• Damien Le Moal's avatar
    block: fix revalidate performance regression · 47fe1c30
    Damien Le Moal authored
    The scsi driver function sd_read_block_characteristics() always calls
    disk_set_zoned() to a disk zoned model correctly, in case the device
    model changed. This is done even for regular disks to set the zoned
    model to BLK_ZONED_NONE and free any zone related resources if the drive
    previously was zoned.
    
    This behavior significantly impact the time it takes to revalidate disks
    on a large system as the call to disk_clear_zone_settings() done from
    disk_set_zoned() for the BLK_ZONED_NONE case results in the device
    request queued to be frozen, even if there are no zone resources to
    free.
    
    Avoid this overhead for non-zoned devices by not calling
    disk_clear_zone_settings() in disk_set_zoned() if the device model
    was already set to BLK_ZONED_NONE, which is always the case for regular
    devices.
    
    Reported by: Brian Bunker <brian@purestorage.com>
    
    Fixes: 508aebb8 ("block: introduce blk_queue_clear_zone_settings()")
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarDamien Le Moal <dlemoal@kernel.org>
    Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
    Link: https://lore.kernel.org/r/20230529073237.1339862-1-dlemoal@kernel.orgSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
    47fe1c30
blk-settings.c 30.4 KB