1/*
2 * Quota code necessary even when VFS quota support is not compiled
3 * into the kernel.  The interesting stuff is over in dquot.c, here
4 * we have symbols for initial quotactl(2) handling, the sysctl(2)
5 * variables, etc - things needed even when quota support disabled.
6 */
7
8#include <linux/fs.h>
9#include <linux/namei.h>
10#include <linux/slab.h>
11#include <asm/current.h>
12#include <linux/uaccess.h>
13#include <linux/kernel.h>
14#include <linux/security.h>
15#include <linux/syscalls.h>
16#include <linux/capability.h>
17#include <linux/quotaops.h>
18#include <linux/types.h>
19#include <linux/writeback.h>
20
21static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
22				     qid_t id)
23{
24	switch (cmd) {
25	/* these commands do not require any special privilegues */
26	case Q_GETFMT:
27	case Q_SYNC:
28	case Q_GETINFO:
29	case Q_XGETQSTAT:
30	case Q_XGETQSTATV:
31	case Q_XQUOTASYNC:
32		break;
33	/* allow to query information for dquots we "own" */
34	case Q_GETQUOTA:
35	case Q_XGETQUOTA:
36		if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
37		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
38			break;
39		/*FALLTHROUGH*/
40	default:
41		if (!capable(CAP_SYS_ADMIN))
42			return -EPERM;
43	}
44
45	return security_quotactl(cmd, type, id, sb);
46}
47
48static void quota_sync_one(struct super_block *sb, void *arg)
49{
50	int type = *(int *)arg;
51
52	if (sb->s_qcop && sb->s_qcop->quota_sync &&
53	    (sb->s_quota_types & (1 << type)))
54		sb->s_qcop->quota_sync(sb, type);
55}
56
57static int quota_sync_all(int type)
58{
59	int ret;
60
61	if (type >= MAXQUOTAS)
62		return -EINVAL;
63	ret = security_quotactl(Q_SYNC, type, 0, NULL);
64	if (!ret)
65		iterate_supers(quota_sync_one, &type);
66	return ret;
67}
68
69unsigned int qtype_enforce_flag(int type)
70{
71	switch (type) {
72	case USRQUOTA:
73		return FS_QUOTA_UDQ_ENFD;
74	case GRPQUOTA:
75		return FS_QUOTA_GDQ_ENFD;
76	case PRJQUOTA:
77		return FS_QUOTA_PDQ_ENFD;
78	}
79	return 0;
80}
81
82static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
83		         struct path *path)
84{
85	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
86		return -ENOSYS;
87	if (sb->s_qcop->quota_enable)
88		return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));
89	if (IS_ERR(path))
90		return PTR_ERR(path);
91	return sb->s_qcop->quota_on(sb, type, id, path);
92}
93
94static int quota_quotaoff(struct super_block *sb, int type)
95{
96	if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
97		return -ENOSYS;
98	if (sb->s_qcop->quota_disable)
99		return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
100	return sb->s_qcop->quota_off(sb, type);
101}
102
103static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
104{
105	__u32 fmt;
106
107	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
108	if (!sb_has_quota_active(sb, type)) {
109		mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
110		return -ESRCH;
111	}
112	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
113	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
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	/* This checks whether qc_state has enough entries... */
127	BUILD_BUG_ON(MAXQUOTAS > XQM_MAXQUOTAS);
128	if (!sb->s_qcop->get_state)
129		return -ENOSYS;
130	ret = sb->s_qcop->get_state(sb, &state);
131	if (ret)
132		return ret;
133	tstate = state.s_state + type;
134	if (!(tstate->flags & QCI_ACCT_ENABLED))
135		return -ESRCH;
136	memset(&uinfo, 0, sizeof(uinfo));
137	uinfo.dqi_bgrace = tstate->spc_timelimit;
