| Message ID | 20170221170958.21845-9-jack@suse.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello, On Tue, Feb 21, 2017 at 06:09:53PM +0100, Jan Kara wrote: > Currently we waited for all cgwbs to get freed in cgwb_bdi_destroy() > which also means that writeback has been shutdown on them. Since this > wait is going away, directly shutdown writeback on cgwbs from > cgwb_bdi_destroy() to avoid live writeback structures after > bdi_unregister() has finished. Hmmm... the only thing which is a bit bothering is that after removing the shutdown from release_workfn this would make the final flushing sequential, one cgwb at a time, which in certain cases can take an unnecessarily long time. It's not a correctness issue tho and if it becomes a problem we can deal with it by splitting wb_shutdown() into two pieces - the unregistration / issuing of the work items, and the flushing of those. Other than that, looks good to me. Acked-by: Tejun Heo <tj@kernel.org> Thanks.
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 54b9e934eef4..c9623b410170 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -700,6 +700,7 @@ static void cgwb_bdi_destroy(struct backing_dev_info *bdi) struct radix_tree_iter iter; struct rb_node *rbn; void **slot; + struct wb_writeback *wb; WARN_ON(test_bit(WB_registered, &bdi->wb.state)); @@ -716,6 +717,14 @@ static void cgwb_bdi_destroy(struct backing_dev_info *bdi) congested->__bdi = NULL; /* mark @congested unlinked */ } + while (!list_empty(&bdi->wb_list)) { + wb = list_first_entry(&bdi->wb_list, struct bdi_writeback, + bdi_node); + spin_unlock_irq(&cgwb_lock); + wb_shutdown(wb); + spin_lock_irq(&cgwb_lock); + } + spin_unlock_irq(&cgwb_lock); /*
Currently we waited for all cgwbs to get freed in cgwb_bdi_destroy() which also means that writeback has been shutdown on them. Since this wait is going away, directly shutdown writeback on cgwbs from cgwb_bdi_destroy() to avoid live writeback structures after bdi_unregister() has finished. Signed-off-by: Jan Kara <jack@suse.cz> --- mm/backing-dev.c | 9 +++++++++ 1 file changed, 9 insertions(+)