IB/iser: Prevent invalidating wrong MR

The iser_reg_resources structure has two pointers to MR but only one
mr_valid field. The implementation assumes that we use only *sig_mr when
pi_enable is true. Otherwise, we use only *mr. However, it is only
sometimes correct. Read commands without protection information occur even
when pi_enble is true. For example, the following SCSI commands have a
Data-In buffer but never have protection information: READ CAPACITY (16),
INQUIRY, MODE SENSE(6), MAINTENANCE IN. So, we use
*sig_mr for some SCSI commands and *mr for the other SCSI commands.

In most cases, it works fine because the remote invalidation is applied.
However, there are two cases when the remote invalidation is not
applicable.
1. Small write commands when all data is sent as an immediate.
2. The target does not support the remote invalidation feature.

The lazy invalidation is used if the remote invalidation is impossible.
Since, at the lazy invalidation, we always invalidate the MR we want to
use, the wrong MR may be invalidated.

To fix the issue, we need a field per MR that indicates the MR needs
invalidation. Since the ib_mr structure already has such a field, let's
use ib_mr.need_inval instead of iser_reg_resources.mr_valid.

Fixes: b76a439982f8 ("IB/iser: Use IB_WR_REG_MR_INTEGRITY for PI handover")
Link: https://lore.kernel.org/r/20231219072311.40989-1-sergeygo@nvidia.com
Acked-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Sergey Gorenko <sergeygo@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

IB/iser: remove redundant new line

This commit doesn't change any logic.

Reviewed-by: Sergey Gorenko <sergeygo@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Link: https://lore.kernel.org/r/20230330131333.37900-3-mgurtovoy@nvidia.com
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

IB/iser: centralize setting desc type and done callback

Move this common logic into iser_create_send_desc instead of duplicating
the code.

Reviewed-by: Sergey Gorenko <sergeygo@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Link: https://lore.kernel.org/r/20230330131333.37900-2-mgurtovoy@nvidia.com
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

IB/iser: Fix login with authentication

The iSER Initiator uses two types of receive buffers:

- one big login buffer posted by iser_post_recvl();
- several small message buffers posted by iser_post_recvm().

The login buffer is used at the login phase and full feature phase in
the discovery session. It may take a few requests and responses to
complete the login phase. The message buffers are only used in the
normal operational session at the full feature phase.

After the commit referred in the fixes line, the login operation fails
if the authentication is enabled. That happens because the Initiator
posts a small receive buffer after the first response from Target. So,
the next send operation fails because Target's second response does not
fit into the small receive buffer.

This commit adds additional checks to prevent posting small receive
buffers until the full feature phase.

Fixes: 39b169ea0d36 ("IB/iser: Fix RNR errors")
Link: https://lore.kernel.org/r/20220805060135.18493-1-sergeygo@nvidia.com
Signed-off-by: Sergey Gorenko <sergeygo@nvidia.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

IB/iser: Fix error flow in case of registration failure

During READ/WRITE preparation, in case of failure in memory registration
using iser_reg_mem_fastreg we must unmap previously mapped iser task.

Link: https://lore.kernel.org/r/20220308145546.8372-5-mgurtovoy@nvidia.com
Reviewed-by: Sergey Gorenko <sergeygo@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

IB/iser: Generalize map/unmap dma tasks

Avoid code duplication and add the mapping/unmapping of the protection
buffers to the iser_dma_map_task_data/iser_dma_unmap_task_data functions.

Link: https://lore.kernel.org/r/20220308145546.8372-4-mgurtovoy@nvidia.com
Reviewed-by: Sergey Gorenko <sergeygo@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

IB/iser: Use iser_fr_desc as registration context

After removing the FMR support in iSER, there is only one type of
registration context. Replace the void pointer with the explicit structure
for registration (struct iser_fr_desc).

Link: https://lore.kernel.org/r/20220308145546.8372-3-mgurtovoy@nvidia.com
Reviewed-by: Sergey Gorenko <sergeygo@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

IB/iser: Align coding style across driver

The following changes were made:
1. Align function signatures to 80 characters per line.
2. Remove tabs for variable assignment and use 1 space instead.
3. Don't compare to NULL in "if" clause.
4. Remove strange indentations.

This will ease on the maintenance of the driver for the future.

