xref: /openbmc/linux/fs/quota/quota.c (revision 9dfa23c8)
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 
476 	/* Inodes may be allocated even if inactive; copy out if present */
477 	if (state.s_state[USRQUOTA].ino) {
478 		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
479 		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
480 		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
481 	}
482 	if (state.s_state[GRPQUOTA].ino) {
483 		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
484 		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
485 		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
486 	}
487 	if (state.s_state[PRJQUOTA].ino) {
488 		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
489 		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
490 		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
491 	}
492 	return 0;
493 }
494 
495 static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)
496 {
497 	struct fs_quota_statv fqs;
498 	int ret;
499 
500 	if (!sb->s_qcop->get_state)
501 		return -ENOSYS;
502 
503 	memset(&fqs, 0, sizeof(fqs));
504 	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
505 		return -EFAULT;
506 
507 	/* If this kernel doesn't support user specified version, fail */
508 	switch (fqs.qs_version) {
509 	case FS_QSTATV_VERSION1:
510 		break;
511 	default:
512 		return -EINVAL;
513 	}
514 	ret = quota_getstatev(sb, type, &fqs);
515 	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
516 		return -EFAULT;
517 	return ret;
518 }
519 
520 /*
521  * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
522  * out of there as xfsprogs rely on definitions being in that header file. So
523  * just define same functions here for quota purposes.
524  */
525 #define XFS_BB_SHIFT 9
526 
527 static inline u64 quota_bbtob(u64 blocks)
528 {
529 	return blocks << XFS_BB_SHIFT;
530 }
531 
532 static inline u64 quota_btobb(u64 bytes)
533 {
534 	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
535 }
536 
537 static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
538 		__s32 timer, __s8 timer_hi)
539 {
540 	if (d->d_fieldmask & FS_DQ_BIGTIME)
541 		return (u32)timer | (s64)timer_hi << 32;
542 	return timer;
543 }
544 
545 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
546 {
547 	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
548 	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
549 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
550 	dst->d_ino_softlimit = src->d_ino_softlimit;
551 	dst->d_space = quota_bbtob(src->d_bcount);
552 	dst->d_ino_count = src->d_icount;
553 	dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
554 						  src->d_itimer_hi);
555 	dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
556 						  src->d_btimer_hi);
557 	dst->d_ino_warns = src->d_iwarns;
558 	dst->d_spc_warns = src->d_bwarns;
559 	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
560 	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
561 	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
562 	dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
563 						     src->d_rtbtimer_hi);
564 	dst->d_rt_spc_warns = src->d_rtbwarns;
565 	dst->d_fieldmask = 0;
566 	if (src->d_fieldmask & FS_DQ_ISOFT)
567 		dst->d_fieldmask |= QC_INO_SOFT;
568 	if (src->d_fieldmask & FS_DQ_IHARD)
569 		dst->d_fieldmask |= QC_INO_HARD;
570 	if (src->d_fieldmask & FS_DQ_BSOFT)
571 		dst->d_fieldmask |= QC_SPC_SOFT;
