xref: /linux/fs/quota/quota.c (revision be709d48329a500621d2a05835283150ae137b45)
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 #include <linux/nospec.h>
22 
23 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
24 				     qid_t id)
25 {
26 	switch (cmd) {
27 	/* these commands do not require any special privilegues */
28 	case Q_GETFMT:
29 	case Q_SYNC:
30 	case Q_GETINFO:
31 	case Q_XGETQSTAT:
32 	case Q_XGETQSTATV:
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 && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
39 		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
40 			break;
41 		/*FALLTHROUGH*/
42 	default:
43 		if (!capable(CAP_SYS_ADMIN))
44 			return -EPERM;
45 	}
46 
47 	return security_quotactl(cmd, type, id, sb);
48 }
49 
50 static void quota_sync_one(struct super_block *sb, void *arg)
51 {
52 	int type = *(int *)arg;
53 
54 	if (sb->s_qcop && sb->s_qcop->quota_sync &&
55 	    (sb->s_quota_types & (1 << type)))
56 		sb->s_qcop->quota_sync(sb, type);
57 }
58 
59 static int quota_sync_all(int type)
60 {
61 	int ret;
62 
63 	if (type >= MAXQUOTAS)
64 		return -EINVAL;
65 	ret = security_quotactl(Q_SYNC, type, 0, NULL);
66 	if (!ret)
67 		iterate_supers(quota_sync_one, &type);
68 	return ret;
69 }
70 
71 unsigned int qtype_enforce_flag(int type)
72 {
73 	switch (type) {
74 	case USRQUOTA:
75 		return FS_QUOTA_UDQ_ENFD;
76 	case GRPQUOTA:
77 		return FS_QUOTA_GDQ_ENFD;
78 	case PRJQUOTA:
79 		return FS_QUOTA_PDQ_ENFD;
80 	}
81 	return 0;
82 }
83 
84 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
85 		         const struct path *path)
86 {
87 	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
88 		return -ENOSYS;
89 	if (sb->s_qcop->quota_enable)
90 		return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
91 	if (IS_ERR(path))
92 		return PTR_ERR(path);
93 	return sb->s_qcop->quota_on(sb, type, id, path);
94 }
95 
96 static int quota_quotaoff(struct super_block *sb, int type)
97 {
98 	if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
99 		return -ENOSYS;
100 	if (sb->s_qcop->quota_disable)
101 		return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
102 	return sb->s_qcop->quota_off(sb, type);
103 }
104 
105 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
106 {
107 	__u32 fmt;
108 
109 	if (!sb_has_quota_active(sb, type))
110 		return -ESRCH;
111 	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
112 	if (copy_to_user(addr, &fmt, sizeof(fmt)))
113 		return -EFAULT;
114 	return 0;
115 }
116 
117 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
118 {
119 	struct qc_state state;
120 	struct qc_type_state *tstate;
121 	struct if_dqinfo uinfo;
122 	int ret;
123 
124 	if (!sb->s_qcop->get_state)
125 		return -ENOSYS;
126 	ret = sb->s_qcop->get_state(sb, &state);
127 	if (ret)
128 		return ret;
129 	tstate = state.s_state + type;
130 	if (!(tstate->flags & QCI_ACCT_ENABLED))
131 		return -ESRCH;
132 	memset(&uinfo, 0, sizeof(uinfo));
133 	uinfo.dqi_bgrace = tstate->spc_timelimit;
134 	uinfo.dqi_igrace = tstate->ino_timelimit;
135 	if (tstate->flags & QCI_SYSFILE)
136 		uinfo.dqi_flags |= DQF_SYS_FILE;
137 	if (tstate->flags & QCI_ROOT_SQUASH)
138 		uinfo.dqi_flags |= DQF_ROOT_SQUASH;
139 	uinfo.dqi_valid = IIF_ALL;
140 	if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
141 		return -EFAULT;
142 	return 0;
143 }
144 
145 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
146 {
147 	struct if_dqinfo info;
148 	struct qc_info qinfo;
149 
150 	if (copy_from_user(&info, addr, sizeof(info)))
151 		return -EFAULT;
152 	if (!sb->s_qcop->set_info)
153 		return -ENOSYS;
154 	if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
155 		return -EINVAL;
156 	memset(&qinfo, 0, sizeof(qinfo));
