illumos gate

diff --git a/usr/src/cmd/zpool/zpool_main.c b/usr/src/cmd/zpool/zpool_main.c

index 82b9672..4edf541 100644

--- a/usr/src/cmd/zpool/zpool_main.c

+++ b/usr/src/cmd/zpool/zpool_main.c

@@ -36,6 +36,7 @@

 #include <libgen.h>

 #include <libintl.h>

 #include <libuutil.h>

+#include <limits.h>

 #include <locale.h>

 #include <stdio.h>

 #include <stdlib.h>

@@ -47,6 +48,7 @@

 #include <zone.h>

 #include <zfs_prop.h>

 #include <sys/fs/zfs.h>

+#include <sys/vdev_impl.h>

 #include <sys/stat.h>

 #include <libzfs.h>

@@ -233,7 +235,8 @@ get_usage(zpool_help_t idx)

 		return (gettext("\tiostat [-v] [-T d|u] [pool] ... [interval "

 		    "[count]]\n"));

 	case HELP_LABELCLEAR:

-		return (gettext("\tlabelclear [-f] <vdev>\n"));

+		return (gettext("\tlabelclear [-b | -e | -i index] [-c] [-m] "

+		    "[-f] <vdev>\n"));

 	case HELP_LIST:

 		return (gettext("\tlist [-Hp] [-o property[,...]] "

 		    "[-T d|u] [pool] ... [interval [count]]\n"));

@@ -643,10 +646,40 @@ zpool_do_labelclear(int argc, char **argv)

 	pool_state_t state;

 	boolean_t inuse = B_FALSE;

 	boolean_t force = B_FALSE;

+	boolean_t check = B_FALSE;

+	boolean_t cherry = B_FALSE;

+	unsigned int start = 0, n = VDEV_LABELS;

+	char *end = NULL;

+	long long index = 0;

 	/* check options */

-	while ((c = getopt(argc, argv, "f")) != -1) {

+	while ((c = getopt(argc, argv, "bei:cmf")) != -1) {

 		switch (c) {

+		case 'b':

+			start = 0;

+			n = VDEV_LABELS / 2;

+			break;

+		case 'e':

+			start = VDEV_LABELS / 2;

+			n = VDEV_LABELS / 2;

+			break;

+		case 'i':

+			index = strtoll(optarg, &end, 10);

+			if((end == optarg) || (*end != '\0') ||

+			    (index < 0) || (index >= VDEV_LABELS)) {

+				(void) fprintf(stderr, 

+				    gettext("Invalid index value provided\n"));

+				return (1);

+			}

+			start = (unsigned int)index;

+			n = 1;

+			break;

+		case 'c':

+			check = B_TRUE;

+			break;

+		case 'm':

+			cherry = B_TRUE;

+			break;

 		case 'f':

 			force = B_TRUE;

 			break;

@@ -699,8 +732,12 @@ zpool_do_labelclear(int argc, char **argv)

 	}

 	if (zpool_read_label(fd, &config) != 0 || config == NULL) {

-		(void) fprintf(stderr,

-		    gettext("failed to read label from %s\n"), vdev);

+		if (force)

+			goto wipe_label;

+		(void) fprintf(stderr, gettext(

+		    "use '-f' to override the following error:\n"

+		    "failed to read label from \"%s\"\n"),

+		     vdev);

 		return (1);

 	}

 	nvlist_free(config);

@@ -753,7 +790,7 @@ zpool_do_labelclear(int argc, char **argv)

 	}

 wipe_label:

-	ret = zpool_clear_label(fd);

+	ret = zpool_clear_n_labels(fd, start, n, check, cherry);

 	if (ret != 0) {

 		(void) fprintf(stderr,

 		    gettext("failed to clear label for %s\n"), vdev);

diff --git a/usr/src/common/nvpair/nvpair.c b/usr/src/common/nvpair/nvpair.c

index 2c1bcfa..36dc02b 100644

--- a/usr/src/common/nvpair/nvpair.c

+++ b/usr/src/common/nvpair/nvpair.c

@@ -2353,6 +2353,18 @@ nvlist_common(nvlist_t *nvl, char *buf, size_t *buflen, int encoding,

 }

 int

+nvlist_invalidate(char *buf)

+{

+	if (buf == NULL)

+		return (EINVAL);

+

+	nvs_header_t *nvh = (void *)buf;

+	nvh->nvh_encoding = NV_ENCODE_INVALID;

+

+	return (0);

+}

+

+int

 nvlist_size(nvlist_t *nvl, size_t *size, int encoding)

 {

 	return (nvlist_common(nvl, NULL, size, encoding, NVS_OP_GETSIZE));

diff --git a/usr/src/lib/libzfs/common/libzfs.h b/usr/src/lib/libzfs/common/libzfs.h

index 9baff24..022634f 100644

--- a/usr/src/lib/libzfs/common/libzfs.h

+++ b/usr/src/lib/libzfs/common/libzfs.h

@@ -746,6 +746,7 @@ extern int zpool_in_use(libzfs_handle_t *, int, pool_state_t *, char **,

  * Label manipulation.

  */

 extern int zpool_read_label(int, nvlist_t **);

+extern int zpool_clear_n_labels(int, unsigned int, unsigned int, boolean_t, boolean_t);

 extern int zpool_clear_label(int);

 /* is this zvol valid for use as a dump device? */

diff --git a/usr/src/lib/libzfs/common/libzfs_import.c b/usr/src/lib/libzfs/common/libzfs_import.c

index b73a71e..87aac2c 100644

--- a/usr/src/lib/libzfs/common/libzfs_import.c

+++ b/usr/src/lib/libzfs/common/libzfs_import.c

@@ -1084,36 +1084,68 @@ zpool_open_func(void *arg)

 }

 /*

- * Given a file descriptor, clear (zero) the label information.

