From 8ab0144a466320cc37c52e7866b5103c5bbd4e90 Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Wed, 3 Jun 2015 13:40:02 +0800 Subject: [PATCH] driver: xen-blkfront: move talk_to_blkback to a more suitable place MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The major responsibility of talk_to_blkback() is allocate and initialize the request ring and write the ring info to xenstore. But this work should be done after backend entered 'XenbusStateInitWait' as defined in the protocol file. See xen/include/public/io/blkif.h in XEN git tree: Front Back ================================= ===================================== XenbusStateInitialising XenbusStateInitialising o Query virtual device o Query backend device identification properties. data. o Setup OS device instance. o Open and validate backend device. o Publish backend features and transport parameters. | | V XenbusStateInitWait o Query backend features and transport parameters. o Allocate and initialize the request ring. There is no problem with this yet, but it is an violation of the design and furthermore it would not allow frontend/backend to negotiate 'multi-page' and 'multi-queue' features. Changes in v2: - Re-write the commit message to be more clear. Signed-off-by: Bob Liu Acked-by: Roger Pau Monné Signed-off-by: Konrad Rzeszutek Wilk --- drivers/block/xen-blkfront.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 2c61cf8c6f61..88e23fd8c7f3 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1430,13 +1430,6 @@ static int blkfront_probe(struct xenbus_device *dev, info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); dev_set_drvdata(&dev->dev, info); - err = talk_to_blkback(dev, info); - if (err) { - kfree(info); - dev_set_drvdata(&dev->dev, NULL); - return err; - } - return 0; } @@ -1906,8 +1899,13 @@ static void blkback_changed(struct xenbus_device *dev, dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state); switch (backend_state) { - case XenbusStateInitialising: case XenbusStateInitWait: + if (talk_to_blkback(dev, info)) { + kfree(info); + dev_set_drvdata(&dev->dev, NULL); + break; + } + case XenbusStateInitialising: case XenbusStateInitialised: case XenbusStateReconfiguring: case XenbusStateReconfigured: -- 2.11.0