Re: buffer/page cache aliasing? Re: 2.4 odd behaviour of ramdisk + cramfs

From: Remco van Mook
Date: Thu Nov 13 2003 - 12:03:56 EST


At 17:45 13-11-2003 +0100, bert hubert wrote:
On Thu, Nov 13, 2003 at 05:32:49PM +0100, Remco van Mook wrote:

> #! /bin/sh
> cat /flash/modules-2.4.21 > /dev/ram1
> mount -t cramfs -o ro /dev/ram1 /lib/modules
>
> Running it once causes the mount to fail with 'cramfs: wrong magic' -
> running it twice will make mount succeed on the second try.

Sounds like buffer/page cache aliasing perhaps? Does it work with other
filesystems?

I've just checked it with an ext2 filesystem - exactly the same thing happens.

Now, what's more interesting is that if I try again with a bigger filesystem
(3MB instead of 750KB) the problem only appears every now and again.

So it's probably got nothing to do with cramfs in particular, but more with the
size of the filesystem.

Remco

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