xref: /openbmc/linux/fs/quota/quota.c (revision d58f75de)
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/mount.h>
21 #include <linux/writeback.h>
22 #include <linux/nospec.h>
23 #include "compat.h"
24 #include "../internal.h"
25 
26 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
27 				     qid_t id)
28 {
29 	switch (cmd) {
30 	/* these commands do not require any special privilegues */
31 	case Q_GETFMT:
32 	case Q_SYNC:
33 	case Q_GETINFO:
34 	case Q_XGETQSTAT:
35 	case Q_XGETQSTATV:
36 	case Q_XQUOTASYNC:
37 		break;
38 	/* allow to query information for dquots we "own" */
39 	case Q_GETQUOTA:
40 	case Q_XGETQUOTA:
41 		if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
42 		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
43 			break;
44 		fallthrough;
45 	default:
46 		if (!capable(CAP_SYS_ADMIN))
47 			return -EPERM;
48 	}
49 
50 	return security_quotactl(cmd, type, id, sb);
51 }
52 
53 static void quota_sync_one(struct super_block *sb, void *arg)
54 {
55 	int type = *(int *)arg;
56 
57 	if (sb->s_qcop && sb->s_qcop->quota_sync &&
58 	    (sb->s_quota_types & (1 << type)))
59 		sb->s_qcop->quota_sync(sb, type);
60 }
61 
62 static int quota_sync_all(int type)
63 {
64 	int ret;
65 
66 	ret = security_quotactl(Q_SYNC, type, 0, NULL);
67 	if (!ret)
68 		iterate_supers(quota_sync_one, &type);
69 	return ret;
70 }
71 
72 unsigned int qtype_enforce_flag(int type)
73 {
74 	switch (type) {
75 	case USRQUOTA:
76 		return FS_QUOTA_UDQ_ENFD;
77 	case GRPQUOTA:
78 		return FS_QUOTA_GDQ_ENFD;
79 	case PRJQUOTA:
80 		return FS_QUOTA_PDQ_ENFD;
81 	}
82 	return 0;
83 }
84 
85 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
86 		         const struct path *path)
87 {
88 	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
89 		return -ENOSYS;
90 	if (sb->s_qcop->quota_enable)
91 		return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
92 	if (IS_ERR(path))
93 		return PTR_ERR(path);
94 	return sb->s_qcop->quota_on(sb, type, id, path);
95 }
96 
97 static int quota_quotaoff(struct super_block *sb, int type)
98 {
99 	if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
100 		return -ENOSYS;
101 	if (sb->s_qcop->quota_disable)
102 		return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
103 	return sb->s_qcop->quota_off(sb, type);
104 }
105 
106 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
107 {
108 	__u32 fmt;
109 
110 	if (!sb_has_quota_active(sb, type))
111 		return -ESRCH;
112 	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
113 	if (copy_to_user(addr, &fmt, sizeof(fmt)))
114 		return -EFAULT;
115 	return 0;
116 }
117 
118 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
119 {
120 	struct qc_state state;
121 	struct qc_type_state *tstate;
122 	struct if_dqinfo uinfo;
123 	int ret;
124 
125 	if (!sb->s_qcop->get_state)
126 		return -ENOSYS;
127 	ret = sb->s_qcop->get_state(sb, &state);
128 	if (ret)
129 		return ret;
130 	tstate = state.s_state + type;
131 	if (!(tstate->flags & QCI_ACCT_ENABLED))
132 		return -ESRCH;
133 	memset(&uinfo, 0, sizeof(uinfo));
134 	uinfo.dqi_bgrace = tstate->spc_timelimit;
135 	uinfo.dqi_igrace = tstate->ino_timelimit;
136 	if (tstate->flags & QCI_SYSFILE)
137 		uinfo.dqi_flags |= DQF_SYS_FILE;
138 	if (tstate->flags & QCI_ROOT_SQUASH)
139 		uinfo.dqi_flags |= DQF_ROOT_SQUASH;
140 	uinfo.dqi_valid = IIF_ALL;
141 	if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
142 		return -EFAULT;
143 	return 0;
144 }
145 
146 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
147 {
148 	struct if_dqinfo info;
149 	struct qc_info qinfo;
150 
151 	if (copy_from_user(&info, addr, sizeof(info)))
152 		return -EFAULT;
153 	if (!sb->s_qcop->set_info)
154 		return -ENOSYS;
155 	if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
156 		return -EINVAL;
157 	memset(&qinfo, 0, sizeof(qinfo));
158 	if (info.dqi_valid & IIF_FLAGS) {
