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 <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 0dfc70c33409afc232ef0b9ec210535dfbf9bc61 Mon Sep 17 00:00:00 2001
From: Keith Busch <keith.busch@xxxxxxxxx>
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: stable@xxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # 4.0.x-
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxx>
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. */
--
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