While testing my error handling patches, I added a error injection site at btrfs_inc_extent_ref, to validate the error handling I added was doing the correct thing. However I hit a pretty ugly corruption while doing this check, with the following error injection stack trace
btrfs_inc_extent_ref btrfs_copy_root create_reloc_root otrfs_init_reloc_root btrfs_record_root_in_trans btrfs_start_transaction btrfs_update_inode btrfs_update_time touch_atime file_accessed btrfs_file_mmap This is because we do not catch the error from btrfs_inc_extent_ref, which in practice would be -ENOMEM, which means we lose the extent references for a root that has already been allocated and inserted, which is the problem. Fix this by aborting the transaction if we fail to do the reference modification. Signed-off-by: Josef Bacik <jo...@toxicpanda.com> --- fs/btrfs/ctree.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 56e132d825a2..95d9bae764ab 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -221,9 +221,10 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans, ret = btrfs_inc_ref(trans, root, cow, 1); else ret = btrfs_inc_ref(trans, root, cow, 0); - - if (ret) + if (ret) { + btrfs_abort_transaction(trans, ret); return ret; + } btrfs_mark_buffer_dirty(cow); *cow_ret = cow; -- 2.26.2