From patchwork Thu Oct 21 06:06:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 12573955 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87B1AC433EF for ; Thu, 21 Oct 2021 06:06:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E3246112D for ; Thu, 21 Oct 2021 06:06:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231202AbhJUGIk (ORCPT ); Thu, 21 Oct 2021 02:08:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229499AbhJUGIf (ORCPT ); Thu, 21 Oct 2021 02:08:35 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C39E8C06161C; Wed, 20 Oct 2021 23:06:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=Ap4McAXbMpZYdcI3U+yGItsushKGrQCUAT0l5OrsKiQ=; b=iKcxIoH5yJtLHB6JiOFz19jl5w gfwRPL9UbNVU2wPIWAB3WnL4FZfLw4h8ywM3XpFNhZUyF5W5N7OqKHtB9St8afWGG/CJ2z+6Etq5t WDPEgV1I1I7JRrLmNd7fGBQ4YER4WeMSPj9OwLfZ1+jhK+aCmxOy399u3PJ5dVAEc2RZorzCI7d+k 0w33rfURrJZaLeDSfjYV+VugM7CyfJNVVshWjj8/h4C02QyRbvYuibbogbOIb0mLG87s7D4zKTD6G OFP9qbdaQiwbUBRUr/N1QXWua0eIZhiiL8i52GwHZzjZiv5mXGqAN/eTw8JeC1s6mU9fEXJIMTlc7 xrtOncWQ==; Received: from [2001:4bb8:180:8777:7df0:a8d8:40cc:3310] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mdRDU-006U4j-Mf; Thu, 21 Oct 2021 06:06:17 +0000 From: Christoph Hellwig To: Jens Axboe , "Martin K. Petersen" Cc: "J. Bruce Fields" , Chuck Lever , linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-nfs@vger.kernel.org Subject: [PATCH 2/7] sd: implement ->get_unique_id Date: Thu, 21 Oct 2021 08:06:02 +0200 Message-Id: <20211021060607.264371-3-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211021060607.264371-1-hch@lst.de> References: <20211021060607.264371-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Add the method to query for a uniqueue ID of a given type by looking it up in the cached device identification VPD page. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke --- drivers/scsi/sd.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index d8f6add416c0a..9b386ca39a913 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, };