From: Matias Bjørling <matias.bjorling@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
---
Documentation/block/null_blk.txt | 7 ++
drivers/block/Makefile | 5 +-
drivers/block/null_blk.c | 48 ++++++++++++-
drivers/block/null_blk.h | 28 ++++++++
drivers/block/null_blk_zoned.c | 149 +++++++++++++++++++++++++++++++++++++++
5 files changed, 234 insertions(+), 3 deletions(-)
create mode 100644 drivers/block/null_blk_zoned.c
diff --git a/Documentation/block/null_blk.txt b/Documentation/block/null_blk.txt
index 07f147381f32..ea2dafe49ae8 100644
--- a/Documentation/block/null_blk.txt
+++ b/Documentation/block/null_blk.txt
@@ -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.
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index dc061158b403..a0d88aa0c05d 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -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
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index cd4b0849d3b4..99b6bfe7abd1 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -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)
{
@@ -394,6 +404,8 @@ 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,
};
@@ -446,7 +458,7 @@ 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);
@@ -505,6 +517,8 @@ 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;
}
@@ -513,6 +527,7 @@ static void null_free_dev(struct nullb_device *dev)
if (!dev)
return;
+ null_zone_exit(dev);
badblocks_exit(&dev->badblocks);
kfree(dev);
}
@@ -1145,6 +1160,11 @@ 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;
@@ -1209,6 +1229,13 @@ 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) {
@@ -1736,6 +1763,15 @@ 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);
@@ -1754,13 +1790,16 @@ 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:
@@ -1787,6 +1826,11 @@ 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",
diff --git a/drivers/block/null_blk.h b/drivers/block/null_blk.h
index d82c5501806d..d81781f22dba 100644
--- a/drivers/block/null_blk.h
+++ b/drivers/block/null_blk.h
@@ -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 */
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
new file mode 100644
index 000000000000..a979ca00d7be
--- /dev/null
+++ b/drivers/block/null_blk_zoned.c
@@ -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;
+}
--
2.11.0
