blob: 4a8c94f05f76b29cce8c0b811e09a33a6ea3a2da [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Quota code necessary even when VFS quota support is not compiled
3 * into the kernel. The interesting stuff is over in dquot.c, here
4 * we have symbols for initial quotactl(2) handling, the sysctl(2)
5 * variables, etc - things needed even when quota support disabled.
6 */
7
8#include <linux/fs.h>
9#include <linux/namei.h>
10#include <linux/slab.h>
11#include <asm/current.h>
12#include <asm/uaccess.h>
Vasily Tarasovb7163952007-07-15 23:41:12 -070013#include <linux/compat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/security.h>
16#include <linux/syscalls.h>
17#include <linux/buffer_head.h>
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080018#include <linux/capability.h>
Adrian Bunkbe586ba2005-11-07 00:59:35 -080019#include <linux/quotaops.h>
Vasily Tarasovb7163952007-07-15 23:41:12 -070020#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
22/* Check validity of generic quotactl commands */
23static int generic_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id)
24{
25 if (type >= MAXQUOTAS)
26 return -EINVAL;
27 if (!sb && cmd != Q_SYNC)
28 return -ENODEV;
29 /* Is operation supported? */
30 if (sb && !sb->s_qcop)
31 return -ENOSYS;
32
33 switch (cmd) {
34 case Q_GETFMT:
35 break;
36 case Q_QUOTAON:
37 if (!sb->s_qcop->quota_on)
38 return -ENOSYS;
39 break;
40 case Q_QUOTAOFF:
41 if (!sb->s_qcop->quota_off)
42 return -ENOSYS;
43 break;
44 case Q_SETINFO:
45 if (!sb->s_qcop->set_info)
46 return -ENOSYS;
47 break;
48 case Q_GETINFO:
49 if (!sb->s_qcop->get_info)
50 return -ENOSYS;
51 break;
52 case Q_SETQUOTA:
53 if (!sb->s_qcop->set_dqblk)
54 return -ENOSYS;
55 break;
56 case Q_GETQUOTA:
57 if (!sb->s_qcop->get_dqblk)
58 return -ENOSYS;
59 break;
60 case Q_SYNC:
61 if (sb && !sb->s_qcop->quota_sync)
62 return -ENOSYS;
63 break;
64 default:
65 return -EINVAL;
66 }
67
68 /* Is quota turned on for commands which need it? */
69 switch (cmd) {
70 case Q_GETFMT:
71 case Q_GETINFO:
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 case Q_SETINFO:
73 case Q_SETQUOTA:
74 case Q_GETQUOTA:
75 /* This is just informative test so we are satisfied without a lock */
Jan Karaf55abc02008-08-20 17:50:32 +020076 if (!sb_has_quota_active(sb, type))
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 return -ESRCH;
78 }
79
80 /* Check privileges */
81 if (cmd == Q_GETQUOTA) {
David Howellsda9592e2008-11-14 10:39:05 +110082 if (((type == USRQUOTA && current_euid() != id) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 (type == GRPQUOTA && !in_egroup_p(id))) &&
84 !capable(CAP_SYS_ADMIN))
85 return -EPERM;
86 }
87 else if (cmd != Q_GETFMT && cmd != Q_SYNC && cmd != Q_GETINFO)
88 if (!capable(CAP_SYS_ADMIN))
89 return -EPERM;
90
91 return 0;
92}
93
94/* Check validity of XFS Quota Manager commands */
95static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id)
96{
97 if (type >= XQM_MAXQUOTAS)
98 return -EINVAL;
99 if (!sb)
100 return -ENODEV;
101 if (!sb->s_qcop)
102 return -ENOSYS;
103
104 switch (cmd) {
105 case Q_XQUOTAON:
106 case Q_XQUOTAOFF:
107 case Q_XQUOTARM:
108 if (!sb->s_qcop->set_xstate)
109 return -ENOSYS;
110 break;
111 case Q_XGETQSTAT:
112 if (!sb->s_qcop->get_xstate)
113 return -ENOSYS;
114 break;
115 case Q_XSETQLIM:
116 if (!sb->s_qcop->set_xquota)
117 return -ENOSYS;
118 break;
119 case Q_XGETQUOTA:
120 if (!sb->s_qcop->get_xquota)
121 return -ENOSYS;
122 break;
Nathan Scottde69e5f2005-11-03 13:53:34 +1100123 case Q_XQUOTASYNC:
124 if (!sb->s_qcop->quota_sync)
125 return -ENOSYS;
126 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 default:
128 return -EINVAL;
129 }
130
131 /* Check privileges */
132 if (cmd == Q_XGETQUOTA) {
David Howellsda9592e2008-11-14 10:39:05 +1100133 if (((type == XQM_USRQUOTA && current_euid() != id) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 (type == XQM_GRPQUOTA && !in_egroup_p(id))) &&
