From: Christoph Hellwig <hch@lst.de>
Date: Thu, 17 Feb 2022 07:52:31 +0000 (+0100)
Subject: block: fix surprise removal for drivers calling blk_set_queue_dying
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e65450a12cf4f3773b2607e305807f917e0bf239;p=linux.git

block: fix surprise removal for drivers calling blk_set_queue_dying

commit 7a5428dcb7902700b830e912feee4e845df7c019 upstream.

Various block drivers call blk_set_queue_dying to mark a disk as dead due
to surprise removal events, but since commit 8e141f9eb803 that doesn't
work given that the GD_DEAD flag needs to be set to stop I/O.

Replace the driver calls to blk_set_queue_dying with a new (and properly
documented) blk_mark_disk_dead API, and fold blk_set_queue_dying into the
only remaining caller.

Fixes: 8e141f9eb803 ("block: drain file system I/O on del_gendisk")
Reported-by: Markus Blöchl <markus.bloechl@ipetronik.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Link: https://lore.kernel.org/r/20220217075231.1140-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/block/blk-core.c b/block/blk-core.c
index d42a0f3ff7361..42ac3a985c2d7 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -350,13 +350,6 @@ void blk_queue_start_drain(struct request_queue *q)
 	wake_up_all(&q->mq_freeze_wq);
 }
 
-void blk_set_queue_dying(struct request_queue *q)
-{
-	blk_queue_flag_set(QUEUE_FLAG_DYING, q);
-	blk_queue_start_drain(q);
-}
-EXPORT_SYMBOL_GPL(blk_set_queue_dying);
-
 /**
  * blk_cleanup_queue - shutdown a request queue
  * @q: request queue to shutdown
@@ -374,7 +367,8 @@ void blk_cleanup_queue(struct request_queue *q)
 	WARN_ON_ONCE(blk_queue_registered(q));
 
 	/* mark @q DYING, no new request or merges will be allowed afterwards */
-	blk_set_queue_dying(q);
+	blk_queue_flag_set(QUEUE_FLAG_DYING, q);
+	blk_queue_start_drain(q);
 
 	blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
 	blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
diff --git a/block/genhd.c b/block/genhd.c
index de789d1a1e3d2..2dcedbe4ef046 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -544,6 +544,20 @@ out_free_ext_minor:
 }
 EXPORT_SYMBOL(device_add_disk);
 
+/**
+ * blk_mark_disk_dead - mark a disk as dead
+ * @disk: disk to mark as dead
+ *
+ * Mark as disk as dead (e.g. surprise removed) and don't accept any new I/O
+ * to this disk.
+ */
+void blk_mark_disk_dead(struct gendisk *disk)
+{
+	set_bit(GD_DEAD, &disk->state);
+	blk_queue_start_drain(disk->queue);
+}
+EXPORT_SYMBOL_GPL(blk_mark_disk_dead);
+
 /**
  * del_gendisk - remove the gendisk
  * @disk: the struct gendisk to remove
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 901855717cb53..ba61e72741eab 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -4112,7 +4112,7 @@ static void mtip_pci_remove(struct pci_dev *pdev)
 			"Completion workers still active!\n");
 	}
 
-	blk_set_queue_dying(dd->queue);
+	blk_mark_disk_dead(dd->disk);
 	set_bit(MTIP_DDF_REMOVE_PENDING_BIT, &dd->dd_flag);
 
 	/* Clean up the block layer. */
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index e65c9d706f6fb..c4a52f33604dc 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -7182,7 +7182,7 @@ static ssize_t do_rbd_remove(struct bus_type *bus,
 		 * IO to complete/fail.
 		 */
 		blk_mq_freeze_queue(rbd_dev->disk->queue);
-		blk_set_queue_dying(rbd_dev->disk->queue);
+		blk_mark_disk_dead(rbd_dev->disk);
 	}
 
 	del_gendisk(rbd_dev->disk);
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 4dbb71230d6e7..3efd341959832 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2128,7 +2128,7 @@ static void blkfront_closing(struct blkfront_info *info)
 
 	/* No more blkif_request(). */
 	blk_mq_stop_hw_queues(info->rq);
-	blk_set_queue_dying(info->rq);
+	blk_mark_disk_dead(info->gd);
 	set_capacity(info->gd, 0);
 
 	for_each_rinfo(info, rinfo, i) {
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index b75ff6b2b9525..5f33700d12473 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2156,7 +2156,7 @@ static void __dm_destroy(struct mapped_device *md, bool wait)
 	set_bit(DMF_FREEING, &md->flags);
 	spin_unlock(&_minor_lock);
 
-	blk_set_queue_dying(md->queue);
+	blk_mark_disk_dead(md->disk);
 
 	/*
 	 * Take suspend_lock so that presuspend and postsuspend methods
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 8aa92ebb8b7c1..a480e1af48e8e 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -131,7 +131,7 @@ static void nvme_set_queue_dying(struct nvme_ns *ns)
 	if (test_and_set_bit(NVME_NS_DEAD, &ns->flags))
 		return;
 
-	blk_set_queue_dying(ns->queue);
+	blk_mark_disk_dead(ns->disk);
 	blk_mq_unquiesce_queue(ns->queue);
 
 	set_capacity_and_notify(ns->disk, 0);
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 2f76969408b27..727520c397109 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -792,7 +792,7 @@ void nvme_mpath_remove_disk(struct nvme_ns_head *head)
 {
 	if (!head->disk)
 		return;
-	blk_set_queue_dying(head->disk->queue);
+	blk_mark_disk_dead(head->disk);
 	/* make sure all pending bios are cleaned up */
 	kblockd_schedule_work(&head->requeue_work);
 	flush_work(&head->requeue_work);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index be8e7a55d803c..413c0148c0ce5 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1184,7 +1184,8 @@ extern void blk_dump_rq_flags(struct request *, char *);
 
 bool __must_check blk_get_queue(struct request_queue *);
 extern void blk_put_queue(struct request_queue *);
-extern void blk_set_queue_dying(struct request_queue *);
+
+void blk_mark_disk_dead(struct gendisk *disk);
 
 #ifdef CONFIG_BLOCK
 /*