[PATCH 1/9] block: consolidate the shutdown logic in blk_mark_disk_dead and del_gendisk

Christoph Hellwig
2023-05-05T17:52:56Z

blk_mark_disk_dead does very similar work a a section of del_gendisk:

- set the GD_DEAD flag
- set the capacity to zero
- start a queue drain

but del_gendisk also sets QUEUE_FLAG_DYING on the queue if it is owned by
the disk, sets the capacity to zero before starting the drain, and both
with sending a uevent and kernel message for this fake capacity change.

Move the exact logic from the more heavily used del_gendisk into
blk_mark_disk_dead and then call blk_mark_disk_dead from del_gendisk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/genhd.c | 26 ++++++++++++--------------
1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 90c402771bb570..461999e9489937 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -583,13 +583,22 @@ EXPORT_SYMBOL(device_add_disk);
*/
void blk_mark_disk_dead(struct gendisk *disk)
{
+ /*
+ * Fail any new I/O.
+ */
set_bit(GD_DEAD, &disk->state);
- blk_queue_start_drain(disk->queue);
+ if (test_bit(GD_OWNS_QUEUE, &disk->state))
+ blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue);

/*
* Stop buffered writers from dirtying pages that can't be written out.
*/
- set_capacity_and_notify(disk, 0);
+ set_capacity(disk, 0);
+
+ /*
+ * Prevent new I/O from crossing bio_queue_enter().
+ */
+ blk_queue_start_drain(disk->queue);
}
EXPORT_SYMBOL_GPL(blk_mark_disk_dead);

@@ -632,18 +641,7 @@ void del_gendisk(struct gendisk *disk)
fsync_bdev(disk->part0);
__invalidate_device(disk->part0, true);

- /*
- * Fail any new I/O.
- */
- set_bit(GD_DEAD, &disk->state);
- if (test_bit(GD_OWNS_QUEUE, &disk->state))
- blk_queue_flag_set(QUEUE_FLAG_DYING, q);
- set_capacity(disk, 0);
-
- /*
- * Prevent new I/O from crossing bio_queue_enter().
- */
- blk_queue_start_drain(q);
+ blk_mark_disk_dead(disk);

if (!(disk->flags & GENHD_FL_HIDDEN)) {
sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
--
2.39.2