Even after https://review.whamcloud.com/#/c/45636/ lands there will still be error propagation issues in mdt_mdt_close(). This function will "continue to close even if error occurred". If an error occurs in one of the MDS_HSM_RELEASE, MDS_CLOSE_LAYOUT_*, or MDS_CLOSE_RESYNC_DONE cases then we need to ensure that the error is properly returned and is seen by the sender of the close RPC.

Please go through this function line-by-line to ensure that we are propagating and not clobbering errors.

We should also make sure that we are masking errors properly in some cases.