From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f43.google.com (mail-wr1-f43.google.com [209.85.221.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A4BF9272813 for ; Fri, 15 Aug 2025 09:13:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.43 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755249201; cv=none; b=kv3ouT7mwv1ZlEl+SWwCDBbwPPoZR9SAPDx3XnxoAwQaojdYnR7AIwEQEvUdPHRY5l+uooPVsHPVCWloiHnuWxymtNg6p88R9B/ZtiGrFRoqhTfLuRBEIAlFky93jAgKYPDYsGN5NMqhyOjj3DelNnXZtdahLM1Kp1OxsHlU7a8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755249201; c=relaxed/simple; bh=R1ChGoOiLWXPCnytpCVLCvDMw2jJbP5bOxcuNmV/5o8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=f7cycphtUjIyJGPZk1v2T/ldcFZAevFSi8jiiRt+OmVLtN9zZCrTcjy6L3StVfdftKKDNyXdtu23y9XN21Daf3YDOk+c60ybI7og7SXT41Bj5t/zw7DqEvKdAW9DihrfGAAuu5fJRwbkvKV+ooBx2matPzz0RAq4jjXJwhkCwkQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=EO/xVUPx; arc=none smtp.client-ip=209.85.221.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="EO/xVUPx" Received: by mail-wr1-f43.google.com with SMTP id ffacd0b85a97d-3b9a342e8ffso1269496f8f.0 for ; Fri, 15 Aug 2025 02:13:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1755249198; x=1755853998; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=ftw2ZfoUFvGBlklurn4IZdlca9Rx+oE47CzR8v2kWZw=; b=EO/xVUPxggom3ayaFdfVrZpkOazUjTyNXa2yhkMMxifPBOJIEl/VR4zzWrtrT+QNpu /GoAYtFDWSGcV4ll9if1xnyiIPb28EYTWysB6s/hwBfGaeMpoY+p1u7MGi+Ua2DTLxe7 hdXXhB2k+bzTsO/2UKjDThtj0zfdFmfr5deIhgjOt3z9AGOoeSXSYx08mwyeUmrp5WR4 DSkdxOEOYRTKlxQOjP/YY5ieJOw6I9sijO4xnnXEfpXYVAMRFMAQHXOmaIiohvEPArud DBGku106JC2PaUk7Bvwkewj1Gg3Us4hvCmwaYiRaTA41zNHrTWvJPlOCNoU0YKy3b0IU AKkA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755249198; x=1755853998; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ftw2ZfoUFvGBlklurn4IZdlca9Rx+oE47CzR8v2kWZw=; b=Z8ZWheqtYftPjS0fWEkFIOmSGzwIcjMGmlnCnhP1PKNpmLiimWgnhTOu6DoMZR0kuU oyXB7SQRvOXx30PxUTJ2a9QTQ2AQayN2blwTJDwUmmpPyTREhA7bdjNKtHr8zxYYS346 KvgVpdvmtIXZ+Ze5ju55TXq+2CaKl709qK0g3fqEJlHN5utKl1P0+C75zwVkhN7Ljc83 n5R/297FlOv0VlOXs6ZwpFvC74u6H0/EXJ/9gQFmvIeJc75v+vQlaPQsmtnPB/KIAHgh qiPgF7v0BFqgOKXZiFuq2X7/bOhkXUCcgC4kAtSqjh6OkKozKlVPt4mndf/vAkc+wfIN ohtA== X-Forwarded-Encrypted: i=1; AJvYcCWw9iBTalR8jejFW4BxvyixIgboXjiG6LxZWRBS9+FDY5umYt54trJOLJys5O+ygsKrIRQf0oneNtg7qg==@vger.kernel.org X-Gm-Message-State: AOJu0YxQHWFsicJWVbBKgS7t2q+JlZ9YJovmXBcBqvYY4mAQnFtDpJpq vZzhdS204cdjfZ9jY0q+GlFlvW56GCuu4UhuahtB2sCUfTvYq0Qk1yiJXxIsPxWy9wY= X-Gm-Gg: ASbGncvIBLBKRMQ9ka2Yd+ucZrMIa6CURKIAveQdzMsckMvUrJzGXFQ8qz/Mn9Qd557 p8udaC4z0jH/dmerHqxwsTl6kWgK/+uHcgirp/vxAjJqYd+wYxl94Z4kqKX1E+r0/auShG4gGSs ZDqoB0Q6zg2l61gcMrmpMmjvfQgXYJxEO94NUA6kAI9Vv3OnQ1s4pinIJ/gw5B3kFEw6qEUhoKh +kZsG7GNXlJlBaI12JANVOzNOjAID41eOcFNFl4bfAZJVn1u/a3oGCSeyDrcGTFif6iE5ll8UC6 Z+/PdQ/2D7H9vus7jinntHhIMWeWnEAl/U3sWEvzs8EfDsMSukWYy2ilT9thB4MgRZvMNS8SXfI U688eIkKr6j3PVeVv9YwmFfiY14Ppla3XK4baq8Tytp8= X-Google-Smtp-Source: AGHT+IGeNwN1NyLOt3iH637ptOqB9Y2vA35yxNTjFi6nt+WndRakdYXgdd6cR4AP+i+PrRRlGnyzyg== X-Received: by 2002:a5d:64cd:0:b0:3a4:f7dd:6fad with SMTP id ffacd0b85a97d-3bb4c5b7fb0mr1380255f8f.14.1755249197741; Fri, 15 Aug 2025 02:13:17 -0700 (PDT) Received: from localhost ([196.207.164.177]) by smtp.gmail.com with UTF8SMTPSA id ffacd0b85a97d-3bb656dbec5sm1203508f8f.31.2025.08.15.02.13.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 Aug 2025 02:13:17 -0700 (PDT) Date: Fri, 15 Aug 2025 12:13:13 +0300 From: Dan Carpenter To: Filipe Manana Cc: Filipe Manana , linux-btrfs@vger.kernel.org Subject: Re: [bug report] btrfs: abort transaction in the process_one_buffer() log tree walk callback Message-ID: References: Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Aug 15, 2025 at 09:28:34AM +0100, Filipe Manana wrote: > On Fri, Aug 15, 2025 at 7:50 AM Dan Carpenter wrote: > > > > Hello Filipe Manana, > > > > This is a semi-automatic email about new static checker warnings. > > > > Commit f6f79221b128 ("btrfs: abort transaction in the > > process_one_buffer() log tree walk callback") from Jul 16, 2025, > > leads to the following Smatch complaint: > > > > fs/btrfs/tree-log.c:377 process_one_buffer() warn: variable dereferenced before check 'trans' (see line 375) > > fs/btrfs/tree-log.c:388 process_one_buffer() warn: variable dereferenced before check 'trans' (see line 375) > > > > fs/btrfs/tree-log.c > > 374 if (wc->pin) { > > 375 ret = btrfs_pin_extent_for_log_replay(trans, eb); > > ^^^^^ > > The patch adds a dereference > > False alarm. This already happened before that patch, we didn't check > if wc->trans was NULL before calling > btrfs_pin_extent_for_log_replay(), and that's fine because if wc->pin > is true then trans is not NULL. > To be honest, the deleting the NULL check is the most common way to fix a "pointless NULL check after a dereference" warning... regards, dan carpenter