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
  ...

5 files changed, 20 insertions, 20 deletions

diff --git a/fs/orangefs/acl.c b/fs/orangefs/acl.c
index c5da2091cefb..5aefb705bcc8 100644
--- a/fs/orangefs/acl.c
+++ b/fs/orangefs/acl.c
@@ -118,7 +118,7 @@ out:
 	return error;
 }
 
-int orangefs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int orangefs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct posix_acl *acl, int type)
 {
 	int error;
@@ -136,7 +136,7 @@ int orangefs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		 * and "mode" to the new desired value. It is up to
 		 * us to propagate the new mode back to the server...
 		 */
-		error = posix_acl_update_mode(&init_user_ns, inode,
+		error = posix_acl_update_mode(&nop_mnt_idmap, inode,
 					      &iattr.ia_mode, &acl);
 		if (error) {
 			gossip_err("%s: posix_acl_update_mode err: %d\n",
diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c
index 4df560894386..11e21a0e65ce 100644
--- a/fs/orangefs/inode.c
+++ b/fs/orangefs/inode.c
@@ -822,7 +822,7 @@ again:
 		ORANGEFS_I(inode)->attr_uid = current_fsuid();
 		ORANGEFS_I(inode)->attr_gid = current_fsgid();
 	}
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	spin_unlock(&inode->i_lock);
 	mark_inode_dirty(inode);
 
@@ -839,20 +839,20 @@ int __orangefs_setattr_mode(struct dentry *dentry, struct iattr *iattr)
 	ret = __orangefs_setattr(inode, iattr);
 	/* change mode on a file that has ACLs */
 	if (!ret && (iattr->ia_valid & ATTR_MODE))
-		ret = posix_acl_chmod(&init_user_ns, dentry, inode->i_mode);
+		ret = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
 	return ret;
 }
 
 /*
  * Change attributes of an object referenced by dentry.
  */
-int orangefs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int orangefs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct iattr *iattr)
 {
 	int ret;
 	gossip_debug(GOSSIP_INODE_DEBUG, "__orangefs_setattr: called on %pd\n",
 	    dentry);
-	ret = setattr_prepare(&init_user_ns, dentry, iattr);
+	ret = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (ret)
 	        goto out;
 	ret = __orangefs_setattr_mode(dentry, iattr);
@@ -866,7 +866,7 @@ out:
 /*
  * Obtain attributes of an object given a dentry
  */
-int orangefs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int orangefs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		     struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	int ret;
@@ -879,7 +879,7 @@ int orangefs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	ret = orangefs_inode_getattr(inode,
 	    request_mask & STATX_SIZE ? ORANGEFS_GETATTR_SIZE : 0);
 	if (ret == 0) {
-		generic_fillattr(&init_user_ns, inode, stat);
+		generic_fillattr(&nop_mnt_idmap, inode, stat);
 
 		/* override block size reported to stat */
 		if (!(request_mask & STATX_SIZE))
@@ -890,7 +890,7 @@ int orangefs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	return ret;
 }
 
-int orangefs_permission(struct user_namespace *mnt_userns,
+int orangefs_permission(struct mnt_idmap *idmap,
 			struct inode *inode, int mask)
 {
 	int ret;
@@ -905,7 +905,7 @@ int orangefs_permission(struct user_namespace *mnt_userns,
 	if (ret < 0)
 		return ret;
 
-	return generic_permission(&init_user_ns, inode, mask);
+	return generic_permission(&nop_mnt_idmap, inode, mask);
 }
 
 int orangefs_update_time(struct inode *inode, struct timespec64 *time, int flags)
@@ -944,7 +944,7 @@ static int orangefs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-static int orangefs_fileattr_set(struct user_namespace *mnt_userns,
+static int orangefs_fileattr_set(struct mnt_idmap *idmap,
 				 struct dentry *dentry, struct fileattr *fa)
 {
 	u64 val = 0;
diff --git a/fs/orangefs/namei.c b/fs/orangefs/namei.c
index 75c1a3dcf68c..77518e248cf7 100644
--- a/fs/orangefs/namei.c
+++ b/fs/orangefs/namei.c
@@ -15,7 +15,7 @@
 /*
  * Get a newly allocated inode to go with a negative dentry.
  */
-static int orangefs_create(struct user_namespace *mnt_userns,
+static int orangefs_create(struct mnt_idmap *idmap,
 			struct inode *dir,
 			struct dentry *dentry,
 			umode_t mode,
@@ -216,7 +216,7 @@ static int orangefs_unlink(struct inode *dir, struct dentry *dentry)
 	return ret;
 }
 
-static int orangefs_symlink(struct user_namespace *mnt_userns,
+static int orangefs_symlink(struct mnt_idmap *idmap,
 		         struct inode *dir,
 			 struct dentry *dentry,
 			 const char *symname)
@@ -305,7 +305,7 @@ out:
 	return ret;
 }
 
-static int orangefs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int orangefs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			  struct dentry *dentry, umode_t mode)
 {
 	struct orangefs_inode_s *parent = ORANGEFS_I(dir);
@@ -375,7 +375,7 @@ out:
 	return ret;
 }
 
-static int orangefs_rename(struct user_namespace *mnt_userns,
+static int orangefs_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir,
 			struct dentry *old_dentry,
 			struct inode *new_dir,
diff --git a/fs/orangefs/orangefs-kernel.h b/fs/orangefs/orangefs-kernel.h
index 6e0cc01b3a14..ce20d3443869 100644
--- a/fs/orangefs/orangefs-kernel.h
+++ b/fs/orangefs/orangefs-kernel.h
@@ -106,7 +106,7 @@ enum orangefs_vfs_op_states {
 extern const struct xattr_handler *orangefs_xattr_handlers[];
 
 extern struct posix_acl *orangefs_get_acl(struct inode *inode, int type, bool rcu);
-extern int orangefs_set_acl(struct user_namespace *mnt_userns,
+extern int orangefs_set_acl(struct mnt_idmap *idmap,
 			    struct dentry *dentry, struct posix_acl *acl,
 			    int type);
 int __orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
@@ -362,12 +362,12 @@ struct inode *orangefs_new_inode(struct super_block *sb,
 
 int __orangefs_setattr(struct inode *, struct iattr *);
 int __orangefs_setattr_mode(struct dentry *dentry, struct iattr *iattr);
-int orangefs_setattr(struct user_namespace *, struct dentry *, struct iattr *);
+int orangefs_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
 
-int orangefs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int orangefs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		     struct kstat *stat, u32 request_mask, unsigned int flags);
 
-int orangefs_permission(struct user_namespace *mnt_userns,
+int orangefs_permission(struct mnt_idmap *idmap,
 			struct inode *inode, int mask);
 
 int orangefs_update_time(struct inode *, struct timespec64 *, int);
diff --git a/fs/orangefs/xattr.c b/fs/orangefs/xattr.c
index 9a5b757fbd2f..6ecad4f94ae6 100644
--- a/fs/orangefs/xattr.c
+++ b/fs/orangefs/xattr.c
@@ -526,7 +526,7 @@ out_unlock:
 }
 
 static int orangefs_xattr_set_default(const struct xattr_handler *handler,
-				      struct user_namespace *mnt_userns,
+				      struct mnt_idmap *idmap,
 				      struct dentry *unused,
 				      struct inode *inode,
 				      const char *name,