[Libguestfs] [PATCH libnbd] api: New nbd_kill_command API for sending a signal to the command subprocess.
Eric Blake
eblake at redhat.com
Fri Jul 26 01:08:26 UTC 2019
On 7/25/19 3:19 PM, Eric Blake wrote:
> On 7/25/19 2:15 PM, Richard W.M. Jones wrote:
>> Reverts commit 387cbe67c3db27e8a61117fedb6e7fad76e409ef.
>> ---
>> generator/generator | 18 +++++++++++++++++-
>> lib/handle.c | 28 +++++++++++++++++++++++++++-
>> tests/closure-lifetimes.c | 4 +++-
>> 3 files changed, 47 insertions(+), 3 deletions(-)
>
> tests/server-death.c can be simplified (no longer has to use --pidfile
> to learn where to send its kill); could be done on top.
Done now:
From a9c42e136ef52361a13a7a2f2e7eae6cadb36421 Mon Sep 17 00:00:00 2001
From: Eric Blake <eblake at redhat.com>
Date: Thu, 25 Jul 2019 19:58:32 -0500
Subject: [libnbd PATCH] tests: Simplify server-death with nbd_kill_command
Now that libnbd can forward our kill request, we don't need to manage
a pidfile ourselves. And we don't even have to ignore SIGCHLD to
avoid waiting for a zombie; all we really need is our existing
nbd_aio_poll loop to detect that the connection dies.
---
tests/server-death.c | 100 ++++++++++++++-----------------------------
1 file changed, 31 insertions(+), 69 deletions(-)
diff --git a/tests/server-death.c b/tests/server-death.c
index cd58190..56e7e51 100644
--- a/tests/server-death.c
+++ b/tests/server-death.c
@@ -25,7 +25,6 @@
#include <stdlib.h>
#include <string.h>
#include <errno.h>
-#include <unistd.h>
#include <signal.h>
#include <libnbd.h>
@@ -56,69 +55,46 @@ main (int argc, char *argv[])
const char *msg;
char buf[512];
int64_t cookie;
- char pidfile[] = "/tmp/libnbd-test-disconnectXXXXXX";
- int fd;
- pid_t pid;
int r;
- int delay = 0;
- const char *cmd[] = { "nbdkit", "--pidfile", pidfile, "-s",
- "--exit-with-parent", "--filter=delay", "memory",
- "size=1m", "delay-read=15", "delay-trim=15",
NULL };
+ const char *cmd[] = { "nbdkit", "-s", "--exit-with-parent",
+ "--filter=delay", "memory", "size=1m",
+ "delay-read=15", "delay-trim=15", NULL };
progname = argv[0];
- /* We're going to kill the child, but don't want to wait for a zombie */
- if (signal (SIGCHLD, SIG_IGN) == SIG_ERR) {
- fprintf (stderr, "%s: signal: %s\n", argv[0], strerror (errno));
- exit (EXIT_FAILURE);
- }
-
- fd = mkstemp (pidfile);
- if (fd < 0) {
- fprintf (stderr, "%s: mkstemp: %s\n", argv[0], strerror (errno));
- exit (EXIT_FAILURE);
- }
-
nbd = nbd_create ();
if (nbd == NULL) {
fprintf (stderr, "%s: %s\n", argv[0], nbd_get_error ());
- goto fail;
+ exit (EXIT_FAILURE);
}
/* Connect to a slow server. */
if (nbd_connect_command (nbd, (char **) cmd) == -1) {
fprintf (stderr, "%s: %s\n", argv[0], nbd_get_error ());
- goto fail;
- }
- if (read (fd, buf, sizeof buf) == -1) {
- fprintf (stderr, "%s: read: %s\n", argv[0], strerror (errno));
- goto fail;
- }
- pid = atoi (buf);
- if (pid <= 0) {
- fprintf (stderr, "%s: unable to parse server's pid\n", argv[0]);
- goto fail;
+ exit (EXIT_FAILURE);
}
/* Issue a read and trim that should not complete yet. Set up the
* trim to auto-retire via callback.
*/
if ((cookie = nbd_aio_pread (nbd, buf, sizeof buf, 0, 0)) == -1) {
- fprintf (stderr, "%s: test failed: nbd_aio_pread\n", argv[0]);
- goto fail;
+ fprintf (stderr, "%s: test failed: nbd_aio_pread: %s\n", argv[0],
+ nbd_get_error ());
+ exit (EXIT_FAILURE);
}
if (nbd_aio_trim_callback (nbd, sizeof buf, 0, callback, NULL, 0) ==
-1) {
- fprintf (stderr, "%s: test failed: nbd_aio_trim_callback\n", argv[0]);
- goto fail;
+ fprintf (stderr, "%s: test failed: nbd_aio_trim_callback: %s\n",
argv[0],
+ nbd_get_error ());
+ exit (EXIT_FAILURE);
}
if (nbd_aio_peek_command_completed (nbd) != 0) {
fprintf (stderr, "%s: test failed: nbd_aio_peek_command_completed\n",
argv[0]);
- goto fail;
+ exit (EXIT_FAILURE);
}
if (nbd_aio_command_completed (nbd, cookie) != 0) {
fprintf (stderr, "%s: test failed: nbd_aio_command_completed\n",
argv[0]);
- goto fail;
+ exit (EXIT_FAILURE);
}
/* Kill the server forcefully (SIGINT is not always strong enough,
@@ -126,47 +102,39 @@ main (int argc, char *argv[])
* actually exiting), although it's a race whether our signal
* arrives while nbdkit has a pending transaction.
