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-rw-r--r--fs/quota/kqid.c132
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);