Re: [RFC PATCH v5 03/27] nvme-tcp-offload: Add device scan implementation
From: Sagi Grimberg <sagi@grimberg.me>
Date: 2021-05-21 22:22:23
Also in:
netdev
On 5/19/21 4:13 AM, Shai Malin wrote:
quoted hunk ↗ jump to hunk
From: Dean Balandin <redacted> As part of create_ctrl(), it scans the registered devices and calls the claim_dev op on each of them, to find the first devices that matches the connection params. Once the correct devices is found (claim_dev returns true), we raise the refcnt of that device and return that device as the device to be used for ctrl currently being created. Acked-by: Igor Russkikh <redacted> Signed-off-by: Dean Balandin <redacted> Signed-off-by: Prabhakar Kushwaha <redacted> Signed-off-by: Omkar Kulkarni <redacted> Signed-off-by: Michal Kalderon <mkalderon@marvell.com> Signed-off-by: Ariel Elior <redacted> Signed-off-by: Shai Malin <redacted> --- drivers/nvme/host/tcp-offload.c | 94 +++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+)diff --git a/drivers/nvme/host/tcp-offload.c b/drivers/nvme/host/tcp-offload.c index 711232eba339..aa7cc239abf2 100644 --- a/drivers/nvme/host/tcp-offload.c +++ b/drivers/nvme/host/tcp-offload.c@@ -13,6 +13,11 @@ static LIST_HEAD(nvme_tcp_ofld_devices); static DECLARE_RWSEM(nvme_tcp_ofld_devices_rwsem); +static inline struct nvme_tcp_ofld_ctrl *to_tcp_ofld_ctrl(struct nvme_ctrl *nctrl) +{ + return container_of(nctrl, struct nvme_tcp_ofld_ctrl, nctrl); +} + /** * nvme_tcp_ofld_register_dev() - NVMeTCP Offload Library registration * function.@@ -98,6 +103,94 @@ void nvme_tcp_ofld_req_done(struct nvme_tcp_ofld_req *req, /* Placeholder - complete request with/without error */ } +struct nvme_tcp_ofld_dev * +nvme_tcp_ofld_lookup_dev(struct nvme_tcp_ofld_ctrl *ctrl) +{ + struct nvme_tcp_ofld_dev *dev; + + down_read(&nvme_tcp_ofld_devices_rwsem); + list_for_each_entry(dev, &nvme_tcp_ofld_devices, entry) { + if (dev->ops->claim_dev(dev, &ctrl->conn_params)) { + /* Increase driver refcnt */ + if (!try_module_get(dev->ops->module)) {
This means that every controller will take a long-lived reference on the module? Why?
+ pr_err("try_module_get failed\n");
+ dev = NULL;
+ }
+
+ goto out;
+ }
+ }
+
+ dev = NULL;
+out:
+ up_read(&nvme_tcp_ofld_devices_rwsem);
+
+ return dev;
+}
+
+static int nvme_tcp_ofld_setup_ctrl(struct nvme_ctrl *nctrl, bool new)
+{
+ /* Placeholder - validates inputs and creates admin and IO queues */
+
+ return 0;
+}
+
+static struct nvme_ctrl *
+nvme_tcp_ofld_create_ctrl(struct device *ndev, struct nvmf_ctrl_options *opts)
+{
+ struct nvme_tcp_ofld_ctrl *ctrl;
+ struct nvme_tcp_ofld_dev *dev;
+ struct nvme_ctrl *nctrl;
+ int rc = 0;
+
+ ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+ if (!ctrl)
+ return ERR_PTR(-ENOMEM);
+
+ nctrl = &ctrl->nctrl;
+
+ /* Init nvme_tcp_ofld_ctrl and nvme_ctrl params based on received opts */
+
+ /* Find device that can reach the dest addr */
+ dev = nvme_tcp_ofld_lookup_dev(ctrl);
+ if (!dev) {
+ pr_info("no device found for addr %s:%s.\n",
+ opts->traddr, opts->trsvcid);
+ rc = -EINVAL;
+ goto out_free_ctrl;
+ }
+
+ ctrl->dev = dev;
+
+ if (ctrl->dev->ops->max_hw_sectors)
+ nctrl->max_hw_sectors = ctrl->dev->ops->max_hw_sectors;
+ if (ctrl->dev->ops->max_segments)
+ nctrl->max_segments = ctrl->dev->ops->max_segments;
+
+ /* Init queues */
+
+ /* Call nvme_init_ctrl */
+
+ rc = ctrl->dev->ops->setup_ctrl(ctrl, true);
+ if (rc)
+ goto out_module_put;goto module_put without an explicit module_get is confusing.
+ + rc = nvme_tcp_ofld_setup_ctrl(nctrl, true); + if (rc) + goto out_uninit_ctrl;
ops->setup_ctrl and then call to nvme_tcp_ofld_setup_ctrl? Looks weird, why are these separated?
quoted hunk ↗ jump to hunk
+ + return nctrl; + +out_uninit_ctrl: + ctrl->dev->ops->release_ctrl(ctrl); +out_module_put: + module_put(dev->ops->module); +out_free_ctrl: + kfree(ctrl); + + return ERR_PTR(rc); +} + static struct nvmf_transport_ops nvme_tcp_ofld_transport = { .name = "tcp_offload", .module = THIS_MODULE,@@ -107,6 +200,7 @@ static struct nvmf_transport_ops nvme_tcp_ofld_transport = { NVMF_OPT_RECONNECT_DELAY | NVMF_OPT_HDR_DIGEST | NVMF_OPT_DATA_DIGEST | NVMF_OPT_NR_POLL_QUEUES | NVMF_OPT_TOS, + .create_ctrl = nvme_tcp_ofld_create_ctrl, }; static int __init nvme_tcp_ofld_init_module(void)
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