4881db32e56d50559fe646cfe2cef679f9e976dc
[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 NULL;
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 NULL;
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 = NULL, *empty = NULL;
726
727         if (!sb_has_quota_active(sb, type))
728                 return NULL;
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         dquot = find_dquot(hashent, sb, id, type);
740         if (!dquot) {
741                 if (!empty) {
742                         spin_unlock(&dq_list_lock);
743                         empty = get_empty_dquot(sb, type);
744                         if (!empty)
745                                 schedule();     /* Try to wait for a moment... */
746                         goto we_slept;
747                 }
748                 dquot = empty;
749                 empty = NULL;
750                 dquot->dq_id = id;
751                 /* all dquots go on the inuse_list */
752                 put_inuse(dquot);
753                 /* hash it first so it can be found */
754                 insert_dquot_hash(dquot);
755                 dqstats.lookups++;
756                 spin_unlock(&dq_list_lock);
757         } else {
758                 if (!atomic_read(&dquot->dq_count))
759                         remove_free_dquot(dquot);
760                 atomic_inc(&dquot->dq_count);
761                 dqstats.cache_hits++;
762                 dqstats.lookups++;
763                 spin_unlock(&dq_list_lock);
764         }
765         /* Wait for dq_lock - after this we know that either dquot_release() is already
766          * finished or it will be canceled due to dq_count > 1 test */
767         wait_on_dquot(dquot);
768         /* Read the dquot and instantiate it (everything done only if needed) */
769         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
770                 dqput(dquot);
771                 dquot = NULL;
772                 goto out;
773         }
774 #ifdef __DQUOT_PARANOIA
775         BUG_ON(!dquot->dq_sb);  /* Has somebody invalidated entry under us? */
776 #endif
777 out:
778         if (empty)
779                 do_destroy_dquot(empty);
780
781         return dquot;
782 }
783 EXPORT_SYMBOL(dqget);
784
785 static int dqinit_needed(struct inode *inode, int type)
786 {
787         int cnt;
788
789         if (IS_NOQUOTA(inode))
790                 return 0;
791         if (type != -1)
792                 return !inode->i_dquot[type];
793         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
794                 if (!inode->i_dquot[cnt])
795                         return 1;
796         return 0;
797 }
798
799 /* This routine is guarded by dqonoff_mutex mutex */
800 static void add_dquot_ref(struct super_block *sb, int type)
801 {
802         struct inode *inode, *old_inode = NULL;
803
804         spin_lock(&inode_lock);
805         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
806                 if (!atomic_read(&inode->i_writecount))
807                         continue;
808                 if (!dqinit_needed(inode, type))
809                         continue;
810                 if (inode->i_state & (I_FREEING|I_WILL_FREE))
811                         continue;
812
813                 __iget(inode);
814                 spin_unlock(&inode_lock);
815
816                 iput(old_inode);
817                 sb->dq_op->initialize(inode, type);
818                 /* We hold a reference to 'inode' so it couldn't have been
819                  * removed from s_inodes list while we dropped the inode_lock.
820                  * We cannot iput the inode now as we can be holding the last
821                  * reference and we cannot iput it under inode_lock. So we
822                  * keep the reference and iput it later. */
823                 old_inode = inode;
824                 spin_lock(&inode_lock);
825         }
826         spin_unlock(&inode_lock);
827         iput(old_inode);
828 }
829
830 /* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */
831 static inline int dqput_blocks(struct dquot *dquot)
832 {
833         if (atomic_read(&dquot->dq_count) <= 1)
834                 return 1;
835         return 0;
836 }
837
838 /* Remove references to dquots from inode - add dquot to list for freeing if needed */
839 /* We can't race with anybody because we hold dqptr_sem for writing... */
840 static int remove_inode_dquot_ref(struct inode *inode, int type,
841                                   struct list_head *tofree_head)
842 {
843         struct dquot *dquot = inode->i_dquot[type];
844
845         inode->i_dquot[type] = NULL;
846         if (dquot) {
847                 if (dqput_blocks(dquot)) {
848 #ifdef __DQUOT_PARANOIA
849                         if (atomic_read(&dquot->dq_count) != 1)
850                                 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
851 #endif
852                         spin_lock(&dq_list_lock);
853                         list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */
854                         spin_unlock(&dq_list_lock);
855                         return 1;
856                 }
857                 else
858                         dqput(dquot);   /* We have guaranteed we won't block */
859         }
860         return 0;
861 }
862
863 /* Free list of dquots - called from inode.c */
864 /* dquots are removed from inodes, no new references can be got so we are the only ones holding reference */
865 static void put_dquot_list(struct list_head *tofree_head)
866 {
867         struct list_head *act_head;
868         struct dquot *dquot;
869
870         act_head = tofree_head->next;
871         /* So now we have dquots on the list... Just free them */
872         while (act_head != tofree_head) {
873                 dquot = list_entry(act_head, struct dquot, dq_free);
874                 act_head = act_head->next;
875                 list_del_init(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */
876                 dqput(dquot);
877         }
878 }
879
880 static void remove_dquot_ref(struct super_block *sb, int type,
881                 struct list_head *tofree_head)
882 {
883         struct inode *inode;
884
885         spin_lock(&inode_lock);
886         list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
887                 if (!IS_NOQUOTA(inode))
888                         remove_inode_dquot_ref(inode, type, tofree_head);
889         }
890         spin_unlock(&inode_lock);
891 }
892
893 /* Gather all references from inodes and drop them */
894 static void drop_dquot_ref(struct super_block *sb, int type)
895 {
896         LIST_HEAD(tofree_head);
897
898         if (sb->dq_op) {
899                 down_write(&sb_dqopt(sb)->dqptr_sem);
900                 remove_dquot_ref(sb, type, &tofree_head);
901                 up_write(&sb_dqopt(sb)->dqptr_sem);
902                 put_dquot_list(&tofree_head);
903         }
904 }
905
906 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
907 {
908         dquot->dq_dqb.dqb_curinodes += number;
909 }
910
911 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
912 {
913         dquot->dq_dqb.dqb_curspace += number;
914 }
915
916 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
917 {
918         dquot->dq_dqb.dqb_rsvspace += number;
919 }
920
921 /*
922  * Claim reserved quota space
923  */
924 static void dquot_claim_reserved_space(struct dquot *dquot,
925                                                 qsize_t number)
926 {
927         WARN_ON(dquot->dq_dqb.dqb_rsvspace < number);
928         dquot->dq_dqb.dqb_curspace += number;
929         dquot->dq_dqb.dqb_rsvspace -= number;
930 }
931
932 static inline
933 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
934 {
935         dquot->dq_dqb.dqb_rsvspace -= number;
936 }
937
938 static inline void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
939 {
940         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
941             dquot->dq_dqb.dqb_curinodes >= number)
942                 dquot->dq_dqb.dqb_curinodes -= number;
943         else
944                 dquot->dq_dqb.dqb_curinodes = 0;
945         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
946                 dquot->dq_dqb.dqb_itime = (time_t) 0;
947         clear_bit(DQ_INODES_B, &dquot->dq_flags);
948 }
949
950 static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
951 {
952         if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
953             dquot->dq_dqb.dqb_curspace >= number)
954                 dquot->dq_dqb.dqb_curspace -= number;
955         else
956                 dquot->dq_dqb.dqb_curspace = 0;
957         if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
958                 dquot->dq_dqb.dqb_btime = (time_t) 0;
959         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
960 }
961
962 static int warning_issued(struct dquot *dquot, const int warntype)
963 {
964         int flag = (warntype == QUOTA_NL_BHARDWARN ||
965                 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
966                 ((warntype == QUOTA_NL_IHARDWARN ||
967                 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
968
969         if (!flag)
970                 return 0;
971         return test_and_set_bit(flag, &dquot->dq_flags);
972 }
973
974 #ifdef CONFIG_PRINT_QUOTA_WARNING
975 static int flag_print_warnings = 1;
976
977 static inline int need_print_warning(struct dquot *dquot)
978 {
979         if (!flag_print_warnings)
980                 return 0;
981
982         switch (dquot->dq_type) {
983                 case USRQUOTA:
984                         return current_fsuid() == dquot->dq_id;
985                 case GRPQUOTA:
986                         return in_group_p(dquot->dq_id);
987         }
988         return 0;
989 }
990
991 /* Print warning to user which exceeded quota */
992 static void print_warning(struct dquot *dquot, const int warntype)
993 {
994         char *msg = NULL;
995         struct tty_struct *tty;
996
997         if (warntype == QUOTA_NL_IHARDBELOW ||
998             warntype == QUOTA_NL_ISOFTBELOW ||
999             warntype == QUOTA_NL_BHARDBELOW ||
