quota: Inline dquot_[re]claim_reserved_space() into callsite
[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 static inline
1092 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
1093 {
1094         if (dquot->dq_dqb.dqb_rsvspace >= number)
1095                 dquot->dq_dqb.dqb_rsvspace -= number;
1096         else {
1097                 WARN_ON_ONCE(1);
1098                 dquot->dq_dqb.dqb_rsvspace = 0;
1099         }
1100 }
1101
1102 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1103 {
1104         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1105             dquot->dq_dqb.dqb_curinodes >= number)
1106                 dquot->dq_dqb.dqb_curinodes -= number;
1107         else
1108                 dquot->dq_dqb.dqb_curinodes = 0;
1109         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1110                 dquot->dq_dqb.dqb_itime = (time64_t) 0;
1111         clear_bit(DQ_INODES_B, &dquot->dq_flags);
1112 }
1113
1114 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1115 {
1116         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1117             dquot->dq_dqb.dqb_curspace >= number)
1118                 dquot->dq_dqb.dqb_curspace -= number;
1119         else
1120                 dquot->dq_dqb.dqb_curspace = 0;
1121         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1122                 dquot->dq_dqb.dqb_btime = (time64_t) 0;
1123         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1124 }
1125
1126 struct dquot_warn {
1127         struct super_block *w_sb;
1128         struct kqid w_dq_id;
1129         short w_type;
1130 };
1131
1132 static int warning_issued(struct dquot *dquot, const int warntype)
1133 {
1134         int flag = (warntype == QUOTA_NL_BHARDWARN ||
1135                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1136                 ((warntype == QUOTA_NL_IHARDWARN ||
1137                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1138
1139         if (!flag)
1140                 return 0;
1141         return test_and_set_bit(flag, &dquot->dq_flags);
1142 }
1143
1144 #ifdef CONFIG_PRINT_QUOTA_WARNING
1145 static int flag_print_warnings = 1;
1146
1147 static int need_print_warning(struct dquot_warn *warn)
1148 {
1149         if (!flag_print_warnings)
1150                 return 0;
1151
1152         switch (warn->w_dq_id.type) {
1153                 case USRQUOTA:
1154                         return uid_eq(current_fsuid(), warn->w_dq_id.uid);
1155                 case GRPQUOTA:
1156                         return in_group_p(warn->w_dq_id.gid);
1157                 case PRJQUOTA:
1158                         return 1;
1159         }
1160         return 0;
1161 }
1162
1163 /* Print warning to user which exceeded quota */
1164 static void print_warning(struct dquot_warn *warn)
1165 {
1166         char *msg = NULL;
1167         struct tty_struct *tty;
1168         int warntype = warn->w_type;
1169
1170         if (warntype == QUOTA_NL_IHARDBELOW ||
1171             warntype == QUOTA_NL_ISOFTBELOW ||
1172             warntype == QUOTA_NL_BHARDBELOW ||
1173             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn))
1174                 return;
1175
1176         tty = get_current_tty();
1177         if (!tty)
1178                 return;
1179         tty_write_message(tty, warn->w_sb->s_id);
1180         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1181                 tty_write_message(tty, ": warning, ");
1182         else
1183                 tty_write_message(tty, ": write failed, ");
1184         tty_write_message(tty, quotatypes[warn->w_dq_id.type]);
1185         switch (warntype) {
1186                 case QUOTA_NL_IHARDWARN:
1187                         msg = " file limit reached.\r\n";
1188                         break;
1189                 case QUOTA_NL_ISOFTLONGWARN:
1190                         msg = " file quota exceeded too long.\r\n";
1191                         break;
1192                 case QUOTA_NL_ISOFTWARN:
1193                         msg = " file quota exceeded.\r\n";
1194                         break;
1195                 case QUOTA_NL_BHARDWARN:
1196                         msg = " block limit reached.\r\n";
1197                         break;
1198                 case QUOTA_NL_BSOFTLONGWARN:
1199                         msg = " block quota exceeded too long.\r\n";
1200                         break;
1201                 case QUOTA_NL_BSOFTWARN:
1202                         msg = " block quota exceeded.\r\n";
1203                         break;
1204         }
1205         tty_write_message(tty, msg);
1206         tty_kref_put(tty);
1207 }
1208 #endif
1209
1210 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot,
1211                             int warntype)
1212 {
1213         if (warning_issued(dquot, warntype))
1214                 return;
1215         warn->w_type = warntype;
1216         warn->w_sb = dquot->dq_sb;
1217         warn->w_dq_id = dquot->dq_id;
1218 }
1219
1220 /*
1221  * Write warnings to the console and send warning messages over netlink.
1222  *
1223  * Note that this function can call into tty and networking code.
1224  */
1225 static void flush_warnings(struct dquot_warn *warn)
1226 {
1227         int i;
1228
1229         for (i = 0; i < MAXQUOTAS; i++) {
1230                 if (warn[i].w_type == QUOTA_NL_NOWARN)
1231                         continue;
1232 #ifdef CONFIG_PRINT_QUOTA_WARNING
1233                 print_warning(&warn[i]);
1234 #endif
1235                 quota_send_warning(warn[i].w_dq_id,
1236                                    warn[i].w_sb->s_dev, warn[i].w_type);
1237         }
1238 }
1239
1240 static int ignore_hardlimit(struct dquot *dquot)
1241 {
1242         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
1243
1244         return capable(CAP_SYS_RESOURCE) &&
1245                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1246                 !(info->dqi_flags & DQF_ROOT_SQUASH));
1247 }
1248
1249 /* needs dq_data_lock */
1250 static int check_idq(struct dquot *dquot, qsize_t inodes,
1251                      struct dquot_warn *warn)
1252 {
1253         qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1254
1255         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) ||
1256             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1257                 return 0;
1258
1259         if (dquot->dq_dqb.dqb_ihardlimit &&
1260             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1261             !ignore_hardlimit(dquot)) {
1262                 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN);
1263                 return -EDQUOT;
1264         }
1265
1266         if (dquot->dq_dqb.dqb_isoftlimit &&
1267             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1268             dquot->dq_dqb.dqb_itime &&
1269             ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime &&
1270             !ignore_hardlimit(dquot)) {
1271                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN);
1272                 return -EDQUOT;
1273         }
1274
1275         if (dquot->dq_dqb.dqb_isoftlimit &&
1276             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1277             dquot->dq_dqb.dqb_itime == 0) {
1278                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN);
1279                 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() +
1280                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace;
1281         }
1282
1283         return 0;
1284 }
1285
1286 /* needs dq_data_lock */
1287 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc,
1288                      struct dquot_warn *warn)
1289 {
1290         qsize_t tspace;
1291         struct super_block *sb = dquot->dq_sb;
1292
1293         if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) ||
1294             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1295                 return 0;
1296
1297         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1298                 + space;
1299
1300         if (dquot->dq_dqb.dqb_bhardlimit &&
1301             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1302             !ignore_hardlimit(dquot)) {
1303                 if (!prealloc)
1304                         prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN);
1305                 return -EDQUOT;
1306         }
1307
1308         if (dquot->dq_dqb.dqb_bsoftlimit &&
1309             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1310             dquot->dq_dqb.dqb_btime &&
1311             ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime &&
1312             !ignore_hardlimit(dquot)) {
1313                 if (!prealloc)
1314                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN);
1315                 return -EDQUOT;
1316         }
1317
1318         if (dquot->dq_dqb.dqb_bsoftlimit &&
1319             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1320             dquot->dq_dqb.dqb_btime == 0) {
1321                 if (!prealloc) {
1322                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN);
1323                         dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() +
1324                             sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace;
1325                 }
1326                 else
1327                         /*
1328                          * We don't allow preallocation to exceed softlimit so exceeding will
1329                          * be always printed
1330                          */
1331                         return -EDQUOT;
1332         }
1333
1334         return 0;
1335 }
1336
1337 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1338 {
1339         qsize_t newinodes;
1340
1341         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1342             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1343             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type))
1344                 return QUOTA_NL_NOWARN;
1345
1346         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1347         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1348                 return QUOTA_NL_ISOFTBELOW;
1349         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1350             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1351                 return QUOTA_NL_IHARDBELOW;
1352         return QUOTA_NL_NOWARN;
1353 }
1354
1355 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1356 {
1357         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1358             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1359                 return QUOTA_NL_NOWARN;
1360
1361         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1362                 return QUOTA_NL_BSOFTBELOW;
1363         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1364             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1365                 return QUOTA_NL_BHARDBELOW;
1366         return QUOTA_NL_NOWARN;
1367 }
1368
1369 static int dquot_active(const struct inode *inode)
1370 {
1371         struct super_block *sb = inode->i_sb;
1372
1373         if (IS_NOQUOTA(inode))
1374                 return 0;
1375         return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
1376 }
1377
1378 /*
1379  * Initialize quota pointers in inode
1380  *
1381  * It is better to call this function outside of any transaction as it
1382  * might need a lot of space in journal for dquot structure allocation.
