xref: /linux/fs/quota/quota.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
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 <linux/uaccess.h>
13 #include <linux/kernel.h>
14 #include <linux/security.h>
15 #include <linux/syscalls.h>
16 #include <linux/capability.h>
17 #include <linux/quotaops.h>
18 #include <linux/types.h>
19 #include <linux/writeback.h>
20 
21 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
22 				     qid_t id)
23 {
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:
30 	case Q_XGETQSTATV:
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 && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
37 		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
38 			break;
39 		/*FALLTHROUGH*/
40 	default:
41 		if (!capable(CAP_SYS_ADMIN))
42 			return -EPERM;
43 	}
44 
45 	return security_quotactl(cmd, type, id, sb);
46 }
47 
48 static void quota_sync_one(struct super_block *sb, void *arg)
49 {
50 	int type = *(int *)arg;
51 
52 	if (sb->s_qcop && sb->s_qcop->quota_sync &&
53 	    (sb->s_quota_types & (1 << type)))
54 		sb->s_qcop->quota_sync(sb, type);
55 }
56 
57 static int quota_sync_all(int type)
58 {
59 	int ret;
60 
61 	if (type >= MAXQUOTAS)
62 		return -EINVAL;
63 	ret = security_quotactl(Q_SYNC, type, 0, NULL);
64 	if (!ret)
65 		iterate_supers(quota_sync_one, &type);
66 	return ret;
67 }
68 
69 unsigned int qtype_enforce_flag(int type)
70 {
71 	switch (type) {
72 	case USRQUOTA:
73 		return FS_QUOTA_UDQ_ENFD;
74 	case GRPQUOTA:
75 		return FS_QUOTA_GDQ_ENFD;
76 	case PRJQUOTA:
77 		return FS_QUOTA_PDQ_ENFD;
78 	}
79 	return 0;
80 }
81 
82 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
83 		         struct path *path)
84 {
85 	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
86 		return -ENOSYS;
87 	if (sb->s_qcop->quota_enable)
88 		return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
89 	if (IS_ERR(path))
90 		return PTR_ERR(path);
91 	return sb->s_qcop->quota_on(sb, type, id, path);
92 }
93 
94 static int quota_quotaoff(struct super_block *sb, int type)
95 {
96 	if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
97 		return -ENOSYS;
98 	if (sb->s_qcop->quota_disable)
99 		return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
100 	return sb->s_qcop->quota_off(sb, type);
101 }
102 
103 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
104 {
105 	__u32 fmt;
106 
107 	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
108 	if (!sb_has_quota_active(sb, type)) {
109 		mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
110 		return -ESRCH;
111 	}
112 	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
113 	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
114 	if (copy_to_user(addr, &fmt, sizeof(fmt)))
115 		return -EFAULT;
116 	return 0;
117 }
118 
119 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
120 {
121 	struct qc_state state;
122 	struct qc_type_state *tstate;
123 	struct if_dqinfo uinfo;
124 	int ret;
125 
126 	/* This checks whether qc_state has enough entries... */
127 	BUILD_BUG_ON(MAXQUOTAS > XQM_MAXQUOTAS);
128 	if (!sb->s_qcop->get_state)
129 		return -ENOSYS;
130 	ret = sb->s_qcop->get_state(sb, &state);
131 	if (ret)
132 		return ret;
133 	tstate = state.s_state + type;
134 	if (!(tstate->flags & QCI_ACCT_ENABLED))
135 		return -ESRCH;
136 	memset(&uinfo, 0, sizeof(uinfo));
137 	uinfo.dqi_bgrace = tstate->spc_timelimit;
138 	uinfo.dqi_igrace = tstate->ino_timelimit;
139 	if (tstate->flags & QCI_SYSFILE)
140 		uinfo.dqi_flags |= DQF_SYS_FILE;
141 	if (tstate->flags & QCI_ROOT_SQUASH)
142 		uinfo.dqi_flags |= DQF_ROOT_SQUASH;
143 	uinfo.dqi_valid = IIF_ALL;
144 	if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
145 		return -EFAULT;
146 	return 0;
147 }
148 
149 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
150 {
151 	struct if_dqinfo info;
