rsync - Sep 2010 - DO NOT REPLY [Bug 7685] New: rsync should not set the creation data on the root folder of an HFS+ volume

https://bugzilla.samba.org/show_bug.cgi?id=7685

           Summary: rsync should not set the creation data on the root
                    folder of an HFS+ volume
           Product: rsync
           Version: 3.0.7
          Platform: x86
        OS/Version: Mac OS X
            Status: NEW
          Severity: normal
          Priority: P3
         Component: core
        AssignedTo: wayned at samba.org
        ReportedBy: mike at bombich.com
         QAContact: rsync-qa at samba.org


HFS+ uses the creation date of the root folder as one reference for identifying
hard link references. See
http://developer.apple.com/library/mac/technotes/tn/tn1150.html#HardLinks for
the reference (albeit only two lines and not particularly explicit). I have
reproduced undesirable hard link behavior on Tiger, Leopard, and Snow Leopard
using the following script (as you can see, this is certainly an edge case, but
I have run into it several times):

##############
#!/bin/sh

source=/Volumes/HLSource
target=/Volumes/HLTarget
rsync="/usr/local/bin/rsync"

cd /tmp
echo "Creating temporary source disk image"
hdiutil create -size 1m -volname HLSource -fs HFS+ -layout NONE -attach
HLSource.dmg 1> /dev/null

echo "Creating temporary target disk image (after a delay to guarantee
different creation date)"
sleep 2
hdiutil create -size 1m -volname HLTarget -fs HFS+ -layout NONE -attach
HLTarget.dmg 1> /dev/null
tgt_dev=`df | awk '/HLTarget/ {print $1}'`

stat -f "  %N: Creation date: %B" $target

echo ""
echo "rsyncing /Volumes/HLSource to target."
$rsync -aHNx --include="/" --exclude=".*"
--exclude="*" $source/ $target 1>
/dev/null

stat -f "  %N: Creation date: %B" $target

echo ""
echo "Unmounting and remounting the target"
diskutil unmount $tgt_dev 1> /dev/null
diskutil mount $tgt_dev 1> /dev/null

echo "Creating a hard link on the target"
touch $target/one
ln $target/one $target/one_link
stat -f "  %N: inode: %i, Link count: %l" $target/one

echo ""
echo "rsyncing / to target"
$rsync -aHNx --include="/" --exclude=".*"
--exclude="*" / $target 1> /dev/null

stat -f "  %N: Creation date: %B" $target

echo ""
echo "Unmounting and remounting the target"
diskutil unmount $tgt_dev 1> /dev/null
diskutil mount $tgt_dev 1> /dev/null

echo "Creating another hard link on the target"
touch $target/two
ln $target/two $target/two_link
stat -f "  %N: inode: %i, Link count: %l" $target/one
stat -f "  %N: inode: %i, Link count: %l" $target/two

#echo "Unmounting and remounting the target"
#diskutil unmount $tgt_dev 1> /dev/null
#diskutil mount $tgt_dev 1> /dev/null

#echo "File list of target root dir"
#stat -f "%N: inode: %i, Link count: %l" $target/one
#stat -f "%N: inode: %i, Link count: %l" $target/two

echo "Cleaning up"
hdiutil eject $source 1> /dev/null
hdiutil eject $target 1> /dev/null
rm /tmp/HLSource.dmg
rm /tmp/HLTarget.dmg

##############

This is yet another filesystem-specific patch, I doubt you would want to commit
this in its current form.  Ultimately I think we need a separate object within
rsync that we can query for filesystem-specific behavior like this.

This patch (from rsync 3.0.7+fileflags+crtimes) resolves the matter:

##############
crtimes-hfs+.patch
This patch prevents rsync from changing the creation date on the root of a
volume. On HFS+, the root inode is always 2, as defined in hfs/hfs_format.h:

kHFSRootFolderID                = 2,    /* Folder ID of the root folder */

So before calling set_create_time(), we verify from the existing stat struct
that the inode of the current file is not 2.

diff -Naur rsync-3.0.7_orig/rsync.c rsync-3.0.7/rsync.c
--- rsync-3.0.7_orig/rsync.c    2010-09-16 10:49:54.000000000 -0500
+++ rsync-3.0.7/rsync.c 2010-09-16 10:50:43.000000000 -0500
@@ -480,6 +480,7 @@
                if (sxp->crtime == 0)
                        sxp->crtime = get_create_time(fname);
                if (cmp_time(sxp->crtime, file_crtime) != 0
+                && sxp->st.st_ino != 2 // Don't set the creation
date on the
root folder of an HFS+ volume
                 && set_create_time(fname, file_crtime) == 0)
                        updated = 1;
        }
##############


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------- Comment #1 from mike at bombich.com  2010-09-16 14:18 CST -------
Created an attachment (id=5966)
 --> (https://bugzilla.samba.org/attachment.cgi?id=5966&action=view)
patch to the crtimes patch


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------- Comment #2 from wayned at samba.org  2010-09-18 12:35 CST -------
Created an attachment (id=5969)
 --> (https://bugzilla.samba.org/attachment.cgi?id=5969&action=view)
Avoid setting inode 2 if it is a directory.

Here is my version of the fix.


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------- Comment #3 from mike at bombich.com  2010-09-19 21:56 CST -------
Ah yes, avoid another getattrlist, good idea.  Looks great, thanks!


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wayned at samba.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
            Version|3.0.7                       |3.0.8




------- Comment #4 from wayned at samba.org  2011-01-03 18:31 CST -------
Will be released in 3.0.8.


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