xref: /linux/fs/quota/quota.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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/blkdev.h>
14 #include <linux/uaccess.h>
15 #include <linux/kernel.h>
16 #include <linux/security.h>
17 #include <linux/syscalls.h>
18 #include <linux/capability.h>
19 #include <linux/quotaops.h>
20 #include <linux/types.h>
21 #include <linux/mount.h>
22 #include <linux/writeback.h>
23 #include <linux/nospec.h>
24 #include "compat.h"
25 #include "../internal.h"
26 
27 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
28 				     qid_t id)
29 {
30 	switch (cmd) {
31 	/* these commands do not require any special privilegues */
32 	case Q_GETFMT:
33 	case Q_SYNC:
34 	case Q_GETINFO:
35 	case Q_XGETQSTAT:
36 	case Q_XGETQSTATV:
37 	case Q_XQUOTASYNC:
38 		break;
39 	/* allow to query information for dquots we "own" */
40 	case Q_GETQUOTA:
41 	case Q_XGETQUOTA:
42 		if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
43 		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
44 			break;
45 		fallthrough;
46 	default:
47 		if (!capable(CAP_SYS_ADMIN))
48 			return -EPERM;
49 	}
50 
51 	return security_quotactl(cmd, type, id, sb);
52 }
53 
54 static void quota_sync_one(struct super_block *sb, void *arg)
55 {
56 	int type = *(int *)arg;
57 
58 	if (sb->s_qcop && sb->s_qcop->quota_sync &&
59 	    (sb->s_quota_types & (1 << type)))
60 		sb->s_qcop->quota_sync(sb, type);
61 }
62 
63 static int quota_sync_all(int type)
64 {
65 	int ret;
66 
67 	ret = security_quotactl(Q_SYNC, type, 0, NULL);
68 	if (!ret)
69 		iterate_supers(quota_sync_one, &type);
70 	return ret;
71 }
72 
73 unsigned int qtype_enforce_flag(int type)
74 {
75 	switch (type) {
76 	case USRQUOTA:
77 		return FS_QUOTA_UDQ_ENFD;
78 	case GRPQUOTA:
79 		return FS_QUOTA_GDQ_ENFD;
80 	case PRJQUOTA:
81 		return FS_QUOTA_PDQ_ENFD;
82 	}
83 	return 0;
84 }
85 
86 static int quota_quotaon(struct super_block *sb, int type, qid_t id,
87 		         const struct path *path)
88 {
89 	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
90 		return -ENOSYS;
91 	if (sb->s_qcop->quota_enable)
92 		return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
93 	if (IS_ERR(path))
94 		return PTR_ERR(path);
95 	return sb->s_qcop->quota_on(sb, type, id, path);
96 }
97 
98 static int quota_quotaoff(struct super_block *sb, int type)
99 {
100 	if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
101 		return -ENOSYS;
102 	if (sb->s_qcop->quota_disable)
103 		return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
104 	return sb->s_qcop->quota_off(sb, type);
105 }
106 
107 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
108 {
109 	__u32 fmt;
110 
111 	if (!sb_has_quota_active(sb, type))
112 		return -ESRCH;
113 	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
114 	if (copy_to_user(addr, &fmt, sizeof(fmt)))
115 		return -EFAULT;
116 	return 0;
117 }
118 
119 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
120 {
121 	struct qc_state state;
122 	struct qc_type_state *tstate;
123 	struct if_dqinfo uinfo;
124 	int ret;
125 
126 	if (!sb->s_qcop->get_state)
127 		return -ENOSYS;
128 	ret = sb->s_qcop->get_state(sb, &state);
129 	if (ret)
130 		return ret;
131 	tstate = state.s_state + type;
132 	if (!(tstate->flags & QCI_ACCT_ENABLED))
133 		return -ESRCH;
134 	memset(&uinfo, 0, sizeof(uinfo));
135 	uinfo.dqi_bgrace = tstate->spc_timelimit;
136 	uinfo.dqi_igrace = tstate->ino_timelimit;
137 	if (tstate->flags & QCI_SYSFILE)
138 		uinfo.dqi_flags |= DQF_SYS_FILE;
139 	if (tstate->flags & QCI_ROOT_SQUASH)
140 		uinfo.dqi_flags |= DQF_ROOT_SQUASH;
141 	uinfo.dqi_valid = IIF_ALL;
142 	if (copy_to_user(addr, &uinfo, sizeof(uinfo)))
143 		return -EFAULT;
144 	return 0;
145 }
146 
147 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
148 {
149 	struct if_dqinfo info;
150 	struct qc_info qinfo;
151 
152 	if (copy_from_user(&info, addr, sizeof(info)))
153 		return -EFAULT;
154 	if (!sb->s_qcop->set_info)
155 		return -ENOSYS;
