Add to gpart(8) an ability to backup partition table and

restore it from given backup.

Discussed with:	geom@
Approved by:	kib (mentor)
MFC after:	1 week

2 files changed, 371 insertions, 1 deletions

diff --git a/sbin/geom/class/part/geom_part.c b/sbin/geom/class/part/geom_part.c
index 15bfa0b..55a95e5 100644
--- a/sbin/geom/class/part/geom_part.c
+++ b/sbin/geom/class/part/geom_part.c
@@ -31,6 +31,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/vtoc.h>
 
 #include <assert.h>
+#include <ctype.h>
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -85,6 +86,8 @@ static int gpart_show_hasopt(struct gctl_req *, const char *, const char *);
 static void gpart_write_partcode(struct ggeom *, int, void *, ssize_t);
 static void gpart_write_partcode_vtoc8(struct ggeom *, int, void *);
 static void gpart_print_error(const char *);
+static void gpart_backup(struct gctl_req *, unsigned int);
+static void gpart_restore(struct gctl_req *, unsigned int);
 
 struct g_command PUBSYM(class_commands)[] = {
 	{ "add", 0, gpart_issue, {
@@ -97,6 +100,11 @@ struct g_command PUBSYM(class_commands)[] = {
 		G_OPT_SENTINEL },
 	    "[-b start] [-s size] -t type [-i index] [-l label] [-f flags] geom"
 	},
+	{ "backup", 0, gpart_backup, {
+		{ 'l', "backup_labels", NULL, G_TYPE_BOOL},
+		G_OPT_SENTINEL },
+	    "[-l] geom"
+	},
 	{ "bootcode", 0, gpart_bootcode, {
 		{ 'b', GPART_PARAM_BOOTCODE, G_VAL_OPTIONAL, G_TYPE_STRING },
 		{ 'p', GPART_PARAM_PARTCODE, G_VAL_OPTIONAL, G_TYPE_STRING },
@@ -165,6 +173,12 @@ struct g_command PUBSYM(class_commands)[] = {
 		G_OPT_SENTINEL },
 	    "[-s size] -i index [-f flags] geom"
 	},
+	{ "restore", 0, gpart_restore, {
+		{ 'F', "force", NULL, G_TYPE_BOOL },
+		{ 'f', "flags", GPART_FLAGS, G_TYPE_STRING },
+		G_OPT_SENTINEL },
+	    "[-F] [-f flags] provider [...]"
+	},
 	{ "recover", 0, gpart_issue, {
 		{ 'f', "flags", GPART_FLAGS, G_TYPE_STRING },
 		G_OPT_SENTINEL },
@@ -654,6 +668,295 @@ gpart_show(struct gctl_req *req, unsigned int fl __unused)
 	geom_deletetree(&mesh);
 }
 
