bsg_softirq_done() and fc_bsg_softirq_done() are copies of each other, so
ditch the fc specific one.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

fc_destroy_bsgjob() and bsg_destroy_job() are now 1:1 copies, so use the
latter. As bsg_destroy_job() comes from bsg-lib we need to select it in
Kconfig once CONFOG_SCSI_FC_ATTRS is active.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Change FC drivers to use 'struct bsg_job' from bsg-lib.h instead of
'struct fc_bsg_job' from scsi_transport_fc.h and remove 'struct
fc_bsg_job'.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Implement kref backed reference counting instead of rolling our own. This
elimnates the need of the following fields in 'struct fc_bsg_job':
* ref_cnt
* state_flags
* job_lock
bringing us close to unification of 'struct fc_bsg_job' and 'struct bsg_job'.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Provide fc_bsg_to_rport() helper that will become handy when we're
moving from struct fc_bsg_job to a plain struct bsg_job. Also move all
LLDDs to use the new helper.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Provide fc_bsg_to_shost() helper that will become handy when we're
moving from struct fc_bsg_job to a plain struct bsg_job. Also use this
little helper in the LLDDs.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Export fc_bsg_jobdone so drivers can use it directly instead of doing
the round-trip via struct fc_bsg_job::job_done() and use it in the
LLDDs.  That way we can also unify the interfaces of fc_bsg_jobdone and
bsg_job_done.

As we've converted all LLDDs over to use fc_bsg_jobdone() directly, we
can remove the function pointer from struct fc_bsg_job as well.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Don't use fc_bsg_job::request and fc_bsg_job::reply directly, but use
helper variables bsg_request and bsg_reply. This will be helpful when
transitioning to bsg-lib.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

struct fc_bsg_buffer is just a clone of struct bsg_buffer from bsg-lib,
so use this one instead.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

It is required to hold the queue lock when calling blk_run_queue_async()
to avoid that a race between blk_run_queue_async() and
blk_cleanup_queue() is triggered. Additionally, remove the get_device()
and put_device() calls from fc_bsg_goose_queue. It is namely the
responsibility of the caller of fc_bsg_goose_queue() to ensure that the
bsg queue does not disappear while fc_bsg_goose_queue() is in progress.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: James Smart <james.smart@avagotech.com>
Reviewed-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Required for the next patch.
Signed-off-by: NHannes Reinecke <hare@suse.com>
Acked-by: NJohannes Thumshirn <jth@kernel.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Running the command "git grep -nHw scsi_is_fc_vport" shows that this
function is only called from inside scsi_transport_fc.c. Hence unexport
this function.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: James Smart <james.smart@avagotech.com>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

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: NHannes Reinecke <hare@suse.de>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Tested-by: NLaurence Oberman <loberman@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Use scsi_host_{get,put}() instead of open-coding these functions.
Compile-tested only.

[mkp: Dropped CC:stable and fixed James Smart's email address]
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: James Smart <james.smart@avagotech.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: NJames Smart <james.smart@emulex.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

These speeds are to support the next generation of FCoE port speeds.
Signed-off-by: NDick Kennedy <Dick.Kennedy@Emulex.Com>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Now that the ibmvstgt driver as the only user of scsi_tgt is gone, the
scsi_tgt kernel module, the CONFIG_SCSI_TGT, CONFIG_SCSI_SRP_TGT_ATTRS and
CONFIG_SCSI_FC_TGT_ATTRS kbuild variable, the scsi_host_template
transfer_response method are no longer needed.

[hch: minor updates to the current tree, changelog update]
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>

The SCSI standard defines 64-bit values for LUNs, and large arrays
employing large or hierarchical LUN numbers become more and more
common.

So update the linux SCSI stack to use 64-bit LUN numbers.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChristoph Hellwig <hch@infradead.org>
Reviewed-by: NEwan Milne <emilne@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

debugfs caught this:
WARNING: at lib/debugobjects.c:260 debug_print_object+0x83/0xa0()
ODEBUG: free active (active state 0) object type: work_struct
hint: fc_scsi_scan_rport+0x0/0xd0 [scsi_transport_fc]
 CPU: 1 PID: 184 Comm: kworker/1:1 Tainted: G        W
--------------   3.10.0-123.el7.x86_64.debug #1
Hardware name: HP ProLiant DL120 G7, BIOS J01 07/01/2013
Workqueue: fc_wq_5 fc_rport_final_delete [scsi_transport_fc]
Call Trace:
[<ffffffff8169efec>] dump_stack+0x19/0x1b
[<ffffffff8106cbd1>] warn_slowpath_common+0x61/0x80
[<ffffffff8106cc4c>] warn_slowpath_fmt+0x5c/0x80
[<ffffffff8133e003>] debug_print_object+0x83/0xa0
[<ffffffffa04e2f40>] ? fc_parse_wwn+0x100/0x100

