Commit b224726d authored by Balbir Singh's avatar Balbir Singh Committed by Sagi Grimberg

nvme-pci: Fix a race in controller removal

User space programs like udevd may try to read to partitions at the
same time the driver detects a namespace is unusable, and may deadlock
if revalidate_disk() is called while such a process is waiting to
enter the frozen queue. On detecting a dead namespace, move the disk
revalidate after unblocking dispatchers that may be holding bd_butex.

changelog Suggested-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: default avatarBalbir Singh <sblbir@amzn.com>
Reviewed-by: default avatarKeith Busch <kbusch@kernel.org>
Signed-off-by: default avatarSagi Grimberg <sagi@grimberg.me>
parent 0ec64895
...@@ -102,10 +102,13 @@ static void nvme_set_queue_dying(struct nvme_ns *ns) ...@@ -102,10 +102,13 @@ static void nvme_set_queue_dying(struct nvme_ns *ns)
*/ */
if (!ns->disk || test_and_set_bit(NVME_NS_DEAD, &ns->flags)) if (!ns->disk || test_and_set_bit(NVME_NS_DEAD, &ns->flags))
return; return;
revalidate_disk(ns->disk);
blk_set_queue_dying(ns->queue); blk_set_queue_dying(ns->queue);
/* Forcibly unquiesce queues to avoid blocking dispatch */ /* Forcibly unquiesce queues to avoid blocking dispatch */
blk_mq_unquiesce_queue(ns->queue); blk_mq_unquiesce_queue(ns->queue);
/*
* Revalidate after unblocking dispatchers that may be holding bd_butex
*/
revalidate_disk(ns->disk);
} }
static void nvme_queue_scan(struct nvme_ctrl *ctrl) static void nvme_queue_scan(struct nvme_ctrl *ctrl)
......
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