Re: [PATCH] udf: Don't corrupt unalloc spacetable when writing it

From: Jan Kara
Date: Fri Jul 10 2015 - 10:02:12 EST


On Thu 09-07-15 13:20:27, Steve Magnani wrote:
>
>
> On 07/09/2015 10:16 AM, Jan Kara wrote:
> >On Tue 07-07-15 13:06:05, Steven J. Magnani wrote:
> >>For a UDF filesystem configured with an Unallocated Space Table,
> >>a filesystem operation that triggers an update to the table results
> >>in on-disk corruption that prevents remounting:
> >>
> >> udf_read_tagged: tag version 0x0000 != 0x0002 || 0x0003, block 274
> >>
> >>For example:
> >> 1. Create a filesystem
> >> $ mkudffs --media-type=hd --blocksize=512 --lvid=BUGTEST \
> >> --vid=BUGTEST --fsid=BUGTEST --space=unalloctable \
> >> /dev/mmcblk0
> >>
> >> 2. Mount it
> >> # mount /dev/mmcblk0 /mnt
> >>
> >>...
> >So the patch looks good to me. But what kind of mkudffs are you using?
> >Because when I use the command you wrote into the changelog, I cannot mount
> >the filesystem. The kernel complains about:
> >
> >UDF-fs: error (device ubdb): udf_read_inode: (ino 274) failed ident=256
> >mount: /dev/ubdb: can't read superblock
> >
> >Now ident 256 is TAG_IDENT_FSD (file set descriptor). So apparently my
> >mkudffs doesn't create proper partition table with your parameters...
> >
> >
> It identifies itself as:
> mkudffs 1.0.0b2 for UDF FS 1.0.0-cvs, 2002/02/09
>
> ...from Ubuntu udftools 1.0.0b3-14.2.

OK, I've fixed my mkudffs and verified that your patch indeed fixes the
problem. Thanks. I have merged the patch to my tree and will push it to
Linus.

Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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