156 	if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
157 		return -EINVAL;
158 	memset(&qinfo, 0, sizeof(qinfo));
159 	if (info.dqi_valid & IIF_FLAGS) {
160 		if (info.dqi_flags & ~DQF_SETINFO_MASK)
161 			return -EINVAL;
162 		if (info.dqi_flags & DQF_ROOT_SQUASH)
163 			qinfo.i_flags |= QCI_ROOT_SQUASH;
164 		qinfo.i_fieldmask |= QC_FLAGS;
165 	}
166 	if (info.dqi_valid & IIF_BGRACE) {
167 		qinfo.i_spc_timelimit = info.dqi_bgrace;
168 		qinfo.i_fieldmask |= QC_SPC_TIMER;
169 	}
170 	if (info.dqi_valid & IIF_IGRACE) {
171 		qinfo.i_ino_timelimit = info.dqi_igrace;
172 		qinfo.i_fieldmask |= QC_INO_TIMER;
173 	}
174 	return sb->s_qcop->set_info(sb, type, &qinfo);
175 }
176 
177 static inline qsize_t qbtos(qsize_t blocks)
178 {
179 	return blocks << QIF_DQBLKSIZE_BITS;
180 }
181 
182 static inline qsize_t stoqb(qsize_t space)
183 {
184 	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
185 }
186 
187 static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
188 {
189 	memset(dst, 0, sizeof(*dst));
190 	dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
191 	dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
192 	dst->dqb_curspace = src->d_space;
193 	dst->dqb_ihardlimit = src->d_ino_hardlimit;
194 	dst->dqb_isoftlimit = src->d_ino_softlimit;
195 	dst->dqb_curinodes = src->d_ino_count;
196 	dst->dqb_btime = src->d_spc_timer;
197 	dst->dqb_itime = src->d_ino_timer;
198 	dst->dqb_valid = QIF_ALL;
199 }
200 
201 static int quota_getquota(struct super_block *sb, int type, qid_t id,
202 			  void __user *addr)
203 {
204 	struct kqid qid;
205 	struct qc_dqblk fdq;
206 	struct if_dqblk idq;
207 	int ret;
208 
209 	if (!sb->s_qcop->get_dqblk)
210 		return -ENOSYS;
211 	qid = make_kqid(current_user_ns(), type, id);
212 	if (!qid_has_mapping(sb->s_user_ns, qid))
213 		return -EINVAL;
214 	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
215 	if (ret)
216 		return ret;
217 	copy_to_if_dqblk(&idq, &fdq);
218 
219 	if (compat_need_64bit_alignment_fixup()) {
220 		struct compat_if_dqblk __user *compat_dqblk = addr;
221 
222 		if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
223 			return -EFAULT;
224 		if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
225 			return -EFAULT;
226 	} else {
227 		if (copy_to_user(addr, &idq, sizeof(idq)))
228 			return -EFAULT;
229 	}
230 	return 0;
231 }
232 
233 /*
234  * Return quota for next active quota >= this id, if any exists,
235  * otherwise return -ENOENT via ->get_nextdqblk
236  */
237 static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
238 			  void __user *addr)
239 {
240 	struct kqid qid;
241 	struct qc_dqblk fdq;
242 	struct if_nextdqblk idq;
243 	int ret;
244 
245 	if (!sb->s_qcop->get_nextdqblk)
246 		return -ENOSYS;
247 	qid = make_kqid(current_user_ns(), type, id);
248 	if (!qid_has_mapping(sb->s_user_ns, qid))
249 		return -EINVAL;
250 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
251 	if (ret)
252 		return ret;
253 	/* struct if_nextdqblk is a superset of struct if_dqblk */
254 	copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
255 	idq.dqb_id = from_kqid(current_user_ns(), qid);
256 	if (copy_to_user(addr, &idq, sizeof(idq)))
257 		return -EFAULT;
258 	return 0;
259 }
260 
261 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
262 {
263 	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
264 	dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
265 	dst->d_space = src->dqb_curspace;
266 	dst->d_ino_hardlimit = src->dqb_ihardlimit;
267 	dst->d_ino_softlimit = src->dqb_isoftlimit;
268 	dst->d_ino_count = src->dqb_curinodes;
269 	dst->d_spc_timer = src->dqb_btime;
270 	dst->d_ino_timer = src->dqb_itime;
271 
272 	dst->d_fieldmask = 0;
273 	if (src->dqb_valid & QIF_BLIMITS)
274 		dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
275 	if (src->dqb_valid & QIF_SPACE)
276 		dst->d_fieldmask |= QC_SPACE;
277 	if (src->dqb_valid & QIF_ILIMITS)
278 		dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
