static int nvme_submit_io()

in host/ioctl.c [113:174]

• 51 lines of code
• 13 McCabe index (conditional complexity)

static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
{
	struct nvme_user_io io;
	struct nvme_command c;
	unsigned length, meta_len;
	void __user *metadata;

	if (copy_from_user(&io, uio, sizeof(io)))
		return -EFAULT;
	if (io.flags)
		return -EINVAL;

	switch (io.opcode) {
	case nvme_cmd_write:
	case nvme_cmd_read:
	case nvme_cmd_compare:
		break;
	default:
		return -EINVAL;
	}

	length = (io.nblocks + 1) << ns->lba_shift;

	if ((io.control & NVME_RW_PRINFO_PRACT) &&
	    ns->ms == sizeof(struct t10_pi_tuple)) {
		/*
		 * Protection information is stripped/inserted by the
		 * controller.
		 */
		if (nvme_to_user_ptr(io.metadata))
			return -EINVAL;
		meta_len = 0;
		metadata = NULL;
	} else {
		meta_len = (io.nblocks + 1) * ns->ms;
		metadata = nvme_to_user_ptr(io.metadata);
	}

	if (ns->features & NVME_NS_EXT_LBAS) {
		length += meta_len;
		meta_len = 0;
	} else if (meta_len) {
		if ((io.metadata & 3) || !io.metadata)
			return -EINVAL;
	}

	memset(&c, 0, sizeof(c));
	c.rw.opcode = io.opcode;
	c.rw.flags = io.flags;
	c.rw.nsid = cpu_to_le32(ns->head->ns_id);
	c.rw.slba = cpu_to_le64(io.slba);
	c.rw.length = cpu_to_le16(io.nblocks);
	c.rw.control = cpu_to_le16(io.control);
	c.rw.dsmgmt = cpu_to_le32(io.dsmgmt);
	c.rw.reftag = cpu_to_le32(io.reftag);
	c.rw.apptag = cpu_to_le16(io.apptag);
	c.rw.appmask = cpu_to_le16(io.appmask);

	return nvme_submit_user_cmd(ns->queue, &c,
			nvme_to_user_ptr(io.addr), length,
			metadata, meta_len, lower_32_bits(io.slba), NULL, 0);
}