nfsd4: warn on finding lockowner without stateid's

The current code assumes a one-to-one lockowner<->lock stateid
correspondance.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 89e42409b23749e5be540ffe34a7f46392b0bbc4..9a77a5a21557c4e16740196c16d7f4f218ce2643 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4166,6 +4166,10 @@ static bool same_lockowner_ino(struct nfs4_lockowner *lo, struct inode *inode, c
 
        if (!same_owner_str(&lo->lo_owner, owner, clid))
                return false;
+       if (list_empty(&lo->lo_owner.so_stateids)) {
+               WARN_ON_ONCE(1);
+               return false;
+       }
        lst = list_first_entry(&lo->lo_owner.so_stateids,
                               struct nfs4_ol_stateid, st_perstateowner);
        return lst->st_file->fi_inode == inode;