16 files changed, 485 insertions, 135 deletions

diff --git a/cmd/zed/agents/zfs_mod.c b/cmd/zed/agents/zfs_mod.c
index 053312e9e..ca18ccf1a 100644
--- a/cmd/zed/agents/zfs_mod.c
+++ b/cmd/zed/agents/zfs_mod.c
@@ -215,9 +215,7 @@ zfs_process_add(zpool_handle_t *zhp, nvlist_t *vdev, boolean_t labeled)
 	if (offline)
 		return;  /* don't intervene if it was taken offline */
 
-#ifdef	HAVE_LIBDEVMAPPER
 	is_dm = zfs_dev_is_dm(path);
-#endif
 	zed_log_msg(LOG_INFO, "zfs_process_add: pool '%s' vdev '%s', phys '%s'"
 	    " wholedisk %d, dm %d (%llu)", zpool_get_name(zhp), path,
 	    physpath ? physpath : "NULL", wholedisk, is_dm,
diff --git a/cmd/zed/zed.d/statechange-led.sh b/cmd/zed/zed.d/statechange-led.sh
index 257e4a8a0..d9f7c89f7 100755
--- a/cmd/zed/zed.d/statechange-led.sh
+++ b/cmd/zed/zed.d/statechange-led.sh
@@ -12,8 +12,6 @@
 # Linux SCSI enclosure services (ses) driver.  The script will do nothing
 # if you have no enclosure, or if your enclosure isn't supported.
 #
-# This script also requires ZFS to be built with libdevmapper support.
-#
 # Exit codes:
 #   0: enclosure led successfully set
 #   1: enclosure leds not not available
diff --git a/cmd/zpool/zpool_iter.c b/cmd/zpool/zpool_iter.c
index 1b64a5a5c..b397c7ec2 100644
--- a/cmd/zpool/zpool_iter.c
+++ b/cmd/zpool/zpool_iter.c
@@ -33,6 +33,7 @@
 #include <strings.h>
 
 #include <libzfs.h>
+#include <sys/zfs_context.h>
 
 #include "zpool_util.h"
 
@@ -316,3 +317,162 @@ for_each_vdev(zpool_handle_t *zhp, pool_vdev_iter_f func, void *data)
 	}
 	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 (vcdl));
+	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);
+}
diff --git a/cmd/zpool/zpool_main.c b/cmd/zpool/zpool_main.c
index b6702f22c..e50acbd2a 100644
--- a/cmd/zpool/zpool_main.c
+++ b/cmd/zpool/zpool_main.c
@@ -1510,8 +1510,23 @@ typedef struct status_cbdata {
 	boolean_t	cb_first;
 	boolean_t	cb_dedup_stats;
 	boolean_t	cb_print_status;
+	vdev_cmd_data_list_t	*vcdl;
 } status_cbdata_t;
 
+/* Print output line for specific vdev in a specific pool */
+static void
+zpool_print_cmd(vdev_cmd_data_list_t *vcdl, const char *pool, char *path)
+{
+	int i;
+	for (i = 0; i < vcdl->count; i++) {
+		if ((strcmp(vcdl->data[i].path, path) == 0) &&
+		    (strcmp(vcdl->data[i].pool, pool) == 0)) {
+			printf("%s", vcdl->data[i].line);
+			break;
+		}
+	}
+}
+
 /*
  * Print out configuration state as requested by status_callback.
  */
@@ -1528,6 +1543,7 @@ print_status_config(zpool_handle_t *zhp, status_cbdata_t *cb, const char *name,
 	uint64_t notpresent;
 	spare_cbdata_t spare_cb;
 	char *state;
+	char *path = NULL;
 
 	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
 	    &child, &children) != 0)
@@ -1560,7 +1576,6 @@ print_status_config(zpool_handle_t *zhp, status_cbdata_t *cb, const char *name,
 
 	if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NOT_PRESENT,
 	    &notpresent) == 0) {
-		char *path;
 		verify(nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) == 0);
 		(void) printf("  was %s", path);
 	} else if (vs->vs_aux != 0) {
@@ -1641,6 +1656,13 @@ print_status_config(zpool_handle_t *zhp, status_cbdata_t *cb, const char *name,
 		    "resilvering" : "repairing");
 	}
 
+	if (cb->vcdl != NULL) {
+		if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) == 0) {
+			printf("  ");
+			zpool_print_cmd(cb->vcdl, zpool_get_name(zhp), path);
+		}
+	}
+
 	(void) printf("\n");
 
 	for (c = 0; c < children; c++) {
@@ -2586,6 +2608,7 @@ typedef struct iostat_cbdata {
 	boolean_t cb_literal;
 	boolean_t cb_scripted;
 	zpool_list_t *cb_list;
+	vdev_cmd_data_list_t *vcdl;
 } iostat_cbdata_t;
 
