fsrvp: add server state storage back-end

MS-FSRVP specifies:
  the server MUST persist all state information into an implementation-
  specific configuration store.

This change adds a fss_srv TDB database to preserve FSRVP server state,
with the following keys used to track shadow copy state and hierarchy:
- sc_set/<shadow copy set GUID>
  A shadow copy set tracks a collection of zero or more shadow copies,
  as initiated by a StartShadowCopySet FSRVP client request.
- sc_set/<shadow copy set GUID>/sc/<shadow copy GUID>
  A shadow copy defines information about a snapshot base volume, the
  snapshot path, and a collection of share maps. It is initiated by an
  AddToShadowCopySet client request.
- sc_set/<shadow copy set GUID>/sc/<shadow copy GUID>/smap/<smap GUID>
  A share map tracks new shares that are created to expose shadow
  copies.

All structures are marshalled into on-disk format using the previously
added fsrvp_state IDL library.

Signed-off-by: David Disseldorp <ddiss@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

source3/rpc_server/fss/srv_fss_private.h

@@ -0,0 +1,92 @@
+/*
+ * File Server Remote VSS Protocol (FSRVP) server state
+ *
+ * Copyright (C) David Disseldorp	2012-2015
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _SRV_FSS_PRIVATE_H_
+#define _SRV_FSS_PRIVATE_H_
+
+#define FSS_DB_NAME "srv_fss.tdb"
+
+struct fss_sc_smap {
+	struct fss_sc_smap *next, *prev;
+	char *share_name;		/* name of the base file share */
+	char *sc_share_name;		/* share exposing the shadow copy */
+	char *sc_share_comment;
+	bool is_exposed;		/* whether shadow copy is exposed */
+};
+
+struct fss_sc {
+	struct fss_sc *next, *prev;
+	struct GUID id;			/* GUID of the shadow copy */
+	char *id_str;
+	char *volume_name;		/* name uniquely identifying on the
+					 * server object store on which this
+					 * shadow copy is created. */
+	char *sc_path;			/* path exposing the shadow copy */
+	time_t create_ts;		/* timestamp of client initiation */
+	struct fss_sc_smap *smaps;	/* shares mapped to this shadow copy */
+	uint32_t smaps_count;
+	struct fss_sc_set *sc_set;	/* parent shadow copy set */
+};
+
+/*
+ * 3.1.1.2: Per ShadowCopySet
+ * The status of the shadow copy set. This MUST be one of "Started", "Added",
+ * "CreationInProgress", "Committed", "Exposed", or "Recovered".
+ */
+enum fss_sc_state {
+	FSS_SC_STARTED,
+	FSS_SC_ADDED,
+	FSS_SC_CREATING,
+	FSS_SC_COMMITED,
+	FSS_SC_EXPOSED,
+	FSS_SC_RECOVERED,
+};
+struct fss_sc_set {
+	struct fss_sc_set *next, *prev;
+	struct GUID id;			/* GUID of the shadow copy set. */
+	char *id_str;
+	enum fss_sc_state state;	/* status of the shadow copy set */
+	uint32_t context;		/* attributes used for set creation */
+	struct fss_sc *scs;		/* list of ShadowCopy objects */
+	uint32_t scs_count;
+};
+
+struct fss_global {
+	TALLOC_CTX *mem_ctx;		/* parent mem ctx for sc sets */
+	char *db_path;
+	uint32_t min_vers;
+	uint32_t max_vers;
+	bool ctx_set;			/* whether client has set context */
+	uint32_t cur_ctx;
+	struct fss_sc_set *sc_sets;
+	uint32_t sc_sets_count;
+	struct tevent_timer *seq_tmr;	/* time to wait between client reqs */
+};
+
+NTSTATUS fss_state_store(TALLOC_CTX *mem_ctx,
+			 struct fss_sc_set *sc_sets,
