From 57a304cfd43b2b4a5b44b8f5dc026abb34183068 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 12 Mar 2021 15:25:30 -0500 Subject: [PATCH] btrfs: do not panic in __add_reloc_root If we have a duplicate entry for a reloc root then we could have fs corruption that resulted in a double allocation. Since this shouldn't happen unless there is corruption, add an ASSERT(ret != -EEXIST) to all of the callers of __add_reloc_root() to catch any logic mistakes for developers, otherwise normal error handling will happen for normal users. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/relocation.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index ec29715..7d68abe 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -638,9 +638,10 @@ static int __must_check __add_reloc_root(struct btrfs_root *root) node->bytenr, &node->rb_node); spin_unlock(&rc->reloc_root_tree.lock); if (rb_node) { - btrfs_panic(fs_info, -EEXIST, + btrfs_err(fs_info, "Duplicate root found for start=%llu while inserting into relocation tree", node->bytenr); + return -EEXIST; } list_add_tail(&root->root_list, &rc->reloc_roots); @@ -882,6 +883,7 @@ int btrfs_init_reloc_root(struct btrfs_trans_handle *trans, return PTR_ERR(reloc_root); ret = __add_reloc_root(reloc_root); + ASSERT(ret != -EEXIST); if (ret) { /* Pairs with create_reloc_root */ btrfs_put_root(reloc_root); @@ -4059,6 +4061,7 @@ int btrfs_recover_relocation(struct btrfs_root *root) } err = __add_reloc_root(reloc_root); + ASSERT(err != -EEXIST); if (err) { list_add_tail(&reloc_root->root_list, &reloc_roots); btrfs_put_root(fs_root); @@ -4279,6 +4282,7 @@ int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans, return PTR_ERR(reloc_root); ret = __add_reloc_root(reloc_root); + ASSERT(ret != -EEXIST); if (ret) { /* Pairs with create_reloc_root */ btrfs_put_root(reloc_root); -- 2.7.4