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mm: consolidate code to call vm_ops->page_mkwrite()

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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>
This commit is contained in:
Kirill A. Shutemov 2014-04-03 14:48:15 -07:00 committed by Linus Torvalds
parent f0c6d4d295
commit fb09a46425
1 changed files with 45 additions and 60 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

105
mm/memory.c
View File

@ -2586,6 +2586,38 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo
copy_user_highpage(dst, src, va, vma);
}
/*
* Notify the address space that the page is about to become writable so that
* it can prohibit this or wait for the page to get into an appropriate state.
*
* 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)
{
struct vm_fault vmf;
int ret;
vmf.virtual_address = (void __user *)(address & PAGE_MASK);
vmf.pgoff = page->index;
vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
vmf.page = page;
ret = vma->vm_ops->page_mkwrite(vma, &vmf);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
return ret;
if (unlikely(!(ret & VM_FAULT_LOCKED))) {
lock_page(page);
if (!page->mapping) {
unlock_page(page);
return 0; /* retry */
}
ret |= VM_FAULT_LOCKED;
} else
VM_BUG_ON_PAGE(!PageLocked(page), page);
return ret;
}
/*
* This routine handles present pages, when users try to write
* to a shared page. It is done by copying the page to a new address
@ -2668,42 +2700,15 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
* get_user_pages(.write=1, .force=1).
*/
if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
struct vm_fault vmf;
int tmp;
vmf.virtual_address = (void __user *)(address &
PAGE_MASK);
vmf.pgoff = old_page->index;
vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
vmf.page = old_page;
/*
* Notify the address space that the page is about to
* become writable so that it can prohibit this or wait
* for the page to get into an appropriate state.
*
* We do this without the lock held, so that it can
* sleep if it needs to.
*/
page_cache_get(old_page);
pte_unmap_unlock(page_table, ptl);
tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
if (unlikely(tmp &
(VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
ret = tmp;
goto unwritable_page;
tmp = do_page_mkwrite(vma, old_page, address);
if (unlikely(!tmp || (tmp &
(VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
page_cache_release(old_page);
return tmp;
}
if (unlikely(!(tmp & VM_FAULT_LOCKED))) {
lock_page(old_page);
if (!old_page->mapping) {
ret = 0; /* retry the fault */
unlock_page(old_page);
goto unwritable_page;
}
} else
VM_BUG_ON_PAGE(!PageLocked(old_page), old_page);
/*
* Since we dropped the lock we need to revalidate
* the PTE as someone else may have changed it. If
@ -2892,10 +2897,6 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (old_page)
page_cache_release(old_page);
return VM_FAULT_OOM;
unwritable_page:
page_cache_release(old_page);
return ret;
}
static void unmap_mapping_range_vma(struct vm_area_struct *vma,
@ -3419,7 +3420,6 @@ static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
spinlock_t *ptl;
pte_t entry, *pte;
int dirtied = 0;
struct vm_fault vmf;
int ret, tmp;
ret = __do_fault(vma, address, pgoff, flags, &fault_page);
@ -3430,31 +3430,16 @@ static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
* Check if the backing address space wants to know that the page is
* about to become writable
*/
if (!vma->vm_ops->page_mkwrite)
goto set_pte;
unlock_page(fault_page);
vmf.virtual_address = (void __user *)(address & PAGE_MASK);
vmf.pgoff = pgoff;
vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
vmf.page = fault_page;
tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
if (unlikely(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
page_cache_release(fault_page);
return tmp;
if (vma->vm_ops->page_mkwrite) {
unlock_page(fault_page);
tmp = do_page_mkwrite(vma, fault_page, address);
if (unlikely(!tmp ||
(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
page_cache_release(fault_page);
return tmp;
}
}
if (unlikely(!(tmp & VM_FAULT_LOCKED))) {
lock_page(fault_page);
if (!fault_page->mapping) {
unlock_page(fault_page);
page_cache_release(fault_page);
return 0; /* retry */
}
} else
VM_BUG_ON_PAGE(!PageLocked(fault_page), fault_page);
set_pte:
pte = pte_offset_map_lock(mm, pmd, address, &ptl);
if (unlikely(!pte_same(*pte, orig_pte))) {
pte_unmap_unlock(pte, ptl);