From patchwork Wed Oct 27 02:22:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 12586157 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 253E2C4332F for ; Wed, 27 Oct 2021 02:22:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09BFA60E0B for ; Wed, 27 Oct 2021 02:22:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238172AbhJ0CYw (ORCPT ); Tue, 26 Oct 2021 22:24:52 -0400 Received: from esa5.hgst.iphmx.com ([216.71.153.144]:63763 "EHLO esa5.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236505AbhJ0CYv (ORCPT ); Tue, 26 Oct 2021 22:24:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1635301346; x=1666837346; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=/1tPoHxyMjcQpEugjH7G7FAPPmLdkLphhCbwGTwC+4M=; b=bIqLZykzYSu4Ny2a3QfcXIMUXsCzxfkY9vdIsNt2CTUO2Wltax4xvJjm QFcxnAkmVxGQEHayY1iotGC/6EiDzY1Fyu32F6O//epvguwnTn5Go7bzM n5xzK81qQasZjrq+6OvTBWw0gmNQFj2mowh/XXp1UKXsxYNWeUv4xc0AF 8DOg0VofkIjfXNqiawGHuocmx1h0KcIzZIFS+iBoZaOwxNvTdXJfsAR2x bJx9tGgD7nTc5ij3GthKDd+AP8kb0Lv+O5sSrwVMswstTn5uIX76kIOPV ryj0/VEd5viSeWqus8S3I15BTKQaD0A8PMY0GBGnmy709sgAwOe8y4Du7 g==; X-IronPort-AV: E=Sophos;i="5.87,184,1631548800"; d="scan'208";a="183924735" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 27 Oct 2021 10:22:25 +0800 IronPort-SDR: 8GhNjQKBeR4ohYJAm9zBCnLSyjNxMF5CxY2Z8Jev6O25XnrQZM7/+TOgobnk550MwITE4SwlQy xJ3PKuNLxwYNndVqEFCHE+dSwotLUkeT4NQjh0u9ZDnOJAHtjJwxP+nYTDToaH86c3byxJ3TtX 2oLOW6gvG45gNtRackmuy+Lq2TOX/dW367Vk+MMajeEl0L8ayQBmFj8YOSUmyxOkv7/7plXgXU NiaUJU+EBmGMVrHandXp1AZsOTKZL9IDNe4y2u4j7lGdn01J/9G80nsOo2/+EE1O+2NSxoN6PW Mf/rw7ZRTwJg8DNkHn+jcYc+ Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Oct 2021 18:57:55 -0700 IronPort-SDR: dKdRpkQhRNgLVnCo2YzQAHIT1yRPjnEd8zUmLF7FlZGjrh0JGM2YAe8CHxQp8muJZVJEucEDfO iF2c7vwLIHZ4/3O/I5ghwUqaXeZhC1yfaouqvdxfEC47kSH6KmFZ523q4ntpHfUBgbU8gzjDIk cQrMqQO9+h5+mKSMteSPliZT0qUCsD0vdGM5HjWT9GasMC7lwWpH4rzf/mKrMROj9r5e2H/X2e yCkUoEpZmzLXU9YqhQuGuZzLXBujyrCn4aT5Jqx5F1PvH3vD4yhz1xt+sVoM/0lCqcjQ46KlkU i64= WDCIronportException: Internal Received: from washi.fujisawa.hgst.com ([10.149.53.254]) by uls-op-cesaip02.wdc.com with ESMTP; 26 Oct 2021 19:22:26 -0700 From: Damien Le Moal To: Jens Axboe , linux-block@vger.kernel.org, linux-ide@vger.kernel.org, "Martin K . Petersen" , linux-scsi@vger.kernel.org Subject: [PATCH v9 1/5] block: Add independent access ranges support Date: Wed, 27 Oct 2021 11:22:19 +0900 Message-Id: <20211027022223.183838-2-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211027022223.183838-1-damien.lemoal@wdc.com> References: <20211027022223.183838-1-damien.lemoal@wdc.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The Concurrent Positioning Ranges VPD page (for SCSI) and data log page (for ATA) contain parameters describing the set of contiguous LBAs that can be served independently by a single LUN multi-actuator hard-disk. Similarly, a logically defined block device composed of multiple disks can in some cases execute requests directed at different sector ranges in parallel. A dm-linear device aggregating 2 block devices together is an example. This patch implements support for exposing a block device independent access ranges to the user through sysfs to allow optimizing device accesses to increase performance. To describe the set of independent sector ranges of a device (actuators of a multi-actuator HDDs or table entries of a dm-linear device), The type struct blk_independent_access_ranges is introduced. This structure describes the sector ranges using an array of struct blk_independent_access_range structures. This range structure defines the start sector and number of sectors of the access range. The ranges in the array cannot overlap and must contain all sectors within the device capacity. The function disk_set_independent_access_ranges() allows a device driver to signal to the block layer that a device has multiple independent access ranges. In this case, a struct blk_independent_access_ranges is attached to the device request queue by the function