[<ffffffff8133f23b>] debug_check_no_obj_freed+0x22b/0x270
[<ffffffffa04e127e>] ? fc_rport_dev_release+0x1e/0x30
[<ffffffff811db3e9>] kfree+0xd9/0x2d0
[<ffffffffa04e127e>] fc_rport_dev_release+0x1e/0x30
[<ffffffff81428032>] device_release+0x32/0xa0
[<ffffffff8132701e>] kobject_release+0x7e/0x1b0
[<ffffffff81326ed8>] kobject_put+0x28/0x60
[<ffffffff81428397>] put_device+0x17/0x20
[<ffffffffa04e5025>] fc_rport_final_delete+0x165/0x210
[<ffffffff810959b0>] process_one_work+0x220/0x710
[<ffffffff81095944>] ? process_one_work+0x1b4/0x710
[<ffffffff81095fbb>] worker_thread+0x11b/0x3a0
[<ffffffff81095ea0>] ? process_one_work+0x710/0x710
[<ffffffff8109e0cd>] kthread+0xed/0x100
[<ffffffff8109dfe0>] ? insert_kthread_work+0x80/0x80
[<ffffffff816b2fec>] ret_from_fork+0x7c/0xb0
[<ffffffff8109dfe0>] ? insert_kthread_work+0x80/0x80

Seems to be because the scan_work work_struct might be active when the housing
fc_rport struct gets freed.  Ensure that we cancel it prior to freeing the rport
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Reviewed-by: NVasu Dev <vasu.dev@intel.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NChad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: NSaurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

For the workqueue creation interfaces that do not expect format strings,
make sure they cannot accidently be parsed that way.  Additionally, clean
up calls made with a single parameter that would be handled as a format
string.  Many callers are passing potentially dynamic string content, so
use "%s" in those cases to avoid any potential accidents.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NHong Zhiguo <honkiko@gmail.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This has scsi_internal_device_unblock/scsi_target_unblock take
the new state to set the devices as an argument instead of
always setting to running. The patch also converts users of these
functions.

This allows the FC and iSCSI class to transition devices from blocked
to transport-offline, so that when fast_io_fail/replacement_timeout
has fired we do not set the devices back to running. Instead, we
set them to SDEV_TRANSPORT_OFFLINE.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The libfc provides more flexibility and with that
we can monitor some more FC specific stats for
FC exches or FCP error cases, this patch add
such new FC stats.

The patch adds *only* FC specific new stats to
existing fc_host attribute container.

Added stats names are self explanatory as
existing FC stats already has, however anyway
still added commentary along their definition
to describe them.
Signed-off-by: NVasu Dev <vasu.dev@intel.com>
Acked-by : Robert Love <robert.w.love@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

iscsi_remove_host() uses bsg_remove_queue() which implements custom
queue draining.  fc_bsg_remove() open-codes mostly identical logic.

The draining logic isn't correct in that blk_stop_queue() doesn't
prevent new requests from being queued - it just stops processing, so
nothing prevents new requests to be queued after the logic determines
that the queue is drained.

blk_cleanup_queue() now implements proper queue draining and these
custom draining logics aren't necessary.  Drop them and use
bsg_unregister_queue() + blk_cleanup_queue() instead.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: James Smart <james.smart@emulex.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

When a rport is added back or the role is changed the fc class
will queue a scan and then call scsi_target_unblock. The problem
with this is if the devices are in the SDEV_OFFLINE state and
the scan is run before the scsi_target_unblock, then the scan
will see LUN0 as offline and the scan will fail. This patch moves
the unblock call to before the scan, so we know the device state
will be set correctly when the scan is run.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This adds FC-GS Fabric Device Management Interface
(FDMI) related attributes to fc_host_attr structure.

This is in preparation for allowing FDMI attributes
to be registered via libfc.
Signed-off-by: NNeerav Parikh <neerav.parikh@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Acked-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This patch fixes a bug where devloss is not called on fc_host teardown.
The issue is seen if the LLDD uses rport_rolechg to add the target role
to an rport.