138	uinfo.dqi_igrace = tstate->ino_timelimit;
139	if (tstate->flags & QCI_SYSFILE)
140		uinfo.dqi_flags |= DQF_SYS_FILE;
141	if (tstate->flags & QCI_ROOT_SQUASH)
142		uinfo.dqi_flags |= DQF_ROOT_SQUASH;
143	uinfo.dqi_valid = IIF_ALL;
144	if (!ret && copy_to_user(addr, &uinfo, sizeof(uinfo)))
145		return -EFAULT;
146	return ret;
147}
148
149static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
150{
151	struct if_dqinfo info;
152	struct qc_info qinfo;
153
154	if (copy_from_user(&info, addr, sizeof(info)))
155		return -EFAULT;
156	if (!sb->s_qcop->set_info)
157		return -ENOSYS;
158	if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
159		return -EINVAL;
160	memset(&qinfo, 0, sizeof(qinfo));
161	if (info.dqi_valid & IIF_FLAGS) {
162		if (info.dqi_flags & ~DQF_SETINFO_MASK)
163			return -EINVAL;
164		if (info.dqi_flags & DQF_ROOT_SQUASH)
165			qinfo.i_flags |= QCI_ROOT_SQUASH;
166		qinfo.i_fieldmask |= QC_FLAGS;
167	}
168	if (info.dqi_valid & IIF_BGRACE) {
169		qinfo.i_spc_timelimit = info.dqi_bgrace;
170		qinfo.i_fieldmask |= QC_SPC_TIMER;
171	}
172	if (info.dqi_valid & IIF_IGRACE) {
173		qinfo.i_ino_timelimit = info.dqi_igrace;
174		qinfo.i_fieldmask |= QC_INO_TIMER;
175	}
176	return sb->s_qcop->set_info(sb, type, &qinfo);
177}
178
179static inline qsize_t qbtos(qsize_t blocks)
180{
181	return blocks << QIF_DQBLKSIZE_BITS;
182}
183
184static inline qsize_t stoqb(qsize_t space)
185{
186	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
187}
188
189static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)
190{
191	memset(dst, 0, sizeof(*dst));
192	dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
193	dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
194	dst->dqb_curspace = src->d_space;
195	dst->dqb_ihardlimit = src->d_ino_hardlimit;
196	dst->dqb_isoftlimit = src->d_ino_softlimit;
197	dst->dqb_curinodes = src->d_ino_count;
198	dst->dqb_btime = src->d_spc_timer;
199	dst->dqb_itime = src->d_ino_timer;
200	dst->dqb_valid = QIF_ALL;
201}
202
203static int quota_getquota(struct super_block *sb, int type, qid_t id,
204			  void __user *addr)
205{
206	struct kqid qid;
207	struct qc_dqblk fdq;
208	struct if_dqblk idq;
209	int ret;
210
211	if (!sb->s_qcop->get_dqblk)
212		return -ENOSYS;
213	qid = make_kqid(current_user_ns(), type, id);
214	if (!qid_valid(qid))
215		return -EINVAL;
216	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
217	if (ret)
218		return ret;
219	copy_to_if_dqblk(&idq, &fdq);
220	if (copy_to_user(addr, &idq, sizeof(idq)))
221		return -EFAULT;
222	return 0;
223}
224
225static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
226{
227	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
228	dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
229	dst->d_space = src->dqb_curspace;
230	dst->d_ino_hardlimit = src->dqb_ihardlimit;
231	dst->d_ino_softlimit = src->dqb_isoftlimit;
232	dst->d_ino_count = src->dqb_curinodes;
233	dst->d_spc_timer = src->dqb_btime;
234	dst->d_ino_timer = src->dqb_itime;
235
236	dst->d_fieldmask = 0;
237	if (src->dqb_valid & QIF_BLIMITS)
238		dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;
239	if (src->dqb_valid & QIF_SPACE)
240		dst->d_fieldmask |= QC_SPACE;
241	if (src->dqb_valid & QIF_ILIMITS)
242		dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;
243	if (src->dqb_valid & QIF_INODES)
244		dst->d_fieldmask |= QC_INO_COUNT;
245	if (src->dqb_valid & QIF_BTIME)
246		dst->d_fieldmask |= QC_SPC_TIMER;
247	if (src->dqb_valid & QIF_ITIME)
248		dst->d_fieldmask |= QC_INO_TIMER;
249}
250