+static void
+gpart_backup(struct gctl_req *req, unsigned int fl __unused)
+{
+	struct gmesh mesh;
+	struct gclass *classp;
+	struct gprovider *pp;
+	struct ggeom *gp;
+	const char *s, *scheme;
+	off_t sector, end;
+	off_t length, secsz;
+	int error, labels, i, windex, wblocks, wtype;
+
+	if (gctl_get_int(req, "nargs") != 1)
+		errx(EXIT_FAILURE, "Invalid number of arguments.");
+	error = geom_gettree(&mesh);
+	if (error != 0)
+		errc(EXIT_FAILURE, error, "Cannot get GEOM tree");
+	s = gctl_get_ascii(req, "class");
+	if (s == NULL)
+		abort();
+	classp = find_class(&mesh, s);
+	if (classp == NULL) {
+		geom_deletetree(&mesh);
+		errx(EXIT_FAILURE, "Class %s not found.", s);
+	}
+	s = gctl_get_ascii(req, "arg0");
+	if (s == NULL)
+		abort();
+	labels = gctl_get_int(req, "backup_labels");
+	gp = find_geom(classp, s);
+	if (gp == NULL)
+		errx(EXIT_FAILURE, "No such geom: %s.", s);
+	scheme = find_geomcfg(gp, "scheme");
+	if (scheme == NULL)
+		abort();
+	pp = LIST_FIRST(&gp->lg_consumer)->lg_provider;
+	secsz = pp->lg_sectorsize;
+	s = find_geomcfg(gp, "last");
+	wblocks = strlen(s);
+	wtype = 0;
+	LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
+		s = find_provcfg(pp, "type");
+		i = strlen(s);
+		if (i > wtype)
+			wtype = i;
+	}
+	s = find_geomcfg(gp, "entries");
+	windex = strlen(s);
+	printf("%s %s\n", scheme, s);
+	LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
+		s = find_provcfg(pp, "start");
+		if (s == NULL) {
+			s = find_provcfg(pp, "offset");
+			sector = (off_t)strtoimax(s, NULL, 0) / secsz;
+		} else
+			sector = (off_t)strtoimax(s, NULL, 0);
+
+		s = find_provcfg(pp, "end");
+		if (s == NULL) {
+			s = find_provcfg(pp, "length");
+			length = (off_t)strtoimax(s, NULL, 0) / secsz;
+		} else {
+			end = (off_t)strtoimax(s, NULL, 0);
+			length = end - sector + 1;
+		}
+		s = find_provcfg(pp, "label");
+		printf("%-*s %*s %*jd %*jd",
+		    windex, find_provcfg(pp, "index"),
+		    wtype, find_provcfg(pp, "type"),
+		    wblocks, (intmax_t)sector,
+		    wblocks, (intmax_t)length);
+		if (labels && s != NULL)
+			printf(" %s", s);
+		printf(" %s\n", fmtattrib(pp));
+	}
+	geom_deletetree(&mesh);
+}
+
+static int
+skip_line(const char *p)
+{
+
+	while (*p != '\0') {
+		if (*p == '#')
+			return (1);
+		if (isspace(*p) == 0)
+			return (0);
+		p++;
+	}
+	return (1);
+}
+
+static void
+gpart_restore(struct gctl_req *req, unsigned int fl __unused)
+{
+	struct gmesh mesh;
+	struct gclass *classp;
+	struct gctl_req *r;
+	struct ggeom *gp;
+	const char *s, *flags, *errstr, *label;
+	char **ap, *argv[6], line[BUFSIZ], *pline;
+	int error, forced, i, l, nargs, created;
+	intmax_t n;
+
+	nargs = gctl_get_int(req, "nargs");
+	if (nargs < 1)
+		errx(EXIT_FAILURE, "Invalid number of arguments.");
+
+	forced = gctl_get_int(req, "force");
+	flags = gctl_get_ascii(req, "flags");
+	s = gctl_get_ascii(req, "class");
+	if (s == NULL)
+		abort();
+	error = geom_gettree(&mesh);
+	if (error != 0)
+		errc(EXIT_FAILURE, error, "Cannot get GEOM tree");
+	classp = find_class(&mesh, s);
+	if (classp == NULL) {
+		geom_deletetree(&mesh);
+		errx(EXIT_FAILURE, "Class %s not found.", s);
+	}
+	if (forced) {
+		/* destroy existent partition table before restore */
+		for (i = 0; i < nargs; i++) {
+			s = gctl_get_ascii(req, "arg%d", i);
+			gp = find_geom(classp, s);
+			if (gp != NULL) {
+				r = gctl_get_handle();
+				gctl_ro_param(r, "class", -1,
+				    classp->lg_name);
+				gctl_ro_param(r, "verb", -1, "destroy");
+				gctl_ro_param(r, "flags", -1, "restore");
