Merge branch 'omap-for-v5.14/ti-sysc' into omap-for-v5.15/ti-sysc
[linux-2.6-microblaze.git] / fs / quota / dquot.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Implementation of the diskquota system for the LINUX operating system. QUOTA
4  * is implemented using the BSD system call interface as the means of
5  * communication with the user level. This file contains the generic routines
6  * called by the different filesystems on allocation of an inode or block.
7  * These routines take care of the administration needed to have a consistent
8  * diskquota tracking system. The ideas of both user and group quotas are based
9  * on the Melbourne quota system as used on BSD derived systems. The internal
10  * implementation is based on one of the several variants of the LINUX
11  * inode-subsystem with added complexity of the diskquota system.
12  *
13  * Author:      Marco van Wieringen <mvw@planets.elm.net>
14  *
15  * Fixes:   Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
16  *
17  *              Revised list management to avoid races
18  *              -- Bill Hawes, <whawes@star.net>, 9/98
19  *
20  *              Fixed races in dquot_transfer(), dqget() and dquot_alloc_...().
21  *              As the consequence the locking was moved from dquot_decr_...(),
22  *              dquot_incr_...() to calling functions.
23  *              invalidate_dquots() now writes modified dquots.
24  *              Serialized quota_off() and quota_on() for mount point.
25  *              Fixed a few bugs in grow_dquots().
26  *              Fixed deadlock in write_dquot() - we no longer account quotas on
27  *              quota files
28  *              remove_dquot_ref() moved to inode.c - it now traverses through inodes
29  *              add_dquot_ref() restarts after blocking
30  *              Added check for bogus uid and fixed check for group in quotactl.
31  *              Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99
32  *
33  *              Used struct list_head instead of own list struct
34  *              Invalidation of referenced dquots is no longer possible
35  *              Improved free_dquots list management
36  *              Quota and i_blocks are now updated in one place to avoid races
37  *              Warnings are now delayed so we won't block in critical section
38  *              Write updated not to require dquot lock
39  *              Jan Kara, <jack@suse.cz>, 9/2000
40  *
41  *              Added dynamic quota structure allocation
42  *              Jan Kara <jack@suse.cz> 12/2000
43  *
44  *              Rewritten quota interface. Implemented new quota format and
45  *              formats registering.
46  *              Jan Kara, <jack@suse.cz>, 2001,2002
47  *
48  *              New SMP locking.
49  *              Jan Kara, <jack@suse.cz>, 10/2002
50  *
51  *              Added journalled quota support, fix lock inversion problems
52  *              Jan Kara, <jack@suse.cz>, 2003,2004
53  *
54  * (C) Copyright 1994 - 1997 Marco van Wieringen
55  */
56
57 #include <linux/errno.h>
58 #include <linux/kernel.h>
59 #include <linux/fs.h>
60 #include <linux/mount.h>
61 #include <linux/mm.h>
62 #include <linux/time.h>
63 #include <linux/types.h>
64 #include <linux/string.h>
65 #include <linux/fcntl.h>
66 #include <linux/stat.h>
67 #include <linux/tty.h>
68 #include <linux/file.h>
69 #include <linux/slab.h>
70 #include <linux/sysctl.h>
71 #include <linux/init.h>
72 #include <linux/module.h>
73 #include <linux/proc_fs.h>
74 #include <linux/security.h>
75 #include <linux/sched.h>
76 #include <linux/cred.h>
77 #include <linux/kmod.h>
78 #include <linux/namei.h>
79 #include <linux/capability.h>
80 #include <linux/quotaops.h>
81 #include <linux/blkdev.h>
82 #include "../internal.h" /* ugh */
83
84 #include <linux/uaccess.h>
85
86 /*
87  * There are five quota SMP locks:
88  * * dq_list_lock protects all lists with quotas and quota formats.
89  * * dquot->dq_dqb_lock protects data from dq_dqb
90  * * inode->i_lock protects inode->i_blocks, i_bytes and also guards
91  *   consistency of dquot->dq_dqb with inode->i_blocks, i_bytes so that
92  *   dquot_transfer() can stabilize amount it transfers
93  * * dq_data_lock protects mem_dqinfo structures and modifications of dquot
94  *   pointers in the inode
95  * * dq_state_lock protects modifications of quota state (on quotaon and
96  *   quotaoff) and readers who care about latest values take it as well.
97  *
98  * The spinlock ordering is hence:
99  *   dq_data_lock > dq_list_lock > i_lock > dquot->dq_dqb_lock,
100  *   dq_list_lock > dq_state_lock
101  *
102  * Note that some things (eg. sb pointer, type, id) doesn't change during
103  * the life of the dquot structure and so needn't to be protected by a lock
104  *
105  * Operation accessing dquots via inode pointers are protected by dquot_srcu.
106  * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and
107  * synchronize_srcu(&dquot_srcu) is called after clearing pointers from
108  * inode and before dropping dquot references to avoid use of dquots after
109  * they are freed. dq_data_lock is used to serialize the pointer setting and
110  * clearing operations.
111  * Special care needs to be taken about S_NOQUOTA inode flag (marking that
112  * inode is a quota file). Functions adding pointers from inode to dquots have
113  * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they
114  * have to do all pointer modifications before dropping dq_data_lock. This makes
115  * sure they cannot race with quotaon which first sets S_NOQUOTA flag and
116  * then drops all pointers to dquots from an inode.
117  *
118  * Each dquot has its dq_lock mutex.  Dquot is locked when it is being read to
119  * memory (or space for it is being allocated) on the first dqget(), when it is
120  * being written out, and when it is being released on the last dqput(). The
121  * allocation and release operations are serialized by the dq_lock and by
122  * checking the use count in dquot_release().
123  *
124  * Lock ordering (including related VFS locks) is the following:
125  *   s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem
126  */
127
128 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
129 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
130 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
131 EXPORT_SYMBOL(dq_data_lock);
132 DEFINE_STATIC_SRCU(dquot_srcu);
133
134 static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq);
135
136 void __quota_error(struct super_block *sb, const char *func,
137                    const char *fmt, ...)
138 {
139         if (printk_ratelimit()) {
140                 va_list args;
141                 struct va_format vaf;
142
143                 va_start(args, fmt);
144
145                 vaf.fmt = fmt;
146                 vaf.va = &args;
147
148                 printk(KERN_ERR "Quota error (device %s): %s: %pV\n",
149                        sb->s_id, func, &vaf);
150
151                 va_end(args);
152         }
153 }
154 EXPORT_SYMBOL(__quota_error);
155
156 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING)
157 static char *quotatypes[] = INITQFNAMES;
158 #endif
159 static struct quota_format_type *quota_formats; /* List of registered formats */
160 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
161
162 /* SLAB cache for dquot structures */
163 static struct kmem_cache *dquot_cachep;
164
165 int register_quota_format(struct quota_format_type *fmt)
166 {
167         spin_lock(&dq_list_lock);
168         fmt->qf_next = quota_formats;
169         quota_formats = fmt;
170         spin_unlock(&dq_list_lock);
171         return 0;
172 }
173 EXPORT_SYMBOL(register_quota_format);
174
175 void unregister_quota_format(struct quota_format_type *fmt)
176 {
177         struct quota_format_type **actqf;
178
179         spin_lock(&dq_list_lock);
180         for (actqf = &quota_formats; *actqf && *actqf != fmt;
181              actqf = &(*actqf)->qf_next)
182                 ;
183         if (*actqf)
184                 *actqf = (*actqf)->qf_next;
185         spin_unlock(&dq_list_lock);
186 }
187 EXPORT_SYMBOL(unregister_quota_format);
188
189 static struct quota_format_type *find_quota_format(int id)
190 {
191         struct quota_format_type *actqf;
192
193         spin_lock(&dq_list_lock);
194         for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
195              actqf = actqf->qf_next)
196                 ;
197         if (!actqf || !try_module_get(actqf->qf_owner)) {
198                 int qm;
199
200                 spin_unlock(&dq_list_lock);
201
202                 for (qm = 0; module_names[qm].qm_fmt_id &&
203                              module_names[qm].qm_fmt_id != id; qm++)
204                         ;
205                 if (!module_names[qm].qm_fmt_id ||
206                     request_module(module_names[qm].qm_mod_name))
207                         return NULL;
208
209                 spin_lock(&dq_list_lock);
210                 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
211                      actqf = actqf->qf_next)
212                         ;
213                 if (actqf && !try_module_get(actqf->qf_owner))
214                         actqf = NULL;
215         }
216         spin_unlock(&dq_list_lock);
217         return actqf;
218 }
219
220 static void put_quota_format(struct quota_format_type *fmt)
221 {
222         module_put(fmt->qf_owner);
223 }
224
225 /*
226  * Dquot List Management:
227  * The quota code uses four lists for dquot management: the inuse_list,
228  * free_dquots, dqi_dirty_list, and dquot_hash[] array. A single dquot
229  * structure may be on some of those lists, depending on its current state.
230  *
231  * All dquots are placed to the end of inuse_list when first created, and this
232  * list is used for invalidate operation, which must look at every dquot.
233  *
234  * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
235  * and this list is searched whenever we need an available dquot.  Dquots are
236  * removed from the list as soon as they are used again, and
237  * dqstats.free_dquots gives the number of dquots on the list. When
238  * dquot is invalidated it's completely released from memory.
239  *
240  * Dirty dquots are added to the dqi_dirty_list of quota_info when mark
241  * dirtied, and this list is searched when writing dirty dquots back to
242  * quota file. Note that some filesystems do dirty dquot tracking on their
243  * own (e.g. in a journal) and thus don't use dqi_dirty_list.
244  *
245  * Dquots with a specific identity (device, type and id) are placed on
246  * one of the dquot_hash[] hash chains. The provides an efficient search
247  * mechanism to locate a specific dquot.
248  */
249
250 static LIST_HEAD(inuse_list);
251 static LIST_HEAD(free_dquots);
252 static unsigned int dq_hash_bits, dq_hash_mask;
253 static struct hlist_head *dquot_hash;
254
255 struct dqstats dqstats;
256 EXPORT_SYMBOL(dqstats);
257
258 static qsize_t inode_get_rsv_space(struct inode *inode);
259 static qsize_t __inode_get_rsv_space(struct inode *inode);
260 static int __dquot_initialize(struct inode *inode, int type);
261
262 static inline unsigned int
263 hashfn(const struct super_block *sb, struct kqid qid)
264 {
265         unsigned int id = from_kqid(&init_user_ns, qid);
266         int type = qid.type;
267         unsigned long tmp;
268
269         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
270         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
271 }
272
273 /*
274  * Following list functions expect dq_list_lock to be held
275  */
276 static inline void insert_dquot_hash(struct dquot *dquot)
277 {
278         struct hlist_head *head;
279         head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id);
280         hlist_add_head(&dquot->dq_hash, head);
281 }
282
283 static inline void remove_dquot_hash(struct dquot *dquot)
284 {
285         hlist_del_init(&dquot->dq_hash);
286 }
287
288 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
289                                 struct kqid qid)
290 {
291         struct dquot *dquot;
292
293         hlist_for_each_entry(dquot, dquot_hash+hashent, dq_hash)
294                 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid))
295                         return dquot;
296
297         return NULL;
298 }
299
300 /* Add a dquot to the tail of the free list */
301 static inline void put_dquot_last(struct dquot *dquot)
302 {
303         list_add_tail(&dquot->dq_free, &free_dquots);
304         dqstats_inc(DQST_FREE_DQUOTS);
305 }
306
307 static inline void remove_free_dquot(struct dquot *dquot)
308 {
309         if (list_empty(&dquot->dq_free))
310                 return;
311         list_del_init(&dquot->dq_free);
312         dqstats_dec(DQST_FREE_DQUOTS);
313 }
314
315 static inline void put_inuse(struct dquot *dquot)
316 {
317         /* We add to the back of inuse list so we don't have to restart
318          * when traversing this list and we block */
319         list_add_tail(&dquot->dq_inuse, &inuse_list);
320         dqstats_inc(DQST_ALLOC_DQUOTS);
321 }
322
323 static inline void remove_inuse(struct dquot *dquot)
324 {
325         dqstats_dec(DQST_ALLOC_DQUOTS);
326         list_del(&dquot->dq_inuse);
327 }
328 /*
329  * End of list functions needing dq_list_lock
330  */
331
332 static void wait_on_dquot(struct dquot *dquot)
333 {
334         mutex_lock(&dquot->dq_lock);
335         mutex_unlock(&dquot->dq_lock);
336 }
337
338 static inline int dquot_dirty(struct dquot *dquot)
339 {
340         return test_bit(DQ_MOD_B, &dquot->dq_flags);
341 }
342
343 static inline int mark_dquot_dirty(struct dquot *dquot)
344 {
345         return dquot->dq_sb->dq_op->mark_dirty(dquot);
346 }
347
348 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */
349 int dquot_mark_dquot_dirty(struct dquot *dquot)
350 {
351         int ret = 1;
352
353         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
354                 return 0;
355
356         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
357                 return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags);
358
359         /* If quota is dirty already, we don't have to acquire dq_list_lock */
360         if (test_bit(DQ_MOD_B, &dquot->dq_flags))
361                 return 1;
362
363         spin_lock(&dq_list_lock);
364         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) {
365                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
366                                 info[dquot->dq_id.type].dqi_dirty_list);
367                 ret = 0;
368         }
369         spin_unlock(&dq_list_lock);
370         return ret;
371 }
372 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
373
374 /* Dirtify all the dquots - this can block when journalling */
375 static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
376 {
377         int ret, err, cnt;
378
379         ret = err = 0;
380         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
381                 if (dquot[cnt])
382                         /* Even in case of error we have to continue */
383                         ret = mark_dquot_dirty(dquot[cnt]);
384                 if (!err)
385                         err = ret;
386         }
387         return err;
388 }
389
390 static inline void dqput_all(struct dquot **dquot)
391 {
392         unsigned int cnt;
393
394         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
395                 dqput(dquot[cnt]);
396 }
397
398 static inline int clear_dquot_dirty(struct dquot *dquot)
399 {
400         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
401                 return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags);
402
403         spin_lock(&dq_list_lock);
404         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) {
405                 spin_unlock(&dq_list_lock);
406                 return 0;
407         }
408         list_del_init(&dquot->dq_dirty);
409         spin_unlock(&dq_list_lock);
410         return 1;
411 }
412
413 void mark_info_dirty(struct super_block *sb, int type)
414 {
415         spin_lock(&dq_data_lock);
416         sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY;
417         spin_unlock(&dq_data_lock);
418 }
419 EXPORT_SYMBOL(mark_info_dirty);
420
421 /*
422  *      Read dquot from disk and alloc space for it
423  */
424
425 int dquot_acquire(struct dquot *dquot)
426 {
427         int ret = 0, ret2 = 0;
428         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
429
430         mutex_lock(&dquot->dq_lock);
431         if (!test_bit(DQ_READ_B, &dquot->dq_flags)) {
432                 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
433                 if (ret < 0)
434                         goto out_iolock;
435         }
436         /* Make sure flags update is visible after dquot has been filled */
437         smp_mb__before_atomic();
438         set_bit(DQ_READ_B, &dquot->dq_flags);
439         /* Instantiate dquot if needed */
440         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
441                 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
442                 /* Write the info if needed */
443                 if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
444                         ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
445                                         dquot->dq_sb, dquot->dq_id.type);
446                 }
447                 if (ret < 0)
448                         goto out_iolock;
449                 if (ret2 < 0) {
450                         ret = ret2;
451                         goto out_iolock;
452                 }
453         }
454         /*
455          * Make sure flags update is visible after on-disk struct has been
456          * allocated. Paired with smp_rmb() in dqget().
