null_blk: add configfs variables for 2 options

Allow setting via configfs these two options:

no_sched
shared_tag_bitmap

Previously these could only be activated as module parameters.

Still missing are:

shared_tags
timeout
requeue
init_hctx

Signed-off-by: Vincent Fu <vincent.fu@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220708174943.87787-3-vincent.fu@samsung.com
[axboe: fold in nullb == NULL fix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index b056574..c796abc 100644 (file)
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -425,6 +425,8 @@ NULLB_DEVICE_ATTR(zone_nr_conv, uint, NULL);
 NULLB_DEVICE_ATTR(zone_max_open, uint, NULL);
 NULLB_DEVICE_ATTR(zone_max_active, uint, NULL);
 NULLB_DEVICE_ATTR(virt_boundary, bool, NULL);
+NULLB_DEVICE_ATTR(no_sched, bool, NULL);
+NULLB_DEVICE_ATTR(shared_tag_bitmap, bool, NULL);
 
 static ssize_t nullb_device_power_show(struct config_item *item, char *page)
 {
@@ -548,6 +550,8 @@ static struct configfs_attribute *nullb_device_attrs[] = {
        &nullb_device_attr_zone_max_open,
        &nullb_device_attr_zone_max_active,
        &nullb_device_attr_virt_boundary,
+       &nullb_device_attr_no_sched,
+       &nullb_device_attr_shared_tag_bitmap,
        NULL,
 };
 
@@ -604,7 +608,13 @@ 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,
-                       "memory_backed,discard,bandwidth,cache,badblocks,zoned,zone_size,zone_capacity,zone_nr_conv,zone_max_open,zone_max_active,blocksize,max_sectors,virt_boundary\n");
+                       "badblocks,blocking,blocksize,cache_size,"
+                       "completion_nsec,discard,home_node,hw_queue_depth,"
+                       "irqmode,max_sectors,mbps,memory_backed,no_sched,"
+                       "poll_queues,power,queue_mode,shared_tag_bitmap,size,"
+                       "submit_queues,use_per_node_hctx,virt_boundary,zoned,"
+                       "zone_capacity,zone_max_active,zone_max_open,"
+                       "zone_nr_conv,zone_size\n");
 }
 
 CONFIGFS_ATTR_RO(memb_group_, features);
@@ -678,6 +688,8 @@ static struct nullb_device *null_alloc_dev(void)
        dev->zone_max_open = g_zone_max_open;
        dev->zone_max_active = g_zone_max_active;
        dev->virt_boundary = g_virt_boundary;
+       dev->no_sched = g_no_sched;
+       dev->shared_tag_bitmap = g_shared_tag_bitmap;
        return dev;
 }
 
@@ -1885,31 +1897,48 @@ static int null_gendisk_register(struct nullb *nullb)
 
 static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
 {
+       unsigned int flags = BLK_MQ_F_SHOULD_MERGE;
+       int hw_queues, numa_node;
+       unsigned int queue_depth;
        int poll_queues;
 
+       if (nullb) {
+               hw_queues = nullb->dev->submit_queues;
+               poll_queues = nullb->dev->poll_queues;
+               queue_depth = nullb->dev->hw_queue_depth;
+               numa_node = nullb->dev->home_node;
+               if (nullb->dev->no_sched)
+                       flags |= BLK_MQ_F_NO_SCHED;
+               if (nullb->dev->shared_tag_bitmap)
+                       flags |= BLK_MQ_F_TAG_HCTX_SHARED;
+               if (nullb->dev->blocking)
+                       flags |= BLK_MQ_F_BLOCKING;
+       } else {
+               hw_queues = g_submit_queues;
+               poll_queues = g_poll_queues;
+               queue_depth = g_hw_queue_depth;
+               numa_node = g_home_node;
+               if (g_no_sched)
+                       flags |= BLK_MQ_F_NO_SCHED;
+               if (g_shared_tag_bitmap)
+                       flags |= BLK_MQ_F_TAG_HCTX_SHARED;
+               if (g_blocking)
+                       flags |= BLK_MQ_F_BLOCKING;
+       }
+
        set->ops = &null_mq_ops;
-       set->nr_hw_queues = nullb ? nullb->dev->submit_queues :
-                                               g_submit_queues;
-       poll_queues = nullb ? nullb->dev->poll_queues : g_poll_queues;
-       if (poll_queues)
-               set->nr_hw_queues += poll_queues;
-       set->queue_depth = nullb ? nullb->dev->hw_queue_depth :
-                                               g_hw_queue_depth;
-       set->numa_node = nullb ? nullb->dev->home_node : g_home_node;
        set->cmd_size   = sizeof(struct nullb_cmd);
-       set->flags = BLK_MQ_F_SHOULD_MERGE;
-       if (g_no_sched)
-               set->flags |= BLK_MQ_F_NO_SCHED;
-       if (g_shared_tag_bitmap)
-               set->flags |= BLK_MQ_F_TAG_HCTX_SHARED;
+       set->flags = flags;
        set->driver_data = nullb;
-       if (poll_queues)
+       set->nr_hw_queues = hw_queues;
+       set->queue_depth = queue_depth;
+       set->numa_node = numa_node;
+       if (poll_queues) {
+               set->nr_hw_queues += poll_queues;
                set->nr_maps = 3;
-       else
+       } else {
                set->nr_maps = 1;
-
-       if ((nullb && nullb->dev->blocking) || g_blocking)
-               set->flags |= BLK_MQ_F_BLOCKING;
+       }
 
        return blk_mq_alloc_tag_set(set);
 }

diff --git a/drivers/block/null_blk/null_blk.h b/drivers/block/null_blk/null_blk.h
index 6fbf0a1..94ff680 100644 (file)
--- a/drivers/block/null_blk/null_blk.h
+++ b/drivers/block/null_blk/null_blk.h
@@ -113,6 +113,8 @@ struct nullb_device {
        bool discard; /* if support discard */
        bool zoned; /* if device is zoned */
        bool virt_boundary; /* virtual boundary on/off for the device */
+       bool no_sched; /* no IO scheduler for the device */
+       bool shared_tag_bitmap; /* use hostwide shared tags */
 };
 
 struct nullb {