NFS41: send real read size in layoutget

For buffer read, use offst-to-isize.

For direct read, use dreq->bytes_left.

Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 9a2bcce4528..fe624c91bd0 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1220,16 +1220,24 @@ out_forget_reply:
 void
 pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
 {
+        u64 rd_size = req->wb_bytes;
+
         BUG_ON(pgio->pg_lseg != NULL);
 
         if (req->wb_offset != req->wb_pgbase) {
                 nfs_pageio_reset_read_mds(pgio);
                 return;
         }
+
+        if (pgio->pg_dreq == NULL)
+                rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
+        else
+                rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
+
         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
                                            req->wb_context,
                                            req_offset(req),
-                                           req->wb_bytes,
+                                           rd_size,
                                            IOMODE_READ,
                                            GFP_KERNEL);
         /* If no lseg, fall back to read through mds */