468                 return 0;
1469
1470         spin_lock(&dq_data_lock);
1471         if (IS_NOQUOTA(inode))
1472                 goto out_lock;
1473         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1474                 if (type != -1 && cnt != type)
1475                         continue;
1476                 /* Avoid races with quotaoff() */
1477                 if (!sb_has_quota_active(sb, cnt))
1478                         continue;
1479                 /* We could race with quotaon or dqget() could have failed */
1480                 if (!got[cnt])
1481                         continue;
1482                 if (!dquots[cnt]) {
1483                         dquots[cnt] = got[cnt];
1484                         got[cnt] = NULL;
1485                         /*
1486                          * Make quota reservation system happy if someone
1487                          * did a write before quota was turned on
1488                          */
1489                         rsv = inode_get_rsv_space(inode);
1490                         if (unlikely(rsv))
1491                                 dquot_resv_space(dquots[cnt], rsv);
1492                 }
1493         }
1494 out_lock:
1495         spin_unlock(&dq_data_lock);
1496 out_put:
1497         /* Drop unused references */
1498         dqput_all(got);
1499
1500         return ret;
1501 }
1502
1503 int dquot_initialize(struct inode *inode)
1504 {
1505         return __dquot_initialize(inode, -1);
1506 }
1507 EXPORT_SYMBOL(dquot_initialize);
1508
1509 bool dquot_initialize_needed(struct inode *inode)
1510 {
1511         struct dquot **dquots;
1512         int i;
1513
1514         if (!dquot_active(inode))
1515                 return false;
1516
1517         dquots = i_dquot(inode);
1518         for (i = 0; i < MAXQUOTAS; i++)
1519                 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i))
1520                         return true;
1521         return false;
1522 }
1523 EXPORT_SYMBOL(dquot_initialize_needed);
1524
1525 /*
1526  * Release all quotas referenced by inode.
1527  *
1528  * This function only be called on inode free or converting
1529  * a file to quota file, no other users for the i_dquot in
1530  * both cases, so we needn't call synchronize_srcu() after
1531  * clearing i_dquot.
1532  */
1533 static void __dquot_drop(struct inode *inode)
1534 {
1535         int cnt;
1536         struct dquot **dquots = i_dquot(inode);
1537         struct dquot *put[MAXQUOTAS];
1538
1539         spin_lock(&dq_data_lock);
1540         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1541                 put[cnt] = dquots[cnt];
1542                 dquots[cnt] = NULL;
1543         }
1544         spin_unlock(&dq_data_lock);
1545         dqput_all(put);
1546 }
1547
1548 void dquot_drop(struct inode *inode)
1549 {
1550         struct dquot * const *dquots;
1551         int cnt;
1552
1553         if (IS_NOQUOTA(inode))
1554                 return;
1555
1556         /*
1557          * Test before calling to rule out calls from proc and such
1558          * where we are not allowed to block. Note that this is
1559          * actually reliable test even without the lock - the caller
1560          * must assure that nobody can come after the DQUOT_DROP and
1561          * add quota pointers back anyway.
1562          */
1563         dquots = i_dquot(inode);
1564         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1565                 if (dquots[cnt])
1566                         break;
1567         }
1568
1569         if (cnt < MAXQUOTAS)
1570                 __dquot_drop(inode);
1571 }
1572 EXPORT_SYMBOL(dquot_drop);
1573
1574 /*
1575  * inode_reserved_space is managed internally by quota, and protected by
1576  * i_lock similar to i_blocks+i_bytes.
1577  */
1578 static qsize_t *inode_reserved_space(struct inode * inode)
1579 {
1580         /* Filesystem must explicitly define it's own method in order to use
1581          * quota reservation interface */
1582         BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1583         return inode->i_sb->dq_op->get_reserved_space(inode);
1584 }
1585
1586 static qsize_t inode_get_rsv_space(struct inode *inode)
1587 {
1588         qsize_t ret;
1589
1590         if (!inode->i_sb->dq_op->get_reserved_space)
1591                 return 0;
1592         spin_lock(&inode->i_lock);
1593         ret = *inode_reserved_space(inode);
1594         spin_unlock(&inode->i_lock);
1595         return ret;
1596 }
1597
1598 static void inode_incr_space(struct inode *inode, qsize_t number,
1599                                 int reserve)
1600 {
1601         if (reserve) {
1602                 spin_lock(&inode->i_lock);
1603                 *inode_reserved_space(inode) += number;
1604                 spin_unlock(&inode->i_lock);
1605         } else {
1606                 inode_add_bytes(inode, number);
1607         }
1608 }
1609
1610 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve)
1611 {
1612         if (reserve) {
1613                 spin_lock(&inode->i_lock);
1614                 *inode_reserved_space(inode) -= number;
1615                 spin_unlock(&inode->i_lock);
1616         } else {
1617                 inode_sub_bytes(inode, number);
1618         }
1619 }
1620
1621 /*
1622  * This functions updates i_blocks+i_bytes fields and quota information
1623  * (together with appropriate checks).
1624  *
1625  * NOTE: We absolutely rely on the fact that caller dirties the inode
1626  * (usually helpers in quotaops.h care about this) and holds a handle for
1627  * the current transaction so that dquot write and inode write go into the
1628  * same transaction.
