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, 157 insertions, 2 deletions

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 7f7429a99a67..fc53e1e221f0 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -89,6 +89,19 @@ static struct {
 } *dasd_reserve_req;
 static DEFINE_MUTEX(dasd_reserve_mutex);
 
+static struct {
+	struct dasd_ccw_req cqr;
+	struct ccw1 ccw[2];
+	char data[40];
+} *dasd_vol_info_req;
+static DEFINE_MUTEX(dasd_vol_info_mutex);
+
+struct ext_pool_exhaust_work_data {
+	struct work_struct worker;
+	struct dasd_device *device;
+	struct dasd_device *base;
+};
+
 /* definitions for the path verification worker */
 struct path_verification_work_data {
 	struct work_struct worker;
@@ -1479,6 +1492,7 @@ static int dasd_eckd_read_vol_info(struct dasd_device *device)
 	struct dasd_rssd_vsq *vsq;
 	struct dasd_ccw_req *cqr;
 	struct ccw1 *ccw;
+	int useglobal;
 	int rc;
 
 	/* This command cannot be executed on an alias device */
@@ -1486,12 +1500,20 @@ static int dasd_eckd_read_vol_info(struct dasd_device *device)
 	    private->uid.type == UA_HYPER_PAV_ALIAS)
 		return 0;
 
+	useglobal = 0;
 	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2 /* PSF + RSSD */,
 				   sizeof(*prssdp) + sizeof(*vsq), device, NULL);
 	if (IS_ERR(cqr)) {
 		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
 				"Could not allocate initialization request");
-		return PTR_ERR(cqr);
+		mutex_lock(&dasd_vol_info_mutex);
+		useglobal = 1;
+		cqr = &dasd_vol_info_req->cqr;
+		memset(cqr, 0, sizeof(*cqr));
+		memset(dasd_vol_info_req, 0, sizeof(*dasd_vol_info_req));
+		cqr->cpaddr = &dasd_vol_info_req->ccw;
+		cqr->data = &dasd_vol_info_req->data;
+		cqr->magic = DASD_ECKD_MAGIC;
 	}
 
 	/* Prepare for Read Subsystem Data */
@@ -1535,7 +1557,10 @@ static int dasd_eckd_read_vol_info(struct dasd_device *device)
 			 "Reading the volume storage information failed with rc=%d\n", rc);
 	}
 
-	dasd_sfree_request(cqr, cqr->memdev);
+	if (useglobal)
+		mutex_unlock(&dasd_vol_info_mutex);
+	else
+		dasd_sfree_request(cqr, cqr->memdev);
 
 	return rc;
 }
@@ -1590,6 +1615,53 @@ static int dasd_eckd_logical_capacity(struct dasd_device *device)
 	return private->vsq.logical_capacity;
 }
 
+static void dasd_eckd_ext_pool_exhaust_work(struct work_struct *work)
+{
+	struct ext_pool_exhaust_work_data *data;
+	struct dasd_device *device;
+	struct dasd_device *base;
+
+	data = container_of(work, struct ext_pool_exhaust_work_data, worker);
+	device = data->device;
+	base = data->base;
+
+	if (!base)
+		base = device;
+	if (dasd_eckd_space_configured(base) != 0) {
+		dasd_generic_space_avail(device);
+	} else {
+		dev_warn(&device->cdev->dev, "No space left in the extent pool\n");
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s", "out of space");
+	}
+
+	dasd_put_device(device);
+	kfree(data);
+}
+
+static int dasd_eckd_ext_pool_exhaust(struct dasd_device *device,
+				      struct dasd_ccw_req *cqr)
+{
+	struct ext_pool_exhaust_work_data *data;
+
+	data = kzalloc(sizeof(*data), GFP_ATOMIC);
+	if (!data)
+		return -ENOMEM;
+	INIT_WORK(&data->worker, dasd_eckd_ext_pool_exhaust_work);
+	dasd_get_device(device);
+	data->device = device;
+
+	if (cqr->block)
+		data->base = cqr->block->base;
+	else if (cqr->basedev)
+		data->base = cqr->basedev;
+	else
+		data->base = NULL;
+
+	schedule_work(&data->worker);
+
+	return 0;
+}
+
 static void dasd_eckd_cpy_ext_pool_data(struct dasd_device *device,
 					struct dasd_rssd_lcq *lcq)
 {
@@ -2099,6 +2171,9 @@ dasd_eckd_analysis_ccw(struct dasd_device *device)
 	cqr->retries = 255;
 	cqr->buildclk = get_tod_clock();
 	cqr->status = DASD_CQR_FILLED;
+	/* Set flags to suppress output for expected errors */
+	set_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
+
 	return cqr;
 }
 
@@ -6267,6 +6342,73 @@ static void dasd_eckd_handle_cuir(struct dasd_device *device, void *messages,
 	device->discipline->check_attention(device, lpum);
 }
 
