[PATCH v3 01/17] btrfs: disable various operations on encrypted inodes

[Sweet Tea Dorminy <sweettea-kernel@dorminy.me>]

From: Omar Sandoval <osandov@osandov.com>

Initially, only normal data extents will be encrypted. This change
forbids various other bits:
- allows reflinking only if both inodes have the same encryption status
- disable inline data on encrypted inodes

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
---
 fs/btrfs/inode.c   | 3 ++-
 fs/btrfs/reflink.c | 7 +++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6a68d5a3ed20..bb9e1e608488 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -629,7 +629,8 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
 	 * compressed) data fits in a leaf and the configured maximum inline
 	 * size.
 	 */
-	if (size < i_size_read(&inode->vfs_inode) ||
+	if (IS_ENCRYPTED(&inode->vfs_inode) ||
+	    size < i_size_read(&inode->vfs_inode) ||
 	    size > fs_info->sectorsize ||
 	    data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
 	    data_len > fs_info->max_inline)
diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index 0474bbe39da7..ad722f495c9b 100644
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include <linux/blkdev.h>
+#include <linux/fscrypt.h>
 #include <linux/iversion.h>
 #include "ctree.h"
 #include "fs.h"
@@ -811,6 +812,12 @@ static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
 		ASSERT(inode_in->i_sb == inode_out->i_sb);
 	}
 
+	/*
+	 * Can only reflink encrypted files if both files are encrypted.
+	 */
+	if (IS_ENCRYPTED(inode_in) != IS_ENCRYPTED(inode_out))
+		return -EINVAL;
+
 	/* Don't make the dst file partly checksummed */
 	if ((BTRFS_I(inode_in)->flags & BTRFS_INODE_NODATASUM) !=
 	    (BTRFS_I(inode_out)->flags & BTRFS_INODE_NODATASUM)) {
-- 
2.41.0