1629  */
1630
1631 /*
1632  * This operation can block, but only after everything is updated
1633  */
1634 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
1635 {
1636         int cnt, ret = 0, index;
1637         struct dquot_warn warn[MAXQUOTAS];
1638         int reserve = flags & DQUOT_SPACE_RESERVE;
1639         struct dquot **dquots;
1640
1641         if (!dquot_active(inode)) {
1642                 inode_incr_space(inode, number, reserve);
1643                 goto out;
1644         }
1645
1646         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1647                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1648
1649         dquots = i_dquot(inode);
1650         index = srcu_read_lock(&dquot_srcu);
1651         spin_lock(&dq_data_lock);
1652         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1653                 if (!dquots[cnt])
1654                         continue;
1655                 ret = check_bdq(dquots[cnt], number,
1656                                 !(flags & DQUOT_SPACE_WARN), &warn[cnt]);
1657                 if (ret && !(flags & DQUOT_SPACE_NOFAIL)) {
1658                         spin_unlock(&dq_data_lock);
1659                         goto out_flush_warn;
1660                 }
1661         }
1662         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1663                 if (!dquots[cnt])
1664                         continue;
1665                 if (reserve)
1666                         dquot_resv_space(dquots[cnt], number);
1667                 else
1668                         dquot_incr_space(dquots[cnt], number);
1669         }
1670         inode_incr_space(inode, number, reserve);
1671         spin_unlock(&dq_data_lock);
1672
1673         if (reserve)
1674                 goto out_flush_warn;
1675         mark_all_dquot_dirty(dquots);
1676 out_flush_warn:
1677         srcu_read_unlock(&dquot_srcu, index);
1678         flush_warnings(warn);
1679 out:
1680         return ret;
1681 }
1682 EXPORT_SYMBOL(__dquot_alloc_space);
1683
1684 /*
1685  * This operation can block, but only after everything is updated
1686  */
1687 int dquot_alloc_inode(struct inode *inode)
1688 {
1689         int cnt, ret = 0, index;
1690         struct dquot_warn warn[MAXQUOTAS];
1691         struct dquot * const *dquots;
1692
1693         if (!dquot_active(inode))
1694                 return 0;
1695         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1696                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1697
1698         dquots = i_dquot(inode);
1699         index = srcu_read_lock(&dquot_srcu);
1700         spin_lock(&dq_data_lock);
1701         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1702                 if (!dquots[cnt])
1703                         continue;
1704                 ret = check_idq(dquots[cnt], 1, &warn[cnt]);
1705                 if (ret)
1706                         goto warn_put_all;
1707         }
1708
1709         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1710                 if (!dquots[cnt])
1711                         continue;
1712                 dquot_incr_inodes(dquots[cnt], 1);
1713         }
1714
1715 warn_put_all:
1716         spin_unlock(&dq_data_lock);
1717         if (ret == 0)
1718                 mark_all_dquot_dirty(dquots);
1719         srcu_read_unlock(&dquot_srcu, index);
1720         flush_warnings(warn);
1721         return ret;
1722 }
1723 EXPORT_SYMBOL(dquot_alloc_inode);
1724
1725 /*
1726  * Convert in-memory reserved quotas to real consumed quotas
1727  */
1728 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
1729 {
1730         struct dquot **dquots;
1731         int cnt, index;
1732
1733         if (!dquot_active(inode)) {
1734                 spin_lock(&inode->i_lock);
1735                 *inode_reserved_space(inode) -= number;
1736                 __inode_add_bytes(inode, number);
1737                 spin_unlock(&inode->i_lock);
1738                 return 0;
1739         }
1740
1741         dquots = i_dquot(inode);
1742         index = srcu_read_lock(&dquot_srcu);
1743         spin_lock(&dq_data_lock);
1744         /* Claim reserved quotas to allocated quotas */
1745         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1746                 if (dquots[cnt])
1747                         dquot_claim_reserved_space(dquots[cnt], number);
1748         }
1749         /* Update inode bytes */
1750         spin_lock(&inode->i_lock);
1751         *inode_reserved_space(inode) -= number;
1752         __inode_add_bytes(inode, number);
1753         spin_unlock(&inode->i_lock);
1754         spin_unlock(&dq_data_lock);
1755         mark_all_dquot_dirty(dquots);
1756         srcu_read_unlock(&dquot_srcu, index);
1757         return 0;
1758 }
1759 EXPORT_SYMBOL(dquot_claim_space_nodirty);
1760
1761 /*
1762  * Convert allocated space back to in-memory reserved quotas
1763  */
1764 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number)
1765 {
1766         struct dquot **dquots;
1767         int cnt, index;
1768
1769         if (!dquot_active(inode)) {
1770                 spin_lock(&inode->i_lock);
1771                 *inode_reserved_space(inode) += number;
1772                 __inode_sub_bytes(inode, number);
1773                 spin_unlock(&inode->i_lock);
1774                 return;
1775         }
1776
1777         dquots = i_dquot(inode);
1778         index = srcu_read_lock(&dquot_srcu);
1779         spin_lock(&dq_data_lock);
1780         /* Claim reserved quotas to allocated quotas */
1781         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1782                 if (dquots[cnt])
1783                         dquot_reclaim_reserved_space(dquots[cnt], number);
1784         }
1785         /* Update inode bytes */
1786         spin_lock(&inode->i_lock);
1787         *inode_reserved_space(inode) += number;
1788         __inode_sub_bytes(inode, number);
1789         spin_unlock(&inode->i_lock);
1790         spin_unlock(&dq_data_lock);
1791         mark_all_dquot_dirty(dquots);
1792         srcu_read_unlock(&dquot_srcu, index);
1793         return;
1794 }
1795 EXPORT_SYMBOL(dquot_reclaim_space_nodirty);
1796
1797 /*
1798  * This operation can block, but only after everything is updated
1799  */
1800 void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
1801 {
1802         unsigned int cnt;
1803         struct dquot_warn warn[MAXQUOTAS];
1804         struct dquot **dquots;
1805         int reserve = flags & DQUOT_SPACE_RESERVE, index;
1806
1807         if (!dquot_active(inode)) {
1808                 inode_decr_space(inode, number, reserve);
1809                 return;
1810         }
1811
1812         dquots = i_dquot(inode);
1813         index = srcu_read_lock(&dquot_srcu);
1814         spin_lock(&dq_data_lock);
1815         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1816                 int wtype;
1817
1818                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1819                 if (!dquots[cnt])
1820                         continue;
1821                 wtype = info_bdq_free(dquots[cnt], number);
1822                 if (wtype != QUOTA_NL_NOWARN)
1823                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1824                 if (reserve)
1825                         dquot_free_reserved_space(dquots[cnt], number);
1826                 else
1827                         dquot_decr_space(dquots[cnt], number);
1828         }
1829         inode_decr_space(inode, number, reserve);
1830         spin_unlock(&dq_data_lock);
1831
1832         if (reserve)
1833                 goto out_unlock;
1834         mark_all_dquot_dirty(dquots);
1835 out_unlock:
1836         srcu_read_unlock(&dquot_srcu, index);
1837         flush_warnings(warn);
1838 }
1839 EXPORT_SYMBOL(__dquot_free_space);
1840
1841 /*
1842  * This operation can block, but only after everything is updated
1843  */
1844 void dquot_free_inode(struct inode *inode)
1845 {
1846         unsigned int cnt;
1847         struct dquot_warn warn[MAXQUOTAS];
1848         struct dquot * const *dquots;
1849         int index;
1850
1851         if (!dquot_active(inode))
1852                 return;
1853
1854         dquots = i_dquot(inode);
1855         index = srcu_read_lock(&dquot_srcu);
1856         spin_lock(&dq_data_lock);
1857         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1858                 int wtype;
1859
1860                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1861                 if (!dquots[cnt])
1862                         continue;
1863                 wtype = info_idq_free(dquots[cnt], 1);
1864                 if (wtype != QUOTA_NL_NOWARN)
1865                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1866                 dquot_decr_inodes(dquots[cnt], 1);
1867         }
1868         spin_unlock(&dq_data_lock);
1869         mark_all_dquot_dirty(dquots);
1870         srcu_read_unlock(&dquot_srcu, index);
1871         flush_warnings(warn);
1872 }
1873 EXPORT_SYMBOL(dquot_free_inode);
1874
1875 /*
1876  * Transfer the number of inode and blocks from one diskquota to an other.
