[PATCH] nvme: Don't suspend admin queue that wasn't created

[PATCH] nvme: Don't suspend admin queue that wasn't created

[Gabriel Krisman Bertazi]

This fixes a regression in my previous commit c21377f8366c ("nvme:
Suspend all queues before deletion"), which provoked an Oops in the
removal path when removing a device that became IO incapable very early
at probe (i.e. after a failed EEH recovery).

Turns out, if the error occurred very early at the probe path, before
even configuring the admin queue, we might try to suspend the
uninitialized admin queue, accessing bad memory.

Fixes: c21377f8366c ("nvme: Suspend all queues before deletion")
Signed-off-by: Gabriel Krisman Bertazi <krisman at linux.vnet.ibm.com>
---
 drivers/nvme/host/pci.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 8dcf5a960951..be84a84a40f7 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1693,7 +1693,12 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 		nvme_suspend_queue(dev->queues[i]);
 
 	if (csts & NVME_CSTS_CFS || !(csts & NVME_CSTS_RDY)) {
-		nvme_suspend_queue(dev->queues[0]);
+		/* A device might become IO incapable very soon during
+		 * probe, before the admin queue is configured. Thus,
+		 * queue_count can be 0 here.
+		 */
+		if (dev->queue_count)
+			nvme_suspend_queue(dev->queues[0]);
 	} else {
 		nvme_disable_io_queues(dev);
 		nvme_disable_admin_queue(dev, shutdown);
-- 
2.7.4

[PATCH] nvme: Don't suspend admin queue that wasn't created

[J Freyensee]

On Tue, 2016-09-06@17:39 -0300, Gabriel Krisman Bertazi wrote:
> This fixes a regression in my previous commit c21377f8366c ("nvme:
> Suspend all queues before deletion"), which provoked an Oops in the
> removal path when removing a device that became IO incapable very
> early
> at probe (i.e. after a failed EEH recovery).
> 
> Turns out, if the error occurred very early at the probe path, before
> even configuring the admin queue, we might try to suspend the
> uninitialized admin queue, accessing bad memory.
> 
> Fixes: c21377f8366c ("nvme: Suspend all queues before deletion")
> Signed-off-by: Gabriel Krisman Bertazi <krisman at linux.vnet.ibm.com>
> ---
> ?drivers/nvme/host/pci.c | 7 ++++++-
> ?1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 8dcf5a960951..be84a84a40f7 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -1693,7 +1693,12 @@ static void nvme_dev_disable(struct nvme_dev
> *dev, bool shutdown)
> ?		nvme_suspend_queue(dev->queues[i]);
> ?
> ?	if (csts & NVME_CSTS_CFS || !(csts & NVME_CSTS_RDY)) {
> -		nvme_suspend_queue(dev->queues[0]);
> +		/* A device might become IO incapable very soon
> during
> +		?* probe, before the admin queue is configured.
> Thus,
> +		?* queue_count can be 0 here.
> +		?*/
> +		if (dev->queue_count)
> +			nvme_suspend_queue(dev->queues[0]);

Looks like ?a good fix to me.

Reviewed-by: Jay Freyensee <james_p_freyensee at linux.intel.com>

[PATCH] nvme: Don't suspend admin queue that wasn't created

[Jens Axboe]

On 09/06/2016 02:39 PM, Gabriel Krisman Bertazi wrote:
> This fixes a regression in my previous commit c21377f8366c ("nvme:
> Suspend all queues before deletion"), which provoked an Oops in the
> removal path when removing a device that became IO incapable very early
> at probe (i.e. after a failed EEH recovery).
>
> Turns out, if the error occurred very early at the probe path, before
> even configuring the admin queue, we might try to suspend the
> uninitialized admin queue, accessing bad memory.
>
> Fixes: c21377f8366c ("nvme: Suspend all queues before deletion")
> Signed-off-by: Gabriel Krisman Bertazi <krisman at linux.vnet.ibm.com>

Applied for 4.8, thanks.

-- 
Jens Axboe