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 --- include/linux/blk-mq.h | 3 +-- include/linux/blkdev.h | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 3a41d50b85d3..7aa5c54901a9 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -917,8 +917,7 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq) } #define queue_for_each_hw_ctx(q, hctx, i) \ - for ((i) = 0; (i) < (q)->nr_hw_queues && \ - ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++) + xa_for_each(&(q)->hctx_table, (i), (hctx)) #define hctx_for_each_ctx(hctx, ctx, i) \ for ((i) = 0; (i) < (hctx)->nr_ctx && \ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e19947d84f12..d982171469bc 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -355,7 +355,7 @@ struct request_queue { unsigned int queue_depth; /* hw dispatch queues */ - struct blk_mq_hw_ctx **queue_hw_ctx; + struct xarray hctx_table; unsigned int nr_hw_queues; /* -- cgit v1.2.3