[PATCH 6/9] block: add a mark_dead holder operation

Christoph Hellwig
2023-05-05T17:53:17Z

Add a mark_dead method to blk_holder_ops that is called from blk_mark_disk_dead
to notify the holder that the block device it is using has been marked dead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/genhd.c | 24 ++++++++++++++++++++++++
include/linux/blkdev.h | 1 +
2 files changed, 25 insertions(+)

diff --git a/block/genhd.c b/block/genhd.c
index d1c673b967c254..af97a4ef1e926c 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -575,6 +575,28 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
}
EXPORT_SYMBOL(device_add_disk);

+static void blk_report_disk_dead(struct gendisk *disk)
+{
+ struct block_device *bdev;
+ unsigned long idx;
+
+ rcu_read_lock();
+ xa_for_each(&disk->part_tbl, idx, bdev) {
+ if (!kobject_get_unless_zero(&bdev->bd_device.kobj))
+ continue;
+ rcu_read_unlock();
+
+ mutex_lock(&bdev->bd_holder_lock);
+ if (bdev->bd_holder_ops && bdev->bd_holder_ops->mark_dead)
+ bdev->bd_holder_ops->mark_dead(bdev);
+ mutex_unlock(&bdev->bd_holder_lock);
+
+ put_device(&bdev->bd_device);
+ rcu_read_lock();
+ }
+ rcu_read_unlock();
+}
+
/**
* blk_mark_disk_dead - mark a disk as dead
* @disk: disk to mark as dead
@@ -602,6 +624,8 @@ void blk_mark_disk_dead(struct gendisk *disk)
* Prevent new I/O from crossing bio_queue_enter().
*/
blk_queue_start_drain(disk->queue);
+
+ blk_report_disk_dead(disk);
}
EXPORT_SYMBOL_GPL(blk_mark_disk_dead);

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3f41f8c9b103cf..9706bec2be16a5 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1469,6 +1469,7 @@ void blkdev_show(struct seq_file *seqf, off_t offset);
#endif

struct blk_holder_ops {
+ void (*mark_dead)(struct block_device *bdev);
};

struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder,
--
2.39.2