1 files changed, 132 insertions, 0 deletions

diff --git a/fs/quota/kqid.c b/fs/quota/kqid.c
new file mode 100644
index 000000000000..2f97b0e2c501
--- /dev/null
+++ b/fs/quota/kqid.c
@@ -0,0 +1,132 @@
+#include <linux/fs.h>
+#include <linux/quota.h>
+#include <linux/export.h>
+
+/**
+ *      qid_eq - Test to see if to kquid values are the same
+ *      @left: A qid value
+ *      @right: Another quid value
+ *
+ *      Return true if the two qid values are equal and false otherwise.
+ */
+bool qid_eq(struct kqid left, struct kqid right)
+{
+        if (left.type != right.type)
+                return false;
+        switch(left.type) {
+        case USRQUOTA:
+                return uid_eq(left.uid, right.uid);
+        case GRPQUOTA:
+                return gid_eq(left.gid, right.gid);
+        case PRJQUOTA:
+                return projid_eq(left.projid, right.projid);
+        default:
+                BUG();
+        }
+}
+EXPORT_SYMBOL(qid_eq);
+
+/**
+ *      qid_lt - Test to see if one qid value is less than another
+ *      @left: The possibly lesser qid value
+ *      @right: The possibly greater qid value
+ *
+ *      Return true if left is less than right and false otherwise.
+ */
+bool qid_lt(struct kqid left, struct kqid right)
+{
+        if (left.type < right.type)
+                return true;
+        if (left.type > right.type)
+                return false;
+        switch (left.type) {
+        case USRQUOTA:
+                return uid_lt(left.uid, right.uid);
+        case GRPQUOTA:
+                return gid_lt(left.gid, right.gid);
+        case PRJQUOTA:
+                return projid_lt(left.projid, right.projid);
+        default:
+                BUG();
+        }
+}
+EXPORT_SYMBOL(qid_lt);
+
+/**
+ *      from_kqid - Create a qid from a kqid user-namespace pair.
+ *      @targ: The user namespace we want a qid in.
+ *      @kuid: The kernel internal quota identifier to start with.
+ *
+ *      Map @kqid into the user-namespace specified by @targ and
+ *      return the resulting qid.
+ *
+ *      There is always a mapping into the initial user_namespace.
+ *
+ *      If @kqid has no mapping in @targ (qid_t)-1 is returned.
+ */
+qid_t from_kqid(struct user_namespace *targ, struct kqid kqid)
+{
+        switch (kqid.type) {
+        case USRQUOTA:
+                return from_kuid(targ, kqid.uid);
+        case GRPQUOTA:
+                return from_kgid(targ, kqid.gid);
+        case PRJQUOTA:
+                return from_kprojid(targ, kqid.projid);
+        default:
+                BUG();
+        }
+}
+EXPORT_SYMBOL(from_kqid);
+
+/**
+ *      from_kqid_munged - Create a qid from a kqid user-namespace pair.
+ *      @targ: The user namespace we want a qid in.
+ *      @kqid: The kernel internal quota identifier to start with.
+ *
+ *      Map @kqid into the user-namespace specified by @targ and
+ *      return the resulting qid.
+ *
+ *      There is always a mapping into the initial user_namespace.
+ *
+ *      Unlike from_kqid from_kqid_munged never fails and always
+ *      returns a valid projid.  This makes from_kqid_munged
+ *      appropriate for use in places where failing to provide
+ *      a qid_t is not a good option.
+ *
+ *      If @kqid has no mapping in @targ the kqid.type specific
+ *      overflow identifier is returned.
+ */
+qid_t from_kqid_munged(struct user_namespace *targ, struct kqid kqid)
+{
+        switch (kqid.type) {
+        case USRQUOTA:
+                return from_kuid_munged(targ, kqid.uid);
+        case GRPQUOTA:
+                return from_kgid_munged(targ, kqid.gid);
+        case PRJQUOTA:
+                return from_kprojid_munged(targ, kqid.projid);
+        default:
+                BUG();
+        }
+}
+EXPORT_SYMBOL(from_kqid_munged);
+
+/**
+ *      qid_valid - Report if a valid value is stored in a kqid.
+ *      @qid: The kernel internal quota identifier to test.
+ */
+bool qid_valid(struct kqid qid)
+{
+        switch (qid.type) {
+        case USRQUOTA:
+                return uid_valid(qid.uid);
+        case GRPQUOTA:
+                return gid_valid(qid.gid);
+        case PRJQUOTA:
+                return projid_valid(qid.projid);
+        default:
+                BUG();
+        }
+}
+EXPORT_SYMBOL(qid_valid);