Re: [PATCH v4 3/3] xen/efi: Update error flow for read_file function

[Jan Beulich <jbeulich@xxxxxxxx>]

On 26.06.2025 15:41, Frediano Ziglio wrote:
> On Thu, Jun 26, 2025 at 2:31 PM Jan Beulich <jbeulich@xxxxxxxx> wrote:
>>
>> On 26.06.2025 15:10, Frediano Ziglio wrote:
>>> --- a/xen/common/efi/boot.c
>>> +++ b/xen/common/efi/boot.c
>>> @@ -792,6 +792,8 @@ static bool __init read_file(EFI_FILE_HANDLE 
>>> dir_handle, CHAR16 *name,
>>>
>>>      if ( !name )
>>>          PrintErrMesg(L"No filename", EFI_OUT_OF_RESOURCES);
>>> +
>>> +    what = L"Open";
>>>      if ( dir_handle )
>>>          ret = dir_handle->Open(dir_handle, &FileHandle, name,
>>>                                 EFI_FILE_MODE_READ, 0);
>>> @@ -800,54 +802,58 @@ static bool __init read_file(EFI_FILE_HANDLE 
>>> dir_handle, CHAR16 *name,
>>>      if ( file == &cfg && ret == EFI_NOT_FOUND )
>>>          return false;
>>>      if ( EFI_ERROR(ret) )
>>> -        what = L"Open";
>>> -    else
>>> -        ret = FileHandle->SetPosition(FileHandle, -1);
>>> +        goto fail;
>>> +
>>> +    what = L"Seek";
>>> +    ret = FileHandle->SetPosition(FileHandle, -1);
>>>      if ( EFI_ERROR(ret) )
>>> -        what = what ?: L"Seek";
>>> -    else
>>> -        ret = FileHandle->GetPosition(FileHandle, &size);
>>> +        goto fail;
>>> +
>>> +    what = L"Get size";
>>> +    ret = FileHandle->GetPosition(FileHandle, &size);
>>>      if ( EFI_ERROR(ret) )
>>> -        what = what ?: L"Get size";
>>> -    else
>>> -        ret = FileHandle->SetPosition(FileHandle, 0);
>>> +        goto fail;
>>> +
>>> +    what = L"Seek";
>>> +    ret = FileHandle->SetPosition(FileHandle, 0);
>>>      if ( EFI_ERROR(ret) )
>>> -        what = what ?: L"Seek";
>>> -    else
>>> -    {
>>> -        file->addr = min(1UL << (32 + PAGE_SHIFT),
>>> -                         HYPERVISOR_VIRT_END - DIRECTMAP_VIRT_START);
>>> -        ret = efi_bs->AllocatePages(AllocateMaxAddress, EfiLoaderData,
>>> -                                    PFN_UP(size), &file->addr);
>>> -    }
>>> +        goto fail;
>>> +
>>> +    what = L"Allocation";
>>> +    file->addr = min(1UL << (32 + PAGE_SHIFT),
>>> +                     HYPERVISOR_VIRT_END - DIRECTMAP_VIRT_START);
>>> +    ret = efi_bs->AllocatePages(AllocateMaxAddress, EfiLoaderData,
>>> +                                PFN_UP(size), &file->addr);
>>>      if ( EFI_ERROR(ret) )
>>> -        what = what ?: L"Allocation";
>>> -    else
>>> -    {
>>> -        file->need_to_free = true;
>>> -        file->size = size;
>>> -        handle_file_info(name, file, options);
>>> +        goto fail;
>>>
>>> -        ret = FileHandle->Read(FileHandle, &file->size, file->str);
>>> -        if ( !EFI_ERROR(ret) && file->size != size )
>>> -            ret = EFI_ABORTED;
>>> -        if ( EFI_ERROR(ret) )
>>> -            what = L"Read";
>>> -    }
>>> +    file->need_to_free = true;
>>> +    file->size = size;
>>> +    handle_file_info(name, file, options);
>>>
>>> -    if ( FileHandle )
>>> -        FileHandle->Close(FileHandle);
>>> +    what = L"Read";
>>> +    ret = FileHandle->Read(FileHandle, &file->size, file->str);
>>> +    if ( !EFI_ERROR(ret) && file->size != size )
>>> +        ret = EFI_ABORTED;
>>> +    if ( EFI_ERROR(ret) )
>>> +        goto fail;
>>>
>>> -    if ( what )
>>> -    {
>>> -        PrintErr(what);
>>> -        PrintErr(L" failed for ");
>>> -        PrintErrMesg(name, ret);
>>> -    }
>>> +    FileHandle->Close(FileHandle);
>>>
>>>      efi_arch_flush_dcache_area(file->ptr, file->size);
>>>
>>>      return true;
>>> +
>>> +fail:
>>
>> Nit: Style (see ./CODING_STYLE).
>>
> 
> What specifically? I checked the indentation and it's 4 spaces. if-s
> are spaced correctly. About labels I didn't find much on CODING_STYLE
> so I opened 3/4 files and most of them are indented with no spaces
> (they start at column 1).

You didn't search for the word "label" then, did you? Quote:

'Due to the behavior of GNU diffutils "diff -p", labels should be
 indented by at least one blank.  Non-case labels inside switch() bodies
 are preferred to be indented the same as the block's case labels.'

Jan