157 	if (info.dqi_valid & IIF_FLAGS) {
158 		if (info.dqi_flags & ~DQF_SETINFO_MASK)
159 			return -EINVAL;
160 		if (info.dqi_flags & DQF_ROOT_SQUASH)
161 			qinfo.i_flags |= QCI_ROOT_SQUASH;
162 		qinfo.i_fieldmask |= QC_FLAGS;
163 	}
164 	if (info.dqi_valid & IIF_BGRACE) {
165 		qinfo.i_spc_timelimit = info.dqi_bgrace;
166 		qinfo.i_fieldmask |= QC_SPC_TIMER;
167 	}
168 	if (info.dqi_valid & IIF_IGRACE) {
169 		qinfo.i_ino_timelimit = info.dqi_igrace;
170 		qinfo.i_fieldmask |= QC_INO_TIMER;
171 	}
172 	return sb->s_qcop->set_info(sb, type, &qinfo);
173 }
174 
175 static inline qsize_t qbtos(qsize_t blocks)
176 {
177 	return blocks << QIF_DQBLKSIZE_BITS;
178 }
179 
180 static inline qsize_t stoqb(qsize_t space)
181 {
182 	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
183 }
184 
185 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
186 {
187 	memset(dst, 0, sizeof(*dst));
188 	dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
189 	dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
190 	dst->dqb_curspace = src->d_space;
191 	dst->dqb_ihardlimit = src->d_ino_hardlimit;
192 	dst->dqb_isoftlimit = src->d_ino_softlimit;
193 	dst->dqb_curinodes = src->d_ino_count;
194 	dst->dqb_btime = src->d_spc_timer;
195 	dst->dqb_itime = src->d_ino_timer;
196 	dst->dqb_valid = QIF_ALL;
197 }
198 
199 static int quota_getquota(struct super_block *sb, int type, qid_t id,
200 			  void __user *addr)
201 {
202 	struct kqid qid;
203 	struct qc_dqblk fdq;
204 	struct if_dqblk idq;
205 	int ret;
206 
207 	if (!sb->s_qcop->get_dqblk)
208 		return -ENOSYS;
209 	qid = make_kqid(current_user_ns(), type, id);
210 	if (!qid_has_mapping(sb->s_user_ns, qid))
211 		return -EINVAL;
212 	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
213 	if (ret)
214 		return ret;
215 	copy_to_if_dqblk(&idq, &fdq);
216 	if (copy_to_user(addr, &idq, sizeof(idq)))
217 		return -EFAULT;
218 	return 0;
219 }
220 
221 /*
222  * Return quota for next active quota >= this id, if any exists,
223  * otherwise return -ENOENT via ->get_nextdqblk
224  */
225 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
226 			  void __user *addr)
227 {
228 	struct kqid qid;
229 	struct qc_dqblk fdq;
230 	struct if_nextdqblk idq;
231 	int ret;
232 
233 	if (!sb->s_qcop->get_nextdqblk)
234 		return -ENOSYS;
235 	qid = make_kqid(current_user_ns(), type, id);
236 	if (!qid_has_mapping(sb->s_user_ns, qid))
237 		return -EINVAL;
238 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
239 	if (ret)
240 		return ret;
241 	/* struct if_nextdqblk is a superset of struct if_dqblk */
242 	copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
243 	idq.dqb_id = from_kqid(current_user_ns(), qid);
244 	if (copy_to_user(addr, &idq, sizeof(idq)))
245 		return -EFAULT;
246 	return 0;
247 }
248 
249 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
250 {
251 	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
252 	dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
253 	dst->d_space = src->dqb_curspace;
254 	dst->d_ino_hardlimit = src->dqb_ihardlimit;
255 	dst->d_ino_softlimit = src->dqb_isoftlimit;
256 	dst->d_ino_count = src->dqb_curinodes;
257 	dst->d_spc_timer = src->dqb_btime;
258 	dst->d_ino_timer = src->dqb_itime;
259 
260 	dst->d_fieldmask = 0;
261 	if (src->dqb_valid & QIF_BLIMITS)
262 		dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
263 	if (src->dqb_valid & QIF_SPACE)
264 		dst->d_fieldmask |= QC_SPACE;
265 	if (src->dqb_valid & QIF_ILIMITS)
266 		dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
267 	if (src->dqb_valid & QIF_INODES)
268 		dst->d_fieldmask |= QC_INO_COUNT;
269 	if (src->dqb_valid & QIF_BTIME)
270 		dst->d_fieldmask |= QC_SPC_TIMER;
271 	if (src->dqb_valid & QIF_ITIME)