 /*  iostat labels */
@@ -3393,6 +3416,18 @@ print_vdev_stats(zpool_handle_t *zhp, const char *name, nvlist_t *oldnv,
 		print_iostat_histos(cb, oldnv, newnv, scale, name);
 	}
 
+	if (cb->vcdl != NULL) {
+		char *path;
+		if (nvlist_lookup_string(newnv, ZPOOL_CONFIG_PATH,
+		    &path) == 0) {
+			if (!(cb->cb_flags & IOS_ANYHISTO_M))
+				printf("  ");
+			zpool_print_cmd(cb->vcdl, zpool_get_name(zhp), path);
+			if (cb->cb_flags & IOS_ANYHISTO_M)
+				printf("\n");
+		}
+	}
+
 	if (!(cb->cb_flags & IOS_ANYHISTO_M))
 		printf("\n");
 
@@ -3924,10 +3959,11 @@ fsleep(float sec) {
 
 
 /*
- * zpool iostat [-ghHLpPvy] [[-lq]|[-r|-w]] [-n name] [-T d|u]
+ * zpool iostat [-c CMD] [-ghHLpPvy] [[-lq]|[-r|-w]] [-n name] [-T d|u]
  *		[[ pool ...]|[pool vdev ...]|[vdev ...]]
  *		[interval [count]]
  *
+ *	-c CMD  For each vdev, run command CMD
  *	-g	Display guid for individual vdev name.
  *	-L	Follow links when resolving vdev path name.
  *	-P	Display full path for vdev name.
@@ -3965,6 +4001,7 @@ zpool_do_iostat(int argc, char **argv)
 	boolean_t follow_links = B_FALSE;
 	boolean_t full_name = B_FALSE;
 	iostat_cbdata_t cb = { 0 };
+	char *cmd = NULL;
 
 	/* Used for printing error message */
 	const char flag_to_arg[] = {[IOS_LATENCY] = 'l', [IOS_QUEUES] = 'q',
@@ -3973,8 +4010,11 @@ zpool_do_iostat(int argc, char **argv)
 	uint64_t unsupported_flags;
 
 	/* check options */
-	while ((c = getopt(argc, argv, "gLPT:vyhplqrwH")) != -1) {
+	while ((c = getopt(argc, argv, "c:gLPT:vyhplqrwH")) != -1) {
 		switch (c) {
+		case 'c':
+			cmd = optarg;
+			break;
 		case 'g':
 			guid = B_TRUE;
 			break;
@@ -4167,7 +4207,6 @@ zpool_do_iostat(int argc, char **argv)
 		return (1);
 	}
 
-
 	for (;;) {
 		if ((npools = pool_list_count(list)) == 0)
 			(void) fprintf(stderr, gettext("no pools available\n"));
@@ -4217,8 +4256,15 @@ zpool_do_iostat(int argc, char **argv)
 				continue;
 			}
 
+			if (cmd != NULL)
+				cb.vcdl = all_pools_for_each_vdev_run(argc,
+				    argv, cmd);
+
 			pool_list_iter(list, B_FALSE, print_iostat, &cb);
 
+			if (cb.vcdl != NULL)
+				free_vdev_cmd_data_list(cb.vcdl);
+
 			/*
 			 * If there's more than one pool, and we're not in
 			 * verbose mode (which prints a separator for us),
@@ -6016,8 +6062,9 @@ status_callback(zpool_handle_t *zhp, void *data)
 }
 
 /*
- * zpool status [-gLPvx] [-T d|u] [pool] ... [interval [count]]
+ * zpool status [-c CMD] [-gLPvx] [-T d|u] [pool] ... [interval [count]]
  *
+ *	-c CMD	For each vdev, run command CMD
  *	-g	Display guid for individual vdev name.
  *	-L	Follow links when resolving vdev path name.
  *	-P	Display full path for vdev name.
@@ -6036,10 +6083,14 @@ zpool_do_status(int argc, char **argv)
 	float interval = 0;
 	unsigned long count = 0;
 	status_cbdata_t cb = { 0 };
+	char *cmd = NULL;
 
 	/* check options */
-	while ((c = getopt(argc, argv, "gLPvxDT:")) != -1) {
+	while ((c = getopt(argc, argv, "c:gLPvxDT:")) != -1) {
 		switch (c) {
+		case 'c':
+			cmd = optarg;
+			break;
 		case 'g':
 			cb.cb_name_flags |= VDEV_NAME_GUID;
 			break;
@@ -6083,9 +6134,15 @@ zpool_do_status(int argc, char **argv)
 		if (timestamp_fmt != NODATE)
 			print_timestamp(timestamp_fmt);
 
