Switch posix_acls() to lookup fsids in the fsid mappings. If no fsid mappings are setup the behavior is unchanged, i.e. fsids are looked up in the id mappings. Afaict, all filesystems that share a superblock in all user namespaces currently do not support acls so this change should be safe to do unconditionally. Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx> --- /* v2 */ unchanged --- fs/posix_acl.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/fs/posix_acl.c b/fs/posix_acl.c index 249672bf54fe..763bba24f380 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -22,6 +22,7 @@ #include <linux/xattr.h> #include <linux/export.h> #include <linux/user_namespace.h> +#include <linux/fsuidgid.h> static struct posix_acl **acl_by_type(struct inode *inode, int type) { @@ -692,12 +693,12 @@ static void posix_acl_fix_xattr_userns( for (end = entry + count; entry != end; entry++) { switch(le16_to_cpu(entry->e_tag)) { case ACL_USER: - uid = make_kuid(from, le32_to_cpu(entry->e_id)); - entry->e_id = cpu_to_le32(from_kuid(to, uid)); + uid = make_kfsuid(from, le32_to_cpu(entry->e_id)); + entry->e_id = cpu_to_le32(from_kfsuid(to, uid)); break; case ACL_GROUP: - gid = make_kgid(from, le32_to_cpu(entry->e_id)); - entry->e_id = cpu_to_le32(from_kgid(to, gid)); + gid = make_kfsgid(from, le32_to_cpu(entry->e_id)); + entry->e_id = cpu_to_le32(from_kfsgid(to, gid)); break; default: break; @@ -746,12 +747,12 @@ posix_acl_from_xattr(struct user_namespace *user_ns, return ERR_PTR(-EINVAL); if (count == 0) return NULL; - + acl = posix_acl_alloc(count, GFP_NOFS); if (!acl) return ERR_PTR(-ENOMEM); acl_e = acl->a_entries; - + for (end = entry + count; entry != end; acl_e++, entry++) { acl_e->e_tag = le16_to_cpu(entry->e_tag); acl_e->e_perm = le16_to_cpu(entry->e_perm); @@ -765,14 +766,14 @@ posix_acl_from_xattr(struct user_namespace *user_ns, case ACL_USER: acl_e->e_uid = - make_kuid(user_ns, + make_kfsuid(user_ns, le32_to_cpu(entry->e_id)); if (!uid_valid(acl_e->e_uid)) goto fail; break; case ACL_GROUP: acl_e->e_gid = - make_kgid(user_ns, + make_kfsgid(user_ns, le32_to_cpu(entry->e_id)); if (!gid_valid(acl_e->e_gid)) goto fail; @@ -817,11 +818,11 @@ posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl, switch(acl_e->e_tag) { case ACL_USER: ext_entry->e_id = - cpu_to_le32(from_kuid(user_ns, acl_e->e_uid)); + cpu_to_le32(from_kfsuid(user_ns, acl_e->e_uid)); break; case ACL_GROUP: ext_entry->e_id = - cpu_to_le32(from_kgid(user_ns, acl_e->e_gid)); + cpu_to_le32(from_kfsgid(user_ns, acl_e->e_gid)); break; default: ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); -- 2.25.0