blk-mq: allow blk_mq_init_commands() to return failure

If drivers do dynamic allocation in the hardware command init
path, then we need to be able to handle and return failures.

And if they do allocations or mappings in the init command path,
then we need a cleanup function to free up that space at exit
time. So add blk_mq_free_commands() as the cleanup function.

This is required for the mtip32xx driver conversion to blk-mq.

Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index b1cb3f4c4db4..0eace43cea11 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -490,13 +490,14 @@ static struct blk_mq_reg virtio_mq_reg = {
         .flags          = BLK_MQ_F_SHOULD_MERGE,
 };
 
-static void virtblk_init_vbr(void *data, struct blk_mq_hw_ctx *hctx,
+static int virtblk_init_vbr(void *data, struct blk_mq_hw_ctx *hctx,
                              struct request *rq, unsigned int nr)
 {
         struct virtio_blk *vblk = data;
         struct virtblk_req *vbr = rq->special;
 
         sg_init_table(vbr->sg, vblk->sg_elems);
+        return 0;
 }
 
 static int virtblk_probe(struct virtio_device *vdev)