+		if (cmd != NULL)
+			cb.vcdl = all_pools_for_each_vdev_run(argc, argv, cmd);
+
 		ret = for_each_pool(argc, argv, B_TRUE, NULL,
 		    status_callback, &cb);
 
+		if (cb.vcdl != NULL)
+			free_vdev_cmd_data_list(cb.vcdl);
+
 		if (argc == 0 && cb.cb_count == 0)
 			(void) fprintf(stderr, gettext("no pools available\n"));
 		else if (cb.cb_explain && cb.cb_first && cb.cb_allpools)
diff --git a/cmd/zpool/zpool_util.h b/cmd/zpool/zpool_util.h
index f279fd5dd..811619602 100644
--- a/cmd/zpool/zpool_util.h
+++ b/cmd/zpool/zpool_util.h
@@ -72,6 +72,27 @@ void pool_list_remove(zpool_list_t *, zpool_handle_t *);
 
 libzfs_handle_t *g_zfs;
 
+
+typedef	struct vdev_cmd_data
+{
+	char *line;	/* cmd output */
+	char *path;	/* vdev path */
+	char *upath;	/* vdev underlying path */
+	char *pool;	/* Pool name */
+	char *cmd;	/* backpointer to cmd */
+} vdev_cmd_data_t;
+
+typedef struct vdev_cmd_data_list
+{
+	char *cmd;		/* Command to run */
+	unsigned int count;	/* Number of vdev_cmd_data items (vdevs) */
+	vdev_cmd_data_t *data;	/* Array of vdevs */
+} vdev_cmd_data_list_t;
+
+vdev_cmd_data_list_t * all_pools_for_each_vdev_run(int argc, char **argv,
+    char *cmd);
+void free_vdev_cmd_data_list(vdev_cmd_data_list_t *vcdl);
+
 #ifdef	__cplusplus
 }
 #endif
diff --git a/config/user-libdevmapper.m4 b/config/user-libdevmapper.m4
deleted file mode 100644
index af4dd41c3..000000000
--- a/config/user-libdevmapper.m4
+++ /dev/null
@@ -1,15 +0,0 @@
-dnl #
-dnl # Check for libdevmapper.  libdevmapper is optional for building, but
-dnl # required for auto-online/auto-replace functionality for DM/multipath
-dnl # disks.
-dnl #
-AC_DEFUN([ZFS_AC_CONFIG_USER_LIBDEVMAPPER], [
-        AC_CHECK_HEADER([libdevmapper.h], [
-            AC_SUBST([LIBDEVMAPPER], ["-ldevmapper"])
-            AC_DEFINE([HAVE_LIBDEVMAPPER], 1, [Define if you have libdevmapper])
-
-	    user_libdevmapper=yes
-        ], [
-	    user_libdevmapper=no
-	])
-])
diff --git a/config/user.m4 b/config/user.m4
index 1d20642b8..f70ab635f 100644
--- a/config/user.m4
+++ b/config/user.m4
@@ -12,7 +12,6 @@ AC_DEFUN([ZFS_AC_CONFIG_USER], [
 	ZFS_AC_CONFIG_USER_LIBTIRPC
 	ZFS_AC_CONFIG_USER_LIBBLKID
 	ZFS_AC_CONFIG_USER_LIBATTR
-	ZFS_AC_CONFIG_USER_LIBDEVMAPPER
 	ZFS_AC_CONFIG_USER_LIBUDEV
 	ZFS_AC_CONFIG_USER_FRAME_LARGER_THAN
 	ZFS_AC_CONFIG_USER_RUNSTATEDIR
diff --git a/configure.ac b/configure.ac
index dffd63cf2..efe61305d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -304,8 +304,3 @@ AC_CONFIG_FILES([
 
 
 AC_OUTPUT
-
-AS_IF([test "x$user_libdevmapper" != xyes && test "$ZFS_CONFIG" != kernel ], [
-    AC_MSG_WARN([Building without libdevmapper.  Auto-replace, auto-online, \
-and statechange-led.sh may not work correctly with device mapper vdevs.])
-])
diff --git a/include/libzfs.h b/include/libzfs.h
index 67f4bf4b4..d74bf6b10 100644
--- a/include/libzfs.h
+++ b/include/libzfs.h
@@ -838,6 +838,7 @@ extern int zpool_fru_set(zpool_handle_t *, uint64_t, const char *);
 extern boolean_t is_mpath_whole_disk(const char *);
 extern void update_vdev_config_dev_strs(nvlist_t *);
 extern char *zfs_strip_partition(char *);
+extern char *zfs_strip_partition_path(char *);
 
