ufs freeze does not work

[Hongjiang Zhang]

Hi all,

I wrote a test to freeze ufs, but it does not work even if the ioctl returns successful. What is the problem?

#define _PATH_UFSSUSPEND        "/dev/ufssuspend"
static void freeze_allmountpoints()
{
        struct statfs *mntbuf, *statfsp;
        int mntsize;
        int fso;
        int error;
        int i;
        fso = open(_PATH_UFSSUSPEND, O_RDWR);
        if (fso == -1)
                err(1, "unable to open %s", _PATH_UFSSUSPEND);
        /*
         * First check the mounted filesystems.
         */
        mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
        if (mntsize == 0)
                return;

        printf("mnt size: %d\n", mntsize);
        for(i = mntsize - 1; i >= 0; --i)
        {
                statfsp = &mntbuf[i];

                if (strcmp("/", statfsp->f_mntonname) == 0 ||
                        strcmp("ufs", statfsp->f_fstypename) == 0)
                {
                        printf("begin to suspend on '%s' from '%s'\n",
                                statfsp->f_mntonname, statfsp->f_mntfromname);

                        error = ioctl(fso, UFSSUSPEND, &statfsp->f_fsid);
                        if (error != 0) {
                                //err(1, "UFSSUSPEND");
                                printf("error: %d\n",errno);
                       } else {
                                printf("Successfully suspend filesystem\n");
                        }
                        break;
                }
        }
        close(fso);
}

Thanks
Hongjiang Zhang