[PATCH] cpuset memory spread: slab cache filesystems
[linux-2.6.git] / fs / 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  * Version: $Id: dquot.c,v 6.3 1996/11/17 18:35:34 mvw Exp mvw $
13  * 
14  * Author:      Marco van Wieringen <mvw@planets.elm.net>
15  *
16  * Fixes:   Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
17  *
18  *              Revised list management to avoid races
19  *              -- Bill Hawes, <whawes@star.net>, 9/98
20  *
21  *              Fixed races in dquot_transfer(), dqget() and dquot_alloc_...().
22  *              As the consequence the locking was moved from dquot_decr_...(),
23  *              dquot_incr_...() to calling functions.
24  *              invalidate_dquots() now writes modified dquots.
25  *              Serialized quota_off() and quota_on() for mount point.
26  *              Fixed a few bugs in grow_dquots().
27  *              Fixed deadlock in write_dquot() - we no longer account quotas on
28  *              quota files
29  *              remove_dquot_ref() moved to inode.c - it now traverses through inodes
30  *              add_dquot_ref() restarts after blocking
31  *              Added check for bogus uid and fixed check for group in quotactl.
32  *              Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99
33  *
34  *              Used struct list_head instead of own list struct
35  *              Invalidation of referenced dquots is no longer possible
36  *              Improved free_dquots list management
37  *              Quota and i_blocks are now updated in one place to avoid races
38  *              Warnings are now delayed so we won't block in critical section
39  *              Write updated not to require dquot lock
40  *              Jan Kara, <jack@suse.cz>, 9/2000
41  *
42  *              Added dynamic quota structure allocation
43  *              Jan Kara <jack@suse.cz> 12/2000
44  *
45  *              Rewritten quota interface. Implemented new quota format and
46  *              formats registering.
47  *              Jan Kara, <jack@suse.cz>, 2001,2002
48  *
49  *              New SMP locking.
50  *              Jan Kara, <jack@suse.cz>, 10/2002
51  *
52  *              Added journalled quota support, fix lock inversion problems
53  *              Jan Kara, <jack@suse.cz>, 2003,2004
54  *
55  * (C) Copyright 1994 - 1997 Marco van Wieringen 
56  */
57
58 #include <linux/errno.h>
59 #include <linux/kernel.h>
60 #include <linux/fs.h>
61 #include <linux/mount.h>
62 #include <linux/mm.h>
63 #include <linux/time.h>
64 #include <linux/types.h>
65 #include <linux/string.h>
66 #include <linux/fcntl.h>
67 #include <linux/stat.h>
68 #include <linux/tty.h>
69 #include <linux/file.h>
70 #include <linux/slab.h>
71 #include <linux/sysctl.h>
72 #include <linux/smp_lock.h>
73 #include <linux/init.h>
74 #include <linux/module.h>
75 #include <linux/proc_fs.h>
76 #include <linux/security.h>
77 #include <linux/kmod.h>
78 #include <linux/namei.h>
79 #include <linux/buffer_head.h>
80 #include <linux/capability.h>
81 #include <linux/quotaops.h>
82
83 #include <asm/uaccess.h>
84
85 #define __DQUOT_PARANOIA
86
87 /*
88  * There are two quota SMP locks. dq_list_lock protects all lists with quotas
89  * and quota formats and also dqstats structure containing statistics about the
90  * lists. dq_data_lock protects data from dq_dqb and also mem_dqinfo structures
91  * and also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
92  * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
93  * in inode_add_bytes() and inode_sub_bytes().
94  *
95  * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock
96  *
97  * Note that some things (eg. sb pointer, type, id) doesn't change during
98  * the life of the dquot structure and so needn't to be protected by a lock
99  *
100  * Any operation working on dquots via inode pointers must hold dqptr_sem.  If
101  * operation is just reading pointers from inode (or not using them at all) the
102  * read lock is enough. If pointers are altered function must hold write lock
103  * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
104  * for altering the flag i_mutex is also needed).  If operation is holding
105  * reference to dquot in other way (e.g. quotactl ops) it must be guarded by
106  * dqonoff_mutex.
107  * This locking assures that:
108  *   a) update/access to dquot pointers in inode is serialized
109  *   b) everyone is guarded against invalidate_dquots()
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  * i_mutex on quota files is special (it's below dqio_mutex)
124  */
125
126 static DEFINE_SPINLOCK(dq_list_lock);
127 DEFINE_SPINLOCK(dq_data_lock);
128
129 static char *quotatypes[] = INITQFNAMES;
130 static struct quota_format_type *quota_formats; /* List of registered formats */
131 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
132
133 /* SLAB cache for dquot structures */
134 static kmem_cache_t *dquot_cachep;
135
136 int register_quota_format(struct quota_format_type *fmt)
137 {
138         spin_lock(&dq_list_lock);
139         fmt->qf_next = quota_formats;
140         quota_formats = fmt;
141         spin_unlock(&dq_list_lock);
142         return 0;
143 }
144
145 void unregister_quota_format(struct quota_format_type *fmt)
146 {
147         struct quota_format_type **actqf;
148
149         spin_lock(&dq_list_lock);
150         for (actqf = &quota_formats; *actqf && *actqf != fmt; actqf = &(*actqf)->qf_next);
151         if (*actqf)
152                 *actqf = (*actqf)->qf_next;
153         spin_unlock(&dq_list_lock);
154 }
155
156 static struct quota_format_type *find_quota_format(int id)
157 {
158         struct quota_format_type *actqf;
159
160         spin_lock(&dq_list_lock);
161         for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
162         if (!actqf || !try_module_get(actqf->qf_owner)) {
163                 int qm;
164
165                 spin_unlock(&dq_list_lock);
166                 
167                 for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++);
168                 if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name))
169                         return NULL;
170
171                 spin_lock(&dq_list_lock);
172                 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
173                 if (actqf && !try_module_get(actqf->qf_owner))
174                         actqf = NULL;
175         }
176         spin_unlock(&dq_list_lock);
177         return actqf;
178 }
179
180 static void put_quota_format(struct quota_format_type *fmt)
181 {
182         module_put(fmt->qf_owner);
183 }
184
185 /*
186  * Dquot List Management:
187  * The quota code uses three lists for dquot management: the inuse_list,
188  * free_dquots, and dquot_hash[] array. A single dquot structure may be
189  * on all three lists, depending on its current state.
190  *
191  * All dquots are placed to the end of inuse_list when first created, and this
192  * list is used for invalidate operation, which must look at every dquot.
193  *
194  * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
195  * and this list is searched whenever we need an available dquot.  Dquots are
196  * removed from the list as soon as they are used again, and
197  * dqstats.free_dquots gives the number of dquots on the list. When
198  * dquot is invalidated it's completely released from memory.
199  *
200  * Dquots with a specific identity (device, type and id) are placed on
201  * one of the dquot_hash[] hash chains. The provides an efficient search
202  * mechanism to locate a specific dquot.
