[Libguestfs] [PATCH 1/4] launch: appliance: Use socketpair instead of pipe for qemu stdin/stdout.
Richard W.M. Jones
rjones at redhat.com
Thu Mar 7 11:44:15 UTC 2013
From: "Richard W.M. Jones" <rjones at redhat.com>
The libvirt backend already uses a Unix socket for the appliance
console, and so for the libvirt backend the fields g->fd[0] == g->fd[1].
Change the appliance backend to use a socketpair, so we need just a
single file descriptor for qemu stdin/stdout (ie. appliance console).
Consequently we can remove the array int fd[2] in the handle and
replace it with a single file descriptor.
---
src/guestfs-internal.h | 2 +-
src/handle.c | 12 ++++--------
src/launch-appliance.c | 49 +++++++++++++++++++------------------------------
src/launch-libvirt.c | 18 ++++--------------
src/launch-unix.c | 7 +++----
src/proto.c | 36 +++++++++++++++++-------------------
6 files changed, 48 insertions(+), 76 deletions(-)
diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
index 793549f..4c632e8 100644
--- a/src/guestfs-internal.h
+++ b/src/guestfs-internal.h
@@ -263,7 +263,7 @@ struct guestfs_h
int unique;
/*** Protocol. ***/
- int fd[2]; /* Stdin/stdout of qemu. */
+ int fd; /* Stdin/stdout of qemu. */
int sock; /* Daemon communications socket. */
int msg_next_serial;
diff --git a/src/handle.c b/src/handle.c
index 0e66d1a..cefe385 100644
--- a/src/handle.c
+++ b/src/handle.c
@@ -91,8 +91,7 @@ guestfs_create_flags (unsigned flags, ...)
g->state = CONFIG;
- g->fd[0] = -1;
- g->fd[1] = -1;
+ g->fd = -1;
g->sock = -1;
guestfs___init_error_handler (g);
@@ -367,14 +366,11 @@ shutdown_backend (guestfs_h *g, int check_for_errors)
}
/* Close sockets. */
- if (g->fd[0] >= 0)
- close (g->fd[0]);
- if (g->fd[1] >= 0)
- close (g->fd[1]);
+ if (g->fd >= 0)
+ close (g->fd);
if (g->sock >= 0)
close (g->sock);
- g->fd[0] = -1;
- g->fd[1] = -1;
+ g->fd = -1;
g->sock = -1;
if (g->attach_ops->shutdown (g, check_for_errors) == -1)
diff --git a/src/launch-appliance.c b/src/launch-appliance.c
index a86a8cc..4016d61 100644
--- a/src/launch-appliance.c
+++ b/src/launch-appliance.c
@@ -167,7 +167,7 @@ static int
launch_appliance (guestfs_h *g, const char *arg)
{
int r;
- int wfd[2], rfd[2];
+ int sv[2];
char guestfsd_sock[256];
struct sockaddr_un addr;
CLEANUP_FREE char *kernel = NULL, *initrd = NULL, *appliance = NULL;
@@ -235,8 +235,8 @@ launch_appliance (guestfs_h *g, const char *arg)
}
if (!g->direct) {
- if (pipe (wfd) == -1 || pipe (rfd) == -1) {
- perrorf (g, "pipe");
+ if (socketpair (AF_LOCAL, SOCK_STREAM, 0, sv) == -1) {
+ perrorf (g, "socketpair");
goto cleanup0;
}
}
@@ -248,10 +248,8 @@ launch_appliance (guestfs_h *g, const char *arg)
if (r == -1) {
perrorf (g, "fork");
if (!g->direct) {
- close (wfd[0]);
- close (wfd[1]);
- close (rfd[0]);
- close (rfd[1]);
+ close (sv[0]);
+ close (sv[1]);
}
goto cleanup0;
}
@@ -484,17 +482,16 @@ launch_appliance (guestfs_h *g, const char *arg)
/* Set up stdin, stdout, stderr. */
close (0);
close (1);
- close (wfd[1]);
- close (rfd[0]);
+ close (sv[0]);
/* Stdin. */
- if (dup (wfd[0]) == -1) {
+ if (dup (sv[1]) == -1) {
dup_failed:
perror ("dup failed");
_exit (EXIT_FAILURE);
}
/* Stdout. */
- if (dup (rfd[1]) == -1)
+ if (dup (sv[1]) == -1)
goto dup_failed;
/* Particularly since qemu 0.15, qemu spews all sorts of debug
@@ -502,11 +499,10 @@ launch_appliance (guestfs_h *g, const char *arg)
* not confuse casual users, so send stderr to the pipe as well.
