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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> | |
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 LT |
23 | |
24 | /* Check validity of generic quotactl commands */ | |
268157ba JK |
25 | static int generic_quotactl_valid(struct super_block *sb, int type, int cmd, |
26 | qid_t id) | |
1da177e4 LT |
27 | { |
28 | if (type >= MAXQUOTAS) | |
29 | return -EINVAL; | |
30 | if (!sb && cmd != Q_SYNC) | |
31 | return -ENODEV; | |
32 | /* Is operation supported? */ | |
33 | if (sb && !sb->s_qcop) | |
34 | return -ENOSYS; | |
35 | ||
36 | switch (cmd) { | |
37 | case Q_GETFMT: | |
38 | break; | |
39 | case Q_QUOTAON: | |
40 | if (!sb->s_qcop->quota_on) | |
41 | return -ENOSYS; | |
42 | break; | |
43 | case Q_QUOTAOFF: | |
44 | if (!sb->s_qcop->quota_off) | |
45 | return -ENOSYS; | |
46 | break; | |
47 | case Q_SETINFO: | |
48 | if (!sb->s_qcop->set_info) | |
49 | return -ENOSYS; | |
50 | break; | |
51 | case Q_GETINFO: | |
52 | if (!sb->s_qcop->get_info) | |
53 | return -ENOSYS; | |
54 | break; | |
55 | case Q_SETQUOTA: | |
56 | if (!sb->s_qcop->set_dqblk) | |
57 | return -ENOSYS; | |
58 | break; | |
59 | case Q_GETQUOTA: | |
60 | if (!sb->s_qcop->get_dqblk) | |
61 | return -ENOSYS; | |
62 | break; | |
63 | case Q_SYNC: | |
64 | if (sb && !sb->s_qcop->quota_sync) | |
65 | return -ENOSYS; | |
66 | break; | |
67 | default: | |
68 | return -EINVAL; | |
69 | } | |
70 | ||
71 | /* Is quota turned on for commands which need it? */ | |
72 | switch (cmd) { | |
73 | case Q_GETFMT: | |
74 | case Q_GETINFO: | |
1da177e4 LT |
75 | case Q_SETINFO: |
76 | case Q_SETQUOTA: | |
77 | case Q_GETQUOTA: | |
268157ba JK |
78 | /* This is just an informative test so we are satisfied |
79 | * without the lock */ | |
f55abc0f | 80 | if (!sb_has_quota_active(sb, type)) |
1da177e4 LT |
81 | return -ESRCH; |
82 | } | |
83 | ||
84 | /* Check privileges */ | |
85 | if (cmd == Q_GETQUOTA) { | |
da9592ed | 86 | if (((type == USRQUOTA && current_euid() != id) || |
1da177e4 LT |
87 | (type == GRPQUOTA && !in_egroup_p(id))) && |
88 | !capable(CAP_SYS_ADMIN)) | |
89 | return -EPERM; | |
90 | } | |
91 | else if (cmd != Q_GETFMT && cmd != Q_SYNC && cmd != Q_GETINFO) | |
92 | if (!capable(CAP_SYS_ADMIN)) | |
93 | return -EPERM; | |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
98 | /* Check validity of XFS Quota Manager commands */ | |
268157ba JK |
99 | static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd, |
100 | qid_t id) | |
1da177e4 LT |
101 | { |
102 | if (type >= XQM_MAXQUOTAS) | |
103 | return -EINVAL; | |
104 | if (!sb) | |
105 | return -ENODEV; | |
106 | if (!sb->s_qcop) | |
107 | return -ENOSYS; | |
108 | ||
109 | switch (cmd) { | |
110 | case Q_XQUOTAON: | |
111 | case Q_XQUOTAOFF: | |
112 | case Q_XQUOTARM: | |
113 | if (!sb->s_qcop->set_xstate) | |
114 | return -ENOSYS; | |
115 | break; | |
116 | case Q_XGETQSTAT: | |
117 | if (!sb->s_qcop->get_xstate) | |
118 | return -ENOSYS; | |
119 | break; | |
120 | case Q_XSETQLIM: | |
121 | if (!sb->s_qcop->set_xquota) | |
122 | return -ENOSYS; | |
123 | break; | |
124 | case Q_XGETQUOTA: | |
125 | if (!sb->s_qcop->get_xquota) | |
126 | return -ENOSYS; | |
127 | break; | |
de69e5f4 NS |
128 | case Q_XQUOTASYNC: |
129 | if (!sb->s_qcop->quota_sync) | |
130 | return -ENOSYS; | |
131 | break; | |
1da177e4 LT |
132 | default: |
133 | return -EINVAL; | |
134 | } | |