279 	if (src->dqb_valid & QIF_INODES)
280 		dst->d_fieldmask |= QC_INO_COUNT;
281 	if (src->dqb_valid & QIF_BTIME)
282 		dst->d_fieldmask |= QC_SPC_TIMER;
283 	if (src->dqb_valid & QIF_ITIME)
284 		dst->d_fieldmask |= QC_INO_TIMER;
285 }
286 
287 static int quota_setquota(struct super_block *sb, int type, qid_t id,
288 			  void __user *addr)
289 {
290 	struct qc_dqblk fdq;
291 	struct if_dqblk idq;
292 	struct kqid qid;
293 
294 	if (compat_need_64bit_alignment_fixup()) {
295 		struct compat_if_dqblk __user *compat_dqblk = addr;
296 
297 		if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
298 		    get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
299 			return -EFAULT;
300 	} else {
301 		if (copy_from_user(&idq, addr, sizeof(idq)))
302 			return -EFAULT;
303 	}
304 	if (!sb->s_qcop->set_dqblk)
305 		return -ENOSYS;
306 	qid = make_kqid(current_user_ns(), type, id);
307 	if (!qid_has_mapping(sb->s_user_ns, qid))
308 		return -EINVAL;
309 	copy_from_if_dqblk(&fdq, &idq);
310 	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
311 }
312 
313 static int quota_enable(struct super_block *sb, void __user *addr)
314 {
315 	__u32 flags;
316 
317 	if (copy_from_user(&flags, addr, sizeof(flags)))
318 		return -EFAULT;
319 	if (!sb->s_qcop->quota_enable)
320 		return -ENOSYS;
321 	return sb->s_qcop->quota_enable(sb, flags);
322 }
323 
324 static int quota_disable(struct super_block *sb, void __user *addr)
325 {
326 	__u32 flags;
327 
328 	if (copy_from_user(&flags, addr, sizeof(flags)))
329 		return -EFAULT;
330 	if (!sb->s_qcop->quota_disable)
331 		return -ENOSYS;
332 	return sb->s_qcop->quota_disable(sb, flags);
333 }
334 
335 static int quota_state_to_flags(struct qc_state *state)
336 {
337 	int flags = 0;
338 
339 	if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
340 		flags |= FS_QUOTA_UDQ_ACCT;
341 	if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
342 		flags |= FS_QUOTA_UDQ_ENFD;
343 	if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
344 		flags |= FS_QUOTA_GDQ_ACCT;
345 	if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
346 		flags |= FS_QUOTA_GDQ_ENFD;
347 	if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
348 		flags |= FS_QUOTA_PDQ_ACCT;
349 	if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
350 		flags |= FS_QUOTA_PDQ_ENFD;
351 	return flags;
352 }
353 
354 static int quota_getstate(struct super_block *sb, int type,
355 			  struct fs_quota_stat *fqs)
356 {
357 	struct qc_state state;
358 	int ret;
359 
360 	memset(&state, 0, sizeof (struct qc_state));
361 	ret = sb->s_qcop->get_state(sb, &state);
362 	if (ret < 0)
363 		return ret;
364 
365 	memset(fqs, 0, sizeof(*fqs));
366 	fqs->qs_version = FS_QSTAT_VERSION;
367 	fqs->qs_flags = quota_state_to_flags(&state);
368 	/* No quota enabled? */
369 	if (!fqs->qs_flags)
370 		return -ENOSYS;
371 	fqs->qs_incoredqs = state.s_incoredqs;
372 
373 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
374 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
375 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
376 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
377 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
378 
379 	/* Inodes may be allocated even if inactive; copy out if present */
380 	if (state.s_state[USRQUOTA].ino) {
381 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
382 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
383 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
384 	}
385 	if (state.s_state[GRPQUOTA].ino) {
386 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
387 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
388 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
389 	}
390 	if (state.s_state[PRJQUOTA].ino) {
391 		/*
392 		 * Q_XGETQSTAT doesn't have room for both group and project
393 		 * quotas.  So, allow the project quota values to be copied out
394 		 * only if there is no group quota information available.
