Commit 27874115 authored Jun 25, 2020 by Bob Peterson Committed by Greg Kroah-Hartman Jul 22, 2020

gfs2: read-only mounts should grab the sd_freeze_gl glock



[ Upstream commit b780cc615ba4795a7ef0e93b19424828a5ad456a ]

Before this patch, only read-write mounts would grab the freeze
glock in read-only mode, as part of gfs2_make_fs_rw. So the freeze
glock was never initialized. That meant requests to freeze, which
request the glock in EX, were granted without any state transition.
That meant you could mount a gfs2 file system, which is currently
frozen on a different cluster node, in read-only mode.

This patch makes read-only mounts lock the freeze glock in SH mode,
which will block for file systems that are frozen on another node.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 827139ad

fs/gfs2/ops_fstype.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -1168,7 +1168,17 @@ static int gfs2_fill_super(struct super_block sb, struct fs_context fc)
		goto fail_per_node;
		}

		if (!sb_rdonly(sb)) {
		if (sb_rdonly(sb)) {
		struct gfs2_holder freeze_gh;

		error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
		GL_EXACT, &freeze_gh);
		if (error) {
		fs_err(sdp, "can't make FS RO: %d\n", error);
		goto fail_per_node;
		}
		gfs2_glock_dq_uninit(&freeze_gh);
		} else {
		error = gfs2_make_fs_rw(sdp);
		if (error) {
		fs_err(sdp, "can't make FS RW: %d\n", error);