[LU-16260] LNet: enforce a positive minimum for lnd_timeout

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.16.0
• Severity: 3
• Assignee: Frank Sehr
• Reporter: Serguei Smirnov

Description

lnd_timeout is calculated using the following formula:

lnd_timeout = (lnet_transaction_timeout - 1) / (retry_count + 1) 

currently lnet_transaction_timeout is allowed to be as low as 1 which makes derived 0 lnd_transaction timeout value possible, for example:

# lnetctl set transaction_timeout 1
# lnetctl global show
global:
    numa_range: 0
    max_interfaces: 200
    discovery: 1
    drop_asym_route: 0
    retry_count: 0
    transaction_timeout: 1
    health_sensitivity: 100
    recovery_interval: 1
    router_sensitivity: 100
    lnd_timeout: 0
    response_tracking: 3
    recovery_limit: 0
    max_recovery_ping_interval: 900

There probably should be reasonable minimal positive thresholds defined for both lnd_timeout and lnet_transaction_timeout.