zfs/cmd/zpool/zpool_iter.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */



#include <libintl.h>
#include <libuutil.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>

#include <libzfs.h>
#include <sys/zfs_context.h>

#include "zpool_util.h"

/*
 * Private interface for iterating over pools specified on the command line.
 * Most consumers will call for_each_pool, but in order to support iostat, we
 * allow fined grained control through the zpool_list_t interface.
 */

typedef struct zpool_node {
	zpool_handle_t	*zn_handle;
	uu_avl_node_t	zn_avlnode;
	int		zn_mark;
} zpool_node_t;

struct zpool_list {
	boolean_t	zl_findall;
	uu_avl_t	*zl_avl;
	uu_avl_pool_t	*zl_pool;
	zprop_list_t	**zl_proplist;
};

/* ARGSUSED */
static int
zpool_compare(const void *larg, const void *rarg, void *unused)
{
	zpool_handle_t *l = ((zpool_node_t *)larg)->zn_handle;
	zpool_handle_t *r = ((zpool_node_t *)rarg)->zn_handle;
	const char *lname = zpool_get_name(l);
	const char *rname = zpool_get_name(r);

	return (strcmp(lname, rname));
}

/*
 * Callback function for pool_list_get().  Adds the given pool to the AVL tree
 * of known pools.
 */
static int
add_pool(zpool_handle_t *zhp, void *data)
{
	zpool_list_t *zlp = data;
	zpool_node_t *node = safe_malloc(sizeof (zpool_node_t));
	uu_avl_index_t idx;

	node->zn_handle = zhp;
	uu_avl_node_init(node, &node->zn_avlnode, zlp->zl_pool);
	if (uu_avl_find(zlp->zl_avl, node, NULL, &idx) == NULL) {
		if (zlp->zl_proplist &&
		    zpool_expand_proplist(zhp, zlp->zl_proplist) != 0) {
			zpool_close(zhp);
			free(node);
			return (-1);
		}
		uu_avl_insert(zlp->zl_avl, node, idx);
	} else {
		zpool_close(zhp);
		free(node);
		return (-1);
	}

	return (0);
}

/*
 * Create a list of pools based on the given arguments.  If we're given no
 * arguments, then iterate over all pools in the system and add them to the AVL
 * tree.  Otherwise, add only those pool explicitly specified on the command
 * line.
 */
zpool_list_t *
pool_list_get(int argc, char **argv, zprop_list_t **proplist, int *err)
{
	zpool_list_t *zlp;

	zlp = safe_malloc(sizeof (zpool_list_t));

	zlp->zl_pool = uu_avl_pool_create("zfs_pool", sizeof (zpool_node_t),
	    offsetof(zpool_node_t, zn_avlnode), zpool_compare, UU_DEFAULT);

	if (zlp->zl_pool == NULL)
		zpool_no_memory();

	if ((zlp->zl_avl = uu_avl_create(zlp->zl_pool, NULL,
	    UU_DEFAULT)) == NULL)
		zpool_no_memory();

	zlp->zl_proplist = proplist;

	if (argc == 0) {
		(void) zpool_iter(g_zfs, add_pool, zlp);
		zlp->zl_findall = B_TRUE;
	} else {
		int i;

		for (i = 0; i < argc; i++) {
			zpool_handle_t *zhp;

			if ((zhp = zpool_open_canfail(g_zfs, argv[i]))) {
				if (add_pool(zhp, zlp) != 0)
					*err = B_TRUE;
			} else {
				*err = B_TRUE;
			}
		}
	}

	return (zlp);
}

/*
 * Search for any new pools, adding them to the list.  We only add pools when no
 * options were given on the command line.  Otherwise, we keep the list fixed as
 * those that were explicitly specified.
 */
void
pool_list_update(zpool_list_t *zlp)
{
	if (zlp->zl_findall)
		(void) zpool_iter(g_zfs, add_pool, zlp);
}

/*
 * Iterate over all pools in the list, executing the callback for each
 */
int
pool_list_iter(zpool_list_t *zlp, int unavail, zpool_iter_f func,
    void *data)
{
	zpool_node_t *node, *next_node;
	int ret = 0;

	for (node = uu_avl_first(zlp->zl_avl); node != NULL; node = next_node) {
		next_node = uu_avl_next(zlp->zl_avl, node);
		if (zpool_get_state(node->zn_handle) != POOL_STATE_UNAVAIL ||
		    unavail)
			ret |= func(node->zn_handle, data);
	}

	return (ret);
}

/*
 * Remove the given pool from the list.  When running iostat, we want to remove
 * those pools that no longer exist.
 */
void
pool_list_remove(zpool_list_t *zlp, zpool_handle_t *zhp)
{
	zpool_node_t search, *node;

	search.zn_handle = zhp;
	if ((node = uu_avl_find(zlp->zl_avl, &search, NULL, NULL)) != NULL) {
		uu_avl_remove(zlp->zl_avl, node);
		zpool_close(node->zn_handle);
		free(node);
	}
}

