From: Keith Busch <kbusch@xxxxxxxxxx>
The cdev only services passthrough commands which don't merge, track
stats, or need accounting. Give it a special request queue with all
these options cleared so that we're not adding overhead for it.
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
---
drivers/nvme/host/core.c | 29 +++++++++++++++++++++++++----
drivers/nvme/host/ioctl.c | 4 ++--
drivers/nvme/host/nvme.h | 1 +
3 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 0f1cb6f418182..5bb05c91d866d 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4071,21 +4071,39 @@ static const struct file_operations nvme_ns_chr_fops = {
static int nvme_add_ns_cdev(struct nvme_ns *ns)
{
+ struct nvme_ctrl *ctrl = ns->ctrl;
+ struct request_queue *q;
int ret;
- ns->cdev_device.parent = ns->ctrl->device;
+ ns->cdev_device.parent = ctrl->device;
ret = dev_set_name(&ns->cdev_device, "ng%dn%d",
- ns->ctrl->instance, ns->head->instance);
+ ctrl->instance, ns->head->instance);
if (ret)
return ret;
ret = nvme_cdev_add(&ns->cdev, &ns->cdev_device, &nvme_ns_chr_fops,
- ns->ctrl->ops->module);
+ ctrl->ops->module);
if (ret)
goto out_free_name;
+ q = blk_mq_init_queue(ctrl->tagset);
+ if (IS_ERR(q)) {
+ ret = PTR_ERR(q);
+ goto out_free_cdev;
+ }
+
+ blk_queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
+ blk_queue_flag_clear(QUEUE_FLAG_STATS, q);
+ blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
+ q->queuedata = ns;
+ ns->cdev_queue = q;
+
return 0;
+out_free_cdev:
+ cdev_device_del(&ns->cdev, &ns->cdev_device);
+ return ret;
+
out_free_name:
kfree_const(ns->cdev_device.kobj.name);
return ret;
@@ -4399,8 +4417,11 @@ static void nvme_ns_remove(struct nvme_ns *ns)
/* guarantee not available in head->list */
synchronize_srcu(&ns->head->srcu);
- if (!nvme_ns_head_multipath(ns->head))
+ if (!nvme_ns_head_multipath(ns->head)) {
+ blk_mq_destroy_queue(ns->cdev_queue);
+ blk_put_queue(ns->cdev_queue);
nvme_cdev_del(&ns->cdev, &ns->cdev_device);
+ }
del_gendisk(ns->disk);
down_write(&ns->ctrl->namespaces_rwsem);
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 3804e5205b42b..bf4fcb5d270e9 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -553,7 +553,7 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
{
struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
const struct nvme_uring_cmd *cmd = ioucmd->cmd;
- struct request_queue *q = ns ? ns->queue : ctrl->admin_q;
+ struct request_queue *q = ns ? ns->cdev_queue : ctrl->admin_q;
struct nvme_uring_data d;
struct nvme_command c;
struct request *req;
@@ -791,7 +791,7 @@ int nvme_ns_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd,
bio = READ_ONCE(ioucmd->cookie);
ns = container_of(file_inode(ioucmd->file)->i_cdev,
struct nvme_ns, cdev);
- q = ns->queue;
+ q = ns->cdev_queue;
if (test_bit(QUEUE_FLAG_POLL, &q->queue_flags) && bio && bio->bi_bdev)
ret = bio_poll(bio, iob, poll_flags);
rcu_read_unlock();
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index bf46f122e9e1e..d837c118f4f18 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -495,6 +495,7 @@ struct nvme_ns {
struct cdev cdev;
struct device cdev_device;
+ struct request_queue *cdev_queue;
struct nvme_fault_inject fault_inject;
--
2.34.1
