From: "Amit K. Arora" Subject: Re: [PATCH 1/5][TAKE3] fallocate() implementation on i86, x86_64 and powerpc Date: Wed, 16 May 2007 18:07:05 +0530 Message-ID: <20070516123705.GB24299@amitarora.in.ibm.com> References: <20070418130600.GW5967@schatzie.adilger.int> <20070420135146.GA21352@amitarora.in.ibm.com> <20070420145918.GY355@devserv.devel.redhat.com> <20070424121632.GA10136@amitarora.in.ibm.com> <20070426175056.GA25321@amitarora.in.ibm.com> <20070515193722.GA3487@amitarora.in.ibm.com> <20070515195421.GA2948@amitarora.in.ibm.com> <20070515200359.GA5834@amitarora.in.ibm.com> <20070516031626.GM85884050@sgi.com> <1179318076.10313.6.camel@kleikamp.austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Chinner , torvalds@osdl.org, akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, xfs@oss.sgi.com, suparna@in.ibm.com, cmm@us.ibm.com To: Dave Kleikamp Return-path: Content-Disposition: inline In-Reply-To: <1179318076.10313.6.camel@kleikamp.austin.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Wed, May 16, 2007 at 07:21:16AM -0500, Dave Kleikamp wrote: > On Wed, 2007-05-16 at 13:16 +1000, David Chinner wrote: > > On Wed, May 16, 2007 at 01:33:59AM +0530, Amit K. Arora wrote: > > > > Following changes were made to the previous version: > > > 1) Added description before sys_fallocate() definition. > > > 2) Return EINVAL for len<=0 (With new draft that Ulrich pointed to, > > > posix_fallocate should return EINVAL for len <= 0. > > > 3) Return EOPNOTSUPP if mode is not one of FA_ALLOCATE or FA_DEALLOCATE > > > 4) Do not return ENODEV for dirs (let individual file systems decide if > > > they want to support preallocation to directories or not. > > > 5) Check for wrap through zero. > > > 6) Update c/mtime if fallocate() succeeds. > > > > Please don't make this always happen. c/mtime updates should be dependent > > on the mode being used and whether there is visible change to the file. If no > > userspace visible changes to the file occurred, then timestamps should not > > be changed. > > i_blocks will be updated, so it seems reasonable to update ctime. mtime > shouldn't be changed, though, since the contents of the file will be > unchanged. I agree. Thus the ctime should change for FA_PREALLOCATE mode also (which does not change the file size) - if we end up having this additional mode in near future. -- Regards, Amit Arora > > e.g. FA_ALLOCATE that changes file size requires same semantics of ftruncate() > > extending the file, otherwise no change in timestamps should occur. > > > > Cheers, > > > > Dave. > -- > David Kleikamp > IBM Linux Technology Center