blob: 7e273151f58949a09a58ea6d89219b520d8fe72c [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070072#include <linux/init.h>
73#include <linux/module.h>
74#include <linux/proc_fs.h>
75#include <linux/security.h>
76#include <linux/kmod.h>
77#include <linux/namei.h>
78#include <linux/buffer_head.h>
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080079#include <linux/capability.h>
Adrian Bunkbe586ba2005-11-07 00:59:35 -080080#include <linux/quotaops.h>
Christoph Hellwigfb58b732007-02-12 00:51:57 -080081#include <linux/writeback.h> /* for inode_lock, oddly enough.. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
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
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800104 * for altering the flag i_mutex is also needed). If operation is holding
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 * reference to dquot in other way (e.g. quotactl ops) it must be guarded by
Ingo Molnard3be9152006-03-23 03:00:29 -0800106 * dqonoff_mutex.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 * This locking assures that:
108 * a) update/access to dquot pointers in inode is serialized
109 * b) everyone is guarded against invalidate_dquots()
110 *
Ingo Molnard3be9152006-03-23 03:00:29 -0800111 * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 * 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:
Ingo Molnard3be9152006-03-23 03:00:29 -0800121 * 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)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 */
125
126static DEFINE_SPINLOCK(dq_list_lock);
127DEFINE_SPINLOCK(dq_data_lock);
128
129static char *quotatypes[] = INITQFNAMES;
130static struct quota_format_type *quota_formats; /* List of registered formats */
131static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
132
133/* SLAB cache for dquot structures */
Christoph Lametere18b8902006-12-06 20:33:20 -0800134static struct kmem_cache *dquot_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
136int 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
145void 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
156static 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
180static 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
205static LIST_HEAD(inuse_list);
206static LIST_HEAD(free_dquots);
207static unsigned int dq_hash_bits, dq_hash_mask;
208static struct hlist_head *dquot_hash;
209
210struct dqstats dqstats;
211
212static void dqput(struct dquot *dquot);
213
214static inline unsigned int
215hashfn(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 */
226static 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
232static inline void remove_dquot_hash(struct dquot *dquot)
233{
234 hlist_del_init(&dquot->dq_hash);
235}
236
237static 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 */
251static inline void put_dquot_last(struct dquot *dquot)
252{
Akinobu Mita8e130592006-06-26 00:24:37 -0700253 list_add_tail(&dquot->dq_free, &free_dquots);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 dqstats.free_dquots++;
255}
256
257static 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
265static 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 */
Akinobu Mita8e130592006-06-26 00:24:37 -0700269 list_add_tail(&dquot->dq_inuse, &inuse_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 dqstats.allocated_dquots++;
271}
272
273static 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
282static void wait_on_dquot(struct dquot *dquot)
283{
Ingo Molnard3be9152006-03-23 03:00:29 -0800284 mutex_lock(&dquot->dq_lock);
285 mutex_unlock(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286}
287
288#define mark_dquot_dirty(dquot) ((dquot)->dq_sb->dq_op->mark_dirty(dquot))
289
290int 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 */
301static 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
309void 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}
313EXPORT_SYMBOL(mark_info_dirty);
314
315/*
316 * Read dquot from disk and alloc space for it
317 */
318
319int dquot_acquire(struct dquot *dquot)
320{
321 int ret = 0, ret2 = 0;
322 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
323
Ingo Molnard3be9152006-03-23 03:00:29 -0800324 mutex_lock(&dquot->dq_lock);
325 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 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);
345out_iolock:
Ingo Molnard3be9152006-03-23 03:00:29 -0800346 mutex_unlock(&dqopt->dqio_mutex);
347 mutex_unlock(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 return ret;
349}
350
351/*
352 * Write dquot to disk
353 */
354int dquot_commit(struct dquot *dquot)
355{
356 int ret = 0, ret2 = 0;
357 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
358
Ingo Molnard3be9152006-03-23 03:00:29 -0800359 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 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 }
375out_sem:
Ingo Molnard3be9152006-03-23 03:00:29 -0800376 mutex_unlock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 return ret;
378}
379
380/*
381 * Release dquot
382 */
383int dquot_release(struct dquot *dquot)
384{
385 int ret = 0, ret2 = 0;
386 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
387
Ingo Molnard3be9152006-03-23 03:00:29 -0800388 mutex_lock(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 /* Check whether we are not racing with some other dqget() */
390 if (atomic_read(&dquot->dq_count) > 1)
391 goto out_dqlock;
Ingo Molnard3be9152006-03-23 03:00:29 -0800392 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 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);
Ingo Molnard3be9152006-03-23 03:00:29 -0800402 mutex_unlock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403out_dqlock:
Ingo Molnard3be9152006-03-23 03:00:29 -0800404 mutex_unlock(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 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
Jan Kara6362e4d2006-03-23 03:00:17 -0800410 * 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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414static void invalidate_dquots(struct super_block *sb, int type)
415{
Domen Puncerc33ed272005-06-25 14:59:36 -0700416 struct dquot *dquot, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
Jan Kara6362e4d2006-03-23 03:00:17 -0800418restart:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 spin_lock(&dq_list_lock);
Domen Puncerc33ed272005-06-25 14:59:36 -0700420 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 if (dquot->dq_sb != sb)
422 continue;
423 if (dquot->dq_type != type)
424 continue;
Jan Kara6362e4d2006-03-23 03:00:17 -0800425 /* 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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 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
461int 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
Ingo Molnard3be9152006-03-23 03:00:29 -0800468 mutex_lock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 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)) {
Pavel Emelianovb5e61812007-05-08 00:30:19 -0700477 dquot = list_first_entry(dirty, struct dquot, dq_dirty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 /* 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);
Ingo Molnard3be9152006-03-23 03:00:29 -0800503 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
505 return 0;
506}
507
508/* Free unused dquots from cache */
509static 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
Al Viro27496a82005-10-21 03:20:48 -0400531static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532{
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
Rusty Russell8e1f9362007-07-17 04:03:17 -0700541static struct shrinker dqcache_shrinker = {
542 .shrink = shrink_dqcache_memory,
543 .seeks = DEFAULT_SEEKS,
544};
545
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546/*
547 * Put reference to dquot
548 * NOTE: If you change this function please check whether dqput_blocks() works right...