1000             warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
1001                 return;
1002
1003         tty = get_current_tty();
1004         if (!tty)
1005                 return;
1006         tty_write_message(tty, dquot->dq_sb->s_id);
1007         if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
1008                 tty_write_message(tty, ": warning, ");
1009         else
1010                 tty_write_message(tty, ": write failed, ");
1011         tty_write_message(tty, quotatypes[dquot->dq_type]);
1012         switch (warntype) {
1013                 case QUOTA_NL_IHARDWARN:
1014                         msg = " file limit reached.\r\n";
1015                         break;
1016                 case QUOTA_NL_ISOFTLONGWARN:
1017                         msg = " file quota exceeded too long.\r\n";
1018                         break;
1019                 case QUOTA_NL_ISOFTWARN:
1020                         msg = " file quota exceeded.\r\n";
1021                         break;
1022                 case QUOTA_NL_BHARDWARN:
1023                         msg = " block limit reached.\r\n";
1024                         break;
1025                 case QUOTA_NL_BSOFTLONGWARN:
1026                         msg = " block quota exceeded too long.\r\n";
1027                         break;
1028                 case QUOTA_NL_BSOFTWARN:
1029                         msg = " block quota exceeded.\r\n";
1030                         break;
1031         }
1032         tty_write_message(tty, msg);
1033         tty_kref_put(tty);
1034 }
1035 #endif
1036
1037 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1038
1039 /* Netlink family structure for quota */
1040 static struct genl_family quota_genl_family = {
1041         .id = GENL_ID_GENERATE,
1042         .hdrsize = 0,
1043         .name = "VFS_DQUOT",
1044         .version = 1,
1045         .maxattr = QUOTA_NL_A_MAX,
1046 };
1047
1048 /* Send warning to userspace about user which exceeded quota */
1049 static void send_warning(const struct dquot *dquot, const char warntype)
1050 {
1051         static atomic_t seq;
1052         struct sk_buff *skb;
1053         void *msg_head;
1054         int ret;
1055         int msg_size = 4 * nla_total_size(sizeof(u32)) +
1056                        2 * nla_total_size(sizeof(u64));
1057
1058         /* We have to allocate using GFP_NOFS as we are called from a
1059          * filesystem performing write and thus further recursion into
1060          * the fs to free some data could cause deadlocks. */
1061         skb = genlmsg_new(msg_size, GFP_NOFS);
1062         if (!skb) {
1063                 printk(KERN_ERR
1064                   "VFS: Not enough memory to send quota warning.\n");
1065                 return;
1066         }
1067         msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
1068                         &quota_genl_family, 0, QUOTA_NL_C_WARNING);
1069         if (!msg_head) {
1070                 printk(KERN_ERR
1071                   "VFS: Cannot store netlink header in quota warning.\n");
1072                 goto err_out;
1073         }
1074         ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type);
1075         if (ret)
1076                 goto attr_err_out;
1077         ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id);
1078         if (ret)
1079                 goto attr_err_out;
1080         ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
1081         if (ret)
1082                 goto attr_err_out;
1083         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR,
1084                 MAJOR(dquot->dq_sb->s_dev));
1085         if (ret)
1086                 goto attr_err_out;
1087         ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR,
1088                 MINOR(dquot->dq_sb->s_dev));
1089         if (ret)
1090                 goto attr_err_out;
1091         ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
1092         if (ret)
1093                 goto attr_err_out;
1094         genlmsg_end(skb, msg_head);
1095
1096         ret = genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
1097         if (ret < 0 && ret != -ESRCH)
1098                 printk(KERN_ERR
1099                         "VFS: Failed to send notification message: %d\n", ret);
1100         return;
1101 attr_err_out:
1102         printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
1103 err_out:
1104         kfree_skb(skb);
1105 }
1106 #endif
1107 /*
1108  * Write warnings to the console and send warning messages over netlink.
1109  *
1110  * Note that this function can sleep.
1111  */
1112 static inline void flush_warnings(struct dquot * const *dquots, char *warntype)
1113 {
1114         int i;
1115
1116         for (i = 0; i < MAXQUOTAS; i++)
1117                 if (dquots[i] && warntype[i] != QUOTA_NL_NOWARN &&
1118                     !warning_issued(dquots[i], warntype[i])) {
1119 #ifdef CONFIG_PRINT_QUOTA_WARNING
1120                         print_warning(dquots[i], warntype[i]);
1121 #endif
1122 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1123                         send_warning(dquots[i], warntype[i]);
1124 #endif
1125                 }
1126 }
1127
1128 static inline char ignore_hardlimit(struct dquot *dquot)
1129 {
1130         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1131
1132         return capable(CAP_SYS_RESOURCE) &&
1133             (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & V1_DQF_RSQUASH));
1134 }
1135
1136 /* needs dq_data_lock */
1137 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
1138 {
1139         *warntype = QUOTA_NL_NOWARN;
1140         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1141             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1142                 return QUOTA_OK;
1143
1144         if (dquot->dq_dqb.dqb_ihardlimit &&
1145            (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit &&
1146             !ignore_hardlimit(dquot)) {
1147                 *warntype = QUOTA_NL_IHARDWARN;
1148                 return NO_QUOTA;
1149         }
1150
1151         if (dquot->dq_dqb.dqb_isoftlimit &&
1152            (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
1153             dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime &&
1154             !ignore_hardlimit(dquot)) {
1155                 *warntype = QUOTA_NL_ISOFTLONGWARN;
1156                 return NO_QUOTA;
1157         }
1158
1159         if (dquot->dq_dqb.dqb_isoftlimit &&
1160            (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
1161             dquot->dq_dqb.dqb_itime == 0) {
1162                 *warntype = QUOTA_NL_ISOFTWARN;
1163                 dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1164         }
1165
1166         return QUOTA_OK;
1167 }
1168
1169 /* needs dq_data_lock */
1170 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1171 {
1172         qsize_t tspace;
1173
1174         *warntype = QUOTA_NL_NOWARN;
1175         if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1176             test_bit(DQ_FAKE_B, &dquot->dq_flags))
1177                 return QUOTA_OK;
1178
1179         tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1180                 + space;
1181
1182         if (dquot->dq_dqb.dqb_bhardlimit &&
1183             tspace > dquot->dq_dqb.dqb_bhardlimit &&
1184             !ignore_hardlimit(dquot)) {
1185                 if (!prealloc)
1186                         *warntype = QUOTA_NL_BHARDWARN;
1187                 return NO_QUOTA;
1188         }
1189
1190         if (dquot->dq_dqb.dqb_bsoftlimit &&
1191             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1192             dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime &&
1193             !ignore_hardlimit(dquot)) {
1194                 if (!prealloc)
1195                         *warntype = QUOTA_NL_BSOFTLONGWARN;
1196                 return NO_QUOTA;
1197         }
1198
1199         if (dquot->dq_dqb.dqb_bsoftlimit &&
1200             tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1201             dquot->dq_dqb.dqb_btime == 0) {
1202                 if (!prealloc) {
1203                         *warntype = QUOTA_NL_BSOFTWARN;
1204                         dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
1205                 }
1206                 else
1207                         /*
1208                          * We don't allow preallocation to exceed softlimit so exceeding will
1209                          * be always printed
1210                          */
1211                         return NO_QUOTA;
1212         }
1213
1214         return QUOTA_OK;
1215 }
1216
1217 static int info_idq_free(struct dquot *dquot, qsize_t inodes)
1218 {
1219         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1220             dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1221             !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
1222                 return QUOTA_NL_NOWARN;
1223
1224         if (dquot->dq_dqb.dqb_curinodes - inodes <= dquot->dq_dqb.dqb_isoftlimit)
1225                 return QUOTA_NL_ISOFTBELOW;
1226         if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
1227             dquot->dq_dqb.dqb_curinodes - inodes < dquot->dq_dqb.dqb_ihardlimit)
1228                 return QUOTA_NL_IHARDBELOW;
1229         return QUOTA_NL_NOWARN;
1230 }
1231
1232 static int info_bdq_free(struct dquot *dquot, qsize_t space)
1233 {
1234         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
1235             dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1236                 return QUOTA_NL_NOWARN;
1237
1238         if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
1239                 return QUOTA_NL_BSOFTBELOW;
1240         if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1241             dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
1242                 return QUOTA_NL_BHARDBELOW;
1243         return QUOTA_NL_NOWARN;
1244 }
1245 /*
1246  *      Initialize quota pointers in inode
1247  *      We do things in a bit complicated way but by that we avoid calling
1248  *      dqget() and thus filesystem callbacks under dqptr_sem.
