Commit df827336 authored by Alberto Garcia's avatar Alberto Garcia Committed by Kevin Wolf
Browse files

block: Freeze the backing chain for the duration of the commit job 



Signed-off-by: default avatarAlberto Garcia <berto@igalia.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 2cad1ebe

block/commit.c

+16 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ typedef struct CommitBlockJob { 
    BlockDriverState *base_bs;

    BlockdevOnError on_error;

    bool base_read_only;

    bool chain_frozen;

    char *backing_file_str;

} CommitBlockJob;
@@ -68,6 +69,9 @@ static int commit_prepare(Job *job) 
{

    CommitBlockJob *s = container_of(job, CommitBlockJob, common.job);



    bdrv_unfreeze_backing_chain(s->commit_top_bs, s->base_bs);

    s->chain_frozen = false;



    /* Remove base node parent that still uses BLK_PERM_WRITE/RESIZE before

     * the normal backing chain can be restored. */

    blk_unref(s->base);
@@ -84,6 +88,10 @@ static void commit_abort(Job *job) 
    CommitBlockJob *s = container_of(job, CommitBlockJob, common.job);

    BlockDriverState *top_bs = blk_bs(s->top);



    if (s->chain_frozen) {

        bdrv_unfreeze_backing_chain(s->commit_top_bs, s->base_bs);

    }



    /* Make sure commit_top_bs and top stay around until bdrv_replace_node() */

    bdrv_ref(top_bs);

    bdrv_ref(s->commit_top_bs);
@@ -330,6 +338,11 @@ void commit_start(const char *job_id, BlockDriverState *bs, 
        }

    }



    if (bdrv_freeze_backing_chain(commit_top_bs, base, errp) < 0) {

        goto fail;

    }

    s->chain_frozen = true;



    ret = block_job_add_bdrv(&s->common, "base", base, 0, BLK_PERM_ALL, errp);

    if (ret < 0) {

        goto fail;
@@ -362,6 +375,9 @@ void commit_start(const char *job_id, BlockDriverState *bs, 
    return;



fail:

    if (s->chain_frozen) {

        bdrv_unfreeze_backing_chain(commit_top_bs, base);

    }

    if (s->base) {

        blk_unref(s->base);

    }