This is a note to let you know that I've just added the patch titled null_blk: Do not allow runt zone with zone capacity smaller then zone size to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: null_blk-do-not-allow-runt-zone-with-zone-capacity-s.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e76cd6f118e37dd7f62520fab8276045c3142b04 Author: Damien Le Moal <dlemoal@xxxxxxxxxx> Date: Thu May 30 14:40:32 2024 +0900 null_blk: Do not allow runt zone with zone capacity smaller then zone size [ Upstream commit b164316808ec5de391c3e7b0148ec937d32d280d ] A zoned device with a smaller last zone together with a zone capacity smaller than the zone size does make any sense as that does not correspond to any possible setup for a real device: 1) For ZNS and zoned UFS devices, all zones are always the same size. 2) For SMR HDDs, all zones always have the same capacity. In other words, if we have a smaller last runt zone, then this zone capacity should always be equal to the zone size. Add a check in null_init_zoned_dev() to prevent a configuration to have both a smaller zone size and a zone capacity smaller than the zone size. Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx> Reviewed-by: Niklas Cassel <cassel@xxxxxxxxxx> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx> Link: https://lore.kernel.org/r/20240530054035.491497-2-dlemoal@xxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c index 0cdeafd9defcf..174d93a84137b 100644 --- a/drivers/block/null_blk/zoned.c +++ b/drivers/block/null_blk/zoned.c @@ -80,6 +80,17 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q) 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);