/*
 * Free all the handles associated with this list.
 */
void
pool_list_free(zpool_list_t *zlp)
{
	uu_avl_walk_t *walk;
	zpool_node_t *node;

	if ((walk = uu_avl_walk_start(zlp->zl_avl, UU_WALK_ROBUST)) == NULL) {
		(void) fprintf(stderr,
		    gettext("internal error: out of memory"));
		exit(1);
	}

	while ((node = uu_avl_walk_next(walk)) != NULL) {
		uu_avl_remove(zlp->zl_avl, node);
		zpool_close(node->zn_handle);
		free(node);
	}

	uu_avl_walk_end(walk);
	uu_avl_destroy(zlp->zl_avl);
	uu_avl_pool_destroy(zlp->zl_pool);

	free(zlp);
}

/*
 * Returns the number of elements in the pool list.
 */
int
pool_list_count(zpool_list_t *zlp)
{
	return (uu_avl_numnodes(zlp->zl_avl));
}

/*
 * High level function which iterates over all pools given on the command line,
 * using the pool_list_* interfaces.
 */
int
for_each_pool(int argc, char **argv, boolean_t unavail,
    zprop_list_t **proplist, zpool_iter_f func, void *data)
{
	zpool_list_t *list;
	int ret = 0;

	if ((list = pool_list_get(argc, argv, proplist, &ret)) == NULL)
		return (1);

	if (pool_list_iter(list, unavail, func, data) != 0)
		ret = 1;

	pool_list_free(list);

	return (ret);
}

static int
for_each_vdev_cb(zpool_handle_t *zhp, nvlist_t *nv, pool_vdev_iter_f func,
    void *data)
{
	nvlist_t **child;
	uint_t c, children;
	int ret = 0;
	int i;
	char *type;

	const char *list[] = {
	    ZPOOL_CONFIG_SPARES,
	    ZPOOL_CONFIG_L2CACHE,
	    ZPOOL_CONFIG_CHILDREN
	};

	for (i = 0; i < ARRAY_SIZE(list); i++) {
		if (nvlist_lookup_nvlist_array(nv, list[i], &child,
		    &children) == 0) {
			for (c = 0; c < children; c++) {
				uint64_t ishole = 0;

				(void) nvlist_lookup_uint64(child[c],
				    ZPOOL_CONFIG_IS_HOLE, &ishole);

				if (ishole)
					continue;

				ret |= for_each_vdev_cb(zhp, child[c], func,
				    data);
			}
		}
	}

	if (nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) != 0)
		return (ret);

	/* Don't run our function on root vdevs */
	if (strcmp(type, VDEV_TYPE_ROOT) != 0) {
		ret |= func(zhp, nv, data);
	}

	return (ret);
}

/*
 * This is the equivalent of for_each_pool() for vdevs.  It iterates thorough
 * all vdevs in the pool, ignoring root vdevs and holes, calling func() on
 * each one.
 *
 * @zhp:	Zpool handle
 * @func:	Function to call on each vdev
 * @data:	Custom data to pass to the function
 */
int
for_each_vdev(zpool_handle_t *zhp, pool_vdev_iter_f func, void *data)
{
	nvlist_t *config, *nvroot = NULL;

	if ((config = zpool_get_config(zhp, NULL)) != NULL) {
		verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
		    &nvroot) == 0);
	}
	return (for_each_vdev_cb(zhp, nvroot, func, data));
}

/* Thread function run for each vdev */
static void
vdev_run_cmd_thread(void *cb_cmd_data)
{
	vdev_cmd_data_t *data = cb_cmd_data;
	char *pos = NULL;
	FILE *fp;
	size_t len = 0;
	char cmd[_POSIX_ARG_MAX];

	/* Set our VDEV_PATH and VDEV_UPATH env vars and run command */
	if (snprintf(cmd, sizeof (cmd), "VDEV_PATH=%s && VDEV_UPATH=%s && %s",
	    data->path, data->upath ? data->upath : "\"\"", data->cmd) >=
	    sizeof (cmd)) {
		/* Our string was truncated */
		return;
	}

	fp = popen(cmd, "r");
	if (fp == NULL)
		return;

	data->line = NULL;

