RDMA/srp: Do not call scsi_done() from srp_abort()

After scmd_eh_abort_handler() has called the SCSI LLD eh_abort_handler
callback, it performs one of the following actions:
* Call scsi_queue_insert().
* Call scsi_finish_command().
* Call scsi_eh_scmd_add().
Hence, SCSI abort handlers must not call scsi_done(). Otherwise all
the above actions would trigger a use-after-free. Hence remove the
scsi_done() call from srp_abort(). Keep the srp_free_req() call
before returning SUCCESS because we may not see the command again if
SUCCESS is returned.

Cc: Bob Pearson <rpearsonhpe@gmail.com>
Cc: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: d8536670916a ("IB/srp: Avoid having aborted requests hang")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230823205727.505681-1-bvanassche@acm.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>

scsi: RDMA/srp: Fix residual handling

Although the code for residual handling in the SRP initiator follows the
SCSI documentation, that documentation has never been correct. Because
scsi_finish_command() starts from the data buffer length and subtracts the
residual, scsi_set_resid() must not be called if a residual overflow
occurs. Hence remove the scsi_set_resid() calls from the SRP initiator if a
residual overflow occurrs.

Cc: Leon Romanovsky <leon@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Fixes: 9237f04e12cc ("scsi: core: Fix scsi_get/set_resid() interface")
Fixes: e714531a349f ("IB/srp: Fix residual handling")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230724200843.3376570-3-bvanassche@acm.org
Acked-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

dyndbg: cleanup dynamic usage in ib_srp.c

Currently, in dynamic_debug.h we only provide
DEFINE_DYNAMIC_DEBUG_METADATA() and DYNAMIC_DEBUG_BRANCH()
definitions if CONFIG_DYNAMIC_CORE is enabled. Thus, drivers
such as infiniband srp (see: drivers/infiniband/ulp/srp/ib_srp.c)
must provide their own definitions for !CONFIG_DYNAMIC_CORE.

Thus, let's move this !CONFIG_DYNAMIC_CORE case into dynamic_debug.h.
However, the dynamic debug interfaces should really only be defined
if CONFIG_DYNAMIC_DEBUG is set or CONFIG_DYNAMIC_CORE is set along
with DYNAMIC_DEBUG_MODULE, (see:
Documentation/admin-guide/dynamic-debug-howto.rst). Thus, the
undefined case becomes: !((CONFIG_DYNAMIC_DEBUG ||
(CONFIG_DYNAMIC_CORE && DYNAMIC_DEBUG_MODULE)).
With those changes in place, we can remove the !CONFIG_DYNAMIC_CORE
case from ib_srp.c

This change was prompted by a build breakeage in ib_srp.c stemming
from the inclusion of dynamic_debug.h unconditionally in module.h, due
to commit 7deabd674988 ("dyndbg: use the module notifier callbacks").
In that case, if we have CONFIG_DYNAMIC_CORE=y and
CONFIG_DYNAMIC_DEBUG=n then the definitions for
DEFINE_DYNAMIC_DEBUG_METADATA() and DYNAMIC_DEBUG_BRANCH() are defined
once in ib_srp.c and then again in the dynamic_debug.h. This had been
working prior to the above referenced commit because dynamic_debug.h
was only pulled into ib_srp.c conditinally via printk.h if
CONFIG_DYNAMIC_DEBUG was set.

Also, the exported functions in lib/dynamic_debug.c itself may
not have a prototype if CONFIG_DYNAMIC_DEBUG=n and
CONFIG_DYNAMIC_CORE=y. This would trigger the -Wmissing-prototypes
warning.

The exported functions are behind (include/linux/dynamic_debug.h):

if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))

Thus, by adding -DDYNAMIC_CONFIG_MODULE to the lib/Makefile we
can ensure that the exported functions have a prototype in all cases,
since lib/dynamic_debug.c is built whenever
CONFIG_DYNAMIC_DEBUG_CORE=y.

Fixes: 7deabd674988 ("dyndbg: use the module notifier callbacks")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202303071444.sIbZTDCy-lkp@intel.com/
Signed-off-by: Jason Baron <jbaron@akamai.com>
[mcgrof: adjust commit log, and remove urldefense from URL]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

scsi: RDMA/srp: Declare the SCSI host template const

Make it explicit that the SRP host template is not modified.

Acked-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230322195515.1267197-7-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

RDMA/cma: Refactor the inbound/outbound path records process flow

Refactors based on comments [1] of the multiple path records support
patchset:
- Return failure if not able to set inbound/outbound PRs;
- Simplify the flow when receiving the PRs from netlink channel: When
a good PR response is received, unpack it and call the path_query
callback directly. This saves two memory allocations;
- Define RDMA_PRIMARY_PATH_MAX_REC_NUM in a proper place.

[1] https://lore.kernel.org/linux-rdma/Yyxp9E9pJtUids2o@nvidia.com/

Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org> #srp
Link: https://lore.kernel.org/r/7610025d57342b8b6da0f19516c9612f9c3fdc37.1672819376.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/srp: Fix error return code in srp_parse_options()

In the previous iteration of the while loop, the "ret" may have been
assigned a value of 0, so the error return code -EINVAL may have been
incorrectly set to 0. To fix set valid return code before calling to
goto. Also investigate each case separately as Andy suggessted.

Fixes: e711f968c49c ("IB/srp: replace custom implementation of hex2bin()")
Fixes: 2a174df0c602 ("IB/srp: Use kstrtoull() instead of simple_strtoull()")
Fixes: 19f313438c77 ("IB/srp: Add RDMA/CM support")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Link: https://lore.kernel.org/r/1669953638-11747-2-git-send-email-wangyufen@huawei.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/srp: Support more than 255 rdma ports

Currently ib_srp module does not support devices with more than 256
ports. Switch from u8 to u32 to fix the problem.

Fixes: 1fb7f8973f51 ("RDMA: Support more than 255 rdma ports")
Reviewed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Mikhael Goikhman <migo@nvidia.com>
Link: https://lore.kernel.org/r/7d80d8844f1abb3a54170b7259f0a02be38080a6.1663747327.git.leonro@nvidia.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/cma: Multiple path records support with netlink channel

Support receiving inbound and outbound IB path records (along with GMP
PathRecord) from user-space service through the RDMA netlink channel.
The LIDs in these 3 PRs can be used in this way:
1. GMP PR: used as the standard local/remote LIDs;
2. DLID of outbound PR: Used as the "dlid" field for outbound traffic;
3. DLID of inbound PR: Used as the "dlid" field for outbound traffic in
responder side.

This is aimed to support adaptive routing. With current IB routing
solution when a packet goes out it's assigned with a fixed DLID per
target, meaning a fixed router will be used.
The LIDs in inbound/outbound path records can be used to identify group
of routers that allow communication with another subnet's entity. With
them packets from an inter-subnet connection may travel through any
router in the set to reach the target.

As confirmed with Jason, when sending a netlink request, kernel uses
LS_RESOLVE_PATH_USE_ALL so that the service knows kernel supports
multiple PRs.

Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Link: https://lore.kernel.org/r/2fa2b6c93c4c16c8915bac3cfc4f27be1d60519d.1662631201.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/srp: Fix srp_abort()

Fix the code for converting a SCSI command pointer into an SRP request
pointer.

Cc: Xiao Yang <yangx.jy@fujitsu.com>
Fixes: ad215aaea4f9 ("RDMA/srp: Make struct scsi_cmnd and struct srp_request adjacent")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220908233139.3042628-1-bvanassche@acm.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/srp: Use the attribute group mechanism for sysfs attributes

Simplify the SRP driver by using the attribute group mechanism instead
of calling device_create_file() explicitly.

Link: https://lore.kernel.org/r/20220825213900.864587-5-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/srp: Handle dev_set_name() failure

Instead of ignoring dev_set_name() failure, handle dev_set_name()
failure. Convert a device_register() call into device_initialize() and
device_add() calls.

Link: https://lore.kernel.org/r/20220825213900.864587-4-bvanassche@acm.org
Reported-by: Bo Liu <liubo03@inspur.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/srp: Remove the srp_host.released completion

Move the kfree(host) calls into srp_release_dev(). Convert a
device_unregister() call into a device_del() and a device_put() call.
Remove the host->released completion object. This patch prepares for
handling dev_set_name() failure in srp_add_port().

Link: https://lore.kernel.org/r/20220825213900.864587-3-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/srp: Rework the srp_add_port() error path

device_register() always calls device_initialize() so calling device_del()
is safe even if device_register() fails. Implement the following advice
from the comment block above device_register(): "NOTE: _Never_ directly free
@dev after calling this function, even if it returned an error! Always use
put_device() to give up the reference initialized in this function instead."
Keep the kfree() call in the error path since srp_release_dev() does not
free the host.

Link: https://lore.kernel.org/r/20220825213900.864587-2-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/srp: Set scmnd->result only when scmnd is not NULL

This change fixes the following kernel NULL pointer dereference
which is reproduced by blktests srp/007 occasionally.

BUG: kernel NULL pointer dereference, address: 0000000000000170
PGD 0 P4D 0
Oops: 0002 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 9 Comm: kworker/0:1H Kdump: loaded Not tainted 6.0.0-rc1+ #37
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-29-g6a62e0cb0dfe-prebuilt.qemu.org 04/01/2014
Workqueue: 0x0 (kblockd)
RIP: 0010:srp_recv_done+0x176/0x500 [ib_srp]
Code: 00 4d 85 ff 0f 84 52 02 00 00 48 c7 82 80 02 00 00 00 00 00 00 4c 89 df 4c 89 14 24 e8 53 d3 4a f6 4c 8b 14 24 41 0f b6 42 13 <41> 89 87 70 01 00 00 41 0f b6 52 12 f6 c2 02 74 44 41 8b 42 1c b9
RSP: 0018:ffffaef7c0003e28 EFLAGS: 00000282
RAX: 0000000000000000 RBX: ffff9bc9486dea60 RCX: 0000000000000000
RDX: 0000000000000102 RSI: ffffffffb76bbd0e RDI: 00000000ffffffff
RBP: ffff9bc980099a00 R08: 0000000000000001 R09: 0000000000000001
R10: ffff9bca53ef0000 R11: ffff9bc980099a10 R12: ffff9bc956e14000
R13: ffff9bc9836b9cb0 R14: ffff9bc9557b4480 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff9bc97ec00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 0000000007e04000 CR4: 00000000000006f0
Call Trace:
<IRQ>
__ib_process_cq+0xb7/0x280 [ib_core]
ib_poll_handler+0x2b/0x130 [ib_core]
irq_poll_softirq+0x93/0x150
__do_softirq+0xee/0x4b8
irq_exit_rcu+0xf7/0x130
sysvec_apic_timer_interrupt+0x8e/0xc0
</IRQ>

Fixes: ad215aaea4f9 ("RDMA/srp: Make struct scsi_cmnd and struct srp_request adjacent")
Link: https://lore.kernel.org/r/20220831081626.18712-1-yangx.jy@fujitsu.com
Signed-off-by: Xiao Yang <yangx.jy@fujitsu.com>
Acked-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

blk-mq: Drop 'reserved' arg of busy_tag_iter_fn

We no longer use the 'reserved' arg in busy_tag_iter_fn for any iter
function so it may be dropped.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me> #nvme
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/1657109034-206040-6-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

RDMA: Split kernel-only global device caps from uverbs device caps

Split out flags from ib_device::device_cap_flags that are only used
internally to the kernel into kernel_cap_flags that is not part of the
uapi. This limits the device_cap_flags to being the same bitmap that will
be copied to userspace.

This cleanly splits out the uverbs flags from the kernel flags to avoid
confusion in the flags bitmap.

Add some short comments describing which each of the kernel flags is
connected to. Remove unused kernel flags.

Link: https://lore.kernel.org/r/0-v2-22c19e565eef+139a-kern_caps_jgg@nvidia.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/ib_srp: Fix a deadlock

Remove the flush_workqueue(system_long_wq) call since flushing
system_long_wq is deadlock-prone and since that call is redundant with a
preceding cancel_work_sync()

Link: https://lore.kernel.org/r/20220215210511.28303-3-bvanassche@acm.org
Fixes: ef6c49d87c34 ("IB/srp: Eliminate state SRP_TARGET_DEAD")
Reported-by: syzbot+831661966588c802aae9@syzkaller.appspotmail.com
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

scsi: RDMA/srp: Switch to attribute groups

struct device supports attribute groups directly but does not support
struct device_attribute directly. Hence switch to attribute groups.

Link: https://lore.kernel.org/r/20211012233558.4066756-5-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ib_srp: Call scsi_done() directly

Conditional statements are faster than indirect calls. Hence call
scsi_done() directly.

Link: https://lore.kernel.org/r/20211007202923.2174984-6-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: RDMA/srp: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. This patch does not change any functionality.

Link: https://lore.kernel.org/r/20210809230355.8186-10-bvanassche@acm.org
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Drop obsolete Linux-specific SCSI status codes

Originally the SCSI subsystem has been using 'special' SCSI status codes,
which were the SAM-specified ones but shifted by 1. As most drivers have
now been modified to use the SAM-specified ones, having two nearly
identical sets of definitions only causes confusion.

The Linux-specifed SCSI status codes have been marked obsolete for several
years so drop them and use the SAM-specified status codes throughout.

Link: https://lore.kernel.org/r/20210427083046.31620-41-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

RDMA/srp: Use DEVICE_ATTR_*() macros

Use DEVICE_ATTR_*() helpers instead of plain DEVICE_ATTR, which makes the
code a bit shorter and easier to read.

Link: https://lore.kernel.org/r/20210528125750.20788-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/srp: Make struct scsi_cmnd and struct srp_request adjacent

Define .init_cmd_priv and .exit_cmd_priv callback functions in struct
scsi_host_template. Set .cmd_size such that the SCSI core allocates
per-command private data. Use scsi_cmd_priv() to access that private
data. Remove the req_ring pointer from struct srp_rdma_ch since it is no
longer necessary. Convert srp_alloc_req_data() and srp_free_req_data()
into functions that initialize one instance of the SRP-private command
data. This is a micro-optimization since this patch removes several
pointer dereferences from the hot path.

