On Sun, Oct 31, 2021 at 07:28:17PM +0800, Qu Wenruo wrote:

On 2021/10/31 10:21, Sidong Yang wrote:

quoted

This patch makes old balance command to print warn mesg same as in start
command. It makes a function that print warn mesg and commands use that
function.

Issue: #411

Signed-off-by: Sidong Yang <redacted>

Hi, Qu.

Thanks for review!

The patch is indeed solving a problem, so good job.

But I found something weird which may worth some refactor before the fix.

quoted

---
  cmds/balance.c | 37 ++++++++++++++++++++++---------------
  1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/cmds/balance.c b/cmds/balance.c
index 7abc69d9..8d8db8a2 100644
--- a/cmds/balance.c
+++ b/cmds/balance.c

@@ -303,6 +303,25 @@ enum {
  	BALANCE_START_NOWARN  = 1 << 1

We have such flag for do_balance(), but it only checks START_FILTERS, no
check for START_NOWARN.

Yes. I've checked do_balance() that it doesn't check START_NOWARN.

So can we handle it better for the warning in do_balance() other than
cmd_balance_full() or cmd_balance_start()?

Totally agree. It would be better that it prints warning message in do_balance().
Also it's a way to simplify the logic.

And fully utilize the START_NOWARN flags?

I'll send you v2 soon.

Thanks,
Sidong

Thanks,
Qu

quoted

  };

+static void print_start_warn_mesg()
+{
+	int delay = 10;
+
+	printf("WARNING:\n\n");
+	printf("\tFull balance without filters requested. This operation is very\n");
+	printf("\tintense and takes potentially very long. It is recommended to\n");
+	printf("\tuse the balance filters to narrow down the scope of balance.\n");
+	printf("\tUse 'btrfs balance start --full-balance' option to skip this\n");
+	printf("\twarning. The operation will start in %d seconds.\n", delay);
+	printf("\tUse Ctrl-C to stop it.\n");
+	while (delay) {
+		printf("%2d", delay--);
+		fflush(stdout);
+		sleep(1);
+	}
+	printf("\nStarting balance without any filters.\n");
+}
+
  static int do_balance(const char *path, struct btrfs_ioctl_balance_args *args,
  		      unsigned flags, bool enqueue)
  {

@@ -548,21 +567,7 @@ static int cmd_balance_start(const struct cmd_struct *cmd,
  	}

  	if (!(start_flags & BALANCE_START_FILTERS) && !(start_flags & BALANCE_START_NOWARN)) {
-		int delay = 10;
-
-		printf("WARNING:\n\n");
-		printf("\tFull balance without filters requested. This operation is very\n");
-		printf("\tintense and takes potentially very long. It is recommended to\n");
-		printf("\tuse the balance filters to narrow down the scope of balance.\n");
-		printf("\tUse 'btrfs balance start --full-balance' option to skip this\n");
-		printf("\twarning. The operation will start in %d seconds.\n", delay);
-		printf("\tUse Ctrl-C to stop it.\n");
-		while (delay) {
-			printf("%2d", delay--);
-			fflush(stdout);
-			sleep(1);
-		}
-		printf("\nStarting balance without any filters.\n");
+		print_start_warn_mesg();
  	}

  	if (force)

@@ -886,6 +891,8 @@ static int cmd_balance(const struct cmd_struct *cmd, int argc, char **argv)
  		memset(&args, 0, sizeof(args));
  		args.flags |= BTRFS_BALANCE_TYPE_MASK;

+		print_start_warn_mesg();
+
  		/* No enqueueing supported for the obsolete syntax */
  		return do_balance(argv[1], &args, 0, false);
  	}