From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793634153; b=o9e2iCbCH26vMCPIOha6cmJohzda9EJOlPAxMTmyTS1Yrdw1QSI1XSJAHgS3KvkTln0i GKwzHW0qoQNJT9gG7akWlLxduI86oS6ekcjoxA7ZvR+P4iuHBFNUYHJhX3Ix8WzHMZPUw Bdc82JJ3Zm6lIMT96Dwx1B5vDgQ/XavJ2hyLcfdDJprl6N2yavPXocdp383G0Fb6CMsud JHuoFI5oFwbCCYO/bcV3pVAUCtoFYm1bWmAfRzh8aJGDslZ/ibZ2woaxoKHf/TRE4l+/o T/ThR8blSidJkJUg3mzd1lkIItKLhCPHi519iYRv/TX2qcuS3nTa8doaH0sg4s42p6g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793634153; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=XjSmh+d5IwEcuDsBBtJRv27tO5e3qhB6zrPegdKN9fk=; b=CAx+5QLAWGg2pzP4Ap+vqY6QC+6x0ySUf/SlirHMsG0ls2x8fyCoTepwCp7JVuaT3d2i H36xDe2oknIWl/068SeW7R9wCW7g7sSj/3WsgncKrnsABmp4AD4Wdxz4J/lS6msH27Ue1 Jh7yKiRbz9mYXiqiCgE+Ucv4uj90YaHpIUGUn401jr5mQpzx4xQn1mvS6HOMauvYrxIkY 8pnj1iQY9ByFCifx4/TVhKWe3hCuXflKyq2x4+kwcx7j6qkJdIDj4A2xqwLsfw4Zzvmtg S37ZbnRpVFwXIaMFLEr2RkWVdBwYvQLAMsh1iFxLh+kutJa55ts/xvIvI9AsrM8ZiKA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=BX08x75f; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4D41E6076735 for ; Mon, 2 Nov 2026 15:42:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=BX08x75f Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3A4E1F00A16; Mon, 2 Nov 2026 15:42:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793634153; bh=XjSmh+d5IwEcuDsBBtJRv27tO5e3qhB6zrPegdKN9fk=; h=Subject:To:Cc:From:Date; b=BX08x75fk5cPUErpwslAdIa3zCAwXGDwwhGEb8Ay1D6sz7D+O/lxbuMSqCNK54RQ1 2N/fC/iDrV5OXxx3Kem1uBgFe08sS5EY0za1DsAoU255u2Ja5jFaRgSmFz0EFNx6It Wcq4iNzZKbrjmh1Y+kvRrrsaQfD+E9wsSLG2ooxY= Subject: FAILED: patch "[PATCH] ocfs2/dlm: drain join handlers before releasing module text" failed to apply to 5.15-stable tree To: zzzccc427@gmail.com,akpm@linux-foundation.org,baijiaju1990@gmail.com,heming.zhao@suse.com,jjzuming@gmail.com,jlbec@evilplan.org,joseph.qi@linux.alibaba.com,mark@fasheh.com,stable@vger.kernel.org Cc: From: Date: Mon, 02 Nov 2026 16:38:25 +0100 Message-ID: <2026110225-gaming-concerned-8063@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 28f366d84023651e50e32e29931401ba0df3e679 # git commit -s git send-email --to '' --in-reply-to '2026110225-gaming-concerned-8063@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 28f366d84023651e50e32e29931401ba0df3e679 Mon Sep 17 00:00:00 2001 From: Cen Zhang Date: Thu, 22 Oct 2026 17:09:10 +0800 Subject: [PATCH] ocfs2/dlm: drain join handlers before releasing module text The code for a registered DLM handler must remain resident until its last invocation finishes. dlm_unregister_net_handlers() only removes dlm_join_handlers from the o2net registry. o2net_handler_get() takes a kref on the wrapper, but that reference does not pin ocfs2_dlm text. o2net_process_message() calls nh_func after dropping o2net_handler_lock. With CONFIG_OCFS2_FS_O2CB=m, ocfs2_dlm can be loaded independently of ocfs2_stack_o2cb while nodemanager continues handling messages from a configured, heartbeating peer. If no dependent module or module reference prevents normal unload, the following ordering is possible: Receive worker Module unload -------------- ------------- o2net_handler_get() take wrapper kref drop handler lock