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 32BAC2C3278; Wed, 17 Sep 2025 12:39:39 +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=1758112779; cv=none; b=f/NbqrV+BCZsf1PS/5lO9o5dfO+qw/kEVvNtq0puNvVCKbxvXjf3jYaGc0DxxXJ27KuFm64UFleRL5XzgjFBXTNCD0o20JB9DXUuKs3TcCV+5zkkTjzA6xdXUx3n2TI2iMpC+YMhpo/RNbt7FOU9KPUmrZ/hCjc6XUH/BvgxDCA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758112779; c=relaxed/simple; bh=DSzPAd3e0MM8rTXEAtRk8NUIcJyo8zXdoEG9XdKpNgM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=g/v7vRE8aflxtJvl+KV2HHFf5WOXO4ctWxLmRchNpwsBkRamN5xWQM4Om3SwjfdfklMdyMtfu7cF4INtsR5ptD2i9FIYbGuMm46msGRCXmdtl4/wZbD0vZmnyNrcyML/L0/jZOqirtkDdTsdu6Mxm1/FAUoutjTkQZ4vLq4s1ko= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=G0Eh8U4b; 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="G0Eh8U4b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4A88C4CEF0; Wed, 17 Sep 2025 12:39:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1758112779; bh=DSzPAd3e0MM8rTXEAtRk8NUIcJyo8zXdoEG9XdKpNgM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G0Eh8U4bQF634gtZ2mP7oewmn7XTptvuMr53yWeojj4QClCzY1X0tImJ7KmzwZbsG ugegG8/XJXCqLv9sRbF+BrE3/iyHl+Vw2yIQ7i9S1MNm0CdOQjXRS46y1b3GqW85jL BL0GbPQ1scVfta+lV00k1D1DJH+6I4D3CQabFo6k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Qu Wenruo , Boris Burkov , David Sterba Subject: [PATCH 6.16 057/189] btrfs: fix squota compressed stats leak Date: Wed, 17 Sep 2025 14:32:47 +0200 Message-ID: <20250917123353.257502559@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250917123351.839989757@linuxfoundation.org> References: <20250917123351.839989757@linuxfoundation.org> User-Agent: quilt/0.68 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 6.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Boris Burkov commit de134cb54c3a67644ff95b1c9bffe545e752c912 upstream. The following workload on a squota enabled fs: btrfs subvol create mnt/subvol # ensure subvol extents get accounted sync btrfs qgroup create 1/1 mnt btrfs qgroup assign mnt/subvol 1/1 mnt btrfs qgroup delete mnt/subvol # make the cleaner thread run btrfs filesystem sync mnt sleep 1 btrfs filesystem sync mnt btrfs qgroup destroy 1/1 mnt will fail with EBUSY. The reason is that 1/1 does the quick accounting when we assign subvol to it, gaining its exclusive usage as excl and excl_cmpr. But then when we delete subvol, the decrement happens via record_squota_delta() which does not update excl_cmpr, as squotas does not make any distinction between compressed and normal extents. Thus, we increment excl_cmpr but never decrement it, and are unable to delete 1/1. The two possible fixes are to make squota always mirror excl and excl_cmpr or to make the fast accounting separately track the plain and cmpr numbers. The latter felt cleaner to me so that is what I opted for. Fixes: 1e0e9d5771c3 ("btrfs: add helper for recording simple quota deltas") CC: stable@vger.kernel.org # 6.12+ Reviewed-by: Qu Wenruo Signed-off-by: Boris Burkov Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/qgroup.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1483,6 +1483,7 @@ static int __qgroup_excl_accounting(stru struct btrfs_qgroup *qgroup; LIST_HEAD(qgroup_list); u64 num_bytes = src->excl; + u64 num_bytes_cmpr = src->excl_cmpr; int ret = 0; qgroup = find_qgroup_rb(fs_info, ref_root); @@ -1494,11 +1495,12 @@ static int __qgroup_excl_accounting(stru struct btrfs_qgroup_list *glist; qgroup->rfer += sign * num_bytes; - qgroup->rfer_cmpr += sign * num_bytes; + qgroup->rfer_cmpr += sign * num_bytes_cmpr; WARN_ON(sign < 0 && qgroup->excl < num_bytes); + WARN_ON(sign < 0 && qgroup->excl_cmpr < num_bytes_cmpr); qgroup->excl += sign * num_bytes; - qgroup->excl_cmpr += sign * num_bytes; + qgroup->excl_cmpr += sign * num_bytes_cmpr; if (sign > 0) qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);