1249  */
1250 int dquot_initialize(struct inode *inode, int type)
1251 {
1252         unsigned int id = 0;
1253         int cnt, ret = 0;
1254         struct dquot *got[MAXQUOTAS] = { NULL, NULL };
1255         struct super_block *sb = inode->i_sb;
1256
1257         /* First test before acquiring mutex - solves deadlocks when we
1258          * re-enter the quota code and are already holding the mutex */
1259         if (IS_NOQUOTA(inode))
1260                 return 0;
1261
1262         /* First get references to structures we might need. */
1263         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1264                 if (type != -1 && cnt != type)
1265                         continue;
1266                 switch (cnt) {
1267                 case USRQUOTA:
1268                         id = inode->i_uid;
1269                         break;
1270                 case GRPQUOTA:
1271                         id = inode->i_gid;
1272                         break;
1273                 }
1274                 got[cnt] = dqget(sb, id, cnt);
1275         }
1276
1277         down_write(&sb_dqopt(sb)->dqptr_sem);
1278         /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
1279         if (IS_NOQUOTA(inode))
1280                 goto out_err;
1281         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1282                 if (type != -1 && cnt != type)
1283                         continue;
1284                 /* Avoid races with quotaoff() */
1285                 if (!sb_has_quota_active(sb, cnt))
1286                         continue;
1287                 if (!inode->i_dquot[cnt]) {
1288                         inode->i_dquot[cnt] = got[cnt];
1289                         got[cnt] = NULL;
1290                 }
1291         }
1292 out_err:
1293         up_write(&sb_dqopt(sb)->dqptr_sem);
1294         /* Drop unused references */
1295         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1296                 dqput(got[cnt]);
1297         return ret;
1298 }
1299 EXPORT_SYMBOL(dquot_initialize);
1300
1301 /*
1302  *      Release all quotas referenced by inode
1303  */
1304 int dquot_drop(struct inode *inode)
1305 {
1306         int cnt;
1307         struct dquot *put[MAXQUOTAS];
1308
1309         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1310         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1311                 put[cnt] = inode->i_dquot[cnt];
1312                 inode->i_dquot[cnt] = NULL;
1313         }
1314         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1315
1316         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1317                 dqput(put[cnt]);
1318         return 0;
1319 }
1320 EXPORT_SYMBOL(dquot_drop);
1321
1322 /* Wrapper to remove references to quota structures from inode */
1323 void vfs_dq_drop(struct inode *inode)
1324 {
1325         /* Here we can get arbitrary inode from clear_inode() so we have
1326          * to be careful. OTOH we don't need locking as quota operations
1327          * are allowed to change only at mount time */
1328         if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op
1329             && inode->i_sb->dq_op->drop) {
1330                 int cnt;
1331                 /* Test before calling to rule out calls from proc and such
1332                  * where we are not allowed to block. Note that this is
1333                  * actually reliable test even without the lock - the caller
1334                  * must assure that nobody can come after the DQUOT_DROP and
1335                  * add quota pointers back anyway */
1336                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1337                         if (inode->i_dquot[cnt])
1338                                 break;
1339                 if (cnt < MAXQUOTAS)
1340                         inode->i_sb->dq_op->drop(inode);
1341         }
1342 }
1343 EXPORT_SYMBOL(vfs_dq_drop);
1344
1345 /*
1346  * Following four functions update i_blocks+i_bytes fields and
1347  * quota information (together with appropriate checks)
1348  * NOTE: We absolutely rely on the fact that caller dirties
1349  * the inode (usually macros in quotaops.h care about this) and
1350  * holds a handle for the current transaction so that dquot write and
1351  * inode write go into the same transaction.
1352  */
1353
1354 /*
1355  * This operation can block, but only after everything is updated
1356  */
1357 int __dquot_alloc_space(struct inode *inode, qsize_t number,
1358                         int warn, int reserve)
1359 {
1360         int cnt, ret = QUOTA_OK;
1361         char warntype[MAXQUOTAS];
1362
1363         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1364                 warntype[cnt] = QUOTA_NL_NOWARN;
1365
1366         spin_lock(&dq_data_lock);
1367         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1368                 if (!inode->i_dquot[cnt])
1369                         continue;
1370                 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt)
1371                     == NO_QUOTA) {
1372                         ret = NO_QUOTA;
1373                         goto out_unlock;
1374                 }
1375         }
1376         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1377                 if (!inode->i_dquot[cnt])
1378                         continue;
1379                 if (reserve)
1380                         dquot_resv_space(inode->i_dquot[cnt], number);
1381                 else
1382                         dquot_incr_space(inode->i_dquot[cnt], number);
1383         }
1384         if (!reserve)
1385                 inode_add_bytes(inode, number);
1386 out_unlock:
1387         spin_unlock(&dq_data_lock);
1388         flush_warnings(inode->i_dquot, warntype);
1389         return ret;
1390 }
1391
1392 int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1393 {
1394         int cnt, ret = QUOTA_OK;
1395
1396         /*
1397          * First test before acquiring mutex - solves deadlocks when we
1398          * re-enter the quota code and are already holding the mutex
1399          */
1400         if (IS_NOQUOTA(inode)) {
1401                 inode_add_bytes(inode, number);
1402                 goto out;
1403         }
1404
1405         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1406         if (IS_NOQUOTA(inode)) {
1407                 inode_add_bytes(inode, number);
1408                 goto out_unlock;
1409         }
1410
1411         ret = __dquot_alloc_space(inode, number, warn, 0);
1412         if (ret == NO_QUOTA)
1413                 goto out_unlock;
1414
1415         /* Dirtify all the dquots - this can block when journalling */
1416         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1417                 if (inode->i_dquot[cnt])
1418                         mark_dquot_dirty(inode->i_dquot[cnt]);
1419 out_unlock:
1420         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1421 out:
1422         return ret;
1423 }
1424 EXPORT_SYMBOL(dquot_alloc_space);
1425
1426 int dquot_reserve_space(struct inode *inode, qsize_t number, int warn)
1427 {
1428         int ret = QUOTA_OK;
1429
1430         if (IS_NOQUOTA(inode))
1431                 goto out;
1432
1433         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1434         if (IS_NOQUOTA(inode))
1435                 goto out_unlock;
1436
1437         ret = __dquot_alloc_space(inode, number, warn, 1);
1438 out_unlock:
1439         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1440 out:
1441         return ret;
1442 }
1443 EXPORT_SYMBOL(dquot_reserve_space);
1444
1445 /*
1446  * This operation can block, but only after everything is updated
1447  */
1448 int dquot_alloc_inode(const struct inode *inode, qsize_t number)
1449 {
1450         int cnt, ret = NO_QUOTA;
1451         char warntype[MAXQUOTAS];
1452
1453         /* First test before acquiring mutex - solves deadlocks when we
1454          * re-enter the quota code and are already holding the mutex */
1455         if (IS_NOQUOTA(inode))
1456                 return QUOTA_OK;
1457         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1458                 warntype[cnt] = QUOTA_NL_NOWARN;
1459         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1460         if (IS_NOQUOTA(inode)) {
1461                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1462                 return QUOTA_OK;
1463         }
1464         spin_lock(&dq_data_lock);
1465         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1466                 if (!inode->i_dquot[cnt])
1467                         continue;
1468                 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA)
1469                         goto warn_put_all;
1470         }
1471
1472         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1473                 if (!inode->i_dquot[cnt])
1474                         continue;
1475                 dquot_incr_inodes(inode->i_dquot[cnt], number);
1476         }
1477         ret = QUOTA_OK;
1478 warn_put_all:
1479         spin_unlock(&dq_data_lock);
1480         if (ret == QUOTA_OK)
1481                 /* Dirtify all the dquots - this can block when journalling */
1482                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1483                         if (inode->i_dquot[cnt])
1484                                 mark_dquot_dirty(inode->i_dquot[cnt]);
1485         flush_warnings(inode->i_dquot, warntype);
1486         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1487         return ret;
