[PATCH v3 3/4] ntfs: Use zero_user_segment() in handle_bounds_compressed_page()

From: "Matthew Wilcox (Oracle)" <[email protected]>

This fixes handle_bounds_compressed_page() on highmem memory
as page_address() does not work on memory which has been kmap_local(),
only on kmap() memory.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Hyunchul Lee <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>
Acked-by: Namjae Jeon <[email protected]>
---
 fs/ntfs/compress.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/fs/ntfs/compress.c b/fs/ntfs/compress.c
index 8078041b8796..f03fae63c199 100644
--- a/fs/ntfs/compress.c
+++ b/fs/ntfs/compress.c
@@ -109,16 +109,16 @@ static inline void handle_bounds_compressed_page(struct page *page,
 
 	if ((pos + PAGE_SIZE > initialized_size) &&
 			(initialized_size < i_size)) {
-		u8 *kp = page_address(page);
-		unsigned int kp_ofs;
+		size_t offset;
 
 		ntfs_debug("Zeroing page region outside initialized size.");
-		if (pos >= initialized_size) {
-			clear_page(kp);
-			return;
-		}
-		kp_ofs = initialized_size & ~PAGE_MASK;
-		memset(kp + kp_ofs, 0, PAGE_SIZE - kp_ofs);
+		if (pos >= initialized_size)
+			offset = 0;
+		else
+			offset = offset_in_page(initialized_size);
+		zero_user_segment(page, offset, PAGE_SIZE);
+	} else {
+		flush_dcache_page(page);
 	}
 }
 
@@ -223,7 +223,6 @@ static int ntfs_decompress(struct page *dest_pages[], int completed_pages[],
 				 */
 				handle_bounds_compressed_page(dp, i_size,
 						initialized_size);
-				flush_dcache_page(dp);
 				kunmap_local(page_address(dp));
 				SetPageUptodate(dp);
 				unlock_page(dp);
@@ -759,7 +758,6 @@ int ntfs_read_compressed_block(struct folio *folio)
 				 */
 				handle_bounds_compressed_page(page, i_size,
 						initialized_size);
-				flush_dcache_page(page);
 				kunmap_local(page_address(page));
 				SetPageUptodate(page);
 				unlock_page(page);

-- 
2.43.0