Move the backing_object chain traversal into its own function.

[jeff]

Summary

This should be functionally identical. In a later diff I collapse the two calls to vm_object_next() into one.

[jeff]

sys/vm/vm_fault.c

964

In retrospect it might end up making the locking more clear if I split the zero fill off. I would like to do that in a subsequent patch.

[dougm]

sys/vm/vm_fault.c

1193

I perceive that the point of the next label before this change and the new function introduced in its stead is all to avoid wrapping lines 1267-1379 in a giant if (fs.object->type != OBJT_DEFAULT) {} block, with associated indentation, and all the line wrapping that would lead to. It seems that a function to wrap all that code would solve the same problem in a more direct way.

[jeff]

sys/vm/vm_fault.c

1193

Yes definitely. a couple of diffs after this resolve this more cleanly. I just didn't want to post it all at once for fear of burning people out. I wanted to move the large blocks out whole before too much restructuring.

[dougm]

It seems harmless.