Hello,
We have a setup, where we are using the iSCSI redirect functionality, where
we connect to a highly available persistent address, and get redirected to
a different address/portal.
Our setup allows modifying the persistent IP address of the iSCSI targets,
amongst active I/O to the iSCSI sessions to the redirected
addresses/portals.
The requirement is to ensure non-disruptive I/O when any portal crashes.
(persistent address/portal is assumed to be still available)
Consider a scenario where sessions are redirected to different
addresses/portals and now the persistent portal address is modified on the
target.
Without this patch:
When the redirected portal crashes, iscsid would tries to recover the
session by reconnecting to the incorrect/stale in-memory 'failback_saddr'
portal.
Since, this IP is modified on the fly, iscsid tries reconnecting to a wrong
portal.
With the patch:
Patch notifiies iscsid about the change in the persistent address of all
the sessions via the iscsiadm utility.
All in-memory session structures' failback addresses are updated with the
new persistent address.
We have unit-tested the patch in our setup and we can see sessions
recovering amongst current portal failures.
Usage:
iscsiadm -m session -n updated_persistent_ip_address -v 192.168.5.5
Would be great if someone can review the attached patch. Any
feedback/suggestions/questions greatly appreciated.
Thanks,
Satyajit
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commit dcee6c1e4b9f98472f814a69632a42a98bb71559
Author: Satyajit Deshmukh <satyajit.s.deshm...@gmail.com>
Date: Wed Feb 8 01:19:06 2017 -0800
iscsiadm utility to update persistent address of all sessions, to a given address. Usage: iscsiadm -m session -n updated_persistent_ip_address -v 192.168.5.5
diff --git a/usr/initiator.h b/usr/initiator.h
index 4f96d6b..49ce189 100644
--- a/usr/initiator.h
+++ b/usr/initiator.h
@@ -281,7 +281,7 @@ extern int iscsi_add_text(struct iscsi_hdr *hdr, char *data, int max_data_length
extern enum iscsi_login_status iscsi_login(iscsi_session_t *session, int cid,
char *buffer, size_t bufsize, uint8_t * status_class,
uint8_t * status_detail);
-extern int iscsi_update_address(iscsi_conn_t *conn, char *address);
+extern int iscsi_update_address(iscsi_conn_t *conn, char *address, int update_persistent_address);
extern int iscsi_login_begin(iscsi_session_t *session,
iscsi_login_context_t *c);
extern int iscsi_login_req(iscsi_session_t *session, iscsi_login_context_t *c);
diff --git a/usr/iscsiadm.c b/usr/iscsiadm.c
index 4b2bd34..c66790b 100644
--- a/usr/iscsiadm.c
+++ b/usr/iscsiadm.c
@@ -3713,6 +3713,14 @@ free_info:
}
rc = session_info_print(info_level, NULL, do_show);
+
+ /* Update persistent portal if old and new ip portal is provided. */
+ list_for_each_entry(param, ¶ms, list) {
+ if (!strcmp("updated_persistent_ip_address", param->name)) {
+ update_persistent_ip_address(param->value);
+ break;
+ }
+ }
}
break;
default:
diff --git a/usr/login.c b/usr/login.c
index 294ad0b..e605827 100644
--- a/usr/login.c
+++ b/usr/login.c
@@ -184,7 +184,7 @@ resolve_address(char *host, char *port, struct sockaddr_storage *ss)
* provided
*/
int
-iscsi_update_address(iscsi_conn_t *conn, char *address)
+iscsi_update_address(iscsi_conn_t *conn, char *address, int update_persistent_address)
{
char *port, *tag;
char default_port[NI_MAXSERV];
@@ -222,7 +222,11 @@ iscsi_update_address(iscsi_conn_t *conn, char *address)
return 0;
}
- conn->saddr = addr;
+ if (!update_persistent_address)
+ conn->saddr = addr;
+ else
+ conn->failback_saddr = addr;
+
if (tag)
session->portal_group_tag = atoi(tag);
return 1;
@@ -265,7 +269,7 @@ get_security_text_keys(iscsi_session_t *session, int cid, char **data,
* ip_address and port to the new TargetAddress for
