Re: [PATCH 1/2 v2] AOSP: erofs-utils: pass a parameter to write tail end in block list

[Gao Xiang <hsiangkao@linux.alibaba.com>]

On 2023/8/15 13:40, Yue Hu wrote:
> On Tue, 15 Aug 2023 12:59:56 +0800
> Gao Xiang <hsiangkao@linux.alibaba.com> wrote:
> 
>> On 2023/8/15 12:55, Yue Hu wrote:
>>> From: Yue Hu <huyue2@coolpad.com>
>>>
>>> We can determine whether the tail block is the first one or not during
>>> the writing process.  Therefore, instead of internally checking the
>>> block number for the tail block map, just simply pass the flag.
>>>
>>> Also, add the missing sbi argument to macro erofs_blknr.
>>
>> Could you submit a patch to fix this issue first?
> 
> ok, will do that.
> 
>>
>>>
>>> Signed-off-by: Yue Hu <huyue2@coolpad.com>
>>> ---
>>> v2: change commit message a bit
>>>
>>>    include/erofs/block_list.h | 4 ++--
>>>    lib/block_list.c           | 5 ++---
>>>    lib/inode.c                | 9 +++++++--
>>>    3 files changed, 11 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/include/erofs/block_list.h b/include/erofs/block_list.h
>>> index 78fab44..e0dced8 100644
>>> --- a/include/erofs/block_list.h
>>> +++ b/include/erofs/block_list.h
>>> @@ -19,7 +19,7 @@ void erofs_droid_blocklist_fclose(void);
>>>    void erofs_droid_blocklist_write(struct erofs_inode *inode,
>>>    				 erofs_blk_t blk_start, erofs_blk_t nblocks);
>>>    void erofs_droid_blocklist_write_tail_end(struct erofs_inode *inode,
>>> -					  erofs_blk_t blkaddr);
>>> +					  erofs_blk_t blkaddr, bool first_block);
>>
>> I still have no idea why we need this, could you describe the Android
>> block map details for discussion?
> 
> Android block map is just adding file blocks to a range.
> 
> So, the tail block should be needed in this range as well.
> I think one simple way is just appending the tail block address in it as below:
> 
> /`file_path` `block1_address`-`blockn_address` `tail_block_address`

why `tail_block_address` needs a seperate field?

> 
> or
> 
> /`file_path` `tail_block_address`   //only one block

how about recording the previous inode pointer as an internal global variable?
if it's not the same inode, trigger "\n" immediately.

and generate files as:
" `block1_address`-`blockn_address`"  for many blocks;
" `block1_address`" for a single block?

Thanks,
Gao Xiang