On 11/9/20 5:23 AM, Muneendra wrote:
Added a new sysfs attribute appid_store under
/sys/class/fc/fc_udev_device/*
With this new interface the user can set the application identfier
in the blkcg associted with cgroup id.
Once the application identifer has set with this interface it allows
identification of traffic sources at an individual cgroup based
Applications (ex:virtual machine (VM))level in both host and
fabric infrastructure(FC).
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
Signed-off-by: Muneendra <muneendra.kumar@xxxxxxxxxxxx>
---
v4:
No change
v3:
Replaced blkcg_set_app_identifier function with blkcg_set_fc_appid
v2:
New Patch
---
drivers/nvme/host/fc.c | 73 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 72 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index eae43bb444e0..6d6cc06fd54a 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -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>
@@ -3768,10 +3768,81 @@ static ssize_t nvme_fc_nvme_discovery_store(struct device *dev,
return count;
}
+
+/*parse the Cgroup id from a buf and returns 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 :parses and updates 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[APPID_LEN];
+ int ret = 0;
+
+ if (buf[count-1] == '\n')
+ count--;
+
+ if ((count > (16+1+APPID_LEN)) || (!strchr(buf, ':')))
+ return -EINVAL;
+
+ cgrpid_len = fc_parse_cgrpid(buf, &cgrp_id);
+ if (cgrpid_len < 0)
+ return -EINVAL;
+ /*appid len is count - cgrpid_len -1 (: + \n) */
+ appid_len = count - cgrpid_len - 1;
+ if (appid_len > APPID_LEN)
+ return -EINVAL;
+
+ memset(app_id, 0x0, sizeof(app_id));
+ memcpy(app_id, &buf[cgrpid_len+1], appid_len);
+ ret = blkcg_set_app_identifier(app_id, cgrp_id, sizeof(app_id));
+ if (ret < 0)
+ return ret;
+ return count;
+}
+
Right. So you _do_ allow for an arbitrary length for the app_id.
Which means the previous patch had a bug, and you need to allocate
APPID_LEN + 1 for the 'app_id' entry.
+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
};
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
