Re: Review status (Re: [PATCH] LogFS take three)

Evgeniy Polyakov
2007-05-20T17:32:05Z

On Thu, May 17, 2007 at 07:10:19PM +0200, Jörn Engel (joern@lazybastard.org) wrote:
> On Thu, 17 May 2007 20:03:11 +0400, Evgeniy Polyakov wrote:
> >
> > Is logfs 32bit fs or 674bit, since although you use 64bit values for
> > offsets, area management and strange converstions like described below
> > from offset into segment number are performed in 32bit?
> > Is it enough for SSD for example to be 32bit only? Or if it is 64bit,
> > could you please explain logic behind area management?
>
> Ignoring bugs and signed return values for error handling, it is either
> 64bit or 32+32bit.
>
> Inode numbers and file positions are 64bit. Offsets are 64bit as well.
> In a couple of places, offsets are also 32+32bit. Basically the high
> bits contain the segment number, the lower bits the offset within a
> segment.

In that case segment size must be more than 32 bits, or below
transformation will not be correct? segsize is long, but should be u64 I
think.

static void fixup_from_wbuf(struct super_block *sb, struct logfs_area
*area, void *read, u64 ofs, size_t readlen)

u32 read_start = ofs & (super->s_segsize - 1);
u32 read_end = read_start + readlen;

And this can overflow, since readlen is size_t.
It is wbuf fixup, but I saw that somewhere else.
Although, according to your description, it should be 32bit, sum can be
more than 32 bit.

> If anyone can find similar bugs, the bounty is a beer or non-alcoholic
> beverage of choice. :)

Stop kiling your kidneys, your health and promote such antisocial style
of life, start drinking vodka instead.

> Jörn

--
Evgeniy Polyakov