Add as module parameters these options: memory_backed discard mbps cache_size Previously these could only be set via configfs. Still missing is bad_blocks. The kernel test robot found a documentation formatting issue in v1 of this patch. Reported-by: kernel test robot <lkp@xxxxxxxxx> Signed-off-by: Vincent Fu <vincent.fu@xxxxxxxxxxx> --- Documentation/block/null_blk.rst | 22 ++++++++++++++++++++++ drivers/block/null_blk/main.c | 20 ++++++++++++++++++++ 2 files changed, 42 insertions(+) diff --git a/Documentation/block/null_blk.rst b/Documentation/block/null_blk.rst index edbbab2f1..4dd78f24d 100644 --- a/Documentation/block/null_blk.rst +++ b/Documentation/block/null_blk.rst @@ -72,6 +72,28 @@ submit_queues=[1..nr_cpus]: Default: 1 hw_queue_depth=[0..qdepth]: Default: 64 The hardware queue depth of the device. +memory_backed=[0/1]: Default: 0 + Whether or not to use a memory buffer to respond to IO requests + + = ============================================= + 0 Transfer no data in response to IO requests + 1 Use a memory buffer to respond to IO requests + = ============================================= + +discard=[0/1]: Default: 0 + Support discard operations (requires memory-backed null_blk device). + + = ===================================== + 0 Do not support discard operations + 1 Enable support for discard operations + = ===================================== + +cache_size=[Size in MB]: Default: 0 + Cache size in MB for memory-backed device. + +mbps=[Maximum bandwidth in MB/s]: Default: 0 (no limit) + Bandwidth limit for device performance. + Multi-queue specific parameters ------------------------------- diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index 3778df206..8f821fa94 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -201,6 +201,22 @@ static bool g_use_per_node_hctx; module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, 0444); MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); +static bool g_memory_backed; +module_param_named(memory_backed, g_memory_backed, bool, 0444); +MODULE_PARM_DESC(memory_backed, "Create a memory-backed block device. Default: false"); + +static bool g_discard; +module_param_named(discard, g_discard, bool, 0444); +MODULE_PARM_DESC(discard, "Support discard operations (requires memory-backed null_blk device). Default: false"); + +static unsigned long g_cache_size; +module_param_named(cache_size, g_cache_size, ulong, 0444); +MODULE_PARM_DESC(mbps, "Cache size in MiB for memory-backed device. Default: 0 (none)"); + +static unsigned int g_mbps; +module_param_named(mbps, g_mbps, uint, 0444); +MODULE_PARM_DESC(mbps, "Limit maximum bandwidth (in MiB/s). Default: 0 (no limit)"); + static bool g_zoned; module_param_named(zoned, g_zoned, bool, S_IRUGO); MODULE_PARM_DESC(zoned, "Make device as a host-managed zoned block device. Default: false"); @@ -650,6 +666,10 @@ static struct nullb_device *null_alloc_dev(void) dev->irqmode = g_irqmode; dev->hw_queue_depth = g_hw_queue_depth; dev->blocking = g_blocking; + dev->memory_backed = g_memory_backed; + dev->discard = g_discard; + dev->cache_size = g_cache_size; + dev->mbps = g_mbps; dev->use_per_node_hctx = g_use_per_node_hctx; dev->zoned = g_zoned; dev->zone_size = g_zone_size; -- 2.25.1
