Commit fe5258a5 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

block-backend: Add .drained_poll callback 



A bdrv_drain operation must ensure that all parents are quiesced, this
includes BlockBackends. Otherwise, callbacks called by requests that are
completed on the BDS layer, but not quite yet on the BlockBackend layer
could still create new requests.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
parent aa1361d5

block/block-backend.c

+9 −0
Original line number Diff line number Diff line
@@ -121,6 +121,7 @@ static void blk_root_inherit_options(int *child_flags, QDict *child_options, 
    abort();

}

static void blk_root_drained_begin(BdrvChild *child);

static bool blk_root_drained_poll(BdrvChild *child);

static void blk_root_drained_end(BdrvChild *child);



static void blk_root_change_media(BdrvChild *child, bool load);
@@ -294,6 +295,7 @@ static const BdrvChildRole child_root = { 
    .get_parent_desc    = blk_root_get_parent_desc,



    .drained_begin      = blk_root_drained_begin,

    .drained_poll       = blk_root_drained_poll,

    .drained_end        = blk_root_drained_end,



    .activate           = blk_root_activate,
@@ -2189,6 +2191,13 @@ static void blk_root_drained_begin(BdrvChild *child) 
    }

}



static bool blk_root_drained_poll(BdrvChild *child)

{

    BlockBackend *blk = child->opaque;

    assert(blk->quiesce_counter);

    return !!blk->in_flight;

}



static void blk_root_drained_end(BdrvChild *child)

{

    BlockBackend *blk = child->opaque;