From: Jeff Layton <jlay...@redhat.com>
Add a new clustered RADOS recovery backend driver. This uses a common
RADOS object to coordinate a cluster-wide grace period.
Each node in the cluster should be assigned a unique nodeid (uint64_t),
which we then use to check/request a grace period, and determine from
which database to allow recovery.
Change-Id: Ic1ec91f5df7c5cbfa5254c646757b2b29e434dfb
Signed-off-by: Jeff Layton <jlay...@redhat.com>
---
src/SAL/CMakeLists.txt | 3 +-
src/SAL/nfs4_recovery.c | 2 +
src/SAL/recovery/recovery_rados_cluster.c | 203 ++++++++++++++++++++++++++++++
src/include/sal_functions.h | 1 +
4 files changed, 208 insertions(+), 1 deletion(-)
create mode 100644 src/SAL/recovery/recovery_rados_cluster.c
diff --git a/src/SAL/CMakeLists.txt b/src/SAL/CMakeLists.txt
index 115ff04c97ad..8af718949b98 100644
--- a/src/SAL/CMakeLists.txt
+++ b/src/SAL/CMakeLists.txt
@@ -38,6 +38,7 @@ if(USE_RADOS_RECOV)
${sal_STAT_SRCS}
recovery/recovery_rados_kv.c
recovery/recovery_rados_ng.c
+ recovery/recovery_rados_cluster.c
)
endif(USE_RADOS_RECOV)
@@ -46,7 +47,7 @@ add_sanitizers(sal)
if(USE_RADOS_RECOV)
include_directories(${RADOS_INCLUDE_DIR})
- target_link_libraries(sal ${RADOS_LIBRARIES})
+ target_link_libraries(sal rados_grace ${RADOS_LIBRARIES})
endif(USE_RADOS_RECOV)
########### install files ###############
diff --git a/src/SAL/nfs4_recovery.c b/src/SAL/nfs4_recovery.c
index 619352f02575..bcdde4b27b09 100644
--- a/src/SAL/nfs4_recovery.c
+++ b/src/SAL/nfs4_recovery.c
@@ -423,6 +423,8 @@ static int load_backend(const char *name)
rados_kv_backend_init(&recovery_backend);
else if (!strcmp(name, "rados_ng"))
rados_ng_backend_init(&recovery_backend);
+ else if (!strcmp(name, "rados_cluster"))
+ rados_cluster_backend_init(&recovery_backend);
#endif
else if (!strcmp(name, "fs_ng"))
fs_ng_backend_init(&recovery_backend);
diff --git a/src/SAL/recovery/recovery_rados_cluster.c
b/src/SAL/recovery/recovery_rados_cluster.c
new file mode 100644
index 000000000000..92d7b4fc7383
--- /dev/null
+++ b/src/SAL/recovery/recovery_rados_cluster.c
@@ -0,0 +1,203 @@
+/*
+ * vim:noexpandtab:shiftwidth=8:tabstop=8:
+ *
+ * Copyright 2017 Red Hat, Inc. and/or its affiliates.
+ * Author: Jeff Layton <jlay...@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * recovery_rados_cluster: a clustered recovery backing store
+ *
+ * We assume that each node has a unique nodeid, with a corresponding slot in
+ * the grace omap, and a rados_kv store for each server epoch.
+ *
+ * When the grace period is started, call into the rados_grace infrastructure
+ * to determine whether we're in a grace period and from what epoch we're
+ * allowed to recover state. Set the proper oid strings, and load the recovery
+ * db if applicable.
+ *
+ * When trying to lift the grace period, we just call into rados_grace
+ * infrastructure and return true or false based on the result.
+ */
+
+#include "config.h"
+#include <netdb.h>
+#include <rados/librados.h>
+#include <rados_grace.h>
+#include "log.h"
+#include "nfs_core.h"
+#include "sal_functions.h"
+#include "recovery_rados.h"
+
+/* FIXME: Make this configurable -- RADOS_KV param? */
+#define RADOS_GRACE_OID "grace"
+
+static void rados_cluster_init(void)
+{
+ int ret;
+
+ ret = rados_kv_connect(&rados_recov_io_ctx, rados_kv_param.userid,
+ rados_kv_param.ceph_conf, rados_kv_param.pool);
+ if (ret < 0) {
+ LogEvent(COMPONENT_CLIENTID,
+ "Failed to connect to cluster: %d", ret);
+ return;
+ }
+
+ ret = rados_grace_create(rados_recov_io_ctx, RADOS_GRACE_OID);
+ if (ret < 0 && ret != -EEXIST) {
+ LogEvent(COMPONENT_CLIENTID,
+ "Failed to create grace db: %d", ret);
+ rados_kv_shutdown();
+ }
+ return;
+}
+
+/* Try to delete old recovery db */
+static void rados_cluster_cleanup(void)
+{
+ int ret;
+ rados_write_op_t wop;
+
+ if (rados_recov_old_oid[0] == '\0')
+ return;
+
+ wop = rados_create_write_op();
+ rados_write_op_remove(wop);
+ ret = rados_write_op_operate(wop, rados_recov_io_ctx,
+ rados_recov_old_oid, NULL, 0);
+ if (ret)
+ LogEvent(COMPONENT_CLIENTID, "Failed to remove %s: %d",
+ rados_recov_old_oid, ret);
+
+ memset(rados_recov_old_oid, '\0', sizeof(rados_recov_old_oid));
+}
+
+static void rados_cluster_read_clids(nfs_grace_start_t *gsp,
+ add_clid_entry_hook add_clid_entry,
+ add_rfh_entry_hook add_rfh_entry)
+{
+ int ret;
+ uint64_t cur, rec;
+ rados_write_op_t wop;
+ struct pop_args args = {
+ .add_clid_entry = add_clid_entry,
+ .add_rfh_entry = add_rfh_entry,
+ };
+
+ if (gsp) {
+ LogEvent(COMPONENT_CLIENTID,
+ "Clustered rados backend does not support takeover!");
+ return;
+ }
+
+ /* Attempt to join the current grace period */
+ ret = rados_grace_join(rados_recov_io_ctx, RADOS_GRACE_OID,
+ rados_kv_param.nodeid, &cur, &rec);
+ if (ret) {
+ LogEvent(COMPONENT_CLIENTID,
+ "Failed to join grace period: %d", ret);
+ return;
+ }
+
+ /*
+ * Recovery db names are "rec-nnnnnnnn:cccccccccccccccc"
+ *
+ * "rec-" followed by nodeid in 8 chars of hex followed by epoch in
+ * 16 hex digits.