+			 uint32_t sc_sets_count,
+			 const char *db_path);
+
+NTSTATUS fss_state_retrieve(TALLOC_CTX *mem_ctx,
+			    struct fss_sc_set **sc_sets,
+			    uint32_t *sc_sets_count,
+			    const char *db_path);
+
+#endif /*_SRV_FSS_PRIVATE_H_ */

source3/rpc_server/fss/srv_fss_state.c

@@ -0,0 +1,698 @@
+/*
+ * File Server Remote VSS Protocol (FSRVP) persistent server state
+ *
+ * Copyright (C) David Disseldorp	2012-2015
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <fcntl.h>
+#include "source3/include/includes.h"
+#include "source3/include/util_tdb.h"
+#include "lib/dbwrap/dbwrap.h"
+#include "lib/dbwrap/dbwrap_open.h"
+#include "librpc/ndr/libndr.h"
+#include "librpc/gen_ndr/ndr_fsrvp_state.h"
+#include "srv_fss_private.h"
+
+#define FSS_DB_KEY_VERSION "db_version"
+#define FSS_DB_KEY_CONTEXT "context"
+#define FSS_DB_KEY_SC_SET_COUNT "sc_set_count"
+#define FSS_DB_KEY_PFX_SC_SET "sc_set/"
+#define FSS_DB_KEY_PFX_SC "sc/"
+#define FSS_DB_KEY_PFX_SMAP "smap/"
+
+static NTSTATUS fss_state_smap_store(TALLOC_CTX *mem_ctx,
+				     struct db_context *db,
+				     const char *sc_key_str,
+				     struct fss_sc_smap *smap)
+{
+	NTSTATUS status;
+	TDB_DATA val;
+	const char *smap_key_str;
+	struct fsrvp_state_smap smap_state;
+	enum ndr_err_code ndr_ret;
+	DATA_BLOB smap_state_blob;
+
+	/* becomes sc_set/@sc_set_id/sc/@sc_id/smap/@sc_share_name */
+	smap_key_str = talloc_asprintf(mem_ctx, "%s/%s%s", sc_key_str,
+				       FSS_DB_KEY_PFX_SMAP,
+				       smap->sc_share_name);
+	if (smap_key_str == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	smap_state.share_name = smap->share_name;
+	smap_state.sc_share_name = smap->sc_share_name;
+	/* @smap->sc_share_comment may be null if not exposed. */
+	if (smap->sc_share_comment != NULL) {
+		smap_state.sc_share_comment = smap->sc_share_comment;
+	} else {
+		smap_state.sc_share_comment = "";
+	}
+	smap_state.is_exposed = smap->is_exposed;
+
+	ndr_ret = ndr_push_struct_blob(&smap_state_blob, mem_ctx,
+				       &smap_state,
+				(ndr_push_flags_fn_t)ndr_push_fsrvp_state_smap);
+	if (ndr_ret != NDR_ERR_SUCCESS) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	val.dsize = smap_state_blob.length;
+	val.dptr = smap_state_blob.data;
+
+	status = dbwrap_store(db, string_term_tdb_data(smap_key_str), val, 0);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS fss_state_sc_store(TALLOC_CTX *mem_ctx,
+				   struct db_context *db,
+				   const char *sc_set_key_str,
+				   struct fss_sc *sc)
+{
+	NTSTATUS status;
+	TDB_DATA val;
+	const char *sc_key_str;
+	struct fsrvp_state_sc sc_state;
+	struct fss_sc_smap *smap;
+	enum ndr_err_code ndr_ret;
+	DATA_BLOB sc_state_blob;
+
+	/* becomes sc_set/@sc_set.id/sc/@sc_id */
+	sc_key_str = talloc_asprintf(mem_ctx, "%s/%s%s", sc_set_key_str,
+				     FSS_DB_KEY_PFX_SC, sc->id_str);
+	if (sc_key_str == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	sc_state.id_str = sc->id_str;
+	sc_state.volume_name = sc->volume_name;
+	/* @sc->sc_path may be null if not committed, store empty str */
+	sc_state.sc_path = (sc->sc_path ? sc->sc_path : "");
+	sc_state.create_ts = sc->create_ts;
+	sc_state.smaps_count = sc->smaps_count;
+
