e840fa2b112ec7ea15e0030cf2c5eda911be1467
[linux-2.6.git] / fs / quota / dquot.c
1 /*
2  * Implementation of the diskquota system for the LINUX operating system. QUOTA
3  * is implemented using the BSD system call interface as the means of
4  * communication with the user level. This file contains the generic routines
5  * called by the different filesystems on allocation of an inode or block.
6  * These routines take care of the administration needed to have a consistent
7  * diskquota tracking system. The ideas of both user and group quotas are based
8  * on the Melbourne quota system as used on BSD derived systems. The internal
9  * implementation is based on one of the several variants of the LINUX
10  * inode-subsystem with added complexity of the diskquota system.
11  * 
12  * Author:      Marco van Wieringen <mvw@planets.elm.net>
13  *
14  * Fixes:   Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
15  *
16  *              Revised list management to avoid races
17  *              -- Bill Hawes, <whawes@star.net>, 9/98
18  *
19  *              Fixed races in dquot_transfer(), dqget() and dquot_alloc_...().
20  *              As the consequence the locking was moved from dquot_decr_...(),
21  *              dquot_incr_...() to calling functions.
22  *              invalidate_dquots() now writes modified dquots.
23  *              Serialized quota_off() and quota_on() for mount point.
24  *              Fixed a few bugs in grow_dquots().
25  *              Fixed deadlock in write_dquot() - we no longer account quotas on
26  *              quota files
27  *              remove_dquot_ref() moved to inode.c - it now traverses through inodes
28  *              add_dquot_ref() restarts after blocking
29  *              Added check for bogus uid and fixed check for group in quotactl.
30  *              Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99
31  *
32  *              Used struct list_head instead of own list struct
33  *              Invalidation of referenced dquots is no longer possible
34  *              Improved free_dquots list management
35  *              Quota and i_blocks are now updated in one place to avoid races
36  *              Warnings are now delayed so we won't block in critical section
37  *              Write updated not to require dquot lock
38  *              Jan Kara, <jack@suse.cz>, 9/2000
39  *
40  *              Added dynamic quota structure allocation
41  *              Jan Kara <jack@suse.cz> 12/2000
42  *
43  *              Rewritten quota interface. Implemented new quota format and
44  *              formats registering.
45  *              Jan Kara, <jack@suse.cz>, 2001,2002
46  *
47  *              New SMP locking.
48  *              Jan Kara, <jack@suse.cz>, 10/2002
49  *
50  *              Added journalled quota support, fix lock inversion problems
51  *              Jan Kara, <jack@suse.cz>, 2003,2004
52  *
53  * (C) Copyright 1994 - 1997 Marco van Wieringen 
54  */
55
56 #include <linux/errno.h>
57 #include <linux/kernel.h>
58 #include <linux/fs.h>
59 #include <linux/mount.h>
60 #include <linux/mm.h>
61 #include <linux/time.h>
62 #include <linux/types.h>
63 #include <linux/string.h>
64 #include <linux/fcntl.h>
65 #include <linux/stat.h>
66 #include <linux/tty.h>
67 #include <linux/file.h>
68 #include <linux/slab.h>
69 #include <linux/sysctl.h>
70 #include <linux/init.h>
71 #include <linux/module.h>
72 #include <linux/proc_fs.h>
73 #include <linux/security.h>
74 #include <linux/kmod.h>
75 #include <linux/namei.h>
76 #include <linux/buffer_head.h>
77 #include <linux/capability.h>
78 #include <linux/quotaops.h>
79 #include <linux/writeback.h> /* for inode_lock, oddly enough.. */
80 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
81 #include <net/netlink.h>
82 #include <net/genetlink.h>
83 #endif
84
85 #include <asm/uaccess.h>
86
87 #define __DQUOT_PARANOIA
88
89 /*
90  * There are three quota SMP locks. dq_list_lock protects all lists with quotas
91  * and quota formats, dqstats structure containing statistics about the lists
92  * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
93  * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
94  * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
95  * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
96  * modifications of quota state (on quotaon and quotaoff) and readers who care
97  * about latest values take it as well.
98  *
99  * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_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  * Any operation working on dquots via inode pointers must hold dqptr_sem.  If
106  * operation is just reading pointers from inode (or not using them at all) the
107  * read lock is enough. If pointers are altered function must hold write lock
108  * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
109  * for altering the flag i_mutex is also needed).
110  *
111  * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
112  * from inodes (dquot_alloc_space() and such don't check the dq_lock).
113  * Currently dquot is locked only when it is being read to memory (or space for
114  * it is being allocated) on the first dqget() and when it is being released on
115  * the last dqput(). The allocation and release oparations are serialized by
116  * the dq_lock and by checking the use count in dquot_release().  Write
117  * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
118  * spinlock to internal buffers before writing.
119  *
120  * Lock ordering (including related VFS locks) is the following:
121  *   i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
122  *   dqio_mutex
123  * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem >
124  * dqptr_sem. But filesystem has to count with the fact that functions such as
125  * dquot_alloc_space() acquire dqptr_sem and they usually have to be called
126  * from inside a transaction to keep filesystem consistency after a crash. Also
127  * filesystems usually want to do some IO on dquot from ->mark_dirty which is
128  * called with dqptr_sem held.
129  * i_mutex on quota files is special (it's below dqio_mutex)
130  */
131
132 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
133 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
134 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
135 EXPORT_SYMBOL(dq_data_lock);
136
137 static char *quotatypes[] = INITQFNAMES;
138 static struct quota_format_type *quota_formats; /* List of registered formats */
139 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
140
141 /* SLAB cache for dquot structures */
142 static struct kmem_cache *dquot_cachep;
143
144 int register_quota_format(struct quota_format_type *fmt)
145 {
146         spin_lock(&dq_list_lock);
147         fmt->qf_next = quota_formats;
148         quota_formats = fmt;
149         spin_unlock(&dq_list_lock);
150         return 0;
151 }
152 EXPORT_SYMBOL(register_quota_format);
153
154 void unregister_quota_format(struct quota_format_type *fmt)
155 {
156         struct quota_format_type **actqf;
157
158         spin_lock(&dq_list_lock);
159         for (actqf = &quota_formats; *actqf && *actqf != fmt; actqf = &(*actqf)->qf_next);
160         if (*actqf)
161                 *actqf = (*actqf)->qf_next;
162         spin_unlock(&dq_list_lock);
163 }
164 EXPORT_SYMBOL(unregister_quota_format);
165
166 static struct quota_format_type *find_quota_format(int id)
167 {
168         struct quota_format_type *actqf;
169
170         spin_lock(&dq_list_lock);
171         for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
172         if (!actqf || !try_module_get(actqf->qf_owner)) {
173                 int qm;
174
175                 spin_unlock(&dq_list_lock);
176                 
177                 for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++);
178                 if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name))
179                         return NULL;
180
181                 spin_lock(&dq_list_lock);
182                 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
183                 if (actqf && !try_module_get(actqf->qf_owner))
184                         actqf = NULL;
185         }
186         spin_unlock(&dq_list_lock);
187         return actqf;
188 }
189
190 static void put_quota_format(struct quota_format_type *fmt)
191 {
192         module_put(fmt->qf_owner);
193 }
194
195 /*
196  * Dquot List Management:
197  * The quota code uses three lists for dquot management: the inuse_list,
198  * free_dquots, and dquot_hash[] array. A single dquot structure may be
199  * on all three lists, depending on its current state.
200  *
201  * All dquots are placed to the end of inuse_list when first created, and this
202  * list is used for invalidate operation, which must look at every dquot.
203  *
204  * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
205  * and this list is searched whenever we need an available dquot.  Dquots are
206  * removed from the list as soon as they are used again, and
207  * dqstats.free_dquots gives the number of dquots on the list. When
208  * dquot is invalidated it's completely released from memory.
209  *
210  * Dquots with a specific identity (device, type and id) are placed on
211  * one of the dquot_hash[] hash chains. The provides an efficient search
212  * mechanism to locate a specific dquot.
