scsi: scsi_debug: Disallow zone sizes that are not powers of 2

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Allowing a non-power-of-2 zone size forces the use of direct division
operations of 64-bit sector values to obtain a zone number or number of
zones. Doing so without using do_div() leads to compilation errors on
32-bit architectures.

Devices with a zone size that is not a power of 2 do not exist today so
allowing their emulation is of limited interest as the sd driver will not
support them anyway. To fix this compilation error, instead of using
do_div() for sector values divisions, simply disallow zone size values that
are not a power of 2.

[mkp: commit desc]

Link: https://lore.kernel.org/r/20200507023526.221574-1-damien.lemoal@wdc.com
Fixes: 98e0a68986 ("scsi: scsi_debug: Add zone_size_mb module parameter")
Fixes: f0d1cf9378 ("scsi: scsi_debug: Add ZBC zone commands")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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Damien Le Moal 2020-05-07 11:35:26 +09:00 • committed by Martin K. Petersen

parent 64e14ece07

commit 108e36f0d8

1 changed files with 7 additions and 10 deletions

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drivers/scsi/scsi_debug.c

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