block-backend: Add blk_set_bs()

It allows changing the BlockDriverState that a BlockBackend points to.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Kevin Wolf 2015-09-17 13:01:50 +02:00
parent 439db28cf9
commit a2d6190048
2 changed files with 19 additions and 0 deletions

View File

@ -238,6 +238,23 @@ BlockDriverState *blk_bs(BlockBackend *blk)
return blk->bs;
}
/*
* Changes the BlockDriverState attached to @blk
*/
void blk_set_bs(BlockBackend *blk, BlockDriverState *bs)
{
bdrv_ref(bs);
if (blk->bs) {
blk->bs->blk = NULL;
bdrv_unref(blk->bs);
}
assert(bs->blk == NULL);
blk->bs = bs;
bs->blk = blk;
}
/*
* Return @blk's DriveInfo if any, else null.
*/

View File

@ -659,6 +659,8 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
BlockCompletionFunc *cb, void *opaque,
Error **errp);
void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);
void blk_dev_change_media_cb(BlockBackend *blk, bool load);
bool blk_dev_has_removable_media(BlockBackend *blk);
void blk_dev_eject_request(BlockBackend *blk, bool force);