From: Max Reitz <mre...@redhat.com> When bdrv_close_all() is called, instead of force-closing all root BlockDriverStates, it is better to just drop the reference from all BlockBackends and let them be closed automatically. This prevents BDS from getting closed that are still referenced by other BDS, which may result in loss of cached data.
This patch adds a function for doing that, but does not yet incorporate it in bdrv_close_all(). Signed-off-by: Max Reitz <mre...@redhat.com> Reviewed-by: Kevin Wolf <kw...@redhat.com> Signed-off-by: Kevin Wolf <kw...@redhat.com> --- block/block-backend.c | 15 +++++++++++++++ include/sysemu/block-backend.h | 1 + 2 files changed, 16 insertions(+) diff --git a/block/block-backend.c b/block/block-backend.c index 7f5ad59..ebdf78a 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -223,6 +223,21 @@ void blk_unref(BlockBackend *blk) } } +void blk_remove_all_bs(void) +{ + BlockBackend *blk; + + QTAILQ_FOREACH(blk, &blk_backends, link) { + AioContext *ctx = blk_get_aio_context(blk); + + aio_context_acquire(ctx); + if (blk->bs) { + blk_remove_bs(blk); + } + aio_context_release(ctx); + } +} + /* * Return the BlockBackend after @blk. * If @blk is null, return the first one. diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index ae4efb4..ec30331 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -68,6 +68,7 @@ BlockBackend *blk_new_open(const char *name, const char *filename, int blk_get_refcnt(BlockBackend *blk); void blk_ref(BlockBackend *blk); void blk_unref(BlockBackend *blk); +void blk_remove_all_bs(void); const char *blk_name(BlockBackend *blk); BlockBackend *blk_by_name(const char *name); BlockBackend *blk_next(BlockBackend *blk); -- 1.8.3.1