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, 16 insertions, 0 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 3afa82e45438..330cee115de0 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -858,6 +858,22 @@ out_forget_reply:
         goto out;
 }
 
+static void
+pnfs_set_pg_test(struct inode *inode, struct nfs_pageio_descriptor *pgio)
+{
+        struct pnfs_layoutdriver_type *ld;
+
+        ld = NFS_SERVER(inode)->pnfs_curr_ld;
+        pgio->pg_test = (ld ? ld->pg_test : NULL);
+}
+
+void
+pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
+                  struct inode *inode)
+{
+        pnfs_set_pg_test(inode, pgio);
+}
+
 /*
  * Device ID cache. Currently supports one layout type per struct nfs_client.
  * Add layout type to the lookup key to expand to support multiple types.