qga: Add UFS freeze/thaw support for FreeBSD

UFS supports FS freezing through ioctl UFSSUSPEND on /dev/ufssuspend.
Frozen FS can be thawed by closing /dev/ufssuspend file descriptior.

Use getmntinfo to get a list of mounted FS.

Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
This commit is contained in:
Alexander Ivanov 2022-10-17 09:28:21 +02:00 committed by Konstantin Kostiuk
parent 518b0d800b
commit bad0001eeb
5 changed files with 334 additions and 164 deletions

169
qga/commands-bsd.c Normal file
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@ -0,0 +1,169 @@
/*
* QEMU Guest Agent BSD-specific command implementations
*
* Copyright (c) Virtuozzo International GmbH.
*
* Authors:
* Alexander Ivanov <alexander.ivanov@virtuozzo.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qga-qapi-commands.h"
#include "qapi/qmp/qerror.h"
#include "qapi/error.h"
#include "qemu/queue.h"
#include "commands-common.h"
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/ucred.h>
#include <sys/mount.h>
#include <paths.h>
#if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
bool build_fs_mount_list(FsMountList *mounts, Error **errp)
{
FsMount *mount;
struct statfs *mntbuf, *mntp;
struct stat statbuf;
int i, count, ret;
count = getmntinfo(&mntbuf, MNT_NOWAIT);
if (count == 0) {
error_setg_errno(errp, errno, "getmntinfo failed");
return false;
}
for (i = 0; i < count; i++) {
mntp = &mntbuf[i];
ret = stat(mntp->f_mntonname, &statbuf);
if (ret != 0) {
error_setg_errno(errp, errno, "stat failed on %s",
mntp->f_mntonname);
return false;
}
mount = g_new0(FsMount, 1);
mount->dirname = g_strdup(mntp->f_mntonname);
mount->devtype = g_strdup(mntp->f_fstypename);
mount->devmajor = major(mount->dev);
mount->devminor = minor(mount->dev);
mount->fsid = mntp->f_fsid;
mount->dev = statbuf.st_dev;
QTAILQ_INSERT_TAIL(mounts, mount, next);
}
return true;
}
#endif /* CONFIG_FSFREEZE || CONFIG_FSTRIM */
#if defined(CONFIG_FSFREEZE)
static int ufssuspend_fd = -1;
static int ufssuspend_cnt;
int64_t qmp_guest_fsfreeze_do_freeze_list(bool has_mountpoints,
strList *mountpoints,
FsMountList mounts,
Error **errp)
{
int ret;
strList *list;
struct FsMount *mount;
if (ufssuspend_fd != -1) {
error_setg(errp, "filesystems have already frozen");
return -1;
}
ufssuspend_cnt = 0;
ufssuspend_fd = qemu_open(_PATH_UFSSUSPEND, O_RDWR, errp);
if (ufssuspend_fd == -1) {
return -1;
}
QTAILQ_FOREACH_REVERSE(mount, &mounts, next) {
/*
* To issue fsfreeze in the reverse order of mounts, check if the
* mount is listed in the list here
*/
if (has_mountpoints) {
for (list = mountpoints; list; list = list->next) {
if (g_str_equal(list->value, mount->dirname)) {
break;
}
}
if (!list) {
continue;
}
}
/* Only UFS supports suspend */
if (!g_str_equal(mount->devtype, "ufs")) {
continue;
}
ret = ioctl(ufssuspend_fd, UFSSUSPEND, &mount->fsid);
if (ret == -1) {
/*
* ioctl returns EBUSY for all the FS except the first one
* that was suspended
*/
if (errno == EBUSY) {
continue;
}
error_setg_errno(errp, errno, "failed to freeze %s",
mount->dirname);
goto error;
}
ufssuspend_cnt++;
}
return ufssuspend_cnt;
error:
close(ufssuspend_fd);
ufssuspend_fd = -1;
return -1;
}
/*
* We don't need to call UFSRESUME ioctl because all the frozen FS
* are thawed on /dev/ufssuspend closing.
*/
int qmp_guest_fsfreeze_do_thaw(Error **errp)
{
int ret = ufssuspend_cnt;
ufssuspend_cnt = 0;
if (ufssuspend_fd != -1) {
close(ufssuspend_fd);
ufssuspend_fd = -1;
}
return ret;
}
GuestFilesystemInfoList *qmp_guest_get_fsinfo(Error **errp)
{
error_setg(errp, QERR_UNSUPPORTED);
return NULL;
}
GuestDiskInfoList *qmp_guest_get_disks(Error **errp)
{
error_setg(errp, QERR_UNSUPPORTED);
return NULL;
}
GuestDiskStatsInfoList *qmp_guest_get_diskstats(Error **errp)
{
error_setg(errp, QERR_UNSUPPORTED);
return NULL;
}
GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
{
error_setg(errp, QERR_UNSUPPORTED);
return NULL;
}
#endif /* CONFIG_FSFREEZE */