Ingo Molnard3be9152006-03-23 03:00:29 -0800549 * MUST be called with either dqptr_sem or dqonoff_mutex held
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 */
551static void dqput(struct dquot *dquot)
552{
553 if (!dquot)
554 return;
555#ifdef __DQUOT_PARANOIA
556 if (!atomic_read(&dquot->dq_count)) {
557 printk("VFS: dqput: trying to free free dquot\n");
558 printk("VFS: device %s, dquot of %s %d\n",
559 dquot->dq_sb->s_id,
560 quotatypes[dquot->dq_type],
561 dquot->dq_id);
562 BUG();
563 }
564#endif
565
566 spin_lock(&dq_list_lock);
567 dqstats.drops++;
568 spin_unlock(&dq_list_lock);
569we_slept:
570 spin_lock(&dq_list_lock);
571 if (atomic_read(&dquot->dq_count) > 1) {
572 /* We have more than one user... nothing to do */
573 atomic_dec(&dquot->dq_count);
Jan Kara6362e4d2006-03-23 03:00:17 -0800574 /* Releasing dquot during quotaoff phase? */
575 if (!sb_has_quota_enabled(dquot->dq_sb, dquot->dq_type) &&
576 atomic_read(&dquot->dq_count) == 1)
577 wake_up(&dquot->dq_wait_unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 spin_unlock(&dq_list_lock);
579 return;
580 }
581 /* Need to release dquot? */
582 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
583 spin_unlock(&dq_list_lock);
584 /* Commit dquot before releasing */
585 dquot->dq_sb->dq_op->write_dquot(dquot);
586 goto we_slept;
587 }
588 /* Clear flag in case dquot was inactive (something bad happened) */
589 clear_dquot_dirty(dquot);
590 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
591 spin_unlock(&dq_list_lock);
592 dquot->dq_sb->dq_op->release_dquot(dquot);
593 goto we_slept;
594 }
595 atomic_dec(&dquot->dq_count);
596#ifdef __DQUOT_PARANOIA
597 /* sanity check */
Eric Sesterhenn8abf6a42006-04-02 13:36:13 +0200598 BUG_ON(!list_empty(&dquot->dq_free));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599#endif
600 put_dquot_last(dquot);
601 spin_unlock(&dq_list_lock);
602}
603
604static struct dquot *get_empty_dquot(struct super_block *sb, int type)
605{
606 struct dquot *dquot;
607
Robert P. J. Dayc3762222007-02-10 01:45:03 -0800608 dquot = kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 if(!dquot)
610 return NODQUOT;
611
Ingo Molnard3be9152006-03-23 03:00:29 -0800612 mutex_init(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 INIT_LIST_HEAD(&dquot->dq_free);
614 INIT_LIST_HEAD(&dquot->dq_inuse);
615 INIT_HLIST_NODE(&dquot->dq_hash);
616 INIT_LIST_HEAD(&dquot->dq_dirty);
Jan Kara6362e4d2006-03-23 03:00:17 -0800617 init_waitqueue_head(&dquot->dq_wait_unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 dquot->dq_sb = sb;
619 dquot->dq_type = type;
620 atomic_set(&dquot->dq_count, 1);
621
622 return dquot;
623}
624
625/*
626 * Get reference to dquot
Ingo Molnard3be9152006-03-23 03:00:29 -0800627 * MUST be called with either dqptr_sem or dqonoff_mutex held
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 */
629static struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
630{
631 unsigned int hashent = hashfn(sb, id, type);
632 struct dquot *dquot, *empty = NODQUOT;
633
634 if (!sb_has_quota_enabled(sb, type))
635 return NODQUOT;
636we_slept:
637 spin_lock(&dq_list_lock);
638 if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) {
639 if (empty == NODQUOT) {
640 spin_unlock(&dq_list_lock);
641 if ((empty = get_empty_dquot(sb, type)) == NODQUOT)
642 schedule(); /* Try to wait for a moment... */
643 goto we_slept;
644 }
645 dquot = empty;
646 dquot->dq_id = id;
647 /* all dquots go on the inuse_list */
648 put_inuse(dquot);
649 /* hash it first so it can be found */
650 insert_dquot_hash(dquot);
651 dqstats.lookups++;
652 spin_unlock(&dq_list_lock);
653 } else {
654 if (!atomic_read(&dquot->dq_count))
655 remove_free_dquot(dquot);
656 atomic_inc(&dquot->dq_count);
657 dqstats.cache_hits++;
658 dqstats.lookups++;
659 spin_unlock(&dq_list_lock);
660 if (empty)
661 kmem_cache_free(dquot_cachep, empty);
662 }
663 /* Wait for dq_lock - after this we know that either dquot_release() is already
664 * finished or it will be canceled due to dq_count > 1 test */
665 wait_on_dquot(dquot);
666 /* Read the dquot and instantiate it (everything done only if needed) */
667 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
668 dqput(dquot);
669 return NODQUOT;
670 }
671#ifdef __DQUOT_PARANOIA
Eric Sesterhenn8abf6a42006-04-02 13:36:13 +0200672 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673#endif
674
675 return dquot;
676}
677
678static int dqinit_needed(struct inode *inode, int type)
679{
680 int cnt;
681
682 if (IS_NOQUOTA(inode))
683 return 0;
684 if (type != -1)
685 return inode->i_dquot[type] == NODQUOT;
686 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
687 if (inode->i_dquot[cnt] == NODQUOT)
688 return 1;
689 return 0;
690}
691
Ingo Molnard3be9152006-03-23 03:00:29 -0800692/* This routine is guarded by dqonoff_mutex mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693static void add_dquot_ref(struct super_block *sb, int type)
694{
Christoph Hellwigd003fb72007-02-12 00:51:58 -0800695 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696
697restart:
Christoph Hellwigd003fb72007-02-12 00:51:58 -0800698 spin_lock(&inode_lock);
699 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
700 if (!atomic_read(&inode->i_writecount))
701 continue;
702 if (!dqinit_needed(inode, type))
703 continue;
704 if (inode->i_state & (I_FREEING|I_WILL_FREE))
705 continue;
706
707 __iget(inode);
708 spin_unlock(&inode_lock);
709
710 sb->dq_op->initialize(inode, type);
711 iput(inode);
712 /* As we may have blocked we had better restart... */
713 goto restart;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 }
Christoph Hellwigd003fb72007-02-12 00:51:58 -0800715 spin_unlock(&inode_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716}
717
718/* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */
719static inline int dqput_blocks(struct dquot *dquot)
720{
721 if (atomic_read(&dquot->dq_count) <= 1)
722 return 1;
723 return 0;
724}
725
726/* Remove references to dquots from inode - add dquot to list for freeing if needed */
727/* We can't race with anybody because we hold dqptr_sem for writing... */
Adrian Bunke5f00f42007-05-08 00:27:22 -0700728static int remove_inode_dquot_ref(struct inode *inode, int type,
729 struct list_head *tofree_head)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730{
731 struct dquot *dquot = inode->i_dquot[type];
732
733 inode->i_dquot[type] = NODQUOT;
734 if (dquot != NODQUOT) {
735 if (dqput_blocks(dquot)) {
736#ifdef __DQUOT_PARANOIA
737 if (atomic_read(&dquot->dq_count) != 1)
738 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
739#endif
740 spin_lock(&dq_list_lock);
741 list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */
742 spin_unlock(&dq_list_lock);
743 return 1;
744 }
745 else
746 dqput(dquot); /* We have guaranteed we won't block */
747 }
748 return 0;
749}
750
751/* Free list of dquots - called from inode.c */
752/* dquots are removed from inodes, no new references can be got so we are the only ones holding reference */
753static void put_dquot_list(struct list_head *tofree_head)
754{
755 struct list_head *act_head;
756 struct dquot *dquot;
757
758 act_head = tofree_head->next;
759 /* So now we have dquots on the list... Just free them */
760 while (act_head != tofree_head) {
761 dquot = list_entry(act_head, struct dquot, dq_free);
762 act_head = act_head->next;
