Hi

On 13.10.2022 14:10, Marc-André Lureau wrote:
Hi

On Thu, Oct 13, 2022 at 1:23 PM Alexander Ivanov <alexander.iva...@virtuozzo.com> wrote:

    In the next patches we are going to add FreeBSD support for QEMU Guest
    Agent. In the result, code in commands-posix.c will be too cumbersome.

    Move Linux-specific FS freeze/thaw code to a separate file
    commands-linux.c
    keeping common POSIX code in commands-posix.c.

    Reviewed-by: Konstantin Kostiuk <kkost...@redhat.com>
    Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
    Signed-off-by: Alexander Ivanov <alexander.iva...@virtuozzo.com>
    ---
     qga/commands-common.h |  35 +++++
     qga/commands-linux.c  | 286 +++++++++++++++++++++++++++++++++++++++++
     qga/commands-posix.c  | 289
    +++---------------------------------------
     qga/meson.build       |   3 +
     4 files changed, 340 insertions(+), 273 deletions(-)
     create mode 100644 qga/commands-linux.c

    diff --git a/qga/commands-common.h b/qga/commands-common.h
    index d0e4a9696f..181fc330aa 100644
    --- a/qga/commands-common.h
    +++ b/qga/commands-common.h
    @@ -10,6 +10,40 @@
     #define QGA_COMMANDS_COMMON_H

     #include "qga-qapi-types.h"
    +#include "guest-agent-core.h"
    +#include "qemu/queue.h"
    +
    +#if defined(__linux__)
    +#include <linux/fs.h>
    +#ifdef FIFREEZE
    +#define CONFIG_FSFREEZE
    +#endif
    +#ifdef FITRIM
    +#define CONFIG_FSTRIM
    +#endif
    +#endif /* __linux__ */
    +
    +#if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
    +typedef struct FsMount {
    +    char *dirname;
    +    char *devtype;
    +    unsigned int devmajor, devminor;
    +    QTAILQ_ENTRY(FsMount) next;
    +} FsMount;
    +
    +typedef QTAILQ_HEAD(FsMountList, FsMount) FsMountList;
    +
    +bool build_fs_mount_list(FsMountList *mounts, Error **errp);
    +void free_fs_mount_list(FsMountList *mounts);
    +#endif /* CONFIG_FSFREEZE || CONFIG_FSTRIM */
    +
    +#if defined(CONFIG_FSFREEZE)
    +int64_t qmp_guest_fsfreeze_do_freeze_list(bool has_mountpoints,
    +                                          strList *mountpoints,
    +                                          FsMountList mounts,
    +                                          Error **errp);
    +int qmp_guest_fsfreeze_do_thaw(Error **errp);
    +#endif /* CONFIG_FSFREEZE */

     typedef struct GuestFileHandle GuestFileHandle;

    @@ -29,4 +63,5 @@ GuestFileRead
    *guest_file_read_unsafe(GuestFileHandle *gfh,
      */
     char *qga_get_host_name(Error **errp);

    +void ga_wait_child(pid_t pid, int *status, Error **errp);


This doesn't belong here, afaict.

What do you mean, this patch or this place in the header file?

I moved this function to the global scope because it was used in commands-posix.c

and commands-linux.c in the first version of the patchset. But now we can leave

the function static in commands-posix.c. Should I do it?


