Re: [PATCH v2 0/7] exfat: fix valid_size update races

[Chi Zhiling <chizhiling@163.com>]

On 10/13/2026 12:04 PM, Namjae Jeon wrote:
> On Tue, Oct 13, 2026 at 12:39 PM Chi Zhiling <chizhiling@163.com> wrote:
>>
>> From: Chi Zhiling <chizhiling@kylinos.cn>
> Hi Chi,

Hi Namjae,

>>
>> exFAT uses valid_size (ValidDataLength) as the on-disk boundary of
>> initialised data, but the current code advances it too late or without
>> proper serialisation.  As a result, buffered writes can silently lose
>> data reclaimed before valid_size covers it, page faults and direct I/O
>> can race with writes, and a failed direct write still grows the file
>> on disk.
>>
>> This series advances valid_size under the folio lock for buffered
>> writes, revalidates cached iomaps, drops i_rwsem from
>> exfat_page_mkwrite(), and publishes i_size/valid_size only on
>> successful direct I/O completion.
>>
>> V1: https://lore.kernel.org/exfat/59056131-e3bd-4003-8c30-0a356cf0bd82@163.com/
>> Link: https://lore.kernel.org/exfat/10029d6f-13cc-4d17-a2f9-b093a8339dde/T/#t
>>
>> Chi Zhiling (7):
>>    exfat: advance valid_size under the folio lock for buffered writes
>>    exfat: advance valid_size while zeroing new ranges
>>    exfat: validate cached iomaps during buffered writes
>>    exfat: drop i_rwsem from exfat_page_mkwrite
>>    exfat: do not re-zero the valid range in exfat_page_mkwrite
>>    exfat: complete direct writes synchronously when they update metadata
>>    exfat: publish i_size and valid_size on direct I/O completion
> Can you add fixes tags to the patches ?

Sure, I'll add Fixes tag in the next version.