diff options
Diffstat (limited to 'block/blk-mq-tag.c')
| -rw-r--r-- | block/blk-mq-tag.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 09b2ee6694fb..94e1ed667b6e 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -23,6 +23,9 @@ bool blk_mq_has_free_tags(struct blk_mq_tags *tags) /* * If a previously inactive queue goes active, bump the active user count. + * We need to do this before try to allocate driver tag, then even if fail + * to get tag when first time, the other shared-tag users could reserve + * budget for it. */ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) { @@ -271,7 +274,7 @@ static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) * test and set the bit before assining ->rqs[]. */ rq = tags->rqs[bitnr]; - if (rq && blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT) + if (rq && blk_mq_request_started(rq)) iter_data->fn(rq, iter_data->data, reserved); return true; @@ -317,6 +320,18 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, struct blk_mq_hw_ctx *hctx; int i; + /* + * __blk_mq_update_nr_hw_queues will update the nr_hw_queues and + * queue_hw_ctx after freeze the queue. So we could use q_usage_counter + * to avoid race with it. __blk_mq_update_nr_hw_queues will users + * synchronize_rcu to ensure all of the users go out of the critical + * section below and see zeroed q_usage_counter. + */ + rcu_read_lock(); + if (percpu_ref_is_zero(&q->q_usage_counter)) { + rcu_read_unlock(); + return; + } queue_for_each_hw_ctx(q, hctx, i) { struct blk_mq_tags *tags = hctx->tags; @@ -332,7 +347,7 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, bt_for_each(hctx, &tags->breserved_tags, fn, priv, true); bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false); } - + rcu_read_unlock(); } static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, @@ -399,8 +414,6 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, if (tdepth <= tags->nr_reserved_tags) return -EINVAL; - tdepth -= tags->nr_reserved_tags; - /* * If we are allowed to grow beyond the original size, allocate * a new set of tags before freeing the old one. @@ -420,7 +433,8 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, if (tdepth > 16 * BLKDEV_MAX_RQ) return -EINVAL; - new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, 0); + new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, + tags->nr_reserved_tags); if (!new) return -ENOMEM; ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth); @@ -437,7 +451,8 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, * Don't need (or can't) update reserved tags here, they * remain static and should never need resizing. */ - sbitmap_queue_resize(&tags->bitmap_tags, tdepth); + sbitmap_queue_resize(&tags->bitmap_tags, + tdepth - tags->nr_reserved_tags); } return 0; |