f2fs: port to vfs{g,u}id_t and associated helpers

A while ago we introduced a dedicated vfs{g,u}id_t type in commit
1e5267cd ("mnt_idmapping: add vfs{g,u}id_t"). We already switched
over a good part of the VFS. Ultimately we will remove all legacy
idmapped mount helpers that operate only on k{g,u}id_t in favor of the
new type safe helpers that operate on vfs{g,u}id_t.

Cc: Seth Forshee (Digital Ocean) <sforshee@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: linux-f2fs-devel@lists.sourceforge.net
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/acl.c

@@ -219,7 +219,7 @@ static int f2fs_acl_update_mode(struct user_namespace *mnt_userns,
 		return error;
 	if (error == 0)
 		*acl = NULL;
-	if (!in_group_p(i_gid_into_mnt(mnt_userns, inode)) &&
+	if (!vfsgid_in_group_p(i_gid_into_vfsgid(mnt_userns, inode)) &&
 	    !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
 		mode &= ~S_ISGID;
 	*mode_p = mode;

fs/f2fs/file.c

@@ -871,9 +871,10 @@ static void __setattr_copy(struct user_namespace *mnt_userns,
 		inode->i_ctime = attr->ia_ctime;
 	if (ia_valid & ATTR_MODE) {
 		umode_t mode = attr->ia_mode;
-		kgid_t kgid = i_gid_into_mnt(mnt_userns, inode);
+		vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
 
-		if (!in_group_p(kgid) && !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
+		if (!vfsgid_in_group_p(vfsgid) &&
+		    !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
 			mode &= ~S_ISGID;
 		set_acl_inode(inode, mode);
 	}