scsi: scsi_dh_alua: Fix memleak for 'qdata' in alua_activate()

If alua_rtpg_queue() failed from alua_activate(), then 'qdata' is not
freed, which will cause following memleak:

unreferenced object 0xffff88810b2c6980 (size 32):
comm "kworker/u16:2", pid 635322, jiffies 4355801099 (age 1216426.076s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
40 39 24 c1 ff ff ff ff 00 f8 ea 0a 81 88 ff ff @9$.............
backtrace:
[<0000000098f3a26d>] alua_activate+0xb0/0x320
[<000000003b529641>] scsi_dh_activate+0xb2/0x140
[<000000007b296db3>] activate_path_work+0xc6/0xe0 [dm_multipath]
[<000000007adc9ace>] process_one_work+0x3c5/0x730
[<00000000c457a985>] worker_thread+0x93/0x650
[<00000000cb80e628>] kthread+0x1ba/0x210
[<00000000a1e61077>] ret_from_fork+0x22/0x30

Fix the problem by freeing 'qdata' in error path.

Fixes: 625fe857e4fa ("scsi: scsi_dh_alua: Check scsi_device_get() return value")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20230315062154.668812-1-yukuai1@huaweicloud.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh: Convert to scsi_execute_cmd()

scsi_execute() is going to be removed. Convert the scsi_dh users to
scsi_execute_cmd().

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: device_handler: alua: Remove a might_sleep() annotation

The might_sleep() annotation in alua_rtpg_queue() is not correct since the
command completion code may call this function from atomic context.
Calling alua_rtpg_queue() from atomic context in the command completion
path is fine since request submitters must hold an sdev reference until
command execution has completed. This patch fixes the following kernel
complaint:

BUG: sleeping function called from invalid context at drivers/scsi/device_handler/scsi_dh_alua.c:992
Call Trace:
dump_stack_lvl+0xac/0x100
__might_resched+0x284/0x2c8
alua_rtpg_queue+0x3c/0x98 [scsi_dh_alua]
alua_check+0x122/0x250 [scsi_dh_alua]
alua_check_sense+0x172/0x228 [scsi_dh_alua]
scsi_check_sense+0x8a/0x2e0
scsi_decide_disposition+0x286/0x298
scsi_complete+0x6a/0x108
blk_complete_reqs+0x6e/0x88
__do_softirq+0x13e/0x6b8
__irq_exit_rcu+0x14a/0x170
irq_exit_rcu+0x22/0x50
do_ext_irq+0x10a/0x1d0

Link: https://lore.kernel.org/r/20230118180557.1212577-1-bvanassche@acm.org
Reported-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Tested-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: device_handler: alua: Call scsi_device_put() from non-atomic context

Since commit f93ed747e2c7 ("scsi: core: Release SCSI devices
synchronously"), scsi_device_put() might sleep. Avoid calling it from
alua_rtpg_queue() with the pg_lock held. The lock only pretects h->pg,
anyway. To avoid the pg being freed under us, because of a race with
another thread, take a temporary reference. In alua_rtpg_queue(), verify
that the pg still belongs to the sdev being passed before actually queueing
the RTPG.

This patch fixes the following smatch warning:

drivers/scsi/device_handler/scsi_dh_alua.c:1013 alua_rtpg_queue() warn: sleeping in atomic context

alua_check_vpd() <- disables preempt
-> alua_rtpg_queue()
-> scsi_device_put()

Cc: Martin Wilck <mwilck@suse.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sachin Sant <sachinp@linux.ibm.com>
Cc: Benjamin Block <bblock@linux.ibm.com>
Suggested-by: Martin Wilck <mwilck@suse.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221117183626.2656196-3-bvanassche@acm.org
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: device_handler: alua: Revert "Move a scsi_device_put() call out of alua_check_vpd()"

There is a bug in commit 0b25e17e9018 ("scsi: alua: Move a
scsi_device_put() call out of alua_check_vpd()"): that patch may cause
alua_rtpg_queue() callers to call scsi_device_put() even if that function
should not be called. Revert that commit to prepare for a different
solution.

Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin Wilck <mwilck@suse.com>
Cc: Sachin Sant <sachinp@linux.ibm.com>
Cc: Benjamin Block <bblock@linux.ibm.com>
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Reported-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221117183626.2656196-2-bvanassche@acm.org
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: alua: Move a scsi_device_put() call out of alua_rtpg_select_sdev()

Move a scsi_device_put() call from alua_rtpg_select_sdev() to its
callers. Fixes the following smatch complaint:

drivers/scsi/device_handler/scsi_dh_alua.c:853 alua_rtpg_select_sdev() warn: sleeping in atomic context

alua_rtpg_work() <- disables preempt
-> alua_rtpg_select_sdev()
-> scsi_device_put()

Cc: Hannes Reinecke <hare@suse.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221031224728.2607760-3-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: alua: Move a scsi_device_put() call out of alua_check_vpd()

Fix the following smatch warning:

drivers/scsi/device_handler/scsi_dh_alua.c:1013 alua_rtpg_queue() warn: sleeping in atomic context

alua_check_vpd() <- disables preempt
-> alua_rtpg_queue()
-> scsi_device_put()

Cc: Hannes Reinecke <hare@suse.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221031224728.2607760-2-bvanassche@acm.org
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi/device_handlers: Use the new blk_opf_t type

Improve static type checking by using the new blk_opf_t type for variables
that represent request flags.

Cc: Hannes Reinecke <hare@suse.com>
Cc: Martin Wilck <mwilck@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-43-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: scsi_dh_alua: Properly handle the ALUA transitioning state

The handling of the ALUA transitioning state is currently broken. When a
target goes into this state, it is expected that the target is allowed to
stay in this state for the implicit transition timeout without a path
failure. The handler has this logic, but it gets skipped currently.

When the target transitions, there is in-flight I/O from the initiator. The
first of these responses from the target will be a unit attention letting
the initiator know that the ALUA state has changed. The remaining
in-flight I/Os, before the initiator finds out that the portal state has
changed, will return not ready, ALUA state is transitioning. The portal
state will change to SCSI_ACCESS_STATE_TRANSITIONING. This will lead to all
new I/O immediately failing the path unexpectedly. The path failure happens
in less than a second instead of the expected successes until the
transition timer is exceeded.

Allow I/Os to continue while the path is in the ALUA transitioning
state. The handler already takes care of a target that stays in the
transitioning state for too long by changing the state to ALUA state
standby once the transition timeout is exceeded at which point the path
will fail.