457          */
458         smp_mb__before_atomic();
459         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
460 out_iolock:
461         mutex_unlock(&dquot->dq_lock);
462         return ret;
463 }
464 EXPORT_SYMBOL(dquot_acquire);
465
466 /*
467  *      Write dquot to disk
468  */
469 int dquot_commit(struct dquot *dquot)
470 {
471         int ret = 0;
472         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
473
474         mutex_lock(&dquot->dq_lock);
475         if (!clear_dquot_dirty(dquot))
476                 goto out_lock;
477         /* Inactive dquot can be only if there was error during read/init
478          * => we have better not writing it */
479         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
480                 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
481         else
482                 ret = -EIO;
483 out_lock:
484         mutex_unlock(&dquot->dq_lock);
485         return ret;
486 }
487 EXPORT_SYMBOL(dquot_commit);
488
489 /*
490  *      Release dquot
491  */
492 int dquot_release(struct dquot *dquot)
493 {
494         int ret = 0, ret2 = 0;
495         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
496
497         mutex_lock(&dquot->dq_lock);
498         /* Check whether we are not racing with some other dqget() */
499         if (dquot_is_busy(dquot))
500                 goto out_dqlock;
501         if (dqopt->ops[dquot->dq_id.type]->release_dqblk) {
502                 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot);
503                 /* Write the info */
504                 if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
505                         ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
506                                                 dquot->dq_sb, dquot->dq_id.type);
507                 }
508                 if (ret >= 0)
509                         ret = ret2;
510         }
511         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
512 out_dqlock:
513         mutex_unlock(&dquot->dq_lock);
514         return ret;
515 }
516 EXPORT_SYMBOL(dquot_release);
517
518 void dquot_destroy(struct dquot *dquot)
519 {
520         kmem_cache_free(dquot_cachep, dquot);
521 }
522 EXPORT_SYMBOL(dquot_destroy);
523
524 static inline void do_destroy_dquot(struct dquot *dquot)
525 {
526         dquot->dq_sb->dq_op->destroy_dquot(dquot);
527 }
528
529 /* Invalidate all dquots on the list. Note that this function is called after
530  * quota is disabled and pointers from inodes removed so there cannot be new
531  * quota users. There can still be some users of quotas due to inodes being
532  * just deleted or pruned by prune_icache() (those are not attached to any
533  * list) or parallel quotactl call. We have to wait for such users.
534  */
535 static void invalidate_dquots(struct super_block *sb, int type)
536 {
537         struct dquot *dquot, *tmp;
538
539 restart:
540         spin_lock(&dq_list_lock);
541         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
542                 if (dquot->dq_sb != sb)
543                         continue;
544                 if (dquot->dq_id.type != type)
545                         continue;
546                 /* Wait for dquot users */
547                 if (atomic_read(&dquot->dq_count)) {
548                         dqgrab(dquot);
549                         spin_unlock(&dq_list_lock);
550                         /*
551                          * Once dqput() wakes us up, we know it's time to free
552                          * the dquot.
553                          * IMPORTANT: we rely on the fact that there is always
554                          * at most one process waiting for dquot to free.
555                          * Otherwise dq_count would be > 1 and we would never
556                          * wake up.
557                          */
558                         wait_event(dquot_ref_wq,
559                                    atomic_read(&dquot->dq_count) == 1);
560                         dqput(dquot);
561                         /* At this moment dquot() need not exist (it could be
562                          * reclaimed by prune_dqcache(). Hence we must
563                          * restart. */
564                         goto restart;
565                 }
566                 /*
567                  * Quota now has no users and it has been written on last
568                  * dqput()
569                  */
570                 remove_dquot_hash(dquot);
571                 remove_free_dquot(dquot);
572                 remove_inuse(dquot);
573                 do_destroy_dquot(dquot);
574         }
575         spin_unlock(&dq_list_lock);
576 }
577
578 /* Call callback for every active dquot on given filesystem */
579 int dquot_scan_active(struct super_block *sb,
580                       int (*fn)(struct dquot *dquot, unsigned long priv),
581                       unsigned long priv)
582 {
583         struct dquot *dquot, *old_dquot = NULL;
584         int ret = 0;
585
586         WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount));
587
588         spin_lock(&dq_list_lock);
589         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
590                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
591                         continue;
592                 if (dquot->dq_sb != sb)
593                         continue;
594                 /* Now we have active dquot so we can just increase use count */
595                 atomic_inc(&dquot->dq_count);
596                 spin_unlock(&dq_list_lock);
597                 dqput(old_dquot);
598                 old_dquot = dquot;
599                 /*
600                  * ->release_dquot() can be racing with us. Our reference
601                  * protects us from new calls to it so just wait for any
602                  * outstanding call and recheck the DQ_ACTIVE_B after that.
603                  */
604                 wait_on_dquot(dquot);
605                 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
606                         ret = fn(dquot, priv);
607                         if (ret < 0)
608                                 goto out;
609                 }
610                 spin_lock(&dq_list_lock);
611                 /* We are safe to continue now because our dquot could not
612                  * be moved out of the inuse list while we hold the reference */
613         }
614         spin_unlock(&dq_list_lock);
615 out:
616         dqput(old_dquot);
617         return ret;
618 }
619 EXPORT_SYMBOL(dquot_scan_active);
620
621 /* Write all dquot structures to quota files */
622 int dquot_writeback_dquots(struct super_block *sb, int type)
623 {
624         struct list_head dirty;
625         struct dquot *dquot;
626         struct quota_info *dqopt = sb_dqopt(sb);
627         int cnt;
628         int err, ret = 0;
629
630         WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount));
631
632         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
633                 if (type != -1 && cnt != type)
634                         continue;
635                 if (!sb_has_quota_active(sb, cnt))
636                         continue;
637                 spin_lock(&dq_list_lock);
638                 /* Move list away to avoid livelock. */
639                 list_replace_init(&dqopt->info[cnt].dqi_dirty_list, &dirty);
640                 while (!list_empty(&dirty)) {
641                         dquot = list_first_entry(&dirty, struct dquot,
642                                                  dq_dirty);
643
644                         WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags));
645
646                         /* Now we have active dquot from which someone is
647                          * holding reference so we can safely just increase
648                          * use count */
649                         dqgrab(dquot);
650                         spin_unlock(&dq_list_lock);
651                         err = sb->dq_op->write_dquot(dquot);
652                         if (err) {
653                                 /*
654                                  * Clear dirty bit anyway to avoid infinite
655                                  * loop here.
656                                  */
657                                 clear_dquot_dirty(dquot);
658                                 if (!ret)
659                                         ret = err;
660                         }
661                         dqput(dquot);
662                         spin_lock(&dq_list_lock);
663                 }
664                 spin_unlock(&dq_list_lock);
665         }
666
667         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
668                 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
669                     && info_dirty(&dqopt->info[cnt]))
670                         sb->dq_op->write_info(sb, cnt);
671         dqstats_inc(DQST_SYNCS);
672
673         return ret;
674 }
675 EXPORT_SYMBOL(dquot_writeback_dquots);
676
677 /* Write all dquot structures to disk and make them visible from userspace */
678 int dquot_quota_sync(struct super_block *sb, int type)
679 {
680         struct quota_info *dqopt = sb_dqopt(sb);
681         int cnt;
682         int ret;
683
684         ret = dquot_writeback_dquots(sb, type);
685         if (ret)
686                 return ret;
687         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
688                 return 0;
689
690         /* This is not very clever (and fast) but currently I don't know about
691          * any other simple way of getting quota data to disk and we must get
692          * them there for userspace to be visible... */
693         if (sb->s_op->sync_fs)
694                 sb->s_op->sync_fs(sb, 1);
695         sync_blockdev(sb->s_bdev);
696
697         /*
698          * Now when everything is written we can discard the pagecache so
699          * that userspace sees the changes.
