bcache: improve bcache_reboot() (eb8cbb6d) · Commits · 戴 / test

This patch tries to release mutex bch_register_lock early, to give chance to stop cache set and bcache device early. This patch also expends time out of stopping all bcache device from 2 seconds to 10 seconds, because stopping writeback rate update worker may delay for 5 seconds, 2 seconds is not enough. After this patch applied, stopping bcache devices during system reboot or shutdown is very hard to be observed any more. Signed-off-by:

Coly Li <colyli@suse.de> Reviewed-by:

Hannes Reinecke <hare@suse.com> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/super.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -2397,10 +2397,19 @@ static int bcache_reboot(struct notifier_block n, unsigned long code, void x)
		list_for_each_entry_safe(dc, tdc, &uncached_devices, list)
		bcache_device_stop(&dc->disk);

		mutex_unlock(&bch_register_lock);

		/*
		* Give an early chance for other kthreads and
		* kworkers to stop themselves
		*/
		schedule();

		/* What's a condition variable? */
		while (1) {
		long timeout = start + 2 * HZ - jiffies;
		long timeout = start + 10 * HZ - jiffies;

		mutex_lock(&bch_register_lock);
		stopped = list_empty(&bch_cache_sets) &&
		list_empty(&uncached_devices);

		@@ -2412,7 +2421,6 @@ static int bcache_reboot(struct notifier_block n, unsigned long code, void x)

		mutex_unlock(&bch_register_lock);
		schedule_timeout(timeout);
		mutex_lock(&bch_register_lock);
		}

		finish_wait(&unregister_wait, &wait);

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