Addition of LU-2049 patch http://review.whamcloud.com/7793 seems to be breaking interop in particular test 78 of sanity.sh so I filing this ticket just in case.

I am testing with upstream client, but 2.5 and 2.7 at the very least are likely affected, possibly even 2.8, so we need to double check.

With the patch in place on the server, client running test 78 fails on the 5th iteration like this:
directIO rdwr round 5 of 5
directio on /mnt/lustre/f78.sanity for 130x1048576 bytes
Write error Success (rc = 83886080, len = 136314880)
sanity test_78: @@@@@@ FAIL: rdwr failed

This suggests the write was short due to overzealous limitation of free space on the server or something else.

I confirmed that removing that patch fixes the failure.

additional issue - test 78 does not cleanup the big file on error leading to a chain of out of space failures later on in the sanity.sh at least in my setup

This is on ldiskfs