[Lustre-discuss] Lustre 1.8.0.50 + Xen + kernel 2.6.22.17

[Andreas Dilger]

On Apr 20, 2009  20:23 +0200, Lukas Hejtmanek wrote:
> I'm using 1.8.0.50 lustre server + clients. The server is running native
> 2.6.22.19 kernel, it has 1 mds and 3 OSDs (all at one server).

FYI, 1.8.0.50 appears to be the b1_8 development branch.  While we are
happy to have bug reports on this, you shouldn't expect it to be a
heavily tested release.

> I have an application that reads TIFF images stored on the lustre fs. The
> libtiff uses mmap on tiffs to read. Unfortunately, I got Bus Errors (SIGBUS)
> from libtiff.
> 
> The core looks like this:
> #1  0x00002b7d5ff825a2 in DumpModeDecode (tif=0x58cdd0, buf=0xf7f7f7f5f5f5f6f6
> <Address 0xf7f7f7f5f5f5f6f6 out of bounds>, cc=76800, s=2016)
>     at tif_dumpmode.c:85

This looks like the buffer being passed to the kernel is not aligned
properly.   The message is fairly clear:

	buf=0xf7f7f7f5f5f5f6f6
	<Address 0xf7f7f7f5f5f5f6f6 out of bounds>

For mmap IO this should be aligned to a PAGE_SIZE boundary, normally
a multiple of 4096 bytes.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.