Link: https://lore.kernel.org/r/CAHZQxy+4sTPz9+pY3=7VJH+CLUJsDct81KtnR2be8ycN5mhqTg@mail.gmail.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Krishna Kant <krishna.kant@purestorage.com>
Acked-by: Seamus Connor <sconnor@purestorage.com>
Signed-off-by: Brian Bunker <brian@purestorage.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Fix signedness bug in alua_rtpg()

The "retval" variable needs to be signed for the error handling to work.

Link: https://lore.kernel.org/r/YLjMEAFNxOas1mIp@mwanda
Fixes: 7e26e3ea0287 ("scsi: scsi_dh_alua: Check for negative result value")
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Check for negative result value

scsi_execute() will now return a negative error if there was an error prior
to command submission; evaluate that instead if checking for DRIVER_ERROR.

[mkp: build fix]

Link: https://lore.kernel.org/r/20210427083046.31620-6-hare@suse.de
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Retry RTPG on a different path after failure

If an RTPG fails, we can't infer anything wrt. the state of the ports in
the port group except that we were unable to reach the one port on which
the RTPG had failed. "offline" is just a secondary port state, which means
that we can't infer the state of any port in the PG from the failure (in
fact, even the failed port might still be in "active/optimized" primary
port access state).

Therefore, when we encounter an RTPG failure, we should retry the RTPG on a
different port. This avoids falsely setting port states to offline for
unreachable ports. To do this, ports on which an RTPG has failed are
temporarily set to "disabled" to avoid repeating the failed I/O on the same
target port. Once the RTPG has either succeeded on one port or failed on
all ports of the PG, the ports are enabled again.

Link: https://lore.kernel.org/r/20210514153214.5626-1-mwilck@suse.com
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Introduce enum scsi_disposition

Improve readability of the code in the SCSI core by introducing an
enumeration type for the values used internally that decide how to continue
processing a SCSI command. The eh_*_handler return values have not been
changed because that would involve modifying all SCSI drivers.

The output of the following command has been inspected to verify that no
out-of-range values are assigned to a variable of type enum
scsi_disposition:

KCFLAGS=-Wassign-enum make CC=clang W=1 drivers/scsi/

Link: https://lore.kernel.org/r/20210415220826.29438-6-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Remove check for ASC 24h in alua_rtpg()

Some arrays return ILLEGAL_REQUEST with ASC 00h if they don't support the
RTPG extended header so remove the check for INVALID FIELD IN CDB.

Link: https://lore.kernel.org/r/20210331201154.20348-1-emilne@redhat.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Prevent duplicate pg info print in alua_rtpg()

Due to the frequency that alua_rtpg() is called, the path group info print
within can print the same info multiple times in the logs, subsequent
prints adding no new information or value.

To reproduce:

# modprobe scsi_debug vpd_use_hostno=0
# systemctl start multipathd.service

To fix, check stored values, only printing at alua attach/activate and if
any of the values change.

Link: https://lore.kernel.org/r/20210331181656.5046-1-jpittman@redhat.com
Reviewed-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: John Pittman <jpittman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Set 'transitioning' state on Unit Attention

We should be setting the 'transitioning' ALUA state once we get a Unit
Attention indicating the array is in transitioning. There are arrays which
cannot respond to an RTPG while in transitioning, and others have issues
correctly reporting the state. So better to set the state during Unit
Attention handling and wait for TUR / RTPG to run its course.

Link: https://lore.kernel.org/r/20200930080256.90964-4-hare@suse.de
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Return BLK_STS_AGAIN for ALUA transitioning state

When the ALUA state indicates transitioning we should not retry the command
immediately, but rather complete the command with BLK_STS_AGAIN to signal
the completion handler that it might be retried. This allows multipathing
to redirect the command to another path if possible, and avoid stalls
during lengthy transitioning times.

Link: https://lore.kernel.org/r/20200930080256.90964-3-hare@suse.de
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Avoid crash during alua_bus_detach()

alua_bus_detach() might be running concurrently with alua_rtpg_work(), so
we might trip over h->sdev == NULL and call BUG_ON(). The correct way of
handling it is to not set h->sdev to NULL in alua_bus_detach(), and call
rcu_synchronize() before the final delete to ensure that all concurrent
threads have left the critical section. Then we can get rid of the
BUG_ON() and replace it with a simple if condition.

Link: https://lore.kernel.org/r/1600167537-12509-1-git-send-email-jitendra.khasdev@oracle.com
Link: https://lore.kernel.org/r/20200924104559.26753-1-hare@suse.de
Cc: Brian Bunker <brian@purestorage.com>
Acked-by: Brian Bunker <brian@purestorage.com>
Tested-by: Jitendra Khasdev <jitendra.khasdev@oracle.com>
Reviewed-by: Jitendra Khasdev <jitendra.khasdev@oracle.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: handle RTPG sense code correctly during state transitions

Some arrays are not capable of returning RTPG data during state
transitioning, but rather return an 'LUN not accessible, asymmetric access
state transition' sense code. In these cases we can set the state to
'transitioning' directly and don't need to evaluate the RTPG data (which we
won't have anyway).

Link: https://lore.kernel.org/r/20191007135701.32389-1-hare@suse.de
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: always use a 2 second delay before retrying RTPG

Retrying immediately after we've received a 'transitioning' sense code is
pretty much pointless, we should always use a delay before retrying. So
ensure the default delay is applied before retrying.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Tested-by: Zhangguanghui <zhang.guanghui@h3c.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: scsi_dh_alua: Fix possible null-ptr-deref

If alloc_workqueue fails in alua_init, it should return -ENOMEM, otherwise
it will trigger null-ptr-deref while unloading module which calls
destroy_workqueue dereference
wq->lock like this:

BUG: KASAN: null-ptr-deref in __lock_acquire+0x6b4/0x1ee0
Read of size 8 at addr 0000000000000080 by task syz-executor.0/7045

CPU: 0 PID: 7045 Comm: syz-executor.0 Tainted: G C 5.1.0+ #28
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1
Call Trace:
dump_stack+0xa9/0x10e
__kasan_report+0x171/0x18d
? __lock_acquire+0x6b4/0x1ee0
kasan_report+0xe/0x20
__lock_acquire+0x6b4/0x1ee0
lock_acquire+0xb4/0x1b0
__mutex_lock+0xd8/0xb90
drain_workqueue+0x25/0x290
destroy_workqueue+0x1f/0x3f0
__x64_sys_delete_module+0x244/0x330
do_syscall_64+0x72/0x2a0
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 03197b61c5ec ("scsi_dh_alua: Use workqueue for RTPG")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: return blk_status_t from device handler ->prep_fn

Remove the last use of the old BLKPREP_* values, which get converted
to BLK_STS_* later anyway.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: scsi_dh_alua: Correct comment for alua_alloc_pg()

In the comment for function alua_alloc_pg() the argument '@h' is
mistakenly referred to. Fix this by replacing it with the correct
argument reference, '@tpgs', and provide a short description.

