rsync - Apr 2006 - --link-dest and file/dir transfer to remote rsync daemon

Hi NG,

I want to do incremental backups to a remote server running rsyncd
(because daemonless transfer via ssh often hangs!). In contrast to
transfer via ssh (without remote rsyncd) this doesn't seem possible, or
do I miss something?

Imagine I want to incrementally backup `mydir' to the backup space
`backup' on e remote server `alpha' running an rsync daemon. rsyncd on
`alpha' is configured as follows:

  [backup]
    path = /home/grahn/backupdir

If I run:

  rsync --port=54321 -a -v --link-dest=../yesterday mydir alpha::backup/today

on the local machine, the directory structure

  /home/grahn/backupdir/today/mydir/test.txt

is created on remote `alpha'. Contrary to what was expected, the file
`test.txt' which hasn't changed since yesterday is not hard linked to

  /home/grahn/backupdir/yesterday/mydir/test.txt

On the other hand this works (transfer via ssh tunnel):

  rsync -a -v --link-dest=../yesterday mydir alpha:backupdir/today

The hard link is created, as expected.

What's wrong with the first (remote rsyncd) approach?

Thanks for any piece of advice!

Alex

On Wed, Apr 26, 2006 at 03:22:49PM +0200, Alexander Grahn
wrote:
>   rsync --port=54321 -a -v --link-dest=../yesterday mydir
alpha::backup/today
If you don't have "use chroot = yes" in your daemon config, rsync
can
get overzealous in its sanitizing of the options and eliminate the ../
from your --link-dest option.  I'd suggest using "/yesterday"
instead,
since that will anchor at the root of the module in any modern rsync.

..wayne..

On Thu, Apr 27, 2006 at 09:48:17AM -0700, Wayne Davison
wrote:
> rsync can get overzealous in its sanitizing of the options and
> eliminate the ../ from your --link-dest option.
The attached patch fixed the overzealous sanitizing of the various
--*-dest options by factoring in the depth of the destination dir
for the transfer.  This has been checked into CVS.

..wayne..
-------------- next part --------------
--- main.c	25 Apr 2006 23:51:15 -0000	1.302
+++ main.c	28 Apr 2006 16:56:38 -0000
@@ -49,6 +49,8 @@ extern int preserve_hard_links;
 extern int protocol_version;
 extern int recurse;
 extern int relative_paths;
+extern int sanitize_paths;
+extern int module_id;
 extern int rsync_port;
 extern int whole_file;
 extern int read_batch;
@@ -59,10 +61,13 @@ extern int filesfrom_fd;
 extern pid_t cleanup_child_pid;
 extern struct stats stats;
 extern char *filesfrom_host;
+extern char *basis_dir[];
 extern char *rsync_path;
 extern char *shell_cmd;
 extern char *batch_name;
 
+extern char curr_dir[MAXPATHLEN];
+
 int local_server = 0;
 mode_t orig_umask = 0;
 struct file_list *the_file_list;
@@ -785,6 +790,16 @@ static void do_server_recv(int f_in, int
 	if (argc > 0)
 		local_name = get_local_name(flist,argv[0]);
 
+	/* Now that we know what our destination directory turned out to be,
+	 * we can sanitize the --link-/copy-/compare-dest args correctly. */
+	if (sanitize_paths) {
+		char *dest_path = curr_dir + strlen(lp_path(module_id));
+		int dest_depth = count_dir_elements(dest_path);
+		char **dir;
+		for (dir = basis_dir; *dir; dir++)
+			*dir = sanitize_path(NULL, *dir, NULL, dest_depth);
+	}
+
 	exit_code = do_recv(f_in,f_out,flist,local_name);
 	exit_cleanup(exit_code);
 }
--- options.c	25 Apr 2006 23:51:15 -0000	1.334
+++ options.c	28 Apr 2006 16:56:38 -0000
@@ -1048,10 +1048,9 @@ int parse_arguments(int *argc, const cha
 					MAX_BASIS_DIRS, dest_option);
 				return 0;
 			}
-			arg = poptGetOptArg(pc);
-			if (sanitize_paths)
-				arg = sanitize_path(NULL, arg, NULL, 0);
-			basis_dir[basis_dir_cnt++] = (char *)arg;
+			/* We defer sanitizing this arg until we know what
+			 * our destination directory is going to be. */
+			basis_dir[basis_dir_cnt++] = (char *)poptGetOptArg(pc);
 			break;
 
 		case OPT_CHMOD: