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> | |
b716395e | 13 | #include <linux/compat.h> |
1da177e4 | 14 | #include <linux/kernel.h> |
1da177e4 LT |
15 | #include <linux/security.h> |
16 | #include <linux/syscalls.h> | |
17 | #include <linux/buffer_head.h> | |
16f7e0fe | 18 | #include <linux/capability.h> |
be586bab | 19 | #include <linux/quotaops.h> |
b716395e | 20 | #include <linux/types.h> |
86e931a3 SW |
21 | #include <net/netlink.h> |
22 | #include <net/genetlink.h> | |
1da177e4 | 23 | |
c988afb5 CH |
24 | static int check_quotactl_permission(struct super_block *sb, int type, int cmd, |
25 | qid_t id) | |
1da177e4 | 26 | { |
c988afb5 CH |
27 | switch (cmd) { |
28 | /* these commands do not require any special privilegues */ | |
29 | case Q_GETFMT: | |
30 | case Q_SYNC: | |
31 | case Q_GETINFO: | |
32 | case Q_XGETQSTAT: | |
33 | case Q_XQUOTASYNC: | |
34 | break; | |
35 | /* allow to query information for dquots we "own" */ | |
36 | case Q_GETQUOTA: | |
37 | case Q_XGETQUOTA: | |
38 | if ((type == USRQUOTA && current_euid() == id) || | |
39 | (type == GRPQUOTA && in_egroup_p(id))) | |
40 | break; | |
41 | /*FALLTHROUGH*/ | |
42 | default: | |
1da177e4 LT |
43 | if (!capable(CAP_SYS_ADMIN)) |
44 | return -EPERM; | |
45 | } | |
46 | ||
c988afb5 | 47 | return security_quotactl(cmd, type, id, sb); |
1da177e4 LT |
48 | } |
49 | ||
850b201b CH |
50 | #ifdef CONFIG_QUOTA |
51 | void sync_quota_sb(struct super_block *sb, int type) | |
1da177e4 LT |
52 | { |
53 | int cnt; | |
1da177e4 | 54 | |
850b201b CH |
55 | if (!sb->s_qcop->quota_sync) |
56 | return; | |
57 | ||
1da177e4 | 58 | sb->s_qcop->quota_sync(sb, type); |
ca785ec6 JK |
59 | |
60 | if (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE) | |
61 | return; | |
1da177e4 LT |
62 | /* This is not very clever (and fast) but currently I don't know about |
63 | * any other simple way of getting quota data to disk and we must get | |
64 | * them there for userspace to be visible... */ | |
65 | if (sb->s_op->sync_fs) | |
66 | sb->s_op->sync_fs(sb, 1); | |
67 | sync_blockdev(sb->s_bdev); | |
68 | ||
7925409e JK |
69 | /* |
70 | * Now when everything is written we can discard the pagecache so | |
71 | * that userspace sees the changes. | |
72 | */ | |
d3be915f | 73 | mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); |
1da177e4 | 74 | for (cnt = 0; cnt < MAXQUOTAS; cnt++) { |
1da177e4 LT |
75 | if (type != -1 && cnt != type) |
76 | continue; | |
f55abc0f | 77 | if (!sb_has_quota_active(sb, cnt)) |
1da177e4 | 78 | continue; |
268157ba JK |
79 | mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, |
80 | I_MUTEX_QUOTA); | |
7925409e JK |
81 | truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0); |
82 | mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex); | |
1da177e4 | 83 | } |
d3be915f | 84 | mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); |
1da177e4 | 85 | } |
850b201b | 86 | #endif |
1da177e4 | 87 | |
6ae09575 | 88 | static int quota_sync_all(int type) |
1da177e4 | 89 | { |
850b201b | 90 | struct super_block *sb; |
02a55ca8 | 91 | int cnt; |
6ae09575 CH |
92 | int ret; |
93 | ||
94 | if (type >= MAXQUOTAS) | |
95 | return -EINVAL; | |
96 | ret = security_quotactl(Q_SYNC, type, 0, NULL); | |
97 | if (ret) | |
98 | return ret; | |
618f0636 | 99 | |
618f0636 KK |
100 | spin_lock(&sb_lock); |
101 | restart: | |
102 | list_for_each_entry(sb, &super_blocks, s_list) { | |
268157ba JK |
103 | /* This test just improves performance so it needn't be |
104 | * reliable... */ | |
