writeback: sync_inodes_sb() must write out I_DIRTY_TIME inodes and always call wait_sb_inodes()
e79729123f63 ("writeback: don't issue wb_writeback_work if clean")
updated writeback path to avoid kicking writeback work items if there
are no inodes to be written out; unfortunately, the avoidance logic
was too aggressive and broke sync_inodes_sb().
* sync_inodes_sb() must write out I_DIRTY_TIME inodes but I_DIRTY_TIME
inodes dont't contribute to bdi/wb_has_dirty_io() tests and were
being skipped over.
* inodes are taken off wb->b_dirty/io/more_io lists after writeback
starts on them. sync_inodes_sb() skipping wait_sb_inodes() when
bdi_has_dirty_io() breaks it by making it return while writebacks
This patch fixes the breakages by
* Removing bdi_has_dirty_io() shortcut from bdi_split_work_to_wbs().
The callers are already testing the condition.
* Removing bdi_has_dirty_io() shortcut from sync_inodes_sb() so that
it always calls into bdi_split_work_to_wbs() and wait_sb_inodes().
* Making bdi_split_work_to_wbs() consider the b_dirty_time list for
Kudos to Eryu, Dave and Jan for tracking down the issue.
Signed-off-by: Tejun Heo <firstname.lastname@example.org>
Fixes: e79729123f63 ("writeback: don't issue wb_writeback_work if clean")
Reported-and-bisected-by: Eryu Guan <email@example.com>
Cc: Dave Chinner <firstname.lastname@example.org>
Cc: Jan Kara <email@example.com>
Cc: Ted Ts'o <firstname.lastname@example.org>
Signed-off-by: Jens Axboe <email@example.com>
1 file changed