Reimplement read_cache_page() as a wrapper around read_cache_folio().

Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
---
 include/linux/pagemap.h | 17 ++++++++-
 mm/filemap.c            | 81 +++++++++++++++++++----------------------
 2 files changed, 53 insertions(+), 45 deletions(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 22f9774d8a83..ae20b6fa46f0 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -518,19 +518,32 @@ static inline struct page *grab_cache_page(struct 
address_space *mapping,
        return find_or_create_page(mapping, index, mapping_gfp_mask(mapping));
 }
 
-extern struct page * read_cache_page(struct address_space *mapping,
-                               pgoff_t index, filler_t *filler, void *data);
+struct folio *read_cache_folio(struct address_space *mapping, pgoff_t index,
+               filler_t *filler, void *data);
 extern struct page * read_cache_page_gfp(struct address_space *mapping,
                                pgoff_t index, gfp_t gfp_mask);
 extern int read_cache_pages(struct address_space *mapping,
                struct list_head *pages, filler_t *filler, void *data);
 
+static inline struct page *read_cache_page(struct address_space *mapping,
+                               pgoff_t index, filler_t *filler, void *data)
+{
+       struct folio *folio = read_cache_folio(mapping, index, filler, data);
+       return folio_page(folio, index);
+}
+
 static inline struct page *read_mapping_page(struct address_space *mapping,
                                pgoff_t index, void *data)
 {
        return read_cache_page(mapping, index, NULL, data);
 }
 
+static inline struct folio *read_mapping_folio(struct address_space *mapping,
+                               pgoff_t index, void *data)
+{
+       return read_cache_folio(mapping, index, NULL, data);
+}
+
 /*
  * Get index of the page with in radix-tree
  * (TODO: remove once hugetlb pages will have ->index in PAGE_SIZE)
diff --git a/mm/filemap.c b/mm/filemap.c
index a5925450ee13..0131208e45f7 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3174,32 +3174,20 @@ EXPORT_SYMBOL(filemap_page_mkwrite);
 EXPORT_SYMBOL(generic_file_mmap);
 EXPORT_SYMBOL(generic_file_readonly_mmap);
 
-static struct page *wait_on_page_read(struct page *page)
-{
-       if (!IS_ERR(page)) {
-               wait_on_page_locked(page);
-               if (!PageUptodate(page)) {
-                       put_page(page);
-                       page = ERR_PTR(-EIO);
-               }
-       }
-       return page;
-}
-
-static struct page *do_read_cache_page(struct address_space *mapping,
+static struct folio *do_read_cache_folio(struct address_space *mapping,
                pgoff_t index, filler_t filler, void *data, gfp_t gfp)
 {
-       struct page *page;
+       struct folio *folio;
        int err;
 repeat:
-       page = find_get_page(mapping, index);
-       if (!page) {
-               page = &__page_cache_alloc(gfp, 0)->page;
-               if (!page)
+       folio = find_get_folio(mapping, index);
+       if (!folio) {
+               folio = __page_cache_alloc(gfp, 0);
+               if (!folio)
                        return ERR_PTR(-ENOMEM);
-               err = add_to_page_cache_lru(page, mapping, index, gfp);
+               err = folio_add_to_page_cache(folio, mapping, index, gfp);
                if (unlikely(err)) {
-                       put_page(page);
+                       put_folio(folio);
                        if (err == -EEXIST)
                                goto repeat;
                        /* Presumably ENOMEM for xarray node */
@@ -3208,21 +3196,24 @@ static struct page *do_read_cache_page(struct 
address_space *mapping,
 
 filler:
                if (filler)
-                       err = filler(data, page_folio(page));
+                       err = filler(data, folio);
                else
-                       err = mapping->a_ops->readpage(data, page_folio(page));
+                       err = mapping->a_ops->readpage(data, folio);
 
                if (err < 0) {
-                       put_page(page);
+                       put_folio(folio);
                        return ERR_PTR(err);
                }
 
-               page = wait_on_page_read(page);
-               if (IS_ERR(page))
-                       return page;
+               wait_on_folio_locked(folio);
+               if (!FolioUptodate(folio)) {
+                       put_folio(folio);
+                       return ERR_PTR(-EIO);
+               }
+
                goto out;
        }
-       if (PageUptodate(page))
+       if (FolioUptodate(folio))
                goto out;
 
        /*
@@ -3256,23 +3247,23 @@ static struct page *do_read_cache_page(struct 
address_space *mapping,
         * avoid spurious serialisations and wakeups when multiple processes
         * wait on the same page for IO to complete.
         */
-       wait_on_page_locked(page);
-       if (PageUptodate(page))
+       wait_on_folio_locked(folio);
+       if (FolioUptodate(folio))
                goto out;
 
        /* Distinguish between all the cases under the safety of the lock */
-       lock_page(page);
+       lock_folio(folio);
 
        /* Case c or d, restart the operation */
-       if (!page->mapping) {
-               unlock_page(page);
-               put_page(page);
+       if (!folio->page.mapping) {
+               unlock_folio(folio);
+               put_folio(folio);
                goto repeat;
        }
 
        /* Someone else locked and filled the page in a very small window */
-       if (PageUptodate(page)) {
-               unlock_page(page);
+       if (FolioUptodate(folio)) {
+               unlock_folio(folio);
                goto out;
        }
 
@@ -3282,16 +3273,16 @@ static struct page *do_read_cache_page(struct 
address_space *mapping,
         * Clear page error before actual read, PG_error will be
         * set again if read page fails.
         */
-       ClearPageError(page);
+       ClearFolioError(folio);
        goto filler;
 
 out:
-       mark_page_accessed(page);
-       return page;
+       mark_folio_accessed(folio);
+       return folio;
 }
 
 /**
- * read_cache_page - read into page cache, fill it if needed
+ * read_cache_folio - read into page cache, fill it if needed
  * @mapping:   the page's address_space
  * @index:     the page index
  * @filler:    function to perform the read
@@ -3304,13 +3295,13 @@ static struct page *do_read_cache_page(struct 
address_space *mapping,
  *
  * Return: up to date page on success, ERR_PTR() on failure.
  */
-struct page *read_cache_page(struct address_space *mapping, pgoff_t index,
+struct folio *read_cache_folio(struct address_space *mapping, pgoff_t index,
                filler_t filler, void *data)
 {
-       return do_read_cache_page(mapping, index, filler, data,
+       return do_read_cache_folio(mapping, index, filler, data,
                        mapping_gfp_mask(mapping));
 }
-EXPORT_SYMBOL(read_cache_page);
+EXPORT_SYMBOL(read_cache_folio);
 
 /**
  * read_cache_page_gfp - read into page cache, using specified page allocation 
flags.
@@ -3329,7 +3320,11 @@ struct page *read_cache_page_gfp(struct address_space 
*mapping,
                                pgoff_t index,
                                gfp_t gfp)
 {
-       return do_read_cache_page(mapping, index, NULL, NULL, gfp);
+       struct folio *folio = do_read_cache_folio(mapping, index, NULL, NULL,
+                                                                       gfp);
+       if (IS_ERR(folio))
+               return &folio->page;
+       return folio_page(folio, index);
 }
 EXPORT_SYMBOL(read_cache_page_gfp);
 
-- 
2.29.2

Reply via email to