Note: due to commit e73a5e8e8003 ("scsi: core: Only return started
requests from scsi_host_find_tag()"), it is no longer necessary to protect
the completion path against duplicate responses.

Link: https://lore.kernel.org/r/20210524041211.9480-6-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/srp: Fix a recently introduced memory leak

Only allocate a memory registration list if it will be used and if it will
be freed.

Link: https://lore.kernel.org/r/20210524041211.9480-5-bvanassche@acm.org
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Fixes: f273ad4f8d90 ("RDMA/srp: Remove support for FMR memory registration")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/srp: Add more structure size checks

Before modifying how the __packed attribute is used, add compile time
size checks for the structures that will be modified.

Link: https://lore.kernel.org/r/20210524041211.9480-3-bvanassche@acm.org
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Cc: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/srp: Fix support for unpopulated and unbalanced NUMA nodes

The current code computes a number of channels per SRP target and spreads
them equally across all online NUMA nodes. Each channel is then assigned
a CPU within this node.

In the case of unbalanced, or even unpopulated nodes, some channels do not
get a CPU associated and thus do not get connected. This causes the SRP
connection to fail.

This patch solves the issue by rewriting channel computation and
allocation:

- Drop channel to node/CPU association as it had no real effect on
locality but added unnecessary complexity.

- Tweak the number of channels allocated to reduce CPU contention when
possible:
- Up to one channel per CPU (instead of up to 4 by node)
- At least 4 channels per node, unless ch_count module parameter is
used.

Link: https://lore.kernel.org/r/9cb4d9d3-30ad-2276-7eff-e85f7ddfb411@suse.com
Signed-off-by: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA: Convert various random sprintf sysfs _show uses to sysfs_emit

Manual changes for sysfs_emit as cocci scripts can't easily convert them.

Link: https://lore.kernel.org/r/ecde7791467cddb570c6f6d2c908ffbab9145cac.1602122880.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA: Manual changes for sysfs_emit and neatening

Make changes to use sysfs_emit in the RDMA code as cocci scripts can not
be written to handle _all_ the possible variants of various sprintf family
uses in sysfs show functions.

While there, make the code more legible and update its style to be more
like the typical kernel styles.

Miscellanea:

o Use intermediate pointers for dereferences
o Add and use string lookup functions
o return early when any intermediate call fails so normal return is
at the bottom of the function
o mlx4/mcg.c:sysfs_show_group: use scnprintf to format intermediate strings

Link: https://lore.kernel.org/r/f5c9e4c9d8dafca1b7b70bd597ee7f8f219c31c8.1602122880.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA: Convert sysfs device * show functions to use sysfs_emit()

Done with cocci script:

@@
identifier d_show;
identifier dev, attr, buf;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
return
- sprintf(buf,
+ sysfs_emit(buf,
...);
...>
}

@@
identifier d_show;
identifier dev, attr, buf;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
return
- snprintf(buf, PAGE_SIZE,
+ sysfs_emit(buf,
...);
...>
}

@@
identifier d_show;
identifier dev, attr, buf;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
return
- scnprintf(buf, PAGE_SIZE,
+ sysfs_emit(buf,
...);
...>
}

@@
identifier d_show;
identifier dev, attr, buf;
expression chr;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
return
- strcpy(buf, chr);
+ sysfs_emit(buf, chr);
...>
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
len =
- sprintf(buf,
+ sysfs_emit(buf,
...);
...>
return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
len =
- snprintf(buf, PAGE_SIZE,
+ sysfs_emit(buf,
...);
...>
return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
len =
- scnprintf(buf, PAGE_SIZE,
+ sysfs_emit(buf,
...);
...>
return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
- len += scnprintf(buf + len, PAGE_SIZE - len,
+ len += sysfs_emit_at(buf, len,
...);
...>
return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
expression chr;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
...
- strcpy(buf, chr);
- return strlen(buf);
+ return sysfs_emit(buf, chr);
}

Link: https://lore.kernel.org/r/7f406fa8e3aa2552c022bec680f621e38d1fe414.1602122879.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/srp: 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/2-v3-f58e6669d5d3+2cf-fmr_removal_jgg@mellanox.com
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srp: Make the channel count configurable per target

Increase the flexibility of the SRP initiator driver by making the channel
count configurable per target instead of only providing a kernel module
parameter for configuring the channel count.

Link: https://lore.kernel.org/r/20200525172212.14413-2-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA: Allow ib_client's to fail when add() is called

When a client is added it isn't allowed to fail, but all the client's have
various failure paths within their add routines.

This creates the very fringe condition where the client was added, failed
during add and didn't set the client_data. The core code will then still
call other client_data centric ops like remove(), rename(), get_nl_info(),
and get_net_dev_by_params() with NULL client_data - which is confusing and
unexpected.

If the add() callback fails, then do not call any more client ops for the
device, even remove.

Remove all the now redundant checks for NULL client_data in ops callbacks.

Update all the add() callbacks to return error codes
appropriately. EOPNOTSUPP is used for cases where the ULP does not support
the ib_device - eg because it only works with IB.

Link: https://lore.kernel.org/r/20200421172440.387069-1-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Never use immediate data if it is disabled by a user

Some SRP targets that do not support specification SRP-2, put the garbage
to the reserved bits of the SRP login response. The problem was not
detected for a long time because the SRP initiator ignored those bits. But
now one of them is used as SRP_LOGIN_RSP_IMMED_SUPP. And it causes a
critical error on the target when the initiator sends immediate data.

The ib_srp module has a use_imm_date parameter to enable or disable
immediate data manually. But it does not help in the above case, because
use_imm_date is ignored at handling the SRP login response. The problem is
definitely caused by a bug on the target side, but the initiator's
behavior also does not look correct. The initiator should not use
immediate data if use_imm_date is disabled by a user.

This commit adds an additional checking of use_imm_date at the handling of
SRP login response to avoid unexpected use of immediate data.

Fixes: 882981f4a411 ("RDMA/srp: Add support for immediate data")
Link: https://lore.kernel.org/r/20200115133055.30232-1-sergeygo@mellanox.com
Signed-off-by: Sergey Gorenko <sergeygo@mellanox.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

ib/srp: Add missing new line after displaying fast_io_fail_tmo param

Long-time missing new-line in sysfs output.
Simply add it.

Signed-off-by: Donald Dutile <ddutile@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20191009164937.21989-1-ddutile@redhat.com
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/srp: Calculate max_it_iu_size if remote max_it_iu length available

The default maximum immediate size is too big for old srp clients, which
do not support immediate data.

According to the SRP and SRP-2 specifications, the IOControllerProfile
attributes for SRP target ports contains the maximum initiator to target
iu length.

The maximum initiator to target iu length can be obtained by sending MAD
packets to query subnet manager port and SRP target ports. We should
calculate the max_it_iu_size instead of the default value, when remote
maximum initiator to target iu length available.

Link: https://lore.kernel.org/r/20190927174352.7800-2-honli@redhat.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srp: Add parse function for maximum initiator to target IU size

According to SRP specifications 'srp-r16a' and 'srp2r06',
IOControllerProfile attributes for SRP target port include the maximum
initiator to target IU size.

SRP connection daemons, such as srp_daemon, can get the value from the
subnet manager. The SRP connection daemon can pass this value to kernel.

This patch adds a parse function for it.

Upstream commit [1] enables the kernel parameter, 'use_imm_data', by
default. [1] also use (8 * 1024) as the default value for kernel parameter
'max_imm_data'. With those default values, the maximum initiator to target
IU size will be 8260.

In case the SRPT modules, which include the in-tree 'ib_srpt.ko' module,
do not support SRP-2 'immediate data' feature, the default maximum
initiator to target IU size is significantly smaller than 8260. For
'ib_srpt.ko' module, which built from source before [2], the default
maximum initiator to target IU is 2116.

[1] introduces a regression issue for old srp targets with default kernel
parameters, as the connection will be rejected because of a too large
maximum initiator to target IU size.

[1] commit 882981f4a411 ("RDMA/srp: Add support for immediate data")
[2] commit 5dabcd0456d7 ("RDMA/srpt: Add support for immediate data")

Link: https://lore.kernel.org/r/20190927174352.7800-1-honli@redhat.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srp: Make route resolving error messages more informative

The IPv6 scope ID is essential when setting up an iWARP connection
between IPv6 link-local addresses. Report the scope ID in error messages.

Link: https://lore.kernel.org/r/20190930231707.48259-9-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/srp: Honor the max_send_sge device attribute

Instead of assuming that max_send_sge >= 3, restrict the number of scatter
gather elements to what is supported by the RDMA adapter.

Link: https://lore.kernel.org/r/20190930231707.48259-8-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/srp: Remove two casts

This patch does not change any functionality.

Link: https://lore.kernel.org/r/20190930231707.48259-7-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: IB/srp: set virt_boundary_mask in the scsi host

This ensures all proper DMA layer handling is taken care of by the SCSI
midlayer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: RDMA/srp: Fix a sleep-in-invalid-context bug

The previous patch guarantees that srp_queuecommand() does not get
invoked while reconnecting occurs. Hence remove the code from
srp_queuecommand() that prevents command queueing while reconnecting.
This patch avoids that the following can appear in the kernel log:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747
in_atomic(): 1, irqs_disabled(): 0, pid: 5600, name: scsi_eh_9
1 lock held by scsi_eh_9/5600:
#0: (rcu_read_lock){....}, at: [<00000000cbb798c7>] __blk_mq_run_hw_queue+0xf1/0x1e0
Preemption disabled at:
[<00000000139badf2>] __blk_mq_delay_run_hw_queue+0x78/0xf0
CPU: 9 PID: 5600 Comm: scsi_eh_9 Tainted: G W 4.15.0-rc4-dbg+ #1
Hardware name: Dell Inc. PowerEdge R720/0VWT90, BIOS 2.5.4 01/22/2016
Call Trace:
dump_stack+0x67/0x99
___might_sleep+0x16a/0x250 [ib_srp]
__mutex_lock+0x46/0x9d0
srp_queuecommand+0x356/0x420 [ib_srp]
scsi_dispatch_cmd+0xf6/0x3f0
scsi_queue_rq+0x4a8/0x5f0
blk_mq_dispatch_rq_list+0x73/0x440
blk_mq_sched_dispatch_requests+0x109/0x1a0
__blk_mq_run_hw_queue+0x131/0x1e0
__blk_mq_delay_run_hw_queue+0x9a/0xf0
blk_mq_run_hw_queue+0xc0/0x1e0
blk_mq_start_hw_queues+0x2c/0x40
scsi_run_queue+0x18e/0x2d0
scsi_run_host_queues+0x22/0x40
scsi_error_handler+0x18d/0x5f0
kthread+0x11c/0x140
ret_from_fork+0x24/0x30

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Doug Ledford <dledford@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

RDMA/srp: Accept again source addresses that do not have a port number

The function srp_parse_in() is used both for parsing source address
specifications and for target address specifications. Target addresses
must have a port number. Having to specify a port number for source
addresses is inconvenient. Make sure that srp_parse_in() supports again
parsing addresses with no port number.

Cc: <stable@vger.kernel.org>
Fixes: c62adb7def71 ("IB/srp: Fix IPv6 address parsing")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srp: Rename SRP sysfs name after IB device rename trigger

SRP logic used device name and port index as symlink to relevant
kobject. If the IB device is renamed then the prior name will be re-used
by the next device plugged in and sysfs will panic as SRP will try to
re-use the same name.

mlx5_ib: Mellanox Connect-IB Infiniband driver v5.0-0
sysfs: cannot create duplicate filename '/class/infiniband_srp/srp-mlx5_0-1'
CPU: 3 PID: 1107 Comm: modprobe Not tainted 5.1.0-for-upstream-perf-2019-05-12_15-09-52-87 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
dump_stack+0x5a/0x73
sysfs_warn_dup+0x58/0x70
sysfs_do_create_link_sd.isra.2+0xa3/0xb0
device_add+0x33f/0x660
srp_add_one+0x301/0x4f0 [ib_srp]
add_client_context+0x99/0xe0 [ib_core]
enable_device_and_get+0xd1/0x1b0 [ib_core]
ib_register_device+0x533/0x710 [ib_core]
? mutex_lock+0xe/0x30
__mlx5_ib_add+0x23/0x70 [mlx5_ib]
mlx5_add_device+0x4e/0xd0 [mlx5_core]
mlx5_register_interface+0x85/0xc0 [mlx5_core]
? 0xffffffffa0791000
do_one_initcall+0x4b/0x1cb
? kmem_cache_alloc_trace+0xc6/0x1d0
? do_init_module+0x22/0x21f
do_init_module+0x5a/0x21f
load_module+0x17f2/0x1ca0
? m_show+0x1c0/0x1c0
__do_sys_finit_module+0x94/0xe0
do_syscall_64+0x48/0x120
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f157cce10d9

The module load/unload sequence was used to trigger such kernel panic:
sudo modprobe ib_srp
sudo modprobe -r mlx5_ib
sudo modprobe -r mlx5_core
sudo modprobe mlx5_core

Have SRP track the name of the core device so that it can't have a name
collision.

Fixes: d21943dd19b5 ("RDMA/core: Implement IB device rename function")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA: Add and use rdma_for_each_port

We have many loops iterating over all of the end port numbers on a struct
ib_device, simplify them with a for_each helper.

Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srp: Rework SCSI device reset handling

Since .scsi_done() must only be called after scsi_queue_rq() has
finished, make sure that the SRP initiator driver does not call
.scsi_done() while scsi_queue_rq() is in progress. Although
invoking sg_reset -d while I/O is in progress works fine with kernel
v4.20 and before, that is not the case with kernel v5.0-rc1. This
patch avoids that the following crash is triggered with kernel
v5.0-rc1:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000138
CPU: 0 PID: 360 Comm: kworker/0:1H Tainted: G B 5.0.0-rc1-dbg+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:blk_mq_dispatch_rq_list+0x116/0xb10
Call Trace:
blk_mq_sched_dispatch_requests+0x2f7/0x300
__blk_mq_run_hw_queue+0xd6/0x180
blk_mq_run_work_fn+0x27/0x30
process_one_work+0x4f1/0xa20
worker_thread+0x67/0x5b0
kthread+0x1cf/0x1f0
ret_from_fork+0x24/0x30

Cc: <stable@vger.kernel.org>
Fixes: 94a9174c630c ("IB/srp: reduce lock coverage of command completion")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/core: Remove ib_sg_dma_address() and ib_sg_dma_len()

Keeping single line wrapper functions is not useful. Hence remove the
ib_sg_dma_address() and ib_sg_dma_len() functions. This patch does not
change any functionality.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srp: Increase max_segment_size

The default behavior of the SCSI core is to set the block layer request
queue parameter max_segment_size to 64 KB. That means that elements of
scatterlists are limited to 64 KB. Since RDMA adapters support larger
sizes, increase max_segment_size for the SRP initiator.

Notes:
- The SCSI max_segment_size parameter was introduced in kernel v5.0. See
also commit 50c2e9107f17 ("scsi: introduce a max_segment_size
host_template parameters").
- Some other block drivers already set max_segment_size to UINT_MAX,
e.g. nbd and rbd.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Use struct_size() in kzalloc()

One of the more common cases of allocation size calculations is finding the
size of a structure that has a zero-sized array at the end, along with memory
for some number of elements for that array. For example:

struct foo {
int stuff;
void *entry[];
};

instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can now
use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/srp: Add support for immediate data

Request permission to send immediate data during login. If the SRP
target grants this request, send the payload of write requests <= 8 KB
as immediate data.

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/srp: Rework handling of the maximum information unit length

Move the maximum initiator to target information unit length parameter
from struct srp_target_port into struct srp_rdma_ch. This patch does
not change any functionality but makes the next patch easier to read.

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/srp: Propagate ib_post_send() failures to the SCSI mid-layer

This patch avoids that the SCSI mid-layer keeps retrying forever if
ib_post_send() fails. This was discovered while testing immediate
data support and passing a too large num_sge value to ib_post_send().

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/srp: Handle large SCSI CDBs correctly

Reserve additional space for CDBs that contain more than sixteen bytes
and set the add_cdb_len field for such CDBs as required. From the SRP
standard: "The ADDITIONAL CDB LENGTH field contains the length in
dwords of the ADDITIONAL CDB field."

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/srp: Document srp_parse_in() arguments

This patch avoids that a warning is reported when building with W=1.

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: Add support for immediate data

Add constants and data structures to support immediate data. These
changes conform to SRP2r04.

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>

scsi: flip the default on use_clustering

Most SCSI drivers want to enable "clustering", that is merging of
segments so that they might span more than a single page. Remove the
ENABLE_CLUSTERING define, and require drivers to explicitly set
DISABLE_CLUSTERING to disable this feature.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

RDMA: Start use ib_device_ops

Make all the required change to start use the ib_device_ops structure.

Signed-off-by: Kamal Heib <kamalheib1@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

ib_srp: Remove WARN_ON in srp_terminate_io()

The WARN_ON() is pointless as the rport is placed in SDEV_TRANSPORT_OFFLINE
at that time, so no new commands can be submitted via srp_queuecommand()

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.com>
Acked-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/ulp: Use dev_name instead of ibdev->name

These return the same thing but dev_name is a more conventional use of the
kernel API.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>

IB/srp: Avoid that sg_reset -d ${srp_device} triggers an infinite loop

Use different loop variables for the inner and outer loop. This avoids
that an infinite loop occurs if there are more RDMA channels than
target->req_ring_size.

Fixes: d92c0da71a35 ("IB/srp: Add multichannel support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/cma: Constify path record, ib_cm_event, listen_id pointers

Constify several pointers such as path_rec, ib_cm_event and listen_id
pointers in several functions.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Simplify ib_post_(send|recv|srq_recv)() calls

Instead of declaring and passing a dummy 'bad_wr' pointer, pass NULL
as third argument to ib_post_(send|recv|srq_recv)().

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Remove driver version and release data information

Remove the driver version and release date information because such
information is not relevant for an upstream driver. See also commit
e1267b01240a ("RDMA: Remove useless MODULE_VERSION").

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB: Replace ib_query_gid/ib_get_cached_gid with rdma_query_gid

If the gid_attr argument is NULL then the functions behave identically to
rdma_query_gid. ib_query_gid just calls ib_get_cached_gid, so everything
can be consolidated to one function.

Now that all callers either use rdma_query_gid() or ib_get_cached_gid(),
ib_query_gid() API is removed.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
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/srp: Disallow duplicate RDMA/CM connections

According to the SRP standard the INITIATOR and TARGET PORT IDENTIFIER
fields from the login request specify the I_T nexus. Whether or not an
SRP target closes an existing connection for an I_T nexus when a login
request is received depends on the value of the MULTICHANNEL field in
the login request. The SRP initiator derives the value of the
INITIATOR and TARGET PORT IDENTIFIER fields from the .id_ext,
.ioc_guid, .initiator_ext .sgid members of the srp_target_port
structure. This means that the .rdma_cm.dst check must be removed from
srp_conn_unique(). This patch avoids that for target ports that have
multiple addresses, e.g. an IPv4 and an IPv6 address, and if a
connection is established to both target port addresses, that the
initiator logs in alternatingly every 10 seconds to the other target
port address. An SRP target must namely terminate all but one
connections for a given I_T nexus if the MULTICHANNEL field has not
been set in the login request.

Fixes: 19f313438c77 ("IB/srp: Add RDMA/CM support")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Fix IPv6 address parsing

Split IPv6 addresses at the colon that separates the IPv6 address
and the port number instead of at a colon in the middle of the IPv6
address. Check whether the IPv6 address is surrounded with square
brackets.

Fixes: 19f313438c77 ("IB/srp: Add RDMA/CM support")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Use the IB_DEVICE_SG_GAPS_REG HCA feature if supported

If a HCA supports the SG_GAPS_REG feature then fewer memory regions
are required per command. This patch reduces the number of memory
regions that is allocated per SRP session.

Signed-off-by: Sergey Gorenko <sergeygo@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Use %pIS instead of inet_ntop()

Except for a minor log message change, this patch does not change
any functionality. For the introduction of %pIS, see also commit
1067964305df ("lib: vsprintf: add IPv4/v6 generic %p[Ii]S[pfs]
format specifier").

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Revert "IB/srp: Avoid that a cable pull can trigger a kernel crash"

The caller of srp_ib_lookup_path() is responsible for holding a reference
on the SCSI host. That means that commit 8a0d18c62121 was not necessary.
Hence revert it.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Fix srp_abort()

Before commit e494f6a72839 ("[SCSI] improved eh timeout handler") it
did not really matter whether or not abort handlers like srp_abort()
called .scsi_done() when returning another value than SUCCESS. Since
that commit however this matters. Hence only call .scsi_done() when
returning SUCCESS.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Fix completion vector assignment algorithm

Ensure that cv_end is equal to ibdev->num_comp_vectors for the
NUMA node with the highest index. This patch improves spreading
of RDMA channels over completion vectors and thereby improves
performance, especially on systems with only a single NUMA node.
This patch drops support for the comp_vector login parameter by
ignoring the value of that parameter since I have not found a
good way to combine support for that parameter and automatic
spreading of RDMA channels over completion vectors.

Fixes: d92c0da71a35 ("IB/srp: Add multichannel support")
Reported-by: Alexander Schmid <alex@modula-shop-systems.de>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Alexander Schmid <alex@modula-shop-systems.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Add target_can_queue login parameter

Although I'm not sure this parameter is useful for regular SRP users,
setting this parameter to 1 has shown to be invaluable for testing the
block layer core, SCSI core and device mapper queue running mechanisms.

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

IB/srp: Add RDMA/CM support

Since the SRP_LOGIN_REQ defined in the SRP standard is larger than
what fits in the RDMA/CM login request private data, introduce a new
login request format for the RDMA/CM.

Note: since srp_daemon and ibsrpdm rely on the subnet manager and
since there is no equivalent of the IB subnet manager in non-IB
networks, login has to be performed manually for non-IB networks.

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

IB/srp: Refactor srp_send_req()

This patch does not change any functionality but prepares for the patch
that adds RDMA_CM support by making the RDMA_CM patch much easier to
read.

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

IB/srp: Improve path record query error message

Show all path record query parameters if a path record query fails.

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

IB/srp: Use kstrtoull() instead of simple_strtoull()

Use kstrtoull() since simple_strtoull() is deprecated. This patch
improves error checking but otherwise does not change any functionality.

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

IB/srp: replace custom implementation of hex2bin()

There is no need to have a duplication of the generic library, i.e.
hex2bin().

Replace the open coded variant.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/srp: Make CM timeout dependent on subnet timeout

For small networks it is safe to reduce the subnet timeout from
its default value (18 for opensm) to 16. Make the SRP CM timeout
dependent on the subnet timeout such that decreasing the subnet
timeout also causes SRP failover and failback to occur faster.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Cache global rkey

This 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/srp: Remove second argument of srp_destroy_qp()

This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Avoid that a cable pull can trigger a kernel crash

This patch fixes the following kernel crash:

general protection fault: 0000 [#1] PREEMPT SMP
Workqueue: ib_mad2 timeout_sends [ib_core]
Call Trace:
ib_sa_path_rec_callback+0x1c4/0x1d0 [ib_core]
send_handler+0xb2/0xd0 [ib_core]
timeout_sends+0x14d/0x220 [ib_core]
process_one_work+0x200/0x630
worker_thread+0x4e/0x3b0
kthread+0x113/0x150

Fixes: commit aef9ec39c47f ("IB: Add SCSI RDMA Protocol (SRP) initiator")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Cc: <stable@vger.kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/core: Simplify sa_path_set_[sd]lid() calls

Instead of making every caller convert the second argument of
sa_path_set_slid() and sa_path_set_dlid() to big endian format,
make these two functions accept LIDs in CPU endian format.
This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Cc: Don Hiatt <don.hiatt@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA: Remove useless MODULE_VERSION

All modules in drivers/infiniband defined and used MODULE_VERSION, which
was pointless because the kernel version describes their state more accurate
then those arbitrary numbers.

Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Sagi Grimbrg <sagi@grimberg.me>
Reviewed-by: Sagi Grimberg <sagi@grimbeg.me>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Acked-by: Ram Amrani <Ram.Amrani@cavium.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Adit Ranadive <aditr@vmware.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/SA: Fix kernel panic in CMA request handler flow

Commit 9fdca4da4d8c (IB/SA: Split struct sa_path_rec based on IB and
ROCE specific fields) moved the service_id to be specific attribute
for IB and OPA SA Path Record, and thus wasn't assigned for RoCE.

This caused to the following kernel panic in the CMA request handler flow:

[ 27.074594] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 27.074731] IP: __radix_tree_lookup+0x1d/0xe0
...
[ 27.075356] Workqueue: ib_cm cm_work_handler [ib_cm]
[ 27.075401] task: ffff88022e3b8000 task.stack: ffffc90001298000
[ 27.075449] RIP: 0010:__radix_tree_lookup+0x1d/0xe0
...
[ 27.075979] Call Trace:
[ 27.076015] radix_tree_lookup+0xd/0x10
[ 27.076055] cma_ps_find+0x59/0x70 [rdma_cm]
[ 27.076097] cma_id_from_event+0xd2/0x470 [rdma_cm]
[ 27.076144] ? ib_init_ah_from_path+0x39a/0x590 [ib_core]
[ 27.076193] cma_req_handler+0x25/0x480 [rdma_cm]
[ 27.076237] cm_process_work+0x25/0x120 [ib_cm]
[ 27.076280] ? cm_get_bth_pkey.isra.62+0x3c/0xa0 [ib_cm]
[ 27.076350] cm_req_handler+0xb03/0xd40 [ib_cm]
[ 27.076430] ? sched_clock_cpu+0x11/0xb0
[ 27.076478] cm_work_handler+0x194/0x1588 [ib_cm]
[ 27.076525] process_one_work+0x160/0x410
[ 27.076565] worker_thread+0x137/0x4a0
[ 27.076614] kthread+0x112/0x150
[ 27.076684] ? max_active_store+0x60/0x60
[ 27.077642] ? kthread_park+0x90/0x90
[ 27.078530] ret_from_fork+0x2c/0x40

This patch moves it back to the common SA Path Record structure
and removes the redundant setter and getter.

Tested on Connect-IB and Connect-X4 in Infiniband and RoCE respectively.

Fixes: 9fdca4da4d8c (IB/SA: Split struct sa_path_rec based on IB ands
ROCE specific fields)
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/srp: Fix NULL deref at srp_destroy_qp()

If srp_init_qp() fails at srp_create_ch_ib() then ch->send_cq
may be NULL.
Calling directly to ib_destroy_qp() is sufficient because
no work requests were posted on the created qp.

Fixes: 9294000d6d89 ("IB/srp: Drain the send queue before destroying a QP")
Cc: <stable@vger.kernel.org>
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Bart van Assche <bart.vanassche@sandisk.com>--
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/SA: Add support to query OPA path records

When the bit 26 of capmask2 field in OPA classport info
query is set, SA will query for OPA path records instead
of querying for IB path records. Note that OPA
path records can only be queried by kernel ULPs.
Userspace clients continue to query IB path records.

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

IB/SA: Add OPA path record type

Add opa_sa_path_rec to sa_path_rec data structure.
The 'type' field in sa_path_rec identifies the
type of the path record.

