blob: 2809768d9c4106e20f14d75ab86ccc408ea689c5 [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.. */
Jan Kara8e893462007-10-16 23:29:31 -070082#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
83#include <net/netlink.h>
84#include <net/genetlink.h>
85#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
87#include <asm/uaccess.h>
88
89#define __DQUOT_PARANOIA
90
91/*
92 * There are two quota SMP locks. dq_list_lock protects all lists with quotas
93 * and quota formats and also dqstats structure containing statistics about the
94 * lists. dq_data_lock protects data from dq_dqb and also mem_dqinfo structures
95 * and also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
96 * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
97 * in inode_add_bytes() and inode_sub_bytes().
98 *
99 * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock
100 *
101 * Note that some things (eg. sb pointer, type, id) doesn't change during
102 * the life of the dquot structure and so needn't to be protected by a lock
103 *
104 * Any operation working on dquots via inode pointers must hold dqptr_sem. If
105 * operation is just reading pointers from inode (or not using them at all) the
106 * read lock is enough. If pointers are altered function must hold write lock
107 * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800108 * for altering the flag i_mutex is also needed). If operation is holding
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 * reference to dquot in other way (e.g. quotactl ops) it must be guarded by
Ingo Molnard3be9152006-03-23 03:00:29 -0800110 * dqonoff_mutex.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 * This locking assures that:
112 * a) update/access to dquot pointers in inode is serialized
113 * b) everyone is guarded against invalidate_dquots()
114 *
Ingo Molnard3be9152006-03-23 03:00:29 -0800115 * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 * from inodes (dquot_alloc_space() and such don't check the dq_lock).
117 * Currently dquot is locked only when it is being read to memory (or space for
118 * it is being allocated) on the first dqget() and when it is being released on
119 * the last dqput(). The allocation and release oparations are serialized by
120 * the dq_lock and by checking the use count in dquot_release(). Write
121 * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
122 * spinlock to internal buffers before writing.
123 *
124 * Lock ordering (including related VFS locks) is the following:
Ingo Molnard3be9152006-03-23 03:00:29 -0800125 * i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
126 * dqio_mutex
127 * i_mutex on quota files is special (it's below dqio_mutex)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 */
129
130static DEFINE_SPINLOCK(dq_list_lock);
131DEFINE_SPINLOCK(dq_data_lock);
132
133static char *quotatypes[] = INITQFNAMES;
134static struct quota_format_type *quota_formats; /* List of registered formats */
135static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
136
137/* SLAB cache for dquot structures */
Christoph Lametere18b8902006-12-06 20:33:20 -0800138static struct kmem_cache *dquot_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
140int register_quota_format(struct quota_format_type *fmt)
141{
142 spin_lock(&dq_list_lock);
143 fmt->qf_next = quota_formats;
144 quota_formats = fmt;
145 spin_unlock(&dq_list_lock);
146 return 0;
147}
148
149void unregister_quota_format(struct quota_format_type *fmt)
150{
151 struct quota_format_type **actqf;
152
153 spin_lock(&dq_list_lock);
154 for (actqf = &quota_formats; *actqf && *actqf != fmt; actqf = &(*actqf)->qf_next);
155 if (*actqf)
156 *actqf = (*actqf)->qf_next;
157 spin_unlock(&dq_list_lock);
158}
159
160static struct quota_format_type *find_quota_format(int id)
161{
162 struct quota_format_type *actqf;
163
164 spin_lock(&dq_list_lock);
165 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
166 if (!actqf || !try_module_get(actqf->qf_owner)) {
167 int qm;
168
169 spin_unlock(&dq_list_lock);
170
171 for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++);
172 if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name))
173 return NULL;
174
175 spin_lock(&dq_list_lock);
176 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
177 if (actqf && !try_module_get(actqf->qf_owner))
178 actqf = NULL;
179 }
180 spin_unlock(&dq_list_lock);
181 return actqf;
182}
183
184static void put_quota_format(struct quota_format_type *fmt)
185{
186 module_put(fmt->qf_owner);
187}
188
189/*
190 * Dquot List Management:
191 * The quota code uses three lists for dquot management: the inuse_list,
192 * free_dquots, and dquot_hash[] array. A single dquot structure may be
193 * on all three lists, depending on its current state.
194 *
195 * All dquots are placed to the end of inuse_list when first created, and this
196 * list is used for invalidate operation, which must look at every dquot.
197 *
198 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
199 * and this list is searched whenever we need an available dquot. Dquots are
200 * removed from the list as soon as they are used again, and
201 * dqstats.free_dquots gives the number of dquots on the list. When
202 * dquot is invalidated it's completely released from memory.
203 *
204 * Dquots with a specific identity (device, type and id) are placed on
205 * one of the dquot_hash[] hash chains. The provides an efficient search
206 * mechanism to locate a specific dquot.
207 */
208
209static LIST_HEAD(inuse_list);
210static LIST_HEAD(free_dquots);
211static unsigned int dq_hash_bits, dq_hash_mask;
212static struct hlist_head *dquot_hash;
213
214struct dqstats dqstats;
215
216static void dqput(struct dquot *dquot);
217
218static inline unsigned int
219hashfn(const struct super_block *sb, unsigned int id, int type)
220{
221 unsigned long tmp;
222
223 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
224 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
225}
226
227/*
228 * Following list functions expect dq_list_lock to be held
229 */
230static inline void insert_dquot_hash(struct dquot *dquot)
231{
232 struct hlist_head *head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
233 hlist_add_head(&dquot->dq_hash, head);
234}
235
236static inline void remove_dquot_hash(struct dquot *dquot)
237{
238 hlist_del_init(&dquot->dq_hash);
239}
240
241static inline struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, unsigned int id, int type)
242{
243 struct hlist_node *node;
244 struct dquot *dquot;
245
246 hlist_for_each (node, dquot_hash+hashent) {
247 dquot = hlist_entry(node, struct dquot, dq_hash);
248 if (dquot->dq_sb == sb && dquot->dq_id == id && dquot->dq_type == type)
249 return dquot;
250 }
251 return NODQUOT;
252}
253
254/* Add a dquot to the tail of the free list */
255static inline void put_dquot_last(struct dquot *dquot)
256{
Akinobu Mita8e130592006-06-26 00:24:37 -0700257 list_add_tail(&dquot->dq_free, &free_dquots);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 dqstats.free_dquots++;
259}
260
261static inline void remove_free_dquot(struct dquot *dquot)
262{
263 if (list_empty(&dquot->dq_free))
264 return;
265 list_del_init(&dquot->dq_free);
266 dqstats.free_dquots--;
267}
268
269static inline void put_inuse(struct dquot *dquot)
270{
271 /* We add to the back of inuse list so we don't have to restart
272 * when traversing this list and we block */
Akinobu Mita8e130592006-06-26 00:24:37 -0700273 list_add_tail(&dquot->dq_inuse, &inuse_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 dqstats.allocated_dquots++;
275}
276
277static inline void remove_inuse(struct dquot *dquot)
278{
279 dqstats.allocated_dquots--;
280 list_del(&dquot->dq_inuse);
281}
282/*
283 * End of list functions needing dq_list_lock
284 */
285
286static void wait_on_dquot(struct dquot *dquot)
287{
Ingo Molnard3be9152006-03-23 03:00:29 -0800288 mutex_lock(&dquot->dq_lock);
289 mutex_unlock(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290}
291
292#define mark_dquot_dirty(dquot) ((dquot)->dq_sb->dq_op->mark_dirty(dquot))
293
294int dquot_mark_dquot_dirty(struct dquot *dquot)
295{
296 spin_lock(&dq_list_lock);
297 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
298 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
299 info[dquot->dq_type].dqi_dirty_list);
300 spin_unlock(&dq_list_lock);
301 return 0;
302}
303
304/* This function needs dq_list_lock */
305static inline int clear_dquot_dirty(struct dquot *dquot)
306{
307 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
308 return 0;
309 list_del_init(&dquot->dq_dirty);
310 return 1;
311}
312
313void mark_info_dirty(struct super_block *sb, int type)
314{
315 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
316}
317EXPORT_SYMBOL(mark_info_dirty);
318
319/*
320 * Read dquot from disk and alloc space for it
321 */
322
323int dquot_acquire(struct dquot *dquot)
324{
325 int ret = 0, ret2 = 0;
326 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
327
Ingo Molnard3be9152006-03-23 03:00:29 -0800328 mutex_lock(&dquot->dq_lock);
329 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 if (!test_bit(DQ_READ_B, &dquot->dq_flags))
331 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
332 if (ret < 0)
333 goto out_iolock;
334 set_bit(DQ_READ_B, &dquot->dq_flags);
335 /* Instantiate dquot if needed */
336 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
337 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
338 /* Write the info if needed */
339 if (info_dirty(&dqopt->info[dquot->dq_type]))
340 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
341 if (ret < 0)
342 goto out_iolock;
343 if (ret2 < 0) {
344 ret = ret2;
345 goto out_iolock;
346 }
347 }
348 set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
349out_iolock:
Ingo Molnard3be9152006-03-23 03:00:29 -0800350 mutex_unlock(&dqopt->dqio_mutex);
351 mutex_unlock(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 return ret;
353}
354
355/*
356 * Write dquot to disk
357 */
358int dquot_commit(struct dquot *dquot)
359{
360 int ret = 0, ret2 = 0;
361 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
362
Ingo Molnard3be9152006-03-23 03:00:29 -0800363 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 spin_lock(&dq_list_lock);
365 if (!clear_dquot_dirty(dquot)) {
366 spin_unlock(&dq_list_lock);
367 goto out_sem;
368 }
369 spin_unlock(&dq_list_lock);
370 /* Inactive dquot can be only if there was error during read/init
371 * => we have better not writing it */
372 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
373 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
374 if (info_dirty(&dqopt->info[dquot->dq_type]))
375 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
376 if (ret >= 0)
377 ret = ret2;
378 }
379out_sem:
Ingo Molnard3be9152006-03-23 03:00:29 -0800380 mutex_unlock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 return ret;
382}
383
384/*
385 * Release dquot
386 */
387int dquot_release(struct dquot *dquot)
388{
389 int ret = 0, ret2 = 0;
390 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
391
Ingo Molnard3be9152006-03-23 03:00:29 -0800392 mutex_lock(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 /* Check whether we are not racing with some other dqget() */
394 if (atomic_read(&dquot->dq_count) > 1)
395 goto out_dqlock;
Ingo Molnard3be9152006-03-23 03:00:29 -0800396 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 if (dqopt->ops[dquot->dq_type]->release_dqblk) {
398 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
399 /* Write the info */
400 if (info_dirty(&dqopt->info[dquot->dq_type]))
401 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
402 if (ret >= 0)
403 ret = ret2;
404 }
405 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
Ingo Molnard3be9152006-03-23 03:00:29 -0800406 mutex_unlock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407out_dqlock:
Ingo Molnard3be9152006-03-23 03:00:29 -0800408 mutex_unlock(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 return ret;
410}
411
412/* Invalidate all dquots on the list. Note that this function is called after
413 * quota is disabled and pointers from inodes removed so there cannot be new
Jan Kara6362e4d2006-03-23 03:00:17 -0800414 * quota users. There can still be some users of quotas due to inodes being
415 * just deleted or pruned by prune_icache() (those are not attached to any
416 * list). We have to wait for such users.