*/
- if (kill (pid, SIGKILL) == -1) {
- fprintf (stderr, "%s: kill: %s\n", argv[0], strerror (errno));
- goto fail;
- }
- /* Wait up to 10 seconds, 100 ms at a time */
- while (kill (pid, 0) == 0) {
- if (delay++ > 100) {
- fprintf (stderr, "%s: kill taking too long\n", argv[0]);
- goto fail;
- }
- usleep (100 * 1000);
+ if (nbd_kill_command (nbd, SIGKILL) == -1) {
+ fprintf (stderr, "%s: test failed: nbd_kill_command: %s\n", argv[0],
+ nbd_get_error ());
+ exit (EXIT_FAILURE);
}
- /* This part is somewhat racy if we don't wait for the process death
- * above - depending on load and timing, nbd_poll may succeed or
- * fail, and we may transition to either CLOSED (the state machine
- * saw a clean EOF) or DEAD (the state machine saw a stranded
- * transaction or POLLERR).
+ /* This part is somewhat racy depending on how fast we run before
+ * the server process exits - depending on load and timing, nbd_poll
+ * may succeed or fail, and we may transition to either CLOSED (the
+ * state machine saw a clean EOF) or DEAD (the state machine saw a
+ * stranded transaction or POLLERR).
*/
while ((r = nbd_poll (nbd, 1000)) == 1)
if (nbd_aio_is_dead (nbd) || nbd_aio_is_closed (nbd))
break;
if (!(nbd_aio_is_dead (nbd) || nbd_aio_is_closed (nbd))) {
fprintf (stderr, "%s: test failed: server death not detected\n",
argv[0]);
- goto fail;
+ exit (EXIT_FAILURE);
}
/* Detection of the dead server completes all remaining in-flight
commands */
if (nbd_aio_in_flight (nbd) != 0) {
- fprintf (stderr, "%s: test failed: nbd_aio_in_flight\n",
- argv[0]);
- goto fail;
+ fprintf (stderr, "%s: test failed: nbd_aio_in_flight\n", argv[0]);
+ exit (EXIT_FAILURE);
}
if (nbd_aio_peek_command_completed (nbd) != cookie) {
fprintf (stderr, "%s: test failed: nbd_aio_peek_command_completed\n",
argv[0]);
- goto fail;
+ exit (EXIT_FAILURE);
}
if (nbd_aio_command_completed (nbd, cookie) != -1) {
fprintf (stderr, "%s: test failed: nbd_aio_command_completed\n",
argv[0]);
- goto fail;
+ exit (EXIT_FAILURE);
}
msg = nbd_get_error ();
err = nbd_get_errno ();
@@ -175,19 +143,19 @@ main (int argc, char *argv[])
if (err != ENOTCONN) {
fprintf (stderr, "%s: test failed: unexpected errno %d (%s)\n",
argv[0],
err, strerror (err));
- goto fail;
+ exit (EXIT_FAILURE);
}
/* With all commands retired, no further command should be pending */
if (!trim_retired) {
fprintf (stderr, "%s: test failed: nbd_aio_trim_callback not
retired\n",
argv[0]);
- goto fail;
+ exit (EXIT_FAILURE);
}
if (nbd_aio_peek_command_completed (nbd) != -1) {
fprintf (stderr, "%s: test failed: nbd_aio_peek_command_completed\n",
argv[0]);
- goto fail;
+ exit (EXIT_FAILURE);
}
msg = nbd_get_error ();
err = nbd_get_errno ();
@@ -196,15 +164,9 @@ main (int argc, char *argv[])
if (err != EINVAL) {
fprintf (stderr, "%s: test failed: unexpected errno %d (%s)\n",
argv[0],
err, strerror (err));
- goto fail;
+ exit (EXIT_FAILURE);
}
- close (fd);
- unlink (pidfile);
nbd_close (nbd);
exit (EXIT_SUCCESS);
-
- fail:
- unlink (pidfile);
- exit (EXIT_FAILURE);
}
--
2.20.1
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libguestfs/attachments/20190725/1a4c2afa/attachment.sig>
More information about the Libguestfs
mailing list