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

IB/SA: Split struct sa_path_rec based on IB and ROCE specific fields

sa_path_rec now contains a union of sa_path_rec_ib and sa_path_rec_roce
based on the type of the path record. Note that fields applicable to
path record type ROCE v1 and ROCE v2 fall under sa_path_rec_roce.
Accessor functions are added to these fields so the caller doesn't have
to know the type.

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

IB/SA: Rename ib_sa_path_rec to sa_path_rec

Rename ib_sa_path_rec to a more generic sa_path_rec.
This is part of extending ib_sa to also support OPA
path records in addition to the IB defined path records.

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

IB/srp: Drain the send queue before destroying a QP

A quote from the IB spec:

However, if the Consumer does not wait for the Affiliated Asynchronous
Last WQE Reached Event, then WQE and Data Segment leakage may occur.
Therefore, it is good programming practice to tear down a QP that is
associated with an SRQ by using the following process:
* Put the QP in the Error State;
* wait for the Affiliated Asynchronous Last WQE Reached Event;
* either:
* drain the CQ by invoking the Poll CQ verb and either wait for CQ
to be empty or the number of Poll CQ operations has exceeded CQ
capacity size; or
* post another WR that completes on the same CQ and wait for this WR to return as a WC;
* and then invoke a Destroy QP or Reset QP.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Israel Rukshin <israelr@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Improve an error path

Avoid that the following message is printed if login fails:

scsi host0: ib_srp: Sending CM DREQ failed

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Israel Rukshin <israelr@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Make a diagnostic message more informative

Report the destination port GID if connecting fails.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Israel Rukshin <israelr@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Document locking conventions

Use lockdep_assert_held() statements to verify at run-time
whether the proper locks are held.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Israel Rukshin <israelr@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix race conditions related to task management

Avoid that srp_process_rsp() overwrites the status information
in ch if the SRP target response timed out and processing of
another task management function has already started. Avoid that
issuing multiple task management functions concurrently triggers
list corruption. This patch prevents that the following stack
trace appears in the system log:

WARNING: CPU: 8 PID: 9269 at lib/list_debug.c:52 __list_del_entry_valid+0xbc/0xc0
list_del corruption. prev->next should be ffffc90004bb7b00, but was ffff8804052ecc68
CPU: 8 PID: 9269 Comm: sg_reset Tainted: G W 4.10.0-rc7-dbg+ #3
Call Trace:
dump_stack+0x68/0x93
__warn+0xc6/0xe0
warn_slowpath_fmt+0x4a/0x50
__list_del_entry_valid+0xbc/0xc0
wait_for_completion_timeout+0x12e/0x170
srp_send_tsk_mgmt+0x1ef/0x2d0 [ib_srp]
srp_reset_device+0x5b/0x110 [ib_srp]
scsi_ioctl_reset+0x1c7/0x290
scsi_ioctl+0x12a/0x420
sd_ioctl+0x9d/0x100
blkdev_ioctl+0x51e/0x9f0
block_ioctl+0x38/0x40
do_vfs_ioctl+0x8f/0x700
SyS_ioctl+0x3c/0x70
entry_SYSCALL_64_fastpath+0x18/0xad

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Israel Rukshin <israelr@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Steve Feeley <Steve.Feeley@sandisk.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Avoid that duplicate responses trigger a kernel bug

After srp_process_rsp() returns there is a short time during which
the scsi_host_find_tag() call will return a pointer to the SCSI
command that is being completed. If during that time a duplicate
response is received, avoid that the following call stack appears:

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: srp_recv_done+0x450/0x6b0 [ib_srp]
Oops: 0000 [#1] SMP
CPU: 10 PID: 0 Comm: swapper/10 Not tainted 4.10.0-rc7-dbg+ #1
Call Trace:
<IRQ>
__ib_process_cq+0x4b/0xd0 [ib_core]
ib_poll_handler+0x1d/0x70 [ib_core]
irq_poll_softirq+0xba/0x120
__do_softirq+0xba/0x4c0
irq_exit+0xbe/0xd0
smp_apic_timer_interrupt+0x38/0x50
apic_timer_interrupt+0x90/0xa0
</IRQ>
RIP: srp_recv_done+0x450/0x6b0 [ib_srp] RSP: ffff88046f483e20

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Israel Rukshin <israelr@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Steve Feeley <Steve.Feeley@sandisk.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/SRP: Avoid using IB_MR_TYPE_SG_GAPS

Tests have shown that the following error message is reported when
using SG-GAPS registration with an mlx5 adapter:

scsi host1: ib_srp: failed RECV status WR flushed (5) for CQE ffff880bd4270eb0
00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000
00000000 0f007806 2500002a ad9fafd1
scsi host1: ib_srp: reconnect succeeded
mlx5_0:dump_cqe:262:(pid 7369): dump error cqe
00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000
00000000 0f007806 25000032 00105dd0
scsi host1: ib_srp: failed FAST REG status memory management operation error (6) for CQE ffff880b92860138

Hence avoid using SG-GAPS memory registrations. Additionally,
always configure the blk_queue_virt_boundary() to avoid to trigger
a mapping failure when using adapters that support SG-GAPS (e.g.
mlx5).

Fixes: commit ad8e66b4a801 ("IB/srp: fix mr allocation when the device supports sg gaps")
Fixes: commit 509c5f33f4f6 ("IB/srp: Prevent mapping failures")
Reported-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Israel Rukshin <israelr@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mark Bloch <markb@mellanox.com>
Cc: Yuval Shaia <yuval.shaia@oracle.com>
Cc: <stable@vger.kernel.org> # 4.7+
Signed-off-by: Doug Ledford <dledford@redhat.com>

scsi: remove eh_timed_out methods in the transport template

Instead define the timeout behavior purely based on the host_template
eh_timed_out method and wire up the existing transport implementations
in the host templates. This also clears up the confusion that the
transport template method overrides the host template one, so some
drivers have to re-override the transport template one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

IB/srp: Switch from dma_device to dev.parent

Prepare for removal of ib_device.dma_device.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: fix invalid indirect_sg_entries parameter value

After setting indirect_sg_entries module_param to huge value (e.g 500,000),
srp_alloc_req_data() fails to allocate indirect descriptors for the request
ring (kmalloc fails). This commit enforces the maximum value of
indirect_sg_entries to be SG_MAX_SEGMENTS as signified in module param
description.

Fixes: 65e8617fba17 (scsi: rename SCSI_MAX_{SG, SG_CHAIN}_SEGMENTS)
Fixes: c07d424d6118 (IB/srp: add support for indirect tables that don't fit in SRP_CMD)
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>--
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: fix mr allocation when the device supports sg gaps

If the device support arbitrary sg list mapping (device cap
IB_DEVICE_SG_GAPS_REG set) we allocate the memory regions with
IB_MR_TYPE_SG_GAPS.

Fixes: 509c5f33f4f6 ("IB/srp: Prevent mapping failures")
Cc: <stable@vger.kernel.org> # 4.7+
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Make writing the add_target sysfs attr interruptible

Avoid that shutdown of srp_daemon is delayed if add_target_mutex is
held by another process.

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

IB/srp: Make mapping failures easier to debug

Make it easier to figure out what is going on if memory mapping
fails because more memory regions than mr_per_cmd are needed.

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

IB/srp: Make login failures easier to debug

If login fails because memory region allocation failed it can be
hard to figure out what happened. Make it easier to figure out
why login failed by logging a message if ib_alloc_mr() fails.

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

IB/srp: Introduce a local variable in srp_add_one()

This patch makes the srp_add_one() code more compact and does not
change any functionality.

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

IB/srp: Fix CONFIG_DYNAMIC_DEBUG=n build

Avoid that the kernel build fails as follows if dynamic debug support
is disabled:

drivers/infiniband/ulp/srp/ib_srp.c:2272:3: error: implicit declaration of function 'DEFINE_DYNAMIC_DEBUG_METADATA'
drivers/infiniband/ulp/srp/ib_srp.c:2272:33: error: 'ddm' undeclared (first use in this function)
drivers/infiniband/ulp/srp/ib_srp.c:2275:39: error: '_DPRINTK_FLAGS_PRINT' undeclared (first use in this function)

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

IB/srp: Fix infinite loop when FMR sg[0].offset != 0

Avoid that mapping an sg-list in which the first element has a
non-zero offset triggers an infinite loop when using FMR. This
patch makes the FMR mapping code similar to that of ib_sg_to_pages().

Note: older Mellanox HCAs do not support non-zero offsets for FMR.
See also commit 8c4037b501ac ("IB/srp: always avoid non-zero offsets
into an FMR").

Reported-by: Alex Estrin <alex.estrin@intel.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Remove an unused argument

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

IB/srp: use IB_PD_UNSAFE_GLOBAL_RKEY

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/core: add support to create a unsafe global rkey to ib_create_pd

Instead of exposing ib_get_dma_mr to ULPs and letting them use it more or
less unchecked, this moves the capability of creating a global rkey into
the RDMA core, where it can be easily audited. It also prints a warning
everytime this feature is used as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix srp_map_sg_dma()

Because patch "IB/srp: Move common code into the caller" was applied
partially srp_map_sg_dma() doesn't work properly. Fix this by
applying the remainder of that patch. See also
http://thread.gmane.org/gmane.linux.drivers.rdma/35803/focus=35811.

Fixes: 3849e44d1c4b ("IB/srp: Move common code into the caller")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Sagi Grimberg <sai@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Always initialize use_fast_reg and use_fmr

Avoid that mapping fails due to use_fast_reg != 0 or use_fmr != 0
if both member variables should be zero (if never_register == 1 or
if neither FMR nor FR is supported). Remove an initialization that
became superfluous due to changing a kmalloc() into a kzalloc()
call.

Fixes: 509c5f33f4f6 ("IB/srp: Prevent mapping failures")
Cc: Sagi Grimberg <sai@grimberg.m>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix a debug kernel crash

Avoid that the following BUG() is triggered against a debug
kernel:

kernel BUG at include/linux/scatterlist.h:92!
RIP: 0010:[<ffffffffa0467199>] [<ffffffffa0467199>] srp_map_idb+0x199/0x1a0 [ib_srp]
Call Trace:
[<ffffffffa04685fa>] srp_map_data+0x84a/0x890 [ib_srp]
[<ffffffffa0469674>] srp_queuecommand+0x1e4/0x610 [ib_srp]
[<ffffffff813f5a5e>] scsi_dispatch_cmd+0x9e/0x180
[<ffffffff813f8b07>] scsi_request_fn+0x477/0x610
[<ffffffff81298ffe>] __blk_run_queue+0x2e/0x40
[<ffffffff81299070>] blk_delay_work+0x20/0x30
[<ffffffff81071f07>] process_one_work+0x197/0x480
[<ffffffff81072239>] worker_thread+0x49/0x490
[<ffffffff810787ea>] kthread+0xea/0x100
[<ffffffff8159b632>] ret_from_fork+0x22/0x40

Fixes: f7f7aab1a5c0 ("IB/srp: Convert to new registration API")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org> # v4.4+
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Do not register memory if never_register has been set

This makes it easier to test the code path that does not use
memory registration (srp_map_sg_dma()).

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Prevent mapping failures

If both max_sectors and the queue_depth are high enough it can
happen that the MR pool is depleted temporarily. This causes
the SRP initiator to report mapping failures. Although the SRP
initiator recovers from such mapping failures, prevent that
this can happen by allocating more memory regions.

Additionally, only enable memory registration if at least two
pages can be registered per memory region.

Reported-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: 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/srp: Swap two code blocks in srp_add_one()

This patch does not change any functionality but makes the next
patch in this series easier to read.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: 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/core: Enhance ib_map_mr_sg()

The SRP initiator allows to set max_sectors to a value that exceeds
the largest amount of data that can be mapped at once with an mlx4
HCA using fast registration and a page size of 4 KB. Hence modify
ib_map_mr_sg() such that it can map partial sg-elements. If an
sg-element has been mapped partially, let the caller know
which fraction has been mapped by adjusting *sg_offset.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: 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/srp: Fix srp_create_target() error handling

Avoid that the following kernel oops occurs if memory pool
allocation fails:

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffa048d0a0>] ib_drain_rq+0x0/0x20 [ib_core]
Call Trace:
[<ffffffffa04af386>] srp_create_target+0xca6/0x13a9 [ib_srp]
[<ffffffff813cc863>] dev_attr_store+0x13/0x20
[<ffffffff81214b50>] sysfs_kf_write+0x40/0x50
[<ffffffff81213f1c>] kernfs_fop_write+0x13c/0x180
[<ffffffff81197683>] __vfs_write+0x23/0xf0
[<ffffffff81198744>] vfs_write+0xa4/0x1a0
[<ffffffff81199a44>] SyS_write+0x44/0xa0
[<ffffffff8159e3e9>] entry_SYSCALL_64_fastpath+0x1c/0xac

Fixes: 1dc7b1f10dcb ("IB/srp: use the new CQ API")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix a memory descriptor leak in an error path

If an error occurs after srp_fr_pool_get() succeeded and before the
descriptor is stored in srp_map_state (*state->fr.next++ = desc)
then srp_unmap_data() won't free the newly allocated memory
descriptor. Hence free the descriptor explicitly.

Fixes: f7f7aab1a5c0 ("IB/srp: Convert to new registration API")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Cc: Sagi Grimberg <sai@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Print "ib_srp: " prefix once

pr_debug() already prints prefix PFX. Avoid that PFX is printed
twice if the debug statement in srp_add_target() is enabled.

