On Wed, May 13, 2026 at 10:52:46AM +0200, Daniel Vacek wrote: > From: Omar Sandoval <[email protected]> > > 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 <[email protected]> > Signed-off-by: Sweet Tea Dorminy <[email protected]> > Signed-off-by: Josef Bacik <[email protected]> > Signed-off-by: Daniel Vacek <[email protected]> > --- > > v5: > https://lore.kernel.org/linux-btrfs/ccbea52046c1dadbbef926bfc878cc23af952729.1706116485.git.jo...@toxicpanda.com/ > * No changes since. > --- > 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 a4758d94b32e..dbdb73722c14 100644 > --- a/fs/btrfs/fs.h > +++ b/fs/btrfs/fs.h > @@ -322,7 +322,8 @@ enum { > (BTRFS_FEATURE_INCOMPAT_SUPP_STABLE | \ > BTRFS_FEATURE_INCOMPAT_RAID_STRIPE_TREE | \ > BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2 | \ > - BTRFS_FEATURE_INCOMPAT_REMAP_TREE) > + BTRFS_FEATURE_INCOMPAT_REMAP_TREE | \ > + BTRFS_FEATURE_INCOMPAT_ENCRYPT) > > #else > > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c > index efaa0788c1fc..84df97363611 100644 > --- a/fs/btrfs/super.c > +++ b/fs/btrfs/super.c > @@ -2563,6 +2563,11 @@ static int __init btrfs_print_mod_info(void) > ", fsverity=yes" > #else > ", fsverity=no" > +#endif > +#ifdef CONFIG_FS_ENCRYPTION > + ", fscrypt=yes" > +#else > + ", fscrypt=no" > #endif > ; > > diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c > index 0d14570c8bc2..3fe57843f902 100644 > --- a/fs/btrfs/sysfs.c > +++ b/fs/btrfs/sysfs.c > @@ -305,6 +305,9 @@ BTRFS_FEAT_ATTR_INCOMPAT(remap_tree, REMAP_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. > @@ -338,6 +341,9 @@ 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 9165154a274d..2f6a46e5f4ce 100644 > --- a/include/uapi/linux/btrfs.h > +++ b/include/uapi/linux/btrfs.h > @@ -335,6 +335,7 @@ 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) > #define BTRFS_FEATURE_INCOMPAT_REMAP_TREE (1ULL << 17)
There seems to be an inconsistency where btrfs's fscrypt support depends on CONFIG_BTRFS_EXPERIMENTAL, but the support is advertised in sysfs regardless. - Eric