Signed-off-by: John Pittman <jpittman@redhat.com>
Reviewed-by Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: device_handler: remove VLAs

In preparation to enabling -Wvla, remove VLAs and replace them with
fixed-length arrays instead.

scsi_dh_{alua,emc,rdac} use variable-length array declarations to store
command blocks, with the appropriate size as determined by
COMMAND_SIZE. This patch replaces these with fixed-sized arrays using
MAX_COMMAND_SIZE, so that the array size can be determined at compile
time.

This was prompted by https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Stephen Kitt <steve@sk2.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh: Document alua_rtpg_queue() arguments

Since commit 3a025e1d1c2e ("Add optional check for bad kernel-doc
comments") building with W=1 causes warnings to appear for issues in
kernel-doc headers. This patch avoids that the following warnings are
reported when building with W=1:

drivers/scsi/device_handler/scsi_dh_alua.c:867: warning: No description found for parameter 'pg'
drivers/scsi/device_handler/scsi_dh_alua.c:867: warning: No description found for parameter 'sdev'
drivers/scsi/device_handler/scsi_dh_alua.c:867: warning: No description found for parameter 'qdata'
drivers/scsi/device_handler/scsi_dh_alua.c:867: warning: No description found for parameter 'force'

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: skip RTPG for devices only supporting active/optimized

For hardware only supporting active/optimized there's no point in ever
re-issuing RTPG as the only new state we can possibly read is
active/optimized. This avoid spurious errors during path failover on
such arrays.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh: Return SCSI_DH_XX error code from ->attach()

Rather than having each device handler implementing their own error
mapping, have the ->attach() call return a SCSI_DH_XXX error code and
implement the mapping in scsi_dh_handler_attach().

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: remove synchronous STPG support

Since 9c58b395 ("scsi: scsi_devinfo: remove synchronous ALUA for NETAPP
devices") this code is unused.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Warn if the first argument of alua_rtpg_queue() is NULL

Callers must provide a valid port group to alua_rtpg_queue(). Issue a
kernel warning if that is not the case.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Ensure that alua_activate() calls the completion function

Callers of scsi_dh_activate(), e.g. dm-mpath, assume that this function
either returns an error code or calls the completion function. Make
alua_activate() call the completion function even if scsi_device_get()
fails.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Tang Junhui <tang.junhui@zte.com.cn>
Cc: <stable@vger.kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Check scsi_device_get() return value

Do not queue ALUA work nor call scsi_device_put() if the
scsi_device_get() call fails. This patch fixes the following crash:

general protection fault: 0000 [#1] SMP
RIP: 0010:scsi_device_put+0xb/0x30
Call Trace:
scsi_disk_put+0x2d/0x40
sd_release+0x3d/0xb0
__blkdev_put+0x29e/0x360
blkdev_put+0x49/0x170
dm_put_table_device+0x58/0xc0 [dm_mod]
dm_put_device+0x70/0xc0 [dm_mod]
free_priority_group+0x92/0xc0 [dm_multipath]
free_multipath+0x70/0xc0 [dm_multipath]
multipath_dtr+0x19/0x20 [dm_multipath]
dm_table_destroy+0x67/0x120 [dm_mod]
dev_suspend+0xde/0x240 [dm_mod]
ctl_ioctl+0x1f5/0x520 [dm_mod]
dm_ctl_ioctl+0xe/0x20 [dm_mod]
do_vfs_ioctl+0x8f/0x700
SyS_ioctl+0x3c/0x70
entry_SYSCALL_64_fastpath+0x18/0xad

Fixes: commit 03197b61c5ec ("scsi_dh_alua: Use workqueue for RTPG")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Tang Junhui <tang.junhui@zte.com.cn>
Cc: <stable@vger.kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove scsi_execute_req_flags

And switch all callers to use scsi_execute instead.

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

scsi: scsi_dh_alua: Fix RCU annotations

This patch avoids that sparse complains about RCU pointer dereferences.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: tang.junhui <tang.junhui@zte.com.cn>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: Fix a reference counting bug

The code at the end of alua_rtpg_work() is as follows:

scsi_device_put(sdev);
kref_put(&pg->kref, release_port_group);

In other words, alua_rtpg_queue() must hold an sdev reference and a pg
reference before queueing rtpg work. If no rtpg work is queued no
additional references should be held when alua_rtpg_queue() returns. If
no rtpg work is queued, ensure that alua_rtpg_queue() only gives up the
sdev reference if that reference was obtained by the same
alua_rtpg_queue() call.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reported-by: Tang Junhui <tang.junhui@zte.com.cn>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Tang Junhui <tang.junhui@zte.com.cn>
Cc: <stable@vger.kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_alua: fix missing kref_put() in alua_rtpg_work()

Reference count of pg leaks in alua_rtpg_work() since kref_put() is not
called to decrease the reference count of pg when the condition
pg->rtpg_sdev==NULL satisfied (actually it is easy to satisfy), it would
cause memory of pg leakage.

Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Cc: <stable@vger.kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: split out request-only flags into a new namespace

A lot of the REQ_* flags are only used on struct requests, and only of
use to the block layer and a few drivers that dig into struct request
internals.

This patch adds a new req_flags_t rq_flags field to struct request for
them, and thus dramatically shrinks the number of common requests. It
also removes the unfortunate situation where we have to fit the fields
from the same enum into 32 bits for struct bio and 64 bits for
struct request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

scsi: scsi_dh_alua: Fix memory leak in alua_rtpg()

buff should be freed before returning with SCSI_DH_RETRY in alua_rtpg().

Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: do not fail for unknown VPD identification

Not every device will return a useable VPD identification, but still
might support ALUA. Rather than disable ALUA support we should be
allowing the device identification to be empty and attach individual
ALUA device handler to each devices.

