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

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

On Tue, May 26, 2009 at 07:03:43PM +0300, Michael S. Tsirkin wrote:
> On Tue, May 26, 2009 at 10:04:01AM -0400, Alan Stern wrote:
> > On Tue, 26 May 2009, Michael S. Tsirkin wrote:
> > 
> > > On Mon, May 25, 2009 at 05:08:12PM -0400, Alan Stern wrote:
> > > > On Mon, 25 May 2009, Michael S. Tsirkin wrote:
> > > > 
> > > > > > So apparently this is a bug in the device; it doesn't respond correctly
> > > > > > to the first READ command.  But since it does respond correctly to 
> > > > > > later commands, everything works okay thereafter.  You ought to be able 
> > > > > > to recover from the error by running
> > > > > > 
> > > > > > 	blockdev --rereadpt /dev/sdb
> > > > > > 
> > > > > > manually.
> > > > > 
> > > > > Yes, this helps.
> > > > > Would it make sense for kernel to retry automatically?
> > > > > Why doesn't it?
> > > > 
> > > > I don't know the details in this case.  Most likely the error code 
> > > > (Logical Block Address Out of Range) is interpreted as a fatal 
> > > > non-retryable error.  For other sorts of errors, the kernel does retry.
> > > 
> > > Who would know? The scsi crowd?
> > 
> > They would know.  But it's easy enough to find out.  (Looks through 
> > the SCSI code...)  Here we go.  scsi_io_completion() contains this:
> > 
> > 		case ILLEGAL_REQUEST:
> > 			/* If we had an ILLEGAL REQUEST returned, then
> > 			 * we may have performed an unsupported
> > 			 * command.  The only thing this should be
> > 			 * would be a ten byte read where only a six
> > 			 * byte read was supported.  Also, on a system
> > 			 * where READ CAPACITY failed, we may have
> > 			 * read past the end of the disk.
> > 			 */
> > 			if ((cmd->device->use_10_for_rw &&
> > 			    sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
> > 			    (cmd->cmnd[0] == READ_10 ||
> > 			     cmd->cmnd[0] == WRITE_10)) {
> > 				/* This will issue a new 6-byte command. */
> > 				cmd->device->use_10_for_rw = 0;
> > 				action = ACTION_REPREP;
> > 			} else if (sshdr.asc == 0x10) /* DIX */ {
> > 				description = "Host Data Integrity Failure";
> > 				action = ACTION_FAIL;
> > 				error = -EILSEQ;
> > 			} else
> > 				action = ACTION_FAIL;
> > 			break;
> 
> Which kernel version is this? I see different code in 2.6.30-rc7.

Sorry, looked at the wrong file.
I see this in drivers/scsi/scsi_lib.c

-- 
MST