159 		if (info.dqi_flags & ~DQF_SETINFO_MASK)
160 			return -EINVAL;
161 		if (info.dqi_flags & DQF_ROOT_SQUASH)
162 			qinfo.i_flags |= QCI_ROOT_SQUASH;
163 		qinfo.i_fieldmask |= QC_FLAGS;
164 	}
165 	if (info.dqi_valid & IIF_BGRACE) {
166 		qinfo.i_spc_timelimit = info.dqi_bgrace;
167 		qinfo.i_fieldmask |= QC_SPC_TIMER;
168 	}
169 	if (info.dqi_valid & IIF_IGRACE) {
170 		qinfo.i_ino_timelimit = info.dqi_igrace;
171 		qinfo.i_fieldmask |= QC_INO_TIMER;
172 	}
173 	return sb->s_qcop->set_info(sb, type, &qinfo);
174 }
175 
176 static inline qsize_t qbtos(qsize_t blocks)
177 {
178 	return blocks << QIF_DQBLKSIZE_BITS;
179 }
180 
181 static inline qsize_t stoqb(qsize_t space)
182 {
183 	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
184 }
185 
186 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
187 {
188 	memset(dst, 0, sizeof(*dst));
189 	dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
190 	dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
191 	dst->dqb_curspace = src->d_space;
192 	dst->dqb_ihardlimit = src->d_ino_hardlimit;
193 	dst->dqb_isoftlimit = src->d_ino_softlimit;
194 	dst->dqb_curinodes = src->d_ino_count;
195 	dst->dqb_btime = src->d_spc_timer;
196 	dst->dqb_itime = src->d_ino_timer;
197 	dst->dqb_valid = QIF_ALL;
198 }
199 
200 static int quota_getquota(struct super_block *sb, int type, qid_t id,
201 			  void __user *addr)
202 {
203 	struct kqid qid;
204 	struct qc_dqblk fdq;
205 	struct if_dqblk idq;
206 	int ret;
207 
208 	if (!sb->s_qcop->get_dqblk)
209 		return -ENOSYS;
210 	qid = make_kqid(current_user_ns(), type, id);
211 	if (!qid_has_mapping(sb->s_user_ns, qid))
212 		return -EINVAL;
213 	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
214 	if (ret)
215 		return ret;
216 	copy_to_if_dqblk(&idq, &fdq);
217 
218 	if (compat_need_64bit_alignment_fixup()) {
219 		struct compat_if_dqblk __user *compat_dqblk = addr;
220 
221 		if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
222 			return -EFAULT;
223 		if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
224 			return -EFAULT;
225 	} else {
226 		if (copy_to_user(addr, &idq, sizeof(idq)))
227 			return -EFAULT;
228 	}
229 	return 0;
230 }
231 
232 /*
233  * Return quota for next active quota >= this id, if any exists,
234  * otherwise return -ENOENT via ->get_nextdqblk
235  */
236 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
237 			  void __user *addr)
238 {
239 	struct kqid qid;
240 	struct qc_dqblk fdq;
241 	struct if_nextdqblk idq;
242 	int ret;
243 
244 	if (!sb->s_qcop->get_nextdqblk)
245 		return -ENOSYS;
246 	qid = make_kqid(current_user_ns(), type, id);
247 	if (!qid_has_mapping(sb->s_user_ns, qid))
248 		return -EINVAL;
249 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
250 	if (ret)
251 		return ret;
252 	/* struct if_nextdqblk is a superset of struct if_dqblk */
253 	copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
254 	idq.dqb_id = from_kqid(current_user_ns(), qid);
255 	if (copy_to_user(addr, &idq, sizeof(idq)))
256 		return -EFAULT;
257 	return 0;
258 }
259 
260 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
261 {
262 	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
263 	dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
264 	dst->d_space = src->dqb_curspace;
265 	dst->d_ino_hardlimit = src->dqb_ihardlimit;
266 	dst->d_ino_softlimit = src->dqb_isoftlimit;
267 	dst->d_ino_count = src->dqb_curinodes;
268 	dst->d_spc_timer = src->dqb_btime;
269 	dst->d_ino_timer = src->dqb_itime;
270 
271 	dst->d_fieldmask = 0;
272 	if (src->dqb_valid & QIF_BLIMITS)
273 		dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
274 	if (src->dqb_valid & QIF_SPACE)
275 		dst->d_fieldmask |= QC_SPACE;
276 	if (src->dqb_valid & QIF_ILIMITS)
277 		dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
278 	if (src->dqb_valid & QIF_INODES)
279 		dst->d_fieldmask |= QC_INO_COUNT;
