f2fs: put allocate_segment after refresh_sit_entry

SIT information should be updated before segment allocation, since SSR needs
latest valid block information. Current code does not update the old_blkaddr
info in sit_entry, so adjust the allocate_segment to its proper location. Commit
5e443818 ("f2fs: handle dirty segments inside
refresh_sit_entry") puts it into wrong location.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/segment.c

@@ -1759,14 +1759,15 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 
 	stat_inc_block_count(sbi, curseg);
 
-	if (!__has_curseg_space(sbi, type))
-		sit_i->s_ops->allocate_segment(sbi, type, false);
 	/*
 	 * SIT information should be updated before segment allocation,
 	 * since SSR needs latest valid block information.
 	 */
 	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
 
+	if (!__has_curseg_space(sbi, type))
+		sit_i->s_ops->allocate_segment(sbi, type, false);
+
 	mutex_unlock(&sit_i->sentry_lock);
 
 	if (page && IS_NODESEG(type))