135 !capable(CAP_SYS_ADMIN))
136 return -EPERM;
Nathan Scottde69e5f2005-11-03 13:53:34 +1100137 } else if (cmd != Q_XGETQSTAT && cmd != Q_XQUOTASYNC) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 if (!capable(CAP_SYS_ADMIN))
139 return -EPERM;
140 }
141
142 return 0;
143}
144
145static int check_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id)
146{
147 int error;
148
149 if (XQM_COMMAND(cmd))
150 error = xqm_quotactl_valid(sb, type, cmd, id);
151 else
152 error = generic_quotactl_valid(sb, type, cmd, id);
153 if (!error)
154 error = security_quotactl(cmd, type, id, sb);
155 return error;
156}
157
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158static void quota_sync_sb(struct super_block *sb, int type)
159{
160 int cnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162 sb->s_qcop->quota_sync(sb, type);
Jan Karaca785ec2008-09-30 17:53:37 +0200163
164 if (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)
165 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 /* This is not very clever (and fast) but currently I don't know about
167 * any other simple way of getting quota data to disk and we must get
168 * them there for userspace to be visible... */
169 if (sb->s_op->sync_fs)
170 sb->s_op->sync_fs(sb, 1);
171 sync_blockdev(sb->s_bdev);
172
Jan Kara79254092007-05-16 22:11:19 -0700173 /*
174 * Now when everything is written we can discard the pagecache so
175 * that userspace sees the changes.
176 */
Ingo Molnard3be9152006-03-23 03:00:29 -0800177 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 if (type != -1 && cnt != type)
180 continue;
Jan Karaf55abc02008-08-20 17:50:32 +0200181 if (!sb_has_quota_active(sb, cnt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 continue;
Jan Kara79254092007-05-16 22:11:19 -0700183 mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, I_MUTEX_QUOTA);
184 truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
185 mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 }
Ingo Molnard3be9152006-03-23 03:00:29 -0800187 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188}
189
190void sync_dquots(struct super_block *sb, int type)
191{
Jan Kara02a55ca2008-07-25 01:46:50 -0700192 int cnt;
Kirill Korotaev618f0632005-06-23 00:09:54 -0700193
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 if (sb) {
195 if (sb->s_qcop->quota_sync)
196 quota_sync_sb(sb, type);
Kirill Korotaev618f0632005-06-23 00:09:54 -0700197 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 }
Kirill Korotaev618f0632005-06-23 00:09:54 -0700199
200 spin_lock(&sb_lock);
201restart:
202 list_for_each_entry(sb, &super_blocks, s_list) {
203 /* This test just improves performance so it needn't be reliable... */
Jan Kara02a55ca2008-07-25 01:46:50 -0700204 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
205 if (type != -1 && type != cnt)
206 continue;
Jan Karaf55abc02008-08-20 17:50:32 +0200207 if (!sb_has_quota_active(sb, cnt))
Jan Kara02a55ca2008-07-25 01:46:50 -0700208 continue;
209 if (!info_dirty(&sb_dqopt(sb)->info[cnt]) &&
210 list_empty(&sb_dqopt(sb)->info[cnt].dqi_dirty_list))
211 continue;
212 break;
213 }
214 if (cnt == MAXQUOTAS)
Kirill Korotaev618f0632005-06-23 00:09:54 -0700215 continue;
216 sb->s_count++;
217 spin_unlock(&sb_lock);
218 down_read(&sb->s_umount);
219 if (sb->s_root && sb->s_qcop->quota_sync)
220 quota_sync_sb(sb, type);
221 up_read(&sb->s_umount);
222 spin_lock(&sb_lock);
223 if (__put_super_and_need_restart(sb))
224 goto restart;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 }
Kirill Korotaev618f0632005-06-23 00:09:54 -0700226 spin_unlock(&sb_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227}
228
229/* Copy parameters and call proper function */
230static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, void __user *addr)
231{
232 int ret;
233
234 switch (cmd) {
235 case Q_QUOTAON: {
236 char *pathname;
237
238 if (IS_ERR(pathname = getname(addr)))
