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> | |
f3da9310 | 12 | #include <linux/uaccess.h> |
1da177e4 | 13 | #include <linux/kernel.h> |
1da177e4 LT |
14 | #include <linux/security.h> |
15 | #include <linux/syscalls.h> | |
16f7e0fe | 16 | #include <linux/capability.h> |
be586bab | 17 | #include <linux/quotaops.h> |
b716395e | 18 | #include <linux/types.h> |
8c4e4acd | 19 | #include <linux/writeback.h> |
1da177e4 | 20 | |
c988afb5 CH |
21 | static int check_quotactl_permission(struct super_block *sb, int type, int cmd, |
22 | qid_t id) | |
1da177e4 | 23 | { |
c988afb5 CH |
24 | switch (cmd) { |
25 | /* these commands do not require any special privilegues */ | |
26 | case Q_GETFMT: | |
27 | case Q_SYNC: | |
28 | case Q_GETINFO: | |
29 | case Q_XGETQSTAT: | |
af30cb44 | 30 | case Q_XGETQSTATV: |
c988afb5 CH |
31 | case Q_XQUOTASYNC: |
32 | break; | |
33 | /* allow to query information for dquots we "own" */ | |
34 | case Q_GETQUOTA: | |
35 | case Q_XGETQUOTA: | |
74a8a103 EB |
36 | if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) || |
37 | (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id)))) | |
c988afb5 CH |
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 | ||
01a05b33 AV |
48 | static void quota_sync_one(struct super_block *sb, void *arg) |
49 | { | |
50 | if (sb->s_qcop && sb->s_qcop->quota_sync) | |
ceed1723 | 51 | sb->s_qcop->quota_sync(sb, *(int *)arg); |
01a05b33 AV |
52 | } |
53 | ||
6ae09575 | 54 | static int quota_sync_all(int type) |
1da177e4 | 55 | { |
6ae09575 CH |
56 | int ret; |
57 | ||
58 | if (type >= MAXQUOTAS) | |
59 | return -EINVAL; | |
60 | ret = security_quotactl(Q_SYNC, type, 0, NULL); | |
01a05b33 AV |
61 | if (!ret) |
62 | iterate_supers(quota_sync_one, &type); | |
63 | return ret; | |
1da177e4 LT |
64 | } |
65 | ||
c411e5f6 | 66 | static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id, |
f00c9e44 | 67 | struct path *path) |
1da177e4 | 68 | { |
f00c9e44 JK |
69 | 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); | |
c411e5f6 | 76 | } |
1da177e4 | 77 | |
c411e5f6 CH |
78 | static int quota_getfmt(struct super_block *sb, int type, void __user *addr) |
79 | { | |
80 | __u32 fmt; | |
1da177e4 | 81 | |
c411e5f6 CH |
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 | } | |
1da177e4 | 93 | |
c411e5f6 CH |
94 | static int quota_getinfo(struct super_block *sb, int type, void __user *addr) |
95 | { | |
96 | struct if_dqinfo info; | |
97 | int ret; | |
1da177e4 | 98 | |
f450d4fe CH |
99 | if (!sb->s_qcop->get_info) |
100 | return -ENOSYS; | |
c411e5f6 CH |
101 | 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 | } | |
1da177e4 | 106 | |
c411e5f6 CH |
107 | static int quota_setinfo(struct super_block *sb, int type, void __user *addr) |
108 | { | |
109 | struct if_dqinfo info; | |
1da177e4 | 110 | |
c411e5f6 CH |
111 | if (copy_from_user(&info, addr, sizeof(info))) |