572 	if (src->d_fieldmask & FS_DQ_BHARD)
573 		dst->d_fieldmask |= QC_SPC_HARD;
574 	if (src->d_fieldmask & FS_DQ_RTBSOFT)
575 		dst->d_fieldmask |= QC_RT_SPC_SOFT;
576 	if (src->d_fieldmask & FS_DQ_RTBHARD)
577 		dst->d_fieldmask |= QC_RT_SPC_HARD;
578 	if (src->d_fieldmask & FS_DQ_BTIMER)
579 		dst->d_fieldmask |= QC_SPC_TIMER;
580 	if (src->d_fieldmask & FS_DQ_ITIMER)
581 		dst->d_fieldmask |= QC_INO_TIMER;
582 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
583 		dst->d_fieldmask |= QC_RT_SPC_TIMER;
584 	if (src->d_fieldmask & FS_DQ_BWARNS)
585 		dst->d_fieldmask |= QC_SPC_WARNS;
586 	if (src->d_fieldmask & FS_DQ_IWARNS)
587 		dst->d_fieldmask |= QC_INO_WARNS;
588 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
589 		dst->d_fieldmask |= QC_RT_SPC_WARNS;
590 	if (src->d_fieldmask & FS_DQ_BCOUNT)
591 		dst->d_fieldmask |= QC_SPACE;
592 	if (src->d_fieldmask & FS_DQ_ICOUNT)
593 		dst->d_fieldmask |= QC_INO_COUNT;
594 	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
595 		dst->d_fieldmask |= QC_RT_SPACE;
596 }
597 
598 static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
599 				       struct fs_disk_quota *src)
600 {
601 	memset(dst, 0, sizeof(*dst));
602 	dst->i_spc_timelimit = src->d_btimer;
603 	dst->i_ino_timelimit = src->d_itimer;
604 	dst->i_rt_spc_timelimit = src->d_rtbtimer;
605 	dst->i_ino_warnlimit = src->d_iwarns;
606 	dst->i_spc_warnlimit = src->d_bwarns;
607 	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
608 	if (src->d_fieldmask & FS_DQ_BWARNS)
609 		dst->i_fieldmask |= QC_SPC_WARNS;
610 	if (src->d_fieldmask & FS_DQ_IWARNS)
611 		dst->i_fieldmask |= QC_INO_WARNS;
612 	if (src->d_fieldmask & FS_DQ_RTBWARNS)
613 		dst->i_fieldmask |= QC_RT_SPC_WARNS;
614 	if (src->d_fieldmask & FS_DQ_BTIMER)
615 		dst->i_fieldmask |= QC_SPC_TIMER;
616 	if (src->d_fieldmask & FS_DQ_ITIMER)
617 		dst->i_fieldmask |= QC_INO_TIMER;
618 	if (src->d_fieldmask & FS_DQ_RTBTIMER)
619 		dst->i_fieldmask |= QC_RT_SPC_TIMER;
620 }
621 
622 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
623 			   void __user *addr)
624 {
625 	struct fs_disk_quota fdq;
626 	struct qc_dqblk qdq;
627 	struct kqid qid;
628 
629 	if (copy_from_user(&fdq, addr, sizeof(fdq)))
630 		return -EFAULT;
631 	if (!sb->s_qcop->set_dqblk)
632 		return -ENOSYS;
633 	qid = make_kqid(current_user_ns(), type, id);
634 	if (!qid_has_mapping(sb->s_user_ns, qid))
635 		return -EINVAL;
636 	/* Are we actually setting timer / warning limits for all users? */
637 	if (from_kqid(sb->s_user_ns, qid) == 0 &&
638 	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
639 		struct qc_info qinfo;
640 		int ret;
641 
642 		if (!sb->s_qcop->set_info)
643 			return -EINVAL;
644 		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
645 		ret = sb->s_qcop->set_info(sb, type, &qinfo);
646 		if (ret)
647 			return ret;
648 		/* These are already done */
649 		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
650 	}
651 	copy_from_xfs_dqblk(&qdq, &fdq);
652 	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
653 }
654 
655 static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
656 		__s32 *timer_lo, __s8 *timer_hi, s64 timer)
657 {
658 	*timer_lo = timer;
659 	if (d->d_fieldmask & FS_DQ_BIGTIME)
660 		*timer_hi = timer >> 32;
661 }
662 
663 static inline bool want_bigtime(s64 timer)
664 {
665 	return timer > S32_MAX || timer < S32_MIN;
666 }
667 
668 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
669 			      int type, qid_t id)
