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|
// SPDX-License-Identifier: GPL-2.0
#include <linux/vmalloc.h>
#include <linux/bitmap.h>
#include "null_blk.h"
#define CREATE_TRACE_POINTS
#include "trace.h"
#undef pr_fmt
#define pr_fmt(fmt) "null_blk: " fmt
static inline sector_t mb_to_sects(unsigned long mb)
{
return ((sector_t)mb * SZ_1M) >> SECTOR_SHIFT;
}
static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
{
return sect >> ilog2(dev->zone_size_sects);
}
static inline void null_lock_zone_res(struct nullb_device *dev)
{
if (dev->need_zone_res_mgmt)
spin_lock_irq(&dev->zone_res_lock);
}
static inline void null_unlock_zone_res(struct nullb_device *dev)
{
if (dev->need_zone_res_mgmt)
spin_unlock_irq(&dev->zone_res_lock);
}
static inline void null_init_zone_lock(struct nullb_device *dev,
struct nullb_zone *zone)
{
if (!dev->memory_backed)
spin_lock_init(&zone->spinlock);
else
mutex_init(&zone->mutex);
}
static inline void null_lock_zone(struct nullb_device *dev,
struct nullb_zone *zone)
{
if (!dev->memory_backed)
spin_lock_irq(&zone->spinlock);
else
mutex_lock(&zone->mutex);
}
static inline void null_unlock_zone(struct nullb_device *dev,
struct nullb_zone *zone)
{
if (!dev->memory_backed)
spin_unlock_irq(&zone->spinlock);
else
mutex_unlock(&zone->mutex);
}
int null_init_zoned_dev(struct nullb_device *dev,
struct queue_limits *lim)
{
sector_t dev_capacity_sects, zone_capacity_sects;
struct nullb_zone *zone;
sector_t sector = 0;
unsigned int i;
if (!is_power_of_2(dev->zone_size)) {
pr_err("zone_size must be power-of-two\n");
return -EINVAL;
}
if (dev->zone_size > dev->size) {
pr_err("Zone size larger than device capacity\n");
return -EINVAL;
}
if (!dev->zone_capacity)
dev->zone_capacity = dev->zone_size;
if (dev->zone_capacity > dev->zone_size) {
pr_err("zone capacity (%lu MB) larger than zone size (%lu MB)\n",
dev->zone_capacity, dev->zone_size);
return -EINVAL;
}
/*
* If a smaller zone capacity was requested, do not allow a smaller last
* zone at the same time as such zone configuration does not correspond
* to any real zoned device.
*/
if (dev->zone_capacity != dev->zone_size &&
dev->size & (dev->zone_size - 1)) {
pr_err("A smaller last zone is not allowed with zone capacity smaller than zone size.\n");
return -EINVAL;
}
zone_capacity_sects = mb_to_sects(dev->zone_capacity);
dev_capacity_sects = mb_to_sects(dev->size);
dev->zone_size_sects = mb_to_sects(dev->zone_size);
dev->nr_zones = round_up(dev_capacity_sects, dev->zone_size_sects)
>> ilog2(dev->zone_size_sects);
dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct nullb_zone),
GFP_KERNEL | __GFP_ZERO);
if (!dev->zones)
return -ENOMEM;
spin_lock_init(&dev->zone_res_lock);
if (dev->zone_nr_conv >= dev->nr_zones) {
dev->zone_nr_conv = dev->nr_zones - 1;
pr_info("changed the number of conventional zones to %u",
dev->zone_nr_conv);
}
/* Max active zones has to be < nbr of seq zones in order to be enforceable */
if (dev->zone_max_active >= dev->nr_zones - dev->zone_nr_conv) {
dev->zone_max_active = 0;
pr_info("zone_max_active limit disabled, limit >= zone count\n");
}
/* Max open zones has to be <= max active zones */
if (dev->zone_max_active && dev->zone_max_open > dev->zone_max_active) {
dev->zone_max_open = dev->zone_max_active;
pr_info("changed the maximum number of open zones to %u\n",
dev->zone_max_open);
} else if (dev->zone_max_open >= dev->nr_zones - dev->zone_nr_conv) {
dev->zone_max_open = 0;
pr_info("zone_max_open limit disabled, limit >= zone count\n");
}
dev->need_zone_res_mgmt = dev->zone_max_active || dev->zone_max_open;
dev->imp_close_zone_no = dev->zone_nr_conv;
