Re: [PATCH] nbd-client: Support leading / in NBD URI

[Maxim Levitsky <mlevitsk@redhat.com>]

On Wed, 2020-02-12 at 14:33 +0100, Ján Tomko wrote:
> On Tue, Feb 11, 2020 at 08:31:01PM -0600, Eric Blake wrote:
> > The NBD URI specification [1] states that only one leading slash at
> > the beginning of the URI path component is stripped, not all such
> > slashes.  This becomes important to a patch I just proposed to nbdkit
> > [2], which would allow the exportname to select a file embedded within
> > an ext2 image: ext2fs demands an absolute pathname beginning with '/',
> > and because qemu was inadvertantly stripping it, my nbdkit patch had
> > to work around the behavior.
> > 
> > [1] https://github.com/NetworkBlockDevice/nbd/blob/master/doc/uri.md
> > [2] https://www.redhat.com/archives/libguestfs/2020-February/msg00109.html
> > 
> > Note that the qemu bug only affects handling of URIs such as
> > nbd://host:port//abs/path (where '/abs/path' should be the export
> > name); it is still possible to use --image-opts and pass the desired
> > export name with a leading slash directly through JSON even without
> > this patch.
> > 
> > Signed-off-by: Eric Blake <eblake@redhat.com>
> > ---
> > block/nbd.c | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> 
> Reviewed-by: Ján Tomko <jtomko@redhat.com>
> 
> Jano
Note that I had a bug open for this.
https://bugzilla.redhat.com/show_bug.cgi?id=1728545

I expected this to be a feature to be honest,
and was afraid to break existing users that might rely on this.

Best regards,
	Maxim Levitsky