leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

null_blk: add zone support

Browse Source 
Adds support for exposing a null_blk device through the zone device
interface.

The interface is managed with the parameters zoned and zone_size.
If zoned is set, the null_blk instance registers as a zoned block
device. The zone_size parameter defines how big each zone will be.

Signed-off-by: Matias Bjørling <matias.bjorling@wdc.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Matias Bjørling 2018-07-06 19:38:39 +02:00 committed by Jens Axboe
parent 6dad38d38f
commit ca4b2a0119
5 changed files with 234 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
Documentation/block/null_blk.txt
View File

@ -85,3 +85,10 @@ shared_tags=[0/1]: Default: 0
0: Tag set is not shared.
1: Tag set shared between devices for blk-mq. Only makes sense with
nr_devices > 1, otherwise there's no tag set to share.
zoned=[0/1]: Default: 0
0: Block device is exposed as a random-access block device.
1: Block device is exposed as a host-managed zoned block device.
zone_size=[MB]: Default: 256
Per zone size when exposed as a zoned block device. Must be a power of two.

5
drivers/block/Makefile
View File

@ -36,8 +36,11 @@ obj-$(CONFIG_BLK_DEV_RBD) += rbd.o
obj-$(CONFIG_BLK_DEV_PCIESSD_MTIP32XX) += mtip32xx/
obj-$(CONFIG_BLK_DEV_RSXX) += rsxx/
obj-$(CONFIG_BLK_DEV_NULL_BLK) += null_blk.o
obj-$(CONFIG_ZRAM) += zram/
obj-$(CONFIG_BLK_DEV_NULL_BLK) += null_blk_mod.o
null_blk_mod-objs := null_blk.o
null_blk_mod-$(CONFIG_BLK_DEV_ZONED) += null_blk_zoned.o
skd-y := skd_main.o
swim_mod-y := swim.o swim_asm.o

48
drivers/block/null_blk.c
View File

@ -180,6 +180,14 @@ static bool g_use_per_node_hctx;
module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, 0444);
MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false");
static bool g_zoned;
module_param_named(zoned, g_zoned, bool, S_IRUGO);
MODULE_PARM_DESC(zoned, "Make device as a host-managed zoned block device. Default: false");
static unsigned long g_zone_size = 256;
module_param_named(zone_size, g_zone_size, ulong, S_IRUGO);
MODULE_PARM_DESC(zone_size, "Zone size in MB when block device is zoned. Must be power-of-two: Default: 256");
static struct nullb_device *null_alloc_dev(void);
static void null_free_dev(struct nullb_device *dev);
static void null_del_dev(struct nullb *nullb);
@ -283,6 +291,8 @@ NULLB_DEVICE_ATTR(memory_backed, bool);
NULLB_DEVICE_ATTR(discard, bool);
NULLB_DEVICE_ATTR(mbps, uint);
NULLB_DEVICE_ATTR(cache_size, ulong);
NULLB_DEVICE_ATTR(zoned, bool);
NULLB_DEVICE_ATTR(zone_size, ulong);
static ssize_t nullb_device_power_show(struct config_item *item, char *page)
{
@ -395,6 +405,8 @@ static struct configfs_attribute *nullb_device_attrs[] = {
&nullb_device_attr_mbps,
&nullb_device_attr_cache_size,
&nullb_device_attr_badblocks,
&nullb_device_attr_zoned,
&nullb_device_attr_zone_size,
NULL,
};
@ -447,7 +459,7 @@ nullb_group_drop_item(struct config_group *group, struct config_item *item)
static ssize_t memb_group_features_show(struct config_item *item, char *page)
{
return snprintf(page, PAGE_SIZE, "memory_backed,discard,bandwidth,cache,badblocks\n");
return snprintf(page, PAGE_SIZE, "memory_backed,discard,bandwidth,cache,badblocks,zoned,zone_size\n");
}
CONFIGFS_ATTR_RO(memb_group_, features);
@ -506,6 +518,8 @@ static struct nullb_device *null_alloc_dev(void)
dev->hw_queue_depth = g_hw_queue_depth;
dev->blocking = g_blocking;
dev->use_per_node_hctx = g_use_per_node_hctx;
dev->zoned = g_zoned;
dev->zone_size = g_zone_size;
return dev;
}
@ -514,6 +528,7 @@ static void null_free_dev(struct nullb_device *dev)
if (!dev)
return;
null_zone_exit(dev);
badblocks_exit(&dev->badblocks);
kfree(dev);
}
@ -1146,6 +1161,11 @@ static blk_status_t null_handle_cmd(struct nullb_cmd *cmd)
struct nullb *nullb = dev->nullb;
int err = 0;
if (req_op(cmd->rq) == REQ_OP_ZONE_REPORT) {
cmd->error = null_zone_report(nullb, cmd);
goto out;
}
if (test_bit(NULLB_DEV_FL_THROTTLED, &dev->flags)) {
struct request *rq = cmd->rq;
@ -1210,6 +1230,13 @@ static blk_status_t null_handle_cmd(struct nullb_cmd *cmd)
}
}
cmd->error = errno_to_blk_status(err);
if (!cmd->error && dev->zoned) {
if (req_op(cmd->rq) == REQ_OP_WRITE)
null_zone_write(cmd);
else if (req_op(cmd->rq) == REQ_OP_ZONE_RESET)
null_zone_reset(cmd);
}
out:
/* Complete IO by inline, softirq or timer */
switch (dev->irqmode) {
@ -1737,6 +1764,15 @@ static int null_add_dev(struct nullb_device *dev)
blk_queue_flush_queueable(nullb->q, true);
}
if (dev->zoned) {
rv = null_zone_init(dev);
if (rv)
goto out_cleanup_blk_queue;
blk_queue_chunk_sectors(nullb->q, dev->zone_size_sects);
nullb->q->limits.zoned = BLK_ZONED_HM;
}
nullb->q->queuedata = nullb;
blk_queue_flag_set(QUEUE_FLAG_NONROT, nullb->q);
blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, nullb->q);
@ -1755,13 +1791,16 @@ static int null_add_dev(struct nullb_device *dev)
rv = null_gendisk_register(nullb);
if (rv)
goto out_cleanup_blk_queue;
goto out_cleanup_zone;
mutex_lock(&lock);
list_add_tail(&nullb->list, &nullb_list);
mutex_unlock(&lock);
return 0;
out_cleanup_zone:
if (dev->zoned)
null_zone_exit(dev);
out_cleanup_blk_queue:
blk_cleanup_queue(nullb->q);
out_cleanup_tags:
@ -1788,6 +1827,11 @@ static int __init null_init(void)
g_bs = PAGE_SIZE;
}
if (!is_power_of_2(g_zone_size)) {
pr_err("null_blk: zone_size must be power-of-two\n");
return -EINVAL;
}
if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) {
if (g_submit_queues != nr_online_nodes) {
pr_warn("null_blk: submit_queues param is set to %u.\n",

