4b14cc0205
fixes was applicable to HEAD, originally it was thought this should only be done in RELENG_4. Implement IO_INVAL in the vnode op for writing by marking the buffer as "no cache". This fix has already been applied to RELENG_4 as Rev. 1.65.2.15 of ufs/ufs/ufs_readwrite.c. Reviewed by: alc, tegge