scsi: scsi_debug: Disallow zone sizes that are not powers of 2 (108e36f0) · Commits · 戴 / test

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: ("scsi: scsi_debug: Add zone_size_mb module parameter") Fixes: ("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>

drivers/scsi/scsi_debug.c

+7 −10

Original line number	Diff line number	Diff line
		@@ -2657,13 +2657,7 @@ static inline bool sdebug_dev_is_zoned(struct sdebug_dev_info *devip)
		static struct sdeb_zone_state zbc_zone(struct sdebug_dev_info devip,
		unsigned long long lba)
		{
		unsigned int zno;

		if (devip->zsize_shift)
		zno = lba >> devip->zsize_shift;
		else
		zno = lba / devip->zsize;
		return &devip->zstate[zno];
		return &devip->zstate[lba >> devip->zsize_shift];
		}

		static inline bool zbc_zone_is_conv(struct sdeb_zone_state *zsp)
		@@ -4306,7 +4300,7 @@ static int resp_report_zones(struct scsi_cmnd *scp,
		return check_condition_result;
		}

		max_zones = devip->nr_zones - zs_lba / devip->zsize;
		max_zones = devip->nr_zones - (zs_lba >> devip->zsize_shift);
		rep_max_zones = min((alloc_len - 64) >> ilog2(RZONES_DESC_HD),
		max_zones);

		@@ -4826,6 +4820,10 @@ static int sdebug_device_create_zones(struct sdebug_dev_info *devip)
		return -EINVAL;
		}
		} else {
		if (!is_power_of_2(sdeb_zbc_zone_size_mb)) {
		pr_err("Zone size is not a power of 2\n");
		return -EINVAL;
		}
		devip->zsize = (sdeb_zbc_zone_size_mb * SZ_1M)
		>> ilog2(sdebug_sector_size);
		if (devip->zsize >= capacity) {
		@@ -4834,7 +4832,6 @@ static int sdebug_device_create_zones(struct sdebug_dev_info *devip)
		}
		}

		if (is_power_of_2(devip->zsize))
		devip->zsize_shift = ilog2(devip->zsize);
		devip->nr_zones = (capacity + devip->zsize - 1) >> devip->zsize_shift;

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