700          */
701         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
702                 if (type != -1 && cnt != type)
703                         continue;
704                 if (!sb_has_quota_active(sb, cnt))
705                         continue;
706                 inode_lock(dqopt->files[cnt]);
707                 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
708                 inode_unlock(dqopt->files[cnt]);
709         }
710
711         return 0;
712 }
713 EXPORT_SYMBOL(dquot_quota_sync);
714
715 static unsigned long
716 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
717 {
718         struct dquot *dquot;
719         unsigned long freed = 0;
720
721         spin_lock(&dq_list_lock);
722         while (!list_empty(&free_dquots) && sc->nr_to_scan) {
723                 dquot = list_first_entry(&free_dquots, struct dquot, dq_free);
724                 remove_dquot_hash(dquot);
725                 remove_free_dquot(dquot);
726                 remove_inuse(dquot);
727                 do_destroy_dquot(dquot);
728                 sc->nr_to_scan--;
729                 freed++;
730         }
731         spin_unlock(&dq_list_lock);
732         return freed;
733 }
734
735 static unsigned long
736 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
737 {
738         return vfs_pressure_ratio(
739         percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]));
740 }
741
742 static struct shrinker dqcache_shrinker = {
743         .count_objects = dqcache_shrink_count,
744         .scan_objects = dqcache_shrink_scan,
745         .seeks = DEFAULT_SEEKS,
746 };
747
748 /*
749  * Put reference to dquot
750  */
751 void dqput(struct dquot *dquot)
752 {
753         int ret;
754
755         if (!dquot)
756                 return;
757 #ifdef CONFIG_QUOTA_DEBUG
758         if (!atomic_read(&dquot->dq_count)) {
759                 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d",
760                             quotatypes[dquot->dq_id.type],
761                             from_kqid(&init_user_ns, dquot->dq_id));
762                 BUG();
763         }
764 #endif
765         dqstats_inc(DQST_DROPS);
766 we_slept:
767         spin_lock(&dq_list_lock);
768         if (atomic_read(&dquot->dq_count) > 1) {
769                 /* We have more than one user... nothing to do */
770                 atomic_dec(&dquot->dq_count);
771                 /* Releasing dquot during quotaoff phase? */
772                 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) &&
773                     atomic_read(&dquot->dq_count) == 1)
774                         wake_up(&dquot_ref_wq);
775                 spin_unlock(&dq_list_lock);
776                 return;
777         }
778         /* Need to release dquot? */
779         if (dquot_dirty(dquot)) {
780                 spin_unlock(&dq_list_lock);
781                 /* Commit dquot before releasing */
782                 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
783                 if (ret < 0) {
784                         quota_error(dquot->dq_sb, "Can't write quota structure"
785                                     " (error %d). Quota may get out of sync!",
786                                     ret);
787                         /*
788                          * We clear dirty bit anyway, so that we avoid
789                          * infinite loop here
790                          */
791                         clear_dquot_dirty(dquot);
792                 }
793                 goto we_slept;
794         }
795         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
796                 spin_unlock(&dq_list_lock);
797                 dquot->dq_sb->dq_op->release_dquot(dquot);
798                 goto we_slept;
799         }
800         atomic_dec(&dquot->dq_count);
801 #ifdef CONFIG_QUOTA_DEBUG
802         /* sanity check */
803         BUG_ON(!list_empty(&dquot->dq_free));
804 #endif
805         put_dquot_last(dquot);
806         spin_unlock(&dq_list_lock);
807 }
808 EXPORT_SYMBOL(dqput);
809
810 struct dquot *dquot_alloc(struct super_block *sb, int type)
811 {
812         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
813 }
814 EXPORT_SYMBOL(dquot_alloc);
815
816 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
817 {
818         struct dquot *dquot;
819
820         dquot = sb->dq_op->alloc_dquot(sb, type);
821         if(!dquot)
822                 return NULL;
823
824         mutex_init(&dquot->dq_lock);
825         INIT_LIST_HEAD(&dquot->dq_free);
826         INIT_LIST_HEAD(&dquot->dq_inuse);
827         INIT_HLIST_NODE(&dquot->dq_hash);
828         INIT_LIST_HEAD(&dquot->dq_dirty);
829         dquot->dq_sb = sb;
830         dquot->dq_id = make_kqid_invalid(type);
831         atomic_set(&dquot->dq_count, 1);
832         spin_lock_init(&dquot->dq_dqb_lock);
833
834         return dquot;
835 }
836
837 /*
838  * Get reference to dquot
839  *
840  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
841  * destroying our dquot by:
842  *   a) checking for quota flags under dq_list_lock and
843  *   b) getting a reference to dquot before we release dq_list_lock
844  */
845 struct dquot *dqget(struct super_block *sb, struct kqid qid)
846 {
847         unsigned int hashent = hashfn(sb, qid);
848         struct dquot *dquot, *empty = NULL;
849
850         if (!qid_has_mapping(sb->s_user_ns, qid))
851                 return ERR_PTR(-EINVAL);
852
853         if (!sb_has_quota_active(sb, qid.type))
854                 return ERR_PTR(-ESRCH);
855 we_slept:
856         spin_lock(&dq_list_lock);
857         spin_lock(&dq_state_lock);
858         if (!sb_has_quota_active(sb, qid.type)) {
859                 spin_unlock(&dq_state_lock);
860                 spin_unlock(&dq_list_lock);
861                 dquot = ERR_PTR(-ESRCH);
862                 goto out;
863         }
864         spin_unlock(&dq_state_lock);
865
866         dquot = find_dquot(hashent, sb, qid);
867         if (!dquot) {
868                 if (!empty) {
869                         spin_unlock(&dq_list_lock);
870                         empty = get_empty_dquot(sb, qid.type);
871                         if (!empty)
872                                 schedule();     /* Try to wait for a moment... */
873                         goto we_slept;
874                 }
875                 dquot = empty;
876                 empty = NULL;
877                 dquot->dq_id = qid;
878                 /* all dquots go on the inuse_list */
879                 put_inuse(dquot);
880                 /* hash it first so it can be found */
881                 insert_dquot_hash(dquot);
882                 spin_unlock(&dq_list_lock);
883                 dqstats_inc(DQST_LOOKUPS);
884         } else {
885                 if (!atomic_read(&dquot->dq_count))
886                         remove_free_dquot(dquot);
887                 atomic_inc(&dquot->dq_count);
888                 spin_unlock(&dq_list_lock);
889                 dqstats_inc(DQST_CACHE_HITS);
890                 dqstats_inc(DQST_LOOKUPS);
891         }
892         /* Wait for dq_lock - after this we know that either dquot_release() is
893          * already finished or it will be canceled due to dq_count > 1 test */
894         wait_on_dquot(dquot);
895         /* Read the dquot / allocate space in quota file */
896         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
897                 int err;
898
899                 err = sb->dq_op->acquire_dquot(dquot);
900                 if (err < 0) {
901                         dqput(dquot);
902                         dquot = ERR_PTR(err);
903                         goto out;
904                 }
905         }
906         /*
907          * Make sure following reads see filled structure - paired with
908          * smp_mb__before_atomic() in dquot_acquire().
909          */
910         smp_rmb();
911 #ifdef CONFIG_QUOTA_DEBUG
912         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
913 #endif
914 out:
915         if (empty)
916                 do_destroy_dquot(empty);
917
918         return dquot;
919 }
920 EXPORT_SYMBOL(dqget);
921
922 static inline struct dquot **i_dquot(struct inode *inode)
923 {
924         return inode->i_sb->s_op->get_dquots(inode);
925 }
926
927 static int dqinit_needed(struct inode *inode, int type)
928 {
929         struct dquot * const *dquots;
930         int cnt;
931
932         if (IS_NOQUOTA(inode))
933                 return 0;
934
935         dquots = i_dquot(inode);
936         if (type != -1)
937                 return !dquots[type];
938         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
939                 if (!dquots[cnt])
940                         return 1;
941         return 0;
942 }
943
944 /* This routine is guarded by s_umount semaphore */
945 static int add_dquot_ref(struct super_block *sb, int type)
946 {
947         struct inode *inode, *old_inode = NULL;
948 #ifdef CONFIG_QUOTA_DEBUG
949         int reserved = 0;
950 #endif
951         int err = 0;
952
953         spin_lock(&sb->s_inode_list_lock);
954         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
955                 spin_lock(&inode->i_lock);
956                 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
957                     !atomic_read(&inode->i_writecount) ||
958                     !dqinit_needed(inode, type)) {
959                         spin_unlock(&inode->i_lock);
960                         continue;
961                 }
962                 __iget(inode);
963                 spin_unlock(&inode->i_lock);
964                 spin_unlock(&sb->s_inode_list_lock);
965
966 #ifdef CONFIG_QUOTA_DEBUG
967                 if (unlikely(inode_get_rsv_space(inode) > 0))
968                         reserved = 1;
969 #endif
970                 iput(old_inode);
971                 err = __dquot_initialize(inode, type);
972                 if (err) {
973                         iput(inode);
974                         goto out;
975                 }
976
977                 /*
978                  * We hold a reference to 'inode' so it couldn't have been
979                  * removed from s_inodes list while we dropped the
980                  * s_inode_list_lock. We cannot iput the inode now as we can be
981                  * holding the last reference and we cannot iput it under
982                  * s_inode_list_lock. So we keep the reference and iput it
983                  * later.
984                  */
985                 old_inode = inode;
986                 cond_resched();
987                 spin_lock(&sb->s_inode_list_lock);
988         }
989         spin_unlock(&sb->s_inode_list_lock);
990         iput(old_inode);
991 out:
992 #ifdef CONFIG_QUOTA_DEBUG
993         if (reserved) {
994                 quota_error(sb, "Writes happened before quota was turned on "
995                         "thus quota information is probably inconsistent. "
996                         "Please run quotacheck(8)");
997         }
998 #endif
999         return err;
1000 }
1001
1002 /*
1003  * Remove references to dquots from inode and add dquot to list for freeing
1004  * if we have the last reference to dquot
1005  */
1006 static void remove_inode_dquot_ref(struct inode *inode, int type,
1007                                    struct list_head *tofree_head)
1008 {
1009         struct dquot **dquots = i_dquot(inode);
1010         struct dquot *dquot = dquots[type];
1011
1012         if (!dquot)
1013                 return;
1014
1015         dquots[type] = NULL;
1016         if (list_empty(&dquot->dq_free)) {
1017                 /*
1018                  * The inode still has reference to dquot so it can't be in the
1019                  * free list
1020                  */
1021                 spin_lock(&dq_list_lock);
1022                 list_add(&dquot->dq_free, tofree_head);
1023                 spin_unlock(&dq_list_lock);
1024         } else {
1025                 /*
1026                  * Dquot is already in a list to put so we won't drop the last
1027                  * reference here.
1028                  */
1029                 dqput(dquot);
1030         }
1031 }
1032
1033 /*
1034  * Free list of dquots
1035  * Dquots are removed from inodes and no new references can be got so we are
1036  * the only ones holding reference
1037  */
1038 static void put_dquot_list(struct list_head *tofree_head)
1039 {
1040         struct list_head *act_head;
1041         struct dquot *dquot;
1042
1043         act_head = tofree_head->next;
1044         while (act_head != tofree_head) {
1045                 dquot = list_entry(act_head, struct dquot, dq_free);
1046                 act_head = act_head->next;
1047                 /* Remove dquot from the list so we won't have problems... */
1048                 list_del_init(&dquot->dq_free);
1049                 dqput(dquot);
1050         }
1051 }
1052
1053 static void remove_dquot_ref(struct super_block *sb, int type,
1054                 struct list_head *tofree_head)
1055 {
1056         struct inode *inode;
1057 #ifdef CONFIG_QUOTA_DEBUG
1058         int reserved = 0;
1059 #endif
1060
1061         spin_lock(&sb->s_inode_list_lock);
1062         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
1063                 /*
1064                  *  We have to scan also I_NEW inodes because they can already
1065                  *  have quota pointer initialized. Luckily, we need to touch
1066                  *  only quota pointers and these have separate locking
1067                  *  (dq_data_lock).
1068                  */
1069                 spin_lock(&dq_data_lock);
1070                 if (!IS_NOQUOTA(inode)) {
1071 #ifdef CONFIG_QUOTA_DEBUG
1072                         if (unlikely(inode_get_rsv_space(inode) > 0))
1073                                 reserved = 1;
1074 #endif
1075                         remove_inode_dquot_ref(inode, type, tofree_head);
1076                 }
1077                 spin_unlock(&dq_data_lock);
1078         }
1079         spin_unlock(&sb->s_inode_list_lock);
1080 #ifdef CONFIG_QUOTA_DEBUG
1081         if (reserved) {
1082                 printk(KERN_WARNING "VFS (%s): Writes happened after quota"
1083                         " was disabled thus quota information is probably "
1084                         "inconsistent. Please run quotacheck(8).\n", sb->s_id);
1085         }
1086 #endif
1087 }
1088
1089 /* Gather all references from inodes and drop them */
1090 static void drop_dquot_ref(struct super_block *sb, int type)
1091 {
1092         LIST_HEAD(tofree_head);
1093
1094         if (sb->dq_op) {
1095                 remove_dquot_ref(sb, type, &tofree_head);
1096                 synchronize_srcu(&dquot_srcu);
1097                 put_dquot_list(&tofree_head);
1098         }
1099 }
1100
1101 static inline
1102 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
1103 {
1104         if (dquot->dq_dqb.dqb_rsvspace >= number)
1105                 dquot->dq_dqb.dqb_rsvspace -= number;
1106         else {
1107                 WARN_ON_ONCE(1);
1108                 dquot->dq_dqb.dqb_rsvspace = 0;
1109         }
1110         if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <=
1111             dquot->dq_dqb.dqb_bsoftlimit)
1112                 dquot->dq_dqb.dqb_btime = (time64_t) 0;
1113         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1114 }
1115
1116 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1117 {
1118         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1119             dquot->dq_dqb.dqb_curinodes >= number)
1120                 dquot->dq_dqb.dqb_curinodes -= number;
1121         else
1122                 dquot->dq_dqb.dqb_curinodes = 0;
1123         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1124                 dquot->dq_dqb.dqb_itime = (time64_t) 0;
1125         clear_bit(DQ_INODES_B, &dquot->dq_flags);
1126 }
1127
1128 static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1129 {
1130         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1131             dquot->dq_dqb.dqb_curspace >= number)
1132                 dquot->dq_dqb.dqb_curspace -= number;
1133         else
1134                 dquot->dq_dqb.dqb_curspace = 0;
1135         if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <=
1136             dquot->dq_dqb.dqb_bsoftlimit)
1137                 dquot->dq_dqb.dqb_btime = (time64_t) 0;
1138         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1139 }
1140
1141 struct dquot_warn {
1142         struct super_block *w_sb;
1143         struct kqid w_dq_id;
1144         short w_type;
1145 };
1146
1147 static int warning_issued(struct dquot *dquot, const int warntype)
1148 {
1149         int flag = (warntype == QUOTA_NL_BHARDWARN ||
1150                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1151                 ((warntype == QUOTA_NL_IHARDWARN ||
1152                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1153
1154         if (!flag)
1155                 return 0;
1156         return test_and_set_bit(flag, &dquot->dq_flags);
1157 }
1158
1159 #ifdef CONFIG_PRINT_QUOTA_WARNING
1160 static int flag_print_warnings = 1;
1161
1162 static int need_print_warning(struct dquot_warn *warn)
1163 {
1164         if (!flag_print_warnings)
1165                 return 0;
1166
1167         switch (warn->w_dq_id.type) {
1168                 case USRQUOTA:
1169                         return uid_eq(current_fsuid(), warn->w_dq_id.uid);
1170                 case GRPQUOTA:
1171                         return in_group_p(warn->w_dq_id.gid);
1172                 case PRJQUOTA:
1173                         return 1;
1174         }
1175         return 0;
1176 }
1177
1178 /* Print warning to user which exceeded quota */
1179 static void print_warning(struct dquot_warn *warn)
1180 {
1181         char *msg = NULL;
1182         struct tty_struct *tty;
1183         int warntype = warn->w_type;
1184
1185         if (warntype == QUOTA_NL_IHARDBELOW ||
1186             warntype == QUOTA_NL_ISOFTBELOW ||
1187             warntype == QUOTA_NL_BHARDBELOW ||
1188             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn))
1189                 return;
1190
1191         tty = get_current_tty();
1192         if (!tty)
1193                 return;
1194         tty_write_message(tty, warn->w_sb->s_id);
1195         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1196                 tty_write_message(tty, ": warning, ");
1197         else
1198                 tty_write_message(tty, ": write failed, ");
1199         tty_write_message(tty, quotatypes[warn->w_dq_id.type]);
1200         switch (warntype) {
1201                 case QUOTA_NL_IHARDWARN:
1202                         msg = " file limit reached.\r\n";
1203                         break;
1204                 case QUOTA_NL_ISOFTLONGWARN:
1205                         msg = " file quota exceeded too long.\r\n";
1206                         break;
1207                 case QUOTA_NL_ISOFTWARN:
1208                         msg = " file quota exceeded.\r\n";
1209                         break;
1210                 case QUOTA_NL_BHARDWARN:
1211                         msg = " block limit reached.\r\n";
1212                         break;
1213                 case QUOTA_NL_BSOFTLONGWARN:
1214                         msg = " block quota exceeded too long.\r\n";
1215                         break;
1216                 case QUOTA_NL_BSOFTWARN:
1217                         msg = " block quota exceeded.\r\n";
1218                         break;
1219         }
1220         tty_write_message(tty, msg);
1221         tty_kref_put(tty);
1222 }
1223 #endif
1224
1225 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot,
1226                             int warntype)
1227 {
1228         if (warning_issued(dquot, warntype))
1229                 return;
1230         warn->w_type = warntype;
1231         warn->w_sb = dquot->dq_sb;
1232         warn->w_dq_id = dquot->dq_id;
1233 }
1234
1235 /*
1236  * Write warnings to the console and send warning messages over netlink.