*/
close (2);
- if (dup (rfd[1]) == -1)
+ if (dup (sv[1]) == -1)
goto dup_failed;
- close (wfd[0]);
- close (rfd[1]);
+ close (sv[1]);
}
/* Dump the command line (after setting up stderr above). */
@@ -600,19 +596,16 @@ launch_appliance (guestfs_h *g, const char *arg)
}
if (!g->direct) {
- /* Close the other ends of the pipe. */
- close (wfd[0]);
- close (rfd[1]);
+ /* Close the other end of the socketpair. */
+ close (sv[1]);
- if (fcntl (wfd[1], F_SETFL, O_NONBLOCK) == -1 ||
- fcntl (rfd[0], F_SETFL, O_NONBLOCK) == -1) {
+ if (fcntl (sv[0], F_SETFL, O_NONBLOCK) == -1) {
perrorf (g, "fcntl");
goto cleanup1;
}
- g->fd[0] = wfd[1]; /* stdin of child */
- g->fd[1] = rfd[0]; /* stdout of child */
- wfd[1] = rfd[0] = -1;
+ g->fd = sv[0]; /* stdin of child */
+ sv[0] = -1;
}
g->state = LAUNCHING;
@@ -680,18 +673,14 @@ launch_appliance (guestfs_h *g, const char *arg)
return 0;
cleanup1:
- if (!g->direct) {
- if (wfd[1] >= 0) close (wfd[1]);
- if (rfd[1] >= 0) close (rfd[0]);
- }
+ if (!g->direct && sv[0] >= 0)
+ close (sv[0]);
if (g->app.pid > 0) kill (g->app.pid, 9);
if (g->app.recoverypid > 0) kill (g->app.recoverypid, 9);
if (g->app.pid > 0) waitpid (g->app.pid, NULL, 0);
if (g->app.recoverypid > 0) waitpid (g->app.recoverypid, NULL, 0);
- if (g->fd[0] >= 0) close (g->fd[0]);
- if (g->fd[1] >= 0) close (g->fd[1]);
- g->fd[0] = -1;
- g->fd[1] = -1;
+ if (g->fd >= 0) close (g->fd);
+ g->fd = -1;
g->app.pid = 0;
g->app.recoverypid = 0;
memset (&g->launch_t, 0, sizeof g->launch_t);
diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c
index 5a69ced..caad5d4 100644
--- a/src/launch-libvirt.c
+++ b/src/launch-libvirt.c
@@ -399,13 +399,7 @@ launch_libvirt (guestfs_h *g, const char *libvirt_uri)
goto cleanup;
}
console = -1;
- g->fd[0] = r; /* This is the accepted console socket. */
-
- g->fd[1] = dup (g->fd[0]);
- if (g->fd[1] == -1) {
- perrorf (g, "dup");
- goto cleanup;
- }
+ g->fd = r; /* This is the accepted console socket. */
/* Wait for libvirt domain to start and to connect back to us via
* virtio-serial and send the GUESTFS_LAUNCH_FLAG message.
@@ -481,13 +475,9 @@ launch_libvirt (guestfs_h *g, const char *libvirt_uri)
if (console >= 0)
close (console);
- if (g->fd[0] >= 0) {
- close (g->fd[0]);
- g->fd[0] = -1;
- }
- if (g->fd[1] >= 0) {
- close (g->fd[1]);
- g->fd[1] = -1;
+ if (g->fd >= 0) {
+ close (g->fd);
+ g->fd = -1;
}
if (g->sock >= 0) {
close (g->sock);
diff --git a/src/launch-unix.c b/src/launch-unix.c
index 9bd64fa..a7a3ae2 100644
--- a/src/launch-unix.c
+++ b/src/launch-unix.c
@@ -46,11 +46,10 @@ launch_unix (guestfs_h *g, const char *sockpath)
return -1;
}
- /* Set these to nothing so we don't try to read from random file
- * descriptors.
+ /* Set this to nothing so we don't try to read from a random file
+ * descriptor.
