blob: 343c036556190f88f5de0466eb5a7eabfd4be0ab [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
81#include <asm/uaccess.h>
82
83#define __DQUOT_PARANOIA
84
85/*
86 * There are two quota SMP locks. dq_list_lock protects all lists with quotas
87 * and quota formats and also dqstats structure containing statistics about the
88 * lists. dq_data_lock protects data from dq_dqb and also mem_dqinfo structures
89 * and also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
90 * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
91 * in inode_add_bytes() and inode_sub_bytes().
92 *
93 * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock
94 *
95 * Note that some things (eg. sb pointer, type, id) doesn't change during
96 * the life of the dquot structure and so needn't to be protected by a lock
97 *
98 * Any operation working on dquots via inode pointers must hold dqptr_sem. If
99 * operation is just reading pointers from inode (or not using them at all) the
100 * read lock is enough. If pointers are altered function must hold write lock
101 * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
102 * for altering the flag i_sem is also needed). If operation is holding
103 * reference to dquot in other way (e.g. quotactl ops) it must be guarded by
104 * dqonoff_sem.
105 * This locking assures that:
106 * a) update/access to dquot pointers in inode is serialized
107 * b) everyone is guarded against invalidate_dquots()
108 *
109 * Each dquot has its dq_lock semaphore. Locked dquots might not be referenced
110 * from inodes (dquot_alloc_space() and such don't check the dq_lock).
111 * Currently dquot is locked only when it is being read to memory (or space for
112 * it is being allocated) on the first dqget() and when it is being released on
113 * the last dqput(). The allocation and release oparations are serialized by
114 * the dq_lock and by checking the use count in dquot_release(). Write
115 * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
116 * spinlock to internal buffers before writing.
117 *
118 * Lock ordering (including related VFS locks) is the following:
119 * i_sem > dqonoff_sem > iprune_sem > journal_lock > dqptr_sem >
120 * > dquot->dq_lock > dqio_sem
121 * i_sem on quota files is special (it's below dqio_sem)
122 */
123
124static DEFINE_SPINLOCK(dq_list_lock);
125DEFINE_SPINLOCK(dq_data_lock);
126
127static char *quotatypes[] = INITQFNAMES;
128static struct quota_format_type *quota_formats; /* List of registered formats */
129static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
130
131/* SLAB cache for dquot structures */
132static kmem_cache_t *dquot_cachep;
133
134int register_quota_format(struct quota_format_type *fmt)
135{
136 spin_lock(&dq_list_lock);
137 fmt->qf_next = quota_formats;
138 quota_formats = fmt;
139 spin_unlock(&dq_list_lock);
140 return 0;
141}
142
143void unregister_quota_format(struct quota_format_type *fmt)
144{
145 struct quota_format_type **actqf;
146
147 spin_lock(&dq_list_lock);
148 for (actqf = &quota_formats; *actqf && *actqf != fmt; actqf = &(*actqf)->qf_next);
149 if (*actqf)
150 *actqf = (*actqf)->qf_next;
151 spin_unlock(&dq_list_lock);
152}
153
154static struct quota_format_type *find_quota_format(int id)
155{
156 struct quota_format_type *actqf;
157
158 spin_lock(&dq_list_lock);
159 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
160 if (!actqf || !try_module_get(actqf->qf_owner)) {
161 int qm;
162
163 spin_unlock(&dq_list_lock);
164
165 for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++);
166 if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name))
167 return NULL;
168
169 spin_lock(&dq_list_lock);
170 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
171 if (actqf && !try_module_get(actqf->qf_owner))
172 actqf = NULL;
173 }
174 spin_unlock(&dq_list_lock);
175 return actqf;
176}
177
178static void put_quota_format(struct quota_format_type *fmt)
179{
180 module_put(fmt->qf_owner);
181}
182
183/*
184 * Dquot List Management:
185 * The quota code uses three lists for dquot management: the inuse_list,
186 * free_dquots, and dquot_hash[] array. A single dquot structure may be
187 * on all three lists, depending on its current state.
188 *
189 * All dquots are placed to the end of inuse_list when first created, and this
190 * list is used for invalidate operation, which must look at every dquot.
191 *
192 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
193 * and this list is searched whenever we need an available dquot. Dquots are
194 * removed from the list as soon as they are used again, and
195 * dqstats.free_dquots gives the number of dquots on the list. When
196 * dquot is invalidated it's completely released from memory.
197 *
198 * Dquots with a specific identity (device, type and id) are placed on
199 * one of the dquot_hash[] hash chains. The provides an efficient search
200 * mechanism to locate a specific dquot.
201 */
202
203static LIST_HEAD(inuse_list);
204static LIST_HEAD(free_dquots);
205static unsigned int dq_hash_bits, dq_hash_mask;
206static struct hlist_head *dquot_hash;
207
208struct dqstats dqstats;
209
210static void dqput(struct dquot *dquot);
211
212static inline unsigned int
213hashfn(const struct super_block *sb, unsigned int id, int type)
214{
215 unsigned long tmp;
216
217 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
218 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
219}
220
221/*
222 * Following list functions expect dq_list_lock to be held
223 */
224static inline void insert_dquot_hash(struct dquot *dquot)
225{
226 struct hlist_head *head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
227 hlist_add_head(&dquot->dq_hash, head);
228}
229
230static inline void remove_dquot_hash(struct dquot *dquot)
231{
232 hlist_del_init(&dquot->dq_hash);
233}
234
235static inline struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, unsigned int id, int type)
236{
237 struct hlist_node *node;
238 struct dquot *dquot;
239
240 hlist_for_each (node, dquot_hash+hashent) {
241 dquot = hlist_entry(node, struct dquot, dq_hash);
242 if (dquot->dq_sb == sb && dquot->dq_id == id && dquot->dq_type == type)
243 return dquot;
244 }
245 return NODQUOT;
246}
247
248/* Add a dquot to the tail of the free list */
249static inline void put_dquot_last(struct dquot *dquot)
250{
251 list_add(&dquot->dq_free, free_dquots.prev);
252 dqstats.free_dquots++;
253}
254
255static inline void remove_free_dquot(struct dquot *dquot)
256{
257 if (list_empty(&dquot->dq_free))
258 return;
259 list_del_init(&dquot->dq_free);
260 dqstats.free_dquots--;
261}
262
263static inline void put_inuse(struct dquot *dquot)
264{
265 /* We add to the back of inuse list so we don't have to restart
266 * when traversing this list and we block */
267 list_add(&dquot->dq_inuse, inuse_list.prev);
268 dqstats.allocated_dquots++;
269}
270
271static inline void remove_inuse(struct dquot *dquot)
272{
