[PATCH 2/6] iomap: support invalidating partial folios

[Zhang Yi]

From: Zhang Yi <yi.zhang@xxxxxxxxxx>

Current iomap_invalidate_folio() could only invalidate an entire folio,
if we truncate a partial folio on a filesystem with blocksize < folio
size, it will left over the dirty bits of truncated/punched blocks, and
the write back process will try to map the invalid hole range, but
fortunately it hasn't trigger any real problems now since ->map_blocks()
will fix the length. Fix this by supporting invalidating partial folios.

Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
 fs/iomap/buffered-io.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index a896d15c191a..64c4808fab31 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -631,6 +631,8 @@ void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len)
 		WARN_ON_ONCE(folio_test_writeback(folio));
 		folio_cancel_dirty(folio);
 		ifs_free(folio);
+	} else {
+		iomap_clear_range_dirty(folio, offset, len);
 	}
 }
 EXPORT_SYMBOL_GPL(iomap_invalidate_folio);
-- 
2.39.2