203  */
204
205 static LIST_HEAD(inuse_list);
206 static LIST_HEAD(free_dquots);
207 static unsigned int dq_hash_bits, dq_hash_mask;
208 static struct hlist_head *dquot_hash;
209
210 struct dqstats dqstats;
211
212 static void dqput(struct dquot *dquot);
213
214 static inline unsigned int
215 hashfn(const struct super_block *sb, unsigned int id, int type)
216 {
217         unsigned long tmp;
218
219         tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
220         return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
221 }
222
223 /*
224  * Following list functions expect dq_list_lock to be held
225  */
226 static inline void insert_dquot_hash(struct dquot *dquot)
227 {
228         struct hlist_head *head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
229         hlist_add_head(&dquot->dq_hash, head);
230 }
231
232 static inline void remove_dquot_hash(struct dquot *dquot)
233 {
234         hlist_del_init(&dquot->dq_hash);
235 }
236
237 static inline struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, unsigned int id, int type)
238 {
239         struct hlist_node *node;
240         struct dquot *dquot;
241
242         hlist_for_each (node, dquot_hash+hashent) {
243                 dquot = hlist_entry(node, struct dquot, dq_hash);
244                 if (dquot->dq_sb == sb && dquot->dq_id == id && dquot->dq_type == type)
245                         return dquot;
246         }
247         return NODQUOT;
248 }
249
250 /* Add a dquot to the tail of the free list */
251 static inline void put_dquot_last(struct dquot *dquot)
252 {
253         list_add(&dquot->dq_free, free_dquots.prev);
254         dqstats.free_dquots++;
255 }
256
257 static inline void remove_free_dquot(struct dquot *dquot)
258 {
259         if (list_empty(&dquot->dq_free))
260                 return;
261         list_del_init(&dquot->dq_free);
262         dqstats.free_dquots--;
263 }
264
265 static inline void put_inuse(struct dquot *dquot)
266 {
267         /* We add to the back of inuse list so we don't have to restart
268          * when traversing this list and we block */
269         list_add(&dquot->dq_inuse, inuse_list.prev);
270         dqstats.allocated_dquots++;
271 }
272
273 static inline void remove_inuse(struct dquot *dquot)
274 {
275         dqstats.allocated_dquots--;
276         list_del(&dquot->dq_inuse);
277 }
278 /*
279  * End of list functions needing dq_list_lock
280  */
281
282 static void wait_on_dquot(struct dquot *dquot)
283 {
284         mutex_lock(&dquot->dq_lock);
285         mutex_unlock(&dquot->dq_lock);
286 }
287
288 #define mark_dquot_dirty(dquot) ((dquot)->dq_sb->dq_op->mark_dirty(dquot))
289
290 int dquot_mark_dquot_dirty(struct dquot *dquot)
291 {
292         spin_lock(&dq_list_lock);
293         if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
294                 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
295                                 info[dquot->dq_type].dqi_dirty_list);
296         spin_unlock(&dq_list_lock);
297         return 0;
298 }
299
300 /* This function needs dq_list_lock */
301 static inline int clear_dquot_dirty(struct dquot *dquot)
302 {
303         if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
304                 return 0;
305         list_del_init(&dquot->dq_dirty);
306         return 1;
307 }
308
309 void mark_info_dirty(struct super_block *sb, int type)
310 {
311         set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
312 }
313 EXPORT_SYMBOL(mark_info_dirty);
314
315 /*
316  *      Read dquot from disk and alloc space for it
317  */
318
319 int dquot_acquire(struct dquot *dquot)
320 {
321         int ret = 0, ret2 = 0;
322         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
323
324         mutex_lock(&dquot->dq_lock);
325         mutex_lock(&dqopt->dqio_mutex);
326         if (!test_bit(DQ_READ_B, &dquot->dq_flags))
327                 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
328         if (ret < 0)
329                 goto out_iolock;
330         set_bit(DQ_READ_B, &dquot->dq_flags);
331         /* Instantiate dquot if needed */
332         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
333                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
334                 /* Write the info if needed */
335                 if (info_dirty(&dqopt->info[dquot->dq_type]))
336                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
337                 if (ret < 0)
338                         goto out_iolock;
339                 if (ret2 < 0) {
340                         ret = ret2;
341                         goto out_iolock;
342                 }
343         }
344         set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
345 out_iolock:
346         mutex_unlock(&dqopt->dqio_mutex);
347         mutex_unlock(&dquot->dq_lock);
348         return ret;
349 }
350
351 /*
352  *      Write dquot to disk
353  */
354 int dquot_commit(struct dquot *dquot)
355 {
356         int ret = 0, ret2 = 0;
357         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
358
359         mutex_lock(&dqopt->dqio_mutex);
360         spin_lock(&dq_list_lock);
361         if (!clear_dquot_dirty(dquot)) {
362                 spin_unlock(&dq_list_lock);
363                 goto out_sem;
364         }
365         spin_unlock(&dq_list_lock);
366         /* Inactive dquot can be only if there was error during read/init
367          * => we have better not writing it */
368         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
369                 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
370                 if (info_dirty(&dqopt->info[dquot->dq_type]))
371                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
372                 if (ret >= 0)
373                         ret = ret2;
374         }
375 out_sem:
376         mutex_unlock(&dqopt->dqio_mutex);
377         return ret;
378 }
379
380 /*
381  *      Release dquot
382  */
383 int dquot_release(struct dquot *dquot)
384 {
385         int ret = 0, ret2 = 0;
386         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
387
388         mutex_lock(&dquot->dq_lock);
389         /* Check whether we are not racing with some other dqget() */
390         if (atomic_read(&dquot->dq_count) > 1)
391                 goto out_dqlock;
392         mutex_lock(&dqopt->dqio_mutex);
393         if (dqopt->ops[dquot->dq_type]->release_dqblk) {
394                 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
395                 /* Write the info */
396                 if (info_dirty(&dqopt->info[dquot->dq_type]))
397                         ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
398                 if (ret >= 0)
399                         ret = ret2;
400         }
401         clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
402         mutex_unlock(&dqopt->dqio_mutex);
403 out_dqlock:
404         mutex_unlock(&dquot->dq_lock);
405         return ret;
406 }
407
408 /* Invalidate all dquots on the list. Note that this function is called after
409  * quota is disabled and pointers from inodes removed so there cannot be new
410  * quota users. There can still be some users of quotas due to inodes being
411  * just deleted or pruned by prune_icache() (those are not attached to any
412  * list). We have to wait for such users.
413  */
414 static void invalidate_dquots(struct super_block *sb, int type)
415 {
416         struct dquot *dquot, *tmp;
417
418 restart:
419         spin_lock(&dq_list_lock);
420         list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
421                 if (dquot->dq_sb != sb)
422                         continue;
423                 if (dquot->dq_type != type)
424                         continue;
425                 /* Wait for dquot users */
426                 if (atomic_read(&dquot->dq_count)) {
427                         DEFINE_WAIT(wait);
428
429                         atomic_inc(&dquot->dq_count);
430                         prepare_to_wait(&dquot->dq_wait_unused, &wait,
431                                         TASK_UNINTERRUPTIBLE);
432                         spin_unlock(&dq_list_lock);
433                         /* Once dqput() wakes us up, we know it's time to free
434                          * the dquot.
435                          * IMPORTANT: we rely on the fact that there is always
436                          * at most one process waiting for dquot to free.
437                          * Otherwise dq_count would be > 1 and we would never
438                          * wake up.
439                          */
440                         if (atomic_read(&dquot->dq_count) > 1)
441                                 schedule();
442                         finish_wait(&dquot->dq_wait_unused, &wait);
443                         dqput(dquot);
444                         /* At this moment dquot() need not exist (it could be
445                          * reclaimed by prune_dqcache(). Hence we must
446                          * restart. */
447                         goto restart;
448                 }
449                 /*
450                  * Quota now has no users and it has been written on last
451                  * dqput()
452                  */
453                 remove_dquot_hash(dquot);
454                 remove_free_dquot(dquot);
455                 remove_inuse(dquot);
456                 kmem_cache_free(dquot_cachep, dquot);
457         }
458         spin_unlock(&dq_list_lock);
459 }
460
461 int vfs_quota_sync(struct super_block *sb, int type)
462 {
463         struct list_head *dirty;
464         struct dquot *dquot;
465         struct quota_info *dqopt = sb_dqopt(sb);
466         int cnt;
467
468         mutex_lock(&dqopt->dqonoff_mutex);
469         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
470                 if (type != -1 && cnt != type)
471                         continue;
472                 if (!sb_has_quota_enabled(sb, cnt))
473                         continue;
474                 spin_lock(&dq_list_lock);
475                 dirty = &dqopt->info[cnt].dqi_dirty_list;
476                 while (!list_empty(dirty)) {
477                         dquot = list_entry(dirty->next, struct dquot, dq_dirty);
478                         /* Dirty and inactive can be only bad dquot... */
479                         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
480                                 clear_dquot_dirty(dquot);
481                                 continue;
482                         }
483                         /* Now we have active dquot from which someone is
484                          * holding reference so we can safely just increase
485                          * use count */
486                         atomic_inc(&dquot->dq_count);
487                         dqstats.lookups++;
488                         spin_unlock(&dq_list_lock);
489                         sb->dq_op->write_dquot(dquot);
490                         dqput(dquot);
491                         spin_lock(&dq_list_lock);
492                 }
493                 spin_unlock(&dq_list_lock);
494         }
495
496         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
497                 if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt)
498                         && info_dirty(&dqopt->info[cnt]))
499                         sb->dq_op->write_info(sb, cnt);
500         spin_lock(&dq_list_lock);
501         dqstats.syncs++;
502         spin_unlock(&dq_list_lock);
503         mutex_unlock(&dqopt->dqonoff_mutex);
504
505         return 0;
506 }
507
508 /* Free unused dquots from cache */
509 static void prune_dqcache(int count)
510 {
511         struct list_head *head;
512         struct dquot *dquot;
513
514         head = free_dquots.prev;
515         while (head != &free_dquots && count) {
516                 dquot = list_entry(head, struct dquot, dq_free);
517                 remove_dquot_hash(dquot);
518                 remove_free_dquot(dquot);
519                 remove_inuse(dquot);
520                 kmem_cache_free(dquot_cachep, dquot);
521                 count--;
522                 head = free_dquots.prev;
523         }
524 }
525
526 /*
527  * This is called from kswapd when we think we need some
528  * more memory
529  */
530
531 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
532 {
533         if (nr) {
534                 spin_lock(&dq_list_lock);
535                 prune_dqcache(nr);
536                 spin_unlock(&dq_list_lock);
537         }
538         return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
539 }
540
541 /*
542  * Put reference to dquot
543  * NOTE: If you change this function please check whether dqput_blocks() works right...
