1 files changed, 43 insertions, 45 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 8d9b19f239c3..59ffcdbde8b3 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -761,23 +761,22 @@ int __set_page_dirty_nobuffers(struct page *page)
                 struct address_space *mapping = page_mapping(page);
                 struct address_space *mapping2;
 
-                if (mapping) {
-                        write_lock_irq(&mapping->tree_lock);
-                        mapping2 = page_mapping(page);
-                        if (mapping2) { /* Race with truncate? */
-                                BUG_ON(mapping2 != mapping);
-                                if (mapping_cap_account_dirty(mapping))
-                                        __inc_zone_page_state(page,
-                                                                NR_FILE_DIRTY);
-                                radix_tree_tag_set(&mapping->page_tree,
-                                        page_index(page), PAGECACHE_TAG_DIRTY);
-                        }
-                        write_unlock_irq(&mapping->tree_lock);
-                        if (mapping->host) {
-                                /* !PageAnon && !swapper_space */
-                                __mark_inode_dirty(mapping->host,
-                                                        I_DIRTY_PAGES);
-                        }
+                if (!mapping)
+                        return 1;
+
+                write_lock_irq(&mapping->tree_lock);
+                mapping2 = page_mapping(page);
+                if (mapping2) { /* Race with truncate? */
+                        BUG_ON(mapping2 != mapping);
+                        if (mapping_cap_account_dirty(mapping))
+                                __inc_zone_page_state(page, NR_FILE_DIRTY);
+                        radix_tree_tag_set(&mapping->page_tree,
+                                page_index(page), PAGECACHE_TAG_DIRTY);
+                }
+                write_unlock_irq(&mapping->tree_lock);
+                if (mapping->host) {
+                        /* !PageAnon && !swapper_space */
+                        __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
                 }
                 return 1;
         }
@@ -851,27 +850,26 @@ int test_clear_page_dirty(struct page *page)
         struct address_space *mapping = page_mapping(page);
         unsigned long flags;
 
-        if (mapping) {
-                write_lock_irqsave(&mapping->tree_lock, flags);
-                if (TestClearPageDirty(page)) {
-                        radix_tree_tag_clear(&mapping->page_tree,
-                                                page_index(page),
-                                                PAGECACHE_TAG_DIRTY);
-                        write_unlock_irqrestore(&mapping->tree_lock, flags);
-                        /*
-                         * We can continue to use `mapping' here because the
-                         * page is locked, which pins the address_space
-                         */
-                        if (mapping_cap_account_dirty(mapping)) {
-                                page_mkclean(page);
-                                dec_zone_page_state(page, NR_FILE_DIRTY);
-                        }
-                        return 1;
-                }
+        if (!mapping)
+                return TestClearPageDirty(page);
+
+        write_lock_irqsave(&mapping->tree_lock, flags);
+        if (TestClearPageDirty(page)) {
+                radix_tree_tag_clear(&mapping->page_tree,
+                                page_index(page), PAGECACHE_TAG_DIRTY);
                 write_unlock_irqrestore(&mapping->tree_lock, flags);
-                return 0;
+                /*
+                 * We can continue to use `mapping' here because the
+                 * page is locked, which pins the address_space
+                 */
+                if (mapping_cap_account_dirty(mapping)) {
+                        page_mkclean(page);
+                        dec_zone_page_state(page, NR_FILE_DIRTY);
+                }
+                return 1;
         }
-        return TestClearPageDirty(page);
+        write_unlock_irqrestore(&mapping->tree_lock, flags);
+        return 0;
 }
 EXPORT_SYMBOL(test_clear_page_dirty);
 
@@ -893,17 +891,17 @@ int clear_page_dirty_for_io(struct page *page)
 {
         struct address_space *mapping = page_mapping(page);
 
-        if (mapping) {
-                if (TestClearPageDirty(page)) {
-                        if (mapping_cap_account_dirty(mapping)) {
-                                page_mkclean(page);
-                                dec_zone_page_state(page, NR_FILE_DIRTY);
-                        }
-                        return 1;
+        if (!mapping)
+                return TestClearPageDirty(page);
+
+        if (TestClearPageDirty(page)) {
+                if (mapping_cap_account_dirty(mapping)) {
+                        page_mkclean(page);
+                        dec_zone_page_state(page, NR_FILE_DIRTY);
                 }
-                return 0;
+                return 1;
         }
-        return TestClearPageDirty(page);
+        return 0;
 }
 EXPORT_SYMBOL(clear_page_dirty_for_io);