RDMA/srpt: Fix a use-after-free

Change the LIO port members inside struct srpt_port from regular members
into pointers. Allocate the LIO port data structures from inside
srpt_make_tport() and free these from inside srpt_make_tport(). Keep
struct srpt_device as long as either an RDMA port or a LIO target port is
associated with it. This patch decouples the lifetime of struct srpt_port
(controlled by the RDMA core) and struct srpt_port_id (controlled by LIO).
This patch fixes the following KASAN complaint:

BUG: KASAN: use-after-free in srpt_enable_tpg+0x31/0x70 [ib_srpt]
Read of size 8 at addr ffff888141cc34b8 by task check/5093

Call Trace:
<TASK>
show_stack+0x4e/0x53
dump_stack_lvl+0x51/0x66
print_address_description.constprop.0.cold+0xea/0x41e
print_report.cold+0x90/0x205
kasan_report+0xb9/0xf0
__asan_load8+0x69/0x90
srpt_enable_tpg+0x31/0x70 [ib_srpt]
target_fabric_tpg_base_enable_store+0xe2/0x140 [target_core_mod]
configfs_write_iter+0x18b/0x210
new_sync_write+0x1f2/0x2f0
vfs_write+0x3e3/0x540
ksys_write+0xbb/0x140
__x64_sys_write+0x42/0x50
do_syscall_64+0x34/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
</TASK>

Link: https://lore.kernel.org/r/20220727193415.1583860-4-bvanassche@acm.org
Reported-by: Li Zhijian <lizhijian@fujitsu.com>
Tested-by: Li Zhijian <lizhijian@fujitsu.com>
Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/srpt: Introduce a reference count in struct srpt_device

This will be used to keep struct srpt_device around as long as either the
RDMA port exists or a LIO target port is associated with the struct
srpt_device.

Link: https://lore.kernel.org/r/20220727193415.1583860-3-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/srpt: Duplicate port name members

Prepare for decoupling the lifetimes of struct srpt_port and struct
srpt_port_id by duplicating the port name into struct srpt_port.

Link: https://lore.kernel.org/r/20220727193415.1583860-2-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

IB: Fix kernel-doc markups

Some functions have different names between their prototypes and the
kernel-doc markup.

Others need to be fixed, as kernel-doc markups should use this format:
identifier - description

Link: https://lore.kernel.org/r/78b98c41a5a0f4c0106433d305b143028a4168b0.1606823973.git.mchehab+huawei@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

IB/srpt: docs: add a description for cq_size member

Changeset c804af2c1d31 ("IB/srpt: use new shared CQ mechanism")
added a new member for struct srpt_rdma_ch, but didn't add the
corresponding kernel-doc markup, as repoted when doing
"make htmldocs":

./drivers/infiniband/ulp/srpt/ib_srpt.h:331: warning: Function parameter or member 'cq_size' not described in 'srpt_rdma_ch'

Add a description for it.

Fixes: c804af2c1d31 ("IB/srpt: use new shared CQ mechanism")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Link: https://lore.kernel.org/r/df0e5f0e866b91724299ef569a2da8115e48c0cf.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

IB/srpt: use new shared CQ mechanism

Have the driver use shared CQs provided by the rdma core driver. This
provides the advantage of improved efficiency handling interrupts.

Link: https://lore.kernel.org/r/20200722135629.49467-3-maxg@mellanox.com
Signed-off-by: Yamin Friedman <yaminf@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/srpt: Increase max_send_sge

The ib_srpt driver limits max_send_sge to 16. Since that is a workaround
for an mlx4 bug that has been fixed, increase max_send_sge. See also
commit f95ccffc715b ("IB/mlx4: Use 4K pages for kernel QP's WQE buffer").

Link: https://lore.kernel.org/r/20200525172212.14413-5-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srpt: Fix TPG creation

