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Date:   Wed, 26 Dec 2018 06:58:50 +0000
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Alexey Dobriyan <adobriyan@gmail.com>
Cc:     Kangjie Lu <kjlu@umn.edu>, pakki001@umn.edu,
        Andrew Morton <akpm@linux-foundation.org>,
        Davidlohr Bueso <dbueso@suse.de>,
        David Howells <dhowells@redhat.com>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] fs: proc: check status of register_filesystem
Message-ID: <20181226065850.GG2217@ZenIV.linux.org.uk>
References: <20181226030642.72757-1-kjlu@umn.edu>
 <20181226061856.GA2122@avx2>
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On Wed, Dec 26, 2018 at 09:18:56AM +0300, Alexey Dobriyan wrote:
> On Tue, Dec 25, 2018 at 09:06:40PM -0600, Kangjie Lu wrote:
> > register_filesystem() could fail. The fix issues an error message if it
> > fails.
> 
> > -	register_filesystem(&proc_fs_type);
> > +	if (register_filesystem(&proc_fs_type))
> > +		pr_err("failed to register the filesystem.\n");
> 
> No, register_filesystem() should do it.

Folks, check when would it fail.  If we have something called "proc"
already registered by the time when proc_root_init() runs... might
as well have been a panic().