Linux hfsplus corrupts chflags bits?

From: Paolo Giarrusso
Date: Thu Sep 13 2012 - 17:26:25 EST


[Please CC me on replies as I'm not subscribed.]

The Linux hfsplus implementation seems to repeatedly corrupt
hfsplus_perm->rootflags; when the same filesystem is read on Mac OS X,
this changes the attribs touched by chflags and makes a random
selection of files "locked" and thus untouchable. This happened for me
on Ubuntu 12.04 "Precise Pangolin", based on a 3.2.0 kernel, reports
appear from various other versions and the source doesn't seem heavily
changed.

I've had experience of this, shared by other users on this
superuser.com discussion:
http://superuser.com/a/457494/46794

Given that hfsplus isn't even mentioned in MAINTAINERS, I've used
./scripts/get_maintainer.pl to select recipients.

To convince you that the flags are in fact set randomly, here's a
listing of the backup of my home created through rsync on Linux (which
supposedly isn't even aware of these flags). Notice: none of these
flags are supposed to be set.

# 'ls' -ld -O /Volumes/HFS+Backup/Users/pgiarrusso/*
drwx------ 31 pgiarrusso staff uchg,nodump,opaque 1054 Aug
13 02:00 /Volumes/HFS+Backup/Users/pgiarrusso/Desktop
drwx------ 36 pgiarrusso staff nodump 1224 Jul
22 16:04 /Volumes/HFS+Backup/Users/pgiarrusso/Documents
drwx------ 108 pgiarrusso staff uappnd 3672 Aug
13 11:43 /Volumes/HFS+Backup/Users/pgiarrusso/Downloads
drwx------ 13 pgiarrusso staff uappnd,uchg,opaque 442 Jul
22 05:04 /Volumes/HFS+Backup/Users/pgiarrusso/Dropbox
drwx------ 53 pgiarrusso staff - 1802 Aug
12 00:58 /Volumes/HFS+Backup/Users/pgiarrusso/Library
drwx------ 11 pgiarrusso staff uchg,nodump,opaque 374 Jul
22 17:25 /Volumes/HFS+Backup/Users/pgiarrusso/Movies
drwx------ 13 pgiarrusso staff uappnd,uchg,nodump 442 Jun
10 12:05 /Volumes/HFS+Backup/Users/pgiarrusso/Music
drwx------ 15 pgiarrusso staff uappnd,nodump,opaque 510 Jun
10 12:05 /Volumes/HFS+Backup/Users/pgiarrusso/Pictures
drwxr-x--- 11 pgiarrusso staff opaque 374 Jul
6 15:33 /Volumes/HFS+Backup/Users/pgiarrusso/Public
drwxr-xr-x 34 pgiarrusso staff uappnd,uchg,opaque 1156 May
27 12:39 /Volumes/HFS+Backup/Users/pgiarrusso/Sites
drwxr-xr-x 2 pgiarrusso staff uappnd,nodump,opaque 68 Jun
10 21:43 /Volumes/HFS+Backup/Users/pgiarrusso/VirtualBox VMs
-rwxr-xr-x 1 pgiarrusso staff uappnd,nodump,opaque 1703 Feb
19 2012 /Volumes/HFS+Backup/Users/pgiarrusso/bash-prompt.sh
drwxr-xr-x 22 pgiarrusso staff - 748 Aug
10 19:47 /Volumes/HFS+Backup/Users/pgiarrusso/bin
lrwxrwxrwx 1 pgiarrusso staff nodump,opaque 37 Sep
27 2011 /Volumes/HFS+Backup/Users/pgiarrusso/default.sfx ->
/Users/pgiarrusso/opt/rar/default.sfx
-rw-r--r-- 1 pgiarrusso staff uappnd,uchg 1375563169 Aug
2 18:52 /Volumes/HFS+Backup/Users/pgiarrusso/heapdump-1343925310626.hprof
drwxr-xr-x 22 pgiarrusso staff uappnd,nodump 748 Aug
1 22:15 /Volumes/HFS+Backup/Users/pgiarrusso/opt
drwxr-xr-x 7 pgiarrusso staff uappnd 238 Apr
19 20:00 /Volumes/HFS+Backup/Users/pgiarrusso/share
drwxr-xr-x 35 pgiarrusso staff nodump,opaque 1190 Aug
10 00:06 /Volumes/HFS+Backup/Users/pgiarrusso/tmp

Cheers,
--
Paolo 'Blaisorblade' Giarrusso - Ph.D. Student
http://www.informatik.uni-marburg.de/~pgiarrusso/
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