From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D53141DE3D9 for ; Fri, 6 Dec 2024 12:06:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733486781; cv=none; b=oUvfUkTPKWplesSnIm1DxtRE8vb5tXQRMyVobuOrdi9d9ucCzagyU8w16w9iZ/NZMQB/VYxljVMuRSFRu2S3on0RZk297urLTYw8W4tKtNwdQdzViVIvYDtuDpP7DgaXsfXeRfiW1A5pUB1NPpxghCIN3/WVwNrtfuSrq1XZfHU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733486781; c=relaxed/simple; bh=24aNjU3O3gbeM49RR/afGrOx5L0yM0VO74bePYIBP2w=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=Hqs29Gtplw85amufyCow3XfOsCsfdfA0Wbu0onRmOLLq6awytVz/l0G8/ZPy9UYW7g+gtCdB1s9ongAjZIhrvgKGjPeYqdM5dFyT9ywMNXvYaS4cEppU/iKsZ8vdN3wEb3v24Yu1ZfhvE00igzZXsf8bVozoE1rBpy6gZPLmg2g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=RnGNRVMa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="RnGNRVMa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E21A9C4CED1; Fri, 6 Dec 2024 12:06:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733486779; bh=24aNjU3O3gbeM49RR/afGrOx5L0yM0VO74bePYIBP2w=; h=Subject:To:Cc:From:Date:From; b=RnGNRVMazSUziHMr+6aiLiN9mfreVnnYT0MmZk6UhCZx49CW0XZ8nok9mctu/Yxh/ AdTyYHpax3bbm6pJhfMiXoo3aKGtU4IRdMlNJhfaXFpcYielwduT1kbXyXVqf1nshH c+trJoYHakuYd3Dih+sNANZVC2WqI7lxC/wKnU5M= Subject: FAILED: patch "[PATCH] f2fs: fix to drop all discards after creating snapshot on lvm" failed to apply to 6.1-stable tree To: chao@kernel.org,jaegeuk@kernel.org,piergiorgio.sartor@nexgo.de Cc: From: Date: Fri, 06 Dec 2024 13:06:13 +0100 Message-ID: <2024120613-dating-jawless-e589@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x bc8aeb04fd80cb8cfae3058445c84410fd0beb5e # git commit -s git send-email --to '' --in-reply-to '2024120613-dating-jawless-e589@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From bc8aeb04fd80cb8cfae3058445c84410fd0beb5e Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Thu, 21 Nov 2024 22:17:16 +0800 Subject: [PATCH] f2fs: fix to drop all discards after creating snapshot on lvm device Piergiorgio reported a bug in bugzilla as below: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 969 at fs/f2fs/segment.c:1330 RIP: 0010:__submit_discard_cmd+0x27d/0x400 [f2fs] Call Trace: __issue_discard_cmd+0x1ca/0x350 [f2fs] issue_discard_thread+0x191/0x480 [f2fs] kthread+0xcf/0x100 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1a/0x30 w/ below testcase, it can reproduce this bug quickly: - pvcreate /dev/vdb - vgcreate myvg1 /dev/vdb - lvcreate -L 1024m -n mylv1 myvg1 - mount /dev/myvg1/mylv1 /mnt/f2fs - dd if=/dev/zero of=/mnt/f2fs/file bs=1M count=20 - sync - rm /mnt/f2fs/file - sync - lvcreate -L 1024m -s -n mylv1-snapshot /dev/myvg1/mylv1 - umount /mnt/f2fs The root cause is: it will update discard_max_bytes of mounted lvm device to zero after creating snapshot on this lvm device, then, __submit_discard_cmd() will pass parameter @nr_sects w/ zero value to __blkdev_issue_discard(), it returns a NULL bio pointer, result in panic. This patch changes as below for fixing: 1. Let's drop all remained discards in f2fs_unfreeze() if snapshot of lvm device is created. 2. Checking discard_max_bytes before submitting discard during __submit_discard_cmd(). Cc: stable@vger.kernel.org Fixes: 35ec7d574884 ("f2fs: split discard command in prior to block layer") Reported-by: Piergiorgio Sartor Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219484 Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 4236040e3994..eade36c5ef13 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -1290,16 +1290,18 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi, wait_list, issued); return 0; } - - /* - * Issue discard for conventional zones only if the device - * supports discard. - */ - if (!bdev_max_discard_sectors(bdev)) - return -EOPNOTSUPP; } #endif + /* + * stop issuing discard for any of below cases: + * 1. device is conventional zone, but it doesn't support discard. + * 2. device is regulare device, after snapshot it doesn't support + * discard. + */ + if (!bdev_max_discard_sectors(bdev)) + return -EOPNOTSUPP; + trace_f2fs_issue_discard(bdev, dc->di.start, dc->di.len); lstart = dc->di.lstart; diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index c0670cd61956..fc7d463dee15 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1760,6 +1760,18 @@ static int f2fs_freeze(struct super_block *sb) static int f2fs_unfreeze(struct super_block *sb) { + struct f2fs_sb_info *sbi = F2FS_SB(sb); + + /* + * It will update discard_max_bytes of mounted lvm device to zero + * after creating snapshot on this lvm device, let's drop all + * remained discards. + * We don't need to disable real-time discard because discard_max_bytes + * will recover after removal of snapshot. + */ + if (test_opt(sbi, DISCARD) && !f2fs_hw_support_discard(sbi)) + f2fs_issue_discard_timeout(sbi); + clear_sbi_flag(F2FS_SB(sb), SBI_IS_FREEZING); return 0; }