Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull vfs idmapping updates from Christian Brauner:

 - Last cycle we introduced the dedicated struct mnt_idmap type for
   mount idmapping and the required infrastucture in 256c8aed2b42 ("fs:
   introduce dedicated idmap type for mounts"). As promised in last
   cycle's pull request message this converts everything to rely on
   struct mnt_idmap.

   Currently we still pass around the plain namespace that was attached
   to a mount. This is in general pretty convenient but it makes it easy
   to conflate namespaces that are relevant on the filesystem with
   namespaces that are relevant on the mount level. Especially for
   non-vfs developers without detailed knowledge in this area this was a
   potential source for bugs.

   This finishes the conversion. Instead of passing the plain namespace
   around this updates all places that currently take a pointer to a
   mnt_userns with a pointer to struct mnt_idmap.

   Now that the conversion is done all helpers down to the really
   low-level helpers only accept a struct mnt_idmap argument instead of
   two namespace arguments.

   Conflating mount and other idmappings will now cause the compiler to
   complain loudly thus eliminating the possibility of any bugs. This
   makes it impossible for filesystem developers to mix up mount and
   filesystem idmappings as they are two distinct types and require
   distinct helpers that cannot be used interchangeably.

   Everything associated with struct mnt_idmap is moved into a single
   separate file. With that change no code can poke around in struct
   mnt_idmap. It can only be interacted with through dedicated helpers.
   That means all filesystems are and all of the vfs is completely
   oblivious to the actual implementation of idmappings.

   We are now also able to extend struct mnt_idmap as we see fit. For
   example, we can decouple it completely from namespaces for users that
   don't require or don't want to use them at all. We can also extend
   the concept of idmappings so we can cover filesystem specific
   requirements.

   In combination with the vfs{g,u}id_t work we finished in v6.2 this
   makes this feature substantially more robust and thus difficult to
   implement wrong by a given filesystem and also protects the vfs.

 - Enable idmapped mounts for tmpfs and fulfill a longstanding request.

   A long-standing request from users had been to make it possible to
   create idmapped mounts for tmpfs. For example, to share the host's
   tmpfs mount between multiple sandboxes. This is a prerequisite for
   some advanced Kubernetes cases. Systemd also has a range of use-cases
   to increase service isolation. And there are more users of this.

   However, with all of the other work going on this was way down on the
   priority list but luckily someone other than ourselves picked this
   up.

   As usual the patch is tiny as all the infrastructure work had been
   done multiple kernel releases ago. In addition to all the tests that
   we already have I requested that Rodrigo add a dedicated tmpfs
   testsuite for idmapped mounts to xfstests. It is to be included into
   xfstests during the v6.3 development cycle. This should add a slew of
   additional tests.

* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
  shmem: support idmapped mounts for tmpfs
  fs: move mnt_idmap
  fs: port vfs{g,u}id helpers to mnt_idmap
  fs: port fs{g,u}id helpers to mnt_idmap
  fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
  fs: port i_{g,u}id_{needs_}update() to mnt_idmap
  quota: port to mnt_idmap
  fs: port privilege checking helpers to mnt_idmap
  fs: port inode_owner_or_capable() to mnt_idmap
  fs: port inode_init_owner() to mnt_idmap
  fs: port acl to mnt_idmap
  fs: port xattr to mnt_idmap
  fs: port ->permission() to pass mnt_idmap
  fs: port ->fileattr_set() to pass mnt_idmap
  fs: port ->set_acl() to pass mnt_idmap
  fs: port ->get_acl() to pass mnt_idmap
  fs: port ->tmpfile() to pass mnt_idmap
  fs: port ->rename() to pass mnt_idmap
  fs: port ->mknod() to pass mnt_idmap
  fs: port ->mkdir() to pass mnt_idmap
  ...

