Re: [PATCH v2 2/2] staging: erofs: fix i_blocks calculation

From: Chao Yu
Date: Tue May 28 2019 - 05:48:42 EST


On 2019/5/28 14:57, Dan Carpenter wrote:
> On Tue, May 28, 2019 at 11:02:12AM +0800, Chao Yu wrote:
>> On 2019/5/28 10:36, Gao Xiang wrote:
>>> For compressed files, i_blocks should not be calculated
>>> by using i_size. i_u.compressed_blocks is used instead.
>>>
>>> In addition, i_blocks was miscalculated for non-compressed
>>> files previously, fix it as well.
>>>
>>> Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx>
>>> ---
>>> change log v2:
>>> - fix description in commit message
>>> - fix to 'inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK'
>>>
>>> Thanks,
>>> Gao Xiang
>>>
>>> drivers/staging/erofs/inode.c | 14 ++++++++++++--
>>> 1 file changed, 12 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
>>> index 8da144943ed6..6e67e018784e 100644
>>> --- a/drivers/staging/erofs/inode.c
>>> +++ b/drivers/staging/erofs/inode.c
>>> @@ -20,6 +20,7 @@ static int read_inode(struct inode *inode, void *data)
>>> struct erofs_vnode *vi = EROFS_V(inode);
>>> struct erofs_inode_v1 *v1 = data;
>>> const unsigned int advise = le16_to_cpu(v1->i_advise);
>>> + erofs_blk_t nblks = 0;
>>>
>>> vi->data_mapping_mode = __inode_data_mapping(advise);
>>>
>>> @@ -60,6 +61,10 @@ static int read_inode(struct inode *inode, void *data)
>>> le32_to_cpu(v2->i_ctime_nsec);
>>>
>>> inode->i_size = le64_to_cpu(v2->i_size);
>>> +
>>> + /* total blocks for compressed files */
>>> + if (vi->data_mapping_mode == EROFS_INODE_LAYOUT_COMPRESSION)
>>> + nblks = v2->i_u.compressed_blocks;
>>
>> Xiang,
>>
>> It needs to use le32_to_cpu(). ;)
>>
>
> I wonder it the kbuild bot is going to send an email about that...

0-day may do this a little later.

> Hopefully these sorts of bugs get detected with Sparse CF=-D__CHECK_ENDIAN__

Thanks, Dan, let's use this sparse flag more frequently to avoid such issue.

Thanks,

>
> regards,
> dan carpenter
>
> .
>