From 5dc43eb0f66de2e7de1d6459c865d4df6c4221cc Mon Sep 17 00:00:00 2001
From: Chuck Lever <chuck.lever@oracle.com>
Date: Mon, 5 Dec 2011 15:40:30 -0500
Subject: [PATCH] --- yaml --- r: 282931 b: refs/heads/master c:
 43717c7daebf10b43f12e68512484b3095bb1ba5 h: refs/heads/master i:   282929:
 92b8b70b1045a78ff4baca7d704f37353dc6ae1d   282927:
 d614fc1e3434ff07fd13c2bba3a7c814ee686bdb v: v3

---
 [refs]                 |  2 +-
 trunk/init/do_mounts.c | 35 +++++++++++++++++++++++++++++++----
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 27b28018270b..44bd9959d75d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 68c97153fb7f2877f98aa6c29546381d9cad2fed
+refs/heads/master: 43717c7daebf10b43f12e68512484b3095bb1ba5
diff --git a/trunk/init/do_mounts.c b/trunk/init/do_mounts.c
index 0f6e1d985a3b..db6e5ee0e1db 100644
--- a/trunk/init/do_mounts.c
+++ b/trunk/init/do_mounts.c
@@ -398,15 +398,42 @@ void __init mount_block_root(char *name, int flags)
 }
  
 #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