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[34.69.28.131]) by smtp.googlemail.com with ESMTPSA id x64sm8529485ilk.47.2021.01.31.16.32.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 31 Jan 2021 16:32:26 -0800 (PST) From: Vinicius Tinti To: Andreas Dilger , Nathan Chancellor Cc: Theodore Ts'o , Nick Desaulniers , Vinicius Tinti , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: [PATCH v2] ext4: Enable code path when DX_DEBUG is set Date: Mon, 1 Feb 2021 00:31:25 +0000 Message-Id: <20210201003125.90257-1-viniciustinti@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org By enabling -Wunreachable-code-aggressive on Clang the following code paths are unreachable. This has been present since commit ac27a0ec112a ("[PATCH] ext4: initial copy of files from ext3") and fs/ext3 had it present at the beginning of git history. It has not been changed since. Clang warns: fs/ext4/namei.c:831:17: warning: code will never be executed [-Wunreachable-code] unsigned n = count - 1; ^~~~~ fs/ext4/namei.c:830:7: note: silence by adding parentheses to mark code as explicitly dead if (0) { // linear search cross check ^ /* DISABLES CODE */ ( ) Signed-off-by: Vinicius Tinti --- fs/ext4/namei.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index cf652ba3e74d..46ae6a4e4be5 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -827,20 +827,21 @@ dx_probe(struct ext4_filename *fname, struct inode *dir, p = m + 1; } - if (0) { // linear search cross check - unsigned n = count - 1; - at = entries; - while (n--) +#ifdef DX_DEBUG + // linear search cross check + unsigned n = count - 1; + at = entries; + while (n--) + { + dxtrace(printk(KERN_CONT ",")); + if (dx_get_hash(++at) > hash) { - dxtrace(printk(KERN_CONT ",")); - if (dx_get_hash(++at) > hash) - { - at--; - break; - } + at--; + break; } - ASSERT(at == p - 1); } + ASSERT(at == p - 1); +#endif at = p - 1; dxtrace(printk(KERN_CONT " %x->%u\n", -- 2.25.1