Unlike the iSCSI target driver, for the SRP target driver it is sufficient
if a single TPG can be associated with each RDMA port name. However, users
started associating multiple TPGs with RDMA port names. Support this by
converting the single TPG in struct srpt_port_id into a list. This patch
fixes the following list corruption issue:

list_add corruption. prev->next should be next (ffffffffc0a080c0), but was ffffa08a994ce6f0. (prev=ffffa08a994ce6f0).
WARNING: CPU: 2 PID: 2597 at lib/list_debug.c:28 __list_add_valid+0x6a/0x70
CPU: 2 PID: 2597 Comm: targetcli Not tainted 5.4.0-rc1.3bfa3c9602a7 #1
RIP: 0010:__list_add_valid+0x6a/0x70
Call Trace:
core_tpg_register+0x116/0x200 [target_core_mod]
srpt_make_tpg+0x3f/0x60 [ib_srpt]
target_fabric_make_tpg+0x41/0x290 [target_core_mod]
configfs_mkdir+0x158/0x3e0
vfs_mkdir+0x108/0x1a0
do_mkdirat+0x77/0xe0
do_syscall_64+0x55/0x1d0
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Link: https://lore.kernel.org/r/20191023204106.23326-1-bvanassche@acm.org
Reported-by: Honggang LI <honli@redhat.com>
Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

infiniband: fix ulp/srpt/ib_srpt.h kernel-doc notation

Fix kernel-doc warnings (typos or renames) in ib_srpt.h:

../drivers/infiniband/ulp/srpt/ib_srpt.h:419: warning: Function parameter or member 'port_guid_id' not described in 'srpt_port'
../drivers/infiniband/ulp/srpt/ib_srpt.h:419: warning: Function parameter or member 'port_gid_id' not described in 'srpt_port'

Link: https://lore.kernel.org/r/20191010035239.950150496@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>

RDMA/srpt: Make the code for handling port identities more systematic

Introduce a new data structure for the information about an RDMA port
name. This patch does not change any functionality.

Link: https://lore.kernel.org/r/20190930231707.48259-15-bvanassche@acm.org
Cc: Honggang LI <honli@redhat.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srpt: Rework the code that waits until an RDMA port is no longer in use

The current implementation does not wait until srpt_release_channel()
has finished and hence can trigger a use-after-free. Rework
srpt_release_sport() such that it waits until srpt_release_channel()
has finished. This patch fixes the following KASAN complaint:

==================================================================
BUG: KASAN: use-after-free in srpt_free_ioctx.part.23+0x42/0x100 [ib_srpt]
Read of size 8 at addr ffff888115c71100 by task kworker/4:3/807

CPU: 4 PID: 807 Comm: kworker/4:3 Not tainted 5.3.0-dbg+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Workqueue: events srpt_release_channel_work [ib_srpt]
Call Trace:
dump_stack+0x86/0xca
print_address_description+0x74/0x32d
__kasan_report.cold.6+0x1b/0x36
kasan_report+0x12/0x17
__asan_load8+0x54/0x90
srpt_free_ioctx.part.23+0x42/0x100 [ib_srpt]
srpt_free_ioctx_ring.part.24+0x50/0x80 [ib_srpt]
srpt_release_channel_work+0x2ad/0x390 [ib_srpt]
process_one_work+0x51a/0xa60
worker_thread+0x67/0x5b0
kthread+0x1dc/0x200
ret_from_fork+0x24/0x30

Allocated by task 984:
save_stack+0x21/0x90
__kasan_kmalloc.constprop.9+0xc7/0xd0
kasan_kmalloc+0x9/0x10
__kmalloc+0x153/0x370
srpt_add_one+0x4f/0x570 [ib_srpt]
add_client_context+0x251/0x290 [ib_core]
ib_register_client+0x1da/0x220 [ib_core]
iblock_get_alignment_offset_lbas+0x6b/0x100 [target_core_iblock]
do_one_initcall+0xcd/0x43a
do_init_module+0x103/0x380
load_module+0x3b77/0x3eb0
__do_sys_finit_module+0x12d/0x1b0
__x64_sys_finit_module+0x43/0x50
do_syscall_64+0x6b/0x2d0
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 1128:
save_stack+0x21/0x90
__kasan_slab_free+0x139/0x190
kasan_slab_free+0xe/0x10
slab_free_freelist_hook+0x67/0x1e0
kfree+0xcb/0x2a0
srpt_remove_one+0x569/0x5b0 [ib_srpt]
remove_client_context+0x9a/0xe0 [ib_core]
disable_device+0x106/0x1b0 [ib_core]
__ib_unregister_device+0x5f/0xf0 [ib_core]
ib_unregister_device_and_put+0x48/0x60 [ib_core]
nldev_dellink+0x120/0x180 [ib_core]
rdma_nl_rcv+0x287/0x480 [ib_core]
netlink_unicast+0x2cc/0x370
netlink_sendmsg+0x3b1/0x630
__sys_sendto+0x1db/0x290
__x64_sys_sendto+0x80/0xa0
do_syscall_64+0x6b/0x2d0
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888115c71100
which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 0 bytes inside of
4096-byte region [ffff888115c71100, ffff888115c72100)
The buggy address belongs to the page:
page:ffffea0004571c00 refcount:1 mapcount:0 mapping:ffff88811ac0de00 index:0xffff888115c70000 compound_mapcount: 0
flags: 0x2fff000000010200(slab|head)
raw: 2fff000000010200 ffffea00045ac408 ffffea0004593208 ffff88811ac0de00
raw: ffff888115c70000 0000000000070002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff888115c71000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888115c71080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888115c71100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888115c71180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888115c71200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Link: https://lore.kernel.org/r/20190930231707.48259-14-bvanassche@acm.org
Cc: Honggang LI <honli@redhat.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srpt: Rework the approach for closing an RDMA channel

