Re: GPT name overflow

[Andreas Dilger]

On Jan 31, 2002  01:35 +1100, Andrew Clausen wrote:
> On Mon, Jan 28, 2002 at 03:58:05PM -0700, Andreas Dilger wrote:
> > 1) Entering a long name (over the 36 unicode character limit, I think)
> >    made it abort with "Error during translation: Invalid or incomplete
> >    multibyte or wide character".  I tried it with an 80-char input of
> >    "aaa...aaa" and it worked OK (result truncated to 36 chars), but the
> >    string "this is a long name which hopes to be too long" causes it
> >    to abort on repeated tests.
> 
> I can't reproduce this.
> 
> At what point does it die?  Does enabling/disabling i18n make a difference?

Hmm, I was able (on subsequent tests) to get it to fail with "this is a long
name which h" but not "this is a long name which ".  This is with 1.5.6.  I
also tried with 1.6.0p2 with the same results.  Note that the name does not
even overflow the 36 (I think) character limit.

> > 2) (this may be a parted usability bug and not GPT specific) if I try to
> >    new partition and I specify a starting location which is the same as
> >    the end of the previous partition it complains that the partitions
> >    are overlapping instead of adding a small fudge factor.  If I manually
> >    add .001 to the starting location it works, and often "print" will
> >    report the starting location as being the same as the end of the
> >    previous partition, e.g.
> > 
> >    (parted) p 
> >    Disk geometry for /tmp/gpt: 0.000-10240.000 megabytes
> >    Disk label type: gpt
> >    Minor    Start       End     Filesystem  Name                  Flags
> >    1          0.017    100.000              test_label            
> >    (parted) mkpart p 100 200
> >    Error: The new partition overlaps with another partition.
> >    (parted) mkpart p 100.001 200
> >    (parted) p
> >    Disk geometry for /tmp/gpt: 0.000-10240.000 megabytes
> >    Disk label type: gpt
> >    Minor    Start       End     Filesystem  Name                  Flags
> >    1          0.017    100.000              test_label            
> >    2        100.000    200.000
> 
> Yep, this should be "fixed".  Just, I've been procrastinating about
> a nice clean/general solution.  There are a few special cases.
> 
> How does this sound:
> * if (geom->start + geom->end)/2 is freespace then set geom to
> ped_geometry_intersect (geom,
>       &ped_disk_get_part_by_sector (disk, (geom->start + geom->end)/2)
>               ->geom)
> where geom is what the user specified.  Actually, a bit more
> bureaucracy, to only move within a certain fudge-factor.
> (That bit is already implemented)

What about:
    if (geom->start == (geom prev)->end)
        then geom->start = (geom prev)->end + 1;

I don't know how hard it is to do this, but you need to have access to
the (geom prev)->end _somewhere_ in order to check if it is overlapping.

> > 3) Since GPT only supports primary partitions (and probably other label
> >    types also), it would be nice to avoid having it ask what partition
> >    type when working in interactive mode.  This is probably true of any
> >    input which only has a single choice.  I can see that you might need
> >    to keep it for single command-line inputs to make the parsing sane.
> 
> Yep, I thought I already implemented this...
> 
> one gotcha:
> 
> There might be two "options" that are the english and native
> versions of the same thing.  So, either we have to implement this
> at a higher level (PITA), or the UI code should know the difference
> between native and english words.  I think we need the later anyway.

I did this last night for the partition type (which is the one which I
see most when doing GPT partitions == always primary).  Untested patch below.

Yes, having the low-level code also handle translations would be nice.
Maybe by keeping the translated word in the same option for display,
and the call to command_line_get_word() only returns the english word?
That would also simplify the resulting checks.

> > 4) GPT doesn't seem to keep the "type" of a partition, or parted doesn't
> >    print it out with 'p' correctly.  It is my understanding that GPT has
> >    GUIDs instead of single-byte partition types,
> 
> Right.
> 
> > so parted should probably
> >    print these as flags, but it does not (unlike msdos partitions):
> > 
> >    (parted) set 1 boot on
> >    (parted) set 2 raid on
> >    (parted) set 3 lvm on
> >    (parted) p
> >    Disk geometry for /tmp/gpt: 0.000-10240.000 megabytes
> >    Disk label type: gpt
> >    Minor    Start       End     Filesystem  Name                  Flags
> >    1          0.017    100.000              test_label            
> >    2        100.000    200.000                                    
> >    3        200.000    300.000                                    
> 
> You found a bug.  Thanks :)

I checked the GPT code, and it does appear to set the "flags" correctly.
Sadly, even though GPT uses 16 bytes for the UUID storage, you can only
set a single "flag" at one time (i.e. you can't have a boot RAID partition).
It must just not do the later comparison to display the flags.

Cheers, Andreas
======================== parted-1.6.0-pre2-type.diff =========================
--- parted/ui.c.orig    Sat Jan 12 14:17:55 2002
+++ parted/ui.c Wed Jan 30 11:44:10 2002
@@ -684,22 +684,27 @@
                                PedPartitionType* type)
 {
        StrList*        opts = NULL;
-       char*           type_name;
+       char*           type_name = NULL;
+       int             num = 0;
 
        if (_can_create_primary (disk)) {
-               opts = str_list_append_unique (opts, "primary");
+               opts = str_list_append_unique (opts, (type_name = "primary"));
                opts = str_list_append_unique (opts, _("primary"));
+               num++;
        }
        if (_can_create_extended (disk)) {
-               opts = str_list_append_unique (opts, "extended");
+               opts = str_list_append_unique (opts, (type_name = "extended"));
                opts = str_list_append_unique (opts, _("extended"));
+               num++;
        }
        if (_can_create_logical (disk)) {
-               opts = str_list_append_unique (opts, "logical");
+               opts = str_list_append_unique (opts, (type_name = "logical"));
                opts = str_list_append_unique (opts, _("logical"));
+               num++;
        }
 
-       type_name = command_line_get_word (prompt, NULL, opts, 1);
+       if (num > 1)
+               type_name = command_line_get_word (prompt, NULL, opts, 1);
        str_list_destroy (opts);
 
        if (!type_name) {
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/