NFS: prepare coalesce testing for directio

The coalesce code made assumptions that will no longer be true once
non-page aligned io occurs.  This introduces no change in
current behavior, but allows for more general situations to come.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 5d01a165108..638ca7f5a1e 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -280,12 +280,12 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
                 return false;
         if (req->wb_context->state != prev->wb_context->state)
                 return false;
-        if (req->wb_index != (prev->wb_index + 1))
-                return false;
         if (req->wb_pgbase != 0)
                 return false;
         if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
                 return false;
+        if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
+                return false;
         return pgio->pg_ops->pg_test(pgio, prev, req);
 }