dlm_exit() unregister handlers release DLM module text call saved nh_func in released module text Use o2net_unregister_and_flush_handler_list() in the shared DLM unregister helper. It first prevents new lookups, then waits for the ordered o2net workqueue to drain, including a concurrent destruction of that queue. The acquired invocation therefore finishes before dlm_exit() returns and the loader releases the callback code. The same helper covers partial registration and dlm_init() error unwind before module memory is released. Skip the drain when the private join-handler list is empty. Early dlm_init() failures can reach this helper before any handler has been published. Partial-registration failure also reaches it a second time after the first call has already unregistered and drained the list. Neither case needs to take o2net_wq_mutex or drain unrelated work. The list is changed only by serialized module init/exit paths; a nonempty list still uses the full unregister-and-flush helper. Oops report as below: Oops: int3: 0000 [#1] SMP KASAN NOPTI CPU: 2 UID: 0 PID: 54 Comm: kworker/u16:3 Not tainted 7.3.0-rc4-next-20260921-pmb-ocfs2-functional-v1+ #1 PREEMPT(lazy) Hardware identification omitted. Workqueue: o2net o2net_rx_until_empty [ocfs2_nodemanager] RIP: 0010:0xffffffffc0423871 [Instruction byte dump omitted.] Register dump omitted. Call Trace: ? o2net_rx_until_empty+0x19b1/0x3300 [ocfs2_nodemanager] ? __pfx_o2net_rx_until_empty+0x10/0x10 [ocfs2_nodemanager] ? lock_acquire+0x190/0x300 ? process_one_work+0x935/0x1b40 ? process_one_work+0x834/0x1b40 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_release+0xc8/0x290 ? srso_alias_return_thunk+0x5/0xfbef5 ? process_one_work+0x9a8/0x1b40 ? __pfx_process_one_work+0x10/0x10 ? lock_acquire+0x190/0x300 ? lock_is_held_type+0x8f/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 ? worker_thread+0x65c/0xe40 ? srso_alias_return_thunk+0x5/0xfbef5 ? __kthread_parkme+0x177/0x220 ? srso_alias_return_thunk+0x5/0xfbef5 ? __pfx_worker_thread+0x10/0x10 ? kthread+0x351/0x460 ? srso_alias_return_thunk+0x5/0xfbef5 ? __pfx_kthread+0x10/0x10 ? ret_from_fork+0x659/0x940 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x74f/0xf70 ? __pfx_kthread+0x10/0x10 ? ret_from_fork_asm+0x1a/0x30 Modules linked in: ocfs2_nodemanager [last unloaded: ocfs2_dlm] ---[ end trace 0000000000000000 ]--- Link: https://lore.kernel.org/pm-ocfs2-objects-candidate-0076-v6-12de5f4628f57fba3be3@gmail.com Fixes: 6714d8e86bf4 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem") Signed-off-by: Cen Zhang Signed-off-by: Andrew Morton Reviewed-by: Joseph Qi Assisted-by: LLM Cc: Mark Fasheh Cc: Joel Becker Cc: Heming Zhao Cc: Jia-Ju Bai Cc: Cc: diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c index 97bb9400e24b..a7dc3da6dfc7 100644 --- a/fs/ocfs2/dlm/dlmdomain.c +++ b/fs/ocfs2/dlm/dlmdomain.c @@ -2215,7 +2215,8 @@ static LIST_HEAD(dlm_join_handlers); static void dlm_unregister_net_handlers(void) { - o2net_unregister_handler_list(&dlm_join_handlers); + if (!list_empty(&dlm_join_handlers)) + o2net_unregister_and_flush_handler_list(&dlm_join_handlers); } static int dlm_register_net_handlers(void)