xref: /openbmc/linux/fs/quota/quota.c (revision 842ed298)
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 #include "compat.h"
23 #include "../internal.h"
24 
25 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
26 				     qid_t id)
27 {
28 	switch (cmd) {
29 	/* these commands do not require any special privilegues */
30 	case Q_GETFMT:
31 	case Q_SYNC:
32 	case Q_GETINFO:
33 	case Q_XGETQSTAT:
34 	case Q_XGETQSTATV:
35 	case Q_XQUOTASYNC:
36 		break;
37 	/* allow to query information for dquots we "own" */
38 	case Q_GETQUOTA:
39 	case Q_XGETQUOTA:
40 		if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
41 		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
42 			break;
43 		fallthrough;
44 	default:
45 		if (!capable(CAP_SYS_ADMIN))
46 			return -EPERM;
47 	}
48 
49 	return security_quotactl(cmd, type, id, sb);
50 }
51 
52 static void quota_sync_one(struct super_block *sb, void *arg)
53 {
54 	int type = *(int *)arg;
55 
56 	if (sb->s_qcop && sb->s_qcop->quota_sync &&
57 	    (sb->s_quota_types & (1 << type)))
58 		sb->s_qcop->quota_sync(sb, type);
59 }
60 
61 static int quota_sync_all(int type)
62 {
63 	int ret;
64 
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 
217 	if (compat_need_64bit_alignment_fixup()) {
218 		struct compat_if_dqblk __user *compat_dqblk = addr;
219 
220 		if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
221 			return -EFAULT;
222 		if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
223 			return -EFAULT;
224 	} else {
225 		if (copy_to_user(addr, &idq, sizeof(idq)))
226 			return -EFAULT;
227 	}
228 	return 0;
229 }
230 
231 /*
232  * Return quota for next active quota >= this id, if any exists,
233  * otherwise return -ENOENT via ->get_nextdqblk
234  */
235 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
236 			  void __user *addr)
237 {
238 	struct kqid qid;
239 	struct qc_dqblk fdq;
240 	struct if_nextdqblk idq;
241 	int ret;
242 
243 	if (!sb->s_qcop->get_nextdqblk)
244 		return -ENOSYS;
245 	qid = make_kqid(current_user_ns(), type, id);
246 	if (!qid_has_mapping(sb->s_user_ns, qid))
247 		return -EINVAL;
248 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
249 	if (ret)
250 		return ret;
251 	/* struct if_nextdqblk is a superset of struct if_dqblk */
252 	copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
253 	idq.dqb_id = from_kqid(current_user_ns(), qid);
254 	if (copy_to_user(addr, &idq, sizeof(idq)))
255 		return -EFAULT;
256 	return 0;
257 }
258 
259 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
260 {
261 	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
262 	dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
263 	dst->d_space = src->dqb_curspace;
264 	dst->d_ino_hardlimit = src->dqb_ihardlimit;
265 	dst->d_ino_softlimit = src->dqb_isoftlimit;
266 	dst->d_ino_count = src->dqb_curinodes;
267 	dst->d_spc_timer = src->dqb_btime;
268 	dst->d_ino_timer = src->dqb_itime;
269 
270 	dst->d_fieldmask = 0;
271 	if (src->dqb_valid & QIF_BLIMITS)
272 		dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
273 	if (src->dqb_valid & QIF_SPACE)
274 		dst->d_fieldmask |= QC_SPACE;
275 	if (src->dqb_valid & QIF_ILIMITS)
276 		dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
277 	if (src->dqb_valid & QIF_INODES)
278 		dst->d_fieldmask |= QC_INO_COUNT;
279 	if (src->dqb_valid & QIF_BTIME)
280 		dst->d_fieldmask |= QC_SPC_TIMER;
281 	if (src->dqb_valid & QIF_ITIME)
282 		dst->d_fieldmask |= QC_INO_TIMER;
283 }
284 
285 static int quota_setquota(struct super_block *sb, int type, qid_t id,
286 			  void __user *addr)
287 {
288 	struct qc_dqblk fdq;
289 	struct if_dqblk idq;
290 	struct kqid qid;
291 
292 	if (compat_need_64bit_alignment_fixup()) {
293 		struct compat_if_dqblk __user *compat_dqblk = addr;
294 
295 		if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
296 		    get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
297 			return -EFAULT;
298 	} else {
299 		if (copy_from_user(&idq, addr, sizeof(idq)))
300 			return -EFAULT;
301 	}
302 	if (!sb->s_qcop->set_dqblk)
303 		return -ENOSYS;
304 	qid = make_kqid(current_user_ns(), type, id);
305 	if (!qid_has_mapping(sb->s_user_ns, qid))
306 		return -EINVAL;
