2.a.30-rc7: fat filesystem misdetected as amiga

["Michael S. Tsirkin" <mst@redhat.com>]

Hi!
I have a disk on key with 2 partitions:
free hidden partition and after this a fat16
partition.

An attempt to mount it under linux 2.6.30-rc7 results in these messages:

usb 1-3: new high speed USB device using ehci_hcd and address 7
usb 1-3: New USB device found, idVendor=090c, idProduct=6000
usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-3: Product: USB2.0 Card Reader  
usb 1-3: Manufacturer: Generic       ,   . 
usb 1-3: SerialNumber: 0000001       
usb 1-3: configuration #1 chosen from 1 choice
Initializing USB Mass Storage driver...
scsi2 : SCSI emulation for USB Mass Storage devices
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
usb-storage: device found at 7
usb-storage: waiting for device to settle before scanning
usb-storage: device scan complete
scsi 2:0:0:0: Direct-Access     Generic                   6000 PQ: 0 ANSI: 0 CCS
sd 2:0:0:0: Attached scsi generic sg2 type 0
sd 2:0:0:0: [sdb] 990976 512-byte hardware sectors: (507 MB/483 MiB)
sd 2:0:0:0: [sdb] Write Protect is off
sd 2:0:0:0: [sdb] Mode Sense: 4b 00 00 08
sd 2:0:0:0: [sdb] Assuming drive cache: write through
sd 2:0:0:0: [sdb] Assuming drive cache: write through
 sdb:<6>sd 2:0:0:0: [sdb] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
sd 2:0:0:0: [sdb] Sense Key : Illegal Request [current] 
sd 2:0:0:0: [sdb] Add. Sense: Logical block address out of range
end_request: I/O error, dev sdb, sector 0
Buffer I/O error on device sdb, logical block 0
Dev sdb: unable to read RDB block 0
 unable to read partition table
sd 2:0:0:0: [sdb] Attached SCSI removable disk
usb 1-3: USB disconnect, address 7

parted seems to display both partitions just fine,
and that other OS does not seem to have any trouble
accessing the disk.

The message 'unable to read RDB block' seems to come from
fs/partitions/amiga.c which looks pretty weird.

Any idea what info would be helpful in debugging this?
Just to clarify, this is not a regression - older linux versions
as far back as 2.6.24 seem to behave the same way.


-- 
MST