Return-Path: Received: from int-mailstore01.merit.edu ([207.75.116.232]:53566 "EHLO int-mailstore01.merit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755510Ab1FGR3B (ORCPT ); Tue, 7 Jun 2011 13:29:01 -0400 Date: Tue, 7 Jun 2011 13:28:59 -0400 From: Jim Rees To: Benny Halevy Cc: linux-nfs@vger.kernel.org, peter honeyman Subject: [PATCH 26/88] pnfsblock: allow use of PG_owner_priv_1 flag Message-ID: <000c46737b1da856c36c79afdd515f1a2e13f6ad.1307464382.git.rees@umich.edu> References: Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 8b06c93..493d4d3 100644 --- a/fs/nfs/blocklayout/blocklayout.h +++ b/fs/nfs/blocklayout/blocklayout.h @@ -37,6 +37,11 @@ #include #include /* Needed for struct dm_ioctl*/ +#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) + extern struct class shost_class; /* exported from drivers/scsi/hosts.c */ extern int dm_dev_create(struct dm_ioctl *param); /* from dm-ioctl.c */ extern int dm_dev_remove(struct dm_ioctl *param); /* from dm-ioctl.c */ -- 1.7.4.1