307 	copy_from_if_dqblk(&fdq, &idq);
308 	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
309 }
310 
311 static int quota_enable(struct super_block *sb, void __user *addr)
312 {
313 	__u32 flags;
314 
315 	if (copy_from_user(&flags, addr, sizeof(flags)))
316 		return -EFAULT;
317 	if (!sb->s_qcop->quota_enable)
318 		return -ENOSYS;
319 	return sb->s_qcop->quota_enable(sb, flags);
320 }
321 
322 static int quota_disable(struct super_block *sb, void __user *addr)
323 {
324 	__u32 flags;
325 
326 	if (copy_from_user(&flags, addr, sizeof(flags)))
327 		return -EFAULT;
328 	if (!sb->s_qcop->quota_disable)
329 		return -ENOSYS;
330 	return sb->s_qcop->quota_disable(sb, flags);
331 }
332 
333 static int quota_state_to_flags(struct qc_state *state)
334 {
335 	int flags = 0;
336 
337 	if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
338 		flags |= FS_QUOTA_UDQ_ACCT;
339 	if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
340 		flags |= FS_QUOTA_UDQ_ENFD;
341 	if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
342 		flags |= FS_QUOTA_GDQ_ACCT;
343 	if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
344 		flags |= FS_QUOTA_GDQ_ENFD;
345 	if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
346 		flags |= FS_QUOTA_PDQ_ACCT;
347 	if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
348 		flags |= FS_QUOTA_PDQ_ENFD;
349 	return flags;
350 }
351 
352 static int quota_getstate(struct super_block *sb, int type,
353 			  struct fs_quota_stat *fqs)
354 {
355 	struct qc_state state;
356 	int ret;
357 
358 	memset(&state, 0, sizeof (struct qc_state));
359 	ret = sb->s_qcop->get_state(sb, &state);
360 	if (ret < 0)
361 		return ret;
362 
363 	memset(fqs, 0, sizeof(*fqs));
364 	fqs->qs_version = FS_QSTAT_VERSION;
365 	fqs->qs_flags = quota_state_to_flags(&state);
366 	/* No quota enabled? */
367 	if (!fqs->qs_flags)
368 		return -ENOSYS;
369 	fqs->qs_incoredqs = state.s_incoredqs;
370 
371 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
372 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
373 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
374 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
375 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
376 
377 	/* Inodes may be allocated even if inactive; copy out if present */
378 	if (state.s_state[USRQUOTA].ino) {
379 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
380 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
381 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
382 	}
383 	if (state.s_state[GRPQUOTA].ino) {
384 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
385 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
386 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
387 	}
388 	if (state.s_state[PRJQUOTA].ino) {
389 		/*
390 		 * Q_XGETQSTAT doesn't have room for both group and project
391 		 * quotas.  So, allow the project quota values to be copied out
392 		 * only if there is no group quota information available.
393 		 */
394 		if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
395 			fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
396 			fqs->qs_gquota.qfs_nblks =
397 					state.s_state[PRJQUOTA].blocks;
398 			fqs->qs_gquota.qfs_nextents =
399 					state.s_state[PRJQUOTA].nextents;
400 		}
401 	}
402 	return 0;
403 }
404 
405 static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
406 		struct fs_qfilestat *from)
407 {
408 	if (copy_to_user(to, from, sizeof(*to)) ||
409 	    put_user(from->qfs_nextents, &to->qfs_nextents))
410 		return -EFAULT;
411 	return 0;
412 }
413 
414 static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
415 		struct fs_quota_stat *from)
416 {
417 	if (put_user(from->qs_version, &to->qs_version) ||
418 	    put_user(from->qs_flags, &to->qs_flags) ||
419 	    put_user(from->qs_pad, &to->qs_pad) ||
420 	    compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
421 	    compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
422 	    put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
423 	    put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
424 	    put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
425 	    put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
426 	    put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
427 	    put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
428 		return -EFAULT;
429 	return 0;
430 }
431 
432 static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
433 {
434 	struct fs_quota_stat fqs;
435 	int ret;
436 
437 	if (!sb->s_qcop->get_state)
438 		return -ENOSYS;
439 	ret = quota_getstate(sb, type, &fqs);
440 	if (ret)
441 		return ret;
442 
443 	if (compat_need_64bit_alignment_fixup())
444 		return compat_copy_fs_quota_stat(addr, &fqs);
445 	if (copy_to_user(addr, &fqs, sizeof(fqs)))
446 		return -EFAULT;
447 	return 0;
448 }
449 
450 static int quota_getstatev(struct super_block *sb, int type,
451 			   struct fs_quota_statv *fqs)
452 {
453 	struct qc_state state;
454 	int ret;
455 
456 	memset(&state, 0, sizeof (struct qc_state));
457 	ret = sb->s_qcop->get_state(sb, &state);
458 	if (ret < 0)
459 		return ret;
460 
461 	memset(fqs, 0, sizeof(*fqs));
462 	fqs->qs_version = FS_QSTAT_VERSION;
463 	fqs->qs_flags = quota_state_to_flags(&state);
464 	/* No quota enabled? */
465 	if (!fqs->qs_flags)
466 		return -ENOSYS;
467 	fqs->qs_incoredqs = state.s_incoredqs;
468 
469 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
470 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
471 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
472 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
473 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
474 
475 	/* Inodes may be allocated even if inactive; copy out if present */
476 	if (state.s_state[USRQUOTA].ino) {
477 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
478 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
479 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
480 	}
481 	if (state.s_state[GRPQUOTA].ino) {
482 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
483 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
484 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
485 	}
486 	if (state.s_state[PRJQUOTA].ino) {
487 		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
488 		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
489 		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
490 	}
491 	return 0;
492 }
493 
494 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
495 {
496 	struct fs_quota_statv fqs;
497 	int ret;
498 
499 	if (!sb->s_qcop->get_state)
500 		return -ENOSYS;
501 
502 	memset(&fqs, 0, sizeof(fqs));
503 	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
504 		return -EFAULT;
505 
506 	/* If this kernel doesn't support user specified version, fail */
507 	switch (fqs.qs_version) {
508 	case FS_QSTATV_VERSION1:
509 		break;
510 	default:
511 		return -EINVAL;
512 	}
513 	ret = quota_getstatev(sb, type, &fqs);
514 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
515 		return -EFAULT;
516 	return ret;
517 }
518 
519 /*
520  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
521  * out of there as xfsprogs rely on definitions being in that header file. So
522  * just define same functions here for quota purposes.
523  */
524 #define XFS_BB_SHIFT 9
525 
526 static inline u64 quota_bbtob(u64 blocks)
527 {
528 	return blocks << XFS_BB_SHIFT;
529 }
530 
531 static inline u64 quota_btobb(u64 bytes)
532 {
533 	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
534 }
535 
536 static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
537 		__s32 timer, __s8 timer_hi)
538 {
539 	if (d->d_fieldmask & FS_DQ_BIGTIME)
540 		return (u32)timer | (s64)timer_hi << 32;
541 	return timer;
542 }
543 
544 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
545 {
546 	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
547 	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
548 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
549 	dst->d_ino_softlimit = src->d_ino_softlimit;
550 	dst->d_space = quota_bbtob(src->d_bcount);
551 	dst->d_ino_count = src->d_icount;
552 	dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
553 						  src->d_itimer_hi);
554 	dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
555 						  src->d_btimer_hi);
556 	dst->d_ino_warns = src->d_iwarns;
