[1824] in linux-scsi channel archive
Incorrect block number returned by MTIOCGET?
daemon@ATHENA.MIT.EDU (Jan Echternach)
Wed May 7 12:20:44 1997
Date: Wed, 7 May 1997 14:14:05 +0200
From: Jan Echternach <echter@informatik.uni-rostock.de>
To: linux-scsi@vger.rutgers.edu
Reply-To: Jan Echternach <jan.echternach@informatik.uni-rostock.de>
Hi,
When I was tracking down a problem with taper (seeking didn't work
somehow), I found out that MTIOCGET can return a block number that
seems incorrect to me:
1. open rewinding device
2. write some data, write filemark, write more data
3. close
4. open non-rewinding device
3. seek to filemark
4. close
5. open rewinding device
6. MTIOCPOS -> block 12
7. MTIOCGET -> block 0 (Is this correct?)
Now something different: When I was browsing through st.c, I found
this code:
> scsi_tape_open():
> if ((STp->buffer)->last_result_fatal != 0) {
> if ((SCpnt->sense_buffer[0] & 0x70) == 0x70 &&
> (SCpnt->sense_buffer[2] & 0x0f) == NO_TAPE) {
> (STp->mt_status)->mt_fileno = STp->drv_block = 0 ;
> STp->ready = ST_NO_TAPE;
> } else {
> (STp->mt_status)->mt_fileno = STp->drv_block = (-1);
> STp->ready = ST_NOT_READY;
> }
> SCpnt->request.rq_status = RQ_INACTIVE; /* Mark as not busy */
> STp->density = 0; /* Clear the erroneous "residue" */
> STp->write_prot = 0;
> STp->block_size = 0;
> STp->eof = ST_NOEOF;
> (STp->mt_status)->mt_fileno = STp->drv_block = 0;
> STp->partition = STp->new_partition = 0;
> STp->door_locked = ST_UNLOCKED;
> STp->in_use = 1;
> return 0;
> }
It looks like this:
if (c1) {
if (c2) {
drv_block = 0;
...
} else {
drv_block = -1;
...
}
...
drv_block = 0;
...
}
Is this a bug?
System:
Linux-2.0.30
Buslogic BT-948
SDT-7000 DDS-2 DAT drive, SCSI-2
--
Jan
