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Commit a41b70d6 authored by Jan Kara's avatar Jan Kara Committed by Linus Torvalds
Browse files

mm: use vmf->page during WP faults 

So far we set vmf->page during WP faults only when we needed to pass it
to the ->page_mkwrite handler.  Set it in all the cases now and use that
instead of passing page pointer explicitly around.

Link: http://lkml.kernel.org/r/1479460644-25076-14-git-send-email-jack@suse.cz


Signed-off-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 38b8cb7f

mm/memory.c

+29 −29
Original line number Diff line number Diff line
@@ -2102,11 +2102,12 @@ static void fault_dirty_shared_page(struct vm_area_struct *vma, 
 * case, all we need to do here is to mark the page as writable and update

 * any related book-keeping.

 */

static inline int wp_page_reuse(struct vm_fault *vmf, struct page *page,

static inline int wp_page_reuse(struct vm_fault *vmf,

				int page_mkwrite, int dirty_shared)

	__releases(vmf->ptl)

{

	struct vm_area_struct *vma = vmf->vma;

	struct page *page = vmf->page;

	pte_t entry;

	/*

	 * Clear the pages cpupid information as the existing
@@ -2150,10 +2151,11 @@ static inline int wp_page_reuse(struct vm_fault *vmf, struct page *page, 
 *   held to the old page, as well as updating the rmap.

 * - In any case, unlock the PTL and drop the reference we took to the old page.

 */

static int wp_page_copy(struct vm_fault *vmf, struct page *old_page)

static int wp_page_copy(struct vm_fault *vmf)

{

	struct vm_area_struct *vma = vmf->vma;

	struct mm_struct *mm = vma->vm_mm;

	struct page *old_page = vmf->page;

	struct page *new_page = NULL;

	pte_t entry;

	int page_copied = 0;
@@ -2305,26 +2307,25 @@ static int wp_pfn_shared(struct vm_fault *vmf) 
			return 0;

		}

	}

	return wp_page_reuse(vmf, NULL, 0, 0);

	return wp_page_reuse(vmf, 0, 0);

}



static int wp_page_shared(struct vm_fault *vmf, struct page *old_page)

static int wp_page_shared(struct vm_fault *vmf)

	__releases(vmf->ptl)

{

	struct vm_area_struct *vma = vmf->vma;

	int page_mkwrite = 0;



	get_page(old_page);

	get_page(vmf->page);



	if (vma->vm_ops && vma->vm_ops->page_mkwrite) {

		int tmp;



		pte_unmap_unlock(vmf->pte, vmf->ptl);

		vmf->page = old_page;

		tmp = do_page_mkwrite(vmf);

		if (unlikely(!tmp || (tmp &

				      (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {

			put_page(old_page);

			put_page(vmf->page);

			return tmp;

		}

		/*
@@ -2336,15 +2337,15 @@ static int wp_page_shared(struct vm_fault *vmf, struct page *old_page) 
		vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,

						vmf->address, &vmf->ptl);

		if (!pte_same(*vmf->pte, vmf->orig_pte)) {

			unlock_page(old_page);

			unlock_page(vmf->page);

			pte_unmap_unlock(vmf->pte, vmf->ptl);

			put_page(old_page);

			put_page(vmf->page);

			return 0;

		}

		page_mkwrite = 1;

	}



	return wp_page_reuse(vmf, old_page, page_mkwrite, 1);

	return wp_page_reuse(vmf, page_mkwrite, 1);

}



/*
@@ -2369,10 +2370,9 @@ static int do_wp_page(struct vm_fault *vmf) 
	__releases(vmf->ptl)

{

	struct vm_area_struct *vma = vmf->vma;

	struct page *old_page;



	old_page = vm_normal_page(vma, vmf->address, vmf->orig_pte);

	if (!old_page) {

	vmf->page = vm_normal_page(vma, vmf->address, vmf->orig_pte);

	if (!vmf->page) {

		/*

		 * VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a

		 * VM_PFNMAP VMA.
@@ -2385,30 +2385,30 @@ static int do_wp_page(struct vm_fault *vmf) 
			return wp_pfn_shared(vmf);



		pte_unmap_unlock(vmf->pte, vmf->ptl);

		return wp_page_copy(vmf, old_page);

		return wp_page_copy(vmf);

	}



	/*

	 * Take out anonymous pages first, anonymous shared vmas are

	 * not dirty accountable.

	 */

	if (PageAnon(old_page) && !PageKsm(old_page)) {

	if (PageAnon(vmf->page) && !PageKsm(vmf->page)) {

		int total_mapcount;

		if (!trylock_page(old_page)) {

			get_page(old_page);

		if (!trylock_page(vmf->page)) {

			get_page(vmf->page);

			pte_unmap_unlock(vmf->pte, vmf->ptl);

			lock_page(old_page);

			lock_page(vmf->page);

			vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,

					vmf->address, &vmf->ptl);

			if (!pte_same(*vmf->pte, vmf->orig_pte)) {

				unlock_page(old_page);

				unlock_page(vmf->page);

				pte_unmap_unlock(vmf->pte, vmf->ptl);

				put_page(old_page);

				put_page(vmf->page);

				return 0;

			}

			put_page(old_page);

			put_page(vmf->page);

		}

		if (reuse_swap_page(old_page, &total_mapcount)) {

		if (reuse_swap_page(vmf->page, &total_mapcount)) {

			if (total_mapcount == 1) {

				/*

				 * The page is all ours. Move it to
@@ -2417,24 +2417,24 @@ static int do_wp_page(struct vm_fault *vmf) 
				 * Protected against the rmap code by

				 * the page lock.

				 */

				page_move_anon_rmap(old_page, vma);

				page_move_anon_rmap(vmf->page, vma);

			}

			unlock_page(old_page);

			return wp_page_reuse(vmf, old_page, 0, 0);

			unlock_page(vmf->page);

			return wp_page_reuse(vmf, 0, 0);

		}

		unlock_page(old_page);

		unlock_page(vmf->page);

	} else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==

					(VM_WRITE|VM_SHARED))) {

		return wp_page_shared(vmf, old_page);

		return wp_page_shared(vmf);

	}



	/*

	 * Ok, we need to copy. Oh, well..

	 */

	get_page(old_page);

	get_page(vmf->page);



	pte_unmap_unlock(vmf->pte, vmf->ptl);

	return wp_page_copy(vmf, old_page);

	return wp_page_copy(vmf);

}



static void unmap_mapping_range_vma(struct vm_area_struct *vma,