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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Peter Oberparleiter <oberpar@linux.ibm.com>,
        Stefan Haberland <sth@linux.ibm.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 3.18 67/86] s390/dasd: Fix capacity calculation for large volumes
Date:   Wed, 15 May 2019 12:55:44 +0200
Message-Id: <20190515090654.762720869@linuxfoundation.org>
In-Reply-To: <20190515090642.339346723@linuxfoundation.org>
References: <20190515090642.339346723@linuxfoundation.org>
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[ 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   5843492
     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>
---
 drivers/s390/block/dasd_eckd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 4bbcdf991c262..4856e5bbb42fa 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -2031,14 +2031,14 @@ static int dasd_eckd_end_analysis(struct dasd_block *block)
 	blk_per_trk = recs_per_track(&private->rdc_data, 0, block->bp_block);
 
 raw:
-	block->blocks = (private->real_cyl *
+	block->blocks = ((unsigned long) private->real_cyl *
 			  private->rdc_data.trk_per_cyl *
 			  blk_per_trk);
 
 	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),
-		 ((private->real_cyl *
+		 (((unsigned long) private->real_cyl *
 		   private->rdc_data.trk_per_cyl *
 		   blk_per_trk * (block->bp_block >> 9)) >> 1),
 		 ((blk_per_trk * block->bp_block) >> 10),
-- 
2.20.1