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 24F7326AC5; Sat, 12 Sep 2026 15:59:15 +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=1789228756; cv=none; b=Y3oF9HKJaDFoCV3+y4xdNQpnW4rR0WJfPzSlHR08MUsZjvU6ewhW+2DCMV82mNMocEBAluFjmqn6+oHOE2fjPYk7Lxpy/+s9Yh0SnOo2IUbj0v+kadWGpgX295zkGzIBNGmvJn80ZvBHsXwAKiChxKcSXJ5IN3wuGBLVM1HTqLE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789228756; c=relaxed/simple; bh=ar9tIgOdFeWuAGwNuCnavUDQZOr9B8W450WGx8irqHc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BVDCEAlU2uSNd3Y6x1Jn4u0ZlSPaLUWeHSGfRf9Rqjm2hDgipCfE0We7uSDhf4dbGZJGX4jbYIdQqu76W+g4Xx666cbmO5unY3zmVqkH8Dck8jqWvHV4MG9hE9nx5FjzwnqoJkXhw78YvSB5GS1ImwNNhIjeA9T9qYlp3DroKbU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0pHzpVI+; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0pHzpVI+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EBCD71F000FF; Sat, 12 Sep 2026 15:59:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789228755; bh=Y7gxKmYPURORacGhBspRb0Gh3ShQDbnlgMupt29ae/k=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=0pHzpVI+L1q8T0Cu3CcvkQjWxRnys9pFHvrBUtuk5pM+2CD0uRUeAKH8ACQ5tmoQa cBOTdYq37IJTymw7f4QanU2Z+zEw+/ezvfSQQYO0AsOajgwLCtQRvvL5KimDxA9U/X 5RJeAuRoKHGei7ZoiESKv5yBxCorcz/hf7j+46uI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Baokun Li , Zhang Yi , Jan Kara , Theodore Tso , Sasha Levin Subject: [PATCH 6.1 0449/1191] ext4: move ext4_percpu_param_init() before ext4_mb_init() Date: Sat, 12 Sep 2026 08:52:57 +0200 Message-ID: <20260912065558.316787842@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065548.086904252@linuxfoundation.org> References: <20260912065548.086904252@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baokun Li [ Upstream commit 270564513489d98b721a1e4a10017978d5213bff ] When running `kvm-xfstests -c ext4/1k -C 1 generic/383` with the `DOUBLE_CHECK` macro defined, the following panic is triggered: ================================================================== EXT4-fs error (device vdc): ext4_validate_block_bitmap:423: comm mount: bg 0: bad block bitmap checksum BUG: unable to handle page fault for address: ff110000fa2cc000 PGD 3e01067 P4D 3e02067 PUD 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 2386 Comm: mount Tainted: G W 6.18.0-gba65a4e7120a-dirty #1152 PREEMPT(none) RIP: 0010:percpu_counter_add_batch+0x13/0xa0 Call Trace: ext4_mark_group_bitmap_corrupted+0xcb/0xe0 ext4_validate_block_bitmap+0x2a1/0x2f0 ext4_read_block_bitmap+0x33/0x50 mb_group_bb_bitmap_alloc+0x33/0x80 ext4_mb_add_groupinfo+0x190/0x250 ext4_mb_init_backend+0x87/0x290 ext4_mb_init+0x456/0x640 __ext4_fill_super+0x1072/0x1680 ext4_fill_super+0xd3/0x280 get_tree_bdev_flags+0x132/0x1d0 vfs_get_tree+0x29/0xd0 vfs_cmd_create+0x59/0xe0 __do_sys_fsconfig+0x4f6/0x6b0 do_syscall_64+0x50/0x1f0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ================================================================== This issue can be reproduced using the following commands: mkfs.ext4 -F -q -b 1024 /dev/sda 5G tune2fs -O quota,project /dev/sda mount /dev/sda /tmp/test With DOUBLE_CHECK defined, mb_group_bb_bitmap_alloc() reads and validates the block bitmap. When the validation fails, ext4_mark_group_bitmap_corrupted() attempts to update sbi->s_freeclusters_counter. However, this percpu_counter has not been initialized yet at this point, which leads to the panic described above. Fix this by moving the execution of ext4_percpu_param_init() to occur before ext4_mb_init(), ensuring the per-CPU counters are initialized before they are used. Signed-off-by: Baokun Li Reviewed-by: Zhang Yi Reviewed-by: Jan Kara Link: https://patch.msgid.link/20251209133116.731350-1-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/super.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 44b8c0dc9a41f..f2a569868e416 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5515,6 +5515,10 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) clear_opt2(sb, MB_OPTIMIZE_SCAN); } + err = ext4_percpu_param_init(sbi); + if (err) + goto failed_mount5; + err = ext4_mb_init(sb); if (err) { ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)", @@ -5530,10 +5534,6 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) sbi->s_journal->j_commit_callback = ext4_journal_commit_callback; - err = ext4_percpu_param_init(sbi); - if (err) - goto failed_mount6; - if (ext4_has_feature_flex_bg(sb)) if (!ext4_fill_flex_info(sb)) { ext4_msg(sb, KERN_ERR, @@ -5616,8 +5616,8 @@ failed_mount9: __maybe_unused failed_mount6: ext4_mb_release(sb); ext4_flex_groups_free(sbi); - ext4_percpu_param_destroy(sbi); failed_mount5: + ext4_percpu_param_destroy(sbi); ext4_ext_release(sb); ext4_release_system_zone(sb); failed_mount4a: -- 2.53.0