1488 }
1489 EXPORT_SYMBOL(dquot_alloc_inode);
1490
1491 int dquot_claim_space(struct inode *inode, qsize_t number)
1492 {
1493         int cnt;
1494         int ret = QUOTA_OK;
1495
1496         if (IS_NOQUOTA(inode)) {
1497                 inode_add_bytes(inode, number);
1498                 goto out;
1499         }
1500
1501         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1502         if (IS_NOQUOTA(inode))  {
1503                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1504                 inode_add_bytes(inode, number);
1505                 goto out;
1506         }
1507
1508         spin_lock(&dq_data_lock);
1509         /* Claim reserved quotas to allocated quotas */
1510         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1511                 if (inode->i_dquot[cnt])
1512                         dquot_claim_reserved_space(inode->i_dquot[cnt],
1513                                                         number);
1514         }
1515         /* Update inode bytes */
1516         inode_add_bytes(inode, number);
1517         spin_unlock(&dq_data_lock);
1518         /* Dirtify all the dquots - this can block when journalling */
1519         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1520                 if (inode->i_dquot[cnt])
1521                         mark_dquot_dirty(inode->i_dquot[cnt]);
1522         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1523 out:
1524         return ret;
1525 }
1526 EXPORT_SYMBOL(dquot_claim_space);
1527
1528 /*
1529  * Release reserved quota space
1530  */
1531 void dquot_release_reserved_space(struct inode *inode, qsize_t number)
1532 {
1533         int cnt;
1534
1535         if (IS_NOQUOTA(inode))
1536                 goto out;
1537
1538         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1539         if (IS_NOQUOTA(inode))
1540                 goto out_unlock;
1541
1542         spin_lock(&dq_data_lock);
1543         /* Release reserved dquots */
1544         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1545                 if (inode->i_dquot[cnt])
1546                         dquot_free_reserved_space(inode->i_dquot[cnt], number);
1547         }
1548         spin_unlock(&dq_data_lock);
1549
1550 out_unlock:
1551         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1552 out:
1553         return;
1554 }
1555 EXPORT_SYMBOL(dquot_release_reserved_space);
1556
1557 /*
1558  * This operation can block, but only after everything is updated
1559  */
1560 int dquot_free_space(struct inode *inode, qsize_t number)
1561 {
1562         unsigned int cnt;
1563         char warntype[MAXQUOTAS];
1564
1565         /* First test before acquiring mutex - solves deadlocks when we
1566          * re-enter the quota code and are already holding the mutex */
1567         if (IS_NOQUOTA(inode)) {
1568 out_sub:
1569                 inode_sub_bytes(inode, number);
1570                 return QUOTA_OK;
1571         }
1572
1573         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1574         /* Now recheck reliably when holding dqptr_sem */
1575         if (IS_NOQUOTA(inode)) {
1576                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1577                 goto out_sub;
1578         }
1579         spin_lock(&dq_data_lock);
1580         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1581                 if (!inode->i_dquot[cnt])
1582                         continue;
1583                 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
1584                 dquot_decr_space(inode->i_dquot[cnt], number);
1585         }
1586         inode_sub_bytes(inode, number);
1587         spin_unlock(&dq_data_lock);
1588         /* Dirtify all the dquots - this can block when journalling */
1589         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1590                 if (inode->i_dquot[cnt])
1591                         mark_dquot_dirty(inode->i_dquot[cnt]);
1592         flush_warnings(inode->i_dquot, warntype);
1593         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1594         return QUOTA_OK;
1595 }
1596 EXPORT_SYMBOL(dquot_free_space);
1597
1598 /*
1599  * This operation can block, but only after everything is updated
1600  */
1601 int dquot_free_inode(const struct inode *inode, qsize_t number)
1602 {
1603         unsigned int cnt;
1604         char warntype[MAXQUOTAS];
1605
1606         /* First test before acquiring mutex - solves deadlocks when we
1607          * re-enter the quota code and are already holding the mutex */
1608         if (IS_NOQUOTA(inode))
1609                 return QUOTA_OK;
1610
1611         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1612         /* Now recheck reliably when holding dqptr_sem */
1613         if (IS_NOQUOTA(inode)) {
1614                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1615                 return QUOTA_OK;
1616         }
1617         spin_lock(&dq_data_lock);
1618         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1619                 if (!inode->i_dquot[cnt])
1620                         continue;
1621                 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], number);
1622                 dquot_decr_inodes(inode->i_dquot[cnt], number);
1623         }
1624         spin_unlock(&dq_data_lock);
1625         /* Dirtify all the dquots - this can block when journalling */
1626         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1627                 if (inode->i_dquot[cnt])
1628                         mark_dquot_dirty(inode->i_dquot[cnt]);
1629         flush_warnings(inode->i_dquot, warntype);
1630         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1631         return QUOTA_OK;
1632 }
1633 EXPORT_SYMBOL(dquot_free_inode);
1634
1635 /*
1636  * call back function, get reserved quota space from underlying fs
1637  */
1638 qsize_t dquot_get_reserved_space(struct inode *inode)
1639 {
1640         qsize_t reserved_space = 0;
1641
1642         if (sb_any_quota_active(inode->i_sb) &&
1643             inode->i_sb->dq_op->get_reserved_space)
1644                 reserved_space = inode->i_sb->dq_op->get_reserved_space(inode);
1645         return reserved_space;
1646 }
1647
1648 /*
1649  * Transfer the number of inode and blocks from one diskquota to an other.
1650  *
1651  * This operation can block, but only after everything is updated
1652  * A transaction must be started when entering this function.
1653  */
1654 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1655 {
1656         qsize_t space, cur_space;
1657         qsize_t rsv_space = 0;
1658         struct dquot *transfer_from[MAXQUOTAS];
1659         struct dquot *transfer_to[MAXQUOTAS];
1660         int cnt, ret = QUOTA_OK;
1661         int chuid = iattr->ia_valid & ATTR_UID && inode->i_uid != iattr->ia_uid,
1662             chgid = iattr->ia_valid & ATTR_GID && inode->i_gid != iattr->ia_gid;
1663         char warntype_to[MAXQUOTAS];
1664         char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
1665
1666         /* First test before acquiring mutex - solves deadlocks when we
1667          * re-enter the quota code and are already holding the mutex */
1668         if (IS_NOQUOTA(inode))
1669                 return QUOTA_OK;
1670         /* Initialize the arrays */
1671         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1672                 transfer_from[cnt] = NULL;
1673                 transfer_to[cnt] = NULL;
1674                 warntype_to[cnt] = QUOTA_NL_NOWARN;
1675                 switch (cnt) {
1676                         case USRQUOTA:
1677                                 if (!chuid)
1678                                         continue;
1679                                 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt);
1680                                 break;
1681                         case GRPQUOTA:
1682                                 if (!chgid)
1683                                         continue;
1684                                 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt);
1685                                 break;
1686                 }
1687         }
1688
1689         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1690         /* Now recheck reliably when holding dqptr_sem */
1691         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1692                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1693                 goto put_all;
1694         }
1695         spin_lock(&dq_data_lock);
1696         cur_space = inode_get_bytes(inode);
1697         rsv_space = dquot_get_reserved_space(inode);
1698         space = cur_space + rsv_space;
1699         /* Build the transfer_from list and check the limits */
1700         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1701                 if (!transfer_to[cnt])
1702                         continue;
1703                 transfer_from[cnt] = inode->i_dquot[cnt];
1704                 if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) ==
1705                     NO_QUOTA || check_bdq(transfer_to[cnt], space, 0,
1706                     warntype_to + cnt) == NO_QUOTA)
1707                         goto over_quota;
1708         }
1709
1710         /*
1711          * Finally perform the needed transfer from transfer_from to transfer_to
1712          */
1713         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1714                 /*
1715                  * Skip changes for same uid or gid or for turned off quota-type.
