From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44952) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fzmrc-0000AN-7g for qemu-devel@nongnu.org; Tue, 11 Sep 2018 13:54:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fzmrX-0000hT-Lf for qemu-devel@nongnu.org; Tue, 11 Sep 2018 13:54:11 -0400 Date: Tue, 11 Sep 2018 13:53:53 -0400 From: Jeff Cody Message-ID: <20180911175353.GO22117@localhost.localdomain> References: <570e8585c94d6f1bd7406ce5d35f68a82b6ea28c.1536642773.git.jcody@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <570e8585c94d6f1bd7406ce5d35f68a82b6ea28c.1536642773.git.jcody@redhat.com> Subject: Re: [Qemu-devel] [PATCH 2/2] block/rbd: Attempt to parse legacy filenames List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, qemu-stable@nongnu.org, jsnow@redhat.com, kwolf@redhat.com, armbru@redhat.com On Tue, Sep 11, 2018 at 01:15:49AM -0400, Jeff Cody wrote: > When we converted rbd to get rid of the older key/value-centric > encoding format, we broke compatibility with image files with backing > file strings encoded in the old format. > > This leaves a bit of an ugly conundrum, and a hacky solution. > > If the initial attempt to parse the "proper" options fails, it assumes > that we may have an older key/value encoded filename. Fall back to > attempting to parse the filename, and extract the required options from > it. If that fails, pass along the original error message. > > This approach has a potential drawback: if for some reason there are > some options supplied the new way, and some the old way, we may not > catch all the old options if they are not required options (since it > won't cause the initial failure). > > Signed-off-by: Jeff Cody > --- > block/rbd.c | 30 +++++++++++++++++++++++++++--- > 1 file changed, 27 insertions(+), 3 deletions(-) > > diff --git a/block/rbd.c b/block/rbd.c > index a8e79d01d2..bce86b8bde 100644 > --- a/block/rbd.c > +++ b/block/rbd.c > @@ -685,7 +685,7 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags, > BlockdevOptionsRbd *opts = NULL; > const QDictEntry *e; > Error *local_err = NULL; > - char *keypairs, *secretid; > + char *keypairs, *secretid, *filename; > int r; > > keypairs = g_strdup(qdict_get_try_str(options, "=keyvalue-pairs")); > @@ -700,8 +700,32 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags, > > r = qemu_rbd_convert_options(bs, options, &opts, &local_err); > if (local_err) { > - error_propagate(errp, local_err); > - goto out; > + /* If the initial attempt to convert and process the options failed, > + * we may be attempting to open an image file that has the rbd options > + * specified in the older format consisting of all key/value pairs > + * encoded in the filename. Go ahead and attempt to parse the > + * filename, and see if we can pull out the required options */ > + Error *parse_err = NULL; > + > + filename = g_strdup(qdict_get_try_str(options, "filename")); I'm leaking filename, I'll clean that up (along with any other comments) in v2. > + qdict_del(options, "filename"); > + > + qemu_rbd_parse_filename(filename, options, NULL); > + > + g_free(keypairs); > + keypairs = g_strdup(qdict_get_try_str(options, "=keyvalue-pairs")); > + if (keypairs) { > + qdict_del(options, "=keyvalue-pairs"); > + } > + > + r = qemu_rbd_convert_options(bs, options, &opts, &parse_err); > + if (parse_err) { > + /* if the second attempt failed, pass along the original error > + * message for the current format */ > + error_propagate(errp, local_err); > + error_free(parse_err); > + goto out; > + } > } > > /* Remove the processed options from the QDict (the visitor processes > -- > 2.17.1 >