ext4: make mount option parsing loop more logical

The loop looking for correct mount option entry is more logical if it is
written rewritten as an empty loop looking for correct option entry and then
code handling the option. It also saves one level of indentation for a lot of
code so we can join a couple of split lines.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/super.c

@@ -1508,8 +1508,7 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 	case Opt_sb:
 		return 1;	/* handled by get_sb_block() */
 	case Opt_removed:
-		ext4_msg(sb, KERN_WARNING,
-			 "Ignoring removed %s option", opt);
+		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
 		return 1;
 	case Opt_abort:
 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
@@ -1519,132 +1518,129 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 		return 1;
 	}
 
-	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
-		if (token != m->token)
-			continue;
-		if (args->from && match_int(args, &arg))
+	for (m = ext4_mount_opts; m->token != Opt_err; m++)
+		if (token == m->token)
+			break;
+
+	if (m->token == Opt_err) {
+		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
+			 "or missing value", opt);
+		return -1;
+	}
+
+	if (args->from && match_int(args, &arg))
+		return -1;
+	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
+		return -1;
+	if (m->flags & MOPT_EXPLICIT)
+		set_opt2(sb, EXPLICIT_DELALLOC);
+	if (m->flags & MOPT_CLEAR_ERR)
+		clear_opt(sb, ERRORS_MASK);
+	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
+		ext4_msg(sb, KERN_ERR, "Cannot change quota "
+			 "options when quota turned on");
+		return -1;
+	}
+
+	if (m->flags & MOPT_NOSUPPORT) {
+		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
+	} else if (token == Opt_commit) {
+		if (arg == 0)
+			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
+		sbi->s_commit_interval = HZ * arg;
+	} else if (token == Opt_max_batch_time) {
+		if (arg == 0)
+			arg = EXT4_DEF_MAX_BATCH_TIME;
+		sbi->s_max_batch_time = arg;
+	} else if (token == Opt_min_batch_time) {
+		sbi->s_min_batch_time = arg;
+	} else if (token == Opt_inode_readahead_blks) {
+		if (arg > (1 << 30))
 			return -1;
-		if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
+		if (arg && !is_power_of_2(arg)) {
+			ext4_msg(sb, KERN_ERR, "EXT4-fs: inode_readahead_blks"
+				 " must be a power of 2");
 			return -1;
-		if (m->flags & MOPT_EXPLICIT)
-			set_opt2(sb, EXPLICIT_DELALLOC);
-		if (m->flags & MOPT_CLEAR_ERR)
-			clear_opt(sb, ERRORS_MASK);
-		if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
-			ext4_msg(sb, KERN_ERR, "Cannot change quota "
-				 "options when quota turned on");
+		}
+		sbi->s_inode_readahead_blks = arg;
+	} else if (token == Opt_init_itable) {
+		set_opt(sb, INIT_INODE_TABLE);
+		if (!args->from)
+			arg = EXT4_DEF_LI_WAIT_MULT;
+		sbi->s_li_wait_mult = arg;
+	} else if (token == Opt_max_dir_size_kb) {
+		sbi->s_max_dir_size_kb = arg;
+	} else if (token == Opt_stripe) {
+		sbi->s_stripe = arg;
+	} else if (token == Opt_resuid) {
+		uid = make_kuid(current_user_ns(), arg);
+		if (!uid_valid(uid)) {
+			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
 			return -1;
 		}
-
-		if (m->flags & MOPT_NOSUPPORT) {
-			ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
-		} else if (token == Opt_commit) {
-			if (arg == 0)
-				arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
-			sbi->s_commit_interval = HZ * arg;
-		} else if (token == Opt_max_batch_time) {
-			if (arg == 0)
-				arg = EXT4_DEF_MAX_BATCH_TIME;
-			sbi->s_max_batch_time = arg;
-		} else if (token == Opt_min_batch_time) {
-			sbi->s_min_batch_time = arg;
-		} else if (token == Opt_inode_readahead_blks) {
-			if (arg > (1 << 30))
-				return -1;
-			if (arg && !is_power_of_2(arg)) {
-				ext4_msg(sb, KERN_ERR,
-					 "EXT4-fs: inode_readahead_blks"
-					 " must be a power of 2");
-				return -1;
-			}
-			sbi->s_inode_readahead_blks = arg;
-		} else if (token == Opt_init_itable) {
-			set_opt(sb, INIT_INODE_TABLE);
