X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=mm%2Ffilemap.c;h=7c00f105845ebb2601dd6083eb32046f91b06f32;hb=15dbc136dff62ebefb03353cfb7d308d49b275f3;hp=8e629c4ef0c8b0298865c775b490b698e667480e;hpb=62cccb8c8e7a3ca233f49d5e7dcb1557d25465cd;p=linux-2.6-block.git

diff --git a/mm/filemap.c b/mm/filemap.c
index 8e629c4ef0c8..7c00f105845e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -176,8 +176,7 @@ static void page_cache_tree_delete(struct address_space *mapping,
 /*
  * Delete a page from the page cache and free it. Caller has to make
  * sure the page is locked and that nobody else uses it - or that usage
- * is safe.  The caller must hold the mapping's tree_lock and
- * lock_page_memcg().
+ * is safe.  The caller must hold the mapping's tree_lock.
  */
 void __delete_from_page_cache(struct page *page, void *shadow)
 {
@@ -260,11 +259,9 @@ void delete_from_page_cache(struct page *page)
 
 	freepage = mapping->a_ops->freepage;
 
-	lock_page_memcg(page);
 	spin_lock_irqsave(&mapping->tree_lock, flags);
 	__delete_from_page_cache(page, NULL);
 	spin_unlock_irqrestore(&mapping->tree_lock, flags);
-	unlock_page_memcg(page);
 
 	if (freepage)
 		freepage(page);
@@ -557,7 +554,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
 		new->mapping = mapping;
 		new->index = offset;
 
-		lock_page_memcg(old);
 		spin_lock_irqsave(&mapping->tree_lock, flags);
 		__delete_from_page_cache(old, NULL);
 		error = radix_tree_insert(&mapping->page_tree, offset, new);
@@ -572,7 +568,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
 		if (PageSwapBacked(new))
 			__inc_zone_page_state(new, NR_SHMEM);
 		spin_unlock_irqrestore(&mapping->tree_lock, flags);
-		unlock_page_memcg(old);
 		mem_cgroup_migrate(old, new);
 		radix_tree_preload_end();
 		if (freepage)
@@ -591,7 +586,7 @@ static int page_cache_tree_insert(struct address_space *mapping,
 	void **slot;
 	int error;
 
-	error = __radix_tree_create(&mapping->page_tree, page->index,
+	error = __radix_tree_create(&mapping->page_tree, page->index, 0,
 				    &node, &slot);
 	if (error)
 		return error;
@@ -1260,7 +1255,6 @@ unsigned find_get_entries(struct address_space *mapping,
 		return 0;
 
 	rcu_read_lock();
-restart:
 	radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
 		struct page *page;
 repeat:
@@ -1268,8 +1262,10 @@ repeat:
 		if (unlikely(!page))
 			continue;
 		if (radix_tree_exception(page)) {
-			if (radix_tree_deref_retry(page))
-				goto restart;
+			if (radix_tree_deref_retry(page)) {
+				slot = radix_tree_iter_retry(&iter);
+				continue;
+			}
 			/*
 			 * A shadow entry of a recently evicted page, a swap
 			 * entry from shmem/tmpfs or a DAX entry.  Return it
@@ -1322,7 +1318,6 @@ unsigned find_get_pages(struct address_space *mapping, pgoff_t start,
 		return 0;
 
 	rcu_read_lock();
-restart:
 	radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
 		struct page *page;
 repeat:
@@ -1332,13 +1327,8 @@ repeat:
 
 		if (radix_tree_exception(page)) {
 			if (radix_tree_deref_retry(page)) {
-				/*
-				 * Transient condition which can only trigger
-				 * when entry at index 0 moves out of or back
-				 * to root: none yet gotten, safe to restart.
-				 */
-				WARN_ON(iter.index);
-				goto restart;
+				slot = radix_tree_iter_retry(&iter);
+				continue;
 			}
 			/*
 			 * A shadow entry of a recently evicted page,
@@ -1389,7 +1379,6 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
 		return 0;
 
 	rcu_read_lock();
-restart:
 	radix_tree_for_each_contig(slot, &mapping->page_tree, &iter, index) {
 		struct page *page;
 repeat:
@@ -1400,12 +1389,8 @@ repeat:
 
 		if (radix_tree_exception(page)) {
 			if (radix_tree_deref_retry(page)) {
-				/*
-				 * Transient condition which can only trigger
-				 * when entry at index 0 moves out of or back
-				 * to root: none yet gotten, safe to restart.
-				 */
-				goto restart;
+				slot = radix_tree_iter_retry(&iter);
+				continue;
 			}
 			/*
 			 * A shadow entry of a recently evicted page,
@@ -1465,7 +1450,6 @@ unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
 		return 0;
 
 	rcu_read_lock();
-restart:
 	radix_tree_for_each_tagged(slot, &mapping->page_tree,
 				   &iter, *index, tag) {
 		struct page *page;
@@ -1476,12 +1460,8 @@ repeat:
 
 		if (radix_tree_exception(page)) {
 			if (radix_tree_deref_retry(page)) {
-				/*
-				 * Transient condition which can only trigger
-				 * when entry at index 0 moves out of or back
-				 * to root: none yet gotten, safe to restart.
-				 */
-				goto restart;
+				slot = radix_tree_iter_retry(&iter);
+				continue;
 			}
 			/*
 			 * A shadow entry of a recently evicted page.
@@ -1544,7 +1524,6 @@ unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start,
 		return 0;
 
 	rcu_read_lock();
-restart:
 	radix_tree_for_each_tagged(slot, &mapping->page_tree,
 				   &iter, start, tag) {
 		struct page *page;
@@ -1554,12 +1533,8 @@ repeat:
 			continue;
 		if (radix_tree_exception(page)) {
 			if (radix_tree_deref_retry(page)) {
-				/*
-				 * Transient condition which can only trigger
-				 * when entry at index 0 moves out of or back
-				 * to root: none yet gotten, safe to restart.
-				 */
-				goto restart;
+				slot = radix_tree_iter_retry(&iter);
+				continue;
 			}
 
 			/*
@@ -2176,10 +2151,11 @@ repeat:
 		if (unlikely(!page))
 			goto next;
 		if (radix_tree_exception(page)) {
-			if (radix_tree_deref_retry(page))
-				break;
-			else
-				goto next;
+			if (radix_tree_deref_retry(page)) {
+				slot = radix_tree_iter_retry(&iter);
+				continue;
+			}
+			goto next;
 		}
 
 		if (!page_cache_get_speculative(page))