diff options
Diffstat (limited to 'fs/overlayfs/overlayfs.h')
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index d6405c2046ed..bc81f279b170 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -122,6 +122,35 @@ static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) return ovl_xattr_table[ox][ofs->config.userxattr]; } +/* + * When changing ownership of an upper object map the intended ownership + * according to the upper layer's idmapping. When an upper mount idmaps files + * that are stored on-disk as owned by id 1001 to id 1000 this means stat on + * this object will report it as being owned by id 1000 when calling stat via + * the upper mount. + * In order to change ownership of an object so stat reports id 1000 when + * called on an idmapped upper mount the value written to disk - i.e., the + * value stored in ia_*id - must 1001. The mount mapping helper will thus take + * care to map 1000 to 1001. + * The mnt idmapping helpers are nops if the upper layer isn't idmapped. + */ +static inline int ovl_do_notify_change(struct ovl_fs *ofs, + struct dentry *upperdentry, + struct iattr *attr) +{ + struct user_namespace *upper_mnt_userns = ovl_upper_mnt_userns(ofs); + struct user_namespace *fs_userns = i_user_ns(d_inode(upperdentry)); + + if (attr->ia_valid & ATTR_UID) + attr->ia_uid = mapped_kuid_user(upper_mnt_userns, + fs_userns, attr->ia_uid); + if (attr->ia_valid & ATTR_GID) + attr->ia_gid = mapped_kgid_user(upper_mnt_userns, + fs_userns, attr->ia_gid); + + return notify_change(upper_mnt_userns, upperdentry, attr, NULL); +} + static inline int ovl_do_rmdir(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry) { |