Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-26 Thread Peter Lieven
Am 26.06.2013 um 05:14 schrieb Bharata B Rao bhar...@linux.vnet.ibm.com: On Tue, Jun 25, 2013 at 01:39:11PM +0200, Kevin Wolf wrote: Can you please review for the gluster, rbd, sheepdog and ssh driver whether it's safe to assume that the image reads back as zeros after bdrv_create?

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-26 Thread Bharata B Rao
On Wed, Jun 26, 2013 at 07:59:27AM +0200, Peter Lieven wrote: Am 26.06.2013 um 05:14 schrieb Bharata B Rao bhar...@linux.vnet.ibm.com: On Tue, Jun 25, 2013 at 01:39:11PM +0200, Kevin Wolf wrote: Can you please review for the gluster, rbd, sheepdog and ssh driver whether it's safe to

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-26 Thread Kevin Wolf
Am 26.06.2013 um 08:46 hat Bharata B Rao geschrieben: On Wed, Jun 26, 2013 at 07:59:27AM +0200, Peter Lieven wrote: Am 26.06.2013 um 05:14 schrieb Bharata B Rao bhar...@linux.vnet.ibm.com: On Tue, Jun 25, 2013 at 01:39:11PM +0200, Kevin Wolf wrote: Can you please review for the

[Qemu-devel] block: Review of .has_zero_init use

2013-06-25 Thread Kevin Wolf
Hi all, while discussing some iscsi patches with Peter, we came to have a look at which block drivers implement has_zero_init() to return 0, and which don't (returning 1 is the default). The meaning of this value is that if has_zero_init != 0, after bdrv_create() one can assume that the whole

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-25 Thread Richard W.M. Jones
On Tue, Jun 25, 2013 at 01:39:11PM +0200, Kevin Wolf wrote: * ssh - currently has_zero_init = 1 (is this correct?) [...] It might be possible that the correct value depends on the backend on the server side for some protocols - for example, I think for SSH it depends on whether you

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-25 Thread Kevin Wolf
Am 25.06.2013 um 14:05 hat Richard W.M. Jones geschrieben: On Tue, Jun 25, 2013 at 01:39:11PM +0200, Kevin Wolf wrote: * ssh - currently has_zero_init = 1 (is this correct?) [...] It might be possible that the correct value depends on the backend on the server side for some

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-25 Thread MORITA Kazutaka
At Tue, 25 Jun 2013 13:39:11 +0200, Kevin Wolf wrote: Hi all, while discussing some iscsi patches with Peter, we came to have a look at which block drivers implement has_zero_init() to return 0, and which don't (returning 1 is the default). The meaning of this value is that if

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-25 Thread Kevin Wolf
Am 25.06.2013 um 15:11 hat MORITA Kazutaka geschrieben: At Tue, 25 Jun 2013 13:39:11 +0200, Kevin Wolf wrote: Hi all, while discussing some iscsi patches with Peter, we came to have a look at which block drivers implement has_zero_init() to return 0, and which don't (returning 1 is

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-25 Thread MORITA Kazutaka
At Tue, 25 Jun 2013 15:20:18 +0200, Kevin Wolf wrote: Am 25.06.2013 um 15:11 hat MORITA Kazutaka geschrieben: At Tue, 25 Jun 2013 13:39:11 +0200, Kevin Wolf wrote: Hi all, while discussing some iscsi patches with Peter, we came to have a look at which block drivers

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-25 Thread Kevin Wolf
Am 25.06.2013 um 15:42 hat MORITA Kazutaka geschrieben: At Tue, 25 Jun 2013 15:20:18 +0200, Kevin Wolf wrote: Am 25.06.2013 um 15:11 hat MORITA Kazutaka geschrieben: At Tue, 25 Jun 2013 13:39:11 +0200, Kevin Wolf wrote: Hi all, while discussing some iscsi patches

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-25 Thread Josh Durgin
On 06/25/2013 04:39 AM, Kevin Wolf wrote: Can you please review for the gluster, rbd, sheepdog and ssh driver whether it's safe to assume that the image reads back as zeros after bdrv_create? This is always safe for rbd.

Re: [Qemu-devel] block: Review of .has_zero_init use

2013-06-25 Thread Bharata B Rao
On Tue, Jun 25, 2013 at 01:39:11PM +0200, Kevin Wolf wrote: Can you please review for the gluster, rbd, sheepdog and ssh driver whether it's safe to assume that the image reads back as zeros after bdrv_create? Gluster supports both file and block backends. While the above is true for file