273 dqstats.allocated_dquots--;
274 list_del(&dquot->dq_inuse);
275}
276/*
277 * End of list functions needing dq_list_lock
278 */
279
280static void wait_on_dquot(struct dquot *dquot)
281{
282 down(&dquot->dq_lock);
283 up(&dquot->dq_lock);
284}
285
286#define mark_dquot_dirty(dquot) ((dquot)->dq_sb->dq_op->mark_dirty(dquot))
287
288int dquot_mark_dquot_dirty(struct dquot *dquot)
289{
290 spin_lock(&dq_list_lock);
291 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
292 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
293 info[dquot->dq_type].dqi_dirty_list);
294 spin_unlock(&dq_list_lock);
295 return 0;
296}
297
298/* This function needs dq_list_lock */
299static inline int clear_dquot_dirty(struct dquot *dquot)
300{
301 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
302 return 0;
303 list_del_init(&dquot->dq_dirty);
304 return 1;
305}
306
307void mark_info_dirty(struct super_block *sb, int type)
308{
309 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
310}
311EXPORT_SYMBOL(mark_info_dirty);
312
313/*
314 * Read dquot from disk and alloc space for it
315 */
316
317int dquot_acquire(struct dquot *dquot)
318{
319 int ret = 0, ret2 = 0;
320 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
321
322 down(&dquot->dq_lock);
323 down(&dqopt->dqio_sem);
324 if (!test_bit(DQ_READ_B, &dquot->dq_flags))
325 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
326 if (ret < 0)
327 goto out_iolock;
328 set_bit(DQ_READ_B, &dquot->dq_flags);
329 /* Instantiate dquot if needed */
330 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
331 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
332 /* Write the info if needed */
333 if (info_dirty(&dqopt->info[dquot->dq_type]))
334 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
335 if (ret < 0)
336 goto out_iolock;
337 if (ret2 < 0) {
338 ret = ret2;
339 goto out_iolock;
340 }
341 }
342 set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
343out_iolock:
344 up(&dqopt->dqio_sem);
345 up(&dquot->dq_lock);
346 return ret;
347}
348
349/*
350 * Write dquot to disk
351 */
352int dquot_commit(struct dquot *dquot)
353{
354 int ret = 0, ret2 = 0;
355 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
356
357 down(&dqopt->dqio_sem);
358 spin_lock(&dq_list_lock);
359 if (!clear_dquot_dirty(dquot)) {
360 spin_unlock(&dq_list_lock);
361 goto out_sem;
362 }
363 spin_unlock(&dq_list_lock);
364 /* Inactive dquot can be only if there was error during read/init
365 * => we have better not writing it */
366 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
367 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
368 if (info_dirty(&dqopt->info[dquot->dq_type]))
369 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
370 if (ret >= 0)
371 ret = ret2;
372 }
373out_sem:
374 up(&dqopt->dqio_sem);
375 return ret;
376}
377
378/*
379 * Release dquot
380 */
381int dquot_release(struct dquot *dquot)
382{
383 int ret = 0, ret2 = 0;
384 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
385
386 down(&dquot->dq_lock);
387 /* Check whether we are not racing with some other dqget() */
388 if (atomic_read(&dquot->dq_count) > 1)
389 goto out_dqlock;
390 down(&dqopt->dqio_sem);
391 if (dqopt->ops[dquot->dq_type]->release_dqblk) {
392 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
393 /* Write the info */
394 if (info_dirty(&dqopt->info[dquot->dq_type]))
395 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
396 if (ret >= 0)
397 ret = ret2;
398 }
399 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
400 up(&dqopt->dqio_sem);
401out_dqlock:
402 up(&dquot->dq_lock);
403 return ret;
404}
405
406/* Invalidate all dquots on the list. Note that this function is called after
407 * quota is disabled and pointers from inodes removed so there cannot be new
408 * quota users. Also because we hold dqonoff_sem there can be no quota users
409 * for this sb+type at all. */
410static void invalidate_dquots(struct super_block *sb, int type)
411{
412 struct dquot *dquot;
413 struct list_head *head;
414
415 spin_lock(&dq_list_lock);
416 for (head = inuse_list.next; head != &inuse_list;) {
417 dquot = list_entry(head, struct dquot, dq_inuse);
418 head = head->next;
419 if (dquot->dq_sb != sb)
420 continue;
421 if (dquot->dq_type != type)
422 continue;
423#ifdef __DQUOT_PARANOIA
424 if (atomic_read(&dquot->dq_count))
425 BUG();
426#endif
427 /* Quota now has no users and it has been written on last dqput() */
428 remove_dquot_hash(dquot);
429 remove_free_dquot(dquot);
430 remove_inuse(dquot);
431 kmem_cache_free(dquot_cachep, dquot);
432 }
433 spin_unlock(&dq_list_lock);
434}
435
436int vfs_quota_sync(struct super_block *sb, int type)
437{
438 struct list_head *dirty;
439 struct dquot *dquot;
440 struct quota_info *dqopt = sb_dqopt(sb);
441 int cnt;
442
443 down(&dqopt->dqonoff_sem);
444 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
445 if (type != -1 && cnt != type)
446 continue;
447 if (!sb_has_quota_enabled(sb, cnt))
448 continue;
449 spin_lock(&dq_list_lock);
450 dirty = &dqopt->info[cnt].dqi_dirty_list;
451 while (!list_empty(dirty)) {
452 dquot = list_entry(dirty->next, struct dquot, dq_dirty);
453 /* Dirty and inactive can be only bad dquot... */
454 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
455 clear_dquot_dirty(dquot);
456 continue;
457 }
458 /* Now we have active dquot from which someone is
459 * holding reference so we can safely just increase
460 * use count */
461 atomic_inc(&dquot->dq_count);
462 dqstats.lookups++;
463 spin_unlock(&dq_list_lock);
464 sb->dq_op->write_dquot(dquot);
465 dqput(dquot);
466 spin_lock(&dq_list_lock);
467 }
468 spin_unlock(&dq_list_lock);
469 }
470
471 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
472 if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt)
473 && info_dirty(&dqopt->info[cnt]))
474 sb->dq_op->write_info(sb, cnt);
475 spin_lock(&dq_list_lock);
476 dqstats.syncs++;
477 spin_unlock(&dq_list_lock);
478 up(&dqopt->dqonoff_sem);
479
480 return 0;
481}
482
483/* Free unused dquots from cache */
484static void prune_dqcache(int count)
485{
486 struct list_head *head;
487 struct dquot *dquot;
488
489 head = free_dquots.prev;
490 while (head != &free_dquots && count) {
491 dquot = list_entry(head, struct dquot, dq_free);
492 remove_dquot_hash(dquot);
493 remove_free_dquot(dquot);
494 remove_inuse(dquot);
495 kmem_cache_free(dquot_cachep, dquot);
496 count--;
497 head = free_dquots.prev;
498 }
499}
500
501/*
502 * This is called from kswapd when we think we need some
503 * more memory
504 */
505
506static int shrink_dqcache_memory(int nr, unsigned int gfp_mask)
507{
508 if (nr) {
509 spin_lock(&dq_list_lock);
510 prune_dqcache(nr);
511 spin_unlock(&dq_list_lock);
512 }
513 return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
514}
515
516/*
517 * Put reference to dquot
518 * NOTE: If you change this function please check whether dqput_blocks() works right...