239 return PTR_ERR(pathname);
Jan Kara0ff5af82008-04-28 02:14:33 -0700240 ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 putname(pathname);
242 return ret;
243 }
244 case Q_QUOTAOFF:
Jan Kara0ff5af82008-04-28 02:14:33 -0700245 return sb->s_qcop->quota_off(sb, type, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247 case Q_GETFMT: {
248 __u32 fmt;
249
250 down_read(&sb_dqopt(sb)->dqptr_sem);
Jan Karaf55abc02008-08-20 17:50:32 +0200251 if (!sb_has_quota_active(sb, type)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 up_read(&sb_dqopt(sb)->dqptr_sem);
253 return -ESRCH;
254 }
255 fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
256 up_read(&sb_dqopt(sb)->dqptr_sem);
257 if (copy_to_user(addr, &fmt, sizeof(fmt)))
258 return -EFAULT;
259 return 0;
260 }
261 case Q_GETINFO: {
262 struct if_dqinfo info;
263
264 if ((ret = sb->s_qcop->get_info(sb, type, &info)))
265 return ret;
266 if (copy_to_user(addr, &info, sizeof(info)))
267 return -EFAULT;
268 return 0;
269 }
270 case Q_SETINFO: {
271 struct if_dqinfo info;
272
273 if (copy_from_user(&info, addr, sizeof(info)))
274 return -EFAULT;
275 return sb->s_qcop->set_info(sb, type, &info);
276 }
277 case Q_GETQUOTA: {
278 struct if_dqblk idq;
279
280 if ((ret = sb->s_qcop->get_dqblk(sb, type, id, &idq)))
281 return ret;
282 if (copy_to_user(addr, &idq, sizeof(idq)))
283 return -EFAULT;
284 return 0;
285 }
286 case Q_SETQUOTA: {
287 struct if_dqblk idq;
288
289 if (copy_from_user(&idq, addr, sizeof(idq)))
290 return -EFAULT;
291 return sb->s_qcop->set_dqblk(sb, type, id, &idq);
292 }
293 case Q_SYNC:
294 sync_dquots(sb, type);
295 return 0;
296
297 case Q_XQUOTAON:
298 case Q_XQUOTAOFF:
299 case Q_XQUOTARM: {
300 __u32 flags;
301
302 if (copy_from_user(&flags, addr, sizeof(flags)))
303 return -EFAULT;
304 return sb->s_qcop->set_xstate(sb, flags, cmd);
305 }
306 case Q_XGETQSTAT: {
307 struct fs_quota_stat fqs;
308
309 if ((ret = sb->s_qcop->get_xstate(sb, &fqs)))
310 return ret;
311 if (copy_to_user(addr, &fqs, sizeof(fqs)))
312 return -EFAULT;
313 return 0;
314 }
315 case Q_XSETQLIM: {
316 struct fs_disk_quota fdq;
317
318 if (copy_from_user(&fdq, addr, sizeof(fdq)))
319 return -EFAULT;
320 return sb->s_qcop->set_xquota(sb, type, id, &fdq);
321 }
322 case Q_XGETQUOTA: {
323 struct fs_disk_quota fdq;
324
325 if ((ret = sb->s_qcop->get_xquota(sb, type, id, &fdq)))
326 return ret;
327 if (copy_to_user(addr, &fdq, sizeof(fdq)))
328 return -EFAULT;
329 return 0;
330 }
Nathan Scottde69e5f2005-11-03 13:53:34 +1100331 case Q_XQUOTASYNC:
332 return sb->s_qcop->quota_sync(sb, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 /* We never reach here unless validity check is broken */
334 default:
335 BUG();
336 }
337 return 0;
338}
339
340/*
David Howells93614012006-09-30 20:45:40 +0200341 * look up a superblock on which quota ops will be performed
342 * - use the name of a block device to find the superblock thereon
343 */
344static inline struct super_block *quotactl_block(const char __user *special)
345{
346#ifdef CONFIG_BLOCK
347 struct block_device *bdev;
348 struct super_block *sb;
349 char *tmp = getname(special);
350
351 if (IS_ERR(tmp))
David Howellse231c2e2008-02-07 00:15:26 -0800352 return ERR_CAST(tmp);
David Howells93614012006-09-30 20:45:40 +0200353 bdev = lookup_bdev(tmp);
354 putname(tmp);
355 if (IS_ERR(bdev))
David Howellse231c2e2008-02-07 00:15:26 -0800356 return ERR_CAST(bdev);
David Howells93614012006-09-30 20:45:40 +0200357 sb = get_super(bdev);
358 bdput(bdev);
359 if (!sb)
360 return ERR_PTR(-ENODEV);
361
362 return sb;
363#else
364 return ERR_PTR(-ENODEV);
365#endif
366}
367
368/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 * This is the system call interface. This communicates with
370 * the user-level programs. Currently this only supports diskquota
371 * calls. Maybe we need to add the process quotas etc. in the future,
372 * but we probably should use rlimits for that.
