Btrfs: update to the right index of defragment

When we use autodefrag, we forget to update the index which indicates
the last page we've dirty.  And we'll set dirty flags on a same set of
pages again and again.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index afde837..18cc23d 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1186,6 +1186,9 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
                        if (newer_off == (u64)-1)
                                break;
 
+                       if (ret > 0)
+                               i += ret;
+
                        newer_off = max(newer_off + 1,
                                        (u64)i << PAGE_CACHE_SHIFT);