     #endif
    diff --git a/qga/commands-linux.c b/qga/commands-linux.c
    new file mode 100644
    index 0000000000..214e408fcd
    --- /dev/null
    +++ b/qga/commands-linux.c
    @@ -0,0 +1,286 @@
    +/*
    + * QEMU Guest Agent Linux-specific command implementations
    + *
    + * Copyright IBM Corp. 2011
    + *
    + * Authors:
    + *  Michael Roth      <mdr...@linux.vnet.ibm.com>
    + *  Michal Privoznik  <mpriv...@redhat.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 "qapi/error.h"
    +#include "commands-common.h"
    +#include "cutils.h"
    +#include <mntent.h>
    +#include <sys/ioctl.h>
    +
    +#if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
    +static int dev_major_minor(const char *devpath,
    +                           unsigned int *devmajor, unsigned int
    *devminor)
    +{
    +    struct stat st;
    +
    +    *devmajor = 0;
    +    *devminor = 0;
    +
    +    if (stat(devpath, &st) < 0) {
    +        slog("failed to stat device file '%s': %s", devpath,
    strerror(errno));
    +        return -1;
    +    }
    +    if (S_ISDIR(st.st_mode)) {
    +        /* It is bind mount */
    +        return -2;
    +    }
    +    if (S_ISBLK(st.st_mode)) {
    +        *devmajor = major(st.st_rdev);
    +        *devminor = minor(st.st_rdev);
    +        return 0;
    +    }
    +    return -1;
    +}
    +
    +static bool build_fs_mount_list_from_mtab(FsMountList *mounts,
    Error **errp)
    +{
    +    struct mntent *ment;
    +    FsMount *mount;
    +    char const *mtab = "/proc/self/mounts";
    +    FILE *fp;
    +    unsigned int devmajor, devminor;
    +
    +    fp = setmntent(mtab, "r");
    +    if (!fp) {
    +        error_setg(errp, "failed to open mtab file: '%s'", mtab);
    +        return false;
    +    }
    +
    +    while ((ment = getmntent(fp))) {
    +        /*
    +         * An entry which device name doesn't start with a '/' is
    +         * either a dummy file system or a network file system.
    +         * Add special handling for smbfs and cifs as is done by
    +         * coreutils as well.
    +         */
    +        if ((ment->mnt_fsname[0] != '/') ||
    +            (strcmp(ment->mnt_type, "smbfs") == 0) ||
    +            (strcmp(ment->mnt_type, "cifs") == 0)) {
    +            continue;
    +        }
    +        if (dev_major_minor(ment->mnt_fsname, &devmajor,
    &devminor) == -2) {
    +            /* Skip bind mounts */
    +            continue;
    +        }
    +
    +        mount = g_new0(FsMount, 1);
    +        mount->dirname = g_strdup(ment->mnt_dir);
    +        mount->devtype = g_strdup(ment->mnt_type);
    +        mount->devmajor = devmajor;
    +        mount->devminor = devminor;
    +
    +        QTAILQ_INSERT_TAIL(mounts, mount, next);
    +    }
    +
    +    endmntent(fp);
    +    return true;
    +}
    +
    +static void decode_mntname(char *name, int len)
    +{
    +    int i, j = 0;
    +    for (i = 0; i <= len; i++) {
    +        if (name[i] != '\\') {
    +            name[j++] = name[i];
    +        } else if (name[i + 1] == '\\') {
    +            name[j++] = '\\';
    +            i++;
    +        } else if (name[i + 1] >= '0' && name[i + 1] <= '3' &&
    +                   name[i + 2] >= '0' && name[i + 2] <= '7' &&
    +                   name[i + 3] >= '0' && name[i + 3] <= '7') {
    +            name[j++] = (name[i + 1] - '0') * 64 +
    +                        (name[i + 2] - '0') * 8 +
    +                        (name[i + 3] - '0');
    +            i += 3;
    +        } else {
    +            name[j++] = name[i];
    +        }
    +    }
    +}
    +
    +/*
    + * Walk the mount table and build a list of local file systems
    + */
    +bool build_fs_mount_list(FsMountList *mounts, Error **errp)
    +{
    +    FsMount *mount;
    +    char const *mountinfo = "/proc/self/mountinfo";
    +    FILE *fp;
    +    char *line = NULL, *dash;
    +    size_t n;
    +    char check;
    +    unsigned int devmajor, devminor;
    +    int ret, dir_s, dir_e, type_s, type_e, dev_s, dev_e;
    +
    +    fp = fopen(mountinfo, "r");
    +    if (!fp) {
    +        return build_fs_mount_list_from_mtab(mounts, errp);
    +    }
    +
    +    while (getline(&line, &n, fp) != -1) {
    +        ret = sscanf(line, "%*u %*u %u:%u %*s %n%*s%n%c",
    +                     &devmajor, &devminor, &dir_s, &dir_e, &check);
    +        if (ret < 3) {
    +            continue;
    +        }
    +        dash = strstr(line + dir_e, " - ");
    +        if (!dash) {