+				gctl_ro_param(r, "force", sizeof(forced),
+				    &forced);
+				gctl_ro_param(r, "arg0", -1, s);
+				errstr = gctl_issue(r);
+				if (errstr != NULL && errstr[0] != '\0') {
+					gpart_print_error(errstr);
+					gctl_free(r);
+					goto backout;
+				}
+				gctl_free(r);
+			}
+		}
+	}
+	created = 0;
+	while (fgets(line, sizeof(line) - 1, stdin)) {
+		/* Format of backup entries:
+		 * <scheme name> <number of entries>
+		 * <index> <type> <start> <size> [label] ['['attrib[,attrib]']']
+		 */
+		pline = (char *)line;
+		pline[strlen(line) - 1] = 0;
+		if (skip_line(pline))
+			continue;
+		for (ap = argv;
+		    (*ap = strsep(&pline, " \t")) != NULL;)
+			if (**ap != '\0' && ++ap >= &argv[6])
+				break;
+		l = ap - &argv[0];
+		label = pline = NULL;
+		if (l == 2) { /* create table */
+			if (created)
+				errx(EXIT_FAILURE, "Incorrect backup format.");
+			n = atoi(argv[1]);
+			for (i = 0; i < nargs; i++) {
+				s = gctl_get_ascii(req, "arg%d", i);
+				r = gctl_get_handle();
+				n = strtoimax(argv[1], NULL, 0);
+				gctl_ro_param(r, "class", -1,
+				    classp->lg_name);
+				gctl_ro_param(r, "verb", -1, "create");
+				gctl_ro_param(r, "scheme", -1, argv[0]);
+				gctl_ro_param(r, "entries", sizeof(n), &n);
+				gctl_ro_param(r, "flags", -1, "restore");
+				gctl_ro_param(r, "arg0", -1, s);
+				errstr = gctl_issue(r);
+				if (errstr != NULL && errstr[0] != '\0') {
+					gpart_print_error(errstr);
+					gctl_free(r);
+					goto backout;
+				}
+				gctl_free(r);
+			}
+			created = 1;
+			continue;
+		} else if (l < 4 || created == 0)
+			errx(EXIT_FAILURE, "Incorrect backup format.");
+		else if (l == 5) {
+			if (strchr(argv[4], '[') == NULL)
+				label = argv[4];
+			else
+				pline = argv[4];
+		} else if (l == 6) {
+			label = argv[4];
+			pline = argv[5];
+		}
+		/* Add partitions to each table */
+		for (i = 0; i < nargs; i++) {
+			s = gctl_get_ascii(req, "arg%d", i);
+			r = gctl_get_handle();
+			n = strtoimax(argv[0], NULL, 0);
+			gctl_ro_param(r, "class", -1, classp->lg_name);
+			gctl_ro_param(r, "verb", -1, "add");
+			gctl_ro_param(r, "flags", -1, "restore");
+			gctl_ro_param(r, GPART_PARAM_INDEX, sizeof(n), &n);
+			gctl_ro_param(r, "type", -1, argv[1]);
+			gctl_ro_param(r, "start", -1, argv[2]);
+			gctl_ro_param(r, "size", -1, argv[3]);
+			if (label != NULL)
+				gctl_ro_param(r, "label", -1, argv[4]);
+			gctl_ro_param(r, "arg0", -1, s);
+			error = gpart_autofill(r);
+			if (error != 0)
+				errc(EXIT_FAILURE, error, "autofill");
+			errstr = gctl_issue(r);
+			if (errstr != NULL && errstr[0] != '\0') {
+				gpart_print_error(errstr);
+				gctl_free(r);
+				goto backout;
+			}
+			gctl_free(r);
+		}
+		if (pline == NULL || *pline != '[')
+			continue;
+		/* set attributes */
+		pline++;
+		for (ap = argv;
+		    (*ap = strsep(&pline, ",]")) != NULL;)
+			if (**ap != '\0' && ++ap >= &argv[6])
+				break;
+		for (i = 0; i < nargs; i++) {
+			l = ap - &argv[0];
+			s = gctl_get_ascii(req, "arg%d", i);
+			while (l > 0) {
+				r = gctl_get_handle();
+				gctl_ro_param(r, "class", -1, classp->lg_name);
+				gctl_ro_param(r, "verb", -1, "set");
+				gctl_ro_param(r, "flags", -1, "restore");
+				gctl_ro_param(r, GPART_PARAM_INDEX,
+				    sizeof(n), &n);
+				gctl_ro_param(r, "attrib", -1, argv[--l]);
+				gctl_ro_param(r, "arg0", -1, s);
+				errstr = gctl_issue(r);
+				if (errstr != NULL && errstr[0] != '\0') {
+					gpart_print_error(errstr);
+					gctl_free(r);
+					goto backout;
+				}
+				gctl_free(r);
+			}
+		}
+	}
+	/* commit changes if needed */
