From: "HUANG Weller (CM/ESW12-CN)" Subject: patch ext4: fix data exposure after a crash still work ? Date: Tue, 6 Dec 2016 09:52:01 +0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Cc: "linux-ext4@vger.kernel.org" To: Jan Kara Return-path: Received: from smtp6-v.fe.bosch.de ([139.15.237.11]:26731 "EHLO smtp6-v.fe.bosch.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751865AbcLFJwH (ORCPT ); Tue, 6 Dec 2016 04:52:07 -0500 Content-Language: en-US Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi Kara Since we move to kernel 3.18 stable branch. i found the patch " ext4: fix data exposure after a crash " not available but I found below commit which mentioned that patch. I want to check with you whether " ext4: fix data exposure after a crash " still needed currently ? I guess yes but I want to confirm with you. Thanks Huang weller ext4: fix deadlock during page writeback [ Upstream commit 646caa9c8e196880b41cd3e3d33a2ebc752bdb85 ] Commit 06bd3c36a733 (ext4: fix data exposure after a crash) uncovered a deadlock in ext4_writepages() which was previously much harder to hit. After this commit xfstest generic/130 reproduces the deadlock on small filesystems. The problem happens when ext4_do_update_inode() sets LARGE_FILE feature and marks current inode handle as synchronous. That subsequently results in ext4_journal_stop() called from ext4_writepages() to block waiting for transaction commit while still holding page locks, reference to io_end, and some prepared bio in mpd structure each of which can possibly block transaction commit from completing and thus results in deadlock. Fix the problem by releasing page locks, io_end reference, and submitting prepared bio before calling ext4_journal_stop(). [ Changed to defer the call to ext4_journal_stop() only if the handle is synchronous. --tytso ] Best regards Weller HUANG Base SW (CM/ESW12-CN) Bosch Automotive Products (Suzhou) Co. Ltd | No. 126, Su Hong Xi Road Suzhou Industrial Park | Suzhou P.R.China | P.R.CHINA Tel. +86(512)6767-4518 | Weller.Huang@cn.bosch.com Sitz: Suzhou, Registergericht: State Administration of Industry & Commerce, P.R.China Board of Directors: Yudong Chen, Patrick Leinenbach, Liming Chen