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quota: Fix dquot_transfer for filesystems different from ext4
[net-next-2.6.git] / fs / quota / dquot.c
CommitLineData
1da177e4
LT		 1/*
2 * Implementation of the diskquota system for the LINUX operating system. QUOTA
3 * is implemented using the BSD system call interface as the means of
4 * communication with the user level. This file contains the generic routines
5 * called by the different filesystems on allocation of an inode or block.
6 * These routines take care of the administration needed to have a consistent
7 * diskquota tracking system. The ideas of both user and group quotas are based
8 * on the Melbourne quota system as used on BSD derived systems. The internal
9 * implementation is based on one of the several variants of the LINUX
10 * inode-subsystem with added complexity of the diskquota system.
11 *
1da177e4
LT		 12 * Author: Marco van Wieringen <mvw@planets.elm.net>
13 *
14 * Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
15 *
16 * Revised list management to avoid races
17 * -- Bill Hawes, <whawes@star.net>, 9/98
18 *
19 * Fixed races in dquot_transfer(), dqget() and dquot_alloc_...().
20 * As the consequence the locking was moved from dquot_decr_...(),
21 * dquot_incr_...() to calling functions.
22 * invalidate_dquots() now writes modified dquots.
23 * Serialized quota_off() and quota_on() for mount point.
24 * Fixed a few bugs in grow_dquots().
25 * Fixed deadlock in write_dquot() - we no longer account quotas on
26 * quota files
27 * remove_dquot_ref() moved to inode.c - it now traverses through inodes
28 * add_dquot_ref() restarts after blocking
29 * Added check for bogus uid and fixed check for group in quotactl.
30 * Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99
31 *
32 * Used struct list_head instead of own list struct
33 * Invalidation of referenced dquots is no longer possible
34 * Improved free_dquots list management
35 * Quota and i_blocks are now updated in one place to avoid races
36 * Warnings are now delayed so we won't block in critical section
37 * Write updated not to require dquot lock
38 * Jan Kara, <jack@suse.cz>, 9/2000
39 *
40 * Added dynamic quota structure allocation
41 * Jan Kara <jack@suse.cz> 12/2000
42 *
43 * Rewritten quota interface. Implemented new quota format and
44 * formats registering.
45 * Jan Kara, <jack@suse.cz>, 2001,2002
46 *
47 * New SMP locking.
48 * Jan Kara, <jack@suse.cz>, 10/2002
49 *
50 * Added journalled quota support, fix lock inversion problems
51 * Jan Kara, <jack@suse.cz>, 2003,2004
52 *
53 * (C) Copyright 1994 - 1997 Marco van Wieringen
54 */
55
56#include <linux/errno.h>
57#include <linux/kernel.h>
58#include <linux/fs.h>
59#include <linux/mount.h>
60#include <linux/mm.h>
61#include <linux/time.h>
62#include <linux/types.h>
63#include <linux/string.h>
64#include <linux/fcntl.h>
65#include <linux/stat.h>
66#include <linux/tty.h>
67#include <linux/file.h>
68#include <linux/slab.h>
69#include <linux/sysctl.h>
1da177e4
LT		 70#include <linux/init.h>
71#include <linux/module.h>
72#include <linux/proc_fs.h>
73#include <linux/security.h>
74#include <linux/kmod.h>
75#include <linux/namei.h>
76#include <linux/buffer_head.h>
16f7e0fe 77#include <linux/capability.h>
be586bab 78#include <linux/quotaops.h>
fb58b731 79#include <linux/writeback.h> /* for inode_lock, oddly enough.. */
1da177e4
LT		 80
81#include <asm/uaccess.h>
82
83#define __DQUOT_PARANOIA
84
85/*
cc33412f
JK		 86 * There are three quota SMP locks. dq_list_lock protects all lists with quotas
87 * and quota formats, dqstats structure containing statistics about the lists
88 * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
89 * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
1da177e4 90 * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
cc33412f
JK		 91 * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
92 * modifications of quota state (on quotaon and quotaoff) and readers who care
93 * about latest values take it as well.
1da177e4 94 *
cc33412f
JK		 95 * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
96 * dq_list_lock > dq_state_lock
1da177e4
LT		 97 *
98 * Note that some things (eg. sb pointer, type, id) doesn't change during
99 * the life of the dquot structure and so needn't to be protected by a lock
100 *
101 * Any operation working on dquots via inode pointers must hold dqptr_sem. If
102 * operation is just reading pointers from inode (or not using them at all) the
103 * read lock is enough. If pointers are altered function must hold write lock
104 * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
cc33412f 105 * for altering the flag i_mutex is also needed).
1da177e4 106 *
d3be915f 107 * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
1da177e4
LT		 108 * from inodes (dquot_alloc_space() and such don't check the dq_lock).
109 * Currently dquot is locked only when it is being read to memory (or space for
110 * it is being allocated) on the first dqget() and when it is being released on
111 * the last dqput(). The allocation and release oparations are serialized by
112 * the dq_lock and by checking the use count in dquot_release(). Write
113 * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
114 * spinlock to internal buffers before writing.
115 *
116 * Lock ordering (including related VFS locks) is the following:
d3be915f
IM		 117 * i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
118 * dqio_mutex
cc33412f
JK		 119 * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem >
120 * dqptr_sem. But filesystem has to count with the fact that functions such as
121 * dquot_alloc_space() acquire dqptr_sem and they usually have to be called
122 * from inside a transaction to keep filesystem consistency after a crash. Also
123 * filesystems usually want to do some IO on dquot from ->mark_dirty which is
124 * called with dqptr_sem held.
d3be915f 125 * i_mutex on quota files is special (it's below dqio_mutex)
1da177e4
LT		 126 */
127
c516610c
JK		 128static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
129static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
130__cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
08d0350c 131EXPORT_SYMBOL(dq_data_lock);
1da177e4
LT		 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 */
e18b890b 138static struct kmem_cache *dquot_cachep;
1da177e4
LT		 139
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}
08d0350c 148EXPORT_SYMBOL(register_quota_format);
1da177e4
LT		 149
150void unregister_quota_format(struct quota_format_type *fmt)
151{
152 struct quota_format_type **actqf;
153
154 spin_lock(&dq_list_lock);
268157ba
JK		 155 for (actqf = &quota_formats; *actqf && *actqf != fmt;
156 actqf = &(*actqf)->qf_next)
157 ;
1da177e4
LT		 158 if (*actqf)
159 *actqf = (*actqf)->qf_next;
160 spin_unlock(&dq_list_lock);
161}
08d0350c 162EXPORT_SYMBOL(unregister_quota_format);
1da177e4
LT		 163
164static struct quota_format_type *find_quota_format(int id)
165{
166 struct quota_format_type *actqf;
167
168 spin_lock(&dq_list_lock);
268157ba
JK		 169 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
170 actqf = actqf->qf_next)
171 ;
1da177e4
LT		 172 if (!actqf || !try_module_get(actqf->qf_owner)) {
173 int qm;
174
175 spin_unlock(&dq_list_lock);
176
268157ba
JK		 177 for (qm = 0; module_names[qm].qm_fmt_id &&
178 module_names[qm].qm_fmt_id != id; qm++)
179 ;
180 if (!module_names[qm].qm_fmt_id ||
181 request_module(module_names[qm].qm_mod_name))
1da177e4
LT		 182 return NULL;
183
184 spin_lock(&dq_list_lock);
268157ba
JK		 185 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
186 actqf = actqf->qf_next)
187 ;
1da177e4
LT		 188 if (actqf && !try_module_get(actqf->qf_owner))
189 actqf = NULL;
190 }
191 spin_unlock(&dq_list_lock);
192 return actqf;
193}
194
195static void put_quota_format(struct quota_format_type *fmt)
196{
197 module_put(fmt->qf_owner);
198}
199
200/*
201 * Dquot List Management:
202 * The quota code uses three lists for dquot management: the inuse_list,
203 * free_dquots, and dquot_hash[] array. A single dquot structure may be
204 * on all three lists, depending on its current state.
205 *
206 * All dquots are placed to the end of inuse_list when first created, and this
207 * list is used for invalidate operation, which must look at every dquot.
208 *
209 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
210 * and this list is searched whenever we need an available dquot. Dquots are
211 * removed from the list as soon as they are used again, and
212 * dqstats.free_dquots gives the number of dquots on the list. When
213 * dquot is invalidated it's completely released from memory.
214 *
215 * Dquots with a specific identity (device, type and id) are placed on
216 * one of the dquot_hash[] hash chains. The provides an efficient search
217 * mechanism to locate a specific dquot.
218 */
219
220static LIST_HEAD(inuse_list);
221static LIST_HEAD(free_dquots);
222static unsigned int dq_hash_bits, dq_hash_mask;
223static struct hlist_head *dquot_hash;
224
225struct dqstats dqstats;
08d0350c 226EXPORT_SYMBOL(dqstats);
1da177e4 227
1da177e4
LT		 228static inline unsigned int
229hashfn(const struct super_block *sb, unsigned int id, int type)
230{
231 unsigned long tmp;
232
233 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
234 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
235}
236
237/*
238 * Following list functions expect dq_list_lock to be held
239 */
240static inline void insert_dquot_hash(struct dquot *dquot)
241{
268157ba
JK		 242 struct hlist_head *head;
243 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
1da177e4
LT		 244 hlist_add_head(&dquot->dq_hash, head);
245}
246
247static inline void remove_dquot_hash(struct dquot *dquot)
248{
249 hlist_del_init(&dquot->dq_hash);
250}
251
7a2435d8
JK		 252static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
253 unsigned int id, int type)
1da177e4
LT		 254{
255 struct hlist_node *node;
256 struct dquot *dquot;
257
258 hlist_for_each (node, dquot_hash+hashent) {
259 dquot = hlist_entry(node, struct dquot, dq_hash);
268157ba
JK		 260 if (dquot->dq_sb == sb && dquot->dq_id == id &&
261 dquot->dq_type == type)
1da177e4
LT		 262 return dquot;
263 }
dd6f3c6d 264 return NULL;
1da177e4
LT		 265}
266
267/* Add a dquot to the tail of the free list */
268static inline void put_dquot_last(struct dquot *dquot)
269{
8e13059a 270 list_add_tail(&dquot->dq_free, &free_dquots);
1da177e4
LT		 271 dqstats.free_dquots++;
272}
273
274static inline void remove_free_dquot(struct dquot *dquot)
275{
276 if (list_empty(&dquot->dq_free))
277 return;
278 list_del_init(&dquot->dq_free);
279 dqstats.free_dquots--;
280}
281
282static inline void put_inuse(struct dquot *dquot)
283{
284 /* We add to the back of inuse list so we don't have to restart
285 * when traversing this list and we block */
8e13059a 286 list_add_tail(&dquot->dq_inuse, &inuse_list);
1da177e4
LT		 287 dqstats.allocated_dquots++;
288}
289
290static inline void remove_inuse(struct dquot *dquot)
291{
292 dqstats.allocated_dquots--;
293 list_del(&dquot->dq_inuse);
294}
295/*
296 * End of list functions needing dq_list_lock
