From: Kanchan Joshi Date: Mon, 28 Sep 2020 09:55:49 +0000 (+0530) Subject: null_blk: synchronization fix for zoned device X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=35bc10b2eafb;p=uclinux-h8%2Flinux.git null_blk: synchronization fix for zoned device 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 Reviewed-by: Damien Le Moal Signed-off-by: Jens Axboe --- diff --git a/drivers/block/null_blk.h b/drivers/block/null_blk.h index d2e7db43a52a..3176b269b822 100644 --- a/drivers/block/null_blk.h +++ b/drivers/block/null_blk.h @@ -47,6 +47,7 @@ struct nullb_device { unsigned int nr_zones_closed; 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 7d94f2d47a6a..98056c88926b 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", @@ -149,8 +150,11 @@ 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; @@ -499,18 +503,28 @@ 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; }