    +            continue;
    +        }
    +        ret = sscanf(dash, " - %n%*s%n %n%*s%n%c",
    +                     &type_s, &type_e, &dev_s, &dev_e, &check);
    +        if (ret < 1) {
    +            continue;
    +        }
    +        line[dir_e] = 0;
    +        dash[type_e] = 0;
    +        dash[dev_e] = 0;
    +        decode_mntname(line + dir_s, dir_e - dir_s);
    +        decode_mntname(dash + dev_s, dev_e - dev_s);
    +        if (devmajor == 0) {
    +            /* btrfs reports major number = 0 */
    +            if (strcmp("btrfs", dash + type_s) != 0 ||
    +                dev_major_minor(dash + dev_s, &devmajor,
    &devminor) < 0) {
    +                continue;
    +            }
    +        }
    +
    +        mount = g_new0(FsMount, 1);
    +        mount->dirname = g_strdup(line + dir_s);
    +        mount->devtype = g_strdup(dash + type_s);
    +        mount->devmajor = devmajor;
    +        mount->devminor = devminor;
    +
    +        QTAILQ_INSERT_TAIL(mounts, mount, next);
    +    }
    +    free(line);
    +
    +    fclose(fp);
    +    return true;
    +}
    +#endif /* CONFIG_FSFREEZE || CONFIG_FSTRIM */
    +
    +#ifdef CONFIG_FSFREEZE
    +/*
    + * Walk list of mounted file systems in the guest, and freeze the
    ones which
    + * are real local file systems.
    + */
    +int64_t qmp_guest_fsfreeze_do_freeze_list(bool has_mountpoints,
    +                                          strList *mountpoints,
    +                                          FsMountList mounts,
    +                                          Error **errp)
    +{
    +    struct FsMount *mount;
    +    strList *list;
    +    int fd, ret, i = 0;
    +
    +    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) {
    +                    break;
    +                }
    +            }
    +            if (!list) {
    +                continue;
    +            }
    +        }
    +
    +        fd = qga_open_cloexec(mount->dirname, O_RDONLY, 0);
    +        if (fd == -1) {
    +            error_setg_errno(errp, errno, "failed to open %s",
    mount->dirname);
    +            return -1;
    +        }
    +
    +        /* we try to cull filesystems we know won't work in
    advance, but other
    +         * filesystems may not implement fsfreeze for less
    obvious reasons.
    +         * these will report EOPNOTSUPP. we simply ignore these
    when tallying
    +         * the number of frozen filesystems.
    +         * if a filesystem is mounted more than once (aka bind
    mount) a
    +         * consecutive attempt to freeze an already frozen
    filesystem will
    +         * return EBUSY.
    +         *
    +         * 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 == -1) {
    +            if (errno != EOPNOTSUPP && errno != EBUSY) {
    +                error_setg_errno(errp, errno, "failed to freeze %s",
    +                                 mount->dirname);
    +                close(fd);
    +                return -1;
    +            }
    +        } else {
    +            i++;
    +        }
    +        close(fd);
    +    }
    +    return i;
    +}
    +
    +int qmp_guest_fsfreeze_do_thaw(Error **errp)
    +{
    +    int ret;
    +    FsMountList mounts;
    +    FsMount *mount;
    +    int fd, i = 0, logged;
    +    Error *local_err = NULL;
    +
    +    QTAILQ_INIT(&mounts);
    +    if (!build_fs_mount_list(&mounts, &local_err)) {
    +        error_propagate(errp, local_err);
    +        return -1;
    +    }
    +
    +    QTAILQ_FOREACH(mount, &mounts, next) {
    +        logged = false;
    +        fd = qga_open_cloexec(mount->dirname, O_RDONLY, 0);
    +        if (fd == -1) {
    +            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 preceding 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);
    +    }
    +
    +    free_fs_mount_list(&mounts);
    +
    +    return i;
    +}
    +#endif /* CONFIG_FSFREEZE */
    diff --git a/qga/commands-posix.c b/qga/commands-posix.c
    index 16d67e9f6d..9574b83c92 100644
    --- a/qga/commands-posix.c
    +++ b/qga/commands-posix.c
    @@ -16,11 +16,9 @@
     #include <sys/utsname.h>
     #include <sys/wait.h>
     #include <dirent.h>
    -#include "guest-agent-core.h"
     #include "qga-qapi-commands.h"
     #include "qapi/error.h"
     #include "qapi/qmp/qerror.h"
    -#include "qemu/queue.h"
     #include "qemu/host-utils.h"
     #include "qemu/sockets.h"
     #include "qemu/base64.h"
    @@ -70,7 +68,7 @@
     #endif
     #endif