* leading connection
*/
- if (iscsi_update_address(&session->conn[cid], value)) {
+ if (iscsi_update_address(&session->conn[cid], value, 0)) {
text = value_end;
} else {
log_error("Login redirection failed, "
@@ -337,7 +341,7 @@ get_op_params_text_keys(iscsi_session_t *session, int cid,
text = value_end;
} else if (iscsi_find_key_value("TargetAddress", text, end, &value,
&value_end)) {
- if (iscsi_update_address(conn, value))
+ if (iscsi_update_address(conn, value, 0))
text = value_end;
else {
log_error("Login redirection failed, "
diff --git a/usr/mgmt_ipc.c b/usr/mgmt_ipc.c
index c16bce9..9e4d3d9 100644
--- a/usr/mgmt_ipc.c
+++ b/usr/mgmt_ipc.c
@@ -37,6 +37,8 @@
#include "iscsi_ipc.h"
#include "iscsi_err.h"
#include "iscsi_util.h"
+#include "session_info.h"
+#include "initiator.h"
#define PEERUSER_MAX 64
#define EXTMSG_MAX (64 * 1024)
@@ -346,6 +348,35 @@ mgmt_ipc_notify_del_portal(queue_task_t *qtask)
return mgmt_ipc_notify_common(qtask, iscsi_discovery_del_portal);
}
+static int update_persistent_address(void *data, struct session_info *info)
+{
+ int rc, sid = info->sid;
+ char *persistent_address = (char *)data;
+ struct iscsi_session *session = session_find_by_sid(sid);
+ if (iscsi_update_address(&session->conn[0], persistent_address, 1)) {
+ log_info("Successfully updated persistent address to %s for session %d", persistent_address, sid);
+ rc = 0;
+ } else {
+ log_error("Failed to update persistent address to %s for session %d", persistent_address, sid);
+ rc = -1;
+ }
+ return rc;
+}
+
+static int
+mgmt_ipc_notify_upd_perst_addr(queue_task_t *qtask)
+{
+ char *persistent_ip_address = qtask->req.u.updated_persistent_ip_address;
+ int nr_found = 0, err;
+ err = iscsi_sysfs_for_each_session(persistent_ip_address, &nr_found, update_persistent_address, 0);
+
+ if (!err)
+ log_info("Successfully updated persistent portals for %d sessions.", nr_found);
+
+ mgmt_ipc_write_rsp(qtask, err);
+ return ISCSI_SUCCESS;
+}
+
static int
mgmt_peeruser(int sock, char *user)
{
@@ -530,6 +561,7 @@ static mgmt_ipc_fn_t * mgmt_ipc_functions[__MGMT_IPC_MAX_COMMAND] = {
[MGMT_IPC_NOTIFY_DEL_NODE] = mgmt_ipc_notify_del_node,
[MGMT_IPC_NOTIFY_ADD_PORTAL] = mgmt_ipc_notify_add_portal,
[MGMT_IPC_NOTIFY_DEL_PORTAL] = mgmt_ipc_notify_del_portal,
+[MGMT_IPC_NOTIFY_UPD_PERST_ADDR] = mgmt_ipc_notify_upd_perst_addr,
};
void mgmt_ipc_handle(int accept_fd)
diff --git a/usr/mgmt_ipc.h b/usr/mgmt_ipc.h
index 55972ed..d0b18b6 100644
--- a/usr/mgmt_ipc.h
+++ b/usr/mgmt_ipc.h
@@ -46,6 +46,7 @@ typedef enum iscsiadm_cmd {
MGMT_IPC_NOTIFY_DEL_NODE = 17,
MGMT_IPC_NOTIFY_ADD_PORTAL = 18,
MGMT_IPC_NOTIFY_DEL_PORTAL = 19,
+ MGMT_IPC_NOTIFY_UPD_PERST_ADDR = 20,
__MGMT_IPC_MAX_COMMAND
} iscsiadm_cmd_e;
@@ -77,6 +78,7 @@ typedef struct iscsiadm_req {
char value[IFNAMSIZ + 1];
} set_host_param;
+ char updated_persistent_ip_address[NI_MAXHOST];
} u;
} iscsiadm_req_t;
diff --git a/usr/session_info.c b/usr/session_info.c
index 9dc6e25..f17d674 100644
--- a/usr/session_info.c
+++ b/usr/session_info.c
@@ -146,6 +146,23 @@ static int print_iscsi_state(int sid, char *prefix, int tmo)
return 0;
}
+void update_persistent_ip_address(char *persistent_ip_address)
+{
+ iscsiadm_req_t req;
+ iscsiadm_rsp_t rsp;
+ int err;
+
+ memset(&req, 0, sizeof(iscsiadm_req_t));
+ req.command = MGMT_IPC_NOTIFY_UPD_PERST_ADDR;
+ strcpy(req.u.updated_persistent_ip_address, persistent_ip_address);
+
+ err = iscsid_exec_req(&req, &rsp, 1, ISCSID_REQ_TIMEOUT);
+ if (!err)
+ printf("Updated all sessions' persistent IP address to %s\n", persistent_ip_address);
+ else
+ printf("Failed with %d to update sessions with newer persistent portal address.\n", err);
+}
+
static void print_iscsi_params(int sid, char *prefix)
{
struct iscsi_session_operational_config session_conf;
