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Merge remote-tracking branch 'mdroth/qga-pull-4-27-12' into staging 

* mdroth/qga-pull-4-27-12:
  qemu-ga: persist tracking of fsfreeze state via filesystem
  qemu-ga: add a whitelist for fsfreeze-safe commands
  qemu-ga: improve recovery options for fsfreeze
master
Anthony Liguori 2012-05-01 18:44:03 -05:00
parent 65074706b9 f789aa7baf
commit 75e4e8475b
6 changed files with 409 additions and 138 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
qapi-schema-guest.json
View File

@ -296,14 +296,10 @@
#
# @frozen: all non-network guest filesystems frozen
#
# @error: failure to thaw 1 or more
# previously frozen filesystems, or failure to open a previously
# cached filesytem (filesystem unmounted/directory changes, etc).
#
# Since: 0.15.0
##
{ 'enum': 'GuestFsfreezeStatus',
'data': [ 'thawed', 'frozen', 'error' ] }
'data': [ 'thawed', 'frozen' ] }
##
# @guest-fsfreeze-status:
@ -312,6 +308,9 @@
#
# Returns: GuestFsfreezeStatus ("thawed", "frozen", etc., as defined below)
#
# Note: This may fail to properly report the current state as a result of
# some other guest processes having issued an fs freeze/thaw.
#
# Since: 0.15.0
##
{ 'command': 'guest-fsfreeze-status',
@ -320,9 +319,10 @@
##
# @guest-fsfreeze-freeze:
#
# Sync and freeze all non-network guest filesystems
# Sync and freeze all freezable, local guest filesystems
#
# Returns: Number of file systems frozen on success
# Returns: Number of file systems currently frozen. On error, all filesystems
# will be thawed.
#
# Since: 0.15.0
##
@ -332,10 +332,15 @@
##
# @guest-fsfreeze-thaw:
#
# Unfreeze frozen guest fileystems
# Unfreeze all frozen guest filesystems
#
# Returns: Number of file systems thawed
# If error, -1 (unknown error) or -errno
# Returns: Number of file systems thawed by this call
#
# Note: if return value does not match the previous call to
# guest-fsfreeze-freeze, this likely means some freezable
# filesystems were unfrozen before this call, and that the
# filesystem state may have changed before issuing this
# command.
#
# Since: 0.15.0
##

1
qapi/qmp-core.h
View File

@ -38,6 +38,7 @@ void qmp_register_command(const char *name, QmpCommandFunc *fn);
QmpCommand *qmp_find_command(const char *name);
QObject *qmp_dispatch(QObject *request);
void qmp_disable_command(const char *name);
void qmp_enable_command(const char *name);
bool qmp_command_is_enabled(const char *name);
char **qmp_get_command_list(void);

14
qapi/qmp-registry.c
View File

@ -40,18 +40,28 @@ QmpCommand *qmp_find_command(const char *name)
return NULL;
}
void qmp_disable_command(const char *name)
static void qmp_toggle_command(const char *name, bool enabled)
{
QmpCommand *cmd;
QTAILQ_FOREACH(cmd, &qmp_commands, node) {
if (strcmp(cmd->name, name) == 0) {
cmd->enabled = false;
cmd->enabled = enabled;
return;
}
}
}
void qmp_disable_command(const char *name)
{
qmp_toggle_command(name, false);
}
void qmp_enable_command(const char *name)
{
qmp_toggle_command(name, true);
}
bool qmp_command_is_enabled(const char *name)
{
QmpCommand *cmd;