272 		dst->d_fieldmask |= QC_INO_TIMER;
273 }
274 
275 static int quota_setquota(struct super_block *sb, int type, qid_t id,
276 			  void __user *addr)
277 {
278 	struct qc_dqblk fdq;
279 	struct if_dqblk idq;
280 	struct kqid qid;
281 
282 	if (copy_from_user(&idq, addr, sizeof(idq)))
283 		return -EFAULT;
284 	if (!sb->s_qcop->set_dqblk)
285 		return -ENOSYS;
286 	qid = make_kqid(current_user_ns(), type, id);
287 	if (!qid_has_mapping(sb->s_user_ns, qid))
288 		return -EINVAL;
289 	copy_from_if_dqblk(&fdq, &idq);
290 	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
291 }
292 
293 static int quota_enable(struct super_block *sb, void __user *addr)
294 {
295 	__u32 flags;
296 
297 	if (copy_from_user(&flags, addr, sizeof(flags)))
298 		return -EFAULT;
299 	if (!sb->s_qcop->quota_enable)
300 		return -ENOSYS;
301 	return sb->s_qcop->quota_enable(sb, flags);
302 }
303 
304 static int quota_disable(struct super_block *sb, void __user *addr)
305 {
306 	__u32 flags;
307 
308 	if (copy_from_user(&flags, addr, sizeof(flags)))
309 		return -EFAULT;
310 	if (!sb->s_qcop->quota_disable)
311 		return -ENOSYS;
312 	return sb->s_qcop->quota_disable(sb, flags);
313 }
314 
315 static int quota_state_to_flags(struct qc_state *state)
316 {
317 	int flags = 0;
318 
319 	if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
320 		flags |= FS_QUOTA_UDQ_ACCT;
321 	if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
322 		flags |= FS_QUOTA_UDQ_ENFD;
323 	if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
324 		flags |= FS_QUOTA_GDQ_ACCT;
325 	if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
326 		flags |= FS_QUOTA_GDQ_ENFD;
327 	if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
328 		flags |= FS_QUOTA_PDQ_ACCT;
329 	if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
330 		flags |= FS_QUOTA_PDQ_ENFD;
331 	return flags;
332 }
333 
334 static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
335 {
336 	int type;
337 	struct qc_state state;
338 	int ret;
339 
340 	memset(&state, 0, sizeof (struct qc_state));
341 	ret = sb->s_qcop->get_state(sb, &state);
342 	if (ret < 0)
343 		return ret;
344 
345 	memset(fqs, 0, sizeof(*fqs));
346 	fqs->qs_version = FS_QSTAT_VERSION;
347 	fqs->qs_flags = quota_state_to_flags(&state);
348 	/* No quota enabled? */
349 	if (!fqs->qs_flags)
350 		return -ENOSYS;
351 	fqs->qs_incoredqs = state.s_incoredqs;
352 	/*
353 	 * GETXSTATE quotactl has space for just one set of time limits so
354 	 * report them for the first enabled quota type
355 	 */
356 	for (type = 0; type < MAXQUOTAS; type++)
357 		if (state.s_state[type].flags & QCI_ACCT_ENABLED)
358 			break;
359 	BUG_ON(type == MAXQUOTAS);
360 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
361 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
362 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
363 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
364 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
365 
366 	/* Inodes may be allocated even if inactive; copy out if present */
367 	if (state.s_state[USRQUOTA].ino) {
368 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
369 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
370 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
371 	}
372 	if (state.s_state[GRPQUOTA].ino) {
373 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
374 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
375 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
376 	}
377 	if (state.s_state[PRJQUOTA].ino) {
378 		/*
379 		 * Q_XGETQSTAT doesn't have room for both group and project
380 		 * quotas.  So, allow the project quota values to be copied out
381 		 * only if there is no group quota information available.
