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From:   Amir Goldstein <amir73il@gmail.com>
Date:   Wed, 30 Jun 2021 15:51:11 +0300
Message-ID: <CAOQ4uxg063mwwdLnM7vooJSB38HvPF5jkSck6MunEL+K4oHArA@mail.gmail.com>
Subject: Re: [PATCH v3 07/15] fsnotify: pass arguments of fsnotify() in struct fsnotify_event_info
To:     Dan Carpenter <dan.carpenter@oracle.com>
Cc:     kbuild@lists.01.org,
        Gabriel Krisman Bertazi <krisman@collabora.com>,
        kbuild test robot <lkp@intel.com>, kbuild-all@lists.01.org,
        "Darrick J. Wong" <djwong@kernel.org>,
        Theodore Tso <tytso@mit.edu>,
        Dave Chinner <david@fromorbit.com>, Jan Kara <jack@suse.com>,
        David Howells <dhowells@redhat.com>,
        Khazhismel Kumykov <khazhy@google.com>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Ext4 <linux-ext4@vger.kernel.org>, kernel@collabora.com
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On Wed, Jun 30, 2021 at 1:49 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> I think my bug report was not clear...  :/  The code looks like this:
>
>         sb = inode->i_sb;
>
>         if (inode) ...
>
> The NULL check cannot be false because if "inode" is NULL we would have
> already crashed when we dereference it on the line before.
>
> In this case, based on last years discussion, the "inode" pointer can't
> be NULL.  The debate is only whether the unnecessary NULL checks help
> readability or hurt readability.
>

Right. Sorry, I forgot.

Anyway, patch 11/15 of the same series changes this code to:

 sb = event_info->sb ?: inode->i_sb;

So inode can and will be NULL coming from the caller of
fsnotify_sb_error(sb, NULL).

I think that should make smach happy?
You can try to run it after patch 11/15 of this series.

Thanks,
Amir.