static int dax_devmap()

in char/oradax.c [372:400]

• 22 lines of code
• 5 McCabe index (conditional complexity)

static int dax_devmap(struct file *f, struct vm_area_struct *vma)
{
	struct dax_ctx *ctx = (struct dax_ctx *)f->private_data;
	size_t len = vma->vm_end - vma->vm_start;

	dax_dbg("len=0x%lx, flags=0x%lx", len, vma->vm_flags);

	if (ctx->owner != current) {
		dax_dbg("devmap called from wrong thread");
		return -EINVAL;
	}

	if (len != DAX_MMAP_LEN) {
		dax_dbg("len(%lu) != DAX_MMAP_LEN(%d)", len, DAX_MMAP_LEN);
		return -EINVAL;
	}

	/* completion area is mapped read-only for user */
	if (vma->vm_flags & VM_WRITE)
		return -EPERM;
	vma->vm_flags &= ~VM_MAYWRITE;

	if (remap_pfn_range(vma, vma->vm_start, ctx->ca_buf_ra >> PAGE_SHIFT,
			    len, vma->vm_page_prot))
		return -EAGAIN;

	dax_dbg("mmapped completion area at uva 0x%lx", vma->vm_start);
	return 0;
}