scsi: st: Modify st.c to use the new scsi_error counters

Compare the stored values of por_ctr and new_media_ctr against the values
in the device struct. In case of mismatch, the Unit Attention corresponding
to the counter has happened.  This is a safeguard against another ULD
catching the Unit Attention sense data.

Macros scsi_get_ua_new_media_ctr and scsi_get_ua_por_ctr are added to read
the current values of the counters.

Signed-off-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
Link: https://lore.kernel.org/r/20250120194925.44432-4-Kai.Makisara@kolumbus.fi
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: John Meneghini <jmeneghi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
pull/1188/head
Kai Mäkisara 2025-01-20 21:49:24 +02:00 committed by Martin K. Petersen
parent a5d518cd4e
commit 341128dfe1
3 changed files with 35 additions and 5 deletions

View File

@ -163,9 +163,11 @@ static const char *st_formats[] = {
static int debugging = DEBUG;
/* Setting these non-zero may risk recognizing resets */
#define MAX_RETRIES 0
#define MAX_WRITE_RETRIES 0
#define MAX_READY_RETRIES 0
#define NO_TAPE NOT_READY
#define ST_TIMEOUT (900 * HZ)
@ -357,10 +359,18 @@ static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
{
int result = SRpnt->result;
u8 scode;
unsigned int ctr;
DEB(const char *stp;)
char *name = STp->name;
struct st_cmdstatus *cmdstatp;
ctr = scsi_get_ua_por_ctr(STp->device);
if (ctr != STp->por_ctr) {
STp->por_ctr = ctr;
STp->pos_unknown = 1; /* ASC => power on / reset */
st_printk(KERN_WARNING, STp, "Power on/reset recognized.");
}
if (!result)
return 0;
@ -413,10 +423,11 @@ static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
if (cmdstatp->have_sense &&
cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
if (cmdstatp->have_sense && scode == UNIT_ATTENTION && cmdstatp->sense_hdr.asc == 0x29)
if (cmdstatp->have_sense && scode == UNIT_ATTENTION &&
cmdstatp->sense_hdr.asc == 0x29 && !STp->pos_unknown) {
STp->pos_unknown = 1; /* ASC => power on / reset */
STp->pos_unknown |= STp->device->was_reset;
st_printk(KERN_WARNING, STp, "Power on/reset recognized.");
}
if (cmdstatp->have_sense &&
scode == RECOVERED_ERROR
@ -968,6 +979,7 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
{
int attentions, waits, max_wait, scode;
int retval = CHKRES_READY, new_session = 0;
unsigned int ctr;
unsigned char cmd[MAX_COMMAND_SIZE];
struct st_request *SRpnt = NULL;
struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
@ -1024,6 +1036,13 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
}
}
ctr = scsi_get_ua_new_media_ctr(STp->device);
if (ctr != STp->new_media_ctr) {
STp->new_media_ctr = ctr;
new_session = 1;
DEBC_printk(STp, "New tape session.");
}
retval = (STp->buffer)->syscall_result;
if (!retval)
retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
@ -3639,8 +3658,6 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
goto out;
}
reset_state(STp); /* Clears pos_unknown */
/* remove this when the midlevel properly clears was_reset */
STp->device->was_reset = 0;
/* Fix the device settings after reset, ignore errors */
if (mtc.mt_op == MTREW || mtc.mt_op == MTSEEK ||
@ -4402,6 +4419,9 @@ static int st_probe(struct device *dev)
goto out_idr_remove;
}
tpnt->new_media_ctr = scsi_get_ua_new_media_ctr(SDp);
tpnt->por_ctr = scsi_get_ua_por_ctr(SDp);
dev_set_drvdata(dev, tpnt);

View File

@ -179,6 +179,10 @@ struct scsi_tape {
int recover_count; /* From tape opening */
int recover_reg; /* From last status call */
/* The saved values of midlevel counters */
unsigned int new_media_ctr;
unsigned int por_ctr;
#if DEBUG
unsigned char write_pending;
int nbr_finished;

View File

@ -687,6 +687,12 @@ static inline int scsi_device_busy(struct scsi_device *sdev)
return sbitmap_weight(&sdev->budget_map);
}
/* Macros to access the UNIT ATTENTION counters */
#define scsi_get_ua_new_media_ctr(sdev) \
((const unsigned int)(sdev->ua_new_media_ctr))
#define scsi_get_ua_por_ctr(sdev) \
((const unsigned int)(sdev->ua_por_ctr))
#define MODULE_ALIAS_SCSI_DEVICE(type) \
MODULE_ALIAS("scsi:t-" __stringify(type) "*")
#define SCSI_DEVICE_MODALIAS_FMT "scsi:t-0x%02x"