519 * MUST be called with either dqptr_sem or dqonoff_sem held
520 */
521static void dqput(struct dquot *dquot)
522{
523 if (!dquot)
524 return;
525#ifdef __DQUOT_PARANOIA
526 if (!atomic_read(&dquot->dq_count)) {
527 printk("VFS: dqput: trying to free free dquot\n");
528 printk("VFS: device %s, dquot of %s %d\n",
529 dquot->dq_sb->s_id,
530 quotatypes[dquot->dq_type],
531 dquot->dq_id);
532 BUG();
533 }
534#endif
535
536 spin_lock(&dq_list_lock);
537 dqstats.drops++;
538 spin_unlock(&dq_list_lock);
539we_slept:
540 spin_lock(&dq_list_lock);
541 if (atomic_read(&dquot->dq_count) > 1) {
542 /* We have more than one user... nothing to do */
543 atomic_dec(&dquot->dq_count);
544 spin_unlock(&dq_list_lock);
545 return;
546 }
547 /* Need to release dquot? */
548 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
549 spin_unlock(&dq_list_lock);
550 /* Commit dquot before releasing */
551 dquot->dq_sb->dq_op->write_dquot(dquot);
552 goto we_slept;
553 }
554 /* Clear flag in case dquot was inactive (something bad happened) */
555 clear_dquot_dirty(dquot);
556 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
557 spin_unlock(&dq_list_lock);
558 dquot->dq_sb->dq_op->release_dquot(dquot);
559 goto we_slept;
560 }
561 atomic_dec(&dquot->dq_count);
562#ifdef __DQUOT_PARANOIA
563 /* sanity check */
564 if (!list_empty(&dquot->dq_free))
565 BUG();
566#endif
567 put_dquot_last(dquot);
568 spin_unlock(&dq_list_lock);
569}
570
571static struct dquot *get_empty_dquot(struct super_block *sb, int type)
572{
573 struct dquot *dquot;
574
575 dquot = kmem_cache_alloc(dquot_cachep, SLAB_NOFS);
576 if(!dquot)
577 return NODQUOT;
578
579 memset((caddr_t)dquot, 0, sizeof(struct dquot));
580 sema_init(&dquot->dq_lock, 1);
581 INIT_LIST_HEAD(&dquot->dq_free);
582 INIT_LIST_HEAD(&dquot->dq_inuse);
583 INIT_HLIST_NODE(&dquot->dq_hash);
584 INIT_LIST_HEAD(&dquot->dq_dirty);
585 dquot->dq_sb = sb;
586 dquot->dq_type = type;
587 atomic_set(&dquot->dq_count, 1);
588
589 return dquot;
590}
591
592/*
593 * Get reference to dquot
594 * MUST be called with either dqptr_sem or dqonoff_sem held
595 */
596static struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
597{
598 unsigned int hashent = hashfn(sb, id, type);
599 struct dquot *dquot, *empty = NODQUOT;
600
601 if (!sb_has_quota_enabled(sb, type))
602 return NODQUOT;
603we_slept:
604 spin_lock(&dq_list_lock);
605 if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) {
606 if (empty == NODQUOT) {
607 spin_unlock(&dq_list_lock);
608 if ((empty = get_empty_dquot(sb, type)) == NODQUOT)
609 schedule(); /* Try to wait for a moment... */
610 goto we_slept;
611 }
612 dquot = empty;
613 dquot->dq_id = id;
614 /* all dquots go on the inuse_list */
615 put_inuse(dquot);
616 /* hash it first so it can be found */
617 insert_dquot_hash(dquot);
618 dqstats.lookups++;
619 spin_unlock(&dq_list_lock);
620 } else {
621 if (!atomic_read(&dquot->dq_count))
622 remove_free_dquot(dquot);
623 atomic_inc(&dquot->dq_count);
624 dqstats.cache_hits++;
625 dqstats.lookups++;
626 spin_unlock(&dq_list_lock);
627 if (empty)
628 kmem_cache_free(dquot_cachep, empty);
629 }
630 /* Wait for dq_lock - after this we know that either dquot_release() is already
631 * finished or it will be canceled due to dq_count > 1 test */
632 wait_on_dquot(dquot);
633 /* Read the dquot and instantiate it (everything done only if needed) */
634 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
635 dqput(dquot);
636 return NODQUOT;
637 }
638#ifdef __DQUOT_PARANOIA
639 if (!dquot->dq_sb) /* Has somebody invalidated entry under us? */
640 BUG();
641#endif
642
643 return dquot;
644}
645
646static int dqinit_needed(struct inode *inode, int type)
647{
648 int cnt;
649
650 if (IS_NOQUOTA(inode))
651 return 0;
652 if (type != -1)
653 return inode->i_dquot[type] == NODQUOT;
654 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
655 if (inode->i_dquot[cnt] == NODQUOT)
656 return 1;
657 return 0;
658}
659
660/* This routine is guarded by dqonoff_sem semaphore */
661static void add_dquot_ref(struct super_block *sb, int type)
662{
663 struct list_head *p;
664
665restart:
666 file_list_lock();
667 list_for_each(p, &sb->s_files) {
668 struct file *filp = list_entry(p, struct file, f_list);
669 struct inode *inode = filp->f_dentry->d_inode;
670 if (filp->f_mode & FMODE_WRITE && dqinit_needed(inode, type)) {
671 struct dentry *dentry = dget(filp->f_dentry);
672 file_list_unlock();
673 sb->dq_op->initialize(inode, type);
674 dput(dentry);
675 /* As we may have blocked we had better restart... */
676 goto restart;
677 }
678 }
679 file_list_unlock();
680}
681
682/* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */
683static inline int dqput_blocks(struct dquot *dquot)
684{
685 if (atomic_read(&dquot->dq_count) <= 1)
686 return 1;
687 return 0;
688}
689
690/* Remove references to dquots from inode - add dquot to list for freeing if needed */
691/* We can't race with anybody because we hold dqptr_sem for writing... */
692int remove_inode_dquot_ref(struct inode *inode, int type, struct list_head *tofree_head)
693{
694 struct dquot *dquot = inode->i_dquot[type];
695
696 inode->i_dquot[type] = NODQUOT;
697 if (dquot != NODQUOT) {
698 if (dqput_blocks(dquot)) {
699#ifdef __DQUOT_PARANOIA
700 if (atomic_read(&dquot->dq_count) != 1)
701 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
702#endif
703 spin_lock(&dq_list_lock);
704 list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */
705 spin_unlock(&dq_list_lock);
706 return 1;
707 }
708 else
709 dqput(dquot); /* We have guaranteed we won't block */
710 }
711 return 0;
712}
713
714/* Free list of dquots - called from inode.c */
715/* dquots are removed from inodes, no new references can be got so we are the only ones holding reference */
716static void put_dquot_list(struct list_head *tofree_head)
717{
718 struct list_head *act_head;
719 struct dquot *dquot;
720
721 act_head = tofree_head->next;
722 /* So now we have dquots on the list... Just free them */
723 while (act_head != tofree_head) {
724 dquot = list_entry(act_head, struct dquot, dq_free);
725 act_head = act_head->next;
726 list_del_init(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */
727 dqput(dquot);
728 }
729}
730
731/* Gather all references from inodes and drop them */
732static void drop_dquot_ref(struct super_block *sb, int type)
733{
734 LIST_HEAD(tofree_head);
735
736 /* We need to be guarded against prune_icache to reach all the
737 * inodes - otherwise some can be on the local list of prune_icache */
738 down(&iprune_sem);
739 down_write(&sb_dqopt(sb)->dqptr_sem);
740 remove_dquot_ref(sb, type, &tofree_head);
741 up_write(&sb_dqopt(sb)->dqptr_sem);
742 up(&iprune_sem);
743 put_dquot_list(&tofree_head);
744}
745
746static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number)
747{
748 dquot->dq_dqb.dqb_curinodes += number;
749}
750
751static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
752{
753 dquot->dq_dqb.dqb_curspace += number;