152 	struct qc_info qinfo;
153 
154 	if (copy_from_user(&info, addr, sizeof(info)))
155 		return -EFAULT;
156 	if (!sb->s_qcop->set_info)
157 		return -ENOSYS;
158 	if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
159 		return -EINVAL;
160 	memset(&qinfo, 0, sizeof(qinfo));
161 	if (info.dqi_valid & IIF_FLAGS) {
162 		if (info.dqi_flags & ~DQF_SETINFO_MASK)
163 			return -EINVAL;
164 		if (info.dqi_flags & DQF_ROOT_SQUASH)
165 			qinfo.i_flags |= QCI_ROOT_SQUASH;
166 		qinfo.i_fieldmask |= QC_FLAGS;
167 	}
168 	if (info.dqi_valid & IIF_BGRACE) {
169 		qinfo.i_spc_timelimit = info.dqi_bgrace;
170 		qinfo.i_fieldmask |= QC_SPC_TIMER;
171 	}
172 	if (info.dqi_valid & IIF_IGRACE) {
173 		qinfo.i_ino_timelimit = info.dqi_igrace;
174 		qinfo.i_fieldmask |= QC_INO_TIMER;
175 	}
176 	return sb->s_qcop->set_info(sb, type, &qinfo);
177 }
178 
179 static inline qsize_t qbtos(qsize_t blocks)
180 {
181 	return blocks << QIF_DQBLKSIZE_BITS;
182 }
183 
184 static inline qsize_t stoqb(qsize_t space)
185 {
186 	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
187 }
188 
189 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
190 {
191 	memset(dst, 0, sizeof(*dst));
192 	dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
193 	dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
194 	dst->dqb_curspace = src->d_space;
195 	dst->dqb_ihardlimit = src->d_ino_hardlimit;
196 	dst->dqb_isoftlimit = src->d_ino_softlimit;
197 	dst->dqb_curinodes = src->d_ino_count;
198 	dst->dqb_btime = src->d_spc_timer;
199 	dst->dqb_itime = src->d_ino_timer;
200 	dst->dqb_valid = QIF_ALL;
201 }
202 
203 static int quota_getquota(struct super_block *sb, int type, qid_t id,
204 			  void __user *addr)
205 {
206 	struct kqid qid;
207 	struct qc_dqblk fdq;
208 	struct if_dqblk idq;
209 	int ret;
210 
211 	if (!sb->s_qcop->get_dqblk)
212 		return -ENOSYS;
213 	qid = make_kqid(current_user_ns(), type, id);
214 	if (!qid_has_mapping(sb->s_user_ns, qid))
215 		return -EINVAL;
216 	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
217 	if (ret)
218 		return ret;
219 	copy_to_if_dqblk(&idq, &fdq);
220 	if (copy_to_user(addr, &idq, sizeof(idq)))
221 		return -EFAULT;
222 	return 0;
223 }
224 
225 /*
226  * Return quota for next active quota >= this id, if any exists,
227  * otherwise return -ENOENT via ->get_nextdqblk
228  */
229 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
230 			  void __user *addr)
231 {
232 	struct kqid qid;
233 	struct qc_dqblk fdq;
234 	struct if_nextdqblk idq;
235 	int ret;
236 
237 	if (!sb->s_qcop->get_nextdqblk)
238 		return -ENOSYS;
239 	qid = make_kqid(current_user_ns(), type, id);
240 	if (!qid_has_mapping(sb->s_user_ns, qid))
241 		return -EINVAL;
242 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
243 	if (ret)
244 		return ret;
245 	/* struct if_nextdqblk is a superset of struct if_dqblk */
246 	copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
247 	idq.dqb_id = from_kqid(current_user_ns(), qid);
248 	if (copy_to_user(addr, &idq, sizeof(idq)))
249 		return -EFAULT;
250 	return 0;
251 }
252 
253 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
254 {
255 	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
256 	dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
257 	dst->d_space = src->dqb_curspace;
258 	dst->d_ino_hardlimit = src->dqb_ihardlimit;
259 	dst->d_ino_softlimit = src->dqb_isoftlimit;
260 	dst->d_ino_count = src->dqb_curinodes;
261 	dst->d_spc_timer = src->dqb_btime;
262 	dst->d_ino_timer = src->dqb_itime;
263 
264 	dst->d_fieldmask = 0;
265 	if (src->dqb_valid & QIF_BLIMITS)
266 		dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
267 	if (src->dqb_valid & QIF_SPACE)
268 		dst->d_fieldmask |= QC_SPACE;
269 	if (src->dqb_valid & QIF_ILIMITS)
270 		dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
271 	if (src->dqb_valid & QIF_INODES)
