From patchwork Fri May 26 08:56:11 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 9750139 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 18FFB60249 for ; Fri, 26 May 2017 08:56:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0998328236 for ; Fri, 26 May 2017 08:56:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F28F728332; Fri, 26 May 2017 08:56:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 74CF328236 for ; Fri, 26 May 2017 08:56:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033100AbdEZI4q (ORCPT ); Fri, 26 May 2017 04:56:46 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:33814 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030990AbdEZI4n (ORCPT ); Fri, 26 May 2017 04:56:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=7whSW15ykPGx4SJpNtIE+9mHBN8SNotxAjqbKUloO5E=; b=e4Y2/WugsrNUURHvxA8LolJy9 duMf4hM357Rv0IDrRUA32k9mfksdfrkYsDDq8uR94ShxkczoWaGAIu5kpTn9Hr8zvwv+0wCuz8EY5 2wTKZpss0uE32i95M5y7upeARVfszplhgCe+521P7+6a1N+Pi0/prywAoM4xnzEmJIsVzSeMhe8CW lxp8T62BsCbU6oZPA549lFKfBWChZmpaBXUKnQ2Vkn6u81ZXqcilNCMTFHeZH22C+ZLgfMZOF8LIL WV7KbM6BP0XqPrjJ+ELwqf1PiufosRR+zKQoKRLOolEXcF6i7xDiTPV9PaQen5jIjCt+dskpKRlc8 YrmmJwZHw==; Received: from shol69.static.otenet.gr ([83.235.170.67] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.87 #1 (Red Hat Linux)) id 1dEB33-0004R3-Nq; Fri, 26 May 2017 08:56:42 +0000 From: Christoph Hellwig To: axboe@kernel.dk Cc: linux-block@vger.kernel.org, dm-devel@redhat.com, linux-btrfs@vger.kernel.org Subject: [PATCH 04/13] dm: fix REQ_RAHEAD handling Date: Fri, 26 May 2017 11:56:11 +0300 Message-Id: <20170526085620.3113-5-hch@lst.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170526085620.3113-1-hch@lst.de> References: <20170526085620.3113-1-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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. Signed-off-by: Christoph Hellwig Reviewed-by: Bart Van Assche --- drivers/md/dm-raid1.c | 4 ++-- drivers/md/dm-stripe.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index a95cbb80fb34..5e30b08b91d9 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -1214,7 +1214,7 @@ static int mirror_map(struct dm_target *ti, struct bio *bio) */ if (!r || (r == -EWOULDBLOCK)) { if (bio->bi_opf & REQ_RAHEAD) - return -EWOULDBLOCK; + return -EIO; queue_bio(ms, bio, rw); return DM_MAPIO_SUBMITTED; @@ -1258,7 +1258,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error) if (error == -EOPNOTSUPP) return error; - if ((error == -EWOULDBLOCK) && (bio->bi_opf & REQ_RAHEAD)) + if (bio->bi_opf & REQ_RAHEAD) return error; if (unlikely(error)) { diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c index 75152482f3ad..780e95889a7c 100644 --- a/drivers/md/dm-stripe.c +++ b/drivers/md/dm-stripe.c @@ -384,7 +384,7 @@ static int stripe_end_io(struct dm_target *ti, struct bio *bio, int error) if (!error) return 0; /* I/O complete */ - if ((error == -EWOULDBLOCK) && (bio->bi_opf & REQ_RAHEAD)) + if (bio->bi_opf & REQ_RAHEAD) return error; if (error == -EOPNOTSUPP)