1877  * On success, dquot references in transfer_to are consumed and references
1878  * to original dquots that need to be released are placed there. On failure,
1879  * references are kept untouched.
1880  *
1881  * This operation can block, but only after everything is updated
1882  * A transaction must be started when entering this function.
1883  *
1884  * We are holding reference on transfer_from & transfer_to, no need to
1885  * protect them by srcu_read_lock().
1886  */
1887 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
1888 {
1889         qsize_t space, cur_space;
1890         qsize_t rsv_space = 0;
1891         qsize_t inode_usage = 1;
1892         struct dquot *transfer_from[MAXQUOTAS] = {};
1893         int cnt, ret = 0;
1894         char is_valid[MAXQUOTAS] = {};
1895         struct dquot_warn warn_to[MAXQUOTAS];
1896         struct dquot_warn warn_from_inodes[MAXQUOTAS];
1897         struct dquot_warn warn_from_space[MAXQUOTAS];
1898
1899         if (IS_NOQUOTA(inode))
1900                 return 0;
1901
1902         if (inode->i_sb->dq_op->get_inode_usage) {
1903                 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage);
1904                 if (ret)
1905                         return ret;
1906         }
1907
1908         /* Initialize the arrays */
1909         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1910                 warn_to[cnt].w_type = QUOTA_NL_NOWARN;
1911                 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN;
1912                 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN;
1913         }
1914
1915         spin_lock(&dq_data_lock);
1916         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1917                 spin_unlock(&dq_data_lock);
1918                 return 0;
1919         }
1920         cur_space = inode_get_bytes(inode);
1921         rsv_space = inode_get_rsv_space(inode);
1922         space = cur_space + rsv_space;
1923         /* Build the transfer_from list and check the limits */
1924         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1925                 /*
1926                  * Skip changes for same uid or gid or for turned off quota-type.
1927                  */
1928                 if (!transfer_to[cnt])
1929                         continue;
1930                 /* Avoid races with quotaoff() */
1931                 if (!sb_has_quota_active(inode->i_sb, cnt))
1932                         continue;
1933                 is_valid[cnt] = 1;
1934                 transfer_from[cnt] = i_dquot(inode)[cnt];
1935                 ret = check_idq(transfer_to[cnt], inode_usage, &warn_to[cnt]);
1936                 if (ret)
1937                         goto over_quota;
1938                 ret = check_bdq(transfer_to[cnt], space, 0, &warn_to[cnt]);
1939                 if (ret)
1940                         goto over_quota;
1941         }
1942
1943         /*
1944          * Finally perform the needed transfer from transfer_from to transfer_to
1945          */
1946         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1947                 if (!is_valid[cnt])
1948                         continue;
1949                 /* Due to IO error we might not have transfer_from[] structure */
1950                 if (transfer_from[cnt]) {
1951                         int wtype;
1952                         wtype = info_idq_free(transfer_from[cnt], inode_usage);
1953                         if (wtype != QUOTA_NL_NOWARN)
1954                                 prepare_warning(&warn_from_inodes[cnt],
1955                                                 transfer_from[cnt], wtype);
1956                         wtype = info_bdq_free(transfer_from[cnt], space);
1957                         if (wtype != QUOTA_NL_NOWARN)
1958                                 prepare_warning(&warn_from_space[cnt],
1959                                                 transfer_from[cnt], wtype);
1960                         dquot_decr_inodes(transfer_from[cnt], inode_usage);
1961                         dquot_decr_space(transfer_from[cnt], cur_space);
1962                         dquot_free_reserved_space(transfer_from[cnt],
1963                                                   rsv_space);
1964                 }
1965
1966                 dquot_incr_inodes(transfer_to[cnt], inode_usage);
1967                 dquot_incr_space(transfer_to[cnt], cur_space);
1968                 dquot_resv_space(transfer_to[cnt], rsv_space);
1969
1970                 i_dquot(inode)[cnt] = transfer_to[cnt];
1971         }
1972         spin_unlock(&dq_data_lock);
1973
1974         mark_all_dquot_dirty(transfer_from);
1975         mark_all_dquot_dirty(transfer_to);
1976         flush_warnings(warn_to);
1977         flush_warnings(warn_from_inodes);
1978         flush_warnings(warn_from_space);
1979         /* Pass back references to put */
1980         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1981                 if (is_valid[cnt])
1982                         transfer_to[cnt] = transfer_from[cnt];
1983         return 0;
1984 over_quota:
1985         spin_unlock(&dq_data_lock);
1986         flush_warnings(warn_to);
1987         return ret;
1988 }
1989 EXPORT_SYMBOL(__dquot_transfer);
1990
1991 /* Wrapper for transferring ownership of an inode for uid/gid only
1992  * Called from FSXXX_setattr()
1993  */
1994 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1995 {
1996         struct dquot *transfer_to[MAXQUOTAS] = {};
1997         struct dquot *dquot;
1998         struct super_block *sb = inode->i_sb;
1999         int ret;
2000
2001         if (!dquot_active(inode))
2002                 return 0;
2003
2004         if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){
2005                 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid));
2006                 if (IS_ERR(dquot)) {
2007                         if (PTR_ERR(dquot) != -ESRCH) {
2008                                 ret = PTR_ERR(dquot);
2009                                 goto out_put;
2010                         }
2011                         dquot = NULL;
2012                 }
2013                 transfer_to[USRQUOTA] = dquot;
2014         }
2015         if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){
2016                 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid));
2017                 if (IS_ERR(dquot)) {
2018                         if (PTR_ERR(dquot) != -ESRCH) {
2019                                 ret = PTR_ERR(dquot);
2020                                 goto out_put;
2021                         }
2022                         dquot = NULL;
2023                 }
2024                 transfer_to[GRPQUOTA] = dquot;
2025         }
2026         ret = __dquot_transfer(inode, transfer_to);
2027 out_put:
2028         dqput_all(transfer_to);
2029         return ret;
2030 }
2031 EXPORT_SYMBOL(dquot_transfer);
2032
2033 /*
2034  * Write info of quota file to disk
2035  */
2036 int dquot_commit_info(struct super_block *sb, int type)
2037 {
2038         struct quota_info *dqopt = sb_dqopt(sb);
2039
2040         return dqopt->ops[type]->write_file_info(sb, type);
2041 }
2042 EXPORT_SYMBOL(dquot_commit_info);
2043
2044 int dquot_get_next_id(struct super_block *sb, struct kqid *qid)
2045 {
2046         struct quota_info *dqopt = sb_dqopt(sb);
2047
2048         if (!sb_has_quota_active(sb, qid->type))
2049                 return -ESRCH;
2050         if (!dqopt->ops[qid->type]->get_next_id)
2051                 return -ENOSYS;
2052         return dqopt->ops[qid->type]->get_next_id(sb, qid);
2053 }
2054 EXPORT_SYMBOL(dquot_get_next_id);
2055
2056 /*
2057  * Definitions of diskquota operations.