544  * MUST be called with either dqptr_sem or dqonoff_mutex held
545  */
546 static void dqput(struct dquot *dquot)
547 {
548         if (!dquot)
549                 return;
550 #ifdef __DQUOT_PARANOIA
551         if (!atomic_read(&dquot->dq_count)) {
552                 printk("VFS: dqput: trying to free free dquot\n");
553                 printk("VFS: device %s, dquot of %s %d\n",
554                         dquot->dq_sb->s_id,
555                         quotatypes[dquot->dq_type],
556                         dquot->dq_id);
557                 BUG();
558         }
559 #endif
560         
561         spin_lock(&dq_list_lock);
562         dqstats.drops++;
563         spin_unlock(&dq_list_lock);
564 we_slept:
565         spin_lock(&dq_list_lock);
566         if (atomic_read(&dquot->dq_count) > 1) {
567                 /* We have more than one user... nothing to do */
568                 atomic_dec(&dquot->dq_count);
569                 /* Releasing dquot during quotaoff phase? */
570                 if (!sb_has_quota_enabled(dquot->dq_sb, dquot->dq_type) &&
571                     atomic_read(&dquot->dq_count) == 1)
572                         wake_up(&dquot->dq_wait_unused);
573                 spin_unlock(&dq_list_lock);
574                 return;
575         }
576         /* Need to release dquot? */
577         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
578                 spin_unlock(&dq_list_lock);
579                 /* Commit dquot before releasing */
580                 dquot->dq_sb->dq_op->write_dquot(dquot);
581                 goto we_slept;
582         }
583         /* Clear flag in case dquot was inactive (something bad happened) */
584         clear_dquot_dirty(dquot);
585         if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
586                 spin_unlock(&dq_list_lock);
587                 dquot->dq_sb->dq_op->release_dquot(dquot);
588                 goto we_slept;
589         }
590         atomic_dec(&dquot->dq_count);
591 #ifdef __DQUOT_PARANOIA
592         /* sanity check */
593         if (!list_empty(&dquot->dq_free))
594                 BUG();
595 #endif
596         put_dquot_last(dquot);
597         spin_unlock(&dq_list_lock);
598 }
599
600 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
601 {
602         struct dquot *dquot;
603
604         dquot = kmem_cache_alloc(dquot_cachep, SLAB_NOFS);
605         if(!dquot)
606                 return NODQUOT;
607
608         memset((caddr_t)dquot, 0, sizeof(struct dquot));
609         mutex_init(&dquot->dq_lock);
610         INIT_LIST_HEAD(&dquot->dq_free);
611         INIT_LIST_HEAD(&dquot->dq_inuse);
612         INIT_HLIST_NODE(&dquot->dq_hash);
613         INIT_LIST_HEAD(&dquot->dq_dirty);
614         init_waitqueue_head(&dquot->dq_wait_unused);
615         dquot->dq_sb = sb;
616         dquot->dq_type = type;
617         atomic_set(&dquot->dq_count, 1);
618
619         return dquot;
620 }
621
622 /*
623  * Get reference to dquot
624  * MUST be called with either dqptr_sem or dqonoff_mutex held
625  */
626 static struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
627 {
628         unsigned int hashent = hashfn(sb, id, type);
629         struct dquot *dquot, *empty = NODQUOT;
630
631         if (!sb_has_quota_enabled(sb, type))
632                 return NODQUOT;
633 we_slept:
634         spin_lock(&dq_list_lock);
635         if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) {
636                 if (empty == NODQUOT) {
637                         spin_unlock(&dq_list_lock);
638                         if ((empty = get_empty_dquot(sb, type)) == NODQUOT)
639                                 schedule();     /* Try to wait for a moment... */
640                         goto we_slept;
641                 }
642                 dquot = empty;
643                 dquot->dq_id = id;
644                 /* all dquots go on the inuse_list */
645                 put_inuse(dquot);
646                 /* hash it first so it can be found */
647                 insert_dquot_hash(dquot);
648                 dqstats.lookups++;
649                 spin_unlock(&dq_list_lock);
650         } else {
651                 if (!atomic_read(&dquot->dq_count))
652                         remove_free_dquot(dquot);
653                 atomic_inc(&dquot->dq_count);
654                 dqstats.cache_hits++;
655                 dqstats.lookups++;
656                 spin_unlock(&dq_list_lock);
657                 if (empty)
658                         kmem_cache_free(dquot_cachep, empty);
659         }
660         /* Wait for dq_lock - after this we know that either dquot_release() is already
661          * finished or it will be canceled due to dq_count > 1 test */
662         wait_on_dquot(dquot);
663         /* Read the dquot and instantiate it (everything done only if needed) */
664         if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
665                 dqput(dquot);
666                 return NODQUOT;
667         }
668 #ifdef __DQUOT_PARANOIA
669         if (!dquot->dq_sb)      /* Has somebody invalidated entry under us? */
670                 BUG();
671 #endif
672
673         return dquot;
674 }
675
676 static int dqinit_needed(struct inode *inode, int type)
677 {
678         int cnt;
679
680         if (IS_NOQUOTA(inode))
681                 return 0;
682         if (type != -1)
683                 return inode->i_dquot[type] == NODQUOT;
684         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
685                 if (inode->i_dquot[cnt] == NODQUOT)
686                         return 1;
687         return 0;
688 }
689
690 /* This routine is guarded by dqonoff_mutex mutex */
691 static void add_dquot_ref(struct super_block *sb, int type)
692 {
693         struct list_head *p;
694
695 restart:
696         file_list_lock();
697         list_for_each(p, &sb->s_files) {
698                 struct file *filp = list_entry(p, struct file, f_u.fu_list);
699                 struct inode *inode = filp->f_dentry->d_inode;
700                 if (filp->f_mode & FMODE_WRITE && dqinit_needed(inode, type)) {
701                         struct dentry *dentry = dget(filp->f_dentry);
702                         file_list_unlock();
703                         sb->dq_op->initialize(inode, type);
704                         dput(dentry);
705                         /* As we may have blocked we had better restart... */
706                         goto restart;
707                 }
708         }
709         file_list_unlock();
710 }
711
712 /* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */
713 static inline int dqput_blocks(struct dquot *dquot)
714 {
715         if (atomic_read(&dquot->dq_count) <= 1)
716                 return 1;
717         return 0;
718 }
719
720 /* Remove references to dquots from inode - add dquot to list for freeing if needed */
721 /* We can't race with anybody because we hold dqptr_sem for writing... */
722 int remove_inode_dquot_ref(struct inode *inode, int type, struct list_head *tofree_head)
723 {
724         struct dquot *dquot = inode->i_dquot[type];
725
726         inode->i_dquot[type] = NODQUOT;
727         if (dquot != NODQUOT) {
728                 if (dqput_blocks(dquot)) {
729 #ifdef __DQUOT_PARANOIA
730                         if (atomic_read(&dquot->dq_count) != 1)
731                                 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
732 #endif
733                         spin_lock(&dq_list_lock);
734                         list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */
735                         spin_unlock(&dq_list_lock);
736                         return 1;
737                 }
738                 else
739                         dqput(dquot);   /* We have guaranteed we won't block */
740         }
741         return 0;
742 }
743
744 /* Free list of dquots - called from inode.c */
745 /* dquots are removed from inodes, no new references can be got so we are the only ones holding reference */
746 static void put_dquot_list(struct list_head *tofree_head)
747 {
748         struct list_head *act_head;
749         struct dquot *dquot;
750
751         act_head = tofree_head->next;
752         /* So now we have dquots on the list... Just free them */
753         while (act_head != tofree_head) {
754                 dquot = list_entry(act_head, struct dquot, dq_free);
755                 act_head = act_head->next;
756                 list_del_init(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */
757                 dqput(dquot);
758         }
759 }
760
761 /* Gather all references from inodes and drop them */
762 static void drop_dquot_ref(struct super_block *sb, int type)
763 {
764         LIST_HEAD(tofree_head);
765
766         down_write(&sb_dqopt(sb)->dqptr_sem);
767         remove_dquot_ref(sb, type, &tofree_head);
768         up_write(&sb_dqopt(sb)->dqptr_sem);
769         put_dquot_list(&tofree_head);
770 }
771
772 static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number)
773 {
774         dquot->dq_dqb.dqb_curinodes += number;
775 }
776
777 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
778 {
779         dquot->dq_dqb.dqb_curspace += number;
780 }
781
782 static inline void dquot_decr_inodes(struct dquot *dquot, unsigned long number)