+ */
+ snprintf(rados_recov_oid, sizeof(rados_recov_oid),
+ "rec-%8.8x:%16.16lx", rados_kv_param.nodeid, cur);
+ wop = rados_create_write_op();
+ rados_write_op_create(wop, LIBRADOS_CREATE_IDEMPOTENT, NULL);
+ rados_write_op_omap_clear(wop);
+ ret = rados_write_op_operate(wop, rados_recov_io_ctx,
+ rados_recov_oid, NULL, 0);
+ rados_release_write_op(wop);
+ if (ret < 0) {
+ LogEvent(COMPONENT_CLIENTID, "Failed to create recovery db");
+ return;
+ };
+
+ /*
+ * If we're not in a grace period, then the join failed. No recovery
+ * allowed.
+ *
+ * FIXME: Once cephfs allows us to reclaim earlier cephfs state in a
+ * new incarnation of the same client, we can allow recovery
+ * from "cur" instead of grace when ceph reclaim succeeds.
+ *
+ * BUT! We also need to fix stable client record creation. They
+ * are currently being created during EXCHANGE_ID, but that
+ * can lead to records being created for clients that hold no
+ * state. In some reboot + network partition situations we could
+ * end up allowing reclaim to some clients that should not.
+ *
+ * We need to fix the code to only set a client record for
+ * clients that have at least one file open (either via reclaim
+ * or new open). We should also remove the record when the
+ * client closes its last file.
+ *
+ * This would ensure that the recovery db only has records
+ * for clients that held state at the time of the crash.
+ */
+ if (rec == 0) {
+ LogEvent(COMPONENT_CLIENTID,
+ "Failed to join grace period: (rec == 0)");
+ return;
+ }
+
+ snprintf(rados_recov_old_oid, sizeof(rados_recov_old_oid),
+ "rec-%8.8x:%16.16lx", rados_kv_param.nodeid, rec);
+ ret = rados_kv_traverse(rados_kv_pop_clid_entry, &args,
+ rados_recov_old_oid);
+ if (ret < 0)
+ LogEvent(COMPONENT_CLIENTID,
+ "Failed to traverse recovery db: %d", ret);
+}
+
+/* FIXME */
+bool rados_cluster_try_lift_grace(void)
+{
+ int ret;
+ uint64_t cur, rec;
+
+ ret = rados_grace_done(rados_recov_io_ctx, RADOS_GRACE_OID,
+ rados_kv_param.nodeid, &cur, &rec);
+ if (ret) {
+ LogEvent(COMPONENT_CLIENTID,
+ "Attempt to lift grace failed: %d", ret);
+ return false;
+ }
+
+ /* Non-zero rec means grace is still in force */
+ return (rec == 0);
+}
+
+struct nfs4_recovery_backend rados_cluster_backend = {
+ .recovery_init = rados_cluster_init,
+ .recovery_read_clids = rados_cluster_read_clids,
+ .recovery_cleanup = rados_cluster_cleanup,
+ .add_clid = rados_kv_add_clid,
+ .rm_clid = rados_kv_rm_clid,
+ .add_revoke_fh = rados_kv_add_revoke_fh,
+ .try_lift_grace = rados_cluster_try_lift_grace,
+};
+
+void rados_cluster_backend_init(struct nfs4_recovery_backend **backend)
+{
+ *backend = &rados_cluster_backend;
+}
diff --git a/src/include/sal_functions.h b/src/include/sal_functions.h
index 259d911254a9..57dcc4509546 100644
--- a/src/include/sal_functions.h
+++ b/src/include/sal_functions.h
@@ -1022,6 +1022,7 @@ void fs_ng_backend_init(struct nfs4_recovery_backend **);
int rados_kv_set_param_from_conf(config_file_t, struct config_error_type *);
void rados_kv_backend_init(struct nfs4_recovery_backend **);
void rados_ng_backend_init(struct nfs4_recovery_backend **);
+void rados_cluster_backend_init(struct nfs4_recovery_backend **backend);
#endif
#endif /* SAL_FUNCTIONS_H */
--
2.14.3
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