[PATCH v4 13/46] btrfs: add new FEATURE_INCOMPAT_ENCRYPT flag

Josef Bacik
2023-12-01T22:12:13Z

From: Omar Sandoval <osandov@osandov.com>

As encrypted files will be incompatible with older filesystem versions,
new filesystems should be created with an incompat flag for fscrypt,
which will gate access to the encryption ioctls.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/fs.h | 3 ++-
fs/btrfs/super.c | 5 +++++
fs/btrfs/sysfs.c | 6 ++++++
include/uapi/linux/btrfs.h | 1 +
4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/fs.h b/fs/btrfs/fs.h
index f8bb73d6ab68..1340e71d026c 100644
--- a/fs/btrfs/fs.h
+++ b/fs/btrfs/fs.h
@@ -232,7 +232,8 @@ enum {
#define BTRFS_FEATURE_INCOMPAT_SUPP \
(BTRFS_FEATURE_INCOMPAT_SUPP_STABLE | \
BTRFS_FEATURE_INCOMPAT_RAID_STRIPE_TREE | \
- BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2)
+ BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2 | \
+ BTRFS_FEATURE_INCOMPAT_ENCRYPT)

#else

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4b92d6ffde5e..39a338e92115 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2445,6 +2445,11 @@ static int __init btrfs_print_mod_info(void)
", fsverity=yes"
#else
", fsverity=no"
+#endif
+#ifdef CONFIG_FS_ENCRYPTION
+ ", fscrypt=yes"
+#else
+ ", fscrypt=no"
#endif
;
pr_info("Btrfs loaded%s\n", options);
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index e6b51fb3ddc1..4ece703d9d5f 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -304,6 +304,9 @@ BTRFS_FEAT_ATTR_INCOMPAT(raid_stripe_tree, RAID_STRIPE_TREE);
#ifdef CONFIG_FS_VERITY
BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
#endif
+#ifdef CONFIG_FS_ENCRYPTION
+BTRFS_FEAT_ATTR_INCOMPAT(encryption, ENCRYPT);
+#endif /* CONFIG_FS_ENCRYPTION */

/*
* Features which depend on feature bits and may differ between each fs.
@@ -336,6 +339,9 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
#ifdef CONFIG_FS_VERITY
BTRFS_FEAT_ATTR_PTR(verity),
#endif
+#ifdef CONFIG_FS_ENCRYPTION
+ BTRFS_FEAT_ATTR_PTR(encryption),
+#endif /* CONFIG_FS_ENCRYPTION */
NULL
};

diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 7c29d82db9ee..6a0f4c0e4096 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -334,6 +334,7 @@ struct btrfs_ioctl_fs_info_args {
#define BTRFS_FEATURE_INCOMPAT_ZONED (1ULL << 12)
#define BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2 (1ULL << 13)
#define BTRFS_FEATURE_INCOMPAT_RAID_STRIPE_TREE (1ULL << 14)
+#define BTRFS_FEATURE_INCOMPAT_ENCRYPT (1ULL << 15)
#define BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA (1ULL << 16)

struct btrfs_ioctl_feature_flags {
--
2.41.0