334
qemu-ga.c
View File

@ -18,6 +18,7 @@
#ifndef _WIN32
#include <syslog.h>
#include <sys/wait.h>
#include <sys/stat.h>
#endif
#include "json-streamer.h"
#include "json-parser.h"
@ -41,6 +42,7 @@
#define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
#endif
#define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"
#define QGA_STATEDIR_DEFAULT "/tmp"
#define QGA_SENTINEL_BYTE 0xFF
struct GAState {
@ -56,10 +58,27 @@ struct GAState {
GAService service;
#endif
bool delimit_response;
bool frozen;
GList *blacklist;
const char *state_filepath_isfrozen;
struct {
const char *log_filepath;
const char *pid_filepath;
} deferred_options;
};
struct GAState *ga_state;
/* commands that are safe to issue while filesystems are frozen */
static const char *ga_freeze_whitelist[] = {
"guest-ping",
"guest-info",
"guest-sync",
"guest-fsfreeze-status",
"guest-fsfreeze-thaw",
NULL
};
#ifdef _WIN32
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
LPVOID ctx);
@ -68,6 +87,15 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
static void quit_handler(int sig)
{
/* if we're frozen, don't exit unless we're absolutely forced to,
* because it's basically impossible for graceful exit to complete
* unless all log/pid files are on unfreezable filesystems. there's
* also a very likely chance killing the agent before unfreezing
* the filesystems is a mistake (or will be viewed as one later).
*/
if (ga_is_frozen(ga_state)) {
return;
}
g_debug("received signal num %d, quitting", sig);
if (g_main_loop_is_running(ga_state->main_loop)) {
@ -126,6 +154,8 @@ static void usage(const char *cmd)
" %s)\n"
" -l, --logfile set logfile path, logs to stderr by default\n"
" -f, --pidfile specify pidfile (default is %s)\n"
" -t, --statedir specify dir to store state information (absolute paths\n"
" only, default is %s)\n"
" -v, --verbose log extra debugging information\n"
" -V, --version print version information and exit\n"
" -d, --daemonize become a daemon\n"
@ -137,7 +167,8 @@ static void usage(const char *cmd)
" -h, --help display this help and exit\n"
"\n"
"Report bugs to <mdroth@linux.vnet.ibm.com>\n"
, cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT);
, cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT,
QGA_STATEDIR_DEFAULT);
}
static const char *ga_log_level_str(GLogLevelFlags level)
@ -207,11 +238,171 @@ void ga_set_response_delimited(GAState *s)
}
#ifndef _WIN32
static bool ga_open_pidfile(const char *pidfile)
{
int pidfd;
char pidstr[32];
pidfd = open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
g_critical("Cannot lock pid file, %s", strerror(errno));
return false;
}
if (ftruncate(pidfd, 0) || lseek(pidfd, 0, SEEK_SET)) {
g_critical("Failed to truncate pid file");
goto fail;
}
sprintf(pidstr, "%d", getpid());
if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
g_critical("Failed to write pid file");
goto fail;
}
return true;
fail:
unlink(pidfile);
return false;
}
#else /* _WIN32 */
static bool ga_open_pidfile(const char *pidfile)
{
return true;
}
#endif
static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
{
return strcmp(str1, str2);
}
/* disable commands that aren't safe for fsfreeze */
static void ga_disable_non_whitelisted(void)
{
char **list_head, **list;
bool whitelisted;
int i;
list_head = list = qmp_get_command_list();
while (*list != NULL) {
whitelisted = false;
i = 0;
while (ga_freeze_whitelist[i] != NULL) {
if (strcmp(*list, ga_freeze_whitelist[i]) == 0) {
whitelisted = true;
}
i++;
}
if (!whitelisted) {
g_debug("disabling command: %s", *list);
qmp_disable_command(*list);
}
g_free(*list);
list++;
}
g_free(list_head);
}
/* [re-]enable all commands, except those explictly blacklisted by user */
static void ga_enable_non_blacklisted(GList *blacklist)
{
char **list_head, **list;
list_head = list = qmp_get_command_list();
while (*list != NULL) {
if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL &&
!qmp_command_is_enabled(*list)) {
