s390/dasd: Handle out-of-space constraint

The storage server issues three different types of out-of-space messages
whenever the Extent Pool or Extent Repository space runs short. When a
configured warning watermark is reached, the physical space is
completeley exhausted, or the capacity constraints have been relieved, a
message is received.

A log entry for the sysadmin to react to is generated in any case. In
case the physical space is completely exhausted, sense data that reads
"no space left on device" is received. In this case, currently running
I/O will be blocked until space has either been released or added to the
extent pool, and a relieve message was received via an attention
interrupt.

Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 57 insertions, 1 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index ae460543f59db..6cca72782af6a 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1659,6 +1659,14 @@ static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
 		scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
 }
 
+static int dasd_ese_oos_cond(u8 *sense)
+{
+	return sense[0] & SNS0_EQUIPMENT_CHECK &&
+		sense[1] & SNS1_PERM_ERR &&
+		sense[1] & SNS1_WRITE_INHIBITED &&
+		sense[25] == 0x01;
+}
+
 /*
  * Interrupt handler for "normal" ssch-io based dasd devices.
  */
@@ -1727,6 +1735,17 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 				test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
 			nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
 				test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
+
+			/*
+			 * Extent pool probably out-of-space.
+			 * Stop device and check exhaust level.
+			 */
+			if (dasd_ese_oos_cond(sense)) {
+				dasd_generic_space_exhaust(device, cqr);
+				device->discipline->ext_pool_exhaust(device, cqr);
+				dasd_put_device(device);
+				return;
+			}
 		}
 		if (!(fp_suppressed || nrf_suppressed))
 			device->discipline->dump_sense_dbf(device, irb, "int");
@@ -2021,7 +2040,7 @@ static void __dasd_device_check_expire(struct dasd_device *device)
 static int __dasd_device_is_unusable(struct dasd_device *device,
 				     struct dasd_ccw_req *cqr)
 {
-	int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
+	int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM | DASD_STOPPED_NOSPC);
 
 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
 	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
@@ -3877,6 +3896,43 @@ int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
 }
 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
 
+void dasd_generic_space_exhaust(struct dasd_device *device,
+				struct dasd_ccw_req *cqr)
+{
+	dasd_eer_write(device, NULL, DASD_EER_NOSPC);
+
+	if (device->state < DASD_STATE_BASIC)
+		return;
+
+	if (cqr->status == DASD_CQR_IN_IO ||
+	    cqr->status == DASD_CQR_CLEAR_PENDING) {
+		cqr->status = DASD_CQR_QUEUED;
+		cqr->retries++;
+	}
+	dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
+	dasd_device_clear_timer(device);
+	dasd_schedule_device_bh(device);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
+
+void dasd_generic_space_avail(struct dasd_device *device)
+{
+	dev_info(&device->cdev->dev, "Extent pool space is available\n");
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
+
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
+	dasd_schedule_device_bh(device);
+
+	if (device->block) {
+		dasd_schedule_block_bh(device->block);
+		if (device->block->request_queue)
+			blk_mq_run_hw_queues(device->block->request_queue, true);
+	}
+	if (!device->stopped)
+		wake_up(&generic_waitq);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
+
 /*
  * clear active requests and requeue them to block layer if possible
  */