From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1950428AbcHRONP (ORCPT ); Thu, 18 Aug 2016 10:13:15 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:37029 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1950415AbcHRONL (ORCPT ); Thu, 18 Aug 2016 10:13:11 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust , Jeff Layton Subject: [PATCH 4.7 095/186] pNFS: Fix post-layoutget error handling in pnfs_update_layout() Date: Thu, 18 Aug 2016 15:58:32 +0200 Message-Id: <20160818135936.203780307@linuxfoundation.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20160818135932.219369981@linuxfoundation.org> References: <20160818135932.219369981@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Trond Myklebust commit 56b38a1f7c781519eef09c1668a3c97ea911f86b upstream. The non-retry error path is currently broken and ends up releasing the reference to the layout twice. It also can end up clearing the NFS_LAYOUT_FIRST_LAYOUTGET flag twice, causing a race. In addition, the retry path will fail to decrement the plh_outstanding counter. Fixes: 183d9e7b112aa ("pnfs: rework LAYOUTGET retry handling") Signed-off-by: Trond Myklebust Reviewed-by: Jeff Layton Signed-off-by: Greg Kroah-Hartman --- fs/nfs/pnfs.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -1645,6 +1645,7 @@ lookup_again: lseg = send_layoutget(lo, ctx, &stateid, &arg, &timeout, gfp_flags); trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET); + atomic_dec(&lo->plh_outstanding); if (IS_ERR(lseg)) { switch(PTR_ERR(lseg)) { case -EBUSY: @@ -1653,26 +1654,26 @@ lookup_again: lseg = NULL; /* Fallthrough */ case -EAGAIN: - pnfs_put_layout_hdr(lo); - if (first) - pnfs_clear_first_layoutget(lo); - if (lseg) { - trace_pnfs_update_layout(ino, pos, count, - iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY); - goto lookup_again; - } - /* Fallthrough */ + break; default: if (!nfs_error_is_fatal(PTR_ERR(lseg))) { pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode)); lseg = NULL; } + goto out_put_layout_hdr; + } + if (lseg) { + if (first) + pnfs_clear_first_layoutget(lo); + trace_pnfs_update_layout(ino, pos, count, + iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY); + pnfs_put_layout_hdr(lo); + goto lookup_again; } } else { pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode)); } - atomic_dec(&lo->plh_outstanding); out_put_layout_hdr: if (first) pnfs_clear_first_layoutget(lo);