[PATCH 12/20] mm: Pass vm_fault structure into do_page_mkwrite()

[Jan Kara <jack@xxxxxxx>]

We will need more information in the ->page_mkwrite() helper for DAX to
be able to fully finish faults there. Pass vm_fault structure to
do_page_mkwrite() and use it there so that information propagates
properly from upper layers.

Reviewed-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
 mm/memory.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 139e115acf35..6d4e1b1cea51 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2038,20 +2038,17 @@ static gfp_t __get_fault_gfp_mask(struct vm_area_struct *vma)
  *
  * We do this without the lock held, so that it can sleep if it needs to.
  */
-static int do_page_mkwrite(struct vm_area_struct *vma, struct page *page,
-	       unsigned long address)
+static int do_page_mkwrite(struct vm_fault *vmf)
 {
-	struct vm_fault vmf;
 	int ret;
+	struct page *page = vmf->page;
+	unsigned int old_flags = vmf->flags;
 
-	vmf.address = address & PAGE_MASK;
-	vmf.pgoff = page->index;
-	vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
-	vmf.gfp_mask = __get_fault_gfp_mask(vma);
-	vmf.page = page;
-	vmf.cow_page = NULL;
+	vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
 
-	ret = vma->vm_ops->page_mkwrite(vma, &vmf);
+	ret = vmf->vma->vm_ops->page_mkwrite(vmf->vma, vmf);
+	/* Restore original flags so that caller is not surprised */
+	vmf->flags = old_flags;
 	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
 		return ret;
 	if (unlikely(!(ret & VM_FAULT_LOCKED))) {
@@ -2327,7 +2324,8 @@ static int wp_page_shared(struct vm_fault *vmf, struct page *old_page)
 		int tmp;
 
 		pte_unmap_unlock(vmf->pte, vmf->ptl);
-		tmp = do_page_mkwrite(vma, old_page, vmf->address);
+		vmf->page = old_page;
+		tmp = do_page_mkwrite(vmf);
 		if (unlikely(!tmp || (tmp &
 				      (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
 			put_page(old_page);
@@ -3289,7 +3287,7 @@ static int do_shared_fault(struct vm_fault *vmf)
 	 */
 	if (vma->vm_ops->page_mkwrite) {
 		unlock_page(vmf->page);
-		tmp = do_page_mkwrite(vma, vmf->page, vmf->address);
+		tmp = do_page_mkwrite(vmf);
 		if (unlikely(!tmp ||
 				(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
 			put_page(vmf->page);
-- 
2.6.6

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