Add pool prop partition to disable auto partition

zfsonlinux always partition disk when it detects the device given is a
whole disk. This legacy behavior from Illumos, however, has no apparent
benefit on Linux, but has some down sides besides confusion. E.g.
autoexpand, switching to dm device requires partprobe.

We add a pool property `partition` to be set during pool create. It
currently has two values, legacy and raw. When setting it to legacy, it
will behave as it did. When setiing it to raw, it will always use the
device as is without partitioning even if it's a whole disk.

This property applies to all commands that add disks to pool, so zpool
add/attach/replace will partition or not partition based on the property
on the target pool.

A pool without this property will be treated as legacy. Newly created
pool will by default have partition=raw.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>

cmd/zpool/zpool_main.c

@@ -1107,6 +1107,11 @@ zpool_do_create(int argc, char **argv)
 		}
 	}
 
+	/* Make new pools default to partition=raw */
+	if (add_prop_list_default(zpool_prop_to_name(ZPOOL_PROP_PARTITION),
+	    "raw", &props, B_TRUE))
+		goto errout;
+
 	argc -= optind;
 	argv += optind;
 

cmd/zpool/zpool_vdev.c

@@ -1188,29 +1188,47 @@ zero_label(char *path)
  * need to get the devid after we label the disk.
  */
 static int
-make_disks(zpool_handle_t *zhp, nvlist_t *nv)
+make_disks(zpool_handle_t *zhp, nvlist_t *props, nvlist_t *nv)
 {
 	nvlist_t **child;
 	uint_t c, children;
 	char *type, *path;
 	char devpath[MAXPATHLEN];
 	char udevpath[MAXPATHLEN];
 	uint64_t wholedisk;
+	uint64_t part = ZPOOL_PARTITION_LEGACY;
 	struct stat64 statbuf;
 	int is_exclusive = 0;
 	int fd;
 	int ret;
 
 	verify(nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) == 0);
 
+	/*
+	 * Find out the partition type. If zhp exists, this is an existing
+	 * pool, get it from pool property. Otherwise, this is pool creation,
+	 * get it from cmdline from props.
+	 */
+	if (zhp)
+		part = zpool_get_prop_int(zhp, ZPOOL_PROP_PARTITION, NULL);
+	else if (props) {
+		char *strval;
+		uint64_t index;
+		if (nvlist_lookup_string(props,
+		    zpool_prop_to_name(ZPOOL_PROP_PARTITION), &strval) == 0 &&
+		    zpool_prop_string_to_index(ZPOOL_PROP_PARTITION, strval,
+		    &index) == 0)
+			part = index;
+	}
+
 	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
 	    &child, &children) != 0) {
 
 		if (strcmp(type, VDEV_TYPE_DISK) != 0)
 			return (0);
 
 		/*
-		 * We have a disk device.  If this is a whole disk write
+		 * We have a disk device.  If this is a legacy whole disk write
 		 * out the efi partition table, otherwise write zero's to
 		 * the first 4k of the partition.  This is to ensure that
 		 * libblkid will not misidentify the partition due to a
@@ -1220,14 +1238,15 @@ make_disks(zpool_handle_t *zhp, nvlist_t *nv)
 		verify(!nvlist_lookup_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK,
 		    &wholedisk));
 
-		if (!wholedisk) {
+		if (!wholedisk || part == ZPOOL_PARTITION_RAW) {
 			/*
 			 * Update device id string for mpath nodes (Linux only)
 			 */
-			if (is_mpath_whole_disk(path))
+			if (wholedisk || is_mpath_whole_disk(path))
 				update_vdev_config_dev_strs(nv);
 
-			(void) zero_label(path);
+			if (!is_spare(NULL, path))
+				(void) zero_label(path);
 			return (0);
 		}
 
@@ -1318,19 +1337,19 @@ make_disks(zpool_handle_t *zhp, nvlist_t *nv)
 	}
 
 	for (c = 0; c < children; c++)
-		if ((ret = make_disks(zhp, child[c])) != 0)
+		if ((ret = make_disks(zhp, props, child[c])) != 0)
 			return (ret);
 
 	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_SPARES,
 	    &child, &children) == 0)
 		for (c = 0; c < children; c++)
-			if ((ret = make_disks(zhp, child[c])) != 0)
+			if ((ret = make_disks(zhp, props, child[c])) != 0)
 				return (ret);
 