Instead of relying on a waitqueue, report when the identity of an RDMA
channel can be reused through a completion.

Link: https://lore.kernel.org/r/20190930231707.48259-13-bvanassche@acm.org
Cc: Honggang LI <honli@redhat.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

scsi: RDMA/srpt: Rework I/O context allocation

Instead of maintaining a list of free I/O contexts, use an sbitmap data
structure to track which I/O contexts are in use and which are free. This
makes the ib_srpt driver more consistent with other LIO drivers.

Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

RDMA/srpt: Add support for immediate data

Modify allocation of the non-SRQ receive queues such that immediate
data is aligned on a 512 byte boundary. That alignment is necessary
to pass the immediate data without copying to the block layer. When
receiving an SRP_CMD with immediate data, postpone the ib_post_recv()
call until target_execute_cmd() has finished. See also
srpt_release_cmd().

Cc: Sergey Gorenko <sergeygo@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/srpt: Make kernel-doc headers complete

Add documentation for those structure members for which it is missing.

Cc: Sergey Gorenko <sergeygo@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/srpt: Improve coding style conformance

Use tabs instead of spaces for indentation. Make sure that multi-line
expressions have the operator at the end of a line instead of the start.
Avoid a complaint about a missing space in a ternary expression by
changing '(boolean) ? 1: 0' into 'boolean'.

Cc: Sergey Gorenko <sergeygo@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

include/scsi/srp.h: Move response flag definitions into this file

This patch moves all constants that come from the SRP standard into the
include/scsi/srp.h header file.

Cc: Sergey Gorenko <sergeygo@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Support HCAs with more than two ports

Since there are adapters that have four ports, increase the size of
the srpt_device.port[] array. This patch avoids that the following
warning is hit with quad port Chelsio adapters:

WARN_ON(sdev->device->phys_port_cnt > ARRAY_SIZE(sdev->port));

Reported-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: <stable@vger.kernel.org>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srpt: Add RDMA/CM support

Add a parameter for configuring the port on which the ib_srpt driver
listens for incoming RDMA/CM connections, namely
/sys/kernel/config/target/srpt/discovery_auth/rdma_cm_port. The default
value for this parameter is 0 which means "do not listen for incoming
RDMA/CM connections". Add RDMA/CM support to all code that handles
connection state changes. Modify srpt_init_nodeacl() such that ACLs can
be configured for IPv4 and IPv6 addresses.

Note: incoming connection requests are only accepted for ports that
have been enabled. See also the "if (!sport->enabled)" code in the
connection request handler. See also the following configfs attribute:
/sys/kernel/config/target/srpt/$port/$port/enable.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Preparations for adding RDMA/CM support

Introduce a union in struct srpt_rdma_ch for member variables that
depend on the type of connection manager. Avoid that error messages
report the IB/CM ID.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Don't allow reordering of commands on wait list

If a receive I/O context is removed from the wait list and
srpt_handle_new_iu() fails to allocate a send I/O context then
re-adding the receive I/O context to the wait list can cause
reordering. Avoid this by only removing a receive I/O context
from the wait list after allocating a send I/O context succeeded.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Rework multi-channel support

Store initiator and target port ID's once per nexus instead of in each
channel data structure. This change simplifies the duplicate connection
check in srpt_cm_req_recv().

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Use the source GID as session name

Use the source GID as session name instead of the initiator port ID
from the SRP login request. The only functional change in this patch
is that it changes the session name shown in debug messages.

