From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa2.hgst.iphmx.com ([68.232.143.124]:59263 "EHLO esa2.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933207AbdEXQHq (ORCPT ); Wed, 24 May 2017 12:07:46 -0400 From: Bart Van Assche To: "hch@lst.de" , "axboe@kernel.dk" CC: "dm-devel@redhat.com" , "linux-btrfs@vger.kernel.org" , "linux-block@vger.kernel.org" Subject: Re: [PATCH 04/15] dm: fix REQ_RAHEAD handling Date: Wed, 24 May 2017 16:07:32 +0000 Message-ID: <1495642051.2823.9.camel@sandisk.com> References: <20170518131812.22956-1-hch@lst.de> <20170518131812.22956-5-hch@lst.de> In-Reply-To: <20170518131812.22956-5-hch@lst.de> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, 2017-05-18 at 15:18 +0200, Christoph Hellwig wrote: > A few (but not all) dm targets use a special EWOULDBLOCK error code for > failing REQ_RAHEAD requests that fail due to a lack of available resources. > But no one else knows about this magic code, and lower level drivers also > don't generate it when failing read-ahead requests for similar reasons. > > So remove this special casing and ignore all additional error handling for > REQ_RAHEAD - if this was a real underlying error we'd get a normal read > once the real read comes in. Reviewed-by: Bart Van Assche