From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CE2AEB64DD for ; Thu, 20 Jul 2023 18:22:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229563AbjGTSWK (ORCPT ); Thu, 20 Jul 2023 14:22:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229457AbjGTSWK (ORCPT ); Thu, 20 Jul 2023 14:22:10 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47562E6F for ; Thu, 20 Jul 2023 11:22:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D034F61B7D for ; Thu, 20 Jul 2023 18:22:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6A64C433C8; Thu, 20 Jul 2023 18:22:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689877327; bh=02TTll4zLc6+Z13xIgnTGNPNXf7KXTfF8EarFsvYefU=; h=Subject:To:Cc:From:Date:From; b=p4nxB/lTzYd4iJVErY8+2kmc5C8Xl6VIGJv6RXMlXVLMEHR0yMw+RkosiHZ+RX0qf tJpEKK4otO/IHhzTrwx9EYq2yLm1HOk9+ueyBMHi+jwtEBfKAXCprIq48sQBQKFe6y iVNSo/85gfYQY/ZXmpG7Ul0OyqbLEAaLaYQAVghU= Subject: FAILED: patch "[PATCH] f2fs: don't reset unchangable mount option in f2fs_remount()" failed to apply to 6.1-stable tree To: chao@kernel.org, jaegeuk@kernel.org, stable@vger.kernel.org Cc: From: Date: Thu, 20 Jul 2023 20:22:04 +0200 Message-ID: <2023072004-unashamed-coping-b642@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 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 458c15dfbce62c35fefd9ca637b20a051309c9f1 # git commit -s git send-email --to '' --in-reply-to '2023072004-unashamed-coping-b642@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: 458c15dfbce6 ("f2fs: don't reset unchangable mount option in f2fs_remount()") 12607c1ba763 ("f2fs: specify extent cache for read explicitly") 967eaad1fed5 ("f2fs: fix to set flush_merge opt and show noflush_merge") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 458c15dfbce62c35fefd9ca637b20a051309c9f1 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Tue, 23 May 2023 11:58:22 +0800 Subject: [PATCH] f2fs: don't reset unchangable mount option in f2fs_remount() syzbot reports a bug as below: general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:__lock_acquire+0x69/0x2000 kernel/locking/lockdep.c:4942 Call Trace: lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691 __raw_write_lock include/linux/rwlock_api_smp.h:209 [inline] _raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300 __drop_extent_tree+0x3ac/0x660 fs/f2fs/extent_cache.c:1100 f2fs_drop_extent_tree+0x17/0x30 fs/f2fs/extent_cache.c:1116 f2fs_insert_range+0x2d5/0x3c0 fs/f2fs/file.c:1664 f2fs_fallocate+0x4e4/0x6d0 fs/f2fs/file.c:1838 vfs_fallocate+0x54b/0x6b0 fs/open.c:324 ksys_fallocate fs/open.c:347 [inline] __do_sys_fallocate fs/open.c:355 [inline] __se_sys_fallocate fs/open.c:353 [inline] __x64_sys_fallocate+0xbd/0x100 fs/open.c:353 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The root cause is race condition as below: - since it tries to remount rw filesystem, so that do_remount won't call sb_prepare_remount_readonly to block fallocate, there may be race condition in between remount and fallocate. - in f2fs_remount(), default_options() will reset mount option to default one, and then update it based on result of parse_options(), so there is a hole which race condition can happen. Thread A Thread B - f2fs_fill_super - parse_options - clear_opt(READ_EXTENT_CACHE) - f2fs_remount - default_options - set_opt(READ_EXTENT_CACHE) - f2fs_fallocate - f2fs_insert_range - f2fs_drop_extent_tree - __drop_extent_tree - __may_extent_tree - test_opt(READ_EXTENT_CACHE) return true - write_lock(&et->lock) access NULL pointer - parse_options - clear_opt(READ_EXTENT_CACHE) Cc: Reported-by: syzbot+d015b6c2fbb5c383bf08@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/20230522124203.3838360-1-chao@kernel.org Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 8eb17cc73941..6e770f82d39f 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2086,9 +2086,22 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root) return 0; } -static void default_options(struct f2fs_sb_info *sbi) +static void default_options(struct f2fs_sb_info *sbi, bool remount) { /* init some FS parameters */ + if (!remount) { + set_opt(sbi, READ_EXTENT_CACHE); + clear_opt(sbi, DISABLE_CHECKPOINT); + + if (f2fs_hw_support_discard(sbi) || f2fs_hw_should_discard(sbi)) + set_opt(sbi, DISCARD); + + if (f2fs_sb_has_blkzoned(sbi)) + F2FS_OPTION(sbi).discard_unit = DISCARD_UNIT_SECTION; + else + F2FS_OPTION(sbi).discard_unit = DISCARD_UNIT_BLOCK; + } + if (f2fs_sb_has_readonly(sbi)) F2FS_OPTION(sbi).active_logs = NR_CURSEG_RO_TYPE; else @@ -2118,23 +2131,16 @@ static void default_options(struct f2fs_sb_info *sbi) set_opt(sbi, INLINE_XATTR); set_opt(sbi, INLINE_DATA); set_opt(sbi, INLINE_DENTRY); - set_opt(sbi, READ_EXTENT_CACHE); set_opt(sbi, NOHEAP); - clear_opt(sbi, DISABLE_CHECKPOINT); set_opt(sbi, MERGE_CHECKPOINT); F2FS_OPTION(sbi).unusable_cap = 0; sbi->sb->s_flags |= SB_LAZYTIME; if (!f2fs_is_readonly(sbi)) set_opt(sbi, FLUSH_MERGE); - if (f2fs_hw_support_discard(sbi) || f2fs_hw_should_discard(sbi)) - set_opt(sbi, DISCARD); - if (f2fs_sb_has_blkzoned(sbi)) { + if (f2fs_sb_has_blkzoned(sbi)) F2FS_OPTION(sbi).fs_mode = FS_MODE_LFS; - F2FS_OPTION(sbi).discard_unit = DISCARD_UNIT_SECTION; - } else { + else F2FS_OPTION(sbi).fs_mode = FS_MODE_ADAPTIVE; - F2FS_OPTION(sbi).discard_unit = DISCARD_UNIT_BLOCK; - } #ifdef CONFIG_F2FS_FS_XATTR set_opt(sbi, XATTR_USER); @@ -2306,7 +2312,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data) clear_sbi_flag(sbi, SBI_NEED_SB_WRITE); } - default_options(sbi); + default_options(sbi, true); /* parse mount options */ err = parse_options(sb, data, true); @@ -4346,7 +4352,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) sbi->s_chksum_seed = f2fs_chksum(sbi, ~0, raw_super->uuid, sizeof(raw_super->uuid)); - default_options(sbi); + default_options(sbi, false); /* parse mount options */ options = kstrdup((const char *)data, GFP_KERNEL); if (data && !options) {