 #ifdef HAVE_LIBUDEV
 struct udev_device;
diff --git a/lib/libzfs/Makefile.am b/lib/libzfs/Makefile.am
index 8e596b001..f1260ea71 100644
--- a/lib/libzfs/Makefile.am
+++ b/lib/libzfs/Makefile.am
@@ -35,7 +35,7 @@ libzfs_la_LIBADD = \
 	$(top_builddir)/lib/libnvpair/libnvpair.la \
 	$(top_builddir)/lib/libzpool/libzpool.la
 
-libzfs_la_LIBADD += -lm $(LIBBLKID) $(LIBUDEV) $(LIBDEVMAPPER)
+libzfs_la_LIBADD += -lm $(LIBBLKID) $(LIBUDEV)
 libzfs_la_LDFLAGS = -version-info 2:0:0
 
 EXTRA_DIST = $(libzfs_pc_DATA) $(USER_C)
diff --git a/lib/libzfs/libzfs_pool.c b/lib/libzfs/libzfs_pool.c
index 6727a77e7..9d0702b56 100644
--- a/lib/libzfs/libzfs_pool.c
+++ b/lib/libzfs/libzfs_pool.c
@@ -41,9 +41,6 @@
 #include <sys/vtoc.h>
 #include <sys/zfs_ioctl.h>
 #include <dlfcn.h>
-#if HAVE_LIBDEVMAPPER
-#include <libdevmapper.h>
-#endif
 
 #include "zfs_namecheck.h"
 #include "zfs_prop.h"
@@ -3432,6 +3429,43 @@ zfs_strip_partition(char *path)
 	return (tmp);
 }
 
+/*
+ * Same as zfs_strip_partition, but allows "/dev/" to be in the pathname
+ *
+ * path:	/dev/sda1
+ * returns:	/dev/sda
+ *
+ * Returned string must be freed.
+ */
+char *
+zfs_strip_partition_path(char *path)
+{
+	char *newpath = strdup(path);
+	char *sd_offset;
+	char *new_sd;
+
+	if (!newpath)
+		return (NULL);
+
+	/* Point to "sda1" part of "/dev/sda1" */
+	sd_offset = strrchr(newpath, '/') + 1;
+
+	/* Get our new name "sda" */
+	new_sd = zfs_strip_partition(sd_offset);
+	if (!new_sd) {
+		free(newpath);
+		return (NULL);
+	}
+
+	/* Paste the "sda" where "sda1" was */
+	strlcpy(sd_offset, new_sd, strlen(sd_offset) + 1);
+
+	/* Free temporary "sda" */
+	free(new_sd);
+
+	return (newpath);
+}
+
 #define	PATH_BUF_LEN	64
 
 /*
@@ -4318,112 +4352,69 @@ zpool_label_disk(libzfs_handle_t *hdl, zpool_handle_t *zhp, char *name)
 	return (0);
 }
 
-#if HAVE_LIBDEVMAPPER
-static void libdevmapper_dummy_log(int level, const char *file, int line,
-    int dm_errno_or_class, const char *f, ...) {}
-
-/* Disable libdevmapper error logging */
-static void disable_libdevmapper_errors(void) {
-	dm_log_with_errno_init(libdevmapper_dummy_log);
-}
-/* Enable libdevmapper error logging */
-static void enable_libdevmapper_errors(void) {
-	dm_log_with_errno_init(NULL);
-}
-#endif
-
 /*
  * Allocate and return the underlying device name for a device mapper device.
  * If a device mapper device maps to multiple devices, return the first device.
  *
- * For example, dm_name = "/dev/dm-0" could return "/dev/sda"
- *
- * dm_name should include the "/dev[/mapper]" prefix.
+ * For example, dm_name = "/dev/dm-0" could return "/dev/sda". Symlinks to a
+ * DM device (like /dev/disk/by-vdev/A0) are also allowed.
  *
  * Returns device name, or NULL on error or no match.  If dm_name is not a DM
  * device then return NULL.
  *
  * NOTE: The returned name string must be *freed*.
  */
-static char * dm_get_underlying_path(char *dm_name)
+char *
+dm_get_underlying_path(char *dm_name)
 {
-	char *name = NULL;
-#if HAVE_LIBDEVMAPPER
-	char *tmp;
-	struct dm_task *dmt = NULL;
-	struct dm_tree *dt = NULL;
-	struct dm_tree_node *root, *child;
-	void *handle = NULL;
-	struct dm_info info;
-	const struct dm_info *child_info;
+	DIR *dp = NULL;
+	struct dirent *ep;
+	char *realp;
+	char *tmp = NULL;
+	char *path = NULL;
+	char *dev_str;
+	int size;
 
