1// SPDX-License-Identifier: GPL-2.0
2#include <linux/fs.h>
3#include <linux/quota.h>
4#include <linux/export.h>
5
6/**
7 *	qid_eq - Test to see if to kquid values are the same
8 *	@left: A qid value
9 *	@right: Another quid value
10 *
11 *	Return true if the two qid values are equal and false otherwise.
12 */
13bool qid_eq(struct kqid left, struct kqid right)
14{
15	if (left.type != right.type)
16		return false;
17	switch(left.type) {
18	case USRQUOTA:
19		return uid_eq(left.uid, right.uid);
20	case GRPQUOTA:
21		return gid_eq(left.gid, right.gid);
22	case PRJQUOTA:
23		return projid_eq(left.projid, right.projid);
24	default:
25		BUG();
26	}
27}
28EXPORT_SYMBOL(qid_eq);
29
30/**
31 *	qid_lt - Test to see if one qid value is less than another
32 *	@left: The possibly lesser qid value
33 *	@right: The possibly greater qid value
34 *
35 *	Return true if left is less than right and false otherwise.
36 */
37bool qid_lt(struct kqid left, struct kqid right)
38{
39	if (left.type < right.type)
40		return true;
41	if (left.type > right.type)
42		return false;
43	switch (left.type) {
44	case USRQUOTA:
45		return uid_lt(left.uid, right.uid);
46	case GRPQUOTA:
47		return gid_lt(left.gid, right.gid);
48	case PRJQUOTA:
49		return projid_lt(left.projid, right.projid);
50	default:
51		BUG();
52	}
53}
54EXPORT_SYMBOL(qid_lt);
55
56/**
57 *	from_kqid - Create a qid from a kqid user-namespace pair.
58 *	@targ: The user namespace we want a qid in.
59 *	@kqid: The kernel internal quota identifier to start with.
60 *
61 *	Map @kqid into the user-namespace specified by @targ and
62 *	return the resulting qid.
63 *
64 *	There is always a mapping into the initial user_namespace.
65 *
66 *	If @kqid has no mapping in @targ (qid_t)-1 is returned.
67 */
68qid_t from_kqid(struct user_namespace *targ, struct kqid kqid)
69{
70	switch (kqid.type) {
71	case USRQUOTA:
72		return from_kuid(targ, kqid.uid);
73	case GRPQUOTA:
74		return from_kgid(targ, kqid.gid);
75	case PRJQUOTA:
76		return from_kprojid(targ, kqid.projid);
77	default:
78		BUG();
79	}
80}
81EXPORT_SYMBOL(from_kqid);
82
83/**
84 *	from_kqid_munged - Create a qid from a kqid user-namespace pair.
85 *	@targ: The user namespace we want a qid in.
86 *	@kqid: The kernel internal quota identifier to start with.
87 *
88 *	Map @kqid into the user-namespace specified by @targ and
89 *	return the resulting qid.
90 *
91 *	There is always a mapping into the initial user_namespace.
92 *
93 *	Unlike from_kqid from_kqid_munged never fails and always
94 *	returns a valid projid.  This makes from_kqid_munged
95 *	appropriate for use in places where failing to provide
96 *	a qid_t is not a good option.
97 *
98 *	If @kqid has no mapping in @targ the kqid.type specific
99 *	overflow identifier is returned.
100 */
101qid_t from_kqid_munged(struct user_namespace *targ, struct kqid kqid)
102{
103	switch (kqid.type) {
104	case USRQUOTA:
105		return from_kuid_munged(targ, kqid.uid);
106	case GRPQUOTA:
107		return from_kgid_munged(targ, kqid.gid);
108	case PRJQUOTA:
109		return from_kprojid_munged(targ, kqid.projid);
110	default:
111		BUG();
112	}
113}
114EXPORT_SYMBOL(from_kqid_munged);
115
116/**
117 *	qid_valid - Report if a valid value is stored in a kqid.
118 *	@qid: The kernel internal quota identifier to test.
119 */
120bool qid_valid(struct kqid qid)
121{
122	switch (qid.type) {
123	case USRQUOTA:
124		return uid_valid(qid.uid);
125	case GRPQUOTA:
126		return gid_valid(qid.gid);
127	case PRJQUOTA:
128		return projid_valid(qid.projid);
129	default:
130		BUG();
131	}
132}
133EXPORT_SYMBOL(qid_valid);
134