From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D240CC433E0 for ; Mon, 29 Jun 2020 20:14:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5F3F20760 for ; Mon, 29 Jun 2020 20:14:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593461678; bh=yaxxQRVddgLLU1mEzBS9LCPeKyakKlY+qyYxcS2VEjs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=v2ECFyPeChl8JeN+PPUkqs4TO2CiYpBmXDKGozekauTFTuax7M5jYuIpqJfEMYNwZ bDAoGU9Q+GX/ITS7wKyYfD1FMnvc3R7AQoBjlWx1YpN2g249N07nA96kNHr8SI9EP5 xUlEuKy1WUaNBvA6V+AIkmzUTE7GP3b4ePskvaKg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732686AbgF2UOe (ORCPT ); Mon, 29 Jun 2020 16:14:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:40566 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732837AbgF2TaS (ORCPT ); Mon, 29 Jun 2020 15:30:18 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CD2AF252A2; Mon, 29 Jun 2020 15:36:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593445011; bh=yaxxQRVddgLLU1mEzBS9LCPeKyakKlY+qyYxcS2VEjs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UgVdsMkUWFgR7Y6fCFsoYAcAF5yiyUKg//o7/N1MHWlf3VTGWQXFyesvQzlWiw3XE phzqjn4umUbBgp+/5U+7TIObqpe9IxdctWd6hs6on4ACDOAjb18Uh2OeSIb2HFFMPC pjg6kVG/pnX9oJ/lAG0OzWg0wIH2nPLUlgepFGzQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Filipe Manana , David Sterba , Greg Kroah-Hartman Subject: [PATCH 4.19 112/131] btrfs: fix failure of RWF_NOWAIT write into prealloc extent beyond eof Date: Mon, 29 Jun 2020 11:34:43 -0400 Message-Id: <20200629153502.2494656-113-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629153502.2494656-1-sashal@kernel.org> References: <20200629153502.2494656-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.19.131-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.19.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.19.131-rc1 X-KernelTest-Deadline: 2020-07-01T15:34+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Filipe Manana commit 4b1946284dd6641afdb9457101056d9e6ee6204c upstream. If we attempt to write to prealloc extent located after eof using a RWF_NOWAIT write, we always fail with -EAGAIN. We do actually check if we have an allocated extent for the write at the start of btrfs_file_write_iter() through a call to check_can_nocow(), but later when we go into the actual direct IO write path we simply return -EAGAIN if the write starts at or beyond EOF. Trivial to reproduce: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ touch /mnt/foo $ chattr +C /mnt/foo $ xfs_io -d -c "pwrite -S 0xab 0 64K" /mnt/foo wrote 65536/65536 bytes at offset 0 64 KiB, 16 ops; 0.0004 sec (135.575 MiB/sec and 34707.1584 ops/sec) $ xfs_io -c "falloc -k 64K 1M" /mnt/foo $ xfs_io -d -c "pwrite -N -V 1 -S 0xfe -b 64K 64K 64K" /mnt/foo pwrite: Resource temporarily unavailable On xfs and ext4 the write succeeds, as expected. Fix this by removing the wrong check at btrfs_direct_IO(). Fixes: edf064e7c6fec3 ("btrfs: nowait aio support") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/inode.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 7ffb15b473a72..8dd2702ce859e 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8656,9 +8656,6 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) dio_data.overwrite = 1; inode_unlock(inode); relock = true; - } else if (iocb->ki_flags & IOCB_NOWAIT) { - ret = -EAGAIN; - goto out; } ret = btrfs_delalloc_reserve_space(inode, &data_reserved, offset, count); -- 2.25.1