for (i = 0; i < dev->zone_nr_conv; i++) {
zone = &dev->zones[i];
null_init_zone_lock(dev, zone);
zone->start = sector;
zone->len = dev->zone_size_sects;
zone->capacity = zone->len;
zone->wp = zone->start + zone->len;
zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
zone->cond = BLK_ZONE_COND_NOT_WP;
sector += dev->zone_size_sects;
}
for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
zone = &dev->zones[i];
null_init_zone_lock(dev, zone);
zone->start = zone->wp = sector;
if (zone->start + dev->zone_size_sects > dev_capacity_sects)
zone->len = dev_capacity_sects - zone->start;
else
zone->len = dev->zone_size_sects;
zone->capacity =
min_t(sector_t, zone->len, zone_capacity_sects);
zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
zone->cond = BLK_ZONE_COND_EMPTY;
sector += dev->zone_size_sects;
}
lim->zoned = true;
lim->chunk_sectors = dev->zone_size_sects;
lim->max_zone_append_sectors = dev->zone_size_sects;
lim->max_open_zones = dev->zone_max_open;
lim->max_active_zones = dev->zone_max_active;
return 0;
}
int null_register_zoned_dev(struct nullb *nullb)
{
struct request_queue *q = nullb->q;
blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
blk_queue_required_elevator_features(q, ELEVATOR_F_ZBD_SEQ_WRITE);
nullb->disk->nr_zones = bdev_nr_zones(nullb->disk->part0);
return blk_revalidate_disk_zones(nullb->disk, NULL);
}
void null_free_zoned_dev(struct nullb_device *dev)
{
kvfree(dev->zones);
dev->zones = NULL;
}
int null_report_zones(struct gendisk *disk, sector_t sector,
unsigned int nr_zones, report_zones_cb cb, void *data)
{
struct nullb *nullb = disk->private_data;
struct nullb_device *dev = nullb->dev;
unsigned int first_zone, i;
struct nullb_zone *zone;
struct blk_zone blkz;
int error;
first_zone = null_zone_no(dev, sector);
if (first_zone >= dev->nr_zones)
return 0;
nr_zones = min(nr_zones, dev->nr_zones - first_zone);
trace_nullb_report_zones(nullb, nr_zones);
memset(&blkz, 0, sizeof(struct blk_zone));
zone = &dev->zones[first_zone];
for (i = 0; i < nr_zones; i++, zone++) {
/*
* Stacked DM target drivers will remap the zone information by
* modifying the zone information passed to the report callback.
* So use a local copy to avoid corruption of the device zone
* array.
*/
null_lock_zone(dev, zone);
blkz.start = zone->start;
blkz.len = zone->len;
blkz.wp = zone->wp;
blkz.type = zone->type;
blkz.cond = zone->cond;
blkz.capacity = zone->capacity;
null_unlock_zone(dev, zone);
error = cb(&blkz, i, data);
if (error)
return error;
}
return nr_zones;
}
/*
* This is called in the case of memory backing from null_process_cmd()
* with the target zone already locked.
*/
size_t null_zone_valid_read_len(struct nullb *nullb,
sector_t sector, unsigned int len)
{
struct nullb_device *dev = nullb->dev;
struct nullb_zone *zone = &dev->zones[null_zone_no(dev, sector)];
unsigned int nr_sectors = len >> SECTOR_SHIFT;
/* Read must be below the write pointer position */
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL ||
sector + nr_sectors <= zone->wp)
return len;
if (sector > zone->wp)
return 0;
return (zone->wp - sector) << SECTOR_SHIFT;
}
static blk_status_t __null_close_zone(struct nullb_device *dev,
struct nullb_zone *zone)
{
switch (zone->cond) {
case BLK_ZONE_COND_CLOSED:
/* close operation on closed is not an error */
return BLK_STS_OK;
case BLK_ZONE_COND_IMP_OPEN:
dev->nr_zones_imp_open--;
break;
case BLK_ZONE_COND_EXP_OPEN:
dev->nr_zones_exp_open--;
break;
case BLK_ZONE_COND_EMPTY:
case BLK_ZONE_COND_FULL:
default:
return BLK_STS_IOERR;
}
if (zone->wp == zone->start) {
zone->cond = BLK_ZONE_COND_EMPTY;
} else {
zone->cond = BLK_ZONE_COND_CLOSED;
dev->nr_zones_closed++;
