ext2_get_page(): saner type

We need to pass to caller both the page reference and pointer to the
first byte in the now-mapped page.  The former always has the same type,
the latter varies from caller to caller.  So make it
	void *ext2_get_page(...., struct page **page)
rather than
	struct page *ext2_get_page(..., void **page_addr)
and avoid the casts...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Tested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 5141ec6..75c8f80 100644 (file)
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -186,23 +186,25 @@ fail:
  * NOTE: ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_page()
  * and should be treated as a call to ext2_get_page() for nesting purposes.
  */
-static struct page * ext2_get_page(struct inode *dir, unsigned long n,
-                                  int quiet, void **page_addr)
+static void *ext2_get_page(struct inode *dir, unsigned long n,
+                                  int quiet, struct page **page)
 {
        struct address_space *mapping = dir->i_mapping;
        struct folio *folio = read_mapping_folio(mapping, n, NULL);
+       void *page_addr;
 
        if (IS_ERR(folio))
-               return &folio->page;
-       *page_addr = kmap_local_folio(folio, n & (folio_nr_pages(folio) - 1));
+               return ERR_CAST(folio);
+       page_addr = kmap_local_folio(folio, n & (folio_nr_pages(folio) - 1));
        if (unlikely(!folio_test_checked(folio))) {
-               if (!ext2_check_page(&folio->page, quiet, *page_addr))
+               if (!ext2_check_page(&folio->page, quiet, page_addr))
                        goto fail;
        }
-       return &folio->page;
+       *page = &folio->page;
+       return page_addr;
 
 fail:
-       ext2_put_page(&folio->page, *page_addr);
+       ext2_put_page(&folio->page, page_addr);
        return ERR_PTR(-EIO);
 }
 
@@ -271,16 +273,17 @@ ext2_readdir(struct file *file, struct dir_context *ctx)
                EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE);
 
        for ( ; n < npages; n++, offset = 0) {
-               char *kaddr, *limit;
                ext2_dirent *de;
-               struct page *page = ext2_get_page(inode, n, 0, (void **)&kaddr);
+               struct page *page;
+               char *kaddr = ext2_get_page(inode, n, 0, &page);
+               char *limit;
 
-               if (IS_ERR(page)) {
+               if (IS_ERR(kaddr)) {
                        ext2_error(sb, __func__,
                                   "bad page in #%lu",
                                   inode->i_ino);
                        ctx->pos += PAGE_SIZE - offset;
-                       return PTR_ERR(page);
+                       return PTR_ERR(kaddr);
                }
                if (unlikely(need_revalidate)) {
                        if (offset) {
@@ -362,9 +365,10 @@ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
        n = start;
        do {
                char *kaddr;
-               page = ext2_get_page(dir, n, 0, &page_addr);
-               if (IS_ERR(page))
-                       return ERR_CAST(page);
+
+               page_addr = ext2_get_page(dir, n, 0, &page);
+               if (IS_ERR(page_addr))
+                       return ERR_CAST(page_addr);
 
                kaddr = page_addr;
                de = (ext2_dirent *) kaddr;
@@ -418,13 +422,11 @@ found:
 struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct page **p,
                                     void **pa)
 {
-       void *page_addr;
-       struct page *page = ext2_get_page(dir, 0, 0, &page_addr);
+       void *page_addr = ext2_get_page(dir, 0, 0, p);
        ext2_dirent *de = NULL;
 
-       if (!IS_ERR(page)) {
+       if (!IS_ERR(page_addr)) {
                de = ext2_next_entry((ext2_dirent *) page_addr);
-               *p = page;
                *pa = page_addr;
        }
        return de;
@@ -513,10 +515,9 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
                char *kaddr;
                char *dir_end;
 
-               page = ext2_get_page(dir, n, 0, &page_addr);
-               err = PTR_ERR(page);
-               if (IS_ERR(page))
-                       goto out;
+               page_addr = ext2_get_page(dir, n, 0, &page);
+               if (IS_ERR(page_addr))
+                       return PTR_ERR(page_addr);
                lock_page(page);
                kaddr = page_addr;
                dir_end = kaddr + ext2_last_byte(dir, n);
@@ -577,7 +578,6 @@ got_it:
        /* OFFSET_CACHE */
 out_put:
        ext2_put_page(page, page_addr);
-out:
        return err;
 out_unlock:
        unlock_page(page);
@@ -682,9 +682,9 @@ int ext2_empty_dir (struct inode * inode)
        for (i = 0; i < npages; i++) {
                char *kaddr;
                ext2_dirent * de;
-               page = ext2_get_page(inode, i, 0, &page_addr);
+               page_addr = ext2_get_page(inode, i, 0, &page);
 
-               if (IS_ERR(page))
+               if (IS_ERR(page_addr))
                        return 0;
 
                kaddr = page_addr;