280 	if (src->dqb_valid & QIF_BTIME)
281 		dst->d_fieldmask |= QC_SPC_TIMER;
282 	if (src->dqb_valid & QIF_ITIME)
283 		dst->d_fieldmask |= QC_INO_TIMER;
284 }
285 
286 static int quota_setquota(struct super_block *sb, int type, qid_t id,
287 			  void __user *addr)
288 {
289 	struct qc_dqblk fdq;
290 	struct if_dqblk idq;
291 	struct kqid qid;
292 
293 	if (compat_need_64bit_alignment_fixup()) {
294 		struct compat_if_dqblk __user *compat_dqblk = addr;
295 
296 		if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
297 		    get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
298 			return -EFAULT;
299 	} else {
300 		if (copy_from_user(&idq, addr, sizeof(idq)))
301 			return -EFAULT;
302 	}
303 	if (!sb->s_qcop->set_dqblk)
304 		return -ENOSYS;
305 	qid = make_kqid(current_user_ns(), type, id);
306 	if (!qid_has_mapping(sb->s_user_ns, qid))
307 		return -EINVAL;
308 	copy_from_if_dqblk(&fdq, &idq);
309 	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
310 }
311 
312 static int quota_enable(struct super_block *sb, void __user *addr)
313 {
314 	__u32 flags;
315 
316 	if (copy_from_user(&flags, addr, sizeof(flags)))
317 		return -EFAULT;
318 	if (!sb->s_qcop->quota_enable)
319 		return -ENOSYS;
320 	return sb->s_qcop->quota_enable(sb, flags);
321 }
322 
323 static int quota_disable(struct super_block *sb, void __user *addr)
324 {
325 	__u32 flags;
326 
327 	if (copy_from_user(&flags, addr, sizeof(flags)))
328 		return -EFAULT;
329 	if (!sb->s_qcop->quota_disable)
330 		return -ENOSYS;
331 	return sb->s_qcop->quota_disable(sb, flags);
332 }
333 
334 static int quota_state_to_flags(struct qc_state *state)
335 {
336 	int flags = 0;
337 
338 	if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
339 		flags |= FS_QUOTA_UDQ_ACCT;
340 	if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
341 		flags |= FS_QUOTA_UDQ_ENFD;
342 	if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
343 		flags |= FS_QUOTA_GDQ_ACCT;
344 	if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
345 		flags |= FS_QUOTA_GDQ_ENFD;
346 	if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
347 		flags |= FS_QUOTA_PDQ_ACCT;
348 	if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
349 		flags |= FS_QUOTA_PDQ_ENFD;
350 	return flags;
351 }
352 
353 static int quota_getstate(struct super_block *sb, int type,
354 			  struct fs_quota_stat *fqs)
355 {
356 	struct qc_state state;
357 	int ret;
358 
359 	memset(&state, 0, sizeof (struct qc_state));
360 	ret = sb->s_qcop->get_state(sb, &state);
361 	if (ret < 0)
362 		return ret;
363 
364 	memset(fqs, 0, sizeof(*fqs));
365 	fqs->qs_version = FS_QSTAT_VERSION;
366 	fqs->qs_flags = quota_state_to_flags(&state);
367 	/* No quota enabled? */
368 	if (!fqs->qs_flags)
369 		return -ENOSYS;
370 	fqs->qs_incoredqs = state.s_incoredqs;
371 
372 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
373 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
374 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
375 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
376 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
377 
378 	/* Inodes may be allocated even if inactive; copy out if present */
379 	if (state.s_state[USRQUOTA].ino) {
380 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
381 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
382 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
383 	}
384 	if (state.s_state[GRPQUOTA].ino) {
385 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
386 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
387 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
388 	}
389 	if (state.s_state[PRJQUOTA].ino) {
390 		/*
391 		 * Q_XGETQSTAT doesn't have room for both group and project
392 		 * quotas.  So, allow the project quota values to be copied out
393 		 * only if there is no group quota information available.
