Re: [PATCH 06/27] fs: port i_{g,u}id_{needs_}update() to const mnt_idmap

[Jan Kara]

On Tue 01-09-26 14:14:31, Christian Brauner 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>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  include/linux/fs.h                | 8 ++++----
>  security/integrity/evm/evm_main.c | 2 +-
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index cec5de83d882..154f2c976a0a 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1456,7 +1456,7 @@ static inline vfsuid_t i_uid_into_vfsuid(const struct mnt_idmap *idmap,
>   *
>   * Return: true if @inode's i_uid field needs to be updated, false if not.
>   */
> -static inline bool i_uid_needs_update(struct mnt_idmap *idmap,
> +static inline bool i_uid_needs_update(const struct mnt_idmap *idmap,
>  				      const struct iattr *attr,
>  				      const struct inode *inode)
>  {
> @@ -1474,7 +1474,7 @@ static inline bool i_uid_needs_update(struct mnt_idmap *idmap,
>   * Safely update @inode's i_uid field translating the vfsuid of any idmapped
>   * mount into the filesystem kuid.
>   */
> -static inline void i_uid_update(struct mnt_idmap *idmap,
> +static inline void i_uid_update(const struct mnt_idmap *idmap,
>  				const struct iattr *attr,
>  				struct inode *inode)
>  {
> @@ -1508,7 +1508,7 @@ static inline vfsgid_t i_gid_into_vfsgid(const struct mnt_idmap *idmap,
>   *
>   * Return: true if @inode's i_gid field needs to be updated, false if not.
>   */
> -static inline bool i_gid_needs_update(struct mnt_idmap *idmap,
> +static inline bool i_gid_needs_update(const struct mnt_idmap *idmap,
>  				      const struct iattr *attr,
>  				      const struct inode *inode)
>  {
> @@ -1526,7 +1526,7 @@ static inline bool i_gid_needs_update(struct mnt_idmap *idmap,
>   * Safely update @inode's i_gid field translating the vfsgid of any idmapped
>   * mount into the filesystem kgid.
>   */
> -static inline void i_gid_update(struct mnt_idmap *idmap,
> +static inline void i_gid_update(const struct mnt_idmap *idmap,
>  				const struct iattr *attr,
>  				struct inode *inode)
>  {
> diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
> index 66f27653cdac..06e187c9912d 100644
> --- a/security/integrity/evm/evm_main.c
> +++ b/security/integrity/evm/evm_main.c
> @@ -933,7 +933,7 @@ static inline void evm_inode_post_remove_acl(struct mnt_idmap *idmap,
>  	evm_inode_post_removexattr(dentry, acl_name);
>  }
>  
> -static int evm_attr_change(struct mnt_idmap *idmap,
> +static int evm_attr_change(const struct mnt_idmap *idmap,
>  			   struct dentry *dentry, struct iattr *attr)
>  {
>  	struct inode *inode = d_backing_inode(dentry);
> 
> -- 
> 2.53.0
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR