path: root/fs
diff options
authorJosef Bacik <>2013-07-01 16:10:16 -0400
committerGreg Kroah-Hartman <>2013-07-21 18:21:32 -0700
commit7a44bf654d595a523f01664f781633861fc7262d (patch)
tree760becd974cf00008a741b46b4d59d19714baa51 /fs
parentc701343cd0444bd9440a4236331e80f45c75ece2 (diff)
Btrfs: only do the tree_mod_log_free_eb if this is our last ref
commit 7fb7d76f96bfcbea25007d190ba828b18e13d29d upstream. There is another bug in the tree mod log stuff in that we're calling tree_mod_log_free_eb every single time a block is cow'ed. The problem with this is that if this block is shared by multiple snapshots we will call this multiple times per block, so if we go to rewind the mod log for this block we'll BUG_ON() in __tree_mod_log_rewind because we try to rewind a free twice. We only want to call tree_mod_log_free_eb if we are actually freeing the block. With this patch I no longer hit the panic in __tree_mod_log_rewind. Thanks, Reviewed-by: Jan Schmidt <> Signed-off-by: Josef Bacik <> Signed-off-by: Greg Kroah-Hartman <>
Diffstat (limited to 'fs')
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 2543d11b7d8b..7fb054ba1b60 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1089,7 +1089,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
btrfs_set_node_ptr_generation(parent, parent_slot,
- tree_mod_log_free_eb(root->fs_info, buf);
+ if (last_ref)
+ tree_mod_log_free_eb(root->fs_info, buf);
btrfs_free_tree_block(trans, root, buf, parent_start,