qemu/migration-fd.c

127 lines
2.8 KiB
C

/*
* QEMU live migration via generic fd
*
* Copyright Red Hat, Inc. 2009
*
* Authors:
* Chris Lalancette <clalance@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "qemu-common.h"
#include "qemu_socket.h"
#include "migration.h"
#include "monitor.h"
#include "qemu-char.h"
#include "buffered_file.h"
#include "block.h"
#include "qemu_socket.h"
//#define DEBUG_MIGRATION_FD
#ifdef DEBUG_MIGRATION_FD
#define DPRINTF(fmt, ...) \
do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) \
do { } while (0)
#endif
static int fd_errno(MigrationState *s)
{
return errno;
}
static int fd_write(MigrationState *s, const void * buf, size_t size)
{
return write(s->fd, buf, size);
}
static int fd_close(MigrationState *s)
{
struct stat st;
int ret;
DPRINTF("fd_close\n");
if (s->fd != -1) {
ret = fstat(s->fd, &st);
if (ret == 0 && S_ISREG(st.st_mode)) {
/*
* If the file handle is a regular file make sure the
* data is flushed to disk before signaling success.
*/
ret = fsync(s->fd);
if (ret != 0) {
ret = -errno;
perror("migration-fd: fsync");
return ret;
}
}
ret = close(s->fd);
s->fd = -1;
if (ret != 0) {
ret = -errno;
perror("migration-fd: close");
return ret;
}
}
return 0;
}
int fd_start_outgoing_migration(MigrationState *s, const char *fdname)
{
s->fd = monitor_get_fd(s->mon, fdname);
if (s->fd == -1) {
DPRINTF("fd_migration: invalid file descriptor identifier\n");
goto err_after_get_fd;
}
if (fcntl(s->fd, F_SETFL, O_NONBLOCK) == -1) {
DPRINTF("Unable to set nonblocking mode on file descriptor\n");
goto err_after_open;
}
s->get_error = fd_errno;
s->write = fd_write;
s->close = fd_close;
migrate_fd_connect(s);
return 0;
err_after_open:
close(s->fd);
err_after_get_fd:
return -1;
}
static void fd_accept_incoming_migration(void *opaque)
{
QEMUFile *f = opaque;
process_incoming_migration(f);
qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
qemu_fclose(f);
}
int fd_start_incoming_migration(const char *infd)
{
int fd;
QEMUFile *f;
DPRINTF("Attempting to start an incoming migration via fd\n");
fd = strtol(infd, NULL, 0);
f = qemu_fdopen(fd, "rb");
if(f == NULL) {
DPRINTF("Unable to apply qemu wrapper to file descriptor\n");
return -errno;
}
qemu_set_fd_handler2(fd, NULL, fd_accept_incoming_migration, NULL, f);
return 0;
}