Re: Parted-2.3 can not detecte USB disk partition(SandDiak CRUZER SDCZ6-016G 16GB), but parted-1.8.8.

[ChenMin]

> ChenMin wrote:
>> THe model of USB disk is "SandDiak CRUZER SDCZ6-016G 16GB", and there
>> is one signal partition on it.
>>
>> GNU Parted 2.3
>> Using /dev/sde
>> Welcome to GNU Parted! Type 'help' to view a list of commands.
>> (parted) p
>> Model: SanDisk Cruzer (scsi)
>> Disk /dev/sde: 16.0GB
>> Sector size (logical/physical): 512B/512B
>> Partition Table: msdos
>> Number Start End Size Type File system Flags
>> (parted)
>>
>>
>> GNU Parted 1.8.8
>> Using /dev/sde
>> Welcome to GNU Parted! Type 'help' to view a list of commands.
>> (parted) p
>> Model: SanDisk Cruzer (scsi)
>> Disk /dev/sde: 16.0GB
>> Sector size (logical/physical): 512B/512B
>> Partition Table: loop
>> Number Start End Size File system Flags
>> 1 0.00B 16.0GB 16.0GB fat32
>> (parted)
>
> Thanks for reporting that regression.
> I've reproduced it like this:
>
> $ dd if=/dev/null of=F bs=1 seek=40M
> $ mkfs.vfat -F 16 F
> $ parted -s F print
> Model: (file)
> Disk /f12/home/meyering/w/co/parted/parted/F: 41.9MB
> Sector size (logical/physical): 512B/512B
> Partition Table: msdos
>
> Number Start End Size Type File system Flags
>
> Note there is no partition listed above.
> Repeating the final command using parted built with
> the patch below, it works as expected:
>
> $ parted/parted -s F print|grep fat
> 1 0.00B 41.9MB 41.9MB fat16
>
> I'll use something like the following patch,
> once I've written a test:
>
> From 7167b646e82dd29372a0239bec0bc9053bae678b Mon Sep 17 00:00:00 2001
> From: Jim Meyering
> Date: Wed, 14 Jul 2010 19:16:14 -0500
> Subject: [PATCH] libparted: avoid regression when processing a whole-disk FAT 
> partition
>
> Without this change, we would improperly classify a whole-disk partition
> containing a FAT file system as a DOS partition table with no partitions.
> Introduced by commit d732a2b7 on 2008-05-28.
> * libparted/labels/dos.c (maybe_FAT): New function.
> (msdos_probe): Use it.
> Reported by ChenMin in
> http://thread.gmane.org/gmane.comp.gnu.parted.bugs/10115
> ---
> libparted/labels/dos.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 75 insertions(+), 0 deletions(-)
>
> diff --git a/libparted/labels/dos.c b/libparted/labels/dos.c
> index f66ca47..d9e7d4a 100644
> --- a/libparted/labels/dos.c
> +++ b/libparted/labels/dos.c
> @@ -164,6 +164,73 @@ typedef struct {
>
> static PedDiskType msdos_disk_type;
>
> +#if 0
> +From http://www.win.tue.nl/~aeb/linux/fs/fat/fat-1.html
> +
> +The 2-byte numbers are stored little endian (low order byte first).
> +
> +Here the FAT12 version, that is also the common part of the FAT12, FAT16 and 
> FAT32 boot sectors. See further below.
> +
> +Bytes Content
> +0-2 Jump to bootstrap (E.g. eb 3c 90; on i86: JMP 003E NOP.
> + One finds either eb xx 90, or e9 xx xx.
> + The position of the bootstrap varies.)
> +3-10 OEM name/version (E.g. "IBM 3.3", "IBM 20.0", "MSDOS5.0", "MSWIN4.0".
> + Various format utilities leave their own name, like "CH-FOR18".
> + Sometimes just garbage. Microsoft recommends "MSWIN4.1".)
> + /* BIOS Parameter Block starts here */
> +11-12 Number of bytes per sector (512)
> + Must be one of 512, 1024, 2048, 4096.
> +13 Number of sectors per cluster (1)
> + Must be one of 1, 2, 4, 8, 16, 32, 64, 128.
> + A cluster should have at most 32768 bytes. In rare cases 65536 is OK.
> +14-15 Number of reserved sectors (1)
> + FAT12 and FAT16 use 1. FAT32 uses 32.
> +16 Number of FAT copies (2)
> +17-18 Number of root directory entries (224)
> + 0 for FAT32. 512 is recommended for FAT16.
> +19-20 Total number of sectors in the filesystem (2880)
> + (in case the partition is not FAT32 and smaller than 32 MB)
> +21 Media descriptor type (f0: 1.4 MB floppy, f8: hard disk; see below)
> +22-23 Number of sectors per FAT (9)
> + 0 for FAT32.
> +24-25 Number of sectors per track (12)
> +26-27 Number of heads (2, for a double-sided diskette)
> +28-29 Number of hidden sectors (0)
> + Hidden sectors are sectors preceding the partition.
> + /* BIOS Parameter Block ends here */
> +30-509 Bootstrap
> +510-511 Signature 55 aa
> +#endif
> +
> +/* There is a significant risk of misclassifying (as msdos)
> + a disk that is composed solely of a single FAT partition.
> + Return false if sector S could not be a valid FAT boot sector.
> + Otherwise, return true. */
> +static bool
> +maybe_FAT (unsigned char const *s)
> +{
> + if (! (s[0] == 0xeb || s[0] == 0xe9))
> + return false;
> +
> + unsigned int sector_size = PED_LE16_TO_CPU (*(uint16_t *) (s + 11));
> + switch (sector_size)
> + {
> + case 512:
> + case 1024:
> + case 2048:
> + case 4096:
> + break;
> + default:
> + return false;
> + }
> +
> + if (! (s[21] == 0xf0 || s[21] == 0xf8))
> + return false;
> +
> + return true;
> +}
> +
> static int
> msdos_probe (const PedDevice *dev)
> {
> @@ -191,12 +258,20 @@ msdos_probe (const PedDevice *dev)
> * and ensure that each partition has a boot indicator that is
> * either 0 or 0x80.
> */
> + unsigned int n_active = 0;
> for (i = 0; i < DOS_N_PRI_PARTITIONS; i++) {
> + if (part_table->partitions[i].boot_ind == 0x80)
> + ++n_active;
> if (part_table->partitions[i].boot_ind != 0
> && part_table->partitions[i].boot_ind != 0x80)
> goto probe_fail;
> }
>
> + /* If there are no active partitions and this is probably
> + a FAT file system, do not classify it as msdos. */
> + if (n_active == 0 && maybe_FAT (label))
> + goto probe_fail;
> +
> /* If this is a GPT disk, fail here */
> for (i = 0; i < DOS_N_PRI_PARTITIONS; i++) {
> if (part_table->partitions[i].type == PARTITION_GPT)
> --
> 1.7.1.460.gf3c4c

Hi Jim,

Thanks very much for your work.

BRs!                                      
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