Commit 76487f02 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

z2ram: use separate gendisk for the different modes 



Use separate gendisks (which share a tag_set) for the different operating
modes instead of redirecting the gendisk lookup using a probe callback.
This avoids potential problems with aliased block_device instances and
will eventually allow for removing the blk_register_region framework.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 6c3a05e1

drivers/block/z2ram.c

+58 −42
Original line number Diff line number Diff line
@@ -63,7 +63,7 @@ static int current_device = -1; 


static DEFINE_SPINLOCK(z2ram_lock);



static struct gendisk *z2ram_gendisk;

static struct gendisk *z2ram_gendisk[Z2MINOR_COUNT];



static blk_status_t z2_queue_rq(struct blk_mq_hw_ctx *hctx,

				const struct blk_mq_queue_data *bd)
@@ -283,7 +283,7 @@ static int z2_open(struct block_device *bdev, fmode_t mode) 


		current_device = device;

		z2ram_size <<= Z2RAM_CHUNKSHIFT;

		set_capacity(z2ram_gendisk, z2ram_size >> 9);

		set_capacity(z2ram_gendisk[device], z2ram_size >> 9);

	}



	mutex_unlock(&z2ram_mutex);
@@ -315,71 +315,87 @@ static const struct block_device_operations z2_fops = { 
	.release = z2_release,

};



static struct kobject *z2_find(dev_t dev, int *part, void *data)

{

	*part = 0;

	return get_disk_and_module(z2ram_gendisk);

}



static struct request_queue *z2_queue;

static struct blk_mq_tag_set tag_set;



static const struct blk_mq_ops z2_mq_ops = {

	.queue_rq = z2_queue_rq,

};



static int z2ram_register_disk(int minor)

{

	struct request_queue *q;

	struct gendisk *disk;



	disk = alloc_disk(1);

	if (!disk)

		return -ENOMEM;



	q = blk_mq_init_queue(&tag_set);

	if (IS_ERR(q)) {

		put_disk(disk);

		return PTR_ERR(q);

	}



	disk->major = Z2RAM_MAJOR;

	disk->first_minor = minor;

	disk->fops = &z2_fops;

	if (minor)

		sprintf(disk->disk_name, "z2ram%d", minor);

	else

		sprintf(disk->disk_name, "z2ram");

	disk->queue = q;



	z2ram_gendisk[minor] = disk;

	add_disk(disk);

	return 0;

}



static int __init z2_init(void)

{

	int ret;

	int ret, i;



	if (!MACH_IS_AMIGA)

		return -ENODEV;



	ret = -EBUSY;

	if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))

		goto err;

		return -EBUSY;



	ret = -ENOMEM;

	z2ram_gendisk = alloc_disk(1);

	if (!z2ram_gendisk)

		goto out_disk;

	tag_set.ops = &z2_mq_ops;

	tag_set.nr_hw_queues = 1;

	tag_set.nr_maps = 1;

	tag_set.queue_depth = 16;

	tag_set.numa_node = NUMA_NO_NODE;

	tag_set.flags = BLK_MQ_F_SHOULD_MERGE;

	ret = blk_mq_alloc_tag_set(&tag_set);

	if (ret)

		goto out_unregister_blkdev;



	z2_queue = blk_mq_init_sq_queue(&tag_set, &z2_mq_ops, 16,

					BLK_MQ_F_SHOULD_MERGE);

	if (IS_ERR(z2_queue)) {

		ret = PTR_ERR(z2_queue);

		z2_queue = NULL;

		goto out_queue;

	for (i = 0; i < Z2MINOR_COUNT; i++) {

		ret = z2ram_register_disk(i);

		if (ret && i == 0)

			goto out_free_tagset;

	}



	z2ram_gendisk->major = Z2RAM_MAJOR;

	z2ram_gendisk->first_minor = 0;

	z2ram_gendisk->fops = &z2_fops;

	sprintf(z2ram_gendisk->disk_name, "z2ram");



	z2ram_gendisk->queue = z2_queue;

	add_disk(z2ram_gendisk);

	blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,

			    z2_find, NULL, NULL);



	return 0;



out_queue:

	put_disk(z2ram_gendisk);

out_disk:

out_free_tagset:

	blk_mq_free_tag_set(&tag_set);

out_unregister_blkdev:

	unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);

err:

	return ret;

}



static void __exit z2_exit(void)

{

	int i, j;

	blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT);



	unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);

	del_gendisk(z2ram_gendisk);

	put_disk(z2ram_gendisk);

	blk_cleanup_queue(z2_queue);



	for (i = 0; i < Z2MINOR_COUNT; i++) {

		del_gendisk(z2ram_gendisk[i]);

		blk_cleanup_queue(z2ram_gendisk[i]->queue);

		put_disk(z2ram_gendisk[i]);

	}

	blk_mq_free_tag_set(&tag_set);



	if (current_device != -1) {