How to change HAL mount options in GNOME

tung · 2010-03-08 09:33:41

I recently reinstalled Arch from a clean slate, i.e. wiped my disks before installing. This moved me from GNOME 2.26 to 2.28, of which I have a typical install.

My external hard disk has special characters in its filenames. They displayed fine before, but now they just show up as garbage.

I found that I could fix this by unmounting, then remounting the disk without the utf8=1 option.

Here's what an automatic, non-interactive mount looks like.

$ tail -n 1 /etc/mtab
/dev/sdc1 /media/WD\040Passport vfat rw,nosuid,nodev,uhelper=devkit,uid=1000,gid=100,shortname=mixed,dmask=0077,utf8=1,flush 0 0

Note the utf8=1 near the end.

Problem

How do I make GNOME/HAL omit that "utf8=1" when I hotplug my external hard disk?

Prior research

1. Tweaking HAL *.fdi files didn't work. No modifications to files in /usr/share/hal/fdi/policy/ or /etc/hal/fdi/policy/ made any difference. The most I found was in 20-storage-methods.fdi, with its volume.mount.valid_options keys, but using <remove> rules had no effect.

2. Writing my own *.fdi file in /etc/hal/fdi/policy/ didn't work. Following the HAL docs, I discovered in another link that changing volume.policy.mount_option.utf8 was worthless anyway, as it'd been made obsolete.

3. Setting /system/storage/default_options/vfat/mount_options in GNOME's configuration to [ utf8=0 ] has no effect. In fact the whole thing seems entirely ignored, no matter what options I try to alter. Am I missing something?

I was careful to undo all of my actions between each solution. I still have the setting for the last one, though it doesn't do anything. Running that "tail" command from above gives exactly the same line, even after a reboot.

Any help or experience with solving this would be greatly appreciated.

jarryson · 2010-03-08 12:04:00

gnome won't use hal to mount any more, now use udisks(devicekit-disks)

tung · 2010-03-08 21:08:25

Thanks, that explains a few things. udev seems to be controlled by a bunch of *.rules files, but I'll have time to mess around with them later.

Does anybody have any advice relating to changing default mount options using udev rules?

tung · 2010-03-10 03:27:10

I've done some digging in DeviceKit-disks, and I'm about to butcher some terminology, so feel free to correct me.

DeviceKit-disks seems to present itself as a DBus interface, so it accepts DBus messages that correspond to a bunch of functions, one of which is mount.

The 3rd option of the mount function is a list of option strings that are eventually added to the final "mount ..." command.

DeviceKit-disks uses some default options for some file system types. For "vfat", it's hardcoded to include "uid=", "gid=" (both are filled in specially later in the code), "shortname=mixed", "dmask=0077", and the option I want to cancel: "utf8=1".

The full set of mount options is this list of default options, followed by custom options that I suspect are received via the DBus interface.

Finally, a "mount ..." command line is built, which is shuffled off elsewhere in the source, and presumably checks permissions before running it.

Couple of questions:

1. Is this analysis at all correct?
2. Who calls DeviceKit-disks to auto-mount an external drive?

I believe that whoever calls DeviceKit-disks holds the key to setting/changing the ultimate mount options.

Arch Linux

#1 2010-03-08 09:33:41

How to change HAL mount options in GNOME

#2 2010-03-08 12:04:00

Re: How to change HAL mount options in GNOME

#3 2010-03-08 21:08:25

Re: How to change HAL mount options in GNOME

#4 2010-03-10 03:27:10

Re: How to change HAL mount options in GNOME

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