Commit 1f0c461b authored by Kevin Wolf's avatar Kevin Wolf
Browse files

block: Remove BlockDriverState.blk 



This patch removes the remaining users of bs->blk, which will allow us
to have multiple BBs on top of a single BDS. In the meantime, all checks
that are currently in place to prevent the user from creating such
setups can be switched to bdrv_has_blk() instead of accessing BDS.blk.

Future patches can allow them and e.g. enable users to mirror to a block
device that already has a BlockBackend on it.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
parent 79c719b7

block.c

+1 −9
Original line number Diff line number Diff line
@@ -2226,14 +2226,6 @@ static void change_parent_backing_link(BlockDriverState *from, 
{

    BdrvChild *c, *next;



    if (from->blk) {

        /* FIXME We bypass blk_set_bs(), so we need to make these updates

         * manually. The root problem is not in this change function, but the

         * existence of BlockDriverState.blk. */

        to->blk = from->blk;

        from->blk = NULL;

    }



    QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {

        assert(c->role != &child_backing);

        c->bs = to;
@@ -2875,7 +2867,7 @@ const char *bdrv_get_node_name(const BlockDriverState *bs) 
    return bs->node_name;

}



static const char *bdrv_get_parent_name(const BlockDriverState *bs)

const char *bdrv_get_parent_name(const BlockDriverState *bs)

{

    BdrvChild *c;

    const char *name;

block/block-backend.c

+0 −8
Original line number Diff line number Diff line
@@ -152,7 +152,6 @@ BlockBackend *blk_new_with_bs(Error **errp) 
    bs = bdrv_new_root();

    blk->root = bdrv_root_attach_child(bs, "root", &child_root);

    blk->root->opaque = blk;

    bs->blk = blk;

    return blk;

}
@@ -422,12 +421,10 @@ static BlockBackend *bdrv_first_blk(BlockDriverState *bs) 
    BdrvChild *child;

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

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

            assert(bs->blk);

            return child->opaque;

        }

    }



    assert(!bs->blk);

    return NULL;

}
@@ -495,8 +492,6 @@ BlockBackend *blk_by_public(BlockBackendPublic *public) 
 */

void blk_remove_bs(BlockBackend *blk)

{

    assert(blk->root->bs->blk == blk);



    notifier_list_notify(&blk->remove_bs_notifiers, blk);

    if (blk->public.throttle_state) {

        throttle_timers_detach_aio_context(&blk->public.throttle_timers);
@@ -504,7 +499,6 @@ void blk_remove_bs(BlockBackend *blk) 


    blk_update_root_state(blk);



    blk->root->bs->blk = NULL;

    bdrv_root_unref_child(blk->root);

    blk->root = NULL;

}
@@ -514,11 +508,9 @@ void blk_remove_bs(BlockBackend *blk) 
 */

void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs)

{

    assert(!blk->root && !bs->blk);

    bdrv_ref(bs);

    blk->root = bdrv_root_attach_child(bs, "root", &child_root);

    blk->root->opaque = blk;

    bs->blk = blk;



    notifier_list_notify(&blk->insert_bs_notifiers, blk);

    if (blk->public.throttle_state) {

block/mirror.c

+2 −2
Original line number Diff line number Diff line
@@ -468,7 +468,7 @@ static void mirror_exit(BlockJob *job, void *opaque) 


        /* This was checked in mirror_start_job(), but meanwhile one of the

         * nodes could have been newly attached to a BlockBackend. */

        if (to_replace->blk && s->target->blk) {

        if (bdrv_has_blk(to_replace) && bdrv_has_blk(s->target)) {

            error_report("block job: Can't create node with two BlockBackends");

            data->ret = -EINVAL;

            goto out;
@@ -831,7 +831,7 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, 
    } else {

        replaced_bs = bs;

    }

    if (replaced_bs->blk && target->blk) {

    if (bdrv_has_blk(replaced_bs) && bdrv_has_blk(target)) {

        error_setg(errp, "Can't create node with two BlockBackends");

        return;

    }

blockdev.c

+8 −8
Original line number Diff line number Diff line
@@ -1776,9 +1776,9 @@ static void external_snapshot_prepare(BlkActionState *common, 
        return;

    }



    if (state->new_bs->blk != NULL) {

    if (bdrv_has_blk(state->new_bs)) {

        error_setg(errp, "The snapshot is already in use by %s",

                   blk_name(state->new_bs->blk));

                   bdrv_get_parent_name(state->new_bs));

        return;

    }
@@ -2494,9 +2494,9 @@ void qmp_x_blockdev_insert_medium(const char *device, const char *node_name, 
        return;

    }



    if (bs->blk) {

    if (bdrv_has_blk(bs)) {

        error_setg(errp, "Node '%s' is already in use by '%s'", node_name,

                   blk_name(bs->blk));

                   bdrv_get_parent_name(bs));

        return;

    }
@@ -3441,7 +3441,7 @@ static void blockdev_mirror_common(BlockDriverState *bs, 
    if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_MIRROR_TARGET, errp)) {

        return;

    }

    if (target->blk) {

    if (bdrv_has_blk(target)) {

        error_setg(errp, "Cannot mirror to an attached block device");

        return;

    }
@@ -4030,15 +4030,15 @@ void qmp_x_blockdev_del(bool has_id, const char *id, 
        bs = blk_bs(blk);

        aio_context = blk_get_aio_context(blk);

    } else {

        blk = NULL;

        bs = bdrv_find_node(node_name);

        if (!bs) {

            error_setg(errp, "Cannot find node %s", node_name);

            return;

        }

        blk = bs->blk;

        if (blk) {

        if (bdrv_has_blk(bs)) {

            error_setg(errp, "Node %s is in use by %s",

                       node_name, blk_name(blk));

                       node_name, bdrv_get_parent_name(bs));

            return;

        }

        aio_context = bdrv_get_aio_context(bs);

include/block/block_int.h

+1 −2
Original line number Diff line number Diff line
@@ -418,8 +418,6 @@ struct BlockDriverState { 
    BlockDriver *drv; /* NULL means no media */

    void *opaque;



    BlockBackend *blk;          /* owning backend, if any */



    AioContext *aio_context; /* event loop used for fd handlers, timers, etc */

    /* long-running tasks intended to always use the same AioContext as this

     * BDS may register themselves in this list to be notified of changes
@@ -724,6 +722,7 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, 
                                  const BdrvChildRole *child_role);

void bdrv_root_unref_child(BdrvChild *child);



const char *bdrv_get_parent_name(const BlockDriverState *bs);

void blk_dev_change_media_cb(BlockBackend *blk, bool load);

bool blk_dev_has_removable_media(BlockBackend *blk);

bool blk_dev_has_tray(BlockBackend *blk);