Commit 16648bac authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

md: stop using for_each_mddev in md_exit 



Just do a simple list_for_each_entry_safe on all_mddevs, and only grab a
reference when we drop the lock and delete the now unused for_each_mddev
macro.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarSong Liu <song@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f2651434

drivers/md/md.c

+11 −28
Original line number Diff line number Diff line
@@ -368,28 +368,6 @@ EXPORT_SYMBOL_GPL(md_new_event); 
static LIST_HEAD(all_mddevs);

static DEFINE_SPINLOCK(all_mddevs_lock);



/*

 * iterates through all used mddevs in the system.

 * We take care to grab the all_mddevs_lock whenever navigating

 * the list, and to always hold a refcount when unlocked.

 * Any code which breaks out of this loop while own

 * a reference to the current mddev and must mddev_put it.

 */

#define for_each_mddev(_mddev,_tmp)					\

									\

	for (({ spin_lock(&all_mddevs_lock);				\

		_tmp = all_mddevs.next;					\

		_mddev = NULL;});					\

	     ({ if (_tmp != &all_mddevs)				\

			mddev_get(list_entry(_tmp, struct mddev, all_mddevs));\

		spin_unlock(&all_mddevs_lock);				\

		if (_mddev) mddev_put(_mddev);				\

		_mddev = list_entry(_tmp, struct mddev, all_mddevs);	\

		_tmp != &all_mddevs;});					\

	     ({ spin_lock(&all_mddevs_lock);				\

		_tmp = _tmp->next;})					\

		)



/* Rather than calling directly into the personality make_request function,

 * IO requests come here first so that we can check if the device is

 * being suspended pending a reconfiguration.
@@ -9923,8 +9901,7 @@ void md_autostart_arrays(int part) 


static __exit void md_exit(void)

{

	struct mddev *mddev;

	struct list_head *tmp;

	struct mddev *mddev, *n;

	int delay = 1;



	unregister_blkdev(MD_MAJOR,"md");
@@ -9944,17 +9921,23 @@ static __exit void md_exit(void) 
	}

	remove_proc_entry("mdstat", NULL);



	for_each_mddev(mddev, tmp) {

	spin_lock(&all_mddevs_lock);

	list_for_each_entry_safe(mddev, n, &all_mddevs, all_mddevs) {

		mddev_get(mddev);

		spin_unlock(&all_mddevs_lock);

		export_array(mddev);

		mddev->ctime = 0;

		mddev->hold_active = 0;

		/*

		 * for_each_mddev() will call mddev_put() at the end of each

		 * iteration.  As the mddev is now fully clear, this will

		 * schedule the mddev for destruction by a workqueue, and the

		 * As the mddev is now fully clear, mddev_put will schedule

		 * the mddev for destruction by a workqueue, and the

		 * destroy_workqueue() below will wait for that to complete.

		 */

		mddev_put(mddev);

		spin_lock(&all_mddevs_lock);

	}

	spin_unlock(&all_mddevs_lock);



	destroy_workqueue(md_rdev_misc_wq);

	destroy_workqueue(md_misc_wq);

	destroy_workqueue(md_wq);