382 		 */
383 		if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
384 			fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
385 			fqs->qs_gquota.qfs_nblks =
386 					state.s_state[PRJQUOTA].blocks;
387 			fqs->qs_gquota.qfs_nextents =
388 					state.s_state[PRJQUOTA].nextents;
389 		}
390 	}
391 	return 0;
392 }
393 
394 static int quota_getxstate(struct super_block *sb, void __user *addr)
395 {
396 	struct fs_quota_stat fqs;
397 	int ret;
398 
399 	if (!sb->s_qcop->get_state)
400 		return -ENOSYS;
401 	ret = quota_getstate(sb, &fqs);
402 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
403 		return -EFAULT;
404 	return ret;
405 }
406 
407 static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
408 {
409 	int type;
410 	struct qc_state state;
411 	int ret;
412 
413 	memset(&state, 0, sizeof (struct qc_state));
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 < MAXQUOTAS; type++)
430 		if (state.s_state[type].flags & QCI_ACCT_ENABLED)
431 			break;
432 	BUG_ON(type == 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 
439 	/* Inodes may be allocated even if inactive; copy out if present */
440 	if (state.s_state[USRQUOTA].ino) {
441 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
442 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
443 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
444 	}
445 	if (state.s_state[GRPQUOTA].ino) {
446 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
447 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
448 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
449 	}
450 	if (state.s_state[PRJQUOTA].ino) {
451 		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
452 		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
453 		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
454 	}
455 	return 0;
456 }
457 
458 static int quota_getxstatev(struct super_block *sb, void __user *addr)
459 {
460 	struct fs_quota_statv fqs;
461 	int ret;
462 
463 	if (!sb->s_qcop->get_state)
464 		return -ENOSYS;
465 
466 	memset(&fqs, 0, sizeof(fqs));
467 	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
468 		return -EFAULT;
469 
470 	/* If this kernel doesn't support user specified version, fail */
471 	switch (fqs.qs_version) {
472 	case FS_QSTATV_VERSION1:
473 		break;
474 	default:
475 		return -EINVAL;
476 	}
477 	ret = quota_getstatev(sb, &fqs);
478 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
479 		return -EFAULT;
480 	return ret;
481 }
482 
483 /*
484  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
485  * out of there as xfsprogs rely on definitions being in that header file. So
486  * just define same functions here for quota purposes.
487  */
488 #define XFS_BB_SHIFT 9
489 
490 static inline u64 quota_bbtob(u64 blocks)
491 {
492 	return blocks << XFS_BB_SHIFT;
493 }
494 
495 static inline u64 quota_btobb(u64 bytes)
496 {
497 	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
498 }
499 
500 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
501 {
502 	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
503 	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
504 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
505 	dst->d_ino_softlimit = src->d_ino_softlimit;
506 	dst->d_space = quota_bbtob(src->d_bcount);
507 	dst->d_ino_count = src->d_icount;
508 	dst->d_ino_timer = src->d_itimer;
509 	dst->d_spc_timer = src->d_btimer;
510 	dst->d_ino_warns = src->d_iwarns;
511 	dst->d_spc_warns = src->d_bwarns;
512 	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
513 	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
514 	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
515 	dst->d_rt_spc_timer = src->d_rtbtimer;
516 	dst->d_rt_spc_warns = src->d_rtbwarns;
517 	dst->d_fieldmask = 0;
518 	if (src->d_fieldmask & FS_DQ_ISOFT)
519 		dst->d_fieldmask |= QC_INO_SOFT;
520 	if (src->d_fieldmask & FS_DQ_IHARD)
521 		dst->d_fieldmask |= QC_INO_HARD;
522 	if (src->d_fieldmask & FS_DQ_BSOFT)
523 		dst->d_fieldmask |= QC_SPC_SOFT;
524 	if (src->d_fieldmask & FS_DQ_BHARD)
525 		dst->d_fieldmask |= QC_SPC_HARD;
526 	if (src->d_fieldmask & FS_DQ_RTBSOFT)
527 		dst->d_fieldmask |= QC_RT_SPC_SOFT;
528 	if (src->d_fieldmask & FS_DQ_RTBHARD)
529 		dst->d_fieldmask |= QC_RT_SPC_HARD;
530 	if (src->d_fieldmask & FS_DQ_BTIMER)
531 		dst->d_fieldmask |= QC_SPC_TIMER;
532 	if (src->d_fieldmask & FS_DQ_ITIMER)
533 		dst->d_fieldmask |= QC_INO_TIMER;
534 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
