From: "Theodore Ts'o" <tytso@mit.edu>
To: Li zeming <zeming@nfschina.com>
Cc: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ext4: extents: Remove unnecessary ‘NULL’ values from path
Date: Mon, 1 Apr 2024 23:55:02 -0400 [thread overview]
Message-ID: <20240402035502.GC1189142@mit.edu> (raw)
In-Reply-To: <20240402024140.28456-1-zeming@nfschina.com>
On Tue, Apr 02, 2024 at 10:41:40AM +0800, Li zeming wrote:
> path is assigned first, so it does not need to initialize the
> assignment.
That's technically true, but the compiler is perfectly capable of
optimizing it out. So it's harmless, and removing it does make the
code a bit more fragile, since it needs to be set so that the cleanup
code doesn't accidentally dereference an uninitialized pointer:
out:
up_read(&ei->i_data_sem);
ext4_free_ext_path(path);
return ret;
So if later on, we add code which does a "goto out" on an error,
before path gets initialized, that would be bad. So removing the
"unnecessary" set has no upside, and it has a potential disadvantage.
- Ted
prev parent reply other threads:[~2024-04-02 3:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-02 2:41 [PATCH] ext4: extents: Remove unnecessary ‘NULL’ values from path Li zeming
2024-04-02 3:55 ` Theodore Ts'o [this message]
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