fuse: hook into iomap for invalidating and checking partial uptodateness

Hook into iomap_invalidate_folio() so that if the entire folio is being
invalidated during truncation, the dirty state is cleared and the folio
doesn't get written back. As well the folio's corresponding ifs struct
will get freed.

Hook into iomap_is_partially_uptodate() since iomap tracks uptodateness
granularly when it does buffered writes.

Signed-off-by: Joanne Koong <[email protected]>
Link: https://lore.kernel.org/[email protected]
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

Author: joannekoong

fs/fuse/file.c

@@ -3110,6 +3110,8 @@ static const struct address_space_operations fuse_file_aops  = {
 	.launder_folio	= fuse_launder_folio,
 	.dirty_folio	= iomap_dirty_folio,
 	.release_folio	= iomap_release_folio,
+	.invalidate_folio = iomap_invalidate_folio,
+	.is_partially_uptodate = iomap_is_partially_uptodate,
 	.migrate_folio	= filemap_migrate_folio,
 	.bmap		= fuse_bmap,
 	.direct_IO	= fuse_direct_IO,