Merge tag 'v4.13-rc1' into fixes

The fixes branch is based off a random pre-rc1 commit, because we had
some fixes that needed to go in before rc1 was released.

However we now need to fix some code that went in after that point, but
before rc1, so merge rc1 to get that code into fixes so we can fix it!

1 files changed, 397 insertions, 50 deletions

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index beb5f098f32d..80ee130f8253 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -87,6 +87,8 @@
 /* Default maximum of the global data blocks(512K * PAGE_SIZE) */
 #define TCMU_GLOBAL_MAX_BLOCKS (512 * 1024)
 
+static u8 tcmu_kern_cmd_reply_supported;
+
 static struct device *tcmu_root_device;
 
 struct tcmu_hba {
@@ -95,6 +97,13 @@ struct tcmu_hba {
 
 #define TCMU_CONFIG_LEN 256
 
+struct tcmu_nl_cmd {
+	/* wake up thread waiting for reply */
+	struct completion complete;
+	int cmd;
+	int status;
+};
+
 struct tcmu_dev {
 	struct list_head node;
 	struct kref kref;
@@ -135,6 +144,11 @@ struct tcmu_dev {
 	struct timer_list timeout;
 	unsigned int cmd_time_out;
 
+	spinlock_t nl_cmd_lock;
+	struct tcmu_nl_cmd curr_nl_cmd;
+	/* wake up threads waiting on curr_nl_cmd */
+	wait_queue_head_t nl_cmd_wq;
+
 	char dev_config[TCMU_CONFIG_LEN];
 };
 
@@ -178,16 +192,128 @@ static const struct genl_multicast_group tcmu_mcgrps[] = {
 	[TCMU_MCGRP_CONFIG] = { .name = "config", },
 };
 
+static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
+	[TCMU_ATTR_DEVICE]	= { .type = NLA_STRING },
+	[TCMU_ATTR_MINOR]	= { .type = NLA_U32 },
+	[TCMU_ATTR_CMD_STATUS]	= { .type = NLA_S32 },
+	[TCMU_ATTR_DEVICE_ID]	= { .type = NLA_U32 },
+	[TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
+};
+
+static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
+{
+	struct se_device *dev;
+	struct tcmu_dev *udev;
+	struct tcmu_nl_cmd *nl_cmd;
+	int dev_id, rc, ret = 0;
+	bool is_removed = (completed_cmd == TCMU_CMD_REMOVED_DEVICE);
+
+	if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
+	    !info->attrs[TCMU_ATTR_DEVICE_ID]) {
+		printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
+                return -EINVAL;
+        }
+
+	dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
+	rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
+
+	dev = target_find_device(dev_id, !is_removed);
+	if (!dev) {
+		printk(KERN_ERR "tcmu nl cmd %u/%u completion could not find device with dev id %u.\n",
+		       completed_cmd, rc, dev_id);
+		return -ENODEV;
+	}
+	udev = TCMU_DEV(dev);
+
+	spin_lock(&udev->nl_cmd_lock);
+	nl_cmd = &udev->curr_nl_cmd;
+
+	pr_debug("genl cmd done got id %d curr %d done %d rc %d\n", dev_id,
+		 nl_cmd->cmd, completed_cmd, rc);
+
+	if (nl_cmd->cmd != completed_cmd) {
+		printk(KERN_ERR "Mismatched commands (Expecting reply for %d. Current %d).\n",
+		       completed_cmd, nl_cmd->cmd);
+		ret = -EINVAL;
+	} else {
+		nl_cmd->status = rc;
+	}
+
+	spin_unlock(&udev->nl_cmd_lock);
+	if (!is_removed)
+		 target_undepend_item(&dev->dev_group.cg_item);
+	if (!ret)
+		complete(&nl_cmd->complete);
+	return ret;
+}
+
+static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
+{
+	return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
+}
+
+static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
+{
+	return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
+}
+
+static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
+				       struct genl_info *info)
+{
+	return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
+}
+
+static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
+{
+	if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
+		tcmu_kern_cmd_reply_supported  =
+			nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
+		printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
+		       tcmu_kern_cmd_reply_supported);
+	}
+
+	return 0;
+}
+
+static const struct genl_ops tcmu_genl_ops[] = {
+	{
+		.cmd	= TCMU_CMD_SET_FEATURES,
+		.flags	= GENL_ADMIN_PERM,
+		.policy	= tcmu_attr_policy,
+		.doit	= tcmu_genl_set_features,
+	},
+	{
+		.cmd	= TCMU_CMD_ADDED_DEVICE_DONE,
+		.flags	= GENL_ADMIN_PERM,
+		.policy	= tcmu_attr_policy,
+		.doit	= tcmu_genl_add_dev_done,
+	},
+	{
+		.cmd	= TCMU_CMD_REMOVED_DEVICE_DONE,
+		.flags	= GENL_ADMIN_PERM,
+		.policy	= tcmu_attr_policy,
+		.doit	= tcmu_genl_rm_dev_done,
+	},
+	{
+		.cmd	= TCMU_CMD_RECONFIG_DEVICE_DONE,
+		.flags	= GENL_ADMIN_PERM,
+		.policy	= tcmu_attr_policy,
+		.doit	= tcmu_genl_reconfig_dev_done,
+	},
+};
+
 /* Our generic netlink family */
 static struct genl_family tcmu_genl_family __ro_after_init = {
 	.module = THIS_MODULE,
 	.hdrsize = 0,
 	.name = "TCM-USER",
-	.version = 1,
+	.version = 2,
 	.maxattr = TCMU_ATTR_MAX,
 	.mcgrps = tcmu_mcgrps,
 	.n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
 	.netnsok = true,
+	.ops = tcmu_genl_ops,
+	.n_ops = ARRAY_SIZE(tcmu_genl_ops),
 };
 
