From 529b4b3328e96f55ae0a44d1293616f426077a0b 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 d4ce380..9100862 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -112,6 +112,7 @@ struct XenBlkDev { int requests_inflight; int requests_finished; + gboolean cache_unsafe; /* Persistent grants extension */ gboolean feature_discard; gboolean feature_persistent; @@ -793,6 +794,16 @@ 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); @@ -864,6 +875,7 @@ static int blk_init(struct XenDevice *xendev) xenstore_write_be_int(&blkdev->xendev, "info", info); blk_parse_discard(blkdev); + blk_parse_cache_unsafe(blkdev); g_free(directiosafe); return 0; @@ -906,6 +918,9 @@ 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);