diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 719245d73b99..aedd8a0e4962 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1272,6 +1272,7 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
 	kfree(fs_info->super_copy);
 	kfree(fs_info->super_for_commit);
 	kfree(fs_info->subpage_info);
+	fscrypt_free_dummy_policy(&fs_info->dummy_enc_policy);
 	kvfree(fs_info);
 }
 
diff --git a/fs/btrfs/fs.h b/fs/btrfs/fs.h
index 1340e71d026c..74752204f3ab 100644
--- a/fs/btrfs/fs.h
+++ b/fs/btrfs/fs.h
@@ -7,6 +7,7 @@
 #include <linux/fs.h>
 #include <linux/btrfs_tree.h>
 #include <linux/sizes.h>
+#include <linux/fscrypt.h>
 #include "extent-io-tree.h"
 #include "extent_map.h"
 #include "async-thread.h"
@@ -189,6 +190,7 @@ enum {
 	BTRFS_MOUNT_IGNOREDATACSUMS		= (1UL << 28),
 	BTRFS_MOUNT_NODISCARD			= (1UL << 29),
 	BTRFS_MOUNT_NOSPACECACHE		= (1UL << 30),
+	BTRFS_MOUNT_TEST_DUMMY_ENCRYPTION	= (1UL << 31),
 };
 
 /*
@@ -828,6 +830,7 @@ struct btrfs_fs_info {
 	spinlock_t eb_leak_lock;
 	struct list_head allocated_ebs;
 #endif
+	struct fscrypt_dummy_policy dummy_enc_policy;
 };
 
 static inline u64 btrfs_get_fs_generation(const struct btrfs_fs_info *fs_info)
diff --git a/fs/btrfs/fscrypt.c b/fs/btrfs/fscrypt.c
index 85b596711371..2fbceec62dc7 100644
--- a/fs/btrfs/fscrypt.c
+++ b/fs/btrfs/fscrypt.c
@@ -242,6 +242,11 @@ static blk_status_t btrfs_process_encrypted_bio(struct bio *orig_bio,
 	return btrfs_csum_one_bio(bbio, enc_bio);
 }
 
+static const union fscrypt_policy *btrfs_get_dummy_policy(struct super_block *sb)
+{
+	return btrfs_sb(sb)->dummy_enc_policy.policy;
+}
+
 int btrfs_fscrypt_load_extent_info(struct btrfs_inode *inode,
 				   struct extent_map *em,
 				   struct btrfs_fscrypt_ctx *ctx)
@@ -357,4 +362,5 @@ const struct fscrypt_operations btrfs_fscrypt_ops = {
 	.empty_dir = btrfs_fscrypt_empty_dir,
 	.get_devices = btrfs_fscrypt_get_devices,
 	.process_bio = btrfs_process_encrypted_bio,
+	.get_dummy_policy = btrfs_get_dummy_policy,
 };
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 462a23db26af..2a7789519a6c 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -88,6 +88,7 @@ struct btrfs_fs_context {
 	unsigned long compress_type:4;
 	unsigned int compress_level;
 	refcount_t refs;
+	struct fscrypt_dummy_policy dummy_enc_policy;
 };
 
 enum {
@@ -122,6 +123,7 @@ enum {
 	Opt_thread_pool,
 	Opt_treelog,
 	Opt_user_subvol_rm_allowed,
+	Opt_test_dummy_encryption,
 
 	/* Rescue options */
 	Opt_rescue,
@@ -255,6 +257,13 @@ static const struct fs_parameter_spec btrfs_fs_parameters[] = {
 	fsparam_flag_no("enospc_debug", Opt_enospc_debug),
 #ifdef CONFIG_BTRFS_DEBUG
 	fsparam_enum("fragment", Opt_fragment, btrfs_parameter_fragment),
+
+	/*
+	 * With -o test_dummy_encryption we default to v2, only allow the flag
+	 * version, since we don't support v1.
+	 */
+	fsparam_flag("test_dummy_encryption", Opt_test_dummy_encryption),
+
 #endif
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 	fsparam_flag("ref_verify", Opt_ref_verify),
@@ -268,6 +277,7 @@ static int btrfs_parse_param(struct fs_context *fc,
 	struct btrfs_fs_context *ctx = fc->fs_private;
 	struct fs_parse_result result;
 	int opt;
+	int ret;
 
 	opt = fs_parse(fc, btrfs_fs_parameters, param, &result);
 	if (opt < 0)
@@ -598,6 +608,13 @@ static int btrfs_parse_param(struct fs_context *fc,
 			return -EINVAL;
 		}
 		break;
+	case Opt_test_dummy_encryption:
+		btrfs_set_opt(ctx->mount_opt, TEST_DUMMY_ENCRYPTION);
+		ret = fscrypt_parse_test_dummy_encryption(param,
+							  &ctx->dummy_enc_policy);
+		if (ret)
+			return ret;
+		break;
 #endif
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 	case Opt_ref_verify:
@@ -946,6 +963,9 @@ static int btrfs_fill_super(struct super_block *sb,
 		return err;
 	}
 
