[patch 0/2] Control filesystem balances (userspace)

[patch 0/2] Control filesystem balances (userspace)

[Hugo Mills]

   These two 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 patch allows a running
balance to be cancelled.

   I'm a bit uncertain about the best name for these commands. Several
options:

1)
# btrfs filesystem progress <path>
# btrfs filesystem cancel <path>

   Way too vague (cancel *what*?)


2)
# btrfs filesystem balance-progress <path>
# btrfs filesystem balance-cancel <path>

   Clashes horribly with "filesystem balance" -- no abbreviations
possible.


3)
btrfs filesystem balance -p <path>
btrfs filesystem balance -c <path>

   Changes behaviour significantly on a switch, in contrast to the
behaviour of the rest of the btrfs tool.


4)
btrfs balance progress <path>
btrfs balance cancel <path>

   My current favourite, although we introduce a new namespace
("balance") for commands. We could add "btrfs balance start <path>" as
a synonym for "btrfs filesystem balance <path>", for some degree of
consistency.

   At some point, I'll add a "monitor" function, which will poll at 1s
intervals for progress updates, and print out progress when it changes.

   Hugo.

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
  PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
   --- "No!  My collection of rare, incurable diseases! Violated!" ---   

[patch 1/2] Balance progress monitoring.

[Hugo Mills]

Add support to the btrfs tool for monitoring a balance operation on a
filesystem.

Signed-off-by: Hugo Mills <hugo@carfax.org.uk>

---
 btrfs.c      |    4 ++++
 btrfs_cmds.c |   40 ++++++++++++++++++++++++++++++++++++++++
 btrfs_cmds.h |    1 +
 ioctl.h      |    7 +++++++
 4 files changed, 52 insertions(+)

Index: btrfs-progs-unstable/btrfs.c
===================================================================
--- btrfs-progs-unstable.orig/btrfs.c	2010-10-28 22:58:54.805035975 +0100
+++ btrfs-progs-unstable/btrfs.c	2010-10-30 00:19:59.968416575 +0100
@@ -95,6 +95,10 @@
 	  "filesystem balance", "<path>\n"
 		"Balance the chunks across the device."
 	},
+	{ do_balance_progress, 1,
+	  "balance progress", "<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"
Index: btrfs-progs-unstable/btrfs_cmds.c
===================================================================
--- btrfs-progs-unstable.orig/btrfs_cmds.c	2010-10-28 22:58:54.855033936 +0100
+++ btrfs-progs-unstable/btrfs_cmds.c	2010-10-30 00:04:48.335524683 +0100
@@ -808,6 +808,46 @@
 	}
 	return 0;
 }
+
+int do_balance_progress(int argc, char **argv)
+{
+	char *path = argv[1];
+	int fdmnt;
+	int ret = 0;
+	int err = 0;
+	struct btrfs_ioctl_balance_progress bal;
+
+	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_PROGRESS, &bal);
+	if(!ret)
+		err = errno;
+	close(fdmnt);
+
+	switch(err) {
+	case 0:
+		break;
+	case -EINVAL:
+		fprintf(stderr, "No balance operation running on '%s'.\n",
+			path);
+		return 20;
+	default:
+		fprintf(stderr, "ERROR: ioctl returned error %d.", err);
+		return 21;
+	}
+
+	printf("%llu/%llu block groups moved, %0.2f%% complete.\n",
+	       bal.completed,
+	       bal.expected,
+	       (float)bal.completed/bal.expected*100.0);
+
+	return 0;
+}
+
 int do_remove_volume(int nargs, char **args)
 {
 
Index: btrfs-progs-unstable/btrfs_cmds.h
===================================================================
--- btrfs-progs-unstable.orig/btrfs_cmds.h	2010-10-28 22:58:54.895032304 +0100
+++ btrfs-progs-unstable/btrfs_cmds.h	2010-10-30 00:04:48.335524683 +0100
@@ -23,6 +23,7 @@
 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_remove_volume(int nargs, char **args);
 int do_scan(int nargs, char **argv);
 int do_resize(int nargs, char **argv);
Index: btrfs-progs-unstable/ioctl.h
===================================================================
--- btrfs-progs-unstable.orig/ioctl.h	2010-10-28 23:14:16.937413446 +0100
+++ btrfs-progs-unstable/ioctl.h	2010-10-30 00:04:48.325525089 +0100
@@ -132,6 +132,11 @@
 	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 @@
 #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, 21, \
+					struct btrfs_ioctl_balance_progress)
 #endif

