The patch below does not apply to the 4.2-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 0dfc70c33409afc232ef0b9ec210535dfbf9bc61 Mon Sep 17 00:00:00 2001 From: Keith Busch <[email protected]> Date: Thu, 15 Oct 2015 13:38:48 -0600 Subject: [PATCH] NVMe: Fix memory leak on retried commands Resources are reallocated for requeued commands, so unmap and release the iod for the failed command. It's a pretty bad memory leak and causes a kernel hang if you remove a drive because of a busy dma pool. You'll get messages spewing like this: nvme 0000:xx:xx.x: dma_pool_destroy prp list 256, ffff880420dec000 busy and lock up pci and the driver since removal never completes while holding a lock. Cc: [email protected] Cc: <[email protected]> # 4.0.x- Signed-off-by: Keith Busch <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Jens Axboe <[email protected]> diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index 84e4a8088386..ccc0c1f93daa 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -604,6 +604,7 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx, struct request *req = iod_get_private(iod); struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req); u16 status = le16_to_cpup(&cqe->status) >> 1; + bool requeue = false; int error = 0; if (unlikely(status)) { @@ -611,12 +612,13 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx, && (jiffies - req->start_time) < req->timeout) { unsigned long flags; + requeue = true; blk_mq_requeue_request(req); spin_lock_irqsave(req->q->queue_lock, flags); if (!blk_queue_stopped(req->q)) blk_mq_kick_requeue_list(req->q); spin_unlock_irqrestore(req->q->queue_lock, flags); - return; + goto release_iod; } if (req->cmd_type == REQ_TYPE_DRV_PRIV) { @@ -639,6 +641,7 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx, "completing aborted command with status:%04x\n", error); +release_iod: if (iod->nents) { dma_unmap_sg(nvmeq->dev->dev, iod->sg, iod->nents, rq_data_dir(req) ? DMA_TO_DEVICE : DMA_FROM_DEVICE); @@ -651,7 +654,8 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx, } nvme_free_iod(nvmeq->dev, iod); - blk_mq_complete_request(req, error); + if (likely(!requeue)) + blk_mq_complete_request(req, error); } /* length is in bytes. gfp flags indicates whether we may sleep. */ -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
