From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Fri, 5 Feb 2010 00:16:58 +0000 (-0800)
Subject: kernel - fix panic on reboot when swap populated
X-Git-Tag: v2.7.1~229^2~12
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/7d3c02193be873b1bd2cc70f838bd8deb63f0be2

kernel - fix panic on reboot when swap populated

* The swapvp does not have a v_mount so do not try to access
  the mount lock through it if v_mount is NULL.
---

diff --git a/sys/kern/vfs_vopops.c b/sys/kern/vfs_vopops.c
index de8130d717..918d8f3983 100644
--- a/sys/kern/vfs_vopops.c
+++ b/sys/kern/vfs_vopops.c
@@ -818,9 +818,16 @@ vop_strategy(struct vop_ops *ops, struct vnode *vp, struct bio *bio)
 	ap.a_vp = vp;
 	ap.a_bio = bio;
 
-	VFS_MPLOCK1(vp->v_mount);
-	DO_OPS(ops, error, &ap, vop_strategy);
-	VFS_MPUNLOCK(vp->v_mount);
+	if (vp->v_mount) {
+		VFS_MPLOCK1(vp->v_mount);
+		DO_OPS(ops, error, &ap, vop_strategy);
+		VFS_MPUNLOCK(vp->v_mount);
+	} else {
+		/* ugly hack for swap */
+		get_mplock();
+		DO_OPS(ops, error, &ap, vop_strategy);
+		rel_mplock();
+	}
 	return(error);
 }