Unverified Commit 844655fd authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!5521 md/raid5: fix atomicity violation in raid5_cache_count 

Merge Pull Request from: @ci-robot 
 
PR sync from: Li Nan <linan122@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/GLRLYZW5GMSUW6S4C7HKEETUADWG2TAX/ 
 
https://gitee.com/src-openeuler/kernel/issues/I8YV0T 
 
Link:https://gitee.com/openeuler/kernel/pulls/5521

 

Reviewed-by: default avatarYu Kuai <yukuai3@huawei.com>
Reviewed-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents c3a5ce23 1e76628c

drivers/md/raid5.c

+8 −6
Original line number Diff line number Diff line
@@ -2350,7 +2350,7 @@ static int grow_one_stripe(struct r5conf *conf, gfp_t gfp) 
	atomic_inc(&conf->active_stripes);



	raid5_release_stripe(sh);

	conf->max_nr_stripes++;

	WRITE_ONCE(conf->max_nr_stripes, conf->max_nr_stripes + 1);

	return 1;

}
@@ -2647,7 +2647,7 @@ static int drop_one_stripe(struct r5conf *conf) 
	shrink_buffers(sh);

	free_stripe(conf->slab_cache, sh);

	atomic_dec(&conf->active_stripes);

	conf->max_nr_stripes--;

	WRITE_ONCE(conf->max_nr_stripes, conf->max_nr_stripes - 1);

	return 1;

}
@@ -6570,7 +6570,7 @@ raid5_set_cache_size(struct mddev *mddev, int size) 
	if (size <= 16 || size > 32768)

		return -EINVAL;



	conf->min_nr_stripes = size;

	WRITE_ONCE(conf->min_nr_stripes, size);

	mutex_lock(&conf->cache_size_mutex);

	while (size < conf->max_nr_stripes &&

	       drop_one_stripe(conf))
@@ -6582,7 +6582,7 @@ raid5_set_cache_size(struct mddev *mddev, int size) 
	mutex_lock(&conf->cache_size_mutex);

	while (size > conf->max_nr_stripes)

		if (!grow_one_stripe(conf, GFP_KERNEL)) {

			conf->min_nr_stripes = conf->max_nr_stripes;

			WRITE_ONCE(conf->min_nr_stripes, conf->max_nr_stripes);

			result = -ENOMEM;

			break;

		}
@@ -7146,11 +7146,13 @@ static unsigned long raid5_cache_count(struct shrinker *shrink, 
				       struct shrink_control *sc)

{

	struct r5conf *conf = container_of(shrink, struct r5conf, shrinker);

	int max_stripes = READ_ONCE(conf->max_nr_stripes);

	int min_stripes = READ_ONCE(conf->min_nr_stripes);



	if (conf->max_nr_stripes < conf->min_nr_stripes)

	if (max_stripes < min_stripes)

		/* unlikely, but not impossible */

		return 0;

	return conf->max_nr_stripes - conf->min_nr_stripes;

	return max_stripes - min_stripes;

}



static struct r5conf *setup_conf(struct mddev *mddev)