blk-mq: split out tag initialization, support shared tags
Add a new blk_mq_tag_set structure that gets set up before we initialize
the queue. A single blk_mq_tag_set structure can be shared by multiple
queues.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Modular export of blk_mq_{alloc,free}_tagset added by me.
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index d06206a..f909a88 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -30,6 +30,9 @@
/* The disk structure for the kernel. */
struct gendisk *disk;
+ /* Block layer tags. */
+ struct blk_mq_tag_set tag_set;
+
/* Process context for config space updates */
struct work_struct config_work;
@@ -480,8 +483,9 @@
__ATTR(cache_type, S_IRUGO|S_IWUSR,
virtblk_cache_type_show, virtblk_cache_type_store);
-static int virtblk_init_request(void *data, struct blk_mq_hw_ctx *hctx,
- struct request *rq, unsigned int nr)
+static int virtblk_init_request(void *data, struct request *rq,
+ unsigned int hctx_idx, unsigned int request_idx,
+ unsigned int numa_node)
{
struct virtio_blk *vblk = data;
struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
@@ -495,18 +499,12 @@
.map_queue = blk_mq_map_queue,
.alloc_hctx = blk_mq_alloc_single_hw_queue,
.free_hctx = blk_mq_free_single_hw_queue,
- .init_request = virtblk_init_request,
.complete = virtblk_request_done,
+ .init_request = virtblk_init_request,
};
-static struct blk_mq_reg virtio_mq_reg = {
- .ops = &virtio_mq_ops,
- .nr_hw_queues = 1,
- .queue_depth = 0, /* Set in virtblk_probe */
- .numa_node = NUMA_NO_NODE,
- .flags = BLK_MQ_F_SHOULD_MERGE,
-};
-module_param_named(queue_depth, virtio_mq_reg.queue_depth, uint, 0444);
+static unsigned int virtblk_queue_depth;
+module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
static int virtblk_probe(struct virtio_device *vdev)
{
@@ -562,20 +560,32 @@
}
/* Default queue sizing is to fill the ring. */
- if (!virtio_mq_reg.queue_depth) {
- virtio_mq_reg.queue_depth = vblk->vq->num_free;
+ if (!virtblk_queue_depth) {
+ virtblk_queue_depth = vblk->vq->num_free;
/* ... but without indirect descs, we use 2 descs per req */
if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
- virtio_mq_reg.queue_depth /= 2;
+ virtblk_queue_depth /= 2;
}
- virtio_mq_reg.cmd_size =
+
+ memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
+ vblk->tag_set.ops = &virtio_mq_ops;
+ vblk->tag_set.nr_hw_queues = 1;
+ vblk->tag_set.queue_depth = virtblk_queue_depth;
+ vblk->tag_set.numa_node = NUMA_NO_NODE;
+ vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+ vblk->tag_set.cmd_size =
sizeof(struct virtblk_req) +
sizeof(struct scatterlist) * sg_elems;
+ vblk->tag_set.driver_data = vblk;
- q = vblk->disk->queue = blk_mq_init_queue(&virtio_mq_reg, vblk);
+ err = blk_mq_alloc_tag_set(&vblk->tag_set);
+ if (err)
+ goto out_put_disk;
+
+ q = vblk->disk->queue = blk_mq_init_queue(&vblk->tag_set);
if (!q) {
err = -ENOMEM;
- goto out_put_disk;
+ goto out_free_tags;
}
q->queuedata = vblk;
@@ -678,6 +688,8 @@
out_del_disk:
del_gendisk(vblk->disk);
blk_cleanup_queue(vblk->disk->queue);
+out_free_tags:
+ blk_mq_free_tag_set(&vblk->tag_set);
out_put_disk:
put_disk(vblk->disk);
out_free_vq:
@@ -704,6 +716,8 @@
del_gendisk(vblk->disk);
blk_cleanup_queue(vblk->disk->queue);
+ blk_mq_free_tag_set(&vblk->tag_set);
+
/* Stop all the virtqueues. */
vdev->config->reset(vdev);