1383  */
1384 static int __dquot_initialize(struct inode *inode, int type)
1385 {
1386         int cnt, init_needed = 0;
1387         struct dquot **dquots, *got[MAXQUOTAS] = {};
1388         struct super_block *sb = inode->i_sb;
1389         qsize_t rsv;
1390         int ret = 0;
1391
1392         if (!dquot_active(inode))
1393                 return 0;
1394
1395         dquots = i_dquot(inode);
1396
1397         /* First get references to structures we might need. */
1398         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1399                 struct kqid qid;
1400                 kprojid_t projid;
1401                 int rc;
1402                 struct dquot *dquot;
1403
1404                 if (type != -1 && cnt != type)
1405                         continue;
1406                 /*
1407                  * The i_dquot should have been initialized in most cases,
1408                  * we check it without locking here to avoid unnecessary
1409                  * dqget()/dqput() calls.
1410                  */
1411                 if (dquots[cnt])
1412                         continue;
1413
1414                 if (!sb_has_quota_active(sb, cnt))
1415                         continue;
1416
1417                 init_needed = 1;
1418
1419                 switch (cnt) {
1420                 case USRQUOTA:
1421                         qid = make_kqid_uid(inode->i_uid);
1422                         break;
1423                 case GRPQUOTA:
1424                         qid = make_kqid_gid(inode->i_gid);
1425                         break;
1426                 case PRJQUOTA:
1427                         rc = inode->i_sb->dq_op->get_projid(inode, &projid);
1428                         if (rc)
1429                                 continue;
1430                         qid = make_kqid_projid(projid);
1431                         break;
1432                 }
1433                 dquot = dqget(sb, qid);
1434                 if (IS_ERR(dquot)) {
1435                         /* We raced with somebody turning quotas off... */
1436                         if (PTR_ERR(dquot) != -ESRCH) {
1437                                 ret = PTR_ERR(dquot);
1438                                 goto out_put;
1439                         }
1440                         dquot = NULL;
1441                 }
1442                 got[cnt] = dquot;
1443         }
1444
1445         /* All required i_dquot has been initialized */
1446         if (!init_needed)
1447                 return 0;
1448
1449         spin_lock(&dq_data_lock);
1450         if (IS_NOQUOTA(inode))
1451                 goto out_lock;
1452         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1453                 if (type != -1 && cnt != type)
1454                         continue;
1455                 /* Avoid races with quotaoff() */
1456                 if (!sb_has_quota_active(sb, cnt))
1457                         continue;
1458                 /* We could race with quotaon or dqget() could have failed */
1459                 if (!got[cnt])
1460                         continue;
1461                 if (!dquots[cnt]) {
1462                         dquots[cnt] = got[cnt];
1463                         got[cnt] = NULL;
1464                         /*
1465                          * Make quota reservation system happy if someone
1466                          * did a write before quota was turned on
1467                          */
1468                         rsv = inode_get_rsv_space(inode);
1469                         if (unlikely(rsv))
1470                                 dquot_resv_space(dquots[cnt], rsv);
1471                 }
1472         }
1473 out_lock:
1474         spin_unlock(&dq_data_lock);
1475 out_put:
1476         /* Drop unused references */
1477         dqput_all(got);
1478
1479         return ret;
1480 }
1481
1482 int dquot_initialize(struct inode *inode)
1483 {
1484         return __dquot_initialize(inode, -1);
1485 }
1486 EXPORT_SYMBOL(dquot_initialize);
1487
1488 bool dquot_initialize_needed(struct inode *inode)
1489 {
1490         struct dquot **dquots;
1491         int i;
1492
1493         if (!dquot_active(inode))
1494                 return false;
1495
1496         dquots = i_dquot(inode);
1497         for (i = 0; i < MAXQUOTAS; i++)
1498                 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i))
1499                         return true;
1500         return false;
1501 }
1502 EXPORT_SYMBOL(dquot_initialize_needed);
1503
1504 /*
1505  * Release all quotas referenced by inode.
1506  *
1507  * This function only be called on inode free or converting
1508  * a file to quota file, no other users for the i_dquot in
1509  * both cases, so we needn't call synchronize_srcu() after
1510  * clearing i_dquot.
1511  */
1512 static void __dquot_drop(struct inode *inode)
1513 {
1514         int cnt;
1515         struct dquot **dquots = i_dquot(inode);
1516         struct dquot *put[MAXQUOTAS];
1517
1518         spin_lock(&dq_data_lock);
1519         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1520                 put[cnt] = dquots[cnt];
1521                 dquots[cnt] = NULL;
1522         }
1523         spin_unlock(&dq_data_lock);
1524         dqput_all(put);
1525 }
1526
1527 void dquot_drop(struct inode *inode)
1528 {
1529         struct dquot * const *dquots;
1530         int cnt;
1531
1532         if (IS_NOQUOTA(inode))
1533                 return;
1534
1535         /*
1536          * Test before calling to rule out calls from proc and such
1537          * where we are not allowed to block. Note that this is
1538          * actually reliable test even without the lock - the caller
1539          * must assure that nobody can come after the DQUOT_DROP and
1540          * add quota pointers back anyway.
1541          */
1542         dquots = i_dquot(inode);
1543         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1544                 if (dquots[cnt])
1545                         break;
1546         }
1547
1548         if (cnt < MAXQUOTAS)
1549                 __dquot_drop(inode);
1550 }
1551 EXPORT_SYMBOL(dquot_drop);
1552
1553 /*
1554  * inode_reserved_space is managed internally by quota, and protected by
1555  * i_lock similar to i_blocks+i_bytes.
1556  */
1557 static qsize_t *inode_reserved_space(struct inode * inode)
1558 {
1559         /* Filesystem must explicitly define it's own method in order to use
1560          * quota reservation interface */
1561         BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1562         return inode->i_sb->dq_op->get_reserved_space(inode);
1563 }
1564
1565 static qsize_t inode_get_rsv_space(struct inode *inode)
1566 {
1567         qsize_t ret;
1568
1569         if (!inode->i_sb->dq_op->get_reserved_space)
1570                 return 0;
1571         spin_lock(&inode->i_lock);
1572         ret = *inode_reserved_space(inode);
1573         spin_unlock(&inode->i_lock);
1574         return ret;
1575 }
1576
1577 /*
1578  * This functions updates i_blocks+i_bytes fields and quota information
1579  * (together with appropriate checks).
1580  *
1581  * NOTE: We absolutely rely on the fact that caller dirties the inode
1582  * (usually helpers in quotaops.h care about this) and holds a handle for
1583  * the current transaction so that dquot write and inode write go into the
1584  * same transaction.