g_debug("enabling command: %s", *list);
qmp_enable_command(*list);
}
g_free(*list);
list++;
}
g_free(list_head);
}
static bool ga_create_file(const char *path)
{
int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
if (fd == -1) {
g_warning("unable to open/create file %s: %s", path, strerror(errno));
return false;
}
close(fd);
return true;
}
static bool ga_delete_file(const char *path)
{
int ret = unlink(path);
if (ret == -1) {
g_warning("unable to delete file: %s: %s", path, strerror(errno));
return false;
}
return true;
}
bool ga_is_frozen(GAState *s)
{
return s->frozen;
}
void ga_set_frozen(GAState *s)
{
if (ga_is_frozen(s)) {
return;
}
/* disable all non-whitelisted (for frozen state) commands */
ga_disable_non_whitelisted();
g_warning("disabling logging due to filesystem freeze");
ga_disable_logging(s);
s->frozen = true;
if (!ga_create_file(s->state_filepath_isfrozen)) {
g_warning("unable to create %s, fsfreeze may not function properly",
s->state_filepath_isfrozen);
}
}
void ga_unset_frozen(GAState *s)
{
if (!ga_is_frozen(s)) {
return;
}
/* if we delayed creation/opening of pid/log files due to being
* in a frozen state at start up, do it now
*/
if (s->deferred_options.log_filepath) {
s->log_file = fopen(s->deferred_options.log_filepath, "a");
if (!s->log_file) {
s->log_file = stderr;
}
s->deferred_options.log_filepath = NULL;
}
ga_enable_logging(s);
g_warning("logging re-enabled due to filesystem unfreeze");
if (s->deferred_options.pid_filepath) {
if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
g_warning("failed to create/open pid file");
}
s->deferred_options.pid_filepath = NULL;
}
/* enable all disabled, non-blacklisted commands */
ga_enable_non_blacklisted(s->blacklist);
s->frozen = false;
if (!ga_delete_file(s->state_filepath_isfrozen)) {
g_warning("unable to delete %s, fsfreeze may not function properly",
s->state_filepath_isfrozen);
}
}
static void become_daemon(const char *pidfile)
{
#ifndef _WIN32
pid_t pid, sid;
int pidfd;
char *pidstr = NULL;
pid = fork();
if (pid < 0) {
@ -221,20 +412,11 @@ static void become_daemon(const char *pidfile)
exit(EXIT_SUCCESS);
}
pidfd = open(pidfile, O_CREAT|O_WRONLY|O_EXCL, S_IRUSR|S_IWUSR);
if (pidfd == -1) {
g_critical("Cannot create pid file, %s", strerror(errno));
exit(EXIT_FAILURE);
}
if (asprintf(&pidstr, "%d", getpid()) == -1) {
g_critical("Cannot allocate memory");
goto fail;
}
if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
free(pidstr);
g_critical("Failed to write pid file");
goto fail;
if (pidfile) {
if (!ga_open_pidfile(pidfile)) {
g_critical("failed to create pidfile");
exit(EXIT_FAILURE);
}
}
umask(0);
@ -249,15 +431,14 @@ static void become_daemon(const char *pidfile)
close(STDIN_FILENO);
close(STDOUT_FILENO);
close(STDERR_FILENO);
free(pidstr);
return;
fail:
unlink(pidfile);
g_critical("failed to daemonize");
exit(EXIT_FAILURE);
}
#endif
}
static int send_response(GAState *s, QObject *payload)
{
@ -495,9 +676,11 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
int main(int argc, char **argv)
{
const char *sopt = "hVvdm:p:l:f:b:s:";
const char *method = NULL, *path = NULL, *pidfile = QGA_PIDFILE_DEFAULT;
const char *log_file_name = NULL;
const char *sopt = "hVvdm:p:l:f:b:s:t:";
const char *method = NULL, *path = NULL;
const char *log_filepath = NULL;
const char *pid_filepath = QGA_PIDFILE_DEFAULT;
const char *state_dir = QGA_STATEDIR_DEFAULT;
#ifdef _WIN32
const char *service = NULL;
#endif
@ -513,12 +696,13 @@ int main(int argc, char **argv)
{ "blacklist", 1, NULL, 'b' },
#ifdef _WIN32
{ "service", 1, NULL, 's' },
#endif
#endif
{ "statedir", 1, NULL, 't' },
{ NULL, 0, NULL, 0 }
};
int opt_ind = 0, ch, daemonize = 0, i, j, len;
GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
FILE *log_file = stderr;
GList *blacklist = NULL;
GAState *s;
module_call_init(MODULE_INIT_QAPI);
@ -532,17 +716,14 @@ int main(int argc, char **argv)
path = optarg;
break;
case 'l':
log_file_name = optarg;
