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 8772441AAC for ; Thu, 16 Oct 2025 12:35:58 +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=1760618158; cv=none; b=kSoXL//FmEuG+SaBlNhrH3Z5g9agrEtZGglDV6muAhWXXlIhriTQUO5zza2P5jYfjvNw5pVwY+9WkyT0SgJ4kXwqaNc6SqS41sydcEiOXxPr0/JNhnMifMG+6KeLnLIKS4pcB1a4jmFwdq6AYY560GMM+UIkjbjg1Y49g6KeLk8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760618158; c=relaxed/simple; bh=qFojuEhGzDmjqa7kWDiHTF4Sq/vVtyJWJFkigVaj6nE=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=SrbBWCVSyzLQ1KwdyRq8bkemPs7pbf9QHIgA0ujcc1PEyNHcYkOyEYB6/7SzAYPJ6Jy7gcNMZ2V2zAvr+Cca7ByybnlzP/6fj2cQWyuBtLXBDBZIQhceyf3HRLAXhaoJ3fBrWqRE71eeScs+tdwflYYcoYasEgOfhZb/7z/sk7A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tt3NPLCM; 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="tt3NPLCM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13EC9C4CEF1; Thu, 16 Oct 2025 12:35:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760618158; bh=qFojuEhGzDmjqa7kWDiHTF4Sq/vVtyJWJFkigVaj6nE=; h=Subject:To:Cc:From:Date:From; b=tt3NPLCMc9NSSD36kMI9hTstKmKe0eVXDDXqxi2PR1ZOy4J99KTLGpvRk+W91gH1R MpgD6TsQ8W1fJM+D90Guk6RDDoNwfK9HdbM4QT6u44wrGYnn1hea0O2VYnkOdK6F9W iUmj25fcMm51jOQwRjqCHO47i08GmmxLMIW/OPJ8= Subject: FAILED: patch "[PATCH] fs: quota: create dedicated workqueue for quota_release_work" failed to apply to 6.1-stable tree To: shashank.ap@samsung.com,jack@suse.cz Cc: From: Date: Thu, 16 Oct 2025 14:35:51 +0200 Message-ID: <2025101651-arrive-frail-3c0f@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 6.1-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-6.1.y git checkout FETCH_HEAD git cherry-pick -x 72b7ceca857f38a8ca7c5629feffc63769638974 # git commit -s git send-email --to '' --in-reply-to '2025101651-arrive-frail-3c0f@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 72b7ceca857f38a8ca7c5629feffc63769638974 Mon Sep 17 00:00:00 2001 From: Shashank A P Date: Mon, 1 Sep 2025 14:59:00 +0530 Subject: [PATCH] fs: quota: create dedicated workqueue for quota_release_work 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 diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index df4a9b348769..6c4a6ee1fa2b 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -162,6 +162,9 @@ static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; /* 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); @@ -881,7 +884,7 @@ 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); @@ -3041,6 +3044,11 @@ 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);