ocfs2: fix race between dio and recover orphan

During direct io the inode will be added to orphan first and then deleted from orphan. There is a race window that the orphan entry will be deleted twice and thus trigger the BUG when validating OCFS2_DIO_ORPHANED_FL in ocfs2_del_inode_from_orphan.

ocfs2_direct_IO_write
...
ocfs2_add_inode_to_orphan
>>>>>>>> race window, another node may rm the file and then down,
this node take care of orphan recovery and clear flag OCFS2_DIO_ORPHANED_FL
ocfs2_del_inode_from_orphan

Take inode mutex lock to fix this case.

---
 fs/ocfs2/journal.c | 2 ++
 1 file changed, 2 insertions(+)

index 8017032..f8206d1 100644
@@ -2172,6 +2172,7 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
 		iter = oi->ip_next_orphan;
 		oi->ip_next_orphan = NULL;
 
+		mutex_lock(&inode->i_mutex);
 		ret = ocfs2_rw_lock(inode, 1);
 		if (ret < 0) {
 			mlog_errno(ret);

@@ -2218,6 +2219,7 @@ unlock_inode:
 unlock_rw:
 		ocfs2_rw_unlock(inode, 1);
 next:
+		mutex_unlock(&inode->i_mutex);
 		iput(inode);
 		brelse(di_bh);
 		di_bh = NULL;

1.8.4.3