Commit 76b9e23d authored Nov 10, 2011 by Miao Xie Committed by Chris Mason Nov 10, 2011

Btrfs: fix orphan backref nodes



If the root node of a fs/file tree is in the block group that is
being relocated, but the others are not in the other block groups.
when we create a snapshot for this tree between the relocation tree
creation ends and ->create_reloc_tree is set to 0, Btrfs will create
some backref nodes that are the lowest nodes of the backrefs cache.
But we forget to add them into ->leaves list of the backref cache
and deal with them, and at last, they will triggered BUG_ON().

  kernel BUG at fs/btrfs/relocation.c:239!

This patch fixes it by adding them into ->leaves list of backref cache.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

parent 61b520a9

fs/btrfs/relocation.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1174,6 +1174,8 @@ static int clone_backref_node(struct btrfs_trans_handle *trans,
		list_add_tail(&new_edge->list[UPPER],
		&new_node->lower);
		}
		} else {
		list_add_tail(&new_node->lower, &cache->leaves);
		}

		rb_node = tree_insert(&cache->rb_root, new_node->bytenr,

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