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