213  */
214
215 static LIST_HEAD(inuse_list);
216 static LIST_HEAD(free_dquots);
217 static unsigned int dq_hash_bits, dq_hash_mask;
218 static struct hlist_head *dquot_hash;
219
220 struct dqstats dqstats;
221 EXPORT_SYMBOL(dqstats);
222
223 static inline unsigned int
224 hashfn(const struct super_block *sb, unsigned int id, int type)
225 {
226         unsigned long tmp;
227
228         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
229         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
230 }
231
232 /*
233  * Following list functions expect dq_list_lock to be held
234  */
235 static inline void insert_dquot_hash(struct dquot *dquot)
236 {
237         struct hlist_head *head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
238         hlist_add_head(&dquot->dq_hash, head);
239 }
240
241 static inline void remove_dquot_hash(struct dquot *dquot)
242 {
243         hlist_del_init(&dquot->dq_hash);
244 }
245
246 static inline struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, unsigned int id, int type)
247 {
248         struct hlist_node *node;
249         struct dquot *dquot;
250
251         hlist_for_each (node, dquot_hash+hashent) {
252                 dquot = hlist_entry(node, struct dquot, dq_hash);
253                 if (dquot->dq_sb == sb && dquot->dq_id == id && dquot->dq_type == type)
254                         return dquot;
255         }
256         return NODQUOT;
257 }
258
259 /* Add a dquot to the tail of the free list */
260 static inline void put_dquot_last(struct dquot *dquot)
261 {
262         list_add_tail(&dquot->dq_free, &free_dquots);
263         dqstats.free_dquots++;
264 }
265
266 static inline void remove_free_dquot(struct dquot *dquot)
267 {
268         if (list_empty(&dquot->dq_free))
269                 return;
270         list_del_init(&dquot->dq_free);
271         dqstats.free_dquots--;
272 }
273
274 static inline void put_inuse(struct dquot *dquot)
275 {
276         /* We add to the back of inuse list so we don't have to restart
277          * when traversing this list and we block */
278         list_add_tail(&dquot->dq_inuse, &inuse_list);
279         dqstats.allocated_dquots++;
280 }
281
282 static inline void remove_inuse(struct dquot *dquot)
283 {
284         dqstats.allocated_dquots--;
285         list_del(&dquot->dq_inuse);
286 }
287 /*
288  * End of list functions needing dq_list_lock
289  */
290
291 static void wait_on_dquot(struct dquot *dquot)
292 {
293         mutex_lock(&dquot->dq_lock);
294         mutex_unlock(&dquot->dq_lock);
295 }
296
297 static inline int dquot_dirty(struct dquot *dquot)
298 {
299         return test_bit(DQ_MOD_B, &dquot->dq_flags);
300 }
301
302 static inline int mark_dquot_dirty(struct dquot *dquot)
303 {
304         return dquot->dq_sb->dq_op->mark_dirty(dquot);
305 }
306
307 int dquot_mark_dquot_dirty(struct dquot *dquot)
308 {
309         spin_lock(&dq_list_lock);
310         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
311                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
312                                 info[dquot->dq_type].dqi_dirty_list);
313         spin_unlock(&dq_list_lock);
314         return 0;
315 }
316 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
317
318 /* This function needs dq_list_lock */
319 static inline int clear_dquot_dirty(struct dquot *dquot)
320 {
321         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
322                 return 0;
323         list_del_init(&dquot->dq_dirty);
324         return 1;
325 }
326
327 void mark_info_dirty(struct super_block *sb, int type)
328 {
329         set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
330 }
331 EXPORT_SYMBOL(mark_info_dirty);
332
333 /*
334  *      Read dquot from disk and alloc space for it
335  */
336
337 int dquot_acquire(struct dquot *dquot)
338 {
339         int ret = 0, ret2 = 0;
340         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
341
342         mutex_lock(&dquot->dq_lock);
343         mutex_lock(&dqopt->dqio_mutex);
344         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
345                 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
346         if (ret < 0)
347                 goto out_iolock;
348         set_bit(DQ_READ_B, &dquot->dq_flags);
349         /* Instantiate dquot if needed */
350         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
351                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
352                 /* Write the info if needed */
353                 if (info_dirty(&dqopt->info[dquot->dq_type]))
354                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
355                 if (ret < 0)
356                         goto out_iolock;
357                 if (ret2 < 0) {
358                         ret = ret2;
359                         goto out_iolock;
360                 }
361         }
362         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
363 out_iolock:
364         mutex_unlock(&dqopt->dqio_mutex);
365         mutex_unlock(&dquot->dq_lock);
366         return ret;
367 }
368 EXPORT_SYMBOL(dquot_acquire);
369
370 /*
371  *      Write dquot to disk
372  */
373 int dquot_commit(struct dquot *dquot)
374 {
375         int ret = 0, ret2 = 0;
376         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
377
378         mutex_lock(&dqopt->dqio_mutex);
379         spin_lock(&dq_list_lock);
380         if (!clear_dquot_dirty(dquot)) {
381                 spin_unlock(&dq_list_lock);
382                 goto out_sem;
383         }
384         spin_unlock(&dq_list_lock);
385         /* Inactive dquot can be only if there was error during read/init
386          * => we have better not writing it */
387         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
388                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
389                 if (info_dirty(&dqopt->info[dquot->dq_type]))
390                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
391                 if (ret >= 0)
392                         ret = ret2;
393         }
394 out_sem:
395         mutex_unlock(&dqopt->dqio_mutex);
396         return ret;
397 }
398 EXPORT_SYMBOL(dquot_commit);
399
400 /*
401  *      Release dquot
402  */
403 int dquot_release(struct dquot *dquot)
404 {
405         int ret = 0, ret2 = 0;
406         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
407
408         mutex_lock(&dquot->dq_lock);
409         /* Check whether we are not racing with some other dqget() */
410         if (atomic_read(&dquot->dq_count) > 1)
411                 goto out_dqlock;
412         mutex_lock(&dqopt->dqio_mutex);
413         if (dqopt->ops[dquot->dq_type]->release_dqblk) {
414                 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
415                 /* Write the info */
416                 if (info_dirty(&dqopt->info[dquot->dq_type]))
417                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
418                 if (ret >= 0)
419                         ret = ret2;
420         }
421         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
422         mutex_unlock(&dqopt->dqio_mutex);
423 out_dqlock:
424         mutex_unlock(&dquot->dq_lock);
425         return ret;
426 }
427 EXPORT_SYMBOL(dquot_release);
428
429 void dquot_destroy(struct dquot *dquot)
430 {
431         kmem_cache_free(dquot_cachep, dquot);
432 }
433 EXPORT_SYMBOL(dquot_destroy);
434
435 static inline void do_destroy_dquot(struct dquot *dquot)
436 {
437         dquot->dq_sb->dq_op->destroy_dquot(dquot);
438 }
439
440 /* Invalidate all dquots on the list. Note that this function is called after
441  * quota is disabled and pointers from inodes removed so there cannot be new
442  * quota users. There can still be some users of quotas due to inodes being
443  * just deleted or pruned by prune_icache() (those are not attached to any
444  * list) or parallel quotactl call. We have to wait for such users.
445  */
446 static void invalidate_dquots(struct super_block *sb, int type)
447 {
448         struct dquot *dquot, *tmp;
449
450 restart:
451         spin_lock(&dq_list_lock);
452         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
453                 if (dquot->dq_sb != sb)
454                         continue;
455                 if (dquot->dq_type != type)
456                         continue;
457                 /* Wait for dquot users */
458                 if (atomic_read(&dquot->dq_count)) {
459                         DEFINE_WAIT(wait);
460
461                         atomic_inc(&dquot->dq_count);
462                         prepare_to_wait(&dquot->dq_wait_unused, &wait,
463                                         TASK_UNINTERRUPTIBLE);
464                         spin_unlock(&dq_list_lock);
465                         /* Once dqput() wakes us up, we know it's time to free
466                          * the dquot.
467                          * IMPORTANT: we rely on the fact that there is always
468                          * at most one process waiting for dquot to free.
469                          * Otherwise dq_count would be > 1 and we would never
470                          * wake up.
471                          */
472                         if (atomic_read(&dquot->dq_count) > 1)
473                                 schedule();
474                         finish_wait(&dquot->dq_wait_unused, &wait);
475                         dqput(dquot);
476                         /* At this moment dquot() need not exist (it could be
477                          * reclaimed by prune_dqcache(). Hence we must
478                          * restart. */
479                         goto restart;
480                 }
481                 /*
482                  * Quota now has no users and it has been written on last
483                  * dqput()
484                  */
485                 remove_dquot_hash(dquot);
486                 remove_free_dquot(dquot);
487                 remove_inuse(dquot);
488                 do_destroy_dquot(dquot);
489         }
490         spin_unlock(&dq_list_lock);
491 }
492
493 /* Call callback for every active dquot on given filesystem */
494 int dquot_scan_active(struct super_block *sb,
495                       int (*fn)(struct dquot *dquot, unsigned long priv),
496                       unsigned long priv)
497 {
498         struct dquot *dquot, *old_dquot = NULL;
499         int ret = 0;
500
501         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
502         spin_lock(&dq_list_lock);
503         list_for_each_entry(dquot, &inuse_list, dq_inuse) {
504                 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
505                         continue;
506                 if (dquot->dq_sb != sb)
507                         continue;
508                 /* Now we have active dquot so we can just increase use count */
509                 atomic_inc(&dquot->dq_count);
510                 dqstats.lookups++;
511                 spin_unlock(&dq_list_lock);
512                 dqput(old_dquot);
513                 old_dquot = dquot;
514                 ret = fn(dquot, priv);
515                 if (ret < 0)
516                         goto out;
517                 spin_lock(&dq_list_lock);
518                 /* We are safe to continue now because our dquot could not
519                  * be moved out of the inuse list while we hold the reference */
520         }
521         spin_unlock(&dq_list_lock);
522 out:
523         dqput(old_dquot);
524         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
525         return ret;
526 }
527 EXPORT_SYMBOL(dquot_scan_active);
528
529 int vfs_quota_sync(struct super_block *sb, int type)
530 {
531         struct list_head *dirty;
532         struct dquot *dquot;
533         struct quota_info *dqopt = sb_dqopt(sb);
534         int cnt;
535
536         mutex_lock(&dqopt->dqonoff_mutex);
537         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
538                 if (type != -1 && cnt != type)
539                         continue;
540                 if (!sb_has_quota_active(sb, cnt))
541                         continue;
542                 spin_lock(&dq_list_lock);
543                 dirty = &dqopt->info[cnt].dqi_dirty_list;
544                 while (!list_empty(dirty)) {
545                         dquot = list_first_entry(dirty, struct dquot, dq_dirty);
546                         /* Dirty and inactive can be only bad dquot... */
547                         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
548                                 clear_dquot_dirty(dquot);
549                                 continue;
550                         }
551                         /* Now we have active dquot from which someone is
552                          * holding reference so we can safely just increase
553                          * use count */
554                         atomic_inc(&dquot->dq_count);
555                         dqstats.lookups++;
556                         spin_unlock(&dq_list_lock);
557                         sb->dq_op->write_dquot(dquot);
558                         dqput(dquot);
559                         spin_lock(&dq_list_lock);
560                 }
561                 spin_unlock(&dq_list_lock);
562         }
563
564         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
565                 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
566                     && info_dirty(&dqopt->info[cnt]))
567                         sb->dq_op->write_info(sb, cnt);
568         spin_lock(&dq_list_lock);
569         dqstats.syncs++;
570         spin_unlock(&dq_list_lock);
571         mutex_unlock(&dqopt->dqonoff_mutex);
572
573         return 0;
574 }
575 EXPORT_SYMBOL(vfs_quota_sync);
576
577 /* Free unused dquots from cache */
578 static void prune_dqcache(int count)
579 {
580         struct list_head *head;
581         struct dquot *dquot;
582
583         head = free_dquots.prev;
584         while (head != &free_dquots && count) {
585                 dquot = list_entry(head, struct dquot, dq_free);
586                 remove_dquot_hash(dquot);
587                 remove_free_dquot(dquot);
588                 remove_inuse(dquot);
589                 do_destroy_dquot(dquot);
590                 count--;
591                 head = free_dquots.prev;
592         }
593 }
594
595 /*
596  * This is called from kswapd when we think we need some
597  * more memory
598  */
599
600 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
601 {
602         if (nr) {
603                 spin_lock(&dq_list_lock);
604                 prune_dqcache(nr);
605                 spin_unlock(&dq_list_lock);
606         }
607         return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
608 }
609
610 static struct shrinker dqcache_shrinker = {
611         .shrink = shrink_dqcache_memory,
612         .seeks = DEFAULT_SEEKS,
613 };
614
615 /*
616  * Put reference to dquot
617  * NOTE: If you change this function please check whether dqput_blocks() works right...
