From f6801b83d0e77ca025867800d805ee80f6bda938 Mon Sep 17 00:00:00 2001 From: Jeff Cody Date: Tue, 27 Mar 2012 16:30:19 -0400 Subject: [PATCH] block: bdrv_append() fixes A few fixups for bdrv_append(): The new bs (bs_new) passed into bdrv_append() should be anonymous. Rather than call bdrv_make_anon() to enforce this, use an assert to catch when a caller is passing in a bs_new that is not anonymous. Also, the new top layer should have its backing_format reflect the original top's format. And last, after the swap of bs contents, the device_name will have been copied down. This needs to be cleared to reflect the anonymity of the bs that was pushed down. Signed-off-by: Jeff Cody Signed-off-by: Kevin Wolf --- block.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index 33630ebacc..b3117ef3f1 100644 --- a/block.c +++ b/block.c @@ -892,14 +892,16 @@ void bdrv_make_anon(BlockDriverState *bs) * This will modify the BlockDriverState fields, and swap contents * between bs_new and bs_top. Both bs_new and bs_top are modified. * + * bs_new is required to be anonymous. + * * This function does not create any image files. */ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) { BlockDriverState tmp; - /* the new bs must not be in bdrv_states */ - bdrv_make_anon(bs_new); + /* bs_new must be anonymous */ + assert(bs_new->device_name[0] == '\0'); tmp = *bs_new; @@ -944,11 +946,18 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) * swapping bs_new and bs_top contents. */ tmp.backing_hd = bs_new; pstrcpy(tmp.backing_file, sizeof(tmp.backing_file), bs_top->filename); + bdrv_get_format(bs_top, tmp.backing_format, sizeof(tmp.backing_format)); /* swap contents of the fixed new bs and the current top */ *bs_new = *bs_top; *bs_top = tmp; + /* device_name[] was carried over from the old bs_top. bs_new + * shouldn't be in bdrv_states, so we need to make device_name[] + * reflect the anonymity of bs_new + */ + bs_new->device_name[0] = '\0'; + /* clear the copied fields in the new backing file */ bdrv_detach_dev(bs_new, bs_new->dev);