From 45783db0ed8628cb9cdb4d3ebbf7471f2f88db9b Mon Sep 17 00:00:00 2001 From: Bruce Rogers Date: Wed, 9 Mar 2016 15:18:11 -0700 Subject: [PATCH] xen_disk: Add suse specific flush disable handling and map to QEMU equiv Add code to read the suse specific suse-diskcache-disable-flush flag out of xenstore, and set the equivalent flag within QEMU. Patch taken from Xen's patch queue, Olaf Hering being the original author. [bsc#879425] Signed-off-by: Bruce Rogers Signed-off-by: Olaf Hering --- hw/block/xen_disk.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index e431bd89e8..dceee88a78 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -113,6 +113,7 @@ struct XenBlkDev { int requests_finished; unsigned int max_requests; + gboolean cache_unsafe; /* Persistent grants extension */ gboolean feature_discard; gboolean feature_persistent; @@ -944,6 +945,16 @@ static void blk_parse_discard(struct XenBlkDev *blkdev) } } +static void blk_parse_cache_unsafe(struct XenBlkDev *blkdev) +{ + int enable; + + blkdev->cache_unsafe = false; + + if (xenstore_read_be_int(&blkdev->xendev, "suse-diskcache-disable-flush", &enable) == 0) + blkdev->cache_unsafe = !!enable; +} + static int blk_init(struct XenDevice *xendev) { struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); @@ -1022,6 +1033,7 @@ static int blk_init(struct XenDevice *xendev) MAX_RING_PAGE_ORDER); blk_parse_discard(blkdev); + blk_parse_cache_unsafe(blkdev); g_free(directiosafe); return 0; @@ -1077,6 +1089,9 @@ static int blk_connect(struct XenDevice *xendev) qflags |= BDRV_O_UNMAP; } + if (blkdev->cache_unsafe) + qflags |= BDRV_O_NO_FLUSH; + /* init qemu block driver */ index = (blkdev->xendev.dev - 202 * 256) / 16; blkdev->dinfo = drive_get(IF_XEN, 0, index);