scsi: core: Remove <scsi/scsi_request.h>

This header is empty now except for an include of <linux/blk-mq.h>, so
remove it.

Link: https://lore.kernel.org/r/20220224175552.988286-9-hch@lst.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: bsg: Simplify device registration

Use the per-device cdev_device_interface to store the bsg data in the char
device inode, and thus remove the need to embedd the bsg_class_device
structure in the request_queue.

Link: https://lore.kernel.org/r/20210729064845.1044147-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: switch all files cleared marked as GPLv2 or later to SPDX tags

All these files have some form of the usual GPLv2 or later boilerplate.
Switch them to use SPDX tags instead.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: bsg-lib: handle bidi requests without block layer help

We can just stash away the second request in struct bsg_job instead of
using the block layer req->next_rq field, allowing for the eventual removal
of the latter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

bsg: move bsg-lib parts outside of request queue

Get rid of the special bsg job fn and timeout handler, move them
into a private bsg_set instead.

Mostly from Christoph, with fixes for error handling and cleanups.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

bsg: provide bsg_remove_queue() helper

All drivers do unregister + cleanup, provide a helper for that.

Cc: linux-scsi@vger.kernel.org
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

bsg: pass in desired timeout handler

This will ease in the conversion to blk-mq, where we can't set
a timeout handler after queue init.

Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: linux-scsi@vger.kernel.org
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove parent device reference from struct bsg_class_device

Bsg holding a reference to the parent device may result in a crash if a
bsg file handle is closed after the parent device driver has unloaded.

Holding a reference is not really needed: the parent device must exist
between bsg_register_queue and bsg_unregister_queue. Before the device
goes away the caller does blk_cleanup_queue so that all in-flight
requests to the device are gone and all new requests cannot pass beyond
the queue. The queue itself is a refcounted object and it will stay
alive with a bsg file.

Based on analysis, previous patch and changelog from Anatoliy Glagolev.

Reported-by: Anatoliy Glagolev <glagolig@gmail.com>
Reviewed-by: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

bsg: split handling of SCSI CDBs vs transport requeues

The current BSG design tries to shoe-horn the transport-specific
passthrough commands into the overall framework for SCSI passthrough
requests. This has a couple problems:

- each passthrough queue has to set the QUEUE_FLAG_SCSI_PASSTHROUGH flag
despite not dealing with SCSI commands at all. Because of that these
queues could also incorrectly accept SCSI commands from in-kernel
users or through the legacy SCSI_IOCTL_SEND_COMMAND ioctl.
- the real SCSI bsg queues also incorrectly accept bsg requests of the
BSG_SUB_PROTOCOL_SCSI_TRANSPORT type
- the bsg transport code is almost unredable because it tries to reuse
different SCSI concepts for its own purpose.

This patch instead adds a new bsg_ops structure to handle the two cases
differently, and thus solves all of the above problems. Another side
effect is that the bsg-lib queues also don't need to embedd a
struct scsi_request anymore.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

bsg-lib: remove bsg_job.req

Users of the bsg-lib interface should only use the bsg_job data structure
and not know about implementation details of it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

bsg-lib: introduce a timeout field in struct bsg_job

The zfcp driver wants to know the timeout for a bsg job, so add a field
to struct bsg_job for it in preparation of not exposing the request
to the bsg-lib users.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: bsg-lib: pass the release callback through bsg_setup_queue

The SAS code will need it. Also mark the name argument const to match
bsg_register_queue.

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

bsg-lib: fix kernel panic resulting from missing allocation of reply-buffer

Since we split the scsi_request out of struct request bsg fails to
provide a reply-buffer for the drivers. This was done via the pointer
for sense-data, that is not preallocated anymore.

Failing to allocate/assign it results in illegal dereferences because
LLDs use this pointer unquestioned.

An example panic on s390x, using the zFCP driver, looks like this (I had
debugging on, otherwise NULL-pointer dereferences wouldn't even panic on
s390x):

Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6403
Fault in home space mode while using kernel ASCE.
AS:0000000001590007 R3:0000000000000024
Oops: 0038 ilc:2 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: <Long List>
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.12.0-bsg-regression+ #3
Hardware name: IBM 2964 N96 702 (z/VM 6.4.0)
task: 0000000065cb0100 task.stack: 0000000065cb4000
Krnl PSW : 0704e00180000000 000003ff801e4156 (zfcp_fc_ct_els_job_handler+0x16/0x58 [zfcp])
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000001 000000005fa9d0d0 000000005fa9d078 0000000000e16866
000003ff00000290 6b6b6b6b6b6b6b6b 0000000059f78f00 000000000000000f
00000000593a0958 00000000593a0958 0000000060d88800 000000005ddd4c38
0000000058b50100 07000000659cba08 000003ff801e8556 00000000659cb9a8
Krnl Code: 000003ff801e4146: e31020500004 lg %r1,80(%r2)
000003ff801e414c: 58402040 l %r4,64(%r2)
#000003ff801e4150: e35020200004 lg %r5,32(%r2)
>000003ff801e4156: 50405004 st %r4,4(%r5)
000003ff801e415a: e54c50080000 mvhi 8(%r5),0
000003ff801e4160: e33010280012 lt %r3,40(%r1)
000003ff801e4166: a718fffb lhi %r1,-5
000003ff801e416a: 1803 lr %r0,%r3
Call Trace:
([<000003ff801e8556>] zfcp_fsf_req_complete+0x726/0x768 [zfcp])
[<000003ff801ea82a>] zfcp_fsf_reqid_check+0x102/0x180 [zfcp]
[<000003ff801eb980>] zfcp_qdio_int_resp+0x230/0x278 [zfcp]
[<00000000009b91b6>] qdio_kick_handler+0x2ae/0x2c8
[<00000000009b9e3e>] __tiqdio_inbound_processing+0x406/0xc10
[<00000000001684c2>] tasklet_action+0x15a/0x1d8
[<0000000000bd28ec>] __do_softirq+0x3ec/0x848
[<00000000001675a4>] irq_exit+0x74/0xf8
[<000000000010dd6a>] do_IRQ+0xba/0xf0
[<0000000000bd19e8>] io_int_handler+0x104/0x2d4
[<00000000001033b6>] enabled_wait+0xb6/0x188
([<000000000010339e>] enabled_wait+0x9e/0x188)
[<000000000010396a>] arch_cpu_idle+0x32/0x50
[<0000000000bd0112>] default_idle_call+0x52/0x68
[<00000000001cd0fa>] do_idle+0x102/0x188
[<00000000001cd41e>] cpu_startup_entry+0x3e/0x48
[<0000000000118c64>] smp_start_secondary+0x11c/0x130
[<0000000000bd2016>] restart_int_handler+0x62/0x78
[<0000000000000000>] (null)
INFO: lockdep is turned off.
Last Breaking-Event-Address:
[<000003ff801e41d6>] zfcp_fc_ct_job_handler+0x3e/0x48 [zfcp]

Kernel panic - not syncing: Fatal exception in interrupt

This patch moves bsg-lib to allocate and setup struct bsg_job ahead of
time, including the allocation of a buffer for the reply-data.

This means, struct bsg_job is not allocated separately anymore, but as part
of struct request allocation - similar to struct scsi_cmd. Reflect this in
the function names that used to handle creation/destruction of struct
bsg_job.

Reported-by: Steffen Maier <maier@linux.vnet.ibm.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request")
Cc: <stable@vger.kernel.org> #4.11+
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/bsg: move queue creation into bsg_setup_queue

Simply the boilerplate code needed for bsg nodes a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

scsi: fc: move FC transport's bsg code to bsg-lib

Now that all conversions are done, move the FibreChannel bsg code over
to the bsg library.

This patch is derived from work done by Mike Christie in 2011 [1] but
only the iscsi parts got merged back then.

[1] http://marc.info/?l=linux-scsi&m=131149780921009&w=2

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

block: add bsg_job_put() and bsg_job_get()

Add bsg_job_put() and bsg_job_get() so don't need to export
bsg_destroy_job() any more.

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

scsi: fc: use bsg_softirq_done

bsg_softirq_done() and fc_bsg_softirq_done() are copies of each other, so
ditch the fc specific one.

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

scsi: fc: Use bsg_destroy_job

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

block: add reference counting for struct bsg_job

Add reference counting to 'struct bsg_job' so we can implement a reuqest
timeout handler for bsg_jobs, which is needed for Fibre Channel.

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

bsg: Remove unused function bsg_goose_queue()

The function bsg_goose_queue() does not have any in-tree callers,
so let's remove it.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: drop custom queue draining used by scsi_transport_{iscsi|fc}

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: Tejun Heo <tj@kernel.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: James Smart <james.smart@emulex.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add bsg helper library

This moves the FC classes bsg code to the block layer and
makes it a lib so that other classes like iscsi and SAS can use it.

It is helpful because working with the request queue, bios,
creating scatterlists, etc are a pain that the LLD does not
have to worry about with normal IOs and should not have to
worry about for bsg requests.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>