1237  *
1238  * Note that this function can call into tty and networking code.
1239  */
1240 static void flush_warnings(struct dquot_warn *warn)
1241 {
1242         int i;
1243
1244         for (i = 0; i < MAXQUOTAS; i++) {
1245                 if (warn[i].w_type == QUOTA_NL_NOWARN)
1246                         continue;
1247 #ifdef CONFIG_PRINT_QUOTA_WARNING
1248                 print_warning(&warn[i]);
1249 #endif
1250                 quota_send_warning(warn[i].w_dq_id,
1251                                    warn[i].w_sb->s_dev, warn[i].w_type);
1252         }
1253 }
1254
1255 static int ignore_hardlimit(struct dquot *dquot)
1256 {
1257         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
1258
1259         return capable(CAP_SYS_RESOURCE) &&
1260                (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1261                 !(info->dqi_flags & DQF_ROOT_SQUASH));
1262 }
1263
1264 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes,
1265                             struct dquot_warn *warn)
1266 {
1267         qsize_t newinodes;
1268         int ret = 0;
1269
1270         spin_lock(&dquot->dq_dqb_lock);
1271         newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1272         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) ||
1273             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1274                 goto add;
1275
1276         if (dquot->dq_dqb.dqb_ihardlimit &&
1277             newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1278             !ignore_hardlimit(dquot)) {
1279                 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN);
1280                 ret = -EDQUOT;
1281                 goto out;
1282         }
1283
1284         if (dquot->dq_dqb.dqb_isoftlimit &&
1285             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1286             dquot->dq_dqb.dqb_itime &&
1287             ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime &&
1288             !ignore_hardlimit(dquot)) {
1289                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN);
1290                 ret = -EDQUOT;
1291                 goto out;
1292         }
1293
1294         if (dquot->dq_dqb.dqb_isoftlimit &&
1295             newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1296             dquot->dq_dqb.dqb_itime == 0) {
1297                 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN);
1298                 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() +
1299                     sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace;
1300         }
1301 add:
1302         dquot->dq_dqb.dqb_curinodes = newinodes;
1303
1304 out:
1305         spin_unlock(&dquot->dq_dqb_lock);
1306         return ret;
1307 }
1308
1309 static int dquot_add_space(struct dquot *dquot, qsize_t space,
1310                            qsize_t rsv_space, unsigned int flags,
1311                            struct dquot_warn *warn)
1312 {
1313         qsize_t tspace;
1314         struct super_block *sb = dquot->dq_sb;
1315         int ret = 0;
1316
1317         spin_lock(&dquot->dq_dqb_lock);
1318         if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) ||
1319             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1320                 goto finish;
1321
1322         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1323                 + space + rsv_space;
1324
1325         if (dquot->dq_dqb.dqb_bhardlimit &&
1326             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1327             !ignore_hardlimit(dquot)) {
1328                 if (flags & DQUOT_SPACE_WARN)
1329                         prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN);
1330                 ret = -EDQUOT;
1331                 goto finish;
1332         }
1333
1334         if (dquot->dq_dqb.dqb_bsoftlimit &&
1335             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1336             dquot->dq_dqb.dqb_btime &&
1337             ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime &&
1338             !ignore_hardlimit(dquot)) {
1339                 if (flags & DQUOT_SPACE_WARN)
1340                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN);
1341                 ret = -EDQUOT;
1342                 goto finish;
1343         }
1344
1345         if (dquot->dq_dqb.dqb_bsoftlimit &&
1346             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1347             dquot->dq_dqb.dqb_btime == 0) {
1348                 if (flags & DQUOT_SPACE_WARN) {
1349                         prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN);
1350                         dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() +
1351                             sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace;
1352                 } else {
1353                         /*
1354                          * We don't allow preallocation to exceed softlimit so exceeding will
1355                          * be always printed
1356                          */
1357                         ret = -EDQUOT;
1358                         goto finish;
1359                 }
1360         }
1361 finish:
1362         /*
1363          * We have to be careful and go through warning generation & grace time
1364          * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it
1365          * only here...
1366          */
1367         if (flags & DQUOT_SPACE_NOFAIL)
1368                 ret = 0;
1369         if (!ret) {
1370                 dquot->dq_dqb.dqb_rsvspace += rsv_space;
1371                 dquot->dq_dqb.dqb_curspace += space;
1372         }
1373         spin_unlock(&dquot->dq_dqb_lock);
1374         return ret;
1375 }
1376
1377 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1378 {
1379         qsize_t newinodes;
1380
1381         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1382             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1383             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type))
1384                 return QUOTA_NL_NOWARN;
1385
1386         newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1387         if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
1388                 return QUOTA_NL_ISOFTBELOW;
1389         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1390             newinodes < dquot->dq_dqb.dqb_ihardlimit)
1391                 return QUOTA_NL_IHARDBELOW;
1392         return QUOTA_NL_NOWARN;
1393 }
1394
1395 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1396 {
1397         qsize_t tspace;
1398
1399         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace;
1400
1401         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1402             tspace <= dquot->dq_dqb.dqb_bsoftlimit)
1403                 return QUOTA_NL_NOWARN;
1404
1405         if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1406                 return QUOTA_NL_BSOFTBELOW;
1407         if (tspace >= dquot->dq_dqb.dqb_bhardlimit &&
1408             tspace - space < dquot->dq_dqb.dqb_bhardlimit)
1409                 return QUOTA_NL_BHARDBELOW;
1410         return QUOTA_NL_NOWARN;
1411 }
1412
1413 static int dquot_active(const struct inode *inode)
1414 {
1415         struct super_block *sb = inode->i_sb;
1416
1417         if (IS_NOQUOTA(inode))
1418                 return 0;
1419         return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
1420 }
1421
1422 /*
1423  * Initialize quota pointers in inode
1424  *
1425  * It is better to call this function outside of any transaction as it
1426  * might need a lot of space in journal for dquot structure allocation.
1427  */
1428 static int __dquot_initialize(struct inode *inode, int type)
1429 {
1430         int cnt, init_needed = 0;
1431         struct dquot **dquots, *got[MAXQUOTAS] = {};
1432         struct super_block *sb = inode->i_sb;
1433         qsize_t rsv;
1434         int ret = 0;
1435
1436         if (!dquot_active(inode))
1437                 return 0;
1438
1439         dquots = i_dquot(inode);
1440
1441         /* First get references to structures we might need. */
1442         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1443                 struct kqid qid;
1444                 kprojid_t projid;
1445                 int rc;
1446                 struct dquot *dquot;
1447
1448                 if (type != -1 && cnt != type)
1449                         continue;
1450                 /*
1451                  * The i_dquot should have been initialized in most cases,
1452                  * we check it without locking here to avoid unnecessary
1453                  * dqget()/dqput() calls.
1454                  */
1455                 if (dquots[cnt])
1456                         continue;
1457
1458                 if (!sb_has_quota_active(sb, cnt))
1459                         continue;
1460
1461                 init_needed = 1;
1462
1463                 switch (cnt) {
1464                 case USRQUOTA:
1465                         qid = make_kqid_uid(inode->i_uid);
1466                         break;
1467                 case GRPQUOTA:
1468                         qid = make_kqid_gid(inode->i_gid);
1469                         break;
1470                 case PRJQUOTA:
1471                         rc = inode->i_sb->dq_op->get_projid(inode, &projid);
1472                         if (rc)
1473                                 continue;
1474                         qid = make_kqid_projid(projid);
1475                         break;
1476                 }
1477                 dquot = dqget(sb, qid);
1478                 if (IS_ERR(dquot)) {
1479                         /* We raced with somebody turning quotas off... */
1480                         if (PTR_ERR(dquot) != -ESRCH) {
1481                                 ret = PTR_ERR(dquot);
1482                                 goto out_put;
1483                         }
1484                         dquot = NULL;
1485                 }
1486                 got[cnt] = dquot;
1487         }
1488
1489         /* All required i_dquot has been initialized */
1490         if (!init_needed)
1491                 return 0;
1492
1493         spin_lock(&dq_data_lock);
1494         if (IS_NOQUOTA(inode))
1495                 goto out_lock;
1496         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1497                 if (type != -1 && cnt != type)
1498                         continue;
1499                 /* Avoid races with quotaoff() */
1500                 if (!sb_has_quota_active(sb, cnt))
1501                         continue;
1502                 /* We could race with quotaon or dqget() could have failed */
1503                 if (!got[cnt])
1504                         continue;
1505                 if (!dquots[cnt]) {
1506                         dquots[cnt] = got[cnt];
1507                         got[cnt] = NULL;
1508                         /*
1509                          * Make quota reservation system happy if someone
1510                          * did a write before quota was turned on
1511                          */
1512                         rsv = inode_get_rsv_space(inode);
1513                         if (unlikely(rsv)) {
1514                                 spin_lock(&inode->i_lock);
1515                                 /* Get reservation again under proper lock */
1516                                 rsv = __inode_get_rsv_space(inode);
1517                                 spin_lock(&dquots[cnt]->dq_dqb_lock);
1518                                 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv;
1519                                 spin_unlock(&dquots[cnt]->dq_dqb_lock);
1520                                 spin_unlock(&inode->i_lock);
1521                         }
1522                 }
1523         }
1524 out_lock:
1525         spin_unlock(&dq_data_lock);
1526 out_put:
1527         /* Drop unused references */
1528         dqput_all(got);
1529
1530         return ret;
1531 }
1532
1533 int dquot_initialize(struct inode *inode)
1534 {
1535         return __dquot_initialize(inode, -1);
1536 }
1537 EXPORT_SYMBOL(dquot_initialize);
1538
1539 bool dquot_initialize_needed(struct inode *inode)
1540 {
1541         struct dquot **dquots;
1542         int i;
1543
1544         if (!dquot_active(inode))
1545                 return false;
1546
1547         dquots = i_dquot(inode);
1548         for (i = 0; i < MAXQUOTAS; i++)
1549                 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i))
1550                         return true;
1551         return false;
1552 }
1553 EXPORT_SYMBOL(dquot_initialize_needed);
1554
1555 /*
1556  * Release all quotas referenced by inode.
1557  *
1558  * This function only be called on inode free or converting
1559  * a file to quota file, no other users for the i_dquot in
1560  * both cases, so we needn't call synchronize_srcu() after
1561  * clearing i_dquot.
