Commit 5c8cab48 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

block: Use BdrvChild callbacks for change_media/resize 



We want to get rid of BlockDriverState.blk in order to allow multiple
BlockBackends per BDS. Converting the device callbacks in block.c (which
assume a single BlockBackend) to per-child callbacks gets us rid of the
first few instances.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
parent cbe1beb7

block.c

+26 −13
Original line number Diff line number Diff line
@@ -1214,6 +1214,27 @@ void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child) 
    bdrv_root_unref_child(child);

}





static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load)

{

    BdrvChild *c;

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

        if (c->role->change_media) {

            c->role->change_media(c, load);

        }

    }

}



static void bdrv_parent_cb_resize(BlockDriverState *bs)

{

    BdrvChild *c;

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

        if (c->role->resize) {

            c->role->resize(c);

        }

    }

}



/*

 * Sets the backing file link of a BDS. A new reference is created; callers

 * which don't need their own reference any more must call bdrv_unref().
@@ -1673,9 +1694,7 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, 
    }



    if (!bdrv_key_required(bs)) {

        if (bs->blk) {

            blk_dev_change_media_cb(bs->blk, true);

        }

        bdrv_parent_cb_change_media(bs, true);

    } else if (!runstate_check(RUN_STATE_PRELAUNCH)

               && !runstate_check(RUN_STATE_INMIGRATE)

               && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */
@@ -2121,9 +2140,7 @@ static void bdrv_close(BlockDriverState *bs) 
    bdrv_release_named_dirty_bitmaps(bs);

    assert(QLIST_EMPTY(&bs->dirty_bitmaps));



    if (bs->blk) {

        blk_dev_change_media_cb(bs->blk, false);

    }

    bdrv_parent_cb_change_media(bs, false);



    if (bs->drv) {

        BdrvChild *child, *next;
@@ -2574,9 +2591,7 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset) 
    if (ret == 0) {

        ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);

        bdrv_dirty_bitmap_truncate(bs);

        if (bs->blk) {

            blk_dev_resize_cb(bs->blk);

        }

        bdrv_parent_cb_resize(bs);

    }

    return ret;

}
@@ -2686,11 +2701,9 @@ int bdrv_set_key(BlockDriverState *bs, const char *key) 
    if (ret < 0) {

        bs->valid_key = 0;

    } else if (!bs->valid_key) {

        bs->valid_key = 1;

        if (bs->blk) {

        /* call the change callback now, we skipped it on open */

            blk_dev_change_media_cb(bs->blk, true);

        }

        bs->valid_key = 1;

        bdrv_parent_cb_change_media(bs, true);

    }

    return ret;

}

block/block-backend.c

+14 −1
Original line number Diff line number Diff line
@@ -94,9 +94,15 @@ static void blk_root_inherit_options(int *child_flags, QDict *child_options, 
static void blk_root_drained_begin(BdrvChild *child);

static void blk_root_drained_end(BdrvChild *child);



static void blk_root_change_media(BdrvChild *child, bool load);

static void blk_root_resize(BdrvChild *child);



static const BdrvChildRole child_root = {

    .inherit_options    = blk_root_inherit_options,



    .change_media       = blk_root_change_media,

    .resize             = blk_root_resize,



    .drained_begin      = blk_root_drained_begin,

    .drained_end        = blk_root_drained_end,

};
@@ -556,6 +562,11 @@ void blk_dev_change_media_cb(BlockBackend *blk, bool load) 
    }

}



static void blk_root_change_media(BdrvChild *child, bool load)

{

    blk_dev_change_media_cb(child->opaque, load);

}



/*

 * Does @blk's attached device model have removable media?

 * %true if no device model is attached.
@@ -610,8 +621,10 @@ bool blk_dev_is_medium_locked(BlockBackend *blk) 
/*

 * Notify @blk's attached device model of a backend size change.

 */

void blk_dev_resize_cb(BlockBackend *blk)

static void blk_root_resize(BdrvChild *child)

{

    BlockBackend *blk = child->opaque;



    if (blk->dev_ops && blk->dev_ops->resize_cb) {

        blk->dev_ops->resize_cb(blk->dev_opaque);

    }

include/block/block_int.h

+3 −1
Original line number Diff line number Diff line
@@ -365,6 +365,9 @@ struct BdrvChildRole { 
    void (*inherit_options)(int *child_flags, QDict *child_options,

                            int parent_flags, QDict *parent_options);



    void (*change_media)(BdrvChild *child, bool load);

    void (*resize)(BdrvChild *child);



    /*

     * If this pair of functions is implemented, the parent doesn't issue new

     * requests after returning from .drained_begin() until .drained_end() is
@@ -722,7 +725,6 @@ bool blk_dev_has_tray(BlockBackend *blk); 
void blk_dev_eject_request(BlockBackend *blk, bool force);

bool blk_dev_is_tray_open(BlockBackend *blk);

bool blk_dev_is_medium_locked(BlockBackend *blk);

void blk_dev_resize_cb(BlockBackend *blk);



void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);

bool bdrv_requests_pending(BlockDriverState *bs);