[PATCH 4/4] block: keep q_usage_counter in atomic mode after del_gendisk
flat view
STALE1840d
From: Christoph Hellwig <hch@lst.de>
Date: 2021-09-22 17:33:48
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
Don't switch back to percpu mode to avoid the double RCU grace period when tearing down SCSI devices. After removing the disk only passthrough commands can be send anyway. Suggested-by: Ming Lei <redacted> Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/blk-mq.c | 9 ++++++++- block/blk.h | 1 + block/genhd.c | 3 ++- 3 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 108a352051be5..bc026372de439 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -188,9 +188,11 @@ void blk_mq_freeze_queue(struct request_queue *q) } EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); -void blk_mq_unfreeze_queue(struct request_queue *q) +void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic) { mutex_lock(&q->mq_freeze_lock); + if (force_atomic) + q->q_usage_counter.data->force_atomic = true; q->mq_freeze_depth--; WARN_ON_ONCE(q->mq_freeze_depth < 0); if (!q->mq_freeze_depth) {
@@ -199,6 +201,11 @@ void blk_mq_unfreeze_queue(struct request_queue *q) } mutex_unlock(&q->mq_freeze_lock); } + +void blk_mq_unfreeze_queue(struct request_queue *q) +{ + __blk_mq_unfreeze_queue(q, false); +} EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); /*
diff --git a/block/blk.h b/block/blk.h
index e2ed2257709ae..6c3c00a8fe19d 100644
--- a/block/blk.h
+++ b/block/blk.h@@ -51,6 +51,7 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, void blk_free_flush_queue(struct blk_flush_queue *q); void blk_freeze_queue(struct request_queue *q); +void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic); void blk_queue_start_drain(struct request_queue *q); #define BIO_INLINE_VECS 4
diff --git a/block/genhd.c b/block/genhd.c
index b3c33495d7208..edd013a820879 100644
--- a/block/genhd.c
+++ b/block/genhd.c@@ -596,7 +596,8 @@ void del_gendisk(struct gendisk *disk) /* * Allow using passthrough request again after the queue is torn down. */ - blk_mq_unfreeze_queue(q); + blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q); + __blk_mq_unfreeze_queue(q, true); if (!(disk->flags & GENHD_FL_HIDDEN)) { sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
--
2.30.2