[RFC PATCH 17/19] btrfs: don't allow direct IO of encrypted extents

[Mark Harmstone <mark@harmstone.com>]

Signed-off-by: Mark Harmstone <mark@harmstone.com>
---
 fs/btrfs/inode.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f8bc7174f7e3..8f58f492abc8 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7945,6 +7945,17 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
 		goto unlock_err;
 	}
 
+	/*
+	 * Fallback to buffered IO if we have an encrypted inode,
+	 * as we would need to change what's in memory.
+	 */
+	if ((create && inode_need_encrypt(inode)) ||
+		test_bit(EXTENT_FLAG_ENCRYPTED, &em->flags)) {
+		free_extent_map(em);
+		ret = -ENOTBLK;
+		goto unlock_err;
+	}
+
 	if (create) {
 		ret = btrfs_get_blocks_direct_write(&em, bh_result, inode,
 						    dio_data, start, len);
-- 
2.19.2