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From:   Miklos Szeredi <miklos@szeredi.hu>
Date:   Wed, 4 Mar 2020 17:10:58 +0100
Message-ID: <CAJfpeguyyC=E51gJ3EkQjLsqjZ8Mt35Eu7f9cQtBJaTFEcxoRg@mail.gmail.com>
Subject: Re: [PATCH 10/17] fsinfo: Allow mount information to be queried [ver #17]
To:     David Howells <dhowells@redhat.com>
Cc:     Al Viro <viro@zeniv.linux.org.uk>, Ian Kent <raven@themaw.net>,
        Miklos Szeredi <mszeredi@redhat.com>,
        Christian Brauner <christian@brauner.io>,
        Jann Horn <jannh@google.com>,
        "Darrick J. Wong" <darrick.wong@oracle.com>,
        Linux API <linux-api@vger.kernel.org>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
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On Fri, Feb 21, 2020 at 7:03 PM David Howells <dhowells@redhat.com> wrote:
 +
> +/*
> + * Return information about the submounts relative to path.
> + */
> +int fsinfo_generic_mount_children(struct path *path, struct fsinfo_context *ctx)
> +{
> +       struct fsinfo_mount_child record;
> +       struct mount *m, *child;
> +
> +       if (!path->mnt)
> +               return -ENODATA;
> +
> +       m = real_mount(path->mnt);
> +
> +       rcu_read_lock();
> +       list_for_each_entry_rcu(child, &m->mnt_mounts, mnt_child) {

mnt_mounts is not using _rcu primitives, so why is this rcu safe?

Thanks,
Miklos