[PATCH 21/31] ext4: Convert __ext4_journalled_writepage() to take a folio

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

Use the folio APIs throughout and remove a PAGE_SIZE assumption.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 fs/ext4/inode.c | 46 +++++++++++++++++++++++-----------------------
 1 file changed, 23 insertions(+), 23 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 727aa2e51a9d..9b2c21d0e1f3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -136,7 +136,7 @@ static inline int ext4_begin_ordered_truncate(struct inode *inode,
 						   new_size);
 }
 
-static int __ext4_journalled_writepage(struct page *page, unsigned int len);
+static int __ext4_journalled_writepage(struct folio *folio, unsigned int len);
 static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
 				  int pextents);
 
@@ -1891,10 +1891,10 @@ int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 	return 0;
 }
 
-static int __ext4_journalled_writepage(struct page *page,
+static int __ext4_journalled_writepage(struct folio *folio,
 				       unsigned int len)
 {
-	struct address_space *mapping = page->mapping;
+	struct address_space *mapping = folio->mapping;
 	struct inode *inode = mapping->host;
 	handle_t *handle = NULL;
 	int ret = 0, err = 0;
@@ -1902,37 +1902,38 @@ static int __ext4_journalled_writepage(struct page *page,
 	struct buffer_head *inode_bh = NULL;
 	loff_t size;
 
-	ClearPageChecked(page);
+	folio_clear_checked(folio);
 
 	if (inline_data) {
-		BUG_ON(page->index != 0);
+		BUG_ON(folio->index != 0);
 		BUG_ON(len > ext4_get_max_inline_size(inode));
-		inode_bh = ext4_journalled_write_inline_data(inode, len, page);
+		inode_bh = ext4_journalled_write_inline_data(inode, len,
+							     &folio->page);
 		if (inode_bh == NULL)
 			goto out;
 	}
 	/*
-	 * We need to release the page lock before we start the
-	 * journal, so grab a reference so the page won't disappear
+	 * We need to release the folio lock before we start the
+	 * journal, so grab a reference so the folio won't disappear
 	 * out from under us.
 	 */
-	get_page(page);
-	unlock_page(page);
+	folio_get(folio);
+	folio_unlock(folio);
 
 	handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
 				    ext4_writepage_trans_blocks(inode));
 	if (IS_ERR(handle)) {
 		ret = PTR_ERR(handle);
-		put_page(page);
+		folio_put(folio);
 		goto out_no_pagelock;
 	}
 	BUG_ON(!ext4_handle_valid(handle));
 
-	lock_page(page);
-	put_page(page);
+	folio_lock(folio);
+	folio_put(folio);
 	size = i_size_read(inode);
-	if (page->mapping != mapping || page_offset(page) > size) {
-		/* The page got truncated from under us */
+	if (folio->mapping != mapping || folio_pos(folio) > size) {
+		/* The folio got truncated from under us */
 		ext4_journal_stop(handle);
 		ret = 0;
 		goto out;
@@ -1941,12 +1942,11 @@ static int __ext4_journalled_writepage(struct page *page,
 	if (inline_data) {
 		ret = ext4_mark_inode_dirty(handle, inode);
 	} else {
-		struct buffer_head *page_bufs = page_buffers(page);
+		struct buffer_head *page_bufs = folio_buffers(folio);
 
-		if (page->index == size >> PAGE_SHIFT)
-			len = size & ~PAGE_MASK;
-		else
-			len = PAGE_SIZE;
+		len = folio_size(folio);
+		if (folio_pos(folio) + len > size)
+			len = size - folio_pos(folio);
 
 		ret = ext4_walk_page_buffers(handle, inode, page_bufs, 0, len,
 					     NULL, do_journal_get_write_access);
@@ -1956,7 +1956,7 @@ static int __ext4_journalled_writepage(struct page *page,
 	}
 	if (ret == 0)
 		ret = err;
-	err = ext4_jbd2_inode_add_write(handle, inode, page_offset(page), len);
+	err = ext4_jbd2_inode_add_write(handle, inode, folio_pos(folio), len);
 	if (ret == 0)
 		ret = err;
 	EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
@@ -1966,7 +1966,7 @@ static int __ext4_journalled_writepage(struct page *page,
 
 	ext4_set_inode_state(inode, EXT4_STATE_JDATA);
 out:
-	unlock_page(page);
+	folio_unlock(folio);
 out_no_pagelock:
 	brelse(inode_bh);
 	return ret;
@@ -2086,7 +2086,7 @@ static int ext4_writepage(struct page *page,
 		 * It's mmapped pagecache.  Add buffers and journal it.  There
 		 * doesn't seem much point in redirtying the folio here.
 		 */
-		return __ext4_journalled_writepage(page, len);
+		return __ext4_journalled_writepage(folio, len);
 
 	ext4_io_submit_init(&io_submit, wbc);
 	io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS);
-- 
2.35.1