251static int quota_setquota(struct super_block *sb, int type, qid_t id,
252			  void __user *addr)
253{
254	struct qc_dqblk fdq;
255	struct if_dqblk idq;
256	struct kqid qid;
257
258	if (copy_from_user(&idq, addr, sizeof(idq)))
259		return -EFAULT;
260	if (!sb->s_qcop->set_dqblk)
261		return -ENOSYS;
262	qid = make_kqid(current_user_ns(), type, id);
263	if (!qid_valid(qid))
264		return -EINVAL;
265	copy_from_if_dqblk(&fdq, &idq);
266	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
267}
268
269static int quota_enable(struct super_block *sb, void __user *addr)
270{
271	__u32 flags;
272
273	if (copy_from_user(&flags, addr, sizeof(flags)))
274		return -EFAULT;
275	if (!sb->s_qcop->quota_enable)
276		return -ENOSYS;
277	return sb->s_qcop->quota_enable(sb, flags);
278}
279
280static int quota_disable(struct super_block *sb, void __user *addr)
281{
282	__u32 flags;
283
284	if (copy_from_user(&flags, addr, sizeof(flags)))
285		return -EFAULT;
286	if (!sb->s_qcop->quota_disable)
287		return -ENOSYS;
288	return sb->s_qcop->quota_disable(sb, flags);
289}
290
291static int quota_state_to_flags(struct qc_state *state)
292{
293	int flags = 0;
294
295	if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
296		flags |= FS_QUOTA_UDQ_ACCT;
297	if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
298		flags |= FS_QUOTA_UDQ_ENFD;
299	if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
300		flags |= FS_QUOTA_GDQ_ACCT;
301	if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
302		flags |= FS_QUOTA_GDQ_ENFD;
303	if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
304		flags |= FS_QUOTA_PDQ_ACCT;
305	if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
306		flags |= FS_QUOTA_PDQ_ENFD;
307	return flags;
308}
309
310static int quota_getstate(struct super_block *sb, struct fs_quota_stat *fqs)
311{
312	int type;
313	struct qc_state state;
314	int ret;
315
316	ret = sb->s_qcop->get_state(sb, &state);
317	if (ret < 0)
318		return ret;
319
320	memset(fqs, 0, sizeof(*fqs));
321	fqs->qs_version = FS_QSTAT_VERSION;
322	fqs->qs_flags = quota_state_to_flags(&state);
323	/* No quota enabled? */
324	if (!fqs->qs_flags)
325		return -ENOSYS;
326	fqs->qs_incoredqs = state.s_incoredqs;
327	/*
328	 * GETXSTATE quotactl has space for just one set of time limits so
329	 * report them for the first enabled quota type
330	 */
331	for (type = 0; type < XQM_MAXQUOTAS; type++)
332		if (state.s_state[type].flags & QCI_ACCT_ENABLED)
333			break;
334	BUG_ON(type == XQM_MAXQUOTAS);
335	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
336	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
337	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
338	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
339	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
340	if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
341		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
342		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
343		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
344	}
345	if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
346		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
347		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
348		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
349	}
350	if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
351		/*
352		 * Q_XGETQSTAT doesn't have room for both group and project
353		 * quotas.  So, allow the project quota values to be copied out
354		 * only if there is no group quota information available.
