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Date:   Wed, 19 Sep 2018 10:26:26 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     David Howells <dhowells@redhat.com>, viro@zeniv.linux.org.uk,
        torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [PATCH 14/33] vfs: Implement a filesystem superblock
 creation/configuration context [ver #11]
Message-ID: <20180919012626.GA482@jagdpanzerIV>
References: <20180911220743.GA13208@roeck-us.net>
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 <153313714181.13253.304098108512966976.stgit@warthog.procyon.org.uk>
 <27113.1536702746@warthog.procyon.org.uk>
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 <20180911235403.GA10107@roeck-us.net>
 <20180918090722.GA463@jagdpanzerIV>
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On (09/19/18 10:12), Sergey Senozhatsky wrote:
> On (09/18/18 07:06), Guenter Roeck wrote:
> > > So the check either better be
> > > 
> > > 	if (fc->ops && fc->ops->reconfigure)
> > > 
> > 
> > Since there are multiple instances of fs_context where fc->ops isn't set,
> > this check would be needed wherever fc->ops is dereferenced.
> 
> Right. If fc is always guaranteed to be properly zeroed-out. This is
> true for kzalloc-ed fc's, but not necessarily so in any other case.

What I mean was something like this

	void foo(void)
	{
		struct fs_context fc;

		fc.purpose   = ...;
		fc.fs_type   = ...;
		fc.root      = ...;
		fc.sb_flags  = ...;

		reconfigure_super(&fc);
	}

	-ss