Commit af10dd16 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Johannes Berg
Browse files

hostfs: Convert to writepages 



If we add a migrate_folio operation, we can convert the writepage
operation to writepages.  The large folio support here is illusory;
we would need to kmap each page in turn for proper support.  But we do
remove a few hidden calls to compound_head().

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Link: https://patch.msgid.link/20241220051500.1919389-1-willy@infradead.org


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 579e7fd3

fs/hostfs/hostfs_kern.c

+25 −29
Original line number Diff line number Diff line
@@ -410,37 +410,32 @@ static const struct file_operations hostfs_dir_fops = { 
	.fsync		= hostfs_fsync,

};



static int hostfs_writepage(struct page *page, struct writeback_control *wbc)

static int hostfs_writepages(struct address_space *mapping,

		struct writeback_control *wbc)

{

	struct address_space *mapping = page->mapping;

	struct inode *inode = mapping->host;

	char *buffer;

	loff_t base = page_offset(page);

	int count = PAGE_SIZE;

	int end_index = inode->i_size >> PAGE_SHIFT;

	int err;

	struct folio *folio = NULL;

	loff_t i_size = i_size_read(inode);

	int err = 0;



	if (page->index >= end_index)

		count = inode->i_size & (PAGE_SIZE-1);

	while ((folio = writeback_iter(mapping, wbc, folio, &err))) {

		loff_t pos = folio_pos(folio);

		size_t count = folio_size(folio);

		char *buffer;

		int ret;



	buffer = kmap_local_page(page);

		if (count > i_size - pos)

			count = i_size - pos;



	err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count);

	if (err != count) {

		if (err >= 0)

			err = -EIO;

		buffer = kmap_local_folio(folio, 0);

		ret = write_file(HOSTFS_I(inode)->fd, &pos, buffer, count);

		kunmap_local(buffer);

		folio_unlock(folio);

		if (ret != count) {

			err = ret < 0 ? ret : -EIO;

			mapping_set_error(mapping, err);

		goto out;

		}



	if (base > inode->i_size)

		inode->i_size = base;



	err = 0;



 out:

	kunmap_local(buffer);

	unlock_page(page);

	}



	return err;

}
@@ -506,11 +501,12 @@ static int hostfs_write_end(struct file *file, struct address_space *mapping, 
}



static const struct address_space_operations hostfs_aops = {

	.writepage 	= hostfs_writepage,

	.writepages 	= hostfs_writepages,

	.read_folio	= hostfs_read_folio,

	.dirty_folio	= filemap_dirty_folio,

	.write_begin	= hostfs_write_begin,

	.write_end	= hostfs_write_end,

	.migrate_folio	= filemap_migrate_folio,

};



static int hostfs_inode_update(struct inode *ino, const struct hostfs_stat *st)