1716                  */
1717                 if (!transfer_to[cnt])
1718                         continue;
1719
1720                 /* Due to IO error we might not have transfer_from[] structure */
1721                 if (transfer_from[cnt]) {
1722                         warntype_from_inodes[cnt] =
1723                                 info_idq_free(transfer_from[cnt], 1);
1724                         warntype_from_space[cnt] =
1725                                 info_bdq_free(transfer_from[cnt], space);
1726                         dquot_decr_inodes(transfer_from[cnt], 1);
1727                         dquot_decr_space(transfer_from[cnt], cur_space);
1728                         dquot_free_reserved_space(transfer_from[cnt],
1729                                                   rsv_space);
1730                 }
1731
1732                 dquot_incr_inodes(transfer_to[cnt], 1);
1733                 dquot_incr_space(transfer_to[cnt], cur_space);
1734                 dquot_resv_space(transfer_to[cnt], rsv_space);
1735
1736                 inode->i_dquot[cnt] = transfer_to[cnt];
1737         }
1738         spin_unlock(&dq_data_lock);
1739         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1740
1741         /* Dirtify all the dquots - this can block when journalling */
1742         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1743                 if (transfer_from[cnt])
1744                         mark_dquot_dirty(transfer_from[cnt]);
1745                 if (transfer_to[cnt]) {
1746                         mark_dquot_dirty(transfer_to[cnt]);
1747                         /* The reference we got is transferred to the inode */
1748                         transfer_to[cnt] = NULL;
1749                 }
1750         }
1751 warn_put_all:
1752         flush_warnings(transfer_to, warntype_to);
1753         flush_warnings(transfer_from, warntype_from_inodes);
1754         flush_warnings(transfer_from, warntype_from_space);
1755 put_all:
1756         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1757                 dqput(transfer_from[cnt]);
1758                 dqput(transfer_to[cnt]);
1759         }
1760         return ret;
1761 over_quota:
1762         spin_unlock(&dq_data_lock);
1763         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1764         /* Clear dquot pointers we don't want to dqput() */
1765         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1766                 transfer_from[cnt] = NULL;
1767         ret = NO_QUOTA;
1768         goto warn_put_all;
1769 }
1770 EXPORT_SYMBOL(dquot_transfer);
1771
1772 /* Wrapper for transferring ownership of an inode */
1773 int vfs_dq_transfer(struct inode *inode, struct iattr *iattr)
1774 {
1775         if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) {
1776                 vfs_dq_init(inode);
1777                 if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA)
1778                         return 1;
1779         }
1780         return 0;
1781 }
1782 EXPORT_SYMBOL(vfs_dq_transfer);
1783
1784 /*
1785  * Write info of quota file to disk
1786  */
1787 int dquot_commit_info(struct super_block *sb, int type)
1788 {
1789         int ret;
1790         struct quota_info *dqopt = sb_dqopt(sb);
1791
1792         mutex_lock(&dqopt->dqio_mutex);
1793         ret = dqopt->ops[type]->write_file_info(sb, type);
1794         mutex_unlock(&dqopt->dqio_mutex);
1795         return ret;
1796 }
1797 EXPORT_SYMBOL(dquot_commit_info);
1798
1799 /*
1800  * Definitions of diskquota operations.
1801  */
1802 struct dquot_operations dquot_operations = {
1803         .initialize     = dquot_initialize,
1804         .drop           = dquot_drop,
1805         .alloc_space    = dquot_alloc_space,
1806         .alloc_inode    = dquot_alloc_inode,
1807         .free_space     = dquot_free_space,
1808         .free_inode     = dquot_free_inode,
1809         .transfer       = dquot_transfer,
1810         .write_dquot    = dquot_commit,
1811         .acquire_dquot  = dquot_acquire,
1812         .release_dquot  = dquot_release,
1813         .mark_dirty     = dquot_mark_dquot_dirty,
1814         .write_info     = dquot_commit_info,
1815         .alloc_dquot    = dquot_alloc,
1816         .destroy_dquot  = dquot_destroy,
1817 };
1818
1819 /*
1820  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1821  */
1822 int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags)
1823 {
1824         int cnt, ret = 0;
1825         struct quota_info *dqopt = sb_dqopt(sb);
1826         struct inode *toputinode[MAXQUOTAS];
1827
1828         /* Cannot turn off usage accounting without turning off limits, or
1829          * suspend quotas and simultaneously turn quotas off. */
1830         if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1831             || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1832             DQUOT_USAGE_ENABLED)))
1833                 return -EINVAL;
1834
1835         /* We need to serialize quota_off() for device */
1836         mutex_lock(&dqopt->dqonoff_mutex);
1837
1838         /*
1839          * Skip everything if there's nothing to do. We have to do this because
1840          * sometimes we are called when fill_super() failed and calling
1841          * sync_fs() in such cases does no good.
1842          */
1843         if (!sb_any_quota_loaded(sb)) {
1844                 mutex_unlock(&dqopt->dqonoff_mutex);
1845                 return 0;
1846         }
1847         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1848                 toputinode[cnt] = NULL;
1849                 if (type != -1 && cnt != type)
1850                         continue;
1851                 if (!sb_has_quota_loaded(sb, cnt))
1852                         continue;
1853
1854                 if (flags & DQUOT_SUSPENDED) {
1855                         spin_lock(&dq_state_lock);
1856                         dqopt->flags |=
1857                                 dquot_state_flag(DQUOT_SUSPENDED, cnt);
1858                         spin_unlock(&dq_state_lock);
1859                 } else {
1860                         spin_lock(&dq_state_lock);
1861                         dqopt->flags &= ~dquot_state_flag(flags, cnt);
1862                         /* Turning off suspended quotas? */
1863                         if (!sb_has_quota_loaded(sb, cnt) &&
1864                             sb_has_quota_suspended(sb, cnt)) {
1865                                 dqopt->flags &= ~dquot_state_flag(
1866                                                         DQUOT_SUSPENDED, cnt);
1867                                 spin_unlock(&dq_state_lock);
1868                                 iput(dqopt->files[cnt]);
1869                                 dqopt->files[cnt] = NULL;
1870                                 continue;
1871                         }
1872                         spin_unlock(&dq_state_lock);
1873                 }
1874
1875                 /* We still have to keep quota loaded? */
1876                 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
1877                         continue;
1878
1879                 /* Note: these are blocking operations */
1880                 drop_dquot_ref(sb, cnt);
1881                 invalidate_dquots(sb, cnt);
1882                 /*
1883                  * Now all dquots should be invalidated, all writes done so we should be only
1884                  * users of the info. No locks needed.
