xref: /openbmc/linux/fs/quota/quota.c (revision 64d9d138)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Quota code necessary even when VFS quota support is not compiled
4  * into the kernel.  The interesting stuff is over in dquot.c, here
5  * we have symbols for initial quotactl(2) handling, the sysctl(2)
6  * variables, etc - things needed even when quota support disabled.
7  */
8 
9 #include <linux/fs.h>
10 #include <linux/namei.h>
11 #include <linux/slab.h>
12 #include <asm/current.h>
13 #include <linux/uaccess.h>
14 #include <linux/kernel.h>
15 #include <linux/security.h>
16 #include <linux/syscalls.h>
17 #include <linux/capability.h>
18 #include <linux/quotaops.h>
19 #include <linux/types.h>
20 #include <linux/writeback.h>
21 
22 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
23 				     qid_t id)
24 {
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_XGETQSTATV:
32 	case Q_XQUOTASYNC:
33 		break;
34 	/* allow to query information for dquots we "own" */
35 	case Q_GETQUOTA:
36 	case Q_XGETQUOTA:
37 		if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
38 		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
39 			break;
40 		/*FALLTHROUGH*/
41 	default:
42 		if (!capable(CAP_SYS_ADMIN))
43 			return -EPERM;
44 	}
45 
46 	return security_quotactl(cmd, type, id, sb);
47 }
48 
49 static void quota_sync_one(struct super_block *sb, void *arg)
50 {
51 	int type = *(int *)arg;
52 
53 	if (sb->s_qcop && sb->s_qcop->quota_sync &&
54 	    (sb->s_quota_types & (1 << type)))
55 		sb->s_qcop->quota_sync(sb, type);
56 }
57 
58 static int quota_sync_all(int type)
59 {
60 	int ret;
61 
62 	if (type >= MAXQUOTAS)
63 		return -EINVAL;
64 	ret = security_quotactl(Q_SYNC, type, 0, NULL);
65 	if (!ret)
66 		iterate_supers(quota_sync_one, &type);
67 	return ret;
68 }
69 
70 unsigned int qtype_enforce_flag(int type)
71 {
72 	switch (type) {
73 	case USRQUOTA:
74 		return FS_QUOTA_UDQ_ENFD;
75 	case GRPQUOTA:
76 		return FS_QUOTA_GDQ_ENFD;
77 	case PRJQUOTA:
78 		return FS_QUOTA_PDQ_ENFD;
79 	}
80 	return 0;
81 }
82 
83 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
84 		         const struct path *path)
85 {
86 	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
87 		return -ENOSYS;
88 	if (sb->s_qcop->quota_enable)
89 		return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
90 	if (IS_ERR(path))
91 		return PTR_ERR(path);
92 	return sb->s_qcop->quota_on(sb, type, id, path);
93 }
94 
95 static int quota_quotaoff(struct super_block *sb, int type)
96 {
97 	if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
98 		return -ENOSYS;
99 	if (sb->s_qcop->quota_disable)
100 		return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
101 	return sb->s_qcop->quota_off(sb, type);
102 }
103 
104 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
105 {
106 	__u32 fmt;
107 
108 	if (!sb_has_quota_active(sb, type))
109 		return -ESRCH;
110 	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
111 	if (copy_to_user(addr, &fmt, sizeof(fmt)))
112 		return -EFAULT;
113 	return 0;
114 }
115 
116 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
117 {
118 	struct qc_state state;
119 	struct qc_type_state *tstate;
120 	struct if_dqinfo uinfo;
121 	int ret;
122 
123 	if (!sb->s_qcop->get_state)
124 		return -ENOSYS;
125 	ret = sb->s_qcop->get_state(sb, &state);
126 	if (ret)
127 		return ret;
128 	tstate = state.s_state + type;
129 	if (!(tstate->flags & QCI_ACCT_ENABLED))
130 		return -ESRCH;
131 	memset(&uinfo, 0, sizeof(uinfo));
132 	uinfo.dqi_bgrace = tstate->spc_timelimit;
133 	uinfo.dqi_igrace = tstate->ino_timelimit;
134 	if (tstate->flags & QCI_SYSFILE)
135 		uinfo.dqi_flags |= DQF_SYS_FILE;
136 	if (tstate->flags & QCI_ROOT_SQUASH)
137 		uinfo.dqi_flags |= DQF_ROOT_SQUASH;
138 	uinfo.dqi_valid = IIF_ALL;
