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nvme-rdma: serialize controller teardown sequences

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In the timeout handler we may need to complete a request because the
request that timed out may be an I/O that is a part of a serial sequence
of controller teardown or initialization. In order to complete the
request, we need to fence any other context that may compete with us
and complete the request that is timing out.

In this case, we could have a potential double completion in case
a hard-irq or a different competing context triggered error recovery
and is running inflight request cancellation concurrently with the
timeout handler.

Protect using a ctrl teardown_lock to serialize contexts that may
complete a cancelled request due to error recovery or a reset.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
This commit is contained in:
Sagi Grimberg 2020-08-05 18:13:58 -07:00
parent e5c01f4f7f
commit 5110f40241
1 changed files with 6 additions and 0 deletions
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6
drivers/nvme/host/rdma.c
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@ -122,6 +122,7 @@ struct nvme_rdma_ctrl {
struct sockaddr_storage src_addr;
struct nvme_ctrl ctrl;
struct mutex teardown_lock;
bool use_inline_data;
u32 io_queues[HCTX_MAX_TYPES];
};
@ -997,6 +998,7 @@ out_free_io_queues:
static void nvme_rdma_teardown_admin_queue(struct nvme_rdma_ctrl *ctrl,
bool remove)
{
mutex_lock(&ctrl->teardown_lock);
blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
nvme_rdma_stop_queue(&ctrl->queues[0]);
if (ctrl->ctrl.admin_tagset) {
@ -1007,11 +1009,13 @@ static void nvme_rdma_teardown_admin_queue(struct nvme_rdma_ctrl *ctrl,
if (remove)
blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
nvme_rdma_destroy_admin_queue(ctrl, remove);
mutex_unlock(&ctrl->teardown_lock);
}
static void nvme_rdma_teardown_io_queues(struct nvme_rdma_ctrl *ctrl,
bool remove)
{
mutex_lock(&ctrl->teardown_lock);
if (ctrl->ctrl.queue_count > 1) {
nvme_start_freeze(&ctrl->ctrl);
nvme_stop_queues(&ctrl->ctrl);
@ -1025,6 +1029,7 @@ static void nvme_rdma_teardown_io_queues(struct nvme_rdma_ctrl *ctrl,
nvme_start_queues(&ctrl->ctrl);
nvme_rdma_destroy_io_queues(ctrl, remove);
}
mutex_unlock(&ctrl->teardown_lock);
}
static void nvme_rdma_free_ctrl(struct nvme_ctrl *nctrl)
@ -2278,6 +2283,7 @@ static struct nvme_ctrl *nvme_rdma_create_ctrl(struct device *dev,
return ERR_PTR(-ENOMEM);
ctrl->ctrl.opts = opts;
INIT_LIST_HEAD(&ctrl->list);
mutex_init(&ctrl->teardown_lock);
if (!(opts->mask & NVMF_OPT_TRSVCID)) {
opts->trsvcid =