[mkp: Fixed typo reported by Bart]

Reported-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Tested-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: uninitialized variable in alua_rtpg()

It's possible to use "err" without initializing it. If it happens to be
a 2 which is SCSI_DH_RETRY then that could cause a bug. Bart Van Assche
pointed out that we should probably re-initialize it for every iteration
through the retry loop.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <jejb@linux.vnet.ibm.com>

scsi_dh_alua: Declare local functions static

This patch avoids that building with W=1 causes gcc to report the
following type of warning:

no previous prototype for ... [-Wmissing-prototypes]

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ewan Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: Fix a recently introduced deadlock

While retesting the SRP initiator I ran the command "rmmod mlx4_ib"
while I/O was in progress. That command triggers SCSI device removal
indirectly. Avoid that this action triggers the following deadlock:

=================================
[ INFO: inconsistent lock state ]
4.6.0-rc0-dbg+ #2 Tainted: G O
---------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
multipathd/484 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&(&pg->lock)->rlock){+.?...}, at: [<ffffffffa04f50a2>] alua_bus_detach+0x52/0xa0 [scsi_dh_alua]
{IN-SOFTIRQ-W} state was registered at:
[<ffffffff810a64a9>] __lock_acquire+0x7e9/0x1ad0
[<ffffffff810a7fd0>] lock_acquire+0x60/0x80
[<ffffffff8159910e>] _raw_spin_lock_irqsave+0x3e/0x60
[<ffffffffa04f5131>] alua_rtpg_queue+0x41/0x1d0 [scsi_dh_alua]
[<ffffffffa04f5531>] alua_check+0xe1/0x220 [scsi_dh_alua]
[<ffffffffa04f5709>] alua_check_sense+0x99/0xb0 [scsi_dh_alua]
[<ffffffff813f0d01>] scsi_check_sense+0x71/0x3f0
[<ffffffff813f2f8b>] scsi_decide_disposition+0x18b/0x1d0
[<ffffffff813f6e52>] scsi_softirq_done+0x52/0x140
[<ffffffff812a26f2>] blk_done_softirq+0x52/0x90
[<ffffffff8105bc1f>] __do_softirq+0x10f/0x230
[<ffffffff8105bec8>] irq_exit+0xa8/0xb0
[<ffffffff8101a675>] do_IRQ+0x65/0x110
[<ffffffff8159a2c9>] ret_from_intr+0x0/0x19
[<ffffffff811732f1>] kmem_cache_alloc+0x151/0x190
[<ffffffff8118e534>] create_object+0x34/0x2d0
[<ffffffff8158eaa6>] kmemleak_alloc_percpu+0x56/0xd0
[<ffffffff8113ab0d>] pcpu_alloc+0x38d/0x660
[<ffffffff8113aded>] __alloc_percpu_gfp+0xd/0x10
[<ffffffff812e56a5>] __percpu_counter_init+0x55/0xb0
[<ffffffff812b4989>] blkg_alloc+0x79/0x230
[<ffffffff812b6756>] blkcg_init_queue+0x26/0x1d0
[<ffffffff81297eed>] blk_alloc_queue_node+0x27d/0x2e0
[<ffffffffa017766c>] dm_create+0x20c/0x570 [dm_mod]
[<ffffffffa017e356>] dev_create+0x56/0x2c0 [dm_mod]
[<ffffffffa017dcae>] ctl_ioctl+0x26e/0x520 [dm_mod]
[<ffffffffa017df6e>] dm_ctl_ioctl+0xe/0x20 [dm_mod]
[<ffffffff811aa8ee>] do_vfs_ioctl+0x8e/0x660
[<ffffffff811aaefc>] SyS_ioctl+0x3c/0x70
[<ffffffff81599929>] entry_SYSCALL_64_fastpath+0x1c/0xac
irq event stamp: 4290931
hardirqs last enabled at (4290931): [ 1662.892772]
[<ffffffff81599341>] _raw_spin_unlock_irqrestore+0x31/0x50
hardirqs last disabled at (4290930): [<ffffffff815990e7>] _raw_spin_lock_irqsave+0x17/0x60
softirqs last enabled at (4290774): [<ffffffff8105bcdb>] __do_softirq+0x1cb/0x230
softirqs last disabled at (4289831): [<ffffffff8105bec8>] irq_exit+0xa8/0xb0

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&(&pg->lock)->rlock);
<Interrupt>
lock(&(&pg->lock)->rlock);

*** DEADLOCK ***

2 locks held by multipathd/484:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff811d1cc3>] __blkdev_put+0x33/0x360
#1: (sd_ref_mutex){+.+...}, at: [<ffffffff81400afc>] scsi_disk_put+0x1c/0x40

stack backtrace:
CPU: 6 PID: 484 Comm: multipathd Tainted: G O 4.6.0-rc0-dbg+ #2
Call Trace:
[<ffffffff812bd115>] dump_stack+0x67/0x92
[<ffffffff810a5175>] print_usage_bug+0x215/0x240
[<ffffffff810a56ea>] mark_lock+0x54a/0x610
[<ffffffff810a6505>] __lock_acquire+0x845/0x1ad0
[<ffffffff810a7fd0>] lock_acquire+0x60/0x80
[<ffffffff81598f23>] _raw_spin_lock+0x33/0x50
[<ffffffffa04f50a2>] alua_bus_detach+0x52/0xa0 [scsi_dh_alua]
[<ffffffff813ff6f7>] scsi_dh_release_device+0x17/0x50
[<ffffffff813fb8da>] scsi_device_dev_release_usercontext+0x2a/0x120
[<ffffffff810701f0>] execute_in_process_context+0x80/0x90
[<ffffffff813fb8a7>] scsi_device_dev_release+0x17/0x20
[<ffffffff813c8cfd>] device_release+0x2d/0x90
[<ffffffff812bfa8a>] kobject_release+0x7a/0x190
[<ffffffff812bf946>] kobject_put+0x26/0x50
[<ffffffff813c8ee2>] put_device+0x12/0x20
[<ffffffff813edc86>] scsi_device_put+0x26/0x30
[<ffffffff81400b0d>] scsi_disk_put+0x2d/0x40
[<ffffffff81400b68>] sd_release+0x48/0xb0
[<ffffffff811d1f2e>] __blkdev_put+0x29e/0x360
[<ffffffff811d24b9>] blkdev_put+0x49/0x170
[<ffffffff811d2600>] blkdev_close+0x20/0x30
[<ffffffff81198f48>] __fput+0xe8/0x1f0
[<ffffffff81199089>] ____fput+0x9/0x10
[<ffffffff81075d9e>] task_work_run+0x6e/0xa0
[<ffffffff81001119>] exit_to_usermode_loop+0xa9/0xb0
[<ffffffff81001590>] syscall_return_slowpath+0xb0/0xc0
[<ffffffff815999b7>] entry_SYSCALL_64_fastpath+0xaa/0xac

Fixes: cb0a168cb6b8 (scsi_dh_alua: update 'access_state' field)
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: uninitialized variable in alua_check_vpd()

The pg_updated variable is support to be set to false at the start but
it is uninitialized.