Fixes: 34aa654ecb8e ("IB/srp: Avoid that I/O hangs due to a cable pull during LUN scanning")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Tested-by: 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/core: Add passing an offset into the SG to ib_map_mr_sg

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Move common code into the caller

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Sagi Grimberg <sai@grimberg.m>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Move code out of a loop

Since all srp_map_finish_fr() callers pass a non-zero value as
the fourth argument (sg_nents), the sg_nents == 0 check in that
function can be removed. Add a count == 0 check in the caller
of that function.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Avoid that mapping failure triggers an infinite loop

The srp_queuecommand() function translates ENOMEM into QUEUE_FULL
which causes the SCSI mid-layer to retry the command. All other
error codes are translated into DID_ERROR which causes the SCSI
command to fail. Return E2BIG if mapping will always fail to
prevent that the SCSI mid-layer keeps resubmitting a command
forever.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Introduce target->mr_pool_size

This patch does not change any functionality.

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

IB/srp: Fix srp_map_data() error paths

Ensure that req->nmdesc is set correctly in srp_map_sg() if mapping
fails. Avoid that mapping failure causes a memory descriptor leak.
Report srp_map_sg() failure to the caller.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Document srp_map_data() return value

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

IB/srp: Fix a comment

The free request list was removed through patch "IB/srp: Use block layer tags".
Hence update a comment that refers to that free request list.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix a spelling error in a source code comment

Change one occurrence of "boundries" into "boundaries".

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

scsi: rename SCSI_MAX_{SG, SG_CHAIN}_SEGMENTS

Rename SCSI_MAX_SG_SEGMENTS to SG_CHUNK_SIZE, which means the amount
we fit into a single scatterlist chunk.

Rename SCSI_MAX_SG_CHAIN_SEGMENTS to SG_MAX_SEGMENTS.

Will move these 2 generic definitions to scatterlist.h later.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Bart Van Assche <bart.vanassche@sandisk.com> (for ib_srp changes)
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: disable automatic target scan

On larger installations it is useful to disable automatic LUN scanning,
and only add the required LUNs via udev rules. This can speed up bootup
dramatically.

This patch introduces a new scan module parameter value 'manual', which
works like 'none', but can be overridden by setting the 'rescan' value
from scsi_scan_target to 'SCSI_SCAN_MANUAL'. And it updates all
relevant callers to set the 'rescan' value to 'SCSI_SCAN_MANUAL' if
invoked via the 'scan' option in sysfs.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

IB/srp: Use ib_drain_rq()

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

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/srp: use the new CQ API

This also moves recv completion handling from hardirq context into
softirq context.

Signed-off-by: Christoph Hellwig <hch@lst.de>

IB: add a proper completion queue abstraction

This adds an abstraction that allows ULPs to simply pass a completion
object and completion callback with each submitted WR and let the RDMA
core handle the nitty gritty details of how to handle completion
interrupts and poll the CQ.

In detail there is a new ib_cqe structure which just contains the
completion callback, and which can be used to get at the containing
object using container_of. It is pointed to by the WR and WC as an
alternative to the wr_id field, similar to how many ULPs already use
the field to store a pointer using casts.

A driver using the new completion callbacks allocates it's CQs using
the new ib_create_cq API, which in addition to the number of CQEs and
the completion vectors also takes a mode on how we poll for CQEs.
Three modes are available: direct for drivers that never take CQ
interrupts and just poll for them, softirq to poll from softirq context
using the to be renamed blk-iopoll infrastructure which takes care of
rearming and budgeting, or a workqueue for consumer who want to be
called from user context.

Thanks a lot to Sagi Grimberg who helped reviewing the API, wrote
the current version of the workqueue code because my two previous
attempts sucked too much and converted the iSER initiator to the new
API.

Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Fix srp_map_sg_fr()

After dma_map_sg() has been called the return value of that function
must be used as the number of elements in the scatterlist instead of
scsi_sg_count().

Fixes: commit f7f7aab1a5c0 ("IB/srp: Convert to new registration API")
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: stable <stable@vger.kernel.org> # v4.4+
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix indirect data buffer rkey endianness

Detected by sparse.

Fixes: commit 330179f2fa93 ("IB/srp: Register the indirect data buffer descriptor")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: stable <stable@vger.kernel.org> # v4.3+
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Initialize dma_length in srp_map_idb

Without this sg_dma_len will return 0 on architectures tha have
the dma_length field.

Fixes: commit f7f7aab1a5c0 ("IB/srp: Convert to new registration API")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix possible send queue overflow

When using work request based memory registration (fast_reg)
we must reserve SQ entries for registration and invalidation
in addition to send operations. Each IO consumes 3 SQ entries
(registration, send, invalidation) so we need to allocate 3x
larger send-queue instead of 2x.

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

IB/srp: Fix a memory leak

If srp_connect_ch() returns a positive value then that is considered
by its caller as a connection failure but this does not result in a
scsi_host_put() call and additionally causes the srp_create_target()
function to return a positive value while it should return a negative
value. Avoid all this confusion and additionally fix a memory leak by
ensuring that srp_connect_ch() always returns a value that is <= 0.
This patch avoids that a rejected login triggers the following memory
leak:

unreferenced object 0xffff88021b24a220 (size 8):
comm "srp_daemon", pid 56421, jiffies 4295006762 (age 4240.750s)
hex dump (first 8 bytes):
68 6f 73 74 35 38 00 a5 host58..
backtrace:
[<ffffffff8151014a>] kmemleak_alloc+0x7a/0xc0
[<ffffffff81165c1e>] __kmalloc_track_caller+0xfe/0x160
[<ffffffff81260d2b>] kvasprintf+0x5b/0x90
[<ffffffff81260e2d>] kvasprintf_const+0x8d/0xb0
[<ffffffff81254b0c>] kobject_set_name_vargs+0x3c/0xa0
[<ffffffff81337e3c>] dev_set_name+0x3c/0x40
[<ffffffff81355757>] scsi_host_alloc+0x327/0x4b0
[<ffffffffa03edc8e>] srp_create_target+0x4e/0x8a0 [ib_srp]
[<ffffffff8133778b>] dev_attr_store+0x1b/0x20
[<ffffffff811f27fa>] sysfs_kf_write+0x4a/0x60
[<ffffffff811f1e8e>] kernfs_fop_write+0x14e/0x180
[<ffffffff81176eef>] __vfs_write+0x2f/0xf0
[<ffffffff811771e4>] vfs_write+0xa4/0x100
[<ffffffff81177c64>] SyS_write+0x54/0xc0
[<ffffffff8151b257>] entry_SYSCALL_64_fastpath+0x12/0x6f

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: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

scsi: use host wide tags by default

This patch changes the !blk-mq path to the same defaults as the blk-mq
I/O path by always enabling block tagging, and always using host wide
tags. We've had blk-mq available for a few releases so bugs with
this mode should have been ironed out, and this ensures we get better
coverage of over tagging setup over different configs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

IB/srp: Dont allocate a page vector when using fast_reg

The new fast registration API does not reuqire a page vector
so we can't avoid allocating it.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Remove srp_finish_mapping

No callers left, remove it.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Convert to new registration API

Instead of constructing a page list, call ib_map_mr_sg
and post a new ib_reg_wr. srp_map_finish_fr now returns
the number of sg elements registered.

Remove srp_finish_mapping since no one is calling it.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Split srp_map_sg

This is a preparation patch for the new registration API
conversion. It splits srp_map_sg per registration strategy
(srp_map_sg[fmr|fr|dma]. On its own it adds some code duplication,
but it makes the API switch easier to comprehend.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/core: Add netdev and gid attributes paramteres to cache

Adding an ability to query the IB cache by a netdev and get the
attributes of a GID. These parameters are necessary in order to
successfully resolve the required GID (when the netdevice is known)
and get the Ethernet L2 attributes from a GID.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-By: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB: split struct ib_send_wr

This patch split up struct ib_send_wr so that all non-trivial verbs
use their own structure which embedds struct ib_send_wr. This dramaticly
shrinks the size of a WR for most common operations:

sizeof(struct ib_send_wr) (old): 96

sizeof(struct ib_send_wr): 48
sizeof(struct ib_rdma_wr): 64
sizeof(struct ib_atomic_wr): 96
sizeof(struct ib_ud_wr): 88
sizeof(struct ib_fast_reg_wr): 88
sizeof(struct ib_bind_mw_wr): 96
sizeof(struct ib_sig_handover_wr): 80

And with Sagi's pending MR rework the fast registration WR will also be
down to a reasonable size:

sizeof(struct ib_fastreg_wr): 64

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> [srp, srpt]
Reviewed-by: Chuck Lever <chuck.lever@oracle.com> [sunrpc]
Tested-by: Haggai Eran <haggaie@mellanox.com>
Tested-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>

IB/srp: Fix possible protection fault

srp_destroy_qp is designed to indicate we are safe to continue with
freeing the channel resources by modifying the qp error state,
posting a dummy wr on the queue-pair and waiting for it to flush.
This also holds for the channel registration pool as we are unmapping
the memory region when handling a scsi response. Destroying the
channel registration pool before we make sure we processed all the
inflight IO might introduce a use-after-free of the registration pool.

This use-after-free is demonstrated in the stack trace below where
srp is trying to unmap a used FMR after the fmr_pool was already destroyed.

general protection fault: 0000 [#1] SMP
RIP: 0010:[<ffffffff8151121b>] [<ffffffff8151121b>] _raw_spin_lock_irqsave+0x1b/0x50
Call Trace:
[<ffffffffa055d88a>] ib_fmr_pool_unmap+0x1a/0xb0 [ib_core]
[<ffffffffa06c00ed>] srp_unmap_data.isra.28+0x17d/0x250 [ib_srp]
[<ffffffffa06c01eb>] srp_free_req+0x2b/0x60 [ib_srp]
[<ffffffffa06c0c94>] srp_recv_completion+0x174/0x580 [ib_srp]
[<ffffffffa04580fe>] mlx4_eq_int+0x4de/0xe50 [mlx4_core]
[<ffffffffa0458b00>] mlx4_msi_x_interrupt+0x10/0x20 [mlx4_core]
[<ffffffff810abc45>] handle_irq_event_percpu+0x35/0x1b0
[<ffffffff810abdf2>] handle_irq_event+0x32/0x50
[<ffffffff810ae5cf>] handle_edge_irq+0x6f/0x120
[<ffffffff8100455a>] handle_irq+0x1a/0x30
[<ffffffff8151b475>] do_IRQ+0x45/0xb0
[<ffffffff8151162d>] common_interrupt+0x6d/0x6d
[<ffffffff813e4d2f>] cpuidle_enter_state+0x4f/0xc0
[<ffffffff813e4e6c>] cpuidle_idle_call+0xcc/0x210
[<ffffffff8100b9ea>] arch_cpu_idle+0xa/0x30
[<ffffffff810ab1e1>] cpu_startup_entry+0xe1/0x270
[<ffffffff81030b3a>] start_secondary+0x21a/0x2c0

Reported-by: Eliott Kespi <eliottk@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Create an insecure all physical rkey only if needed

The SRP initiator only needs this if the insecure register_always=N
performance optimization is enabled, or if FRWR/FMR is not supported
in the driver.

Do not create an all physical MR unless it is needed to support
either of those modes. Default register_always to true so the out of
the box configuration does not create an insecure all physical MR.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
[bvanassche: reworked and rebased this patch]
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Register the indirect data buffer descriptor

Instead of always using the global rkey for the indirect data
buffer descriptor, register that descriptor with the HCA if
the kernel module parameter register_always has been set to Y.

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

IB/srp: Introduce srp_device.use_fmr

Introduce the variable srp_device.use_fmr. Leave out the dev->has_fr /
dev->has_fmr and ch->fr_pool / ch->fmr_pool checks since these are
redundant. This patch does not change any functionality but makes the
source code easier to read.

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

IB/srp: Remove use_mr argument from srp_map_sg_entry()

Move the srp_map_desc() call from inside srp_map_sg_entry() to
srp_map_sg() such that the use_mr argument can be removed from
srp_map_sg_entry().

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

IB/srp: Remove the memory registration backtracking code

Mapping a discontiguous sg-list requires multiple memory regions
and hence can exhaust the memory region pool. The SRP initiator
already handles this by temporarily reducing the queue depth. This
means that it is safe to remove the memory registration backtracking
code. This patch has been tested with direct I/O sizes up to 256 MB.

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

IB/srp: Add memory descriptor array pointer range checking

Although most paths through which a request is submitted check
block layer parameters like the max_segments limit, these are
not checked when an SG_IO or direct I/O request is submitted.
Hence add a range check for the memory descriptor array pointer.

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

IB/srp: Use multiple registrations for large memory regions

Instead of using the global rkey for large memory regions, use
multiple registrations. See also the while (dma_len) loop further
down in srp_map_sg_entry().

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

IB/srp: Re-enable FMR for non-page aligned buffers

During a discussion in 2011 nobody recalled why FMR was not used for
non-page aligned buffers (see also
http://thread.gmane.org/gmane.linux.drivers.rdma/7149). Re-enable FMR
for such buffers. For the reason why the srp_map_fmr() function needs
to be modified, see also patch "IB/srp: rework mapping engine to use
multiple FMR entries" (commit ID 8f26c9ff9cd0; January 2011).

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

IB/srp: 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 will
have to be fixed separately.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Stop the scsi_eh_<n> and scsi_tmf_<n> threads if login fails

scsi_host_alloc() not only allocates memory for a SCSI host but also
creates the scsi_eh_<n> kernel thread and the scsi_tmf_<n> workqueue.
Stop these threads if login fails by calling scsi_host_put().

Reported-by: Konstantin Krotov <kkv@clodo.ru>
Fixes: fb49c8bbaae7 ("Remove an extraneous scsi_host_put() from an error path")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.19
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Bump driver version and release date

Since version 1.0 e.g. scsi-mq has been added. Since this is
a significant change, bump the driver version and release date.

