From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Stodden Subject: [PATCH 0 of 7] blktap2: The tap-ctl userspace control utility and library Date: Mon, 07 Jun 2010 21:54:47 -0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Xen List-Id: xen-devel@lists.xenproject.org Hi. Apart from removing some dead code and tidying up tapdisk-vbd a little, the bigger introduces our new tap-ctl utility code. The code aims to be a complete replacement for the original blktap2 control path, run through sysfs. Fully implemented in userspace, all tapdisks now gained a small IPC layer on top of Unix domain sockets. Sample usage: # tap-ctl allocate /dev/xen/blktap-2/tapdev0 # tap-ctl spawn tapdisk spawned with pid 4168 # tap-ctl list 4168 - - - - - 0 - - - # tap-ctl attach -p 4168 -m 0 # tap-ctl list 4168 0 0 - - # tap-ctl open -p 4168 -m 0 -a aio:/var/tmp/lenny.ext # tap-ctl list 4168 0 0 aio /var/tmp/lenny.ext # tap-ctl close -p 4168 -m 0 # tap-ctl detach -p 4168 -m 0 # tap-ctl free -m 0 The above example is a bit noisy, because it's mediating between minor number (block devices), tapdisks and tapdisk VBDs (the tapdisk I/O queue running a bdev) in detail. There are shortcuts. At the same time, the low-level interface should be general enough to stay extensible, and help accomodate some of the more esoteric features, like shared images and/or multiple VBDs sharing the same tapdisk. Cheers, Daniel