272 		dst->d_fieldmask |= QC_INO_COUNT;
273 	if (src->dqb_valid & QIF_BTIME)
274 		dst->d_fieldmask |= QC_SPC_TIMER;
275 	if (src->dqb_valid & QIF_ITIME)
276 		dst->d_fieldmask |= QC_INO_TIMER;
277 }
278 
279 static int quota_setquota(struct super_block *sb, int type, qid_t id,
280 			  void __user *addr)
281 {
282 	struct qc_dqblk fdq;
283 	struct if_dqblk idq;
284 	struct kqid qid;
285 
286 	if (copy_from_user(&idq, addr, sizeof(idq)))
287 		return -EFAULT;
288 	if (!sb->s_qcop->set_dqblk)
289 		return -ENOSYS;
290 	qid = make_kqid(current_user_ns(), type, id);
291 	if (!qid_has_mapping(sb->s_user_ns, qid))
292 		return -EINVAL;
293 	copy_from_if_dqblk(&fdq, &idq);
294 	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
295 }
296 
297 static int quota_enable(struct super_block *sb, void __user *addr)
298 {
299 	__u32 flags;
300 
301 	if (copy_from_user(&flags, addr, sizeof(flags)))
302 		return -EFAULT;
303 	if (!sb->s_qcop->quota_enable)
304 		return -ENOSYS;
305 	return sb->s_qcop->quota_enable(sb, flags);
306 }
307 
308 static int quota_disable(struct super_block *sb, void __user *addr)
309 {
310 	__u32 flags;
311 
312 	if (copy_from_user(&flags, addr, sizeof(flags)))
313 		return -EFAULT;
314 	if (!sb->s_qcop->quota_disable)
315 		return -ENOSYS;
316 	return sb->s_qcop->quota_disable(sb, flags);
317 }
318 
319 static int quota_state_to_flags(struct qc_state *state)
320 {
321 	int flags = 0;
322 
323 	if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
324 		flags |= FS_QUOTA_UDQ_ACCT;
325 	if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
326 		flags |= FS_QUOTA_UDQ_ENFD;
327 	if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
328 		flags |= FS_QUOTA_GDQ_ACCT;
329 	if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
330 		flags |= FS_QUOTA_GDQ_ENFD;
331 	if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
332 		flags |= FS_QUOTA_PDQ_ACCT;
333 	if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
334 		flags |= FS_QUOTA_PDQ_ENFD;
335 	return flags;
336 }
337 
338 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
339 {
340 	int type;
341 	struct qc_state state;
342 	int ret;
343 
344 	ret = sb->s_qcop->get_state(sb, &state);
345 	if (ret < 0)
346 		return ret;
347 
348 	memset(fqs, 0, sizeof(*fqs));
349 	fqs->qs_version = FS_QSTAT_VERSION;
350 	fqs->qs_flags = quota_state_to_flags(&state);
351 	/* No quota enabled? */
352 	if (!fqs->qs_flags)
353 		return -ENOSYS;
354 	fqs->qs_incoredqs = state.s_incoredqs;
355 	/*
356 	 * GETXSTATE quotactl has space for just one set of time limits so
357 	 * report them for the first enabled quota type
358 	 */
359 	for (type = 0; type < XQM_MAXQUOTAS; type++)
360 		if (state.s_state[type].flags & QCI_ACCT_ENABLED)
361 			break;
362 	BUG_ON(type == XQM_MAXQUOTAS);
363 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
364 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
365 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
366 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
367 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
368 	if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
369 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
370 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
371 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
372 	}
373 	if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
374 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
375 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
376 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
377 	}
378 	if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
379 		/*
380 		 * Q_XGETQSTAT doesn't have room for both group and project
381 		 * quotas.  So, allow the project quota values to be copied out
382 		 * only if there is no group quota information available.