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

IB/srp: Handle partial connection success correctly

Avoid that the following kernel warning is reported if the SRP
target system accepts fewer channels per connection than what
was requested by the initiator system:

WARNING: at drivers/infiniband/ulp/srp/ib_srp.c:617 srp_destroy_qp+0xb1/0x120 [ib_srp]()
Call Trace:
[<ffffffff8105d67f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff8105d6da>] warn_slowpath_null+0x1a/0x20
[<ffffffffa05419e1>] srp_destroy_qp+0xb1/0x120 [ib_srp]
[<ffffffffa05445fb>] srp_create_ch_ib+0x19b/0x420 [ib_srp]
[<ffffffffa0545257>] srp_create_target+0x7d7/0xa94 [ib_srp]
[<ffffffff8138dac0>] dev_attr_store+0x20/0x30
[<ffffffff812079ef>] sysfs_write_file+0xef/0x170
[<ffffffff81191fc4>] vfs_write+0xb4/0x130
[<ffffffff8119276f>] sys_write+0x5f/0xa0
[<ffffffff815a0a59>] system_call_fastpath+0x16/0x1b

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Constify a function argument

This patch does not change any functionality.

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

IB/srp: Convert to ib_alloc_mr

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

IB/core: lock client data with lists_rwsem

An ib_client callback that is called with the lists_rwsem locked only for
read is protected from changes to the IB client lists, but not from
ib_unregister_device() freeing its client data. This is because
ib_unregister_device() will remove the device from the device list with
lists_rwsem locked for write, but perform the rest of the cleanup,
including the call to remove() without that lock.

Mark client data that is undergoing de-registration with a new going_down
flag in the client data context. Lock the client data list with lists_rwsem
for write in addition to using the spinlock, so that functions calling the
callback would be able to lock only lists_rwsem for read and let callbacks
sleep.

Since ib_unregister_client() now marks the client data context, no need for
remove() to search the context again, so pass the client data directly to
remove() callbacks.

Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Avoid using uninitialized variable

We might return res which is not initialized. Also
reduce code duplication by exporting srp_parse_tmo so
srp_tmo_set can reuse it.

Detected by Coverity.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jenny Falkovich <jennyf@mellanox.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB: Add rdma_cap_ib_switch helper and use where appropriate

Persuant to Liran's comments on node_type on linux-rdma
mailing list:

In an effort to reform the RDMA core and ULPs to minimize use of
node_type in struct ib_device, an additional bit is added to
struct ib_device for is_switch (IB switch). This is needed
to be initialized by any IB switch device driver. This is a
NEW requirement on such device drivers which are all
"out of tree".

In addition, an ib_switch helper was added to ib_verbs.h
based on the is_switch device bit rather than node_type
(although those should be consistent).

The RDMA core (MAD, SMI, agent, sa_query, multicast, sysfs)
as well as (IPoIB and SRP) ULPs are updated where
appropriate to use this new helper. In some cases,
the helper is now used under the covers of using
rdma_[start end]_port rather than the open coding
previously used.

Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Reviewed-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/core: Change ib_create_cq to use struct ib_cq_init_attr

Currently, ib_create_cq uses cqe and comp_vecotr instead
of the extendible ib_cq_init_attr struct.

Earlier patches already changed the vendors to work with
ib_cq_init_attr. This patch changes the consumers too.

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

kernel/params: constify struct kernel_param_ops uses

Most code already uses consts for the struct kernel_param_ops,
sweep the kernel for the last offending stragglers. Other than
include/linux/moduleparam.h and kernel/params.c all other changes
were generated with the following Coccinelle SmPL patch. Merge
conflicts between trees can be handled with Coccinelle.

In the future git could get Coccinelle merge support to deal with
patch --> fail --> grammar --> Coccinelle --> new patch conflicts
automatically for us on patches where the grammar is available and
the patch is of high confidence. Consider this a feature request.

Test compiled on x86_64 against:

* allnoconfig
* allmodconfig
* allyesconfig

@ const_found @
identifier ops;
@@

const struct kernel_param_ops ops = {
};

@ const_not_found depends on !const_found @
identifier ops;
@@

-struct kernel_param_ops ops = {
+const struct kernel_param_ops ops = {
};

Generated-by: Coccinelle SmPL
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Junio C Hamano <gitster@pobox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: cocci@systeme.lip6.fr
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

IB/srp: Align to generic logging helpers

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

IB/srp: Add 64-bit LUN support

The SCSI standard defines 64-bit values for LUNs. Large arrays
employing large or hierarchical LUN numbers become more and more
common. So update the SRP initiator to use 64-bit LUN numbers.
See also Hannes Reinecke, commit 9cb78c16f5da ("scsi: use 64-bit LUNs"),
June 2014.

The largest LUN number that has been tested is 0xd2003fff00000000.

Checked the following structure sizes with gdb:
* sizeof(struct srp_cmd) = 48
* sizeof(struct srp_tsk_mgmt) = 48
* sizeof(struct srp_aer_req) = 36

The ibmvscsi changes have been compile tested only (on a PPC system).

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Yann Droneaud <ydroneaud@opteya.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Remove !ch->target tests from the reconnect code

Remove the !ch->target tests from the reconnect code. These
tests are not needed: upon entry of srp_rport_reconnect()
it is guaranteed that all ch->target pointers are non-NULL.
None of the functions srp_new_cm_id(), srp_finish_req(),
srp_create_ch_ib() nor srp_connect_ch() modifies this pointer.
srp_free_ch_ib() is never called concurrently with
srp_rport_reconnect().

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Remove a superfluous check from srp_free_req_data()

The function srp_free_req_data() does not use ch->target.
Hence remove the ch->target != NULL check.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Rearrange module description

Move the module version and release date into separate fields.
This makes the modinfo output easier to read.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Remove superfluous casts

A long time ago the data type int64_t was declared as long long
on x86 systems and as long on PPC systems. Today that data type
is declared as long long on all Linux architectures. This means
that the casts from uint64_t into unsigned long long are
superfluous. Remove these superfluous casts.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix reconnection failure handling

Although it is possible to let SRP I/O continue if a reconnect
results in a reduction of the number of channels, the current
code does not handle this scenario correctly. Instead of making
the reconnect code more complex, consider this as a reconnection
failure.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.19
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix connection state tracking

Reception of a DREQ message only causes the state of a single
channel to change. Hence move the 'connected' member variable
from the target to the channel data structure. This patch
avoids that following false positive warning can be reported
by srp_destroy_qp():

WARNING: at drivers/infiniband/ulp/srp/ib_srp.c:617 srp_destroy_qp+0xa6/0x120 [ib_srp]()
Call Trace:
[<ffffffff8106e10f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff8106e16a>] warn_slowpath_null+0x1a/0x20
[<ffffffffa0440226>] srp_destroy_qp+0xa6/0x120 [ib_srp]
[<ffffffffa0440322>] srp_free_ch_ib+0x82/0x1e0 [ib_srp]
[<ffffffffa044408b>] srp_create_target+0x7ab/0x998 [ib_srp]
[<ffffffff81346f60>] dev_attr_store+0x20/0x30
[<ffffffff811dd90f>] sysfs_write_file+0xef/0x170
[<ffffffff8116d248>] vfs_write+0xc8/0x190
[<ffffffff8116d411>] sys_write+0x51/0x90

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.19
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Fix a connection setup race

Avoid that receiving a DREQ while RDMA channels are being
established causes target->qp_in_error to be reset.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.19
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Remove an extraneous scsi_host_put() from an error path

Fix a scsi_get_host() / scsi_host_put() imbalance in the error
path of srp_create_target(). See also patch "IB/srp: Avoid that
I/O hangs due to a cable pull during LUN scanning" (commit ID
34aa654ecb8e).

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.19
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Use P_Key cache for P_Key lookups

This change slightly reduces the time needed to log in.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: David Dillow <dave@thedillows.org>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/srp: Allow newline separator for connection string

In case the last argument of the connection string is processed as a
string (destination GID for example).

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Acked-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

scsi: remove ->change_queue_type method

Since we got rid of ordered tag support in 2010 the prime use case of
switching on and off ordered tags has been obsolete. The other function
of enabling/disabling tagging entirely has only been correctly implemented
by the 53c700 driver and isn't generally useful.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: drop reason argument from ->change_queue_depth

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: don't allow setting of queue_depth bigger than can_queue

We won't ever queue more commands than the host allows. Instead of
letting drivers either reject or ignore this case handle it in
common code. Note that various driver use internal constant or
variables that are assigned to both shost->can_queue and checked
in ->change_queue_depth - I did remove those checks as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: avoid ->change_queue_depth indirection for queue full tracking

All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Venkatesh Srinivas <venkateshs@google.com>

IB/srp: Fix a race condition triggered by destroying a queue pair

At least LID reassignment can trigger a race condition in the SRP
initiator driver, namely the receive completion handler trying to
post a request on a QP during or after QP destruction and before
the CQ's have been destroyed. Avoid this race by modifying a QP
into the error state and by waiting until all receive completions
have been processed before destroying a QP.

Reported-by: Max Gurtuvoy <maxg@mellanox.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Add multichannel support

Improve performance by using multiple RDMA/RC channels per SCSI
host for communication with an SRP target. About the
implementation:
- Introduce a loop over all channels in the code that uses
target->ch.
- Set the SRP_MULTICHAN_MULTI flag during login for the creation
of the second and subsequent channels.
- RDMA completion vectors are chosen such that RDMA completion
interrupts are handled by the CPU socket that submitted the I/O
request. As one can see in this patch it has been assumed if a
system contains n CPU sockets and m RDMA completion vectors
have been assigned to an RDMA HCA that IRQ affinity has been
configured such that completion vectors [i*m/n..(i+1)*m/n) are
bound to CPU socket i with 0 <= i < n.
- Modify srp_free_ch_ib() and srp_free_req_data() such that it
becomes safe to invoke these functions after the corresponding
allocation function failed.
- Add a ch_count sysfs attribute per target port.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Use block layer tags

Since the block layer already contains functionality to assign
a tag to each request, use that functionality instead of
reimplementing that functionality in the SRP initiator driver.
This change makes the free_reqs list superfluous. Hence remove
that list.

[hch: updated to use .use_blk_tags instead scsi_activate_tcq]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Separate target and channel variables

Changes in this patch:
- Move channel variables into a new structure (struct srp_rdma_ch).
- Add an srp_target_port pointer, 'lock' and 'comp_vector' members
in struct srp_rdma_ch.
- Add code to initialize these three new member variables.
- Many boring "target->" into "ch->" changes.
- The cm_id and completion handler context pointers are now of type
srp_rdma_ch * instead of srp_target_port *.
- Three kzalloc(a * b, f) calls have been changed into kcalloc(a, b, f)
to avoid that this patch would trigger a checkpatch warning.
- Two casts from u64 into unsigned long long have been left out
because these are superfluous. Since considerable time u64 is
defined as unsigned long long for all architectures supported by
the Linux kernel.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Introduce two new srp_target_port member variables

Introduce the srp_target_port member variables 'sgid' and 'pkey'.
Change the type of 'orig_dgid' from __be16[8] into union ib_gid.
This patch does not change any functionality but makes the
"Separate target and channel variables" patch easier to verify.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Avoid that I/O hangs due to a cable pull during LUN scanning

If a cable is pulled during LUN scanning it can happen that the
SRP rport and the SCSI host have been created but no LUNs have been
added to the SCSI host. Since multipathd only sends SCSI commands
to a SCSI target if one or more SCSI devices are present and since
there is no keepalive mechanism for IB queue pairs this means that
after a LUN scan failed and after a reconnect has succeeded no
data will be sent over the QP and hence that a subsequent cable
pull will not be detected. Avoid this by not creating an rport or
SCSI host if a cable is pulled during a SCSI LUN scan.

Note: so far the above behavior has only been observed with the
kernel module parameter ch_count set to a value >= 2.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Remove stale connection retry mechanism

Attempting to connect three times may be insufficient after an
initiator system tries to relogin, especially if the relogin
attempt occurs before the SRP target service ID has been
registered. Since the srp_daemon retries a failed login attempt
anyway, remove the stale connection retry mechanism.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Move ib_destroy_cm_id() call into srp_free_ch_ib()

The patch that adds multichannel support into the SRP initiator
driver introduces an additional call to srp_free_ch_ib(). This
patch helps to keep that later patch simple.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth. For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway. The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: provide a generic change_queue_type method

Most drivers use exactly the same implementation, so provide it as a
library function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

IB/srp: Fix return value check in srp_init_module()

In case of error, the function create_workqueue() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should be
replaced with NULL test.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fix residual handling

From Documentation/scsi/scsi_mid_low_api.txt: "resid - an LLD should
set this signed integer to the requested transfer length (i.e.
'request_bufflen') less the number of bytes that are actually
transferred." This means that resid > 0 in case of an underrun and
also that resid < 0 in case of an overrun. Modify the SRP initiator
code such that it matches this requirement.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: David Dillow <dave@thedillows.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fix deadlock between host removal and multipathd

If scsi_remove_host() is invoked after a SCSI device has been blocked,
if the fast_io_fail_tmo or dev_loss_tmo work gets scheduled on the
workqueue executing srp_remove_work() and if an I/O request is
scheduled after the SCSI device had been blocked by e.g. multipathd
then the following deadlock can occur:

kworker/6:1 D ffff880831f3c460 0 195 2 0x00000000
Call Trace:
[<ffffffff814aafd9>] schedule+0x29/0x70
[<ffffffff814aa0ef>] schedule_timeout+0x10f/0x2a0
[<ffffffff8105af6f>] msleep+0x2f/0x40
[<ffffffff8123b0ae>] __blk_drain_queue+0x4e/0x180
[<ffffffff8123d2d5>] blk_cleanup_queue+0x225/0x230
[<ffffffffa0010732>] __scsi_remove_device+0x62/0xe0 [scsi_mod]
[<ffffffffa000ed2f>] scsi_forget_host+0x6f/0x80 [scsi_mod]
[<ffffffffa0002eba>] scsi_remove_host+0x7a/0x130 [scsi_mod]
[<ffffffffa07cf5c5>] srp_remove_work+0x95/0x180 [ib_srp]
[<ffffffff8106d7aa>] process_one_work+0x1ea/0x6c0
[<ffffffff8106dd9b>] worker_thread+0x11b/0x3a0
[<ffffffff810758bd>] kthread+0xed/0x110
[<ffffffff814b972c>] ret_from_fork+0x7c/0xb0
multipathd D ffff880096acc460 0 5340 1 0x00000000
Call Trace:
[<ffffffff814aafd9>] schedule+0x29/0x70
[<ffffffff814aa0ef>] schedule_timeout+0x10f/0x2a0
[<ffffffff814ab79b>] io_schedule_timeout+0x9b/0xf0
[<ffffffff814abe1c>] wait_for_completion_io_timeout+0xdc/0x110
[<ffffffff81244b9b>] blk_execute_rq+0x9b/0x100
[<ffffffff8124f665>] sg_io+0x1a5/0x450
[<ffffffff8124fd21>] scsi_cmd_ioctl+0x2a1/0x430
[<ffffffff8124fef2>] scsi_cmd_blk_ioctl+0x42/0x50
[<ffffffffa00ec97e>] sd_ioctl+0xbe/0x140 [sd_mod]
[<ffffffff8124bd04>] blkdev_ioctl+0x234/0x840
[<ffffffff811cb491>] block_ioctl+0x41/0x50
[<ffffffff811a0df0>] do_vfs_ioctl+0x300/0x520
[<ffffffff811a1051>] SyS_ioctl+0x41/0x80
[<ffffffff814b9962>] tracesys+0xd0/0xd5

Fix this by scheduling removal work on another workqueue than the
transport layer timers.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: David Dillow <dave@thedillows.org>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Avoid problems if a header uses pr_fmt

SRP defines pr_fmt(fmt) to be "PFX fmt", and then includes a bunch of
header files before it gets around to defining PFX. This causes
problems if any of the header files do a pr_... and use pr_fmt().

