コード例 #1
0
ファイル: dm.c プロジェクト: wxlong/Test
/*
 * Allocate and initialise a blank device with a given minor.
 */
static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
{
	int r;
	struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL);

	if (!md) {
		DMWARN("unable to allocate device, out of memory.");
		return NULL;
	}

	/* get a minor number for the dev */
	r = persistent ? specific_minor(minor) : next_free_minor(&minor);
	if (r < 0)
		goto bad1;

	memset(md, 0, sizeof(*md));
	init_rwsem(&md->lock);
	rwlock_init(&md->map_lock);
	atomic_set(&md->holders, 1);

	md->queue = blk_alloc_queue(GFP_KERNEL);
	if (!md->queue)
		goto bad1;

	md->queue->queuedata = md;
	md->queue->backing_dev_info.congested_fn = dm_any_congested;
	md->queue->backing_dev_info.congested_data = md;
	blk_queue_make_request(md->queue, dm_request);
	md->queue->unplug_fn = dm_unplug_all;

	md->io_pool = mempool_create(MIN_IOS, mempool_alloc_slab,
				     mempool_free_slab, _io_cache);
 	if (!md->io_pool)
 		goto bad2;

	md->tio_pool = mempool_create(MIN_IOS, mempool_alloc_slab,
				      mempool_free_slab, _tio_cache);
	if (!md->tio_pool)
		goto bad3;

	md->disk = alloc_disk(1);
	if (!md->disk)
		goto bad4;

	md->disk->major = _major;
	md->disk->first_minor = minor;
	md->disk->fops = &dm_blk_dops;
	md->disk->queue = md->queue;
	md->disk->private_data = md;
	sprintf(md->disk->disk_name, "dm-%d", minor);
	add_disk(md->disk);

	atomic_set(&md->pending, 0);
	init_waitqueue_head(&md->wait);
	init_waitqueue_head(&md->eventq);

	return md;

 bad4:
	mempool_destroy(md->tio_pool);
 bad3:
	mempool_destroy(md->io_pool);
 bad2:
	blk_put_queue(md->queue);
	free_minor(minor);
 bad1:
	kfree(md);
	return NULL;
}
コード例 #2
0
ファイル: dm.c プロジェクト: 3sOx/asuswrt-merlin
/*
 * Allocate and initialise a blank device with a given minor.
 */
static struct mapped_device *alloc_dev(int minor)
{
	int r;
	struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL);
	void *old_md;

	if (!md) {
		DMWARN("unable to allocate device, out of memory.");
		return NULL;
	}

	if (!try_module_get(THIS_MODULE))
		goto bad0;

	/* get a minor number for the dev */
	if (minor == DM_ANY_MINOR)
		r = next_free_minor(md, &minor);
	else
		r = specific_minor(md, minor);
	if (r < 0)
		goto bad1;

	memset(md, 0, sizeof(*md));
	init_rwsem(&md->io_lock);
	init_MUTEX(&md->suspend_lock);
	spin_lock_init(&md->pushback_lock);
	rwlock_init(&md->map_lock);
	atomic_set(&md->holders, 1);
	atomic_set(&md->open_count, 0);
	atomic_set(&md->event_nr, 0);

	md->queue = blk_alloc_queue(GFP_KERNEL);
	if (!md->queue)
		goto bad1_free_minor;

	md->queue->queuedata = md;
	md->queue->backing_dev_info.congested_fn = dm_any_congested;
	md->queue->backing_dev_info.congested_data = md;
	blk_queue_make_request(md->queue, dm_request);
	blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
	md->queue->unplug_fn = dm_unplug_all;
	md->queue->issue_flush_fn = dm_flush_all;

	md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache);
	if (!md->io_pool)
		goto bad2;

	md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache);
	if (!md->tio_pool)
		goto bad3;

	md->bs = bioset_create(16, 16);
	if (!md->bs)
		goto bad_no_bioset;

	md->disk = alloc_disk(1);
	if (!md->disk)
		goto bad4;

	atomic_set(&md->pending, 0);
	init_waitqueue_head(&md->wait);
	init_waitqueue_head(&md->eventq);

	md->disk->major = _major;
	md->disk->first_minor = minor;
	md->disk->fops = &dm_blk_dops;
	md->disk->queue = md->queue;
	md->disk->private_data = md;
	sprintf(md->disk->disk_name, "dm-%d", minor);
	add_disk(md->disk);
	format_dev_t(md->name, MKDEV(_major, minor));

	/* Populate the mapping, nobody knows we exist yet */
	spin_lock(&_minor_lock);
	old_md = idr_replace(&_minor_idr, md, minor);
	spin_unlock(&_minor_lock);

	BUG_ON(old_md != MINOR_ALLOCED);

	return md;

 bad4:
	bioset_free(md->bs);
 bad_no_bioset:
	mempool_destroy(md->tio_pool);
 bad3:
	mempool_destroy(md->io_pool);
 bad2:
	blk_cleanup_queue(md->queue);
 bad1_free_minor:
	free_minor(minor);
 bad1:
	module_put(THIS_MODULE);
 bad0:
	kfree(md);
	return NULL;
}