static int pmem_attach_disk()

in pmem.c [369:514]

• 128 lines of code
• 20 McCabe index (conditional complexity)

static int pmem_attach_disk(struct device *dev,
		struct nd_namespace_common *ndns)
{
	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
	struct nd_region *nd_region = to_nd_region(dev->parent);
	int nid = dev_to_node(dev), fua;
	struct resource *res = &nsio->res;
	struct range bb_range;
	struct nd_pfn *nd_pfn = NULL;
	struct dax_device *dax_dev;
	struct nd_pfn_sb *pfn_sb;
	struct pmem_device *pmem;
	struct request_queue *q;
	struct gendisk *disk;
	void *addr;
	int rc;

	pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
	if (!pmem)
		return -ENOMEM;

	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
	if (rc)
		return rc;

	/* while nsio_rw_bytes is active, parse a pfn info block if present */
	if (is_nd_pfn(dev)) {
		nd_pfn = to_nd_pfn(dev);
		rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
		if (rc)
			return rc;
	}

	/* we're attaching a block device, disable raw namespace access */
	devm_namespace_disable(dev, ndns);

	dev_set_drvdata(dev, pmem);
	pmem->phys_addr = res->start;
	pmem->size = resource_size(res);
	fua = nvdimm_has_flush(nd_region);
	if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
		dev_warn(dev, "unable to guarantee persistence of writes\n");
		fua = 0;
	}

	if (!devm_request_mem_region(dev, res->start, resource_size(res),
				dev_name(&ndns->dev))) {
		dev_warn(dev, "could not reserve region %pR\n", res);
		return -EBUSY;
	}

	disk = blk_alloc_disk(nid);
	if (!disk)
		return -ENOMEM;
	q = disk->queue;

	pmem->disk = disk;
	pmem->pgmap.owner = pmem;
	pmem->pfn_flags = PFN_DEV;
	if (is_nd_pfn(dev)) {
		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
		addr = devm_memremap_pages(dev, &pmem->pgmap);
		pfn_sb = nd_pfn->pfn_sb;
		pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
		pmem->pfn_pad = resource_size(res) -
			range_len(&pmem->pgmap.range);
		pmem->pfn_flags |= PFN_MAP;
		bb_range = pmem->pgmap.range;
		bb_range.start += pmem->data_offset;
	} else if (pmem_should_map_pages(dev)) {
		pmem->pgmap.range.start = res->start;
		pmem->pgmap.range.end = res->end;
		pmem->pgmap.nr_range = 1;
		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
		addr = devm_memremap_pages(dev, &pmem->pgmap);
		pmem->pfn_flags |= PFN_MAP;
		bb_range = pmem->pgmap.range;
	} else {
		addr = devm_memremap(dev, pmem->phys_addr,
				pmem->size, ARCH_MEMREMAP_PMEM);
		bb_range.start =  res->start;
		bb_range.end = res->end;
	}

	if (IS_ERR(addr)) {
		rc = PTR_ERR(addr);
		goto out;
	}
	pmem->virt_addr = addr;

	blk_queue_write_cache(q, true, fua);
	blk_queue_physical_block_size(q, PAGE_SIZE);
	blk_queue_logical_block_size(q, pmem_sector_size(ndns));
	blk_queue_max_hw_sectors(q, UINT_MAX);
	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
	if (pmem->pfn_flags & PFN_MAP)
		blk_queue_flag_set(QUEUE_FLAG_DAX, q);

	disk->fops		= &pmem_fops;
	disk->private_data	= pmem;
	nvdimm_namespace_disk_name(ndns, disk->disk_name);
	set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
			/ 512);
	if (devm_init_badblocks(dev, &pmem->bb))
		return -ENOMEM;
	nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_range);
	disk->bb = &pmem->bb;

	dax_dev = alloc_dax(pmem, &pmem_dax_ops);
	if (IS_ERR(dax_dev)) {
		rc = PTR_ERR(dax_dev);
		goto out;
	}
	set_dax_nocache(dax_dev);
	set_dax_nomc(dax_dev);
	if (is_nvdimm_sync(nd_region))
		set_dax_synchronous(dax_dev);
	rc = dax_add_host(dax_dev, disk);
	if (rc)
		goto out_cleanup_dax;
	dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
	pmem->dax_dev = dax_dev;

	rc = device_add_disk(dev, disk, pmem_attribute_groups);
	if (rc)
		goto out_remove_host;
	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
		return -ENOMEM;

	nvdimm_check_and_set_ro(disk);

	pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
					  "badblocks");
	if (!pmem->bb_state)
		dev_warn(dev, "'badblocks' notification disabled\n");
	return 0;

out_remove_host:
	dax_remove_host(pmem->disk);
out_cleanup_dax:
	kill_dax(pmem->dax_dev);
	put_dax(pmem->dax_dev);
out:
	blk_cleanup_disk(pmem->disk);
	return rc;
}