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 0AE90374E74 for ; Wed, 20 May 2026 11:17:35 +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=1779275857; cv=none; b=rmeS7KDIy77sfonngYfE7g3sTxAI0nPMI9J0plixvuWZdRebSATCeR7tzCNUCsREv0f/pWrCHFp2KaHjX3R3F0mwHBB4B5+LUp8MSMPJwd3tRWRBy10UbRn/s1RwAKQrspmcT2M4NCDK/UZ7mcEI3R8fC0ehB/cC4Qbs3A9kkWg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779275857; c=relaxed/simple; bh=SwICcjUIVp4nK/nxe+bRDzRSjU89i9JwCrRw9RBwREk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=o+xwzy6TzsgGp4cv7fzbDvyGumZQDCoWIdtT3uIl9hUlgpANdcfftbXIj3XXwv6mJPzjW8YVB4NKt9yZOxkTXOmkY8p+sRSKP9b4RkOV4hZFafHu0e1jjgCxnTT/hF1XXv0oc/iKi9bPIBfXkiiN6RlORT4iKVDLJoayBha+9hw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EOwdn8k3; 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="EOwdn8k3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 167281F000E9; Wed, 20 May 2026 11:17:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779275855; bh=KjS458LSYSa6vvqd02iPoZRNPsV/uZP7bKyI5eXQ3sE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=EOwdn8k3kkwq2vrDWHWgmS28i1AY1SOCt3MsY4UnBPb2d4yedEgsrtSM/uvFbm3iA yQzAeMiCzhKiuaCXo83lXR3S1fTwlojftnJpkMb+FX59oz/NkH0iQQTXXdGXUDVZ+p gsynDCSgBnIDJfnqEQgPva59pZiNKso4NFMYz9httjkLnJnpxWngHyQCbGUuCDehC5 v2V4gjMXNFm1wf4HFvt4JAvxd1V1aIyUFOx8hpmbwF06GFk7tqTfgO+tLJxooWVi47 rfa0q9x22Pxll1uVOsflZDvkG/EVbmJ0yOkCa+cbb8gSsQHbMYwJBVsZmIu38EiPC0 drGU3tmxU5KFA== From: Sasha Levin To: stable@vger.kernel.org Cc: Chao Yu , stable@kernel.org, Shin'ichiro Kawasaki , Jaegeuk Kim , Sasha Levin Subject: [PATCH 6.6.y] f2fs: fix false alarm of lockdep on cp_global_sem lock Date: Wed, 20 May 2026 07:17:33 -0400 Message-ID: <20260520111733.3419315-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026051239-tightly-tadpole-2db4@gregkh> References: <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-Transfer-Encoding: 8bit From: Chao Yu [ Upstream commit 6a5e3de9c2bb0b691d16789a5d19e9276a09b308 ] 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 [ re-anchored lockdep_register_key after init_f2fs_rwsem and placed lockdep_unregister_key before kfree(sbi) in f2fs_put_super instead of kill_f2fs_super ] Signed-off-by: Sasha Levin --- fs/f2fs/f2fs.h | 3 +++ fs/f2fs/super.c | 11 +++++++++++ 2 files changed, 14 insertions(+) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index fb35f78e60bb3..50847fd7e5504 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1824,6 +1824,9 @@ 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 7614d93bd67fb..c018d548e1634 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1694,6 +1694,9 @@ static void f2fs_put_super(struct super_block *sb) kvfree(sbi->write_io[i]); #if IS_ENABLED(CONFIG_UNICODE) utf8_unload(sb->s_encoding); +#endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC + lockdep_unregister_key(&sbi->cp_global_sem_key); #endif kfree(sbi); } @@ -4380,6 +4383,11 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) init_f2fs_rwsem(&sbi->gc_lock); mutex_init(&sbi->writepages); init_f2fs_rwsem(&sbi->cp_global_sem); +#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(&sbi->node_write); init_f2fs_rwsem(&sbi->node_change); spin_lock_init(&sbi->stat_lock); @@ -4838,6 +4846,9 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) free_sbi: if (sbi->s_chksum_driver) crypto_free_shash(sbi->s_chksum_driver); +#ifdef CONFIG_DEBUG_LOCK_ALLOC + lockdep_unregister_key(&sbi->cp_global_sem_key); +#endif kfree(sbi); /* give only one another chance */ -- 2.53.0