From: Kevin Wolf Date: Fri, 22 Nov 2019 15:57:48 +0000 (+0100) Subject: qcow2: Declare BDRV_REQ_NO_FALLBACK supported X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3b65081638c68be1c6ed08635c8acd99f32320ac;p=qemu.git qcow2: Declare BDRV_REQ_NO_FALLBACK supported In the common case, qcow2_co_pwrite_zeroes() already only modifies metadata case, so we're fine with or without BDRV_REQ_NO_FALLBACK set. The only exception is when using an external data file, where the request is passed down to the block driver of the external data file. We are forwarding the BDRV_REQ_NO_FALLBACK flag there, though, so this is fine, too. Declare the flag supported therefore. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake Reviewed-by: Max Reitz Reviewed-by: Alberto Garcia --- diff --git a/block/qcow2.c b/block/qcow2.c index 7c18721741..de0e89cf25 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1722,7 +1722,8 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, } } - bs->supported_zero_flags = header.version >= 3 ? BDRV_REQ_MAY_UNMAP : 0; + bs->supported_zero_flags = header.version >= 3 ? + BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0; /* Repair image if dirty */ if (!(flags & (BDRV_O_CHECK | BDRV_O_INACTIVE)) && !bs->read_only &&