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 */
13 bool 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 }
28 EXPORT_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 */
37 bool 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 }
54 EXPORT_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 */
68 qid_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 }
81 EXPORT_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 */
101 qid_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 }
114 EXPORT_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 */
120 bool 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 }
133 EXPORT_SYMBOL(qid_valid);