 	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_L2CACHE,
 	    &child, &children) == 0)
 		for (c = 0; c < children; c++)
-			if ((ret = make_disks(zhp, child[c])) != 0)
+			if ((ret = make_disks(zhp, props, child[c])) != 0)
 				return (ret);
 
 	return (0);
@@ -1341,8 +1360,8 @@ make_disks(zpool_handle_t *zhp, nvlist_t *nv)
  * the majority of this task.
  */
 static boolean_t
-is_device_in_use(nvlist_t *config, nvlist_t *nv, boolean_t force,
-    boolean_t replacing, boolean_t isspare)
+is_device_in_use(zpool_handle_t *zhp, nvlist_t *config, nvlist_t *nv,
+    boolean_t force, boolean_t replacing, boolean_t isspare)
 {
 	nvlist_t **child;
 	uint_t c, children;
@@ -1368,8 +1387,13 @@ is_device_in_use(nvlist_t *config, nvlist_t *nv, boolean_t force,
 		 * regardless of what libblkid or zpool_in_use() says.
 		 */
 		if (replacing) {
+			uint64_t part = ZPOOL_PARTITION_LEGACY;
+			if (zhp)
+				part = zpool_get_prop_int(zhp,
+				    ZPOOL_PROP_PARTITION, NULL);
+
 			(void) strlcpy(buf, path, sizeof (buf));
-			if (wholedisk) {
+			if (wholedisk && part == ZPOOL_PARTITION_LEGACY) {
 				ret = zfs_append_partition(buf,  sizeof (buf));
 				if (ret == -1)
 					return (-1);
@@ -1389,22 +1413,22 @@ is_device_in_use(nvlist_t *config, nvlist_t *nv, boolean_t force,
 	}
 
 	for (c = 0; c < children; c++)
-		if (is_device_in_use(config, child[c], force, replacing,
+		if (is_device_in_use(zhp, config, child[c], force, replacing,
 		    B_FALSE))
 			anyinuse = B_TRUE;
 
 	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_SPARES,
 	    &child, &children) == 0)
 		for (c = 0; c < children; c++)
-			if (is_device_in_use(config, child[c], force, replacing,
-			    B_TRUE))
+			if (is_device_in_use(zhp, config, child[c], force,
+			    replacing, B_TRUE))
 				anyinuse = B_TRUE;
 
 	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_L2CACHE,
 	    &child, &children) == 0)
 		for (c = 0; c < children; c++)
-			if (is_device_in_use(config, child[c], force, replacing,
-			    B_FALSE))
+			if (is_device_in_use(zhp, config, child[c], force,
+			    replacing, B_FALSE))
 				anyinuse = B_TRUE;
 
 	return (anyinuse);
@@ -1705,7 +1729,7 @@ split_mirror_vdev(zpool_handle_t *zhp, char *newname, nvlist_t *props,
 			return (NULL);
 		}
 
-		if (!flags.dryrun && make_disks(zhp, newroot) != 0) {
+		if (!flags.dryrun && make_disks(zhp, props, newroot) != 0) {
 			nvlist_free(newroot);
 			return (NULL);
 		}
@@ -1774,7 +1798,8 @@ make_root_vdev(zpool_handle_t *zhp, nvlist_t *props, int force, int check_rep,
 	 * uses (such as a dedicated dump device) that even '-f' cannot
 	 * override.
 	 */
-	if (is_device_in_use(poolconfig, newroot, force, replacing, B_FALSE)) {
+	if (is_device_in_use(zhp, poolconfig, newroot, force, replacing,
+	    B_FALSE)) {
 		nvlist_free(newroot);
 		return (NULL);
 	}
@@ -1792,7 +1817,7 @@ make_root_vdev(zpool_handle_t *zhp, nvlist_t *props, int force, int check_rep,
 	/*
 	 * Run through the vdev specification and label any whole disks found.
 	 */
-	if (!dryrun && make_disks(zhp, newroot) != 0) {
+	if (!dryrun && make_disks(zhp, props, newroot) != 0) {
 		nvlist_free(newroot);
 		return (NULL);
 	}

include/sys/fs/zfs.h

@@ -221,6 +221,7 @@ typedef enum {
 	ZPOOL_PROP_MAXBLOCKSIZE,
 	ZPOOL_PROP_TNAME,
 	ZPOOL_PROP_MAXDNODESIZE,
+	ZPOOL_PROP_PARTITION,
 	ZPOOL_NUM_PROPS
 } zpool_prop_t;
 