Link: https://lore.kernel.org/r/20211215135721.3662-7-mgurtovoy@nvidia.com
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

IB/iser: Don't suppress send completions

In order to complete a scsi command and guarantee that the HCA will never
perform an access violation when retrying a send operation we must
complete a scsi request only when both send and receive completions has
arrived. This is a preparation commit that remove the send completions
suppression. Next step will be taking care of the local invalidation
mechanism and adding a reference counter for commands. Currently, we
don't do anything upon getting the send completion and just "consume" it.

Link: https://lore.kernel.org/r/20211215135721.3662-5-mgurtovoy@nvidia.com
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Israel Rukshin <israelr@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

IB/iser: Fix RNR errors

Some users complain about RNR errors on the target, when heavy
high-priority tasks run on the initiator. After the investigation, we
found out that the receive WRs were exhausted, because the initiator could
not post them on time.

Receive work reqeusts are posted in chunks to reduce the number of hits to
the HCA. The WRs are posted in the receive completion handler when the
number of free receive buffers reaches the threshold. But on a high-loaded
host, receive CQEs processing can be delayed and all receive WRs will be
exhausted. In this case, the target will get an RNR error.

To avoid this, we post receive WR, as soon as possible and not in a
batch. This increases the number of hits to the HCA, but also the common
implementation in most of Linux ULPs (e.g. NVMe-oF/RDMA). As a rule of
thumb, performance improvements and heuristics are being added to the RDMA
core layer or vendors low level drivers and it's about time to align iSER
as well.

Link: https://lore.kernel.org/r/20211215135721.3662-3-mgurtovoy@nvidia.com
Signed-off-by: Sergey Gorenko <sergeygo@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Israel Rukshin <israelr@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/iser: Remove support for FMR memory registration

FMR is not supported on most recent RDMA devices (that use fast memory
registration mechanism). Also, FMR was recently removed from NFS/RDMA
ULP.

Link: https://lore.kernel.org/r/1-v3-f58e6669d5d3+2cf-fmr_removal_jgg@mellanox.com
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

infiniband: fix ulp/iser/iser_initiator.c kernel-doc warnings

Add kernel-doc notation for missing function parameters:

../drivers/infiniband/ulp/iser/iser_initiator.c:365: warning: Function parameter or member 'conn' not described in 'iser_send_command'
../drivers/infiniband/ulp/iser/iser_initiator.c:365: warning: Function parameter or member 'task' not described in 'iser_send_command'
../drivers/infiniband/ulp/iser/iser_initiator.c:437: warning: Function parameter or member 'conn' not described in 'iser_send_data_out'
../drivers/infiniband/ulp/iser/iser_initiator.c:437: warning: Function parameter or member 'task' not described in 'iser_send_data_out'
../drivers/infiniband/ulp/iser/iser_initiator.c:437: warning: Function parameter or member 'hdr' not described in 'iser_send_data_out'

Link: https://lore.kernel.org/r/20191010035240.132033937@gmail.com
Signed-off-by: Randy Dunlap <rd.dunlab@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/iser: Use IB_WR_REG_MR_INTEGRITY for PI handover

Using this new API reduces iSER code complexity.
It also reduces the maximum number of work requests per task and the need
of dealing with multiple MRs (and their registrations and invalidations)
per task. It is done by using a single WR and a special MR type
(IB_MR_TYPE_INTEGRITY) for PI operation.

The setup of the tested benchmark:
- 2 servers with 24 cores (1 initiator and 1 target)
- 24 target sessions with 1 LUN each
- ramdisk backstore
- PI active

Performance results running fio (24 jobs, 128 iodepth) using
write_generate=0 and read_verify=0 (w/w.o patch):

bs IOPS(read) IOPS(write)
---- ---------- ----------
512 1236.6K/1164.3K 1357.2K/1332.8K
1k 1196.5K/1163.8K 1348.4K/1262.7K
2k 1016.7K/921950 1003.7K/931230
4k 662728/600545 595423/501513
8k 385954/384345 333775/277090
16k 222864/222820 170317/170671
32k 116869/114896 82331/82244
64k 55205/54931 40264/40021

Using write_generate=1 and read_verify=1 (w/w.o patch):

bs IOPS(read) IOPS(write)
---- ---------- ----------
512 1090.1K/1030.9K 1303.9K/1101.4K
1k 1057.7K/904583 1318.4K/988085
2k 965226/638799 1008.6K/692514
4k 555479/410151 542414/414517
8k 298675/224964 264729/237508
16k 133485/122481 164625/138647
32k 74329/67615 80143/78743
64k 35716/35519 39294/37334

We get performance improvement at all block sizes.
The most significant improvement is when writing 4k bs (almost 30% more
iops).