139 	if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
140 		return -EFAULT;
141 	return 0;
142 }
143 
144 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
145 {
146 	struct if_dqinfo info;
147 	struct qc_info qinfo;
148 
149 	if (copy_from_user(&info, addr, sizeof(info)))
150 		return -EFAULT;
151 	if (!sb->s_qcop->set_info)
152 		return -ENOSYS;
153 	if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
154 		return -EINVAL;
155 	memset(&qinfo, 0, sizeof(qinfo));
156 	if (info.dqi_valid & IIF_FLAGS) {
157 		if (info.dqi_flags & ~DQF_SETINFO_MASK)
158 			return -EINVAL;
159 		if (info.dqi_flags & DQF_ROOT_SQUASH)
160 			qinfo.i_flags |= QCI_ROOT_SQUASH;
161 		qinfo.i_fieldmask |= QC_FLAGS;
162 	}
163 	if (info.dqi_valid & IIF_BGRACE) {
164 		qinfo.i_spc_timelimit = info.dqi_bgrace;
165 		qinfo.i_fieldmask |= QC_SPC_TIMER;
166 	}
167 	if (info.dqi_valid & IIF_IGRACE) {
168 		qinfo.i_ino_timelimit = info.dqi_igrace;
169 		qinfo.i_fieldmask |= QC_INO_TIMER;
170 	}
171 	return sb->s_qcop->set_info(sb, type, &qinfo);
172 }
173 
174 static inline qsize_t qbtos(qsize_t blocks)
175 {
176 	return blocks << QIF_DQBLKSIZE_BITS;
177 }
178 
179 static inline qsize_t stoqb(qsize_t space)
180 {
181 	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
182 }
183 
184 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
185 {
186 	memset(dst, 0, sizeof(*dst));
187 	dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
188 	dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
189 	dst->dqb_curspace = src->d_space;
190 	dst->dqb_ihardlimit = src->d_ino_hardlimit;
191 	dst->dqb_isoftlimit = src->d_ino_softlimit;
192 	dst->dqb_curinodes = src->d_ino_count;
193 	dst->dqb_btime = src->d_spc_timer;
194 	dst->dqb_itime = src->d_ino_timer;
195 	dst->dqb_valid = QIF_ALL;
196 }
197 
198 static int quota_getquota(struct super_block *sb, int type, qid_t id,
199 			  void __user *addr)
200 {
201 	struct kqid qid;
202 	struct qc_dqblk fdq;
203 	struct if_dqblk idq;
204 	int ret;
205 
206 	if (!sb->s_qcop->get_dqblk)
207 		return -ENOSYS;
208 	qid = make_kqid(current_user_ns(), type, id);
209 	if (!qid_has_mapping(sb->s_user_ns, qid))
210 		return -EINVAL;
211 	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
212 	if (ret)
213 		return ret;
214 	copy_to_if_dqblk(&idq, &fdq);
215 	if (copy_to_user(addr, &idq, sizeof(idq)))
216 		return -EFAULT;
217 	return 0;
218 }
219 
220 /*
221  * Return quota for next active quota >= this id, if any exists,
222  * otherwise return -ENOENT via ->get_nextdqblk
223  */
224 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
225 			  void __user *addr)
226 {
227 	struct kqid qid;
228 	struct qc_dqblk fdq;
229 	struct if_nextdqblk idq;
230 	int ret;
231 
232 	if (!sb->s_qcop->get_nextdqblk)
233 		return -ENOSYS;
234 	qid = make_kqid(current_user_ns(), type, id);
235 	if (!qid_has_mapping(sb->s_user_ns, qid))
236 		return -EINVAL;
237 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
238 	if (ret)
239 		return ret;
240 	/* struct if_nextdqblk is a superset of struct if_dqblk */
241 	copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
242 	idq.dqb_id = from_kqid(current_user_ns(), qid);
243 	if (copy_to_user(addr, &idq, sizeof(idq)))
244 		return -EFAULT;
245 	return 0;
246 }
247 
248 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
249 {
250 	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
251 	dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
252 	dst->d_space = src->dqb_curspace;
253 	dst->d_ino_hardlimit = src->dqb_ihardlimit;
254 	dst->d_ino_softlimit = src->dqb_isoftlimit;
255 	dst->d_ino_count = src->dqb_curinodes;
256 	dst->d_spc_timer = src->dqb_btime;
257 	dst->d_ino_timer = src->dqb_itime;
258 
259 	dst->d_fieldmask = 0;
