Signed-off-by: Charles Duffy <address@hidden>
From c48ba672cd92d1d173fe9cb93f8e268d0d7952bc Mon Sep 17 00:00:00 2001
From: Charles Duffy <address@hidden>
Date: Fri, 28 Aug 2009 22:17:47 -0500
Subject: [PATCH 1/2] stop using popen for outgoing migrations
---
migration-exec.c | 95 +++++++++++++++++++++++++++++++++++
+-----------------
qemu-common.h | 2 +
2 files changed, 66 insertions(+), 31 deletions(-)
diff --git a/migration-exec.c b/migration-exec.c
index b45c833..c36e756 100644
--- a/migration-exec.c
+++ b/migration-exec.c
@@ -31,25 +31,72 @@
do { } while (0)
#endif
-static int file_errno(FdMigrationState *s)
+// opaque is pid
+typedef struct ExecMigrationState
+{
+ pid_t pid;
+} ExecMigrationState;
+
+static int exec_errno(FdMigrationState *s)
{
return errno;
}
-static int file_write(FdMigrationState *s, const void * buf, size_t
size)
+static int exec_write(FdMigrationState *s, const void * buf, size_t
size)
{
return write(s->fd, buf, size);
}
static int exec_close(FdMigrationState *s)
{
+ int ret, status;
+
dprintf("exec_close\n");
- if (s->opaque) {
- qemu_fclose(s->opaque);
- s->opaque = NULL;
- s->fd = -1;
+
+ close(s->fd);
+
+ if (!(s->opaque))
+ return -1;
+
+ do {
+ ret = waitpid(((ExecMigrationState*)(s->opaque))->pid,
&status, 0);
+ } while (ret == -1 && errno == EINTR);
+
+ qemu_free(s->opaque);
+ s->opaque = 0;
+
+ return status;
+}
+
+static pid_t exec_start_migration(const char *command, int *fd) {
+ const char *argv[] = { "sh", "-c", command, NULL };
+ int fds[2];
+ pid_t pid;
+
+ if (pipe(fds) == -1) {
+ dprintf("pipe() (%s)\n", strerr(errno));
+ return 0;
}
- return 0;
+
+ pid = fork();
+ if(pid == -1) {
+ close(fds[0]);
+ close(fds[1]);
+ dprintf("fork error (%s)\n", strerror(errno));
+ return 0;
+ } else if (pid == 0) {
+ /* child process */
+ close(fds[1]);
+ dup2(fds[0], STDIN_FILENO);
+ execv("/bin/sh", (char **)argv);
+ exit(1);
+ }
+ close(fds[0]);
+
+ fcntl(fds[1], O_NONBLOCK);
+
+ *fd = fds[1];
+ return pid;
}
MigrationState *exec_start_outgoing_migration(const char *command,
@@ -57,29 +104,20 @@ MigrationState
*exec_start_outgoing_migration(const char *command,
int detach)
{
FdMigrationState *s;
- FILE *f;
+ int fd, pid;
- s = qemu_mallocz(sizeof(*s));
+ pid = exec_start_migration(command, &fd);
+ if(!pid) return NULL;
- f = popen(command, "w");
- if (f == NULL) {
- dprintf("Unable to popen exec target\n");
- goto err_after_alloc;
- }
-
- s->fd = fileno(f);
- if (s->fd == -1) {
- dprintf("Unable to retrieve file descriptor for popen'd
handle\n");
- goto err_after_open;
- }
-
- socket_set_nonblock(s->fd);
+ s = qemu_mallocz(sizeof(*s));
+ s->opaque = qemu_mallocz(sizeof(ExecMigrationState));
- s->opaque = qemu_popen(f, "w");
+ ((ExecMigrationState*)(s->opaque))->pid = pid;
+ s->fd = fd;
+ s->get_error = exec_errno;
+ s->write = exec_write;
s->close = exec_close;
- s->get_error = file_errno;
- s->write = file_write;
s->mig_state.cancel = migrate_fd_cancel;
s->mig_state.get_status = migrate_fd_get_status;
s->mig_state.release = migrate_fd_release;
@@ -93,14 +131,9 @@ MigrationState
*exec_start_outgoing_migration(const char *command,
migrate_fd_connect(s);
return &s->mig_state;
-
-err_after_open:
- pclose(f);
-err_after_alloc:
- qemu_free(s);
- return NULL;
}
+/* helper for incoming case */
static void exec_accept_incoming_migration(void *opaque)
{
QEMUFile *f = opaque;
diff --git a/qemu-common.h b/qemu-common.h
index c8fb315..aeb1d78 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -24,6 +24,8 @@