2058  */
2059 const struct dquot_operations dquot_operations = {
2060         .write_dquot    = dquot_commit,
2061         .acquire_dquot  = dquot_acquire,
2062         .release_dquot  = dquot_release,
2063         .mark_dirty     = dquot_mark_dquot_dirty,
2064         .write_info     = dquot_commit_info,
2065         .alloc_dquot    = dquot_alloc,
2066         .destroy_dquot  = dquot_destroy,
2067         .get_next_id    = dquot_get_next_id,
2068 };
2069 EXPORT_SYMBOL(dquot_operations);
2070
2071 /*
2072  * Generic helper for ->open on filesystems supporting disk quotas.
2073  */
2074 int dquot_file_open(struct inode *inode, struct file *file)
2075 {
2076         int error;
2077
2078         error = generic_file_open(inode, file);
2079         if (!error && (file->f_mode & FMODE_WRITE))
2080                 dquot_initialize(inode);
2081         return error;
2082 }
2083 EXPORT_SYMBOL(dquot_file_open);
2084
2085 /*
2086  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
2087  */
2088 int dquot_disable(struct super_block *sb, int type, unsigned int flags)
2089 {
2090         int cnt, ret = 0;
2091         struct quota_info *dqopt = sb_dqopt(sb);
2092         struct inode *toputinode[MAXQUOTAS];
2093
2094         /* s_umount should be held in exclusive mode */
2095         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2096                 up_read(&sb->s_umount);
2097
2098         /* Cannot turn off usage accounting without turning off limits, or
2099          * suspend quotas and simultaneously turn quotas off. */
2100         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
2101             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
2102             DQUOT_USAGE_ENABLED)))
2103                 return -EINVAL;
2104
2105         /*
2106          * Skip everything if there's nothing to do. We have to do this because
2107          * sometimes we are called when fill_super() failed and calling
2108          * sync_fs() in such cases does no good.
2109          */
2110         if (!sb_any_quota_loaded(sb))
2111                 return 0;
2112
2113         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2114                 toputinode[cnt] = NULL;
2115                 if (type != -1 && cnt != type)
2116                         continue;
2117                 if (!sb_has_quota_loaded(sb, cnt))
2118                         continue;
2119
2120                 if (flags & DQUOT_SUSPENDED) {
2121                         spin_lock(&dq_state_lock);
2122                         dqopt->flags |=
2123                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
2124                         spin_unlock(&dq_state_lock);
2125                 } else {
2126                         spin_lock(&dq_state_lock);
2127                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
2128                         /* Turning off suspended quotas? */
2129                         if (!sb_has_quota_loaded(sb, cnt) &&
2130                             sb_has_quota_suspended(sb, cnt)) {
2131                                 dqopt->flags &= ~dquot_state_flag(
2132                                                         DQUOT_SUSPENDED, cnt);
2133                                 spin_unlock(&dq_state_lock);
2134                                 iput(dqopt->files[cnt]);
2135                                 dqopt->files[cnt] = NULL;
2136                                 continue;
2137                         }
2138                         spin_unlock(&dq_state_lock);
2139                 }
2140
2141                 /* We still have to keep quota loaded? */
2142                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
2143                         continue;
2144
2145                 /* Note: these are blocking operations */
2146                 drop_dquot_ref(sb, cnt);
2147                 invalidate_dquots(sb, cnt);
2148                 /*
2149                  * Now all dquots should be invalidated, all writes done so we
2150                  * should be only users of the info. No locks needed.
2151                  */
2152                 if (info_dirty(&dqopt->info[cnt]))
2153                         sb->dq_op->write_info(sb, cnt);
2154                 if (dqopt->ops[cnt]->free_file_info)
2155                         dqopt->ops[cnt]->free_file_info(sb, cnt);
2156                 put_quota_format(dqopt->info[cnt].dqi_format);
2157
2158                 toputinode[cnt] = dqopt->files[cnt];
2159                 if (!sb_has_quota_loaded(sb, cnt))
2160                         dqopt->files[cnt] = NULL;
2161                 dqopt->info[cnt].dqi_flags = 0;
2162                 dqopt->info[cnt].dqi_igrace = 0;
2163                 dqopt->info[cnt].dqi_bgrace = 0;
2164                 dqopt->ops[cnt] = NULL;
2165         }
2166
2167         /* Skip syncing and setting flags if quota files are hidden */
2168         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
2169                 goto put_inodes;
2170
2171         /* Sync the superblock so that buffers with quota data are written to
2172          * disk (and so userspace sees correct data afterwards). */
2173         if (sb->s_op->sync_fs)
2174                 sb->s_op->sync_fs(sb, 1);
2175         sync_blockdev(sb->s_bdev);
2176         /* Now the quota files are just ordinary files and we can set the
2177          * inode flags back. Moreover we discard the pagecache so that
2178          * userspace sees the writes we did bypassing the pagecache. We
2179          * must also discard the blockdev buffers so that we see the
2180          * changes done by userspace on the next quotaon() */
2181         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2182                 /* This can happen when suspending quotas on remount-ro... */
2183                 if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) {
2184                         inode_lock(toputinode[cnt]);
2185                         toputinode[cnt]->i_flags &= ~S_NOQUOTA;
2186                         truncate_inode_pages(&toputinode[cnt]->i_data, 0);
2187                         inode_unlock(toputinode[cnt]);
2188                         mark_inode_dirty_sync(toputinode[cnt]);
2189                 }
2190         if (sb->s_bdev)
2191                 invalidate_bdev(sb->s_bdev);
2192 put_inodes:
2193         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2194                 if (toputinode[cnt]) {
2195                         /* On remount RO, we keep the inode pointer so that we
2196                          * can reenable quota on the subsequent remount RW. We
2197                          * have to check 'flags' variable and not use sb_has_
2198                          * function because another quotaon / quotaoff could
2199                          * change global state before we got here. We refuse
2200                          * to suspend quotas when there is pending delete on
2201                          * the quota file... */
2202                         if (!(flags & DQUOT_SUSPENDED))
2203                                 iput(toputinode[cnt]);
2204                         else if (!toputinode[cnt]->i_nlink)
2205                                 ret = -EBUSY;
2206                 }
2207         return ret;
2208 }
2209 EXPORT_SYMBOL(dquot_disable);
2210
2211 int dquot_quota_off(struct super_block *sb, int type)
2212 {
2213         return dquot_disable(sb, type,
2214                              DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2215 }
2216 EXPORT_SYMBOL(dquot_quota_off);
2217
2218 /*
2219  *      Turn quotas on on a device
2220  */
2221
2222 /*
2223  * Helper function to turn quotas on when we already have the inode of
2224  * quota file and no quota information is loaded.
