blk-mq: register cpuhp callback after hctx is added to xarray table

We need to retrieve 'hctx' from xarray table in the cpuhp callback, so the
callback should be registered after this 'hctx' is added to xarray table.

Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Newman <peternewman@google.com>
Cc: Babu Moger <babu.moger@amd.com>
Cc: Luck Tony <tony.luck@intel.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20241206111611.978870-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 424239c075e28c301d0d17e03bf114bc8f582780..a404465036de3fa7cffa430d99d57cdd32efb83d 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3824,16 +3824,11 @@ static int blk_mq_init_hctx(struct request_queue *q,
 {
        hctx->queue_num = hctx_idx;
 
-       if (!(hctx->flags & BLK_MQ_F_STACKING))
-               cpuhp_state_add_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE,
-                               &hctx->cpuhp_online);
-       cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead);
-
        hctx->tags = set->tags[hctx_idx];
 
        if (set->ops->init_hctx &&
            set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
-               goto unregister_cpu_notifier;
+               goto fail;
 
        if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx,
                                hctx->numa_node))
@@ -3842,6 +3837,11 @@ static int blk_mq_init_hctx(struct request_queue *q,
        if (xa_insert(&q->hctx_table, hctx_idx, hctx, GFP_KERNEL))
                goto exit_flush_rq;
 
+       if (!(hctx->flags & BLK_MQ_F_STACKING))
+               cpuhp_state_add_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE,
+                               &hctx->cpuhp_online);
+       cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead);
+
        return 0;
 
  exit_flush_rq:
@@ -3850,8 +3850,7 @@ static int blk_mq_init_hctx(struct request_queue *q,
  exit_hctx:
        if (set->ops->exit_hctx)
                set->ops->exit_hctx(hctx, hctx_idx);
- unregister_cpu_notifier:
-       blk_mq_remove_cpuhp(hctx);
+ fail:
        return -1;
 }