[WIP] Prototype for systemd and fstab integration

cmd/Makefile.am

@@ -1,3 +1,3 @@
 SUBDIRS  = zfs zpool zdb zhack zinject zstreamdump ztest zpios
 SUBDIRS += mount_zfs fsck_zfs zvol_id vdev_id arcstat dbufstat zed
-SUBDIRS += arc_summary raidz_test
+SUBDIRS += arc_summary raidz_test zready

cmd/zpool/zpool_main.c

@@ -2191,6 +2191,7 @@ zpool_do_import(int argc, char **argv)
 	boolean_t do_rewind = B_FALSE;
 	boolean_t xtreme_rewind = B_FALSE;
 	boolean_t do_scan = B_FALSE;
+	boolean_t do_imported = B_FALSE;
 	uint64_t pool_state, txg = -1ULL;
 	char *cachefile = NULL;
 	importargs_t idata = { 0 };
@@ -2221,6 +2222,9 @@ zpool_do_import(int argc, char **argv)
 		case 'D':
 			do_destroyed = B_TRUE;
 			break;
+		case 'E':
+			do_imported = B_TRUE;
+			break;
 		case 'f':
 			flags |= ZFS_IMPORT_ANY_HOST;
 			break;
@@ -2420,6 +2424,11 @@ zpool_do_import(int argc, char **argv)
 
 	if (pools != NULL && idata.exists &&
 	    (argc == 1 || strcmp(argv[0], argv[1]) == 0)) {
+		if (do_imported) {
+			err = 0;
+			log_history = B_FALSE;
+			goto exit_early;
+		}
 		(void) fprintf(stderr, gettext("cannot import '%s': "
 		    "a pool with that name already exists\n"),
 		    argv[0]);
@@ -2443,12 +2452,13 @@ zpool_do_import(int argc, char **argv)
 	}
 
 	if (err == 1) {
+exit_early:
 		if (searchdirs != NULL)
 			free(searchdirs);
 		if (envdup != NULL)
 			free(envdup);
 		nvlist_free(policy);
-		return (1);
+		return (err);
 	}
 
 	/*

cmd/zready/.gitignore

@@ -0,0 +1 @@
+/zready

cmd/zready/Makefile.am

@@ -0,0 +1,19 @@
+include $(top_srcdir)/config/Rules.am
+
+AM_CPPFLAGS += -DDEBUG
+
+DEFAULT_INCLUDES += \
+	-I$(top_srcdir)/include \
+	-I$(top_srcdir)/lib/libspl/include
+
+sbin_PROGRAMS = zready
+
+zready_SOURCES = \
+	zready.c
+
+zready_LDADD = \
+	$(top_builddir)/lib/libnvpair/libnvpair.la \
+	$(top_builddir)/lib/libuutil/libuutil.la \
+	$(top_builddir)/lib/libzpool/libzpool.la \
+	$(top_builddir)/lib/libzfs/libzfs.la \
+	$(top_builddir)/lib/libzfs_core/libzfs_core.la