02a55ca8 JK |
105 | for (cnt = 0; cnt < MAXQUOTAS; cnt++) { |
106 | if (type != -1 && type != cnt) | |
107 | continue; | |
f55abc0f | 108 | if (!sb_has_quota_active(sb, cnt)) |
02a55ca8 JK |
109 | continue; |
110 | if (!info_dirty(&sb_dqopt(sb)->info[cnt]) && | |
268157ba | 111 | list_empty(&sb_dqopt(sb)->info[cnt].dqi_dirty_list)) |
02a55ca8 JK |
112 | continue; |
113 | break; | |
114 | } | |
115 | if (cnt == MAXQUOTAS) | |
618f0636 KK |
116 | continue; |
117 | sb->s_count++; | |
118 | spin_unlock(&sb_lock); | |
119 | down_read(&sb->s_umount); | |
850b201b CH |
120 | if (sb->s_root) |
121 | sync_quota_sb(sb, type); | |
618f0636 KK |
122 | up_read(&sb->s_umount); |
123 | spin_lock(&sb_lock); | |
124 | if (__put_super_and_need_restart(sb)) | |
125 | goto restart; | |
1da177e4 | 126 | } |
618f0636 | 127 | spin_unlock(&sb_lock); |
6ae09575 CH |
128 | |
129 | return 0; | |
1da177e4 LT |
130 | } |
131 | ||
c411e5f6 CH |
132 | static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id, |
133 | void __user *addr) | |
1da177e4 | 134 | { |
c411e5f6 | 135 | char *pathname; |
f450d4fe | 136 | int ret = -ENOSYS; |
1da177e4 | 137 | |
c411e5f6 CH |
138 | pathname = getname(addr); |
139 | if (IS_ERR(pathname)) | |
140 | return PTR_ERR(pathname); | |
f450d4fe CH |
141 | if (sb->s_qcop->quota_on) |
142 | ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0); | |
c411e5f6 CH |
143 | putname(pathname); |
144 | return ret; | |
145 | } | |
1da177e4 | 146 | |
c411e5f6 CH |
147 | static int quota_getfmt(struct super_block *sb, int type, void __user *addr) |
148 | { | |
149 | __u32 fmt; | |
1da177e4 | 150 | |
c411e5f6 CH |
151 | down_read(&sb_dqopt(sb)->dqptr_sem); |
152 | if (!sb_has_quota_active(sb, type)) { | |
153 | up_read(&sb_dqopt(sb)->dqptr_sem); | |
154 | return -ESRCH; | |
155 | } | |
156 | fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id; | |
157 | up_read(&sb_dqopt(sb)->dqptr_sem); | |
158 | if (copy_to_user(addr, &fmt, sizeof(fmt))) | |
159 | return -EFAULT; | |
160 | return 0; | |
161 | } | |
1da177e4 | 162 | |
c411e5f6 CH |
163 | static int quota_getinfo(struct super_block *sb, int type, void __user *addr) |
164 | { | |
165 | struct if_dqinfo info; | |
166 | int ret; | |
1da177e4 | 167 | |
f450d4fe CH |
168 | if (!sb_has_quota_active(sb, type)) |
169 | return -ESRCH; | |
170 | if (!sb->s_qcop->get_info) | |
171 | return -ENOSYS; | |
c411e5f6 CH |
172 | ret = sb->s_qcop->get_info(sb, type, &info); |
173 | if (!ret && copy_to_user(addr, &info, sizeof(info))) | |
174 | return -EFAULT; | |
175 | return ret; | |
176 | } | |
1da177e4 | 177 | |
c411e5f6 CH |
178 | static int quota_setinfo(struct super_block *sb, int type, void __user *addr) |
179 | { | |
180 | struct if_dqinfo info; | |
1da177e4 | 181 | |
c411e5f6 CH |
182 | if (copy_from_user(&info, addr, sizeof(info))) |
183 | return -EFAULT; | |
f450d4fe CH |
184 | if (!sb_has_quota_active(sb, type)) |
185 | return -ESRCH; | |
186 | if (!sb->s_qcop->set_info) | |
187 | return -ENOSYS; | |
c411e5f6 CH |
188 | return sb->s_qcop->set_info(sb, type, &info); |
189 | } | |
190 | ||
191 | static int quota_getquota(struct super_block *sb, int type, qid_t id, | |
192 | void __user *addr) | |
193 | { | |
194 | struct if_dqblk idq; | |
195 | int ret; | |
196 | ||
f450d4fe CH |
197 | if (!sb_has_quota_active(sb, type)) |
198 | return -ESRCH; | |
199 | if (!sb->s_qcop->get_dqblk) | |
200 | return -ENOSYS; | |
c411e5f6 CH |
201 | ret = sb->s_qcop->get_dqblk(sb, type, id, &idq); |
202 | if (ret) | |
