4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Sagi Grimberg <[email protected]> [ Upstream commit d11ea004a458b982e19b188c386e25a9b66ec446 ] percpu_ref_kill is not enough to prevent subsequent percpu_ref_tryget_live from failing. Hence call perfcpu_ref_kill_confirm to make it safe. Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Sagi Grimberg <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/nvme/target/core.c | 11 ++++++++++- drivers/nvme/target/nvmet.h | 1 + 2 files changed, 11 insertions(+), 1 deletion(-) --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -422,6 +422,13 @@ void nvmet_sq_setup(struct nvmet_ctrl *c ctrl->sqs[qid] = sq; } +static void nvmet_confirm_sq(struct percpu_ref *ref) +{ + struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref); + + complete(&sq->confirm_done); +} + void nvmet_sq_destroy(struct nvmet_sq *sq) { /* @@ -430,7 +437,8 @@ void nvmet_sq_destroy(struct nvmet_sq *s */ if (sq->ctrl && sq->ctrl->sqs && sq->ctrl->sqs[0] == sq) nvmet_async_events_free(sq->ctrl); - percpu_ref_kill(&sq->ref); + percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq); + wait_for_completion(&sq->confirm_done); wait_for_completion(&sq->free_done); percpu_ref_exit(&sq->ref); @@ -458,6 +466,7 @@ int nvmet_sq_init(struct nvmet_sq *sq) return ret; } init_completion(&sq->free_done); + init_completion(&sq->confirm_done); return 0; } --- a/drivers/nvme/target/nvmet.h +++ b/drivers/nvme/target/nvmet.h @@ -73,6 +73,7 @@ struct nvmet_sq { u16 qid; u16 size; struct completion free_done; + struct completion confirm_done; }; /**