783 {
784         if (dquot->dq_dqb.dqb_curinodes > number)
785                 dquot->dq_dqb.dqb_curinodes -= number;
786         else
787                 dquot->dq_dqb.dqb_curinodes = 0;
788         if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
789                 dquot->dq_dqb.dqb_itime = (time_t) 0;
790         clear_bit(DQ_INODES_B, &dquot->dq_flags);
791 }
792
793 static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
794 {
795         if (dquot->dq_dqb.dqb_curspace > number)
796                 dquot->dq_dqb.dqb_curspace -= number;
797         else
798                 dquot->dq_dqb.dqb_curspace = 0;
799         if (toqb(dquot->dq_dqb.dqb_curspace) <= dquot->dq_dqb.dqb_bsoftlimit)
800                 dquot->dq_dqb.dqb_btime = (time_t) 0;
801         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
802 }
803
804 static int flag_print_warnings = 1;
805
806 static inline int need_print_warning(struct dquot *dquot)
807 {
808         if (!flag_print_warnings)
809                 return 0;
810
811         switch (dquot->dq_type) {
812                 case USRQUOTA:
813                         return current->fsuid == dquot->dq_id;
814                 case GRPQUOTA:
815                         return in_group_p(dquot->dq_id);
816         }
817         return 0;
818 }
819
820 /* Values of warnings */
821 #define NOWARN 0
822 #define IHARDWARN 1
823 #define ISOFTLONGWARN 2
824 #define ISOFTWARN 3
825 #define BHARDWARN 4
826 #define BSOFTLONGWARN 5
827 #define BSOFTWARN 6
828
829 /* Print warning to user which exceeded quota */
830 static void print_warning(struct dquot *dquot, const char warntype)
831 {
832         char *msg = NULL;
833         int flag = (warntype == BHARDWARN || warntype == BSOFTLONGWARN) ? DQ_BLKS_B :
834           ((warntype == IHARDWARN || warntype == ISOFTLONGWARN) ? DQ_INODES_B : 0);
835
836         if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags)))
837                 return;
838
839         tty_write_message(current->signal->tty, dquot->dq_sb->s_id);
840         if (warntype == ISOFTWARN || warntype == BSOFTWARN)
841                 tty_write_message(current->signal->tty, ": warning, ");
842         else
843                 tty_write_message(current->signal->tty, ": write failed, ");
844         tty_write_message(current->signal->tty, quotatypes[dquot->dq_type]);
845         switch (warntype) {
846                 case IHARDWARN:
847                         msg = " file limit reached.\r\n";
848                         break;
849                 case ISOFTLONGWARN:
850                         msg = " file quota exceeded too long.\r\n";
851                         break;
852                 case ISOFTWARN:
853                         msg = " file quota exceeded.\r\n";
854                         break;
855                 case BHARDWARN:
856                         msg = " block limit reached.\r\n";
857                         break;
858                 case BSOFTLONGWARN:
859                         msg = " block quota exceeded too long.\r\n";
860                         break;
861                 case BSOFTWARN:
862                         msg = " block quota exceeded.\r\n";
863                         break;
864         }
865         tty_write_message(current->signal->tty, msg);
866 }
867
868 static inline void flush_warnings(struct dquot **dquots, char *warntype)
869 {
870         int i;
871
872         for (i = 0; i < MAXQUOTAS; i++)
873                 if (dquots[i] != NODQUOT && warntype[i] != NOWARN)
874                         print_warning(dquots[i], warntype[i]);
875 }
876
877 static inline char ignore_hardlimit(struct dquot *dquot)
878 {
879         struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
880
881         return capable(CAP_SYS_RESOURCE) &&
882             (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & V1_DQF_RSQUASH));
883 }
884
885 /* needs dq_data_lock */
886 static int check_idq(struct dquot *dquot, ulong inodes, char *warntype)
887 {
888         *warntype = NOWARN;
889         if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
890                 return QUOTA_OK;
891
892         if (dquot->dq_dqb.dqb_ihardlimit &&
893            (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit &&
894             !ignore_hardlimit(dquot)) {
895                 *warntype = IHARDWARN;
896                 return NO_QUOTA;
897         }
898
899         if (dquot->dq_dqb.dqb_isoftlimit &&
900            (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
901             dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime &&
902             !ignore_hardlimit(dquot)) {
903                 *warntype = ISOFTLONGWARN;
904                 return NO_QUOTA;
905         }
906
907         if (dquot->dq_dqb.dqb_isoftlimit &&
908            (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
909             dquot->dq_dqb.dqb_itime == 0) {
910                 *warntype = ISOFTWARN;
911                 dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
912         }
913
914         return QUOTA_OK;
915 }
916
917 /* needs dq_data_lock */
918 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
919 {
920         *warntype = 0;
921         if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
922                 return QUOTA_OK;
923
924         if (dquot->dq_dqb.dqb_bhardlimit &&
925            toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bhardlimit &&
926             !ignore_hardlimit(dquot)) {
927                 if (!prealloc)
928                         *warntype = BHARDWARN;
929                 return NO_QUOTA;
930         }
931
932         if (dquot->dq_dqb.dqb_bsoftlimit &&
933            toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
934             dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime &&
935             !ignore_hardlimit(dquot)) {
936                 if (!prealloc)
937                         *warntype = BSOFTLONGWARN;
938                 return NO_QUOTA;
939         }
940
941         if (dquot->dq_dqb.dqb_bsoftlimit &&
942            toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
943             dquot->dq_dqb.dqb_btime == 0) {
944                 if (!prealloc) {
945                         *warntype = BSOFTWARN;
946                         dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
947                 }
948                 else
949                         /*
950                          * We don't allow preallocation to exceed softlimit so exceeding will
951                          * be always printed
952                          */
953                         return NO_QUOTA;
954         }
955
956         return QUOTA_OK;
957 }
958
959 /*
960  *      Initialize quota pointers in inode
961  *      Transaction must be started at entry
962  */
963 int dquot_initialize(struct inode *inode, int type)
964 {
965         unsigned int id = 0;
966         int cnt, ret = 0;
967
968         /* First test before acquiring mutex - solves deadlocks when we
969          * re-enter the quota code and are already holding the mutex */
970         if (IS_NOQUOTA(inode))
971                 return 0;
972         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
973         /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
974         if (IS_NOQUOTA(inode))
975                 goto out_err;
976         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
977                 if (type != -1 && cnt != type)
978                         continue;
979                 if (inode->i_dquot[cnt] == NODQUOT) {
980                         switch (cnt) {
981                                 case USRQUOTA:
982                                         id = inode->i_uid;
983                                         break;
984                                 case GRPQUOTA:
985                                         id = inode->i_gid;
986                                         break;
987                         }
988                         inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt);
989                 }
990         }
991 out_err:
992         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
993         return ret;
994 }
995
996 /*
997  *      Release all quotas referenced by inode
998  *      Transaction must be started at an entry
999  */
1000 int dquot_drop(struct inode *inode)
1001 {
1002         int cnt;
1003
1004         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1005         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1006                 if (inode->i_dquot[cnt] != NODQUOT) {
1007                         dqput(inode->i_dquot[cnt]);
1008                         inode->i_dquot[cnt] = NODQUOT;
1009                 }
1010         }
1011         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1012         return 0;
1013 }
1014
1015 /*
1016  * Following four functions update i_blocks+i_bytes fields and
1017  * quota information (together with appropriate checks)
1018  * NOTE: We absolutely rely on the fact that caller dirties
1019  * the inode (usually macros in quotaops.h care about this) and
1020  * holds a handle for the current transaction so that dquot write and
1021  * inode write go into the same transaction.
