There is already a barrier in AIO_WAIT_WHILE_INTERNAL(), thus the qatomic_mb_read() is not adding anything.
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- block/block-backend.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index 55efc735b442..5566ea059d55 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1845,7 +1845,7 @@ void blk_drain(BlockBackend *blk) /* We may have -ENOMEDIUM completions in flight */ AIO_WAIT_WHILE(blk_get_aio_context(blk), - qatomic_mb_read(&blk->in_flight) > 0); + qatomic_read(&blk->in_flight) > 0); if (bs) { bdrv_drained_end(bs); @@ -1867,7 +1867,7 @@ void blk_drain_all(void) aio_context_acquire(ctx); /* We may have -ENOMEDIUM completions in flight */ - AIO_WAIT_WHILE(ctx, qatomic_mb_read(&blk->in_flight) > 0); + AIO_WAIT_WHILE(ctx, qatomic_read(&blk->in_flight) > 0); aio_context_release(ctx); } -- 2.40.0