From f4f84586c8b9c7d5312d6f8fb4db1e12f2b83c27 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Mon, 8 Apr 2024 10:41:17 +0900 Subject: null_blk: Introduce fua attribute Add the fua configfs attribute and module parameter to allow configuring if the device supports FUA or not. Using this attribute has an effect on the null_blk device only if memory backing is enabled together with a write cache (cache_size option). This new attribute allows configuring a null_blk device with a write cache but without FUA support. This is convenient to test the block layer flush machinery. Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Reviewed-by: Chaitanya Kulkarni Tested-by: Hans Holmberg Tested-by: Dennis Maisenbacher Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20240408014128.205141-18-dlemoal@kernel.org Signed-off-by: Jens Axboe --- drivers/block/null_blk/main.c | 12 ++++++++++-- drivers/block/null_blk/null_blk.h | 1 + 2 files changed, 11 insertions(+), 2 deletions(-) (limited to 'drivers/block') diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index a5a50ba6ad9f..578660b1ad01 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -225,6 +225,10 @@ 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 bool g_fua = true; +module_param_named(fua, g_fua, bool, 0444); +MODULE_PARM_DESC(zoned, "Enable/disable FUA support when cache_size is used. Default: true"); + 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)"); @@ -446,6 +450,7 @@ NULLB_DEVICE_ATTR(virt_boundary, bool, NULL); NULLB_DEVICE_ATTR(no_sched, bool, NULL); NULLB_DEVICE_ATTR(shared_tags, bool, NULL); NULLB_DEVICE_ATTR(shared_tag_bitmap, bool, NULL); +NULLB_DEVICE_ATTR(fua, bool, NULL); static ssize_t nullb_device_power_show(struct config_item *item, char *page) { @@ -593,6 +598,7 @@ static struct configfs_attribute *nullb_device_attrs[] = { &nullb_device_attr_no_sched, &nullb_device_attr_shared_tags, &nullb_device_attr_shared_tag_bitmap, + &nullb_device_attr_fua, NULL, }; @@ -671,7 +677,7 @@ nullb_group_drop_item(struct config_group *group, struct config_item *item) static ssize_t memb_group_features_show(struct config_item *item, char *page) { return snprintf(page, PAGE_SIZE, - "badblocks,blocking,blocksize,cache_size," + "badblocks,blocking,blocksize,cache_size,fua," "completion_nsec,discard,home_node,hw_queue_depth," "irqmode,max_sectors,mbps,memory_backed,no_sched," "poll_queues,power,queue_mode,shared_tag_bitmap," @@ -763,6 +769,8 @@ static struct nullb_device *null_alloc_dev(void) dev->no_sched = g_no_sched; dev->shared_tags = g_shared_tags; dev->shared_tag_bitmap = g_shared_tag_bitmap; + dev->fua = g_fua; + return dev; } @@ -1920,7 +1928,7 @@ static int null_add_dev(struct nullb_device *dev) if (dev->cache_size > 0) { set_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags); - blk_queue_write_cache(nullb->q, true, true); + blk_queue_write_cache(nullb->q, true, dev->fua); } nullb->q->queuedata = nullb; diff --git a/drivers/block/null_blk/null_blk.h b/drivers/block/null_blk/null_blk.h index a9c5df650ddb..3234e6c85eed 100644 --- a/drivers/block/null_blk/null_blk.h +++ b/drivers/block/null_blk/null_blk.h @@ -105,6 +105,7 @@ struct nullb_device { bool no_sched; /* no IO scheduler for the device */ bool shared_tags; /* share tag set between devices for blk-mq */ bool shared_tag_bitmap; /* use hostwide shared tags */ + bool fua; /* Support FUA */ }; struct nullb { -- cgit v1.2.3