203 | return ret; | |
204 | if (copy_to_user(addr, &idq, sizeof(idq))) | |
205 | return -EFAULT; | |
206 | return 0; | |
207 | } | |
208 | ||
209 | static int quota_setquota(struct super_block *sb, int type, qid_t id, | |
210 | void __user *addr) | |
211 | { | |
212 | struct if_dqblk idq; | |
213 | ||
214 | if (copy_from_user(&idq, addr, sizeof(idq))) | |
215 | return -EFAULT; | |
f450d4fe CH |
216 | if (!sb_has_quota_active(sb, type)) |
217 | return -ESRCH; | |
218 | if (!sb->s_qcop->set_dqblk) | |
219 | return -ENOSYS; | |
c411e5f6 CH |
220 | return sb->s_qcop->set_dqblk(sb, type, id, &idq); |
221 | } | |
222 | ||
223 | static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr) | |
224 | { | |
225 | __u32 flags; | |
226 | ||
227 | if (copy_from_user(&flags, addr, sizeof(flags))) | |
228 | return -EFAULT; | |
f450d4fe CH |
229 | if (!sb->s_qcop->set_xstate) |
230 | return -ENOSYS; | |
c411e5f6 CH |
231 | return sb->s_qcop->set_xstate(sb, flags, cmd); |
232 | } | |
233 | ||
234 | static int quota_getxstate(struct super_block *sb, void __user *addr) | |
235 | { | |
236 | struct fs_quota_stat fqs; | |
237 | int ret; | |
f450d4fe CH |
238 | |
239 | if (!sb->s_qcop->get_xstate) | |
240 | return -ENOSYS; | |
c411e5f6 CH |
241 | ret = sb->s_qcop->get_xstate(sb, &fqs); |
242 | if (!ret && copy_to_user(addr, &fqs, sizeof(fqs))) | |
243 | return -EFAULT; | |
244 | return ret; | |
245 | } | |
1da177e4 | 246 | |
c411e5f6 CH |
247 | static int quota_setxquota(struct super_block *sb, int type, qid_t id, |
248 | void __user *addr) | |
249 | { | |
250 | struct fs_disk_quota fdq; | |
251 | ||
252 | if (copy_from_user(&fdq, addr, sizeof(fdq))) | |
253 | return -EFAULT; | |
f450d4fe CH |
254 | if (!sb->s_qcop->set_xquota) |
255 | return -ENOSYS; | |
c411e5f6 CH |
256 | return sb->s_qcop->set_xquota(sb, type, id, &fdq); |
257 | } | |
258 | ||
259 | static int quota_getxquota(struct super_block *sb, int type, qid_t id, | |
260 | void __user *addr) | |
261 | { | |
262 | struct fs_disk_quota fdq; | |
263 | int ret; | |
264 | ||
f450d4fe CH |
265 | if (!sb->s_qcop->get_xquota) |
266 | return -ENOSYS; | |
c411e5f6 CH |
267 | ret = sb->s_qcop->get_xquota(sb, type, id, &fdq); |
268 | if (!ret && copy_to_user(addr, &fdq, sizeof(fdq))) | |
269 | return -EFAULT; | |
270 | return ret; | |
271 | } | |
272 | ||
273 | /* Copy parameters and call proper function */ | |
274 | static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, | |
275 | void __user *addr) | |
276 | { | |
c988afb5 CH |
277 | int ret; |
278 | ||
279 | if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS)) | |
280 | return -EINVAL; | |
281 | if (!sb->s_qcop) | |
282 | return -ENOSYS; | |
283 | ||
284 | ret = check_quotactl_permission(sb, type, cmd, id); | |
285 | if (ret < 0) | |
286 | return ret; | |
287 | ||
c411e5f6 CH |
288 | switch (cmd) { |
289 | case Q_QUOTAON: | |
290 | return quota_quotaon(sb, type, cmd, id, addr); | |
291 | case Q_QUOTAOFF: | |
f450d4fe CH |
292 | if (!sb->s_qcop->quota_off) |
293 | return -ENOSYS; | |
c411e5f6 CH |
294 | return sb->s_qcop->quota_off(sb, type, 0); |
295 | case Q_GETFMT: | |
296 | return quota_getfmt(sb, type, addr); | |
297 | case Q_GETINFO: | |
298 | return quota_getinfo(sb, type, addr); | |
299 | case Q_SETINFO: | |
300 | return quota_setinfo(sb, type, addr); | |
301 | case Q_GETQUOTA: | |
302 | return quota_getquota(sb, type, id, addr); | |
303 | case Q_SETQUOTA: | |
304 | return quota_setquota(sb, type, id, addr); | |
305 | case Q_SYNC: | |
6ae09575 CH |
