From: Christoph Hellwig <hch@lst.de>
Date: Thu, 9 Dec 2021 07:31:21 +0100
Subject: [PATCH] block: remove the nr_task field from struct io_context
Git-commit: 8a2ba1785c5803d59a63b6320ff54fd4a37a41ce
Patch-mainline: v5.17-rc1
References: jsc#PED-1183

Nothing ever looks at ->nr_tasks, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20211209063131.18537-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 block/blk-ioc.c           | 3 ---
 include/linux/iocontext.h | 1 -
 2 files changed, 4 deletions(-)

diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 536fb496ad76..96336c2134ef 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -207,7 +207,6 @@ void exit_io_context(struct task_struct *task)
 	task->io_context = NULL;
 	task_unlock(task);
 
-	atomic_dec(&ioc->nr_tasks);
 	put_io_context_active(ioc);
 }
 
@@ -259,7 +258,6 @@ static struct io_context *alloc_io_context(gfp_t gfp_flags, int node)
 		return NULL;
 
 	atomic_long_set(&ioc->refcount, 1);
-	atomic_set(&ioc->nr_tasks, 1);
 	atomic_set(&ioc->active_ref, 1);
 	spin_lock_init(&ioc->lock);
 	INIT_RADIX_TREE(&ioc->icq_tree, GFP_ATOMIC);
@@ -339,7 +337,6 @@ int __copy_io(unsigned long clone_flags, struct task_struct *tsk)
 	if (clone_flags & CLONE_IO) {
 		atomic_long_inc(&ioc->refcount);
 		atomic_inc(&ioc->active_ref);
-		atomic_inc(&ioc->nr_tasks);
 		tsk->io_context = ioc;
 	} else if (ioprio_valid(ioc->ioprio)) {
 		tsk->io_context = alloc_io_context(GFP_KERNEL, NUMA_NO_NODE);
diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h
index c1229fbd6691..82c7f4f5f4f5 100644
--- a/include/linux/iocontext.h
+++ b/include/linux/iocontext.h
@@ -99,7 +99,6 @@ struct io_cq {
 struct io_context {
 	atomic_long_t refcount;
 	atomic_t active_ref;
-	atomic_t nr_tasks;
 
 	/* all the fields below are protected by this lock */
 	spinlock_t lock;
-- 
2.35.3