From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Date: Wed, 16 Nov 2011 16:57:55 +0100 Subject: [Cluster-devel] fallocate vs O_(D)SYNC In-Reply-To: <20111116134234.GA24258@infradead.org> References: <20111116084256.GA22963@infradead.org> <1321436588.2713.5.camel@menhir> <20111116105413.GA2916@quack.suse.cz> <20111116124550.GA11650@infradead.org> <20111116133915.GD8195@quack.suse.cz> <20111116134234.GA24258@infradead.org> Message-ID: <20111116155755.GA22284@quack.suse.cz> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Wed 16-11-11 08:42:34, Christoph Hellwig wrote: > On Wed, Nov 16, 2011 at 02:39:15PM +0100, Jan Kara wrote: > > > 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. > > OK, I don't really have a strong opinion here. Are you afraid that just > > calling fsync() need not be enough to push all updates fallocate did to > > disk? > > No, the point is that you should not have to call fsync when doing > O_SYNC I/O. That's the whole point of it. I agree with you that userspace shouldn't have to call fsync. What I meant is that sys_fallocate() or do_fallocate() can call generic_write_sync(file, pos, len), and that would be completely transparent to userspace. Honza