Hello,
Draining FS I/O on del_gendisk() is added for just avoiding to refer to
recently added q->disk in IO path, and it isn't actually needed.
Now we can move killing disk into queue's release handler, see patch 1,
so no need to drain FS I/O on del_gendisk().
Draining FS I/O on del_gendisk() isn't reliable, see the following
cases, so revert this behavior.
1) queue freezing can't drain FS I/O for bio based driver
2) it isn't easy to move elevator/cgroup/throttle shutdown during
del_gendisk, and q->disk can still be referred in these code paths
3) the added flag of GD_DEAD may not be observed reliably in
__bio_queue_enter() because queue freezing might not imply rcu grace
period.
Ming Lei (3):
block: move freeing disk into queue's release handler
block: revert aec89dc5d421 block: keep q_usage_counter in atomic mode
after del_gendisk
block: revert 8e141f9eb803 block: drain file system I/O on del_gendisk
block/blk-core.c | 24 ++++++++++++------------
block/blk-mq.c | 9 +--------
block/blk-sysfs.c | 13 +++++++++++++
block/blk.h | 2 --
block/genhd.c | 31 +++++--------------------------
include/linux/genhd.h | 1 -
6 files changed, 31 insertions(+), 49 deletions(-)
--
2.31.1
