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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 15/35] libxl: spawn: Preserve rc in error path
Make spawn provide an rc to its caller, and either pass it through
from the timeout callback, or invent ERROR_FAIL, as applicable.
Signed-off-by: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>
---
v4: New patch in this version of the series.
---
tools/libxl/libxl_dm.c | 8 +++++---
tools/libxl/libxl_exec.c | 36 ++++++++++++++++++++----------------
tools/libxl/libxl_internal.h | 5 +++--
3 files changed, 28 insertions(+), 21 deletions(-)
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index 33f9ce6..317a8eb 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -1370,7 +1370,8 @@ static void stubdom_xswait_cb(libxl__egc *egc,
libxl__xswait_state *xswait,
static void device_model_confirm(libxl__egc *egc, libxl__spawn_state *spawn,
const char *xsdata);
static void device_model_startup_failed(libxl__egc *egc,
- libxl__spawn_state *spawn);
+ libxl__spawn_state *spawn,
+ int rc);
static void device_model_detached(libxl__egc *egc,
libxl__spawn_state *spawn);
@@ -1540,10 +1541,11 @@ static void device_model_confirm(libxl__egc *egc,
libxl__spawn_state *spawn,
}
static void device_model_startup_failed(libxl__egc *egc,
- libxl__spawn_state *spawn)
+ libxl__spawn_state *spawn,
+ int rc)
{
libxl__dm_spawn_state *dmss = CONTAINER_OF(spawn, *dmss, spawn);
- device_model_spawn_outcome(egc, dmss, ERROR_FAIL);
+ device_model_spawn_outcome(egc, dmss, rc);
}
static void device_model_detached(libxl__egc *egc,
diff --git a/tools/libxl/libxl_exec.c b/tools/libxl/libxl_exec.c
index 478b4c2..85cbde0 100644
--- a/tools/libxl/libxl_exec.c
+++ b/tools/libxl/libxl_exec.c
@@ -238,11 +238,11 @@ err:
/*
* Full set of possible states of a libxl__spawn_state and its _detachable:
*
- * detaching failed mid timeout xswatch
+ * detaching rc mid timeout xswatch
* - Undefined undef undef - undef undef
* - Idle any any Idle Idle Idle
* - Attached OK 0 0 Active Active Active
- * - Attached Failed 0 1 Active Idle Idle
+ * - Attached Failed 0 non-0 Active Idle Idle
* - Detaching 1 maybe Active Idle Idle
* - Partial any any Idle Active/Idle Active/Idle
*
@@ -267,7 +267,7 @@ static void spawn_cleanup(libxl__gc *gc, libxl__spawn_state
*ss);
/* Precondition: Attached or Detaching; caller has logged failure reason.
* Results: Detaching, or Attached Failed */
-static void spawn_fail(libxl__egc *egc, libxl__spawn_state *ss);
+static void spawn_fail(libxl__egc *egc, libxl__spawn_state *ss, int rc);
void libxl__spawn_init(libxl__spawn_state *ss)
{
@@ -283,7 +283,7 @@ int libxl__spawn_spawn(libxl__egc *egc, libxl__spawn_state
*ss)
int status, rc;
libxl__spawn_init(ss);
- ss->failed = ss->detaching = 0;
+ ss->rc = ss->detaching = 0;
ss->xswait.ao = ao;
ss->xswait.what = GCSPRINTF("%s startup", ss->what);
@@ -352,12 +352,13 @@ static void spawn_cleanup(libxl__gc *gc,
libxl__spawn_state *ss)
static void spawn_detach(libxl__gc *gc, libxl__spawn_state *ss)
/* Precondition: Attached or Detaching, but caller must have just set
- * at least one of detaching or failed.
+ * at least one of detaching or rc.