297 */
298
299static void wait_on_dquot(struct dquot *dquot)
300{
d3be915f
IM		 301 mutex_lock(&dquot->dq_lock);
302 mutex_unlock(&dquot->dq_lock);
1da177e4
LT		 303}
304
03f6e92b
JK		 305static inline int dquot_dirty(struct dquot *dquot)
306{
307 return test_bit(DQ_MOD_B, &dquot->dq_flags);
308}
309
310static inline int mark_dquot_dirty(struct dquot *dquot)
311{
312 return dquot->dq_sb->dq_op->mark_dirty(dquot);
313}
1da177e4
LT		 314
315int dquot_mark_dquot_dirty(struct dquot *dquot)
316{
317 spin_lock(&dq_list_lock);
318 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
319 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
320 info[dquot->dq_type].dqi_dirty_list);
321 spin_unlock(&dq_list_lock);
322 return 0;
323}
08d0350c 324EXPORT_SYMBOL(dquot_mark_dquot_dirty);
1da177e4 325
dc52dd3a
DM		 326/* Dirtify all the dquots - this can block when journalling */
327static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
328{
329 int ret, err, cnt;
330
331 ret = err = 0;
332 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
333 if (dquot[cnt])
334 /* Even in case of error we have to continue */
335 ret = mark_dquot_dirty(dquot[cnt]);
336 if (!err)
337 err = ret;
338 }
339 return err;
340}
341
342static inline void dqput_all(struct dquot **dquot)
343{
344 unsigned int cnt;
345
346 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
347 dqput(dquot[cnt]);
348}
349
1da177e4
LT		 350/* This function needs dq_list_lock */
351static inline int clear_dquot_dirty(struct dquot *dquot)
352{
353 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
354 return 0;
355 list_del_init(&dquot->dq_dirty);
356 return 1;
357}
358
359void mark_info_dirty(struct super_block *sb, int type)
360{
361 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
362}
363EXPORT_SYMBOL(mark_info_dirty);
364
365/*
366 * Read dquot from disk and alloc space for it
367 */
368
369int dquot_acquire(struct dquot *dquot)
370{
371 int ret = 0, ret2 = 0;
372 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
373
d3be915f
IM		 374 mutex_lock(&dquot->dq_lock);
375 mutex_lock(&dqopt->dqio_mutex);
1da177e4
LT		 376 if (!test_bit(DQ_READ_B, &dquot->dq_flags))
377 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
378 if (ret < 0)
379 goto out_iolock;
380 set_bit(DQ_READ_B, &dquot->dq_flags);
381 /* Instantiate dquot if needed */
382 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
383 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
384 /* Write the info if needed */
268157ba
JK		 385 if (info_dirty(&dqopt->info[dquot->dq_type])) {
386 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
387 dquot->dq_sb, dquot->dq_type);
388 }
1da177e4
LT		 389 if (ret < 0)
390 goto out_iolock;
391 if (ret2 < 0) {
392 ret = ret2;
393 goto out_iolock;
394 }
395 }
396 set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
397out_iolock:
d3be915f
IM		 398 mutex_unlock(&dqopt->dqio_mutex);
399 mutex_unlock(&dquot->dq_lock);
1da177e4
LT		 400 return ret;
401}
08d0350c 402EXPORT_SYMBOL(dquot_acquire);
1da177e4
LT		 403
404/*
405 * Write dquot to disk
406 */
407int dquot_commit(struct dquot *dquot)
408{
409 int ret = 0, ret2 = 0;
410 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
411
d3be915f 412 mutex_lock(&dqopt->dqio_mutex);
1da177e4
LT		 413 spin_lock(&dq_list_lock);
414 if (!clear_dquot_dirty(dquot)) {
415 spin_unlock(&dq_list_lock);
416 goto out_sem;
417 }
418 spin_unlock(&dq_list_lock);
419 /* Inactive dquot can be only if there was error during read/init
420 * => we have better not writing it */
421 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
422 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
268157ba
JK		 423 if (info_dirty(&dqopt->info[dquot->dq_type])) {
424 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
425 dquot->dq_sb, dquot->dq_type);
426 }
1da177e4
LT		 427 if (ret >= 0)
428 ret = ret2;
429 }
430out_sem:
d3be915f 431 mutex_unlock(&dqopt->dqio_mutex);
1da177e4
LT		 432 return ret;
433}
08d0350c 434EXPORT_SYMBOL(dquot_commit);
1da177e4
LT		 435
436/*
437 * Release dquot
438 */
439int dquot_release(struct dquot *dquot)
440{
441 int ret = 0, ret2 = 0;
442 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
443
d3be915f 444 mutex_lock(&dquot->dq_lock);
1da177e4
LT		 445 /* Check whether we are not racing with some other dqget() */
446 if (atomic_read(&dquot->dq_count) > 1)
447 goto out_dqlock;
d3be915f 448 mutex_lock(&dqopt->dqio_mutex);
1da177e4
LT		 449 if (dqopt->ops[dquot->dq_type]->release_dqblk) {
450 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
451 /* Write the info */
268157ba
JK		 452 if (info_dirty(&dqopt->info[dquot->dq_type])) {
453 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
454 dquot->dq_sb, dquot->dq_type);
455 }
1da177e4
LT		 456 if (ret >= 0)
457 ret = ret2;
458 }
459 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
d3be915f 460 mutex_unlock(&dqopt->dqio_mutex);
1da177e4 461out_dqlock:
d3be915f 462 mutex_unlock(&dquot->dq_lock);
1da177e4
LT		 463 return ret;
464}
08d0350c 465EXPORT_SYMBOL(dquot_release);
1da177e4 466
7d9056ba 467void dquot_destroy(struct dquot *dquot)
74f783af
JK		 468{
469 kmem_cache_free(dquot_cachep, dquot);
470}
7d9056ba 471EXPORT_SYMBOL(dquot_destroy);
74f783af
JK		 472
473static inline void do_destroy_dquot(struct dquot *dquot)
474{
475 dquot->dq_sb->dq_op->destroy_dquot(dquot);
476}
477
1da177e4
LT		 478/* Invalidate all dquots on the list. Note that this function is called after
479 * quota is disabled and pointers from inodes removed so there cannot be new
6362e4d4
JK		 480 * quota users. There can still be some users of quotas due to inodes being
481 * just deleted or pruned by prune_icache() (those are not attached to any
cc33412f 482 * list) or parallel quotactl call. We have to wait for such users.
6362e4d4 483 */
1da177e4
LT		 484static void invalidate_dquots(struct super_block *sb, int type)
485{
c33ed271 486 struct dquot *dquot, *tmp;
1da177e4 487
6362e4d4 488restart:
1da177e4 489 spin_lock(&dq_list_lock);
c33ed271 490 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
1da177e4
LT		 491 if (dquot->dq_sb != sb)
492 continue;
493 if (dquot->dq_type != type)
494 continue;
6362e4d4
JK		 495 /* Wait for dquot users */
496 if (atomic_read(&dquot->dq_count)) {
497 DEFINE_WAIT(wait);
498
499 atomic_inc(&dquot->dq_count);
500 prepare_to_wait(&dquot->dq_wait_unused, &wait,
501 TASK_UNINTERRUPTIBLE);
502 spin_unlock(&dq_list_lock);
503 /* Once dqput() wakes us up, we know it's time to free
504 * the dquot.
505 * IMPORTANT: we rely on the fact that there is always
506 * at most one process waiting for dquot to free.
507 * Otherwise dq_count would be > 1 and we would never
508 * wake up.
509 */
510 if (atomic_read(&dquot->dq_count) > 1)
511 schedule();
512 finish_wait(&dquot->dq_wait_unused, &wait);
513 dqput(dquot);
514 /* At this moment dquot() need not exist (it could be
515 * reclaimed by prune_dqcache(). Hence we must
516 * restart. */
517 goto restart;
518 }
519 /*
520 * Quota now has no users and it has been written on last
521 * dqput()
522 */
1da177e4
LT		 523 remove_dquot_hash(dquot);
524 remove_free_dquot(dquot);
525 remove_inuse(dquot);
74f783af 526 do_destroy_dquot(dquot);
1da177e4
LT		 527 }
528 spin_unlock(&dq_list_lock);
529}
530
12c77527
JK		 531/* Call callback for every active dquot on given filesystem */
532int dquot_scan_active(struct super_block *sb,
533 int (*fn)(struct dquot *dquot, unsigned long priv),
534 unsigned long priv)
535{
536 struct dquot *dquot, *old_dquot = NULL;
537 int ret = 0;
538
539 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
540 spin_lock(&dq_list_lock);
541 list_for_each_entry(dquot, &inuse_list, dq_inuse) {
542 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
543 continue;
544 if (dquot->dq_sb != sb)
545 continue;
546 /* Now we have active dquot so we can just increase use count */
547 atomic_inc(&dquot->dq_count);
548 dqstats.lookups++;
549 spin_unlock(&dq_list_lock);
550 dqput(old_dquot);
551 old_dquot = dquot;
552 ret = fn(dquot, priv);
553 if (ret < 0)
554 goto out;
555 spin_lock(&dq_list_lock);
556 /* We are safe to continue now because our dquot could not
557 * be moved out of the inuse list while we hold the reference */
558 }
559 spin_unlock(&dq_list_lock);
560out:
561 dqput(old_dquot);
562 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
563 return ret;
564}
08d0350c 565EXPORT_SYMBOL(dquot_scan_active);
12c77527 566
1da177e4
LT		 567int vfs_quota_sync(struct super_block *sb, int type)
568{
569 struct list_head *dirty;
570 struct dquot *dquot;
571 struct quota_info *dqopt = sb_dqopt(sb);
572 int cnt;
573
d3be915f 574 mutex_lock(&dqopt->dqonoff_mutex);
1da177e4
LT		 575 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
576 if (type != -1 && cnt != type)
577 continue;
f55abc0f 578 if (!sb_has_quota_active(sb, cnt))
1da177e4
LT		 579 continue;
580 spin_lock(&dq_list_lock);
581 dirty = &dqopt->info[cnt].dqi_dirty_list;
582 while (!list_empty(dirty)) {
268157ba
JK		 583 dquot = list_first_entry(dirty, struct dquot,
584 dq_dirty);
1da177e4
LT		 585 /* Dirty and inactive can be only bad dquot... */
586 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
587 clear_dquot_dirty(dquot);
588 continue;
589 }
590 /* Now we have active dquot from which someone is
591 * holding reference so we can safely just increase
592 * use count */
593 atomic_inc(&dquot->dq_count);
594 dqstats.lookups++;
595 spin_unlock(&dq_list_lock);
596 sb->dq_op->write_dquot(dquot);
597 dqput(dquot);
598 spin_lock(&dq_list_lock);
599 }
600 spin_unlock(&dq_list_lock);
601 }
602
603 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
f55abc0f
JK		 604 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
605 && info_dirty(&dqopt->info[cnt]))
1da177e4
LT		 606 sb->dq_op->write_info(sb, cnt);
607 spin_lock(&dq_list_lock);
608 dqstats.syncs++;
609 spin_unlock(&dq_list_lock);
d3be915f 610 mutex_unlock(&dqopt->dqonoff_mutex);
1da177e4
LT		 611
612 return 0;
613}
08d0350c 614EXPORT_SYMBOL(vfs_quota_sync);
1da177e4
LT		 615
616/* Free unused dquots from cache */
617static void prune_dqcache(int count)
618{
619 struct list_head *head;
620 struct dquot *dquot;
621
622 head = free_dquots.prev;
623 while (head != &free_dquots && count) {
624 dquot = list_entry(head, struct dquot, dq_free);
625 remove_dquot_hash(dquot);
626 remove_free_dquot(dquot);
627 remove_inuse(dquot);
74f783af 628 do_destroy_dquot(dquot);
1da177e4
LT		 629 count--;
630 head = free_dquots.prev;
631 }
632}
633
634/*
635 * This is called from kswapd when we think we need some
636 * more memory
637 */
638
27496a8c 639static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
1da177e4
LT		 640{
641 if (nr) {
642 spin_lock(&dq_list_lock);
643 prune_dqcache(nr);
644 spin_unlock(&dq_list_lock);
645 }
646 return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
647}
648
8e1f936b
RR		 649static struct shrinker dqcache_shrinker = {
650 .shrink = shrink_dqcache_memory,
651 .seeks = DEFAULT_SEEKS,
652};
653
1da177e4
LT		 654/*
655 * Put reference to dquot
656 * NOTE: If you change this function please check whether dqput_blocks() works right...