306 | if (!sb->s_qcop->quota_sync) |
307 | return -ENOSYS; | |
308 | sync_quota_sb(sb, type); | |
c411e5f6 CH |
309 | return 0; |
310 | case Q_XQUOTAON: | |
311 | case Q_XQUOTAOFF: | |
312 | case Q_XQUOTARM: | |
313 | return quota_setxstate(sb, cmd, addr); | |
314 | case Q_XGETQSTAT: | |
315 | return quota_getxstate(sb, addr); | |
316 | case Q_XSETQLIM: | |
317 | return quota_setxquota(sb, type, id, addr); | |
318 | case Q_XGETQUOTA: | |
319 | return quota_getxquota(sb, type, id, addr); | |
320 | case Q_XQUOTASYNC: | |
f450d4fe CH |
321 | if (!sb->s_qcop->quota_sync) |
322 | return -ENOSYS; | |
c411e5f6 | 323 | return sb->s_qcop->quota_sync(sb, type); |
c411e5f6 | 324 | default: |
f450d4fe | 325 | return -EINVAL; |
1da177e4 | 326 | } |
1da177e4 LT |
327 | } |
328 | ||
9361401e DH |
329 | /* |
330 | * look up a superblock on which quota ops will be performed | |
331 | * - use the name of a block device to find the superblock thereon | |
332 | */ | |
7a2435d8 | 333 | static struct super_block *quotactl_block(const char __user *special) |
9361401e DH |
334 | { |
335 | #ifdef CONFIG_BLOCK | |
336 | struct block_device *bdev; | |
337 | struct super_block *sb; | |
338 | char *tmp = getname(special); | |
339 | ||
340 | if (IS_ERR(tmp)) | |
e231c2ee | 341 | return ERR_CAST(tmp); |
9361401e DH |
342 | bdev = lookup_bdev(tmp); |
343 | putname(tmp); | |
344 | if (IS_ERR(bdev)) | |
e231c2ee | 345 | return ERR_CAST(bdev); |
9361401e DH |
346 | sb = get_super(bdev); |
347 | bdput(bdev); | |
348 | if (!sb) | |
349 | return ERR_PTR(-ENODEV); | |
350 | ||
351 | return sb; | |
352 | #else | |
353 | return ERR_PTR(-ENODEV); | |
354 | #endif | |
355 | } | |
356 | ||
1da177e4 LT |
357 | /* |
358 | * This is the system call interface. This communicates with | |
359 | * the user-level programs. Currently this only supports diskquota | |
360 | * calls. Maybe we need to add the process quotas etc. in the future, | |
361 | * but we probably should use rlimits for that. | |
362 | */ | |
3cdad428 HC |
363 | SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, |
364 | qid_t, id, void __user *, addr) | |
1da177e4 LT |
365 | { |
366 | uint cmds, type; | |
367 | struct super_block *sb = NULL; | |
1da177e4 LT |
368 | int ret; |
369 | ||
370 | cmds = cmd >> SUBCMDSHIFT; | |
371 | type = cmd & SUBCMDMASK; | |
372 | ||
6ae09575 CH |
373 | /* |
374 | * As a special case Q_SYNC can be called without a specific device. | |
375 | * It will iterate all superblocks that have quota enabled and call | |
376 | * the sync action on each of them. | |
377 | */ | |
378 | if (!special) { | |
379 | if (cmds == Q_SYNC) | |
380 | return quota_sync_all(type); | |
381 | return -ENODEV; | |
1da177e4 LT |
382 | } |
383 | ||
6ae09575 CH |
384 | sb = quotactl_block(special); |
385 | if (IS_ERR(sb)) | |
386 | return PTR_ERR(sb); | |
387 | ||
c988afb5 | 388 | ret = do_quotactl(sb, type, cmds, id, addr); |
1da177e4 | 389 | |
6ae09575 | 390 | drop_super(sb); |
1da177e4 LT |
391 | return ret; |
392 | } | |
b716395e | 393 | |
7a6c8135 | 394 | #if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT) |
b716395e VT |
395 | /* |
396 | * This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64) | |
397 | * and is necessary due to alignment problems. | |
398 | */ | |
399 | struct compat_if_dqblk { | |
400 | compat_u64 dqb_bhardlimit; | |
401 | compat_u64 dqb_bsoftlimit; | |
402 | compat_u64 dqb_curspace; | |
403 | compat_u64 dqb_ihardlimit; | |
404 | compat_u64 dqb_isoftlimit; | |
405 | compat_u64 dqb_curinodes; | |
