ide-tape: add ide_tape_set_media_lock() helper

Add ide_tape_set_media_lock() helper and convert idetape_mtioctop(),
idetape_chrdev_open() and idetape_chrdev_release() to use it.

There should be no functional changes caused by this patch (it is
OK to modify ->door_locked if idetape_create_prevent_cmd() fails).

Acked-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-tape.c

@@ -1299,6 +1299,16 @@ static int idetape_create_prevent_cmd(ide_drive_t *drive,
 	return 1;
 }
 
+static int ide_tape_set_media_lock(ide_drive_t *drive, int on)
+{
+	struct ide_atapi_pc pc;
+
+	if (!idetape_create_prevent_cmd(drive, &pc, on))
+		return 0;
+
+	return idetape_queue_pc_tail(drive, &pc);
+}
+
 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 {
 	idetape_tape_t *tape = drive->driver_data;
@@ -1927,9 +1937,8 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 		 * attempting to eject.
 		 */
 		if (tape->door_locked) {
-			if (idetape_create_prevent_cmd(drive, &pc, 0))
-				if (!idetape_queue_pc_tail(drive, &pc))
-					tape->door_locked = DOOR_UNLOCKED;
+			if (!ide_tape_set_media_lock(drive, 0))
+				tape->door_locked = DOOR_UNLOCKED;
 		}
 		ide_tape_discard_merge_buffer(drive, 0);
 		idetape_create_load_unload_cmd(drive, &pc,
@@ -1973,17 +1982,13 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 	case MTFSR:
 	case MTBSR:
 	case MTLOCK:
-		if (!idetape_create_prevent_cmd(drive, &pc, 1))
-			return 0;
-		retval = idetape_queue_pc_tail(drive, &pc);
+		retval = ide_tape_set_media_lock(drive, 1);
 		if (retval)
 			return retval;
 		tape->door_locked = DOOR_EXPLICITLY_LOCKED;
 		return 0;
 	case MTUNLOCK:
-		if (!idetape_create_prevent_cmd(drive, &pc, 0))
-			return 0;
-		retval = idetape_queue_pc_tail(drive, &pc);
+		retval = ide_tape_set_media_lock(drive, 0);
 		if (retval)
 			return retval;
 		tape->door_locked = DOOR_UNLOCKED;
@@ -2085,7 +2090,6 @@ static int idetape_chrdev_open(struct inode *inode, struct file *filp)
 	unsigned int minor = iminor(inode), i = minor & ~0xc0;
 	ide_drive_t *drive;
 	idetape_tape_t *tape;
-	struct ide_atapi_pc pc;
 	int retval;
 
 	if (i >= MAX_HWIFS * MAX_DRIVES)
@@ -2148,11 +2152,9 @@ static int idetape_chrdev_open(struct inode *inode, struct file *filp)
 
 	/* Lock the tape drive door so user can't eject. */
 	if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
-		if (idetape_create_prevent_cmd(drive, &pc, 1)) {
-			if (!idetape_queue_pc_tail(drive, &pc)) {
-				if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
-					tape->door_locked = DOOR_LOCKED;
-			}
+		if (!ide_tape_set_media_lock(drive, 1)) {
+			if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
+				tape->door_locked = DOOR_LOCKED;
 		}
 	}
 	unlock_kernel();
@@ -2185,7 +2187,6 @@ static int idetape_chrdev_release(struct inode *inode, struct file *filp)
 {
 	struct ide_tape_obj *tape = ide_tape_f(filp);
 	ide_drive_t *drive = tape->drive;
-	struct ide_atapi_pc pc;
 	unsigned int minor = iminor(inode);
 
 	lock_kernel();
@@ -2204,10 +2205,8 @@ static int idetape_chrdev_release(struct inode *inode, struct file *filp)
 		(void) idetape_rewind_tape(drive);
 	if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
 		if (tape->door_locked == DOOR_LOCKED) {
-			if (idetape_create_prevent_cmd(drive, &pc, 0)) {
-				if (!idetape_queue_pc_tail(drive, &pc))
-					tape->door_locked = DOOR_UNLOCKED;
-			}
+			if (!ide_tape_set_media_lock(drive, 0))
+				tape->door_locked = DOOR_UNLOCKED;
 		}
 	}
 	clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);