618  */
619 void dqput(struct dquot *dquot)
620 {
621         int ret;
622
623         if (!dquot)
624                 return;
625 #ifdef __DQUOT_PARANOIA
626         if (!atomic_read(&dquot->dq_count)) {
627                 printk("VFS: dqput: trying to free free dquot\n");
628                 printk("VFS: device %s, dquot of %s %d\n",
629                         dquot->dq_sb->s_id,
630                         quotatypes[dquot->dq_type],
631                         dquot->dq_id);
632                 BUG();
633         }
634 #endif
635         
636         spin_lock(&dq_list_lock);
637         dqstats.drops++;
638         spin_unlock(&dq_list_lock);
639 we_slept:
640         spin_lock(&dq_list_lock);
641         if (atomic_read(&dquot->dq_count) > 1) {
642                 /* We have more than one user... nothing to do */
643                 atomic_dec(&dquot->dq_count);
644                 /* Releasing dquot during quotaoff phase? */
645                 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
646                     atomic_read(&dquot->dq_count) == 1)
647                         wake_up(&dquot->dq_wait_unused);
648                 spin_unlock(&dq_list_lock);
649                 return;
650         }
651         /* Need to release dquot? */
652         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
653                 spin_unlock(&dq_list_lock);
654                 /* Commit dquot before releasing */
655                 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
656                 if (ret < 0) {
657                         printk(KERN_ERR "VFS: cannot write quota structure on "
658                                 "device %s (error %d). Quota may get out of "
659                                 "sync!\n", dquot->dq_sb->s_id, ret);
660                         /*
661                          * We clear dirty bit anyway, so that we avoid
662                          * infinite loop here
663                          */
664                         spin_lock(&dq_list_lock);
665                         clear_dquot_dirty(dquot);
666                         spin_unlock(&dq_list_lock);
667                 }
668                 goto we_slept;
669         }
670         /* Clear flag in case dquot was inactive (something bad happened) */
671         clear_dquot_dirty(dquot);
672         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
673                 spin_unlock(&dq_list_lock);
674                 dquot->dq_sb->dq_op->release_dquot(dquot);
675                 goto we_slept;
676         }
677         atomic_dec(&dquot->dq_count);
678 #ifdef __DQUOT_PARANOIA
679         /* sanity check */
680         BUG_ON(!list_empty(&dquot->dq_free));
681 #endif
682         put_dquot_last(dquot);
683         spin_unlock(&dq_list_lock);
684 }
685 EXPORT_SYMBOL(dqput);
686
687 struct dquot *dquot_alloc(struct super_block *sb, int type)
688 {
689         return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
690 }
691 EXPORT_SYMBOL(dquot_alloc);
692
693 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
694 {
695         struct dquot *dquot;
696
697         dquot = sb->dq_op->alloc_dquot(sb, type);
698         if(!dquot)
699                 return NODQUOT;
700
701         mutex_init(&dquot->dq_lock);
702         INIT_LIST_HEAD(&dquot->dq_free);
703         INIT_LIST_HEAD(&dquot->dq_inuse);
704         INIT_HLIST_NODE(&dquot->dq_hash);
705         INIT_LIST_HEAD(&dquot->dq_dirty);
706         init_waitqueue_head(&dquot->dq_wait_unused);
707         dquot->dq_sb = sb;
708         dquot->dq_type = type;
709         atomic_set(&dquot->dq_count, 1);
710
711         return dquot;
712 }
713
714 /*
715  * Get reference to dquot
716  *
717  * Locking is slightly tricky here. We are guarded from parallel quotaoff()
718  * destroying our dquot by:
719  *   a) checking for quota flags under dq_list_lock and
720  *   b) getting a reference to dquot before we release dq_list_lock
721  */
722 struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
723 {
724         unsigned int hashent = hashfn(sb, id, type);
725         struct dquot *dquot = NODQUOT, *empty = NODQUOT;
726
727         if (!sb_has_quota_active(sb, type))
728                 return NODQUOT;
729 we_slept:
730         spin_lock(&dq_list_lock);
731         spin_lock(&dq_state_lock);
732         if (!sb_has_quota_active(sb, type)) {
733                 spin_unlock(&dq_state_lock);
734                 spin_unlock(&dq_list_lock);
735                 goto out;
736         }
737         spin_unlock(&dq_state_lock);
738
739         if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) {
740                 if (empty == NODQUOT) {
741                         spin_unlock(&dq_list_lock);
742                         if ((empty = get_empty_dquot(sb, type)) == NODQUOT)
743                                 schedule();     /* Try to wait for a moment... */
744                         goto we_slept;
745                 }
746                 dquot = empty;
747                 empty = NODQUOT;
748                 dquot->dq_id = id;
749                 /* all dquots go on the inuse_list */
750                 put_inuse(dquot);
751                 /* hash it first so it can be found */
752                 insert_dquot_hash(dquot);
753                 dqstats.lookups++;
754                 spin_unlock(&dq_list_lock);
755         } else {
756                 if (!atomic_read(&dquot->dq_count))
757                         remove_free_dquot(dquot);
758                 atomic_inc(&dquot->dq_count);
759                 dqstats.cache_hits++;
760                 dqstats.lookups++;
761                 spin_unlock(&dq_list_lock);
762         }
763         /* Wait for dq_lock - after this we know that either dquot_release() is already
764          * finished or it will be canceled due to dq_count > 1 test */
765         wait_on_dquot(dquot);
766         /* Read the dquot and instantiate it (everything done only if needed) */
767         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
768                 dqput(dquot);
769                 dquot = NODQUOT;
770                 goto out;
771         }
772 #ifdef __DQUOT_PARANOIA
773         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
774 #endif
775 out:
776         if (empty)
777                 do_destroy_dquot(empty);
778
779         return dquot;
780 }
781 EXPORT_SYMBOL(dqget);
782
783 static int dqinit_needed(struct inode *inode, int type)
784 {
785         int cnt;
786
787         if (IS_NOQUOTA(inode))
788                 return 0;
789         if (type != -1)
790                 return inode->i_dquot[type] == NODQUOT;
791         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
792                 if (inode->i_dquot[cnt] == NODQUOT)
793                         return 1;
794         return 0;
795 }
796
797 /* This routine is guarded by dqonoff_mutex mutex */
798 static void add_dquot_ref(struct super_block *sb, int type)
799 {
800         struct inode *inode, *old_inode = NULL;
801
802         spin_lock(&inode_lock);
803         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
804                 if (!atomic_read(&inode->i_writecount))
805                         continue;
806                 if (!dqinit_needed(inode, type))
807                         continue;
808                 if (inode->i_state & (I_FREEING|I_WILL_FREE))
809                         continue;
810
811                 __iget(inode);
812                 spin_unlock(&inode_lock);
813
814                 iput(old_inode);
815                 sb->dq_op->initialize(inode, type);
816                 /* We hold a reference to 'inode' so it couldn't have been
817                  * removed from s_inodes list while we dropped the inode_lock.
818                  * We cannot iput the inode now as we can be holding the last
819                  * reference and we cannot iput it under inode_lock. So we
820                  * keep the reference and iput it later. */
821                 old_inode = inode;
822                 spin_lock(&inode_lock);
823         }
824         spin_unlock(&inode_lock);
825         iput(old_inode);
826 }
827
828 /* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */
829 static inline int dqput_blocks(struct dquot *dquot)
830 {
831         if (atomic_read(&dquot->dq_count) <= 1)
832                 return 1;
833         return 0;
834 }
835
836 /* Remove references to dquots from inode - add dquot to list for freeing if needed */
837 /* We can't race with anybody because we hold dqptr_sem for writing... */
838 static int remove_inode_dquot_ref(struct inode *inode, int type,
839                                   struct list_head *tofree_head)
840 {
841         struct dquot *dquot = inode->i_dquot[type];
842
843         inode->i_dquot[type] = NODQUOT;
844         if (dquot != NODQUOT) {
845                 if (dqput_blocks(dquot)) {
846 #ifdef __DQUOT_PARANOIA
847                         if (atomic_read(&dquot->dq_count) != 1)
848                                 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
849 #endif
850                         spin_lock(&dq_list_lock);
851                         list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */
852                         spin_unlock(&dq_list_lock);
853                         return 1;
854                 }
855                 else
856                         dqput(dquot);   /* We have guaranteed we won't block */
857         }
858         return 0;
859 }
860
861 /* Free list of dquots - called from inode.c */
862 /* dquots are removed from inodes, no new references can be got so we are the only ones holding reference */
863 static void put_dquot_list(struct list_head *tofree_head)
864 {
865         struct list_head *act_head;
866         struct dquot *dquot;
867
868         act_head = tofree_head->next;
869         /* So now we have dquots on the list... Just free them */
870         while (act_head != tofree_head) {
871                 dquot = list_entry(act_head, struct dquot, dq_free);
872                 act_head = act_head->next;
873                 list_del_init(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */
874                 dqput(dquot);
875         }
876 }
877
878 static void remove_dquot_ref(struct super_block *sb, int type,
879                 struct list_head *tofree_head)
880 {
881         struct inode *inode;
882
883         spin_lock(&inode_lock);
884         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
885                 if (!IS_NOQUOTA(inode))
886                         remove_inode_dquot_ref(inode, type, tofree_head);
887         }
888         spin_unlock(&inode_lock);
889 }
890
891 /* Gather all references from inodes and drop them */
892 static void drop_dquot_ref(struct super_block *sb, int type)
893 {
894         LIST_HEAD(tofree_head);
895
896         if (sb->dq_op) {
897                 down_write(&sb_dqopt(sb)->dqptr_sem);
898                 remove_dquot_ref(sb, type, &tofree_head);
899                 up_write(&sb_dqopt(sb)->dqptr_sem);
900                 put_dquot_list(&tofree_head);
901         }
902 }
903
904 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
905 {
906         dquot->dq_dqb.dqb_curinodes += number;
907 }
908
909 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
910 {
911         dquot->dq_dqb.dqb_curspace += number;
912 }
913
914 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
915 {
916         dquot->dq_dqb.dqb_rsvspace += number;
917 }
918
919 /*
920  * Claim reserved quota space
921  */
922 static void dquot_claim_reserved_space(struct dquot *dquot,
923                                                 qsize_t number)
924 {
925         WARN_ON(dquot->dq_dqb.dqb_rsvspace < number);
926         dquot->dq_dqb.dqb_curspace += number;
927         dquot->dq_dqb.dqb_rsvspace -= number;
928 }
929
930 static inline
931 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
932 {
933         dquot->dq_dqb.dqb_rsvspace -= number;
934 }
935
936 static inline void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
937 {
938         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
939             dquot->dq_dqb.dqb_curinodes >= number)
940                 dquot->dq_dqb.dqb_curinodes -= number;
941         else
942                 dquot->dq_dqb.dqb_curinodes = 0;
943         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
944                 dquot->dq_dqb.dqb_itime = (time_t) 0;
945         clear_bit(DQ_INODES_B, &dquot->dq_flags);
946 }
947
948 static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
949 {
950         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
951             dquot->dq_dqb.dqb_curspace >= number)
952                 dquot->dq_dqb.dqb_curspace -= number;
953         else
954                 dquot->dq_dqb.dqb_curspace = 0;
955         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
956                 dquot->dq_dqb.dqb_btime = (time_t) 0;
957         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
958 }
959
960 static int warning_issued(struct dquot *dquot, const int warntype)
961 {
962         int flag = (warntype == QUOTA_NL_BHARDWARN ||
963                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
964                 ((warntype == QUOTA_NL_IHARDWARN ||
965                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
966
967         if (!flag)
968                 return 0;
969         return test_and_set_bit(flag, &dquot->dq_flags);
970 }
971
972 #ifdef CONFIG_PRINT_QUOTA_WARNING
973 static int flag_print_warnings = 1;
974
975 static inline int need_print_warning(struct dquot *dquot)
976 {
977         if (!flag_print_warnings)
978                 return 0;
979
980         switch (dquot->dq_type) {
981                 case USRQUOTA:
982                         return current_fsuid() == dquot->dq_id;
983                 case GRPQUOTA:
984                         return in_group_p(dquot->dq_id);
985         }
986         return 0;
987 }
988
989 /* Print warning to user which exceeded quota */
990 static void print_warning(struct dquot *dquot, const int warntype)
991 {
992         char *msg = NULL;
993         struct tty_struct *tty;
994
995         if (warntype == QUOTA_NL_IHARDBELOW ||
996             warntype == QUOTA_NL_ISOFTBELOW ||
997             warntype == QUOTA_NL_BHARDBELOW ||
998             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
999                 return;
