qemu /
qemu /
37e9403ea87a473f96744af7583dbb3eaef8d0f6 block/io: support int64_t bytes in bdrv_co_p{read,write}v_part()
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, prepare bdrv_co_preadv_part() and bdrv_co_pwritev_part() and their
remaining dependencies now.
bdrv_pad_request() is updated simultaneously, as pointer to bytes passed
to it both from bdrv_co_pwritev_part() and bdrv_co_preadv_part().
So, all callers of bdrv_pad_request() are updated to pass 64bit bytes.
bdrv_pad_request() is already good for 64bit requests, add
corresponding assertion.
Look at bdrv_co_preadv_part() and bdrv_co_pwritev_part().
Type is widening, so callers are safe. Let's look inside the functions.
In bdrv_co_preadv_part() and bdrv_aligned_pwritev() we only pass bytes
to other already int64_t interfaces (and some obviously safe
calculations), it's OK.
In bdrv_co_do_zero_pwritev() aligned_bytes may become large now, still
it's passed to bdrv_aligned_pwritev which supports int64_t bytes.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-15-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
3 files changed
