The current blk_mq_quiesce_queue() and blk_mq_unquiesce_queue() always
stops and starts the queue unconditionally. And there can be concurrent
quiesce/unquiesce coming from different unrelated code paths, so
unquiesce may come unexpectedly and start queue too early.
Prepare for supporting concurrent quiesce/unquiesce from multiple
contexts, so that we can address the above issue.
NVMe has very complicated quiesce/unquiesce use pattern, add one atomic
bit for makeiing sure that blk-mq quiece/unquiesce is always called in
pair.
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
drivers/nvme/host/core.c | 12 ++++++++----
drivers/nvme/host/nvme.h | 2 ++
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 23fb746a8970..4391760e2e9a 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4452,12 +4452,14 @@ EXPORT_SYMBOL_GPL(nvme_init_ctrl);
static void nvme_start_ns_queue(struct nvme_ns *ns)
{
- blk_mq_unquiesce_queue(ns->queue);
+ if (test_and_clear_bit(NVME_NS_STOPPED, &ns->flags))
+ blk_mq_unquiesce_queue(ns->queue);
}
static void nvme_stop_ns_queue(struct nvme_ns *ns)
{
- blk_mq_quiesce_queue(ns->queue);
+ if (!test_and_set_bit(NVME_NS_STOPPED, &ns->flags))
+ blk_mq_quiesce_queue(ns->queue);
}
/*
@@ -4575,13 +4577,15 @@ EXPORT_SYMBOL_GPL(nvme_start_queues);
void nvme_stop_admin_queue(struct nvme_ctrl *ctrl)
{
- blk_mq_quiesce_queue(ctrl->admin_q);
+ if (!test_and_set_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->flags))
+ blk_mq_quiesce_queue(ctrl->admin_q);
}
EXPORT_SYMBOL_GPL(nvme_stop_admin_queue);
void nvme_start_admin_queue(struct nvme_ctrl *ctrl)
{
- blk_mq_unquiesce_queue(ctrl->admin_q);
+ if (test_and_clear_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->flags))
+ blk_mq_unquiesce_queue(ctrl->admin_q);
}
EXPORT_SYMBOL_GPL(nvme_start_admin_queue);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 47877a5f1515..0fa6fa22f088 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -336,6 +336,7 @@ struct nvme_ctrl {
int nr_reconnects;
unsigned long flags;
#define NVME_CTRL_FAILFAST_EXPIRED 0
+#define NVME_CTRL_ADMIN_Q_STOPPED 1
struct nvmf_ctrl_options *opts;
struct page *discard_page;
@@ -457,6 +458,7 @@ struct nvme_ns {
#define NVME_NS_ANA_PENDING 2
#define NVME_NS_FORCE_RO 3
#define NVME_NS_READY 4
+#define NVME_NS_STOPPED 5
struct cdev cdev;
struct device cdev_device;
--
2.31.1
