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Date: Tue, 22 May 2018 03:20:00 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Subject: Re: set_fs(KERNEL_DS) vs iovec
Message-ID: <20180522102000.GA20067@infradead.org>
References: <8c7ac8af210606f2e4be4bfbb0b2506be53b60e3.camel@kernel.crashing.org>
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On Tue, May 22, 2018 at 03:08:35PM +1000, Benjamin Herrenschmidt wrote:
> Hence my question: Is is still acceptable these days to use
> set_fs(KERNEL_DS) for simple cases like this ?

Not at all.

> Or is it really
> deprecated and all new users should use the iovec's ?

Yes, please use iov_iter.  It should actually make your code simpler,
too.