Re: [PATCH v2 4/5] ntfs: write unlinked file attributes before dropping their cache

[liubaolin <liubaolin12138@163.com>]

在 2026/11/4 17:06, Namjae Jeon 写道:
>> @@ -4052,6 +4052,14 @@ s64 ntfs_inode_attr_pwrite(struct inode *vi, s64 pos, s64 count, u8 *buf, bool s
>>
>>          WARN_ON(!NInoAttr(ni));
>>
>> +       /*
>> +        * Attribute inodes of an unlinked file have no links either and are
>> +        * evicted at the final iput(). Do not leave their data in dirty pages
>> +        * that eviction would discard while the base file is still open.
>> +        */
>> +       if (!VFS_I(base_ni)->i_nlink && !ntfs_inode_is_named_stream(ni))
>> +               sync = true;
> This misses data dirtied by ntfs_attr_make_non_resident(). For
> example, with 1 KiB MFT records, create an O_TMPFILE, nearly fill
> its MFT record with a resident EA, then write 4 KiB to the file.
> Growing $DATA can force ntfs_resident_attr_resize() to convert
> SECURITY_DESCRIPTOR to nonresident form to make room. the conversion
> only dirties the folio. With patch 5, the subsequent
> iput(tvi) can evict the zero-link attribute inode and discard the SD
> contents before writeback. If the file is later linked with linkat(),
> it can retain invalid SD data after close. Please also ensure that the
> converted data is written back before dropping the last
> attribute-inode reference.
> 
> Thanks!

Hi Namjae,
    Thank you for the review. I will fix this issue and send v3 soon.

Thanks,
Baolin.