block: update a few comments in uapi/linux/blkpg.h

The big top of the file comment talk about grand plans that never
happened, so remove them to not confuse the readers.  Also mark the
devname and volname fields as ignored as they were never used by the
kernel.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Christoph Hellwig

include/uapi/linux/blkpg.h

@@ -2,29 +2,6 @@
 #ifndef _UAPI__LINUX_BLKPG_H
 #define _UAPI__LINUX_BLKPG_H
 
-/*
- * Partition table and disk geometry handling
- *
- * A single ioctl with lots of subfunctions:
- *
- * Device number stuff:
- *    get_whole_disk()		(given the device number of a partition,
- *                               find the device number of the encompassing disk)
- *    get_all_partitions()	(given the device number of a disk, return the
- *				 device numbers of all its known partitions)
- *
- * Partition stuff:
- *    add_partition()
- *    delete_partition()
- *    test_partition_in_use()	(also for test_disk_in_use)
- *
- * Geometry stuff:
- *    get_geometry()
- *    set_geometry()
- *    get_bios_drivedata()
- *
- * For today, only the partition stuff - aeb, 990515
- */
 #include <linux/compiler.h>
 #include <linux/ioctl.h>
 
@@ -52,9 +29,8 @@ struct blkpg_partition {
 	long long start;		/* starting offset in bytes */
 	long long length;		/* length in bytes */
 	int pno;			/* partition number */
-	char devname[BLKPG_DEVNAMELTH];	/* partition name, like sda5 or c0d1p2,
-					   to be used in kernel messages */
-	char volname[BLKPG_VOLNAMELTH];	/* volume label */
+	char devname[BLKPG_DEVNAMELTH];	/* unused / ignored */
+	char volname[BLKPG_VOLNAMELTH];	/* unused / ignore */
 };
 
 #endif /* _UAPI__LINUX_BLKPG_H */