From 49ca6259131c6b0555845fcac3e34467c8ac37eb Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Mon, 10 Apr 2017 21:00:50 +0800 Subject: [PATCH] block: Fix bdrv_co_flush early return bdrv_inc_in_flight and bdrv_dec_in_flight are mandatory for BDRV_POLL_WHILE to work, even for the shortcut case where flush is unnecessary. Move the if block to below bdrv_dec_in_flight, and BTW fix the variable declaration position. Signed-off-by: Fam Zheng Acked-by: Stefan Hajnoczi Reviewed-by: Kevin Wolf Reviewed-by: Paolo Bonzini --- block/io.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/block/io.c b/block/io.c index 00e45ca219..bae6947032 100644 --- a/block/io.c +++ b/block/io.c @@ -2278,16 +2278,17 @@ static void coroutine_fn bdrv_flush_co_entry(void *opaque) int coroutine_fn bdrv_co_flush(BlockDriverState *bs) { - int ret; - - if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs) || - bdrv_is_sg(bs)) { - return 0; - } + int current_gen; + int ret = 0; bdrv_inc_in_flight(bs); - int current_gen = bs->write_gen; + if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs) || + bdrv_is_sg(bs)) { + goto early_exit; + } + + current_gen = bs->write_gen; /* Wait until any previous flushes are completed */ while (bs->active_flush_req) { @@ -2370,6 +2371,7 @@ out: /* Return value is ignored - it's ok if wait queue is empty */ qemu_co_queue_next(&bs->flush_queue); +early_exit: bdrv_dec_in_flight(bs); return ret; }