NFSv4.1: coelesce across layout stripes

Add a pg_test layout driver hook which is used to avoid coelescing I/O across
layout stripes.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index d55cee73f634..4eaf27a1282d 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -62,6 +62,8 @@ struct nfs_pageio_descriptor {
         int                     (*pg_doio)(struct inode *, struct list_head *, unsigned int, size_t, int);
         int                     pg_ioflags;
         int                     pg_error;
+        struct pnfs_layout_segment *pg_lseg;
+        int                     (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
 };
 
 #define NFS_WBACK_BUSY(req)     (test_bit(PG_BUSY,&(req)->wb_flags))