557 	dst->d_spc_warns = src->d_bwarns;
558 	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
559 	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
560 	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
561 	dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
562 						     src->d_rtbtimer_hi);
563 	dst->d_rt_spc_warns = src->d_rtbwarns;
564 	dst->d_fieldmask = 0;
565 	if (src->d_fieldmask & FS_DQ_ISOFT)
566 		dst->d_fieldmask |= QC_INO_SOFT;
567 	if (src->d_fieldmask & FS_DQ_IHARD)
568 		dst->d_fieldmask |= QC_INO_HARD;
569 	if (src->d_fieldmask & FS_DQ_BSOFT)
570 		dst->d_fieldmask |= QC_SPC_SOFT;
571 	if (src->d_fieldmask & FS_DQ_BHARD)
572 		dst->d_fieldmask |= QC_SPC_HARD;
573 	if (src->d_fieldmask & FS_DQ_RTBSOFT)
574 		dst->d_fieldmask |= QC_RT_SPC_SOFT;
575 	if (src->d_fieldmask & FS_DQ_RTBHARD)
576 		dst->d_fieldmask |= QC_RT_SPC_HARD;
577 	if (src->d_fieldmask & FS_DQ_BTIMER)
578 		dst->d_fieldmask |= QC_SPC_TIMER;
579 	if (src->d_fieldmask & FS_DQ_ITIMER)
580 		dst->d_fieldmask |= QC_INO_TIMER;
581 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
582 		dst->d_fieldmask |= QC_RT_SPC_TIMER;
583 	if (src->d_fieldmask & FS_DQ_BWARNS)
584 		dst->d_fieldmask |= QC_SPC_WARNS;
585 	if (src->d_fieldmask & FS_DQ_IWARNS)
586 		dst->d_fieldmask |= QC_INO_WARNS;
587 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
588 		dst->d_fieldmask |= QC_RT_SPC_WARNS;
589 	if (src->d_fieldmask & FS_DQ_BCOUNT)
590 		dst->d_fieldmask |= QC_SPACE;
591 	if (src->d_fieldmask & FS_DQ_ICOUNT)
592 		dst->d_fieldmask |= QC_INO_COUNT;
593 	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
594 		dst->d_fieldmask |= QC_RT_SPACE;
595 }
596 
597 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
598 				       struct fs_disk_quota *src)
599 {
600 	memset(dst, 0, sizeof(*dst));
601 	dst->i_spc_timelimit = src->d_btimer;
602 	dst->i_ino_timelimit = src->d_itimer;
603 	dst->i_rt_spc_timelimit = src->d_rtbtimer;
604 	dst->i_ino_warnlimit = src->d_iwarns;
605 	dst->i_spc_warnlimit = src->d_bwarns;
606 	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
607 	if (src->d_fieldmask & FS_DQ_BWARNS)
608 		dst->i_fieldmask |= QC_SPC_WARNS;
609 	if (src->d_fieldmask & FS_DQ_IWARNS)
610 		dst->i_fieldmask |= QC_INO_WARNS;
611 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
612 		dst->i_fieldmask |= QC_RT_SPC_WARNS;
613 	if (src->d_fieldmask & FS_DQ_BTIMER)
614 		dst->i_fieldmask |= QC_SPC_TIMER;
615 	if (src->d_fieldmask & FS_DQ_ITIMER)
616 		dst->i_fieldmask |= QC_INO_TIMER;
617 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
618 		dst->i_fieldmask |= QC_RT_SPC_TIMER;
619 }
620 
621 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
622 			   void __user *addr)
623 {
624 	struct fs_disk_quota fdq;
625 	struct qc_dqblk qdq;
626 	struct kqid qid;
627 
628 	if (copy_from_user(&fdq, addr, sizeof(fdq)))
629 		return -EFAULT;
630 	if (!sb->s_qcop->set_dqblk)
631 		return -ENOSYS;
632 	qid = make_kqid(current_user_ns(), type, id);
633 	if (!qid_has_mapping(sb->s_user_ns, qid))
634 		return -EINVAL;
635 	/* Are we actually setting timer / warning limits for all users? */
636 	if (from_kqid(sb->s_user_ns, qid) == 0 &&
637 	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
638 		struct qc_info qinfo;
639 		int ret;
640 
641 		if (!sb->s_qcop->set_info)
642 			return -EINVAL;
643 		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
644 		ret = sb->s_qcop->set_info(sb, type, &qinfo);
645 		if (ret)
646 			return ret;
647 		/* These are already done */
648 		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
649 	}
650 	copy_from_xfs_dqblk(&qdq, &fdq);
651 	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
652 }
653 
654 static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
655 		__s32 *timer_lo, __s8 *timer_hi, s64 timer)
656 {
657 	*timer_lo = timer;
658 	if (d->d_fieldmask & FS_DQ_BIGTIME)
659 		*timer_hi = timer >> 32;
660 }
661 
662 static inline bool want_bigtime(s64 timer)
663 {
664 	return timer > S32_MAX || timer < S32_MIN;
665 }
666 
667 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
668 			      int type, qid_t id)
669 {
670 	memset(dst, 0, sizeof(*dst));