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@ -23,11 +23,22 @@
#endif
#endif /* __linux__ */
#ifdef __FreeBSD__
#include <ufs/ffs/fs.h>
#ifdef UFSSUSPEND
#define CONFIG_FSFREEZE
#endif
#endif /* __FreeBSD__ */
#if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
typedef struct FsMount {
char *dirname;
char *devtype;
unsigned int devmajor, devminor;
#if defined(__FreeBSD__)
dev_t dev;
fsid_t fsid;
#endif
QTAILQ_ENTRY(FsMount) next;
} FsMount;

View File

@ -33,20 +33,12 @@
#if defined(__linux__)
#include <mntent.h>
#include <linux/fs.h>
#include <sys/statvfs.h>
#include <linux/nvme_ioctl.h>
#ifdef CONFIG_LIBUDEV
#include <libudev.h>
#endif
#ifdef FIFREEZE
#define CONFIG_FSFREEZE
#endif
#ifdef FITRIM
#define CONFIG_FSTRIM
#endif
#endif
#ifdef __FreeBSD__
@ -623,9 +615,6 @@ void qmp_guest_file_flush(int64_t handle, Error **errp)
}
}
/* linux-specific implementations. avoid this if at all possible. */
#if defined(__linux__)
#if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
void free_fs_mount_list(FsMountList *mounts)
{
@ -644,6 +633,156 @@ void free_fs_mount_list(FsMountList *mounts)
}
#endif
#if defined(CONFIG_FSFREEZE)
typedef enum {
FSFREEZE_HOOK_THAW = 0,
FSFREEZE_HOOK_FREEZE,
} FsfreezeHookArg;
static const char *fsfreeze_hook_arg_string[] = {
"thaw",
"freeze",
};
static void execute_fsfreeze_hook(FsfreezeHookArg arg, Error **errp)
{
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(errp, 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);
execl(hook, hook, arg_str, NULL);
_exit(EXIT_FAILURE);
} else if (pid < 0) {
error_setg_errno(errp, errno, "failed to create child process");
return;
}
ga_wait_child(pid, &status, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (!WIFEXITED(status)) {
error_setg(errp, "fsfreeze hook has terminated abnormally");
return;
}
status = WEXITSTATUS(status);
if (status) {
error_setg(errp, "fsfreeze hook has failed with status %d", status);
return;
}
}
/*
* Return status of freeze/thaw
*/
GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **errp)
{
if (ga_is_frozen(ga_state)) {
return GUEST_FSFREEZE_STATUS_FROZEN;
}
return GUEST_FSFREEZE_STATUS_THAWED;
}
int64_t qmp_guest_fsfreeze_freeze(Error **errp)
{
return qmp_guest_fsfreeze_freeze_list(false, NULL, errp);
}
int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
strList *mountpoints,
Error **errp)
{
int ret;
FsMountList mounts;
Error *local_err = NULL;
slog("guest-fsfreeze called");
execute_fsfreeze_hook(FSFREEZE_HOOK_FREEZE, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return -1;
}
QTAILQ_INIT(&mounts);
if (!build_fs_mount_list(&mounts, &local_err)) {
error_propagate(errp, local_err);
return -1;
}
/* cannot risk guest agent blocking itself on a write in this state */
ga_set_frozen(ga_state);
ret = qmp_guest_fsfreeze_do_freeze_list(has_mountpoints, mountpoints,
mounts, errp);
free_fs_mount_list(&mounts);
/* We may not issue any FIFREEZE here.
* Just unset ga_state here and ready for the next call.
*/
if (ret == 0) {
ga_unset_frozen(ga_state);
} else if (ret < 0) {
qmp_guest_fsfreeze_thaw(NULL);
}
return ret;
}
int64_t qmp_guest_fsfreeze_thaw(Error **errp)
{
int ret;
ret = qmp_guest_fsfreeze_do_thaw(errp);
if (ret >= 0) {
ga_unset_frozen(ga_state);
execute_fsfreeze_hook(FSFREEZE_HOOK_THAW, errp);
} else {
ret = 0;
}
return ret;
}
static void guest_fsfreeze_cleanup(void)
{
Error *err = NULL;
if (ga_is_frozen(ga_state) == GUEST_FSFREEZE_STATUS_FROZEN) {
qmp_guest_fsfreeze_thaw(&err);
if (err) {
slog("failed to clean up frozen filesystems: %s",