670 {
671 	memset(dst, 0, sizeof(*dst));
672 	if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
673 	    want_bigtime(src->d_rt_spc_timer))
674 		dst->d_fieldmask |= FS_DQ_BIGTIME;
675 	dst->d_version = FS_DQUOT_VERSION;
676 	dst->d_id = id;
677 	if (type == USRQUOTA)
678 		dst->d_flags = FS_USER_QUOTA;
679 	else if (type == PRJQUOTA)
680 		dst->d_flags = FS_PROJ_QUOTA;
681 	else
682 		dst->d_flags = FS_GROUP_QUOTA;
683 	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
684 	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
685 	dst->d_ino_hardlimit = src->d_ino_hardlimit;
686 	dst->d_ino_softlimit = src->d_ino_softlimit;
687 	dst->d_bcount = quota_btobb(src->d_space);
688 	dst->d_icount = src->d_ino_count;
689 	copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
690 			     src->d_ino_timer);
691 	copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
692 			     src->d_spc_timer);
693 	dst->d_iwarns = src->d_ino_warns;
694 	dst->d_bwarns = src->d_spc_warns;
695 	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
696 	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
697 	dst->d_rtbcount = quota_btobb(src->d_rt_space);
698 	copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
699 			     src->d_rt_spc_timer);
700 	dst->d_rtbwarns = src->d_rt_spc_warns;
701 }
702 
703 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
704 			   void __user *addr)
705 {
706 	struct fs_disk_quota fdq;
707 	struct qc_dqblk qdq;
708 	struct kqid qid;
709 	int ret;
710 
711 	if (!sb->s_qcop->get_dqblk)
712 		return -ENOSYS;
713 	qid = make_kqid(current_user_ns(), type, id);
714 	if (!qid_has_mapping(sb->s_user_ns, qid))
715 		return -EINVAL;
716 	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
717 	if (ret)
718 		return ret;
719 	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
720 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
721 		return -EFAULT;
722 	return ret;
723 }
724 
725 /*
726  * Return quota for next active quota >= this id, if any exists,
727  * otherwise return -ENOENT via ->get_nextdqblk.
728  */
729 static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
730 			    void __user *addr)
731 {
732 	struct fs_disk_quota fdq;
733 	struct qc_dqblk qdq;
734 	struct kqid qid;
735 	qid_t id_out;
736 	int ret;
737 
738 	if (!sb->s_qcop->get_nextdqblk)
739 		return -ENOSYS;
740 	qid = make_kqid(current_user_ns(), type, id);
741 	if (!qid_has_mapping(sb->s_user_ns, qid))
742 		return -EINVAL;
743 	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
744 	if (ret)
745 		return ret;
746 	id_out = from_kqid(current_user_ns(), qid);
747 	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
748 	if (copy_to_user(addr, &fdq, sizeof(fdq)))
749 		return -EFAULT;
750 	return ret;
751 }
752 
753 static int quota_rmxquota(struct super_block *sb, void __user *addr)
754 {
755 	__u32 flags;
756 
757 	if (copy_from_user(&flags, addr, sizeof(flags)))
758 		return -EFAULT;
759 	if (!sb->s_qcop->rm_xquota)
760 		return -ENOSYS;
761 	return sb->s_qcop->rm_xquota(sb, flags);
762 }
763 
764 /* Copy parameters and call proper function */
765 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
766 		       void __user *addr, const struct path *path)
767 {
768 	int ret;
769 
770 	type = array_index_nospec(type, MAXQUOTAS);
771 	/*
772 	 * Quota not supported on this fs? Check this before s_quota_types
773 	 * since they needn't be set if quota is not supported at all.
