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: 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 14:48:10 -07:00 коммит произвёл Linus Torvalds
Родитель 80d7ef6614
Коммит 7eae74af32
1 изменённых файлов: 45 добавлений и 31 удалений

Просмотреть файл

@ -3286,6 +3286,37 @@ oom:
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)))
ret = __do_fault(vma, address, pgoff, flags, &fault_page);
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);
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;