1562  */
1563 static void __dquot_drop(struct inode *inode)
1564 {
1565         int cnt;
1566         struct dquot **dquots = i_dquot(inode);
1567         struct dquot *put[MAXQUOTAS];
1568
1569         spin_lock(&dq_data_lock);
1570         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1571                 put[cnt] = dquots[cnt];
1572                 dquots[cnt] = NULL;
1573         }
1574         spin_unlock(&dq_data_lock);
1575         dqput_all(put);
1576 }
1577
1578 void dquot_drop(struct inode *inode)
1579 {
1580         struct dquot * const *dquots;
1581         int cnt;
1582
1583         if (IS_NOQUOTA(inode))
1584                 return;
1585
1586         /*
1587          * Test before calling to rule out calls from proc and such
1588          * where we are not allowed to block. Note that this is
1589          * actually reliable test even without the lock - the caller
1590          * must assure that nobody can come after the DQUOT_DROP and
1591          * add quota pointers back anyway.
1592          */
1593         dquots = i_dquot(inode);
1594         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1595                 if (dquots[cnt])
1596                         break;
1597         }
1598
1599         if (cnt < MAXQUOTAS)
1600                 __dquot_drop(inode);
1601 }
1602 EXPORT_SYMBOL(dquot_drop);
1603
1604 /*
1605  * inode_reserved_space is managed internally by quota, and protected by
1606  * i_lock similar to i_blocks+i_bytes.
1607  */
1608 static qsize_t *inode_reserved_space(struct inode * inode)
1609 {
1610         /* Filesystem must explicitly define it's own method in order to use
1611          * quota reservation interface */
1612         BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1613         return inode->i_sb->dq_op->get_reserved_space(inode);
1614 }
1615
1616 static qsize_t __inode_get_rsv_space(struct inode *inode)
1617 {
1618         if (!inode->i_sb->dq_op->get_reserved_space)
1619                 return 0;
1620         return *inode_reserved_space(inode);
1621 }
1622
1623 static qsize_t inode_get_rsv_space(struct inode *inode)
1624 {
1625         qsize_t ret;
1626
1627         if (!inode->i_sb->dq_op->get_reserved_space)
1628                 return 0;
1629         spin_lock(&inode->i_lock);
1630         ret = __inode_get_rsv_space(inode);
1631         spin_unlock(&inode->i_lock);
1632         return ret;
1633 }
1634
1635 /*
1636  * This functions updates i_blocks+i_bytes fields and quota information
1637  * (together with appropriate checks).
1638  *
1639  * NOTE: We absolutely rely on the fact that caller dirties the inode
1640  * (usually helpers in quotaops.h care about this) and holds a handle for
1641  * the current transaction so that dquot write and inode write go into the
1642  * same transaction.
1643  */
1644
1645 /*
1646  * This operation can block, but only after everything is updated
1647  */
1648 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
1649 {
1650         int cnt, ret = 0, index;
1651         struct dquot_warn warn[MAXQUOTAS];
1652         int reserve = flags & DQUOT_SPACE_RESERVE;
1653         struct dquot **dquots;
1654
1655         if (!dquot_active(inode)) {
1656                 if (reserve) {
1657                         spin_lock(&inode->i_lock);
1658                         *inode_reserved_space(inode) += number;
1659                         spin_unlock(&inode->i_lock);
1660                 } else {
1661                         inode_add_bytes(inode, number);
1662                 }
1663                 goto out;
1664         }
1665
1666         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1667                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1668
1669         dquots = i_dquot(inode);
1670         index = srcu_read_lock(&dquot_srcu);
1671         spin_lock(&inode->i_lock);
1672         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1673                 if (!dquots[cnt])
1674                         continue;
1675                 if (reserve) {
1676                         ret = dquot_add_space(dquots[cnt], 0, number, flags,
1677                                               &warn[cnt]);
1678                 } else {
1679                         ret = dquot_add_space(dquots[cnt], number, 0, flags,
1680                                               &warn[cnt]);
1681                 }
1682                 if (ret) {
1683                         /* Back out changes we already did */
1684                         for (cnt--; cnt >= 0; cnt--) {
1685                                 if (!dquots[cnt])
1686                                         continue;
1687                                 spin_lock(&dquots[cnt]->dq_dqb_lock);
1688                                 if (reserve)
1689                                         dquot_free_reserved_space(dquots[cnt],
1690                                                                   number);
1691                                 else
1692                                         dquot_decr_space(dquots[cnt], number);
1693                                 spin_unlock(&dquots[cnt]->dq_dqb_lock);
1694                         }
1695                         spin_unlock(&inode->i_lock);
1696                         goto out_flush_warn;
1697                 }
1698         }
1699         if (reserve)
1700                 *inode_reserved_space(inode) += number;
1701         else
1702                 __inode_add_bytes(inode, number);
1703         spin_unlock(&inode->i_lock);
1704
1705         if (reserve)
1706                 goto out_flush_warn;
1707         mark_all_dquot_dirty(dquots);
1708 out_flush_warn:
1709         srcu_read_unlock(&dquot_srcu, index);
1710         flush_warnings(warn);
1711 out:
1712         return ret;
1713 }
1714 EXPORT_SYMBOL(__dquot_alloc_space);
1715
1716 /*
1717  * This operation can block, but only after everything is updated
1718  */
1719 int dquot_alloc_inode(struct inode *inode)
1720 {
1721         int cnt, ret = 0, index;
1722         struct dquot_warn warn[MAXQUOTAS];
1723         struct dquot * const *dquots;
1724
1725         if (!dquot_active(inode))
1726                 return 0;
1727         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1728                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1729
1730         dquots = i_dquot(inode);
1731         index = srcu_read_lock(&dquot_srcu);
1732         spin_lock(&inode->i_lock);
1733         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1734                 if (!dquots[cnt])
1735                         continue;
1736                 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]);
1737                 if (ret) {
1738                         for (cnt--; cnt >= 0; cnt--) {
1739                                 if (!dquots[cnt])
1740                                         continue;
1741                                 /* Back out changes we already did */
1742                                 spin_lock(&dquots[cnt]->dq_dqb_lock);
1743                                 dquot_decr_inodes(dquots[cnt], 1);
1744                                 spin_unlock(&dquots[cnt]->dq_dqb_lock);
1745                         }
1746                         goto warn_put_all;
1747                 }
1748         }
1749
1750 warn_put_all:
1751         spin_unlock(&inode->i_lock);
1752         if (ret == 0)
1753                 mark_all_dquot_dirty(dquots);
1754         srcu_read_unlock(&dquot_srcu, index);
1755         flush_warnings(warn);
1756         return ret;
1757 }
1758 EXPORT_SYMBOL(dquot_alloc_inode);
1759
1760 /*
1761  * Convert in-memory reserved quotas to real consumed quotas
1762  */
1763 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
1764 {
1765         struct dquot **dquots;
1766         int cnt, index;
1767
1768         if (!dquot_active(inode)) {
1769                 spin_lock(&inode->i_lock);
1770                 *inode_reserved_space(inode) -= number;
1771                 __inode_add_bytes(inode, number);
1772                 spin_unlock(&inode->i_lock);
1773                 return 0;
1774         }
1775
1776         dquots = i_dquot(inode);
1777         index = srcu_read_lock(&dquot_srcu);
1778         spin_lock(&inode->i_lock);
1779         /* Claim reserved quotas to allocated quotas */
1780         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1781                 if (dquots[cnt]) {
1782                         struct dquot *dquot = dquots[cnt];
1783
1784                         spin_lock(&dquot->dq_dqb_lock);
1785                         if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number))
1786                                 number = dquot->dq_dqb.dqb_rsvspace;
1787                         dquot->dq_dqb.dqb_curspace += number;
1788                         dquot->dq_dqb.dqb_rsvspace -= number;
1789                         spin_unlock(&dquot->dq_dqb_lock);
1790                 }
1791         }
1792         /* Update inode bytes */
1793         *inode_reserved_space(inode) -= number;
1794         __inode_add_bytes(inode, number);
1795         spin_unlock(&inode->i_lock);
1796         mark_all_dquot_dirty(dquots);
1797         srcu_read_unlock(&dquot_srcu, index);
1798         return 0;
1799 }
1800 EXPORT_SYMBOL(dquot_claim_space_nodirty);
1801
1802 /*
1803  * Convert allocated space back to in-memory reserved quotas
1804  */
1805 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number)
1806 {
1807         struct dquot **dquots;
1808         int cnt, index;
1809
1810         if (!dquot_active(inode)) {
1811                 spin_lock(&inode->i_lock);
1812                 *inode_reserved_space(inode) += number;
1813                 __inode_sub_bytes(inode, number);
1814                 spin_unlock(&inode->i_lock);
1815                 return;
1816         }
1817
1818         dquots = i_dquot(inode);
1819         index = srcu_read_lock(&dquot_srcu);
1820         spin_lock(&inode->i_lock);
1821         /* Claim reserved quotas to allocated quotas */
1822         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1823                 if (dquots[cnt]) {
1824                         struct dquot *dquot = dquots[cnt];
1825
1826                         spin_lock(&dquot->dq_dqb_lock);
1827                         if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number))
1828                                 number = dquot->dq_dqb.dqb_curspace;
1829                         dquot->dq_dqb.dqb_rsvspace += number;
1830                         dquot->dq_dqb.dqb_curspace -= number;
1831                         spin_unlock(&dquot->dq_dqb_lock);
1832                 }
1833         }
1834         /* Update inode bytes */
1835         *inode_reserved_space(inode) += number;
1836         __inode_sub_bytes(inode, number);
1837         spin_unlock(&inode->i_lock);
1838         mark_all_dquot_dirty(dquots);
1839         srcu_read_unlock(&dquot_srcu, index);
1840         return;
1841 }
1842 EXPORT_SYMBOL(dquot_reclaim_space_nodirty);
1843
1844 /*
1845  * This operation can block, but only after everything is updated
1846  */
1847 void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
1848 {
1849         unsigned int cnt;
1850         struct dquot_warn warn[MAXQUOTAS];
1851         struct dquot **dquots;
1852         int reserve = flags & DQUOT_SPACE_RESERVE, index;
1853
1854         if (!dquot_active(inode)) {
1855                 if (reserve) {
1856                         spin_lock(&inode->i_lock);
1857                         *inode_reserved_space(inode) -= number;
1858                         spin_unlock(&inode->i_lock);
1859                 } else {
1860                         inode_sub_bytes(inode, number);
1861                 }
1862                 return;
1863         }
1864
1865         dquots = i_dquot(inode);
1866         index = srcu_read_lock(&dquot_srcu);
1867         spin_lock(&inode->i_lock);
1868         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1869                 int wtype;
1870
1871                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1872                 if (!dquots[cnt])
1873                         continue;
1874                 spin_lock(&dquots[cnt]->dq_dqb_lock);
1875                 wtype = info_bdq_free(dquots[cnt], number);
1876                 if (wtype != QUOTA_NL_NOWARN)
1877                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1878                 if (reserve)
1879                         dquot_free_reserved_space(dquots[cnt], number);
1880                 else
1881                         dquot_decr_space(dquots[cnt], number);
1882                 spin_unlock(&dquots[cnt]->dq_dqb_lock);
1883         }
1884         if (reserve)
1885                 *inode_reserved_space(inode) -= number;
1886         else
1887                 __inode_sub_bytes(inode, number);
1888         spin_unlock(&inode->i_lock);
1889
1890         if (reserve)
1891                 goto out_unlock;
1892         mark_all_dquot_dirty(dquots);
1893 out_unlock:
1894         srcu_read_unlock(&dquot_srcu, index);
1895         flush_warnings(warn);
1896 }
1897 EXPORT_SYMBOL(__dquot_free_space);
1898
1899 /*
1900  * This operation can block, but only after everything is updated
1901  */
1902 void dquot_free_inode(struct inode *inode)
1903 {
1904         unsigned int cnt;
1905         struct dquot_warn warn[MAXQUOTAS];
1906         struct dquot * const *dquots;
1907         int index;
1908
1909         if (!dquot_active(inode))
1910                 return;
1911
1912         dquots = i_dquot(inode);
1913         index = srcu_read_lock(&dquot_srcu);
1914         spin_lock(&inode->i_lock);
1915         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1916                 int wtype;
1917
1918                 warn[cnt].w_type = QUOTA_NL_NOWARN;
1919                 if (!dquots[cnt])
1920                         continue;
1921                 spin_lock(&dquots[cnt]->dq_dqb_lock);
1922                 wtype = info_idq_free(dquots[cnt], 1);
1923                 if (wtype != QUOTA_NL_NOWARN)
1924                         prepare_warning(&warn[cnt], dquots[cnt], wtype);
1925                 dquot_decr_inodes(dquots[cnt], 1);
1926                 spin_unlock(&dquots[cnt]->dq_dqb_lock);
1927         }
1928         spin_unlock(&inode->i_lock);
1929         mark_all_dquot_dirty(dquots);
1930         srcu_read_unlock(&dquot_srcu, index);
1931         flush_warnings(warn);
1932 }
1933 EXPORT_SYMBOL(dquot_free_inode);
1934
1935 /*
1936  * Transfer the number of inode and blocks from one diskquota to an other.