383 		 */
384 		if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
385 			fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
386 			fqs->qs_gquota.qfs_nblks =
387 					state.s_state[PRJQUOTA].blocks;
388 			fqs->qs_gquota.qfs_nextents =
389 					state.s_state[PRJQUOTA].nextents;
390 		}
391 	}
392 	return 0;
393 }
394 
395 static int quota_getxstate(struct super_block *sb, void __user *addr)
396 {
397 	struct fs_quota_stat fqs;
398 	int ret;
399 
400 	if (!sb->s_qcop->get_state)
401 		return -ENOSYS;
402 	ret = quota_getstate(sb, &fqs);
403 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
404 		return -EFAULT;
405 	return ret;
406 }
407 
408 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
409 {
410 	int type;
411 	struct qc_state state;
412 	int ret;
413 
414 	ret = sb->s_qcop->get_state(sb, &state);
415 	if (ret < 0)
416 		return ret;
417 
418 	memset(fqs, 0, sizeof(*fqs));
419 	fqs->qs_version = FS_QSTAT_VERSION;
420 	fqs->qs_flags = quota_state_to_flags(&state);
421 	/* No quota enabled? */
422 	if (!fqs->qs_flags)
423 		return -ENOSYS;
424 	fqs->qs_incoredqs = state.s_incoredqs;
425 	/*
426 	 * GETXSTATV quotactl has space for just one set of time limits so
427 	 * report them for the first enabled quota type
428 	 */
429 	for (type = 0; type < XQM_MAXQUOTAS; type++)
430 		if (state.s_state[type].flags & QCI_ACCT_ENABLED)
431 			break;
432 	BUG_ON(type == XQM_MAXQUOTAS);
433 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
434 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
435 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
436 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
437 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
438 	if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
439 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
440 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
441 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
442 	}
443 	if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
444 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
445 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
446 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
447 	}
448 	if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
449 		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
450 		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
451 		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
452 	}
453 	return 0;
454 }
455 
456 static int quota_getxstatev(struct super_block *sb, void __user *addr)
457 {
458 	struct fs_quota_statv fqs;
459 	int ret;
460 
461 	if (!sb->s_qcop->get_state)
462 		return -ENOSYS;
463 
464 	memset(&fqs, 0, sizeof(fqs));
465 	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
466 		return -EFAULT;
467 
468 	/* If this kernel doesn't support user specified version, fail */
469 	switch (fqs.qs_version) {
470 	case FS_QSTATV_VERSION1:
471 		break;
472 	default:
473 		return -EINVAL;
474 	}
475 	ret = quota_getstatev(sb, &fqs);
476 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
477 		return -EFAULT;
478 	return ret;
479 }
480 
481 /*
482  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
483  * out of there as xfsprogs rely on definitions being in that header file. So
484  * just define same functions here for quota purposes.
485  */
486 #define XFS_BB_SHIFT 9
487 
488 static inline u64 quota_bbtob(u64 blocks)
489 {
490 	return blocks << XFS_BB_SHIFT;
491 }
492 
493 static inline u64 quota_btobb(u64 bytes)
494 {
495 	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
496 }
497 
498 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
499 {
500 	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
501 	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
502 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
503 	dst->d_ino_softlimit = src->d_ino_softlimit;
504 	dst->d_space = quota_bbtob(src->d_bcount);
505 	dst->d_ino_count = src->d_icount;
506 	dst->d_ino_timer = src->d_itimer;
507 	dst->d_spc_timer = src->d_btimer;
508 	dst->d_ino_warns = src->d_iwarns;
509 	dst->d_spc_warns = src->d_bwarns;
510 	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
511 	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
512 	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
513 	dst->d_rt_spc_timer = src->d_rtbtimer;
514 	dst->d_rt_spc_warns = src->d_rtbwarns;
515 	dst->d_fieldmask = 0;
516 	if (src->d_fieldmask & FS_DQ_ISOFT)
517 		dst->d_fieldmask |= QC_INO_SOFT;
518 	if (src->d_fieldmask & FS_DQ_IHARD)
519 		dst->d_fieldmask |= QC_INO_HARD;
520 	if (src->d_fieldmask & FS_DQ_BSOFT)
521 		dst->d_fieldmask |= QC_SPC_SOFT;
522 	if (src->d_fieldmask & FS_DQ_BHARD)
523 		dst->d_fieldmask |= QC_SPC_HARD;
524 	if (src->d_fieldmask & FS_DQ_RTBSOFT)
525 		dst->d_fieldmask |= QC_RT_SPC_SOFT;
