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

[Jiri Slaby]

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.)

thanks,
-- 
js
suse labs