disk_set_independent_access_ranges(). The function disk_alloc_independent_access_ranges() is provided for drivers to allocate this structure. struct blk_independent_access_ranges contains kobjects (struct kobject) to expose to the user through sysfs the set of independent access ranges supported by a device. When the device is initialized, sysfs registration of the ranges information is done from blk_register_queue() using the block layer internal function disk_register_independent_access_ranges(). If a driver calls disk_set_independent_access_ranges() for a registered queue, e.g. when a device is revalidated, disk_set_independent_access_ranges() will execute disk_register_independent_access_ranges() to update the sysfs attribute files. The sysfs file structure created starts from the independent_access_ranges sub-directory and contains the start sector and number of sectors of each range, with the information for each range grouped in numbered sub-directories. E.g. for a dual actuator HDD, the user sees: $ tree /sys/block/sdk/queue/independent_access_ranges/ /sys/block/sdk/queue/independent_access_ranges/ |-- 0 | |-- nr_sectors | `-- sector `-- 1 |-- nr_sectors `-- sector For a regular device with a single access range, the independent_access_ranges sysfs directory does not exist. Device revalidation may lead to changes to this structure and to the attribute values. When manipulated, the queue sysfs_lock and sysfs_dir_lock mutexes are held for atomicity, similarly to how the blk-mq and elevator sysfs queue sub-directories are protected. The code related to the management of independent access ranges is added in the new file block/blk-ia-ranges.c. Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Martin K. Petersen Reviewed-by: Keith Busch --- block/Makefile | 2 +- block/blk-ia-ranges.c | 348 +++++++++++++++++++++++++++++++++++++++++ block/blk-sysfs.c | 26 ++- block/blk.h | 4 + include/linux/blkdev.h | 39 +++++ 5 files changed, 410 insertions(+), 9 deletions(-) create mode 100644 block/blk-ia-ranges.c diff --git a/block/Makefile b/block/Makefile index 602f7f47b7b6..44df57e562bf 100644 --- a/block/Makefile +++ b/block/Makefile @@ -9,7 +9,7 @@ obj-y := bdev.o fops.o bio.o elevator.o blk-core.o blk-sysfs.o \ blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \ blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \ genhd.o ioprio.o badblocks.o partitions/ blk-rq-qos.o \ - disk-events.o + disk-events.o blk-ia-ranges.o obj-$(CONFIG_BOUNCE) += bounce.o obj-$(CONFIG_BLK_DEV_BSG_COMMON) += bsg.o diff --git a/block/blk-ia-ranges.c b/block/blk-ia-ranges.c new file mode 100644 index 000000000000..c246c425d0d7 --- /dev/null +++ b/block/blk-ia-ranges.c @@ -0,0 +1,348 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Block device concurrent positioning ranges. + * + * Copyright (C) 2021 Western Digital Corporation or its Affiliates. + */ +#include +#include +#include +#include + +#include "blk.h" + +static ssize_t +blk_ia_range_sector_show(struct blk_independent_access_range *iar, + char *buf) +{ + return sprintf(buf, "%llu\n", iar->sector); +} + +static ssize_t +blk_ia_range_nr_sectors_show(struct blk_independent_access_range *iar, + char *buf) +{ + return sprintf(buf, "%llu\n", iar->nr_sectors); +} + +struct blk_ia_range_sysfs_entry { + struct attribute attr; + ssize_t (*show)(struct blk_independent_access_range *iar, char *buf); +}; + +static struct blk_ia_range_sysfs_entry blk_ia_range_sector_entry = { + .attr = { .name = "sector", .mode = 0444 }, + .show = blk_ia_range_sector_show, +}; + +static struct blk_ia_range_sysfs_entry blk_ia_range_nr_sectors_entry = { + .attr = { .name = "nr_sectors", .mode = 0444 }, + .show = blk_ia_range_nr_sectors_show, +}; + +static struct attribute *blk_ia_range_attrs[] = { + &blk_ia_range_sector_entry.attr, + &blk_ia_range_nr_sectors_entry.attr, + NULL, +}; +ATTRIBUTE_GROUPS(blk_ia_range); + +static ssize_t blk_ia_range_sysfs_show(struct kobject *kobj, + struct attribute *attr, char *buf) +{ + struct blk_ia_range_sysfs_entry *entry = + container_of(attr, struct blk_ia_range_sysfs_entry, attr); + struct blk_independent_access_range *iar = + container_of(kobj, struct blk_independent_access_range, kobj); + ssize_t ret; + + mutex_lock(&iar->queue->sysfs_lock); + ret = entry->show(iar, buf); + mutex_unlock(&iar->queue->sysfs_lock); + + return ret; +} + +static const struct sysfs_ops blk_ia_range_sysfs_ops = { + .show = blk_ia_range_sysfs_show, +}; + +/* + * Independent access range entries are not freed individually, but alltogether + * with struct blk_independent_access_ranges and its array of ranges. Since + * kobject_add() takes a reference on the parent kobject contained in + * struct blk_independent_access_ranges, the array of independent access range + * entries cannot be freed until kobject_del() is called for all entries. + * So we do not need to do anything here, but still need this no-op release + * operation to avoid complaints from the kobject code. + */ +static void blk_ia_range_sysfs_nop_release(struct kobject *kobj) +{ +} + +static struct kobj_type blk_ia_range_ktype = { + .sysfs_ops = &blk_ia_range_sysfs_ops, + .default_groups = blk_ia_range_groups, + .release = blk_ia_range_sysfs_nop_release, +}; + +/* + * This will be executed only after all independent access range entries are + * removed with kobject_del(), at which point, it is safe to free everything, + * including the array of ranges. + */ +static void blk_ia_ranges_sysfs_release(struct kobject *kobj) +{ + struct blk_independent_access_ranges *iars = + container_of(kobj, struct blk_independent_access_ranges, kobj); + + kfree(iars); +} + +static struct kobj_type blk_ia_ranges_ktype = { + .release = blk_ia_ranges_sysfs_release, +}; + +/** + * disk_register_ia_ranges - register with sysfs a set of independent + * access ranges + * @disk: Target disk + * @new_iars: New set of independent access ranges + * + * Register with sysfs a set of independent access ranges for @disk. + * If @new_iars is not NULL, this set of ranges is registered and the old set + * specified by q->ia_ranges is unregistered. Otherwise, q->ia_ranges is + * registered if it is not already. + */ +int disk_register_independent_access_ranges(struct gendisk *disk, + struct blk_independent_access_ranges *new_iars) +{ + struct request_queue *q = disk->queue; + struct blk_independent_access_ranges *iars; + int i, ret; + + lockdep_assert_held(&q->sysfs_dir_lock); + lockdep_assert_held(&q->sysfs_lock); + + /* If a new range set is specified, unregister the old one */ + if (new_iars) { + if (q->ia_ranges) + disk_unregister_independent_access_ranges(disk); + q->ia_ranges = new_iars; + } + + iars = q->ia_ranges; + if (!iars) + return 0; + + /* + * At this point, iars is the new set of sector access ranges that needs + * to be registered with sysfs. + */ + WARN_ON(iars->sysfs_registered); + ret = kobject_init_and_add(&iars->kobj, &blk_ia_ranges_ktype, + &q->kobj, "%s", "independent_access_ranges"); + if (ret) { + q->ia_ranges = NULL; + kfree(iars); + return ret; + } + + for (i = 0; i < iars->nr_ia_ranges; i++) { + iars->ia_range[i].queue = q; + ret = kobject_init_and_add(&iars->ia_range[i].kobj, + &blk_ia_range_ktype, &iars->kobj, + "%d", i); + if (ret) { + while (--i >= 0) + kobject_del(&iars->ia_range[i].kobj); + kobject_del(&iars->kobj); + kobject_put(&iars->kobj); + return ret; + } + } + + iars->sysfs_registered = true; + + return 0; +} + +void disk_unregister_independent_access_ranges(struct gendisk *disk) +{ + struct request_queue *q = disk->queue; + struct blk_independent_access_ranges *iars = q->ia_ranges; + int i; + + lockdep_assert_held(&q->sysfs_dir_lock); + lockdep_assert_held(&q->sysfs_lock); + + if (!iars) + return; + + if (iars->sysfs_registered) { + for (i = 0; i < iars->nr_ia_ranges; i++) + kobject_del(&iars->ia_range[i].kobj); + kobject_del(&iars->kobj); + kobject_put(&iars->kobj); + } else { + kfree(iars); + } + + q->ia_ranges = NULL; +} + +static struct blk_independent_access_range * +disk_find_ia_range(struct blk_independent_access_ranges *iars, + sector_t sector) +{ + struct blk_independent_access_range *iar; + int i; + + for (i = 0; i < iars->nr_ia_ranges; i++) { + iar = &iars->ia_range[i]; + if (sector >= iar->sector && + sector < iar->sector + iar->nr_sectors) + return iar; + } + + return NULL; +} + +static bool disk_check_ia_ranges(struct gendisk *disk, + struct blk_independent_access_ranges *iars) +{ + struct blk_independent_access_range *iar, *tmp; + sector_t capacity = get_capacity(disk); + sector_t sector = 0; + int i; + + /* + * While sorting the ranges in increasing LBA order, check that the + * ranges do not overlap, that there are no sector holes and that all + * sectors belong to one range. + */ + for (i = 0; i < iars->nr_ia_ranges; i++) { + tmp = disk_find_ia_range(iars, sector); + if (!tmp || tmp->sector != sector) { + pr_warn("Invalid non-contiguous independent access ranges\n"); + return false; + } + + iar = &iars->ia_range[i]; + if (tmp != iar) { + swap(iar->sector, tmp->sector); + swap(iar->nr_sectors, tmp->nr_sectors); + } + + sector += iar->nr_sectors; + } + + if (sector != capacity) { + pr_warn("Independent access ranges do not match disk capacity\n"); + return false; + } + + return true; +} + +static bool disk_ia_ranges_changed(struct gendisk *disk, + struct blk_independent_access_ranges *new) +{ + struct blk_independent_access_ranges *old = disk->queue->ia_ranges; + int i; + + if (!old) + return true; + + if (old->nr_ia_ranges != new->nr_ia_ranges) + return true; + + for (i = 0; i < old->nr_ia_ranges; i++) { + if (new->ia_range[i].sector != old->ia_range[i].sector || + new->ia_range[i].nr_sectors != old->ia_range[i].nr_sectors) + return true; + } + + return false; +} + +/** + * disk_alloc_independent_access_ranges - Allocate an independent access ranges + * data structure + * @disk: target disk + * @nr_ia_ranges: Number of independent access ranges + * + * Allocate a struct blk_independent_access_ranges structure with @nr_ia_ranges + * access range descriptors. + */ +struct blk_independent_access_ranges * +disk_alloc_independent_access_ranges(struct gendisk *disk, int nr_ia_ranges) +{ + struct blk_independent_access_ranges *iars; + + iars = kzalloc_node(struct_size(iars, ia_range, nr_ia_ranges), + GFP_KERNEL, disk->queue->node); + if (iars) + iars->nr_ia_ranges = nr_ia_ranges; + return iars; +} +EXPORT_SYMBOL_GPL(disk_alloc_independent_access_ranges); + +/** + * disk_set_independent_access_ranges - Set a disk independent access ranges + * @disk: target disk + * @iars: independent access ranges structure + * + * Set the independent access ranges information of the request queue + * of @disk to @iars. If @iars is NULL and the independent access ranges + * structure already set is cleared. If there are no differences between + * @iars and the independent access ranges structure already set, @iars + * is freed. + */ +void disk_set_independent_access_ranges(struct gendisk *disk, + struct blk_independent_access_ranges *iars) +{ + struct request_queue *q = disk->queue; + + if (WARN_ON_ONCE(iars && !iars->nr_ia_ranges)) { + kfree(iars); + iars = NULL; + } + + mutex_lock(&q->sysfs_dir_lock); + mutex_lock(&q->sysfs_lock); + + if (iars) { + if (!disk_check_ia_ranges(disk, iars)) { + kfree(iars); + iars = NULL; + goto reg; + } + + if (!disk_ia_ranges_changed(disk, iars)) { + kfree(iars); + goto unlock; + } + } + + /* + * This may be called for a registered queue. E.g. during a device + * revalidation. If that is the case, we need to unregister the old + * set of independent access ranges and register the new set. If the + * queue is not registered, registration of the device request queue + * will register the independent access ranges, so only swap in the + * new set and free the old one. + */ +reg: + if (blk_queue_registered(q)) { + disk_register_independent_access_ranges(disk, iars); + } else { + swap(q->ia_ranges, iars); + kfree(iars); + } + +unlock: + mutex_unlock(&q->sysfs_lock); + mutex_unlock(&q->sysfs_dir_lock); +} +EXPORT_SYMBOL_GPL(disk_set_independent_access_ranges); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 