[PATCH] xfs: ensure log covering transactions are synchronous

[Alex Elder]

On Tue, 2011-01-04 at 15:49 +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner at redhat.com>
> 
> To ensure the log is covered and the filesystem idles correctly, we
> need to ensure that dummy transactions hit the disk and do not stay
> pinned in memory.  If the superblock is pinned in memory, it can't
> be flushed so the log covering cannot make progress. The result is
> dependent on timing - more oftent han not we continue to issues a
> log covering transaction every 36s rather than idling after ~90s.
> 
> Fix this by making the log covering transaction synchronous. To
> avoid additional log force from xfssyncd, make the log covering
> transaction take the place of the existing log force in the xfssyncd
> background sync process.
> 

Looks good.

Reviewed-by: Alex Elder <aelder at sgi.com>

> Signed-off-by: Dave Chinner <dchinner at redhat.com>
> ---