Fixes: cb0a168cb6b8 ('scsi_dh_alua: update 'access_state' field')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: update 'access_state' field

Track attached SCSI devices and update the 'access_state' field whenever
an ALUA state change has been detected.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: use common definitions for ALUA state

scsi_proto.h now contains definitions for the ALUA state, so we don't
have to carry them in the device handler.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: Update version to 2.0

[mkp: Fixed merge due to patches 20-22 of series being postponed]

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

scsi_dh: add 'rescan' callback

If a device needs to be rescanned the device_handler might need
to be rechecked, too.
So add a 'rescan' callback to the device handler and call it
upon scsi_rescan_device(). The rescan callback will be invoked
from the Unit Attention handling of ASC/ASCQ 3F 03
(INQUIRY DATA HAS CHANGED).

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

scsi_dh_alua: Send TEST UNIT READY to poll for transitioning

Sending a 'REPORT TARGET PORT GROUP' command is a costly operation,
as the array has to gather information about all ports.
So instead of using RTPG to poll for a status update when a port
is in transitioning we should be sending a TEST UNIT READY, and
wait for the sense code to report success.

Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: update all port states

When we read in the target port group state we should be
updating all affected port groups, otherwise we risk
running out of sync.

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

scsi_dh_alua: Recheck state on unit attention

When we receive a unit attention code of 'ALUA state changed'
we should recheck the state, as it might be due to an implicit
ALUA state transition. This allows us to return NEEDS_RETRY
instead of ADD_TO_MLQUEUE, allowing to terminate the retries
after a certain time.
At the same time a workqueue item might already be queued, which
should be started immediately to avoid any delays.

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

scsi_dh_alua: Add new blacklist flag 'BLIST_SYNC_ALUA'

Add a new blacklist flag BLIST_SYNC_ALUA to instruct the
alua device handler to use synchronous command submission
for ALUA commands.

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

scsi_dh_alua: Allow workqueue to run synchronously

Some arrays may only capable of handling one STPG at a time,
so this patch adds a singlethreaded workqueue for STPGs to be
submitted synchronously.

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

scsi_dh_alua: Use workqueue for RTPG

The current ALUA device_handler has two drawbacks:
- We're sending a 'SET TARGET PORT GROUP' command to every LUN,
disregarding the fact that several LUNs might be in a port group
and will be automatically switched whenever _any_ LUN within
that port group receives the command.
- Whenever a LUN is in 'transitioning' mode we cannot block I/O
to that LUN, instead the controller has to abort the command.
This leads to increased traffic across the wire and heavy load
on the controller during switchover.

With this patch the RTPG handling is moved to a per-portgroup
workqueue. This reduces the number of 'REPORT TARGET PORT GROUP'
and 'SET TARGET PORT GROUPS' sent to the controller as we're sending
them now per port group, and not per device as previously.
It also allows us to block I/O to any LUN / port group found to be
in 'transitioning' ALUA mode, as the workqueue item will be requeued
until the controller moves out of transitioning.

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

scsi_dh_alua: remove 'rel_port' from alua_dh_data structure

The 'relative port' field is not used, and might get stale when
the port group changes. So remove the field altogether.

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

scsi_dh_alua: move optimize_stpg evaluation

When the optimize_stpg module option is set we should just set it
once during port_group allocation. Doing so allows us to override
it later with device specific settings.

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

revert commit a8e5a2d593cb ("[SCSI] scsi_dh_alua: ALUA handler attach should succeed while TPG is transitioning")

This reverts commit a8e5a2d593cbfccf530c3382c2c328d2edaa7b66

Obsoleted by the next patch.

Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: simplify alua_initialize()

Rework alua_check_vpd() to use scsi_vpd_get_tpg()
and move the port group selection into the function, too.
With that we can simplify alua_initialize() to just
call alua_check_tpgs() and alua_check_vpd();

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

scsi_dh_alua: use unique device id

Use scsi_vpd_lun_id() to assign a unique device identification
to the alua port group structure.

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

scsi_dh_alua: Use separate alua_port_group structure

The port group needs to be a separate structure as several
LUNs might belong to the same group.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: allocate RTPG buffer separately

The RTPG buffer will only evaluated within alua_rtpg(),
so we can allocate it locally there and avoid having to
put it into the global structure.

Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: switch to scsi_execute_req_flags()

All commands are issued synchronously, so no need to open-code
scsi_execute_req_flags() anymore. And we can get rid of the
static sense code structure element. scsi_execute_req_flags()
will be setting REQ_QUIET and REQ_PREEMPT, but that is
perfectly fine as we're evaluating and logging any errors
ourselves and we really need to send the command even if
the device is quiesced.

Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: call alua_rtpg() if stpg fails

If the call to SET TARGET PORT GROUPS fails we have no idea what
state the array is left in, so we need to issue a call to
REPORT TARGET PORT GROUPS in these cases.

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

scsi_dh_alua: Make stpg synchronous

The 'activate_complete' function needs to be executed after
stpg has finished, so we can as well execute stpg synchronously
and call the function directly.

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

scsi_dh_alua: separate out alua_stpg()

Separate out SET TARGET PORT GROUP functionality into a separate
function alua_stpg().

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

scsi_dh_alua: Pass buffer as function argument

Pass in the buffer as a function argument for submit_rtpg().

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

scsi_dh_alua: Remove stale variables

With commit 83ea0e5e3501 ("scsi_dh_alua: use scsi_vpd_tpg_id()") these
variables became obsolete, but weren't removed.

[mkp: Fixed checkpatch warning]

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: use scsi_vpd_tpg_id()

Use the common function 'scsi_vpd_tpg_id()' instead of open-coding
it in scsi_dh_alua.