cmd/zready/zready.c

@@ -0,0 +1,272 @@
+/*
+ * 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
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <sys/zfs_context.h>
+#include <sys/vdev.h>
+#include <sys/vdev_impl.h>
+#include <sys/stat.h>
+
+#define ZPOOL_PATH "/dev/zpool"
+
+static nvlist_t *
+get_config(const char *dev)
+{
+	int fd;
+	vdev_label_t label;
+	char *path, *buf = label.vl_vdev_phys.vp_nvlist;
+	size_t buflen = sizeof (label.vl_vdev_phys.vp_nvlist);
+	struct stat64 statbuf;
+	uint64_t psize;
+	int l;
+	int found = 0;
+	nvlist_t *best = NULL;
+	uint64_t best_txg = 0;
+	uint64_t state;
+	uint64_t pguid = 0;
+
+	path = strdup(dev);
+
+	if ((fd = open64(path, O_RDONLY)) < 0) {
+		(void) printf("cannot open '%s': %s\n", path, strerror(errno));
+		free(path);
+		exit(1);
+	}
+
+	if (fstat64_blk(fd, &statbuf) != 0) {
+		(void) printf("failed to stat '%s': %s\n", path,
+		    strerror(errno));
+		free(path);
+		(void) close(fd);
+		exit(1);
+	}
+
+	psize = statbuf.st_size;
+	psize = P2ALIGN(psize, (uint64_t)sizeof (vdev_label_t));
+
+	for (l = 0; l < VDEV_LABELS; l++) {
+		uint64_t g, txg;
+		nvlist_t *config = NULL;
+
+		if (pread64(fd, &label, sizeof (label),
+		    vdev_label_offset(psize, l, 0)) != sizeof (label)) {
+			(void) fprintf(stderr, "failed to read label %d\n", l);
+			continue;
+		}
+
+		if (nvlist_unpack(buf, buflen, &config, 0) != 0) {
+			(void) fprintf(stderr, "failed to unpack label %d\n", l);
+		} else {
+			if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) != 0)
+				continue;
+			if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &g) != 0)
+				continue;
+			if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE, &state) != 0)
+				continue;
+
+			if (state == POOL_STATE_DESTROYED)
+				continue;
+			if (pguid == 0)
+				pguid = g;
+			else if (pguid != g) {
+				fprintf(stderr, "pool guid mismatch between labels\n");
+				exit(1);
+			}
+			if (txg > best_txg) {
+				if (best)
+					nvlist_free(best);
+				best = config;
+				best_txg = txg;
+			} else {
+				nvlist_free(config);
+			}
+			found++;
+		}
+	}
+
+	if (found < 3)
+		exit(1);
+
+	free(path);
+	(void) close(fd);
+	return best;
+}
+
+static int
+build_vdev(nvlist_t *vdev, uint64_t vguid, uint64_t dguid)
+{
+	char dir[64];
+	char *type;
+	uint64_t cguid;
+	nvlist_t **child;
+	uint_t nc;
+	int i, ready = 0;
+	int ret = 0;
+
+	sprintf(dir, "%llu", (u_longlong_t)vguid);
+	if (mkdir(dir, 0755) < 0 && errno != EEXIST) {
+		fprintf(stderr, "failed to mkdir %s: %s\n", dir, strerror(errno));
+		exit(1);
+	}
+	if (chdir(dir) < 0) {
+		fprintf(stderr, "failed to enter %s: %s\n", dir, strerror(errno));
+		exit(1);
+	}
+
+	if (nvlist_lookup_string(vdev, ZPOOL_CONFIG_TYPE, &type) != 0) {
+		fprintf(stderr, "fail to get vdev type\n");
+		exit(1);
+	}
+
+	if (dguid == vguid) {
+		ready = 1;
+		ret = 1;
+	} else if (strcmp(type, "disk") != 0 && strcmp(type, "file") != 0) {
+		int found = 0;
+
+		if (nvlist_lookup_nvlist_array(vdev, ZPOOL_CONFIG_CHILDREN, &child, &nc) != 0) {
+			fprintf(stderr, "fail to get child vdev\n");
+			exit(1);
+		}
+		for (i = 0; i < nc; i++) {
+			if (nvlist_lookup_uint64(child[i], ZPOOL_CONFIG_GUID, &cguid) != 0) {
+				fprintf(stderr, "failed to get child guid\n");
+				exit(1);
+			}
+			if ((ret = build_vdev(child[i], cguid, dguid)))
+				break;
+		}
+		if (ret) {
+			for (i = 0; i < nc; i++) {
+				struct stat sbuf;
+				char path[64];
+				if (nvlist_lookup_uint64(child[i], ZPOOL_CONFIG_GUID, &cguid) != 0) {
+					fprintf(stderr, "failed to get child guid\n");
+					exit(1);
+				}
+				sprintf(path, "%llu/ready", (u_longlong_t)cguid);
+				if (stat(path, &sbuf) == 0)
+					found++;
+			}
+			if (found == nc)
+				ready = 1;
+		}
+	}
+
+	if (ready && close(open("ready", O_WRONLY|O_CREAT, 0644)) < 0) {
+		fprintf(stderr, "failed to create \"ready\"\n");
+		exit(1);
+	}
+	chdir("..");
+	return ret;
+}
+
+static void
+build_tree(nvlist_t *config)
+{
+	DIR *dfd;
+	struct dirent *dirent;
+	nvlist_t *vdev;
+	uint64_t pguid, vguid, dguid, nc;
+	char *name;
+	int found = 0;
+	int fd;
+	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &vdev) != 0 ||
+	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN, &nc) != 0 ||
+	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pguid) != 0 ||
+	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_TOP_GUID, &vguid) != 0 ||
+	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, &dguid) != 0 ||
+	    nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME, &name) != 0) {
+		fprintf(stderr, "fail to parse pool config\n");
+		exit(1);
+	}
+
+	/* make pool root dir and cd into it */
+	if (mkdir(name, 0755) < 0 && errno != EEXIST) {
+		fprintf(stderr, "failed to mkdir %s: %s\n", name, strerror(errno));
+		exit(1);
+	}
+	if (chdir(name) < 0) {
+		fprintf(stderr, "failed to enter %s: %s\n", name, strerror(errno));
+		exit(1);
+	}
+
+	/* write pool_guid, TODO: we need to check pool_guid is correct */
+	if ((fd = open("pool_guid", O_WRONLY|O_CREAT|O_EXCL, 0644)) > 0) {
+		char u[64];
+		sprintf(u, "%llu", (u_longlong_t)pguid);
+		write(fd, u, strlen(u));
+		close(fd);
+	}
+
+	/* decend into top level vdev */
+	build_vdev(vdev, vguid, dguid);
+
+	dfd = opendir(".");
+	while ((dirent = readdir(dfd)) != NULL) {
+		struct stat sbuf;
+		char path[64];
+		if (strcmp(dirent->d_name, ".") == 0 || strcmp(dirent->d_name, "..") == 0)
+			continue;
+		if (snprintf(path, 64, "%s/ready", dirent->d_name) >= 64)
+			continue;
+		if (stat(path, &sbuf) == 0)
+			found++;
+	}
+	closedir(dfd);
+
+	if ((found == nc) && close(open("ready", O_WRONLY|O_CREAT, 0644)) < 0) {
+		fprintf(stderr, "failed to create \"ready\"\n");
+		exit(1);
+	}
+}
+
+int
+main(int argc, char **argv)
+{
+	nvlist_t *config;
+	if (argc < 2) {
+		fprintf(stderr, "Usage: %s <dev>\n", argv[0]);
+		exit(1);
+	}
+	config = get_config(argv[1]);
+	if (!config)
+		return (0);
+
+	if (mkdir(ZPOOL_PATH, 0755) < 0 && errno != EEXIST) {
+		fprintf(stderr, "failed to mkdir %s: %s\n", ZPOOL_PATH, strerror(errno));
+		exit(1);
+	}
+	if (chdir(ZPOOL_PATH) < 0) {
+		fprintf(stderr, "failed to enter %s: %s\n", ZPOOL_PATH, strerror(errno));
+		exit(1);
+	}
+	build_tree(config);
+	nvlist_free(config);
+	return (0);
+}