2225  */
2226 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2227         unsigned int flags)
2228 {
2229         struct quota_format_type *fmt = find_quota_format(format_id);
2230         struct super_block *sb = inode->i_sb;
2231         struct quota_info *dqopt = sb_dqopt(sb);
2232         int error;
2233
2234         if (!fmt)
2235                 return -ESRCH;
2236         if (!S_ISREG(inode->i_mode)) {
2237                 error = -EACCES;
2238                 goto out_fmt;
2239         }
2240         if (IS_RDONLY(inode)) {
2241                 error = -EROFS;
2242                 goto out_fmt;
2243         }
2244         if (!sb->s_op->quota_write || !sb->s_op->quota_read ||
2245             (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) {
2246                 error = -EINVAL;
2247                 goto out_fmt;
2248         }
2249         /* Filesystems outside of init_user_ns not yet supported */
2250         if (sb->s_user_ns != &init_user_ns) {
2251                 error = -EINVAL;
2252                 goto out_fmt;
2253         }
2254         /* Usage always has to be set... */
2255         if (!(flags & DQUOT_USAGE_ENABLED)) {
2256                 error = -EINVAL;
2257                 goto out_fmt;
2258         }
2259         if (sb_has_quota_loaded(sb, type)) {
2260                 error = -EBUSY;
2261                 goto out_fmt;
2262         }
2263
2264         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2265                 /* As we bypass the pagecache we must now flush all the
2266                  * dirty data and invalidate caches so that kernel sees
2267                  * changes from userspace. It is not enough to just flush
2268                  * the quota file since if blocksize < pagesize, invalidation
2269                  * of the cache could fail because of other unrelated dirty
2270                  * data */
2271                 sync_filesystem(sb);
2272                 invalidate_bdev(sb->s_bdev);
2273         }
2274
2275         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2276                 /* We don't want quota and atime on quota files (deadlocks
2277                  * possible) Also nobody should write to the file - we use
2278                  * special IO operations which ignore the immutable bit. */
2279                 inode_lock(inode);
2280                 inode->i_flags |= S_NOQUOTA;
2281                 inode_unlock(inode);
2282                 /*
2283                  * When S_NOQUOTA is set, remove dquot references as no more
2284                  * references can be added
2285                  */
2286                 __dquot_drop(inode);
2287         }
2288
2289         error = -EIO;
2290         dqopt->files[type] = igrab(inode);
2291         if (!dqopt->files[type])
2292                 goto out_file_flags;
2293         error = -EINVAL;
2294         if (!fmt->qf_ops->check_quota_file(sb, type))
2295                 goto out_file_init;
2296
2297         dqopt->ops[type] = fmt->qf_ops;
2298         dqopt->info[type].dqi_format = fmt;
2299         dqopt->info[type].dqi_fmt_id = format_id;
2300         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2301         error = dqopt->ops[type]->read_file_info(sb, type);
2302         if (error < 0)
2303                 goto out_file_init;
2304         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) {
2305                 spin_lock(&dq_data_lock);
2306                 dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
2307                 spin_unlock(&dq_data_lock);
2308         }
2309         spin_lock(&dq_state_lock);
2310         dqopt->flags |= dquot_state_flag(flags, type);
2311         spin_unlock(&dq_state_lock);
2312
2313         add_dquot_ref(sb, type);
2314
2315         return 0;
2316
2317 out_file_init:
2318         dqopt->files[type] = NULL;
2319         iput(inode);
2320 out_file_flags:
2321         inode_lock(inode);
2322         inode->i_flags &= ~S_NOQUOTA;
2323         inode_unlock(inode);
2324 out_fmt:
2325         put_quota_format(fmt);
2326
2327         return error; 
2328 }
2329
2330 /* Reenable quotas on remount RW */
2331 int dquot_resume(struct super_block *sb, int type)
2332 {
2333         struct quota_info *dqopt = sb_dqopt(sb);
2334         struct inode *inode;
2335         int ret = 0, cnt;
2336         unsigned int flags;
2337
2338         /* s_umount should be held in exclusive mode */
2339         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2340                 up_read(&sb->s_umount);
2341
2342         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2343                 if (type != -1 && cnt != type)
2344                         continue;
2345                 if (!sb_has_quota_suspended(sb, cnt))
2346                         continue;
2347
2348                 inode = dqopt->files[cnt];
2349                 dqopt->files[cnt] = NULL;
2350                 spin_lock(&dq_state_lock);
2351                 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2352                                                         DQUOT_LIMITS_ENABLED,
2353                                                         cnt);
2354                 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
2355                 spin_unlock(&dq_state_lock);
2356
2357                 flags = dquot_generic_flag(flags, cnt);
2358                 ret = vfs_load_quota_inode(inode, cnt,
2359                                 dqopt->info[cnt].dqi_fmt_id, flags);
2360                 iput(inode);
2361         }
2362
2363         return ret;
2364 }
2365 EXPORT_SYMBOL(dquot_resume);
2366
2367 int dquot_quota_on(struct super_block *sb, int type, int format_id,
2368                    const struct path *path)
2369 {
2370         int error = security_quota_on(path->dentry);
2371         if (error)
2372                 return error;
2373         /* Quota file not on the same filesystem? */
2374         if (path->dentry->d_sb != sb)
2375                 error = -EXDEV;
2376         else
2377                 error = vfs_load_quota_inode(d_inode(path->dentry), type,
2378                                              format_id, DQUOT_USAGE_ENABLED |
2379                                              DQUOT_LIMITS_ENABLED);
2380         return error;
2381 }
2382 EXPORT_SYMBOL(dquot_quota_on);
2383
2384 /*
2385  * More powerful function for turning on quotas allowing setting
2386  * of individual quota flags
2387  */
2388 int dquot_enable(struct inode *inode, int type, int format_id,
2389                  unsigned int flags)
2390 {
2391         struct super_block *sb = inode->i_sb;
2392
2393         /* Just unsuspend quotas? */
2394         BUG_ON(flags & DQUOT_SUSPENDED);
2395         /* s_umount should be held in exclusive mode */
2396         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2397                 up_read(&sb->s_umount);
2398
2399         if (!flags)
2400                 return 0;
2401         /* Just updating flags needed? */
2402         if (sb_has_quota_loaded(sb, type)) {
2403                 if (flags & DQUOT_USAGE_ENABLED &&
2404                     sb_has_quota_usage_enabled(sb, type))
2405                         return -EBUSY;
2406                 if (flags & DQUOT_LIMITS_ENABLED &&
2407                     sb_has_quota_limits_enabled(sb, type))
2408                         return -EBUSY;
2409                 spin_lock(&dq_state_lock);
2410                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2411                 spin_unlock(&dq_state_lock);
2412                 return 0;
2413         }
2414
2415         return vfs_load_quota_inode(inode, type, format_id, flags);
2416 }
2417 EXPORT_SYMBOL(dquot_enable);
2418
2419 /*
2420  * This function is used when filesystem needs to initialize quotas
2421  * during mount time.