394 		 */
395 		if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
396 			fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
397 			fqs->qs_gquota.qfs_nblks =
398 					state.s_state[PRJQUOTA].blocks;
399 			fqs->qs_gquota.qfs_nextents =
400 					state.s_state[PRJQUOTA].nextents;
401 		}
402 	}
403 	return 0;
404 }
405 
406 static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
407 		struct fs_qfilestat *from)
408 {
409 	if (copy_to_user(to, from, sizeof(*to)) ||
410 	    put_user(from->qfs_nextents, &to->qfs_nextents))
411 		return -EFAULT;
412 	return 0;
413 }
414 
415 static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
416 		struct fs_quota_stat *from)
417 {
418 	if (put_user(from->qs_version, &to->qs_version) ||
419 	    put_user(from->qs_flags, &to->qs_flags) ||
420 	    put_user(from->qs_pad, &to->qs_pad) ||
421 	    compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
422 	    compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
423 	    put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
424 	    put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
425 	    put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
426 	    put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
427 	    put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
428 	    put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
429 		return -EFAULT;
430 	return 0;
431 }
432 
433 static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
434 {
435 	struct fs_quota_stat fqs;
436 	int ret;
437 
438 	if (!sb->s_qcop->get_state)
439 		return -ENOSYS;
440 	ret = quota_getstate(sb, type, &fqs);
441 	if (ret)
442 		return ret;
443 
444 	if (compat_need_64bit_alignment_fixup())
445 		return compat_copy_fs_quota_stat(addr, &fqs);
446 	if (copy_to_user(addr, &fqs, sizeof(fqs)))
447 		return -EFAULT;
448 	return 0;
449 }
450 
451 static int quota_getstatev(struct super_block *sb, int type,
452 			   struct fs_quota_statv *fqs)
453 {
454 	struct qc_state state;
455 	int ret;
456 
457 	memset(&state, 0, sizeof (struct qc_state));
458 	ret = sb->s_qcop->get_state(sb, &state);
459 	if (ret < 0)
460 		return ret;
461 
462 	memset(fqs, 0, sizeof(*fqs));
463 	fqs->qs_version = FS_QSTAT_VERSION;
464 	fqs->qs_flags = quota_state_to_flags(&state);
465 	/* No quota enabled? */
466 	if (!fqs->qs_flags)
467 		return -ENOSYS;
468 	fqs->qs_incoredqs = state.s_incoredqs;
469 
470 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
471 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
472 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
473 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
474 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
475 	fqs->qs_rtbwarnlimit = state.s_state[type].rt_spc_warnlimit;
476 
477 	/* Inodes may be allocated even if inactive; copy out if present */
478 	if (state.s_state[USRQUOTA].ino) {
479 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
480 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
481 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
482 	}
483 	if (state.s_state[GRPQUOTA].ino) {
484 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
485 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
486 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
487 	}
488 	if (state.s_state[PRJQUOTA].ino) {
489 		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
490 		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
491 		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
492 	}
493 	return 0;
494 }
495 
496 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
497 {
498 	struct fs_quota_statv fqs;
499 	int ret;
500 
501 	if (!sb->s_qcop->get_state)
502 		return -ENOSYS;
503 
504 	memset(&fqs, 0, sizeof(fqs));
505 	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
506 		return -EFAULT;
507 
508 	/* If this kernel doesn't support user specified version, fail */
509 	switch (fqs.qs_version) {
510 	case FS_QSTATV_VERSION1:
511 		break;
512 	default:
513 		return -EINVAL;
514 	}
515 	ret = quota_getstatev(sb, type, &fqs);
516 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
517 		return -EFAULT;
518 	return ret;
519 }
520 
521 /*
522  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
523  * out of there as xfsprogs rely on definitions being in that header file. So
524  * just define same functions here for quota purposes.
