Re: [PATCH 3.14 15/76] USB: uas: Reduce can_queue to MAX_CMNDS

[Greg Kroah-Hartman]

On Mon, Apr 11, 2016 at 01:52:32PM +0200, Jiri Slaby wrote:
> On 04/10/2016, 08:36 PM, Greg Kroah-Hartman wrote:
> > 3.14-stable review patch.  If anyone has any objections, please let me know.
> > 
> > ------------------
> > 
> > From: Hans de Goede <hdegoede@xxxxxxxxxx>
> > 
> > commit 55ff8cfbc4e12a7d2187df523938cc671fbebdd1 upstream.
> > 
> > The uas driver can never queue more then MAX_CMNDS (- 1) tags and tags
> > are shared between luns, so there is no need to claim that we can_queue
> > some random large number.
> > 
> > Not claiming that we can_queue 65536 commands, fixes the uas driver
> > failing to initialize while allocating the tag map with a "Page allocation
> > failure (order 7)" error on systems which have been running for a while
> > and thus have fragmented memory.
> > 
> > Reported-and-tested-by: Yves-Alexis Perez <corsac@xxxxxxxxxx>
> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > 
> > ---
> >  drivers/usb/storage/uas.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > --- a/drivers/usb/storage/uas.c
> > +++ b/drivers/usb/storage/uas.c
> > @@ -835,7 +835,7 @@ static struct scsi_host_template uas_hos
> >  	.eh_abort_handler = uas_eh_abort_handler,
> >  	.eh_device_reset_handler = uas_eh_device_reset_handler,
> >  	.eh_bus_reset_handler = uas_eh_bus_reset_handler,
> > -	.can_queue = 65536,	/* Is there a limit on the _host_ ? */
> > +	.can_queue = MAX_CMNDS,
> 
> MAX_CMNDS is defined only since 3.18. (The driver is marked as BROKEN
> till 3.15, anyway.)

Ah, good point, now removed, thanks.

greg k-h