From b0db2003f907e0dc62b0a13c6b3f3b0a1d681675 Mon Sep 17 00:00:00 2001 From: Naphtali Sprei Date: Wed, 7 Apr 2010 16:44:22 -0300 Subject: [PATCH 11/21] block: flush backing_hd in the right place RH-Author: Naphtali Sprei Message-id: <1270658667-14294-12-git-send-email-nsprei@redhat.com> Patchwork-id: 8445 O-Subject: [RHEL6 kvm PATCH v3 rebase 11/16] block: flush backing_hd in the right place Bugzilla: 537164 RH-Acked-by: Daniel P. Berrange RH-Acked-by: Christoph Hellwig RH-Acked-by: Juan Quintela RH-Acked-by: Kevin Wolf From: Christoph Hellwig The backing device is only modified from bdrv_commit. So instead of flushing it every time bdrv_flush is called for the front-end device only flush it after we're written data to it in bdrv_commit. BZ: https://bugzilla.redhat.com/show_bug.cgi?id=537164 upstream commit: 3f5075ae63b6dc1de9428d028a4d28fc98e7fdff Signed-off-by: Christoph Hellwig Signed-off-by: Anthony Liguori Signed-off-by: Naphtali Sprei --- block.c | 17 +++++++---------- 1 files changed, 7 insertions(+), 10 deletions(-) Signed-off-by: Eduardo Habkost --- block.c | 17 +++++++---------- 1 files changed, 7 insertions(+), 10 deletions(-) diff --git a/block.c b/block.c index bed5b88..0675aef 100644 --- a/block.c +++ b/block.c @@ -605,6 +605,12 @@ int bdrv_commit(BlockDriverState *bs) if (drv->bdrv_make_empty) return drv->bdrv_make_empty(bs); + /* + * Make sure all data we wrote to the backing device is actually + * stable on disk. + */ + if (bs->backing_hd) + bdrv_flush(bs->backing_hd); return 0; } @@ -1124,12 +1130,8 @@ const char *bdrv_get_device_name(BlockDriverState *bs) void bdrv_flush(BlockDriverState *bs) { - if (!bs->drv) - return; - if (bs->drv->bdrv_flush) + if (bs->drv && bs->drv->bdrv_flush) bs->drv->bdrv_flush(bs); - if (bs->backing_hd) - bdrv_flush(bs->backing_hd); } void bdrv_flush_all(void) @@ -1836,11 +1838,6 @@ BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs, if (!drv) return NULL; - - /* - * Note that unlike bdrv_flush the driver is reponsible for flushing a - * backing image if it exists. - */ return drv->bdrv_aio_flush(bs, cb, opaque); } -- 1.7.0.3