 #define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
@@ -216,7 +342,6 @@ static inline bool tcmu_get_empty_block(struct tcmu_dev *udev,
 
 	page = radix_tree_lookup(&udev->data_blocks, dbi);
 	if (!page) {
-
 		if (atomic_add_return(1, &global_db_count) >
 					TCMU_GLOBAL_MAX_BLOCKS) {
 			atomic_dec(&global_db_count);
@@ -226,14 +351,11 @@ static inline bool tcmu_get_empty_block(struct tcmu_dev *udev,
 		/* try to get new page from the mm */
 		page = alloc_page(GFP_KERNEL);
 		if (!page)
-			return false;
+			goto err_alloc;
 
 		ret = radix_tree_insert(&udev->data_blocks, dbi, page);
-		if (ret) {
-			__free_page(page);
-			return false;
-		}
-
+		if (ret)
+			goto err_insert;
 	}
 
 	if (dbi > udev->dbi_max)
@@ -243,6 +365,11 @@ static inline bool tcmu_get_empty_block(struct tcmu_dev *udev,
 	tcmu_cmd_set_dbi(tcmu_cmd, dbi);
 
 	return true;
+err_insert:
+	__free_page(page);
+err_alloc:
+	atomic_dec(&global_db_count);
+	return false;
 }
 
 static bool tcmu_get_empty_blocks(struct tcmu_dev *udev,
@@ -401,7 +528,7 @@ static inline size_t get_block_offset_user(struct tcmu_dev *dev,
 		DATA_BLOCK_SIZE - remaining;
 }
 
-static inline size_t iov_tail(struct tcmu_dev *udev, struct iovec *iov)
+static inline size_t iov_tail(struct iovec *iov)
 {
 	return (size_t)iov->iov_base + iov->iov_len;
 }
@@ -437,10 +564,10 @@ static int scatter_data_area(struct tcmu_dev *udev,
 			to_offset = get_block_offset_user(udev, dbi,
 					block_remaining);
 			offset = DATA_BLOCK_SIZE - block_remaining;
-			to = (void *)(unsigned long)to + offset;
+			to += offset;
 
 			if (*iov_cnt != 0 &&
-			    to_offset == iov_tail(udev, *iov)) {
+			    to_offset == iov_tail(*iov)) {
 				(*iov)->iov_len += copy_bytes;
 			} else {
 				new_iov(iov, iov_cnt, udev);
@@ -510,7 +637,7 @@ static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 			copy_bytes = min_t(size_t, sg_remaining,
 					block_remaining);
 			offset = DATA_BLOCK_SIZE - block_remaining;
-			from = (void *)(unsigned long)from + offset;
+			from += offset;
 			tcmu_flush_dcache_range(from, copy_bytes);
 			memcpy(to + sg->length - sg_remaining, from,
 					copy_bytes);
@@ -596,10 +723,7 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 		}
 	}
 
