| Message ID | 20210405151355.9867-1-rppt@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | minor cleanups of include/linux/mm.h | expand |
On Mon, Apr 05, 2021 at 06:13:53PM +0300, Mike Rapoport wrote: > I've also noticed that except page_mapping_file() we have somewhat similar > page_file_mapping(), which seems superfluous, but I didn't dig further to > see how one of them can be dropped. They can't ;-( I looked at it, and they do different things. + * folio_file_mapping - Find the mapping this folio belongs to. + * @folio: The folio. + * + * For folios which are in the page cache, return the mapping that this + * page belongs to. Folios in the swap cache return the mapping of the + * swap file or swap device where the data is stored. This is different + * from the mapping returned by folio_mapping(). The only reason to + * use it is if, like NFS, you return 0 from ->activate_swapfile. page_mapping_file() returns NULL for pages which are in the swap cache, as they no longer need the dcache flushed.
From: Mike Rapoport <rppt@linux.ibm.com> Hi, While looking at recent page_mapping_file() changes I've noticed that page_rmapping() and page_anon_vma() could be moved from include/linux/mm.h and we don't need two forward declarations of page_mapping(). I've also noticed that except page_mapping_file() we have somewhat similar page_file_mapping(), which seems superfluous, but I didn't dig further to see how one of them can be dropped. The patches are vs v5.12-rc5-mmots-2021-03-31-22-26. Mike Rapoport (2): mm: move page_rmapping() and page_anon_vma() to mm/internal.h include/linux/mm.h: remove duplicated declaration of page_mapping() include/linux/mm.h | 4 ---- mm/internal.h | 3 +++ 2 files changed, 3 insertions(+), 4 deletions(-)