[mkp: Applied by hand]

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: simplify sense code handling

Most sense code is already handled in the generic
code, so we shouldn't be adding special cases here.
However, when doing so we need to check for
unit attention whenever we're sending an internal
command.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: rework alua_check_tpgs() to return the tpgs mode

Instead of returning an error code in alua_check_tpgs() we should
rather return the tpgs mode directly and have a cleaner syntax.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: use unaligned access macros

Use 'get_unaligned_XX' and 'put_unaligned_XX' instead of
open-coding it.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: use flag for RTPG extended header

We should be using a flag when RTPG extended header is not
supported, that saves us sending RTPG twice for older arrays.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: fixup description of stpg_endio()

Fixup copy-and-paste error in the description of stpg_endio().

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: return standard SCSI return codes in submit_rtpg

Fixup submit_rtpg() to always return a standard SCSI return code.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: use standard logging functions

Use standard logging functions instead of hand-crafted ones.

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

scsi_dh_alua: sanitze sense code handling

The only check for a valid sense code is calling scsi_normalize_sense()
and check the return value. So drop the pointless checks and rely on
scsi_normalize_sense() to figure out if the sense code is valid.
With that we can also remove the 'senselen' field.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.com>
Reviewed-by: Bart van Assche <bvanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: improved logging

Issue different logging messages if ALUA is not supported
or the TPGS setting is invalid.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: Use vpd_pg83 information

The SCSI device now has the VPD page 0x83 information attached,
so there is no need to query it again.

[mkp: Fixed a checkpatch warning]

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: Disable ALUA handling for non-disk devices

Non-disk devices might support ALUA, but the firmware
implementation is untested and frequently broken.
As we're don't actually need it disable ALUA support
for non-disk device for now.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh: kill struct scsi_dh_data

Add a ->handler and a ->handler_data field to struct scsi_device and kill
this indirection. Also move struct scsi_device_handler to scsi_dh.h so that
changes to it don't require rebuilding every SCSI LLDD.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi_dh: move device matching to the core code

Add a single list of devices that need non-ALUA device handlers to the core
scsi_dh code so that we can autoload the modules for them at probe time.

While this is a little ugly in terms of architecture it actually
significantly simplifies the code in addition to the new autoloading
functionality.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: handle more device handler setup/teardown in common code

Move all code to set up and tear down sdev->scsi_dh_data to common code.

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

scsi: use container_of to get at device handler private data

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

scsi_dh: get module reference outside of device handler

We need to grab a reference to the module before calling the attach
routines to avoid a small race vs module removal. It also cleans up
the code significantly as a side effect.

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

scsi: TUR path is down after adapter gets reset with multipath

This patch fixes an issue with multipath ipr SAS devices which require a
start unit command to be issued following an adapter reset. Without this
patch, paths get marked failed following an adapter reset and since the
error handler never gets invoked to issue the start unit, the paths are
never recovered. Returning FAILED for this case ensures the error
handler wakes up to issue the start unit.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Tested-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

block,scsi: fixup blk_get_request dead queue scenarios

The blk_get_request function may fail in low-memory conditions or during
device removal (even if __GFP_WAIT is set). To distinguish between these
errors, modify the blk_get_request call stack to return the appropriate
ERR_PTR. Verify that all callers check the return status and consider
IS_ERR instead of a simple NULL pointer check.

For consistency, make a similar change to the blk_mq_alloc_request leg
of blk_get_request. It may fail if the queue is dead, or the caller was
unwilling to wait.

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Jiri Kosina <jkosina@suse.cz> [for pktdvd]
Acked-by: Boaz Harrosh <bharrosh@panasas.com> [for osd]
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

block: add blk_rq_set_block_pc()

With the optimizations around not clearing the full request at alloc
time, we are leaving some of the needed init for REQ_TYPE_BLOCK_PC
up to the user allocating the request.

Add a blk_rq_set_block_pc() that sets the command type to
REQ_TYPE_BLOCK_PC, and properly initializes the members associated
with this type of request. Update callers to use this function instead
of manipulating rq->cmd_type directly.

Includes fixes from Christoph Hellwig <hch@lst.de> for my half-assed
attempt.

Signed-off-by: Jens Axboe <axboe@fb.com>

[SCSI] scsi_dh_alua: ALUA handler attach should succeed while TPG is transitioning

During testing, it was discovered that when a device tries to attach to the
alua handler while in TPG state of transitioning, the alua_rtpg function will
wait for it to exit the state before allowing it to continue. As a result, if
the 60 second timeout expires, the alua handler will not attach to the device.

To fix this, I have introduced an input argument to alua_rtpg called
wait_for_transition. The idea is that it will wait for the transition to
complete before an activation (because the current TPG state has some bearing
in that case), but during a discovery if it is transitioning, it will not
wait, and will store the state as standby for the time being.

I believe the precedent exists for this from commit
c0d289b3e59577532c45ee9110ef81bd7b341272 Since if the device reports a state
of transitioning, it can transition to other more valid states, and it has
been established TPGS is supported on the device, if it is attaching.

Signed-off-by: Sean Stewart <Sean.Stewart@netapp.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: ALUA check sense should retry device internal reset unit attention

When the scsi_dh_alua handler issues an RTPG during initialization, if it gets
0x06/0x29/0x04 as the sense, it will fail to attach the handler. NetApp
E-Series returns 0x29/0x00 for power on, and 0x29/0x04 for conditions that
cause the controller to reboot again. These conditions should be treated
identically within the handler.

Signed-off-by: Sean Stewart <Sean.Stewart@netapp.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Add module parameter to allow failover to non preferred path without STPG

Resending with requested rewording of the parameter description. Currently
ALUA device handler sends STPG command during failover and failback. Failover
can be optimized by implicit failover (by not to sending STPG command), when 1
is passed as hwhandler parameter in multipath.conf. ex "2 alua 1". We may need
to pass the parameter through module param for alua device handler to optimize
failover if incase retain_attached_hwhandler set in multipath.conf and
hwhandler is set with non-tpgs device handler ex: '1 rdac'.

[jejb: fix up whitespace and other issues]
Signed-off-by: Vijay Chauhan <vijay.chauhan@netapp.com>
Signed-off-by: Sean Stewart <Sean.Stewart@netapp.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: fix stpg sense handling

For the stpg_endio path we are not evaluating the sense. The bug
is that

1. The error value is set to -EIO when there is sense, so we hit the first
error check and always return SCSI_DH_IO.

2. h->senselen is set to zero in submit_stpg. It is not later set to
req->sense_len like in the synchrounous exection paths, so we must
check the req->sense_len field.