535 		dst->d_fieldmask |= QC_RT_SPC_TIMER;
536 	if (src->d_fieldmask & FS_DQ_BWARNS)
537 		dst->d_fieldmask |= QC_SPC_WARNS;
538 	if (src->d_fieldmask & FS_DQ_IWARNS)
539 		dst->d_fieldmask |= QC_INO_WARNS;
540 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
541 		dst->d_fieldmask |= QC_RT_SPC_WARNS;
542 	if (src->d_fieldmask & FS_DQ_BCOUNT)
543 		dst->d_fieldmask |= QC_SPACE;
544 	if (src->d_fieldmask & FS_DQ_ICOUNT)
545 		dst->d_fieldmask |= QC_INO_COUNT;
546 	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
547 		dst->d_fieldmask |= QC_RT_SPACE;
548 }
549 
550 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
551 				       struct fs_disk_quota *src)
552 {
553 	memset(dst, 0, sizeof(*dst));
554 	dst->i_spc_timelimit = src->d_btimer;
555 	dst->i_ino_timelimit = src->d_itimer;
556 	dst->i_rt_spc_timelimit = src->d_rtbtimer;
557 	dst->i_ino_warnlimit = src->d_iwarns;
558 	dst->i_spc_warnlimit = src->d_bwarns;
559 	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
560 	if (src->d_fieldmask & FS_DQ_BWARNS)
561 		dst->i_fieldmask |= QC_SPC_WARNS;
562 	if (src->d_fieldmask & FS_DQ_IWARNS)
563 		dst->i_fieldmask |= QC_INO_WARNS;
564 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
565 		dst->i_fieldmask |= QC_RT_SPC_WARNS;
566 	if (src->d_fieldmask & FS_DQ_BTIMER)
567 		dst->i_fieldmask |= QC_SPC_TIMER;
568 	if (src->d_fieldmask & FS_DQ_ITIMER)
569 		dst->i_fieldmask |= QC_INO_TIMER;
570 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
571 		dst->i_fieldmask |= QC_RT_SPC_TIMER;
572 }
573 
574 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
575 			   void __user *addr)
576 {
577 	struct fs_disk_quota fdq;
578 	struct qc_dqblk qdq;
579 	struct kqid qid;
580 
581 	if (copy_from_user(&fdq, addr, sizeof(fdq)))
582 		return -EFAULT;
583 	if (!sb->s_qcop->set_dqblk)
584 		return -ENOSYS;
585 	qid = make_kqid(current_user_ns(), type, id);
586 	if (!qid_has_mapping(sb->s_user_ns, qid))
587 		return -EINVAL;
588 	/* Are we actually setting timer / warning limits for all users? */
589 	if (from_kqid(sb->s_user_ns, qid) == 0 &&
590 	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
591 		struct qc_info qinfo;
592 		int ret;
593 
594 		if (!sb->s_qcop->set_info)
595 			return -EINVAL;
596 		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
597 		ret = sb->s_qcop->set_info(sb, type, &qinfo);
598 		if (ret)
599 			return ret;
600 		/* These are already done */
601 		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
602 	}
603 	copy_from_xfs_dqblk(&qdq, &fdq);
604 	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
605 }
606 
607 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
608 			      int type, qid_t id)
609 {
610 	memset(dst, 0, sizeof(*dst));
611 	dst->d_version = FS_DQUOT_VERSION;
612 	dst->d_id = id;
613 	if (type == USRQUOTA)
614 		dst->d_flags = FS_USER_QUOTA;
615 	else if (type == PRJQUOTA)
616 		dst->d_flags = FS_PROJ_QUOTA;
617 	else
618 		dst->d_flags = FS_GROUP_QUOTA;
619 	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
620 	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
621 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
622 	dst->d_ino_softlimit = src->d_ino_softlimit;
623 	dst->d_bcount = quota_btobb(src->d_space);
624 	dst->d_icount = src->d_ino_count;
625 	dst->d_itimer = src->d_ino_timer;
626 	dst->d_btimer = src->d_spc_timer;
627 	dst->d_iwarns = src->d_ino_warns;
628 	dst->d_bwarns = src->d_spc_warns;
629 	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
630 	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
631 	dst->d_rtbcount = quota_btobb(src->d_rt_space);
632 	dst->d_rtbtimer = src->d_rt_spc_timer;
633 	dst->d_rtbwarns = src->d_rt_spc_warns;
634 }
635 
636 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
637 			   void __user *addr)
638 {
639 	struct fs_disk_quota fdq;
640 	struct qc_dqblk qdq;
641 	struct kqid qid;
642 	int ret;
643 
644 	if (!sb->s_qcop->get_dqblk)
645 		return -ENOSYS;
646 	qid = make_kqid(current_user_ns(), type, id);
647 	if (!qid_has_mapping(sb->s_user_ns, qid))
648 		return -EINVAL;
649 	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
650 	if (ret)
651 		return ret;
652 	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
653 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
654 		return -EFAULT;
655 	return ret;
656 }
657 
658 /*
659  * Return quota for next active quota >= this id, if any exists,
660  * otherwise return -ENOENT via ->get_nextdqblk.
