md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk (f4be6b43) · Commits · 戴 / test

We will shortly allow md devices with no gendisk (they are attached to a dm-target instead). That will cause mdname() to return 'mdX'. There is one place where mdname really needs to be unique: when creating the name for a slab cache. So in that case, if there is no gendisk, you the address of the mddev formatted in HEX to provide a unique name. Signed-off-by:

NeilBrown <neilb@suse.de>

drivers/md/raid5.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -1337,10 +1337,14 @@ static int grow_stripes(raid5_conf_t *conf, int num)
		struct kmem_cache *sc;
		int devs = max(conf->raid_disks, conf->previous_raid_disks);

		if (conf->mddev->gendisk)
		sprintf(conf->cache_name[0],
		"raid%d-%s", conf->level, mdname(conf->mddev));
		sprintf(conf->cache_name[1],
		"raid%d-%s-alt", conf->level, mdname(conf->mddev));
		else
		sprintf(conf->cache_name[0],
		"raid%d-%p", conf->level, conf->mddev);
		sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);

		conf->active_name = 0;
		sc = kmem_cache_create(conf->cache_name[conf->active_name],
		sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),

drivers/md/raid5.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -388,7 +388,7 @@ struct raid5_private_data {
		* two caches.
		*/
		int active_name;
		char cache_name[2][20];
		char cache_name[2][32];
		struct kmem_cache slab_cache; / for allocating stripes */

		int seq_flush, seq_write;

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