8 files changed, 26 insertions, 26 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index bbf58c2439da..9a2d390bd06f 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -1674,7 +1674,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 	return rc;
 }
 
-struct posix_acl *cifs_get_acl(struct user_namespace *mnt_userns,
+struct posix_acl *cifs_get_acl(struct mnt_idmap *idmap,
 			       struct dentry *dentry, int type)
 {
 #if defined(CONFIG_CIFS_ALLOW_INSECURE_LEGACY) && defined(CONFIG_CIFS_POSIX)
@@ -1738,7 +1738,7 @@ out:
 #endif
 }
 
-int cifs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int cifs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
 #if defined(CONFIG_CIFS_ALLOW_INSECURE_LEGACY) && defined(CONFIG_CIFS_POSIX)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index f052f190b2e8..cb7c5460a80b 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -346,7 +346,7 @@ static long cifs_fallocate(struct file *file, int mode, loff_t off, loff_t len)
 	return -EOPNOTSUPP;
 }
 
-static int cifs_permission(struct user_namespace *mnt_userns,
+static int cifs_permission(struct mnt_idmap *idmap,
 			   struct inode *inode, int mask)
 {
 	struct cifs_sb_info *cifs_sb;
@@ -362,7 +362,7 @@ static int cifs_permission(struct user_namespace *mnt_userns,
 		on the client (above and beyond ACL on servers) for
 		servers which do not support setting and viewing mode bits,
 		so allowing client to check permissions is useful */
-		return generic_permission(&init_user_ns, inode, mask);
+		return generic_permission(&nop_mnt_idmap, inode, mask);
 }
 
 static struct kmem_cache *cifs_inode_cachep;
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 63a0ac2b9355..b58cd737b21e 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -49,7 +49,7 @@ extern void cifs_sb_deactive(struct super_block *sb);
 /* Functions related to inodes */
 extern const struct inode_operations cifs_dir_inode_ops;
 extern struct inode *cifs_root_iget(struct super_block *);
-extern int cifs_create(struct user_namespace *, struct inode *,
+extern int cifs_create(struct mnt_idmap *, struct inode *,
 		       struct dentry *, umode_t, bool excl);
 extern int cifs_atomic_open(struct inode *, struct dentry *,
 			    struct file *, unsigned, umode_t);
@@ -57,12 +57,12 @@ extern struct dentry *cifs_lookup(struct inode *, struct dentry *,
 				  unsigned int);
 extern int cifs_unlink(struct inode *dir, struct dentry *dentry);
 extern int cifs_hardlink(struct dentry *, struct inode *, struct dentry *);
-extern int cifs_mknod(struct user_namespace *, struct inode *, struct dentry *,
+extern int cifs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
 		      umode_t, dev_t);
-extern int cifs_mkdir(struct user_namespace *, struct inode *, struct dentry *,
+extern int cifs_mkdir(struct mnt_idmap *, struct inode *, struct dentry *,
 		      umode_t);
 extern int cifs_rmdir(struct inode *, struct dentry *);
-extern int cifs_rename2(struct user_namespace *, struct inode *,
+extern int cifs_rename2(struct mnt_idmap *, struct inode *,
 			struct dentry *, struct inode *, struct dentry *,
 			unsigned int);
 extern int cifs_revalidate_file_attr(struct file *filp);
@@ -72,9 +72,9 @@ extern int cifs_revalidate_dentry(struct dentry *);
 extern int cifs_invalidate_mapping(struct inode *inode);
 extern int cifs_revalidate_mapping(struct inode *inode);
 extern int cifs_zap_mapping(struct inode *inode);
-extern int cifs_getattr(struct user_namespace *, const struct path *,
+extern int cifs_getattr(struct mnt_idmap *, const struct path *,
 			struct kstat *, u32, unsigned int);
-extern int cifs_setattr(struct user_namespace *, struct dentry *,
+extern int cifs_setattr(struct mnt_idmap *, struct dentry *,
 			struct iattr *);
 extern int cifs_fiemap(struct inode *, struct fiemap_extent_info *, u64 start,
 		       u64 len);
@@ -124,7 +124,7 @@ extern struct vfsmount *cifs_dfs_d_automount(struct path *path);
 /* Functions related to symlinks */
 extern const char *cifs_get_link(struct dentry *, struct inode *,
 			struct delayed_call *);
-extern int cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
+extern int cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
 			struct dentry *direntry, const char *symname);
 
 #ifdef CONFIG_CIFS_XATTR
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 1207b39686fb..b8a47704a6ef 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -225,9 +225,9 @@ extern struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *, struct inode *,
 				      const char *, u32 *, u32);
 extern struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *,
 				const struct cifs_fid *, u32 *, u32);
-extern struct posix_acl *cifs_get_acl(struct user_namespace *mnt_userns,
+extern struct posix_acl *cifs_get_acl(struct mnt_idmap *idmap,
 				      struct dentry *dentry, int type);
-extern int cifs_set_acl(struct user_namespace *mnt_userns,
+extern int cifs_set_acl(struct mnt_idmap *idmap,
 			struct dentry *dentry, struct posix_acl *acl, int type);
 extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
 				const char *, int);
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index ad4208bf1e32..2b6076324ffc 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -529,7 +529,7 @@ out_free_xid:
 	return rc;
 }
 