log_file = fopen(log_file_name, "a");
if (!log_file) {
g_critical("unable to open specified log file: %s",
strerror(errno));
return EXIT_FAILURE;
}
log_filepath = optarg;
break;
case 'f':
pidfile = optarg;
pid_filepath = optarg;
break;
case 't':
state_dir = optarg;
break;
case 'v':
/* enable all log levels */
log_level = G_LOG_LEVEL_MASK;
@ -568,14 +749,12 @@ int main(int argc, char **argv)
for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
if (optarg[i] == ',') {
optarg[i] = 0;
qmp_disable_command(&optarg[j]);
g_debug("disabling command: %s", &optarg[j]);
blacklist = g_list_append(blacklist, &optarg[j]);
j = i + 1;
}
}
if (j < i) {
qmp_disable_command(&optarg[j]);
g_debug("disabling command: %s", &optarg[j]);
blacklist = g_list_append(blacklist, &optarg[j]);
}
break;
}
@ -583,7 +762,7 @@ int main(int argc, char **argv)
case 's':
service = optarg;
if (strcmp(service, "install") == 0) {
return ga_install_service(path, log_file_name);
return ga_install_service(path, log_filepath);
} else if (strcmp(service, "uninstall") == 0) {
return ga_uninstall_service();
} else {
@ -602,19 +781,78 @@ int main(int argc, char **argv)
}
}
s = g_malloc0(sizeof(GAState));
s->log_level = log_level;
s->log_file = stderr;
g_log_set_default_handler(ga_log, s);
g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
ga_enable_logging(s);
s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
state_dir);
s->frozen = false;
#ifndef _WIN32
if (daemonize) {
g_debug("starting daemon");
become_daemon(pidfile);
/* check if a previous instance of qemu-ga exited with filesystems' state
* marked as frozen. this could be a stale value (a non-qemu-ga process
* or reboot may have since unfrozen them), but better to require an
* uneeded unfreeze than to risk hanging on start-up
*/
struct stat st;
if (stat(s->state_filepath_isfrozen, &st) == -1) {
/* it's okay if the file doesn't exist, but if we can't access for
* some other reason, such as permissions, there's a configuration
* that needs to be addressed. so just bail now before we get into
* more trouble later
*/
if (errno != ENOENT) {
g_critical("unable to access state file at path %s: %s",
s->state_filepath_isfrozen, strerror(errno));
return EXIT_FAILURE;
}
} else {
g_warning("previous instance appears to have exited with frozen"
" filesystems. deferring logging/pidfile creation and"
" disabling non-fsfreeze-safe commands until"
" guest-fsfreeze-thaw is issued, or filesystems are"
" manually unfrozen and the file %s is removed",
s->state_filepath_isfrozen);
s->frozen = true;
}
#endif
s = g_malloc0(sizeof(GAState));
s->log_file = log_file;
s->log_level = log_level;
g_log_set_default_handler(ga_log, s);
g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
s->logging_enabled = true;
if (ga_is_frozen(s)) {
if (daemonize) {
/* delay opening/locking of pidfile till filesystem are unfrozen */
s->deferred_options.pid_filepath = pid_filepath;
become_daemon(NULL);
}
if (log_filepath) {
/* delay opening the log file till filesystems are unfrozen */
s->deferred_options.log_filepath = log_filepath;
}
ga_disable_logging(s);
ga_disable_non_whitelisted();
} else {
if (daemonize) {
become_daemon(pid_filepath);
}
if (log_filepath) {
s->log_file = fopen(log_filepath, "a");
if (!s->log_file) {
g_critical("unable to open specified log file: %s",
strerror(errno));
goto out_bad;
}
}
}
if (blacklist) {
s->blacklist = blacklist;
do {
g_debug("disabling command: %s", (char *)blacklist->data);
qmp_disable_command(blacklist->data);
blacklist = g_list_next(blacklist);
} while (blacklist);
}
s->command_state = ga_command_state_new();
ga_command_state_init(s, s->command_state);
ga_command_state_init_all(s->command_state);
@ -648,13 +886,13 @@ int main(int argc, char **argv)
ga_channel_free(ga_state->channel);
if (daemonize) {
unlink(pidfile);
unlink(pid_filepath);
}
return 0;
out_bad:
if (daemonize) {
unlink(pidfile);
unlink(pid_filepath);
}
return EXIT_FAILURE;
}

