f2fs: fix incorrect multidevice info in trace_f2fs_map_blocks()

commit eb2ca3c upstream.

When f2fs_map_blocks()->f2fs_map_blocks_cached() hits the read extent
cache, map->m_multidev_dio is not updated, which leads to incorrect
multidevice information being reported by trace_f2fs_map_blocks().

This patch updates map->m_multidev_dio in f2fs_map_blocks_cached() when
the read extent cache is hit.

Cc: stable@kernel.org
Fixes: 0094e98 ("f2fs: factor a f2fs_map_blocks_cached helper")
Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Yongpeng Yang

fs/f2fs/data.c

@@ -1509,7 +1509,8 @@ static bool f2fs_map_blocks_cached(struct inode *inode,
 		f2fs_wait_on_block_writeback_range(inode,
 					map->m_pblk, map->m_len);
 
-	if (f2fs_allow_multi_device_dio(sbi, flag)) {
+	map->m_multidev_dio = f2fs_allow_multi_device_dio(sbi, flag);
+	if (map->m_multidev_dio) {
 		int bidx = f2fs_target_device_index(sbi, map->m_pblk);
 		struct f2fs_dev_info *dev = &sbi->devs[bidx];