406 | compat_u64 dqb_btime; | |
407 | compat_u64 dqb_itime; | |
408 | compat_uint_t dqb_valid; | |
409 | }; | |
410 | ||
411 | /* XFS structures */ | |
412 | struct compat_fs_qfilestat { | |
413 | compat_u64 dqb_bhardlimit; | |
414 | compat_u64 qfs_nblks; | |
415 | compat_uint_t qfs_nextents; | |
416 | }; | |
417 | ||
418 | struct compat_fs_quota_stat { | |
419 | __s8 qs_version; | |
420 | __u16 qs_flags; | |
421 | __s8 qs_pad; | |
422 | struct compat_fs_qfilestat qs_uquota; | |
423 | struct compat_fs_qfilestat qs_gquota; | |
424 | compat_uint_t qs_incoredqs; | |
425 | compat_int_t qs_btimelimit; | |
426 | compat_int_t qs_itimelimit; | |
427 | compat_int_t qs_rtbtimelimit; | |
428 | __u16 qs_bwarnlimit; | |
429 | __u16 qs_iwarnlimit; | |
430 | }; | |
431 | ||
432 | asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special, | |
433 | qid_t id, void __user *addr) | |
434 | { | |
435 | unsigned int cmds; | |
436 | struct if_dqblk __user *dqblk; | |
437 | struct compat_if_dqblk __user *compat_dqblk; | |
438 | struct fs_quota_stat __user *fsqstat; | |
439 | struct compat_fs_quota_stat __user *compat_fsqstat; | |
440 | compat_uint_t data; | |
441 | u16 xdata; | |
442 | long ret; | |
443 | ||
444 | cmds = cmd >> SUBCMDSHIFT; | |
445 | ||
446 | switch (cmds) { | |
447 | case Q_GETQUOTA: | |
448 | dqblk = compat_alloc_user_space(sizeof(struct if_dqblk)); | |
449 | compat_dqblk = addr; | |
450 | ret = sys_quotactl(cmd, special, id, dqblk); | |
451 | if (ret) | |
452 | break; | |
453 | if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) || | |
454 | get_user(data, &dqblk->dqb_valid) || | |
455 | put_user(data, &compat_dqblk->dqb_valid)) | |
456 | ret = -EFAULT; | |
457 | break; | |
458 | case Q_SETQUOTA: | |
459 | dqblk = compat_alloc_user_space(sizeof(struct if_dqblk)); | |
460 | compat_dqblk = addr; | |
461 | ret = -EFAULT; | |
462 | if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) || | |
463 | get_user(data, &compat_dqblk->dqb_valid) || | |
464 | put_user(data, &dqblk->dqb_valid)) | |
465 | break; | |
466 | ret = sys_quotactl(cmd, special, id, dqblk); | |
467 | break; | |
468 | case Q_XGETQSTAT: | |
469 | fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat)); | |
470 | compat_fsqstat = addr; | |
471 | ret = sys_quotactl(cmd, special, id, fsqstat); | |
472 | if (ret) | |
473 | break; | |
474 | ret = -EFAULT; | |
475 | /* Copying qs_version, qs_flags, qs_pad */ | |
476 | if (copy_in_user(compat_fsqstat, fsqstat, | |
477 | offsetof(struct compat_fs_quota_stat, qs_uquota))) | |
478 | break; | |
479 | /* Copying qs_uquota */ | |
480 | if (copy_in_user(&compat_fsqstat->qs_uquota, | |
481 | &fsqstat->qs_uquota, | |
482 | sizeof(compat_fsqstat->qs_uquota)) || | |
483 | get_user(data, &fsqstat->qs_uquota.qfs_nextents) || | |
484 | put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents)) | |
485 | break; | |
486 | /* Copying qs_gquota */ | |
487 | if (copy_in_user(&compat_fsqstat->qs_gquota, | |
488 | &fsqstat->qs_gquota, | |
489 | sizeof(compat_fsqstat->qs_gquota)) || | |
490 | get_user(data, &fsqstat->qs_gquota.qfs_nextents) || | |
491 | put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents)) | |
492 | break; | |
493 | /* Copying the rest */ | |
494 | if (copy_in_user(&compat_fsqstat->qs_incoredqs, | |
495 | &fsqstat->qs_incoredqs, | |
496 | sizeof(struct compat_fs_quota_stat) - | |
497 | offsetof(struct compat_fs_quota_stat, qs_incoredqs)) || | |
498 | get_user(xdata, &fsqstat->qs_iwarnlimit) || | |
