target: Remove obsolete DF_READ_ONLY usage

This was used at one time as a hack by FILEIO backend registration to
allow a struct block_device that was claimed with blkdev_get (by a local
filesystem mount for example) to be exported as read-only (SCSI WP=1).

Since FILEIO backend registration will no longer attempt to obtain
exclusive access to an underlying struct block_device here, this flag is
now obsolete.

Reported-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_device.c

@@ -1341,7 +1341,6 @@ struct se_lun *core_dev_add_lun(
 	u32 lun)
 {
 	struct se_lun *lun_p;
-	u32 lun_access = 0;
 	int rc;
 
 	if (atomic_read(&dev->dev_access_obj.obj_access_count) != 0) {
@@ -1354,12 +1353,8 @@ struct se_lun *core_dev_add_lun(
 	if (IS_ERR(lun_p))
 		return lun_p;
 
-	if (dev->dev_flags & DF_READ_ONLY)
-		lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;
-	else
-		lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;
-
-	rc = core_tpg_post_addlun(tpg, lun_p, lun_access, dev);
+	rc = core_tpg_post_addlun(tpg, lun_p,
+				TRANSPORT_LUNFLAGS_READ_WRITE, dev);
 	if (rc < 0)
 		return ERR_PTR(rc);
 

drivers/target/target_core_tpg.c

@@ -175,10 +175,7 @@ void core_tpg_add_node_to_devs(
 		 * demo_mode_write_protect is ON, or READ_ONLY;
 		 */
 		if (!tpg->se_tpg_tfo->tpg_check_demo_mode_write_protect(tpg)) {
-			if (dev->dev_flags & DF_READ_ONLY)
-				lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;
-			else
-				lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;
+			lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;
 		} else {
 			/*
 			 * Allow only optical drives to issue R/W in default RO

include/target/target_core_base.h

@@ -73,9 +73,8 @@
 /*
  * struct se_device->dev_flags
  */
-#define DF_READ_ONLY				0x00000001
-#define DF_SPC2_RESERVATIONS			0x00000002
-#define DF_SPC2_RESERVATIONS_WITH_ISID		0x00000004
+#define DF_SPC2_RESERVATIONS			0x00000001
+#define DF_SPC2_RESERVATIONS_WITH_ISID		0x00000002
 
 /* struct se_dev_attrib sanity values */
 /* Default max_unmap_lba_count */