135 | ||
136 | /* Check privileges */ | |
137 | if (cmd == Q_XGETQUOTA) { | |
da9592ed | 138 | if (((type == XQM_USRQUOTA && current_euid() != id) || |
1da177e4 LT |
139 | (type == XQM_GRPQUOTA && !in_egroup_p(id))) && |
140 | !capable(CAP_SYS_ADMIN)) | |
141 | return -EPERM; | |
de69e5f4 | 142 | } else if (cmd != Q_XGETQSTAT && cmd != Q_XQUOTASYNC) { |
1da177e4 LT |
143 | if (!capable(CAP_SYS_ADMIN)) |
144 | return -EPERM; | |
145 | } | |
146 | ||
147 | return 0; | |
148 | } | |
149 | ||
268157ba JK |
150 | static int check_quotactl_valid(struct super_block *sb, int type, int cmd, |
151 | qid_t id) | |
1da177e4 LT |
152 | { |
153 | int error; | |
154 | ||
155 | if (XQM_COMMAND(cmd)) | |
156 | error = xqm_quotactl_valid(sb, type, cmd, id); | |
157 | else | |
158 | error = generic_quotactl_valid(sb, type, cmd, id); | |
159 | if (!error) | |
160 | error = security_quotactl(cmd, type, id, sb); | |
161 | return error; | |
162 | } | |
163 | ||
850b201b CH |
164 | #ifdef CONFIG_QUOTA |
165 | void sync_quota_sb(struct super_block *sb, int type) | |
1da177e4 LT |
166 | { |
167 | int cnt; | |
1da177e4 | 168 | |
850b201b CH |
169 | if (!sb->s_qcop->quota_sync) |
170 | return; | |
171 | ||
1da177e4 | 172 | sb->s_qcop->quota_sync(sb, type); |
ca785ec6 JK |
173 | |
174 | if (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE) | |
175 | return; | |
1da177e4 LT |
176 | /* This is not very clever (and fast) but currently I don't know about |
177 | * any other simple way of getting quota data to disk and we must get | |
178 | * them there for userspace to be visible... */ | |
179 | if (sb->s_op->sync_fs) | |
180 | sb->s_op->sync_fs(sb, 1); | |
181 | sync_blockdev(sb->s_bdev); | |
182 | ||
7925409e JK |
183 | /* |
184 | * Now when everything is written we can discard the pagecache so | |
185 | * that userspace sees the changes. | |
186 | */ | |
d3be915f | 187 | mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); |
1da177e4 | 188 | for (cnt = 0; cnt < MAXQUOTAS; cnt++) { |
1da177e4 LT |
189 | if (type != -1 && cnt != type) |
190 | continue; | |
f55abc0f | 191 | if (!sb_has_quota_active(sb, cnt)) |
1da177e4 | 192 | continue; |
268157ba JK |
193 | mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, |
194 | I_MUTEX_QUOTA); | |
7925409e JK |
195 | truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0); |
196 | mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex); | |
1da177e4 | 197 | } |
d3be915f | 198 | mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); |
1da177e4 | 199 | } |
850b201b | 200 | #endif |
1da177e4 | 201 | |
850b201b | 202 | static void sync_dquots(int type) |
1da177e4 | 203 | { |
850b201b | 204 | struct super_block *sb; |
02a55ca8 | 205 | int cnt; |
618f0636 | 206 | |
618f0636 KK |
207 | spin_lock(&sb_lock); |
208 | restart: | |
209 | list_for_each_entry(sb, &super_blocks, s_list) { | |
268157ba JK |
210 | /* This test just improves performance so it needn't be |
211 | * reliable... */ | |
02a55ca8 JK |
212 | for (cnt = 0; cnt < MAXQUOTAS; cnt++) { |
213 | if (type != -1 && type != cnt) | |
214 | continue; | |
f55abc0f | 215 | if (!sb_has_quota_active(sb, cnt)) |
02a55ca8 JK |
216 | continue; |
217 | if (!info_dirty(&sb_dqopt(sb)->info[cnt]) && | |
268157ba | 218 | list_empty(&sb_dqopt(sb)->info[cnt].dqi_dirty_list)) |
02a55ca8 JK |
219 | continue; |
220 | break; | |
221 | } | |
222 | if (cnt == MAXQUOTAS) | |
618f0636 KK |
