From: "Ewan D. Milne" <emilne@xxxxxxxxxx>
Generate a REPORTED LUNS DATA HAS CHANGED Unit Attention if
sysfs "max_luns" is used to change the number of scsi_debug LUNs.
This is only done if scsi_debug_scsi_level is SPC-3 or above.
Additionally, implement SPC-4 behavior which only generates
this Unit Attention on the first LUN on the target to receive
a command after the change. This condition is cleared when
a REPORT LUNS command is received.
Signed-off-by: Ewan D. Milne <emilne@xxxxxxxxxx>
---
drivers/scsi/scsi_debug.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 55 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 1a11466..648abf2 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -80,6 +80,8 @@ static const char *scsi_debug_version_date = "20141022";
#define INVALID_FIELD_IN_PARAM_LIST 0x26
#define UA_RESET_ASC 0x29
#define UA_CHANGED_ASC 0x2a
+#define TARGET_CHANGED_ASC 0x3f
+#define LUNS_CHANGED_ASCQ 0x0e
#define INSUFF_RES_ASC 0x55
#define INSUFF_RES_ASCQ 0x3
#define POWER_ON_RESET_ASCQ 0x0
@@ -181,7 +183,8 @@ static const char *scsi_debug_version_date = "20141022";
#define SDEBUG_UA_BUS_RESET 1
#define SDEBUG_UA_MODE_CHANGED 2
#define SDEBUG_UA_CAPACITY_CHANGED 3
-#define SDEBUG_NUM_UAS 4
+#define SDEBUG_UA_LUNS_CHANGED 4
+#define SDEBUG_NUM_UAS 5
/* for check_readiness() */
#define UAS_ONLY 1 /* check for UAs only */
@@ -783,6 +786,22 @@ static int scsi_debug_ioctl(struct scsi_device *dev, int cmd, void __user *arg)
/* return -ENOTTY; // correct return but upsets fdisk */
}
+static int clear_luns_changed_on_target(struct sdebug_dev_info *devip)
+{
+ struct sdebug_host_info *sdhp;
+ struct sdebug_dev_info *dp;
+
+ spin_lock(&sdebug_host_list_lock);
+ list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
+ list_for_each_entry(dp, &sdhp->dev_info_list, dev_list) {
+ if ((devip->sdbg_host == dp->sdbg_host) &&
+ (devip->target == dp->target))
+ clear_bit(SDEBUG_UA_LUNS_CHANGED, dp->uas_bm);
+ }
+ }
+ spin_unlock(&sdebug_host_list_lock);
+}
+
static int check_readiness(struct scsi_cmnd *SCpnt, int uas_only,
struct sdebug_dev_info * devip)
{
@@ -818,6 +837,23 @@ static int check_readiness(struct scsi_cmnd *SCpnt, int uas_only,
if (debug)
cp = "capacity data changed";
break;
+ case SDEBUG_UA_LUNS_CHANGED:
+ /*
+ * SPC-3 behavior is to report a UNIT ATTENTION with
+ * ASC/ASCQ REPORTED LUNS DATA HAS CHANGED on every LUN
+ * on the target, until a REPORT LUNS command is
+ * received. SPC-4 behavior is to report it only once.
+ * NOTE: scsi_debug_scsi_level does not use the same
+ * values as struct scsi_device->scsi_level.
+ */
+ if (scsi_debug_scsi_level >= 6) /* SPC-4 and above */
+ clear_luns_changed_on_target(devip);
+ mk_sense_buffer(SCpnt, UNIT_ATTENTION,
+ TARGET_CHANGED_ASC,
+ LUNS_CHANGED_ASCQ);
+ if (debug)
+ cp = "reported luns data has changed";
+ break;
default:
pr_warn("%s: unexpected unit attention code=%d\n",
__func__, k);
@@ -3229,6 +3265,7 @@ static int resp_report_luns(struct scsi_cmnd * scp,
unsigned char arr[SDEBUG_RLUN_ARR_SZ];
unsigned char * max_addr;
+ clear_luns_changed_on_target(devip);
alloc_len = cmd[9] + (cmd[8] << 8) + (cmd[7] << 16) + (cmd[6] << 24);
shortish = (alloc_len < 4);
if (shortish || (select_report > 2)) {
@@ -4369,10 +4406,27 @@ static ssize_t max_luns_store(struct device_driver *ddp, const char *buf,
size_t count)
{
int n;
+ bool changed;
if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
+ changed = (scsi_debug_max_luns != n);
scsi_debug_max_luns = n;
sdebug_max_tgts_luns();
+ if (changed && (scsi_debug_scsi_level >= 5)) { /* >= SPC-3 */
+ struct sdebug_host_info *sdhp;
+ struct sdebug_dev_info *dp;
+
+ spin_lock(&sdebug_host_list_lock);
+ list_for_each_entry(sdhp, &sdebug_host_list,
+ host_list) {
+ list_for_each_entry(dp, &sdhp->dev_info_list,
+ dev_list) {
+ set_bit(SDEBUG_UA_LUNS_CHANGED,
+ dp->uas_bm);
+ }
+ }
+ spin_unlock(&sdebug_host_list_lock);
+ }
return count;
}
return -EINVAL;
--
1.7.11.7
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