block: Implement support for zoned block devices

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@suse.de>

[Damien: * Removed the zone cache
         * Implement report zones operation based on earlier proposal
           by Shaun Tancheff <shaun.tancheff@seagate.com>]
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Tested-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Hannes Reinecke 2016-10-18 15:40:33 +09:00 committed by Jens Axboe
parent 2d253440b5
commit 6a0cb1bc10
6 changed files with 401 additions and 0 deletions

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@ -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

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@ -23,3 +23,4 @@ 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_MQ_PCI) += blk-mq-pci.o
obj-$(CONFIG_BLK_DEV_ZONED) += blk-zoned.o

257
block/blk-zoned.c Normal file
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@ -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);

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@ -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;

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@ -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

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@ -0,0 +1,103 @@
/*
* Zoned block devices handling.
*
* Copyright (C) 2015 Seagate Technology PLC
*
* Written by: Shaun Tancheff <shaun.tancheff@seagate.com>
*
* Modified by: Damien Le Moal <damien.lemoal@hgst.com>
* 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 */