1022  */
1023
1024 /*
1025  * This operation can block, but only after everything is updated
1026  */
1027 int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1028 {
1029         int cnt, ret = NO_QUOTA;
1030         char warntype[MAXQUOTAS];
1031
1032         /* First test before acquiring mutex - solves deadlocks when we
1033          * re-enter the quota code and are already holding the mutex */
1034         if (IS_NOQUOTA(inode)) {
1035 out_add:
1036                 inode_add_bytes(inode, number);
1037                 return QUOTA_OK;
1038         }
1039         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1040                 warntype[cnt] = NOWARN;
1041
1042         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1043         if (IS_NOQUOTA(inode)) {        /* Now we can do reliable test... */
1044                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1045                 goto out_add;
1046         }
1047         spin_lock(&dq_data_lock);
1048         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1049                 if (inode->i_dquot[cnt] == NODQUOT)
1050                         continue;
1051                 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA)
1052                         goto warn_put_all;
1053         }
1054         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1055                 if (inode->i_dquot[cnt] == NODQUOT)
1056                         continue;
1057                 dquot_incr_space(inode->i_dquot[cnt], number);
1058         }
1059         inode_add_bytes(inode, number);
1060         ret = QUOTA_OK;
1061 warn_put_all:
1062         spin_unlock(&dq_data_lock);
1063         if (ret == QUOTA_OK)
1064                 /* Dirtify all the dquots - this can block when journalling */
1065                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1066                         if (inode->i_dquot[cnt])
1067                                 mark_dquot_dirty(inode->i_dquot[cnt]);
1068         flush_warnings(inode->i_dquot, warntype);
1069         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1070         return ret;
1071 }
1072
1073 /*
1074  * This operation can block, but only after everything is updated
1075  */
1076 int dquot_alloc_inode(const struct inode *inode, unsigned long number)
1077 {
1078         int cnt, ret = NO_QUOTA;
1079         char warntype[MAXQUOTAS];
1080
1081         /* First test before acquiring mutex - solves deadlocks when we
1082          * re-enter the quota code and are already holding the mutex */
1083         if (IS_NOQUOTA(inode))
1084                 return QUOTA_OK;
1085         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1086                 warntype[cnt] = NOWARN;
1087         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1088         if (IS_NOQUOTA(inode)) {
1089                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1090                 return QUOTA_OK;
1091         }
1092         spin_lock(&dq_data_lock);
1093         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1094                 if (inode->i_dquot[cnt] == NODQUOT)
1095                         continue;
1096                 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA)
1097                         goto warn_put_all;
1098         }
1099
1100         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1101                 if (inode->i_dquot[cnt] == NODQUOT)
1102                         continue;
1103                 dquot_incr_inodes(inode->i_dquot[cnt], number);
1104         }
1105         ret = QUOTA_OK;
1106 warn_put_all:
1107         spin_unlock(&dq_data_lock);
1108         if (ret == QUOTA_OK)
1109                 /* Dirtify all the dquots - this can block when journalling */
1110                 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1111                         if (inode->i_dquot[cnt])
1112                                 mark_dquot_dirty(inode->i_dquot[cnt]);
1113         flush_warnings((struct dquot **)inode->i_dquot, warntype);
1114         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1115         return ret;
1116 }
1117
1118 /*
1119  * This operation can block, but only after everything is updated
1120  */
1121 int dquot_free_space(struct inode *inode, qsize_t number)
1122 {
1123         unsigned int cnt;
1124
1125         /* First test before acquiring mutex - solves deadlocks when we
1126          * re-enter the quota code and are already holding the mutex */
1127         if (IS_NOQUOTA(inode)) {
1128 out_sub:
1129                 inode_sub_bytes(inode, number);
1130                 return QUOTA_OK;
1131         }
1132         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1133         /* Now recheck reliably when holding dqptr_sem */
1134         if (IS_NOQUOTA(inode)) {
1135                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1136                 goto out_sub;
1137         }
1138         spin_lock(&dq_data_lock);
1139         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1140                 if (inode->i_dquot[cnt] == NODQUOT)
1141                         continue;
1142                 dquot_decr_space(inode->i_dquot[cnt], number);
1143         }
1144         inode_sub_bytes(inode, number);
1145         spin_unlock(&dq_data_lock);
1146         /* Dirtify all the dquots - this can block when journalling */
1147         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1148                 if (inode->i_dquot[cnt])
1149                         mark_dquot_dirty(inode->i_dquot[cnt]);
1150         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1151         return QUOTA_OK;
1152 }
1153
1154 /*
1155  * This operation can block, but only after everything is updated
1156  */
1157 int dquot_free_inode(const struct inode *inode, unsigned long number)
1158 {
1159         unsigned int cnt;
1160
1161         /* First test before acquiring mutex - solves deadlocks when we
1162          * re-enter the quota code and are already holding the mutex */
1163         if (IS_NOQUOTA(inode))
1164                 return QUOTA_OK;
1165         down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1166         /* Now recheck reliably when holding dqptr_sem */
1167         if (IS_NOQUOTA(inode)) {
1168                 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1169                 return QUOTA_OK;
1170         }
1171         spin_lock(&dq_data_lock);
1172         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1173                 if (inode->i_dquot[cnt] == NODQUOT)
1174                         continue;
1175                 dquot_decr_inodes(inode->i_dquot[cnt], number);
1176         }
1177         spin_unlock(&dq_data_lock);
1178         /* Dirtify all the dquots - this can block when journalling */
1179         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1180                 if (inode->i_dquot[cnt])
1181                         mark_dquot_dirty(inode->i_dquot[cnt]);
1182         up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1183         return QUOTA_OK;
1184 }
1185
1186 /*
1187  * Transfer the number of inode and blocks from one diskquota to an other.
1188  *
1189  * This operation can block, but only after everything is updated
1190  * A transaction must be started when entering this function.
1191  */
1192 int dquot_transfer(struct inode *inode, struct iattr *iattr)
1193 {
1194         qsize_t space;
1195         struct dquot *transfer_from[MAXQUOTAS];
1196         struct dquot *transfer_to[MAXQUOTAS];
1197         int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid,
1198             chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid;
1199         char warntype[MAXQUOTAS];
1200
1201         /* First test before acquiring mutex - solves deadlocks when we
1202          * re-enter the quota code and are already holding the mutex */
1203         if (IS_NOQUOTA(inode))
1204                 return QUOTA_OK;
1205         /* Clear the arrays */
1206         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1207                 transfer_to[cnt] = transfer_from[cnt] = NODQUOT;
1208                 warntype[cnt] = NOWARN;
1209         }
1210         down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1211         /* Now recheck reliably when holding dqptr_sem */
1212         if (IS_NOQUOTA(inode)) {        /* File without quota accounting? */
1213                 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1214                 return QUOTA_OK;
1215         }
1216         /* First build the transfer_to list - here we can block on
1217          * reading/instantiating of dquots.  We know that the transaction for
1218          * us was already started so we don't violate lock ranking here */
1219         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1220                 switch (cnt) {
1221                         case USRQUOTA:
1222                                 if (!chuid)
1223                                         continue;
1224                                 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt);
1225                                 break;
1226                         case GRPQUOTA:
1227                                 if (!chgid)
1228                                         continue;
1229                                 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt);
1230                                 break;
1231                 }
1232         }
1233         spin_lock(&dq_data_lock);
1234         space = inode_get_bytes(inode);
1235         /* Build the transfer_from list and check the limits */
1236         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1237                 if (transfer_to[cnt] == NODQUOT)
1238                         continue;
1239                 transfer_from[cnt] = inode->i_dquot[cnt];
1240                 if (check_idq(transfer_to[cnt], 1, warntype+cnt) == NO_QUOTA ||
1241                     check_bdq(transfer_to[cnt], space, 0, warntype+cnt) == NO_QUOTA)
1242                         goto warn_put_all;
1243         }
1244
1245         /*
1246          * Finally perform the needed transfer from transfer_from to transfer_to
1247          */
1248         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1249                 /*
1250                  * Skip changes for same uid or gid or for turned off quota-type.
