rsync-2.6.2: NFS clients confused after an rsync [PATCH included]

[Brian Childs]

As a response to my original post, here's a patch that implements my
proposed solution.

I've tested it, and it fixes the problem, but I'm afraid there may be
some hidden consequences of doing this.

If anyone can think of anything, please let me know.

Thanks,
Brian

--- rsync-2.6.2/util.c.orig	2004-05-07 10:06:08.000000000 -0400
+++ rsync-2.6.2/util.c	2004-05-07 11:06:24.000000000 -0400
@@ -127,9 +127,17 @@
 int set_modtime(char *fname, time_t modtime)
 {
 	extern int dry_run;
+	extern int make_backups;
+
 	if (dry_run)
 		return 0;
 
+	if(make_backups) {
+		struct stat sb;
+		if(!lstat(fname, &sb) && S_ISDIR(sb.st_mode))
+		  return 0;
+	}
+
 	if (verbose > 2) {
 		rprintf(FINFO, "set modtime of %s to (%ld) %s",
 			fname, (long) modtime,

On Thu, May 06, 2004 at 06:21:55PM -0400, Brian Childs wrote:
> We use rsync to update an nfs server.  After an update, we noticed that
> a large number of clients didn't see the updated data.
> 
> It took me a while to be able to reliably reproduce this problem, but it
> happens on old and new versions of rysnc.  It also happens across all
> the platforms we use here (sun/linux/netapp).
> 
> This shows the problem: [Note my home directory is NFS mounted]
> 
> ***************************************************
> rm -f /tmp/testpath/* $HOME/testpath/*
> 
> #Prime it
> echo some data > /tmp/testpath/testfile
> sleep 1
> rsync -a /tmp/testpath/ $HOME/testpath/
> ssh $otherbox ls -li $HOME/testpath
> 
> #Break it
> echo additional data >> /tmp/testpath/testfile
> sleep 1
> rsync -a -b /tmp/testpath/ $HOME/testpath/
> ssh $otherbox ls -li $HOME/testpath
> 
> #Fix it
> touch $HOME/testpath
> ssh $otherbox ls -li $HOME/testpath
> ***************************************************
> 
> Here's the output:
> total 0
>     483079 -rw-r--r--   1 brian    source        10 May  6 18:05 testfile
> total 0
>     483079 -rw-r--r--   1 brian    source        10 May  6 18:05 testfile
> total 0
>     483080 -rw-r--r--   1 brian    source        26 May  6 18:05 testfile
>     483079 -rw-r--r--   1 brian    source        10 May  6 18:05 testfile~
> 
> The output from the "break it" section matches "prime it", but it should
> match the "fix it" output.
> 
> What I think is happening:
> --------------------------
> 
> * testfile is updated in place, so the mtime of testpath
>   isn't udpated.
> * The nfs client is caching the mtime of "testpath"
> * The seconds rsync modifies the contents of testpath, but
>   when finished, it resets the mtime on "testpath"
> * The client believes it's cache is valid, so I doesn't refresh, and
>   therefore it misses the update
> 
> NFS Clients tested: sun (solaris 8 & 9), linux (2.4.18 & 2.4.24)
> NFS Servers tested: sun, linux, and netapp.
> 
> They all behaved the same.
> 
> Proposed fix:
> -------------
> Change rsync so it doesn't reset mtimes on directories if --backup is
> in effect.
> 
> Thanks,
> Brian
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