From 38cb18f5b71428fb8a3e3759ac8fa21ac70cb1b5 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Mon, 26 Oct 2015 21:39:07 +0100 Subject: [PATCH] block: Add functions for inheriting a BBRS 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 Signed-off-by: Kevin Wolf --- block/block-backend.c | 27 +++++++++++++++++++++++++++ include/sysemu/block-backend.h | 2 ++ 2 files changed, 29 insertions(+) diff --git a/block/block-backend.c b/block/block-backend.c index 878c448855..7d495395de 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -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; diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index 14a6d32bb2..40e315b5bb 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -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); -- 2.11.4.GIT