Add zfs_prepare_disk script for disk firmware install

Have libzfs call a special `zfs_prepare_disk` script before a disk is
included into the pool.  The user can edit this script to add things
like a disk firmware update or a disk health check.  Use of the script
is totally optional. See the zfs_prepare_disk manpage for full details.

Signed-off-by: Tony Hutter <hutter2@llnl.gov>

cmd/zed/agents/zfs_mod.c

@@ -377,6 +377,15 @@ zfs_process_add(zpool_handle_t *zhp, nvlist_t *vdev, boolean_t labeled)
 
 	if (is_mpath_wholedisk) {
 		/* Don't label device mapper or multipath disks. */
+		zed_log_msg(LOG_INFO,
+		    "  it's a multipath wholedisk, don't label");
+		if (zpool_prepare_disk(zhp, vdev, "autoreplace") != 0) {
+			zed_log_msg(LOG_INFO,
+			    "  zpool_prepare_disk: could not "
+			    "prepare '%s' (%s)", fullpath,
+			    libzfs_error_description(g_zfshdl));
+			return;
+		}
 	} else if (!labeled) {
 		/*
 		 * we're auto-replacing a raw disk, so label it first
@@ -399,8 +408,10 @@ zfs_process_add(zpool_handle_t *zhp, nvlist_t *vdev, boolean_t labeled)
 		 * If this is a request to label a whole disk, then attempt to
 		 * write out the label.
 		 */
-		if (zpool_label_disk(g_zfshdl, zhp, leafname) != 0) {
-			zed_log_msg(LOG_INFO, "  zpool_label_disk: could not "
+		if (zpool_prepare_and_label_disk(g_zfshdl, zhp, leafname,
+		    vdev, "autoreplace") != 0) {
+			zed_log_msg(LOG_INFO,
+			    "  zpool_prepare_and_label_disk: could not "
 			    "label '%s' (%s)", leafname,
 			    libzfs_error_description(g_zfshdl));
 

cmd/zpool/zpool_iter.c

@@ -440,38 +440,22 @@ vdev_run_cmd(vdev_cmd_data_t *data, char *cmd)
 {
 	int rc;
 	char *argv[2] = {cmd, 0};
-	char *env[5] = {"PATH=/bin:/sbin:/usr/bin:/usr/sbin", NULL, NULL, NULL,
-	    NULL};
+	char **env;
 	char **lines = NULL;
 	int lines_cnt = 0;
 	int i;
 
-	/* Setup our custom environment variables */
-	rc = asprintf(&env[1], "VDEV_PATH=%s",
-	    data->path ? data->path : "");
-	if (rc == -1) {
-		env[1] = NULL;
+	env = zpool_vdev_script_alloc_env(data->pool, data->path, data->upath,
+	    data->vdev_enc_sysfs_path, NULL, NULL);
+	if (env == NULL)
 		goto out;
-	}
-
-	rc = asprintf(&env[2], "VDEV_UPATH=%s",
-	    data->upath ? data->upath : "");
-	if (rc == -1) {
-		env[2] = NULL;
-		goto out;
-	}
-
-	rc = asprintf(&env[3], "VDEV_ENC_SYSFS_PATH=%s",
-	    data->vdev_enc_sysfs_path ?
-	    data->vdev_enc_sysfs_path : "");
-	if (rc == -1) {
-		env[3] = NULL;
-		goto out;
-	}
 
 	/* Run the command */
 	rc = libzfs_run_process_get_stdout_nopath(cmd, argv, env, &lines,
 	    &lines_cnt);
+
+	zpool_vdev_script_free_env(env);
+
 	if (rc != 0)
 		goto out;
 
@@ -483,10 +467,6 @@ vdev_run_cmd(vdev_cmd_data_t *data, char *cmd)
 out:
 	if (lines != NULL)
 		libzfs_free_str_array(lines, lines_cnt);
-
-	/* Start with i = 1 since env[0] was statically allocated */
-	for (i = 1; i < ARRAY_SIZE(env); i++)
-		free(env[i]);
 }
 
 /*

cmd/zpool/zpool_util.h

@@ -124,6 +124,10 @@ vdev_cmd_data_list_t *all_pools_for_each_vdev_run(int argc, char **argv,
 
 void free_vdev_cmd_data_list(vdev_cmd_data_list_t *vcdl);
 
+void free_vdev_cmd_data(vdev_cmd_data_t *data);
+
+int vdev_run_cmd_simple(char *path, char *cmd);
+
 int check_device(const char *path, boolean_t force,
     boolean_t isspare, boolean_t iswholedisk);
 boolean_t check_sector_size_database(char *path, int *sector_size);

cmd/zpool/zpool_vdev.c

@@ -932,7 +932,7 @@ 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 *nv, boolean_t replacing)
 {
 	nvlist_t **child;
 	uint_t c, children;
@@ -1028,8 +1028,13 @@ make_disks(zpool_handle_t *zhp, nvlist_t *nv)
 			/*
 			 * When labeling a pool the raw device node name
 			 * is provided as it appears under /dev/.
+			 *
+			 * Note that 'zhp' will be NULL when we're creating a
+			 * pool.
 			 */
-			if (zpool_label_disk(g_zfs, zhp, devnode) == -1)
+			if (zpool_prepare_and_label_disk(g_zfs, zhp, devnode,
+			    nv, zhp == NULL ? "create" :
+			    replacing ? "replace" : "add") == -1)
 				return (-1);
 
