Date: Fri, 29 Aug 1997 11:33:55 +1200 From: physmsa AT cantua DOT canterbury DOT ac DOT nz (Mr M S Aitchison) Subject: Linux fast support with OpenDOS extensions? To: opendos-developer AT caldera DOT com, opendos AT delorie DOT com Message-id: <199708282333.LAA01942@cantua.canterbury.ac.nz> Precedence: bulk I've been looking at the linux code for accessing (v)fat dos partitions; until long filenames (and the extra time information that came at the same time), it was relatively easy to modify Linux to support permissions flags, groups ID's,m and user ID's (and, sort of, passwords) in a way that is compatible with OpenDOS (well, really Multiuser DRDOS). The problem now is that the password field could contain just about anything, depending on the extra time information Win95 stores there. It is easy enough to use the creation (not last write) date field to test if the password & permissions fields should be used as DRDOS has used them for years. Non-zero creation dates imply either Win95 has written this directory entry or somebody is using Group ID's (not used in single-user DRDOS, Novell DOS, OpenDOS, except there was a system call that a user program could have used I seem to remember). Possibly using one of the fields straight after the file attributes would be a better choice. What I'd like to see is: (a) Linux being able to store some information (like permissions, userid) in fat partitions, (b) OpenDOS able to use partitions/diskettes written by Win95 without it thinking files are password protected when they aren't, (c) OpenDOS and Linux working better together, at least as file attributes are concerned. I appreciate that the ultimate solution is a new filesystem for OpenDOS, but we should be able to make better use of the present situation where a mixture of any two or more of Linux, OpenDOS/DRDOS, Win95 and maybe OS/2 are involved. What do others think is the best way to "adjust" OpenDOS's pasword protection system (something I'd hate to lose) to avoid conflicts with Win95?? Also, is anybody interested in helping modify the Linux fat support software, e.g. by creating an alternative to vfat that is "universal" in adapting to either legacy PCDOS (special fields ignored), or DRDOS/OpenDOS (UID, GID, MDRDOS-like permissions and some mapping of passwords), or Win95 (creation date, last access date, etc). ------------------------------------------------------------------------------- Mark Aitchison, Physics & Astronomy \_ Phone : +64 3 3642-947 a.h. 3371-225 University of Canterbury, (/' Callsign: ZL3TQE -------------------------------------------------------------------------------