From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by wa-out-1112.google.com with SMTP id m33so1266959wag.8 for ; Thu, 10 Jan 2008 08:40:41 -0800 (PST) Message-ID: <4df4ef0c0801100840uf84fef6g80e456fc5681193@mail.gmail.com> Date: Thu, 10 Jan 2008 19:40:41 +0300 From: "Anton Salikhmetov" Subject: Re: [PATCH][RFC][BUG] updating the ctime and mtime time stamps in msync() In-Reply-To: <20080110110757.09ec494a@bree.surriel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1199728459.26463.11.camel@codedot> <20080109170633.292644dc@cuia.boston.redhat.com> <20080109223340.GH25527@unthought.net> <20080109184141.287189b8@bree.surriel.com> <4df4ef0c0801091603y2bf507e1q2b99971c6028d1f3@mail.gmail.com> <20080110085120.GK25527@unthought.net> <4df4ef0c0801100253m6c08e4a3t917959c030533f80@mail.gmail.com> <20080110104543.398baf5c@bree.surriel.com> <4df4ef0c0801100756v2a536cc5xa80d9d1cfdae073a@mail.gmail.com> <20080110110757.09ec494a@bree.surriel.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Jakob Oestergaard , Valdis.Kletnieks@vt.edu, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: 2008/1/10, Rik van Riel : > On Thu, 10 Jan 2008 18:56:07 +0300 > "Anton Salikhmetov" wrote: > > > However, I don't see how they will work if there has been > > something like a sync(2) done after the mmap'd region is > > modified and the msync call. When the inode is written out > > as part of the sync process, I_DIRTY_PAGES will be cleared, > > thus causing a miss in this code. > > > > The I_DIRTY_PAGES check here is good, but I think that there > > needs to be some code elsewhere too, to catch the case where > > I_DIRTY_PAGES is being cleared, but the time fields still need > > to be updated. > > Agreed. The mtime and ctime should probably also be updated > when I_DIRTY_PAGES is cleared. > > The alternative would be to remember that the inode had been > dirty in the past, and have the mtime and ctime updated on > msync or close - which would be more complex. Adding the new flag (AS_MCTIME) has been already suggested by Peter Staubach in his first solution for this bug. Now I understand that the AS_MCTIME flag is required for fixing the bug. > > -- > All rights reversed. > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org