 			/*
@@ -1067,19 +1072,19 @@ 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, child[c], replacing)) != 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, child[c], replacing)) != 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, child[c], replacing)) != 0)
 				return (ret);
 
 	return (0);
@@ -1740,7 +1745,7 @@ 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, newroot, B_FALSE) != 0) {
 			nvlist_free(newroot);
 			return (NULL);
 		}
@@ -1861,7 +1866,7 @@ 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, newroot, replacing) != 0) {
 		nvlist_free(newroot);
 		return (NULL);
 	}

include/libzfs.h

@@ -318,6 +318,14 @@ extern nvlist_t *zpool_find_vdev(zpool_handle_t *, const char *, boolean_t *,
 extern nvlist_t *zpool_find_vdev_by_physpath(zpool_handle_t *, const char *,
     boolean_t *, boolean_t *, boolean_t *);
 extern int zpool_label_disk(libzfs_handle_t *, zpool_handle_t *, const char *);
+extern int zpool_prepare_disk(zpool_handle_t *zhp, nvlist_t *vdev_nv,
+    const char *prepare_str);
+extern int zpool_prepare_and_label_disk(libzfs_handle_t *hdl,
+    zpool_handle_t *, const char *, nvlist_t *vdev_nv, const char *prepare_str);
+extern char ** zpool_vdev_script_alloc_env(const char *pool_name,
+    const char *vdev_path, const char *vdev_upath,
+    const char *vdev_enc_sysfs_path, const char *opt_key, const char *opt_val);
+extern void zpool_vdev_script_free_env(char **env);
 extern uint64_t zpool_vdev_path_to_guid(zpool_handle_t *zhp, const char *path);
 
 const char *zpool_get_state_str(zpool_handle_t *);

lib/libzfs/libzfs.abi

@@ -333,6 +333,8 @@
     <elf-symbol name='zpool_open_canfail' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_open_silent' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_pool_state_to_name' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zpool_prepare_and_label_disk' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zpool_prepare_disk' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_print_unsup_feat' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_prop_align_right' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_prop_column_name' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -380,6 +382,8 @@
     <elf-symbol name='zpool_vdev_remove' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_vdev_remove_cancel' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_vdev_remove_wanted' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zpool_vdev_script_alloc_env' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zpool_vdev_script_free_env' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_vdev_split' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_wait' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_wait_status' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>

