Re: [PATCH v6 2/8] Add --monitor option to btrfs balance progress.

[Andreas Philipp <philipp.andreas@gmail.com>]

On 01.05.2011 17:47, Hugo Mills wrote:
> For the impatient, this patch introduces the pot-watching --monitor
> option, which checks the balance progress at regular intervals, and
> updates a single status line with the current progress and an
> estimated completion time.
>
> Signed-off-by: Hugo Mills <hugo@carfax.org.uk>
> ---
>  btrfs.c        |    4 +-
>  btrfs_cmds.c   |  109 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
>  ioctl.h        |    2 +-
>  man/btrfs.8.in |    7 ++--
>  4 files changed, 106 insertions(+), 16 deletions(-)
>
> diff --git a/btrfs.c b/btrfs.c
> index 3a24019..0b6186c 100644
> --- a/btrfs.c
> +++ b/btrfs.c
> @@ -99,8 +99,8 @@ static struct Command commands[] = {
>  	  "balance start", "<path>\n"
>  		"Synonym for \"btrfs filesystem balance\"."
>  	},
> -	{ do_balance_progress, 1,
> -	  "balance progress", "<path>\n"
> +	{ do_balance_progress, -1,
> +	  "balance progress", "[-m|--monitor] <path>\n"
>  		"Show progress of the balance operation running on <path>."
>  	},
>  	{ do_scan,
> diff --git a/btrfs_cmds.c b/btrfs_cmds.c
> index 00dda0a..ad2300d 100644
> --- a/btrfs_cmds.c
> +++ b/btrfs_cmds.c
> @@ -797,22 +797,108 @@ int get_balance_progress(char *path, struct btrfs_ioctl_balance_progress *bal)
>  	return err;
>  }
>  
> +const struct option progress_options[] = {
> +	{ "monitor", 0, NULL, 'm' },
> +	{ NULL, 0, NULL, 0 }
> +};
> +
>  int do_balance_progress(int argc, char **argv)
>  {
>  	char *path;
>  	int ret = 0;
>  	int err = 0;
>  	struct btrfs_ioctl_balance_progress bal;
> +	__u64 last_completed = -1;
> +	__u64 initial_completed = -1;
> +	struct timeval now;
> +	struct timeval started;
> +	int monitor = 0;
> +
> +	optind = 1;
> +	while(1) {
> +		int c = getopt_long(argc, argv, "m", progress_options, NULL);
> +		if (c < 0)
> +			break;
> +		switch(c) {
> +		case 'm':
> +			monitor = 1;
> +			break;
> +		default:
> +			fprintf(stderr, "Invalid arguments for balance progress\n");
> +			free(argv);
> +			return 1;
> +		}
> +	}
> +
> +	if(optind >= argc) {
> +		fprintf(stderr, "No filesystem path given for progress\n");
> +		return 1;
> +	}
> +
> +	path = argv[optind];
> +	do {
> +		int prs = 0;
>  
> -	path = argv[1];
> +		ret = get_balance_progress(path, &bal);
> +		if (ret)
> +			break;
>  
> -	ret = get_balance_progress(path, &bal);
> -	if (!ret)
> -		printf("\r%u/%u block groups moved, "
> -		       "%0.2f%% complete.\n",
> -		       bal.completed,
> -		       bal.expected,
> -		       (float)bal.completed/bal.expected*100.0);
> +		if (last_completed != bal.completed) {
> +			printf("\r%u/%u block groups moved, "
> +			       "%0.2f%% complete.",
> +			       bal.completed,
> +			       bal.expected,
> +			       (float)bal.completed/bal.expected*100.0);
> +		}
> +
> +		if (initial_completed != -1
> +		    && initial_completed != bal.completed) {
> +			ret = gettimeofday(&now, NULL);
> +			if (ret) {
> +				fprintf(stderr, "Can't read current time\n");
> +				return 22;
> +			}
> +			/* Seconds per block */
> +			float rate = (float)(now.tv_sec - started.tv_sec)
> +					/ (bal.completed - initial_completed);
> +			int secs_remaining = rate
> +			  		* (bal.expected - bal.completed);
> +			printf(" Time remaining");
> +			if (secs_remaining >= 60*60*24) {
> +				printf(" %dd", secs_remaining / (60*60*24));
> +				secs_remaining %= 60*60*24;
> +				prs = 1;
> +			}
> +			if (prs || secs_remaining >= 60*60) {
> +				printf(" %dh", secs_remaining / (60*60));
> +				secs_remaining %= 60*60;
> +				prs = 1;
> +			}
> +			if (prs || secs_remaining > 60) {
> +				printf(" %dm", secs_remaining / 60);
> +				secs_remaining %= 60;
> +			}
> +			printf(" %ds\x1b[K", secs_remaining);
> +		}
> +
> +		if (last_completed != -1 && last_completed != bal.completed) {
> +			initial_completed = bal.completed;
> +			ret = gettimeofday(&started, NULL);
> +			if (ret) {
> +				fprintf(stderr, "Can't read current time\n");
> +				return 22;
> +			}
> +		}
> +
> +		last_completed = bal.completed;
> +
> +		if (monitor) {
> +			fflush(stdout);
> +			sleep(1);
> +		} else {
> +			printf("\n");
> +		}
> +	} while(monitor);
>  
>  	switch(ret) {
>  	case 0:
> @@ -821,10 +907,13 @@ int do_balance_progress(int argc, char **argv)
>  		fprintf(stderr, "ERROR: can't access '%s'\n", path);
>  		return 13;
>  	case EINVAL:
> -		fprintf(stderr,
> + 		if (!monitor) {
> + 			fprintf(stderr,
>  				"No balance operation running on '%s'.\n",
>  				path);
> -		return 20;
> +			return 20;
> +		}
> +		break;
>  	default:
>  		fprintf(stderr, "ERROR: ioctl returned error %d.", err);