355		 */
356		if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
357			fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
358			fqs->qs_gquota.qfs_nblks =
359					state.s_state[PRJQUOTA].blocks;
360			fqs->qs_gquota.qfs_nextents =
361					state.s_state[PRJQUOTA].nextents;
362		}
363	}
364	return 0;
365}
366
367static int quota_getxstate(struct super_block *sb, void __user *addr)
368{
369	struct fs_quota_stat fqs;
370	int ret;
371
372	if (!sb->s_qcop->get_state)
373		return -ENOSYS;
374	ret = quota_getstate(sb, &fqs);
375	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
376		return -EFAULT;
377	return ret;
378}
379
380static int quota_getstatev(struct super_block *sb, struct fs_quota_statv *fqs)
381{
382	int type;
383	struct qc_state state;
384	int ret;
385
386	ret = sb->s_qcop->get_state(sb, &state);
387	if (ret < 0)
388		return ret;
389
390	memset(fqs, 0, sizeof(*fqs));
391	fqs->qs_version = FS_QSTAT_VERSION;
392	fqs->qs_flags = quota_state_to_flags(&state);
393	/* No quota enabled? */
394	if (!fqs->qs_flags)
395		return -ENOSYS;
396	fqs->qs_incoredqs = state.s_incoredqs;
397	/*
398	 * GETXSTATV quotactl has space for just one set of time limits so
399	 * report them for the first enabled quota type
400	 */
401	for (type = 0; type < XQM_MAXQUOTAS; type++)
402		if (state.s_state[type].flags & QCI_ACCT_ENABLED)
403			break;
404	BUG_ON(type == XQM_MAXQUOTAS);
405	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
406	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
407	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
408	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
409	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;
410	if (state.s_state[USRQUOTA].flags & QCI_ACCT_ENABLED) {
411		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
412		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
413		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
414	}
415	if (state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED) {
416		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
417		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
418		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
419	}
420	if (state.s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED) {
421		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
422		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
423		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
424	}
425	return 0;
426}
427
428static int quota_getxstatev(struct super_block *sb, void __user *addr)
429{
430	struct fs_quota_statv fqs;
431	int ret;
432
433	if (!sb->s_qcop->get_state)
434		return -ENOSYS;
435
436	memset(&fqs, 0, sizeof(fqs));
437	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
438		return -EFAULT;
439
440	/* If this kernel doesn't support user specified version, fail */
441	switch (fqs.qs_version) {
442	case FS_QSTATV_VERSION1:
443		break;
444	default:
445		return -EINVAL;
446	}
447	ret = quota_getstatev(sb, &fqs);
448	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
449		return -EFAULT;
450	return ret;
451}
452
453/*
454 * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
455 * out of there as xfsprogs rely on definitions being in that header file. So
456 * just define same functions here for quota purposes.
457 */
458#define XFS_BB_SHIFT 9
459
460static inline u64 quota_bbtob(u64 blocks)
461{
462	return blocks << XFS_BB_SHIFT;
463}
464
465static inline u64 quota_btobb(u64 bytes)
466{
467	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
