[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [Qemu-block] [PATCH v1 07/15] block: add flag to indica
From: |
Daniel P. Berrange |
Subject: |
Re: [Qemu-devel] [Qemu-block] [PATCH v1 07/15] block: add flag to indicate that no I/O will be performed |
Date: |
Wed, 13 Jan 2016 17:56:24 +0000 |
User-agent: |
Mutt/1.5.24 (2015-08-30) |
On Wed, Jan 13, 2016 at 06:44:41PM +0100, Kevin Wolf wrote:
> Am 12.01.2016 um 19:56 hat Daniel P. Berrange geschrieben:
> > When opening an image it is useful to know whether the caller
> > intends to perform I/O on the image or not. In the case of
> > encrypted images this will allow the block driver to avoid
> > having to prompt for decryption keys when we merely want to
> > query header metadata about the image. eg qemu-img info
> >
> > Signed-off-by: Daniel P. Berrange <address@hidden>
>
> Would it be worth adding assertions to the block layer I/O functions
> (most importantly, bdrv_aligned_preadv/pwritev) that this flag isn't
> set?
Yes, I think so.
In the read/write code paths that trigger encryption, I'm already doing
an assert that the encryption context is setup, which is indirectly
related to BDRV_O_NO_IO. It is probably worth adding an assertion
explicitly based on the flag at the top level though, as it'd give
a clearer error if it ever got triggered.
Regards,
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
- [Qemu-devel] [PATCH v1 00/15] Support LUKS encryption in block devices, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 01/15] crypto: add cryptographic random byte source, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 02/15] crypto: add support for PBKDF2 algorithm, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 03/15] crypto: add support for generating initialization vectors, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 09/15] qcow2: make qcow2_encrypt_sectors encrypt in place, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 07/15] block: add flag to indicate that no I/O will be performed, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 11/15] qcow: make encrypt_sectors encrypt in place, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 14/15] block: remove all encryption handling APIs, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 12/15] qcow: convert QCow to use QCryptoBlock for encryption, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 15/15] block: remove support for legecy AES qcow/qcow2 encryption, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 08/15] block: add generic full disk encryption driver, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 13/15] block: rip out all traces of password prompting, Daniel P. Berrange, 2016/01/12
- [Qemu-devel] [PATCH v1 10/15] qcow2: convert QCow2 to use QCryptoBlock for encryption, Daniel P. Berrange, 2016/01/12