diff options
Diffstat (limited to 'drivers/scsi/sd.c')
| -rw-r--r-- | drivers/scsi/sd.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index d8f6add416c0..9b386ca39a91 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1757,6 +1757,44 @@ static void sd_rescan(struct device *dev) sd_revalidate_disk(sdkp->disk); } +static int sd_get_unique_id(struct gendisk *disk, u8 id[16], + enum blk_unique_id type) +{ + struct scsi_device *sdev = scsi_disk(disk)->device; + const struct scsi_vpd *vpd; + const unsigned char *d; + int ret = -ENXIO, len; + + rcu_read_lock(); + vpd = rcu_dereference(sdev->vpd_pg83); + if (!vpd) + goto out_unlock; + + ret = -EINVAL; + for (d = vpd->data + 4; d < vpd->data + vpd->len; d += d[3] + 4) { + /* we only care about designators with LU association */ + if (((d[1] >> 4) & 0x3) != 0x00) + continue; + if ((d[1] & 0xf) != type) + continue; + + /* + * Only exit early if a 16-byte descriptor was found. Otherwise + * keep looking as one with more entropy might still show up. + */ + len = d[3]; + if (len != 8 && len != 12 && len != 16) + continue; + ret = len; + memcpy(id, d + 4, len); + if (len == 16) + break; + } +out_unlock: + rcu_read_unlock(); + return ret; +} + static char sd_pr_type(enum pr_type type) { switch (type) { @@ -1861,6 +1899,7 @@ static const struct block_device_operations sd_fops = { .check_events = sd_check_events, .unlock_native_capacity = sd_unlock_native_capacity, .report_zones = sd_zbc_report_zones, + .get_unique_id = sd_get_unique_id, .pr_ops = &sd_pr_ops, }; |