K 10
svn:author
V 3
kib
K 8
svn:date
V 27
2010-06-08T17:54:28.087722Z
K 7
svn:log
V 737
Reorganize the code in bdwrite() which handles move of dirtiness
from the buffer pages to buffer. Combine the code to set buffer
dirty range (previously in vfs_setdirty()) and to clean the pages
(vfs_clean_pages()) into new function vfs_clean_pages_dirty_buf(). Now
the vm object lock is acquired only once.

Drain the VPO_BUSY bit of the buffer pages before setting valid
and clean bits in vfs_clean_pages_dirty_buf() with new helper
vfs_drain_busy_pages(). pmap_clear_modify() asserts that page is not
busy.

In vfs_busy_pages(), move the wait for draining of VPO_BUSY before
the dirtyness handling, to follow the structure of
vfs_clean_pages_dirty_buf().

Reported and tested by:	pho
Suggested and reviewed by:	alc
MFC after:	2 weeks

END