Re: [9fans] SYSTOR 2009---The Israeli Experimental Systems Conference
which homie in the hood is going to represent? yo ak
Re: [9fans] SYSTOR 2009---The Israeli Experimental Systems Conference
I wonder how much flack I would get from Israeli passport control for the stamps in my passport. :) On Thu, Jan 22, 2009 at 1:26 PM, Akshat Kumar aku...@mail.nanosouffle.net wrote: which homie in the hood is going to represent? yo ak
Re: [9fans] SYSTOR 2009---The Israeli Experimental Systems Conference
I don't know but that's a good group of people on the committee. I expect they'd be open to more than the usual how I got linux to be power aware type papers ... ron
Re: [9fans] SYSTOR 2009---The Israeli Experimental Systems
I wonder how much flack I would get from Israeli passport control for the stamps in my passport. :) What makes you think you'll be allowed back into those countries after visiting Israel? :-) ++L
Re: [9fans] SYSTOR 2009---The Israeli Experimental Systems
If I remember, when you visit Israel, they put an additional paper in your passport. This paper is removed when you leave the country. Then ... your passport do not have any stamp of Israel ... and you will not have problems visit other countries. Saludos, kix. I wonder how much flack I would get from Israeli passport control for the stamps in my passport. :) What makes you think you'll be allowed back into those countries after visiting Israel? :-) ++L -- Rodolfo García AKA kix http://www.kix.es/ EA4ERH (@IN80ER)
[9fans] file creation time
Does Plan 9 really not provide for file creation?
typedef
struct Dir {
/* system-modified data */
ushort type; /* server type */
uintdev;/* server subtype */
/* file data */
Qid qid;/* unique id from server */
ulong mode; /* permissions */
ulong atime; /* last read time */
ulong mtime; /* last write time */
vlong length; /* file length */
char*name; /* last element of path */
char*uid; /* owner name */
char*gid; /* group name */
char*muid; /* last modifier name */
} Dir;
It's been a long time, have I asked this already?
++L
Re: [9fans] file creation time
use the dump, luke. ☺ If there was an easy, foolproof way to scan the dump by filename, I presume I could search for the earliest instance and consider that the time of creation. Not entirely viable, is it? I do wonder why this field was sacrificed in the file system(s) and 9P*? Or am I dreaming and the time of creation is just a figment of my imagination? ++L PS: I'm sure your reply was in jest. So, largely, is my query.
Re: [9fans] file creation time
On Thu, Jan 22, 2009 at 10:50 AM, lu...@proxima.alt.za wrote: use the dump, luke. ☺ If there was an easy, foolproof way to scan the dump by filename, I presume I could search for the earliest instance and consider that the time of creation. Not entirely viable, is it? history(1) http://plan9.bell-labs.com/magic/man2html?man=historysect=1
Re: [9fans] file creation time
On Thu Jan 22 12:54:14 EST 2009, lu...@proxima.alt.za wrote: use the dump, luke. ☺ If there was an easy, foolproof way to scan the dump by filename, I presume I could search for the earliest instance and consider that the time of creation. Not entirely viable, is it? it's hard to give a good answer, since i don't know what the goal is. I do wonder why this field was sacrificed in the file system(s) and 9P*? Or am I dreaming and the time of creation is just a figment of my imagination? of course on a worm filesystem, you could say that each time a file is modified after it has made it to the worm, it becomes a brand new file. though the qid.path doesn't track this view. the create time would then differ from the mtime by as most the time between dumps. andrey suggests history(1) history doesn't give creation times. it gives the last mtime before the first dump of the file. the file could be deleted and recreated many times and you'd never know. (unless you were to peek at the qid.path.) but then again, history might be exactly what you're looking for. it usually is for me. - erik
Re: [9fans] file creation time
useful or not, traditional unix ctime never gave the creation time anyway - it gave inode modification time, which isn't the same thing at all: it's updated when you do a chmod. Well, that is understandable, if contrary to the principle of least astonishment. Thank you for that gem, I would never have picked it up without having it pointed out to me. ++L
Re: [9fans] file creation time
On Thu Jan 22 14:33:05 EST 2009, 9f...@hamnavoe.com wrote: will the real creation time please stand up. October 23, 4004 BC. so when we add 8-byte times to 9p2010 Tstat and Wstat, we can add a constant ctime field of -188466825600? or should that just be hardcoded? - erik
Re: [9fans] file creation time
I would never have picked it up without having it pointed out to me. to be fair, in one of the system include files it was commented as ino.h: time_t di_ctime; /* time created */ but it was only a comment. stat(2) was more accurate.
[9fans] fun question
I ask this every time I hit this piece of code, I think. But what the heck: if(seed - 0) seed = seed + m_31; what's wrong with this code? ron
Re: [9fans] fun question
On Thu Jan 22 15:55:09 EST 2009, rminn...@gmail.com wrote: I ask this every time I hit this piece of code, I think. But what the heck: if(seed - 0) seed = seed + m_31; what's wrong with this code? supposing the code does what it is supposed to on some machines, i would guess that this could be a problem for sign-magnitude or one's-comp. machines, since 0 and -0 are different. if that's the case, one would guess that the object is to clear sign bit and -0 is the failure case. then again, that's a very wild guess and one would assume that sign = -sign would be better. -0 is a strange construction and the spacing is misleading. it's interesting that atoi(2) and the differ on - 0. - erik
Re: [9fans] fun question
On Thu, Jan 22, 2009 at 12:53 PM, ron minnich rminn...@gmail.com wrote: I ask this every time I hit this piece of code, I think. But what the heck: if(seed - 0) seed = seed + m_31; what's wrong with this code? - is a unary operator. russ
Re: [9fans] fun question
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Jan 22, 2009, at 5:01 PM, Russ Cox wrote: - is a unary operator. okay, what does it do? (unless you meant - in C++) -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.8 (Darwin) iEYEARECAAYFAkl47zYACgkQuv7AVNQDs+wr7ACgi7QtQv4m4TweJlyzLFSHUs41 ZCYAnR6CqXQp69/g99pUkI0W789SRxXF =s97M -END PGP SIGNATURE-
Re: [9fans] fun question
- is a unary operator. okay, what does it do? (unless you meant - in C++) it receives from a channel. russ
Re: [9fans] fun question
On Thu Jan 22 17:55:55 EST 2009, r...@swtch.com wrote:
- is a unary operator.