774 	 */
775 	if (!sb->s_qcop)
776 		return -ENOSYS;
777 	if (!(sb->s_quota_types & (1 << type)))
778 		return -EINVAL;
779 
780 	ret = check_quotactl_permission(sb, type, cmd, id);
781 	if (ret < 0)
782 		return ret;
783 
784 	switch (cmd) {
785 	case Q_QUOTAON:
786 		return quota_quotaon(sb, type, id, path);
787 	case Q_QUOTAOFF:
788 		return quota_quotaoff(sb, type);
789 	case Q_GETFMT:
790 		return quota_getfmt(sb, type, addr);
791 	case Q_GETINFO:
792 		return quota_getinfo(sb, type, addr);
793 	case Q_SETINFO:
794 		return quota_setinfo(sb, type, addr);
795 	case Q_GETQUOTA:
796 		return quota_getquota(sb, type, id, addr);
797 	case Q_GETNEXTQUOTA:
798 		return quota_getnextquota(sb, type, id, addr);
799 	case Q_SETQUOTA:
800 		return quota_setquota(sb, type, id, addr);
801 	case Q_SYNC:
802 		if (!sb->s_qcop->quota_sync)
803 			return -ENOSYS;
804 		return sb->s_qcop->quota_sync(sb, type);
805 	case Q_XQUOTAON:
806 		return quota_enable(sb, addr);
807 	case Q_XQUOTAOFF:
808 		return quota_disable(sb, addr);
809 	case Q_XQUOTARM:
810 		return quota_rmxquota(sb, addr);
811 	case Q_XGETQSTAT:
812 		return quota_getxstate(sb, type, addr);
813 	case Q_XGETQSTATV:
814 		return quota_getxstatev(sb, type, addr);
815 	case Q_XSETQLIM:
816 		return quota_setxquota(sb, type, id, addr);
817 	case Q_XGETQUOTA:
818 		return quota_getxquota(sb, type, id, addr);
819 	case Q_XGETNEXTQUOTA:
820 		return quota_getnextxquota(sb, type, id, addr);
821 	case Q_XQUOTASYNC:
822 		if (sb_rdonly(sb))
823 			return -EROFS;
824 		/* XFS quotas are fully coherent now, making this call a noop */
825 		return 0;
826 	default:
827 		return -EINVAL;
828 	}
829 }
830 
831 /* Return 1 if 'cmd' will block on frozen filesystem */
832 static int quotactl_cmd_write(int cmd)
833 {
834 	/*
835 	 * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
836 	 * as dquot_acquire() may allocate space for new structure and OCFS2
837 	 * needs to increment on-disk use count.
838 	 */
839 	switch (cmd) {
840 	case Q_GETFMT:
841 	case Q_GETINFO:
842 	case Q_SYNC:
843 	case Q_XGETQSTAT:
844 	case Q_XGETQSTATV:
845 	case Q_XGETQUOTA:
846 	case Q_XGETNEXTQUOTA:
847 	case Q_XQUOTASYNC:
848 		return 0;
849 	}
850 	return 1;
851 }
852 
853 /* Return true if quotactl command is manipulating quota on/off state */
854 static bool quotactl_cmd_onoff(int cmd)
855 {
856 	return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
857 		 (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);
858 }
859 
860 /*
861  * look up a superblock on which quota ops will be performed
862  * - use the name of a block device to find the superblock thereon
863  */
864 static struct super_block *quotactl_block(const char __user *special, int cmd)
865 {
866 #ifdef CONFIG_BLOCK
867 	struct super_block *sb;
868 	struct filename *tmp = getname(special);
869 	bool excl = false, thawed = false;
870 	int error;
871 	dev_t dev;
872 
873 	if (IS_ERR(tmp))
874 		return ERR_CAST(tmp);
875 	error = lookup_bdev(tmp->name, &dev);
876 	putname(tmp);
877 	if (error)
878 		return ERR_PTR(error);
879 
880 	if (quotactl_cmd_onoff(cmd)) {
881 		excl = true;
882 		thawed = true;
883 	} else if (quotactl_cmd_write(cmd)) {
884 		thawed = true;
885 	}
886 
887 retry:
888 	sb = user_get_super(dev, excl);
889 	if (!sb)
890 		return ERR_PTR(-ENODEV);
891 	if (thawed && sb->s_writers.frozen != SB_UNFROZEN) {
892 		if (excl)
893 			up_write(&sb->s_umount);
894 		else
895 			up_read(&sb->s_umount);
896 		wait_event(sb->s_writers.wait_unfrozen,
897 			   sb->s_writers.frozen == SB_UNFROZEN);
898 		put_super(sb);
899 		goto retry;
900 	}
901 	return sb;
902 
903 #else
904 	return ERR_PTR(-ENODEV);
905 #endif
906 }
907 
908 /*
909  * This is the system call interface. This communicates with
910  * the user-level programs. Currently this only supports diskquota
911  * calls. Maybe we need to add the process quotas etc. in the future,
912  * but we probably should use rlimits for that.
