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 <ebl...@redhat.com> > --- > block/nbd.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/block/nbd.c b/block/nbd.c > index d085554f21ea..82f9b7ef50a5 100644 > --- a/block/nbd.c > +++ b/block/nbd.c > @@ -1516,8 +1516,10 @@ static int nbd_parse_uri(const char *filename, QDict > *options) > goto out; > } > > - p = uri->path ? uri->path : "/"; > - p += strspn(p, "/"); > + p = uri->path ? uri->path : ""; > + if (p[0] == '/') { > + p++; > + } > if (p[0]) { > qdict_put_str(options, "export", p); > }
Looks reasonable, ACK. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top