260 	if (src->dqb_valid & QIF_BLIMITS)
261 		dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
262 	if (src->dqb_valid & QIF_SPACE)
263 		dst->d_fieldmask |= QC_SPACE;
264 	if (src->dqb_valid & QIF_ILIMITS)
265 		dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
266 	if (src->dqb_valid & QIF_INODES)
267 		dst->d_fieldmask |= QC_INO_COUNT;
268 	if (src->dqb_valid & QIF_BTIME)
269 		dst->d_fieldmask |= QC_SPC_TIMER;
270 	if (src->dqb_valid & QIF_ITIME)
271 		dst->d_fieldmask |= QC_INO_TIMER;
272 }
273 
274 static int quota_setquota(struct super_block *sb, int type, qid_t id,
275 			  void __user *addr)
276 {
277 	struct qc_dqblk fdq;
278 	struct if_dqblk idq;
279 	struct kqid qid;
280 
281 	if (copy_from_user(&idq, addr, sizeof(idq)))
282 		return -EFAULT;
283 	if (!sb->s_qcop->set_dqblk)
284 		return -ENOSYS;
285 	qid = make_kqid(current_user_ns(), type, id);
286 	if (!qid_has_mapping(sb->s_user_ns, qid))
287 		return -EINVAL;
288 	copy_from_if_dqblk(&fdq, &idq);
289 	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
290 }
291 
292 static int quota_enable(struct super_block *sb, void __user *addr)
293 {
294 	__u32 flags;
295 
296 	if (copy_from_user(&flags, addr, sizeof(flags)))
297 		return -EFAULT;
298 	if (!sb->s_qcop->quota_enable)
299 		return -ENOSYS;
300 	return sb->s_qcop->quota_enable(sb, flags);
301 }
302 
303 static int quota_disable(struct super_block *sb, void __user *addr)
304 {
305 	__u32 flags;
306 
307 	if (copy_from_user(&flags, addr, sizeof(flags)))
308 		return -EFAULT;
309 	if (!sb->s_qcop->quota_disable)
310 		return -ENOSYS;
311 	return sb->s_qcop->quota_disable(sb, flags);
312 }
313 
314 static int quota_state_to_flags(struct qc_state *state)
315 {
316 	int flags = 0;
317 
318 	if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
319 		flags |= FS_QUOTA_UDQ_ACCT;
320 	if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
321 		flags |= FS_QUOTA_UDQ_ENFD;
322 	if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
323 		flags |= FS_QUOTA_GDQ_ACCT;
324 	if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
325 		flags |= FS_QUOTA_GDQ_ENFD;
326 	if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
327 		flags |= FS_QUOTA_PDQ_ACCT;
328 	if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
329 		flags |= FS_QUOTA_PDQ_ENFD;
330 	return flags;
331 }
332 
333 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
334 {
335 	int type;
336 	struct qc_state state;
337 	int ret;
338 
339 	memset(&state, 0, sizeof (struct qc_state));
340 	ret = sb->s_qcop->get_state(sb, &state);
341 	if (ret < 0)
342 		return ret;
343 
344 	memset(fqs, 0, sizeof(*fqs));
345 	fqs->qs_version = FS_QSTAT_VERSION;
346 	fqs->qs_flags = quota_state_to_flags(&state);
347 	/* No quota enabled? */
348 	if (!fqs->qs_flags)
349 		return -ENOSYS;
350 	fqs->qs_incoredqs = state.s_incoredqs;
351 	/*
352 	 * GETXSTATE quotactl has space for just one set of time limits so
353 	 * report them for the first enabled quota type
354 	 */
355 	for (type = 0; type < MAXQUOTAS; type++)
356 		if (state.s_state[type].flags & QCI_ACCT_ENABLED)
357 			break;
358 	BUG_ON(type == MAXQUOTAS);
359 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
360 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
361 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
362 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
363 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
364 
365 	/* Inodes may be allocated even if inactive; copy out if present */
366 	if (state.s_state[USRQUOTA].ino) {
367 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
368 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
369 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
370 	}
371 	if (state.s_state[GRPQUOTA].ino) {
372 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
373 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
374 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
375 	}
376 	if (state.s_state[PRJQUOTA].ino) {
377 		/*
378 		 * Q_XGETQSTAT doesn't have room for both group and project
379 		 * quotas.  So, allow the project quota values to be copied out
380 		 * only if there is no group quota information available.
381 		 */
382 		if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
383 			fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
384 			fqs->qs_gquota.qfs_nblks =
385 					state.s_state[PRJQUOTA].blocks;
386 			fqs->qs_gquota.qfs_nextents =
387 					state.s_state[PRJQUOTA].nextents;
388 		}
389 	}
390 	return 0;
391 }
392 
393 static int quota_getxstate(struct super_block *sb, void __user *addr)
394 {
395 	struct fs_quota_stat fqs;
396 	int ret;
397 
398 	if (!sb->s_qcop->get_state)
399 		return -ENOSYS;
400 	ret = quota_getstate(sb, &fqs);
401 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
402 		return -EFAULT;
403 	return ret;
404 }
405 
406 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
407 {
408 	int type;
409 	struct qc_state state;
410 	int ret;
411 
412 	memset(&state, 0, sizeof (struct qc_state));
413 	ret = sb->s_qcop->get_state(sb, &state);
414 	if (ret < 0)
415 		return ret;
416 
417 	memset(fqs, 0, sizeof(*fqs));
418 	fqs->qs_version = FS_QSTAT_VERSION;
419 	fqs->qs_flags = quota_state_to_flags(&state);
420 	/* No quota enabled? */
421 	if (!fqs->qs_flags)
422 		return -ENOSYS;
423 	fqs->qs_incoredqs = state.s_incoredqs;
424 	/*
425 	 * GETXSTATV quotactl has space for just one set of time limits so
426 	 * report them for the first enabled quota type
427 	 */
428 	for (type = 0; type < MAXQUOTAS; type++)
429 		if (state.s_state[type].flags & QCI_ACCT_ENABLED)
430 			break;
431 	BUG_ON(type == MAXQUOTAS);
432 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
433 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
434 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
435 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
436 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
437 
438 	/* Inodes may be allocated even if inactive; copy out if present */
439 	if (state.s_state[USRQUOTA].ino) {
440 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
441 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
442 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
443 	}
444 	if (state.s_state[GRPQUOTA].ino) {
445 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
446 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
447 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
448 	}
449 	if (state.s_state[PRJQUOTA].ino) {
450 		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
451 		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
452 		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
453 	}
454 	return 0;
455 }
456 
457 static int quota_getxstatev(struct super_block *sb, void __user *addr)
458 {
459 	struct fs_quota_statv fqs;
460 	int ret;
461 
462 	if (!sb->s_qcop->get_state)
463 		return -ENOSYS;
464 
465 	memset(&fqs, 0, sizeof(fqs));
466 	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
467 		return -EFAULT;
468 
469 	/* If this kernel doesn't support user specified version, fail */
470 	switch (fqs.qs_version) {
471 	case FS_QSTATV_VERSION1:
472 		break;
473 	default:
474 		return -EINVAL;
475 	}
476 	ret = quota_getstatev(sb, &fqs);
477 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
478 		return -EFAULT;
479 	return ret;
480 }
481 
482 /*
483  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
484  * out of there as xfsprogs rely on definitions being in that header file. So
485  * just define same functions here for quota purposes.
