A note about HAVE_MMAP

John E. Malmberg wb8tyw at qsl.net
Wed Sep 29 12:56:57 GMT 2004


In article <CF0913E9C3D53D4E94DE47FDE25C633D05049090 at hermes.cofiroute.com>,
COLLOT Jean-Yves <jean-yves.collot at cofiroute.fr> writes:

> Since Dave Jones provided a new, VMS-specific TDB set of routines, defining
> HAVE_MMAP or not has no more impact on Samba/VMS.

What about the file transfer section of SAMBA where if HAVE_MMAP is set, and
the smb.conf setting for it is enabled, it sometimes bypasses the stm_read()
and stm_write(), and vms_lseek() routines completely and does random direct
read/writes to the file on the host.

This works correctly only on the STREAM and FIXed format files.  For VFC files
when the MMAP bypasses those routines, file corruption will appear to be
present on reads, and writes can corrupt the file.

It took me a while to find that in the SAMBA 2.0.6 release.

There still has been no feedback to this mailing list if disabling mmap in
the smb.conf file had any effect on the observed corruption of VFC files.

-John
wb8tyw at qsl.network
Personal Opinion Only



More information about the samba-vms mailing list