block-backend: blk_check_byte_request(): int64_t bytes

Rename size and make it int64_t to correspond to modern block layer,
which always uses int64_t for offset and bytes (not in blk layer yet,
which is a task for following commits).

All callers pass int or unsigned int.

So, for bytes in [0, INT_MAX] nothing is changed, for negative bytes we
now fail on "bytes < 0" check instead of "bytes > INT_MAX" check.

Note, that blk_check_byte_request() still doesn't allow requests
exceeding INT_MAX.

Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Signed-off-by: Eric Blake <[email protected]>

block/block-backend.c

@@ -1161,11 +1161,11 @@ void blk_set_disable_request_queuing(BlockBackend *blk, bool disable)
 }
 
 static int blk_check_byte_request(BlockBackend *blk, int64_t offset,
-                                  size_t size)
+                                  int64_t bytes)
 {
     int64_t len;
 
-    if (size > INT_MAX) {
+    if (bytes < 0 || bytes > INT_MAX) {
         return -EIO;
     }
 
@@ -1183,7 +1183,7 @@ static int blk_check_byte_request(BlockBackend *blk, int64_t offset,
             return len;
         }
 
-        if (offset > len || len - offset < size) {
+        if (offset > len || len - offset < bytes) {
             return -EIO;
         }
     }