Newer toolstacks may provide a boolean property "discard-enable" in the backend node. Its purpose is to disable discard for file backed storage to avoid fragmentation. Recognize this setting also for physical storage. If that property exists and is false, do not advertise "feature-discard" to the frontend.
Signed-off-by: Olaf Hering <[email protected]> --- drivers/block/xen-blkback/xenbus.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 9a547e6..a71ecf5 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -481,10 +481,15 @@ static void xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info struct xenbus_device *dev = be->dev; struct xen_blkif *blkif = be->blkif; int err; - int state = 0; + int state = 0, discard_enable; struct block_device *bdev = be->blkif->vbd.bdev; struct request_queue *q = bdev_get_queue(bdev); + err = xenbus_scanf(XBT_NIL, dev->nodename, "discard-enable", "%d", + &discard_enable); + if (err == 1 && !discard_enable) + return; + if (blk_queue_discard(q)) { err = xenbus_printf(xbt, dev->nodename, "discard-granularity", "%u", -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
