rsync - Mar 2004 - Problem with --link-dest when syncing AIX to Linux

Hello,

i'm using rsync 2.6.0 for daily-syncing some remote AIX 5.2 machine to a 
local linux (RH 7.3) with using the --link-dest option for saving space 
on incremental backups.

Even if there are no changes on the AIX machine, all files are newly 
transferred on every new sync.

My test scenario (actisi=remote aix machine, actisa=local linux machine):

=====> Initial rsync

[mma@actisa rsync-2.6.0]$ ./rsync -av actisi:remotetest/ test1/
receiving file list ... done
./
file1
file2

wrote 56 bytes  read 203 bytes  103.60 bytes/sec
total size is 14  speedup is 0.05

=====> Check if anything left...

[mma@actisa rsync-2.6.0]$ ./rsync -av actisi:remotetest/ test1/
receiving file list ... done

wrote 16 bytes  read 101 bytes  46.80 bytes/sec
total size is 14  speedup is 0.12

=====> All fine, now using --link-dest for incremental rsync

[mma@actisa rsync-2.6.0]$ ./rsync -av --link-dest=../test1 
actisi:remotetest/ test2/
receiving file list ... done
./
file1
file2

wrote 68 bytes  read 189 bytes  102.80 bytes/sec
total size is 14  speedup is 0.05

=====> Oooops. Why were file1 and file2 transferred?

I did some debugging and found out that the problem seems to be in the 
function skip_file() in generator.c:

if (link_dest) {
     extern int preserve_perms;
     extern int preserve_uid;
     extern int preserve_gid;

     if(preserve_perms
         && (st->st_mode & ~_S_IFMT) !=  (file->mode &
~_S_IFMT))
         return 0;

This is always true when rsyncing AIX -> linux, look at this gdb output:

(gdb) print /o st->st_mode
$13 = 0100644
(gdb) print /o file->mode
$14 = 0500644

Nasty AIX always adds 0400000 to the file mode which then breaks this 
condition. I've not found anything about this value in the AIX includes 
(mode.h). Is there any way to mask this bit out for AIX to make rsync 
better working?

Regards,

Markus

On Fri, Mar 05, 2004 at 05:14:30PM +0100, Markus Marquardt
wrote:
>     if(preserve_perms
>         && (st->st_mode & ~_S_IFMT) !=  (file->mode &
~_S_IFMT))
>         return 0;
Hmm, the code in rsync.c uses the define CHMOD_BITS (defined in rsync.h)
instead of ~_S_IFMT.  The former looks safer to me and should solve the
problem you mention of having a 0400000 in the AIX mode.

CHMOD_BITS also looks to be a synonym of the "ALLPERMS" define that
(at
least some) systems provide.  I think the attached patch would be an
improvement.

..wayne..
-------------- next part --------------
--- rsync.h	6 Mar 2004 07:43:55 -0000	1.188
+++ rsync.h	6 Mar 2004 08:02:29 -0000
@@ -609,7 +609,9 @@ extern int errno;
 #define S_ISVTX 0
 #endif
 
-#define CHMOD_BITS (S_ISUID | S_ISGID | S_ISVTX | ACCESSPERMS)
+#ifndef ALLPERMS
+#define ALLPERMS (S_ISUID | S_ISGID | S_ISVTX | ACCESSPERMS)
+#endif
 
 #ifndef _S_IFMT
 #define _S_IFMT        0170000
--- generator.c	27 Feb 2004 08:03:49 -0000	1.76
+++ generator.c	6 Mar 2004 08:02:29 -0000
@@ -53,7 +53,7 @@ static int skip_file(char *fname, struct
 	}
 	if (link_dest) {
 		if (preserve_perms
-		    && (st->st_mode & ~_S_IFMT) != (file->mode &
~_S_IFMT))
+		    && (st->st_mode & ALLPERMS) != (file->mode &
ALLPERMS))
 			return 0;
 
 		if (am_root && preserve_uid && st->st_uid != file->uid)
@@ -295,7 +295,7 @@ void recv_generator(char *fname, struct 
 		/* if the file exists already and we aren't perserving
 		 * permissions then act as though the remote end sent
 		 * us the file permissions we already have */
-		file->mode = (file->mode & _S_IFMT) | (st.st_mode & ~_S_IFMT);
+		file->mode = (file->mode & ~ALLPERMS) | (st.st_mode &
ALLPERMS);
 	}
 
 	if (S_ISDIR(file->mode)) {
--- rsync.c	25 Feb 2004 21:20:59 -0000	1.133
+++ rsync.c	6 Mar 2004 08:02:29 -0000
@@ -190,9 +190,9 @@ int set_perms(char *fname,struct file_st
 
 #ifdef HAVE_CHMOD
 	if (!S_ISLNK(st->st_mode)) {
-		if ((st->st_mode & CHMOD_BITS) != (file->mode & CHMOD_BITS)) {
+		if ((st->st_mode & ALLPERMS) != (file->mode & ALLPERMS)) {
 			updated = 1;
-			if (do_chmod(fname,(file->mode & CHMOD_BITS)) != 0) {
+			if (do_chmod(fname,(file->mode & ALLPERMS)) != 0) {
 				rprintf(FERROR, "failed to set permissions on %s: %s\n",
 					full_fname(fname), strerror(errno));
 				return 0;

On Sat, Mar 06, 2004 at 12:10:29AM -0800, Wayne Davison
wrote:
> CHMOD_BITS also looks to be a synonym of the "ALLPERMS" define
that
> (at least some) systems provide. [...]
I opted for the safer patch of leaving CHMOD_BITS alone and using that
define in generator.c in place of _S_IFMT (with bits reversed, of
course).

..wayne..