1000
1001         tty = get_current_tty();
1002         if (!tty)
1003                 return;
1004         tty_write_message(tty, dquot->dq_sb->s_id);
1005         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1006                 tty_write_message(tty, ": warning, ");
1007         else
1008                 tty_write_message(tty, ": write failed, ");
1009         tty_write_message(tty, quotatypes[dquot->dq_type]);
1010         switch (warntype) {
1011                 case QUOTA_NL_IHARDWARN:
1012                         msg = " file limit reached.\r\n";
1013                         break;
1014                 case QUOTA_NL_ISOFTLONGWARN:
1015                         msg = " file quota exceeded too long.\r\n";
1016                         break;
1017                 case QUOTA_NL_ISOFTWARN:
1018                         msg = " file quota exceeded.\r\n";
1019                         break;
1020                 case QUOTA_NL_BHARDWARN:
1021                         msg = " block limit reached.\r\n";
1022                         break;
1023                 case QUOTA_NL_BSOFTLONGWARN:
1024                         msg = " block quota exceeded too long.\r\n";
1025                         break;
1026                 case QUOTA_NL_BSOFTWARN:
1027                         msg = " block quota exceeded.\r\n";
1028                         break;
1029         }
1030         tty_write_message(tty, msg);
1031         tty_kref_put(tty);
1032 }
1033 #endif
1034
1035 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1036
1037 /* Netlink family structure for quota */
1038 static struct genl_family quota_genl_family = {
1039         .id = GENL_ID_GENERATE,
1040         .hdrsize = 0,
1041         .name = "VFS_DQUOT",
1042         .version = 1,
1043         .maxattr = QUOTA_NL_A_MAX,
1044 };
1045
1046 /* Send warning to userspace about user which exceeded quota */
1047 static void send_warning(const struct dquot *dquot, const char warntype)
1048 {
1049         static atomic_t seq;
1050         struct sk_buff *skb;
1051         void *msg_head;
1052         int ret;
1053         int msg_size = 4 * nla_total_size(sizeof(u32)) +
1054                        2 * nla_total_size(sizeof(u64));
1055
1056         /* We have to allocate using GFP_NOFS as we are called from a
1057          * filesystem performing write and thus further recursion into
1058          * the fs to free some data could cause deadlocks. */
1059         skb = genlmsg_new(msg_size, GFP_NOFS);
1060         if (!skb) {
1061                 printk(KERN_ERR
1062                   "VFS: Not enough memory to send quota warning.\n");
1063                 return;
1064         }
1065         msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
1066                         &quota_genl_family, 0, QUOTA_NL_C_WARNING);
1067         if (!msg_head) {
1068                 printk(KERN_ERR
1069                   "VFS: Cannot store netlink header in quota warning.\n");
1070                 goto err_out;
1071         }
1072         ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type);
1073         if (ret)
1074                 goto attr_err_out;
1075         ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id);
1076         if (ret)
1077                 goto attr_err_out;
1078         ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
1079         if (ret)
1080                 goto attr_err_out;
1081         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR,
1082                 MAJOR(dquot->dq_sb->s_dev));
1083         if (ret)
1084                 goto attr_err_out;
1085         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR,
1086                 MINOR(dquot->dq_sb->s_dev));
1087         if (ret)
1088                 goto attr_err_out;
1089         ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
1090         if (ret)
1091                 goto attr_err_out;
1092         genlmsg_end(skb, msg_head);
1093
1094         ret = genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
1095         if (ret < 0 && ret != -ESRCH)
1096                 printk(KERN_ERR
1097                         "VFS: Failed to send notification message: %d\n", ret);
1098         return;
1099 attr_err_out:
1100         printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
1101 err_out:
1102         kfree_skb(skb);
1103 }
1104 #endif
1105 /*
1106  * Write warnings to the console and send warning messages over netlink.
1107  *
1108  * Note that this function can sleep.
1109  */
1110 static inline void flush_warnings(struct dquot * const *dquots, char *warntype)
1111 {
1112         int i;
1113
1114         for (i = 0; i < MAXQUOTAS; i++)
1115                 if (dquots[i] != NODQUOT && warntype[i] != QUOTA_NL_NOWARN &&
1116                     !warning_issued(dquots[i], warntype[i])) {
1117 #ifdef CONFIG_PRINT_QUOTA_WARNING
1118                         print_warning(dquots[i], warntype[i]);
1119 #endif
1120 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1121                         send_warning(dquots[i], warntype[i]);
1122 #endif
1123                 }
1124 }
1125
1126 static inline char ignore_hardlimit(struct dquot *dquot)
1127 {
1128         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1129
1130         return capable(CAP_SYS_RESOURCE) &&
1131             (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & V1_DQF_RSQUASH));
1132 }
1133
1134 /* needs dq_data_lock */
1135 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
1136 {
1137         *warntype = QUOTA_NL_NOWARN;
1138         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1139             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1140                 return QUOTA_OK;
1141
1142         if (dquot->dq_dqb.dqb_ihardlimit &&
1143            (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit &&
1144             !ignore_hardlimit(dquot)) {
1145                 *warntype = QUOTA_NL_IHARDWARN;
1146                 return NO_QUOTA;
1147         }
1148
1149         if (dquot->dq_dqb.dqb_isoftlimit &&
1150            (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
1151             dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime &&
1152             !ignore_hardlimit(dquot)) {
1153                 *warntype = QUOTA_NL_ISOFTLONGWARN;
1154                 return NO_QUOTA;
1155         }
1156
1157         if (dquot->dq_dqb.dqb_isoftlimit &&
1158            (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
1159             dquot->dq_dqb.dqb_itime == 0) {
1160                 *warntype = QUOTA_NL_ISOFTWARN;
1161                 dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1162         }
1163
1164         return QUOTA_OK;
1165 }
1166
1167 /* needs dq_data_lock */
1168 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1169 {
1170         qsize_t tspace;
1171
1172         *warntype = QUOTA_NL_NOWARN;
1173         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1174             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1175                 return QUOTA_OK;
1176
1177         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1178                 + space;
1179
1180         if (dquot->dq_dqb.dqb_bhardlimit &&
1181             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1182             !ignore_hardlimit(dquot)) {
1183                 if (!prealloc)
1184                         *warntype = QUOTA_NL_BHARDWARN;
1185                 return NO_QUOTA;
1186         }
1187
1188         if (dquot->dq_dqb.dqb_bsoftlimit &&
1189             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1190             dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime &&
1191             !ignore_hardlimit(dquot)) {
1192                 if (!prealloc)
1193                         *warntype = QUOTA_NL_BSOFTLONGWARN;
1194                 return NO_QUOTA;
1195         }
1196
1197         if (dquot->dq_dqb.dqb_bsoftlimit &&
1198             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1199             dquot->dq_dqb.dqb_btime == 0) {
1200                 if (!prealloc) {
1201                         *warntype = QUOTA_NL_BSOFTWARN;
1202                         dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
1203                 }
1204                 else
1205                         /*
1206                          * We don't allow preallocation to exceed softlimit so exceeding will
1207                          * be always printed
1208                          */
1209                         return NO_QUOTA;
1210         }
1211
1212         return QUOTA_OK;
1213 }
1214
1215 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1216 {
1217         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1218             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1219             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
1220                 return QUOTA_NL_NOWARN;
1221
1222         if (dquot->dq_dqb.dqb_curinodes - inodes <= dquot->dq_dqb.dqb_isoftlimit)
1223                 return QUOTA_NL_ISOFTBELOW;
1224         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1225             dquot->dq_dqb.dqb_curinodes - inodes < dquot->dq_dqb.dqb_ihardlimit)
1226                 return QUOTA_NL_IHARDBELOW;
1227         return QUOTA_NL_NOWARN;
1228 }
1229
1230 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1231 {
1232         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1233             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1234                 return QUOTA_NL_NOWARN;
1235
1236         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1237                 return QUOTA_NL_BSOFTBELOW;
1238         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1239             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1240                 return QUOTA_NL_BHARDBELOW;
1241         return QUOTA_NL_NOWARN;
1242 }
1243 /*
1244  *      Initialize quota pointers in inode
1245  *      We do things in a bit complicated way but by that we avoid calling
1246  *      dqget() and thus filesystem callbacks under dqptr_sem.
1247  */
1248 int dquot_initialize(struct inode *inode, int type)
1249 {
1250         unsigned int id = 0;
1251         int cnt, ret = 0;
1252         struct dquot *got[MAXQUOTAS] = { NODQUOT, NODQUOT };
1253         struct super_block *sb = inode->i_sb;
1254
1255         /* First test before acquiring mutex - solves deadlocks when we
1256          * re-enter the quota code and are already holding the mutex */
1257         if (IS_NOQUOTA(inode))
1258                 return 0;
1259
1260         /* First get references to structures we might need. */
1261         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1262                 if (type != -1 && cnt != type)
1263                         continue;
1264                 switch (cnt) {
1265                 case USRQUOTA:
1266                         id = inode->i_uid;
1267                         break;
1268                 case GRPQUOTA:
1269                         id = inode->i_gid;
1270                         break;
1271                 }
1272                 got[cnt] = dqget(sb, id, cnt);
1273         }
1274
1275         down_write(&sb_dqopt(sb)->dqptr_sem);
1276         /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
1277         if (IS_NOQUOTA(inode))
1278                 goto out_err;
1279         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1280                 if (type != -1 && cnt != type)
1281                         continue;
1282                 /* Avoid races with quotaoff() */
1283                 if (!sb_has_quota_active(sb, cnt))
1284                         continue;
1285                 if (inode->i_dquot[cnt] == NODQUOT) {
1286                         inode->i_dquot[cnt] = got[cnt];
1287                         got[cnt] = NODQUOT;
1288                 }
1289         }
1290 out_err:
1291         up_write(&sb_dqopt(sb)->dqptr_sem);
1292         /* Drop unused references */
1293         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1294                 dqput(got[cnt]);
1295         return ret;
1296 }
1297 EXPORT_SYMBOL(dquot_initialize);
1298
1299 /*
1300  *      Release all quotas referenced by inode
1301  */
1302 int dquot_drop(struct inode *inode)
1303 {
1304         int cnt;
1305         struct dquot *put[MAXQUOTAS];
1306
1307         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1308         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1309                 put[cnt] = inode->i_dquot[cnt];
1310                 inode->i_dquot[cnt] = NODQUOT;
1311         }
1312         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1313
1314         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1315                 dqput(put[cnt]);
1316         return 0;
1317 }
1318 EXPORT_SYMBOL(dquot_drop);
1319
1320 /* Wrapper to remove references to quota structures from inode */
1321 void vfs_dq_drop(struct inode *inode)
1322 {
1323         /* Here we can get arbitrary inode from clear_inode() so we have
1324          * to be careful. OTOH we don't need locking as quota operations
1325          * are allowed to change only at mount time */
1326         if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op
1327             && inode->i_sb->dq_op->drop) {
1328                 int cnt;
1329                 /* Test before calling to rule out calls from proc and such
1330                  * where we are not allowed to block. Note that this is
1331                  * actually reliable test even without the lock - the caller
1332                  * must assure that nobody can come after the DQUOT_DROP and
1333                  * add quota pointers back anyway */
1334                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1335                         if (inode->i_dquot[cnt] != NODQUOT)
1336                                 break;
1337                 if (cnt < MAXQUOTAS)
1338                         inode->i_sb->dq_op->drop(inode);
1339         }
1340 }
1341 EXPORT_SYMBOL(vfs_dq_drop);
1342
1343 /*
1344  * Following four functions update i_blocks+i_bytes fields and
1345  * quota information (together with appropriate checks)
1346  * NOTE: We absolutely rely on the fact that caller dirties
1347  * the inode (usually macros in quotaops.h care about this) and
1348  * holds a handle for the current transaction so that dquot write and
1349  * inode write go into the same transaction.
