Commit e28e5055 authored Mar 22, 2019 by Peter Oberparleiter Committed by Greg Kroah-Hartman May 16, 2019

s390/dasd: Fix capacity calculation for large volumes



[ Upstream commit 2cc9637ce825f3a9f51f8f78af7474e9e85bfa5f ]

The DASD driver incorrectly limits the maximum number of blocks of ECKD
DASD volumes to 32 bit numbers. Volumes with a capacity greater than
2^32-1 blocks are incorrectly recognized as smaller volumes.

This results in the following volume capacity limits depending on the
formatted block size:

  BLKSIZE  MAX_GB   MAX_CYL
      512    2047   5843492c
     1024    4095   8676701
     2048    8191  13634816
     4096   16383  23860929

The same problem occurs when a volume with more than 17895697 cylinders
is accessed in raw-track-access mode.

Fix this problem by adding an explicit type cast when calculating the
maximum number of blocks.

Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent af5b7a15

drivers/s390/block/dasd_eckd.c

+3 −3

Original line number	Original line	Diff line number	Diff line
	@@ -2004,14 +2004,14 @@ static int dasd_eckd_end_analysis(struct dasd_block *block)
	blk_per_trk = recs_per_track(&private->rdc_data, 0, block->bp_block);		blk_per_trk = recs_per_track(&private->rdc_data, 0, block->bp_block);

	raw:		raw:
	block->blocks = (private->real_cyl *		block->blocks = ((unsigned long) private->real_cyl *
	private->rdc_data.trk_per_cyl *		private->rdc_data.trk_per_cyl *
	blk_per_trk);		blk_per_trk);

	dev_info(&device->cdev->dev,		dev_info(&device->cdev->dev,
	"DASD with %d KB/block, %d KB total size, %d KB/track, "		"DASD with %u KB/block, %lu KB total size, %u KB/track, "
	"%s\n", (block->bp_block >> 10),		"%s\n", (block->bp_block >> 10),
	((private->real_cyl *		(((unsigned long) private->real_cyl *
	private->rdc_data.trk_per_cyl *		private->rdc_data.trk_per_cyl *
	blk_per_trk * (block->bp_block >> 9)) >> 1),		blk_per_trk * (block->bp_block >> 9)) >> 1),
	((blk_per_trk * block->bp_block) >> 10),		((blk_per_trk * block->bp_block) >> 10),