Re: [PATCH 13/27] fs: port xattr to const mnt_idmap

[Paul Moore]

On Sep  1, 2026 Christian Brauner <brauner@xxxxxxxxxx> wrote:
> 
> Convert to const struct mnt_idmap.
> 
> A mount's idmapping is immutable. The only thing that is allowed to be
> modified afterwards is the reference count and that is hidden behind
> mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
> from the idmapping. This is the same model that struct cred uses and the
> idmapping is also rather sensitive.
> 
> So make the idmap argument const wherever we can. The conversion is done
> from the bottom up so callers can continue to pass a non-const pointer
> to a const parameter until the conversion is finished.
> 
> No functional changes.
> 
> Signed-off-by: Christian Brauner (Amutable) <brauner@xxxxxxxxxx>
> Reviewed-by: Jan Kara <jack@xxxxxxx>
> ---
>  Documentation/filesystems/locking.rst |  2 +-
>  fs/9p/xattr.c                         |  2 +-
>  fs/afs/xattr.c                        |  4 ++--
>  fs/attr.c                             |  2 +-
>  fs/btrfs/xattr.c                      |  6 +++---
>  fs/ceph/xattr.c                       |  2 +-
>  fs/ecryptfs/inode.c                   |  2 +-
>  fs/ext2/xattr_security.c              |  2 +-
>  fs/ext2/xattr_trusted.c               |  2 +-
>  fs/ext2/xattr_user.c                  |  2 +-
>  fs/ext4/xattr_hurd.c                  |  2 +-
>  fs/ext4/xattr_security.c              |  2 +-
>  fs/ext4/xattr_trusted.c               |  2 +-
>  fs/ext4/xattr_user.c                  |  2 +-
>  fs/f2fs/xattr.c                       |  4 ++--
>  fs/fuse/dir.c                         |  2 +-
>  fs/fuse/fuse_i.h                      |  2 +-
>  fs/fuse/xattr.c                       |  2 +-
>  fs/gfs2/xattr.c                       |  2 +-
>  fs/hfs/attr.c                         |  2 +-
>  fs/hfsplus/xattr.c                    |  2 +-
>  fs/hfsplus/xattr_security.c           |  2 +-
>  fs/hfsplus/xattr_trusted.c            |  2 +-
>  fs/hfsplus/xattr_user.c               |  2 +-
>  fs/jffs2/security.c                   |  2 +-
>  fs/jffs2/xattr_trusted.c              |  2 +-
>  fs/jffs2/xattr_user.c                 |  2 +-
>  fs/jfs/xattr.c                        |  4 ++--
>  fs/kernfs/inode.c                     |  4 ++--
>  fs/nfs/nfs4proc.c                     | 10 +++++-----
>  fs/ntfs/ea.c                          |  2 +-
>  fs/ntfs3/xattr.c                      |  2 +-
>  fs/ocfs2/xattr.c                      |  6 +++---
>  fs/orangefs/xattr.c                   |  2 +-
>  fs/overlayfs/xattrs.c                 |  4 ++--
>  fs/pidfs.c                            |  2 +-
>  fs/smb/client/xattr.c                 |  2 +-
>  fs/smb/server/vfs.c                   | 24 ++++++++++++------------
>  fs/smb/server/vfs.h                   | 20 ++++++++++----------
>  fs/ubifs/xattr.c                      |  2 +-
>  fs/xattr.c                            | 22 +++++++++++-----------
>  fs/xfs/xfs_iops.c                     |  2 +-
>  fs/xfs/xfs_xattr.c                    |  2 +-
>  include/linux/capability.h            |  4 ++--
>  include/linux/fs.h                    |  2 +-
>  include/linux/lsm_hook_defs.h         |  8 ++++----
>  include/linux/security.h              | 20 ++++++++++----------
>  include/linux/xattr.h                 | 20 ++++++++++----------
>  kernel/bpf/inode.c                    |  2 +-
>  mm/shmem.c                            |  2 +-
>  net/socket.c                          |  4 ++--
>  security/commoncap.c                  |  8 ++++----
>  security/integrity/evm/evm_main.c     |  4 ++--
>  security/integrity/ima/ima_appraise.c |  4 ++--
>  security/security.c                   |  8 ++++----
>  security/selinux/hooks.c              |  6 +++---
>  security/smack/smack_lsm.c            |  6 +++---
>  57 files changed, 135 insertions(+), 135 deletions(-)

Acked-by: Paul Moore <paul@xxxxxxxxxxxxxx> (LSM, SELinux)

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