671 	if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
672 	    want_bigtime(src->d_rt_spc_timer))
673 		dst->d_fieldmask |= FS_DQ_BIGTIME;
674 	dst->d_version = FS_DQUOT_VERSION;
675 	dst->d_id = id;
676 	if (type == USRQUOTA)
677 		dst->d_flags = FS_USER_QUOTA;
678 	else if (type == PRJQUOTA)
679 		dst->d_flags = FS_PROJ_QUOTA;
680 	else
681 		dst->d_flags = FS_GROUP_QUOTA;
682 	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
683 	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
684 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
685 	dst->d_ino_softlimit = src->d_ino_softlimit;
686 	dst->d_bcount = quota_btobb(src->d_space);
687 	dst->d_icount = src->d_ino_count;
688 	copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
689 			     src->d_ino_timer);
690 	copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
691 			     src->d_spc_timer);
692 	dst->d_iwarns = src->d_ino_warns;
693 	dst->d_bwarns = src->d_spc_warns;
694 	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
695 	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
696 	dst->d_rtbcount = quota_btobb(src->d_rt_space);
697 	copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
698 			     src->d_rt_spc_timer);
699 	dst->d_rtbwarns = src->d_rt_spc_warns;
700 }
701 
702 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
703 			   void __user *addr)
704 {
705 	struct fs_disk_quota fdq;
706 	struct qc_dqblk qdq;
707 	struct kqid qid;
708 	int ret;
709 
710 	if (!sb->s_qcop->get_dqblk)
711 		return -ENOSYS;
712 	qid = make_kqid(current_user_ns(), type, id);
713 	if (!qid_has_mapping(sb->s_user_ns, qid))
714 		return -EINVAL;
715 	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
716 	if (ret)
717 		return ret;
718 	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
719 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
720 		return -EFAULT;
721 	return ret;
722 }
723 
724 /*
725  * Return quota for next active quota >= this id, if any exists,
726  * otherwise return -ENOENT via ->get_nextdqblk.
727  */
728 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
729 			    void __user *addr)
730 {
731 	struct fs_disk_quota fdq;
732 	struct qc_dqblk qdq;
733 	struct kqid qid;
734 	qid_t id_out;
735 	int ret;
736 
737 	if (!sb->s_qcop->get_nextdqblk)
738 		return -ENOSYS;
739 	qid = make_kqid(current_user_ns(), type, id);
740 	if (!qid_has_mapping(sb->s_user_ns, qid))
741 		return -EINVAL;
742 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
743 	if (ret)
744 		return ret;
745 	id_out = from_kqid(current_user_ns(), qid);
746 	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
747 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
748 		return -EFAULT;
749 	return ret;
750 }
751 
752 static int quota_rmxquota(struct super_block *sb, void __user *addr)
753 {
754 	__u32 flags;
755 
756 	if (copy_from_user(&flags, addr, sizeof(flags)))
757 		return -EFAULT;
758 	if (!sb->s_qcop->rm_xquota)
759 		return -ENOSYS;
760 	return sb->s_qcop->rm_xquota(sb, flags);
761 }
762 
763 /* Copy parameters and call proper function */
764 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
765 		       void __user *addr, const struct path *path)
766 {
767 	int ret;
768 
769 	type = array_index_nospec(type, MAXQUOTAS);
770 	/*
771 	 * Quota not supported on this fs? Check this before s_quota_types
772 	 * since they needn't be set if quota is not supported at all.
773 	 */
774 	if (!sb->s_qcop)
775 		return -ENOSYS;
776 	if (!(sb->s_quota_types & (1 << type)))
777 		return -EINVAL;
778 
779 	ret = check_quotactl_permission(sb, type, cmd, id);
780 	if (ret < 0)
781 		return ret;
782 
783 	switch (cmd) {
784 	case Q_QUOTAON:
785 		return quota_quotaon(sb, type, id, path);
786 	case Q_QUOTAOFF:
787 		return quota_quotaoff(sb, type);
788 	case Q_GETFMT:
789 		return quota_getfmt(sb, type, addr);
790 	case Q_GETINFO:
791 		return quota_getinfo(sb, type, addr);
792 	case Q_SETINFO:
793 		return quota_setinfo(sb, type, addr);
794 	case Q_GETQUOTA:
795 		return quota_getquota(sb, type, id, addr);
796 	case Q_GETNEXTQUOTA:
797 		return quota_getnextquota(sb, type, id, addr);
798 	case Q_SETQUOTA:
799 		return quota_setquota(sb, type, id, addr);
