nvmet: confirm sq percpu has scheduled and switched to atomic

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 <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Sagi Grimberg 2017-03-06 18:46:20 +02:00 committed by Jens Axboe
parent 6ecda70ea9
commit 427242ce99
2 changed files with 11 additions and 1 deletions

View File

@ -425,6 +425,13 @@ void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq,
ctrl->sqs[qid] = sq; 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) void nvmet_sq_destroy(struct nvmet_sq *sq)
{ {
/* /*
@ -433,7 +440,8 @@ void nvmet_sq_destroy(struct nvmet_sq *sq)
*/ */
if (sq->ctrl && sq->ctrl->sqs && sq->ctrl->sqs[0] == sq) if (sq->ctrl && sq->ctrl->sqs && sq->ctrl->sqs[0] == sq)
nvmet_async_events_free(sq->ctrl); 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); wait_for_completion(&sq->free_done);
percpu_ref_exit(&sq->ref); percpu_ref_exit(&sq->ref);
@ -461,6 +469,7 @@ int nvmet_sq_init(struct nvmet_sq *sq)
return ret; return ret;
} }
init_completion(&sq->free_done); init_completion(&sq->free_done);
init_completion(&sq->confirm_done);
return 0; return 0;
} }

View File

@ -73,6 +73,7 @@ struct nvmet_sq {
u16 qid; u16 qid;
u16 size; u16 size;
struct completion free_done; struct completion free_done;
struct completion confirm_done;
}; };
/** /**