2422  */
2423 int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
2424                 int format_id, int type)
2425 {
2426         struct dentry *dentry;
2427         int error;
2428
2429         dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name));
2430         if (IS_ERR(dentry))
2431                 return PTR_ERR(dentry);
2432
2433         if (d_really_is_negative(dentry)) {
2434                 error = -ENOENT;
2435                 goto out;
2436         }
2437
2438         error = security_quota_on(dentry);
2439         if (!error)
2440                 error = vfs_load_quota_inode(d_inode(dentry), type, format_id,
2441                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2442
2443 out:
2444         dput(dentry);
2445         return error;
2446 }
2447 EXPORT_SYMBOL(dquot_quota_on_mount);
2448
2449 static int dquot_quota_enable(struct super_block *sb, unsigned int flags)
2450 {
2451         int ret;
2452         int type;
2453         struct quota_info *dqopt = sb_dqopt(sb);
2454
2455         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
2456                 return -ENOSYS;
2457         /* Accounting cannot be turned on while fs is mounted */
2458         flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT);
2459         if (!flags)
2460                 return -EINVAL;
2461         for (type = 0; type < MAXQUOTAS; type++) {
2462                 if (!(flags & qtype_enforce_flag(type)))
2463                         continue;
2464                 /* Can't enforce without accounting */
2465                 if (!sb_has_quota_usage_enabled(sb, type))
2466                         return -EINVAL;
2467                 ret = dquot_enable(dqopt->files[type], type,
2468                                    dqopt->info[type].dqi_fmt_id,
2469                                    DQUOT_LIMITS_ENABLED);
2470                 if (ret < 0)
2471                         goto out_err;
2472         }
2473         return 0;
2474 out_err:
2475         /* Backout enforcement enablement we already did */
2476         for (type--; type >= 0; type--)  {
2477                 if (flags & qtype_enforce_flag(type))
2478                         dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
2479         }
2480         /* Error code translation for better compatibility with XFS */
2481         if (ret == -EBUSY)
2482                 ret = -EEXIST;
2483         return ret;
2484 }
2485
2486 static int dquot_quota_disable(struct super_block *sb, unsigned int flags)
2487 {
2488         int ret;
2489         int type;
2490         struct quota_info *dqopt = sb_dqopt(sb);
2491
2492         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
2493                 return -ENOSYS;
2494         /*
2495          * We don't support turning off accounting via quotactl. In principle
2496          * quota infrastructure can do this but filesystems don't expect
2497          * userspace to be able to do it.
2498          */
2499         if (flags &
2500                   (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT))
2501                 return -EOPNOTSUPP;
2502
2503         /* Filter out limits not enabled */
2504         for (type = 0; type < MAXQUOTAS; type++)
2505                 if (!sb_has_quota_limits_enabled(sb, type))
2506                         flags &= ~qtype_enforce_flag(type);
2507         /* Nothing left? */
2508         if (!flags)
2509                 return -EEXIST;
2510         for (type = 0; type < MAXQUOTAS; type++) {
2511                 if (flags & qtype_enforce_flag(type)) {
2512                         ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
2513                         if (ret < 0)
2514                                 goto out_err;
2515                 }
2516         }
2517         return 0;
2518 out_err:
2519         /* Backout enforcement disabling we already did */
2520         for (type--; type >= 0; type--)  {
2521                 if (flags & qtype_enforce_flag(type))
2522                         dquot_enable(dqopt->files[type], type,
2523                                      dqopt->info[type].dqi_fmt_id,
2524                                      DQUOT_LIMITS_ENABLED);
2525         }
2526         return ret;
2527 }
2528
2529 /* Generic routine for getting common part of quota structure */
2530 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di)
2531 {
2532         struct mem_dqblk *dm = &dquot->dq_dqb;
2533
2534         memset(di, 0, sizeof(*di));
2535         spin_lock(&dq_data_lock);
2536         di->d_spc_hardlimit = dm->dqb_bhardlimit;
2537         di->d_spc_softlimit = dm->dqb_bsoftlimit;
2538         di->d_ino_hardlimit = dm->dqb_ihardlimit;
2539         di->d_ino_softlimit = dm->dqb_isoftlimit;
2540         di->d_space = dm->dqb_curspace + dm->dqb_rsvspace;
2541         di->d_ino_count = dm->dqb_curinodes;
2542         di->d_spc_timer = dm->dqb_btime;
2543         di->d_ino_timer = dm->dqb_itime;
2544         spin_unlock(&dq_data_lock);
2545 }
2546
2547 int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
2548                     struct qc_dqblk *di)
2549 {
2550         struct dquot *dquot;
2551
2552         dquot = dqget(sb, qid);
2553         if (IS_ERR(dquot))
2554                 return PTR_ERR(dquot);
2555         do_get_dqblk(dquot, di);
2556         dqput(dquot);
2557
2558         return 0;
2559 }
2560 EXPORT_SYMBOL(dquot_get_dqblk);
2561
2562 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid,
2563                          struct qc_dqblk *di)
2564 {
2565         struct dquot *dquot;
2566         int err;
2567
2568         if (!sb->dq_op->get_next_id)
2569                 return -ENOSYS;
2570         err = sb->dq_op->get_next_id(sb, qid);
2571         if (err < 0)
2572                 return err;
2573         dquot = dqget(sb, *qid);
2574         if (IS_ERR(dquot))
2575                 return PTR_ERR(dquot);
2576         do_get_dqblk(dquot, di);
2577         dqput(dquot);
2578
2579         return 0;
2580 }
2581 EXPORT_SYMBOL(dquot_get_next_dqblk);
2582
2583 #define VFS_QC_MASK \
2584         (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \
2585          QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \
2586          QC_SPC_TIMER | QC_INO_TIMER)
2587
2588 /* Generic routine for setting common part of quota structure */
2589 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di)
2590 {
2591         struct mem_dqblk *dm = &dquot->dq_dqb;
2592         int check_blim = 0, check_ilim = 0;
2593         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
2594
2595         if (di->d_fieldmask & ~VFS_QC_MASK)
2596                 return -EINVAL;
2597
2598         if (((di->d_fieldmask & QC_SPC_SOFT) &&
