git: c34a5148e8f2 - main - ffs: fix newly introduced LOR between mntfs vnode lock and topology lock

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=c34a5148e8f21e9be28330c4ae4884b6f31193dd

commit c34a5148e8f21e9be28330c4ae4884b6f31193dd
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2021-11-16 17:31:11 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2021-11-16 18:01:31 +0000

    ffs: fix newly introduced LOR between mntfs vnode lock and topology lock
    
    The mntfs vnode lock should be before topology, as established in
    ffs_mountfs().  Extend the locked region in ffs_unmount().
    
    Reported and reviewed by:       markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D33013
---
 sys/geom/geom_vfs.c      | 2 --
 sys/ufs/ffs/ffs_vfsops.c | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/sys/geom/geom_vfs.c b/sys/geom/geom_vfs.c
index 9590fee11000..ab068d7c85d5 100644
--- a/sys/geom/geom_vfs.c
+++ b/sys/geom/geom_vfs.c
@@ -309,9 +309,7 @@ g_vfs_close(struct g_consumer *cp)
 	gp = cp->geom;
 	sc = gp->softc;
 	vp = cp->private;
-	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 	bufobj_invalbuf(sc->sc_bo, V_SAVE, 0, 0);
-	VOP_UNLOCK(vp);
 	sc->sc_bo->bo_private = cp->private;
 	gp->softc = NULL;
 	mtx_destroy(&sc->sc_mtx);
diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index f2ea6b666fad..1edc127bd68c 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -1431,6 +1431,7 @@ ffs_unmount(mp, mntflags)
 		taskqueue_free(ump->um_trim_tq);
 		free (ump->um_trimhash, M_TRIM);
 	}
+	vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
 	g_topology_lock();
 	g_vfs_close(ump->um_cp);
 	g_topology_unlock();
@@ -1438,7 +1439,6 @@ ffs_unmount(mp, mntflags)
 	ump->um_odevvp->v_bufobj.bo_flag &= ~BO_NOBUFS;
 	BO_UNLOCK(&ump->um_odevvp->v_bufobj);
 	atomic_store_rel_ptr((uintptr_t *)&ump->um_dev->si_mountpt, 0);
-	vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
 	mntfs_freevp(ump->um_devvp);
 	vrele(ump->um_odevvp);
 	dev_rel(ump->um_dev);