}
return BLK_STS_OK;
}
static void null_close_imp_open_zone(struct nullb_device *dev)
{
struct nullb_zone *zone;
unsigned int zno, i;
zno = dev->imp_close_zone_no;
if (zno >= dev->nr_zones)
zno = dev->zone_nr_conv;
for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
zone = &dev->zones[zno];
zno++;
if (zno >= dev->nr_zones)
zno = dev->zone_nr_conv;
if (zone->cond == BLK_ZONE_COND_IMP_OPEN) {
__null_close_zone(dev, zone);
dev->imp_close_zone_no = zno;
return;
}
}
}
static blk_status_t null_check_active(struct nullb_device *dev)
{
if (!dev->zone_max_active)
return BLK_STS_OK;
if (dev->nr_zones_exp_open + dev->nr_zones_imp_open +
dev->nr_zones_closed < dev->zone_max_active)
return BLK_STS_OK;
return BLK_STS_ZONE_ACTIVE_RESOURCE;
}
static blk_status_t null_check_open(struct nullb_device *dev)
{
if (!dev->zone_max_open)
return BLK_STS_OK;
if (dev->nr_zones_exp_open + dev->nr_zones_imp_open < dev->zone_max_open)
return BLK_STS_OK;
if (dev->nr_zones_imp_open) {
if (null_check_active(dev) == BLK_STS_OK) {
null_close_imp_open_zone(dev);
return BLK_STS_OK;
}
}
return BLK_STS_ZONE_OPEN_RESOURCE;
}
/*
* This function matches the manage open zone resources function in the ZBC standard,
* with the addition of max active zones support (added in the ZNS standard).
*
* The function determines if a zone can transition to implicit open or explicit open,
* while maintaining the max open zone (and max active zone) limit(s). It may close an
* implicit open zone in order to make additional zone resources available.
*
* ZBC states that an implicit open zone shall be closed only if there is not
* room within the open limit. However, with the addition of an active limit,
* it is not certain that closing an implicit open zone will allow a new zone
* to be opened, since we might already be at the active limit capacity.
*/
static blk_status_t null_check_zone_resources(struct nullb_device *dev,
struct nullb_zone *zone)
{
blk_status_t ret;
switch (zone->cond) {
case BLK_ZONE_COND_EMPTY:
ret = null_check_active(dev);
if (ret != BLK_STS_OK)
return ret;
fallthrough;
case BLK_ZONE_COND_CLOSED:
return null_check_open(dev);
default:
/* Should never be called for other states */
WARN_ON(1);
return BLK_STS_IOERR;
}
}
static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
unsigned int nr_sectors, bool append)
{
struct nullb_device *dev = cmd->nq->dev;
unsigned int zno = null_zone_no(dev, sector);
struct nullb_zone *zone = &dev->zones[zno];
blk_status_t ret;
trace_nullb_zone_op(cmd, zno, zone->cond);
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
if (append)
return BLK_STS_IOERR;
return null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
}
null_lock_zone(dev, zone);
if (zone->cond == BLK_ZONE_COND_FULL ||
zone->cond == BLK_ZONE_COND_READONLY ||
zone->cond == BLK_ZONE_COND_OFFLINE) {
/* Cannot write to the zone */
ret = BLK_STS_IOERR;
goto unlock;
}
/*
* Regular writes must be at the write pointer position.
* Zone append writes are automatically issued at the write
* pointer and the position returned using the request or BIO
* sector.
*/
if (append) {
sector = zone->wp;
blk_mq_rq_from_pdu(cmd)->__sector = sector;
} else if (sector != zone->wp) {
ret = BLK_STS_IOERR;
goto unlock;
}
if (zone->wp + nr_sectors > zone->start + zone->capacity) {
ret = BLK_STS_IOERR;
goto unlock;
}
if (zone->cond == BLK_ZONE_COND_CLOSED ||
zone->cond == BLK_ZONE_COND_EMPTY) {
null_lock_zone_res(dev);
ret = null_check_zone_resources(dev, zone);
if (ret != BLK_STS_OK) {
null_unlock_zone_res(dev);
goto unlock;
}
if (zone->cond == BLK_ZONE_COND_CLOSED) {
dev->nr_zones_closed--;
dev->nr_zones_imp_open++;