1885                  */
1886                 if (info_dirty(&dqopt->info[cnt]))
1887                         sb->dq_op->write_info(sb, cnt);
1888                 if (dqopt->ops[cnt]->free_file_info)
1889                         dqopt->ops[cnt]->free_file_info(sb, cnt);
1890                 put_quota_format(dqopt->info[cnt].dqi_format);
1891
1892                 toputinode[cnt] = dqopt->files[cnt];
1893                 if (!sb_has_quota_loaded(sb, cnt))
1894                         dqopt->files[cnt] = NULL;
1895                 dqopt->info[cnt].dqi_flags = 0;
1896                 dqopt->info[cnt].dqi_igrace = 0;
1897                 dqopt->info[cnt].dqi_bgrace = 0;
1898                 dqopt->ops[cnt] = NULL;
1899         }
1900         mutex_unlock(&dqopt->dqonoff_mutex);
1901
1902         /* Skip syncing and setting flags if quota files are hidden */
1903         if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
1904                 goto put_inodes;
1905
1906         /* Sync the superblock so that buffers with quota data are written to
1907          * disk (and so userspace sees correct data afterwards). */
1908         if (sb->s_op->sync_fs)
1909                 sb->s_op->sync_fs(sb, 1);
1910         sync_blockdev(sb->s_bdev);
1911         /* Now the quota files are just ordinary files and we can set the
1912          * inode flags back. Moreover we discard the pagecache so that
1913          * userspace sees the writes we did bypassing the pagecache. We
1914          * must also discard the blockdev buffers so that we see the
1915          * changes done by userspace on the next quotaon() */
1916         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1917                 if (toputinode[cnt]) {
1918                         mutex_lock(&dqopt->dqonoff_mutex);
1919                         /* If quota was reenabled in the meantime, we have
1920                          * nothing to do */
1921                         if (!sb_has_quota_loaded(sb, cnt)) {
1922                                 mutex_lock_nested(&toputinode[cnt]->i_mutex, I_MUTEX_QUOTA);
1923                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1924                                   S_NOATIME | S_NOQUOTA);
1925                                 truncate_inode_pages(&toputinode[cnt]->i_data, 0);
1926                                 mutex_unlock(&toputinode[cnt]->i_mutex);
1927                                 mark_inode_dirty(toputinode[cnt]);
1928                         }
1929                         mutex_unlock(&dqopt->dqonoff_mutex);
1930                 }
1931         if (sb->s_bdev)
1932                 invalidate_bdev(sb->s_bdev);
1933 put_inodes:
1934         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1935                 if (toputinode[cnt]) {
1936                         /* On remount RO, we keep the inode pointer so that we
1937                          * can reenable quota on the subsequent remount RW. We
1938                          * have to check 'flags' variable and not use sb_has_
1939                          * function because another quotaon / quotaoff could
1940                          * change global state before we got here. We refuse
1941                          * to suspend quotas when there is pending delete on
1942                          * the quota file... */
1943                         if (!(flags & DQUOT_SUSPENDED))
1944                                 iput(toputinode[cnt]);
1945                         else if (!toputinode[cnt]->i_nlink)
1946                                 ret = -EBUSY;
1947                 }
1948         return ret;
1949 }
1950 EXPORT_SYMBOL(vfs_quota_disable);
1951
1952 int vfs_quota_off(struct super_block *sb, int type, int remount)
1953 {
1954         return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED :
1955                                  (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED));
1956 }
1957 EXPORT_SYMBOL(vfs_quota_off);
1958 /*
1959  *      Turn quotas on on a device
1960  */
1961
1962 /*
1963  * Helper function to turn quotas on when we already have the inode of
1964  * quota file and no quota information is loaded.
1965  */
1966 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
1967         unsigned int flags)
1968 {
1969         struct quota_format_type *fmt = find_quota_format(format_id);
1970         struct super_block *sb = inode->i_sb;
1971         struct quota_info *dqopt = sb_dqopt(sb);
1972         int error;
1973         int oldflags = -1;
1974
1975         if (!fmt)
1976                 return -ESRCH;
1977         if (!S_ISREG(inode->i_mode)) {
1978                 error = -EACCES;
1979                 goto out_fmt;
1980         }
1981         if (IS_RDONLY(inode)) {
1982                 error = -EROFS;
1983                 goto out_fmt;
1984         }
1985         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
1986                 error = -EINVAL;
1987                 goto out_fmt;
1988         }
1989         /* Usage always has to be set... */
1990         if (!(flags & DQUOT_USAGE_ENABLED)) {
1991                 error = -EINVAL;
1992                 goto out_fmt;
1993         }
1994
1995         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
1996                 /* As we bypass the pagecache we must now flush the inode so
1997                  * that we see all the changes from userspace... */
1998                 write_inode_now(inode, 1);
1999                 /* And now flush the block cache so that kernel sees the
2000                  * changes */
2001                 invalidate_bdev(sb->s_bdev);
2002         }
2003         mutex_lock(&inode->i_mutex);
2004         mutex_lock(&dqopt->dqonoff_mutex);
2005         if (sb_has_quota_loaded(sb, type)) {
2006                 error = -EBUSY;
2007                 goto out_lock;
2008         }
2009
2010         if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2011                 /* We don't want quota and atime on quota files (deadlocks
2012                  * possible) Also nobody should write to the file - we use
2013                  * special IO operations which ignore the immutable bit. */
2014                 down_write(&dqopt->dqptr_sem);
2015                 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA);
2016                 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
2017                 up_write(&dqopt->dqptr_sem);
2018                 sb->dq_op->drop(inode);
2019         }
2020
2021         error = -EIO;
2022         dqopt->files[type] = igrab(inode);
2023         if (!dqopt->files[type])
2024                 goto out_lock;
2025         error = -EINVAL;
2026         if (!fmt->qf_ops->check_quota_file(sb, type))
2027                 goto out_file_init;
2028
2029         dqopt->ops[type] = fmt->qf_ops;
2030         dqopt->info[type].dqi_format = fmt;
2031         dqopt->info[type].dqi_fmt_id = format_id;
2032         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
2033         mutex_lock(&dqopt->dqio_mutex);
2034         if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) {
2035                 mutex_unlock(&dqopt->dqio_mutex);
2036                 goto out_file_init;
2037         }
2038         mutex_unlock(&dqopt->dqio_mutex);
2039         mutex_unlock(&inode->i_mutex);
2040         spin_lock(&dq_state_lock);
2041         dqopt->flags |= dquot_state_flag(flags, type);
2042         spin_unlock(&dq_state_lock);
2043
2044         add_dquot_ref(sb, type);
2045         mutex_unlock(&dqopt->dqonoff_mutex);
2046
2047         return 0;
2048
2049 out_file_init:
2050         dqopt->files[type] = NULL;
2051         iput(inode);
2052 out_lock:
2053         mutex_unlock(&dqopt->dqonoff_mutex);
2054         if (oldflags != -1) {
2055                 down_write(&dqopt->dqptr_sem);
2056                 /* Set the flags back (in the case of accidental quotaon()
2057                  * on a wrong file we don't want to mess up the flags) */
2058                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2059                 inode->i_flags |= oldflags;
2060                 up_write(&dqopt->dqptr_sem);
2061         }
2062         mutex_unlock(&inode->i_mutex);
2063 out_fmt:
2064         put_quota_format(fmt);
2065
2066         return error; 
2067 }
2068
2069 /* Reenable quotas on remount RW */
2070 static int vfs_quota_on_remount(struct super_block *sb, int type)
2071 {
2072         struct quota_info *dqopt = sb_dqopt(sb);
2073         struct inode *inode;
2074         int ret;
2075         unsigned int flags;
2076
2077         mutex_lock(&dqopt->dqonoff_mutex);
2078         if (!sb_has_quota_suspended(sb, type)) {
2079                 mutex_unlock(&dqopt->dqonoff_mutex);
2080                 return 0;
2081         }
2082         inode = dqopt->files[type];
2083         dqopt->files[type] = NULL;
2084         spin_lock(&dq_state_lock);
2085         flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2086                                                 DQUOT_LIMITS_ENABLED, type);
2087         dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type);
2088         spin_unlock(&dq_state_lock);
