Commit d8da3cef authored by Max Reitz's avatar Max Reitz
Browse files

block: Add blk_remove_all_bs() 



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: default avatarMax Reitz <mreitz@redhat.com>
Reviewed-by: default avatarKevin Wolf <kwolf@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 9c4218e9

block/block-backend.c

+15 −0
Original line number Diff line number Diff line
@@ -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.

include/sysemu/block-backend.h

+1 −0
Original line number Diff line number Diff line
@@ -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);