scsi: scsi_debug: Fix request sense

The SCSI REQUEST SENSE command emulation was found to be broken.  It is a
quite complex command so try and make it do a subset of what it should
do. Remove the attempt to mimic SCSI-1 REQUEST SENSE (i.e. return the sense
data for the previous failed command). Add some reporting of "pollable"
sense data [see spc6r02: 5.12.2]. Keep the IEC mode page MRIE=6 TEST=1
predictive failure reporting.

Link: https://lore.kernel.org/r/20200723194819.545573-1-dgilbert@interlog.com
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Douglas Gilbert 2020-07-23 15:48:19 -04:00 committed by Martin K. Petersen
parent 02e3e588f0
commit 84905d34f1

View file

@ -1712,68 +1712,62 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
return ret;
}
/* See resp_iec_m_pg() for how this data is manipulated */
static unsigned char iec_m_pg[] = {0x1c, 0xa, 0x08, 0, 0, 0, 0, 0,
0, 0, 0x0, 0x0};
static int resp_requests(struct scsi_cmnd *scp,
struct sdebug_dev_info *devip)
{
unsigned char *sbuff;
unsigned char *cmd = scp->cmnd;
unsigned char arr[SCSI_SENSE_BUFFERSIZE];
bool dsense;
unsigned char arr[SCSI_SENSE_BUFFERSIZE]; /* assume >= 18 bytes */
bool dsense = !!(cmd[1] & 1);
int alloc_len = cmd[4];
int len = 18;
int stopped_state = atomic_read(&devip->stopped);
memset(arr, 0, sizeof(arr));
dsense = !!(cmd[1] & 1);
sbuff = scp->sense_buffer;
if ((iec_m_pg[2] & 0x4) && (6 == (iec_m_pg[3] & 0xf))) {
if (stopped_state > 0) { /* some "pollable" data [spc6r02: 5.12.2] */
if (dsense) {
arr[0] = 0x72;
arr[1] = NOT_READY;
arr[2] = LOGICAL_UNIT_NOT_READY;
arr[3] = (stopped_state == 2) ? 0x1 : 0x2;
len = 8;
} else {
arr[0] = 0x70;
arr[2] = NOT_READY; /* NO_SENSE in sense_key */
arr[7] = 0xa; /* 18 byte sense buffer */
arr[12] = LOGICAL_UNIT_NOT_READY;
arr[13] = (stopped_state == 2) ? 0x1 : 0x2;
}
} else if ((iec_m_pg[2] & 0x4) && (6 == (iec_m_pg[3] & 0xf))) {
/* Information exceptions control mode page: TEST=1, MRIE=6 */
if (dsense) {
arr[0] = 0x72;
arr[1] = 0x0; /* NO_SENSE in sense_key */
arr[2] = THRESHOLD_EXCEEDED;
arr[3] = 0xff; /* TEST set and MRIE==6 */
arr[3] = 0xff; /* Failure prediction(false) */
len = 8;
} else {
arr[0] = 0x70;
arr[2] = 0x0; /* NO_SENSE in sense_key */
arr[7] = 0xa; /* 18 byte sense buffer */
arr[12] = THRESHOLD_EXCEEDED;
arr[13] = 0xff; /* TEST set and MRIE==6 */
arr[13] = 0xff; /* Failure prediction(false) */
}
} else {
memcpy(arr, sbuff, SCSI_SENSE_BUFFERSIZE);
if (arr[0] >= 0x70 && dsense == sdebug_dsense)
; /* have sense and formats match */
else if (arr[0] <= 0x70) {
if (dsense) {
memset(arr, 0, 8);
arr[0] = 0x72;
len = 8;
} else {
memset(arr, 0, 18);
arr[0] = 0x70;
arr[7] = 0xa;
}
} else if (dsense) {
memset(arr, 0, 8);
arr[0] = 0x72;
arr[1] = sbuff[2]; /* sense key */
arr[2] = sbuff[12]; /* asc */
arr[3] = sbuff[13]; /* ascq */
} else { /* nothing to report */
if (dsense) {
len = 8;
memset(arr, 0, len);
arr[0] = 0x72;
} else {
memset(arr, 0, 18);
memset(arr, 0, len);
arr[0] = 0x70;
arr[2] = sbuff[1];
arr[7] = 0xa;
arr[12] = sbuff[1];
arr[13] = sbuff[3];
}
}
mk_sense_buffer(scp, 0, NO_ADDITIONAL_SENSE, 0);
return fill_from_dev_buffer(scp, arr, len);
return fill_from_dev_buffer(scp, arr, min_t(int, len, alloc_len));
}
static int resp_start_stop(struct scsi_cmnd *scp,