1da177e4 657 */
3d9ea253 658void dqput(struct dquot *dquot)
1da177e4 659{
b48d3805
JK		 660 int ret;
661
1da177e4
LT		 662 if (!dquot)
663 return;
664#ifdef __DQUOT_PARANOIA
665 if (!atomic_read(&dquot->dq_count)) {
666 printk("VFS: dqput: trying to free free dquot\n");
667 printk("VFS: device %s, dquot of %s %d\n",
668 dquot->dq_sb->s_id,
669 quotatypes[dquot->dq_type],
670 dquot->dq_id);
671 BUG();
672 }
673#endif
674
675 spin_lock(&dq_list_lock);
676 dqstats.drops++;
677 spin_unlock(&dq_list_lock);
678we_slept:
679 spin_lock(&dq_list_lock);
680 if (atomic_read(&dquot->dq_count) > 1) {
681 /* We have more than one user... nothing to do */
682 atomic_dec(&dquot->dq_count);
6362e4d4 683 /* Releasing dquot during quotaoff phase? */
f55abc0f 684 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
6362e4d4
JK		 685 atomic_read(&dquot->dq_count) == 1)
686 wake_up(&dquot->dq_wait_unused);
1da177e4
LT		 687 spin_unlock(&dq_list_lock);
688 return;
689 }
690 /* Need to release dquot? */
691 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
692 spin_unlock(&dq_list_lock);
693 /* Commit dquot before releasing */
b48d3805
JK		 694 ret = dquot->dq_sb->dq_op->write_dquot(dquot);
695 if (ret < 0) {
696 printk(KERN_ERR "VFS: cannot write quota structure on "
697 "device %s (error %d). Quota may get out of "
698 "sync!\n", dquot->dq_sb->s_id, ret);
699 /*
700 * We clear dirty bit anyway, so that we avoid
701 * infinite loop here
702 */
703 spin_lock(&dq_list_lock);
704 clear_dquot_dirty(dquot);
705 spin_unlock(&dq_list_lock);
706 }
1da177e4
LT		 707 goto we_slept;
708 }
709 /* Clear flag in case dquot was inactive (something bad happened) */
710 clear_dquot_dirty(dquot);
711 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
712 spin_unlock(&dq_list_lock);
713 dquot->dq_sb->dq_op->release_dquot(dquot);
714 goto we_slept;
715 }
716 atomic_dec(&dquot->dq_count);
717#ifdef __DQUOT_PARANOIA
718 /* sanity check */
8abf6a47 719 BUG_ON(!list_empty(&dquot->dq_free));
1da177e4
LT		 720#endif
721 put_dquot_last(dquot);
722 spin_unlock(&dq_list_lock);
723}
08d0350c 724EXPORT_SYMBOL(dqput);
1da177e4 725
7d9056ba 726struct dquot *dquot_alloc(struct super_block *sb, int type)
74f783af
JK		 727{
728 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
729}
7d9056ba 730EXPORT_SYMBOL(dquot_alloc);
74f783af 731
1da177e4
LT		 732static struct dquot *get_empty_dquot(struct super_block *sb, int type)
733{
734 struct dquot *dquot;
735
74f783af 736 dquot = sb->dq_op->alloc_dquot(sb, type);
1da177e4 737 if(!dquot)
dd6f3c6d 738 return NULL;
1da177e4 739
d3be915f 740 mutex_init(&dquot->dq_lock);
1da177e4
LT		 741 INIT_LIST_HEAD(&dquot->dq_free);
742 INIT_LIST_HEAD(&dquot->dq_inuse);
743 INIT_HLIST_NODE(&dquot->dq_hash);
744 INIT_LIST_HEAD(&dquot->dq_dirty);
6362e4d4 745 init_waitqueue_head(&dquot->dq_wait_unused);
1da177e4
LT		 746 dquot->dq_sb = sb;
747 dquot->dq_type = type;
748 atomic_set(&dquot->dq_count, 1);
749
750 return dquot;
751}
752
753/*
754 * Get reference to dquot
cc33412f
JK		 755 *
756 * Locking is slightly tricky here. We are guarded from parallel quotaoff()
757 * destroying our dquot by:
758 * a) checking for quota flags under dq_list_lock and
759 * b) getting a reference to dquot before we release dq_list_lock
1da177e4 760 */
3d9ea253 761struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
1da177e4
LT		 762{
763 unsigned int hashent = hashfn(sb, id, type);
dd6f3c6d 764 struct dquot *dquot = NULL, *empty = NULL;
1da177e4 765
f55abc0f 766 if (!sb_has_quota_active(sb, type))
dd6f3c6d 767 return NULL;
1da177e4
LT		 768we_slept:
769 spin_lock(&dq_list_lock);
cc33412f
JK		 770 spin_lock(&dq_state_lock);
771 if (!sb_has_quota_active(sb, type)) {
772 spin_unlock(&dq_state_lock);
773 spin_unlock(&dq_list_lock);
774 goto out;
775 }
776 spin_unlock(&dq_state_lock);
777
dd6f3c6d
JK		 778 dquot = find_dquot(hashent, sb, id, type);
779 if (!dquot) {
780 if (!empty) {
1da177e4 781 spin_unlock(&dq_list_lock);
dd6f3c6d
JK		 782 empty = get_empty_dquot(sb, type);
783 if (!empty)
1da177e4
LT		 784 schedule(); /* Try to wait for a moment... */
785 goto we_slept;
786 }
787 dquot = empty;
dd6f3c6d 788 empty = NULL;
1da177e4
LT		 789 dquot->dq_id = id;
790 /* all dquots go on the inuse_list */
791 put_inuse(dquot);
792 /* hash it first so it can be found */
793 insert_dquot_hash(dquot);
794 dqstats.lookups++;
795 spin_unlock(&dq_list_lock);
796 } else {
797 if (!atomic_read(&dquot->dq_count))
798 remove_free_dquot(dquot);
799 atomic_inc(&dquot->dq_count);
800 dqstats.cache_hits++;
801 dqstats.lookups++;
802 spin_unlock(&dq_list_lock);
1da177e4 803 }
268157ba
JK		 804 /* Wait for dq_lock - after this we know that either dquot_release() is
805 * already finished or it will be canceled due to dq_count > 1 test */
1da177e4 806 wait_on_dquot(dquot);
268157ba
JK		 807 /* Read the dquot / allocate space in quota file */
808 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) &&
809 sb->dq_op->acquire_dquot(dquot) < 0) {
1da177e4 810 dqput(dquot);
dd6f3c6d 811 dquot = NULL;
cc33412f 812 goto out;
1da177e4
LT		 813 }
814#ifdef __DQUOT_PARANOIA
8abf6a47 815 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */
1da177e4 816#endif
cc33412f
JK		 817out:
818 if (empty)
819 do_destroy_dquot(empty);
1da177e4
LT		 820
821 return dquot;
822}
08d0350c 823EXPORT_SYMBOL(dqget);
1da177e4
LT		 824
825static int dqinit_needed(struct inode *inode, int type)
826{
827 int cnt;
828
829 if (IS_NOQUOTA(inode))
830 return 0;
831 if (type != -1)
dd6f3c6d 832 return !inode->i_dquot[type];
1da177e4 833 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
dd6f3c6d 834 if (!inode->i_dquot[cnt])
1da177e4
LT		 835 return 1;
836 return 0;
837}
838
d3be915f 839/* This routine is guarded by dqonoff_mutex mutex */
1da177e4
LT		 840static void add_dquot_ref(struct super_block *sb, int type)
841{
941d2380 842 struct inode *inode, *old_inode = NULL;
1da177e4 843
d003fb70
CH		 844 spin_lock(&inode_lock);
845 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
b6fac63c 846 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW))
aabb8fdb 847 continue;
d003fb70
CH		 848 if (!atomic_read(&inode->i_writecount))
849 continue;
850 if (!dqinit_needed(inode, type))
851 continue;
d003fb70
CH		 852
853 __iget(inode);
854 spin_unlock(&inode_lock);
855
941d2380 856 iput(old_inode);
d003fb70 857 sb->dq_op->initialize(inode, type);
941d2380
JK		 858 /* We hold a reference to 'inode' so it couldn't have been
859 * removed from s_inodes list while we dropped the inode_lock.
860 * We cannot iput the inode now as we can be holding the last
861 * reference and we cannot iput it under inode_lock. So we
862 * keep the reference and iput it later. */
863 old_inode = inode;
864 spin_lock(&inode_lock);
1da177e4 865 }
d003fb70 866 spin_unlock(&inode_lock);
941d2380 867 iput(old_inode);
1da177e4
LT		 868}
869
268157ba
JK		 870/*
871 * Return 0 if dqput() won't block.
872 * (note that 1 doesn't necessarily mean blocking)
873 */
1da177e4
LT		 874static inline int dqput_blocks(struct dquot *dquot)
875{
876 if (atomic_read(&dquot->dq_count) <= 1)
877 return 1;
878 return 0;
879}
880
268157ba
JK		 881/*
882 * Remove references to dquots from inode and add dquot to list for freeing
883 * if we have the last referece to dquot
884 * We can't race with anybody because we hold dqptr_sem for writing...
885 */
e5f00f42
AB		 886static int remove_inode_dquot_ref(struct inode *inode, int type,
887 struct list_head *tofree_head)
1da177e4
LT		 888{
889 struct dquot *dquot = inode->i_dquot[type];
890
dd6f3c6d
JK		 891 inode->i_dquot[type] = NULL;
892 if (dquot) {
1da177e4
LT		 893 if (dqput_blocks(dquot)) {
894#ifdef __DQUOT_PARANOIA
895 if (atomic_read(&dquot->dq_count) != 1)
896 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
897#endif
898 spin_lock(&dq_list_lock);
268157ba
JK		 899 /* As dquot must have currently users it can't be on
900 * the free list... */
901 list_add(&dquot->dq_free, tofree_head);
1da177e4
LT		 902 spin_unlock(&dq_list_lock);
903 return 1;
904 }
905 else
906 dqput(dquot); /* We have guaranteed we won't block */
907 }
908 return 0;
909}
910
268157ba
JK		 911/*
912 * Free list of dquots
913 * Dquots are removed from inodes and no new references can be got so we are
914 * the only ones holding reference
915 */
1da177e4
LT		 916static void put_dquot_list(struct list_head *tofree_head)
917{
918 struct list_head *act_head;
919 struct dquot *dquot;
920
921 act_head = tofree_head->next;
1da177e4
LT		 922 while (act_head != tofree_head) {
923 dquot = list_entry(act_head, struct dquot, dq_free);
924 act_head = act_head->next;
268157ba
JK		 925 /* Remove dquot from the list so we won't have problems... */
926 list_del_init(&dquot->dq_free);
1da177e4
LT		 927 dqput(dquot);
928 }
929}
930
fb58b731
CH		 931static void remove_dquot_ref(struct super_block *sb, int type,
932 struct list_head *tofree_head)
933{
934 struct inode *inode;
935
936 spin_lock(&inode_lock);
937 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
aabb8fdb
NP		 938 /*
939 * We have to scan also I_NEW inodes because they can already
940 * have quota pointer initialized. Luckily, we need to touch
941 * only quota pointers and these have separate locking
942 * (dqptr_sem).
943 */
fb58b731
CH		 944 if (!IS_NOQUOTA(inode))
945 remove_inode_dquot_ref(inode, type, tofree_head);
946 }
947 spin_unlock(&inode_lock);
948}
949
1da177e4
LT		 950/* Gather all references from inodes and drop them */
951static void drop_dquot_ref(struct super_block *sb, int type)
952{
953 LIST_HEAD(tofree_head);
954
fb58b731
CH		 955 if (sb->dq_op) {
956 down_write(&sb_dqopt(sb)->dqptr_sem);
957 remove_dquot_ref(sb, type, &tofree_head);
958 up_write(&sb_dqopt(sb)->dqptr_sem);
959 put_dquot_list(&tofree_head);
960 }
1da177e4
LT		 961}
962
12095460 963static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
1da177e4
LT		 964{
965 dquot->dq_dqb.dqb_curinodes += number;
966}
967
968static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
969{
970 dquot->dq_dqb.dqb_curspace += number;
971}
972
f18df228
MC		 973static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
974{
975 dquot->dq_dqb.dqb_rsvspace += number;
976}
977
740d9dcd
MC		 978/*
979 * Claim reserved quota space
980 */
981static void dquot_claim_reserved_space(struct dquot *dquot,
982 qsize_t number)
983{
984 WARN_ON(dquot->dq_dqb.dqb_rsvspace < number);
985 dquot->dq_dqb.dqb_curspace += number;
986 dquot->dq_dqb.dqb_rsvspace -= number;
987}
988
989static inline
990void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
991{
992 dquot->dq_dqb.dqb_rsvspace -= number;
993}
994
7a2435d8 995static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
1da177e4 996{
db49d2df
JK		 997 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
998 dquot->dq_dqb.dqb_curinodes >= number)
1da177e4
LT		 999 dquot->dq_dqb.dqb_curinodes -= number;
1000 else
1001 dquot->dq_dqb.dqb_curinodes = 0;
1002 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
1003 dquot->dq_dqb.dqb_itime = (time_t) 0;
1004 clear_bit(DQ_INODES_B, &dquot->dq_flags);
1005}
1006
7a2435d8 1007static void dquot_decr_space(struct dquot *dquot, qsize_t number)
1da177e4 1008{
db49d2df
JK		 1009 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
1010 dquot->dq_dqb.dqb_curspace >= number)
1da177e4
LT		 1011 dquot->dq_dqb.dqb_curspace -= number;
1012 else
1013 dquot->dq_dqb.dqb_curspace = 0;
12095460 1014 if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
1da177e4
LT		 1015 dquot->dq_dqb.dqb_btime = (time_t) 0;
1016 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
1017}
1018
c525460e
JK		 1019static int warning_issued(struct dquot *dquot, const int warntype)
1020{
1021 int flag = (warntype == QUOTA_NL_BHARDWARN ||
1022 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
1023 ((warntype == QUOTA_NL_IHARDWARN ||
1024 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
1025
1026 if (!flag)
1027 return 0;
1028 return test_and_set_bit(flag, &dquot->dq_flags);
1029}
1030
8e893469 1031#ifdef CONFIG_PRINT_QUOTA_WARNING
1da177e4
LT		 1032static int flag_print_warnings = 1;
1033
7a2435d8 1034static int need_print_warning(struct dquot *dquot)
1da177e4
LT		 1035{
1036 if (!flag_print_warnings)
1037 return 0;
1038
1039 switch (dquot->dq_type) {
1040 case USRQUOTA:
da9592ed 1041 return current_fsuid() == dquot->dq_id;
1da177e4
LT		 1042 case GRPQUOTA:
1043 return in_group_p(dquot->dq_id);
1044 }
1045 return 0;
1046}
1047
1da177e4 1048/* Print warning to user which exceeded quota */
c525460e 1049static void print_warning(struct dquot *dquot, const int warntype)
1da177e4
LT		 1050{
1051 char *msg = NULL;
24ec839c 1052 struct tty_struct *tty;
1da177e4 1053
657d3bfa
JK		 1054 if (warntype == QUOTA_NL_IHARDBELOW ||
1055 warntype == QUOTA_NL_ISOFTBELOW ||
1056 warntype == QUOTA_NL_BHARDBELOW ||
1057 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
1da177e4
LT		 1058 return;
1059
24ec839c
PZ		 1060 tty = get_current_tty();
1061 if (!tty)
452a00d2 1062 return;
24ec839c 1063 tty_write_message(tty, dquot->dq_sb->s_id);
8e893469 1064 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
24ec839c 1065 tty_write_message(tty, ": warning, ");
1da177e4 1066 else
24ec839c
PZ		 1067 tty_write_message(tty, ": write failed, ");
1068 tty_write_message(tty, quotatypes[dquot->dq_type]);
1da177e4 1069 switch (warntype) {
8e893469 1070 case QUOTA_NL_IHARDWARN:
1da177e4
LT		 1071 msg = " file limit reached.\r\n";
1072 break;
8e893469 1073 case QUOTA_NL_ISOFTLONGWARN:
1da177e4
LT		 1074 msg = " file quota exceeded too long.\r\n";
1075 break;
8e893469 1076 case QUOTA_NL_ISOFTWARN:
1da177e4
LT		 1077 msg = " file quota exceeded.\r\n";
1078 break;
8e893469 1079 case QUOTA_NL_BHARDWARN:
1da177e4
LT		 1080 msg = " block limit reached.\r\n";
1081 break;
8e893469 1082 case QUOTA_NL_BSOFTLONGWARN:
1da177e4
LT		 1083 msg = " block quota exceeded too long.\r\n";
1084 break;
8e893469 1085 case QUOTA_NL_BSOFTWARN:
1da177e4
LT		 1086 msg = " block quota exceeded.\r\n";
1087 break;
1088 }
24ec839c 1089 tty_write_message(tty, msg);
452a00d2 1090 tty_kref_put(tty);
1da177e4 1091}
8e893469
JK		 1092#endif
1093
f18df228
MC		 1094/*
1095 * Write warnings to the console and send warning messages over netlink.
