On Wed, Sep 02, 2020 at 08:52:25PM -0700, Darrick J. Wong wrote: > Hi, > > I have a question for everyone-- do FICLONE and FICLONERANGE count as a > "write operation" for the purposes of reasoning about O_SYNC and > O_DSYNC? I'd say yes, because we are changing metadata that is used to directly reference the data in the file. O_DSYNC implies all the metadata needed to access the data is on stable storage when the operation returns.... > So, that's inconsistent behavior and I want to know if remap_file_range > is broken or if we all just don't care about O_SYNC for these fancy > IO accelerators? Perhaps we should pay attention to the NFSD implementation of CloneFR - if the operation is sync then it will run fsync on the destination and commit_metadata on the source inode. See nfsd4_clone_file_range(). So, yeah, I think clone operations need to pay attention to O_DSYNC/O_SYNC/IS_SYNC().... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