lib/libzfs/os/linux/libzfs_pool_os.c

@@ -340,3 +340,193 @@ zpool_label_disk(libzfs_handle_t *hdl, zpool_handle_t *zhp, const char *name)
 	}
 	return (0);
 }
+
+/* PATH + 5 env vars + a NULL entry = 7 */
+#define	ZPOOL_VDEV_SCRIPT_ENV_COUNT 7
+
+/*
+ * There's a few places where ZFS will call external scripts (like the script
+ * in zpool.d/ and `zfs_prepare_disk`).  These scripts are called from a
+ * with a reduced $PATH, and some vdev specific environment vars set.  This
+ * function will allocate an populate the environment variable array that
+ * is passed to these scripts.  The user must free the arrays with
+ * zpool_vdev_script_boilerplate_free() when they are done.
+ *
+ * The following env vars will be set (but value could be blank):
+ *
+ * POOL_NAME
+ * VDEV_PATH
+ * VDEV_UPATH
+ * VDEV_ENC_SYSFS_PATH
+ *
+ * In addition, you can set an optional environment variable named 'opt_key'
+ * to 'opt_val' if you want.
+ *
+ * Returns allocated env[] array on success, NULL otherwise.
+ */
+char **
+zpool_vdev_script_alloc_env(const char *pool_name,
+    const char *vdev_path, const char *vdev_upath,
+    const char *vdev_enc_sysfs_path, const char *opt_key, const char *opt_val)
+{
+	char **env = NULL;
+	int rc;
+
+	env = calloc(ZPOOL_VDEV_SCRIPT_ENV_COUNT, sizeof (*env));
+	if (!env)
+		return (NULL);
+
+	env[0] = strdup("PATH=/bin:/sbin:/usr/bin:/usr/sbin");
+	if (!env[0])
+		goto error;
+
+	/* Setup our custom environment variables */
+	rc = asprintf(&env[1], "POOL_NAME=%s", pool_name ? pool_name : "");
+	if (rc == -1) {
+		env[1] = NULL;
+		goto error;
+	}
+
+	rc = asprintf(&env[2], "VDEV_PATH=%s", vdev_path ? vdev_path : "");
+	if (rc == -1) {
+		env[2] = NULL;
+		goto error;
+	}
+
+	rc = asprintf(&env[3], "VDEV_UPATH=%s", vdev_upath ? vdev_upath : "");
+	if (rc == -1) {
+		env[3] = NULL;
+		goto error;
+	}
+
+	rc = asprintf(&env[4], "VDEV_ENC_SYSFS_PATH=%s",
+	    vdev_enc_sysfs_path ?  vdev_enc_sysfs_path : "");
+	if (rc == -1) {
+		env[4] = NULL;
+		goto error;
+	}
+
+	if (opt_key != NULL) {
+		rc = asprintf(&env[5], "%s=%s", opt_key,
+		    opt_val ? opt_val : "");
+		if (rc == -1) {
+			env[5] = NULL;
+			goto error;
+		}
+	}
+
+	return (env);
+
+error:
+	for (int i = 0; i < ZPOOL_VDEV_SCRIPT_ENV_COUNT; i++)
+		free(env[i]);
+
+	free(env);
+
+	return (NULL);
+}
+
+/*
+ * Free the env[] array that was allocated by zpool_vdev_script_alloc_env().
+ */
+void
+zpool_vdev_script_free_env(char **env)
+{
+	for (int i = 0; i < ZPOOL_VDEV_SCRIPT_ENV_COUNT; i++)
+		free(env[i]);
+
+	free(env);
+}
+
+/*
+ * Prepare a disk by (optionally) running a program before labeling the disk.
+ * This can be useful for installing disk firmware or doing some pre-flight
+ * checks on the disk before it becomes part of the pool.  The program run is
+ * located at LIBEXECDIR/zfs/zfs_prepare_disk (defaults to
+ * /usr/local/libexec/zfs/zfs_prepare_disk).
+ *
+ * Return 0 on success, non-zero on failure.
+ */
+int
+zpool_prepare_disk(zpool_handle_t *zhp, nvlist_t *vdev_nv,
+    const char *prepare_str)
+{
+	const char *script_path = LIBEXECDIR "/zfs_prepare_disk";
+	const char *pool_name;
+	int rc = 0;
+
+	/* Path to script and a NULL entry */
+	char *argv[2] = {(char *)script_path};
+	char **env = NULL;
+	const char *path = NULL, *enc_sysfs_path = NULL;
+	char *upath;
+
+	if (access(script_path, X_OK) != 0) {
+		/* No script, nothing to do */
+		return (0);
+	}
+
+	(void) nvlist_lookup_string(vdev_nv, ZPOOL_CONFIG_PATH, &path);
+	(void) nvlist_lookup_string(vdev_nv, ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH,
+	    &enc_sysfs_path);
+
+	upath = zfs_get_underlying_path(path);
+	pool_name = zhp ? zpool_get_name(zhp) : NULL;
+
+	env = zpool_vdev_script_alloc_env(pool_name, path, upath,
+	    enc_sysfs_path, "VDEV_PREPARE", prepare_str);
+
+	if (env == NULL) {
+		free(upath);
+		return (ENOMEM);
+	}
+
+	rc = libzfs_run_process_get_stdout(script_path, argv, env, NULL, 0);
+	free(upath);
+
+	zpool_vdev_script_free_env(env);
+
+	return (rc);
+}
+
+/*
+ * Optionally run a script and then label a disk.  The script can be used to
+ * prepare a disk for inclusion into the pool.  For example, it might update
+ * the disk's firmware or check it's health.
+ *
+ * The 'name' provided is the short name, stripped of any leading
+ * /dev path, and is passed to zpool_label_disk. vdev_nv is the nvlist for
+ * the vdev.  prepare_str is a string that gets passed as the VDEV_PREPARE
+ * env variable to the script.
+ *
+ * The following env vars are passed to the script:
+ *
+ * POOL_NAME:		The pool name (blank during zpool create)
+ * VDEV_PREPARE:	Reason why the disk is being prepared for inclusion:
+ *			"create", "add", "replace", or "autoreplace"
+ * VDEV_PATH:		Path to the disk
+ * VDEV_UPATH:		One of the 'underlying paths' to the disk.  This is
+ * 			useful for DM devices.
+ * VDEV_ENC_SYSFS_PATH:	Path to the disk's enclosure sysfs path, if available.
+ *
+ * Note, some of these values can be blank.
+ *
+ * Return 0 on success, non-zero otherwise.
+ */
+int
+zpool_prepare_and_label_disk(libzfs_handle_t *hdl, zpool_handle_t *zhp,
+    const char *name, nvlist_t *vdev_nv, const char *prepare_str)
+{
+	int rc;
+	char vdev_path[MAXPATHLEN];
+	(void) snprintf(vdev_path, sizeof (vdev_path), "%s/%s", DISK_ROOT,
+	    name);
+
+	/* zhp will be NULL when creating a pool */
+	rc = zpool_prepare_disk(zhp, vdev_nv, prepare_str);
+	if (rc != 0)
+		return (rc);
+
+	zpool_label_disk(hdl, zhp, name);
+	return (0);
+}

man/Makefile.am

@@ -64,6 +64,7 @@ dist_man_MANS = \
 	man8/zfs-userspace.8 \
 	man8/zfs-wait.8 \
 	man8/zfs_ids_to_path.8 \
+	man8/zfs_prepare_disk.8 \
 	man8/zgenhostid.8 \
 	man8/zinject.8 \
 	man8/zpool.8 \