|
From: | Max Reitz |
Subject: | Re: [Qemu-block] [PATCH v3 06/12] nbd-server: Clear "can_read" when "device io" blocker is set |
Date: | Mon, 18 May 2015 20:35:32 +0200 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 |
On 15.05.2015 08:04, Fam Zheng wrote:
So that NBD export cannot submit IO during bdrv_drain_all(). Signed-off-by: Fam Zheng <address@hidden> --- nbd.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
But can_read is not cleared until nbd_update_can_read() is called, which is only in nbd_request_get(), nbd_request_put(), and nbd_co_receive_request(), which are all called from nbd_trip() - so the one request which clears can_read will most probably be itself processed.
Maybe we should call nbd_update_can_read() in nbd_op_blocker_changed(), for all clients of the export? Or just once somewhere at the beginning of processing a request, and if io_blocked is set, just yield...
Max
[Prev in Thread] | Current Thread | [Next in Thread] |