Re: [PATCH v2] ext4: avoid eh_entries overflow before insert extent_idx

[Coly Li <colyli@gmail.com>]

On 2011年06月23日 17:00, Yongqiang Yang Wrote:
> On Thu, Jun 23, 2011 at 4:47 PM, Robin Dong <hao.bigrat@gmail.com> wrote:
>> If eh_entries is equal to (or greater than) eh_max, the operation of
>> inserting new extent_idx will make number of entries overflow.
>> So check eh_entries before inserting the new extent_idx.
>>
>> Signed-off-by: Robin Dong <sanbai@taobao.com>
>> ---
>> �fs/ext4/extents.c | � 18 ++++++++++--------
>> �1 files changed, 10 insertions(+), 8 deletions(-)
>>
>> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
>> index eb63c7b..792e77e 100644
>> --- a/fs/ext4/extents.c
>> +++ b/fs/ext4/extents.c
[snip]

>> � � � �if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
> condition ix > EXT_LAST_INDEX(curp->p_hdr) can not be true.  Right?
> May be we can remove this if-statement in this patch.
> 
> Yongqiang.
[snip]

Good suggestion. But I suggest us to remove it a little bit later. When we do meta data checksum, the last index/extent
record might be used for checksum, the above checking might still be helpful for bug probing.

Thanks.

Coly
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