RE: [EXTERNAL] [PATCH 7/7] cbd: add related sysfs files in transport register

[Bharat Bhushan]

> -----Original Message-----
> From: Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx>
> Sent: Monday, April 22, 2024 12:46 PM
> To: dan.j.williams@xxxxxxxxx; axboe@xxxxxxxxx
> Cc: linux-block@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-
> cxl@xxxxxxxxxxxxxxx; Dongsheng Yang <dongsheng.yang.linux@xxxxxxxxx>
> Subject: [EXTERNAL] [PATCH 7/7] cbd: add related sysfs files in transport
> register
> 
> Prioritize security for external emails: Confirm sender and content safety
> before clicking links or opening attachments
> 
> ----------------------------------------------------------------------
> From: Dongsheng Yang <dongsheng.yang.linux@xxxxxxxxx>
> 
> When a transport is registered, a corresponding file is created for each
> area within the transport in the sysfs, including "cbd_hosts",
> "cbd_backends", "cbd_blkdevs", and "cbd_channels".
> 
> Through these sysfs files, we can examine the information of each entity
> and thereby understand the relationships between them. This allows us to
> further understand the current operational status of the transport.
> 
> For example, by examining "cbd_hosts", we can find all the hosts
> currently using the transport. We can also determine which host each
> backend is running on by looking at the "host_id" in "cbd_backends".
> Similarly, by examining "cbd_blkdevs", we can determine which host each
> blkdev is running on, and through the "mapped_id", we can know the name
> of the cbd device to which the blkdev is mapped. Additionally, by
> looking at "cbd_channels", we can determine which blkdev and backend are
> connected through each channel by examining the "blkdev_id" and
> "backend_id".
> 
> Signed-off-by: Dongsheng Yang <dongsheng.yang.linux@xxxxxxxxx>
> ---
>  drivers/block/cbd/cbd_transport.c | 101
> +++++++++++++++++++++++++++++-
>  1 file changed, 100 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/block/cbd/cbd_transport.c
> b/drivers/block/cbd/cbd_transport.c
> index 75b9d34218fc..0e917d72b209 100644
> --- a/drivers/block/cbd/cbd_transport.c
> +++ b/drivers/block/cbd/cbd_transport.c
> @@ -1,8 +1,91 @@
>  #include <linux/pfn_t.h>
> -
>  #include "cbd_internal.h"
> 
>  #define CBDT_OBJ(OBJ, OBJ_SIZE)
> 		\
> +extern struct device_type cbd_##OBJ##_type;
> 	\
> +extern struct device_type cbd_##OBJ##s_type;
> 	\
> +
> 	\
> +static int cbd_##OBJ##s_init(struct cbd_transport *cbdt)
> 	\
> +{
> 	\
> +	struct cbd_##OBJ##s_device *devs;
> 	\
> +	struct cbd_##OBJ##_device *cbd_dev;
> 	\
> +	struct device *dev;
> 	\
> +	int i;
> 	\
> +	int ret;								\
> +
> 	\
> +	u32 memsize = struct_size(devs, OBJ##_devs,
> 	\
> +			cbdt->transport_info->OBJ##_num);
> 	\
> +	devs = kzalloc(memsize, GFP_KERNEL);
> 	\
> +	if (!devs) {
> 	\
> +	    return -ENOMEM;
> 	\
> +	}

Do not need "{ } " here 

> 	\
> +
> 	\
> +	dev = &devs->OBJ##s_dev;
> 	\
> +	device_initialize(dev);
> 	\
> +	device_set_pm_not_required(dev);
> 	\
> +	dev_set_name(dev, "cbd_" #OBJ "s");
> 	\
> +	dev->parent = &cbdt->device;
> 	\
> +	dev->type = &cbd_##OBJ##s_type;
> 		\
> +	ret = device_add(dev);
> 	\
> +	if (ret) {								\
> +		goto devs_free;
> 	\
> +	}

