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author | Tejun Heo <tj@kernel.org> | 2015-08-25 20:11:52 +0200 |
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committer | Jens Axboe <axboe@fb.com> | 2015-08-25 22:35:09 +0200 |
commit | 006a0973ed020a81fe1f24b511ce9feb53f70e44 (patch) | |
tree | 6a5ab2d9913302a2bcd5c725ed91682050c289d2 /fs/fs-writeback.c | |
parent | Linux 4.2-rc8 (diff) | |
download | linux-006a0973ed020a81fe1f24b511ce9feb53f70e44.tar.xz linux-006a0973ed020a81fe1f24b511ce9feb53f70e44.zip |
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>
Diffstat (limited to '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 518c6294bf6c..5fa588e933d5 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -844,14 +844,15 @@ 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_blkcg_id) { - 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; base_work->nr_pages = wb_split_bdi_pages(wb, nr_pages); @@ -899,8 +900,7 @@ 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; base_work->single_wait = 0; base_work->single_done = 0; @@ -2275,8 +2275,12 @@ 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)); |