@@ -819,6 +820,11 @@ typedef enum zpool_errata {
 	ZPOOL_ERRATA_ZOL_2094_ASYNC_DESTROY,
 } zpool_errata_t;
 
+enum zpool_part {
+	ZPOOL_PARTITION_LEGACY = 0,
+	ZPOOL_PARTITION_RAW,
+};
+
 /*
  * Vdev statistics.  Note: all fields should be 64-bit because this
  * is passed between kernel and userland as an nvlist uint64 array.

lib/libzfs/libzfs_pool.c

@@ -1949,8 +1949,8 @@ zpool_scan(zpool_handle_t *zhp, pool_scan_func_t func)
  * spare; but FALSE if its an INUSE spare.
  */
 static nvlist_t *
-vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
-    boolean_t *l2cache, boolean_t *log)
+vdev_to_nvlist_iter(zpool_handle_t *zhp, nvlist_t *nv, nvlist_t *search,
+    boolean_t *avail_spare, boolean_t *l2cache, boolean_t *log)
 {
 	uint_t c, children;
 	nvlist_t **child;
@@ -1989,8 +1989,8 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 		/*
 		 * Search for the requested value. Special cases:
 		 *
-		 * - ZPOOL_CONFIG_PATH for whole disk entries.  These end in
-		 *   "-part1", or "p1".  The suffix is hidden from the user,
+		 * - ZPOOL_CONFIG_PATH for legacy whole disk entries.  These end
+		 *   in "-part1", or "p1".  The suffix is hidden from the user,
 		 *   but included in the string, so this matches around it.
 		 * - ZPOOL_CONFIG_PATH for short names zfs_strcmp_shortname()
 		 *   is used to check all possible expanded paths.
@@ -2000,10 +2000,17 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 		 */
 		if (strcmp(srchkey, ZPOOL_CONFIG_PATH) == 0) {
 			uint64_t wholedisk = 0;
+			uint64_t part = ZPOOL_PARTITION_LEGACY;
+			boolean_t append;
 
+			if (zhp)
+				part = zpool_get_prop_int(zhp,
+				    ZPOOL_PROP_PARTITION, NULL);
 			(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK,
 			    &wholedisk);
-			if (zfs_strcmp_pathname(srchval, val, wholedisk) == 0)
+
+			append = wholedisk && (part == ZPOOL_PARTITION_LEGACY);
+			if (zfs_strcmp_pathname(srchval, val, append) == 0)
 				return (nv);
 
 		} else if (strcmp(srchkey, ZPOOL_CONFIG_TYPE) == 0 && val) {
@@ -2071,7 +2078,7 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 		return (NULL);
 
 	for (c = 0; c < children; c++) {
-		if ((ret = vdev_to_nvlist_iter(child[c], search,
+		if ((ret = vdev_to_nvlist_iter(zhp, child[c], search,
 		    avail_spare, l2cache, NULL)) != NULL) {
 			/*
 			 * The 'is_log' value is only set for the toplevel
@@ -2092,7 +2099,7 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_SPARES,
 	    &child, &children) == 0) {
 		for (c = 0; c < children; c++) {
-			if ((ret = vdev_to_nvlist_iter(child[c], search,
+			if ((ret = vdev_to_nvlist_iter(zhp, child[c], search,
 			    avail_spare, l2cache, NULL)) != NULL) {
 				*avail_spare = B_TRUE;
 				return (ret);
@@ -2103,7 +2110,7 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_L2CACHE,
 	    &child, &children) == 0) {
 		for (c = 0; c < children; c++) {
-			if ((ret = vdev_to_nvlist_iter(child[c], search,
+			if ((ret = vdev_to_nvlist_iter(zhp, child[c], search,
 			    avail_spare, l2cache, NULL)) != NULL) {
 				*l2cache = B_TRUE;
 				return (ret);
@@ -2134,7 +2141,8 @@ zpool_find_vdev_by_physpath(zpool_handle_t *zhp, const char *ppath,
 	*l2cache = B_FALSE;
 	if (log != NULL)
 		*log = B_FALSE;
-	ret = vdev_to_nvlist_iter(nvroot, search, avail_spare, l2cache, log);
+	ret = vdev_to_nvlist_iter(zhp, nvroot, search, avail_spare, l2cache,
+	    log);
 	nvlist_free(search);
 