2599              di->d_spc_softlimit > dqi->dqi_max_spc_limit) ||
2600             ((di->d_fieldmask & QC_SPC_HARD) &&
2601              di->d_spc_hardlimit > dqi->dqi_max_spc_limit) ||
2602             ((di->d_fieldmask & QC_INO_SOFT) &&
2603              (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) ||
2604             ((di->d_fieldmask & QC_INO_HARD) &&
2605              (di->d_ino_hardlimit > dqi->dqi_max_ino_limit)))
2606                 return -ERANGE;
2607
2608         spin_lock(&dq_data_lock);
2609         if (di->d_fieldmask & QC_SPACE) {
2610                 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace;
2611                 check_blim = 1;
2612                 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2613         }
2614
2615         if (di->d_fieldmask & QC_SPC_SOFT)
2616                 dm->dqb_bsoftlimit = di->d_spc_softlimit;
2617         if (di->d_fieldmask & QC_SPC_HARD)
2618                 dm->dqb_bhardlimit = di->d_spc_hardlimit;
2619         if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) {
2620                 check_blim = 1;
2621                 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2622         }
2623
2624         if (di->d_fieldmask & QC_INO_COUNT) {
2625                 dm->dqb_curinodes = di->d_ino_count;
2626                 check_ilim = 1;
2627                 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2628         }
2629
2630         if (di->d_fieldmask & QC_INO_SOFT)
2631                 dm->dqb_isoftlimit = di->d_ino_softlimit;
2632         if (di->d_fieldmask & QC_INO_HARD)
2633                 dm->dqb_ihardlimit = di->d_ino_hardlimit;
2634         if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) {
2635                 check_ilim = 1;
2636                 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2637         }
2638
2639         if (di->d_fieldmask & QC_SPC_TIMER) {
2640                 dm->dqb_btime = di->d_spc_timer;
2641                 check_blim = 1;
2642                 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2643         }
2644
2645         if (di->d_fieldmask & QC_INO_TIMER) {
2646                 dm->dqb_itime = di->d_ino_timer;
2647                 check_ilim = 1;
2648                 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2649         }
2650
2651         if (check_blim) {
2652                 if (!dm->dqb_bsoftlimit ||
2653                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2654                         dm->dqb_btime = 0;
2655                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2656                 } else if (!(di->d_fieldmask & QC_SPC_TIMER))
2657                         /* Set grace only if user hasn't provided his own... */
2658                         dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace;
2659         }
2660         if (check_ilim) {
2661                 if (!dm->dqb_isoftlimit ||
2662                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2663                         dm->dqb_itime = 0;
2664                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2665                 } else if (!(di->d_fieldmask & QC_INO_TIMER))
2666                         /* Set grace only if user hasn't provided his own... */
2667                         dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace;
2668         }
2669         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2670             dm->dqb_isoftlimit)
2671                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2672         else
2673                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2674         spin_unlock(&dq_data_lock);
2675         mark_dquot_dirty(dquot);
2676
2677         return 0;
2678 }
2679
2680 int dquot_set_dqblk(struct super_block *sb, struct kqid qid,
2681                   struct qc_dqblk *di)
2682 {
2683         struct dquot *dquot;
2684         int rc;
2685
2686         dquot = dqget(sb, qid);
2687         if (IS_ERR(dquot)) {
2688                 rc = PTR_ERR(dquot);
2689                 goto out;
2690         }
2691         rc = do_set_dqblk(dquot, di);
2692         dqput(dquot);
2693 out:
2694         return rc;
2695 }
2696 EXPORT_SYMBOL(dquot_set_dqblk);
2697
2698 /* Generic routine for getting common part of quota file information */
2699 int dquot_get_state(struct super_block *sb, struct qc_state *state)
2700 {
2701         struct mem_dqinfo *mi;
2702         struct qc_type_state *tstate;
2703         struct quota_info *dqopt = sb_dqopt(sb);
2704         int type;
2705   
2706         memset(state, 0, sizeof(*state));
2707         for (type = 0; type < MAXQUOTAS; type++) {
2708                 if (!sb_has_quota_active(sb, type))
2709                         continue;
2710                 tstate = state->s_state + type;
2711                 mi = sb_dqopt(sb)->info + type;
2712                 tstate->flags = QCI_ACCT_ENABLED;
2713                 spin_lock(&dq_data_lock);
2714                 if (mi->dqi_flags & DQF_SYS_FILE)
2715                         tstate->flags |= QCI_SYSFILE;
2716                 if (mi->dqi_flags & DQF_ROOT_SQUASH)
2717                         tstate->flags |= QCI_ROOT_SQUASH;
2718                 if (sb_has_quota_limits_enabled(sb, type))
2719                         tstate->flags |= QCI_LIMITS_ENFORCED;
2720                 tstate->spc_timelimit = mi->dqi_bgrace;
2721                 tstate->ino_timelimit = mi->dqi_igrace;
2722                 tstate->ino = dqopt->files[type]->i_ino;
2723                 tstate->blocks = dqopt->files[type]->i_blocks;
2724                 tstate->nextents = 1;   /* We don't know... */
2725                 spin_unlock(&dq_data_lock);
2726         }
2727         return 0;
2728 }
2729 EXPORT_SYMBOL(dquot_get_state);
2730
2731 /* Generic routine for setting common part of quota file information */
2732 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii)
2733 {
2734         struct mem_dqinfo *mi;
2735         int err = 0;
2736
2737         if ((ii->i_fieldmask & QC_WARNS_MASK) ||
2738             (ii->i_fieldmask & QC_RT_SPC_TIMER))
2739                 return -EINVAL;
2740         if (!sb_has_quota_active(sb, type))
2741                 return -ESRCH;
2742         mi = sb_dqopt(sb)->info + type;
2743         if (ii->i_fieldmask & QC_FLAGS) {
2744                 if ((ii->i_flags & QCI_ROOT_SQUASH &&
2745                      mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD))
2746                         return -EINVAL;
2747         }
2748         spin_lock(&dq_data_lock);
2749         if (ii->i_fieldmask & QC_SPC_TIMER)
2750                 mi->dqi_bgrace = ii->i_spc_timelimit;
2751         if (ii->i_fieldmask & QC_INO_TIMER)
