On 17/08/10 12:18, Richard W.M. Jones wrote:
On Wed, Aug 04, 2010 at 04:14:45PM +0100, Matthew Booth wrote:
> When fetching a storage volume over SSH, we were detecting its size with a
> simple 'stat -c %s'. While this works fine for files, it won't return
the
> correct size of a block device.
>
> This patch uses the output of 'blockdev --getsize64' for block devices, and
stat
> as before for regular files.
>
> Fixes RHBZ#620698
> ---
> lib/Sys/VirtV2V/Transfer/SSH.pm | 16 +++++++++++++++-
> 1 files changed, 15 insertions(+), 1 deletions(-)
>
> diff --git a/lib/Sys/VirtV2V/Transfer/SSH.pm b/lib/Sys/VirtV2V/Transfer/SSH.pm
> index 66ec294..5f54f0e 100644
> --- a/lib/Sys/VirtV2V/Transfer/SSH.pm
> +++ b/lib/Sys/VirtV2V/Transfer/SSH.pm
> @@ -138,7 +138,21 @@ sub _connect
> push(@command, 'ssh');
> push(@command, '-l', $username) if (defined($username));
> push(@command, $host);
> - push(@command, "stat -c %s $path; cat $path");
> +
> + # Return the size of the remote path on the first line, followed by its
> + # contents.
> + # The bit arithmetic with the output of stat is a translation into shell
> + # of the S_ISBLK macro. If the remote device is a block device, stat
> + # will simply return the size of the block device inode. In this case,
> + # we use the output of blockdev --getsize64 instead.
> + push(@command,
> + "dev=$path; ".
> + 'if [[ $(((0x$(stat -L -c %f $dev)&0170000)>>12)) == 6 ]];
then '.
> + 'blockdev --getsize64 $dev; '.
> + 'else '.
> + 'stat -L -c %s $dev; '.
> + 'fi; '.
> + 'cat $dev');
>
> # Close the ends of the pipes we don't need
> close($stdin_write);
Yikes.
Not an easier way to ask if a filename is a block device? Like
maybe: test -b $dev
I've actually already pushed this, but I'll update it anyway. Thanks :)
Matt
--
Matthew Booth, RHCA, RHCSS
Red Hat Engineering, Virtualisation Team
GPG ID: D33C3490
GPG FPR: 3733 612D 2D05 5458 8A8A 1600 3441 EA19 D33C 3490