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 43328394EBD for ; Tue, 12 May 2026 14:22:37 +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=1778595757; cv=none; b=DtI0yuoINVRjXZpQZ5UooyBec33Peugh4j/1LajyAm4Gf4/jogjMzzcceTmXBw0PQhfe+RQLWt/76o2U12H/Vn+ata8EGUr31miJv3oYVjK/w9cy76o46zOc03HtXZ5o9ozrXcrmqI/B6mArupvaQy8FPOxWFVIAxbUIKxGBk3o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778595757; c=relaxed/simple; bh=JEYPKoiNHCYDJmPx6K9DAeVW+82CBJ062+2eEfs6DTk=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=K8QDCMds2743YhLae6HMTIdx+1SwZFd+Bm073IaIOtZhHao1Gov9uSRx3dygI2wQLu9MPANN80xR9YfEKCzAJ/jgef4YqsZ/povHVydvdQP5X9A/7Se6YQlK647PxA9TXsMPNJ9IbDHBzVS0kYlQ2+79ggghIF+kZklVVZBlsGw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fXAl6wny; 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="fXAl6wny" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CEDDCC2BCB0; Tue, 12 May 2026 14:22:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778595757; bh=JEYPKoiNHCYDJmPx6K9DAeVW+82CBJ062+2eEfs6DTk=; h=Subject:To:Cc:From:Date:From; b=fXAl6wny3IyaCGo+R6snFA1EjLm1piYLJ/W7Ixas/Dq78YiYlnUo4zm6Q8o5oH5Bo xssj2yyP8hiTvObsuxlq8Zk6YCw0n/9rxGmRWT/MEL0AReFbk5xbzPgg2nwU6gMYss pGzigJRM1163z4DHh/+KMRFm6dz9N3X3cb8TZqtA= Subject: FAILED: patch "[PATCH] f2fs: fix false alarm of lockdep on cp_global_sem lock" failed to apply to 6.6-stable tree To: chao@kernel.org,jaegeuk@kernel.org,shinichiro.kawasaki@wdc.com Cc: From: Date: Tue, 12 May 2026 16:22:39 +0200 Message-ID: <2026051239-tightly-tadpole-2db4@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 6.6-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-6.6.y git checkout FETCH_HEAD git cherry-pick -x 6a5e3de9c2bb0b691d16789a5d19e9276a09b308 # git commit -s git send-email --to '' --in-reply-to '2026051239-tightly-tadpole-2db4@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6a5e3de9c2bb0b691d16789a5d19e9276a09b308 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Fri, 6 Mar 2026 12:24:20 +0000 Subject: [PATCH] f2fs: fix false alarm of lockdep on cp_global_sem lock lockdep reported a potential deadlock: a) TCMU device removal context: - call del_gendisk() to get q->q_usage_counter - call start_flush_work() to get work_completion of wb->dwork b) f2fs writeback context: - in wb_workfn(), which holds work_completion of wb->dwork - call f2fs_balance_fs() to get sbi->gc_lock c) f2fs vfs_write context: - call f2fs_gc() to get sbi->gc_lock - call f2fs_write_checkpoint() to get sbi->cp_global_sem d) f2fs mount context: - call recover_fsync_data() to get sbi->cp_global_sem - call f2fs_check_and_fix_write_pointer() to call blkdev_report_zones() that goes down to blk_mq_alloc_request and get q->q_usage_counter Original callstack is in Closes tag. However, I think this is a false alarm due to before mount returns successfully (context d), we can not access file therein via vfs_write (context c). Let's introduce per-sb cp_global_sem_key, and assign the key for cp_global_sem, so that lockdep can recognize cp_global_sem from different super block correctly. A lot of work are done by Shin'ichiro Kawasaki, thanks a lot for the work. Fixes: c426d99127b1 ("f2fs: Check write pointer consistency of open zones") Cc: stable@kernel.org Reported-and-tested-by: Shin'ichiro Kawasaki Closes: https://lore.kernel.org/linux-f2fs-devel/20260218125237.3340441-1-shinichiro.kawasaki@wdc.com Signed-off-by: Shin'ichiro Kawasaki Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 39b97621456a..56c4af4b1737 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2042,6 +2042,9 @@ struct f2fs_sb_info { spinlock_t iostat_lat_lock; struct iostat_lat_info *iostat_io_lat; #endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lock_class_key cp_global_sem_key; +#endif }; /* Definitions to access f2fs_sb_info */ diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index f626e5ca089d..ae81af5a8d29 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -4964,6 +4964,11 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc) init_f2fs_rwsem_trace(&sbi->gc_lock, sbi, LOCK_NAME_GC_LOCK); mutex_init(&sbi->writepages); init_f2fs_rwsem_trace(&sbi->cp_global_sem, sbi, LOCK_NAME_CP_GLOBAL); +#ifdef CONFIG_DEBUG_LOCK_ALLOC + lockdep_register_key(&sbi->cp_global_sem_key); + lockdep_set_class(&sbi->cp_global_sem.internal_rwsem, + &sbi->cp_global_sem_key); +#endif init_f2fs_rwsem_trace(&sbi->node_write, sbi, LOCK_NAME_NODE_WRITE); init_f2fs_rwsem_trace(&sbi->node_change, sbi, LOCK_NAME_NODE_CHANGE); spin_lock_init(&sbi->stat_lock); @@ -5435,6 +5440,9 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc) free_sb_buf: kfree(raw_super); free_sbi: +#ifdef CONFIG_DEBUG_LOCK_ALLOC + lockdep_unregister_key(&sbi->cp_global_sem_key); +#endif kfree(sbi); sb->s_fs_info = NULL; @@ -5516,6 +5524,9 @@ static void kill_f2fs_super(struct super_block *sb) /* Release block devices last, after fscrypt_destroy_keyring(). */ if (sbi) { destroy_device_list(sbi); +#ifdef CONFIG_DEBUG_LOCK_ALLOC + lockdep_unregister_key(&sbi->cp_global_sem_key); +#endif kfree(sbi); sb->s_fs_info = NULL; }