diff options
| author | Tejun Heo <tj@kernel.org> | 2014-09-08 08:03:59 +0900 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2016-09-13 13:35:20 +0200 |
| commit | b5635345b4714afb914522e15c26bc66055c14ee (patch) | |
| tree | 4b620fdc15b5f18a2e6e920c85c6cd5e0757a634 | |
| parent | 6af0cab8fa04cfe9fb99f244171116f9a7a18e4d (diff) | |
bdi: make backing_dev_info->wb.dwork canceling stricter
Canceling of bdi->wb.dwork is currently a bit mushy.
bdi_wb_shutdown() performs cancel_delayed_work_sync() at the end after
shutting down and flushing the delayed_work and bdi_destroy() tries
yet again after bdi_unregister().
bdi->wb.dwork is queued only after checking BDI_registered while
holding bdi->wb_lock and bdi_wb_shutdown() clears the flag while
holding the same lock and then flushes the delayed_work. There's no
way the delayed_work can be queued again after that.
Replace the two unnecessary cancel_delayed_work_sync() invocations
with WARNs on pending. This simplifies and clarifies the code a bit
and will help future changes in further isolating bdi_writeback
handling.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
| -rw-r--r-- | mm/backing-dev.c | 15 |
1 files changed, 2 insertions, 13 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 2a05c2642..7822c9db9 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -375,13 +375,7 @@ static void bdi_wb_shutdown(struct backing_dev_info *bdi) mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0); flush_delayed_work(&bdi->wb.dwork); WARN_ON(!list_empty(&bdi->work_list)); - - /* - * This shouldn't be necessary unless @bdi for some reason has - * unflushed dirty IO after work_list is drained. Do it anyway - * just in case. - */ - cancel_delayed_work_sync(&bdi->wb.dwork); + WARN_ON(delayed_work_pending(&bdi->wb.dwork)); } /* @@ -496,12 +490,7 @@ void bdi_destroy(struct backing_dev_info *bdi) bdi_unregister(bdi); - /* - * If bdi_unregister() had already been called earlier, the dwork - * could still be pending because bdi_prune_sb() can race with the - * bdi_wakeup_thread_delayed() calls from __mark_inode_dirty(). - */ - cancel_delayed_work_sync(&bdi->wb.dwork); + WARN_ON(delayed_work_pending(&bdi->wb.dwork)); for (i = 0; i < NR_BDI_STAT_ITEMS; i++) percpu_counter_destroy(&bdi->bdi_stat[i]); |