661  */
662 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
663 			    void __user *addr)
664 {
665 	struct fs_disk_quota fdq;
666 	struct qc_dqblk qdq;
667 	struct kqid qid;
668 	qid_t id_out;
669 	int ret;
670 
671 	if (!sb->s_qcop->get_nextdqblk)
672 		return -ENOSYS;
673 	qid = make_kqid(current_user_ns(), type, id);
674 	if (!qid_has_mapping(sb->s_user_ns, qid))
675 		return -EINVAL;
676 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
677 	if (ret)
678 		return ret;
679 	id_out = from_kqid(current_user_ns(), qid);
680 	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
681 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
682 		return -EFAULT;
683 	return ret;
684 }
685 
686 static int quota_rmxquota(struct super_block *sb, void __user *addr)
687 {
688 	__u32 flags;
689 
690 	if (copy_from_user(&flags, addr, sizeof(flags)))
691 		return -EFAULT;
692 	if (!sb->s_qcop->rm_xquota)
693 		return -ENOSYS;
694 	return sb->s_qcop->rm_xquota(sb, flags);
695 }
696 
697 /* Copy parameters and call proper function */
698 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
699 		       void __user *addr, const struct path *path)
700 {
701 	int ret;
702 
703 	if (type >= MAXQUOTAS)
704 		return -EINVAL;
705 	type = array_index_nospec(type, MAXQUOTAS);
706 	/*
707 	 * Quota not supported on this fs? Check this before s_quota_types
708 	 * since they needn't be set if quota is not supported at all.
709 	 */
710 	if (!sb->s_qcop)
711 		return -ENOSYS;
712 	if (!(sb->s_quota_types & (1 << type)))
713 		return -EINVAL;
714 
715 	ret = check_quotactl_permission(sb, type, cmd, id);
716 	if (ret < 0)
717 		return ret;
718 
719 	switch (cmd) {
720 	case Q_QUOTAON:
721 		return quota_quotaon(sb, type, id, path);
722 	case Q_QUOTAOFF:
723 		return quota_quotaoff(sb, type);
724 	case Q_GETFMT:
725 		return quota_getfmt(sb, type, addr);
726 	case Q_GETINFO:
727 		return quota_getinfo(sb, type, addr);
728 	case Q_SETINFO:
729 		return quota_setinfo(sb, type, addr);
730 	case Q_GETQUOTA:
731 		return quota_getquota(sb, type, id, addr);
732 	case Q_GETNEXTQUOTA:
733 		return quota_getnextquota(sb, type, id, addr);
734 	case Q_SETQUOTA:
735 		return quota_setquota(sb, type, id, addr);
736 	case Q_SYNC:
737 		if (!sb->s_qcop->quota_sync)
738 			return -ENOSYS;
739 		return sb->s_qcop->quota_sync(sb, type);
740 	case Q_XQUOTAON:
741 		return quota_enable(sb, addr);
742 	case Q_XQUOTAOFF:
743 		return quota_disable(sb, addr);
744 	case Q_XQUOTARM:
745 		return quota_rmxquota(sb, addr);
746 	case Q_XGETQSTAT:
747 		return quota_getxstate(sb, addr);
748 	case Q_XGETQSTATV:
749 		return quota_getxstatev(sb, addr);
750 	case Q_XSETQLIM:
751 		return quota_setxquota(sb, type, id, addr);
752 	case Q_XGETQUOTA:
753 		return quota_getxquota(sb, type, id, addr);
754 	case Q_XGETNEXTQUOTA:
755 		return quota_getnextxquota(sb, type, id, addr);
756 	case Q_XQUOTASYNC:
757 		if (sb_rdonly(sb))
758 			return -EROFS;
759 		/* XFS quotas are fully coherent now, making this call a noop */
760 		return 0;
761 	default:
762 		return -EINVAL;
763 	}
764 }
765 
766 #ifdef CONFIG_BLOCK
767 
768 /* Return 1 if 'cmd' will block on frozen filesystem */
769 static int quotactl_cmd_write(int cmd)
770 {
771 	/*
772 	 * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
773 	 * as dquot_acquire() may allocate space for new structure and OCFS2
774 	 * needs to increment on-disk use count.
