f2fs: add sanity check on ei.len in __update_extent_tree_range()

Add a sanity check in __update_extent_tree_range() to detect any
zero-sized extent update.

Signed-off-by: wangzijie <[email protected]>
Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>

Author: chaseyu

fs/f2fs/extent_cache.c

@@ -670,6 +670,15 @@ static void __update_extent_tree_range(struct inode *inode,
 	if (!et)
 		return;
 
+	if (unlikely(len == 0)) {
+		f2fs_err_ratelimited(sbi, "%s: extent len is zero, type: %d, "
+			"extent [%u, %u, %u], age [%llu, %llu]",
+			__func__, type, tei->fofs, tei->blk, tei->len,
+			tei->age, tei->last_blocks);
+		f2fs_bug_on(sbi, 1);
+		return;
+	}
+
 	if (type == EX_READ)
 		trace_f2fs_update_read_extent_tree_range(inode, fofs, len,
 						tei->blk, 0);