From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Wed, 16 Nov 2011 07:45:50 -0500 Subject: [Cluster-devel] fallocate vs O_(D)SYNC In-Reply-To: <20111116105413.GA2916@quack.suse.cz> References: <20111116084256.GA22963@infradead.org> <1321436588.2713.5.camel@menhir> <20111116105413.GA2916@quack.suse.cz> Message-ID: <20111116124550.GA11650@infradead.org> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Wed, Nov 16, 2011 at 11:54:13AM +0100, Jan Kara wrote: > Yeah, only that nobody calls that fsync() automatically if the fd is > O_SYNC if I'm right. But maybe calling fdatasync() on the range which was > fallocated from sys_fallocate() if the fd is O_SYNC would do the trick for > most filesystems? That would match how we treat O_SYNC for other operations > as well. I'm just not sure whether XFS wouldn't take unnecessarily big hit > with this. This would work fine with XFS and be equivalent to what it does for O_DSYNC now. But I'd rather see every filesystem do the right thing and make sure the update actually is on disk when doing O_(D)SYNC operations.