From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752279AbdGOBlm (ORCPT ); Fri, 14 Jul 2017 21:41:42 -0400 Received: from omzsmtpe01.verizonbusiness.com ([199.249.25.210]:53795 "EHLO omzsmtpe01.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751391AbdGOB1N (ORCPT ); Fri, 14 Jul 2017 21:27:13 -0400 X-IronPort-Anti-Spam-Filtered: false From: "Levin, Alexander (Sasha Levin)" Cc: Liu Bo , David Sterba , "Levin, Alexander (Sasha Levin)" X-Host: discovery.odc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH for v4.9 LTS 37/87] Btrfs: adjust outstanding_extents counter properly when dio write is split Thread-Topic: [PATCH for v4.9 LTS 37/87] Btrfs: adjust outstanding_extents counter properly when dio write is split Thread-Index: AQHS/QlWPd1GHYkowUadECxavumAtw== Date: Sat, 15 Jul 2017 01:26:09 +0000 Message-ID: <20170715012538.10101-37-alexander.levin@verizon.com> References: <20170715012538.10101-1-alexander.levin@verizon.com> In-Reply-To: <20170715012538.10101-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v6F1flmX023332 From: Liu Bo [ Upstream commit c2931667c83ded6504b3857e99cc45b21fa496fb ] Currently how btrfs dio deals with split dio write is not good enough if dio write is split into several segments due to the lack of contiguous space, a large dio write like 'dd bs=1G count=1' can end up with incorrect outstanding_extents counter and endio would complain loudly with an assertion. This fixes the problem by compensating the outstanding_extents counter in inode if a large dio write gets split. Reported-by: Anand Jain Tested-by: Anand Jain Signed-off-by: Liu Bo Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/inode.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a2a014b19f18..8a05fa7e2152 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7648,11 +7648,18 @@ static void adjust_dio_outstanding_extents(struct inode *inode, * within our reservation, otherwise we need to adjust our inode * counter appropriately. */ - if (dio_data->outstanding_extents) { + if (dio_data->outstanding_extents >= num_extents) { dio_data->outstanding_extents -= num_extents; } else { + /* + * If dio write length has been split due to no large enough + * contiguous space, we need to compensate our inode counter + * appropriately. + */ + u64 num_needed = num_extents - dio_data->outstanding_extents; + spin_lock(&BTRFS_I(inode)->lock); - BTRFS_I(inode)->outstanding_extents += num_extents; + BTRFS_I(inode)->outstanding_extents += num_needed; spin_unlock(&BTRFS_I(inode)->lock); } } -- 2.11.0