scst: improve thin provisioning support

This patch adds gen_tp_soft_threshold_reached_UA attribute for thin
provisioned devices that allows to generate THIN PROVISIONING SOFT
THRESHOLD REACHED Unit Attention.



git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7071 d57e44dd-8a1f-0410-8b47-8ef2f437770f

scst/README

@@ -1246,6 +1246,11 @@ Each vdisk_fileio's device has the following attributes in
  - thin_provisioned - contains thin provisioning status of this virtual
    device.
 
+ - gen_tp_soft_threshold_reached_UA - for thin provisioned devices
+   writing of anything into this write-only attribute will generate THIN
+   PROVISIONING SOFT THRESHOLD REACHED Unit Attention to all connected
+   to this device initiators.
+
  - removable - contains removable status of this virtual device.
 
  - rotational - contains rotational status of this virtual device.
@@ -1347,8 +1352,9 @@ For example:
 Each vdisk_blockio's device has the following attributes in
 /sys/kernel/scst_tgt/devices/device_name: blocksize, filename, nv_cache,
 read_only, removable, resync_size, rotational, size_mb, t10_dev_id,
-thin_provisioned, threads_num, threads_pool_type, tst, type, usn. See
-above description of those parameters.
+thin_provisioned, gen_tp_soft_threshold_reached_UA, threads_num,
+threads_pool_type, tst, type, usn. See above description of those
+parameters.
 
 Each vdisk_nullio's device has the following attributes in
 /sys/kernel/scst_tgt/devices/device_name: blocksize, read_only,

scst/README_in-tree

@@ -1106,6 +1106,11 @@ Each vdisk_fileio's device has the following attributes in
  - thin_provisioned - contains thin provisioning status of this virtual
    device.
 
+ - gen_tp_soft_threshold_reached_UA - for thin provisioned devices
+   writing of anything into this write-only attribute will generate THIN
+   PROVISIONING SOFT THRESHOLD REACHED Unit Attention to all connected
+   to this device initiators.
+
  - removable - contains removable status of this virtual device.
 
  - rotational - contains rotational status of this virtual device.
@@ -1205,8 +1210,9 @@ For example:
 Each vdisk_blockio's device has the following attributes in
 /sys/kernel/scst_tgt/devices/device_name: blocksize, filename, nv_cache,
 read_only, removable, resync_size, rotational, size_mb, t10_dev_id,
-thin_provisioned, threads_num, threads_pool_type, tst, type, usn. See
-above description of those parameters.
+thin_provisioned, gen_tp_soft_threshold_reached_UA, threads_num,
+threads_pool_type, tst, type, usn. See above description of those
+parameters.
 
 Each vdisk_nullio's device has the following attributes in
 /sys/kernel/scst_tgt/devices/device_name: blocksize, read_only,

scst/include/scst.h

@@ -5665,6 +5665,8 @@ void scst_path_put(struct nameidata *nd);
 #endif
 int scst_remove_file(const char *name);
 
+void scst_set_tp_soft_threshold_reached_UA(struct scst_tgt_dev *tgt_dev);
+
 int scst_pr_set_cluster_mode(struct scst_device *dev, bool cluster_mode,
 	const char *cl_dev_id);
 int scst_pr_init_dev(struct scst_device *dev);

scst/include/scst_const.h

@@ -337,11 +337,13 @@ static inline int scst_sense_response_code(const uint8_t *sense)
 #define scst_sense_asym_access_state_changed	UNIT_ATTENTION,  0x2A, 0x06
 #define scst_sense_capacity_data_changed	UNIT_ATTENTION,  0x2A, 0x9
 #define scst_sense_cleared_by_another_ini_UA	UNIT_ATTENTION,  0x2F, 0
+#define scst_sense_tp_soft_threshold_reached	UNIT_ATTENTION,  0x38, 0x7
 #define scst_sense_inquiry_data_changed		UNIT_ATTENTION,  0x3F, 0x3
 #define scst_sense_reported_luns_data_changed	UNIT_ATTENTION,  0x3F, 0xE
 
 /* DATA_PROTECT is 7 */
-#define scst_sense_data_protect			DATA_PROTECT,    0x27, 0
+#define scst_sense_data_protect			DATA_PROTECT,    0x00, 0
+#define scst_space_allocation_failed_write_protect DATA_PROTECT,    0x27, 7
 
 /* ABORTED_COMMAND is 0xb */
 #define scst_sense_aborted_command		ABORTED_COMMAND, 0x00, 0

scst/src/dev_handlers/scst_vdisk.c

@@ -399,6 +399,8 @@ static ssize_t vdisk_sysfs_wt_show(struct kobject *kobj,
 	struct kobj_attribute *attr, char *buf);
 static ssize_t vdisk_sysfs_tp_show(struct kobject *kobj,
 	struct kobj_attribute *attr, char *buf);
+static ssize_t vdisk_sysfs_gen_tp_soft_threshold_reached_UA(struct kobject *kobj,
+	struct kobj_attribute *attr, const char *buf, size_t count);
 static ssize_t vdisk_sysfs_tst_show(struct kobject *kobj,
 	struct kobj_attribute *attr, char *buf);
 static ssize_t vdisk_sysfs_rotational_show(struct kobject *kobj,
@@ -495,6 +497,9 @@ static struct kobj_attribute vdisk_wt_attr =
 	__ATTR(write_through, S_IRUGO, vdisk_sysfs_wt_show, NULL);
 static struct kobj_attribute vdisk_tp_attr =
 	__ATTR(thin_provisioned, S_IRUGO, vdisk_sysfs_tp_show, NULL);
+static struct kobj_attribute gen_tp_soft_threshold_reached_UA_attr =
+	__ATTR(gen_tp_soft_threshold_reached_UA, S_IWUSR, NULL,
+		vdisk_sysfs_gen_tp_soft_threshold_reached_UA);
 static struct kobj_attribute vdisk_tst_attr =
 	__ATTR(tst, S_IRUGO, vdisk_sysfs_tst_show, NULL);
 static struct kobj_attribute vdisk_rotational_attr =
@@ -1054,6 +1059,17 @@ check:
 
