From c37366742baa2bb3225be507d283baef151c5f8a Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 12 Mar 2018 20:30:43 -0400 Subject: dm mpath: fix uninitialized 'pg_init_wait' waitqueue_head NULL pointer Initialize all the scsi_dh related 'struct multipath' members regardless of whether a scsi_dh is in use or not. The subtle (and fragile) SCSI-assuming legacy code clearly needs further decoupling from non-SCSI (and/or developer understanding). Fixes: 8d47e65948dd ("dm mpath: remove unnecessary NVMe branching in favor of scsi_dh checks") Reported-by: Bart Van Assche Signed-off-by: Mike Snitzer --- drivers/md/dm-mpath.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 3fde9e9faddd..87c404eebe9f 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -223,6 +223,16 @@ static int alloc_multipath_stage2(struct dm_target *ti, struct multipath *m) dm_table_set_type(ti->table, m->queue_mode); + /* + * Init fields that are only used when a scsi_dh is attached + * - must do this unconditionally (really doesn't hurt non-SCSI uses) + */ + set_bit(MPATHF_QUEUE_IO, &m->flags); + atomic_set(&m->pg_init_in_progress, 0); + atomic_set(&m->pg_init_count, 0); + m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; + init_waitqueue_head(&m->pg_init_wait); + return 0; } @@ -331,7 +341,6 @@ static void __switch_pg(struct multipath *m, struct priority_group *pg) set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); set_bit(MPATHF_QUEUE_IO, &m->flags); } else { - /* FIXME: not needed if no scsi_dh is attached */ clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); clear_bit(MPATHF_QUEUE_IO, &m->flags); } @@ -823,16 +832,6 @@ retain: */ kfree(m->hw_handler_name); m->hw_handler_name = attached_handler_name; - - /* - * Init fields that are only used when a scsi_dh is attached - */ - if (!test_and_set_bit(MPATHF_QUEUE_IO, &m->flags)) { - atomic_set(&m->pg_init_in_progress, 0); - atomic_set(&m->pg_init_count, 0); - m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; - init_waitqueue_head(&m->pg_init_wait); - } } } -- cgit v1.2.3-59-g8ed1b