1350  */
1351
1352 /*
1353  * This operation can block, but only after everything is updated
1354  */
1355 int __dquot_alloc_space(struct inode *inode, qsize_t number,
1356                         int warn, int reserve)
1357 {
1358         int cnt, ret = QUOTA_OK;
1359         char warntype[MAXQUOTAS];
1360
1361         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1362                 warntype[cnt] = QUOTA_NL_NOWARN;
1363
1364         spin_lock(&dq_data_lock);
1365         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1366                 if (inode->i_dquot[cnt] == NODQUOT)
1367                         continue;
1368                 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt)
1369                     == NO_QUOTA) {
1370                         ret = NO_QUOTA;
1371                         goto out_unlock;
1372                 }
1373         }
1374         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1375                 if (inode->i_dquot[cnt] == NODQUOT)
1376                         continue;
1377                 if (reserve)
1378                         dquot_resv_space(inode->i_dquot[cnt], number);
1379                 else
1380                         dquot_incr_space(inode->i_dquot[cnt], number);
1381         }
1382         if (!reserve)
1383                 inode_add_bytes(inode, number);
1384 out_unlock:
1385         spin_unlock(&dq_data_lock);
1386         flush_warnings(inode->i_dquot, warntype);
1387         return ret;
1388 }
1389
1390 int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1391 {
1392         int cnt, ret = QUOTA_OK;
1393
1394         /*
1395          * First test before acquiring mutex - solves deadlocks when we
1396          * re-enter the quota code and are already holding the mutex
1397          */
1398         if (IS_NOQUOTA(inode)) {
1399                 inode_add_bytes(inode, number);
1400                 goto out;
1401         }
1402
1403         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1404         if (IS_NOQUOTA(inode)) {
1405                 inode_add_bytes(inode, number);
1406                 goto out_unlock;
1407         }
1408
1409         ret = __dquot_alloc_space(inode, number, warn, 0);
1410         if (ret == NO_QUOTA)
1411                 goto out_unlock;
1412
1413         /* Dirtify all the dquots - this can block when journalling */
1414         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1415                 if (inode->i_dquot[cnt])
1416                         mark_dquot_dirty(inode->i_dquot[cnt]);
1417 out_unlock:
1418         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1419 out:
1420         return ret;
1421 }
1422 EXPORT_SYMBOL(dquot_alloc_space);
1423
1424 int dquot_reserve_space(struct inode *inode, qsize_t number, int warn)
1425 {
1426         int ret = QUOTA_OK;
1427
1428         if (IS_NOQUOTA(inode))
1429                 goto out;
1430
1431         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1432         if (IS_NOQUOTA(inode))
1433                 goto out_unlock;
1434
1435         ret = __dquot_alloc_space(inode, number, warn, 1);
1436 out_unlock:
1437         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1438 out:
1439         return ret;
1440 }
1441 EXPORT_SYMBOL(dquot_reserve_space);
1442
1443 /*
1444  * This operation can block, but only after everything is updated
1445  */
1446 int dquot_alloc_inode(const struct inode *inode, qsize_t number)
1447 {
1448         int cnt, ret = NO_QUOTA;
1449         char warntype[MAXQUOTAS];
1450
1451         /* First test before acquiring mutex - solves deadlocks when we
1452          * re-enter the quota code and are already holding the mutex */
1453         if (IS_NOQUOTA(inode))
1454                 return QUOTA_OK;
1455         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1456                 warntype[cnt] = QUOTA_NL_NOWARN;
1457         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1458         if (IS_NOQUOTA(inode)) {
1459                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1460                 return QUOTA_OK;
1461         }
1462         spin_lock(&dq_data_lock);
1463         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1464                 if (inode->i_dquot[cnt] == NODQUOT)
1465                         continue;
1466                 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA)
1467                         goto warn_put_all;
1468         }
1469
1470         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1471                 if (inode->i_dquot[cnt] == NODQUOT)
1472                         continue;
1473                 dquot_incr_inodes(inode->i_dquot[cnt], number);
1474         }
1475         ret = QUOTA_OK;
1476 warn_put_all:
1477         spin_unlock(&dq_data_lock);
1478         if (ret == QUOTA_OK)
1479                 /* Dirtify all the dquots - this can block when journalling */
1480                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1481                         if (inode->i_dquot[cnt])
1482                                 mark_dquot_dirty(inode->i_dquot[cnt]);
1483         flush_warnings(inode->i_dquot, warntype);
1484         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1485         return ret;
1486 }
1487 EXPORT_SYMBOL(dquot_alloc_inode);
1488
1489 int dquot_claim_space(struct inode *inode, qsize_t number)
1490 {
1491         int cnt;
1492         int ret = QUOTA_OK;
1493
1494         if (IS_NOQUOTA(inode)) {
1495                 inode_add_bytes(inode, number);
1496                 goto out;
1497         }
1498
1499         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1500         if (IS_NOQUOTA(inode))  {
1501                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1502                 inode_add_bytes(inode, number);
1503                 goto out;
1504         }
1505
1506         spin_lock(&dq_data_lock);
1507         /* Claim reserved quotas to allocated quotas */
1508         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1509                 if (inode->i_dquot[cnt] != NODQUOT)
1510                         dquot_claim_reserved_space(inode->i_dquot[cnt],
1511                                                         number);
1512         }
1513         /* Update inode bytes */
1514         inode_add_bytes(inode, number);
1515         spin_unlock(&dq_data_lock);
1516         /* Dirtify all the dquots - this can block when journalling */
1517         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1518                 if (inode->i_dquot[cnt])
1519                         mark_dquot_dirty(inode->i_dquot[cnt]);
1520         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1521 out:
1522         return ret;
1523 }
1524 EXPORT_SYMBOL(dquot_claim_space);
1525
1526 /*
1527  * Release reserved quota space
1528  */
1529 void dquot_release_reserved_space(struct inode *inode, qsize_t number)
1530 {
1531         int cnt;
1532
1533         if (IS_NOQUOTA(inode))
1534                 goto out;
1535
1536         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1537         if (IS_NOQUOTA(inode))
1538                 goto out_unlock;
1539
1540         spin_lock(&dq_data_lock);
1541         /* Release reserved dquots */
1542         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1543                 if (inode->i_dquot[cnt] != NODQUOT)
1544                         dquot_free_reserved_space(inode->i_dquot[cnt], number);
1545         }
1546         spin_unlock(&dq_data_lock);
1547
1548 out_unlock:
1549         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1550 out:
1551         return;
1552 }
1553 EXPORT_SYMBOL(dquot_release_reserved_space);
1554
1555 /*
1556  * This operation can block, but only after everything is updated
1557  */
1558 int dquot_free_space(struct inode *inode, qsize_t number)
1559 {
1560         unsigned int cnt;
1561         char warntype[MAXQUOTAS];
1562
1563         /* First test before acquiring mutex - solves deadlocks when we
1564          * re-enter the quota code and are already holding the mutex */
1565         if (IS_NOQUOTA(inode)) {
1566 out_sub:
1567                 inode_sub_bytes(inode, number);
1568                 return QUOTA_OK;
1569         }
1570
1571         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1572         /* Now recheck reliably when holding dqptr_sem */
1573         if (IS_NOQUOTA(inode)) {
1574                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1575                 goto out_sub;
1576         }
1577         spin_lock(&dq_data_lock);
1578         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1579                 if (inode->i_dquot[cnt] == NODQUOT)
1580                         continue;
1581                 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
1582                 dquot_decr_space(inode->i_dquot[cnt], number);
1583         }
1584         inode_sub_bytes(inode, number);
1585         spin_unlock(&dq_data_lock);
1586         /* Dirtify all the dquots - this can block when journalling */
1587         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1588                 if (inode->i_dquot[cnt])
1589                         mark_dquot_dirty(inode->i_dquot[cnt]);
1590         flush_warnings(inode->i_dquot, warntype);
1591         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1592         return QUOTA_OK;
1593 }
1594 EXPORT_SYMBOL(dquot_free_space);
1595
1596 /*
1597  * This operation can block, but only after everything is updated
1598  */
1599 int dquot_free_inode(const struct inode *inode, qsize_t number)
1600 {
1601         unsigned int cnt;
1602         char warntype[MAXQUOTAS];
1603
1604         /* First test before acquiring mutex - solves deadlocks when we
1605          * re-enter the quota code and are already holding the mutex */
1606         if (IS_NOQUOTA(inode))
1607                 return QUOTA_OK;
1608
1609         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1610         /* Now recheck reliably when holding dqptr_sem */
1611         if (IS_NOQUOTA(inode)) {
1612                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1613                 return QUOTA_OK;
1614         }
1615         spin_lock(&dq_data_lock);
1616         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1617                 if (inode->i_dquot[cnt] == NODQUOT)
1618                         continue;
1619                 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], number);
1620                 dquot_decr_inodes(inode->i_dquot[cnt], number);
1621         }
1622         spin_unlock(&dq_data_lock);
1623         /* Dirtify all the dquots - this can block when journalling */
1624         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1625                 if (inode->i_dquot[cnt])
1626                         mark_dquot_dirty(inode->i_dquot[cnt]);
1627         flush_warnings(inode->i_dquot, warntype);
1628         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1629         return QUOTA_OK;
1630 }
1631 EXPORT_SYMBOL(dquot_free_inode);
1632
1633 /*
1634  * call back function, get reserved quota space from underlying fs
1635  */
1636 qsize_t dquot_get_reserved_space(struct inode *inode)
1637 {
1638         qsize_t reserved_space = 0;
1639
1640         if (sb_any_quota_active(inode->i_sb) &&
1641             inode->i_sb->dq_op->get_reserved_space)
1642                 reserved_space = inode->i_sb->dq_op->get_reserved_space(inode);
1643         return reserved_space;
1644 }
1645
1646 /*
1647  * Transfer the number of inode and blocks from one diskquota to an other.
1648  *
1649  * This operation can block, but only after everything is updated
1650  * A transaction must be started when entering this function.
