4 files changed, 22 insertions, 10 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 51372a5..6f58911 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2735,7 +2735,8 @@ int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
 	return ret;
 }
 
-int btree_lock_page_hook(struct page *page)
+static int btree_lock_page_hook(struct page *page, void *data,
+				void (*flush_fn)(void *))
 {
 	struct inode *inode = page->mapping->host;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -2752,7 +2753,10 @@ int btree_lock_page_hook(struct page *page)
 	if (!eb)
 		goto out;
 
-	btrfs_tree_lock(eb);
+	if (!btrfs_try_tree_write_lock(eb)) {
+		flush_fn(data);
+		btrfs_tree_lock(eb);
+	}
 	btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 
 	if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
@@ -2767,7 +2771,10 @@ int btree_lock_page_hook(struct page *page)
 	btrfs_tree_unlock(eb);
 	free_extent_buffer(eb);
 out:
-	lock_page(page);
+	if (!trylock_page(page)) {
+		flush_fn(data);
+		lock_page(page);
+	}
 	return 0;
 }
 
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index bec3ea4..e678539 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -83,8 +83,6 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 			     struct btrfs_fs_info *fs_info);
 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 		       struct btrfs_root *root);
-int btree_lock_page_hook(struct page *page);
-
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 void btrfs_init_lockdep(void);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index f284d4e..b40ba75f 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2613,10 +2613,16 @@ retry:
 			 * swizzled back from swapper_space to tmpfs file
 			 * mapping
 			 */
-			if (tree->ops && tree->ops->write_cache_pages_lock_hook)
-				tree->ops->write_cache_pages_lock_hook(page);
-			else
-				lock_page(page);
+			if (tree->ops &&
+			    tree->ops->write_cache_pages_lock_hook) {
+				tree->ops->write_cache_pages_lock_hook(page,
+							       data, flush_fn);
+			} else {
+				if (!trylock_page(page)) {
+					flush_fn(data);
+					lock_page(page);
+				}
+			}
 
 			if (unlikely(page->mapping != mapping)) {
 				unlock_page(page);
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 325a346..cbd4824 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -86,7 +86,8 @@ struct extent_io_ops {
 				  struct extent_state *other);
 	void (*split_extent_hook)(struct inode *inode,
 				  struct extent_state *orig, u64 split);
-	int (*write_cache_pages_lock_hook)(struct page *page);
+	int (*write_cache_pages_lock_hook)(struct page *page, void *data,
+					   void (*flush_fn)(void *));
 };
 
 struct extent_io_tree {