1585  */
1586
1587 /*
1588  * This operation can block, but only after everything is updated
1589  */
1590 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
1591 {
1592         int cnt, ret = 0, index;
1593         struct dquot_warn warn[MAXQUOTAS];
1594         int reserve = flags & DQUOT_SPACE_RESERVE;
1595         struct dquot **dquots;
1596
1597         if (!dquot_active(inode)) {
1598                 if (reserve) {
1599                         spin_lock(&inode->i_lock);
1600                         *inode_reserved_space(inode) += number;
1601                         spin_unlock(&inode->i_lock);
1602                 } else {
1603                         inode_add_bytes(inode, number);
1604                 }
1605                 goto out;
1606         }
1607
1608         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1609                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1610
1611         dquots = i_dquot(inode);
1612         index = srcu_read_lock(&dquot_srcu);
1613         spin_lock(&dq_data_lock);
1614         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1615                 if (!dquots[cnt])
1616                         continue;
1617                 ret = check_bdq(dquots[cnt], number,
1618                                 !(flags & DQUOT_SPACE_WARN), &warn[cnt]);
1619                 if (ret && !(flags & DQUOT_SPACE_NOFAIL)) {
1620                         spin_unlock(&dq_data_lock);
1621                         goto out_flush_warn;
1622                 }
1623         }
1624         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1625                 if (!dquots[cnt])
1626                         continue;
1627                 if (reserve)
1628                         dquot_resv_space(dquots[cnt], number);
1629                 else
1630                         dquot_incr_space(dquots[cnt], number);
1631         }
1632         if (reserve) {
1633                 spin_lock(&inode->i_lock);
1634                 *inode_reserved_space(inode) += number;
1635                 spin_unlock(&inode->i_lock);
1636         } else {
1637                 inode_add_bytes(inode, number);
1638         }
1639         spin_unlock(&dq_data_lock);
1640
1641         if (reserve)
1642                 goto out_flush_warn;
1643         mark_all_dquot_dirty(dquots);
1644 out_flush_warn:
1645         srcu_read_unlock(&dquot_srcu, index);
1646         flush_warnings(warn);
1647 out:
1648         return ret;
1649 }
1650 EXPORT_SYMBOL(__dquot_alloc_space);
1651
1652 /*
1653  * This operation can block, but only after everything is updated
1654  */
1655 int dquot_alloc_inode(struct inode *inode)
1656 {
1657         int cnt, ret = 0, index;
1658         struct dquot_warn warn[MAXQUOTAS];
1659         struct dquot * const *dquots;
1660
1661         if (!dquot_active(inode))
1662                 return 0;
1663         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1664                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1665
1666         dquots = i_dquot(inode);
1667         index = srcu_read_lock(&dquot_srcu);
1668         spin_lock(&dq_data_lock);
1669         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1670                 if (!dquots[cnt])
1671                         continue;
1672                 ret = check_idq(dquots[cnt], 1, &warn[cnt]);
1673                 if (ret)
1674                         goto warn_put_all;
1675         }
1676
1677         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1678                 if (!dquots[cnt])
1679                         continue;
1680                 dquot_incr_inodes(dquots[cnt], 1);
1681         }
1682
1683 warn_put_all:
1684         spin_unlock(&dq_data_lock);
1685         if (ret == 0)
1686                 mark_all_dquot_dirty(dquots);
1687         srcu_read_unlock(&dquot_srcu, index);
1688         flush_warnings(warn);
1689         return ret;
1690 }
1691 EXPORT_SYMBOL(dquot_alloc_inode);
1692
1693 /*
1694  * Convert in-memory reserved quotas to real consumed quotas
1695  */
1696 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
1697 {
1698         struct dquot **dquots;
1699         int cnt, index;
1700
1701         if (!dquot_active(inode)) {
1702                 spin_lock(&inode->i_lock);
1703                 *inode_reserved_space(inode) -= number;
1704                 __inode_add_bytes(inode, number);
1705                 spin_unlock(&inode->i_lock);
1706                 return 0;
1707         }
1708
1709         dquots = i_dquot(inode);
1710         index = srcu_read_lock(&dquot_srcu);
1711         spin_lock(&dq_data_lock);
1712         /* Claim reserved quotas to allocated quotas */
1713         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1714                 if (dquots[cnt]) {
1715                         struct dquot *dquot = dquots[cnt];
1716
1717                         if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number))
1718                                 number = dquot->dq_dqb.dqb_rsvspace;
1719                         dquot->dq_dqb.dqb_curspace += number;
1720                         dquot->dq_dqb.dqb_rsvspace -= number;
1721                 }
1722         }
1723         /* Update inode bytes */
1724         spin_lock(&inode->i_lock);
1725         *inode_reserved_space(inode) -= number;
1726         __inode_add_bytes(inode, number);
1727         spin_unlock(&inode->i_lock);
1728         spin_unlock(&dq_data_lock);
1729         mark_all_dquot_dirty(dquots);
1730         srcu_read_unlock(&dquot_srcu, index);
1731         return 0;
1732 }
1733 EXPORT_SYMBOL(dquot_claim_space_nodirty);
1734
1735 /*
1736  * Convert allocated space back to in-memory reserved quotas
1737  */
1738 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number)
1739 {
1740         struct dquot **dquots;
1741         int cnt, index;
1742
1743         if (!dquot_active(inode)) {
1744                 spin_lock(&inode->i_lock);
1745                 *inode_reserved_space(inode) += number;
1746                 __inode_sub_bytes(inode, number);
1747                 spin_unlock(&inode->i_lock);
1748                 return;
1749         }
1750
1751         dquots = i_dquot(inode);
1752         index = srcu_read_lock(&dquot_srcu);
1753         spin_lock(&dq_data_lock);
1754         /* Claim reserved quotas to allocated quotas */
1755         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1756                 if (dquots[cnt]) {
1757                         struct dquot *dquot = dquots[cnt];
1758
1759                         if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number))
1760                                 number = dquot->dq_dqb.dqb_curspace;
1761                         dquot->dq_dqb.dqb_rsvspace += number;
1762                         dquot->dq_dqb.dqb_curspace -= number;
1763                 }
1764         }
1765         /* Update inode bytes */
1766         spin_lock(&inode->i_lock);
1767         *inode_reserved_space(inode) += number;
1768         __inode_sub_bytes(inode, number);
1769         spin_unlock(&inode->i_lock);
1770         spin_unlock(&dq_data_lock);
1771         mark_all_dquot_dirty(dquots);
1772         srcu_read_unlock(&dquot_srcu, index);
1773         return;
1774 }
1775 EXPORT_SYMBOL(dquot_reclaim_space_nodirty);
1776
1777 /*
1778  * This operation can block, but only after everything is updated
1779  */
1780 void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
1781 {
1782         unsigned int cnt;
1783         struct dquot_warn warn[MAXQUOTAS];
1784         struct dquot **dquots;
1785         int reserve = flags & DQUOT_SPACE_RESERVE, index;
1786
1787         if (!dquot_active(inode)) {
1788                 if (reserve) {
1789                         spin_lock(&inode->i_lock);
1790                         *inode_reserved_space(inode) -= number;
1791                         spin_unlock(&inode->i_lock);
1792                 } else {
1793                         inode_sub_bytes(inode, number);
1794                 }
1795                 return;
1796         }
1797
1798         dquots = i_dquot(inode);
1799         index = srcu_read_lock(&dquot_srcu);
1800         spin_lock(&dq_data_lock);
1801         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1802                 int wtype;
1803
1804                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1805                 if (!dquots[cnt])
1806                         continue;
1807                 wtype = info_bdq_free(dquots[cnt], number);
1808                 if (wtype != QUOTA_NL_NOWARN)
1809                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1810                 if (reserve)
1811                         dquot_free_reserved_space(dquots[cnt], number);
1812                 else
1813                         dquot_decr_space(dquots[cnt], number);
1814         }
1815         if (reserve) {
1816                 spin_lock(&inode->i_lock);
1817                 *inode_reserved_space(inode) -= number;
1818                 spin_unlock(&inode->i_lock);
1819         } else {
1820                 inode_sub_bytes(inode, number);
1821         }
1822         spin_unlock(&dq_data_lock);
1823
1824         if (reserve)
1825                 goto out_unlock;
1826         mark_all_dquot_dirty(dquots);
1827 out_unlock:
1828         srcu_read_unlock(&dquot_srcu, index);
1829         flush_warnings(warn);
1830 }
1831 EXPORT_SYMBOL(__dquot_free_space);
1832
1833 /*
1834  * This operation can block, but only after everything is updated
1835  */
1836 void dquot_free_inode(struct inode *inode)
1837 {
1838         unsigned int cnt;
1839         struct dquot_warn warn[MAXQUOTAS];
1840         struct dquot * const *dquots;
1841         int index;
1842
1843         if (!dquot_active(inode))
1844                 return;
1845
1846         dquots = i_dquot(inode);
1847         index = srcu_read_lock(&dquot_srcu);
1848         spin_lock(&dq_data_lock);
1849         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1850                 int wtype;
1851
1852                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1853                 if (!dquots[cnt])
1854                         continue;
1855                 wtype = info_idq_free(dquots[cnt], 1);
1856                 if (wtype != QUOTA_NL_NOWARN)
1857                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1858                 dquot_decr_inodes(dquots[cnt], 1);
1859         }
1860         spin_unlock(&dq_data_lock);
1861         mark_all_dquot_dirty(dquots);
1862         srcu_read_unlock(&dquot_srcu, index);
1863         flush_warnings(warn);
1864 }
1865 EXPORT_SYMBOL(dquot_free_inode);
1866
1867 /*
1868  * Transfer the number of inode and blocks from one diskquota to an other.
