From 4e5cc99e1e485954a9c09872e0eeea570fb2b5a5 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 8 Mar 2022 15:32:19 +0800 Subject: blk-mq: manage hctx map via xarray First code becomes more clean by switching to xarray from plain array. Second use-after-free on q->queue_hw_ctx can be fixed because queue_for_each_hw_ctx() may be run when updating nr_hw_queues is in-progress. With this patch, q->hctx_table is defined as xarray, and this structure will share same lifetime with request queue, so queue_for_each_hw_ctx() can use q->hctx_table to lookup hctx reliably. Reported-by: Yu Kuai Signed-off-by: Ming Lei Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220308073219.91173-7-ming.lei@redhat.com [axboe: fix blk_mq_hw_ctx forward declaration] Signed-off-by: Jens Axboe --- block/blk-mq.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'block/blk-mq.h') diff --git a/block/blk-mq.h b/block/blk-mq.h index 948791ea2a3e..2615bd58bad3 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -83,7 +83,7 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue * enum hctx_type type, unsigned int cpu) { - return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]]; + return xa_load(&q->hctx_table, q->tag_set->map[type].mq_map[cpu]); } static inline enum hctx_type blk_mq_get_hctx_type(unsigned int flags) -- cgit v1.2.3