From patchwork Fri Jul 30 08:52:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shiyang Ruan X-Patchwork-Id: 12410773 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 BAEDAC4320A for ; Fri, 30 Jul 2021 08:53:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7923561008 for ; Fri, 30 Jul 2021 08:53:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 7923561008 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=fujitsu.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 22E178E0006; Fri, 30 Jul 2021 04:53:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1DF958E0001; Fri, 30 Jul 2021 04:53:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0A5C78E0006; Fri, 30 Jul 2021 04:53:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0050.hostedemail.com [216.40.44.50]) by kanga.kvack.org (Postfix) with ESMTP id E57968E0001 for ; Fri, 30 Jul 2021 04:53:19 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 9CD1C1801AB66 for ; Fri, 30 Jul 2021 08:53:19 +0000 (UTC) X-FDA: 78418640118.16.F651E4E Received: from heian.cn.fujitsu.com (mail.cn.fujitsu.com [183.91.158.132]) by imf11.hostedemail.com (Postfix) with ESMTP id D18A8F002437 for ; Fri, 30 Jul 2021 08:53:18 +0000 (UTC) IronPort-HdrOrdr: A9a23:o0+aGqEyNqzg/l7+pLqEDMeALOsnbusQ8zAXP0AYc3Jom6uj5qaTdZUgpGbJYVkqOE3I9ertBEDEewK4yXcX2/h3AV7BZniEhILAFugLhuGO/9SjIVybygc378ZdmsZFZ+EYdWIK7/oS/jPIbuoI8Z2W9ryyn+fCwzNIRQFuUatp6AB0EW+gYzZLbTgDFZwkD4Cd+8YCgzKhfE4cZsO9CmJAcPPEo7Tw5ejbSC9DFxg68xOPkD/tzLb7FiKT1hAYXygK4ZpKyxm8rzDE X-IronPort-AV: E=Sophos;i="5.84,281,1620662400"; d="scan'208";a="112070621" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 30 Jul 2021 16:53:17 +0800 Received: from G08CNEXMBPEKD04.g08.fujitsu.local (unknown [10.167.33.201]) by cn.fujitsu.com (Postfix) with ESMTP id A98A04D0D49B; Fri, 30 Jul 2021 16:53:12 +0800 (CST) Received: from G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.85) by G08CNEXMBPEKD04.g08.fujitsu.local (10.167.33.201) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Fri, 30 Jul 2021 16:53:13 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.23 via Frontend Transport; Fri, 30 Jul 2021 16:53:11 +0800 From: Shiyang Ruan To: , , , , , CC: , , , , , Subject: [PATCH v6 7/9] dm: Introduce ->rmap() to find bdev offset Date: Fri, 30 Jul 2021 16:52:43 +0800 Message-ID: <20210730085245.3069812-8-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210730085245.3069812-1-ruansy.fnst@fujitsu.com> References: <20210730085245.3069812-1-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: A98A04D0D49B.A2416 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com Authentication-Results: imf11.hostedemail.com; dkim=none; spf=none (imf11.hostedemail.com: domain of ruansy.fnst@fujitsu.com has no SPF policy when checking 183.91.158.132) smtp.mailfrom=ruansy.fnst@fujitsu.com; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=fujitsu.com (policy=none) X-Rspamd-Server: rspam02 X-Stat-Signature: nbypgx5kxmkjqtb7g3y6zjic44wpkpdk X-Rspamd-Queue-Id: D18A8F002437 X-HE-Tag: 1627635198-891969 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Pmem device could be a target of mapped device. In order to find out the global location on a mapped device, we introduce this to translate offset from target device to mapped device. Currently, we implement it on linear target, which is easy to do the translation. Other targets will be supported in the future. However, some targets may not support it because of the non-linear mapping. Signed-off-by: Shiyang Ruan --- block/genhd.c | 56 +++++++++++++++++++++++++++++++++++ drivers/md/dm-linear.c | 20 +++++++++++++ include/linux/device-mapper.h | 5 ++++ include/linux/genhd.h | 1 + 4 files changed, 82 insertions(+) diff --git a/block/genhd.c b/block/genhd.c index af4d2ab4a633..7a595da0cbec 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -669,6 +669,62 @@ void blk_request_module(dev_t