+	ndr_ret = ndr_push_struct_blob(&sc_state_blob, mem_ctx,
+				       &sc_state,
+				(ndr_push_flags_fn_t)ndr_push_fsrvp_state_sc);
+	if (ndr_ret != NDR_ERR_SUCCESS) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	val.dsize = sc_state_blob.length;
+	val.dptr = sc_state_blob.data;
+
+	status = dbwrap_store(db, string_term_tdb_data(sc_key_str), val, 0);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	for (smap = sc->smaps; smap; smap = smap->next) {
+		status = fss_state_smap_store(mem_ctx, db, sc_key_str, smap);
+		if (!NT_STATUS_IS_OK(status)) {
+			return status;
+		}
+	}
+
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS fss_state_sc_set_store(TALLOC_CTX *mem_ctx,
+				       struct db_context *db,
+				       struct fss_sc_set *sc_set)
+{
+	NTSTATUS status;
+	TDB_DATA val;
+	const char *sc_set_key_str;
+	struct fss_sc *sc;
+	struct fsrvp_state_sc_set sc_set_state;
+	DATA_BLOB sc_set_state_blob;
+	enum ndr_err_code ndr_ret;
+
+	sc_set_key_str = talloc_asprintf(mem_ctx, "%s%s",
+					 FSS_DB_KEY_PFX_SC_SET,
+					 sc_set->id_str);
+	if (sc_set_key_str == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	sc_set_state.id_str = sc_set->id_str;
+	sc_set_state.state = sc_set->state;
+	sc_set_state.context = sc_set->context;
+	sc_set_state.scs_count = sc_set->scs_count;
+
+	ndr_ret = ndr_push_struct_blob(&sc_set_state_blob, mem_ctx,
+				       &sc_set_state,
+			(ndr_push_flags_fn_t)ndr_push_fsrvp_state_sc_set);
+	if (ndr_ret != NDR_ERR_SUCCESS) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	val.dsize = sc_set_state_blob.length;
+	val.dptr = sc_set_state_blob.data;
+
+	status = dbwrap_store(db, string_term_tdb_data(sc_set_key_str), val, 0);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	for (sc = sc_set->scs; sc; sc = sc->next) {
+		status = fss_state_sc_store(mem_ctx, db, sc_set_key_str, sc);
+		if (!NT_STATUS_IS_OK(status)) {
+			return status;
+		}
+	}
+
+	return NT_STATUS_OK;
+}
+
+/*
+ * write out the current fsrvp server state to a TDB. This clears any content
+ * currently written to the TDB.
+ */
+_PRIVATE_ NTSTATUS fss_state_store(TALLOC_CTX *mem_ctx,
+			 struct fss_sc_set *sc_sets,
+			 uint32_t sc_sets_count,
+			 const char *db_path)
+{
+	TALLOC_CTX *tmp_ctx;
+	struct db_context *db;
+	NTSTATUS status;
+	int ret;
+	struct fss_sc_set *sc_set;
+
+	tmp_ctx = talloc_new(mem_ctx);
+	if (tmp_ctx == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	db = db_open(tmp_ctx, db_path, 0, TDB_DEFAULT,  O_RDWR | O_CREAT,
+		     0600, DBWRAP_LOCK_ORDER_1, DBWRAP_FLAG_NONE);
+	if (db == NULL) {
+		DEBUG(0, ("Failed to open fss state database %s\n", db_path));
+		status = NT_STATUS_ACCESS_DENIED;
+		goto err_ctx_free;
+	}
+
+	ret = dbwrap_wipe(db);
+	if (ret != 0) {
+		status = NT_STATUS_UNSUCCESSFUL;
+		goto err_db_free;
+	}
+
+	status = dbwrap_store_int32_bystring(db, FSS_DB_KEY_VERSION,
+					     FSRVP_STATE_DB_VERSION);
+	if (!NT_STATUS_IS_OK(status)) {
+		goto err_db_free;
+	}
+
+	ret = dbwrap_transaction_start(db);
+	if (ret != 0) {
+		status = NT_STATUS_UNSUCCESSFUL;
+		goto err_db_free;
+	}
+
+	status = dbwrap_store_int32_bystring(db, FSS_DB_KEY_SC_SET_COUNT,
+					     sc_sets_count);
+	if (!NT_STATUS_IS_OK(status)) {
