[LU-13523] zero link directory causes crash on 2.12

Wed, 6 May 2020 15:50:47 +0000

I have an older file system of roughly 400 million files that i'm about to move to new hardware. The FS is running lustre 2.8.0 on centos 6.

While traversing the file system, I found there exist some directories apparently with zero references. Here is an example such directory:

drwxr-s--- 0 <user> <group> 12288 Sep 11 2016 goes3.1980.286.1915

When attempting to list this directory on lustre 2.12.3 or 2.12.4 on centos 7/8 clients, it caused the system to crash. In one instance, I observed this LBUG:

kernel:LustreError: 19084:0:(mdc_locks.c:124:mdc_set_lock_data()) ASSERTION( old_inode->i_state & I_FREEING ) failed: Found existing inode ffff9de915cb7110/144115292816098530/0 state 0 in lock: setting data to ffff9de915cb6c90/144115292816098530/33554456Message from syslogd@s4-609-c1 at May 6 13:22:28 ...
kernel:LustreError: 19084:0:(mdc_locks.c:124:mdc_set_lock_data()) LBUG
This does not occur on lustre 2.10.6. I downgraded to 2.10.6 and now simply receive "no such file or directory" instead.

Whamcloud Community JIRA

[LU-13523] zero link directory causes crash on 2.12