Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
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> | |
1da177e4 LT |
14 | #include <linux/security.h> |
15 | #include <linux/syscalls.h> | |
16 | #include <linux/buffer_head.h> | |
16f7e0fe | 17 | #include <linux/capability.h> |
be586bab | 18 | #include <linux/quotaops.h> |
b716395e | 19 | #include <linux/types.h> |
8c4e4acd | 20 | #include <linux/writeback.h> |
1da177e4 | 21 | |
c988afb5 CH |
22 | static int check_quotactl_permission(struct super_block *sb, int type, int cmd, |
23 | qid_t id) | |
1da177e4 | 24 | { |
c988afb5 CH |
25 | 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: | |
1da177e4 LT |
41 | if (!capable(CAP_SYS_ADMIN)) |
42 | return -EPERM; | |
43 | } | |
44 | ||
c988afb5 | 45 | return security_quotactl(cmd, type, id, sb); |
1da177e4 LT |
46 | } |
47 | ||
6ae09575 | 48 | static int quota_sync_all(int type) |
1da177e4 | 49 | { |
850b201b | 50 | struct super_block *sb; |
6ae09575 CH |
51 | int ret; |
52 | ||
53 | if (type >= MAXQUOTAS) | |
54 | return -EINVAL; | |
55 | ret = security_quotactl(Q_SYNC, type, 0, NULL); | |
56 | if (ret) | |
57 | return ret; | |
618f0636 | 58 | |
618f0636 KK |
59 | spin_lock(&sb_lock); |
60 | restart: | |
61 | list_for_each_entry(sb, &super_blocks, s_list) { | |
5fb324ad CH |
62 | if (!sb->s_qcop || !sb->s_qcop->quota_sync) |
63 | continue; | |
64 | ||
618f0636 KK |
65 | sb->s_count++; |
66 | spin_unlock(&sb_lock); | |
67 | down_read(&sb->s_umount); | |
850b201b | 68 | if (sb->s_root) |
5fb324ad | 69 | sb->s_qcop->quota_sync(sb, type, 1); |
618f0636 KK |
70 | up_read(&sb->s_umount); |
71 | spin_lock(&sb_lock); | |
72 | if (__put_super_and_need_restart(sb)) | |
73 | goto restart; | |
1da177e4 | 74 | } |
618f0636 | 75 | spin_unlock(&sb_lock); |
6ae09575 CH |
76 | |
77 | return 0; | |
1da177e4 LT |
78 | } |
79 | ||
c411e5f6 CH |
80 | static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id, |
81 | void __user *addr) | |
1da177e4 | 82 | { |
c411e5f6 | 83 | char *pathname; |
f450d4fe | 84 | int ret = -ENOSYS; |
1da177e4 | 85 | |
c411e5f6 CH |
86 | pathname = getname(addr); |
87 | if (IS_ERR(pathname)) | |
88 | return PTR_ERR(pathname); | |
f450d4fe CH |
89 | if (sb->s_qcop->quota_on) |
90 | ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0); | |
c411e5f6 CH |
91 | putname(pathname); |
92 | return ret; | |
93 | } | |
1da177e4 | 94 | |
c411e5f6 CH |
95 | static int quota_getfmt(struct super_block *sb, int type, void __user *addr) |
96 | { | |
97 | __u32 fmt; | |
1da177e4 | 98 | |
c411e5f6 CH |
99 | down_read(&sb_dqopt(sb)->dqptr_sem); |
100 | if (!sb_has_quota_active(sb, type)) { | |
101 | up_read(&sb_dqopt(sb)->dqptr_sem); | |
102 | return -ESRCH; | |
103 | } | |
104 | fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id; | |
105 | up_read(&sb_dqopt(sb)->dqptr_sem); | |
106 | if (copy_to_user(addr, &fmt, sizeof(fmt))) | |
107 | return -EFAULT; | |
108 | return 0; | |
109 | } | |
1da177e4 | 110 | |
c411e5f6 CH |
111 | static int quota_getinfo(struct super_block *sb, int type, void __user *addr) |
112 | { | |
113 | struct if_dqinfo info; | |
114 | int ret; | |
1da177e4 | 115 | |
f450d4fe CH |
116 | if (!sb_has_quota_active(sb, type)) |
117 | return -ESRCH; | |
118 | if (!sb->s_qcop->get_info) | |
119 | return -ENOSYS; | |
c411e5f6 CH |
120 | ret = sb->s_qcop->get_info(sb, type, &info); |
121 | if (!ret && copy_to_user(addr, &info, sizeof(info))) | |
122 | return -EFAULT; | |
123 | return ret; | |
124 | } | |
1da177e4 | 125 | |
c411e5f6 CH |
126 | static int quota_setinfo(struct super_block *sb, int type, void __user *addr) |
127 | { | |
128 | struct if_dqinfo info; | |
