btrfs: disable various operations on encrypted inodes

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

Note: The patch was taken from v5 of fscrypt patchset
(https://lore.kernel.org/linux-btrfs/cover.1706116485.git.josef@toxicpanda.com/)
which was handled over time by various people: Omar Sandoval, Sweet Tea
Dorminy, Josef Bacik.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f71a5f7f55b9fa57454e7b4835aad9ce44832d8d..8e13117eca161543fb2565c74afde9446d0da40b 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -592,6 +592,10 @@ static bool can_cow_file_range_inline(struct btrfs_inode *inode,
        if (size < i_size_read(&inode->vfs_inode))
                return false;
 
+       /* Encrypted file cannot be inlined. */
+       if (IS_ENCRYPTED(&inode->vfs_inode))
+               return false;
+
        return true;
 }
 

diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index 775a32a7953a76d259352f9c8b995440c08d2e9e..b5fe95baf92edc34d85c69a5afbd8f4321d14794 100644 (file)
--- 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"
@@ -789,6 +790,10 @@ static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
                ASSERT(inode_in->vfs_inode.i_sb == inode_out->vfs_inode.i_sb);
        }
 
+       /* Can only reflink encrypted files if both files are encrypted. */
+       if (IS_ENCRYPTED(&inode_in->vfs_inode) != IS_ENCRYPTED(&inode_out->vfs_inode))
+               return -EINVAL;
+
        /* Don't make the dst file partly checksummed */
        if ((inode_in->flags & BTRFS_INODE_NODATASUM) !=
            (inode_out->flags & BTRFS_INODE_NODATASUM)) {