Jim Meyering a écrit :
Jean-Christian de Rivaz wrote:
Jim Meyering a écrit :
Jean-Christian de Rivaz wrote:
[...]
r...@point:/home/jcdr/parted-git/parted/build-O0# parted/parted
/dev/sdb print
Model: disk2go PURE II (scsi)
Disk /dev/sdb: 5243kB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 5120B 5243kB 5238kB primary
[...]
Now I just wonder if parted should display FAT16 in the file system
field. Because fdisk do it:
r...@point:/home/jcdr/parted-git/parted/build-O0# fdisk -l /dev/sdb
Disk /dev/sdb: 5 MB, 5242880 bytes
1 heads, 10 sectors/track, 1024 cylinders
Units = cylinders of 10 * 512 = 5120 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 2 1024 5115 6 FAT16
[...]
It seems that 4MiB is the minimum size of a FAT16 file system,
and at 2.5MiB, yours is well under the minimum, so with the latter
interpretation, parted is correct not to report it as one.
Sorry, I failed to find where this /deb/sdb1 partition is 2.5MiB in
size. Seem to be 5.1MiB (5238kB, or (1024-2+1)*512*10/2.0**20=4.99MiB
according to fdisk) to me ( > 4MiB ). This is also confirmed by the
system while mounting the /deb/sdb1 partition:
Oh. I looked at sdb1's partition size, rather than the device size.
Thanks for the correction. In that case, it sounds like a bug.
Can you debug it?
I have traced the problem to the fat_boot_sector_probe_type() function
from the file libparted/fs/fat/bootsector.c. In particular the last
couple of lines:
if (cluster_count > MAX_FAT12_CLUSTERS)
return FAT_TYPE_FAT16;
else
return FAT_TYPE_FAT12;
And in fat.h, MAX_FAT12_CLUSTERS has value 4086. The small FAT16
partition on my /dev/sdb1 have cluster_count = 2544, so the function
returns FAT_TYPE_FAT12. Since parted don't support FAT12, it do not
display this file system type. I found curious that the "File system is
FAT12, which is unsupported." from the fat_boot_sector_analyse() is not
displayed. I tested to change MAX_FAT12_CLUSTERS to 2048 and parted
report a fat16 file system for my /dev/sdb1.
A this point I fail to understand why parted probe the file system type
this way as the primary information should be the partition identifier
from the MBR: 0x01 for FAT12 and 0x04, 0x06, 0x0E for FAT16.
If we found a way to get the partition identifier from the
fat_boot_sector_probe_type() function, the code could be something like
this:
if (partition_identifier == 0x01 &&
cluster_count <= MAX_FAT12_CLUSTERS)
return FAT_TYPE_FAT12;
else
return FAT_TYPE_FAT16;
If this proposition is reasonable, my problem is how to get the
partition_identifier.
Or should we use an other way to make the difference between FAT12 and
FAT16 ?
Jean-Christian de Rivaz
_______________________________________________
bug-parted mailing list
bug-parted@gnu.org
http://lists.gnu.org/mailman/listinfo/bug-parted