Note: the fifth argument that is passed to target_alloc_session() is
what the SCSI target core uses as key for lookups in the ACL (access
control list) information.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: One target per port

In multipathing setups where a target system is equipped with
dual-port HCAs it is useful to have one connection per target port
instead of one connection per target HCA. Hence move the connection
list (rch_list) from struct srpt_device into struct srpt_port.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Add P_Key support

Process connection requests that use another P_Key than the default
correctly.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Rework srpt_disconnect_ch_sync()

This patch fixes a use-after-free issue for ch->release_done when
running the SRP protocol on top of the rdma_rxe driver.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Make it safe to use RCU for srpt_device.rch_list

The next patch will iterate over rch_list from a context from which
it is not allowed to block. Hence make rch_list RCU-safe.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Micro-optimize I/O context state manipulation

Since all I/O context state changes are already serialized, it is
not necessary to protect I/O context state changes with the I/O
context spinlock. Hence remove that spinlock.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Rename a local variable, a member variable and a constant

Rename rsp_size into max_rsp_size and SRPT_RQ_SIZE into MAX_SRPT_RQ_SIZE.
The new names better reflect the role of this member variable and constant.
Since the prefix "srp_" is superfluous in the context of the function
that creates an RDMA channel, rename srp_sq_size into sq_size.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Document all structure members in ib_srpt.h

This patch avoids that the following command reports any warnings:

scripts/kernel-doc -none drivers/infiniband/ulp/srpt/ib_srpt.h

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Remove an unused structure member

Fixes: commit a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Change default behavior from using SRQ to using RC

Although in the RC mode more resources are needed that mode has three
advantages over SRQ:
- It works with all RDMA adapters, even those that do not support
SRQ.
- Posting WRs and polling WCs does not trigger lock contention
because only one thread at a time accesses a WR or WC queue in
non-SRQ mode.
- The end-to-end flow control mechanism is used.

>From the IB spec:

C9-150.2.1: For QPs that are not associated with an SRQ, each HCA
receive queue shall generate end-to-end flow control credits. If
a QP is associated with an SRQ, the HCA receive queue shall not
generate end-to-end flow control credits.

Add new configfs attributes that allow to configure which mode to use
(/sys/kernel/config/target/srpt/$GUID/$GUID/attrib/use_srq). Note:
only the attribute for port 1 is relevant on multi-port adapters.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Cache global L_Key

This patch is a micro-optimization for the hot path.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Increase lid and sm_lid to 32 bits

srpt contains lid and sm_lid fields which are 16 bits in
length, increase them to 32 bits.

Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Accept GUIDs as port names

Port and ACL information must be configured before an initiator
logs in. Make it possible to configure this information before
a subnet prefix has been assigned to a port by not only accepting
GIDs as target port and initiator port names but by also accepting
port GUIDs.

Add a 'priv' member to struct se_wwn to allow target drivers to
associate their own data with struct se_wwn.

Reported-by: Doug Ledford <dledford@redhat.com>
References: http://www.spinics.net/lists/linux-rdma/msg39505.html
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Limit the number of SG elements per work request

Limit the number of SG elements per work request to what the HCA
and the queue pair support.

Fixes: 34693573fde0 ("IB/srpt: Reduce QP buffer size")
Reported-by: Parav Pandit <pandit.parav@gmail.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Parav Pandit <pandit.parav@gmail.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: <stable@vger.kernel.org> #v4.7+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Reduce QP buffer size

The memory needed for the send and receive queues associated with
a QP is proportional to the max_sge parameter. The current value
of that parameter is such that with an mlx4 HCA the QP buffer size
is 8 MB. Since DMA is used for communication between HCA and CPU
that buffer either has to be allocated coherently or map_single()
must succeed for that buffer. Since large contiguous allocations
are fragile and since the maximum segment size for e.g. swiotlb
is 256 KB, reduce the max_sge parameter. This patch avoids that
the following text appears on the console after SRP logout and
relogin on a system equipped with multiple IB HCAs:

