| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame^] | 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); |