112 | return -EFAULT; | |
f450d4fe CH |
113 | if (!sb->s_qcop->set_info) |
114 | return -ENOSYS; | |
c411e5f6 CH |
115 | return sb->s_qcop->set_info(sb, type, &info); |
116 | } | |
117 | ||
b9b2dd36 CH |
118 | static 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 | ||
c411e5f6 CH |
131 | static int quota_getquota(struct super_block *sb, int type, qid_t id, |
132 | void __user *addr) | |
133 | { | |
74a8a103 | 134 | struct kqid qid; |
b9b2dd36 | 135 | struct fs_disk_quota fdq; |
c411e5f6 CH |
136 | struct if_dqblk idq; |
137 | int ret; | |
138 | ||
f450d4fe CH |
139 | if (!sb->s_qcop->get_dqblk) |
140 | return -ENOSYS; | |
74a8a103 EB |
141 | qid = make_kqid(current_user_ns(), type, id); |
142 | if (!qid_valid(qid)) | |
143 | return -EINVAL; | |
144 | ret = sb->s_qcop->get_dqblk(sb, qid, &fdq); | |
c411e5f6 CH |
145 | if (ret) |
146 | return ret; | |
b9b2dd36 | 147 | copy_to_if_dqblk(&idq, &fdq); |
c411e5f6 CH |
148 | if (copy_to_user(addr, &idq, sizeof(idq))) |
149 | return -EFAULT; | |
150 | return 0; | |
151 | } | |
152 | ||
c472b432 CH |
153 | static void copy_from_if_dqblk(struct fs_disk_quota *dst, struct if_dqblk *src) |
154 | { | |
155 | dst->d_blk_hardlimit = src->dqb_bhardlimit; | |
156 | dst->d_blk_softlimit = src->dqb_bsoftlimit; | |
157 | dst->d_bcount = src->dqb_curspace; | |
158 | dst->d_ino_hardlimit = src->dqb_ihardlimit; | |
159 | dst->d_ino_softlimit = src->dqb_isoftlimit; | |
160 | dst->d_icount = src->dqb_curinodes; | |
161 | dst->d_btimer = src->dqb_btime; | |
162 | dst->d_itimer = src->dqb_itime; | |
163 | ||
164 | dst->d_fieldmask = 0; | |
165 | if (src->dqb_valid & QIF_BLIMITS) | |
166 | dst->d_fieldmask |= FS_DQ_BSOFT | FS_DQ_BHARD; | |
167 | if (src->dqb_valid & QIF_SPACE) | |
168 | dst->d_fieldmask |= FS_DQ_BCOUNT; | |
169 | if (src->dqb_valid & QIF_ILIMITS) | |
170 | dst->d_fieldmask |= FS_DQ_ISOFT | FS_DQ_IHARD; | |
171 | if (src->dqb_valid & QIF_INODES) | |
172 | dst->d_fieldmask |= FS_DQ_ICOUNT; | |
173 | if (src->dqb_valid & QIF_BTIME) | |
174 | dst->d_fieldmask |= FS_DQ_BTIMER; | |
175 | if (src->dqb_valid & QIF_ITIME) | |
176 | dst->d_fieldmask |= FS_DQ_ITIMER; | |
177 | } | |
178 | ||
c411e5f6 CH |
179 | static int quota_setquota(struct super_block *sb, int type, qid_t id, |
180 | void __user *addr) | |
181 | { | |
c472b432 | 182 | struct fs_disk_quota fdq; |
c411e5f6 | 183 | struct if_dqblk idq; |
74a8a103 | 184 | struct kqid qid; |
c411e5f6 CH |
185 | |
186 | if (copy_from_user(&idq, addr, sizeof(idq))) | |
187 | return -EFAULT; | |
f450d4fe CH |
188 | if (!sb->s_qcop->set_dqblk) |
189 | return -ENOSYS; | |
74a8a103 EB |
190 | qid = make_kqid(current_user_ns(), type, id); |
191 | if (!qid_valid(qid)) | |
192 | return -EINVAL; | |
c472b432 | 193 | copy_from_if_dqblk(&fdq, &idq); |
74a8a103 | 194 | return sb->s_qcop->set_dqblk(sb, qid, &fdq); |
c411e5f6 CH |
195 | } |
196 | ||