28
drivers/block/null_blk.h
View File

@ -41,9 +41,14 @@ struct nullb_device {
unsigned int curr_cache;
struct badblocks badblocks;
unsigned int nr_zones;
struct blk_zone *zones;
sector_t zone_size_sects;
unsigned long size; /* device size in MB */
unsigned long completion_nsec; /* time in ns to complete a request */
unsigned long cache_size; /* disk cache size in MB */
unsigned long zone_size; /* zone size in MB if device is zoned */
unsigned int submit_queues; /* number of submission queues */
unsigned int home_node; /* home node for the device */
unsigned int queue_mode; /* block interface */
@ -57,6 +62,7 @@ struct nullb_device {
bool power; /* power on/off the device */
bool memory_backed; /* if data is stored in memory */
bool discard; /* if support discard */
bool zoned; /* if device is zoned */
};
struct nullb {
@ -77,4 +83,26 @@ struct nullb {
unsigned int nr_queues;
char disk_name[DISK_NAME_LEN];
};
#ifdef CONFIG_BLK_DEV_ZONED
int null_zone_init(struct nullb_device *dev);
void null_zone_exit(struct nullb_device *dev);
blk_status_t null_zone_report(struct nullb *nullb,
struct nullb_cmd *cmd);
void null_zone_write(struct nullb_cmd *cmd);
void null_zone_reset(struct nullb_cmd *cmd);
#else
static inline int null_zone_init(struct nullb_device *dev)
{
return -EINVAL;
}
static inline void null_zone_exit(struct nullb_device *dev) {}
static inline blk_status_t null_zone_report(struct nullb *nullb,
struct nullb_cmd *cmd)
{
return BLK_STS_NOTSUPP;
}
static inline void null_zone_write(struct nullb_cmd *cmd) {}
static inline void null_zone_reset(struct nullb_cmd *cmd) {}
#endif /* CONFIG_BLK_DEV_ZONED */
#endif /* __NULL_BLK_H */

