From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Yu Subject: Re: [PATCH] f2fs: avoid GC causing encrypted file corrupted Date: Tue, 18 Sep 2018 21:21:49 +0800 Message-ID: <19e63fa7-1a48-c1de-eef5-cde242e8300d@kernel.org> References: <1537274393-78441-1-git-send-email-yunlong.song@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1537274393-78441-1-git-send-email-yunlong.song@huawei.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Yunlong Song , jaegeuk@kernel.org, yuchao0@huawei.com, yunlong.song@icloud.com Cc: miaoxie@huawei.com, bintian.wang@huawei.com, shengyong1@huawei.com, heyunlei@huawei.com, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org List-Id: linux-f2fs-devel.lists.sourceforge.net On 2018/9/18 20:39, Yunlong Song wrote: > The encrypted file may be corrupted by GC in following case: > > Time 1: | segment 1 blkaddr = A | GC -> | segment 2 blkaddr = B | > Encrypted block 1 is moved from blkaddr A of segment 1 to blkaddr B of > segment 2, > > Time 2: | segment 1 blkaddr = B | GC -> | segment 3 blkaddr = C | > > Before page 1 is written back and if segment 2 become a victim, then > page 1 is moved from blkaddr B of segment 2 to blkaddr Cof segment 3, > during the GC process of Time 2, f2fs should wait for page 1 written back > before reading it, or move_data_block will read a garbage block from > blkaddr B since page is not written back to blkaddr B yet. > > Commit 6aa58d8a ("f2fs: readahead encrypted block during GC") introduce > ra_data_block to read encrypted block, but it forgets to add > f2fs_wait_on_page_writeback to avoid racing between GC and flush. > > Signed-off-by: Yunlong Song Reviewed-by: Chao Yu Thanks,