ocfs2: manually d_move() during ocfs2_rename()

Make use of FS_RENAME_DOES_D_MOVE to avoid a race condition that can occur
during ->rename() if we d_move() outside of the parent directory cluster
locks, and another node discovers the new name (created during the rename)
and unlinks it. d_move() will unconditionally rehash a dentry - which will
leave stale data in the system.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

2 files changed, 5 insertions, 2 deletions

diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index 09efe240e652..18a31906316e 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -414,7 +414,7 @@ void ocfs2_dentry_move(struct dentry *dentry, struct dentry *target,
          * XXX: Is there any advantage to dropping the lock here?
          */
         if (old_dir == new_dir)
-                return;
+                goto out_move;
 
         ocfs2_dentry_lock_put(osb, dentry->d_fsdata);
 
@@ -423,6 +423,9 @@ void ocfs2_dentry_move(struct dentry *dentry, struct dentry *target,
                                        OCFS2_I(new_dir)->ip_blkno, 0);
         if (ret)
                 mlog_errno(ret);
+
+out_move:
+        d_move(dentry, target);
 }
 
 struct dentry_operations ocfs2_dentry_ops = {
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index d17e33e66a1e..33a6de6fc612 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -682,7 +682,7 @@ static struct file_system_type ocfs2_fs_type = {
         .kill_sb        = kill_block_super, /* set to the generic one
                                              * right now, but do we
                                              * need to change that? */
-        .fs_flags       = FS_REQUIRES_DEV,
+        .fs_flags       = FS_REQUIRES_DEV|FS_RENAME_DOES_D_MOVE,
         .next           = NULL
 };