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 9BD691836CB; Wed, 3 Jul 2024 10:45:47 +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=1720003547; cv=none; b=ag2Ly6tpclI8rJW9jIvUb2XLtwASy66/PVu1wSJXwFh8R9EGEHl9yto8hR5xznD8Jxya4QS69twRIyvYZECtUnaaNZd/+TSoZUVeoV3mU3Hbi321eMD0wGCioovFaT+ACyzpFCpvx2DQ9Sntj3X5lZ3Uw+iTNw/8Z1ZXqla6qkE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720003547; c=relaxed/simple; bh=imGZ1Na2M5Sz6Yj3PmR7AfHftcz/TiVL3Byg2KWbes4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CWPlLB7o3dJnihd3qKvrOBc7eHEHoQz404X0Ss0rYirHy3ak8LLbXqO8y5QBh5lj0p5miJS1BbvCnF0zxqzN452uRVB5o2DI0oTqpa4EsMlJDCa5LH2oDSo/pb0H7lXjg0MZTAAeTovU+WRAGJQ46z1tBBtNYW7liOeOjq3S4Kg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=i/QDtNzs; 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="i/QDtNzs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 150F9C2BD10; Wed, 3 Jul 2024 10:45:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720003547; bh=imGZ1Na2M5Sz6Yj3PmR7AfHftcz/TiVL3Byg2KWbes4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i/QDtNzsWsK29aCzoZ+NyMCk7VF9fTMtsZYdDuWCst0BsvY+m4QhP1Y3VxFYTvtDY 0TeL9KDjUTOz01LU+xD7oUUwlhw3/Oz2v/CtKOWadziVw7Awc915VQ22QkqTmKwtJ2 Afd7U1ZUIwXppsITFZmVQyPVp/P/riVEXIoaopdE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryusuke Konishi , Andrew Morton Subject: [PATCH 4.19 057/139] nilfs2: fix potential kernel bug due to lack of writeback flag waiting Date: Wed, 3 Jul 2024 12:39:14 +0200 Message-ID: <20240703102832.592271743@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102830.432293640@linuxfoundation.org> References: <20240703102830.432293640@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ryusuke Konishi commit a4ca369ca221bb7e06c725792ac107f0e48e82e7 upstream. Destructive writes to a block device on which nilfs2 is mounted can cause a kernel bug in the folio/page writeback start routine or writeback end routine (__folio_start_writeback in the log below): kernel BUG at mm/page-writeback.c:3070! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI ... RIP: 0010:__folio_start_writeback+0xbaa/0x10e0 Code: 25 ff 0f 00 00 0f 84 18 01 00 00 e8 40 ca c6 ff e9 17 f6 ff ff e8 36 ca c6 ff 4c 89 f7 48 c7 c6 80 c0 12 84 e8 e7 b3 0f 00 90 <0f> 0b e8 1f ca c6 ff 4c 89 f7 48 c7 c6 a0 c6 12 84 e8 d0 b3 0f 00 ... Call Trace: nilfs_segctor_do_construct+0x4654/0x69d0 [nilfs2] nilfs_segctor_construct+0x181/0x6b0 [nilfs2] nilfs_segctor_thread+0x548/0x11c0 [nilfs2] kthread+0x2f0/0x390 ret_from_fork+0x4b/0x80 ret_from_fork_asm+0x1a/0x30 This is because when the log writer starts a writeback for segment summary blocks or a super root block that use the backing device's page cache, it does not wait for the ongoing folio/page writeback, resulting in an inconsistent writeback state. Fix this issue by waiting for ongoing writebacks when putting folios/pages on the backing device into writeback state. Link: https://lkml.kernel.org/r/20240530141556.4411-1-konishi.ryusuke@gmail.com Fixes: 9ff05123e3bf ("nilfs2: segment constructor") Signed-off-by: Ryusuke Konishi Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/nilfs2/segment.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1692,6 +1692,7 @@ static void nilfs_segctor_prepare_write( if (bh->b_page != bd_page) { if (bd_page) { lock_page(bd_page); + wait_on_page_writeback(bd_page); clear_page_dirty_for_io(bd_page); set_page_writeback(bd_page); unlock_page(bd_page); @@ -1705,6 +1706,7 @@ static void nilfs_segctor_prepare_write( if (bh == segbuf->sb_super_root) { if (bh->b_page != bd_page) { lock_page(bd_page); + wait_on_page_writeback(bd_page); clear_page_dirty_for_io(bd_page); set_page_writeback(bd_page); unlock_page(bd_page); @@ -1721,6 +1723,7 @@ static void nilfs_segctor_prepare_write( } if (bd_page) { lock_page(bd_page); + wait_on_page_writeback(bd_page); clear_page_dirty_for_io(bd_page); set_page_writeback(bd_page); unlock_page(bd_page);