mlx4_core 0000:05:00.0: swiotlb buffer is full (sz: 8388608 bytes)
swiotlb: coherent allocation failed for device 0000:05:00.0 size=8388608
CPU: 11 PID: 148 Comm: kworker/11:1 Not tainted 4.7.0-rc4-dbg+ #1
Call Trace:
[<ffffffff812c6d35>] dump_stack+0x67/0x92
[<ffffffff812efe71>] swiotlb_alloc_coherent+0x141/0x150
[<ffffffff810458be>] x86_swiotlb_alloc_coherent+0x3e/0x50
[<ffffffffa03861fa>] mlx4_buf_direct_alloc.isra.5+0x9a/0x120 [mlx4_core]
[<ffffffffa0386545>] mlx4_buf_alloc+0x165/0x1a0 [mlx4_core]
[<ffffffffa035053d>] create_qp_common.isra.29+0x57d/0xff0 [mlx4_ib]
[<ffffffffa03510da>] mlx4_ib_create_qp+0x12a/0x3f0 [mlx4_ib]
[<ffffffffa031154a>] ib_create_qp+0x3a/0x250 [ib_core]
[<ffffffffa055dd4b>] srpt_cm_handler+0x4bb/0xcad [ib_srpt]
[<ffffffffa02c1ab0>] cm_process_work+0x20/0xf0 [ib_cm]
[<ffffffffa02c3640>] cm_work_handler+0x1ac0/0x2059 [ib_cm]
[<ffffffff810737ed>] process_one_work+0x19d/0x490
[<ffffffff81073b29>] worker_thread+0x49/0x490
[<ffffffff8107a0ea>] kthread+0xea/0x100
[<ffffffff815b25af>] ret_from_fork+0x1f/0x40

Fixes: b99f8e4d7bcd ("IB/srpt: convert to the generic RDMA READ/WRITE API")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: convert to the generic RDMA READ/WRITE API

Replace the homegrown RDMA READ/WRITE code in srpt with the generic API.
The only real twist here is that we need to allocate one Linux scatterlist
per direct buffer in the SRP command, and chain them before handing them
off to the target core.

As a side-effect of the conversion the driver will also chain the SEND
of the SRP response to the RDMA WRITE WRs for a DATA OUT command, and
properly account for RDMA WRITE WRs instead of just for RDMA READ WRs
like the driver previously did.

We now allocate half of the SQ size to RDMA READ/WRITE contexts, assuming
by default one RDMA READ or WRITE operation per command. If a command
has multiple operations it will eat into the budget but will still succeed,
possible after waiting for WQEs to be available.

Also ensure the QPs request the maximum allowed SGEs so that RDMA R/W API
works correctly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

Revert "ib_srpt: Convert to percpu_ida tag allocation"

This reverts commit 0fd10721fe3664f7549e74af9d28a509c9a68719.

That patch causes the ib_srpt driver to crash as soon as the first SCSI
command is received:

kernel BUG at drivers/infiniband/ulp/srpt/ib_srpt.c:1439!
invalid opcode: 0000 [#1] SMP
Workqueue: target_completion target_complete_ok_work [target_core_mod]
RIP: srpt_queue_response+0x437/0x4a0 [ib_srpt]
Call Trace:
srpt_queue_data_in+0x9/0x10 [ib_srpt]
target_complete_ok_work+0x152/0x2b0 [target_core_mod]
process_one_work+0x197/0x480
worker_thread+0x49/0x490
kthread+0xea/0x100
ret_from_fork+0x22/0x40

Aside from the crash, the shortcomings of that patch are as follows:

- It makes the ib_srpt driver use I/O contexts allocated by
transport_alloc_session_tags() but it does not initialize these I/O
contexts properly. All the initializations performed by
srpt_alloc_ioctx() are skipped.

- It swaps the order of the send ioctx allocation and the transition to
RTR mode which is wrong.

- The amount of memory that is needed for I/O contexts is doubled.

- srpt_rdma_ch.free_list is no longer used but is not removed.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ib_srpt: Convert to percpu_ida tag allocation

This patch converts ib_srpt to use existing percpu_ida tag
pre-allocation for struct srpt_send_ioctx.

This allows ib_srpt to drop it's internal pre-allocation
mechanisms with the extra spin_lock_irqsave, and use
percpu_ida common code for doing this.

Cc: Vu Pham <vu@mellanox.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

IB/srpt: Detect session shutdown reliably

The Last WQE Reached event is only generated after one or more work
requests have been queued on the QP associated with a session. Since
session shutdown can start before any work requests have been queued,
use a zero-length RDMA write to wait until a QP has been drained.