417 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418static void invalidate_dquots(struct super_block *sb, int type)
419{
Domen Puncerc33ed272005-06-25 14:59:36 -0700420 struct dquot *dquot, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421
Jan Kara6362e4d2006-03-23 03:00:17 -0800422restart:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 spin_lock(&dq_list_lock);
Domen Puncerc33ed272005-06-25 14:59:36 -0700424 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 if (dquot->dq_sb != sb)
426 continue;
427 if (dquot->dq_type != type)
428 continue;
Jan Kara6362e4d2006-03-23 03:00:17 -0800429 /* Wait for dquot users */
430 if (atomic_read(&dquot->dq_count)) {
431 DEFINE_WAIT(wait);
432
433 atomic_inc(&dquot->dq_count);
434 prepare_to_wait(&dquot->dq_wait_unused, &wait,
435 TASK_UNINTERRUPTIBLE);
436 spin_unlock(&dq_list_lock);
437 /* Once dqput() wakes us up, we know it's time to free
438 * the dquot.
439 * IMPORTANT: we rely on the fact that there is always
440 * at most one process waiting for dquot to free.
441 * Otherwise dq_count would be > 1 and we would never
442 * wake up.
443 */
444 if (atomic_read(&dquot->dq_count) > 1)
445 schedule();
446 finish_wait(&dquot->dq_wait_unused, &wait);
447 dqput(dquot);
448 /* At this moment dquot() need not exist (it could be
449 * reclaimed by prune_dqcache(). Hence we must
450 * restart. */
451 goto restart;
452 }
453 /*
454 * Quota now has no users and it has been written on last
455 * dqput()
456 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 remove_dquot_hash(dquot);
458 remove_free_dquot(dquot);
459 remove_inuse(dquot);
460 kmem_cache_free(dquot_cachep, dquot);
461 }
462 spin_unlock(&dq_list_lock);
463}
464
465int vfs_quota_sync(struct super_block *sb, int type)
466{
467 struct list_head *dirty;
468 struct dquot *dquot;
469 struct quota_info *dqopt = sb_dqopt(sb);
470 int cnt;
471
Ingo Molnard3be9152006-03-23 03:00:29 -0800472 mutex_lock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
474 if (type != -1 && cnt != type)
475 continue;
476 if (!sb_has_quota_enabled(sb, cnt))
477 continue;
478 spin_lock(&dq_list_lock);
479 dirty = &dqopt->info[cnt].dqi_dirty_list;
480 while (!list_empty(dirty)) {
Pavel Emelianovb5e61812007-05-08 00:30:19 -0700481 dquot = list_first_entry(dirty, struct dquot, dq_dirty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 /* Dirty and inactive can be only bad dquot... */
483 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
484 clear_dquot_dirty(dquot);
485 continue;
486 }
487 /* Now we have active dquot from which someone is
488 * holding reference so we can safely just increase
489 * use count */
490 atomic_inc(&dquot->dq_count);
491 dqstats.lookups++;
492 spin_unlock(&dq_list_lock);
493 sb->dq_op->write_dquot(dquot);
494 dqput(dquot);
495 spin_lock(&dq_list_lock);
496 }
497 spin_unlock(&dq_list_lock);
498 }
499
500 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
501 if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt)
502 && info_dirty(&dqopt->info[cnt]))
503 sb->dq_op->write_info(sb, cnt);
504 spin_lock(&dq_list_lock);
505 dqstats.syncs++;
506 spin_unlock(&dq_list_lock);
Ingo Molnard3be9152006-03-23 03:00:29 -0800507 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
509 return 0;
510}
511
512/* Free unused dquots from cache */
513static void prune_dqcache(int count)
514{
515 struct list_head *head;
516 struct dquot *dquot;
517
518 head = free_dquots.prev;
519 while (head != &free_dquots && count) {
520 dquot = list_entry(head, struct dquot, dq_free);
521 remove_dquot_hash(dquot);
522 remove_free_dquot(dquot);
523 remove_inuse(dquot);
524 kmem_cache_free(dquot_cachep, dquot);
525 count--;
526 head = free_dquots.prev;
527 }
528}
529
530/*
531 * This is called from kswapd when we think we need some
532 * more memory
533 */
534
Al Viro27496a82005-10-21 03:20:48 -0400535static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536{
537 if (nr) {
538 spin_lock(&dq_list_lock);
539 prune_dqcache(nr);
540 spin_unlock(&dq_list_lock);
541 }
542 return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
543}
544
Rusty Russell8e1f9362007-07-17 04:03:17 -0700545static struct shrinker dqcache_shrinker = {
546 .shrink = shrink_dqcache_memory,
547 .seeks = DEFAULT_SEEKS,
548};
549
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550/*
551 * Put reference to dquot
552 * NOTE: If you change this function please check whether dqput_blocks() works right...
