[LTP] [PATCH v4 9/9] syscalls/sync_file_range: add sync device test-case

[Cyril Hrubis]

Hi!
> > This tests fails for me for fuse based filesystems, the call returns 0
> > but does not write anything, the questions is if this is desired
> > behavior or not.
> >
> 
> Interesting case. Do you see similar behaviour with other sync related syscalls?

Just this one, I would have expected that the new syscall is not wired
into fuse yet hence it does nothing silently instead of returning
EOPNOTSUPP which could break applications...

> AFAIK, fuse file-system operations are implemented in user-space
> daemons exported to kernel as callbacks via libfuse. Maybe we need to
> check fsync() callback operation [1] implementation?
> 
> [1] https://libfuse.github.io/doxygen/structfuse__operations.html
> 
> > Also we should as well add a second test here that sync only a middle of
> > a written region of a file and expects that the data written are
> > somewhere between a few percents of the synced size.
> >
> 
> Sure, will add a test for this.

Ideally this should be put into the existing test in order to spare time
needed to format the devices etc.

-- 
Cyril Hrubis
chrubis@suse.cz