Date: Sat, 20 Feb 1999 01:19:44 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: jdp@polstra.com (John Polstra) Cc: tlambert@primenet.com, hackers@FreeBSD.ORG Subject: Re: UIDs greater than 65535? Message-ID: <199902200119.SAA17512@usr02.primenet.com> In-Reply-To: <XFMail.990219163650.jdp@polstra.com> from "John Polstra" at Feb 19, 99 04:36:50 pm
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> >> Can anybody think of a reason why UIDs > 65535 wouldn't work under > >> FreeBSD? They seem to work, and I can't find any reason why they > >> shouldn't. Even the NFS protocol (though not necessarily all NFS > >> servers) seems to be able to accomodate 4-byte UIDs. > > > > 65536 in an unsigned short is -1 is "nobody". > > Actually, nobody is 65534 on FreeBSD systems. But anyway, I've only > found a couple of places where UIDs are stored in unsigned shorts: I meant 65535, but yeah, -2 is right. I can't remember back to Ultrix, but I know -1 was *something*; ah, got it. It's who root becomes if you don't allow root access via NFS. > * In the API to the System V message functions, in <sys/ipc.h>. > * In Linux programs run under emulation. > > There are also some limits in archive files, because UIDs are encoded > as (*gag*) 5-digit decimal numbers. > > These problems are all avoidable in the application I have in mind. See the quota code. The thing uses a sparse file, and spazzes out > 65535. Not that it has spare space for the time_t going to 64 bits anyway. 8-(. I have a quota stacking layer that resolves both the Year 2038 issues and the uid_t/gid_t issues, includes version stamping the file, and has a format converter (quotacheck -c 1), but it won't run in an unhacked FreeBSD kernel because of my local VFS changes to support stacking layers actually working, and cleaner vnode based kernel file I/O. I think a stacking layer is the way to go; I can put quotas on my ext2fs and UMSDOS (stack over VFAT, using Udo Walter's attribute file: -linux--.--- [bletch] or mine: -umsdos-.--- [yea, symmetric, not OS tagged]) FS's. Woo hoo. 8-). Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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