Commit 340f0ba1 authored Mar 23, 2015 by J. Bruce Fields

nfsd: return correct lockowner when there is a race on hash insert



alloc_init_lock_stateowner can return an already freed entry if there is
a race to put openowners in the hashtable.

Noticed by inspection after Jeff Layton fixed the same bug for open
owners.  Depending on client behavior, this one may be trickier to
trigger in practice.

Fixes: c58c6610 "nfsd: Protect adding/removing lock owners using client_lock"
Cc: <stable@vger.kernel.org>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Acked-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

parent c5952338

fs/nfsd/nfs4state.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -5062,7 +5062,7 @@ alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp,
	} else		} else
	nfs4_free_lockowner(&lo->lo_owner);		nfs4_free_lockowner(&lo->lo_owner);
	spin_unlock(&clp->cl_lock);		spin_unlock(&clp->cl_lock);
	return lo;		return ret;
	}		}

	static void		static void