On Fri, Mar 22, 2019 at 10:48:18PM +0800, Yufen Yu wrote: > We convert 'active_queues' from atomic_t to newly provied > refcount_t type and API, which can prevent accidental counter > overflows and underflows.
There is no initialization using refcount_set(), which leads me to believe we're 0 initialized and then it's broken again. > Signed-off-by: Yufen Yu <[email protected]> > --- > block/blk-mq-debugfs.c | 2 +- > block/blk-mq-tag.c | 6 +++--- > block/blk-mq-tag.h | 2 +- > 3 files changed, 5 insertions(+), 5 deletions(-) > > diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c > index 81536b7201be..48f0cc2c90ba 100644 > --- a/block/blk-mq-debugfs.c > +++ b/block/blk-mq-debugfs.c > @@ -473,7 +473,7 @@ static void blk_mq_debugfs_tags_show(struct seq_file *m, > seq_printf(m, "nr_tags=%u\n", tags->nr_tags); > seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags); > seq_printf(m, "active_queues=%d\n", > - atomic_read(&tags->active_queues)); > + refcount_read(&tags->active_queues)); > > seq_puts(m, "\nbitmap_tags:\n"); > sbitmap_queue_show(&tags->bitmap_tags, m); > diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c > index 3fcb15fa6398..1d713f221bf7 100644 > --- a/block/blk-mq-tag.c > +++ b/block/blk-mq-tag.c > @@ -31,7 +31,7 @@ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) > { > if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) && > !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) > - atomic_inc(&hctx->tags->active_queues); > + refcount_inc(&hctx->tags->active_queues); > > return true; > } > @@ -57,7 +57,7 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) > if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) > return; > > - atomic_dec(&tags->active_queues); > + refcount_dec(&tags->active_queues); > > blk_mq_tag_wakeup_all(tags, false); > } > @@ -82,7 +82,7 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx > *hctx, > if (bt->sb.depth == 1) > return true; > > - users = atomic_read(&hctx->tags->active_queues); > + users = refcount_read(&hctx->tags->active_queues); > if (!users) > return true; > > diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h > index 61deab0b5a5a..e948b4833a2a 100644 > --- a/block/blk-mq-tag.h > +++ b/block/blk-mq-tag.h > @@ -11,7 +11,7 @@ struct blk_mq_tags { > unsigned int nr_tags; > unsigned int nr_reserved_tags; > > - atomic_t active_queues; > + refcount_t active_queues; > > struct sbitmap_queue bitmap_tags; > struct sbitmap_queue breserved_tags; > -- > 2.16.2.dirty >
