IFp4: Don't rely on disk IDs and always use vdev guids, which means always look

up for components by reading metadata. This might be slower when there are big
number of disks in the system, but is definiately more reliable.

1 files changed, 69 insertions, 219 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
index f151f83..54ba8bd 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
@@ -229,22 +229,6 @@ vdev_geom_worker(void *arg)
 	}
 }
 
-static char *
-vdev_geom_get_id(struct g_consumer *cp)
-{
-	char *id;
-	int len;
-
-	g_topology_assert_not();
-	len = DISK_IDENT_SIZE;
-	id = kmem_zalloc(len, KM_SLEEP);
-	if (g_io_getattr("GEOM::ident", cp, &len, id) != 0) {
-		kmem_free(id, DISK_IDENT_SIZE);
-		return (NULL);
-	}
-	return (id);
-}
-
 static uint64_t
 nvlist_get_guid(nvlist_t *list)
 {
@@ -261,79 +245,6 @@ nvlist_get_guid(nvlist_t *list)
 	return (0);
 }
 
-static char *
-nvlist_get_devid(nvlist_t *list, uint64_t guid)
-{
-	nvpair_t *elem = NULL;
-	int progress;
-	char *id;
-
-	progress = 0;
-	id = NULL;
-
-	while ((elem = nvlist_next_nvpair(list, elem)) != NULL) {
-		switch (nvpair_type(elem)) {
-		case DATA_TYPE_STRING:
-		    {
-			char *value;
-
-			VERIFY(nvpair_value_string(elem, &value) == 0);
-			if (strcmp(nvpair_name(elem), "type") == 0 &&
-			    strcmp(value, "disk") == 0) {
-				progress |= 0x01;
-			} else if (strcmp(nvpair_name(elem), "devid") == 0) {
-				progress |= 0x02;
-				id = value;
-			}
-			break;
-		    }
-		case DATA_TYPE_UINT64:
-		    {
-			uint64_t value;
-
-			VERIFY(nvpair_value_uint64(elem, &value) == 0);
-			if (strcmp(nvpair_name(elem), "guid") == 0 &&
-			    value == guid) {
-				progress |= 0x04;
-			}
-			break;
-		    }
-		case DATA_TYPE_NVLIST:
-		    {
-			nvlist_t *value;
-			char *lid;
-
-			VERIFY(nvpair_value_nvlist(elem, &value) == 0);
-			lid = nvlist_get_devid(value, guid);
-			if (lid != NULL)
-				return (lid);
-			break;
-		    }
-		case DATA_TYPE_NVLIST_ARRAY:
-		    {
-			nvlist_t **value;
-			u_int c, count;
-			char *lid;
-
-			VERIFY(nvpair_value_nvlist_array(elem, &value,
-			    &count) == 0);
-
-			for (c = 0; c < count; c++) {
-				lid = nvlist_get_devid(value[c], guid);
-				if (lid != NULL)
-					return (lid);
-			}
-			break;
-		    }
-		}
-		if (progress == 0x07)
-			break;
-	}
-	if (progress != 0x07)
-		id = NULL;
-	return (id);
-}
-
 static int
 vdev_geom_io(struct g_consumer *cp, int cmd, void *data, off_t offset, off_t size)
 {
@@ -368,8 +279,8 @@ vdev_geom_io(struct g_consumer *cp, int cmd, void *data, off_t offset, off_t siz
 	return (error);
 }
 
-static char *
-vdev_geom_read_id(struct g_consumer *cp)
+static uint64_t
+vdev_geom_read_guid(struct g_consumer *cp)
 {
 	struct g_provider *pp;
 	vdev_label_t *label;
@@ -377,7 +288,7 @@ vdev_geom_read_id(struct g_consumer *cp)
 	size_t buflen;
 	uint64_t psize;
 	off_t offset, size;
-	char *id;
+	uint64_t guid;
 	int error, l, len;
 
 	g_topology_assert_not();
@@ -390,13 +301,12 @@ vdev_geom_read_id(struct g_consumer *cp)
 	size = sizeof(*label) + pp->sectorsize -
 	    ((sizeof(*label) - 1) % pp->sectorsize) - 1;
 
-	id = NULL;
+	guid = 0;
 	label = kmem_alloc(size, KM_SLEEP);
 	buflen = sizeof(label->vl_vdev_phys.vp_nvlist);
 
-	for (l = 0; l < VDEV_LABELS && id == NULL; l++) {
+	for (l = 0; l < VDEV_LABELS; l++) {
 		nvlist_t *config = NULL;
-		uint64_t guid;
 
 		offset = vdev_label_offset(psize, l, 0);
 		if ((offset % pp->sectorsize) != 0)
@@ -411,38 +321,19 @@ vdev_geom_read_id(struct g_consumer *cp)
 			continue;
 
 		guid = nvlist_get_guid(config);
-		if (guid == 0) {
-			nvlist_free(config);
-			continue;
-		}
-		id = nvlist_get_devid(config, guid);
-		if (id != NULL) {
-			char *tmp;
-
-			tmp = kmem_zalloc(DISK_IDENT_SIZE, KM_SLEEP);
-			strlcpy(tmp, id, DISK_IDENT_SIZE);
-			id = tmp;
-		}
-
 		nvlist_free(config);
+		if (guid != 0)
+			break;
 	}
 