1651  */
1652 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1653 {
1654         qsize_t space, cur_space;
1655         qsize_t rsv_space = 0;
1656         struct dquot *transfer_from[MAXQUOTAS];
1657         struct dquot *transfer_to[MAXQUOTAS];
1658         int cnt, ret = QUOTA_OK;
1659         int chuid = iattr->ia_valid & ATTR_UID && inode->i_uid != iattr->ia_uid,
1660             chgid = iattr->ia_valid & ATTR_GID && inode->i_gid != iattr->ia_gid;
1661         char warntype_to[MAXQUOTAS];
1662         char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
1663
1664         /* First test before acquiring mutex - solves deadlocks when we
1665          * re-enter the quota code and are already holding the mutex */
1666         if (IS_NOQUOTA(inode))
1667                 return QUOTA_OK;
1668         /* Initialize the arrays */
1669         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1670                 transfer_from[cnt] = NODQUOT;
1671                 transfer_to[cnt] = NODQUOT;
1672                 warntype_to[cnt] = QUOTA_NL_NOWARN;
1673                 switch (cnt) {
1674                         case USRQUOTA:
1675                                 if (!chuid)
1676                                         continue;
1677                                 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt);
1678                                 break;
1679                         case GRPQUOTA:
1680                                 if (!chgid)
1681                                         continue;
1682                                 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt);
1683                                 break;
1684                 }
1685         }
1686
1687         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1688         /* Now recheck reliably when holding dqptr_sem */
1689         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1690                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1691                 goto put_all;
1692         }
1693         spin_lock(&dq_data_lock);
1694         cur_space = inode_get_bytes(inode);
1695         rsv_space = dquot_get_reserved_space(inode);
1696         space = cur_space + rsv_space;
1697         /* Build the transfer_from list and check the limits */
1698         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1699                 if (transfer_to[cnt] == NODQUOT)
1700                         continue;
1701                 transfer_from[cnt] = inode->i_dquot[cnt];
1702                 if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) ==
1703                     NO_QUOTA || check_bdq(transfer_to[cnt], space, 0,
1704                     warntype_to + cnt) == NO_QUOTA)
1705                         goto over_quota;
1706         }
1707
1708         /*
1709          * Finally perform the needed transfer from transfer_from to transfer_to
1710          */
1711         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1712                 /*
1713                  * Skip changes for same uid or gid or for turned off quota-type.
1714                  */
1715                 if (transfer_to[cnt] == NODQUOT)
1716                         continue;
1717
1718                 /* Due to IO error we might not have transfer_from[] structure */
1719                 if (transfer_from[cnt]) {
1720                         warntype_from_inodes[cnt] =
1721                                 info_idq_free(transfer_from[cnt], 1);
1722                         warntype_from_space[cnt] =
1723                                 info_bdq_free(transfer_from[cnt], space);
1724                         dquot_decr_inodes(transfer_from[cnt], 1);
1725                         dquot_decr_space(transfer_from[cnt], cur_space);
1726                         dquot_free_reserved_space(transfer_from[cnt],
1727                                                   rsv_space);
1728                 }
1729
1730                 dquot_incr_inodes(transfer_to[cnt], 1);
1731                 dquot_incr_space(transfer_to[cnt], cur_space);
1732                 dquot_resv_space(transfer_to[cnt], rsv_space);
1733
1734                 inode->i_dquot[cnt] = transfer_to[cnt];
1735         }
1736         spin_unlock(&dq_data_lock);
1737         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1738
1739         /* Dirtify all the dquots - this can block when journalling */
1740         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1741                 if (transfer_from[cnt])
1742                         mark_dquot_dirty(transfer_from[cnt]);
1743                 if (transfer_to[cnt]) {
1744                         mark_dquot_dirty(transfer_to[cnt]);
1745                         /* The reference we got is transferred to the inode */
1746                         transfer_to[cnt] = NODQUOT;
1747                 }
1748         }
1749 warn_put_all:
1750         flush_warnings(transfer_to, warntype_to);
1751         flush_warnings(transfer_from, warntype_from_inodes);
1752         flush_warnings(transfer_from, warntype_from_space);
1753 put_all:
1754         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1755                 dqput(transfer_from[cnt]);
1756                 dqput(transfer_to[cnt]);
1757         }
1758         return ret;
1759 over_quota:
1760         spin_unlock(&dq_data_lock);
1761         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1762         /* Clear dquot pointers we don't want to dqput() */
1763         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1764                 transfer_from[cnt] = NODQUOT;
1765         ret = NO_QUOTA;
1766         goto warn_put_all;
1767 }
1768 EXPORT_SYMBOL(dquot_transfer);
1769
1770 /* Wrapper for transferring ownership of an inode */
1771 int vfs_dq_transfer(struct inode *inode, struct iattr *iattr)
1772 {
1773         if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) {
1774                 vfs_dq_init(inode);
1775                 if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA)
1776                         return 1;
1777         }
1778         return 0;
1779 }
1780 EXPORT_SYMBOL(vfs_dq_transfer);
1781
1782 /*
1783  * Write info of quota file to disk
1784  */
1785 int dquot_commit_info(struct super_block *sb, int type)
1786 {
1787         int ret;
1788         struct quota_info *dqopt = sb_dqopt(sb);
1789
1790         mutex_lock(&dqopt->dqio_mutex);
1791         ret = dqopt->ops[type]->write_file_info(sb, type);
1792         mutex_unlock(&dqopt->dqio_mutex);
1793         return ret;
1794 }
1795 EXPORT_SYMBOL(dquot_commit_info);
1796
1797 /*
1798  * Definitions of diskquota operations.
1799  */
1800 struct dquot_operations dquot_operations = {
1801         .initialize     = dquot_initialize,
1802         .drop           = dquot_drop,
1803         .alloc_space    = dquot_alloc_space,
1804         .alloc_inode    = dquot_alloc_inode,
1805         .free_space     = dquot_free_space,
1806         .free_inode     = dquot_free_inode,
1807         .transfer       = dquot_transfer,
1808         .write_dquot    = dquot_commit,
1809         .acquire_dquot  = dquot_acquire,
1810         .release_dquot  = dquot_release,
1811         .mark_dirty     = dquot_mark_dquot_dirty,
1812         .write_info     = dquot_commit_info,
1813         .alloc_dquot    = dquot_alloc,
1814         .destroy_dquot  = dquot_destroy,
1815 };
1816
1817 /*
1818  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1819  */
1820 int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags)
1821 {
1822         int cnt, ret = 0;
1823         struct quota_info *dqopt = sb_dqopt(sb);
1824         struct inode *toputinode[MAXQUOTAS];
1825
1826         /* Cannot turn off usage accounting without turning off limits, or
1827          * suspend quotas and simultaneously turn quotas off. */
1828         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1829             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1830             DQUOT_USAGE_ENABLED)))
1831                 return -EINVAL;
1832
1833         /* We need to serialize quota_off() for device */
1834         mutex_lock(&dqopt->dqonoff_mutex);
1835
1836         /*
1837          * Skip everything if there's nothing to do. We have to do this because
1838          * sometimes we are called when fill_super() failed and calling
1839          * sync_fs() in such cases does no good.
1840          */
1841         if (!sb_any_quota_loaded(sb)) {
1842                 mutex_unlock(&dqopt->dqonoff_mutex);
1843                 return 0;
1844         }
1845         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1846                 toputinode[cnt] = NULL;
1847                 if (type != -1 && cnt != type)
1848                         continue;
1849                 if (!sb_has_quota_loaded(sb, cnt))
1850                         continue;
1851
1852                 if (flags & DQUOT_SUSPENDED) {
1853                         spin_lock(&dq_state_lock);
1854                         dqopt->flags |=
1855                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1856                         spin_unlock(&dq_state_lock);
1857                 } else {
1858                         spin_lock(&dq_state_lock);
1859                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
1860                         /* Turning off suspended quotas? */
1861                         if (!sb_has_quota_loaded(sb, cnt) &&
1862                             sb_has_quota_suspended(sb, cnt)) {
1863                                 dqopt->flags &= ~dquot_state_flag(
1864                                                         DQUOT_SUSPENDED, cnt);
1865                                 spin_unlock(&dq_state_lock);
1866                                 iput(dqopt->files[cnt]);
1867                                 dqopt->files[cnt] = NULL;
1868                                 continue;
1869                         }
1870                         spin_unlock(&dq_state_lock);
1871                 }
1872
1873                 /* We still have to keep quota loaded? */
1874                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
1875                         continue;
1876
1877                 /* Note: these are blocking operations */
1878                 drop_dquot_ref(sb, cnt);
1879                 invalidate_dquots(sb, cnt);
1880                 /*
1881                  * Now all dquots should be invalidated, all writes done so we should be only
1882                  * users of the info. No locks needed.
1883                  */
1884                 if (info_dirty(&dqopt->info[cnt]))
1885                         sb->dq_op->write_info(sb, cnt);
1886                 if (dqopt->ops[cnt]->free_file_info)
1887                         dqopt->ops[cnt]->free_file_info(sb, cnt);
1888                 put_quota_format(dqopt->info[cnt].dqi_format);
1889
1890                 toputinode[cnt] = dqopt->files[cnt];
1891                 if (!sb_has_quota_loaded(sb, cnt))
1892                         dqopt->files[cnt] = NULL;
1893                 dqopt->info[cnt].dqi_flags = 0;
1894                 dqopt->info[cnt].dqi_igrace = 0;
1895                 dqopt->info[cnt].dqi_bgrace = 0;
1896                 dqopt->ops[cnt] = NULL;
1897         }
1898         mutex_unlock(&dqopt->dqonoff_mutex);
1899
1900         /* Skip syncing and setting flags if quota files are hidden */
1901         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
1902                 goto put_inodes;
1903
1904         /* Sync the superblock so that buffers with quota data are written to
1905          * disk (and so userspace sees correct data afterwards). */
1906         if (sb->s_op->sync_fs)
1907                 sb->s_op->sync_fs(sb, 1);
1908         sync_blockdev(sb->s_bdev);
1909         /* Now the quota files are just ordinary files and we can set the
1910          * inode flags back. Moreover we discard the pagecache so that
1911          * userspace sees the writes we did bypassing the pagecache. We
1912          * must also discard the blockdev buffers so that we see the
1913          * changes done by userspace on the next quotaon() */
1914         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1915                 if (toputinode[cnt]) {
1916                         mutex_lock(&dqopt->dqonoff_mutex);
1917                         /* If quota was reenabled in the meantime, we have
1918                          * nothing to do */
1919                         if (!sb_has_quota_loaded(sb, cnt)) {
1920                                 mutex_lock_nested(&toputinode[cnt]->i_mutex, I_MUTEX_QUOTA);
1921                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1922                                   S_NOATIME | S_NOQUOTA);
1923                                 truncate_inode_pages(&toputinode[cnt]->i_data, 0);
1924                                 mutex_unlock(&toputinode[cnt]->i_mutex);
1925                                 mark_inode_dirty(toputinode[cnt]);
1926                         }
1927                         mutex_unlock(&dqopt->dqonoff_mutex);
1928                 }
1929         if (sb->s_bdev)
1930                 invalidate_bdev(sb->s_bdev);
1931 put_inodes:
1932         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1933                 if (toputinode[cnt]) {
1934                         /* On remount RO, we keep the inode pointer so that we
1935                          * can reenable quota on the subsequent remount RW. We
1936                          * have to check 'flags' variable and not use sb_has_
1937                          * function because another quotaon / quotaoff could
1938                          * change global state before we got here. We refuse
1939                          * to suspend quotas when there is pending delete on
1940                          * the quota file... */
1941                         if (!(flags & DQUOT_SUSPENDED))
1942                                 iput(toputinode[cnt]);
1943                         else if (!toputinode[cnt]->i_nlink)
1944                                 ret = -EBUSY;
1945                 }
1946         return ret;
1947 }
1948 EXPORT_SYMBOL(vfs_quota_disable);
1949
1950 int vfs_quota_off(struct super_block *sb, int type, int remount)
1951 {
1952         return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED :
1953                                  (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED));
1954 }
1955 EXPORT_SYMBOL(vfs_quota_off);
1956 /*
1957  *      Turn quotas on on a device
1958  */
1959
1960 /*
1961  * Helper function to turn quotas on when we already have the inode of
1962  * quota file and no quota information is loaded.