1096 *
1097 * Note that this function can sleep.
1098 */
7a2435d8 1099static void flush_warnings(struct dquot *const *dquots, char *warntype)
1da177e4 1100{
86e931a3 1101 struct dquot *dq;
1da177e4
LT		 1102 int i;
1103
86e931a3
SW		 1104 for (i = 0; i < MAXQUOTAS; i++) {
1105 dq = dquots[i];
1106 if (dq && warntype[i] != QUOTA_NL_NOWARN &&
1107 !warning_issued(dq, warntype[i])) {
8e893469 1108#ifdef CONFIG_PRINT_QUOTA_WARNING
86e931a3 1109 print_warning(dq, warntype[i]);
8e893469 1110#endif
86e931a3
SW		 1111 quota_send_warning(dq->dq_type, dq->dq_id,
1112 dq->dq_sb->s_dev, warntype[i]);
8e893469 1113 }
86e931a3 1114 }
1da177e4
LT		 1115}
1116
7a2435d8 1117static int ignore_hardlimit(struct dquot *dquot)
1da177e4
LT		 1118{
1119 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
1120
1121 return capable(CAP_SYS_RESOURCE) &&
268157ba
JK		 1122 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
1123 !(info->dqi_flags & V1_DQF_RSQUASH));
1da177e4
LT		 1124}
1125
1126/* needs dq_data_lock */
12095460 1127static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
1da177e4 1128{
268157ba
JK		 1129 qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
1130
8e893469 1131 *warntype = QUOTA_NL_NOWARN;
f55abc0f
JK		 1132 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
1133 test_bit(DQ_FAKE_B, &dquot->dq_flags))
1da177e4
LT		 1134 return QUOTA_OK;
1135
1136 if (dquot->dq_dqb.dqb_ihardlimit &&
268157ba 1137 newinodes > dquot->dq_dqb.dqb_ihardlimit &&
1da177e4 1138 !ignore_hardlimit(dquot)) {
8e893469 1139 *warntype = QUOTA_NL_IHARDWARN;
1da177e4
LT		 1140 return NO_QUOTA;
1141 }
1142
1143 if (dquot->dq_dqb.dqb_isoftlimit &&
268157ba
JK		 1144 newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1145 dquot->dq_dqb.dqb_itime &&
1146 get_seconds() >= dquot->dq_dqb.dqb_itime &&
1da177e4 1147 !ignore_hardlimit(dquot)) {
8e893469 1148 *warntype = QUOTA_NL_ISOFTLONGWARN;
1da177e4
LT		 1149 return NO_QUOTA;
1150 }
1151
1152 if (dquot->dq_dqb.dqb_isoftlimit &&
268157ba 1153 newinodes > dquot->dq_dqb.dqb_isoftlimit &&
1da177e4 1154 dquot->dq_dqb.dqb_itime == 0) {
8e893469 1155 *warntype = QUOTA_NL_ISOFTWARN;
268157ba
JK		 1156 dquot->dq_dqb.dqb_itime = get_seconds() +
1157 sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
1da177e4
LT		 1158 }
1159
1160 return QUOTA_OK;
1161}
1162
1163/* needs dq_data_lock */
1164static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
1165{
f18df228 1166 qsize_t tspace;
268157ba 1167 struct super_block *sb = dquot->dq_sb;
f18df228 1168
8e893469 1169 *warntype = QUOTA_NL_NOWARN;
268157ba 1170 if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
f55abc0f 1171 test_bit(DQ_FAKE_B, &dquot->dq_flags))
1da177e4
LT		 1172 return QUOTA_OK;
1173
f18df228
MC		 1174 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
1175 + space;
1176
1da177e4 1177 if (dquot->dq_dqb.dqb_bhardlimit &&
f18df228 1178 tspace > dquot->dq_dqb.dqb_bhardlimit &&
1da177e4
LT		 1179 !ignore_hardlimit(dquot)) {
1180 if (!prealloc)
8e893469 1181 *warntype = QUOTA_NL_BHARDWARN;
1da177e4
LT		 1182 return NO_QUOTA;
1183 }
1184
1185 if (dquot->dq_dqb.dqb_bsoftlimit &&
f18df228 1186 tspace > dquot->dq_dqb.dqb_bsoftlimit &&
268157ba
JK		 1187 dquot->dq_dqb.dqb_btime &&
1188 get_seconds() >= dquot->dq_dqb.dqb_btime &&
1da177e4
LT		 1189 !ignore_hardlimit(dquot)) {
1190 if (!prealloc)
8e893469 1191 *warntype = QUOTA_NL_BSOFTLONGWARN;
1da177e4
LT		 1192 return NO_QUOTA;
1193 }
1194
1195 if (dquot->dq_dqb.dqb_bsoftlimit &&
f18df228 1196 tspace > dquot->dq_dqb.dqb_bsoftlimit &&
1da177e4
LT		 1197 dquot->dq_dqb.dqb_btime == 0) {
1198 if (!prealloc) {
8e893469 1199 *warntype = QUOTA_NL_BSOFTWARN;
268157ba
JK		 1200 dquot->dq_dqb.dqb_btime = get_seconds() +
1201 sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
1da177e4
LT		 1202 }
1203 else
1204 /*
1205 * We don't allow preallocation to exceed softlimit so exceeding will
1206 * be always printed
1207 */
1208 return NO_QUOTA;
1209 }
1210
1211 return QUOTA_OK;
1212}
1213
12095460 1214static int info_idq_free(struct dquot *dquot, qsize_t inodes)
657d3bfa 1215{
268157ba
JK		 1216 qsize_t newinodes;
1217
657d3bfa 1218 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
f55abc0f
JK		 1219 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
1220 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
657d3bfa
JK		 1221 return QUOTA_NL_NOWARN;
1222
268157ba
JK		 1223 newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
1224 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
657d3bfa
JK		 1225 return QUOTA_NL_ISOFTBELOW;
1226 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
268157ba 1227 newinodes < dquot->dq_dqb.dqb_ihardlimit)
657d3bfa
JK		 1228 return QUOTA_NL_IHARDBELOW;
1229 return QUOTA_NL_NOWARN;
1230}
1231
1232static int info_bdq_free(struct dquot *dquot, qsize_t space)
1233{
1234 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
12095460 1235 dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
657d3bfa
JK		 1236 return QUOTA_NL_NOWARN;
1237
12095460 1238 if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
657d3bfa 1239 return QUOTA_NL_BSOFTBELOW;
12095460
JK		 1240 if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
1241 dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
657d3bfa
JK		 1242 return QUOTA_NL_BHARDBELOW;
1243 return QUOTA_NL_NOWARN;
1244}
1da177e4
LT		 1245/*
1246 * Initialize quota pointers in inode
cc33412f
JK		 1247 * We do things in a bit complicated way but by that we avoid calling
1248 * dqget() and thus filesystem callbacks under dqptr_sem.
1da177e4
LT		 1249 */
1250int dquot_initialize(struct inode *inode, int type)
1251{
1252 unsigned int id = 0;
1253 int cnt, ret = 0;
dd6f3c6d 1254 struct dquot *got[MAXQUOTAS] = { NULL, NULL };
cc33412f 1255 struct super_block *sb = inode->i_sb;
1da177e4 1256
d3be915f
IM		 1257 /* First test before acquiring mutex - solves deadlocks when we
1258 * re-enter the quota code and are already holding the mutex */
1da177e4
LT		 1259 if (IS_NOQUOTA(inode))
1260 return 0;
cc33412f
JK		 1261
1262 /* First get references to structures we might need. */
1263 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1264 if (type != -1 && cnt != type)
1265 continue;
1266 switch (cnt) {
1267 case USRQUOTA:
1268 id = inode->i_uid;
1269 break;
1270 case GRPQUOTA:
1271 id = inode->i_gid;
1272 break;
1273 }
1274 got[cnt] = dqget(sb, id, cnt);
1275 }
1276
1277 down_write(&sb_dqopt(sb)->dqptr_sem);
1da177e4
LT		 1278 /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
1279 if (IS_NOQUOTA(inode))
1280 goto out_err;
1281 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1282 if (type != -1 && cnt != type)
1283 continue;
cc33412f
JK		 1284 /* Avoid races with quotaoff() */
1285 if (!sb_has_quota_active(sb, cnt))
1286 continue;
dd6f3c6d 1287 if (!inode->i_dquot[cnt]) {
cc33412f 1288 inode->i_dquot[cnt] = got[cnt];
dd6f3c6d 1289 got[cnt] = NULL;
1da177e4
LT		 1290 }
1291 }
1292out_err:
cc33412f
JK		 1293 up_write(&sb_dqopt(sb)->dqptr_sem);
1294 /* Drop unused references */
dc52dd3a 1295 dqput_all(got);
1da177e4
LT		 1296 return ret;
1297}
08d0350c 1298EXPORT_SYMBOL(dquot_initialize);
1da177e4
LT		 1299
1300/*
1301 * Release all quotas referenced by inode
1da177e4 1302 */
cc33412f 1303int dquot_drop(struct inode *inode)
1da177e4
LT		 1304{
1305 int cnt;
cc33412f 1306 struct dquot *put[MAXQUOTAS];
1da177e4 1307
cc33412f 1308 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1da177e4 1309 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
cc33412f 1310 put[cnt] = inode->i_dquot[cnt];
dd6f3c6d 1311 inode->i_dquot[cnt] = NULL;
1da177e4
LT		 1312 }
1313 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
dc52dd3a 1314 dqput_all(put);
1da177e4
LT		 1315 return 0;
1316}
08d0350c 1317EXPORT_SYMBOL(dquot_drop);
1da177e4 1318
b85f4b87
JK		 1319/* Wrapper to remove references to quota structures from inode */
1320void vfs_dq_drop(struct inode *inode)
1321{
1322 /* Here we can get arbitrary inode from clear_inode() so we have
1323 * to be careful. OTOH we don't need locking as quota operations
1324 * are allowed to change only at mount time */
1325 if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op
1326 && inode->i_sb->dq_op->drop) {
1327 int cnt;
1328 /* Test before calling to rule out calls from proc and such
1329 * where we are not allowed to block. Note that this is
1330 * actually reliable test even without the lock - the caller
1331 * must assure that nobody can come after the DQUOT_DROP and
1332 * add quota pointers back anyway */
1333 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
dd6f3c6d 1334 if (inode->i_dquot[cnt])
b85f4b87
JK		 1335 break;
1336 if (cnt < MAXQUOTAS)
1337 inode->i_sb->dq_op->drop(inode);
1338 }
1339}
08d0350c 1340EXPORT_SYMBOL(vfs_dq_drop);
b85f4b87 1341
fd8fbfc1
DM		 1342/*
1343 * inode_reserved_space is managed internally by quota, and protected by
1344 * i_lock similar to i_blocks+i_bytes.
