[PATCH 25/30] xen-blkfront: use blk_mq_alloc_disk and blk_cleanup_disk

Christoph Hellwig
2021-06-02T06:56:30Z

Use blk_mq_alloc_disk and blk_cleanup_disk to simplify the gendisk and
request_queue allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/block/xen-blkfront.c | 96 +++++++++++++++---------------------
1 file changed, 39 insertions(+), 57 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index f2c1aedcdf5a..8d49f8fa98bb 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -968,48 +968,6 @@ static void blkif_set_queue_limits(struct blkfront_info *info)
blk_queue_dma_alignment(rq, 511);
}

-static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
- unsigned int physical_sector_size)
-{
- struct request_queue *rq;
- struct blkfront_info *info = gd->private_data;
-
- memset(&info->tag_set, 0, sizeof(info->tag_set));
- info->tag_set.ops = &blkfront_mq_ops;
- info->tag_set.nr_hw_queues = info->nr_rings;
- if (HAS_EXTRA_REQ && info->max_indirect_segments == 0) {
- /*
- * When indirect descriptior is not supported, the I/O request
- * will be split between multiple request in the ring.
- * To avoid problems when sending the request, divide by
- * 2 the depth of the queue.
- */
- info->tag_set.queue_depth = BLK_RING_SIZE(info) / 2;
- } else
- info->tag_set.queue_depth = BLK_RING_SIZE(info);
- info->tag_set.numa_node = NUMA_NO_NODE;
- info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
- info->tag_set.cmd_size = sizeof(struct blkif_req);
- info->tag_set.driver_data = info;
-
- if (blk_mq_alloc_tag_set(&info->tag_set))
- return -EINVAL;
- rq = blk_mq_init_queue(&info->tag_set);
- if (IS_ERR(rq)) {
- blk_mq_free_tag_set(&info->tag_set);
- return PTR_ERR(rq);
- }
-
- rq->queuedata = info;
- info->rq = gd->queue = rq;
- info->gd = gd;
- info->sector_size = sector_size;
- info->physical_sector_size = physical_sector_size;
- blkif_set_queue_limits(info);
-
- return 0;
-}
-
static const char *flush_info(struct blkfront_info *info)
{
if (info->feature_flush && info->feature_fua)
@@ -1146,12 +1104,36 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,

err = xlbd_reserve_minors(minor, nr_minors);
if (err)
- goto out;
+ return err;
err = -ENODEV;

- gd = alloc_disk(nr_minors);
- if (gd == NULL)
- goto release;
+ memset(&info->tag_set, 0, sizeof(info->tag_set));
+ info->tag_set.ops = &blkfront_mq_ops;
+ info->tag_set.nr_hw_queues = info->nr_rings;
+ if (HAS_EXTRA_REQ && info->max_indirect_segments == 0) {
+ /*
+ * When indirect descriptior is not supported, the I/O request
+ * will be split between multiple request in the ring.
+ * To avoid problems when sending the request, divide by
+ * 2 the depth of the queue.
+ */
+ info->tag_set.queue_depth = BLK_RING_SIZE(info) / 2;
+ } else
+ info->tag_set.queue_depth = BLK_RING_SIZE(info);
+ info->tag_set.numa_node = NUMA_NO_NODE;
+ info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+ info->tag_set.cmd_size = sizeof(struct blkif_req);
+ info->tag_set.driver_data = info;
+
+ err = blk_mq_alloc_tag_set(&info->tag_set);
+ if (err)
+ goto out_release_minors;
+
+ gd = blk_mq_alloc_disk(&info->tag_set, info);
+ if (IS_ERR(gd)) {
+ err = PTR_ERR(gd);
+ goto out_free_tag_set;
+ }

strcpy(gd->disk_name, DEV_NAME);
ptr = encode_disk_name(gd->disk_name + sizeof(DEV_NAME) - 1, offset);
@@ -1164,14 +1146,16 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,

gd->major = XENVBD_MAJOR;
gd->first_minor = minor;
+ gd->minors = nr_minors;
gd->fops = &xlvbd_block_fops;
gd->private_data = info;
set_capacity(gd, capacity);

- if (xlvbd_init_blk_queue(gd, sector_size, physical_sector_size)) {
- del_gendisk(gd);
- goto release;
- }
+ info->rq = gd->queue;
+ info->gd = gd;
+ info->sector_size = sector_size;
+ info->physical_sector_size = physical_sector_size;
+ blkif_set_queue_limits(info);

xlvbd_flush(info);

@@ -1186,9 +1170,10 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,

return 0;

- release:
+out_free_tag_set:
+ blk_mq_free_tag_set(&info->tag_set);
+out_release_minors:
xlbd_release_minors(minor, nr_minors);
- out:
return err;
}

@@ -1217,12 +1202,9 @@ static void xlvbd_release_gendisk(struct blkfront_info *info)
nr_minors = info->gd->minors;
xlbd_release_minors(minor, nr_minors);

- blk_cleanup_queue(info->rq);
- blk_mq_free_tag_set(&info->tag_set);
- info->rq = NULL;
-
- put_disk(info->gd);
+ blk_cleanup_disk(info->gd);
info->gd = NULL;
+ blk_mq_free_tag_set(&info->tag_set);
}

/* Already hold rinfo->ring_lock. */
--
2.30.2