FC disks issue I/O directly to the host storage port driver, this is
diffirent to VHD disks where I/O is virtualized and timeout is handled
by the host VSP (Virtualization Service Provider).

FC disks are usually setup in a multipath system, and they don't want to
reset timer on I/O timeout. Timeout is detected by multipath as a good
time to failover and recover.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In storvsc driver, inbound messages do not go through inbound lock.  The
only effect of this lock was is to provide a barrier for connect and
remove logic.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In 4.12-rc1, new functions were added to support iterating over elements
in the vmbus event ring. This patch uses them to simplify the ring
buffer handling in virtual SCSI driver as well.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Included in the current storvsc driver for Hyper-V is the ability to
access luns on an FC fabric via a virtualized fiber channel adapter
exposed by the Hyper-V host. The driver also attaches to the FC
transport to allow host and port names to be published under
/sys/class/fc_host/hostX. Current customer tools running on the VM
require that these names be available in the well known standard
location under fc_host/hostX.

This patch stubs in an rport per fc_host and sets its rport role as
FC_PORT_ROLE_FCP_DUMMY_INITIATOR to indicate to the fc_transport that it
is a pseudo rport in order to scan the scsi stack via echo "- - -" >
/sys/class/scsi_host/hostX/scan.
Signed-off-by: NCathy Avery <cavery@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

storvsc_on_channel_callback is a void function and the return
statement at the end is not useful.

Found with checkpatch.
Signed-off-by: NMiguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Use kcalloc for allocating an array instead of kzalloc with multiply,
kcalloc is the preferred API.

Found with checkpatch.
Signed-off-by: NMiguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Hyper-V host emulation of SCSI for virtual DVD device reports SCSI
version 0 (UNKNOWN) but is still capable of supporting REPORTLUN.

Without this patch, a GEN2 Linux guest on Hyper-V will not boot 4.11
successfully with virtual DVD ROM device. What happens is that the SCSI
scan process falls back to doing sequential probing by INQUIRY.  But the
storvsc driver has a previous workaround that masks/blocks all errors
reports from INQUIRY (or MODE_SENSE) commands.  This workaround causes
the scan to then populate a full set of bogus LUN's on the target and
then sends kernel spinning off into a death spiral doing block reads on
the non-existent LUNs.

By setting the correct blacklist flags, the target with the DVD device
is scanned with REPORTLUN and that works correctly.

Patch needs to go in current 4.11, it is safe but not necessary in older
kernels.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Fix typos and add the following to the scripts/spelling.txt:

  intialization||initialization

The "inintialization" in drivers/acpi/spcr.c is a different pattern but
I fixed it as well in this commit.

Link: http://lkml.kernel.org/r/1481573103-11329-16-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Instead define the timeout behavior purely based on the host_template
eh_timed_out method and wire up the existing transport implementations
in the host templates.  This also clears up the confusion that the
transport template method overrides the host template one, so some
drivers have to re-override the transport template one.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove a piece of code in storvsc_queuecommand that tries to pass the
physical address of the kernel struct scatterlist pointer to the host.

Fortunately the code can't ever be reached anyway.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

On I/O errors, the Windows driver doesn't set data_transfer_length
on error conditions other than SRB_STATUS_DATA_OVERRUN.
In these cases we need to set data_transfer_length to 0,
indicating there is no data transferred. On SRB_STATUS_DATA_OVERRUN,
data_transfer_length is set by the Windows driver to the actual data transferred.
Reported-by: NShiva Krishna <Shiva.Krishna@nimblestorage.com>
Signed-off-by: NLong Li <longli@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When sense message is present on error, we should pass along to the upper
layer to decide how to deal with the error.
This patch fixes connectivity issues with Fiber Channel devices.
Signed-off-by: NLong Li <longli@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Properly set SRB flags when hosting device supports tagged queuing.
This patch improves the performance on Fiber Channel disks.
Signed-off-by: NLong Li <longli@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Enable multi-q support. We will allocate the outgoing channel using
the following policy:

        1. We will make every effort to pick a channel that is in the
           same NUMA node that is initiating the I/O
        2. The mapping between the guest CPU and the outgoing channel
           is persistent.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove the artificially imposed restriction on max segment size.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Enable tracking of queue depth.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

On a 32 bit kernel sizeof(void *) is not 64 bits as hv_mpb_array
requires. Also the buffer needs to be cleared or the upper bytes will
contain junk.
Suggested-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NCathy Avery <cavery@redhat.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When a virtual scsi DVD device is present with no image file
attached the storvsc driver logs all resulting unnecessary sense errors
whenever IO is issued to the device.

[storvsc] Sense Key : Not Ready [current]
[storvsc] Add. Sense: Medium not present - tray closed

[mkp: Fixed whitespace]
Signed-off-by: NCathy Avery <cavery@redhat.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Commit 3209f9d7 ("scsi: storvsc: Fix a bug in the handling of SRB
status flags") filtered SRB_STATUS_AUTOSENSE_VALID out effectively making
the (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID) case a dead code. The
logic from this branch (e.g. storvsc_device_scan() call) is still required,
fix the check.

