On Wed, Sep 28, 2016 at 3:45 AM, Damien Le Moal <damien.lemoal@xxxxxxxx> wrote:
> From: Hannes Reinecke <hare@xxxxxxx>
>
> Implement zoned block device zone information reporting and reset.
> Zone information are reported as struct blk_zone. This implementation
> does not differentiate between host-aware and host-managed device
> models and is valid for both. Two functions are provided:
> blkdev_report_zones for discovering the zone configuration of a
> zoned block device, and blkdev_reset_zones for resetting the write
> pointer of sequential zones. The helper function blk_queue_zone_size
> and bdev_zone_size are also provided for, as the name suggest,
> obtaining the zone size (in 512B sectors) of the zones of the device.
>
> Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
>
> [Damien: * Removed the zone cache
> * Implement report zones operation based on earlier proposal
> by Shaun Tancheff <shaun.tancheff@xxxxxxxxxxx>]
> Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxxx>
> ---
> block/Kconfig | 8 ++
> block/Makefile | 1 +
> block/blk-zoned.c | 257 ++++++++++++++++++++++++++++++++++++++++++
> include/linux/blkdev.h | 31 +++++
> include/uapi/linux/Kbuild | 1 +
> include/uapi/linux/blkzoned.h | 103 +++++++++++++++++
> 6 files changed, 401 insertions(+)
> create mode 100644 block/blk-zoned.c
> create mode 100644 include/uapi/linux/blkzoned.h
>
> diff --git a/block/Kconfig b/block/Kconfig
> index 1d4d624..6b0ad08 100644
> --- a/block/Kconfig
> +++ b/block/Kconfig
> @@ -89,6 +89,14 @@ config BLK_DEV_INTEGRITY
> T10/SCSI Data Integrity Field or the T13/ATA External Path
> Protection. If in doubt, say N.
>
> +config BLK_DEV_ZONED
> + bool "Zoned block device support"
> + ---help---
> + Block layer zoned block device support. This option enables
> + support for ZAC/ZBC host-managed and host-aware zoned block devices.
> +
> + Say yes here if you have a ZAC or ZBC storage device.
> +
> config BLK_DEV_THROTTLING
> bool "Block layer bio throttling support"
> depends on BLK_CGROUP=y
> diff --git a/block/Makefile b/block/Makefile
> index 36acdd7..9371bc7 100644
> --- a/block/Makefile
> +++ b/block/Makefile
> @@ -22,4 +22,5 @@ obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
> obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
> obj-$(CONFIG_BLK_CMDLINE_PARSER) += cmdline-parser.o
> obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o
> +obj-$(CONFIG_BLK_DEV_ZONED) += blk-zoned.o
> obj-$(CONFIG_BLK_MQ_PCI) += blk-mq-pci.o
> diff --git a/block/blk-zoned.c b/block/blk-zoned.c
> new file mode 100644
> index 0000000..1603573
> --- /dev/null
> +++ b/block/blk-zoned.c
> @@ -0,0 +1,257 @@
> +/*
> + * Zoned block device handling
> + *
> + * Copyright (c) 2015, Hannes Reinecke
> + * Copyright (c) 2015, SUSE Linux GmbH
> + *
> + * Copyright (c) 2016, Damien Le Moal
> + * Copyright (c) 2016, Western Digital
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/rbtree.h>
> +#include <linux/blkdev.h>
> +
> +static inline sector_t blk_zone_start(struct request_queue *q,
> + sector_t sector)
> +{
> + sector_t zone_mask = blk_queue_zone_size(q) - 1;
> +
> + return sector & ~zone_mask;
> +}
> +
> +/*
> + * Check that a zone report belongs to the partition.
> + * If yes, fix its start sector and write pointer, copy it in the
> + * zone information array and return true. Return false otherwise.
> + */
> +static bool blkdev_report_zone(struct block_device *bdev,
> + struct blk_zone *rep,
> + struct blk_zone *zone)
> +{
> + sector_t offset = get_start_sect(bdev);
> +
> + if (rep->start < offset)
> + return false;
> +
> + rep->start -= offset;
> + if (rep->start + rep->len > bdev->bd_part->nr_sects)
> + return false;
> +
> + if (rep->type == BLK_ZONE_TYPE_CONVENTIONAL)
> + rep->wp = rep->start + rep->len;
> + else
> + rep->wp -= offset;
> + memcpy(zone, rep, sizeof(struct blk_zone));
> +
> + return true;
> +}
> +
> +/**
> + * blkdev_report_zones - Get zones information
> + * @bdev: Target block device
> + * @sector: Sector from which to report zones
> + * @zones: Array of zone structures where to return the zones information
> + * @nr_zones: Number of zone structures in the zone array
> + * @gfp_mask: Memory allocation flags (for bio_alloc)
> + *
> + * Description:
> + * Get zone information starting from the zone containing @sector.
