Unverified Commit 9ea5cbb2 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!9856 btrfs: fix memory ordering between normal and ordered work functions 

Merge Pull Request from: @ci-robot 
 
PR sync from: Yifan Qiao <qiaoyifan4@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/W3NCP7R2VX6ION5LSX3RIGHW2APPNFI7/ 
 
https://gitee.com/src-openeuler/kernel/issues/I9FNFN 
 
Link:https://gitee.com/openeuler/kernel/pulls/9856

 

Reviewed-by: default avatarzhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: default avatarLiu YongQiang <liuyongqiang13@huawei.com>
Signed-off-by: default avatarZhang Changzhong <zhangchangzhong@huawei.com>
parents 07c988f0 5d1d5942

fs/btrfs/async-thread.c

+14 −0
Original line number Diff line number Diff line
@@ -270,6 +270,13 @@ static void run_ordered_work(struct __btrfs_workqueue *wq, 
				  ordered_list);

		if (!test_bit(WORK_DONE_BIT, &work->flags))

			break;

		/*

		 * Orders all subsequent loads after reading WORK_DONE_BIT,

		 * paired with the smp_mb__before_atomic in btrfs_work_helper

		 * this guarantees that the ordered function will see all

		 * updates from ordinary work function.

		 */

		smp_rmb();



		/*

		 * we are going to call the ordered done function, but
@@ -355,6 +362,13 @@ static void normal_work_helper(struct btrfs_work *work) 
	thresh_exec_hook(wq);

	work->func(work);

	if (need_order) {

		/*

		 * Ensures all memory accesses done in the work function are

		 * ordered before setting the WORK_DONE_BIT. Ensuring the thread

		 * which is going to executed the ordered work sees them.

		 * Pairs with the smp_rmb in run_ordered_work.

		 */

		smp_mb__before_atomic();

		set_bit(WORK_DONE_BIT, &work->flags);

		run_ordered_work(wq, work);

	}