395 		 */
396 		if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
397 			fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
398 			fqs->qs_gquota.qfs_nblks =
399 					state.s_state[PRJQUOTA].blocks;
400 			fqs->qs_gquota.qfs_nextents =
401 					state.s_state[PRJQUOTA].nextents;
402 		}
403 	}
404 	return 0;
405 }
406 
407 static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
408 		struct fs_qfilestat *from)
409 {
410 	if (copy_to_user(to, from, sizeof(*to)) ||
411 	    put_user(from->qfs_nextents, &to->qfs_nextents))
412 		return -EFAULT;
413 	return 0;
414 }
415 
416 static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
417 		struct fs_quota_stat *from)
418 {
419 	if (put_user(from->qs_version, &to->qs_version) ||
420 	    put_user(from->qs_flags, &to->qs_flags) ||
421 	    put_user(from->qs_pad, &to->qs_pad) ||
422 	    compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
423 	    compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
424 	    put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
425 	    put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
426 	    put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
427 	    put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
428 	    put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
429 	    put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
430 		return -EFAULT;
431 	return 0;
432 }
433 
434 static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
435 {
436 	struct fs_quota_stat fqs;
437 	int ret;
438 
439 	if (!sb->s_qcop->get_state)
440 		return -ENOSYS;
441 	ret = quota_getstate(sb, type, &fqs);
442 	if (ret)
443 		return ret;
444 
445 	if (compat_need_64bit_alignment_fixup())
446 		return compat_copy_fs_quota_stat(addr, &fqs);
447 	if (copy_to_user(addr, &fqs, sizeof(fqs)))
448 		return -EFAULT;
449 	return 0;
450 }
451 
452 static int quota_getstatev(struct super_block *sb, int type,
453 			   struct fs_quota_statv *fqs)
454 {
455 	struct qc_state state;
456 	int ret;
457 
458 	memset(&state, 0, sizeof (struct qc_state));
459 	ret = sb->s_qcop->get_state(sb, &state);
460 	if (ret < 0)
461 		return ret;
462 
463 	memset(fqs, 0, sizeof(*fqs));
464 	fqs->qs_version = FS_QSTAT_VERSION;
465 	fqs->qs_flags = quota_state_to_flags(&state);
466 	/* No quota enabled? */
467 	if (!fqs->qs_flags)
468 		return -ENOSYS;
469 	fqs->qs_incoredqs = state.s_incoredqs;
470 
471 	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
472 	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
473 	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
474 	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
475 	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
476 	fqs->qs_rtbwarnlimit = state.s_state[type].rt_spc_warnlimit;
477 
478 	/* Inodes may be allocated even if inactive; copy out if present */
479 	if (state.s_state[USRQUOTA].ino) {
480 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
481 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
482 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
483 	}
484 	if (state.s_state[GRPQUOTA].ino) {
485 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
486 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
487 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
488 	}
489 	if (state.s_state[PRJQUOTA].ino) {
490 		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
491 		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
492 		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
493 	}
494 	return 0;
495 }
496 
497 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
498 {
499 	struct fs_quota_statv fqs;
500 	int ret;
501 
502 	if (!sb->s_qcop->get_state)
503 		return -ENOSYS;
504 
505 	memset(&fqs, 0, sizeof(fqs));
506 	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
507 		return -EFAULT;
508 
509 	/* If this kernel doesn't support user specified version, fail */
510 	switch (fqs.qs_version) {
511 	case FS_QSTATV_VERSION1:
512 		break;
513 	default:
514 		return -EINVAL;
515 	}
516 	ret = quota_getstatev(sb, type, &fqs);
517 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
518 		return -EFAULT;
519 	return ret;
520 }
521 
522 /*
523  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
524  * out of there as xfsprogs rely on definitions being in that header file. So
525  * just define same functions here for quota purposes.