} else if (zone->cond == BLK_ZONE_COND_EMPTY) {
dev->nr_zones_imp_open++;
}
if (zone->cond != BLK_ZONE_COND_EXP_OPEN)
zone->cond = BLK_ZONE_COND_IMP_OPEN;
null_unlock_zone_res(dev);
}
ret = null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
if (ret != BLK_STS_OK)
goto unlock;
zone->wp += nr_sectors;
if (zone->wp == zone->start + zone->capacity) {
null_lock_zone_res(dev);
if (zone->cond == BLK_ZONE_COND_EXP_OPEN)
dev->nr_zones_exp_open--;
else if (zone->cond == BLK_ZONE_COND_IMP_OPEN)
dev->nr_zones_imp_open--;
zone->cond = BLK_ZONE_COND_FULL;
null_unlock_zone_res(dev);
}
ret = BLK_STS_OK;
unlock:
null_unlock_zone(dev, zone);
return ret;
}
static blk_status_t null_open_zone(struct nullb_device *dev,
struct nullb_zone *zone)
{
blk_status_t ret = BLK_STS_OK;
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
return BLK_STS_IOERR;
null_lock_zone_res(dev);
switch (zone->cond) {
case BLK_ZONE_COND_EXP_OPEN:
/* open operation on exp open is not an error */
goto unlock;
case BLK_ZONE_COND_EMPTY:
ret = null_check_zone_resources(dev, zone);
if (ret != BLK_STS_OK)
goto unlock;
break;
case BLK_ZONE_COND_IMP_OPEN:
dev->nr_zones_imp_open--;
break;
case BLK_ZONE_COND_CLOSED:
ret = null_check_zone_resources(dev, zone);
if (ret != BLK_STS_OK)
goto unlock;
dev->nr_zones_closed--;
break;
case BLK_ZONE_COND_FULL:
default:
ret = BLK_STS_IOERR;
goto unlock;
}
zone->cond = BLK_ZONE_COND_EXP_OPEN;
dev->nr_zones_exp_open++;
unlock:
null_unlock_zone_res(dev);
return ret;
}
static blk_status_t null_close_zone(struct nullb_device *dev,
struct nullb_zone *zone)
{
blk_status_t ret;
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
return BLK_STS_IOERR;
null_lock_zone_res(dev);
ret = __null_close_zone(dev, zone);
null_unlock_zone_res(dev);
return ret;
}
static blk_status_t null_finish_zone(struct nullb_device *dev,
struct nullb_zone *zone)
{
blk_status_t ret = BLK_STS_OK;
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
return BLK_STS_IOERR;
null_lock_zone_res(dev);
switch (zone->cond) {
case BLK_ZONE_COND_FULL:
/* finish operation on full is not an error */
goto unlock;
case BLK_ZONE_COND_EMPTY:
ret = null_check_zone_resources(dev, zone);
if (ret != BLK_STS_OK)
goto unlock;
break;
case BLK_ZONE_COND_IMP_OPEN:
dev->nr_zones_imp_open--;
break;
case BLK_ZONE_COND_EXP_OPEN:
dev->nr_zones_exp_open--;
break;
case BLK_ZONE_COND_CLOSED:
ret = null_check_zone_resources(dev, zone);
if (ret != BLK_STS_OK)
goto unlock;
dev->nr_zones_closed--;
break;
default:
ret = BLK_STS_IOERR;
goto unlock;
}
zone->cond = BLK_ZONE_COND_FULL;
zone->wp = zone->start + zone->len;
unlock:
null_unlock_zone_res(dev);
return ret;
}
static blk_status_t null_reset_zone(struct nullb_device *dev,
struct nullb_zone *zone)
{
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
return BLK_STS_IOERR;
null_lock_zone_res(dev);
switch (zone->cond) {
case BLK_ZONE_COND_EMPTY:
/* reset operation on empty is not an error */
null_unlock_zone_res(dev);
return BLK_STS_OK;
case BLK_ZONE_COND_IMP_OPEN:
dev->nr_zones_imp_open--;
break;
case BLK_ZONE_COND_EXP_OPEN:
dev->nr_zones_exp_open--;
break;
case BLK_ZONE_COND_CLOSED:
dev->nr_zones_closed--;
break;
case BLK_ZONE_COND_FULL:
break;
default:
null_unlock_zone_res(dev);
return BLK_STS_IOERR;
}
zone->cond = BLK_ZONE_COND_EMPTY;
zone->wp = zone->start;
null_unlock_zone_res(dev);
if (dev->memory_backed)
return null_handle_discard(dev, zone->start, zone->len);
return BLK_STS_OK;
}
static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_op op,
sector_t sector)
{
struct nullb_device *dev = cmd->nq->dev;
unsigned int zone_no;
struct nullb_zone *zone;
blk_status_t ret;
size_t i;