486  */
487 #define XFS_BB_SHIFT 9
488 
489 static inline u64 quota_bbtob(u64 blocks)
490 {
491 	return blocks << XFS_BB_SHIFT;
492 }
493 
494 static inline u64 quota_btobb(u64 bytes)
495 {
496 	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
497 }
498 
499 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
500 {
501 	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
502 	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
503 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
504 	dst->d_ino_softlimit = src->d_ino_softlimit;
505 	dst->d_space = quota_bbtob(src->d_bcount);
506 	dst->d_ino_count = src->d_icount;
507 	dst->d_ino_timer = src->d_itimer;
508 	dst->d_spc_timer = src->d_btimer;
509 	dst->d_ino_warns = src->d_iwarns;
510 	dst->d_spc_warns = src->d_bwarns;
511 	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
512 	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
513 	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
514 	dst->d_rt_spc_timer = src->d_rtbtimer;
515 	dst->d_rt_spc_warns = src->d_rtbwarns;
516 	dst->d_fieldmask = 0;
517 	if (src->d_fieldmask & FS_DQ_ISOFT)
518 		dst->d_fieldmask |= QC_INO_SOFT;
519 	if (src->d_fieldmask & FS_DQ_IHARD)
520 		dst->d_fieldmask |= QC_INO_HARD;
521 	if (src->d_fieldmask & FS_DQ_BSOFT)
522 		dst->d_fieldmask |= QC_SPC_SOFT;
523 	if (src->d_fieldmask & FS_DQ_BHARD)
524 		dst->d_fieldmask |= QC_SPC_HARD;
525 	if (src->d_fieldmask & FS_DQ_RTBSOFT)
526 		dst->d_fieldmask |= QC_RT_SPC_SOFT;
527 	if (src->d_fieldmask & FS_DQ_RTBHARD)
528 		dst->d_fieldmask |= QC_RT_SPC_HARD;
529 	if (src->d_fieldmask & FS_DQ_BTIMER)
530 		dst->d_fieldmask |= QC_SPC_TIMER;
531 	if (src->d_fieldmask & FS_DQ_ITIMER)
532 		dst->d_fieldmask |= QC_INO_TIMER;
533 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
534 		dst->d_fieldmask |= QC_RT_SPC_TIMER;
535 	if (src->d_fieldmask & FS_DQ_BWARNS)
536 		dst->d_fieldmask |= QC_SPC_WARNS;
537 	if (src->d_fieldmask & FS_DQ_IWARNS)
538 		dst->d_fieldmask |= QC_INO_WARNS;
539 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
540 		dst->d_fieldmask |= QC_RT_SPC_WARNS;
541 	if (src->d_fieldmask & FS_DQ_BCOUNT)
542 		dst->d_fieldmask |= QC_SPACE;
543 	if (src->d_fieldmask & FS_DQ_ICOUNT)
544 		dst->d_fieldmask |= QC_INO_COUNT;
545 	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
546 		dst->d_fieldmask |= QC_RT_SPACE;
547 }
548 
549 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
550 				       struct fs_disk_quota *src)
551 {
552 	memset(dst, 0, sizeof(*dst));
553 	dst->i_spc_timelimit = src->d_btimer;
554 	dst->i_ino_timelimit = src->d_itimer;
555 	dst->i_rt_spc_timelimit = src->d_rtbtimer;
556 	dst->i_ino_warnlimit = src->d_iwarns;
557 	dst->i_spc_warnlimit = src->d_bwarns;
558 	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
559 	if (src->d_fieldmask & FS_DQ_BWARNS)
560 		dst->i_fieldmask |= QC_SPC_WARNS;
561 	if (src->d_fieldmask & FS_DQ_IWARNS)
562 		dst->i_fieldmask |= QC_INO_WARNS;
563 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
564 		dst->i_fieldmask |= QC_RT_SPC_WARNS;
565 	if (src->d_fieldmask & FS_DQ_BTIMER)
566 		dst->i_fieldmask |= QC_SPC_TIMER;
