[LU-16435] don't keep bad local copies of config llogs

• Status: Resolved
• Project: Lustre
• Type: Improvement
• Priority: Minor
• Reporter: Mikhail Pershin
• Assignee: Mikhail Pershin
• Resolution: Not a Bug

Description

The mgc_llog_local_copy() does two-step backup of llogs:

1. local copy to a temporary file
2. remote llog to local copy

though failure in either one are ignored and doesn't prevent mount the reason of failure can be corrupted local copy which will cause mount failure later while being processed.

To prevent that the mgs_llog_local_copy() should delete local copy if first backup failed due to any reason

Comments

[Mikhail Pershin]

While making patch and test for the situation I have found that problem is resolved already in all Lustre current versions. The reason of issue was corrupted local copy of config llog which was still used for processing. Right now the latest code doesn't use local config if it is corrupted but ask for remote llog and even when it is being processed such corruption are skipped due to series of recent patches and mount is not failed. There are still possibilities of more severe corruptions like llog header damage, but such can't be handled by Lustre means, e.g. llog_erase() will just not work, etc. In such cases llogs are to be removed by using debugfs/tunefs or local FS mount access

[Mikhail Pershin]

Not a bug nowadays