763 list_del_init(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */
764 dqput(dquot);
765 }
766}
767
Christoph Hellwigfb58b732007-02-12 00:51:57 -0800768static void remove_dquot_ref(struct super_block *sb, int type,
769 struct list_head *tofree_head)
770{
771 struct inode *inode;
772
773 spin_lock(&inode_lock);
774 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
775 if (!IS_NOQUOTA(inode))
776 remove_inode_dquot_ref(inode, type, tofree_head);
777 }
778 spin_unlock(&inode_lock);
779}
780
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781/* Gather all references from inodes and drop them */
782static void drop_dquot_ref(struct super_block *sb, int type)
783{
784 LIST_HEAD(tofree_head);
785
Christoph Hellwigfb58b732007-02-12 00:51:57 -0800786 if (sb->dq_op) {
787 down_write(&sb_dqopt(sb)->dqptr_sem);
788 remove_dquot_ref(sb, type, &tofree_head);
789 up_write(&sb_dqopt(sb)->dqptr_sem);
790 put_dquot_list(&tofree_head);
791 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792}
793
794static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number)
795{
796 dquot->dq_dqb.dqb_curinodes += number;
797}
798
799static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
800{
801 dquot->dq_dqb.dqb_curspace += number;
802}
803
804static inline void dquot_decr_inodes(struct dquot *dquot, unsigned long number)
805{
806 if (dquot->dq_dqb.dqb_curinodes > number)
807 dquot->dq_dqb.dqb_curinodes -= number;
808 else
809 dquot->dq_dqb.dqb_curinodes = 0;
810 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
811 dquot->dq_dqb.dqb_itime = (time_t) 0;
812 clear_bit(DQ_INODES_B, &dquot->dq_flags);
813}
814
815static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
816{
817 if (dquot->dq_dqb.dqb_curspace > number)
818 dquot->dq_dqb.dqb_curspace -= number;
819 else
820 dquot->dq_dqb.dqb_curspace = 0;
821 if (toqb(dquot->dq_dqb.dqb_curspace) <= dquot->dq_dqb.dqb_bsoftlimit)
822 dquot->dq_dqb.dqb_btime = (time_t) 0;
823 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
824}
825
826static int flag_print_warnings = 1;
827
828static inline int need_print_warning(struct dquot *dquot)
829{
830 if (!flag_print_warnings)
831 return 0;
832
833 switch (dquot->dq_type) {
834 case USRQUOTA:
835 return current->fsuid == dquot->dq_id;
836 case GRPQUOTA:
837 return in_group_p(dquot->dq_id);
838 }
839 return 0;
840}
841
842/* Values of warnings */
843#define NOWARN 0
844#define IHARDWARN 1
845#define ISOFTLONGWARN 2
846#define ISOFTWARN 3
847#define BHARDWARN 4
848#define BSOFTLONGWARN 5
849#define BSOFTWARN 6
850
851/* Print warning to user which exceeded quota */
852static void print_warning(struct dquot *dquot, const char warntype)
853{
854 char *msg = NULL;
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800855 struct tty_struct *tty;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 int flag = (warntype == BHARDWARN || warntype == BSOFTLONGWARN) ? DQ_BLKS_B :
857 ((warntype == IHARDWARN || warntype == ISOFTLONGWARN) ? DQ_INODES_B : 0);
858
859 if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags)))
860 return;
861
Jan Karab525a7e2006-09-29 02:00:26 -0700862 mutex_lock(&tty_mutex);
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800863 tty = get_current_tty();
864 if (!tty)
Jan Karab525a7e2006-09-29 02:00:26 -0700865 goto out_lock;
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800866 tty_write_message(tty, dquot->dq_sb->s_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 if (warntype == ISOFTWARN || warntype == BSOFTWARN)
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800868 tty_write_message(tty, ": warning, ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 else
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800870 tty_write_message(tty, ": write failed, ");
871 tty_write_message(tty, quotatypes[dquot->dq_type]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 switch (warntype) {
873 case IHARDWARN:
874 msg = " file limit reached.\r\n";
875 break;
876 case ISOFTLONGWARN:
877 msg = " file quota exceeded too long.\r\n";
878 break;
879 case ISOFTWARN:
880 msg = " file quota exceeded.\r\n";
881 break;
882 case BHARDWARN:
883 msg = " block limit reached.\r\n";
884 break;
885 case BSOFTLONGWARN:
886 msg = " block quota exceeded too long.\r\n";
887 break;
888 case BSOFTWARN:
889 msg = " block quota exceeded.\r\n";
890 break;
891 }
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800892 tty_write_message(tty, msg);
Jan Karab525a7e2006-09-29 02:00:26 -0700893out_lock:
894 mutex_unlock(&tty_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895}
896
897static inline void flush_warnings(struct dquot **dquots, char *warntype)
898{
899 int i;
900
901 for (i = 0; i < MAXQUOTAS; i++)
902 if (dquots[i] != NODQUOT && warntype[i] != NOWARN)
903 print_warning(dquots[i], warntype[i]);
904}
905
906static inline char ignore_hardlimit(struct dquot *dquot)
907{
908 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
909
910 return capable(CAP_SYS_RESOURCE) &&
911 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & V1_DQF_RSQUASH));
912}
913
914/* needs dq_data_lock */
915static int check_idq(struct dquot *dquot, ulong inodes, char *warntype)
916{
917 *warntype = NOWARN;
918 if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
919 return QUOTA_OK;
920
921 if (dquot->dq_dqb.dqb_ihardlimit &&
922 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit &&
923 !ignore_hardlimit(dquot)) {
924 *warntype = IHARDWARN;
925 return NO_QUOTA;
926 }
927
928 if (dquot->dq_dqb.dqb_isoftlimit &&
929 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
930 dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime &&
931 !ignore_hardlimit(dquot)) {
932 *warntype = ISOFTLONGWARN;
933 return NO_QUOTA;
934 }
935
936 if (dquot->dq_dqb.dqb_isoftlimit &&
937 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
938 dquot->dq_dqb.dqb_itime == 0) {
939 *warntype = ISOFTWARN;
940 dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
941 }
942
943 return QUOTA_OK;
944}
945
946/* needs dq_data_lock */
947static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
948{
949 *warntype = 0;
950 if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
951 return QUOTA_OK;
952
953 if (dquot->dq_dqb.dqb_bhardlimit &&
954 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bhardlimit &&
955 !ignore_hardlimit(dquot)) {
956 if (!prealloc)
957 *warntype = BHARDWARN;
958 return NO_QUOTA;
959 }
960
961 if (dquot->dq_dqb.dqb_bsoftlimit &&
962 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
963 dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime &&
964 !ignore_hardlimit(dquot)) {
965 if (!prealloc)
966 *warntype = BSOFTLONGWARN;
967 return NO_QUOTA;
968 }
969
970 if (dquot->dq_dqb.dqb_bsoftlimit &&
971 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
972 dquot->dq_dqb.dqb_btime == 0) {
973 if (!prealloc) {
974 *warntype = BSOFTWARN;
975 dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
976 }
977 else
978 /*
979 * We don't allow preallocation to exceed softlimit so exceeding will
980 * be always printed
981 */
982 return NO_QUOTA;
983 }
984
985 return QUOTA_OK;
986}
987
988/*
989 * Initialize quota pointers in inode
990 * Transaction must be started at entry
991 */
992int dquot_initialize(struct inode *inode, int type)
993{
994 unsigned int id = 0;
995 int cnt, ret = 0;
996
Ingo Molnard3be9152006-03-23 03:00:29 -0800997 /* First test before acquiring mutex - solves deadlocks when we
