From: Mike Christie <mchristi@redhat.com>
Date: Fri, 23 Jun 2017 01:18:14 -0500
Subject: target: add helper to find se_device by dev_index
Git-commit: 85441e6b8c97964a6da72135dc21f708adbdc4d8
Patch-mainline: v4.13-rc1
References: fate#323946
This adds a helper to find a se_device by dev_index. It will
be used in the next patches so tcmu's netlink interface can
execute commands on specific devices.
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>
Acked-by: Lee Duncan <lduncan@suse.com>
---
drivers/target/target_core_device.c | 24 ++++++++++++++++++++++++
include/target/target_core_backend.h | 2 ++
2 files changed, 26 insertions(+)
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index f10dfe7b1d54..de1131612ddc 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -880,6 +880,30 @@ sector_t target_to_linux_sector(struct se_device *dev, sector_t lb)
}
EXPORT_SYMBOL(target_to_linux_sector);
+/**
+ * target_find_device - find a se_device by its dev_index
+ * @id: dev_index
+ * @do_depend: true if caller needs target_depend_item to be done
+ *
+ * If do_depend is true, the caller must do a target_undepend_item
+ * when finished using the device.
+ *
+ * If do_depend is false, the caller must be called in a configfs
+ * callback or during removal.
+ */
+struct se_device *target_find_device(int id, bool do_depend)
+{
+ struct se_device *dev;
+
+ mutex_lock(&g_device_mutex);
+ dev = idr_find(&devices_idr, id);
+ if (dev && do_depend && target_depend_item(&dev->dev_group.cg_item))
+ dev = NULL;
+ mutex_unlock(&g_device_mutex);
+ return dev;
+}
+EXPORT_SYMBOL(target_find_device);
+
int target_configure_device(struct se_device *dev)
{
struct se_hba *hba = dev->se_hba;
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 3dbcacd7e8d7..1f2b7007f2df 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -106,6 +106,8 @@ sense_reason_t transport_generic_map_mem_to_cmd(struct se_cmd *,
sense_reason_t passthrough_parse_cdb(struct se_cmd *cmd,
sense_reason_t (*exec_cmd)(struct se_cmd *cmd));
+struct se_device *target_find_device(int id, bool do_depend);
+
bool target_sense_desc_format(struct se_device *dev);
sector_t target_to_linux_sector(struct se_device *dev, sector_t lb);
bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,