526 	if (src->d_fieldmask & FS_DQ_RTBHARD)
527 		dst->d_fieldmask |= QC_RT_SPC_HARD;
528 	if (src->d_fieldmask & FS_DQ_BTIMER)
529 		dst->d_fieldmask |= QC_SPC_TIMER;
530 	if (src->d_fieldmask & FS_DQ_ITIMER)
531 		dst->d_fieldmask |= QC_INO_TIMER;
532 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
533 		dst->d_fieldmask |= QC_RT_SPC_TIMER;
534 	if (src->d_fieldmask & FS_DQ_BWARNS)
535 		dst->d_fieldmask |= QC_SPC_WARNS;
536 	if (src->d_fieldmask & FS_DQ_IWARNS)
537 		dst->d_fieldmask |= QC_INO_WARNS;
538 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
539 		dst->d_fieldmask |= QC_RT_SPC_WARNS;
540 	if (src->d_fieldmask & FS_DQ_BCOUNT)
541 		dst->d_fieldmask |= QC_SPACE;
542 	if (src->d_fieldmask & FS_DQ_ICOUNT)
543 		dst->d_fieldmask |= QC_INO_COUNT;
544 	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
545 		dst->d_fieldmask |= QC_RT_SPACE;
546 }
547 
548 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
549 				       struct fs_disk_quota *src)
550 {
551 	memset(dst, 0, sizeof(*dst));
552 	dst->i_spc_timelimit = src->d_btimer;
553 	dst->i_ino_timelimit = src->d_itimer;
554 	dst->i_rt_spc_timelimit = src->d_rtbtimer;
555 	dst->i_ino_warnlimit = src->d_iwarns;
556 	dst->i_spc_warnlimit = src->d_bwarns;
557 	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
558 	if (src->d_fieldmask & FS_DQ_BWARNS)
559 		dst->i_fieldmask |= QC_SPC_WARNS;
560 	if (src->d_fieldmask & FS_DQ_IWARNS)
561 		dst->i_fieldmask |= QC_INO_WARNS;
562 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
563 		dst->i_fieldmask |= QC_RT_SPC_WARNS;
564 	if (src->d_fieldmask & FS_DQ_BTIMER)
565 		dst->i_fieldmask |= QC_SPC_TIMER;
566 	if (src->d_fieldmask & FS_DQ_ITIMER)
567 		dst->i_fieldmask |= QC_INO_TIMER;
568 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
569 		dst->i_fieldmask |= QC_RT_SPC_TIMER;
570 }
571 
572 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
573 			   void __user *addr)
574 {
575 	struct fs_disk_quota fdq;
576 	struct qc_dqblk qdq;
577 	struct kqid qid;
578 
579 	if (copy_from_user(&fdq, addr, sizeof(fdq)))
580 		return -EFAULT;
581 	if (!sb->s_qcop->set_dqblk)
582 		return -ENOSYS;
583 	qid = make_kqid(current_user_ns(), type, id);
584 	if (!qid_has_mapping(sb->s_user_ns, qid))
585 		return -EINVAL;
586 	/* Are we actually setting timer / warning limits for all users? */
587 	if (from_kqid(sb->s_user_ns, qid) == 0 &&
588 	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
589 		struct qc_info qinfo;
590 		int ret;
591 
592 		if (!sb->s_qcop->set_info)
593 			return -EINVAL;
594 		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
595 		ret = sb->s_qcop->set_info(sb, type, &qinfo);
596 		if (ret)
597 			return ret;
598 		/* These are already done */
599 		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
600 	}
601 	copy_from_xfs_dqblk(&qdq, &fdq);
602 	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
603 }
604 
605 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
606 			      int type, qid_t id)
607 {
608 	memset(dst, 0, sizeof(*dst));
609 	dst->d_version = FS_DQUOT_VERSION;
610 	dst->d_id = id;
611 	if (type == USRQUOTA)
612 		dst->d_flags = FS_USER_QUOTA;
613 	else if (type == PRJQUOTA)
614 		dst->d_flags = FS_PROJ_QUOTA;
615 	else
616 		dst->d_flags = FS_GROUP_QUOTA;
617 	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
618 	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
619 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
620 	dst->d_ino_softlimit = src->d_ino_softlimit;
621 	dst->d_bcount = quota_btobb(src->d_space);
622 	dst->d_icount = src->d_ino_count;
623 	dst->d_itimer = src->d_ino_timer;
624 	dst->d_btimer = src->d_spc_timer;
625 	dst->d_iwarns = src->d_ino_warns;
626 	dst->d_bwarns = src->d_spc_warns;
627 	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
628 	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
629 	dst->d_rtbcount = quota_btobb(src->d_rt_space);
630 	dst->d_rtbtimer = src->d_rt_spc_timer;
631 	dst->d_rtbwarns = src->d_rt_spc_warns;
632 }
633 
634 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
635 			   void __user *addr)
636 {
637 	struct fs_disk_quota fdq;
638 	struct qc_dqblk qdq;
639 	struct kqid qid;
640 	int ret;
641 
642 	if (!sb->s_qcop->get_dqblk)
643 		return -ENOSYS;
644 	qid = make_kqid(current_user_ns(), type, id);
645 	if (!qid_has_mapping(sb->s_user_ns, qid))
646 		return -EINVAL;
647 	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
648 	if (ret)
649 		return ret;
650 	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
651 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
652 		return -EFAULT;
653 	return ret;
654 }
655 
656 /*
657  * Return quota for next active quota >= this id, if any exists,
658  * otherwise return -ENOENT via ->get_nextdqblk.
