On Thu, Sep 29, 2022 at 12:04 PM Alexander Ivanov <
alexander.iva...@virtuozzo.com> wrote:
> 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.
>
> Signed-off-by: Alexander Ivanov <alexander.iva...@virtuozzo.com>
>
lgtm,
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> qga/commands-bsd.c | 169 +++++++++++++++++++++++
> qga/commands-common.h | 11 ++
> qga/commands-posix.c | 308 ++++++++++++++++++++----------------------
> qga/main.c | 7 +-
> qga/meson.build | 3 +
> 5 files changed, 334 insertions(+), 164 deletions(-)
> create mode 100644 qga/commands-bsd.c
>
> diff --git a/qga/commands-bsd.c b/qga/commands-bsd.c
> new file mode 100644
> index 0000000000..ca06692179
> --- /dev/null
> +++ b/qga/commands-bsd.c
> @@ -0,0 +1,169 @@
> +/*
> + * QEMU Guest Agent BSD-specific command implementations
> + *
> + * Copyright (c) Virtuozzo International GmbH.
> + *
> + * Authors:
> + * Alexander Ivanov <alexander.iva...@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 */
> diff --git a/qga/commands-common.h b/qga/commands-common.h
> index 181fc330aa..2d9878a634 100644
> --- a/qga/commands-common.h
> +++ b/qga/commands-common.h
> @@ -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;
>
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index 9574b83c92..49f9996a9c 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -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)
> diff --git a/qga/main.c b/qga/main.c
> index 0d27c97d38..b3580508fa 100644
> --- a/qga/main.c
> +++ b/qga/main.c
> @@ -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__
> diff --git a/qga/meson.build b/qga/meson.build
> index 409f49a000..456ba4c29f 100644
> --- a/qga/meson.build
> +++ b/qga/meson.build
> @@ -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',
> --
> 2.34.1
>
>
>
--
Marc-André Lureau
