nbd/server: Favor [u]int64_t over off_t

Although our compile-time environment is set up so that we always
support long files with 64-bit off_t, we have no guarantee whether
off_t is the same type as int64_t.  This requires casts when
printing values, and prevents us from directly using qemu_strtoi64()
(which will be done in the next patch). Let's just flip to uint64_t
where possible, and stick to int64_t for detecting failure of
blk_getlength(); we also keep the assertions added in the previous
patch that the resulting values fit in 63 bits.  The overflow check
in nbd_co_receive_request() was already sane (request->from is
validated to fit in 63 bits, and request->len is 32 bits, so the
addition can't overflow 64 bits), but rewrite it in a form easier
to recognize as a typical overflow check.

Rename the variable 'description' to keep line lengths reasonable.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190117193658.16413-7-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/block/nbd.h b/include/block/nbd.h
index 1971b55789..24be9570bb 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -294,8 +294,8 @@ int nbd_errno_to_system_errno(int err);
 typedef struct NBDExport NBDExport;
 typedef struct NBDClient NBDClient;
 
-NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
-                          const char *name, const char *description,
+NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset,
+                          uint64_t size, const char *name, const char *desc,
                           const char *bitmap, uint16_t nbdflags,
                           void (*close)(NBDExport *), bool writethrough,
                           BlockBackend *on_eject_blk, Error **errp);