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Commit | Line | Data |
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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 | ||
b9b2dd36 CH |
139 | static void copy_to_if_dqblk(struct if_dqblk *dst, struct fs_disk_quota *src) |
140 | { | |
141 | dst->dqb_bhardlimit = src->d_blk_hardlimit; | |
142 | dst->dqb_bsoftlimit = src->d_blk_softlimit; | |
143 | dst->dqb_curspace = src->d_bcount; | |
144 | dst->dqb_ihardlimit = src->d_ino_hardlimit; | |
145 | dst->dqb_isoftlimit = src->d_ino_softlimit; | |
146 | dst->dqb_curinodes = src->d_icount; | |
147 | dst->dqb_btime = src->d_btimer; | |
148 | dst->dqb_itime = src->d_itimer; | |
149 | dst->dqb_valid = QIF_ALL; | |
150 | } | |
151 | ||
c411e5f6 CH |
152 | static int quota_getquota(struct super_block *sb, int type, qid_t id, |
153 | void __user *addr) | |
154 | { | |
b9b2dd36 | 155 | struct fs_disk_quota fdq; |
c411e5f6 CH |
156 | struct if_dqblk idq; |
157 | int ret; | |
158 | ||
f450d4fe CH |
159 | if (!sb->s_qcop->get_dqblk) |
160 | return -ENOSYS; | |
b9b2dd36 | 161 | ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq); |
c411e5f6 CH |
162 | if (ret) |
163 | return ret; | |
b9b2dd36 | 164 | copy_to_if_dqblk(&idq, &fdq); |
c411e5f6 CH |
165 | if (copy_to_user(addr, &idq, sizeof(idq))) |
166 | return -EFAULT; | |
167 | return 0; | |
168 | } | |
169 | ||
170 | static int quota_setquota(struct super_block *sb, int type, qid_t id, | |
171 | void __user *addr) | |
172 | { | |
173 | struct if_dqblk idq; | |
174 | ||
175 | if (copy_from_user(&idq, addr, sizeof(idq))) | |
176 | return -EFAULT; | |
f450d4fe CH |
177 | if (!sb_has_quota_active(sb, type)) |
178 | return -ESRCH; | |
179 | if (!sb->s_qcop->set_dqblk) | |
180 | return -ENOSYS; | |
c411e5f6 CH |
181 | return sb->s_qcop->set_dqblk(sb, type, id, &idq); |
182 | } | |
183 | ||
184 | static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr) | |
185 | { | |
186 | __u32 flags; | |
187 | ||
188 | if (copy_from_user(&flags, addr, sizeof(flags))) | |
189 | return -EFAULT; | |
f450d4fe CH |
190 | if (!sb->s_qcop->set_xstate) |
191 | return -ENOSYS; | |
c411e5f6 CH |
192 | return sb->s_qcop->set_xstate(sb, flags, cmd); |
193 | } | |
194 | ||
195 | static int quota_getxstate(struct super_block *sb, void __user *addr) | |
196 | { | |
197 | struct fs_quota_stat fqs; | |
198 | int ret; | |
f450d4fe CH |
199 | |
200 | if (!sb->s_qcop->get_xstate) | |
201 | return -ENOSYS; | |
c411e5f6 CH |
202 | ret = sb->s_qcop->get_xstate(sb, &fqs); |
203 | if (!ret && copy_to_user(addr, &fqs, sizeof(fqs))) | |
204 | return -EFAULT; | |
205 | return ret; | |
206 | } | |
1da177e4 | 207 | |
c411e5f6 CH |
208 | static int quota_setxquota(struct super_block *sb, int type, qid_t id, |
209 | void __user *addr) | |
210 | { | |
211 | struct fs_disk_quota fdq; | |
212 | ||
213 | if (copy_from_user(&fdq, addr, sizeof(fdq))) | |
214 | return -EFAULT; | |
f450d4fe CH |
215 | if (!sb->s_qcop->set_xquota) |
216 | return -ENOSYS; | |
c411e5f6 CH |
217 | return sb->s_qcop->set_xquota(sb, type, id, &fdq); |
218 | } | |
219 | ||
220 | static int quota_getxquota(struct super_block *sb, int type, qid_t id, | |
221 | void __user *addr) | |
222 | { | |
223 | struct fs_disk_quota fdq; | |
224 | int ret; | |
225 | ||
b9b2dd36 | 226 | if (!sb->s_qcop->get_dqblk) |
f450d4fe | 227 | return -ENOSYS; |
b9b2dd36 | 228 | ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq); |
c411e5f6 CH |
229 | if (!ret && copy_to_user(addr, &fdq, sizeof(fdq))) |
230 | return -EFAULT; | |
231 | return ret; | |
232 | } | |
233 | ||
234 | /* Copy parameters and call proper function */ | |
235 | static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, | |
236 | void __user *addr) | |
237 | { | |
c988afb5 CH |
238 | int ret; |
239 | ||
240 | if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS)) | |
241 | return -EINVAL; | |
242 | if (!sb->s_qcop) | |
