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
27static 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
54static 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
63static 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
73unsigned 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
86static 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
98static 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
107static 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
119static 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
147static 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
177static inline qsize_t qbtos(qsize_t blocks)
178{
179	return blocks << QIF_DQBLKSIZE_BITS;
180}
181
182static inline qsize_t stoqb(qsize_t space)
183{
184	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
185}
186
187static 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
201static 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 */
237static 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
261static 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
287static 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
313static 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
324static 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
335static 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
354static 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
407static 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
416static 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
434static 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
452static 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
497static 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
529static inline u64 quota_bbtob(u64 blocks)
530{
531	return blocks << XFS_BB_SHIFT;
532}
533
534static inline u64 quota_btobb(u64 bytes)
535{
536	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
537}
538
539static 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
547static 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
600static 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
624static 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
657static 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
665static inline bool want_bigtime(s64 timer)
666{
667	return timer > S32_MAX || timer < S32_MIN;
668}
669
670static 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
705static 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 */
731static 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
755static 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 */
767static 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 */
834static 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 */
856static 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 */
866static 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
889retry:
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 */
917SYSCALL_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);
967out:
968	if (pathp && !IS_ERR(pathp))
969		path_put(pathp);
970	return ret;
971}
972
973SYSCALL_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 (!f.file)
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(f.file->f_path.mnt);
992		if (ret)
993			goto out;
994	}
995
996	sb = f.file->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(f.file->f_path.mnt);
1011out:
1012	fdput(f);
1013	return ret;
1014}
1015