Additionally, rework the code for closing and disconnecting a session.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Alex Estrin <alex.estrin@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Use a mutex to protect the channel list

In a later patch a function that can block will be called while
iterating over the rch_list. Hence protect that list with a
mutex instead of a spinlock. And since it is not allowed to sleep
while the task state != TASK_RUNNING, convert the list test in
srpt_ch_list_empty() into a lockless test.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Alex Estrin <alex.estrin@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Simplify srpt_shutdown_session()

The target core guarantees that shutdown_session() is only invoked
once per session. This means that the ib_srpt target driver doesn't
have to track whether or not shutdown_session() has been called.
Additionally, ensure that target_sess_cmd_list_set_waiting() is
called before target_wait_for_sess_cmds() by moving it into
srpt_release_channel_work().

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Alex Estrin <alex.estrin@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Remove struct srpt_node_acl

Since struct srpt_node_acl is identical to struct se_node_acl,
remove the definition of the former structure. This patch does
not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Estrin <alex.estrin@intel.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: Remove redundant wc array

No usage after the conversion to the new CQ API.

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

ib_srpt: Convert acl lookup to modern get_initiator_node_acl usage

This patch does a simple conversion of ib_srpt code to use
proper modern core_tpg_get_initiator_node_acl() lookup using
se_node_acl->acl_kref, and drops the legacy internal list
usage from srpt_lookup_acl().

This involves doing transport_init_session() earlier, and
making sure transport_free_session() is called during
a se_node_acl lookup failure to drop the last ->acl_kref.

Also, it adds a minor backwards-compat hack to avoid the
potential for user-space wrt node-acl WWPN formatting by
simply stripping off '0x' prefix from ch->sess_name, and
retrying once if core_tpg_get_initiator_node_acl() fails.

Finally, go ahead and drop port_acl_list port_acl_lock
since they are no longer used.

Cc: Vu Pham <vu@mellanox.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

IB/ulps: Avoid calling ib_query_device

Instead, use the cached copy of the attributes present on the device.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srpt: chain RDMA READ/WRITE requests

Remove struct rdma_iu and instead allocate the struct ib_rdma_wr array
early and fill out directly. This allows us to chain the WRs, and thus
archives both less lock contention on the HCA workqueue as well as much
simpler error handling.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>

ib_srpt: Remove ib_get_dma_mr calls

The pd now has a local_dma_lkey member which completely replaces
ib_get_dma_mr, use it instead.

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

target: Minimize SCSI header #include directives

Only include SCSI initiator header files in target code that needs
these header files, namely the SCSI pass-through code and the tcm_loop
driver. Change SCSI_SENSE_BUFFERSIZE into TRANSPORT_SENSE_BUFFER in
target code because the former is intended for initiator code and the
latter for target code. With this patch the only initiator include
directives in target code that remain are as follows:

$ git grep -nHE 'include .scsi/(scsi.h|scsi_host.h|scsi_device.h|scsi_cmnd.h)' drivers/target drivers/infiniband/ulp/{isert,srpt} drivers/usb/gadget/legacy/tcm_*.[ch] drivers/{vhost,xen} include/{target,trace/events/target.h}
drivers/target/loopback/tcm_loop.c:29:#include <scsi/scsi.h>
drivers/target/loopback/tcm_loop.c:31:#include <scsi/scsi_host.h>
drivers/target/loopback/tcm_loop.c:32:#include <scsi/scsi_device.h>
drivers/target/loopback/tcm_loop.c:33:#include <scsi/scsi_cmnd.h>
drivers/target/target_core_pscsi.c:39:#include <scsi/scsi_device.h>
drivers/target/target_core_pscsi.c:40:#include <scsi/scsi_host.h>
drivers/xen/xen-scsiback.c:52:#include <scsi/scsi_host.h> /* SG_ALL */

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

target: Move task tag into struct se_cmd + support 64-bit tags

Simplify target core and target drivers by storing the task tag
a.k.a. command identifier inside struct se_cmd.

For several transports (e.g. SRP) tags are 64 bits wide.
Hence add support for 64-bit tags.

(Fix core_tmr_abort_task conversion spec warnings - nab)
(Fix up usb-gadget to use 16-bit tags - HCH + bart)

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: <qla2xxx-upstream@qlogic.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: move transport ID handling to the core

Now that struct se_portal_group contains a protocol identifier field we can
take all the code to format an parse protocol identifiers in CDBs into common
code instead of leaving this to low-level drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: move node ACL allocation to core code

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

ib_srpt: Call target_sess_cmd_list_set_waiting during shutdown_session

Given that srpt_release_channel_work() calls target_wait_for_sess_cmds()
to allow outstanding se_cmd_t->cmd_kref a change to complete, the call
to perform target_sess_cmd_list_set_waiting() needs to happen in
srpt_shutdown_session()

Also, this patch adds an explicit call to srpt_shutdown_session() within
srpt_drain_channel() so that target_sess_cmd_list_set_waiting() will be
called in the cases where TFO->shutdown_session() is not triggered
directly by TCM.

