shmem: convert shmem_get_link() to use a folio

Symlinks will never use a large folio, but using the folio API removes a
lot of unnecessary folio->page->folio conversions.

Link: https://lkml.kernel.org/r/20220902194653.1739778-31-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/shmem.c b/mm/shmem.c
index 4948cef..e6e934a 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3143,40 +3143,41 @@ static int shmem_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 
 static void shmem_put_link(void *arg)
 {
-       mark_page_accessed(arg);
-       put_page(arg);
+       folio_mark_accessed(arg);
+       folio_put(arg);
 }
 
 static const char *shmem_get_link(struct dentry *dentry,
                                  struct inode *inode,
                                  struct delayed_call *done)
 {
-       struct page *page = NULL;
+       struct folio *folio = NULL;
        int error;
+
        if (!dentry) {
-               page = find_get_page(inode->i_mapping, 0);
-               if (!page)
+               folio = filemap_get_folio(inode->i_mapping, 0);
+               if (!folio)
                        return ERR_PTR(-ECHILD);
-               if (PageHWPoison(page) ||
-                   !PageUptodate(page)) {
-                       put_page(page);
+               if (PageHWPoison(&folio->page) ||
+                   !folio_test_uptodate(folio)) {
+                       folio_put(folio);
                        return ERR_PTR(-ECHILD);
                }
        } else {
-               error = shmem_getpage(inode, 0, &page, SGP_READ);
+               error = shmem_get_folio(inode, 0, &folio, SGP_READ);
                if (error)
                        return ERR_PTR(error);
-               if (!page)
+               if (!folio)
                        return ERR_PTR(-ECHILD);
-               if (PageHWPoison(page)) {
-                       unlock_page(page);
-                       put_page(page);
+               if (PageHWPoison(&folio->page)) {
+                       folio_unlock(folio);
+                       folio_put(folio);
                        return ERR_PTR(-ECHILD);
                }
-               unlock_page(page);
+               folio_unlock(folio);
        }
-       set_delayed_call(done, shmem_put_link, page);
-       return page_address(page);
+       set_delayed_call(done, shmem_put_link, folio);
+       return folio_address(folio);
 }
 
 #ifdef CONFIG_TMPFS_XATTR