From cce1325247b9faafc520c5789fe60feef1fd7092 Mon Sep 17 00:00:00 2001
From: Chao Yu <yuchao0@huawei.com>
Date: Thu, 29 Jun 2017 23:17:45 +0800
Subject: f2fs: stop gc/discard thread in prior during umount

This patch resolves kernel panic for xfstests/081, caused by recent f2fs_bug_on

 f2fs: add f2fs_bug_on in __remove_discard_cmd

For fixing, we will stop gc/discard thread in prior in ->kill_sb in order to
avoid referring and releasing race among them.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/segment.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

(limited to 'fs/f2fs/segment.c')

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 7637033ef87b..6eaa98ea8ec6 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1065,6 +1065,18 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
 		__wait_one_discard_bio(sbi, dc);
 }
 
+void stop_discard_thread(struct f2fs_sb_info *sbi)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+
+	if (dcc && dcc->f2fs_issue_discard) {
+		struct task_struct *discard_thread = dcc->f2fs_issue_discard;
+
+		dcc->f2fs_issue_discard = NULL;
+		kthread_stop(discard_thread);
+	}
+}
+
 /* This comes from f2fs_put_super */
 void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
 {
@@ -1422,12 +1434,7 @@ static void destroy_discard_cmd_control(struct f2fs_sb_info *sbi)
 	if (!dcc)
 		return;
 
-	if (dcc->f2fs_issue_discard) {
-		struct task_struct *discard_thread = dcc->f2fs_issue_discard;
-
-		dcc->f2fs_issue_discard = NULL;
-		kthread_stop(discard_thread);
-	}
+	stop_discard_thread(sbi);
 
 	kfree(dcc);
 	SM_I(sbi)->dcc_info = NULL;
-- 
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