From: Eric Blake <[email protected]> Our .bdrv_has_zero_init_truncate returns 1 if we detect that the OS always 0-fills; we can use that same knowledge to implement BDRV_REQ_ZERO_WRITE by ignoring it when the OS gives it to us for free.
Signed-off-by: Eric Blake <[email protected]> Message-Id: <[email protected]> Signed-off-by: Kevin Wolf <[email protected]> --- block/nfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/nfs.c b/block/nfs.c index 385d756e1d..76daa7c9f6 100644 --- a/block/nfs.c +++ b/block/nfs.c @@ -620,6 +620,9 @@ static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags, } bs->total_sectors = ret; + if (client->has_zero_init) { + bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; + } return 0; } -- 2.25.3
