> 下面是被转发的邮件：
>
> 发件人: linux-block+owner@xxxxxxxxxxxxxxx
> 主题: HTML message rejected: Re: [PATCH] loop: move vfs_fsync() out of loop_update_dio()
> 日期: 2025年3月19日 GMT+8 09:29:24
> 收件人: huk23@xxxxxxxxxxxxxx
>
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> For your reference, the rejected message follows below.
>
> 发件人: Kun Hu <huk23@xxxxxxxxxxxxxx>
> 主题: 回复：[PATCH] loop: move vfs_fsync() out of loop_update_dio()
> 日期: 2025年3月19日 GMT+8 09:28:24
> 收件人: Ming Lei <ming.lei@xxxxxxxxxx>
> 抄送: linux-block <linux-block@xxxxxxxxxxxxxxx>, Christoph Hellwig <hch@xxxxxxxxxxxxx>, "jjtan24@xxxxxxxxxxxxxx" <jjtan24@xxxxxxxxxxxxxx>
>
>
>
>
>> 2025年3月18日 09:07，Ming Lei <ming.lei@xxxxxxxxxx> 写道：
>>
>> On Mon, Mar 17, 2025 at 04:52:16PM +0800, 胡焜 wrote:
>>>> drivers/block/loop.c | 12 ++++++------
>>>> 1 file changed, 6 insertions(+), 6 deletions(-)
>>>
>>>> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
>>>> index 1ec7417c7f00..be7e20064427 100644
>>>> --- a/drivers/block/loop.c
>>>> +++ b/drivers/block/loop.c
>>>> @@ -205,8 +205,6 @@ static bool lo_can_use_dio(struct loop_device *lo)
>>>> */
>>>> static inline void loop_update_dio(struct loop_device *lo)
>>>> {
>>>> - bool dio_in_use = lo->lo_flags & LO_FLAGS_DIRECT_IO;
>>>> -
>>>> lockdep_assert_held(&lo->lo_mutex);
>>>> WARN_ON_ONCE(lo->lo_state == Lo_bound &&
>>>> lo->lo_queue->mq_freeze_depth == 0);
>>>> @@ -215,10 +213,6 @@ static inline void loop_update_dio(struct loop_device *lo)
>>>> lo->lo_flags |= LO_FLAGS_DIRECT_IO;
>>>> if ((lo->lo_flags & LO_FLAGS_DIRECT_IO) && !lo_can_use_dio(lo))
>>>> lo->lo_flags &= ~LO_FLAGS_DIRECT_IO;
>>>> -
>>>> - /* flush dirty pages before starting to issue direct I/O */
>>>> - if ((lo->lo_flags & LO_FLAGS_DIRECT_IO) && !dio_in_use)
>>>> - vfs_fsync(lo->lo_backing_file, 0);
>>>> }
>>>>
>>>> /**
>>>> @@ -621,6 +615,9 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
>>>> if (get_loop_size(lo, file) != get_loop_size(lo, old_file))
>>>> goto out_err;
>>>
>>>> + /* may work in dio, so flush page cache for avoiding race */
>>>> + vfs_fsync(file, 0);
>>>> +
>>>> /* and ... switch */
>>>> disk_force_media_change(lo->lo_disk);
>>>> blk_mq_freeze_queue(lo->lo_queue);
>>>> @@ -1098,6 +1095,9 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode,
>>>> if (error)
>>>> goto out_unlock;
>>>
>>>> + /* may work in dio, so flush page cache for avoiding race */
>>>> + vfs_fsync(file, 0);
>>>> +
>>>> loop_update_dio(lo);
>>>> loop_sysfs_init(lo);
>>>>
>>>> --
>>>> 2.44.0
>>>
>>>
>>> Hello Ming,
>>>
>>> I would like to double check that this fix doesn't seem to have been merged into the main thread, will this version still be merged into mainline kernel tree?
>>
>> The V2 has been sent out after updating comment, please verify if it fixes your issue:
>>
>> https://lore.kernel.org/linux-block/20250318010318.3861682-1-ming.lei@xxxxxxxxxx/
>>
>> If yes, feel free to provide one tested-by for moving on.
>>
>>
>> Thanks,
>> Ming
>
>
>
> Thank you very much, this crash has not triggered again after several rounds of testing!
>
> Best,
> Kun
>