1251                  */
1252                 if (transfer_to[cnt] == NODQUOT)
1253                         continue;
1254
1255                 /* Due to IO error we might not have transfer_from[] structure */
1256                 if (transfer_from[cnt]) {
1257                         dquot_decr_inodes(transfer_from[cnt], 1);
1258                         dquot_decr_space(transfer_from[cnt], space);
1259                 }
1260
1261                 dquot_incr_inodes(transfer_to[cnt], 1);
1262                 dquot_incr_space(transfer_to[cnt], space);
1263
1264                 inode->i_dquot[cnt] = transfer_to[cnt];
1265         }
1266         ret = QUOTA_OK;
1267 warn_put_all:
1268         spin_unlock(&dq_data_lock);
1269         /* Dirtify all the dquots - this can block when journalling */
1270         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1271                 if (transfer_from[cnt])
1272                         mark_dquot_dirty(transfer_from[cnt]);
1273                 if (transfer_to[cnt])
1274                         mark_dquot_dirty(transfer_to[cnt]);
1275         }
1276         flush_warnings(transfer_to, warntype);
1277         
1278         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1279                 if (ret == QUOTA_OK && transfer_from[cnt] != NODQUOT)
1280                         dqput(transfer_from[cnt]);
1281                 if (ret == NO_QUOTA && transfer_to[cnt] != NODQUOT)
1282                         dqput(transfer_to[cnt]);
1283         }
1284         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1285         return ret;
1286 }
1287
1288 /*
1289  * Write info of quota file to disk
1290  */
1291 int dquot_commit_info(struct super_block *sb, int type)
1292 {
1293         int ret;
1294         struct quota_info *dqopt = sb_dqopt(sb);
1295
1296         mutex_lock(&dqopt->dqio_mutex);
1297         ret = dqopt->ops[type]->write_file_info(sb, type);
1298         mutex_unlock(&dqopt->dqio_mutex);
1299         return ret;
1300 }
1301
1302 /*
1303  * Definitions of diskquota operations.
1304  */
1305 struct dquot_operations dquot_operations = {
1306         .initialize     = dquot_initialize,
1307         .drop           = dquot_drop,
1308         .alloc_space    = dquot_alloc_space,
1309         .alloc_inode    = dquot_alloc_inode,
1310         .free_space     = dquot_free_space,
1311         .free_inode     = dquot_free_inode,
1312         .transfer       = dquot_transfer,
1313         .write_dquot    = dquot_commit,
1314         .acquire_dquot  = dquot_acquire,
1315         .release_dquot  = dquot_release,
1316         .mark_dirty     = dquot_mark_dquot_dirty,
1317         .write_info     = dquot_commit_info
1318 };
1319
1320 static inline void set_enable_flags(struct quota_info *dqopt, int type)
1321 {
1322         switch (type) {
1323                 case USRQUOTA:
1324                         dqopt->flags |= DQUOT_USR_ENABLED;
1325                         break;
1326                 case GRPQUOTA:
1327                         dqopt->flags |= DQUOT_GRP_ENABLED;
1328                         break;
1329         }
1330 }
1331
1332 static inline void reset_enable_flags(struct quota_info *dqopt, int type)
1333 {
1334         switch (type) {
1335                 case USRQUOTA:
1336                         dqopt->flags &= ~DQUOT_USR_ENABLED;
1337                         break;
1338                 case GRPQUOTA:
1339                         dqopt->flags &= ~DQUOT_GRP_ENABLED;
1340                         break;
1341         }
1342 }
1343
1344 /*
1345  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1346  */
1347 int vfs_quota_off(struct super_block *sb, int type)
1348 {
1349         int cnt;
1350         struct quota_info *dqopt = sb_dqopt(sb);
1351         struct inode *toputinode[MAXQUOTAS];
1352
1353         /* We need to serialize quota_off() for device */
1354         mutex_lock(&dqopt->dqonoff_mutex);
1355         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1356                 toputinode[cnt] = NULL;
1357                 if (type != -1 && cnt != type)
1358                         continue;
1359                 if (!sb_has_quota_enabled(sb, cnt))
1360                         continue;
1361                 reset_enable_flags(dqopt, cnt);
1362
1363                 /* Note: these are blocking operations */
1364                 drop_dquot_ref(sb, cnt);
1365                 invalidate_dquots(sb, cnt);
1366                 /*
1367                  * Now all dquots should be invalidated, all writes done so we should be only
1368                  * users of the info. No locks needed.
1369                  */
1370                 if (info_dirty(&dqopt->info[cnt]))
1371                         sb->dq_op->write_info(sb, cnt);
1372                 if (dqopt->ops[cnt]->free_file_info)
1373                         dqopt->ops[cnt]->free_file_info(sb, cnt);
1374                 put_quota_format(dqopt->info[cnt].dqi_format);
1375
1376                 toputinode[cnt] = dqopt->files[cnt];
1377                 dqopt->files[cnt] = NULL;
1378                 dqopt->info[cnt].dqi_flags = 0;
1379                 dqopt->info[cnt].dqi_igrace = 0;
1380                 dqopt->info[cnt].dqi_bgrace = 0;
1381                 dqopt->ops[cnt] = NULL;
1382         }
1383         mutex_unlock(&dqopt->dqonoff_mutex);
1384         /* Sync the superblock so that buffers with quota data are written to
1385          * disk (and so userspace sees correct data afterwards). */
1386         if (sb->s_op->sync_fs)
1387                 sb->s_op->sync_fs(sb, 1);
1388         sync_blockdev(sb->s_bdev);
1389         /* Now the quota files are just ordinary files and we can set the
1390          * inode flags back. Moreover we discard the pagecache so that
1391          * userspace sees the writes we did bypassing the pagecache. We
1392          * must also discard the blockdev buffers so that we see the
1393          * changes done by userspace on the next quotaon() */
1394         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1395                 if (toputinode[cnt]) {
1396                         mutex_lock(&dqopt->dqonoff_mutex);
1397                         /* If quota was reenabled in the meantime, we have
1398                          * nothing to do */
1399                         if (!sb_has_quota_enabled(sb, cnt)) {
1400                                 mutex_lock(&toputinode[cnt]->i_mutex);
1401                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1402                                   S_NOATIME | S_NOQUOTA);
1403                                 truncate_inode_pages(&toputinode[cnt]->i_data, 0);
1404                                 mutex_unlock(&toputinode[cnt]->i_mutex);
1405                                 mark_inode_dirty(toputinode[cnt]);
1406                                 iput(toputinode[cnt]);
1407                         }
1408                         mutex_unlock(&dqopt->dqonoff_mutex);
1409                 }
1410         if (sb->s_bdev)
1411                 invalidate_bdev(sb->s_bdev, 0);
1412         return 0;
1413 }
1414
1415 /*
1416  *      Turn quotas on on a device
1417  */
1418
1419 /* Helper function when we already have the inode */
1420 static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
1421 {
1422         struct quota_format_type *fmt = find_quota_format(format_id);
1423         struct super_block *sb = inode->i_sb;
1424         struct quota_info *dqopt = sb_dqopt(sb);
1425         int error;
1426         int oldflags = -1;
1427
1428         if (!fmt)
1429                 return -ESRCH;
1430         if (!S_ISREG(inode->i_mode)) {
1431                 error = -EACCES;
1432                 goto out_fmt;
1433         }
1434         if (IS_RDONLY(inode)) {
1435                 error = -EROFS;
1436                 goto out_fmt;
1437         }
1438         if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
1439                 error = -EINVAL;
1440                 goto out_fmt;
1441         }
1442
1443         /* As we bypass the pagecache we must now flush the inode so that
1444          * we see all the changes from userspace... */
1445         write_inode_now(inode, 1);
1446         /* And now flush the block cache so that kernel sees the changes */
1447         invalidate_bdev(sb->s_bdev, 0);
1448         mutex_lock(&inode->i_mutex);