197 | static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr) | |
198 | { | |
199 | __u32 flags; | |
200 | ||
201 | if (copy_from_user(&flags, addr, sizeof(flags))) | |
202 | return -EFAULT; | |
f450d4fe CH |
203 | if (!sb->s_qcop->set_xstate) |
204 | return -ENOSYS; | |
c411e5f6 CH |
205 | return sb->s_qcop->set_xstate(sb, flags, cmd); |
206 | } | |
207 | ||
208 | static int quota_getxstate(struct super_block *sb, void __user *addr) | |
209 | { | |
210 | struct fs_quota_stat fqs; | |
211 | int ret; | |
f450d4fe CH |
212 | |
213 | if (!sb->s_qcop->get_xstate) | |
214 | return -ENOSYS; | |
c411e5f6 CH |
215 | ret = sb->s_qcop->get_xstate(sb, &fqs); |
216 | if (!ret && copy_to_user(addr, &fqs, sizeof(fqs))) | |
217 | return -EFAULT; | |
218 | return ret; | |
219 | } | |
1da177e4 | 220 | |
af30cb44 CS |
221 | static int quota_getxstatev(struct super_block *sb, void __user *addr) |
222 | { | |
223 | struct fs_quota_statv fqs; | |
224 | int ret; | |
225 | ||
226 | if (!sb->s_qcop->get_xstatev) | |
227 | return -ENOSYS; | |
228 | ||
229 | memset(&fqs, 0, sizeof(fqs)); | |
230 | if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */ | |
231 | return -EFAULT; | |
232 | ||
233 | /* If this kernel doesn't support user specified version, fail */ | |
234 | switch (fqs.qs_version) { | |
235 | case FS_QSTATV_VERSION1: | |
236 | break; | |
237 | default: | |
238 | return -EINVAL; | |
239 | } | |
240 | ret = sb->s_qcop->get_xstatev(sb, &fqs); | |
241 | if (!ret && copy_to_user(addr, &fqs, sizeof(fqs))) | |
242 | return -EFAULT; | |
243 | return ret; | |
244 | } | |
245 | ||
c411e5f6 CH |
246 | static int quota_setxquota(struct super_block *sb, int type, qid_t id, |
247 | void __user *addr) | |
248 | { | |
249 | struct fs_disk_quota fdq; | |
74a8a103 | 250 | struct kqid qid; |
c411e5f6 CH |
251 | |
252 | if (copy_from_user(&fdq, addr, sizeof(fdq))) | |
253 | return -EFAULT; | |
c472b432 | 254 | if (!sb->s_qcop->set_dqblk) |
f450d4fe | 255 | return -ENOSYS; |
74a8a103 EB |
256 | qid = make_kqid(current_user_ns(), type, id); |
257 | if (!qid_valid(qid)) | |
258 | return -EINVAL; | |
259 | return sb->s_qcop->set_dqblk(sb, qid, &fdq); | |
c411e5f6 CH |
260 | } |
261 | ||
262 | static int quota_getxquota(struct super_block *sb, int type, qid_t id, | |
263 | void __user *addr) | |
264 | { | |
265 | struct fs_disk_quota fdq; | |
74a8a103 | 266 | struct kqid qid; |
c411e5f6 CH |
267 | int ret; |
268 | ||
b9b2dd36 | 269 | if (!sb->s_qcop->get_dqblk) |
f450d4fe | 270 | return -ENOSYS; |
74a8a103 EB |
271 | qid = make_kqid(current_user_ns(), type, id); |
272 | if (!qid_valid(qid)) | |
273 | return -EINVAL; | |
274 | ret = sb->s_qcop->get_dqblk(sb, qid, &fdq); | |
c411e5f6 CH |
275 | if (!ret && copy_to_user(addr, &fdq, sizeof(fdq))) |
276 | return -EFAULT; | |
277 | return ret; | |
278 | } | |
279 | ||
280 | /* Copy parameters and call proper function */ | |
