xref: /linux/Documentation/ABI/testing/sysfs-class-fc (revision 03ab8e6297acd1bc0eedaa050e2a1635c576fd11)
1*e9d73bfaSMuneendra KumarWhat:		/sys/class/fc/fc_udev_device/appid_store
2*e9d73bfaSMuneendra KumarDate:		Aug 2021
3*e9d73bfaSMuneendra KumarContact:	Muneendra Kumar <muneendra.kumar@broadconm.com>
4*e9d73bfaSMuneendra KumarDescription:
5*e9d73bfaSMuneendra Kumar		This interface allows an admin to set an FC application
6*e9d73bfaSMuneendra Kumar		identifier in the blkcg associated with a cgroup id. The
7*e9d73bfaSMuneendra Kumar		identifier is typically a UUID that is associated with
8*e9d73bfaSMuneendra Kumar		an application or logical entity such as a virtual
9*e9d73bfaSMuneendra Kumar		machine or container group. The application or logical
10*e9d73bfaSMuneendra Kumar		entity utilizes a block device via the cgroup id.
11*e9d73bfaSMuneendra Kumar		FC adapter drivers may query the identifier and tag FC
12*e9d73bfaSMuneendra Kumar		traffic based on the identifier. FC host and FC fabric
13*e9d73bfaSMuneendra Kumar		entities can utilize the application id and FC traffic
14*e9d73bfaSMuneendra Kumar		tag to identify traffic sources.
15*e9d73bfaSMuneendra Kumar
16*e9d73bfaSMuneendra Kumar		The interface expects a string "<cgroupid>:<appid>" where:
17*e9d73bfaSMuneendra Kumar		<cgroupid> is inode of the cgroup in hexadecimal
18*e9d73bfaSMuneendra Kumar		<appid> is user provided string upto 128 characters
19*e9d73bfaSMuneendra Kumar		in length.
20*e9d73bfaSMuneendra Kumar
21*e9d73bfaSMuneendra Kumar		If an appid_store is done for a cgroup id that already
22*e9d73bfaSMuneendra Kumar		has an appid set, the new value will override the
23*e9d73bfaSMuneendra Kumar		previous value.
24*e9d73bfaSMuneendra Kumar
25*e9d73bfaSMuneendra Kumar		If an admin wants to remove an FC application identifier
26*e9d73bfaSMuneendra Kumar		from a cgroup, an appid_store should be done with the
27*e9d73bfaSMuneendra Kumar		following string: "<cgroupid>:"
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