1869  * On success, dquot references in transfer_to are consumed and references
1870  * to original dquots that need to be released are placed there. On failure,
1871  * references are kept untouched.
1872  *
1873  * This operation can block, but only after everything is updated
1874  * A transaction must be started when entering this function.
1875  *
1876  * We are holding reference on transfer_from & transfer_to, no need to
1877  * protect them by srcu_read_lock().
1878  */
1879 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
1880 {
1881         qsize_t space, cur_space;
1882         qsize_t rsv_space = 0;
1883         qsize_t inode_usage = 1;
1884         struct dquot *transfer_from[MAXQUOTAS] = {};
1885         int cnt, ret = 0;
1886         char is_valid[MAXQUOTAS] = {};
1887         struct dquot_warn warn_to[MAXQUOTAS];
1888         struct dquot_warn warn_from_inodes[MAXQUOTAS];
1889         struct dquot_warn warn_from_space[MAXQUOTAS];
1890
1891         if (IS_NOQUOTA(inode))
1892                 return 0;
1893
1894         if (inode->i_sb->dq_op->get_inode_usage) {
1895                 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage);
1896                 if (ret)
1897                         return ret;
1898         }
1899
1900         /* Initialize the arrays */
1901         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1902                 warn_to[cnt].w_type = QUOTA_NL_NOWARN;
1903                 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN;
1904                 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN;
1905         }
1906
1907         spin_lock(&dq_data_lock);
1908         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1909                 spin_unlock(&dq_data_lock);
1910                 return 0;
1911         }
1912         cur_space = inode_get_bytes(inode);
1913         rsv_space = inode_get_rsv_space(inode);
1914         space = cur_space + rsv_space;
1915         /* Build the transfer_from list and check the limits */
1916         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1917                 /*
1918                  * Skip changes for same uid or gid or for turned off quota-type.
1919                  */
1920                 if (!transfer_to[cnt])
1921                         continue;
1922                 /* Avoid races with quotaoff() */
1923                 if (!sb_has_quota_active(inode->i_sb, cnt))
1924                         continue;
1925                 is_valid[cnt] = 1;
1926                 transfer_from[cnt] = i_dquot(inode)[cnt];
1927                 ret = check_idq(transfer_to[cnt], inode_usage, &warn_to[cnt]);
1928                 if (ret)
1929                         goto over_quota;
1930                 ret = check_bdq(transfer_to[cnt], space, 0, &warn_to[cnt]);
1931                 if (ret)
1932                         goto over_quota;
1933         }
1934
1935         /*
1936          * Finally perform the needed transfer from transfer_from to transfer_to
1937          */
1938         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1939                 if (!is_valid[cnt])
1940                         continue;
1941                 /* Due to IO error we might not have transfer_from[] structure */
1942                 if (transfer_from[cnt]) {
1943                         int wtype;
1944                         wtype = info_idq_free(transfer_from[cnt], inode_usage);
1945                         if (wtype != QUOTA_NL_NOWARN)
1946                                 prepare_warning(&warn_from_inodes[cnt],
1947                                                 transfer_from[cnt], wtype);
1948                         wtype = info_bdq_free(transfer_from[cnt], space);
1949                         if (wtype != QUOTA_NL_NOWARN)
1950                                 prepare_warning(&warn_from_space[cnt],
1951                                                 transfer_from[cnt], wtype);
1952                         dquot_decr_inodes(transfer_from[cnt], inode_usage);
1953                         dquot_decr_space(transfer_from[cnt], cur_space);
1954                         dquot_free_reserved_space(transfer_from[cnt],
1955                                                   rsv_space);
1956                 }
1957
1958                 dquot_incr_inodes(transfer_to[cnt], inode_usage);
1959                 dquot_incr_space(transfer_to[cnt], cur_space);
1960                 dquot_resv_space(transfer_to[cnt], rsv_space);
1961
1962                 i_dquot(inode)[cnt] = transfer_to[cnt];
1963         }
1964         spin_unlock(&dq_data_lock);
1965
1966         mark_all_dquot_dirty(transfer_from);
1967         mark_all_dquot_dirty(transfer_to);
1968         flush_warnings(warn_to);
1969         flush_warnings(warn_from_inodes);
1970         flush_warnings(warn_from_space);
1971         /* Pass back references to put */
1972         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1973                 if (is_valid[cnt])
1974                         transfer_to[cnt] = transfer_from[cnt];
1975         return 0;
1976 over_quota:
1977         spin_unlock(&dq_data_lock);
1978         flush_warnings(warn_to);
1979         return ret;
1980 }
1981 EXPORT_SYMBOL(__dquot_transfer);
1982
1983 /* Wrapper for transferring ownership of an inode for uid/gid only
1984  * Called from FSXXX_setattr()
1985  */
1986 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1987 {
1988         struct dquot *transfer_to[MAXQUOTAS] = {};
1989         struct dquot *dquot;
1990         struct super_block *sb = inode->i_sb;
1991         int ret;
1992
1993         if (!dquot_active(inode))
1994                 return 0;
1995
1996         if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){
1997                 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid));
1998                 if (IS_ERR(dquot)) {
1999                         if (PTR_ERR(dquot) != -ESRCH) {
2000                                 ret = PTR_ERR(dquot);
2001                                 goto out_put;
2002                         }
2003                         dquot = NULL;
2004                 }
2005                 transfer_to[USRQUOTA] = dquot;
2006         }
2007         if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){
2008                 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid));
2009                 if (IS_ERR(dquot)) {
2010                         if (PTR_ERR(dquot) != -ESRCH) {
2011                                 ret = PTR_ERR(dquot);
2012                                 goto out_put;
2013                         }
2014                         dquot = NULL;
2015                 }
2016                 transfer_to[GRPQUOTA] = dquot;
2017         }
2018         ret = __dquot_transfer(inode, transfer_to);
2019 out_put:
2020         dqput_all(transfer_to);
2021         return ret;
2022 }
2023 EXPORT_SYMBOL(dquot_transfer);
2024
2025 /*
2026  * Write info of quota file to disk
2027  */
2028 int dquot_commit_info(struct super_block *sb, int type)
2029 {
2030         struct quota_info *dqopt = sb_dqopt(sb);
2031
2032         return dqopt->ops[type]->write_file_info(sb, type);
2033 }
2034 EXPORT_SYMBOL(dquot_commit_info);
2035
2036 int dquot_get_next_id(struct super_block *sb, struct kqid *qid)
2037 {
2038         struct quota_info *dqopt = sb_dqopt(sb);
2039
2040         if (!sb_has_quota_active(sb, qid->type))
2041                 return -ESRCH;
2042         if (!dqopt->ops[qid->type]->get_next_id)
2043                 return -ENOSYS;
2044         return dqopt->ops[qid->type]->get_next_id(sb, qid);
2045 }
2046 EXPORT_SYMBOL(dquot_get_next_id);
2047
2048 /*
2049  * Definitions of diskquota operations.