* Results: Detaching or Attached Failed */
{
int r;
assert(libxl__ev_child_inuse(&ss->mid));
+ assert(ss->detaching || ss->rc);
libxl__xswait_stop(gc, &ss->xswait);
pid_t child = ss->mid.pid;
@@ -373,12 +374,13 @@ void libxl__spawn_initiate_detach(libxl__gc *gc,
libxl__spawn_state *ss)
spawn_detach(gc, ss);
}
-static void spawn_fail(libxl__egc *egc, libxl__spawn_state *ss)
+static void spawn_fail(libxl__egc *egc, libxl__spawn_state *ss, int rc)
/* Caller must have logged. Must be last thing in calling function,
* as it may make the callback. Precondition: Attached or Detaching. */
{
EGC_GC;
- ss->failed = 1;
+ assert(rc);
+ ss->rc = rc;
spawn_detach(gc, ss);
}
@@ -391,9 +393,10 @@ static void spawn_watch_event(libxl__egc *egc,
libxl__xswait_state *xswa,
if (rc) {
if (rc == ERROR_TIMEDOUT)
LOG(ERROR, "%s: startup timed out", ss->what);
- spawn_fail(egc, ss); /* must be last */
+ spawn_fail(egc, ss, rc); /* must be last */
return;
}
+ LOG(DEBUG, "%s: spawn watch p=%s", ss->what, p);
ss->confirm_cb(egc, ss, p); /* must be last */
}
@@ -404,7 +407,7 @@ static void spawn_middle_death(libxl__egc *egc,
libxl__ev_child *childw,
EGC_GC;
libxl__spawn_state *ss = CONTAINER_OF(childw, *ss, mid);
- if ((ss->failed || ss->detaching) &&
+ if ((ss->rc || ss->detaching) &&
((WIFEXITED(status) && WEXITSTATUS(status)==0) ||
(WIFSIGNALED(status) && WTERMSIG(status)==SIGKILL))) {
/* as expected */
@@ -413,7 +416,7 @@ static void spawn_middle_death(libxl__egc *egc,
libxl__ev_child *childw,
const char *what =
GCSPRINTF("%s intermediate process (startup monitor)", ss->what);
libxl_report_child_exitstatus(CTX, loglevel, what, pid, status);
- ss->failed = 1;
+ ss->rc = ERROR_FAIL;
} else {
if (!status)
LOG(ERROR, "%s [%ld]: unexpectedly exited with exit status 0,"
@@ -432,19 +435,20 @@ static void spawn_middle_death(libxl__egc *egc,
libxl__ev_child *childw,
LOG(ERROR, "%s [%ld]: died during startup due to unknown fatal"
" signal number %d", ss->what, (unsigned long)pid, sig);
}
- ss->failed = 1;
+ ss->rc = ERROR_FAIL;
}
spawn_cleanup(gc, ss);
- if (ss->failed && !ss->detaching) {
- ss->failure_cb(egc, ss); /* must be last */
+ if (ss->rc && !ss->detaching) {
+ ss->failure_cb(egc, ss, ss->rc); /* must be last */
return;
}
- if (ss->failed && ss->detaching)
- LOG(WARN,"%s underlying machinery seemed to fail,"
- " but its function seems to have been successful", ss->what);
+ if (ss->rc && ss->detaching)
+ LOG(WARN,"%s underlying machinery seemed to fail (%d),"
+ " but its function seems to have been successful",
+ ss->what, ss->rc);
assert(ss->detaching);
ss->detached_cb(egc, ss);
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index cda122e..8a142e7 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -1365,7 +1365,8 @@ libxl__spawn_midproc_cb(libxl__gc*, libxl__spawn_state*,
pid_t inner);
* The spawn state will be Idle on entry to the callback (and
* it may be reused immediately if desired).
*/
-typedef void libxl__spawn_failure_cb(libxl__egc*, libxl__spawn_state*);
+typedef void libxl__spawn_failure_cb(libxl__egc*, libxl__spawn_state*,
+ int rc);
/*
* Called when the xspath watch triggers. xspath will have been read
@@ -1406,7 +1407,7 @@ struct libxl__spawn_state {
/* remaining fields are private to libxl_spawn_... */
int detaching; /* we are in Detaching */
- int failed; /* might be true whenever we are not Idle */
+ int rc; /* might be non-0 whenever we are not Idle */
libxl__ev_child mid; /* always in use whenever we are not Idle */
libxl__xswait_state xswait;
};
--
1.7.10.4
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