error_get_pretty(err));
error_free(err);
}
}
}
#endif
/* linux-specific implementations. avoid this if at all possible. */
#if defined(__linux__)
#if defined(CONFIG_FSFREEZE)
static char *get_pci_driver(char const *syspath, int pathlen, Error **errp)
@ -1467,153 +1606,6 @@ GuestFilesystemInfoList *qmp_guest_get_fsinfo(Error **errp)
free_fs_mount_list(&mounts);
return ret;
}
typedef enum {
FSFREEZE_HOOK_THAW = 0,
FSFREEZE_HOOK_FREEZE,
} FsfreezeHookArg;
static const char *fsfreeze_hook_arg_string[] = {
"thaw",
"freeze",
};
static void execute_fsfreeze_hook(FsfreezeHookArg arg, Error **errp)
{
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(errp, 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);
execl(hook, hook, arg_str, NULL);
_exit(EXIT_FAILURE);
} else if (pid < 0) {
error_setg_errno(errp, errno, "failed to create child process");
return;
}
ga_wait_child(pid, &status, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (!WIFEXITED(status)) {
error_setg(errp, "fsfreeze hook has terminated abnormally");
return;
}
status = WEXITSTATUS(status);
if (status) {
error_setg(errp, "fsfreeze hook has failed with status %d", status);
return;
}
}
/*
* Return status of freeze/thaw
*/
GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **errp)
{
if (ga_is_frozen(ga_state)) {
return GUEST_FSFREEZE_STATUS_FROZEN;
}
return GUEST_FSFREEZE_STATUS_THAWED;
}
int64_t qmp_guest_fsfreeze_freeze(Error **errp)
{
return qmp_guest_fsfreeze_freeze_list(false, NULL, errp);
}
int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
strList *mountpoints,
Error **errp)
{
int ret;
FsMountList mounts;
Error *local_err = NULL;
slog("guest-fsfreeze called");
execute_fsfreeze_hook(FSFREEZE_HOOK_FREEZE, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return -1;
}
QTAILQ_INIT(&mounts);
if (!build_fs_mount_list(&mounts, &local_err)) {
error_propagate(errp, local_err);
return -1;
}
/* cannot risk guest agent blocking itself on a write in this state */
ga_set_frozen(ga_state);
ret = qmp_guest_fsfreeze_do_freeze_list(has_mountpoints, mountpoints,
mounts, errp);
free_fs_mount_list(&mounts);
/* We may not issue any FIFREEZE here.
* Just unset ga_state here and ready for the next call.
*/
if (ret == 0) {
ga_unset_frozen(ga_state);
} else if (ret < 0) {
qmp_guest_fsfreeze_thaw(NULL);
}
return ret;
}
int64_t qmp_guest_fsfreeze_thaw(Error **errp)
{
int ret;
ret = qmp_guest_fsfreeze_do_thaw(errp);
if (ret >= 0) {
ga_unset_frozen(ga_state);
execute_fsfreeze_hook(FSFREEZE_HOOK_THAW, errp);
} else {
ret = 0;
}
return ret;
}
static void guest_fsfreeze_cleanup(void)
{
Error *err = NULL;
if (ga_is_frozen(ga_state) == GUEST_FSFREEZE_STATUS_FROZEN) {
qmp_guest_fsfreeze_thaw(&err);
if (err) {
slog("failed to clean up frozen filesystems: %s",
error_get_pretty(err));
error_free(err);
}
}
}
#endif /* CONFIG_FSFREEZE */
#if defined(CONFIG_FSTRIM)

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@ -37,12 +37,7 @@
#include "qga/service-win32.h"
#include "qga/vss-win32.h"
#endif
#ifdef __linux__
#include <linux/fs.h>
#ifdef FIFREEZE
#define CONFIG_FSFREEZE
#endif
#endif
#include "commands-common.h"
#ifndef _WIN32
#ifdef __FreeBSD__

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@ -75,6 +75,9 @@ qga_ss.add(when: 'CONFIG_POSIX', if_true: files(
qga_ss.add(when: 'CONFIG_LINUX', if_true: files(
'commands-linux.c',
))
qga_ss.add(when: 'CONFIG_BSD', if_true: files(
'commands-bsd.c',
))
qga_ss.add(when: 'CONFIG_WIN32', if_true: files(
'channel-win32.c',
'commands-win32.c',