On 4/30/20 6:10 AM, Vladimir Sementsov-Ogievskiy wrote:
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

So, convert tracked requests now.

Series: 64bit-block-status
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>

  static void tracked_request_begin(BdrvTrackedRequest *req,
                                    BlockDriverState *bs,
                                    int64_t offset,
-                                  uint64_t bytes,
+                                  int64_t bytes,
                                    enum BdrvTrackedRequestType type)
-    assert(bytes <= INT64_MAX && offset <= INT64_MAX - bytes);
+    assert(offset >= 0 && bytes >= 0 &&
+           bytes <= INT64_MAX && offset <= INT64_MAX - bytes);

'bytes <= INT64_MAX' was previously a real runtime check, but is now a tautology and therefore a dead branch; a picky compiler might complain. This assert could be compressed to:

assert(offset >= 0 && (uint64_t) bytes <= INT64_MAX - offset);

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

Reply via email to