	/* Save the first line of output from the command */
	if (getline(&data->line, &len, fp) != -1) {
		/* Success.  Remove newline from the end, if necessary. */
		if ((pos = strchr(data->line, '\n')) != NULL)
		    *pos = '\0';
	} else {
		data->line = NULL;
	}
	pclose(fp);
}

/* For each vdev in the pool run a command */
static int
for_each_vdev_run_cb(zpool_handle_t *zhp, nvlist_t *nv, void *cb_vcdl)
{
	vdev_cmd_data_list_t *vcdl = cb_vcdl;
	vdev_cmd_data_t *data;
	char *path = NULL;
	int i;

	if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) != 0)
		return (1);

	/* Spares show more than once if they're in use, so skip if exists */
	for (i = 0; i < vcdl->count; i++) {
		if ((strcmp(vcdl->data[i].path, path) == 0) &&
		    (strcmp(vcdl->data[i].pool, zpool_get_name(zhp)) == 0)) {
			/* vdev already exists, skip it */
			return (0);
		}
	}

	/*
	 * Resize our array and add in the new element.
	 */
	if (!(vcdl->data = realloc(vcdl->data,
	    sizeof (*vcdl->data) * (vcdl->count + 1))))
		return (ENOMEM);	/* couldn't realloc */

	data = &vcdl->data[vcdl->count];

	data->pool = strdup(zpool_get_name(zhp));
	data->path = strdup(path);
	data->upath = zfs_get_underlying_path(path);
	data->cmd = vcdl->cmd;

	vcdl->count++;

	return (0);
}

/* Get the names and count of the vdevs */
static int
all_pools_for_each_vdev_gather_cb(zpool_handle_t *zhp, void *cb_vcdl)
{
	return (for_each_vdev(zhp, for_each_vdev_run_cb, cb_vcdl));
}

/*
 * Now that vcdl is populated with our complete list of vdevs, spawn
 * off the commands.
 */
static void
all_pools_for_each_vdev_run_vcdl(vdev_cmd_data_list_t *vcdl)
{
	taskq_t *t;
	int i;
	/* 5 * boot_ncpus selfishly chosen since it works best on LLNL's HW */
	int max_threads = 5 * boot_ncpus;

	/*
	 * Under Linux we use a taskq to parallelize running a command
	 * on each vdev.  It is therefore necessary to initialize this
	 * functionality for the duration of the threads.
	 */
	thread_init();

	t = taskq_create("z_pool_cmd", max_threads, defclsyspri, max_threads,
	    INT_MAX, 0);
	if (t == NULL)
		return;

	/* Spawn off the command for each vdev */
	for (i = 0; i < vcdl->count; i++) {
		(void) taskq_dispatch(t, vdev_run_cmd_thread,
		    (void *) &vcdl->data[i], TQ_SLEEP);
	}

	/* Wait for threads to finish */
	taskq_wait(t);
	taskq_destroy(t);
	thread_fini();
}

/*
 * Run command 'cmd' on all vdevs in all pools.  Saves the first line of output
 * from the command in vcdk->data[].line for all vdevs.
 *
 * Returns a vdev_cmd_data_list_t that must be freed with
 * free_vdev_cmd_data_list();
 */
vdev_cmd_data_list_t *
all_pools_for_each_vdev_run(int argc, char **argv, char *cmd)
{
	vdev_cmd_data_list_t *vcdl;
	vcdl = safe_malloc(sizeof (vdev_cmd_data_list_t));
	vcdl->cmd = cmd;

	/* Gather our list of all vdevs in all pools */
	for_each_pool(argc, argv, B_TRUE, NULL,
	    all_pools_for_each_vdev_gather_cb, vcdl);

	/* Run command on all vdevs in all pools */
	all_pools_for_each_vdev_run_vcdl(vcdl);

	return (vcdl);
}

/*
 * Free the vdev_cmd_data_list_t created by all_pools_for_each_vdev_run()
 */
void
free_vdev_cmd_data_list(vdev_cmd_data_list_t *vcdl)
{
	int i;
	for (i = 0; i < vcdl->count; i++) {
		free(vcdl->data[i].path);
		free(vcdl->data[i].pool);
		free(vcdl->data[i].upath);
		free(vcdl->data[i].line);
	}
	free(vcdl->data);
	free(vcdl);
}