1449         mutex_lock(&dqopt->dqonoff_mutex);
1450         if (sb_has_quota_enabled(sb, type)) {
1451                 error = -EBUSY;
1452                 goto out_lock;
1453         }
1454         /* We don't want quota and atime on quota files (deadlocks possible)
1455          * Also nobody should write to the file - we use special IO operations
1456          * which ignore the immutable bit. */
1457         down_write(&dqopt->dqptr_sem);
1458         oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA);
1459         inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
1460         up_write(&dqopt->dqptr_sem);
1461         sb->dq_op->drop(inode);
1462
1463         error = -EIO;
1464         dqopt->files[type] = igrab(inode);
1465         if (!dqopt->files[type])
1466                 goto out_lock;
1467         error = -EINVAL;
1468         if (!fmt->qf_ops->check_quota_file(sb, type))
1469                 goto out_file_init;
1470
1471         dqopt->ops[type] = fmt->qf_ops;
1472         dqopt->info[type].dqi_format = fmt;
1473         INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
1474         mutex_lock(&dqopt->dqio_mutex);
1475         if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) {
1476                 mutex_unlock(&dqopt->dqio_mutex);
1477                 goto out_file_init;
1478         }
1479         mutex_unlock(&dqopt->dqio_mutex);
1480         mutex_unlock(&inode->i_mutex);
1481         set_enable_flags(dqopt, type);
1482
1483         add_dquot_ref(sb, type);
1484         mutex_unlock(&dqopt->dqonoff_mutex);
1485
1486         return 0;
1487
1488 out_file_init:
1489         dqopt->files[type] = NULL;
1490         iput(inode);
1491 out_lock:
1492         mutex_unlock(&dqopt->dqonoff_mutex);
1493         if (oldflags != -1) {
1494                 down_write(&dqopt->dqptr_sem);
1495                 /* Set the flags back (in the case of accidental quotaon()
1496                  * on a wrong file we don't want to mess up the flags) */
1497                 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
1498                 inode->i_flags |= oldflags;
1499                 up_write(&dqopt->dqptr_sem);
1500         }
1501         mutex_unlock(&inode->i_mutex);
1502 out_fmt:
1503         put_quota_format(fmt);
1504
1505         return error; 
1506 }
1507
1508 /* Actual function called from quotactl() */
1509 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path)
1510 {
1511         struct nameidata nd;
1512         int error;
1513
1514         error = path_lookup(path, LOOKUP_FOLLOW, &nd);
1515         if (error < 0)
1516                 return error;
1517         error = security_quota_on(nd.dentry);
1518         if (error)
1519                 goto out_path;
1520         /* Quota file not on the same filesystem? */
1521         if (nd.mnt->mnt_sb != sb)
1522                 error = -EXDEV;
1523         else
1524                 error = vfs_quota_on_inode(nd.dentry->d_inode, type, format_id);
1525 out_path:
1526         path_release(&nd);
1527         return error;
1528 }
1529
1530 /*
1531  * This function is used when filesystem needs to initialize quotas
1532  * during mount time.
1533  */
1534 int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
1535                 int format_id, int type)
1536 {
1537         struct dentry *dentry;
1538         int error;
1539
1540         dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
1541         if (IS_ERR(dentry))
1542                 return PTR_ERR(dentry);
1543
1544         if (!dentry->d_inode) {
1545                 error = -ENOENT;
1546                 goto out;
1547         }
1548
1549         error = security_quota_on(dentry);
1550         if (!error)
1551                 error = vfs_quota_on_inode(dentry->d_inode, type, format_id);
1552
1553 out:
1554         dput(dentry);
1555         return error;
1556 }
1557
1558 /* Generic routine for getting common part of quota structure */
1559 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
1560 {
1561         struct mem_dqblk *dm = &dquot->dq_dqb;
1562
1563         spin_lock(&dq_data_lock);
1564         di->dqb_bhardlimit = dm->dqb_bhardlimit;
1565         di->dqb_bsoftlimit = dm->dqb_bsoftlimit;
1566         di->dqb_curspace = dm->dqb_curspace;
1567         di->dqb_ihardlimit = dm->dqb_ihardlimit;
1568         di->dqb_isoftlimit = dm->dqb_isoftlimit;
1569         di->dqb_curinodes = dm->dqb_curinodes;
1570         di->dqb_btime = dm->dqb_btime;
1571         di->dqb_itime = dm->dqb_itime;
1572         di->dqb_valid = QIF_ALL;
1573         spin_unlock(&dq_data_lock);
1574 }
1575
1576 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
1577 {
1578         struct dquot *dquot;
1579
1580         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
1581         if (!(dquot = dqget(sb, id, type))) {
1582                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1583                 return -ESRCH;
1584         }
1585         do_get_dqblk(dquot, di);
1586         dqput(dquot);
1587         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1588         return 0;
1589 }
1590
1591 /* Generic routine for setting common part of quota structure */
1592 static void do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
1593 {
1594         struct mem_dqblk *dm = &dquot->dq_dqb;
1595         int check_blim = 0, check_ilim = 0;
1596
1597         spin_lock(&dq_data_lock);
1598         if (di->dqb_valid & QIF_SPACE) {
1599                 dm->dqb_curspace = di->dqb_curspace;
1600                 check_blim = 1;
1601         }
1602         if (di->dqb_valid & QIF_BLIMITS) {
1603                 dm->dqb_bsoftlimit = di->dqb_bsoftlimit;
1604                 dm->dqb_bhardlimit = di->dqb_bhardlimit;
1605                 check_blim = 1;
1606         }
1607         if (di->dqb_valid & QIF_INODES) {
1608                 dm->dqb_curinodes = di->dqb_curinodes;
1609                 check_ilim = 1;
1610         }
1611         if (di->dqb_valid & QIF_ILIMITS) {
1612                 dm->dqb_isoftlimit = di->dqb_isoftlimit;
1613                 dm->dqb_ihardlimit = di->dqb_ihardlimit;
1614                 check_ilim = 1;
1615         }
1616         if (di->dqb_valid & QIF_BTIME)
1617                 dm->dqb_btime = di->dqb_btime;
1618         if (di->dqb_valid & QIF_ITIME)
1619                 dm->dqb_itime = di->dqb_itime;
1620
1621         if (check_blim) {
1622                 if (!dm->dqb_bsoftlimit || toqb(dm->dqb_curspace) < dm->dqb_bsoftlimit) {
1623                         dm->dqb_btime = 0;
1624                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1625                 }
1626                 else if (!(di->dqb_valid & QIF_BTIME))  /* Set grace only if user hasn't provided his own... */
1627                         dm->dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
1628         }
1629         if (check_ilim) {
1630                 if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) {
1631                         dm->dqb_itime = 0;
1632                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
1633                 }
1634                 else if (!(di->dqb_valid & QIF_ITIME))  /* Set grace only if user hasn't provided his own... */
1635                         dm->dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1636         }
1637         if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit)
1638                 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
1639         else
1640                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
1641         spin_unlock(&dq_data_lock);
1642         mark_dquot_dirty(dquot);
1643 }
1644
1645 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
1646 {
1647         struct dquot *dquot;
1648
1649         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
1650         if (!(dquot = dqget(sb, id, type))) {
1651                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1652                 return -ESRCH;
1653         }
1654         do_set_dqblk(dquot, di);
1655         dqput(dquot);
1656         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1657         return 0;
1658 }
1659
1660 /* Generic routine for getting common part of quota file information */
1661 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
1662 {
1663         struct mem_dqinfo *mi;
1664   
