diff options
author | Tejun Heo <tj@kernel.org> | 2015-08-25 14:11:52 -0400 |
---|---|---|
committer | Alex Shi <alex.shi@linaro.org> | 2016-06-08 11:09:35 +0800 |
commit | cb336a021980e84bdb5da9217c8145eb51cc65da (patch) | |
tree | e0b0b7347c21800df211338516374fe12d825a6e | |
parent | 27b58b862a7d96f98106c9ee7a1bbb449d3634d6 (diff) |
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
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>
Signed-off-by: Jens Axboe <axboe@fb.com>
(cherry picked from commit 006a0973ed020a81fe1f24b511ce9feb53f70e44)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
get the merge conflict solution from upstream b0a1ea51bda
for fs/fs-writeback.c
-rw-r--r-- | fs/fs-writeback.c | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 1b85e7eacca6..2506745a2967 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -783,9 +783,6 @@ static void bdi_split_work_to_wbs(struct backing_dev_info *bdi, struct wb_iter iter; might_sleep(); - - if (!bdi_has_dirty_io(bdi)) - return; restart: rcu_read_lock(); bdi_for_each_wb(wb, bdi, &iter, next_memcg_id) { @@ -794,8 +791,12 @@ restart: struct wb_writeback_work *work; long nr_pages; - if (!wb_has_dirty_io(wb) || - (skip_if_busy && writeback_in_progress(wb))) + /* SYNC_ALL writes out I_DIRTY_TIME too */ + if (!wb_has_dirty_io(wb) && + (base_work->sync_mode == WB_SYNC_NONE || + list_empty(&wb->b_dirty_time))) + continue; + if (skip_if_busy && writeback_in_progress(wb)) continue; nr_pages = wb_split_bdi_pages(wb, base_work->nr_pages); @@ -860,8 +861,7 @@ static void bdi_split_work_to_wbs(struct backing_dev_info *bdi, { might_sleep(); - if (bdi_has_dirty_io(bdi) && - (!skip_if_busy || !writeback_in_progress(&bdi->wb))) { + if (!skip_if_busy || !writeback_in_progress(&bdi->wb)) { base_work->auto_free = 0; wb_queue_work(&bdi->wb, base_work); } @@ -2246,8 +2246,12 @@ void sync_inodes_sb(struct super_block *sb) }; struct backing_dev_info *bdi = sb->s_bdi; - /* Nothing to do? */ - if (!bdi_has_dirty_io(bdi) || bdi == &noop_backing_dev_info) + /* + * Can't skip on !bdi_has_dirty() because we should wait for !dirty + * inodes under writeback and I_DIRTY_TIME inodes ignored by + * bdi_has_dirty() need to be written out too. + */ + if (bdi == &noop_backing_dev_info) return; WARN_ON(!rwsem_is_locked(&sb->s_umount)); |