I can consistently replicate this error message.
I suppose it might make sense that a file should not be released if it is truly dirty. But the error message does not seem to be appropriate. Perhaps it should not even be possible to clear a 'dirty' state
This is a comment from another person I've consulted on this:
The error comes from the MDT:
00000004:20000000:0.0:1414607590.182318:0:1585:0:(mdt_open.c:2042:mdt_hsm_release()) [0x2000013c2:0x116c3:0x0] data_version mismatches: packed=4313503196 and on-disk=4313503194
so it doesn't set the OBD_MD_FLRELEASED bit, and the client in turn returns EBUSY.
No idea what that means though.