    -static void ga_wait_child(pid_t pid, int *status, Error **errp)
    +void ga_wait_child(pid_t pid, int *status, Error **errp)
     {
         pid_t rpid;

    @@ -629,16 +627,7 @@ void qmp_guest_file_flush(int64_t handle,
    Error **errp)
     #if defined(__linux__)

     #if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
    -typedef struct FsMount {
    -    char *dirname;
    -    char *devtype;
    -    unsigned int devmajor, devminor;
    -    QTAILQ_ENTRY(FsMount) next;
    -} FsMount;
    -
    -typedef QTAILQ_HEAD(FsMountList, FsMount) FsMountList;
    -
    -static void free_fs_mount_list(FsMountList *mounts)
    +void free_fs_mount_list(FsMountList *mounts)
     {
          FsMount *mount, *temp;

    @@ -653,157 +642,6 @@ static void free_fs_mount_list(FsMountList
    *mounts)
              g_free(mount);
          }
     }
    -
    -static int dev_major_minor(const char *devpath,
    -                           unsigned int *devmajor, unsigned int
    *devminor)
    -{
    -    struct stat st;
    -
    -    *devmajor = 0;
    -    *devminor = 0;
    -
    -    if (stat(devpath, &st) < 0) {
    -        slog("failed to stat device file '%s': %s", devpath,
    strerror(errno));
    -        return -1;
    -    }
    -    if (S_ISDIR(st.st_mode)) {
    -        /* It is bind mount */
    -        return -2;
    -    }
    -    if (S_ISBLK(st.st_mode)) {
    -        *devmajor = major(st.st_rdev);
    -        *devminor = minor(st.st_rdev);
    -        return 0;
    -    }
    -    return -1;
    -}
    -
    -/*
    - * Walk the mount table and build a list of local file systems
    - */
    -static bool build_fs_mount_list_from_mtab(FsMountList *mounts,
    Error **errp)
    -{
    -    struct mntent *ment;
    -    FsMount *mount;
    -    char const *mtab = "/proc/self/mounts";
    -    FILE *fp;
    -    unsigned int devmajor, devminor;
    -
    -    fp = setmntent(mtab, "r");
    -    if (!fp) {
    -        error_setg(errp, "failed to open mtab file: '%s'", mtab);
    -        return false;
    -    }
    -
    -    while ((ment = getmntent(fp))) {
    -        /*
    -         * An entry which device name doesn't start with a '/' is
    -         * either a dummy file system or a network file system.
    -         * Add special handling for smbfs and cifs as is done by
    -         * coreutils as well.
    -         */
    -        if ((ment->mnt_fsname[0] != '/') ||
    -            (strcmp(ment->mnt_type, "smbfs") == 0) ||
    -            (strcmp(ment->mnt_type, "cifs") == 0)) {
    -            continue;
    -        }
    -        if (dev_major_minor(ment->mnt_fsname, &devmajor,
    &devminor) == -2) {
    -            /* Skip bind mounts */
    -            continue;
    -        }
    -
    -        mount = g_new0(FsMount, 1);
    -        mount->dirname = g_strdup(ment->mnt_dir);
    -        mount->devtype = g_strdup(ment->mnt_type);
    -        mount->devmajor = devmajor;
    -        mount->devminor = devminor;
    -
    -        QTAILQ_INSERT_TAIL(mounts, mount, next);