170
qga/commands-posix.c
View File

@ -316,44 +316,40 @@ static void guest_file_init(void)
#if defined(CONFIG_FSFREEZE)
static void disable_logging(void)
{
ga_disable_logging(ga_state);
}
static void enable_logging(void)
{
ga_enable_logging(ga_state);
}
typedef struct GuestFsfreezeMount {
char *dirname;
char *devtype;
QTAILQ_ENTRY(GuestFsfreezeMount) next;
} GuestFsfreezeMount;
struct {
GuestFsfreezeStatus status;
QTAILQ_HEAD(, GuestFsfreezeMount) mount_list;
} guest_fsfreeze_state;
typedef QTAILQ_HEAD(, GuestFsfreezeMount) GuestFsfreezeMountList;
static void guest_fsfreeze_free_mount_list(GuestFsfreezeMountList *mounts)
{
GuestFsfreezeMount *mount, *temp;
if (!mounts) {
return;
}
QTAILQ_FOREACH_SAFE(mount, mounts, next, temp) {
QTAILQ_REMOVE(mounts, mount, next);
g_free(mount->dirname);
g_free(mount->devtype);
g_free(mount);
}
}
/*
* Walk the mount table and build a list of local file systems
*/
static int guest_fsfreeze_build_mount_list(void)
static int guest_fsfreeze_build_mount_list(GuestFsfreezeMountList *mounts)
{
struct mntent *ment;
GuestFsfreezeMount *mount, *temp;
GuestFsfreezeMount *mount;
char const *mtab = MOUNTED;
FILE *fp;
QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) {
QTAILQ_REMOVE(&guest_fsfreeze_state.mount_list, mount, next);
g_free(mount->dirname);
g_free(mount->devtype);
g_free(mount);
}
fp = setmntent(mtab, "r");
if (!fp) {
g_warning("fsfreeze: unable to read mtab");
@ -377,7 +373,7 @@ static int guest_fsfreeze_build_mount_list(void)
mount->dirname = g_strdup(ment->mnt_dir);
mount->devtype = g_strdup(ment->mnt_type);
QTAILQ_INSERT_TAIL(&guest_fsfreeze_state.mount_list, mount, next);
QTAILQ_INSERT_TAIL(mounts, mount, next);
}
endmntent(fp);
@ -390,7 +386,11 @@ static int guest_fsfreeze_build_mount_list(void)
*/
GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err)
{
return guest_fsfreeze_state.status;
if (ga_is_frozen(ga_state)) {
return GUEST_FSFREEZE_STATUS_FROZEN;
}
return GUEST_FSFREEZE_STATUS_THAWED;
}
/*
@ -400,61 +400,61 @@ GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err)
int64_t qmp_guest_fsfreeze_freeze(Error **err)
{
int ret = 0, i = 0;
struct GuestFsfreezeMount *mount, *temp;
GuestFsfreezeMountList mounts;
struct GuestFsfreezeMount *mount;
int fd;
char err_msg[512];
slog("guest-fsfreeze called");
if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) {
return 0;
}
ret = guest_fsfreeze_build_mount_list();
QTAILQ_INIT(&mounts);
ret = guest_fsfreeze_build_mount_list(&mounts);
if (ret < 0) {
return ret;
}
/* cannot risk guest agent blocking itself on a write in this state */
disable_logging();
ga_set_frozen(ga_state);
QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) {
QTAILQ_FOREACH(mount, &mounts, next) {
fd = qemu_open(mount->dirname, O_RDONLY);
if (fd == -1) {
sprintf(err_msg, "failed to open %s, %s", mount->dirname, strerror(errno));
sprintf(err_msg, "failed to open %s, %s", mount->dirname,
strerror(errno));
error_set(err, QERR_QGA_COMMAND_FAILED, err_msg);
goto error;
}
/* we try to cull filesytems we know won't work in advance, but other
* filesytems may not implement fsfreeze for less obvious reasons.
* these will report EOPNOTSUPP, so we simply ignore them. when
* thawing, these filesystems will return an EINVAL instead, due to
* not being in a frozen state. Other filesystem-specific
* errors may result in EINVAL, however, so the user should check the
* number * of filesystems returned here against those returned by the
* thaw operation to determine whether everything completed
* successfully
* these will report EOPNOTSUPP. we simply ignore these when tallying
* the number of frozen filesystems.
*
* any other error means a failure to freeze a filesystem we
* expect to be freezable, so return an error in those cases
