[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH v6 01/13] block: Add op blocker type "device IO"

From: Max Reitz
Subject: Re: [Qemu-devel] [PATCH v6 01/13] block: Add op blocker type "device IO"
Date: Sat, 23 May 2015 18:51:27 +0200
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0

On 22.05.2015 06:54, Fam Zheng wrote:
On Thu, 05/21 15:32, Fam Zheng wrote:
On Thu, 05/21 15:06, Wen Congyang wrote:
On 05/21/2015 02:42 PM, Fam Zheng wrote:
It blocks device IO.

All bdrv_op_block_all/blk_op_block_all callers are taken care of:

- virtio_blk_data_plane_create
- virtio_scsi_hotplug

   Device creation, unblock it.

- bdrv_set_backing_hd

   Backing hd is not used by device, so blocking is OK.

- backup_start

   Blocking target when backup is running, unblock it.
Do you forget it?
Oh I think the commit log is wrong: the target image is only written to by
block job, there cannot be a device on it, so it it's similar to
Correction: if it's blockdev-backup, the target could have a device, in that
sense it should be unblocked like block_job_create(). I'll fix it.

Really? I think it makes sense not to allow I/O on a backup target. At least I can't imagine a use case where you'd want to do that... But that doesn't necessarily mean anything, of course.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]