+		status = NT_STATUS_UNSUCCESSFUL;
+		goto err_trans_cancel;
+	}
+
+	for (sc_set = sc_sets; sc_set; sc_set = sc_set->next) {
+		status = fss_state_sc_set_store(tmp_ctx, db, sc_set);
+		if (!NT_STATUS_IS_OK(status)) {
+			goto err_trans_cancel;
+		}
+	}
+
+	ret = dbwrap_transaction_commit(db);
+	if (ret != 0) {
+		status = NT_STATUS_UNSUCCESSFUL;
+		goto err_trans_cancel;
+	}
+
+	talloc_free(db);
+	talloc_free(tmp_ctx);
+	return NT_STATUS_OK;
+
+err_trans_cancel:
+	dbwrap_transaction_cancel(db);
+err_db_free:
+	talloc_free(db);
+err_ctx_free:
+	talloc_free(tmp_ctx);
+	return status;
+}
+
+static NTSTATUS fss_state_smap_retrieve(TALLOC_CTX *mem_ctx,
+					TDB_DATA *key,
+					TDB_DATA *val,
+					struct fss_sc_smap **smap_out)
+{
+	struct fss_sc_smap *smap;
+	struct fsrvp_state_smap smap_state;
+	DATA_BLOB smap_state_blob;
+	enum ndr_err_code ndr_ret;
+
+	smap_state_blob.length = val->dsize;
+	smap_state_blob.data = val->dptr;
+
+	ndr_ret = ndr_pull_struct_blob(&smap_state_blob, mem_ctx, &smap_state,
+				(ndr_pull_flags_fn_t)ndr_pull_fsrvp_state_smap);
+	if (ndr_ret != NDR_ERR_SUCCESS) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	smap = talloc_zero(mem_ctx, struct fss_sc_smap);
+	if (smap == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	smap->share_name = talloc_strdup(smap, smap_state.share_name);
+	if (smap->share_name == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* store the full path so that the heirarchy can be rebuilt */
+	smap->sc_share_name = talloc_strdup(smap, (char *)key->dptr);
+	if (smap->sc_share_name == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* sc_share_comment may be empty, keep null in such a case */
+	if (strlen(smap_state.sc_share_comment) > 0) {
+		smap->sc_share_comment = talloc_strdup(smap,
+						smap_state.sc_share_comment);
+		if (smap->sc_share_comment == NULL) {
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+
+	smap->is_exposed = smap_state.is_exposed;
+
+	*smap_out = smap;
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS fss_state_sc_retrieve(TALLOC_CTX *mem_ctx,
+				      TDB_DATA *key,
+				      TDB_DATA *val,
+				      struct fss_sc **sc_out)
+{
+	struct fss_sc *sc;
+	struct fsrvp_state_sc sc_state;
+	DATA_BLOB sc_state_blob;
+	enum ndr_err_code ndr_ret;
+
+	sc_state_blob.length = val->dsize;
+	sc_state_blob.data = val->dptr;
+
+	ndr_ret = ndr_pull_struct_blob(&sc_state_blob, mem_ctx, &sc_state,
+				(ndr_pull_flags_fn_t)ndr_pull_fsrvp_state_sc);
+	if (ndr_ret != NDR_ERR_SUCCESS) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	sc = talloc_zero(mem_ctx, struct fss_sc);
+	if (sc == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* store the full path so that the heirarchy can be rebuilt */
+	sc->id_str = talloc_strdup(sc, (char *)key->dptr);
+	if (sc->id_str == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	sc->volume_name = talloc_strdup(sc, sc_state.volume_name);
+	if (sc->volume_name == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* sc_path may be empty, keep null in such a case */
+	if (strlen(sc_state.sc_path) > 0) {
+		sc->sc_path = talloc_strdup(sc, sc_state.sc_path);
+		if (sc->sc_path == NULL) {
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+	sc->create_ts = sc_state.create_ts;
