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 58F0C3F54D0 for ; Tue, 19 May 2026 12:41:59 +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=1779194519; cv=none; b=NltrAS1tYQp6JMFJfNYDlGpvoWjQWgcsKpEmdJzIP/9/J2+dRcX5YDZJ6x5SUrDUt7WUDepFv0fmkE8N7baFeCFavVaIlI6aFrOSjRHJKlWCHbIrT6UhRm8mjbWcVYflncp7Tmle9XbUH8a/GSceen4UhOlca/ySqjFTIenjHng= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779194519; c=relaxed/simple; bh=xThAgdEOhi6zVUTTDyU6CRW0010CIKDiyBG/aEqSiY8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Huy8Qn1Y1Np1+Pu0ck8iRzf7mEFk7eGXzf47LlA1o2HdFOIyy2pcxqIplL708nMk1tRtALo1CT71vSpwNkRSay5k6+uDOug6HkASmgbOb+YFGWFiNTeUBsqTgi+f7FlOrM3I0vN3/+L1Ajh3nAcQOUHeQt7GsfduKkvk7dZmwuQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M/K0Hsd3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="M/K0Hsd3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49507C2BCB3; Tue, 19 May 2026 12:41:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779194519; bh=xThAgdEOhi6zVUTTDyU6CRW0010CIKDiyBG/aEqSiY8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=M/K0Hsd3BJh4NF/RZORWw6jnJ05KfXGqt4mH5k7RpNvtrty/bzl3lfV4t1t90p82v +QYiYSkjfQNcRX3fGRhmrSyaKkefuGXgVuj9U2Wvn5h3hKxZe15trnqNzxaTugeKDD Z77cQCfgNdWee6TojOyguTwh6WDPIjUh5xVVjaZ52K5dw1so16753maa+wdoS/u/r6 pQVEm07SfqwCSPg5M1y/eM7rNo4f5eNBUiDThdfXtUbfkkC3o+rHSSWwP+4eaegS1/ 6MfDTH28d3RkKptuzyC4PxphcxzFwNy47HZlUs0Nj4duAlstmtDPu/FkdR38AEmxy2 b0JzytMeZq8Rg== From: Sasha Levin To: stable@vger.kernel.org Cc: Chao Yu , stable@kernel.org, Shin'ichiro Kawasaki , Jaegeuk Kim , Sasha Levin Subject: [PATCH 6.12.y] f2fs: fix false alarm of lockdep on cp_global_sem lock Date: Tue, 19 May 2026 08:41:56 -0400 Message-ID: <20260519124156.2447314-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026051239-booting-appendix-92a8@gregkh> References: <2026051239-booting-appendix-92a8@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 [ adapted context to use `init_f2fs_rwsem()` instead of the not-yet-backported `init_f2fs_rwsem_trace()` macro ] 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 ab0d9ed02092c..b094fdaf318dd 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1858,6 +1858,9 @@ 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 f25a259f37f12..1bce35d6f4e25 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -4490,6 +4490,11 @@ 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); @@ -4963,6 +4968,9 @@ 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); sb->s_fs_info = NULL; @@ -5015,6 +5023,9 @@ 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; } -- 2.53.0