Re: [Gluster-devel] [PATCH 3/3 v4] vfs_glusterfs: Samba VFS module for glusterfs

[Andrew Bartlett]

Sorry for not finding this before, but I just noticed this: 

On Thu, 2013-05-23 at 22:30 -0400, Anand Avati wrote:
> static char *vfs_gluster_getwd(struct vfs_handle_struct *handle)
> +{
> +       char *cwd;
> +       char *ret;
> +
> +       cwd = TALLOC_ZERO(NULL, PATH_MAX+1);
> +       if (!cwd)
> +               return NULL;
> +
> +       ret = glfs_getcwd(handle->data, cwd, PATH_MAX);
> +       if (!ret)
> +               TALLOC_FREE(cwd);
> +       return ret;
> +} 

While you would expect that getwd would return a talloc-based result, it
doesn't actually:

The other userspace filesystem ceph does:

static char *cephwrap_getwd(struct vfs_handle_struct *handle)
{
        const char *cwd = ceph_getcwd(handle->data);
        DEBUG(10, ("[CEPH] getwd(%p) = %s\n", handle, cwd));
        return SMB_STRDUP(cwd);
}

vfs_default does:

static char *vfswrap_getwd(vfs_handle_struct *handle)
{
        char *result;

        START_PROFILE(syscall_getwd);
        result = sys_getwd();
        END_PROFILE(syscall_getwd);
        return result;
}

(and sys_getwd() in system.c is malloc based).

The best fix would be to convert the callers and VFS API to use talloc
(and pass in a talloc context).  There are only two, in
source3/smbd/vfs.c:vfs_GetWd(), and
source3/torture/cmd_vfs.c:cmd_getwd().  The former really wants a talloc
result anyway!

Andrew Bartlett

-- 
Andrew Bartlett                                http://samba.org/~abartlet/
Authentication Developer, Samba Team           http://samba.org