525  */
526 #define XFS_BB_SHIFT 9
527 
528 static inline u64 quota_bbtob(u64 blocks)
529 {
530 	return blocks << XFS_BB_SHIFT;
531 }
532 
533 static inline u64 quota_btobb(u64 bytes)
534 {
535 	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
536 }
537 
538 static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
539 		__s32 timer, __s8 timer_hi)
540 {
541 	if (d->d_fieldmask & FS_DQ_BIGTIME)
542 		return (u32)timer | (s64)timer_hi << 32;
543 	return timer;
544 }
545 
546 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
547 {
548 	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
549 	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
550 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
551 	dst->d_ino_softlimit = src->d_ino_softlimit;
552 	dst->d_space = quota_bbtob(src->d_bcount);
553 	dst->d_ino_count = src->d_icount;
554 	dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
555 						  src->d_itimer_hi);
556 	dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
557 						  src->d_btimer_hi);
558 	dst->d_ino_warns = src->d_iwarns;
559 	dst->d_spc_warns = src->d_bwarns;
560 	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
561 	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
562 	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
563 	dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
564 						     src->d_rtbtimer_hi);
565 	dst->d_rt_spc_warns = src->d_rtbwarns;
566 	dst->d_fieldmask = 0;
567 	if (src->d_fieldmask & FS_DQ_ISOFT)
568 		dst->d_fieldmask |= QC_INO_SOFT;
569 	if (src->d_fieldmask & FS_DQ_IHARD)
570 		dst->d_fieldmask |= QC_INO_HARD;
571 	if (src->d_fieldmask & FS_DQ_BSOFT)
572 		dst->d_fieldmask |= QC_SPC_SOFT;
573 	if (src->d_fieldmask & FS_DQ_BHARD)
574 		dst->d_fieldmask |= QC_SPC_HARD;
575 	if (src->d_fieldmask & FS_DQ_RTBSOFT)
576 		dst->d_fieldmask |= QC_RT_SPC_SOFT;
577 	if (src->d_fieldmask & FS_DQ_RTBHARD)
578 		dst->d_fieldmask |= QC_RT_SPC_HARD;
579 	if (src->d_fieldmask & FS_DQ_BTIMER)
580 		dst->d_fieldmask |= QC_SPC_TIMER;
581 	if (src->d_fieldmask & FS_DQ_ITIMER)
582 		dst->d_fieldmask |= QC_INO_TIMER;
583 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
584 		dst->d_fieldmask |= QC_RT_SPC_TIMER;
585 	if (src->d_fieldmask & FS_DQ_BWARNS)
586 		dst->d_fieldmask |= QC_SPC_WARNS;
587 	if (src->d_fieldmask & FS_DQ_IWARNS)
588 		dst->d_fieldmask |= QC_INO_WARNS;
589 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
590 		dst->d_fieldmask |= QC_RT_SPC_WARNS;
591 	if (src->d_fieldmask & FS_DQ_BCOUNT)
592 		dst->d_fieldmask |= QC_SPACE;
593 	if (src->d_fieldmask & FS_DQ_ICOUNT)
594 		dst->d_fieldmask |= QC_INO_COUNT;
595 	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
596 		dst->d_fieldmask |= QC_RT_SPACE;
597 }
598 
599 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
600 				       struct fs_disk_quota *src)
601 {
602 	memset(dst, 0, sizeof(*dst));
603 	dst->i_spc_timelimit = src->d_btimer;
604 	dst->i_ino_timelimit = src->d_itimer;
605 	dst->i_rt_spc_timelimit = src->d_rtbtimer;
606 	dst->i_ino_warnlimit = src->d_iwarns;
607 	dst->i_spc_warnlimit = src->d_bwarns;
608 	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
609 	if (src->d_fieldmask & FS_DQ_BWARNS)
610 		dst->i_fieldmask |= QC_SPC_WARNS;
611 	if (src->d_fieldmask & FS_DQ_IWARNS)
612 		dst->i_fieldmask |= QC_INO_WARNS;
613 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
614 		dst->i_fieldmask |= QC_RT_SPC_WARNS;
615 	if (src->d_fieldmask & FS_DQ_BTIMER)
616 		dst->i_fieldmask |= QC_SPC_TIMER;
617 	if (src->d_fieldmask & FS_DQ_ITIMER)
618 		dst->i_fieldmask |= QC_INO_TIMER;
619 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
620 		dst->i_fieldmask |= QC_RT_SPC_TIMER;
621 }
622 
623 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
624 			   void __user *addr)
625 {
626 	struct fs_disk_quota fdq;
627 	struct qc_dqblk qdq;
628 	struct kqid qid;
629 
630 	if (copy_from_user(&fdq, addr, sizeof(fdq)))
631 		return -EFAULT;
632 	if (!sb->s_qcop->set_dqblk)
633 		return -ENOSYS;
634 	qid = make_kqid(current_user_ns(), type, id);
635 	if (!qid_has_mapping(sb->s_user_ns, qid))
636 		return -EINVAL;
637 	/* Are we actually setting timer / warning limits for all users? */
638 	if (from_kqid(sb->s_user_ns, qid) == 0 &&
639 	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
640 		struct qc_info qinfo;