 	kmem_free(label, size);
-	if (id != NULL)
-		ZFS_LOG(1, "ID of %s: %s", pp->name, id);
-	return (id);
-}
-
-static void
-vdev_geom_free_id(char *id)
-{
-
-	if (id != NULL)
-		kmem_free(id, DISK_IDENT_SIZE);
+	if (guid != 0)
+		ZFS_LOG(1, "guid for %s is %ju", pp->name, (uintmax_t)guid);
+	return (guid);
 }
 
 struct vdev_geom_find {
-	const char *id;
+	uint64_t guid;
 	int write;
 	struct g_consumer *cp;
 };
@@ -456,14 +347,14 @@ vdev_geom_taste_orphan(struct g_consumer *cp)
 }
 
 static void
-vdev_geom_attach_by_id_event(void *arg, int flags __unused)
+vdev_geom_attach_by_guid_event(void *arg, int flags __unused)
 {
 	struct vdev_geom_find *ap;
 	struct g_class *mp;
 	struct g_geom *gp, *zgp;
 	struct g_provider *pp;
 	struct g_consumer *zcp;
-	char *id;
+	uint64_t guid;
 
 	g_topology_assert();
 
@@ -474,42 +365,6 @@ vdev_geom_attach_by_id_event(void *arg, int flags __unused)
 	zgp->orphan = vdev_geom_taste_orphan;
 	zcp = g_new_consumer(zgp);
 
-	/* First round tries to get provider's ID without reading metadata. */
-	LIST_FOREACH(mp, &g_classes, class) {
-		if (mp == &zfs_vdev_class)
-			continue;
-		LIST_FOREACH(gp, &mp->geom, geom) {
-			if (gp->flags & G_GEOM_WITHER)
-				continue;
-			LIST_FOREACH(pp, &gp->provider, provider) {
-				if (pp->flags & G_PF_WITHER)
-					continue;
-				g_attach(zcp, pp);
-				if (g_access(zcp, 1, 0, 0) != 0) {
-					g_detach(zcp);
-					continue;
-				}
-				g_topology_unlock();
-				id = vdev_geom_get_id(zcp);
-				g_topology_lock();
-				g_access(zcp, -1, 0, 0);
-				g_detach(zcp);
-				if (id == NULL || strcmp(id, ap->id) != 0) {
-					vdev_geom_free_id(id);
-					continue;
-				}
-				vdev_geom_free_id(id);
-				ap->cp = vdev_geom_attach(pp, ap->write);
-				if (ap->cp == NULL) {
-					printf("ZFS WARNING: Cannot open %s "
-					    "for writting.\n", pp->name);
-					continue;
-				}
-				goto end;
-			}
-		}
-	}
-	/* Second round looks for ID by reading ZFS metadata. */
 	LIST_FOREACH(mp, &g_classes, class) {
 		if (mp == &zfs_vdev_class)
 			continue;
@@ -525,15 +380,12 @@ vdev_geom_attach_by_id_event(void *arg, int flags __unused)
 					continue;
 				}
 				g_topology_unlock();
-				id = vdev_geom_read_id(zcp);
+				guid = vdev_geom_read_guid(zcp);
 				g_topology_lock();
 				g_access(zcp, -1, 0, 0);
 				g_detach(zcp);
-				if (id == NULL || strcmp(id, ap->id) != 0) {
-					vdev_geom_free_id(id);
+				if (guid != ap->guid)
 					continue;
-				}
-				vdev_geom_free_id(id);
 				ap->cp = vdev_geom_attach(pp, ap->write);
 				if (ap->cp == NULL) {
 					printf("ZFS WARNING: Cannot open %s "
@@ -551,26 +403,53 @@ end:
 }
 
 static struct g_consumer *
-vdev_geom_attach_by_id(const char *id, int write)
+vdev_geom_attach_by_guid(uint64_t guid, int write)
 {
 	struct vdev_geom_find *ap;
 	struct g_consumer *cp;
 
 	ap = kmem_zalloc(sizeof(*ap), KM_SLEEP);
-	ap->id = id;
+	ap->guid = guid;
 	ap->write = write;
-	g_waitfor_event(vdev_geom_attach_by_id_event, ap, M_WAITOK, NULL);
+	g_waitfor_event(vdev_geom_attach_by_guid_event, ap, M_WAITOK, NULL);
 	cp = ap->cp;
 	kmem_free(ap, sizeof(*ap));
 	return (cp);
 }
 