149
drivers/block/null_blk_zoned.c Normal file
View File

@ -0,0 +1,149 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/vmalloc.h>
#include "null_blk.h"
/* zone_size in MBs to sectors. */
#define ZONE_SIZE_SHIFT 11
static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
{
return sect >> ilog2(dev->zone_size_sects);
}
int null_zone_init(struct nullb_device *dev)
{
sector_t dev_size = (sector_t)dev->size * 1024 * 1024;
sector_t sector = 0;
unsigned int i;
if (!is_power_of_2(dev->zone_size)) {
pr_err("null_blk: zone_size must be power-of-two\n");
return -EINVAL;
}
dev->zone_size_sects = dev->zone_size << ZONE_SIZE_SHIFT;
dev->nr_zones = dev_size >>
(SECTOR_SHIFT + ilog2(dev->zone_size_sects));
dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
GFP_KERNEL | __GFP_ZERO);
if (!dev->zones)
return -ENOMEM;
for (i = 0; i < dev->nr_zones; i++) {
struct blk_zone *zone = &dev->zones[i];
zone->start = zone->wp = sector;
zone->len = dev->zone_size_sects;
zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
zone->cond = BLK_ZONE_COND_EMPTY;
sector += dev->zone_size_sects;
}
return 0;
}
void null_zone_exit(struct nullb_device *dev)
{
kvfree(dev->zones);
}
static void null_zone_fill_rq(struct nullb_device *dev, struct request *rq,
unsigned int zno, unsigned int nr_zones)
{
struct blk_zone_report_hdr *hdr = NULL;
struct bio_vec bvec;
struct bvec_iter iter;
void *addr;
unsigned int zones_to_cpy;
bio_for_each_segment(bvec, rq->bio, iter) {
addr = kmap_atomic(bvec.bv_page);
zones_to_cpy = bvec.bv_len / sizeof(struct blk_zone);
if (!hdr) {
hdr = (struct blk_zone_report_hdr *)addr;
hdr->nr_zones = nr_zones;
zones_to_cpy--;
addr += sizeof(struct blk_zone_report_hdr);
}
zones_to_cpy = min_t(unsigned int, zones_to_cpy, nr_zones);
memcpy(addr, &dev->zones[zno],
zones_to_cpy * sizeof(struct blk_zone));
kunmap_atomic(addr);
nr_zones -= zones_to_cpy;
zno += zones_to_cpy;
if (!nr_zones)
break;
}
}
blk_status_t null_zone_report(struct nullb *nullb,
struct nullb_cmd *cmd)
{
struct nullb_device *dev = nullb->dev;
struct request *rq = cmd->rq;
unsigned int zno = null_zone_no(dev, blk_rq_pos(rq));
unsigned int nr_zones = dev->nr_zones - zno;
unsigned int max_zones = (blk_rq_bytes(rq) /
sizeof(struct blk_zone)) - 1;
nr_zones = min_t(unsigned int, nr_zones, max_zones);
null_zone_fill_rq(nullb->dev, rq, zno, nr_zones);
return BLK_STS_OK;
}
void null_zone_write(struct nullb_cmd *cmd)
{
struct nullb_device *dev = cmd->nq->dev;
struct request *rq = cmd->rq;
sector_t sector = blk_rq_pos(rq);
unsigned int rq_sectors = blk_rq_sectors(rq);
unsigned int zno = null_zone_no(dev, sector);
struct blk_zone *zone = &dev->zones[zno];
switch (zone->cond) {
case BLK_ZONE_COND_FULL:
/* Cannot write to a full zone */
cmd->error = BLK_STS_IOERR;
break;
case BLK_ZONE_COND_EMPTY:
case BLK_ZONE_COND_IMP_OPEN:
/* Writes must be at the write pointer position */
if (blk_rq_pos(rq) != zone->wp) {
cmd->error = BLK_STS_IOERR;
break;
}
if (zone->cond == BLK_ZONE_COND_EMPTY)
zone->cond = BLK_ZONE_COND_IMP_OPEN;
zone->wp += rq_sectors;
if (zone->wp == zone->start + zone->len)
zone->cond = BLK_ZONE_COND_FULL;
break;
default:
/* Invalid zone condition */
cmd->error = BLK_STS_IOERR;
break;
}
}
void null_zone_reset(struct nullb_cmd *cmd)
{
struct nullb_device *dev = cmd->nq->dev;
struct request *rq = cmd->rq;
unsigned int zno = null_zone_no(dev, blk_rq_pos(rq));
struct blk_zone *zone = &dev->zones[zno];
zone->cond = BLK_ZONE_COND_EMPTY;
zone->wp = zone->start;
}