-	/*
-	 * Disable libdevmapper errors.  It's entirely possible user is not
-	 * running devmapper, or that dm_name is not a devmapper device.
-	 * That's totally ok, we will just harmlessly and silently return NULL.
-	 */
-	disable_libdevmapper_errors();
+	if (dm_name == NULL)
+		return (NULL);
+
+	/* dm name may be a symlink (like /dev/disk/by-vdev/A0) */
+	realp = realpath(dm_name, NULL);
+	if (realp == NULL)
+		return (NULL);
 
 	/*
-	 * libdevmapper tutorial
-	 *
-	 * libdevmapper is basically a fancy wrapper for its ioctls.  You
-	 * create a "task", fill in the needed info to the task (fill in the
-	 * ioctl fields), then run the task (call the ioctl).
-	 *
-	 * First we need the major/minor number for our DM device.
+	 * If they preface 'dev' with a path (like "/dev") then strip it off.
+	 * We just want the 'dm-N' part.
 	 */
-	if (!(dmt = dm_task_create(DM_DEVICE_INFO)))
-		goto end;
-
-	/* Lookup the name in libdevmapper */
-	if (!dm_task_set_name(dmt, dm_name)) {
-		enable_libdevmapper_errors();
-		goto end;
-	}
-
-	if (!dm_task_run(dmt))
-		goto end;
-
-	/* Get DM device's major/minor */
-	if (!dm_task_get_info(dmt, &info))
-		goto end;
-
-	/* We have major/minor number.  Lookup the dm device's children */
-	if (!(dt = dm_tree_create()))
-		goto end;
-
-	/* We add the device into the tree and its children get populated */
-	if (!dm_tree_add_dev(dt, info.major, info.minor))
-		goto end;
-
-	if (!(root = dm_tree_find_node(dt, 0, 0)))
-		goto end;
-
-	if (!(child = dm_tree_next_child(&handle, root, 1)))
-		goto end;
+	tmp = strrchr(realp, '/');
+	if (tmp != NULL)
+		dev_str = tmp + 1;    /* +1 since we want the chr after '/' */
+	else
+		dev_str = tmp;
 
-	/* Get child's major/minor numbers */
-	if (!(child_info = dm_tree_node_get_info(child)))
+	size = asprintf(&tmp, "/sys/block/%s/slaves/", dev_str);
+	if (size == -1 || !tmp)
 		goto end;
 
-	if ((asprintf(&tmp, "/dev/block/%d:%d", child_info->major,
-	    child_info->minor) == -1) || tmp == NULL)
+	dp = opendir(tmp);
+	if (dp == NULL)
 		goto end;
 
-	/* Further translate /dev/block/ name into the normal name */
-	name = realpath(tmp, NULL);
-	free(tmp);
+	/* Return first sd* entry in /sys/block/dm-N/slaves/ */
+	while ((ep = readdir(dp))) {
+		if (ep->d_type != DT_DIR) {	/* skip "." and ".." dirs */
+			size = asprintf(&path, "/dev/%s", ep->d_name);
+			break;
+		}
+	}
 
 end:
-	if (dmt)
-		dm_task_destroy(dmt);
-	if (dt)
-		dm_tree_free(dt);
-	enable_libdevmapper_errors();
-#endif /* HAVE_LIBDEVMAPPER */
-
-	return (name);
+	if (dp != NULL)
+		closedir(dp);
+	free(tmp);
+	free(realp);
+	return (path);
 }
 
 /*
@@ -4436,7 +4427,7 @@ zfs_dev_is_dm(char *dev_name)
 
 	char *tmp;
 	tmp = dm_get_underlying_path(dev_name);
-	if (!tmp)
+	if (tmp == NULL)
 		return (0);
 
 	free(tmp);
@@ -4489,17 +4480,17 @@ zfs_get_underlying_path(char *dev_name)
 	char *name = NULL;
 	char *tmp;
 
-	if (!dev_name)
+	if (dev_name == NULL)
 		return (NULL);
 
 	tmp = dm_get_underlying_path(dev_name);
 
 	/* dev_name not a DM device, so just un-symlinkize it */
-	if (!tmp)
+	if (tmp == NULL)
 		tmp = realpath(dev_name, NULL);
 
-	if (tmp) {
-		name = zfs_strip_partition(tmp);
+	if (tmp != NULL) {
+		name = zfs_strip_partition_path(tmp);
 		free(tmp);
 	}
 