1345 */
1346static qsize_t *inode_reserved_space(struct inode * inode)
1347{
1348 /* Filesystem must explicitly define it's own method in order to use
1349 * quota reservation interface */
1350 BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
1351 return inode->i_sb->dq_op->get_reserved_space(inode);
1352}
1353
1354static void inode_add_rsv_space(struct inode *inode, qsize_t number)
1355{
1356 spin_lock(&inode->i_lock);
1357 *inode_reserved_space(inode) += number;
1358 spin_unlock(&inode->i_lock);
1359}
1360
1361
1362static void inode_claim_rsv_space(struct inode *inode, qsize_t number)
1363{
1364 spin_lock(&inode->i_lock);
1365 *inode_reserved_space(inode) -= number;
1366 __inode_add_bytes(inode, number);
1367 spin_unlock(&inode->i_lock);
1368}
1369
1370static void inode_sub_rsv_space(struct inode *inode, qsize_t number)
1371{
1372 spin_lock(&inode->i_lock);
1373 *inode_reserved_space(inode) -= number;
1374 spin_unlock(&inode->i_lock);
1375}
1376
1377static qsize_t inode_get_rsv_space(struct inode *inode)
1378{
1379 qsize_t ret;
05b5d898
JK		 1380
1381 if (!inode->i_sb->dq_op->get_reserved_space)
1382 return 0;
fd8fbfc1
DM		 1383 spin_lock(&inode->i_lock);
1384 ret = *inode_reserved_space(inode);
1385 spin_unlock(&inode->i_lock);
1386 return ret;
1387}
1388
1389static void inode_incr_space(struct inode *inode, qsize_t number,
1390 int reserve)
1391{
1392 if (reserve)
1393 inode_add_rsv_space(inode, number);
1394 else
1395 inode_add_bytes(inode, number);
1396}
1397
1398static void inode_decr_space(struct inode *inode, qsize_t number, int reserve)
1399{
1400 if (reserve)
1401 inode_sub_rsv_space(inode, number);
1402 else
1403 inode_sub_bytes(inode, number);
1404}
1405
1da177e4
LT		 1406/*
1407 * Following four functions update i_blocks+i_bytes fields and
1408 * quota information (together with appropriate checks)
1409 * NOTE: We absolutely rely on the fact that caller dirties
1410 * the inode (usually macros in quotaops.h care about this) and
1411 * holds a handle for the current transaction so that dquot write and
1412 * inode write go into the same transaction.
1413 */
1414
1415/*
1416 * This operation can block, but only after everything is updated
1417 */
f18df228
MC		 1418int __dquot_alloc_space(struct inode *inode, qsize_t number,
1419 int warn, int reserve)
1da177e4 1420{
f18df228 1421 int cnt, ret = QUOTA_OK;
1da177e4
LT		 1422 char warntype[MAXQUOTAS];
1423
fd8fbfc1
DM		 1424 /*
1425 * First test before acquiring mutex - solves deadlocks when we
1426 * re-enter the quota code and are already holding the mutex
1427 */
1428 if (IS_NOQUOTA(inode)) {
1429 inode_incr_space(inode, number, reserve);
1430 goto out;
1431 }
1432
1433 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1434 if (IS_NOQUOTA(inode)) {
1435 inode_incr_space(inode, number, reserve);
1436 goto out_unlock;
1437 }
1438
1da177e4 1439 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
8e893469 1440 warntype[cnt] = QUOTA_NL_NOWARN;
1da177e4 1441
1da177e4
LT		 1442 spin_lock(&dq_data_lock);
1443 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
dd6f3c6d 1444 if (!inode->i_dquot[cnt])
1da177e4 1445 continue;
f18df228
MC		 1446 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt)
1447 == NO_QUOTA) {
1448 ret = NO_QUOTA;
fd8fbfc1
DM		 1449 spin_unlock(&dq_data_lock);
1450 goto out_flush_warn;
f18df228 1451 }
1da177e4
LT		 1452 }
1453 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
dd6f3c6d 1454 if (!inode->i_dquot[cnt])
1da177e4 1455 continue;
f18df228
MC		 1456 if (reserve)
1457 dquot_resv_space(inode->i_dquot[cnt], number);
1458 else
1459 dquot_incr_space(inode->i_dquot[cnt], number);
1da177e4 1460 }
fd8fbfc1 1461 inode_incr_space(inode, number, reserve);
1da177e4 1462 spin_unlock(&dq_data_lock);
f18df228 1463
fd8fbfc1
DM		 1464 if (reserve)
1465 goto out_flush_warn;
dc52dd3a 1466 mark_all_dquot_dirty(inode->i_dquot);
fd8fbfc1
DM		 1467out_flush_warn:
1468 flush_warnings(inode->i_dquot, warntype);
f18df228 1469out_unlock:
1da177e4 1470 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
f18df228
MC		 1471out:
1472 return ret;
1473}
fd8fbfc1
DM		 1474
1475int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
1476{
1477 return __dquot_alloc_space(inode, number, warn, 0);
1478}
08d0350c 1479EXPORT_SYMBOL(dquot_alloc_space);
f18df228
MC		 1480
1481int dquot_reserve_space(struct inode *inode, qsize_t number, int warn)
1482{
fd8fbfc1 1483 return __dquot_alloc_space(inode, number, warn, 1);
1da177e4 1484}
f18df228 1485EXPORT_SYMBOL(dquot_reserve_space);
1da177e4
LT		 1486
1487/*
1488 * This operation can block, but only after everything is updated
1489 */
12095460 1490int dquot_alloc_inode(const struct inode *inode, qsize_t number)
1da177e4
LT		 1491{
1492 int cnt, ret = NO_QUOTA;
1493 char warntype[MAXQUOTAS];
1494
d3be915f
IM		 1495 /* First test before acquiring mutex - solves deadlocks when we
1496 * re-enter the quota code and are already holding the mutex */
1da177e4
LT		 1497 if (IS_NOQUOTA(inode))
1498 return QUOTA_OK;
1499 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
8e893469 1500 warntype[cnt] = QUOTA_NL_NOWARN;
1da177e4
LT		 1501 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1502 if (IS_NOQUOTA(inode)) {
1503 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1504 return QUOTA_OK;
1505 }
1506 spin_lock(&dq_data_lock);
1507 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
dd6f3c6d 1508 if (!inode->i_dquot[cnt])
1da177e4 1509 continue;
268157ba
JK		 1510 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt)
1511 == NO_QUOTA)
1da177e4
LT		 1512 goto warn_put_all;
1513 }
1514
1515 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
dd6f3c6d 1516 if (!inode->i_dquot[cnt])
1da177e4
LT		 1517 continue;
1518 dquot_incr_inodes(inode->i_dquot[cnt], number);
1519 }
1520 ret = QUOTA_OK;
1521warn_put_all:
1522 spin_unlock(&dq_data_lock);
1523 if (ret == QUOTA_OK)
dc52dd3a 1524 mark_all_dquot_dirty(inode->i_dquot);
087ee8d5 1525 flush_warnings(inode->i_dquot, warntype);
1da177e4
LT		 1526 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1527 return ret;
1528}
08d0350c 1529EXPORT_SYMBOL(dquot_alloc_inode);
1da177e4 1530
740d9dcd
MC		 1531int dquot_claim_space(struct inode *inode, qsize_t number)
1532{
1533 int cnt;
1534 int ret = QUOTA_OK;
1535
1536 if (IS_NOQUOTA(inode)) {
fd8fbfc1 1537 inode_claim_rsv_space(inode, number);
740d9dcd
MC		 1538 goto out;
1539 }
1540
1541 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1542 if (IS_NOQUOTA(inode)) {
1543 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
fd8fbfc1 1544 inode_claim_rsv_space(inode, number);
740d9dcd
MC		 1545 goto out;
1546 }
1547
1548 spin_lock(&dq_data_lock);
1549 /* Claim reserved quotas to allocated quotas */
1550 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
dd6f3c6d 1551 if (inode->i_dquot[cnt])
740d9dcd
MC		 1552 dquot_claim_reserved_space(inode->i_dquot[cnt],
1553 number);
1554 }
1555 /* Update inode bytes */
fd8fbfc1 1556 inode_claim_rsv_space(inode, number);
740d9dcd 1557 spin_unlock(&dq_data_lock);
dc52dd3a 1558 mark_all_dquot_dirty(inode->i_dquot);
740d9dcd
MC		 1559 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1560out:
1561 return ret;
1562}
1563EXPORT_SYMBOL(dquot_claim_space);
1564
1da177e4
LT		 1565/*
1566 * This operation can block, but only after everything is updated
1567 */
fd8fbfc1 1568int __dquot_free_space(struct inode *inode, qsize_t number, int reserve)
1da177e4
LT		 1569{
1570 unsigned int cnt;
657d3bfa 1571 char warntype[MAXQUOTAS];
1da177e4 1572
d3be915f
IM		 1573 /* First test before acquiring mutex - solves deadlocks when we
1574 * re-enter the quota code and are already holding the mutex */
1da177e4
LT		 1575 if (IS_NOQUOTA(inode)) {
1576out_sub:
fd8fbfc1 1577 inode_decr_space(inode, number, reserve);
1da177e4
LT		 1578 return QUOTA_OK;
1579 }
657d3bfa 1580
1da177e4
LT		 1581 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1582 /* Now recheck reliably when holding dqptr_sem */
1583 if (IS_NOQUOTA(inode)) {
1584 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1585 goto out_sub;
1586 }
1587 spin_lock(&dq_data_lock);
1588 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
dd6f3c6d 1589 if (!inode->i_dquot[cnt])
1da177e4 1590 continue;
657d3bfa 1591 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
fd8fbfc1
DM		 1592 if (reserve)
1593 dquot_free_reserved_space(inode->i_dquot[cnt], number);
1594 else
1595 dquot_decr_space(inode->i_dquot[cnt], number);
1da177e4 1596 }
fd8fbfc1 1597 inode_decr_space(inode, number, reserve);
1da177e4 1598 spin_unlock(&dq_data_lock);
fd8fbfc1
DM		 1599
1600 if (reserve)
1601 goto out_unlock;
dc52dd3a 1602 mark_all_dquot_dirty(inode->i_dquot);
fd8fbfc1 1603out_unlock:
657d3bfa 1604 flush_warnings(inode->i_dquot, warntype);
1da177e4
LT		 1605 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1606 return QUOTA_OK;
1607}
fd8fbfc1
DM		 1608
1609int dquot_free_space(struct inode *inode, qsize_t number)
1610{
1611 return __dquot_free_space(inode, number, 0);
1612}
08d0350c 1613EXPORT_SYMBOL(dquot_free_space);
1da177e4 1614
fd8fbfc1
DM		 1615/*
1616 * Release reserved quota space
1617 */
1618void dquot_release_reserved_space(struct inode *inode, qsize_t number)
1619{
1620 __dquot_free_space(inode, number, 1);
1621
1622}
1623EXPORT_SYMBOL(dquot_release_reserved_space);
1624
1da177e4
LT		 1625/*
1626 * This operation can block, but only after everything is updated
1627 */
12095460 1628int dquot_free_inode(const struct inode *inode, qsize_t number)
1da177e4
LT		 1629{
1630 unsigned int cnt;
657d3bfa 1631 char warntype[MAXQUOTAS];
1da177e4 1632
d3be915f
IM		 1633 /* First test before acquiring mutex - solves deadlocks when we
1634 * re-enter the quota code and are already holding the mutex */
1da177e4
LT		 1635 if (IS_NOQUOTA(inode))
1636 return QUOTA_OK;
657d3bfa 1637
1da177e4
LT		 1638 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1639 /* Now recheck reliably when holding dqptr_sem */
1640 if (IS_NOQUOTA(inode)) {
1641 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1642 return QUOTA_OK;
1643 }
1644 spin_lock(&dq_data_lock);
1645 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
dd6f3c6d 1646 if (!inode->i_dquot[cnt])
1da177e4 1647 continue;
657d3bfa 1648 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], number);
1da177e4
LT		 1649 dquot_decr_inodes(inode->i_dquot[cnt], number);
1650 }
1651 spin_unlock(&dq_data_lock);
dc52dd3a 1652 mark_all_dquot_dirty(inode->i_dquot);
657d3bfa 1653 flush_warnings(inode->i_dquot, warntype);
1da177e4
LT		 1654 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
1655 return QUOTA_OK;
1656}
08d0350c 1657EXPORT_SYMBOL(dquot_free_inode);
1da177e4
LT		 1658
1659/*
1660 * Transfer the number of inode and blocks from one diskquota to an other.
1661 *
1662 * This operation can block, but only after everything is updated
1663 * A transaction must be started when entering this function.
