tree c09d5578604e83c2c421aca32b6b125d70b4a2bc
parent 2f800fbd777b792de54187088df19a7df0251254
author Wu Fengguang <fengguang.wu@intel.com> 1312838387 -0600
committer Wu Fengguang <fengguang.wu@intel.com> 1324189225 +0800

btrfs: fix dirtied pages accounting on sub-page writes

When doing 1KB sequential writes to the same page,
balance_dirty_pages_ratelimited_nr() should be called once instead of 4
times, the latter makes the dirtier tasks be throttled much too heavy.

Fix it with proper de-accounting on clear_page_dirty_for_io().

CC: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>