+	sc->smaps_count = sc_state.smaps_count;
+
+	*sc_out = sc;
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS fss_state_sc_set_retrieve(TALLOC_CTX *mem_ctx,
+					  TDB_DATA *key,
+					  TDB_DATA *val,
+					  struct fss_sc_set **sc_set_out)
+{
+	struct fss_sc_set *sc_set;
+	struct fsrvp_state_sc_set sc_set_state;
+	DATA_BLOB sc_set_state_blob;
+	enum ndr_err_code ndr_ret;
+
+	sc_set_state_blob.length = val->dsize;
+	sc_set_state_blob.data = val->dptr;
+
+	ndr_ret = ndr_pull_struct_blob(&sc_set_state_blob, mem_ctx,
+				       &sc_set_state,
+			(ndr_pull_flags_fn_t)ndr_pull_fsrvp_state_sc_set);
+	if (ndr_ret != NDR_ERR_SUCCESS) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	sc_set = talloc_zero(mem_ctx, struct fss_sc_set);
+	if (sc_set == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* store the full path so that the heirarchy can be rebuilt */
+	sc_set->id_str = talloc_strdup(sc_set, (char *)key->dptr);
+	if (sc_set->id_str == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	sc_set->state = sc_set_state.state;
+	sc_set->context = sc_set_state.context;
+	sc_set->scs_count = sc_set_state.scs_count;
+
+	*sc_set_out = sc_set;
+	return NT_STATUS_OK;
+}
+
+struct fss_traverse_state {
+	TALLOC_CTX *mem_ctx;
+	struct fss_sc_smap *smaps;
+	uint32_t smaps_count;
+	struct fss_sc *scs;
+	uint32_t scs_count;
+	struct fss_sc_set *sc_sets;
+	uint32_t sc_sets_count;
+	NTSTATUS (*smap_retrieve)(TALLOC_CTX *mem_ctx,
+				  TDB_DATA *key,
+				  TDB_DATA *val,
+				  struct fss_sc_smap **smap_out);
+	NTSTATUS (*sc_retrieve)(TALLOC_CTX *mem_ctx,
+				TDB_DATA *key,
+				TDB_DATA *val,
+				struct fss_sc **sc_out);
+	NTSTATUS (*sc_set_retrieve)(TALLOC_CTX *mem_ctx,
+				    TDB_DATA *key,
+				    TDB_DATA *val,
+				    struct fss_sc_set **sc_set_out);
+};
+
+static int fss_state_retrieve_traverse(struct db_record *rec,
+				       void *private_data)
+{
+	NTSTATUS status;
+	struct fss_traverse_state *trv_state
+			= (struct fss_traverse_state *)private_data;
+	TDB_DATA key = dbwrap_record_get_key(rec);
+	TDB_DATA val = dbwrap_record_get_value(rec);
+
+	/* order of checking is important here */
+	if (strstr((char *)key.dptr, FSS_DB_KEY_PFX_SMAP) != NULL) {
+		struct fss_sc_smap *smap;
+		status = trv_state->smap_retrieve(trv_state->mem_ctx,
+						  &key, &val, &smap);
+		if (!NT_STATUS_IS_OK(status)) {
+			return -1;
+		}
+		DLIST_ADD_END(trv_state->smaps, smap, struct fss_sc_smap *);
+		trv_state->smaps_count++;
+	} else if (strstr((char *)key.dptr, FSS_DB_KEY_PFX_SC) != NULL) {
+		struct fss_sc *sc;
+		status = trv_state->sc_retrieve(trv_state->mem_ctx,
+						&key, &val, &sc);
+		if (!NT_STATUS_IS_OK(status)) {
+			return -1;
+		}
+		DLIST_ADD_END(trv_state->scs, sc, struct fss_sc *);
+		trv_state->scs_count++;
+	} else if (strstr((char *)key.dptr, FSS_DB_KEY_PFX_SC_SET) != NULL) {
+		struct fss_sc_set *sc_set;
+		status = trv_state->sc_set_retrieve(trv_state->mem_ctx,
+						    &key, &val, &sc_set);
+		if (!NT_STATUS_IS_OK(status)) {
+			return -1;
+		}
+		DLIST_ADD_END(trv_state->sc_sets, sc_set, struct fss_sc_set *);
+		trv_state->sc_sets_count++;
+	} else {
+		/* global context and db vers */