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/iser: Fix possible NULL deref at iser_inv_desc()

In case target remote invalidates bogus rkey and signature is not used,
pi_ctx is NULL deref.

The commit also fails the connection on bogus remote invalidation.

Fixes: 59caaed7a72a ("IB/iser: Support the remote invalidation exception")
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

treewide: kmalloc() -> kmalloc_array()

The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

kmalloc(a * b, gfp)

with:
kmalloc_array(a * b, gfp)

as well as handling cases of:

kmalloc(a * b * c, gfp)

with:

kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kmalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kmalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kmalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kmalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kmalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kmalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kmalloc(sizeof(THING) * C2, ...)
|
kmalloc(sizeof(TYPE) * C2, ...)
|
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * E2
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

IB/iser: Do not reduce max_sectors

The iSER driver reduces max_sectors. For example, if you load the
ib_iser module with max_sectors=1024, you will see that
/sys/class/block/<bdev>/queue/max_hw_sectors_kb is 508. It is an
incorrect value. The expected value is (max_sectors * sector_size) /
1024 = 512.

Reducing of max_sectors can cause performance degradation due to
unnecessary splitting of IO requests.

The number of pages per MR has been fixed here, so there is no longer
any need to reduce max_sectors.

Fixes: 9c674815d346 ("IB/iser: Fix max_sectors calculation")
Signed-off-by: Sergey Gorenko <sergeygo@mellanox.com>
Reviewed-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Combine substrings for three messages

The script "checkpatch.pl" pointed information out like the following.

WARNING: quoted string split across lines

Thus fix the affected source code places.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/iser: Delete an unnecessary variable initialisation in iser_send_data_out()

The variable "tx_desc" will be set to an appropriate pointer a bit later.
Thus omit the explicit initialisation at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/iser: Delete an error message for a failed memory allocation in iser_send_data_out()

Omit an extra message for a memory allocation failure in this function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/iser: don't send an rkey if all data is written as immadiate-data

We might get some bogus error completions in case the target will
remotely invalidate the rkey and the HCA will need to retransmit
from this buffer.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: fix spelling mistake: "unexepected" -> "unexpected"

trivial fix to spelling mistake in iser_err error message

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Use ib_drain_sq()

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Support the remote invalidation exception

Declare that we support remote invalidation in case we are:
1. using fastreg method
2. always registering memory

Detect the invalidated rkey from the work completion info so we
won't invalidate it locally. The spec mandates that we must not rely
on the target remote invalidate our rkey so we must check it upon
a receive (scsi response) completion.

Signed-off-by: Jenny Derzhavetz <jennyf@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser,isert: Create and use new shared header

The iser RDMA_CM negotiation protocol is shared by
the initiator and the target, so have a shared header
for the defines and structure. Move relevant items from
the initiator and target headers.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jenny Derzhavetz <jennyf@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Don't register memory for all immediate data writes

When all the task data is sent as immediate data, we are
allowed to use the local_dma_lkey as it is not sent to
the wire.

Signed-off-by: Jenny Derzhavetz <jennyf@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Convert to CQ abstraction

Use the new CQ abstraction to simplify completions in the iSER
initiator.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/iser: Use helper for container_of

Nicer this way.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/iser: Use a dedicated descriptor for login

We'll need it later with the new CQ abstraction. also switch
login bufs to void pointers.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/iser: set block queue_virt_boundary

The block layer can reliably guarantee that SG lists won't
contain gaps (page unaligned) if a driver set the queue
virt_boundary.

With this setting the block layer will:
- refuse merges if bios are not aligned to the virtual boundary
- split bios/requests that are not aligned to the virtual boundary
- or, bounce buffer SG_IOs that are not aligned to the virtual boundary

Since iser is working in 4K page size, set the virt_boundary to
4K pages. With this setting, we can now safely remove the bounce
buffering logic in iser.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Use pd->local_dma_lkey

Replace all leys with pd->local_dma_lkey. This driver does not support
iWarp, so this is safe.

