[PATCH] ecryptfs: use filemap_dirty_folio for address space operations

ecryptfs does not use buffer_heads. The legacy block_dirty_folio and
block_invalidate_folio mapping operations were only added as a
temporary compatibility fallback under CONFIG_BLOCK.

Since ecryptfs does not attach private metadata (such as buffer_heads)
to its folios, block_dirty_folio is unnecessary.

Modernize ecryptfs to use filemap_dirty_folio for its dirty_folio
address space operation. This allows removing the block_dirty_folio
and block_invalidate_folio fallbacks, removing the buffer_head header
include, and removing the CONFIG_BLOCK dependency inside ecryptfs_aops.

Signed-off-by: Aditya Prakash Srivastava <[email protected]>
---
 fs/ecryptfs/mmap.c | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 2c2b12fedeae..a057472b409c 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -510,21 +510,8 @@ static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
 	return block;
 }
 
-#include <linux/buffer_head.h>
-
 const struct address_space_operations ecryptfs_aops = {
-	/*
-	 * XXX: This is pretty broken for multiple reasons: ecryptfs does not
-	 * actually use buffer_heads, and ecryptfs will crash without
-	 * CONFIG_BLOCK.  But it matches the behavior before the default for
-	 * address_space_operations without the ->dirty_folio method was
-	 * cleaned up, so this is the best we can do without maintainer
-	 * feedback.
-	 */
-#ifdef CONFIG_BLOCK
-	.dirty_folio	= block_dirty_folio,
-	.invalidate_folio = block_invalidate_folio,
-#endif
+	.dirty_folio	= filemap_dirty_folio,
 	.writepages = ecryptfs_writepages,
 	.read_folio = ecryptfs_read_folio,
 	.write_begin = ecryptfs_write_begin,
-- 
2.47.3