Commit 3dbbca75 authored by Muneendra Kumar's avatar Muneendra Kumar Committed by Martin K. Petersen
Browse files

scsi: nvme: Added a new sysfs attribute appid_store 

Add a new sysfs attribute, appid_store, which can be used to set the
application identifier in the blkcg associated with a cgroup id.

Below is the interface provided to set the app_id:

  echo "<cgroupid>:<appid>" >> /sys/class/fc/fc_udev_device/appid_store

  echo "457E:100000109b521d27" >> /sys/class/fc/fc_udev_device/appid_store

Link: https://lore.kernel.org/r/20210608043556.274139-4-muneendra.kumar@broadcom.com


Reviewed-by: default avatarHimanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarMuneendra Kumar <muneendra.kumar@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent d2bcbeab

drivers/nvme/host/fc.c

+71 −1
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ 
#include <uapi/scsi/fc/fc_els.h>

#include <linux/delay.h>

#include <linux/overflow.h>



#include <linux/blk-cgroup.h>

#include "nvme.h"

#include "fabrics.h"

#include <linux/nvme-fc-driver.h>
@@ -3787,10 +3787,80 @@ static ssize_t nvme_fc_nvme_discovery_store(struct device *dev, 


	return count;

}



/* Parse the cgroup id from a buf and return the length of cgrpid */

static int fc_parse_cgrpid(const char *buf, u64 *id)

{

	char cgrp_id[16+1];

	int cgrpid_len, j;



	memset(cgrp_id, 0x0, sizeof(cgrp_id));

	for (cgrpid_len = 0, j = 0; cgrpid_len < 17; cgrpid_len++) {

		if (buf[cgrpid_len] != ':')

			cgrp_id[cgrpid_len] = buf[cgrpid_len];

		else {

			j = 1;

			break;

		}

	}

	if (!j)

		return -EINVAL;

	if (kstrtou64(cgrp_id, 16, id) < 0)

		return -EINVAL;

	return cgrpid_len;

}



/*

 * fc_update_appid: Parse and update the appid in the blkcg associated with

 * cgroupid.

 * @buf: buf contains both cgrpid and appid info

 * @count: size of the buffer

 */

static int fc_update_appid(const char *buf, size_t count)

{

	u64 cgrp_id;

	int appid_len = 0;

	int cgrpid_len = 0;

	char app_id[FC_APPID_LEN];

	int ret = 0;



	if (buf[count-1] == '\n')

		count--;



	if ((count > (16+1+FC_APPID_LEN)) || (!strchr(buf, ':')))

		return -EINVAL;



	cgrpid_len = fc_parse_cgrpid(buf, &cgrp_id);

	if (cgrpid_len < 0)

		return -EINVAL;

	appid_len = count - cgrpid_len - 1;

	if (appid_len > FC_APPID_LEN)

		return -EINVAL;



	memset(app_id, 0x0, sizeof(app_id));

	memcpy(app_id, &buf[cgrpid_len+1], appid_len);

	ret = blkcg_set_fc_appid(app_id, cgrp_id, sizeof(app_id));

	if (ret < 0)

		return ret;

	return count;

}



static ssize_t fc_appid_store(struct device *dev,

		struct device_attribute *attr, const char *buf, size_t count)

{

	int ret  = 0;



	ret = fc_update_appid(buf, count);

	if (ret < 0)

		return -EINVAL;

	return count;

}

static DEVICE_ATTR(nvme_discovery, 0200, NULL, nvme_fc_nvme_discovery_store);

static DEVICE_ATTR(appid_store, 0200, NULL, fc_appid_store);



static struct attribute *nvme_fc_attrs[] = {

	&dev_attr_nvme_discovery.attr,

	&dev_attr_appid_store.attr,

	NULL

};