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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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2020-10-29 15:58:40 +01:00 committed by Jens Axboe
parent 6c3a05e127
commit 76487f0241
1 changed files with 56 additions and 40 deletions
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96
drivers/block/z2ram.c
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@ -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) {