if (op == REQ_OP_ZONE_RESET_ALL) {
for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
zone = &dev->zones[i];
null_lock_zone(dev, zone);
if (zone->cond != BLK_ZONE_COND_EMPTY &&
zone->cond != BLK_ZONE_COND_READONLY &&
zone->cond != BLK_ZONE_COND_OFFLINE) {
null_reset_zone(dev, zone);
trace_nullb_zone_op(cmd, i, zone->cond);
}
null_unlock_zone(dev, zone);
}
return BLK_STS_OK;
}
zone_no = null_zone_no(dev, sector);
zone = &dev->zones[zone_no];
null_lock_zone(dev, zone);
if (zone->cond == BLK_ZONE_COND_READONLY ||
zone->cond == BLK_ZONE_COND_OFFLINE) {
ret = BLK_STS_IOERR;
goto unlock;
}
switch (op) {
case REQ_OP_ZONE_RESET:
ret = null_reset_zone(dev, zone);
break;
case REQ_OP_ZONE_OPEN:
ret = null_open_zone(dev, zone);
break;
case REQ_OP_ZONE_CLOSE:
ret = null_close_zone(dev, zone);
break;
case REQ_OP_ZONE_FINISH:
ret = null_finish_zone(dev, zone);
break;
default:
ret = BLK_STS_NOTSUPP;
break;
}
if (ret == BLK_STS_OK)
trace_nullb_zone_op(cmd, zone_no, zone->cond);
unlock:
null_unlock_zone(dev, zone);
return ret;
}
blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_op op,
sector_t sector, sector_t nr_sectors)
{
struct nullb_device *dev;
struct nullb_zone *zone;
blk_status_t sts;
switch (op) {
case REQ_OP_WRITE:
return null_zone_write(cmd, sector, nr_sectors, false);
case REQ_OP_ZONE_APPEND:
return null_zone_write(cmd, sector, nr_sectors, true);
case REQ_OP_ZONE_RESET:
case REQ_OP_ZONE_RESET_ALL:
case REQ_OP_ZONE_OPEN:
case REQ_OP_ZONE_CLOSE:
case REQ_OP_ZONE_FINISH:
return null_zone_mgmt(cmd, op, sector);
default:
dev = cmd->nq->dev;
zone = &dev->zones[null_zone_no(dev, sector)];
if (zone->cond == BLK_ZONE_COND_OFFLINE)
return BLK_STS_IOERR;
null_lock_zone(dev, zone);
sts = null_process_cmd(cmd, op, sector, nr_sectors);
null_unlock_zone(dev, zone);
return sts;
}
}
/*
* Set a zone in the read-only or offline condition.
*/
static void null_set_zone_cond(struct nullb_device *dev,
struct nullb_zone *zone, enum blk_zone_cond cond)
{
if (WARN_ON_ONCE(cond != BLK_ZONE_COND_READONLY &&
cond != BLK_ZONE_COND_OFFLINE))
return;
null_lock_zone(dev, zone);
/*
* If the read-only condition is requested again to zones already in
* read-only condition, restore back normal empty condition. Do the same
* if the offline condition is requested for offline zones. Otherwise,
* set the specified zone condition to the zones. Finish the zones
* beforehand to free up zone resources.
*/
if (zone->cond == cond) {
zone->cond = BLK_ZONE_COND_EMPTY;
zone->wp = zone->start;
if (dev->memory_backed)
null_handle_discard(dev, zone->start, zone->len);
} else {
if (zone->cond != BLK_ZONE_COND_READONLY &&
zone->cond != BLK_ZONE_COND_OFFLINE)
null_finish_zone(dev, zone);
zone->cond = cond;
zone->wp = (sector_t)-1;
}
null_unlock_zone(dev, zone);
}
/*
* Identify a zone from the sector written to configfs file. Then set zone
* condition to the zone.
*/
ssize_t zone_cond_store(struct nullb_device *dev, const char *page,
size_t count, enum blk_zone_cond cond)
{
unsigned long long sector;
unsigned int zone_no;
int ret;
if (!dev->zoned) {
pr_err("null_blk device is not zoned\n");
return -EINVAL;
}
if (!dev->zones) {
pr_err("null_blk device is not yet powered\n");
return -EINVAL;
}
ret = kstrtoull(page, 0, §or);
if (ret < 0)
return ret;
zone_no = null_zone_no(dev, sector);
if (zone_no >= dev->nr_zones) {
pr_err("Sector out of range\n");
return -EINVAL;
}
if (dev->zones[zone_no].type == BLK_ZONE_TYPE_CONVENTIONAL) {
pr_err("Can not change condition of conventional zones\n");
return -EINVAL;
}
null_set_zone_cond(dev, &dev->zones[zone_no], cond);
return count;
}
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