Diffs to 4.3BSD dump to dump live file systems

[Dave Curry]

I'm posting this here since this is where the original discussion
started, and because it's short.  No lectures about net.sources
from the news police, please.  Sorry it's not a follow up to the
original discussion, buf for some reason Pnews completely choked
on things ("inews: you didn't really want to post THAT!", whatever
that means).

----------

These are the diffs to 4.3BSD dump in order to allow safer dumping of 
live file systems. We originally made the mods to 4.2BSD dump, so you 
should be able to use that if you don't have 4.3BSD yet.  Beware that
the line numbers may differ though.

The code causes dump to ignore any inode which has been changed or 
modified during the dump. This will occasionally cause restore to 
print "resync restore" messages, however I have never seen restore 
actually choke on anything. 

We have been using this code for over a year with no ill effects.  As
always you should try to do dumps when there is as little activity on
the file system as possible.  We do our partials just after midnight
every morning.  Our fulls however run from two to three hours a piece,
and we do them on Saturday and Sunday mornings when there are plenty
of users on the system.  We've had no trouble with this, so the code
seems to be pretty effective.

--Dave Curry
Purdue University
Engineering Computer Network
davy at intrepid.ecn.purdue.edu
ihnp4!pur-ee!davy

*** /tmp/,RCSt1016242	Sat Dec 27 19:02:43 1986
--- dumpmain.c	Sun Aug  3 12:43:40 1986
***************
*** 10,15
  
  #include "dump.h"
  
  int	notify = 0;	/* notify operator flag */
  int	blockswritten = 0;	/* number of blocks written on current tape */
  int	tapeno = 0;	/* current tape number */

--- 10,18 -----
  
  #include "dump.h"
  
+ #if PURDUE_EE
+ int	filepass;
+ #endif
  int	notify = 0;	/* notify operator flag */
  int	blockswritten = 0;	/* number of blocks written on current tape */
  int	tapeno = 0;	/* current tape number */
***************
*** 287,292
   	pass(dirdump, dirmap);
  
  	msg("dumping (Pass IV) [regular files]\n");
  	pass(dump, nodmap);
  
  	spcl.c_type = TS_END;

--- 290,298 -----
   	pass(dirdump, dirmap);
  
  	msg("dumping (Pass IV) [regular files]\n");
+ #if PURDUE_EE
+ 	filepass = 1;
+ #endif
  	pass(dump, nodmap);
  #if PURDUE_EE
  	filepass = 0;
***************
*** 288,293
  
  	msg("dumping (Pass IV) [regular files]\n");
  	pass(dump, nodmap);
  
  	spcl.c_type = TS_END;
  #ifndef RDUMP

--- 294,302 -----
  	filepass = 1;
  #endif
  	pass(dump, nodmap);
+ #if PURDUE_EE
+ 	filepass = 0;
+ #endif
  
  	spcl.c_type = TS_END;
  #ifndef RDUMP

*** /tmp/,RCSt1016249	Sat Dec 27 19:03:03 1986
--- dumptraverse.c	Sun Aug  3 12:43:50 1986
***************
*** 7,12
  #ifndef lint
  static char sccsid[] = "@(#)dumptraverse.c	5.3 (Berkeley) 1/9/86";
  #endif not lint
  
  #include "dump.h"
  

--- 7,15 -----
  #ifndef lint
  static char sccsid[] = "@(#)dumptraverse.c	5.3 (Berkeley) 1/9/86";
  #endif not lint
+ #if PURDUE_EE
+ extern	filepass;
+ #endif
  
  #include "dump.h"
  
***************
*** 45,50
  		BIS(ino, dirmap);
  	if ((ip->di_mtime >= spcl.c_ddate || ip->di_ctime >= spcl.c_ddate) &&
  	    !BIT(ino, nodmap)) {
  		BIS(ino, nodmap);
  		if (f != IFREG && f != IFDIR && f != IFLNK) {
  			esize += 1;

--- 48,60 -----
  		BIS(ino, dirmap);
  	if ((ip->di_mtime >= spcl.c_ddate || ip->di_ctime >= spcl.c_ddate) &&
  	    !BIT(ino, nodmap)) {
+ #if PURDUE_EE
+ 		if (ip->di_mtime >= spcl.c_date || ip->di_ctime >= spcl.c_date){
+ 			if (f != IFDIR) {
+ 				return;
+ 			}
+ 		}
+ #endif
  		BIS(ino, nodmap);
  		if (f != IFREG && f != IFDIR && f != IFLNK) {
  			esize += 1;
***************
*** 138,143
  	i = ip->di_mode & IFMT;
  	if (i == 0) /* free inode */
  		return;
  	if ((i != IFDIR && i != IFREG && i != IFLNK) || ip->di_size == 0) {
  		spclrec();
  		return;

--- 148,160 -----
  	i = ip->di_mode & IFMT;
  	if (i == 0) /* free inode */
  		return;
+ #if PURDUE_EE
+ 	if (ip->di_mtime >= spcl.c_date || ip->di_ctime >= spcl.c_date) {
+ 		if (filepass) {
+ 			return;
+ 		}
+ 	}
+ #endif
  	if ((i != IFDIR && i != IFREG && i != IFLNK) || ip->di_size == 0) {
  		spclrec();
  		return;