223 | continue; |
224 | sb->s_count++; | |
225 | spin_unlock(&sb_lock); | |
226 | down_read(&sb->s_umount); | |
850b201b CH |
227 | if (sb->s_root) |
228 | sync_quota_sb(sb, type); | |
618f0636 KK |
229 | up_read(&sb->s_umount); |
230 | spin_lock(&sb_lock); | |
231 | if (__put_super_and_need_restart(sb)) | |
232 | goto restart; | |
1da177e4 | 233 | } |
618f0636 | 234 | spin_unlock(&sb_lock); |
1da177e4 LT |
235 | } |
236 | ||
237 | /* Copy parameters and call proper function */ | |
268157ba JK |
238 | static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, |
239 | void __user *addr) | |
1da177e4 LT |
240 | { |
241 | int ret; | |
242 | ||
243 | switch (cmd) { | |
244 | case Q_QUOTAON: { | |
245 | char *pathname; | |
246 | ||
268157ba JK |
247 | pathname = getname(addr); |
248 | if (IS_ERR(pathname)) | |
1da177e4 | 249 | return PTR_ERR(pathname); |
0ff5af83 | 250 | ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0); |
1da177e4 LT |
251 | putname(pathname); |
252 | return ret; | |
253 | } | |
254 | case Q_QUOTAOFF: | |
0ff5af83 | 255 | return sb->s_qcop->quota_off(sb, type, 0); |
1da177e4 LT |
256 | |
257 | case Q_GETFMT: { | |
258 | __u32 fmt; | |
259 | ||
260 | down_read(&sb_dqopt(sb)->dqptr_sem); | |
f55abc0f | 261 | if (!sb_has_quota_active(sb, type)) { |
1da177e4 LT |
262 | up_read(&sb_dqopt(sb)->dqptr_sem); |
263 | return -ESRCH; | |
264 | } | |
265 | fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id; | |
266 | up_read(&sb_dqopt(sb)->dqptr_sem); | |
267 | if (copy_to_user(addr, &fmt, sizeof(fmt))) | |
268 | return -EFAULT; | |
269 | return 0; | |
270 | } | |
271 | case Q_GETINFO: { | |
272 | struct if_dqinfo info; | |
273 | ||
268157ba JK |
274 | ret = sb->s_qcop->get_info(sb, type, &info); |
275 | if (ret) | |
1da177e4 LT |
276 | return ret; |
277 | if (copy_to_user(addr, &info, sizeof(info))) | |
278 | return -EFAULT; | |
279 | return 0; | |
280 | } | |
281 | case Q_SETINFO: { | |
282 | struct if_dqinfo info; | |
283 | ||
284 | if (copy_from_user(&info, addr, sizeof(info))) | |
285 | return -EFAULT; | |
286 | return sb->s_qcop->set_info(sb, type, &info); | |
287 | } | |
288 | case Q_GETQUOTA: { | |
289 | struct if_dqblk idq; | |
290 | ||
268157ba JK |
291 | ret = sb->s_qcop->get_dqblk(sb, type, id, &idq); |
292 | if (ret) | |
1da177e4 LT |
293 | return ret; |
294 | if (copy_to_user(addr, &idq, sizeof(idq))) | |
295 | return -EFAULT; | |
296 | return 0; | |
297 | } | |
298 | case Q_SETQUOTA: { | |
299 | struct if_dqblk idq; | |
300 | ||
301 | if (copy_from_user(&idq, addr, sizeof(idq))) | |
302 | return -EFAULT; | |
303 | return sb->s_qcop->set_dqblk(sb, type, id, &idq); | |
304 | } | |
305 | case Q_SYNC: | |
850b201b CH |
306 | if (sb) |
307 | sync_quota_sb(sb, type); | |
308 | else | |
309 | sync_dquots(type); | |
1da177e4 LT |
310 | return 0; |
311 | ||
312 | case Q_XQUOTAON: | |
313 | case Q_XQUOTAOFF: | |
314 | case Q_XQUOTARM: { | |
315 | __u32 flags; | |
316 | ||
317 | if (copy_from_user(&flags, addr, sizeof(flags))) | |
318 | return -EFAULT; | |
319 | return sb->s_qcop->set_xstate(sb, flags, cmd); | |
320 | } | |
321 | case Q_XGETQSTAT: { | |
322 | struct fs_quota_stat fqs; | |
323 | ||
324 | if ((ret = sb->s_qcop->get_xstate(sb, &fqs))) | |
325 | return ret; | |
326 | if (copy_to_user(addr, &fqs, sizeof(fqs))) | |
327 | return -EFAULT; | |
328 | return 0; | |
329 | } | |
330 | case Q_XSETQLIM: { | |
331 | struct fs_disk_quota fdq; | |
