[LUDOC-279] Add commands leading to setxattr to the doc/protocol document

• Type: Technical task
• Resolution: Done
• Priority: Minor
• Assignee: Andrew Uselton (Inactive)
• Reporter: Andrew Uselton (Inactive)

Description

The shell command 'setfattr' issues a non-POSIX system call
'setxattr()' which results in a call to 'll_setxattr()' in
lustre/llite/xattr.c.

Document the messages exchanged to carry out this operation as well as
any state change that it can cause.