[#LU-12301] osc_extent_merge()) ASSERTION( cur->oe_dlmlock == victim->oe

I hit this assertion relatively regularly in b2_12 nowadays, but not in master-*

only in racer so far. So would be great to find out what fix it was in master (don't see anything fitting) and port it over.

[  963.721762] LustreError: 17159:0:(osc_cache.c:524:osc_extent_merge()) ASSERTION( cur->oe_dlmlock == victim->oe_dlmlock ) failed: 
[  963.726428] LustreError: 17159:0:(osc_cache.c:524:osc_extent_merge()) LBUG
[  963.727134] Pid: 17159, comm: dd 3.10.0-7.6-debug #2 SMP Wed Nov 7 02:25:20 EST 2018
[  963.728348] Call Trace:
[  963.728981]  [<ffffffffa01c87dc>] libcfs_call_trace+0x8c/0xc0 [libcfs]
[  963.729705]  [<ffffffffa01c888c>] lbug_with_loc+0x4c/0xa0 [libcfs]
[  963.730405]  [<ffffffffa079802b>] osc_extent_merge+0x7eb/0x870 [osc]
[  963.731122]  [<ffffffffa079f691>] osc_extent_release+0x121/0x400 [osc]
[  963.731854]  [<ffffffffa079127b>] osc_io_end+0x1b/0x30 [osc]
[  963.732537]  [<ffffffffa037c84d>] cl_io_end+0x5d/0x150 [obdclass]
[  963.733220]  [<ffffffffa089187b>] lov_io_end_wrapper+0xdb/0xe0 [lov]
[  963.733907]  [<ffffffffa0891d05>] lov_io_call.isra.7+0x85/0x140 [lov]
[  963.734580]  [<ffffffffa0891df6>] lov_io_end+0x36/0xb0 [lov]
[  963.735232]  [<ffffffffa037c84d>] cl_io_end+0x5d/0x150 [obdclass]
[  963.735963]  [<ffffffffa037ef2a>] cl_io_loop+0xda/0x1c0 [obdclass]
[  963.736703]  [<ffffffffa0e56aeb>] ll_file_io_generic+0x63b/0xcb0 [lustre]
[  963.737427]  [<ffffffffa0e57871>] ll_file_aio_write+0x531/0x880 [lustre]
[  963.738159]  [<ffffffffa0e57c64>] ll_file_write+0xa4/0x170 [lustre]
[  963.738880]  [<ffffffff812362bd>] vfs_write+0xbd/0x1e0
[  963.739569]  [<ffffffff812370bf>] SyS_write+0x7f/0xf0
[  963.740238]  [<ffffffff817c4e15>] system_call_fastpath+0x1c/0x21
[  963.740941]  [<ffffffffffffffff>] 0xffffffffffffffff

[LU-12301] osc_extent_merge()) ASSERTION( cur->oe_dlmlock == victim->oe_dlmlock ) failed Created: 15/May/19 Updated: 16/Jan/22 Resolved: 16/Jan/22
Status:	Closed
Project:	Lustre
Component/s:	None
Affects Version/s:	Lustre 2.13.0, Lustre 2.12.1
Fix Version/s:	None

[LU-12301] osc_extent_merge()) ASSERTION( cur->oe_dlmlock == victim->oe_dlmlock ) failed Created: 15/May/19 Updated: 16/Jan/22 Resolved: 16/Jan/22