From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 21 Aug 2019 12:25:07 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20190821112507.GB3351@work-vm> References: <20190813192944.26009-1-vgoyal@redhat.com> <20190813192944.26009-2-vgoyal@redhat.com> <20190814085452.GA2920@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190814085452.GA2920@work-vm> Subject: Re: [Virtio-fs] [PATCH 1/4] virtiofsd: Fix number of padding bits in fuse_file_info List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vivek Goyal Cc: virtio-fs@redhat.com * Dr. David Alan Gilbert (dgilbert@redhat.com) wrote: > * Vivek Goyal (vgoyal@redhat.com) wrote: > > Currently we have 27 padding bits while there are 6 bit fields. I suspect > > this is wrong. We probably are trying to aling to 32 bits and hence padding > > bits should be 26 instead. > > > > Signed-off-by: Vivek Goyal > > Yeh, I reckon this was broken upstream by 19accdf ~6 years ago; whether > it's fixable upstream I don't know because they have API requierments > since it's a library. > > Still, it's definitely wrong so: > > Reviewed-by: Dr. David Alan Gilbert Actually I found this upstream bug: https://github.com/libfuse/libfuse/issues/396 which is a 'wontfix'; I think the padding only really exists because of the ABI requirements; so there's not much point in us changing it. We could just drop padding. Dave > > --- > > contrib/virtiofsd/fuse_common.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/contrib/virtiofsd/fuse_common.h b/contrib/virtiofsd/fuse_common.h > > index 6419f66470..4d95f6f28b 100644 > > --- a/contrib/virtiofsd/fuse_common.h > > +++ b/contrib/virtiofsd/fuse_common.h > > @@ -65,7 +65,7 @@ struct fuse_file_info { > > unsigned int flock_release : 1; > > > > /** Padding. Do not use*/ > > - unsigned int padding : 27; > > + unsigned int padding : 26; > > > > /** File handle. May be filled in by filesystem in open(). > > Available in all other file operations */ > > -- > > 2.17.2 > > > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK