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Commit e815d365 authored by Damien Le Moal's avatar Damien Le Moal Committed by Jens Axboe
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scsi: sd: add concurrent positioning ranges support



Add the sd_read_cpr() function to the sd scsi disk driver to discover
if a device has multiple concurrent positioning ranges (i.e. multiple
actuators on an HDD). The existence of VPD page B9h indicates if a
device has multiple concurrent positioning ranges. The page content
describes each range supported by the device.

sd_read_cpr() is called from sd_revalidate_disk() and uses the block
layer functions disk_alloc_independent_access_ranges() and
disk_set_independent_access_ranges() to represent the set of actuators
of the device as independent access ranges.

The format of the Concurrent Positioning Ranges VPD page B9h is defined
in section 6.6.6 of SBC-5.

Signed-off-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: default avatarKeith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20211027022223.183838-3-damien.lemoal@wdc.com
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a2247f19
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