2002-12-11 07:52:52

by Thomas Frayne

Subject: mounting udf DVD-RAM changes owner

I am running Redhat 8.0 plus Win4Lin 4.0.7 on a Pentium III 600Mhz with 768MB RAM, 4 SCSI hard drives, an IDE hard drive, a Panasonic LF-D201 SCSI DVD-RAM, an HP deskjet 6122, and an HP Scanjet 7450C. The Redhat kernel is 2.4.18-14, and the Win4Lin kernel is a patched version of the Redhat kernel. I have DVD-RAM cartridges formatted FAT32 under Windows XP, and others formatted by udftools-1.0.0b2/mkudffs. The fstab entry of interest is

/dev/scd0 /mnt/dvd auto noauto,users,kudzu,rw,exec,uid=Tom,umask=000 0 0

Before I mount a udf cartridge, I get

[Tom@localhost Tom]$ ls -l /mnt
...
drwxr-xr-x 2 Tom root 4096 Nov 5 11:20 dvd

[Tom@localhost Tom]$ mount /mnt/dvd
[Tom@localhost Tom]$ ls -l /mnt
...
drwxr-xr-x 4 root root 140 Dec 6 19:13 dvd

[Tom@localhost Tom]$ umount /mnt/dvd
[Tom@localhost Tom]$ ls -l /mnt
...
drwxr-xr-x 2 Tom root 4096 Nov 5 11:20 dvd

If I then mount a FAT32 cartridge, I get

[Tom@localhost Tom]$ mount /mnt/dvd
[Tom@localhost Tom]$ ls -l /mnt
...
drwxrwxrwx 3 Tom Tom 16384 Dec 31 1969 dvd
...
[Tom@localhost Tom]$ mount
...
/dev/scd0 on /mnt/dvd type vfat (rw,nosuid,nodev,uid=500,umask=000)


Each time I mount a udf cartridge, I have to do su to chown it before I can write to it in user mode. Both the ownership and the permissions go back to the same root valuse, ignoring the fstab entry, until I do this. The behavior is the same for the Redhat kernel and the Win4Lin kernel.

I can get around this problem by adding myself to the root group, I think, but changing the permissions does not help. I found no clues in the mkudffs man page or in the linux-kernel archives.

Is there some trick for configuring to get around this problem? Is this a bug?

2002-12-11 19:35:49

by Andries Brouwer

Subject: Re: mounting udf DVD-RAM changes owner

On Wed, Dec 11, 2002 at 12:00:33AM -0800, TomF wrote:

> Before I mount a udf cartridge, I get
>
> [Tom@localhost Tom]$ ls -l /mnt
> ...
> drwxr-xr-x 2 Tom root 4096 Nov 5 11:20 dvd
>
> [Tom@localhost Tom]$ mount /mnt/dvd
> [Tom@localhost Tom]$ ls -l /mnt
> ...
> drwxr-xr-x 4 root root 140 Dec 6 19:13 dvd

Read mount(8), especially the sentence

The
previous contents (if any) and owner and mode of dir
become invisible, and as long as this file system remains
mounted, the pathname dir refers to the root of the file
system on device.