The insecure use of ib_get_dma_mr is thus isolated to an rkey, and this
looks trivially fixed by forcing the use of registration in a future
patch.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Support up to 8MB data transfer in a single command

iser support up to 512KB data transfer in a single scsi command.
This means that larger IOs will split to different request. While
iser can easily saturate FDR/EDR wires, some arrays are fine tuned
for 1MB (or larger) IO sizes, hence add an option to support larger
transfers (up to 8MB) if the device allows it.

Given that a few target implementations don't support data transfers
of more than 512KB by default and the fact that larger IO sizes require
more resources, we introduce a module parameter to determine the
maximum number of 512B sectors in a single scsi command.
Users that are interested in larger transfers can change this value given
that the target supports larger transfers.

At the moment, iser works in 4K pages granularity, In a later stage
we will get it to work with system page size instead.

IO operations that consists of N pages will need a page vector
of size N+1 in case the first SG element contains an offset. Given
that some devices allocates memory regions in powers of 2, this
means that allocating a region with N+1 pages, will result in
region resources allocation of the next power of 2. Since we don't
want that to happen, in case we are in the limit of IO size supported
and the first SG element has an offset, we align the SG list using a
bounce buffer (which is OK given that this is not likely to happen a lot).

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Pass registration pool a size parameter

Hard coded for now. This will allow to allocate different
sized MRs depending on the IO size needed (and device
capabilities).

This patch does not change any functionality.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Unify fast memory registration flows

iser_reg_rdma_mem_[fastreg|fmr] share a lot of code, and
logically do the same thing other than the buffer registration
method itself (iser_fast_reg_mr vs. iser_fast_reg_fmr).
The DIF logic is not implemented in the FMR flow as there is no
existing device that supports FMRs and Signature feature.

This patch unifies the flow in a single routine iser_reg_rdma_mem
and just split to fmr/frwr for the buffer registration itself.

Also, for symmetry reasons, unify iser_unreg_rdma_mem (which will
call the relevant device specific unreg routine).

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Adir Lev <adirl@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Introduce iser_reg_ops

Move all the per-device function pointers to an easy
extensible iser_reg_ops structure that contains all
the iser registration operations.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Remove a redundant always-false condition

We always call iser_initialize_task_headers() and set
the header tx_sg.lkey to the device mr lkey, so no
point in checking it in iser_create_send_desc().

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Fix missing return status check in iser_send_data_out

Since commit "IB/iser: Fix race between iser connection teardown..."
iser_initialize_task_headers() might fail, so we need to check that.

Fixes: 7414dde0a6c3a958e (IB/iser: Fix race between iser connection ...)
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Rewrite bounce buffer code path

In some rare cases, IO operations may be not aligned to page
boundaries. This prevents iser from performing fast memory
registration. In order to overcome that iser uses a bounce
buffer to carry the transaction. We basically allocate a buffer
in the size of the transaction and perform a copy.

The buffer allocation using kmalloc is too restrictive since it
requires higher order (atomic) allocations for large transactions
(which may result in memory exhaustion fairly fast for some workloads).
We rewrite the bounce buffer code path to allocate scattered pages
and perform a copy between the transaction sg and the bounce sg.

Reported-by: Alex Lyakas <alex@zadarastorage.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Modify struct iser_mem_reg members

No need to keep lkey, va, len variables, we can keep
them as struct ib_sge. This will help when we change the
memory registration logic.

This patch does not change any functionality.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Adir Lev <adirl@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Get rid of struct iser_rdma_regd

This struct members other than struct iser_mem_reg are unused,
so remove it altogether.

This patch does not change any functionality.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Adir Lev <adirl@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Remove a redundant struct iser_data_buf

No need to keep two iser_data_buf structures just in case we use
mem copy. We can avoid that just by adding a pointer to the original
sg. So keep only two iser_data_buf per command (data and protection)
and pass the relevant data_buf to bounce buffer routine.

This patch does not change any functionality.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Adir Lev <adirl@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Fix wrong calculation of protection buffer length

This length miss-calculation may cause a silent data corruption
in the DIX case and cause the device to reference unmapped area.

Fixes: d77e65350f2d ('libiscsi, iser: Adjust data_length to include protection information')
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/iser: Fix memory regions possible leak

When teardown process starts during live IO, we need to keep the
memory regions pool (frmr/fmr) until all in-flight tasks are properly
released, since each task may return a memory region to the pool. In
order to do this, we pass a destroy flag to iser_free_ib_conn_res to
indicate we can destroy the device and the memory regions
pool. iser_conn_release will pass it as true and also DEVICE_REMOVAL
event (we need to let the device to properly remove).