> + * The number of zone information reported may be less than the number
> + * requested by @nr_zones. The number of zones actually reported is
> + * returned in @nr_zones.
> + */
> +int blkdev_report_zones(struct block_device *bdev,
> + sector_t sector,
> + struct blk_zone *zones,
> + unsigned int *nr_zones,
> + gfp_t gfp_mask)
> +{
> + struct request_queue *q = bdev_get_queue(bdev);
> + struct blk_zone_report_hdr *hdr;
> + unsigned int nrz = *nr_zones;
> + struct page *page;
> + unsigned int nr_rep;
> + size_t rep_bytes;
> + unsigned int nr_pages;
> + struct bio *bio;
> + struct bio_vec *bv;
> + unsigned int i, n, nz;
> + unsigned int ofst;
> + void *addr;
> + int ret = 0;
> +
> + if (!q)
> + return -ENXIO;
> +
> + if (!blk_queue_is_zoned(q))
> + return -EOPNOTSUPP;
> +
> + if (!nrz)
> + return 0;
> +
> + if (sector > bdev->bd_part->nr_sects) {
> + *nr_zones = 0;
> + return 0;
> + }
> +
> + /*
> + * The zone report has a header. So make room for it in the
> + * payload. Also make sure that the report fits in a single BIO
> + * that will not be split down the stack.
> + */
> + rep_bytes = sizeof(struct blk_zone_report_hdr) +
> + sizeof(struct blk_zone) * nrz;
> + rep_bytes = (rep_bytes + PAGE_SIZE - 1) & PAGE_MASK;
> + if (rep_bytes > (queue_max_sectors(q) << 9))
> + rep_bytes = queue_max_sectors(q) << 9;
> +
> + nr_pages = min_t(unsigned int, BIO_MAX_PAGES,
> + rep_bytes >> PAGE_SHIFT);
> + nr_pages = min_t(unsigned int, nr_pages,
> + queue_max_segments(q));
> +
> + bio = bio_alloc(gfp_mask, nr_pages);
> + if (!bio)
> + return -ENOMEM;
> +
> + bio->bi_bdev = bdev;
> + bio->bi_iter.bi_sector = blk_zone_start(q, sector);
> + bio_set_op_attrs(bio, REQ_OP_ZONE_REPORT, 0);
> +
> + for (i = 0; i < nr_pages; i++) {
> + page = alloc_page(gfp_mask);
> + if (!page) {
> + ret = -ENOMEM;
> + goto out;
> + }
> + if (!bio_add_page(bio, page, PAGE_SIZE, 0)) {
> + __free_page(page);
> + break;
> + }
> + }
> +
> + if (i == 0)
> + ret = -ENOMEM;
> + else
> + ret = submit_bio_wait(bio);
> + if (ret)
> + goto out;
> +
> + /*
> + * Process the report result: skip the header and go through the
> + * reported zones to fixup and fixup the zone information for
> + * partitions. At the same time, return the zone information into
> + * the zone array.
> + */
> + n = 0;
> + nz = 0;
> + nr_rep = 0;
> + bio_for_each_segment_all(bv, bio, i) {
> +
> + if (!bv->bv_page)
> + break;
> +
> + addr = kmap_atomic(bv->bv_page);
> +
> + /* Get header in the first page */
> + ofst = 0;
> + if (!nr_rep) {
> + hdr = (struct blk_zone_report_hdr *) addr;
> + nr_rep = hdr->nr_zones;
> + ofst = sizeof(struct blk_zone_report_hdr);
> + }
> +
> + /* Fixup and report zones */
> + while (ofst < bv->bv_len &&
> + n < nr_rep && nz < nrz) {
> + if (blkdev_report_zone(bdev, addr + ofst, &zones[nz]))
> + nz++;
> + ofst += sizeof(struct blk_zone);
> + n++;
> + }
> +
> + kunmap_atomic(addr);
> +
> + if (n >= nr_rep || nz >= nrz)
> + break;
> +
> + }
> +
> +out:
> + bio_for_each_segment_all(bv, bio, i)
> + __free_page(bv->bv_page);
> + bio_put(bio);
> +
> + if (ret == 0)
> + *nr_zones = nz;
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(blkdev_report_zones);
> +
> +/**
> + * blkdev_reset_zones - Reset zones write pointer
> + * @bdev: Target block device
> + * @sector: Start sector of the first zone to reset
> + * @nr_sectors: Number of sectors, at least the length of one zone
> + * @gfp_mask: Memory allocation flags (for bio_alloc)
> + *
> + * Description:
> + * Reset the write pointer of the zones contained in the range
> + * @sector..@sector+@nr_sectors. Specifying the entire disk sector range
> + * is valid, but the specified range should not contain conventional zones.
