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block: bdrv_append() fixes

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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 <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Jeff Cody 2012-03-27 16:30:19 -04:00 committed by Kevin Wolf
parent d68dbee80e
commit f6801b83d0
1 changed files with 11 additions and 2 deletions
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13
block.c
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@ -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);