526  */
527 #define XFS_BB_SHIFT 9
528 
529 static inline u64 quota_bbtob(u64 blocks)
530 {
531 	return blocks << XFS_BB_SHIFT;
532 }
533 
534 static inline u64 quota_btobb(u64 bytes)
535 {
536 	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
537 }
538 
539 static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
540 		__s32 timer, __s8 timer_hi)
541 {
542 	if (d->d_fieldmask & FS_DQ_BIGTIME)
543 		return (u32)timer | (s64)timer_hi << 32;
544 	return timer;
545 }
546 
547 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
548 {
549 	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
550 	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
551 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
552 	dst->d_ino_softlimit = src->d_ino_softlimit;
553 	dst->d_space = quota_bbtob(src->d_bcount);
554 	dst->d_ino_count = src->d_icount;
555 	dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
556 						  src->d_itimer_hi);
557 	dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
558 						  src->d_btimer_hi);
559 	dst->d_ino_warns = src->d_iwarns;
560 	dst->d_spc_warns = src->d_bwarns;
561 	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
562 	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
563 	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
564 	dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
565 						     src->d_rtbtimer_hi);
566 	dst->d_rt_spc_warns = src->d_rtbwarns;
567 	dst->d_fieldmask = 0;
568 	if (src->d_fieldmask & FS_DQ_ISOFT)
569 		dst->d_fieldmask |= QC_INO_SOFT;
570 	if (src->d_fieldmask & FS_DQ_IHARD)
571 		dst->d_fieldmask |= QC_INO_HARD;
572 	if (src->d_fieldmask & FS_DQ_BSOFT)
573 		dst->d_fieldmask |= QC_SPC_SOFT;
574 	if (src->d_fieldmask & FS_DQ_BHARD)
575 		dst->d_fieldmask |= QC_SPC_HARD;
576 	if (src->d_fieldmask & FS_DQ_RTBSOFT)
577 		dst->d_fieldmask |= QC_RT_SPC_SOFT;
578 	if (src->d_fieldmask & FS_DQ_RTBHARD)
579 		dst->d_fieldmask |= QC_RT_SPC_HARD;
580 	if (src->d_fieldmask & FS_DQ_BTIMER)
581 		dst->d_fieldmask |= QC_SPC_TIMER;
582 	if (src->d_fieldmask & FS_DQ_ITIMER)
583 		dst->d_fieldmask |= QC_INO_TIMER;
584 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
585 		dst->d_fieldmask |= QC_RT_SPC_TIMER;
586 	if (src->d_fieldmask & FS_DQ_BWARNS)
587 		dst->d_fieldmask |= QC_SPC_WARNS;
588 	if (src->d_fieldmask & FS_DQ_IWARNS)
589 		dst->d_fieldmask |= QC_INO_WARNS;
590 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
591 		dst->d_fieldmask |= QC_RT_SPC_WARNS;
592 	if (src->d_fieldmask & FS_DQ_BCOUNT)
593 		dst->d_fieldmask |= QC_SPACE;
594 	if (src->d_fieldmask & FS_DQ_ICOUNT)
595 		dst->d_fieldmask |= QC_INO_COUNT;
596 	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
597 		dst->d_fieldmask |= QC_RT_SPACE;
598 }
599 
600 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
601 				       struct fs_disk_quota *src)
602 {
603 	memset(dst, 0, sizeof(*dst));
604 	dst->i_spc_timelimit = src->d_btimer;
605 	dst->i_ino_timelimit = src->d_itimer;
606 	dst->i_rt_spc_timelimit = src->d_rtbtimer;
607 	dst->i_ino_warnlimit = src->d_iwarns;
608 	dst->i_spc_warnlimit = src->d_bwarns;
609 	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
610 	if (src->d_fieldmask & FS_DQ_BWARNS)
611 		dst->i_fieldmask |= QC_SPC_WARNS;
612 	if (src->d_fieldmask & FS_DQ_IWARNS)
613 		dst->i_fieldmask |= QC_INO_WARNS;
614 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
615 		dst->i_fieldmask |= QC_RT_SPC_WARNS;
616 	if (src->d_fieldmask & FS_DQ_BTIMER)
617 		dst->i_fieldmask |= QC_SPC_TIMER;
618 	if (src->d_fieldmask & FS_DQ_ITIMER)
619 		dst->i_fieldmask |= QC_INO_TIMER;
620 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