Cc: <stable@vger.kernel.org> #v4.4+
Fixes: 3209f9d7 ("scsi: storvsc: Fix a bug in the handling of SRB status flags")
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Commit 3209f9d7 ("scsi: storvsc: Fix a bug in the handling of SRB
status flags") filtered SRB_STATUS_AUTOSENSE_VALID out effectively making
the (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID) case a dead code. The
logic from this branch (e.g. storvsc_device_scan() call) is still required,
fix the check.

Cc: <stable@vger.kernel.org> #v4.4+
Fixes: 3209f9d7 ("scsi: storvsc: Fix a bug in the handling of SRB status flags")
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The current code assumes that there is only one target in device lookup.
Fix this bug. This will alow us to correctly handle hot reomoval of
LUNs.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NAlex Ng <alexng@microsoft.com>
Tested-by: NVivek Yadav <vyadav@microsoft.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The default timeout routine used for FC transport is not suitable for FC
devices managed by storvsc since FC devices managed by storvsc driver do
not have an rport associated with them. Use the time out handler used
for SCSI devices for FC devices as well.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NAlex Ng <alexng@microsoft.com>
Tested-by: NVivek Yadav <vyadav@microsoft.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The module_param is "storvsc_vcpus_per_sub_channel" so we need to use
that for MODULE_PARM_DESC() as well.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

On the interrupt path, we repeatedly establish the pointer to the
storvsc_device. While the compiler does inline get_in_stor_device() (and
other static functions) in the call chain in the interrupt path, the
compiler is repeatedly inlining the call to get_in_stor_device() each
time it is invoked.  The return value of get_in_stor_device() can be
cached in the interrupt path since there is higher level serialization
in place to ensure correct handling when the module unload races with
the processing of an incoming message from the host.  Optimize this code
path by caching the pointer to storvsc_device and passing it as an
argument.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The function storvsc_channel_init() repeatedly interacts with the host
to extract various channel properties. Refactor this code to eliminate
code repetition.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For FC devices managed by this driver, atttach the appropriate transport
template. This will allow us to create the appropriate sysfs files for
these devices. With this we can publish the wwn for both the port and the node.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The hv_fc_wwn_packet is exchanged over vmbus. Make the definition in
Linux match the Windows definition.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NLong Li <longli@microsoft.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Introduce a logging level for storvsc to log certain error/warning
messages. Those messages are helpful in some environments,
e.g. Microsoft Azure, for customer support and troubleshooting purposes.
Signed-off-by: NLong Li <longli@microsoft.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

SRB status can have additional information. Mask these out before processing
SRB status.

This patch was sent as part of a collection of patches more than a year ago.
While the rest of the patches in the set were comitted, this patch was not.
I woulod like to thank Olaf for noticing that this patch was not committed
upstream.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Storvsc driver needs to ensure there are no 'holes' in the presented
sg list (all segments in the middle of the list need to be of PAGE_SIZE).
When a hole is detected storvsc driver creates a 'bounce sgl' without
holes and copies data over with copy_{to,from}_bounce_buffer() functions.
Setting virt_boundary_mask to PAGE_SIZE - 1 guarantees we'll never see
such holes so we can significantly simplify the driver. This is also
supposed to bring us some performance improvement for certain workloads
as we eliminate copying.
Reported-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Don't set the SRB_FLAGS_QUEUE_ACTION_ENABLE flag since we are not specifying
tags.  Without this, the qlogic driver doesn't work properly with storvsc.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

In the function storvsc_channel_init(), error code was not getting
set correctly in some of the failure cases. Fix this issue.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Allow WRITE_SAME for Windows10 and above hosts.
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NKeith Mange <keith.mange@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Use storage protocol version instead of vmbus protocol
version when determining storage capabilities.
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NKeith Mange <keith.mange@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Use correct defaults for values determined by protocol negotiation,
instead of resetting them with every scsi controller.
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NKeith Mange <keith.mange@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Currently we are making decisions based on vmbus protocol versions
that have been negotiated; use storage potocol versions instead.

[jejb: fold ARRAY_SIZE conversion suggested by Johannes Thumshirn
<jthumshirn@suse.de>
make vmstor_protocol static]
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NKeith Mange <keith.mange@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Use a single value to track protocol versions to simplify
comparisons and to be consistent with vmbus version tracking.
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NKeith Mange <keith.mange@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Rather than look for sets of specific protocol versions,
make decisions based on ranges. This will be safer and require fewer changes
going forward as we add more storage protocol versions.
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NKeith Mange <keith.mange@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Comment in struct Scsi_Host says that drivers are not supposed to access
__devices directly. storvsc_host_scan() doesn't happen in irq context
so we can just use shost_for_each_device().
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Under the 'default' case in scmnd->sc_data_direction we have 3 options:
- DMA_NONE which we handle correctly.
- DMA_BIDIRECTIONAL which is never supposed to be set by SCSI stack.
- Garbage value.

Do WARN() and return -EINVAL in the last two cases. virtio_scsi does
BUG_ON() here but it looks like an overkill.
Reported-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>