Also, Since we conditionally call iser_free_rx_descriptors,
remove the extra check on iser_conn->rx_descs.

Fixes: 5426b1711fd0 ("IB/iser: Collapse cleanup and disconnect handlers")
Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Use correct dma direction when unmapping SGs

We always unmap SGs with the same direction instead of unmapping
with the direction the mapping was done, fix that.

Fixes: 9a8b08fad2ef ("IB/iser: Generalize iser_unmap_task_data and [...]")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Fix possible SQ overflow

Fix a regression was introduced in commit 6df5a128f0fd ("IB/iser:
Suppress scsi command send completions").

The sig_count was wrongly set to be static variable, thus it is
possible that we won't reach to (sig_count % ISER_SIGNAL_BATCH) == 0
condition (due to races) and the send queue will be overflowed.

Instead keep sig_count per connection. We don't need it to be atomic
as we are safe under the iscsi session frwd_lock taken by libiscsi on
the queuecommand path.

Fixes: 6df5a128f0fd ("IB/iser: Suppress scsi command send completions")
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Suppress scsi command send completions

Singal completion of every 32 scsi commands and suppress all the rest.
We don't do anything upon getting the completion so no need to "just
consume" it. Cleanup of scsi command is done in cleanup_task callback.

Still keep dataout and control send completions as we may need to
cleanup there. This helps reducing the amount of interrupts/completions
in the IO path.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Use beacon to indicate all completions were consumed

Avoid post_send counting (atomic) in the IO path just to keep track of
how many completions we need to consume. Use a beacon post to indicate
that all prior posts completed.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Use single CQ for RX and TX

This will solve a possible condition where we might miss TX completion
(flush error) during session teardown. Since we are using a single
CQ, we don't need to actively drain the TX CQ, instead just wait for
flush_completion (when counters reach zero) and remove iser_poll_for_flush_errors().

This patch might introduce a minor performance regression on its own,
but the next patches will enhance performance using a single CQ for RX
and TX.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Re-introduce ib_conn

Structure that describes the RDMA relates connection objects. Static
member of iser_conn.

This patch does not change any functionality

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Rename ib_conn -> iser_conn

Two reasons why we choose to do this:

1. No point today calling struct iser_conn by another name ib_conn
2. In the next patches we will restructure iser control plane representation
- struct iser_conn: connection logical representation
- struct ib_conn: connection RDMA layout representation

This patch does not change any functionality.

Signed-off-by: Ariel Nahum <arieln@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

libiscsi, iser: Adjust data_length to include protection information

In case protection information exists over the wire
iscsi header data length is required to include it.
Use protection information aware scsi helpers to set
the correct transfer length.

In order to avoid breakage, remove iser transfer length
checks for each task as they are not always true and
somewhat redundant anyway.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: stable@vger.kernel.org # 3.15+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

IB/iser: Update Mellanox copyright note

Update Mellanox copyrights for 2014 on the iser initiator driver.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Remove struct iscsi_iser_conn

The iscsi stack has existing mechanisms to link back and forth between
the iscsi connection and the iscsi transport (e.g iser/tcp) connection.

This is done through a dd_data pointer field in struct iscsi_conn
which can be set to point to the transport connection, etc.

The iscsi_iser_conn structure was used to get this linking done in
another way, which is uneeded and adds extra complication to the iser
code, so we just remove it.

Signed-off-by: Ariel Nahum <arieln@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Support T10-PI operations

Add logic to initialize protection information entities. Upon each
iSCSI task, we keep the scsi_cmnd in order to query the scsi
protection operations and reference to protection buffers.

Modify iser_fast_reg_mr to receive indication whether it is
registering the data or protection buffers.

In addition introduce iser_reg_sig_mr which performs fast registration
work-request for a signature enabled memory region
(IB_WR_REG_SIG_MR). In this routine we set all the protection
relevants for the device to offload protection data-transfer and
verification.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Alex Tabachnik <alext@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Generalize iser_unmap_task_data and finalize_rdma_unaligned_sg

This routines operates on data buffers and may also work with
protection infomation buffers. So we generalize them to handle an
iser_data_buf which can be the command data or command protection
information.

