filemap: Convert filemap_read() to use a folio

We know the pagevec always contains folios, but use page_folio() anyway
instead of casting.  Removes a few calls to legacy functions.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>

diff --git a/mm/filemap.c b/mm/filemap.c
index 72ea824db6f075c510a55cc33bedc4504c2fbd43..ea5460e1255563867ef769f85ddb24851464f6b8 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2668,30 +2668,26 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter,
                        mark_page_accessed(pvec.pages[0]);
 
                for (i = 0; i < pagevec_count(&pvec); i++) {
-                       struct page *page = pvec.pages[i];
-                       size_t page_size = thp_size(page);
-                       size_t offset = iocb->ki_pos & (page_size - 1);
+                       struct folio *folio = page_folio(pvec.pages[i]);
+                       size_t fsize = folio_size(folio);
+                       size_t offset = iocb->ki_pos & (fsize - 1);
                        size_t bytes = min_t(loff_t, end_offset - iocb->ki_pos,
-                                            page_size - offset);
+                                            fsize - offset);
                        size_t copied;
 
-                       if (end_offset < page_offset(page))
+                       if (end_offset < folio_pos(folio))
                                break;
                        if (i > 0)
-                               mark_page_accessed(page);
+                               folio_mark_accessed(folio);
                        /*
-                        * If users can be writing to this page using arbitrary
-                        * virtual addresses, take care about potential aliasing
-                        * before reading the page on the kernel side.
+                        * If users can be writing to this folio using arbitrary
+                        * virtual addresses, take care of potential aliasing
+                        * before reading the folio on the kernel side.
                         */
-                       if (writably_mapped) {
-                               int j;
-
-                               for (j = 0; j < thp_nr_pages(page); j++)
-                                       flush_dcache_page(page + j);
-                       }
+                       if (writably_mapped)
+                               flush_dcache_folio(folio);
 
-                       copied = copy_page_to_iter(page, offset, bytes, iter);
+                       copied = copy_folio_to_iter(folio, offset, bytes, iter);
 
                        already_read += copied;
                        iocb->ki_pos += copied;