Patch to allow gmirror to set priority of a disk

[Mel Flynn]

On Thursday 03 September 2009 15:57:41 Pawel Jakub Dawidek wrote:
> On Thu, Sep 03, 2009 at 03:48:37PM +0200, Mel Flynn wrote:
> > On Thursday 03 September 2009 14:44:07 Pawel Jakub Dawidek wrote:
> > > I'd suggest doing this not as separate gmirror(8) subcommand, but as an
> > > extension to 'configure' subcommand, where one can provide priority by
> > > giving '-p' argument.
> >
> > Except I didn't see how configure was implemented. Am I correct that this
> > is g_mirror_ctl_configure in sys/geom/mirror/g_mirror_ctl.c?
>
> Yes, you are correct.

Ok, new patch. I gathered from configure_slice, that my assumption was about 
flag handling is correct. Patch is only compile tested.
-- 
Mel
-------------- next part --------------
Index: sbin/geom/class/mirror/geom_mirror.c
===================================================================
--- sbin/geom/class/mirror/geom_mirror.c	(revision 196803)
+++ sbin/geom/class/mirror/geom_mirror.c	(working copy)
@@ -47,7 +47,7 @@
 
 static char label_balance[] = "split", configure_balance[] = "none";
 static intmax_t label_slice = 4096, configure_slice = -1;
-static intmax_t insert_priority = 0;
+static intmax_t insert_priority = 0, configure_priority = -1;
 
 static void mirror_main(struct gctl_req *req, unsigned flags);
 static void mirror_activate(struct gctl_req *req);
@@ -71,10 +71,11 @@
 		{ 'F', "nofailsync", NULL, G_TYPE_BOOL },
 		{ 'h', "hardcode", NULL, G_TYPE_BOOL },
 		{ 'n', "noautosync", NULL, G_TYPE_BOOL },
+		{ 'p', "priority", &configure_priority, G_TYPE_NUMBER },
 		{ 's', "slice", &configure_slice, G_TYPE_NUMBER },
 		G_OPT_SENTINEL
 	    },
-	    NULL, "[-adfFhnv] [-b balance] [-s slice] name"
+	    NULL, "[-adfFhnv] [-b balance] [-s slice]  [-p prio] name [prov]"
 	},
 	{ "deactivate", G_FLAG_VERBOSE, NULL, G_NULL_OPTS, NULL,
 	    "[-v] name prov ..."
Index: sbin/geom/class/mirror/gmirror.8
===================================================================
--- sbin/geom/class/mirror/gmirror.8	(revision 196803)
+++ sbin/geom/class/mirror/gmirror.8	(working copy)
@@ -47,7 +47,9 @@
 .Op Fl adfFhnv
 .Op Fl b Ar balance
 .Op Fl s Ar slice
+.Op Fl p Ar priority
 .Ar name
+.Op Ar prov
 .Nm
 .Cm rebuild
 .Op Fl v
@@ -115,8 +117,8 @@
 .It Cm label
 Create a mirror.
 The order of components is important, because a component's priority is based on its position
-(starting from 0).
-The component with the biggest priority is used by the
+(starting from 0 to 255).
+The component with the biggest priority (the lowest number) is used by the
 .Cm prefer
 balance algorithm
 and is also used as a master component when resynchronization is needed,
@@ -175,6 +177,9 @@
 Hardcode providers' names in metadata.
 .It Fl n
 Turn off autosynchronization of stale components.
+.It Fl p Ar priority
+Specify priority for given
+.Ar prov
 .It Fl s Ar slice
 Specifies slice size for
 .Cm split
Index: sys/geom/mirror/g_mirror_ctl.c
===================================================================
--- sys/geom/mirror/g_mirror_ctl.c	(revision 196803)
+++ sys/geom/mirror/g_mirror_ctl.c	(working copy)
@@ -93,12 +93,12 @@
 {
 	struct g_mirror_softc *sc;
 	struct g_mirror_disk *disk;
-	const char *name, *balancep;
+	const char *name, *balancep, *prov;
 	intmax_t *slicep;
 	uint32_t slice;
 	uint8_t balance;
 	int *autosync, *noautosync, *failsync, *nofailsync, *hardcode, *dynamic;
-	int *nargs, do_sync = 0, dirty = 1;
+	int *nargs, *priority, do_sync = 0, dirty = 1, do_priority = 0;
 
 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
 	if (nargs == NULL) {
@@ -149,6 +149,27 @@
 		gctl_error(req, "No '%s' argument.", "dynamic");
 		return;
 	}
+	priority = gctl_get_paraml(req, "priority", sizeof(*priority));
+	if (priority == NULL ) {
+		gctl_error(req, "No '%s' argument.", "priority");
+		return;
+	}
+	if( *priority < -1 || *priority > 255 ) {
+		gctl_error(req, "Priority range is 0 to 255, %i given",
+		    *priority);
+		return;
+	}
+	/* Since we have a priority, we also need a provider now.
+	 * Note: be WARNS safe, by always assigning prov and only throw an
+	 * error if *priority != -1. */
+	prov = gctl_get_asciiparam(req, "arg1");
+	if( *priority > -1 ) {
+		if( prov == NULL ) {
+			gctl_error(req, "Priority needs a disk name");
+			return;
+		}
+		do_priority = 1;
+	}
 	if (*autosync && *noautosync) {
 		gctl_error(req, "'%s' and '%s' specified.", "autosync",
 		    "noautosync");
@@ -233,6 +254,11 @@
 			disk->d_flags &= ~G_MIRROR_DISK_FLAG_HARDCODED;
 		if (!dirty)
 			disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
+		if (do_priority) {
+			if (strcmp(disk->d_name, prov) == 0) {
+				disk->d_priority = *priority;
+			}
+		}
 		g_mirror_update_metadata(disk);
 		if (do_sync) {
 			if (disk->d_state == G_MIRROR_DISK_STATE_STALE) {