641 		int ret;
642 
643 		if (!sb->s_qcop->set_info)
644 			return -EINVAL;
645 		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
646 		ret = sb->s_qcop->set_info(sb, type, &qinfo);
647 		if (ret)
648 			return ret;
649 		/* These are already done */
650 		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
651 	}
652 	copy_from_xfs_dqblk(&qdq, &fdq);
653 	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
654 }
655 
656 static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
657 		__s32 *timer_lo, __s8 *timer_hi, s64 timer)
658 {
659 	*timer_lo = timer;
660 	if (d->d_fieldmask & FS_DQ_BIGTIME)
661 		*timer_hi = timer >> 32;
662 }
663 
664 static inline bool want_bigtime(s64 timer)
665 {
666 	return timer > S32_MAX || timer < S32_MIN;
667 }
668 
669 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
670 			      int type, qid_t id)
671 {
672 	memset(dst, 0, sizeof(*dst));
673 	if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
674 	    want_bigtime(src->d_rt_spc_timer))
675 		dst->d_fieldmask |= FS_DQ_BIGTIME;
676 	dst->d_version = FS_DQUOT_VERSION;
677 	dst->d_id = id;
678 	if (type == USRQUOTA)
679 		dst->d_flags = FS_USER_QUOTA;
680 	else if (type == PRJQUOTA)
681 		dst->d_flags = FS_PROJ_QUOTA;
682 	else
683 		dst->d_flags = FS_GROUP_QUOTA;
684 	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
685 	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
686 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
687 	dst->d_ino_softlimit = src->d_ino_softlimit;
688 	dst->d_bcount = quota_btobb(src->d_space);
689 	dst->d_icount = src->d_ino_count;
690 	copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
691 			     src->d_ino_timer);
692 	copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
693 			     src->d_spc_timer);
694 	dst->d_iwarns = src->d_ino_warns;
695 	dst->d_bwarns = src->d_spc_warns;
696 	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
697 	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
698 	dst->d_rtbcount = quota_btobb(src->d_rt_space);
699 	copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
700 			     src->d_rt_spc_timer);
701 	dst->d_rtbwarns = src->d_rt_spc_warns;
702 }
703 
704 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
705 			   void __user *addr)
706 {
707 	struct fs_disk_quota fdq;
708 	struct qc_dqblk qdq;
709 	struct kqid qid;
710 	int ret;
711 
712 	if (!sb->s_qcop->get_dqblk)
713 		return -ENOSYS;
714 	qid = make_kqid(current_user_ns(), type, id);
715 	if (!qid_has_mapping(sb->s_user_ns, qid))
716 		return -EINVAL;
717 	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
718 	if (ret)
719 		return ret;
720 	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
721 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
722 		return -EFAULT;
723 	return ret;
724 }
725 
726 /*
727  * Return quota for next active quota >= this id, if any exists,
728  * otherwise return -ENOENT via ->get_nextdqblk.
729  */
730 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
731 			    void __user *addr)
732 {
733 	struct fs_disk_quota fdq;
734 	struct qc_dqblk qdq;
735 	struct kqid qid;
736 	qid_t id_out;
737 	int ret;
738 
739 	if (!sb->s_qcop->get_nextdqblk)
740 		return -ENOSYS;
741 	qid = make_kqid(current_user_ns(), type, id);
742 	if (!qid_has_mapping(sb->s_user_ns, qid))
743 		return -EINVAL;
744 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
745 	if (ret)
746 		return ret;
747 	id_out = from_kqid(current_user_ns(), qid);
748 	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
749 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
750 		return -EFAULT;
751 	return ret;
752 }
753 
754 static int quota_rmxquota(struct super_block *sb, void __user *addr)
755 {
756 	__u32 flags;
757 
758 	if (copy_from_user(&flags, addr, sizeof(flags)))
759 		return -EFAULT;
760 	if (!sb->s_qcop->rm_xquota)
761 		return -ENOSYS;
762 	return sb->s_qcop->rm_xquota(sb, flags);
763 }
764 
765 /* Copy parameters and call proper function */
766 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
767 		       void __user *addr, const struct path *path)
768 {
769 	int ret;
770 
771 	type = array_index_nospec(type, MAXQUOTAS);
772 	/*
773 	 * Quota not supported on this fs? Check this before s_quota_types
774 	 * since they needn't be set if quota is not supported at all.
