From: Kevin Wolf <kwolf@redhat.com>
To: qemu-block@nongnu.org
Cc: kwolf@redhat.com, qemu-devel@nongnu.org
Subject: [Qemu-devel] [PULL 08/23] qemu-nbd: Add --fork option
Date: Mon, 24 Oct 2016 19:01:56 +0200 [thread overview]
Message-ID: <1477328531-30879-9-git-send-email-kwolf@redhat.com> (raw)
In-Reply-To: <1477328531-30879-1-git-send-email-kwolf@redhat.com>
From: Max Reitz <mreitz@redhat.com>
Using the --fork option, one can make qemu-nbd fork the worker process.
The original process will exit on error of the worker or once the worker
enters the main loop.
Suggested-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
qemu-nbd.c | 17 ++++++++++++++++-
qemu-nbd.texi | 2 ++
2 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/qemu-nbd.c b/qemu-nbd.c
index cca4a98..b757dc7 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -48,6 +48,7 @@
#define QEMU_NBD_OPT_OBJECT 260
#define QEMU_NBD_OPT_TLSCREDS 261
#define QEMU_NBD_OPT_IMAGE_OPTS 262
+#define QEMU_NBD_OPT_FORK 263
#define MBR_SIZE 512
@@ -92,6 +93,8 @@ static void usage(const char *name)
" passwords and/or encryption keys\n"
" -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
" specify tracing options\n"
+" --fork fork off the server process and exit the parent\n"
+" once the server is running\n"
#ifdef __linux__
"Kernel NBD client support:\n"
" -c, --connect=DEV connect FILE to the local NBD device DEV\n"
@@ -503,6 +506,7 @@ int main(int argc, char **argv)
{ "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
{ "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
{ "trace", required_argument, NULL, 'T' },
+ { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
{ NULL, 0, NULL, 0 }
};
int ch;
@@ -524,6 +528,8 @@ int main(int argc, char **argv)
bool imageOpts = false;
bool writethrough = true;
char *trace_file = NULL;
+ bool fork_process = false;
+ int old_stderr = -1;
/* The client thread uses SIGTERM to interrupt the server. A signal
* handler ensures that "qemu-nbd -v -c" exits with a nice status code.
@@ -715,6 +721,9 @@ int main(int argc, char **argv)
g_free(trace_file);
trace_file = trace_opt_parse(optarg);
break;
+ case QEMU_NBD_OPT_FORK:
+ fork_process = true;
+ break;
}
}
@@ -774,7 +783,7 @@ int main(int argc, char **argv)
return 0;
}
- if (device && !verbose) {
+ if ((device && !verbose) || fork_process) {
int stderr_fd[2];
pid_t pid;
int ret;
@@ -797,6 +806,7 @@ int main(int argc, char **argv)
ret = qemu_daemon(1, 0);
/* Temporarily redirect stderr to the parent's pipe... */
+ old_stderr = dup(STDERR_FILENO);
dup2(stderr_fd[1], STDERR_FILENO);
if (ret < 0) {
error_report("Failed to daemonize: %s", strerror(errno));
@@ -960,6 +970,11 @@ int main(int argc, char **argv)
exit(EXIT_FAILURE);
}
+ if (fork_process) {
+ dup2(old_stderr, STDERR_FILENO);
+ close(old_stderr);
+ }
+
state = RUNNING;
do {
main_loop_wait(false);
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 91ebf04..b7a9c6d 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -86,6 +86,8 @@ the new style NBD protocol negotiation
Enable mandatory TLS encryption for the server by setting the ID
of the TLS credentials object previously created with the --object
option.
+@item --fork
+Fork off the server process and exit the parent once the server is running.
@item -v, --verbose
Display extra debugging information
@item -h, --help
--
1.8.3.1
next prev parent reply other threads:[~2016-10-24 17:02 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-24 17:01 [Qemu-devel] [PULL 00/23] Block layer patches Kevin Wolf
2016-10-24 17:01 ` [Qemu-devel] [PULL 01/23] block: failed qemu-img command should return non-zero exit code Kevin Wolf
2016-10-24 17:01 ` [Qemu-devel] [PULL 02/23] qcow2: Support BDRV_REQ_MAY_UNMAP Kevin Wolf
2016-10-24 17:01 ` [Qemu-devel] [PULL 03/23] block: Remove "options" indirection from blockdev-add Kevin Wolf
2016-10-24 17:01 ` [Qemu-devel] [PULL 04/23] block: improve error handling in raw_open Kevin Wolf
2016-10-24 17:01 ` [Qemu-devel] [PULL 05/23] qapi: fix memory leak in bdrv_image_info_specific_dump Kevin Wolf
2016-10-24 17:01 ` [Qemu-devel] [PULL 06/23] throttle: Correct access to wrong BlockBackendPublic structures Kevin Wolf
2016-10-24 17:01 ` [Qemu-devel] [PULL 07/23] qemu-iotests: Test I/O in a single drive from a throttling group Kevin Wolf
2016-10-24 17:01 ` Kevin Wolf [this message]
2016-10-24 17:01 ` [Qemu-devel] [PULL 09/23] iotests: Remove raciness from 162 Kevin Wolf
2016-10-24 17:01 ` [Qemu-devel] [PULL 10/23] iotests: Do not rely on unavailable domains in 162 Kevin Wolf
2016-10-24 17:01 ` [Qemu-devel] [PULL 11/23] quorum: change child_iter to children_read Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 12/23] quorum: do not allocate multiple iovecs for FIFO strategy Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 13/23] block: Hide HBitmap in block dirty bitmap interface Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 14/23] HBitmap: Introduce "meta" bitmap to track bit changes Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 15/23] tests: Add test code for meta bitmap Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 16/23] block: Support meta dirty bitmap Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 17/23] block: Add two dirty bitmap getters Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 18/23] block: Assert that bdrv_release_dirty_bitmap succeeded Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 19/23] hbitmap: serialization Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 20/23] block: BdrvDirtyBitmap serialization interface Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 21/23] tests: Add test code for hbitmap serialization Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 22/23] block: More operations for meta dirty bitmap Kevin Wolf
2016-10-24 17:02 ` [Qemu-devel] [PULL 23/23] block/replication: Clarify 'top-id' parameter usage Kevin Wolf
2016-10-24 18:36 ` [Qemu-devel] [PULL 00/23] Block layer patches Peter Maydell
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