From b164316808ec5de391c3e7b0148ec937d32d280d Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Thu, 30 May 2024 14:40:32 +0900 Subject: [PATCH] null_blk: Do not allow runt zone with zone capacity smaller then zone size 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 Reviewed-by: Niklas Cassel Reviewed-by: Bart Van Assche Link: https://lore.kernel.org/r/20240530054035.491497-2-dlemoal@kernel.org Signed-off-by: Jens Axboe --- drivers/block/null_blk/zoned.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c index 79c8e5e99f7f..f118d304f310 100644 --- a/drivers/block/null_blk/zoned.c +++ b/drivers/block/null_blk/zoned.c @@ -74,6 +74,17 @@ int null_init_zoned_dev(struct nullb_device *dev, 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);