621 		dst->i_fieldmask |= QC_RT_SPC_TIMER;
622 }
623 
624 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
625 			   void __user *addr)
626 {
627 	struct fs_disk_quota fdq;
628 	struct qc_dqblk qdq;
629 	struct kqid qid;
630 
631 	if (copy_from_user(&fdq, addr, sizeof(fdq)))
632 		return -EFAULT;
633 	if (!sb->s_qcop->set_dqblk)
634 		return -ENOSYS;
635 	qid = make_kqid(current_user_ns(), type, id);
636 	if (!qid_has_mapping(sb->s_user_ns, qid))
637 		return -EINVAL;
638 	/* Are we actually setting timer / warning limits for all users? */
639 	if (from_kqid(sb->s_user_ns, qid) == 0 &&
640 	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
641 		struct qc_info qinfo;
642 		int ret;
643 
644 		if (!sb->s_qcop->set_info)
645 			return -EINVAL;
646 		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
647 		ret = sb->s_qcop->set_info(sb, type, &qinfo);
648 		if (ret)
649 			return ret;
650 		/* These are already done */
651 		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
652 	}
653 	copy_from_xfs_dqblk(&qdq, &fdq);
654 	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
655 }
656 
657 static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
658 		__s32 *timer_lo, __s8 *timer_hi, s64 timer)
659 {
660 	*timer_lo = timer;
661 	if (d->d_fieldmask & FS_DQ_BIGTIME)
662 		*timer_hi = timer >> 32;
663 }
664 
665 static inline bool want_bigtime(s64 timer)
666 {
667 	return timer > S32_MAX || timer < S32_MIN;
668 }
669 
670 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
671 			      int type, qid_t id)
672 {
673 	memset(dst, 0, sizeof(*dst));
674 	if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
675 	    want_bigtime(src->d_rt_spc_timer))
676 		dst->d_fieldmask |= FS_DQ_BIGTIME;
677 	dst->d_version = FS_DQUOT_VERSION;
678 	dst->d_id = id;
679 	if (type == USRQUOTA)
680 		dst->d_flags = FS_USER_QUOTA;
681 	else if (type == PRJQUOTA)
682 		dst->d_flags = FS_PROJ_QUOTA;
683 	else
684 		dst->d_flags = FS_GROUP_QUOTA;
685 	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
686 	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
687 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
688 	dst->d_ino_softlimit = src->d_ino_softlimit;
689 	dst->d_bcount = quota_btobb(src->d_space);
690 	dst->d_icount = src->d_ino_count;
691 	copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
692 			     src->d_ino_timer);
693 	copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
694 			     src->d_spc_timer);
695 	dst->d_iwarns = src->d_ino_warns;
696 	dst->d_bwarns = src->d_spc_warns;
697 	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
698 	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
699 	dst->d_rtbcount = quota_btobb(src->d_rt_space);
700 	copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
701 			     src->d_rt_spc_timer);
702 	dst->d_rtbwarns = src->d_rt_spc_warns;
703 }
704 
705 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
706 			   void __user *addr)
707 {
708 	struct fs_disk_quota fdq;
709 	struct qc_dqblk qdq;
710 	struct kqid qid;
711 	int ret;
712 
713 	if (!sb->s_qcop->get_dqblk)
714 		return -ENOSYS;
715 	qid = make_kqid(current_user_ns(), type, id);
716 	if (!qid_has_mapping(sb->s_user_ns, qid))
717 		return -EINVAL;
718 	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
719 	if (ret)
720 		return ret;
721 	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
722 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
723 		return -EFAULT;
724 	return ret;
725 }
726 
727 /*
728  * Return quota for next active quota >= this id, if any exists,
729  * otherwise return -ENOENT via ->get_nextdqblk.
