blob: b34bdb25490c8956b4733c29771bea3109ec2fcf [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>
13#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/security.h>
15#include <linux/syscalls.h>
16#include <linux/buffer_head.h>
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080017#include <linux/capability.h>
Adrian Bunkbe586ba2005-11-07 00:59:35 -080018#include <linux/quotaops.h>
Vasily Tarasovb7163952007-07-15 23:41:12 -070019#include <linux/types.h>
Christoph Hellwig8c4e4ac2010-02-16 03:44:51 -050020#include <linux/writeback.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
Christoph Hellwigc988afb2010-02-16 03:44:50 -050022static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
23 qid_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -070024{
Christoph Hellwigc988afb2010-02-16 03:44:50 -050025 switch (cmd) {
26 /* these commands do not require any special privilegues */
27 case Q_GETFMT:
28 case Q_SYNC:
29 case Q_GETINFO:
30 case Q_XGETQSTAT:
31 case Q_XQUOTASYNC:
32 break;
33 /* allow to query information for dquots we "own" */
34 case Q_GETQUOTA:
35 case Q_XGETQUOTA:
36 if ((type == USRQUOTA && current_euid() == id) ||
37 (type == GRPQUOTA && in_egroup_p(id)))
38 break;
39 /*FALLTHROUGH*/
40 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 if (!capable(CAP_SYS_ADMIN))
42 return -EPERM;
43 }
44
Christoph Hellwigc988afb2010-02-16 03:44:50 -050045 return security_quotactl(cmd, type, id, sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070046}
47
Al Viro01a05b32010-03-23 06:06:58 -040048static void quota_sync_one(struct super_block *sb, void *arg)
49{
50 if (sb->s_qcop && sb->s_qcop->quota_sync)
51 sb->s_qcop->quota_sync(sb, *(int *)arg, 1);
52}
53
Christoph Hellwig6ae09572010-02-16 03:44:49 -050054static int quota_sync_all(int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -070055{
Christoph Hellwig6ae09572010-02-16 03:44:49 -050056 int ret;
57
58 if (type >= MAXQUOTAS)
59 return -EINVAL;
60 ret = security_quotactl(Q_SYNC, type, 0, NULL);
Al Viro01a05b32010-03-23 06:06:58 -040061 if (!ret)
62 iterate_supers(quota_sync_one, &type);
63 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064}
65
Christoph Hellwigc411e5f2010-02-16 03:44:47 -050066static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
Jan Karaf00c9e42010-09-15 17:38:58 +020067 struct path *path)
Christoph Hellwigc411e5f2010-02-16 03:44:47 -050068{
Jan Karaf00c9e42010-09-15 17:38:58 +020069 if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_on_meta)
70 return -ENOSYS;
71 if (sb->s_qcop->quota_on_meta)
72 return sb->s_qcop->quota_on_meta(sb, type, id);
73 if (IS_ERR(path))
74 return PTR_ERR(path);
75 return sb->s_qcop->quota_on(sb, type, id, path);
Christoph Hellwigc411e5f2010-02-16 03:44:47 -050076}
77
78static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
79{
80 __u32 fmt;
81
82 down_read(&sb_dqopt(sb)->dqptr_sem);
83 if (!sb_has_quota_active(sb, type)) {
84 up_read(&sb_dqopt(sb)->dqptr_sem);
85 return -ESRCH;
86 }
87 fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
88 up_read(&sb_dqopt(sb)->dqptr_sem);
89 if (copy_to_user(addr, &fmt, sizeof(fmt)))
90 return -EFAULT;
91 return 0;
92}
93
94static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
95{
96 struct if_dqinfo info;
97 int ret;
98
Christoph Hellwigf450d4f2010-02-16 03:44:48 -050099 if (!sb->s_qcop->get_info)
100 return -ENOSYS;
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500101 ret = sb->s_qcop->get_info(sb, type, &info);
102 if (!ret && copy_to_user(addr, &info, sizeof(info)))
103 return -EFAULT;
104 return ret;
105}
106
107static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
