[LU-49] There is a race window between server obd cleanup and its handling of client connection

• Type: Bug
• Resolution: Cannot Reproduce
• Priority: Minor
• Affects Version/s: Lustre 1.8.6
• Severity: 3
• Assignee: Zhenyu Xu
• Reporter: Zhenyu Xu

Description

In class_cleanup() before the server obd's stopping flag is set, a new
client connection request can be handled in target_handle_connect();
after the target obd (server obd) is found, and before its refcount is
increased, class_cleanup() can be processed and run through
class_decref(); it find that the server obd's refcount becomes to 0;
at this point, target_handle_connect() can go on and add target obd
(server obd) refcount and create the client export.