Quote Dan:

The patch e36e6493: "uas: Use GFP_NOIO rather then GFP_ATOMIC
where possible" from Nov 7, 2013, leads to the following static
checker warning:

        drivers/usb/storage/uas.c:806 uas_eh_task_mgmt()
        error: scheduling with locks held: 'spin_lock:lock'

Some other allocations under spinlock are not caught.
The fix essentially reverts e36e6493Signed-off-by: NOliver Neukum <oliver@neukum.org>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Although an interesting concept, I don't think that this is a good idea:

-This will result in lots of "virtual" scsi controllers confusing users
-If we get a scsi-bus-reset we will now need to do a usb-device-reset of all
 uas devices on the same usb bus, which is something to avoid if possible
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

At the kernel-summit Sarah Sharp asked me if I was willing to become the
uas maintainer. I said yes, and here is a patch to make this official.

Also remove Matthew Wilcox and Sarah Sharp as maintainers at their request.

I've also added myself to the module's author tag, so that if people look there
rather then in maintainers they will know they should bug me about uas too.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Copy the sg alignment trick from the usb-storage driver, without this I'm
seeing intermittent errors when using uas devices with an ehci controller.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The scsi error handling path re-uses previously queued up (and errored-out)
cmds. If such a re-used cmd had a data-phase then cmdinfo will have
data_in_urb / data_out_urb still set to the free-ed urbs from the errored-out
cmd, and they will get free-ed a second time when the error handling cmd
completes, corrupting the kernel heap.

Clearing cmdinfo on command queue-ing fixes this, and seems like a good idea
in general.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The scsi-host structure is refcounted, scsi_remove_host tears down the
scsi-host but does not decrement the refcount, so we need to call
scsi_put_host on disconnect to get the underlying memory to be freed.

After calling scsi_remove_host, the scsi-core may still hold a reference to
the scsi-host, iow we may still get called after uas_disconnect, but we
do our own life cycle management of uas_devinfo, freeing it on disconnect,
and thus may end up using devinfo after it has been freed. Switch to letting
scsi_host_alloc allocate and manage the memory for us.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

cmds are either on the inflight list or on the dead list, never both, so
we only need one list head.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Before this commit the uas driver would keep track of scsi commands which still
need to have some urbs submitted to the device, and complete this with an
ABORT result code on bus-reset or disconnect, but in flight scsi commands
which have all their urbs submitted, and thus are not part of the work list,
would never get their done callback called.

The problem is killed sense urbs don't have any tag info, so it is impossible
to tell which scsi cmd they belong to, so merely making sure all the urbs
have completed one way or the other is not enough.

This commit fixes this by changing the work list to an inflight list, which
keeps tracks of all inflight scsi cmnds, using the IS_IN_WORK_LIST flag to
determine if actual work needs to be done in uas_do_work(), and by moving
marking all inflight scsi commands as aborted and moving them to the dead list
on bus-reset or disconnect.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

uas_alloc_data_urb always gets called with a stream_id value of 0 when not
using streams. Removing the check makes it consistent with uas_alloc_sense_urb.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

For USB-2 connections the stream-id must always be 0.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Some BIOS-es will hang on reboot when an uas device is attached and left in
uas mode on reboot.

This commit adds a shutdown handler which on reboot puts the device back into
usb-storage mode, fixing the hang on reboot on these systems.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

We can sleep in our own workqueue (which is the whole reason for having
it), and scsi error handlers are also always called from a context which
may sleep.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Since we use a fixed tag / stream for tasks we cannot allow more then one
to run at the same time. This could happen before this time if a task timed
out.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The fixed endpoint config code was only necessary to deal with an early
uas prototype which has never been released, so lets drop it and enforce
proper uas endpoint descriptors.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

No changes, just the move.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The loop uses up to 3 bytes of the endpoint extra data.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This is a preparation patch for adding better descriptor validation.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Once we start supporting uas hardware, and as more and more uas devices
become available, we will likely start seeing broken devices. This patch
prepares for the inevitable need for blacklisting those devices from
using the uas driver (they will use usb-storage instead).
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This is a preparation patch for teaching usb-storage to not bind to
uas devices.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This is a preparation patch for teaching usb-storage to not bind to
uas devices.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

If we get ie 16 streams we can use stream-id 1-16, not 1-15.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Handle usb-device resets not triggered from uas_eh_bus_reset_handler(), when
this happens, disable cmd queuing during the reset, and wait for existing
requests to finish in pre_reset.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Fix the uas_eh_bus_reset_handler not properly taking the usbdev lock
before calling usb_device_reset, the usb-core expects this lock to be
taken when usb_device_reset is called.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

I thought it would be a good idea to also test uas with usb-2, and it turns out
it was, as it did not work. The problem is that the uas driver was passing the
bEndpointAddress' direction bit to usb_rcvbulkpipe, the xhci code seems to not
care about this, but with the ehci code this causes usb_submit_urb failure.

With this fixed the uas code works nicely with an uas device plugged into
an ehci port.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The cmd endpoint never has streams, so the stream_id parameter is unused.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

All callers of unlink_data_urbs drop devinfo->lock before calling it, and
then immediately take it again after the call. And the first thing
unlink_data_urbs does is take the lock again, and the last thing it does
is drop it. This commit removes all the unnecessary lock dropping and taking.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

- Rename labels to properly reflect this
- Don't skip free-ing the streams when scsi_init_shared_tag_map fails
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Otherwise they may complete before they get anchored and thus never get
unanchored (as the unanchoring is done by the usb core on completion).

This commit also remove the usb_get_urb / usb_put_urb around cmd submission +
anchoring, since if done in the proper order this is not necessary.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch adds a new list where all requests which are canceled are
added to, so we don't loose them.  Then, after killing all inflight
urbs on bus reset (and disconnect) we'll walk over the list and clean
them up.

Without this we can end up with aborted requests lingering around in
case of status pipe transfer errors.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Simplifies locking, we'll protect the list with the device spin lock.
Also plugs races which can happen when two devices operate on the
global list.

While being at it rename the list head from "list" to "work", preparing
for the addition of a second list.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>