#include <fcntl.h>
#include <sys/stat.h>
#include <assert.h>
+#include <sys/types.h>
+#include <sys/wait.h>
#include "config-host.h"
#ifndef O_LARGEFILE
--
1.6.4
From e7066ce85e969e43c8142f4845bc843e9d53f5e4 Mon Sep 17 00:00:00 2001
From: Charles Duffy <address@hidden>
Date: Fri, 28 Aug 2009 23:18:49 -0500
Subject: [PATCH 2/2] stop using popen for incoming migrations
---
migration-exec.c | 51 ++++++++++++++++++++++++++++++
+--------------------
1 files changed, 31 insertions(+), 20 deletions(-)
diff --git a/migration-exec.c b/migration-exec.c
index c36e756..3dfea18 100644
--- a/migration-exec.c
+++ b/migration-exec.c
@@ -31,10 +31,10 @@
do { } while (0)
#endif
-// opaque is pid
typedef struct ExecMigrationState
{
pid_t pid;
+ int fd; /* only used for incoming */
} ExecMigrationState;
static int exec_errno(FdMigrationState *s)
@@ -68,9 +68,9 @@ static int exec_close(FdMigrationState *s)
return status;
}
-static pid_t exec_start_migration(const char *command, int *fd) {
+static pid_t exec_start_migration(const char *command, int *fd,
unsigned char incoming) {
const char *argv[] = { "sh", "-c", command, NULL };
- int fds[2];
+ int fds[2], parent_fd, child_fd;
pid_t pid;
if (pipe(fds) == -1) {
@@ -78,6 +78,16 @@ static pid_t exec_start_migration(const char
*command, int *fd) {
return 0;
}
+ if(incoming) {
+ /* child writes, parent reads */
+ parent_fd = fds[0];
+ child_fd = fds[1];
+ } else {
+ /* parent writes, child reads */
+ parent_fd = fds[1];
+ child_fd = fds[0];
+ }
+
pid = fork();
if(pid == -1) {
close(fds[0]);
@@ -86,16 +96,14 @@ static pid_t exec_start_migration(const char
*command, int *fd) {
return 0;
} else if (pid == 0) {
/* child process */
- close(fds[1]);
- dup2(fds[0], STDIN_FILENO);
+ close(parent_fd);
+ dup2(child_fd, incoming ? STDOUT_FILENO : STDIN_FILENO);
execv("/bin/sh", (char **)argv);
exit(1);
}
- close(fds[0]);
-
- fcntl(fds[1], O_NONBLOCK);
-
- *fd = fds[1];
+ close(child_fd);
+ fcntl(parent_fd, O_NONBLOCK);
+ *fd = parent_fd;
return pid;
}
@@ -106,7 +114,7 @@ MigrationState
*exec_start_outgoing_migration(const char *command,
FdMigrationState *s;
int fd, pid;
- pid = exec_start_migration(command, &fd);
+ pid = exec_start_migration(command, &fd, 0);
if(!pid) return NULL;
s = qemu_mallocz(sizeof(*s));
@@ -136,7 +144,8 @@ MigrationState
*exec_start_outgoing_migration(const char *command,
/* helper for incoming case */
static void exec_accept_incoming_migration(void *opaque)
{
- QEMUFile *f = opaque;
+ ExecMigrationState *s = opaque;
+ QEMUFile *f = qemu_popen(fdopen(s->fd, "rb"), "r");
int ret;
ret = qemu_loadvm_state(f);
@@ -153,22 +162,24 @@ static void
exec_accept_incoming_migration(void *opaque)
err:
qemu_fclose(f);
+ do {
+ waitpid(s->pid, NULL, 0);
+ } while (ret == -1 && errno == EINTR);
+ qemu_free(s);
}
int exec_start_incoming_migration(const char *command)
{
- QEMUFile *f;
+ ExecMigrationState *s;
+
+ s = qemu_mallocz(sizeof(*s));
- dprintf("Attempting to start an incoming migration\n");
- f = qemu_popen_cmd(command, "r");
- if(f == NULL) {
- dprintf("Unable to apply qemu wrapper to popen file\n");
+ s->pid = exec_start_migration(command, &(s->fd), 1);
+ if(!s->pid) {
return -errno;
}
- qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
- exec_accept_incoming_migration, NULL,
- (void *)(unsigned long)f);
+ qemu_set_fd_handler2(s->fd, NULL,
exec_accept_incoming_migration, NULL, (void*)s);
return 0;
}
--
1.6.4