// SPDX-License-Identifier: GPL-2.0 #include #include #include "null_blk.h" #define CREATE_TRACE_POINTS #include "trace.h" #undef pr_fmt #define pr_fmt(fmt) "null_blk: " fmt #define NULL_ZONE_INVALID_WP ((sector_t)-1) 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_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; } 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); } dev->zone_append_max_sectors = min(ALIGN_DOWN(dev->zone_append_max_sectors, dev->blocksize >> SECTOR_SHIFT), zone_capacity_sects); /* 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->nr_zones); } 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_append_max_sectors; 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; struct gendisk *disk = nullb->disk; blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); disk->nr_zones = bdev_nr_zones(disk->part0); pr_info("%s: using %s zone append\n", disk->disk_name, queue_emulates_zone_append(q) ? "emulated" : "native"); return blk_revalidate_disk_zones(disk); } 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 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) { dev->nr_zones_imp_open--; if (zone->wp == zone->start) { zone->cond = BLK_ZONE_COND_EMPTY; } else { zone->cond = BLK_ZONE_COND_CLOSED; dev->nr_zones_closed++; } 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); /* * 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 sector. Note that we do not check the zone * condition because for FULL, READONLY and OFFLINE zones, the sector * check against the zone write pointer will always result in failing * the command. */ if (append) { if (WARN_ON_ONCE(!dev->zone_append_max_sectors) || zone->wp == NULL_ZONE_INVALID_WP) { ret = BLK_STS_IOERR; goto unlock_zone; } sector = zone->wp; blk_mq_rq_from_pdu(cmd)->__sector = sector; } if (sector != zone->wp || zone->wp + nr_sectors > zone->start + zone->capacity) { ret = BLK_STS_IOERR; goto unlock_zone; } if (zone->cond == BLK_ZONE_COND_CLOSED || zone->cond == BLK_ZONE_COND_EMPTY) { if (dev->need_zone_res_mgmt) { spin_lock(&dev->zone_res_lock); ret = null_check_zone_resources(dev, zone); if (ret != BLK_STS_OK) { spin_unlock(&dev->zone_res_lock); goto unlock_zone; } 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++; } spin_unlock(&dev->zone_res_lock); } zone->cond = BLK_ZONE_COND_IMP_OPEN; } ret = null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors); if (ret != BLK_STS_OK) goto unlock_zone; zone->wp += nr_sectors; if (zone->wp == zone->start + zone->capacity) { if (dev->need_zone_res_mgmt) { spin_lock(&dev->zone_res_lock); 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--; spin_unlock(&dev->zone_res_lock); } zone->cond = BLK_ZONE_COND_FULL; } ret = BLK_STS_OK; unlock_zone: 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; switch (zone->cond) { case BLK_ZONE_COND_EXP_OPEN: /* Open operation on exp open is not an error */ return BLK_STS_OK; case BLK_ZONE_COND_EMPTY: case BLK_ZONE_COND_IMP_OPEN: case BLK_ZONE_COND_CLOSED: break; case BLK_ZONE_COND_FULL: default: return BLK_STS_IOERR; } if (dev->need_zone_res_mgmt) { spin_lock(&dev->zone_res_lock); switch (zone->cond) { case BLK_ZONE_COND_EMPTY: ret = null_check_zone_resources(dev, zone); if (ret != BLK_STS_OK) { spin_unlock(&dev->zone_res_lock); return ret; } 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) { spin_unlock(&dev->zone_res_lock); return ret; } dev->nr_zones_closed--; break; default: break; } dev->nr_zones_exp_open++; spin_unlock(&dev->zone_res_lock); } zone->cond = BLK_ZONE_COND_EXP_OPEN; return BLK_STS_OK; } static blk_status_t null_close_zone(struct nullb_device *dev, struct nullb_zone *zone) { if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) return BLK_STS_IOERR; 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: case BLK_ZONE_COND_EXP_OPEN: break; case BLK_ZONE_COND_EMPTY: case BLK_ZONE_COND_FULL: default: return BLK_STS_IOERR; } if (dev->need_zone_res_mgmt) { spin_lock(&dev->zone_res_lock); switch (zone->cond) { case BLK_ZONE_COND_IMP_OPEN: dev->nr_zones_imp_open--; break; case BLK_ZONE_COND_EXP_OPEN: dev->nr_zones_exp_open--; break; default: break; } if (zone->wp > zone->start) dev->nr_zones_closed++; spin_unlock(&dev->zone_res_lock); } if (zone->wp == zone->start) zone->cond = BLK_ZONE_COND_EMPTY; else zone->cond = BLK_ZONE_COND_CLOSED; return BLK_STS_OK; } 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; if (dev->need_zone_res_mgmt) { spin_lock(&dev->zone_res_lock); switch (zone->cond) { case BLK_ZONE_COND_FULL: /* Finish operation on full is not an error */ spin_unlock(&dev->zone_res_lock); return BLK_STS_OK; case BLK_ZONE_COND_EMPTY: ret = null_check_zone_resources(dev, zone); if (ret != BLK_STS_OK) { spin_unlock(&dev->zone_res_lock); return ret; } 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) { spin_unlock(&dev->zone_res_lock); return ret; } dev->nr_zones_closed--; break; default: spin_unlock(&dev->zone_res_lock); return BLK_STS_IOERR; } spin_unlock(&dev->zone_res_lock); } zone->cond = BLK_ZONE_COND_FULL; zone->wp = zone->start + zone->len; return BLK_STS_OK; } 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; if (dev->need_zone_res_mgmt) { spin_lock(&dev->zone_res_lock); switch (zone->cond) { 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_EMPTY: case BLK_ZONE_COND_FULL: break; default: spin_unlock(&dev->zone_res_lock); return BLK_STS_IOERR; } spin_unlock(&dev->zone_res_lock); } zone->cond = BLK_ZONE_COND_EMPTY; zone->wp = zone->start; 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 = NULL_ZONE_INVALID_WP; } 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; }