Hi
On Thu, Sep 22, 2022 at 4:15 PM Alexander Ivanov <
alexander.iva...@virtuozzo.com> wrote:
> UFS supports FS freezing through ioctl UFSSUSPEND on /dev/ufssuspend.
> Freezed 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>
> ---
> qga/commands-bsd.c | 109 +++++++++++++++++++++++++++++++++++++++---
> qga/commands-common.h | 11 +++++
> qga/main.c | 6 +++
> 3 files changed, 120 insertions(+), 6 deletions(-)
>
> diff --git a/qga/commands-bsd.c b/qga/commands-bsd.c
> index c1e3ed13e9..5d3f46804a 100644
> --- a/qga/commands-bsd.c
> +++ b/qga/commands-bsd.c
> @@ -17,28 +17,125 @@
> #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)
> {
> - error_setg(errp, QERR_UNSUPPORTED);
> - return false;
> + 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) {
>
I am not sure we can simply ignore an error here. At least, there should be
a warning logged, no?
> + continue;
> + }
> +
> + 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
>
> #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)
> {
> - error_setg(errp, QERR_UNSUPPORTED);
> - return 0;
> + 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 (strcmp(list->value, mount->dirname) == 0) {
>
nit: I prefer g_str_equal()
> + break;
> + }
> + }
> + if (!list) {
> + continue;
> + }
> + }
> +
> + /* Only UFS supports suspend */
> + if (strcmp(mount->devtype, "ufs") != 0) {
>
!g_str_equal()
> + 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;
> +
> }
>
> int qmp_guest_fsfreeze_do_thaw(Error **errp)
> {
> - error_setg(errp, QERR_UNSUPPORTED);
> - return 0;
> + int ret = ufssuspend_cnt;
> + ufssuspend_cnt = 0;
> + if (ufssuspend_fd != -1) {
> + close(ufssuspend_fd);
> + ufssuspend_fd = -1;
> + }
>
Maybe leave a comment that UFSRESUME isn't necessary?
> + return ret;
> }
> #endif
>
> diff --git a/qga/commands-common.h b/qga/commands-common.h
> index aa0472ea4c..c3be6db3a9 100644
> --- a/qga/commands-common.h
> +++ b/qga/commands-common.h
> @@ -41,11 +41,22 @@ void ga_wait_child(pid_t pid, int *status, Error
> **errp);
> #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/main.c b/qga/main.c
> index 22b3c0df11..ab420051fb 100644
> --- a/qga/main.c
> +++ b/qga/main.c
> @@ -43,6 +43,12 @@
> #define CONFIG_FSFREEZE
> #endif
> #endif
> +#ifdef __FreeBSD__
> +#include <ufs/ffs/fs.h>
> +#ifdef UFSSUSPEND
> +#define CONFIG_FSFREEZE
> +#endif
> +#endif
>
> #ifndef _WIN32
> #ifdef __FreeBSD__
> --
> 2.34.1
>
>
>
--
Marc-André Lureau