[patch 2/2] 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(+)

Index: btrfs-progs-unstable/btrfs.c
===================================================================
--- btrfs-progs-unstable.orig/btrfs.c	2010-10-30 00:19:59.968416575 +0100
+++ btrfs-progs-unstable/btrfs.c	2010-10-30 00:20:38.446849736 +0100
@@ -99,6 +99,10 @@
 	  "balance progress", "<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"
Index: btrfs-progs-unstable/btrfs_cmds.c
===================================================================
--- btrfs-progs-unstable.orig/btrfs_cmds.c	2010-10-30 00:04:48.335524683 +0100
+++ btrfs-progs-unstable/btrfs_cmds.c	2010-10-30 00:20:22.267508562 +0100
@@ -848,6 +848,47 @@
 	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)
 {
 
Index: btrfs-progs-unstable/btrfs_cmds.h
===================================================================
--- btrfs-progs-unstable.orig/btrfs_cmds.h	2010-10-30 00:04:48.335524683 +0100
+++ btrfs-progs-unstable/btrfs_cmds.h	2010-10-30 00:20:22.307506934 +0100
@@ -24,6 +24,7 @@
 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);
Index: btrfs-progs-unstable/ioctl.h
===================================================================
--- btrfs-progs-unstable.orig/ioctl.h	2010-10-30 00:04:48.325525089 +0100
+++ btrfs-progs-unstable/ioctl.h	2010-10-30 00:20:22.357504895 +0100
@@ -176,4 +176,5 @@
 				    struct btrfs_ioctl_space_args)
 #define BTRFS_IOC_BALANCE_PROGRESS _IOR(BTRFS_IOCTL_MAGIC, 21, \
 					struct btrfs_ioctl_balance_progress)
+#define BTRFS_IOC_BALANCE_CANCEL _IO(BTRFS_IOCTL_MAGIC, 22)
 #endif

Re: [patch 0/2] Control filesystem balances (userspace)

[Jérôme Poulin]

You could always use btrfs filesystem balance progress which would not
introduce a new root level option and still be short to type. That
would mean balance should have a "start" option or default to start
when no sub options are used.

Sent from my mobile device.

On 2010-10-29, at 20:11, Hugo Mills <hugo@carfax.org.uk> wrote:

>   These two 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 patch allows a running
> balance to be cancelled.
>
>   I'm a bit uncertain about the best name for these commands. Several
> options:
>
> 1)
> # btrfs filesystem progress <path>
> # btrfs filesystem cancel <path>
>
>   Way too vague (cancel *what*?)
>
>
> 2)
> # btrfs filesystem balance-progress <path>
> # btrfs filesystem balance-cancel <path>
>
>   Clashes horribly with "filesystem balance" -- no abbreviations
> possible.
>
>
> 3)
> btrfs filesystem balance -p <path>
> btrfs filesystem balance -c <path>
>
>   Changes behaviour significantly on a switch, in contrast to the
> behaviour of the rest of the btrfs tool.
>
>
> 4)
> btrfs balance progress <path>
> btrfs balance cancel <path>
>
>   My current favourite, although we introduce a new namespace
> ("balance") for commands. We could add "btrfs balance start <path>" as
> a synonym for "btrfs filesystem balance <path>", for some degree of
> consistency.
>
>   At some point, I'll add a "monitor" function, which will poll at 1s
> intervals for progress updates, and print out progress when it changes.
>
>   Hugo.
>
> --
> === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
>  PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
>   --- "No!  My collection of rare, incurable diseases! Violated!" ---
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [patch 0/2] Control filesystem balances (userspace)

[Goffredo Baroncelli]

On Saturday, 30 October, 2010, Hugo Mills wrote:
>    These two 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 patch allows a running
> balance to be cancelled.
> 
>    I'm a bit uncertain about the best name for these commands. Several
> options:
> 
[...]
> 
> 4)
> btrfs balance progress <path>
> btrfs balance cancel <path>
> 
>    My current favourite, although we introduce a new namespace
> ("balance") for commands. We could add "btrfs balance start <path>" as
> a synonym for "btrfs filesystem balance <path>", for some degree of
> consistency.

I like this.

Regards
G.Baroncelli
> 
>    At some point, I'll add a "monitor" function, which will poll at 1s
> intervals for progress updates, and print out progress when it changes.
> 
>    Hugo.
> 
> -- 
> === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
>   PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
>    --- "No!  My collection of rare, incurable diseases! Violated!" ---   
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 


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