1665         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
1666         if (!sb_has_quota_enabled(sb, type)) {
1667                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1668                 return -ESRCH;
1669         }
1670         mi = sb_dqopt(sb)->info + type;
1671         spin_lock(&dq_data_lock);
1672         ii->dqi_bgrace = mi->dqi_bgrace;
1673         ii->dqi_igrace = mi->dqi_igrace;
1674         ii->dqi_flags = mi->dqi_flags & DQF_MASK;
1675         ii->dqi_valid = IIF_ALL;
1676         spin_unlock(&dq_data_lock);
1677         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1678         return 0;
1679 }
1680
1681 /* Generic routine for setting common part of quota file information */
1682 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
1683 {
1684         struct mem_dqinfo *mi;
1685
1686         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
1687         if (!sb_has_quota_enabled(sb, type)) {
1688                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1689                 return -ESRCH;
1690         }
1691         mi = sb_dqopt(sb)->info + type;
1692         spin_lock(&dq_data_lock);
1693         if (ii->dqi_valid & IIF_BGRACE)
1694                 mi->dqi_bgrace = ii->dqi_bgrace;
1695         if (ii->dqi_valid & IIF_IGRACE)
1696                 mi->dqi_igrace = ii->dqi_igrace;
1697         if (ii->dqi_valid & IIF_FLAGS)
1698                 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | (ii->dqi_flags & DQF_MASK);
1699         spin_unlock(&dq_data_lock);
1700         mark_info_dirty(sb, type);
1701         /* Force write to disk */
1702         sb->dq_op->write_info(sb, type);
1703         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1704         return 0;
1705 }
1706
1707 struct quotactl_ops vfs_quotactl_ops = {
1708         .quota_on       = vfs_quota_on,
1709         .quota_off      = vfs_quota_off,
1710         .quota_sync     = vfs_quota_sync,
1711         .get_info       = vfs_get_dqinfo,
1712         .set_info       = vfs_set_dqinfo,
1713         .get_dqblk      = vfs_get_dqblk,
1714         .set_dqblk      = vfs_set_dqblk
1715 };
1716
1717 static ctl_table fs_dqstats_table[] = {
1718         {
1719                 .ctl_name       = FS_DQ_LOOKUPS,
1720                 .procname       = "lookups",
1721                 .data           = &dqstats.lookups,
1722                 .maxlen         = sizeof(int),
1723                 .mode           = 0444,
1724                 .proc_handler   = &proc_dointvec,
1725         },
1726         {
1727                 .ctl_name       = FS_DQ_DROPS,
1728                 .procname       = "drops",
1729                 .data           = &dqstats.drops,
1730                 .maxlen         = sizeof(int),
1731                 .mode           = 0444,
1732                 .proc_handler   = &proc_dointvec,
1733         },
1734         {
1735                 .ctl_name       = FS_DQ_READS,
1736                 .procname       = "reads",
1737                 .data           = &dqstats.reads,
1738                 .maxlen         = sizeof(int),
1739                 .mode           = 0444,
1740                 .proc_handler   = &proc_dointvec,
1741         },
1742         {
1743                 .ctl_name       = FS_DQ_WRITES,
1744                 .procname       = "writes",
1745                 .data           = &dqstats.writes,
1746                 .maxlen         = sizeof(int),
1747                 .mode           = 0444,
1748                 .proc_handler   = &proc_dointvec,
1749         },
1750         {
1751                 .ctl_name       = FS_DQ_CACHE_HITS,
1752                 .procname       = "cache_hits",
1753                 .data           = &dqstats.cache_hits,
1754                 .maxlen         = sizeof(int),
1755                 .mode           = 0444,
1756                 .proc_handler   = &proc_dointvec,
1757         },
1758         {
1759                 .ctl_name       = FS_DQ_ALLOCATED,
1760                 .procname       = "allocated_dquots",
1761                 .data           = &dqstats.allocated_dquots,
1762                 .maxlen         = sizeof(int),
1763                 .mode           = 0444,
1764                 .proc_handler   = &proc_dointvec,
1765         },
1766         {
1767                 .ctl_name       = FS_DQ_FREE,
1768                 .procname       = "free_dquots",
1769                 .data           = &dqstats.free_dquots,
1770                 .maxlen         = sizeof(int),
1771                 .mode           = 0444,
1772                 .proc_handler   = &proc_dointvec,
1773         },
1774         {
1775                 .ctl_name       = FS_DQ_SYNCS,
1776                 .procname       = "syncs",
1777                 .data           = &dqstats.syncs,
1778                 .maxlen         = sizeof(int),
1779                 .mode           = 0444,
1780                 .proc_handler   = &proc_dointvec,
1781         },
1782         {
1783                 .ctl_name       = FS_DQ_WARNINGS,
1784                 .procname       = "warnings",
1785                 .data           = &flag_print_warnings,
1786                 .maxlen         = sizeof(int),
1787                 .mode           = 0644,
1788                 .proc_handler   = &proc_dointvec,
1789         },
1790         { .ctl_name = 0 },
1791 };
1792
1793 static ctl_table fs_table[] = {
1794         {
1795                 .ctl_name       = FS_DQSTATS,
1796                 .procname       = "quota",
1797                 .mode           = 0555,
1798                 .child          = fs_dqstats_table,
1799         },
1800         { .ctl_name = 0 },
1801 };
1802
1803 static ctl_table sys_table[] = {
1804         {
1805                 .ctl_name       = CTL_FS,
1806                 .procname       = "fs",
1807                 .mode           = 0555,
1808                 .child          = fs_table,
1809         },
1810         { .ctl_name = 0 },
1811 };
1812
1813 static int __init dquot_init(void)
1814 {
1815         int i;
1816         unsigned long nr_hash, order;
1817
1818         printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
1819
1820         register_sysctl_table(sys_table, 0);
1821
1822         dquot_cachep = kmem_cache_create("dquot", 
1823                         sizeof(struct dquot), sizeof(unsigned long) * 4,
1824                         SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_PANIC,
1825                         NULL, NULL);
1826
1827         order = 0;
1828         dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
1829         if (!dquot_hash)
1830                 panic("Cannot create dquot hash table");
1831
1832         /* Find power-of-two hlist_heads which can fit into allocation */
1833         nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
1834         dq_hash_bits = 0;
1835         do {
1836                 dq_hash_bits++;
1837         } while (nr_hash >> dq_hash_bits);
1838         dq_hash_bits--;
1839
1840         nr_hash = 1UL << dq_hash_bits;
1841         dq_hash_mask = nr_hash - 1;
1842         for (i = 0; i < nr_hash; i++)
1843                 INIT_HLIST_HEAD(dquot_hash + i);
1844
1845         printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
1846                         nr_hash, order, (PAGE_SIZE << order));
1847
1848         set_shrinker(DEFAULT_SEEKS, shrink_dqcache_memory);
1849
1850         return 0;
1851 }
1852 module_init(dquot_init);
1853
1854 EXPORT_SYMBOL(register_quota_format);
1855 EXPORT_SYMBOL(unregister_quota_format);
1856 EXPORT_SYMBOL(dqstats);
1857 EXPORT_SYMBOL(dq_data_lock);
1858 EXPORT_SYMBOL(vfs_quota_on);
1859 EXPORT_SYMBOL(vfs_quota_on_mount);
1860 EXPORT_SYMBOL(vfs_quota_off);
1861 EXPORT_SYMBOL(vfs_quota_sync);
1862 EXPORT_SYMBOL(vfs_get_dqinfo);
1863 EXPORT_SYMBOL(vfs_set_dqinfo);
1864 EXPORT_SYMBOL(vfs_get_dqblk);
1865 EXPORT_SYMBOL(vfs_set_dqblk);
1866 EXPORT_SYMBOL(dquot_commit);
1867 EXPORT_SYMBOL(dquot_commit_info);
1868 EXPORT_SYMBOL(dquot_acquire);
1869 EXPORT_SYMBOL(dquot_release);
1870 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
1871 EXPORT_SYMBOL(dquot_initialize);
1872 EXPORT_SYMBOL(dquot_drop);
1873 EXPORT_SYMBOL(dquot_alloc_space);
1874 EXPORT_SYMBOL(dquot_alloc_inode);
1875 EXPORT_SYMBOL(dquot_free_space);
1876 EXPORT_SYMBOL(dquot_free_inode);
1877 EXPORT_SYMBOL(dquot_transfer);