From 1bd66c1a32ca8e5148eaba2675321637e89a49af Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Sat, 20 Mar 2021 13:26:21 +0100 Subject: [PATCH] fs: document mapping helpers Document new helpers we introduced this cycle. Link: https://lore.kernel.org/r/20210320122623.599086-2-christian.brauner@ubuntu.com Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner --- include/linux/fs.h | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/include/linux/fs.h b/include/linux/fs.h index ec8f3dd..3387353 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1574,36 +1574,84 @@ static inline void i_gid_write(struct inode *inode, gid_t gid) inode->i_gid = make_kgid(inode->i_sb->s_user_ns, gid); } +/** + * kuid_into_mnt - map a kuid down into a mnt_userns + * @mnt_userns: user namespace of the relevant mount + * @kuid: kuid to be mapped + * + * Return: @kuid mapped according to @mnt_userns. + * If @kuid has no mapping INVALID_UID is returned. + */ static inline kuid_t kuid_into_mnt(struct user_namespace *mnt_userns, kuid_t kuid) { return make_kuid(mnt_userns, __kuid_val(kuid)); } +/** + * kgid_into_mnt - map a kgid down into a mnt_userns + * @mnt_userns: user namespace of the relevant mount + * @kgid: kgid to be mapped + * + * Return: @kgid mapped according to @mnt_userns. + * If @kgid has no mapping INVALID_GID is returned. + */ static inline kgid_t kgid_into_mnt(struct user_namespace *mnt_userns, kgid_t kgid) { return make_kgid(mnt_userns, __kgid_val(kgid)); } +/** + * i_uid_into_mnt - map an inode's i_uid down into a mnt_userns + * @mnt_userns: user namespace of the mount the inode was found from + * @inode: inode to map + * + * Return: the inode's i_uid mapped down according to @mnt_userns. + * If the inode's i_uid has no mapping INVALID_UID is returned. + */ static inline kuid_t i_uid_into_mnt(struct user_namespace *mnt_userns, const struct inode *inode) { return kuid_into_mnt(mnt_userns, inode->i_uid); } +/** + * i_gid_into_mnt - map an inode's i_gid down into a mnt_userns + * @mnt_userns: user namespace of the mount the inode was found from + * @inode: inode to map + * + * Return: the inode's i_gid mapped down according to @mnt_userns. + * If the inode's i_gid has no mapping INVALID_GID is returned. + */ static inline kgid_t i_gid_into_mnt(struct user_namespace *mnt_userns, const struct inode *inode) { return kgid_into_mnt(mnt_userns, inode->i_gid); } +/** + * kuid_from_mnt - map a kuid up into a mnt_userns + * @mnt_userns: user namespace of the relevant mount + * @kuid: kuid to be mapped + * + * Return: @kuid mapped up according to @mnt_userns. + * If @kuid has no mapping INVALID_UID is returned. + */ static inline kuid_t kuid_from_mnt(struct user_namespace *mnt_userns, kuid_t kuid) { return KUIDT_INIT(from_kuid(mnt_userns, kuid)); } +/** + * kgid_from_mnt - map a kgid up into a mnt_userns + * @mnt_userns: user namespace of the relevant mount + * @kgid: kgid to be mapped + * + * Return: @kgid mapped up according to @mnt_userns. + * If @kgid has no mapping INVALID_GID is returned. + */ static inline kgid_t kgid_from_mnt(struct user_namespace *mnt_userns, kgid_t kgid) { -- 2.7.4