From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2DAAF32E15D; Fri, 17 Oct 2025 15:20:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760714407; cv=none; b=oDyVQIBpj88gEQNu0gHpoZT1MbZboMVVOj4P5qrHzYJFhFq1CILwJAhDTiRVfP37DU4fme2fHi8SYlmv74Teh8r3qAwi6+T7SEUuWvzK+EzdCu7EP2agXdZJ/wmDCI5jl3YpIlO1PTQEQH/vZpE7iDJCzykgkfIYP06dYGJNhdY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760714407; c=relaxed/simple; bh=vMs9PYzS+aiHnquPePHMMkPtTPmzSpGH9a74U1NcWvg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pn+v/RJntuC/cBhkSEcV24SxLQ/g9CaxGWPqcK01T7+p7fab+jfb2RYLaeHFOWGhy9iDOAP8SqSMjJCbiRIcsMXErlB7oUvrAmFtktZAyahuq06tSTdwv6YdLaD4CNSB+J9aw6aJ31Gl8nM1uQp/tWKnJhHESwGZ4ctJg3UXn8w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=v+jU5Y5l; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="v+jU5Y5l" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB46AC4CEE7; Fri, 17 Oct 2025 15:20:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760714407; bh=vMs9PYzS+aiHnquPePHMMkPtTPmzSpGH9a74U1NcWvg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=v+jU5Y5lha4q/0KQ7BvjPrbsQTjWYRKu2lG6c/oQqMBcpk3F8vKPYlSEOo19pvIET OT2oC6cW0fLYc/VvQ6B+WnA4ugeLphFy0x9yH+QDvazvbz3fl9QGXKETYFhj4d1JtN KemxyIroVbhsTLJ8h+8ELFPkfYe5CVsdIJfsZSOU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shashank A P , Jan Kara Subject: [PATCH 6.12 133/277] fs: quota: create dedicated workqueue for quota_release_work Date: Fri, 17 Oct 2025 16:52:20 +0200 Message-ID: <20251017145151.981394004@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251017145147.138822285@linuxfoundation.org> References: <20251017145147.138822285@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shashank A P commit 72b7ceca857f38a8ca7c5629feffc63769638974 upstream. There is a kernel panic due to WARN_ONCE when panic_on_warn is set. This issue occurs when writeback is triggered due to sync call for an opened file(ie, writeback reason is WB_REASON_SYNC). When f2fs balance is needed at sync path, flush for quota_release_work is triggered. By default quota_release_work is queued to "events_unbound" queue which does not have WQ_MEM_RECLAIM flag. During f2fs balance "writeback" workqueue tries to flush quota_release_work causing kernel panic due to MEM_RECLAIM flag mismatch errors. This patch creates dedicated workqueue with WQ_MEM_RECLAIM flag for work quota_release_work. ------------[ cut here ]------------ WARNING: CPU: 4 PID: 14867 at kernel/workqueue.c:3721 check_flush_dependency+0x13c/0x148 Call trace: check_flush_dependency+0x13c/0x148 __flush_work+0xd0/0x398 flush_delayed_work+0x44/0x5c dquot_writeback_dquots+0x54/0x318 f2fs_do_quota_sync+0xb8/0x1a8 f2fs_write_checkpoint+0x3cc/0x99c f2fs_gc+0x190/0x750 f2fs_balance_fs+0x110/0x168 f2fs_write_single_data_page+0x474/0x7dc f2fs_write_data_pages+0x7d0/0xd0c do_writepages+0xe0/0x2f4 __writeback_single_inode+0x44/0x4ac writeback_sb_inodes+0x30c/0x538 wb_writeback+0xf4/0x440 wb_workfn+0x128/0x5d4 process_scheduled_works+0x1c4/0x45c worker_thread+0x32c/0x3e8 kthread+0x11c/0x1b0 ret_from_fork+0x10/0x20 Kernel panic - not syncing: kernel: panic_on_warn set ... Fixes: ac6f420291b3 ("quota: flush quota_release_work upon quota writeback") CC: stable@vger.kernel.org Signed-off-by: Shashank A P Link: https://patch.msgid.link/20250901092905.2115-1-shashank.ap@samsung.com Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/quota/dquot.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -163,6 +163,9 @@ static struct quota_module_name module_n /* SLAB cache for dquot structures */ static struct kmem_cache *dquot_cachep; +/* workqueue for work quota_release_work*/ +static struct workqueue_struct *quota_unbound_wq; + void register_quota_format(struct quota_format_type *fmt) { spin_lock(&dq_list_lock); @@ -882,7 +885,7 @@ void dqput(struct dquot *dquot) put_releasing_dquots(dquot); atomic_dec(&dquot->dq_count); spin_unlock(&dq_list_lock); - queue_delayed_work(system_unbound_wq, "a_release_work, 1); + queue_delayed_work(quota_unbound_wq, "a_release_work, 1); } EXPORT_SYMBOL(dqput); @@ -3042,6 +3045,11 @@ static int __init dquot_init(void) shrinker_register(dqcache_shrinker); + quota_unbound_wq = alloc_workqueue("quota_events_unbound", + WQ_UNBOUND | WQ_MEM_RECLAIM, WQ_MAX_ACTIVE); + if (!quota_unbound_wq) + panic("Cannot create quota_unbound_wq\n"); + return 0; } fs_initcall(dquot_init);