Messages in this thread | | | Subject | Re: [PATCH v2 block/for-linus] writeback: sync_inodes_sb() must write out I_DIRTY_TIME inodes and always call wait_sb_inodes() | From | Jens Axboe <> | Date | Tue, 25 Aug 2015 14:37:17 -0600 |
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On 08/25/2015 12:11 PM, Tejun Heo wrote: > 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 > are in-flight. > > 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 > WB_SYNC_ALL writebacks. > > Kudos to Eryu, Dave and Jan for tracking down the issue. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Fixes: e79729123f63 ("writeback: don't issue wb_writeback_work if clean") > Link: http://lkml.kernel.org/g/20150812101204.GE17933@dhcp-13-216.nay.redhat.com > Reported-and-bisected-by: Eryu Guan <eguan@redhat.com> > Cc: Dave Chinner <david@fromorbit.com> > Cc: Jan Kara <jack@suse.com> > Cc: Ted Ts'o <tytso@google.com>
Added for 4.2.
-- Jens Axboe
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