    -    }
    -
    -    endmntent(fp);
    -    return true;
    -}
    -
    -static void decode_mntname(char *name, int len)
    -{
    -    int i, j = 0;
    -    for (i = 0; i <= len; i++) {
    -        if (name[i] != '\\') {
    -            name[j++] = name[i];
    -        } else if (name[i + 1] == '\\') {
    -            name[j++] = '\\';
    -            i++;
    -        } else if (name[i + 1] >= '0' && name[i + 1] <= '3' &&
    -                   name[i + 2] >= '0' && name[i + 2] <= '7' &&
    -                   name[i + 3] >= '0' && name[i + 3] <= '7') {
    -            name[j++] = (name[i + 1] - '0') * 64 +
    -                        (name[i + 2] - '0') * 8 +
    -                        (name[i + 3] - '0');
    -            i += 3;
    -        } else {
    -            name[j++] = name[i];
    -        }
    -    }
    -}
    -
    -static bool build_fs_mount_list(FsMountList *mounts, Error **errp)
    -{
    -    FsMount *mount;
    -    char const *mountinfo = "/proc/self/mountinfo";
    -    FILE *fp;
    -    char *line = NULL, *dash;
    -    size_t n;
    -    char check;
    -    unsigned int devmajor, devminor;
    -    int ret, dir_s, dir_e, type_s, type_e, dev_s, dev_e;
    -
    -    fp = fopen(mountinfo, "r");
    -    if (!fp) {
    -        return build_fs_mount_list_from_mtab(mounts, errp);
    -    }
    -
    -    while (getline(&line, &n, fp) != -1) {
    -        ret = sscanf(line, "%*u %*u %u:%u %*s %n%*s%n%c",
    -                     &devmajor, &devminor, &dir_s, &dir_e, &check);
    -        if (ret < 3) {
    -            continue;
    -        }
    -        dash = strstr(line + dir_e, " - ");
    -        if (!dash) {
    -            continue;
    -        }
    -        ret = sscanf(dash, " - %n%*s%n %n%*s%n%c",
    -                     &type_s, &type_e, &dev_s, &dev_e, &check);
    -        if (ret < 1) {
    -            continue;
    -        }
    -        line[dir_e] = 0;
    -        dash[type_e] = 0;
    -        dash[dev_e] = 0;
    -        decode_mntname(line + dir_s, dir_e - dir_s);
    -        decode_mntname(dash + dev_s, dev_e - dev_s);
    -        if (devmajor == 0) {
    -            /* btrfs reports major number = 0 */
    -            if (strcmp("btrfs", dash + type_s) != 0 ||
    -                dev_major_minor(dash + dev_s, &devmajor,
    &devminor) < 0) {
    -                continue;
    -            }
    -        }
    -
    -        mount = g_new0(FsMount, 1);
    -        mount->dirname = g_strdup(line + dir_s);
    -        mount->devtype = g_strdup(dash + type_s);
    -        mount->devmajor = devmajor;
    -        mount->devminor = devminor;
    -
    -        QTAILQ_INSERT_TAIL(mounts, mount, next);
    -    }
    -    free(line);
    -
    -    fclose(fp);
    -    return true;
    -}
     #endif

     #if defined(CONFIG_FSFREEZE)
    @@ -1708,20 +1546,13 @@ int64_t qmp_guest_fsfreeze_freeze(Error
    **errp)
         return qmp_guest_fsfreeze_freeze_list(false, NULL, errp);
     }

