| Message ID | 9203fc2b8c4edc9fcc695e2b0ccd7993727935bf.1307921138.git.rees@umich.edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Jun 12, 2011 at 7:44 PM, Jim Rees <rees@umich.edu> wrote: > From: Fred Isaman <iisaman@citi.umich.edu> > > 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 <iisaman@citi.umich.edu> > Signed-off-by: Benny Halevy <bhalevy@panasas.com> > --- The error handling has changed a bit since this was written. It is currently very course grained for simplicity reasons. Is there any reason you can't do similarly, and just use NFS_LAYOUT_{RW|RO}_FAILED in lo->plh_flags? Fred > 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 <linux/nfs_fs.h> > #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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 <linux/nfs_fs.h> #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 */