ubifs: Remove insert_dead_orphan from replaying orphan process

UBIFS will do commit at the end of mounting process(rw mode), dead
orphans(added by insert_dead_orphan in replaying orphan) are deleted
by ubifs_orphan_end_commit(). The only reason why dead orphans are
added into orphan list is that old orpans may be lost when powercut
happens in ubifs_orphan_end_commit():
ubifs_orphan_end_commit  // TNC(updated by orphans) is not written yet
 if (c->cmt_orphans != 0)
  commit_orphans
   consolidate // traverse orphan list
  write_orph_nodes // rewrite all orphans by ubifs_leb_change
  // If dead orphans are not in list, they will be lost when powercut
  // happens, then TNC won't be updated by old orphans in next mounting.
Luckily, the condition 'c->cmt_orphans != 0' will never be true in
mounting process, there can't be new orphans added into orphan list
before mounting returned, but commit will be done at the end of mounting.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Author: Zhihao Cheng

fs/ubifs/orphan.c

@@ -513,51 +513,6 @@ int ubifs_clear_orphans(struct ubifs_info *c)
 	return 0;
 }
 
-/**
- * insert_dead_orphan - insert an orphan.
- * @c: UBIFS file-system description object
- * @inum: orphan inode number
- *
- * This function is a helper to the 'do_kill_orphans()' function. The orphan
- * must be kept until the next commit, so it is added to the rb-tree and the
- * deletion list.
- */
-static int insert_dead_orphan(struct ubifs_info *c, ino_t inum)
-{
-	struct ubifs_orphan *orphan, *o;
-	struct rb_node **p, *parent = NULL;
-
-	orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_KERNEL);
-	if (!orphan)
-		return -ENOMEM;
-	orphan->inum = inum;
-
-	p = &c->orph_tree.rb_node;
-	while (*p) {
-		parent = *p;
-		o = rb_entry(parent, struct ubifs_orphan, rb);
-		if (inum < o->inum)
-			p = &(*p)->rb_left;
-		else if (inum > o->inum)
-			p = &(*p)->rb_right;
-		else {
-			/* Already added - no problem */
-			kfree(orphan);
-			return 0;
-		}
-	}
-	c->tot_orphans += 1;
-	rb_link_node(&orphan->rb, parent, p);
-	rb_insert_color(&orphan->rb, &c->orph_tree);
-	list_add_tail(&orphan->list, &c->orph_list);
-	orphan->del = 1;
-	orphan->dnext = c->orph_dnext;
-	c->orph_dnext = orphan;
-	dbg_mnt("ino %lu, new %d, tot %d", (unsigned long)inum,
-		c->new_orphans, c->tot_orphans);
-	return 0;
-}
-
 /**
  * do_kill_orphans - remove orphan inodes from the index.
  * @c: UBIFS file-system description object
@@ -655,10 +610,6 @@ static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 				if (err)
 					goto out_ro;
 			}
-
-			err = insert_dead_orphan(c, inum);
-			if (err)
-				goto out_free;
 		}
 
 		*last_cmt_no = cmt_no;