2 files changed, 17 insertions, 1 deletions

diff --git a/sys/nfsclient/nfs_nfsiod.c b/sys/nfsclient/nfs_nfsiod.c
index d34c205a48e5..2fb2c88151ac 100644
--- a/sys/nfsclient/nfs_nfsiod.c
+++ b/sys/nfsclient/nfs_nfsiod.c
@@ -308,6 +308,14 @@ nfssvc_iod(void *instance)
 			mtx_unlock(&Giant);
 		mtx_lock(&nfs_iod_mtx);
 		/*
+		 * Make sure the nmp hasn't been dismounted as soon as
+		 * nfs_doio() completes for the last buffer.
+		 */
+		nmp = nfs_iodmount[myiod];
+		if (nmp == NULL)
+			break;
+
+		/*
 		 * If there are more than one iod on this mount, then defect
 		 * so that the iods can be shared out fairly between the mounts
 		 */
diff --git a/sys/nfsclient/nfs_vfsops.c b/sys/nfsclient/nfs_vfsops.c
index 6f00cf90de2f..7a26aa20aff1 100644
--- a/sys/nfsclient/nfs_vfsops.c
+++ b/sys/nfsclient/nfs_vfsops.c
@@ -1362,7 +1362,7 @@ static int
 nfs_unmount(struct mount *mp, int mntflags)
 {
 	struct nfsmount *nmp;
-	int error, flags = 0;
+	int error, flags = 0, i;
 
 	if (mntflags & MNT_FORCE)
 		flags |= FORCECLOSE;
@@ -1387,6 +1387,14 @@ nfs_unmount(struct mount *mp, int mntflags)
 	/*
 	 * We are now committed to the unmount.
 	 */
+	/* Make sure no nfsiods are assigned to this mount. */
+	mtx_lock(&nfs_iod_mtx);
+	for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
+		if (nfs_iodmount[i] == nmp) {
+			nfs_iodwant[i] = NFSIOD_AVAILABLE;
+			nfs_iodmount[i] = NULL;
+		}
+	mtx_unlock(&nfs_iod_mtx);
 	nfs_disconnect(nmp);
 	free(nmp->nm_nam, M_SONAME);