754}
755
756static inline void dquot_decr_inodes(struct dquot *dquot, unsigned long number)
757{
758 if (dquot->dq_dqb.dqb_curinodes > number)
759 dquot->dq_dqb.dqb_curinodes -= number;
760 else
761 dquot->dq_dqb.dqb_curinodes = 0;
762 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
763 dquot->dq_dqb.dqb_itime = (time_t) 0;
764 clear_bit(DQ_INODES_B, &dquot->dq_flags);
765}
766
767static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
768{
769 if (dquot->dq_dqb.dqb_curspace > number)
770 dquot->dq_dqb.dqb_curspace -= number;
771 else
772 dquot->dq_dqb.dqb_curspace = 0;
773 if (toqb(dquot->dq_dqb.dqb_curspace) <= dquot->dq_dqb.dqb_bsoftlimit)
774 dquot->dq_dqb.dqb_btime = (time_t) 0;
775 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
776}
777
778static int flag_print_warnings = 1;
779
780static inline int need_print_warning(struct dquot *dquot)
781{
782 if (!flag_print_warnings)
783 return 0;
784
785 switch (dquot->dq_type) {
786 case USRQUOTA:
787 return current->fsuid == dquot->dq_id;
788 case GRPQUOTA:
789 return in_group_p(dquot->dq_id);
790 }
791 return 0;
792}
793
794/* Values of warnings */
795#define NOWARN 0
796#define IHARDWARN 1
797#define ISOFTLONGWARN 2
798#define ISOFTWARN 3
799#define BHARDWARN 4
800#define BSOFTLONGWARN 5
801#define BSOFTWARN 6
802
803/* Print warning to user which exceeded quota */
804static void print_warning(struct dquot *dquot, const char warntype)
805{
806 char *msg = NULL;
807 int flag = (warntype == BHARDWARN || warntype == BSOFTLONGWARN) ? DQ_BLKS_B :
808 ((warntype == IHARDWARN || warntype == ISOFTLONGWARN) ? DQ_INODES_B : 0);
809
810 if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags)))
811 return;
812
813 tty_write_message(current->signal->tty, dquot->dq_sb->s_id);
814 if (warntype == ISOFTWARN || warntype == BSOFTWARN)
815 tty_write_message(current->signal->tty, ": warning, ");
816 else
817 tty_write_message(current->signal->tty, ": write failed, ");
818 tty_write_message(current->signal->tty, quotatypes[dquot->dq_type]);
819 switch (warntype) {
820 case IHARDWARN:
821 msg = " file limit reached.\r\n";
822 break;
823 case ISOFTLONGWARN:
824 msg = " file quota exceeded too long.\r\n";
825 break;
826 case ISOFTWARN:
827 msg = " file quota exceeded.\r\n";
828 break;
829 case BHARDWARN:
830 msg = " block limit reached.\r\n";
831 break;
832 case BSOFTLONGWARN:
833 msg = " block quota exceeded too long.\r\n";
834 break;
835 case BSOFTWARN:
836 msg = " block quota exceeded.\r\n";
837 break;
838 }
839 tty_write_message(current->signal->tty, msg);
840}
841
842static inline void flush_warnings(struct dquot **dquots, char *warntype)
843{
844 int i;
845
846 for (i = 0; i < MAXQUOTAS; i++)
847 if (dquots[i] != NODQUOT && warntype[i] != NOWARN)
848 print_warning(dquots[i], warntype[i]);
849}
850
851static inline char ignore_hardlimit(struct dquot *dquot)
852{
853 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
854
855 return capable(CAP_SYS_RESOURCE) &&
856 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & V1_DQF_RSQUASH));
857}
858
859/* needs dq_data_lock */
860static int check_idq(struct dquot *dquot, ulong inodes, char *warntype)
861{
862 *warntype = NOWARN;
863 if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
864 return QUOTA_OK;
865
866 if (dquot->dq_dqb.dqb_ihardlimit &&
867 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit &&
868 !ignore_hardlimit(dquot)) {
869 *warntype = IHARDWARN;
870 return NO_QUOTA;
871 }
872
873 if (dquot->dq_dqb.dqb_isoftlimit &&
874 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
875 dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime &&
876 !ignore_hardlimit(dquot)) {
877 *warntype = ISOFTLONGWARN;
878 return NO_QUOTA;
879 }
880
881 if (dquot->dq_dqb.dqb_isoftlimit &&
882 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
883 dquot->dq_dqb.dqb_itime == 0) {
884 *warntype = ISOFTWARN;
885 dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
886 }
887
888 return QUOTA_OK;
889}
890
891/* needs dq_data_lock */
892static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
893{
894 *warntype = 0;
895 if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
896 return QUOTA_OK;
897
898 if (dquot->dq_dqb.dqb_bhardlimit &&
899 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bhardlimit &&
900 !ignore_hardlimit(dquot)) {
901 if (!prealloc)
902 *warntype = BHARDWARN;
903 return NO_QUOTA;
904 }
905
906 if (dquot->dq_dqb.dqb_bsoftlimit &&
907 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
908 dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime &&
909 !ignore_hardlimit(dquot)) {
910 if (!prealloc)
911 *warntype = BSOFTLONGWARN;
912 return NO_QUOTA;
913 }
914
915 if (dquot->dq_dqb.dqb_bsoftlimit &&
916 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
917 dquot->dq_dqb.dqb_btime == 0) {
918 if (!prealloc) {
919 *warntype = BSOFTWARN;
920 dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
921 }
922 else
923 /*
924 * We don't allow preallocation to exceed softlimit so exceeding will
925 * be always printed
926 */
927 return NO_QUOTA;
928 }
929
930 return QUOTA_OK;
931}
932
933/*
934 * Initialize quota pointers in inode
935 * Transaction must be started at entry
936 */
937int dquot_initialize(struct inode *inode, int type)
938{
939 unsigned int id = 0;
940 int cnt, ret = 0;
941
942 /* First test before acquiring semaphore - solves deadlocks when we
943 * re-enter the quota code and are already holding the semaphore */
944 if (IS_NOQUOTA(inode))
945 return 0;
946 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
947 /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
948 if (IS_NOQUOTA(inode))
949 goto out_err;
950 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
951 if (type != -1 && cnt != type)
952 continue;
953 if (inode->i_dquot[cnt] == NODQUOT) {
954 switch (cnt) {
955 case USRQUOTA:
956 id = inode->i_uid;
957 break;
958 case GRPQUOTA:
959 id = inode->i_gid;
960 break;
961 }
962 inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt);
963 }
964 }
965out_err:
966 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
967 return ret;
968}
969
970/*
971 * Release all quotas referenced by inode
972 * Transaction must be started at an entry
973 */
974int dquot_drop(struct inode *inode)
975{
976 int cnt;
977
978 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
979 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
980 if (inode->i_dquot[cnt] != NODQUOT) {
981 dqput(inode->i_dquot[cnt]);
982 inode->i_dquot[cnt] = NODQUOT;
983 }
984 }
985 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
986 return 0;
987}
988
989/*
990 * Following four functions update i_blocks+i_bytes fields and
991 * quota information (together with appropriate checks)
992 * NOTE: We absolutely rely on the fact that caller dirties
993 * the inode (usually macros in quotaops.h care about this) and
994 * holds a handle for the current transaction so that dquot write and
995 * inode write go into the same transaction.