devt) request_module("block-major-%d", MAJOR(devt)); } +/* + * bdget_disk - do bdget() by gendisk and partition number + * @disk: gendisk of interest + * @partno: partition number + * + * Find partition @partno from @disk, do bdget() on it. + * + * CONTEXT: + * Don't care. + * + * RETURNS: + * Resulting block_device on success, NULL on failure. + */ +static inline struct block_device *bdget_disk(struct gendisk *disk, int partno) +{ + struct block_device *bdev = NULL; + + rcu_read_lock(); + bdev = xa_load(&disk->part_tbl, partno); + if (bdev && !bdgrab(bdev)) + bdev = NULL; + rcu_read_unlock(); + + return bdev; +} + +/** + * bdget_disk_sector - get block device by given sector number + * @disk: gendisk of interest + * @sector: sector number + * + * RETURNS: the found block device where sector locates in + */ +struct block_device *bdget_disk_sector(struct gendisk *disk, sector_t sector) +{ + struct block_device *part = NULL, *p; + unsigned long idx; + + rcu_read_lock(); + xa_for_each(&disk->part_tbl, idx, p) { + if (p->bd_partno == 0) + continue; + if (p->bd_start_sect <= sector && + sector < p->bd_start_sect + bdev_nr_sectors(p)) { + part = p; + break; + } + } + rcu_read_unlock(); + if (!part) + part = disk->part0; + + return bdget_disk(disk, part->bd_partno); +} +EXPORT_SYMBOL(bdget_disk_sector); + /* * print a full list of all partitions - intended for places where the root * filesystem can't be mounted and thus to give the victim some idea of what diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index c91f1e2e2f65..d28577bd358b 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -5,6 +5,7 @@ */ #include "dm.h" +#include "dm-core.h" #include #include #include @@ -119,6 +120,24 @@ static void linear_status(struct dm_target *ti, status_type_t type, } } +static int linear_rmap(struct dm_target *ti, sector_t offset, + rmap_callout_fn fn, void *data) +{ + struct linear_c *lc = (struct linear_c *) ti->private; + struct mapped_device *md = ti->table->md; + struct block_device *bdev; + sector_t disk_sect = offset - dm_target_offset(ti, lc->start); + int rc = -ENODEV; + + bdev = bdget_disk_sector(md->disk, offset); + if (!bdev) + return rc; + + rc = fn(ti, bdev, disk_sect, data); + bdput(bdev); + return rc; +} + static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev) { struct linear_c *lc = (struct linear_c *) ti->private; @@ -235,6 +254,7 @@ static struct target_type linear_target = { .ctr = linear_ctr, .dtr = linear_dtr, .map = linear_map, + .rmap = linear_rmap, .status = linear_status, .prepare_ioctl = linear_prepare_ioctl, .iterate_devices = linear_iterate_devices, diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 7457d49acf9a..4069983c4618 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -58,6 +58,10 @@ typedef void (*dm_dtr_fn) (struct dm_target *ti); * = 2: The target wants to push back the io */ typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio); +typedef int (*rmap_callout_fn) (struct dm_target *ti, struct block_device *bdev, + sector_t sect, void *data); +typedef int (*dm_rmap_fn) (struct dm_target *ti, sector_t offset, + rmap_callout_fn fn, void *data); typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti, struct request *rq, union map_info *map_context, @@ -184,6 +188,7 @@ struct target_type { dm_ctr_fn ctr; dm_dtr_fn dtr; dm_map_fn map; + dm_rmap_fn rmap; dm_clone_and_map_request_fn clone_and_map_rq; dm_release_clone_request_fn release_clone_rq; dm_endio_fn end_io; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 13b34177cc85..7de6fdc14de6 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -223,6 +223,7 @@ static inline void add_disk_no_queue_reg(struct gendisk *disk) } extern void del_gendisk(struct gendisk *gp); +extern struct block_device *bdget_disk_sector(struct gendisk *disk, sector_t sector); void set_disk_ro(struct gendisk *disk, bool read_only);