Merge tag 'vfs-7.4-rc1.idmap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs idmap constification from Christian Brauner:
 "This makes struct mnt_idmap const throughout the tree.

  A mount's idmapping is immutable. The only thing modified after
  alloc_mnt_idmap() is the reference count and that is hidden behind
  mnt_idmap_get() and mnt_idmap_put(). Everything else only reads from
  it. That is the same model struct cred uses and the idmapping is
  sensitive enough to deserve it.

  The conversion goes bottom up through the vfs{g,u}id and fs{g,u}id
  helpers, the privilege checks, acl, xattr and quota and then every
  inode operation that takes an idmap, so ->permission(), ->getattr(),
  ->setattr(), ->create(), ->mkdir(), ->mknod(), ->symlink(),
  ->rename(), ->tmpfile(), ->get_acl(), ->set_acl() and ->fileattr_set()
  with their implementations in every filesystem, plus the LSM hooks.

  struct vfsmount, struct mount_kattr and struct kstatmount store a
  const pointer and nop_mnt_idmap and invalid_mnt_idmap live in rodata,
  so anything that tries to modify them faults instead of silently
  corrupting the initial idmapping"

* tag 'vfs-7.4-rc1.idmap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits)
  fs: make nop_mnt_idmap and invalid_mnt_idmap const
  fs: port mnt_idmap() and file_mnt_idmap() to const mnt_idmap
  fs: port vfs_*() helpers to const mnt_idmap
  fs: port ->setattr() to pass const mnt_idmap
  fs: port ->getattr() to pass const mnt_idmap
  fs: port ->create() to pass const mnt_idmap
  fs: port ->symlink() to pass const mnt_idmap
  fs: port ->mkdir() to pass const mnt_idmap
  fs: port ->rename() to pass const mnt_idmap
  fs: port ->mknod() to pass const mnt_idmap
  fs: port ->tmpfile() to pass const mnt_idmap
  fs: port ->get_acl() to pass const mnt_idmap
  fs: port ->set_acl() to pass const mnt_idmap
  fs: port ->fileattr_set() to pass const mnt_idmap
  fs: port xattr to const mnt_idmap
  fs: port ->permission() to pass const mnt_idmap
  fs: port acl to const mnt_idmap
  fs: port inode_init_owner() to const mnt_idmap
  fs: port inode_owner_or_capable() to const mnt_idmap
  fs: port privilege checking helpers to const mnt_idmap
  ...

3 files changed, 19 insertions, 19 deletions

diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 7837968c0842..c6f328e4752e 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -176,7 +176,7 @@ static void bpf_dentry_finalize(struct dentry *dentry, struct inode *inode,
 	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 }
 
-static struct dentry *bpf_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+static struct dentry *bpf_mkdir(const struct mnt_idmap *idmap, struct inode *dir,
 				struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;
@@ -424,7 +424,7 @@ bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags)
 	return simple_lookup(dir, dentry, flags);
 }
 
-static int bpf_symlink(struct mnt_idmap *idmap, struct inode *dir,
+static int bpf_symlink(const struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, const char *target)
 {
 	struct inode *inode;
@@ -874,7 +874,7 @@ enum {
 };
 
 static int bpf_fs_xattr_set(const struct xattr_handler *handler,
-			    struct mnt_idmap *idmap, struct dentry *unused,
+			    const struct mnt_idmap *idmap, struct dentry *unused,
 			    struct inode *inode, const char *name,
 			    const void *value, size_t size, int flags)
 {
diff --git a/kernel/capability.c b/kernel/capability.c
index 90e6ab62f6db..a689dae590ff 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -470,7 +470,7 @@ EXPORT_SYMBOL(file_ns_capable);
  * Return true if the inode uid and gid are within the namespace.
  */
 bool privileged_wrt_inode_uidgid(struct user_namespace *ns,
-				 struct mnt_idmap *idmap,
+				 const struct mnt_idmap *idmap,
 				 const struct inode *inode)
 {
 	return vfsuid_has_mapping(ns, i_uid_into_vfsuid(idmap, inode)) &&
@@ -487,7 +487,7 @@ bool privileged_wrt_inode_uidgid(struct user_namespace *ns,
  * its own user namespace and that the given inode's uid and gid are
  * mapped into the current user namespace.
  */
-bool capable_wrt_inode_uidgid(struct mnt_idmap *idmap,
+bool capable_wrt_inode_uidgid(const struct mnt_idmap *idmap,
 			      const struct inode *inode, int cap)
 {
 	struct user_namespace *ns = current_user_ns();
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index c3f4e1f28810..50c374ed4687 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -276,8 +276,8 @@ static int cmp_map_id(const void *k, const void *e)
  * map_id_range_down_max - Find idmap via binary search in ordered idmap array.
  * Can only be called if number of mappings exceeds UID_GID_MAP_MAX_BASE_EXTENTS.
  */
-static struct uid_gid_extent *
-map_id_range_down_max(unsigned extents, struct uid_gid_map *map, u32 id, u32 count)
+static const struct uid_gid_extent *
+map_id_range_down_max(unsigned extents, const struct uid_gid_map *map, u32 id, u32 count)
 {
 	struct idmap_key key;
 
