Re: [PATCH v4] scsi: target: tcmu: Fix possible data corruption

[Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>]

hi,

> Hi,
>
> just some remarks regarding the new comment.
>
> Bodo
>
> On 17.04.22 07:26, Xiaoguang Wang wrote:
>
> ... snip ...
>
>>   static const struct vm_operations_struct tcmu_vm_ops = {
>> @@ -3205,12 +3228,19 @@ static void find_free_blocks(void)
>>               udev->dbi_max = block;
>>           }
>>   +        /*
>> +         * Release the block pages.
>> +         * Also note that since tcmu_vma_fault() gets one extra page
>> +         * refcount, tcmu_blocks_release() won't free pages if pages
>> +         * are in page fault procedure, which means it's safe to
>
> s/in page fault procedure/mapped/
>
>> +         * call tcmu_blocks_release() before unmap_mapping_range().
>
> "... before unmap_mapping_range(), which drops the refcount of pages it
> unmaps and thus releases those pages."
>
> Please feel free to find an even better wording.
Yours seems better, just apply your suggestions.
I'm not a native english speaker :)

Regards,
Xiaoguang Wang
>
>> +         */
>> +        pages_freed = tcmu_blocks_release(udev, start, end - 1);
>> +
>>           /* Here will truncate the data area from off */
>>           off = udev->data_off + (loff_t)start * udev->data_blk_size;
>>           unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
>>   -        /* Release the block pages */
>> -        pages_freed = tcmu_blocks_release(udev, start, end - 1);
>>           mutex_unlock(&udev->cmdr_lock);
>>             total_pages_freed += pages_freed;