468}
469
470static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
471{
472	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
473	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
474	dst->d_ino_hardlimit = src->d_ino_hardlimit;
475	dst->d_ino_softlimit = src->d_ino_softlimit;
476	dst->d_space = quota_bbtob(src->d_bcount);
477	dst->d_ino_count = src->d_icount;
478	dst->d_ino_timer = src->d_itimer;
479	dst->d_spc_timer = src->d_btimer;
480	dst->d_ino_warns = src->d_iwarns;
481	dst->d_spc_warns = src->d_bwarns;
482	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
483	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
484	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
485	dst->d_rt_spc_timer = src->d_rtbtimer;
486	dst->d_rt_spc_warns = src->d_rtbwarns;
487	dst->d_fieldmask = 0;
488	if (src->d_fieldmask & FS_DQ_ISOFT)
489		dst->d_fieldmask |= QC_INO_SOFT;
490	if (src->d_fieldmask & FS_DQ_IHARD)
491		dst->d_fieldmask |= QC_INO_HARD;
492	if (src->d_fieldmask & FS_DQ_BSOFT)
493		dst->d_fieldmask |= QC_SPC_SOFT;
494	if (src->d_fieldmask & FS_DQ_BHARD)
495		dst->d_fieldmask |= QC_SPC_HARD;
496	if (src->d_fieldmask & FS_DQ_RTBSOFT)
497		dst->d_fieldmask |= QC_RT_SPC_SOFT;
498	if (src->d_fieldmask & FS_DQ_RTBHARD)
499		dst->d_fieldmask |= QC_RT_SPC_HARD;
500	if (src->d_fieldmask & FS_DQ_BTIMER)
501		dst->d_fieldmask |= QC_SPC_TIMER;
502	if (src->d_fieldmask & FS_DQ_ITIMER)
503		dst->d_fieldmask |= QC_INO_TIMER;
504	if (src->d_fieldmask & FS_DQ_RTBTIMER)
505		dst->d_fieldmask |= QC_RT_SPC_TIMER;
506	if (src->d_fieldmask & FS_DQ_BWARNS)
507		dst->d_fieldmask |= QC_SPC_WARNS;
508	if (src->d_fieldmask & FS_DQ_IWARNS)
509		dst->d_fieldmask |= QC_INO_WARNS;
510	if (src->d_fieldmask & FS_DQ_RTBWARNS)
511		dst->d_fieldmask |= QC_RT_SPC_WARNS;
512	if (src->d_fieldmask & FS_DQ_BCOUNT)
513		dst->d_fieldmask |= QC_SPACE;
514	if (src->d_fieldmask & FS_DQ_ICOUNT)
515		dst->d_fieldmask |= QC_INO_COUNT;
516	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
517		dst->d_fieldmask |= QC_RT_SPACE;
518}
519
520static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
521				       struct fs_disk_quota *src)
522{
523	memset(dst, 0, sizeof(*dst));
524	dst->i_spc_timelimit = src->d_btimer;
525	dst->i_ino_timelimit = src->d_itimer;
526	dst->i_rt_spc_timelimit = src->d_rtbtimer;
527	dst->i_ino_warnlimit = src->d_iwarns;
528	dst->i_spc_warnlimit = src->d_bwarns;
529	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
530	if (src->d_fieldmask & FS_DQ_BWARNS)
531		dst->i_fieldmask |= QC_SPC_WARNS;
532	if (src->d_fieldmask & FS_DQ_IWARNS)
533		dst->i_fieldmask |= QC_INO_WARNS;
534	if (src->d_fieldmask & FS_DQ_RTBWARNS)
535		dst->i_fieldmask |= QC_RT_SPC_WARNS;
536	if (src->d_fieldmask & FS_DQ_BTIMER)
537		dst->i_fieldmask |= QC_SPC_TIMER;
538	if (src->d_fieldmask & FS_DQ_ITIMER)
539		dst->i_fieldmask |= QC_INO_TIMER;
540	if (src->d_fieldmask & FS_DQ_RTBTIMER)
541		dst->i_fieldmask |= QC_RT_SPC_TIMER;
542}
543
544static int quota_setxquota(struct super_block *sb, int type, qid_t id,
545			   void __user *addr)
546{
547	struct fs_disk_quota fdq;
548	struct qc_dqblk qdq;
549	struct kqid qid;
550
551	if (copy_from_user(&fdq, addr, sizeof(fdq)))
552		return -EFAULT;
553	if (!sb->s_qcop->set_dqblk)
554		return -ENOSYS;
555	qid = make_kqid(current_user_ns(), type, id);
556	if (!qid_valid(qid))
557		return -EINVAL;
558	/* Are we actually setting timer / warning limits for all users? */
559	if (from_kqid(&init_user_ns, qid) == 0 &&
