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From:   Daniel Rosenberg <drosen@google.com>
Date:   Mon, 10 Feb 2020 15:11:13 -0800
Message-ID: <CA+PiJmTYbEA-hgrKwtp0jZXqsfYrzgogOZ0Pt=gTCtqhBfnqFA@mail.gmail.com>
Subject: Re: [PATCH v7 2/8] fs: Add standard casefolding support
To:     Al Viro <viro@zeniv.linux.org.uk>
Cc:     "Theodore Ts'o" <tytso@mit.edu>, linux-ext4@vger.kernel.org,
        Jaegeuk Kim <jaegeuk@kernel.org>, Chao Yu <chao@kernel.org>,
        linux-f2fs-devel@lists.sourceforge.net,
        Eric Biggers <ebiggers@kernel.org>,
        linux-fscrypt@vger.kernel.org, Richard Weinberger <richard@nod.at>,
        linux-mtd@lists.infradead.org,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        Jonathan Corbet <corbet@lwn.net>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        Gabriel Krisman Bertazi <krisman@collabora.com>,
        kernel-team@android.com
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On Fri, Feb 7, 2020 at 6:12 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Fri, Feb 07, 2020 at 05:35:46PM -0800, Daniel Rosenberg wrote:
>
>
> Again, is that safe in case when the contents of the string str points to
> keeps changing under you?

I'm not sure what you mean. I thought it was safe to use the str and
len passed into d_compare. Even if it gets changed under RCU
conditions I thought there was some code to ensure that the name/len
pair passed in is consistent, and any other inconsistencies would get
caught by d_seq later. Are there unsafe code paths that can follow?