mm: make mapping_get_entry available outside of filemap.c

mapping_get_entry is useful for page cache API users that need to know
about xa_value internals.  Rename it and make it available in pagemap.h.

Link: https://lkml.kernel.org/r/20230307143410.28031-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 853184a..bcfd798 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -507,6 +507,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping,
 #define FGP_ENTRY              0x00000080
 #define FGP_STABLE             0x00000100
 
+void *filemap_get_entry(struct address_space *mapping, pgoff_t index);
 struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
                int fgp_flags, gfp_t gfp);
 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,

diff --git a/mm/filemap.c b/mm/filemap.c
index 2723104..a674108 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1836,7 +1836,7 @@ EXPORT_SYMBOL(page_cache_prev_miss);
  */
 
 /*
- * mapping_get_entry - Get a page cache entry.
+ * filemap_get_entry - Get a page cache entry.
  * @mapping: the address_space to search
  * @index: The page cache index.
  *
@@ -1847,7 +1847,7 @@ EXPORT_SYMBOL(page_cache_prev_miss);
  *
  * Return: The folio, swap or shadow entry, %NULL if nothing is found.
  */
-static void *mapping_get_entry(struct address_space *mapping, pgoff_t index)
+void *filemap_get_entry(struct address_space *mapping, pgoff_t index)
 {
        XA_STATE(xas, &mapping->i_pages, index);
        struct folio *folio;
@@ -1917,7 +1917,7 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
        struct folio *folio;
 
 repeat:
-       folio = mapping_get_entry(mapping, index);
+       folio = filemap_get_entry(mapping, index);
        if (xa_is_value(folio)) {
                if (fgp_flags & FGP_ENTRY)
                        return folio;