560	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
561		struct qc_info qinfo;
562		int ret;
563
564		if (!sb->s_qcop->set_info)
565			return -EINVAL;
566		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
567		ret = sb->s_qcop->set_info(sb, type, &qinfo);
568		if (ret)
569			return ret;
570		/* These are already done */
571		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
572	}
573	copy_from_xfs_dqblk(&qdq, &fdq);
574	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
575}
576
577static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
578			      int type, qid_t id)
579{
580	memset(dst, 0, sizeof(*dst));
581	dst->d_version = FS_DQUOT_VERSION;
582	dst->d_id = id;
583	if (type == USRQUOTA)
584		dst->d_flags = FS_USER_QUOTA;
585	else if (type == PRJQUOTA)
586		dst->d_flags = FS_PROJ_QUOTA;
587	else
588		dst->d_flags = FS_GROUP_QUOTA;
589	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
590	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
591	dst->d_ino_hardlimit = src->d_ino_hardlimit;
592	dst->d_ino_softlimit = src->d_ino_softlimit;
593	dst->d_bcount = quota_btobb(src->d_space);
594	dst->d_icount = src->d_ino_count;
595	dst->d_itimer = src->d_ino_timer;
596	dst->d_btimer = src->d_spc_timer;
597	dst->d_iwarns = src->d_ino_warns;
598	dst->d_bwarns = src->d_spc_warns;
599	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
600	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
601	dst->d_rtbcount = quota_btobb(src->d_rt_space);
602	dst->d_rtbtimer = src->d_rt_spc_timer;
603	dst->d_rtbwarns = src->d_rt_spc_warns;
604}
605
606static int quota_getxquota(struct super_block *sb, int type, qid_t id,
607			   void __user *addr)
608{
609	struct fs_disk_quota fdq;
610	struct qc_dqblk qdq;
611	struct kqid qid;
612	int ret;
613
614	if (!sb->s_qcop->get_dqblk)
615		return -ENOSYS;
616	qid = make_kqid(current_user_ns(), type, id);
617	if (!qid_valid(qid))
618		return -EINVAL;
619	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
620	if (ret)
621		return ret;
622	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
623	if (copy_to_user(addr, &fdq, sizeof(fdq)))
624		return -EFAULT;
625	return ret;
626}
627
628static int quota_rmxquota(struct super_block *sb, void __user *addr)
629{
630	__u32 flags;
631
632	if (copy_from_user(&flags, addr, sizeof(flags)))
633		return -EFAULT;
634	if (!sb->s_qcop->rm_xquota)
635		return -ENOSYS;
636	return sb->s_qcop->rm_xquota(sb, flags);
637}
638
639/* Copy parameters and call proper function */
640static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
641		       void __user *addr, struct path *path)
642{
643	int ret;
644
645	if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
646		return -EINVAL;
647	/*
648	 * Quota not supported on this fs? Check this before s_quota_types
649	 * since they needn't be set if quota is not supported at all.
650	 */
651	if (!sb->s_qcop)
652		return -ENOSYS;
653	if (!(sb->s_quota_types & (1 << type)))
654		return -EINVAL;
655
656	ret = check_quotactl_permission(sb, type, cmd, id);
657	if (ret < 0)
658		return ret;
659
660	switch (cmd) {
661	case Q_QUOTAON:
662		return quota_quotaon(sb, type, cmd, id, path);
663	case Q_QUOTAOFF:
664		return quota_quotaoff(sb, type);
665	case Q_GETFMT:
666		return quota_getfmt(sb, type, addr);
667	case Q_GETINFO:
668		return quota_getinfo(sb, type, addr);
669	case Q_SETINFO:
670		return quota_setinfo(sb, type, addr);
671	case Q_GETQUOTA:
672		return quota_getquota(sb, type, id, addr);
