From f7ef38dd1310d7d9db76d0aa16899cbc5744f36d Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Fri, 3 Sep 2021 13:27:59 +0300 Subject: block: use int64_t instead of uint64_t in driver read handlers We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver read handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_preadv() in block/io.c, passes int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_load_vmstate() does bdrv_check_qiov_request(). do_perform_cow_read() has uint64_t argument. And a lot of things in qcow2 driver are uint64_t, so converting it is big job. But we must not work with requests that don't satisfy bdrv_check_qiov_request(), so let's just assert it here. Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done The only one such caller: QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); ... ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); in tests/unit/test-bdrv-drain.c, and it's OK obviously. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake [eblake: fix typos] Signed-off-by: Eric Blake --- block/copy-on-read.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'block/copy-on-read.c') diff --git a/block/copy-on-read.c b/block/copy-on-read.c index c428682..d34add4 100644 --- a/block/copy-on-read.c +++ b/block/copy-on-read.c @@ -128,10 +128,10 @@ static int64_t cor_getlength(BlockDriverState *bs) static int coroutine_fn cor_co_preadv_part(BlockDriverState *bs, - uint64_t offset, uint64_t bytes, + int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset, - int flags) + BdrvRequestFlags flags) { int64_t n; int local_flags; -- cgit v1.1