775 	 */
776 	if (!sb->s_qcop)
777 		return -ENOSYS;
778 	if (!(sb->s_quota_types & (1 << type)))
779 		return -EINVAL;
780 
781 	ret = check_quotactl_permission(sb, type, cmd, id);
782 	if (ret < 0)
783 		return ret;
784 
785 	switch (cmd) {
786 	case Q_QUOTAON:
787 		return quota_quotaon(sb, type, id, path);
788 	case Q_QUOTAOFF:
789 		return quota_quotaoff(sb, type);
790 	case Q_GETFMT:
791 		return quota_getfmt(sb, type, addr);
792 	case Q_GETINFO:
793 		return quota_getinfo(sb, type, addr);
794 	case Q_SETINFO:
795 		return quota_setinfo(sb, type, addr);
796 	case Q_GETQUOTA:
797 		return quota_getquota(sb, type, id, addr);
798 	case Q_GETNEXTQUOTA:
799 		return quota_getnextquota(sb, type, id, addr);
800 	case Q_SETQUOTA:
801 		return quota_setquota(sb, type, id, addr);
802 	case Q_SYNC:
803 		if (!sb->s_qcop->quota_sync)
804 			return -ENOSYS;
805 		return sb->s_qcop->quota_sync(sb, type);
806 	case Q_XQUOTAON:
807 		return quota_enable(sb, addr);
808 	case Q_XQUOTAOFF:
809 		return quota_disable(sb, addr);
810 	case Q_XQUOTARM:
811 		return quota_rmxquota(sb, addr);
812 	case Q_XGETQSTAT:
813 		return quota_getxstate(sb, type, addr);
814 	case Q_XGETQSTATV:
815 		return quota_getxstatev(sb, type, addr);
816 	case Q_XSETQLIM:
817 		return quota_setxquota(sb, type, id, addr);
818 	case Q_XGETQUOTA:
819 		return quota_getxquota(sb, type, id, addr);
820 	case Q_XGETNEXTQUOTA:
821 		return quota_getnextxquota(sb, type, id, addr);
822 	case Q_XQUOTASYNC:
823 		if (sb_rdonly(sb))
824 			return -EROFS;
825 		/* XFS quotas are fully coherent now, making this call a noop */
826 		return 0;
827 	default:
828 		return -EINVAL;
829 	}
830 }
831 
832 /* Return 1 if 'cmd' will block on frozen filesystem */
833 static int quotactl_cmd_write(int cmd)
834 {
835 	/*
836 	 * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
837 	 * as dquot_acquire() may allocate space for new structure and OCFS2
838 	 * needs to increment on-disk use count.
839 	 */
840 	switch (cmd) {
841 	case Q_GETFMT:
842 	case Q_GETINFO:
843 	case Q_SYNC:
844 	case Q_XGETQSTAT:
845 	case Q_XGETQSTATV:
846 	case Q_XGETQUOTA:
847 	case Q_XGETNEXTQUOTA:
848 	case Q_XQUOTASYNC:
849 		return 0;
850 	}
851 	return 1;
852 }
853 
854 /* Return true if quotactl command is manipulating quota on/off state */
855 static bool quotactl_cmd_onoff(int cmd)
856 {
857 	return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
858 		 (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
859 }
860 
861 /*
862  * look up a superblock on which quota ops will be performed
863  * - use the name of a block device to find the superblock thereon
864  */
865 static struct super_block *quotactl_block(const char __user *special, int cmd)
866 {
867 #ifdef CONFIG_BLOCK
868 	struct super_block *sb;
869 	struct filename *tmp = getname(special);
870 	bool excl = false, thawed = false;
871 	int error;
872 	dev_t dev;
873 
874 	if (IS_ERR(tmp))
875 		return ERR_CAST(tmp);
876 	error = lookup_bdev(tmp->name, &dev);
877 	putname(tmp);
878 	if (error)
879 		return ERR_PTR(error);
880 
881 	if (quotactl_cmd_onoff(cmd)) {
882 		excl = true;
883 		thawed = true;
884 	} else if (quotactl_cmd_write(cmd)) {
885 		thawed = true;
886 	}
887 
888 retry:
889 	sb = user_get_super(dev, excl);
890 	if (!sb)
891 		return ERR_PTR(-ENODEV);
892 	if (thawed && sb->s_writers.frozen != SB_UNFROZEN) {
893 		if (excl)
894 			up_write(&sb->s_umount);
895 		else
896 			up_read(&sb->s_umount);
897 		wait_event(sb->s_writers.wait_unfrozen,
898 			   sb->s_writers.frozen == SB_UNFROZEN);
899 		put_super(sb);
900 		goto retry;
901 	}
902 	return sb;
903 
904 #else
905 	return ERR_PTR(-ENODEV);
906 #endif
907 }
908 
909 /*
910  * This is the system call interface. This communicates with
911  * the user-level programs. Currently this only supports diskquota
912  * calls. Maybe we need to add the process quotas etc. in the future,
913  * but we probably should use rlimits for that.
