xref: /openbmc/linux/fs/quota/kqid.c (revision b2441318)
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  */
qid_eq(struct kqid left,struct kqid right)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  */
qid_lt(struct kqid left,struct kqid right)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  */
from_kqid(struct user_namespace * targ,struct kqid kqid)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  */
from_kqid_munged(struct user_namespace * targ,struct kqid kqid)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  */
qid_valid(struct kqid qid)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);
134