rbd: Support BDRV_REQ_ZERO_WRITE for truncate

Our .bdrv_has_zero_init_truncate always returns 1 because rbd always
0-fills; we can use that same knowledge to implement
BDRV_REQ_ZERO_WRITE by ignoring it.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200428202905.770727-5-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Eric Blake 2020-04-28 15:29:00 -05:00 committed by Kevin Wolf
parent 8f23aaf5d6
commit 2f98910d5b

View file

@ -817,6 +817,9 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags,
}
}
/* When extending regular files, we get zeros from the OS */
bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
r = 0;
goto out;