[PATCH 5.6 081/166] f2fs: fix to update f2fs_super_block fields under sb_lock

[Greg Kroah-Hartman]

From: Chao Yu <yuchao0@xxxxxxxxxx>

[ Upstream commit a4ba5dfc5c88e49bb03385abfdd28c5a0acfbb54 ]

Fields in struct f2fs_super_block should be updated under coverage
of sb_lock, fix to adjust update_sb_metadata() for that rule.

Fixes: 04f0b2eaa3b3 ("f2fs: ioctl for removing a range from F2FS")
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/f2fs/gc.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index db8725d473b52..9cff2502e3bc6 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1434,12 +1434,19 @@ static int free_segment_range(struct f2fs_sb_info *sbi, unsigned int start,
 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
 {
 	struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
-	int section_count = le32_to_cpu(raw_sb->section_count);
-	int segment_count = le32_to_cpu(raw_sb->segment_count);
-	int segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
-	long long block_count = le64_to_cpu(raw_sb->block_count);
+	int section_count;
+	int segment_count;
+	int segment_count_main;
+	long long block_count;
 	int segs = secs * sbi->segs_per_sec;
 
+	down_write(&sbi->sb_lock);
+
+	section_count = le32_to_cpu(raw_sb->section_count);
+	segment_count = le32_to_cpu(raw_sb->segment_count);
+	segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
+	block_count = le64_to_cpu(raw_sb->block_count);
+
 	raw_sb->section_count = cpu_to_le32(section_count + secs);
 	raw_sb->segment_count = cpu_to_le32(segment_count + segs);
 	raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
@@ -1453,6 +1460,8 @@ static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
 		raw_sb->devs[last_dev].total_segments =
 						cpu_to_le32(dev_segs + segs);
 	}
+
+	up_write(&sbi->sb_lock);
 }
 
 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
-- 
2.20.1