Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx12.netapp.com ([216.240.18.77]:58418 "EHLO mx12.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751516Ab3JURKX (ORCPT ); Mon, 21 Oct 2013 13:10:23 -0400 From: Weston Andros Adamson To: CC: , Weston Andros Adamson Subject: [PATCH 5/5] NFSv4: clean up nfs4_state reference counting Date: Mon, 21 Oct 2013 13:10:14 -0400 Message-ID: <1382375414-5854-6-git-send-email-dros@netapp.com> In-Reply-To: <1382375414-5854-1-git-send-email-dros@netapp.com> References: <1382375414-5854-1-git-send-email-dros@netapp.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-nfs-owner@vger.kernel.org List-ID: Use atomic_inc_not_zero() to avoid referencing a state that is currently being freed. Signed-off-by: Weston Andros Adamson --- fs/nfs/nfs4proc.c | 8 ++++++-- fs/nfs/nfs4state.c | 3 ++- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index a3b78df..005543d 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -1275,7 +1275,8 @@ static struct nfs4_state *nfs4_try_open_cached(struct nfs4_opendata *opendata) out: return ERR_PTR(ret); out_return_state: - atomic_inc(&state->count); + if (!atomic_inc_not_zero(&state->count)) + return ERR_PTR(-EINVAL); return state; } @@ -1429,7 +1430,10 @@ static struct nfs4_opendata *nfs4_open_recoverdata_alloc(struct nfs_open_context if (opendata == NULL) return ERR_PTR(-ENOMEM); opendata->state = state; - atomic_inc(&state->count); + if (!atomic_inc_not_zero(&state->count)) { + nfs4_opendata_put(opendata); + return ERR_PTR(-EINVAL); + } return opendata; } diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index cc14cbb..1c71907 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -1416,7 +1416,8 @@ restart: continue; if (state->state == 0) continue; - atomic_inc(&state->count); + if (!atomic_inc_not_zero(&state->count)) + continue; spin_unlock(&sp->so_lock); status = ops->recover_open(sp, state); if (status >= 0) { -- 1.7.12.4 (Apple Git-37)