autofs4: Fix wait validation
It is possible for the check in wait.c:validate_request() to return
an incorrect result if the dentry that was mounted upon has changed
during the callback.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index c5f8459..5601005 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -309,6 +309,9 @@
* completed while we waited on the mutex ...
*/
if (notify == NFY_MOUNT) {
+ struct dentry *new = NULL;
+ int valid = 1;
+
/*
* If the dentry was successfully mounted while we slept
* on the wait queue mutex we can return success. If it
@@ -316,8 +319,20 @@
* a multi-mount with no mount at it's base) we can
* continue on and create a new request.
*/
+ if (!IS_ROOT(dentry)) {
+ if (dentry->d_inode && d_unhashed(dentry)) {
+ struct dentry *parent = dentry->d_parent;
+ new = d_lookup(parent, &dentry->d_name);
+ if (new)
+ dentry = new;
+ }
+ }
if (have_submounts(dentry))
- return 0;
+ valid = 0;
+
+ if (new)
+ dput(new);
+ return valid;
}
return 1;