From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 17AAF36E477 for ; Sun, 6 Sep 2026 16:12:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788711122; cv=none; b=gGMX+9lsL55wVGgrZcmel+bQOouyBvKCzYSQm2I5B6giuOk7VvW5mHLaUIcC/TgsGuMCdmwNlnYPc3bf2FiaXPqvr6+TswiRpslAXhjLm54AQ2oTGiRKNIU7cPzqM3kjRTY6sG/k6GKMoZQqkzrqXtkW7hvNAEMtZ///ffnMIYU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788711122; c=relaxed/simple; bh=aDjA6lBgGR0b7XhD/cHdSoNnSfZ/Tx78pjvL/H8JiI0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sGbHHaK2ZdItcY9/7QwhI0CBeIdfd5Xl8UlKjGR0Lz+D+NKTXRUDIiigPTBPron6n30Nm5ZjxAJp9YLvGF1xZ/yFyOJeYykkTmQpFQVOeLtuw+kycnJiCL7J3SsbEUYmvnB5PavQl4YP10q48pbbD4U7FXjBf+zMNMAUTx74p8M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ajJ8N7E3; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ajJ8N7E3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B09A81F00ACA; Sun, 6 Sep 2026 16:11:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788711120; bh=KpGjRysMRHgQLQY2bizg4BEICrN4H8PE6alZOI1cwUM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ajJ8N7E39CoRUdosY3Flb0Qk2g9w+lzt5yCPd2W/W6+QdK6nQ2aezXnQ1TtoytDbH vBIDSCRmYd1jVlo2TLJBQhosMBaC2Sf98JZ6Zv3KHBq2JdBDGK6CVRs/nBpeQKtE+x IqcHPqMWGLFI/AeQilImvReUKT5SHCynf3VqJDbUK7kdtXUo+RbTUUc+v2KHxUEEji qiaOzJf468eg29VxcBiKaF2f2VtYJpQnp7IfVEfBlVDJyPC3P7mPfvg/jz/l7PqA2H EL7Ehjd+QexulG1OcWZUDGjHd/P77ME4EQ9d9To0VIwW7hSSTzP9QIwayjF/0fxFS0 yEMmxx7qIe3VQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Guanghui Yang <3497809730@qq.com>, David Sterba , Sasha Levin Subject: [PATCH 6.1.y 4/4] btrfs: drop recovered reloc root refs on recovery failure Date: Sun, 6 Sep 2026 12:11:56 -0400 Message-ID: <20260906161156.1545411-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260906161156.1545411-1-sashal@kernel.org> References: <2026090359-float-gamma-d28d@gregkh> <20260906161156.1545411-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Guanghui Yang <3497809730@qq.com> [ Upstream commit 6d8ba4572922e336f0b59a80751b018e1e135164 ] During relocation recovery, each fs root gets a reference to its relocation root. If loading or adding a later root fails, or if the first transaction commit fails, btrfs_recover_relocation() jumps to out_unset before merge_reloc_roots() and clean_dirty_subvols(). put_reloc_control() drops the list-owned relocation root references, but it does not clear fs_root->reloc_root or drop the references owned by those pointers. Mount cleanup only drops them when BTRFS_FS_ERROR is set, so an error such as -ENOMEM while processing a later root can leave references behind. Keep temporary references to the fs roots associated during recovery. On failure, clear their reloc_root pointers and drop the corresponding references. Once the first transaction commit succeeds, drop only the temporary fs root references and let the normal merge and cleanup paths handle the relocation roots. Fault injection on a pending-relocation image confirmed the cleanup gap. With an injected first-commit failure, 25 fs roots had reloc_root set with fs_error=0. With this fix, the same failure path drops that count to 0 before mount fails. Fixes: f44deb7442ed ("btrfs: hold a ref on the root->reloc_root") CC: stable@vger.kernel.org Signed-off-by: Guanghui Yang <3497809730@qq.com> Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/relocation.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 8ec3f03605e4b..613b00a99d76b 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -4205,6 +4205,24 @@ static noinline_for_stack int mark_garbage_root(struct btrfs_root *root) return ret; } +static void release_recovered_fs_roots(struct list_head *roots, bool drop_reloc_refs) +{ + struct btrfs_root *root; + struct btrfs_root *next; + + list_for_each_entry_safe(root, next, roots, reloc_dirty_list) { + list_del_init(&root->reloc_dirty_list); + if (drop_reloc_refs) { + struct btrfs_root *reloc_root = root->reloc_root; + + ASSERT(reloc_root); + root->reloc_root = NULL; + btrfs_put_root(reloc_root); + } + btrfs_put_root(root); + } +} + /* * recover relocation interrupted by system crash. * @@ -4214,6 +4232,7 @@ static noinline_for_stack int mark_garbage_root(struct btrfs_root *root) int btrfs_recover_relocation(struct btrfs_fs_info *fs_info) { LIST_HEAD(reloc_roots); + LIST_HEAD(recovered_roots); struct btrfs_key key; struct btrfs_root *fs_root; struct btrfs_root *reloc_root; @@ -4326,7 +4345,7 @@ int btrfs_recover_relocation(struct btrfs_fs_info *fs_info) ret = PTR_ERR(fs_root); list_add_tail(&reloc_root->root_list, &reloc_roots); btrfs_end_transaction(trans); - goto out_unset; + goto out_drop_reloc_refs; } ret = __add_reloc_root(reloc_root); @@ -4335,15 +4354,17 @@ int btrfs_recover_relocation(struct btrfs_fs_info *fs_info) list_add_tail(&reloc_root->root_list, &reloc_roots); btrfs_put_root(fs_root); btrfs_end_transaction(trans); - goto out_unset; + goto out_drop_reloc_refs; } + ASSERT(list_empty(&fs_root->reloc_dirty_list)); fs_root->reloc_root = btrfs_grab_root(reloc_root); - btrfs_put_root(fs_root); + list_add_tail(&fs_root->reloc_dirty_list, &recovered_roots); } ret = btrfs_commit_transaction(trans); if (ret) - goto out_unset; + goto out_drop_reloc_refs; + release_recovered_fs_roots(&recovered_roots, false); merge_reloc_roots(rc); @@ -4359,6 +4380,8 @@ int btrfs_recover_relocation(struct btrfs_fs_info *fs_info) ret2 = clean_dirty_subvols(rc); if (ret2 < 0 && !ret) ret = ret2; +out_drop_reloc_refs: + release_recovered_fs_roots(&recovered_roots, true); out_unset: unset_reloc_control(rc); reloc_chunk_end(fs_info); -- 2.53.0