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gerrit-public.fairphone.software / kernel / msm-4.9 / 76fb69a07427ac5bb34f4ca776a10a2ff392a340 / . / fs / quota / kqid.c
blob: ebc5e62858007d8f9ed6acee5f6aef2afb28c9c0 [file] [log] [blame]
Eric W. Biedermane8a3e472012-09-16 01:11:45 -0700[diff] [blame]1#include <linux/fs.h>
2#include <linux/quota.h>
3#include <linux/export.h>
4
5/**
6 * qid_eq - Test to see if to kquid values are the same
7 * @left: A qid value
8 * @right: Another quid value
9 *
10 * Return true if the two qid values are equal and false otherwise.
11 */
12bool qid_eq(struct kqid left, struct kqid right)
13{
14 if (left.type != right.type)
15 return false;
16 switch(left.type) {
17 case USRQUOTA:
18 return uid_eq(left.uid, right.uid);
19 case GRPQUOTA:
20 return gid_eq(left.gid, right.gid);
21 case PRJQUOTA:
22 return projid_eq(left.projid, right.projid);
23 default:
24 BUG();
25 }
26}
27EXPORT_SYMBOL(qid_eq);
28
29/**
30 * qid_lt - Test to see if one qid value is less than another
31 * @left: The possibly lesser qid value
32 * @right: The possibly greater qid value
33 *
34 * Return true if left is less than right and false otherwise.
35 */
36bool qid_lt(struct kqid left, struct kqid right)
37{
38 if (left.type < right.type)
39 return true;
40 if (left.type > right.type)
41 return false;
42 switch (left.type) {
43 case USRQUOTA:
44 return uid_lt(left.uid, right.uid);
45 case GRPQUOTA:
46 return gid_lt(left.gid, right.gid);
47 case PRJQUOTA:
48 return projid_lt(left.projid, right.projid);
49 default:
50 BUG();
51 }
52}
53EXPORT_SYMBOL(qid_lt);
54
55/**
56 * from_kqid - Create a qid from a kqid user-namespace pair.
57 * @targ: The user namespace we want a qid in.
Fabian Frederick2c15ac52014-07-04 21:44:25 +0200[diff] [blame]58 * @kqid: The kernel internal quota identifier to start with.
Eric W. Biedermane8a3e472012-09-16 01:11:45 -0700[diff] [blame]59 *
60 * Map @kqid into the user-namespace specified by @targ and
61 * return the resulting qid.
62 *
63 * There is always a mapping into the initial user_namespace.
64 *
65 * If @kqid has no mapping in @targ (qid_t)-1 is returned.
66 */
67qid_t from_kqid(struct user_namespace *targ, struct kqid kqid)
68{
69 switch (kqid.type) {
70 case USRQUOTA:
71 return from_kuid(targ, kqid.uid);
72 case GRPQUOTA:
73 return from_kgid(targ, kqid.gid);
74 case PRJQUOTA:
75 return from_kprojid(targ, kqid.projid);
76 default:
77 BUG();
78 }
79}
80EXPORT_SYMBOL(from_kqid);
81
82/**
83 * from_kqid_munged - Create a qid from a kqid user-namespace pair.
84 * @targ: The user namespace we want a qid in.
85 * @kqid: The kernel internal quota identifier to start with.
86 *
87 * Map @kqid into the user-namespace specified by @targ and
88 * return the resulting qid.
89 *
90 * There is always a mapping into the initial user_namespace.
91 *
92 * Unlike from_kqid from_kqid_munged never fails and always
93 * returns a valid projid. This makes from_kqid_munged
94 * appropriate for use in places where failing to provide
95 * a qid_t is not a good option.
96 *
97 * If @kqid has no mapping in @targ the kqid.type specific
98 * overflow identifier is returned.
99 */
100qid_t from_kqid_munged(struct user_namespace *targ, struct kqid kqid)
101{
102 switch (kqid.type) {
103 case USRQUOTA:
104 return from_kuid_munged(targ, kqid.uid);
105 case GRPQUOTA:
106 return from_kgid_munged(targ, kqid.gid);
107 case PRJQUOTA:
108 return from_kprojid_munged(targ, kqid.projid);
109 default:
110 BUG();
111 }
112}
113EXPORT_SYMBOL(from_kqid_munged);
114
115/**
116 * qid_valid - Report if a valid value is stored in a kqid.
117 * @qid: The kernel internal quota identifier to test.
118 */
119bool qid_valid(struct kqid qid)
120{
121 switch (qid.type) {
122 case USRQUOTA:
123 return uid_valid(qid.uid);
124 case GRPQUOTA:
125 return gid_valid(qid.gid);
126 case PRJQUOTA:
127 return projid_valid(qid.projid);
128 default:
129 BUG();
130 }
131}
132EXPORT_SYMBOL(qid_valid);