userns: Convert ext2 to use kuid/kgid where appropriate.

Acked-by: Serge Hallyn <[e-mail]>
Signed-off-by: Eric W. Biederman <[e-mail]>

fs/ext2/balloc.c

···
 	free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 	root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count);
 	if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
-		sbi->s_resuid != current_fsuid() &&
-		(sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) {
+		!uid_eq(sbi->s_resuid, current_fsuid()) &&
+		(gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) ||
+		 !in_group_p (sbi->s_resgid))) {
 		return 0;
 	}
 	return 1;

fs/ext2/ext2.h

···
 	struct buffer_head ** s_group_desc;
 	unsigned long  s_mount_opt;
 	unsigned long s_sb_block;
-	uid_t s_resuid;
-	gid_t s_resgid;
+	kuid_t s_resuid;
+	kgid_t s_resgid;
 	unsigned short s_mount_state;
 	unsigned short s_pad;
 	int s_addr_per_block_bits;
···
  */
 struct ext2_mount_options {
 	unsigned long s_mount_opt;
-	uid_t s_resuid;
-	gid_t s_resgid;
+	kuid_t s_resuid;
+	kgid_t s_resgid;
 };
 
 /*

fs/ext2/inode.c

···
 	struct inode *inode;
 	long ret = -EIO;
 	int n;
+	uid_t i_uid;
+	gid_t i_gid;
 
 	inode = iget_locked(sb, ino);
 	if (!inode)
···
 	}
 
 	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
-	inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
-	inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
+	i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
+	i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
 	if (!(test_opt (inode->i_sb, NO_UID32))) {
-		inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
-		inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
+		i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
+		i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
 	}
+	i_uid_write(inode, i_uid);
+	i_gid_write(inode, i_gid);
 	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 	inode->i_size = le32_to_cpu(raw_inode->i_size);
 	inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
···
 	struct ext2_inode_info *ei = EXT2_I(inode);
 	struct super_block *sb = inode->i_sb;
 	ino_t ino = inode->i_ino;
-	uid_t uid = inode->i_uid;
-	gid_t gid = inode->i_gid;
+	uid_t uid = i_uid_read(inode);
+	gid_t gid = i_gid_read(inode);
 	struct buffer_head * bh;
 	struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
 	int n;
···
 
 	if (is_quota_modification(inode, iattr))
 		dquot_initialize(inode);
-	if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
-	    (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
+	if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) ||
+	    (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) {
 		error = dquot_transfer(inode, iattr);
 		if (error)
 			return error;

fs/ext2/super.c

···
 		seq_puts(seq, ",grpid");
 	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 		seq_puts(seq, ",nogrpid");
-	if (sbi->s_resuid != EXT2_DEF_RESUID ||
+	if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 	    le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
-		seq_printf(seq, ",resuid=%u", sbi->s_resuid);
+		seq_printf(seq, ",resuid=%u",
+				from_kuid_munged(&init_user_ns, sbi->s_resuid));
 	}
-	if (sbi->s_resgid != EXT2_DEF_RESGID ||
+	if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 	    le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
-		seq_printf(seq, ",resgid=%u", sbi->s_resgid);
+		seq_printf(seq, ",resgid=%u",
+				from_kgid_munged(&init_user_ns, sbi->s_resgid));
 	}
 	if (test_opt(sb, ERRORS_RO)) {
 		int def_errors = le16_to_cpu(es->s_errors);
···
 	struct ext2_sb_info *sbi = EXT2_SB(sb);
 	substring_t args[MAX_OPT_ARGS];
 	int option;
+	kuid_t uid;
+	kgid_t gid;
 
 	if (!options)
 		return 1;
···
 		case Opt_resuid:
 			if (match_int(&args[0], &option))
 				return 0;
-			sbi->s_resuid = option;
+			uid = make_kuid(current_user_ns(), option);
+			if (!uid_valid(uid)) {
+				ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
+				return -1;
+
+			}
+			sbi->s_resuid = uid;
 			break;
 		case Opt_resgid:
 			if (match_int(&args[0], &option))
 				return 0;
-			sbi->s_resgid = option;
+			gid = make_kgid(current_user_ns(), option);
+			if (!gid_valid(gid)) {
+				ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
+				return -1;
+			}
+			sbi->s_resgid = gid;
 			break;
 		case Opt_sb:
 			/* handled by get_sb_block() instead of here */
···
 	else
 		set_opt(sbi->s_mount_opt, ERRORS_RO);
 
-	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
-	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
+	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
+	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 	
 	set_opt(sbi->s_mount_opt, RESERVATION);
 

init/Kconfig

···
 	depends on ECRYPT_FS = n
 	depends on EFS_FS = n
 	depends on EXOFS_FS = n
-	depends on EXT2_FS = n
 	depends on EXT3_FS = n
 	depends on EXT4_FS = n
 	depends on FAT_FS = n