This patch does not change any functionality.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Fix use after free in iser_snd_completion()

We use "tx_desc" again after we free it.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Fix redundant pointer check in dealloc flow

This bug was discovered by Smatch static checker run by Dan Carpenter.
If in free_rx_descriptors(), rx_descs are not NULL then the iser
device is definately not NULL, so no need to check it before
dereferencing it.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

[SCSI] IB/iser: Add Discovery support

To run discovery over iSER we need to advertize the CAP_TEXT_NEGO capability
towards user space. Also need to make sure the login RX buffer is posted when
SendTargets TEXT PDUs are sent. For that end, we use a setting of the
ISCSI_PARAM_DISCOVERY_SESS iscsi param as an indication that this is
discovery session.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

IB/iser: Generalize rdma memory registration

Currently the driver uses FMRs as the only means to register the
memory pointed by SG provided by the SCSI mid-layer with the RDMA
device.

As preparation step for adding more methods for fast path memory
registration, make the alloc/free and reg/unreg calls function
pointers, which are for now just set to the existing FMR ones.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Accept session->cmds_max from user space

Use cmds_max passed from user space to be the number of PDUs to be
supported for the session instead of hard-coded ISCSI_DEF_XMIT_CMDS_MAX.
This allow controlling the max number of SCSI commands for the session.
Also don't ignore the qdepth passed from user space.

Derive from session->cmds_max the actual number of RX buffers and FMR
pool size to allocate during the connection bind phase.

Since the iser transport connection is established before the iscsi
session/connection are created and bound, we still use one hard-coded
quantity ISER_DEF_XMIT_CMDS_MAX to compute the maximum number of
work-requests to be supported by the RC QP used for the connection.

The above quantity is made to be a power of two between ISCSI_TOTAL_CMDS_MIN
(16) and ISER_DEF_XMIT_CMDS_MAX (512) inclusive.

Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Restructure allocation/deallocation of connection resources

This is a preparation step to a patch that accepts the number of max
SCSI commands to be supported a session from user space iSCSI tools.

Move the allocation of the login buffer, FMR pool and its associated
page vector from iser_create_ib_conn_res() (which is called prior when
we actually know how many commands should be supported) to
iser_alloc_rx_descriptors() (which is called during the iscsi
connection bind step where this quantity is known).

Also do small refactoring around the deallocation to make that path
similar to the allocation one.

Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Add Mellanox copyright

Add Mellanox copyright to the iser initiator source code which I maintain.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Post initial receive buffers before sending the final login request

An iser target may send iscsi NO-OP PDUs as soon as it marks the iSER
iSCSI session as fully operative. This means that there is window
where there are no posted receive buffers on the initiator side, so
it's possible for the iSER RC connection to break because of RNR NAK /
retry errors. To fix this, rely on the flags bits in the login
request to have FFP (0x3) in the lower nibble as a marker for the
final login request, and post an initial chunk of receive buffers
before sending that login request instead of after getting the login
response.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Free IB connection resources in the proper place

We allocate the login dma buffers in iser_verbs.c as part of
alloc_ib_conn_resources(), however we are freeing them in
iser_initiator.c as part of iser_free_rx_descriptors(). This is
needlessly confusing. We have an alloc_rx_descriptors() and it
doesn't alloc something that the free_rx_descriptors() frees, and we
have an alloc_ib_conn_resources() that allocs something not freed by
free_ib_conn_resources(). Clean that up.

Signed-off-by: Doug Ledford <dledford@redhat.com>

[ Fix build error in iser_free_ib_conn_res(). - Or ]

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Use separate buffers for the login request/response

The driver counted on the transactional nature of iSCSI login/text
flows and used the same buffer for both the request and the response.
We also went further and did DMA mapping only once, with
DMA_FROM_DEVICE, which violates the DMA mapping API. Fix that by
using different buffers, one for requests and one for responses, and
use the correct DMA mapping direction for each.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/iser: Support iSCSI PDU padding

RFC3270 mandates that iSCSI PDUs are padded to the closest integer
number of four byte words. Fix the iser code to support that on both
the TX/RX flows.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>

iscsi: Resolve iscsi_proto.h naming conflicts with drivers/target/iscsi

This patch renames the following iscsi_proto.h structures to avoid
namespace issues with drivers/target/iscsi/iscsi_target_core.h:

*) struct iscsi_cmd -> struct iscsi_scsi_req
*) struct iscsi_cmd_rsp -> struct iscsi_scsi_rsp
*) struct iscsi_login -> struct iscsi_login_req

This patch includes useful ISCSI_FLAG_LOGIN_[CURRENT,NEXT]_STAGE*,
and ISCSI_FLAG_SNACK_TYPE_* definitions used by iscsi_target_mod, and
fixes the incorrect definition of struct iscsi_snack to following
RFC-3720 Section 10.16. SNACK Request.