@@ -4532,12 +4523,12 @@ zfs_get_enclosure_sysfs_path(char *dev_name)
 	size_t size;
 	int tmpsize;
 
-	if (!dev_name)
+	if (dev_name == NULL)
 		return (NULL);
 
 	/* If they preface 'dev' with a path (like "/dev") then strip it off */
 	tmp1 = strrchr(dev_name, '/');
-	if (tmp1)
+	if (tmp1 != NULL)
 		dev_name = tmp1 + 1;    /* +1 since we want the chr after '/' */
 
 	tmpsize = asprintf(&tmp1, "/sys/block/%s/device", dev_name);
@@ -4558,7 +4549,7 @@ zfs_get_enclosure_sysfs_path(char *dev_name)
 	 */
 	while ((ep = readdir(dp))) {
 		/* Ignore everything that's not our enclosure_device link */
-		if (!strstr(ep->d_name, "enclosure_device"))
+		if (strstr(ep->d_name, "enclosure_device") == NULL)
 			continue;
 
 		if (asprintf(&tmp2, "%s/%s", tmp1, ep->d_name) == -1 ||
@@ -4605,7 +4596,7 @@ end:
 	free(tmp2);
 	free(tmp1);
 
-	if (dp)
+	if (dp != NULL)
 		closedir(dp);
 
 	return (path);
diff --git a/man/man8/zpool.8 b/man/man8/zpool.8
index 42e5c28d2..883d11739 100644
--- a/man/man8/zpool.8
+++ b/man/man8/zpool.8
@@ -96,7 +96,7 @@ zpool \- configures ZFS storage pools
 
 .LP
 .nf
-\fB\fBzpool iostat\fR [\fB-T\fR \fBd\fR | \fBu\fR] [\fB-ghHLpPvy\fR] [\fB-lq\fR]|[\fB-r\fR|-\fBw\fR]]
+\fB\fBzpool iostat\fR [\fB-c\fR \fBCMD\fR] [\fB-T\fR \fBd\fR | \fBu\fR] [\fB-ghHLpPvy\fR] [\fB-lq\fR]|[\fB-r\fR|-\fBw\fR]]
      [[\fIpool\fR ...]|[\fIpool vdev\fR ...]|[\fIvdev\fR ...]] [\fIinterval\fR[\fIcount\fR]]\fR
 
 .fi
@@ -159,7 +159,7 @@ zpool \- configures ZFS storage pools
 
 .LP
 .nf
-\fBzpool status\fR [\fB-gLPvxD\fR] [\fB-T\fR d | u] [\fIpool\fR] ... [\fIinterval\fR [\fIcount\fR]]
+\fBzpool status\fR [\fB-c\fR \fBCMD\fR] [\fB-gLPvxD\fR] [\fB-T\fR d | u] [\fIpool\fR] ... [\fIinterval\fR [\fIcount\fR]]
 .fi
 
 .LP
@@ -1523,7 +1523,7 @@ Scan using the default search path, the libblkid cache will not be consulted.  A
 .sp
 .ne 2
 .na
-\fB\fBzpool iostat\fR [\fB-T\fR \fBd\fR | \fBu\fR] [\fB-ghHLpPvy\fR] [[\fB-lq\fR]|[\fB-r\fR|\fB-w\fR]] [[\fIpool\fR ...]|[\fIpool vdev\fR ...]|[\fIvdev\fR ...]] [\fIinterval\fR[\fIcount\fR]]\fR
+\fB\fBzpool iostat\fR [\fB-c\fR \fBCMD\fR] [\fB-T\fR \fBd\fR | \fBu\fR] [\fB-ghHLpPvy\fR] [[\fB-lq\fR]|[\fB-r\fR|\fB-w\fR]] [[\fIpool\fR ...]|[\fIpool vdev\fR ...]|[\fIvdev\fR ...]] [\fIinterval\fR[\fIcount\fR]]\fR
 