1963  */
1964 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
1965         unsigned int flags)
1966 {
1967         struct quota_format_type *fmt = find_quota_format(format_id);
1968         struct super_block *sb = inode->i_sb;
1969         struct quota_info *dqopt = sb_dqopt(sb);
1970         int error;
1971         int oldflags = -1;
1972
1973         if (!fmt)
1974                 return -ESRCH;
1975         if (!S_ISREG(inode->i_mode)) {
1976                 error = -EACCES;
1977                 goto out_fmt;
1978         }
1979         if (IS_RDONLY(inode)) {
1980                 error = -EROFS;
1981                 goto out_fmt;
1982         }
1983         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
1984                 error = -EINVAL;
1985                 goto out_fmt;
1986         }
1987         /* Usage always has to be set... */
1988         if (!(flags & DQUOT_USAGE_ENABLED)) {
1989                 error = -EINVAL;
1990                 goto out_fmt;
1991         }
1992
1993         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
1994                 /* As we bypass the pagecache we must now flush the inode so
1995                  * that we see all the changes from userspace... */
1996                 write_inode_now(inode, 1);
1997                 /* And now flush the block cache so that kernel sees the
1998                  * changes */
1999                 invalidate_bdev(sb->s_bdev);
2000         }
2001         mutex_lock(&inode->i_mutex);
2002         mutex_lock(&dqopt->dqonoff_mutex);
2003         if (sb_has_quota_loaded(sb, type)) {
2004                 error = -EBUSY;
2005                 goto out_lock;
2006         }
2007
2008         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2009                 /* We don't want quota and atime on quota files (deadlocks
2010                  * possible) Also nobody should write to the file - we use
2011                  * special IO operations which ignore the immutable bit. */
2012                 down_write(&dqopt->dqptr_sem);
2013                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA);
2014                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2015                 up_write(&dqopt->dqptr_sem);
2016                 sb->dq_op->drop(inode);
2017         }
2018
2019         error = -EIO;
2020         dqopt->files[type] = igrab(inode);
2021         if (!dqopt->files[type])
2022                 goto out_lock;
2023         error = -EINVAL;
2024         if (!fmt->qf_ops->check_quota_file(sb, type))
2025                 goto out_file_init;
2026
2027         dqopt->ops[type] = fmt->qf_ops;
2028         dqopt->info[type].dqi_format = fmt;
2029         dqopt->info[type].dqi_fmt_id = format_id;
2030         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2031         mutex_lock(&dqopt->dqio_mutex);
2032         if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) {
2033                 mutex_unlock(&dqopt->dqio_mutex);
2034                 goto out_file_init;
2035         }
2036         mutex_unlock(&dqopt->dqio_mutex);
2037         mutex_unlock(&inode->i_mutex);
2038         spin_lock(&dq_state_lock);
2039         dqopt->flags |= dquot_state_flag(flags, type);
2040         spin_unlock(&dq_state_lock);
2041
2042         add_dquot_ref(sb, type);
2043         mutex_unlock(&dqopt->dqonoff_mutex);
2044
2045         return 0;
2046
2047 out_file_init:
2048         dqopt->files[type] = NULL;
2049         iput(inode);
2050 out_lock:
2051         mutex_unlock(&dqopt->dqonoff_mutex);
2052         if (oldflags != -1) {
2053                 down_write(&dqopt->dqptr_sem);
2054                 /* Set the flags back (in the case of accidental quotaon()
2055                  * on a wrong file we don't want to mess up the flags) */
2056                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2057                 inode->i_flags |= oldflags;
2058                 up_write(&dqopt->dqptr_sem);
2059         }
2060         mutex_unlock(&inode->i_mutex);
2061 out_fmt:
2062         put_quota_format(fmt);
2063
2064         return error; 
2065 }
2066
2067 /* Reenable quotas on remount RW */
2068 static int vfs_quota_on_remount(struct super_block *sb, int type)
2069 {
2070         struct quota_info *dqopt = sb_dqopt(sb);
2071         struct inode *inode;
2072         int ret;
2073         unsigned int flags;
2074
2075         mutex_lock(&dqopt->dqonoff_mutex);
2076         if (!sb_has_quota_suspended(sb, type)) {
2077                 mutex_unlock(&dqopt->dqonoff_mutex);
2078                 return 0;
2079         }
2080         inode = dqopt->files[type];
2081         dqopt->files[type] = NULL;
2082         spin_lock(&dq_state_lock);
2083         flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2084                                                 DQUOT_LIMITS_ENABLED, type);
2085         dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type);
2086         spin_unlock(&dq_state_lock);
2087         mutex_unlock(&dqopt->dqonoff_mutex);
2088
2089         flags = dquot_generic_flag(flags, type);
2090         ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id,
2091                                    flags);
2092         iput(inode);
2093
2094         return ret;
2095 }
2096
2097 int vfs_quota_on_path(struct super_block *sb, int type, int format_id,
2098                       struct path *path)
2099 {
2100         int error = security_quota_on(path->dentry);
2101         if (error)
2102                 return error;
2103         /* Quota file not on the same filesystem? */
2104         if (path->mnt->mnt_sb != sb)
2105                 error = -EXDEV;
2106         else
2107                 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2108                                              format_id, DQUOT_USAGE_ENABLED |
2109                                              DQUOT_LIMITS_ENABLED);
2110         return error;
2111 }
2112 EXPORT_SYMBOL(vfs_quota_on_path);
2113
2114 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name,
2115                  int remount)
2116 {
2117         struct path path;
2118         int error;
2119
2120         if (remount)
2121                 return vfs_quota_on_remount(sb, type);
2122
2123         error = kern_path(name, LOOKUP_FOLLOW, &path);
2124         if (!error) {
2125                 error = vfs_quota_on_path(sb, type, format_id, &path);
2126                 path_put(&path);
2127         }
2128         return error;
2129 }
2130 EXPORT_SYMBOL(vfs_quota_on);
2131
2132 /*
2133  * More powerful function for turning on quotas allowing setting
2134  * of individual quota flags
2135  */
2136 int vfs_quota_enable(struct inode *inode, int type, int format_id,
2137                 unsigned int flags)
2138 {
2139         int ret = 0;
2140         struct super_block *sb = inode->i_sb;
2141         struct quota_info *dqopt = sb_dqopt(sb);
2142
2143         /* Just unsuspend quotas? */
2144         if (flags & DQUOT_SUSPENDED)
2145                 return vfs_quota_on_remount(sb, type);
2146         if (!flags)
2147                 return 0;
2148         /* Just updating flags needed? */
2149         if (sb_has_quota_loaded(sb, type)) {
2150                 mutex_lock(&dqopt->dqonoff_mutex);
2151                 /* Now do a reliable test... */
2152                 if (!sb_has_quota_loaded(sb, type)) {
2153                         mutex_unlock(&dqopt->dqonoff_mutex);
2154                         goto load_quota;
2155                 }
2156                 if (flags & DQUOT_USAGE_ENABLED &&
2157                     sb_has_quota_usage_enabled(sb, type)) {
2158                         ret = -EBUSY;
2159                         goto out_lock;
2160                 }
2161                 if (flags & DQUOT_LIMITS_ENABLED &&
2162                     sb_has_quota_limits_enabled(sb, type)) {
2163                         ret = -EBUSY;
2164                         goto out_lock;
2165                 }
2166                 spin_lock(&dq_state_lock);
2167                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2168                 spin_unlock(&dq_state_lock);
2169 out_lock:
2170                 mutex_unlock(&dqopt->dqonoff_mutex);
2171                 return ret;
2172         }
2173
2174 load_quota:
2175         return vfs_load_quota_inode(inode, type, format_id, flags);
2176 }
2177 EXPORT_SYMBOL(vfs_quota_enable);
2178
2179 /*
2180  * This function is used when filesystem needs to initialize quotas
2181  * during mount time.
