diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 48 |
1 files changed, 17 insertions, 31 deletions
diff --git a/mm/memory.c b/mm/memory.c index 0e9b32610655..988d3099a25d 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2005,7 +2005,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, pte_t entry; int ret = 0; int page_mkwrite = 0; - struct page *dirty_page = NULL; + bool dirty_shared = false; unsigned long mmun_start = 0; /* For mmu_notifiers */ unsigned long mmun_end = 0; /* For mmu_notifiers */ struct mem_cgroup *memcg; @@ -2056,6 +2056,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, unlock_page(old_page); } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED))) { + page_cache_get(old_page); /* * Only catch write-faults on shared writable pages, * read-only shared pages can get COWed by @@ -2063,7 +2064,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, */ if (vma->vm_ops && vma->vm_ops->page_mkwrite) { int tmp; - page_cache_get(old_page); + pte_unmap_unlock(page_table, ptl); tmp = do_page_mkwrite(vma, old_page, address); if (unlikely(!tmp || (tmp & @@ -2083,11 +2084,10 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, unlock_page(old_page); goto unlock; } - page_mkwrite = 1; } - dirty_page = old_page; - get_page(dirty_page); + + dirty_shared = true; reuse: /* @@ -2106,43 +2106,29 @@ reuse: pte_unmap_unlock(page_table, ptl); ret |= VM_FAULT_WRITE; - if (!dirty_page) - return ret; - - if (!page_mkwrite) { + if (dirty_shared) { struct address_space *mapping; int dirtied; - lock_page(dirty_page); - dirtied = set_page_dirty(dirty_page); - VM_BUG_ON_PAGE(PageAnon(dirty_page), dirty_page); - mapping = dirty_page->mapping; - unlock_page(dirty_page); + if (!page_mkwrite) + lock_page(old_page); - if (dirtied && mapping) { - /* - * Some device drivers do not set page.mapping - * but still dirty their pages - */ - balance_dirty_pages_ratelimited(mapping); - } + dirtied = set_page_dirty(old_page); + VM_BUG_ON_PAGE(PageAnon(old_page), old_page); + mapping = old_page->mapping; + unlock_page(old_page); + page_cache_release(old_page); - file_update_time(vma->vm_file); - } - put_page(dirty_page); - if (page_mkwrite) { - struct address_space *mapping = dirty_page->mapping; - - set_page_dirty(dirty_page); - unlock_page(dirty_page); - page_cache_release(dirty_page); - if (mapping) { + if ((dirtied || page_mkwrite) && mapping) { /* * Some device drivers do not set page.mapping * but still dirty their pages */ balance_dirty_pages_ratelimited(mapping); } + + if (!page_mkwrite) + file_update_time(vma->vm_file); } return ret; |