-	if (!tcmu_get_empty_blocks(udev, cmd))
-		return false;
-
-	return true;
+	return tcmu_get_empty_blocks(udev, cmd);
 }
 
 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
@@ -699,25 +823,24 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 		size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 
 		entry = (void *) mb + CMDR_OFF + cmd_head;
-		tcmu_flush_dcache_range(entry, sizeof(*entry));
 		tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
 		tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
 		entry->hdr.cmd_id = 0; /* not used for PAD */
 		entry->hdr.kflags = 0;
 		entry->hdr.uflags = 0;
+		tcmu_flush_dcache_range(entry, sizeof(*entry));
 
 		UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
+		tcmu_flush_dcache_range(mb, sizeof(*mb));
 
 		cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 		WARN_ON(cmd_head != 0);
 	}
 
 	entry = (void *) mb + CMDR_OFF + cmd_head;
-	tcmu_flush_dcache_range(entry, sizeof(*entry));
+	memset(entry, 0, command_size);
 	tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
 	entry->hdr.cmd_id = tcmu_cmd->cmd_id;
-	entry->hdr.kflags = 0;
-	entry->hdr.uflags = 0;
 
 	/* Handle allocating space from the data area */
 	tcmu_cmd_reset_dbi_cur(tcmu_cmd);
@@ -736,11 +859,10 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 	}
 	entry->req.iov_cnt = iov_cnt;
-	entry->req.iov_dif_cnt = 0;
 
 	/* Handle BIDI commands */
+	iov_cnt = 0;
 	if (se_cmd->se_cmd_flags & SCF_BIDI) {
-		iov_cnt = 0;
 		iov++;
 		ret = scatter_data_area(udev, tcmu_cmd,
 					se_cmd->t_bidi_data_sg,
@@ -753,8 +875,8 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 			pr_err("tcmu: alloc and scatter bidi data failed\n");
 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 		}
-		entry->req.iov_bidi_cnt = iov_cnt;
 	}
+	entry->req.iov_bidi_cnt = iov_cnt;
 
 	/*
 	 * Recalaulate the command's base size and size according
@@ -830,8 +952,7 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *
 			cmd->se_cmd);
 		entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
 	} else if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
-		memcpy(se_cmd->sense_buffer, entry->rsp.sense_buffer,
-			       se_cmd->scsi_sense_length);
+		transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
 	} else if (se_cmd->se_cmd_flags & SCF_BIDI) {
 		/* Get Data-In buffer before clean up */
 		gather_data_area(udev, cmd, true);
@@ -989,6 +1110,9 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
 	setup_timer(&udev->timeout, tcmu_device_timedout,
 		(unsigned long)udev);
 
+	init_waitqueue_head(&udev->nl_cmd_wq);
+	spin_lock_init(&udev->nl_cmd_lock);
+
 	return &udev->se_dev;
 }
 
@@ -1140,6 +1264,7 @@ static int tcmu_open(struct uio_info *info, struct inode *inode)
 		return -EBUSY;
 
 	udev->inode = inode;
+	kref_get(&udev->kref);
 
 	pr_debug("open\n");
 
@@ -1171,12 +1296,59 @@ static int tcmu_release(struct uio_info *info, struct inode *inode)
 	clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
 
 	pr_debug("close\n");
-	/* release ref from configure */
+	/* release ref from open */
 	kref_put(&udev->kref, tcmu_dev_kref_release);
 	return 0;
 }
 
