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authorMing Lei <ming.lei@redhat.com>2022-03-08 15:32:19 +0800
committerJens Axboe <axboe@kernel.dk>2022-03-08 19:39:38 -0700
commit4e5cc99e1e485954a9c09872e0eeea570fb2b5a5 (patch)
treea48a03ee09ac2cad11e39b6d435080229b649f73 /block/blk-mq-tag.c
parent4f481208749a22d3570073e629dbc27d7d27c8da (diff)
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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 <yukuai3@huawei.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> 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 <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq-tag.c')
-rw-r--r--block/blk-mq-tag.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 1850a4225e12..68ac23d0b640 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -498,7 +498,7 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_tag_iter_fn *fn,
void *priv)
{
/*
- * __blk_mq_update_nr_hw_queues() updates nr_hw_queues and queue_hw_ctx
+ * __blk_mq_update_nr_hw_queues() updates nr_hw_queues and hctx_table
* while the queue is frozen. So we can use q_usage_counter to avoid
* racing with it.
*/