1937  * On success, dquot references in transfer_to are consumed and references
1938  * to original dquots that need to be released are placed there. On failure,
1939  * references are kept untouched.
1940  *
1941  * This operation can block, but only after everything is updated
1942  * A transaction must be started when entering this function.
1943  *
1944  * We are holding reference on transfer_from & transfer_to, no need to
1945  * protect them by srcu_read_lock().
1946  */
1947 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
1948 {
1949         qsize_t cur_space;
1950         qsize_t rsv_space = 0;
1951         qsize_t inode_usage = 1;
1952         struct dquot *transfer_from[MAXQUOTAS] = {};
1953         int cnt, ret = 0;
1954         char is_valid[MAXQUOTAS] = {};
1955         struct dquot_warn warn_to[MAXQUOTAS];
1956         struct dquot_warn warn_from_inodes[MAXQUOTAS];
1957         struct dquot_warn warn_from_space[MAXQUOTAS];
1958
1959         if (IS_NOQUOTA(inode))
1960                 return 0;
1961
1962         if (inode->i_sb->dq_op->get_inode_usage) {
1963                 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage);
1964                 if (ret)
1965                         return ret;
1966         }
1967
1968         /* Initialize the arrays */
1969         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1970                 warn_to[cnt].w_type = QUOTA_NL_NOWARN;
1971                 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN;
1972                 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN;
1973         }
1974
1975         spin_lock(&dq_data_lock);
1976         spin_lock(&inode->i_lock);
1977         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1978                 spin_unlock(&inode->i_lock);
1979                 spin_unlock(&dq_data_lock);
1980                 return 0;
1981         }
1982         cur_space = __inode_get_bytes(inode);
1983         rsv_space = __inode_get_rsv_space(inode);
1984         /*
1985          * Build the transfer_from list, check limits, and update usage in
1986          * the target structures.
1987          */
1988         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1989                 /*
1990                  * Skip changes for same uid or gid or for turned off quota-type.
1991                  */
1992                 if (!transfer_to[cnt])
1993                         continue;
1994                 /* Avoid races with quotaoff() */
1995                 if (!sb_has_quota_active(inode->i_sb, cnt))
1996                         continue;
1997                 is_valid[cnt] = 1;
1998                 transfer_from[cnt] = i_dquot(inode)[cnt];
1999                 ret = dquot_add_inodes(transfer_to[cnt], inode_usage,
2000                                        &warn_to[cnt]);
2001                 if (ret)
2002                         goto over_quota;
2003                 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space,
2004                                       DQUOT_SPACE_WARN, &warn_to[cnt]);
2005                 if (ret) {
2006                         spin_lock(&transfer_to[cnt]->dq_dqb_lock);
2007                         dquot_decr_inodes(transfer_to[cnt], inode_usage);
2008                         spin_unlock(&transfer_to[cnt]->dq_dqb_lock);
2009                         goto over_quota;
2010                 }
2011         }
2012
2013         /* Decrease usage for source structures and update quota pointers */
2014         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2015                 if (!is_valid[cnt])
2016                         continue;
2017                 /* Due to IO error we might not have transfer_from[] structure */
2018                 if (transfer_from[cnt]) {
2019                         int wtype;
2020
2021                         spin_lock(&transfer_from[cnt]->dq_dqb_lock);
2022                         wtype = info_idq_free(transfer_from[cnt], inode_usage);
2023                         if (wtype != QUOTA_NL_NOWARN)
2024                                 prepare_warning(&warn_from_inodes[cnt],
2025                                                 transfer_from[cnt], wtype);
2026                         wtype = info_bdq_free(transfer_from[cnt],
2027                                               cur_space + rsv_space);
2028                         if (wtype != QUOTA_NL_NOWARN)
2029                                 prepare_warning(&warn_from_space[cnt],
2030                                                 transfer_from[cnt], wtype);
2031                         dquot_decr_inodes(transfer_from[cnt], inode_usage);
2032                         dquot_decr_space(transfer_from[cnt], cur_space);
2033                         dquot_free_reserved_space(transfer_from[cnt],
2034                                                   rsv_space);
2035                         spin_unlock(&transfer_from[cnt]->dq_dqb_lock);
2036                 }
2037                 i_dquot(inode)[cnt] = transfer_to[cnt];
2038         }
2039         spin_unlock(&inode->i_lock);
2040         spin_unlock(&dq_data_lock);
2041
2042         mark_all_dquot_dirty(transfer_from);
2043         mark_all_dquot_dirty(transfer_to);
2044         flush_warnings(warn_to);
2045         flush_warnings(warn_from_inodes);
2046         flush_warnings(warn_from_space);
2047         /* Pass back references to put */
2048         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2049                 if (is_valid[cnt])
2050                         transfer_to[cnt] = transfer_from[cnt];
2051         return 0;
2052 over_quota:
2053         /* Back out changes we already did */
2054         for (cnt--; cnt >= 0; cnt--) {
2055                 if (!is_valid[cnt])
2056                         continue;
2057                 spin_lock(&transfer_to[cnt]->dq_dqb_lock);
2058                 dquot_decr_inodes(transfer_to[cnt], inode_usage);
2059                 dquot_decr_space(transfer_to[cnt], cur_space);
2060                 dquot_free_reserved_space(transfer_to[cnt], rsv_space);
2061                 spin_unlock(&transfer_to[cnt]->dq_dqb_lock);
2062         }
2063         spin_unlock(&inode->i_lock);
2064         spin_unlock(&dq_data_lock);
2065         flush_warnings(warn_to);
2066         return ret;
2067 }
2068 EXPORT_SYMBOL(__dquot_transfer);
2069
2070 /* Wrapper for transferring ownership of an inode for uid/gid only
2071  * Called from FSXXX_setattr()
2072  */
2073 int dquot_transfer(struct inode *inode, struct iattr *iattr)
2074 {
2075         struct dquot *transfer_to[MAXQUOTAS] = {};
2076         struct dquot *dquot;
2077         struct super_block *sb = inode->i_sb;
2078         int ret;
2079
2080         if (!dquot_active(inode))
2081                 return 0;
2082
2083         if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){
2084                 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid));
2085                 if (IS_ERR(dquot)) {
2086                         if (PTR_ERR(dquot) != -ESRCH) {
2087                                 ret = PTR_ERR(dquot);
2088                                 goto out_put;
2089                         }
2090                         dquot = NULL;
2091                 }
2092                 transfer_to[USRQUOTA] = dquot;
2093         }
2094         if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){
2095                 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid));
2096                 if (IS_ERR(dquot)) {
2097                         if (PTR_ERR(dquot) != -ESRCH) {
2098                                 ret = PTR_ERR(dquot);
2099                                 goto out_put;
2100                         }
2101                         dquot = NULL;
2102                 }
2103                 transfer_to[GRPQUOTA] = dquot;
2104         }
2105         ret = __dquot_transfer(inode, transfer_to);
2106 out_put:
2107         dqput_all(transfer_to);
2108         return ret;
2109 }
2110 EXPORT_SYMBOL(dquot_transfer);
2111
2112 /*
2113  * Write info of quota file to disk
2114  */
2115 int dquot_commit_info(struct super_block *sb, int type)
2116 {
2117         struct quota_info *dqopt = sb_dqopt(sb);
2118
2119         return dqopt->ops[type]->write_file_info(sb, type);
2120 }
2121 EXPORT_SYMBOL(dquot_commit_info);
2122
2123 int dquot_get_next_id(struct super_block *sb, struct kqid *qid)
2124 {
2125         struct quota_info *dqopt = sb_dqopt(sb);
2126
2127         if (!sb_has_quota_active(sb, qid->type))
2128                 return -ESRCH;
2129         if (!dqopt->ops[qid->type]->get_next_id)
2130                 return -ENOSYS;
2131         return dqopt->ops[qid->type]->get_next_id(sb, qid);
2132 }
2133 EXPORT_SYMBOL(dquot_get_next_id);
2134
2135 /*
2136  * Definitions of diskquota operations.
2137  */
2138 const struct dquot_operations dquot_operations = {
2139         .write_dquot    = dquot_commit,
2140         .acquire_dquot  = dquot_acquire,
2141         .release_dquot  = dquot_release,
2142         .mark_dirty     = dquot_mark_dquot_dirty,
2143         .write_info     = dquot_commit_info,
2144         .alloc_dquot    = dquot_alloc,
2145         .destroy_dquot  = dquot_destroy,
2146         .get_next_id    = dquot_get_next_id,
2147 };
2148 EXPORT_SYMBOL(dquot_operations);
2149
2150 /*
2151  * Generic helper for ->open on filesystems supporting disk quotas.
2152  */
2153 int dquot_file_open(struct inode *inode, struct file *file)
2154 {
2155         int error;
2156
2157         error = generic_file_open(inode, file);
2158         if (!error && (file->f_mode & FMODE_WRITE))
2159                 error = dquot_initialize(inode);
2160         return error;
2161 }
2162 EXPORT_SYMBOL(dquot_file_open);
2163
2164 static void vfs_cleanup_quota_inode(struct super_block *sb, int type)
2165 {
2166         struct quota_info *dqopt = sb_dqopt(sb);
2167         struct inode *inode = dqopt->files[type];
2168
2169         if (!inode)
2170                 return;
2171         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2172                 inode_lock(inode);
2173                 inode->i_flags &= ~S_NOQUOTA;
2174                 inode_unlock(inode);
2175         }
2176         dqopt->files[type] = NULL;
2177         iput(inode);
2178 }
2179
2180 /*
2181  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
2182  */
2183 int dquot_disable(struct super_block *sb, int type, unsigned int flags)
2184 {
2185         int cnt;
2186         struct quota_info *dqopt = sb_dqopt(sb);
2187
2188         /* s_umount should be held in exclusive mode */
2189         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2190                 up_read(&sb->s_umount);
2191
2192         /* Cannot turn off usage accounting without turning off limits, or
2193          * suspend quotas and simultaneously turn quotas off. */
2194         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
2195             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
2196             DQUOT_USAGE_ENABLED)))
2197                 return -EINVAL;
2198
2199         /*
2200          * Skip everything if there's nothing to do. We have to do this because
2201          * sometimes we are called when fill_super() failed and calling
2202          * sync_fs() in such cases does no good.
2203          */
2204         if (!sb_any_quota_loaded(sb))
2205                 return 0;
2206
2207         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2208                 if (type != -1 && cnt != type)
2209                         continue;
2210                 if (!sb_has_quota_loaded(sb, cnt))
2211                         continue;
2212
2213                 if (flags & DQUOT_SUSPENDED) {
2214                         spin_lock(&dq_state_lock);
2215                         dqopt->flags |=
2216                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
2217                         spin_unlock(&dq_state_lock);
2218                 } else {
2219                         spin_lock(&dq_state_lock);
2220                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
2221                         /* Turning off suspended quotas? */
2222                         if (!sb_has_quota_loaded(sb, cnt) &&
2223                             sb_has_quota_suspended(sb, cnt)) {
2224                                 dqopt->flags &= ~dquot_state_flag(
2225                                                         DQUOT_SUSPENDED, cnt);
2226                                 spin_unlock(&dq_state_lock);
2227                                 vfs_cleanup_quota_inode(sb, cnt);
2228                                 continue;
2229                         }
2230                         spin_unlock(&dq_state_lock);
2231                 }
2232
2233                 /* We still have to keep quota loaded? */
2234                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
2235                         continue;
2236
2237                 /* Note: these are blocking operations */
2238                 drop_dquot_ref(sb, cnt);
2239                 invalidate_dquots(sb, cnt);
2240                 /*
2241                  * Now all dquots should be invalidated, all writes done so we
2242                  * should be only users of the info. No locks needed.