-			if (!args->from)
-				arg = EXT4_DEF_LI_WAIT_MULT;
-			sbi->s_li_wait_mult = arg;
-		} else if (token == Opt_max_dir_size_kb) {
-			sbi->s_max_dir_size_kb = arg;
-		} else if (token == Opt_stripe) {
-			sbi->s_stripe = arg;
-		} else if (token == Opt_resuid) {
-			uid = make_kuid(current_user_ns(), arg);
-			if (!uid_valid(uid)) {
-				ext4_msg(sb, KERN_ERR,
-					 "Invalid uid value %d", arg);
-				return -1;
-			}
-			sbi->s_resuid = uid;
-		} else if (token == Opt_resgid) {
-			gid = make_kgid(current_user_ns(), arg);
-			if (!gid_valid(gid)) {
-				ext4_msg(sb, KERN_ERR,
-					 "Invalid gid value %d", arg);
-				return -1;
-			}
-			sbi->s_resgid = gid;
-		} else if (token == Opt_journal_dev) {
-			if (is_remount) {
-				ext4_msg(sb, KERN_ERR,
-					 "Cannot specify journal on remount");
-				return -1;
-			}
-			*journal_devnum = arg;
-		} else if (token == Opt_journal_ioprio) {
-			if (arg > 7) {
+		sbi->s_resuid = uid;
+	} else if (token == Opt_resgid) {
+		gid = make_kgid(current_user_ns(), arg);
+		if (!gid_valid(gid)) {
+			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
+			return -1;
+		}
+		sbi->s_resgid = gid;
+	} else if (token == Opt_journal_dev) {
+		if (is_remount) {
+			ext4_msg(sb, KERN_ERR,
+				 "Cannot specify journal on remount");
+			return -1;
+		}
+		*journal_devnum = arg;
+	} else if (token == Opt_journal_ioprio) {
+		if (arg > 7) {
+			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
+				 " (must be 0-7)");
+			return -1;
+		}
+		*journal_ioprio =
+			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
+	} else if (m->flags & MOPT_DATAJ) {
+		if (is_remount) {
+			if (!sbi->s_journal)
+				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
+			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
 				ext4_msg(sb, KERN_ERR,
-					 "Invalid journal IO priority"
-					 " (must be 0-7)");
-				return -1;
-			}
-			*journal_ioprio =
-				IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
-		} else if (m->flags & MOPT_DATAJ) {
-			if (is_remount) {
-				if (!sbi->s_journal)
-					ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
-				else if (test_opt(sb, DATA_FLAGS) !=
-					 m->mount_opt) {
-					ext4_msg(sb, KERN_ERR,
 					 "Cannot change data mode on remount");
-					return -1;
-				}
-			} else {
-				clear_opt(sb, DATA_FLAGS);
-				sbi->s_mount_opt |= m->mount_opt;
-			}
-#ifdef CONFIG_QUOTA
-		} else if (m->flags & MOPT_QFMT) {
-			if (sb_any_quota_loaded(sb) &&
-			    sbi->s_jquota_fmt != m->mount_opt) {
-				ext4_msg(sb, KERN_ERR, "Cannot "
-					 "change journaled quota options "
-					 "when quota turned on");
 				return -1;
 			}
-			sbi->s_jquota_fmt = m->mount_opt;
-#endif
 		} else {
-			if (!args->from)
-				arg = 1;
-			if (m->flags & MOPT_CLEAR)
-				arg = !arg;
-			else if (unlikely(!(m->flags & MOPT_SET))) {
-				ext4_msg(sb, KERN_WARNING,
-					 "buggy handling of option %s", opt);
-				WARN_ON(1);
-				return -1;
-			}
-			if (arg != 0)
-				sbi->s_mount_opt |= m->mount_opt;
-			else
-				sbi->s_mount_opt &= ~m->mount_opt;
+			clear_opt(sb, DATA_FLAGS);
+			sbi->s_mount_opt |= m->mount_opt;
 		}
-		return 1;
+#ifdef CONFIG_QUOTA
+	} else if (m->flags & MOPT_QFMT) {
+		if (sb_any_quota_loaded(sb) &&
+		    sbi->s_jquota_fmt != m->mount_opt) {
+			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
+				 "quota options when quota turned on");
+			return -1;
+		}
+		sbi->s_jquota_fmt = m->mount_opt;
+#endif
+	} else {
+		if (!args->from)
+			arg = 1;
+		if (m->flags & MOPT_CLEAR)
+			arg = !arg;
+		else if (unlikely(!(m->flags & MOPT_SET))) {
+			ext4_msg(sb, KERN_WARNING,
+				 "buggy handling of option %s", opt);
+			WARN_ON(1);
+			return -1;
+		}
+		if (arg != 0)
+			sbi->s_mount_opt |= m->mount_opt;
+		else
+			sbi->s_mount_opt &= ~m->mount_opt;
 	}
-	ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
-		 "or missing value", opt);
-	return -1;
+	return 1;
 }
 
 static int parse_options(char *options, struct super_block *sb,