2089         mutex_unlock(&dqopt->dqonoff_mutex);
2090
2091         flags = dquot_generic_flag(flags, type);
2092         ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id,
2093                                    flags);
2094         iput(inode);
2095
2096         return ret;
2097 }
2098
2099 int vfs_quota_on_path(struct super_block *sb, int type, int format_id,
2100                       struct path *path)
2101 {
2102         int error = security_quota_on(path->dentry);
2103         if (error)
2104                 return error;
2105         /* Quota file not on the same filesystem? */
2106         if (path->mnt->mnt_sb != sb)
2107                 error = -EXDEV;
2108         else
2109                 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2110                                              format_id, DQUOT_USAGE_ENABLED |
2111                                              DQUOT_LIMITS_ENABLED);
2112         return error;
2113 }
2114 EXPORT_SYMBOL(vfs_quota_on_path);
2115
2116 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name,
2117                  int remount)
2118 {
2119         struct path path;
2120         int error;
2121
2122         if (remount)
2123                 return vfs_quota_on_remount(sb, type);
2124
2125         error = kern_path(name, LOOKUP_FOLLOW, &path);
2126         if (!error) {
2127                 error = vfs_quota_on_path(sb, type, format_id, &path);
2128                 path_put(&path);
2129         }
2130         return error;
2131 }
2132 EXPORT_SYMBOL(vfs_quota_on);
2133
2134 /*
2135  * More powerful function for turning on quotas allowing setting
2136  * of individual quota flags
2137  */
2138 int vfs_quota_enable(struct inode *inode, int type, int format_id,
2139                 unsigned int flags)
2140 {
2141         int ret = 0;
2142         struct super_block *sb = inode->i_sb;
2143         struct quota_info *dqopt = sb_dqopt(sb);
2144
2145         /* Just unsuspend quotas? */
2146         if (flags & DQUOT_SUSPENDED)
2147                 return vfs_quota_on_remount(sb, type);
2148         if (!flags)
2149                 return 0;
2150         /* Just updating flags needed? */
2151         if (sb_has_quota_loaded(sb, type)) {
2152                 mutex_lock(&dqopt->dqonoff_mutex);
2153                 /* Now do a reliable test... */
2154                 if (!sb_has_quota_loaded(sb, type)) {
2155                         mutex_unlock(&dqopt->dqonoff_mutex);
2156                         goto load_quota;
2157                 }
2158                 if (flags & DQUOT_USAGE_ENABLED &&
2159                     sb_has_quota_usage_enabled(sb, type)) {
2160                         ret = -EBUSY;
2161                         goto out_lock;
2162                 }
2163                 if (flags & DQUOT_LIMITS_ENABLED &&
2164                     sb_has_quota_limits_enabled(sb, type)) {
2165                         ret = -EBUSY;
2166                         goto out_lock;
2167                 }
2168                 spin_lock(&dq_state_lock);
2169                 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2170                 spin_unlock(&dq_state_lock);
2171 out_lock:
2172                 mutex_unlock(&dqopt->dqonoff_mutex);
2173                 return ret;
2174         }
2175
2176 load_quota:
2177         return vfs_load_quota_inode(inode, type, format_id, flags);
2178 }
2179 EXPORT_SYMBOL(vfs_quota_enable);
2180
2181 /*
2182  * This function is used when filesystem needs to initialize quotas
2183  * during mount time.
2184  */
2185 int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
2186                 int format_id, int type)
2187 {
2188         struct dentry *dentry;
2189         int error;
2190
2191         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
2192         if (IS_ERR(dentry))
2193                 return PTR_ERR(dentry);
2194
2195         if (!dentry->d_inode) {
2196                 error = -ENOENT;
2197                 goto out;
2198         }
2199
2200         error = security_quota_on(dentry);
2201         if (!error)
2202                 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2203                                 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
2204
2205 out:
2206         dput(dentry);
2207         return error;
2208 }
2209 EXPORT_SYMBOL(vfs_quota_on_mount);
2210
2211 /* Wrapper to turn on quotas when remounting rw */
2212 int vfs_dq_quota_on_remount(struct super_block *sb)
2213 {
2214         int cnt;
2215         int ret = 0, err;
2216
2217         if (!sb->s_qcop || !sb->s_qcop->quota_on)
2218                 return -ENOSYS;
2219         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2220                 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1);
2221                 if (err < 0 && !ret)
2222                         ret = err;
2223         }
2224         return ret;
2225 }
2226 EXPORT_SYMBOL(vfs_dq_quota_on_remount);
2227
2228 static inline qsize_t qbtos(qsize_t blocks)
2229 {
2230         return blocks << QIF_DQBLKSIZE_BITS;
2231 }
2232
2233 static inline qsize_t stoqb(qsize_t space)
2234 {
2235         return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2236 }
2237
2238 /* Generic routine for getting common part of quota structure */
2239 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
2240 {
2241         struct mem_dqblk *dm = &dquot->dq_dqb;
2242
2243         spin_lock(&dq_data_lock);
2244         di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit);
2245         di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit);
2246         di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace;
2247         di->dqb_ihardlimit = dm->dqb_ihardlimit;
2248         di->dqb_isoftlimit = dm->dqb_isoftlimit;
2249         di->dqb_curinodes = dm->dqb_curinodes;
2250         di->dqb_btime = dm->dqb_btime;
2251         di->dqb_itime = dm->dqb_itime;
2252         di->dqb_valid = QIF_ALL;
2253         spin_unlock(&dq_data_lock);
2254 }
2255
2256 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
2257 {
2258         struct dquot *dquot;
2259
2260         dquot = dqget(sb, id, type);
2261         if (!dquot)
2262                 return -ESRCH;
2263         do_get_dqblk(dquot, di);
2264         dqput(dquot);
2265
2266         return 0;
2267 }
2268 EXPORT_SYMBOL(vfs_get_dqblk);
2269
2270 /* Generic routine for setting common part of quota structure */
2271 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
2272 {
2273         struct mem_dqblk *dm = &dquot->dq_dqb;
2274         int check_blim = 0, check_ilim = 0;
2275         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2276
2277         if ((di->dqb_valid & QIF_BLIMITS &&
2278              (di->dqb_bhardlimit > dqi->dqi_maxblimit ||
2279               di->dqb_bsoftlimit > dqi->dqi_maxblimit)) ||
2280             (di->dqb_valid & QIF_ILIMITS &&
2281              (di->dqb_ihardlimit > dqi->dqi_maxilimit ||
2282               di->dqb_isoftlimit > dqi->dqi_maxilimit)))
2283                 return -ERANGE;
2284
2285         spin_lock(&dq_data_lock);
2286         if (di->dqb_valid & QIF_SPACE) {
2287                 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace;
2288                 check_blim = 1;
2289                 __set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
2290         }
2291         if (di->dqb_valid & QIF_BLIMITS) {
2292                 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit);
2293                 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit);
2294                 check_blim = 1;
2295                 __set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
2296         }
2297         if (di->dqb_valid & QIF_INODES) {
2298                 dm->dqb_curinodes = di->dqb_curinodes;
2299                 check_ilim = 1;
2300                 __set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
2301         }
2302         if (di->dqb_valid & QIF_ILIMITS) {
2303                 dm->dqb_isoftlimit = di->dqb_isoftlimit;
2304                 dm->dqb_ihardlimit = di->dqb_ihardlimit;
2305                 check_ilim = 1;
2306                 __set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
2307         }
2308         if (di->dqb_valid & QIF_BTIME) {
2309                 dm->dqb_btime = di->dqb_btime;
2310                 check_blim = 1;
2311                 __set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2312         }
2313         if (di->dqb_valid & QIF_ITIME) {
2314                 dm->dqb_itime = di->dqb_itime;
2315                 check_ilim = 1;
2316                 __set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2317         }
2318
2319         if (check_blim) {
2320                 if (!dm->dqb_bsoftlimit || dm->dqb_curspace < dm->dqb_bsoftlimit) {
2321                         dm->dqb_btime = 0;
2322                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
2323                 }
2324                 else if (!(di->dqb_valid & QIF_BTIME))  /* Set grace only if user hasn't provided his own... */
2325                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
2326         }
2327         if (check_ilim) {