1664 */
1665int dquot_transfer(struct inode *inode, struct iattr *iattr)
1666{
740d9dcd
MC		 1667 qsize_t space, cur_space;
1668 qsize_t rsv_space = 0;
1da177e4
LT		 1669 struct dquot *transfer_from[MAXQUOTAS];
1670 struct dquot *transfer_to[MAXQUOTAS];
cc33412f
JK		 1671 int cnt, ret = QUOTA_OK;
1672 int chuid = iattr->ia_valid & ATTR_UID && inode->i_uid != iattr->ia_uid,
1673 chgid = iattr->ia_valid & ATTR_GID && inode->i_gid != iattr->ia_gid;
657d3bfa
JK		 1674 char warntype_to[MAXQUOTAS];
1675 char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
1da177e4 1676
d3be915f
IM		 1677 /* First test before acquiring mutex - solves deadlocks when we
1678 * re-enter the quota code and are already holding the mutex */
1da177e4
LT		 1679 if (IS_NOQUOTA(inode))
1680 return QUOTA_OK;
cc33412f 1681 /* Initialize the arrays */
1da177e4 1682 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
dd6f3c6d
JK		 1683 transfer_from[cnt] = NULL;
1684 transfer_to[cnt] = NULL;
657d3bfa 1685 warntype_to[cnt] = QUOTA_NL_NOWARN;
1da177e4 1686 }
268157ba
JK		 1687 if (chuid)
1688 transfer_to[USRQUOTA] = dqget(inode->i_sb, iattr->ia_uid,
1689 USRQUOTA);
1690 if (chgid)
1691 transfer_to[GRPQUOTA] = dqget(inode->i_sb, iattr->ia_gid,
1692 GRPQUOTA);
cc33412f
JK		 1693
1694 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1695 /* Now recheck reliably when holding dqptr_sem */
1696 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */
1697 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1698 goto put_all;
1699 }
1da177e4 1700 spin_lock(&dq_data_lock);
740d9dcd 1701 cur_space = inode_get_bytes(inode);
fd8fbfc1 1702 rsv_space = inode_get_rsv_space(inode);
740d9dcd 1703 space = cur_space + rsv_space;
1da177e4
LT		 1704 /* Build the transfer_from list and check the limits */
1705 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
dd6f3c6d 1706 if (!transfer_to[cnt])
1da177e4
LT		 1707 continue;
1708 transfer_from[cnt] = inode->i_dquot[cnt];
657d3bfa
JK		 1709 if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) ==
1710 NO_QUOTA || check_bdq(transfer_to[cnt], space, 0,
1711 warntype_to + cnt) == NO_QUOTA)
cc33412f 1712 goto over_quota;
1da177e4
LT		 1713 }
1714
1715 /*
1716 * Finally perform the needed transfer from transfer_from to transfer_to
1717 */
1718 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1719 /*
1720 * Skip changes for same uid or gid or for turned off quota-type.
1721 */
dd6f3c6d 1722 if (!transfer_to[cnt])
1da177e4
LT		 1723 continue;
1724
1725 /* Due to IO error we might not have transfer_from[] structure */
1726 if (transfer_from[cnt]) {
657d3bfa
JK		 1727 warntype_from_inodes[cnt] =
1728 info_idq_free(transfer_from[cnt], 1);
1729 warntype_from_space[cnt] =
1730 info_bdq_free(transfer_from[cnt], space);
1da177e4 1731 dquot_decr_inodes(transfer_from[cnt], 1);
740d9dcd
MC		 1732 dquot_decr_space(transfer_from[cnt], cur_space);
1733 dquot_free_reserved_space(transfer_from[cnt],
1734 rsv_space);
1da177e4
LT		 1735 }
1736
1737 dquot_incr_inodes(transfer_to[cnt], 1);
740d9dcd
MC		 1738 dquot_incr_space(transfer_to[cnt], cur_space);
1739 dquot_resv_space(transfer_to[cnt], rsv_space);
1da177e4
LT		 1740
1741 inode->i_dquot[cnt] = transfer_to[cnt];
1742 }
1da177e4 1743 spin_unlock(&dq_data_lock);
cc33412f
JK		 1744 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1745
dc52dd3a
DM		 1746 mark_all_dquot_dirty(transfer_from);
1747 mark_all_dquot_dirty(transfer_to);
1748 /* The reference we got is transferred to the inode */
1749 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1750 transfer_to[cnt] = NULL;
cc33412f 1751warn_put_all:
657d3bfa
JK		 1752 flush_warnings(transfer_to, warntype_to);
1753 flush_warnings(transfer_from, warntype_from_inodes);
1754 flush_warnings(transfer_from, warntype_from_space);
cc33412f 1755put_all:
dc52dd3a
DM		 1756 dqput_all(transfer_from);
1757 dqput_all(transfer_to);
1da177e4 1758 return ret;
cc33412f
JK		 1759over_quota:
1760 spin_unlock(&dq_data_lock);
1761 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
1762 /* Clear dquot pointers we don't want to dqput() */
1763 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
dd6f3c6d 1764 transfer_from[cnt] = NULL;
cc33412f
JK		 1765 ret = NO_QUOTA;
1766 goto warn_put_all;
1da177e4 1767}
08d0350c 1768EXPORT_SYMBOL(dquot_transfer);
1da177e4 1769
b85f4b87
JK		 1770/* Wrapper for transferring ownership of an inode */
1771int vfs_dq_transfer(struct inode *inode, struct iattr *iattr)
1772{
f55abc0f 1773 if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) {
b85f4b87
JK		 1774 vfs_dq_init(inode);
1775 if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA)
1776 return 1;
1777 }
1778 return 0;
1779}
08d0350c 1780EXPORT_SYMBOL(vfs_dq_transfer);
b85f4b87 1781
1da177e4
LT		 1782/*
1783 * Write info of quota file to disk
1784 */
1785int dquot_commit_info(struct super_block *sb, int type)
1786{
1787 int ret;
1788 struct quota_info *dqopt = sb_dqopt(sb);
1789
d3be915f 1790 mutex_lock(&dqopt->dqio_mutex);
1da177e4 1791 ret = dqopt->ops[type]->write_file_info(sb, type);
d3be915f 1792 mutex_unlock(&dqopt->dqio_mutex);
1da177e4
LT		 1793 return ret;
1794}
08d0350c 1795EXPORT_SYMBOL(dquot_commit_info);
1da177e4
LT		 1796
1797/*
1798 * Definitions of diskquota operations.
1799 */
61e225dc 1800const struct dquot_operations dquot_operations = {
1da177e4
LT		 1801 .initialize = dquot_initialize,
1802 .drop = dquot_drop,
1803 .alloc_space = dquot_alloc_space,
1804 .alloc_inode = dquot_alloc_inode,
1805 .free_space = dquot_free_space,
1806 .free_inode = dquot_free_inode,
1807 .transfer = dquot_transfer,
1808 .write_dquot = dquot_commit,
1809 .acquire_dquot = dquot_acquire,
1810 .release_dquot = dquot_release,
1811 .mark_dirty = dquot_mark_dquot_dirty,
74f783af
JK		 1812 .write_info = dquot_commit_info,
1813 .alloc_dquot = dquot_alloc,
1814 .destroy_dquot = dquot_destroy,
1da177e4
LT		 1815};
1816
1da177e4
LT		 1817/*
1818 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
1819 */
f55abc0f 1820int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags)
1da177e4 1821{
0ff5af83 1822 int cnt, ret = 0;
1da177e4
LT		 1823 struct quota_info *dqopt = sb_dqopt(sb);
1824 struct inode *toputinode[MAXQUOTAS];
1da177e4 1825
f55abc0f
JK		 1826 /* Cannot turn off usage accounting without turning off limits, or
1827 * suspend quotas and simultaneously turn quotas off. */
1828 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
1829 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
1830 DQUOT_USAGE_ENABLED)))
1831 return -EINVAL;
1832
1da177e4 1833 /* We need to serialize quota_off() for device */
d3be915f 1834 mutex_lock(&dqopt->dqonoff_mutex);
9377abd0
JK		 1835
1836 /*
1837 * Skip everything if there's nothing to do. We have to do this because
1838 * sometimes we are called when fill_super() failed and calling
1839 * sync_fs() in such cases does no good.
1840 */
f55abc0f 1841 if (!sb_any_quota_loaded(sb)) {
9377abd0
JK		 1842 mutex_unlock(&dqopt->dqonoff_mutex);
1843 return 0;
1844 }
1da177e4
LT		 1845 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
1846 toputinode[cnt] = NULL;
1da177e4
LT		 1847 if (type != -1 && cnt != type)
1848 continue;
f55abc0f 1849 if (!sb_has_quota_loaded(sb, cnt))
0ff5af83 1850 continue;
f55abc0f
JK		 1851
1852 if (flags & DQUOT_SUSPENDED) {
cc33412f 1853 spin_lock(&dq_state_lock);
f55abc0f
JK		 1854 dqopt->flags |=
1855 dquot_state_flag(DQUOT_SUSPENDED, cnt);
cc33412f 1856 spin_unlock(&dq_state_lock);
f55abc0f 1857 } else {
cc33412f 1858 spin_lock(&dq_state_lock);
f55abc0f
JK		 1859 dqopt->flags &= ~dquot_state_flag(flags, cnt);
1860 /* Turning off suspended quotas? */
1861 if (!sb_has_quota_loaded(sb, cnt) &&
1862 sb_has_quota_suspended(sb, cnt)) {
1863 dqopt->flags &= ~dquot_state_flag(
1864 DQUOT_SUSPENDED, cnt);
cc33412f 1865 spin_unlock(&dq_state_lock);
f55abc0f
JK		 1866 iput(dqopt->files[cnt]);
1867 dqopt->files[cnt] = NULL;
1868 continue;
1869 }
cc33412f 1870 spin_unlock(&dq_state_lock);
0ff5af83 1871 }
f55abc0f
JK		 1872
1873 /* We still have to keep quota loaded? */
1874 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
1da177e4 1875 continue;
1da177e4
LT		 1876
1877 /* Note: these are blocking operations */
1878 drop_dquot_ref(sb, cnt);
1879 invalidate_dquots(sb, cnt);
1880 /*
268157ba
JK		 1881 * Now all dquots should be invalidated, all writes done so we
1882 * should be only users of the info. No locks needed.
1da177e4
LT		 1883 */
1884 if (info_dirty(&dqopt->info[cnt]))
1885 sb->dq_op->write_info(sb, cnt);
1886 if (dqopt->ops[cnt]->free_file_info)
1887 dqopt->ops[cnt]->free_file_info(sb, cnt);
1888 put_quota_format(dqopt->info[cnt].dqi_format);
1889
1890 toputinode[cnt] = dqopt->files[cnt];
f55abc0f 1891 if (!sb_has_quota_loaded(sb, cnt))
0ff5af83 1892 dqopt->files[cnt] = NULL;
1da177e4
LT		 1893 dqopt->info[cnt].dqi_flags = 0;
1894 dqopt->info[cnt].dqi_igrace = 0;
1895 dqopt->info[cnt].dqi_bgrace = 0;
1896 dqopt->ops[cnt] = NULL;
1897 }
d3be915f 1898 mutex_unlock(&dqopt->dqonoff_mutex);
ca785ec6
JK		 1899
1900 /* Skip syncing and setting flags if quota files are hidden */
1901 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
1902 goto put_inodes;
1903
1da177e4 1904 /* Sync the superblock so that buffers with quota data are written to
7b7b1ace 1905 * disk (and so userspace sees correct data afterwards). */
1da177e4
LT		 1906 if (sb->s_op->sync_fs)
1907 sb->s_op->sync_fs(sb, 1);
1908 sync_blockdev(sb->s_bdev);
1909 /* Now the quota files are just ordinary files and we can set the
1910 * inode flags back. Moreover we discard the pagecache so that
1911 * userspace sees the writes we did bypassing the pagecache. We
1912 * must also discard the blockdev buffers so that we see the
1913 * changes done by userspace on the next quotaon() */
1914 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1915 if (toputinode[cnt]) {
d3be915f 1916 mutex_lock(&dqopt->dqonoff_mutex);
1da177e4
LT		 1917 /* If quota was reenabled in the meantime, we have
1918 * nothing to do */
f55abc0f 1919 if (!sb_has_quota_loaded(sb, cnt)) {
268157ba
JK		 1920 mutex_lock_nested(&toputinode[cnt]->i_mutex,
1921 I_MUTEX_QUOTA);
1da177e4
LT		 1922 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
1923 S_NOATIME | S_NOQUOTA);
268157ba
JK		 1924 truncate_inode_pages(&toputinode[cnt]->i_data,
1925 0);
1b1dcc1b 1926 mutex_unlock(&toputinode[cnt]->i_mutex);
1da177e4 1927 mark_inode_dirty(toputinode[cnt]);
1da177e4 1928 }
d3be915f 1929 mutex_unlock(&dqopt->dqonoff_mutex);
ca785ec6
JK		 1930 }
1931 if (sb->s_bdev)
1932 invalidate_bdev(sb->s_bdev);
1933put_inodes:
1934 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
1935 if (toputinode[cnt]) {
0ff5af83 1936 /* On remount RO, we keep the inode pointer so that we
f55abc0f
JK		 1937 * can reenable quota on the subsequent remount RW. We
1938 * have to check 'flags' variable and not use sb_has_
1939 * function because another quotaon / quotaoff could
1940 * change global state before we got here. We refuse
1941 * to suspend quotas when there is pending delete on
1942 * the quota file... */
1943 if (!(flags & DQUOT_SUSPENDED))
0ff5af83
JK		 1944 iput(toputinode[cnt]);
1945 else if (!toputinode[cnt]->i_nlink)
1946 ret = -EBUSY;
1da177e4 1947 }
0ff5af83 1948 return ret;
1da177e4 1949}
08d0350c 1950EXPORT_SYMBOL(vfs_quota_disable);
1da177e4 1951
f55abc0f
JK		 1952int vfs_quota_off(struct super_block *sb, int type, int remount)
1953{
1954 return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED :
1955 (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED));
1956}
08d0350c 1957EXPORT_SYMBOL(vfs_quota_off);
1da177e4
LT		 1958/*
1959 * Turn quotas on on a device
1960 */
1961
f55abc0f
JK		 1962/*
1963 * Helper function to turn quotas on when we already have the inode of
1964 * quota file and no quota information is loaded.
