Re: [PATCH 0/2] Improve writeout pattern from xfs_flush_pages()

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Thu, Aug 04, 2011 at 02:07:24PM +0200, Jan Kara wrote:
>   Hmm, BTW, shouldn't the call to xfs_flush_pages() in
> xfs_file_buffered_aio_write() be converted to an asynchronous one? I don't
> quite see a point in waiting for io completion... Generally, flushing of
> the inode there seems of limited usefulness to me since that inode could be
> just a tiny victim not holding much delayallocated blocks.

This comes from commit

        xfs: make inode flush at ENOSPC synchronous

from Dave - before that it was asynchronous and in weird context, so
it seems we defintively need it to be synchronous.  I agree that just
flushing this inode seems like a rather odd handling for ENOSPC.  It's
even more odd as we already use the big hammer before in when we
git ENOSPC in ->write_begin.  The only thing I can imagine is that
this is the last attempt to get anything freed.