Fix this by using KBUILD_MODNAME instead of the private PFX.

Acked-by: Chris Metcalf <cmetcalf@tilera.com>

Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Add fast registration support

Certain HCA types (e.g. Connect-IB) and certain configurations (e.g.
ConnectX VF) support fast registration but not FMR. Hence add fast
registration support.

In function srp_rport_reconnect(), move the the srp_finish_req()
loop from after to before the srp_create_target_ib() call. This is
needed to avoid that srp_finish_req() tries to queue any
invalidation requests for rkeys associated with the old queue pair
on the newly allocated queue pair. Invoking srp_finish_req() before
the queue pair has been reallocated is safe since srp_claim_req()
handles completions correctly that arrive after srp_finish_req()
has been invoked.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Rename FMR-related variables

The next patch will cause the renamed variables to be shared between
the code for FMR and for FR memory registration. Make the names of
these variables independent of the memory registration mode. This
patch does not change any functionality. The start of this patch was
the changes applied via the following shell command:

sed -i.orig 's/SRP_FMR_SIZE/SRP_MAX_PAGES_PER_MR/g; \
s/fmr_page_mask/mr_page_mask/g;s/fmr_page_size/mr_page_size/g; \
s/fmr_page_shift/mr_page_shift/g;s/fmr_max_size/mr_max_size/g; \
s/max_pages_per_fmr/max_pages_per_mr/g;s/nfmr/nmdesc/g; \
s/fmr_len/dma_len/g' drivers/infiniband/ulp/srp/ib_srp.[ch]

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: One FMR pool per SRP connection

Allocate one FMR pool per SRP connection instead of one SRP pool
per HCA. This improves scalability of the SRP initiator.

Only request the SCSI mid-layer to retry a SCSI command after a
temporary mapping failure (-ENOMEM) but not after a permanent
mapping failure. This avoids that SCSI commands are retried
indefinitely if a permanent memory mapping failure occurs.

Tell the SCSI mid-layer to reduce queue depth temporarily in the
unlikely case where an application is queuing many requests with
more than max_pages_per_fmr sg-list elements.

For FMR pool allocation, base the max_pages_per_fmr parameter on
the HCA memory registration limit. Only try to allocate an FMR
pool if FMR is supported.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Introduce the 'register_always' kernel module parameter

Add a kernel module parameter that enables memory registration also for SG-lists
that can be processed without memory registration. This makes it easier for kernel
developers to test the memory registration code.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Introduce srp_finish_mapping()

This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Introduce srp_map_fmr()

This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Introduce an additional local variable

This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fix kernel-doc warnings

Avoid that the kernel-doc tool warns about missing argument
descriptions for the ib_srp.[ch] source files.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fix a sporadic crash triggered by cable pulling

Avoid that the loops that iterate over the request ring can encounter
a pointer to a SCSI command in req->scmnd that is no longer associated
with that request. If the function srp_unmap_data() is invoked twice
for a SCSI command that is not in flight then that would cause
ib_fmr_pool_unmap() to be invoked with an invalid pointer as argument,
resulting in a kernel oops.

Reported-by: Sagi Grimberg <sagig@mellanox.com>
Reference: http://thread.gmane.org/gmane.linux.drivers.rdma/19068/focus=19069
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fix a race condition between failing I/O and I/O completion

Avoid that srp_terminate_io() can access req->scmnd after it has been
cleared by the I/O completion code. Do this by protecting req->scmnd
accesses from srp_terminate_io() via locking

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Avoid that writing into "add_target" hangs due to a cable pull

If a cable is pulled while srp_connect_target() is in progress
that can result in that function never to return. That makes the
process, e.g. srp_daemon, that invoked this function unkillable.
Avoid this by letting srp_connect_target() finish if the event
IB_CM_TIMEWAIT_EXIT is received. This patch fixes a hang with the
following call trace:

[<ffffffff814eae85>] schedule_timeout+0x215/0x2e0
[<ffffffff814eab03>] wait_for_common+0x123/0x180
[<ffffffff814eac1d>] wait_for_completion+0x1d/0x20
[<ffffffffa03b398c>] srp_connect_target+0x1dc/0x410 [ib_srp]
[<ffffffffa03b5809>] srp_create_target+0xba9/0xe70 [ib_srp]
[<ffffffff8133e590>] dev_attr_store+0x20/0x30
[<ffffffff811eb8f5>] sysfs_write_file+0xe5/0x170
[<ffffffff811767c8>] vfs_write+0xb8/0x1a0
[<ffffffff811770c1>] sys_write+0x51/0x90
[<ffffffff8100b072>] system_call_fastpath+0x16/0x1b

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Make writing into the "add_target" sysfs attribute interruptible

Avoid that stopping srp_daemon takes unusually long due to a cable
pull by making writing into the "add_target" sysfs attribute
interruptible.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Avoid duplicate connections

The connection uniqueness check is performed before a new connection
is added to the target list. This patch protects both actions by a
mutex such that simultaneous writes from two different threads into the
"add_target" variable do not result in duplicate connections.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Add more logging

Log sgid and dgid when reporting that a login has been rejected or when
a host has been added. This makes it easy to figure out which initiator
and target ports these messages apply to.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Check ib_query_gid return value

Detected by Coverity.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

scsi_transport_srp: Fix a race condition

The rport timers must be stopped before the SRP initiator destroys the
resources associated with the SCSI host. This is necessary because
otherwise the callback functions invoked from the SRP transport layer
could trigger a use-after-free. Stopping the rport timers before
invoking scsi_remove_host() can trigger long delays in the SCSI error
handler if a transport layer failure occurs while scsi_remove_host()
is in progress. Hence move the code for stopping the rport timers from
srp_rport_release() into a new function and invoke that function after
scsi_remove_host() has finished. This patch fixes the following
sporadic kernel crash:

kernel BUG at include/asm-generic/dma-mapping-common.h:64!
invalid opcode: 0000 [#1] SMP
RIP: 0010:[<ffffffffa03b20b1>] [<ffffffffa03b20b1>] srp_unmap_data+0x121/0x130 [ib_srp]
Call Trace:
[<ffffffffa03b20fc>] srp_free_req+0x3c/0x80 [ib_srp]
[<ffffffffa03b2188>] srp_finish_req+0x48/0x70 [ib_srp]
[<ffffffffa03b21fb>] srp_terminate_io+0x4b/0x60 [ib_srp]
[<ffffffffa03a6fb5>] __rport_fail_io_fast+0x75/0x80 [scsi_transport_srp]
[<ffffffffa03a7438>] rport_fast_io_fail_timedout+0x88/0xc0 [scsi_transport_srp]
[<ffffffff8108b370>] worker_thread+0x170/0x2a0
[<ffffffff81090876>] kthread+0x96/0xa0
[<ffffffff8100c0ca>] child_rip+0xa/0x20

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Report receive errors correctly

The IB spec does not guarantee that the opcode is available in error
completions. Hence do not rely on it. See also commit 948d1e889e5b
("IB/srp: Introduce srp_handle_qp_err()").

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: <stable@vger.kernel.org> # v3.8
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Avoid offlining operational SCSI devices

If SCSI commands are submitted with a SCSI request timeout that is
lower than the the IB RC timeout, it can happen that the SCSI error
handler has already started device recovery before transport layer
error handling starts. So it can happen that the SCSI error handler
tries to abort a SCSI command after it has been reset by
srp_rport_reconnect().

Tell the SCSI error handler that such commands have finished and that
it is not necessary to continue its recovery strategy for commands
that have been reset by srp_rport_reconnect().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Remove target from list before freeing Scsi_Host structure

Remove an SRP target from the SRP target list before invoking the last
scsi_host_put() call. This change is necessary because that last put
frees the memory that holds the srp_target_port structure.

This patch prevents the following kernel oops:

RIP: 0010:[<ffffffff810b00d0>] __lock_acquire+0x500/0x1570
Call Trace:
[<ffffffff810b11e4>] lock_acquire+0xa4/0x120
[<ffffffff81531206>] _spin_lock+0x36/0x70
[<ffffffffa01b6d8f>] srp_remove_work+0xef/0x180 [ib_srp]
[<ffffffff8109125c>] worker_thread+0x21c/0x3d0
[<ffffffff81096e86>] kthread+0x96/0xa0
[<ffffffff8100c20a>] child_rip+0xa/0x20

Signed-off-by: Vu Pham <vuhuong@mellanox.com>

[ bvanassche - Modified path description and CC'ed stable. ]

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Add change_queue_depth and change_queue_type support

Currently, it's not possible to change queue depth for a device behind
SRP host. Sometimes, we need to adjust queue_depth for performance
reason (eg storage busy, we need lower queue_depth to avoid running
into SCSI error handler), so this patch add support for SRP driver.

Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Make queue size configurable

Certain storage configurations, e.g. a sufficiently large array of
hard disks in a RAID configuration, need a queue depth above 64 to
achieve optimal performance. Hence make the queue depth configurable.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Tested-by: Jack Wang <xjtuwjp@gmail.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Introduce srp_alloc_req_data()

This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Vu Pham <vu@mellanox.com>
Cc: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Export sgid to sysfs

On an initiator system with multiple IB ports it is not yet possible
to figure out what the originating port of an SRP connection is. Hence
make the source GID available in sysfs.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Add periodic reconnect functionality

After a transport layer occurred, periodically try to reconnect
to the target until the dev_loss timer expires. Protect the
callback functions that can be invoked from inside the SCSI EH
against concurrent invocation with srp_reconnect_rport() via the
rport mutex. Change the default dev_loss_tmo from 60s into 600s
to give the reconnect mechanism a chance to kick in.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

scsi_transport_srp: Add periodic reconnect support

Add support for periodically reconnecting to an SRP target until
the dev_loss timer expires. After the tenth reconnection attempt,
gradually slow down subsequent reconnect attempts.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Start timers if a transport layer error occurs

Start the reconnect timer, fast_io_fail timer and dev_loss timers if a
transport layer error occurs.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Use SRP transport layer error recovery

Enable fast_io_fail_tmo and dev_loss_tmo functionality for the IB SRP
initiator. Add kernel module parameters that allow to specify default
values for these parameters.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Keep rport as long as the IB transport layer

Keep the rport data structure around after srp_remove_host() has
finished until cleanup of the IB transport layer has finished
completely. This is necessary because later patches use the rport
pointer inside the queuecommand callback. Without this patch
accessing the rport from inside a queuecommand callback is racy
because srp_remove_host() must be invoked before scsi_remove_host()
and because the queuecommand callback could get invoked after
srp_remove_host() has finished. In other words, without this patch
the queuecommand callback can get invoked after the rport data
structure has been freed.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Make transport layer retry count configurable

Allow the InfiniBand RC retry count to be configured by the user as an
option in the target login string. Reducing this retry count allows to
reduce the path failover time.

Signed-off-by: Vu Pham <vu@mellanox.com>

[ bvanassche: Rewrote patch description / changed default retry count ]

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Let srp_abort() return FAST_IO_FAIL if TL offline

If the transport layer is offline it is more appropriate to let
srp_abort() return FAST_IO_FAIL instead of SUCCESS.

Reported-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Bump driver version and release date

Signed-off-by: Vu Pham <vu@mellanox.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Make HCA completion vector configurable

Several InfiniBand HCAs allow configuring the completion vector per
CQ. This allows spreading the workload created by IB completion
interrupts over multiple MSI-X vectors and hence over multiple CPU
cores. In other words, configuring the completion vector properly not
only allows reducing latency on an initiator connected to multiple
SRP targets but also allows improving throughput.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Maintain a single connection per I_T nexus

An SRP target is required to maintain a single connection between
initiator and target. This means that if the 'add_target' attribute
is used to create a second connection to a target, the first
connection will be logged out and that the SCSI error handler will
kick in. The SCSI error handler will cause the SRP initiator to
reconnect, which will cause I/O over the second connection to fail.
Avoid such ping-pong behavior by disabling relogins.

