From 24213fa46c7080c31d79aa2e3e2f0d9480cab700 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 12 Mar 2021 15:25:33 -0500 Subject: [PATCH] btrfs: do proper error handling in merge_reloc_roots We have a BUG_ON() if we get an error back from btrfs_get_fs_root(). This honestly should never fail, as at this point we have a solid coordination of fs root to reloc root, and these roots will all be in memory. But in the name of killing BUG_ON()'s remove these and handle the error condition properly, ASSERT()'ing for developers. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/relocation.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 3b9c9a001d0d..fb5125c8308c 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -1969,8 +1969,29 @@ again: root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, false); if (btrfs_root_refs(&reloc_root->root_item) > 0) { - BUG_ON(IS_ERR(root)); - BUG_ON(root->reloc_root != reloc_root); + if (IS_ERR(root)) { + /* + * For recovery we read the fs roots on mount, + * and if we didn't find the root then we marked + * the reloc root as a garbage root. For normal + * relocation obviously the root should exist in + * memory. However there's no reason we can't + * handle the error properly here just in case. + */ + ASSERT(0); + ret = PTR_ERR(root); + goto out; + } + if (root->reloc_root != reloc_root) { + /* + * This is actually impossible without something + * going really wrong (like weird race condition + * or cosmic rays). + */ + ASSERT(0); + ret = -EINVAL; + goto out; + } ret = merge_reloc_root(rc, root); btrfs_put_root(root); if (ret) { -- 2.11.0