567 	if (src->d_fieldmask & FS_DQ_ITIMER)
568 		dst->i_fieldmask |= QC_INO_TIMER;
569 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
570 		dst->i_fieldmask |= QC_RT_SPC_TIMER;
571 }
572 
573 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
574 			   void __user *addr)
575 {
576 	struct fs_disk_quota fdq;
577 	struct qc_dqblk qdq;
578 	struct kqid qid;
579 
580 	if (copy_from_user(&fdq, addr, sizeof(fdq)))
581 		return -EFAULT;
582 	if (!sb->s_qcop->set_dqblk)
583 		return -ENOSYS;
584 	qid = make_kqid(current_user_ns(), type, id);
585 	if (!qid_has_mapping(sb->s_user_ns, qid))
586 		return -EINVAL;
587 	/* Are we actually setting timer / warning limits for all users? */
588 	if (from_kqid(sb->s_user_ns, qid) == 0 &&
589 	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
590 		struct qc_info qinfo;
591 		int ret;
592 
593 		if (!sb->s_qcop->set_info)
594 			return -EINVAL;
595 		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
596 		ret = sb->s_qcop->set_info(sb, type, &qinfo);
597 		if (ret)
598 			return ret;
599 		/* These are already done */
600 		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
601 	}
602 	copy_from_xfs_dqblk(&qdq, &fdq);
603 	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
604 }
605 
606 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
607 			      int type, qid_t id)
608 {
609 	memset(dst, 0, sizeof(*dst));
610 	dst->d_version = FS_DQUOT_VERSION;
611 	dst->d_id = id;
612 	if (type == USRQUOTA)
613 		dst->d_flags = FS_USER_QUOTA;
614 	else if (type == PRJQUOTA)
615 		dst->d_flags = FS_PROJ_QUOTA;
616 	else
617 		dst->d_flags = FS_GROUP_QUOTA;
618 	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
619 	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
620 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
621 	dst->d_ino_softlimit = src->d_ino_softlimit;
622 	dst->d_bcount = quota_btobb(src->d_space);
623 	dst->d_icount = src->d_ino_count;
624 	dst->d_itimer = src->d_ino_timer;
625 	dst->d_btimer = src->d_spc_timer;
626 	dst->d_iwarns = src->d_ino_warns;
627 	dst->d_bwarns = src->d_spc_warns;
628 	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
629 	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
630 	dst->d_rtbcount = quota_btobb(src->d_rt_space);
631 	dst->d_rtbtimer = src->d_rt_spc_timer;
632 	dst->d_rtbwarns = src->d_rt_spc_warns;
633 }
634 
635 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
636 			   void __user *addr)
637 {
638 	struct fs_disk_quota fdq;
639 	struct qc_dqblk qdq;
640 	struct kqid qid;
641 	int ret;
642 
643 	if (!sb->s_qcop->get_dqblk)
644 		return -ENOSYS;
645 	qid = make_kqid(current_user_ns(), type, id);
646 	if (!qid_has_mapping(sb->s_user_ns, qid))
647 		return -EINVAL;
648 	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
649 	if (ret)
650 		return ret;
651 	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
652 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
653 		return -EFAULT;
654 	return ret;
655 }
656 
657 /*
658  * Return quota for next active quota >= this id, if any exists,
659  * otherwise return -ENOENT via ->get_nextdqblk.