998 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999 if (IS_NOQUOTA(inode))
1000 return 0;
1001 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1002 /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
1003 if (IS_NOQUOTA(inode))
1004 goto out_err;
1005 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1006 if (type != -1 && cnt != type)
1007 continue;
1008 if (inode->i_dquot[cnt] == NODQUOT) {
1009 switch (cnt) {
1010 case USRQUOTA:
1011 id = inode->i_uid;
1012 break;
1013 case GRPQUOTA:
1014 id = inode->i_gid;
1015 break;
1016 }
1017 inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt);
1018 }
1019 }
1020out_err:
1021 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1022 return ret;
1023}
1024
1025/*
1026 * Release all quotas referenced by inode
1027 * Transaction must be started at an entry
1028 */
1029int dquot_drop(struct inode *inode)
1030{
1031 int cnt;
1032
1033 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1034 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1035 if (inode->i_dquot[cnt] != NODQUOT) {
1036 dqput(inode->i_dquot[cnt]);
1037 inode->i_dquot[cnt] = NODQUOT;
1038 }
1039 }
1040 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1041 return 0;
1042}
1043
1044/*
1045 * Following four functions update i_blocks+i_bytes fields and
1046 * quota information (together with appropriate checks)
1047 * NOTE: We absolutely rely on the fact that caller dirties
1048 * the inode (usually macros in quotaops.h care about this) and
1049 * holds a handle for the current transaction so that dquot write and
1050 * inode write go into the same transaction.
1051 */
1052
1053/*
1054 * This operation can block, but only after everything is updated
1055 */
1056int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1057{
1058 int cnt, ret = NO_QUOTA;
1059 char warntype[MAXQUOTAS];
1060
Ingo Molnard3be9152006-03-23 03:00:29 -08001061 /* First test before acquiring mutex - solves deadlocks when we
1062 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063 if (IS_NOQUOTA(inode)) {
1064out_add:
1065 inode_add_bytes(inode, number);
1066 return QUOTA_OK;
1067 }
1068 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1069 warntype[cnt] = NOWARN;
1070
1071 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1072 if (IS_NOQUOTA(inode)) { /* Now we can do reliable test... */
1073 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1074 goto out_add;
1075 }
1076 spin_lock(&dq_data_lock);
1077 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1078 if (inode->i_dquot[cnt] == NODQUOT)
1079 continue;
1080 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA)
1081 goto warn_put_all;
1082 }
1083 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1084 if (inode->i_dquot[cnt] == NODQUOT)
1085 continue;
1086 dquot_incr_space(inode->i_dquot[cnt], number);
1087 }
1088 inode_add_bytes(inode, number);
1089 ret = QUOTA_OK;
1090warn_put_all:
1091 spin_unlock(&dq_data_lock);
1092 if (ret == QUOTA_OK)
1093 /* Dirtify all the dquots - this can block when journalling */
1094 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1095 if (inode->i_dquot[cnt])
1096 mark_dquot_dirty(inode->i_dquot[cnt]);
1097 flush_warnings(inode->i_dquot, warntype);
1098 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1099 return ret;
1100}
1101
1102/*
1103 * This operation can block, but only after everything is updated
1104 */
1105int dquot_alloc_inode(const struct inode *inode, unsigned long number)
1106{
1107 int cnt, ret = NO_QUOTA;
1108 char warntype[MAXQUOTAS];
1109
Ingo Molnard3be9152006-03-23 03:00:29 -08001110 /* First test before acquiring mutex - solves deadlocks when we
1111 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112 if (IS_NOQUOTA(inode))
1113 return QUOTA_OK;
1114 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1115 warntype[cnt] = NOWARN;
1116 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1117 if (IS_NOQUOTA(inode)) {
1118 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1119 return QUOTA_OK;
1120 }
1121 spin_lock(&dq_data_lock);
1122 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1123 if (inode->i_dquot[cnt] == NODQUOT)
1124 continue;
1125 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA)
1126 goto warn_put_all;
1127 }
1128
1129 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1130 if (inode->i_dquot[cnt] == NODQUOT)
1131 continue;
1132 dquot_incr_inodes(inode->i_dquot[cnt], number);
1133 }
1134 ret = QUOTA_OK;
1135warn_put_all:
1136 spin_unlock(&dq_data_lock);
1137 if (ret == QUOTA_OK)
1138 /* Dirtify all the dquots - this can block when journalling */
1139 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1140 if (inode->i_dquot[cnt])
1141 mark_dquot_dirty(inode->i_dquot[cnt]);
1142 flush_warnings((struct dquot **)inode->i_dquot, warntype);
1143 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1144 return ret;
1145}
1146
1147/*
1148 * This operation can block, but only after everything is updated
1149 */
1150int dquot_free_space(struct inode *inode, qsize_t number)
1151{
1152 unsigned int cnt;
1153
Ingo Molnard3be9152006-03-23 03:00:29 -08001154 /* First test before acquiring mutex - solves deadlocks when we
1155 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 if (IS_NOQUOTA(inode)) {
1157out_sub:
1158 inode_sub_bytes(inode, number);
1159 return QUOTA_OK;
1160 }
1161 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1162 /* Now recheck reliably when holding dqptr_sem */
1163 if (IS_NOQUOTA(inode)) {
1164 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1165 goto out_sub;
1166 }
1167 spin_lock(&dq_data_lock);
1168 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1169 if (inode->i_dquot[cnt] == NODQUOT)
1170 continue;
1171 dquot_decr_space(inode->i_dquot[cnt], number);
1172 }
1173 inode_sub_bytes(inode, number);
1174 spin_unlock(&dq_data_lock);
1175 /* Dirtify all the dquots - this can block when journalling */
1176 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1177 if (inode->i_dquot[cnt])
1178 mark_dquot_dirty(inode->i_dquot[cnt]);
1179 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1180 return QUOTA_OK;
1181}
1182
1183/*
1184 * This operation can block, but only after everything is updated
1185 */
1186int dquot_free_inode(const struct inode *inode, unsigned long number)
1187{
1188 unsigned int cnt;
1189
Ingo Molnard3be9152006-03-23 03:00:29 -08001190 /* First test before acquiring mutex - solves deadlocks when we
1191 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 if (IS_NOQUOTA(inode))
1193 return QUOTA_OK;
1194 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1195 /* Now recheck reliably when holding dqptr_sem */
1196 if (IS_NOQUOTA(inode)) {
1197 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1198 return QUOTA_OK;
1199 }
1200 spin_lock(&dq_data_lock);
1201 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1202 if (inode->i_dquot[cnt] == NODQUOT)
1203 continue;
1204 dquot_decr_inodes(inode->i_dquot[cnt], number);
1205 }
1206 spin_unlock(&dq_data_lock);
1207 /* Dirtify all the dquots - this can block when journalling */
1208 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1209 if (inode->i_dquot[cnt])
1210 mark_dquot_dirty(inode->i_dquot[cnt]);
1211 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1212 return QUOTA_OK;
1213}
1214
1215/*
1216 * Transfer the number of inode and blocks from one diskquota to an other.