+static void dasd_eckd_oos_resume(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct alias_pav_group *pavgroup, *tempgroup;
+	struct dasd_device *dev, *n;
+	unsigned long flags;
+
+	spin_lock_irqsave(&private->lcu->lock, flags);
+	list_for_each_entry_safe(dev, n, &private->lcu->active_devices,
+				 alias_list) {
+		if (dev->stopped & DASD_STOPPED_NOSPC)
+			dasd_generic_space_avail(dev);
+	}
+	list_for_each_entry_safe(dev, n, &private->lcu->inactive_devices,
+				 alias_list) {
+		if (dev->stopped & DASD_STOPPED_NOSPC)
+			dasd_generic_space_avail(dev);
+	}
+	/* devices in PAV groups */
+	list_for_each_entry_safe(pavgroup, tempgroup,
+				 &private->lcu->grouplist,
+				 group) {
+		list_for_each_entry_safe(dev, n, &pavgroup->baselist,
+					 alias_list) {
+			if (dev->stopped & DASD_STOPPED_NOSPC)
+				dasd_generic_space_avail(dev);
+		}
+		list_for_each_entry_safe(dev, n, &pavgroup->aliaslist,
+					 alias_list) {
+			if (dev->stopped & DASD_STOPPED_NOSPC)
+				dasd_generic_space_avail(dev);
+		}
+	}
+	spin_unlock_irqrestore(&private->lcu->lock, flags);
+}
+
+static void dasd_eckd_handle_oos(struct dasd_device *device, void *messages,
+				 __u8 lpum)
+{
+	struct dasd_oos_message *oos = messages;
+
+	switch (oos->code) {
+	case REPO_WARN:
+	case POOL_WARN:
+		dev_warn(&device->cdev->dev,
+			 "Extent pool usage has reached a critical value\n");
+		dasd_eckd_oos_resume(device);
+		break;
+	case REPO_EXHAUST:
+	case POOL_EXHAUST:
+		dev_warn(&device->cdev->dev,
+			 "Extent pool is exhausted\n");
+		break;
+	case REPO_RELIEVE:
+	case POOL_RELIEVE:
+		dev_info(&device->cdev->dev,
+			 "Extent pool physical space constraint has been relieved\n");
+		break;
+	}
+
+	/* In any case, update related data */
+	dasd_eckd_read_ext_pool_info(device);
+
+	/* to make sure there is no attention left schedule work again */
+	device->discipline->check_attention(device, lpum);
+}
+
 static void dasd_eckd_check_attention_work(struct work_struct *work)
 {
 	struct check_attention_work_data *data;
@@ -6285,9 +6427,14 @@ static void dasd_eckd_check_attention_work(struct work_struct *work)
 	rc = dasd_eckd_read_message_buffer(device, messages, data->lpum);
 	if (rc)
 		goto out;
+
 	if (messages->length == ATTENTION_LENGTH_CUIR &&
 	    messages->format == ATTENTION_FORMAT_CUIR)
 		dasd_eckd_handle_cuir(device, messages, data->lpum);
+	if (messages->length == ATTENTION_LENGTH_OOS &&
+	    messages->format == ATTENTION_FORMAT_OOS)
+		dasd_eckd_handle_oos(device, messages, data->lpum);
+
 out:
 	dasd_put_device(device);
 	kfree(messages);
@@ -6501,6 +6648,7 @@ static struct dasd_discipline dasd_eckd_discipline = {
 	.ext_pool_cap_at_warnlevel = dasd_eckd_ext_pool_cap_at_warnlevel,
 	.ext_pool_warn_thrshld = dasd_eckd_ext_pool_warn_thrshld,
 	.ext_pool_oos = dasd_eckd_ext_pool_oos,
+	.ext_pool_exhaust = dasd_eckd_ext_pool_exhaust,
 	.ese_format = dasd_eckd_ese_format,
 	.ese_read = dasd_eckd_ese_read,
 };
@@ -6515,16 +6663,22 @@ dasd_eckd_init(void)
 				   GFP_KERNEL | GFP_DMA);
 	if (!dasd_reserve_req)
 		return -ENOMEM;
+	dasd_vol_info_req = kmalloc(sizeof(*dasd_vol_info_req),
+				    GFP_KERNEL | GFP_DMA);
+	if (!dasd_vol_info_req)
+		return -ENOMEM;
 	path_verification_worker = kmalloc(sizeof(*path_verification_worker),
 				   GFP_KERNEL | GFP_DMA);
 	if (!path_verification_worker) {
 		kfree(dasd_reserve_req);
+		kfree(dasd_vol_info_req);
 		return -ENOMEM;
 	}
 	rawpadpage = (void *)__get_free_page(GFP_KERNEL);
 	if (!rawpadpage) {
 		kfree(path_verification_worker);
 		kfree(dasd_reserve_req);
+		kfree(dasd_vol_info_req);
 		return -ENOMEM;
 	}
 	ret = ccw_driver_register(&dasd_eckd_driver);
@@ -6533,6 +6687,7 @@ dasd_eckd_init(void)
 	else {
 		kfree(path_verification_worker);
 		kfree(dasd_reserve_req);
+		kfree(dasd_vol_info_req);
 		free_page((unsigned long)rawpadpage);
 	}
 	return ret;