914  */
915 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
916 		qid_t, id, void __user *, addr)
917 {
918 	uint cmds, type;
919 	struct super_block *sb = NULL;
920 	struct path path, *pathp = NULL;
921 	int ret;
922 
923 	cmds = cmd >> SUBCMDSHIFT;
924 	type = cmd & SUBCMDMASK;
925 
926 	if (type >= MAXQUOTAS)
927 		return -EINVAL;
928 
929 	/*
930 	 * As a special case Q_SYNC can be called without a specific device.
931 	 * It will iterate all superblocks that have quota enabled and call
932 	 * the sync action on each of them.
933 	 */
934 	if (!special) {
935 		if (cmds == Q_SYNC)
936 			return quota_sync_all(type);
937 		return -ENODEV;
938 	}
939 
940 	/*
941 	 * Path for quotaon has to be resolved before grabbing superblock
942 	 * because that gets s_umount sem which is also possibly needed by path
943 	 * resolution (think about autofs) and thus deadlocks could arise.
944 	 */
945 	if (cmds == Q_QUOTAON) {
946 		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
947 		if (ret)
948 			pathp = ERR_PTR(ret);
949 		else
950 			pathp = &path;
951 	}
952 
953 	sb = quotactl_block(special, cmds);
954 	if (IS_ERR(sb)) {
955 		ret = PTR_ERR(sb);
956 		goto out;
957 	}
958 
959 	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
960 
961 	if (!quotactl_cmd_onoff(cmds))
962 		drop_super(sb);
963 	else
964 		drop_super_exclusive(sb);
965 out:
966 	if (pathp && !IS_ERR(pathp))
967 		path_put(pathp);
968 	return ret;
969 }
970 
971 SYSCALL_DEFINE4(quotactl_path, unsigned int, cmd, const char __user *,
972 		mountpoint, qid_t, id, void __user *, addr)
973 {
974 	struct super_block *sb;
975 	struct path mountpath;
976 	unsigned int cmds = cmd >> SUBCMDSHIFT;
977 	unsigned int type = cmd & SUBCMDMASK;
978 	int ret;
979 
980 	if (type >= MAXQUOTAS)
981 		return -EINVAL;
982 
983 	ret = user_path_at(AT_FDCWD, mountpoint,
984 			     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);
985 	if (ret)
986 		return ret;
987 
988 	sb = mountpath.mnt->mnt_sb;
989 
990 	if (quotactl_cmd_write(cmds)) {
991 		ret = mnt_want_write(mountpath.mnt);
992 		if (ret)
993 			goto out;
994 	}
995 
996 	if (quotactl_cmd_onoff(cmds))
997 		down_write(&sb->s_umount);
998 	else
999 		down_read(&sb->s_umount);
1000 
1001 	ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
1002 
1003 	if (quotactl_cmd_onoff(cmds))
1004 		up_write(&sb->s_umount);
1005 	else
1006 		up_read(&sb->s_umount);
1007 
1008 	if (quotactl_cmd_write(cmds))
1009 		mnt_drop_write(mountpath.mnt);
1010 out:
1011 	path_put(&mountpath);
1012 
1013 	return ret;
1014 }
1015