332 | ||
333 | if (copy_from_user(&fdq, addr, sizeof(fdq))) | |
334 | return -EFAULT; | |
335 | return sb->s_qcop->set_xquota(sb, type, id, &fdq); | |
336 | } | |
337 | case Q_XGETQUOTA: { | |
338 | struct fs_disk_quota fdq; | |
339 | ||
268157ba JK |
340 | ret = sb->s_qcop->get_xquota(sb, type, id, &fdq); |
341 | if (ret) | |
1da177e4 LT |
342 | return ret; |
343 | if (copy_to_user(addr, &fdq, sizeof(fdq))) | |
344 | return -EFAULT; | |
345 | return 0; | |
346 | } | |
de69e5f4 NS |
347 | case Q_XQUOTASYNC: |
348 | return sb->s_qcop->quota_sync(sb, type); | |
1da177e4 LT |
349 | /* We never reach here unless validity check is broken */ |
350 | default: | |
351 | BUG(); | |
352 | } | |
353 | return 0; | |
354 | } | |
355 | ||
9361401e DH |
356 | /* |
357 | * look up a superblock on which quota ops will be performed | |
358 | * - use the name of a block device to find the superblock thereon | |
359 | */ | |
7a2435d8 | 360 | static struct super_block *quotactl_block(const char __user *special) |
9361401e DH |
361 | { |
362 | #ifdef CONFIG_BLOCK | |
363 | struct block_device *bdev; | |
364 | struct super_block *sb; | |
365 | char *tmp = getname(special); | |
366 | ||
367 | if (IS_ERR(tmp)) | |
e231c2ee | 368 | return ERR_CAST(tmp); |
9361401e DH |
369 | bdev = lookup_bdev(tmp); |
370 | putname(tmp); | |
371 | if (IS_ERR(bdev)) | |
e231c2ee | 372 | return ERR_CAST(bdev); |
9361401e DH |
373 | sb = get_super(bdev); |
374 | bdput(bdev); | |
375 | if (!sb) | |
376 | return ERR_PTR(-ENODEV); | |
377 | ||
378 | return sb; | |
379 | #else | |
380 | return ERR_PTR(-ENODEV); | |
381 | #endif | |
382 | } | |
383 | ||
1da177e4 LT |
384 | /* |
385 | * This is the system call interface. This communicates with | |
386 | * the user-level programs. Currently this only supports diskquota | |
387 | * calls. Maybe we need to add the process quotas etc. in the future, | |
388 | * but we probably should use rlimits for that. | |
389 | */ | |
3cdad428 HC |
390 | SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, |
391 | qid_t, id, void __user *, addr) | |
1da177e4 LT |
392 | { |
393 | uint cmds, type; | |
394 | struct super_block *sb = NULL; | |
1da177e4 LT |
395 | int ret; |
396 | ||
397 | cmds = cmd >> SUBCMDSHIFT; | |
398 | type = cmd & SUBCMDMASK; | |
399 | ||
400 | if (cmds != Q_SYNC || special) { | |
9361401e DH |
401 | sb = quotactl_block(special); |
402 | if (IS_ERR(sb)) | |
403 | return PTR_ERR(sb); | |
1da177e4 LT |
404 | } |
405 | ||
406 | ret = check_quotactl_valid(sb, type, cmds, id); | |
407 | if (ret >= 0) | |
408 | ret = do_quotactl(sb, type, cmds, id, addr); | |
409 | if (sb) | |
410 | drop_super(sb); | |
411 | ||
412 | return ret; | |
413 | } | |
b716395e | 414 | |
7a6c8135 | 415 | #if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT) |
b716395e VT |
416 | /* |
417 | * This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64) | |
418 | * and is necessary due to alignment problems. | |
419 | */ | |
420 | struct compat_if_dqblk { | |
421 | compat_u64 dqb_bhardlimit; | |
422 | compat_u64 dqb_bsoftlimit; | |
423 | compat_u64 dqb_curspace; | |
424 | compat_u64 dqb_ihardlimit; | |
425 | compat_u64 dqb_isoftlimit; | |
426 | compat_u64 dqb_curinodes; | |
427 | compat_u64 dqb_btime; | |
428 | compat_u64 dqb_itime; | |
429 | compat_uint_t dqb_valid; | |
430 | }; | |
431 | ||
432 | /* XFS structures */ | |
433 | struct compat_fs_qfilestat { | |
