mm: pass vm_fault structure into do_page_mkwrite()

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.

Link: http://lkml.kernel.org/r/1479460644-25076-13-git-send-email-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memory.c b/mm/memory.c
index 6fd8278..e8a5278 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2034,20 +2034,17 @@ 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))) {
@@ -2323,7 +2320,8 @@ 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);
@@ -3324,7 +3322,7 @@ 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);