X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fmm%2Ffilemap.c;fp=kernel%2Fmm%2Ffilemap.c;h=91dc614cb9d53923f32bc09bf49e3df51b6fdd8f;hb=52f993b8e89487ec9ee15a7fb4979e0f09a45b27;hp=44301361c100b8126fa54983a5af8b1bc507a7c6;hpb=c189ccac5702322ed843fe17057035b7222a59b6;p=kvmfornfv.git

diff --git a/kernel/mm/filemap.c b/kernel/mm/filemap.c
index 44301361c..91dc614cb 100644
--- a/kernel/mm/filemap.c
+++ b/kernel/mm/filemap.c
@@ -109,6 +109,51 @@
  *   ->tasklist_lock            (memory_failure, collect_procs_ao)
  */
 
+static int page_cache_tree_insert(struct address_space *mapping,
+				  struct page *page, void **shadowp)
+{
+	struct radix_tree_node *node;
+	void **slot;
+	int error;
+
+	error = __radix_tree_create(&mapping->page_tree, page->index,
+				    &node, &slot);
+	if (error)
+		return error;
+	if (*slot) {
+		void *p;
+
+		p = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
+		if (!radix_tree_exceptional_entry(p))
+			return -EEXIST;
+		if (shadowp)
+			*shadowp = p;
+		mapping->nrshadows--;
+		if (node)
+			workingset_node_shadows_dec(node);
+	}
+	radix_tree_replace_slot(slot, page);
+	mapping->nrpages++;
+	if (node) {
+		workingset_node_pages_inc(node);
+		/*
+		 * Don't track node that contains actual pages.
+		 *
+		 * Avoid acquiring the list_lru lock if already
+		 * untracked.  The list_empty() test is safe as
+		 * node->private_list is protected by
+		 * mapping->tree_lock.
+		 */
+		if (!list_empty(&node->private_list)) {
+			local_lock(workingset_shadow_lock);
+			list_lru_del(&__workingset_shadow_nodes,
+				     &node->private_list);
+			local_unlock(workingset_shadow_lock);
+		}
+	}
+	return 0;
+}
+
 static void page_cache_tree_delete(struct address_space *mapping,
 				   struct page *page, void *shadow)
 {
@@ -122,6 +167,14 @@ static void page_cache_tree_delete(struct address_space *mapping,
 
 	__radix_tree_lookup(&mapping->page_tree, page->index, &node, &slot);
 
+	if (!node) {
+		/*
+		 * We need a node to properly account shadow
+		 * entries. Don't plant any without. XXX
+		 */
+		shadow = NULL;
+	}
+
 	if (shadow) {
 		mapping->nrshadows++;
 		/*
@@ -540,9 +593,8 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
 		memcg = mem_cgroup_begin_page_stat(old);
 		spin_lock_irqsave(&mapping->tree_lock, flags);
 		__delete_from_page_cache(old, NULL, memcg);
-		error = radix_tree_insert(&mapping->page_tree, offset, new);
+		error = page_cache_tree_insert(mapping, new, NULL);
 		BUG_ON(error);
-		mapping->nrpages++;
 
 		/*
 		 * hugetlb pages do not participate in page cache accounting.
@@ -564,51 +616,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
 }
 EXPORT_SYMBOL_GPL(replace_page_cache_page);
 
-static int page_cache_tree_insert(struct address_space *mapping,
-				  struct page *page, void **shadowp)
-{
-	struct radix_tree_node *node;
-	void **slot;
-	int error;
-
-	error = __radix_tree_create(&mapping->page_tree, page->index,
-				    &node, &slot);
-	if (error)
-		return error;
-	if (*slot) {
-		void *p;
-
-		p = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
-		if (!radix_tree_exceptional_entry(p))
-			return -EEXIST;
-		if (shadowp)
-			*shadowp = p;
-		mapping->nrshadows--;
-		if (node)
-			workingset_node_shadows_dec(node);
-	}
-	radix_tree_replace_slot(slot, page);
-	mapping->nrpages++;
-	if (node) {
-		workingset_node_pages_inc(node);
-		/*
-		 * Don't track node that contains actual pages.
-		 *
-		 * Avoid acquiring the list_lru lock if already
-		 * untracked.  The list_empty() test is safe as
-		 * node->private_list is protected by
-		 * mapping->tree_lock.
-		 */
-		if (!list_empty(&node->private_list)) {
-			local_lock(workingset_shadow_lock);
-			list_lru_del(&__workingset_shadow_nodes,
-				     &node->private_list);
-			local_unlock(workingset_shadow_lock);
-		}
-	}
-	return 0;
-}
-
 static int __add_to_page_cache_locked(struct page *page,
 				      struct address_space *mapping,
 				      pgoff_t offset, gfp_t gfp_mask,
@@ -1557,6 +1564,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
 
 		cond_resched();
 find_page:
+		if (fatal_signal_pending(current)) {
+			error = -EINTR;
+			goto out;
+		}
+
 		page = find_get_page(mapping, index);
 		if (!page) {
 			page_cache_sync_readahead(mapping,