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Commit 7eae74af authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds
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mm: do_fault(): extract to call vm_ops->do_fault() to separate function 



Extract code to vm_ops->do_fault() and basic error handling to separate
function.  The code will be reused.

Signed-off-by: default avatarKirill 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 80d7ef66

mm/memory.c

+45 −31
Original line number Diff line number Diff line
@@ -3286,6 +3286,37 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, 
	return VM_FAULT_OOM;

}



static int __do_fault(struct vm_area_struct *vma, unsigned long address,

		pgoff_t pgoff, unsigned int flags, struct page **page)

{

	struct vm_fault vmf;

	int ret;



	vmf.virtual_address = (void __user *)(address & PAGE_MASK);

	vmf.pgoff = pgoff;

	vmf.flags = flags;

	vmf.page = NULL;



	ret = vma->vm_ops->fault(vma, &vmf);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))

		return ret;



	if (unlikely(PageHWPoison(vmf.page))) {

		if (ret & VM_FAULT_LOCKED)

			unlock_page(vmf.page);

		page_cache_release(vmf.page);

		return VM_FAULT_HWPOISON;

	}



	if (unlikely(!(ret & VM_FAULT_LOCKED)))

		lock_page(vmf.page);

	else

		VM_BUG_ON_PAGE(!PageLocked(vmf.page), vmf.page);



	*page = vmf.page;

	return ret;

}



/*

 * do_fault() tries to create a new page mapping. It aggressively

 * tries to share with existing pages, but makes a separate copy if
@@ -3305,12 +3336,11 @@ static int do_fault(struct mm_struct *mm, struct vm_area_struct *vma, 
{

	pte_t *page_table;

	spinlock_t *ptl;

	struct page *page;

	struct page *page, *fault_page;

	struct page *cow_page;

	pte_t entry;

	int anon = 0;

	struct page *dirty_page = NULL;

	struct vm_fault vmf;

	int ret;

	int page_mkwrite = 0;
@@ -3334,42 +3364,19 @@ static int do_fault(struct mm_struct *mm, struct vm_area_struct *vma, 
	} else

		cow_page = NULL;



	vmf.virtual_address = (void __user *)(address & PAGE_MASK);

	vmf.pgoff = pgoff;

	vmf.flags = flags;

	vmf.page = NULL;



	ret = vma->vm_ops->fault(vma, &vmf);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE |

			    VM_FAULT_RETRY)))

		goto uncharge_out;



	if (unlikely(PageHWPoison(vmf.page))) {

		if (ret & VM_FAULT_LOCKED)

			unlock_page(vmf.page);

		ret = VM_FAULT_HWPOISON;

		page_cache_release(vmf.page);

	ret = __do_fault(vma, address, pgoff, flags, &fault_page);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))

		goto uncharge_out;

	}



	/*

	 * For consistency in subsequent calls, make the faulted page always

	 * locked.

	 */

	if (unlikely(!(ret & VM_FAULT_LOCKED)))

		lock_page(vmf.page);

	else

		VM_BUG_ON_PAGE(!PageLocked(vmf.page), vmf.page);



	/*

	 * Should we do an early C-O-W break?

	 */

	page = vmf.page;

	page = fault_page;

	if (flags & FAULT_FLAG_WRITE) {

		if (!(vma->vm_flags & VM_SHARED)) {

			page = cow_page;

			anon = 1;

			copy_user_highpage(page, vmf.page, address, vma);

			copy_user_highpage(page, fault_page, address, vma);

			__SetPageUptodate(page);

		} else {

			/*
@@ -3378,8 +3385,15 @@ static int do_fault(struct mm_struct *mm, struct vm_area_struct *vma, 
			 * to become writable

			 */

			if (vma->vm_ops->page_mkwrite) {

				struct vm_fault vmf;

				int tmp;



				vmf.virtual_address =

					(void __user *)(address & PAGE_MASK);

				vmf.pgoff = pgoff;

				vmf.flags = flags;

				vmf.page = fault_page;



				unlock_page(page);

				vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;

				tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
@@ -3469,9 +3483,9 @@ static int do_fault(struct mm_struct *mm, struct vm_area_struct *vma, 
		if (vma->vm_file && !page_mkwrite)

			file_update_time(vma->vm_file);

	} else {

		unlock_page(vmf.page);

		unlock_page(fault_page);

		if (anon)

			page_cache_release(vmf.page);

			page_cache_release(fault_page);

	}



	return ret;