From: Andrew Price anprice@redhat.com
[ Upstream commit 62dd0f98a0e5668424270b47a0c2e973795faba7 ]
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 aahringo@redhat.com Signed-off-by: Andrew Price anprice@redhat.com Signed-off-by: Andreas Gruenbacher agruenba@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 ddd40c96f7a2..0581612dd91e 100644 --- a/fs/gfs2/super.c +++ b/fs/gfs2/super.c @@ -169,8 +169,10 @@ 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)) {