[PATCH -next 2/2] squashfs: convert squashfs_read_folio to use folio APIs

[Li Zetao]

In order to remote page APIs and index field in structure page [1],
this patch convert squashfs_read_folio to use folio APIs, switch from
kmap_atomic to kmap_local and use folio_end_read() to set uptodate
and unlock folio.

[1]: https://lore.kernel.org/all/Zp8fgUSIBGQ1TN0D@xxxxxxxxxxxxxxxxxxxx/

Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Li Zetao <lizetao1@xxxxxxxxxx>
---
 fs/squashfs/file.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
index 893043ecf973..8c80d77a6115 100644
--- a/fs/squashfs/file.c
+++ b/fs/squashfs/file.c
@@ -446,10 +446,9 @@ static int squashfs_readpage_sparse(struct page *page, int expected)
 
 static int squashfs_read_folio(struct file *file, struct folio *folio)
 {
-	struct page *page = &folio->page;
-	struct inode *inode = page->mapping->host;
+	struct inode *inode = folio_inode(folio);
 	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
-	int index = page->index >> (msblk->block_log - PAGE_SHIFT);
+	int index = folio->index >> (msblk->block_log - PAGE_SHIFT);
 	int file_end = i_size_read(inode) >> msblk->block_log;
 	int expected = index == file_end ?
 			(i_size_read(inode) & (msblk->block_size - 1)) :
@@ -457,10 +456,10 @@ static int squashfs_read_folio(struct file *file, struct folio *folio)
 	int res = 0;
 	void *pageaddr;
 
-	TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n",
-				page->index, squashfs_i(inode)->start);
+	TRACE("Entered squashfs_readpage, folio index %lx, start block %llx\n",
+				folio->index, squashfs_i(inode)->start);
 
-	if (page->index >= ((i_size_read(inode) + PAGE_SIZE - 1) >>
+	if (folio->index >= ((i_size_read(inode) + PAGE_SIZE - 1) >>
 					PAGE_SHIFT))
 		goto out;
 
@@ -473,23 +472,21 @@ static int squashfs_read_folio(struct file *file, struct folio *folio)
 			goto out;
 
 		if (res == 0)
-			res = squashfs_readpage_sparse(page, expected);
+			res = squashfs_readpage_sparse(&folio->page, expected);
 		else
-			res = squashfs_readpage_block(page, block, res, expected);
+			res = squashfs_readpage_block(&folio->page, block, res, expected);
 	} else
-		res = squashfs_readpage_fragment(page, expected);
+		res = squashfs_readpage_fragment(&folio->page, expected);
 
 	if (!res)
 		return 0;
 
 out:
-	pageaddr = kmap_atomic(page);
+	pageaddr = kmap_local_folio(folio, 0);
 	memset(pageaddr, 0, PAGE_SIZE);
-	kunmap_atomic(pageaddr);
-	flush_dcache_page(page);
-	if (res == 0)
-		SetPageUptodate(page);
-	unlock_page(page);
+	kunmap_local(pageaddr);
+	flush_dcache_folio(folio);
+	folio_end_read(folio, res == 0);
 
 	return res;
 }
-- 
2.34.1