@@ -294,8 +294,8 @@ map_id_range_down_max(unsigned extents, struct uid_gid_map *map, u32 id, u32 cou
  * Can only be called if number of mappings is equal or less than
  * UID_GID_MAP_MAX_BASE_EXTENTS.
  */
-static struct uid_gid_extent *
-map_id_range_down_base(unsigned extents, struct uid_gid_map *map, u32 id, u32 count)
+static const struct uid_gid_extent *
+map_id_range_down_base(unsigned extents, const struct uid_gid_map *map, u32 id, u32 count)
 {
 	unsigned idx;
 	u32 first, last, id2;
@@ -313,9 +313,9 @@ map_id_range_down_base(unsigned extents, struct uid_gid_map *map, u32 id, u32 co
 	return NULL;
 }
 
-static u32 map_id_range_down(struct uid_gid_map *map, u32 id, u32 count)
+static u32 map_id_range_down(const struct uid_gid_map *map, u32 id, u32 count)
 {
-	struct uid_gid_extent *extent;
+	const struct uid_gid_extent *extent;
 	unsigned extents = map->nr_extents;
 	smp_rmb();
 
@@ -333,7 +333,7 @@ static u32 map_id_range_down(struct uid_gid_map *map, u32 id, u32 count)
 	return id;
 }
 
-u32 map_id_down(struct uid_gid_map *map, u32 id)
+u32 map_id_down(const struct uid_gid_map *map, u32 id)
 {
 	return map_id_range_down(map, id, 1);
 }
@@ -343,8 +343,8 @@ u32 map_id_down(struct uid_gid_map *map, u32 id)
  * Can only be called if number of mappings is equal or less than
  * UID_GID_MAP_MAX_BASE_EXTENTS.
  */
-static struct uid_gid_extent *
-map_id_range_up_base(unsigned extents, struct uid_gid_map *map, u32 id, u32 count)
+static const struct uid_gid_extent *
+map_id_range_up_base(unsigned extents, const struct uid_gid_map *map, u32 id, u32 count)
 {
 	unsigned idx;
 	u32 first, last, id2;
@@ -366,8 +366,8 @@ map_id_range_up_base(unsigned extents, struct uid_gid_map *map, u32 id, u32 coun
  * map_id_up_max - Find idmap via binary search in ordered idmap array.
  * Can only be called if number of mappings exceeds UID_GID_MAP_MAX_BASE_EXTENTS.
  */
-static struct uid_gid_extent *
-map_id_range_up_max(unsigned extents, struct uid_gid_map *map, u32 id, u32 count)
+static const struct uid_gid_extent *
+map_id_range_up_max(unsigned extents, const struct uid_gid_map *map, u32 id, u32 count)
 {
 	struct idmap_key key;
 
@@ -379,9 +379,9 @@ map_id_range_up_max(unsigned extents, struct uid_gid_map *map, u32 id, u32 count
 		       sizeof(struct uid_gid_extent), cmp_map_id);
 }
 
-u32 map_id_range_up(struct uid_gid_map *map, u32 id, u32 count)
+u32 map_id_range_up(const struct uid_gid_map *map, u32 id, u32 count)
 {
-	struct uid_gid_extent *extent;
+	const struct uid_gid_extent *extent;
 	unsigned extents = map->nr_extents;
 	smp_rmb();
 
@@ -399,7 +399,7 @@ u32 map_id_range_up(struct uid_gid_map *map, u32 id, u32 count)
 	return id;
 }
 
-u32 map_id_up(struct uid_gid_map *map, u32 id)
+u32 map_id_up(const struct uid_gid_map *map, u32 id)
 {
 	return map_id_range_up(map, id, 1);
 }