From: lu zhipeng <luzhipeng@cestc.cn>
we can unmap(discard) blocks for block devices of supporting discard zeros
or regular file.
Signed-off-by: lu zhipeng <luzhipeng@cestc.cn>
---
block/file-posix.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/file-posix.c b/block/file-posix.c
index 48cd096624..c35dbc0d88 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -799,7 +799,8 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
#endif
s->needs_alignment = raw_needs_alignment(bs);
- bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK;
+ bs->supported_zero_flags = s->discard_zeroes ?
+ BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0;
if (S_ISREG(st.st_mode)) {
/* When extending regular files, we get zeros from the OS */
bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
--
2.31.1