1965 */
1966static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
1967 unsigned int flags)
1da177e4
LT		 1968{
1969 struct quota_format_type *fmt = find_quota_format(format_id);
1970 struct super_block *sb = inode->i_sb;
1971 struct quota_info *dqopt = sb_dqopt(sb);
1972 int error;
1973 int oldflags = -1;
1974
1975 if (!fmt)
1976 return -ESRCH;
1977 if (!S_ISREG(inode->i_mode)) {
1978 error = -EACCES;
1979 goto out_fmt;
1980 }
1981 if (IS_RDONLY(inode)) {
1982 error = -EROFS;
1983 goto out_fmt;
1984 }
1985 if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
1986 error = -EINVAL;
1987 goto out_fmt;
1988 }
f55abc0f
JK		 1989 /* Usage always has to be set... */
1990 if (!(flags & DQUOT_USAGE_ENABLED)) {
1991 error = -EINVAL;
1992 goto out_fmt;
1993 }
1da177e4 1994
ca785ec6
JK		 1995 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
1996 /* As we bypass the pagecache we must now flush the inode so
1997 * that we see all the changes from userspace... */
1998 write_inode_now(inode, 1);
1999 /* And now flush the block cache so that kernel sees the
2000 * changes */
2001 invalidate_bdev(sb->s_bdev);
2002 }
d3be915f 2003 mutex_lock(&dqopt->dqonoff_mutex);
f55abc0f 2004 if (sb_has_quota_loaded(sb, type)) {
1da177e4
LT		 2005 error = -EBUSY;
2006 goto out_lock;
2007 }
ca785ec6
JK		 2008
2009 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2010 /* We don't want quota and atime on quota files (deadlocks
2011 * possible) Also nobody should write to the file - we use
2012 * special IO operations which ignore the immutable bit. */
2013 down_write(&dqopt->dqptr_sem);
dee86565 2014 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
268157ba
JK		 2015 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
2016 S_NOQUOTA);
ca785ec6 2017 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
dee86565 2018 mutex_unlock(&inode->i_mutex);
ca785ec6
JK		 2019 up_write(&dqopt->dqptr_sem);
2020 sb->dq_op->drop(inode);
2021 }
1da177e4
LT		 2022
2023 error = -EIO;
2024 dqopt->files[type] = igrab(inode);
2025 if (!dqopt->files[type])
2026 goto out_lock;
2027 error = -EINVAL;
2028 if (!fmt->qf_ops->check_quota_file(sb, type))
2029 goto out_file_init;
2030
2031 dqopt->ops[type] = fmt->qf_ops;
2032 dqopt->info[type].dqi_format = fmt;
0ff5af83 2033 dqopt->info[type].dqi_fmt_id = format_id;
1da177e4 2034 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
d3be915f 2035 mutex_lock(&dqopt->dqio_mutex);
268157ba
JK		 2036 error = dqopt->ops[type]->read_file_info(sb, type);
2037 if (error < 0) {
d3be915f 2038 mutex_unlock(&dqopt->dqio_mutex);
1da177e4
LT		 2039 goto out_file_init;
2040 }
d3be915f 2041 mutex_unlock(&dqopt->dqio_mutex);
cc33412f 2042 spin_lock(&dq_state_lock);
f55abc0f 2043 dqopt->flags |= dquot_state_flag(flags, type);
cc33412f 2044 spin_unlock(&dq_state_lock);
1da177e4
LT		 2045
2046 add_dquot_ref(sb, type);
d3be915f 2047 mutex_unlock(&dqopt->dqonoff_mutex);
1da177e4
LT		 2048
2049 return 0;
2050
2051out_file_init:
2052 dqopt->files[type] = NULL;
2053 iput(inode);
2054out_lock:
1da177e4
LT		 2055 if (oldflags != -1) {
2056 down_write(&dqopt->dqptr_sem);
dee86565 2057 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1da177e4
LT		 2058 /* Set the flags back (in the case of accidental quotaon()
2059 * on a wrong file we don't want to mess up the flags) */
2060 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
2061 inode->i_flags |= oldflags;
dee86565 2062 mutex_unlock(&inode->i_mutex);
1da177e4
LT		 2063 up_write(&dqopt->dqptr_sem);
2064 }
d01730d7 2065 mutex_unlock(&dqopt->dqonoff_mutex);
1da177e4
LT		 2066out_fmt:
2067 put_quota_format(fmt);
2068
2069 return error;
2070}
2071
0ff5af83
JK		 2072/* Reenable quotas on remount RW */
2073static int vfs_quota_on_remount(struct super_block *sb, int type)
2074{
2075 struct quota_info *dqopt = sb_dqopt(sb);
2076 struct inode *inode;
2077 int ret;
f55abc0f 2078 unsigned int flags;
0ff5af83
JK		 2079
2080 mutex_lock(&dqopt->dqonoff_mutex);
2081 if (!sb_has_quota_suspended(sb, type)) {
2082 mutex_unlock(&dqopt->dqonoff_mutex);
2083 return 0;
2084 }
0ff5af83
JK		 2085 inode = dqopt->files[type];
2086 dqopt->files[type] = NULL;
cc33412f 2087 spin_lock(&dq_state_lock);
f55abc0f
JK		 2088 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
2089 DQUOT_LIMITS_ENABLED, type);
2090 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type);
cc33412f 2091 spin_unlock(&dq_state_lock);
0ff5af83
JK		 2092 mutex_unlock(&dqopt->dqonoff_mutex);
2093
f55abc0f
JK		 2094 flags = dquot_generic_flag(flags, type);
2095 ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id,
2096 flags);
0ff5af83
JK		 2097 iput(inode);
2098
2099 return ret;
2100}
2101
77e69dac
AV		 2102int vfs_quota_on_path(struct super_block *sb, int type, int format_id,
2103 struct path *path)
2104{
2105 int error = security_quota_on(path->dentry);
2106 if (error)
2107 return error;
2108 /* Quota file not on the same filesystem? */
2109 if (path->mnt->mnt_sb != sb)
2110 error = -EXDEV;
2111 else
f55abc0f
JK		 2112 error = vfs_load_quota_inode(path->dentry->d_inode, type,
2113 format_id, DQUOT_USAGE_ENABLED |
2114 DQUOT_LIMITS_ENABLED);
77e69dac
AV		 2115 return error;
2116}
08d0350c 2117EXPORT_SYMBOL(vfs_quota_on_path);
77e69dac 2118
8264613d 2119int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name,
0ff5af83 2120 int remount)
1da177e4 2121{
8264613d 2122 struct path path;
1da177e4
LT		 2123 int error;
2124
0ff5af83
JK		 2125 if (remount)
2126 return vfs_quota_on_remount(sb, type);
2127
8264613d 2128 error = kern_path(name, LOOKUP_FOLLOW, &path);
77e69dac 2129 if (!error) {
8264613d
AV		 2130 error = vfs_quota_on_path(sb, type, format_id, &path);
2131 path_put(&path);
77e69dac 2132 }
1da177e4
LT		 2133 return error;
2134}
08d0350c 2135EXPORT_SYMBOL(vfs_quota_on);
1da177e4 2136
f55abc0f
JK		 2137/*
2138 * More powerful function for turning on quotas allowing setting
2139 * of individual quota flags
2140 */
2141int vfs_quota_enable(struct inode *inode, int type, int format_id,
2142 unsigned int flags)
2143{
2144 int ret = 0;
2145 struct super_block *sb = inode->i_sb;
2146 struct quota_info *dqopt = sb_dqopt(sb);
2147
2148 /* Just unsuspend quotas? */
2149 if (flags & DQUOT_SUSPENDED)
2150 return vfs_quota_on_remount(sb, type);
2151 if (!flags)
2152 return 0;
2153 /* Just updating flags needed? */
2154 if (sb_has_quota_loaded(sb, type)) {
2155 mutex_lock(&dqopt->dqonoff_mutex);
2156 /* Now do a reliable test... */
2157 if (!sb_has_quota_loaded(sb, type)) {
2158 mutex_unlock(&dqopt->dqonoff_mutex);
2159 goto load_quota;
2160 }
2161 if (flags & DQUOT_USAGE_ENABLED &&
2162 sb_has_quota_usage_enabled(sb, type)) {
2163 ret = -EBUSY;
2164 goto out_lock;
2165 }
2166 if (flags & DQUOT_LIMITS_ENABLED &&
2167 sb_has_quota_limits_enabled(sb, type)) {
2168 ret = -EBUSY;
2169 goto out_lock;
2170 }
cc33412f 2171 spin_lock(&dq_state_lock);
f55abc0f 2172 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
cc33412f 2173 spin_unlock(&dq_state_lock);
f55abc0f
JK		 2174out_lock:
2175 mutex_unlock(&dqopt->dqonoff_mutex);
2176 return ret;
2177 }
2178
2179load_quota:
2180 return vfs_load_quota_inode(inode, type, format_id, flags);
2181}
08d0350c 2182EXPORT_SYMBOL(vfs_quota_enable);
f55abc0f 2183
1da177e4
LT		 2184/*
2185 * This function is used when filesystem needs to initialize quotas
2186 * during mount time.
