Move the fault getpages code into its own function.

[jeff]

Summary

I left the readahead in the main loop because we don't need to repeat the dropbehind. However, storing the cached entry variables before unlocking the map was only done once before. I don't think this was important to the algorithm nor is it especially expensive.

[jeff]

Fix a merge issue.

[kib]

sys/vm/vm_fault.c

1088

Please do not do this. You are mixing VM_PAGER_XXX (pager errors namespace) and KERN_XXX (Mach errors).

This is arguably incorrect in particular because the numeric values intersect. Translate the rest of errors into KERN_ as well.

[jeff]

sys/vm/vm_fault.c

1088

ah yes. Will do.

I would argue that we should convert the whole mess to errno but not today.

[jeff]

Correct return values. Don't send pager errors back to vm_fault().