From 39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 26 Dec 2022 09:00:40 +0800 Subject: [PATCH] btrfs: always report error in run_one_delayed_ref() Currently we have a btrfs_debug() for run_one_delayed_ref() failure, but if end users hit such problem, there will be no chance that btrfs_debug() is enabled. This can lead to very little useful info for debugging. This patch will: - Add extra info for error reporting Including: * logical bytenr * num_bytes * type * action * ref_mod - Replace the btrfs_debug() with btrfs_err() - Move the error reporting into run_one_delayed_ref() This is to avoid use-after-free, the @node can be freed in the caller. This error should only be triggered at most once. As if run_one_delayed_ref() failed, we trigger the error message, then causing the call chain to error out: btrfs_run_delayed_refs() `- btrfs_run_delayed_refs() `- btrfs_run_delayed_refs_for_head() `- run_one_delayed_ref() And we will abort the current transaction in btrfs_run_delayed_refs(). If we have to run delayed refs for the abort transaction, run_one_delayed_ref() will just cleanup the refs and do nothing, thus no new error messages would be output. Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/extent-tree.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 892d78c1853c..72ba13b027a9 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -1713,6 +1713,11 @@ static int run_one_delayed_ref(struct btrfs_trans_handle *trans, BUG(); if (ret && insert_reserved) btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1); + if (ret < 0) + btrfs_err(trans->fs_info, +"failed to run delayed ref for logical %llu num_bytes %llu type %u action %u ref_mod %d: %d", + node->bytenr, node->num_bytes, node->type, + node->action, node->ref_mod, ret); return ret; } @@ -1954,8 +1959,6 @@ static int btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle *trans, if (ret) { unselect_delayed_ref_head(delayed_refs, locked_ref); btrfs_put_delayed_ref(ref); - btrfs_debug(fs_info, "run_one_delayed_ref returned %d", - ret); return ret; }