-int cifs_create(struct user_namespace *mnt_userns, struct inode *inode,
+int cifs_create(struct mnt_idmap *idmap, struct inode *inode,
 		struct dentry *direntry, umode_t mode, bool excl)
 {
 	int rc;
@@ -579,7 +579,7 @@ out_free_xid:
 	return rc;
 }
 
-int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
+int cifs_mknod(struct mnt_idmap *idmap, struct inode *inode,
 	       struct dentry *direntry, umode_t mode, dev_t device_number)
 {
 	int rc = -EPERM;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index f145a59af89b..11cdc7cfe0ba 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1910,7 +1910,7 @@ posix_mkdir_get_info:
 }
 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 
-int cifs_mkdir(struct user_namespace *mnt_userns, struct inode *inode,
+int cifs_mkdir(struct mnt_idmap *idmap, struct inode *inode,
 	       struct dentry *direntry, umode_t mode)
 {
 	int rc = 0;
@@ -2138,7 +2138,7 @@ do_rename_exit:
 }
 
 int
-cifs_rename2(struct user_namespace *mnt_userns, struct inode *source_dir,
+cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
 	     struct dentry *source_dentry, struct inode *target_dir,
 	     struct dentry *target_dentry, unsigned int flags)
 {
@@ -2496,7 +2496,7 @@ int cifs_revalidate_dentry(struct dentry *dentry)
 	return cifs_revalidate_mapping(inode);
 }
 
-int cifs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int cifs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct dentry *dentry = path->dentry;
@@ -2537,7 +2537,7 @@ int cifs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 			return rc;
 	}
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	stat->blksize = cifs_sb->ctx->bsize;
 	stat->ino = CIFS_I(inode)->uniqueid;
 
@@ -2752,7 +2752,7 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM)
 		attrs->ia_valid |= ATTR_FORCE;
 
-	rc = setattr_prepare(&init_user_ns, direntry, attrs);
+	rc = setattr_prepare(&nop_mnt_idmap, direntry, attrs);
 	if (rc < 0)
 		goto out;
 
@@ -2859,7 +2859,7 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
 		fscache_resize_cookie(cifs_inode_cookie(inode), attrs->ia_size);
 	}
 
-	setattr_copy(&init_user_ns, inode, attrs);
+	setattr_copy(&nop_mnt_idmap, inode, attrs);
 	mark_inode_dirty(inode);
 
 	/* force revalidate when any of these times are set since some
@@ -2903,7 +2903,7 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM)
 		attrs->ia_valid |= ATTR_FORCE;
 
-	rc = setattr_prepare(&init_user_ns, direntry, attrs);
+	rc = setattr_prepare(&nop_mnt_idmap, direntry, attrs);
 	if (rc < 0)
 		goto cifs_setattr_exit;
 
@@ -3058,7 +3058,7 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 		fscache_resize_cookie(cifs_inode_cookie(inode), attrs->ia_size);
 	}
 
-	setattr_copy(&init_user_ns, inode, attrs);
+	setattr_copy(&nop_mnt_idmap, inode, attrs);
 	mark_inode_dirty(inode);
 
 cifs_setattr_exit:
@@ -3068,7 +3068,7 @@ cifs_setattr_exit:
 }
 
 int
-cifs_setattr(struct user_namespace *mnt_userns, struct dentry *direntry,
+cifs_setattr(struct mnt_idmap *idmap, struct dentry *direntry,
 	     struct iattr *attrs)
 {
 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index a5a097a69983..4510dea77be3 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -569,7 +569,7 @@ cifs_hl_exit:
 }
 
 int
-cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
+cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
 	     struct dentry *direntry, const char *symname)
 {
 	int rc = -EOPNOTSUPP;
diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
index 5f2fb2fd2e37..50e762fa1a14 100644
--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -89,7 +89,7 @@ static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
 }
 
 static int cifs_xattr_set(const struct xattr_handler *handler,
-			  struct user_namespace *mnt_userns,
+			  struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct inode *inode,
 			  const char *name, const void *value,
 			  size_t size, int flags)