Re: [dm-devel] multipath disk size

[Arsene Gschwind <arsene gschwind unibas ch>]

I've found something strange, 2 declaration of SERIAL_SIZE with 
different sizes
libmultipath/structs.h:#define SERIAL_SIZE              17
path_priority/pp_balance_units/pp_balance_units.c:#define SERIAL_SIZE 255

In my case the first buffer size is to small because pp->serial has a 
size of 17 chars and when you look at my output it has 40 chars.
By setting libmultipath/structs.h:#define SERIAL_SIZE    to 255 it works 
for me and the returned volume size is correct.
I'm not sure if this is the right solution, it would be great if someone 
could verify that issue.

Thanks a lot for your work
Arsène

URZ- AG wrote:

> Christophe Varoqui wrote:
>
> > >
> > Thanks for this report.
> >
> > I can't reproduce this here.
> >
> > I'm afraid I'll have to ask you to try and refine your report though.
> > Use a debugger to track [m]pp->size changes, or try adding debugging 
> > output in the key code areas : add_map_with_path(), coalesce_paths(), 
> > ...
> >
> > Regards,
> > cvaroqui
> Hello Christophe,
>
> I'm not a C Guru but i think i have been able to track it down.
> It seems that when discovering the device for paths after the 
> get_serial (discovery.c) function the size has changed.
> I've entered two debug entries in  scsi_ioctl_pathinfo() which prints 
> out  pp->size, one before get_serial call and one after and the size 
> has changed when the second print its value. So far I've seen, this 
> function should not change anything to the size, but it seems to write 
> to that pointer, could it be that this function writes out of a buffer 
> size?
> I'm not comfortable with the debugger so I have not been able to debug 
> that in deep.
> It would be great if  you could give me some more instructions on how 
> to analyze/debug it .
>
> Regards,
> Arsène
>
> --
> dm-devel mailing list
> dm-devel redhat com
> https://www.redhat.com/mailman/listinfo/dm-devel


--
***********************************************************
Gschwind Arsene			
Universitaet Rechenzentrum (URZ)
Klingelbergstrasse 70
CH-4056 Basel
SWITZERLAND

Languages : F/E/D
WWW:  <http://www.urz.unibas.ch>
Mail: <Arsene DOT Gschwind AT unibas DOT ch>
************************************************************