From 95b656592f88012d07975c6bc49ebc3f8410b1a8 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 23 Jul 2013 16:57:15 -0400 Subject: [PATCH] Btrfs: cleanup reloc roots properly on error I was hitting the BUG_ON() at the end of merge_reloc_roots() because we were aborting the transaction at some point previously and then getting an error when we tried to drop the reloc root. I fixed btrfs_drop_snapshot to re-add us to the dead roots list if we failed, but this isn't the right thing to do for reloc roots since it uses root->root_list for it's own stuff in order to know what needs to be cleaned up. So fix btrfs_drop_snapshot to only do the re-add if we aren't dropping for reloc, and handle errors from merge_reloc_root() by dropping the reloc root we are processing since it won't be on the list of roots to cleanup. With this patch my reproducer no longer panics. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 2 +- fs/btrfs/relocation.c | 7 ++++++- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index ca02d3c1724c9..e868c35f760ca 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7696,7 +7696,7 @@ out: * don't have it in the radix (like when we recover after a power fail * or unmount) so we don't leak memory. */ - if (root_dropped == false) + if (!for_reloc && root_dropped == false) btrfs_add_dead_root(root); if (err) btrfs_std_error(root->fs_info, err); diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 295a6115c3268..5a23d875ab407 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -2314,8 +2314,13 @@ again: BUG_ON(root->reloc_root != reloc_root); ret = merge_reloc_root(rc, root); - if (ret) + if (ret) { + __update_reloc_root(reloc_root, 1); + free_extent_buffer(reloc_root->node); + free_extent_buffer(reloc_root->commit_root); + kfree(reloc_root); goto out; + } } else { list_del_init(&reloc_root->root_list); } -- 2.39.5