target: break up free_device callback

With this patch free_device is now used to free what is allocated in the
alloc_device callback and destroy_device tears down the resources that are
setup in the configure_device callback.

This patch will be needed in the next patch where tcmu needs
to be able to look up the device in the destroy callback.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_device.c

@@ -974,6 +974,8 @@ void target_free_device(struct se_device *dev)
 	if (dev->dev_flags & DF_CONFIGURED) {
 		destroy_workqueue(dev->tmr_wq);
 
+		dev->transport->destroy_device(dev);
+
 		mutex_lock(&g_device_mutex);
 		list_del(&dev->g_dev_node);
 		mutex_unlock(&g_device_mutex);

drivers/target/target_core_file.c

@@ -236,14 +236,18 @@ static void fd_dev_call_rcu(struct rcu_head *p)
 }
 
 static void fd_free_device(struct se_device *dev)
+{
+	call_rcu(&dev->rcu_head, fd_dev_call_rcu);
+}
+
+static void fd_destroy_device(struct se_device *dev)
 {
 	struct fd_dev *fd_dev = FD_DEV(dev);
 
 	if (fd_dev->fd_file) {
 		filp_close(fd_dev->fd_file, NULL);
 		fd_dev->fd_file = NULL;
 	}
-	call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 }
 
 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
@@ -826,6 +830,7 @@ static const struct target_backend_ops fileio_ops = {
 	.detach_hba		= fd_detach_hba,
 	.alloc_device		= fd_alloc_device,
 	.configure_device	= fd_configure_device,
+	.destroy_device		= fd_destroy_device,
 	.free_device		= fd_free_device,
 	.parse_cdb		= fd_parse_cdb,
 	.set_configfs_dev_params = fd_set_configfs_dev_params,

drivers/target/target_core_iblock.c

@@ -189,15 +189,18 @@ static void iblock_dev_call_rcu(struct rcu_head *p)
 }
 
 static void iblock_free_device(struct se_device *dev)
+{
+	call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
+}
+
+static void iblock_destroy_device(struct se_device *dev)
 {
 	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 
 	if (ib_dev->ibd_bd != NULL)
 		blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 	if (ib_dev->ibd_bio_set != NULL)
 		bioset_free(ib_dev->ibd_bio_set);
-
-	call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 }
 
 static unsigned long long iblock_emulate_read_cap_with_block_size(
@@ -858,6 +861,7 @@ static const struct target_backend_ops iblock_ops = {
 	.detach_hba		= iblock_detach_hba,
 	.alloc_device		= iblock_alloc_device,
 	.configure_device	= iblock_configure_device,
+	.destroy_device		= iblock_destroy_device,
 	.free_device		= iblock_free_device,
 	.parse_cdb		= iblock_parse_cdb,
 	.set_configfs_dev_params = iblock_set_configfs_dev_params,

drivers/target/target_core_pscsi.c

@@ -563,6 +563,11 @@ static void pscsi_dev_call_rcu(struct rcu_head *p)
 }
 
 static void pscsi_free_device(struct se_device *dev)
+{
+	call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
+}
+
+static void pscsi_destroy_device(struct se_device *dev)
 {
 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
@@ -592,7 +597,6 @@ static void pscsi_free_device(struct se_device *dev)
 
 		pdv->pdv_sd = NULL;
 	}
-	call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
 }
 
 static void pscsi_transport_complete(struct se_cmd *cmd, struct scatterlist *sg,
@@ -1084,6 +1088,7 @@ static const struct target_backend_ops pscsi_ops = {
 	.pmode_enable_hba	= pscsi_pmode_enable_hba,
 	.alloc_device		= pscsi_alloc_device,
 	.configure_device	= pscsi_configure_device,
+	.destroy_device		= pscsi_destroy_device,
 	.free_device		= pscsi_free_device,
 	.transport_complete	= pscsi_transport_complete,
 	.parse_cdb		= pscsi_parse_cdb,

drivers/target/target_core_rd.c

@@ -338,11 +338,15 @@ static void rd_dev_call_rcu(struct rcu_head *p)
 }
 
 static void rd_free_device(struct se_device *dev)
+{
+	call_rcu(&dev->rcu_head, rd_dev_call_rcu);
+}
+
+static void rd_destroy_device(struct se_device *dev)
 {
 	struct rd_dev *rd_dev = RD_DEV(dev);
 
 	rd_release_device_space(rd_dev);
-	call_rcu(&dev->rcu_head, rd_dev_call_rcu);
 }
 
 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
@@ -651,6 +655,7 @@ static const struct target_backend_ops rd_mcp_ops = {
 	.detach_hba		= rd_detach_hba,
 	.alloc_device		= rd_alloc_device,
 	.configure_device	= rd_configure_device,
+	.destroy_device		= rd_destroy_device,
 	.free_device		= rd_free_device,
 	.parse_cdb		= rd_parse_cdb,
 	.set_configfs_dev_params = rd_set_configfs_dev_params,

drivers/target/target_core_user.c

@@ -1379,6 +1379,14 @@ 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;
@@ -1411,9 +1419,6 @@ static void tcmu_free_device(struct se_device *dev)
 
 		uio_unregister_device(&udev->uio_info);
 	}
-
-	/* release ref from init */
-	kref_put(&udev->kref, tcmu_dev_kref_release);
 }
 
 enum {
@@ -1705,6 +1710,7 @@ 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,

include/target/target_core_backend.h

@@ -30,6 +30,7 @@ struct target_backend_ops {
 
 	struct se_device *(*alloc_device)(struct se_hba *, const char *);
 	int (*configure_device)(struct se_device *);
+	void (*destroy_device)(struct se_device *);
 	void (*free_device)(struct se_device *device);
 
 	ssize_t (*set_configfs_dev_params)(struct se_device *,