Also, this patch updates libiscsi, iSER, be2iscsi, and bn2xi to
use the updated structure definitions in a handful of locations.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>

IB/iser: Make needlessly global iser_alloc_rx_descriptors() static

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: Remove redundant locking from iser scsi command response flow

Currently the iSER receive completion flow takes the session lock
twice. Optimize it to avoid the first one by letting
iser_task_rdma_finalize() be called only from the cleanup_task
callback invoked by iscsi_free_task, thus reducing the contention on
the session lock between the scsi command submission to the scsi
command completion flows.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: Use libiscsi passthrough mode

libiscsi passthrough mode invokes the transport xmit calls directly
without first going through an internal queue, unlike the other mode,
which uses a queue and a xmitworker thread. Now that the "cant_sleep"
prerequisite of iscsi_host_alloc is met, move to use it. Handling
xmit errors is now done by the passthrough flow of libiscsi. Since
the queue/worker aren't used in this mode, the code that schedules the
xmitworker is removed.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: Remove unnecessary connection checks

Remove unnecessary checks for the IB connection state and for QP
overflow, as conn state changes are reported by iSER to libiscsi and
handled there. QP overflow is theoretically possible only when
unsolicited data-outs are used; anyway it's being checked and handled
by HW drivers.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: Use atomic allocations

Two minor flows in iSER's data path still use allocations; move them
to be atomic as a preperation step towards moving to use libiscsi
passthrough mode.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: Simplify send flow/descriptors

Simplify and shrink the logic/code used for the send descriptors.
Changes include removing struct iser_dto (an unnecessary abstraction),
using struct iser_regd_buf only for handling SCSI commands, using
dma_sync instead of dma_map/unmap, etc.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: Remove atomic counter for posted receive buffers

Now that both the posting and reaping of receive buffers is done in
the completion path, the counter of outstanding buffers not be atomic.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: New receive buffer posting logic

Currently, the recv buffer posting logic is based on the transactional
nature of iSER which allows for posting a buffer before sending a PDU.
Change this to post only when the number of outstanding recv buffers
is below a water mark and in a batched manner, thus simplifying and
optimizing the data path. Use a pre-allocated ring of recv buffers
instead of allocating from kmem cache. A special treatment is given
to the login response buffer whose size must be 8K unlike the size of
buffers used for any other purpose which is 128 bytes.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: Revert commit bba7ebb "avoid recv buffer exhaustion"

We will make a major change in the recv buffer posting logic, after
which the problem commit bba7ebb "avoid recv buffer exhaustion caused
by unexpected PDUs" comes to solve doesn't exist any more, so revert it.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

[SCSI] iscsi lib: have lib create work queue for transmitting IO

We were using the shost work queue which ended up being
a little akward since all iscsi hosts need a thread for
scanning, but only drivers hooked into libiscsi need
a workqueue for transmitting. So this patch moves the
xmit workqueue to the lib.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] iser: convert iser to new alloc_pdu api

This just converts iser to new alloc_pdu api. It still
preallocates the pdu, so there is no difference.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

IB/iser: Avoid recv buffer exhaustion caused by unexpected PDUs

iSCSI/iSER targets may send PDUs without a prior request from the
initiator. RFC 5046 refers to these PDUs as "unexpected". NOP-In PDUs
with itt=RESERVED and Asynchronous Message PDUs occupy this category.

The amount of active "unexpected" PDU's an iSER target may have at any
time is governed by the MaxOutstandingUnexpectedPDUs key, which is not
yet supported.

Currently when an iSER target sends an "unexpected" PDU, the
initiators recv buffer consumed by the PDU is not replaced. If over
initial_post_recv_bufs_num "unexpected" PDUs are received then the
receive queue will run out of receive work requests entirely.

This patch ensures recv buffers consumed by "unexpected" PDUs are
replaced in the next iser_post_receive_control() call.

