[PATCH v3] erofs: support STATX_DIOALIGN

[Hongbo Li]

On 2024/7/18 16:35, Gao Xiang wrote:
> 
> 
> On 2024/7/18 16:32, Gao Xiang wrote:
>> From: Hongbo Li via Linux-erofs <linux-erofs at lists.ozlabs.org>
> 
> Also I will fix the email address issue
> (Hongbo Li <lihongbo22 at huawei.com>) when applying too.
> 
>>
>> Add support for STATX_DIOALIGN to erofs, so that direct I/O
>> alignment restrictions are exposed to userspace in a generic
>> way.
>>
>> [Before]
>> ```
>> ./statx_test /mnt/erofs/testfile
>> statx(/mnt/erofs/testfile) = 0
>> dio mem align:0
>> dio offset align:0
>> ```
>>
>> [After]
>> ```
>> ./statx_test /mnt/erofs/testfile
>> statx(/mnt/erofs/testfile) = 0
>> dio mem align:512
>> dio offset align:512
>> ```
>>
>> Signed-off-by: Hongbo Li <lihongbo22 at huawei.com>
>> Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
>> ---
>> Hi Hongbo,
>>
>> I tidy up the patch a bit according to the current codebase,
>> I will apply this later for this cycle.
it's ok, and thank you!

Thanks,
Hongbo
>>
>> Also r-v-bs are always welcome...
>>
>> Thanks,
>> Gao Xiang
>>
>>   fs/erofs/inode.c | 19 +++++++++++++++++--
>>   1 file changed, 17 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
>> index 5f6439a63af7..43c09aae2afc 100644
>> --- a/fs/erofs/inode.c
>> +++ b/fs/erofs/inode.c
>> @@ -334,14 +334,29 @@ int erofs_getattr(struct mnt_idmap *idmap, const 
>> struct path *path,
>>             unsigned int query_flags)
>>   {
>>       struct inode *const inode = d_inode(path->dentry);
>> +    bool compressed =
>> +        erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout);
>> -    if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
>> +    if (compressed)
>>           stat->attributes |= STATX_ATTR_COMPRESSED;
>> -
>>       stat->attributes |= STATX_ATTR_IMMUTABLE;
>>       stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
>>                     STATX_ATTR_IMMUTABLE);
>> +    /*
>> +     * Return the DIO alignment restrictions if requested.
>> +     *
>> +     * In EROFS, STATX_DIOALIGN is not supported in ondemand mode and
>> +     * compressed files, so in these cases we report no DIO support.
>> +     */
>> +    if ((request_mask & STATX_DIOALIGN) && S_ISREG(inode->i_mode)) {
>> +        stat->result_mask |= STATX_DIOALIGN;
>> +        if (!erofs_is_fscache_mode(inode->i_sb) && !compressed) {
>> +            stat->dio_mem_align =
>> +                bdev_logical_block_size(inode->i_sb->s_bdev);
>> +            stat->dio_offset_align = stat->dio_mem_align;
>> +        }
>> +    }
>>       generic_fillattr(idmap, request_mask, inode, stat);
>>       return 0;
>>   }