2050  */
2051 const struct dquot_operations dquot_operations = {
2052         .write_dquot    = dquot_commit,
2053         .acquire_dquot  = dquot_acquire,
2054         .release_dquot  = dquot_release,
2055         .mark_dirty     = dquot_mark_dquot_dirty,
2056         .write_info     = dquot_commit_info,
2057         .alloc_dquot    = dquot_alloc,
2058         .destroy_dquot  = dquot_destroy,
2059         .get_next_id    = dquot_get_next_id,
2060 };
2061 EXPORT_SYMBOL(dquot_operations);
2062
2063 /*
2064  * Generic helper for ->open on filesystems supporting disk quotas.
2065  */
2066 int dquot_file_open(struct inode *inode, struct file *file)
2067 {
2068         int error;
2069
2070         error = generic_file_open(inode, file);
2071         if (!error && (file->f_mode & FMODE_WRITE))
2072                 dquot_initialize(inode);
2073         return error;
2074 }
2075 EXPORT_SYMBOL(dquot_file_open);
2076
2077 /*
2078  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
2079  */
2080 int dquot_disable(struct super_block *sb, int type, unsigned int flags)
2081 {
2082         int cnt, ret = 0;
2083         struct quota_info *dqopt = sb_dqopt(sb);
2084         struct inode *toputinode[MAXQUOTAS];
2085
2086         /* s_umount should be held in exclusive mode */
2087         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2088                 up_read(&sb->s_umount);
2089
2090         /* Cannot turn off usage accounting without turning off limits, or
2091          * suspend quotas and simultaneously turn quotas off. */
2092         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
2093             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
2094             DQUOT_USAGE_ENABLED)))
2095                 return -EINVAL;
2096
2097         /*
2098          * Skip everything if there's nothing to do. We have to do this because
2099          * sometimes we are called when fill_super() failed and calling
2100          * sync_fs() in such cases does no good.
2101          */
2102         if (!sb_any_quota_loaded(sb))
2103                 return 0;
2104
2105         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2106                 toputinode[cnt] = NULL;
2107                 if (type != -1 && cnt != type)
2108                         continue;
2109                 if (!sb_has_quota_loaded(sb, cnt))
2110                         continue;
2111
2112                 if (flags & DQUOT_SUSPENDED) {
2113                         spin_lock(&dq_state_lock);
2114                         dqopt->flags |=
2115                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
2116                         spin_unlock(&dq_state_lock);
2117                 } else {
2118                         spin_lock(&dq_state_lock);
2119                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
2120                         /* Turning off suspended quotas? */
2121                         if (!sb_has_quota_loaded(sb, cnt) &&
2122                             sb_has_quota_suspended(sb, cnt)) {
2123                                 dqopt->flags &= ~dquot_state_flag(
2124                                                         DQUOT_SUSPENDED, cnt);
2125                                 spin_unlock(&dq_state_lock);
2126                                 iput(dqopt->files[cnt]);
2127                                 dqopt->files[cnt] = NULL;
2128                                 continue;
2129                         }
2130                         spin_unlock(&dq_state_lock);
2131                 }
2132
2133                 /* We still have to keep quota loaded? */
2134                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
2135                         continue;
2136
2137                 /* Note: these are blocking operations */
2138                 drop_dquot_ref(sb, cnt);
2139                 invalidate_dquots(sb, cnt);
2140                 /*
2141                  * Now all dquots should be invalidated, all writes done so we
2142                  * should be only users of the info. No locks needed.
2143                  */
2144                 if (info_dirty(&dqopt->info[cnt]))
2145                         sb->dq_op->write_info(sb, cnt);
2146                 if (dqopt->ops[cnt]->free_file_info)
2147                         dqopt->ops[cnt]->free_file_info(sb, cnt);
2148                 put_quota_format(dqopt->info[cnt].dqi_format);
2149
2150                 toputinode[cnt] = dqopt->files[cnt];
2151                 if (!sb_has_quota_loaded(sb, cnt))
2152                         dqopt->files[cnt] = NULL;
2153                 dqopt->info[cnt].dqi_flags = 0;
2154                 dqopt->info[cnt].dqi_igrace = 0;
2155                 dqopt->info[cnt].dqi_bgrace = 0;
2156                 dqopt->ops[cnt] = NULL;
2157         }
2158
2159         /* Skip syncing and setting flags if quota files are hidden */
2160         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
2161                 goto put_inodes;
2162
2163         /* Sync the superblock so that buffers with quota data are written to
2164          * disk (and so userspace sees correct data afterwards). */
2165         if (sb->s_op->sync_fs)
2166                 sb->s_op->sync_fs(sb, 1);
2167         sync_blockdev(sb->s_bdev);
2168         /* Now the quota files are just ordinary files and we can set the
2169          * inode flags back. Moreover we discard the pagecache so that
2170          * userspace sees the writes we did bypassing the pagecache. We
2171          * must also discard the blockdev buffers so that we see the
2172          * changes done by userspace on the next quotaon() */
2173         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2174                 /* This can happen when suspending quotas on remount-ro... */
2175                 if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) {
2176                         inode_lock(toputinode[cnt]);
2177                         toputinode[cnt]->i_flags &= ~S_NOQUOTA;
2178                         truncate_inode_pages(&toputinode[cnt]->i_data, 0);
2179                         inode_unlock(toputinode[cnt]);
2180                         mark_inode_dirty_sync(toputinode[cnt]);
2181                 }
2182         if (sb->s_bdev)
2183                 invalidate_bdev(sb->s_bdev);
2184 put_inodes:
2185         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2186                 if (toputinode[cnt]) {
2187                         /* On remount RO, we keep the inode pointer so that we
2188                          * can reenable quota on the subsequent remount RW. We
2189                          * have to check 'flags' variable and not use sb_has_
2190                          * function because another quotaon / quotaoff could
2191                          * change global state before we got here. We refuse
2192                          * to suspend quotas when there is pending delete on
2193                          * the quota file... */
2194                         if (!(flags & DQUOT_SUSPENDED))
2195                                 iput(toputinode[cnt]);
2196                         else if (!toputinode[cnt]->i_nlink)
2197                                 ret = -EBUSY;
2198                 }
2199         return ret;
2200 }
2201 EXPORT_SYMBOL(dquot_disable);
2202
2203 int dquot_quota_off(struct super_block *sb, int type)
2204 {
2205         return dquot_disable(sb, type,
2206                              DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2207 }
2208 EXPORT_SYMBOL(dquot_quota_off);
2209
2210 /*
2211  *      Turn quotas on on a device
2212  */
2213
2214 /*
2215  * Helper function to turn quotas on when we already have the inode of
2216  * quota file and no quota information is loaded.
