Re: [libvirt] [PATCH] Fix domain restore for files on root-squash NFS.
On 02/24/2010 06:20 AM, Laine Stump wrote:
> ...since I see nothing in POSIX that guarantees that pipe() will
preserve
> your initialized values across failure. I think it's better to
> explicitly
> set things to -1 on the failure path, rather than initializing that way.
Interesting point. If we can't rely on that, then __virExec() should be
changed too.
Since libvirtd is Linux-only, we can luckily rely on that at least for now:
int do_pipe_flags(int *fd, int flags)
{
struct file *fw, *fr;
int error;
int fdw, fdr;
if (flags & ~(O_CLOEXEC | O_NONBLOCK))
return -EINVAL;
fw = create_write_pipe(flags);
if (IS_ERR(fw))
return PTR_ERR(fw);
fr = create_read_pipe(fw, flags);
error = PTR_ERR(fr);
if (IS_ERR(fr))
goto err_write_pipe;
error = get_unused_fd_flags(flags);
if (error < 0)
goto err_read_pipe;
fdr = error;
error = get_unused_fd_flags(flags);
if (error < 0)
goto err_fdr;
fdw = error;
audit_fd_pair(fdr, fdw);
fd_install(fdr, fr);
fd_install(fdw, fw);
fd[0] = fdr;
fd[1] = fdw;
return 0;
err_fdr:
put_unused_fd(fdr);
err_read_pipe:
path_put(&fr->f_path);
put_filp(fr);
err_write_pipe:
free_write_pipe(fw);
return error;
}
which makes it quite low priority.
Paolo