996 */
997
998/*
999 * This operation can block, but only after everything is updated
1000 */
1001int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1002{
1003 int cnt, ret = NO_QUOTA;
1004 char warntype[MAXQUOTAS];
1005
1006 /* First test before acquiring semaphore - solves deadlocks when we
1007 * re-enter the quota code and are already holding the semaphore */
1008 if (IS_NOQUOTA(inode)) {
1009out_add:
1010 inode_add_bytes(inode, number);
1011 return QUOTA_OK;
1012 }
1013 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1014 warntype[cnt] = NOWARN;
1015
1016 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1017 if (IS_NOQUOTA(inode)) { /* Now we can do reliable test... */
1018 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1019 goto out_add;
1020 }
1021 spin_lock(&dq_data_lock);
1022 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1023 if (inode->i_dquot[cnt] == NODQUOT)
1024 continue;
1025 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA)
1026 goto warn_put_all;
1027 }
1028 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1029 if (inode->i_dquot[cnt] == NODQUOT)
1030 continue;
1031 dquot_incr_space(inode->i_dquot[cnt], number);
1032 }
1033 inode_add_bytes(inode, number);
1034 ret = QUOTA_OK;
1035warn_put_all:
1036 spin_unlock(&dq_data_lock);
1037 if (ret == QUOTA_OK)
1038 /* Dirtify all the dquots - this can block when journalling */
1039 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1040 if (inode->i_dquot[cnt])
1041 mark_dquot_dirty(inode->i_dquot[cnt]);
1042 flush_warnings(inode->i_dquot, warntype);
1043 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1044 return ret;
1045}
1046
1047/*
1048 * This operation can block, but only after everything is updated
1049 */
1050int dquot_alloc_inode(const struct inode *inode, unsigned long number)
1051{
1052 int cnt, ret = NO_QUOTA;
1053 char warntype[MAXQUOTAS];
1054
1055 /* First test before acquiring semaphore - solves deadlocks when we
1056 * re-enter the quota code and are already holding the semaphore */
1057 if (IS_NOQUOTA(inode))
1058 return QUOTA_OK;
1059 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1060 warntype[cnt] = NOWARN;
1061 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1062 if (IS_NOQUOTA(inode)) {
1063 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1064 return QUOTA_OK;
1065 }
1066 spin_lock(&dq_data_lock);
1067 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1068 if (inode->i_dquot[cnt] == NODQUOT)
1069 continue;
1070 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA)
1071 goto warn_put_all;
1072 }
1073
1074 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1075 if (inode->i_dquot[cnt] == NODQUOT)
1076 continue;
1077 dquot_incr_inodes(inode->i_dquot[cnt], number);
1078 }
1079 ret = QUOTA_OK;
1080warn_put_all:
1081 spin_unlock(&dq_data_lock);
1082 if (ret == QUOTA_OK)
1083 /* Dirtify all the dquots - this can block when journalling */
1084 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1085 if (inode->i_dquot[cnt])
1086 mark_dquot_dirty(inode->i_dquot[cnt]);
1087 flush_warnings((struct dquot **)inode->i_dquot, warntype);
1088 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1089 return ret;
1090}
1091
1092/*
1093 * This operation can block, but only after everything is updated
1094 */
1095int dquot_free_space(struct inode *inode, qsize_t number)
1096{
1097 unsigned int cnt;
1098
1099 /* First test before acquiring semaphore - solves deadlocks when we
1100 * re-enter the quota code and are already holding the semaphore */
1101 if (IS_NOQUOTA(inode)) {
1102out_sub:
1103 inode_sub_bytes(inode, number);
1104 return QUOTA_OK;
1105 }
1106 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1107 /* Now recheck reliably when holding dqptr_sem */
1108 if (IS_NOQUOTA(inode)) {
1109 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1110 goto out_sub;
1111 }
1112 spin_lock(&dq_data_lock);
1113 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1114 if (inode->i_dquot[cnt] == NODQUOT)
1115 continue;
1116 dquot_decr_space(inode->i_dquot[cnt], number);
1117 }
1118 inode_sub_bytes(inode, number);
1119 spin_unlock(&dq_data_lock);
1120 /* Dirtify all the dquots - this can block when journalling */
1121 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1122 if (inode->i_dquot[cnt])
1123 mark_dquot_dirty(inode->i_dquot[cnt]);
1124 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1125 return QUOTA_OK;
1126}
1127
1128/*
1129 * This operation can block, but only after everything is updated
1130 */
1131int dquot_free_inode(const struct inode *inode, unsigned long number)
1132{
1133 unsigned int cnt;
1134
1135 /* First test before acquiring semaphore - solves deadlocks when we
1136 * re-enter the quota code and are already holding the semaphore */
1137 if (IS_NOQUOTA(inode))
1138 return QUOTA_OK;
1139 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1140 /* Now recheck reliably when holding dqptr_sem */
1141 if (IS_NOQUOTA(inode)) {
1142 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1143 return QUOTA_OK;
1144 }
1145 spin_lock(&dq_data_lock);
1146 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1147 if (inode->i_dquot[cnt] == NODQUOT)
1148 continue;
1149 dquot_decr_inodes(inode->i_dquot[cnt], number);
1150 }
1151 spin_unlock(&dq_data_lock);
1152 /* Dirtify all the dquots - this can block when journalling */
1153 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1154 if (inode->i_dquot[cnt])
1155 mark_dquot_dirty(inode->i_dquot[cnt]);
1156 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1157 return QUOTA_OK;
1158}
1159
1160/*
1161 * Transfer the number of inode and blocks from one diskquota to an other.
1162 *
1163 * This operation can block, but only after everything is updated
1164 * A transaction must be started when entering this function.
1165 */
1166int dquot_transfer(struct inode *inode, struct iattr *iattr)
1167{
1168 qsize_t space;
1169 struct dquot *transfer_from[MAXQUOTAS];
1170 struct dquot *transfer_to[MAXQUOTAS];
1171 int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid,
1172 chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid;
1173 char warntype[MAXQUOTAS];
1174
1175 /* First test before acquiring semaphore - solves deadlocks when we
1176 * re-enter the quota code and are already holding the semaphore */
1177 if (IS_NOQUOTA(inode))
1178 return QUOTA_OK;
1179 /* Clear the arrays */
1180 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1181 transfer_to[cnt] = transfer_from[cnt] = NODQUOT;
1182 warntype[cnt] = NOWARN;
1183 }
1184 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1185 /* Now recheck reliably when holding dqptr_sem */
1186 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */
1187 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1188 return QUOTA_OK;
1189 }
1190 /* First build the transfer_to list - here we can block on
1191 * reading/instantiating of dquots. We know that the transaction for
1192 * us was already started so we don't violate lock ranking here */
1193 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1194 switch (cnt) {
1195 case USRQUOTA:
1196 if (!chuid)
1197 continue;
1198 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt);
1199 break;
1200 case GRPQUOTA:
1201 if (!chgid)
1202 continue;
1203 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt);
1204 break;
1205 }
1206 }
1207 spin_lock(&dq_data_lock);
1208 space = inode_get_bytes(inode);
1209 /* Build the transfer_from list and check the limits */
1210 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1211 if (transfer_to[cnt] == NODQUOT)
1212 continue;
1213 transfer_from[cnt] = inode->i_dquot[cnt];
1214 if (check_idq(transfer_to[cnt], 1, warntype+cnt) == NO_QUOTA ||
1215 check_bdq(transfer_to[cnt], space, 0, warntype+cnt) == NO_QUOTA)
1216 goto warn_put_all;
1217 }
1218
1219 /*
1220 * Finally perform the needed transfer from transfer_from to transfer_to
1221 */
1222 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1223 /*
1224 * Skip changes for same uid or gid or for turned off quota-type.
1225 */
1226 if (transfer_to[cnt] == NODQUOT)
1227 continue;
1228
1229 /* Due to IO error we might not have transfer_from[] structure */
1230 if (transfer_from[cnt]) {
1231 dquot_decr_inodes(transfer_from[cnt], 1);
1232 dquot_decr_space(transfer_from[cnt], space);
1233 }
1234
1235 dquot_incr_inodes(transfer_to[cnt], 1);
1236 dquot_incr_space(transfer_to[cnt], space);
1237
1238 inode->i_dquot[cnt] = transfer_to[cnt];
1239 }
1240 ret = QUOTA_OK;
1241warn_put_all:
1242 spin_unlock(&dq_data_lock);
1243 /* Dirtify all the dquots - this can block when journalling */
1244 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1245 if (transfer_from[cnt])
1246 mark_dquot_dirty(transfer_from[cnt]);
1247 if (transfer_to[cnt])
1248 mark_dquot_dirty(transfer_to[cnt]);
1249 }
1250 flush_warnings(transfer_to, warntype);
1251
1252 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1253 if (ret == QUOTA_OK && transfer_from[cnt] != NODQUOT)
1254 dqput(transfer_from[cnt]);
1255 if (ret == NO_QUOTA && transfer_to[cnt] != NODQUOT)
1256 dqput(transfer_to[cnt]);
1257 }
1258 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1259 return ret;
1260}
1261
1262/*
1263 * Write info of quota file to disk
1264 */
1265int dquot_commit_info(struct super_block *sb, int type)
1266{
1267 int ret;
1268 struct quota_info *dqopt = sb_dqopt(sb);
1269
1270 down(&dqopt->dqio_sem);
1271 ret = dqopt->ops[type]->write_file_info(sb, type);
1272 up(&dqopt->dqio_sem);
1273 return ret;
1274}
1275
1276/*
1277 * Definitions of diskquota operations.
