NFSv4: Fix a race in nfs_inode_reclaim_delegation()
If we race with a delegreturn before taking the spin lock, we
currently end up dropping the delegation stateid.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 5de4cfb..094e0ef 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -195,15 +195,13 @@
rcu_read_unlock();
put_rpccred(oldcred);
trace_nfs4_reclaim_delegation(inode, res->delegation_type);
- } else {
- /* We appear to have raced with a delegation return. */
- spin_unlock(&delegation->lock);
- rcu_read_unlock();
- nfs_inode_set_delegation(inode, cred, res);
+ return;
}
- } else {
- rcu_read_unlock();
+ /* We appear to have raced with a delegation return. */
+ spin_unlock(&delegation->lock);
}
+ rcu_read_unlock();
+ nfs_inode_set_delegation(inode, cred, res);
}
static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)