The output of fprintf should be terminated by a newline.
Thanks,
Andreas

>  		return 21;
> diff --git a/ioctl.h b/ioctl.h
> index f07d3a2..3eeaa33 100644
> --- a/ioctl.h
> +++ b/ioctl.h
> @@ -174,6 +174,6 @@ struct btrfs_ioctl_balance_progress {
>  #define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 19, u64)
>  #define BTRFS_IOC_SPACE_INFO _IOWR(BTRFS_IOCTL_MAGIC, 20, \
>  				    struct btrfs_ioctl_space_args)
> -#define BTRFS_IOC_BALANCE_PROGRESS _IOR(BTRFS_IOCTL_MAGIC, 25, \
> +#define BTRFS_IOC_BALANCE_PROGRESS _IOR(BTRFS_IOCTL_MAGIC, 27, \
>  					struct btrfs_ioctl_balance_progress)
>  #endif
> diff --git a/man/btrfs.8.in b/man/btrfs.8.in
> index 7b66fb7..5fcad89 100644
> --- a/man/btrfs.8.in
> +++ b/man/btrfs.8.in
> @@ -27,7 +27,7 @@ btrfs \- control a btrfs filesystem
>  .PP
>  \fBbtrfs\fP \fBbalance start\fP\fI <path> \fP
>  .PP
> -\fBbtrfs\fP \fBbalance progress\fP\fI <path>\fP
> +\fBbtrfs\fP \fBbalance progress\fP [\fB-m\fP|\fB--monitor\fP] \fI<path>\fP
>  .PP
>  \fBbtrfs\fP \fBdevice show\fP\fI <dev>|<label> [<dev>|<label>...]\fP
>  .PP
> @@ -162,9 +162,10 @@ Add device(s) to the filesystem identified by \fI<path>\fR.
>  Remove device(s) from a filesystem identified by \fI<path>\fR.
>  .PP
>  
> -\fBbalance progress\fP \fI<path>\fP
> +\fBbalance progress\fP [\fB-m\fP|\fB--monitor\fP] \fI<path>\fP
>  Report progress on the currently-running balance operation on the
> -filesystem mounted at \fI<path>\fP.
> +filesystem mounted at \fI<path>\fP. Use --monitor to report progress
> +continually, including an estimate of completion time.
>  
>  .SH EXIT STATUS
>  \fBbtrfs\fR returns a zero exist status if it succeeds. Non zero is returned in