Parallel write,read,zone-mgmt operations accessing/altering zone state and write-pointer may get into race. Avoid the situation by using a new spinlock for zoned device. Concurrent zone-appends (on a zone) returning same write-pointer issue is also avoided using this lock.
Signed-off-by: Kanchan Joshi <[email protected]> --- drivers/block/null_blk.h | 1 + drivers/block/null_blk_zoned.c | 84 +++++++++++++++++++++++----------- 2 files changed, 58 insertions(+), 27 deletions(-) diff --git a/drivers/block/null_blk.h b/drivers/block/null_blk.h index daed4a9c3436..b3f4d62e7c38 100644 --- a/drivers/block/null_blk.h +++ b/drivers/block/null_blk.h @@ -44,6 +44,7 @@ struct nullb_device { unsigned int nr_zones; struct blk_zone *zones; sector_t zone_size_sects; + spinlock_t zlock; unsigned long size; /* device size in MB */ unsigned long completion_nsec; /* time in ns to complete a request */ diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c index 3d25c9ad2383..04fbf267703a 100644 --- a/drivers/block/null_blk_zoned.c +++ b/drivers/block/null_blk_zoned.c @@ -45,6 +45,7 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q) if (!dev->zones) return -ENOMEM; + spin_lock_init(&dev->zlock); 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", @@ -124,6 +125,7 @@ int null_report_zones(struct gendisk *disk, sector_t sector, nr_zones = min(nr_zones, dev->nr_zones - first_zone); trace_nullb_report_zones(nullb, nr_zones); + spin_lock_irq(&dev->zlock); for (i = 0; i < nr_zones; i++) { /* * Stacked DM target drivers will remap the zone information by @@ -134,10 +136,13 @@ int null_report_zones(struct gendisk *disk, sector_t sector, memcpy(&zone, &dev->zones[first_zone + i], sizeof(struct blk_zone)); error = cb(&zone, i, data); - if (error) + if (error) { + spin_unlock_irq(&dev->zlock); return error; + } } + spin_unlock_irq(&dev->zlock); return nr_zones; } @@ -147,16 +152,24 @@ size_t null_zone_valid_read_len(struct nullb *nullb, struct nullb_device *dev = nullb->dev; struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)]; unsigned int nr_sectors = len >> SECTOR_SHIFT; + size_t ret = 0; + spin_lock_irq(&dev->zlock); /* Read must be below the write pointer position */ if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL || - sector + nr_sectors <= zone->wp) - return len; + sector + nr_sectors <= zone->wp) { + ret = len; + goto out_unlock; + } if (sector > zone->wp) - return 0; + goto out_unlock; + + ret = (zone->wp - sector) << SECTOR_SHIFT; - return (zone->wp - sector) << SECTOR_SHIFT; +out_unlock: + spin_unlock_irq(&dev->zlock); + return ret; } static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector, @@ -165,17 +178,19 @@ static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector, struct nullb_device *dev = cmd->nq->dev; unsigned int zno = null_zone_no(dev, sector); struct blk_zone *zone = &dev->zones[zno]; - blk_status_t ret; + blk_status_t ret = BLK_STS_OK; trace_nullb_zone_op(cmd, zno, zone->cond); if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) return null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors); + spin_lock_irq(&dev->zlock); switch (zone->cond) { case BLK_ZONE_COND_FULL: /* Cannot write to a full zone */ - return BLK_STS_IOERR; + ret = BLK_STS_IOERR; + break; case BLK_ZONE_COND_EMPTY: case BLK_ZONE_COND_IMP_OPEN: case BLK_ZONE_COND_EXP_OPEN: @@ -193,27 +208,33 @@ static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector, else cmd->rq->__sector = sector; } else if (sector != zone->wp) { - return BLK_STS_IOERR; + ret = BLK_STS_IOERR; + break; } - if (zone->wp + nr_sectors > zone->start + zone->capacity) - return BLK_STS_IOERR; + if (zone->wp + nr_sectors > zone->start + zone->capacity) { + ret = BLK_STS_IOERR; + break; + } if (zone->cond != BLK_ZONE_COND_EXP_OPEN) zone->cond = BLK_ZONE_COND_IMP_OPEN; ret = null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors); if (ret != BLK_STS_OK) - return ret; + break; zone->wp += nr_sectors; if (zone->wp == zone->start + zone->capacity) zone->cond = BLK_ZONE_COND_FULL; - return BLK_STS_OK; + break; default: /* Invalid zone condition */ - return BLK_STS_IOERR; + ret = BLK_STS_IOERR; } + + spin_unlock_irq(&dev->zlock); + return ret; } static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op, @@ -223,7 +244,9 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op, unsigned int zone_no = null_zone_no(dev, sector); struct blk_zone *zone = &dev->zones[zone_no]; size_t i; + blk_status_t ret = BLK_STS_OK; + spin_lock_irq(&dev->zlock); switch (op) { case REQ_OP_ZONE_RESET_ALL: for (i = 0; i < dev->nr_zones; i++) { @@ -234,25 +257,29 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op, } break; case REQ_OP_ZONE_RESET: - if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) - return BLK_STS_IOERR; + if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) { + ret = BLK_STS_IOERR; + break; + } zone->cond = BLK_ZONE_COND_EMPTY; zone->wp = zone->start; break; case REQ_OP_ZONE_OPEN: - if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) - return BLK_STS_IOERR; - if (zone->cond == BLK_ZONE_COND_FULL) - return BLK_STS_IOERR; + if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL || + zone->cond == BLK_ZONE_COND_FULL) { + ret = BLK_STS_IOERR; + break; + } zone->cond = BLK_ZONE_COND_EXP_OPEN; break; case REQ_OP_ZONE_CLOSE: - if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) - return BLK_STS_IOERR; - if (zone->cond == BLK_ZONE_COND_FULL) - return BLK_STS_IOERR; + if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL || + zone->cond == BLK_ZONE_COND_FULL) { + ret = BLK_STS_IOERR; + break; + } if (zone->wp == zone->start) zone->cond = BLK_ZONE_COND_EMPTY; @@ -260,18 +287,21 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op, zone->cond = BLK_ZONE_COND_CLOSED; break; case REQ_OP_ZONE_FINISH: - if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) - return BLK_STS_IOERR; + if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) { + ret = BLK_STS_IOERR; + break; + } zone->cond = BLK_ZONE_COND_FULL; zone->wp = zone->start + zone->len; break; default: - return BLK_STS_NOTSUPP; + ret = BLK_STS_NOTSUPP; } + spin_unlock_irq(&dev->zlock); trace_nullb_zone_op(cmd, zone_no, zone->cond); - return BLK_STS_OK; + return ret; } blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_opf op, -- 2.25.1
