[LU-10302] hsm: obscure bug with multi-mountpoints and ldlm

Related — Wed, 5 Aug 2020 13:50:22 +0000

I do not have much to share except the attached reproducer.

The key elements of the reproducer seem to be:

setup lustre with two mountpoints;
create a file;
launch a copytool on mountpoint A;
suspend the copytool;
archive the file created at step 1 from mountpoint A*;
delete the file on mountpoint B;
sync;
un-suspend the copytool (the output of the copytool should indicate that llapi_hsm_action_begin() failed with EIO, not ENOENT)
umount => the process hangs in an unkillable state.

*You can use mountpoint B at step 5, but only if you created the file from mountpoint A.

I added some debug in the reproducer that should be logged in /tmp.

I suspect those two lines in the dmesg are related to this issue (they are logged at umount time):

[  143.575078] LustreError: 3703:0:(ldlm_resource.c:1094:ldlm_resource_complain()) filter-lustre-OST0000_UUID: namespace resource [0x2:0x0:0x0].0x0 (ffff8806ab7b6900) refcount nonzero (1) after lock cleanup; forcing cleanup.
[  143.578233] LustreError: 3703:0:(ldlm_resource.c:1676:ldlm_resource_dump()) --- Resource: [0x2:0x0:0x0].0x0 (ffff8806ab7b6900) refcount = 2

Note: the title should probably be updated once we figure what the issue exactly is

Whamcloud Community JIRA

[LU-10302] hsm: obscure bug with multi-mountpoints and ldlm