Do not need "{ } " here

Thanks
-Bharat

> 	\
> +
> 	\
> +	for (i = 0; i < cbdt->transport_info->OBJ##_num; i++) {
> 	\
> +		cbd_dev = &devs->OBJ##_devs[i];
> 		\
> +		dev = &cbd_dev->dev;
> 	\
> +
> 	\
> +		cbd_dev->cbdt = cbdt;
> 	\
> +		cbd_dev->OBJ##_info = cbdt_get_##OBJ##_info(cbdt, i);
> 		\
> +		device_initialize(dev);
> 	\
> +		device_set_pm_not_required(dev);
> 	\
> +		dev_set_name(dev, #OBJ "%u", i);
> 	\
> +		dev->parent = &devs->OBJ##s_dev;
> 	\
> +		dev->type = &cbd_##OBJ##_type;
> 		\
> +
> 	\
> +		ret = device_add(dev);
> 	\
> +		if (ret) {							\
> +			i--;
> 	\
> +			goto del_device;
> 	\
> +		}
> 	\
> +	}
> 	\
> +	cbdt->cbd_##OBJ##s_dev = devs;
> 		\
> +
> 	\
> +    	return 0;
> 	\
> +del_device:
> 	\
> +	for (; i >= 0; i--) {
> 	\
> +		cbd_dev = &devs->OBJ##_devs[i];
> 		\
> +		dev = &cbd_dev->dev;
> 	\
> +		device_del(dev);
> 	\
> +	}
> 	\
> +devs_free:
> 	\
> +	kfree(devs);
> 	\
> +	return ret;
> 	\
> +}
> 	\
> +
> 	\
> +static void cbd_##OBJ##s_exit(struct cbd_transport *cbdt)
> 	\
> +{
> 	\
> +	struct cbd_##OBJ##s_device *devs = cbdt->cbd_##OBJ##s_dev;
> 	\
> +	struct device *dev;
> 	\
> +	int i;
> 	\
> +
> 	\
> +	if (!devs)
> 	\
> +		return;
> 	\
> +
> 	\
> +	for (i = 0; i < cbdt->transport_info->OBJ##_num; i++) {
> 	\
> +		struct cbd_##OBJ##_device *cbd_dev = &devs-
> >OBJ##_devs[i];	\
> +		dev = &cbd_dev->dev;
> 	\
> +
> 	\
> +		device_del(dev);
> 	\
> +	}
> 	\
> +
> 	\
> +	device_del(&devs->OBJ##s_dev);
> 		\
> +
> 	\
> +	kfree(devs);
> 	\
> +	cbdt->cbd_##OBJ##s_dev = NULL;
> 		\
> +
> 	\
> +	return;
> 	\
> +}
> 	\
> 
> 	\
>  static inline struct cbd_##OBJ##_info
> 	\
>  *__get_##OBJ##_info(struct cbd_transport *cbdt, u32 id)
> 		\
> @@ -588,6 +671,11 @@ int cbdt_unregister(u32 tid)
>  	}
>  	mutex_unlock(&cbdt->lock);
> 
> +	cbd_blkdevs_exit(cbdt);
> +	cbd_channels_exit(cbdt);
> +	cbd_backends_exit(cbdt);
> +	cbd_hosts_exit(cbdt);
> +
>  	cbd_host_unregister(cbdt);
>  	device_unregister(&cbdt->device);
>  	cbdt_dax_release(cbdt);
> @@ -647,9 +735,20 @@ int cbdt_register(struct cbdt_register_options
> *opts)
>  		goto dev_unregister;
>  	}
> 
> +	if (cbd_hosts_init(cbdt) || cbd_backends_init(cbdt) ||
> +	    cbd_channels_init(cbdt) || cbd_blkdevs_init(cbdt)) {
> +		ret = -ENOMEM;
> +		goto devs_exit;
> +	}
> +
>  	return 0;
> 
>  devs_exit:
> +	cbd_blkdevs_exit(cbdt);
> +	cbd_channels_exit(cbdt);
> +	cbd_backends_exit(cbdt);
> +	cbd_hosts_exit(cbdt);
> +
>  	cbd_host_unregister(cbdt);
>  dev_unregister:
>  	device_unregister(&cbdt->device);
> --
> 2.34.1
>