From patchwork Mon Jun 28 00:02:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shiyang Ruan X-Patchwork-Id: 12347151 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 85EFDC49EAF for ; Mon, 28 Jun 2021 00:03:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 36660619F1 for ; Mon, 28 Jun 2021 00:03:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36660619F1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fujitsu.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 799F28D0013; Sun, 27 Jun 2021 20:03:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7490C8D0012; Sun, 27 Jun 2021 20:03:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 59E708D0013; Sun, 27 Jun 2021 20:03:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0175.hostedemail.com [216.40.44.175]) by kanga.kvack.org (Postfix) with ESMTP id 1D6638D0012 for ; Sun, 27 Jun 2021 20:03:17 -0400 (EDT) Received: from smtpin40.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0A8A018F71 for ; Mon, 28 Jun 2021 00:03:17 +0000 (UTC) X-FDA: 78301182834.40.6B61736 Received: from heian.cn.fujitsu.com (mail.cn.fujitsu.com [183.91.158.132]) by imf18.hostedemail.com (Postfix) with ESMTP id 1D37E200107C for ; Mon, 28 Jun 2021 00:03:15 +0000 (UTC) IronPort-HdrOrdr: A9a23:wNdcXaFyDuleE1rBpLqEDseALOsnbusQ8zAXP0AYc31om6uj5rmTdZUgpGfJYVkqKRIdcLy7V5VoBEmskaKdgrNhW4tKPjOW2ldARbsKheCJrlHd8m/Fh4lgPMxbE5SWZuefMbEDt7ee3OCnKadd/PC3tLCvmfzFz2pgCSVja6Rb5Q9/DQqBe3cGPjVuNN4oEoaG/Mpbq36FcXQTVM6yAX4IRKztvNvO/aiWHCIuNlo27hWUlzO05PrfGxic5B0XVDRC2vMD3AH+4nfE2pk= X-IronPort-AV: E=Sophos;i="5.83,304,1616428800"; d="scan'208";a="110256365" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 28 Jun 2021 08:03:15 +0800 Received: from G08CNEXMBPEKD05.g08.fujitsu.local (unknown [10.167.33.204]) by cn.fujitsu.com (Postfix) with ESMTP id 862014C36A09; Mon, 28 Jun 2021 08:03:11 +0800 (CST) Received: from G08CNEXCHPEKD07.g08.fujitsu.local (10.167.33.80) by G08CNEXMBPEKD05.g08.fujitsu.local (10.167.33.204) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 28 Jun 2021 08:03:12 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD07.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 28 Jun 2021 08:03:12 +0800 From: Shiyang Ruan To: , , , , , CC: , , , , , , Subject: [PATCH v5 7/9] dm: Introduce ->rmap() to find bdev offset Date: Mon, 28 Jun 2021 08:02:16 +0800 Message-ID: <20210628000218.387833-8-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210628000218.387833-1-ruansy.fnst@fujitsu.com> References: <20210628000218.387833-1-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: 862014C36A09.AF525 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 1D37E200107C X-Stat-Signature: eg6cj4uik7p5ki557yg4rf9c369wproj Authentication-Results: imf18.hostedemail.com; dkim=none; spf=neutral (imf18.hostedemail.com: 183.91.158.132 is neither permitted nor denied by domain of ruansy.fnst@fujitsu.com) smtp.mailfrom=ruansy.fnst@fujitsu.com; dmarc=none X-HE-Tag: 1624838595-951353 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 | 30 ++++++++++++++++++++++++++++++ drivers/md/dm-linear.c | 20 ++++++++++++++++++++ include/linux/device-mapper.h | 5 +++++ include/linux/genhd.h | 1 + 4 files changed, 56 insertions(+) -- 2.32.0 diff --git a/block/genhd.c b/block/genhd.c index 9f8cb7beaad1..75834bd057df 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -718,6 +718,36 @@ struct block_device *bdget_disk(struct gendisk *disk, int partno) 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 92db0f5e7f28..f9f9bc765ba7 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; @@ -236,6 +255,7 @@ 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 ff700fb6ce1d..89a893565407 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 6fc26f7bdf71..2ad70c02c343 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -219,6 +219,7 @@ static inline void add_disk_no_queue_reg(struct gendisk *disk) extern void del_gendisk(struct gendisk *gp); extern struct block_device *bdget_disk(struct gendisk *disk, int partno); +extern struct block_device *bdget_disk_sector(struct gendisk *disk, sector_t sector); void set_disk_ro(struct gendisk *disk, bool read_only);