+		DEBUG(4, ("Ignoring fss srv db entry with key %s\n", key.dptr));
+	}
+
+	return 0;
+}
+
+static bool fss_state_smap_is_child(struct fss_sc *sc,
+				    struct fss_sc_smap *smap)
+{
+	return (strstr(smap->sc_share_name, sc->id_str) != NULL);
+}
+
+static NTSTATUS fss_state_hierarchize_smaps(struct fss_traverse_state *trv_state,
+					    struct fss_sc *sc)
+{
+	struct fss_sc_smap *smap;
+	struct fss_sc_smap *smap_n;
+	uint32_t smaps_moved = 0;
+
+	for (smap = trv_state->smaps; smap; smap = smap_n) {
+		smap_n = smap->next;
+		if (!fss_state_smap_is_child(sc, smap))
+			continue;
+
+		/* smap mem should be owned by parent sc */
+		talloc_steal(sc, smap);
+		DLIST_REMOVE(trv_state->smaps, smap);
+		trv_state->smaps_count--;
+		DLIST_ADD_END(sc->smaps, smap, struct fss_sc_smap *);
+		smaps_moved++;
+
+		/* last component of the tdb key path is the sc share name */
+		SMB_ASSERT(strrchr(smap->sc_share_name, '/') != NULL);
+		smap->sc_share_name = strrchr(smap->sc_share_name, '/') + 1;
+	}
+
+	if (sc->smaps_count != smaps_moved) {
+		DEBUG(0, ("Inconsistent smaps_count, expected %u, moved %u\n",
+			  sc->smaps_count, smaps_moved));
+		return NT_STATUS_UNSUCCESSFUL;
+	}
+
+	return NT_STATUS_OK;
+}
+
+static bool fss_state_sc_is_child(struct fss_sc_set *sc_set,
+				  struct fss_sc *sc)
+{
+	return (strstr(sc->id_str, sc_set->id_str) != NULL);
+}
+
+static NTSTATUS fss_state_hierarchize_scs(struct fss_traverse_state *trv_state,
+					  struct fss_sc_set *sc_set)
+{
+	NTSTATUS status;
+	struct fss_sc *sc;
+	struct fss_sc *sc_n;
+	uint32_t scs_moved = 0;
+
+	for (sc = trv_state->scs; sc; sc = sc_n) {
+		sc_n = sc->next;
+		if (!fss_state_sc_is_child(sc_set, sc))
+			continue;
+
+		/* sc mem should be owned by parent sc_set */
+		talloc_steal(sc_set, sc);
+		DLIST_REMOVE(trv_state->scs, sc);
+		trv_state->scs_count--;
+		DLIST_ADD_END(sc_set->scs, sc, struct fss_sc *);
+		scs_moved++;
+
+		sc->sc_set = sc_set;
+
+		/* last component of the tdb key path is the sc GUID str */
+		SMB_ASSERT(strrchr(sc->id_str, '/') != NULL);
+		sc->id_str = strrchr(sc->id_str, '/') + 1;
+
+		status = GUID_from_string(sc->id_str, &sc->id);
+		if (!NT_STATUS_IS_OK(status)) {
+			goto err_out;
+		}
+
+		status = fss_state_hierarchize_smaps(trv_state, sc);
+		if (!NT_STATUS_IS_OK(status)) {
+			goto err_out;
+		}
+	}
+
+	if (sc_set->scs_count != scs_moved) {
+		DEBUG(0, ("Inconsistent scs_count, expected %u, moved %u\n",
+			  sc_set->scs_count, scs_moved));
+		status = NT_STATUS_UNSUCCESSFUL;
+		goto err_out;
+	}
+
+	return NT_STATUS_OK;
+
+err_out:
+	return status;
+}
+
+static NTSTATUS fss_state_hierarchize(struct fss_traverse_state *trv_state,
+				      struct fss_sc_set **sc_sets,
+				      uint32_t *sc_sets_count)
+{
+	NTSTATUS status;
+	struct fss_sc_set *sc_set;
+	struct fss_sc_set *sc_set_n;
+	uint32_t i = 0;
+
+	*sc_sets = NULL;
+	for (sc_set = trv_state->sc_sets; sc_set; sc_set = sc_set_n) {
+		sc_set_n = sc_set->next;
+		/* sc_set mem already owned by trv_state->mem_ctx */
+		DLIST_REMOVE(trv_state->sc_sets, sc_set);
+		trv_state->sc_sets_count--;
+		DLIST_ADD_END(*sc_sets, sc_set, struct fss_sc_set *);
+		i++;
+
+		/* last component of the tdb key path is the sc_set GUID str */