+ * Given a file descriptor, a starting label and a number of labels to clear,

+ * clear (zero) the label information.

  */

 int

-zpool_clear_label(int fd)

+zpool_clear_n_labels(int fd, unsigned int start, unsigned int n,

+    boolean_t check, boolean_t cherry)

 {

 	struct stat64 statbuf;

-	int l;

-	vdev_label_t *label;

+	unsigned int l, end;

+	vdev_label_t label;

 	uint64_t size;

+	char *buf = label.vl_vdev_phys.vp_nvlist;

+	size_t buflen = sizeof (label.vl_vdev_phys.vp_nvlist);

+

 	if (fstat64(fd, &statbuf) == -1)

 		return (0);

 	size = P2ALIGN_TYPED(statbuf.st_size, sizeof (vdev_label_t), uint64_t);

-	if ((label = calloc(sizeof (vdev_label_t), 1)) == NULL)

+	end = start + n;

+	if (end > VDEV_LABELS)

 		return (-1);

-	for (l = 0; l < VDEV_LABELS; l++) {

-		if (pwrite64(fd, label, sizeof (vdev_label_t),

-		    label_offset(size, l)) != sizeof (vdev_label_t)) {

-			free(label);

-			return (-1);

+	for (l = start; l < end; l++) {

+		if ((check == B_TRUE) || (cherry == B_TRUE)) {

+			if (pread64(fd, &label, sizeof (vdev_label_t),

+			    label_offset(size, l)) != sizeof (vdev_label_t))

+				return (-1);

+ 

+			if (check == B_TRUE) {

+				nvlist_t *config = NULL;

+				if (nvlist_unpack(buf, buflen, &config, 0) != 0)

+					return (-1);

+				nvlist_free(config);

+			}

+		}

+ 

+		if (cherry == B_TRUE) {

+			if (nvlist_invalidate(buf) != 0)

+				return (-1);

+		} else {

+			memset(&label, 0, sizeof (vdev_label_t));

 		}

+ 

+		if (pwrite64(fd, &label, sizeof (vdev_label_t),

+		    label_offset(size, l)) != sizeof (vdev_label_t))

+			return (-1);

 	}

-	free(label);

 	return (0);

 }

 /*

+ * Given a file descriptor, clear (zero) the label information.

+ */

+int

+zpool_clear_label(int fd)

+{

+	return (zpool_clear_n_labels(fd, 0, VDEV_LABELS, B_FALSE, B_FALSE));

+}

+

+/*

  * Given a list of directories to search, find all pools stored on disk.  This

  * includes partial pools which are not available to import.  If no args are

  * given (argc is 0), then the default directory (/dev/dsk) is searched.

diff --git a/usr/src/man/man1m/zpool.1m b/usr/src/man/man1m/zpool.1m

index eadb548..fc20f5c 100644

--- a/usr/src/man/man1m/zpool.1m

+++ b/usr/src/man/man1m/zpool.1m

@@ -104,6 +104,9 @@

 .Op Ar interval Op Ar count

 .Nm

 .Cm labelclear

+.Op Fl b | Fl e | Fl i Ar index

+.Op Fl c

+.Op Fl m

 .Op Fl f

 .Ar device

 .Nm

@@ -1159,6 +1162,9 @@ pool, in addition to the pool-wide statistics.

 .It Xo

 .Nm

 .Cm labelclear

+.Op Fl b | Fl e | Fl i Ar index

+.Op Fl c

+.Op Fl m

 .Op Fl f

 .Ar device

 .Xc

@@ -1166,8 +1172,29 @@ Removes ZFS label information from the specified

 .Ar device .

 The

 .Ar device

-must not be part of an active pool configuration.

+must not be part of an active pool configuration. Options

+.Fl b ,

+.Fl e

+and

+.Fl i

+can be used for clearing specific labels. They are mutually exclusive and the

+last one will supersede others, if any.

 .Bl -tag -width Ds

+.It Fl b

+Only remove ZFS labels located at the beginning of

+.Ar device .

+.It Fl e

+Only remove ZFS labels located at the end of

+.Ar device .

+.It Fl i Ar index

+Remove a single label entry located at position

+.Ar index .

+.It Fl c

+Check label integrity before doing anything.

+.It Fl m

+Perform minimal operation needed to invalidate a label instead of blindly

+erasing every single byte. This reduces (but does not annihilate) the risks of

+overriding important on-disk data.

 .It Fl f

 Treat exported or foreign devices as inactive.

 .El

diff --git a/usr/src/uts/common/sys/nvpair.h b/usr/src/uts/common/sys/nvpair.h

index e4d637b..36f2dd4 100644

--- a/usr/src/uts/common/sys/nvpair.h

+++ b/usr/src/uts/common/sys/nvpair.h

@@ -98,6 +98,7 @@ typedef struct nvlist {

 #define	NV_VERSION	0

 /* nvlist pack encoding */

+#define	NV_ENCODE_INVALID	(-1)

 #define	NV_ENCODE_NATIVE	0

 #define	NV_ENCODE_XDR		1

@@ -153,6 +154,7 @@ void nv_alloc_fini(nv_alloc_t *);

 /* list management */

 int nvlist_alloc(nvlist_t **, uint_t, int);

 void nvlist_free(nvlist_t *);

+int nvlist_invalidate(char *);

 int nvlist_size(nvlist_t *, size_t *, int);

 int nvlist_pack(nvlist_t *, char **, size_t *, int, int);

 int nvlist_unpack(char *, size_t, nvlist_t **, int);