2243                  */
2244                 if (info_dirty(&dqopt->info[cnt]))
2245                         sb->dq_op->write_info(sb, cnt);
2246                 if (dqopt->ops[cnt]->free_file_info)
2247                         dqopt->ops[cnt]->free_file_info(sb, cnt);
2248                 put_quota_format(dqopt->info[cnt].dqi_format);
2249                 dqopt->info[cnt].dqi_flags = 0;
2250                 dqopt->info[cnt].dqi_igrace = 0;
2251                 dqopt->info[cnt].dqi_bgrace = 0;
2252                 dqopt->ops[cnt] = NULL;
2253         }
2254
2255         /* Skip syncing and setting flags if quota files are hidden */
2256         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
2257                 goto put_inodes;
2258
2259         /* Sync the superblock so that buffers with quota data are written to
2260          * disk (and so userspace sees correct data afterwards). */
2261         if (sb->s_op->sync_fs)
2262                 sb->s_op->sync_fs(sb, 1);
2263         sync_blockdev(sb->s_bdev);
2264         /* Now the quota files are just ordinary files and we can set the
2265          * inode flags back. Moreover we discard the pagecache so that
2266          * userspace sees the writes we did bypassing the pagecache. We
2267          * must also discard the blockdev buffers so that we see the
2268          * changes done by userspace on the next quotaon() */
2269         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2270                 if (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) {
2271                         inode_lock(dqopt->files[cnt]);
2272                         truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
2273                         inode_unlock(dqopt->files[cnt]);
2274                 }
2275         if (sb->s_bdev)
2276                 invalidate_bdev(sb->s_bdev);
2277 put_inodes:
2278         /* We are done when suspending quotas */
2279         if (flags & DQUOT_SUSPENDED)
2280                 return 0;
2281
2282         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2283                 if (!sb_has_quota_loaded(sb, cnt))
2284                         vfs_cleanup_quota_inode(sb, cnt);
2285         return 0;
2286 }
2287 EXPORT_SYMBOL(dquot_disable);
2288
2289 int dquot_quota_off(struct super_block *sb, int type)
2290 {
2291         return dquot_disable(sb, type,
2292                              DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2293 }
2294 EXPORT_SYMBOL(dquot_quota_off);
2295
2296 /*
2297  *      Turn quotas on on a device
2298  */
2299
2300 static int vfs_setup_quota_inode(struct inode *inode, int type)
2301 {
2302         struct super_block *sb = inode->i_sb;
2303         struct quota_info *dqopt = sb_dqopt(sb);
2304
2305         if (!S_ISREG(inode->i_mode))
2306                 return -EACCES;
2307         if (IS_RDONLY(inode))
2308                 return -EROFS;
2309         if (sb_has_quota_loaded(sb, type))
2310                 return -EBUSY;
2311
2312         dqopt->files[type] = igrab(inode);
2313         if (!dqopt->files[type])
2314                 return -EIO;
2315         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2316                 /* We don't want quota and atime on quota files (deadlocks
2317                  * possible) Also nobody should write to the file - we use
2318                  * special IO operations which ignore the immutable bit. */
2319                 inode_lock(inode);
2320                 inode->i_flags |= S_NOQUOTA;
2321                 inode_unlock(inode);
2322                 /*
2323                  * When S_NOQUOTA is set, remove dquot references as no more
2324                  * references can be added
2325                  */
2326                 __dquot_drop(inode);
2327         }
2328         return 0;
2329 }
2330
2331 int dquot_load_quota_sb(struct super_block *sb, int type, int format_id,
2332         unsigned int flags)
2333 {
2334         struct quota_format_type *fmt = find_quota_format(format_id);
2335         struct quota_info *dqopt = sb_dqopt(sb);
2336         int error;
2337
2338         /* Just unsuspend quotas? */
2339         BUG_ON(flags & DQUOT_SUSPENDED);
2340         /* s_umount should be held in exclusive mode */
2341         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2342                 up_read(&sb->s_umount);
2343
2344         if (!fmt)
2345                 return -ESRCH;
2346         if (!sb->s_op->quota_write || !sb->s_op->quota_read ||
2347             (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) {
2348                 error = -EINVAL;
2349                 goto out_fmt;
2350         }
2351         /* Filesystems outside of init_user_ns not yet supported */
2352         if (sb->s_user_ns != &init_user_ns) {
2353                 error = -EINVAL;
2354                 goto out_fmt;
2355         }
2356         /* Usage always has to be set... */
2357         if (!(flags & DQUOT_USAGE_ENABLED)) {
2358                 error = -EINVAL;
2359                 goto out_fmt;
2360         }
2361         if (sb_has_quota_loaded(sb, type)) {
2362                 error = -EBUSY;
2363                 goto out_fmt;
2364         }
2365
2366         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2367                 /* As we bypass the pagecache we must now flush all the
2368                  * dirty data and invalidate caches so that kernel sees
2369                  * changes from userspace. It is not enough to just flush
2370                  * the quota file since if blocksize < pagesize, invalidation
2371                  * of the cache could fail because of other unrelated dirty
2372                  * data */
2373                 sync_filesystem(sb);
2374                 invalidate_bdev(sb->s_bdev);
2375         }
2376
2377         error = -EINVAL;
2378         if (!fmt->qf_ops->check_quota_file(sb, type))
2379                 goto out_fmt;
2380
2381         dqopt->ops[type] = fmt->qf_ops;
2382         dqopt->info[type].dqi_format = fmt;
2383         dqopt->info[type].dqi_fmt_id = format_id;
2384         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2385         error = dqopt->ops[type]->read_file_info(sb, type);
2386         if (error < 0)
2387                 goto out_fmt;
2388         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) {
2389                 spin_lock(&dq_data_lock);
2390                 dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
2391                 spin_unlock(&dq_data_lock);
2392         }
2393         spin_lock(&dq_state_lock);
2394         dqopt->flags |= dquot_state_flag(flags, type);
2395         spin_unlock(&dq_state_lock);
2396
2397         error = add_dquot_ref(sb, type);
2398         if (error)
2399                 dquot_disable(sb, type, flags);
2400
2401         return error;
2402 out_fmt:
2403         put_quota_format(fmt);
2404
2405         return error;
2406 }
2407 EXPORT_SYMBOL(dquot_load_quota_sb);
2408
2409 /*
2410  * More powerful function for turning on quotas on given quota inode allowing
2411  * setting of individual quota flags
2412  */
2413 int dquot_load_quota_inode(struct inode *inode, int type, int format_id,
2414         unsigned int flags)
2415 {
2416         int err;
2417
2418         err = vfs_setup_quota_inode(inode, type);
2419         if (err < 0)
2420                 return err;
2421         err = dquot_load_quota_sb(inode->i_sb, type, format_id, flags);
2422         if (err < 0)
2423                 vfs_cleanup_quota_inode(inode->i_sb, type);
2424         return err;
2425 }
2426 EXPORT_SYMBOL(dquot_load_quota_inode);
2427
2428 /* Reenable quotas on remount RW */
2429 int dquot_resume(struct super_block *sb, int type)
2430 {
2431         struct quota_info *dqopt = sb_dqopt(sb);
2432         int ret = 0, cnt;
2433         unsigned int flags;
2434
2435         /* s_umount should be held in exclusive mode */
2436         if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2437                 up_read(&sb->s_umount);
2438
2439         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2440                 if (type != -1 && cnt != type)
2441                         continue;
2442                 if (!sb_has_quota_suspended(sb, cnt))
2443                         continue;
2444
2445                 spin_lock(&dq_state_lock);
2446                 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2447                                                         DQUOT_LIMITS_ENABLED,
2448                                                         cnt);
2449                 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
2450                 spin_unlock(&dq_state_lock);
2451
2452                 flags = dquot_generic_flag(flags, cnt);
2453                 ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id,
2454                                           flags);
2455                 if (ret < 0)
2456                         vfs_cleanup_quota_inode(sb, cnt);
2457         }
2458
2459         return ret;
2460 }
2461 EXPORT_SYMBOL(dquot_resume);
2462
2463 int dquot_quota_on(struct super_block *sb, int type, int format_id,
2464                    const struct path *path)
2465 {
2466         int error = security_quota_on(path->dentry);
2467         if (error)
2468                 return error;
2469         /* Quota file not on the same filesystem? */
2470         if (path->dentry->d_sb != sb)
2471                 error = -EXDEV;
2472         else
2473                 error = dquot_load_quota_inode(d_inode(path->dentry), type,
2474                                              format_id, DQUOT_USAGE_ENABLED |
2475                                              DQUOT_LIMITS_ENABLED);
2476         return error;
2477 }
2478 EXPORT_SYMBOL(dquot_quota_on);
2479
2480 /*
2481  * This function is used when filesystem needs to initialize quotas
2482  * during mount time.
2483  */
2484 int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
2485                 int format_id, int type)
2486 {
2487         struct dentry *dentry;
2488         int error;
2489
2490         dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name));
2491         if (IS_ERR(dentry))
2492                 return PTR_ERR(dentry);
2493
2494         error = security_quota_on(dentry);
2495         if (!error)
2496                 error = dquot_load_quota_inode(d_inode(dentry), type, format_id,
2497                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2498
2499         dput(dentry);
2500         return error;
2501 }
2502 EXPORT_SYMBOL(dquot_quota_on_mount);
2503
2504 static int dquot_quota_enable(struct super_block *sb, unsigned int flags)
2505 {
2506         int ret;
2507         int type;
2508         struct quota_info *dqopt = sb_dqopt(sb);
2509
2510         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
2511                 return -ENOSYS;
2512         /* Accounting cannot be turned on while fs is mounted */
2513         flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT);
2514         if (!flags)
2515                 return -EINVAL;
2516         for (type = 0; type < MAXQUOTAS; type++) {
2517                 if (!(flags & qtype_enforce_flag(type)))
2518                         continue;
2519                 /* Can't enforce without accounting */
2520                 if (!sb_has_quota_usage_enabled(sb, type)) {
2521                         ret = -EINVAL;
2522                         goto out_err;
2523                 }
2524                 if (sb_has_quota_limits_enabled(sb, type)) {
2525                         ret = -EBUSY;
2526                         goto out_err;
2527                 }
2528                 spin_lock(&dq_state_lock);
2529                 dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type);
2530                 spin_unlock(&dq_state_lock);
2531         }
2532         return 0;
2533 out_err:
2534         /* Backout enforcement enablement we already did */
2535         for (type--; type >= 0; type--)  {
2536                 if (flags & qtype_enforce_flag(type))
2537                         dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
2538         }
2539         /* Error code translation for better compatibility with XFS */
2540         if (ret == -EBUSY)
2541                 ret = -EEXIST;
2542         return ret;
2543 }
2544
2545 static int dquot_quota_disable(struct super_block *sb, unsigned int flags)
2546 {
2547         int ret;
2548         int type;
2549         struct quota_info *dqopt = sb_dqopt(sb);
2550
2551         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
2552                 return -ENOSYS;
2553         /*
2554          * We don't support turning off accounting via quotactl. In principle
2555          * quota infrastructure can do this but filesystems don't expect
2556          * userspace to be able to do it.