775 	 */
776 	switch (cmd) {
777 	case Q_GETFMT:
778 	case Q_GETINFO:
779 	case Q_SYNC:
780 	case Q_XGETQSTAT:
781 	case Q_XGETQSTATV:
782 	case Q_XGETQUOTA:
783 	case Q_XGETNEXTQUOTA:
784 	case Q_XQUOTASYNC:
785 		return 0;
786 	}
787 	return 1;
788 }
789 #endif /* CONFIG_BLOCK */
790 
791 /* Return true if quotactl command is manipulating quota on/off state */
792 static bool quotactl_cmd_onoff(int cmd)
793 {
794 	return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
795 		 (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
796 }
797 
798 /*
799  * look up a superblock on which quota ops will be performed
800  * - use the name of a block device to find the superblock thereon
801  */
802 static struct super_block *quotactl_block(const char __user *special, int cmd)
803 {
804 #ifdef CONFIG_BLOCK
805 	struct block_device *bdev;
806 	struct super_block *sb;
807 	struct filename *tmp = getname(special);
808 
809 	if (IS_ERR(tmp))
810 		return ERR_CAST(tmp);
811 	bdev = lookup_bdev(tmp->name);
812 	putname(tmp);
813 	if (IS_ERR(bdev))
814 		return ERR_CAST(bdev);
815 	if (quotactl_cmd_onoff(cmd))
816 		sb = get_super_exclusive_thawed(bdev);
817 	else if (quotactl_cmd_write(cmd))
818 		sb = get_super_thawed(bdev);
819 	else
820 		sb = get_super(bdev);
821 	bdput(bdev);
822 	if (!sb)
823 		return ERR_PTR(-ENODEV);
824 
825 	return sb;
826 #else
827 	return ERR_PTR(-ENODEV);
828 #endif
829 }
830 
831 /*
832  * This is the system call interface. This communicates with
833  * the user-level programs. Currently this only supports diskquota
834  * calls. Maybe we need to add the process quotas etc. in the future,
835  * but we probably should use rlimits for that.
836  */
837 int kernel_quotactl(unsigned int cmd, const char __user *special,
838 		    qid_t id, void __user *addr)
839 {
840 	uint cmds, type;
841 	struct super_block *sb = NULL;
842 	struct path path, *pathp = NULL;
843 	int ret;
844 
845 	cmds = cmd >> SUBCMDSHIFT;
846 	type = cmd & SUBCMDMASK;
847 
848 	/*
849 	 * As a special case Q_SYNC can be called without a specific device.
850 	 * It will iterate all superblocks that have quota enabled and call
851 	 * the sync action on each of them.
852 	 */
853 	if (!special) {
854 		if (cmds == Q_SYNC)
855 			return quota_sync_all(type);
856 		return -ENODEV;
857 	}
858 
859 	/*
860 	 * Path for quotaon has to be resolved before grabbing superblock
861 	 * because that gets s_umount sem which is also possibly needed by path
862 	 * resolution (think about autofs) and thus deadlocks could arise.
863 	 */
864 	if (cmds == Q_QUOTAON) {
865 		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
866 		if (ret)
867 			pathp = ERR_PTR(ret);
868 		else
869 			pathp = &path;
870 	}
871 
872 	sb = quotactl_block(special, cmds);
873 	if (IS_ERR(sb)) {
874 		ret = PTR_ERR(sb);
875 		goto out;
876 	}
877 
878 	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
879 
880 	if (!quotactl_cmd_onoff(cmds))
881 		drop_super(sb);
882 	else
883 		drop_super_exclusive(sb);
884 out:
885 	if (pathp && !IS_ERR(pathp))
886 		path_put(pathp);
887 	return ret;
888 }
889 
890 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
891 		qid_t, id, void __user *, addr)
892 {
893 	return kernel_quotactl(cmd, special, id, addr);
894 }
895