From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Price Date: Mon, 15 Mar 2021 12:24:00 +0000 Subject: [Cluster-devel] [PATCH] gfs2: Flag a withdraw if init_threads() fails Message-ID: <20210315122400.1636159-1-anprice@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Interrupting mount with ^C quickly enough can cause the kthread_run() calls in gfs2's init_threads() to fail and the error path leads to a deadlock on the s_umount rwsem. The abridged chain of events is: [mount path] get_tree_bdev() sget_fc() alloc_super() down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING); [acquired] gfs2_fill_super() gfs2_make_fs_rw() init_threads() kthread_run() ( Interrupted ) [Error path] gfs2_gl_hash_clear() flush_workqueue(glock_workqueue) wait_for_completion() [workqueue context] glock_work_func() run_queue() do_xmote() freeze_go_sync() freeze_super() down_write(&sb->s_umount) [deadlock] In freeze_go_sync() there is a gfs2_withdrawn() check that we can use to make sure freeze_super() is not called in the error path, so add a gfs2_withdraw_delayed() call when init_threads() fails. Ref: https://bugzilla.kernel.org/show_bug.cgi?id=212231 Reported-by: Alexander Aring Signed-off-by: Andrew Price --- fs/gfs2/super.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c index 97076d3f562f..9e91c9d92bd6 100644 --- a/fs/gfs2/super.c +++ b/fs/gfs2/super.c @@ -162,8 +162,10 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp) int error; error = init_threads(sdp); - if (error) + if (error) { + gfs2_withdraw_delayed(sdp); return error; + } j_gl->gl_ops->go_inval(j_gl, DIO_METADATA); if (gfs2_withdrawn(sdp)) { -- 2.29.2