[PATCH v2 3/3] User-space tool for cancelling balance operations.

[PATCH v2 3/3] User-space tool for cancelling balance operations.

[Hugo Mills]

Add an option to the btrfs tool to use the ioctl for cancelling
balance operations.

Signed-off-by: Hugo Mills <hugo@carfax.org.uk>
---
 btrfs.c      |    4 ++++
 btrfs_cmds.c |   41 +++++++++++++++++++++++++++++++++++++++++
 btrfs_cmds.h |    1 +
 ioctl.h      |    1 +
 4 files changed, 47 insertions(+), 0 deletions(-)

diff --git a/btrfs.c b/btrfs.c
index 0b6186c..93f7886 100644
--- a/btrfs.c
+++ b/btrfs.c
@@ -103,6 +103,10 @@ static struct Command commands[] = {
 	  "balance progress", "[-m|--monitor] <path>\n"
 		"Show progress of the balance operation running on <path>."
 	},
+	{ do_balance_cancel, 1,
+	  "balance cancel", "<path>\n"
+		"Cancel the balance operation running on <path>."
+	},
 	{ do_scan,
 	  999, "device scan", "[<device> [<device>..]\n"
 		"Scan all device for or the passed device for a btrfs\n"
diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index c681b5a..d246a8b 100644
--- a/btrfs_cmds.c
+++ b/btrfs_cmds.c
@@ -922,6 +922,47 @@ int do_balance_progress(int argc, char **argv)
 	return 0;
 }
 
+int do_balance_cancel(int nargs, char **argv)
+{
+	char *path = argv[1];
+	int fdmnt;
+	int ret = 0;
+	int err = 0;
+
+	fdmnt = open_file_or_dir(path);
+	if(fdmnt < 0) {
+		fprintf(stderr, "ERROR: can't access '%s'\n", path);
+		return 12;
+	}
+
+	ret = ioctl(fdmnt, BTRFS_IOC_BALANCE_CANCEL, NULL);
+	err = errno;
+
+	if(ret) {
+		switch(err) {
+		case 0:
+			break;
+		case EINVAL:
+			fprintf(stderr, "ERROR: no balance in progress.\n");
+			err = 20;
+			break;
+		case ECANCELED:
+			fprintf(stderr, "ERROR: operation already cancelled.\n");
+			err = 21;
+			break;
+		default:
+			fprintf(stderr, "ERROR: ioctl returned error '%d'.\n",
+				err);
+			err = 22;
+			break;
+		}
+	}
+
+	close(fdmnt);
+
+	return err;
+}
+
 int do_remove_volume(int nargs, char **args)
 {
 
diff --git a/btrfs_cmds.h b/btrfs_cmds.h
index 47b0a27..5cb0d9c 100644
--- a/btrfs_cmds.h
+++ b/btrfs_cmds.h
@@ -24,6 +24,7 @@ int do_show_filesystem(int nargs, char **argv);
 int do_add_volume(int nargs, char **args);
 int do_balance(int nargs, char **argv);
 int do_balance_progress(int nargs, char **argv);
+int do_balance_cancel(int nargs, char **argv);
 int do_remove_volume(int nargs, char **args);
 int do_scan(int nargs, char **argv);
 int do_resize(int nargs, char **argv);
diff --git a/ioctl.h b/ioctl.h
index 888ceb9..1fc665b 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -176,4 +176,5 @@ struct btrfs_ioctl_balance_progress {
 				    struct btrfs_ioctl_space_args)
 #define BTRFS_IOC_BALANCE_PROGRESS _IOR(BTRFS_IOCTL_MAGIC, 25, \
 					struct btrfs_ioctl_balance_progress)
+#define BTRFS_IOC_BALANCE_CANCEL _IO(BTRFS_IOCTL_MAGIC, 26)
 #endif
-- 
1.7.1

[PATCH v2 1/3] Balance progress monitoring.

[Hugo Mills]

This patch introduces a basic form of progress monitoring for balance
operations, by counting the number of block groups remaining. The
information is exposed to userspace by an ioctl.

We also add "btrfs balance start" as an alias for "btrfs filesystem
balance", so that all balance-related functions are available under
one prefix.

Signed-off-by: Hugo Mills <hugo@carfax.org.uk>
---
 btrfs.c        |    8 +++++++
 btrfs_cmds.c   |   60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 btrfs_cmds.h   |    1 +
 ioctl.h        |    7 ++++++
 man/btrfs.8.in |    7 ++++++
 5 files changed, 83 insertions(+), 0 deletions(-)

diff --git a/btrfs.c b/btrfs.c
index 46314cf..0b6186c 100644
--- a/btrfs.c
+++ b/btrfs.c
@@ -95,6 +95,14 @@ static struct Command commands[] = {
 	  "filesystem balance", "<path>\n"
 		"Balance the chunks across the device."
 	},
+	{ do_balance, 1,
+	  "balance start", "<path>\n"
+		"Synonym for \"btrfs filesystem balance\"."
+	},
+	{ do_balance_progress, -1,
+	  "balance progress", "[-m|--monitor] <path>\n"
+		"Show progress of the balance operation running on <path>."
+	},
 	{ do_scan,
 	  999, "device scan", "[<device> [<device>..]\n"
 		"Scan all device for or the passed device for a btrfs\n"
diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index 8031c58..2745d64 100644
--- a/btrfs_cmds.c
+++ b/btrfs_cmds.c
@@ -28,6 +28,7 @@
 #include <limits.h>
 #include <uuid/uuid.h>
 #include <ctype.h>
+#include <getopt.h>
 