2328                 if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) {
2329                         dm->dqb_itime = 0;
2330                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
2331                 }
2332                 else if (!(di->dqb_valid & QIF_ITIME))  /* Set grace only if user hasn't provided his own... */
2333                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
2334         }
2335         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit)
2336                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2337         else
2338                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2339         spin_unlock(&dq_data_lock);
2340         mark_dquot_dirty(dquot);
2341
2342         return 0;
2343 }
2344
2345 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
2346 {
2347         struct dquot *dquot;
2348         int rc;
2349
2350         dquot = dqget(sb, id, type);
2351         if (!dquot) {
2352                 rc = -ESRCH;
2353                 goto out;
2354         }
2355         rc = do_set_dqblk(dquot, di);
2356         dqput(dquot);
2357 out:
2358         return rc;
2359 }
2360 EXPORT_SYMBOL(vfs_set_dqblk);
2361
2362 /* Generic routine for getting common part of quota file information */
2363 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2364 {
2365         struct mem_dqinfo *mi;
2366   
2367         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2368         if (!sb_has_quota_active(sb, type)) {
2369                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2370                 return -ESRCH;
2371         }
2372         mi = sb_dqopt(sb)->info + type;
2373         spin_lock(&dq_data_lock);
2374         ii->dqi_bgrace = mi->dqi_bgrace;
2375         ii->dqi_igrace = mi->dqi_igrace;
2376         ii->dqi_flags = mi->dqi_flags & DQF_MASK;
2377         ii->dqi_valid = IIF_ALL;
2378         spin_unlock(&dq_data_lock);
2379         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2380         return 0;
2381 }
2382 EXPORT_SYMBOL(vfs_get_dqinfo);
2383
2384 /* Generic routine for setting common part of quota file information */
2385 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2386 {
2387         struct mem_dqinfo *mi;
2388         int err = 0;
2389
2390         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
2391         if (!sb_has_quota_active(sb, type)) {
2392                 err = -ESRCH;
2393                 goto out;
2394         }
2395         mi = sb_dqopt(sb)->info + type;
2396         spin_lock(&dq_data_lock);
2397         if (ii->dqi_valid & IIF_BGRACE)
2398                 mi->dqi_bgrace = ii->dqi_bgrace;
2399         if (ii->dqi_valid & IIF_IGRACE)
2400                 mi->dqi_igrace = ii->dqi_igrace;
2401         if (ii->dqi_valid & IIF_FLAGS)
2402                 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | (ii->dqi_flags & DQF_MASK);
2403         spin_unlock(&dq_data_lock);
2404         mark_info_dirty(sb, type);
2405         /* Force write to disk */
2406         sb->dq_op->write_info(sb, type);
2407 out:
2408         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
2409         return err;
2410 }
2411 EXPORT_SYMBOL(vfs_set_dqinfo);
2412
2413 struct quotactl_ops vfs_quotactl_ops = {
2414         .quota_on       = vfs_quota_on,
2415         .quota_off      = vfs_quota_off,
2416         .quota_sync     = vfs_quota_sync,
2417         .get_info       = vfs_get_dqinfo,
2418         .set_info       = vfs_set_dqinfo,
2419         .get_dqblk      = vfs_get_dqblk,
2420         .set_dqblk      = vfs_set_dqblk
2421 };
2422
2423 static ctl_table fs_dqstats_table[] = {
2424         {
2425                 .ctl_name       = FS_DQ_LOOKUPS,
2426                 .procname       = "lookups",
2427                 .data           = &dqstats.lookups,
2428                 .maxlen         = sizeof(int),
2429                 .mode           = 0444,
2430                 .proc_handler   = &proc_dointvec,
2431         },
2432         {
2433                 .ctl_name       = FS_DQ_DROPS,
2434                 .procname       = "drops",
2435                 .data           = &dqstats.drops,
2436                 .maxlen         = sizeof(int),
2437                 .mode           = 0444,
2438                 .proc_handler   = &proc_dointvec,
2439         },
2440         {
2441                 .ctl_name       = FS_DQ_READS,
2442                 .procname       = "reads",
2443                 .data           = &dqstats.reads,
2444                 .maxlen         = sizeof(int),
2445                 .mode           = 0444,
2446                 .proc_handler   = &proc_dointvec,
2447         },
2448         {
2449                 .ctl_name       = FS_DQ_WRITES,
2450                 .procname       = "writes",
2451                 .data           = &dqstats.writes,
2452                 .maxlen         = sizeof(int),
2453                 .mode           = 0444,
2454                 .proc_handler   = &proc_dointvec,
2455         },
2456         {
2457                 .ctl_name       = FS_DQ_CACHE_HITS,
2458                 .procname       = "cache_hits",
2459                 .data           = &dqstats.cache_hits,
2460                 .maxlen         = sizeof(int),
2461                 .mode           = 0444,
2462                 .proc_handler   = &proc_dointvec,
2463         },
2464         {
2465                 .ctl_name       = FS_DQ_ALLOCATED,
2466                 .procname       = "allocated_dquots",
2467                 .data           = &dqstats.allocated_dquots,
2468                 .maxlen         = sizeof(int),
2469                 .mode           = 0444,
2470                 .proc_handler   = &proc_dointvec,
2471         },
2472         {
2473                 .ctl_name       = FS_DQ_FREE,
2474                 .procname       = "free_dquots",
2475                 .data           = &dqstats.free_dquots,
2476                 .maxlen         = sizeof(int),
2477                 .mode           = 0444,
2478                 .proc_handler   = &proc_dointvec,
2479         },
2480         {
2481                 .ctl_name       = FS_DQ_SYNCS,
2482                 .procname       = "syncs",
2483                 .data           = &dqstats.syncs,
2484                 .maxlen         = sizeof(int),
2485                 .mode           = 0444,
2486                 .proc_handler   = &proc_dointvec,
2487         },
2488 #ifdef CONFIG_PRINT_QUOTA_WARNING
2489         {
2490                 .ctl_name       = FS_DQ_WARNINGS,
2491                 .procname       = "warnings",
2492                 .data           = &flag_print_warnings,
2493                 .maxlen         = sizeof(int),
2494                 .mode           = 0644,
2495                 .proc_handler   = &proc_dointvec,
2496         },
2497 #endif
2498         { .ctl_name = 0 },
2499 };
2500
2501 static ctl_table fs_table[] = {
2502         {
2503                 .ctl_name       = FS_DQSTATS,
2504                 .procname       = "quota",
2505                 .mode           = 0555,
2506                 .child          = fs_dqstats_table,
2507         },
2508         { .ctl_name = 0 },
2509 };
2510
2511 static ctl_table sys_table[] = {
2512         {
2513                 .ctl_name       = CTL_FS,
2514                 .procname       = "fs",
2515                 .mode           = 0555,
2516                 .child          = fs_table,
2517         },
2518         { .ctl_name = 0 },
2519 };
2520
2521 static int __init dquot_init(void)
2522 {
2523         int i;
2524         unsigned long nr_hash, order;
2525
2526         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2527
2528         register_sysctl_table(sys_table);
2529
2530         dquot_cachep = kmem_cache_create("dquot",
2531                         sizeof(struct dquot), sizeof(unsigned long) * 4,
2532                         (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2533                                 SLAB_MEM_SPREAD|SLAB_PANIC),
2534                         NULL);
2535
2536         order = 0;
2537         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2538         if (!dquot_hash)
2539                 panic("Cannot create dquot hash table");
2540
2541         /* Find power-of-two hlist_heads which can fit into allocation */
2542         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2543         dq_hash_bits = 0;
2544         do {
2545                 dq_hash_bits++;
2546         } while (nr_hash >> dq_hash_bits);
2547         dq_hash_bits--;
2548
2549         nr_hash = 1UL << dq_hash_bits;
2550         dq_hash_mask = nr_hash - 1;
2551         for (i = 0; i < nr_hash; i++)
2552                 INIT_HLIST_HEAD(dquot_hash + i);
2553
2554         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2555                         nr_hash, order, (PAGE_SIZE << order));
2556
2557         register_shrinker(&dqcache_shrinker);
2558
2559 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
2560         if (genl_register_family(&quota_genl_family) != 0)
2561                 printk(KERN_ERR "VFS: Failed to create quota netlink interface.\n");
2562 #endif
2563
2564         return 0;
2565 }
2566 module_init(dquot_init);