2217  */
2218 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2219         unsigned int flags)
2220 {
2221         struct quota_format_type *fmt = find_quota_format(format_id);
2222         struct super_block *sb = inode->i_sb;
2223         struct quota_info *dqopt = sb_dqopt(sb);
2224         int error;
2225
2226         if (!fmt)
2227                 return -ESRCH;
2228         if (!S_ISREG(inode->i_mode)) {
2229                 error = -EACCES;
2230                 goto out_fmt;
2231         }
2232         if (IS_RDONLY(inode)) {
2233                 error = -EROFS;
2234                 goto out_fmt;
2235         }
2236         if (!sb->s_op->quota_write || !sb->s_op->quota_read ||
2237             (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) {
2238                 error = -EINVAL;
2239                 goto out_fmt;
2240         }
2241         /* Filesystems outside of init_user_ns not yet supported */
2242         if (sb->s_user_ns != &init_user_ns) {
2243                 error = -EINVAL;
2244                 goto out_fmt;
2245         }
2246         /* Usage always has to be set... */
2247         if (!(flags & DQUOT_USAGE_ENABLED)) {
2248                 error = -EINVAL;
2249                 goto out_fmt;
2250         }
2251         if (sb_has_quota_loaded(sb, type)) {
2252                 error = -EBUSY;
2253                 goto out_fmt;
2254         }
2255
2256         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2257                 /* As we bypass the pagecache we must now flush all the
2258                  * dirty data and invalidate caches so that kernel sees
2259                  * changes from userspace. It is not enough to just flush
2260                  * the quota file since if blocksize < pagesize, invalidation
2261                  * of the cache could fail because of other unrelated dirty
2262                  * data */
2263                 sync_filesystem(sb);
2264                 invalidate_bdev(sb->s_bdev);
2265         }
2266
2267         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2268                 /* We don't want quota and atime on quota files (deadlocks
2269                  * possible) Also nobody should write to the file - we use
2270                  * special IO operations which ignore the immutable bit. */
2271                 inode_lock(inode);
2272                 inode->i_flags |= S_NOQUOTA;
2273                 inode_unlock(inode);
2274                 /*
2275                  * When S_NOQUOTA is set, remove dquot references as no more
2276                  * references can be added
2277                  */
2278                 __dquot_drop(inode);
2279         }
2280
2281         error = -EIO;
2282         dqopt->files[type] = igrab(inode);
2283         if (!dqopt->files[type])
2284                 goto out_file_flags;
2285         error = -EINVAL;
2286         if (!fmt->qf_ops->check_quota_file(sb, type))
2287                 goto out_file_init;
2288
2289         dqopt->ops[type] = fmt->qf_ops;
2290         dqopt->info[type].dqi_format = fmt;
2291         dqopt->info[type].dqi_fmt_id = format_id;
2292         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2293         error = dqopt->ops[type]->read_file_info(sb, type);
2294         if (error < 0)
2295                 goto out_file_init;
2296         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) {
2297                 spin_lock(&dq_data_lock);
2298                 dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
2299                 spin_unlock(&dq_data_lock);
2300         }
2301         spin_lock(&dq_state_lock);
2302         dqopt->flags |= dquot_state_flag(flags, type);
2303         spin_unlock(&dq_state_lock);
2304
2305         add_dquot_ref(sb, type);
2306
2307         return 0;
2308
2309 out_file_init:
2310         dqopt->files[type] = NULL;
2311         iput(inode);
2312 out_file_flags:
2313         inode_lock(inode);
2314         inode->i_flags &= ~S_NOQUOTA;
2315         inode_unlock(inode);
2316 out_fmt:
2317         put_quota_format(fmt);
2318
2319         return error; 
2320 }
2321
2322 /* Reenable quotas on remount RW */
2323 int dquot_resume(struct super_block *sb, int type)
2324 {
2325         struct quota_info *dqopt = sb_dqopt(sb);
2326         struct inode *inode;
2327         int ret = 0, cnt;
2328         unsigned int flags;
2329
2330         /* s_umount should be held in exclusive mode */
2331         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2332                 up_read(&sb->s_umount);
2333
2334         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2335                 if (type != -1 && cnt != type)
2336                         continue;
2337                 if (!sb_has_quota_suspended(sb, cnt))
2338                         continue;
2339
2340                 inode = dqopt->files[cnt];
2341                 dqopt->files[cnt] = NULL;
2342                 spin_lock(&dq_state_lock);
2343                 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2344                                                         DQUOT_LIMITS_ENABLED,
2345                                                         cnt);
2346                 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
2347                 spin_unlock(&dq_state_lock);
2348
2349                 flags = dquot_generic_flag(flags, cnt);
2350                 ret = vfs_load_quota_inode(inode, cnt,
2351                                 dqopt->info[cnt].dqi_fmt_id, flags);
2352                 iput(inode);
2353         }
2354
2355         return ret;
2356 }
2357 EXPORT_SYMBOL(dquot_resume);
2358
2359 int dquot_quota_on(struct super_block *sb, int type, int format_id,
2360                    const struct path *path)
2361 {
2362         int error = security_quota_on(path->dentry);
2363         if (error)
2364                 return error;
2365         /* Quota file not on the same filesystem? */
2366         if (path->dentry->d_sb != sb)
2367                 error = -EXDEV;
2368         else
2369                 error = vfs_load_quota_inode(d_inode(path->dentry), type,
2370                                              format_id, DQUOT_USAGE_ENABLED |
2371                                              DQUOT_LIMITS_ENABLED);
2372         return error;
2373 }
2374 EXPORT_SYMBOL(dquot_quota_on);
2375
2376 /*
2377  * More powerful function for turning on quotas allowing setting
2378  * of individual quota flags
2379  */
2380 int dquot_enable(struct inode *inode, int type, int format_id,
2381                  unsigned int flags)
2382 {
2383         struct super_block *sb = inode->i_sb;
2384
2385         /* Just unsuspend quotas? */
2386         BUG_ON(flags & DQUOT_SUSPENDED);
2387         /* s_umount should be held in exclusive mode */
2388         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2389                 up_read(&sb->s_umount);
2390
2391         if (!flags)
2392                 return 0;
2393         /* Just updating flags needed? */
2394         if (sb_has_quota_loaded(sb, type)) {
2395                 if (flags & DQUOT_USAGE_ENABLED &&
2396                     sb_has_quota_usage_enabled(sb, type))
2397                         return -EBUSY;
2398                 if (flags & DQUOT_LIMITS_ENABLED &&
2399                     sb_has_quota_limits_enabled(sb, type))
2400                         return -EBUSY;
2401                 spin_lock(&dq_state_lock);
2402                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2403                 spin_unlock(&dq_state_lock);
2404                 return 0;
2405         }
2406
2407         return vfs_load_quota_inode(inode, type, format_id, flags);
2408 }
2409 EXPORT_SYMBOL(dquot_enable);
2410
2411 /*
2412  * This function is used when filesystem needs to initialize quotas
2413  * during mount time.
2414  */
2415 int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
2416                 int format_id, int type)
2417 {
2418         struct dentry *dentry;
2419         int error;
2420
2421         dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name));
2422         if (IS_ERR(dentry))
2423                 return PTR_ERR(dentry);
2424
2425         if (d_really_is_negative(dentry)) {
2426                 error = -ENOENT;
2427                 goto out;
2428         }
2429
2430         error = security_quota_on(dentry);
2431         if (!error)
2432                 error = vfs_load_quota_inode(d_inode(dentry), type, format_id,
2433                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2434
2435 out:
2436         dput(dentry);
2437         return error;
2438 }
2439 EXPORT_SYMBOL(dquot_quota_on_mount);
2440
2441 static int dquot_quota_enable(struct super_block *sb, unsigned int flags)
2442 {
2443         int ret;
2444         int type;
2445         struct quota_info *dqopt = sb_dqopt(sb);
2446
2447         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
2448                 return -ENOSYS;
2449         /* Accounting cannot be turned on while fs is mounted */
2450         flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT);
2451         if (!flags)
2452                 return -EINVAL;
2453         for (type = 0; type < MAXQUOTAS; type++) {
2454                 if (!(flags & qtype_enforce_flag(type)))
2455                         continue;
2456                 /* Can't enforce without accounting */
2457                 if (!sb_has_quota_usage_enabled(sb, type))
2458                         return -EINVAL;
2459                 ret = dquot_enable(dqopt->files[type], type,
2460                                    dqopt->info[type].dqi_fmt_id,
2461                                    DQUOT_LIMITS_ENABLED);
2462                 if (ret < 0)
2463                         goto out_err;
2464         }
2465         return 0;
2466 out_err:
2467         /* Backout enforcement enablement we already did */
2468         for (type--; type >= 0; type--)  {
2469                 if (flags & qtype_enforce_flag(type))
2470                         dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
2471         }
2472         /* Error code translation for better compatibility with XFS */
2473         if (ret == -EBUSY)
2474                 ret = -EEXIST;
2475         return ret;
2476 }
2477
2478 static int dquot_quota_disable(struct super_block *sb, unsigned int flags)
2479 {
2480         int ret;
2481         int type;
2482         struct quota_info *dqopt = sb_dqopt(sb);
2483
2484         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
2485                 return -ENOSYS;
2486         /*
2487          * We don't support turning off accounting via quotactl. In principle
2488          * quota infrastructure can do this but filesystems don't expect
2489          * userspace to be able to do it.