659  */
660 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
661 			    void __user *addr)
662 {
663 	struct fs_disk_quota fdq;
664 	struct qc_dqblk qdq;
665 	struct kqid qid;
666 	qid_t id_out;
667 	int ret;
668 
669 	if (!sb->s_qcop->get_nextdqblk)
670 		return -ENOSYS;
671 	qid = make_kqid(current_user_ns(), type, id);
672 	if (!qid_has_mapping(sb->s_user_ns, qid))
673 		return -EINVAL;
674 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
675 	if (ret)
676 		return ret;
677 	id_out = from_kqid(current_user_ns(), qid);
678 	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
679 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
680 		return -EFAULT;
681 	return ret;
682 }
683 
684 static int quota_rmxquota(struct super_block *sb, void __user *addr)
685 {
686 	__u32 flags;
687 
688 	if (copy_from_user(&flags, addr, sizeof(flags)))
689 		return -EFAULT;
690 	if (!sb->s_qcop->rm_xquota)
691 		return -ENOSYS;
692 	return sb->s_qcop->rm_xquota(sb, flags);
693 }
694 
695 /* Copy parameters and call proper function */
696 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
697 		       void __user *addr, struct path *path)
698 {
699 	int ret;
700 
701 	if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
702 		return -EINVAL;
703 	/*
704 	 * Quota not supported on this fs? Check this before s_quota_types
705 	 * since they needn't be set if quota is not supported at all.
706 	 */
707 	if (!sb->s_qcop)
708 		return -ENOSYS;
709 	if (!(sb->s_quota_types & (1 << type)))
710 		return -EINVAL;
711 
712 	ret = check_quotactl_permission(sb, type, cmd, id);
713 	if (ret < 0)
714 		return ret;
715 
716 	switch (cmd) {
717 	case Q_QUOTAON:
718 		return quota_quotaon(sb, type, id, path);
719 	case Q_QUOTAOFF:
720 		return quota_quotaoff(sb, type);
721 	case Q_GETFMT:
722 		return quota_getfmt(sb, type, addr);
723 	case Q_GETINFO:
724 		return quota_getinfo(sb, type, addr);
725 	case Q_SETINFO:
726 		return quota_setinfo(sb, type, addr);
727 	case Q_GETQUOTA:
728 		return quota_getquota(sb, type, id, addr);
729 	case Q_GETNEXTQUOTA:
730 		return quota_getnextquota(sb, type, id, addr);
731 	case Q_SETQUOTA:
732 		return quota_setquota(sb, type, id, addr);
733 	case Q_SYNC:
734 		if (!sb->s_qcop->quota_sync)
735 			return -ENOSYS;
736 		return sb->s_qcop->quota_sync(sb, type);
737 	case Q_XQUOTAON:
738 		return quota_enable(sb, addr);
739 	case Q_XQUOTAOFF:
740 		return quota_disable(sb, addr);
741 	case Q_XQUOTARM:
742 		return quota_rmxquota(sb, addr);
743 	case Q_XGETQSTAT:
744 		return quota_getxstate(sb, addr);
745 	case Q_XGETQSTATV:
746 		return quota_getxstatev(sb, addr);
747 	case Q_XSETQLIM:
748 		return quota_setxquota(sb, type, id, addr);
749 	case Q_XGETQUOTA:
750 		return quota_getxquota(sb, type, id, addr);
751 	case Q_XGETNEXTQUOTA:
752 		return quota_getnextxquota(sb, type, id, addr);
753 	case Q_XQUOTASYNC:
754 		if (sb->s_flags & MS_RDONLY)
755 			return -EROFS;
756 		/* XFS quotas are fully coherent now, making this call a noop */
757 		return 0;
758 	default:
759 		return -EINVAL;
760 	}
761 }
762 
763 #ifdef CONFIG_BLOCK
764 
765 /* Return 1 if 'cmd' will block on frozen filesystem */
766 static int quotactl_cmd_write(int cmd)
767 {
768 	/*
769 	 * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
770 	 * as dquot_acquire() may allocate space for new structure and OCFS2
771 	 * needs to increment on-disk use count.