If reconnecting manually is necessary, that is possible by deleting
and recreating an rport via sysfs.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fail I/O fast if target offline

If reconnecting failed we know that no command completion will
be received anymore. Hence let the SCSI error handler fail such
commands immediately.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Skip host settle delay

The SRP initiator implements host reset by reconnecting to the SRP
target. That means that communication with the target is possible as
soon as host reset finished. Hence skip the host settle delay.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Avoid skipping srp_reset_host() after a transport error

The SCSI error handler assumes that the transport layer is operational
if an eh_abort_handler() returns SUCCESS. Hence srp_abort() only
should return SUCCESS if sending the ABORT TASK task management
function succeeded. This patch avoids the SCSI error handler skipping
the srp_reset_host() call after a transport layer error.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fix remove_one crash due to resource exhaustion

If the add_one callback fails during driver load no resources are
allocated so there isn't a need to release any resources. Trying
to clean the resource may lead to the following kernel panic:

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffa0132331>] srp_remove_one+0x31/0x240 [ib_srp]
RIP: 0010:[<ffffffffa0132331>] [<ffffffffa0132331>] srp_remove_one+0x31/0x240 [ib_srp]
Process rmmod (pid: 4562, threadinfo ffff8800dd738000, task ffff8801167e60c0)
Call Trace:
[<ffffffffa024500e>] ib_unregister_client+0x4e/0x120 [ib_core]
[<ffffffffa01361bd>] srp_cleanup_module+0x15/0x71 [ib_srp]
[<ffffffff810ac6a4>] sys_delete_module+0x194/0x260
[<ffffffff8100b0f2>] system_call_fastpath+0x16/0x1b

Signed-off-by: Dotan Barak <dotanb@dev.mellanox.co.il>
Reviewed-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fail I/O requests if the transport is offline

If an SRP target is no longer reachable and srp_reset_host() fails to
reconnect then ib_srp will invoke scsi_remove_host(). That function
will invoke __scsi_remove_device() for each LUN. And that last
function will change the device state from SDEV_TRANSPORT_OFFLINE into
SDEV_CANCEL. Certain user space software, e.g. older versions of
multipathd, continue queueing I/O to SCSI devices that are in the
SDEV_CANCEL state.

If these I/O requests are submitted as SG_IO that means that the
REQ_PREEMPT flag will be set and hence that these requests will be
passed to srp_queuecommand(). These requests will time out. If new
requests are queued fast enough from user space these active requests
will prevent __scsi_remove_device() to finish.

Avoid this by failing I/O requests in the SDEV_CANCEL state if the
transport is offline. Introduce a new variable to keep track of the
transport state instead of failing requests if (!target->connected ||
target->qp_in_error), so that the SCSI error handler has a chance to
retry commands after a transport layer failure occurred.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: <stable@vger.kernel.org> # 3.8
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Avoid endless SCSI error handling loop

If a SCSI command times out it is passed to the SCSI error
handler. The SCSI error handler will try to abort the commands that
timed out. If aborting fails, a device reset will be attempted. If
the device reset also fails a host reset will be attempted. If the
host reset also fails the whole procedure will be repeated.

srp_abort() and srp_reset_device() fail for a QP in the error state.
srp_reset_host() fails after host removal has started. Hence if the
SCSI error handler gets invoked after host removal has started and
with the QP in the error state an endless loop will be triggered.

Modify the SCSI error handling functions in ib_srp as follows:
- Abort SCSI commands properly even if the QP is in the error state.
- Make srp_reset_host() reset SCSI requests even after host removal
has already started or if reconnecting fails.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dave@thedillows.org>
Cc: <stable@vger.kernel.org> # 3.8
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Avoid sending a task management function needlessly

Do not send a task management function if sending will fail anyway
because either there is no RDMA/RC connection or the QP is in the
error state.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dave@thedillows.org>
Cc: <stable@vger.kernel.org> # 3.8
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Track connection state properly

Remove an assignment that incorrectly overwrites the connection state
update by srp_connect_target().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dave@thedillows.org>
Cc: <stable@vger.kernel.org> # 3.8
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Allow SRP disconnect through sysfs

Make it possible to disconnect the IB RC connection used by the SRP
protocol to communicate with a target.

Have the SRP transport layer create a sysfs "delete" attribute for
initiator drivers that support this functionality.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: send disconnect request without waiting for CM timewait exit

Now that SRP recreates the CM ID, QP, and CQ for each connection,
there is no need to wait for the timewait state to complete.

Signed-off-by: Vu Pham <vu@mellanox.com>
Signed-off-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: destroy and recreate QP and CQs when reconnecting

HW QP FATAL errors persist over a reset operation, but we can recover
from that by recreating the QP and associated CQs for each connection.
Creating a new QP/CQ also completely forecloses any possibility of
getting stale completions or packets on the new connection.

Signed-off-by: Ishai Rabinovitz <ishai@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>

[ updated to current code from OFED, cleaned up commit message ]

Signed-off-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Eliminate state SRP_TARGET_DEAD

Only queue removal work after having changed the target state
into SRP_TARGET_REMOVED and not if that state was already equal
to SRP_TARGET_REMOVED. That allows us to remove the state
SRP_TARGET_DEAD. Add a call to srp_disconnect_target() in
srp_remove_target() -- due to previous changes it is now safe to
invoke that function even if the IB connection has already
been disconnected. This change allows us to replace the target
removal code in srp_remove_one() by an (indirect) call to
srp_remove_target(). Rename srp_target_port.work into
srp_target_port.remove_work to reflect its usage.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Introduce the helper function srp_remove_target()

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Suppress superfluous error messages

Keep track of the connection state. Only report QP errors while
connected. Only invoke ib_send_cm_dreq() when connected so that
invoking srp_disconnect_target() after having received a DREQ does not
cause an error message to be printed.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Process all error completions

If the RDMA RC connection is closed, tell the SCSI mid-layer to
terminate all pending commands instead of only the first.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Introduce srp_handle_qp_err()

Introduce the function srp_handle_qp_err(), change the type of
qp_in_error from int into bool and move the initialization of that
variable from srp_reconnect_target() to srp_connect_target().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Simplify SCSI error handling

Since scsi_remove_host() has been modified so that SCSI error handling
functions will no longer be invoked after scsi_remove_host() returns,
the test at the start of srp_send_tsk_mgmt() is now superfluous.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Keep processing commands during host removal

Some SCSI upper layer drivers, e.g. sd, issue SCSI commands from
inside scsi_remove_host() (see the sd_shutdown() call in sd_remove()).
Make sure that these commands have a chance to reach the SCSI device.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Eliminate state SRP_TARGET_CONNECTING

Block the SCSI host while reconnecting instead of representing the
reconnection activity as a distinct SRP target state. This allows us
to eliminate the target state SRP_TARGET_CONNECTING.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Increase block layer timeout

Increase the block layer timeout for disks so that it is above the
InfiniBand transport layer timeout.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Avoid having aborted requests hang

We need to call scsi_done() for commands after we abort them.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fix use-after-free in srp_reset_req()

srp_free_req() uses the scsi_cmnd structure contents to unmap
buffers, so we must invoke srp_free_req() before we release
ownership of that structure.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fix a race condition

Avoid a crash caused by the scmnd->scsi_done(scmnd) call in
srp_process_rsp() being invoked with scsi_done == NULL. This can
happen if a reply is received during or after a command abort.

Reported-by: Joseph Glanville <joseph.glanville@orionvm.com.au>
Reference: http://marc.info/?l=linux-rdma&m=134314367801595
Cc: <stable@vger.kernel.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Consolidate repetitive sysfs code

Remove sysfs attributes before removing a target instead of testing
the target state in every sysfs attribute callback method. Note: it is
safe to invoke a sysfs attribute removal method like
device_remove_file() twice on the same attribute.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Use pr_fmt() and pr_err()/pr_warn()

Use pr_fmt() and pr_xxx() instead of more verbose printk() equivalents.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

atomic: use <linux/atomic.h>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/srp: Avoid duplicate devices from LUN scan

SCSI scanning of a channel:id:lun triplet in Linux works as follows
(function scsi_scan_target() in drivers/scsi/scsi_scan.c):

- If lun == SCAN_WILD_CARD, send a REPORT LUNS command to the target
and process the result.

- If lun != SCAN_WILD_CARD, send an INQUIRY command to the LUN
corresponding to the specified channel:id:lun triplet to verify
whether the LUN exists.

So a SCSI driver must either take the channel and target id values in
account in its quecommand() function or it should declare that it only
supports one channel and one target id.

Currently the ib_srp driver does neither. As a result scanning the
SCSI bus via e.g. rescan-scsi-bus.sh causes many duplicate SCSI
devices to be created. For each 0:0:L device, several duplicates are
created with the same LUN number and with (C:I) != (0:0). Fix this by
declaring that the ib_srp driver only supports one channel and one
target id.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: <stable@kernel.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

IB/srp: Fix integer -> pointer cast warnings

Fix

drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_handle_recv':
drivers/infiniband/ulp/srp/ib_srp.c:1150: warning: cast to pointer from integer of different size
drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_send_completion':
drivers/infiniband/ulp/srp/ib_srp.c:1234: warning: cast to pointer from integer of different size

by adding an intermediate cast to uintptr_t.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Acked-by: David Dillow <dillowda@ornl.gov>

IB/srp: try to use larger FMR sizes to cover our mappings

Now that we can get larger SG lists, we can take advantage of HCAs that
allow us to use larger FMR sizes. In many cases, we can use up to 512
entries, so start there and work our way down.

Signed-off-by: David Dillow <dillowda@ornl.gov>

IB/srp: add support for indirect tables that don't fit in SRP_CMD

This allows us to guarantee the ability to submit up to 8 MB requests
based on the current value of SCSI_MAX_SG_CHAIN_SEGMENTS. While FMR will
usually condense the requests into 8 SG entries, it is imperative that
the target support external tables in case the FMR mapping fails or is
not supported.

We add a safety valve to allow targets without the needed support to
reap the benefits of the large tables, but fail in a manner that lets
the user know that the data didn't make it to the device. The user must
add "allow_ext_sg=1" to the target parameters to indicate that the
target has the needed support.

If indirect_sg_entries is not specified in the modules options, then
the sg_tablesize for the target will default to cmd_sg_entries unless
overridden by the target options.

Signed-off-by: David Dillow <dillowda@ornl.gov>

IB/srp: rework mapping engine to use multiple FMR entries

Instead of forcing all of the S/G entries to fit in one FMR, and falling
back to indirect descriptors if that fails, allow the use of as many
FMRs as needed to map the request. This lays the groundwork for allowing
indirect descriptor tables that are larger than can fit in the command
IU, but should marginally improve performance now by reducing the number
of indirect descriptors needed.

We increase the minimum page size for the FMR pool to 4K, as larger
pages help increase the coverage of each FMR, and it is rare that the
kernel would send down a request with scattered 512 byte fragments.

This patch also move some of the target initialization code afte the
parsing of options, to keep it together with the new code that needs to
allocate memory based on the options given.

Signed-off-by: David Dillow <dillowda@ornl.gov>

IB/srp: allow sg_tablesize to be set for each target

Different configurations of target software allow differing max sizes of
the command IU. Allowing this to be changed per-target allows all
targets on an initiator to get an optimal setting.

We deprecate srp_sg_tablesize and replace it with cmd_sg_entries in
preparation for allowing more indirect descriptors than can fit in the
IU.

Signed-off-by: David Dillow <dillowda@ornl.gov>

IB/srp: move IB CM setup completion into its own function

This is to clean up prior to further changes.

Signed-off-by: David Dillow <dillowda@ornl.gov>

IB/srp: always avoid non-zero offsets into an FMR

It is unclear exactly how this code works around Mellanox SRP targets,
or if the problem is on the target side or in the HCA itself. In an
abundance of caution, we should always enable the workaround.

Signed-off-by: David Dillow <dillowda@ornl.gov>

RDMA: Update workqueue usage

* ib_wq is added, which is used as the common workqueue for infiniband
instead of the system workqueue. All system workqueue usages
including flush_scheduled_work() callers are converted to use and
flush ib_wq.

* cancel_delayed_work() + flush_scheduled_work() converted to
cancel_delayed_work_sync().

* qib_wq is removed and ib_wq is used instead.

This is to prepare for deprecation of flush_scheduled_work().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/srp: Test only once whether iu allocation succeeded

Merge the two tests in srp_queuecommand() of whether information unit
allocation succeeded into one. An intended side effect of this change
is that we fix the warning:

drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_queuecommand':
drivers/infiniband/ulp/srp/ib_srp.c:1116: warning: 'req' may be used uninitialized in this function

(seen with CONFIG_CC_OPTIMIZE_FOR_SIZE=y at least with gcc 4.4.4)

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

IB/srp: consolidate hot-path variables into cache lines

Put the variables accessed together in the hot-path into common
cachelines, and separate them by RW vs RO to avoid false dirtying.
We keep a local copy of the lkey and rkey in the target to avoid
traversing pointers (and associated cache lines) to find them.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: David Dillow <dillowda@ornl.gov>

IB/srp: stop sharing the host lock with SCSI

We don't need protection against the SCSI stack, so use our own lock to
allow parallel progress on separate CPUs.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
[ broken out and small cleanups by David Dillow ]
Signed-off-by: David Dillow <dillowda@ornl.gov>

IB/srp: reduce lock coverage of command completion

We only need the lock to cover list and credit manipulations, so push
those into srp_remove_req() and update the call chains.

We reorder the request removal and command completion in
srp_process_rsp() to avoid the SCSI mid-layer sending another command
before we've released our request and added any credits returned by the
target. This prevents us from returning HOST_BUSY unneccesarily.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
[ broken out, small cleanups, and modified to avoid potential extraneous
HOST_BUSY returns by David Dillow ]
Signed-off-by: David Dillow <dillowda@ornl.gov>