BlockDriver->bdrv_io_plug is categorized as IO callback, and it currently doesn't run in a coroutine. This makes very difficult to add the graph rdlock, since the callback traverses the block nodes graph.
The only caller of this function is blk_plug, therefore make blk_plug a generated_co_wrapper_simple, so that it always creates a new coroutine, and then make bdrv_plug coroutine_fn. Signed-off-by: Emanuele Giuseppe Esposito <eespo...@redhat.com> --- block/block-backend.c | 5 +++-- block/io.c | 5 +++-- include/block/block-io.h | 3 ++- include/block/block_int-common.h | 4 ++-- include/sysemu/block-backend-io.h | 4 +++- 5 files changed, 13 insertions(+), 8 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index 75e2f2124f..826a936beb 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -2329,13 +2329,14 @@ void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify) notifier_list_add(&blk->insert_bs_notifiers, notify); } -void blk_io_plug(BlockBackend *blk) +void coroutine_fn blk_co_io_plug(BlockBackend *blk) { BlockDriverState *bs = blk_bs(blk); IO_CODE(); + assert_bdrv_graph_readable(); if (bs) { - bdrv_io_plug(bs); + bdrv_co_io_plug(bs); } } diff --git a/block/io.c b/block/io.c index 11d2c5dcde..d3b8c1e4b2 100644 --- a/block/io.c +++ b/block/io.c @@ -3068,13 +3068,14 @@ void *qemu_try_blockalign0(BlockDriverState *bs, size_t size) return mem; } -void bdrv_io_plug(BlockDriverState *bs) +void coroutine_fn bdrv_co_io_plug(BlockDriverState *bs) { BdrvChild *child; IO_CODE(); + assert_bdrv_graph_readable(); QLIST_FOREACH(child, &bs->children, next) { - bdrv_io_plug(child->bs); + bdrv_co_io_plug(child->bs); } if (qatomic_fetch_inc(&bs->io_plugged) == 0) { diff --git a/include/block/block-io.h b/include/block/block-io.h index 176e3cc734..a045643b26 100644 --- a/include/block/block-io.h +++ b/include/block/block-io.h @@ -215,7 +215,8 @@ void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co); AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c); -void bdrv_io_plug(BlockDriverState *bs); +void coroutine_fn bdrv_co_io_plug(BlockDriverState *bs); + void bdrv_io_unplug(BlockDriverState *bs); bool coroutine_fn bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs, diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index b509855c19..ed96bc3241 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -785,8 +785,8 @@ struct BlockDriver { void coroutine_fn (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event); - /* io queue for linux-aio */ - void (*bdrv_io_plug)(BlockDriverState *bs); + /* io queue for linux-aio. Called with graph rdlock taken. */ + void coroutine_fn (*bdrv_io_plug)(BlockDriverState *bs); void (*bdrv_io_unplug)(BlockDriverState *bs); /** diff --git a/include/sysemu/block-backend-io.h b/include/sysemu/block-backend-io.h index dd8566ee69..703fcc3ac5 100644 --- a/include/sysemu/block-backend-io.h +++ b/include/sysemu/block-backend-io.h @@ -87,7 +87,9 @@ void blk_iostatus_set_err(BlockBackend *blk, int error); int blk_get_max_iov(BlockBackend *blk); int blk_get_max_hw_iov(BlockBackend *blk); -void blk_io_plug(BlockBackend *blk); +void coroutine_fn blk_co_io_plug(BlockBackend *blk); +void generated_co_wrapper_simple blk_io_plug(BlockBackend *blk); + void blk_io_unplug(BlockBackend *blk); AioContext *blk_get_aio_context(BlockBackend *blk); BlockAcctStats *blk_get_stats(BlockBackend *blk); -- 2.31.1