2182  */
2183 int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
2184                 int format_id, int type)
2185 {
2186         struct dentry *dentry;
2187         int error;
2188
2189         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2190         if (IS_ERR(dentry))
2191                 return PTR_ERR(dentry);
2192
2193         if (!dentry->d_inode) {
2194                 error = -ENOENT;
2195                 goto out;
2196         }
2197
2198         error = security_quota_on(dentry);
2199         if (!error)
2200                 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2201                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2202
2203 out:
2204         dput(dentry);
2205         return error;
2206 }
2207 EXPORT_SYMBOL(vfs_quota_on_mount);
2208
2209 /* Wrapper to turn on quotas when remounting rw */
2210 int vfs_dq_quota_on_remount(struct super_block *sb)
2211 {
2212         int cnt;
2213         int ret = 0, err;
2214
2215         if (!sb->s_qcop || !sb->s_qcop->quota_on)
2216                 return -ENOSYS;
2217         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2218                 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1);
2219                 if (err < 0 && !ret)
2220                         ret = err;
2221         }
2222         return ret;
2223 }
2224 EXPORT_SYMBOL(vfs_dq_quota_on_remount);
2225
2226 static inline qsize_t qbtos(qsize_t blocks)
2227 {
2228         return blocks << QIF_DQBLKSIZE_BITS;
2229 }
2230
2231 static inline qsize_t stoqb(qsize_t space)
2232 {
2233         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2234 }
2235
2236 /* Generic routine for getting common part of quota structure */
2237 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
2238 {
2239         struct mem_dqblk *dm = &dquot->dq_dqb;
2240
2241         spin_lock(&dq_data_lock);
2242         di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit);
2243         di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit);
2244         di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace;
2245         di->dqb_ihardlimit = dm->dqb_ihardlimit;
2246         di->dqb_isoftlimit = dm->dqb_isoftlimit;
2247         di->dqb_curinodes = dm->dqb_curinodes;
2248         di->dqb_btime = dm->dqb_btime;
2249         di->dqb_itime = dm->dqb_itime;
2250         di->dqb_valid = QIF_ALL;
2251         spin_unlock(&dq_data_lock);
2252 }
2253
2254 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
2255 {
2256         struct dquot *dquot;
2257
2258         dquot = dqget(sb, id, type);
2259         if (dquot == NODQUOT)
2260                 return -ESRCH;
2261         do_get_dqblk(dquot, di);
2262         dqput(dquot);
2263
2264         return 0;
2265 }
2266 EXPORT_SYMBOL(vfs_get_dqblk);
2267
2268 /* Generic routine for setting common part of quota structure */
2269 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
2270 {
2271         struct mem_dqblk *dm = &dquot->dq_dqb;
2272         int check_blim = 0, check_ilim = 0;
2273         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2274
2275         if ((di->dqb_valid & QIF_BLIMITS &&
2276              (di->dqb_bhardlimit > dqi->dqi_maxblimit ||
2277               di->dqb_bsoftlimit > dqi->dqi_maxblimit)) ||
2278             (di->dqb_valid & QIF_ILIMITS &&
2279              (di->dqb_ihardlimit > dqi->dqi_maxilimit ||
2280               di->dqb_isoftlimit > dqi->dqi_maxilimit)))
2281                 return -ERANGE;
2282
2283         spin_lock(&dq_data_lock);
2284         if (di->dqb_valid & QIF_SPACE) {
2285                 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace;
2286                 check_blim = 1;
2287                 __set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2288         }
2289         if (di->dqb_valid & QIF_BLIMITS) {
2290                 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit);
2291                 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit);
2292                 check_blim = 1;
2293                 __set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2294         }
2295         if (di->dqb_valid & QIF_INODES) {
2296                 dm->dqb_curinodes = di->dqb_curinodes;
2297                 check_ilim = 1;
2298                 __set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2299         }
2300         if (di->dqb_valid & QIF_ILIMITS) {
2301                 dm->dqb_isoftlimit = di->dqb_isoftlimit;
2302                 dm->dqb_ihardlimit = di->dqb_ihardlimit;
2303                 check_ilim = 1;
2304                 __set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2305         }
2306         if (di->dqb_valid & QIF_BTIME) {
2307                 dm->dqb_btime = di->dqb_btime;
2308                 check_blim = 1;
2309                 __set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2310         }
2311         if (di->dqb_valid & QIF_ITIME) {
2312                 dm->dqb_itime = di->dqb_itime;
2313                 check_ilim = 1;
2314                 __set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2315         }
2316
2317         if (check_blim) {
2318                 if (!dm->dqb_bsoftlimit || dm->dqb_curspace < dm->dqb_bsoftlimit) {
2319                         dm->dqb_btime = 0;
2320                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2321                 }
2322                 else if (!(di->dqb_valid & QIF_BTIME))  /* Set grace only if user hasn't provided his own... */
2323                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2324         }
2325         if (check_ilim) {
2326                 if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) {
2327                         dm->dqb_itime = 0;
2328                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2329                 }
2330                 else if (!(di->dqb_valid & QIF_ITIME))  /* Set grace only if user hasn't provided his own... */
2331                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2332         }
2333         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit)
2334                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2335         else
2336                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2337         spin_unlock(&dq_data_lock);
2338         mark_dquot_dirty(dquot);
2339
2340         return 0;
2341 }
2342
2343 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
2344 {
2345         struct dquot *dquot;
2346         int rc;
2347
2348         dquot = dqget(sb, id, type);
2349         if (!dquot) {
2350                 rc = -ESRCH;
2351                 goto out;
2352         }
2353         rc = do_set_dqblk(dquot, di);
2354         dqput(dquot);
2355 out:
2356         return rc;
2357 }
2358 EXPORT_SYMBOL(vfs_set_dqblk);
2359
2360 /* Generic routine for getting common part of quota file information */
2361 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2362 {
2363         struct mem_dqinfo *mi;
2364   
2365         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2366         if (!sb_has_quota_active(sb, type)) {
2367                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2368                 return -ESRCH;
2369         }
2370         mi = sb_dqopt(sb)->info + type;
2371         spin_lock(&dq_data_lock);
2372         ii->dqi_bgrace = mi->dqi_bgrace;
2373         ii->dqi_igrace = mi->dqi_igrace;
2374         ii->dqi_flags = mi->dqi_flags & DQF_MASK;
2375         ii->dqi_valid = IIF_ALL;
2376         spin_unlock(&dq_data_lock);
2377         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2378         return 0;
2379 }
2380 EXPORT_SYMBOL(vfs_get_dqinfo);
2381
2382 /* Generic routine for setting common part of quota file information */
2383 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2384 {
2385         struct mem_dqinfo *mi;
2386         int err = 0;
2387
2388         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2389         if (!sb_has_quota_active(sb, type)) {
2390                 err = -ESRCH;
2391                 goto out;
2392         }
2393         mi = sb_dqopt(sb)->info + type;
2394         spin_lock(&dq_data_lock);
2395         if (ii->dqi_valid & IIF_BGRACE)
2396                 mi->dqi_bgrace = ii->dqi_bgrace;
2397         if (ii->dqi_valid & IIF_IGRACE)
2398                 mi->dqi_igrace = ii->dqi_igrace;
2399         if (ii->dqi_valid & IIF_FLAGS)
2400                 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | (ii->dqi_flags & DQF_MASK);
2401         spin_unlock(&dq_data_lock);
2402         mark_info_dirty(sb, type);
2403         /* Force write to disk */
2404         sb->dq_op->write_info(sb, type);
2405 out:
2406         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2407         return err;
2408 }
2409 EXPORT_SYMBOL(vfs_set_dqinfo);
2410
2411 struct quotactl_ops vfs_quotactl_ops = {
2412         .quota_on       = vfs_quota_on,
2413         .quota_off      = vfs_quota_off,
2414         .quota_sync     = vfs_quota_sync,
2415         .get_info       = vfs_get_dqinfo,
2416         .set_info       = vfs_set_dqinfo,
2417         .get_dqblk      = vfs_get_dqblk,
2418         .set_dqblk      = vfs_set_dqblk
2419 };
2420
2421 static ctl_table fs_dqstats_table[] = {
2422         {
2423                 .ctl_name       = FS_DQ_LOOKUPS,
2424                 .procname       = "lookups",
2425                 .data           = &dqstats.lookups,
2426                 .maxlen         = sizeof(int),
2427                 .mode           = 0444,
2428                 .proc_handler   = &proc_dointvec,
2429         },
2430         {
2431                 .ctl_name       = FS_DQ_DROPS,
2432                 .procname       = "drops",
2433                 .data           = &dqstats.drops,
2434                 .maxlen         = sizeof(int),
2435                 .mode           = 0444,
2436                 .proc_handler   = &proc_dointvec,
2437         },
2438         {
2439                 .ctl_name       = FS_DQ_READS,
2440                 .procname       = "reads",
2441                 .data           = &dqstats.reads,
2442                 .maxlen         = sizeof(int),
2443                 .mode           = 0444,
2444                 .proc_handler   = &proc_dointvec,
2445         },
2446         {
2447                 .ctl_name       = FS_DQ_WRITES,
2448                 .procname       = "writes",
2449                 .data           = &dqstats.writes,
2450                 .maxlen         = sizeof(int),
2451                 .mode           = 0444,
2452                 .proc_handler   = &proc_dointvec,
2453         },
2454         {
2455                 .ctl_name       = FS_DQ_CACHE_HITS,
2456                 .procname       = "cache_hits",
2457                 .data           = &dqstats.cache_hits,
2458                 .maxlen         = sizeof(int),
2459                 .mode           = 0444,
2460                 .proc_handler   = &proc_dointvec,
2461         },
2462         {
2463                 .ctl_name       = FS_DQ_ALLOCATED,
2464                 .procname       = "allocated_dquots",
2465                 .data           = &dqstats.allocated_dquots,
2466                 .maxlen         = sizeof(int),
2467                 .mode           = 0444,
2468                 .proc_handler   = &proc_dointvec,
2469         },
2470         {
2471                 .ctl_name       = FS_DQ_FREE,
2472                 .procname       = "free_dquots",
2473                 .data           = &dqstats.free_dquots,
2474                 .maxlen         = sizeof(int),
2475                 .mode           = 0444,
2476                 .proc_handler   = &proc_dointvec,
2477         },
2478         {
2479                 .ctl_name       = FS_DQ_SYNCS,
2480                 .procname       = "syncs",
2481                 .data           = &dqstats.syncs,
2482                 .maxlen         = sizeof(int),
2483                 .mode           = 0444,
2484                 .proc_handler   = &proc_dointvec,
2485         },
2486 #ifdef CONFIG_PRINT_QUOTA_WARNING
2487         {
2488                 .ctl_name       = FS_DQ_WARNINGS,
2489                 .procname       = "warnings",
2490                 .data           = &flag_print_warnings,
2491                 .maxlen         = sizeof(int),
2492                 .mode           = 0644,
2493                 .proc_handler   = &proc_dointvec,
2494         },
2495 #endif
2496         { .ctl_name = 0 },
2497 };
2498
2499 static ctl_table fs_table[] = {
2500         {
2501                 .ctl_name       = FS_DQSTATS,
2502                 .procname       = "quota",
2503                 .mode           = 0555,
2504                 .child          = fs_dqstats_table,
2505         },
2506         { .ctl_name = 0 },
2507 };
2508
2509 static ctl_table sys_table[] = {
2510         {
2511                 .ctl_name       = CTL_FS,
2512                 .procname       = "fs",
2513                 .mode           = 0555,
2514                 .child          = fs_table,
2515         },
2516         { .ctl_name = 0 },
2517 };
2518
2519 static int __init dquot_init(void)
2520 {
2521         int i;
2522         unsigned long nr_hash, order;
2523
2524         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2525
2526         register_sysctl_table(sys_table);
2527
2528         dquot_cachep = kmem_cache_create("dquot",
2529                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2530                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2531                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2532                         NULL);
2533
2534         order = 0;
2535         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2536         if (!dquot_hash)
2537                 panic("Cannot create dquot hash table");
2538
2539         /* Find power-of-two hlist_heads which can fit into allocation */
2540         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2541         dq_hash_bits = 0;
2542         do {
2543                 dq_hash_bits++;
2544         } while (nr_hash >> dq_hash_bits);
2545         dq_hash_bits--;
2546
2547         nr_hash = 1UL << dq_hash_bits;
2548         dq_hash_mask = nr_hash - 1;
2549         for (i = 0; i < nr_hash; i++)
2550                 INIT_HLIST_HEAD(dquot_hash + i);
2551
2552         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2553                         nr_hash, order, (PAGE_SIZE << order));
2554
2555         register_shrinker(&dqcache_shrinker);
2556
2557 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
2558         if (genl_register_family(&quota_genl_family) != 0)
2559                 printk(KERN_ERR "VFS: Failed to create quota netlink interface.\n");
2560 #endif
2561
2562         return 0;
2563 }
2564 module_init(dquot_init);