2752                 mi->dqi_igrace = ii->i_ino_timelimit;
2753         if (ii->i_fieldmask & QC_FLAGS) {
2754                 if (ii->i_flags & QCI_ROOT_SQUASH)
2755                         mi->dqi_flags |= DQF_ROOT_SQUASH;
2756                 else
2757                         mi->dqi_flags &= ~DQF_ROOT_SQUASH;
2758         }
2759         spin_unlock(&dq_data_lock);
2760         mark_info_dirty(sb, type);
2761         /* Force write to disk */
2762         sb->dq_op->write_info(sb, type);
2763         return err;
2764 }
2765 EXPORT_SYMBOL(dquot_set_dqinfo);
2766
2767 const struct quotactl_ops dquot_quotactl_sysfile_ops = {
2768         .quota_enable   = dquot_quota_enable,
2769         .quota_disable  = dquot_quota_disable,
2770         .quota_sync     = dquot_quota_sync,
2771         .get_state      = dquot_get_state,
2772         .set_info       = dquot_set_dqinfo,
2773         .get_dqblk      = dquot_get_dqblk,
2774         .get_nextdqblk  = dquot_get_next_dqblk,
2775         .set_dqblk      = dquot_set_dqblk
2776 };
2777 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);
2778
2779 static int do_proc_dqstats(struct ctl_table *table, int write,
2780                      void __user *buffer, size_t *lenp, loff_t *ppos)
2781 {
2782         unsigned int type = (int *)table->data - dqstats.stat;
2783
2784         /* Update global table */
2785         dqstats.stat[type] =
2786                         percpu_counter_sum_positive(&dqstats.counter[type]);
2787         return proc_dointvec(table, write, buffer, lenp, ppos);
2788 }
2789
2790 static struct ctl_table fs_dqstats_table[] = {
2791         {
2792                 .procname       = "lookups",
2793                 .data           = &dqstats.stat[DQST_LOOKUPS],
2794                 .maxlen         = sizeof(int),
2795                 .mode           = 0444,
2796                 .proc_handler   = do_proc_dqstats,
2797         },
2798         {
2799                 .procname       = "drops",
2800                 .data           = &dqstats.stat[DQST_DROPS],
2801                 .maxlen         = sizeof(int),
2802                 .mode           = 0444,
2803                 .proc_handler   = do_proc_dqstats,
2804         },
2805         {
2806                 .procname       = "reads",
2807                 .data           = &dqstats.stat[DQST_READS],
2808                 .maxlen         = sizeof(int),
2809                 .mode           = 0444,
2810                 .proc_handler   = do_proc_dqstats,
2811         },
2812         {
2813                 .procname       = "writes",
2814                 .data           = &dqstats.stat[DQST_WRITES],
2815                 .maxlen         = sizeof(int),
2816                 .mode           = 0444,
2817                 .proc_handler   = do_proc_dqstats,
2818         },
2819         {
2820                 .procname       = "cache_hits",
2821                 .data           = &dqstats.stat[DQST_CACHE_HITS],
2822                 .maxlen         = sizeof(int),
2823                 .mode           = 0444,
2824                 .proc_handler   = do_proc_dqstats,
2825         },
2826         {
2827                 .procname       = "allocated_dquots",
2828                 .data           = &dqstats.stat[DQST_ALLOC_DQUOTS],
2829                 .maxlen         = sizeof(int),
2830                 .mode           = 0444,
2831                 .proc_handler   = do_proc_dqstats,
2832         },
2833         {
2834                 .procname       = "free_dquots",
2835                 .data           = &dqstats.stat[DQST_FREE_DQUOTS],
2836                 .maxlen         = sizeof(int),
2837                 .mode           = 0444,
2838                 .proc_handler   = do_proc_dqstats,
2839         },
2840         {
2841                 .procname       = "syncs",
2842                 .data           = &dqstats.stat[DQST_SYNCS],
2843                 .maxlen         = sizeof(int),
2844                 .mode           = 0444,
2845                 .proc_handler   = do_proc_dqstats,
2846         },
2847 #ifdef CONFIG_PRINT_QUOTA_WARNING
2848         {
2849                 .procname       = "warnings",
2850                 .data           = &flag_print_warnings,
2851                 .maxlen         = sizeof(int),
2852                 .mode           = 0644,
2853                 .proc_handler   = proc_dointvec,
2854         },
2855 #endif
2856         { },
2857 };
2858
2859 static struct ctl_table fs_table[] = {
2860         {
2861                 .procname       = "quota",
2862                 .mode           = 0555,
2863                 .child          = fs_dqstats_table,
2864         },
2865         { },
2866 };
2867
2868 static struct ctl_table sys_table[] = {
2869         {
2870                 .procname       = "fs",
2871                 .mode           = 0555,
2872                 .child          = fs_table,
2873         },
2874         { },
2875 };
2876
2877 static int __init dquot_init(void)
2878 {
2879         int i, ret;
2880         unsigned long nr_hash, order;
2881
2882         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2883
2884         register_sysctl_table(sys_table);
2885
2886         dquot_cachep = kmem_cache_create("dquot",
2887                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2888                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2889                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2890                         NULL);
2891
2892         order = 0;
2893         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2894         if (!dquot_hash)
2895                 panic("Cannot create dquot hash table");
2896
2897         for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
2898                 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL);
2899                 if (ret)
2900                         panic("Cannot create dquot stat counters");
2901         }
2902
2903         /* Find power-of-two hlist_heads which can fit into allocation */
2904         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2905         dq_hash_bits = 0;
2906         do {
2907                 dq_hash_bits++;
2908         } while (nr_hash >> dq_hash_bits);
2909         dq_hash_bits--;
2910
2911         nr_hash = 1UL << dq_hash_bits;
2912         dq_hash_mask = nr_hash - 1;
2913         for (i = 0; i < nr_hash; i++)
2914                 INIT_HLIST_HEAD(dquot_hash + i);
2915
2916         pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld,"
2917                 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order));
2918
2919         register_shrinker(&dqcache_shrinker);
2920
2921         return 0;
2922 }
2923 fs_initcall(dquot_init);