lkml.org 
[lkml]   [2002]   [May]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: atari partitioning problem?
On Mon, 13 May 2002, Kenneth D. Merry wrote:

> [ Al Viro CCed, since from the changelog for 2.4.11, it looks like he may
> have submitted the patch in question. ]
>
> I was looking through the atari partitioning code (fs/partitions/atari.c)
> in 2.4.18 (from what I can see in 2.4.19-pre8, it hasn't changed) and I
> noticed something (starting at about line 144) that may be a problem:
>
> for (; pi < &rs->icdpart[8] && minor < m_lim; minor++, p
> i++) {
> /* accept only GEM,BGM,RAW,LNX,SWP partitions */
> if (!((pi->flg & 1) && OK_id(pi->id)))
> continue;
> part_fmt = 2;
> add_gd_partition (hd, minor,
> be32_to_cpu(pi->st),
> be32_to_cpu(pi->siz));
> }
> printk(" >");
>
> This code changed in 2.4.11, and was previously:
>
> for (; pi < &rs->icdpart[8] && minor < m_lim; minor++, pi++)
> {
> /* accept only GEM,BGM,RAW,LNX,SWP partitions */
> if (pi->flg & 1 &&
> (memcmp (pi->id, "GEM", 3) == 0 ||
> memcmp (pi->id, "BGM", 3) == 0 ||
> memcmp (pi->id, "LNX", 3) == 0 ||
> memcmp (pi->id, "SWP", 3) == 0 ||
> memcmp (pi->id, "RAW", 3) == 0) )
> {
> part_fmt = 2;
> add_gd_partition (hd, minor, be32_to_cpu(pi->st),
> be32_to_cpu(pi->siz));
> }
> }
> printk(" >");
>
> Note that the test was reversed, but not fully. You want only active
> partitions of the specified types to be added, but with the code as it is
> now, only partitions that are active and *not* of the correct type will get
> added.

No, the change is correct.

Note that the ! in the first snippet is in front of the whole expression,
and it's pretty obvious that the reversed test for (a && b) is !(a && b).

The latter is equivalent to (!a || !b), which seems to be what you're
thinking, but you didn't get it right and put !(a || !b) which is wrong.

--Kai


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:26    [W:0.028 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site