On 02/01/11 15:48, Adam Litke wrote:
> On Tue, 2011-02-01 at 11:58 +0100, jes.soren...@redhat.com wrote:
>> +/*
>> + * va_fsfreeze(): Walk list of mounted file systems in the guest, and
>> + * freeze the ones which are real local file systems.
>> + * rpc return values: Number of file systems frozen, -1 on error.
>> + */
>> +static xmlrpc_value *va_fsfreeze(xmlrpc_env *env,
>> + xmlrpc_value *params,
>> + void *user_data)
>> +{
>> + xmlrpc_int32 ret = 0, i = 0;
>> + xmlrpc_value *result;
>> + struct direntry *entry;
>> + int fd;
>> + SLOG("va_fsfreeze()");
>> +
>> + if (fsfreeze_status == FREEZE_FROZEN) {
>> + ret = 0;
>> + goto out;
>> + }
>> +
>> + ret = build_mount_list();
>> + if (ret < 0) {
>> + goto out;
>> + }
>> +
>> + fsfreeze_status = FREEZE_INPROGRESS;
>> +
>> + entry = mount_list;
>> + while(entry) {
>> + fd = qemu_open(entry->dirname, O_RDONLY);
>> + if (fd == -1) {
>> + ret = errno;
>> + goto error;
>> + }
>> + ret = ioctl(fd, FIFREEZE);
>> + if (ret < 0 && ret != EOPNOTSUPP) {
>> + goto error;
>> + }
>
> Here we silently ignore filesystems that do not support the FIFREEZE
> ioctl. Do we need to have a more complex return value so that we can
> communicate which mount points could not be frozen? Otherwise, an
> unsuspecting host could retrieve a corrupted snapshot of that
> filesystem, right?
That is correct, however most Linux file systems do support it, and for
the ones that don't, there really isn't anything we can do.
Cheers,
Jes