 	return (ret);
@@ -2178,7 +2186,8 @@ zpool_find_vdev(zpool_handle_t *zhp, const char *path, boolean_t *avail_spare,
 	*l2cache = B_FALSE;
 	if (log != NULL)
 		*log = B_FALSE;
-	ret = vdev_to_nvlist_iter(nvroot, search, avail_spare, l2cache, log);
+	ret = vdev_to_nvlist_iter(zhp, nvroot, search, avail_spare, l2cache,
+	    log);
 	nvlist_free(search);
 
 	return (ret);

lib/libzfs/libzfs_util.c

@@ -1203,10 +1203,10 @@ zfs_resolve_shortname(const char *name, char *path, size_t len)
  * is done by checking all prefix expansions using either the default
  * 'zpool_default_import_paths' or the ZPOOL_IMPORT_PATH environment
  * variable.  Proper partition suffixes will be appended if this is a
- * whole disk.  When a match is found 0 is returned otherwise ENOENT.
+ * legacy whole disk.  When a match is found 0 is returned otherwise ENOENT.
  */
 static int
-zfs_strcmp_shortname(char *name, char *cmp_name, int wholedisk)
+zfs_strcmp_shortname(char *name, char *cmp_name, int append)
 {
 	int path_len, cmp_len, i = 0, error = ENOENT;
 	char *dir, *env, *envdup = NULL;
@@ -1228,7 +1228,7 @@ zfs_strcmp_shortname(char *name, char *cmp_name, int wholedisk)
 			dir[strlen(dir)-1] = '\0';
 
 		path_len = snprintf(path_name, MAXPATHLEN, "%s/%s", dir, name);
-		if (wholedisk)
+		if (append)
 			path_len = zfs_append_partition(path_name, MAXPATHLEN);
 
 		if ((path_len == cmp_len) && strcmp(path_name, cmp_name) == 0) {
@@ -1257,7 +1257,7 @@ zfs_strcmp_shortname(char *name, char *cmp_name, int wholedisk)
  * purposes and redundant slashes stripped to ensure an accurate match.
  */
 int
-zfs_strcmp_pathname(char *name, char *cmp, int wholedisk)
+zfs_strcmp_pathname(char *name, char *cmp, int append)
 {
 	int path_len, cmp_len;
 	char path_name[MAXPATHLEN];
@@ -1276,13 +1276,13 @@ zfs_strcmp_pathname(char *name, char *cmp, int wholedisk)
 	free(dup);
 
 	if (name[0] != '/')
-		return (zfs_strcmp_shortname(name, cmp_name, wholedisk));
+		return (zfs_strcmp_shortname(name, cmp_name, append));
 
 	(void) strlcpy(path_name, name, MAXPATHLEN);
 	path_len = strlen(path_name);
 	cmp_len = strlen(cmp_name);
 
-	if (wholedisk) {
+	if (append) {
 		path_len = zfs_append_partition(path_name, MAXPATHLEN);
 		if (path_len == -1)
 			return (ENOMEM);

module/zcommon/zpool_prop.c

@@ -64,6 +64,12 @@ zpool_prop_init(void)
 		{ NULL }
 	};
 
+	static zprop_index_t part_table[] = {
+		{ "legacy",	ZPOOL_PARTITION_LEGACY },
+		{ "raw",	ZPOOL_PARTITION_RAW },
+		{ NULL }
+	};
+
 	/* string properties */
 	zprop_register_string(ZPOOL_PROP_ALTROOT, "altroot", NULL, PROP_DEFAULT,
 	    ZFS_TYPE_POOL, "<path>", "ALTROOT");
@@ -125,6 +131,10 @@ zpool_prop_init(void)
 	zprop_register_index(ZPOOL_PROP_FAILUREMODE, "failmode",
 	    ZIO_FAILURE_MODE_WAIT, PROP_DEFAULT, ZFS_TYPE_POOL,
 	    "wait | continue | panic", "FAILMODE", failuremode_table);
+	zprop_register_index(ZPOOL_PROP_PARTITION, "partition",
+	    ZPOOL_PARTITION_LEGACY, PROP_ONETIME, ZFS_TYPE_POOL,
+	    "legacy | raw", "PART", part_table);
+
 
 	/* hidden properties */
 	zprop_register_hidden(ZPOOL_PROP_NAME, "name", PROP_TYPE_STRING,