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 <ebl...@redhat.com>
---
block/nfs.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/block/nfs.c b/block/nfs.c
index 2393fbfe6bcc..b93989265630 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -623,6 +623,9 @@ 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;
+ }
ret = 0;
return ret;
}
--
2.26.2
