Re: Syncing single filesystem (slow USB writing)

[Andrew Morton <akpm@osdl.org>]

Andrey Borzenkov <arvidjaar@mail.ru> wrote:
>
> On Friday 29 July 2005 15:20, Andrew Morton wrote:
> > Andrey Borzenkov <arvidjaar@mail.ru> wrote:
> > > On Friday 29 July 2005 07:50, Andrew Morton wrote:
> > > > > One idea how to improve situation - continue to mount with dsync
> > > > > (having basically old case) and do frequent sync of filesystem (this
> > > > > culd be started as HAL callout or whatever). Unfortunately, I could
> > > > > not find a way to request a sync (flush) of single mount point or
> > > > > block device. Have I missed something?
> > > >
> > > > It's trivial to do in-kernel but no, I'm afraid there isn't a userspace
> > > > interface for this.
> > >
> > > apparently one should not ask such a question at 7 am. Any reason why
> > > BLKFLSBUF does not suite?
> >
> > That'll only write back data associated with /dev/hdXX (ie: filesystem
> > metadata) and not the data associated with all the files in the filesystem
> > which is mounted on /dev/hdXX.
> 
> I am confused. BKLFLSBUF boils down to sync_inodes_sb for mounted device, and 
> that appears to write out direty inode pages?

Oh, you're right.  How cunning.  Yes, `blockdev --flushbufs /dev/hda1'
would indeed appear to sync all data associated with that device.