4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sagi Grimberg <sagi@xxxxxxxxxxx>
[ 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 <hch@xxxxxx>
Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
};
/**