2490          */
2491         if (flags &
2492                   (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT))
2493                 return -EOPNOTSUPP;
2494
2495         /* Filter out limits not enabled */
2496         for (type = 0; type < MAXQUOTAS; type++)
2497                 if (!sb_has_quota_limits_enabled(sb, type))
2498                         flags &= ~qtype_enforce_flag(type);
2499         /* Nothing left? */
2500         if (!flags)
2501                 return -EEXIST;
2502         for (type = 0; type < MAXQUOTAS; type++) {
2503                 if (flags & qtype_enforce_flag(type)) {
2504                         ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
2505                         if (ret < 0)
2506                                 goto out_err;
2507                 }
2508         }
2509         return 0;
2510 out_err:
2511         /* Backout enforcement disabling we already did */
2512         for (type--; type >= 0; type--)  {
2513                 if (flags & qtype_enforce_flag(type))
2514                         dquot_enable(dqopt->files[type], type,
2515                                      dqopt->info[type].dqi_fmt_id,
2516                                      DQUOT_LIMITS_ENABLED);
2517         }
2518         return ret;
2519 }
2520
2521 /* Generic routine for getting common part of quota structure */
2522 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di)
2523 {
2524         struct mem_dqblk *dm = &dquot->dq_dqb;
2525
2526         memset(di, 0, sizeof(*di));
2527         spin_lock(&dq_data_lock);
2528         di->d_spc_hardlimit = dm->dqb_bhardlimit;
2529         di->d_spc_softlimit = dm->dqb_bsoftlimit;
2530         di->d_ino_hardlimit = dm->dqb_ihardlimit;
2531         di->d_ino_softlimit = dm->dqb_isoftlimit;
2532         di->d_space = dm->dqb_curspace + dm->dqb_rsvspace;
2533         di->d_ino_count = dm->dqb_curinodes;
2534         di->d_spc_timer = dm->dqb_btime;
2535         di->d_ino_timer = dm->dqb_itime;
2536         spin_unlock(&dq_data_lock);
2537 }
2538
2539 int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
2540                     struct qc_dqblk *di)
2541 {
2542         struct dquot *dquot;
2543
2544         dquot = dqget(sb, qid);
2545         if (IS_ERR(dquot))
2546                 return PTR_ERR(dquot);
2547         do_get_dqblk(dquot, di);
2548         dqput(dquot);
2549
2550         return 0;
2551 }
2552 EXPORT_SYMBOL(dquot_get_dqblk);
2553
2554 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid,
2555                          struct qc_dqblk *di)
2556 {
2557         struct dquot *dquot;
2558         int err;
2559
2560         if (!sb->dq_op->get_next_id)
2561                 return -ENOSYS;
2562         err = sb->dq_op->get_next_id(sb, qid);
2563         if (err < 0)
2564                 return err;
2565         dquot = dqget(sb, *qid);
2566         if (IS_ERR(dquot))
2567                 return PTR_ERR(dquot);
2568         do_get_dqblk(dquot, di);
2569         dqput(dquot);
2570
2571         return 0;
2572 }
2573 EXPORT_SYMBOL(dquot_get_next_dqblk);
2574
2575 #define VFS_QC_MASK \
2576         (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \
2577          QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \
2578          QC_SPC_TIMER | QC_INO_TIMER)
2579
2580 /* Generic routine for setting common part of quota structure */
2581 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di)
2582 {
2583         struct mem_dqblk *dm = &dquot->dq_dqb;
2584         int check_blim = 0, check_ilim = 0;
2585         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
2586
2587         if (di->d_fieldmask & ~VFS_QC_MASK)
2588                 return -EINVAL;
2589
2590         if (((di->d_fieldmask & QC_SPC_SOFT) &&
2591              di->d_spc_softlimit > dqi->dqi_max_spc_limit) ||
2592             ((di->d_fieldmask & QC_SPC_HARD) &&
2593              di->d_spc_hardlimit > dqi->dqi_max_spc_limit) ||
2594             ((di->d_fieldmask & QC_INO_SOFT) &&
2595              (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) ||
2596             ((di->d_fieldmask & QC_INO_HARD) &&
2597              (di->d_ino_hardlimit > dqi->dqi_max_ino_limit)))
2598                 return -ERANGE;
2599
2600         spin_lock(&dq_data_lock);
2601         if (di->d_fieldmask & QC_SPACE) {
2602                 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace;
2603                 check_blim = 1;
2604                 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2605         }
2606
2607         if (di->d_fieldmask & QC_SPC_SOFT)
2608                 dm->dqb_bsoftlimit = di->d_spc_softlimit;
2609         if (di->d_fieldmask & QC_SPC_HARD)
2610                 dm->dqb_bhardlimit = di->d_spc_hardlimit;
2611         if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) {
2612                 check_blim = 1;
2613                 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2614         }
2615
2616         if (di->d_fieldmask & QC_INO_COUNT) {
2617                 dm->dqb_curinodes = di->d_ino_count;
2618                 check_ilim = 1;
2619                 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2620         }
2621
2622         if (di->d_fieldmask & QC_INO_SOFT)
2623                 dm->dqb_isoftlimit = di->d_ino_softlimit;
2624         if (di->d_fieldmask & QC_INO_HARD)
2625                 dm->dqb_ihardlimit = di->d_ino_hardlimit;
2626         if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) {
2627                 check_ilim = 1;
2628                 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2629         }
2630
2631         if (di->d_fieldmask & QC_SPC_TIMER) {
2632                 dm->dqb_btime = di->d_spc_timer;
2633                 check_blim = 1;
2634                 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2635         }
2636
2637         if (di->d_fieldmask & QC_INO_TIMER) {
2638                 dm->dqb_itime = di->d_ino_timer;
2639                 check_ilim = 1;
2640                 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2641         }
2642
2643         if (check_blim) {
2644                 if (!dm->dqb_bsoftlimit ||
2645                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
2646                         dm->dqb_btime = 0;
2647                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2648                 } else if (!(di->d_fieldmask & QC_SPC_TIMER))
2649                         /* Set grace only if user hasn't provided his own... */
2650                         dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace;
2651         }
2652         if (check_ilim) {
2653                 if (!dm->dqb_isoftlimit ||
2654                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
2655                         dm->dqb_itime = 0;
2656                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2657                 } else if (!(di->d_fieldmask & QC_INO_TIMER))
2658                         /* Set grace only if user hasn't provided his own... */
2659                         dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace;
2660         }
2661         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2662             dm->dqb_isoftlimit)
2663                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2664         else
2665                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2666         spin_unlock(&dq_data_lock);
2667         mark_dquot_dirty(dquot);
2668
2669         return 0;
2670 }
2671
2672 int dquot_set_dqblk(struct super_block *sb, struct kqid qid,
2673                   struct qc_dqblk *di)
2674 {
2675         struct dquot *dquot;
2676         int rc;
2677
2678         dquot = dqget(sb, qid);
2679         if (IS_ERR(dquot)) {
2680                 rc = PTR_ERR(dquot);
2681                 goto out;
2682         }
2683         rc = do_set_dqblk(dquot, di);
2684         dqput(dquot);
2685 out:
2686         return rc;
2687 }
2688 EXPORT_SYMBOL(dquot_set_dqblk);
2689
2690 /* Generic routine for getting common part of quota file information */
2691 int dquot_get_state(struct super_block *sb, struct qc_state *state)
2692 {
2693         struct mem_dqinfo *mi;
2694         struct qc_type_state *tstate;
2695         struct quota_info *dqopt = sb_dqopt(sb);
2696         int type;
2697   
2698         memset(state, 0, sizeof(*state));
2699         for (type = 0; type < MAXQUOTAS; type++) {
2700                 if (!sb_has_quota_active(sb, type))
2701                         continue;
2702                 tstate = state->s_state + type;
