From patchwork Thu Oct 31 15:06:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Coddington X-Patchwork-Id: 13858014 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EBDD619C552 for ; Thu, 31 Oct 2024 15:06:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730387222; cv=none; b=Ru8OL6VDgsnRm2h3MLGNJInKHQGdRVd1awQKhgCC8GRMyYIeMKrMVj73OQi0DQce8kK3pggC9rWrJqmNly6H5IS73Kt/cNOrGhVx4Fc9rHtQQnGs8fLreGu2MasfTUvXcSrMNc2Zvapf9GRk7nIp7e3GTZ5+4uiTgghJJAbH3UQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730387222; c=relaxed/simple; bh=h2EeO+RDrnIsPHyYE0q67DkKeZA7IVsjRSvZ1TyeRsY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=i/lfi8uasSfwH7zE17rkVFhRFcTe69DsAHf7YBqKkpOlnwBZDIpys17Aip+3FVPNAJQ23H+NDGEWXnYu/G93COY1a+vdX1myEi5vaZ5uDMs8T2J6ANYVpQwrvogDJYrsNFYtBYontMVXeLtdsQ8toGva3ONi65VgnJbvTeO30GI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=TGLVT9nF; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TGLVT9nF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1730387218; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=zW1p1Hk2ATUzKb/rrzNSAt+zs2hNmejNsvS9zd6KgUs=; b=TGLVT9nF8D3bZw5ecsNNfpVguzPl9qls3N9isKVV0nAHYJYFlpqRJpb+4d1ImUZKN9okIA iVgguAfd9FoG4jd9oXTaBjTxmI+/wFtC+0BhUkJjBVNb5YVVaLal8O81joldOAJVYaTE/j HQuHiDQGxZhgOhTOzoG+Szo8wSPmRpc= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-643-6H7ozxj9PNi7pSjP5mZ0Pg-1; Thu, 31 Oct 2024 11:06:53 -0400 X-MC-Unique: 6H7ozxj9PNi7pSjP5mZ0Pg-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 058B019540F3; Thu, 31 Oct 2024 15:06:51 +0000 (UTC) Received: from bcodding.csb.redhat.com (unknown [10.22.58.17]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id C9EF919560A2; Thu, 31 Oct 2024 15:06:49 +0000 (UTC) From: Benjamin Coddington To: Alasdair Kergon , Mike Snitzer , Mikulas Patocka Cc: Christoph Hellwig , dm-devel@lists.linux.dev, linux-nfs@vger.kernel.org Subject: [PATCH v2] dm: add support for get_unique_id Date: Thu, 31 Oct 2024 11:06:48 -0400 Message-ID: <701894fdf55ce2cb379eb26f6ee0536f96103ab9.1730387019.git.bcodding@redhat.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 This adds support to obtain a device's unique id through dm, similar to the existing ioctl and persistent resevation handling. We limit this to single-target devices. This enables knfsd to export pNFS SCSI luns that have been exported from multipath devices. Signed-off-by: Benjamin Coddington Reviewed-by: Christoph Hellwig --- V2: style, add a comment about sanity, strip "uuid" from variable names --- drivers/md/dm.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) base-commit: 98f7e32f20d28ec452afb208f9cffc08448a2652 diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 87bb90303435..ee97e23ffffc 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -3342,6 +3342,59 @@ void dm_free_md_mempools(struct dm_md_mempools *pools) kfree(pools); } +struct dm_blkdev_id { + u8 *id; + enum blk_unique_id type; +}; + +static int __dm_get_unique_id(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + struct dm_blkdev_id *dm_id = data; + const struct block_device_operations *fops = dev->bdev->bd_disk->fops; + + if (!fops->get_unique_id) + return 0; + + return fops->get_unique_id(dev->bdev->bd_disk, dm_id->id, dm_id->type); +} + +/* + * Allow access to get_unique_id() for the first device returning a + * non-zero result. Reasonable use expects all devices to have the + * same unique id. + */ +static int dm_blk_get_unique_id(struct gendisk *disk, u8 *id, + enum blk_unique_id type) +{ + struct mapped_device *md = disk->private_data; + struct dm_table *table; + struct dm_target *ti; + int ret = 0, srcu_idx; + + struct dm_blkdev_id dm_id = { + .id = id, + .type = type, + }; + + table = dm_get_live_table(md, &srcu_idx); + if (!table || !dm_table_get_size(table)) + goto out; + + /* We only support devices that have a single target */ + if (table->num_targets != 1) + goto out; + ti = dm_table_get_target(table, 0); + + if (!ti->type->iterate_devices) + goto out; + + ret = ti->type->iterate_devices(ti, __dm_get_unique_id, &dm_id); +out: + dm_put_live_table(md, srcu_idx); + return ret; +} + struct dm_pr { u64 old_key; u64 new_key; @@ -3667,6 +3720,7 @@ static const struct block_device_operations dm_blk_dops = { .ioctl = dm_blk_ioctl, .getgeo = dm_blk_getgeo, .report_zones = dm_blk_report_zones, + .get_unique_id = dm_blk_get_unique_id, .pr_ops = &dm_pr_ops, .owner = THIS_MODULE }; @@ -3676,6 +3730,7 @@ static const struct block_device_operations dm_rq_blk_dops = { .release = dm_blk_close, .ioctl = dm_blk_ioctl, .getgeo = dm_blk_getgeo, + .get_unique_id = dm_blk_get_unique_id, .pr_ops = &dm_pr_ops, .owner = THIS_MODULE };