diff options
| -rw-r--r-- | block/Makefile | 2 | ||||
| -rw-r--r-- | block/blk-ia-ranges.c | 348 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 26 | ||||
| -rw-r--r-- | block/blk.h | 4 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 39 |
5 files changed, 410 insertions, 9 deletions
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 <linux/kernel.h> +#include <linux/blkdev.h> +#include <linux/slab.h> +#include <linux/init.h> + +#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); @@ -914,6 +913,16 @@ unlock: } 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: */ |