For regular files, we always get BDRV_REQ_ZERO_WRITE behaviour from the
OS, so we can advertise the flag and just ignore it.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Reviewed-by: Alberto Garcia <be...@igalia.com>
Reviewed-by: Max Reitz <mre...@redhat.com>
---
block/file-posix.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/block/file-posix.c b/block/file-posix.c
index 53f475ed61..1dca220a81 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -702,6 +702,10 @@ static int raw_open_common(BlockDriverState *bs, QDict
*options,
#endif
bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK;
+ if (S_ISREG(st.st_mode)) {
+ /* When extending regular files, we get zeros from the OS */
+ bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
+ }
ret = 0;
fail:
if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) {
--
2.25.3
