1 files changed, 31 insertions, 4 deletions

diff --git a/init/do_mounts.c b/init/do_mounts.c
index 0f6e1d985a3b..db6e5ee0e1db 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -398,15 +398,42 @@ out:
 }
  
 #ifdef CONFIG_ROOT_NFS
+
+#define NFSROOT_TIMEOUT_MIN     5
+#define NFSROOT_TIMEOUT_MAX     30
+#define NFSROOT_RETRY_MAX       5
+
 static int __init mount_nfs_root(void)
 {
         char *root_dev, *root_data;
+        unsigned int timeout;
+        int try, err;
 
-        if (nfs_root_data(&root_dev, &root_data) != 0)
-                return 0;
-        if (do_mount_root(root_dev, "nfs", root_mountflags, root_data) != 0)
+        err = nfs_root_data(&root_dev, &root_data);
+        if (err != 0)
                 return 0;
-        return 1;
+
+        /*
+         * The server or network may not be ready, so try several
+         * times.  Stop after a few tries in case the client wants
+         * to fall back to other boot methods.
+         */
+        timeout = NFSROOT_TIMEOUT_MIN;
+        for (try = 1; ; try++) {
+                err = do_mount_root(root_dev, "nfs",
+                                        root_mountflags, root_data);
+                if (err == 0)
+                        return 1;
+                if (try > NFSROOT_RETRY_MAX)
+                        break;
+
+                /* Wait, in case the server refused us immediately */
+                ssleep(timeout);
+                timeout <<= 1;
+                if (timeout > NFSROOT_TIMEOUT_MAX)
+                        timeout = NFSROOT_TIMEOUT_MAX;
+        }
+        return 0;
 }
 #endif