From 3e6ff34afc7ec7a6156e58502b5a56771517cf93 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Fri, 18 Sep 2026 11:58:00 +0100 Subject: [PATCH] btrfs: clear BTRFS_ROOT_IN_TRANS_SETUP on early exit from record_root_in_trans() If we exit early because the transaction that last used the root already matches the current transaction, we leave the BTRFS_ROOT_IN_TRANS_SETUP bit set in the root (which we just set right before the exit). While this does not cause any functional issue, it makes callers of btrfs_record_root_in_trans() lock fs_info->reloc_mutex and call record_root_in_trans() for nothing, causing unnecessary lock contention, until one of them clears the bit in record_root_in_trans(). One caller of btrfs_record_root_in_trans() is start_transaction(), used to start new transaction or joining an existing one, which is a hot path. So clear BTRFS_ROOT_IN_TRANS_SETUP on early exit. Assisted-by: LLM Reviewed-by: Boris Burkov Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Signed-off-by: David Sterba --- fs/btrfs/transaction.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 6802b94ed76f..11b38133f737 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -432,6 +432,7 @@ static int record_root_in_trans(struct btrfs_trans_handle *trans, spin_lock(&fs_info->fs_roots_radix_lock); if (btrfs_get_root_last_trans(root) == trans->transid && !force) { spin_unlock(&fs_info->fs_roots_radix_lock); + clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); return 0; } radix_tree_tag_set(&fs_info->fs_roots_radix,