From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Becker Date: Sat, 29 Jun 2013 14:17:33 +0100 Subject: [Ocfs2-devel] ocfs2: Should move ocfs2_start_trans out of lock_page In-Reply-To: <51C80978.2030705@huawei.com> References: <51C1691F.8060504@huawei.com> <51C80978.2030705@huawei.com> Message-ID: <20130629131732.GI13405@ZenIV.linux.org.uk> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com I'm pretty sure we did it for a reason, which means we need to think about it more than just looking at ext4. Remember that we get access coming from other node actions. Joel On Mon, Jun 24, 2013 at 04:55:20PM +0800, Joseph Qi wrote: > Any different opinion? > > On 2013/6/19 16:17, Joseph Qi wrote: > > Currently ocfs2_start_trans/ocfs2_commit_trans are in > > lock_page/unlock_page. This may cause dead lock. > > > > Here is the situation: > > write -> lock_page -> ocfs2_start_trans -> ocfs2_commit_trans -> unlock_page > > ocfs2_start_trans/ocfs2_commit_trans calls > > jbd2_journal_start/jbd2_journal_stop which may also call lock_page. So > > if the page operated is unfortunately the same with the page to be > > committed, dead lock happens. > > > > In ext4, lock_page/unlock_page are in > > ext4_journal_start/ext4_journal_stop, this can avoid such kind of dead > > lock. So I think we should move ocfs2_start_trans/ocfs2_commit_trans out > > of lock_page/unlock_page. > > > > Totally there are 5 related functions: > > ocfs2_write_begin_nolock > > ocfs2_write_begin_inline > > ocfs2_write_end_nolock > > ocfs2_write_zero_page > > ocfs2_convert_inline_data_to_extents > > > > > > _______________________________________________ > > Ocfs2-devel mailing list > > Ocfs2-devel at oss.oracle.com > > https://oss.oracle.com/mailman/listinfo/ocfs2-devel > > > > > > > > _______________________________________________ > Ocfs2-devel mailing list > Ocfs2-devel at oss.oracle.com > https://oss.oracle.com/mailman/listinfo/ocfs2-devel --