When an rport goes away, the LLDD will call fc_remote_port_delete, which
will start the devloss timer.  If the timer expires, the transport will
call the devloss callback and set the FC_RPORT_DEVLOSS_CALLBK_DONE flag.
However, the rport structure is not deleted, it is retained to store the
SCSI id mappings for the rport in case it comes back. In the scenario
where it does come back, and the driver calls fc_remote_port_add, but does
not indicate the "target" role for the rport - the create will clear the
structure, but forgets to clear FC_RPORT_DEVLOSS_CALLBK_DONE flag (which
is cleared if it's added with the target role). The secondary call, of
fc_remote_port_rolechg to add the target role also does not clear the flag.
Thus, the next time the rport goes away, the resulting devloss timer
expiration will not call the driver callback as the flag is still set.

This patch adds the FC_RPORT_DEVLOSS_CALLBK_DONE flags to the list of
those that are cleared upon reuse of the rport structure.
Signed-off-by: NAlex Iannicelli <alex.iannicelli@emulex.com>
Signed-off-by: NJames Smart <james.smart@emulex.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Creating and destroying fcoe interface in a tight loop leads to a system
deadlock with the following call traces:

Call Trace:
[<ffffffff814f4b3d>] schedule_timeout+0x1fd/0x2c0
[<ffffffff814f469f>] ? wait_for_common+0x4f/0x190
[<ffffffff814f469f>] ? wait_for_common+0x4f/0x190
[<ffffffff814f4737>] wait_for_common+0xe7/0x190
[<ffffffff81042fa0>] ? default_wake_function+0x0/0x20
[<ffffffff81082c2d>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff814f48bd>] wait_for_completion+0x1d/0x20
[<ffffffff81066d90>] flush_workqueue+0x290/0x5f0
[<ffffffff81066b00>] ? flush_workqueue+0x0/0x5f0
[<ffffffff81067148>] destroy_workqueue+0x38/0x340
[<ffffffffa0260289>] fc_remove_host+0x1b9/0x1f0 [scsi_transport_fc]
[<ffffffffa02ed195>] bnx2fc_if_destroy+0xc5/0x1f0 [bnx2fc]
[<ffffffffa02ed33a>] bnx2fc_destroy+0x7a/0x100 [bnx2fc]
[<ffffffffa02c789b>] fcoe_transport_destroy+0x9b/0x1b0 [libfcoe]
[<ffffffff81069ec2>] param_attr_store+0x52/0x80
[<ffffffff81069976>] module_attr_store+0x26/0x30
[<ffffffff8119e726>] sysfs_write_file+0xe6/0x170
[<ffffffff81134710>] vfs_write+0xd0/0x1a0
[<ffffffff811348e4>] sys_write+0x54/0xa0
[<ffffffff81002e02>] system_call_fastpath+0x16/0x1b
Call Trace:
[<ffffffff81074865>] async_synchronize_cookie_domain+0x75/0x120
[<ffffffff8106caa0>] ? autoremove_wake_function+0x0/0x40
[<ffffffff81074925>] async_synchronize_cookie+0x15/0x20
[<ffffffff8107494c>] async_synchronize_full+0x1c/0x40
[<ffffffffa0057466>] sd_remove+0x36/0xc0 [sd_mod]
[<ffffffff81358a75>] __device_release_driver+0x75/0xe0
[<ffffffff81358bef>] device_release_driver+0x2f/0x50
[<ffffffff81357aee>] bus_remove_device+0xbe/0x120
[<ffffffff813553ef>] device_del+0x12f/0x1e0
[<ffffffff8137454d>] __scsi_remove_device+0xbd/0xc0
[<ffffffff81374585>] scsi_remove_device+0x35/0x50
[<ffffffff813746a7>] __scsi_remove_target+0xe7/0x110
[<ffffffff81374730>] ? __remove_child+0x0/0x30
[<ffffffff81374753>] __remove_child+0x23/0x30
[<ffffffff81354a2c>] device_for_each_child+0x4c/0x80
[<ffffffff81374703>] scsi_remove_target+0x33/0x60
[<ffffffffa02622c6>] fc_starget_delete+0x26/0x30 [scsi_transport_fc]
[<ffffffffa026271a>] fc_rport_final_delete+0xaa/0x200 [scsi_transport_fc]
[<ffffffff8106585a>] process_one_work+0x1aa/0x540
[<ffffffff810657eb>] ? process_one_work+0x13b/0x540
[<ffffffffa0262670>] ? fc_rport_final_delete+0x0/0x200 [scsi_transport_fc]
[<ffffffff81067ac9>] worker_thread+0x179/0x410
[<ffffffff81067950>] ? worker_thread+0x0/0x410
[<ffffffff8106c546>] kthread+0xb6/0xc0
[<ffffffff8103879b>] ? finish_task_switch+0x4b/0xe0
[<ffffffff81003ca4>] kernel_thread_helper+0x4/0x10
[<ffffffff814f7994>] ? restore_args+0x0/0x30
[<ffffffff8106c490>] ? kthread+0x0/0xc0
[<ffffffff81003ca0>] ? kernel_thread_helper+0x0/0x10