36f14d658e81..cef1f713370b 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -873,16 +873,15 @@ int blk_register_queue(struct gendisk *disk) } mutex_lock(&q->sysfs_lock); + + ret = disk_register_independent_access_ranges(disk, NULL); + if (ret) + goto put_dev; + if (q->elevator) { ret = elv_register_queue(q, false); - if (ret) { - mutex_unlock(&q->sysfs_lock); - mutex_unlock(&q->sysfs_dir_lock); - kobject_del(&q->kobj); - blk_trace_remove_sysfs(dev); - kobject_put(&dev->kobj); - return ret; - } + if (ret) + goto put_dev; } blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q); @@ -913,6 +912,16 @@ int blk_register_queue(struct gendisk *disk) percpu_ref_switch_to_percpu(&q->q_usage_counter); } + return ret; + +put_dev: + disk_unregister_independent_access_ranges(disk); + mutex_unlock(&q->sysfs_lock); + mutex_unlock(&q->sysfs_dir_lock); + kobject_del(&q->kobj); + blk_trace_remove_sysfs(dev); + kobject_put(&dev->kobj); + return ret; } @@ -958,6 +967,7 @@ void blk_unregister_queue(struct gendisk *disk) mutex_lock(&q->sysfs_lock); if (q->elevator) elv_unregister_queue(q); + disk_unregister_independent_access_ranges(disk); mutex_unlock(&q->sysfs_lock); mutex_unlock(&q->sysfs_dir_lock); diff --git a/block/blk.h b/block/blk.h index 6a039e6c7d07..7afffd548daf 100644 --- a/block/blk.h +++ b/block/blk.h @@ -454,4 +454,8 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg); extern const struct address_space_operations def_blk_aops; +int disk_register_independent_access_ranges(struct gendisk *disk, + struct blk_independent_access_ranges *new_iars); +void disk_unregister_independent_access_ranges(struct gendisk *disk); + #endif /* BLK_INTERNAL_H */ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f72ccb2829db..6d95a4b36cfa 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -150,6 +150,34 @@ static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev, #endif /* CONFIG_BLK_DEV_ZONED */ +/* + * Independent access ranges: struct blk_independent_access_range describes + * a range of contiguous sectors that can be accessed using device command + * execution resources that are independent from the resources used for + * other access ranges. This is typically found with single-LUN multi-actuator + * HDDs where each access range is served by a different set of heads. + * The set of independent ranges supported by the device is defined using + * struct blk_independent_access_ranges. The independent ranges must not overlap + * and must include all sectors within the disk capacity (no sector holes + * allowed). + * For a device with multiple ranges, requests targeting sectors in different + * ranges can be executed in parallel. A request can straddle an access range + * boundary. + */ +struct blk_independent_access_range { + struct kobject kobj; + struct request_queue *queue; + sector_t sector; + sector_t nr_sectors; +}; + +struct blk_independent_access_ranges { + struct kobject kobj; + bool sysfs_registered; + unsigned int nr_ia_ranges; + struct blk_independent_access_range ia_range[]; +}; + struct request_queue { struct request *last_merge; struct elevator_queue *elevator; @@ -331,6 +359,12 @@ struct request_queue { #define BLK_MAX_WRITE_HINTS 5 u64 write_hints[BLK_MAX_WRITE_HINTS]; + + /* + * Independent sector access ranges. This is always NULL for + * devices that do not have multiple independent access ranges. + */ + struct blk_independent_access_ranges *ia_ranges; }; /* Keep blk_queue_flag_name[] in sync with the definitions below */ @@ -698,6 +732,11 @@ extern void blk_queue_update_dma_alignment(struct request_queue *, int); extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua); +struct blk_independent_access_ranges * +disk_alloc_independent_access_ranges(struct gendisk *disk, int nr_ia_ranges); +void disk_set_independent_access_ranges(struct gendisk *disk, + struct blk_independent_access_ranges *iars); + /* * Elevator features for blk_queue_required_elevator_features: */