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>
diff --git a/mm/memory.c b/mm/memory.c
index 144e8cd..af76397 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3286,6 +3286,37 @@
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 @@
{
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 @@
} 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 @@
* 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 @@
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;