mm: drop page_index and simplify folio_index

There are two helpers for retrieving the index within address space for
mixed usage of swap cache and page cache:

- page_index
- folio_index

This commit drops page_index, as we have eliminated all users, and
converts folio_index's helper __page_file_index to use folio to avoid the
page conversion.

Link: https://lkml.kernel.org/r/20240521175854.96038-11-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Marc Dionne <marc.dionne@auristor.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index eb7c96d24ac02af320278387bca4a08f9dc6695d..99174fac3d47a52ab333d40afb5af7d5ef7f3673 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2295,19 +2295,6 @@ static inline void *folio_address(const struct folio *folio)
        return page_address(&folio->page);
 }
 
-extern pgoff_t __page_file_index(struct page *page);
-
-/*
- * Return the pagecache index of the passed page.  Regular pagecache pages
- * use ->index whereas swapcache pages use swp_offset(->private)
- */
-static inline pgoff_t page_index(struct page *page)
-{
-       if (unlikely(PageSwapCache(page)))
-               return __page_file_index(page);
-       return page->index;
-}
-
 /*
  * Return true only if the page has been allocated with
  * ALLOC_NO_WATERMARKS and the low watermark was not

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 78f2cd8c73ff7518ac2f73b1442d33ecae1e8910..1586b5c21e8161b963395c3f61c7763e9a737f64 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -792,7 +792,7 @@ static inline struct page *grab_cache_page_nowait(struct address_space *mapping,
                        mapping_gfp_mask(mapping));
 }
 
-#define swapcache_index(folio) __page_file_index(&(folio)->page)
+extern pgoff_t __folio_swap_cache_index(struct folio *folio);
 
 /**
  * folio_index - File index of a folio.
@@ -807,9 +807,9 @@ static inline struct page *grab_cache_page_nowait(struct address_space *mapping,
  */
 static inline pgoff_t folio_index(struct folio *folio)
 {
-        if (unlikely(folio_test_swapcache(folio)))
-                return swapcache_index(folio);
-        return folio->index;
+       if (unlikely(folio_test_swapcache(folio)))
+               return __folio_swap_cache_index(folio);
+       return folio->index;
 }
 
 /**

diff --git a/mm/swapfile.c b/mm/swapfile.c
index b3e5e384e330b44f1dd8cad237813ddecf3bf8f6..348c4d3ae078ae8ffacc66078fcc3484d59dda29 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3449,12 +3449,11 @@ struct address_space *swapcache_mapping(struct folio *folio)
 }
 EXPORT_SYMBOL_GPL(swapcache_mapping);
 
-pgoff_t __page_file_index(struct page *page)
+pgoff_t __folio_swap_cache_index(struct folio *folio)
 {
-       swp_entry_t swap = page_swap_entry(page);
-       return swp_offset(swap);
+       return swp_offset(folio->swap);
 }
-EXPORT_SYMBOL_GPL(__page_file_index);
+EXPORT_SYMBOL_GPL(__folio_swap_cache_index);
 
 /*
  * add_swap_count_continuation - called when a swap count is duplicated