[RESEND][BUG][PATCH]-rc: USB: yurex: add .llseek fop to file_operations

[RESEND][BUG][PATCH]-rc: USB: yurex: add .llseek fop to file_operations

[Tomoki Sekiyama]

Hi Greg-KH,
Sorry for resending this; To: was not enough.

https://bugzilla.kernel.org/show_bug.cgi?id=23512

Default llseek operation behavior was changed by the patch named
"vfs: make no_llseek the default" after the yurex driver was merged,
so the llseek to yurex is now ignored.

This patch add llseek fop with default_llseek to yurex driver
to catch up to the change.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@gmail.com>

 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c
index 719c618..ac5bfd6 100644
--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -536,6 +536,7 @@ static const struct file_operations yurex_fops = {
 	.open =		yurex_open,
 	.release =	yurex_release,
 	.fasync	=	yurex_fasync,
+	.llseek =	default_llseek,
 };


-- 
1.7.0

Re: [RESEND][BUG][PATCH]-rc: USB: yurex: add .llseek fop to file_operations

[Greg KH]

On Fri, Nov 26, 2010 at 01:11:05AM +0900, Tomoki Sekiyama wrote:
> Hi Greg-KH,
> Sorry for resending this; To: was not enough.
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=23512
> 
> Default llseek operation behavior was changed by the patch named
> "vfs: make no_llseek the default" after the yurex driver was merged,
> so the llseek to yurex is now ignored.
> 
> This patch add llseek fop with default_llseek to yurex driver
> to catch up to the change.
> 
> Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@gmail.com>

It's in my queue, sorry, been without power and water at home for a few
days, will catch up on this stuff next week...

thanks,

greg k-h

Re: [RESEND][BUG][PATCH]-rc: USB: yurex: add .llseek fop to file_operations

[Arnd Bergmann]

On Thursday 25 November 2010 18:16:13 Greg KH wrote:
> On Fri, Nov 26, 2010 at 01:11:05AM +0900, Tomoki Sekiyama wrote:
> > Hi Greg-KH,
> > Sorry for resending this; To: was not enough.
> > 
> > https://bugzilla.kernel.org/show_bug.cgi?id=23512
> > 
> > Default llseek operation behavior was changed by the patch named
> > "vfs: make no_llseek the default" after the yurex driver was merged,
> > so the llseek to yurex is now ignored.
> > 
> > This patch add llseek fop with default_llseek to yurex driver
> > to catch up to the change.
> > 
> > Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@gmail.com>
> 
> It's in my queue, sorry, been without power and water at home for a few
> days, will catch up on this stuff next week...

I was out most of the week, so I didn't get to look at it either.
Is there an actual bug here caused by having no .llseek function?

As far as I can tell, you don't really want to seek this file
anyway, so the default behaviour of disallowing llseek would actually
make more sense.

	Arnd

Re: [RESEND][BUG][PATCH]-rc: USB: yurex: add .llseek fop to file_operations

[Tomoki Sekiyama]

2010/11/27 Arnd Bergmann <arnd@arndb.de>:
> On Thursday 25 November 2010 18:16:13 Greg KH wrote:
>> On Fri, Nov 26, 2010 at 01:11:05AM +0900, Tomoki Sekiyama wrote:
>> > Hi Greg-KH,
>> > Sorry for resending this; To: was not enough.
>> >
>> > https://bugzilla.kernel.org/show_bug.cgi?id=23512
>> >
>> > Default llseek operation behavior was changed by the patch named
>> > "vfs: make no_llseek the default" after the yurex driver was merged,
>> > so the llseek to yurex is now ignored.
>> >
>> > This patch add llseek fop with default_llseek to yurex driver
>> > to catch up to the change.
>> >
>> > Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@gmail.com>
>>
>> It's in my queue, sorry, been without power and water at home for a few
>> days, will catch up on this stuff next week...
>
> I was out most of the week, so I didn't get to look at it either.
> Is there an actual bug here caused by having no .llseek function?
>
> As far as I can tell, you don't really want to seek this file
> anyway, so the default behaviour of disallowing llseek would actually
> make more sense.

I need seek because the device notifies the update of the sensor's value
by fasync, then the user can rewind(seek to 0) and re-read the file.

Thanks,
--
Tomoki Sekiyama

Re: [RESEND][BUG][PATCH]-rc: USB: yurex: add .llseek fop to file_operations

[Arnd Bergmann]

On Saturday 27 November 2010, Tomoki Sekiyama wrote:
> 2010/11/27 Arnd Bergmann <arnd@arndb.de>:
>
> > As far as I can tell, you don't really want to seek this file
> > anyway, so the default behaviour of disallowing llseek would actually
> > make more sense.
> 
> I need seek because the device notifies the update of the sensor's value
> by fasync, then the user can rewind(seek to 0) and re-read the file.

Yes, that makes sense.

Acked-by: Arnd Bergmann <arnd@arndb.de>