-static int tcmu_netlink_event(enum tcmu_genl_cmd cmd, const char *name, int minor)
+static void tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
+{
+	struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
+
+	if (!tcmu_kern_cmd_reply_supported)
+		return;
+relock:
+	spin_lock(&udev->nl_cmd_lock);
+
+	if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
+		spin_unlock(&udev->nl_cmd_lock);
+		pr_debug("sleeping for open nl cmd\n");
+		wait_event(udev->nl_cmd_wq, (nl_cmd->cmd == TCMU_CMD_UNSPEC));
+		goto relock;
+	}
+
+	memset(nl_cmd, 0, sizeof(*nl_cmd));
+	nl_cmd->cmd = cmd;
+	init_completion(&nl_cmd->complete);
+
+	spin_unlock(&udev->nl_cmd_lock);
+}
+
+static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
+{
+	struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
+	int ret;
+	DEFINE_WAIT(__wait);
+
+	if (!tcmu_kern_cmd_reply_supported)
+		return 0;
+
+	pr_debug("sleeping for nl reply\n");
+	wait_for_completion(&nl_cmd->complete);
+
+	spin_lock(&udev->nl_cmd_lock);
+	nl_cmd->cmd = TCMU_CMD_UNSPEC;
+	ret = nl_cmd->status;
+	nl_cmd->status = 0;
+	spin_unlock(&udev->nl_cmd_lock);
+
+	wake_up_all(&udev->nl_cmd_wq);
+
+	return ret;;
+}
+
+static int tcmu_netlink_event(struct tcmu_dev *udev, enum tcmu_genl_cmd cmd,
+			      int reconfig_attr, const void *reconfig_data)
 {
 	struct sk_buff *skb;
 	void *msg_header;
@@ -1190,22 +1362,51 @@ static int tcmu_netlink_event(enum tcmu_genl_cmd cmd, const char *name, int mino
 	if (!msg_header)
 		goto free_skb;
 
-	ret = nla_put_string(skb, TCMU_ATTR_DEVICE, name);
+	ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
+	if (ret < 0)
+		goto free_skb;
+
+	ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
 	if (ret < 0)
 		goto free_skb;
 
-	ret = nla_put_u32(skb, TCMU_ATTR_MINOR, minor);
+	ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
 	if (ret < 0)
 		goto free_skb;
 
+	if (cmd == TCMU_CMD_RECONFIG_DEVICE) {
+		switch (reconfig_attr) {
+		case TCMU_ATTR_DEV_CFG:
+			ret = nla_put_string(skb, reconfig_attr, reconfig_data);
+			break;
+		case TCMU_ATTR_DEV_SIZE:
+			ret = nla_put_u64_64bit(skb, reconfig_attr,
+						*((u64 *)reconfig_data),
+						TCMU_ATTR_PAD);
+			break;
+		case TCMU_ATTR_WRITECACHE:
+			ret = nla_put_u8(skb, reconfig_attr,
+					  *((u8 *)reconfig_data));
+			break;
+		default:
+			BUG();
+		}
+
+		if (ret < 0)
+			goto free_skb;
+	}
+
 	genlmsg_end(skb, msg_header);
 
+	tcmu_init_genl_cmd_reply(udev, cmd);
+
 	ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
 				TCMU_MCGRP_CONFIG, GFP_KERNEL);
-
 	/* We don't care if no one is listening */
 	if (ret == -ESRCH)
 		ret = 0;
+	if (!ret)
+		ret = tcmu_wait_genl_cmd_reply(udev);
 
 	return ret;
 free_skb:
@@ -1213,19 +1414,14 @@ free_skb:
 	return ret;
 }
 
-static int tcmu_configure_device(struct se_device *dev)
+static int tcmu_update_uio_info(struct tcmu_dev *udev)
 {
-	struct tcmu_dev *udev = TCMU_DEV(dev);
 	struct tcmu_hba *hba = udev->hba->hba_ptr;
 	struct uio_info *info;
-	struct tcmu_mailbox *mb;
-	size_t size;
-	size_t used;
-	int ret = 0;
+	size_t size, used;
 	char *str;
 
 	info = &udev->uio_info;
-
 	size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name,
 			udev->dev_config);
 	size += 1; /* for \0 */
@@ -1234,12 +1430,27 @@ static int tcmu_configure_device(struct se_device *dev)
 		return -ENOMEM;
 
 	used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name);
-
 	if (udev->dev_config[0])
 		snprintf(str + used, size - used, "/%s", udev->dev_config);
 
 	info->name = str;
 
