f2fs: check pinfile in gc_data_segment() in advance

In order to skip migrating section which contains data of pinned
file in advance.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/gc.c

@@ -1480,6 +1480,13 @@ next_step:
 					special_file(inode->i_mode))
 				continue;
 
+			if (is_inode_flag_set(inode, FI_PIN_FILE) &&
+							gc_type == FG_GC) {
+				f2fs_pin_file_control(inode, true);
+				iput(inode);
+				return submitted;
+			}
+
 			if (!f2fs_down_write_trylock(
 				&F2FS_I(inode)->i_gc_rwsem[WRITE])) {
 				iput(inode);