NFSv4: Fix an infinite loop in the NFS state recovery code

Marten Gajda <marten.gajda@fernuni-hagen.de> states:

I tracked the problem down to the function nfs4_do_open_expired.
Within this function _nfs4_open_expired is called and may return
-NFS4ERR_DELAY. When a further call to _nfs4_open_expired is
executed and does not return -NFS4ERR_DELAY the "exception.retry"
variable is not reset to 0, causing the loop to iterate again
(and as long as err != -NFS4ERR_DELAY, probably forever)

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index e8df52d..49eebe2 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1104,8 +1104,9 @@ static inline int nfs4_do_open_expired(struct nfs_open_context *ctx, struct nfs4
 
        do {
                err = _nfs4_open_expired(ctx, state);
-               if (err == -NFS4ERR_DELAY)
-                       nfs4_handle_exception(server, err, &exception);
+               if (err != -NFS4ERR_DELAY)
+                       break;
+               nfs4_handle_exception(server, err, &exception);
        } while (exception.retry);
        return err;
 }