block/partitions/core.c

Source file repositories/reference/linux-study-clean/block/partitions/core.c

File Facts

System
Linux kernel
Corpus path
block/partitions/core.c
Extension
.c
Size
17653 bytes
Lines
734
Domain
Representative Device Path
Bucket
PCIe NVMe Storage Path
Inferred role
Representative Device Path: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Part of the selected hardware vertical slice: PCI discovery, driver binding, NVMe queues, block requests, DMA, interrupts, and completion.

Dependency Surface

Detected Declarations

Annotated Snippet

err = device_add(pdev);
	if (err)
		goto out_put;

	err = -ENOMEM;
	bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);
	if (!bdev->bd_holder_dir)
		goto out_del;

	dev_set_uevent_suppress(pdev, 0);
	if (flags & ADDPART_FLAG_WHOLEDISK) {
		err = device_create_file(pdev, &dev_attr_whole_disk);
		if (err)
			goto out_del;
	}

	if (flags & ADDPART_FLAG_READONLY)
		bdev_set_flag(bdev, BD_READ_ONLY);

	/* everything is up and running, commence */
	err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);
	if (err)
		goto out_del;
	bdev_add(bdev, devt);

	/* suppress uevent if the disk suppresses it */
	if (!dev_get_uevent_suppress(ddev))
		kobject_uevent(&pdev->kobj, KOBJ_ADD);
	return bdev;

out_del:
	kobject_put(bdev->bd_holder_dir);
	device_del(pdev);
out_put:
	put_device(pdev);
	return ERR_PTR(err);
out_put_disk:
	put_disk(disk);
	return ERR_PTR(err);
}

static bool partition_overlaps(struct gendisk *disk, sector_t start,
		sector_t length, int skip_partno)
{
	struct block_device *part;
	bool overlap = false;
	unsigned long idx;

	rcu_read_lock();
	xa_for_each_start(&disk->part_tbl, idx, part, 1) {
		if (bdev_partno(part) != skip_partno &&
		    start < part->bd_start_sect + bdev_nr_sectors(part) &&
		    start + length > part->bd_start_sect) {
			overlap = true;
			break;
		}
	}
	rcu_read_unlock();

	return overlap;
}

int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
		sector_t length)
{
	struct block_device *part;
	int ret;

	mutex_lock(&disk->open_mutex);
	if (!disk_live(disk)) {
		ret = -ENXIO;
		goto out;
	}

	if (disk->flags & GENHD_FL_NO_PART) {
		ret = -EINVAL;
		goto out;
	}

	if (partition_overlaps(disk, start, length, -1)) {
		ret = -EBUSY;
		goto out;
	}

	part = add_partition(disk, partno, start, length,
			ADDPART_FLAG_NONE, NULL);
	ret = PTR_ERR_OR_ZERO(part);
out:
	mutex_unlock(&disk->open_mutex);
	return ret;

Annotation

Implementation Notes