From: Theodore Ts'o Subject: Re: [PATCH REGRESSION FIX] ext4: fix mtime update in nodelalloc mode Date: Sun, 30 Sep 2012 16:30:26 -0400 Message-ID: <20120930203026.GD4780@thunk.org> References: <20120930195124.GF18169@1wt.eu> <20120930195002.GA30441@elie.Belkin> <20120930195341.GC4780@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ext4 Developers List , linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jan Kara , KONISHI Ryusuke , stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jonathan Nieder , Willy Tarreau Return-path: Content-Disposition: inline In-Reply-To: <20120930195341.GC4780-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org> Sender: linux-nilfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-ext4.vger.kernel.org The rewritten commit description: ext4: fix mtime update in nodelalloc mode Commits 5e8830dc85d0 and 41c4d25f78c0 introduced a regression into 3.6-rc1 for ext4 in nodealloc mode, such that mtime updates would not take place for files modified via mmap if the page was already in the page cache. This would also affect ext3 file systems mounted using the ext4 file system driver. The problem was that ext4_page_mkwrite() had a shortcut which would avoid calling __block_page_mkwrite() under some circumstances, and the above two commit transferred the responsibility of calling file_update_time() to __block_page_mkwrite --- which woudln't get called in some circumstances. Since __block_page_mkwrite() only has three callers, block_page_mkwrite(), ext4_page_mkwrite, and nilfs_page_mkwrite(), the best way to solve this is to move the responsibility for calling file_update_time() to its caller. This problem was found via xfstests #215 with a file system mounted with -o nodelalloc. Signed-off-by: "Theodore Ts'o" Cc: Jan Kara Cc: KONISHI Ryusuke Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Note: If this gets pushed to Linus before the merge window opens, I'll drop the cc of stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, since the regression was introduced in 3.6-rc1. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html