1217 *
1218 * This operation can block, but only after everything is updated
1219 * A transaction must be started when entering this function.
1220 */
1221int dquot_transfer(struct inode *inode, struct iattr *iattr)
1222{
1223 qsize_t space;
1224 struct dquot *transfer_from[MAXQUOTAS];
1225 struct dquot *transfer_to[MAXQUOTAS];
1226 int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid,
1227 chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid;
1228 char warntype[MAXQUOTAS];
1229
Ingo Molnard3be9152006-03-23 03:00:29 -08001230 /* First test before acquiring mutex - solves deadlocks when we
1231 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232 if (IS_NOQUOTA(inode))
1233 return QUOTA_OK;
1234 /* Clear the arrays */
1235 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1236 transfer_to[cnt] = transfer_from[cnt] = NODQUOT;
1237 warntype[cnt] = NOWARN;
1238 }
1239 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1240 /* Now recheck reliably when holding dqptr_sem */
1241 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */
1242 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1243 return QUOTA_OK;
1244 }
1245 /* First build the transfer_to list - here we can block on
1246 * reading/instantiating of dquots. We know that the transaction for
1247 * us was already started so we don't violate lock ranking here */
1248 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1249 switch (cnt) {
1250 case USRQUOTA:
1251 if (!chuid)
1252 continue;
1253 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt);
1254 break;
1255 case GRPQUOTA:
1256 if (!chgid)
1257 continue;
1258 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt);
1259 break;
1260 }
1261 }
1262 spin_lock(&dq_data_lock);
1263 space = inode_get_bytes(inode);
1264 /* Build the transfer_from list and check the limits */
1265 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1266 if (transfer_to[cnt] == NODQUOT)
1267 continue;
1268 transfer_from[cnt] = inode->i_dquot[cnt];
1269 if (check_idq(transfer_to[cnt], 1, warntype+cnt) == NO_QUOTA ||
1270 check_bdq(transfer_to[cnt], space, 0, warntype+cnt) == NO_QUOTA)
1271 goto warn_put_all;
1272 }
1273
1274 /*
1275 * Finally perform the needed transfer from transfer_from to transfer_to
1276 */
1277 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1278 /*
1279 * Skip changes for same uid or gid or for turned off quota-type.
1280 */
1281 if (transfer_to[cnt] == NODQUOT)
1282 continue;
1283
1284 /* Due to IO error we might not have transfer_from[] structure */
1285 if (transfer_from[cnt]) {
1286 dquot_decr_inodes(transfer_from[cnt], 1);
1287 dquot_decr_space(transfer_from[cnt], space);
1288 }
1289
1290 dquot_incr_inodes(transfer_to[cnt], 1);
1291 dquot_incr_space(transfer_to[cnt], space);
1292
1293 inode->i_dquot[cnt] = transfer_to[cnt];
1294 }
1295 ret = QUOTA_OK;
1296warn_put_all:
1297 spin_unlock(&dq_data_lock);
1298 /* Dirtify all the dquots - this can block when journalling */
1299 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1300 if (transfer_from[cnt])
1301 mark_dquot_dirty(transfer_from[cnt]);
1302 if (transfer_to[cnt])
1303 mark_dquot_dirty(transfer_to[cnt]);
1304 }
1305 flush_warnings(transfer_to, warntype);
1306
1307 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1308 if (ret == QUOTA_OK && transfer_from[cnt] != NODQUOT)
1309 dqput(transfer_from[cnt]);
1310 if (ret == NO_QUOTA && transfer_to[cnt] != NODQUOT)
1311 dqput(transfer_to[cnt]);
1312 }
1313 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1314 return ret;
1315}
1316
1317/*
1318 * Write info of quota file to disk
1319 */
1320int dquot_commit_info(struct super_block *sb, int type)
1321{
1322 int ret;
1323 struct quota_info *dqopt = sb_dqopt(sb);
1324
Ingo Molnard3be9152006-03-23 03:00:29 -08001325 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001326 ret = dqopt->ops[type]->write_file_info(sb, type);
Ingo Molnard3be9152006-03-23 03:00:29 -08001327 mutex_unlock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328 return ret;
1329}
1330
1331/*
1332 * Definitions of diskquota operations.
1333 */
1334struct dquot_operations dquot_operations = {
1335 .initialize = dquot_initialize,
1336 .drop = dquot_drop,
1337 .alloc_space = dquot_alloc_space,
1338 .alloc_inode = dquot_alloc_inode,
1339 .free_space = dquot_free_space,
1340 .free_inode = dquot_free_inode,
1341 .transfer = dquot_transfer,
1342 .write_dquot = dquot_commit,
1343 .acquire_dquot = dquot_acquire,
1344 .release_dquot = dquot_release,
1345 .mark_dirty = dquot_mark_dquot_dirty,
1346 .write_info = dquot_commit_info
1347};
1348
1349static inline void set_enable_flags(struct quota_info *dqopt, int type)
1350{
1351 switch (type) {
1352 case USRQUOTA:
1353 dqopt->flags |= DQUOT_USR_ENABLED;
1354 break;
1355 case GRPQUOTA:
1356 dqopt->flags |= DQUOT_GRP_ENABLED;
1357 break;
1358 }
1359}
1360
1361static inline void reset_enable_flags(struct quota_info *dqopt, int type)
1362{
1363 switch (type) {
1364 case USRQUOTA:
1365 dqopt->flags &= ~DQUOT_USR_ENABLED;
1366 break;
1367 case GRPQUOTA:
1368 dqopt->flags &= ~DQUOT_GRP_ENABLED;
1369 break;
1370 }
1371}
1372
1373/*
1374 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1375 */
1376int vfs_quota_off(struct super_block *sb, int type)
1377{
1378 int cnt;
1379 struct quota_info *dqopt = sb_dqopt(sb);
1380 struct inode *toputinode[MAXQUOTAS];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001381
1382 /* We need to serialize quota_off() for device */
Ingo Molnard3be9152006-03-23 03:00:29 -08001383 mutex_lock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1385 toputinode[cnt] = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386 if (type != -1 && cnt != type)
1387 continue;
1388 if (!sb_has_quota_enabled(sb, cnt))
1389 continue;
1390 reset_enable_flags(dqopt, cnt);
1391
1392 /* Note: these are blocking operations */
1393 drop_dquot_ref(sb, cnt);
1394 invalidate_dquots(sb, cnt);
1395 /*
1396 * Now all dquots should be invalidated, all writes done so we should be only
1397 * users of the info. No locks needed.
