Sorry, let me rephrase
I wanted to know in case where o_trunc is interpreted as 2 separate
messages, as FSAL_O_TRUNC is not enabled, how does the mdcache get
notification to invalide cache?
Thank you
I suppose that
Le mer. 8 août 2018 à 17:33, Frank Filz <ffilzlnx(a)mindspring.com> a écrit :
> Well, after a cup of coffee I double checked thing. I confirm
that for a
call open
> with O_TRUNC flag, my NFS client (linux centos7) sends a OPEN message
(do'nt
> see FSAL_O_TRUNC flag propagated to open2 so may be it is not set by the
> client) and a separate SETATTR message with size = 0.
If the truncate comes as a separate SETATTR then everything should work
just fine. The open2 call won't have FSAL_O_TRUNC, but there will be a
subsequent setattr2 call with size = 0.
> So I don't know how my FSAL can handle O_TRUNC within open2 function and
> AWAIU since it does not return the attr changes (size and ctime) in
attrs_out,
> MDcache can not invalidate the cache and I'll have info inconsistency
between
> the backend and the mdcache theorically.
I don't quite understand the issue here. MDCACHE invalidates the
attributes if open2 is called with FSAL_O_TRUNC.
Are you saying your FSAL wouldn't be able to handle FSAL_O_TRUNC? At
worst, you have to do a setattr yourself.
I do see some paths through open2 in MDCACHE where we could improve the
attribute situation.
We did improve on the case of mdcache_open2_by_name finding the entry in
cache, I think we do update the attributes from the underlying FSAL's open2
(by handle) in that case.
Frank