+	return 0;
+}
+
+static int tcmu_configure_device(struct se_device *dev)
+{
+	struct tcmu_dev *udev = TCMU_DEV(dev);
+	struct uio_info *info;
+	struct tcmu_mailbox *mb;
+	int ret = 0;
+
+	ret = tcmu_update_uio_info(udev);
+	if (ret)
+		return ret;
+
+	info = &udev->uio_info;
+
 	udev->mb_addr = vzalloc(CMDR_SIZE);
 	if (!udev->mb_addr) {
 		ret = -ENOMEM;
@@ -1290,6 +1501,8 @@ static int tcmu_configure_device(struct se_device *dev)
 	/* Other attributes can be configured in userspace */
 	if (!dev->dev_attrib.hw_max_sectors)
 		dev->dev_attrib.hw_max_sectors = 128;
+	if (!dev->dev_attrib.emulate_write_cache)
+		dev->dev_attrib.emulate_write_cache = 0;
 	dev->dev_attrib.hw_queue_depth = 128;
 
 	/*
@@ -1298,8 +1511,7 @@ static int tcmu_configure_device(struct se_device *dev)
 	 */
 	kref_get(&udev->kref);
 
-	ret = tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE, udev->uio_info.name,
-				 udev->uio_info.uio_dev->minor);
+	ret = tcmu_netlink_event(udev, TCMU_CMD_ADDED_DEVICE, 0, NULL);
 	if (ret)
 		goto err_netlink;
 
@@ -1355,6 +1567,14 @@ static void tcmu_blocks_release(struct tcmu_dev *udev)
 static void tcmu_free_device(struct se_device *dev)
 {
 	struct tcmu_dev *udev = TCMU_DEV(dev);
+
+	/* release ref from init */
+	kref_put(&udev->kref, tcmu_dev_kref_release);
+}
+
+static void tcmu_destroy_device(struct se_device *dev)
+{
+	struct tcmu_dev *udev = TCMU_DEV(dev);
 	struct tcmu_cmd *cmd;
 	bool all_expired = true;
 	int i;
@@ -1379,14 +1599,11 @@ static void tcmu_free_device(struct se_device *dev)
 
 	tcmu_blocks_release(udev);
 
-	if (tcmu_dev_configured(udev)) {
-		tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE, udev->uio_info.name,
-				   udev->uio_info.uio_dev->minor);
+	tcmu_netlink_event(udev, TCMU_CMD_REMOVED_DEVICE, 0, NULL);
 
-		uio_unregister_device(&udev->uio_info);
-	}
+	uio_unregister_device(&udev->uio_info);
 
-	/* release ref from init */
+	/* release ref from configure */
 	kref_put(&udev->kref, tcmu_dev_kref_release);
 }
 
@@ -1546,6 +1763,129 @@ static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *pag
 }
 CONFIGFS_ATTR(tcmu_, cmd_time_out);
 
