diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
index 30ba715dbed7..346251fcb20b 100644
--- a/sys/kern/kern_ktrace.c
+++ b/sys/kern/kern_ktrace.c
@@ -807,6 +807,36 @@ ktr_psig(int sig, sig_t action, const sigset_t *mask,
 	ktraddentry(l, kte, KTA_WAITOK);
 }
 
+#include <sys/ksyms.h>
+#include <sys/pserialize.h>
+
+static void
+formatsymbol(char *buf, size_t len, vaddr_t addr)
+{
+	unsigned long start;
+	char offset[32];
+	const char *mod, *sym;
+	int s;
+
+	s = pserialize_read_enter();
+	if (ksyms_getname(&mod, &sym, addr, KSYMS_PROC|KSYMS_CLOSEST) != 0 ||
+	    ksyms_getval(mod, sym, &start, KSYMS_ANY) != 0) {
+		snprintf(buf, len, "0x%"PRIxVADDR, addr);
+	} else {
+		if (addr < start) { /* XXX ??? */
+			snprintf(offset, sizeof(offset), "-%zx",
+			    (size_t)(start - addr));
+		} else if (addr == start) {
+			offset[0] = '\0';
+		} else {
+			snprintf(offset, sizeof(offset), "-%zx",
+			    (size_t)(addr - start));
+		}
+		snprintf(buf, len, "%s:%s%s", mod, sym, offset);
+	}
+	pserialize_read_exit(s);
+}
+
 void
 ktr_csw(int out, int user, const struct syncobj *syncobj)
 {
@@ -826,10 +856,16 @@ ktr_csw(int out, int user, const struct syncobj *syncobj)
 	 */
 	if (syncobj == &mutex_syncobj || syncobj == &rw_syncobj)
 		return;
-	KASSERTMSG(!cpu_intr_p() && !cpu_softintr_p(),
-	    "[%s] syncobj=%p mutex_syncobj=%p rw_syncobj=%p",
-	    l->l_name ? l->l_name : p->p_comm,
-	    syncobj, &mutex_syncobj, &rw_syncobj);
+	if (__predict_false(cpu_intr_p() || cpu_softintr_p())) {
+		char syncobj_sym[128];
+
+		formatsymbol(syncobj_sym, sizeof(syncobj_sym),
+		    (vaddr_t)syncobj);
+		KASSERTMSG(!cpu_intr_p() && !cpu_softintr_p(),
+		    "[%s] syncobj=%s mutex_syncobj=%p rw_syncobj=%p",
+		    l->l_name ? l->l_name : p->p_comm,
+		    syncobj_sym, &mutex_syncobj, &rw_syncobj);
+	}
 
 	/*
 	 * We can't sleep if we're already going to sleep (if original
diff --git a/sys/kern/kern_turnstile.c b/sys/kern/kern_turnstile.c
index dc8e666aa896..5978f3afe964 100644
--- a/sys/kern/kern_turnstile.c
+++ b/sys/kern/kern_turnstile.c
@@ -384,6 +384,10 @@ turnstile_block(turnstile_t *ts, int q, wchan_t obj, syncobj_t *sobj)
 	tc = &turnstile_chains[hash];
 	lock = &turnstile_locks[hash].lock;
 
+	KASSERTMSG(sobj == &mutex_syncobj || sobj == &rw_syncobj,
+	    "sobj=%p mutex_syncobj=%p rw_syncobj=%p",
+	    sobj, &mutex_syncobj, &rw_syncobj);
+
 	KASSERT(q == TS_READER_Q || q == TS_WRITER_Q);
 	KASSERT(mutex_owned(lock));
 	KASSERT(l != NULL && l->l_ts != NULL);
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index 695010d1da0a..650bbc1bebaa 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -543,6 +543,7 @@ do_sys_mount(struct lwp *l, const char *type, enum uio_seg type_seg,
 {
 	struct vfsops *vfsops = NULL;	/* XXX gcc4.8 */
 	struct vnode *vp;
+	bool in_fstrans = false;
 	void *data_buf = data;
 	bool vfsopsrele = false;
 	size_t alloc_sz = 0;
@@ -556,6 +557,8 @@ do_sys_mount(struct lwp *l, const char *type, enum uio_seg type_seg,
 		vp = NULL;
 		goto done;
 	}
+	fstrans_start(vp->v_mount);
+	in_fstrans = true;
 
 	if (flags & (MNT_GETARGS | MNT_UPDATE)) {
 		vfsops = vp->v_mount->mnt_op;
@@ -626,6 +629,8 @@ do_sys_mount(struct lwp *l, const char *type, enum uio_seg type_seg,
     done:
 	if (vfsopsrele)
 		vfs_delref(vfsops);
+	if (in_fstrans)
+		fstrans_done(vp->v_mount);
     	if (vp != NULL) {
 	    	vrele(vp);
 	}