From: Thibaut LAURENT Date: Fri, 25 Oct 2013 00:15:07 +0000 (+0200) Subject: block: Disable BDRV_O_COPY_ON_READ for the backing file X-Git-Tag: qemu-xen-4.5.0-rc1~385^2~15 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=87a5debd3161d24a7d4c685e3c0d8765b5d92a74;p=qemu-upstream-4.5-testing.git block: Disable BDRV_O_COPY_ON_READ for the backing file Since commit 0ebd24e0a203cf2852c310b59fbe050190dc6c8c, bdrv_open_common will throw an error when trying to open a file read-only with the BDRV_O_COPY_ON_READ flag set. Although BDRV_O_RDWR is unset for the backing files, BDRV_O_COPY_ON_READ is still passed on if copy-on-read was requested for the drive. Let's unset this flag too before opening the backing file, or bdrv_open_common will fail. Signed-off-by: Thibaut LAURENT Reviewed-by: Benoit Canet Reviewed-by: Max Reitz Signed-off-by: Kevin Wolf --- diff --git a/block.c b/block.c index 366999b15..61795fea4 100644 --- a/block.c +++ b/block.c @@ -999,7 +999,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) } /* backing files always opened read-only */ - back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT); + back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | + BDRV_O_COPY_ON_READ); ret = bdrv_open(bs->backing_hd, *backing_filename ? backing_filename : NULL, options,