From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53312) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1axYMt-0005Ki-6k for qemu-devel@nongnu.org; Tue, 03 May 2016 07:20:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1axYMh-0001Z7-Gl for qemu-devel@nongnu.org; Tue, 03 May 2016 07:19:49 -0400 References: <1461706338-20219-1-git-send-email-mreitz@redhat.com> <1461706338-20219-7-git-send-email-mreitz@redhat.com> <20160502153611.GJ4882@noname.redhat.com> From: Max Reitz Message-ID: <57288929.7050804@redhat.com> Date: Tue, 3 May 2016 13:19:05 +0200 MIME-Version: 1.0 In-Reply-To: <20160502153611.GJ4882@noname.redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="DRoc08CA0WVP9BqP7aRv6RgKRkn3xL9IJ" Subject: Re: [Qemu-devel] [PATCH 06/19] block: Make bdrv_default_refresh_format_filename public List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Alberto Garcia , Eric Blake This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --DRoc08CA0WVP9BqP7aRv6RgKRkn3xL9IJ Content-Type: multipart/mixed; boundary="KhxiwvMbSSoGgJ93cI5XHLg6qTq18uPoj" From: Max Reitz To: Kevin Wolf Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Alberto Garcia , Eric Blake Message-ID: <57288929.7050804@redhat.com> Subject: Re: [PATCH 06/19] block: Make bdrv_default_refresh_format_filename public References: <1461706338-20219-1-git-send-email-mreitz@redhat.com> <1461706338-20219-7-git-send-email-mreitz@redhat.com> <20160502153611.GJ4882@noname.redhat.com> In-Reply-To: <20160502153611.GJ4882@noname.redhat.com> --KhxiwvMbSSoGgJ93cI5XHLg6qTq18uPoj Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 02.05.2016 17:36, Kevin Wolf wrote: > Am 26.04.2016 um 23:32 hat Max Reitz geschrieben: >> In order to allow block drivers to use that function, it needs to be >> public. In order to be useful, it needs to take a parameter which allo= ws >> the caller to specify whether the runtime options allowed by the block= >> driver are actually significant for the guest-visible BDS content. >> >> Signed-off-by: Max Reitz >=20 > Is this actually good enough? I expect that many drivers will have some= > options that are significant and other options that aren't. We already > have some (Quorum: children are significant, rewrite-corrupted isn't), > but as we convert more things to proper options, we'll get more of them= > (raw-posix: filename is significant, aio=3Dnative isn't). >=20 > We might actually need to pass a list of significant fields instead tha= t > append_open_options() can use. Well, in theory, every driver with insignificant options would just implement .bdrv_refresh_filename() however it's needed. Making bdrv_default_refresh_format_filename() function public is just a way of keeping that implementation very simple for some drivers that only have insignificant options. I'm not opposed to extending this function in the future when it actually makes sense. Right now I don't think it does. The only thing that changes if a significant option is detected is that no plain filename is generated; however, for Quorum we can never generate such a filename. Therefore, we cannot use this function for Quorum anyway. However, instead of extending this function, it may make more sense then to introduce a new field to the BlockDriver struct which is a NULL-terminated array of significant option names, or something like that. If .bdrv_refresh_filename is NULL but that array pointer is not, then the default implementation could behave accordingly. But this is something I'd defer to the future, too, unless you can point out a current block driver that would benefit from this functionality (I don't think Quorum does, as I said above). Max --KhxiwvMbSSoGgJ93cI5XHLg6qTq18uPoj-- --DRoc08CA0WVP9BqP7aRv6RgKRkn3xL9IJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJXKIkpAAoJEDuxQgLoOKytAyoIAJjWet8JQ8KgKRZ7kPW0ms5k uHJe7BgSJUTOnUhMVjs8xv54XktJ8z7PB5sZRpSaH/wFd7nOvlguCdx/LOS5nhs0 TbORcnXJRdISNTxHT7/ROdulZUW9f9EUmPhHr2FGsZt9pjT1jNLY0WruDNp3DJXx gqhiCpfdOtJjyX0ZKOsBiaO/HrNFVGj9UH3+kQ1aSrbj/qcCl/PSm8eaZh7aujtI cLoG44j52NrcN46yRhF4Rrvu/s/UA13qAch5ffGtIVejNc+hG5QsLt8hEU1A/S88 e5/JCK8dGeHihO/SMaa03hkWC88m9TXkf5XlCOgHbUvzFb3IwogvjdxW0UV4Khg= =fXCD -----END PGP SIGNATURE----- --DRoc08CA0WVP9BqP7aRv6RgKRkn3xL9IJ--