Comment 2 for bug 1681410

I'm thinking that the bug is in the OCFS2 filesystem driver. Since it can span multiple disks, both local and remote, it can not give a sensible answer to the FIBMAP ioctl when fstrim asks what blocks a file is located in. Please test this by creating a file and checking where FIBMAP says it is located and see if the data is really there:

echo hello > foo
hdparm --fibmap foo
dd count=1 bs=size if=/dev/dm-2 skip=offset | hd

Where size is whatever the block size of the filesystem is ( 4k? ), and offset is the block number given by the hdparm call.

Am I correct in assuming this filesystem spans at least two devices? dm-2 and dm-3?