Btrfs: Cleanup and comment ordered-data.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 0d1e2ba47a9c..f37e09e724f7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1343,7 +1343,7 @@ again:
                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
                 unlock_page(page);
                 page_cache_release(page);
-                btrfs_wait_ordered_extent(inode, ordered);
+                btrfs_start_ordered_extent(inode, ordered, 1);
                 btrfs_put_ordered_extent(ordered);
                 goto again;
         }
@@ -2660,6 +2660,10 @@ static void btrfs_invalidatepage(struct page *page, unsigned long offset)
         ordered = btrfs_lookup_ordered_extent(page->mapping->host,
                                            page_offset(page));
         if (ordered) {
+                /*
+                 * IO on this page will never be started, so we need
+                 * to account for any ordered extents now
+                 */
                 clear_extent_bit(tree, page_start, page_end,
                                  EXTENT_DIRTY | EXTENT_DELALLOC |
                                  EXTENT_LOCKED, 1, 0, GFP_NOFS);
@@ -2732,11 +2736,15 @@ again:
         lock_extent(io_tree, page_start, page_end, GFP_NOFS);
         set_page_extent_mapped(page);
 
+        /*
+         * we can't set the delalloc bits if there are pending ordered
+         * extents.  Drop our locks and wait for them to finish
+         */
         ordered = btrfs_lookup_ordered_extent(inode, page_start);
         if (ordered) {
                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
                 unlock_page(page);
-                btrfs_wait_ordered_extent(inode, ordered);
+                btrfs_start_ordered_extent(inode, ordered, 1);
                 btrfs_put_ordered_extent(ordered);
                 goto again;
         }