434 | compat_u64 dqb_bhardlimit; | |
435 | compat_u64 qfs_nblks; | |
436 | compat_uint_t qfs_nextents; | |
437 | }; | |
438 | ||
439 | struct compat_fs_quota_stat { | |
440 | __s8 qs_version; | |
441 | __u16 qs_flags; | |
442 | __s8 qs_pad; | |
443 | struct compat_fs_qfilestat qs_uquota; | |
444 | struct compat_fs_qfilestat qs_gquota; | |
445 | compat_uint_t qs_incoredqs; | |
446 | compat_int_t qs_btimelimit; | |
447 | compat_int_t qs_itimelimit; | |
448 | compat_int_t qs_rtbtimelimit; | |
449 | __u16 qs_bwarnlimit; | |
450 | __u16 qs_iwarnlimit; | |
451 | }; | |
452 | ||
453 | asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special, | |
454 | qid_t id, void __user *addr) | |
455 | { | |
456 | unsigned int cmds; | |
457 | struct if_dqblk __user *dqblk; | |
458 | struct compat_if_dqblk __user *compat_dqblk; | |
459 | struct fs_quota_stat __user *fsqstat; | |
460 | struct compat_fs_quota_stat __user *compat_fsqstat; | |
461 | compat_uint_t data; | |
462 | u16 xdata; | |
463 | long ret; | |
464 | ||
465 | cmds = cmd >> SUBCMDSHIFT; | |
466 | ||
467 | switch (cmds) { | |
468 | case Q_GETQUOTA: | |
469 | dqblk = compat_alloc_user_space(sizeof(struct if_dqblk)); | |
470 | compat_dqblk = addr; | |
471 | ret = sys_quotactl(cmd, special, id, dqblk); | |
472 | if (ret) | |
473 | break; | |
474 | if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) || | |
475 | get_user(data, &dqblk->dqb_valid) || | |
476 | put_user(data, &compat_dqblk->dqb_valid)) | |
477 | ret = -EFAULT; | |
478 | break; | |
479 | case Q_SETQUOTA: | |
480 | dqblk = compat_alloc_user_space(sizeof(struct if_dqblk)); | |
481 | compat_dqblk = addr; | |
482 | ret = -EFAULT; | |
483 | if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) || | |
484 | get_user(data, &compat_dqblk->dqb_valid) || | |
485 | put_user(data, &dqblk->dqb_valid)) | |
486 | break; | |
487 | ret = sys_quotactl(cmd, special, id, dqblk); | |
488 | break; | |
489 | case Q_XGETQSTAT: | |
490 | fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat)); | |
491 | compat_fsqstat = addr; | |
492 | ret = sys_quotactl(cmd, special, id, fsqstat); | |
493 | if (ret) | |
494 | break; | |
495 | ret = -EFAULT; | |
496 | /* Copying qs_version, qs_flags, qs_pad */ | |
497 | if (copy_in_user(compat_fsqstat, fsqstat, | |
498 | offsetof(struct compat_fs_quota_stat, qs_uquota))) | |
499 | break; | |
500 | /* Copying qs_uquota */ | |
501 | if (copy_in_user(&compat_fsqstat->qs_uquota, | |
502 | &fsqstat->qs_uquota, | |
503 | sizeof(compat_fsqstat->qs_uquota)) || | |
504 | get_user(data, &fsqstat->qs_uquota.qfs_nextents) || | |
505 | put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents)) | |
506 | break; | |
507 | /* Copying qs_gquota */ | |
508 | if (copy_in_user(&compat_fsqstat->qs_gquota, | |
509 | &fsqstat->qs_gquota, | |
510 | sizeof(compat_fsqstat->qs_gquota)) || | |
511 | get_user(data, &fsqstat->qs_gquota.qfs_nextents) || | |
512 | put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents)) | |
513 | break; | |
514 | /* Copying the rest */ | |
515 | if (copy_in_user(&compat_fsqstat->qs_incoredqs, | |
516 | &fsqstat->qs_incoredqs, | |
517 | sizeof(struct compat_fs_quota_stat) - | |
518 | offsetof(struct compat_fs_quota_stat, qs_incoredqs)) || | |
519 | get_user(xdata, &fsqstat->qs_iwarnlimit) || | |
520 | put_user(xdata, &compat_fsqstat->qs_iwarnlimit)) | |
521 | break; | |
522 | ret = 0; | |
523 | break; | |