configure.ac

@@ -113,6 +113,7 @@ AC_CONFIG_FILES([
 	cmd/arc_summary/Makefile
 	cmd/zed/Makefile
 	cmd/raidz_test/Makefile
+	cmd/zready/Makefile
 	contrib/Makefile
 	contrib/bash_completion.d/Makefile
 	contrib/dracut/Makefile

etc/systemd/system/.gitignore

@@ -1,3 +1,4 @@
 *.service
 *.target
 *.preset
+*.path

etc/systemd/system/Makefile.am

@@ -7,7 +7,9 @@ systemdunit_DATA = \
 	zfs-import-scan.service \
 	zfs-mount.service \
 	zfs-share.service \
-	zfs.target
+	zfs.target \
+	[email protected] \
+	[email protected]
 
 EXTRA_DIST = \
 	$(top_srcdir)/etc/systemd/system/zfs-zed.service.in \
@@ -16,6 +18,8 @@ EXTRA_DIST = \
 	$(top_srcdir)/etc/systemd/system/zfs-mount.service.in \
 	$(top_srcdir)/etc/systemd/system/zfs-share.service.in \
 	$(top_srcdir)/etc/systemd/system/zfs.target.in \
+	$(top_srcdir)/etc/systemd/system/[email protected] \
+	$(top_srcdir)/etc/systemd/system/[email protected] \
 	$(top_srcdir)/etc/systemd/system/50-zfs.preset.in
 
 $(systemdunit_DATA) $(systemdpreset_DATA):%:%.in

etc/systemd/system/zpool@.path.in

@@ -0,0 +1,7 @@
+[Unit]
+Description=zpool ready path
+DefaultDependencies=no
+
+[Path]
+PathExists=/dev/zpool/%i/ready
+Unit=zpool@%i.service