660  */
661 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
662 			    void __user *addr)
663 {
664 	struct fs_disk_quota fdq;
665 	struct qc_dqblk qdq;
666 	struct kqid qid;
667 	qid_t id_out;
668 	int ret;
669 
670 	if (!sb->s_qcop->get_nextdqblk)
671 		return -ENOSYS;
672 	qid = make_kqid(current_user_ns(), type, id);
673 	if (!qid_has_mapping(sb->s_user_ns, qid))
674 		return -EINVAL;
675 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
676 	if (ret)
677 		return ret;
678 	id_out = from_kqid(current_user_ns(), qid);
679 	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
680 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
681 		return -EFAULT;
682 	return ret;
683 }
684 
685 static int quota_rmxquota(struct super_block *sb, void __user *addr)
686 {
687 	__u32 flags;
688 
689 	if (copy_from_user(&flags, addr, sizeof(flags)))
690 		return -EFAULT;
691 	if (!sb->s_qcop->rm_xquota)
692 		return -ENOSYS;
693 	return sb->s_qcop->rm_xquota(sb, flags);
694 }
695 
696 /* Copy parameters and call proper function */
697 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
698 		       void __user *addr, const struct path *path)
699 {
700 	int ret;
701 
702 	if (type >= MAXQUOTAS)
703 		return -EINVAL;
704 	/*
705 	 * Quota not supported on this fs? Check this before s_quota_types
706 	 * since they needn't be set if quota is not supported at all.
707 	 */
708 	if (!sb->s_qcop)
709 		return -ENOSYS;
710 	if (!(sb->s_quota_types & (1 << type)))
711 		return -EINVAL;
712 
713 	ret = check_quotactl_permission(sb, type, cmd, id);
714 	if (ret < 0)
715 		return ret;
716 
717 	switch (cmd) {
718 	case Q_QUOTAON:
719 		return quota_quotaon(sb, type, id, path);
720 	case Q_QUOTAOFF:
721 		return quota_quotaoff(sb, type);
722 	case Q_GETFMT:
723 		return quota_getfmt(sb, type, addr);
724 	case Q_GETINFO:
725 		return quota_getinfo(sb, type, addr);
726 	case Q_SETINFO:
727 		return quota_setinfo(sb, type, addr);
728 	case Q_GETQUOTA:
729 		return quota_getquota(sb, type, id, addr);
730 	case Q_GETNEXTQUOTA:
731 		return quota_getnextquota(sb, type, id, addr);
732 	case Q_SETQUOTA:
733 		return quota_setquota(sb, type, id, addr);
734 	case Q_SYNC:
735 		if (!sb->s_qcop->quota_sync)
736 			return -ENOSYS;
737 		return sb->s_qcop->quota_sync(sb, type);
738 	case Q_XQUOTAON:
739 		return quota_enable(sb, addr);
740 	case Q_XQUOTAOFF:
741 		return quota_disable(sb, addr);
742 	case Q_XQUOTARM:
743 		return quota_rmxquota(sb, addr);
744 	case Q_XGETQSTAT:
745 		return quota_getxstate(sb, addr);
746 	case Q_XGETQSTATV:
747 		return quota_getxstatev(sb, addr);
748 	case Q_XSETQLIM:
749 		return quota_setxquota(sb, type, id, addr);
750 	case Q_XGETQUOTA:
751 		return quota_getxquota(sb, type, id, addr);
752 	case Q_XGETNEXTQUOTA:
753 		return quota_getnextxquota(sb, type, id, addr);
754 	case Q_XQUOTASYNC:
755 		if (sb_rdonly(sb))
756 			return -EROFS;
757 		/* XFS quotas are fully coherent now, making this call a noop */
758 		return 0;
759 	default:
760 		return -EINVAL;
761 	}
762 }
763 
764 #ifdef CONFIG_BLOCK
765 
766 /* Return 1 if 'cmd' will block on frozen filesystem */
767 static int quotactl_cmd_write(int cmd)
768 {
769 	/*
770 	 * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
771 	 * as dquot_acquire() may allocate space for new structure and OCFS2
772 	 * needs to increment on-disk use count.