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

[SCSI] scsi_dh_alua: Enable STPG for unavailable ports

A quote from SPC-4: "While in the unavailable primary target port
asymmetric access state, the device server shall support those of
the following commands that it supports while in the active/optimized
state: [ ... ] d) SET TARGET PORT GROUPS; [ ... ]". Hence enable
sending STPG to a target port group that is in the unavailable state.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Re-enable STPG for unavailable ports

A quote from SPC-4: "While in the unavailable primary target port
asymmetric access state, the device server shall support those of
the following commands that it supports while in the active/optimized
state: [ ... ] d) SET TARGET PORT GROUPS; [ ... ]". Hence re-enable
sending STPG to a target port group that is in the unavailable state.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: backoff alua rtpg retry linearly vs. geometrically

Currently the backoff algorithm for when to retry alua rtpg
requests progresses geometrically as so:

2, 4, 8, 16, 32, 64... seconds.

This progression can lead to un-needed delay in retrying
alua rtpg requests when the rtpgs are delayed. A less
aggressive backoff algorithm that is additive would not
lead to such large jumps when delays start getting long, but
would backoff linearly:

2, 4, 6, 8, 10... seconds.

Signed-off-by: Martin George <marting@netapp.com>
Signed-off-by: Rob Evers <revers@redhat.com>
Reviewed-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: retry alua rtpg extended header for illegal request response

Some storage arrays are known to return 'illegal request'
when an rtpg extended header request is made. T10 says the
array should ignore the bit, and return the non-extended
rtpg as the array doesn't support the request. Working
around this by retrying the rtpg request without the extended
header bit set when the extended rtpg request results in
illegal request.

Signed-off-by: Rob Evers <revers@redhat.com>
Reviewed-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: implement 'implied transition timeout'

During alua transitions, an array can return transitioning
status in response to rtpg requests. These requests get
retried for a maximum of 60 seconds by default before timing
out. Sometimes this timeout isn't sufficient to allow the
array to complete the transition. T10-spc4 addresses this
under 'Report Target Port Groups' command.

This update retrieves the timeout value from the storage
array if available and retries the transitioning rtpgs
for up to the 'implied transitioning timeout' value

Signed-off-by: Rob Evers <revers@redhat.com>
Reviewed-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Optimize the STPG command

This patch optimizes the set target port group(STPG) command. During our
testing, we found that it is not optimal to send stpg command every time
the path group switch happens. This patch uses PREF (preferred target port)
bit with combination of flags passed by multipath user level tool to
optimize this behaviour. If PREF bit is set then it issues a STPG command,
otherwise it will let implicit transfer take place.

By default there is no change in the behaviour. User tool needs to pass the
parameter to make this change take effect. Patch has been tested on NetApp
E series storage.

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Store the PREF bit from RTPG

PREF bit indicates preferred target port group for accessing a logical
unit. This bit is used to optimize the STPG command handling.

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Inroduce the set_params interface scsi_dh_alua handler

Handler expects only one parameter to set the flag ALUA_OPTIMIZE_STPG.
This flag is used to optimize the STPG behaviour. There is no change in
behaviour by default.

For example, to set the flag pass the following parameters from multipath.conf
hardware_handler "2 alua 1"

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Retry the check-condition in case Mode Parameters Changed

This patch adds a check-condition in scsi_dh_alua handler for a retry.
Sometimes, I have seen attach failing due to this check-condition with
following error messages on NetApp E series storage.

Dec 7 15:31:01 nilgiris kernel: [102979.696673] scsi 3:0:2:9: alua: port group 00 rel port 01
Dec 7 15:31:01 nilgiris kernel: [102979.697082] scsi 3:0:2:9: alua: rtpg failed with 8000002
Dec 7 15:31:01 nilgiris kernel: [102979.697086] scsi 3:0:2:9: alua: rtpg sense code 06/2a/01
Dec 7 15:31:01 nilgiris kernel: [102979.697088] scsi 3:0:2:9: alua: not attached

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Fix the time inteval for alua rtpg commands

This patch corrects the retry interval for alua rtpg command. Purpose was to retry the commands in seconds.
But that was not happening. Reason is msleep takes argument in milliseconds.

Also added minor text after successful attach.

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

scsi: Fix up files implicitly depending on module.h inclusion

The module.h header was implicitly present everywhere, so files
with no explicit include of the module infrastructure would build
anyway. We are now removing the implicit include, and so we need
to call out the module.h file that we need explicitly.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

[SCSI] scsi_dh_alua: Add one more check-condition for alua handler

This patch adds one more check-condition for scsi_dh_alua handler. Without
this, the handler attach fails sometimes during the discovery. I have noticed
this with NetApp E-Series storage with alua mode. Also removed some
unnecessary brackets {} for consistency.

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Decrease retry interval

The alua device handler starts the first retry after 10 seconds,
and increases it times 10 for each round.
This leads to an unnecessary delay. This patch modifies it to
start after one second, and increase by a factor of two.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Fix Erroneous TPG ID check

For Target Portal Group IDs occupying the full 2 bytes in the
RTPG response, the following group_id check in the alua_rtpg
routine always fails in scsi_dh_alua.c:

if (h->group_id == (ucp[2] << 8) + ucp[3]) {

This causes the ALUA handler to wrongly identify the AAS of
a specified device as well as incorrectly interpreting the
supported AAS of the target as seen by the following entries
in the /var/log/messages:

"alua: port group 3ea state A supports tousna"
"alua: port group 3e9 state A supports tousna"

This is because 'ucp' is wrongly declared in alua_rtpg as
a character pointer instead of an unsigned character pointer.