Signed-off-by: David Disseldorp <ddiss@sgi.com>
Signed-off-by: Ken Sandars <ksandars@sgi.com>
Acked-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

RDMA: Remove subversion $Id tags

They don't get updated by git and so they're worse than useless.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

[SCSI] libiscsi, iser, tcp: remove recv_lock

The recv lock was defined so the iscsi layer could block
the recv path from processing IO during recovery. It
turns out iser just set a lock to that pointer which was pointless.

We now disconnect the transport connection before doing recovery
so we do not need the recv lock. For iscsi_tcp we still stop
the recv path incase older tools are being used.

This patch also has iscsi_itt_to_ctask user grab the session lock
and has the caller access the task with the lock or get a ref
to it in case the target is broken and sends a tmf success response
then sends data or a response for the command that was supposed to
be affected bty the tmf.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] iser: handle iscsi_cmd_task rename

This handles the iscsi_cmd_task rename and renames
the iser cmd task to iser task.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] iser: convert ib_iser to support merged tasks

Convert ib_iser to support merged tasks.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libiscsi, iscsi_tcp, iser: add session cmds array accessor

Currently to get a ctask from the session cmd array, you have to
know to use the itt modifier. To make this easier on LLDs and
so in the future we can easilly kill the session array and use
the host shared map instead, this patch adds a nice wrapper
to strip the itt into a session->cmds index and return a ctask.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

IB/iser: Don't change itt endianness

The itt field in struct iscsi_data is not defined with any particular
endianness. open-iscsi should use it as-is without byte-swapping it.
This fixes sparse warnings coming from doing ntohl(hdr->itt).

Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband: Add missing "space"

Add missing spaces in the middle of format strings.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

[SCSI] libiscsi: do not block session during logout

There is not need to block the session during logout. Since
we are going to fail the commands that were blocked just fail them
immediately instead.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

IB/iser: Remove unnecessary includes

<asm/scatterlist.h> is not needed because everyplace it appears,
<linux/scatterlist.h> also appears. <asm/io.h> is not needed because
nothing seems to be using device IO anyway.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

[SCSI] iscsi_iser: convert to use the data buffer accessors

iscsi_iser: convert to use the data buffer accessors

- remove the unnecessary map_single path.

- convert to use the new accessors for the sg lists and the
parameters.

TODO: use scsi_for_each_sg().

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

IB/iser: Handle aborting a command after it is sent

The SCSI midlayer may abort a command that was already sent. If the
initiator is still trying to send the command (or data-out PDUs for
that command), the QP may time out after the midlayer times
out. Therefore, when aborting the command, iSER may still have
references for the command's buffers. When sending these PDUs, the
sends will complete with an error and their resources will be released
then.

Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

[SCSI] iscsi: rename DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH

This patch renames DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH to avoid
confusion with the drivers default values (DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH
is the iscsi RFC specific default).

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] iscsi endianness annotations

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/iser: Return error code when PDUs may not be sent

iSER limits the number of outstanding PDUs to send. When this threshold
is reached, it should return an error code (-ENOBUFS) instead of setting
the suspend_tx bit (which should be used only by libiscsi).

Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: Remove unused "write-only" variables

Remove variables that are set but then never looked at in the iSER
initiator. These cleanups came from David Binderman's list of "set
but never used" warnings from icc.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: DMA unmap unaligned for RDMA data before touching it

iSER uses the DMA mapping api to map the page holding the
SCSI command data to the HCA DMA address space. When the
command data is not aligned for RDMA, the data is copied
to/from an allocated buffer which in turn is used for
executing this command. The pages associated with the
command must be unmapped before being touched.

Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: Have iSER data transaction object point to iSER conn

iSER uses a data transaction object (struct iser_dto) as part
of its IB data descriptors (struct iser_desc) management.
It also uses a hierarchy of connection structures pointing to
each other. A DTO may exist even after the iscsi_iser connection
pointed by it is destroyed (eg one that is bound to a post
receive buffer which was flushed by the IB HW). Hence DTOs need
point to the lowest connection, which is struct iser_conn.

Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/iser: iSER initiator iSCSI PDU and TX/RX

This file contains the iSER initiator processing of iSCSI PDUs - controls,
commands and data-outs along with processing of TX and RX completions.
It interacts with the lower level iser code doing the memory registration
and and the cma and verbs calls.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>