From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Sat, 18 Jul 2009 15:18:49 +0000 (-0700)
Subject: NFS - Fix panic on umount/reboot
X-Git-Tag: v2.4.0~412
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/524e83aa4f0548c1eb2660bddd4915f04fdf32b4

NFS - Fix panic on umount/reboot

* The rx thread sometimes gets no-error and 0-bytes returned from
  its soreceive call, but the caller expects a mbuf in that case.
  Check for the case and convert to EPIPE.
---

diff --git a/sys/vfs/nfs/nfs_socket.c b/sys/vfs/nfs/nfs_socket.c
index aa477befca..02bfb56c6c 100644
--- a/sys/vfs/nfs/nfs_socket.c
+++ b/sys/vfs/nfs/nfs_socket.c
@@ -712,13 +712,22 @@ errout:
 				return (EINTR);
 			}
 		} while (error == EWOULDBLOCK);
+
 		len = sio.sb_cc;
 		*mp = sio.sb_mb;
+
+		/*
+		 * A shutdown may result in no error and no mbuf.
+		 * Convert to EPIPE.
+		 */
+		if (*mp == NULL && error == 0)
+			error = EPIPE;
 	}
 	if (error) {
 		m_freem(*mp);
 		*mp = NULL;
 	}
+
 	/*
 	 * Search for any mbufs that are not a multiple of 4 bytes long
 	 * or with m_data not longword aligned.