[v1,12/17] btrfs: turn on inlinecrypt mount option for encrypt

Commit Message

Sweet Tea Dorminy June 29, 2023, 12:35 a.m. UTC

fscrypt's extent encryption requires the use of inline encryption or the
software fallback that the block layer provides; it is rather
complicated to allow software encryption with extent encryption due to
the timing of memory allocations. Thus, if btrfs has ever had a
encrypted file, or when encryption is enabled on a directory, update the
mount flags to include inlinecrypt.
---
 fs/btrfs/ioctl.c |  4 ++++
 fs/btrfs/super.c | 10 ++++++++++
 2 files changed, 14 insertions(+)

Patch

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7c4360b59aae..384bad37fa9d 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4574,6 +4574,10 @@  long btrfs_ioctl(struct file *file, unsigned int
 		 * state persists.
 		 */
 		btrfs_set_fs_incompat(fs_info, ENCRYPT);
+		if (!(inode->i_sb->s_flags & SB_INLINECRYPT)) {
+			inode->i_sb->s_flags |= SB_INLINECRYPT;
+			mb();
+		}
 		return fscrypt_ioctl_set_policy(file, (const void __user *)arg);
 	}
 	case FS_IOC_GET_ENCRYPTION_POLICY:
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index ad18127cee10..d1c192dcd800 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1161,6 +1161,16 @@  static int btrfs_fill_super(struct super_block *sb,
 		return err;
 	}
 
+	if (btrfs_fs_incompat(fs_info, ENCRYPT)) {
+		if (IS_ENABLED(CONFIG_FS_ENCRYPTION_INLINE_CRYPT)) {
+			sb->s_flags |= SB_INLINECRYPT;
+		} else {
+			btrfs_err(fs_info, "encryption not supported");
+			err = -EINVAL;
+			goto fail_close;
+		}
+	}
+
 	inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);