1398 */
1399 if (info_dirty(&dqopt->info[cnt]))
1400 sb->dq_op->write_info(sb, cnt);
1401 if (dqopt->ops[cnt]->free_file_info)
1402 dqopt->ops[cnt]->free_file_info(sb, cnt);
1403 put_quota_format(dqopt->info[cnt].dqi_format);
1404
1405 toputinode[cnt] = dqopt->files[cnt];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406 dqopt->files[cnt] = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 dqopt->info[cnt].dqi_flags = 0;
1408 dqopt->info[cnt].dqi_igrace = 0;
1409 dqopt->info[cnt].dqi_bgrace = 0;
1410 dqopt->ops[cnt] = NULL;
1411 }
Ingo Molnard3be9152006-03-23 03:00:29 -08001412 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413 /* Sync the superblock so that buffers with quota data are written to
Al Viro7b7b1ac2005-11-07 17:13:39 -05001414 * disk (and so userspace sees correct data afterwards). */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415 if (sb->s_op->sync_fs)
1416 sb->s_op->sync_fs(sb, 1);
1417 sync_blockdev(sb->s_bdev);
1418 /* Now the quota files are just ordinary files and we can set the
1419 * inode flags back. Moreover we discard the pagecache so that
1420 * userspace sees the writes we did bypassing the pagecache. We
1421 * must also discard the blockdev buffers so that we see the
1422 * changes done by userspace on the next quotaon() */
1423 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1424 if (toputinode[cnt]) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001425 mutex_lock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001426 /* If quota was reenabled in the meantime, we have
1427 * nothing to do */
1428 if (!sb_has_quota_enabled(sb, cnt)) {
Jan Kara79254092007-05-16 22:11:19 -07001429 mutex_lock_nested(&toputinode[cnt]->i_mutex, I_MUTEX_QUOTA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1431 S_NOATIME | S_NOQUOTA);
1432 truncate_inode_pages(&toputinode[cnt]->i_data, 0);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001433 mutex_unlock(&toputinode[cnt]->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 mark_inode_dirty(toputinode[cnt]);
1435 iput(toputinode[cnt]);
1436 }
Ingo Molnard3be9152006-03-23 03:00:29 -08001437 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438 }
1439 if (sb->s_bdev)
Peter Zijlstraf98393a2007-05-06 14:49:54 -07001440 invalidate_bdev(sb->s_bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 return 0;
1442}
1443
1444/*
1445 * Turn quotas on on a device
1446 */
1447
1448/* Helper function when we already have the inode */
1449static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
1450{
1451 struct quota_format_type *fmt = find_quota_format(format_id);
1452 struct super_block *sb = inode->i_sb;
1453 struct quota_info *dqopt = sb_dqopt(sb);
1454 int error;
1455 int oldflags = -1;
1456
1457 if (!fmt)
1458 return -ESRCH;
1459 if (!S_ISREG(inode->i_mode)) {
1460 error = -EACCES;
1461 goto out_fmt;
1462 }
1463 if (IS_RDONLY(inode)) {
1464 error = -EROFS;
1465 goto out_fmt;
1466 }
1467 if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
1468 error = -EINVAL;
1469 goto out_fmt;
1470 }
1471
1472 /* As we bypass the pagecache we must now flush the inode so that
1473 * we see all the changes from userspace... */
1474 write_inode_now(inode, 1);
1475 /* And now flush the block cache so that kernel sees the changes */
Peter Zijlstraf98393a2007-05-06 14:49:54 -07001476 invalidate_bdev(sb->s_bdev);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001477 mutex_lock(&inode->i_mutex);
Ingo Molnard3be9152006-03-23 03:00:29 -08001478 mutex_lock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479 if (sb_has_quota_enabled(sb, type)) {
1480 error = -EBUSY;
1481 goto out_lock;
1482 }
1483 /* We don't want quota and atime on quota files (deadlocks possible)
1484 * Also nobody should write to the file - we use special IO operations
1485 * which ignore the immutable bit. */
1486 down_write(&dqopt->dqptr_sem);
1487 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA);
1488 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
1489 up_write(&dqopt->dqptr_sem);
Jan Kara31e7ad62005-04-16 15:25:46 -07001490 sb->dq_op->drop(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001491
1492 error = -EIO;
1493 dqopt->files[type] = igrab(inode);
1494 if (!dqopt->files[type])
1495 goto out_lock;
1496 error = -EINVAL;
1497 if (!fmt->qf_ops->check_quota_file(sb, type))
1498 goto out_file_init;
1499
1500 dqopt->ops[type] = fmt->qf_ops;
1501 dqopt->info[type].dqi_format = fmt;
1502 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
Ingo Molnard3be9152006-03-23 03:00:29 -08001503 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001504 if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001505 mutex_unlock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506 goto out_file_init;
1507 }
Ingo Molnard3be9152006-03-23 03:00:29 -08001508 mutex_unlock(&dqopt->dqio_mutex);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001509 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510 set_enable_flags(dqopt, type);
1511
1512 add_dquot_ref(sb, type);
Ingo Molnard3be9152006-03-23 03:00:29 -08001513 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001514
1515 return 0;
1516
1517out_file_init:
1518 dqopt->files[type] = NULL;
1519 iput(inode);
1520out_lock:
Ingo Molnard3be9152006-03-23 03:00:29 -08001521 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001522 if (oldflags != -1) {
1523 down_write(&dqopt->dqptr_sem);
1524 /* Set the flags back (in the case of accidental quotaon()
1525 * on a wrong file we don't want to mess up the flags) */
1526 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
1527 inode->i_flags |= oldflags;
1528 up_write(&dqopt->dqptr_sem);
1529 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001530 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531out_fmt:
1532 put_quota_format(fmt);
1533
1534 return error;
1535}
1536
1537/* Actual function called from quotactl() */
1538int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path)
1539{
1540 struct nameidata nd;
1541 int error;
1542
1543 error = path_lookup(path, LOOKUP_FOLLOW, &nd);
1544 if (error < 0)
1545 return error;
1546 error = security_quota_on(nd.dentry);
1547 if (error)
1548 goto out_path;
1549 /* Quota file not on the same filesystem? */
1550 if (nd.mnt->mnt_sb != sb)
1551 error = -EXDEV;
Al Viro7b7b1ac2005-11-07 17:13:39 -05001552 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553 error = vfs_quota_on_inode(nd.dentry->d_inode, type, format_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001554out_path:
1555 path_release(&nd);
1556 return error;
1557}
1558
1559/*
1560 * This function is used when filesystem needs to initialize quotas
1561 * during mount time.
