On Wed, 9 Jan 2013 21:02:37 +0000 Blue Swirl <blauwir...@gmail.com> wrote:
> On Tue, Jan 8, 2013 at 11:00 PM, Michael Roth <mdr...@linux.vnet.ibm.com> > wrote: > > From: Tomoki Sekiyama <tomoki.sekiyama...@hitachi.com> > > > > To use the online disk snapshot for online-backup, application-level > > consistency of the snapshot image is required. However, currently the > > guest agent can provide only filesystem-level consistency, and the > > snapshot may contain dirty data, for example, incomplete transactions. > > This patch provides the opportunity to quiesce applications before > > snapshot is taken. > > > > If --fsfreeze-hook option is specified, the hook is executed with > > "freeze" argument before the filesystem is frozen by fsfreeze-freeze > > command. As for fsfreeze-thaw command, the hook is executed with "thaw" > > argument after the filesystem is thawed. > > > > This patch depends on patchset to improve error reporting by Luiz > > Capitulino: > > http://lists.gnu.org/archive/html/qemu-devel/2012-11/msg03016.html > > > > Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama...@hitachi.com> > > Reviewed-by: Luiz Capitulino <lcapitul...@redhat.com> > > > > *clarified usage in help output > > > > Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com> > > --- > > qga/commands-posix.c | 69 > > ++++++++++++++++++++++++++++++++++++++++++++++++ > > qga/guest-agent-core.h | 1 + > > qga/main.c | 48 ++++++++++++++++++++++++++++++++- > > 3 files changed, 117 insertions(+), 1 deletion(-) > > > > diff --git a/qga/commands-posix.c b/qga/commands-posix.c > > index 614a421..77f6ee7 100644 > > --- a/qga/commands-posix.c > > +++ b/qga/commands-posix.c > > @@ -410,6 +410,66 @@ static void build_fs_mount_list(FsMountList *mounts, > > Error **err) > > > > #if defined(CONFIG_FSFREEZE) > > > > +typedef enum { > > + FSFREEZE_HOOK_THAW = 0, > > + FSFREEZE_HOOK_FREEZE, > > +} FsfreezeHookArg; > > + > > +const char *fsfreeze_hook_arg_string[] = { > > static This has already been merged. It's quite of a minor change anyway. > > > + "thaw", > > + "freeze", > > +}; > > + > > +static void execute_fsfreeze_hook(FsfreezeHookArg arg, Error **err) > > +{ > > + int status; > > + pid_t pid; > > + const char *hook; > > + const char *arg_str = fsfreeze_hook_arg_string[arg]; > > + Error *local_err = NULL; > > + > > + hook = ga_fsfreeze_hook(ga_state); > > + if (!hook) { > > + return; > > + } > > + if (access(hook, X_OK) != 0) { > > + error_setg_errno(err, errno, "can't access fsfreeze hook '%s'", > > hook); > > + return; > > + } > > + > > + slog("executing fsfreeze hook with arg '%s'", arg_str); > > + pid = fork(); > > + if (pid == 0) { > > + setsid(); > > + reopen_fd_to_null(0); > > + reopen_fd_to_null(1); > > + reopen_fd_to_null(2); > > + > > + execle(hook, hook, arg_str, NULL, environ); > > + _exit(EXIT_FAILURE); > > + } else if (pid < 0) { > > + error_setg_errno(err, errno, "failed to create child process"); > > + return; > > + } > > + > > + ga_wait_child(pid, &status, &local_err); > > + if (error_is_set(&local_err)) { > > + error_propagate(err, local_err); > > + return; > > + } > > + > > + if (!WIFEXITED(status)) { > > + error_setg(err, "fsfreeze hook has terminated abnormally"); > > + return; > > + } > > + > > + status = WEXITSTATUS(status); > > + if (status) { > > + error_setg(err, "fsfreeze hook has failed with status %d", status); > > + return; > > + } > > +} > > + > > /* > > * Return status of freeze/thaw > > */ > > @@ -436,6 +496,12 @@ int64_t qmp_guest_fsfreeze_freeze(Error **err) > > > > slog("guest-fsfreeze called"); > > > > + execute_fsfreeze_hook(FSFREEZE_HOOK_FREEZE, &local_err); > > + if (error_is_set(&local_err)) { > > + error_propagate(err, local_err); > > + return -1; > > + } > > + > > QTAILQ_INIT(&mounts); > > build_fs_mount_list(&mounts, &local_err); > > if (error_is_set(&local_err)) { > > @@ -537,6 +603,9 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err) > > > > ga_unset_frozen(ga_state); > > free_fs_mount_list(&mounts); > > + > > + execute_fsfreeze_hook(FSFREEZE_HOOK_THAW, err); > > + > > return i; > > } > > > > diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h > > index 8934163..3354598 100644 > > --- a/qga/guest-agent-core.h > > +++ b/qga/guest-agent-core.h > > @@ -34,6 +34,7 @@ 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); > > +const char *ga_fsfreeze_hook(GAState *s); > > > > #ifndef _WIN32 > > void reopen_fd_to_null(int fd); > > diff --git a/qga/main.c b/qga/main.c > > index ba5fa1c..a9b968c 100644 > > --- a/qga/main.c > > +++ b/qga/main.c > > @@ -34,6 +34,12 @@ > > #include "qga/service-win32.h" > > #include <windows.h> > > #endif > > +#ifdef __linux__ > > +#include <linux/fs.h> > > +#ifdef FIFREEZE > > +#define CONFIG_FSFREEZE > > +#endif > > +#endif > > > > #ifndef _WIN32 > > #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0" > > @@ -42,6 +48,9 @@ > > #endif > > #define QGA_STATEDIR_DEFAULT CONFIG_QEMU_LOCALSTATEDIR "/run" > > #define QGA_PIDFILE_DEFAULT QGA_STATEDIR_DEFAULT "/qemu-ga.pid" > > +#ifdef CONFIG_FSFREEZE > > +#define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook" > > +#endif > > #define QGA_SENTINEL_BYTE 0xFF > > > > struct GAState { > > @@ -64,6 +73,9 @@ struct GAState { > > const char *log_filepath; > > const char *pid_filepath; > > } deferred_options; > > +#ifdef CONFIG_FSFREEZE > > + const char *fsfreeze_hook; > > +#endif > > }; > > > > struct GAState *ga_state; > > @@ -153,6 +165,16 @@ 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" > > +#ifdef CONFIG_FSFREEZE > > +" -F, --fsfreeze-hook\n" > > +" enable fsfreeze hook. Accepts an optional argument > > that\n" > > +" specifies script to run on freeze/thaw. Script will > > be\n" > > +" called with 'freeze'/'thaw' arguments accordingly.\n" > > +" (default is %s)\n" > > +" If using -F with an argument, do not follow -F with > > a\n" > > +" space.\n" > > +" (for example: -F/var/run/fsfreezehook.sh)\n" > > +#endif > > " -t, --statedir specify dir to store state information (absolute > > paths\n" > > " only, default is %s)\n" > > " -v, --verbose log extra debugging information\n" > > @@ -167,6 +189,9 @@ static void usage(const char *cmd) > > "\n" > > "Report bugs to <mdr...@linux.vnet.ibm.com>\n" > > , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT, > > +#ifdef CONFIG_FSFREEZE > > + QGA_FSFREEZE_HOOK_DEFAULT, > > +#endif > > QGA_STATEDIR_DEFAULT); > > } > > > > @@ -401,6 +426,13 @@ void ga_unset_frozen(GAState *s) > > } > > } > > > > +#ifdef CONFIG_FSFREEZE > > +const char *ga_fsfreeze_hook(GAState *s) > > +{ > > + return s->fsfreeze_hook; > > +} > > +#endif > > + > > static void become_daemon(const char *pidfile) > > { > > #ifndef _WIN32 > > @@ -678,10 +710,13 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[]) > > > > int main(int argc, char **argv) > > { > > - const char *sopt = "hVvdm:p:l:f:b:s:t:"; > > + const char *sopt = "hVvdm:p:l:f:F::b:s:t:"; > > const char *method = NULL, *path = NULL; > > const char *log_filepath = NULL; > > const char *pid_filepath = QGA_PIDFILE_DEFAULT; > > +#ifdef CONFIG_FSFREEZE > > + const char *fsfreeze_hook = NULL; > > +#endif > > const char *state_dir = QGA_STATEDIR_DEFAULT; > > #ifdef _WIN32 > > const char *service = NULL; > > @@ -691,6 +726,9 @@ int main(int argc, char **argv) > > { "version", 0, NULL, 'V' }, > > { "logfile", 1, NULL, 'l' }, > > { "pidfile", 1, NULL, 'f' }, > > +#ifdef CONFIG_FSFREEZE > > + { "fsfreeze-hook", 2, NULL, 'F' }, > > +#endif > > { "verbose", 0, NULL, 'v' }, > > { "method", 1, NULL, 'm' }, > > { "path", 1, NULL, 'p' }, > > @@ -723,6 +761,11 @@ int main(int argc, char **argv) > > case 'f': > > pid_filepath = optarg; > > break; > > +#ifdef CONFIG_FSFREEZE > > + case 'F': > > + fsfreeze_hook = optarg ? optarg : QGA_FSFREEZE_HOOK_DEFAULT; > > + break; > > +#endif > > case 't': > > state_dir = optarg; > > break; > > @@ -786,6 +829,9 @@ int main(int argc, char **argv) > > s = g_malloc0(sizeof(GAState)); > > s->log_level = log_level; > > s->log_file = stderr; > > +#ifdef CONFIG_FSFREEZE > > + s->fsfreeze_hook = fsfreeze_hook; > > +#endif > > g_log_set_default_handler(ga_log, s); > > g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR); > > ga_enable_logging(s); > > -- > > 1.7.9.5 > > > > >