Ingo Molnard3be9152006-03-23 03:00:29 -0800553 * MUST be called with either dqptr_sem or dqonoff_mutex held
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 */
555static void dqput(struct dquot *dquot)
556{
557 if (!dquot)
558 return;
559#ifdef __DQUOT_PARANOIA
560 if (!atomic_read(&dquot->dq_count)) {
561 printk("VFS: dqput: trying to free free dquot\n");
562 printk("VFS: device %s, dquot of %s %d\n",
563 dquot->dq_sb->s_id,
564 quotatypes[dquot->dq_type],
565 dquot->dq_id);
566 BUG();
567 }
568#endif
569
570 spin_lock(&dq_list_lock);
571 dqstats.drops++;
572 spin_unlock(&dq_list_lock);
573we_slept:
574 spin_lock(&dq_list_lock);
575 if (atomic_read(&dquot->dq_count) > 1) {
576 /* We have more than one user... nothing to do */
577 atomic_dec(&dquot->dq_count);
Jan Kara6362e4d2006-03-23 03:00:17 -0800578 /* Releasing dquot during quotaoff phase? */
579 if (!sb_has_quota_enabled(dquot->dq_sb, dquot->dq_type) &&
580 atomic_read(&dquot->dq_count) == 1)
581 wake_up(&dquot->dq_wait_unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 spin_unlock(&dq_list_lock);
583 return;
584 }
585 /* Need to release dquot? */
586 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
587 spin_unlock(&dq_list_lock);
588 /* Commit dquot before releasing */
589 dquot->dq_sb->dq_op->write_dquot(dquot);
590 goto we_slept;
591 }
592 /* Clear flag in case dquot was inactive (something bad happened) */
593 clear_dquot_dirty(dquot);
594 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
595 spin_unlock(&dq_list_lock);
596 dquot->dq_sb->dq_op->release_dquot(dquot);
597 goto we_slept;
598 }
599 atomic_dec(&dquot->dq_count);
600#ifdef __DQUOT_PARANOIA
601 /* sanity check */
Eric Sesterhenn8abf6a42006-04-02 13:36:13 +0200602 BUG_ON(!list_empty(&dquot->dq_free));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603#endif
604 put_dquot_last(dquot);
605 spin_unlock(&dq_list_lock);
606}
607
608static struct dquot *get_empty_dquot(struct super_block *sb, int type)
609{
610 struct dquot *dquot;
611
Robert P. J. Dayc3762222007-02-10 01:45:03 -0800612 dquot = kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 if(!dquot)
614 return NODQUOT;
615
Ingo Molnard3be9152006-03-23 03:00:29 -0800616 mutex_init(&dquot->dq_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 INIT_LIST_HEAD(&dquot->dq_free);
618 INIT_LIST_HEAD(&dquot->dq_inuse);
619 INIT_HLIST_NODE(&dquot->dq_hash);
620 INIT_LIST_HEAD(&dquot->dq_dirty);
Jan Kara6362e4d2006-03-23 03:00:17 -0800621 init_waitqueue_head(&dquot->dq_wait_unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 dquot->dq_sb = sb;
623 dquot->dq_type = type;
624 atomic_set(&dquot->dq_count, 1);
625
626 return dquot;
627}
628
629/*
630 * Get reference to dquot
Ingo Molnard3be9152006-03-23 03:00:29 -0800631 * MUST be called with either dqptr_sem or dqonoff_mutex held
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 */
633static struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
634{
635 unsigned int hashent = hashfn(sb, id, type);
636 struct dquot *dquot, *empty = NODQUOT;
637
638 if (!sb_has_quota_enabled(sb, type))
639 return NODQUOT;
640we_slept:
641 spin_lock(&dq_list_lock);
642 if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) {
643 if (empty == NODQUOT) {
644 spin_unlock(&dq_list_lock);
645 if ((empty = get_empty_dquot(sb, type)) == NODQUOT)
646 schedule(); /* Try to wait for a moment... */
647 goto we_slept;
648 }
649 dquot = empty;
650 dquot->dq_id = id;
651 /* all dquots go on the inuse_list */
652 put_inuse(dquot);
653 /* hash it first so it can be found */
654 insert_dquot_hash(dquot);
655 dqstats.lookups++;
656 spin_unlock(&dq_list_lock);
657 } else {
658 if (!atomic_read(&dquot->dq_count))
659 remove_free_dquot(dquot);
660 atomic_inc(&dquot->dq_count);
661 dqstats.cache_hits++;
662 dqstats.lookups++;
663 spin_unlock(&dq_list_lock);
664 if (empty)
665 kmem_cache_free(dquot_cachep, empty);
666 }
667 /* Wait for dq_lock - after this we know that either dquot_release() is already
668 * finished or it will be canceled due to dq_count > 1 test */
669 wait_on_dquot(dquot);
670 /* Read the dquot and instantiate it (everything done only if needed) */
671 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
672 dqput(dquot);
673 return NODQUOT;
674 }
675#ifdef __DQUOT_PARANOIA
Eric Sesterhenn8abf6a42006-04-02 13:36:13 +0200676 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677#endif
678
679 return dquot;
680}
681
682static int dqinit_needed(struct inode *inode, int type)
683{
684 int cnt;
685
686 if (IS_NOQUOTA(inode))
687 return 0;
688 if (type != -1)
689 return inode->i_dquot[type] == NODQUOT;
690 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
691 if (inode->i_dquot[cnt] == NODQUOT)
692 return 1;
693 return 0;
694}
695
Ingo Molnard3be9152006-03-23 03:00:29 -0800696/* This routine is guarded by dqonoff_mutex mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697static void add_dquot_ref(struct super_block *sb, int type)
698{
Christoph Hellwigd003fb72007-02-12 00:51:58 -0800699 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700
701restart:
Christoph Hellwigd003fb72007-02-12 00:51:58 -0800702 spin_lock(&inode_lock);
703 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
704 if (!atomic_read(&inode->i_writecount))
705 continue;
706 if (!dqinit_needed(inode, type))
707 continue;
708 if (inode->i_state & (I_FREEING|I_WILL_FREE))
709 continue;
710
711 __iget(inode);
712 spin_unlock(&inode_lock);
713
714 sb->dq_op->initialize(inode, type);
715 iput(inode);
716 /* As we may have blocked we had better restart... */
717 goto restart;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 }
Christoph Hellwigd003fb72007-02-12 00:51:58 -0800719 spin_unlock(&inode_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720}
721
722/* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */
723static inline int dqput_blocks(struct dquot *dquot)
724{
725 if (atomic_read(&dquot->dq_count) <= 1)
726 return 1;
727 return 0;
728}
729
730/* Remove references to dquots from inode - add dquot to list for freeing if needed */
731/* We can't race with anybody because we hold dqptr_sem for writing... */
Adrian Bunke5f00f42007-05-08 00:27:22 -0700732static int remove_inode_dquot_ref(struct inode *inode, int type,
733 struct list_head *tofree_head)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734{
735 struct dquot *dquot = inode->i_dquot[type];
736
737 inode->i_dquot[type] = NODQUOT;
738 if (dquot != NODQUOT) {
739 if (dqput_blocks(dquot)) {
740#ifdef __DQUOT_PARANOIA
741 if (atomic_read(&dquot->dq_count) != 1)
742 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
743#endif
744 spin_lock(&dq_list_lock);
745 list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */
746 spin_unlock(&dq_list_lock);
747 return 1;
748 }
749 else
750 dqput(dquot); /* We have guaranteed we won't block */
751 }
752 return 0;
753}
754
755/* Free list of dquots - called from inode.c */
756/* dquots are removed from inodes, no new references can be got so we are the only ones holding reference */
757static void put_dquot_list(struct list_head *tofree_head)
758{
759 struct list_head *act_head;
760 struct dquot *dquot;
761
762 act_head = tofree_head->next;
763 /* So now we have dquots on the list... Just free them */
764 while (act_head != tofree_head) {
765 dquot = list_entry(act_head, struct dquot, dq_free);
766 act_head = act_head->next;
767 list_del_init(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */
768 dqput(dquot);
769 }
770}
771
Christoph Hellwigfb58b732007-02-12 00:51:57 -0800772static void remove_dquot_ref(struct super_block *sb, int type,
773 struct list_head *tofree_head)
774{
775 struct inode *inode;
776
777 spin_lock(&inode_lock);
778 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
779 if (!IS_NOQUOTA(inode))
780 remove_inode_dquot_ref(inode, type, tofree_head);
781 }
782 spin_unlock(&inode_lock);
783}
784
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785/* Gather all references from inodes and drop them */
786static void drop_dquot_ref(struct super_block *sb, int type)
787{
788 LIST_HEAD(tofree_head);
789
Christoph Hellwigfb58b732007-02-12 00:51:57 -0800790 if (sb->dq_op) {
791 down_write(&sb_dqopt(sb)->dqptr_sem);
792 remove_dquot_ref(sb, type, &tofree_head);
793 up_write(&sb_dqopt(sb)->dqptr_sem);
794 put_dquot_list(&tofree_head);
795 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796}
797
798static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number)
799{
800 dquot->dq_dqb.dqb_curinodes += number;
801}
802
803static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
804{
805 dquot->dq_dqb.dqb_curspace += number;
806}
807
808static inline void dquot_decr_inodes(struct dquot *dquot, unsigned long number)
809{
810 if (dquot->dq_dqb.dqb_curinodes > number)
811 dquot->dq_dqb.dqb_curinodes -= number;
812 else
813 dquot->dq_dqb.dqb_curinodes = 0;
814 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
815 dquot->dq_dqb.dqb_itime = (time_t) 0;
816 clear_bit(DQ_INODES_B, &dquot->dq_flags);
817}
818
819static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
820{
821 if (dquot->dq_dqb.dqb_curspace > number)
822 dquot->dq_dqb.dqb_curspace -= number;
823 else
824 dquot->dq_dqb.dqb_curspace = 0;
825 if (toqb(dquot->dq_dqb.dqb_curspace) <= dquot->dq_dqb.dqb_bsoftlimit)
826 dquot->dq_dqb.dqb_btime = (time_t) 0;
827 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
828}
829
Jan Kara8e893462007-10-16 23:29:31 -0700830#ifdef CONFIG_PRINT_QUOTA_WARNING
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831static int flag_print_warnings = 1;
832
833static inline int need_print_warning(struct dquot *dquot)
834{
835 if (!flag_print_warnings)
836 return 0;
837
838 switch (dquot->dq_type) {
839 case USRQUOTA:
840 return current->fsuid == dquot->dq_id;
841 case GRPQUOTA:
842 return in_group_p(dquot->dq_id);
843 }
844 return 0;
845}
846
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847/* Print warning to user which exceeded quota */
848static void print_warning(struct dquot *dquot, const char warntype)
849{
850 char *msg = NULL;
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800851 struct tty_struct *tty;
