Commit defad61a authored by NeilBrown's avatar NeilBrown
Browse files

md: md_stop_writes requires mddev_lock. 



As md_stop_writes manipulates the sync_thread and calls md_update_sb,
it need to be called with mddev_lock held.

In all internal cases it is, but the symbol is exported for dm-raid to
call and in that case the lock won't be help.
Do make an exported version which takes the lock, and an internal
version which does not.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 43c73ca4

drivers/md/md.c

+10 −3
Original line number Diff line number Diff line
@@ -4704,7 +4704,7 @@ static void md_clean(mddev_t *mddev) 
	mddev->plug = NULL;

}



void md_stop_writes(mddev_t *mddev)

static void __md_stop_writes(mddev_t *mddev)

{

	if (mddev->sync_thread) {

		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
@@ -4724,6 +4724,13 @@ void md_stop_writes(mddev_t *mddev) 
		md_update_sb(mddev, 1);

	}

}



void md_stop_writes(mddev_t *mddev)

{

	mddev_lock(mddev);

	__md_stop_writes(mddev);

	mddev_unlock(mddev);

}

EXPORT_SYMBOL_GPL(md_stop_writes);



void md_stop(mddev_t *mddev)
@@ -4748,7 +4755,7 @@ static int md_set_readonly(mddev_t *mddev, int is_open) 
		goto out;

	}

	if (mddev->pers) {

		md_stop_writes(mddev);

		__md_stop_writes(mddev);



		err  = -ENXIO;

		if (mddev->ro==1)
@@ -4785,7 +4792,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open) 
		if (mddev->ro)

			set_disk_ro(disk, 0);



		md_stop_writes(mddev);

		__md_stop_writes(mddev);

		md_stop(mddev);

		mddev->queue->merge_bvec_fn = NULL;

		mddev->queue->unplug_fn = NULL;

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