relay: nopage

Convert relay from nopage to fault.
Remove redundant vma range checks.
Switch from OOM to SIGBUS if the resource is not available.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 15 deletions

diff --git a/kernel/relay.c b/kernel/relay.c
index 7c0373322f18..d080b9d161a7 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -37,37 +37,31 @@ static void relay_file_mmap_close(struct vm_area_struct *vma)
 }
 
 /*
- * nopage() vm_op implementation for relay file mapping.
+ * fault() vm_op implementation for relay file mapping.
  */
-static struct page *relay_buf_nopage(struct vm_area_struct *vma,
-                                     unsigned long address,
-                                     int *type)
+static int relay_buf_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
         struct page *page;
         struct rchan_buf *buf = vma->vm_private_data;
-        unsigned long offset = address - vma->vm_start;
+        pgoff_t pgoff = vmf->pgoff;
 
-        if (address > vma->vm_end)
-                return NOPAGE_SIGBUS; /* Disallow mremap */
         if (!buf)
-                return NOPAGE_OOM;
+                return VM_FAULT_OOM;
 
-        page = vmalloc_to_page(buf->start + offset);
+        page = vmalloc_to_page(buf->start + (pgoff << PAGE_SHIFT));
         if (!page)
-                return NOPAGE_OOM;
+                return VM_FAULT_SIGBUS;
         get_page(page);
+        vmf->page = page;
 
-        if (type)
-                *type = VM_FAULT_MINOR;
-
-        return page;
+        return 0;
 }
 
 /*
  * vm_ops for relay file mappings.
  */
 static struct vm_operations_struct relay_file_mmap_ops = {
-        .nopage = relay_buf_nopage,
+        .fault = relay_buf_fault,
         .close = relay_file_mmap_close,
 };