773 	 */
774 	switch (cmd) {
775 	case Q_GETFMT:
776 	case Q_GETINFO:
777 	case Q_SYNC:
778 	case Q_XGETQSTAT:
779 	case Q_XGETQSTATV:
780 	case Q_XGETQUOTA:
781 	case Q_XGETNEXTQUOTA:
782 	case Q_XQUOTASYNC:
783 		return 0;
784 	}
785 	return 1;
786 }
787 #endif /* CONFIG_BLOCK */
788 
789 /* Return true if quotactl command is manipulating quota on/off state */
790 static bool quotactl_cmd_onoff(int cmd)
791 {
792 	return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF);
793 }
794 
795 /*
796  * look up a superblock on which quota ops will be performed
797  * - use the name of a block device to find the superblock thereon
798  */
799 static struct super_block *quotactl_block(const char __user *special, int cmd)
800 {
801 #ifdef CONFIG_BLOCK
802 	struct block_device *bdev;
803 	struct super_block *sb;
804 	struct filename *tmp = getname(special);
805 
806 	if (IS_ERR(tmp))
807 		return ERR_CAST(tmp);
808 	bdev = lookup_bdev(tmp->name);
809 	putname(tmp);
810 	if (IS_ERR(bdev))
811 		return ERR_CAST(bdev);
812 	if (quotactl_cmd_onoff(cmd))
813 		sb = get_super_exclusive_thawed(bdev);
814 	else if (quotactl_cmd_write(cmd))
815 		sb = get_super_thawed(bdev);
816 	else
817 		sb = get_super(bdev);
818 	bdput(bdev);
819 	if (!sb)
820 		return ERR_PTR(-ENODEV);
821 
822 	return sb;
823 #else
824 	return ERR_PTR(-ENODEV);
825 #endif
826 }
827 
828 /*
829  * This is the system call interface. This communicates with
830  * the user-level programs. Currently this only supports diskquota
831  * calls. Maybe we need to add the process quotas etc. in the future,
832  * but we probably should use rlimits for that.
833  */
834 int kernel_quotactl(unsigned int cmd, const char __user *special,
835 		    qid_t id, void __user *addr)
836 {
837 	uint cmds, type;
838 	struct super_block *sb = NULL;
839 	struct path path, *pathp = NULL;
840 	int ret;
841 
842 	cmds = cmd >> SUBCMDSHIFT;
843 	type = cmd & SUBCMDMASK;
844 
845 	/*
846 	 * As a special case Q_SYNC can be called without a specific device.
847 	 * It will iterate all superblocks that have quota enabled and call
848 	 * the sync action on each of them.
849 	 */
850 	if (!special) {
851 		if (cmds == Q_SYNC)
852 			return quota_sync_all(type);
853 		return -ENODEV;
854 	}
855 
856 	/*
857 	 * Path for quotaon has to be resolved before grabbing superblock
858 	 * because that gets s_umount sem which is also possibly needed by path
859 	 * resolution (think about autofs) and thus deadlocks could arise.
860 	 */
861 	if (cmds == Q_QUOTAON) {
862 		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
863 		if (ret)
864 			pathp = ERR_PTR(ret);
865 		else
866 			pathp = &path;
867 	}
868 
869 	sb = quotactl_block(special, cmds);
870 	if (IS_ERR(sb)) {
871 		ret = PTR_ERR(sb);
872 		goto out;
873 	}
874 
875 	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
876 
877 	if (!quotactl_cmd_onoff(cmds))
878 		drop_super(sb);
879 	else
880 		drop_super_exclusive(sb);
881 out:
882 	if (pathp && !IS_ERR(pathp))
883 		path_put(pathp);
884 	return ret;
885 }
886 
887 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
888 		qid_t, id, void __user *, addr)
889 {
890 	return kernel_quotactl(cmd, special, id, addr);
891 }
892