2 files changed, 8 insertions, 2 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 0d1e59a86e49..a0dff34dd437 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -1070,6 +1070,7 @@ u64 find_lock_delalloc_range(struct extent_map_tree *tree,
 search_again:
         node = tree_search(&tree->state, cur_start);
         if (!node || IS_ERR(node)) {
+                *end = (u64)-1;
                 goto out;
         }
 
@@ -1079,6 +1080,8 @@ search_again:
                         goto out;
                 }
                 if (!(state->state & EXTENT_DELALLOC)) {
+                        if (!found)
+                                *end = state->end;
                         goto out;
                 }
                 if (!found) {
@@ -1841,8 +1844,10 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
                 nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start,
                                                        &delalloc_end,
                                                        128 * 1024 * 1024);
-                if (nr_delalloc <= 0)
-                        break;
+                if (nr_delalloc == 0) {
+                        delalloc_start = delalloc_end + 1;
+                        continue;
+                }
                 tree->ops->fill_delalloc(inode, delalloc_start,
                                          delalloc_end);
                 clear_extent_bit(tree, delalloc_start,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1e725a48467c..55b2e1426024 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -798,6 +798,7 @@ static int btrfs_cow_one_page(struct inode *inode, struct page *page,
         u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
         u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
 
+        WARN_ON(!PageLocked(page));
         set_page_extent_mapped(page);
 
         lock_extent(em_tree, page_start, page_end, GFP_NOFS);