[LU-10173] Lustre does not allow FIEMAP on directories

Wed, 13 Dec 2017 09:24:43 +0000

Even though ext4 allows FIEMAP on directories, Lustre does not, returning -EOPNOTSUPP.

It should mostly be a matter of sending the FIEMAP RPC to the MDS instead of the OSS.

Some care would be needed for striped directories, possibly using FIEMAP_FL_DEVICE_ORDER in this case, rather than forcing the LMV to interleave all of the blocks. However, since directories will already typically be very fragmented, it won't make the output much worse if DEVICE_ORDER is not used.

Whamcloud Community JIRA

[LU-10173] Lustre does not allow FIEMAP on directories