Commit 12a6caf2 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

md: only delete entries from all_mddevs when the disk is freed 



This ensures device names don't get prematurely reused.  Instead add a
deleted flag to skip already deleted devices in mddev_get and other
places that only want to see live mddevs.

Reported-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarSong Liu <song@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 16648bac

drivers/md/md.c

+38 −18
Original line number Diff line number Diff line
@@ -625,6 +625,10 @@ EXPORT_SYMBOL(md_flush_request); 


static inline struct mddev *mddev_get(struct mddev *mddev)

{

	lockdep_assert_held(&all_mddevs_lock);



	if (test_bit(MD_DELETED, &mddev->flags))

		return NULL;

	atomic_inc(&mddev->active);

	return mddev;

}
@@ -639,7 +643,7 @@ static void mddev_put(struct mddev *mddev) 
	    mddev->ctime == 0 && !mddev->hold_active) {

		/* Array is not configured at all, and not held active,

		 * so destroy it */

		list_del_init(&mddev->all_mddevs);

		set_bit(MD_DELETED, &mddev->flags);



		/*

		 * Call queue_work inside the spinlock so that
@@ -719,8 +723,8 @@ static struct mddev *mddev_find(dev_t unit) 


	spin_lock(&all_mddevs_lock);

	mddev = mddev_find_locked(unit);

	if (mddev)

		mddev_get(mddev);

	if (mddev && !mddev_get(mddev))

		mddev = NULL;

	spin_unlock(&all_mddevs_lock);



	return mddev;
@@ -3338,6 +3342,8 @@ static bool md_rdev_overlaps(struct md_rdev *rdev) 


	spin_lock(&all_mddevs_lock);

	list_for_each_entry(mddev, &all_mddevs, all_mddevs) {

		if (test_bit(MD_DELETED, &mddev->flags))

			continue;

		rdev_for_each(rdev2, mddev) {

			if (rdev != rdev2 && rdev->bdev == rdev2->bdev &&

			    md_rdevs_overlap(rdev, rdev2)) {
@@ -5525,11 +5531,10 @@ md_attr_show(struct kobject *kobj, struct attribute *attr, char *page) 
	if (!entry->show)

		return -EIO;

	spin_lock(&all_mddevs_lock);

	if (list_empty(&mddev->all_mddevs)) {

	if (!mddev_get(mddev)) {

		spin_unlock(&all_mddevs_lock);

		return -EBUSY;

	}

	mddev_get(mddev);

	spin_unlock(&all_mddevs_lock);



	rv = entry->show(mddev, page);
@@ -5550,11 +5555,10 @@ md_attr_store(struct kobject *kobj, struct attribute *attr, 
	if (!capable(CAP_SYS_ADMIN))

		return -EACCES;

	spin_lock(&all_mddevs_lock);

	if (list_empty(&mddev->all_mddevs)) {

	if (!mddev_get(mddev)) {

		spin_unlock(&all_mddevs_lock);

		return -EBUSY;

	}

	mddev_get(mddev);

	spin_unlock(&all_mddevs_lock);

	rv = entry->store(mddev, page, length);

	mddev_put(mddev);
@@ -7849,7 +7853,7 @@ static void md_free_disk(struct gendisk *disk) 
	bioset_exit(&mddev->bio_set);

	bioset_exit(&mddev->sync_set);



	kfree(mddev);

	mddev_free(mddev);

}



const struct block_device_operations md_fops =
@@ -8171,6 +8175,8 @@ static void *md_seq_start(struct seq_file *seq, loff_t *pos) 
		if (!l--) {

			mddev = list_entry(tmp, struct mddev, all_mddevs);

			mddev_get(mddev);

			if (!mddev_get(mddev))

				continue;

			spin_unlock(&all_mddevs_lock);

			return mddev;

		}
@@ -8184,25 +8190,35 @@ static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos) 
{

	struct list_head *tmp;

	struct mddev *next_mddev, *mddev = v;

	struct mddev *to_put = NULL;



	++*pos;

	if (v == (void*)2)

		return NULL;



	spin_lock(&all_mddevs_lock);

	if (v == (void*)1)

	if (v == (void*)1) {

		tmp = all_mddevs.next;

	else

	} else {

		to_put = mddev;

		tmp = mddev->all_mddevs.next;

	if (tmp != &all_mddevs)

		next_mddev = mddev_get(list_entry(tmp,struct mddev,all_mddevs));

	else {

	}



	for (;;) {

		if (tmp == &all_mddevs) {

			next_mddev = (void*)2;

			*pos = 0x10000;

			break;

		}

		next_mddev = list_entry(tmp, struct mddev, all_mddevs);

		if (mddev_get(next_mddev))

			break;

		mddev = next_mddev;

		tmp = mddev->all_mddevs.next;

	};

	spin_unlock(&all_mddevs_lock);



	if (v != (void*)1)

	if (to_put)

		mddev_put(mddev);

	return next_mddev;
@@ -8766,6 +8782,8 @@ void md_do_sync(struct md_thread *thread) 
			goto skip;

		spin_lock(&all_mddevs_lock);

		list_for_each_entry(mddev2, &all_mddevs, all_mddevs) {

			if (test_bit(MD_DELETED, &mddev2->flags))

				continue;

			if (mddev2 == mddev)

				continue;

			if (!mddev->parallel_resync
@@ -9568,7 +9586,8 @@ static int md_notify_reboot(struct notifier_block *this, 


	spin_lock(&all_mddevs_lock);

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

		mddev_get(mddev);

		if (!mddev_get(mddev))

			continue;

		spin_unlock(&all_mddevs_lock);

		if (mddev_trylock(mddev)) {

			if (mddev->pers)
@@ -9923,7 +9942,8 @@ static __exit void md_exit(void) 


	spin_lock(&all_mddevs_lock);

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

		mddev_get(mddev);

		if (!mddev_get(mddev))

			continue;

		spin_unlock(&all_mddevs_lock);

		export_array(mddev);

		mddev->ctime = 0;

drivers/md/md.h

+2 −0
Original line number Diff line number Diff line
@@ -254,6 +254,7 @@ struct md_cluster_info; 
 * @MD_NOT_READY: do_md_run() is active, so 'array_state', ust not report that

 *		   array is ready yet.

 * @MD_BROKEN: This is used to stop writes and mark array as failed.

 * @MD_DELETED: This device is being deleted

 *

 * change UNSUPPORTED_MDDEV_FLAGS for each array type if new flag is added

 */
@@ -270,6 +271,7 @@ enum mddev_flags { 
	MD_UPDATING_SB,

	MD_NOT_READY,

	MD_BROKEN,

	MD_DELETED,

};



enum mddev_sb_flags {