1da177e4 | 129 | |
c411e5f6 CH |
130 | if (copy_from_user(&info, addr, sizeof(info))) |
131 | return -EFAULT; | |
f450d4fe CH |
132 | if (!sb_has_quota_active(sb, type)) |
133 | return -ESRCH; | |
134 | if (!sb->s_qcop->set_info) | |
135 | return -ENOSYS; | |
c411e5f6 CH |
136 | return sb->s_qcop->set_info(sb, type, &info); |
137 | } | |
138 | ||
139 | static int quota_getquota(struct super_block *sb, int type, qid_t id, | |
140 | void __user *addr) | |
141 | { | |
142 | struct if_dqblk idq; | |
143 | int ret; | |
144 | ||
f450d4fe CH |
145 | if (!sb_has_quota_active(sb, type)) |
146 | return -ESRCH; | |
147 | if (!sb->s_qcop->get_dqblk) | |
148 | return -ENOSYS; | |
c411e5f6 CH |
149 | ret = sb->s_qcop->get_dqblk(sb, type, id, &idq); |
150 | if (ret) | |
151 | return ret; | |
152 | if (copy_to_user(addr, &idq, sizeof(idq))) | |
153 | return -EFAULT; | |
154 | return 0; | |
155 | } | |
156 | ||
157 | static int quota_setquota(struct super_block *sb, int type, qid_t id, | |
158 | void __user *addr) | |
159 | { | |
160 | struct if_dqblk idq; | |
161 | ||
162 | if (copy_from_user(&idq, addr, sizeof(idq))) | |
163 | return -EFAULT; | |
f450d4fe CH |
164 | if (!sb_has_quota_active(sb, type)) |
165 | return -ESRCH; | |
166 | if (!sb->s_qcop->set_dqblk) | |
167 | return -ENOSYS; | |
c411e5f6 CH |
168 | return sb->s_qcop->set_dqblk(sb, type, id, &idq); |
169 | } | |
170 | ||
171 | static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr) | |
172 | { | |
173 | __u32 flags; | |
174 | ||
175 | if (copy_from_user(&flags, addr, sizeof(flags))) | |
176 | return -EFAULT; | |
f450d4fe CH |
177 | if (!sb->s_qcop->set_xstate) |
178 | return -ENOSYS; | |
c411e5f6 CH |
179 | return sb->s_qcop->set_xstate(sb, flags, cmd); |
180 | } | |
181 | ||
182 | static int quota_getxstate(struct super_block *sb, void __user *addr) | |
183 | { | |
184 | struct fs_quota_stat fqs; | |
185 | int ret; | |
f450d4fe CH |
186 | |
187 | if (!sb->s_qcop->get_xstate) | |
188 | return -ENOSYS; | |
c411e5f6 CH |
189 | ret = sb->s_qcop->get_xstate(sb, &fqs); |
190 | if (!ret && copy_to_user(addr, &fqs, sizeof(fqs))) | |
191 | return -EFAULT; | |
192 | return ret; | |
193 | } | |
1da177e4 | 194 | |
c411e5f6 CH |
195 | static int quota_setxquota(struct super_block *sb, int type, qid_t id, |
196 | void __user *addr) | |
197 | { | |
198 | struct fs_disk_quota fdq; | |
199 | ||
200 | if (copy_from_user(&fdq, addr, sizeof(fdq))) | |
201 | return -EFAULT; | |
f450d4fe CH |
202 | if (!sb->s_qcop->set_xquota) |
203 | return -ENOSYS; | |
c411e5f6 CH |
204 | return sb->s_qcop->set_xquota(sb, type, id, &fdq); |
205 | } | |
206 | ||
207 | static int quota_getxquota(struct super_block *sb, int type, qid_t id, | |
208 | void __user *addr) | |
209 | { | |
210 | struct fs_disk_quota fdq; | |
211 | int ret; | |
212 | ||
f450d4fe CH |
213 | if (!sb->s_qcop->get_xquota) |
214 | return -ENOSYS; | |
c411e5f6 CH |
215 | ret = sb->s_qcop->get_xquota(sb, type, id, &fdq); |
216 | if (!ret && copy_to_user(addr, &fdq, sizeof(fdq))) | |
217 | return -EFAULT; | |
218 | return ret; | |
219 | } | |
220 | ||
221 | /* Copy parameters and call proper function */ | |
222 | static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, | |
223 | void __user *addr) | |
224 | { | |
c988afb5 CH |
225 | int ret; |
226 | ||
227 | if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS)) | |
228 | return -EINVAL; | |
229 | if (!sb->s_qcop) | |
230 | return -ENOSYS; | |
231 | ||
232 | ret = check_quotactl_permission(sb, type, cmd, id); | |
233 | if (ret < 0) | |
234 | return ret; | |
235 | ||
c411e5f6 CH |
236 | switch (cmd) { |
237 | case Q_QUOTAON: | |
238 | return quota_quotaon(sb, type, cmd, id, addr); | |
