From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:46423 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754764AbcBPMT6 (ORCPT ); Tue, 16 Feb 2016 07:19:58 -0500 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id BAFFB2025A for ; Tue, 16 Feb 2016 12:19:57 +0000 (UTC) Received: from debian3.lan (bl8-199-62.dsl.telepac.pt [85.241.199.62]) (using TLSv1.2 with cipher AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A0C582025B for ; Tue, 16 Feb 2016 12:19:56 +0000 (UTC) From: fdmanana@kernel.org To: linux-btrfs@vger.kernel.org Subject: [PATCH v2] Btrfs: fix direct IO requests not reporting IO error to user space Date: Tue, 16 Feb 2016 04:01:44 +0000 Message-Id: <1455595304-29320-1-git-send-email-fdmanana@kernel.org> In-Reply-To: <1455554316-1167-1-git-send-email-fdmanana@kernel.org> References: <1455554316-1167-1-git-send-email-fdmanana@kernel.org> Sender: linux-btrfs-owner@vger.kernel.org List-ID: From: Filipe Manana If a bio for a direct IO request fails, we were not setting the error in the parent bio (the main DIO bio), making us not return the error to user space in btrfs_direct_IO(), that is, it made __blockdev_direct_IO() return the number of bytes issued for IO and not the error a bio created and submitted by btrfs_submit_direct() got from the block layer. This essentially happens because when we call: dio_end_io(dio_bio, bio->bi_error); It does not set dio_bio->bi_error to the value of the second argument. So just add this missing assignment in endio callbacks, just as we do in the error path at btrfs_submit_direct() when we fail to clone the dio bio or allocate its private object. This follows the convention of what is done with other similar APIs such as bio_endio() where the caller is responsible for setting the bi_error field in the bio it passes as an argument to bio_endio(). This was detected by the new generic test cases in xfstests: 271, 272, 276 and 278. Which essentially setup a dm error target, then load the error table, do a direct IO write and unload the error table. They expect the write to fail with -EIO, which was not getting reported when testing against btrfs. Cc: stable@vger.kernel.org # 4.3+ Fixes: 4246a0b63bd8 ("block: add a bi_error field to struct bio") Signed-off-by: Filipe Manana --- V2: Updated commit message to reflect affected kernel versions. fs/btrfs/inode.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 600bf0d..e0ad8b2 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7985,6 +7985,7 @@ static void btrfs_endio_direct_read(struct bio *bio) kfree(dip); + dio_bio->bi_error = bio->bi_error; dio_end_io(dio_bio, bio->bi_error); if (io_bio->end_io) @@ -8039,6 +8040,7 @@ static void btrfs_endio_direct_write(struct bio *bio) kfree(dip); + dio_bio->bi_error = bio->bi_error; dio_end_io(dio_bio, bio->bi_error); bio_put(bio); } -- 2.7.0.rc3