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

[Chao Yu]

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

Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
 fs/f2fs/extent_cache.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 199c1e7a83ef..9544323767be 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -664,6 +664,15 @@ static void __update_extent_tree_range(struct inode *inode,
 	if (!et)
 		return;

+	if (unlikely(len == 0)) {
+		f2fs_bug_on(sbi, 1);
+		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);
+		return;
+	}
+
 	if (type == EX_READ)
 		trace_f2fs_update_read_extent_tree_range(inode, fofs, len,
 						tei->blk, 0);
-- 
2.49.0


> 
> 
> 
>>>
>>>
>>>>>
>>>>> Signed-off-by: wangzijie <wangzijie1@xxxxxxxxx>
>>>>> ---
>>>>>  fs/f2fs/extent_cache.c | 1 +
>>>>>  1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
>>>>> index 199c1e7a8..6ed6f3d1d 100644
>>>>> --- a/fs/f2fs/extent_cache.c
>>>>> +++ b/fs/f2fs/extent_cache.c
>>>>> @@ -605,6 +605,7 @@ static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
>>>>>  			leftmost = false;
>>>>>  		} else {
>>>>>  			f2fs_bug_on(sbi, 1);
>>>>> +			return NULL;
>>>>>  		}
>>>>>  	}
>>>>>  
>>>>> -- 
>>>>> 2.25.1
>