| Message ID | 163294293832.914350.10326422026738506152.stgit@djiang5-desk3.ch.intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 85f604af9c83a4656b1d07bec73298c3ba7d7c1e |
| Headers | show |
| Series | dmaengine: idxd: move out percpu_ref_exit() to ensure it's outside submission | expand |
On 29-09-21, 12:15, Dave Jiang wrote: > percpu_ref_tryget_live() is safe to call as long as ref is between init and > exit according to the function comment. Move percpu_ref_exit() so it is > called after the dma channel is no longer valid to ensure this holds true. Applied, thanks
diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c index 83a5ff2ecf2a..cbbfa17d8d11 100644 --- a/drivers/dma/idxd/device.c +++ b/drivers/dma/idxd/device.c @@ -427,7 +427,6 @@ void idxd_wq_quiesce(struct idxd_wq *wq) { percpu_ref_kill(&wq->wq_active); wait_for_completion(&wq->wq_dead); - percpu_ref_exit(&wq->wq_active); } /* Device control bits */ diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c index e0f056c1d1f5..b90b085d18cf 100644 --- a/drivers/dma/idxd/dma.c +++ b/drivers/dma/idxd/dma.c @@ -311,6 +311,7 @@ static int idxd_dmaengine_drv_probe(struct idxd_dev *idxd_dev) err_dma: idxd_wq_quiesce(wq); + percpu_ref_exit(&wq->wq_active); err_ref: idxd_wq_free_resources(wq); err_res_alloc: @@ -329,6 +330,7 @@ static void idxd_dmaengine_drv_remove(struct idxd_dev *idxd_dev) idxd_wq_quiesce(wq); idxd_unregister_dma_channel(wq); __drv_disable_wq(wq); + percpu_ref_exit(&wq->wq_active); idxd_wq_free_resources(wq); wq->type = IDXD_WQT_NONE; mutex_unlock(&wq->wq_lock);
percpu_ref_tryget_live() is safe to call as long as ref is between init and exit according to the function comment. Move percpu_ref_exit() so it is called after the dma channel is no longer valid to ensure this holds true. Fixes: 93a40a6d7428 ("dmaengine: idxd: add percpu_ref to descriptor submission path") Suggested-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> --- drivers/dma/idxd/device.c | 1 - drivers/dma/idxd/dma.c | 2 ++ 2 files changed, 2 insertions(+), 1 deletion(-)