This patch adds recovery from false busy state on concurrent attach
operation.
The procedure of attach operation is as below.
1) Find an unused port in /sys/devices/platform/vhci_hcd/status.
(userspace)
2) Request attach found port to driver through
/sys/devices/platform/vhci_hcd/attach. (userspace)
3) Lock table, reserve requested port and unlock table. (vhci driver)
Attaching more than one remote devices concurrently, same unused port
number will be found in step-1. Then one request will succeed and
others will fail even though there are some unused ports.
With this patch, driver returns EBUSY when requested port has already
been used. In this case, attach command retries from step-1: finding
another unused port. If there's no unused port, the attach operation
will fail in step-1. Otherwise it retries automatically using another
unused port.
vhci-hcd's interface (only errno) is changed as following.
Current errno New errno Condition
EINVAL same as left specified port number is in invalid
range
EAGAIN same as left platform_get_drvdata() failed
EINVAL same as left specified socket fd is not valid
EINVAL EBUSY specified port status is not free
The errno EBUSY was not used in userspace
src/usbip_attach.c:import_device(). It is needed to distinguish the
condition to be able to retry from other unrecoverable errors.
It is possible to avoid this failure by introducing userspace exclusive
control. But it's exaggerated for this special condition. The locking
itself has done in driver.
As an alternate solution, userspace doesn't specify port number, driver
searches unused port and it returns port number to the userspace. With
this solution, the interface is much different than this patch.
Signed-off-by: Nobuo Iwata <nobuo.iwata@fujixerox.co.jp>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds a USB3 HCD to an existing USB2 HCD and provides
the support of SuperSpeed, in case the device can only be enumerated
with SuperSpeed.
The bulk of the added code in usb3_bos_desc and hub_control to support
SuperSpeed is borrowed from the commit 1cd8fd2887 ("usb: gadget:
dummy_hcd: add SuperSpeed support").
With this patch, each vhci will have VHCI_HC_PORTS HighSpeed ports
and VHCI_HC_PORTS SuperSpeed ports.
Suggested-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In parse_status(), all nports number of idev's are initiated to
0 by memset(), it is simply wrong, because parse_status() reads
the status sys file one by one, therefore, it can only update the
according vhci_driver->idev's for it to parse.
Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
GCC 7 now warns when switch statements fall through implicitly, and with
-Werror enabled in configure.ac, that makes these tools unbuildable.
We fix this by notifying the compiler that this particular case statement
is meant to fall through.
Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Jonathan Dieter <jdieter@lesbg.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes checking of socket descriptor value in daemons.
It was checked to be less than FD_SETSIZE(1024 usually) but it's not
correct.
To be exact, the maximum value of descriptor comes from
rlimit(RLIMIT_NOFILE).
Following kernel code determines the value :
get_unused_fd_flags() : fs/files.c
__alloc_fd() : fs/files.c
expand_files() : fs/files.c
The defalut (soft limit) is defines as INR_OPEN_CUR(1024) in
include/linux/fs.h which is referenced form INIT_RLIMS in
include/asm-generic/resource.h. The value may be modified with ulimt,
sysctl, security configuration and etc.
With the kernel code above, when socket() system call returns positive
value, the value must be within rlimit(RLIMIT_NOFILE). No extra
checking is needed when socket() returns positive.
Without 'usbip: vhci number of ports extension' patch set, there's no
practical problem because of number of USB port restriction. With the
patch set, the value of socket descriptor can exceed FD_SETSIZE(1024
usually) if the rlimit is changed.
Signed-off-by: Nobuo Iwata <nobuo.iwata@fujixerox.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of calling strlen on every iteration of the for loop, just call it
once and cache the result in a temporary local variable which will be used
in the for loop instead.
Signed-off-by: Eric Curtin <ericcurtin17@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Delete a local structure that is only used to be initialized by memset.
A semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
identifier x,i;
@@
{
... when any
-struct i x;
<+... when != x
- memset(&x,...);
...+>
}
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Valentina Manea <valentina.manea.m@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At this point, USB/IP userspace code is fully functional
and can be moved out of staging.
Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
