On Tue, 2012-12-11 at 18:16 -0500, Trond Myklebust wrote:
> Hmm... I can see 2 places where we're setting the PageError flag.
>
> 1. nfs_updatepage(): in this case, the error occurred when we tried
> to change the page contents. Since we're holding the page lock,
> and so rather than mark the page as bad, we could probably just
> write back existing dirty areas (using nfs_wb_page()) and then
> remove it from the mapping.
> 2. nfs_write_completion(): here the writeback error applies to the
> entire dirty area on the page, and there is no point in try to
> write back again. Better just evict the page from the page cache
> (which is what nfs_zap_mapping() is supposed to do). While
> setting the PageError flag does cause some of the writeback
> functions to return EIO, that's not really what we're after; we
> already report errors more completely via the open context.
>
> So for now, can't we just change nfs_set_pageerror() to not bother
> setting the PG_error flag? Then in the future we might want to make
> nfs_updatepage a bit more sophisticated in how it deals with those
> errors...
Ultimately, what I'm saying is that PageError is a hack for passing
errors around. Since we have our own hack for doing the same, then why
use PageError at all?
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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