Jan Kara8e893462007-10-16 23:29:31 -0700852 int flag = (warntype == QUOTA_NL_BHARDWARN ||
853 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
854 ((warntype == QUOTA_NL_IHARDWARN ||
855 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856
857 if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags)))
858 return;
859
Jan Karab525a7e2006-09-29 02:00:26 -0700860 mutex_lock(&tty_mutex);
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800861 tty = get_current_tty();
862 if (!tty)
Jan Karab525a7e2006-09-29 02:00:26 -0700863 goto out_lock;
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800864 tty_write_message(tty, dquot->dq_sb->s_id);
Jan Kara8e893462007-10-16 23:29:31 -0700865 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800866 tty_write_message(tty, ": warning, ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 else
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800868 tty_write_message(tty, ": write failed, ");
869 tty_write_message(tty, quotatypes[dquot->dq_type]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 switch (warntype) {
Jan Kara8e893462007-10-16 23:29:31 -0700871 case QUOTA_NL_IHARDWARN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 msg = " file limit reached.\r\n";
873 break;
Jan Kara8e893462007-10-16 23:29:31 -0700874 case QUOTA_NL_ISOFTLONGWARN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 msg = " file quota exceeded too long.\r\n";
876 break;
Jan Kara8e893462007-10-16 23:29:31 -0700877 case QUOTA_NL_ISOFTWARN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 msg = " file quota exceeded.\r\n";
879 break;
Jan Kara8e893462007-10-16 23:29:31 -0700880 case QUOTA_NL_BHARDWARN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 msg = " block limit reached.\r\n";
882 break;
Jan Kara8e893462007-10-16 23:29:31 -0700883 case QUOTA_NL_BSOFTLONGWARN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 msg = " block quota exceeded too long.\r\n";
885 break;
Jan Kara8e893462007-10-16 23:29:31 -0700886 case QUOTA_NL_BSOFTWARN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 msg = " block quota exceeded.\r\n";
888 break;
889 }
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800890 tty_write_message(tty, msg);
Jan Karab525a7e2006-09-29 02:00:26 -0700891out_lock:
892 mutex_unlock(&tty_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893}
Jan Kara8e893462007-10-16 23:29:31 -0700894#endif
895
896#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
897
898/* Size of quota netlink message - actually an upperbound for buffer size */
899#define QUOTA_NL_MSG_SIZE 32
900
901/* Netlink family structure for quota */
902static struct genl_family quota_genl_family = {
903 .id = GENL_ID_GENERATE,
904 .hdrsize = 0,
905 .name = "VFS_DQUOT",
906 .version = 1,
907 .maxattr = QUOTA_NL_A_MAX,
908};
909
910/* Send warning to userspace about user which exceeded quota */
911static void send_warning(const struct dquot *dquot, const char warntype)
912{
913 static atomic_t seq;
914 struct sk_buff *skb;
915 void *msg_head;
916 int ret;
917
918 /* We have to allocate using GFP_NOFS as we are called from a
919 * filesystem performing write and thus further recursion into
920 * the fs to free some data could cause deadlocks. */
921 skb = genlmsg_new(QUOTA_NL_MSG_SIZE, GFP_NOFS);
922 if (!skb) {
923 printk(KERN_ERR
924 "VFS: Not enough memory to send quota warning.\n");
925 return;
926 }
927 msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
928 &quota_genl_family, 0, QUOTA_NL_C_WARNING);
929 if (!msg_head) {
930 printk(KERN_ERR
931 "VFS: Cannot store netlink header in quota warning.\n");
932 goto err_out;
933 }
934 ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type);
935 if (ret)
936 goto attr_err_out;
937 ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id);
938 if (ret)
939 goto attr_err_out;
940 ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
941 if (ret)
942 goto attr_err_out;
943 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR,
944 MAJOR(dquot->dq_sb->s_dev));
945 if (ret)
946 goto attr_err_out;
947 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR,
948 MINOR(dquot->dq_sb->s_dev));
949 if (ret)
950 goto attr_err_out;
951 ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current->user->uid);
952 if (ret)
953 goto attr_err_out;
954 genlmsg_end(skb, msg_head);
955
956 ret = genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
957 if (ret < 0 && ret != -ESRCH)
958 printk(KERN_ERR
959 "VFS: Failed to send notification message: %d\n", ret);
960 return;
961attr_err_out:
962 printk(KERN_ERR "VFS: Failed to compose quota message: %d\n", ret);
963err_out:
964 kfree_skb(skb);
965}
966#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967
968static inline void flush_warnings(struct dquot **dquots, char *warntype)
969{
970 int i;
971
972 for (i = 0; i < MAXQUOTAS; i++)
Jan Kara8e893462007-10-16 23:29:31 -0700973 if (dquots[i] != NODQUOT && warntype[i] != QUOTA_NL_NOWARN) {
974#ifdef CONFIG_PRINT_QUOTA_WARNING
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 print_warning(dquots[i], warntype[i]);
Jan Kara8e893462007-10-16 23:29:31 -0700976#endif
977#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
978 send_warning(dquots[i], warntype[i]);
979#endif
980 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981}
982
983static inline char ignore_hardlimit(struct dquot *dquot)
984{
985 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
986
987 return capable(CAP_SYS_RESOURCE) &&
988 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & V1_DQF_RSQUASH));
989}
990
991/* needs dq_data_lock */
992static int check_idq(struct dquot *dquot, ulong inodes, char *warntype)
993{
Jan Kara8e893462007-10-16 23:29:31 -0700994 *warntype = QUOTA_NL_NOWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
996 return QUOTA_OK;
997
998 if (dquot->dq_dqb.dqb_ihardlimit &&
999 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit &&
1000 !ignore_hardlimit(dquot)) {
Jan Kara8e893462007-10-16 23:29:31 -07001001 *warntype = QUOTA_NL_IHARDWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 return NO_QUOTA;
1003 }
1004
1005 if (dquot->dq_dqb.dqb_isoftlimit &&
1006 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
1007 dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime &&
1008 !ignore_hardlimit(dquot)) {
Jan Kara8e893462007-10-16 23:29:31 -07001009 *warntype = QUOTA_NL_ISOFTLONGWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 return NO_QUOTA;
1011 }
1012
1013 if (dquot->dq_dqb.dqb_isoftlimit &&
1014 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
1015 dquot->dq_dqb.dqb_itime == 0) {
Jan Kara8e893462007-10-16 23:29:31 -07001016 *warntype = QUOTA_NL_ISOFTWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1018 }
1019
1020 return QUOTA_OK;
1021}
1022
1023/* needs dq_data_lock */
1024static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1025{
Jan Kara8e893462007-10-16 23:29:31 -07001026 *warntype = QUOTA_NL_NOWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
1028 return QUOTA_OK;
1029
1030 if (dquot->dq_dqb.dqb_bhardlimit &&
1031 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bhardlimit &&
1032 !ignore_hardlimit(dquot)) {
1033 if (!prealloc)
Jan Kara8e893462007-10-16 23:29:31 -07001034 *warntype = QUOTA_NL_BHARDWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 return NO_QUOTA;
1036 }
1037
1038 if (dquot->dq_dqb.dqb_bsoftlimit &&
1039 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
1040 dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime &&
1041 !ignore_hardlimit(dquot)) {
1042 if (!prealloc)
Jan Kara8e893462007-10-16 23:29:31 -07001043 *warntype = QUOTA_NL_BSOFTLONGWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 return NO_QUOTA;
1045 }
1046
1047 if (dquot->dq_dqb.dqb_bsoftlimit &&
1048 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
1049 dquot->dq_dqb.dqb_btime == 0) {
1050 if (!prealloc) {
Jan Kara8e893462007-10-16 23:29:31 -07001051 *warntype = QUOTA_NL_BSOFTWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
1053 }
1054 else
1055 /*
1056 * We don't allow preallocation to exceed softlimit so exceeding will
1057 * be always printed
1058 */
1059 return NO_QUOTA;
1060 }
1061
1062 return QUOTA_OK;
1063}
1064
1065/*
1066 * Initialize quota pointers in inode
1067 * Transaction must be started at entry
1068 */
1069int dquot_initialize(struct inode *inode, int type)
1070{
1071 unsigned int id = 0;
1072 int cnt, ret = 0;
1073
Ingo Molnard3be9152006-03-23 03:00:29 -08001074 /* First test before acquiring mutex - solves deadlocks when we
1075 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 if (IS_NOQUOTA(inode))
1077 return 0;
1078 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1079 /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
1080 if (IS_NOQUOTA(inode))
1081 goto out_err;
1082 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1083 if (type != -1 && cnt != type)
1084 continue;
1085 if (inode->i_dquot[cnt] == NODQUOT) {
1086 switch (cnt) {
1087 case USRQUOTA:
1088 id = inode->i_uid;
1089 break;
1090 case GRPQUOTA:
1091 id = inode->i_gid;
1092 break;
1093 }
1094 inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt);
1095 }
1096 }
1097out_err:
1098 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1099 return ret;
1100}
1101
1102/*
1103 * Release all quotas referenced by inode
1104 * Transaction must be started at an entry
1105 */
1106int dquot_drop(struct inode *inode)
1107{
1108 int cnt;
1109
1110 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1111 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1112 if (inode->i_dquot[cnt] != NODQUOT) {
1113 dqput(inode->i_dquot[cnt]);
1114 inode->i_dquot[cnt] = NODQUOT;
1115 }
1116 }
1117 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1118 return 0;
1119}
1120
1121/*
1122 * Following four functions update i_blocks+i_bytes fields and
1123 * quota information (together with appropriate checks)
1124 * NOTE: We absolutely rely on the fact that caller dirties
1125 * the inode (usually macros in quotaops.h care about this) and
1126 * holds a handle for the current transaction so that dquot write and
1127 * inode write go into the same transaction.