 static struct g_consumer *
-vdev_geom_open_by_path_and_devid(vdev_t *vd)
+vdev_geom_open_by_guid(vdev_t *vd)
+{
+	struct g_consumer *cp;
+	char *buf;
+	size_t len;
+
+	ZFS_LOG(1, "Searching by guid [%ju].", (uintmax_t)vd->vdev_guid);
+	cp = vdev_geom_attach_by_guid(vd->vdev_guid, !!(spa_mode & FWRITE));
+	if (cp != NULL) {
+		len = strlen(cp->provider->name) + strlen("/dev/") + 1;
+		buf = kmem_alloc(len, KM_SLEEP);
+	
+		snprintf(buf, len, "/dev/%s", cp->provider->name);
+		spa_strfree(vd->vdev_path);
+		vd->vdev_path = buf;
+
+		ZFS_LOG(1, "Attach by guid [%ju] succeeded, provider %s.",
+		    (uintmax_t)vd->vdev_guid, vd->vdev_path);
+	} else {
+		ZFS_LOG(1, "Search by guid [%ju] failed.",
+		    (uintmax_t)vd->vdev_guid);
+	}
+
+	return (cp);
+}
+
+static struct g_consumer *
+vdev_geom_open_by_path(vdev_t *vd, int check_guid)
 {
 	struct g_provider *pp;
 	struct g_consumer *cp;
-	char *id;
+	uint64_t guid;
 
 	cp = NULL;
 	g_topology_lock();
@@ -578,20 +457,20 @@ vdev_geom_open_by_path_and_devid(vdev_t *vd)
 	if (pp != NULL) {
 		ZFS_LOG(1, "Found provider by name %s.", vd->vdev_path);
 		cp = vdev_geom_attach(pp, !!(spa_mode & FWRITE));
-		if (cp != NULL && vd->vdev_devid != NULL) {
+		if (cp != NULL && check_guid) {
 			g_topology_unlock();
-			id = vdev_geom_get_id(cp);
+			guid = vdev_geom_read_guid(cp);
 			g_topology_lock();
-			if (id == NULL || strcmp(id, vd->vdev_devid) != 0) {
+			if (guid != vd->vdev_guid) {
 				vdev_geom_detach(cp, 0);
 				cp = NULL;
-				ZFS_LOG(1, "ID mismatch for provider %s: "
-				    "[%s]!=[%s].", vd->vdev_path,
-				    vd->vdev_devid, id);
-			} else
-				ZFS_LOG(1, "ID match for provider %s.",
+				ZFS_LOG(1, "guid mismatch for provider %s: "
+				    "%ju != %ju.", vd->vdev_path,
+				    (uintmax_t)vd->vdev_guid, (uintmax_t)guid);
+			} else {
+				ZFS_LOG(1, "guid match for provider %s.",
 				    vd->vdev_path);
-			vdev_geom_free_id(id);
+			}
 		}
 	}
 	g_topology_unlock();
@@ -599,37 +478,6 @@ vdev_geom_open_by_path_and_devid(vdev_t *vd)
 	return (cp);
 }
 
-static struct g_consumer *
-vdev_geom_open_by_devid(vdev_t *vd)
-{
-	struct g_consumer *cp;
-	char *buf;
-	size_t len;
-
-	/*
-	 * We can't search by devid if it's missing.
-	 */
-	if (vd->vdev_devid == NULL)
-		return (NULL);
-
-	ZFS_LOG(1, "Searching by ID [%s].", vd->vdev_devid);
-	cp = vdev_geom_attach_by_id(vd->vdev_devid, !!(spa_mode & FWRITE));
-	if (cp != NULL) {
-		len = strlen(cp->provider->name) + strlen("/dev/") + 1;
-		buf = kmem_alloc(len, KM_SLEEP);
-	
-		snprintf(buf, len, "/dev/%s", cp->provider->name);
-		spa_strfree(vd->vdev_path);
-		vd->vdev_path = buf;
-
-		ZFS_LOG(1, "Attach by ID [%s] succeeded, provider %s.",
-		    vd->vdev_devid, vd->vdev_path);
-	} else
-		ZFS_LOG(1, "Search by ID [%s] failed.", vd->vdev_devid);
-
-	return (cp);
-}
-
 static int
 vdev_geom_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
 {
@@ -650,21 +498,23 @@ vdev_geom_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
 
 	if ((owned = mtx_owned(&Giant)))
 		mtx_unlock(&Giant);
-	cp = vdev_geom_open_by_path_and_devid(vd);
+	cp = vdev_geom_open_by_path(vd, 0);
 	if (cp == NULL) {
 		/*
-		 * The device at vd->vdev_path doesn't have the right devid.
+		 * The device at vd->vdev_path doesn't have the expected guid.
 		 * The disks might have merely moved around so try all other
-		 * geom providers to find one with the right devid.
+		 * geom providers to find one with the right guid.
 		 */
-		cp = vdev_geom_open_by_devid(vd);
-		if (cp == NULL) {
-			ZFS_LOG(1, "Provider %s not found.", vd->vdev_path);
-			vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
-			if (owned)
-				mtx_lock(&Giant);
-			return (EACCES);
-		}
+		cp = vdev_geom_open_by_guid(vd);
+	}
+	if (cp == NULL)
+		cp = vdev_geom_open_by_path(vd, 1);
+	if (cp == NULL) {
+		ZFS_LOG(1, "Provider %s not found.", vd->vdev_path);
+		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
+		if (owned)
+			mtx_lock(&Giant);
+		return (EACCES);
 	}
 	if (owned)
 		mtx_lock(&Giant);