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: 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>
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58
mm/memory.c
58
mm/memory.c
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@ -2102,11 +2102,12 @@ static void fault_dirty_shared_page(struct vm_area_struct *vma,
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* case, all we need to do here is to mark the page as writable and update
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* any related book-keeping.
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*/
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static inline int wp_page_reuse(struct vm_fault *vmf, struct page *page,
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static inline int wp_page_reuse(struct vm_fault *vmf,
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int page_mkwrite, int dirty_shared)
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__releases(vmf->ptl)
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{
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struct vm_area_struct *vma = vmf->vma;
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struct page *page = vmf->page;
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pte_t entry;
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/*
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* Clear the pages cpupid information as the existing
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@ -2150,10 +2151,11 @@ static inline int wp_page_reuse(struct vm_fault *vmf, struct page *page,
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* held to the old page, as well as updating the rmap.
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* - In any case, unlock the PTL and drop the reference we took to the old page.
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*/
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static int wp_page_copy(struct vm_fault *vmf, struct page *old_page)
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static int wp_page_copy(struct vm_fault *vmf)
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{
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struct vm_area_struct *vma = vmf->vma;
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struct mm_struct *mm = vma->vm_mm;
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struct page *old_page = vmf->page;
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struct page *new_page = NULL;
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pte_t entry;
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int page_copied = 0;
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@ -2305,26 +2307,25 @@ static int wp_pfn_shared(struct vm_fault *vmf)
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return 0;
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}
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}
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return wp_page_reuse(vmf, NULL, 0, 0);
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return wp_page_reuse(vmf, 0, 0);
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}
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static int wp_page_shared(struct vm_fault *vmf, struct page *old_page)
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static int wp_page_shared(struct vm_fault *vmf)
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__releases(vmf->ptl)
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{
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struct vm_area_struct *vma = vmf->vma;
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int page_mkwrite = 0;
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get_page(old_page);
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get_page(vmf->page);
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if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
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int tmp;
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pte_unmap_unlock(vmf->pte, vmf->ptl);
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vmf->page = old_page;
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tmp = do_page_mkwrite(vmf);
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if (unlikely(!tmp || (tmp &
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(VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
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put_page(old_page);
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put_page(vmf->page);
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return tmp;
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}
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/*
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@ -2336,15 +2337,15 @@ static int wp_page_shared(struct vm_fault *vmf, struct page *old_page)
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vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,
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vmf->address, &vmf->ptl);
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if (!pte_same(*vmf->pte, vmf->orig_pte)) {
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unlock_page(old_page);
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unlock_page(vmf->page);
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pte_unmap_unlock(vmf->pte, vmf->ptl);
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put_page(old_page);
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put_page(vmf->page);
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return 0;
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}
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page_mkwrite = 1;
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}
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return wp_page_reuse(vmf, old_page, page_mkwrite, 1);
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return wp_page_reuse(vmf, page_mkwrite, 1);
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}
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/*
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@ -2369,10 +2370,9 @@ static int do_wp_page(struct vm_fault *vmf)
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__releases(vmf->ptl)
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{
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struct vm_area_struct *vma = vmf->vma;
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struct page *old_page;
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old_page = vm_normal_page(vma, vmf->address, vmf->orig_pte);
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if (!old_page) {
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vmf->page = vm_normal_page(vma, vmf->address, vmf->orig_pte);
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if (!vmf->page) {
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/*
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* VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a
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* VM_PFNMAP VMA.
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@ -2385,30 +2385,30 @@ static int do_wp_page(struct vm_fault *vmf)
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return wp_pfn_shared(vmf);
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pte_unmap_unlock(vmf->pte, vmf->ptl);
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return wp_page_copy(vmf, old_page);
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return wp_page_copy(vmf);
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}
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/*
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* Take out anonymous pages first, anonymous shared vmas are
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* not dirty accountable.
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*/
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if (PageAnon(old_page) && !PageKsm(old_page)) {
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if (PageAnon(vmf->page) && !PageKsm(vmf->page)) {
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int total_mapcount;
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if (!trylock_page(old_page)) {
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get_page(old_page);
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if (!trylock_page(vmf->page)) {
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get_page(vmf->page);
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pte_unmap_unlock(vmf->pte, vmf->ptl);
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lock_page(old_page);
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lock_page(vmf->page);
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vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,
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vmf->address, &vmf->ptl);
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if (!pte_same(*vmf->pte, vmf->orig_pte)) {
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unlock_page(old_page);
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unlock_page(vmf->page);
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pte_unmap_unlock(vmf->pte, vmf->ptl);
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put_page(old_page);
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put_page(vmf->page);
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return 0;
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}
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put_page(old_page);
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put_page(vmf->page);
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}
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if (reuse_swap_page(old_page, &total_mapcount)) {
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if (reuse_swap_page(vmf->page, &total_mapcount)) {
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if (total_mapcount == 1) {
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/*
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* The page is all ours. Move it to
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@ -2417,24 +2417,24 @@ static int do_wp_page(struct vm_fault *vmf)
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* Protected against the rmap code by
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* the page lock.
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*/
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page_move_anon_rmap(old_page, vma);
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page_move_anon_rmap(vmf->page, vma);
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}
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unlock_page(old_page);
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return wp_page_reuse(vmf, old_page, 0, 0);
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unlock_page(vmf->page);
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return wp_page_reuse(vmf, 0, 0);
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}
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unlock_page(old_page);
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unlock_page(vmf->page);
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} else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
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(VM_WRITE|VM_SHARED))) {
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return wp_page_shared(vmf, old_page);
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return wp_page_shared(vmf);
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}
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/*
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* Ok, we need to copy. Oh, well..
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*/
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get_page(old_page);
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get_page(vmf->page);
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pte_unmap_unlock(vmf->pte, vmf->ptl);
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return wp_page_copy(vmf, old_page);
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return wp_page_copy(vmf);
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}
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static void unmap_mapping_range_vma(struct vm_area_struct *vma,
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