524 | default: | |
525 | ret = sys_quotactl(cmd, special, id, addr); | |
526 | } | |
527 | return ret; | |
528 | } | |
529 | #endif | |
86e931a3 SW |
530 | |
531 | ||
532 | #ifdef CONFIG_QUOTA_NETLINK_INTERFACE | |
533 | ||
534 | /* Netlink family structure for quota */ | |
535 | static struct genl_family quota_genl_family = { | |
536 | .id = GENL_ID_GENERATE, | |
537 | .hdrsize = 0, | |
538 | .name = "VFS_DQUOT", | |
539 | .version = 1, | |
540 | .maxattr = QUOTA_NL_A_MAX, | |
541 | }; | |
542 | ||
543 | /** | |
544 | * quota_send_warning - Send warning to userspace about exceeded quota | |
545 | * @type: The quota type: USRQQUOTA, GRPQUOTA,... | |
546 | * @id: The user or group id of the quota that was exceeded | |
547 | * @dev: The device on which the fs is mounted (sb->s_dev) | |
548 | * @warntype: The type of the warning: QUOTA_NL_... | |
549 | * | |
550 | * This can be used by filesystems (including those which don't use | |
551 | * dquot) to send a message to userspace relating to quota limits. | |
552 | * | |
553 | */ | |
554 | ||
555 | void quota_send_warning(short type, unsigned int id, dev_t dev, | |
556 | const char warntype) | |
557 | { | |
558 | static atomic_t seq; | |
559 | struct sk_buff *skb; | |
560 | void *msg_head; | |
561 | int ret; | |
562 | int msg_size = 4 * nla_total_size(sizeof(u32)) + | |
563 | 2 * nla_total_size(sizeof(u64)); | |
564 | ||
565 | /* We have to allocate using GFP_NOFS as we are called from a | |
566 | * filesystem performing write and thus further recursion into | |
567 | * the fs to free some data could cause deadlocks. */ | |
568 | skb = genlmsg_new(msg_size, GFP_NOFS); | |
569 | if (!skb) { | |
570 | printk(KERN_ERR | |
571 | "VFS: Not enough memory to send quota warning.\n"); | |
572 | return; | |
573 | } | |
574 | msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq), | |
575 | "a_genl_family, 0, QUOTA_NL_C_WARNING); | |
576 | if (!msg_head) { | |
577 | printk(KERN_ERR | |
578 | "VFS: Cannot store netlink header in quota warning.\n"); | |
579 | goto err_out; | |
580 | } | |
581 | ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type); | |
582 | if (ret) | |
583 | goto attr_err_out; | |
584 | ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id); | |
585 | if (ret) | |
586 | goto attr_err_out; | |
587 | ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype); | |
588 | if (ret) | |
589 | goto attr_err_out; | |
590 | ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev)); | |
591 | if (ret) | |
592 | goto attr_err_out; | |
593 | ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev)); | |
594 | if (ret) | |
595 | goto attr_err_out; | |
596 | ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid()); | |
597 | if (ret) | |
598 | goto attr_err_out; | |
599 | genlmsg_end(skb, msg_head); | |
600 | ||
601 | genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS); | |
602 | return; | |
603 | attr_err_out: | |
604 | printk(KERN_ERR "VFS: Not enough space to compose quota message!\n"); | |
605 | err_out: | |
606 | kfree_skb(skb); | |
607 | } | |
608 | EXPORT_SYMBOL(quota_send_warning); | |
609 | ||
610 | static int __init quota_init(void) | |
611 | { | |
612 | if (genl_register_family("a_genl_family) != 0) | |
613 | printk(KERN_ERR | |
614 | "VFS: Failed to create quota netlink interface.\n"); | |
615 | return 0; | |
616 | }; | |
617 | ||
618 | module_init(quota_init); | |
619 | #endif | |
620 |