@@ -1239,6 +1239,33 @@ void blk_update_root_state(BlockBackend *blk)
}
}
+/*
+ * Applies the information in the root state to the given BlockDriverState. This
+ * does not include the flags which have to be specified for bdrv_open(), use
+ * blk_get_open_flags_from_root_state() to inquire them.
+ */
+void blk_apply_root_state(BlockBackend *blk, BlockDriverState *bs)
+{
+ bs->detect_zeroes = blk->root_state.detect_zeroes;
+ if (blk->root_state.throttle_group) {
+ bdrv_io_limits_enable(bs, blk->root_state.throttle_group);
+ }
+}
+
+/*
+ * Returns the flags to be used for bdrv_open() of a BlockDriverState which is
+ * supposed to inherit the root state.
+ */
+int blk_get_open_flags_from_root_state(BlockBackend *blk)
+{
+ int bs_flags;
+
+ bs_flags = blk->root_state.read_only ? 0 : BDRV_O_RDWR;
+ bs_flags |= blk->root_state.open_flags & ~BDRV_O_RDWR;
+
+ return bs_flags;
+}
+
BlockBackendRootState *blk_get_root_state(BlockBackend *blk)
{
return &blk->root_state;
@@ -167,6 +167,8 @@ void blk_io_unplug(BlockBackend *blk);
BlockAcctStats *blk_get_stats(BlockBackend *blk);
BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
void blk_update_root_state(BlockBackend *blk);
+void blk_apply_root_state(BlockBackend *blk, BlockDriverState *bs);
+int blk_get_open_flags_from_root_state(BlockBackend *blk);
void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
BlockCompletionFunc *cb, void *opaque);
In order to open a BDS which inherits a BB's root state, blk_get_open_flags_from_root_state() is used to inquire the flags to be passed to bdrv_open(), and blk_apply_root_state() is used to apply the remaining state after the BDS has been opened. Signed-off-by: Max Reitz <mreitz@redhat.com> --- block/block-backend.c | 27 +++++++++++++++++++++++++++ include/sysemu/block-backend.h | 2 ++ 2 files changed, 29 insertions(+)