730  */
731 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
732 			    void __user *addr)
733 {
734 	struct fs_disk_quota fdq;
735 	struct qc_dqblk qdq;
736 	struct kqid qid;
737 	qid_t id_out;
738 	int ret;
739 
740 	if (!sb->s_qcop->get_nextdqblk)
741 		return -ENOSYS;
742 	qid = make_kqid(current_user_ns(), type, id);
743 	if (!qid_has_mapping(sb->s_user_ns, qid))
744 		return -EINVAL;
745 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
746 	if (ret)
747 		return ret;
748 	id_out = from_kqid(current_user_ns(), qid);
749 	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
750 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
751 		return -EFAULT;
752 	return ret;
753 }
754 
755 static int quota_rmxquota(struct super_block *sb, void __user *addr)
756 {
757 	__u32 flags;
758 
759 	if (copy_from_user(&flags, addr, sizeof(flags)))
760 		return -EFAULT;
761 	if (!sb->s_qcop->rm_xquota)
762 		return -ENOSYS;
763 	return sb->s_qcop->rm_xquota(sb, flags);
764 }
765 
766 /* Copy parameters and call proper function */
767 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
768 		       void __user *addr, const struct path *path)
769 {
770 	int ret;
771 
772 	type = array_index_nospec(type, MAXQUOTAS);
773 	/*
774 	 * Quota not supported on this fs? Check this before s_quota_types
775 	 * since they needn't be set if quota is not supported at all.
776 	 */
777 	if (!sb->s_qcop)
778 		return -ENOSYS;
779 	if (!(sb->s_quota_types & (1 << type)))
780 		return -EINVAL;
781 
782 	ret = check_quotactl_permission(sb, type, cmd, id);
783 	if (ret < 0)
784 		return ret;
785 
786 	switch (cmd) {
787 	case Q_QUOTAON:
788 		return quota_quotaon(sb, type, id, path);
789 	case Q_QUOTAOFF:
790 		return quota_quotaoff(sb, type);
791 	case Q_GETFMT:
792 		return quota_getfmt(sb, type, addr);
793 	case Q_GETINFO:
794 		return quota_getinfo(sb, type, addr);
795 	case Q_SETINFO:
796 		return quota_setinfo(sb, type, addr);
797 	case Q_GETQUOTA:
798 		return quota_getquota(sb, type, id, addr);
799 	case Q_GETNEXTQUOTA:
800 		return quota_getnextquota(sb, type, id, addr);
801 	case Q_SETQUOTA:
802 		return quota_setquota(sb, type, id, addr);
803 	case Q_SYNC:
804 		if (!sb->s_qcop->quota_sync)
805 			return -ENOSYS;
806 		return sb->s_qcop->quota_sync(sb, type);
807 	case Q_XQUOTAON:
808 		return quota_enable(sb, addr);
809 	case Q_XQUOTAOFF:
810 		return quota_disable(sb, addr);
811 	case Q_XQUOTARM:
812 		return quota_rmxquota(sb, addr);
813 	case Q_XGETQSTAT:
814 		return quota_getxstate(sb, type, addr);
815 	case Q_XGETQSTATV:
816 		return quota_getxstatev(sb, type, addr);
817 	case Q_XSETQLIM:
818 		return quota_setxquota(sb, type, id, addr);
819 	case Q_XGETQUOTA:
820 		return quota_getxquota(sb, type, id, addr);
821 	case Q_XGETNEXTQUOTA:
822 		return quota_getnextxquota(sb, type, id, addr);
823 	case Q_XQUOTASYNC:
824 		if (sb_rdonly(sb))
825 			return -EROFS;
826 		/* XFS quotas are fully coherent now, making this call a noop */
827 		return 0;
828 	default:
829 		return -EINVAL;
830 	}
831 }
832 
833 /* Return 1 if 'cmd' will block on frozen filesystem */
834 static int quotactl_cmd_write(int cmd)
835 {
836 	/*
837 	 * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
838 	 * as dquot_acquire() may allocate space for new structure and OCFS2
839 	 * needs to increment on-disk use count.