1128 */
1129
1130/*
1131 * This operation can block, but only after everything is updated
1132 */
1133int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1134{
1135 int cnt, ret = NO_QUOTA;
1136 char warntype[MAXQUOTAS];
1137
Ingo Molnard3be9152006-03-23 03:00:29 -08001138 /* First test before acquiring mutex - solves deadlocks when we
1139 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 if (IS_NOQUOTA(inode)) {
1141out_add:
1142 inode_add_bytes(inode, number);
1143 return QUOTA_OK;
1144 }
1145 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
Jan Kara8e893462007-10-16 23:29:31 -07001146 warntype[cnt] = QUOTA_NL_NOWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147
1148 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1149 if (IS_NOQUOTA(inode)) { /* Now we can do reliable test... */
1150 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1151 goto out_add;
1152 }
1153 spin_lock(&dq_data_lock);
1154 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1155 if (inode->i_dquot[cnt] == NODQUOT)
1156 continue;
1157 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA)
1158 goto warn_put_all;
1159 }
1160 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1161 if (inode->i_dquot[cnt] == NODQUOT)
1162 continue;
1163 dquot_incr_space(inode->i_dquot[cnt], number);
1164 }
1165 inode_add_bytes(inode, number);
1166 ret = QUOTA_OK;
1167warn_put_all:
1168 spin_unlock(&dq_data_lock);
1169 if (ret == QUOTA_OK)
1170 /* Dirtify all the dquots - this can block when journalling */
1171 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1172 if (inode->i_dquot[cnt])
1173 mark_dquot_dirty(inode->i_dquot[cnt]);
1174 flush_warnings(inode->i_dquot, warntype);
1175 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1176 return ret;
1177}
1178
1179/*
1180 * This operation can block, but only after everything is updated
1181 */
1182int dquot_alloc_inode(const struct inode *inode, unsigned long number)
1183{
1184 int cnt, ret = NO_QUOTA;
1185 char warntype[MAXQUOTAS];
1186
Ingo Molnard3be9152006-03-23 03:00:29 -08001187 /* First test before acquiring mutex - solves deadlocks when we
1188 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 if (IS_NOQUOTA(inode))
1190 return QUOTA_OK;
1191 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
Jan Kara8e893462007-10-16 23:29:31 -07001192 warntype[cnt] = QUOTA_NL_NOWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1194 if (IS_NOQUOTA(inode)) {
1195 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1196 return QUOTA_OK;
1197 }
1198 spin_lock(&dq_data_lock);
1199 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1200 if (inode->i_dquot[cnt] == NODQUOT)
1201 continue;
1202 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA)
1203 goto warn_put_all;
1204 }
1205
1206 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1207 if (inode->i_dquot[cnt] == NODQUOT)
1208 continue;
1209 dquot_incr_inodes(inode->i_dquot[cnt], number);
1210 }
1211 ret = QUOTA_OK;
1212warn_put_all:
1213 spin_unlock(&dq_data_lock);
1214 if (ret == QUOTA_OK)
1215 /* Dirtify all the dquots - this can block when journalling */
1216 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1217 if (inode->i_dquot[cnt])
1218 mark_dquot_dirty(inode->i_dquot[cnt]);
1219 flush_warnings((struct dquot **)inode->i_dquot, warntype);
1220 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1221 return ret;
1222}
1223
1224/*
1225 * This operation can block, but only after everything is updated
1226 */
1227int dquot_free_space(struct inode *inode, qsize_t number)
1228{
1229 unsigned int cnt;
1230
Ingo Molnard3be9152006-03-23 03:00:29 -08001231 /* First test before acquiring mutex - solves deadlocks when we
1232 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 if (IS_NOQUOTA(inode)) {
1234out_sub:
1235 inode_sub_bytes(inode, number);
1236 return QUOTA_OK;
1237 }
1238 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1239 /* Now recheck reliably when holding dqptr_sem */
1240 if (IS_NOQUOTA(inode)) {
1241 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1242 goto out_sub;
1243 }
1244 spin_lock(&dq_data_lock);
1245 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1246 if (inode->i_dquot[cnt] == NODQUOT)
1247 continue;
1248 dquot_decr_space(inode->i_dquot[cnt], number);
1249 }
1250 inode_sub_bytes(inode, number);
1251 spin_unlock(&dq_data_lock);
1252 /* Dirtify all the dquots - this can block when journalling */
1253 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1254 if (inode->i_dquot[cnt])
1255 mark_dquot_dirty(inode->i_dquot[cnt]);
1256 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1257 return QUOTA_OK;
1258}
1259
1260/*
1261 * This operation can block, but only after everything is updated
1262 */
1263int dquot_free_inode(const struct inode *inode, unsigned long number)
1264{
1265 unsigned int cnt;
1266
Ingo Molnard3be9152006-03-23 03:00:29 -08001267 /* First test before acquiring mutex - solves deadlocks when we
1268 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 if (IS_NOQUOTA(inode))
1270 return QUOTA_OK;
1271 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1272 /* Now recheck reliably when holding dqptr_sem */
1273 if (IS_NOQUOTA(inode)) {
1274 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1275 return QUOTA_OK;
1276 }
1277 spin_lock(&dq_data_lock);
1278 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1279 if (inode->i_dquot[cnt] == NODQUOT)
1280 continue;
1281 dquot_decr_inodes(inode->i_dquot[cnt], number);
1282 }
1283 spin_unlock(&dq_data_lock);
1284 /* Dirtify all the dquots - this can block when journalling */
1285 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1286 if (inode->i_dquot[cnt])
1287 mark_dquot_dirty(inode->i_dquot[cnt]);
1288 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1289 return QUOTA_OK;
1290}
1291
1292/*
1293 * Transfer the number of inode and blocks from one diskquota to an other.
1294 *
1295 * This operation can block, but only after everything is updated
1296 * A transaction must be started when entering this function.
1297 */
1298int dquot_transfer(struct inode *inode, struct iattr *iattr)
1299{
1300 qsize_t space;
1301 struct dquot *transfer_from[MAXQUOTAS];
1302 struct dquot *transfer_to[MAXQUOTAS];
1303 int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid,
1304 chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid;
1305 char warntype[MAXQUOTAS];
1306
Ingo Molnard3be9152006-03-23 03:00:29 -08001307 /* First test before acquiring mutex - solves deadlocks when we
1308 * re-enter the quota code and are already holding the mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309 if (IS_NOQUOTA(inode))
1310 return QUOTA_OK;
1311 /* Clear the arrays */
1312 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1313 transfer_to[cnt] = transfer_from[cnt] = NODQUOT;
Jan Kara8e893462007-10-16 23:29:31 -07001314 warntype[cnt] = QUOTA_NL_NOWARN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 }
1316 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1317 /* Now recheck reliably when holding dqptr_sem */
1318 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */
1319 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1320 return QUOTA_OK;
1321 }
1322 /* First build the transfer_to list - here we can block on
1323 * reading/instantiating of dquots. We know that the transaction for
1324 * us was already started so we don't violate lock ranking here */
1325 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1326 switch (cnt) {
1327 case USRQUOTA:
1328 if (!chuid)
1329 continue;
1330 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt);
1331 break;
1332 case GRPQUOTA:
1333 if (!chgid)
1334 continue;
1335 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt);
1336 break;
1337 }
1338 }
1339 spin_lock(&dq_data_lock);
1340 space = inode_get_bytes(inode);
1341 /* Build the transfer_from list and check the limits */
1342 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1343 if (transfer_to[cnt] == NODQUOT)
1344 continue;
1345 transfer_from[cnt] = inode->i_dquot[cnt];
1346 if (check_idq(transfer_to[cnt], 1, warntype+cnt) == NO_QUOTA ||
1347 check_bdq(transfer_to[cnt], space, 0, warntype+cnt) == NO_QUOTA)
1348 goto warn_put_all;
1349 }
1350
1351 /*
1352 * Finally perform the needed transfer from transfer_from to transfer_to
1353 */
1354 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1355 /*
1356 * Skip changes for same uid or gid or for turned off quota-type.