243 | return -ENOSYS; | |
244 | ||
245 | ret = check_quotactl_permission(sb, type, cmd, id); | |
246 | if (ret < 0) | |
247 | return ret; | |
248 | ||
c411e5f6 CH |
249 | switch (cmd) { |
250 | case Q_QUOTAON: | |
251 | return quota_quotaon(sb, type, cmd, id, addr); | |
252 | case Q_QUOTAOFF: | |
f450d4fe CH |
253 | if (!sb->s_qcop->quota_off) |
254 | return -ENOSYS; | |
c411e5f6 CH |
255 | return sb->s_qcop->quota_off(sb, type, 0); |
256 | case Q_GETFMT: | |
257 | return quota_getfmt(sb, type, addr); | |
258 | case Q_GETINFO: | |
259 | return quota_getinfo(sb, type, addr); | |
260 | case Q_SETINFO: | |
261 | return quota_setinfo(sb, type, addr); | |
262 | case Q_GETQUOTA: | |
263 | return quota_getquota(sb, type, id, addr); | |
264 | case Q_SETQUOTA: | |
265 | return quota_setquota(sb, type, id, addr); | |
266 | case Q_SYNC: | |
6ae09575 CH |
267 | if (!sb->s_qcop->quota_sync) |
268 | return -ENOSYS; | |
5fb324ad | 269 | return sb->s_qcop->quota_sync(sb, type, 1); |
c411e5f6 CH |
270 | case Q_XQUOTAON: |
271 | case Q_XQUOTAOFF: | |
272 | case Q_XQUOTARM: | |
273 | return quota_setxstate(sb, cmd, addr); | |
274 | case Q_XGETQSTAT: | |
275 | return quota_getxstate(sb, addr); | |
276 | case Q_XSETQLIM: | |
277 | return quota_setxquota(sb, type, id, addr); | |
278 | case Q_XGETQUOTA: | |
279 | return quota_getxquota(sb, type, id, addr); | |
280 | case Q_XQUOTASYNC: | |
8c4e4acd CH |
281 | /* caller already holds s_umount */ |
282 | if (sb->s_flags & MS_RDONLY) | |
283 | return -EROFS; | |
284 | writeback_inodes_sb(sb); | |
285 | return 0; | |
c411e5f6 | 286 | default: |
f450d4fe | 287 | return -EINVAL; |
1da177e4 | 288 | } |
1da177e4 LT |
289 | } |
290 | ||
9361401e DH |
291 | /* |
292 | * look up a superblock on which quota ops will be performed | |
293 | * - use the name of a block device to find the superblock thereon | |
294 | */ | |
7a2435d8 | 295 | static struct super_block *quotactl_block(const char __user *special) |
9361401e DH |
296 | { |
297 | #ifdef CONFIG_BLOCK | |
298 | struct block_device *bdev; | |
299 | struct super_block *sb; | |
300 | char *tmp = getname(special); | |
301 | ||
302 | if (IS_ERR(tmp)) | |
e231c2ee | 303 | return ERR_CAST(tmp); |
9361401e DH |
304 | bdev = lookup_bdev(tmp); |
305 | putname(tmp); | |
306 | if (IS_ERR(bdev)) | |
e231c2ee | 307 | return ERR_CAST(bdev); |
9361401e DH |
308 | sb = get_super(bdev); |
309 | bdput(bdev); | |
310 | if (!sb) | |
311 | return ERR_PTR(-ENODEV); | |
312 | ||
313 | return sb; | |
314 | #else | |
315 | return ERR_PTR(-ENODEV); | |
316 | #endif | |
317 | } | |
318 | ||
1da177e4 LT |
319 | /* |
320 | * This is the system call interface. This communicates with | |
321 | * the user-level programs. Currently this only supports diskquota | |
322 | * calls. Maybe we need to add the process quotas etc. in the future, | |
323 | * but we probably should use rlimits for that. | |
324 | */ | |
3cdad428 HC |
325 | SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, |
326 | qid_t, id, void __user *, addr) | |
1da177e4 LT |
327 | { |
328 | uint cmds, type; | |
329 | struct super_block *sb = NULL; | |
1da177e4 LT |
330 | int ret; |
331 | ||
332 | cmds = cmd >> SUBCMDSHIFT; | |
333 | type = cmd & SUBCMDMASK; | |
334 | ||
6ae09575 CH |
335 | /* |
336 | * As a special case Q_SYNC can be called without a specific device. | |
337 | * It will iterate all superblocks that have quota enabled and call | |
338 | * the sync action on each of them. | |
339 | */ | |
340 | if (!special) { | |
341 | if (cmds == Q_SYNC) | |
342 | return quota_sync_all(type); | |
343 | return -ENODEV; | |
1da177e4 LT |
344 | } |
345 | ||
6ae09575 CH |
346 | sb = quotactl_block(special); |
347 | if (IS_ERR(sb)) | |
348 | return PTR_ERR(sb); | |
349 | ||
c988afb5 | 350 | ret = do_quotactl(sb, type, cmds, id, addr); |
1da177e4 | 351 | |
6ae09575 | 352 | drop_super(sb); |
1da177e4 LT |
353 | return ret; |
354 | } |