[PATCH v12 11/27] tools/xenstore: add command line handling for live update

[Juergen Gross <jgross@xxxxxxxx>]

Updating an instance of Xenstore via live update needs to hand over
the command line parameters to the updated instance. Those can be
either the parameters used by the updated instance or new ones when
supplied when starting the live update.

So when supplied store the new command line parameters in lu_status.

As it is related add a new option -U (or --live-update") to the command
line of xenstored which will be added when starting the new instance.
This enables to perform slightly different initializations when
started as a result of live update.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
Reviewed-by: Paul Durrant <paul@xxxxxxx>
---
 tools/xenstore/xenstored_control.c | 6 ++++++
 tools/xenstore/xenstored_core.c    | 7 ++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/tools/xenstore/xenstored_control.c 
b/tools/xenstore/xenstored_control.c
index 95ac1a1648..2e0827b9ef 100644
--- a/tools/xenstore/xenstored_control.c
+++ b/tools/xenstore/xenstored_control.c
@@ -42,6 +42,8 @@ struct live_update {
 #else
        char *filename;
 #endif
+
+       char *cmdline;
 };
 
 static struct live_update *lu_status;
@@ -211,6 +213,10 @@ static const char *lu_cmdline(const void *ctx, struct 
connection *conn,
        if (!lu_status || lu_status->conn != conn)
                return "Not in live-update session.";
 
+       lu_status->cmdline = talloc_strdup(lu_status, cmdline);
+       if (!lu_status->cmdline)
+               return "Allocation failure.";
+
        return NULL;
 }
 
diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index e1b92c3dc8..0dddf24327 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -1969,6 +1969,7 @@ static struct option options[] = {
        { "internal-db", 0, NULL, 'I' },
        { "verbose", 0, NULL, 'V' },
        { "watch-nb", 1, NULL, 'W' },
+       { "live-update", 0, NULL, 'U' },
        { NULL, 0, NULL, 0 } };
 
 extern void dump_conn(struct connection *conn); 
@@ -1983,11 +1984,12 @@ int main(int argc, char *argv[])
        bool dofork = true;
        bool outputpid = false;
        bool no_domain_init = false;
+       bool live_update = false;
        const char *pidfile = NULL;
        int timeout;
 
 
-       while ((opt = getopt_long(argc, argv, "DE:F:HNPS:t:A:M:T:RVW:", options,
+       while ((opt = getopt_long(argc, argv, "DE:F:HNPS:t:A:M:T:RVW:U", 
options,
                                  NULL)) != -1) {
                switch (opt) {
                case 'D':
@@ -2045,6 +2047,9 @@ int main(int argc, char *argv[])
                case 'p':
                        priv_domid = strtol(optarg, NULL, 10);
                        break;
+               case 'U':
+                       live_update = true;
+                       break;
                }
        }
        if (optind != argc)
-- 
2.26.2