499 | put_user(xdata, &compat_fsqstat->qs_iwarnlimit)) | |
500 | break; | |
501 | ret = 0; | |
502 | break; | |
503 | default: | |
504 | ret = sys_quotactl(cmd, special, id, addr); | |
505 | } | |
506 | return ret; | |
507 | } | |
508 | #endif | |
86e931a3 SW |
509 | |
510 | ||
511 | #ifdef CONFIG_QUOTA_NETLINK_INTERFACE | |
512 | ||
513 | /* Netlink family structure for quota */ | |
514 | static struct genl_family quota_genl_family = { | |
515 | .id = GENL_ID_GENERATE, | |
516 | .hdrsize = 0, | |
517 | .name = "VFS_DQUOT", | |
518 | .version = 1, | |
519 | .maxattr = QUOTA_NL_A_MAX, | |
520 | }; | |
521 | ||
522 | /** | |
523 | * quota_send_warning - Send warning to userspace about exceeded quota | |
524 | * @type: The quota type: USRQQUOTA, GRPQUOTA,... | |
525 | * @id: The user or group id of the quota that was exceeded | |
526 | * @dev: The device on which the fs is mounted (sb->s_dev) | |
527 | * @warntype: The type of the warning: QUOTA_NL_... | |
528 | * | |
529 | * This can be used by filesystems (including those which don't use | |
530 | * dquot) to send a message to userspace relating to quota limits. | |
531 | * | |
532 | */ | |
533 | ||
534 | void quota_send_warning(short type, unsigned int id, dev_t dev, | |
535 | const char warntype) | |
536 | { | |
537 | static atomic_t seq; | |
538 | struct sk_buff *skb; | |
539 | void *msg_head; | |
540 | int ret; | |
541 | int msg_size = 4 * nla_total_size(sizeof(u32)) + | |
542 | 2 * nla_total_size(sizeof(u64)); | |
543 | ||
544 | /* We have to allocate using GFP_NOFS as we are called from a | |
545 | * filesystem performing write and thus further recursion into | |
546 | * the fs to free some data could cause deadlocks. */ | |
547 | skb = genlmsg_new(msg_size, GFP_NOFS); | |
548 | if (!skb) { | |
549 | printk(KERN_ERR | |
550 | "VFS: Not enough memory to send quota warning.\n"); | |
551 | return; | |
552 | } | |
553 | msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq), | |
554 | "a_genl_family, 0, QUOTA_NL_C_WARNING); | |
555 | if (!msg_head) { | |
556 | printk(KERN_ERR | |
557 | "VFS: Cannot store netlink header in quota warning.\n"); | |
558 | goto err_out; | |
559 | } | |
560 | ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type); | |
561 | if (ret) | |
562 | goto attr_err_out; | |
563 | ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id); | |
564 | if (ret) | |
565 | goto attr_err_out; | |
566 | ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype); | |
567 | if (ret) | |
568 | goto attr_err_out; | |
569 | ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev)); | |
570 | if (ret) | |
571 | goto attr_err_out; | |
572 | ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev)); | |
573 | if (ret) | |
574 | goto attr_err_out; | |
575 | ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid()); | |
576 | if (ret) | |
577 | goto attr_err_out; | |
578 | genlmsg_end(skb, msg_head); | |
579 | ||
580 | genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS); | |
581 | return; | |
582 | attr_err_out: | |
583 | printk(KERN_ERR "VFS: Not enough space to compose quota message!\n"); | |
584 | err_out: | |
585 | kfree_skb(skb); | |
586 | } | |
587 | EXPORT_SYMBOL(quota_send_warning); | |
588 | ||
589 | static int __init quota_init(void) | |
590 | { | |
591 | if (genl_register_family("a_genl_family) != 0) | |
592 | printk(KERN_ERR | |
593 | "VFS: Failed to create quota netlink interface.\n"); | |
594 | return 0; | |
595 | }; | |
596 | ||
597 | module_init(quota_init); | |
598 | #endif | |
599 |