fc_remove_host() waits for flushing the workqueue, but it is stuck at flushing
the first work. The first work doesnt complete, because it is waiting for async
layer to complete the IOs. The async layer cannot complete the IO as the
terminate_rport_io for the second work was not called, which will be called
only when the first work completes. Hence the deadlock.  To resolve this
deadlock, the workqueue allocation has been modified from
create_singlethread_workqueue() to alloc_workqueue().

In addition, fc_terminate_rport_io() should be called before the
scsi_flush_work() to avoid the similar deadlock as above.

scsi fc alloc queue. move terminate rport io before flush
Signed-off-by: NNithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

We are currently using this flag to check whether it's safe
to call into ->request_fn(). If it is set, we punt to kblockd.
But we get a lot of false positives and excessive punts to
kblockd, which hurts performance.

The only real abuser of this infrastructure is SCSI. So export
the async queue run and convert SCSI over to use that. There's
room for improvement in that SCSI need not always use the async
call, but this fixes our performance issue and they can fix that
up in due time.
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Instead of overloading __blk_run_queue to force an offload to kblockd
add a new blk_run_queue_async helper to do it explicitly.  I've kept
the blk_queue_stopped check for now, but I suspect it's not needed
as the check we do when the workqueue items runs should be enough.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

__blk_run_queue() automatically either calls q->request_fn() directly
or schedules kblockd depending on whether the function is recursed.
blk-flush implementation needs to be able to explicitly choose
kblockd.  Add @force_kblockd.

All the current users are converted to specify %false for the
parameter and this patch doesn't introduce any behavior change.

stable: This is prerequisite for fixing ide oops caused by the new
        blk-flush implementation.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: stable@kernel.org
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

This adds a fc host dev loss sysfs file. Instead of
calling into the driver using the get_host_def_dev_loss_tmo
callback, we allow drivers to init the dev loss like is done
for other fc host params, and then the fc class will handle
updating the value if the user writes to the new sysfs file.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

When an rport is "blocked" and a bsg request is received, the bsg request gets
placed on the queue but the queue stalls. If the fc object is then deleted - the
bsg queue never restarts and keeps the reference on the object, and stops the
overall teardown.

This patch restarts the bsg queue on teardown and drains any pending requests,
allowing the teardown to succeed.
Signed-off-by: NCarl Lajeunesse <carl.lajeunesse@emulex.com>
Signed-off-by: NJames Smart <james.smart@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

This patch adds a fc_host setting to store the
default dev_loss_tmo. It is used if the driver
has a callack to get the value from the LLD. If
the callback is not set, then we use the fc class
module default value.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Signed-off-by: NAndy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Adaptec OEM Raid Solutions <aacraid@adaptec.com>
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Cc: James Smart <james.smart@emulex.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

If the scsi eh is running and then a FC LLD calls
fc_remote_port_delete, the SCSI commands sent from the eh will fail.
To prevent this, a FC LLD can call fc_block_scsi_eh from the eh
callback, blocking the eh thread until the dev_loss_tmo fires or the
remote port is available again.

If (e.g. for a multipathing setup) the dev_loss_tmo is set to a very
large value, thus preventing the scsi device removal , the scsi eh can
block for a long time. For multipathing, the fast_io_fail_tmo is then
set to a low value to detect path problems sooner.

This patch introduces a new return code FAST_IO_FAIL. The function
fc_block_scsi_eh now returns FAST_IO_FAIL when the fast_io_fail_tmo
fires. This indicates that the LLD terminated all pending I/O requests
and there are no more pending SCSI commands for the scsi eh to wait
for. This return code can be passed back to the scsi eh to stop the
escalation and finish the recovery process for this device.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>