* and return system to thawed state.
*/
ret = ioctl(fd, FIFREEZE);
if (ret < 0 && errno != EOPNOTSUPP) {
sprintf(err_msg, "failed to freeze %s, %s", mount->dirname, strerror(errno));
error_set(err, QERR_QGA_COMMAND_FAILED, err_msg);
close(fd);
goto error;
if (ret == -1) {
if (errno != EOPNOTSUPP) {
sprintf(err_msg, "failed to freeze %s, %s",
mount->dirname, strerror(errno));
error_set(err, QERR_QGA_COMMAND_FAILED, err_msg);
close(fd);
goto error;
}
} else {
i++;
}
close(fd);
i++;
}
guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_FROZEN;
guest_fsfreeze_free_mount_list(&mounts);
return i;
error:
if (i > 0) {
qmp_guest_fsfreeze_thaw(NULL);
}
guest_fsfreeze_free_mount_list(&mounts);
qmp_guest_fsfreeze_thaw(NULL);
return 0;
}
@ -464,47 +464,61 @@ error:
int64_t qmp_guest_fsfreeze_thaw(Error **err)
{
int ret;
GuestFsfreezeMount *mount, *temp;
int fd, i = 0;
bool has_error = false;
GuestFsfreezeMountList mounts;
GuestFsfreezeMount *mount;
int fd, i = 0, logged;
QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) {
QTAILQ_INIT(&mounts);
ret = guest_fsfreeze_build_mount_list(&mounts);
if (ret) {
error_set(err, QERR_QGA_COMMAND_FAILED,
"failed to enumerate filesystems");
return 0;
}
QTAILQ_FOREACH(mount, &mounts, next) {
logged = false;
fd = qemu_open(mount->dirname, O_RDONLY);
if (fd == -1) {
has_error = true;
continue;
}
ret = ioctl(fd, FITHAW);
if (ret < 0 && errno != EOPNOTSUPP && errno != EINVAL) {
has_error = true;
close(fd);
continue;
}
/* we have no way of knowing whether a filesystem was actually unfrozen
* as a result of a successful call to FITHAW, only that if an error
* was returned the filesystem was *not* unfrozen by that particular
* call.
*
* since multiple preceeding FIFREEZEs require multiple calls to FITHAW
* to unfreeze, continuing issuing FITHAW until an error is returned,
* in which case either the filesystem is in an unfreezable state, or,
* more likely, it was thawed previously (and remains so afterward).
*
* also, since the most recent successful call is the one that did
* the actual unfreeze, we can use this to provide an accurate count
* of the number of filesystems unfrozen by guest-fsfreeze-thaw, which
* may * be useful for determining whether a filesystem was unfrozen
* during the freeze/thaw phase by a process other than qemu-ga.
*/
do {
ret = ioctl(fd, FITHAW);
if (ret == 0 && !logged) {
i++;
logged = true;
}
} while (ret == 0);
close(fd);
i++;
}
if (has_error) {
guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_ERROR;
} else {
guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED;
}
enable_logging();
ga_unset_frozen(ga_state);
guest_fsfreeze_free_mount_list(&mounts);
return i;
}
static void guest_fsfreeze_init(void)
{
guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED;
QTAILQ_INIT(&guest_fsfreeze_state.mount_list);
}
static void guest_fsfreeze_cleanup(void)
{
int64_t ret;
Error *err = NULL;
if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) {
if (ga_is_frozen(ga_state) == GUEST_FSFREEZE_STATUS_FROZEN) {
ret = qmp_guest_fsfreeze_thaw(&err);
if (ret < 0 || err) {
slog("failed to clean up frozen filesystems");
@ -933,7 +947,7 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err)
void ga_command_state_init(GAState *s, GACommandState *cs)
{
#if defined(CONFIG_FSFREEZE)
ga_command_state_add(cs, guest_fsfreeze_init, guest_fsfreeze_cleanup);
ga_command_state_add(cs, NULL, guest_fsfreeze_cleanup);
#endif
ga_command_state_add(cs, guest_file_init, NULL);
}

3
qga/guest-agent-core.h
View File

@ -32,3 +32,6 @@ void ga_disable_logging(GAState *s);
void ga_enable_logging(GAState *s);
void slog(const gchar *fmt, ...);
void ga_set_response_delimited(GAState *s);
bool ga_is_frozen(GAState *s);
void ga_set_frozen(GAState *s);
void ga_unset_frozen(GAState *s);