[v4,5/6] xenstore: make memory report available via XS_CONTROL

Commit Message

Jürgen Groß Feb. 24, 2017, 6:21 a.m. UTC

Add a XS_CONTROL command to xenstored for doing a talloc report to a
file. Right now this is supported by specifying a command line option
when starting xenstored and sending a signal to the daemon to trigger
the report.

To dump the report to the standard log file call:

xenstore-control memreport

To dump the report to a new file call:

xenstore-control memreport <file>

Signed-off-by: Juergen Gross <[e-mail]>
Reviewed-by: Wei Liu <[e-mail]>
---
 tools/xenstore/xenstored_control.c | 40 ++++++++++++++++++++++++++++++++++++++
 tools/xenstore/xenstored_core.c    |  2 +-
 tools/xenstore/xenstored_core.h    |  1 +
 3 files changed, 42 insertions(+), 1 deletion(-)

Patch

diff --git a/tools/xenstore/xenstored_control.c b/tools/xenstore/xenstored_control.c
index c3587ad..7c14911 100644
--- a/tools/xenstore/xenstored_control.c
+++ b/tools/xenstore/xenstored_control.c
@@ -76,6 +76,45 @@  static int do_control_logfile(void *ctx, struct connection *conn,
 	return 0;
 }
 
+static int do_control_memreport(void *ctx, struct connection *conn,
+				char **vec, int num)
+{
+	FILE *fp;
+	int fd;
+
+	if (num > 1)
+		return EINVAL;
+
+	if (num == 0) {
+		if (tracefd < 0) {
+			if (!tracefile)
+				return EBADF;
+			fp = fopen(tracefile, "a");
+		} else {
+			/*
+			 * Use dup() in order to avoid closing the file later
+			 * with fclose() which will release stream resources.
+			 */
+			fd = dup(tracefd);
+			if (fd < 0)
+				return EBADF;
+			fp = fdopen(fd, "a");
+			if (!fp)
+				close(fd);
+		}
+	} else
+		fp = fopen(vec[0], "a");
+
+	if (!fp)
+		return EBADF;
+
+	talloc_report_full(NULL, fp);
+	fclose(fp);
+
+	send_ack(conn, XS_CONTROL);
+	return 0;
+}
+
 static int do_control_print(void *ctx, struct connection *conn,
 			    char **vec, int num)
 {
@@ -94,6 +133,7 @@  static struct cmd_s cmds[] = {
 	{ "check", do_control_check, "" },
 	{ "log", do_control_log, "on|off" },
 	{ "logfile", do_control_logfile, "<file>" },
+	{ "memreport", do_control_memreport, "[<file>]" },
 	{ "print", do_control_print, "<string>" },
 	{ "help", do_control_help, "" },
 };
diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 1b79a48..b1f8fbc 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -76,7 +76,7 @@  static unsigned int nr_fds;
 
 static bool verbose = false;
 LIST_HEAD(connections);
-static int tracefd = -1;
+int tracefd = -1;
 static bool recovery = true;
 static int reopen_log_pipe[2];
 static int reopen_log_pipe0_pollfd_idx = -1;
diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
index d315568..92cccb6 100644
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -172,6 +172,7 @@  void reopen_log(void);
 void close_log(void);
 
 extern char *tracefile;
+extern int tracefd;
 extern int dom0_domid;
 extern int dom0_event;
 extern int priv_domid;