From: Kanchan Joshi joshi.k@samsung.com
commit 35bc10b2eafbb701064b94f283b77c54d3304842 upstream.
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.
Cc: stable@vger.kernel.org Fixes: e0489ed5daeb ("null_blk: Support REQ_OP_ZONE_APPEND") Signed-off-by: Kanchan Joshi joshi.k@samsung.com Reviewed-by: Damien Le Moal damien.lemoal@wdc.com Signed-off-by: Jens Axboe axboe@kernel.dk --- drivers/block/null_blk.h | 1 + drivers/block/null_blk_zoned.c | 22 ++++++++++++++++++---- 2 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/drivers/block/null_blk.h b/drivers/block/null_blk.h index daed4a9c3436..28099be50395 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 zone_lock;
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..e8d8b13aaa5a 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->zone_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", @@ -131,8 +132,11 @@ int null_report_zones(struct gendisk *disk, sector_t sector, * So use a local copy to avoid corruption of the device zone * array. */ + spin_lock_irq(&dev->zone_lock); memcpy(&zone, &dev->zones[first_zone + i], sizeof(struct blk_zone)); + spin_unlock_irq(&dev->zone_lock); + error = cb(&zone, i, data); if (error) return error; @@ -277,18 +281,28 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op, blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_opf op, sector_t sector, sector_t nr_sectors) { + blk_status_t sts; + struct nullb_device *dev = cmd->nq->dev; + + spin_lock_irq(&dev->zone_lock); switch (op) { case REQ_OP_WRITE: - return null_zone_write(cmd, sector, nr_sectors, false); + sts = null_zone_write(cmd, sector, nr_sectors, false); + break; case REQ_OP_ZONE_APPEND: - return null_zone_write(cmd, sector, nr_sectors, true); + sts = null_zone_write(cmd, sector, nr_sectors, true); + break; 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); + sts = null_zone_mgmt(cmd, op, sector); + break; default: - return null_process_cmd(cmd, op, sector, nr_sectors); + sts = null_process_cmd(cmd, op, sector, nr_sectors); } + spin_unlock_irq(&dev->zone_lock); + + return sts; }