move exec_permission() up to the rest of permission-related functions

... and convert the comment before it into linuxdoc form.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index 4ad2b78..e04f15a 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -303,6 +303,44 @@ int inode_permission(struct inode *inode, int mask)
        return security_inode_permission(inode, mask);
 }
 
+/**
+ * exec_permission  -  check for right to do lookups in a given directory
+ * @inode:     inode to check permission on
+ * @flags:     IPERM_FLAG_ flags.
+ *
+ * Short-cut version of inode_permission(), for calling on directories
+ * during pathname resolution.  Combines parts of inode_permission()
+ * and generic_permission(), and tests ONLY for MAY_EXEC permission.
+ *
+ * If appropriate, check DAC only.  If not appropriate, or
+ * short-cut DAC fails, then call ->permission() to do more
+ * complete permission check.
+ */
+static inline int exec_permission(struct inode *inode, unsigned int flags)
+{
+       int ret;
+       struct user_namespace *ns = inode_userns(inode);
+
+       if (inode->i_op->permission) {
+               ret = inode->i_op->permission(inode, MAY_EXEC, flags);
+               if (likely(!ret))
+                       goto ok;
+       } else {
+               ret = acl_permission_check(inode, MAY_EXEC, flags,
+                               inode->i_op->check_acl);
+               if (likely(!ret))
+                       goto ok;
+               if (ret != -EACCES)
+                       return ret;
+               if (ns_capable(ns, CAP_DAC_OVERRIDE) ||
+                               ns_capable(ns, CAP_DAC_READ_SEARCH))
+                       goto ok;
+       }
+       return ret;
+ok:
+       return security_inode_exec_permission(inode, flags);
+}
+
 /*
  * get_write_access() gets write permission for a file.
  * put_write_access() releases this write permission.
@@ -551,40 +589,6 @@ static int complete_walk(struct nameidata *nd)
        return status;
 }
 
-/*
- * Short-cut version of permission(), for calling on directories
- * during pathname resolution.  Combines parts of permission()
- * and generic_permission(), and tests ONLY for MAY_EXEC permission.
- *
- * If appropriate, check DAC only.  If not appropriate, or
- * short-cut DAC fails, then call ->permission() to do more
- * complete permission check.
- */
-static inline int exec_permission(struct inode *inode, unsigned int flags)
-{
-       int ret;
-       struct user_namespace *ns = inode_userns(inode);
-
-       if (inode->i_op->permission) {
-               ret = inode->i_op->permission(inode, MAY_EXEC, flags);
-               if (likely(!ret))
-                       goto ok;
-       } else {
-               ret = acl_permission_check(inode, MAY_EXEC, flags,
-                               inode->i_op->check_acl);
-               if (likely(!ret))
-                       goto ok;
-               if (ret != -EACCES)
-                       return ret;
-               if (ns_capable(ns, CAP_DAC_OVERRIDE) ||
-                               ns_capable(ns, CAP_DAC_READ_SEARCH))
-                       goto ok;
-       }
-       return ret;
-ok:
-       return security_inode_exec_permission(inode, flags);
-}
-
 static __always_inline void set_root(struct nameidata *nd)
 {
        if (!nd->root.mnt)