800 	case Q_SYNC:
801 		if (!sb->s_qcop->quota_sync)
802 			return -ENOSYS;
803 		return sb->s_qcop->quota_sync(sb, type);
804 	case Q_XQUOTAON:
805 		return quota_enable(sb, addr);
806 	case Q_XQUOTAOFF:
807 		return quota_disable(sb, addr);
808 	case Q_XQUOTARM:
809 		return quota_rmxquota(sb, addr);
810 	case Q_XGETQSTAT:
811 		return quota_getxstate(sb, type, addr);
812 	case Q_XGETQSTATV:
813 		return quota_getxstatev(sb, type, addr);
814 	case Q_XSETQLIM:
815 		return quota_setxquota(sb, type, id, addr);
816 	case Q_XGETQUOTA:
817 		return quota_getxquota(sb, type, id, addr);
818 	case Q_XGETNEXTQUOTA:
819 		return quota_getnextxquota(sb, type, id, addr);
820 	case Q_XQUOTASYNC:
821 		if (sb_rdonly(sb))
822 			return -EROFS;
823 		/* XFS quotas are fully coherent now, making this call a noop */
824 		return 0;
825 	default:
826 		return -EINVAL;
827 	}
828 }
829 
830 #ifdef CONFIG_BLOCK
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 #endif /* CONFIG_BLOCK */
854 
855 /* Return true if quotactl command is manipulating quota on/off state */
856 static bool quotactl_cmd_onoff(int cmd)
857 {
858 	return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
859 		 (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
860 }
861 
862 /*
863  * look up a superblock on which quota ops will be performed
864  * - use the name of a block device to find the superblock thereon
865  */
866 static struct super_block *quotactl_block(const char __user *special, int cmd)
867 {
868 #ifdef CONFIG_BLOCK
869 	struct super_block *sb;
870 	struct filename *tmp = getname(special);
871 	bool excl = false, thawed = false;
872 	int error;
873 	dev_t dev;
874 
875 	if (IS_ERR(tmp))
876 		return ERR_CAST(tmp);
877 	error = lookup_bdev(tmp->name, &dev);
878 	putname(tmp);
879 	if (error)
880 		return ERR_PTR(error);
881 
882 	if (quotactl_cmd_onoff(cmd)) {
883 		excl = true;
884 		thawed = true;
885 	} else if (quotactl_cmd_write(cmd)) {
886 		thawed = true;
887 	}
888 
889 retry:
890 	sb = user_get_super(dev, excl);
891 	if (!sb)
892 		return ERR_PTR(-ENODEV);
893 	if (thawed && sb->s_writers.frozen != SB_UNFROZEN) {
894 		if (excl)
895 			up_write(&sb->s_umount);
896 		else
897 			up_read(&sb->s_umount);
898 		wait_event(sb->s_writers.wait_unfrozen,
899 			   sb->s_writers.frozen == SB_UNFROZEN);
900 		put_super(sb);
901 		goto retry;
902 	}
903 	return sb;
904 
905 #else
906 	return ERR_PTR(-ENODEV);
907 #endif
908 }
909 
910 /*
911  * This is the system call interface. This communicates with
912  * the user-level programs. Currently this only supports diskquota
913  * calls. Maybe we need to add the process quotas etc. in the future,
914  * but we probably should use rlimits for that.
915  */
916 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
917 		qid_t, id, void __user *, addr)
918 {
919 	uint cmds, type;
920 	struct super_block *sb = NULL;
921 	struct path path, *pathp = NULL;
922 	int ret;
923 
924 	cmds = cmd >> SUBCMDSHIFT;
925 	type = cmd & SUBCMDMASK;
926 
927 	if (type >= MAXQUOTAS)
928 		return -EINVAL;
929 
930 	/*
931 	 * As a special case Q_SYNC can be called without a specific device.
932 	 * It will iterate all superblocks that have quota enabled and call
933 	 * the sync action on each of them.
934 	 */
935 	if (!special) {
936 		if (cmds == Q_SYNC)
937 			return quota_sync_all(type);
938 		return -ENODEV;
939 	}
940 
941 	/*
942 	 * Path for quotaon has to be resolved before grabbing superblock
943 	 * because that gets s_umount sem which is also possibly needed by path
944 	 * resolution (think about autofs) and thus deadlocks could arise.
945 	 */
946 	if (cmds == Q_QUOTAON) {
947 		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
948 		if (ret)
949 			pathp = ERR_PTR(ret);
950 		else
951 			pathp = &path;
952 	}
953 
954 	sb = quotactl_block(special, cmds);
955 	if (IS_ERR(sb)) {
956 		ret = PTR_ERR(sb);
957 		goto out;
958 	}
959 
960 	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
961 
962 	if (!quotactl_cmd_onoff(cmds))
963 		drop_super(sb);
964 	else
965 		drop_super_exclusive(sb);
966 out:
967 	if (pathp && !IS_ERR(pathp))
968 		path_put(pathp);
969 	return ret;
970 }
971