108{
109 struct if_dqinfo info;
110
111 if (copy_from_user(&info, addr, sizeof(info)))
112 return -EFAULT;
Christoph Hellwigf450d4f2010-02-16 03:44:48 -0500113 if (!sb->s_qcop->set_info)
114 return -ENOSYS;
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500115 return sb->s_qcop->set_info(sb, type, &info);
116}
117
Christoph Hellwigb9b2dd32010-05-06 17:04:58 -0400118static void copy_to_if_dqblk(struct if_dqblk *dst, struct fs_disk_quota *src)
119{
120 dst->dqb_bhardlimit = src->d_blk_hardlimit;
121 dst->dqb_bsoftlimit = src->d_blk_softlimit;
122 dst->dqb_curspace = src->d_bcount;
123 dst->dqb_ihardlimit = src->d_ino_hardlimit;
124 dst->dqb_isoftlimit = src->d_ino_softlimit;
125 dst->dqb_curinodes = src->d_icount;
126 dst->dqb_btime = src->d_btimer;
127 dst->dqb_itime = src->d_itimer;
128 dst->dqb_valid = QIF_ALL;
129}
130
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500131static int quota_getquota(struct super_block *sb, int type, qid_t id,
132 void __user *addr)
133{
Christoph Hellwigb9b2dd32010-05-06 17:04:58 -0400134 struct fs_disk_quota fdq;
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500135 struct if_dqblk idq;
136 int ret;
137
Christoph Hellwigf450d4f2010-02-16 03:44:48 -0500138 if (!sb->s_qcop->get_dqblk)
139 return -ENOSYS;
Christoph Hellwigb9b2dd32010-05-06 17:04:58 -0400140 ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq);
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500141 if (ret)
142 return ret;
Christoph Hellwigb9b2dd32010-05-06 17:04:58 -0400143 copy_to_if_dqblk(&idq, &fdq);
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500144 if (copy_to_user(addr, &idq, sizeof(idq)))
145 return -EFAULT;
146 return 0;
147}
148
Christoph Hellwigc472b432010-05-06 17:05:17 -0400149static void copy_from_if_dqblk(struct fs_disk_quota *dst, struct if_dqblk *src)
150{
151 dst->d_blk_hardlimit = src->dqb_bhardlimit;
152 dst->d_blk_softlimit = src->dqb_bsoftlimit;
153 dst->d_bcount = src->dqb_curspace;
154 dst->d_ino_hardlimit = src->dqb_ihardlimit;
155 dst->d_ino_softlimit = src->dqb_isoftlimit;
156 dst->d_icount = src->dqb_curinodes;
157 dst->d_btimer = src->dqb_btime;
158 dst->d_itimer = src->dqb_itime;
159
160 dst->d_fieldmask = 0;
161 if (src->dqb_valid & QIF_BLIMITS)
162 dst->d_fieldmask |= FS_DQ_BSOFT | FS_DQ_BHARD;
163 if (src->dqb_valid & QIF_SPACE)
164 dst->d_fieldmask |= FS_DQ_BCOUNT;
165 if (src->dqb_valid & QIF_ILIMITS)
166 dst->d_fieldmask |= FS_DQ_ISOFT | FS_DQ_IHARD;
167 if (src->dqb_valid & QIF_INODES)
168 dst->d_fieldmask |= FS_DQ_ICOUNT;
169 if (src->dqb_valid & QIF_BTIME)
170 dst->d_fieldmask |= FS_DQ_BTIMER;
171 if (src->dqb_valid & QIF_ITIME)
172 dst->d_fieldmask |= FS_DQ_ITIMER;
173}
174
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500175static int quota_setquota(struct super_block *sb, int type, qid_t id,
176 void __user *addr)
177{
Christoph Hellwigc472b432010-05-06 17:05:17 -0400178 struct fs_disk_quota fdq;
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500179 struct if_dqblk idq;
180
181 if (copy_from_user(&idq, addr, sizeof(idq)))
182 return -EFAULT;
Christoph Hellwigf450d4f2010-02-16 03:44:48 -0500183 if (!sb->s_qcop->set_dqblk)
184 return -ENOSYS;
Christoph Hellwigc472b432010-05-06 17:05:17 -0400185 copy_from_if_dqblk(&fdq, &idq);
186 return sb->s_qcop->set_dqblk(sb, type, id, &fdq);
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500187}
188
189static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
190{
191 __u32 flags;
192
193 if (copy_from_user(&flags, addr, sizeof(flags)))
194 return -EFAULT;
Christoph Hellwigf450d4f2010-02-16 03:44:48 -0500195 if (!sb->s_qcop->set_xstate)
