Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f170.google.com ([209.85.223.170]:60117 "EHLO mail-ie0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751915AbaFEREn (ORCPT ); Thu, 5 Jun 2014 13:04:43 -0400 Received: by mail-ie0-f170.google.com with SMTP id to1so1168766ieb.15 for ; Thu, 05 Jun 2014 10:04:41 -0700 (PDT) From: Trond Myklebust To: linux-nfs@vger.kernel.org Subject: [PATCH] NFS: Use raw_write_seqcount_begin/end int nfs4_reclaim_open_state Date: Thu, 5 Jun 2014 13:04:39 -0400 Message-Id: <1401987879-2927-1-git-send-email-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: The addition of lockdep code to write_seqcount_begin/end has lead to a bunch of false positive claims of ABBA deadlocks with the so_lock spinlock. Audits show that this simply cannot happen because the read side code does not spin while holding so_lock. Cc: # 3.13.x Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 2349518eef2c..21275148fc13 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -1456,7 +1456,7 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs * server that doesn't support a grace period. */ spin_lock(&sp->so_lock); - write_seqcount_begin(&sp->so_reclaim_seqcount); + raw_write_seqcount_begin(&sp->so_reclaim_seqcount); restart: list_for_each_entry(state, &sp->so_states, open_states) { if (!test_and_clear_bit(ops->state_flag_bit, &state->flags)) @@ -1519,13 +1519,13 @@ restart: spin_lock(&sp->so_lock); goto restart; } - write_seqcount_end(&sp->so_reclaim_seqcount); + raw_write_seqcount_end(&sp->so_reclaim_seqcount); spin_unlock(&sp->so_lock); return 0; out_err: nfs4_put_open_state(state); spin_lock(&sp->so_lock); - write_seqcount_end(&sp->so_reclaim_seqcount); + raw_write_seqcount_end(&sp->so_reclaim_seqcount); spin_unlock(&sp->so_lock); return status; } -- 1.9.3