nilfs2: convert nilfs_prepare_chunk() and nilfs_commit_chunk() to folios

All callers now have a folio, so convert these two functions.
Saves one call to compound_head() in unlock_page().

[konishi.ryusuke: resolved conflicts in nilfs_{set_link,delete_entry}]
Link: https://lkml.kernel.org/r/20231127143036.2425-17-konishi.ryusuke@gmail.comSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/nilfs2/dir.c

@@ -78,33 +78,32 @@ static unsigned int nilfs_last_byte(struct inode *inode, unsigned long page_nr)
 	return last_byte;
 }
 
-static int nilfs_prepare_chunk(struct page *page, unsigned int from,
+static int nilfs_prepare_chunk(struct folio *folio, unsigned int from,
 			       unsigned int to)
 {
-	loff_t pos = page_offset(page) + from;
+	loff_t pos = folio_pos(folio) + from;
 
-	return __block_write_begin(page, pos, to - from, nilfs_get_block);
+	return __block_write_begin(&folio->page, pos, to - from, nilfs_get_block);
 }
 
-static void nilfs_commit_chunk(struct page *page,
-			       struct address_space *mapping,
-			       unsigned int from, unsigned int to)
+static void nilfs_commit_chunk(struct folio *folio,
+		struct address_space *mapping, size_t from, size_t to)
 {
 	struct inode *dir = mapping->host;
-	loff_t pos = page_offset(page) + from;
-	unsigned int len = to - from;
-	unsigned int nr_dirty, copied;
+	loff_t pos = folio_pos(folio) + from;
+	size_t copied, len = to - from;
+	unsigned int nr_dirty;
 	int err;
 
-	nr_dirty = nilfs_page_count_clean_buffers(page, from, to);
-	copied = block_write_end(NULL, mapping, pos, len, len, page, NULL);
+	nr_dirty = nilfs_page_count_clean_buffers(&folio->page, from, to);
+	copied = block_write_end(NULL, mapping, pos, len, len, &folio->page, NULL);
 	if (pos + copied > dir->i_size)
 		i_size_write(dir, pos + copied);
 	if (IS_DIRSYNC(dir))
 		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 	err = nilfs_set_file_dirty(dir, nr_dirty);
 	WARN_ON(err); /* do not happen */
-	unlock_page(page);
+	folio_unlock(folio);
 }
 
 static bool nilfs_check_folio(struct folio *folio, char *kaddr)
@@ -409,11 +408,11 @@ void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de,
 	int err;
 
 	folio_lock(folio);
-	err = nilfs_prepare_chunk(&folio->page, from, to);
+	err = nilfs_prepare_chunk(folio, from, to);
 	BUG_ON(err);
 	de->inode = cpu_to_le64(inode->i_ino);
 	nilfs_set_de_type(de, inode);
-	nilfs_commit_chunk(&folio->page, mapping, from, to);
+	nilfs_commit_chunk(folio, mapping, from, to);
 	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 }
 
@@ -485,7 +484,7 @@ int nilfs_add_link(struct dentry *dentry, struct inode *inode)
 got_it:
 	from = offset_in_folio(folio, de);
 	to = from + rec_len;
-	err = nilfs_prepare_chunk(&folio->page, from, to);
+	err = nilfs_prepare_chunk(folio, from, to);
 	if (err)
 		goto out_unlock;
 	if (de->inode) {
@@ -500,7 +499,7 @@ int nilfs_add_link(struct dentry *dentry, struct inode *inode)
 	memcpy(de->name, name, namelen);
 	de->inode = cpu_to_le64(inode->i_ino);
 	nilfs_set_de_type(de, inode);
-	nilfs_commit_chunk(&folio->page, folio->mapping, from, to);
+	nilfs_commit_chunk(folio, folio->mapping, from, to);
 	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 	nilfs_mark_inode_dirty(dir);
 	/* OFFSET_CACHE */
@@ -542,12 +541,12 @@ int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct folio *folio)
 	if (pde)
 		from = (char *)pde - kaddr;
 	folio_lock(folio);
-	err = nilfs_prepare_chunk(&folio->page, from, to);
+	err = nilfs_prepare_chunk(folio, from, to);
 	BUG_ON(err);
 	if (pde)
 		pde->rec_len = nilfs_rec_len_to_disk(to - from);
 	dir->inode = 0;
-	nilfs_commit_chunk(&folio->page, mapping, from, to);
+	nilfs_commit_chunk(folio, mapping, from, to);
 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
 out:
 	return err;
@@ -568,7 +567,7 @@ int nilfs_make_empty(struct inode *inode, struct inode *parent)
 	if (IS_ERR(folio))
 		return PTR_ERR(folio);
 
-	err = nilfs_prepare_chunk(&folio->page, 0, chunk_size);
+	err = nilfs_prepare_chunk(folio, 0, chunk_size);
 	if (unlikely(err)) {
 		folio_unlock(folio);
 		goto fail;
@@ -589,7 +588,7 @@ int nilfs_make_empty(struct inode *inode, struct inode *parent)
 	memcpy(de->name, "..\0", 4);
 	nilfs_set_de_type(de, inode);
 	kunmap_local(kaddr);
-	nilfs_commit_chunk(&folio->page, mapping, 0, chunk_size);
+	nilfs_commit_chunk(folio, mapping, 0, chunk_size);
 fail:
 	folio_put(folio);
 	return err;