From: Vinicius Tinti <viniciustinti@gmail.com>
To: Andreas Dilger <adilger.kernel@dilger.ca>,
Nathan Chancellor <natechancellor@gmail.com>
Cc: Theodore Ts'o <tytso@mit.edu>,
Nick Desaulniers <ndesaulniers@google.com>,
Vinicius Tinti <viniciustinti@gmail.com>,
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 [thread overview]
Message-ID: <20210201003125.90257-1-viniciustinti@gmail.com> (raw)
In-Reply-To: <AAB32610-D238-4137-96DE-33655AAAB545@dilger.ca>
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 <viniciustinti@gmail.com>
---
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
next prev parent reply other threads:[~2021-02-01 0:33 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-29 18:58 [PATCH] ext4: Remove unreachable code Vinicius Tinti
2021-01-30 1:35 ` Nathan Chancellor
2021-01-30 6:42 ` Andreas Dilger
2021-02-01 0:31 ` Vinicius Tinti [this message]
2021-02-01 0:48 ` [PATCH v2] ext4: Enable code path when DX_DEBUG is set Nathan Chancellor
2021-02-01 12:49 ` Christoph Hellwig
2021-02-01 16:15 ` Vinicius Tinti
2021-02-01 17:13 ` Theodore Ts'o
2021-02-01 18:41 ` Vinicius Tinti
2021-02-01 20:45 ` Andreas Dilger
2021-02-01 21:09 ` Theodore Ts'o
2021-02-01 21:16 ` Nick Desaulniers
2021-02-01 21:38 ` Theodore Ts'o
2021-02-01 21:41 ` Nick Desaulniers
2021-02-01 22:05 ` Vinicius Tinti
2021-02-01 22:48 ` Theodore Ts'o
2021-02-01 23:09 ` Nick Desaulniers
2021-02-02 8:05 ` Christoph Hellwig
2021-02-02 16:28 ` [PATCH v3] " Vinicius Tinti
2021-02-03 5:39 ` Theodore Ts'o
2021-02-03 9:51 ` Vinicius Tinti
2021-02-01 16:58 ` [PATCH v2] " Theodore Ts'o
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