From: Christoph Hellwig <hch@lst.de>
Date: Thu, 27 Jan 2022 08:05:48 +0100
Subject: [PATCH] block: remove blk_needs_flush_plug
Git-commit: b1f866b013e6e5583f2f0bf4a61d13eddb9a1799
Patch-mainline: v5.18-rc1
References: jsc#PED-1183
blk_needs_flush_plug fails to account for the cb_list, which needs
flushing as well. Remove it and just check if there is a plug instead
of poking into the internals of the plug structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220127070549.1377856-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
fs/fs-writeback.c | 2 +-
include/linux/blkdev.h | 13 -------------
kernel/exit.c | 2 +-
kernel/sched/core.c | 2 +-
4 files changed, 3 insertions(+), 16 deletions(-)
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -2301,7 +2301,7 @@ void wakeup_flusher_threads(enum wb_reas
/*
* If we are expecting writeback progress we must submit plugged IO.
*/
- if (blk_needs_flush_plug(current))
+ if (current->plug)
blk_flush_plug(current->plug, true);
rcu_read_lock();
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1056,14 +1056,6 @@ extern void blk_finish_plug(struct blk_p
void blk_flush_plug(struct blk_plug *plug, bool from_schedule);
-static inline bool blk_needs_flush_plug(struct task_struct *tsk)
-{
- struct blk_plug *plug = tsk->plug;
-
- return plug &&
- (plug->mq_list || !list_empty(&plug->cb_list));
-}
-
int blkdev_issue_flush(struct block_device *bdev);
long nr_blockdev_pages(void);
#else /* CONFIG_BLOCK */
@@ -1087,11 +1079,6 @@ static inline void blk_flush_plug(struct
{
}
-static inline bool blk_needs_flush_plug(struct task_struct *tsk)
-{
- return false;
-}
-
static inline int blkdev_issue_flush(struct block_device *bdev)
{
return 0;
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -730,7 +730,7 @@ void __noreturn do_exit(long code)
struct task_struct *tsk = current;
int group_dead;
- WARN_ON(blk_needs_flush_plug(tsk));
+ WARN_ON(tsk->plug);
/*
* If do_dead is called because this processes oopsed, it's possible
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6158,7 +6158,7 @@ static inline void sched_submit_work(str
* If we are going to sleep and we have plugged IO queued,
* make sure to submit it to avoid deadlocks.
*/
- if (blk_needs_flush_plug(tsk))
+ if (tsk->plug)
blk_flush_plug(tsk->plug, true);
}