281 | static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, | |
f00c9e44 | 282 | void __user *addr, struct path *path) |
c411e5f6 | 283 | { |
c988afb5 CH |
284 | int ret; |
285 | ||
286 | if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS)) | |
287 | return -EINVAL; | |
288 | if (!sb->s_qcop) | |
289 | return -ENOSYS; | |
290 | ||
291 | ret = check_quotactl_permission(sb, type, cmd, id); | |
292 | if (ret < 0) | |
293 | return ret; | |
294 | ||
c411e5f6 CH |
295 | switch (cmd) { |
296 | case Q_QUOTAON: | |
f00c9e44 | 297 | return quota_quotaon(sb, type, cmd, id, path); |
c411e5f6 | 298 | case Q_QUOTAOFF: |
f450d4fe CH |
299 | if (!sb->s_qcop->quota_off) |
300 | return -ENOSYS; | |
307ae18a | 301 | return sb->s_qcop->quota_off(sb, type); |
c411e5f6 CH |
302 | case Q_GETFMT: |
303 | return quota_getfmt(sb, type, addr); | |
304 | case Q_GETINFO: | |
305 | return quota_getinfo(sb, type, addr); | |
306 | case Q_SETINFO: | |
307 | return quota_setinfo(sb, type, addr); | |
308 | case Q_GETQUOTA: | |
309 | return quota_getquota(sb, type, id, addr); | |
310 | case Q_SETQUOTA: | |
311 | return quota_setquota(sb, type, id, addr); | |
312 | case Q_SYNC: | |
6ae09575 CH |
313 | if (!sb->s_qcop->quota_sync) |
314 | return -ENOSYS; | |
ceed1723 | 315 | return sb->s_qcop->quota_sync(sb, type); |
c411e5f6 CH |
316 | case Q_XQUOTAON: |
317 | case Q_XQUOTAOFF: | |
318 | case Q_XQUOTARM: | |
319 | return quota_setxstate(sb, cmd, addr); | |
320 | case Q_XGETQSTAT: | |
321 | return quota_getxstate(sb, addr); | |
af30cb44 CS |
322 | case Q_XGETQSTATV: |
323 | return quota_getxstatev(sb, addr); | |
c411e5f6 CH |
324 | case Q_XSETQLIM: |
325 | return quota_setxquota(sb, type, id, addr); | |
326 | case Q_XGETQUOTA: | |
327 | return quota_getxquota(sb, type, id, addr); | |
328 | case Q_XQUOTASYNC: | |
8c4e4acd CH |
329 | if (sb->s_flags & MS_RDONLY) |
330 | return -EROFS; | |
4b217ed9 | 331 | /* XFS quotas are fully coherent now, making this call a noop */ |
8c4e4acd | 332 | return 0; |
c411e5f6 | 333 | default: |
f450d4fe | 334 | return -EINVAL; |
1da177e4 | 335 | } |
1da177e4 LT |
336 | } |
337 | ||
56df1278 LJ |
338 | #ifdef CONFIG_BLOCK |
339 | ||
dcdbed85 JK |
340 | /* Return 1 if 'cmd' will block on frozen filesystem */ |
341 | static int quotactl_cmd_write(int cmd) | |
342 | { | |
343 | switch (cmd) { | |
344 | case Q_GETFMT: | |
345 | case Q_GETINFO: | |
346 | case Q_SYNC: | |
347 | case Q_XGETQSTAT: | |
af30cb44 | 348 | case Q_XGETQSTATV: |
dcdbed85 JK |
349 | case Q_XGETQUOTA: |
350 | case Q_XQUOTASYNC: | |
351 | return 0; | |
352 | } | |
353 | return 1; | |
354 | } | |
355 | ||
56df1278 LJ |
356 | #endif /* CONFIG_BLOCK */ |
357 | ||
9361401e DH |
358 | /* |
359 | * look up a superblock on which quota ops will be performed | |
360 | * - use the name of a block device to find the superblock thereon | |
361 | */ | |
