This is a note to let you know that I've just added the patch titled
NVMe: Fix memory leak on retried commands
to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nvme-fix-memory-leak-on-retried-commands.patch
and it can be found in the queue-4.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>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: NVMe: Fix memory leak on retried commands
From: Keith Busch <keith.busch@xxxxxxxxx>
commit 0dfc70c33409afc232ef0b9ec210535dfbf9bc61 upstream.
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.
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/nvme-core.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -597,6 +597,7 @@ static void req_completion(struct nvme_q
struct nvme_iod *iod = ctx;
struct request *req = iod_get_private(iod);
struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req);
+ bool requeue = false;
u16 status = le16_to_cpup(&cqe->status) >> 1;
@@ -605,12 +606,13 @@ static void req_completion(struct nvme_q
&& (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) {
if (cmd_rq->ctx == CMD_CTX_CANCELLED)
@@ -631,7 +633,7 @@ static void req_completion(struct nvme_q
dev_warn(nvmeq->dev->dev,
"completing aborted command with status:%04x\n",
status);
-
+ 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);
@@ -644,7 +646,8 @@ static void req_completion(struct nvme_q
}
nvme_free_iod(nvmeq->dev, iod);
- blk_mq_complete_request(req);
+ if (likely(!requeue))
+ blk_mq_complete_request(req);
}
/* length is in bytes. gfp flags indicates whether we may sleep. */
Patches currently in stable-queue which might be from keith.busch@xxxxxxxxx are
queue-4.2/blk-mq-fix-use-after-free-in-blk_mq_free_tag_set.patch
queue-4.2/nvme-fix-memory-leak-on-retried-commands.patch
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