[LU-3716] mds-survey ASSERTION( lu_device_is_mdt(o->lo_dev) )

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.7.0
• Affects Version/s: Lustre 2.4.0, Lustre 2.5.1
• Labels: HB llnl server zfs
• Severity: 3
• Assignee: Jian Yu
• Reporter: Brian Behlendorf

Description

Observed fairly repeatably when running mds-survey.sh after the first few million creates. It appears unlikely to occur when creating less than 100,00 objects (the default).

2013-08-06 15:05:51 LustreError: 4379:0:(mdt_handler.c:2352:mdt_obj()) ASSERTION( lu_device_is_mdt(o->lo_dev) ) failed:
2013-08-06 15:05:51 LustreError: 4379:0:(mdt_handler.c:2352:mdt_obj()) LBUG

The failures where observed with code post 2.4.0 which includes the LU-2758 fix.

Comments

[Gerrit Updater]

Jian Yu ([e-mail]) uploaded a new patch: http://review.whamcloud.com/13530
Subject: LU-3716 obdecho: create a separate root object for echo access
Project: fs/lustre-release
Branch: b2_5
Current Patch Set: 1
Commit: 9a208e3e205a1a31b2773893f8333dbc275e0e6e

[Peter Jones]

Landed for 2.7

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch http://review.whamcloud.com/10130/
Subject: LU-3716 obdecho: create a separate root object for echo access
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 897580eb1562e0509bbe8ea72a273ed71f878eaa

[Jian Yu]

Can this patch be rebased?

Sure, will do.

[Doug Oucharek (Inactive)]

Can this patch be rebased?

[Jian Yu]

Patch for master branch: http://review.whamcloud.com/10130

[Di Wang]

IMHO, I do not think you need(should) change MDD. I think you create create a separate root object for echo access, so in echo_resolve_path, it will always start from that root object, and form its own tree, instead of using file system ROOT. And normal client will never see this tree under this special root.

You can see how MDD create the root object in mdd_prepare.