1357 */
1358 if (transfer_to[cnt] == NODQUOT)
1359 continue;
1360
1361 /* Due to IO error we might not have transfer_from[] structure */
1362 if (transfer_from[cnt]) {
1363 dquot_decr_inodes(transfer_from[cnt], 1);
1364 dquot_decr_space(transfer_from[cnt], space);
1365 }
1366
1367 dquot_incr_inodes(transfer_to[cnt], 1);
1368 dquot_incr_space(transfer_to[cnt], space);
1369
1370 inode->i_dquot[cnt] = transfer_to[cnt];
1371 }
1372 ret = QUOTA_OK;
1373warn_put_all:
1374 spin_unlock(&dq_data_lock);
1375 /* Dirtify all the dquots - this can block when journalling */
1376 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1377 if (transfer_from[cnt])
1378 mark_dquot_dirty(transfer_from[cnt]);
1379 if (transfer_to[cnt])
1380 mark_dquot_dirty(transfer_to[cnt]);
1381 }
1382 flush_warnings(transfer_to, warntype);
1383
1384 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1385 if (ret == QUOTA_OK && transfer_from[cnt] != NODQUOT)
1386 dqput(transfer_from[cnt]);
1387 if (ret == NO_QUOTA && transfer_to[cnt] != NODQUOT)
1388 dqput(transfer_to[cnt]);
1389 }
1390 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1391 return ret;
1392}
1393
1394/*
1395 * Write info of quota file to disk
1396 */
1397int dquot_commit_info(struct super_block *sb, int type)
1398{
1399 int ret;
1400 struct quota_info *dqopt = sb_dqopt(sb);
1401
Ingo Molnard3be9152006-03-23 03:00:29 -08001402 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403 ret = dqopt->ops[type]->write_file_info(sb, type);
Ingo Molnard3be9152006-03-23 03:00:29 -08001404 mutex_unlock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405 return ret;
1406}
1407
1408/*
1409 * Definitions of diskquota operations.
1410 */
1411struct dquot_operations dquot_operations = {
1412 .initialize = dquot_initialize,
1413 .drop = dquot_drop,
1414 .alloc_space = dquot_alloc_space,
1415 .alloc_inode = dquot_alloc_inode,
1416 .free_space = dquot_free_space,
1417 .free_inode = dquot_free_inode,
1418 .transfer = dquot_transfer,
1419 .write_dquot = dquot_commit,
1420 .acquire_dquot = dquot_acquire,
1421 .release_dquot = dquot_release,
1422 .mark_dirty = dquot_mark_dquot_dirty,
1423 .write_info = dquot_commit_info
1424};
1425
1426static inline void set_enable_flags(struct quota_info *dqopt, int type)
1427{
1428 switch (type) {
1429 case USRQUOTA:
1430 dqopt->flags |= DQUOT_USR_ENABLED;
1431 break;
1432 case GRPQUOTA:
1433 dqopt->flags |= DQUOT_GRP_ENABLED;
1434 break;
1435 }
1436}
1437
1438static inline void reset_enable_flags(struct quota_info *dqopt, int type)
1439{
1440 switch (type) {
1441 case USRQUOTA:
1442 dqopt->flags &= ~DQUOT_USR_ENABLED;
1443 break;
1444 case GRPQUOTA:
1445 dqopt->flags &= ~DQUOT_GRP_ENABLED;
1446 break;
1447 }
1448}
1449
1450/*
1451 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1452 */
1453int vfs_quota_off(struct super_block *sb, int type)
1454{
1455 int cnt;
1456 struct quota_info *dqopt = sb_dqopt(sb);
1457 struct inode *toputinode[MAXQUOTAS];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001458
1459 /* We need to serialize quota_off() for device */
Ingo Molnard3be9152006-03-23 03:00:29 -08001460 mutex_lock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1462 toputinode[cnt] = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463 if (type != -1 && cnt != type)
1464 continue;
1465 if (!sb_has_quota_enabled(sb, cnt))
1466 continue;
1467 reset_enable_flags(dqopt, cnt);
1468
1469 /* Note: these are blocking operations */
1470 drop_dquot_ref(sb, cnt);
1471 invalidate_dquots(sb, cnt);
1472 /*
1473 * Now all dquots should be invalidated, all writes done so we should be only
1474 * users of the info. No locks needed.
1475 */
1476 if (info_dirty(&dqopt->info[cnt]))
1477 sb->dq_op->write_info(sb, cnt);
1478 if (dqopt->ops[cnt]->free_file_info)
1479 dqopt->ops[cnt]->free_file_info(sb, cnt);
1480 put_quota_format(dqopt->info[cnt].dqi_format);
1481
1482 toputinode[cnt] = dqopt->files[cnt];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001483 dqopt->files[cnt] = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484 dqopt->info[cnt].dqi_flags = 0;
1485 dqopt->info[cnt].dqi_igrace = 0;
1486 dqopt->info[cnt].dqi_bgrace = 0;
1487 dqopt->ops[cnt] = NULL;
1488 }
Ingo Molnard3be9152006-03-23 03:00:29 -08001489 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 /* Sync the superblock so that buffers with quota data are written to
Al Viro7b7b1ac2005-11-07 17:13:39 -05001491 * disk (and so userspace sees correct data afterwards). */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492 if (sb->s_op->sync_fs)
1493 sb->s_op->sync_fs(sb, 1);
1494 sync_blockdev(sb->s_bdev);
1495 /* Now the quota files are just ordinary files and we can set the
1496 * inode flags back. Moreover we discard the pagecache so that
1497 * userspace sees the writes we did bypassing the pagecache. We
1498 * must also discard the blockdev buffers so that we see the
1499 * changes done by userspace on the next quotaon() */
1500 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1501 if (toputinode[cnt]) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001502 mutex_lock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503 /* If quota was reenabled in the meantime, we have
1504 * nothing to do */
1505 if (!sb_has_quota_enabled(sb, cnt)) {
Jan Kara79254092007-05-16 22:11:19 -07001506 mutex_lock_nested(&toputinode[cnt]->i_mutex, I_MUTEX_QUOTA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1508 S_NOATIME | S_NOQUOTA);
1509 truncate_inode_pages(&toputinode[cnt]->i_data, 0);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001510 mutex_unlock(&toputinode[cnt]->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 mark_inode_dirty(toputinode[cnt]);
1512 iput(toputinode[cnt]);
1513 }
Ingo Molnard3be9152006-03-23 03:00:29 -08001514 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515 }
1516 if (sb->s_bdev)
Peter Zijlstraf98393a2007-05-06 14:49:54 -07001517 invalidate_bdev(sb->s_bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001518 return 0;
1519}
1520
1521/*
1522 * Turn quotas on on a device
1523 */
1524
1525/* Helper function when we already have the inode */
1526static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
1527{
1528 struct quota_format_type *fmt = find_quota_format(format_id);
1529 struct super_block *sb = inode->i_sb;
1530 struct quota_info *dqopt = sb_dqopt(sb);
1531 int error;
1532 int oldflags = -1;
1533
1534 if (!fmt)
1535 return -ESRCH;
1536 if (!S_ISREG(inode->i_mode)) {
1537 error = -EACCES;
1538 goto out_fmt;
1539 }
1540 if (IS_RDONLY(inode)) {
1541 error = -EROFS;
1542 goto out_fmt;
1543 }
1544 if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
1545 error = -EINVAL;
1546 goto out_fmt;
1547 }
1548
1549 /* As we bypass the pagecache we must now flush the inode so that
1550 * we see all the changes from userspace... */
1551 write_inode_now(inode, 1);
1552 /* And now flush the block cache so that kernel sees the changes */
Peter Zijlstraf98393a2007-05-06 14:49:54 -07001553 invalidate_bdev(sb->s_bdev);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001554 mutex_lock(&inode->i_mutex);
Ingo Molnard3be9152006-03-23 03:00:29 -08001555 mutex_lock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001556 if (sb_has_quota_enabled(sb, type)) {
1557 error = -EBUSY;
1558 goto out_lock;
1559 }
1560 /* We don't want quota and atime on quota files (deadlocks possible)
1561 * Also nobody should write to the file - we use special IO operations
1562 * which ignore the immutable bit. */
