github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-06 21:58:01 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

scsi: st: Record the tape position after a successful MTLOAD

Browse Source 
Commit 0b120edb37 ("scsi: st: Add MTIOCGET and MTLOAD to ioctls allowed
after device reset") allows MTLOAD to clear the reset condition because the
tape location is known after MTLOAD.  But the driver does not record it:
reset_state() sets the file and block numbers to -1, and do_load_unload()
leaves them there.  check_tape() sets them to 0 only for a new session,
which requires a new-medium unit attention.  Drives that do not report one
when the medium was already loaded (seen with IBM LTO drives) keep
reporting file/block -1 in MTIOCGET and no BOT, although the tape is at the
beginning.

After a successful load, reset the partition and the state of all
partitions, as the new-session path in check_tape() does: partition 0,
position at BOT, EOF state cleared and no pending write.  Otherwise the
driver may still record the previous partition, so that a later MTSETPART
to that partition is not performed; a read after loading at EOD fails with
EIO; and a partition left in the ST_WRITING state by a partition switch in
read() or write() makes st_flush() write a filemark at the beginning of
partition 0 when the device is closed.

Fixes: 0b120edb37 ("scsi: st: Add MTIOCGET and MTLOAD to ioctls allowed after device reset")
Suggested-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
Assisted-by: Claude sashiko
Signed-off-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Link: https://patch.msgid.link/20260929192821.997675-3-loberman@redhat.com
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>
This commit is contained in:
Laurence Oberman 2026-09-29 15:28:19 -04:00 committed by Martin K. Petersen (Oracle)
parent 8d1cc28519
commit 54ee0ee9bd
1 changed files with 24 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
drivers/scsi/st.c
View File

@ -2686,6 +2686,30 @@ static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_cod
else {
STp->rew_at_close = STp->autorew_dev;
retval = check_tape(STp, filp);
/*
* LOAD leaves the medium at the beginning of partition
* 0. check_tape() records that only for a new session;
* without a new-medium unit attention (the medium was
* already loaded) the partition and the partition state
* would be left as before the load. Reset them as a
* new session does, for all partitions: a stale
* ST_WRITING state would make st_flush() write a
* filemark at the beginning of partition 0.
*/
if (retval == CHKRES_READY) {
int i;
STp->partition = STp->new_partition = 0;
for (i = 0; i < ST_NBR_PARTITIONS; i++) {
STps = &(STp->ps[i]);
STps->rw = ST_IDLE;
STps->eof = ST_NOEOF;
STps->at_sm = 0;
STps->last_block_valid = 0;
STps->drv_block = 0;
STps->drv_file = 0;
}
}
if (retval > 0)
retval = 0;
}