2703                 mi = sb_dqopt(sb)->info + type;
2704                 tstate->flags = QCI_ACCT_ENABLED;
2705                 spin_lock(&dq_data_lock);
2706                 if (mi->dqi_flags & DQF_SYS_FILE)
2707                         tstate->flags |= QCI_SYSFILE;
2708                 if (mi->dqi_flags & DQF_ROOT_SQUASH)
2709                         tstate->flags |= QCI_ROOT_SQUASH;
2710                 if (sb_has_quota_limits_enabled(sb, type))
2711                         tstate->flags |= QCI_LIMITS_ENFORCED;
2712                 tstate->spc_timelimit = mi->dqi_bgrace;
2713                 tstate->ino_timelimit = mi->dqi_igrace;
2714                 tstate->ino = dqopt->files[type]->i_ino;
2715                 tstate->blocks = dqopt->files[type]->i_blocks;
2716                 tstate->nextents = 1;   /* We don't know... */
2717                 spin_unlock(&dq_data_lock);
2718         }
2719         return 0;
2720 }
2721 EXPORT_SYMBOL(dquot_get_state);
2722
2723 /* Generic routine for setting common part of quota file information */
2724 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii)
2725 {
2726         struct mem_dqinfo *mi;
2727         int err = 0;
2728
2729         if ((ii->i_fieldmask & QC_WARNS_MASK) ||
2730             (ii->i_fieldmask & QC_RT_SPC_TIMER))
2731                 return -EINVAL;
2732         if (!sb_has_quota_active(sb, type))
2733                 return -ESRCH;
2734         mi = sb_dqopt(sb)->info + type;
2735         if (ii->i_fieldmask & QC_FLAGS) {
2736                 if ((ii->i_flags & QCI_ROOT_SQUASH &&
2737                      mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD))
2738                         return -EINVAL;
2739         }
2740         spin_lock(&dq_data_lock);
2741         if (ii->i_fieldmask & QC_SPC_TIMER)
2742                 mi->dqi_bgrace = ii->i_spc_timelimit;
2743         if (ii->i_fieldmask & QC_INO_TIMER)
2744                 mi->dqi_igrace = ii->i_ino_timelimit;
2745         if (ii->i_fieldmask & QC_FLAGS) {
2746                 if (ii->i_flags & QCI_ROOT_SQUASH)
2747                         mi->dqi_flags |= DQF_ROOT_SQUASH;
2748                 else
2749                         mi->dqi_flags &= ~DQF_ROOT_SQUASH;
2750         }
2751         spin_unlock(&dq_data_lock);
2752         mark_info_dirty(sb, type);
2753         /* Force write to disk */
2754         sb->dq_op->write_info(sb, type);
2755         return err;
2756 }
2757 EXPORT_SYMBOL(dquot_set_dqinfo);
2758
2759 const struct quotactl_ops dquot_quotactl_sysfile_ops = {
2760         .quota_enable   = dquot_quota_enable,
2761         .quota_disable  = dquot_quota_disable,
2762         .quota_sync     = dquot_quota_sync,
2763         .get_state      = dquot_get_state,
2764         .set_info       = dquot_set_dqinfo,
2765         .get_dqblk      = dquot_get_dqblk,
2766         .get_nextdqblk  = dquot_get_next_dqblk,
2767         .set_dqblk      = dquot_set_dqblk
2768 };
2769 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);
2770
2771 static int do_proc_dqstats(struct ctl_table *table, int write,
2772                      void __user *buffer, size_t *lenp, loff_t *ppos)
2773 {
2774         unsigned int type = (int *)table->data - dqstats.stat;
2775
2776         /* Update global table */
2777         dqstats.stat[type] =
2778                         percpu_counter_sum_positive(&dqstats.counter[type]);
2779         return proc_dointvec(table, write, buffer, lenp, ppos);
2780 }
2781
2782 static struct ctl_table fs_dqstats_table[] = {
2783         {
2784                 .procname       = "lookups",
2785                 .data           = &dqstats.stat[DQST_LOOKUPS],
2786                 .maxlen         = sizeof(int),
2787                 .mode           = 0444,
2788                 .proc_handler   = do_proc_dqstats,
2789         },
2790         {
2791                 .procname       = "drops",
2792                 .data           = &dqstats.stat[DQST_DROPS],
2793                 .maxlen         = sizeof(int),
2794                 .mode           = 0444,
2795                 .proc_handler   = do_proc_dqstats,
2796         },
2797         {
2798                 .procname       = "reads",
2799                 .data           = &dqstats.stat[DQST_READS],
2800                 .maxlen         = sizeof(int),
2801                 .mode           = 0444,
2802                 .proc_handler   = do_proc_dqstats,
2803         },
2804         {
2805                 .procname       = "writes",
2806                 .data           = &dqstats.stat[DQST_WRITES],
2807                 .maxlen         = sizeof(int),
2808                 .mode           = 0444,
2809                 .proc_handler   = do_proc_dqstats,
2810         },
2811         {
2812                 .procname       = "cache_hits",
2813                 .data           = &dqstats.stat[DQST_CACHE_HITS],
2814                 .maxlen         = sizeof(int),
2815                 .mode           = 0444,
2816                 .proc_handler   = do_proc_dqstats,
2817         },
2818         {
2819                 .procname       = "allocated_dquots",
2820                 .data           = &dqstats.stat[DQST_ALLOC_DQUOTS],
2821                 .maxlen         = sizeof(int),
2822                 .mode           = 0444,
2823                 .proc_handler   = do_proc_dqstats,
2824         },
2825         {
2826                 .procname       = "free_dquots",
2827                 .data           = &dqstats.stat[DQST_FREE_DQUOTS],
2828                 .maxlen         = sizeof(int),
2829                 .mode           = 0444,
2830                 .proc_handler   = do_proc_dqstats,
2831         },
2832         {
2833                 .procname       = "syncs",
2834                 .data           = &dqstats.stat[DQST_SYNCS],
2835                 .maxlen         = sizeof(int),
2836                 .mode           = 0444,
2837                 .proc_handler   = do_proc_dqstats,
2838         },
2839 #ifdef CONFIG_PRINT_QUOTA_WARNING
2840         {
2841                 .procname       = "warnings",
2842                 .data           = &flag_print_warnings,
2843                 .maxlen         = sizeof(int),
2844                 .mode           = 0644,
2845                 .proc_handler   = proc_dointvec,
2846         },
2847 #endif
2848         { },
2849 };
2850
2851 static struct ctl_table fs_table[] = {
2852         {
2853                 .procname       = "quota",
2854                 .mode           = 0555,
2855                 .child          = fs_dqstats_table,
2856         },
2857         { },
2858 };
2859
2860 static struct ctl_table sys_table[] = {
2861         {
2862                 .procname       = "fs",
2863                 .mode           = 0555,
2864                 .child          = fs_table,
2865         },
2866         { },
2867 };
2868
2869 static int __init dquot_init(void)
2870 {
2871         int i, ret;
2872         unsigned long nr_hash, order;
2873
2874         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2875
2876         register_sysctl_table(sys_table);
2877
2878         dquot_cachep = kmem_cache_create("dquot",
2879                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2880                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2881                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2882                         NULL);
2883
2884         order = 0;
2885         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2886         if (!dquot_hash)
2887                 panic("Cannot create dquot hash table");
2888
2889         for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
2890                 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL);
2891                 if (ret)
2892                         panic("Cannot create dquot stat counters");
2893         }
2894
2895         /* Find power-of-two hlist_heads which can fit into allocation */
2896         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2897         dq_hash_bits = 0;
2898         do {
2899                 dq_hash_bits++;
2900         } while (nr_hash >> dq_hash_bits);
2901         dq_hash_bits--;
2902
2903         nr_hash = 1UL << dq_hash_bits;
2904         dq_hash_mask = nr_hash - 1;
2905         for (i = 0; i < nr_hash; i++)
2906                 INIT_HLIST_HEAD(dquot_hash + i);
2907
2908         pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld,"
2909                 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order));
2910
2911         register_shrinker(&dqcache_shrinker);
2912
2913         return 0;
2914 }
2915 fs_initcall(dquot_init);