Re: mmap() on cdrom files fails in 2.6.9-rc2-mmX

[Bill Davidsen <davidsen@tmr.com>]

Jean Delvare wrote:
> Hi all,
> 
> (Please CC me on reply, I am not subscribed to the LKML.)
> 
> I think I found a bug in 2.6.9-rc2-mm4. It doesn't seem to be able to
> mmap() files located on cdroms. Same problem with -mm3 and -mm1.
> 2.6.9-rc2 works fine. I reproduced it on two completely different
> systems, so I guess it isn't device dependant.
> 
> I tried to get mmap() to fail on other files with similar properties
> (different owner, read only) but it won't. The problem seems to affect
> only files located on cdroms.
> 
> I also tried on a loop device-mounted cdrom image, in case the problem
> was related to the iso9660 filesystem. The problem wouldn't show. It
> seems to fail only on real cdroms.
> 
> I searched the broken-out directory but wouldn't find any candidate to
> backout.

Is your mmap length a multiple of 2k? If not please resize and try 
again. There is some less traveled code when physical sector size is not 
512 bytes.

Yes, this is a wild guess, but it's easy to test if you have the kernel 
built.

-- 
    -bill davidsen (davidsen@tmr.com)
"The secret to procrastination is to put things off until the
  last possible moment - but no longer"  -me