forked from Minki/linux
mm: consolidate code to call vm_ops->page_mkwrite()
There are two functions which need to call vm_ops->page_mkwrite(): do_shared_fault() and do_wp_page(). We can consolidate preparation code. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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parent
f0c6d4d295
commit
fb09a46425
99
mm/memory.c
99
mm/memory.c
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@ -2586,6 +2586,38 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo
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copy_user_highpage(dst, src, va, vma);
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}
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/*
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* Notify the address space that the page is about to become writable so that
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* it can prohibit this or wait for the page to get into an appropriate state.
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*
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* We do this without the lock held, so that it can sleep if it needs to.
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*/
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static int do_page_mkwrite(struct vm_area_struct *vma, struct page *page,
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unsigned long address)
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{
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struct vm_fault vmf;
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int ret;
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vmf.virtual_address = (void __user *)(address & PAGE_MASK);
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vmf.pgoff = page->index;
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vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
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vmf.page = page;
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ret = vma->vm_ops->page_mkwrite(vma, &vmf);
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if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
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return ret;
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if (unlikely(!(ret & VM_FAULT_LOCKED))) {
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lock_page(page);
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if (!page->mapping) {
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unlock_page(page);
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return 0; /* retry */
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}
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ret |= VM_FAULT_LOCKED;
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} else
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VM_BUG_ON_PAGE(!PageLocked(page), page);
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return ret;
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}
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/*
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* This routine handles present pages, when users try to write
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* to a shared page. It is done by copying the page to a new address
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@ -2668,42 +2700,15 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
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* get_user_pages(.write=1, .force=1).
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*/
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if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
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struct vm_fault vmf;
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int tmp;
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vmf.virtual_address = (void __user *)(address &
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PAGE_MASK);
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vmf.pgoff = old_page->index;
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vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
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vmf.page = old_page;
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/*
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* Notify the address space that the page is about to
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* become writable so that it can prohibit this or wait
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* for the page to get into an appropriate state.
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*
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* We do this without the lock held, so that it can
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* sleep if it needs to.
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*/
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page_cache_get(old_page);
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pte_unmap_unlock(page_table, ptl);
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tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
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if (unlikely(tmp &
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(VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
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ret = tmp;
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goto unwritable_page;
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tmp = do_page_mkwrite(vma, old_page, address);
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if (unlikely(!tmp || (tmp &
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(VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
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page_cache_release(old_page);
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return tmp;
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}
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if (unlikely(!(tmp & VM_FAULT_LOCKED))) {
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lock_page(old_page);
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if (!old_page->mapping) {
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ret = 0; /* retry the fault */
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unlock_page(old_page);
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goto unwritable_page;
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}
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} else
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VM_BUG_ON_PAGE(!PageLocked(old_page), old_page);
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/*
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* Since we dropped the lock we need to revalidate
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* the PTE as someone else may have changed it. If
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@ -2892,10 +2897,6 @@ oom:
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if (old_page)
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page_cache_release(old_page);
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return VM_FAULT_OOM;
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unwritable_page:
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page_cache_release(old_page);
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return ret;
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}
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static void unmap_mapping_range_vma(struct vm_area_struct *vma,
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@ -3419,7 +3420,6 @@ static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
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spinlock_t *ptl;
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pte_t entry, *pte;
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int dirtied = 0;
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struct vm_fault vmf;
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int ret, tmp;
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ret = __do_fault(vma, address, pgoff, flags, &fault_page);
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@ -3430,31 +3430,16 @@ static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
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* Check if the backing address space wants to know that the page is
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* about to become writable
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*/
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if (!vma->vm_ops->page_mkwrite)
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goto set_pte;
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if (vma->vm_ops->page_mkwrite) {
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unlock_page(fault_page);
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vmf.virtual_address = (void __user *)(address & PAGE_MASK);
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vmf.pgoff = pgoff;
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vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
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vmf.page = fault_page;
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tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
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if (unlikely(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
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tmp = do_page_mkwrite(vma, fault_page, address);
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if (unlikely(!tmp ||
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(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
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page_cache_release(fault_page);
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return tmp;
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}
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if (unlikely(!(tmp & VM_FAULT_LOCKED))) {
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lock_page(fault_page);
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if (!fault_page->mapping) {
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unlock_page(fault_page);
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page_cache_release(fault_page);
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return 0; /* retry */
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}
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} else
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VM_BUG_ON_PAGE(!PageLocked(fault_page), fault_page);
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set_pte:
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pte = pte_offset_map_lock(mm, pmd, address, &ptl);
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if (unlikely(!pte_same(*pte, orig_pte))) {
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pte_unmap_unlock(pte, ptl);
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