[PATCH 06/27] libxl: cancellation: Preparations for save/restore cancellation

[Andrew Cooper <andrew.cooper3@citrix.com>]

From: Ian Jackson <ian.jackson@eu.citrix.com>

Two unrelated non-functional changes, broken out into a pre-patch for
easier review:

Break out a function sendsig() in libxl_save_callout.c.

Move io_fd to be a global variable in libxl_save_helper.c.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

Alter sendsig() to being libxl__kill() as it is needed in other translation
units.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/libxl_aoutils.c      |    7 +++++++
 tools/libxl/libxl_internal.h     |    2 ++
 tools/libxl/libxl_save_callout.c |    4 +---
 tools/libxl/libxl_save_helper.c  |    5 +++--
 4 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/tools/libxl/libxl_aoutils.c b/tools/libxl/libxl_aoutils.c
index ef679dd..bea0282 100644
--- a/tools/libxl/libxl_aoutils.c
+++ b/tools/libxl/libxl_aoutils.c
@@ -593,3 +593,10 @@ bool libxl__async_exec_inuse(const libxl__async_exec_state *aes)
     assert(time_inuse == child_inuse);
     return child_inuse;
 }
+
+void libxl__kill(libxl__gc *gc, pid_t pid, int sig, const char *what)
+{
+    int r = kill(pid, sig);
+    if (r) LOGE(WARN, "failed to kill() %s [%lu] (signal %d)",
+                what, (unsigned long)pid, sig);
+}
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index a4636ca..4f204f9 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -2161,6 +2161,8 @@ struct libxl__async_exec_state {
 int libxl__async_exec_start(libxl__gc *gc, libxl__async_exec_state *aes);
 bool libxl__async_exec_inuse(const libxl__async_exec_state *aes);
 
+void libxl__kill(libxl__gc *gc, pid_t pid, int sig, const char *what);
+
 /*----- device addition/removal -----*/
 
 typedef struct libxl__ao_device libxl__ao_device;
diff --git a/tools/libxl/libxl_save_callout.c b/tools/libxl/libxl_save_callout.c
index 3585a84..231de2f 100644
--- a/tools/libxl/libxl_save_callout.c
+++ b/tools/libxl/libxl_save_callout.c
@@ -253,9 +253,7 @@ static void helper_failed(libxl__egc *egc, libxl__save_helper_state *shs,
         return;
     }
 
-    int r = kill(shs->child.pid, SIGKILL);
-    if (r) LOGE(WARN, "failed to kill save/restore helper [%lu]",
-                (unsigned long)shs->child.pid);
+    libxl__kill(gc, shs->child.pid, SIGKILL, "save/restore helper");
 }
 
 static void helper_stdout_readable(libxl__egc *egc, libxl__ev_fd *ev,
diff --git a/tools/libxl/libxl_save_helper.c b/tools/libxl/libxl_save_helper.c
index 74826a1..7514b2e 100644
--- a/tools/libxl/libxl_save_helper.c
+++ b/tools/libxl/libxl_save_helper.c
@@ -85,6 +85,7 @@ static void tellparent_destroy(struct xentoollog_logger *logger_in)
     tellparent_destroy,
 };
 static xc_interface *xch;
+static int io_fd;
 
 /*----- error handling -----*/
 
@@ -211,7 +212,7 @@ int main(int argc, char **argv)
 
     if (!strcmp(mode,"--save-domain")) {
 
-        int io_fd =                atoi(NEXTARG);
+        io_fd =                    atoi(NEXTARG);
         uint32_t dom =             strtoul(NEXTARG,0,10);
         uint32_t max_iters =       strtoul(NEXTARG,0,10);
         uint32_t max_factor =      strtoul(NEXTARG,0,10);
@@ -234,7 +235,7 @@ int main(int argc, char **argv)
 
     } else if (!strcmp(mode,"--restore-domain")) {
 
-        int io_fd =                atoi(NEXTARG);
+        io_fd =                    atoi(NEXTARG);
         uint32_t dom =             strtoul(NEXTARG,0,10);
         unsigned store_evtchn =    strtoul(NEXTARG,0,10);
         domid_t store_domid =      strtoul(NEXTARG,0,10);
-- 
1.7.10.4