1563 down_write(&dqopt->dqptr_sem);
1564 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA);
1565 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
1566 up_write(&dqopt->dqptr_sem);
Jan Kara31e7ad62005-04-16 15:25:46 -07001567 sb->dq_op->drop(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001568
1569 error = -EIO;
1570 dqopt->files[type] = igrab(inode);
1571 if (!dqopt->files[type])
1572 goto out_lock;
1573 error = -EINVAL;
1574 if (!fmt->qf_ops->check_quota_file(sb, type))
1575 goto out_file_init;
1576
1577 dqopt->ops[type] = fmt->qf_ops;
1578 dqopt->info[type].dqi_format = fmt;
1579 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
Ingo Molnard3be9152006-03-23 03:00:29 -08001580 mutex_lock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581 if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001582 mutex_unlock(&dqopt->dqio_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583 goto out_file_init;
1584 }
Ingo Molnard3be9152006-03-23 03:00:29 -08001585 mutex_unlock(&dqopt->dqio_mutex);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001586 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001587 set_enable_flags(dqopt, type);
1588
1589 add_dquot_ref(sb, type);
Ingo Molnard3be9152006-03-23 03:00:29 -08001590 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001591
1592 return 0;
1593
1594out_file_init:
1595 dqopt->files[type] = NULL;
1596 iput(inode);
1597out_lock:
Ingo Molnard3be9152006-03-23 03:00:29 -08001598 mutex_unlock(&dqopt->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599 if (oldflags != -1) {
1600 down_write(&dqopt->dqptr_sem);
1601 /* Set the flags back (in the case of accidental quotaon()
1602 * on a wrong file we don't want to mess up the flags) */
1603 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
1604 inode->i_flags |= oldflags;
1605 up_write(&dqopt->dqptr_sem);
1606 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001607 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001608out_fmt:
1609 put_quota_format(fmt);
1610
1611 return error;
1612}
1613
1614/* Actual function called from quotactl() */
1615int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path)
1616{
1617 struct nameidata nd;
1618 int error;
1619
1620 error = path_lookup(path, LOOKUP_FOLLOW, &nd);
1621 if (error < 0)
1622 return error;
1623 error = security_quota_on(nd.dentry);
1624 if (error)
1625 goto out_path;
1626 /* Quota file not on the same filesystem? */
1627 if (nd.mnt->mnt_sb != sb)
1628 error = -EXDEV;
Al Viro7b7b1ac2005-11-07 17:13:39 -05001629 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001630 error = vfs_quota_on_inode(nd.dentry->d_inode, type, format_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631out_path:
1632 path_release(&nd);
1633 return error;
1634}
1635
1636/*
1637 * This function is used when filesystem needs to initialize quotas
1638 * during mount time.
1639 */
Christoph Hellwig84de8562005-06-23 00:09:16 -07001640int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
1641 int format_id, int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001642{
Christoph Hellwig84de8562005-06-23 00:09:16 -07001643 struct dentry *dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001644 int error;
1645
Christoph Hellwig2fa389c2005-06-23 00:09:16 -07001646 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
Christoph Hellwig84de8562005-06-23 00:09:16 -07001647 if (IS_ERR(dentry))
1648 return PTR_ERR(dentry);
1649
Jan Kara154f4842005-11-28 13:44:14 -08001650 if (!dentry->d_inode) {
1651 error = -ENOENT;
1652 goto out;
1653 }
1654
Linus Torvalds1da177e2005-04-16 15:20:36 -07001655 error = security_quota_on(dentry);
Christoph Hellwig84de8562005-06-23 00:09:16 -07001656 if (!error)
1657 error = vfs_quota_on_inode(dentry->d_inode, type, format_id);
1658
Jan Kara154f4842005-11-28 13:44:14 -08001659out:
Christoph Hellwig84de8562005-06-23 00:09:16 -07001660 dput(dentry);
1661 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001662}
1663
1664/* Generic routine for getting common part of quota structure */
1665static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
1666{
1667 struct mem_dqblk *dm = &dquot->dq_dqb;
1668
1669 spin_lock(&dq_data_lock);
1670 di->dqb_bhardlimit = dm->dqb_bhardlimit;
1671 di->dqb_bsoftlimit = dm->dqb_bsoftlimit;
1672 di->dqb_curspace = dm->dqb_curspace;
1673 di->dqb_ihardlimit = dm->dqb_ihardlimit;
1674 di->dqb_isoftlimit = dm->dqb_isoftlimit;
1675 di->dqb_curinodes = dm->dqb_curinodes;
1676 di->dqb_btime = dm->dqb_btime;
1677 di->dqb_itime = dm->dqb_itime;
1678 di->dqb_valid = QIF_ALL;
1679 spin_unlock(&dq_data_lock);
1680}
1681
1682int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
1683{
1684 struct dquot *dquot;
1685
Ingo Molnard3be9152006-03-23 03:00:29 -08001686 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001687 if (!(dquot = dqget(sb, id, type))) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001688 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689 return -ESRCH;
1690 }
1691 do_get_dqblk(dquot, di);
1692 dqput(dquot);
Ingo Molnard3be9152006-03-23 03:00:29 -08001693 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 return 0;
1695}
1696
1697/* Generic routine for setting common part of quota structure */
1698static void do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
1699{
1700 struct mem_dqblk *dm = &dquot->dq_dqb;
1701 int check_blim = 0, check_ilim = 0;
1702
1703 spin_lock(&dq_data_lock);
1704 if (di->dqb_valid & QIF_SPACE) {
1705 dm->dqb_curspace = di->dqb_curspace;
1706 check_blim = 1;
1707 }
1708 if (di->dqb_valid & QIF_BLIMITS) {
1709 dm->dqb_bsoftlimit = di->dqb_bsoftlimit;
1710 dm->dqb_bhardlimit = di->dqb_bhardlimit;
1711 check_blim = 1;
1712 }
1713 if (di->dqb_valid & QIF_INODES) {
1714 dm->dqb_curinodes = di->dqb_curinodes;
1715 check_ilim = 1;
1716 }
1717 if (di->dqb_valid & QIF_ILIMITS) {
1718 dm->dqb_isoftlimit = di->dqb_isoftlimit;
1719 dm->dqb_ihardlimit = di->dqb_ihardlimit;
1720 check_ilim = 1;
1721 }
1722 if (di->dqb_valid & QIF_BTIME)
1723 dm->dqb_btime = di->dqb_btime;
1724 if (di->dqb_valid & QIF_ITIME)
1725 dm->dqb_itime = di->dqb_itime;
1726
1727 if (check_blim) {
1728 if (!dm->dqb_bsoftlimit || toqb(dm->dqb_curspace) < dm->dqb_bsoftlimit) {
1729 dm->dqb_btime = 0;
1730 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1731 }
1732 else if (!(di->dqb_valid & QIF_BTIME)) /* Set grace only if user hasn't provided his own... */
1733 dm->dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
1734 }
1735 if (check_ilim) {
1736 if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) {
1737 dm->dqb_itime = 0;
1738 clear_bit(DQ_INODES_B, &dquot->dq_flags);
1739 }
1740 else if (!(di->dqb_valid & QIF_ITIME)) /* Set grace only if user hasn't provided his own... */
1741 dm->dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1742 }
1743 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit)
1744 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
1745 else
1746 set_bit(DQ_FAKE_B, &dquot->dq_flags);
1747 spin_unlock(&dq_data_lock);
1748 mark_dquot_dirty(dquot);
1749}
1750
1751int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
1752{
1753 struct dquot *dquot;
1754
Ingo Molnard3be9152006-03-23 03:00:29 -08001755 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001756 if (!(dquot = dqget(sb, id, type))) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001757 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001758 return -ESRCH;
1759 }
1760 do_set_dqblk(dquot, di);