+static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
+{
+	struct se_dev_attrib *da = container_of(to_config_group(item),
+						struct se_dev_attrib, da_group);
+	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
+
+	return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
+}
+
+static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
+				     size_t count)
+{
+	struct se_dev_attrib *da = container_of(to_config_group(item),
+						struct se_dev_attrib, da_group);
+	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
+	int ret, len;
+
+	len = strlen(page);
+	if (!len || len > TCMU_CONFIG_LEN - 1)
+		return -EINVAL;
+
+	/* Check if device has been configured before */
+	if (tcmu_dev_configured(udev)) {
+		ret = tcmu_netlink_event(udev, TCMU_CMD_RECONFIG_DEVICE,
+					 TCMU_ATTR_DEV_CFG, page);
+		if (ret) {
+			pr_err("Unable to reconfigure device\n");
+			return ret;
+		}
+		strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
+
+		ret = tcmu_update_uio_info(udev);
+		if (ret)
+			return ret;
+		return count;
+	}
+	strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
+
+	return count;
+}
+CONFIGFS_ATTR(tcmu_, dev_config);
+
+static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
+{
+	struct se_dev_attrib *da = container_of(to_config_group(item),
+						struct se_dev_attrib, da_group);
+	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
+
+	return snprintf(page, PAGE_SIZE, "%zu\n", udev->dev_size);
+}
+
+static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
+				   size_t count)
+{
+	struct se_dev_attrib *da = container_of(to_config_group(item),
+						struct se_dev_attrib, da_group);
+	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
+	u64 val;
+	int ret;
+
+	ret = kstrtou64(page, 0, &val);
+	if (ret < 0)
+		return ret;
+
+	/* Check if device has been configured before */
+	if (tcmu_dev_configured(udev)) {
+		ret = tcmu_netlink_event(udev, TCMU_CMD_RECONFIG_DEVICE,
+					 TCMU_ATTR_DEV_SIZE, &val);
+		if (ret) {
+			pr_err("Unable to reconfigure device\n");
+			return ret;
+		}
+	}
+	udev->dev_size = val;
+	return count;
+}
+CONFIGFS_ATTR(tcmu_, dev_size);
+
+static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
+					     char *page)
+{
+	struct se_dev_attrib *da = container_of(to_config_group(item),
+					struct se_dev_attrib, da_group);
+
+	return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
+}
+
+static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
+					      const char *page, size_t count)
+{
+	struct se_dev_attrib *da = container_of(to_config_group(item),
+					struct se_dev_attrib, da_group);
+	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
+	u8 val;
+	int ret;
+
+	ret = kstrtou8(page, 0, &val);
+	if (ret < 0)
+		return ret;
+
+	/* Check if device has been configured before */
+	if (tcmu_dev_configured(udev)) {
+		ret = tcmu_netlink_event(udev, TCMU_CMD_RECONFIG_DEVICE,
+					 TCMU_ATTR_WRITECACHE, &val);
+		if (ret) {
+			pr_err("Unable to reconfigure device\n");
+			return ret;
+		}
+	}
+
+	da->emulate_write_cache = val;
+	return count;
+}
+CONFIGFS_ATTR(tcmu_, emulate_write_cache);
+
+static struct configfs_attribute *tcmu_attrib_attrs[] = {
+	&tcmu_attr_cmd_time_out,
+	&tcmu_attr_dev_config,
+	&tcmu_attr_dev_size,
+	&tcmu_attr_emulate_write_cache,
+	NULL,
+};
+
 static struct configfs_attribute **tcmu_attrs;
 
 static struct target_backend_ops tcmu_ops = {
@@ -1556,6 +1896,7 @@ static struct target_backend_ops tcmu_ops = {
 	.detach_hba		= tcmu_detach_hba,
 	.alloc_device		= tcmu_alloc_device,
 	.configure_device	= tcmu_configure_device,
+	.destroy_device		= tcmu_destroy_device,
 	.free_device		= tcmu_free_device,
 	.parse_cdb		= tcmu_parse_cdb,
 	.set_configfs_dev_params = tcmu_set_configfs_dev_params,
@@ -1573,7 +1914,7 @@ static int unmap_thread_fn(void *data)
 	struct page *page;
 	int i;
 
-	while (1) {
+	while (!kthread_should_stop()) {
 		DEFINE_WAIT(__wait);
 
 		prepare_to_wait(&unmap_wait, &__wait, TASK_INTERRUPTIBLE);
@@ -1645,7 +1986,7 @@ static int unmap_thread_fn(void *data)
 
 static int __init tcmu_module_init(void)
 {
-	int ret, i, len = 0;
+	int ret, i, k, len = 0;
 
 	BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
 
@@ -1670,7 +2011,10 @@ static int __init tcmu_module_init(void)
 	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
 		len += sizeof(struct configfs_attribute *);
 	}
-	len += sizeof(struct configfs_attribute *) * 2;
+	for (i = 0; tcmu_attrib_attrs[i] != NULL; i++) {
+		len += sizeof(struct configfs_attribute *);
+	}
+	len += sizeof(struct configfs_attribute *);
 
 	tcmu_attrs = kzalloc(len, GFP_KERNEL);
 	if (!tcmu_attrs) {
@@ -1681,7 +2025,10 @@ static int __init tcmu_module_init(void)
 	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
 		tcmu_attrs[i] = passthrough_attrib_attrs[i];
 	}
-	tcmu_attrs[i] = &tcmu_attr_cmd_time_out;
+	for (k = 0; tcmu_attrib_attrs[k] != NULL; k++) {
+		tcmu_attrs[i] = tcmu_attrib_attrs[k];
+		i++;
+	}
 	tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
 
 	ret = transport_backend_register(&tcmu_ops);