 .ad
 .sp .6
@@ -1542,6 +1542,23 @@ base 1024.  To get the raw values, use the \fB-p\fR flag.
 .sp
 .ne 2
 .na
+\fB\fB-c\fR \fBCMD\fR
+.ad
+.RS 12n
+Run a command on each vdev and include first line of output
+.sp
+The \fB-c\fR option allows you to run an arbitrary command on each vdev and
+display the first line of output in zpool iostat.  The environment vars
+\fBVDEV_PATH\fR and \fBVDEV_UPATH\fR are set to the vdev's path and "underlying
+path" before running the command.  For device mapper, multipath, or partitioned
+vdevs, \fBVDEV_UPATH\fR is the actual underlying /dev/sd* disk.  This can be
+useful if the command you're running requires a /dev/sd* device.  Commands run
+in parallel for each vdev for performance.
+.RE
+
+.sp
+.ne 2
+.na
 \fB\fB-T\fR \fBu\fR | \fBd\fR\fR
 .ad
 .RS 12n
@@ -2082,7 +2099,7 @@ Sets the specified property for \fInewpool\fR. See the “Properties” section
 .sp
 .ne 2
 .na
-\fBzpool status\fR [\fB-gLPvxD\fR] [\fB-T\fR d | u] [\fIpool\fR] ... [\fIinterval\fR [\fIcount\fR]]
+\fBzpool status\fR [\fB-c\fR \fBCMD\fR] [\fB-gLPvxD\fR] [\fB-T\fR d | u] [\fIpool\fR] ... [\fIinterval\fR [\fIcount\fR]]
 .ad
 .sp .6
 .RS 4n
@@ -2093,6 +2110,23 @@ If a scrub or resilver is in progress, this command reports the percentage done
 .sp
 .ne 2
 .na
+\fB\fB-c\fR \fBCMD\fR
+.ad
+.RS 12n
+Run a command on each vdev and include first line of output
+.sp
+The \fB-c\fR option allows you to run an arbitrary command on each vdev and
+display the first line of output in zpool status.  The environment vars
+\fBVDEV_PATH\fR and \fBVDEV_UPATH\fR are set to the vdev's path and "underlying
+path" before running the command.  For device mapper, multipath, or partitioned
+vdevs, \fBVDEV_UPATH\fR is the actual underlying /dev/sd* disk.  This can be
+useful if the command you're running requires a /dev/sd* device.  Commands run
+in parallel for each vdev for performance.
+.RE
+
+.sp
+.ne 2
+.na
 \fB\fB-g\fR\fR
 .ad
 .RS 12n
@@ -2519,6 +2553,40 @@ data        23.9G  14.6G  9.30G    48%         -    61%  1.00x  ONLINE  -
     c1t3d0      -      -      -      -         -
 .fi
 .in -2
+.sp
+
+.LP
+\fBExample 16 \fRRunning commands in zpool status and zpool iostat with -c
+.sp
+.LP
+Some examples of using the command (-c) option with zpool status and zpool
+iostat:
+.sp
+.in +2
+.nf
+# \fBzpool status -c  \[aq]echo I am $VDEV_PATH, $VDEV_UPATH\[aq]\fR
+NAME        STATE     READ WRITE CKSUM
+mypool      ONLINE       0     0     0
+  mirror-0  ONLINE       0     0     0
+    mpatha  ONLINE       0     0     0  I am /dev/mapper/mpatha, /dev/sdc
+    sdb     ONLINE       0     0     0  I am /dev/sdb1, /dev/sdb
+.fi
+.in -2
+
+.sp
+.in +2
+.nf
+# \fBzpool iostat -v -c \[aq]smartctl -a $VDEV_UPATH | grep "Current Drive Temperature"\[aq]\fR
+mypool       997M  7.25T      0      0   105K   106K
+  mirror     997M  7.25T      0      0   105K   106K
+    B0          -      -      0      0  17.4K  15.2K  Current Drive Temperature:     25 C
+    B1          -      -      0      0  17.4K  15.2K  Current Drive Temperature:     24 C
+    B2          -      -      0      0  17.5K  15.2K  Current Drive Temperature:     24 C
+    B3          -      -      0      0      0  15.1K  Current Drive Temperature:     24 C
+logs            -      -      -      -      -      -
+  B8            0  7.25T      0      0  1.14K  20.2K  Current Drive Temperature:     23 C
+.fi
+.in -2
 
 .SH EXIT STATUS
 .sp
diff --git a/rpm/generic/zfs.spec.in b/rpm/generic/zfs.spec.in
index 6703c768b..c211166c9 100644
--- a/rpm/generic/zfs.spec.in
+++ b/rpm/generic/zfs.spec.in
@@ -74,7 +74,6 @@ Requires:       libzpool2 = %{version}
 Requires:       libnvpair1 = %{version}
 Requires:       libuutil1 = %{version}
 Requires:       libzfs2 = %{version}
-Requires:       device-mapper
 Requires:       %{name}-kmod = %{version}
 Provides:       %{name}-kmod-common = %{version}
 
