From dde33812a83b9c55b180a85411bfc4d6c39e8b11 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Mon, 29 Feb 2016 10:50:38 +0100 Subject: [PATCH] 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: Kevin Wolf Reviewed-by: Max Reitz --- block/block-backend.c | 17 +++++++++++++++++ include/sysemu/block-backend.h | 1 + 2 files changed, 18 insertions(+) diff --git a/block/block-backend.c b/block/block-backend.c index 8d6fc77b26..9dcac9792f 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -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. */ diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index 79f39b889e..44a222d884 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -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);