196 return -ENOSYS;
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500197 return sb->s_qcop->set_xstate(sb, flags, cmd);
198}
199
200static int quota_getxstate(struct super_block *sb, void __user *addr)
201{
202 struct fs_quota_stat fqs;
203 int ret;
Christoph Hellwigf450d4f2010-02-16 03:44:48 -0500204
205 if (!sb->s_qcop->get_xstate)
206 return -ENOSYS;
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500207 ret = sb->s_qcop->get_xstate(sb, &fqs);
208 if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
209 return -EFAULT;
210 return ret;
211}
212
213static int quota_setxquota(struct super_block *sb, int type, qid_t id,
214 void __user *addr)
215{
216 struct fs_disk_quota fdq;
217
218 if (copy_from_user(&fdq, addr, sizeof(fdq)))
219 return -EFAULT;
Christoph Hellwigc472b432010-05-06 17:05:17 -0400220 if (!sb->s_qcop->set_dqblk)
Christoph Hellwigf450d4f2010-02-16 03:44:48 -0500221 return -ENOSYS;
Christoph Hellwigc472b432010-05-06 17:05:17 -0400222 return sb->s_qcop->set_dqblk(sb, type, id, &fdq);
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500223}
224
225static int quota_getxquota(struct super_block *sb, int type, qid_t id,
226 void __user *addr)
227{
228 struct fs_disk_quota fdq;
229 int ret;
230
Christoph Hellwigb9b2dd32010-05-06 17:04:58 -0400231 if (!sb->s_qcop->get_dqblk)
Christoph Hellwigf450d4f2010-02-16 03:44:48 -0500232 return -ENOSYS;
Christoph Hellwigb9b2dd32010-05-06 17:04:58 -0400233 ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq);
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500234 if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
235 return -EFAULT;
236 return ret;
237}
238
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239/* Copy parameters and call proper function */
Jan Kara268157b2009-01-27 15:47:22 +0100240static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
Jan Karaf00c9e42010-09-15 17:38:58 +0200241 void __user *addr, struct path *path)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242{
Christoph Hellwigc988afb2010-02-16 03:44:50 -0500243 int ret;
244
245 if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
246 return -EINVAL;
247 if (!sb->s_qcop)
248 return -ENOSYS;
249
250 ret = check_quotactl_permission(sb, type, cmd, id);
251 if (ret < 0)
252 return ret;
253
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 switch (cmd) {
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500255 case Q_QUOTAON:
Jan Karaf00c9e42010-09-15 17:38:58 +0200256 return quota_quotaon(sb, type, cmd, id, path);
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500257 case Q_QUOTAOFF:
Christoph Hellwigf450d4f2010-02-16 03:44:48 -0500258 if (!sb->s_qcop->quota_off)
259 return -ENOSYS;
Christoph Hellwig307ae182010-05-19 07:16:43 -0400260 return sb->s_qcop->quota_off(sb, type);
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500261 case Q_GETFMT:
262 return quota_getfmt(sb, type, addr);
263 case Q_GETINFO:
264 return quota_getinfo(sb, type, addr);
265 case Q_SETINFO:
266 return quota_setinfo(sb, type, addr);
267 case Q_GETQUOTA:
268 return quota_getquota(sb, type, id, addr);
269 case Q_SETQUOTA:
270 return quota_setquota(sb, type, id, addr);
271 case Q_SYNC:
Christoph Hellwig6ae09572010-02-16 03:44:49 -0500272 if (!sb->s_qcop->quota_sync)
273 return -ENOSYS;
Christoph Hellwig5fb324a2010-02-16 03:44:52 -0500274 return sb->s_qcop->quota_sync(sb, type, 1);
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500275 case Q_XQUOTAON:
276 case Q_XQUOTAOFF:
277 case Q_XQUOTARM:
278 return quota_setxstate(sb, cmd, addr);
279 case Q_XGETQSTAT:
