nfs: can_coalesce_requests must enforce contiguity

[firefly-linux-kernel-4.4.55.git] / fs / nfs / pagelist.c

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index a1d1de7b97c5fdeb6e7665c81c091db8eefaad65..932c6cc27a7664a29c9bf8d5883990c510e59b02 100644 (file)
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -823,6 +823,14 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
                        return false;
                if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
                        return false;
+               if (req->wb_page == prev->wb_page) {
+                       if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)
+                               return false;
+               } else {
+                       if (req->wb_pgbase != 0 ||
+                           prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
+                               return false;
+               }
        }
        size = pgio->pg_ops->pg_test(pgio, prev, req);
        WARN_ON_ONCE(size > req->wb_bytes);