Signed-off-by: Martin George <marting@netapp.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: always update TPGS status on activate

When activating a patch we should always update the TPGS state
as it might have changed in between.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh: Implement match callback function

Some device handler types are not tied to the vendor/model
but rather to a specific capability. Eg ALUA is supported
if the 'TPGS' setting in the standard inquiry is set.
This patch implements a 'match' callback for device handler
which supersedes the original vendor/model lookup and
implements the callback for the ALUA handler.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Evaluate TPGS setting from inquiry data

Instead of issuing a standard inquiry from within the
alua device handler we can evaluate the TPGS setting from
the existing inquiry data of the sdev and save us the I/O.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Attach to UNAVAILABLE/OFFLINE AAS devices

The SCSI ALUA handler currently fails to attach to devices
reporting an UNAVAILABLE/OFFLINE AAS. But given that an
UNAVAILABLE/OFFLINE AAS can transition to other states
like ACTIVE/OPTIMIZED, ACTIVE/NON-OPTIMIZED, etc. as per
SPC4, this ALUA handler behavior should be rectified so
as to attach to devices which also report an
UNAVAILABLE/OFFLINE AAS.

Signed-off-by: Martin George <marting@netapp.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

[SCSI] scsi_dh: cosmetic change to sizeof()

instead of doing sizeof(struct X) it's better to do sizeof(*v) where v
is the variable pointing to struct X.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Babu Moger <babu.moger@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_alua: add scalable ONTAP lun to dev list

Currently NetApp's VID/PID details in the INQUIRY response shows up as
'NETAPP' and 'LUN'. With upcoming scalable SAN ONTAP version on NetApp
controllers, the PID entry alone is being modified to 'LUN C-Mode' (to
distinguish current ONTAP LUNs from scalable ONTAP LUNs).

'LUN' would still suffice for matching 'LUN C-Mode' but best to
explicitly add these new NetApp LUNs to the device list.

Reported-by: Martin George <marting@netapp.com>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_alua: Add Promise VTrak to dev list

Adds Promise VTrak devices to the ALUA device handler.

Signed-off-by: Ilgu Hong <ilgu.hong@promise.com>
Signed-off-by: Joseph Gruher <joseph.r.gruher@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_alua: fix stpg_endio group state reporting

Initialize stpg_endio() 'err' to SCSI_DH_OK and only change it to
SCSI_DH_IO accordingly. This allows the switching of target group state
to be properly reported when no error has occurred.

Signed-off-by: Joseph Gruher <joseph.r.gruher@intel.com>
Signed-off-by: Ilgu Hong <ilgu.hong@promise.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_alua: fix deadlock in stpg_endio

The use of blk_execute_rq_nowait() implies __blk_put_request() is needed
in stpg_endio() rather than blk_put_request() -- blk_finish_request() is
called with queue lock already held.

Signed-off-by: Joseph Gruher <joseph.r.gruher@intel.com>
Signed-off-by: Ilgu Hong <ilgu.hong@promise.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_alua: fix submit_stpg return

submit_stpg() will always return failure so alua_activate() will report
failure via dm-multipath callback function. Even though the stpg fired
successfuly dm-multipath does not know and always fails to change the
valid path.

By returning SCSI_DH_OK we're now skipping alua_activate()'s call to
activate_complete 'fn'. But this is fine because stpg_endio() will call
it via h->callback_fn().

Signed-off-by: Joseph Gruher <joseph.r.gruher@intel.com>
Signed-off-by: Ilgu Hong <ilgu.hong@promise.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_alua: Handle all states correctly

For ALUA we should be handling all states, independent of whether
the mode is explicit or implicit. For 'Transitioning' we should retry
for a certain amount of time; after that we're setting the port
to 'Standby' and return SCSI_DH_RETRY to signal upper layers
a retry is in order here.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

[SCSI] scsi_dh_alua: Add IBM Power Virtual SCSI ALUA device to dev list

Adds IBM Power Virtual SCSI ALUA devices to the ALUA device handler.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_alua: add netapp to dev list

Newer Netapp target software supports ALUA, so
this patch adds them to the scsi_dev_alua dev list.

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

[SCSI] scsi_dh: Make alua hardware handler's activate() async

Make the activate function asynchronous by using blk_execute_rq_nowait()

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh: Change the scsidh_activate interface to be asynchronous

Make scsi_dh_activate() function asynchronous, by taking in two additional
parameters, one is the callback function and the other is the data to call
the callback function with.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ALUA: send STPG if explicit and implicit is supported

alua_activate only sends a STPG if only explicit is suppored.
As a result, for EMC targets that support both we end up doing
a implicit failover when X commands are finally sent to
the other SP.

This patch does a AND on the h->tpgs, so we do a explicit failover
right away.

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

[SCSI] scsi dh alua: handle report luns data changed in check sense callout

When we switch controllers the Intel Multi-Flex reports
REPORTED_LUNS_DATA_HAS_CHANGED. This patch just has us
retry the command.

Signed-off-by: Ilgu Hong <ilgu.hong@promise.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi dh alua: add intel Multi-Flex device

This adds the Intel Multi-Flex device to scsi_dh_alua's
scsi_dh_devlist, so the module attaches to these devs.

Signed-off-by: Ilgu Hong <ilgu.hong@promise.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi dh alua: fix group id masking

The buf[i] is a byte but we are only asking 4 bits off the
group_id. This patch has us take off a byte.

Signed-off-by: Ilgu Hong <ilgu.hong@promise.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh_alua: remove REQ_NOMERGE

We do not need to set REQ_NOMERGE because when the module calls
blk_execute_rq -> blk_execute_rq_nowait, blk_execute_rq_nowait sets
it for us. This brings all the modules in sync for those bits.

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

[SCSI] block: separate failfast into multiple bits.

Multipath is best at handling transport errors. If it gets a device
error then there is not much the multipath layer can do. It will just
access the same device but from a different path.

This patch breaks up failfast into device, transport and driver errors.
The multipath layers (md and dm mutlipath) only ask the lower levels to
fast fail transport errors. The user of failfast, read ahead, will ask
to fast fail on all errors.

Note that blk_noretry_request will return true if any failfast bit
is set. This allows drivers that do not support the multipath failfast
bits to continue to fail on any failfast error like before. Drivers
like scsi that are able to fail fast specific errors can check
for the specific fail fast type. In the next patch I will convert
scsi.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: make check_sense return ADD_TO_MLQUEUE

Change scsi_dh check_sense functions to return ADD_TO_MLQUEUE
to allow retries to occur without restriction of blk_noretry_request
check.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

make struct scsi_dh_devlist's static

This patch makes several needlessly global struct scsi_dh_devlist's
static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] replace __FUNCTION__ with __func__

[jejb: fixed up a ton of missed conversions.

All of you are on notice this has happened, driver trees will now
need to be rebased]

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: SCSI List <linux-scsi@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: add generic SPC-3 alua handler

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>