From: Thibaut LAURENT <thibaut.laur...@gmail.com>
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 <thibaut.laur...@gmail.com>
Reviewed-by: Benoit Canet <ben...@irqsave.net>
Reviewed-by: Max Reitz <mre...@redhat.com>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block.c b/block.c
index 366999b..61795fe 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,
--
1.8.1.4