1278 */
1279struct dquot_operations dquot_operations = {
1280 .initialize = dquot_initialize,
1281 .drop = dquot_drop,
1282 .alloc_space = dquot_alloc_space,
1283 .alloc_inode = dquot_alloc_inode,
1284 .free_space = dquot_free_space,
1285 .free_inode = dquot_free_inode,
1286 .transfer = dquot_transfer,
1287 .write_dquot = dquot_commit,
1288 .acquire_dquot = dquot_acquire,
1289 .release_dquot = dquot_release,
1290 .mark_dirty = dquot_mark_dquot_dirty,
1291 .write_info = dquot_commit_info
1292};
1293
1294static inline void set_enable_flags(struct quota_info *dqopt, int type)
1295{
1296 switch (type) {
1297 case USRQUOTA:
1298 dqopt->flags |= DQUOT_USR_ENABLED;
1299 break;
1300 case GRPQUOTA:
1301 dqopt->flags |= DQUOT_GRP_ENABLED;
1302 break;
1303 }
1304}
1305
1306static inline void reset_enable_flags(struct quota_info *dqopt, int type)
1307{
1308 switch (type) {
1309 case USRQUOTA:
1310 dqopt->flags &= ~DQUOT_USR_ENABLED;
1311 break;
1312 case GRPQUOTA:
1313 dqopt->flags &= ~DQUOT_GRP_ENABLED;
1314 break;
1315 }
1316}
1317
1318/*
1319 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1320 */
1321int vfs_quota_off(struct super_block *sb, int type)
1322{
1323 int cnt;
1324 struct quota_info *dqopt = sb_dqopt(sb);
1325 struct inode *toputinode[MAXQUOTAS];
1326 struct vfsmount *toputmnt[MAXQUOTAS];
1327
1328 /* We need to serialize quota_off() for device */
1329 down(&dqopt->dqonoff_sem);
1330 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1331 toputinode[cnt] = NULL;
1332 toputmnt[cnt] = NULL;
1333 if (type != -1 && cnt != type)
1334 continue;
1335 if (!sb_has_quota_enabled(sb, cnt))
1336 continue;
1337 reset_enable_flags(dqopt, cnt);
1338
1339 /* Note: these are blocking operations */
1340 drop_dquot_ref(sb, cnt);
1341 invalidate_dquots(sb, cnt);
1342 /*
1343 * Now all dquots should be invalidated, all writes done so we should be only
1344 * users of the info. No locks needed.
1345 */
1346 if (info_dirty(&dqopt->info[cnt]))
1347 sb->dq_op->write_info(sb, cnt);
1348 if (dqopt->ops[cnt]->free_file_info)
1349 dqopt->ops[cnt]->free_file_info(sb, cnt);
1350 put_quota_format(dqopt->info[cnt].dqi_format);
1351
1352 toputinode[cnt] = dqopt->files[cnt];
1353 toputmnt[cnt] = dqopt->mnt[cnt];
1354 dqopt->files[cnt] = NULL;
1355 dqopt->mnt[cnt] = NULL;
1356 dqopt->info[cnt].dqi_flags = 0;
1357 dqopt->info[cnt].dqi_igrace = 0;
1358 dqopt->info[cnt].dqi_bgrace = 0;
1359 dqopt->ops[cnt] = NULL;
1360 }
1361 up(&dqopt->dqonoff_sem);
1362 /* Sync the superblock so that buffers with quota data are written to
1363 * disk (and so userspace sees correct data afterwards).
1364 * The reference to vfsmnt we are still holding protects us from
1365 * umount (we don't have it only when quotas are turned on/off for
1366 * journal replay but in that case we are guarded by the fs anyway). */
1367 if (sb->s_op->sync_fs)
1368 sb->s_op->sync_fs(sb, 1);
1369 sync_blockdev(sb->s_bdev);
1370 /* Now the quota files are just ordinary files and we can set the
1371 * inode flags back. Moreover we discard the pagecache so that
1372 * userspace sees the writes we did bypassing the pagecache. We
1373 * must also discard the blockdev buffers so that we see the
1374 * changes done by userspace on the next quotaon() */
1375 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1376 if (toputinode[cnt]) {
1377 down(&dqopt->dqonoff_sem);
1378 /* If quota was reenabled in the meantime, we have
1379 * nothing to do */
1380 if (!sb_has_quota_enabled(sb, cnt)) {
1381 down(&toputinode[cnt]->i_sem);
1382 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1383 S_NOATIME | S_NOQUOTA);
1384 truncate_inode_pages(&toputinode[cnt]->i_data, 0);
1385 up(&toputinode[cnt]->i_sem);
1386 mark_inode_dirty(toputinode[cnt]);
1387 iput(toputinode[cnt]);
1388 }
1389 up(&dqopt->dqonoff_sem);
1390 /* We don't hold the reference when we turned on quotas
1391 * just for the journal replay... */
1392 if (toputmnt[cnt])
1393 mntput(toputmnt[cnt]);
1394 }
1395 if (sb->s_bdev)
1396 invalidate_bdev(sb->s_bdev, 0);
1397 return 0;
1398}
1399
1400/*
1401 * Turn quotas on on a device
1402 */
1403
1404/* Helper function when we already have the inode */
1405static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
1406{
1407 struct quota_format_type *fmt = find_quota_format(format_id);
1408 struct super_block *sb = inode->i_sb;
1409 struct quota_info *dqopt = sb_dqopt(sb);
1410 int error;
1411 int oldflags = -1;
1412
1413 if (!fmt)
1414 return -ESRCH;
1415 if (!S_ISREG(inode->i_mode)) {
1416 error = -EACCES;
1417 goto out_fmt;
1418 }
1419 if (IS_RDONLY(inode)) {
1420 error = -EROFS;
1421 goto out_fmt;
1422 }
1423 if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
1424 error = -EINVAL;
1425 goto out_fmt;
1426 }
1427
1428 /* As we bypass the pagecache we must now flush the inode so that
1429 * we see all the changes from userspace... */
1430 write_inode_now(inode, 1);
1431 /* And now flush the block cache so that kernel sees the changes */
1432 invalidate_bdev(sb->s_bdev, 0);
1433 down(&inode->i_sem);
1434 down(&dqopt->dqonoff_sem);
1435 if (sb_has_quota_enabled(sb, type)) {
1436 error = -EBUSY;
1437 goto out_lock;
1438 }
1439 /* We don't want quota and atime on quota files (deadlocks possible)
1440 * Also nobody should write to the file - we use special IO operations
1441 * which ignore the immutable bit. */
1442 down_write(&dqopt->dqptr_sem);
1443 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA);
1444 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
1445 up_write(&dqopt->dqptr_sem);
Jan Kara31e7ad62005-04-16 15:25:46 -07001446 sb->dq_op->drop(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447
1448 error = -EIO;
1449 dqopt->files[type] = igrab(inode);
1450 if (!dqopt->files[type])
1451 goto out_lock;
1452 error = -EINVAL;
1453 if (!fmt->qf_ops->check_quota_file(sb, type))
1454 goto out_file_init;
1455
1456 dqopt->ops[type] = fmt->qf_ops;
1457 dqopt->info[type].dqi_format = fmt;
1458 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
1459 down(&dqopt->dqio_sem);
1460 if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) {
1461 up(&dqopt->dqio_sem);
1462 goto out_file_init;
1463 }
1464 up(&dqopt->dqio_sem);
1465 up(&inode->i_sem);
1466 set_enable_flags(dqopt, type);
1467
1468 add_dquot_ref(sb, type);
1469 up(&dqopt->dqonoff_sem);
1470
1471 return 0;
1472
1473out_file_init:
1474 dqopt->files[type] = NULL;
1475 iput(inode);
1476out_lock:
1477 up(&dqopt->dqonoff_sem);
1478 if (oldflags != -1) {
1479 down_write(&dqopt->dqptr_sem);
1480 /* Set the flags back (in the case of accidental quotaon()
1481 * on a wrong file we don't want to mess up the flags) */
1482 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
1483 inode->i_flags |= oldflags;
1484 up_write(&dqopt->dqptr_sem);
1485 }
1486 up(&inode->i_sem);
1487out_fmt:
1488 put_quota_format(fmt);
1489
1490 return error;
1491}
1492
1493/* Actual function called from quotactl() */
1494int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path)
1495{
1496 struct nameidata nd;
1497 int error;
1498
1499 error = path_lookup(path, LOOKUP_FOLLOW, &nd);
1500 if (error < 0)
1501 return error;
1502 error = security_quota_on(nd.dentry);
1503 if (error)
1504 goto out_path;
1505 /* Quota file not on the same filesystem? */
1506 if (nd.mnt->mnt_sb != sb)
1507 error = -EXDEV;
1508 else {
1509 error = vfs_quota_on_inode(nd.dentry->d_inode, type, format_id);
1510 if (!error)
1511 sb_dqopt(sb)->mnt[type] = mntget(nd.mnt);
1512 }
1513out_path:
1514 path_release(&nd);
1515 return error;
1516}
1517
1518/*
1519 * This function is used when filesystem needs to initialize quotas
1520 * during mount time.