+	if (fscrypt_is_dummy_policy_set(&fs_info->dummy_enc_policy))
+		btrfs_set_fs_incompat(fs_info, ENCRYPT);
+
 	if (btrfs_fs_incompat(fs_info, ENCRYPT)) {
 		if (IS_ENABLED(CONFIG_FS_ENCRYPTION_INLINE_CRYPT)) {
 			sb->s_flags |= SB_INLINECRYPT;
@@ -1112,6 +1132,9 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 #endif
 	if (btrfs_test_opt(info, REF_VERIFY))
 		seq_puts(seq, ",ref_verify");
+	if (btrfs_test_opt(info, TEST_DUMMY_ENCRYPTION))
+		fscrypt_show_test_dummy_encryption(seq, ',', dentry->d_sb);
+
 	seq_printf(seq, ",subvolid=%llu",
 		  BTRFS_I(d_inode(dentry))->root->root_key.objectid);
 	subvol_name = btrfs_get_subvol_name_from_objectid(info,
@@ -1384,6 +1407,18 @@ static void btrfs_ctx_to_info(struct btrfs_fs_info *fs_info,
 	fs_info->mount_opt = ctx->mount_opt;
 	fs_info->compress_type = ctx->compress_type;
 	fs_info->compress_level = ctx->compress_level;
+
+	/*
+	 * If there's nothing set, or if the fs_info already has one set, don't
+	 * do anything.  If the fs_info is set we'll free the dummy one when we
+	 * free the ctx.
+	 */
+	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
+	    fscrypt_is_dummy_policy_set(&fs_info->dummy_enc_policy))
+		return;
+
+	fs_info->dummy_enc_policy = ctx->dummy_enc_policy;
+	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
 }
 
 static void btrfs_info_to_ctx(struct btrfs_fs_info *fs_info,
@@ -1436,6 +1471,7 @@ static void btrfs_emit_options(struct btrfs_fs_info *info,
 	btrfs_info_if_set(info, old, USEBACKUPROOT, "trying to use backup root at mount time");
 	btrfs_info_if_set(info, old, IGNOREBADROOTS, "ignoring bad roots");
 	btrfs_info_if_set(info, old, IGNOREDATACSUMS, "ignoring data csums");
+	btrfs_info_if_set(info, old, TEST_DUMMY_ENCRYPTION, "test dummy encryption mode enabled");
 
 	btrfs_info_if_unset(info, old, NODATACOW, "setting datacow");
 	btrfs_info_if_unset(info, old, SSD, "not using ssd optimizations");
@@ -1467,6 +1503,23 @@ static void btrfs_emit_options(struct btrfs_fs_info *info,
 			   info->max_inline);
 }
 
+static bool btrfs_check_test_dummy_encryption(struct fs_context *fc)
+{
+	struct btrfs_fs_context *ctx = fc->fs_private;
+	struct btrfs_fs_info *fs_info = btrfs_sb(fc->root->d_sb);
+
+	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
+		return true;
+
+	if (fscrypt_dummy_policies_equal(&fs_info->dummy_enc_policy,
+					 &ctx->dummy_enc_policy))
+		return true;
+
+	btrfs_warn(fs_info,
+		   "Can't set or change test_dummy_encryption on remount");
+	return false;
+}
+
 static int btrfs_reconfigure(struct fs_context *fc)
 {
 	struct super_block *sb = fc->root->d_sb;
@@ -1485,6 +1538,10 @@ static int btrfs_reconfigure(struct fs_context *fc)
 	    !btrfs_check_options(fs_info, &ctx->mount_opt, fc->sb_flags))
 		return -EINVAL;
 
+	if (!mount_reconfigure &&
+	    !btrfs_check_test_dummy_encryption(fc))
+		return -EINVAL;
+
 	ret = btrfs_check_features(fs_info, !(fc->sb_flags & SB_RDONLY));
 	if (ret < 0)
 		return ret;
@@ -2121,6 +2178,7 @@ static void btrfs_free_fs_context(struct fs_context *fc)
 		btrfs_free_fs_info(fs_info);
 
 	if (ctx && refcount_dec_and_test(&ctx->refs)) {
+		fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
 		kfree(ctx->subvol_name);
 		kfree(ctx);
 	}
