Re: [PATCH v5 5/9] raw-format: Support BDRV_REQ_ZERO_WRITE for truncate

[Eric Blake]

On 4/22/20 10:21 AM, Kevin Wolf wrote:

The raw format driver can simply forward the flag and let its bs->file
child take care of actually providing the zeros.

Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
  block/raw-format.c | 4 +++-
  1 file changed, 3 insertions(+), 1 deletion(-)

Reviewed-by: Eric Blake <ebl...@redhat.com>

diff --git a/block/raw-format.c b/block/raw-format.c
index 3465c9a865..351f2d91c6 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -387,7 +387,7 @@ static int coroutine_fn raw_co_truncate(BlockDriverState 
*bs, int64_t offset,

s->size = offset;

      offset += s->offset;
-    return bdrv_co_truncate(bs->file, offset, exact, prealloc, 0, errp);
+    return bdrv_co_truncate(bs->file, offset, exact, prealloc, flags, errp);
  }

static void raw_eject(BlockDriverState *bs, bool eject_flag)

@@ -445,6 +445,8 @@ static int raw_open(BlockDriverState *bs, QDict *options, 
int flags,
      bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
          ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
              bs->file->bs->supported_zero_flags);
+    bs->supported_truncate_flags = bs->file->bs->supported_truncate_flags &
+                                   BDRV_REQ_ZERO_WRITE;

if (bs->probed && !bdrv_is_read_only(bs)) {

          bdrv_refresh_filename(bs->file->bs);

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org