From 2485f22fe9211b2e80970f83199b320eee211319 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Tue, 11 Feb 2020 20:31:01 -0600 Subject: nbd-client: Support leading / in NBD URI MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Message-Id: <20200212023101.1162686-1-eblake@redhat.com> Reviewed-by: Ján Tomko --- block/nbd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/nbd.c b/block/nbd.c index 6d3b22f..f69e61e 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -1528,8 +1528,10 @@ 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); } -- cgit v1.1