+	if (strchr(flags, 'C') != NULL) {
+		for (i = 0; i < nargs; i++) {
+			s = gctl_get_ascii(req, "arg%d", i);
+			r = gctl_get_handle();
+			gctl_ro_param(r, "class", -1, classp->lg_name);
+			gctl_ro_param(r, "verb", -1, "commit");
+			gctl_ro_param(r, "arg0", -1, s);
+			errstr = gctl_issue(r);
+			if (errstr != NULL && errstr[0] != '\0') {
+				gpart_print_error(errstr);
+				gctl_free(r);
+				goto backout;
+			}
+			gctl_free(r);
+		}
+	}
+	gctl_free(req);
+	geom_deletetree(&mesh);
+	exit(EXIT_SUCCESS);
+
+backout:
+	for (i = 0; i < nargs; i++) {
+		s = gctl_get_ascii(req, "arg%d", i);
+		r = gctl_get_handle();
+		gctl_ro_param(r, "class", -1, classp->lg_name);
+		gctl_ro_param(r, "verb", -1, "undo");
+		gctl_ro_param(r, "arg0", -1, s);
+		gctl_issue(r);
+		gctl_free(r);
+	}
+	gctl_free(req);
+	geom_deletetree(&mesh);
+	exit(EXIT_FAILURE);
+}
+
 static void *
 gpart_bootfile_read(const char *bootfile, ssize_t *size)
 {
diff --git a/sbin/geom/class/part/gpart.8 b/sbin/geom/class/part/gpart.8
index f01e56a..ef303bf 100644
--- a/sbin/geom/class/part/gpart.8
+++ b/sbin/geom/class/part/gpart.8
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 25, 2010
+.Dd November 20, 2010
 .Dt GPART 8
 .Os
 .Sh NAME
@@ -91,6 +91,11 @@ utility:
 .Op Fl l Ar label
 .Op Fl f Ar flags
 .Ar geom
+.\" ==== BACKUP ====
+.Nm
+.Cm backup
+.Op Fl l
+.Ar geom
 .\" ==== BOOTCODE ====
 .Nm
 .Cm bootcode
@@ -141,6 +146,13 @@ utility:
 .Op Fl s Ar size
 .Op Fl f Ar flags
 .Ar geom
+.\" ==== RESTORE ====
+.Nm
+.Cm restore
+.Op Fl F
+.Op Fl f Ar flags
+.Ar provider
+.Op Ar ...
 .\" ==== SET ====
 .Nm
 .Cm set
@@ -208,6 +220,17 @@ See the section entitled
 below for a discussion
 about its use.
 .El
+.\" ==== BACKUP ====
+.It Cm backup
+Dump a partition table to standard output in special format used by
+.Cm restore
+action.
+.Pp
+Additional options include:
+.Bl -tag -width 10n
+.It Fl l
+Dump partition labels for partitioning schemes that support them.
+.El
 .\" ==== BOOTCODE ====
 .It Cm bootcode
 Embed bootstrap code into the partitioning scheme's metadata on the
@@ -401,6 +424,28 @@ See the section entitled
 below for a discussion
 about its use.
 .El
+.\" ==== RESTORE ====
+.It Cm restore
+Restore the partition table from backup previously created by
+.Cm backup
+action and given from standard input. Only partition table
+may be restored. This action does not affect content of partitions.
+This mean that you should copy your data from backup after restoring
+partition table and write bootcode again if it is needed. 
+.Pp
+Additional options include:
+.Bl -tag -width 10n
+.It Fl F
+Destroy partition table on the given
+.Ar provider
+before doing restore.
+.It Fl f Ar flags
+Additional operational flags.
+See the section entitled
+.Sx "OPERATIONAL FLAGS"
+below for a discussion
+about its use.
+.El
 .\" ==== SET ====
 .It Cm set
 Set the named attribute on the partition entry.
@@ -770,6 +815,28 @@ After having created all required partitions, embed bootstrap code into them.
 .Bd -literal -offset indent
 /sbin/gpart bootcode -p /boot/boot1 da0
 .Ed
+.Pp
+Create backup of partition table from
+.Pa da0
+.Bd -literal -offset indent
+/sbin/gpart backup -l da0 > da0.backup
+.Ed
+.Pp
+Restore partition table from backup to
+.Pa da0
+.Bd -literal -offset indent
+/sbin/gpart restore da0 < /mnt/da0.backup
+.Ed
+.Pp
+Clone partition table from 
+.Pa ada0 
+to 
+.Pa ada1 
+and 
+.Pa ada2
+.Bd -literal -offset indent
+/sbin/gpart backup ada0 | /sbin/gpart restore -F ada1 ada2
+.Ed
 .Sh SEE ALSO
 .Xr dd 1 ,
 .Xr geom 4 ,