1521 */
Christoph Hellwig84de8562005-06-23 00:09:16 -07001522int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
1523 int format_id, int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001524{
Christoph Hellwig84de8562005-06-23 00:09:16 -07001525 struct qstr name = {.name = qf_name, .len = 0, .len = strlen(qf_name)};
1526 struct dentry *dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001527 int error;
1528
Christoph Hellwig84de8562005-06-23 00:09:16 -07001529 dentry = lookup_hash(&name, sb->s_root);
1530 if (IS_ERR(dentry))
1531 return PTR_ERR(dentry);
1532
Linus Torvalds1da177e2005-04-16 15:20:36 -07001533 error = security_quota_on(dentry);
Christoph Hellwig84de8562005-06-23 00:09:16 -07001534 if (!error)
1535 error = vfs_quota_on_inode(dentry->d_inode, type, format_id);
1536
1537 /*
1538 * Now invalidate and put the dentry - quota got its own reference
1539 * to inode and dentry has at least wrong hash so we had better
1540 * throw it away.
1541 */
1542 d_invalidate(dentry);
1543 dput(dentry);
1544 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001545}
1546
1547/* Generic routine for getting common part of quota structure */
1548static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
1549{
1550 struct mem_dqblk *dm = &dquot->dq_dqb;
1551
1552 spin_lock(&dq_data_lock);
1553 di->dqb_bhardlimit = dm->dqb_bhardlimit;
1554 di->dqb_bsoftlimit = dm->dqb_bsoftlimit;
1555 di->dqb_curspace = dm->dqb_curspace;
1556 di->dqb_ihardlimit = dm->dqb_ihardlimit;
1557 di->dqb_isoftlimit = dm->dqb_isoftlimit;
1558 di->dqb_curinodes = dm->dqb_curinodes;
1559 di->dqb_btime = dm->dqb_btime;
1560 di->dqb_itime = dm->dqb_itime;
1561 di->dqb_valid = QIF_ALL;
1562 spin_unlock(&dq_data_lock);
1563}
1564
1565int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
1566{
1567 struct dquot *dquot;
1568
1569 down(&sb_dqopt(sb)->dqonoff_sem);
1570 if (!(dquot = dqget(sb, id, type))) {
1571 up(&sb_dqopt(sb)->dqonoff_sem);
1572 return -ESRCH;
1573 }
1574 do_get_dqblk(dquot, di);
1575 dqput(dquot);
1576 up(&sb_dqopt(sb)->dqonoff_sem);
1577 return 0;
1578}
1579
1580/* Generic routine for setting common part of quota structure */
1581static void do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
1582{
1583 struct mem_dqblk *dm = &dquot->dq_dqb;
1584 int check_blim = 0, check_ilim = 0;
1585
1586 spin_lock(&dq_data_lock);
1587 if (di->dqb_valid & QIF_SPACE) {
1588 dm->dqb_curspace = di->dqb_curspace;
1589 check_blim = 1;
1590 }
1591 if (di->dqb_valid & QIF_BLIMITS) {
1592 dm->dqb_bsoftlimit = di->dqb_bsoftlimit;
1593 dm->dqb_bhardlimit = di->dqb_bhardlimit;
1594 check_blim = 1;
1595 }
1596 if (di->dqb_valid & QIF_INODES) {
1597 dm->dqb_curinodes = di->dqb_curinodes;
1598 check_ilim = 1;
1599 }
1600 if (di->dqb_valid & QIF_ILIMITS) {
1601 dm->dqb_isoftlimit = di->dqb_isoftlimit;
1602 dm->dqb_ihardlimit = di->dqb_ihardlimit;
1603 check_ilim = 1;
1604 }
1605 if (di->dqb_valid & QIF_BTIME)
1606 dm->dqb_btime = di->dqb_btime;
1607 if (di->dqb_valid & QIF_ITIME)
1608 dm->dqb_itime = di->dqb_itime;
1609
1610 if (check_blim) {
1611 if (!dm->dqb_bsoftlimit || toqb(dm->dqb_curspace) < dm->dqb_bsoftlimit) {
1612 dm->dqb_btime = 0;
1613 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1614 }
1615 else if (!(di->dqb_valid & QIF_BTIME)) /* Set grace only if user hasn't provided his own... */
1616 dm->dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
1617 }
1618 if (check_ilim) {
1619 if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) {
1620 dm->dqb_itime = 0;
1621 clear_bit(DQ_INODES_B, &dquot->dq_flags);
1622 }
1623 else if (!(di->dqb_valid & QIF_ITIME)) /* Set grace only if user hasn't provided his own... */
1624 dm->dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1625 }
1626 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit)
1627 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
1628 else
1629 set_bit(DQ_FAKE_B, &dquot->dq_flags);
1630 spin_unlock(&dq_data_lock);
1631 mark_dquot_dirty(dquot);
1632}
1633
1634int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
1635{
1636 struct dquot *dquot;
1637
1638 down(&sb_dqopt(sb)->dqonoff_sem);
1639 if (!(dquot = dqget(sb, id, type))) {
1640 up(&sb_dqopt(sb)->dqonoff_sem);
1641 return -ESRCH;
1642 }
1643 do_set_dqblk(dquot, di);
1644 dqput(dquot);
1645 up(&sb_dqopt(sb)->dqonoff_sem);
1646 return 0;
1647}
1648
1649/* Generic routine for getting common part of quota file information */
1650int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
1651{
1652 struct mem_dqinfo *mi;
1653
1654 down(&sb_dqopt(sb)->dqonoff_sem);
1655 if (!sb_has_quota_enabled(sb, type)) {
1656 up(&sb_dqopt(sb)->dqonoff_sem);
1657 return -ESRCH;
1658 }
1659 mi = sb_dqopt(sb)->info + type;
1660 spin_lock(&dq_data_lock);
1661 ii->dqi_bgrace = mi->dqi_bgrace;
1662 ii->dqi_igrace = mi->dqi_igrace;
1663 ii->dqi_flags = mi->dqi_flags & DQF_MASK;
1664 ii->dqi_valid = IIF_ALL;
1665 spin_unlock(&dq_data_lock);
1666 up(&sb_dqopt(sb)->dqonoff_sem);
1667 return 0;
1668}
1669
1670/* Generic routine for setting common part of quota file information */
1671int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
1672{
1673 struct mem_dqinfo *mi;
1674
