This fixes several bugs and one missing feature:
- cluster_read() was needlessly used for reading files of size exactly 1
block.
- EFAULT errors for read didn't terminate the loop. This was probably
harmless.
- IO_VMIO handling was missing near line 275. I don't know what this does.
- B_CLUSTEROK was only set if (doclusterwrite) nead line 293. This was
harmless, if only because another bug prevents doclusterwrite from being
0.
- MNT_NOATIME wasn't implemented.
This should be in 2.2, of course.
Reviewed by: davidg