*/
- g->fd[0] = -1;
- g->fd[1] = -1;
+ g->fd = -1;
if (g->verbose)
guestfs___print_timestamped_message (g, "connecting to %s", sockpath);
diff --git a/src/proto.c b/src/proto.c
index 3d00b2b..57cb609 100644
--- a/src/proto.c
+++ b/src/proto.c
@@ -161,11 +161,9 @@ child_cleanup (guestfs_h *g)
debug (g, "child_cleanup: %p: child process died", g);
g->attach_ops->shutdown (g, 0);
- if (g->fd[0] >= 0) close (g->fd[0]);
- if (g->fd[1] >= 0) close (g->fd[1]);
+ if (g->fd >= 0) close (g->fd);
close (g->sock);
- g->fd[0] = -1;
- g->fd[1] = -1;
+ g->fd = -1;
g->sock = -1;
memset (&g->launch_t, 0, sizeof g->launch_t);
guestfs___free_drives (g);
@@ -385,12 +383,12 @@ send_to_daemon (guestfs_h *g, const void *v_buf, size_t n)
FD_ZERO (&rset);
FD_ZERO (&wset);
- if (g->fd[1] >= 0) /* Read qemu stdout for log messages & EOF. */
- FD_SET (g->fd[1], &rset);
+ if (g->fd >= 0) /* Read qemu stdout for log messages & EOF. */
+ FD_SET (g->fd, &rset);
FD_SET (g->sock, &rset); /* Read socket for cancellation & EOF. */
FD_SET (g->sock, &wset); /* Write to socket to send the data. */
- int max_fd = MAX (g->sock, g->fd[1]);
+ int max_fd = MAX (g->sock, g->fd);
while (n > 0) {
rset2 = rset;
@@ -403,8 +401,8 @@ send_to_daemon (guestfs_h *g, const void *v_buf, size_t n)
return -1;
}
- if (g->fd[1] >= 0 && FD_ISSET (g->fd[1], &rset2)) {
- if (read_log_message_or_eof (g, g->fd[1], 0) == -1)
+ if (g->fd >= 0 && FD_ISSET (g->fd, &rset2)) {
+ if (read_log_message_or_eof (g, g->fd, 0) == -1)
return -1;
}
if (FD_ISSET (g->sock, &rset2)) {
@@ -516,11 +514,11 @@ recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn)
FD_ZERO (&rset);
- if (g->fd[1] >= 0) /* Read qemu stdout for log messages & EOF. */
- FD_SET (g->fd[1], &rset);
+ if (g->fd >= 0) /* Read qemu stdout for log messages & EOF. */
+ FD_SET (g->fd, &rset);
FD_SET (g->sock, &rset); /* Read socket for data & EOF. */
- max_fd = MAX (g->sock, g->fd[1]);
+ max_fd = MAX (g->sock, g->fd);
*size_rtn = 0;
*buf_rtn = NULL;
@@ -548,8 +546,8 @@ recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn)
return -1;
}
- if (g->fd[1] >= 0 && FD_ISSET (g->fd[1], &rset2)) {
- if (read_log_message_or_eof (g, g->fd[1], 0) == -1) {
+ if (g->fd >= 0 && FD_ISSET (g->fd, &rset2)) {
+ if (read_log_message_or_eof (g, g->fd, 0) == -1) {
free (*buf_rtn);
*buf_rtn = NULL;
return -1;
@@ -728,11 +726,11 @@ guestfs___accept_from_daemon (guestfs_h *g)
FD_ZERO (&rset);
- if (g->fd[1] >= 0) /* Read qemu stdout for log messages & EOF. */
- FD_SET (g->fd[1], &rset);
+ if (g->fd >= 0) /* Read qemu stdout for log messages & EOF. */
+ FD_SET (g->fd, &rset);
FD_SET (g->sock, &rset); /* Read socket for accept. */
- int max_fd = MAX (g->sock, g->fd[1]);
+ int max_fd = MAX (g->sock, g->fd);
int sock = -1;
while (sock == -1) {
@@ -760,8 +758,8 @@ guestfs___accept_from_daemon (guestfs_h *g)
return -1;
}
- if (g->fd[1] >= 0 && FD_ISSET (g->fd[1], &rset2)) {
- if (read_log_message_or_eof (g, g->fd[1], 1) == -1)
+ if (g->fd >= 0 && FD_ISSET (g->fd, &rset2)) {
+ if (read_log_message_or_eof (g, g->fd, 1) == -1)
return -1;
}
if (FD_ISSET (g->sock, &rset2)) {
--
1.8.1.4
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