Commit dde33812 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

block: Add bdrv_has_blk() 



In many cases we just want to know whether a BDS has at least one BB
attached, without needing to know the exact BB that is attached. In
contrast to bs->blk, this is still a valid question when more than one
BB can be attached, so just answer it by checking the parents list.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
parent 91c6e4b7

block/block-backend.c

+17 −0
Original line number Diff line number Diff line
@@ -394,6 +394,23 @@ BlockDriverState *blk_bs(BlockBackend *blk) 
    return blk->root ? blk->root->bs : NULL;

}



/*

 * Returns true if @bs has an associated BlockBackend.

 */

bool bdrv_has_blk(BlockDriverState *bs)

{

    BdrvChild *child;

    QLIST_FOREACH(child, &bs->parents, next_parent) {

        if (child->role == &child_root) {

            assert(bs->blk);

            return true;

        }

    }



    assert(!bs->blk);

    return false;

}



/*

 * Return @blk's DriveInfo if any, else null.

 */

include/sysemu/block-backend.h

+1 −0
Original line number Diff line number Diff line
@@ -99,6 +99,7 @@ BlockBackend *blk_by_public(BlockBackendPublic *public); 
BlockDriverState *blk_bs(BlockBackend *blk);

void blk_remove_bs(BlockBackend *blk);

void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs);

bool bdrv_has_blk(BlockDriverState *bs);



void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);

void blk_iostatus_enable(BlockBackend *blk);