Cannot parse struct or union error on mm-everything

From: Bagas Sanjaya
Date: Fri Nov 18 2022 - 23:11:35 EST


Greetings,

I found a new htmldocs warning on mm-everything:

WARNING: kernel-doc './scripts/kernel-doc -rst -enable-lineno -sphinx-version 2.4.4 -internal ./include/linux/mm_types.h' failed with return code 1

Checking the header with './scripts/kernel-doc -v -none
./include/linux/mm_types.h', I got the full error:

include/linux/mm_types.h:255: info: Scanning doc for struct encoded_page
include/linux/mm_types.h:268: error: Cannot parse struct or union!
include/linux/mm_types.h:287: info: Scanning doc for struct folio
include/linux/mm_types.h:917: info: Scanning doc for typedef vm_fault_t
include/linux/mm_types.h:924: info: Scanning doc for enum vm_fault_reason
include/linux/mm_types.h:1028: info: Scanning doc for enum fault_flag
1 errors

The culprit is encoded_page struct, which is null struct (nonexistent type)
with kernel-doc comments:

/**
* struct encoded_page - a nonexistent type marking this pointer
*
* An 'encoded_page' pointer is a pointer to a regular 'struct page', but
* with the low bits of the pointer indicating extra context-dependent
* information. Not super-common, but happens in mmu_gather and mlock
* handling, and this acts as a type system check on that use.
*
* We only really have two guaranteed bits in general, although you could
* play with 'struct page' alignment (see CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
* for more.
*
* Use the supplied helper functions to endcode/decode the pointer and bits.
*/
struct encoded_page;

The struct is introduced by d57ab372568585 ("mm: introduce 'encoded' page
pointers with embedded extra bits").

Thanks.

--
An old man doll... just what I always wanted! - Clara

Attachment: signature.asc
Description: PGP signature