840 	 */
841 	switch (cmd) {
842 	case Q_GETFMT:
843 	case Q_GETINFO:
844 	case Q_SYNC:
845 	case Q_XGETQSTAT:
846 	case Q_XGETQSTATV:
847 	case Q_XGETQUOTA:
848 	case Q_XGETNEXTQUOTA:
849 	case Q_XQUOTASYNC:
850 		return 0;
851 	}
852 	return 1;
853 }
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 for sb to unfreeze */
899 		sb_start_write(sb);
900 		sb_end_write(sb);
901 		put_super(sb);
902 		goto retry;
903 	}
904 	return sb;
905 
906 #else
907 	return ERR_PTR(-ENODEV);
908 #endif
909 }
910 
911 /*
912  * This is the system call interface. This communicates with
913  * the user-level programs. Currently this only supports diskquota
914  * calls. Maybe we need to add the process quotas etc. in the future,
915  * but we probably should use rlimits for that.
916  */
917 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
918 		qid_t, id, void __user *, addr)
919 {
920 	uint cmds, type;
921 	struct super_block *sb = NULL;
922 	struct path path, *pathp = NULL;
923 	int ret;
924 
925 	cmds = cmd >> SUBCMDSHIFT;
926 	type = cmd & SUBCMDMASK;
927 
928 	if (type >= MAXQUOTAS)
929 		return -EINVAL;
930 
931 	/*
932 	 * As a special case Q_SYNC can be called without a specific device.
933 	 * It will iterate all superblocks that have quota enabled and call
934 	 * the sync action on each of them.
935 	 */
936 	if (!special) {
937 		if (cmds == Q_SYNC)
938 			return quota_sync_all(type);
939 		return -ENODEV;
940 	}
941 
942 	/*
943 	 * Path for quotaon has to be resolved before grabbing superblock
944 	 * because that gets s_umount sem which is also possibly needed by path
945 	 * resolution (think about autofs) and thus deadlocks could arise.
946 	 */
947 	if (cmds == Q_QUOTAON) {
948 		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
949 		if (ret)
950 			pathp = ERR_PTR(ret);
951 		else
952 			pathp = &path;
953 	}
954 
955 	sb = quotactl_block(special, cmds);
956 	if (IS_ERR(sb)) {
957 		ret = PTR_ERR(sb);
958 		goto out;
959 	}
960 
961 	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
962 
963 	if (!quotactl_cmd_onoff(cmds))
964 		drop_super(sb);
965 	else
966 		drop_super_exclusive(sb);
967 out:
968 	if (pathp && !IS_ERR(pathp))
969 		path_put(pathp);
970 	return ret;
971 }
972 
973 SYSCALL_DEFINE4(quotactl_fd, unsigned int, fd, unsigned int, cmd,
974 		qid_t, id, void __user *, addr)
975 {
976 	struct super_block *sb;
977 	unsigned int cmds = cmd >> SUBCMDSHIFT;
978 	unsigned int type = cmd & SUBCMDMASK;
979 	struct fd f;
980 	int ret;
981 
982 	f = fdget_raw(fd);
983 	if (!fd_file(f))
984 		return -EBADF;
985 
986 	ret = -EINVAL;
987 	if (type >= MAXQUOTAS)
988 		goto out;
989 
990 	if (quotactl_cmd_write(cmds)) {
991 		ret = mnt_want_write(fd_file(f)->f_path.mnt);
992 		if (ret)
993 			goto out;
994 	}
995 
996 	sb = fd_file(f)->f_path.mnt->mnt_sb;
997 	if (quotactl_cmd_onoff(cmds))
998 		down_write(&sb->s_umount);
999 	else
1000 		down_read(&sb->s_umount);
1001 
1002 	ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
1003 
1004 	if (quotactl_cmd_onoff(cmds))
1005 		up_write(&sb->s_umount);
1006 	else
1007 		up_read(&sb->s_umount);
1008 
1009 	if (quotactl_cmd_write(cmds))
1010 		mnt_drop_write(fd_file(f)->f_path.mnt);
1011 out:
1012 	fdput(f);
1013 	return ret;
1014 }
1015