913  */
914 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
915 		qid_t, id, void __user *, addr)
916 {
917 	uint cmds, type;
918 	struct super_block *sb = NULL;
919 	struct path path, *pathp = NULL;
920 	int ret;
921 
922 	cmds = cmd >> SUBCMDSHIFT;
923 	type = cmd & SUBCMDMASK;
924 
925 	if (type >= MAXQUOTAS)
926 		return -EINVAL;
927 
928 	/*
929 	 * As a special case Q_SYNC can be called without a specific device.
930 	 * It will iterate all superblocks that have quota enabled and call
931 	 * the sync action on each of them.
932 	 */
933 	if (!special) {
934 		if (cmds == Q_SYNC)
935 			return quota_sync_all(type);
936 		return -ENODEV;
937 	}
938 
939 	/*
940 	 * Path for quotaon has to be resolved before grabbing superblock
941 	 * because that gets s_umount sem which is also possibly needed by path
942 	 * resolution (think about autofs) and thus deadlocks could arise.
943 	 */
944 	if (cmds == Q_QUOTAON) {
945 		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
946 		if (ret)
947 			pathp = ERR_PTR(ret);
948 		else
949 			pathp = &path;
950 	}
951 
952 	sb = quotactl_block(special, cmds);
953 	if (IS_ERR(sb)) {
954 		ret = PTR_ERR(sb);
955 		goto out;
956 	}
957 
958 	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
959 
960 	if (!quotactl_cmd_onoff(cmds))
961 		drop_super(sb);
962 	else
963 		drop_super_exclusive(sb);
964 out:
965 	if (pathp && !IS_ERR(pathp))
966 		path_put(pathp);
967 	return ret;
968 }
969 
970 SYSCALL_DEFINE4(quotactl_path, unsigned int, cmd, const char __user *,
971 		mountpoint, qid_t, id, void __user *, addr)
972 {
973 	struct super_block *sb;
974 	struct path mountpath;
975 	unsigned int cmds = cmd >> SUBCMDSHIFT;
976 	unsigned int type = cmd & SUBCMDMASK;
977 	int ret;
978 
979 	if (type >= MAXQUOTAS)
980 		return -EINVAL;
981 
982 	ret = user_path_at(AT_FDCWD, mountpoint,
983 			     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);
984 	if (ret)
985 		return ret;
986 
987 	sb = mountpath.mnt->mnt_sb;
988 
989 	if (quotactl_cmd_write(cmds)) {
990 		ret = mnt_want_write(mountpath.mnt);
991 		if (ret)
992 			goto out;
993 	}
994 
995 	if (quotactl_cmd_onoff(cmds))
996 		down_write(&sb->s_umount);
997 	else
998 		down_read(&sb->s_umount);
999 
1000 	ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
1001 
1002 	if (quotactl_cmd_onoff(cmds))
1003 		up_write(&sb->s_umount);
1004 	else
1005 		up_read(&sb->s_umount);
1006 
1007 	if (quotactl_cmd_write(cmds))
1008 		mnt_drop_write(mountpath.mnt);
1009 out:
1010 	path_put(&mountpath);
1011 
1012 	return ret;
1013 }
1014