1562 */
Christoph Hellwig84de8562005-06-23 00:09:16 -07001563int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
1564 int format_id, int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565{
Christoph Hellwig84de8562005-06-23 00:09:16 -07001566 struct dentry *dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567 int error;
1568
Christoph Hellwig2fa389c2005-06-23 00:09:16 -07001569 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
Christoph Hellwig84de8562005-06-23 00:09:16 -07001570 if (IS_ERR(dentry))
1571 return PTR_ERR(dentry);
1572
Jan Kara154f4842005-11-28 13:44:14 -08001573 if (!dentry->d_inode) {
1574 error = -ENOENT;
1575 goto out;
1576 }
1577
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578 error = security_quota_on(dentry);
Christoph Hellwig84de8562005-06-23 00:09:16 -07001579 if (!error)
1580 error = vfs_quota_on_inode(dentry->d_inode, type, format_id);
1581
Jan Kara154f4842005-11-28 13:44:14 -08001582out:
Christoph Hellwig84de8562005-06-23 00:09:16 -07001583 dput(dentry);
1584 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585}
1586
1587/* Generic routine for getting common part of quota structure */
1588static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
1589{
1590 struct mem_dqblk *dm = &dquot->dq_dqb;
1591
1592 spin_lock(&dq_data_lock);
1593 di->dqb_bhardlimit = dm->dqb_bhardlimit;
1594 di->dqb_bsoftlimit = dm->dqb_bsoftlimit;
1595 di->dqb_curspace = dm->dqb_curspace;
1596 di->dqb_ihardlimit = dm->dqb_ihardlimit;
1597 di->dqb_isoftlimit = dm->dqb_isoftlimit;
1598 di->dqb_curinodes = dm->dqb_curinodes;
1599 di->dqb_btime = dm->dqb_btime;
1600 di->dqb_itime = dm->dqb_itime;
1601 di->dqb_valid = QIF_ALL;
1602 spin_unlock(&dq_data_lock);
1603}
1604
1605int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
1606{
1607 struct dquot *dquot;
1608
Ingo Molnard3be9152006-03-23 03:00:29 -08001609 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610 if (!(dquot = dqget(sb, id, type))) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001611 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612 return -ESRCH;
1613 }
1614 do_get_dqblk(dquot, di);
1615 dqput(dquot);
Ingo Molnard3be9152006-03-23 03:00:29 -08001616 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001617 return 0;
1618}
1619
1620/* Generic routine for setting common part of quota structure */
1621static void do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
1622{
1623 struct mem_dqblk *dm = &dquot->dq_dqb;
1624 int check_blim = 0, check_ilim = 0;
1625
1626 spin_lock(&dq_data_lock);
1627 if (di->dqb_valid & QIF_SPACE) {
1628 dm->dqb_curspace = di->dqb_curspace;
1629 check_blim = 1;
1630 }
1631 if (di->dqb_valid & QIF_BLIMITS) {
1632 dm->dqb_bsoftlimit = di->dqb_bsoftlimit;
1633 dm->dqb_bhardlimit = di->dqb_bhardlimit;
1634 check_blim = 1;
1635 }
1636 if (di->dqb_valid & QIF_INODES) {
1637 dm->dqb_curinodes = di->dqb_curinodes;
1638 check_ilim = 1;
1639 }
1640 if (di->dqb_valid & QIF_ILIMITS) {
1641 dm->dqb_isoftlimit = di->dqb_isoftlimit;
1642 dm->dqb_ihardlimit = di->dqb_ihardlimit;
1643 check_ilim = 1;
1644 }
1645 if (di->dqb_valid & QIF_BTIME)
1646 dm->dqb_btime = di->dqb_btime;
1647 if (di->dqb_valid & QIF_ITIME)
1648 dm->dqb_itime = di->dqb_itime;
1649
1650 if (check_blim) {
1651 if (!dm->dqb_bsoftlimit || toqb(dm->dqb_curspace) < dm->dqb_bsoftlimit) {
1652 dm->dqb_btime = 0;
1653 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1654 }
1655 else if (!(di->dqb_valid & QIF_BTIME)) /* Set grace only if user hasn't provided his own... */
1656 dm->dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
1657 }
1658 if (check_ilim) {
1659 if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) {
1660 dm->dqb_itime = 0;
1661 clear_bit(DQ_INODES_B, &dquot->dq_flags);
1662 }
1663 else if (!(di->dqb_valid & QIF_ITIME)) /* Set grace only if user hasn't provided his own... */
1664 dm->dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1665 }
1666 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit)
1667 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
1668 else
1669 set_bit(DQ_FAKE_B, &dquot->dq_flags);
1670 spin_unlock(&dq_data_lock);
1671 mark_dquot_dirty(dquot);
1672}
1673
1674int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
1675{
1676 struct dquot *dquot;
1677
Ingo Molnard3be9152006-03-23 03:00:29 -08001678 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679 if (!(dquot = dqget(sb, id, type))) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001680 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681 return -ESRCH;
1682 }
1683 do_set_dqblk(dquot, di);
1684 dqput(dquot);
Ingo Molnard3be9152006-03-23 03:00:29 -08001685 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001686 return 0;
1687}
1688
1689/* Generic routine for getting common part of quota file information */
1690int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
1691{
1692 struct mem_dqinfo *mi;
1693
Ingo Molnard3be9152006-03-23 03:00:29 -08001694 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001695 if (!sb_has_quota_enabled(sb, type)) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001696 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001697 return -ESRCH;
1698 }
1699 mi = sb_dqopt(sb)->info + type;
1700 spin_lock(&dq_data_lock);
1701 ii->dqi_bgrace = mi->dqi_bgrace;
1702 ii->dqi_igrace = mi->dqi_igrace;
1703 ii->dqi_flags = mi->dqi_flags & DQF_MASK;
1704 ii->dqi_valid = IIF_ALL;
1705 spin_unlock(&dq_data_lock);
Ingo Molnard3be9152006-03-23 03:00:29 -08001706 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001707 return 0;
1708}
1709
1710/* Generic routine for setting common part of quota file information */
1711int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
1712{
