Re: [PATCH v2 4/4] splice: fix updating sd->pos wrongly

[Changli Gao]

On Sat, May 29, 2010 at 10:09 PM, Jamie Lokier <jamie@xxxxxxxxxxxxx> wrote:
>
> Not true if the "file" is /dev/mem or /dev/kmem. ÂThe starting offset
> can be negative, so can end at zero.
>
> It's an obscure case and I don't know if you can sendfile from
> /dev/{,k}mem anyway :-) but illustrates why sd->pos != 0 is dubious.
>

So the safe way is checking if splice_read() updates pos or not, isn't it?

if (sd->pos != prev_pos)
    sd->pos = prev_pos + ret;


-- 
Regardsï
Changli Gao(xiaosuo@xxxxxxxxx)
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