isofs: stop using ioctl_by_bdev

Instead just call the CDROM layer functionality directly, and turn the
hot mess in isofs_get_last_session into remotely readable code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/isofs/inode.c

@@ -544,43 +544,41 @@ static int isofs_show_options(struct seq_file *m, struct dentry *root)
 
 static unsigned int isofs_get_last_session(struct super_block *sb, s32 session)
 {
-	struct cdrom_multisession ms_info;
-	unsigned int vol_desc_start;
-	struct block_device *bdev = sb->s_bdev;
-	int i;
+	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
+	unsigned int vol_desc_start = 0;
 
-	vol_desc_start=0;
-	ms_info.addr_format=CDROM_LBA;
 	if (session > 0) {
-		struct cdrom_tocentry Te;
-		Te.cdte_track=session;
-		Te.cdte_format=CDROM_LBA;
-		i = ioctl_by_bdev(bdev, CDROMREADTOCENTRY, (unsigned long) &Te);
-		if (!i) {
+		struct cdrom_tocentry te;
+
+		if (!cdi)
+			return 0;
+
+		te.cdte_track = session;
+		te.cdte_format = CDROM_LBA;
+		if (cdrom_read_tocentry(cdi, &te) == 0) {
 			printk(KERN_DEBUG "ISOFS: Session %d start %d type %d\n",
-				session, Te.cdte_addr.lba,
-				Te.cdte_ctrl&CDROM_DATA_TRACK);
-			if ((Te.cdte_ctrl&CDROM_DATA_TRACK) == 4)
-				return Te.cdte_addr.lba;
+				session, te.cdte_addr.lba,
+				te.cdte_ctrl & CDROM_DATA_TRACK);
+			if ((te.cdte_ctrl & CDROM_DATA_TRACK) == 4)
+				return te.cdte_addr.lba;
 		}
 
 		printk(KERN_ERR "ISOFS: Invalid session number or type of track\n");
 	}
-	i = ioctl_by_bdev(bdev, CDROMMULTISESSION, (unsigned long) &ms_info);
-	if (session > 0)
-		printk(KERN_ERR "ISOFS: Invalid session number\n");
-#if 0
-	printk(KERN_DEBUG "isofs.inode: CDROMMULTISESSION: rc=%d\n",i);
-	if (i==0) {
-		printk(KERN_DEBUG "isofs.inode: XA disk: %s\n",ms_info.xa_flag?"yes":"no");
-		printk(KERN_DEBUG "isofs.inode: vol_desc_start = %d\n", ms_info.addr.lba);
-	}
-#endif
-	if (i==0)
+
+	if (cdi) {
+		struct cdrom_multisession ms_info;
+
+		ms_info.addr_format = CDROM_LBA;
+		if (cdrom_multisession(cdi, &ms_info) == 0) {
 #if WE_OBEY_THE_WRITTEN_STANDARDS
-		if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
+			/* necessary for a valid ms_info.addr */
+			if (ms_info.xa_flag)
 #endif
-			vol_desc_start=ms_info.addr.lba;
+				vol_desc_start = ms_info.addr.lba;
+		}
+	}
+
 	return vol_desc_start;
 }