@@ -86,7 +85,6 @@ Conflicts:      zfs-fuse
 BuildRequires:  zlib-devel
 BuildRequires:  libuuid-devel
 BuildRequires:  libblkid-devel
-BuildRequires:  device-mapper-devel
 BuildRequires:  libudev-devel
 BuildRequires:  libattr-devel
 %endif
diff --git a/tests/zfs-tests/tests/functional/cli_user/misc/zpool_status_001_neg.ksh b/tests/zfs-tests/tests/functional/cli_user/misc/zpool_status_001_neg.ksh
index 42111a6a1..4c6f11c0a 100755
--- a/tests/zfs-tests/tests/functional/cli_user/misc/zpool_status_001_neg.ksh
+++ b/tests/zfs-tests/tests/functional/cli_user/misc/zpool_status_001_neg.ksh
@@ -69,6 +69,21 @@ check_pool_status
 log_must eval "$ZPOOL status -v $TESTPOOL > /tmp/pool-status.$$"
 check_pool_status
 
+# Make sure -c option works, and that VDEV_PATH and VDEV_UPATH get set.
+#
+# grep for '^\s+/' to just get the vdevs (not pools).  All vdevs will start with
+# a '/' when we specify the path (-P) flag. We check for "{}" to see if one
+# of the VDEV variables isn't set.
+C1=$($ZPOOL status -P | $GREP -E '^\s+/' | $WC -l)
+C2=$($ZPOOL status -P -c 'echo vdev_test{$VDEV_PATH}{$VDEV_UPATH}' | \
+    $GREP -E '^\s+/' | $GREP -v '{}' | $WC -l)
+
+if [ "$C1" != "$C2" ] ; then
+	log_fail "zpool status -c option failed.  Expected $C1 vdevs, got $C2"
+else
+	log_pass "zpool status -c option passed.  Expected $C1 vdevs, got $C2"
+fi
+
 # $TESTPOOL.virt has an offline device, so -x will show it
 log_must eval "$ZPOOL status -x $TESTPOOL.virt > /tmp/pool-status.$$"
 check_pool_status
diff --git a/tests/zfs-tests/tests/functional/cli_user/zpool_iostat/Makefile.am b/tests/zfs-tests/tests/functional/cli_user/zpool_iostat/Makefile.am
index 621dff91f..cadf9439a 100644
--- a/tests/zfs-tests/tests/functional/cli_user/zpool_iostat/Makefile.am
+++ b/tests/zfs-tests/tests/functional/cli_user/zpool_iostat/Makefile.am
@@ -5,4 +5,5 @@ dist_pkgdata_SCRIPTS = \
 	zpool_iostat_001_neg.ksh \
 	zpool_iostat_002_pos.ksh \
 	zpool_iostat_003_neg.ksh \
-	zpool_iostat_004_pos.ksh
+	zpool_iostat_004_pos.ksh \
+	zpool_iostat_005_pos.ksh
diff --git a/tests/zfs-tests/tests/functional/cli_user/zpool_iostat/zpool_iostat_005_pos.ksh b/tests/zfs-tests/tests/functional/cli_user/zpool_iostat/zpool_iostat_005_pos.ksh
new file mode 100755
index 000000000..be38933c1
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/cli_user/zpool_iostat/zpool_iostat_005_pos.ksh
@@ -0,0 +1,63 @@
+#!/bin/ksh -p
+#
+# 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.
+#
+
+#
+# Copyright (c) 2013 by Delphix. All rights reserved.
+#
+
+#
+# Copyright (c) 2016 by Lawrence Livermore National Security, LLC.
+#
+
+
+. $STF_SUITE/include/libtest.shlib
+
+verify_runnable "both"
+
+typeset testpool
+if is_global_zone ; then
+	testpool=$TESTPOOL
+else
+	testpool=${TESTPOOL%%/*}
+fi
+
+#
+# DESCRIPTION:
+# Verify 'zpool iostat -c CMD' works, and that VDEV_PATH and VDEV_UPATH get set.
+#
+# STRATEGY:
+# grep for '^\s+/' to just get the vdevs (not pools).  All vdevs will start with
+# a '/' when we specify the path (-P) flag. We check for "{}" to see if one
+# of the VDEV variables isn't set.
+#
+C1=$($ZPOOL iostat -Pv | $GREP -E '^\s+/' | $WC -l)
+C2=$($ZPOOL iostat -Pv -c 'echo vdev_test{$VDEV_PATH}{$VDEV_UPATH}' | $GREP -E '^\s+/' | $GREP -v '{}' | $WC -l)
+if [ "$C1" != "$C2" ] ; then
+	log_fail "zpool iostat -c failed, expected $C1 vdevs, got $C2"
+else
+	log_pass "zpool iostat -c passed, expected $C1 vdevs, got $C2"
+fi