1675 down(&sb_dqopt(sb)->dqonoff_sem);
1676 if (!sb_has_quota_enabled(sb, type)) {
1677 up(&sb_dqopt(sb)->dqonoff_sem);
1678 return -ESRCH;
1679 }
1680 mi = sb_dqopt(sb)->info + type;
1681 spin_lock(&dq_data_lock);
1682 if (ii->dqi_valid & IIF_BGRACE)
1683 mi->dqi_bgrace = ii->dqi_bgrace;
1684 if (ii->dqi_valid & IIF_IGRACE)
1685 mi->dqi_igrace = ii->dqi_igrace;
1686 if (ii->dqi_valid & IIF_FLAGS)
1687 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | (ii->dqi_flags & DQF_MASK);
1688 spin_unlock(&dq_data_lock);
1689 mark_info_dirty(sb, type);
1690 /* Force write to disk */
1691 sb->dq_op->write_info(sb, type);
1692 up(&sb_dqopt(sb)->dqonoff_sem);
1693 return 0;
1694}
1695
1696struct quotactl_ops vfs_quotactl_ops = {
1697 .quota_on = vfs_quota_on,
1698 .quota_off = vfs_quota_off,
1699 .quota_sync = vfs_quota_sync,
1700 .get_info = vfs_get_dqinfo,
1701 .set_info = vfs_set_dqinfo,
1702 .get_dqblk = vfs_get_dqblk,
1703 .set_dqblk = vfs_set_dqblk
1704};
1705
1706static ctl_table fs_dqstats_table[] = {
1707 {
1708 .ctl_name = FS_DQ_LOOKUPS,
1709 .procname = "lookups",
1710 .data = &dqstats.lookups,
1711 .maxlen = sizeof(int),
1712 .mode = 0444,
1713 .proc_handler = &proc_dointvec,
1714 },
1715 {
1716 .ctl_name = FS_DQ_DROPS,
1717 .procname = "drops",
1718 .data = &dqstats.drops,
1719 .maxlen = sizeof(int),
1720 .mode = 0444,
1721 .proc_handler = &proc_dointvec,
1722 },
1723 {
1724 .ctl_name = FS_DQ_READS,
1725 .procname = "reads",
1726 .data = &dqstats.reads,
1727 .maxlen = sizeof(int),
1728 .mode = 0444,
1729 .proc_handler = &proc_dointvec,
1730 },
1731 {
1732 .ctl_name = FS_DQ_WRITES,
1733 .procname = "writes",
1734 .data = &dqstats.writes,
1735 .maxlen = sizeof(int),
1736 .mode = 0444,
1737 .proc_handler = &proc_dointvec,
1738 },
1739 {
1740 .ctl_name = FS_DQ_CACHE_HITS,
1741 .procname = "cache_hits",
1742 .data = &dqstats.cache_hits,
1743 .maxlen = sizeof(int),
1744 .mode = 0444,
1745 .proc_handler = &proc_dointvec,
1746 },
1747 {
1748 .ctl_name = FS_DQ_ALLOCATED,
1749 .procname = "allocated_dquots",
1750 .data = &dqstats.allocated_dquots,
1751 .maxlen = sizeof(int),
1752 .mode = 0444,
1753 .proc_handler = &proc_dointvec,
1754 },
1755 {
1756 .ctl_name = FS_DQ_FREE,
1757 .procname = "free_dquots",
1758 .data = &dqstats.free_dquots,
1759 .maxlen = sizeof(int),
1760 .mode = 0444,
1761 .proc_handler = &proc_dointvec,
1762 },
1763 {
1764 .ctl_name = FS_DQ_SYNCS,
1765 .procname = "syncs",
1766 .data = &dqstats.syncs,
1767 .maxlen = sizeof(int),
1768 .mode = 0444,
1769 .proc_handler = &proc_dointvec,
1770 },
1771 {
1772 .ctl_name = FS_DQ_WARNINGS,
1773 .procname = "warnings",
1774 .data = &flag_print_warnings,
1775 .maxlen = sizeof(int),
1776 .mode = 0644,
1777 .proc_handler = &proc_dointvec,
1778 },
1779 { .ctl_name = 0 },
1780};
1781
1782static ctl_table fs_table[] = {
1783 {
1784 .ctl_name = FS_DQSTATS,
1785 .procname = "quota",
1786 .mode = 0555,
1787 .child = fs_dqstats_table,
1788 },
1789 { .ctl_name = 0 },
1790};
1791
1792static ctl_table sys_table[] = {
1793 {
1794 .ctl_name = CTL_FS,
1795 .procname = "fs",
1796 .mode = 0555,
1797 .child = fs_table,
1798 },
1799 { .ctl_name = 0 },
1800};
1801
1802static int __init dquot_init(void)
1803{
1804 int i;
1805 unsigned long nr_hash, order;
1806
1807 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
1808
1809 register_sysctl_table(sys_table, 0);
1810
1811 dquot_cachep = kmem_cache_create("dquot",
1812 sizeof(struct dquot), sizeof(unsigned long) * 4,
1813 SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_PANIC,
1814 NULL, NULL);
1815
1816 order = 0;
1817 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
1818 if (!dquot_hash)
1819 panic("Cannot create dquot hash table");
1820
1821 /* Find power-of-two hlist_heads which can fit into allocation */
1822 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
1823 dq_hash_bits = 0;
1824 do {
1825 dq_hash_bits++;
1826 } while (nr_hash >> dq_hash_bits);
1827 dq_hash_bits--;
1828
1829 nr_hash = 1UL << dq_hash_bits;
1830 dq_hash_mask = nr_hash - 1;
1831 for (i = 0; i < nr_hash; i++)
1832 INIT_HLIST_HEAD(dquot_hash + i);
1833
1834 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
1835 nr_hash, order, (PAGE_SIZE << order));
1836
1837 set_shrinker(DEFAULT_SEEKS, shrink_dqcache_memory);
1838
1839 return 0;
1840}
1841module_init(dquot_init);
1842
1843EXPORT_SYMBOL(register_quota_format);
1844EXPORT_SYMBOL(unregister_quota_format);
1845EXPORT_SYMBOL(dqstats);
1846EXPORT_SYMBOL(dq_data_lock);
1847EXPORT_SYMBOL(vfs_quota_on);
1848EXPORT_SYMBOL(vfs_quota_on_mount);
1849EXPORT_SYMBOL(vfs_quota_off);
1850EXPORT_SYMBOL(vfs_quota_sync);
1851EXPORT_SYMBOL(vfs_get_dqinfo);
1852EXPORT_SYMBOL(vfs_set_dqinfo);
1853EXPORT_SYMBOL(vfs_get_dqblk);
1854EXPORT_SYMBOL(vfs_set_dqblk);
1855EXPORT_SYMBOL(dquot_commit);
1856EXPORT_SYMBOL(dquot_commit_info);
1857EXPORT_SYMBOL(dquot_acquire);
1858EXPORT_SYMBOL(dquot_release);
1859EXPORT_SYMBOL(dquot_mark_dquot_dirty);
1860EXPORT_SYMBOL(dquot_initialize);
1861EXPORT_SYMBOL(dquot_drop);
1862EXPORT_SYMBOL(dquot_alloc_space);
1863EXPORT_SYMBOL(dquot_alloc_inode);
1864EXPORT_SYMBOL(dquot_free_space);
1865EXPORT_SYMBOL(dquot_free_inode);
1866EXPORT_SYMBOL(dquot_transfer);