    -/*
    - * Walk list of mounted file systems in the guest, and freeze the
    ones which
    - * are real local file systems.
    - */
     int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
                                            strList *mountpoints,
                                            Error **errp)
     {
    -    int ret = 0, i = 0;
    -    strList *list;
    +    int ret;
         FsMountList mounts;
    -    struct FsMount *mount;
         Error *local_err = NULL;
    -    int fd;

         slog("guest-fsfreeze called");

    @@ -1740,122 +1571,34 @@ int64_t
    qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
         /* cannot risk guest agent blocking itself on a write in this
    state */
         ga_set_frozen(ga_state);

    -    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) {
    -                    break;
    -                }
    -            }
    -            if (!list) {
    -                continue;
    -            }
    -        }
    -
    -        fd = qga_open_cloexec(mount->dirname, O_RDONLY, 0);
    -        if (fd == -1) {
    -            error_setg_errno(errp, errno, "failed to open %s",
    mount->dirname);
    -            goto error;
    -        }
    -
    -        /* we try to cull filesystems we know won't work in
    advance, but other
    -         * filesystems may not implement fsfreeze for less
    obvious reasons.
    -         * these will report EOPNOTSUPP. we simply ignore these
    when tallying
    -         * the number of frozen filesystems.
    -         * if a filesystem is mounted more than once (aka bind
    mount) a
    -         * consecutive attempt to freeze an already frozen
    filesystem will
    -         * return EBUSY.
    -         *
    -         * 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 == -1) {
    -            if (errno != EOPNOTSUPP && errno != EBUSY) {
    -                error_setg_errno(errp, errno, "failed to freeze %s",
    -                                 mount->dirname);
    -                close(fd);
    -                goto error;
    -            }
    -        } else {
    -            i++;
    -        }
    -        close(fd);
    -    }
    +    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 (i == 0) {
    +    if (ret == 0) {
             ga_unset_frozen(ga_state);
    +    } else if (ret < 0) {
    +        qmp_guest_fsfreeze_thaw(NULL);
         }
    -    return i;
    -
    -error:
    -    free_fs_mount_list(&mounts);
    -    qmp_guest_fsfreeze_thaw(NULL);
    -    return 0;
    +    return ret;
     }

    -/*
    - * Walk list of frozen file systems in the guest, and thaw them.
    - */
     int64_t qmp_guest_fsfreeze_thaw(Error **errp)
     {
         int ret;
    -    FsMountList mounts;
    -    FsMount *mount;
    -    int fd, i = 0, logged;
    -    Error *local_err = NULL;

    -    QTAILQ_INIT(&mounts);
    -    if (!build_fs_mount_list(&mounts, &local_err)) {
    -        error_propagate(errp, local_err);
    -        return 0;
    +    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;
         }

    -    QTAILQ_FOREACH(mount, &mounts, next) {
    -        logged = false;
    -        fd = qga_open_cloexec(mount->dirname, O_RDONLY, 0);
    -        if (fd == -1) {
    -            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 preceding 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);
    -    }
    -
    -    ga_unset_frozen(ga_state);
    -    free_fs_mount_list(&mounts);
    -
    -    execute_fsfreeze_hook(FSFREEZE_HOOK_THAW, errp);
    -
    -    return i;
    +    return ret;
     }

     static void guest_fsfreeze_cleanup(void)
    diff --git a/qga/meson.build b/qga/meson.build
    index a0ffd6d268..932b4e7ca8 100644
    --- a/qga/meson.build
    +++ b/qga/meson.build
    @@ -72,6 +72,9 @@ qga_ss.add(when: 'CONFIG_POSIX', if_true: files(
       'commands-posix.c',
       'commands-posix-ssh.c',
     ))
    +qga_ss.add(when: 'CONFIG_LINUX', if_true: files(
    +  'commands-linux.c',
    +))
     qga_ss.add(when: 'CONFIG_WIN32', if_true: files(
       'channel-win32.c',
       'commands-win32.c',
-- 2.34.1



--
Marc-André Lureau

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