NFSv4.1: Fix some issues with pnfs_generic_pg_test
1. If the intention is to coalesce requests 'prev' and 'req' then we
have to ensure at least that we have a layout starting at
req_offset(prev).
2. If we're only requesting a minimal layout of length desc->pg_count,
we need to test the length actually returned by the server before
we allow the coalescing to occur.
3. We need to deal correctly with (pgio->lseg == NULL)
4. Fixup the test guarding the pnfs_update_layout.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index eb4aafa..8ff2ea3 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -1000,6 +1000,9 @@
if (!pnfs_generic_pg_test(pgio, prev, req))
return false;
+ if (pgio->pg_lseg == NULL)
+ return true;
+
return pgio->pg_count + req->wb_bytes <=
OBJIO_LSEG(pgio->pg_lseg)->max_io_size;
}