On Tue, 5 Jul 2016, Mark Hounschell wrote:
> From: Jiri Kosina <jkos...@suse.cz>
>
> Commit 09954bad4 ("floppy: refactor open() flags handling"), as a
> side-effect, causes open(/dev/fdX, O_ACCMODE) to fail. It turns out that
> this is being used setfdprm userspace for ioctl-only open().
>
> Reintroduce back the original behavior wrt !(FMODE_READ|FMODE_WRITE)
> modes, while still keeping the original O_NDELAY bug fixed.
>
> Cc: sta...@vger.kernel.org # v4.5+
> Reported-by: Wim Osterholt <w...@djo.tudelft.nl>
> Tested-by: Wim Osterholt <w...@djo.tudelft.nl>
> Signed-off-by: Jiri Kosina <jkos...@suse.cz>
> ---
[ ... snip ... ]
>
> But this does not completely fix all the problems induced by the original
> changes from 4.4 to 4.5. The following is what we use to open the floppy.
>
> fd = open(device, O_RDWR | O_NDELAY);
>
> The FMODE_NDELAY check that was removed now prevents one from doing an open of
> the device with no media inserted. It also prevents one from doing an open of
> the device with media inserted that is not already formatted in a "standard"
> format. I do both of these things a lot. I deal with a few very non-standard
> formats and this change prevents me from doing what I've been doing for YEARS.
> Could we please get the original behavior back in the floppy driver.
Hi Mark,
thanks for the regression report.
For my better understanding of your issue -- what behavior/semantics
exactly does your userspace think it'll be getting from opening /dev/fd0
with O_NDELAY?
Thanks,
--
Jiri Kosina
SUSE Labs
