udf: stop using ioctl_by_bdev

Instead just call the CDROM layer functionality directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/udf/lowlevel.c

@@ -27,41 +27,38 @@
 
 unsigned int udf_get_last_session(struct super_block *sb)
 {
+	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
 	struct cdrom_multisession ms_info;
-	unsigned int vol_desc_start;
-	struct block_device *bdev = sb->s_bdev;
-	int i;
 
-	vol_desc_start = 0;
-	ms_info.addr_format = CDROM_LBA;
-	i = ioctl_by_bdev(bdev, CDROMMULTISESSION, (unsigned long)&ms_info);
+	if (!cdi) {
+		udf_debug("CDROMMULTISESSION not supported.\n");
+		return 0;
+	}
 
-	if (i == 0) {
+	ms_info.addr_format = CDROM_LBA;
+	if (cdrom_multisession(cdi, &ms_info) == 0) {
 		udf_debug("XA disk: %s, vol_desc_start=%d\n",
 			  ms_info.xa_flag ? "yes" : "no", ms_info.addr.lba);
 		if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
-			vol_desc_start = ms_info.addr.lba;
-	} else {
-		udf_debug("CDROMMULTISESSION not supported: rc=%d\n", i);
+			return ms_info.addr.lba;
 	}
-	return vol_desc_start;
+	return 0;
 }
 
 unsigned long udf_get_last_block(struct super_block *sb)
 {
 	struct block_device *bdev = sb->s_bdev;
+	struct cdrom_device_info *cdi = disk_to_cdi(bdev->bd_disk);
 	unsigned long lblock = 0;
 
 	/*
-	 * ioctl failed or returned obviously bogus value?
+	 * The cdrom layer call failed or returned obviously bogus value?
 	 * Try using the device size...
 	 */
-	if (ioctl_by_bdev(bdev, CDROM_LAST_WRITTEN, (unsigned long) &lblock) ||
-	    lblock == 0)
+	if (!cdi || cdrom_get_last_written(cdi, &lblock) || lblock == 0)
 		lblock = i_size_read(bdev->bd_inode) >> sb->s_blocksize_bits;
 
 	if (lblock)
 		return lblock - 1;
-	else
 	return 0;
 }