Index: sys/kern/vfs_export.c
===================================================================
--- sys/kern/vfs_export.c	(revision 203085)
+++ sys/kern/vfs_export.c	(working copy)
@@ -279,7 +279,7 @@ vfs_export(struct mount *mp, struct export_args *a
 		return (EINVAL);
 
 	error = 0;
-	lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL);
+	sx_xlock(&mp->mnt_explock);
 	nep = mp->mnt_export;
 	if (argp->ex_flags & MNT_DELEXPORT) {
 		if (nep == NULL) {
@@ -320,7 +320,7 @@ vfs_export(struct mount *mp, struct export_args *a
 	}
 
 out:
-	lockmgr(&mp->mnt_explock, LK_RELEASE, NULL);
+	sx_xunlock(&mp->mnt_explock);
 	/*
 	 * Once we have executed the vfs_export() command, we do
 	 * not want to keep the "export" option around in the
@@ -472,10 +472,10 @@ vfs_stdcheckexp(struct mount *mp, struct sockaddr
 {
 	struct netcred *np;
 
-	lockmgr(&mp->mnt_explock, LK_SHARED, NULL);
+	sx_slock(&mp->mnt_explock);
 	np = vfs_export_lookup(mp, nam);
 	if (np == NULL) {
-		lockmgr(&mp->mnt_explock, LK_RELEASE, NULL);
+		sx_sunlock(&mp->mnt_explock);
 		*credanonp = NULL;
 		return (EACCES);
 	}
@@ -486,7 +486,7 @@ vfs_stdcheckexp(struct mount *mp, struct sockaddr
 		*numsecflavors = np->netc_numsecflavors;
 	if (secflavors)
 		*secflavors = np->netc_secflavors;
-	lockmgr(&mp->mnt_explock, LK_RELEASE, NULL);
+	sx_sunlock(&mp->mnt_explock);
 	return (0);
 }
 
Index: sys/kern/vfs_mount.c
===================================================================
--- sys/kern/vfs_mount.c	(revision 203085)
+++ sys/kern/vfs_mount.c	(working copy)
@@ -459,7 +459,7 @@ mount_init(void *mem, int size, int flags)
 
 	mp = (struct mount *)mem;
 	mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
-	lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0);
+	sx_init(&mp->mnt_explock, "explock");
 	return (0);
 }
 
@@ -469,7 +469,7 @@ mount_fini(void *mem, int size)
 	struct mount *mp;
 
 	mp = (struct mount *)mem;
-	lockdestroy(&mp->mnt_explock);
+	sx_destroy(&mp->mnt_explock);
 	mtx_destroy(&mp->mnt_mtx);
 }
 
Index: sys/fs/nfsserver/nfs_nfsdport.c
===================================================================
--- sys/fs/nfsserver/nfs_nfsdport.c	(revision 203085)
+++ sys/fs/nfsserver/nfs_nfsdport.c	(working copy)
@@ -3093,7 +3093,7 @@ nfsd_modevent(module_t mod, int type, void *data)
 		mtx_init(&nfs_v4root_mutex, "nfs_v4root_mutex", NULL, MTX_DEF);
 		mtx_init(&nfsv4root_mnt.mnt_mtx, "struct mount mtx", NULL,
 		    MTX_DEF);
-		lockinit(&nfsv4root_mnt.mnt_explock, PVFS, "explock", 0, 0);
+		sx_init(&nfsv4root_mnt.mnt_explock, "explock");
 		nfsrvd_initcache();
 		nfsd_init();
 		NFSD_LOCK();
@@ -3125,7 +3125,7 @@ nfsd_modevent(module_t mod, int type, void *data)
 		mtx_destroy(&nfs_cache_mutex);
 		mtx_destroy(&nfs_v4root_mutex);
 		mtx_destroy(&nfsv4root_mnt.mnt_mtx);
-		lockdestroy(&nfsv4root_mnt.mnt_explock);
+		sx_destroy(&nfsv4root_mnt.mnt_explock);
 		loaded = 0;
 		break;
 	default:
Index: sys/sys/mount.h
===================================================================
--- sys/sys/mount.h	(revision 203085)
+++ sys/sys/mount.h	(working copy)
@@ -37,7 +37,7 @@
 #include <sys/queue.h>
 #ifdef _KERNEL
 #include <sys/lock.h>
-#include <sys/lockmgr.h>
+#include <sys/sx.h>
 #include <sys/_mutex.h>
 #endif
 
@@ -186,7 +186,7 @@ struct mount {
 	struct thread	*mnt_susp_owner;	/* (i) thread owning suspension */
 #define	mnt_endzero	mnt_gjprovider
 	char		*mnt_gjprovider;	/* gjournal provider name */
-	struct lock	mnt_explock;		/* vfs_export walkers lock */
+	struct sx	mnt_explock;		/* vfs_export walkers lock */
 };
 
 struct vnode *__mnt_vnode_next(struct vnode **mvp, struct mount *mp);