mm/filemap: Add filemap_alloc_folio

Reimplement __page_cache_alloc as a wrapper around filemap_alloc_folio
to allow filesystems to be converted at our leisure.  Increases
kernel text size by 133 bytes, mostly in cachefiles_read_backing_file().
pagecache_get_page() shrinks by 32 bytes, though.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index fea9615bab357c48b6c11f822e40d97e702d7a29..51c190ae3b0b8a2e054b10afd32841ec5c98c881 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -262,14 +262,19 @@ static inline void *detach_page_private(struct page *page)
 }
 
 #ifdef CONFIG_NUMA
-extern struct page *__page_cache_alloc(gfp_t gfp);
+struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order);
 #else
-static inline struct page *__page_cache_alloc(gfp_t gfp)
+static inline struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order)
 {
-       return alloc_pages(gfp, 0);
+       return folio_alloc(gfp, order);
 }
 #endif
 
+static inline struct page *__page_cache_alloc(gfp_t gfp)
+{
+       return &filemap_alloc_folio(gfp, 0)->page;
+}
+
 static inline struct page *page_cache_alloc(struct address_space *x)
 {
        return __page_cache_alloc(mapping_gfp_mask(x));

diff --git a/mm/filemap.c b/mm/filemap.c
index c4a7f3fdca1275ccbbb7c51e1c59bae8bba192d1..6976fb4af390dbf25115ffac5656f92ca887a4d8 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1006,24 +1006,24 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
 
 #ifdef CONFIG_NUMA
-struct page *__page_cache_alloc(gfp_t gfp)
+struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order)
 {
        int n;
-       struct page *page;
+       struct folio *folio;
 
        if (cpuset_do_page_mem_spread()) {
                unsigned int cpuset_mems_cookie;
                do {
                        cpuset_mems_cookie = read_mems_allowed_begin();
                        n = cpuset_mem_spread_node();
-                       page = __alloc_pages_node(n, gfp, 0);
-               } while (!page && read_mems_allowed_retry(cpuset_mems_cookie));
+                       folio = __folio_alloc_node(gfp, order, n);
+               } while (!folio && read_mems_allowed_retry(cpuset_mems_cookie));
 
-               return page;
+               return folio;
        }
-       return alloc_pages(gfp, 0);
+       return folio_alloc(gfp, order);
 }
-EXPORT_SYMBOL(__page_cache_alloc);
+EXPORT_SYMBOL(filemap_alloc_folio);
 #endif
 
 /*