239 | case Q_QUOTAOFF: | |
f450d4fe CH |
240 | if (!sb->s_qcop->quota_off) |
241 | return -ENOSYS; | |
c411e5f6 CH |
242 | return sb->s_qcop->quota_off(sb, type, 0); |
243 | case Q_GETFMT: | |
244 | return quota_getfmt(sb, type, addr); | |
245 | case Q_GETINFO: | |
246 | return quota_getinfo(sb, type, addr); | |
247 | case Q_SETINFO: | |
248 | return quota_setinfo(sb, type, addr); | |
249 | case Q_GETQUOTA: | |
250 | return quota_getquota(sb, type, id, addr); | |
251 | case Q_SETQUOTA: | |
252 | return quota_setquota(sb, type, id, addr); | |
253 | case Q_SYNC: | |
6ae09575 CH |
254 | if (!sb->s_qcop->quota_sync) |
255 | return -ENOSYS; | |
5fb324ad | 256 | return sb->s_qcop->quota_sync(sb, type, 1); |
c411e5f6 CH |
257 | case Q_XQUOTAON: |
258 | case Q_XQUOTAOFF: | |
259 | case Q_XQUOTARM: | |
260 | return quota_setxstate(sb, cmd, addr); | |
261 | case Q_XGETQSTAT: | |
262 | return quota_getxstate(sb, addr); | |
263 | case Q_XSETQLIM: | |
264 | return quota_setxquota(sb, type, id, addr); | |
265 | case Q_XGETQUOTA: | |
266 | return quota_getxquota(sb, type, id, addr); | |
267 | case Q_XQUOTASYNC: | |
8c4e4acd CH |
268 | /* caller already holds s_umount */ |
269 | if (sb->s_flags & MS_RDONLY) | |
270 | return -EROFS; | |
271 | writeback_inodes_sb(sb); | |
272 | return 0; | |
c411e5f6 | 273 | default: |
f450d4fe | 274 | return -EINVAL; |
1da177e4 | 275 | } |
1da177e4 LT |
276 | } |
277 | ||
9361401e DH |
278 | /* |
279 | * look up a superblock on which quota ops will be performed | |
280 | * - use the name of a block device to find the superblock thereon | |
281 | */ | |
7a2435d8 | 282 | static struct super_block *quotactl_block(const char __user *special) |
9361401e DH |
283 | { |
284 | #ifdef CONFIG_BLOCK | |
285 | struct block_device *bdev; | |
286 | struct super_block *sb; | |
287 | char *tmp = getname(special); | |
288 | ||
289 | if (IS_ERR(tmp)) | |
e231c2ee | 290 | return ERR_CAST(tmp); |
9361401e DH |
291 | bdev = lookup_bdev(tmp); |
292 | putname(tmp); | |
293 | if (IS_ERR(bdev)) | |
e231c2ee | 294 | return ERR_CAST(bdev); |
9361401e DH |
295 | sb = get_super(bdev); |
296 | bdput(bdev); | |
297 | if (!sb) | |
298 | return ERR_PTR(-ENODEV); | |
299 | ||
300 | return sb; | |
301 | #else | |
302 | return ERR_PTR(-ENODEV); | |
303 | #endif | |
304 | } | |
305 | ||
1da177e4 LT |
306 | /* |
307 | * This is the system call interface. This communicates with | |
308 | * the user-level programs. Currently this only supports diskquota | |
309 | * calls. Maybe we need to add the process quotas etc. in the future, | |
310 | * but we probably should use rlimits for that. | |
311 | */ | |
3cdad428 HC |
312 | SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, |
313 | qid_t, id, void __user *, addr) | |
1da177e4 LT |
314 | { |
315 | uint cmds, type; | |
316 | struct super_block *sb = NULL; | |
1da177e4 LT |
317 | int ret; |
318 | ||
319 | cmds = cmd >> SUBCMDSHIFT; | |
320 | type = cmd & SUBCMDMASK; | |
321 | ||
6ae09575 CH |
322 | /* |
323 | * As a special case Q_SYNC can be called without a specific device. | |
324 | * It will iterate all superblocks that have quota enabled and call | |
325 | * the sync action on each of them. | |
326 | */ | |
327 | if (!special) { | |
328 | if (cmds == Q_SYNC) | |
329 | return quota_sync_all(type); | |
330 | return -ENODEV; | |
1da177e4 LT |
331 | } |
332 | ||
6ae09575 CH |
333 | sb = quotactl_block(special); |
334 | if (IS_ERR(sb)) | |
335 | return PTR_ERR(sb); | |
336 | ||
c988afb5 | 337 | ret = do_quotactl(sb, type, cmds, id, addr); |
1da177e4 | 338 | |
6ae09575 | 339 | drop_super(sb); |
1da177e4 LT |
340 | return ret; |
341 | } |