1713 struct mem_dqinfo *mi;
1714
Ingo Molnard3be9152006-03-23 03:00:29 -08001715 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001716 if (!sb_has_quota_enabled(sb, type)) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001717 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718 return -ESRCH;
1719 }
1720 mi = sb_dqopt(sb)->info + type;
1721 spin_lock(&dq_data_lock);
1722 if (ii->dqi_valid & IIF_BGRACE)
1723 mi->dqi_bgrace = ii->dqi_bgrace;
1724 if (ii->dqi_valid & IIF_IGRACE)
1725 mi->dqi_igrace = ii->dqi_igrace;
1726 if (ii->dqi_valid & IIF_FLAGS)
1727 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | (ii->dqi_flags & DQF_MASK);
1728 spin_unlock(&dq_data_lock);
1729 mark_info_dirty(sb, type);
1730 /* Force write to disk */
1731 sb->dq_op->write_info(sb, type);
Ingo Molnard3be9152006-03-23 03:00:29 -08001732 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733 return 0;
1734}
1735
1736struct quotactl_ops vfs_quotactl_ops = {
1737 .quota_on = vfs_quota_on,
1738 .quota_off = vfs_quota_off,
1739 .quota_sync = vfs_quota_sync,
1740 .get_info = vfs_get_dqinfo,
1741 .set_info = vfs_set_dqinfo,
1742 .get_dqblk = vfs_get_dqblk,
1743 .set_dqblk = vfs_set_dqblk
1744};
1745
1746static ctl_table fs_dqstats_table[] = {
1747 {
1748 .ctl_name = FS_DQ_LOOKUPS,
1749 .procname = "lookups",
1750 .data = &dqstats.lookups,
1751 .maxlen = sizeof(int),
1752 .mode = 0444,
1753 .proc_handler = &proc_dointvec,
1754 },
1755 {
1756 .ctl_name = FS_DQ_DROPS,
1757 .procname = "drops",
1758 .data = &dqstats.drops,
1759 .maxlen = sizeof(int),
1760 .mode = 0444,
1761 .proc_handler = &proc_dointvec,
1762 },
1763 {
1764 .ctl_name = FS_DQ_READS,
1765 .procname = "reads",
1766 .data = &dqstats.reads,
1767 .maxlen = sizeof(int),
1768 .mode = 0444,
1769 .proc_handler = &proc_dointvec,
1770 },
1771 {
1772 .ctl_name = FS_DQ_WRITES,
1773 .procname = "writes",
1774 .data = &dqstats.writes,
1775 .maxlen = sizeof(int),
1776 .mode = 0444,
1777 .proc_handler = &proc_dointvec,
1778 },
1779 {
1780 .ctl_name = FS_DQ_CACHE_HITS,
1781 .procname = "cache_hits",
1782 .data = &dqstats.cache_hits,
1783 .maxlen = sizeof(int),
1784 .mode = 0444,
1785 .proc_handler = &proc_dointvec,
1786 },
1787 {
1788 .ctl_name = FS_DQ_ALLOCATED,
1789 .procname = "allocated_dquots",
1790 .data = &dqstats.allocated_dquots,
1791 .maxlen = sizeof(int),
1792 .mode = 0444,
1793 .proc_handler = &proc_dointvec,
1794 },
1795 {
1796 .ctl_name = FS_DQ_FREE,
1797 .procname = "free_dquots",
1798 .data = &dqstats.free_dquots,
1799 .maxlen = sizeof(int),
1800 .mode = 0444,
1801 .proc_handler = &proc_dointvec,
1802 },
1803 {
1804 .ctl_name = FS_DQ_SYNCS,
1805 .procname = "syncs",
1806 .data = &dqstats.syncs,
1807 .maxlen = sizeof(int),
1808 .mode = 0444,
1809 .proc_handler = &proc_dointvec,
1810 },
1811 {
1812 .ctl_name = FS_DQ_WARNINGS,
1813 .procname = "warnings",
1814 .data = &flag_print_warnings,
1815 .maxlen = sizeof(int),
1816 .mode = 0644,
1817 .proc_handler = &proc_dointvec,
1818 },
1819 { .ctl_name = 0 },
1820};
1821
1822static ctl_table fs_table[] = {
1823 {
1824 .ctl_name = FS_DQSTATS,
1825 .procname = "quota",
1826 .mode = 0555,
1827 .child = fs_dqstats_table,
1828 },
1829 { .ctl_name = 0 },
1830};
1831
1832static ctl_table sys_table[] = {
1833 {
1834 .ctl_name = CTL_FS,
1835 .procname = "fs",
1836 .mode = 0555,
1837 .child = fs_table,
1838 },
1839 { .ctl_name = 0 },
1840};
1841
1842static int __init dquot_init(void)
1843{
1844 int i;
1845 unsigned long nr_hash, order;
1846
1847 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
1848
Eric W. Biederman0b4d4142007-02-14 00:34:09 -08001849 register_sysctl_table(sys_table);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001850
1851 dquot_cachep = kmem_cache_create("dquot",
1852 sizeof(struct dquot), sizeof(unsigned long) * 4,
Paul Jacksonfffb60f2006-03-24 03:16:06 -08001853 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1854 SLAB_MEM_SPREAD|SLAB_PANIC),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001855 NULL, NULL);
1856
1857 order = 0;
1858 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
1859 if (!dquot_hash)
1860 panic("Cannot create dquot hash table");
1861
1862 /* Find power-of-two hlist_heads which can fit into allocation */
1863 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
1864 dq_hash_bits = 0;
1865 do {
1866 dq_hash_bits++;
1867 } while (nr_hash >> dq_hash_bits);
1868 dq_hash_bits--;
1869
1870 nr_hash = 1UL << dq_hash_bits;
1871 dq_hash_mask = nr_hash - 1;
1872 for (i = 0; i < nr_hash; i++)
1873 INIT_HLIST_HEAD(dquot_hash + i);
1874
1875 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
1876 nr_hash, order, (PAGE_SIZE << order));
1877
Rusty Russell8e1f9362007-07-17 04:03:17 -07001878 register_shrinker(&dqcache_shrinker);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879
1880 return 0;
1881}
1882module_init(dquot_init);
1883
1884EXPORT_SYMBOL(register_quota_format);
1885EXPORT_SYMBOL(unregister_quota_format);
1886EXPORT_SYMBOL(dqstats);
1887EXPORT_SYMBOL(dq_data_lock);
1888EXPORT_SYMBOL(vfs_quota_on);
1889EXPORT_SYMBOL(vfs_quota_on_mount);
1890EXPORT_SYMBOL(vfs_quota_off);
1891EXPORT_SYMBOL(vfs_quota_sync);
1892EXPORT_SYMBOL(vfs_get_dqinfo);
1893EXPORT_SYMBOL(vfs_set_dqinfo);
1894EXPORT_SYMBOL(vfs_get_dqblk);
1895EXPORT_SYMBOL(vfs_set_dqblk);
1896EXPORT_SYMBOL(dquot_commit);
1897EXPORT_SYMBOL(dquot_commit_info);
1898EXPORT_SYMBOL(dquot_acquire);
1899EXPORT_SYMBOL(dquot_release);
1900EXPORT_SYMBOL(dquot_mark_dquot_dirty);
1901EXPORT_SYMBOL(dquot_initialize);
1902EXPORT_SYMBOL(dquot_drop);
1903EXPORT_SYMBOL(dquot_alloc_space);
1904EXPORT_SYMBOL(dquot_alloc_inode);
1905EXPORT_SYMBOL(dquot_free_space);
1906EXPORT_SYMBOL(dquot_free_inode);
1907EXPORT_SYMBOL(dquot_transfer);