From: Yu Kuai <yukuai3@xxxxxxxxxx> [ Upstream commit b721e7885eb242aa2459ee66bb42ceef1bcf0f0c ] 'active_io' used to be initialized while the array is running, and 'mddev->pers' is set while the array is running as well. Hence caller must hold 'reconfig_mutex' and guarantee 'mddev->pers' is set before calling mddev_suspend(). Now that 'active_io' is initialized when mddev is allocated, such restriction doesn't exist anymore. In the meantime, follow up patches will refactor mddev_suspend(), hence add checking for 'mddev->pers' to prevent null-ptr-deref. Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> Signed-off-by: Song Liu <song@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230825030956.1527023-4-yukuai1@xxxxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/md/md.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 78d51dddf3a00..34b7196d9634c 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -449,7 +449,7 @@ void mddev_suspend(struct mddev *mddev) set_bit(MD_ALLOW_SB_UPDATE, &mddev->flags); percpu_ref_kill(&mddev->active_io); - if (mddev->pers->prepare_suspend) + if (mddev->pers && mddev->pers->prepare_suspend) mddev->pers->prepare_suspend(mddev); wait_event(mddev->sb_wait, percpu_ref_is_zero(&mddev->active_io)); -- 2.42.0