 	if (virt_dev->thin_provisioned) {
 		int block_shift = virt_dev->dev->block_shift;
+#ifndef CONFIG_SCST_PROC
+		int rc;
+
+		rc = sysfs_create_file(&virt_dev->dev->dev_kobj,
+				&gen_tp_soft_threshold_reached_UA_attr.attr);
+		if (rc != 0) {
+			PRINT_ERROR("Can't create attr %s for dev %s",
+				gen_tp_soft_threshold_reached_UA_attr.attr.name,
+				virt_dev->name);
+		}
+#endif
 
 		if (virt_dev->blockio) {
 			struct request_queue *q;
@@ -6362,10 +6378,13 @@ restart:
 				    full_len);
 			if (err == -EAGAIN)
 				scst_set_busy(cmd);
-			else {
+			else if (err == -ENOSPC) {
+				WARN_ON(!virt_dev->thin_provisioned);
+				scst_set_cmd_error(cmd,
+					SCST_LOAD_SENSE(scst_space_allocation_failed_write_protect));
+			} else
 				scst_set_cmd_error(cmd,
 				    SCST_LOAD_SENSE(scst_sense_write_error));
-			}
 			goto out_set_fs;
 		} else if (err < full_len) {
 			/*
@@ -6520,15 +6539,21 @@ static void blockio_endio(struct bio *bio)
 		spin_lock_irqsave(&vdev_err_lock, flags);
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
-		if (bio->bi_rw & (1 << BIO_RW))
+		if (bio->bi_rw & (1 << BIO_RW)) {
 #elif LINUX_VERSION_CODE < KERNEL_VERSION(4, 8, 0)
-		if (bio->bi_rw & REQ_WRITE)
+		if (bio->bi_rw & REQ_WRITE) {
 #else
-		if (op_is_write(bio_op(bio)))
+		if (op_is_write(bio_op(bio))) {
 #endif
-			scst_set_cmd_error(blockio_work->cmd,
-				SCST_LOAD_SENSE(scst_sense_write_error));
-		else
+			if (error == -ENOSPC) {
+				struct scst_vdisk_dev *virt_dev = blockio_work->cmd->dev->dh_priv;
+				WARN_ON(!virt_dev->thin_provisioned);
+				scst_set_cmd_error(blockio_work->cmd,
+					SCST_LOAD_SENSE(scst_space_allocation_failed_write_protect));
+			} else
+				scst_set_cmd_error(blockio_work->cmd,
+					SCST_LOAD_SENSE(scst_sense_write_error));
+		} else
 			scst_set_cmd_error(blockio_work->cmd,
 				SCST_LOAD_SENSE(scst_sense_read_error));
 
@@ -8902,6 +8927,32 @@ static ssize_t vdisk_sysfs_tp_show(struct kobject *kobj,
 	return pos;
 }
 
+static ssize_t vdisk_sysfs_gen_tp_soft_threshold_reached_UA(struct kobject *kobj,
+	struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	struct scst_device *dev;
+	struct scst_vdisk_dev *virt_dev;
+	struct scst_tgt_dev *tgt_dev;
+
+	TRACE_ENTRY();
+
+	dev = container_of(kobj, struct scst_device, dev_kobj);
+	virt_dev = dev->dh_priv;
+
+	if (!virt_dev->thin_provisioned)
+		return -EINVAL;
+
+	spin_lock_bh(&dev->dev_lock);
+	list_for_each_entry(tgt_dev, &dev->dev_tgt_dev_list,
+				dev_tgt_dev_list_entry) {
+		scst_set_tp_soft_threshold_reached_UA(tgt_dev);
+	}
+	spin_unlock_bh(&dev->dev_lock);
+
+	TRACE_EXIT_RES(count);
+	return count;
+}
+
 static ssize_t vdisk_sysfs_expl_alua_show(struct kobject *kobj,
 					  struct kobj_attribute *attr,
 					  char *buf)

scst/src/scst_lib.c

@@ -12813,6 +12813,23 @@ void scst_dev_check_set_UA(struct scst_device *dev,
 	return;
 }
 
+void scst_set_tp_soft_threshold_reached_UA(struct scst_tgt_dev *tgt_dev)
+{
+	uint8_t sense[SCST_STANDARD_SENSE_LEN];
+	int len;
+
+	TRACE_ENTRY();
+
+	len = scst_set_sense(sense, sizeof(sense), tgt_dev->dev->d_sense,
+			SCST_LOAD_SENSE(scst_sense_tp_soft_threshold_reached));
+
+	scst_check_set_UA(tgt_dev, sense, len, 0);
+
+	TRACE_EXIT();
+	return;
+}
+EXPORT_SYMBOL_GPL(scst_set_tp_soft_threshold_reached_UA);
+
 /* Called under tgt_dev_lock or when tgt_dev is unused */
 static void scst_free_all_UA(struct scst_tgt_dev *tgt_dev)
 {