Btrfs: Fix the defragmention code and the block relocation code for data=ordered

Before setting an extent to delalloc, the code needs to wait for
pending ordered extents.

Also, the relocation code needs to wait for ordered IO before scanning
the block group again.  This is because the extents are not removed
until the IO for the new extents is finished

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

1 files changed, 14 insertions, 7 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 83f17a5cbd6a..a61f2e7e2db5 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -213,6 +213,7 @@ int btrfs_defrag_file(struct file *file)
 	struct inode *inode = fdentry(file)->d_inode;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	struct btrfs_ordered_extent *ordered;
 	struct page *page;
 	unsigned long last_index;
 	unsigned long ra_pages = root->fs_info->bdi.ra_pages;
@@ -234,6 +235,7 @@ int btrfs_defrag_file(struct file *file)
 				       min(last_index, i + ra_pages - 1));
 		}
 		total_read++;
+again:
 		page = grab_cache_page(inode->i_mapping, i);
 		if (!page)
 			goto out_unlock;
@@ -247,18 +249,23 @@ int btrfs_defrag_file(struct file *file)
 			}
 		}
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
-		ClearPageDirty(page);
-#else
-		cancel_dirty_page(page, PAGE_CACHE_SIZE);
-#endif
 		wait_on_page_writeback(page);
-		set_page_extent_mapped(page);
 
 		page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 		page_end = page_start + PAGE_CACHE_SIZE - 1;
-
 		lock_extent(io_tree, page_start, page_end, GFP_NOFS);
+
+		ordered = btrfs_lookup_ordered_extent(inode, page_start);
+		if (ordered) {
+			unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+			unlock_page(page);
+			page_cache_release(page);
+			btrfs_start_ordered_extent(inode, ordered, 1);
+			btrfs_put_ordered_extent(ordered);
+			goto again;
+		}
+		set_page_extent_mapped(page);
+
 		set_extent_delalloc(io_tree, page_start,
 				    page_end, GFP_NOFS);