373 */
374asmlinkage long sys_quotactl(unsigned int cmd, const char __user *special, qid_t id, void __user *addr)
375{
376 uint cmds, type;
377 struct super_block *sb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 int ret;
379
380 cmds = cmd >> SUBCMDSHIFT;
381 type = cmd & SUBCMDMASK;
382
383 if (cmds != Q_SYNC || special) {
David Howells93614012006-09-30 20:45:40 +0200384 sb = quotactl_block(special);
385 if (IS_ERR(sb))
386 return PTR_ERR(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 }
388
389 ret = check_quotactl_valid(sb, type, cmds, id);
390 if (ret >= 0)
391 ret = do_quotactl(sb, type, cmds, id, addr);
392 if (sb)
393 drop_super(sb);
394
395 return ret;
396}
Vasily Tarasovb7163952007-07-15 23:41:12 -0700397
Tony Luck7a6c8132007-07-27 15:35:43 -0700398#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT)
Vasily Tarasovb7163952007-07-15 23:41:12 -0700399/*
400 * This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
401 * and is necessary due to alignment problems.
402 */
403struct compat_if_dqblk {
404 compat_u64 dqb_bhardlimit;
405 compat_u64 dqb_bsoftlimit;
406 compat_u64 dqb_curspace;
407 compat_u64 dqb_ihardlimit;
408 compat_u64 dqb_isoftlimit;
409 compat_u64 dqb_curinodes;
410 compat_u64 dqb_btime;
411 compat_u64 dqb_itime;
412 compat_uint_t dqb_valid;
413};
414
415/* XFS structures */
416struct compat_fs_qfilestat {
417 compat_u64 dqb_bhardlimit;
418 compat_u64 qfs_nblks;
419 compat_uint_t qfs_nextents;
420};
421
422struct compat_fs_quota_stat {
423 __s8 qs_version;
424 __u16 qs_flags;
425 __s8 qs_pad;
426 struct compat_fs_qfilestat qs_uquota;
427 struct compat_fs_qfilestat qs_gquota;
428 compat_uint_t qs_incoredqs;
429 compat_int_t qs_btimelimit;
430 compat_int_t qs_itimelimit;
431 compat_int_t qs_rtbtimelimit;
432 __u16 qs_bwarnlimit;
433 __u16 qs_iwarnlimit;
434};
435
436asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
437 qid_t id, void __user *addr)
438{
439 unsigned int cmds;
440 struct if_dqblk __user *dqblk;
441 struct compat_if_dqblk __user *compat_dqblk;
442 struct fs_quota_stat __user *fsqstat;
443 struct compat_fs_quota_stat __user *compat_fsqstat;
444 compat_uint_t data;
445 u16 xdata;
446 long ret;
447
448 cmds = cmd >> SUBCMDSHIFT;
449
450 switch (cmds) {
451 case Q_GETQUOTA:
452 dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
453 compat_dqblk = addr;
454 ret = sys_quotactl(cmd, special, id, dqblk);
455 if (ret)
456 break;
457 if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) ||
458 get_user(data, &dqblk->dqb_valid) ||
459 put_user(data, &compat_dqblk->dqb_valid))
460 ret = -EFAULT;
461 break;
462 case Q_SETQUOTA:
463 dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
464 compat_dqblk = addr;
465 ret = -EFAULT;
466 if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) ||
467 get_user(data, &compat_dqblk->dqb_valid) ||
468 put_user(data, &dqblk->dqb_valid))
469 break;
470 ret = sys_quotactl(cmd, special, id, dqblk);
471 break;
472 case Q_XGETQSTAT:
473 fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
474 compat_fsqstat = addr;
475 ret = sys_quotactl(cmd, special, id, fsqstat);
476 if (ret)
477 break;
478 ret = -EFAULT;
479 /* Copying qs_version, qs_flags, qs_pad */
480 if (copy_in_user(compat_fsqstat, fsqstat,
481 offsetof(struct compat_fs_quota_stat, qs_uquota)))
482 break;
483 /* Copying qs_uquota */
484 if (copy_in_user(&compat_fsqstat->qs_uquota,
485 &fsqstat->qs_uquota,
486 sizeof(compat_fsqstat->qs_uquota)) ||
487 get_user(data, &fsqstat->qs_uquota.qfs_nextents) ||
488 put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
489 break;
490 /* Copying qs_gquota */
491 if (copy_in_user(&compat_fsqstat->qs_gquota,
492 &fsqstat->qs_gquota,
493 sizeof(compat_fsqstat->qs_gquota)) ||
494 get_user(data, &fsqstat->qs_gquota.qfs_nextents) ||
495 put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
496 break;
497 /* Copying the rest */
498 if (copy_in_user(&compat_fsqstat->qs_incoredqs,
499 &fsqstat->qs_incoredqs,
500 sizeof(struct compat_fs_quota_stat) -
501 offsetof(struct compat_fs_quota_stat, qs_incoredqs)) ||
502 get_user(xdata, &fsqstat->qs_iwarnlimit) ||
503 put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
504 break;
505 ret = 0;
506 break;
507 default:
508 ret = sys_quotactl(cmd, special, id, addr);
509 }
510 return ret;
511}
512#endif