2187 */
84de856e
CH		 2188int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
2189 int format_id, int type)
1da177e4 2190{
84de856e 2191 struct dentry *dentry;
1da177e4
LT		 2192 int error;
2193
c56818d7 2194 mutex_lock(&sb->s_root->d_inode->i_mutex);
2fa389c5 2195 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
c56818d7 2196 mutex_unlock(&sb->s_root->d_inode->i_mutex);
84de856e
CH		 2197 if (IS_ERR(dentry))
2198 return PTR_ERR(dentry);
2199
154f484b
JK		 2200 if (!dentry->d_inode) {
2201 error = -ENOENT;
2202 goto out;
2203 }
2204
1da177e4 2205 error = security_quota_on(dentry);
84de856e 2206 if (!error)
f55abc0f
JK		 2207 error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
2208 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
84de856e 2209
154f484b 2210out:
84de856e
CH		 2211 dput(dentry);
2212 return error;
1da177e4 2213}
08d0350c 2214EXPORT_SYMBOL(vfs_quota_on_mount);
1da177e4 2215
b85f4b87
JK		 2216/* Wrapper to turn on quotas when remounting rw */
2217int vfs_dq_quota_on_remount(struct super_block *sb)
2218{
2219 int cnt;
2220 int ret = 0, err;
2221
2222 if (!sb->s_qcop || !sb->s_qcop->quota_on)
2223 return -ENOSYS;
2224 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2225 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1);
2226 if (err < 0 && !ret)
2227 ret = err;
2228 }
2229 return ret;
2230}
08d0350c 2231EXPORT_SYMBOL(vfs_dq_quota_on_remount);
b85f4b87 2232
12095460
JK		 2233static inline qsize_t qbtos(qsize_t blocks)
2234{
2235 return blocks << QIF_DQBLKSIZE_BITS;
2236}
2237
2238static inline qsize_t stoqb(qsize_t space)
2239{
2240 return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
2241}
2242
1da177e4
LT		 2243/* Generic routine for getting common part of quota structure */
2244static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
2245{
2246 struct mem_dqblk *dm = &dquot->dq_dqb;
2247
2248 spin_lock(&dq_data_lock);
12095460
JK		 2249 di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit);
2250 di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit);
f18df228 2251 di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace;
1da177e4
LT		 2252 di->dqb_ihardlimit = dm->dqb_ihardlimit;
2253 di->dqb_isoftlimit = dm->dqb_isoftlimit;
2254 di->dqb_curinodes = dm->dqb_curinodes;
2255 di->dqb_btime = dm->dqb_btime;
2256 di->dqb_itime = dm->dqb_itime;
2257 di->dqb_valid = QIF_ALL;
2258 spin_unlock(&dq_data_lock);
2259}
2260
268157ba
JK		 2261int vfs_get_dqblk(struct super_block *sb, int type, qid_t id,
2262 struct if_dqblk *di)
1da177e4
LT		 2263{
2264 struct dquot *dquot;
2265
cc33412f 2266 dquot = dqget(sb, id, type);
dd6f3c6d 2267 if (!dquot)
1da177e4 2268 return -ESRCH;
1da177e4
LT		 2269 do_get_dqblk(dquot, di);
2270 dqput(dquot);
cc33412f 2271
1da177e4
LT		 2272 return 0;
2273}
08d0350c 2274EXPORT_SYMBOL(vfs_get_dqblk);
1da177e4
LT		 2275
2276/* Generic routine for setting common part of quota structure */
338bf9af 2277static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
1da177e4
LT		 2278{
2279 struct mem_dqblk *dm = &dquot->dq_dqb;
2280 int check_blim = 0, check_ilim = 0;
338bf9af
AP		 2281 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
2282
2283 if ((di->dqb_valid & QIF_BLIMITS &&
2284 (di->dqb_bhardlimit > dqi->dqi_maxblimit ||
2285 di->dqb_bsoftlimit > dqi->dqi_maxblimit)) ||
2286 (di->dqb_valid & QIF_ILIMITS &&
2287 (di->dqb_ihardlimit > dqi->dqi_maxilimit ||
2288 di->dqb_isoftlimit > dqi->dqi_maxilimit)))
2289 return -ERANGE;
1da177e4
LT		 2290
2291 spin_lock(&dq_data_lock);
2292 if (di->dqb_valid & QIF_SPACE) {
f18df228 2293 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace;
1da177e4 2294 check_blim = 1;
4d59bce4 2295 __set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
1da177e4
LT		 2296 }
2297 if (di->dqb_valid & QIF_BLIMITS) {
12095460
JK		 2298 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit);
2299 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit);
1da177e4 2300 check_blim = 1;
4d59bce4 2301 __set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
1da177e4
LT		 2302 }
2303 if (di->dqb_valid & QIF_INODES) {
2304 dm->dqb_curinodes = di->dqb_curinodes;
2305 check_ilim = 1;
4d59bce4 2306 __set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
1da177e4
LT		 2307 }
2308 if (di->dqb_valid & QIF_ILIMITS) {
2309 dm->dqb_isoftlimit = di->dqb_isoftlimit;
2310 dm->dqb_ihardlimit = di->dqb_ihardlimit;
2311 check_ilim = 1;
4d59bce4 2312 __set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
1da177e4 2313 }
4d59bce4 2314 if (di->dqb_valid & QIF_BTIME) {
1da177e4 2315 dm->dqb_btime = di->dqb_btime;
e04a88a9 2316 check_blim = 1;
4d59bce4
JK		 2317 __set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
2318 }
2319 if (di->dqb_valid & QIF_ITIME) {
1da177e4 2320 dm->dqb_itime = di->dqb_itime;
e04a88a9 2321 check_ilim = 1;
4d59bce4
JK		 2322 __set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
2323 }
1da177e4
LT		 2324
2325 if (check_blim) {
268157ba
JK		 2326 if (!dm->dqb_bsoftlimit ||
2327 dm->dqb_curspace < dm->dqb_bsoftlimit) {
1da177e4
LT		 2328 dm->dqb_btime = 0;
2329 clear_bit(DQ_BLKS_B, &dquot->dq_flags);
268157ba
JK		 2330 } else if (!(di->dqb_valid & QIF_BTIME))
2331 /* Set grace only if user hasn't provided his own... */
338bf9af 2332 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
1da177e4
LT		 2333 }
2334 if (check_ilim) {
268157ba
JK		 2335 if (!dm->dqb_isoftlimit ||
2336 dm->dqb_curinodes < dm->dqb_isoftlimit) {
1da177e4
LT		 2337 dm->dqb_itime = 0;
2338 clear_bit(DQ_INODES_B, &dquot->dq_flags);
268157ba
JK		 2339 } else if (!(di->dqb_valid & QIF_ITIME))
2340 /* Set grace only if user hasn't provided his own... */
338bf9af 2341 dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
1da177e4 2342 }
268157ba
JK		 2343 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
2344 dm->dqb_isoftlimit)
1da177e4
LT		 2345 clear_bit(DQ_FAKE_B, &dquot->dq_flags);
2346 else
2347 set_bit(DQ_FAKE_B, &dquot->dq_flags);
2348 spin_unlock(&dq_data_lock);
2349 mark_dquot_dirty(dquot);
338bf9af
AP		 2350
2351 return 0;
1da177e4
LT		 2352}
2353
268157ba
JK		 2354int vfs_set_dqblk(struct super_block *sb, int type, qid_t id,
2355 struct if_dqblk *di)
1da177e4
LT		 2356{
2357 struct dquot *dquot;
338bf9af 2358 int rc;
1da177e4 2359
f55abc0f
JK		 2360 dquot = dqget(sb, id, type);
2361 if (!dquot) {
2362 rc = -ESRCH;
2363 goto out;
1da177e4 2364 }
338bf9af 2365 rc = do_set_dqblk(dquot, di);
1da177e4 2366 dqput(dquot);
f55abc0f 2367out:
338bf9af 2368 return rc;
1da177e4 2369}
08d0350c 2370EXPORT_SYMBOL(vfs_set_dqblk);
1da177e4
LT		 2371
2372/* Generic routine for getting common part of quota file information */
2373int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2374{
2375 struct mem_dqinfo *mi;
2376
d3be915f 2377 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
f55abc0f 2378 if (!sb_has_quota_active(sb, type)) {
d3be915f 2379 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1da177e4
LT		 2380 return -ESRCH;
2381 }
2382 mi = sb_dqopt(sb)->info + type;
2383 spin_lock(&dq_data_lock);
2384 ii->dqi_bgrace = mi->dqi_bgrace;
2385 ii->dqi_igrace = mi->dqi_igrace;
2386 ii->dqi_flags = mi->dqi_flags & DQF_MASK;
2387 ii->dqi_valid = IIF_ALL;
2388 spin_unlock(&dq_data_lock);
d3be915f 2389 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
1da177e4
LT		 2390 return 0;
2391}
08d0350c 2392EXPORT_SYMBOL(vfs_get_dqinfo);
1da177e4
LT		 2393
2394/* Generic routine for setting common part of quota file information */
2395int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
2396{
2397 struct mem_dqinfo *mi;
f55abc0f 2398 int err = 0;
1da177e4 2399
d3be915f 2400 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
f55abc0f
JK		 2401 if (!sb_has_quota_active(sb, type)) {
2402 err = -ESRCH;
2403 goto out;
1da177e4
LT		 2404 }
2405 mi = sb_dqopt(sb)->info + type;
2406 spin_lock(&dq_data_lock);
2407 if (ii->dqi_valid & IIF_BGRACE)
2408 mi->dqi_bgrace = ii->dqi_bgrace;
2409 if (ii->dqi_valid & IIF_IGRACE)
2410 mi->dqi_igrace = ii->dqi_igrace;
2411 if (ii->dqi_valid & IIF_FLAGS)
268157ba
JK		 2412 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) |
2413 (ii->dqi_flags & DQF_MASK);
1da177e4
LT		 2414 spin_unlock(&dq_data_lock);
2415 mark_info_dirty(sb, type);
2416 /* Force write to disk */
2417 sb->dq_op->write_info(sb, type);
f55abc0f 2418out:
d3be915f 2419 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
f55abc0f 2420 return err;
1da177e4 2421}
08d0350c 2422EXPORT_SYMBOL(vfs_set_dqinfo);
1da177e4 2423
0d54b217 2424const struct quotactl_ops vfs_quotactl_ops = {
1da177e4
LT		 2425 .quota_on = vfs_quota_on,
2426 .quota_off = vfs_quota_off,
2427 .quota_sync = vfs_quota_sync,
2428 .get_info = vfs_get_dqinfo,
2429 .set_info = vfs_set_dqinfo,
2430 .get_dqblk = vfs_get_dqblk,
2431 .set_dqblk = vfs_set_dqblk
2432};
2433
2434static ctl_table fs_dqstats_table[] = {
2435 {
1da177e4
LT		 2436 .procname = "lookups",
2437 .data = &dqstats.lookups,
2438 .maxlen = sizeof(int),
2439 .mode = 0444,
6d456111 2440 .proc_handler = proc_dointvec,
1da177e4
LT		 2441 },
2442 {
1da177e4
LT		 2443 .procname = "drops",
2444 .data = &dqstats.drops,
2445 .maxlen = sizeof(int),
2446 .mode = 0444,
6d456111 2447 .proc_handler = proc_dointvec,
1da177e4
LT		 2448 },
2449 {
1da177e4
LT		 2450 .procname = "reads",
2451 .data = &dqstats.reads,
2452 .maxlen = sizeof(int),
2453 .mode = 0444,
6d456111 2454 .proc_handler = proc_dointvec,
1da177e4
LT		 2455 },
2456 {
1da177e4
LT		 2457 .procname = "writes",
2458 .data = &dqstats.writes,
2459 .maxlen = sizeof(int),
2460 .mode = 0444,
6d456111 2461 .proc_handler = proc_dointvec,
1da177e4
LT		 2462 },
2463 {
1da177e4
LT		 2464 .procname = "cache_hits",
2465 .data = &dqstats.cache_hits,
2466 .maxlen = sizeof(int),
2467 .mode = 0444,
6d456111 2468 .proc_handler = proc_dointvec,
1da177e4
LT		 2469 },
2470 {
1da177e4
LT		 2471 .procname = "allocated_dquots",
2472 .data = &dqstats.allocated_dquots,
2473 .maxlen = sizeof(int),
2474 .mode = 0444,
6d456111 2475 .proc_handler = proc_dointvec,
1da177e4
LT		 2476 },
2477 {
1da177e4
LT		 2478 .procname = "free_dquots",
2479 .data = &dqstats.free_dquots,
2480 .maxlen = sizeof(int),
2481 .mode = 0444,
6d456111 2482 .proc_handler = proc_dointvec,
1da177e4
LT		 2483 },
2484 {
1da177e4
LT		 2485 .procname = "syncs",
2486 .data = &dqstats.syncs,
2487 .maxlen = sizeof(int),
2488 .mode = 0444,
6d456111 2489 .proc_handler = proc_dointvec,
1da177e4 2490 },
8e893469 2491#ifdef CONFIG_PRINT_QUOTA_WARNING
1da177e4 2492 {
1da177e4
LT		 2493 .procname = "warnings",
2494 .data = &flag_print_warnings,
2495 .maxlen = sizeof(int),
2496 .mode = 0644,
6d456111 2497 .proc_handler = proc_dointvec,
1da177e4 2498 },
8e893469 2499#endif
ab09203e 2500 { },
1da177e4
LT		 2501};
2502
2503static ctl_table fs_table[] = {
2504 {
1da177e4
LT		 2505 .procname = "quota",
2506 .mode = 0555,
2507 .child = fs_dqstats_table,
2508 },
ab09203e 2509 { },
1da177e4
LT		 2510};
2511
2512static ctl_table sys_table[] = {
2513 {
1da177e4
LT		 2514 .procname = "fs",
2515 .mode = 0555,
2516 .child = fs_table,
2517 },
ab09203e 2518 { },
1da177e4
LT		 2519};
2520
2521static int __init dquot_init(void)
2522{
2523 int i;
2524 unsigned long nr_hash, order;
2525
2526 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
2527
0b4d4147 2528 register_sysctl_table(sys_table);
1da177e4 2529
20c2df83 2530 dquot_cachep = kmem_cache_create("dquot",
1da177e4 2531 sizeof(struct dquot), sizeof(unsigned long) * 4,
fffb60f9
PJ		 2532 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
2533 SLAB_MEM_SPREAD|SLAB_PANIC),
20c2df83 2534 NULL);
1da177e4
LT		 2535
2536 order = 0;
2537 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
2538 if (!dquot_hash)
2539 panic("Cannot create dquot hash table");
2540
2541 /* Find power-of-two hlist_heads which can fit into allocation */
2542 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2543 dq_hash_bits = 0;
2544 do {
2545 dq_hash_bits++;
2546 } while (nr_hash >> dq_hash_bits);
2547 dq_hash_bits--;
2548
2549 nr_hash = 1UL << dq_hash_bits;
2550 dq_hash_mask = nr_hash - 1;
2551 for (i = 0; i < nr_hash; i++)
2552 INIT_HLIST_HEAD(dquot_hash + i);
2553
2554 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
2555 nr_hash, order, (PAGE_SIZE << order));
2556
8e1f936b 2557 register_shrinker(&dqcache_shrinker);
1da177e4
LT		 2558
2559 return 0;
2560}
2561module_init(dquot_init);
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