1761 dqput(dquot);
Ingo Molnard3be9152006-03-23 03:00:29 -08001762 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001763 return 0;
1764}
1765
1766/* Generic routine for getting common part of quota file information */
1767int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
1768{
1769 struct mem_dqinfo *mi;
1770
Ingo Molnard3be9152006-03-23 03:00:29 -08001771 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001772 if (!sb_has_quota_enabled(sb, type)) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001773 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001774 return -ESRCH;
1775 }
1776 mi = sb_dqopt(sb)->info + type;
1777 spin_lock(&dq_data_lock);
1778 ii->dqi_bgrace = mi->dqi_bgrace;
1779 ii->dqi_igrace = mi->dqi_igrace;
1780 ii->dqi_flags = mi->dqi_flags & DQF_MASK;
1781 ii->dqi_valid = IIF_ALL;
1782 spin_unlock(&dq_data_lock);
Ingo Molnard3be9152006-03-23 03:00:29 -08001783 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784 return 0;
1785}
1786
1787/* Generic routine for setting common part of quota file information */
1788int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
1789{
1790 struct mem_dqinfo *mi;
1791
Ingo Molnard3be9152006-03-23 03:00:29 -08001792 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001793 if (!sb_has_quota_enabled(sb, type)) {
Ingo Molnard3be9152006-03-23 03:00:29 -08001794 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 return -ESRCH;
1796 }
1797 mi = sb_dqopt(sb)->info + type;
1798 spin_lock(&dq_data_lock);
1799 if (ii->dqi_valid & IIF_BGRACE)
1800 mi->dqi_bgrace = ii->dqi_bgrace;
1801 if (ii->dqi_valid & IIF_IGRACE)
1802 mi->dqi_igrace = ii->dqi_igrace;
1803 if (ii->dqi_valid & IIF_FLAGS)
1804 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | (ii->dqi_flags & DQF_MASK);
1805 spin_unlock(&dq_data_lock);
1806 mark_info_dirty(sb, type);
1807 /* Force write to disk */
1808 sb->dq_op->write_info(sb, type);
Ingo Molnard3be9152006-03-23 03:00:29 -08001809 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001810 return 0;
1811}
1812
1813struct quotactl_ops vfs_quotactl_ops = {
1814 .quota_on = vfs_quota_on,
1815 .quota_off = vfs_quota_off,
1816 .quota_sync = vfs_quota_sync,
1817 .get_info = vfs_get_dqinfo,
1818 .set_info = vfs_set_dqinfo,
1819 .get_dqblk = vfs_get_dqblk,
1820 .set_dqblk = vfs_set_dqblk
1821};
1822
1823static ctl_table fs_dqstats_table[] = {
1824 {
1825 .ctl_name = FS_DQ_LOOKUPS,
1826 .procname = "lookups",
1827 .data = &dqstats.lookups,
1828 .maxlen = sizeof(int),
1829 .mode = 0444,
1830 .proc_handler = &proc_dointvec,
1831 },
1832 {
1833 .ctl_name = FS_DQ_DROPS,
1834 .procname = "drops",
1835 .data = &dqstats.drops,
1836 .maxlen = sizeof(int),
1837 .mode = 0444,
1838 .proc_handler = &proc_dointvec,
1839 },
1840 {
1841 .ctl_name = FS_DQ_READS,
1842 .procname = "reads",
1843 .data = &dqstats.reads,
1844 .maxlen = sizeof(int),
1845 .mode = 0444,
1846 .proc_handler = &proc_dointvec,
1847 },
1848 {
1849 .ctl_name = FS_DQ_WRITES,
1850 .procname = "writes",
1851 .data = &dqstats.writes,
1852 .maxlen = sizeof(int),
1853 .mode = 0444,
1854 .proc_handler = &proc_dointvec,
1855 },
1856 {
1857 .ctl_name = FS_DQ_CACHE_HITS,
1858 .procname = "cache_hits",
1859 .data = &dqstats.cache_hits,
1860 .maxlen = sizeof(int),
1861 .mode = 0444,
1862 .proc_handler = &proc_dointvec,
1863 },
1864 {
1865 .ctl_name = FS_DQ_ALLOCATED,
1866 .procname = "allocated_dquots",
1867 .data = &dqstats.allocated_dquots,
1868 .maxlen = sizeof(int),
1869 .mode = 0444,
1870 .proc_handler = &proc_dointvec,
1871 },
1872 {
1873 .ctl_name = FS_DQ_FREE,
1874 .procname = "free_dquots",
1875 .data = &dqstats.free_dquots,
1876 .maxlen = sizeof(int),
1877 .mode = 0444,
1878 .proc_handler = &proc_dointvec,
1879 },
1880 {
1881 .ctl_name = FS_DQ_SYNCS,
1882 .procname = "syncs",
1883 .data = &dqstats.syncs,
1884 .maxlen = sizeof(int),
1885 .mode = 0444,
1886 .proc_handler = &proc_dointvec,
1887 },
Jan Kara8e893462007-10-16 23:29:31 -07001888#ifdef CONFIG_PRINT_QUOTA_WARNING
Linus Torvalds1da177e2005-04-16 15:20:36 -07001889 {
1890 .ctl_name = FS_DQ_WARNINGS,
1891 .procname = "warnings",
1892 .data = &flag_print_warnings,
1893 .maxlen = sizeof(int),
1894 .mode = 0644,
1895 .proc_handler = &proc_dointvec,
1896 },
Jan Kara8e893462007-10-16 23:29:31 -07001897#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001898 { .ctl_name = 0 },
1899};
1900
1901static ctl_table fs_table[] = {
1902 {
1903 .ctl_name = FS_DQSTATS,
1904 .procname = "quota",
1905 .mode = 0555,
1906 .child = fs_dqstats_table,
1907 },
1908 { .ctl_name = 0 },
1909};
1910
1911static ctl_table sys_table[] = {
1912 {
1913 .ctl_name = CTL_FS,
1914 .procname = "fs",
1915 .mode = 0555,
1916 .child = fs_table,
1917 },
1918 { .ctl_name = 0 },
1919};
1920
1921static int __init dquot_init(void)
1922{
1923 int i;
1924 unsigned long nr_hash, order;
1925
1926 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
1927
Eric W. Biederman0b4d4142007-02-14 00:34:09 -08001928 register_sysctl_table(sys_table);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001929
Paul Mundt20c2df82007-07-20 10:11:58 +09001930 dquot_cachep = kmem_cache_create("dquot",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001931 sizeof(struct dquot), sizeof(unsigned long) * 4,
Paul Jacksonfffb60f2006-03-24 03:16:06 -08001932 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1933 SLAB_MEM_SPREAD|SLAB_PANIC),
Paul Mundt20c2df82007-07-20 10:11:58 +09001934 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001935
1936 order = 0;
1937 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
1938 if (!dquot_hash)
1939 panic("Cannot create dquot hash table");
1940
1941 /* Find power-of-two hlist_heads which can fit into allocation */
1942 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
1943 dq_hash_bits = 0;
1944 do {
1945 dq_hash_bits++;
1946 } while (nr_hash >> dq_hash_bits);
1947 dq_hash_bits--;
1948
1949 nr_hash = 1UL << dq_hash_bits;
1950 dq_hash_mask = nr_hash - 1;
1951 for (i = 0; i < nr_hash; i++)
1952 INIT_HLIST_HEAD(dquot_hash + i);
1953
1954 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
1955 nr_hash, order, (PAGE_SIZE << order));
1956
Rusty Russell8e1f9362007-07-17 04:03:17 -07001957 register_shrinker(&dqcache_shrinker);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001958
Jan Kara8e893462007-10-16 23:29:31 -07001959#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1960 if (genl_register_family(&quota_genl_family) != 0)
1961 printk(KERN_ERR "VFS: Failed to create quota netlink interface.\n");
1962#endif
1963
Linus Torvalds1da177e2005-04-16 15:20:36 -07001964 return 0;
1965}
1966module_init(dquot_init);
1967
1968EXPORT_SYMBOL(register_quota_format);
1969EXPORT_SYMBOL(unregister_quota_format);
1970EXPORT_SYMBOL(dqstats);
1971EXPORT_SYMBOL(dq_data_lock);
1972EXPORT_SYMBOL(vfs_quota_on);
1973EXPORT_SYMBOL(vfs_quota_on_mount);
1974EXPORT_SYMBOL(vfs_quota_off);
1975EXPORT_SYMBOL(vfs_quota_sync);
1976EXPORT_SYMBOL(vfs_get_dqinfo);
1977EXPORT_SYMBOL(vfs_set_dqinfo);
1978EXPORT_SYMBOL(vfs_get_dqblk);
1979EXPORT_SYMBOL(vfs_set_dqblk);
1980EXPORT_SYMBOL(dquot_commit);
1981EXPORT_SYMBOL(dquot_commit_info);
1982EXPORT_SYMBOL(dquot_acquire);
1983EXPORT_SYMBOL(dquot_release);
1984EXPORT_SYMBOL(dquot_mark_dquot_dirty);
1985EXPORT_SYMBOL(dquot_initialize);
1986EXPORT_SYMBOL(dquot_drop);
1987EXPORT_SYMBOL(dquot_alloc_space);
1988EXPORT_SYMBOL(dquot_alloc_inode);
1989EXPORT_SYMBOL(dquot_free_space);
1990EXPORT_SYMBOL(dquot_free_inode);
1991EXPORT_SYMBOL(dquot_transfer);