2557          */
2558         if (flags &
2559                   (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT))
2560                 return -EOPNOTSUPP;
2561
2562         /* Filter out limits not enabled */
2563         for (type = 0; type < MAXQUOTAS; type++)
2564                 if (!sb_has_quota_limits_enabled(sb, type))
2565                         flags &= ~qtype_enforce_flag(type);
2566         /* Nothing left? */
2567         if (!flags)
2568                 return -EEXIST;
2569         for (type = 0; type < MAXQUOTAS; type++) {
2570                 if (flags & qtype_enforce_flag(type)) {
2571                         ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
2572                         if (ret < 0)
2573                                 goto out_err;
2574                 }
2575         }
2576         return 0;
2577 out_err:
2578         /* Backout enforcement disabling we already did */
2579         for (type--; type >= 0; type--)  {
2580                 if (flags & qtype_enforce_flag(type)) {
2581                         spin_lock(&dq_state_lock);
2582                         dqopt->flags |=
2583                                 dquot_state_flag(DQUOT_LIMITS_ENABLED, type);
2584                         spin_unlock(&dq_state_lock);
2585                 }
2586         }
2587         return ret;
2588 }
2589
2590 /* Generic routine for getting common part of quota structure */
2591 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di)
2592 {
2593         struct mem_dqblk *dm = &dquot->dq_dqb;
2594
2595         memset(di, 0, sizeof(*di));
2596         spin_lock(&dquot->dq_dqb_lock);
2597         di->d_spc_hardlimit = dm->dqb_bhardlimit;
2598         di->d_spc_softlimit = dm->dqb_bsoftlimit;
2599         di->d_ino_hardlimit = dm->dqb_ihardlimit;
2600         di->d_ino_softlimit = dm->dqb_isoftlimit;
2601         di->d_space = dm->dqb_curspace + dm->dqb_rsvspace;
2602         di->d_ino_count = dm->dqb_curinodes;
2603         di->d_spc_timer = dm->dqb_btime;
2604         di->d_ino_timer = dm->dqb_itime;
2605         spin_unlock(&dquot->dq_dqb_lock);
2606 }
2607
2608 int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
2609                     struct qc_dqblk *di)
2610 {
2611         struct dquot *dquot;
2612
2613         dquot = dqget(sb, qid);
2614         if (IS_ERR(dquot))
2615                 return PTR_ERR(dquot);
2616         do_get_dqblk(dquot, di);
2617         dqput(dquot);
2618
2619         return 0;
2620 }
2621 EXPORT_SYMBOL(dquot_get_dqblk);
2622
2623 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid,
2624                          struct qc_dqblk *di)
2625 {
2626         struct dquot *dquot;
2627         int err;
2628
2629         if (!sb->dq_op->get_next_id)
2630                 return -ENOSYS;
2631         err = sb->dq_op->get_next_id(sb, qid);
2632         if (err < 0)
2633                 return err;
2634         dquot = dqget(sb, *qid);
2635         if (IS_ERR(dquot))
2636                 return PTR_ERR(dquot);
2637         do_get_dqblk(dquot, di);
2638         dqput(dquot);
2639
2640         return 0;
2641 }
2642 EXPORT_SYMBOL(dquot_get_next_dqblk);
2643
2644 #define VFS_QC_MASK \
2645         (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \
2646          QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \
2647          QC_SPC_TIMER | QC_INO_TIMER)
2648
2649 /* Generic routine for setting common part of quota structure */
2650 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di)
2651 {
2652         struct mem_dqblk *dm = &dquot->dq_dqb;
2653         int check_blim = 0, check_ilim = 0;
2654         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
2655
2656         if (di->d_fieldmask & ~VFS_QC_MASK)
2657                 return -EINVAL;
2658
2659         if (((di->d_fieldmask & QC_SPC_SOFT) &&
2660              di->d_spc_softlimit > dqi->dqi_max_spc_limit) ||
2661             ((di->d_fieldmask & QC_SPC_HARD) &&
2662              di->d_spc_hardlimit > dqi->dqi_max_spc_limit) ||
2663             ((di->d_fieldmask & QC_INO_SOFT) &&
2664              (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) ||
2665             ((di->d_fieldmask & QC_INO_HARD) &&
2666              (di->d_ino_hardlimit > dqi->dqi_max_ino_limit)))
2667                 return -ERANGE;
2668
2669         spin_lock(&dquot->dq_dqb_lock);
2670         if (di->d_fieldmask & QC_SPACE) {
2671                 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace;
2672                 check_blim = 1;
2673                 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2674         }
2675
2676         if (di->d_fieldmask & QC_SPC_SOFT)
2677                 dm->dqb_bsoftlimit = di->d_spc_softlimit;
2678         if (di->d_fieldmask & QC_SPC_HARD)
2679                 dm->dqb_bhardlimit = di->d_spc_hardlimit;
2680         if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) {
2681                 check_blim = 1;
2682                 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2683         }
2684
2685         if (di->d_fieldmask & QC_INO_COUNT) {
2686                 dm->dqb_curinodes = di->d_ino_count;
2687                 check_ilim = 1;
2688                 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2689         }
2690
2691         if (di->d_fieldmask & QC_INO_SOFT)
2692                 dm->dqb_isoftlimit = di->d_ino_softlimit;
2693         if (di->d_fieldmask & QC_INO_HARD)
2694                 dm->dqb_ihardlimit = di->d_ino_hardlimit;
2695         if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) {
2696                 check_ilim = 1;
2697                 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2698         }
2699
2700         if (di->d_fieldmask & QC_SPC_TIMER) {
2701                 dm->dqb_btime = di->d_spc_timer;
2702                 check_blim = 1;
2703                 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2704         }
2705
2706         if (di->d_fieldmask & QC_INO_TIMER) {
2707                 dm->dqb_itime = di->d_ino_timer;
2708                 check_ilim = 1;
2709                 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2710         }
2711
2712         if (check_blim) {
2713                 if (!dm->dqb_bsoftlimit ||
2714                     dm->dqb_curspace + dm->dqb_rsvspace <= dm->dqb_bsoftlimit) {
2715                         dm->dqb_btime = 0;
2716                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2717                 } else if (!(di->d_fieldmask & QC_SPC_TIMER))
2718                         /* Set grace only if user hasn't provided his own... */
2719                         dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace;
2720         }
2721         if (check_ilim) {
2722                 if (!dm->dqb_isoftlimit ||
2723                     dm->dqb_curinodes <= dm->dqb_isoftlimit) {
2724                         dm->dqb_itime = 0;
2725                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2726                 } else if (!(di->d_fieldmask & QC_INO_TIMER))
2727                         /* Set grace only if user hasn't provided his own... */
2728                         dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace;
2729         }
2730         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2731             dm->dqb_isoftlimit)
2732                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2733         else
2734                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2735         spin_unlock(&dquot->dq_dqb_lock);
2736         mark_dquot_dirty(dquot);
2737
2738         return 0;
2739 }
2740
2741 int dquot_set_dqblk(struct super_block *sb, struct kqid qid,
2742                   struct qc_dqblk *di)
2743 {
2744         struct dquot *dquot;
2745         int rc;
2746
2747         dquot = dqget(sb, qid);
2748         if (IS_ERR(dquot)) {
2749                 rc = PTR_ERR(dquot);
2750                 goto out;
2751         }
2752         rc = do_set_dqblk(dquot, di);
2753         dqput(dquot);
2754 out:
2755         return rc;
2756 }
2757 EXPORT_SYMBOL(dquot_set_dqblk);
2758
2759 /* Generic routine for getting common part of quota file information */
2760 int dquot_get_state(struct super_block *sb, struct qc_state *state)
2761 {
2762         struct mem_dqinfo *mi;
2763         struct qc_type_state *tstate;
2764         struct quota_info *dqopt = sb_dqopt(sb);
2765         int type;
2766
2767         memset(state, 0, sizeof(*state));
2768         for (type = 0; type < MAXQUOTAS; type++) {
2769                 if (!sb_has_quota_active(sb, type))
2770                         continue;
2771                 tstate = state->s_state + type;
2772                 mi = sb_dqopt(sb)->info + type;
2773                 tstate->flags = QCI_ACCT_ENABLED;
2774                 spin_lock(&dq_data_lock);
2775                 if (mi->dqi_flags & DQF_SYS_FILE)
2776                         tstate->flags |= QCI_SYSFILE;
2777                 if (mi->dqi_flags & DQF_ROOT_SQUASH)
2778                         tstate->flags |= QCI_ROOT_SQUASH;
2779                 if (sb_has_quota_limits_enabled(sb, type))
2780                         tstate->flags |= QCI_LIMITS_ENFORCED;
2781                 tstate->spc_timelimit = mi->dqi_bgrace;
2782                 tstate->ino_timelimit = mi->dqi_igrace;
2783                 if (dqopt->files[type]) {
2784                         tstate->ino = dqopt->files[type]->i_ino;
2785                         tstate->blocks = dqopt->files[type]->i_blocks;
2786                 }
2787                 tstate->nextents = 1;   /* We don't know... */
2788                 spin_unlock(&dq_data_lock);
2789         }
2790         return 0;
2791 }
2792 EXPORT_SYMBOL(dquot_get_state);
2793
2794 /* Generic routine for setting common part of quota file information */
2795 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii)
2796 {
2797         struct mem_dqinfo *mi;
2798         int err = 0;
2799
2800         if ((ii->i_fieldmask & QC_WARNS_MASK) ||
2801             (ii->i_fieldmask & QC_RT_SPC_TIMER))
2802                 return -EINVAL;
2803         if (!sb_has_quota_active(sb, type))
2804                 return -ESRCH;
2805         mi = sb_dqopt(sb)->info + type;
2806         if (ii->i_fieldmask & QC_FLAGS) {
2807                 if ((ii->i_flags & QCI_ROOT_SQUASH &&
2808                      mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD))
2809                         return -EINVAL;
2810         }
2811         spin_lock(&dq_data_lock);
2812         if (ii->i_fieldmask & QC_SPC_TIMER)
2813                 mi->dqi_bgrace = ii->i_spc_timelimit;
2814         if (ii->i_fieldmask & QC_INO_TIMER)
2815                 mi->dqi_igrace = ii->i_ino_timelimit;
2816         if (ii->i_fieldmask & QC_FLAGS) {
2817                 if (ii->i_flags & QCI_ROOT_SQUASH)
2818                         mi->dqi_flags |= DQF_ROOT_SQUASH;
2819                 else
2820                         mi->dqi_flags &= ~DQF_ROOT_SQUASH;
2821         }
2822         spin_unlock(&dq_data_lock);
2823         mark_info_dirty(sb, type);
2824         /* Force write to disk */
2825         sb->dq_op->write_info(sb, type);
2826         return err;
2827 }
2828 EXPORT_SYMBOL(dquot_set_dqinfo);
2829
2830 const struct quotactl_ops dquot_quotactl_sysfile_ops = {
2831         .quota_enable   = dquot_quota_enable,
2832         .quota_disable  = dquot_quota_disable,
2833         .quota_sync     = dquot_quota_sync,
2834         .get_state      = dquot_get_state,
2835         .set_info       = dquot_set_dqinfo,
2836         .get_dqblk      = dquot_get_dqblk,
2837         .get_nextdqblk  = dquot_get_next_dqblk,
2838         .set_dqblk      = dquot_set_dqblk
2839 };
2840 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);
2841
2842 static int do_proc_dqstats(struct ctl_table *table, int write,
2843                      void *buffer, size_t *lenp, loff_t *ppos)
2844 {
2845         unsigned int type = (unsigned long *)table->data - dqstats.stat;
2846         s64 value = percpu_counter_sum(&dqstats.counter[type]);
2847
2848         /* Filter negative values for non-monotonic counters */
2849         if (value < 0 && (type == DQST_ALLOC_DQUOTS ||
2850                           type == DQST_FREE_DQUOTS))
2851                 value = 0;
2852
2853         /* Update global table */
2854         dqstats.stat[type] = value;
2855         return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
2856 }
2857
2858 static struct ctl_table fs_dqstats_table[] = {
2859         {
2860                 .procname       = "lookups",
2861                 .data           = &dqstats.stat[DQST_LOOKUPS],
2862                 .maxlen         = sizeof(unsigned long),
2863                 .mode           = 0444,
2864                 .proc_handler   = do_proc_dqstats,
2865         },
2866         {
2867                 .procname       = "drops",
2868                 .data           = &dqstats.stat[DQST_DROPS],
2869                 .maxlen         = sizeof(unsigned long),
2870                 .mode           = 0444,
2871                 .proc_handler   = do_proc_dqstats,
2872         },
2873         {
2874                 .procname       = "reads",
2875                 .data           = &dqstats.stat[DQST_READS],
2876                 .maxlen         = sizeof(unsigned long),
2877                 .mode           = 0444,
2878                 .proc_handler   = do_proc_dqstats,
2879         },
2880         {
2881                 .procname       = "writes",
2882                 .data           = &dqstats.stat[DQST_WRITES],
2883                 .maxlen         = sizeof(unsigned long),
2884                 .mode           = 0444,
2885                 .proc_handler   = do_proc_dqstats,
2886         },
2887         {
2888                 .procname       = "cache_hits",
2889                 .data           = &dqstats.stat[DQST_CACHE_HITS],
2890                 .maxlen         = sizeof(unsigned long),
2891                 .mode           = 0444,
2892                 .proc_handler   = do_proc_dqstats,
2893         },
2894         {
2895                 .procname       = "allocated_dquots",
2896                 .data           = &dqstats.stat[DQST_ALLOC_DQUOTS],
2897                 .maxlen         = sizeof(unsigned long),
2898                 .mode           = 0444,
2899                 .proc_handler   = do_proc_dqstats,
2900         },
2901         {
2902                 .procname       = "free_dquots",
2903                 .data           = &dqstats.stat[DQST_FREE_DQUOTS],
2904                 .maxlen         = sizeof(unsigned long),
2905                 .mode           = 0444,
2906                 .proc_handler   = do_proc_dqstats,
2907         },
2908         {
2909                 .procname       = "syncs",
2910                 .data           = &dqstats.stat[DQST_SYNCS],
2911                 .maxlen         = sizeof(unsigned long),
2912                 .mode           = 0444,
2913                 .proc_handler   = do_proc_dqstats,
2914         },
2915 #ifdef CONFIG_PRINT_QUOTA_WARNING
2916         {
2917                 .procname       = "warnings",
2918                 .data           = &flag_print_warnings,
2919                 .maxlen         = sizeof(int),
2920                 .mode           = 0644,
2921                 .proc_handler   = proc_dointvec,
2922         },
2923 #endif
2924         { },
2925 };
2926
2927 static struct ctl_table fs_table[] = {
2928         {
2929                 .procname       = "quota",
2930                 .mode           = 0555,
2931                 .child          = fs_dqstats_table,
2932         },
2933         { },
2934 };
2935
2936 static struct ctl_table sys_table[] = {
2937         {
2938                 .procname       = "fs",
2939                 .mode           = 0555,
2940                 .child          = fs_table,
2941         },
2942         { },
2943 };
2944
2945 static int __init dquot_init(void)
2946 {
2947         int i, ret;
2948         unsigned long nr_hash, order;
2949
2950         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2951
2952         register_sysctl_table(sys_table);
2953
2954         dquot_cachep = kmem_cache_create("dquot",
2955                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2956                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2957                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2958                         NULL);
2959
2960         order = 0;
2961         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order);
2962         if (!dquot_hash)
2963                 panic("Cannot create dquot hash table");
2964
2965         for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
2966                 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL);
2967                 if (ret)
2968                         panic("Cannot create dquot stat counters");
2969         }
2970
2971         /* Find power-of-two hlist_heads which can fit into allocation */
2972         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2973         dq_hash_bits = ilog2(nr_hash);
2974
2975         nr_hash = 1UL << dq_hash_bits;
2976         dq_hash_mask = nr_hash - 1;
2977         for (i = 0; i < nr_hash; i++)
2978                 INIT_HLIST_HEAD(dquot_hash + i);
2979
2980         pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld,"
2981                 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order));
2982
2983         if (register_shrinker(&dqcache_shrinker))
2984                 panic("Cannot register dquot shrinker");
2985
2986         return 0;
2987 }
2988 fs_initcall(dquot_init);