280 return quota_getxstate(sb, addr);
281 case Q_XSETQLIM:
282 return quota_setxquota(sb, type, id, addr);
283 case Q_XGETQUOTA:
284 return quota_getxquota(sb, type, id, addr);
285 case Q_XQUOTASYNC:
Christoph Hellwig8c4e4ac2010-02-16 03:44:51 -0500286 /* caller already holds s_umount */
287 if (sb->s_flags & MS_RDONLY)
288 return -EROFS;
289 writeback_inodes_sb(sb);
290 return 0;
Christoph Hellwigc411e5f2010-02-16 03:44:47 -0500291 default:
Christoph Hellwigf450d4f2010-02-16 03:44:48 -0500292 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294}
295
296/*
David Howells93614012006-09-30 20:45:40 +0200297 * look up a superblock on which quota ops will be performed
298 * - use the name of a block device to find the superblock thereon
299 */
Jan Kara7a2435d2009-01-27 01:47:11 +0100300static struct super_block *quotactl_block(const char __user *special)
David Howells93614012006-09-30 20:45:40 +0200301{
302#ifdef CONFIG_BLOCK
303 struct block_device *bdev;
304 struct super_block *sb;
305 char *tmp = getname(special);
306
307 if (IS_ERR(tmp))
David Howellse231c2e2008-02-07 00:15:26 -0800308 return ERR_CAST(tmp);
David Howells93614012006-09-30 20:45:40 +0200309 bdev = lookup_bdev(tmp);
310 putname(tmp);
311 if (IS_ERR(bdev))
David Howellse231c2e2008-02-07 00:15:26 -0800312 return ERR_CAST(bdev);
David Howells93614012006-09-30 20:45:40 +0200313 sb = get_super(bdev);
314 bdput(bdev);
315 if (!sb)
316 return ERR_PTR(-ENODEV);
317
318 return sb;
319#else
320 return ERR_PTR(-ENODEV);
321#endif
322}
323
324/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 * This is the system call interface. This communicates with
326 * the user-level programs. Currently this only supports diskquota
327 * calls. Maybe we need to add the process quotas etc. in the future,
328 * but we probably should use rlimits for that.
329 */
Heiko Carstens3cdad422009-01-14 14:14:22 +0100330SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
331 qid_t, id, void __user *, addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332{
333 uint cmds, type;
334 struct super_block *sb = NULL;
Jan Karaf00c9e42010-09-15 17:38:58 +0200335 struct path path, *pathp = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 int ret;
337
338 cmds = cmd >> SUBCMDSHIFT;
339 type = cmd & SUBCMDMASK;
340
Christoph Hellwig6ae09572010-02-16 03:44:49 -0500341 /*
342 * As a special case Q_SYNC can be called without a specific device.
343 * It will iterate all superblocks that have quota enabled and call
344 * the sync action on each of them.
345 */
346 if (!special) {
347 if (cmds == Q_SYNC)
348 return quota_sync_all(type);
349 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 }
351
Jan Karaf00c9e42010-09-15 17:38:58 +0200352 /*
353 * Path for quotaon has to be resolved before grabbing superblock
354 * because that gets s_umount sem which is also possibly needed by path
355 * resolution (think about autofs) and thus deadlocks could arise.
356 */
357 if (cmds == Q_QUOTAON) {
358 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW, &path);
359 if (ret)
360 pathp = ERR_PTR(ret);
361 else
362 pathp = &path;
363 }
364
Christoph Hellwig6ae09572010-02-16 03:44:49 -0500365 sb = quotactl_block(special);
366 if (IS_ERR(sb))
367 return PTR_ERR(sb);
368
Jan Karaf00c9e42010-09-15 17:38:58 +0200369 ret = do_quotactl(sb, type, cmds, id, addr, pathp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
Christoph Hellwig6ae09572010-02-16 03:44:49 -0500371 drop_super(sb);
Jan Karaf00c9e42010-09-15 17:38:58 +0200372 if (pathp && !IS_ERR(pathp))
373 path_put(pathp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 return ret;
375}