772 	 */
773 	switch (cmd) {
774 	case Q_GETFMT:
775 	case Q_GETINFO:
776 	case Q_SYNC:
777 	case Q_XGETQSTAT:
778 	case Q_XGETQSTATV:
779 	case Q_XGETQUOTA:
780 	case Q_XGETNEXTQUOTA:
781 	case Q_XQUOTASYNC:
782 		return 0;
783 	}
784 	return 1;
785 }
786 
787 #endif /* CONFIG_BLOCK */
788 
789 /*
790  * look up a superblock on which quota ops will be performed
791  * - use the name of a block device to find the superblock thereon
792  */
793 static struct super_block *quotactl_block(const char __user *special, int cmd)
794 {
795 #ifdef CONFIG_BLOCK
796 	struct block_device *bdev;
797 	struct super_block *sb;
798 	struct filename *tmp = getname(special);
799 
800 	if (IS_ERR(tmp))
801 		return ERR_CAST(tmp);
802 	bdev = lookup_bdev(tmp->name);
803 	putname(tmp);
804 	if (IS_ERR(bdev))
805 		return ERR_CAST(bdev);
806 	if (quotactl_cmd_write(cmd))
807 		sb = get_super_thawed(bdev);
808 	else
809 		sb = get_super(bdev);
810 	bdput(bdev);
811 	if (!sb)
812 		return ERR_PTR(-ENODEV);
813 
814 	return sb;
815 #else
816 	return ERR_PTR(-ENODEV);
817 #endif
818 }
819 
820 /*
821  * This is the system call interface. This communicates with
822  * the user-level programs. Currently this only supports diskquota
823  * calls. Maybe we need to add the process quotas etc. in the future,
824  * but we probably should use rlimits for that.
825  */
826 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
827 		qid_t, id, void __user *, addr)
828 {
829 	uint cmds, type;
830 	struct super_block *sb = NULL;
831 	struct path path, *pathp = NULL;
832 	int ret;
833 
834 	cmds = cmd >> SUBCMDSHIFT;
835 	type = cmd & SUBCMDMASK;
836 
837 	/*
838 	 * As a special case Q_SYNC can be called without a specific device.
839 	 * It will iterate all superblocks that have quota enabled and call
840 	 * the sync action on each of them.
841 	 */
842 	if (!special) {
843 		if (cmds == Q_SYNC)
844 			return quota_sync_all(type);
845 		return -ENODEV;
846 	}
847 
848 	/*
849 	 * Path for quotaon has to be resolved before grabbing superblock
850 	 * because that gets s_umount sem which is also possibly needed by path
851 	 * resolution (think about autofs) and thus deadlocks could arise.
852 	 */
853 	if (cmds == Q_QUOTAON) {
854 		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
855 		if (ret)
856 			pathp = ERR_PTR(ret);
857 		else
858 			pathp = &path;
859 	}
860 
861 	sb = quotactl_block(special, cmds);
862 	if (IS_ERR(sb)) {
863 		ret = PTR_ERR(sb);
864 		goto out;
865 	}
866 
867 	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
868 
869 	drop_super(sb);
870 out:
871 	if (pathp && !IS_ERR(pathp))
872 		path_put(pathp);
873 	return ret;
874 }
875