[PATCH] btrfs-progs: balance: fix some cases wrongly parsed as old syntax

[Wang Yugui <wangyugui@e16-tech.com>]

Some cases of 'btrfs balance' are wrongly parsed as old syntax.

an example:
$ btrfs balance status
ERROR: cannot access 'status': No such file or directory

currently, only 'start' is successfully excluded in the check of old syntax.
fix it by adding others in the check of old syntax.

Signed-off-by: Wang Yugui <wangyugui@e16-tech.com>
---
 cmds/balance.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/cmds/balance.c b/cmds/balance.c
index c5e10f92..bafd1714 100644
--- a/cmds/balance.c
+++ b/cmds/balance.c
@@ -852,8 +852,23 @@ static const struct cmd_group balance_cmd_group = {
 
 static int cmd_balance(const struct cmd_struct *cmd, int argc, char **argv)
 {
-	if (argc == 2 && strcmp("start", argv[1]) != 0) {
-		/* old 'btrfs filesystem balance <path>' syntax */
+	bool old_syntax = true; /* old 'btrfs balance <path>' syntax */
+	if (argc >= 2)
+	{
+		int i;
+		for (i = 0; balance_cmd_group.commands[i] != NULL; i++)
+		{
+			if (strcmp(argv[1], balance_cmd_group.commands[i]->token) == 0)
+			{
+				old_syntax = false;
+				break;
+			}
+		}
+	} else {
+		old_syntax = false;
+	}
+	if (old_syntax)
+	{
 		struct btrfs_ioctl_balance_args args;
 
 		memset(&args, 0, sizeof(args));
-- 
2.36.2