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, 28 insertions, 11 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index febc6295c7a..f92b297e7da 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2640,6 +2640,7 @@ static int noinline relocate_inode_pages(struct inode *inode, u64 start,
         struct file_ra_state *ra;
         unsigned long total_read = 0;
         unsigned long ra_pages;
+        struct btrfs_ordered_extent *ordered;
         struct btrfs_trans_handle *trans;
 
         ra = kzalloc(sizeof(*ra), GFP_NOFS);
@@ -2658,9 +2659,9 @@ static int noinline relocate_inode_pages(struct inode *inode, u64 start,
                                        calc_ra(i, last_index, ra_pages));
                 }
                 total_read++;
-                if (((u64)i << PAGE_CACHE_SHIFT) > inode->i_size)
+again:
+                if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
                         goto truncate_racing;
-
                 page = grab_cache_page(inode->i_mapping, i);
                 if (!page) {
                         goto out_unlock;
@@ -2674,18 +2675,24 @@ static int noinline relocate_inode_pages(struct inode *inode, u64 start,
                                 goto out_unlock;
                         }
                 }
-#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);
                 set_page_dirty(page);
@@ -2694,10 +2701,18 @@ static int noinline relocate_inode_pages(struct inode *inode, u64 start,
                 unlock_page(page);
                 page_cache_release(page);
         }
-        balance_dirty_pages_ratelimited_nr(inode->i_mapping,
-                                           total_read);
 
 out_unlock:
+        /* we have to start the IO in order to get the ordered extents
+         * instantiated.  This allows the relocation to code to wait
+         * for all the ordered extents to hit the disk.
+         *
+         * Otherwise, it would constantly loop over the same extents
+         * because the old ones don't get deleted  until the IO is
+         * started
+         */
+        btrfs_fdatawrite_range(inode->i_mapping, start, start + len - 1,
+                               WB_SYNC_NONE);
         kfree(ra);
         trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1);
         if (trans) {
@@ -3238,6 +3253,8 @@ next:
 
                 btrfs_clean_old_snapshots(tree_root);
 
+                btrfs_wait_ordered_extents(tree_root);
+
                 trans = btrfs_start_transaction(tree_root, 1);
                 btrfs_commit_transaction(trans, tree_root);
                 mutex_lock(&root->fs_info->alloc_mutex);