dcdbed85 | 362 | static struct super_block *quotactl_block(const char __user *special, int cmd) |
9361401e DH |
363 | { |
364 | #ifdef CONFIG_BLOCK | |
365 | struct block_device *bdev; | |
366 | struct super_block *sb; | |
91a27b2a | 367 | struct filename *tmp = getname(special); |
9361401e DH |
368 | |
369 | if (IS_ERR(tmp)) | |
e231c2ee | 370 | return ERR_CAST(tmp); |
91a27b2a | 371 | bdev = lookup_bdev(tmp->name); |
9361401e DH |
372 | putname(tmp); |
373 | if (IS_ERR(bdev)) | |
e231c2ee | 374 | return ERR_CAST(bdev); |
dcdbed85 JK |
375 | if (quotactl_cmd_write(cmd)) |
376 | sb = get_super_thawed(bdev); | |
377 | else | |
378 | sb = get_super(bdev); | |
9361401e DH |
379 | bdput(bdev); |
380 | if (!sb) | |
381 | return ERR_PTR(-ENODEV); | |
382 | ||
383 | return sb; | |
384 | #else | |
385 | return ERR_PTR(-ENODEV); | |
386 | #endif | |
387 | } | |
388 | ||
1da177e4 LT |
389 | /* |
390 | * This is the system call interface. This communicates with | |
391 | * the user-level programs. Currently this only supports diskquota | |
392 | * calls. Maybe we need to add the process quotas etc. in the future, | |
393 | * but we probably should use rlimits for that. | |
394 | */ | |
3cdad428 HC |
395 | SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, |
396 | qid_t, id, void __user *, addr) | |
1da177e4 LT |
397 | { |
398 | uint cmds, type; | |
399 | struct super_block *sb = NULL; | |
f00c9e44 | 400 | struct path path, *pathp = NULL; |
1da177e4 LT |
401 | int ret; |
402 | ||
403 | cmds = cmd >> SUBCMDSHIFT; | |
404 | type = cmd & SUBCMDMASK; | |
405 | ||
6ae09575 CH |
406 | /* |
407 | * As a special case Q_SYNC can be called without a specific device. | |
408 | * It will iterate all superblocks that have quota enabled and call | |
409 | * the sync action on each of them. | |
410 | */ | |
411 | if (!special) { | |
412 | if (cmds == Q_SYNC) | |
413 | return quota_sync_all(type); | |
414 | return -ENODEV; | |
1da177e4 LT |
415 | } |
416 | ||
f00c9e44 JK |
417 | /* |
418 | * Path for quotaon has to be resolved before grabbing superblock | |
419 | * because that gets s_umount sem which is also possibly needed by path | |
420 | * resolution (think about autofs) and thus deadlocks could arise. | |
421 | */ | |
422 | if (cmds == Q_QUOTAON) { | |
815d405c | 423 | ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path); |
f00c9e44 JK |
424 | if (ret) |
425 | pathp = ERR_PTR(ret); | |
426 | else | |
427 | pathp = &path; | |
428 | } | |
429 | ||
dcdbed85 | 430 | sb = quotactl_block(special, cmds); |
0aaa6188 JK |
431 | if (IS_ERR(sb)) { |
432 | ret = PTR_ERR(sb); | |
433 | goto out; | |
434 | } | |
6ae09575 | 435 | |
f00c9e44 | 436 | ret = do_quotactl(sb, type, cmds, id, addr, pathp); |
1da177e4 | 437 | |
6ae09575 | 438 | drop_super(sb); |
0aaa6188 | 439 | out: |
f00c9e44 JK |
440 | if (pathp && !IS_ERR(pathp)) |
441 | path_put(pathp); | |
1da177e4 LT |
442 | return ret; |
443 | } |