From 01eacb277909de942abbdff37584ad331e3893fe Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Thu, 4 Dec 2014 18:38:30 +0000 Subject: [PATCH] Btrfs: always clear a block group node when removing it from the tree Always clear a block group's rbnode after removing it from the rbtree to ensure that any tasks that might be holding a reference on the block group don't end up accessing stale rbnode left and right child pointers through next_block_group(). This is a leftover from the change titled: "Btrfs: fix invalid block group rbtree access after bg is removed" Signed-off-by: Filipe Manana Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 222d6aea4a8..974b3edf69c 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -8872,6 +8872,7 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info) cache_node); rb_erase(&block_group->cache_node, &info->block_group_cache_tree); + RB_CLEAR_NODE(&block_group->cache_node); spin_unlock(&info->block_group_cache_lock); down_write(&block_group->space_info->groups_sem); @@ -9130,6 +9131,7 @@ int btrfs_read_block_groups(struct btrfs_root *root) spin_lock(&info->block_group_cache_lock); rb_erase(&cache->cache_node, &info->block_group_cache_tree); + RB_CLEAR_NODE(&cache->cache_node); spin_unlock(&info->block_group_cache_lock); btrfs_put_block_group(cache); goto error; @@ -9271,6 +9273,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, spin_lock(&root->fs_info->block_group_cache_lock); rb_erase(&cache->cache_node, &root->fs_info->block_group_cache_tree); + RB_CLEAR_NODE(&cache->cache_node); spin_unlock(&root->fs_info->block_group_cache_lock); btrfs_put_block_group(cache); return ret; -- 2.41.0