NFS: Properly handle the case where the delegation is revoked

If we know that the delegation stateid is bad or revoked, we need to
remove that delegation as soon as possible, and then mark all the
stateids that relied on that delegation for recovery. We cannot use
the delegation as part of the recovery process.

Also note that NFSv4.1 uses a different error code (NFS4ERR_DELEG_REVOKED)
to indicate that the delegation was revoked.

Finally, ensure that setlk() and setattr() can both recover safely from
a revoked delegation.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

1 files changed, 11 insertions, 0 deletions

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 7f2654069806..ac889af8ccf5 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -466,6 +466,17 @@ static void nfs_delegation_run_state_manager(struct nfs_client *clp)
                 nfs4_schedule_state_manager(clp);
 }
 
+void nfs_remove_bad_delegation(struct inode *inode)
+{
+        struct nfs_delegation *delegation;
+
+        delegation = nfs_detach_delegation(NFS_I(inode), NFS_SERVER(inode));
+        if (delegation) {
+                nfs_inode_find_state_and_recover(inode, &delegation->stateid);
+                nfs_free_delegation(delegation);
+        }
+}
+
 /**
  * nfs_expire_all_delegation_types
  * @clp: client to process