> + */
> +int blkdev_reset_zones(struct block_device *bdev,
> + sector_t sector, sector_t nr_sectors,
> + gfp_t gfp_mask)
> +{
> + struct request_queue *q = bdev_get_queue(bdev);
> + sector_t zone_sectors;
> + sector_t end_sector = sector + nr_sectors;
> + struct bio *bio;
> + int ret;
> +
> + if (!q)
> + return -ENXIO;
> +
> + if (!blk_queue_is_zoned(q))
> + return -EOPNOTSUPP;
> +
> + if (end_sector > bdev->bd_part->nr_sects)
> + /* Out of range */
> + return -EINVAL;
> +
> + /* Check alignment (handle eventual smaller last zone) */
> + zone_sectors = blk_queue_zone_size(q);
> + if (sector & (zone_sectors - 1))
> + return -EINVAL;
> +
> + if ((nr_sectors & (zone_sectors - 1)) &&
> + end_sector != bdev->bd_part->nr_sects)
> + return -EINVAL;
> +
> + while (sector < end_sector) {
> +
> + bio = bio_alloc(gfp_mask, 0);
> + bio->bi_iter.bi_sector = sector;
> + bio->bi_bdev = bdev;
> + bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
> +
> + ret = submit_bio_wait(bio);
> + bio_put(bio);
> +
> + if (ret)
> + return ret;
> +
> + sector += zone_sectors;
> +
> + /* This may take a while, so be nice to others */
> + cond_resched();
> +
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(blkdev_reset_zones);
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index f19e16b..252043f 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -24,6 +24,7 @@
> #include <linux/rcupdate.h>
> #include <linux/percpu-refcount.h>
> #include <linux/scatterlist.h>
> +#include <linux/blkzoned.h>
>
> struct module;
> struct scsi_ioctl_command;
> @@ -302,6 +303,21 @@ struct queue_limits {
> enum blk_zoned_model zoned;
> };
>
> +#ifdef CONFIG_BLK_DEV_ZONED
> +
> +struct blk_zone_report_hdr {
> + unsigned int nr_zones;
> + u8 padding[60];
> +};
> +
> +extern int blkdev_report_zones(struct block_device *bdev,
> + sector_t sector, struct blk_zone *zones,
> + unsigned int *nr_zones, gfp_t gfp_mask);
> +extern int blkdev_reset_zones(struct block_device *bdev, sector_t sectors,
> + sector_t nr_sectors, gfp_t gfp_mask);
> +
> +#endif /* CONFIG_BLK_DEV_ZONED */
> +
> struct request_queue {
> /*
> * Together with queue_head for cacheline sharing
> @@ -654,6 +670,11 @@ static inline bool blk_queue_is_zoned(struct request_queue *q)
> }
> }
>
> +static inline unsigned int blk_queue_zone_size(struct request_queue *q)
> +{
> + return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
> +}
> +
> /*
> * We regard a request as sync, if either a read or a sync write
> */
> @@ -1401,6 +1422,16 @@ static inline bool bdev_is_zoned(struct block_device *bdev)
> return false;
> }
>
> +static inline unsigned int bdev_zone_size(struct block_device *bdev)
> +{
> + struct request_queue *q = bdev_get_queue(bdev);
> +
> + if (q)
> + return blk_queue_zone_size(q);
> +
> + return 0;
> +}
> +
> static inline int queue_dma_alignment(struct request_queue *q)
> {
> return q ? q->dma_alignment : 511;
> diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
> index dd60439..92466a6 100644
> --- a/include/uapi/linux/Kbuild
> +++ b/include/uapi/linux/Kbuild
> @@ -70,6 +70,7 @@ header-y += bfs_fs.h
> header-y += binfmts.h
> header-y += blkpg.h
> header-y += blktrace_api.h
> +header-y += blkzoned.h
> header-y += bpf_common.h
> header-y += bpf_perf_event.h
> header-y += bpf.h
> diff --git a/include/uapi/linux/blkzoned.h b/include/uapi/linux/blkzoned.h
> new file mode 100644
> index 0000000..a381721
> --- /dev/null
> +++ b/include/uapi/linux/blkzoned.h
> @@ -0,0 +1,103 @@
> +/*
> + * Zoned block devices handling.
> + *
> + * Copyright (C) 2015 Seagate Technology PLC
> + *
> + * Written by: Shaun Tancheff <shaun.tancheff@xxxxxxxxxxx>
> + *
> + * Modified by: Damien Le Moal <damien.lemoal@xxxxxxxx>
> + * Copyright (C) 2016 Western Digital
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +#ifndef _UAPI_BLKZONED_H
> +#define _UAPI_BLKZONED_H
> +
> +#include <linux/types.h>
> +
> +/**
> + * enum blk_zone_type - Types of zones allowed in a zoned device.