okay, what does it do? (unless you meant - in C++)
it receives from a channel.
i assumed that ron was talking about c.
in c, - 0 tokenizes as , -, and 0.
- is taken to be a unary operator on 0.
even gcc does this correctly:
; cat x.c
#include u.h
#include libc.h
void
x(int seed)
{
int m_31;
m_31 = 131;
if(seed - 0)
seed = seed + m_31;
print(seed %d\n, seed);
}
void
main(void)
{
x(-5);
exits();
}
eot; 9c x.c
; 9l x.o
; ./a.out
seed -2147483648
- erik
Re: [9fans] fun question
Erik got it. That code originally was written for a 1s complement machine, the CDC 7200 I believe. I get a kick out of it every time I see something and remember machines with + and - 0 :-) ron
[9fans] srv funny?
I don't undrestand what's going on here: term% 9fs sources post... term% ls -l /n/sources d-rwxrwxr-x M 38 9grid 9grid 0 Oct 20 2005 /n/sources/9grid ... term% cpu -h phlogiston.acm.jhu.edu cpu% mount -n /mnt/term/srv/sources /n/sources !Adding key: dom=outside.plan9.bell-labs.com proto=p9sk1 user[nwf]: Why is the terminal able to use /srv/sources to mount /n/sources but the cpu server isn't able to use exportfs's access to /srv/sources to do the same? If it helps, I'm running on 9vx for term% and a real Plan 9 system for cpu%. My terminal's 9fs is passing -n to srv, too, just to be clear: case sources srv -nq tcp!sources.cs.bell-labs.com sources /n/sources Thanks. --nwf; pgp69qqWJnpUX.pgp Description: PGP signature
Re: [9fans] srv funny?
cpu% mount -n /mnt/term/srv/sources /n/sources !Adding key: dom=outside.plan9.bell-labs.com proto=p9sk1 user[nwf]: Why is the terminal able to use /srv/sources to mount /n/sources but the cpu server isn't able to use exportfs's access to /srv/sources to do the same? mount -n doesn't ask for keys, despite what this transcript looks like. If you run ps on both systems (in other windows), I bet you will find that the /factotum -g process asking for the key is running on your terminal, not the cpu server. When the cpu server mounts /mnt/term/srv/sources, it sends Tread and Twrite requests for /srv/sources to the exportfs serving /mnt/term. That's a 9P conversation inside a 9P conversation, i.e. the payloads of the Tread and Rwrite messages are themselves 9P messages. Clumsy fact #1: After an fd has been mounted, ordinary read and write system calls are not allowed on it: the kernel owns the 9P connection now. Not doing this would require serious effort in the kernel, since user-level reads and writes would interfere with the kernel's reads and writes. The obvious implementation of Tread/Twrite in exportfs-- call the read and write system calls on the underlying fd-- can't work for exporting /srv/sources, because the kernel owns the 9P connection. Instead, exportfs mounts /srv/sources onto /mnt/exportfs/1 and then invokes itself recursively to serve /mnt/exportfs/1 onto a freshly created pipe. Then it translates the Tread/Twrite messages for /srv/sources into read and write system calls on that pipe. Clumsy fact #2: 9P is really intended for two use cases: either the server never requires authentication (in which case it replies to Tauth with an Rerror), or it always does (in which case it replies to Tauth with Rauth and you authenticate on that fid). Sources is an attempt to have it both ways: if you don't offer to authenticate (don't bother sending a Tauth), sources won't ask you to, but if you do offer, you have to follow through. In contrast, when you offer to authenticate to, say, the plumber, it just waves you off. In hindsight, a better way to do the dual-mode sources would have been to announce on two different ports, one with authentication and one without. But what's done is done. So... When cpu's exportfs mounts /srv/sources in order to start serving /mnt/term/srv/sources, it uses amount(2) (just like mount does without -n), which offers to authenticate and then causes the prompt. The -n flag to srv only affects the mount that srv does, not future mounts. The easiest thing to do is pretend this didn't happen and just mount sources directly from phlogiston. If that machine doesn't have network connectivity to sources, you could bind /mnt/term/net /net; 9fs sources Russ
Re: [9fans] fun question
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Jan 22, 2009, at 6:01 PM, erik quanstrom wrote: i assumed that ron was talking about c. Yeah, that's what I thought. Sorry, Russ. -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.8 (Darwin) iEYEARECAAYFAkl5E1IACgkQuv7AVNQDs+xctgCggzbkwZ8EpuuEPu7e5kgItuC5 vDgAnisvoB6CWTOrPaXQ04jqyRL2kuJV =Yw+A -END PGP SIGNATURE-
[9fans] anyone tried fossil on p9p?
Has anyone gotten fossil (with or without venti) working on p9p, or tried and failed? I've been playing around with a variety of 9vx configurations and want to try booting it off a p9p-hosted fossil (on the same physical box). That's the next project.