 #undef ULONG_MAX
 
@@ -776,6 +777,65 @@ int do_balance(int argc, char **argv)
 	}
 	return 0;
 }
+
+int get_balance_progress(char *path, struct btrfs_ioctl_balance_progress *bal)
+{
+	int fdmnt;
+	int ret = 0;
+	int err = 0;
+
+	fdmnt = open_file_or_dir(path);
+	if(fdmnt < 0) {
+		return -1;
+	}
+
+	ret = ioctl(fdmnt, BTRFS_IOC_BALANCE_PROGRESS, bal);
+	if(ret)
+		err = errno;
+	close(fdmnt);
+
+	return err;
+}
+
+int do_balance_progress(int argc, char **argv)
+{
+	char *path;
+	int ret = 0;
+	int err = 0;
+	struct btrfs_ioctl_balance_progress bal;
+
+	path = argv[1];
+
+	ret = get_balance_progress(path, &bal);
+	if (!ret)
+		printf("\r%llu/%llu block groups moved, "
+		       "%0.2f%% complete.\n",
+		       bal.completed,
+		       bal.expected,
+		       (float)bal.completed/bal.expected*100.0);
+
+	switch(ret) {
+	case 0:
+		break;
+	case -1:
+		fprintf(stderr, "ERROR: can't access '%s'\n", path);
+		return 13;
+	case EINVAL:
+		if (!monitor) {
+			fprintf(stderr,
+				"No balance operation running on '%s'.\n",
+				path);
+			return 20;
+		}
+		break;
+	default:
+		fprintf(stderr, "ERROR: ioctl returned error %d.", err);
+		return 21;
+	}
+
+	return 0;
+}
+
 int do_remove_volume(int nargs, char **args)
 {
 
diff --git a/btrfs_cmds.h b/btrfs_cmds.h
index 7bde191..47b0a27 100644
--- a/btrfs_cmds.h
+++ b/btrfs_cmds.h
@@ -23,6 +23,7 @@ int do_defrag(int argc, char **argv);
 int do_show_filesystem(int nargs, char **argv);
 int do_add_volume(int nargs, char **args);
 int do_balance(int nargs, char **argv);
+int do_balance_progress(int nargs, char **argv);
 int do_remove_volume(int nargs, char **args);
 int do_scan(int nargs, char **argv);
 int do_resize(int nargs, char **argv);
diff --git a/ioctl.h b/ioctl.h
index 776d7a9..888ceb9 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -132,6 +132,11 @@ struct btrfs_ioctl_space_args {
 	struct btrfs_ioctl_space_info spaces[0];
 };
 
+struct btrfs_ioctl_balance_progress {
+	__u64 expected;
+	__u64 completed;
+};
+
 #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
 				   struct btrfs_ioctl_vol_args)
 #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -169,4 +174,6 @@ struct btrfs_ioctl_space_args {
 #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, \
+					struct btrfs_ioctl_balance_progress)
 #endif
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 26ef982..69d8613 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -21,6 +21,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem resize\fP\fI [+/\-]<size>[gkm]|max <filesystem>\fP
 .PP
+\fBbtrfs\fP \fBbalance progress\fP \fI<path>\fP
+.PP
 \fBbtrfs\fP \fBdevice scan\fP\fI [<device> [<device>..]]\fP
 .PP
 \fBbtrfs\fP \fBdevice show\fP\fI <dev>|<label> [<dev>|<label>...]\fP
@@ -148,6 +150,11 @@ Balance the chunks of the filesystem identified by \fI<path>\fR
 across the devices.
 .TP
 
+\fBbalance progress\fP \fI<path>\fP
+Report progress on the currently-running balance operation on
+\fI<path>\fP.
+.TP
+
 \fBdevice add\fR\fI <dev> [<dev>..] <path>\fR
 Add device(s) to the filesystem identified by \fI<path>\fR.
 .TP
-- 
1.7.1

[PATCH v2 2/3] Add --monitor option to btrfs balance progress.

[Hugo Mills]

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_cmds.c   |  102 +++++++++++++++++++++++++++++++++++++++++++++++++++----
 man/btrfs.8.in |    4 +-
 2 files changed, 96 insertions(+), 10 deletions(-)

diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index 2745d64..c681b5a 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[1];
+	path = argv[optind];
+	do {
+		int prs = 0;
 
-	ret = get_balance_progress(path, &bal);
-	if (!ret)
-		printf("\r%llu/%llu block groups moved, "
-		       "%0.2f%% complete.\n",
-		       bal.completed,
-		       bal.expected,
-		       (float)bal.completed/bal.expected*100.0);
+		ret = get_balance_progress(path, &bal);
+		if (ret)
+			break;
+
+		if (last_completed != bal.completed) {
+			printf("\r%llu/%llu 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:
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 69d8613..3f7642e 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -21,7 +21,7 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem resize\fP\fI [+/\-]<size>[gkm]|max <filesystem>\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 scan\fP\fI [<device> [<device>..]]\fP
 .PP
@@ -150,7 +150,7 @@ Balance the chunks of the filesystem identified by \fI<path>\fR
 across the devices.
 .TP
 
-\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
 \fI<path>\fP.
 .TP
-- 
1.7.1

[PATCH v2 0/3] Balance management, userspace side

[Hugo Mills]

   These three patches complement the previous two kernel-side
patches. The first implements a way of displaying the current progress
of any running balance process. The second adds a "monitor" mode,
which watches the progress and makes an estimate of the completion
time. The third and final patch allows a running balance to be
cancelled.

Hugo Mills (3):
  Balance progress monitoring.
  Add --monitor option to btrfs balance progress.
  User-space tool for cancelling balance operations.

 btrfs.c        |   12 ++++
 btrfs_cmds.c   |  187 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 btrfs_cmds.h   |    2 +
 ioctl.h        |    8 +++
 man/btrfs.8.in |    7 ++
 5 files changed, 216 insertions(+), 0 deletions(-)