From patchwork Wed Feb 3 15:53:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergei Shtepa X-Patchwork-Id: 12064677 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5A13C433E6 for ; Wed, 3 Feb 2021 15:57:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1F0B64F65 for ; Wed, 3 Feb 2021 15:57:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234485AbhBCP47 (ORCPT ); Wed, 3 Feb 2021 10:56:59 -0500 Received: from mx2.veeam.com ([64.129.123.6]:56872 "EHLO mx2.veeam.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234691AbhBCP4v (ORCPT ); Wed, 3 Feb 2021 10:56:51 -0500 Received: from mail.veeam.com (prgmbx01.amust.local [172.24.0.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx2.veeam.com (Postfix) with ESMTPS id ACD584159C; Wed, 3 Feb 2021 10:54:48 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=veeam.com; s=mx2; t=1612367689; bh=fypuNIL3IiNG+w81W5Dyl+Eq2Mzu4AwDcNRA7TfznU8=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=cxI7i634PPasqV6DLURmXOJJqhrXuLeysJ9B3gPfpxaXTQkM/YBbVlzFMIl4Hpbyo z4eWQFWAdBYGTUanojepPUm7BUg91SdQtZe0w9G/X7VQeRgVfLPQvsl7Wsy/xkHZBQ nU1XJ+bWo0no6GrucgLcEKKWNEs6FzNWLBq93l8k= Received: from prgdevlinuxpatch01.amust.local (172.24.14.5) by prgmbx01.amust.local (172.24.0.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2; Wed, 3 Feb 2021 16:54:26 +0100 From: Sergei Shtepa To: , , , , , , , , , , , , , , , CC: , Subject: [PATCH v4 5/6] dm: add 'noexcl' option for dm-linear Date: Wed, 3 Feb 2021 18:53:57 +0300 Message-ID: <1612367638-3794-6-git-send-email-sergei.shtepa@veeam.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1612367638-3794-1-git-send-email-sergei.shtepa@veeam.com> References: <1612367638-3794-1-git-send-email-sergei.shtepa@veeam.com> MIME-Version: 1.0 X-Originating-IP: [172.24.14.5] X-ClientProxiedBy: prgmbx02.amust.local (172.24.0.172) To prgmbx01.amust.local (172.24.0.171) X-EsetResult: clean, is OK X-EsetId: 37303A29C604D265667062 X-Veeam-MMEX: True Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The 'noexcl' option allow to open underlying block-device without FMODE_EXCL. Signed-off-by: Sergei Shtepa --- drivers/md/dm-linear.c | 14 +++++++++++++- drivers/md/dm-table.c | 12 +++++++----- drivers/md/dm.c | 24 +++++++++++++++++------- drivers/md/dm.h | 2 +- include/linux/device-mapper.h | 7 +++++++ 5 files changed, 45 insertions(+), 14 deletions(-) diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index 00774b5d7668..b16d89802b9d 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -33,7 +33,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv) char dummy; int ret; - if (argc != 2) { + if ((argc < 2) || (argc > 3)) { ti->error = "Invalid argument count"; return -EINVAL; } @@ -51,6 +51,18 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv) } lc->start = tmp; + ti->non_exclusive = false; + if (argc > 2) { + if (strcmp("noexcl", argv[2]) == 0) + ti->non_exclusive = true; + else if (strcmp("excl", argv[2]) == 0) + ti->non_exclusive = false; + else { + ti->error = "Invalid exclusive option"; + return -EINVAL; + } + } + ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev); if (ret) { ti->error = "Device lookup failed"; diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 4acf2342f7ad..f15bc2171f25 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -322,7 +322,7 @@ static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev, * device and not to touch the existing bdev field in case * it is accessed concurrently. */ -static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode, +static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode, bool non_exclusive, struct mapped_device *md) { int r; @@ -330,7 +330,7 @@ static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode, old_dev = dd->dm_dev; - r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev, + r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev, non_exclusive, dd->dm_dev->mode | new_mode, &new_dev); if (r) return r; @@ -387,7 +387,8 @@ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, if (!dd) return -ENOMEM; - if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) { + r = dm_get_table_device(t->md, dev, mode, ti->non_exclusive, &dd->dm_dev); + if (r) { kfree(dd); return r; } @@ -396,8 +397,9 @@ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, list_add(&dd->list, &t->devices); goto out; - } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) { - r = upgrade_mode(dd, mode, t->md); + } else if ((dd->dm_dev->mode != (mode | dd->dm_dev->mode)) && + (dd->dm_dev->non_exclusive != ti->non_exclusive)) { + r = upgrade_mode(dd, mode, ti->non_exclusive, t->md); if (r) return r; } diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 0b184dfec233..c34c75467399 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1107,6 +1107,7 @@ static int open_table_device(struct table_device *td, dev_t dev, td->dm_dev.bdev = bdev; td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); + td->dm_dev.non_exclusive = non_exclusive; return 0; } @@ -1118,33 +1119,41 @@ static void close_table_device(struct table_device *td, struct mapped_device *md if (!td->dm_dev.bdev) return; - bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md)); - blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL); + if (td->dm_dev.non_exclusive) + blkdev_put(td->dm_dev.bdev, td->dm_dev.mode); + else { + bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md)); + blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL); + } + put_dax(td->dm_dev.dax_dev); td->dm_dev.bdev = NULL; td->dm_dev.dax_dev = NULL; + td->dm_dev.non_exclusive = false; } static struct table_device *find_table_device(struct list_head *l, dev_t dev, - fmode_t mode) + fmode_t mode, bool non_exclusive) { struct table_device *td; list_for_each_entry(td, l, list) - if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode) + if (td->dm_dev.bdev->bd_dev == dev && + td->dm_dev.mode == mode && + td->dm_dev.non_exclusive == non_exclusive) return td; return NULL; } -int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, +int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, bool non_exclusive, struct dm_dev **result) { int r; struct table_device *td; mutex_lock(&md->table_devices_lock); - td = find_table_device(&md->table_devices, dev, mode); + td = find_table_device(&md->table_devices, dev, mode, non_exclusive); if (!td) { td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id); if (!td) { @@ -1155,7 +1164,8 @@ int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, td->dm_dev.mode = mode; td->dm_dev.bdev = NULL; - if ((r = open_table_device(td, dev, md))) { + r = open_table_device(td, dev, md, non_exclusive); + if (r) { mutex_unlock(&md->table_devices_lock); kfree(td); return r; diff --git a/drivers/md/dm.h b/drivers/md/dm.h index fffe1e289c53..7bf20fb2de74 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -179,7 +179,7 @@ int dm_open_count(struct mapped_device *md); int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); int dm_cancel_deferred_remove(struct mapped_device *md); int dm_request_based(struct mapped_device *md); -int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, +int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, bool non_exclusive, struct dm_dev **result); void dm_put_table_device(struct mapped_device *md, struct dm_dev *d); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 61a66fb8ebb3..70002363bfc0 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -150,6 +150,7 @@ struct dm_dev { struct block_device *bdev; struct dax_device *dax_dev; fmode_t mode; + bool non_exclusive; char name[16]; }; @@ -325,6 +326,12 @@ struct dm_target { * whether or not its underlying devices have support. */ bool discards_supported:1; + + /* + * Set if this target needs to open device without FMODE_EXCL + * mode. + */ + bool non_exclusive:1; }; void *dm_per_bio_data(struct bio *bio, size_t data_size);