[patch 2/4] mspec: convert nopfn to fault

[Nick Piggin <npiggin@suse.de>]

---

 drivers/char/mspec.c |   22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

Index: linux-2.6/drivers/char/mspec.c
===================================================================
--- linux-2.6.orig/drivers/char/mspec.c
+++ linux-2.6/drivers/char/mspec.c
@@ -193,25 +193,24 @@ mspec_close(struct vm_area_struct *vma)
 }
 
 /*
- * mspec_nopfn
+ * mspec_fault
  *
  * Creates a mspec page and maps it to user space.
  */
-static unsigned long
-mspec_nopfn(struct vm_area_struct *vma, unsigned long address)
+static int
+mspec_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	unsigned long paddr, maddr;
 	unsigned long pfn;
+	pgoff_t index = vmf->pgoff;
 	int index;
 	struct vma_data *vdata = vma->vm_private_data;
 
-	BUG_ON(address < vdata->vm_start || address >= vdata->vm_end);
-	index = (address - vdata->vm_start) >> PAGE_SHIFT;
 	maddr = (volatile unsigned long) vdata->maddr[index];
 	if (maddr == 0) {
 		maddr = uncached_alloc_page(numa_node_id(), 1);
 		if (maddr == 0)
-			return NOPFN_OOM;
+			return VM_FAULT_OOM;
 
 		spin_lock(&vdata->lock);
 		if (vdata->maddr[index] == 0) {
@@ -231,13 +230,20 @@ mspec_nopfn(struct vm_area_struct *vma, 
 
 	pfn = paddr >> PAGE_SHIFT;
 
-	return pfn;
+	/*
+	 * vm_insert_pfn can fail with -EBUSY, but in that case it will
+	 * be because another thread has installed the pte first, so it
+	 * is no problem.
+	 */
+	vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
+
+	return VM_FAULT_NOPAGE;
 }
 
 static struct vm_operations_struct mspec_vm_ops = {
 	.open = mspec_open,
 	.close = mspec_close,
-	.nopfn = mspec_nopfn
+	.fault = mspec_fault,
 };
 
 /*

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