+		SMB_ASSERT(strrchr(sc_set->id_str, '/') != NULL);
+		sc_set->id_str = strrchr(sc_set->id_str, '/') + 1;
+
+		status = GUID_from_string(sc_set->id_str, &sc_set->id);
+		if (!NT_STATUS_IS_OK(status)) {
+			goto err_out;
+		}
+
+		status = fss_state_hierarchize_scs(trv_state, sc_set);
+		if (!NT_STATUS_IS_OK(status)) {
+			goto err_out;
+		}
+	}
+	*sc_sets_count = i;
+	return NT_STATUS_OK;
+
+err_out:
+	return status;
+}
+
+_PRIVATE_ NTSTATUS fss_state_retrieve(TALLOC_CTX *mem_ctx,
+			    struct fss_sc_set **sc_sets,
+			    uint32_t *sc_sets_count,
+			    const char *db_path)
+{
+	struct db_context *db;
+	NTSTATUS status;
+	struct fss_traverse_state trv_state;
+	int err;
+	int rec_count;
+	int vers;
+	*sc_sets = NULL;
+	*sc_sets_count = 0;
+
+	memset(&trv_state, 0, sizeof(trv_state));
+	trv_state.mem_ctx = talloc_new(mem_ctx);
+	if (trv_state.mem_ctx == NULL) {
+		status = NT_STATUS_NO_MEMORY;
+		goto err_out;
+	}
+
+	/* set callbacks for unmarshalling on-disk structures */
+	trv_state.smap_retrieve = fss_state_smap_retrieve;
+	trv_state.sc_retrieve = fss_state_sc_retrieve;
+	trv_state.sc_set_retrieve = fss_state_sc_set_retrieve;
+
+	db = db_open(trv_state.mem_ctx, db_path, 0, TDB_DEFAULT,
+		     O_RDONLY, 0600, DBWRAP_LOCK_ORDER_1, DBWRAP_FLAG_NONE);
+	err = errno;
+	if ((db == NULL) && (err == ENOENT)) {
+		DEBUG(4, ("fss state TDB does not exist for retrieval\n"));
+		status = NT_STATUS_OK;
+		goto err_ts_free;
+	} else if (db == NULL) {
+		DEBUG(0, ("Failed to open fss state TDB: %s\n",
+			  strerror(err)));
+		status = NT_STATUS_ACCESS_DENIED;
+		goto err_ts_free;
+	}
+
+	status = dbwrap_fetch_int32_bystring(db, FSS_DB_KEY_VERSION,
+					     &vers);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("failed to fetch version from fss state tdb: %s\n",
+			  nt_errstr(status)));
+		goto err_db_free;
+	} else if (vers != FSRVP_STATE_DB_VERSION) {
+		DEBUG(0, ("Unsupported fss tdb version %d, expected %d\n",
+			  vers, FSRVP_STATE_DB_VERSION));
+		status = NT_STATUS_UNSUCCESSFUL;
+		goto err_db_free;
+	}
+
+	status = dbwrap_traverse_read(db,
+				      fss_state_retrieve_traverse,
+				      &trv_state,
+				      &rec_count);
+	if (!NT_STATUS_IS_OK(status)) {
+		goto err_db_free;
+	}
+
+	status = fss_state_hierarchize(&trv_state, sc_sets, sc_sets_count);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("Failed to form fss state heirarchy\n"));
+		goto err_db_free;
+	}
+
+	/* check whether anything was left without a parent */
+	if (trv_state.sc_sets_count != 0) {
+		DEBUG(0, ("%d shadow copy set orphans in %s tdb\n",
+			  trv_state.sc_sets_count, db_path));
+		status = NT_STATUS_UNSUCCESSFUL;
+		goto err_db_free;
+	}
+	if (trv_state.scs_count != 0) {
+		DEBUG(0, ("%d shadow copy orphans in %s tdb\n",
+			  trv_state.scs_count, db_path));
+		status = NT_STATUS_UNSUCCESSFUL;
+		goto err_db_free;
+	}
+	if (trv_state.smaps_count != 0) {
+		DEBUG(0, ("%d share map orphans in %s tdb\n",
+			  trv_state.smaps_count, db_path));
+		status = NT_STATUS_UNSUCCESSFUL;
+		goto err_db_free;
+	}
+	talloc_free(db);
+
+	return NT_STATUS_OK;
+
+err_db_free:
+	talloc_free(db);
+err_ts_free:
+	talloc_free(trv_state.mem_ctx);
+err_out:
+	return status;
+}