> + *
> + * @BLK_ZONE_TYPE_CONVENTIONAL: The zone has no write pointer and can be writen
> + * randomly. Zone reset has no effect on the zone.
> + * @BLK_ZONE_TYPE_SEQWRITE_REQ: The zone must be written sequentially
> + * @BLK_ZONE_TYPE_SEQWRITE_PREF: The zone can be written non-sequentially
> + *
> + * Any other value not defined is reserved and must be considered as invalid.
> + */
> +enum blk_zone_type {
> + BLK_ZONE_TYPE_CONVENTIONAL = 0x1,
> + BLK_ZONE_TYPE_SEQWRITE_REQ = 0x2,
> + BLK_ZONE_TYPE_SEQWRITE_PREF = 0x3,
> +};
> +
> +/**
> + * enum blk_zone_cond - Condition [state] of a zone in a zoned device.
> + *
> + * @BLK_ZONE_COND_NOT_WP: The zone has no write pointer, it is conventional.
> + * @BLK_ZONE_COND_EMPTY: The zone is empty.
> + * @BLK_ZONE_COND_IMP_OPEN: The zone is open, but not explicitly opened.
> + * @BLK_ZONE_COND_EXP_OPEN: The zones was explicitly opened by an
> + * OPEN ZONE command.
> + * @BLK_ZONE_COND_CLOSED: The zone was [explicitly] closed after writing.
> + * @BLK_ZONE_COND_FULL: The zone is marked as full, possibly by a zone
> + * FINISH ZONE command.
> + * @BLK_ZONE_COND_READONLY: The zone is read-only.
> + * @BLK_ZONE_COND_OFFLINE: The zone is offline (sectors cannot be read/written).
> + *
> + * The Zone Condition state machine in the ZBC/ZAC standards maps the above
> + * deinitions as:
> + * - ZC1: Empty | BLK_ZONE_EMPTY
> + * - ZC2: Implicit Open | BLK_ZONE_COND_IMP_OPEN
> + * - ZC3: Explicit Open | BLK_ZONE_COND_EXP_OPEN
> + * - ZC4: Closed | BLK_ZONE_CLOSED
> + * - ZC5: Full | BLK_ZONE_FULL
> + * - ZC6: Read Only | BLK_ZONE_READONLY
> + * - ZC7: Offline | BLK_ZONE_OFFLINE
> + *
> + * Conditions 0x5 to 0xC are reserved by the current ZBC/ZAC spec and should
> + * be considered invalid.
> + */
> +enum blk_zone_cond {
> + BLK_ZONE_COND_NOT_WP = 0x0,
> + BLK_ZONE_COND_EMPTY = 0x1,
> + BLK_ZONE_COND_IMP_OPEN = 0x2,
> + BLK_ZONE_COND_EXP_OPEN = 0x3,
> + BLK_ZONE_COND_CLOSED = 0x4,
> + BLK_ZONE_COND_READONLY = 0xD,
> + BLK_ZONE_COND_FULL = 0xE,
> + BLK_ZONE_COND_OFFLINE = 0xF,
> +};
> +
> +/**
> + * struct blk_zone - Zone descriptor for BLKREPORTZONE ioctl.
> + *
> + * @start: Zone start in 512 B sector units
> + * @len: Zone length in 512 B sector units
> + * @wp: Zone write pointer location in 512 B sector units
> + * @type: see enum blk_zone_type for possible values
> + * @cond: see enum blk_zone_cond for possible values
> + * @non_seq: Flag indicating that the zone is using non-sequential resources
> + * (for host-aware zoned block devices only).
> + * @reset: Flag indicating that a zone reset is recommended.
> + * @reserved: Padding to 64 B to match the ZBC/ZAC defined zone descriptor size.
> + *
> + * start, len and wp use the regular 512 B sector unit, regardless of the
> + * device logical block size. The overall structure size is 64 B to match the
> + * ZBC/ZAC defined zone descriptor and allow support for future additional
> + * zone information.
> + */
> +struct blk_zone {
> + __u64 start; /* Zone start sector */
> + __u64 len; /* Zone length in number of sectors */
> + __u64 wp; /* Zone write pointer position */
> + __u8 type; /* Zone type */
> + __u8 cond; /* Zone condition */
> + __u8 non_seq; /* Non-sequential write resources active */
> + __u8 reset; /* Reset write pointer recommended */
> + __u8 reserved[36];
> +};
> +
> +#endif /* _UAPI_BLKZONED_H */
> --
> 2.7.4
Reviewed-by: Shaun Tancheff <shaun.tancheff@xxxxxxxxxxx>
Tested-by: Shaun Tancheff <shaun.tancheff@xxxxxxxxxxx>
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--
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