673	case Q_SETQUOTA:
674		return quota_setquota(sb, type, id, addr);
675	case Q_SYNC:
676		if (!sb->s_qcop->quota_sync)
677			return -ENOSYS;
678		return sb->s_qcop->quota_sync(sb, type);
679	case Q_XQUOTAON:
680		return quota_enable(sb, addr);
681	case Q_XQUOTAOFF:
682		return quota_disable(sb, addr);
683	case Q_XQUOTARM:
684		return quota_rmxquota(sb, addr);
685	case Q_XGETQSTAT:
686		return quota_getxstate(sb, addr);
687	case Q_XGETQSTATV:
688		return quota_getxstatev(sb, addr);
689	case Q_XSETQLIM:
690		return quota_setxquota(sb, type, id, addr);
691	case Q_XGETQUOTA:
692		return quota_getxquota(sb, type, id, addr);
693	case Q_XQUOTASYNC:
694		if (sb->s_flags & MS_RDONLY)
695			return -EROFS;
696		/* XFS quotas are fully coherent now, making this call a noop */
697		return 0;
698	default:
699		return -EINVAL;
700	}
701}
702
703#ifdef CONFIG_BLOCK
704
705/* Return 1 if 'cmd' will block on frozen filesystem */
706static int quotactl_cmd_write(int cmd)
707{
708	switch (cmd) {
709	case Q_GETFMT:
710	case Q_GETINFO:
711	case Q_SYNC:
712	case Q_XGETQSTAT:
713	case Q_XGETQSTATV:
714	case Q_XGETQUOTA:
715	case Q_XQUOTASYNC:
716		return 0;
717	}
718	return 1;
719}
720
721#endif /* CONFIG_BLOCK */
722
723/*
724 * look up a superblock on which quota ops will be performed
725 * - use the name of a block device to find the superblock thereon
726 */
727static struct super_block *quotactl_block(const char __user *special, int cmd)
728{
729#ifdef CONFIG_BLOCK
730	struct block_device *bdev;
731	struct super_block *sb;
732	struct filename *tmp = getname(special);
733
734	if (IS_ERR(tmp))
735		return ERR_CAST(tmp);
736	bdev = lookup_bdev(tmp->name);
737	putname(tmp);
738	if (IS_ERR(bdev))
739		return ERR_CAST(bdev);
740	if (quotactl_cmd_write(cmd))
741		sb = get_super_thawed(bdev);
742	else
743		sb = get_super(bdev);
744	bdput(bdev);
745	if (!sb)
746		return ERR_PTR(-ENODEV);
747
748	return sb;
749#else
750	return ERR_PTR(-ENODEV);
751#endif
752}
753
754/*
755 * This is the system call interface. This communicates with
756 * the user-level programs. Currently this only supports diskquota
757 * calls. Maybe we need to add the process quotas etc. in the future,
758 * but we probably should use rlimits for that.
759 */
760SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
761		qid_t, id, void __user *, addr)
762{
763	uint cmds, type;
764	struct super_block *sb = NULL;
765	struct path path, *pathp = NULL;
766	int ret;
767
768	cmds = cmd >> SUBCMDSHIFT;
769	type = cmd & SUBCMDMASK;
770
771	/*
772	 * As a special case Q_SYNC can be called without a specific device.
773	 * It will iterate all superblocks that have quota enabled and call
774	 * the sync action on each of them.
775	 */
776	if (!special) {
777		if (cmds == Q_SYNC)
778			return quota_sync_all(type);
779		return -ENODEV;
780	}
781
782	/*
783	 * Path for quotaon has to be resolved before grabbing superblock
784	 * because that gets s_umount sem which is also possibly needed by path
785	 * resolution (think about autofs) and thus deadlocks could arise.
786	 */
787	if (cmds == Q_QUOTAON) {
788		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
789		if (ret)
790			pathp = ERR_PTR(ret);
791		else
792			pathp = &path;
793	}
794
795	sb = quotactl_block(special, cmds);
796	if (IS_ERR(sb)) {
797		ret = PTR_ERR(sb);
798		goto out;
799	}
800
801	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
802
803	drop_super(sb);
804out:
805	if (pathp && !IS_ERR(pathp))
806		path_put(pathp);
807	return ret;
808}
809