Re: [PATCH v4 2/2] efi: an sysfs interface for user to update efi firmware

Andy Lutomirski
2015-04-22T03:25:13Z

On Tue, Apr 21, 2015 at 7:20 PM, James Bottomley
<James.Bottomley@hansenpartnership.com> wrote:
> On Tue, 2015-04-21 at 18:58 -0700, Andy Lutomirski wrote:
>> On Tue, Apr 21, 2015 at 6:21 PM, James Bottomley
>> <James.Bottomley@hansenpartnership.com> wrote:
>> > Andy, just on the misc device idea, what about triggering the capsule
>> > update from close()? In theory close returns an error code (not sure if
>> > most tools actually check this, though). That means we can do the write
>> > in chunks but pass it in atomically on the close and cat will work
>> > (provided it checks the return code of close).
>>
>> I thought about this but IIRC cat doesn't check the return value from close.
>
> It does in my copy (coreutils-8.23) :
>
> if (!STREQ (infile, "-") && close (input_desc) < 0)
> {
> error (0, errno, "%s", infile);
> ok = false;
> }
> [...]
> if (have_read_stdin && close (STDIN_FILENO) < 0)
> error (EXIT_FAILURE, errno, _("closing standard input"));
>

True, but it's stdout that we care about, not stdin :(

--Andy

>
> James
>
>

--
Andy Lutomirski
AMA Capital Management, LLC