Cc: Joern Engel <joern@logfs.org>
Cc: Roland Dreier <roland@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

ib_srpt: Convert I/O path to target_submit_cmd + drop legacy ioctx->kref

This patch converts the main srpt_handle_cmd() I/O path to use modern
target_submit_cmd() with TARGET_SCF_ACK_KREF flag usage. This includes
dropping the original internal ioctx->kref + srpt_put_send_ioctx() usage
in favor of target_put_sess_cmd() w/ se_cmd_t->cmd_kref within ib_srpt
response callbacks.

It also updates srpt_abort_cmd() to call target_put_sess_cmd() for
completion of aborted commands, and adds target_wait_for_sess_cmds() into
srpt_release_channel_work() to allow outstanding I/O to complete during
session shutdown.

Also, go ahead and update srpt_handle_tsk_mgmt() to make the remaining
transport_init_se_cmd() to setup the ioctx->cmd with se_tmr_req.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

IB/srpt: Remove unneeded <linux/version.h> include

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Roland Dreier <roland@purestorage.com>

ib_srpt: Initial SRP Target merge for v3.3-rc1

This patch adds the kernel module ib_srpt SCSI RDMA Protocol (SRP) target
implementation conforming to the SRP r16a specification for the mainline
drivers/target infrastructure.

This driver was originally developed by Vu Pham and has been optimized by
Bart Van Assche and merged into upstream LIO based on his srpt-lio-4.1
branch here:

https://github.com/bvanassche/srpt-lio/commits/srpt-lio-4.1/

This updated patch also contains the following two changes from
lio-core-2.6.git/master. One is to fix a bug with 1 >= task->task_sg[]
chained mappings in ib_srpt, and the other to convert the configfs control
plane to reference IB Port GUID and struct srpt_port directly following
mainline v4.x target_core_fabric_configfs.c convertion for ib_srpt
to work with rtslib/rtsadmin v2 code.

These seperate patches can be found here:

ib_srpt: Fix bug with chainged SGLs in srpt_map_sg_to_ib_sge
http://www.risingtidesystems.com/git/?p=lio-core-2.6.git;a=commitdiff;h=ea485147563b6555a97dbf811825fbb586519252

ib_srpt: Convert se_wwn endpoint reference to struct srpt_port->port_wwn
http://www.risingtidesystems.com/git/?p=lio-core-2.6.git;a=commitdiff;h=4e544a210acb227df1bb4ca5086e65bdf4e648ea

This also includes the following recent v1 -> v2 review changes:

ib_srpt: Fix potential out-of-bounds array access
ib_srpt: Avoid failed multipart RDMA transfers
ib_srpt: Fix srpt_alloc_fabric_acl failure case return value
ib_srpt: Update comments to reference $driver/$port layout
ib_srpt: Fix sport->port_guid formatting code
ib_srpt: Remove legacy use_port_guid_in_session_name module parameter
ib_srpt: Convert srp_max_rdma_size into per port configfs attribute
ib_srpt: Convert srp_max_rsp_size into per port configfs attribute
ib_srpt: Convert srpt_sq_size into per port configfs attribute

and v2 -> v3 review changes:

ib_srpt: Fix possible race with srp_sq_size in srpt_create_ch_ib
ib_srpt: Fix possible race with srp_max_rsp_size in srpt_release_channel_work
ib_srpt: Fix up MAX_SRPT_RDMA_SIZE define
ib_srpt: Make srpt_map_sg_to_ib_sge() failure case return -EAGAIN
ib_srpt: Convert port_guid to use subnet_prefix + interface_id formatting
ib_srpt: Make srpt_check_stop_free return kref_put status
ib_srpt: Make compilation with BUG=n proceed`
ib_srpt: Use new target_core_fabric.h include
ib_srpt: Check hex2bin() return code to silence build warning

Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Vu Pham <vu@mellanox.com>
Cc: David Dillow <dillowda@ornl.gov>
Signed-off-by: Nicholas A. Bellinger <nab@risingtidesystems.com>