Return-Path: Received: from int-mailstore01.merit.edu ([207.75.116.232]:60751 "EHLO int-mailstore01.merit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754656Ab1FLXoe (ORCPT ); Sun, 12 Jun 2011 19:44:34 -0400 Message-Id: <9203fc2b8c4edc9fcc695e2b0ccd7993727935bf.1307921138.git.rees@umich.edu> In-Reply-To: References: Date: Sun, 12 Jun 2011 19:44:32 -0400 Subject: [PATCH 18/34] pnfsblock: allow use of PG_owner_priv_1 flag From: Jim Rees To: linux-nfs@vger.kernel.org Cc: peter honeyman Sender: linux-nfs-owner@vger.kernel.org List-ID: Content-Type: text/plain MIME-Version: 1.0 From: Fred Isaman There is currently no good way for pnfs to communicate problems. For example - the linux read code first tries to do readahead through nfs_readpages. Failure there is ignored, and it will later call nfs_readpage. Failure there is also ignored, except that the lack of PG_uptodate is communicated back via -EIO. With pnfs, it would be useful to be able to communicate to nfs_readpage that direct disk IO failed on readahead, and that it should failover to using the MDS. Making the page flag PG_owner_priv_1 available as PG_pnfserr is one way to do so. (An alternative would be to embed this in the layout, but then pg_test can't easily access the info.) This may be better as generic pnfs code, in which case it should be put in pnfs.h, or even page-flags.h Signed-off-by: Fred Isaman Signed-off-by: Benny Halevy --- fs/nfs/blocklayout/blocklayout.h | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h index 21fa21c..293f009 100644 --- a/fs/nfs/blocklayout/blocklayout.h +++ b/fs/nfs/blocklayout/blocklayout.h @@ -35,6 +35,11 @@ #include #include "../pnfs.h" +#define PG_pnfserr PG_owner_priv_1 +#define PagePnfsErr(page) test_bit(PG_pnfserr, &(page)->flags) +#define SetPagePnfsErr(page) set_bit(PG_pnfserr, &(page)->flags) +#define ClearPagePnfsErr(page) clear_bit(PG_pnfserr, &(page)->flags) + struct block_mount_id { spinlock_t bm_lock; /* protects list */ struct list_head bm_devlist; /* holds pnfs_block_dev */ -- 1.7.4.1